Vector Corrosion Technologies Limited v E-Chem Technologies Ltd
[2022] FCA 188
•9 March 2022
FEDERAL COURT OF AUSTRALIA
Vector Corrosion Technologies Limited v E-Chem Technologies Ltd [2022] FCA 188
File number(s): QUD 117 of 2019 Judgment of: JAGOT J Date of judgment: 9 March 2022 Catchwords: INTELLECTUAL PROPERTY — contested entitlement to patent concerning electrochemical treatment of corrosion in reinforced concrete — where applicant claims sole or joint ownership of patent as ex-employees conceived of inventive concept while working at business later purchased by applicant — where inventive concept conceived of by respondents after leaving former employer — proceeding dismissed with costs Legislation: Evidence Act 1995 (Cth) s 63
Patents Act 1990 (Cth) ss 15(1), 34(1), 138(3)–(4), 192, sch 1
Patents Act 1977 (UK) ss 7, 39–42
Cases cited: Concrete Preservation Technologies v Vector Corrosion Technologies [2013] APO 71
Duoguard Australia Pty Ltd v Vector Corrosion TechnologiesLtd [2015] APO 86; (2015) 118 IPR 612
JMVB Enterprises Pty Ltd v Camoflag Pty Ltd [2005] FCA 1474; (2005) 67 IPR 68
Kafataris v Davis [2016] FCAFC 134; (2016) 120 IPR 206
Markem Corp v Zipher Ltd [2005] EWCA Civ 267; [2005] RPC 31
Neobev Pty Ltd v Bacchus Distillery Pty Ltd (Administrators Appointed) (No 3) [2014] FCA 4; (2014) 104 IPR 249
Polwood Pty Ltd v Foxworth Pty Ltd [2008] FCAFC 9; (2008) 165 FCR 527
Shum v Intel Corporation 499 F.3d 1272 (2007)
Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth [2010] FCA 1211; (2010) 88 IPR 459
Stack v Davies ShephardPty Ltd [2001] FCA 501; (2001) 108 FCR 422
Stanelco Fibre Optics Ltd’s Application (No 2) [2005] RPC 16University of Western Australia v Gray (No 20) [2008] FCA 498; (2008) 76 IPR 222
University of Western Australia v Gray [2009] FCAFC 116; (2009) 179 FCR 346
Vehicle Monitoring Systems Pty Ltd v SARB Management Group Pty Ltd [2021] FCAFC 224
Yeda Research & Development Co Ltd v Rhone-Poulenc Rorer International Holdings Inc [2007] UKHL 43; [2008] RPC 1
Division: General Division Registry: Queensland National Practice Area: Intellectual Property Sub-area: Patents and associated Statutes Number of paragraphs: 388 Date of last submission/s: 2 July 2021 Date of hearing: 18, 21, 23–25, 28–30 June 2021, 1–2 July 2021 Counsel for the Applicant: Ms K Howard SC with Mr C H Smith Solicitor for the Applicant: Bennett & Philp Solicitors Counsel for the Respondents: Mr J S Cooke with Mr R Clark Solicitor for the Respondents: Maddocks Lawyers ORDERS
QUD 117 of 2019 BETWEEN: VECTOR CORROSION TECHNOLOGIES LIMITED
Applicant
AND: E-CHEM TECHNOLOGIES LTD
First Respondent
NIGEL DAVISON
Second Respondent
ADRIAN CHARLES ROBERTS (and others named in the Schedule)
Third Respondent
ORDER MADE BY:
JAGOT J
DATE OF ORDER:
9 MARCH 2022
THE COURT ORDERS THAT:
1.The amended originating application be dismissed.
2.Subject to orders 3 and 4, the applicant pay the respondents’ costs of the proceeding as agreed or taxed.
3.If a party wishes to vary order 2 the party may file and serve notice of the proposed varied order and a written submission in support, together with any affidavit required, as well as consent to the issue of costs being determined on the papers or a request for a further hearing, within 14 days.
4.Any party served with documents under order 3 may, within a further 14 days, file and serve notice of any proposed varied order sought and a written submission in support, together with any affidavit required, as well as consent to the issue of costs being determined on the papers or a request for a further hearing.
5.Pending further order and pursuant to s 37AF of the Federal Court of Australia Act 1976 (Cth), publication of the reasons for judgment be restricted to the respondents and their legal representatives and the applicant’s external lawyers and Australian barristers retained by or on behalf of the applicant’s external lawyers to act for the applicant in this proceeding who have signed and provided to the respondents’ lawyers a confidentiality undertaking in the form agreed between the respondents and the applicant (the applicant’s external lawyers).
6.Within 7 days, the respondents are to notify the associate to Jagot J and the applicant’s external lawyers of any proposed permanent redactions to the reasons for judgment.
7.Within a further 7 days, the applicant’s external lawyers are to notify the associate to Jagot J and the respondents whether they wish to be heard in respect of the proposed permanent redactions.
Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.
REASONS FOR JUDGMENT
JAGOT J:
1. The application
Vector Corrosion Technologies Limited claims that it is solely or jointly with others entitled to Australian patent No 2006224340 B2 (the E-Chem patent) entitled “Treatment process for concrete”.
E-Chem Technologies Limited is the registered patentee of the E-Chem patent. Dr Nigel Davison, Mr Adrian Roberts and Dr Gareth Glass are the inventors named in the E-Chem patent. They are also the directors and shareholders of E-Chem. Before February 2019 Dr Davison, Mr Roberts and Dr Glass were the registered patentees of the E-Chem patent. They transferred their rights to E-Chem in respect of the E-Chem patent on 25 January 2019.
Where it is not necessary to distinguish between E-Chem and the individual respondents, I refer to the respondents together as E-Chem.
The E-Chem patent was granted on 18 November 2010. It claims priority from documents filed in the United Kingdom in March and October 2005 and January 2006.
Vector contends that it is solely or jointly entitled to the E-Chem patent as a result of its purchase of a corrosion business from Fosroc International Limited (and Fosroc’s related companies) in January 2009.
Between 2002 and 2004 Dr Glass, Dr Davison and Mr Roberts were employees of Fosroc. Dr Glass ceased to be an employee of Fosroc on 8 March 2004. Dr Davison ceased to be an employee of Fosroc on 14 July 2004. Mr Roberts ceased to be an employee of Fosroc on 13 May 2004.
According to Vector, the inventive concept the subject of the E-Chem patent was conceived of by Dr Glass, Dr Davison and Mr Roberts while they were employed by Fosroc. The consequence is that by operation of s 39 of the Patents Act 1977 (UK) the invention would belong to Fosroc. Vector purchased Fosroc’s corrosion business on 29 January 2009 pursuant to contracts including a deed of assignment and a sale and purchase agreement. Vector contends that it purchased from Fosroc the rights in the invention claimed in the E-Chem patent under these contracts. Vector also contends that if this is not so, it purchased those rights from Fosroc under two subsequent contracts, a first addendum dated 9 July 2019 and a second addendum dated 16 September 2019. It follows, on Vector’s case, that it is the “eligible person” to whom a patent for the E-Chem invention may be granted under s 15(1)(c) of the Patents Act 1990 (Cth) (Patents Act) and a declaration to that effect should be made under s 34(1) of that Act.
Vector claims, in the alternative, that to the extent that any of Dr Davison, Mr Roberts and Dr Glass made a relevant inventive contribution to the inventive concept the subject of the E-Chem patent after they ceased to be employed by Fosroc, Vector is jointly entitled to the E-Chem patent with that person. Further or in the alternative, the Register should be rectified under s 192(2) of the Patents Act to record Vector as either the registered sole or joint owner of the E-Chem patent.
In the further alternative, Vector claims revocation of the E-Chem patent on the basis that E-Chem is not entitled to the E-Chem patent.
According to E-Chem, Dr Davison, Mr Roberts and Dr Glass conceived of the inventive concept the subject of the E-Chem patent after they had ceased to be employed by Fosroc and while they were working for their new company, E-Chem. It follows that Fosroc had no rights in respect of the invention and Vector could not purchase any such rights from Fosroc. E-Chem always had those rights.
Vector’s claims must be rejected in their entirety for the following reasons.
2. Statutory provisions
Under s 15(1) of the Patents Act a patent for an invention may only be granted to a person, relevantly, who is the inventor or derives title to the invention from the inventor.
Schedule 1 to the Patents Act provides that an “eligible person”, in relation to an invention, means a person to whom a patent for the invention may be granted under s 15.
Under s 34(1) of the Patents Act, if the Court is satisfied either that “one or more persons are eligible persons in relation to an invention so far as claimed in any claim of the patent (the original claim) but that the patentee is not an eligible person” or that “the patentee and another person or persons are eligible persons in relation to an invention so far as claimed in any claim of the first patent (the original claim)” then the court may declare that “the persons who it is satisfied are eligible persons are eligible persons in relation to that invention so far as so claimed”.
Under s 192(1) of the Patents Act a person aggrieved by, relevantly, an error or defect in an entry in the Register may apply to a prescribed court for an order to rectify the Register. Section 192(2) provides that on hearing an application, the court may make any order it thinks fit for the rectification of the Register. The Commissioner of Patents must be given notice of the application for rectification of the Register under s 192(3) and may appear at the hearing. By s 192(4) a copy of any order must be served on the Commissioner by the Registrar or other appropriate officer of the court. By s 192(5) on receiving a copy of the order the Commissioner must rectify the Register accordingly.
Section 138(1) of the Patents Act provides that a person may apply to a prescribed court for an order revoking a patent. By s 138(3) the court may revoke a patent on grounds including that the patentee is not entitled to the patent. However, s 138(4) provides that a court must not make such an order on the ground that the patentee is not entitled to the patent unless the court is satisfied that, in all the circumstances, it is just and equitable to do so.
3. Principles
In respect of entitlement to a patent in Australian law:
(1)there is a distinction in the authorities between a discovery or an idea (an inventive concept) and the reduction of that inventive concept to practice: University of Western Australia v Gray (No 20) [2008] FCA 498; (2008) 76 IPR 222 (Gray FC) at [1419]–[1443];
(2)“an invention is essentially described by the inventive concept, albeit it may be manifested in the invention as variously claimed”: Gray FC at [1424];
(3)the “inventive concept marks a boundary between invention and verification”: Gray FC at [1426];
(4)“what constitutes the invention can be determined from the particular patent specification including the claims”: Gray FC at [1439];
(5)“[t]he time at which the invention was developed and the person by which it was developed is to be ascertained by reference to the inventive concept of the invention so described. The time of invention, and the identity of the inventor will not be affected by the subsequent process of reduction to practice some elements of which may have found their way into the claims in the application”, albeit recognising that “there may be more than one contributor to the inventive concept and perhaps more than one inventive concept”: Gray FC at [1443], [1442];
(6)the invention or inventive concept of a patent or patent application should be discerned from the whole of the specification including the claims: citing Polwood Pty Ltd v Foxworth Pty Ltd [2008] FCAFC 9; (2008) 165 FCR 527 at [60], affirmed in University of Western Australia v Gray [2009] FCAFC 116; (2009) 179 FCR 346 (Gray FFC) at [222];
(7)“[r]ights in an invention are determined by objectively assessing contributions to the invention, rather than an assessment of the inventiveness of respective contributions. If the final concept of the invention would not have come about without a particular person’s involvement, then that person has entitlement to the invention. One must have regard to the invention as a whole, as well as the component parts and the relationship between the participants”: JMVB Enterprises Pty Ltd v Camoflag Pty Ltd [2005] FCA 1474; (2005) 67 IPR 68 at [132] cited with approval in Polwood at [53];
(8)“…determining inventorship involves a two part inquiry. The starting point is to analyse the inventive concept of the patent applications. The next step is to consider whether …the alleged co-inventor, made contributions that had a material effect on the inventive concept”: Kafataris v Davis [2016] FCAFC 134; (2016) 120 IPR 206 at [62];
(9)entitlement is not determined by reference to the inventiveness of the invention claimed in the patent. It is determined by reference to the history of the inventive concept in the minds of the inventors: Stack v Davies ShephardPty Ltd [2001] FCA 501; (2001) 108 FCR 422 at [19], Vehicle Monitoring Systems Pty Ltd v SARB Management Group Pty Ltd [2021] FCAFC 224 at [68];
(10)“…a person may be considered a joint inventor where they had a general idea of what was required, but someone else was required to put the ideas into effect and did so (Costa v G R & I E Daking Pty Ltd (1994) 29 IPR 241)”; the “key question is whether the person’s contribution had a material effect on the final invention”: Neobev Pty Ltd v Bacchus Distillery Pty Ltd (Administrators Appointed) (No 3) [2014] FCA 4; (2014) 104 IPR 249 at [108];
(11)“[c]urrent Australian case law takes the “inventor”, for the purposes of s 15(1)(a) of the Act, to be the person who is responsible for– in the sense of the person (there may be more than one) who materially contributes to – the “inventive concept””: Vehicle Monitoring Systems at [52];
(12)as to identifying the inventive concept, “[i]t is not possible to be very specific about how this is to be done. But as a general rule one will start with the specific disclosure of the patent and ask whether that involves the use of information which is really that of the applicant, wholly or in part or as a joint owner. … What one is normally looking for is “the heart” of the invention. There may be more than one “heart” but each claim is not to be considered as a separate “heart” on its own”: Vehicle Monitoring Systems at [63] citing Markem Corp v Zipher Ltd [2005] EWCA Civ 267; [2005] RPC 31 at [102];
(13)“…invention may reside in the conception of an idea, without the need for reduction to practice”: Vehicle Monitoring Systems at [73]; or “the inventive concept, derived from the specification as a whole, may be, or include, the manner in which an idea is carried out”: Vehicle Monitoring Systems at [76] citing Polwood at [60]–[61]; and
(14)“[t]he present state of Australian law on entitlement is declared in Polwood…Polwood adopted, without qualification, Crennan J’s observation in JMVB that rights in an invention are determined by objectively assessing contributions to the invention rather than assessing the inventiveness of respective contributions. That approach conforms to principle. The invention or the inventive concept (in Polwood the Full Court appears to have used these terms synonymously) is discerned from the whole of the specification, not just the claims. However, the requirements of s 18 of the Act, dealing with the characteristics of a patentable invention, including (in the case of a standard patent) the need for an inventive step, are directed specifically to the invention as claimed (i.e., as defined by the claims). The question of entitlement is separate to, and distinct from, the question of patentability assessed by reference to the patent claims. It involves a broader inquiry. It stands to reason, therefore, that consideration of the requirements of patentability under s 18 of the Act, including the existence of an inventive step within the meaning of s 7(2) of the Act, is not part of the entitlement calculus”: Vehicle Monitoring Systems at [104].
Contrary to the submissions for E-Chem, it is not the case that an inventive concept necessarily involves the “formation in the mind of the inventor of a definite and permanent idea of the complete and operative invention as it is hereafter to be applied in practice” if, by this, E-Chem intends to suggest that the inventive concept must in fact work or be capable of being reduced to practice. This formulation was cited in Gray FC at [1426] and Polwood at [47]–[50] (citing Shum v Intel Corporation 499 F.3d 1272 (2007) at [6]). However, it is apparent that the characterisation of the inventive concept in Australian law depends on how the specification as a whole identifies the inventive concept, which may or may not include the manner in which an idea is carried out or the reduction of the idea to practice. Gray FFC at [256] does not suggest otherwise. Nor does Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth [2010] FCA 1211; (2010) 88 IPR 459.
Vector is not correct that the manner in which an idea is carried out or its reduction to practice is necessarily irrelevant to the identification of the inventive concept. As the parties otherwise accepted, it is the inventive concept as identified in and by the whole of the specification which is determinative. In Australia, for the purpose of ascertaining entitlement to the patent, this is so whether or not the inventive concept involves a patentable invention (which is a separate and distinct inquiry).
For the same reasons, care is required in respect of E-Chem’s submission that an inventive concept:
…is complete only when the idea is so clearly defined in the inventor’s mind that only ordinary skill would be necessary to reduce the invention to practice without extensive research or experimentation. That is, there can be no invention where a person “comes up with a vague idea … saying “wouldn’t it be nice if we could do such and such””.
This submission elides inventiveness (as essential for patentability) and identification of the inventive concept (relevant to entitlement) when, in Australian law, the two are distinct. The issue is that which the whole specification identifies as the inventive concept. The point in Polwood at [45], that “conception is complete when one of ordinary skill in the art could construct the apparatus without unduly extensive research or experimentation”, again, depends on the nature of what is said by the whole specification to be the inventive concept. This is why the Full Court also said in Polwood at [45] that “[i]t is clear that, in working out the inventive concept in a patent, each patent will be different and it will be necessary to ascertain the inventive concept from the whole of the specification”. What is clear from Polwood at [45], however, is that mere “general goals or a research plan to be pursued are not sufficient” to constitute the inventive concept. This is consistent with the proposition in Gray FC at [1433] that a vague idea (““wouldn’t it be nice if we could do such and such” – but without any idea as to whether “such and such” can in fact be done or how it might be done”, citing Stanelco Fibre Optics Ltd’s Application (No 2) [2005] RPC 16) is not an inventive concept but that an inventive concept may consist of an idea.
This also explains why E-Chem’s reliance on Yeda Research & Development Co Ltd v Rhone-Poulenc Rorer International Holdings Inc [2007] UKHL 43; [2008] RPC 1 requires some caution. It may be accepted that, as Lord Hoffman said in Yeda at [20], the key question to the identification of an inventor is the development of the inventive concept. It must also be the case that, as the whole specification is relevant to identifying the inventive concept, the common general knowledge in the art is relevant as the specification is to be construed through the eyes of the person skilled in the art. More problematic is Lord Hoffman’s observation, also at [20], that “the inventive concept is a relationship of discontinuity between the claimed invention and the prior art”, because this too elides the distinction between inventiveness and entitlement. Again, in Australian law, it is what the whole specification, construed through the eyes of the person skilled in the art who possesses the common general knowledge in that field, identifies as the inventive concept which is determinative.
Otherwise:
(1)as noted, E-Chem contended that Dr Davison, Mr Roberts and Dr Glass conceived of the inventive concept of the E-Chem patent after they had ceased to be employed by Fosroc and while they were employed by E-Chem so that their rights in respect of the patent vested in E-Chem under ss 7 and 39–42 of the Patents Act 1977 (UK). There was no dispute between the parties about the operation of these provisions, the dispute being focused on the time at and by which Dr Davison, Mr Roberts and Dr Glass conceived of the inventive concept of the patent;
(2)E-Chem accepted that if, contrary to its case, Dr Davison, Mr Roberts and Dr Glass had conceived of the inventive concept in whole or in part while they were working for Fosroc, then their rights in respect of the patent vested in Fosroc pursuant to the same provisions of the Patents Act 1977 (UK);
(3)however, E-Chem did not accept that Vector had acquired the rights from Fosroc that would exist in accordance with (2) from Fosroc; and
(4)E-Chem also contended that if, contrary to its case, Vector had acquired those rights from Fosroc, the Court should refuse to grant the relief Vector seeks in the exercise of a discretion under ss 34(1) and 192(2) of the Patents Act given Vector’s inordinate and unjustified delay in seeking such relief; Vector’s other unreasonable conduct; prejudice to E-Chem by reason of Vector’s delay; and the unfair advantage Vector would receive by reason of its delay. Vector denies the existence of any such discretion and disputes E-Chem’s characterisation of the facts.
It was common ground that any rights of Vector obtained through the acquisition of Fosroc’s corrosion business depended on s 39 of the Patents Act 1977 (UK). Section 39 provides that “an invention made by an employee” belongs to an employer in the specified circumstances. It was a common assumption of the parties that an invention is “made by an employee” within the meaning of s 39 once the employee has conceived of the inventive concept of the invention. There was no expert evidence about the content of the law of the United Kingdom in respect of the meaning and operation of s 39 the Patents Act 1977 (UK). Accordingly, the common assumption of the parties, that an invention is “made” for the purposes of determining entitlement once the inventive concept exists in the mind(s) of the inventors (in accordance with Australian law), is appropriate.
As a result, the principal issue between the parties is one of timing, that is, whether Dr Glass, Dr Davison and Mr Roberts conceived of the inventive concept of the E-Chem patent while employed by Fosroc, or whether they did so after they had ceased to be employed by Fosroc and while they were employed by E-Chem. As noted, this issue is not answered by whether the invention the subject of the E-Chem patent is novel or obvious. It is also not answered by whether the E-Chem patent could have been anticipated by an amended version of any earlier patent including patents owned by Fosroc or whether it lacks an inventive step when compared to the prior art. The law of novelty and obviousness are conceptually distinct from the law of entitlement.
I should also record that E-Chem did not plead any potential limitation period issue (and by this I do not suggest E-Chem could have done so).
4. Common general knowledge – technical primer
The parties agreed the terms of a technical primer which they accepted formed part of the common general knowledge of those skilled in the art as at April 2004 (by which time Dr Glass had ceased to be an employee of Fosroc).
The summary below contains extracts from the technical primer.
4.1 The field
The field is products and systems for the electrochemical protection of steel and/or prevention of corrosion in reinforced concrete structures.
4.2 Steel reinforced concrete
Reinforced concrete is concrete in which steel has been embedded in such a manner that the high tensile strength of the steel and the high compressive strength of the concrete work together to allow the structure to sustain stress. The embedded steel is referred to variously as steel reinforcement, reinforcing steel or (steel) “rebar”.
Concrete is formed by mixing cement, aggregate and water. When the cement in a concrete mixture cures, high concentrations of hydroxide (or hydroxyl) ions (OH-) are generated. This causes the concrete, specifically the retained water in capillary pores in the concrete, to become highly alkaline, with a pH typically in the range of 12 or 12.5 to 14.
Steel is intrinsically unstable in that it wants to return to its natural state (commonly iron oxide). The very high alkalinity of the concrete causes a stable iron oxide film to form on the surface of the reinforcing steel. This iron oxide film is referred to as a “passive film” and this condition is referred to as “passivity”.
Whilst the passive film is present, it protects the reinforcing steel from corrosion (more specifically, it slows the corrosion process to a negligible rate). However, when the passive film breaks down, the rate of corrosion will increase. The breakdown of the passive film is typically due to: (a) carbonation, which is the loss of alkalinity (i.e., the reduction of pH) due to reactions with atmospheric carbon dioxide, and/or (b) chloride induced corrosion, which occurs due to the presence of chloride ions in, or introduction of chloride ions into, the concrete structure.
The volume occupied by the products of corrosion can be several times greater than that of the steel they replace. This expansion places significant tensile stress on the cover concrete, leading initially to cracking of the concrete followed by delamination (fracturing of the concrete into layers) and, eventually, spalling (layers or fragments of concrete breaking off).
Corrosion therefore causes the combined failure of the concrete and loss in the cross-section of the reinforcing steel bars. The loss of concrete cover increases the rate of access to the reinforcing steel by aggressive species such as chloride ions, and the loss of steel section reduces the structural strength and load carrying capacity of the structure.
4.3 Corrosion of steel in concrete
Corrosion will normally only occur when the passive conditions within the concrete are lost.
A schematic representation of a “corrosion cell” for reinforcing steel in concrete is shown in the figure below (reproduced from J Broomfield, Corrosion of Steel in Concrete (CRC Press, 1998) page 7, figure 2.1):
A corrosion cell comprises:
(1)an “anode”: This is the site on the reinforcing steel at which metal loss occurs. The typical anodic reaction is the oxidation of iron (Fe) to iron ions (Fe2+). This results in metallic ions entering the electrolyte (i.e., the concrete – see sub-paragraph (3) below) and excess electrons (e-) being produced at the steel. The chemical equation for this reaction shown in the figure above is Fe Fe2+ + 2e-;
(2)a “cathode”: This is the site on the reinforcing steel at which the excess electrons produced at the anode can be consumed to conserve charge. The typical cathodic reaction, in neutral and high pH environments, is the reduction of dissolved oxygen (O2) in water (H2O) to produce hydroxide ions (OH-). The chemical equation for this reaction shown in the figure above is ½O2 + H2O + 2e- 2OH-;
(3)an “electrolyte” (i.e., the water and ions in the capillary pores of the concrete) through which current is carried by ions such as chloride ions (Cl-), hydroxide ions (OH-) and other ions (Na+, H+, Ca2+ etc); and
(4)a metallic path (i.e., the reinforcing steel) connecting the anode and the cathode through which the electrons travel.
By convention, current flows in the direction of movement of positive charge carriers (e.g., positive ions); that is, in the opposite direction to the movement of negative charge carriers (e.g., electrons). Thus, in a corrosion cell: (a) current flows from the anode to the cathode via the electrolyte (i.e., ionic current); and (b) current flows from the cathode to the anode via the metallic path (i.e., electronic current).
The reactions involved in the process of corrosion are, therefore, both chemical and electrical, and the process is referred to as an electrochemical process.
4.4 Carbonation
Carbonation is a process by which the alkaline conditions within the concrete are lost due to reaction with atmospheric carbon dioxide.
Carbon dioxide reacts with water in the pores of the concrete to produce carbonic acid, which in turn reacts with calcium hydroxide within the cement paste to produce calcium carbonate. When all the locally available calcium hydroxide (which contributes to the high pH of the concrete) is consumed, hydroxide ions are removed from solution, causing the pH to decrease. At this lower pH, the passive film surrounding the reinforcing steel breaks down, reducing its corrosion resistance.
Since water is essential for carbonation to occur, the reaction of carbon dioxide and calcium hydroxide only occurs in solution. Therefore, in very dry concrete, carbonation will be slow. Similarly, in saturated concrete, the moisture presents a barrier to the penetration of carbon dioxide, resulting in a slow rate of carbonation.
4.5 Chloride ingress
Chloride ingress describes the introduction of chloride ions into the concrete structure where they may break down the passive film at the steel surface.
Unlike carbonation, where the pH decreases, in the chloride attack mechanism, the chloride ions attack the passive layer by acting as a catalyst to corrosion reactions, allowing the corrosion process to proceed quickly. In this process, the surface of the steel acts as an anode and the passive surface layer acts as the cathode. If chloride ions penetrate the concrete to the steel reinforcement and accumulate to a sufficient concentration, and water and oxygen are present, then corrosion of the steel reinforcement will occur.
The presence of chloride ions at the steel surface can result in localised high-rate corrosion. As with carbonation, the rate of corrosion caused by chloride ingress is dependent on time, depth and concrete quality (durability). That is, the rate of increase in chloride concentration through the concrete to the embedded steel reinforcement slows with depth and increases with reduced concrete quality.
Any significant corrosion of the steel surface can create a significant volume of expansive corrosion product, which can create a bursting force inside the concrete.
4.6 Repair of reinforced concrete
Options for the remediation of concrete damaged by reinforcement corrosion include concrete repair and the application of an electrochemical repair technique.
With patch repairs, chlorides will remain in concrete surrounding the repair and, once repairs have been carried out, the reinforcement in surrounding areas can quickly corrode and cause further deterioration.
Removing chloride-contaminated concrete and replacing it with fresh concrete is more likely to succeed than simply patching visual defects, but this may result in the removal of large quantities of concrete which are contaminated but otherwise sound and, where the repair is extensive, the need for temporary structural support. As such, the cost of this approach may be prohibitive or impractical.
There is a period before extensive damage occurs on a structure where intervention (such as an electrochemical treatment) can be applied to arrest or reduce ongoing corrosion without major repair works.
4.7 Electrochemical repair techniques
4.7.1Overview
Electrochemical treatments are intended to suppress corrosion across the entire treated structure.
Four different kinds of electrochemical treatments were in common use:
(1)impressed current cathodic protection (ICCP);
(2)sacrificial anode cathodic protection (SACP);
(3)chloride extraction; and
(4)realkalisation.
All electrochemical treatments rely upon the same basic electrochemical principle of using an anode to apply a current to the steel reinforcement to cause a cathodic reaction at the steel. Each approach applies this principle in a different way to achieve a different objective.
Cathodic protection (ICCP and SACP): this involves or commonly involves the application of a small current (conventionally at a current density of between about 2 to 20 mA/m2 steel surface area) via an anode to shift the steel potential for the lifetime of the structure, e.g., 100 years. While the only reaction on the steel surface is the cathodic reaction, corrosion is suppressed and the steel is said to be under “cathodic protection”. The cathodic reaction also produces hydroxide ions (OH-) at the steel, which over time increases the pH near the steel and assists to restore and maintain the stable iron oxide film layer at the steel.
The same principles apply to new structures (i.e., those not undergoing corrosion conditions) where the application of cathodic protection was sometimes referred to as “cathodic prevention”. In this case, a lower current density (conventionally of about 0.2 to 2 mA/m2 steel surface area) is intended to maintain passive conditions and, hence, prevent corrosion.
ICCP and SACP systems are intended to provide corrosion protection for as long as the systems remain functioning and in place, which may be measured in decades.
Chloride extraction and realkalisation: these treatments involve the application of significantly higher current density (conventionally between about 500 and 1000 mA/m2 steel surface area or more) than ICCP or SACP over a period of days (for realkalisation) or weeks (for chloride extraction). The treatment is then stopped and the system is entirely removed from the structure. These temporary electrochemical treatments aim to alter the chemical make-up of the concrete to return it to a state in which the conditions around the steel restore passivity (i.e., lower chloride concentration (for chloride extraction) or higher pH (for realkalisation)).
After chloride extraction or realkalisation treatments have been performed, chloride ions can migrate back to the steel over time and the pH can fall again over time due to ongoing carbonation.
4.7.2Impressed current cathodic protection (ICCP)
In ICCP, an external direct current (DC) power source is used to apply a small current to the steel via an anode. Typically, an impressed current anode is made from an essentially inert material that can pass charge over a long period of time without losing significant mass (i.e., corroding), such as a mixed metal oxide (MMO)-coated titanium anode.
The impressed current anode is either in contact with, or embedded in, the concrete. Two diagrammatic representations of an ICCP system are shown below (reproduced from Broomfield, page 108, figure 6.1 (top); and Paul M Chess (ed), Cathodic Protection of Steel in Concrete (E & FN SPON, 1998) page 115, figure 6.2(b)):
The power supply passes enough current from the anode to the reinforcing steel to force the anodic reaction at the steel to stop (or reduce it to negligible levels) and make the cathodic reaction the only significant reaction occurring on the steel surface. The production of hydroxide ions increases the pH and assists to restore the passive layer at the steel. For as long as current is supplied to the steel reinforcement in this way, the steel reinforcement is maintained in a cathodic state and corrosion is suppressed.
Normally, the DC source for an ICCP system is provided by mains (AC) power with a transformer-rectifier and other control and monitoring systems. Rechargeable batteries (e.g., charged by solar cells) were also used as a source of DC power in ICCP systems.
ICCP systems require a constant and reliable power source and regular monitoring and maintenance to ensure that the system is applying the required current density to the steel reinforcement. If the required current density is not being achieved, the amount of current could be increased by using a higher operational voltage. ICCP systems, therefore, can be used where the conductivity of the concrete is low (i.e., concrete resistivity is high).
4.7.3Sacrificial anode cathodic protection (SACP)
SACP works by coupling to the steel a galvanic (or sacrificial) anode, which is a metal that is more electrochemically active than steel (such as zinc, aluminium or magnesium or an alloy of these metals). A diagrammatic representation of an SACP system is shown below (Chess, page 115, figure 6.2(a)):
The sacrificial anode is electrically connected to the steel (e.g., via a wire) and is attached to the surface of the concrete or embedded in the concrete. This forms an electrochemical cell and the potential difference between the sacrificial anode and the steel causes a current to flow. The anodic reaction results in positively charged metal ions (e.g., zinc (Zn) to zinc ions (Zn2+)), which travel through the concrete to the steel, and negatively charged electrons, which travel through the electrical connection to the steel, to be taken up in the cathodic reaction. The cathodic reaction yields hydroxide ions, which increases the local alkalinity at the steel and, hence, strengthens the passive layer.
In this process, the anode is consumed (i.e., it corrodes, thereby “sacrificing” itself to protect the steel), hence the term “sacrificial anode”.
In comparison to ICCP systems, SACP systems (dependent on the type) can be much easier and cheaper to install. SACP systems do not require a source of DC power, or any external wiring or monitoring system.
The principal operating disadvantage of SACP systems is the relatively low driving voltage between the sacrificial anode and the steel, which is fixed and cannot be regulated. The current from the anode is dependent on the driving voltage and the anode resistance (which is dependent on anode shape and the concrete resistivity). The application of SACP, therefore, is limited by the resistivity of the concrete (which can be relatively high in normal, dry environments) and the size of the anode that can be used.
4.7.4Chloride extraction
Chloride extraction is a temporary electrochemical treatment designed to extract chloride ions from the concrete, thus reducing the concentration of chloride ions at the surface of the steel. Chloride extraction, therefore, is an option for use on reinforced concrete structures which have been contaminated with chlorides.
Chloride extraction treatments require different equipment to cathodic protection systems. In particular, an electrolyte-containing medium (typically a tank, a felt mat or sprayed cellulose fibre) is mounted on the surface of the concrete structure. The anode is located in the electrolyte-containing medium.
During the treatment, the very high current density (between about 500 and 1000 mA/m2 steel surface area or more) applied to the steel increases the negative charge on the steel, essentially repelling negatively charged chloride ions, which migrate toward the anode and, thus, are removed at the surface of the structure into the electrolyte solution.
At the end of the treatment (typically up to four to six weeks or so), the power supply, the anode and electrolyte-containing medium are removed.
4.7.5Realkalisation
Realkalisation is a temporary electrochemical treatment designed to generate an excess of hydroxide ions at the steel, thus re-establishing the alkalinity (high pH) at the surface of the steel. Realkalisation, therefore, is used on reinforced concrete structures in which the pH has been reduced, typically by carbonation (which results in the generation of acid and, hence, reduction in pH).
In realkalisation, a similar setup to that in chloride extraction is utilised, with the anode located in an electrolyte-containing medium mounted on the surface of the concrete structure (again, typically a tank, a felt mat or sprayed cellulose fibre). A difference is that, in realkalisation, the electrolyte may contain sodium or lithium carbonate which diffuses into the concrete structure and aids in restoring the high pH and in making the structure more resistant to further carbonation.
At the end of the treatment (typically around four to eight days), the power supply, the anode and electrolyte-containing medium are removed.
4.8 Applicable standards
Detailed requirements for the design and implementation, commissioning, control and monitoring of impressed current cathodic protection and prevention systems for reinforced concrete structures were described in: Australian Standard AS 2832.5-2002 “Cathodic protection of metals – Part 5: Steel in concrete structures”; National Association of Corrosion Engineers (NACE) Standard Recommended Practice RP0290-2000 “Impressed Current Cathodic Protection of Reinforcing Steel in Atmospherically Exposed Concrete Structures”; and European Standard EN 12696:2000 “Cathodic protection of steel in concrete”.
Detailed requirements for the design and implementation, commissioning, control and monitoring of chloride extraction and realkalisation for reinforced concrete structures were described in: NACE International Technical Committee Report “Electrochemical Chloride Extraction from Steel Reinforced Concrete – A State of the Art Report” published by NACE International in May 2001 and NACE International Technical Committee Report “Electrochemical Realkalization of Steel Reinforced Concrete – A State of the Art Report” published by NACE International in April 2004.
4.9 Further observations about the common general knowledge
Vector stressed that while there are four commonly used categories of electrochemical treatment: (a) they are all based on the same basic electrochemical principle of using an anode to apply a current to the steel reinforcement to cause a cathodic reaction at the steel, (b) they all cause the same chemical processes and changes to occur on and around the surface of the steel reinforcing, and (c) the changes (the reactions and movement of ions) that occur do not depend on the type of DC power source that is used. Vector referred in this regard to expert witness Dr David John’s evidence that “the steel itself doesn’t know where the current is coming from … it just knows how much current it is receiving”.
All this may be accepted at one level of generality. However, it would be wrong not to recognise that it was common general knowledge of the person skilled in the art that electrochemical techniques for corrosion treatment fell into two distinct groups: (a) cathodic protection comprising ICCP and SACP, and (b) temporary electrochemical treatments comprising realkalisation and chloride extraction. It would also be wrong not to recognise that each approach applies the principle of using an anode to apply a current to the steel reinforcement to cause a cathodic reaction at the steel “in a different way to achieve a different objective” (to use the words of the agreed technical primer).
E-Chem is thus correct that the mental landscape of the person skilled in the art, as a result of the common general knowledge, involved two distinct classes of electrochemical treatment which may be represented as follows (figure extracted from the affidavit of Dr John affirmed on 29 October 2019):
E-Chem is also correct that the common general knowledge included that cathodic protection was a permanent (so far as possible) treatment with a continuous low current (a current density of between about 2 to 20 mA per m2 of steel surface area), the current being either: (a) supplied by an external power source via an impressed current anode in ICCP; or (b) caused by coupling of a galvanic (sacrificial) anode to the steel in SACP.
It follows that while the “the steel itself doesn’t know where the current is coming from … it just knows how much current it is receiving”, the person skilled in the art had to know where the current was coming from in order to decide on the appropriate system of treatment for the reinforced concrete in question.
The expert evidence supports these propositions.
Dr Bruce Ackland is a corrosion engineer and consultant with over 37 years’ experience, holding a Bachelor of Science with Honours in Physics (1979) and a PhD in Materials Engineering (1984), and has conducted continuous work in the field since 1982.
Dr John is a corrosion engineer and consultant with over 40 years’ experience in the field in the United Kingdom and elsewhere holding a Bachelor of Science with Honours (1975) and a PhD concerning corrosion science (1979), and has conducted continuous work in the field since 1978.
Dr Ackland explained that an impressed current anode as used in ICCP necessarily involved an external power supply. As he put it (emphasis added):
As at 2004 we had a definition in our Australian standards of a – what an impressed current is, and that definition is you’re supplying direct current by means of an external power supply, and my understanding in 2004 of an external power supply was a power supply such as ..... transformer required to plug into mains power. If you’re in a remote location where you haven’t got AC power readily available it might be a solar powered, multicell, rechargeable battery system. Whatever it ..... be quite a substantial power supply delivering current to, usually, multiple anodes, and, in accordance with our definition, located external to the concrete.
Dr John said:
The majority of DC power supplies used for impressed current cathodic protection systems, whether for steel and concrete or elsewhere, would have been either traditional transformer rectifiers, which do as it says – they transform AC voltage from hundreds of volts down to typically 20 or 30-odd volts – and then also rectify it from AC to DC, and those are typical systems which could either be single phase or three phase, depending upon the power. At the time of the low-2000s, the traditional TRs were being replaced by solid state devices, but the majority of them would be that way.
There were cases, of course, even at that time where in remote areas, where AC mains is not available, people were looking at alternative power supplies, either solar or wind, typically using that to charge a battery to power the power supply, and in one particular project I was working on in Israel, we did initially use that, which was solar panels to trickle charge a battery to then power the system, but that had to be replaced after a year because people kept stealing the solar panels. So in those cases, we then just left with a very large rechargeable battery, which was replaced every three months… it’s what’s called a tractor battery, which is about the size of 50 car batteries. You know, big.
Understanding this for the person skilled in the art would have been essential common general knowledge, as would have been the consequence that ICCP treatment requires a constant and reliable power source and regular monitoring and maintenance over the life of the structure to ensure that the system is applying the required current density to the steel reinforcement.
In contrast, in SACP treatment, the current arises from the fact that a galvanic (or “sacrificial”) anode is more electrochemically active than the steel reinforcement it is being used to protect, so that the sacrificial anode preferentially undergoes the anodic reaction, resulting in the cathodic reaction at the steel, with the sacrificial anode connected to the steel via a steel wire, cable or strap. The person skilled in the art would know as a matter of common general knowledge that SACP does not require a source of DC power or any external wiring, control or monitoring system. As such, without the control, monitoring and maintenance of ICCP, sacrificial anodes could be much cheaper and easier to install, and have lower ongoing costs as there is no need for periodic maintenance.
Further, it was part of the common general knowledge that because the current potential of SACP depends on the operating potential of the anode, the potential of the embedded steel, and the resistivity of the concrete, the current output cannot be regulated. The result was that SACP was rarely used in normal dry (or inland) environments due to the high resistivity of concrete under these conditions. Also, and accordingly, ICCP and SACP were not interchangeable and equally available treatment alternatives.
The mental landscape of the person skilled in the art also included the common general knowledge that chloride extraction and realkalisation are temporary electrochemical treatments which do not provide ongoing electrochemical protection against corrosion. They aim to alter the chemical make-up of the concrete to return it to a state in which the conditions around the steel rapidly restore passivity (i.e., lower chloride concentration (for chloride extraction) or higher pH (for realkalisation)).
Dr John explained it this way:
… it is fully accepted that the fundamental electrochemical reactions occurring in all these four systems – Galvanic, CP, impressed current CP, electrochemical chloride removal, electrochemical realkalisation – the fundamental reactions are the same. The biggest difference, as I have just stated, is the impact of the magnitude of those reactions, which is very much dependent upon which way you’re coming from… the cathodic protection system, you are basically aiming to provide a continuous power or electricity to suppress the corrosion reaction occurring on the steel… you’re applying that literally for the life of this system, 25-50 years or above…
Cathodic protection systems also involve a “completely different engineering requirement, both in terms of how you physically apply the system, how you operate the system, the amount of power you have to supply over that period of time, and so on” if compared to the temporary protection systems. Further, in Dr John’s words:
…once you stop applying the temporary protection system, whilst you will have changed the conditions significantly ..... corrosion will have stopped, that is not in itself a permanent solution because with time the natural environment can re-establish itself, chlorides can migrate back, carbonation can re-proceed, etcetera, so that therefore corrosion be expected to reoccur at some point in the future.
As E-Chem noted by reference to the joint expert evidence, for cathodic protection, AS 2832.5-2002 specifies a current density of 2 to 20 mA/m2 of steel surface area, although the “typical range of operation” for ICCP is 10 mA/m2 of steel surface area. This could then be reduced in time or if the structure is new and not corroding, in which case “the current densities we used might be less than [1 mA/m2]”. The temporary electrochemical treatments, on the other hand, require “hundreds or even thousands of [mA/m2]. It’s many orders of magnitude greater”.
Dr Ackland said that for cathodic protection there are minimum current densities so that the “moderation of chlorides away from the steel will exceed in normal diffusion of chlorides towards the steel, and you get a net migration” whereas the “impact of the tremendously high current density that is used for chloride extraction and realkalisation, the processes that are occurring – the electrochemical processes that are occurring in the steel are substantially different to what would initially occur for a regular cathodic protection system”. He explained:
Well, the normal current densities that we would use for a permanent, fulltime cathodic protection system would be in the range – the upper level would be – in terms of actual operation – would be maybe 10 milliamps per square metre, reducing to, for a system applied to a structure that’s not corroding yet, that’s passive, would be, you know, maybe one milliamp per square metre or less. Plus or minus. So that sort of one to 10 milliamp per square metre range is our typical range of operation. In these temporary treatments it’s hundreds or even thousands of milliamps per square metre. It’s many orders of magnitude greater.
And the effect of that is totally different to the effect of the smaller current densities that we apply for fulltime cathodic protection. …but…there are issues with applying these very, very high current densities. You can get hydrogen embrittlement in susceptible steels. You can lose bond between the bar and the concrete. And those detrimental effects don’t occur with cathodic protection. So not only are the beneficial effects the same, but all these detrimental effects are totally different. That’s what I meant by totally or particularly different.
Dr John also explained that while the fundamental electrochemical reactions are essentially the same for all four systems, the magnitude of reactions differs for each approach and it is the “magnitude of the difference which is one of the factors which differentiates the different approaches”.
For these reasons, all of the expert evidence establishes that in the mind of the person skilled in the art there was a conceptual, purposive, practical and regulatory divide between cathodic protection systems and temporary protection systems.
This part of the mental landscape of the person skilled in the art is also reflected in the fact that the standards applying to the approaches are themselves divided into two separate categories – those relating to cathodic protection (which exclude the temporary treatments) and those relating to chloride extraction and realkalisation (the temporary treatments).
5. The inventive concept of the E-Chem patent
As noted, the E-Chem patent is to be construed through the eyes of the person skilled in the art and in light of the common general knowledge.
The specification identifies the technical field as “the electrochemical treatment of reinforced concrete to protect it from deterioration arising from corrosion of the steel” and that the invention is concerned with “a hybrid electrochemical treatment to arrest steel reinforcement corrosion and subsequently prevent corrosion initiation”.
The specification identifies the background art in terms which reflect the common general knowledge as described above. Accordingly, the background art is said to include that:
(1)both sustained and temporary electrochemical treatments have been used to arrest corrosion of steel in reinforced concrete;
(2)sustained or long-term electrochemical treatments are installed with the intention of maintaining the treatment for the foreseeable future and a well-known family of sustained or long-term techniques is cathodic protection which includes impressed current cathodic protection and sacrificial cathodic protection. In these techniques a long-term or permanent anode delivers a small current to the steel reinforcement. Average current densities expressed per unit area of steel surface typically range from 2 to 20 mA/m2 to arrest existing deterioration and 0.2 to 2 mA/m2 to prevent the initiation of deterioration;
(3)temporary or short term electrochemical treatments are installed with the intention of discontinuing the treatment in the foreseeable future. The electrochemical treatment period would typically be measured in days, weeks or months. These techniques include chloride extraction and realkalisation. In these systems a temporarily installed anode system is used in conjunction with a temporary DC power supply to deliver a large current of the order of 1000 mA/m2 expressed per unit area of steel surface for a short period (typically less than three months) to the steel reinforcement;
(4)anodes for concrete structures may be divided into inert anodes or sacrificial anodes;
(5)a widely used inert anode system is a MMO-coated titanium mesh embedded in a cementitious overlay on the concrete surface;
(6)sacrificial anodes are consumed in the process of delivering the protection current. The main anodic reaction is the dissolution of the sacrificial metal. As a result, the life of sacrificial anodes is limited. The use of sacrificial anodes in an impressed current role is deterred by the more rapid consumption of the anode in this role;
(7)temporary anode systems are usually attached to the concrete surface to deliver short term high current temporary electrochemical treatments and are removed at the end of the treatment period that is typically less than three months. Temporary anodes are surrounded by a temporary electrolyte, such as a liquid contained in a tank or an electrolytic material such as saturated cellulose fibre, that is easily removed at the end of the treatment process. A high drive voltage together with a high volume of electrolyte is generally needed to support the high current output; and
(8)by contrast, long-term anode systems, intended to deliver a protection current over several years, are strongly attached to the concrete and may be embedded in cavities in the concrete to improve anode attachment.
The specification provides a disclosure of the invention starting with a description of the “technical problem”. This section says:
(1)impressed current cathodic protection is the most proven of the existing methods of arresting chloride induced corrosion of steel in concrete. However it requires a high level of maintenance when compared with other inspection or maintenance requirements of reinforced concrete structures and while the low current densities used in impressed current cathodic protection eventually arrest corrosion, corrosion-induced damage continues to occur until the corrosion process is arrested;
(2)temporary electrochemical treatments rapidly arrest the corrosion process and have no maintenance requirements after the initial treatment but a substantial level of chloride sometimes remains, there are concerns regarding the durability of such treatments in chloride containing environments, and the duration of the treatment may last several months and access to the treated surface is restricted during this time;
(3)sacrificial cathodic protection is not always considered to be powerful enough to arrest corrosion. However it is a low maintenance, reliable process that can be used in a preventative role; and
(4)the problem solved by this invention is the efficient delivery of powerful electrochemical protection treatments to corroding steel in concrete to arrest corrosion and to achieve long-term durability of the protective effects with minimal maintenance requirements and minimal disruption during system installation.
The next section in the disclosure of the invention concerns the “technical solution”. This section says:
(1)existing electrochemical treatments may be improved by splitting the treatment into two phases; namely, a brief initial high current treatment to rapidly arrest corrosion minimising further damage, and a subsequent long-term preventative treatment with low maintenance requirements to sustain passivity and ensure durability;
(2)a single multiple treatment anode that is capable of delivering both the initial high current, short term electrochemical treatment to arrest corrosion and subsequently the long-term, low current treatment to prevent subsequent corrosion initiation is disclosed;
(3)to deliver the initial high current treatment, the multiple treatment anode is capable of delivering very high current densities off the anode surface at low safe DC voltages. To achieve a durable long-term preventative treatment the multiple treatment anode is used in a cathodic prevention role, preferably connected to the steel as a sacrificial anode;
(4)the multiple treatment anode is based on the use of a sacrificial anode metal in a temporary high impressed current role. One observation leading to the development of the multiple treatment anode was that an aluminium alloy sacrificial anode metal can deliver current densities in excess of 10,000 mA/m2 (expressed per unit of anode area) off the anode surface at very low safe DC voltages that are not sufficiently positive to induce gas evolution even when the sacrificial anode is embedded in a porous material in a cavity formed in reinforced concrete. This is possible because the anodic reactions occur easily on sacrificial anode metals when compared with the anodic reactions occurring on inert impressed current anodes. Very high current density compact discrete anodes may therefore be embedded in the concrete to limit the disruption caused during the brief high impressed current treatment. A brief high impressed current treatment moves corroding sites from locations on the reinforcing steel to installed sacrificial anodes because hydroxide is produced at the steel causing the pH to rise and aggressive ions like chloride and sulphate are drawn from the concrete to the sacrificial anode. The anode may be subsequently used as an activated sacrificial anode to maintain steel passivity;
(5)accordingly, the present invention provides in a first aspect, a method of protecting steel in concrete that comprises using an anode and a source of DC power and a temporary impressed current treatment, and a low current preventative treatment wherein the temporary impressed current treatment is a high current treatment using the source of DC power to drive current off the anode to the steel to improve the environment at the steel and the low current preventative treatment is applied to inhibit steel corrosion initiation after the application of the temporary impressed current treatment and the same anode is used in both treatments and the anode comprises a sacrificial metal element that undergoes sacrificial metal dissolution as its main anodic reaction;
(6)another observation leading to the development of multiple treatment technology was the high charge density of aluminium alloy anodes. Four aluminium alloy anodes 100mm long and 15mm in diameter have sufficient charge to deliver approximately 500 mA for one week and 1 mA for 50 years in their impressed current and sacrificial anode functions. The high charge density of some sacrificial anodes means that long lives are achievable from small sacrificial anodes embedded in concrete. This alleviates the concerns regarding the costs of replacing the anodes embedded in porous materials at the end of their service lives; and
(7)the inclusion of an impressed current anode connection detail on a compact discrete sacrificial anode alleviates the risk of corroding the connection when the discrete sacrificial anode is used as an impressed current anode. Forming the sacrificial anode metal around an impressed current anode that may be used in an impressed current cathodic prevention role after the sacrificial metal has been consumed may also be used to extend the life of the treatment.
The specification then describes the advantageous effects of the invention. These are that:
The anodic reactions occurring on a sacrificial metal occur more easily than the anodic reactions occurring on an inert anode and require less driving voltage and generate less acid and less gas. This enables a brief high current electrochemical treatment to be delivered more easily. The application of a high current to a steel cathode of an electrochemical cell rapidly arrests corrosion of the steel minimising further corrosion damage. Aggressive ions in the concrete are drawn to the anode by the impressed current treatment. The combination of these aggressive ions and the sacrificial metal forms a sacrificial anode that is activated without the addition of other activating chemicals to the concrete. Connecting this sacrificial anode directly to the steel provides a simple method of applying a continuous, preventative treatment to inhibit future corrosion initiation. The corroding areas are effectively moved from the steel to the installed anode during the initial treatment. Embedding an anode system within the concrete allows the concrete surface to be used while the high impressed current electrochemical treatment is applied.
A section called “Mode for Invention” follows the drawings (see below). The section says, under the sub-heading “Mechanism of Electrochemical Protection”:
(1)the traditional understanding of reinforced concrete electrochemical treatments is that different treatments rely on different protective effects induced by a negative driven potential shift that inhibits the dissolution of steel to form positive iron ions (corrosion), the removal of chloride ions from the steel surface that renders the environment less aggressive to passive films on steel, and the generation of hydroxyl ions at the steel surface that stabilises the formation of passive films on steel;
(2)the collation and analysis of the available evidence suggests that one protective effect is likely to have a dominant effect on the success of all electrochemical treatments applied to steel in atmospherically exposed concrete. This dominant protective effect is the increase in pH at the steel/concrete interface;
(3)the importance of the generation of hydroxyl ions at the steel is supported by a number of observations including the surprising observation that induction of open circuit steel passivity is achieved using cathodic protection current densities that are substantially lower than the localised steel corrosion rates; and
(4)analysis suggests that the range of charge densities applied to reinforcing steel in concrete to induce open circuit steel passivity may be an order of magnitude below that previously postulated to be necessary.
The next sub-section concerns “Improving the Electro-chemical Treatment Process”. This says that:
(1)it has been noted above that relatively low charge densities may be used to restore steel passivity. A temporary electrochemical treatment process to arrest corrosion may therefore be substantially less intensive than the very intense temporary electrochemical treatments sometimes applied. In particular, the period of a temporary electrochemical treatment may be reduced. Thus a temporary electrochemical treatment may be applied for less than three months and preferably less than three weeks. However, the durability of a short term treatment will be questioned despite the immediate reduction in corrosion rate. Such a brief initial treatment would be more acceptable if a supplementary long-term corrosion prevention treatment was applied;
(2)an improved treatment process would therefore be a hybrid electrochemical treatment in which an initial charge density that is sufficient to arrest corrosion and induce open circuit steel passivity was applied and followed by a low maintenance cathodic prevention treatment to prevent any subsequent corrosion initiation. It would be advantageous to use the same anode system in both the powerful impressed current treatment to arrest corrosion and in the subsequent low maintenance treatment to maintain steel passivity; and
(3)average current applied during the initial impressed current electrochemical treatment will typically be at least an order of magnitude greater than the average current subsequently applied during the low current preventative treatment. The low current preventative treatment will usually involve the delivery of an average current density of less than 5 mA/m2 and more than 0.2 mA/m2 to the steel surface.
The next sub-section, “Treatment Technology”, describes aspects of the invention and preferred embodiments and examples, which are all encompassed by the first aspect of the invention which is described as follows:
… a method of protecting steel in concrete that comprises using an anode and a source of DC power and a temporary impressed current treatment and a low current preventative treatment wherein the temporary impressed current treatment is a high current treatment using the source of DC power to drive current off the anode to the steel to improve the environment at the steel and the low current preventative treatment is applied to inhibit steel corrosion initiation after the application of the temporary impressed current treatment and the same anode is used in both treatments and the anode comprises a sacrificial metal element that undergoes sacrificial metal dissolution as its main anodic reaction.
The next section in the specification concerns industrial applicability. This section notes that standards applicable to the invention include BS EN 12696: 2000 (Cathodic protection of steel in concrete) and prCEN/TS 14038-1 (Electrochemical realkalisation and chloride extraction treatments for reinforced concrete).
The claims of the E-Chem patent include claim 1 as follows:
Use of an anode and a source of DC power to protect steel in concrete construction which use comprises driving a current off the anode to the steel using the source of DC power to deliver a temporary impressed current treatment adapted to improve the environment at the steel to arrest steel corrosion and subsequently delivering from the same anode to the steel a low current preventative treatment adapted to inhibit steel corrosion initiation wherein the temporary impressed current treatment is a high current treatment relative to the low current preventative treatment and the anode comprises a sacrificial metal element that undergoes sacrificial metal dissolution as its main anodic reaction.
Figure 1 below shows a schematic diagram of the use of an anode in a hybrid impressed current sacrificial electrochemical treatment, as it appears in the patent claims:
In this figure a sacrificial metal element [1] is embedded in a porous material [2] containing an electrolyte in a cavity [3] formed in concrete [4]. The sacrificial metal element is connected to the positive terminal of a source of DC power [5] using an electrical conductor [6] and electrical connection [7]. An impressed current anode connection detail is used to connect the sacrificial metal element [1] to the electrical conductor [6].
This preferably involves forming the sacrificial metal element around a portion of a conductor [8] that remains passive during the impressed current treatment. The conductor [8] provides a convenient connection point [9] away from the sacrificial metal to facilitate a connection to another electrical conductor. The negative terminal of the power source [5] is connected to the steel [10] using an electrical conductor [11] and connection [12]. While the power supply is connected to the anode and the steel, electrical connection [13] is not made. The description in the specification continues:
Initially a large, short term impressed current is driven from the anode assembly [1, 8] to the steel [10] for a brief period using the source of DC power [5]. In the process oxygen and water [14] are converted into hydroxyl ions [15] on the steel. This neutralises the acidic corrosion sites and promotes the repair of the protective passive film on the steel. In addition, aggressive ions such as chloride ions [16] are drawn from the concrete into the porous material [2] around the anode. The local environments around the embedded steel and around the embedded anode are modified by this brief impressed current treatment. The changes mean that the local environment at the steel supports steel passivation while the environment at the anode maintains sacrificial anode activity. The corroding sites are effectively moved from locations on the steel reinforcement to the installed sacrificial anode. At the end of the impressed current treatment, a long term low power cathodic prevention treatment may then be applied using the same anode.
It is preferable to disconnect the power supply [5] at electrical connections [7] and [12] and to connect remaining sacrificial anode metal directly to the steel through electrical connection [13]. The activated discrete sacrificial anode formed by the temporary impressed current treatment is then used in a long term sacrificial cathodic prevention role to maintain steel passivity. This is preferable because the current output of sacrificial anodes is more reliable than that of a DC power supply and is to some extent self adjusting with more aggressive environments leading to higher sacrificial anode current outputs. Furthermore, monitoring is not critical to sacrificial anode system function and can be tailored to compliment end user requirements for the protected structure. A simple method of monitoring performance uses non destructive potential mapping techniques to determine whether the only areas of anodic activity are located at the sites where the discrete sacrificial anodes are embedded.
The connections [7, 9, 12, 13] and conductors [6, 8, 11] are all electron conducting connections or conductors in that they provide a path for electrons to move. They may be referred to as electronic connections or electronic conductors. The conductors would typically be wires or electrical cables. These conductors and connections differ from ionic conductors or ionic connections. The electrolyte in the concrete [4] provides an example of an ionic connection between the sacrificial metal element [1] and the steel [10]. To achieve sacrificial cathodic protection or prevention, both an electronic connection and an ionic connection between the sacrificial metal element and the steel are required.
The sources of DC power [5] for the brief high current treatment include a mains powered DC power supply or a battery. It is an advantage if the connection between the anode and the positive terminal of the power supply is kept as short as possible to minimize the corrosion risk to this connection.
The inventive concept of the E-Chem patent was described as follows by Dr Ackland and Dr John:
… the E-Chem Patent describes a method of providing corrosion protection to steel reinforcement utilizing:
•Use of multiple-treatment anodes, which are discrete, embedded, sacrificial (galvanic) anodes.
•A first, temporary, treatment whereby the discrete anodes are operated in an impressed current manner, to provide a high current (from an external power supply) to the steel reinforcement to restore passivity on the steel.
•A second, long-term treatment, whereby the power supply has been removed and the discrete sacrificial (galvanic) anodes are then connected directly to the steel reinforcement to provide a lower current to maintain the passive conditions.
The overall Inventive Concept is the combination of these the two treatments to form a Hybrid system.
This characterisation of the inventive concept of the E-Chem patent reflects the terms of the E-Chem patent and the common general knowledge. Importantly, the heart of the invention described in the specification and claims is the use of the same anode in two modes – in the first phase, for a short period, using a high impressed current (but not as high as the current densities of existing temporary treatments) supplied through an external power source to the anode and, in the second phase, using the same anode as a sacrificial anode to generate a continuous low galvanic current to maintain the passive conditions induced by the first treatment phase.
While the issue is not whether the inventive concept of the E-Chem patent is inventive, it is apparent from the evidence that Dr Ackland and Dr John considered the concept to be inventive.
Dr John explained the inventive concept of the E-Chem patent in oral evidence in a consistent manner. He said:
…the inventive concept is not the fact that you could apply a DC – an external DC supply to get more current out of the anode. It is - the fact is that you… need to get the extra current in the initial stage to achieve the effect you need of significantly reducing the overall corrosivity of the environment or suppressing the corrosion so that the second stage, when you are now solely reliant on galvanic anodes, that they are able to operate successfully. It’s not the – the issue is the combination of those two features, not the fact that those two features can exist in isolation.
Vector’s two “preliminary observations” about the inventive concept require caution. Vector submitted that:
(a)the invention as described, and as claimed, … is not limited to any specific current density levels at the steel – instead it expressly teaches that the required improvement in the environmental conditions around the steel can be achieved using a wide range of current densities; and
(b)similarly, the invention is not prescriptive as to how the end of the first phase is to be identified. The specification proceeds on the basis that a sufficient degree of improvement in the environment around the steel would involve practising the invention.
The required caution is that the issue is the identification of the inventive concept (not the invention as claimed). Current densities at the steel are crucial to the inventive concept. In the first phase the current density is to be high and over a short period “to rapidly arrest corrosion minimising further damage” and in the second phase the current density is to be low and long-term to “sustain passivity and ensure durability”.
As such, it is inaccurate to say, as Vector does, that the E-Chem patent expressly teaches that the required improvement in the environmental conditions around the steel can be achieved using a wide range of current densities. To the contrary, the E-Chem patent teaches that the low current densities used in existing long-term cathodic protection systems enable corrosion-induced damage to continue until the corrosion process is ultimately arrested, while the high current densities used in temporary treatment methods (chloride extraction and realkalisation) rapidly arrest the corrosion process. The inventive concept includes combining aspects of the existing treatment systems using a single anode which functions as both a high current density inert anode (sourced by an external DC power supply) to rapidly arrest corrosion and then a low current density galvanic sacrificial anode to achieve long-term durability of the protective effects with minimal maintenance requirements.
It is fundamental to this inventive concept that the anode be capable of delivering both high current densities temporarily when in impressed current mode and low current densities when in sacrificial anode mode. While these high and low current densities are not prescribed in the claims, the specification discloses that: (a) the high impressed current density is to be sufficient to arrest corrosion, but this can be substantially less intensive than the very intense temporary electrochemical treatments applied in chloride extraction and realkalisation, (b) average current applied during the initial impressed current electrochemical treatment will typically be at least an order of magnitude greater than the average current subsequently applied during the low current preventative treatment, and (c) the low current preventative treatment will usually involve the delivery of an average current density of less than 5 mA/m2 and more than 0.2 mA/m2 to the steel surface.
Given this, I do not accept that the E-Chem patent teaches that the required improvement in the environmental conditions around the steel can be achieved using a wide range of current densities.
I accept that the E-Chem patent does not prescribe how the end of the first phase of treatment is to be identified. This said, the patent does explain that: (a) the first phase is temporary and intended to be “brief” and the second phase is ongoing for the lifetime of the structure, and (b) electrochemical treatment in the first temporary phase may be applied for less than three months and preferably less than three weeks.
While the claims are relevant to identifying the inventive concept, it is the heart of the invention which is the required focus, not the specific limits on the scope of the invention as claimed. On this basis, it would be to denude the inventive concept of its essential content not to accept that it involves a short high impressed current phase for one purpose (to rapidly arrest corrosion) and a permanent low (relative to the first phase) galvanic current phase for another purpose (to continue steel passivity) using the same anode. Further, these requirements are informed by the information in the E-Chem patent about the current densities in each phase by reference to details of existing techniques, up to date analysis, and the common general knowledge of the person skilled in the art about these matters.
For these reasons Vector’s submission that nothing in the specification suggests that the “high current” density used for the initial phase must be at some minimum level is inapt. It is apparent that the inventive concept includes that in the first phase the high current density is to be: (a) high relative to the second phase (not merely higher than the density in the second phase by any amount), (b) typically at least an order of magnitude greater than the average current applied in the second phase, and (c) the low current in the second phase is usually less than 5 mA/m2 and more than 0.2 mA/m2. Moreover, these requirements are informed by the fact that the current in the first phase is impressed from an external power source and the current in the second phase is galvanic and generated by the sacrificial anode. This is in a context where the essence of the invention also includes that a sacrificial anode can be used to provide both a high current density temporarily and a low current density thereafter for the life of the structure.
Further, Vector’s focus on phrases in the specification out of context is unhelpful. The “relatively small amount of charge’” in paragraph 14 of the specification is in the context of describing the restoration of alkalinity at corroding sites. The theory underlying the inventive concept is the recognition that if, as posited in the specification, the dominant protective effect is achieved by an increase in pH at the steel/concrete interface, then the temporary impressed current first phase to arrest corrosion can involve substantially less current density than the very intense temporary electrochemical treatments (that is, in chloride extraction and realkalisation). These current densities for chloride extraction and realkalisation, however, would be understood by the person skilled in the art to be many orders of magnitude greater than those used in cathodic prevention techniques (“hundreds or even thousands of [mA/m2]” as Dr Ackland said). The fact that the current density in the first phase may be substantially less than these current densities for chloride extraction and realkalisation does not mean that the current densities in the first phase are not “high”.
The inventive concept of the Fosroc 2004 application was not that the increased current density resulting from the assembly could “achieve a substantial improvement in the environment around the steel, including so as to passivate the steel, within a reasonable time frame”. While the Fosroc 2004 application refers to a sacrificial anode for “cathodically protecting and/or passivating a metal section” and that the high initial current is useful as “it allows the assembly to be used to passivate metals” it does not refer to improving the environment around the steel. Nor does it refer to any experiment in which steel corrosion was passivated in 47 days. This is a reference to experiments undertaken by Dr Glass and others at Fosroc in October 2003 using the prototype sacrificial anode assembly Dr Glass had built in March 2003 which showed that the galvanic protection supplied by the prototype sacrificial anode, under the test conditions, achieved passivation of the steel after 47 days. Any suggestion that Dr Glass withheld this information from Barker Brettell is untenable.
It was common general knowledge that a better sacrificial anode would be one that provided a greater current in the conventional range for cathodic protection for a longer period whilst retaining the advantages of sacrificial anodes, including the fact they were embedded in concrete and required no maintenance or monitoring. Dr Glass’s inventive concept from March 2003 and as the subject of the Fosroc 2004 application provided a greater current in the conventional range for cathodic protection whilst retaining these advantages of sacrificial anodes. It did so as a result of its integrated assembly of a single cell with the sacrificial anode. The reduction of this inventive concept to practice subsequently showed that the assembly could passivate steel within a period of 47 days.
In response to proposition (c), it was not part of Dr Glass’s inventive concept from March 2003 or as the subject of the Fosroc 2004 application that “the embedded galvanic anode could have an ongoing galvanic-only operation if the anode were connected to the steel following a period during which the higher current density was delivered, and recognising that the rate of corrosion had been slowed, meaning that the steel required lower current density levels to protect it”. This is inaccurate in numerous respects. Specifically:
(1)at no time did any of the inventors of the Fosroc 2004 application, Dr Glass, Dr Davison or Mr Roberts, recognise that “the embedded galvanic anode could have an ongoing galvanic-only operation if the anode were connected to the steel following a period during which the higher current density was delivered”. To the contrary, they considered that the anode would operate conventionally – with a higher initial current, reducing over time as the galvanic material became depleted. Once all of the galvanic material in the cell had been consumed, the anode would stop operating as it was connected to the steel via the cell;
(2)at no time did any of the inventors of the Fosroc 2004 application, Dr Glass, Dr Davison or Mr Roberts, consider that the anode could be connected to the steel by some method other than the isolated cell – it was that connection which gave the advantage of the greater current;
(3)at no time did any of the inventors of the Fosroc 2004 application, Dr Glass, Dr Davison or Mr Roberts, consider that the integrated assembly had anything other than a galvanic operation for the life of the assembly;
(4)at no time did any of the inventors of the Fosroc 2004 application, Dr Glass, Dr Davison or Mr Roberts, consider that the integrated assembly would provide one kind of non-galvanic operation while the assembly produced a higher current followed by a lower current density galvanic current. The invention was a new assembly for a sacrificial anode which would operate in one mode only, galvanically, in a conventional manner, which involves a higher initial current reducing over time until the cell is depleted. The advantage of the assembly was that the current density would be relatively higher compared to other sacrificial anodes, not that the current density would be high initially due to the cell and then reduce to a low galvanic current when the cell was depleted;
(5)at no time did any of the inventors of the Fosroc 2004 application, Dr Glass, Dr Davison or Mr Roberts, consider that the integrated assembly would deliver a high current density to slow the rate of corrosion at the steel followed by delivery of a lower density galvanic current to continue to protect the steel;
(6)the Fosroc 2004 application contained a statement that the assembly produces a high initial current which is useful as it allows the assembly to be used to passivate metals. The application does not suggest that this passivation is achieved by the high initial current on its own. It is produced by the operation of the assembly. This statement was inserted by Mr Viles who was not an inventor of the invention; and
(7)the Fosroc 2004 application contained a statement that “[w]hen the cell of the assembly of the present invention ultimately becomes depleted, the sacrificial element may still remain active and thus continue to provide cathodic protection”. This statement, in terms, is mere speculation. The inventors, as at the date of the Fosroc 2004 application and today, consider the statement is incorrect. The expert evidence supports the conclusion the statement was and is incorrect. The statement was inserted by Mr Viles who was not an inventor of the invention.
It is apparent that Vector’s submissions are infused with hindsight in respect of the inventive concept of the Fosroc 2004 application. The submissions anachronistically suggest that it was part of the inventive concept of the Fosroc 2004 application, as conceived by Mr Viles at least, that:
(1)a separate temporary source of DC power could be embedded with a sacrificial anode in concrete. In fact, the assembly consisted of an integrated unit;
(2)the source of DC power was to be in series. In fact, the integrated unit consisted of a single cell (a battery) which formed part of the one unit with the sacrificial anode;
(3)the separate source of DC power provided an increased current density at the steel compared to the current density produced by the sacrificial anode. In fact, the current density which the integrated assembly produced was always the result of the operation of the sacrificial anode connected to the steel via the single cell;
(4)the separate source of DC power provided an increased current density at the steel so as to passivate the steel. In fact, the increased current density was the result of the operation of the assembly as a whole integrated unit and was not the result of the operation of the DC power source. That increased density output of the whole integrated unit could operate to passivate the steel; and
(5)after the separate source of DC power was consumed, the sacrificial anode could continue operating galvanically at a lower current density to continue to protect the steel. In fact, once the galvanic operation of the single cell ceased, there was no means proposed to connect the sacrificial anode to the steel by some other method (that is, other than via the cell) and the integrated assembly would cease working.
As I have said I consider Mr Viles’s evidence, used by Vector to support these propositions, does not do so when properly understood in context and/or, to the extent it does do so, reflects the effect of hindsight on Mr Viles from the time he became aware of the inventive concept of the E-Chem patent family and decided that Fosroc may be able to formulate a case to amend the Fosroc 2004 application to achieve novelty defeating priority over the E-Chem patent family. This effect of hindsight on Mr Viles’s evidence is impermissible but unsurprising. Mr Viles had a responsibility to expand Fosroc’s intellectual property claims to the extent legitimately arguable. Mr Viles understood how patent processes could be used to obtain commercial advantages. Mr Viles recognised the commercial value of the E-Chem hybrid process invention and the related patents. Mr Viles wanted Fosroc to explore every avenue to see if Fosroc could obtain a commercial benefit from the E-Chem hybrid process invention. Having worked on this basis between 2004 and 2009, when the Fosroc business was sold to Vector, Mr Viles was not in a position to strip hindsight from the evidence he gave by affidavit in this proceeding.
Vector submitted that Dr Ackland and Dr John “agreed that what was missing from Fosroc 2004 was information that was in the Viles emails (which they had not seen)”. This is incorrect. It is an inference illegitimately drawn by Vector from evidence of Dr Ackland and Dr John. The proposition, in these terms, was never put to Dr Ackland or Dr John. Their evidence cannot be understood as involving any agreement that “what was missing from Fosroc 2004 was information that was in the Viles emails”. In particular, it is clear that Dr Ackland and Dr John recognised the inventive concept of the E-Chem patent to be or include the hybrid two stage process involving the single anode which formed no part of the inventive concept of the Fosroc 2004 application. They also plainly did not agree that the inventive concept of the Fosroc 2004 application included an external power source or the application of impressed current to the sacrificial anode or any connection between the sacrificial anode and the metal other than via the isolated cell which together with the sacrificial anode formed part of the integrated assembly of the inventive concept of the Fosroc 2004 application.
Vector submitted that:
Even the embodiment that is directly described in the 2003 Fosroc Application of a battery anode assembly being encased in concrete with no gizmo is closely related to a two-phase use of the zinc anode, because the voltage supplied by the battery reduces over time, and approaches the voltage that would be supplied by the galvanic anode alone (at least until the battery is depleted). So there is an initial period of operation with substantially increased current density being delivered to the steel, followed by a period of operation during which the current density approaches one that is closer to that attributable to the galvanic potential only.
This is incorrect. As discussed, the Fosroc 2004 application (including all of its earlier manifestations) involves an integrated sacrificial anode assembly which operates in one mode only, galvanically. The single cell operates galvanically connecting the sacrificial anode to the steel, with the combined operation involving a conventional galvanic output of current density (albeit at a higher current density of other sacrificial anodes) which is higher initially and reduces over time as the electrode material in the battery is consumed. There is no “initial period of operation with substantially increased current density being delivered to the steel, followed by a period of operation during which the current density approaches one that is closer to that attributable to the galvanic potential only”. There is one assembly which operates in one manner, galvanically, starting out producing a higher current density and reducing over time as the battery is depleted. Further, and contrary to Vector’s submissions, there is no “later phase [in the Fosroc 2004 application] ... functionally close to the galvanic-only phase in the E-Chem Patent”. There is one galvanic phase only in which the integrated assembly in the Fosroc 2004 application operates which, as with all sacrificial anodes, produces reducing current density over time.
For these reasons I do not accept that the inventive concept of the E-Chem patent was conceived of by Dr Glass, Dr Davison and Mr Roberts while they worked at, or in the course of their employment, at Fosroc. Nor do I accept that “key developments” conceived of by Dr Glass, Dr Davison and Mr Roberts while they worked at Fosroc make Vector an “eligible person” together with E-Chem in respect of the E-Chem patent. No part of the inventive concept of the E-Chem patent was conceived of by Dr Glass, Dr Davison and Mr Roberts while they worked at Fosroc. In answer to Vector’s specific submissions in this regard:
(1)Vector’s reference to “the concept of applying DC power to an embedded sacrificial anode” involves a mistaken focus redolent of hindsight. What Dr Glass conceived of at Fosroc, culminating in the Fosroc 2004 application, was not applying DC power to an embedded sacrificial anode, but was a specific assembly for a sacrificial anode involving a single isolated cell;
(2)Vector’s reference to “the concept of using the embedded sacrificial anode for a longer-term low-current treatment whether by reason of the proposal by Mr Viles around the temporary connection, or the same conception via the description of the ‘gizmo’” involves a mistaken focus redolent of hindsight. All sacrificial anodes involve long-term treatment. All sacrificial anodes produce a reduced current density over time. All sacrificial anodes involve cathodic protection which is a low density current treatment;
(3)Vector’s submission that the battery anode without a “gizmo” operating longer term approached a galvanic-only operation is misconceived. The Fosroc 2004 application did not include any form of “gizmo” as part of its inventive concept. The sacrificial anode of the Fosroc 2004 application only operated galvanically; and
(4)Vector’s reference to “the concept of achieving substantial improvement of the environment around the steel by using an enhanced sacrificial anode, to which DC power was connected in series” is wrong. There was no such concept at Fosroc. The enhancement of the sacrificial anode was the fact it was integrated into a unit with a single cell. There was no “enhanced sacrificial anode, to which DC power was connected” (emphasis added). Nor was the single cell connected in series to the enhanced sacrificial anode.
No material contribution to the inventive concept of the E-Chem patent occurred while Dr Glass, Dr Davison or Mr Roberts worked at Fosroc. Mr Viles did not make any material contribution to the E-Chem patent or, indeed, to the inventive concept culminating in the Fosroc 2004 application.
It is not necessary to dwell on E-Chem’s submission that the fact that three people, Mr Simpson, Mr Wayne Zakers and Dr Sergi, were employed by Fosroc, involved in relevant events and two of whom remain employed by Vector but were not called to give evidence, should lead to an inference that their evidence would not have assisted Vector. Suffice to say that all three were involved in relevant events at Fosroc. All three provided affidavits. Vector decided not to rely on their affidavits. That was a forensic decision Vector was entitled to make. To the extent that Mr Simpson, Mr Zakers and Dr Sergi could have given relevant evidence (which is unclear) it may be inferred that their evidence would not have assisted Vector. But that conclusion remains at an unhelpful level of generality as it is not apparent what relevant evidence they could have given which would have been material to any conclusion I have drawn.
More important is the fact that while Mr Viles’s affidavits are admissible and not excluded by the hearsay rule by operation of s 63 of the Evidence Act 1995 (Cth) this does not mean that his affidavits must be accepted at face value. They are statements made in 2019 and 2020 about events in 2003–2007, for the most part. As noted, unlike Dr Glass, Dr Davison and Mr Roberts, Mr Viles had no cause to think about these events after January 2009 and the sale of the Fosroc business to Vector. At the time, Mr Viles had a vested interest in taking an expansive view of Fosroc’s patent rights. It may be inferred that this expansive view has coloured Mr Viles’s perceptions both at the time and thereafter. The contemporaneous documents provide the best guide to the weighing of the evidence including that of Mr Viles, Dr Glass, Dr Davison and Mr Roberts. Those contemporaneous documents invariably support the evidence of Dr Glass, Dr Davison and Mr Roberts.
8. The assignment issue
Given the conclusions above, the assignment issue does not arise.
I will confine myself to the following observations.
But for the subsequent addenda executed in 2019 the deed of assignment dated 29 January 2009 is immaterial because the assignment is of all rights attaching to the “Patents” which are listed in a schedule. The schedule does not include any patent within the E-Chem hybrid process patent family.
Fosroc and Vector also executed a sale and purchase agreement on 29 January 2009. The Purchased Assets are defined to mean “all of the assets and property … owned and used by the Sellers or held by the Sellers for use in, or in respect of the operation of the Business by the Sellers including, without limitation, the following…”: cl 1.1. The “Sellers” are defined to include Fosroc International Ltd, the employer of Dr Glass, Dr Davison and Mr Roberts: cl 1.1. The “business” is defined to mean “the research, development … of electrochemical corrosion mitigation products, services and systems, including the … but excluding the Excluded Business”: cl 1.1. While cl 3.1 provides that the Purchase Price shall be payable to the Sellers for the Purchased Assets, the operative provision, cl 2.1 does not refer to the Purchased Assets. Instead cl 2.1 refers to other defined assets which are themselves defined by reference to assets listed in various parts of sch 1 to the agreement. To take the “FIL Assets” as an example, that term is defined to mean “the assets listed in part 2 (paragraph 1) of schedule 1”. That part of sch 1 includes reference to various versions of the Fosroc 2004 application patent family but not the E-Chem patent.
As noted, the operative answer to Vector’s claim is that Fosroc had no entitlement of any kind (sole or joint) to the E-Chem patent and thus could not purport to sell any such rights to Vector. E-Chem’s alternative argument is that Vector could not have purchased any rights in the E-Chem patent from Fosroc under the agreement because the E-Chem patent or rights in respect of it were not “used by the Sellers or held by the Sellers for use in, or in respect of the operation of the Business by the Sellers” as required by the definition of Purchased Assets. E-Chem observed in support that it is apparent that Fosroc did not consider that it owned any entitlement to the E-Chem patent, and consequently it did not make any use of such a right as part of the operation of its Business, or hold it for that purpose. This is supported by the fact that the agreement incorporates the Warranties in sch 3 (see cl 5) which refers to a disclosure letter dated 29 January 2009. The disclosure letter refers to the E-Chem hybrid process patent PCT application number WO2006/097770 and records that it is arguable that Fosroc’s pending PCT application PCT/GB2005/001651 (a version of the Fosroc 2004 application) anticipates all of the claims of the E-Chem hybrid process patent. In other words, the common contractual intention of Fosroc and Vector was not that Fosroc had any entitlement to the E-Chem hybrid process patent, but that it might have an argument to priority.
This submission of E-Chem must be correct. Under the agreement, rights in respect of the E-Chem patent do not form part of the FIL Assets or the Purchased Assets. If Fosroc held any rights to the E-Chem hybrid process patent it did not transfer those rights to Vector by the agreement. Rather, it transferred to Vector the Fosroc 2004 application patent family and that transfer necessarily carried with it whatever rights Fosroc had to claim priority over the E-Chem hybrid process patent and thereby defeat the novelty of that patent.
There is no need to deal with the addendum dated 9 July 2019 as a further addendum dated 16 September 2019 was executed in additional terms. By the operative provision, cl 2, Fosroc assigned to Vector “all rights, title and interest to all inventions and improvements and other technologies owned by the Assignor in connection with the Purchased Assets, including … the rights to pursue, obtain and/or claim entitlement from relevant governmental authorities to patents, designs or other similar industrial property rights” but cl 2(a)(iii) provided that cl 2 does not extend to “any inventions and improvements and other technologies created after the date of the Original Agreement”. The Original Agreement is the sale and purchase agreement dated 29 January 2009.
As E-Chem submitted the problems are that: (a) the assigned rights are only in connection with the Purchased Assets which, given the definition of that term, cannot include any rights in the E-Chem hybrid process patent, and (b) to the extent that the Purchased Assets include the FIL Assets which includes the Fosroc 2004 application, there is no right in connection with that patent family which involves a right to claim entitlement to (as opposed to priority over) the E-Chem hybrid process patent.
In short, any rights that Fosroc had to entitlement to the E-Chem hybrid process patent would be derived from the employment relationship between Fosroc and Dr Glass, Dr Davison and Mr Roberts and the consequential operation of s 39 of the Patents Act 1977 (UK). Section 39 is to the effect that “an invention made by an employee shall, as between him and his employer, be taken to belong to his employer for the purposes of this Act and all other purposes if”, amongst other things, the invention was made in the course of the normal duties of the employee or, if outside that scope, in the course of duties specifically assigned to the employee and “the circumstances in either case were such that an invention might reasonably be expected to result from the carrying out of his duties”.
The rights which could have arisen in Fosroc by reason of the employment relationship and under s 39 (if, contrary to my conclusions, Dr Glass, Dr Davison and Mr Roberts conceived of the inventive concept while employed by Fosroc) are not “in connection with the Purchased Assets” or “in connection with the FIL assets” as provided for in the contracts.
It is not necessary to refer to any pre-contractual communications between Vector and Fosroc about the addenda to conclude that the addenda do not transfer to Vector any of Fosroc’s rights arising from Fosroc’s employment of Dr Glass, Dr Davison and Mr Roberts and the making of the invention the subject of the E-Chem patent in the course of their duties as employees of Fosroc.
It follows that if my principal conclusions are incorrect and Fosroc had some right to the invention the subject of the E-Chem patent by operation of s 39 of the Patents Act 1977 (UK), then Vector did not obtain any such rights by its contracts with Fosroc.
9. The discretion issue
Given the conclusions above, the discretion issue does not arise.
I will confine myself to the following observations.
E-Chem submitted that if Vector had any entitlement to the E-Chem patent I should decline to make any order under ss 34(1) and 192(2) of the Patents Act in Vector’s favour in the exercise of discretion given: (a) Vector’s inordinate and unjustified delay in bringing its entitlement claim between 2009 and 2019, (b) the exacerbation of the delay by Vector threatening claims of infringement against E-Chem based on amended claims of the Fosroc 2004 application patent later the subject of consent orders revoking the amended claims, (c) prejudice to the respondents caused by the delay given the substantial investments made by them in the business in Australia over the years, and (d) the unfair advantage Vector would obtain “being future license fees from a fully established Australian business, and a business established at the Respondents’ expense” rather than at the expense of Vector.
Vector submitted that ss 34(1) and 192 of the Patents Act do not vest any discretion in the Court. Rather, the references in ss 34(1) and 192(2)(b) to “may” (in s 34(1) that the Court “may, by order, declare that the persons who it is satisfied are eligible persons are eligible persons in relation to that invention so far as so claimed” and in s 192(2) that the Court “may… make any order it thinks fit for the rectification of the Register”) are facultative only and operate to permit the making of an order if the pre-conditions to doing so are satisfied.
The issue about the meaning of “may” in ss 34(1) and 192(2) of the Patents Act is important. I prefer not to express a concluded view about the issue in circumstances where, on my reasoning, it is hypothetical. If those sections vest a discretion in the Court then I would accept that the considerations on which E-Chem relied against the exercise of the discretion would be relevant to the decision whether or not to make an order. I would also conclude that the essence of E-Chem’s complaints of unreasonable delay by Vector in bringing its claims for entitlement to the E-Chem patent and resulting serious prejudice to E-Chem are substantiated on the evidence.
Mr Whitmore gave evidence. As noted, he is the President of Vector. He is an engineer and a certified cathodic protection specialist. It is sufficient to say that it is clear from Mr Whitmore’s evidence as a whole that he is a sophisticated businessperson with a clear understanding of how patent rights can operate to Vector’s advantage. It is obvious from the whole of the evidence that Mr Whitmore well understood from the time Vector purchased Fosroc in 2009 that as a result Vector might be able to amend the Fosroc 2004 application patents to try to obtain novelty defeating priority over the E-Chem hybrid process patents (and, indeed, Vector did so from October 2009 onwards). Even giving Mr Whitmore the benefit of the doubt, he was aware of sufficient information to decide whether or not Vector should claim entitlement to the E-Chem hybrid process patents from no later than 2011. The inference which must be drawn is that Vector did not do so for so long as Mr Whitmore held out hope that the ongoing disputes between Vector and E-Chem about amended claims and priority might yield a commercial solution acceptable to Vector. When that commercial solution did not emerge, Mr Whitmore decided to make the entitlement claim. To the extent Mr Whitmore’s evidence and Vector’s submissions propose to the contrary, I reject both the evidence and the submissions.
I also reject Vector’s submission that Vector “originally prosecuted an entitlement to what was covered by the E-Chem Patent through its patent claim amendments and infringement allegations and then infringement proceeding”. As noted, there are material differences between attempting to obtain novelty defeating priority by amending the claims of a patent and asserting entitlement to the patent over which priority is sought.
Mr Whitmore said that although he had copies of the emails from Mr Viles to Barker Brettell of 3 and 26 January 2007 as part of the sale and purchase negotiations with Fosroc he did not then consider from the emails that “any of the individual respondents had wrongfully taken inventions they had made whilst at Fosroc, or information and records owned by Fosroc, and filed various patent applications in their own names and the names of others for their own benefit”. He also said that while cl 1.2(3) of the disclosure letter referred to in the sale and purchase agreement said that Fosroc “has not, so far, sought to comment or contest the Employee’s application W02006/97770 but has sought legal advice on the matter” he did not see any such advice.
Further, Mr Whitmore said that he first considered the issue of the position “when ex-employees subsequently filed a patent application in respect of inventions made as a result of work conducted on behalf of the employer before departure (i.e. the Fosroc 2004 Application and any other research work conducted at Fosroc)” in 2011 after he learned that Dr Glass, Dr Davison and Mr Roberts had filed the patent application in the US claiming priority from the Fosroc 2004 application. Mr Whitmore emailed Mr Zakers at Fosroc for information (including the employment contracts of Dr Glass, Dr Davison and Mr Roberts) and Mr Zakers said in response on 1 July 2011:
Of course if a new patent is filed in the UK after the employee’s departure date then that patent is owned by the inventor. There would be some argument if it could be shown that the patent included work that was conducted on behalf of the employer before departure… In respect of the High Voltage Anode patent, we did not file a new patent to clarify the point about having considered an external power source (and therefore creating prior art in respect of the Davison, Glass, Roberts Duoguard), we submitted an amendment to the original claim to clarify this.
Mr Whitmore’s oral evidence, however, was that he did not know in 2011 about the “Viles emails” (that is, the emails involving Mr Viles and Dr Glass of 7 and 8 April 2003), as if these emails were of significance to his decision to cause Vector to bring this proceeding.
But as E-Chem observed, when Vector first asserted an entitlement to the E-Chem patent on 17 January 2019 it made no reference to the Viles emails and instead referred to information Vector had in its possession since it purchased Fosroc in 2009. Further, Vector did not rely on the Viles emails as part of its entitlement claim until it filed its second further amended statement of claim. Knowledge of the Viles emails was not necessary to enable Vector to bring an entitlement claim if it wished to do so at any time from 2009 or 2011 when it had possession of the contracts of employment of Dr Glass, Dr Davison and Mr Roberts. The necessary inference is that Vector did not do so at that time because it assessed that it was not in its overall commercial interests to do so.
If ss 34(1) and 192(2) of the Patents Act provide the Court with a discretion then I would have exercised the discretion against Vector and declined to make any order. Vector’s delay in bringing its claims has been extreme and unreasonable. In seeking to obtain the most commercial advantage it could between 2009 (or, at the latest, 2011) as against E-Chem Vector sat on its hands in respect of its entitlement claim for 10 (or 8) years while the respondents invested an enormous amount of time, money and effort in developing and commercialising the E-Chem hybrid process invention including in Australia. By its unreasonable and inordinate delay Vector would obtain a substantial and unjustified windfall benefiting from the time, money and effort of the respondents (at no charge to Vector). The resulting prejudice to the respondents borders on the incalculable. It is 10 (or 8) years of their working lives. Not only would they lose (or have to share, if joint entitlement was found) the fruits of their time, money and effort over that entire period, but they would also bear the lost opportunity burden. They could have been focusing on other inventions and commercial opportunities to their benefit during those 8 or 10 years but did not do so as no-one had ever asserted entitlement to the E-Chem hybrid process patents before. Dealing with amended claims as part of a battle for priority is one thing. Dealing with a claim for entitlement is another. Dr Glass’s evidence to the effect that he was annoyed and distressed by the priority/infringement battles with Fosroc and Vector but “absolutely surprised” by the entitlement claim when it was ultimately brought is readily understandable.
The only considerations put against such an exercise of discretion (assuming it exists) related to the “public interest in the integrity of the Register, as well as in patent rights not being held by a person who is not entitled to them”. The public interest in the integrity of the Register is underpinned by the need for certainty and transparency about patent entitlement. That interest would not be undermined by rejecting Vector’s claims to entitlement on a discretionary basis if such a discretion exists. Nor would any public interest consideration be undermined. There is an equal if not more important public interest in ensuring that people in Vector’s position do not unreasonably delay the commencement of entitlement proceedings to the serious prejudice of those whose entitlement has otherwise been registered.
10. Conclusions
For these reasons, Vector’s claim must fail in its entirety. Vector is not an “eligible person” in respect of the E-Chem patent either solely, or in the alternative, together with E-Chem. Vector could not have acquired from Fosroc any rights in respect of the E-Chem patent as Fosroc possessed no such rights at any time. There is also no basis upon which the E-Chem patent would be revoked.
Orders will be made accordingly. Directions will be made in relation to the issue of costs to enable any claim for indemnity costs, as foreshadowed by E-Chem, to be made.
I certify that the preceding three hundred and eighty-eight (388) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Justice Jagot. Associate:
Dated: 9 March 2022
SCHEDULE OF PARTIES
QUD 117 of 2019 Respondents
Fourth Respondent:
GARETH KEVIN GLASS
Fifth Respondent:
VECTOR CORROSION HOLDINGS LTD
Sixth Respondent:
VECTOR MANAGEMENT LTD
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