Borden Inc v Elkem A/S

[1995] APO 11

official notice

decision of a delegate of the commissioner of patents

Application        :    No.615288 in the name of BORDEN INC.

Title:    Manufacture of a Soderberg Electrode Incorporating a High Carbon-Contributing Phenolic Sacrificial Binder

Action: Opposition under Section 59 (Patents Act 1952) by ELKEM A/S

Decision:    Issued            .

Abstract:    Novelty and obviousness considered.

Grounds of opposition not established.

Opposition dismissed.

patents act 1990

decision of a delegate of the commissioner of patents

Re:Patent Application No. 615288 by BORDEN INC. and opposition thereto under Section 59 of the Patents Act 1952 by ELKEM A/S.

background

Patent Application No 615288 by BORDEN INC. (BORDEN) was lodged on 17 April 1989 as a convention application based on a U.S. basic application 252122 filed in the U.S. on 3 October 1988.

Acceptance of the application was advertised on 26 September 1991. ELKEM A/S (ELKEM) filed a notice of opposition on 19 December 1991 and served a statement of grounds and particulars on 10 January 1992. Evidence-in-Support was completed on 23 October 1992, Evidence-in-Answer on 2 March 1993 and Evidence-in-Reply on 31 May 1993.

The opposition came to hearing in Canberra on 19 September 1994. Mrs. A. Bennett of Counsel and Mr. John O'Connor, Patent attorney of Spruson & Ferguson, Sydney represented the applicant. Mr. Alun W. Thomas, Patent attorney of Collison & Co., Adelaide represented the opponent.

As the application was lodged prior to but advertised accepted after commencement of the Patents Act 1990, the opposition is in substance determined, in accordance with the provisions of section 234(3) of the 1990 Act, under Part V of the Patents Act 1952 but with the procedures of the opposition governed by Chapter 5 of the Patents Regulations 1991.

The grounds of opposition were based on non-compliance with paragraphs 18(1), (b), (i) and (ii) of the 1990 Act, which relate to novelty and obviousness.

SPECIFICATION

The specification commences by stating that:

"This invention relates to a novel composition for use in the manufacture of a Soderberg electrode and to the improved electrode produced thereby. This composition includes a high carbon-contributing phenolic sacrificial binder."

It then sets out the background of the invention as follows:

"The Soderberg process produces a self-baking electrode that is formed continuously from a soft carbon mixture that is baked in the same furnace in which it is used. The Soderberg process is continuous, involving the addition of a paste to the upper end of the electrode-manufacturing apparatus. This paste is a mixture of a carbonaceous aggregate and a pitch binder. The paste has sufficient mobility to travel through the temperature gradient. The temperature increases as the paste approaches the electrolyte cell area. During this travel, the paste typically begins to harden into something akin to a jelly formation with loss of volatiles - the paste retaining thermoplasticity while not being too fluid to cause excessive overflow of the paste. The moving paste then approaches the use zone where it hardens and attains electrode integrity through densification and binder graphitization upon exposure to the operating temperatures of the electrolytic cell. In the cell the electrode is not only used but is continually consumed."

It identifies the defects of the prior art as arising from the exclusive use of pitch binder. It states:

"Such a high pitch content leads to extensive fume evolution and to a loss of volatiles, which in turn lead to electrodes having poor integrity. Additionally, coal tar pitch has been under heavy environmental pressures  and scrutiny for carcinogenicity attributed to volatile components such as "pyrene." "

Further on the description gives a summary of the invention, detailing five different embodiments which are essentially the same as the five independent claims. This is followed by a detailed description of the invention including examples. The specification ends with fifty-five claims of which the five independent claims read as follows:

1. A feedstock composition for the production of a Soderberg continuous carbon electrode wherein said composition has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed and wherein said moving viscous bed of heated composition enters the use zone of said Soderberg electrode as a paste, hardens, and attains electrode integrity, comprising

a mixture of particulate carbonaceous aggregate, phenolic resin binder, plasticizer having a boiling point of at least about 200oC in an amount of 0-50% based on the combined weight of resin solids and plasticizer and from 0% to no more than 5% hexamethylenetetramine based on phenolic resin solids,

said phenolic resin binder comprising phenolic novolac resin characterized by a minimum melt point of 100oC and a free phenol content of not more than 4% by weight as measured by gas chromatography analysis.

13.A feedstock composition for the production of a Soderberg continuous carbon electrode wherein said composition has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed and wherein said viscous bed enters the use zone of said Soderberg electrode, hardens and attains electrode integrity comprising:

resin coated carbonaceous aggregate, plasticizer having a boiling point of at least 200oC in an amount of 0-50% based on the total weight of resin solids and plasticizer, and from 0% to no more than 5% hexamethylenetetramine based on resin solids,

said resin coated carbonaceous aggregate being formed from a mixture comprising phenolic novolac resin and particulate carbonaceous aggregate.

18.A process for making a feedstock composition for a Soderberg continuous carbon electrode prepared from a particulate carbonaceous aggregate, a resin binder comprising a phenol formaldehyde novolac resin in particulate or hot melt form, and hexamethylenetetramine, said novolac having a melting point of at least 100oC, a total volatiles content at 135oC and (sic) not more than 5% by weight of said resin solids including a free phenol content of not more than 4% by weight of said resin solids as measured by gas chromatography analysis, comprising:

mixing said particulate aggregate with sufficient resin binder so that the solids of said resin comprise 6%-15% by weight of said aggregate and with 0%-5% by weight of hexamethylenetetramine based on the weight of said phenol formaldehyde novolac to coat said aggregate to produce a free flowing resin-coated aggregate material.

22.A process for making a feedstock composition for the production of a Soderberg continuous carbon electrode wherein said feedstock has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed of heated paste, and to enter the use zone of said Soderberg electrode, wherein said heated moving bed of viscous paste hardens and attains electrode integrity comprising:

mixing particulate carbonaceous aggregate, curable resin binder, plasticizer having a boiling point of at least 200oC in an amount of 0-50% based on the combined weight of resin solids and plasticizer, and from 0% to no more than 5% hexamethylenetetramine based on resin solids, until a free flowing resin-coated aggregate material is formed, wherein said curable resin binder comprises a novolac resin in an amount of from about 5% to about 20% by weight of resin solids based on the weight of said carbonaceous aggregate, said plasticizer and said curing agent if used being present in amounts sufficient to impart sufficient mobility and flowability to said paste as it travels toward said use zone.

39.A process for making a Soderberg electrode comprising the steps of:

(1)passing a feedstock of resin-coated carbonaceous particles through the three Soderberg electrode forming zones wherein in a first zone said feedstock moves downwardly toward a baking zone in the form of discrete, free-flowing particles;

(2)in said baking zone passing said feedstock through a temperature gradient and converting it from discrete free-flowing particles to a bed of viscous paste that moves downwardly toward the electrode-forming and use zone; and

(3)in said electrode-forming and use zone hardening said paste into a continuous electrode shape and then using said shape as a continuously-formed Soderberg electrode;

wherein said feedstock comprises an admixture of resin coated carbonaceous aggregate, plasticizer having a boiling point of at least 200oC in an amount of 0-50% based on the total weight of resin solids and plasticizer, and from 0% to no more than 5% hexamethylenetetramine based on resin solids, said resin coated carbonaceous aggregate comprising a phenolic novolac resin coated on particles of a particulate carbonaceous aggregate."

EVIDENCE

Evidence-in-support consists of a declaration by Morgan Troedsson, Development Manager at Perstorp AB, Sweden, dated 20 October 1992 together with an exhibit MT 1.

Evidence-in-answer consists of a declaration by Pitchaiya Chandramouli, Specialties Marketing Manager of Borden Packaging and Industrial Products, United States of America, dated 25 February 1993 together with exhibits PC-1 to PC-4.

Evidence-in-reply consists of a declaration by Morgan Troedsson dated 27 May 1992(sic).

SUBMISSIONS

Regarding novelty Mr. Thomas made submissions on behalf of the  opponent, which I have summarised as follows:

The claims of the application were directed to a feedstock composition for the production of a Soderberg continuous carbon electrode. Most of the claims detailed the Soderberg process by stating that the composition had sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed, and wherein the moving viscous bed of heated composition entered the use zone of the Soderberg electrode as a paste, hardened and attained electrode integrity. Mr. Thomas stated that the Soderberg process was a well known process and that the claims should be treated as claims to a composition.

Based on the above argument a direct comparison could be made between the composition of the invention and that of the citation.

The invention disclosed four components in its composition:

1. A particulate carbonaceous aggregate,

ii.Phenolic resin binder comprising phenolic novolac resin characterized by a minimum melt point of 100oC and a free phenol content of not more than 4% by weight as measured by gas chromatography analysis,

iii.0% to no more than 5% hexamethylenetetramine(hexa) based on phenolic resin solids,

iv.plasticizer having a boiling point of at least about 200oC in an amount of 0-50% based on the combined weight of resin solids and plasticizer.

The citation disclosed:

1. the use of particulate carbonaceous aggregate,

ii.the use of a phenol-formaldehyde novolac resin with the same     properties as specified in the application,

iii.the use of a curing agent in a sufficient amount to effect curing of said binder under curing conditions. The description has disclosed hexa as a suitable curing agent.

iv.the use of a plasticizer. The description discloses alcohols, glycols and the like as suitable plasticizers. It also discloses ethylene glycol as a suitable plasticizer.

Mr. Thomas submitted with reference to item (iii) above that excluding the value of 0% the use of even a small amount of hexa was a sufficient amount to effect curing of said binder under curing conditions. He also stated that the application disclosed the use of glycols at pages 20, 21 which was covered by item (iv) above. Mr. Thomas then made detailed submissions for each claim of the invention and I will refer to those submissions as and when it is necessary to do so.

Counsel for the applicant Mrs. Bennett made the following submissions with regard to novelty which I have summarised below:

The application disclosed the use of phenolic novolac resin binder on its own. The prior patent disclosed the use of phenolic novolac resin in combination with other resins.

The application is looking at a feedstock composition for the production of a Soderberg continuous carbon electrode whereas the patent is directed to a raw batch composition for use in making a shaped self-sustaining article.

The major difference between the application and the patent is that the composition of the application retains fluidity and mobility throughout the temperature gradient of the Soderberg system whereas the composition of the patent cures at less than 200oC and forms a self-sustaining shaped article and retains this shape at Soderberg temperatures.

The raw batch composition has to have a curing agent in an amount sufficient to effect curing. The composition of the application does not need curing to be effected.

The patent discloses the presence of hexa as a curing agent in an amount of 15-20% & 6-10% by weight based on the weight of the resin and the application discloses the presence of hexa in an amount of 0-5% by weight based on the weight of the resin but without the requirement to effect curing.

On comparing the components of the two compositions:

(a)the particulate carbonaceous aggregate was common to both but it is only one common integer between the different combinations being compared.

(b)the application disclosed a mobile material whereas the patent disclosed a shaped article.

(c)the resin binder of the patent must be curable whereas the resin binder of the application is not curable. The application discloses the use of a resin alone whereas the patent discloses the use of the same resin with resole resin where the resole resin acts as a curing agent.

(d)the resin of the application may be used in the absence of a plasticiser and if plasticiser is used it must have a specified boiling point. The plasticiser of the patent does not specify a minimum boiling point.

Regarding obviousness, Mr. Thomas, attorney for the opponent, did not make any submissions.

Counsel for the applicant, Mrs. Bennett, had at the commencement of the hearing, made submissions regarding admissibility of the opponent's evidence for the purposes of arguing obviousness. She had asked for an immediate ruling in this matter. I shall refer to those submissions in my decision. She did not make any further submissions on obviousness.

DECISION

At the commencement of the hearing counsel for the applicant requested a ruling on the admissibility of certain parts of both declarations of the opponent. The parts related to conclusions on matters of law which is the prerogative of the hearing officer and not of either the applicant or the opponent. Counsel for the applicant read these out for the record. I ruled that those parts of the evidence making conclusions regarding matters of law be struck out.

Counsel for the applicant also submitted that as the declarant for the opponent was not a person skilled in the relevant art in Australia his evidence regarding obviousness could not be considered and that therefore the opponent could not argue obviousness. I did not make an immediate ruling regarding this issue and will address it in my decision on obviousness.

Novelty

The particulars submitted by the opponent state that the invention as claimed in any and all claims is not a patentable invention because it is not novel when compared with Australian Patent Specification No. 592170 published in Australia on 8 October 1987.

Australian patent 592170 (71002/87) describes an improved binder system for making anodes, cathodes and electrodes used in the aluminium and steel industries. The consistory statement discloses:

"...a raw batch composition for use in making a shaped self-sustaining article or for use in monolithic shape construction comprising:

"a mixture of a carbonaceous aggregate, a curable phenol-formaldehyde resin binder in sufficient quantity when cured to bond said aggregate into a desired shaped(sic) that is self-sustaining, and a curing agent in a sufficient amount to effect curing of said binder under curing conditions,

"said binder comprising a phenolic resin that is selected from the group of members consisting of

"(1) a phenol-formaldehyde novolac resin in particulate or hot melt form, having a melting point of at least 100oC (212oF) and a total volatiles content at 135oC (275oF) of not more than 5% by weight of said resin including a free phenol content of not more than 4% by weight of said resin as measured by gas chromatography analysis;

"(2) a mixture of a phenol-formaldehyde novolac resin in particulate or hot melt form, having a melting point of at least 100oC and a total volatiles content at 135oC of not more than 5% by weight of said resin including a free phenol content of not more than 4% by weight of said resin as measured by gas chromatography analysis, and liquid phenol-formaldehyde resole resin, said liquid resole resin having a viscosity in the range from 30cps to 500cps as measured on a Brookfield RVF viscometer at 25oC with a #1 spindle at 20rpm and a free phenol content of not more than 30% by weight; and

"(3) a liquid phenol-formaldehyde resole resin that is free of any added thickening agent, said unthickened liquid resole resin having a viscosity in the range from 50cps to 500cps as measured on a Brookfield RVF viscometer at 25oC with a #1 spindle at 20rpm and a free phenol content of not more than 30% by weight, and

"said resin solids of said binder comprising from 6% to 15% by weight of said aggregate."

The description at page 14, lines 26 to 28 states " The term "self-sustaining" is used to refer to a shape that will retain its dimensions and contours during processing."

Claim 1 is essentially the same as the consistory statement. The appended claims add preferred features, and also claim; a self-sustaining shape, a shaped article, an electrode, a process for making a body that can be pyrolyzed to form an electrode suitable for use in the electrolytic production of metal such as aluminum, a process for making a body that can be pyrolyzed to form a carbonized shape suitable for use in the electrolytic production of metal such as aluminum, and a composition for making a tamping and ramming composition suitable in monolithic shape construction. All the above-mentioned claims, claiming different aspects of the invention, are dependent upon claim 1.

The test for novelty is the "reverse infringement test" as set out by Aickin J. in Meyers Taylor Pty Ltd v. Vicarr Industries Ltd.(1977) 137 CLR 228 at page 235:

"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement."

Regarding infringement Lord Upjohn in Rodi & Wienenberger A.G. v. Henry Showell Ltd. (1969) RPC 367 at p. 391 stated:

"To constitute an infringement the article must take each and every one of the essential integers of the claim. Non-essential integers may be omitted or replaced by mechanical equivalents; there will still be infringement."

Determining the relevance of the opponent's citation is clearly a matter of construction. An alleged citation must:

"be interpreted as at the date of its publication, having regard to the relevant surrounding circumstances which then existed, and without regard to subsequent events. The patentee's claim must similarly be construed as at its own date of publication having regard to the relevant surrounding circumstances then existing. If the earlier publication, so construed, discloses the same device as the device which the patentee by his claim so construed, asserts that he has invented, the patentee's claim has been anticipated but not otherwise."

General Tire & Rubber Co. v. Firestone Tyre & Rubber Co. Ltd. [1972] RPC 457 at 485.

On a fair construction of the citation I consider that the features of the invention which it discloses are the same as set out in the consistory statement bearing in mind that certain limitations are placed on some of the features in light of the disclosure in the description.

On a fair construction of the specification of the applicant I consider that the essential features of the invention reside in:-

a feedstock composition for the production of a Soderberg continuous carbon electrode comprising:

(a)phenolic novolac resin,

(b)particulate carbonaceous aggregate, and

(c)hexamethylenetetramine (hexa) in an amount insufficient to effect curing at temperatures below Soderberg temperatures, i.e. below 500-800oC. This amount lies in the range of 0-5% based on the weight of the resin.

The description also discloses that for the invention to work the phenolic novolac resin must have a high melting point that is 100oC or higher. Also the free phenol (monomer) content of the resins are less than 4% by weight, based on resin solids.

On comparing the invention of the application in claim 1 with the citation I find that there are some differences. These are:

1. Claim 1 is directed to a feedstock composition for the production of a Soderberg continuous carbon electrode whereas the citation is directed to a raw batch composition for use in making a shaped self-sustaining article or for use in monolithic shape construction.

In Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius & Bruning, (1964) AOJP 1483, the delegate concluded that "..a claim to a substance or composition for a particular use should be construed as relating to the substance or composition per se."

I can therefore make a comparison between the two compositions while being mindful of possible restrictions being placed on the components due to the kind of use they will be subjected to.

ii.The citation discloses the feature of a curing agent in a sufficient amount to effect curing of said binder under curing conditions as an essential feature. When the citation uses only phenol-formaldehyde novolac resin, as does the application, it uses hexamethylenetetramine(hexa) as a binder. The description and examples disclose the presence of a minimum value of 6% hexa based on resin weight. The description also discloses that curing of phenol formaldehyde resins occurs in the range 150o to 200oC. Thus the citation discloses hexa in an amount of at least 6% (based on resin weight) as one component of the composition.

Claim 1 of the application does not require curing of the composition to occur and does not disclose a curing range of 150o to 200oC. It discloses the presence of hexa in an amount of 0-5% based on resin weight. To determine if this is an amount sufficient to effect curing in the temperature range of 150-200oC I shall refer to the description. The description at examples 1 and 3 discloses that the composition cures at temperatures below 500oC when the hexa content is above 5% (based on resin weight). The description states that such compositions do not practice the invention as these compositions have not maintained fluidity at Soderberg temperatures. However for the specified phenolic resin when the amount of hexa is 0-5% (based on resin weight) the examples show that the composition retains fluidity at Soderberg temperatures. I therefore conclude, contrary to Mr. Thomas' submissions, that the amount of hexa specified in claim 1 is insufficient to effect curing at 150-200oC.

The citation disclosed a particulate carbonaceous aggregate, a phenolic novolac resin with specified properties and a curing agent in an amount sufficient to effect curing. Claim 1 of the application also disclosed a particulate carbonaceous aggregate and a phenolic novolac resin with similar properties to those of the citation. However the application further disclosed the presence of a curing agent in amounts insufficient to effect curing within temperatures upto 200oC.

As shown above the amount of hexa for the citation falls in the range 6% and above based on resin weight; and for claim 1 of the application falls in the range 0-5% based on resin weight.

Based on this comparison I agree with Mrs. Bennett's submission that the citation has not disclosed each and every one of the essential integers of claim 1 of the invention. As the other independent claims of the application possess similar essential features I consider that the citation has not disclosed each and every one of the essential integers of the other independent claims. The opponent has not proven a lack of novelty of the invention claimed in the claims of the application.

I therefore find that the invention as defined in claims 1 to 55 of the application does not lack novelty.

Inventive Step/Obviousness

The High Court of Australia in the case of Minnesota Mining and Manufacturing Company and Another v. Beiersdorf (Australia) Limited, 144 CLR 253, has required that for obviousness to be proven under the 1952 Patents Act it must be established that the information relied upon had become part of the common general knowledge, at the priority date of the application in suit, of those skilled in the art of the invention under attack.

The test for obviousness is whether the invention claimed would have been obvious to a non-inventive worker in the art who is equipped with the common general knowledge in the art in Australia at the relevant date. The definition of common general knowledge was provided by Aickin J. in the 3M case (supra), at page 292:

"The notion of common general knowledge itself involves the use of that which is known or used by those in the relevant trade. It forms the background knowledge and experience which is available to all in the trade in considering the making of new products, or the making of improvements in old, and it must be treated as being used by an individual as a general body of knowledge."

Regarding obviousness Aickin J. in the 3M case (supra), at page 293 stated:

"It is rather whether it would have been obvious to a non-inventive skilled worker in the field to select from a possibly very large range of publications the particular combination subsequently chosen by the opponent in the glare of hindsight and also whether it would have been obvious to that worker to select the particular combination of integers from those selected publications."

The only materials available to me to assist in deciding the question of obviousness are the declarations by Mr. Troedsson for the opponent and Mr. Chandramouli for the applicant. The declarant for the opponent is a citizen of Sweden. He has not indicated that he has had experience in the art in question in Australia. He has not provided any declaration as to what he considers is the state of the relevant art in Australia and how he may have acquired that knowledge. A similar situation exists with respect to Mr. Chandramouli who is a citizen of the United States of America. I therefore do not have any evidence before me regarding the state of the relevant art in Australia which could assist in determining the obviousness of the applicant's invention.

In conclusion I therefore find that the opponent has not established that the invention under attack is obvious.

CONCLUSION

The opponent has not proven its case against the applicant on the grounds of novelty and obviousness. Accordingly, I dismiss the opposition and, subject to any appeal being filed, direct that the application proceed to sealing.

COSTS

The opponent has failed on both grounds. I therefore award costs against the opponent Elkem A/S.

Jacob Elijah
Delegate of the Commissioner of Patents

Patent attorneys for the applicant  :  Spruson & Ferguson,

Sydney

Patent attorneys for the opponent   :  Collison & Co,

Adelaide