Nippon Steel Corporation v BHP Steel (JLA) Pty Ltd
[2000] APO 62
•10 October 2000
OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Patent : No. 669454 in the name of NIPPON STEEL CORPORATION
TitleThin sheet steel having excellent stretch-flange ability and process for producing the same.
Action : Opposition under Section 59 by BHP STEEL (JLA) PTY LTD.
DecisionIssued .
Abstract
All the claims found to be novel in the light of the documents relied on by the opponent.
In the light of the common general knowledge alone, the opponent was not able to establish that the claims lack an inventive step. Three of the documents sought to be considered with the common general knowledge had not been translated from Japanese as of the priority date. However the hearing officer was prepared to concede that they were documents that would have been ascertained and understood and regarded as relevant, by the skilled addressee in the relevant art in Australia as of the priority date. However none of them were sufficient either alone or combined with the common general knowledge to deprive the claims of an inventive step. One document was not publicly available at the relevant date. The combination of the common general knowledge and the fifth document was not sufficient to find a lack of inventive step.
The specification and claims meet the requirements of section 40. Proposed amendments not yet finalised will not affect the decision.
Opposition fails. Application to be sealed 30 days after the finalising of the proposed amendments unless this decision is appealed.
PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re: Patent No. No. 669454 in the name of Nippon Steel Corporation and opposition thereto by BHP Steel (JLA) Pty Ltd.
BACKGROUND
Patent application No. 669454 in the name of Nippon Steel Corporation [Nippon]
was filed on 24 October 1994 claiming priority from International Patent Application No. PCT/JP94/00699 filed on 26 April 1994 The application was advertised accepted on 6 June 1996. BHP Steel (JLA) Pty Ltd [BHP] filed a notice of opposition on 6 September 1996 to the grant of the patent on the application. BHP subsequently filed a statement of grounds and particulars on 5 December 1996.
The filing of evidence was completed on 29 June 1999.
A hearing was held in Sydney on 27 and 28 July 2000. Dr Annabelle Bennett SC of counsel and Dr Colin Bodkin and Mr David Myers of Spruson and Ferguson represented Nippon. Mr David K Catterns QC of counsel and Mr Geoff Mansfield and Mr Gennarro Simonetta of Griffith Hack, represented BHP. Mr Udo Beucher of BHP attended as an observer.
SPECIFICATION
The specification as accepted has been the subject of three sets of proposed amendments. One set of amendments, filed on 27 April 1997, has been advertised and allowed in the usual way. The specification is also the subject of some proposed amendments filed on 13 and 27 June 2000. Although leave to amend has been granted, the required advertising period for opposition has not yet expired so the amendments have not yet been allowed. In view of this I propose to consider the specification as amended by the amendments of 27 April, but am prepared to hear submissions in respect of the proposed amendments of June 2000.
The specification, as amended, is directed to an as cast thin sheet steel having excellent stretch-flange ability. This is the term used to describe the property of the steel being sufficiently strong yet ductile enough to be punched into the desired shape, without tearing at the edges. To do this it is vital to control the crystal structure of the steel to ensure that it is sufficiently fine. Traditionally such steel has been made by casting thick slab, and then hot rolling it. This specification proposes a new method of production, which involves continuously casting the strip to the required size and subjecting it to a specific cooling regime specified by a logarithmic equation relating to the steel composition. [From figure 1 of the specification this equates to actual cooling rates between 5°C/sec and 100°C/sec.] This enables the steel to attain the required grain structure thus ensuring the desired properties, without the need for hot rolling of slab.
The specification then ends with 5 claims which read as follows:
1. A thin sheet steel having an excellent stretch-flange ability, characterized by comprising, in terms of % by weight, 0.01 to 0.20% of C, 0.005 to 1.5% of Si, 0.05 to 1.5% of Mn and not more than 0.03% of S with the balance consisting of Fe and unavoidable impurities, and having a sheet thickness in the range of from 0.5 to 5mm, a tensile strength of not less than 35kgf/mm2 and a structure of which at least 95% comprises a bainite having a packet size of 30 to 300mm, packet being as hereinbefore defined, a transgranular acicular ferrite or a mixture thereof.
2. A thin sheet steel according to claim 1 which further comprises, in terms of % by weight, 0.0005 to 0.0100% of Ca or 0.005 to 0.050% of REM.
3. A process for producing a thin sheet steel having an excellent stretch-flange ability, characterized by comprising the steps of: subjecting a steel comprising, in terms of % by weight , 0.01 to 0.20% of C, 0.005 to 1.5% of Si, 0.05 to 1.5% of Mn and not more than 0.03% of S with the balance consisting of Fe and unavoidable impurities, to continuous casting into a thin cast strip having a casting thickness in the range from 0.5 to 5mm; cooling said thin cast strip from the temperature range of from the casting temperature to 900°C to a temperature not higher than 650°C at an average cooling rate of not less than V( °C/sec) represented by the following formula(1); and coiling the cooled strip at a temperature range of 400°C to 650°
Log V ³ 0.5-0.8 log Ceq(°C/sec) ….(1)
Wherein Ceq= C +0.2 Mn4. The process according to claim 3, wherein said steel further comprises, in terms % by weight, 0.0005 to 0.0100% of Ca or 0.005 to 0.050% of REM.
5. The process according to claim 3 or claim 4 , wherein said rolling is carried out with a reduction ratio of not more than 20% between casting and coiling.
The effect of the June 2000 proposed amendments is to combine claims 3 and 5. The claims as proposed to be amended read as follows:
1. A thin sheet steel having an excellent stretch-flange ability, characterized by comprising, in terms of % by weight , 0.01 to 0.20% of C, 0.005 to 1.5% of Si, 0.05 to 1.5% of Mn and not more than 0.03% of S with the balance consisting of Fe and unavoidable impurities, and having a sheet thickness in the range of from 0.5 to 5mm, a tensile strength of not less than 35kgf/mm2 and a structure of which at least 95% comprises a bainite having a packet size of 30 to 300m, packet being as hereinbefore defined, a transgranular acicular ferrite or a mixture thereof.
2. A thin sheet steel according to claim 1 which further comprises, in terms of % by weight, 0.0005 to 0.0100% of Ca or 0.005 to 0.050% of REM.
3. A process for producing a thin sheet steel having an excellent stretch-flange ability, characterized by comprising the steps of: subjecting a steel comprising, in terms of % by weight , 0.01 to 0.20% of C, 0.005 to 1.5% of Si, 0.05 to 1.5% of Mn and not more than 0.03% of S with the balance consisting of Fe and unavoidable impurities, to continuous casting into a thin cast strip having a casting thickness in the range from 0.5 to 5mm; cooling said thin cast strip from the temperature range of from the casting temperature to 900°C to a temperature not higher than 650°C at an average cooling rate of not less than V( °C/sec) represented by the following formula(1); optionally rolling said thin cast strip with a reduction ratio of not more than 20%; and coiling the cooled strip at a temperature range of 400°C to 650°:
Log V ³ 0.5-0.8 log Ceq(°C/sec) ….(1)
Wherein Ceq= C +0.2 Mn4. The process according to claim 3, wherein said steel further comprises, in terms % by weight, 0.0005 to 0.0100% of Ca or 0.005 to 0.050% of REM.
At the hearing, both counsel were of the clear view that the proposed amendments did not affect the novelty or inventive step arguments in any way.
The term packet is defined in the specification as follows:
"The term "packet" used herein is intended to mean a group of small units of a low-temperature transformation phase comprising a group of similar grain orientations which are identified by etching or the like".
Thus I propose to deal with the claims as amended on 27 April 1997.
GROUNDS OF OPPOSITION
BHP's grounds for opposing the application are, that the claimed invention is not novel and does not involve an inventive step, when compared with the information available or known at the date of the present application; that the claimed invention is not a manner of manufacture and that the specification does not comply with section 40 of the Patents Act 1990.
EVIDENCE
BHP has served evidence consisting of statutory declarations and accompanying exhibits by Dr Massoud Assefpour, Mr Iain Farr, Mr Alan Blatherwick. These are all employees or former employees of BHP. There are also declarations by Ms Pettit-Young and Ms Luther both of whom are librarians attesting to the publication date of certain documents.
Nippon have served evidence consisting of a statutory declaration by Dr Roy Southin. Dr Southin is a retired consulting metallurgist.
I will refer to the evidence and the parties' submissions where appropriate in my decision.
DECISION
PRIORITY DATE
The opponent alleges that the application is not entitled to its convention priority because it is based on Japanese application No 99891/93 dated 26 April 1993. However the present applicant is claiming priority from International Patent Application No PCT/JP94/00699, [which itself claims priority from Japanese application No 99891/93] rather than being merely the national phase of the international application. Thus on the face of it, the present application, being made more than 12 months after Japanese application No 99891/93, is only entitled to a priority date of October 1994 [its date of lodgement in Australia] rather than the claimed priority date of 26 April 1994. In any event nothing appears to turn on the priority date. Four of the documents relied on for novelty were published before either of these dates The only other document which is only relied on for "whole of contents" novelty was published after, and has a priority date before both dates. I therefore do not need to decide which of these dates is the true priority date of this application.
NOVELTY
The test for determining whether the invention lacks novelty is the " reverse infringement test" as set out in Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 288 at page 235 where Aiken J stated:
"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask whether the alleged anticipation would, if the patent were valid, constitute an infringement."
Infringement occurs when "each and every one of the essential features" of the claim have been disclosed in the prior document: See Rodi and Wienenberger AG v Henry Showell Ltd (1969) RPC 367 at page 391. However, the claim will still lack novelty even if the citation does not disclose all of the features of the claim provided all essential features are disclosed: See Nicaro Holdings v Martin Engineering (1990) 16 IPR 545 and Catnic Components Ltd v Hill and SmithLtd (1982) RPC 183.
I must therefore construe the claims and determine their essential features.
The essential features of claim 1 are:
A thin steel sheet of between 0.5 to 5mm;
Having a composition by weight of
0.01 to 0.20% C;
0.005 to 1.5% Si;
0.05 to 1.5% Mn;
no more than 0.03%S;
balance iron and unavoidable impurities;
a tensile strength not less than 35kgf/mm2 ;
a structure having at least 95% bainite or transgranular acicular ferrite or a mixture of the two and;
bainite if present must have a packet size of 30 to 300mm.
I do not consider the fact that the sheet has excellent stretch flange ability to be an essential feature in its own right. Rather in my view it is an inevitable property of a sheet having all the other characteristics.
The independent process claim 3 has the following essential features:
Subjecting the steel of the same chemical composition as claim 1 to continuous casting
Forming a strip of between 0.5 to 5mm;
Cooling the strip from the range of the casting temperature to 900°C to not higher than 650°C at an average cooling rate of V (°C/sec)
Coiling the cooled strip at a temperature of 400°C to 650°C
Wherein log V ³ 0.5-0.8 log Ceq (°C/sec)….(1)
Wherein Ceq =C + 0.2Mn
Again it is my view that the feature of excellent stretch flange ability is an inevitable consequence of the process used and the chemical composition of the steel.
In assessing the teaching or disclosure of the prior art, one has to consider what the skilled addressee is being taught and what they would have done on reading the citation, General Tireand Rubber Co v Firestone Tyre and Rubber Co Ltd, (1972) RPC 457 at 485,486:
"To anticipate the patentee's claim, the prior publication must contain clear and unmistakable directions to do what the patentees claims to have invented...a signpost, however clear, upon the road to the patentee's invention will not suffice"
Although a large number of documents were particularised the opponent only relied on five of the earlier documents, which I shall deal with individually:
Japanese Patent Publication 2-236228 to Nippon Steel Corporation
Published 19 September 1990
This document, entitled "Method of producing high-strength steel sheet" discloses the production of thin sheet steel having an excellent balance between strength and ductility. [I understand this as the same as a steel having excellent stretch flange ability.] It does this by utilising a continuous casting process to produce a sheet of between 1 and 10 mm. [As does the opposed specification.] The chemical composition of this steel with two notable exceptions falls within the chemical composition claimed by the patent in suit.
The citation clearly contemplates not having to hot roll the "as cast" product to obtain the desired fine ferrite crystal structure. Whilst it attempts to control the crystal structure by controlling the cooling rate it also requires the addition of Titanium as "the most important element of the invention". The teaching is that, instead of the austenite grain diameter being determined by the cooling rate alone, the addition of the Titanium [and to a lesser extent Boron] provides sites for the growth of fine ferrite [rather than coarse austenite] crystals.
This citation also specifically states that bainite is not formed, whereas the present invention specifically seeks to produce bainite and claims it.
Thus although the citation seeks to solve the same problem addressed by the patent in suit it does it in a completely different fashion by the addition of Titanium and Boron, rather than relying solely on controlled cooling of the cast thin sheet.
Thus it does not anticipate any of the claims.
Japanese Patent Publication 2-236224 to Nippon Steel Corporation
Published 19 September 1990
This document entitled "Method of producing high-tension steel sheet having excellent toughness" discloses the production of thin sheet steel by continuous casting. The citation seeks to solve the same problem as the present invention, namely the production of a fine ferrite crystal structure by way of carefully controlled cooling of the as cast strip. The main thrust of the disclosure is an alloy containing Carbon Manganese and Sulphur in amounts which at least overlap with the claimed invention, but have no Silicon present. There is also a table which contains an alloy which Mr Catterns submitted was equivalent to the composition claimed. In particular he referred to the alloy "C" on page 9 table 1 of the citation. All the other alloys in the table have substantial quantities of Titanium and Boron present and are thus similar in scope to Japanese Patent Publication 2-236228 where the Titanium and Boron additions are what controls the crystal structure.
Although alloy "C" has no Titanium or Boron, it does have amounts of Aluminium and Phosphorus, which are at levels that do not in my view amount to the level of the "unavoidable impurities" of the claims of the opposed specification. In fact the aluminium at 0.02% is twice the lower limit of 0.01% of the carbon level in the steel of the opposed specification and could hardly qualify as an unavoidable impurity. I also note that in the opposed specification at page 14 there is a table which lists other elements that may be present in the steel of the invention. They include Copper at 0.1% and Tin at 0.03% and Chromium at 0.08%, but not Aluminium or Phosphorus.
Consequently this citation does not anticipate any of the claims of the opposed specification, regardless of whether the cooling rates are the same, because the alloy is of a different composition.
Japanese Patent Publication 4-21723 to Nippon Steel Corporation
Published 24 January 1992
This citation is directed to a method of producing cold rolled strip [my emphasis]from a continuously cast thicker strip. In addition to the chemical composition of the steel not being the same as the opposed specification, there is no teaching of controlling the grain structure of the finished strip solely by controlled cooling of the as cast strip. The citation at page 6 even states that "the cooling and heating conditions of the thin cast strip are the most important aspect of the present invention". [My emphasis]
Consequently this citation does not anticipate any of the claims of the opposed specification.
PCT Application No PCT/AU94/00678 (Australian Application No 81004/94) to Ishikawajima-Harima Heavy Industries Company limited and BHP Steel (JLA) Pty Ltd
Published 1 May 1995
This citation can only be considered in respect of a "whole of contents" novelty objection. Its publication date is later than either of the possible priority dates of the opposed specification, whilst its priority date is before either of the relevant dates. It discloses a method of producing low carbon steel strip from a continuously cast strip by cooling re-heating [my emphasis] and then cooling. Whilst the citation is directed to producing fine grained ferrite in the finished product, no steel composition is actually specified [unlike the opposed specification which is quite specific about its steel composition]. It does not specify the percentage of fine ferrite, the strip thickness or the tensile strength. I am not of the view that these details would form part of the common general knowledge, but even if they did this citation still discloses a multi stage process rather than the single stage one of the opposed specification.
Consequently this citation does not anticipate any of the claims of the opposed specification.
United States Patent Specification 4851052 to Nippon Steel Corporation
Published 25 July 1989
This citation is directed to a method of producing a thick steel plate by continuously casting and then hot charge rolling without the use of titanium. Although some of the examples illustrate a process with no rolling there is only one example in the citation that is sufficiently thin to overlap with the thin strip of the present invention. The chemical composition of the steel does overlap with that of the claimed invention [I regard the small amounts of aluminium and oxygen in the steel of the citation to be within the range of the unavoidable impurities of the invention]. The object of the citation is produce steel having an acicular ferrite structure by means of hot charge rolling and controlled cooling. The citation also discloses cooling rates within the scope of the invention. What it does not disclose is the exact thickness of as cast strip [as opposed to plate which is thicker] with the right cooling regime, no rolling and the crystal structure such that 95% comprises a bainite having the stated packet size or acicular ferrite .
The citation does not have all the essential features of any of the claims of the opposed specification, and does not deprive the claims of novelty.
In summary all of the claims of the specification, as amended by the amendments of 27 April, 1997 are novel in the light of all the above citations. The proposed amendments of 13 and 27 June 2000 do not alter this situation.
INVENTIVE STEP
Inventive step is determined in the light of the common general knowledge existing in the relevant field at the priority date of the application.
Summarising subsections 7(2) and 7(3) of the Patents Act, a claimed invention will lack an inventive step if it is obvious in the light of:
(a) common general knowledge existing in the art before the priority date considered alone; or
(b) common general knowledge existing in the art before the priority date considered together with information in a single document or through doing a single act, provided that the skilled person could before the priority date, be reasonably expected to have ascertained, understood and regarded the information from the document or act as relevant to work in the relevant art in the patent area.
It appears that the state of the common general knowledge in Australia that I can ascertain was the following:
Twin roll continuous casting of steel is known. By its very nature this requires rapid cooling of the steel in order to ensure that although molten steel enters the rolls, solid steel leaves them [ I am not of the view that the specific cooling rates were part of the common general knowledge];
this type of casting is suitable for producing by direct casting strip of a thickness normally obtained by the separate step of hot rolling much thicker cast slab;
on cooling cast steels form particular crystal structures depending on their thermal history [ie the way they are cooled and/or reheated];
coiling of twin roll continuously cast steel is known as a convenient way of handling the product produced
By itself, this common general knowledge is not sufficient to deprive the claims of the opposed specification of an inventive step. It does not specify an exact cooling rate. It does not specify the bainite or acicular ferrite percentages. In short, it does not deprive the claims of an inventive step.
I must now consider whether any of the documents already relied on by the opponent for novelty could be the class of document that could reasonably be expected to have been ascertained, understood and regarded as relevant to work in the relevant art in the patent area. If so I can consider information from them with the common general knowledge, otherwise not.
In this instance Japanese Patent Publications 2-236228, 2-236224 and 4-21723, all to Nippon Steel Corporation and relied on by the opponent for novelty, were originally in Japanese and were only translated in 1996. They are documents that could have even been ascertained in Australia before the priority date of the claims, both because of the presence of an English language abstract and because the patentee was Nippon, whom Mr Farr tells us were a rival company whose patents were always carefully watched by BHP. In this particular case Mr Farr clearly states in his declaration that "Where any patent application of interest is in Japanese, English translations thereof are obtained".
Although I have no evidence of persons skilled in the art in Australia being skilled in the Japanese language I am nonetheless prepared to concede that these documents could have been understood and considered relevant. The first two citations are directed to the use of Titanium and Boron as alloying elements to produce the effect obtained in the opposed specification without them. This teaches directly away from the claims of the opposed specification. Thus neither of them deprive any of the claims of an inventive step. The third citation is directed to a method of producing cold rolled strip rather than the present invention which seeks to produce strip without rolling, which again teaches away from the opposed specification. Thus it does not deprive any of the claims of an inventive step.
PCT Application No PCT/AU94/00678 (Australian Application No 81004/94) to Ishikawajima-Harima Heavy Industries Company limited and BHP Steel (JLA) Pty Ltd, published 1 May 1995, is a document which cannot be considered a document that could have even been ascertained in Australia, as it was not published before either of the possible priority dates of the claims and therefore not part of the prior art base for inventive step
United States Patent Specification 4851052 to Nippon Steel Corporation published 25 July 1989 is a patent document that is directed to a method for producing steel plate by the hot charge rolling process. Whilst it is a method that uses a steel without titanium and boron additions it is most definitely directed to casting a slab and rolling it. The present invention is directed to continuously casting a steel strip to size without rolling it. It is aimed at producing the same fine crystal structure as hot rolling without the need for an expensive rolling step. Whilst there are a few examples with no rolling and one example of sufficiently thin plate, the whole thrust of the specification is to produce thicker plate using a rolling step. Whilst it is a document which would have been ascertained and understood and be considered relevant, it is not directed to solving the problem of how to get the same crystal structure as hot rolled slab without a rolling step Thus it does not deprive any of the claims of an inventive step.
In my view none of the claims lack an inventive step.
MANNER OF MANUFACTURE
The opponent argued that the claims of the opposed patent were not a manner of manufacture; but were "a claimed use that is nothing but a new use of an old substance which is not a proper subject of letters patent."
In Advanced Building Systems Pty Ltd v Ramset Fasteners (Aust) Pty Ltd (1998) 40 IPR 243 the High Court expressly preserved the interpretation of this ground in Commissioner of Patents v Microcell Ltd (1959)102 CLR 232at 5-6. It regarded NV Phillips Gloeilampenfabrieken vMirabella International Pty Ltd (1995) 183 CLR 655 as continuing authority (at least for new act patents) for the proposition that a claimed use that is nothing but a new use of an old substance is not a proper subject of letters patent: [see p 255]
The opponent's argument has been that because the alleged invention is not a manner of new manufacture it is not a manner of manufacture at all. Since I have found that all claims are novel and exhibit an inventive step, I am of the view that they are also a manner of manufacture.
SECTION 40
Invention not fully described
The opponent argued at the hearing that the term "a packet size of 30 to 300mm" is not an expression in general use in the technical literature. However the specification at page 2 defines what is intended by a packet and so in my view this term is clear enough.
There was also some argument that the term stretch flange ability was also not well known. As I have indicated earlier, nothing in particular turns on this term. As far as I can ascertain it is a term coined by Nippon to attempt to measure the suitability of steel for punching into shapes without tearing. The test devised although it might be arbitrary, is described in sufficient detail to enable it to be performed by a skilled addressee. It can thus be used to measure competing steels to see if they infringe.
Thus in my view the specification meets the requirements of section 40.
CONCLUSION
The opponent has failed to prove the lack of an inventive step in the light of the common general knowledge alone. Of the five documents sought to be considered with the common general knowledge, three were not translated into English before the priority date and although they could have been ascertained they could not have been understood and considered relevant. The fourth document was not publicly available before the relevant date. The combination of the fifth document and the common general knowledge was not sufficient to deprive the claims of an inventive step.
All the claims are novel in the light of the documents relied on at the hearing by the opponent. The specification meets the requirements of section 40.
I have found that the opposition has failed and that the amendments, proposed on 13 and 27 June 2000, but as yet not allowed, do not affect the outcome. I therefore direct that the application be sealed after 30 days from the finalising of the proposed amendments. If the Commissioner has been served with a notice of appeal before that time, I direct that sealing not occur until the appeal has been decided or discontinued.
COSTS
Both parties asked that costs should follow the event. Since the opposition has not been successful, I award costs against BHP.
R.A.Melvin
Delegate of the Commissioner of Patents
Patent attorneys for the applicant: Spruson and Ferguson Sydney
Patent attorneys for the opponent : Griffith Hack Melbourne
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