Sealed Air Corporation v Kureha Corporation - [2013] APO 70

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Sealed Air Corporation v Kureha Corporation [2013] APO 70

Patent Application: 2007216113

Title:Heat shrinkable multilayer film and packaging material using same

Patent Applicant:  Kureha Corporation
Opponent:  Sealed Air Corporation
Delegate:  Dr S.D. Barker
Decision Date:  20 December 2013
Hearing Date:  7 November 2013, in Canberra
Catchwords:  PATENTS – opposition to the grant of a patent – grounds of novelty and inventive step considered – citation does not disclose use of a nylon with a melting point above 210° – citation is relevant because the problem is addressed to improving the film that it discloses – no reason to focus on modifying the nylon layer – opposition fails on all grounds – costs awarded against the opponent

Representation: Patent applicant: Tom Cordiner of counsel assisted by Brett Connor of Freehills Patent Attorneys
Opponent:Rachel Hooke and Edmund Walker of FB Rice

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Patent Application: 2007216113

Title:Heat shrinkable multilayer film and packaging material using same

Patent Applicant: Kureha Corporation
Date of Decision: 20 December 2013
DECISION
The opposition is not successful.
Subject to appeal, I direct that the application proceed to grant.
I award costs according to Schedule 8 against Sealed Air Corporation.
REASONS FOR DECISION

The present application was filed in Japan as a PCT application that designated Australia on 15 January 2007. The applicant is Kureha Corporation (Kureha). The application was examined and accepted by the Commissioner, and subsequently opposed by Sealed Air Corporation (SAC). A hearing was held on 7 November 2013 in Canberra to decide the opposition. Kureha was represented by Tom Cordiner of counsel assisted by Brett Connor of Freehills Patent Attorneys. SAC was represented by Rachel Hooke and Edmund Walker of FB Rice.
The opposition
The statement of grounds and particulars identified four grounds of opposition: manner of manufacture, novelty, inventive step and section 40. At the hearing, the opposition was limited to the grounds of novelty and inventive step.
The parties relied upon evidence by several declarants. Evidence in support consists of two declarations by David Henry Solomon. Evidence in answer consists of two declarations by Alan G Anderson. Evidence in reply consists of a declaration by David Henry Solomon. I will refer to the relevant parts of the evidence where appropriate.
The specification
The specification relates to films that can be used as a packaging material. The films are composed of layers of polymer materials. Due to the way that the film is produced, it has the property that it will shrink when heated, thus securely wrapping the contents. The specification ends with a single Figure and 12 claims. Claim 1 is the only independent claim.
What is the invention as described
Before commencing to construe the specification, I note what Middleton J said in Eli Lilly and Company Limited v Apotex Pty Ltd [2013] FCA 214, 100 IPR 451 at [139]:
"It is well settled that the Court should, from the outset, approach the task of patent construction with a generous measure of common sense. The Court must place itself in the position of a person skilled in the relevant art, being the subject matter of the patent. From this perspective, the patent is to be read as a whole, in the context of the specification and in light of the prevailing common general knowledge and state of the relevant art at the priority date."
The background to the invention
The specification discusses a single prior art document (Japanese application 2002-172746). The disclosure of this document is explained at pages 1 – 2:
"a heat shrinkable multilayer film comprising at least three layers of an outer surface layer (a) formed of a thermoplastic resin, an intermediate layer (b) formed of a polyamide resin and an inner surface layer (c) formed of a sealable resin as a film satisfying these various characteristics. The thermoplastic resin forming the outer surface layer (a) is a polyester resin or polyolefin resin. The polyamide resin forming the intermediate layer (b) is a mixture of 60 to 85% by weight of an aliphatic polyamide resin and 15 to 40% by weight of an aromatic copolymer polyamide resin that is a copolymer of aliphatic diamine / isophthalic acid and aliphatic diamine / terephthalic acid. The sealable resin forming the inner surface layer (c) is essentially a copolymer having a density of less than 0.915 and composed of ethylene and an α-olefin. The heat shrinkable multilayer film is heat-treated after biaxial stretching treatment, and the shrink of the heat shrinkable multilayer film in water at 80°C is 30% or higher in each of machine and transverse directions. Document 1 describes a heat shrinkable multilayer film using a nylon 6-66 copolymer with a melting point of about 195°C as the above aliphatic polyamide resin."
The specification reaches the conclusion that this product
"is still insufficient in heat resistance and high-temperature creep resistance though the film is sufficient in heat shrinkability, tensile strength, moldability, suitability for various packages, gas barrier properties, water vapour barrier properties and optical property"
[page 2]
The aim of the invention
The invention of the specification is then stated to have "been made in view of the problems involved in the prior art" [page 3]. As the only prior art identified is JP 2002-172746, it seems that the specification is asserting that the aim is to provide an improvement on the film disclosed in this document. Since the problems with this film relate to heat resistance and high-temperature creep resistance, it is reasonable to view these properties as the focus of the invention.
At the hearing, Mr Cordiner submitted that the aim of the invention should be seen more broadly, and the prior art document JP 2002-172746 is part of the solution to that problem. The difficulty is that there is no evidence that suggests what this different problem might be. Mr Cordiner was not able to point to any part of the specification that suggests a different problem. I have studied the specification at length, and I can find nothing that could be viewed as an alternative problem. I have also reviewed the declarations in evidence, and I cannot find any suggestion that there was a known or recognised problem in the art of heat shrink films. Mr Anderson discusses the specification in his second declaration, but he does not comment on what he considers was the aim of specification.
The submission that the problem addressed by the specification should be viewed differently is based on speculation that is not supported by the evidence. I have no basis to conclude that the problem should not be formulated as above.
The nature of the invention
The specification says that the invention
"provides a heat shrinkable multilayer film that highly satisfies various properties such as heat shrinkability, strength, heat resistance, high-temperature creep resistance, moldability, suitability for various packages, gas barrier property, water vapour barrier property and optical property, and is excellent in heat resistance and high-temperature creep resistance in particular"
[page 3]
The specification explains the technical features of the invention in general terms:
"The present inventors have carried out an extensive investigation with a view toward achieving the above-described aspect. As a result, it has been found that a combination of an outer surface layer (a) formed of a ethylene terephthalate / isophthalate copolymer, a first intermediate layer (b1) formed of a polyimide resin having an extremely limited composition, a second intermediate layer (b2) formed of a thermoplastic resin having a specific composition, and an inner surface layer (c) formed of a polyolefin resin provides a heat shrinkable multilayer film that highly satisfies various properties such as heat shrinkability, tensile strength, heat resistance, moldability, suitability for various packages, gas barrier property, water vapour barrier property and optical property, and is excellent in heat resistance and high-temperature creep resistance in particular, thus leading to completion of the present invention."
[page 3]
and subsequently in more precise terms:
"A heat shrinkage multilayer film according to the present invention is heat shrinkable multilayer film comprising an outer surface layer (a) formed of a ethylene terephthalate / isophthalate copolymer, a first intermediate layer (b1) formed of a polyamide resin, a second intermediate layer (b2) formed of a saponified product of an ethylene-vinyl acetate copolymer, and an inner surface layer (c) formed of a polyolefin resin, wherein
shrinkage of heat shrinkable multilayer film in water at 90°C is within a range of from 3 to 45% in each of machine and transverse directions, and
the polyamide resin is a mixture of 60 to 90% by weight of an aliphatic polyamide having a melting point of 210°C or higher and 10 to 40% by weight of an aromatic polyamide comprising isophthalic acid and terephthalic acid as acid components."
[page 4]
The specification then follows a familiar layout in providing a list of preferable forms of the invention, and preferred embodiments.
Construction of claim 1
The correct approach to the construction of claims was discussed by Bennett J in H Lundbeck A/S v Alphapharm Pty Ltd [2009] FCAFC 70, 81 IPR 228 at [118] – [120]:
"the words in a claim should be read through the eyes of the skilled addressee in the context in which they appear … while the claims define the monopoly claimed in the words of the patentee's choosing, the specification should be read as a whole … it is not permissible to read into a claim an additional integer or limitation to vary or qualify the claim by reference to the body of the specification … terms in the claim which are unclear may be defined or clarified by reference to the body of the specification"
Claim 1 is the independent claim. It reads
A heat shrinkable multilayer film comprising an outer surface layer (a) formed of a ethylene terephthalate/isophthalate copolymer, a first intermediate layer (b1) formed of a polyamide resin, a second intermediate layer (b2) formed of a saponified product of an ethylene-vinyl acetate copolymer, and an inner surface layer (c) formed of a polyolefin resin, wherein
shrinkage of heat shrinkable multilayer film in water at 90°C is within a range of from 3 to 45% in each of machine and transverse directions,
the polyamide resin is a mixture of 60 to 90% by weight of an aliphatic polyamide having a melting point of 210°C or higher and 10 to 40% by weight of an aromatic polyamide comprising isophthalic acid and terephthalic acid as acid components, and
the multilayer film is obtained by stretching a multilayer film comprising the outer surface layer (a), the first intermediate layer (b1), the second intermediate layer (b2) and the inner surface layer (c) at a draw ratio of from 2.5 to 4 times in each of machine and transverse directions and then subjecting the stretched film to a heat relaxation treatment so as to give a relaxation ratio of from 2 to 40%.
The film is defined as "comprising" four specified layers. The specification provides a dictionary definition that indicates that this language is intended to be inclusive:
"As used herein, except where the context requires otherwise, the term 'comprise' and variations of the term, such as 'comprising', comprises' and comprised', are not intended to exclude other additives, components, integers or steps."
[page 6A]
In the context of claim 1, it is reasonable for the film to contain further layers in addition to the four that are specified. Consequently, in line with the dictionary provided, I consider that the film can contain more than four layers. However, layers (a) and (c) must be the outer layers.
Novelty

18. Subsection 7(1) of the Patents Act (the Act) states that an invention is taken to be novel unless it is not novel in the light of the prior art. A citation is part of the prior art base for the purposes of novelty if it was published before the priority date of the claim.
19. It is well established that the general test for lack of novelty is the reverse infringement test. The classic formulation of this test is that given by Aickin J in Meyers Taylor Pty Ltd v Vicarr Industries Ltd [1977] HCA 19 at [20], 137 CLR 228 at 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"

20. Australian courts have often cited with approval the words of the UK Court of Appeal in The General Tire & Rubber Company v The Firestone Tyre and Rubber Company Limited [1972] RPC 457 (the General Tire case) at 485 – 486:
"If the prior inventor's publication contains a clear description of, or clear instructions to do or make, something that would infringe the patentee’s claim if carried out after the grant of the patentee's patent, the patentee's claim will have been shown to lack the necessary novelty, that is to say, it will have been anticipated. The prior inventor, however, and the patentee may have approached the same device from different starting points and may for this reason, or it may be for other reasons, have so described their devices that it cannot be immediately discerned from a reading of the language which they have respectively used that they have discovered in truth the same device; but if carrying out the directions contained in the prior inventor's publication will inevitably result in something being made or done which, if the patentee's patent were valid, would constitute an infringement of the patentee's claim, this circumstance demonstrates that the patentee's claim has in fact been anticipated.
If, on the other hand, the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee's claim, but would be at least as likely to be carried out in a way which would not do so, the patentee's claim will not have been anticipated, although it may fail on the ground of obviousness. To anticipate the patentee's claim the prior publication must contain clear and unmistakeable directions to do what the patentee claims to have invented: Flour Oxidizing Co. Ltd. v. Carr & Co. Ltd. (1908) 25 R.P.C. 428 at 457, line 34, approved in B.T.H. Co. Ltd. v. Metropolitan Vickers Electrical Co. Ltd. (1928) 45 R.P.C. 1 at 24, line 1). A signpost, however clear, upon the road to the patentee's invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee."

SAC relied on one citation to allege lack of novelty: EP 1190847.
EP 1190847
EP 1190847 (D1) was published on 27 March 2002. Consequently it is part of the prior art base.
D1 discloses heat shrinkable multilayer films having at least three layers. The layers are an outer thermoplastic resin layer, and intermediate polyamide layer, and an inner heat sealable resin layer. The most important layer for the purposes of this decision is the polyamide layer. This layer is described at [0018] as follows:
"The polyamide resin (sometimes abbreviated as 'PA') forming the intermediate layer (b) used in the present invention comprises a mixture of 85 – 60 wt % an aliphatic polyamide resin, and 15 – 40 wt % of an aromatic copolyamide resin which is a copolymer of aliphatic diamine/isophthalic acid and aliphatic diamine/terephthalic acid (sometimes called 'nylon 6I/6T')."
The aliphatic polyamide is further described at [0021]:
"On the other hand, the aliphatic polyamide resin may include an aliphatic polyamide homopolymer and an aliphatic polyamide copolymer. The aliphatic polyamide homopolymer may for example include nylon 6 and nylon 66. Examples of aliphatic polyamide copolymer may include: nylon 6/66, nylon 6/69, nylon 6/610, nylon 66/610, and nylon 6/12. These aliphatic polyamide resins may be used singly or in mixture of two or more species thereof, e.g. nylon 6 and nylon 6/66, or nylon 6 and nylon 66. The use of an aliphatic polyamide copolymer may easily provide a stably high hot-water shrinkability. Among the above, nylon 6/66 and nylon 6/69 are further preferred because of a good mutual solubility with the aromatic copolyamide resin."
The critical question that arises from the General Tire case is whether a person following the directions in D1 would inevitably have prepared a film using a nylon with a melting point above 210°. This question focusses on nylon 6 and nylon 66, as these nylons can have a melting point above 210°.
The examples in D1 use a nylon 6/66 with a melting point of 195° (NY-1), a nylon 6/66 with a melting point of 193° (NY-2), a nylon 6/12 with a melting point of 155° (NY-6), a nylon 66/610 with a melting point of 181° (NY-7) and several amorphous nylon 6I/6T copolymers (NY-3, NY‑4, NY-5). There are no examples of films prepared from a nylon 6 or nylon 66 per se, or any nylon with a melting point above 210°.
The disclosure of nylon 6 and nylon 66 is simply the broad statement at paragraph [0021], where nylon 6 and nylon 66 are mentioned as two amongst many. There is no inevitability that nylon 6 or nylon 66 would have been used. I am not satisfied that D1 contains clear and unmistakable directions to use nylon 6 or nylon 66.
It follows that it is not necessary to decide whether nylon 6 (or nylon 66) has a melting point above 210°, and whether it would have been more likely that the nylon 6 in D1 would have a melting point above 210° rather than below 210°.
Inventive step
Subsection 7(2) of the Act states that an invention is taken to involve an inventive step unless it would have been obvious to a person skilled in the art in the light of the common general knowledge, considered alone or together with the prior art. A document is prior art for this purpose if "a skilled person mentioned in subsection (2) could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood, regarded [the document] as relevant" (subsection 7(3)).
The test for whether an invention is obvious is to ask whether it would have been a matter of routine to proceed to the claimed invention. In Wellcome Foundation Ltd v V.R. Laboratories (Aust.) Pty Ltd [1981] HCA 12 at [45], 148 CLR 262 at 286 Aickin J stated:
"The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not."
The High Court in Aktiebolaget Hassle v Alphapharm Pty Ltd [2002] HCA 59, 212 CLR 411 approved this approach.
In the present case the problem addressed by the specification is the provision of a film with improved heat resistance and high-temperature creep resistance compared to JP 2002-172746 (which is the Japanese equivalent of D1). The sole citation relied upon is D1.
The threshold question is whether D1 would have been ascertained, understood and regarded as relevant. In his first declaration, Mr Anderson said
"I would like to comment generally about how a person skilled in the art approaches the design of a heat shrinkable film.
Initially, the technical specialist would consider the application for the film and the properties and performance criteria required of that film for the intended application. With regard to the packaging industry, some of the general film properties that need to be considered include: moisture barrier properties, gas barrier properties, and sealability etc.
As a starting point, I would select polymers having properties that would impart desired characteristics to each layer of the multilayer film which could potentially result in a multilayer film which has the desired properties and meets the required performance criteria.
This process would include assessing polymers and polymer blends that are commercially available, and reviewing the properties and characteristics of these polymers and polymer blends, the properties of which can be obtained from Technical Data sheets provided by suppliers. The selection process would, in part, be based on my knowledge and previous experience working with similar multi layered film combinations."
[para 10 – 13]

Mr Anderson stated in his first declaration at [73] that he generally did not consider the patent literature:
"as a person skilled in the art, I would not generally consult patent literature when designing or modifying a multilayer film"
In the present case, the problem is not to solve a problem associated with a specific application of a film. Indeed, it is not apparent to me from either the specification or the evidence what application is intended for the film. Instead, the problem addressed by the specification is to make improvements in the heat resistance and creep resistance of the film in D1. In this situation, a person would have ensured that they ascertained D1 and considered it relevant in order to fully understand the problem.
Upon a full consideration of D1, it is apparent that it suggests that the aliphatic polyamide can be nylon 6 or nylon 66, or copolymers thereof. D1 provides no reason to think that the use of these alternatives would be likely to lead to the improvements that were desired.
I turn now to what the declarants say they would have done in the light of D1. Mr Solomon says that his first choice would have been to modify the polyamide:
"if I was provided with the film of D1 and asked to improve the heat resistance and temperature creep resistance, I do not believe that there are so many variables that this would be impossible to achieve. First and foremost I would look to modify the polyamide layer to raise the softening temperature. To do this I would select a nylon which has a higher melting point than the nylons used in the examples of D1 and provided in Table 3."
[third Solomon declaration at para 16]
"if I was to start the process of preparing an improved film over D1, I would start with the examples of Table 3, run tests to establish the properties of these films. Then I would look to see what I should change first to move towards a film that had improved heat resistance and improved creep resistance. As I noted, this means that the softening temperature should increase and the most obvious place to start is with the nylon layer … I would first change the nylon 6/66 for a nylon with a higher softening temperature."
[third Solomon declaration at 41]
Mr Anderson says that he would have considered modifying other layers:
"when looking to improve a number of properties of the multilayer film of EP 1190849, the blends of polyamide and EVOH, the selection of certain polyamide copolymers as well as the polymers for some of the inner/outer polymer layers would have significance with respect to the characteristics of the film. However, the results of any change cannot be reliably predicted. Small variations can have a large impact on material properties, and this effect is not always predictable."
[second Anderson declaration at para 24]
Mr Anderson suggested a number of different changes at [26] of his second declaration:
. adding a further layer
. modifying an existing layer
. modify either or both the aliphatic polyamide and aromatic polyamide
Mr Anderson also considered the problem as I have identified it:
"I was asked if looking to improve the heat resistance and high temperature creep resistance properties of the exemplified films shown in EP 1190847, of all the aliphatic polyamides disclosed, would I have been drawn to nylon 6 or nylon 66, and would I have expected positive results."
[second Anderson declaration at para 33]
The question is partially answered at [37]:
"in my opinion, in order to improve the heat resistance and high temperature creep resistance consideration may be given to nylon 6 and/or nylon 66. However, other aliphatic and aromatic polyamides would also be investigated. The reasoning behind this is discussed in AGA-6. Additionally, the trained polymer technologist would have knowledge of how the selection of polymerisation components can change the properties of a polymer."
This evidence seems to say that if it was recognised that the nylon layer was the way to address the problem, it would have been likely that a person would have investigated higher melting point nylons. However, I cannot see why the nylon layer would have been seen as the place to focus attention. It seems to me that knowledge of the solution may have coloured the evidence.
I am not satisfied that the evidence supports a conclusion of lack of inventive step.
Conclusion
It has not been established that the claims lack novelty or inventive step. Subject to any appeal that may be filed, the application should proceed to grant.
Costs
The parties submitted that costs should follow the event. I see no reason to depart from that result. Costs should be awarded against SAC.
Dr S.D. Barker
Delegate of the Commissioner of Patents