Viskase CORPORATION v Kureha Kagaku KKK
[2001] APO 17
•17 April 2001
OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Application : No. 664308 in the name of VISKASE CORPORATION
Title: A HEAT SHRINKABLE NYLON FOOD CASING WITH A POLYOLEFIN CORE LAYER
Action: Opposition by KUREHA KAGAKU KKK
Decision: Issued .
Abstract
Opposition fails, ground of manner of new manufacture not established.
The claimed invention was also found to be novel and inventive over the closest prior art document cited by the opponent. EP467039 does not teach or suggest to the skilled worker a food casing with the particular combination of layers and shrinkage values claimed.
PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re:Patent Application No. 664308 in the name of VISKASE CORPORATION, and opposition thereto by Kureha Kagaku KKK under section 59 of the Patent s Act 1990.
BACKGROUND
Patent application 664308 in the name of VISKASE CORPORATION (Viskase) was filed on 22 September 1993 with a priority date of 23 September 1992. The application was advertised as accepted on 9 November 1995.
Kureha Kagaku KKK filed a notice of opposition to the grant of this patent on 9 February 1996, followed by a statement of grounds and particulars on 9 May 1996. Each of the evidentiary stages were subject to a number of extensions while expert evidence was being obtained. Additionally evidence in reply was deferred until after the allowance of S.104 amendments. The evidentiary stages were finally completed on 6 March 2000. The applicant requested to have the hearing on 664308 to be held concurrently with the hearing on their related application 669926. The hearing on 664308 was set down for Canberra on 19 June 2000 with 669926 being heard on the following day. The opponent and the applicant were not represented at the hearing, but both provided written submissions through their attorneys.
STATEMENT OF GROUNDS AND PARTICULARS
The statement of grounds and particulars relies on all grounds of opposition allowed under Section 59:
Section 59(a) The nominated person is not entitled to a grant of a patent for the invention.
Section 59(b) The invention is not a patentable invention because it does not comply with paragraph 18(1)(a) or (b)
Section 59(c) The specification filed in respect of the complete application does not comply with SubSection 40(2) or (3).
GUIDE TO TECHNICAL TERMS AND ACRYNOYMS
I provide below an explanation of some technical terms and acronyms, as I understand them, appearing in this decision:
After-shrinking
"After-shrinking " is a process step where the cooked and cooled sausage (approximately 4oC) is heated to at least 80oC or higher for a few seconds, in a hot water bath or by hot air treatment. During this heat treatment, the casing film shrinks and lies more closely and wrinkle-free against the encased sausage meat, the volume of which had been previously reduced by cooling. This "after-shrinking" procedure is a step in the manufacture of many prior art plastic casings, but was not required in the earlier manufacturing process for cellulose casings.
Orientation of multilayer films.
Orientation is a process where molecules are ordered by becoming aligned in the direction of an orienting force. Stretching after extrusion is a conventional technique to orient films. The stretching may be either in one direction resulting in a film that is uniaxially oriented, or the stretching may be in two directions, giving a product that is biaxially oriented.
Shirring
A method in which a flexible tubular container of either natural or artificial material, is gathered into pleats about a core or mandrel, prior to stuffing with meat or other ground foodstuff.
| EVA | Ethylene vinyl acetate copolymer |
| EMAA | Ethylene methacrylic acid copolymer |
| HDPE | High density polyethylene |
| LDPE | Low density polyethylene |
| VLDPE | Very low density polyethylene |
THE SPECIFICATION
The Viskase application is directed at producing improved polyamide tubular films for use as sausage casings for processing and packaging cooked sausages, including water cooked or steam cooked sausages such as liver sausage and fleischwurst or cheese sausage. A number of different tubular films or casings of this type exist in the prior art and it is known that such products must need to perform well for many criteria:
"It is generally known that selection of films for packaging food products such as meat and cheese sausages includes consideration of one or more criteria such as cost, abrasion resistance, meat adhesion, dimensional uniformity and stability, stiffness, strength, printability, durability, oxygen and water barrier properties, stretchability, machinability, optical properties such as haze, gloss and freedom from streaks and gels, and safety for contact with food."
Pre-existing casings are described in the Viskase application as meeting some of these requirements better than others. For example, commercialised cellulose casings are described as having excellent oxygen and moisture barrier properties and excellent dimensional uniformity and stability but are expensive to prepare. Plastic casings are said to be cheaper to prepare, but there have been difficulties in manufacturing a plastic casing that does not have serious deficiencies in its performance. In particular, prior art plastic sausage casings have tended to be deficient in one or more of the following areas:
wrinkle free appearance in the encased sausage
meat adhesion/preventing deposits of material collecting in pockets under the casing
dimensional stability of the casing
additional/difficult processing steps/equipment relative to that needed for cellulose casings.
The Viskase food casing comprises at least three layers:
"In the present invention it is a fundamental concept that the inner and outer layers comprise polyamide and the core layer comprises a polyolefin and the multilayer film be heat shrinkable having a heat shrinkage value at 90°C of at least 10% in at least one direction (preferably in both machine and transverse directions). By utilizing a multilayer film, the present invention overcomes disadvantages in monolayer polyamide casings of the prior art which sacrifice one or more desired functions such as moisture or gas impermeability, dimensional stability, or wrinkle resistance or meat adhesion for other functions including those listed above as well as processability or ease of manufacture."
The inner polyamide layer is said to provide good machinability, and to facilitate passage of the casing over shirring mandrels or stuffing horns without the need for addition of antiblock additives, polymeric plasticizers, or slip agents to the anterior surface of the film. Selection of an appropriate type of polyamide allows this layer to adhere well to the meat without the need for other additives.
The core layer functions as a water vapour barrier, and provides the film with the suppleness and proper modulus for good shirrability and orientation and may also function to strongly adhere the outer layer to the inner layer.
The outer polyamide layer provides strength and acts as a gas barrier, particularly for oxygen. This outer layer is typically the thickest to provide support to the casing wall in order to withstand stuffing, cooking, handling pressures and abrasion.
Another important feature of the multilayer casing is that it shrinks during the heat treatment phase.
"The films of the present invention are biaxially stretched and oriented films. An important feature of the invention is that the inventive films have sufficient shrinkage values and shrink forces to produce a smooth wrinkle resistant casing able to closely conform to encased foodstuffs during heat processing, chilling, refrigeration and storage. ……"
Generally the casings are described as requiring shrinkage values of at least 10% shrinkage in at least one direction, preferably in both the machine direction and the transverse direction and to have sufficient shrink force to ensure good conformation of the casing to enclosed foodstuffs.
Specific embodiments of the Viskase casing are also described which feature shrinkage values of over 20% at 90°C in both the transverse and machine directions. These embodiments also feature a core layer which consists essentially of a blend of either VLPDE or EVA, with EMAA.
CLAIMS
The claims on file are the result of amendments filed 17 February 1999 and 6 April 1999 that were advertised as allowed 16 November 1999. However the opponent's evidence and to a considerable extent the opponent's submissions are directed against an earlier set of amended claims filed 26 August 1996 (the early amended claims). For this reason I have reproduced below the independent claims from both the current claims and the earlier amendments. I have also highlighted the differences between these two sets of claims.
| Early Amended Claims | Current Claims |
| 1. A tubular, biaxially stretched, heat shrinkable, multilayer film, food casing comprising three polymeric layers: a) an inner layer comprising a polyamide; (b) a core layer comprising at least 60% by weight of at least one polyolefin selected from the group of copolymers of ethylene with at least one C3-C10 a-olefin, VLDPE, LLDPE, copolymers of ethylene with an alkyl acrylate, LDPE, HDPE, and blends thereof; (c) an outer layer comprising a polyamide; wherein said core layer (b) is disposed between and directly adhered to said inner layer (a) and said outer layer (c), and said multilayer film has a shrinkage value of at least 20% in at least one direction at 90°C | 1. A tubular, biaxially stretched, heat shrinkable, multilayer film, food casing containing three polymeric layers: a) an inner layer comprising a polyamide; (b) a core layer comprising at least 60% by weight of at least one polyolefin comprising at least 50% by weight VLDPE (c) an outer layer comprising a polyamide; wherein said core layer (b) is disposed between and directly adhered to said inner layer (a) and said outer layer (c), and said multilayer film has a shrinkage value of at least 20% in at least one direction at 90°C |
| 28. A tubular, biaxially stretched, heat shrinkable multilayer film food casing comprising: (a) an inner layer comprising a polyamide; (b) a core layer comprising at least 60% by weight of a very low density polyethylene (VLDPE) copolymer of ethylene and at least one C4-C8 alpha-olefin, said copolymer having a density less than 0.915 g/cm3 and a melt index less than 2 dg/min.; and (c) an outer layer comprising a polyamide; wherein said core layer (b) is disposed between inner layer (a) and outer layer (c), and said multilayer film has a shrinkage value of at least 10% in at least one direction at 90°C. | 27. A tubular, biaxially stretched, heat shrinkable multilayer film food casing comprising: (a) an inner layer comprising a polyamide; (b) a core layer comprising at least 60% by weight of a very low density polyethylene (VLDPE) copolymer of ethylene and at least one C4-C8 alpha-olefin, said copolymer having a density less than 0.915 g/cm3 and a melt index less than 2 dg/min.; and (c) an outer layer comprising a polyamide; wherein said core layer (b) is disposed between inner layer (a) and outer layer (c), and said multilayer film has a shrinkage value of at least 15% in at least one direction at 90°C. |
| 32. A continuous process for making tubular, biaxially stretched, heat shrinkable, multilayer thermoplastic food casing comprising: (a) coextruding a melt plastified multilayer thermoplastic tube having an exterior surface and an interior surface through an annular dye wherein said tube comprises an inner polyamide layer and an outer polyamide layer with a core layer between said inner and outer layers of at least one polyolefin; (b) cooling said coextruded tube below the melting point of each layer by applying water to the exterior surface of said tube; (c) transferring said cooled tube to an orientation zone wherein said tube is reheated to a temperature below the melting point of each layer followed by a cooling where a fluid mass is admitted to the interior of said tube thereby causing said tube to stretch circumferentially about the entrapped fluid mass and simultaneous with said circumferential stretching said tube is stretched in a direction perpendicular thereto to produce a biaxially stretched tubular film; and (d) annealing said biaxially stretched film at elevated temperature to dimensionally stabilize said film thereby producing a multilayer film having a shrinkage value at 90°C of at least 20% or higher in at least one direction. | 31. A continuous process for making tubular, biaxially stretched, heat shrinkable, multilayer thermoplastic food casing comprising: (a) coextruding a melt plastified multilayer thermoplastic tube having an exterior surface and an interior surface through an annular dye wherein said tube comprises an inner polyamide layer and an outer polyamide layer with a core layer between said inner and outer layers of at least 60% by weight of at least one polyolefin comprising at least 50% VLDPE; (b) cooling said coextruded tube below the melting point of each layer by applying water to the exterior surface of said tube; (c) transferring said cooled tube to an orientation zone wherein said tube is reheated to a temperature below the melting point of each layer followed by a cooling where a fluid mass is admitted to the interior of said tube thereby causing said tube to stretch circumferentially about the entrapped fluid mass and simultaneous with said circumferential stretching said tube is stretched in a direction perpendicular thereto to produce a biaxially stretched tubular film; and (d) annealing said biaxially stretched film at elevated temperature to dimensionally stabilize said film thereby producing a multilayer film having a shrinkage value at 90°C of at least 20% in at least one direction. |
As a result of these changes all independent claims now require the core layer to comprise a proportion of VLDPE. Claim 27 differs from its earlier version (claim 28) because the multilayer film claimed now has a shrinkage value of at least 15% in at least one direction at 90°C rather than 10%.
EVIDENCE
The evidence filed in support of the opposition consists of:
A statutory declaration by Dr John Kingsford Haken* dated 10 November 1997 together with Exhibits JKH-1 to JKH-7
A statutory declaration dated 9 September 1997 by Jill Newton together with exhibit JN-1
A statutory declaration by Joachim R Buchner dated 9 September 1997 together with exhibits JRB-1 and JRB-2 and JRB-3
A statutory declaration by Professor Robert A Shanks* dated 10 November 1997 together with exhibit RAS-1
A statutory declaration by John David O'Connor dated 29 August 1997 together with exhibits JDOC-1 to JDOC-39
The evidence filed in answer to the opposition consists of:
A statutory declaration by Stephen James Vicik* dated 19 November 1998 together with exhibits SJV-1, SJV-2, SVJ-3, SVJ-4
A statutory declaration by David Henry Solomon* dated 21 December 1998 together with exhibits DHS-1, DHS-2 and DHS-3
A statutory declaration Richard Hiram Baddeley dated 10 August 1998 with Exhibits RHB-1 to RHB-3
The evidence filed in reply:
No evidence was filed in reply.
*Technical evidence on the art and/or the Viskase invention.
SUBMISSIONS
Submissions by both parties will be referred to where relevant in the decision.
DECISION
Against the claims now on file, the sole ground on which the opponent is now arguing the claims should be found invalid is manner of new manufacture.
"The pending claims of the opposed application are, by reason of absence of the necessary quality of inventiveness, not a manner of new manufacture for the purpose of the Statute of Monopolies."
The opponent's submissions on this issue refer me to the discussion of prior art in the Viskase application, and in particular, what is said there about the contents of European Patent Document No 467,039 (EP467039) by Hoechst AG. EP 467039 (and the equivalent United States patent) were filed as part of the evidence in support and have been specifically addressed by the applicant in their written submissions on the grounds of novelty, and inventive step.
I consider that the inventiveness issue raised by the opponent, is essentially whether the claims of the Viskase application are new or inventive over the disclosure of EP467039. I consider this inventiveness is more appropriately assessed based on the complete document rather than the partial disclosure of EP467039 provided in the Viskase application. For this reason I would prefer to consider whether the Viskase claims are novel and inventive over EP467039 before dealing with any remaining issues under manner of new manufacture.
An immediate difficulty with this course of action is that EP467039 is written in German. A full English translation was not provided in the evidence from the opponent. Instead the opponent filed an English language family equivalent US5185189 (JRB-2). US5185189 is published after the priority date of the Viskase application and is a not prior publication, and ordinarily would not be of relevance in this opposition.
However the circumstances in this case are unusual. The expert evidence given by each side refers to, and appears directed at US5185189. Dr Haken on the opponent's side refers to US5185189 as corresponding with EP467039 and he directs his discussion to the text of "Hoechst (US)". Mr Vicik on the applicant's side also refers to "Hoechst (US)" as the particularised citation and directs his comments to the text of this document. Furthermore the opponent's evidence includes a declaration by German/English translator Mr Joachim Buchner in which the two documents are compared. This comparison outlines the common disclosure and details the minor differences between these two patents. Finally there is a translation by Mr Buchner of the claims of EP467039 (JRB-3).
Taking all of this into account, I believe it is reasonable for me to treat the description of US 5185189 (excluding the claims) as essentially providing an English translation of the description of EP467039. Subject to the differences identified by Mr Buchner, I will treat US5185189 in this manner throughout this decision.
Novelty
EP 467039 discloses a multilayer, polyamide based food casing of low oxygen permeability suitable for use with liverwurst sausage meat. A comparison of the features present in the two broadest claims of the Viskase application with those features explicitly mentioned in the casing of EP467039 is provided in the following table:
| FEATURE | Claim 1 | Claim 27 | EP 467039 |
| A tubular, biaxially stretched, heat shrinkable, multilayer film, food casing comprising: | Y | Y | Y |
| An inner layer comprising a polyamide | Y | Y | Y |
| A core layer comprising at least 60% of at least one polyolefin | Y | Y | Y |
A core polyolefin comprising VLDPE | Y | Y | ? (homopolymer of polyethylene) |
| Where the VLPDE copolymer has a density less than 0.915 g/cm3 and melt index less than 2dg/min | N | Y | N |
| An outer layer comprising polyamide | Y | Y | Y |
| Where the multilayer film has a shrinkage value of 15% (or higher) in one direction at 90°C | Y | Y | ? (Shrinkage values less than 20%) |
In Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977)137 CLR 228 at 235, Aicken J said:
“The basic test for anticipation of 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 was valid, constitute an infringement.”
In Rodi & Weinenberger A.G v. Henry Showell Ltd [1969] 12 RPC 367 at 384, per Lord Hodson.
"for it is only where there are differences in inessentials, while the alleged infringement possesses all the essential features or integers of the claim, that there will be infringement."
No argument has been raised that any of the features are inessential and it is my assessment that all the features in the independent claims (at least) are essential. Therefore, the question before me, is whether the citation discloses a casing with all the features of any of the claims. The features of the broadest claims not explicitly disclosed in the citation are the particular core layer composition and the required shrink or shrinkage values.
In EP467039 shrinkage values are only discussed in terms of an optional heat setting treatment. Following biaxial stretching it is stated that “dimensional stability” can be improved by partially or completely heat setting the stretched casing. I do not possess a precise definition of "dimensional stability", but the Viskase specification describes a lack of dimensional stability in the casing of prior patent US 4303711 as being associated with deformation and non uniform appearance. The passage on heat shrinkage values in EP467039 was as follows:
“As a result of heat setting, the shrink of the film at temperatures up to about 90°C is relatively low, ie a shrink of less than 20%, in particular of less than 15%, is measured both in the longitudinal direction and in the transverse direction”
Mr Vicik's, Professor Shank's and Professor Solomon’s evidence support the view that the heat setting step reduces the shrink values of the casing. The use of the heat setting step in both examples and the desirability of dimensional stability persuade me that the skilled worker would tend to use this option. But, in the absence of the heat setting step, would the shrink values of the resultant casing necessarily be above 15% or above 20% at 90°C as required in the claims of the Viskase application?
Dr Haken asserts in the absence of heat setting the considerable stretching required of the tubing in the examples would inevitably result in shrinkage values of at least 20%. Mr Vicik, on the other hand, disagrees stating that on the information provided, it is not possible to determine what the shrinkage values would be prior to heat setting and in addition that the surface area stretching was lower in EP467039 than in the Viskase application.
In considering the evidence on this matter, I have regard to the fact that while Dr Haken was Associate Professor in the Department of Polymer Science at the University of NSW for 16 years, and although he has extensive knowledge of the relevant literature, he concedes that he has had little practical experience with coextruded films. Mr Vicik, on the other hand, appears to have a great deal of practical expertise on the properties of multilayer casings. Of course, as the inventor he is an interested party. Professor Solomon appears to have only considered the casings when heat treated. Professor Shanks says nothing of significance on this matter. I consider the expert evidence of Mr Vicik to be more persuasive on this point than that of Dr Haken. I therefore consider there is not enough evidence to conclude whether or not the casings will have shrinkage values greater than 15% in the absence of a heat setting step.
I conclude, consistent with my reading of EP467039, that this document does not teach the manufacture of casings with shrink values greater than 15% (or, relevantly for claim 1 of the Viskase application, greater than 20%). The teaching of EP467039 would lead the skilled worker to adopt the heat setting step to produce casings with low shrinkage values, most preferably less than 15%.
In EP467039 the function of the core layer is described as providing a substantially impermeable barrier to water and water vapour. This function can be achieved using a variety of polyolefins:
The intermediate layer consists of one or more polyolefin compounds and an agent by which the adhesion between two polyamide layers and the intermediate polyolefin layer is improved……..
In general, the polyolefin of the central layer is a homopolymer of ethylene or propylene or a copolymer of linear alpha-olefines having 2-8 carbon atoms or a blend of several of these polymers. Suitable copolymers include C2/C3 copolymers and C3/C4 copolymers and also C2/C3/C4 terpolymers. A mixture comprising C3/C4 copolymer and C2/C3/C4 terpolymer is an exemplary suitable blend.
The two examples disclose heat set multilayer films having core layers comprising 80% HDPE.
The term "homopolymer of ethylene" broadly discloses polyethylene in a general sense and, in my opinion, also envisages different forms of polyethylene such as VLPDE, LDPE, HDPE etc.
I also accept the evidence of the Professor Solomon that different forms of polyethylene have very different properties. In the Viskase application the choice of VLPDE is linked in part to the achievement of good shrinkage properties:
"[VLDPE] excels in providing a desirable combination of shrink, shrink force, modulus and moisture barrier properties." (page 34)
Mr Vicik concurs with this and states that the form of polyethylene used in the examples of EP467039 is less suitable for applications requiring high shrinkage values:
"Also, HDPE, which is a high density material is not particularly suited to producing high shrinkage films at 90°C whereas the examples of the opposed patent used VLDPE which is a very low density material especially suited to the production of high shrinkage values"
Dr Haken refers to the "stiffness" of HDPE in his evidence:
"Like LDPE, it [HDPE] can readily be converted to film, sheet or containers. It is widely used (about 1.5 billion lbs/yr in the US) for packaging film and for applications such as molded bottles, jars, and vials where the need for greater strength and stiffness offsets its slightly higher cost (about 20% greater than LDPE) and lower clarity."
While discussing the examples in EP467039, Dr Haken indicates that considerable stretching results in high shrinkage values. Although not directed to this point, the evidence of Dr Haken, when taken together with the other evidence, is consistent with the view that HDPE is not as suited for achievement of high stretch and high shrinkage values as VLDPE.
In summary EP467039 describes in broad terms a range of polyolefins as being suitable for the core layer. The document teaches that low shrinkage values are preferred in order to achieve dimensional stability in the encased sausages. The examples use HDPE in the core layer and I accept that HDPE is a form of polyethylene less suited for production of casings with high shrinkage values.
There are no “clear and unmistakable directions" in the citation for the skilled worker to make a casing with a core layer comprising VLDPE and such high shrink values and in fact the indications are, that EP467039 teaches away from doing this.
I therefore find that all claims of the Viskase application are novel over EP467039.
Inventive Step
In order to assess the claims of the Viskase application for inventive step, under the 1990 Patents Act I need to determine:
the relevant art
the person skilled in that art
whether the claimed invention is obvious at the priority date of the claims to the worker skilled in the art on the basis of common general knowledge alone or in combination with a single disclosure.
The claimed invention is defined generally as a polymeric food casing, but the specification is concerned entirely with polymeric casings for sausages. The relevant art relates to polymeric films for encasing food.
In my view (which, in this instance, accords with the applicant's submissions) the skilled worker in the art would be an individual or group having expertise in the development of plastic multilayer products and knowledge of requirements for food casings.
There is no need in this instance to outlay the entire body of common general knowledge possessed by these skilled workers. From the evidence before me, I consider that their common general knowledge at the relevant date would include knowledge of a number of synthetic food casings, the general processes of manufacturing them, and the polymers used in the Viskase specification. While not a critical issue in this decision, I do not consider that the patent EP467039 has been shown to be common general knowledge in Australia at the priority date of the Viskase application. Relevant to forming this conclusion, is that none of the Australian based experts (Dr Haken, Professor Solomon or Professor Shanks) indicated that they had been aware of the document prior to being involved in the opposition proceedings.
The Viskase application summarises the inventor's view of the state of the art at the priority date:
"Prior art fiber reinforced cellulose casings coated with moisture barrier coatings perform well in processing water/steam cooked sausages such as fleischwurst and liver sausage. However the high cost of manufacture of such casings has led casing manufacturers to search for less expensive alternatives. Thermoplastic films of various compositions have been suggested and some have found varying degrees of success in various segments of the market. Thermoplastic sheet film has been made into a tube by seaming, but this is a difficult process which produces a casing having a seamed area which may undesirably differ in appearance and performance relative to an unseamed casing.
Seamless tubular thermoplastic casings have been made which overcome the objections to seamed casings. Various materials have been employed, but materials containing chlorinated polymers have been objected to for environmental reasons among others. Seamless polyamide casings have been made of blown film, however these casings tend to have poor performance with respect to wrinkling, uniformity of diameter, and dimensional stability. Seamless biaxially oriented multilayer films have been also made, however, such films have been difficult to produce requiring special blend formulations and structures or complicated equipment and procedures."
From the discussion of the prior art, the problem faced by the person skilled in the art is to discover a less expensive process for producing a multilayer thermoplastic casing that can still meet the needs for sausages including fleischwurst or liver sausage. A suitable food casing of the invention should feature good moisture barrier properties, low oxygen permeability, a tight fitting casing having few or no wrinkles, and good dimensional uniformity and stability, as well as meet other conventional requirements of sausage casings. An aspect of this or an additional problem may be a need to devise an improved method of manufacturing biaxially stretched multilayer casings.
Although the casings of claims 1-30 may be suited to be manufactured by the method of claims 31-36, it is not suggested in the specification or submitted in the evidence before me, that only these methods are suitable for this purpose. Therefore in considering the inventiveness of the casing as claimed in claims 1-30 it is not necessary that I do so only in the context of the method of claims 31-36.
There is no evidence on hand that suggests to me that the skilled worker in Australia at the relevant date would have developed a casing within the scope of the claims of the Viskase application on the basis of common general knowledge alone.
Where an assertion of a lack of inventive step relies upon information in a document not shown to be common general knowledge, then S.7(3) of the 1990 Patents Act requires that information to be such that the skilled person could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area. Professor Solomon has argued that EP467039 addresses a different problem and it can not be assumed that this document would be found by the skilled worker seeking to solve the Viskase problem.
EP467039 is concerned with producing a multilayer, polyamide based food casing of low oxygen permeability, which does not wrinkle and is suitable for use with liverwurst sausage meat. Relevant to the issue of reducing costs, the document teaches the manufacture of thermoplastic casings rather than the expensive cellulose casings and the avoidance of what is described as an expensive cooling step. Based on the similarities in the subject matter and the problem faced, I conclude this document would be likely to be found and considered relevant by a person searching for a solution to the problem addressed by the Viskase application.
I have already noted that the Viskase casing is quite similar in composition to the casing of EP467039. There are also many similarities in the advantages that the two applications describe as distinguishing their casings from the prior art as can be seen in the following table:
| PROPERTY | VISKASE CASING | EP467039 CASING |
| No wrinkling on stuffing or storage | Y | Y |
| Requires an "after shrinking" step | N | N (not cited as an advantage) |
| Low oxygen transmission and suitable for storing liverwurst meats | Y | Y |
| Little or no moisture loss during cooking or storage | Y | Y |
| Layers do not separate on cutting | Y | Y |
| Dimensionally stable | Y | Y |
| Good adhesion to meat without the use of starch based additives or treatment of electron beam irradiation or corona discharge | Y | Y |
| Shirring without antiblocking agents | Y | Y |
These similar advantages raise the issue of whether the Viskase casing can be viewed as the casing disclosed in EP467039 subject to routine variations or improvements. This issue was considered in Winner & Anor v Ammar Holdings Pty Ltd, (1993) AIPC 90-971 where at page 39,248 it was said:
"Notwithstanding that the inventive step may lie in the choice and management of integers in a combination patent (Wellcome Foundation at 281), where one starts with a known article or thing and merely substitutes or adds a known device or means to facilitate the better use of the thing, there is a risk of want of inventive step unless the combination is substantially a new thing" (May v. Higgins (1916) 21 CLR 119 at 121"
A difference that may be significant in the context of the problem addressed by the two applications is the use of the shrinkage properties. In the Viskase application the shrinkage properties are said to be important in preventing wrinkle formation:
"An important feature of the present invention is that the inventive films have sufficient shrinkage values and shrink forces to produce smooth wrinkle resistant casings able to closely conform to encased food stuffs during heat processing, chilling refrigeration and storage"
Even though the Viskase application indicates in a number of places that a shrinkage value of 10% at 90°C is sufficient, the preferred shrinkage values are stated to be at least 15-20% (i.e. see p14 lines 18-19). Further support for high shrinkage values is given later where the specification states;
"In one embodiment of the invention casings have a shrinkage value at 90°C of at least 20% or higher and/or a shrink force at 90°C of at least 30 Kg per cm, in at least one and preferably both the M.D. and T.D. directions to provide wrinkle resistance." (p35)
Subsequently the Viskase application features examples (Table A, and page 58) describing casings with shrinkage values in excess of 30% at 90°C in both the transverse and machine directions. These casings are described as strong supple and soft, with shrinkage and shrink force values indicating that any encased sausages would have a non-wrinkled appearance.
For these reasons I conclude the teaching in the Viskase application is to produce casings with high shrinkage values, in order to produce wrinkle resistant casings. Earlier I found that the teaching of EP467039 is to use the heat setting step to produce casings with low shrinkage values, preferably less than 15% in order to achieve dimensional stability. It is not apparent, from the evidence before me, what role the shrinkage values have in minimising wrinkles in EP467039. What I can conclude from what EP467039 describes, is that the properties of the outer polyamide layer are important in causing the casing to shrink during cooling and storage to prevent creases:
"During scalding or boiling of sausages, the outer layer absorbs water. During the subsequent cooling and storing of the sausages, this water is set free. This freeing of water from the outer layer causes the outer layer to shrink during drying, and the casing surrounds the cooled down sausage more tightly and without creases."
Mr Vicik submits that nylon casings having low or no shrinkage values rely upon elastic properties rather than shrink properties to promote a wrinkle-free appearance. It appears likely to me that the Viskase application and EP467039 are employing different philosophies to control wrinkles and I cannot assume this would lead to the same results. Consistent with this different approach are the differences in the core layer composition. The Viskase application teaches the use of VLPDE as a preferred material for the core layer because it favours wrinkle resistance as well as to secure other favourable properties;
"VLDPEs and ethylene ester copolymers beneficially facilitate orientation and provide good adhesion and moisture properties as well as shrink and shrink force properties that promote wrinkle resistance. Additionally, these polymers provide suppleness and proper modulus to enable the inventive tubular films to be easily shirred and deshirred without undesirable breakage." (pp.31-32)
In contrast, as discussed earlier, in EP467039 the core polyolefin functions to make the casing impermeable to water and water vapour. The choice of HDPE in the examples suggests that forms of polyethylene that favour low shrinkage properties are preferred. Given the different approach in using shrinkage values to control wrinkles and the benefits that VLDPE provides to ease of manufacture of the casings, I conclude that the differences in the features between the casings are significant and the two casings are not equivalent.
It is not apparent that a skilled worker would determine that the casing of EP467039 was deficient in wrinkle resistance or ease of production and that there was still some problem still to be solved.
"It must, in my opinion, be shown to be worth trying in order to solve some recognised problem or meet some recognised need. The uninventive expert (see [1972] RPC page 355 line 5) should not be supposed to be attempting to discover something new, that is, to be striving for inventiveness. Having been shown what was disclosed by the prior art, he must be supposed to be attempting to solve some problem or fulfil some need which has not been resolved or satisfied by the prior art but which appears to his uninventive mind to be possibly capable of solution or satisfaction by taking the step or doing the thing under consideration. This, it seems to me, must involve the uninventive but skilled man having a particular problem or need in mind. If on carrying out this test he finds that the new step has the sort of consequence he had hoped but in an unexpectedly high degree, this would or might not mean that the new step was inventive or other than obvious; it might merely mean that a new and obvious step has solved the problem or met the need unexpectedly well. The question would, I think be one of degree. If on the other hand, the new step produces some unexpected result, product or an improvement or benefit of an unexpected kind it may well be held to be invention, the association of the new step with its result not having been obvious." Beecham Group Ltd's (Amoxycillin) Application [1980] RPC 261
However it is salient that in the Viskase application the method of manufacturing the casing of EP467039 is identified as having problems:
"The above mentioned EP Document No. 467,039 discloses preparation of its casing by reference to EP 305 874 (which corresponds to U.S. Patent 4,886,634), which discloses a rather complicated apparatus employing e.g. a vacuum tank and probe pipe with a sealing element. Also blending polyester with the polyamide is suggested to facilitate biaxial stretching. Disadvantageously, orientation of seamless tubes of nylon by biaxial stretching is difficult."
But even if the hypothetical skilled worker in Australia reached the same conclusion, no evidence or argument before me suggests that in seeking to solve this problem they would modify the polyolefin composition of the core layer and increase the shrinkage values of the casing. The approach used by the applicant appears to me to be inventive.
All claims of the Viskase application therefore possess an inventive step.
Manner of New Manufacture
Analogous Use
The opponent has asserted that the application is not for a manner of new manufacture as it is merely an analogous use of a known material citing Commissioner of Patents v Microcell Ltd (1959) 102 CLR 232 at 251:
"The quality of inventiveness is not satisfied in a case where the claims are for a new use of a known material in the manufacture of known articles for a purpose for which the materials known properties make it suitable. Such a claim cannot be subject matter for a patent. The position cannot be affected either by the fact that nobody thought of doing the thing before, or by the fact that, when somebody did think of doing it, it was found to be a good thing to do."
The only basis the opponent provides to sustain this argument is a short statement in the evidence provided by Professor Solomon:
"I agree with Professor Shanks that the polymers used by Viskase and in broad terms the process of manufacture were known."
If the 'known article' is the casing of EP467039 and the 'known material' is VLDPE, then this issue of inventiveness has already been considered under inventive step. In any case the invention is for a combination, not an article made from a single material as was the case in Microcell (supra).
"It is accepted as sound law that a mere placing side by side of old integers so that each performs its own proper function independently of any of the others is not a patentable combination, but that where the old integers when placed together have some working inter-relation producing a new or improved result then there is patentable subject-matter in the idea of the working inter-relation brought about by the collocation of the integers." British Celanese Ltd v Courtaulds Ltd (1935) 52 RPC 171 at 193.
It is clear from the description that the applicant has described the invention as a new combination with new advantages, rather than an analogous use of a known material like plastic. Accordingly I reject the opponent's argument on this point.
Lack of invention apparent on the face of the specification
The opponents’ other argument is that there is a lack of inventiveness apparent from what the Viskase specification reveals, in other words the opposed specification fails the threshold test for inventiveness described in NV Philips Gloeilampenfabrieken v Mirabella International Pty Ltd (1995) .183 CLR 655. This 'threshold test' for inventiveness was recently considered in Bristol-Myers Squibb Co v F H Faulding & Co Ltd [2000] FCA 316:
"In our view …. Philips stands for the proposition (as a matter of construction of the 1990 Act) that if, on the basis of what was known, as revealed on the face of the specification, the invention claimed was obvious or did not involve an inventive step - that is, would be obvious to the hypothetical non-inventive and unimaginative skilled worker in the field (Minnesota at 260 per Barwick CJ) - then the threshold requirement of inventiveness is not met. "
The opponent's submissions on this matter rely in substance on the evidence given by Dr Haken in his declaration of 10 November 1997 filed during evidence in support.
"...it is apparent on the face of the specification that the quality of inventiveness is absent. See paragraph 11.2 of Dr Haken's declaration. Dr Haken is at a loss to understand how the nature of the film and the method of its manufacture as claimed is in any way inventive, particularly having read the subject matter under "Background of the invention" on pages 1-13 of the opposed application!"
The context of Dr Haken's views are given in paragraph 11.2 of the declaration where he states:
"I am further at a loss to understand how the nature of the film and its method of manufacture which is claimed in the Viskase Application is any way inventive, particularly having read the subject matter under "Background of the invention" on pages 1-13 of the Viskase Application. Certainly none of the features of either the casing or the process claimed in the amended claims both separately and in combination were new as at the Priority Date."
I particularly note at page 7, line 25 to page 9, line 2 of the Viskase Application, the reference to European Patent Document No 467,039, which I am informed is the Hoechst Application. While it is stated at page 7, line 25 of the Specification that there is no admission that European Patent document constitutes prior art, the discussion in relation to the Hoechst Application proceeds in my view to describe the multilayer casing described therein in terms of the invention. In any event for the reasons stated in paragraphs 4.1 to 4.43 above I am strongly of the view that the Invention is not new in the light of the Hoechst Application."
The opponent appears to rely on the proposition that the discussion of EP467039 in the Viskase application is information that the specification reveals as known. In Bristol Myers(supra), at paragraph 30, some consideration was given as to what knowledge could be considered as known, as revealed on the face of the specification.
"Some elaboration, however, is required in relation to what the specification reveals as "known". If a patent specification, lodged in Australia, refers to information derived from a number of prior publications referred to in the specification or, generally, to matters which are known, in our view the Court - or the Commissioner - would ordinarily proceed upon the basis that the knowledge thus described is, in the language of s 7(2) of the 1990 Act, part of "the common general knowledge as it existed in the patent area". In other words, what is disclosed in such terms may be taken as an admission to that effect. In substance, we think, that is what happened, both in Microcell and Philips. "
I consider that the passage should be read as implying, that to be revealed as known, there needs to be sufficient reason to conclude that particular pieces of information referred to in a specification are being revealed as part of the common general knowledge of the field. Similar views have been expressed in previous decisions of the Commissioner, see for example; Centaur Nickel Pty Ltd v QNI LTD [2000] APO 65 (31 October 2000).
If this interpretation is correct then the allegation of a lack of inventiveness on the face of the document must fail. The Viskase document does not provide any such indication that the casing described in EP467039 can be considered part of the common general knowledge in the patent area. Furthermore the Australian based technical experts gave no indication in their evidence that they had prior knowledge of this patent.
But even if I am mistaken in the law for manner of new manufacture and all details of patents or other public knowledge disclosed in the Viskase application should be assumed to be common general knowledge in Australia or at least as 'known' in some relevant sense, I do not see that this would assist the case that the opponent has put before me. I have already found that the claims of the Viskase application are inventive over EP467039. I have read the discussion of prior art in the Viskase application and I consider that it does not make obvious the claimed invention.
I find that all claims of the Viskase application are for a manner of new manufacture.
Section 40
None of the Section 40 matters raised in the statement of grounds and particulars were pursued in the opponent's submissions and none of these matters appear likely to render the patent invalid and so I will not consider them further in this decision.
CONCLUSION
I have found that the opposition fails on the ground of manner of manufacture and that the application accords with Section 40 and is novel and inventive when compared with EP467039.
Accordingly I direct the application be sealed after 30 days from the date of this decision. 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
The opponent has argued that even if they do not succeed, they should be awarded costs in recognition of the amendments that have taken place since the opposition began. These amendments have resulted in the increase in the minimum shrinkage values of the claimed casing and restricting the claimed core olefin layer so that it must contain VLDPE. These are the features that I found have distinguished the Viskase casing from that disclosed by EP467039. I think that in these circumstances, it is appropriate that I award costs against the applicant up to the date of allowance of the amendments filed 17 February 1999 and award costs against the opponent from that point onwards.
Ross Osborne
Delegate of the Commissioner of Patents
Patent attorneys for the applicant : Watermark Patent & trademark Attorneys
Patent attorneys for the opponent : Spruson & Ferguson
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