Nova Chemicals Corporation v. Dow Chemical Company

Nova Chemicals Corporation v. Dow Chemical Company
Court (s) Database
Federal Court of Appeal Decisions
Date
2016-09-06
Neutral citation
2016 FCA 216
File numbers
A-379-14
Decision Content
Date: 20160906
Docket: A-379-14
Citation: 2016 FCA 216
CORAM:
WEBB J.A.
BOIVIN J.A.
DE MONTIGNY J.A.
BETWEEN:
NOVA CHEMICALS CORPORATION
Appellant
and
THE DOW CHEMICAL COMPANY,
DOW GLOBAL TECHNOLOGIES INC. AND DOW CHEMICAL CANADA ULC
Respondents
Heard at Toronto, Ontario, on December 7 and 8, 2015.
Judgment delivered at Ottawa, Ontario, on September 6, 2016.
REASONS FOR JUDGMENT BY:
DE MONTIGNY J.A.
CONCURRED IN BY:
WEBB J.A.
BOIVIN J.A.
Date: 20160906
Docket: A-379-14
Citation: 2016 FCA 216
CORAM:
WEBB J.A.
BOIVIN J.A.
DE MONTIGNY J.A.
BETWEEN:
NOVA CHEMICALS CORPORATION
Appellant
and
THE DOW CHEMICAL COMPANY,
DOW GLOBAL TECHNOLOGIES INC. AND DOW CHEMICAL CANADA ULC
Respondents
REASONS FOR JUDGMENT
DE MONTIGNY J.A.
[1] This is an appeal from a decision of Justice O’Keefe (the Judge) granting an action for patent infringement brought by the Dow Chemical Company, its subsidiary Dow Global Technologies Inc. and its licensee Dow Chemical Canada ULC (collectively Dow, or the respondents) against the Nova Chemicals Corporation (Nova or the appellant) in respect of its product SURPASS. The parties are both manufacturers of polyethylene film-grade copolymers for use in, amongst other things, packaging applications. The Dow Chemical Company is the owner of Canadian Patent 2,160,705 (the ‘705 Patent) for “Fabricated Articles Made from Ethylene Polymer Blends”.
[2] The Judge confirmed the validity of the ‘705 Patent, which was challenged on the grounds of utility, over-claiming, anticipation, obviousness, double-patenting and insufficiency of the specification. The Judge also construed six disputed terms in the patent claims, which led him to conclude that Nova had infringed the patent. In coming to his conclusions, the Judge largely preferred Dow’s experts and fact witnesses over Nova’s own expert witnesses.
[3] Before this Court, Nova appeals all of the Judge’s findings regarding validity and also contests the construction of four terms in the ‘705 Patent, as well as the corresponding infringement findings. Having carefully considered the oral and written arguments of the parties, I am of the view that the appeal ought to be dismissed; the appellant has failed to demonstrate any error of law, and it is not the role of this Court to second-guess the Judge’s assessment of the evidence that was put to him.
I. The Patent at Issue [4] The ‘705 Patent was filed in Canada on April 19, 1994. It claims priority from US patent application US08/054,379 dated April 28, 1993. It was published on November 10, 1994, and expired on April 19, 2014.
[5] The patent is directed primarily to polyethylene used to make “film” products, i.e. sheets of plastic, like plastic garbage bags and food wrapping. Some film applications do not have demanding strength requirements, but others do. One solution for these demanding applications was to make thicker “films” so that they are stronger. That requires the use of more plastic, however, leading to higher costs and more waste when the plastic film is disposed of.
[6] The patent identifies the need to develop polymers that can be formed into thinner films with improved strength properties:
There is a continuing need to develop polymers which can be formed into fabricated articles having these combinations of properties (e.g., improved modulus, yield strength, impact strength and tear strength, preferably greater dart impact for a given yield strength in the c[a]se of films and greater IZOD impact for molded parts). The need is especially great for polymers which can be made into film which can also be down gauged without loss of strength properties, resulting in savings for film manufacturers and consumers, as well as protecting the environment by source reduction.
‘705 Patent, p. 1, lines 22-31
[7] The person skilled in the art (POSITA) would have appreciated that there was often a trade-off between film properties such as yield strength, impact strength, and toughness. The POSITA would also have known that there is a trade-off with polymer materials, including film, between strength and toughness. Efforts to modify a polymer material to improve strength often resulted in reduction of toughness, as mentioned in the ‘705 Patent:
Previous attempts were made to optimize film tensile strength and yield strength by blending various heterogeneous polymers together on theoretical basis. While such blends exhibited a synergistic response to increase the film yield strength, the film impact strength followed the rule of mixing, often resulting in a “destructive synergism” (i.e., the film impact strength was actually lower than film made from one of the two components used to make the blend).
‘705 Patent, p. 1, lines 10-17
[8] The claimed invention and Dow’s commercial embodiment of it (ELITE) allows for source reduction to make thicker films thinner, but just as strong. Whereas prior art efforts to create improved polymers and polymer blends were largely trial and error, Dr. Lai (one of the inventors) testified at trial that Dow’s researchers took a different approach to identify the optimal blend based on polymer density, molecular weight, and strain hardening (the latter being a property wherein a material becomes harder as it is stretched). This work is disclosed in the ‘705 Patent, including the creation of the slope of strain hardening coefficient (SHC) to identify polymers of interest. The ‘705 Patent describes the invention in the following terms:
Surprisingly, we have now discovered compositions useful in films and molded parts having synergistically enhanced physical properties, which compositions comprise a blend of at least one homogeneously branched ethylene/α-olefin interpolymer and at least one heterogeneously branched ethylene/α-olefin interpolymer.
In particular, formulated ethylene/α-olefin compositions have now been discovered to have improved physical and mechanical strength and are useful in making fabricated articles. Films made from these novel compositions exhibit surprisingly good impact and tensile properties, and an especially good combination of modulus yield, ultimate tensile, and toughness (e.g. dart impact).
‘705 Patent, p.1, line 32 to p. 2, line 6
[9] Each of the 46 claims of the ‘705 Patent is directed to a blend having at least these two components, with each component having certain requirements, depending on the particular claim. While the claims recite several limitations, the major disputes in the case revolve around just two of them. For Component A, the dispute is over the claim term “slope of strain hardening coefficient”. For Component B, the main dispute is over the claim term “heterogeneously branched”. All the asserted claims include these terms.
[10] Dow filed a Statement of Claim on December 9, 2010, alleging that Nova was infringing their ‘705 Patent. Nova counterclaimed on the grounds of invalidity and unjust enrichment, but eventually dropped its unjust enrichment claims. In its opening statement at trial, Dow restricted the litigation to only eight composition claims, being claims 11, 29, 30, 33, 35, 36, 41 and 42; Nova similarly restricted its invalidity counterclaim to these same claims. As a result, the Judge erred in holding that Claim 15 was valid and infringed; Dow dropped its allegations in relation to that claim, and reference to it in paragraph 1 of the Judgment should be deleted.
[11] The trial began on September 9, 2013 and lasted for 32 days. Nova called three expert witnesses (Dr. Charles Stanley Speed, Dr. Francis Mirabella and Dr. Mukerrem Cakmak) and three fact witnesses, while Dow called three expert witnesses (Dr. Joao Soares, Dr. Robert Young, and Dr. Christopher Scott) and one fact witness. The Judgment was released on May 7, 2014 and the Reasons for Judgment were issued on September 5, 2014. The Judge found that all the claims at issue were valid, and that Nova infringed these claims by manufacturing in Canada and distributing, offering for sale, selling or otherwise making available film-grade polymers under the name SURPASS.
II. Issues [12] Nova contends that the Judge made a number of reviewable errors. I believe these issues can be narrowed down as follows:
As for the validity of the ‘705 Patent:
1) Did the Judge err in deciding that there was no promise of synergistic utility?
2) Did the Judge err in finding that the invention was not obvious?
3) Did the Judge err in finding that the claims were not broader than the invention made or disclosed?
As for infringement:
4) Did the Judge err in inferring that SHC is determined using a load/elongation curve?
5) Did the Judge err in construing “heterogeneously branched”?
6) Did the Judge err in construing “comprising”?
7) Did the Judge err in deciding that the high density (HD) fraction was at least 5% by weight of the composition?
III. Analysis [13] There is no dispute between the parties as to the applicable standard of review. Pursuant to the decision of the Supreme Court in Housen v. Nikolaisen, 2002 SCC 33, [2002] 2 S.C.R. 235, the standard of review for findings of fact is palpable and overriding error, and correctness for errors of law. The standard is also palpable and overriding error for findings of mixed fact and law, unless there is an extricable question of law, which will be reviewed on a correctness standard.
[14] It is worth emphasizing at this stage that a trial judge is entitled to deference in its appreciation of the evidence, particularly the expert evidence that affects the construction of a patent. In particular, the judge is entitled to weigh the evidence and to prefer certain evidence. It is certainly not the role of an appeal court to retry the case or to second-guess the trial judge’s assessment of the factual record and of the evidence. An appellant will consequently bear a heavy burden on matters of fact. As this Court held in Canada v. South Yukon Forest Corporation, 2012 FCA 165 at para. 46, 431 N.R. 286, “it is not enough to pull at leaves and branches and leave the tree standing” when arguing palpable and overriding error; “[t]he entire tree must fall”.
[15] On the other hand, the construction of the patent is to be reviewed on the basis of correctness. As the Supreme Court has stated in Whirlpool Corp. v. Camco Inc., 2000 SCC 67 at para. 61, [2000] 2 S.C.R. 1067, “claims construction is a matter of law”. That being said, I share the concerns of my colleague Justice Stratas that it will often be difficult, if not unrealistic and artificial, to distinguish between those aspects of claim construction that flow from the trial judge’s assessment of expert evidence from the words of the claim themselves (see Cobalt Pharmaceuticals Company v. Bayer Inc., 2015 FCA 116 at paras. 16-24, [2015] F.C.J. No. 555). After all, the construction of a patent is heavily dependent on the evidence given by persons skilled in the art, and that evidence will bear heavily on the judge’s findings. For that reason, I accept (as I must) that the construction of a patent is a question of law to be reviewed on a standard of correctness, but trial judges are nevertheless entitled to some leeway as they are often in a much better position than appellate judges to understand the intricacies of the art underlying the invention disclosed in a patent.
1) Did the Judge err in deciding there was no promise of synergistic utility? [16] Section 2 of the Patent Act, R.S.C. 1985, c. P-4, defines an invention as “any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter”. As a result, a patent holder must be able to demonstrate the utility of the invention or to show that it could be soundly predicted at the time the patent was applied for (see Apotex Inc. v. Wellcome Foundation Ltd., 2002 SCC 77 at para. 46, [2002] 4 S.C.R. 153, cited by this Court in Apotex Inc. v. Sanofi Aventis, 2013 FCA 186 at para. 46, [2015] 2 F.C.R. 644 [Apotex & Sanofi FCA]). An inventor does not need to describe the utility of his/her invention, in which case a “mere scintilla” of utility will be sufficient. If, however, an inventor does make an explicit promise of a specific result, utility will have to meet that promise; it will be, in the words of the Supreme Court in Free World Trust v. Électro Santé Inc., 2000 SCC 66 at para. 51, [2000] 2 S.C.R. 1024, a “self-inflicted wound” (see also Apotex & Sanofi FCA at paras. 54 and 65-67).
[17] The Judge also clearly set out the process whereby the existence and scope of any promise is to be determined: 1) one must first look for the elevated promise or claimed utility in the claims of the patent; and 2) then consider any statement found elsewhere in the disclosure, which should be taken as “mere statement of advantage” unless the inventor “clearly and unequivocally” states that it is part of the promised utility of the invention (Reasons for Judgment, para. 183).
[18] This approach is broadly consistent with the most recent jurisprudence of this Court and of the Federal Court, and Nova did not challenge the soundness of the Judge’s reasons in this respect (see Apotex & Mylan v. Pfizer, 2014 FCA 250 at paras. 65-66 and 76, 465 N.R. 306 [Apotex & Mylan]; Fournier Pharma Inc. v. Canada, 2012 FC 741 at para. 126, [2012] F.C.J. No. 901; Bauer Hockey Corp. v. Easton Sports Canada Inc., 2010 FC 361 at para. 290, [2010] F.C.J. No. 431, aff’d 2011 FCA 83, 414 N.R. 69, quoting, at para. 182, H.G. Fox, Canadian Patent Law and Practice, 4th ed. (Toronto: Carswell, 1969) at pp. 152-154). The Judge’s task was therefore to construe the patent to determine if a POSITA would understand it to contain an explicit promise that the invention will achieve a specific result.
[19] There is some ambiguity as to what Nova considers to be the promise made by the patent. At trial, Nova relied on one of its experts, Dr. Speed, whose position was understood by the Judge to be that “all the blends contemplated by the Patent and every property of all the blends must exhibit a synergistically enhanced physical property” (see Reasons for Judgment, para. 186). It is true that on cross-examination, when pushed on that question, Dr. Speed answered that “at least some of those properties” would show particularly good performance (Cross-Examination of Dr. Speed, Appeal Book Vol. 19, Tab 355 at p. 18429). This is not, however, how Dr. Scott understood Dr. Speed’s expert report (see Expert Report of Dr. Scott, Appeal Book Vol. 35, p. 6033 at para. 78), and the Judge cannot be faulted for having read Dr. Speed’s report the same way Dr. Scott did.
[20] In its written closing submissions, counsel for Nova summarized the promise of the patent as being that “at least impact strength will be better than the rule of mixing when other properties like tensile strength, yield and modulus are surprisingly improved in the newly discovered compositions”. And on appeal, Nova framed the promise in a slightly different manner, speaking of compositions having “improved properties”, “impact and tensile properties at a level above the rule of mixing”, and “synergistically enhanced physical properties, surprisingly good tensile and impact properties, or any improvement in the properties” (see Memorandum of Fact and Law of Nova at paras. 28, 40 and 45). Needless to say, such variations in the formulation of the impugned promise detract from the requirement that the promise be specific and clear.
[21] Be that as it may, and however the alleged promise is interpreted, the main problem with Nova’s position is that it rests exclusively on the use of the words “synergistically enhanced properties” used on two occasions at page 1 of the patent, previously quoted in paragraphs 7 and 8 of these reasons.
[22] After quoting from both Dr. Speed’s and Dr. Scott’s expert reports, the Judge found that the inventors had not made an explicit promise of a specific result, and that the ‘705 Patent had rather been shown to be concerned with particular compositions that were useful. He came to that conclusion essentially for two reasons. First, he found no reference in the claims of the patent to an elevated promise of “synergistically enhanced physical properties”, nor to any specified level of improvement; in the Judge’s view, the claims simply speak of the compositions having improved properties. Second, he preferred Dr. Scott’s testimony over that of Dr. Speed, because the former addressed the patent as a whole, while the latter ignored the parenthesized words in the patent defining “destructive synergism” as well as the examples given in the patent.
[23] Nova challenges those findings on a number of bases. It asserts that the Judge gave too much weight to the presumption that a statement of utility found elsewhere than in the claims of the patent was a mere statement of advantage, and not a promise. I disagree. The Judge did not rely on such a presumption, and there was indeed no need to rely on that expediency.
[24] However one looks at the ‘705 Patent, two crucial facts stand out: there is not a single statement of utility in Dow’s claims, as acknowledged by Nova, and there is only one reference elsewhere in the specification to support an argument of enhanced utility. I agree with Dow that the Court should be wary of using a stray phrase on page 1 of the patent to define the promise of the patent. Such an approach would clearly be inconsistent with another presumption that an inventor should only be held to an elevated standard where a clear and unambiguous promise has been made. As this Court stated in Apotex & Mylan at paragraph 66, “[w]here the validity of a patent is challenged on the basis of an alleged unfulfilled promise, the patent will be construed in favour of the patentee where it can reasonably be read by the skilled person as excluding this promise”.
[25] The Judge did not make a palpable and overriding error in finding that the first reference to “destructive synergism” found in the second paragraph of page 1 of the patent does not relate to the construction put forward by Dr. Speed that the patent promises an elevated level of utility. This passage is clearly descriptive of prior attempts at blending various heterogeneous polymers and the trade-off problem encountered.
[26] As for the second reference to “destructive synergism” at page 1 of the patent (the only relevant one for the purpose of identifying an explicit promise of a specific result), I am also of the view that the Judge could properly find that it is far from sufficient to infer any specified level of improvement. It does not refer to any particular blends, to any particular properties or to any particular applications.
[27] It is worth noting that the expression “synergistically enhanced” is nowhere defined in the patent. This is no doubt an important clue as to the significance of those words, as one would have expected them to be defined somehow, if they were to be taken as an explicit promise of a specific result. Indeed, Nova faults the Judge for not having construed those terms, and for not having adopted the definition provided by Dr. Speed in his expert report and in his oral testimony.
[28] The common understanding of the “rule of mixing” is that the properties of a blend are comparable to, and predictable from, the weight average ratios of the component polymers. According to Dr. Speed, a “synergistic response” means that a blend property is higher than, and a “destructive synergism” is lower than, the rule of mixing. To borrow his own words:
A skilled person would understand “synergistically enhanced” to mean that a property of a blend is better than predicted by the rule of mixing and “destructive synergy” to mean the property is worse than predicted by the rule.
Expert Report of Dr. Speed, Appeal Book Vol. 43, Tab 300 at para. 100
[29] There are a number of problems with this interpretation, not the least of which being that it is inconsistent with the wording of the patent itself. In the parenthesis following the first use of the words “destructive synergism”, the meaning ascribed to that expression is rather that of a blend value that is lower than either of the two pure components used to make the blend. It is true, as pointed out by counsel for Nova, that Dr. Speed was cognizant of that definition; but he dismisses it in a footnote on the basis that a skilled person would not adopt this “literal meaning” (see Expert Report of Dr. Speed, Appeal Book Vol. 43, Tab 300, p. 9231, para. 115, footnote 2).
[30] Whatever the merits of the construction put forward by Dr. Speed, the Judge was entitled to prefer the testimony of Dr. Scott on that issue. The Judge quoted at length from Dr. Speed’s and Dr. Scott’s expert reports, and came to the conclusion that Dr. Scott considered the patent as a whole instead of focusing on two passages from the first page of the patent. In particular, Dr. Scott looked at the examples outlined at pages 16 to 26 of the patent, which show that the compositions defined by the claims have improved properties, as compared to the primary type of polymers previously used for film applications and the comparative heterogeneous polymer blends. In summing up these comparisons, the patent speaks at page 26 of “good combination” of properties, “improvements”, and “higher values”. According to Dr. Scott, this is not the hallmark of an explicit promise of specific results, but rather a statement that the compositions of the ‘705 Patent have improved on the prior art based polymers and polymer compositions (see also the first paragraph of page 2 of the patent, quoted at paragraph 8 of these reasons).
[31] Dr. Scott also testified that the terms “synergy” and “synergistic” are open to various definitions in the art and will take their colour from the context into which they are used. Dr. Speed’s analysis of “synergistic enhancement” (i.e. a property of a blend is better than predicted by the rule of mixing) is only one possible meaning, and according to Dr. Scott would usually be referred to as “positive deviation from the rule of mixing”. As a result of his underlying assumption that the patent is directed to his own definition of “synergistic enhancement”, Dr. Speed was led not only to disregard the parenthesis at the end of the second paragraph at page 1 of the patent, but also to mischaracterize the data from Table 3. The purpose of that Table was to compare blends of the invention with the film properties of a heterogeneously branched interpolymer equivalent, with comparable density and in some cases comparable melt index. Dr. Speed states that incorrect comparisons have been made because the examples in the patent are not directed at showing whether there is synergistic enhancement. However, the ‘705 Patent was not directed to such synergistic enhancement. The comparison is only meant to emphasize improvements in specific properties, not in all properties and for all blends.
[32] Such a reading is consistent with the trade-off problem alluded to in the patent, according to which prior efforts to improve one property of a polymer often resulted in another property being negatively affected. The objective would therefore be to achieve a good balance of properties, and to improve only those properties important to the particular use contemplated. It should also be noted that nowhere does the patent compare the properties of the inventive examples to the properties of the component polymers of a blend, as would be required to demonstrate synergistic enhancement as the term is defined by Dr. Speed; instead, the examples and the Tables in the patent are meant to compare the inventive examples with polymers having similar density and melt index (the two most important parameters in evaluating the mechanical properties of polymers).
[33] Dr. Scott’s construction of the patent was certainly as credible and cogent as that of Dr. Speed, and the Judge could certainly prefer his testimony over that of Dr. Speed. Moreover, Dr. Scott’s construction of the patent is consistent with that put forward by Dr. Soares, who is also of the view that there is no standard definition of the word “synergism”; in his Rebuttal Report, he stated that “[t]here is not a single ‘rule of mixing’ that applies to all properties of polyolefin blends and the 705 Patent makes no promise regarding such behaviour” (Rebuttal Report of Dr. Soares, Appeal Book Vol. 36, Tab 194, at para. 103). On cross-examination, he did not demur from that position (Cross-Examination of Dr. Soares, Appeal Book Vol. 22, Tab 362, pp. 19755 to 19758).
[34] As mentioned above, the Judge is entitled to deference when assessing the evidence, and this is true for expert evidence as much as for any other type of evidence: Bell Helicopter Textron Canada Limitée v. Eurocopter, société par actions simplifiée, 2013 FCA 219 at paras. 73-74, 449 N.R. 111; Corlac Inc. v. Weatherford Canada Inc., 2011 FCA 228 at para. 24, 422 N.R. 49; Mylan Pharmaceuticals ULC v. AstraZeneca Canada Inc., 2012 FCA 109 at para. 20, 432 N.R. 292; Wenzel Downhole Tools Ltd. v. National-Oilwell Canada Ltd., 2012 FCA 333 at para. 44, [2014] 2 F.C.R. 459; Zero Spill Systems (Int’l) v. Heide, 2015 FCA 115 at para. 43, [2015] F.C.J. No. 554. The Judge was clearly alive to the conflicting views of the experts with respect to the promise (or lack thereof) made by the inventors in the patent, and he provided reasons for preferring the interpretation given by Dow’s experts over that of Nova’s experts. Such a finding is unassailable.
[35] In a last-ditch effort to convince the Court that the ‘705 Patent must be read as identifying a specific promise that was described as being that “at least impact strength will be better than the rule of mixing when other properties like tensile strength, yield and modulus are surprisingly improved in the newly discovered compositions”, Nova submitted that the patent should be treated as a selection patent. For such a patent, it is necessary for the specification to define in clear terms the nature of the characteristic which the patentee alleges to be possessed by the selection for which he claims a monopoly (Apotex Inc. v. Sanofi-Synthelabo Canada Inc., 2008 SCC 61 at para. 114, [2008] 3 S.C.R. 265).
[36] The problem with this theory is that there is no evidence that this is how a skilled person would construe the patent. More importantly, the Judge found that the ‘705 Patent was neither taught nor anticipated by any of the two patents referenced by Nova. Since Nova has not appealed this finding, it has no basis to argue that the patent is a selection patent and therefore no basis to contend that an elevated promise of utility is required to support the patent.
[37] On the basis of the foregoing, I am therefore of the view that the Judge could find that the inventors did not make an explicit promise of a specific result, and that the patent did meet the test of a “mere scintilla” of utility. Nova has not seriously challenged that finding, and one of its own experts acknowledged that the invention solved the “trade-off problem” (Cross-Examination of Dr. Brown, Appeal Book Vol. 15, Tab 347 at pp. 17015-17016). This ground of appeal is therefore dismissed.
2) Did the Judge err in finding that the invention was not obvious? [38] Nova argues that the Judge erred in dismissing the allegation of obviousness. According to Nova, the patent discloses no technical advance because blending all types of ethylene polymers was known and common and therefore a claim to a new composition could not be inventive. This argument was not pursued strenuously at the hearing, and rightly so.
[39] First of all, it bears repeating that factual findings made in applying the test for obviousness should not be reversed absent a palpable and overriding error. In the case at bar, Nova does not question the Judge’s identification of the applicable legal principles, and must therefore meet this heavy onus of satisfying the Court that the Judge made obvious and crucial errors in applying the law to the facts. Nova failed to do so.
[40] I pause to note that Nova’s argument is somewhat disingenuous since Nova’s own patent application for its SURPASS product, filed in 2002, asserts that blending different types of polymers is not free from errors; the Judge quoted from that patent at paragraph 248 of his reasons. Moreover, Nova’s own expert acknowledged the technical advance of the Dow invention, stating that Dow’s invention overcame the “trade-off” problem recognized in the prior art (see Cross-Examination of Dr. Brown, Appeal Book Vol. 15, Tab 347 at pp. 17009 to 17013). One could stop there and dismiss Nova’s argument on that sole basis. But there is more.
[41] The Judge aptly pointed out that Dr. Speed approached the obviousness issue from the wrong perspective. It is well established since the decision of this Court in Beloit Canada Ltd. v. Valmet OY (1986), 8 C.P.R. (3d) 289 at p. 294, 64 N.R. 287 that the reference for the test of obviousness is not the competent inventor, but rather the technician skilled in the art “having no scintilla of inventiveness or imagination”. On cross-examination, Dr. Speed made it clear that he approached the question of obviousness from the perspective of a skilled person who has both inductive reasoning and imagination, an error that the Judge identified and which accordingly undermined his analysis.
[42] The Judge also refused to consider another patent (the “Garza Patent”), published in April 1994, for the purpose of determining the obviousness of the ‘705 Patent, or more specifically, the obviousness of Claim 11 of the ‘705 Patent. As previously mentioned, the ‘705 Patent has a filing date of April 19, 1994 but claims priority from a US patent application filed on April 28, 1993. Counsel for Nova submitted that the US patent does not disclose the full density range stated in part (a) of Claim 11, so that its claim date is therefore the filing date of the ‘705 Patent. If that be the case, the Garza Patent should have been considered for obviousness purposes with respect to Claim 11.
[43] The Judge refused to decide the priority date of Claim 11, however, for lack of evidence. He found that Nova failed to establish that Dow could not claim the benefit of its April 1993 priority date for Claim 11. This is a pure finding of fact, and Nova cannot succeed on appeal by merely restating the argument made at trial and rejected by the Judge without showing a palpable and overriding error.
[44] As a result, Nova’s submission must be dismissed.
3) Did the Judge err in finding that the claims were not broader than the invention made or disclosed? [45] Nova submits that the Judge erred in finding that the claims of the patent are not broader than the invention made or than the invention disclosed in the specification. These are two well established limitations on the extent of the monopoly which an inventor may validly claim (see Farbwerke Hoechst A.G. vormals Meister Lucius & Bruning v. Canada (Commissioner of Patents), [1966] Ex. C.R. 91 at para. 20, 31 Fox Pat. C. 64 (Ex. Ct.), aff’d [1966] S.C.R. 604, 50 C.P.R. 220 (S.C.C.)). The first limitation is a question of fact, whereas the second is a question of construction.
[46] In his report, Dr. Speed suggested that he could not find in the inventor’s documents any work showing that they made, or even contemplated, compositions with more than one homogeneously branched interpolymer or more than one heterogeneously branched interpolymer. Yet there was evidence before the Judge that the inventors did contemplate compositions with more than one Component A or B polymer. In any event, the Judge also accepted Dr. Lai’s testimony that the invention only required Components A and B, and that people were free to add other components to make further improvements (Cross-Examination of Dr. Lai, Appeal Book Vol. 12, Tab 341 at pp. 15992-15994). In his expert report, Dr. Scott also stated that persons skilled in the art would not require testing with other components as they would appreciate from the experiments conducted on blends of Component A and Component B polymers that additional polymers of this type could be included in the blends without detracting from the overall benefit that the blend provides (Expert Report of Dr. Scott, Appeal Book Vol. 35, Tab 192 at p. 6054, para. 168). That view is consistent with the testimony given by Dr. Soares, according to whom the POSITA would understand that other polymers in addition to the specific claimed Component A and Component B could be included in the blends, provided they do not adversely affect the properties of the composition (see the Rebuttal Expert Report of Dr. Soares, Appeal Book Vol. 36, Tab 194 at para. 44; Examination in Chief of Dr. Soares, Appeal Book Vol. 22, Tab 361 at pp. 19581 to 19582). The Judge was entitled to prefer that evidence to that of Dr. Speed.
[47] It is also clear that Dr. Speed’s view with respect to the claims being broader than the invention disclosed was premised on his theory that the ‘705 Patent promised an enhanced level of utility or “synergistically enhanced properties” for all compositions. On that basis, he concluded that all claims are missing at least one feature that the patent says is required of the interpolymers that are useful for the claimed compositions. Having rejected that construction of the patent and of its promise, however, the Judge was inexorably led to the conclusion that Dr. Speed’s determination of what is essential and missing from the claims was flawed. I see no error in such a finding.
[48] It is no doubt true a claim may be too broad if it gives the patentee a wider protection than his discovery entitles him to receive. As President Thorson stated in Radio Corp. of America v. Raytheon Manufacturing Co. (1957), 27 C.P.R. 1 at p. 22, [1956-60] Ex. C.R. 98 (Ex. Ct.):
It is, I think, consistent with principle to say that when a specification discloses the invention of a process for the manufacture of an article in which the use of a special feature of the invention is essential to the success of the invented process the inventor is not entitled to claim a process for the manufacture of the article in which the special feature is not used. He is not entitled to claim a monopoly more extensive than is necessary to protect that which he has invented…
[49] In the case at bar, Nova contends that Dow’s claims are overbroad because they are missing defined limits as to “usefulness” in the patent. One such limit is that “the homogeneously branched ethylene/α-olefin interpolymers do not contain a polymer fraction with a degree of branching less than or equal to 2 methyls/1000 carbons”. Another is that “the homogeneously branched ethylene/α-olefin interpolymers do not contain a polymer fraction with a degree of branching equal to or more than 30 methyls/1000 carbons”. Since Claims 41 and 43 do not contain the first limitation and no claims contain the second limitation, it is said that all the claims at issue are invalid for being broader than the invention disclosed.
[50] The Judge rejected that argument, not only because it is tied to Dr. Speed’s flawed argument on an alleged promise of synergy, but also because no evidence was presented that the person skilled in the art would have considered any of these missing elements to be essential. The fact that a feature is discussed in the specifications does not necessarily mean that such a feature is of the essence of the patent (Whirlpool Corp. v. Camco Inc. (1997), 76 C.P.R. (3d) 150 at p. 166, [1997] F.C.J. No. 1086 (F.C.T.D.); Lovell Manufacturing Co. v. Beatty Brothers Ltd. (1962), 41 C.P.R. 18 at p. 66, 23 Fox Pat. C. 112 (Ex. Ct.)). Yet, Dr. Speed seems to assume that every feature of Components A and B referenced in the disclosure is essential.
[51] Both Dr. Soares and Dr. Scott opined that a person skilled in the art would infer from the description that every preferred range discussed is essential to both the making of the invention and their understanding of how to make the blends of the invention. The Judge preferred their evidence and accepted that the properties of the blend of polymers must be looked at as a whole and not in isolation. This construction is bolstered by the fact that some embodiments disclosed in the patent do not include the allegedly essential features missing from some or all of the claims, which tend to confirm Dr. Soares’ and Dr. Scott’s opinion that a person skilled in the art would not consider these features as being essential. As a result, I can see no palpable and overriding error in the Judge’s findings.
4) Did the Judge err in inferring that SHC is determined using a load/elongation curve? [52] In its Amended Statement of Claim, Dow argued that the polyethylene film-grade copolymers manufactured and sold by Nova under the SURPASS name met the limitations of Component A of all of the asserted claims to the extent that they had an SHC greater than or equal to 1.3, thereby infringing the ‘705 Patent. Critical to that argument is the procedure to calculate the SHC. Nova asserts that the Judge erred in accepting Dow’s submission that the SHC is to be determined by using load/elongation curves, since the patent teaches that it must be done by using a stress/strain curve.
[53] The patent teaches that improvements in the desired properties of Component A can be predicted on the basis of the slope of strain hardening coefficient. It adds that for the interpolymers used in the invention, the SHC “is greater than 1.3, preferably greater than 1.5”, and that it will typically be “less than 10, more typically less than 4, and most typically less than 2.5”.
[54] There is no dispute between the experts that the skilled person with the common general knowledge as of 1994 would understand the terms “strain hardening coefficient” in the context of the ‘705 Patent to be a quantity related to the rate of change in load with respect to elongation in the strain-hardening region, and the melt index, which is a constant for a given polymer. The exact nature of that relationship is set out at page 10 (lines 10-13) of the patent as: “SHC=(slope of strain hardening) * (I2)0.25, where I2 = melt index in grams/10 minutes”.
[55] The patent also teaches how the slope of strain hardening is measured and the protocol for doing so. In particular, it states:
The tensile properties of the test sample is tested on an Instron Tensile Tester at a crosshead speed of 1 inch/minute (2.5 cm/minute). The slope of strain hardening is calculated from the resulting tensile curve by drawing a line parallel to the strain hardening region of the resulting stress/strain curve. The strain hardening region occurs after the sample has pulled its initial load (i.e., stress) usually with little or no elongation during the initial load) and after the sample has gone through a slight drawing stage (usually with little or no increase in load, but with increasing elongation (i.e., strain)). In the strain hardening region, the load and the elongation of the sample both continue to increase. The load increases in the strain hardening region at a much lower rate than during the initial load region and the elongation also increase, again at a rate lower than that experienced in the drawing region. Figure 1 shows the various stages of the stress/strain curve used to calculate the slope of strain hardening. The slope of the parallel line in the strain hardening region is then determined.
‘705 Patent, p. 9, line 29 to p. 10, line 9
[56] As noted by the Judge, the main dispute between the parties on this issue boils down to the type of tensile curve that should be use