Shin-Etsu Chemical Co., Ltd.

Patent Trials and Appeals Board

Jan 20, 2022

2021000542 (P.T.A.B. Jan. 20, 2022)

UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 15/196,770 06/29/2016 Masakatsu HOTTA 0171-1866PUS1 7611 2292 7590 01/20/2022 BIRCH STEWART KOLASCH & BIRCH, LLP 8110 Gatehouse Road Suite 100 East Falls Church, VA 22042-1248 EXAMINER CANTELMO, GREGG ART UNIT PAPER NUMBER 1725 NOTIFICATION DATE DELIVERY MODE 01/20/2022 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): mailroom@bskb.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte MASAKATSU HOTTA Appeal 2021-000542 Application 15/196,770 Technology Center 1700 Before TERRY J. OWENS, CATHERINE Q. TIMM, and LILAN REN, Administrative Patent Judges. TIMM, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 14, 20, 21, and 29-33. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as Shin-Etsu Chemical Co., Ltd. Appeal Br. 1. Appeal 2021-000542 Application 15/196,770 2 CLAIMED SUBJECT MATTER The claims are directed to a solid polymer fuel cell having a silicone rubber separator seal of a particular silicone rubber composition. See claims 14 and 33. The composition includes a magnesium and aluminum- containing layered double hydroxide, such as hydrotalcite. Id.; Spec. 3:19- 34. The broadest claims now require the layered double hydroxide be present in a concentration of from 0.1 to 2.0 wt% per 100 wt% of the silicone rubber composition exclusive of the layered double hydroxide (hereinafter we use the shorthand 0.1-2.0 wt%). Id. Claim 14, reproduced below with the limitation most at issue italicized, is illustrative of the claimed subject matter: 14. A solid polymer fuel cell having a separator seal comprising, in a cured form, a silicone rubber composition comprising: (A) 100 parts by weight of an organopolysiloxane having at least two silicon atom-bonded alkenyl groups per molecule, wherein component (A) does not contain fluorine; (B) 0.5 to 20 parts by weight of an organohydrogenpolysiloxane having at least three silicon atom- bonded hydrogen atoms (Si-H groups) per molecule, wherein component (B) does not contain fluorine; (C) 5 to 30 parts by weight of fumed silica having a specific surface area as measured by the BET method of 50 to 400 m2/g; and (D) a catalytic amount of an addition reaction catalyst, and, compounded therewith a magnesium and aluminum-containing layered double hydroxide, wherein the content of the layered double hydroxide Appeal 2021-000542 Application 15/196,770 3 is from 0.1 to 2.0 wt% per 100 wt% of the silicone rubber composition exclusive of the layered double hydroxide, wherein the solid polymer fuel cell comprises an electrolyte membrane containing a fluoropolymer having sulfonic acid groups and wherein the solid polymer fuel cell is configured for use in an environment in which hydrogen fluoride is generated when the fuel cell is operated. Claims Appendix of the Appeal Br. 1 (emphasis and formatting added). REJECTION Claims 14, 20, 21, and 29-33 are rejected under 35 U.S.C. § 112(a) as failing to comply with the written description requirement. Final Act. 2. Specifically, the Examiner finds there is no written descriptive support for the newly recited 0.1-2.0 wt% layered double hydroxide concentration range given there is evidence that this newly recited range results in an unexpected compression set property not discussed in the Specification. Final Act. 3-5. OPINION Appellant does not argue any claim apart from the others. Appeal Br. 6-11. We select claim 14 as representative for resolving the dispositive issue on appeal. We state the issue as: Has Appellant identified a reversible error in the Examiner’s finding that the original Specification fails to reasonably convey possession, at the time of filing, of the invention now claimed, i.e., a genus of silicone rubbers containing components (A)-(D) of claim 14 where including from 0.1-2.0 wt% of a magnesium and aluminum-containing layered double hydroxide results in unexpectedly improved compression set properties? Appeal 2021-000542 Application 15/196,770 4 Appellant has not identified such an error. 35 U.S.C § 112(a) requires the Specification to “contain a written description of the invention” and this “requirement is satisfied only if the inventor ‘convey[s] with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention.’” Nuvo Pharms. (Ireland) Designated Activity Co. v. Dr. Reddy’s Labs. Inc., 923 F.3d 1368, 1376-77 (Fed. Cir. 2019) (quoting Centocor Ortho Biotech, Inc. v. Abbott Labs., 636 F.3d 1341, 1348 (Fed. Cir. 2011)). “[T]he test requires an objective inquiry into the four corners of the specification from the perspective of a person of ordinary skill in the art.” Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc). Thus, we first consider how the Specification describes the invention. Appellant’s Specification describes the invention as related to “a sealing material for separators in solid polymer fuel cells that can be used as small fuel cells.” Spec. 1:15-20. This sealing material is described as a cured product of an addition curable-type liquid silicone rubber that contains a layered double hydroxide. Spec. 6:27-34; Spec. 16:3-6. The Specification states that the sealing material “has an excellent durability to hydrogen fluoride that arises from electrolyte membranes made of fluoropolymer.” Spec. 1:15-20. The Specification explains that addition cured silicone rubbers have been widely studied as sealing materials for solid polymer fuel cell separators. Spec. 2:12-21. These silicone rubbers have excellent moldability, heat resistance, and elasticity. Id. Although the prior art describes improvements to the acid resistance, compression set, and adhesion of these silicone sealing materials, contact with hydrofluoric acid Appeal 2021-000542 Application 15/196,770 5 within the solid polymer fuel cell still caused the seals to deteriorate. Spec. 2:3-33. The prior art solved this problem by sealing the periphery of the silicone rubber with another resin. Spec. 3:6-11. According to the Specification, Appellant improves hydrofluoric acid resistance in a different manner. Specifically, according to the Specification, Appellant formulates a seal material that “includes a silicone rubber composition and, compounded therewith, a specific amount of a layered double hydroxide, especially hydrotalcite.” Spec. 3:19-24. Further, according to the Specification, “[t]he layered double hydroxide is preferably magnesium and aluminum-containing hydrotalcite, and typically has been dehydrated by firing.” Spec. 3:28-34. And its content “is preferably from 0.1 to 20 wt% per 100 wt% of the silicone rubber composition, exclusive of the layered double hydroxide.” Id. The Specification provides further guidance as to the amount of layered double hydroxide that will improve hydrofluoric acid resistance. The amount is “preferably from 0.1 to 20 wt%, and more preferably from 0.5 to 10 wt%, per 100 wt% of the silicone rubber composition, exclusive of the layered double hydroxide.” Spec. 6:15-24. The Specification explains that “[w]ithin this range, the effects of including the layered double hydroxide are better achieved” and that “including the layered double hydroxide in an amount of more than 20 wt% may lower the flowability of the silicone rubber composition after compounding and may lead to a decline in the sealing performance due to excessive hardening.” Id. The Specification describes working examples containing a specific silicone rubber composition containing either non-dehydrated hydrotalcite of general formula Mg6Al2(CO3)(OH)16·4H2O or dehydrated hydrotalcite of Appeal 2021-000542 Application 15/196,770 6 general formula Mg6Al2O9 in amounts of either 2.0 wt% (Working Examples 1 and 3) or 10.0 wt% (Working Examples 2 and 4). Spec. 18-20. The Specification also includes comparative examples including the same silicone rubber with either no fluorine scavenger (Comparative Example 1) or 2.0 wt% cerium hydroxide, which reportedly has an ability to absorb fluorine (Comparative Example 2). Id. Thus, the Specification conveys possession of a genus of silicone rubbers containing the components (A) through (D) compounded with layered double hydroxides of the genus disclosed in the Specification (Spec. 5) in a concentration that is expected to improve hydrofluoric acid resistance without excessively hardening the seal, which concentration is disclosed as 0.1-20 wt%, with a preference for 0.5-10 wt%. The Specification also conveys possession of the compositions of Working Examples 1 and 3, which contain a specific silicone rubber and 2.0 wt% hydrotalcite. Spec. 20 at Table 1. There is no dispute that Appellant’s Specification fails to expressly disclose the narrower 0.1-2.0 wt% range now claimed. But that, of course, does not end the inquiry. Implicit and inherent disclosures may provide support. Novartis Pharms. Corp. v. Accord Healthcare, Inc., No. 2021-1070, 2022 WL 16759, at *8 (Fed. Cir. Jan. 3, 2022). “Written description may take any form, so long as a skilled artisan would read the disclosure as describing the claimed invention.” Id. In fact, in some circumstances, the above facts might reasonably convey to the ordinary artisan that Appellant was in possession of a genus of silicone rubbers containing the (A)-(D) components of claim 14 and hydrotalcite in the range of 0.1-2.0 wt% given the Specification discloses an Appeal 2021-000542 Application 15/196,770 7 encompassing range of 0.1-20 wt% and also discloses Working Examples 1 and 3 with 2 wt% hydrotalcite. See In re Wertheim, 541 F.2d 257, 264 (CCPA 1976) (finding a process involving concentrating a coffee extract to a solids content range of 35-60 wt% was supported in light of the somewhat broader described range of 25-60 wt% along with specific embodiments of 36 wt% and 50 wt%). But the facts here differ from those of Wertheim and we must be mindful that “the written-description analysis is highly dependent on the facts of each case.” Biogen Int’l GMBH v. Mylan Pharms. Inc., 18 F.4th 1333, 1342 (Fed. Cir. 2021). In some circumstances, such as the circumstances of our case, a broader range may not describe all the narrower ranges within it. Indivior UK Limited v. Dr. Reddy’s Labs. S.A., 18 F.4th 1323, 1328 (Fed. Cir. 2021) (“In the case of a claimed range, a skilled artisan must be able to reasonably discern a disclosure of that range.”); see also Wertheim, 541 F.2d at 264-65 (“Where it is clear, for instance, that the broad described range pertains to a different invention than the narrower (and subsumed) claimed range, then the broader range does not describe the narrower range.”) (citing In re Baird, 348 F.2d 974 (CCPA 1965)); In re Draeger, 150 F.2d 572 (CCPA 1945)). So a key question in our case is “whether the invention appellants seek to protect by their claims is part of the invention that appellants have described as theirs in the specification.” Indivior, 18 F.4th at 1330. In deciding the above question, we consider the prosecution leading to the Hotta Declaration. During prosecution, the Examiner rejected all the pending claims as obvious, relying on Okonogi as teaching a silicone separator seal with components (A)-(D), minus layered double hydroxide, and secondary Appeal 2021-000542 Application 15/196,770 8 references to support a finding of a suggestion of including the layered double hydroxide in concentrations within the previously recited range of 0.1-10 wt%. Non-Final Act. of June 11, 2019 at 3-13. In response, Appellant narrowed the range of magnesium and aluminum-containing layered double hydroxide from 0.1-10 wt% to 0.1-2.0 wt% and submitted the Hotta Declaration. Amendment and Hotta Declaration of October 21, 2019 (“Hotta Declaration” or “Hotta Decl.”). In the accompanying remarks, Appellant relies on the data as showing unexpected results, stating: The data reported in the Declaration supports the conclusion that in the presently claimed solid polymer fuel cell, the presence of a ‘content of the layered double hydroxide [that] is from 0.1 to 2.0 wt% per 100 wt% of the silicone rubber composition exclusive of the layered double hydroxide’ is unexpectedly significant with regard to sealing characteristics. Remarks of October 21, 2019 at 10. The Hotta Declaration reports compression set data for a silicone-based material containing various concentrations of hydrotalcite in the range of 0-5 wt%. Hotta Decl. 2-4. In the Final Office Action, the Examiner states that “[t]he prior art rejections set forth in the previous Office Action have been withdrawn in light of the amendment and Rule 1.132 Declaration.” Final Act. 2. The Examiner offers no further explanation and given that neither Appellant, nor the Hotta Declaration, explains what compression set results would have been expected and what is deemed the closest prior art, the basis for withdrawing the obviousness rejection is unclear. “To be particularly probative, evidence of unexpected results must establish that there is a difference between the results obtained and those of the closest prior art, and that the difference would not have been expected by one of ordinary skill in Appeal 2021-000542 Application 15/196,770 9 the art at the time of the invention.” Bristol-Myers Squibb Co. v. Teva Pharms. USA, Inc., 752 F.3d 967, 977 (Fed. Cir. 2014). In any case, because the Examiner withdrew the obviousness rejection, there is no obviousness rejection for us to review here and, thus, we do not consider the question of whether the totality of the evidence supports a conclusion of non- obviousness. We discuss the above prosecution history because it is relevant to the question that is before us, i.e., whether the original Specification reasonably conveys that Appellant was in possession of the invention now claimed. The invention now claimed is a silicone seal having magnesium and aluminum- containing layered double hydroxide in a concentration of 0.1-2.0 wt%, which is a concentration low enough to minimally effect compression set, a result Hotta declares is unexpected. Hotta Decl. 4. The Examiner relied on the Hotta Declaration to support the finding of lack of written description support based on the fact the Hotta Declaration provided evidence that the narrowed 0.1-2.0 wt% range was to a different invention than what was described in the written description. The Examiner said: The fact pattern of this case raises a reasonable rejection under 35 U.S.C. 112(a) because applicant is now alleging that the newly claimed range (content of the layered double hydroxide in the range from 0.1 to 2.0 wt% per 100 wt% of the silicone rubber composition exclusive of the layered hydroxide) is a different invention than the originally disclosed range (content of the layered double hydroxide in the range from 0.1 to 20 wt% per 100 wt% (preferably from 0.5 to 10 wt%) of the silicone rubber composition exclusive of the layered hydroxide - see page 6 of the specification) since the newly claimed range is held to have properties unique from the originally disclosed Appeal 2021-000542 Application 15/196,770 10 range as evidenced by the 1.132 Declaration filed on October 21, 2019. Final Act. 3. Appellant’s Specification is silent on the effects of magnesium and aluminum-containing double hydroxide on compression set. The Specification instead focuses on the concentration range for obtaining hydrofluoric acid resistance. The Examiner’s analysis is rightly distinguished from Wertheim on the basis that, unlike in Wertheim, Appellant has presented data of unexpected results for the narrowed range in an attempt to overcome an obviousness rejection. By pointing to the declaratory evidence, the Examiner met the burden of supporting the rejection for lack of written descriptive support by presenting sufficient reason to doubt that the invention described as using the layered doubled hydroxide in a broader range to achieve hydrofluoric acid resistance describes the invention of using that component in the narrower claimed range to achieve unexpected compression set properties. Wertheim, 541 F.2d at 264. Thus, the burden shifted to Appellant to show that the narrower 0.1- 2.0 wt% range was supported such as by showing that the narrower range is inherently supported. “Our case law has recognized that, under a narrow set of circumstances, the written description requirement may be satisfied without an explicit disclosure if the claimed features are necessarily inherent in what is expressly described.” Nuvo Pharms., 923 F.3d at 1382-83; see also Wertheim, 541 F.2d 257, 264 (CCPA 1976) (“Appellants thus have the burden of showing that the upper limit of solids content described, i. e., 60%, is inherent in ‘at least 35%,’ as that limitation appears in claim 1.”). Appeal 2021-000542 Application 15/196,770 11 Appellant presents no persuasive evidence that the range of 0.1-2.0 wt% magnesium and aluminum-containing layer double hydroxide is inherently supported. Ours is not a case with an open-ended range with an inherent endpoint. See Andersen Corp. v. Fiber Composites, LLC, 474 F.3d 1361, 1376-77 (Fed. Cir. 2007); Wertheim, 541 F.2d at 264. The most relevant evidence of inherency lies in the Working Examples, but although Working Examples 1 and 3 contain 2.0 wt% hydrotalcite in a specific silicone rubber, the plain language of claim 14 is broader. Claim 14 encompasses a genus of silicone rubbers that can contain any one of a genus of magnesium and aluminum-containing layered double hydroxides. Appellant presents no persuasive evidence that hydrotalcite is synonymous with magnesium and aluminum-containing layered double hydroxide. Also, the two working examples do not provide enough data points to support a finding of inherent support for the 0.1-2.0 wt% range especially given that the Specification’s preferred 0.5-10 wt% range leads away from, rather than towards the 0.1-2.0 wt% range now claimed. See In re Lukach, 442 F.2d 967, 969 (CCPA 1971) (holding that a single example inherently disclosing a copolymer having a Mw/Mn ratio of 2.6 did not alone provide support for a range of from 2.0 to 3.0 where no other language, taken together with the knowledge of persons skilled in the art, pointed to the recited range). Although we agree with Appellant that a showing of unexpected results may be properly considered in an obviousness analysis even if those results are presented after the date of filing the application (Appeal Br. 10-11), we agree with the Examiner that those results must inherently flow from what was originally disclosed in order to have written descriptive support (Ans. 15). See Genetics Institute, LLC v. Novartis Vaccines and Diagnostics, Inc., Appeal 2021-000542 Application 15/196,770 12 655 F.3d 1291 (Fed. Cir. 2011) (holding that it was proper to consider an unexpected vWF binding property of a Factor VIII protein in the obviousness analysis even though the binding property was unknown as of the filing date because the ability to bind was an inherent property of the protein); Nuvo Pharm., 923 F.3d at 1383 (holding that a failure of proof indicating that uncoated PPI was inherently effective in raising gastric pH to at least 3.5 doomed Nuvo’s argument that the gastric pH limitation was supported by the written description). In closing, we reproduce the summary provided in Indivior about the fact intensive nature of the written descriptive analysis as it applies to ranges and how a comparison of ranges and mechanical rules do not suffice: But written description cases are intensively fact-oriented, and the cases vary, just as ranges vary. Wertheim specified that the court was “not creating a rule applicable to all description requirement cases involving ranges” and that “[b]roadly articulated rules are particularly inappropriate in this area.” Wertheim, 541 F.2d at 263-65 (Rich, J.). “Mere comparison of ranges is not enough, nor are mechanical rules a substitute for an analysis of each case on its facts to determine whether an application conveys to those skilled in the art the information that the applicant invented the subject matter of the claims. In other words, we must decide whether the invention appellants seek to protect by their claims is part of the invention that appellants have described as theirs in the specification.” Id. at 263. Thus, no case, with necessarily varied facts, controls the resolution of the written description issue in this case. Indivior, 18 F.4th at 1329-30. After considering all the facts relied on by the Examiner and Appellant in this case, we determine that a preponderance supports the Examiner’s finding of lack of written descriptive support. Appeal 2021-000542 Application 15/196,770 13 CONCLUSION The Examiner’s decision to reject claims 14, 20, 21, and 29-33 is affirmed. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 14, 20, 21, 29-33 112(a) Written Description 14, 20, 21, 29-33 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED