Ex Parte Bulan et alDownload PDFPatent Trial and Appeal BoardDec 20, 201613307059 (P.T.A.B. Dec. 20, 2016) Copy Citation 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. 13/307,059 11/30/2011 Andreas Bulan 074023-0322-286835 1883 123223 7590 12/22/2016 Drinker Biddle & Reath LLP (WM) 222 Delaware Avenue, Ste. 1410 Wilmington, DE 19801-1621 EXAMINER LEWIS, BEN ART UNIT PAPER NUMBER 1726 NOTIFICATION DATE DELIVERY MODE 12/22/2016 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): IPDocketWM @ dbr.com penelope. mongelluzzo @ dbr. com DB RIPDocket @ dbr. com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte ANDREAS BULAN, JURGEN KINTRUP, and STEFANIE EIDEN Appeal 2015-007246 Application 13/307,059 Technology Center 1700 Before CHUNG K. PAK, JEFFREY T. SMITH, and WESLEY B. DERRICK, Administrative Patent Judges. SMITH, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134(a) from a final rejection of claims 1 through 20.1 We have jurisdiction under 35 U.S.C. § 6(b). STATEMENT OF THE CASE Appellants’ invention is generally directed to an oxygen-consuming electrode comprising at least one support element, a coating comprising a gas diffusion layer and a catalytically active component, and an additional layer on the gas diffusion layer consisting essentially of a fluoropolymer that 1 Final Office Action entered November 21, 2013 (“Final Act.”). Appeal 2015-007246 Application 13/307,059 is soluble in solvents. App. Br. 3. Claim 1 illustrates the subject matter on appeal and is reproduced below: 1. An oxygen-consuming electrode comprising at least one support element in the form of a sheet-like structure and a coating comprising a gas diffusion layer and a catalytically active component, wherein the oxygen-consuming electrode further comprises an additional layer on the gas diffusion layer, wherein the additional layer consists essentially of fluoropolymer which is soluble in solvents. App. Br. 18, Claims Appendix. Appellants (see generally App. Br.) request review of the following final rejections maintained by the Examiner in the Answer entered June 3, 2015 (“Ans.”). I. Claims 17 and 18 under 35U.S.C. § 112, fourth paragraph for being in improper dependent form because they fail to further limit the subject matter of the claim from which they depend, or because they fail to include all the limitations of the claim from which they depend.2 II. Claims 1-8, 11,13, 14, 16-19, and 20 under 35 U.S.C. § 103(a) as unpatentable over Schwartz et al. (US 2008/0292931 Al, published November 27, 2008, hereinafter “Schwartz”) and Hong et al. (US 2007/0184334 Al, published August 9, 2007, hereinafter “Hong”). III. Claim 9 under 35 U.S.C. § 103(a) as unpatentable over Schwartz, Hong, and Barton et al. (US 2009/0117449 Al, published May 7, 2009, hereinafter “Barton”). IV. Claim 10 under 35 U.S.C. § 103(a) as unpatentable over 2 The Examiner objected to claims 17 and 18 under 37 CFR 1.75(c) in the Final Office Action, but rejected claims 17 and 18 under 35 U.S.C. § 112, fourth paragraph in the Answer. 2 Appeal 2015-007246 Application 13/307,059 Schwartz, Hong, and Lu et al. (US 2008/0176112 Al, published July 24, 2008, hereinafter “Lu”). V. Claim 12 under 35 U.S.C. § 103(a) as unpatentable over Schwartz, Hong, and Bulan (US 2006/0263232 Al, published November 23, 2006, hereinafter “Bulan”). VI. Claim 15 under 35 U.S.C. § 103(a) as unpatentable over Schwartz, Hong, and Bulan. OPINION After review of the respective positions provided by Appellants and the Examiner, we AFFIRM the Examiner’s rejections of claims 1—20 under 35 U.S.C. § 103(a), but REVERSE the Examiner’s rejection of claims 17 and 18 under 35 U.S.C. § 112, fourth paragraph. We add the following. Rejection I Claim 17 recites an oxygen-consuming cathode in an electrolysis apparatus or an electrode in an alkaline fuel cell or an electrode in a metal/air battery comprising the oxygen consuming electrode according to Claim 1. Claim 18 recites an electrolysis apparatus, comprising the oxygen consuming electrode according to Claim 1 as an oxygen-consuming cathode. The Examiner asserts that claims 17 and 18 are improper dependent claims because they “are a different non-limiting embodiment of claim 1.” Ans. 5. However, “[a] claim which makes reference to a preceding claim to define a limitation is an acceptable claim construction which should not necessarily be rejected as improper . . .” M.P.E.P. § 2173.05(f). We accordingly reverse the Examiner’s rejection of claims 17 and 18 under 35 U.S.C. § 112, fourth paragraph. 3 Appeal 2015-007246 Application 13/307,059 Rejection II Claims 1, 3—8, 11, 13, 14, 17—19, and 203 The Examiner determines that it would have been obvious to one of ordinary skill in the art at the time of the invention to apply a water repellent material as disclosed by Hong as an additional coating layer on the catalyst/gas diffusion layer of the oxygen-consuming electrode disclosed by Schwartz in view of Hong’s disclosure that coating a catalyst with a water repellent material prevents electrolyte from flooding the catalyst and forms a path for oxygen to move to the catalyst. Final Act. 3—5. Appellants argue that Schwartz discloses a gas diffusion substrate coated with a gas diffusion layer, which can comprise a fluoropolymer such as PTFE, and discloses treating the substrate—rather than the gas diffusion layer—to exhibit hydrophilic or hydrophobic behavior. App. Br. 7—8. Appellants further contend that Schwartz does not disclose or suggest that this treatment would involve application of an additional layer of a fluoropolymer that is soluble in solvents. App. Br. 8. Appellants further argue that the gas diffusion layer comprising the fluoropolymer PTFE disclosed in Schwartz is not analogous to the additional fluoropolymer layer recited in claim 1 because the PTFE is used to form the gas diffusion layer itself, rather than an additional layer on the gas diffusion layer. Id. Appellants argue that Hong does not remedy the deficiencies of Schwartz because Hong discloses coating a catalytic powder with a water repellant material, such as Teflon AF 2400, and combining the coated catalytic 3 Appellants argue claims 1, 3—8, 11, 13, 14, 17—19, and 20 together. See generally Appeal Brief. Therefore, we select claim 1 as representative of these claims, and claims 3—8, 11, 13, 14, 17—19, and 20 will stand or fall with claim 1. 37 C.F.R. § 41.37(c)(l)(iv) (2015). 4 Appeal 2015-007246 Application 13/307,059 powder with a binder to form a layer. App. Br. 8—9. Appellants contend that this layer does not consist essentially of fluoropolymer that is soluble in solvents because it primarily includes catalyst powder and binder. Id. Appellants further contend that this layer is not an additional layer of a water repellant material applied to a formed catalyst layer because the layer itself includes the catalyst. App. Br. 9-10. Appellants further argue that Schwartz and Hong taken together do not suggest any additional layer on a gas diffusion layer, much less one that consists essentially of fluoropolymer. App. Br. 10. However, Appellants’ arguments do not persuade us of reversible error in the Examiner’s conclusion of obviousness, for at least the following reasons. Consistent with the Examiner’s findings, Schwartz discloses an oxygen-consuming electrode for a fuel cell that comprises a backing comprising a porous, conductive sheet material (support element) coated on one or both surfaces with a gas diffusion layer or substrate to which catalyst ink is applied. Final Act. 3; Schwartz || 3, 7, 12, 51, 53. The Examiner acknowledges that Schwartz does not disclose an additional layer on the gas diffusion layer that consists essentially of fluoropolymer that is soluble in solvent, and the Examiner relies on Hong for suggesting this feature. Final Act. 4. Specifically, the Examiner correctly finds that Hong discloses an electrode for a fuel cell that includes a catalyst material coated with a layer formed of a water repellent material on the surface of the catalyst material. Final Act. 4; Hong 17. The Examiner also correctly finds that Hong discloses that suitable water repellent materials include 2,2- bistrifhioromethyl-4,5-difluoro-l ,3-dioxol tetrafluoroethylene copolymer, 5 Appeal 2015-007246 Application 13/307,059 which is commercially available as TEFLON AF 2400. Final Act. 4; Hong 125. Appellants do not dispute that TEFLON AF 2400 is soluble in solvents. Compare Final Act. 5, with App. Br. 7—10. The Examiner further correctly finds that Hong discloses that when TEFLON AF 2400 is “coated on the surface of a catalyst layer, [it] prevents phosphoric acid [electrolyte] from flooding the catalyst layer and forms a path for oxygen to move to the catalyst layer.” Final Act. 4; Hong 125. We agree with the Examiner that Hong’s disclosure of the benefits achieved by coating the surface of a catalyst or catalyst layer with a water repellent fluoropolymer such as TEFLON AF 2400 reasonably would have led one of ordinary skill in the art at the time of the invention to apply an additional TEFLON AF 2400 layer to the catalyst/gas diffusion layer of the oxygen-consuming electrode disclosed in Schwartz. Because the catalyst/gas diffusion layer disclosed in Schwartz is coated onto a backing comprising a porous, conductive sheet material, one of ordinary skill in the art reasonably would have been led to coat the water repellant fluoropolymer material disclosed in Hong as an additional layer on the entire surface of the catalyst/gas diffusion layer as recited in claim 1, with a reasonable expectation that doing so would prevent electrolyte from flooding the catalyst and form a path for oxygen to move to the catalyst, as disclosed by Hong. Therefore, Appellants’ arguments are unpersuasive of reversible error, and we sustain the Examiner’s rejection of claims 1, 3—8, 11, 13, 14, 17—19, and 20 under 35 U.S.C. § 103(a). 6 Appeal 2015-007246 Application 13/307,059 Claim 2 Although Appellants argue claim 2 separately, they provide essentially the same arguments that they present for claim 1. App. Br. 10— 12. Because we are unpersuaded of reversible error in the Examiner’s rejection of claim 1 as discussed above, Appellants’ position as to the rejection of claim 2 is also without merit. Accordingly, we sustain the rejection of claim 2 under 35 U.S.C. § 103(a). Claim 16 Claim 16 recites a process for producing the oxygen-consuming cathode according to Claim 1, which comprises applying or spraying a solution of a fluoropolymer onto an oxygen-consuming electrode comprising at least one support element in the form of a sheet-like structure and a coating having a gas diffusion layer and a catalytically active component and subsequently removing the solvent by evaporation. Appellants argue that Schwartz “has nothing to do with an added fluoropolymer layer sprayed on an already-formed electrode,” but instead describes a method for forming a cathode. App. Br. 12—13. However, one of ordinary skill in the art reasonably would have had sufficient skill to apply or spray a solution of a fluoropolymer onto the catalyst/gas diffusion layer disclosed in Schwartz (described above), and reasonably would have removed the solvent by evaporation, in view of the state of the art at the time of Appellants’ invention, as set forth in Appellants’ Specification. Spec. 158. To this end, one of ordinary skill in the art reasonably would have applied the water repellant fluoropolymer material disclosed in Hong as an additional layer on the entire surface of the catalyst/gas diffusion layer disclosed in Schwartz using known coating techniques, such as those 7 Appeal 2015-007246 Application 13/307,059 described in Appellants’ Specification, which include spraying a solution of the fluoropolymer onto the catalyst-coated gas diffusion layer and subsequently removing the solvent by evaporation, as recited in claim 16. Therefore, we sustain the rejection of claim 16 under 35 U.S.C. § 103(a). Rejections III and IV Claim 9 depends from claim 1 and recites that the electrode is coated with from 1 to 100 g of fluoropolymer per square meter of electrode area. Claim 10 depends from claim 1 and recites that the layer thickness of the fluoropolymer layer is from 0.01—100 pm. Appellants argue in essence that the applied prior art does not disclose or suggest an additional layer consisting essentially of fluoropolymer soluble in solvents on a coating comprising a gas diffusion layer and a catalytically active component, and Appellants contend that the disclosures of the applied prior art are therefore not applicable to determining the proper amount and thickness of the fluoropolymer layer. App. Br. 13—16. However, as discussed above, one of ordinary skill in the art would have been led to apply the water repellant fluoropolymer material disclosed in Hong as an additional layer on the entire surface of the catalyst/gas diffusion layer disclosed in Schwartz to prevent electrolyte from flooding the catalyst and to form a path for oxygen to move to the catalyst, as disclosed in Hong. One of ordinary skill in the art would have had sufficient skill to determine the optimum amount and thickness of fluoropolymer, such as the amount recited in claim 9 and thickness recited in claim 10, which would impart the desired electrolyte repellency while still allowing the flow of oxygen to the catalyst. Appellants do not demonstrate the criticality of the recited ranges (App. Br. 13—16), and Appellants’ arguments are therefore 8 Appeal 2015-007246 Application 13/307,059 unpersuasive of reversible error. In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990) (indicating that in cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.). Rejections V and VI Appellants rely on their contentions that the Examiner erred in rejecting the base claim, independent claim 1, from which claims 12 and 15 depend, and argue that Bulan fails to remedy the deficiencies of Schwartz and Hong. App. Br. 16. Because we are unpersuaded of reversible error in the Examiner’s rejection of claim 1, Appellants’ position as to these grounds of rejection is also without merit. Accordingly, we sustain the rejections of claims 12 and 15 under 35 U.S.C. § 103(a). ORDER For the reasons set forth above and in the Answer, the decision of the Examiner is affirmed. TIME PERIOD No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1). AFFIRMED 9 Copy with citationCopy as parenthetical citation