Ex Parte Vyas et alDownload PDFBoard of Patent Appeals and InterferencesJul 21, 201111089525 (B.P.A.I. Jul. 21, 2011) 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. 11/089,525 03/24/2005 Gayatri Vyas GP-306114 1172 65798 7590 07/22/2011 MILLER IP GROUP, PLC GENERAL MOTORS CORPORATION 42690 WOODWARD AVENUE SUITE 200 BLOOMFIELD HILLS, MI 48304 EXAMINER SCULLY, STEVEN M ART UNIT PAPER NUMBER 1727 MAIL DATE DELIVERY MODE 07/22/2011 PAPER 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. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ________________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ________________ Ex parte GAYATRI VYAS, Richard H. Blunk, Thomas A. Trabold, Reena L. Datta, and Keith E. Newman ________________ Appeal 2010-003749 Application 11/089,525 Technology Center 1700 ________________ Before BEVERLY A. FRANKLIN, MARK NAGUMO, and KAREN M. HASTINGS, Administrative Patent Judges. NAGUMO, Administrative Patent Judge. DECISION ON APPEAL1 1 See related Appeal 2009-014718 in application 11/089,526, also decided on this day. Appeal 2010-003749 Application 11/089,525 2 A. Introduction2 Gayatri Vyas, Richard H. Blunk, Thomas A. Trabold, Reena L. Datta, and Keith E. Newman (“Vyas”) timely appeal under 35 U.S.C. § 134(a) from the final rejection3 of claims 1-7 and 9-20.4 We have jurisdiction. 35 U.S.C. § 6. We AFFIRM. The subject matter on appeal relates to fuel cells in which the hydrogen fluoride (“HF”) generated from the perfluorosulfonic acid membrane commonly used in proton exchange membrane fuel cells etches a hydrophilic metal oxide layer deposited on the surface of the flow field (“bipolar”) plates. The flow field plates separate the cathodic (hydrogen gas) side of the fuel cell from the anodic (oxygen gas) side of the adjacent fuel cell in a stack of fuel cells. (Spec. 1-2, [004]-[006].) The hydrophilic metal oxide layer helps prevent blockage of the gas channels in the plate by water produced by the reactions in the cell that would otherwise bead up on the hydrophobic metal oxides of typical metal flow field plates. (Id. at 2 [0007], 3 [0009].) The thickness of the hydrophilic metal oxide layer is selected such that the etch rate continuously exposes a clean metal 2 Application 11/089,525, Durable Hydrophilic Coatings for Fuel Cell Bipolar Plates, filed 24 March 2005. The specification is referred to as the “525 Specification,” and is cited as “Spec.” The real party in interest is listed as General Motors Corp. (Appeal Brief, filed 17 June 2009 (“Br.”), 1.) 3 Office action mailed 23 January 2009 (“Final Rejection”; cited as “FR”). 4 The Examiner has objected to claim 8 (FR 1), the only other claim, which is not before us. Appeal 2010-003749 Application 11/089,525 3 oxide surface, and also so that the hydrophilic metal oxide layer is not etched away prior to a predetermined lifetime of the cell.5 The cleansing effect of the hydrogen fluoride is said to remove contaminants that would otherwise collect on and significantly reduce the hydrophilicity of the metal oxide layers. Fuel cells that do not use a perfluorosulfonic acid membrane can be provided with a separate hydrogen fluoride source that injects a dilute HF solution into one or both of the hydrogen or oxygen gas streams. (Spec. 5 [0013]-[0014].) Representative Claim 1 reads: 1. A fuel cell comprising a flow field plate being made of a plate material, said flow field plate including a plurality of flow channels responsive to a reactant gas, said flow field plate further including an outer layer that makes the flow field plate hydrophilic, wherein the material of the outer layer and the thickness of the outer layer are selected so that hydrofluoric acid within the fuel cell etches away an outer surface of the layer at a rate so that a clean surface of the outer layer is continuously exposed, but the outer layer is not completely etched away over a predetermined lifetime of the fuel cell. (Claims App., Br. 10; indentation and paragraphing added.) 5 The structure of the fuel cells and the flow field plates, and additional benefits of the hydrophilic character of the selected metal oxides are discussed in related appeal 2009-014718. Appeal 2010-003749 Application 11/089,525 4 The Examiner has maintained the following grounds of rejection:6 A. Claims 1-7 and 9-20 stand rejected under 35 U.S.C. § 102(b), alternatively under 103(a) in view of Ohara.7 B. Claims 1-5 and 11-14 stand rejected under obviousness-type double patenting in view of Vyas 526, claims 1-3.8 C. Claims 1-5 and 11-14 stand rejected under obviousness-type double patenting in view of Vyas 489, claims 1-2.9 B. Discussion Findings of fact throughout this Opinion are supported by a preponderance of the evidence of record. Ohara Vyas argues that Ohara does not anticipate or render the claimed subject matter obvious. In Vyas’s view, Ohara does not teach or suggest selecting the material of the outer layer and the thickness of the outer layer so the outer layer is etched at a rate suitable to continuously expose a clean surface of the outer layer and such that the outer layer is not completely removed before the end of the useful life of the fuel cell. (Br. 5, 6.) In particular, Vyas argues that, in paragraph [0173], Ohara states that the metal 6 Examiner’s Answer mailed 17 September 2009 (“Ans.”). 7 Hideo Ohara et al., Polymer Electrolyte Fuel Cell, United States Patent Application Publication 2003/0003345 A1 (2003) 8 Gayatri Vyas et al., 11/089,526, filed 24 March 2005; Examiner affirmed in appeal 2009-014718, decided on this day. 9 Gayatri Vyas et al., 11/068,489, filed 25 February 2005; Examiner reversed in appeal 2010-004061 (9 May 2011); notice of allowance mailed 1 June 2011. Appeal 2010-003749 Application 11/089,525 5 oxide films (0.5 to 0.05 μm [500 nm to 50 nm] thick) formed on the gas flow channels were cleaned, “while recovering the defect and reproducing the metal oxide film on the surface of the gas flow channels.” (Br. 5, 1st full para, quoting Ohara [0173]; cf. 6, 1st full para.) Vyas concludes that because Ohara does not teach or suggest the relation between the thickness of the layer and the etching rate by hydrofluoric acid, neither the anticipation nor the obviousness rejections are proper. Vyas does not argue for the separate patentability of any claims. Accordingly, all claims stand or fall with claim 1. The Examiner found, and Vyas does not dispute, that Ohara describes fuel cell stacks based on a NAFION® [a sulfonated tetrafluoroethylene copolymer sold by DuPont] polymer electrolyte membrane, with metal conductive separator plates made from stainless steel (aluminum or titanium are also said to be useful) and coated with metal oxides including the hydrophilic species Al2O3 and Nb2O5, from 50 to 500 nm thick. (FR. 3; Ans. 3.) The Examiner finds further that Ohara describes a continuous driving test of 8000 hours, after which the oxide layer was not etched away. (FR 3, and Ans. 4, both citing Ohara 13 [0168].) The Examiner argues that the Nafion® membrane will release hydrofluoric acid under the fuel cell operating conditions, that the hydrofluoric acid will etch the metal oxide layer, and that the thickness dictates, in part, the lifetime of the cell. (FR 4, 5; Ans. 4, 5) The Examiner argues further that a recitation of the manner of operation of an apparatus does not distinguish a claimed apparatus from a prior art apparatus that satisfies all the recited structural limitations, and concludes that the fuel cells described by Ohara anticipate Appeal 2010-003749 Application 11/089,525 6 the claimed fuel cells. (FR 3; Ans. 3) In the alternative, the Examiner argues that Ohara teaches that the thickness of the metal oxide layer is a result effective variable with respect to the variation in the fuel cell output, so selection of the thickness in a given range would have been obvious. (FR 3, 4; Ans 3-4, 5.) As the predecessor to our reviewing court observed forty years ago, “‘[f]unctional’ terminology may render a claim quite broad. By its own literal terms a claim employing such language covers any and all embodiments which perform the recited function.” In re Swinehart, 439 F.2d 210, 213 (CCPA 1971). Moreover, it is settled law that when the PTO identifies prior art that is the same or substantially the same as claimed subject matter, the burden shifts to the applicant to come forward with evidence and argument showing that the prior art products do not necessarily or inherently possess the characteristics of the claimed product. In re Best, 562 F.2d 1252, 1254-55 (CCPA 1977). In the present appeal, the undisputed overlap in the range of preferred metal oxide thicknesses taught by Ohara and the undisputed similarity of the fuel cells in other material respects provide a strong expectation that the operating properties of the fuel cells will be similar. Vyas has failed to come forward with credible evidence or argument showing that the fuel cells taught or suggested by Ohara are patentably distinct from the fuel cells for which Vyas is seeking exclusionary protection. In particular, Vyas has failed to demonstrate that the recited etching does not occur in the Ohara fuel cells, or that the outer layer is completely etched away prior to “a predetermined lifetime of the fuel cell,” as required by claim 1. Appeal 2010-003749 Application 11/089,525 7 In this regard, the Examiner’s observations regarding the failure of the method of operating a device to distinguish a claim to the underlying device are well taken. See In re Casey, 370 F.2d 576, 580 (CCPA 1967) (“The manner or method in which such machine is to be utilized is not germane to the issue of patentability of the machine itself.”) Elementary chemical and physical considerations indicate that the lifetime of a fuel cell depends in large measure on the conditions under which it is operated. Example 10 of Ohara, described in paragraphs [0171] through [0173], on which Vyas bases the arguments against the prior art rejections, provides strong evidence that operating conditions affect the output, and by reasonable inference, the lifetime, of the exemplified fuel cells. Table 9 lists the output of various fuel cells, two of which have oxides preferred by Vyas (Al2O3 and Ta2O5), operated under continuous driving method A, and under driving method B, in which oxidant gas was provided to both the fuel gas flow channel and the oxidant gas flow channel at every 2000 hours. Table 9 shows that the decrease in output power of the fuel cell was less for method B in every case. It is reasonable to conclude that the useful lifetime of the fuel cells is longer when operated under method B. Thus, the evidence of record illustrates the breadth of the claims. Particularly in light of the breadth of the claims, we are not persuaded by Vyas’s arguments that the Examiner erred harmfully in holding the claimed fuel cells obvious in view of those described and suggested by Ohara. Appeal 2010-003749 Application 11/089,525 8 Provisional obviousness-type double patenting rejections Vyas raises essentially the same argument against the rejections in view of claims in the copending applications, namely that those claims “do not claim the relationship between selecting the material of the outer layer and the thickness of the outer layer in relationship to the etch rate of [the] hydrofluoric acid and the lifetime of the fuel cell.” (Br. 7, 8; cf. Reply 3, last para.) As discussed in our consideration of the prior art rejection, whether the prior art recognizes a now-recited or newly discovered property of an old apparatus is not relevant to patentability. We conclude that Vyas’s arguments fail to demonstrate harmful error in the Examiners’ provisional obviousness-type double patenting rejections. C. Order We AFFIRM the rejection of claims 1-7 and 9-20 under 35 U.S.C. § 102(b), alternatively under § 103(a) in view of Ohara. We AFFIRM the rejection of claims 1-5 and 11-14 under obviousness-type double patenting in view of Vyas 526, claims 1-3. We AFFIRM the rejection of claims 1-5 and 11-14 under obviousness-type double patenting in view of Vyas 489, claims 1-2. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). AFFIRMED ssl Copy with citationCopy as parenthetical citation