DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 2, 3, 7 and 10 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claims 2, 3, 7 and 10, the phrase "preferably" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-10 and 12-16 are rejected under 35 U.S.C. 103 as being unpatentable over Beutel et al. (US 20090181276 A1; Henceforth, Beutel), in view of Sompalli et al. (US 6524736 B1; Henceforth, Sompalli) and Izumi et al. (US 20060057281 A1; Henceforth, Izumi).
Regarding claim 1, Beutel teaches a method Claim 18) comprising providing a first catalyst coated gas diffusion media layer comprising a first catalyst coating over a gas diffusion media layer (equivalent to step a of the instant claim, where the gas diffusion media layer is a backing layer); and depositing a wet first proton exchange membrane layer over the first catalyst coated gas diffusion media layer (equivalent to step c of the instant claim) and drying the first proton exchange membrane layer to form a first proton exchange membrane layer (equivalent to step d of the instant claim). Beutel, in another embodiment (Claim 13), teaches the catalyst coating over a gas diffusion media layer is wet, or at least partially wet, immediately before depositing the first proton exchange membrane layer. Beutel teaches the first proton exchange membrane layer comprises an ionomer (Claim 10).
Beutel does not explicitly teach a wetting solution is applied to the catalyst layer to form a wetted catalyst surface.
Sompalli teaches a method of making a membrane electrode assembly (Abstract) including a pretreatment step where a porous substrate is coated with a wetting solution such that the solvent is imbibed into the pores (page 1, column 1, lines 58-65) before a layer of material is applied upon it. Sompalli teaches wetting solution is either applied before the application of the layer or provided within the substrate prior to the application (page 4, column 8, lines 47-51), and the saturation of the pores with isopropanol (a wetting solvent) controls and lowers the Nafion seepage into the porous substrate, thereby controlling the Nafion content in the catalyst layer above (page 5, column 10, lines 50-57).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Beutel by incorporating the wetting step taught by Sompalli, in the same field of endeavor. There would have been a motivation, as taught by Sompalli to saturate the pores of a layer before the application of an additional layer, to prevent the seepage of material into the porous material (page 5, column 10, lines 50-57). This is echoed by Izumi in the same field of endeavor, who teaches an application of a first dispersion layer to a wetted catalyst layer, in order to prevent the polymer electrolyte layer doesn't penetrate the interior of the first catalyst layer to deteriorate the electrical properties ([0170]). A person of ordinary skill in the art would have had the reasonable expectation that saturating the pores of the catalyst layer with a wetting solution would have had the predictable effect of limiting the seepage of material from an applied first dispersion layer, as Izumi teaches utilizing a wetted catalyst layer accomplishes the same goal of minimizing seepage as applying a wetting solution to a porous substrate, as taught by Sompalli. See MPEP 2413 (I) C.
Regarding claim 2, Beutel, Sompalli and Izumi teach the method of claim 1. While Beutel teaches the catalyst layer is wet prior to the additional layer being applied (Claim 13), Beutel does not teach the degree of wetting. Sompalli defines the term ”wetting solvent” as a solvent that "wets" the substrate, or spontaneously is imbibed into or permeates the pores of the substrate (page 4, column 8, lines 26-29). Sompalli teaches that the pretreatment of the ePTFE support is necessary before the catalyst layer can be applied, IPA is considered a wetting solvent relative to ePTFE, and, with pretreatment, the pores of the porous support are filled with IPA, or IPA with small amounts of Nafion (page 5, column 10, lines 46-52). The examiner notes that Sompalli teaches the saturation of the pores with isopropanol (a wetting solvent) controls and lowers the Nafion seepage into the porous substrate, thereby controlling the Nafion content in the catalyst layer above (page 5, column 10, lines 50-57). Therefore, the examiner takes the position that all of the pores taught by Sompalli are saturated, in order to get this effect.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, such that the wetting solution saturates all the pores of the catalyst layer, for the reasons outlined in claim 1, above.
Regarding claim 3, Beutel, Sompalli and Izumi teach the method of claim 2. While Beutel teaches the catalyst layer is wet prior to the additional layer being applied (Claim 13), Beutel does not teach the degree of wetting. The examiner notes that Sompalli teaches the saturation of the pores with isopropanol (a wetting solvent) controls and lowers the Nafion seepage into the porous substrate, thereby controlling the Nafion content in the catalyst layer above (page 5, column 10, lines 50-57). Therefore, the examiner takes the position that all of the pores taught by Sompalli are saturated, in order to get this effect.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, such that the wetting solution saturates all the pores of the catalyst layer, for the reasons outlined in claim 1, above.
Regarding claim 4, Beutel, Sompalli and Izumi teach the method of claim 1. Sompalli teaches an example where the wetting solution is isopropanol and the wetting solution can be applied is by means of either screen-printing, painting or spraying (page 5, column 10, lines 46-50). Sompalli further teaches wetting the porous substrate results in the saturation of the pores with isopropanol, such that it controls and lowers the Nafion seepage into the porous substrate (page 5, column 10, lines 50-57). The examiner notes that the process of saturating the pores of the substrate would require an excess of wetting solution to be added, which would form a layer of wetting solution on the surface of the porous substrate. Additionally, the examiner notes isopropanol has a low vapor pressure and is prone to evaporate under standard conditions.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1 wherein the wetting solution forms a layer of wetting solution on top of the catalyst layer and including a step to at least partially remove the layer of wetting solution whilst retaining wetting solution within the pores prior to the application of the first dispersion layer. Sompalli demonstrates precedent for saturating the pores of a porous substrate prior to the addition of an additional layer by utilizing an isopropanol solution (page 5, column 10, lines 46-57). In order to saturate the pores, an excess of wetting solution would be needed, which necessarily results in a layer of excess wetting solution left over. Since Sompalli teaches the application means can be one of screen-printing, painting or spraying (page 5, column 10, lines 46-50), the excess material would most likely be in a film on the top face of the porous substrate, meeting the instant claim’s requirement that a layer of wetting solution is formed on top of the porous layer. It is the examiner’s position that, due to the tendency of isopropanol to evaporate, at least a portion of the wetting solution would be likely to evaporate prior to the application of the first dispersion layer. While the amount that would reasonably evaporate would be small, this would still render obvious the limitation of at least partially removing a portion of the wetting solution of the instant claim.
Regarding claim 5, Beutel, Sompalli and Izumi teach the method of claim 1. Sompalli teaches an example where the wetting solution is isopropanol (page 5, column 10, lines 46-50). The examiner notes isopropanol is a polar solvent.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, such that the wetting saturates comprises a polar solvent. There would have been a motivation, as taught by Sompalli, to utilize isopropanol as the wetting solvent, since it is capable of saturating the pores of the porous substrate (page 5, column 10, lines 46-57).
Regarding claim 6, Beutel, Sompalli and Izumi teach the method of claim 5. Sompalli teaches an example where the wetting solution is isopropanol (page 5, column 10, lines 46-50).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, such that the wetting saturates comprises isopropanol, for the reasons outlined in claim 5.
Regarding claim 7, Beutel, Sompalli and Izumi teach the method of claim 5. Sompalli teaches an example where the wetting solution is either ~ 0.1 wt % Nafion in isopropanol or pure isopropanol (page 5, column 10, lines 46-50).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, such that the wetting saturates comprises isopropanol, for the reasons outlined in claim 5.
Regarding claim 8, Beutel, Sompalli and Izumi teach the method of claim 1. Sompalli teaches that the first dispersion layer utilizes a high degree of non-wetting solvents in order to minimize the amount of ionomer that penetrates the pores of the porous substrate, and that the porous substrate is impervious to water and methanol (page 5, column 9, lines 18-31). Sompalli teaches an example where the first dispersion continuous phase utilizes methanol, as it does not wet the porous substrate (page 5, column 10, lines 28-32).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1 wherein the wetting solution has a higher degree of wetting towards the catalyst layer than the degree of wetting of the first dispersion to the catalyst layer. There would have been a motivation, as taught by Izumi in the same field of endeavor, to apply the first dispersion layer to a wetted catalyst layer, in order to prevent the polymer electrolyte layer doesn't penetrate the interior of the first catalyst layer to deteriorate the electrical properties ([0170]). This would only have the desired effect if the first dispersion layer has a less degree of wetting towards the catalyst layer than the wetting solution; this aspect is also motivated by Sompalli, who teaches the first dispersion layer needs to utilize a high amount of non-wetting solvents to mitigate the amount of ionomer that penetrates the pores (page 5, column 9, lines 18-31). Taken together, a person of ordinary skill in the art would have a reasonable expectation that utilizing a wetting solution that has a higher degree of wetting towards the catalyst layer than the first dispersion layer does towards the catalyst layer would mitigate the infiltration of ionomers into the pores of the catalyst layer. See MPEP 2143 (I) C.
Regarding claim 9, , Beutel, Sompalli and Izumi teach the method of claim 1. Sompalli teaches an example where the first dispersion continuous phase utilizes methanol (page 5, column 10, lines 28-32). The examiner notes that methanol is a polar solvent other than water.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1 wherein the continuous phase utilizes a polar solvent other than water, for the reasons outlined in claim 8 above.
Regarding claim 10, Beutel, Sompalli and Izumi teach the method of claim 9. Sompalli teaches the general range of solid content to the continuous phase in first dispersion layer is 13% to 27%; for the ratio of solids to liquids of the examples given, this equates to about 80% by weight methanol, and the remaining solid components make up the remaining portion of the slurry’s mass (page 5, column 10, lines 38-45). The examiner notes the amount of methanol (being the continuous phase of the slurry) lies within the range of the instant claim and therefore anticipates it. See MPEP 2131.03 (I).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1 wherein the continuous phase comprise less than 90% by weight a polar solvent that is not water, for the reasons outlines in claim 9, above.
Regarding claim 12, Beutel, Sompalli and Izumi teach the method of claim 1. Beutel teaches an embodiment, after depositing a wet first proton exchange membrane layer on a first catalyst coated gas diffusion layer (Claim 1), a second catalyst coated gas diffusion media layer comprising a second catalyst coating over a gas diffusion media layer; and contacting the second catalyst coated gas diffusion media layer with the wet first proton exchange membrane layer (Claim 2). The examiner notes that, since the second catalysts coated layer contacts the wet first proton exchange membrane layer, the second catalyst layer would need to be, at least, partially stacked on top of the wet first proton exchange membrane layer. While Beutel does not discuss a distinct drying step for this particular example, Beutel teaches a step of hot-pressing this material (Claim 4 and Example 1, [0036]) and a drying step in a different embodiment, after the final dispersion layer is applied (Claim 18). Izumi teaches a similar example, where a catalyst coating compound is spread on top of a polymer electrolyte which was spread over a different catalyst coating, followed by a drying step ([0188])
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, by adding a catalyst dispersion layer covering the first dispersion layer. A person of ordinary skill in the art would have had the reasonable expectation that the substitution of the hot-pressing step presented in Claim 4 of Beutel for the drying step of Izumi would be a reasonable alternative to remove the solvent from the deposited layers, functionally drying the membrane, since Izumi teaches the step can be results in a membrane electrode assembly in a fuel cell without further steps ([0188]), in a nearly identical manner to that described by Beutel ([0036]). See MPEP 2143 (I) D.
Regarding claim 13, Beutel, Sompalli and Izumi teach the method of claim 1. Beutel teaches an example ([0036]) wherein a catalyst layer is disposed on a carbon fiber paper with microporous layer. Beutel teaches this catalyst-coated carbon fiber substrate was heated at 80°C, before an ionomer dispersion is applied ([0036]). Therefore, Beutel teaches depositing a catalyst layer on a backing layer (the carbon fiber paper with a microporous layer), and that the substrate, with the catalyst coating is dried. Therefore, Beutel teaches the added limitations of claim 13.
Regarding claim 14, Beutel, Sompalli and Izumi teach the method of claim 1. Izumi teaches examples where, once all the layers are deposited and dried, the backing substrate is peeled off, resulting in a suitable membrane electrode assembly (Example 1: [0160]; Example 2, [0188]). Izumi teaches that the substrate is utilized in order to allow for the continuous preparation of membrane electrode assemblies ([0148]), as depicted in Figures 1 and 2, below (element 9 is the backing substrate).
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Figure 1, reproduced from Izumi.
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Figure 2, reproduced from Izumi.
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1 by removing the backing layer after the final dispersion layer is deposited and dried. Izumi demonstrates precedent to form multi-layered membrane electrode assemblies on top of a removable backing layer, to enable the continuous production of membrane electrode assemblies ([0148]). A person of ordinary skill in the art would have had the reasonable expectation that forming a multilayered membrane electrode assembly by the method of claim 1 on a removable backing layer would have the benefit of allowing for membrane electrode assemblies to be continually produced in a production line manner, based on the teachings of Izumi. See MPEP 2143 (I) C.
Regarding claim 15, Beutel teaches a method (Claims 18 and 19) comprising of the steps of providing a first catalyst coated gas diffusion media layer and a second catalyst coated gas diffusion media layer; depositing a wet first proton exchange membrane layer over the first catalyst coated gas diffusion media layer and drying the first proton exchange membrane layer to form a first proton exchange membrane layer (this makes a membrane with two faces, as shown in Figure 2, annotated below); depositing a wet second proton exchange membrane layer over the second catalyst coated gas diffusion media layer and drying the second proton exchange membrane layer to form a second proton exchange membrane layer; interposing a sub-gasket between the first proton exchange membrane layer and the second proton exchange membrane layer; and hot pressing the first proton exchange membrane layer formed over the first catalyst coated gas diffusion media layer and the second proton exchange membrane layer formed over the second catalyst coated gas diffusion media layer together. Beutel further teaches the application of a sub-gasket on top of the proton exchange membrane layer ([0024]), may provide desired chemical, mechanical, and electrical properties and functions at the perimeter of the finished membrane electrode assembly and may also include an integral elastomeric-type seal. The examiner notes this constitutes a seal material, in concordance with the instant claim.
While Beutel does not explicitly teach a wetting step before the application of the proton exchange membrane layers, thereby not fully teaching the method of claim 1, this aspect is remedied by the teachings of Sompalli and Izumi, as described above. Therefore, since Beutel, Sompalli and Izumi teach the method of claim 1, and Beutel teaches the additional limitations of the instant claim, claim 15 is rendered obvious.
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Figure 2, reproduced from Beutel, annotated by the examiner.
Regarding claim 16, Beutel teaches a method (Claim 18) comprising of the steps of providing a first catalyst coated gas diffusion media layer and a second catalyst coated gas diffusion media layer; depositing a wet first proton exchange membrane layer over the first catalyst coated gas diffusion media layer and drying the first proton exchange membrane layer to form a first proton exchange membrane layer; depositing a wet second proton exchange membrane layer over the second catalyst coated gas diffusion media layer and drying the second proton exchange membrane layer to form a second proton exchange membrane layer; and hot pressing the first proton exchange membrane layer formed over the first catalyst coated gas diffusion media layer and the second proton exchange membrane layer formed over the second catalyst coated gas diffusion media layer together. The examiner notes the hot pressing step is equivalent to applying a gas diffusion layer on to one of the faces of the catalyst-coated ion-conducting membrane.
The examiner notes Beutel does not explicitly teach a wetting step before the application of the proton exchange membrane layers, thereby not fully teaching the method of claim 1. As described in claim 1, above, this aspect is remedied by the teachings of Sompalli and Izumi. Therefore, since Beutel, Sompalli and Izumi teach the method of claim 1, and Beutel teaches the additional limitations of the instant claim, claim 16 is rendered obvious.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Beutel, Sompalli and Izumi in view of Sompalli et al. (US 20070213203 A1; Henceforth, US’203).
Regarding claim 11, Beutel, Sompalli and Izumi teach the method of claim 1. Beutel teaches, in Example 4 ([0039]), multiple ionomer coatings can be applied in the same manner as described in Claim 1, to get to a desired thickness. The examiner notes that the method described in the claim 1 of Beutel is a component set of steps to that are performed in the method described in claim 18 of Beutel, with the exception that claim 1 does not explicitly teach a drying step.
While the examiner is of the position that multiple isomer coatings constitute additional dispersion layers, US’203 teaches a process wherein a first and second ionomer overcoat layer are applied on top of a catalyst layer (Abstract; [0021]-[0023]), with a drying step in between ([0021]). US’203 teaches each of the multiple overcoat layers (up to a sixth layer, [0021]) may utilize the same ionomer solution or different ionomer solutions with different amounts of wetting versus non-wetting solvents ([0022]-[0023]). US’203 teaches this gradient of wetting to non-wetting solvents leaves an ionomer skin the surface of the decal which allows for improved bonding to the membrane ([0023]) and improved cell performance compared to utilizing the same solution for each layer (Table 1 and [0030]). Additionally, US’203 teaches utilizing multiple thin coatings perform better than a single coating of equal thickness of the plurality of thin coatings (Table 1 and [0030]).
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of claim 1, by adding an additional dispersion layer to the first dispersion layer. Beutel teaches the step can be repeated to add additional layers in order to get the desired thickness ([0039]), and US’203 teaches up to six layers of coatings with different ionomer solutions can be applied in a similar manner as a first ionomer solution. A person of ordinary skill in the art would have a reasonable expectation that utilizing multiple ionomer layers would improve the cell performance compared to one layer, based on the teachings of US’203. While US’203 teaches a drying step occurs after each ionomer coating is added ([0021]), the instant claim language does not preclude additional steps, and the final drying step, after the addition of the last layer, would dry all layers simultaneously, as solvent from the final layer may penetrate into lower layers to some degree. Therefore, the drying step of the instant claim is rendered obvious by the teachings of US’203.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN P MURPHY whose telephone number is (571)272-9321. The examiner can normally be reached Monday - Friday 8:00 am - 5:30 pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nicholas A Smith can be reached at (571) 272-8760. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/RPM/Examiner, Art Unit 1752
/NICHOLAS A SMITH/Supervisory Primary Examiner, Art Unit 1752
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