DETAILED ACTION
Claim Objections
Claim 1 is objected to because of the following informalities:
In line 1 of claim 1, insert “a” to recite “A preparation process of a composite membrane for fuel cells”.
Line 4 of claim 1 should recite “irradiating the base membrane by an ultraviolet lamp”.
Line 7 of claim 2 should recite “vacuum drying the base membrane”.
Line 1 of claim 6 should recite “wherein a drying temperature”.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
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, 4, 6-7, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over CN 101667648 A (Song ‘648 – citing to the attached English translation) in view of CN 108878993 A (Hongmei ‘993 – citing to the attached English translation), CN 101752574 A (Huang ‘574 – citing to the attached English translation), and CN 110459790 A (Wendi ‘790 – citing to the attached English translation).
Regarding claim 1, Song ‘648 teaches a preparation process of a composite membrane for fuel cells (a method for preparing a water-retaining proton exchange membrane for fuel cells; [0017]), wherein the base membrane is a tetrafluoroethylene microporous membrane (the water-retaining proton exchange membrane is an expanded polytetrafluoroethylene microporous membrane; [0030]) with a pore diameter of 1-20 μm (the membrane has a pore size of 0.05 µm to 1 µm; [0030]), a porosity of 65%-90% (the porosity may be greater than 80%; [0030]), and a thickness of 1-30 μm (the thickness of the membrane may be between 10 and 100 µm; [0030]), comprising the following steps of:
(b) impregnating the pre-treated base membrane in a solution I (by impregnating the membrane with perfluorosulfonic acid resin solution of different concentrations twice, the perfluorosulfonic acid resin component and silicon dioxide component in the solution can effectively fill the micropores of the expanded polytetrafluoroethylene microporous membrane, reducing the air permeability of the water-retaining proton exchange membrane; [0032]), wherein the solution I is a mixture of a perfluorosulfonic acid resin solution (a perfluorsulfoacid resin solution; [0018]), a water-retaining agent (solvent and silica are added to a perfluorosulfonic acid resin solution; [0018]; silica/silicon dioxide; [0032]), wherein in the solution I, a concentration of the perfluorosulfonic acid resin solution is 0.1 wt. %-1 wt. % (a mass concentration of 0.1 % to 4.5 %; [0018]), a mass of the water-retaining agent is 2%-5% of that of the perfluorosulfonic acid resin (the mass ratio of the silica to the perfluorosulfonic acid resin is 0:1 to 0.15:1, which is between 0% and 15%; [0018])
(c) impregnating the base membrane after completion of step (b) in a solution II (by impregnating the membrane with perfluorosulfonic acid resin solution of different concentrations twice, the perfluorosulfonic acid resin component and silicon dioxide component in the solution can effectively fill the micropores of the expanded polytetrafluoroethylene microporous membrane, reducing the air permeability of the water-retaining proton exchange membrane; [0032]), wherein the solution II is a mixture of a perfluorosulfonic acid resin solution (solution II having a perfluorosulfonic acid resin; [0019]), a water-retaining agent (silica; [0019]), wherein in the solution II, a concentration of the perfluorosulfonic acid resin solution is 2 wt. %-6 wt. % (mass concentration of 5% to 20% of the perfluorosulfonic acid resin solution; [0019]), a mass of the water-retaining agent is 2%-5% of that of the perfluorosulfonic acid resin (the mass of the silica to the perfluorosulfonic acid resin is 0:1-0.15:1, which is between 0% and 15%; [0019]),
However, Song ‘648 does not disclose a free radical quencher.
Hongmei ‘993 discloses adding a free radical quencher to a proton exchange membrane to improve the electrochemical stability of the proton exchange membrane and slow down the electrochemical degradation of proton exchange membranes, making them better suited for use in fuel cells ([0007] & [0011]).
In step (1), an ion exchange resin containing sulfonic acid groups is dissolved in a solvent to prepare a resin solution ([0012]). The ion exchange resin containing solution containing sulfonic acid groups used in step (1) mainly include one or more of perfluorosulfonic acid resin (commercial Nafion) or sulfonated polyether ether ketone (SPEEK) ([0018]). In step (2), the nanoparticles of the free radical quencher were added to the resin solution and ultrasonically dispersed evenly ([0013]). The free radical quenchers added to the proton exchange membrane include one or more of cerium dioxide, manganese dioxide, and ferric oxide ([0017]). The free radical quencher was added in an amount 0.02 - 0.15 times the mass of the sulfonic acid resin, which is between 2% and 15% of the mass of the sulfonic acid resin ([0020]).
Therefore, it would have been obvious to a person of ordinary skill in the art, prior to the effective filing date of the claimed invention, to include a free radical quencher in an amount between 2% and 15% in the perfluorosulfonic acid resin solution, wherein the mass of the water retaining agent (mass of the free radical quencher was added in an amount 0.02 - 0.15, overlapping with 0.02 to 0.05; [0020] of Hongmei ‘993) and the mass of the free radical quencher (the mass of the silica to the perfluorosulfonic acid resin is 0:1-0.15:1, overlapping with 0.02 to 0.05; [0019] of Song ‘648) may be 1:1, because both may be added in an amount between 2% and 5% to the perfluorosulfonic acid resin, as suggested by Hongmei ‘993, in solutions I and II for the preparation process of the composite membrane for fuel cells, as taught by Song ‘648.
Further, as set forth in MPEP 2144.05, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)).
Song ‘648 does not disclose the following step of (a) pre-treatment of base membrane: impregnating a base membrane in an alkaline solvent and then irradiating the base membrane by an ultraviolet lamp.
Huang ‘574 discloses a preparation method of a proton exchange membrane, wherein the impregnation of low carbon alcohol and the irradiation of ultraviolet light are applied simultaneously during pretreatment ([0023]). The advantage of using low carbon alcohol to impregnate the polytetrafluoroethylene microporous membrane is that it modifies the surface of the polytetrafluoroethylene microporous membrane, adjusts the contact angle with the sulfonic acid resin solution, and increases the rate at which the solution penetrates into the micropores ([0023]). Ultraviolet light radiation improves the ability of the sulfonic acid resin solution to penetrate into the polytetrafluoroethylene microporous membrane ([0023]). The low carbon alcohol may be propanol or isopropanol, corresponding to the alkaline solvent ([0015]).
Therefore, it would have been obvious to a person of ordinary skill in the art, prior to the effective filing date of the claimed invention, to include a pre-treatment step of the base membrane, wherein the impregnation of isopropanol and the irradiation of ultraviolet light are applied simultaneously during pre-treatment, to improve the ability of the sulfonic acid resin solution to penetrate into the micropores, as suggested by Huang ‘574, in the preparation process of the composite membrane for fuel cells, as taught by Song ‘648.
Song ‘468 does not disclose step (d) impregnating the base membrane after completion of step (c) in a solution III, performing the first-stage cooling after drying, wherein the solution III is a mixture of the perfluorosulfonic acid resin solution with a concentration of 7 wt. %-20 wt. % and a sulfonated polyetheretherketone solution with a concentration of 7 wt. %-20 wt. %, and a mass ratio of the perfluorosulfonic acid resin and the sulfonated polyetheretherketone is 1:1.
Wendi ‘790 discloses a method of improving fiber properties of a PTFE microporous membrane substrate that is characterized by a mixed additive coating including, but not limited to, 1-20 parts by weight of perfluorosulfonic acid resin dispersion with a mass fraction of 20-30%, 0-10 parts of SPEEK, and 30-50 parts of ethanol ([0012]). In particular, the addition of SPEEK significantly improves the tensile strength of the membrane, indicating that it has a significant effect on improving the tensile strength of the matrix ([0065]).
The perfluorosulfonic acid resin may be contained in an amount of 10 parts, and the SPEEK may be contained in an amount of 10 parts, for example, which is 1:1.
Therefore, it would have been obvious to a person of ordinary skill in the art, prior to the effective filing date of the claimed invention, to include a third solution containing a mixture of perfluorosulfonic acid resin resolution at 10 parts and SPEEK, corresponding to sulfonated polyetheretherketone, at 10 parts, in a mass ratio of 1:1, to improve the tensile strength of the membrane, as suggested by Wendi ‘790, in the preparation process of the composite membrane for fuel cells, as taught by Song ‘648.
Song ‘648 discloses removed the membrane from solution II and drying the membrane at a temperature between 60°C to 150°C ([0024]), wherein the process of spraying coating, and drying is repeated until the thickness of the membrane reaches the predetermined requirement ([0056]).
The limitations of performing a first-stage cooling and a second-stage cooling after drying, without specific temperature range definitions disclosing that the first-stage cooling, the second-stage cooling, and drying are conducted at different temperature ranges at different locations with separate equipment, i.e., a drying oven and a cooling treatment area with air coolers, each set to different temperatures (see embodiment 1 in [0045] - [0054] of the PG PUB US 20240039024 A1 of the present invention), are rendered obvious by the disclosure of drying the membrane at a temperature between 60°C and 150°C in Song ‘648.
Regarding claim 4, Song ‘648 teaches the preparation process according to claim 1, wherein in step (b), the water-retaining agent is one of SiO2, ZnO, TiO2, and Al2O3 (the water-retaining component is silica/silicon dioxide; [0032] – [0033] of Song ‘648), the free radical quencher is one of MnO, MnO2, CeO2, and ZrO2 (the free radical quenchers added to the proton exchange membrane include one or more of cerium dioxide (CeO2) and manganese dioxide (MnO2); [0017] of Hongmei ‘993), and a solvent of the perfluorosulfonic acid resin solution is at least one of isopropanol and n-propanol (the low carbon alcohol may be propanol or isopropanol, corresponding to the alkaline solvent; [0015] of Huang ‘574).
Regarding claim 6, Song ‘648 teaches the preparation process according to claim 1, wherein the drying temperature is 40 – 150 °C (the membrane is dried at a temperature between 60°C to 150°C; [0024] of Song ‘648).
Further, as set forth in MPEP 2144.05, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)).
Regarding claim 7, Song ‘648 teaches the preparation process according to claim 1, wherein the impregnation times of the base membrane in the solutions I, II, and III are respectively 1.3, 1.1, and 0.7 times of a thickness of the base membrane by minutes (by impregnating the membrane with perfluorosulfonic acid resin solution of different concentrations twice, the perfluorosulfonic acid resin component and silicon dioxide component in the solution can effectively fill the micropores of the expanded polytetrafluoroethylene microporous membrane, reducing the air permeability of the water-retaining proton exchange membrane; [0032] of Song ‘648; the process of spraying coating, and drying is repeated until the thickness of the membrane reaches the predetermined requirement; [0056] of Song ‘648).
Regarding claim 10, Song ‘648 teaches a composite membrane for fuel cells, wherein the composite membrane is obtained according to the preparation in claim 1 (a method for preparing a water-retaining proton exchange membrane for fuel cells; [0017] of Song ‘648).
Song ‘648 teaches a water-retaining proton exchange membrane for fuel cells, and thus, teaches a composite membrane for fuel cells.
Claim 10 is considered a product-by-process claim. The cited prior art teaches all of the positively recited structure of the claimed apparatus or product. The determination of patentability is based upon the apparatus structure itself. The patentability of a product or apparatus does not depend on its method of production or formation. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. See In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (see MPEP § 2113).
Allowable Subject Matter
The following is a statement of reasons for the indication of allowable subject matter:
Claims 2-3, 5, and 8-9 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 2, none of the cited references teach that in step (a), the pre-treatment of base membrane comprises the following steps of:
(1) impregnating the base membrane in a 3 wt. %-5 wt. % hydrogen peroxide solution under 60-80° C. for 20-60 minutes;
(2) washing the impregnated base membrane with deionized water;
(3) impregnating the washed base membrane in an isopropanol solvent for 0.5-1 hours;
(4) vacuum dying the base membrane after completion of step (3) for 2-3 hours under an environment filled with protective gas; and
(5) ultraviolet irradiating the base membrane after completion of step (4) at a wavelength of 185 nm for 10-15 minutes in an environment filled with oxygen.
Claim 3 depends from claim 2, and thus, incorporates the indicated allowable subject matter of claim 2.
Regarding claim 5, none of the cited references disclose a temperature of the first-stage cooling being 40-50 °C, and a temperature of the second-stage cooling being 0-10 °C, which corresponds to one of the advantages disclosed in [0035] of the PG Pub US 20240039024 A1 of the present invention, wherein a gradual cooling results in avoiding defects such as strong rigidity and brittleness after a sudden drop of the base membrane temperature coming out of the drying oven without a cooling treatment area.
Regarding claim 8, none of the cited references disclose that the preparation process adopts a continuous impregnation device for production, wherein the continuous impregnation device comprises a treatment tank I, a drying oven I, a treatment tank II, a drying oven II, a treatment tank III, and a drying oven III arranged successively along a transmission direction of the composite membrane; each outlet of the drying ovens I, II, and III is provided with a cooling treatment area acting on the base membrane, wherein each cooling treatment area comprises an air cooler I near the outlet of the drying oven, and an air cooler II near the inlet of the treatment tank; and the continuous impregnation device is further provided with a plurality of drive rollers for transferring the composite membrane forward, which corresponds to one of the advantages disclosed in [0035] of the PG Pub US 20240039024 A1 of the present invention, wherein a gradual cooling results in avoiding defects such as strong rigidity and brittleness after a sudden drop of the base membrane temperature coming out of the drying oven without a cooling treatment area.
Claim 9 depends from claim 8, and thus, incorporates the indicated allowable subject matter of claim 8.
Conclusion
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/TAYLOR HARRISON KRONE/Examiner, Art Unit 1725
/JONATHAN CREPEAU/Primary Examiner, Art Unit 1725