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 .
Response to Amendments
This is a final office action in response to applicant's arguments and remarks filed on
07/28/2026.
Status of Rejections
The rejection of claim 18 is obviated by the Applicant’s cancellation.
All other previous rejections are maintained.
New rejections are presented for the new claims.
Claims 1-17 and 19-22 are pending and under consideration for this Office Action.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1-14, 17, and 20-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al (US 20180073155 A1) in view of Higa (US 20250332546 A1).
Claim 1: Suzuki discloses a separator (see e.g. abstract) for dividing an anode from a cathode (see e.g. [0013]) comprising:
a porous polymer film (see e.g. [0150]), the porous polymer film comprising a high-density polymer (see e.g. [0052]), the porous polymer film
(a) containing a hydrophilic additive (“hydrophilic inorganic particles”, see e.g. [0085]), the hydrophilic additive being present in the porous polymer film in an amount of at least about 5% by weight (see e.g. [0130]).
Suzuki teaches that the porous polymer film high-density can be a polyethylene polymer amongst a list of others (see e.g. [0049]). KSR rationale E states that it is obvious to choose ‘from a finite number of identified, predictable solutions, with a reasonable expectation of success’ and MPEP § 2144.07 states ‘The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)’. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to select polyethylene as the film material.
The film of Suzuki has a thickness of 300-600 microns (see e.g. [0082]), which overlaps with the claimed range of about 5 microns to about 600 microns. MPEP § 2144.05 states ‘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)’.
Suzuki does not explicitly teach a molecular weight required for the polyethylene and thus a person having ordinary skill in the art before the effective filing date of the instant invention would be motivated to find and use a suitable molecular weight polyethylene. Higa discloses an ion exchange membrane (see e.g. abstract) for water electrolysis (see e.g. [0273]), making it analogous art. See MPEP § 2141.01(a)I. The membrane of Higa is ultra-high molecular weight polyethylene having a molecular weight of 1,000,000 to 6,300,000 which “improves the durability of the resulting ion exchange membrane and also suppresses swellability” (see e.g. [0186]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify Suzuki by using the ultra-high molecular weight polyethylene taught in Higa for the improved durability and suppression of swellability. The molecular weight range of 1,000,000 to 6,300,000 overlaps with the claimed range of greater than about 500,000 g/mol. MPEP § 2144.05 states ‘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)’.
Claim 2: Suzuki in view of Higa teaches that the porous polymer film has a porosity of 30%-60% (see e.g. Suzuki - [0019]), which falls within the claimed range of from about 25% to about 85%.
Claim 3: Suzuki in view of Higa teaches that the high-density polyethylene polymer has a number average molecular weight of 1,000,000 to 6,300,000 (see e.g. Higa - [0186]), which overlaps the claimed range of greater than about 600,000 g/mol and less than about 12,000,000 g/mol. MPEP § 2144.05 states ‘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)’.
Claim 4: Suzuki in view of Higa teaches that the porous polymer film comprises an extruded film (see e.g. Suzuki – [0034]) that has been stretched in at least one direction (see e.g. Suzuki - [0039]).
Claim 6: Suzuki in view of Higa teaches that the porous polymer film has a thickness of 300-600 microns (see e.g. Suzuki – [0082]), which overlaps with the claimed range of from about 5 microns to about 500 microns. MPEP § 2144.05 states ‘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)’.
Claim 7: Suzuki in view of Higa teaches that the separator is a single layer porous polymer film that may optionally include a coating (see e.g. Suzuki - [0030]).
Claim 8: Suzuki in view of Higa teaches that the single layer porous polymer film includes a coating (see e.g. Suzuki - [0030]), the coating comprising Group IV elements, specifically zirconium oxide (see e.g. Suzuki - [0086]).
Claim 9: Suzuki in view of Higa teaches that the single layer porous polymer film includes a hydrophilic coating on each side of the porous polymer film (see e.g. Suzuki - [0030]; [0133]).
Claim 10: Suzuki in view of Higa teaches that the separator is polypropylene-free (polypropylene is taught as a possible material for the separator but is not required, see e.g. Suzuki - [0049]). KSR rationale E states that it is obvious to choose ‘from a finite number of identified, predictable solutions, with a reasonable expectation of success’. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to not select polypropylene from the list of possible materials.
Claim 11: Suzuki in view of Higa teaches that the film contains the hydrophilic additive, the hydrophilic additive comprising inorganic particles (see e.g. Suzuki - [0085]), the inorganic particles having a particle size D50 of 5 μm or less (see e.g. Suzuki – [0090]), which falls within the claimed range of 20 μm or less.
Claim 12: Suzuki in view of Higa teaches that the hydrophilic additive is present in the porous polymer film in an amount of at least about 5 to 40 mass % (see e.g. Suzuki – [0165]), which overlaps with the claimed range of 10% by weight and less than about 90% by weight. MPEP § 2144.05 states ‘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)’.
Claim 13: Suzuki in view of Higa teaches that the porous polymer film has an average pore size of 0.8 to 1.2 microns (see e.g. Suzuki – [0057]), which overlaps with the claimed range of greater than about 0.005 microns and less than about 1 micron. MPEP § 2144.05 states ‘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)’.
Claim 14: Suzuki in view of Higa teaches that hydrophilic additive comprises Group IV elements, specifically zirconium oxide (see e.g. Suzuki - [0086]).
Claim 17: The claim claims a property of the polymer film. Suzuki in view of Higa teaches all of the positively recited structure of claim 1, which claim 17 depends on. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the properties of the instant invention and Suzuki in view of Higa would be substantially similar.
Claim 20: Suzuki in view of Higa teaches a water electrolysis device (see e.g. Suzuki - abstract; Fig 1) comprising a separator as defined in claim 1 (see rejection of claim 1 above) located between a cathode and an anode (see e.g. Suzuki – [0205]; #11 and #21 on Fig 1).
Claim 21: Suzuki in view of Higa teaches the porous polymer film has an average pore size of 0.5 microns (see e.g. Suzuki - [0020]), which is considered close to the claimed range of “less than 0.5 microns”. MPEP § 2144.05 I states ‘Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) ’.
Claim 22: Suzuki does not explicitly teach that the porous polymer film has a thickness of from 10 microns to 200 microns. Suzuki teaches a thickness of 300 microns for a desired membrane strength (see e.g. [0082]). However, the rejection of claim 1 stated, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify Suzuki by using the ultra-high molecular weight polyethylene taught in Higa for the improved durability and suppression of swellability. Higa teaches that the ultra-high molecular weight polyethylene has good strength (“durability”) with thicknesses up to 100 microns. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the separator of Suzuki in view of Higa by adjusting the thickness of the ultra-high molecular weight polyethylene polymer film between 20 microns and 600 microns (the total ranges of Suzuki and Higa) to get the desired strength and ion permeation.
Claim(s) 15 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki in view of Higa as applied to claim 1, and in further view of Shi et al (CN 109554724 A, Espacenet translation used for citations)
Claim 15: Suzuki in view of Higa does not explicitly teach that the hydrophilic additive comprises a hydrophilically modified polyethylene polymer. Shi teaches a membrane for water electrolysis (see e.g. [0001]), making it analogous art. See MPEP § 2141.01(a)I. Shi modifies the membrane by hydrophilically modifying the top surface of membrane using a plasma treatment to form polar groups for “excellent hydrophilicity” (see e.g. [0032]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the membrane of Suzuki by including an additive (the polar groups) by modifying the polymer of the membrane with a hydrophilic plasma treatment as taught in Shi to achieve excellent hydrophilicty. The plasma treatment applied to Suzuki would generate hydrophilically modified polyethylene polymer.
Claim 19: Suzuki in view of Higa and Shi does not explicitly teach that the film has been plasma oxidized to form polar groups attached to the high-density polyethylene polymer that increases the polarity of the surface of the porous polymer film. Shi teaches a membrane for water electrolysis (see e.g. [0001]), making it analogous art. See MPEP § 2141.01(a)I. Shi modifies the membrane by hydrophilically modifying the top surface of membrane using a plasma treatment to form polar groups for “excellent hydrophilicity” (see e.g. [0032]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the membrane of Suzuki by including an additive (the polar groups) by modifying the polymer of the membrane with a hydrophilic plasma treatment as taught in Shi to achieve excellent hydrophilicty. Shi additionally teaches that the film has been plasma oxidized to form polar groups attached to the polymer membrane surface that increases polarity of the surface of the porous polymer film (see e.g. Shi - [0032]), wherein the polymer is the high-density polyethylene (see e.g. Suzuki – [0049]; Higa -[0186]).
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki in view of Higa as applied to claim 1, and in further view of Chang et al (“Manipulating Membrane Hydrophobicity By Integrating Polythylene-Coated Fume Silica In Pvdf Membrane”, Asean Engineering Journal, Vol. 12 No. 1: March 2022).
Claim 16: Suzuki in view of Higa does not explicitly teach that the hydrophilic additive comprises a fumed silica. However, Suzuki does teach that the hydrophilic additive is an inorganic particle Group IV elements (see e.g. Suzuki - [0086]), which would include silicon materials. Chang teaches a means of adding hydrophilic properties to a membrane that includes polyethylene (see e.g. abstract), making it analogous art. See MPEP § 2141.01(a)I. In Chang, fumed silica is used as the hydrophilic inorganic particle (see e.g. abstract). MPEP § 2144.07 states ‘The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)’. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the membrane of Suzuki by using fumed silica as the hydrophilic inorganic material because it is a known hydrophilic inorganic material for membranes and satisfies the requirements of Suzuki.
Response to Arguments
Applicant's arguments filed 07/28/2026 have been fully considered but they are not persuasive.
On page(s) 5-6, the Applicant argues that there is no reason to modify Suzuki with Higa because Suzuki already discusses having a diagram with sufficient strength and there is no reason to combine with Higa. This is not considered persuasive. As stated in the previous Office Action, Suzuki does not explicitly teach a molecular weight required for the polyethylene. Therefore, even though Suzuki might discuss having a diaphragm with sufficient strength, the reference does not specify the molecular weight of polyethylene used and a person having ordinary skill in the art before the effective filing date of the instant invention would be motivated to find and use a suitable molecular weight polyethylene. Higa teaches an ultra-high molecular weight polyethylene having a molecular weight of 1,000,000 to 6,300,000 which “improves the durability of the resulting ion exchange membrane and also suppresses swellability” (see e.g. [0186]). A person having ordinary skill in the art before the effective filing date of the instant invention would therefore be motivated to use Higa as the polyethylene has good strength, which Suzuki discusses is a desired quality for the diaphragm.
On page(s) 7, the Applicant argues that Suzuki does not teach the claimed pore size of claim 21. This is not considered persuasive. Suzuki teaches that the porous polymer film has an average pore size of 0.5 microns (see e.g. [0020]), which is considered close to the claimed range of “less than 0.5 microns”. MPEP § 2144.05 I states ‘Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) ’.
On page(s) 7-8, the Applicant argues that Suzuki does not teach the thickness claimed in claim 22. This is considered persuasive. However, there is no rejection arguing that Suzuki teaches the thicknesses of claim 22.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan Van can be reached at 571-272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ALEXANDER W KEELING/Primary Examiner, Art Unit 1795
Prosecution Insights