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
2. The applicant’s response filed 26 May 2026 have been entered into the record. Claim 1 was amended and the examiner find basis for the claim amendments in the examples of the instant application since the porous substrate is applied to a glass slide prior to applying the dope solution which in effect prevents coating on the second side (as per the amendment). However, the applicant should expressly point out in the specification where the basis for the amendment pertaining to coating only the first side of the membrane can be found. Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20 are currently pending and under examination.
Claim Rejections - 35 USC § 102
3. The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
4. Claims 1, 2, 3, 4, 5, 7, 8, and 9 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Mues’811
Mues’811 (WO 2021/004811 A1) is directed toward a separator for alkaline hydrolysis (title).
Regarding Claim 1, Mues’811 discloses a porous-ion permeable (e.g.: transport of hydroxide ions in ¶6) asymmetric (i.e.: different diameter pores) composite membrane for electrolysis (title, abstract, and ¶10-13). Mues’811 further discloses the composite membrane comprises a porous support 10 (¶38-48) and a porous asymmetric polymer coating having a first side and a second side with the porous support only being coated on only a single surface (¶23: “coating at least one side”). Mues’811 indicates that the porous support has a pore size of 100 to 1000 microns or more preferred 300 to 700 microns (¶45). Mues’811 also indicates that the polymer coating comprising a polymer (e.g.: polysulfone in the examples in ¶135 and Table 1) and inorganic particles (e.g. ZrO2 in the comparative examples ¶129 and 130 and Table 1). The pore size of the portion of the membrane coated with the hydrophilic coating is 0.05 to 2 microns as per ¶31. The uncoated side (i.e.: the second side) will have a pore size of the support (i.e.: 100 to 1000 microns) and the coated side of the membrane (i.e.: the first side) will have a pore size of the hydrophilic coating (i.e.: 0.05 to 2 micros) resulting in an asymmetric pore size distribution. The previous description meets the limitation, “the polymer coating having an asymmetric pore distribution with pores having a first size adjacent to the porous substrate and pores having a size smaller than the first size adjacent to the second side.”
The porous substrate, the polymer, and the inorganic particles are inherently stable at a pH of 8 or higher according to Mues’811 since the reinforced separator is used for alkaline water electrolysis (title, abstract, ¶5, 6, 12, 13, and 20) and the separator facilitates the transport of hydroxide anion (¶6).
The amendment to Claim 1 requires that the second side of the porous substrate is not coated. This new limitation is anticipated by Mues’811. In particular, Mues’811 describes in ¶23 that the preferred separator is prepared by the application of the dope solution on at least one surface of a porous support which after phase inversion would deposit a hydrophilic coating on a single side of the porous support, a coating solution. The coating solution comprises a polymer resin, the barium sulfate particles and a solvent. The porous hydrophilic layer is then obtained after a phase inversion step wherein the polymer resin forms a three-dimensional porous polymer network. The application of the coating solution to at least one side meets the limitation of leaving the second side of the porous substrate uncoated since the preferred embodiment only requires one side to be coated.
Regarding Claim 2, Mues’811 discloses the membrane of Claim 1, wherein the polymer comprises any of the following: polyethersulfone (¶52), polysulfone (¶52) or PVDF (¶52-53). In the examples, Mues’811 uses polysulfone as the polymer (¶135).
Regarding Claim 3 and Claim 4, Mues’811 discloses the membrane of Claim 1, wherein the inorganic particle is zirconium oxide in the comparative examples (¶130, ¶131 and Table 1). The comparative examples have an ionic resistivity which is similar to the inventive examples.
Regarding Claim 5, Mues’811 discloses the membrane of Claim 1, wherein the inorganic particles comprise 10 wt.% to 90 wt.% of the polymer coating as evidenced by the comparative examples where the ratio of ZrO2 to polymer is 40.65 wt.% to 12.835 wt.% in the dope solution. Since the dope solution also contains liquids (e.g.: NEP and glycerol) which are not part of the deposited polymer coating, the comparative examples of Mues’811 explicitly teaches the inorganic particle is 76 wt.% of the polymer coating (Table 1). It has been held that a prima facie case of anticipation exists when an example from the prior art falls within the claimed range. See MPEP 2131.03(I) - A SPECIFIC EXAMPLE IN THE PRIOR ART WHICH IS WITHIN A CLAIMED RANGE ANTICIPATES THE RANGE.
Regarding Claims 7 and 8, Mues’811 discloses the membrane of Claim 1, wherein the porous substrate comprises polyphenylene sulfide (PPS), polyether-ether ketone (PEEK), polyethylene (PE), polypropylene (PP), copolymers of ethylene with tetrafluoroethylene (TFE) as indicated in ¶41 and PPS as per the examples (¶128 and Table 1).
Regarding Claim 9, Mues’811 discloses the membrane of Claim 1, wherein the polymer is different from the porous substrate as illustrated the examples where the polymer support is PPS and the polymer in the coating is polysulfone (¶128, ¶135, and Table 1).
5. Claims 10, 11, 13, 14, 15, 16, 17, 18, 19, and 20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Mues’785.
Mues’785 (US Pub. No. 2020/0181785 A1 – previously presented) is directed toward a reinforced separator for alkaline hydrolysis (title).
Regarding Claim 10, Mues’785 discloses a method of making a porous-ion permeable (i.e.: ion conductivity) asymmetric (i.e.: pore diameter different than each other) composite membrane for electrolysis (title and ¶22-26). Mues’785 further discloses the preparation of a dope solution in Ex. 1 which comprises mixing a polymer (e.g.: polysulfone), inorganic particles (e.g.: ZrO2), and a solvent (e.g.: NEP) where the polymer and the inorganic particles being stable at a pH of 8 or higher to form a membrane casting dope. The components of the dope (i.e.: the polymer and the inorganic particles) are stable at a pH of 8 or higher according to Mues’785 since the reinforced separator is used for alkaline water hydrolysis (title, abstract, ¶2-6, ¶22, and ¶51) and the separator facilitates the transport of hydroxide anion (¶12). Mues’785 teaches casting the membrane casting dope on a porous substrate to form a polymer coating on the porous substrate in ¶126 of Ex. 1 using a slot die coater. Further processing as described in ¶132-135 of Mues’785 teaches the polymer coating has an asymmetric pore distribution with pores having a first size adjacent to the porous substrate and pores having a size smaller than the first size adjacent to the second side. The porous substrate is stable at a pH of 8 or higher according to Mues’785 since it is used for alkaline water electrolysis. The last steps of Claim 10 are described in Mues’785 in ¶132-135 as the polymer coating on the porous substrate forms a wet membrane and annealing the wet membrane to form the stable porous ion-permeable asymmetric composite membrane.
Regarding Claim 11, Mues’785 discloses the method of Claim 10 further comprising: drying the porous ion-permeable asymmetric composite membrane after annealing the wet membrane as indicated in ¶95 and ¶107.
Regarding Claim 13, Mues’785 discloses the method of Claim 10 further comprising: removing the solvent from the polymer coating and the porous substrate before annealing the wet membrane as described in ¶126-135 where the slot-die coated support was placed into a hot water bath (i.e.: Liquid Induced Phase Separation) followed by exposure of the wet membrane to a hot and humid environment (i.e.: Vapor Induced Phase Separation).
Regarding Claim 14, Mues’785 discloses the method of Claim 10 where the wet membrane is annealed in a hot water bath at a temperature ranging from 40 and 70 degrees C (¶82). In Ex. 1, Mues’785 explicitly teaches a hot water coagulation bath of 65 degrees C (¶127). It has been held that a prima facie case of anticipation exists when an example from the prior art falls within the claimed range. See MPEP 2131.03(I) - A SPECIFIC EXAMPLE IN THE PRIOR ART WHICH IS WITHIN A CLAIMED RANGE ANTICIPATES THE RANGE.
Regarding Claim 15, Mues’785 discloses the method of Claim 10 wherein the solvent comprises NMP, DMAc, DMF, DMSO, or mixtures thereof as per ¶58.
Regarding Claim 16, Mues’785 discloses the method of Claim 10, wherein the polymer comprises any of the following: polyethersulfone (¶42), polysulfone (¶42) or PVDF (¶43). Example 1 of Mues’785 uses polysulfone as the polymer (¶124-5 in Table 1).
Regarding Claim 17, Mues’785 discloses the method of Claim 10, wherein the inorganic particle is zirconium oxide or titanium dioxide (¶46-50) and ZrO2 is used in the dope solution of Ex. 1 disclosed in Table 1 (¶124-125).
Regarding Claim 18, Mues’785 discloses the method of Claim 10, wherein the porous substrate comprises polyphenylene sulfide (PPS), polyether-ether ketone (PEEK), polyethylene (PE), polypropylene (PP), copolymers of ethylene with tetrafluoroethylene (TFE) as indicated in ¶33 and PPS as exemplified in Ex. 1 (¶126).
Regarding Claim 19, Mues’785 discloses the method of Claim 10, wherein the inorganic particles comprise 10 wt.% to 90 wt.% of the polymer coating as evidenced by Ex. 1 where the ratio of ZrO2 to polymer is 40.65 wt.% 12.835 wt.% in the dope solution. Since the dope solution also contains liquids (e.g.: NEP and glycerol) which are not part of the deposited polymer coating, Ex. 1 of Mues’785 explicitly teaches the inorganic particle is 76 wt.% of the polymer coating (¶124-125 in Table 1). It has been held that a prima facie case of anticipation exists when an example from the prior art falls within the claimed range. See MPEP 2131.03(I) - A SPECIFIC EXAMPLE IN THE PRIOR ART WHICH IS WITHIN A CLAIMED RANGE ANTICIPATES THE RANGE.
Regarding Claim 20, Mues’785 discloses the method of Claim 10, wherein the polymer is different from the porous substrate as illustrated by Ex. 1 where the polymer support is PPS and the polymer in the coating is polysulfone (¶109-114 and ¶124-126).
Claim Rejections - 35 USC § 103
6. 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.
7. 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.
8. Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Mues’811 as applied to Claim 1 above, and further in view of Epps et al.
Mues’811 (WO 2021/004811 A1) is directed toward a separator for alkaline hydrolysis (title). Epps et al. (“Pore Size and Air Permeability of Four Nonwoven Fabrics,” Int. Nonwovens J. 2000, Volume os-9, Issue 2 – previously presented) is directed toward the characterization of different fabrics (title).
Regarding Claim 6, Mues’811 discloses the membrane of Claim 1 wherein the porous substrate has an open area of at least 20% (¶44 with a broad range of 20% to 80% open area) with porous supports including polyphenylene sulfide (PPS) and polypropylene (PP) as per ¶42. Mues811 further discloses the PPS support of the examples has an open area of 60% (¶128). Mues’811 explains in ¶44 that sufficient open area is important to allow facile penetration of the electrolyte into porous separator during the electrolytic process of water hydrolysis. However, Mues’811 does not specify an air permeance of 0.5 ft3/ft2/min or more for the porous support.
Epps et al. characterizes various measurements pertaining to fabrics including polypropylene. In Table 2, Epps et al. characterizes the open area (i.e.: porosity) and the air permeance (i.e.: air permeability) of two samples of polypropylene (Samples C and D). Epps et al. is related to Mues’811 since both references use polypropylene as supports/fabric material. The two PP samples of Epps et al. have an open area of ~80% (similar to range suggested by Mues’811) and an air permeability of 38.66 cm3/cm2/s for Sample C and 13.86 cm3/cm2/s for Sample D. When the air permeabilities of Sample C and D are converted to the units of Claim 6, the resultant quantities are 7.6 ft3/ft2/min for Sample C and 2.7 ft3/ft2/min for Sample D.
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the porous support of Mues’811 by substituting the PP fabric disclosed by Epps et al. with the reasonable expectation of forming a porous membrane that has sufficient open area and air permeance to allow facile penetration of the electrolyte into said membrane.
It has been held that a prima facie case of obviousness exists when the prior art discloses a range that overlaps with the claimed range. See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
9. Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Mues’785 as applied to Claim 11 and further in view of Koseoglu-Imer et al.
Mues’785 (US Pub. No. 2020/0181785 A1 – previously presented) is directed toward a reinforced separator for alkaline hydrolysis (title). Koseoglu-Imer et al. (“The determination of performances of polysulfone (PS) ultrafiltration membranes fabricated at different evaporation temperatures for the pretreatment of textile wastewater,” Desalination 2013, 316, 110-119 – previously presented) is directed toward the processing of PS membranes (pg. 110: title).
Regarding Claim 12, Mues’785 discloses the method of Claim 11 that includes a drying step in ¶95 and ¶107. However, Mues’785 does not explicitly state the drying temperature of the composite membrane. One of ordinary skill in the art of membrane production would understand that the drying temperature of the wet membrane will affect the properties of the resultant polymer coating on the porous support as such careful selection of the drying temperature is required.
Koseoglu-Imer et al. discloses different evaporation temperatures that are applied for drying a polysulfone membrane (pg. 110: abstract) and how they impact physical properties. The temperatures evaluated were 25, 35, 45, 55, and 65 degrees Celsius and were characterized by water permeability, porosity, surface roughness, and contact angle (pg. 110: abstract). Koseoglu-Imer et al. found that lower temperatures resulted in higher porosity (Fig. 1 on pg. 113) and high permeability (pg. 116: Table 3) while higher evaporation temperatures resulted in a more robust membrane that was more resistant to fouling (pg. 118-119: Conclusion) and had a lower roughness (pg. 115: Figure 2 and pg. 116: Table 2). The water contact angle (i.e.: hydrophilicity) was independent of dry temperature (pg. 116: Table 3 and pg. 118-119: Conclusion). Therefore, Koseoglu-Imer et al. teaches a drying temperature range of 25 degrees Celsius to 65 degrees Celsius.
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the drying procedure of Mues’785 by using the temperature range disclosed by Koseoglu-Imer et al. with the reasonable expectation of forming a more robust membrane for alkaline water electrolysis by using a higher temperature (i.e.: 45 to 65 degrees Celsius).
It has been held that a prima facie case of obviousness exists when the prior art discloses a range that overlaps with the claimed range. See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
Response to Arguments
10. The applicant’s arguments filed 26 May 2026 have been considered and are persuasive for Claims 1, 2, 3, 4, 5, 6, 7, 8, and 9, but are not persuasive for Claims 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20.
11. Pertaining to Claim 10, the applicant has alleged on pg. 7-8 of their response that the that the coating layer is only applied to the first side of the porous support and that the asymmetry in the pore size be present throughout the thickness of the membrane; however, the examiner does not find this argument persuasive. The limitations of Claim 10 do not expressly exclude applying the dope solution to the both sides of the porous substrate as is taught in Mues’785. Additionally, the asymmetry in pore size is not expressly listed as being different throughout the thickness of the membrane. Rather the limitations of Claim 10 explicitly state “the polymer coating having an asymmetric pore distribution with pores having a first size adjacent to the porous substrate and pores having a size smaller than the first size adjacent to the second side” which is accomplished by applying the dope solution to both sides of the porous substrate and forming different size pores based on the further processing in the phase inversion step as explained in ¶132-135 of Mues’785. Therefore, the anticipation rejection of Claim 10 in view of Mues’785 is maintained. The previous rejections of dependent Claims 11, 12, 13, 14, 15, 15, 16, 17, 18, 19, and 20 are also maintained under either 102 or 103.
12. The amendment to Claim 1 has required that the polymer coating is only applied to one side of the porous substrate and the second side remains uncoated. The examiner finds the applicant’s arguments on pg. 6-7 of their response that Mues’785 expressly requires the dope solution is applied to both sides of the porous substrate, therefore, the anticipation rejection of Claim 1 in view of Mues’785 is withdrawn. However, new grounds for rejection of Claim 1 and dependent Claims 2, 3, 4, 5, 6, 7, 8, and 9 in view of Mues’811 as the primary reference are presented in detail above.
Conclusion
13. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
14. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN SYLVESTER whose telephone number is (703)756-5536. The examiner can normally be reached Mon - Fri 8:15 AM to 4:30 PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at (571)272-8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/JAMES LIN/Supervisory Patent Examiner, Art Unit 1794
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