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 06/29/2026.
Status of Rejections
The rejection(s) of claim(s) 44 is/are obviated by applicant’s cancellation.
All other previous rejections are maintained and modified only in response to the amendments to the claims.
Claims 1-4, 6-9, 11-21, 43 and 45-47 are pending and under consideration for this Office Action.
Claim Objections
Claim 43 is objected to because of the following informalities:
In claim 43, lines 13-14, “than 11 wherein” should read “than 11, wherein”.
Appropriate correction is required.
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.
Claims 1-4, 6-9, 11-14, 16-21, 43 and 45-47 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaki et al. (U.S. 2019/0040537).
Regarding claim 1, Yamaki teaches a multilayer cation exchange membrane for use in a chloralkali process (see e.g. Paragraph 0010, lines 4-8, ion exchange membrane for alkali chloride electrolysis comprising layers C and S) comprising a fluorinated ionomer containing carboxylate groups on one side of the membrane (see e.g. Fig. 1, bottom layer (C) 12 made of fluorinated polymer having carboxylic acid functional groups; Paragraph 0046, lines 5-7), an exterior sulfonate layer comprising a fluorinated ionomer containing sulfonate groups on the side of the membrane opposite the carboxylate layer (see e.g. Fig. 1, top layer (Sb) 14B made of fluorinated polymer having sulfonic acid functional groups; Paragraph 0078, lines 5-7, and Paragraph 0079, lines 7-11), and an interior sulfonate layer comprising a fluorinated ionomer containing sulfonate groups between the carboxylate layer and the exterior sulfonate layer (see e.g. Fig. 1, middle layer (Sa) 14A made of fluorinated polymer having sulfonic acid functional groups; Paragraph 0078, lines 5-7, and Paragraph 0079, lines 3-7), the exterior sulfonate layer having an ion exchange ratio of 3.12 to 15.34, with a specific example of 13.12 (see e.g. Paragraphs 0090 and 0231, and Table 1, Example 6, layer Sb with preferable ion exchange capacities from 0.9 to 2.00 meq/g, which equates to an IXR of 3.12-15.34, and with Example 6 having a value of 1.0 meq/g, which equates to 13.12, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formula 50IXR+344=EW for the first sulfonate type described on Page 11 of the instant specification and exemplified in Paragraph 0111 and Example 1 of Yamaki), and the interior sulfonate layer having an ion exchange ratio of 9.79 to 15.34, with a specific example of 11.3 (see e.g. Paragraph 0086, lines 1-3, and Paragraph 0231, and Table 1, Example 6, layer Sa with most preferable ion exchange capacities from 0.9 to 1.2 meq/g, which equates to an IXR of 9.79-15.34, and with Example 6 having a value of 1.1 meq/g, which equates to an IXR of 11.3, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formula 50IXR+344=EW for the first sulfonate type described on Page 11 of the instant specification and exemplified in Paragraph 0111 and Example 1 of Yamaki), overlapping the claimed ranges of the present invention, the specific example for the exterior sulfonate layer falling within the claimed range and the specific example for the interior sulfonate layer being very close to, only 0.3 from, the claimed range.
MPEP § 2144.05 I 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” and further 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.”.
Regarding claim 2, Yamaki teaches the interior sulfonate layer having an ion exchange ratio less than the ion exchange ratio of the exterior sulfonate layer by up to 5.55 (above calculated layer Sb IXR range of 3.12 to 15.34 greater than the above layer Sa IXR range of 9.79 to 15.34, by at most 5.55), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above), with a specific example of 1.82 (above calculated example of 13.12 for layer Sb and 11.3 for layer Sa).
Regarding claim 3, Yamaki teaches the carboxylate layer having an IXR of 12.0 to 14.9 or 14.3 to 17.2 (see e.g. Paragraph 0052 and Paragraph 0065 and 0071, layer C with most preferable ion exchange capacities from 0.95 to 1.10 meq/g, which equates to an IXR of 12-14.9 or 14.3-17.2, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formulas 50IXR+308=EW or 50IXR+192=EW for the specific carboxylate polymers types described on Page 11 of the instant specification and Exemplified in Paragraphs 0065 and 0071 and Example 1 of Yamaki), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above), with particular examples of 14.68 and 15.3 (see e.g. Paragraph 0208 and Paragraph 0231, polymer C with monomer of formula Y having an IEC of 1.08 or 1.06 meq/g, equal to IXR of 14.68 and 15.3, respectively, based on the 2nd carboxylate equation conversion).
Regarding claims 4 and 6-8, Yamaki teaches the exterior sulfonate layer having an ion exchange ratio of 3.12 to 15.34, with a specific example of 13.12 (see e.g. Paragraphs 0090 and 0231, and Table 1, Example 6, layer Sb with preferable ion exchange capacities from 0.9 to 2.00 meq/g, which equates to an IXR of 3.12-15.34, and with Example 6 having a value of 1.0 meq/g, which equates to 13.12, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formula 50IXR+344=EW for the first sulfonate type described on Page 11 of the instant specification and exemplified in Paragraph 0111 and Example 1 of Yamaki), overlapping or encompassing the claimed ranges of the present invention, the specific example falling within or being very close to the claimed ranges (see MPEP § 2144.05 I as cited above).
Regarding claims 9 and 11-12, Yamaki teaches the interior sulfonate layer having an ion exchange ratio of 9.79 to 15.34, with a specific example of 11.3 (see e.g. Paragraph 0086, lines 1-3, and Paragraph 0231, and Table 1, Example 6, layer Sa with most preferable ion exchange capacities from 0.9 to 1.2 meq/g, which equates to an IXR of 9.79-15.34, and with Example 6 having a value of 1.1 meq/g, which equates to an IXR of 11.3, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formula 50IXR+344=EW for the first sulfonate type described on Page 11 of the instant specification and exemplified in Paragraph 0111 and Example 1 of Yamaki), overlapping or encompassing the claimed ranges of the present invention, the specific example again being very close to, only 0.3 or 0.4 from, the claimed ranges (see MPEP § 2144.05 I as cited above).
Regarding claim 13, Yamaki teaches the membrane further comprising a woven fabric reinforcement (see e.g. Fig. 1, reinforcing material 20 comprising fabric composed of warp and weft, i.e. woven, threads; Paragraph 0134).
Regarding claim 14, Yamaki teaches the woven fabric reinforcement being embedded in the membrane (see e.g. Fig. 1, reinforcing material 20 embedded in layer (S) 14; Paragraph 0045, lines 2-3).
Regarding claim 16, Yamaki teaches the interior sulfonate layer having a thickness of at least 40 micrometers (see e.g. Paragraph 0083, lines 1-4, layer Sa thickness preferably 40-140 µm, more preferably 40-90 µm).
Regarding claims 17-18, Yamaki teaches the interior sulfonate layer having a thickness of 40 to 90 micrometers (see e.g. Paragraph 0083, lines 1-4), overlapping the claimed ranges of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claims 19-21, Yamaki teaches the exterior sulfonate layer having a thickness of 10 to 40 micrometers (see e.g. Paragraph 0088, lines 1-4), overlapping the claimed ranges of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 43, Yamaki teaches a multilayer cation exchange membrane for use in a chloralkali process (see e.g. Paragraph 0010, lines 4-8, ion exchange membrane for alkali chloride electrolysis comprising layers C and S) comprising a fluorinated ionomer containing carboxylate groups on one side of the membrane (see e.g. Figs. 1-2, bottom layer (C) 12 made of fluorinated polymer having carboxylic acid functional groups; Paragraph 0046, lines 5-7), an exterior sulfonate layer comprising a fluorinated ionomer containing sulfonate groups on the side of the membrane opposite the carboxylate layer (see e.g. Figs. 1-2, top layer (Sb) 14B made of fluorinated polymer having sulfonic acid functional groups; Paragraph 0078, lines 5-7, and Paragraph 0079, lines 7-11), and first and second interior sulfonate layers comprising fluorinated ionomer containing sulfonate groups between the carboxylate layer and the exterior sulfonate layer (see e.g. Fig. 2, middle layers (Sa-1) 14Aa and (Sa-2) 14Ab making up layer 14A made of fluorinated polymer having sulfonic acid functional groups; Paragraph 0078, lines 5-7, and Paragraph 0126, lines 1-5), the first interior sulfonate layer being between the carboxylate layer and the second interior sulfonate layer (see e.g. Fig. 2, layer 14Aa between layers C and 14Ab) and the second interior sulfonate layer being between the first interior sulfonate layer and the exterior sulfonate layer (see e.g. Fig. 2, layer 14Ab between layers 14Aa and 14B), the exterior sulfonate layer having an ion exchange ratio of 3.12 to 12.17 (see e.g. Paragraph 0090, layer Sb with most preferable ion exchange capacities from 1.05 to 2.00 meq/g, which equates to an IXR of 3.12-12.17, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formula 50IXR+344=EW for the first sulfonate type described on Page 11 of the instant specification and exemplified in Paragraph 0111 and Example 1 of Yamaki), the first interior sulfonate layer having an ion exchange ratio of 12.17 to 15.34 (see e.g. Paragraph 0127, lines 1-4, layer 14Aa with most preferable ion exchange capacities from 0.9 to 1.05 meq/g, which equates to an IXR of 12.17-15.34, calculated as above), and the second interior sulfonate layer having an ion exchange ratio of 7.93 to 14.63 (see e.g. Paragraph 0126, lines 6-11, and Paragraph 0127, lines 1-4, layer 14Ab with ion exchange capacity preferably 0.03 to 0.3 meq/g greater than the 0.9 to 1.05 meq/g of layer 14Aa, resulting in an IEC range of 0.93 to 1.35 meq/g, which equates to an IXR of 7.93-14.63, calculated as above), falling within or overlapping the claimed ranges of the present invention (see MPEP § 2144.05 I as cited above), wherein the second interior sulfonate layer has an ion exchange ratio less than the ion exchange ratio of the exterior sulfonate layer by up to 4.24 (above calculated layer Sb/14B IXR range of 3.12 to 12.17 greater than the above layer 14Ab IXR range of 7.93 to 14.63, by at most 4.24), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 45, Yamaki teaches the first interior sulfonate layer having an ion exchange ratio greater than the ion exchange ratio of the second interior sulfonate layer by 0.71 to 4.23 (see e.g. Paragraph 0126, lines 6-11, and Paragraph 0127, lines 1-4, layer 14Ab with ion exchange capacity preferably 0.03 to 0.3 meq/g greater than the 0.9 to 1.05 meq/g of layer 14Aa, resulting in an IEC range of 0.93 to 1.35 meq/g, which results in an IXR of 14Aa greater than that of 14Ab by 0.71 to 4.23), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 46, Yamaki teaches the carboxylate layer having an IXR of 12.0 to 14.9 or 14.3 to 17.2 (see e.g. Paragraph 0052 and Paragraph 0065 and 0071, layer C with most preferably ion exchange capacities from 0.95 to 1.10 meq/g, which equates to an IXR of 12-14.9 or 14.3-17.2, based on the IEC converted to EW by 1000 divided by C, as described on Page 3 of the instant specification, and EW converted to IXR based on the formulas 50IXR+308=EW or 50IXR+192=EW for the specific carboxylate polymers types described on Page 11 of the instant specification), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above), with particular examples of 14.68 and 15.3 (see e.g. Paragraph 0208 and Paragraph 0231, polymer C with monomer of formula Y having an IEC of 1.08 or 1.06 meq/g, equal to IXR of 14.68 and 15.3, respectively, based on the 2nd carboxylate equation conversion).
Regarding claim 47, Yamaki teaches the first interior sulfonate layer having an ion exchange ratio that differs from the ion exchange ratio of the carboxylate layer by 0.66 to 3.13 (above calculated exemplary layer C IXR of 14.68 and 15.3 which differ from any point in the 12.17-15.34 IXR range of layer 14Aa by 0.66 to 3.13).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Yamaki in view of Suzuki et al. (U.S. Patent No. 4,872,958).
Regarding claim 15, Yamaki teaches all the elements of the membrane of claim 13 as stated above. Yamaki does not explicitly teach the woven fabric comprising fluoropolymer yarns having a denier less than 100, only exemplifying fluoropolymer yarns of exactly 100 denier (see e.g. Paragraph 0136 and Paragraph 0213, lines 1-4, 100 denier PTFE threads) being used with a sacrificial PET yarns of 30 denier (see e.g. Paragraph 0213, lines 4-6).
Suzuki teaches an ion exchange membrane for electrolysis (see e.g. Abstract) comprising a woven or knitted fabric as a support including a reinforcing material comprising fluoropolymer yarns which preferably have a fineness of 50 to 200 denier (see e.g. Col. 6, lines 25-35 and 40-44), overlapping the denier value of Yamaki as well as the claimed range of the present invention (see MPEP § 2144.05 I as cited above), with a particular example of a woven fabric comprising 75 denier PTFE yarns and 30 denier PET yarns (see e.g. Col. 12, lines 64-67).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the fluoropolymer yarns of Yamaki to have a denier of preferably 50 to 200, particularly 75, as taught by Suzuki as a suitable fineness for reinforcing fluoropolymer yarns in a supporting woven fabric for an ion exchange membrane for electrolysis. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results. Furthermore, MPEP § 2143(I)(B) states that “simple substitution of one known element for another to obtain predictable results” may be obvious.
Response to Arguments
Applicant's arguments filed 06/29/2026 have been fully considered but they are not persuasive.
On pages 6-7, Applicant argues that Yamaki does not disclose or suggest the multiple sulfonate layers with different IXR values across the membrane where their spatial ordering relative to the IXRs affects performance, specifically that Yamaki has no identified teaching regarding the relative positioning of the layers with the claimed IXRs affecting performance, no suggestion of arranging multiple sulfonate layers in the claimed sequence, and no rationale for selecting the claimed configuration among possible arrangements. This is not considered persuasive. The fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Yamaki teaches the structure of exterior sulfonate layer having an ion exchange ratio of 3.12 to 15.34, with a specific example of 13.12 (see e.g. Yamaki Fig. 1 and Paragraphs 0090 and 0231, and Table 1, Example 6, outer layer Sb/14B with preferable ion exchange capacities from 0.9 to 2.00 meq/g, which equates to an IXR of 3.12-15.34, and with Example 6 having a value of 1.0 meq/g, which equates to 13.12, calculated as described above in the rejections), and the interior sulfonate layer having an ion exchange ratio of 9.79 to 15.34, with a specific example of 11.3 (see e.g. Yamaki Fig. 1 and Paragraph 0086, lines 1-3, and Paragraph 0231, and Table 1, Example 6, inner layer Sa/14A with most preferable ion exchange capacities from 0.9 to 1.2 meq/g, which equates to an IXR of 9.79-15.34, and with Example 6 having a value of 1.1 meq/g, which equates to an IXR of 11.3, calculated as described above in the rejections), overlapping the claimed ranges of the present invention, the specific example for the exterior sulfonate layer falling within the claimed range and the specific example for the interior sulfonate layer being very close to, only 0.3 from, the claimed range (see MPEP § 2144.05 I as cited above). Yamaki therefore teaches and/or makes obvious all the structural limitations of the claimed membranes, particularly with the example of the two sulfonate layers of the specified arrangement with the required or very close to the required IXR values.
On pages 7-8, Applicant argues that Yamaki does not recognize the element of the ordered arrangement of sulfonate layers having the claimed IXR ranges as affecting performance, i.e. being a results-effective variable, and therefore routine optimization or overlapping ranges cannot be used to establish obviousness. This is not considered persuasive. The rejections over Yamaki were not based on routine optimization and are therefore not required to recognize a results-effective variable. Furthermore, obviousness of overlapping/close ranges, which the rejection was based on, does not require recognition of a results-effective variable (see MPEP § 2144.05 I).
On page 8, Applicant argues that the comparative example demonstrated a structural-functional relationship for membranes with identical IXR values exhibiting different performance based on the positioning of the interior and exterior sulfonate layers, and the assertion that the example does not demonstrate performance across the IXR range imposes an improper evidentiary burden, as applicant is not required to test every embodiment within a clamed range. This is not considered persuasive. As previously stated, the comparative example shows the benefit of a lower IXR for the interior sulfonate layer, but does not necessarily show that the specific IXR ranges are critical. To show that the claimed range is critical, Applicant must generally show that it achieves unexpected results relative to the prior art range. MPEP §716.02(d) states “To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range.” Though the comparative example provides a data point for the order of the layers inside the claimed IXR range, there is no evidence outside the claimed range pointing to criticality of the specific IXR values in combination with the order of the layers. Therefore, a prima facie case of obviousness still exists especially in light of the specific example of Yamaki which exhibits the supposed beneficial spatial IXR relationship and has IXR values that fall within or are very close to the claimed ranges (see e.g. Yamaki Fig. 1 and Table 1, Example 6, outer layer Sb/14B with IEC of 1.0 meq/g and inner layer Sa/14A with IEC of 1.1, which equate to IXRs of 13.12 and 11.3, respectively, as calculated in the rejection above).
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.
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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