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 .
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 27 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claim 27, no support is found in the specification for the permeability and selectivity measurement conditions of 35 oC and 2 atm. Specification Table 5 (page 33) shows temperature of 22 oC and pressures from 500 to 900 psi (34 to 61 atm). The claimed measurement requirements should comply with the description as present in the specification.
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.
Claim 1 and dependent claims 4, 15-17 and 22-27 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as failing to set forth 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 claim 1, the claim language is indefinite, since the claim does not clearly set forth the metes and bounds of the patent protection desired. Applicant requires structures (I) and (II), these structures are followed by the “wherein requirement of random copolyimide comprising (i) and (ii)”, which is lastly followed by the “and wherein…. the repeat units of Formula (I) and Formula (II) are in the molar ratio of about 3:1”. Since “and/or” are missing before the first “wherein” clause, it is unclear if the structures (i) and (ii) are required for the molar ratio calculation of Formula (I): Formula (II) of about 3:1. Appropriate correction and clarification is required.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 17 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 17 requires the structures (I-B) and (II-B) which are the same as (i) and (ii) of claim 1 and therefore does not further limit the requirements of claim 1.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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.
Claims 1, 4, 15, 17 and 22-27 are rejected under 35 U.S.C. 103 as being unpatentable over Yahaya et al. US 2018/0345229 A1 and in view of Wu et al. Synthesis and properties of cardo-type polyimides containing hydroxyl groups for application in specific detection of fluoride ion, Dyes and Pigments 173, 2020, 107924.
Yahaya teaches co-polyimide membranes for separating components of sour natural gas where embodiments can include at least three distinct moieties polymerized together, the moieties including a 2,2' -bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) based moiety; a 9,9-bis(4-aminophenyl) fluorene (CARDO) based moiety; and 2,3,5,6-tetramethyl-1,4-phenylenediamine (durene diamine) based moiety (Abstract and reference claim 1).
Reference Wu teaches synthesis and properties of cardo-type polyimides containing hydroxyl groups (Title) which can be used for gas separation membranes (page 4, 2nd col, last sentence of 2nd para).
Regarding claims 1, 4, 17 and 22-23, Yahaya discloses a random co-polyimide 6FDA-durene/6FDA-CARDO (3:1) with the molar ratio of the durene diamine based moiety to the CARDO based moiety of 3:1, which is utilized for the preparation of a membrane (instant claim 23) which will result in structural backbone repeat unit corresponding to Formula (I) to Formula (II) in a molar ratio of about 3:1 (para [0047], page 5 Table 1, 1st entry, reference claim 3), with the absence of R3 and R4. The structure of the repeat units are presented in reference Figure 1 as depicted below.
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Yahaya is silent on the presence of specific -OH substitution on the fluorene moiety (R3 and R4) as required by the claims, however highlights that various chemical modifications including substitution of pertinent moieties can be carried out to improve the performance of co-polyimides (paras 15, 16 and 33). Yahaya additionally guides a skilled artisan to functionalize the copolyimide moieties with polar functional groups to manage crosslinking of the polymers in order to enhance the separation performance and optimize copolyimides for gas separation (paras [0015]-[0016] and [0018]).
A person having ordinary skill in the art would look to analogous copolyimide art which employs polar functional groups to further optimize the polyimide properties. Reference Wu teaches substantially similar cardo-type polyimides containing hydroxyl groups (Title and Abstract), and discloses copolyimide such as PI-3 which is derived from monomers 9,9-bis(4-aminophenyl)-2,7-dihydroxy-fluorene (AHF) and 6FDA, as shown (page 3, Fig 2 (c)):
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Advantageously, Wu provides the motivation for incorporating hydroxyl polar groups into the polyimide chains as it helps to improve solubility, thermal and mechanical properties since the hydroxyl groups provide strong intermolecular associations through forming H-bond interactions (Introduction, second para).
It would be obvious to combine Yahaya in view of Wu where in the random co-polyimide 6FDA-durene/6FDA-CARDO (3:1), the CARDO units are substituted with hydroxyl groups at the same position as taught by Wu. Such a co-polymer meets the claimed requirements structural repeat units corresponding to Formulae (I),(i),(I-B), (II), (ii), co(II-B), where X and Y are C (CF3)2, A is phenylene substituted with four methyl groups, such that R5 is methyl (instant claim 4) and n=4, R3 and R4 are -OH, a and b=0, and where the structural repeat units of Formula (I) (or (i) 6FDA-durene repeat unit or (I-B)) and the Formula (II) (or (ii) 6FDA-2,7-dihydroxy-CARDO repeat unit or (II-B)) are present in a molar ratio of 3:1 (instant claims 17 and 22).
It would have been obvious to one of ordinary skilled in the art before the effective filing date of the invention to have substituted Yahaya’s CARDO based moieties with polar hydroxyl substituents as taught by Wu for the same application of creating copolyimides with improved thermal and mechanical properties.
Regarding claim 15, Yahaya teaches block copolymer 6FDA-durene)/(6FDA-CARDO)(15,000)/(15,000), such that the total Mn would be 30,000 (para [0052]). Obvious composition of Yahaya in view of Wu, would be such that the copolymer as discussed when addressing claim 1 is adjusted to have Mn of 30,000, thus making the claimed requirement obvious.
Regarding claim 24, Yahaya teaches the creation of co-polyimide membrane where the film is solution cast, and dried under vacuum at elevated temperature to remove any residual solvent, thereby generating a membrane with almost 100 wt% of the polymer, which meets the claimed requirement (Yahaya para [0055]).
Regarding claims 25-26, Yahaya teaches the membrane and the method for separating the components of a sour natural gas feed (see reference claims 1 and 11). Yahaya further discloses that the feed gas is passed through the membrane at different gas feed pressure, and that the simulated sour gas consists of 10 vol % of both CO2 and H2S in the feed gas prior to passing the membrane, making the claimed requirement obvious (para [0062] and Table 7, with 10 vol% H2S).
Regarding claim 27, the obvious random copolyimide of Yahaya in view of Wu, as discussed when addressing claim 1, would be reasonably expected to satisfy the claimed permeability and selectivity, since the prior art’s polymer structure is identical to that of the claims. See MPEP 2112.01 I.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Yahaya in view of Wu, as applied to claim 1 above, and further in view of Blinka et al. US 5,042,992.
Regarding claim 16, Yahaya in view of Wu is silent on the number-average molecular weight of the copolyimide per the claimed limitation. Yahaya highlights the use of the co-polyimides based membranes for gas separation (Title and Abstract). Yahaya further notes that various modifications and changes can be made within the scope of the disclosure (para [0073]). In order to optimize the performance of the gas separation membrane a skilled artisan would seek guidance from analogous art such as Blinka which also teaches polyimide based semipermeable membranes (Abstract). Blinka recommends a molecular weight in the range of 30,000-500,000, as the specified range of molecular weight is more suited in preparing gas separation membranes as compared to lower molecular weight polyimides which are useful for films, adhesives or coatings (col 3, lines 20-27).
It would have been obvious to one of ordinary skilled in the art before the effective filing date of the invention to have adjusted the number molecular weight of the copolyimide of Yahaya in view of Wu to 100,000 g/mol as taught by Blinka (which is within Blinka’s recommended range) for the same application of creating membranes which are suited for gas separation.
Response to Arguments
Applicant's arguments filed on 05/04/2026 have been fully considered but they are not persuasive.
Applicant reiterates (page 7 of 9, first para) that primary reference Yahaya does not disclose or exemplify any hydroxyl-substituted CARDO diamines. Applicant adds that functional group modification would not lead to the specific hydroxyl-functionalized CARDO monomer. As discussed in the rejection while it is acknowledged that Yahaya does not specify a hydroxy substituted CARDO monomer, Yahaya provides appropriate guidance for an artisan skilled in the art to chemically modify with functional groups which include polar groups to manage the crosslinking of the co-polyimides by including substitution of pertinent moieties to optimize copolyimides to enhance their gas separation performance (paras 15, 16, 18, 33). This would encourage a skilled practitioner in the art to sought out similar CARDO based copolyimides such as disclosed by Wu, which employ polar functional groups to optimize the polyimide properties. Since Wu teaches the specific 2,7-dihydroxy-fluorene based CARDO, the specific position of dihydroxyl substitution on CARDO diamine would be rendered obvious.
Applicant further argues (page 7 of 9, second para) that the secondary reference Wu does not cure the deficiencies of Yahaya. Wu’s polymers are binary polyimides and not durene/CARDO copolymers and Wu does not suggest formation of random copolyimides with the desired molar monomer ratio. In response it is emphasized that primary reference teaches the desired copolyimide backbone with the desired molar ratio of monomers, as discussed in the main rejection. Yahaya’s embodiment random co-polyimide 6FDA-durene/6FDA-CARDO (3:1) (page 5 Table 1, 1st entry and claim 3) serves as the starting polyimide copolymer which lacks -OH substitution on the CARDO monomer. Secondary reference Wu is utilized to only teach the desired hydroxyl substituents with appropriate motivation to improve thermal and mechanical properties where the hydroxyl groups provide strong intermolecular associations to the polyimide chains (Wu, Introduction). One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant notes that the combination of Yahaya and Wu requires impressible hindsight (page 7 of 9, third para) and selecting a particular copolyimide of Yahaya would not be obvious. In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). In the instant case, as discussed above selecting 6FDA-durene/6FDA-CARDO (3:1) embodiment as disclosed in Yahaya’s claim 3 and first entry of Table 1, would have been obvious to a person having ordinary skill in the art.
Applicant discusses that (page 8 of 9, first para) that claim 1 has been amended to overcome Yahaya’s disclosure of multiple ratios across a wide composition space, in the absence of a critical or preferred ratio. While Yahaya provides a few different monomer ratios, Yahaya highlights the ratio of durene diamine to CARDO molar ratio of 3:1 in claim 3, as well as the first entry in Table 1. Applicant’s attention is directed to: "The use of patents as references is not limited to what the patentees describe as their own inventions or to the problems with which they are concerned. They are part of the literature of the art, relevant for all they contain." In re Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 (Fed. Cir. 1983). In the instant case, as discussed above selecting 6FDA-durene/6FDA-CARDO (3:1) would have been obvious to a person having ordinary skill in the art, as a way to introduce fluorenyl units into the polyimide backbone to improve membrane separation performance (Yahaya para [0019]).
Applicant finally notes (page 8 of 9 , second para) that claim 1 is amended to require the specific copolymer architecture actually exemplified in the application to establish a nexus between the claimed structural feature and the demonstrated gas separation. Applicant’s amendments are acknowledged, however applicant is reminded the claimed structure is a random copolyimide while all the applicant’s examples are block copolymers. Since the combination of Yahaya and Wu generate the random copolyimide with durene diamine and 2,7-dihydroxy substituted CARDO diamine in the required monomer ratio, it would be expected to demonstrate the desired gas-separation performance.
Applicant’s arguments against both Yahaya and Wu are found to be unconvincing. References Yahaya and Wu (and Blinka) continue to provide the foundation for maintaining the rejection of the amended claims.
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 Surbhi M Du whose telephone number is (571)272-9960. The examiner can normally be reached M-F 9:00 am to 5:00pm.
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/HEIDI R KELLEY/ Supervisory Patent Examiner, Art Unit 1765
/S.M.D./
Examiner
Art Unit 1765
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