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 .
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on July 29, 2026 has been entered.
Claims 1-2, 4-5, and 7-17 are pending as amended on July 29, 2026. Support for amended claim 1 is found in lines 10-18 of page 12 of the instant specification.
Any objections and/or rejections made in the previous Office action and not repeated below are hereby withdrawn. The text of those sections of Title 35, U.S. Code not included in the action can be found in a prior Office action.
Response to Arguments
Applicant’s arguments, see page 1-3, filed July 29, 2026, with respect to the rejections of claims 1-2, 4-5, 7-9, and 11-14 under 35 U.S.C. 102(a)(1) have been fully considered and are persuasive. Hwang (WO 2019/160218 A1) does not teach the amended second solvent and Lee (KR 101988809 B1) does not teach the amended second solvent. Therefore, the rejections have been withdrawn. However, upon further consideration, new grounds of rejection are made in view of Kandanarachchi (US 2020/0283579 A1), Ohya (US 2011/0318556 A1), and Itoh (US-2005/0238896-A1).
Applicant argues (page 3-4) that the specific solvent species recited in amended claim 1 have unexpectedly beneficial properties. Applicant points to Examples 2-6 and Comparative Examples 1-5. These examples differ in that the second solvents used in Examples 2-6 are recited in claim 1 and the second solvents used in Comparative Examples 1-5 are not recited in claim 1. In particular, the solvents used in the comparative examples have boiling points above 150 °C (see Table 1 footnotes) and are not listed as specific second solvents in claim 1. The claimed second solvents all have boiling points below 150 °C. Applicant states that Examples 2-6 have lower viscosities and CTE values and higher glass transition temperatures and thermal decomposition temperatures than the comparative examples.
Applicant’s arguments are not persuasive because Applicant has not shown unexpected results that are commensurate in scope with the claimed invention. Evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support. See MPEP 716.02(d). In addition, Examples 2-6 are not commensurate in scope with claim 1 at least because claim 1 does not limit the polyamic acid chemistry, solids content, identity of the first solvent, and amount of each solvent. In addition, claim 1 is open to additional components. If Applicant wishes to overcome the present rejection by showing unexpected results, Applicant must provide sufficient evidence to show that unexpected results would be obtained for all species and the full breath of ranges encompassed by the claims.
Claim Rejections - 35 USC § 102
Claims 1, 2, 5, and 8-9 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kandanarachchi (US 2020/0283579 A1).
Regarding claims 1, 2, and 8-9, Kandanarachchi discloses dissolving polyamic acid containing N-methyl-2-pyrrolidone (NMP) in propylene glycol monomethyl ether acetate (PGMEA) to obtain a 29 wt. % solution ([0183], see [0083] and [0153] for acronym definitions). The polyamic acid is a copolymer of 5,5'-(perfluoropropane-2,2-diyl)bis(isobenzofuran-1,3-dione) (6FDA); 4,4'-([1,1'-biphenyl]-4,4'-diylbis(oxy))bis(3-(trifluoromethyl)aniline) (6BF); bicyclo[2.2.1]heptane-2,5-diyldimethanamine (NBDA); and NH2-1-(2-aminoethyl)-3,4-dimethyl-1H-pyrrole-2,5-dione (DMMIEt-NH2) ([0183]).
This composition reads on a polyamic acid composition comprising polyamic acid including a dianhydride monomer component (6FDA and 6BF) and a diamine monomer component (NBDA) as a polymerization unit and a solvent, wherein the solvent includes a first solvent having a boiling point of about 202 °C (NMP) and a second solvent having a boiling point lower than that of the first solvent wherein the second solvent comprises PGMEA. PGMEA has a boiling point of about 146 °C (claims 1-2). A 29 wt. % polyamic acid solution reads on a solids content of 29% (claim 9). The dianhydride monomer includes 6-FDA (claim 8).
Regarding claim 5, Kandanarachchi discloses the polyamic acid composition of claim 1. The instant specification states that some of the dianhydride monomer is ring-opened by the organic solvent and thus is not able to participate in the polymerization reaction (instant specification, page 5, lines 19-20). As organic solvents, the instant specification exemplifies, for example, a mixture of NMP and PGMEA (see instant Example 6). Given that Kandanarachchi uses the same combination of organic solvents as the instant application, there is reasonable basis to conclude that there is necessarily at least some amount of unpolymerized monomer having a ring-opening structure included in the dianhydride monomer.
Claims 1-2, 4-5, and 7-8, are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ohya (US 2011/0318556 A1).
Regarding claims 1-2 and 7-8, Ohya discloses a polyamic acid solution composition where the acid component is s-BPDA and the diamine component is ODA (Referential Example 6 in Table 1 on page 11). ODA and s-BPDA are reacted in NMP. Benzoic acid and additional s-BPDA are added later followed by an ethyl acetate solution containing 50% by mass polyvinyl acetate ([0112-0114]). The solution is then filtered to obtain a viscous polyamic acid solution composition ([0112]).
This composition reads on a polyamic acid composition comprising polyamic acid including a dianhydride monomer component (s-BPDA) and a diamine monomer component (ODA) as a polymerization unit and a solvent, wherein the solvent includes a first solvent having a boiling point of about 202 °C (NMP) and a second solvent having a boiling point lower than that of the first solvent wherein the second solvent comprises ethyl acetate. Ethyl acetate has a boiling point of about 77 °C (claims 1-2). The diamine monomer includes ODA and the dianhydride monomer includes s-BPDA (claims 7-8).
Regarding claim 4, Ohya teaches the polyamic acid composition of claim 1. The polymer concentration after reacting s-BPDA and ODA is about 6.5% by mass in NMP (Table 1 and [0112]). This corresponds to about 100 parts polyamic acid and about 1440 parts NMP ((100-6.5)/6.5=14.4). About 50 parts by mass of benzoic acid and about 8 parts by mass of polyvinyl acetate are added based on 100 parts by mass of the polyamic acid (Table 1). Because polyvinyl acetate is added in a 50/50 polyvinyl acetate/ethyl acetate solution, the composition also comprises 8 parts by mass of ethyl acetate. The total mass of the composition is approximately 1606 parts (100+1440+50+8+8=1606), making the ethyl acetate content about 0.5 wt% in the entire polyamic acid composition (8/1606=0.00498).
Regarding claim 5, Ohya discloses the polyamic acid composition of claim 1. The instant specification states that some of the dianhydride monomer is ring-opened by the organic solvent and thus is not able to participate in the polymerization reaction (instant specification, page 5, lines 19-20). As organic solvents, the instant specification exemplifies, for example, a mixture of NMP and ethyl acetate (see instant Example 2). Given that Ohya uses the same combination of organic solvents as the instant application, there is reasonable basis to conclude that there is necessarily at least some amount of unpolymerized monomer having a ring-opening structure included in the dianhydride monomer.
Claim Rejections - 35 USC § 103
Claims 10 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Ohya (US 2011/0318556 A1) as applied to claim 1 above.
Regarding claim 10, Ohya teaches the polyamic acid composition of claim 1. Ohya further teaches that from the viewpoints of easiness of casting and film strength, the viscosity can be 10 to 10,000 poises ([0089]). This range corresponds to 1,000-1,000,000 cP. The viscosity is measured at 30 °C ([0110]).
Ohya does not teach that the claimed measurement conditions.
However, one of ordinary skill would expect the range taught by Ohya to overlap with the claimed range. The temperature taught by Ohya is very close to claimed measurement temperature of 23 °C. In addition, Ohya’s measured viscosity encompasses almost all of the claimed range of 500-50,000 cP and extends well above the claimed range. There is reasonable basis to conclude that if measured at a temperature of 23 °C and a shear rate of 1 s-1, Ohya’s range of 1,000-1,000,000 cP would overlap with the claimed range of 500-50,000 cP. It would have been obvious to one of ordinary skill in the art prior to the effective filing date to have selected any viscosity taught by Ohya, including one within the claimed range. Ohya’s viscosity range overlaps with the claimed range of 500-50,000 cP. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 14, Ohya teaches the polyamic acid composition of claim 1. Ohya further teaches thermally treating the polyamic acid solution to obtain a polyimide ([0116]). The resulting polyimide reads on the polyamic acid composition after curing.
Ohya is silent as to the glass transition temperature (Tg) after curing.
However, Ohya teaches polyamic acid compositions that would necessarily be capable of producing the claimed Tg. Ohya teaches that the diamine component can be 1,4-diaminobenzene (PPD) ([0057]). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have prepared the polyamic acid composition as in Ohya’s Referential Example 6 where the ODA of Referential Example 6 is substituted for PPD because Ohya teaches that the diamine can be PPD. Ohya therefore discloses a substantially similar composition prepared in a substantially similar manner as the instant invention.
Ohya’s composition comprises a polyamic acid derived from PPD and BPDA in NMP and ethyl acetate. Instant example 2 is most similar to Ohya because the polyamic acid is derived from PPD and BPDA and the solvent is NMP and ethyl acetate (instant Table 1). The instant solids content is not specified. Instant example 2 produces a Tg of 470 °C after curing (instant Table 2). The other instant examples based on a polyamic acid derived from PPD and BPDA do not use ethyl acetate as a secondary solvent, but have Tg values of 466 °C and 336 °C (instant example 1 and comparative example 1 in Tables 1-2). This means that all of the instant examples derived from PPD and BPDA satisfy the claimed Tg, even without the claimed second solvent. Because Ohya discloses a similar composition prepared in a similar manner and no evidence has been provided of a composition based on PPD and BPDA that does not achieve the claimed Tg, there is reasonable basis to conclude that Ohya’s composition is capable of producing a Tg of 300 °C or more after curing.
Claims 1-2, 5, 7-8, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Itoh (US-2005/0238896-A1).
Regarding claims 1-2 and 7-8, Itoh teaches a polyamic acid solution comprising a polyamic acid derived from a dianhydride component and a diamine component ([0018]). The dianhydride component comprises at least pyromellitic dianhydride (claim 8) and the diamine component comprises at least p-phenylenediamine and 4,4’-diamino-diphenyl ether (claim 7) ([0018]). The solvent can be N,N-dimethylformamide, N-N-dimethylacetamide, or N-methyl-2-pyrrolidone ([0046]). All three of these solvents have boiling points above150 °C (about 153 °C, 165 °C and 202 °C, respectively). The solvent may further comprise another solvent that can be ethyl acetate ([0046]). Ethyl acetate has a boiling point of 77 °C (claims 1-2). The solids content is 15-25 wt% (claim 9) ([0047]).
Regarding claim 5, Itoh teaches the polyamic acid composition of claim 1. The instant specification states that some of the dianhydride monomer is ring-opened by the organic solvent and thus is not able to participate in the polymerization reaction (instant specification, page 5, lines 19-20). As organic solvents, the instant specification exemplifies, for example, a mixture of NMP and ethyl acetate (see instant Example 2). Given that Itoh uses the same combination of organic solvents as the instant application, there is reasonable basis to conclude that there is necessarily at least some amount of unpolymerized monomer having a ring-opening structure included in the dianhydride monomer.
Regarding claim 13, Itoh teaches the polyamic acid composition of claim 1. Itoh further teaches that the upper limit of the coefficient of linear expansion of a polyimide film produced from the polyamic acid composition is 25 ppm in a range of 100-200 °C ([0086-0087]). This corresponds to a CTE within the claimed range 40 ppm/ °C or less after curing. In particular, although Itoh uses units of ppm rather than ppm/ °C, the recited value must be within the range because it is measured over a 100 °C range.
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Itoh (US-2005/0238896-A1) as applied to claim 1 above, and further in view of Lee (KR 101988809 B1, US 20220010070 A1 is used as an English translation).
Regarding claim 11, Itoh teaches the polyamic acid composition of claim 1.
Itoh does not specify the Mw after curing.
However, Lee teaches that a polyimide Mw of 50,000-100,000 g/mol is desirable for achieving excellent adhesion (Lee, [0093]). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have prepared a polyamic acid composition according to Itoh capable of curing to a Mw in the range of 50,000-100,000 taught by Lee in order to achieve excellent adhesion.
Regarding claim 12, Itoh teaches the polyamic acid composition of claim 1. The composition can contain inorganic fillers ([0084]).
Itoh does not explicitly teach that the inorganic fillers are inorganic particles.
However, Lee teaches fillers that improve polyimide resins properties such as sliding properties, thermal conductivity, and loop hardness (Lee, [0063]). Lee teaches fillers such as silica titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, and mica with an average particle diameter of 0.05 µm to 100 µm ([0063-0065)]. Lee’s fillers read inorganic particles. It would have been obvious to one of ordinary skill in the art prior to the effective filing date to have substituted the inorganic filler of Itoh with the specific inorganic fillers of Lee in order to improve the sliding properties, thermal conductivity, and loop hardness of the resulting polyimide films.
Conclusion
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/AUDRA J DESTEFANO/Examiner, Art Unit 1766
/RANDY P GULAKOWSKI/Supervisory Patent Examiner, Art Unit 1766
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