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 .
Continued Examination Under 37 CFR 1.114
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 1/12/2026 has been entered.
The previous prior art rejection under Ejima et al. (JP 2007112927), in view of Yamaguchi et al. (US 20020052463) and Ungerank et al. (US 20150166730), cited in previous Office Action in view of Yamaguchi et al. maintained.
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.
Claims 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over by Ejima et al
(JP 2007112927), in view of Yamaguchi et al. (US 20020052463) both cited in previous Office Action
Claims 1-3 and 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Ungerank et al. (US 20150166730), cited in previous Office Action in view of Yamaguchi et al.
Amendment to claims 1 and 6 are noted.
Yamaguchi teaches a process for production of a polyimide powder molded body, whereby polyimide powder according to claim 6 is packed into a die and subjected to heat in a range of about 300-600° C. and pressure in a range of about 100-10,000 Kg/cm2 either simultaneously or separately for molding (see claim 8).
The reference discloses that very high mechanical properties were achieved.
In particular, the tensile strength was 900 Kg/cm, the tensile break elongation was 20%, the flexural strength was 1100 Kg/cm and the flexural modulus was 33,000 Kg/cm2 (see 0050).
Therefore, it would have been obvious to a person of ordinary skills in the art before the effective filing date of the invention to use Yamaguchi’s method of sintering, including unpressurised firing procedure, since it produces a molding body with very high mechanical properties.
The rejection can be found in the FINAL office action mailed 10/15/2025 and is herein incorporated by reference.
Response to Arguments
Applicant's arguments filed 1/12/2026 have been fully considered but they are not persuasive.
Applicant submits that Ejima and Yamaguchi do not teach unpressurised firing after uniaxially pressing a powder.
Examiner disagrees. Yamaguchi teaches that polyimide powder was packed into a die for pre-molding at room temperature and a pressure of 200 Kg/cm’, and after removing the pre-molded body from the die and free sintering at 410 C for 30 minutes (see Example 1 at 0050).
Applicant argues that the references fail to teach non-esterified 2,3,3',4'-biphenyl tetracarboxylic dianhydride (BPDA) component.
However, claims 1 and 6 recite “an aromatic polyimide containing a unit derived from 2,3, 3’, 4’ biphenyl tetracarboxylic dianhydride. “ In other words, the claim recites a polyimide containing BPDA residue in its backbone.
Note that the polyimide structures are identical in cases where they formed by the reaction of unmodified BPDA or its half ester (as disclosed by Yamaguchi). The reference prefer polycondensation using BPDA half ester solely for the reason of better process workability (see Yamaguchi at 0009).
In the instant case substitution of equivalent methods requires no express motivation, as long as the prior art recognizes equivalency, In re Fount 213 USPQ 532 (CCPA 1982); In re Siebentritt 152 USPQ 618 (CCPA 1967); Graver Tank & Mfg. Co. Inc. V. Linde Air products Co. 85 USPQ 328 (USSC 1950)
Therefore, it would have been obvious to a person of ordinary skills in the art before the effective filing date of the invention to use either non-modified or partially esterified BPDA in polyimide synthesis unless unexpected results are demonstrated.
Applicant demonstrates unexpected results stating that polyimide powders having amount of volatiles outside of the claimed range show significantly lower flexural strengths (see Tables 1-3).
However, Ejima et al (JP 2007112927) teaches amount of volatile component is equal to 1.6 % wt (see Example 1) and Ungerank teaches the volatile content was 0.99% by mass (see 0095). Both cited documents represent primary references and positively disclose volatiles within claimed range. Thus, presenting unexpected results does not applicable in this case.
Applicant states that the residual solvent content in Table 5 of Endoh is not the residual solvent content of the polyether imide powder, but is the residual solvent content of the carbon fiber sheet impregnated with polyether imide.
Examiner agrees. As a result, rejection under 35 U.S.C. 103 over Endoh et al. (US 6054177) in view of Yamaguchi et al. is withdrawn.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to GREGORY LISTVOYB whose telephone number is (571)272-6105. The examiner can normally be reached 9am-5pm EST M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Heidi Riviere Kelley can be reached at (571) 270-1831. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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GL
/GREGORY LISTVOYB/Primary Examiner, Art Unit 1765