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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 12/26/2025 has been entered.
Response to Arguments
Applicant’s arguments, see Remarks filed 12/26/2025, with respect to the 35 U.S.C. 102 and 103 rejections over Yamaguchi et al. (JP 2007-177260) as evidenced by Okada have been fully considered and are persuasive. The rejections are withdrawn.
Applicant’s arguments with respect to the 35 U.S.C. 103 rejection over Yamaguchi in view of Kwon et al. (US 2021/0202143) as evidenced by Okada have been fully considered but are not persuasive. Applicant makes the following arguments:
A) Yamaguchi does not disclose mullite. Yamaguchi is not relied upon to disclose mullite. Yamaguchi discloses examples where an additional layer of colloidal silica and alumina sol are applied on the steel and baked at 900-1050°C (p. 4, ¶¶ 4-6). Okada evidences that baking colloidal silica and alumina sol up to 1100°C forms mullite (§ 2). Applicant has not presented any evidence to rebut the presumption of inherency that mullite forms in Yamaguchi based on the disclosure of Okada. See MPEP 2112.
B) When Al2O3 and SiO2 are added separately, reactivity between Al2O3 and SiO2 is low. Applicant has provided no evidence to support this statement. Attorney argument is not evidence. See MPEP 2145. Even assuming this statement is correct, Yamaguchi teaches mixing the Al2O3 and SiO2 (p. 4, ¶ 4), not adding them separately. Thus, this argument is not persuasive.
C) The Al2O3 and SiO2 of Yamaguchi remain unreacted or form Al-Mg or Si-Mg compounds. Applicant has provided no evidence to support this statement. Attorney argument is not evidence. See MPEP 2145. This argument is not persuasive.
D) The Al2O3 and SiO2 of Yamaguchi correspond to the claimed ceramic layer, not the claimed mullite and forsterite coating. As stated previously, the Al2O3 and SiO2 of Yamaguchi form mullite. Kwon is relied upon to teach the claimed ceramic layer. Moreover, the Al2O3 and SiO2 in Yamaguchi take the form of colloidal silica and alumina sol (p. 4, ¶¶ 4-6). Applicant has presented no evidence that a layer made from these materials results in a ceramic layer. Accordingly, Applicant’s argument is not persuasive.
E) Okada does not disclose synthesizing mullite from Al2O3. This argument is not persuasive. Applicant argues Okada discloses synthesizing mullite from an Al source which is not Al2O3. However, the compounds Applicant identifies (see Remarks, p. 6) are the compounds for obtaining alumina (see §§ 2, 3.1, 3.2, Table 1). Okada clearly states mullite fibers are made by sol-gel method using colloidal silica and alumina sol (§ 1). Applicant has not rebutted the presumption of inherency which serves as the basis for the prior art rejections. Accordingly, the rejections are maintained.
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 7-10 and 14-16 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi et al. (JP 2007-177260) in view of Kwon et al. (US 2021/0202143), as evidenced by Okada et al. (“Sol-Gel synthesis of mullite long fibres from water solvent systems”).
Regarding claim 7, Yamaguchi discloses a grain-oriented electrical steel sheet (p. 1, ¶ 1). The surface of the steel sheet includes forsterite (p. 2, ¶ 2) as part of an annealing separator (p. 2, ¶ 3). Yamaguchi discloses examples where an additional layer of colloidal silica and alumina sol are applied on the steel and baked at 900-1050°C (p. 4, ¶¶ 4-6). As evidenced by Okada, baking colloidal silica and alumina sol up to 1100°C forms mullite (§ 2). Accordingly, the coating on the steel sheet of Yamaguchi includes both mullite and forsterite.
Yamaguchi does not expressly disclose a ceramic layer formed on the coating. Kwon teaches a grain-oriented electrical steel sheet (¶ 1) having an annealing separator comprising forsterite on top of which is a ceramic layer (¶ 13). It would have been obvious at the effective time of filing for the claimed invention for one of ordinary skill in the art to form a ceramic layer on the annealing separator of Yamaguchi, as taught by Kwon, because the ceramic layer improves the magnetic characteristics of the electrical steel sheet (¶ 138). Kwon further teaches the ceramic layer is made of ceramic powder (¶ 21), and includes Al2O3, SiO2, TiO2, ZrO2, Al2O3·TiO2, Y2O3, 9Al2O3·2B2O3, BN, CrN, BaTiO3, SiC, and TiC (¶ 23).
Regarding claim 8, Yamaguchi teaches the additional layer formed from colloidal silica and alumina contains 20% to 80% Al2O3 (see Table 2), which corresponds to 10.2%-42% Al. The overall amount of Al in the coating is less than this amount, which overlaps the claimed range, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding claim 9, based on the amount of Al2O3 (see discussion of claim 8 above), the additional layer contains 20%-80% SiO2, which corresponds to 9.3%-37% Si. The amount of O in the additional layer is the balance and is 48.7%-52.8%. As the coating also contains forsterite (Mg₂SiO₄), one of ordinary skill in the art would expect the amounts of Si, Mg, and O+Fe to overlap the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding claim 10, Yamaguchi teaches the thickness of the coating on the steel sheet is 0.3-10 μm (p. 4, ¶ 2), which lies within the claimed range.
Regarding claim 14, Kwon teaches the ceramic layer includes a metal phosphate (¶ 25).
Regarding claim 15, Kwon teaches the metal phosphate is one of Mg, Ca, Ba, Sr, Zn, Al, and Mn (¶ 26).
Regarding claim 16, Kwon teaches the steel sheet comprises 2.6% to 5.5% Si, 0.020% to 0.040% Al, 0.01% to 0.20% Mn, and 0.01% to 0.15% Sb or Sn, and a remainder of Fe and other unavoidable impurities (¶ 27).
Conclusion
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/XIAOBEI WANG/Primary Examiner, Art Unit 1784