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 .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-7, in the reply filed on 5/27/2026 is acknowledged. Group II, claims 8-20, is withdrawn from examination. Because Applicant did not traverse the restriction requirement, it is hereby deemed proper and made FINAL.
Claim Rejections - 35 USC § 112
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.
Claims 1-7 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim 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.
Claim 1 recites: “An R-T-B based magnet comprising”. This limitation is indefinite because the claim does not indicate what ‘T’ is. For purposes of examination, it is presumed to include Fe. Dependent claims depend from an indefinite claim and are indefinite for the same reason.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Lan et al. (CN 116564638).
Regarding claim 1, Lan teaches a R-T-B magnet that contains R, Fe, and B (p. 1, ¶ 7). R includes a light rare earth element and a heavy rare earth element (p. 1, ¶ 8). The heavy rare earth element is chosen from one or more of Dy, Tb, Ho, and Gd (p. 3, ¶ 13). The magnet contains main phase grain A, main phase grain B, and their respective grain boundary phases (p. 1, ¶ 10). The grain boundary phases are present between main phase grains (p. 1, ¶ 11) and correspond to the claimed intergranular phase. The main phases A and B exhibit core-shell structures (p. 2, ¶¶ 2&5). Lan teaches numerous examples (see Table 5-2, Inv.Ex. 1, 3-8, 10 & Comp.Ex. 1-2) where the RH content in the grain boundary phase (RHCB) and the RH content in the main phase grain B shell (RHB2) satisfy the claimed relationship of RH1-RH2≥2.6wt% and/or RH1/RH2≥1.5. The RH contents measured by Lan are taken from a region at a depth of 100 μm (see p. 2, ¶¶ 1-8), which is “within a region that extends 200 μm inward from the surface” as claimed, and represents a region perpendicular to the diffusion direction.
Regarding claim 2, Lan does not teach or suggest the presence of other grain phases. Accordingly, one of ordinary skill in the art would expect the main phase grains A&B to represent about 100% of the proportion of grains absent objective evidence to the contrary. See MPEP 2112.
Regarding claim 3, Lan teaches the RH content in the shell RHB2 is greater than the RH content in core RHB1 (p. 2, ¶ 16 – p. 3, ¶ 2). Lan also teaches RHB2 is 1%-15% wt, with exemplary contents above 2.0% wt (p. 3, ¶ 1; see also Table 5-2, Inv.Ex. 1, 3-8, 10 & Comp.Ex. 1-2).
Regarding claims 4-5, the area of the microstructure observation surface or shape has no impact on the RH contents of the boundary phase B or the main phase grain B and is considered to be inherent to the disclosure of Lan absent objective evidence to the contrary. See MPEP 2112.
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.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Lan et al. (CN 116564638), as applied to claim 1.
Regarding claim 6, the limitations of claim 1 have been addressed above. Lan teaches the composition of the magnet includes 28%-30.5% light rare earth metals which are Pr and/or Nd, 0%-3% Dy, 0%-1.5% Tb, 0%-1.1% Ga, 0%-0.8% Cu, 0%-1.0% Al, 0.5%-1.5% Co, 0.9%-1.0% B, and 0.05%-0.15% Ti, 0.15%-0.2% Nb, and 0.05%-0.2% Zr, with Fe balance (pp. 3-4). This overlaps the claimed range, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Lan et al. (CN 116564638), as applied to claim 1, further in view of Hayakawa (US 2024/0321491).
Regarding claim 7, the limitations of claim 1 have been addressed above. Lan teaches a remanence of at least 13.4 kGs and an intrinsic coercivity (Hcj) of at least 25.86 kOe (p. 7, ¶ 15). Lan does not teach a ratio of knee point coercivity (Hk) to intrinsic coercivity being not less than 94%. Hayakawa teaches a Hk/Hcj ratio of at least 93%, preferably at least 95% (¶ 121). It would have been obvious at the effective time of filing for the claimed invention for one of ordinary skill in the art to ensure the R-T-B magnet of Lan has a Hk/Hcj of at least 95% to ensure the magnet resists demagnetization.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Li (US 2024/0055163) teaches a R-T-B magnet having a RH content in the grain boundary greater than the RH content in the shell of the core-shell grains, but does not teach or suggest the claimed relationship. Shi (CN 114360831) discloses a R-T-B magnet which undergoes a diffusion treatment similar to the diffusion treatment for making the claimed magnet, but does not teach or suggest the tempering treatment for making the claimed magnet.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to XIAOBEI WANG whose telephone number is (571)270-5705. The examiner can normally be reached M-F 8AM-5PM EST.
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/XIAOBEI WANG/Primary Examiner, Art Unit 1784
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