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 .
Terminal Disclaimer
The terminal disclaimer filed on 10/02/2025 disclaiming the terminal portion of any patent granted on this application which would extend beyond the expiration date of over claims 1-6 of copending Application No. 17/980826 has been reviewed and is accepted. The terminal disclaimer has been recorded.
Status of Claims
Claim 1 is amended. Claim 8 is cancelled. Claim 11 is new. Claims 1-7 and 9-11 are pending.
Status of Previous Rejections
The rejections of Claims 1-4, 6 and 9-10 under 35 U.S.C. 103 as being unpatentable over Kakoki (US 2018/0025820) have been withdrawn in view of the amendment.
The rejections of Claims 1-10 under 35 U.S.C. 103 as being unpatentable over Sakuma (US 2014/0238553), and further in view of Kakoki (US 2018/0025820) are maintained.
The ODP rejections over claims 1-6 of copending Application No. 17/980826 have been withdrawn in view of the terminal disclaimer filed on 10/02/2025.
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 1-7 and 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Sakuma (US 2014/0238553), and further in view of Kakoki (US 2018/0025820).
Regarding claims 1, 5 and 7, Sakuma teaches a hot-deformed R-T-B magnet, wherein in a cross-section of the R-T-B based permanent magnet which is approximately parallel to an easy magnetization axis direction of the R-T-B based permanent magnet, the plurality of main phase grains are flat, and an average value of a length of a short axis of the plurality of main phase grains is from 20 nm to 200 nm, and the plurality of main phase grains are stacked along an easy magnetization direction of the magnet ([0060]; [0061]; Fig. 6(a)). Sakuma discloses a molded body is formed by hot deforming a sintered R-T-B magnet and grain boundary diffusion of heavy rare earth elements is performed on the molded body to improve coercivity ([0030] to [0032]). Sakuma does not explicitly teach the recited void ratio in claim 1.
Kakoki teaches an R-T-B based permanent magnet contains a plurality of main phase grains and a plurality of voids ([0016] to [0030]). Kakoki discloses that when performing grain boundary diffusion of heavy rare earth metal, a part of heavy rare earth elements is trapped in the void and the heavy rare earth element trapped in the void does not contribute to the improvement of coercive force, and it is impossible to achieve the improvement of coercive force to an extent to be expected from the amount of heavy rare earth element used and thus the cost-effectiveness is lowered ([0003]). Kakoki further discloses that before diffusion of heavy rare earth elements, the area ratio of the plurality of voids in an arbitrary cross-section of the R-T-B based permanent magnet is 0.2% or less to reduce the amount of trapped heavy rare earth element ([0028; [0029]). Thus, it would be obvious to one of ordinary skill in the art to make a magnet having area ratio of voids being 0.2 % or less before diffusion of heavy rare earth elements as taught by Kakoki in the process of Sakuma in order to make a magnet having high coercivity in a cost-effective way. The area ratio of voids disclosed by Kakoki is very close to the recited area ratio of the voids in claim 1. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). Thus, claim 1 is obvious over Sakuma in view of Kakoki. See MPEP 2144.05 I.
Regarding claim 2, Sakuma in view of Kakoki discloses that an average value of an area of each of the plurality of voids in the arbitrary cross-section of the R-T-B based permanent magnet is from 0.7 μm2 or less ([0031] of Kakoki), which overlaps the recited value in claim 2. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Thus, claim 2 is obvious over Sakuma in view of Kakoki.
Regarding claim 3, Sakuma in view of Kakoki discloses an example containing two voids having area of 5.72 µm2 and 4.22 µm2 (Fig. 2A of Kakoki, the voids are surrounded by solid circles; the area of the voids are measured by the Examiner). The calculated standard deviation is 1.06 µm2, which meets the standard deviation recited in claim 3.
Regarding claim 4, Sakuma in view of Kakoki does not explicitly disclose a correlation coefficient r of x and y. Kakoki discloses that the voids in the sintered magnet are present at the multiparticle grain boundaries ([0028]), which is same as the location disclosed in the instant Specification. One of ordinary skill in the art would expect that a correlation coefficient r of x and y in Sakuma in view of Kakoki meets the limitation that r is from 0 to 0.2 recited in claim 4. “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.” In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP 2112.01 I.
Regarding claims 6 and 9, Sakuma discloses an example that contains 13.64 at% Nd, 0.19 at% Pr and 5.47 at B, 75.66 at% Fe, 4.47 at% Cu and 0.57 at% Ga ([0075]), which converts to 30.21 wt% Nd+Pr and 0.88 wt% B ([0075]) and meets the limitation recited in claim 6. Since the magnet disclosed by Sakuma contains 13.83 at% rare earth element which is greater that the stoichiometric amount of rare earth content in R2T14B structure, the presence of R-rich grain boundary phase is expected by one of ordinary skill in the art. Thus, claim 9 is met by Sakuma in view of Kakoki.
Regarding claim 10, Sakuma in view of Kakoki discloses that the average value of LL/Ls is about 1.1 (Fig. 2A of Kakoki), which meets the limitation recited in claim 10.
Regarding claim 11, Kakoki further discloses that before diffusion of heavy rare earth elements, the area ratio of the plurality of voids in an arbitrary cross-section of the R-T-B based permanent magnet is 0.2% or less ([0028; [0029]). The area ratio of voids disclosed by Kakoki is close to the recited area ratio of the voids in claim 11. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). Thus, claim 11 is obvious over Sakuma in view of Kakoki. See MPEP 2144.05 I.
Claims 1, 6, 9 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over JP’938 (JPH05-135938A).
Regarding claims 1 and 11, JP’938 teaches a hot-deformed R-T-B magnet having columnar crystal structure (which meets a plurality of main phase grains limitation), wherein in a cross-section of the R-T-B based permanent magnet, a porosity of the magnet is 2% or less (Abstract; Page 6; Table 1), which overlaps the recited area ratio of voids in claims 1 and 11. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Thus, claims 1 and 11 are obvious over JP’938.
Regarding claims 6 and 9, JP’938 discloses that the magnet has a composition of Pr15Fe80B5 by at% (Table 1, Example 1), which converts to 31.855 wt% Pr, 0.815 wt% B and 67.33 wt% Fe and meets the recited composition in claim 6. Since the magnet disclosed by JP’938 contains 15 at% rare earth element which is greater that the stoichiometric amount of rare earth content in R2T14B structure, the presence of R-rich grain boundary phase is expected by one of ordinary skill in the art. Thus, claim 9 is obvious over JP’938.
Response to Arguments
Applicant's arguments filed 10/02/2025 have been fully considered but they are not persuasive.
First the applicants argued that Kakoki discloses an upper limit of 0.2% for the total area ratio of voids, which is outside the range recited in claim 1 (larger than 0.2% and 2% or smaller). Accordingly, the range of the total area ratio of voids disclosed by Kakoki does not overlap the range recited in claim 1 as asserted by the Office Action.
In response, Kakoki further discloses that before diffusion of heavy rare earth elements, the area ratio of the plurality of voids in an arbitrary cross-section of the R-T-B based permanent magnet is 0.2% or less ([0028; [0029]). The area ratio of voids disclosed by Kakoki is close to the recited area ratio of the voids in claim 11. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). Thus, claim 11 is obvious over Sakuma in view of Kakoki. See MPEP 2144.05 I.
Second, the applicants argued that Kakoki teaches that fewer voids are preferable to increase the coercivity of the magnet and that the total area ratio of voids in the cross section of the magnet is 0.2% or less to increase the coercivity. Kakoki teaches away from the range of the area ratio of voids recited in claim 1 (larger than 0.2% and 2% or smaller).
In response, Kakoki discloses that the area ratio of voids is 0.2% or less. Instant claim 1 recites greater than 0.2%, which includes a scope that the area ratio is 0.20000001%. One of ordinary skill in the art would expect that measuring an area ratio of voids has experimental error and the experimental error is significantly greater than 0.00000001%. It would be obvious to one of ordinary skill in the art that a 0.00000001% difference in void ratio would not change the magnet coercivity. A magnet containing 0.2% voids is not different in properties from a magnet containing 0.20000001% voids.
Third, the applicants argued that as shown in [0089] of the present specification, Examples 1-10, which have an area ratio of voids being larger than 0.2% and 2% or smaller, exhibit higher coercivity than Comparative Example 2, which has an area ratio of voids being less than 0.2%. This higher coercivity is an unexpected result to a person having ordinary skill in the art because Kakoki teaches that the total area ratio of voids is 0.2% or less to increase coercivity as explained above.
In response, Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the “objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support.” In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). See MPEP 716.02(d) II and MPEP 2144.05 III.
Claim 1 recites an area ratio of greater than 0.2% and 2% or smaller. The only comparative example containing void ratio less than the lower limit of the recited range is Comparative Example 2 which has void ratio of 0.115%. There is no evidence that when the void ratio is 2%, high coercivity can’t be achieved. Thus, unexpected results have not been established over the entire claimed range and the argument that the claimed area ratio of porosity has unexpected results is not persuasive.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 Xiaowei Su whose telephone number is (571)272-3239. The examiner can normally be reached 8:00-5:00.
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/XIAOWEI SU/Primary Examiner, Art Unit 1733