DETAILED ACTION
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Any rejections made in a previous Office action and not repeated below are hereby withdrawn.
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 .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Hunold et al. (US 4,495,123).
Regarding claims 1 and 2, Hunold discloses a hexagonal boron nitride powder having a purity of at least 98.5% by weight, see abstract and col. 3 lines 13-26. The reference further discloses the powder as granulated with small amounts of temporary binder, which corresponds to agglomerated particles formed by an agglomeration of hexagonal boron nitride, see col. 3 lines 32-42.
Additionally, the reference discloses that the boron nitride powder has free carbon in an amount that does not exceed about 0.1% by weight, based on the boron nitride, see col. 3 lines 54-60. Although relatively large amounts of free carbon do not interfere with the densification process during the subsequent isostatic hot-pressing, they may cause a discoloration of the end product which is usually white, as follows from the known designation of boron nitride as "white graphite"; see col. 3 lines 60-65. While the reference does not specifically disclose the claimed number of particles of carbon per 10 g of the boron nitride powder, it would have been obvious to one of ordinary skill in the art at the time of the invention to minimize the amount of carbon in order to prevent discoloration of the end product; see MPEP 2144.05 II discovering the optimum or workable ranges involves only routine skill in the art, absent a showing of criticality.
Regarding claim 3, the reference discloses the amount of carbon does not exceed about 0.1% by weight boron nitride, which renders obvious the claimed range, see col. 3 lines 54-60; see also MPEP 2144.05 I regarding overlapping ranges.
Claims 4 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Hunold et al. (US 4,495,123) as applied to claim 1 above, and further in view of Takaki et al. (JP 2018-104253).
Hunold discloses the boron nitride powder of claim 1, see above discussion.
Regarding claim 4, the reference, however, fails to disclose the claimed graphitization index. Regarding claim 5, while the reference discloses a specific surface area of 5 to 30 m2/g, which overlaps the claimed range, the reference fails to disclose the claimed particle size, see abstract; see also MPEP 2144.05 I.
Takaki discloses aggregates of primary hexagonal boron nitride particles with a mean particle size of 10 microns or more and 200 microns or less and a graphitization index (GI) of 1.8 or more and 2.2 or less, both of which overlap the claimed range [0010]; see MPEP 2144.05 I regarding overlapping ranges.
Additionally, the reference discloses that when the GI is more than 2.2, the crystallinity of the primary particles of hexagonal boron nitride is low, so that a high thermal conductivity may not be obtained [0020]. On the other hand, when the GI is less than 1.8, it may be difficult to maintain aggregation structure [0020].
The reference further discloses than when the particle size is decreases, the thermal conductivity tends to decrease [0024]. However, as particle size increases, the mechanical strength of the aggregate tends to decrease [0024]. As such, the average particle size is 10 microns or more and 200 microns or less.
It would have been obvious to one of ordinary skill in the art at the time of the invention for the powder of Hunold to have the particle size and graphitization index of Takaki in order to maintain the integrity of the aggregated particles without causing a decrease in thermal conductivity.
Response to Arguments
Regarding the rejections under 35 U.S.C. 112, Applicant’s arguments, see pages 2-3, filed February 10, 2026, with respect to claims 1-5 have been fully considered and are persuasive. The rejection of claims 1-5 under 35 U.S.C. 112 has been withdrawn.
Regarding the rejections under 35 U.S.C. 103, Applicant's arguments filed February 10, 2026 have been fully considered but they are not persuasive.
According to Applicant, the teachings of Hunold relied upon for the claimed number of carbon-containing particles are in fact a distinct parameter from what is claimed. Applicant notes that the Office asserts Hunold discloses minimizing the amount of carbon as an obvious optimization, but the claimed invention demonstrates that merely reducing the total carbon weight does not solve the problem caused by specific conductive particles. Further, Applicant argues that Hunold uses organic binders, which are a source of carbon and which constitute a teaching away. Given Takai fails to cure the deficiencies of Hunold, Applicant request the withdrawal of the obviousness rejection. Examiner respectfully disagrees.
While Applicant is correct that the disclosed parameter and the claimed parameter are distinct, Examiner notes that both serve the purpose of minimizing the amount of carbon. Specifically, Hunold discloses that it is critical that the use of a temporary decomposes leaving virtually no residue or are present in such low concentrations that the decomposition residue is in the form of free carbon does not exceed about 0.1% by weight, see col. 3 lines 43-65. Decomposing with virtually no residue or containing a residue that does not have more than 0.1% by weight of free carbon is considered to render obvious amounts of carbon that have 10 particles or less per 10g of boron nitride. Specifically, Examiner notes that the amount of impurity carbon in Applicant’s specification is from 5 to 170 ppm [0029]. Given the reference renders obvious an amount of carbon that is less than 170 ppm and including zero, Examiner maintains the position that the reference renders obvious the claimed carbon particle concentration. Further note, the inclusion of an organic binder is not considered a teaching away given the reference disclose virtually no residue after decomposition or an amount of free carbon in the residue that does not exceed 0.1% by weight.
For the above reasons, the rejections under 35 U.S.C. 103 are respectfully maintained.
Conclusion
THIS ACTION IS MADE FINAL. 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 LAURA A AUER whose telephone number is (571)270-5669. The examiner can normally be reached Monday - Friday 9 am - 4 pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, M. Veronica Ewald can be reached at (571)272-8519. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/LAURA A AUER/Primary Examiner, Art Unit 1783
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