公开(公告)号：US20200277189A1

公开(公告)日：2020-09-03

申请号：US16647756

申请日：2019-06-12

Applicant: SHOWA DENKO K.K.

Inventor： Boanerges THENDIE ,  Masaru FUKASAWA

IPC: C01B21/064

Abstract: A hexagonal BN powder including aggregates of primary particles of hexagonal BN containing boron and oxygen as impurity elements at a content of 1.00 to 30.00% and 0 to 1.00% by mass, respectively, which has a peak A in a predetermined particle diameter range and a 50% volume cumulative particle diameter D50 (d1) of 30.0 to 200.0 μl in a particle size distribution curve, and in which a ratio of a height (a1) of the peak A before treatment to a height (a2) of the peak A after treatment is 0.80 to 1.00 and a ratio of D50 (d1) before treatment to D50 (d2) after treatment is 0.80 to 1.00 when the hexagonal BN powder is ultrasonically treated under a predetermined condition for 1 minute. Also disclosed is a method for producing the hexagonal BN powder, a composition and a heat dissipation material.