METHOD FOR THE PREPARATION OF BORON NITRIDE POWDER

摘要

This invention is directed to a process for the preparation of boron nitride powder, particularly a fine powder with a low degree of contamination, which demonstrates good caking, heat conductivity and dielectric properties. Specifically, a process for the preparation of amorphous boron nitride (a-BN) is provided wherein the process comprises: mixing powders of boric acid and a carbamide at a temperature in the range of about 250-300°C, thereby forming: ammonium polyborates; boron imide or a mixture thereof and ammonia; and heating of the materials formed in step (a) to a temperature in the range of about 500-600°C, thereby forming a powder of a-BN.