VERFAHREN ZUR HERSTELLUNG VON BORNITRID.

摘要

Mixt. for reaction at 700-1200 deg.C in non-oxidising atmos. to form BN comprises (wt.%): (1) 45-50 melamine and 50-55 (3-4 B2O3:1 H3BO3); (2) 35-40 dicyandiamide and 60-65 (1-2 B2O3:1 H3BO3); (3) 30-40 melamine and 60-70 (1 B2O3:1-2 ammonium pentaborate tetrahydrate (APT)); (4) 40-50 dicyandiamide and 50-60 (2-3 B2O3:1 APT); (5) N-contg. nitride promoter and 4-1:1-3 mixt. of B2O3/H3BO3 which can be formed by reaction of B2O3 and blowing agent in stated ratio; (6) 45-70 (4-1 B2O3:1-3 blowing agent) and 30-55 N-contg. nitride promoter. Blowing agents are water, meta-/pyro-/ortho-boric acid or APT or mixts. thereof. Prod. is amorphous BN.