US 5,401,697 A · Process for converting water-sensitive ceramic powders into a free-flowing granulated powder

Abstract

A method of processing water-sensitive ceramic powders, particularly carbothermically produced aluminum nitride, whereby the ceramic powder is deagglomerated in a dry milling step with addition of an alkylamine which is liquid at room temperature is disclosed. The alkylamine is added in an amount sufficient to produce a monomolecular layer on the surface of the ceramic powder. The deagglomerated powder subsequently is vigorously stirred with a concentrated aqueous solution or dispersion of binder and rapidly and gently dried, preferably by freeze drying. Aluminum nitride powder prepared by this process can be further processed into shaped parts with a high thermal conductivity.

Claims19

Dependent claims

A process for converting water-sensitive ceramic powder into a free-flowing granulated powder comprising;

(a) deagglomerating the ceramic powder in a dry milling step, whereby at least one alkylamine which is liquid at room temperature is added in an amount sufficient to produce a monomolecular layer on the surface of the ceramic powder, and wherein said alkylamine comprises primary or secondary alkylamines having from 2 to 8 carbon atoms per alkyl group;
(b) vigorously stirring the deagglomerated powder with a concentrated aqueous solution or dispersion of a binder;
and
(c) subsequently drying rapidly at temperatures below 50.degree. C.

1 more element

Dependencies are inferred from the claim text.

Process for converting water-sensitive ceramic powders into a free-flowing granulated powder

Life of this patent

Process for converting water-sensitive ceramic powders into a free-flowing granulated powder

Life of this patent

Abstract

Claims19