Powder lacquer and its use for coating heat-resistant substrates

Abstract

The present invention relates to a powder lacquer containing a mixture of (A) a polyisocyanate component in power form which is solid below about 40.degree. C. and liquid above about 150.degree. C. and (B) a organic polyhydroxyl component in powder form which is solid below about 40.degree. C. and liquid above about 150.degree. C., components (A) and (B) being present in quantities corresponding to an equivalent ratio of isocyanate groups to hydroxyl groups of about 0.6:1 to 1.2:1, characterized in that component (A) is based on a polyisocyanate or polyisocyanate mixture which (a) does not contain any blocking agents for isocyanate groups, (b) has a content of free isocyanate groups (expressed as NCO) attached to tertiary, aliphatic or cycloaliphatic carbon atoms of about 8 to 24% by weight and an average NCO functionality of at least 2.1, (c) has a urethane group content (expressed as --NH--CO--O--) of about 3 to 30% by weight and (d) has an isocyanurate group content (expressed as C.sub.3 N.sub.3 O.sub.3) of 0 to about 30% by weight. The present invention also relates to the use of this powder lacquer for the production of coatings on heat-resistant substrates by methods known in powder lacquer technology.

Dependencies are inferred from the claim text.