Powder Coating and
Method for Its Use On Heat-Resistant Substrates U.S. Patent 5,919,568
Issued: July 6, 1999
Inventor: E. Wolf
Assigned to Huels Aktiengesellschaft This is a patent for a powder coating and a substrate coated with the same,
in which the coating contains a mixture of a pulverulent polyisocyanate
component that is a solid at temperatures of less than 50ºC and a liquid at
temperatures above 160ºC (of the formula I##STR1## where R, R(C)
and n are as described herein) and a pulverulent, organic polyhydroxy
component that is a solid at temperatures of less than 507C and a liquid at
temperatures above 160ºC and having a ratio of secondary to primary OH groups
of at least 3:1. The two components are present in a ratio of equivalents of
NCO:OH groups from 0.5:1 to 1.3:1. The second component is selected from the
group consisting of bisphenol A-containing epoxy resin, oligoamides containing
secondary hydroxyl groups and mixtures thereof.