seen framstella a powdered herdbar beleggningskomposition from a karboxylgrupphaltig polyester and a epoxiforening

摘要

Process for the preparation of powdered thermosetting coating composition suitable for application as paint or varnish on electricity-conducting articles by powder spray methods and fluidized bed coating processes, which comprises: in a first stage, preparing a branched-chain hydroxyl group-containing polyester from at least one dicarboxylic organic acid, at least one polycarboxylic aromatic acid and at least one dihydric organic compound; in a second stage, esterifying the hydroxyl group-containing polyester thus obtained with an aromatic or hydroaromatic dicarboxylic acid to give a carboxyl group-containing polyester having an acid number which is substantially equal to the hydroxyl number of the hydroxyl group-containing polyester obtained in the first stage; and in a third stage, homogenously mixing the carboxyl group-containing polyester obtained in the second stage with an epoxy compound containing at least two epoxy groups, and optionally adding auxiliary substances conventionally used in the manufacture of powdered paints and varnishes; and powdered thermosetting compositions suitable as paint or varnish obtained by this process.