THERMOSETTING COATING COMPOSITONS AND PROCESS FOR THE COATING OF SUBSTRATES

摘要

The present invention relates to thermosetting two-component coating compositions containing (A) a prepolymer having an average molecular weight of from 1,000 to 15,000 having an average of from 2 to 4 ketoxime-blocked aromatic isocyanate groups: (B) a crosslinking agent corresponding to the following general formula: wherein R1, R2, R3 and R4 independently represent hydrogen or C1- to C3-alkyl groups with the proviso that if R1 to R4 all are hydrogen, 75 % of the diamine have the cis,ris-structure and optionally (C) pigments, fillers blowing agents or other known additives. The equivalent ratio of blocked isocyanate groups to NH2 groups is from about 1.35:1 to about 0.95:1, and the coating composition contains not more than about 15% by weight of organic solvents and is free from aqueous polymer dispersions or solutions. The coating compositions may be applied to substrates by the direct or reverse process and may be applied as a top coat, adhesive coat or foam coat.