Aqueous based coating compositions having improved metallic pigment orientation

Abstract

An aqueous based coating composition contains a polymeric film-forming resin and as an additive from about 1 to about 40 percent by weight based on the resin solids of the composition of an oligomeric ester having an acid value of from about 100 to about 500 of the structure: ##STR1## where X is the residue of a polyol containing from 1 to 50 carbon atoms per hydroxyl group after reaction with an acid or an anhydride, R is an organic moiety from the acid or anhydride and A has an average value of about 2 or greater. The coating compositions are particularly advantageous as metallic pigmented coating compositions for automotive basecoat applications because they exhibit excellent resistance to mottling, have good flop and have reduced sensitivity to fluctuations in relative humidity.

Dependencies are inferred from the claim text.