High solids polyesters capable of dissolving in an organic solvent

Abstract

A composition of matter comprising a polyester capable of dissolving in an organic solvent, having a solids content of at least 75% by weight, at a viscosity of X-Z on the Garner scale, prepared by reacting an aromatic polycarboxylic acid, anhydride, or a functionally acid esterifiable derivative thereof, an aliphatic polycarboxylic acid, anhydride or a functionally acid esterifiable derivative thereof, an aliphatic polyol and a monofunctional fatty acid to an acid number less than about 10, and then reacting the product of that reaction with an aromatic or aliphatic polycarboxylic acid, anhydride or a functional acid esterifiable derivative thereof to an acid number greater than 10 and less than about 60, wherein the total reactants have a hydroxyl/carboxyl ratio of greater than 1; the amount of monofunctional fatty acid employed ranges from about 20 to about 50% of the total number of acid equivalents of the reactants and the amount of aromatic polycarboxylic acid reacted in the first step ranges from about 20% to about 50% of the total number of acid equivalents of the reactants. Also described is a coating composition employing the above described polyester in conjunction with a nitrogenous composition, preferably for coating metallic substrates.

Dependencies are inferred from the claim text.