Aliphatic polyurethane coating composition
AssigneeE. I. Du Pont de Nemours and Company
InventorJoseph A. Vasta
Life of this patent
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Abstract
A coating composition of an aliphatic polyurethane resin in an organic solvent; wherein the resin has terminal hydroxyl groups, a weight average molecular weight of about 3,000 to 30,000, and is the reaction product of a fatty acid ester of drying oil fatty acids, polyol, having at least three reactive hydroxyl groups, aromatic monobasic and an alkyl amino aromatic acid that provides ultraviolet light absorbing groups, and an aliphatic diisocyanate; the composition can contain conventional pigments, organo metallic driers, and light stabilizers and cures at ambient temperatures and is useful as primary finish for metals, plastics and reinforced plastics, and can be used as a refinish composition for automobiles and trucks.
Claims21
A coating composition comprising 30-90% by weight, based on the weight of the composition, of an organic solvent and 10-70% by weight, based on the weight of the composition, of a binder;
- wherein the binder comprises
- an aliphatic polyurethane resin having terminal hydroxyl groups and a weight average molecular weight of about 3,000 to 30,000 determined by gel permeation chromatography and consists of a condensation polymerization product of
- (1) a fatty acid ester consisting of the esterification product of drying oil fatty acids a polyol having at least three reactive hydroxyl groups an, aromatic monobasic acid, and an alkyl amino aromatic acid that provides ultraviolet light absorbing groups with
- (2) an aliphatic diisocyanate.
A process for making an aliphatic polyurethane which comprises the following steps:
- (1) contacting drying oil fatty acids, polyol having at least three reactive hydroxyl groups, aromatic monobasic acid and an alkyl amino aromatic acid at a temperature of 160.degree.-250.degree. C. for about 2-8 hours to form a fatty acid ester and
- (2) contacting said fatty acid ester with aliphatic diisocyanate in the presence of a metallic organo catalyst for about 0.5 to 3 hours at a temperature of about 30.degree.-100.degree. C. to form said resin having terminal hydroxyl groups and a weight average molecular weight of about 3,000 to 30,000 determined by gel permeation chromatography.
Dependencies are inferred from the claim text.