Acid-functional polymers derived from cellulose acetate butyrate unsaturated alcohol copolymers and coatings prepared from same

摘要

Novel carboxylic acid-functional polymers are obtained by reacting: (a) a hydroxy-functional polymer having an average of at least two hydroxyl groups per molecule; and (b) a cyclic anhydride under reaction conditions to produce acid groups and ester groups; and wherein the hydroxy-functional polymer is obtained by the copolymerization of: (i) 1-95 weight percent of a cellulose ester; and (ii) 5-99 weight percent of at least one ethylenically unsaturated alcohol copolymerizable with the cellulose acetate butyrate; and (iii) 0-94 weight percent of at least one other ethylenically unsaturated monomer copolymerizable with the cellulose ester and the ethylenically unsaturated alcohol. Curable compositions especially useful as coatings are prepared by mixing the novel carboxylic acid-functional polymers with epoxy-functional compounds and, optionally, with anhydridefunctional compounds and, optionally, hydroxy-functional compounds. The coatings are especially useful in clearcoat/basecoat compositions.