Binder for coating composition
AssigneeCray Valley S.A.
InventorsWerner Lohs, Robert Thomas Lucas, Simon Edward Vivian
Life of this patent
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Abstract
A binder for a coating composition is obtainable as the reaction product of a carboxyl-terminated fatty acid ester with an ethylenically unsaturated carboxylic acid and an ethylenically unsaturated carboxylic acid ester. The carboxylic fatty acid ester is produced by reaction of an autoxidisable fatty acid and a polyol, with modification to introduce at least one terminal carboxyl group. The reaction is optionally effected in an organic solvent which is substantially removed at the end. The material is neutralized with a base to render it water-soluble. Thixotropy can be endowed by an amine/(poly)isocyanate final reaction stage to prior neutralization.
Claims23
A binder for a water-based coating composition, the binder comprising the product of a reaction mixture consisting essentially of:
- (a) a carboxy-terminated fatty acid ester, obtained by reaction in two successive stages:
- a first stage where a fatty acid ester is formed by reacting autoxidisable fatty acids with polyhydric polyols at 200° C. to 250° C. to an acid number of less than 10 mg of KOH/g and with the resultant fatty acid ester having an hydroxyl number of between 10 and 100 mg KOH/g
- a second stage with reaction of the fatty acid ester of the first stage with a carboxylic acid anhydride at a temperature lower than that of the first stage to obtain the carboxy-terminated fatty acid ester, with an acid value of between 10 and 100 mg KOH/g;
- (b) an ethylenically unsaturated carboxylic acid;
- (c) an ester of an ethylenically unsaturated carboxylic acid,
- (d) optionally, an ethylenically unsaturated monomer, other than an ethylenically unsaturated carboxylic acid, and
- (e) optionally, a hydroxyl functional monomer material.
A process for producing a binder for a water-based coating composition, the process comprising the steps of:
- (a) reacting an autoxidisable fatty acid and a polyol;
- (b) reacting the product of (a) with a carboxyl containing organic compound to attach a carboxyl group;
- (c) introducing an ethylenically unsaturated carboxylic acid and an ester of an ethylenically unsaturated carboxylic acid to the reaction product of (b);
- and
- (d) reacting the combination of (c) to obtain the binder.
Dependencies are inferred from the claim text.