Aqueous coating compositions
AssigneeThe Valspar Corporation
InventorArthur T. Spencer
Life of this patent
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Abstract
A coating composition particularly adapted for can coatings is prepared by the addition polymerization of a monomer such as styrene in a reaction medium comprising a modified 1,2 epoxy resin. The epoxy resin is modified by combining a portion of its 1,2-epoxy groups with epoxy-reactive groups of an ethylenically unsaturated monomer, and reacting others of its 1,2-epoxy groups with a tertiary amine and with a preformed addition polymer containing carboxyl groups to form an ionic, resinous composition containing sufficient carboxyl groups to render the coating composition self-dispersible in water in neutralized form.
Claims12
A method of preparing a coating composition comprising
- a) reacting from about 10% to about 50% of the 1,2- epoxy groups of a 1,2-epoxy resin with an ethylenically unsaturated, epoxy-reactive monomer under conditions providing a modified epoxy resin having unsaturated sites for subsequent copolymerization;
- b) reacting the remaining 1,2-epoxy groups of the modified epoxy resin with a preformed carboxyl functional addition polymer and tertiary amine;
- and
- c) in an aqueous dispersion of the resulting reaction product, copolymerizing the ethylenically unsaturated groups resulting from Step (a) with an ethylenically unsaturated monomer.
A coating composition prepared by a method comprising:
- (a) reacting from about 10% to about 50% of the 1,2-epoxy groups of a 1,2-epoxy resin with an ethylenically unsaturated, epoxy-reactive monomer to provide a modified epoxy resin having unsaturated sites for subsequent copolymerization;
- (b) reacting the remaining 1,2-epoxy groups of the modified epoxy resin with a preformed carboxyl-functional addition polymer and tertiary amine;
- and
- (c) in an aqueous dispersion of the resulting reaction product, copolymerizing the ethylenically unsaturated groups resulting from step (a) with an ethylenically unsaturated monomer.
Dependencies are inferred from the claim text.