Water dilutable epoxy coating compositions
AssigneeThe International Paint Company Limited
InventorsBasil W. Brook, Frank Reeder
Life of this patent
Estimating the term…
Abstract
A coating composition comprises a water dilutable dispersion of (a) the reaction product of an epoxy resin with a primary or secondary amine and (b) a polymer containing free carboxyl groups. The epoxy resin and amine are preferably reacted in an organic solvent and a solution of the reaction product is mixed with a solution of the carboxyl-containing polymer (b) in an amount sufficient to provide an excess of free carboxyl groups over the amine groups in the epoxy resin reaction product (a). The coating composition is preferably applied to a substrate in the form of an aqueous dispersion in which (a) and (b) are held in stable dispersion by a base such as ammonia or an amine.
Claims15
A coating composition comprising a water-dilutable dispersion of (a) the reaction product of an epoxy resin having an epoxy molar mass of about 1,000 to about 8,000 with a non-tertiary amine in an amount sufficient to provide from about 40 to 100 percent equivalents of amine based on epoxide groups in said epoxy resin, and (b) a polymer containing free carboxyl groups present in an amount sufficient to provide free carboxyl groups in a ratio of about 1.5:1 to about 20:1 based on sum of the amine groups and unreacted epoxy groups in the epoxy resin reaction product (a), said epoxy resin reaction product (a) providing at least about 40 percent, by weight, of the resin solids in the coating composition.
A process for producing a water-dilutable coating composition comprising reacting an epoxy resin having an epoxy molar mass of about 1,000 to about 8,000 with a non-tertiary amine in an amount sufficient to provide from about 40 to 100 percent equivalents of amine based on epoxide groups in said epoxy resin, and mixing a solution of the resulting product (a) in an organic solvent with a solution of a polymer (b) containing free carboxyl groups and present in an amount sufficient to provide a ratio of free carboxyl groups to the sum of the amine groups and unreacted epoxy groups in the epoxy resin reaction product (a) of about 1.5:1 to about 20:1, the epoxy reaction product (a) providing at least 40 percent, by weight, of the resin solids in the coating composition.
Dependencies are inferred from the claim text.