AQUEOUS EMULSION COATINGS COMPOSITION COMPRISING SELF- EMULSIFIABLE EPOXY ESTER COPOLYMER MIXTURE

摘要

A non-gelled hydroxy ester copolymer compsn. free of oxirane functionality comprises an acidic copolymer - epoxy resin hydroxy ester reaction prod. The epoxy resin is a mixt. contg. >=5 wt. % of aromatic polyether which is difunctional in oxirane functionality which is consumed by reaction with the acidic copolymer. The acidic copolymer is a soln. copolymer of monoethylenically unsatd. monomers comprising >=20% of monoethylenically unsatd. carboxylic acid. The epoxy resin mixt. constitutes >=40% of the total resin solids content, and provides oxirane functionality in a stoichiometric deficiency w.r.t. carboxyl functionality in the acidic copolymer of 1:2 - 20. At least a portion of the carboxyl functionality in the hydroxy ester reaction prod. is reacted with a base to render the prod. self-emulsifiable in water. When the copolymer salt is diluted with water it forms an aq. emulsion coating compsn. having high stability. The coating compsn. is esp. useful for the interior coating of metal containers which will come in contact with food or beverages.