Aqueous coating comprising dispersible epoxy resin-acid polymer ester and diluent polymer, and method of preparation

A method for preparing an aqueous dispersion comprising

• preparing a mixture of an addition polymer containing carboxyl groups which is self dispersible in water in neutralized form and a different addition polymer;
• and reacting said mixture with an epoxy resin containing 1,2-epoxy groups to prepare a product which is substantially free of unreacted 1,2-epoxy groups which contain hydroxy ester groups from the reaction of 1,2-epoxy groups with the carboxyl groups on said addition polymer and which is self-dispersible in water;
• and
• dispersing the product so obtained in water with the addition of ammonia or an organic amine neutralizing agent in an amount sufficient to render the composition stably dispersible in water.

A method for preparing an aqueous dispersion comprising the steps of

• A. preparing a solvent solution of an ionic polymer component containing sufficient carboxyl groups to render it self dispersible in water in neutralized form by reacting an epoxy resin containing 1,2-epoxy groups, and a preformed addition polymer containing carboxyl groups, said ionic polymer containing hydroxy ester groups from the reaction of 1,2-epoxy groups on said epoxy resin with carboxyl groups on said preformed addition polymer, and being substantially free of unreacted 1,2-epoxy groups;
• B. adding to said solvent solution of the ionic polymer component, an addition polymer different from said preformed addition polymer defined in (A);
• and
• C. dispersing the mixture so obtained with the addition of ammonia or an organic amine neutralizing agent in an amount sufficient to render the composition stably dispersible in water.

A method for preparing an aqueous dispersion comprising the steps of

• A. preparing an ionic polymer component containing sufficient carboxyl groups to render it self dispersible in water in neutralized form by reacting an epoxy resin containing 1,2-epoxy groups, and a preformed addition polymer containing carboxyl groups, said ionic polymer containing hydroxy ester groups from the reaction of 1,2-epoxy groups on said epoxy resin with carboxyl groups on said preformed addition polymer, and being substantially free of unreacted 1,2-epoxy groups;
• B. dispersing said ionic polymer component in water with the addition of ammonia or an organic amine neutralizing agent in an amount sufficient to render the composition stably dispersible in water;
• and
• C. incorporating an addition polymer different from said preformed addition polymer defined in (A) into the aqueous dispersion of said ionic polymer component.