Coating compositions incorporating composite polymer particles
AssigneeRohm and Haas Company
InventorsAlvin C. Lavoie, Jen-Chi Chen, Chao-Jen Chung, Dennis P. Lorah, Peter R. Sperry, Andrew W. Gross
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Abstract
This invention relates to a non-aqueous coating composition and a method for reducing the drying time of a non-aqueous coating composition by incorporating composite polymer particles having a softer, insoluble first stage and a hard second stage without adversely affecting the viscosity and pot life of the liquid coating composition and without degrading the properties of the final dry coating, including color, flexibility, impact resistance, gasoline resistance, salt spray resistance and humidity resistance.
Claims20
A non-aqueous coating composition, comprising:
- (a) a film-forming resin;
- (b) a volatile organic liquid which is a solvent for the film-forming resin;
- and
- (c) at least one composite polymer particle,
- wherein the weight ratio of said composite polymer particles to said film-forming resin solids is from about 10:90 to about 40:60;
- wherein said composite polymer particles are from about 50% by weight to about 90% by weight a first stage polymer and from about 10% by weight to about 50% by weight a second stage polymer, based on the total weight of said composite polymer particle;
- wherein said first stage polymer is formed from at least one ethylenically unsaturated monomer, is insoluble in said film-forming resin and said volatile organic liquid and has a glass transition temperature of less than the glass transition temperature of said second stage polymer;
- and
- wherein said second stage polymer is formed from at least one ethylenically unsaturated monomer and has a glass transition temperature of greater than about 40.degree. C.
The non-aqueous coating composition according to claim wherein said film-forming resin is selected from the group consisting of an alkyd resin, a polyester resin, a polyurethane resin, an epoxy resin, a melamine resin, a urea resin, an isocyanate resin and an acrylic solution resin.
A method of improving the drying time of a non-aqueous coating composition containing a film-forming resin and a volatile organic liquid which is a solvent for the the film-forming resin, where the improvement comprises:
- incorporating composite polymer particles into the coating composition,
- wherein the weight ratio of said composite polymer particles to said film-forming resin solids is from about 10:90 to about 40:60;
- wherein said composite polymer particles is from about 50% by weight to about 90% by weight a first stage polymer and from about 10% by weight to about 50% by weight a second stage polymer, based on the total weight of said composite polymer particle;
- wherein said first stage polymer is formed from at least one ethylenically unsaturated monomer, is insoluble in said film-forming resin and said volatile organic liquid and has a glass transition temperature less than the glass transition temperature of said second stage polymer;
- and
- wherein said second stage polymer is formed from at least one ethylenically unsaturated monomer and has a glass transition temperature of greater than about 40.degree. C.
Dependencies are inferred from the claim text.