Patent ID: 6525115
Filing Date: 2003-02-25
Classification: C08J,C09D,G03C

Abstract:
A method of making an aqueous dispersion of epoxy-functional particles for use in an aqueous coating composition, said method comprising:(a) dissolving into a volatile solvent mixture an epoxy-functional resin and a polymer having an acid number between 30 and 200, wherein the volatile solvent mixture comprises a water-immiscible organic solvent as the major component and a water-miscible organic solvent as a minor component; (b) adding to the organic solvent medium a base to neutralize the acid groups to a degree of neutralization less than 95%; (c) subjecting the resulting organic phase to means for dispersing said organic phase into an aqueous medium; and (d) removing the volatile solvent mixture; wherein the temperature of steps (a) through (b) is maintained such that epoxy functionality in the particles is substantially unreacted, and the average particle size of the epoxy-functional particles in the dispersion is less than about 500 nm.