Patent ID: 6719931
Filing Date: 2004-04-13
Classification: B01F,B01J,B41M,C08G,C08L,C09D,D21H

Abstract:
A process for preparing a dispersion of microcapsules, comprising: combining in water at a pH of from 3 to 6.5 an essentially water-insoluble core material to be encapsulated, a partially methylated melamine-formaldehyde resin having a molar ratio of melamine: formaldehyde:methanol of from 1:3.0:2.0 to 1:6.0:4.0, and an alkali metal salt of a homopolymer or copolymer of 2-acrylamido-2-methylpropane-sulfonic acid,preforming the microcapsules at a temperature of from 20 to 50Â° C., and then curing the capsule wall of the preformed microcapsules at >50 to 100Â° C., and adding, during the curing, from 5 to 100% by weight of melamine, based on the weight of the melamine-formaldehyde resin.