Patent ID: 8859644
Filing Date: 2014-10-14
Classification: C01P,C08F,C09B,C09C,C09D

Abstract:
1. A method of making an aqueous encapsulated pigment dispersion, comprising the steps: a) dispersing a pigment with a polymeric dispersant in an aqueous vehicle; b) adding an encapsulation monomer mixture to the aqueous vehicle of step (a) at a first temperature; wherein the encapsulation monomer mixture comprises 50 to 100 weight percent of a first monomer, 0 to 50 weight percent of a second monomer, and 0 to 25 weight percent of a third monomer, wherein the first monomer is soluble in an aqueous solution below the first monomer's Lower Critical Solution Temperature and sparingly soluble above Lower Critical Solution Temperature, wherein the second monomer is a hydrophobic acrylate monomer and the third monomer is a hydrophilic acrylic monomer; c) dispersing the encapsulation monomer/aqueous mixture using high shear mixing to form a second dispersed pigment/encapsulation monomer/aqueous mixture; d) heating the mixture from step c) to a second temperature at least 20° C. above the first temperature; and e) polymerizing the encapsulation monomer by adding a polymerization initiator to the second dispersed pigment/encapsulation monomer/aqueous mixture.