Patent ID: 8957134
Filing Date: 2015-02-17
Classification: C01P,C08F,C08G,C08L,C09B,C09C,C09D

Abstract:
1. A method of making an encapsulated pigment dispersion comprising steps of a) dispersing a pigment using a polymeric dispersant in an aqueous vehicle wherein the polymeric dispersant not bound to the pigment is less than 0.12 grams per gram of pigment in the pigment dispersion, and the polymer dispersant bound to the pigment is less than 0.33 grams per gram of pigment, where the polymeric dispersant not bound to the pigment is measured by a centrifugation method; b) adding at least one encapsulation monomer to the aqueous vehicle of step (a) to form a first dispersed pigment/encapsulation monomer/aqueous mixture and wherein the encapsulation monomer comprises acrylate monomers; c) dispersing the encapsulation monomer/aqueous mixture using high shear mixing to form a second dispersed pigment/encapsulation monomer/aqueous mixture; d) polymerizing the encapsulation monomer by adding a polymerization initiator to the second dispersed pigment/encapsulation monomer/aqueous mixture; wherein for the final encapsulated pigment dispersion the weight ratio of final free polymer to bound polymer is less than 0.9 and the final free polymer is measured by a density gradient centrifugation method.