Method of preparing encapsulated pigment dispersions which include polyurethane dispersions

A method of making an encapsulated pigment comprising the steps of:

• a) dispersing a pigment using a first polymeric dispersant in an aqueous vehicle, wherein the first polymeric dispersant comprises acrylic and acrylate monomers and wherein the first polymeric dispersant has a number average molecular weight of 2000 to 9500 daltons;
• b) preparing an aqueous emulsion comprising at least one encapsulation monomer, and least one aqueous polyurethane dispersion and a surfactant or a second polymeric dispersant, wherein the second polymeric dispersant comprises acrylic and acrylate monomers and wherein the encapsulation monomer comprises acrylate monomers;
• c) adding the aqueous emulsion of step (b) to the aqueous vehicle of step (a) to form a first dispersed pigment/encapsulation monomer/aqueous polyurethane dispersion/aqueous mixture;
• d) dispersing the encapsulation monomer/aqueous polyurethane dispersion/aqueous mixture using high shear mixing to form a second dispersed pigment/encapsulation monomer/aqueous mixture;
• and
• e) polymerizing the encapsulation monomer by adding a polymerization initiator to the second dispersed pigment/encapsulation monomer/aqueous mixture.