Patent ID: 8021716
Filing Date: 2011-09-20
Classification: C09B,C09D,Y10T

Abstract:
1. A process for encapsulating pigment particles comprising the steps of: (A) producing a dispersion of the pigment to be encapsulated, (B) applying a polyelectrolyte layer to the surface of the pigment particles, (C) applying at least one polyelectrolyte layer having opposite charge to the pigment particles formed in step (B), or adding low molecular weight, multivalent ions oppositely charged to the pigment particles formed in step (B), or both and (D) optionally repeating steps (B) and (C), said steps (B), (C) and optionally step (D) being carried out in the presence of a nonionic surfactant and wherein the encapsulated pigment particles contain (a.) 20% to 99% by weight of the pigment, (b.) 1% to 80% by weight of the polyelectrolyte layers of steps (B) and (C), and (c.) 0% to 30% by weight of the multivalent, low molecular weight ions.