Opacifying particles with internal void and methods for making the same

Abstract

The invention includes a method of preparing an aqueous dispersion of particles at least partially encapsulated by a polymer, the method comprising dispersing inorganic particles in an aqueous phase; functionalizing at least a portion of the surfaces of the inorganic particles with a coupling agent, the coupling agent having pendent reactive groups; polymerizing the reactive groups on the functionalized particles with a first polymerizable component to produce inner polymer shells surrounding the inorganic particles; polymerizing a second polymerizable component to form outer polymer shells at least partially encapsulating the inner polymer shells; and producing voids within the outer polymer shells, such that the inorganic particles are received within the voids.

Dependencies are inferred from the claim text.