PROCESS FOR PREPARING POLYMER ENCAPSULATED TIO2 PARTICLES

摘要

The present invention relates to a process for preparing an aqueous dispersion of polymer encapsulated TiO 2 particles, comprising a multistage polymerization steps that includes a relatively large amount of low T g first monomers and a relatively small amount of high T g second monomers that comprise a relatively high concentration of an acid monomer. The dispersion of encapsulated TiO 2 particles shows significantly improved freeze-thaw stability as compared with prior art processes that do not include staging with the second monomers described herein.