| 摘要 |
<p>Hard or Fixed Based Permeable Hollow Particle Dispersions Process for making core-sheath polymer particles containing voids, said particles useful for opacifying comprising (A) emulsion polymerizing a core from a core monomersystem comprised of at least one ethylenically unsaturated monomer containing acid functionality; (B) encapsulating said core with a hard sheath by emulsion polymerizing a sheath monomer system, in the presence of said core, said sheath permitting penetration of fixed or permanent bases; (C) swelling at elevated temperature the resultant core-sheath polymer particles with fixed or permanent base so as to produce a dispersion of particles which, when dried, contain a microvoid which causes opacity in compositions in which they are contained, provided that either (1) said sheath comprises at least about 1% said functional monomer or (2) said swelling takes place in the presence of solvent. Compositions comprising said core-sheath polymer particles are also disclosed.</p> |
