CROSSLINKED POLYMER MICROPARTICLES DERIVED FROM BETAINE MONOMERS HAVING THREE-DIMENSIONAL NETWORK

摘要

Polymer microparticles having a three-dimensional network structure and an average particle size of 0.01 to 1 micron are obtained by emulsion polymerization of ethylenically unsaturated monomeric composition containing (a) at least one polyfunctional monomer having a plurality of polymerizable sites, or (b) a combination of two ethylenically unsaturated monomers each bearing mutually reactive functional groups in an aqueous medium in the presence of a compound or resin having a betaine group. The betqine compound or resin is incorporated into the polymer microparticles by physically adhering or covalently binding thereto to enhance the dispensing stability of the microparticles over a wide range of pH.