PURPOSE: To prepare the titled polymer particle with excellent resistance to heat, thermal deformation and solvent, by the polymn. of a vinyl monomer with a spcified org. silane cpd. in an aqueous medium followed by impregnation with a foaming agent.
CONSTITUTION: A vinyl monomer wuch as α-methylstyrene is subjected to polymn. with 0.1W15wt% org. silane cpd. of formula XSiYnZm (wherein n is 1W3; m is 1W 2; n+m=3; X is an org. group having a copolymerizable double bond; Y is a hydrolyzable group; Z is a monovalent inert org. group) in the presence of a polymn. initiator in an aqueous medium, and the polymn. is completed with addition of 1W 20wt%, based on the foamable vinyl polymer particle to be prepared, foaming agent such as propane when 50wt% or more monomer has been converted.
MUKAIYAMA YOSHIYUKI
SUGITANI HATSUO
KAWAI HIROMASA
