To obtain a styrene polymer which gives an extrudate excellent in external appearance, is excellent in the balance among impact strength, tensile strength, elongation, and flowability, and allows few fish eyes to occur by subjecting a monomer mixture comprising a styrenic monomer and a (meth) acrylic ester monomer to bulk-suspension two-stage polymn. in the presence of a rubbery elastomer under specified conditions.
This styrene polymer is produced by subjecting 85-99 pts.wt. monomer mixture comprising a styrenic monomer and a (meth)acrylic ester monomer to bulk-suspension two-stage polymn. in the presence of 1-15 pts.wt. rubbery elastomer, the sum of the monomer mixture and the elastomer being 100 pts.wt. In the above polymn., the bulk polymn. is conducted until the sum of the elastomer and a polymer formed from a part of the monomer mixture reaches higher than 42wt.% but not higher than 80wt.% followed by suspension polymn. The content of the (meth)acrylic ester monomer in the monomer mixture is pref. 20-70wt.% in terms of product clarity.
SAKAMOTO HIDEAKI
WATABE HIDEKI
