| 摘要 |
PROBLEM TO BE SOLVED: To obtain a thermoplastic resin compsn. excellent in the balance among impact strength, surface hardness, and clarity by dispersing a specified amt. of rubber-contg. particles having specified particle sizes in a continuous phase of a styrene-(meth)acrylic ester copolymer and by specifying the ratio of wt. average mol. wt. to number average mol. wt. of the compsn. SOLUTION: A suitable rubbery substance is a styrene-butadiene random or block copolymer. The dispersed particles comprise dispersed particles (A) having a number average particle size of 1.0-2.0 μm and contg. the continuous phase taken thereinto and dispersed particle (B) having a number average particle size of 0.1-0.5 μm and contg. no continuous phase taken thereinto, the rubber contents of dispersed particles A and B being 0.2-1.5 wt.% and 4-13 wt.%, respectively. The ratio of Mw/Mn is set at 2.5 or lower. A suitable resin compsn. is obtd. by separately synthesizing a copolymer contg. no dispersed particle, a copolymer contg. particles A, and a copolymer contg. particles B and then mixing these three copolymers. |
