Patent ID: 7781552
Filing Date: 2010-08-24
Classification: C08F

Abstract:
1. A styrenic copolymer produced by a living polymerization method comprising an isopropenyl aromatic unit represented by the formula (1): wherein the substituent group R a vinyl aromatic unit represented by the formula (2): wherein the substituent group R wherein the content (A) of said isopropenyl aromatic unit in said styrenic copolymer is in a range of 5 to 95% by weight, a ratio (Mw/Mn) of a weight-average molecular weight (Mw) of said styrenic copolymer to a number-average molecular weight (Mn) thereof is in the range of 1.6 to 4.0, and the weight-average molecular weight_(Mw) of said styrenic copolymer is 70,000 or more, and wherein the relationship between the content (% by weight) (A) of said isopropenyl aromatic unit in said styrenic copolymer and the glass-transition temperature (° C.) (Tg) of said styrenic copolymer satisfies the formulae (a):