RADIAL STYRENE-ISOPRENE-BUTADIENE MULTI-ARMED BLOCK COPOLYMERS AND COMPOSITIONS AND ARTICLES CONTAINING BLOCK COPOLYMERS

摘要

The invention is drawn to radial block copolymers of the formula: (pS-pI- pBnX), wherein pS is polystyrene, pI is polyisoprene, pB is polybutadiene, X is the residue of a multifunctional coupling agent used in the production of the radial block copolymer, and n is a number greater than or equal to 3 representative of the number of branches appended to X; pressure sensitive adhesive compositions comprising such radial block copolymers and articles o f manufacture produced therefrom. The pS component of the radial block copolymers of this invention comprise from about 14 to about 24 parts per 10 0 parts by weight of the radial block copolymer; the molecular weight (as polystyrene equivalent) of the radial block copolymer is between about 200,0 00 to about 400,000; and the weight amount of polybutadiene in the pI-pB segmen t is less than 50 weight percent.