The symmetrical linear block copolymer and those manufacturing method null formula which include the block of polarity vinyl monomer origin and hydrogen are added

摘要

PROBLEM TO BE SOLVED: To obtain a symmetrical linear block copolymer which satisfies modern requirements of final precision use and shows markedly improved physical properties. ;SOLUTION: There is provided a symmetrical linear block copolymer of the formula: C-A-C or C-B-C [wherein block B represents a poly (predominantly conjugated diene) block, which has optionally been selectively hydrogenated until a degree of residual unsaturation (RU) of ≤20%, preferably, ≤5%, and the vinyl content in the precursor copolymer is in the range of 20 to 45 mol.% relative to the originally present conjugated diene, block A represents a poly (predominantly monovinylaromatic) block; block C represents a poly (predominantly polar vinyl compound) block, representing a bound weight fraction, relative to the weight of the total block copolymers of ≤30 wt.%, and the molecular weight distribution of the total linear block copolymers is ≤1.20].;COPYRIGHT: (C)1996,JPO