VINYL AROMATIC BLOCK COPOLYMERS AND COMPOSITIONS CONTAINING THEM

摘要

Block copolymers suitable for hot melt adhesive composition characterized in that they have the general formula (AB)p(B1)qX, wherein A is poly(vinylaromatic) block and B and B1 are the same or different poly(butadiene) blocks, wherein the 1,2 addition (vinyl) content is in the range of from 25 to 70% by weight, wherein X is the residue of a multivalent coupling agent having a maximum of active sites (m) in the range of from 3 to 6, wherein p and q both are integers of from 0 to m, provided that the sum of p and q values is less than m and the coupling efficiency is less than 90%, said block copolymer having an average total vinyl aromatic content in the range of from 10 to 50 wt % and preferably in the range of from 10 to 30 wt %, and having a total apparent molecular weight in the range of from 100,000 to 500,000. Adhesive, sealant, or coating compositions comprising said block copolymers and in particular radiation curable compositions, the use of said compositions, and processes for the preparation of said block copolymers are also included herein.