Abstract: Radiation sensitive block copolymers to be used in hot melt adhesive composition characterized in that they have the general formula (AB).sub.p (B.sup.1).sub.q X, wherein A is poly(vinylaromatic) block and B and B.sup.1 are poly(butadiene) blocks, wherein X is the residue of a hexavalent coupling agent, wherein p and q both have a number average value in the range from 1.5 to 4.5, whereas the sum of p and q values being 6, wherein the block copolymers have an average bound vinyl aromatic content in the range of from 10 to 50 wt %, preferably in the range of from 10 to 30 wt %, a total apparent molecular weight in the range of from 100,000 to 500,000, and a vinyl content in the poly(butadiene) blocks in the range of from 35 to 70 wt %.

Abstract: Block copolymers suitable for hot melt adhesive composition characterized in that they have the general formula (AB).sub.p (B.sup.1).sub.q X, wherein A is poly(vinylaromatic) block and B and B.sup.1 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.