Poly (styrene - butadiene - styrene) block copolymers having a high vinyl - content in the butadiene block and a system based on hot melt adhesives

摘要

The present invention concerns a poly(styrene-butadiene-styrene) polymer having a high vinyl content in the butadiene block comprising in combination a polystyrene content (PSC) within a range of 15-20 % by weight, a coupling efficiency (CE) of 50-80 %, a step I molecular weight (MW) between 9,000 and 10,000 kg/mol, and a vinyl content between 20-45 %. Hot melt adhesive compositions are also described comprising said SBS polymer together with a tackifying resin, a plasticizer and an anti-oxidant.