Hot-melt adhesive based on non hydrogenated, linear ABC block polymers

摘要

The hot-melt adhesive is composed of a non-hydrogenated, linear block copolymer A-B-C, a customary tackifying resin and a customary rubber extender oil. The linear block copolymer has a terminal nonelastomeric polymer block which accounts for from 5 to 25% by weight, based on A-B-C, and is composed of aromatic monovinyl monomers; it further contains an elastomeric (co)polymer B as centrepiece in a proportion of from 50 to 85% by weight, based on A-B-C; this is composed either of isoprene alone, which is preferred, or of a mixture of isoprene and butadiene, in which case butadiene contents of from 5 to 70% by weight are employed. The polymer C accounts for from 5 to 40% by weight, based on A-B-C, and consists either of a homopolymer of isoprene, in which case more than 50% by weight of 3,4-linked units should be present, or of a copolymer of styrene and butadiene or of styrene and isoprene in certain ratios, in which case the monomers must be present in random distribution.