BLOCK POLYMER, THERMOPLASTIC ADDITION POLYMER, PRODUCTION PROCESS, AND USE

摘要

An inexpensive block polymer utilizable in various applications including hot-melt resin composition, pressure-sensitive adhesive and support for pressure-sensitive adhesive. The polymer has a configuration comprising a polyvalent mercaptan unit as the center and a number of polymer segments projecting therefrom radially, and has a number-average molecular weight of 2,000 to 1,000,000. The polymer segments have at least two different compositions. The block polymer is produced by at least two-stage free-radical polymerization of various polymerizable monomer components having different compositions by using a polyvalent mercaptan as the polymerization initiator.