ACRYLIC COPOLYMER, ACRYLIC PRESSURE-SENSITIVE ADHESIVE COMPOSITION, ACRYLIC PRESSURE-SENSITIVE ADHESIVE TAPE OR SHEET, AND ACRYLIC ADHESIVE COMPOSITION

摘要

An acrylic copolymer having polymer segments differing in polarity and glass transition point. The combination of these polymer segments differing in polarity and glass transition point can be easily regulated, and the copolym er has a high degree of freedom of design. It is usable in a wide range of applications. The acrylic copolymer is obtained by copolymerizing (a) an alk yl (meth)acrylate having a C1-14 alkyl group, (b) an olefin (co)polymer terminated by a radical-polymerizable unsaturated double bond, and (c) a polymer terminated by a radical-polymerizable unsaturated double bond and having a number-average molecular weight of 2,000 to 30,000 and a glass transition temperature of 30~C or higher, and comprises a backbone polymer consisting mainly of units of the alkyl (meth)acrylate (a) and, grafted to t he backbone, polymeric branches which have low polarity and differ in glass transition point.