| abstract |
An adhesive sheet having an adhesive agent layer made from an adhesive agent composition comprising (A) a polyisobutylene resin having a mass average molecular weight of 20,000 or more, (B) a styrene copolymer and (C) an adhesiveness-imparting agent having a softening point of 135˚C or lower, wherein the component (B) comprises at least one compound selected from the group consisting of a styrene-butadiene-styrene triblock copolymer (SBS), a styrene-block-(ethylene-co-butylene)-block-styrene triblock copolymer (SEBS), a styrene-isobutylene diblock copolymer (SIB) and a styrene-isobutylene-styrene triblock copolymer (SIBS). The adhesive sheet has excellent adhesion performance, an excellent effect of preventing the invasion of water, and good transparency. |