PRESSURE-SENSITIVE ADHESIVE

摘要

PURPOSE:To obtain a pressure-sensitive adhesive having excellent tack and cohesive force, by using a graft polymer having a main chain composed of a specific acrylic ester and side chains composed of a specific high-molecular compd. as a component. CONSTITUTION:A pressure-sensitive adhesive comprises a graft polymer having a main chain composed of an acrylic polymer having a glass transition point not higher than 0 deg.C and composed of at least 50wt.% acrylic ester obtd. by using a 14C or lower primary or secondary alcohol and side chains composed of a compd. having a weight-average MW not lower than 1,000 and an SP value wherein a difference in the SP value between the main chain and the side chain is 6 or smaller. The alcohol component in the acrylic ester or esters for the acrylic polymer has an average carbon atom of pref. 4-12 from the viewpoint of the flexibility of the acrylic polymer. The graft polymer has an acrylic polymer content of 50wt.% or above as the main chain and a weight- average MW of pref. 100,000 or above. The SP value is determined by using a formula representing the total value (SIGMAEi) of gram molecule suction constant/ the total value (SIGMAVi) of gram molecule volume.