Patent ID: 8691924

Claim:
An optical-use pressure-sensitive adhesive sheet, which comprises an acrylic pressure-sensitive adhesive layer containing an acrylic polymer formed of one or more monomer ingredients containing, as an indispensable monomer ingredient, a monomer of which homopolymer has a glass transition temperature of not lower than −10° C. in an amount of 5 to 60% by weight, a carboxyl group-having monomer in an amount of at most 0.5% by weight, a hydrophilic monomer, which contains N-vinyl-2-pyrrolidone and a hydroxylalkyl (meth)acrylate, in an amount of from 3 to 70% by weight relative to the total (100% by weight) of the entire monomer ingredients for forming the acrylic polymer, and at least a linear or branched alkyl group-having alkyl (meth)acrylate where the alkyl group has from 6 to 10 carbons or alkoxyalkyl (meth)acrylate in an amount of 50% by weight or more relative to the total (100% by weight) of the entire monomer ingredients for forming the acrylic polymer, wherein said sheet having a moisture content of at least 0.65% by weight after stored in an environment at 60° C. and 95% RH for 120 hours.