Patent ID: 8597786

Claim:
A pressure-sensitive adhesive composition comprising, as a main ingredient, a monomer mixture or an acrylic copolymer material obtained by at least partially polymerizing the monomer mixture, said monomer mixture comprising: at least one monomer (monomer m1) selected from alkyl (meth)acrylates represented by the following formula (I) in an amount of 50 to 85% by weight based on a total amount of the monomer mixture: CH 2 C(R 1 )COOR 2 (I) wherein R 1 is a hydrogen atom or a methyl group, and R 2 is an alkyl group having 1 to 20 carbon atoms, N-(2-hydroxyethyl)acrylamide (monomer m2) in an amount of 2 to 12% by weight based on the total amount of the monomer mixture, and N-vinyl-2-pyrrolidone (monomer 3), in an amount of 10 to 40% by weight based on the total amount of the monomer mixture; and said monomer mixture comprising substantially no carboxyl group-containing monomer.