Patent ID: 8178198

Claim:
An adhesive sheet comprising: a substrate; and an energy-ray curable adhesive layer formed on said substrate, said energy-ray curable adhesive layer comprising a mixture of an energy-ray curable urethane acrylate and an energy-ray curable acrylic copolymer, said energy-ray curable adhesive layer having higher adhesion strength prior to curing with an energy-ray than after curing with the energy ray, said energy-ray curable acrylic copolymer being a copolymer of at least a (meth)acryloyl morpholine in total of 1 to 30 weight percent of all monomers used to form said energy-ray curable acrylic copolymer, and said energy-ray curable acrylic copolymer comprising a side chain comprising an unsaturated group; and the storage modulus of said energy-ray curable adhesive layer is between 0.04 MPa and 0.11 MPa, and the value of tan δ at 25 degrees Celsius is greater than or equal to 0.6, when said energy-ray curable adhesive layer is not cured by energy-ray.