Radiation-cured adhesive film having differential surface adhesion

Abstract

A radiation-cured adhesive film having differential adhesion on opposing surfaces of the adhesive layer is provided. The film comprises a backing layer having coated thereon a radiation-cured adhesive copolymer layer, said copolymer comprised of one or more urethane oligomers A, optionally one or more B monomers, and a macromer C defined by the formula X--(Y).sub.p --Z--R where X is a moiety copolymerizable with said urethane oligomer or capable of attachment to said copolymerized monomers A and B, Y is a divalent linking group, Z is a hydrophilic homo- or copolymeric moiety, R is a terminal group, and p is 0 or 1, said adhesive layer having a first surface portion in contact with said backing layer exhibiting an average peel adhesion value of at least 120 g/in and having a second opposing surface portion not in contact with said backing layer exhibiting an average peel adhesion value less than that exhibited by the first surface portion, and the ratio of the average peel adhesion values of said first and second surface portions being at least 2:1, respectively.

Dependencies are inferred from the claim text.