Lift-off tape and process

Claim 1

A typewriter lift-off tape for removing typed ink impressions comprising a non-adhesive backing layer and a normally non-tacky elastic adhesive layer on one major surface of the backing layer, said backing layer being relatively inextensible and said adhesive layer being relatively extensible; wherein in said tape, the adhesive layer (1) comprises an adhesive composition consisting essentially of (a) thermoplastic and elastomeric A-B block copolymers in which (i) the A-blocks are thermoplastic being derived from styrene or styrene homologs, possess a number average molecular weight of at least about 6,000, and constitute about b 5 to about 50 percent by weight of the block copolymer, and (ii) the B-blocks are elastomeric being derived from conjugated dienes or lower alkenes and possess a number average molecular weight in the range of about 45,000 to 180,000, and (b) normally solid resins adapted to associate principally with the thermoplastic A-blocks of said copolymers, said resins being employed in an amount of from about 40 to about 90 parts by weight per 100 parts by weight of the block copolymer; and (2) exhibits a plastic state at low elongations and an elastic state at high elongations, and has the property of being converted from a normally non-tacky and plastic state to a tacky and elastic state when struck by a typewriter key.