| 摘要 |
A normally nontacky but potentially tacky adhesive lift-off tape which comprises an adhesive film composition which normally exhibits a plastic nontacky state but is convertible to an elastomeric tacky state by the application of substantial stress, i.e., stretching sufficiently or striking with typewriter type, as well as the process of applying the said adhesive film. This film composition consists essentially of thermoplastic and elastomeric A-B block copolymers wherein the A-blocks are thermoplastic and the B-blocks are elastomeric and about 20-120 parts per one hundred parts by weight of the block copolymers of certain normally solid resins adapted to associate principally with the thermoplastic A-blocks of said copolymers. In these copolymers the A-blocks are derived from styrene or styrene homologues and the B-blocks are derived from conjugated dienes or lower alkenes. The normally solid resins preferably are selected from the group consisting of alpha-methylstyrene-vinyl toluene copolymers and coumarone-indene copolymers.
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