Foamed pressure sensitive tapes

摘要

The present invention relates to a pressure sensitive adhesive foam with a percentage of theoretical density less than 90 wherein the foam has an intrinsic adhesion of greater than about 1 N/cm and a compression set under constant deflection of less than about 60%. The present invention further includes a pressure sensitive adhesive foam comprising a thermoplastic block copolymer; a tackifying resin; an isocyanate terminated monomer or oligomer; a polymer comprising a backbone of selected from the group consisting of polybutadiene, polyester and polyether, wherein the polymer contains at least 2 active hydrogens capable of reacting with the isocyanate terminated monomer; and expandable particulate materials. The invention finally further comprises a method of forming the above film.