Patent ID: 7645813
Filing Date: 2010-01-12
Classification: A61K,A61L,C08F,C08K,C08L,C09J,Y10T

Abstract:
1. A transdermal pressure-sensitive adhesive comprising: (a) 100 parts by weight of a copolymer prepared by a process of solution polymerization involving simultaneous polymerization of four monomers including an olefinic macromonomer selected from the group consisting of polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-butylene copolymer, alkyl (meth)acrylate, at least one first vinyl monomer selected from the group consisting of n-vinyl-2-pyrrolidone, vinyl acetate and alkoxyalkyl (meth) acrylate, and a second vinyl monomer having a functional group selected from the group consisting of hydroxyl group, carboxyl group, glycidyl group, and amino group, said copolymer consisting of: 20 to 65% by weight of said olefinic macromonomer, 20 to 40% by weight of said alkyl (meth)acrylate, 10 to 40% by weight of said first vinyl monomer and 0.5 to 25% by weight of said second vinyl monomer, thereby forming a random copolymer from these monomers, said copolymer having a molecular weight (in terms of polystyrene and as determined by gel permeation chromatography (GPC)) with a two-peak distribution (with the proviso that when the copolymer is to be post-cured, the distribution is one as determined before the post cure), and (b) 20 to 250 parts by weight of a softener which is compatible with the copolymer and liquid or pasty at room temperature and has a boiling point of 250° C. or above (with the proviso that when the content of the softener (b) exceeds 80 parts by weight, the copolymer must be post- cured).