Patent ID: 7348376
Filing Date: 2008-03-25
Classification: A61L,C08F,C08L,C09J

Abstract:
1. An adhesive comprising an amorphous polyolefin and a selectively hydrogenated block copolymer having an S block and an E or E 1 block and having the general formula: or mixtures thereof, wherein: (a) prior to hydrogenation the S block is a polystyrene block; (b) prior to hydrogenation the E block is a polydiene block, selected from the group consisting of polybutadiene and mixtures of polybutadiene and polyisoprene, having a molecular weight of from 40,000 to 120,000 daltons; (c) prior to hydrogenation the E (d) n is an integer having a value of 2 to 6 and X is a coupling agent residue; (e) the styrene content of the block copolymer is from 10 percent to 40 weight percent; (f) the vinyl content of the polydiene block prior to hydrogenation is from 72 to 90 mole percent; (g) the block copolymer includes less than 25 weight percent lower molecular weight units having the general formula: wherein S, E and E 1 are as already defined; (h) subsequent to hydrogenation about 0-10% of the styrene double bonds have been hydrogenated and at least 80% of the conjugated diene double bonds have been hydrogenated; and (i) the molecular weight of each of the S blocks is from 4,000 to 12,000 daltons; (j) the amorphous polyolefin is selected from the group consisting of a copolymer of propylene and 1-butene or a terpolymer also having ethylene, and having a viscosity of from about 400 cps to about 8500 cps at 190° C. and a softening point of from about 95° C. to about 125° C., a propylene/ethylene copolymer having a viscosity of from about 400 cps to about 8500 cps at 190° C. and a softening point of from about 125° C. to about 165° C., and a blend of homopolypropylene and propylene/ethylene copolymer having a viscosity of from about 400 cps to about 8500 cps at 190° C. and a softening point of from about 125° C. to about 165° C.