| abstract |
The present invention relates to a composition of matter consisting of a polymer of a rubbery nature, which is selected from the group consisting of I. a biblock copolymer of a high vinyl trans-polymer high content copolymer . II. a blend of a high trans content copolymer and a high vinyl content polymer and III. a blend or mixture of a biblock copolymer of a high trans copolymer-high vinyl polymer, a high trans copolymer and a high vinyl polymer. a.- wherein the high trans content copolymer is a 1,3-butadiene copolymer, and at least one copolymerizable monomer selected from the group consisting of styrene and isoprene, has a glass transition temperature of less than from about 75 to 85 percent trans units and no more than about 8 percent vinyl units in the butadiene segments, and constitutes about 25 to 80 percent by weight of the composition. b.- where the high vinyl content polymer is at least one polymer selected from the group consisting of homo-polybutadiene and butadiene-1,3 copolymers and at least one monomer, which is selected from the group consisting of styrene and isoprene, has a glass transition temperature greater than about -70 degrees C. and no greater than about -35 degrees C. and has from about 40 to 80 percent vinyl units in the glass segments. butadiene, and c.- wherein in that composition the total amount of styrene and/or isoprene is from about 5 to 20 percent by weight, and the total amount of vinyl groups is from about 30 to 60 percent. |