Tapered block copolymers
AssigneeThe Dow Chemical Company
InventorLu H. Tung
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Abstract
Tapered block copolymers of monovinylidene aromatic monomers and conjugated diene monomers having an isolated polymerized monovinylidene atomatic content of from 30 to 75 percent, hydrogenated derivatives thereof and a process for their preparation.
Claims13
A hydrogenated, tapered, block copolymer corresponding to the formula AB(BA).sub.n wherein A is a block of a monovinylidene aromatic monomer and B is a partially or fully hydrogenated block of a conjugated diene, and n is a number from 0 to 6, said block copolymer being further characterized in that at least one of the junctions between an A block and a B block is tapered such that the total amount of isolated, polymerized monovinylidene aromatic units in the polymer is from 30 to 75 percent, said block copolymer having a melt index from 1 to 40.
A block copolymer corresponding to the formula AB(BA).sub.n wherein A is a block of a monovinylidene aromatic monomer and B is a block of butadiene, and n is a number from 0 to 6, said block copolymer being further characterized in that at least one of the junctions between an A block and a B block is tapered such that the total amount of isolated, polymerized monovinylidene aromatic units in the polymer is from 30 to 75 percent and the 1,2-vinyl content of the polybutadiene block of the copolymer is from 35 to 55 percent, said block copolymer having a melt index from 1 to 40.
Dependencies are inferred from the claim text.