US 5,393,841 A · Dissimilar arm asymmetric radial or star block copolymers for adhesives and sealants

Abstract

Radial or star asymmetric block copolymer of the following formulae and improved adhesive and sealant compositions containing them (I) (A--HD).sub.x --Y--(UD).sub.z or (II) (UD--A--HD).sub.x --Y or (III) ((UD).sub.y --A--HD).sub.x --Y--(UD).sub.z wherein A is a vinyl aromatic hydrocarbon block having a molecular weight of from 4000 to 20,000, HD is a hydrogenated conjugated diene block having a molecular weight of from 10,000 to 100,000, Y is a multifunctional coupling agent, UD is an unhydrogenated conjugated diene block having a molecular weight of from 1000 to 80,000, x is an integer from 2 to 20, y is 0 or 1, z is an integer from 1 to 10, and x+z ranges from 3 to 30.

Claims9

Dependent claims

Radial or star asymmetric block copolymers of the formula

(A--HD).sub.x --Y--(UD).sub.z
wherein A is a vinyl aromatic hydrocarbon block having a peak molecular weight as determined by gel permeation chromatoqraphy of from 4000 to 20,000, HD is a hydrogenated conjugated diene block having a peak molecular weight as determined by gel permeation chromatography of from 10,000 to 100,000, Y is a multifunctional coupling agent, UD is an unhydrogenated conjugated diene block having a peak molecular weight as determined by gel permeation chromatography of from 1000 to 80,000, the block copolymer has a vinyl aromatic hydrocarbon content of from 4 to 35 percent by weight, x is an integer from 2 to 20, z is an integer from 1 to 10, and x+z ranges from 3 to 30.

Dependencies are inferred from the claim text.

Dissimilar arm asymmetric radial or star block copolymers for adhesives and sealants

Life of this patent

Dissimilar arm asymmetric radial or star block copolymers for adhesives and sealants

Life of this patent

Abstract

Claims9