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US 4,391,949 AGranted
Asymmetric block copolymers and corresponding adhesive formulations
AssigneeShell Oil Company
InventorDavid J. St. Clair
Life of this patent
Estimating the term…
Abstract
A novel block copolymer having particular utility in adhesive compositions has the structure (A--B).sub.x Y--C).sub.z where A is a poly(monoalkenyl) block, B and C are poly(conjugated diene) polymer blocks, Y is the residue of a multifunctional coupling agent, and x plus z is greater than 6. Also disclosed are adhesive compositions containing such block copolymers.
Claims17
A block copolymer having the star-shaped, asymmetrical structure
- (A--B).sub.x Y--C).sub.z
- where A is a polymer block of a monoalkenyl arene, B is a polymer block of a conjugated diene, C is a polymer block of a conjugated diene, Y is the residue of a multifunctional coupling agent, the sum of x plus z is greater than 6 and less than about 25, the ratio of x to z is between about 5 to 1 and about 1 to 5, the molecular weight of each block A is between about 3,000 and about 30,000, the molecular weight of each block B is between about 15,000 and about 100,000, and the molecular weight of each block C is between about 15,000 and about 100,000.
A selectively hydrogenated block copolymer having the star-shaped, asymmetrical structure
- (A--B).sub.x Y--C).sub.z
- where A is a polymer block of a monoalkenyl arene, B is a substantially hydrogenated polymer block of a conjugated diene, C is a substantially hydrogenated polymer block of a conjugated diene, Y is the residue of a multifunctional coupling agent, the sum of x plus z is greater than 6 and less than about 25, the ratio of x to z is between about 5 to 1 and about 1 to 5 and the molecular weight of each block A is between about 3,000 and about 30,000, the molecular weight of each block B is between about 15,000 and about 100,000, and the molecular weight of each block C is between about 15,000 and about 100,000.
Dependencies are inferred from the claim text.