The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 1993
Filed:
Apr. 29, 1991
Pascal Nicol, Pau, FR;
Laurence Orozco, Billere, FR;
Elf Atochem S.A., , FR;
Abstract
A process for manufacturing block copolymers comprising anionically polymerizing a vinyl aromatic hydrocarbon mononer in solution in an aromatic hydrocarbon solvent capable of giving a homogeneous medium until attaining a homogeneous medium with a viscosity greater than 300 Pa.s at 20.degree. C. for a concentration of polymer in the aromatic hydrocarbon solvent between 60 and 90% by weight and then, after introduction of a conjugated diene, carrying out a copolymerization until a homogeneous medium is attained have a viscosity greater than 300 Pa.s at 90.degree. C. for a concentration of copolymer in the aromatic hydrocarbon solvent between 70 and 90% by weight, without the viscosity exceeding 3,000 Pa.s in either of the two polymerization steps.