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:
Apr. 17, 2007
Filed:
Apr. 30, 2004
Pierre Robert, Perignat-les-Sarlieves, FR;
Jean-michel Favrot, Cournon-d'Auvergne, FR;
Pierre Lesage, Clermont-Ferrand, FR;
Pierre Robert, Perignat-les-Sarlieves, FR;
Jean-Michel Favrot, Cournon-d'Auvergne, FR;
Pierre Lesage, Clermont-Ferrand, FR;
Michelin Recherche et Technique S.A., Granges-Paccot, CH;
Abstract
A preparation process for a copolymer having two blocks usable in a sulphur-cross-linkable rubber composition of reduced hysteresis in the cross-linked state, such a block copolymer in which one of the blocks is a polyisoprene and the other a diene elastomer other than a polyisoprene, and this rubber composition for tire treads. A process for the preparation of this copolymer involves copolymerizing one or more monomers including a conjugated diene other than isoprene using a catalytic system including at least one hydrocarbon solvent, a compound A of a metal of group IIIA, a compound B of an alkaline-earth metal and a polymeric initiator C having a C—Li bond which is constituted of a monolithiated polyisoprene intended to form the polyisoprene block, the number-average molecular weight Mof the polyisoprene block being between 2,500 and 20,000 g/mol. A copolymer is obtained in which the block composed of the diene elastomer has a number-average molecular weight Mof between 65,000 and 350,000 g/mol and a content of trans-1,4 linkages equal to or greater than 70%.