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. 27, 1976
Filed:
Dec. 26, 1973
Shingo Futamura, Seville, OH (US);
Thomas Chester Bouton, Akron, OH (US);
The Firestone Tire & Rubber Company, Akron, OH (US);
Abstract
The process disclosed herein involves the preparation of butadiene-styrene copolymers of improved green strength and low running temperature when used in tire compositions, which comprises the steps of polymerizing a mixture of butadiene and styrene in a hydrocarbon solvent having a lithium alkyl initiator therein while the monomer mixture is fed into the polymerization system at a rate slow enough to effect random copolymerization in the resulting polymer backbone, effecting a high degree of branching by conducting the polymerization at a temperature of 90.degree.-175.degree. C. (190.degree.-347.degree. F.) and effecting the final 10-50 percent of the polymerization with a monomer portion containing a higher proportion of styrene than is incorporated into the polymer-backbone, thereby effecting the formation of block polystyrene at the terminals of a plurality of branches. This copolymer of improved green strength and low running temperature is very useful in tire compositions.