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:
Dec. 24, 1996
Filed:
Jun. 03, 1993
Bridgestone Corporation, Tokyo, JP;
Abstract
In one of several methods of producing polybutadiene or a butadiene-styrene copolymer with an organolithium initiator, an organotin compound such as tetraallyltin, tetrabenzyltin and tetraphenyltin is added to the polymerization system in a period of growth of the polymer chain between a time immediately after a start of the polymerization to a time before an end of the polymerization. In another of the methods, tin tetrachloride or tin dichloride is added at an earlier time after a start of the polymerization. A polymer comprising a considerable amount of high molecular weight polymer containing the chain having a tin-carbon linkage is formed. A rubber composition for tires comprises specified amounts of the polymer described above, natural rubber, carbon black and vulcanizing agents. The rubber composition has a small loss factor and excellent fracture properties. The rubber composition provides a tire having excellent wear resistance, low rolling resistance and wet skid resistance without impairing fracture properties. In addition, the rubber composition is inexpensive.