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. 16, 2002
Filed:
Jul. 18, 2000
Michael Lester Kerns, Elyria, OH (US);
Zhengfang Xu, Stow, OH (US);
Scott McDowell Christian, Clinton, OH (US);
The Goodyear Tire & Rubber Company, Akron, OH (US);
Abstract
This invention discloses a process for synthesizing random styrene-butadiene rubber comprising: (1) continuously charging 1,3-butadiene, styrene, an initiator, and a solvent into a first polymerization zone, (2) allowing the 1,3-butadiene and styrene to copolymerize in the first polymerization zone to total conversion of 60 to 90 percent to produce a polymer cement containing living styrene-butadiene chains, (3) continuously charging the polymer cement containing living styrene-butadiene chains and additional 1,3-butadiene monomer into a second polymerization zone, wherein from 20 to 40 percent of the total amount of 1,3-butadiene changed is charged into the second polymerization zone, (4) allowing the copolymerization to continue in the second polymerization zone to a conversion of the 1,3-butadiene monomer of at least 90 percent, wherein the total conversion of styrene and 1,3-butadiene in the second polymerization zone is limited to a maximum of 95 percent, (5) withdrawing a polymer cement of random styrene-butadiene rubber having living chain ends from the second reaction zone, (6) killing the living chain ends on the random styrene-butadiene rubber, and (7) recovering the random styrene-butadiene rubber from the polymer cement, wherein the copolymerizations in the first polymerization zone and the second polymerization zone are carried out at a temperature which is within the range of 70° C. to 100° C., and wherein the amount of styrene charged into the first polymerization zone is at least 5 percent more than the total amount of styrene bound into the rubber.