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:
Nov. 06, 2001
Filed:
Sep. 01, 2000
Scott McDowell Christian, Clinton, OH (US);
Zhengfang Xu, Stow, OH (US);
Michael Lester Kerns, Elyria, OH (US);
The Goodyear Tire & Rubber Company, Akron, OH (US);
Abstract
This invention discloses a process for synthesizing random styrene-isoprene rubber comprising: (1) continuously charging isoprene, styrene, an initiator, and a solvent into a first polymerization zone, (2) allowing the isoprene and styrene to copolymerize in the first polymerization zone to total conversion of 60 to 95 percent to produce a polymer cement containing living styrene-isoprene chains, (3) continuously charging the polymer cement containing living styrene-isoprene chains and additional isoprene monomer into a second polymerization zone, wherein from 5 to 40 percent of the total amount of isoprene changed is charged into the second polymerization zone, (4) allowing the copolymerization to continue in the second polymerization zone to a conversion of the isoprene monomer of at least 90 percent wherein the total conversion of styrene and isoprene in the second polymerization zone is limited to a maximum of 98 percent, (5) withdrawing a polymer cement of random styrene-isoprene rubber having living chain ends from the second reaction zone, (6) killing the living chain ends on the random styrene-isoprene rubber, and (7) recovering the random styrene-isoprene 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 2 percent more than the total amount of styrene bound into the rubber.