Branched styrene-butadiene copolymers and pneumatic tires using the same
CA 1234950 A · Owner: Bridgestone Tire Company Limited · Inventors: Yoshimura, Yoshito; Fujimaki, Tatsuo; Oshima, Noboru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A branched styrene-butadiene copolymer and a pneumatic tire using the same as a tread base rubber are disclosed. This copolymer is produced by coupling an active styrene-butadiene copolymer anion which is, obtained by polymerizing styrene and butadiene in a hydrocarbon solvent in the presence of ether or a tertiary amine and an initiator of an organolithium compound with, a tin halide compound. In the copolymer the ratio of, branched copolymer connected with tin-butadienyl bond is at least 20% by weight, and the content of bound styrene is not less than 3% by weight but less than 25% by weight and the content of vinyl bond in butadiene portion is not less than 30% but less than 50%. - 30 -
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted April 5, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 5, 2005.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.