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Expired Canadian patentCanada

Polybutadiene and process for preparing the same

CA 1259745 A · Owner: Sumitomo Chemical Company, Limited · Inventors: Imai, Akio; Saito, Masatoshi; Okamoto, Yasushi

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Abstract From the Canadian patent

A polybutadiene having an average 1,2-bond content of 18 to 32% by mole, a branched polymer chain content of 60% by weight or more and a Mooney viscosity at 100°C of 40 to 90, the viscosity of a 5% by weight concentration solution of this polybutadiene in styrene at 25°C being 60 to 90 cps, and a process for preparing the polybutadiene comprising starting the polymerization of 1,3-butadiene in an inert hydrocarbon solvent in the presence of a Lewis basic compound and an organolithium compound, the latter compound being in an amount of 0.5 to 3 millimoles per 100 g of 1,3-butadiene at a temperature, selected from the range of 30 to 80°C carrying out the, polymerization by controlling the …

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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 September 19, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 19, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 26, 1985
GrantedSeptember 19, 1989
Term endedSeptember 19, 2006
Patent numberCA 1259745 A
Classification (IPC)C08F136/06 +1 more

Timeline

Timeline From CIPO dates

1986198919921995199820012004Application filedFeb 26, 1985Patent grantedSep 19, 1989Term endedSep 19, 2006

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.