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Expired Canadian patentCanada

Process and system for preparing random copolymers having low vinyl contents

CA 1298029 C · Owner: Firestone Tire & Rubber Company (The) · Inventors: Hall, James Edward

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A process is disclosed herein for preparing randomized copolymers of conjugated dienes and vinyl aromatic hydrocarbons having low vinyl contents by utilizing an anionic initiator system comprising alkali metal trihydrocarbyl magnesiates optionally together with an organolithium compound.

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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 March 24, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 24, 2009.
  • 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 2, 1987
GrantedMarch 24, 1992
Term endedMarch 24, 2009
Patent numberCA 1298029 C
Classification (IPC)C08F236/10 +1 more

Timeline

Timeline From CIPO dates

19881991199419972000200320062009Application filedFeb 2, 1987Patent grantedMarch 24, 1992Term endedMarch 24, 2009

Sources & verification

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