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Expired Canadian patentCanada

Clear, high impact block copolymers

CA 1339165 C · Owner: Dougherty, David J. · Inventors: Sarkar, Sunil B.; Dougherty, David J.

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 continuous process as disclosed which produces a clear high impact block copolymer having a vinyl aryl monomer content of at least 70 percent of the block copolymer. This continuous process involves the continuous preparation of a multiblock copolymer which comprises the alternate feeding of monomer streams to a reaction zone wherein a product stream is withdrawn from the polymerization system at the same rate as the total rate of the feed streams.

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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 July 29, 1997. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 29, 2014.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 30, 1987
GrantedJuly 29, 1997
Term endedJuly 29, 2014
Patent numberCA 1339165 C
Classification (IPC)C08F297/04

Timeline

Timeline From CIPO dates

198819911994199720002003200620092012Application filedNov 30, 1987Patent grantedJuly 29, 1997Term endedJuly 29, 2014

Sources & verification

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