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Expired Canadian patentCanada

Silicone-modified aliphatic polyester

CA 2135347 C · Owner: Smith, Marc L. · Inventors: Smith, Marc L.; Holzrichter, Edward J.; Lewarchik, Ronald J.

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

A silicone/polyester adduct comprises between about 5 and about 30 wt% of silicone adducted to between about 70 and about 95% polyester chains formed from polyfunctional acids plus polyfunctional acids and/or anhydrides. At least about 50 mole percent of the polyfunctional acids and/or anhydrides are cycloaliphatic.

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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

  • Filed November 8, 1994 and granted December 8, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 8, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 8, 2016.
  • 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 8, 1994
GrantedDecember 8, 1998
Term endedNovember 8, 2014
Patent numberCA 2135347 C
Classification (IPC)C08G77/44 +2 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedNov 8, 1994Patent grantedDec 8, 1998Term endedNov 8, 2014

Sources & verification

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