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Expired Canadian patentCanada

.alpha..beta..beta.-trifluorostyrene-based and substituted .alpha..beta..beta.-trifluorostyrene-based composite membranes

CA 2240495 C · Owner: Stone, Charles · Inventors: Stone, Charles; Steck, Alfred E.

CIPO record

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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 composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of .alpha..beta..beta.-trifluorostyrene, substituted .alpha..beta..beta.trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties the resultant composite membranes , are useful in electrochemical applications particularly as membrane , electrolytes in electrochemical fuel cells.

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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 January 3, 1997 and granted April 1, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 3, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 3, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJanuary 3, 1997
GrantedApril 1, 2003
Term endedJanuary 3, 2017
Patent numberCA 2240495 C
Classification (IPC)C08J5/22 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedJan 3, 1997Patent grantedApril 1, 2003Term endedJan 3, 2017

Sources & verification

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