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Expired Canadian patentCanada

Process for chemically treating papermaking belts

CA 2076525 C · Owner: Trokhan, Paul D. · Inventors: Trokhan, Paul D.

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 process for improving the life of papermaking belts containing a cured photosensitive polymeric resin is disclosed. The process includes the continuous application of an effective amount of chemical compounds capable of slowing down the degradation rate of the photosensitive polymeric resin to the belt's surface during the papermaking operation. Preferably the chemical, compounds are antioxidants which inhibit or retard oxidation of the cured resin and its ensuing degradative effects.

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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 April 8, 1991 and granted January 12, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 8, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 8, 2013.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 8, 1991
GrantedJanuary 12, 1999
Term endedApril 8, 2011
Patent numberCA 2076525 C
Classification (IPC)D21F1/30 +1 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedApril 8, 1991Patent grantedJan 12, 1999Term endedApril 8, 2011

Sources & verification

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