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Expired Canadian patentCanada

Method for manufacturing hydrophilic contact lenses

CA 2020196 C · Owner: Hahn, Dennis · Inventors: Hahn, Dennis; Johansson, Gary A.; Ruscio, Dominic V.

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

An improved method for manufacturing contact lenses wherein monomer or comonomer mixture is placed into a mold cavity and subjected to polymerization conditions to form a polymerized shape of desired shape wherein the improvement comprises the inclusion of a release agent in the monomeric mixture wherein said release agent comprises less than about three weight percent of said monomeric mixture and is chosen from a mixture of hydrophilic polymers with lipophilic compounds.

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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 June 29, 1990 and granted September 2, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 29, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 29, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 29, 1990
GrantedSeptember 2, 1997
Term endedJune 29, 2010
Patent numberCA 2020196 C
Classification (IPC)B29D11/00 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJune 29, 1990Patent grantedSep 2, 1997Term endedJune 29, 2010

Sources & verification

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