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Expired Canadian patentCanada

Lens composition, article and method of manufacture

CA 1261998 A · Owner: Paragon Optical, Inc. · Inventors: Ratkowski, Donald J.

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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 copolymer composition especially suited for, fabricating optical lenses comprising a copolymer of copolymerized comonomers which include in weight percent about one to about twenty percent by weight of an acryloxyalkylsilanol; about one to about fifteen percent of a polyacryloxyalkylpolysiloxane; about thirty to about seventy five percent of an siloxy substituted ester of acrylic or methacrylic acid; from about one to about 35 percent of an alkyl or cycloalkyl acrylate or methacrylate having from one to twenty carbon atoms; from about one to about twenty percent of a polyol diacrylate; and from about one to about twenty percent of a wetting monomer. Contact lenses and contact lens buttons …

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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 September 26, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 26, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 4, 1985
GrantedSeptember 26, 1989
Term endedSeptember 26, 2006
Patent numberCA 1261998 A
Classification (IPC)C08F230/08 +2 more

Timeline

Timeline From CIPO dates

1986198919921995199820012004Application filedDec 4, 1985Patent grantedSep 26, 1989Term endedSep 26, 2006

Sources & verification

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