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Expired Canadian patentCanada

Distortion resistant polyester support for use as a phototool

CA 1291893 C · Owner: Bayless, John H. · Inventors: Bayless, John H.; Thirtle, James H.; Steinberg, Neil I.

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

Photosensitive element comprising a, polyester e.g. polyethylene terephthalate, at least 0.008 inch (0.20 mm) thick bearing on both sides a polymeric water-vapor barrier layer at least 0.00001 inch (0.00025 mm) thick of a copolymer of vinylidene chloride containing at least 80% by weight of vinylidene chloride and minor amounts of alkyl acrylate, and itaconic acid, and on at least one side of said barrier layer, a layer of a photosensitive material, e.g. silver halide emulsion, diazo or photopolymer. The element in the form of a phototool limits dimensional change within 6 hours after exposure to a 5% Relative Humidity change to no more than 0.001 inch (0.025 mm) per 24 inches (60.96 cm).

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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 November 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 12, 2008.
  • 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 18, 1986
GrantedNovember 12, 1991
Term endedNovember 12, 2008
Patent numberCA 1291893 C
Classification (IPC)G03F7/09 +1 more

Timeline

Timeline From CIPO dates

19871990199319961999200220052008Application filedDec 18, 1986Patent grantedNov 12, 1991Term endedNov 12, 2008

Sources & verification

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