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Expired Canadian patentCanada

Acidified powdered interleaving

CA 1255454 A · Owner: Ppg Industries, Inc. · Inventors: Kelly, Joseph D.; Duffer, Paul F.; Franz, Helmut

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 method and composition utilizing porous particulate interleaving material treated with a strong organic acid are disclosed to reduce staining of stacked glass sheets.

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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 June 13, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 13, 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.
FiledJuly 15, 1985
GrantedJune 13, 1989
Term endedJune 13, 2006
Patent numberCA 1255454 A
Classification (IPC)C03C17/28 +2 more

Timeline

Timeline From CIPO dates

1986198919921995199820012004Application filedJuly 15, 1985Patent grantedJune 13, 1989Term endedJune 13, 2006

Sources & verification

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