Expired Canadian patentCanada
Two step interleaving method
CA 1213509 A · Owner: Ppg Industries Ohio, Inc. · Inventors: Duffer, Paul F.; Kelly, Joseph D.; Franz, Helmut
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method is disclosed for protecting glass surfaces in a stack of glass sheets by treating the surfaces with a stain-inhibiting organic hydroxy acid and separating adjacent surfaces with an interleaving material.
Read the whole patent
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 4, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 4, 2003.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 28, 1983
GrantedNovember 4, 1986
Term endedNovember 4, 2003
Patent numberCA 1213509 A
Classification (IPC)C03B40/02 +2 more
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.