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Expired Canadian patentCanada

Method for making cyclic poly(siloxane)s

CA 1333733 C · Owner: Lee, Julia Lam · Inventors: Lee, Julia Lam; Crivello, James Vincent

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 is provided for making cyclic poly(siloxane) by incrementally contacting linear polysiloxane with a fixed bed cracking catalyst such, as an acidic Zeolite under reduced pressure. The resulting volatile cyclic poly(siloxane) is then recovered.

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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 December 27, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 27, 2011.
  • 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 20, 1989
GrantedDecember 27, 1994
Term endedDecember 27, 2011
Patent numberCA 1333733 C
Classification (IPC)C08G77/38 +2 more

Timeline

Timeline From CIPO dates

19901993199619992002200520082011Application filedJuly 20, 1989Patent grantedDec 27, 1994Term endedDec 27, 2011

Sources & verification

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