Patent Yard Sign in
Expired Canadian patentCanada

Polycarbonate and use thereof

CA 2087134 C · Owner: Fujimoto, Tadaaki · Inventors: Fujimoto, Tadaaki; Takahata, Kazunori; Tanaka, Masahide

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

The polycarbonate of the invention is a polycarbonate derived from adducts such as propylene oxide adducts of polyglycerols. The lubricating oil of the invention comprises this polycarbonate, and if necessary a specific, polycarbonate having a -C2H4O- group and/or a -CH2CH(CH3)Ogroup in its main chain. The lubricating oil of the invention can be used as a lubricating oil for refrigerators such as automotive air-conditioner and electric refrigerator. In particular, the lubricating oil of the invention is suitable as a lubricating oil for refrigerator wherein high-viscosity lubricating oil is used, for example, lubricating oil for automotive rotary air-conditioner, and also suitable as …

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

  • Filed January 12, 1993 and granted March 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 12, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 12, 2015.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJanuary 12, 1993
GrantedMarch 18, 1997
Term endedJanuary 12, 2013
Patent numberCA 2087134 C
Classification (IPC)C08G64/02 +2 more

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedJan 12, 1993Patent grantedMarch 18, 1997Term endedJan 12, 2013

Sources & verification

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