Lubrication for refrigerant heat transfer fluids
CA 2084786 C · Owner: Henkel Corporation · Inventors: Schnur, Nicholas E.; Zehler, Eugene R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Esters and mixtures of esters of polyhydric alcohols. e.g.. of pentaerythritol in which at least 22 number percent of the acyl groups in the esters are either branched or contain no more than six carbon atoms are effective lubricants and/or lubricant base stocks for chlorine-free fluorocarbon refrigerant heat transfer fluids particularly for chlorine-free heat transfer fluids such as Refrigerant 134a (1,1,1,2-tetrafluoroethane).
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 March 11, 1991 and granted May 25, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 11, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 11, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.