Polyol ester lubricants for hermetically sealed refrigerating compressors
CA 2136852 C · Owner: Schnur, Nicholas E. · 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
A high quality lubricant for hermetically sealed domestic air conditioner and refrigerator compressors, especially those using chlorine free hydrofluorocarbon refrigerant working fluids is provided by , mixed esters of hindered polyols most desirably, pentaerythritol, with a mixture of carboxylic acids including at least some isopentanoic acid along with either or both of iso-nonanoic acid and dibasic acids such as adipic.
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 May 27, 1993 and granted September 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 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.
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.