Lubricating compositions containing alkaline earth metal salts
CA 2079823 A1 · Owner: Shell Canada Limited · Inventors: Van De Kamp, Christinus C.; Udding, Anne C.; Boelens, Minne
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides a lubricating oil composition comprising a major proportion of a lubricating oil and a minor proportion of an alkaline earth metal salt selected from calcium and magnesium salts of a hydroxyalkyl sulphonic acid of the general formula:, (I), wherein each of R1, R2, R3 and R4 independently represents a hydrogen atom, or a linear or branched alkyl group, subject to the total number of carbon atoms in R1, R2, R3 and R4 taken together being in the range from 8 to 30; lubricating oil concentrates containing said salts; a process for preparing said composition: and the use of said salts as detergent additives in lubricating oil compositions. PS25004
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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
- Filed October 5, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 5, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 5, 2014.
- 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.