Succinimide derivatives of 2,5-dimercapto-1,3,4-thiadiazole
CA 2079646 C · Owner: Karol, Thomas J. · Inventors: Karol, Thomas J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed are novel compounds prepared by reacting 2,5-dimercapto-1,3,4-thiadiazole with maleic anhydride and N-polyethylene amine-substituted succinimide. The compounds are dispersants or detergents, antiwear agents and antioxidants when incorporated into lubricating compositions. The novel compounds have the structural formula, (See formula I), wherein x=0 to 4 and R represents an alkenyl radical having from 8 to 400 carbon atoms.
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 October 1, 1992 and granted April 22, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 1, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 1, 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.