Star-shaped dispersant viscosity index improver
CA 1108792 A · Owner: Shell Canada Limited · Inventors: Kiovsky, Thomas E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Lubricating oil additives having both dispersant and viscosity index-improving properties are prepared by reacting a selectively hydrogenated star-shaped polymer having at least four areas of polymers or co-polymers of dienes and monoalkenyl arenes with an alpha-beta unsaturated carboxylic acid or derivative, and then reacting the resulting intermediate with an amine and/or alkane polyol.
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
- Granted September 8, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 8, 1998.
- 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.