Preparation of modified star polymers and the use of such polymers as luboil additives
CA 2006111 C · Owner: Klaver, Gerarda J. · Inventors: Klaver, Gerarda J.; Van Zon, Arie
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for preparing a grafted star polymer which comprises contacting a nitrogen-containing polymerizable organic polar compound with a star polymer in the presence of a free radical polymerization initiator; characterised in that the reaction is carried out in a mineral oil solvent and as coupling inhibitor, either a chain transfer agent a pi-electron donor, or a comonomer, together with the modified, hydrogenated star polymers thus produced, and their use as luboil additives.
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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 December 20, 1989 and granted October 17, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 2011.
- 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.