Grafted viscosity index improver
CA 2015059 C · Owner: Exxon Chemical Patents Inc. · Inventors: Johnston, John E.; Chung, David Yen-Lung; Struglinski, Mark Joseph
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Oil soluble grafted ethylene-alpha-olefin copolymer useful as a viscosity modifier for oleaginous compositions comprising:, (i) backbone copolymer of ethylene and at least one other alpha-olefin monomer, said copolymer comprising intramolecularly, heterogeneous copolymer chains containing at least one crystallizable segment of methylene units and at least one low crystallinity ethylene-alpha-olefin copolymer segment wherein said at least one crystallizable segment comprises at least about 10 weight percent of said copolymer chain and contains at least about 57 weight percent ethylene wherein said low crystallinity segment contains not greater than about 53 weight percent ethylene, and …
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 April 20, 1990 and granted January 26, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 20, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 20, 2012.
- 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.