Method for purifying ethylene-.alpha.-olefin copolymer
CA 2057526 A1 · Owner: Sumitomo Chemical Co. Ltd. · Inventors: Sugimori, Kiyoyuki; Yamamoto, Keisaku; Saba, Hayato
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for purifying an ethylene-.alpha.-olefin copolymer obtained by polymerizing ethylene with an .alpha.olefin having at least 3 carbon atoms, or ethylene with an .alpha.-olefin having at least 3 carbon atoms and a nonconjugated diene compound, in a hydrocarbon solvent in the presence of a catalyst comprising a vanadium compound, an organoaluminum compound, and a halogenated ester compound, the method including a step of mixing and stirring the polymerization reaction mixture obtained by the polymerization reaction in an aqueous alkaline solution in such an amount as to give an aqueous phase having a pH of not lower than 10.0 after mixing and stirring, is disclosed. A method for …
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 December 12, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 12, 2013.
- 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.