Process for preparing a polymer using lithium initiator prepared by in situ preparation
CA 2108594 C · Owner: Morita, Koichi · Inventors: Ozawa, Yoichi; Nakayama, Atsushi; Fujio, Ryota
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing a polymer comprises polymerizing a conjugated dime monomer and/or a vinylaromatic hydrocarbon monomer in a hydrocarbon solvent in the presence of or in the absence of a randomizer by using a lithium polymerization initiator which is formed by bringing an organolithium compound and at least one secondary amine compound into contact with each other in the polymerization system in the presence of at least said monomer. The secondary amine is an amine compound having two hydrocarbon groups bonded to N or an imine compound in which an NH group and a saturated or unsaturated cyclic structure group form a cyclic structure. The cyclic structure group comprises a hydrocarbon …
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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 October 18, 1993 and granted October 17, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 18, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 18, 2015.
- 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
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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.