Synthesis of 1,4-trans-polybutadiene using a lanthanide organic acid salt catalyst
CA 2247669 A1 · Owner: Bridgestone Corporation · Inventors: Lynch, Thomas J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides a catalyst composition comprising: (a) an organolithium compound; and, (b) an organic acid salt of lanthanide series element; wherein: (1) only components (a) and (b) are required to promote the synthesis of 1,4-trans-polybutadiene; (2) the ratio of component (a) to component (b) is selected to maximize formation of the trans structure of said 1,4-trans-polybutadiene; and, (3) components (a) and (b) are selected for enabling further diblock synthesis. The invention further contemplates a process for using the catalyst to synthesize 1,4-trans-polybutadiene and other polymers and copolymers having trans configuration in the conjugated diene monomer contributed units.
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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 September 17, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 17, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 17, 2020.
- 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.