Process for producing styrene polymers
CA 2022155 C · Owner: Takeuchi, Mizutomo · Inventors: Takeuchi, Mizutomo; Teshima, Hideo; Kuramoto, Masahiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed a process for producing styrene polymer having a high degree of syndiotactic configuration which comprises polymerizing a styrene monomer in the presence of a catalyst comprising (A) aluminoxane and (B) a transition metal compound. The styrene monomer is a purified styrene monomer containing a phenylacetylene compound in an amount of 50 ppm or less. , According to the process a styrene polymer having a high, degree of syndiotactic configuration can be produced with good efficiency.
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 July 27, 1990 and granted February 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 27, 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.