Method for preparing polybutadiene endowed with improved processability characteristics
CA 2010284 C · Owner: Bianchi, Renzo (Deceased) · Inventors: Bianchi, Renzo (Deceased); Andreussi, Piero; Bruzzone, Mario
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The processability of a polybutadiene with a high content of 1,4-cis-structure is improved by means of the addition of PCl3 before the polymerization reaction is quenched and when Mooney viscosity of polybutadiene has reached a prefixed value, preferably lower than or equal, to 30; the polymerization of butadiene is carried out in a solution in an aliphatic or cycloaliphatic solvent in, the presence of a catalytic system based an rare earths preferably a neodymium-based catalytic system.
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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 February 16, 1990 and granted May 16, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 16, 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.