Process for the preparation of copolymers of conjugated dienes and vinyl aromatic compounds
CA 2023218 C · Owner: Plum, Johannes Theodorus Andreas · Inventors: Plum, Johannes Theodorus Andreas; Van Ballegooijen, Hendrik; Peters, Joseph Peter Marie
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the preparation of random copolymers or block copolymers of at least one conjugated diene and at least one vinyl aromatic compound comprising reacting the monomers with the aid of an initiator based on lithium in the presence of an essentially inert solvent wherein said solvent consists for at least 60 per cent by weight of cyclopentane and the heat of reaction is withdrawn by means of reflux cooling.
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 August 14, 1990 and granted February 20, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 14, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 14, 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.