Process for the production of propylene block copolymers
CA 1213686 A · Owner: Idemitsu Petrochemical Company Limited · Inventors: Kasahara, Toshikazu; Nishikawa, Tsutomu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing a propylene block copolymer by a three-step reaction in the presence of a stereoregular catalyst. At the first step, propylene is polymerized at a temperature of 55°C or more to form polypropylene having an intrinsic viscosity of from 0.5 to 3.5 in the prescribed amount. At the second step, propylene is polymerized at a temperature of from 30 to 90°C to form polypropylene having an intrinsic viscosity of at least 4 in the prescribed amount. And at the third step ethylene and propylene are copolymerized at a temperature of from 30 to 90°C to form an ethylenepropylene copolymer having an intrinsic viscosity of at least three in the prescribed amount. The propylene …
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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
- Granted November 4, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 4, 2003.
- 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.