Process control in the presence of chromium based catalysts
CA 2232207 C · Owner: Lee, Kiu H. · Inventors: Lee, Kiu H.; Samples, Paul K.; Parrish, John R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A continuous process for the polymerization of one or more alpha-olefins in the gas phase in the presence of a chromium based catalyst, under polymerization conditions including the reaction temperature, the pressure, and the target oxygen to alpha-olefin molar ratio operating point required for desired resin properties comprising, the following steps:, (i) establishing limits on (a) the amount of catalyst and (b) the oxygen to alpha-olefin molar ratio; (ii) establishing a desired resin production rate in pounds per hour;, (iii) determining the actual production rate as the polymerization progresses;, (iv) determining the amount of catalyst required (a) to bring the actual production rate …
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 March 16, 1998 and granted January 1, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 16, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 16, 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
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.