Method for recovering unreacted monomers after preparation of vinylic polymer
CA 2065486 A1 · Owner: Shigemitsu, Minoru · Inventors: Amano, Tadashi; Shigemitsu, Minoru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for recovering unreacted monomers during preparation of a vinylic polymer comprises the steps of polymerizing a vinyl monomer in an aqueous medium in a polymerizer and then recovering unreacted monomers from the polymerization system wherein a gas, evacuation rate per unit charge weight of the monomer is controlled to the range of from 60 to 300 Nm3/hr per ton of the monomer from the initiation of the monomer recovery till the pressure in the polymerizer reaches 2.5 kg/cm2G and a superficial gas linear velocity is reduced to a level of not more than 0.008 m/sec when the pressure in the polymerizer reaches 2.5 kg/cm2G. The method makes it possible to recover unreacted monomers …
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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 April 7, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 2014.
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Timeline
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.