Suspension polymerization of vinyl chloride
CA 2065564 A1 · Owner: Shin-Etsu Chemical Co. Ltd. · Inventors: Amano, Tadashi; Koga, Toshimichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved method is proposed for the suspension polymerization of vinyl chloride monomer in an aqueous medium by which, the polyvinyl chloride resin obtained may have an increased bulk density without causing any disadvantages. The improvement can be obtained by controlling the power on the stirrer for the agitation of the polymerization mixture in such a manner that the power at the moment of the start of the polymerization reaction is 100 to 200 kgf?m/s per 1000 kg of the polymerization mixture and the power is subsequently decreased to 60% to 90% of the value at the start of the polymerization reaction until the moment when conversion of the monomer to polymer does not exceed 30%.
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 April 8, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 8, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 8, 2014.
- 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.