Polymerization of vinyl chloride
CA 2086685 A1 · Owner: Akira, Yamamoto · Inventors: Akira, Yamamoto; Keiichi, Fukuda; Yoshimatsu, Naka
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde the pH, of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being …
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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 December 28, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 28, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 28, 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.