Corrosion-resistant material for sulfur-containing alkali metal salts and equipment for producing polyarylene sulfide using the same, and polyarylene sulfide and process for producing the same
CA 2039916 A1 · Owner: Tosoh Corporation · Inventors: Inoue, Hiroshi; Kato, Masatoshi; Kato, Toshikazu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A corrosion-resistant material against sulfur-containing alkali metal salt which comprises high purity metallic chromium having a relative density of 95% or higher and a purity of 99.7% or higher and equipment for production of polyarylene sulfides which is composed of such a corrosion-resistant material, and a polyarylene sulfide containing substantially no heavy metal and a process for producing such a polyarylene sulfide comprising reacting an alkali metal sulfide and a dihalogenated aromatic compound in a polar aprotic solvent by using equipment made of high purity chromium having a purity of 99.7% or higher and having a relative density of 95% or higher at least at parts in contact …
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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 5, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 5, 2013.
- 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
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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.