Process for the preparation of diepoxides
CA 1062719 A · Owner: Societa' Italiana Resine S.I.R. S.P.A. · Inventors: Vargiu, Silvio; Grazzini, Giulio; Crespolini, Giancarlo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Diepoxides of the general formula: wherein n has an average value not exceeding 0.03 and R is the bisphenyl radical of bisphenol-A are recovered from an epoxy resin of the same general formula with n varying from 0.07 to 0.30, by removing the low-boiling substance from the epoxy resin at 0.1 - 1 mm Hg and 165° - 200°C and distilling off said diepoxide from the thus treated epoxy resin at 0.1 - 0.005 mm Hg and a temperature not exceeding 240°C. The low viscosity narrow, moleoular weight distribution and excellent purity of these diepoxides allow their use in critical application fields.
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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
- Granted September 18, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 18, 1996.
- 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.