Process for the production of diisocyanates, selected diisocyanates produced thereby and the production of polyurethane plastics therefrom
CA 1292006 C · Owner: Bayer Aktiengesellschaft · Inventors: Sanders, Josef
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Diisocyanates corresponding to a specified formula are produced by reacting an alcohol corresponding to a specified formula with a nitrochlorobenzene in the presence of NaOH and/or KOH in powder form and a strongly polar, aprotic solvent to produce a dinitro compound corresponding to a specified formula. This dinitro compound is hydrogenated to form the corresponding diamine which diamine is phosgenated to produce the corresponding diisocyanate. The resultant diisocyanates may then be used as starting materials in polyisocyanate addition processes.
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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 November 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 12, 2008.
- 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.