Process for the production of thermally color stable aliphatic and/or cycloaliphatic diisocyanates and the use thereof for the production of modified polyisocyanates having improved color properties
CA 1250854 A · Owner: Bayer Aktiengesellschaft · Inventors: Clarenz, Werner; Grave, Heinrich; Muller, Hanns P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for the production of aliphatic and/or cycloaliphatic diisocyanates which are color stable to heat which is, characterized in that a diisocyanate with aliphaticallyand/or cycloaliphatically-bound isocyanate groups is heated in the presence of about 0.1 to 3% by weight based on the diisocyanate, of at least one compound which is soluble in the diisocyanate and contains at least 3% by weight of structural units corresponding to the formula: , for up to about 5 hours at a temperature of about 100 to 220°C and the diisocyanate which has been treated in this way is subsequently purified by distillation. The present invention also relates to the use of …
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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 March 7, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 7, 2006.
- 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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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.