Process for the preparation of compounds containing hydroxyl groups and their use in the production of polyurethane resins
CA 2084922 C · Owner: Rasshofer, Werner · Inventors: Liman, Ulrich; Rasshofer, Werner; Muenzmay, Thomas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Compounds containing alcoholic hydroxyl groups suitable as a starting material for the isocyanate polyaddition process by the alcoholysis of polyisocyanate polyaddition products are produced. Polyurethane urea or polyurea waste products having a molar ratio of urea groups to urethane groups of from 1:20 to 1:0 are heated in size reduced form to temperatures of from 120 to 250°C together with B) polyhyhdric alcohols in the molecular weight range of from 62 to 250 in a ratio by weight of A:B of from 3:1 to 1:10. At least 10% of the polyhydric alcohol B put into the process is subsequently removed by distillation under reduced pressure. A total of up to 1000% by weight based on, the weight 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
- Filed December 9, 1992 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 9, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 9, 2014.
- 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.