4-carbamoyl derivatives of 1-oxa-3-oxo-4,8-diaza- spiro4,5decanes
CA 1111428 A · Owner: Hoechst Aktiengesellschaft · Inventors: Wiezer, Hartmut; Knorr, Harald; Pfahler, Gerhard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides novel 4-carbamoyl derivatives of 1-oxa-3-oxo-4,8-diaza-spiro-??4,5_7-decanes and their preparation from 1 oza-3-ozo-4,8-diaza-spiro-??4,5_7-decanes and isocyanates. The products are suitable light stabilizers for thermolpastics.
Read the whole patent
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 October 27, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 27, 1998.
- 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.