Hindered amine light stabilizer hydrazides
CA 2044504 A1 · Owner: Myers, Terry N. · Inventors: Myers, Terry N.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
New and novel carboxylic acid hydrazides bearing a 2,2,6,6-tetra-alkyl-4-piperidine ring and new and novel polymeric compositions stabilized therewith are provided. The novel compounds which contain a light stabilizing group and a reactive hydrazide functionality in the same molecule are prepared by hydrazinolysis of the ester group of an intermediate carboxylic acid ester which contains the 2,2,6,6-tetralkylpiperidine moiety.
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
- Filed June 13, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 13, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 13, 2013.
- 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.