Process for making a non-aqueous dispersion of a copper phthalocyanine
CA 2179749 C · Owner: Zeneca Limited · Inventors: Schofield, John David; Thetford, Dean
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of preparing a non-aqueous dispersion of copper phthalocyanine (CuPc) which comprises milling crude CuPc in a high boiling liquid at a temperature from 50 to 150°C in the presence of a polyester amine or polyesterammonium salt and a CuPc fluidising agent. Preferred polyesterammonium salt is obtainable by reacting polyhydroxystearic acid with 3-dimethylaminopropylamine quaternised with dimethylsulphate.
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 December 20, 1994 and granted August 28, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 2016.
- 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.