Expired Canadian patentCanada
Preparation of quinacridonequinones and substituted derivatives of same
CA 2553531 C · Owner: Sung, Edward H. · Inventors: Sung, Edward H.; Dong, James Z.; Robertson, George H.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for oxidizing a quinacridone in a liquid medium with a non-metal oxidant to produce a quinacridonequinone.
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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 30, 2004 and granted March 26, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 30, 2024.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 30, 2004
GrantedMarch 26, 2013
Term endedDecember 30, 2024
Patent numberCA 2553531 C
Classification (IPC)C09B48/00
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.