The use of aromatic compounds as phase directors and particle size reducers for quinacridone pigments
CA 2442001 A1 · Owner: Ciba Specialty Chemicals Holding Inc. · Inventors: Jeganathan, Suruliappa Gowder; Ganci, James Barry; Hendi, Shivakumar Basalingappa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for producing alpha gamma-I, gamma-, II and gamma-III crystal modifications of quinacridone and transparent quinacridone pigments including the solid solutions of various quinacridones using a variety of tris-aryl-s-triazines particularly resorcinol triazine , derivatives or aromatic- or heteraromatic-compounds having at least one hydroxyl or keto group bonded to the ring as an additive, prior to or , concurrently with the oxidation of corresponding dihydroquinacridone salts.
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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 March 14, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 14, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 14, 2024.
- 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.