Biscationic acid amide and imide derivatives and processes for their preparation
CA 2072597 C · Owner: Hoechst Aktiengesellschaft · Inventors: Gitzel, Jorg; Schiessler, Siegfried; Macholdt, Hans-Tobias
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to biscationic acid amide and acid imide derivatives with an anion of formula (I) where R9, to R12 are aliphatic, iso- or heterocyclic aromatic residues or aralkyl residues, which may be substituted by alkyl (C1-C4) residues, alkoxy (C1-C4) residues, aryl residues or halogen atoms, or are fluorine atoms, and mixtures of these compounds and mixed crystals with mixed anions and/or cations. The invention also relates to a process for preparing them. The new compounds are excellent colourless charge controllers in toners and developers for electrophotographic recording and as charge-enhancers in powders and paints for surface coating in, particular in triboelectrically or …
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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 17, 1990 and granted September 22, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 17, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 17, 2012.
- 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
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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.