Preparation process for manufacture and purification of mixtures of fluoran compounds and recording material comprising said mixtures of fluoran compounds
US6635602B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2001 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Feb 26, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M5/3275
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A process for the manufacture of mixtures of fluoran compounds by the reaction of keto acids of formula (II) with a compound of formula (III) in the presence of a dehydrating condensation agent, wherein R1 and R2 independently represent hydrogen; an alkyl of 1-18 carbon, a secondary alkyl with respect to the carbon atom bonded to the nitrogen atom of 3-13 carbon atoms, a cycloalkyl of 4-8 carbon atoms or a phenyl, both of which may be substituted by at least one substituted selected from the group consisting of halogen atoms and alkyls having 1-4 carbon atoms, an aralkyl of 7-10 carbon atoms; or R1 and R2, together with the adjacent nitrogen atom from a heterocyclic ring; R3 is hydrogen, an alkyl of 1-4 carbon atoms, an alkoxy of 1-4 carbon atoms, a phenyl; a substituted phenyl or a halogen; R4 is an alkyl group of 1-18 carbon atoms, a carboxyalkyl of 1-18 carbon atoms, a carboxycycloalkyl of 4-8 carbon atoms, an alkylamino of 1-18 carbon atoms, a cycloalkylamino of 4-8 carbon atoms, a dialkylamino or dicycloalkylamino; an arylamino, a substituted arylamino; an aralkylamino of 7-10 carbon atoms; a diaralkylamino; R5 is an alkyl of 1-18 carbon atoms, a carboxy alkyl of 1-18 carbon a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.