WATER-BASE INK AND PROCESS FOR PRODUCTION OF DYES

摘要

Aqueous ink for ink-jet recording contains >=1 naphthol sulfonate disazo dye or its salts as colorant and an aqueous solvent as main components. The dye is of formula (I): [Image] R1 and R3H, OH, or halogen; R2 and R4H, optionally substituted alkyl, optionally substituted aryl or optionally substituted aralkyl; A : phenyl or naphthyl optionally substituted by halogen, OH, amino, optionally substituted alkyl, alkoxy, carboxyl, carboxylate, sulfonamide, sulfonic acid and/or carboxylic acid amide groups; X : alkylene, phenylene, xylylene, naphthylene, biphenylene or a group (II), optionally substituted by halogen, alkyl, alkoxy, OH, amino, carboxyl or sulfonic acid group; Z : -CO-, -NHCONH-, -NHCSNH- or a group (III); m and n : 1-4. An independent claim is also included for the manufacture of the dye by dissolving a dye (I) or its salt in water and removing impurities by adjusting pH to >=9. [Image].