WATER-SOLUBLE DYE AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain a water-soluble dye having excellent shelf stability, dissolution stability and recording properties, by synthesizing a specified water-soluble bisazo dye and adjusting the concn. of nitrate radicals present in said dye to a specified range. CONSTITUTION:A water-soluble dye of formula I is synthesized and the concn. of nitrate radicals present in said dye is adjusted to a value of 0.0001-3wt%. In the formula, M is an alkali metal, ammonium or an amine. The compd. of formula I can be obtd. in the following manner. An amine of formula II is diazotized with sodium nitrite in a mineral acid and coupled with an amine of formula III. The resulting monoazo compd. of formula IV is diazotized and then coupled with 1-hydroxy-7-amino-naphthalene-3,6-disulfonic acid.