摘要 |
PROBLEM TO BE SOLVED: To provide a stable alkaline p-phenylenediamine derivative generally usable for preparing various color developer formulations. SOLUTION: The concentrated aqueous solution of the p-phenylenediamine derivative having >pH 12.5 (a), containing 0.4-1.1 mol/l p-phenylenediamine derivative (b), 0.05-2 mol/l antioxidant (c), at most 35 wt.% organic solvent (d) with respect to the entire solution and at most 50 mmol/l sulfate ions (e) and having a single phase (f) is suitable for use in the preparation of various color developer formulations.
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