| 摘要 |
PROBLEM TO BE SOLVED: To obtain a disazo dye compound having a specified structure and being useful to dye a cellulosic material, especially, paper. SOLUTION: This dye is one having a structure of formula I [wherein Ac is acetyl, propionyl, or benzoyl substituted with CH3, CH3O, or COOM; m, n, p, and q are each 0 or 1;; m+p=1; R is H or benzoyl substituted with CH3, CH3O, or COOM, and at least 25 equivalent % of all of the cations in the molecule are alkanolammonium groups of the formula: +NR1R2R3R4 (R1, R2, R3, and R4 are each H, a 1-4C alkyl, or a 2-4C hydroxyalkyl). The dye is produced by effecting the membrane filtration of an aqueous solution or suspension of a compound of formula I (M is +Na, +Li and/or +K) in the presence of an ammonium salt of the formula: +NR1R2R3R4An- (An- is an inorganic anion).
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