| 摘要 |
The invention relates to a process for the preparation of storage-stable dye dispersions of alkali metal salts of anionic azo direct dyes by (a) preparing an aqueous slurry of an alkali metal slat of an azo direct dye, said salt having a solubility in water at 25 degree C of about 0.1 to about 15 percent by weight, by azo coupling one or more aromatic diazonium salts with one or more couplers while maintaining a pH of at least about 5 by adding a basic alkali metal compound in the absence of a nitrogen-containing base; optionally, stirring the aqueous slurry at a temperature of about 5 degree C to about 100 degree C for up to about six hours; optionally, cooling the aqueous slurry to a temperature of about 5 degree C to about 40 degree C, and adding to the aqueous slurry a viscosity enhancing agent in an amount sufficient to obtain a viscosity of about 500 to about 5000 centipoise and 0 to about 10 percent by weight, based on the total weight of the dye dispersion, of a humectant.
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