| 摘要 |
A very finely divided aqueous azo dye dispersion requiring no comminuting or dispersing aftertreatment whatsoever is obtained when an aqueous solution or dispersion of a diazotised amine is combined with an aqueous solution or suspension of a coupling component in the presence of a nonionic surfactant under coupling conditions. Then a membrane separation process such as reverse osmosis, ultrafiltration, dialysis or electrodialysis is employed to remove some of the water and some or all of the inorganic salts from the synthesis of the dye. The components of the dye are selected so as not to contain any water-solubilising groups. The dispersions obtained are suitable for colouring paints and printing inks.
|
