| abstract |
Sulphonated, sulphocarboxylated or polycarboxylated metallisable dyes are pasted with water and an anionic dispersant, the pH of the paste being such that the dye is practically in the undissolved state at room temperature and the dye particles have a size not greater than 5 microns. The pastes may then be dried, e.g. spray dried, to form a dry powder. The pastes and powders so obtained may be employed to dye animal or superpolyamide fibres by known after-chroming or simultaneous chroming (monochrome or metachrome) processes even with very hard water using a bath-circulating apparatus. In the examples the following aniomic dispersants are employed: (1) dinaphthylmethane disulphonate together with sodium diheptyl sulphosuccinate, (3) as in (1) plus sodium sulphoricinoleate, (4) sodium lignin sulphonate and sulphated lauryl alcohol, (5) as in (1) plus diheptyl sulphosuccinate. Specifications 976,417 and 1,001,181 are referred to. |