Process for producing liquid dyestuff preparations

摘要

Highly concentrated liquid preparations of disperse dyestuffs are obtained with a low consumption of energy by first adding a dispersing agent to the water-moist dyestuff press-cake to convert it into a form in which it is capable of flow, subjecting this product to wet grinding and increasing the dyestuff content of the resulting, insufficiently concentrated dispersion in a second step by means of a membrane separation process, for example pressure permeation.