Prepn. of powdery dye dispersions - using dispersant recondensate of phenol sulphonic acid, urea and formaldehyde condensate and phenol formaldehyde condensate

摘要

Highly conc. powdery dispersion- and vat dye compsns. contain, by wt., (a) 50-80 (60-70)% of >=1 finely dispersed dispersion- or vat dyes, and (b) 20-50 (30-40)% condensn. prod. as dispersant. Dispersant is prepd. by re-condensn. of (i) a condensate (I), which is prepd. by condensing phenolsulphonic acids, free from condensed ring systems, with urea and HCHO or HCHO-yielding matls., in mol. ratio 1:1-1.5:1.7-2.2, with (ii) a condensate (II) prepd. from phenol and HCHO, in mol. ratio 1:1, in a strongly alkaline medium. Re-condensn. takes place in a strongly acid medium. Before re-condensn. with (I), (II) is left to react 1-2 hrs. at pH 2-4. Compsns. dye textiles in pure colour shades, including bright yellow to orange. Condensate does not colour or soil textile fibres. Bright effects are obtd. when using optical brighteners. Even sensitive dyes can be dispersed at higher temps., e.g. 60-90 degrees C, to form stable dispersions. Dispersions can take place at pH 4-7 without increasing viscosity. Dispersion velocity achieved is higher than with standard dispersants. In an example, dispersant prepn. (I) was pred. from 94 pts. sulphonated phenol, 60 pts. urea and 190 pts. 30% HCHO. (II) was prepd. from 47 pts. phenol and 50 pts. 30% HCHO.