Fine particle application of dyes or optical brightener to leathers or fabrics in a tumbling drum at low volumes in a hydrophobic solvent

Abstract

An improved process for the dyeing of organic material, especially synthetic organic material, from organic solvents with application of a short goods-to-liquor ratio, by (a) applying a concentrated organic dye liquor heated to at least 80.degree. C with a goods-to-liquor ratio of 1:1.5 to 1:4 in atomized form to said organic material maintained in motion in an essentially closed chamber, preferably at a temperature below the absorption temperature of the dyestuffs, said concentrated organic dye liquor containing at least one dyestuff or optical brightener dissolved and/or finely dispersed in an organic solvent and having affinity to the fibers of the substrate to be dyed; (b) heating the thus treated organic material after application of the whole amount of the dye liquor to a temperature of 100.degree. to 150.degree. C; (c) finishing the dyeing by keeping the treated organic material at this temperature in an advantageously saturated organic solvent vapor atmosphere until complete fixation of the dyestuff is obtained; (d) optionally subsequently finishing and/or washing the dyed organic material after extensive removal of the residual liquor, by applying an organic solution, suspension and/or organic solvent in atomized form at a goods-to-liquor ratio of 1:1.5 to 1:4, and (e) drying the dyed organic material.

Dependencies are inferred from the claim text.