Process for the dyeing of fibre material

Claim 1

A batch process for dyeing fiber material comprising the steps of first applying to the fiber material a non-thickened aqueous dye liquor, consisting essentially of (a) a water-soluble or water-dispersible dyestuff having affinity for the fiber material (b) 0.2 to 10 g/l of a non-foaming anionic dispersing agent selected from the group consisting of benzene monosulfonic acid, naphthalene monosulfonic acid, C 1 -C 4 -alkyl benzene monosulfonic acid, C 1 -C 4 -alkyl naphthalene monosulfonic acid, tetrahydro naphthalene sulfonic acid, dinaphthylmethane disulfonic acid, diphenyl-naphthylmethane sulfonic acid, a 2:1 to 2:2 adduct thereof with formaldehyde, and water-soluble salts thereof, and (c) water, at a goods-to-liquor ratio of 1:1.5 to 1:2.5 and at a temperature below the absorption temperature of the dyestuff, subsequently in a closed container subjecting the fiber material and applied aqueous dye liquor to shaking or tumbling in a rotating drum sufficient to distribute evenly the aqueous dye liquor on the fiber material while still maintaining the temperature below the absorption temperature of the dyestuff, and finally heating the fiber material and the evenly distributed aqueous dye liquor to exhaust the dyestuff onto the fiber material.