Abstract A level dyeing is obtained on fabric of synthetic polyamide fibers having a variable dyestuff affinity by treating the fabric at a temperature of from 70* to 130* C. in a liquor of which the pH value throughout is maintained between 3 and 5, said dye liquor containing an aqueous solution of a surface active compound containing sulphonic acid groups or a surface active sulphuric acid ester, e.g. a sulphated oil constituted by a high molecular weight fatty acid subjected to a high degree or an ester thereof, to which liquor there is then sequentially added, without cooling or going outside the stated pH value range, (i) a basic nitrogen containing compound, or a quaternized derivative thereof, which is an addition product of 20 to 200 mols of ethylene oxide to certain long chain non-cyclic amines defined hereinafter, and (ii), simultaneously or subsequently, an anionic dye which would normally dye said fabric giving a stripy appearance, e.g. a so-called milling acid dye, dyeing being then affected in the usual way.
A process according to claim 1, in which the pretreatment is effected with a solution of a sulphated castor oil of which the sulphation degree amounts to at least 70 percent.
Claim 2
Dependent Claim
30 words
A process according to claim 1, in which the pretreatment is effected with a solution of a sulphated oleic acid of which the sulphation amounts to at least 95 percent.
Claim 3
Dependent Claim
30 words
A process according to claim 1, in which said basic nitrogen containing compound is an addition product of 90 to 100 mols of ethylene oxide to 1 mol of C20-22-alkyl-3propylamine.
Claim 4
Dependent Claim
25 words
A process according to claim 1, in which the pretreatment and the adding of the dye are efFected at the boiling temperature of the liquor.
Claim 5
Dependent Claim
20 words
A process according to claim 1, in which the pretreatment is effected at a pH value of 4.5 to 5.
Claim 6
Dependent Claim
18 words
A process according to claim 1, in which dyeing is effected with at least one milling acid dye.