Dyeing of polyamide fibers with anionic dyes using a cationic assistant followed by an anionic assistant
AssigneeSandoz Ltd.
InventorsJosef Frauenknecht, Dieter Schwer
Life of this patent
Estimating the term…
Abstract
The invention relates to a process for dyeing synthetic or natural polyamide fibers with anionic dyestuffs, comprising (i) bringing the polyamide fibers into contact with an aqueous dyeing liquor which contains in addition to one or more dyestuffs a cationic dyeing assistant having affinity for anionic polyamide dyestuffs, and dyeing the polyamide fibers at a temperature of from 60.degree. to 105.degree. C., and (ii) adding an anionic dyeing assistant to the dyeing liquor 15 to 60 minutes after reaching the dyeing temperature, to complete the dye exhaustion. Surface and fibre level dyeings with a good dye penetration are thus obtained.
Claims40
A process for dyeing a textile substrate comprising synthetic or natural polyamide fibres with anionic dyestuffs, comprising the steps of (i) bringing the polyamide fibres into contact with an aqueous dyeing liquor which contains, in addition to one or more anionic dyestuffs, a cationic dyeing assistant which is capable of forming an addition product with the anionic dyestuff and which has a retarding action on the anionic dyestuff, and dyeing the polyamides fibres in said dyeing liquor at a temperature of from 60.degree. to 105.degree. C., and (ii) adding an anionic dyeing assistant to the dyeing liquor 15 to 60 minutes after reaching the dyeing temperature and continuing the dyeing to complete the dye exhaustion, said cationic dyeing assistant being selected from the group consisting of compounds of formula I ##STR5## in which R is C.sub.12-30 alkyl or alkenyl
- X is a direct bond or --CO--
- Y is C.sub.2 or C.sub.3 alkylene
- each of A.sub.1, A.sub.2 and A.sub.3 is independently selected from the class consisting of polyethylene oxide chains and poly(ethylene oxide/C.sub.3 or C.sub.4 alkylene oxide) chains, the total sum of the ethylene oxide units in all three chains being from 3 to 200 and the total sum of the C.sub.3 or C.sub.4 alkylene oxide units in all three chains being up to 100, and
- m is 0 or an integer from 1 to 6,
- which compounds may also contain up to a total of 5 styrene-oxy groups distributed through the chain A.sub.1 and/or A.sub.2 and/or A.sub.3
- and their quanternization products;
- and compounds of formula II ##STR6## in which R.sub.1 is C.sub.12-24 alkyl or alkenyl
- X.sub.1 is the anion of a polybasic acid,
- r and s represent whole numbers the sum of which is 10 to 100,
- q is 2, 3 or 4, and
- p is 1 or 2,
- and their protonation and quaternizaiton products.
A process for dyeing a textile substrate comprising synthetic or natural polyamide fibres with anionic dyestuffs, comprising the steps of (i) bringing the polyamide fibres into contact with an aqueous dyeing liquor which contains, in addition to one or more anionic dyestuffs, a cationic dyeing assistant which is capable of forming an addition product with the anionic dyestuff and which has a retarding action on the anionic dyestuff, and dyeing the polyamide fibres in said dyeing liquor at a temperature of from 60.degree. to 105.degree. C., and (ii) adding an anionic dyeing assistant to the dyeing liquor 15 to 60 minutes after reaching the dyeing temperature and continuing the dyeing to complete the dye exhaustion, said cationic dyeing assistant being an addition product of a fatty amine, fatty polyamine, fatty acid amide-amine or fatty acid amide-polyamine, in which the fatty residue is saturated or unsaturated, with (1) ethylene oxide or with (2) ethylene oxide and a C.sub.3 and C.sub.4 alkylene oxide or with (1) or (2) and styrene oxide, which product contains up to 200 ethyleneoxy groups and up to 100 C.sub.3 or C.sub.4 alkyleneoxy groups and up to 5 styreneoxy groups.
Dependencies are inferred from the claim text.