Process for the dyeing of fibre material

An improved process for dyeing of fibre material, especially textile fibres, by applying to the fibre material at a temperature below the absorption temperature of the dyestuffs and with a goods-to-liquor ratio of 1:1.5 to 1:4, a concentrated aqueous dye liquor, said concentrated aqueous dye liquor containing at least one dyestuff which, in the case of the substrate to be dyed, has affinity to the fibres and which is either soluble or dispersible in water and 0.2 to 10 g/l, preferably 2 to 5 g/l, of at least one nonionic, surface-active agent from the class of ethylene oxide addition products and having a cloud point below 85.degree. C., and finishing of the dyeing by means of a heat treatment, e.g. introduction of saturated steam, superheated steam or hot air, preferably by heating from without, at temperatures of 95.degree. to 140.degree. C.

The present invention relates to a process for the dyeing of fibre material 
in concentrated dye liquors with water-soluble or water-dispersible 
dyestuffs, as well as to the fibre material dyed by the new process. 
Processes are known which consist of the continuous dyeing of voluminous 
textile webs in concentrated dye liquors by the feeding of the webs 
through a trough filled with dye liquor, or by the impregnation of the 
said material by means of an overflow, with dye liquor absorptions of ca. 
250 to 300% being obtained; and subsequently the fixing of the dyestuff 
by, for example, steaming with saturated steam. These processes are 
limited, however, to the dyeing of voluminous webs, particularly carpets. 
Moreover, the process has already been suggested wherein fibre material is 
dyed in concentrated dye liquors containing the dyestuff and at least one 
foam-forming compound, dyeing being effected by means of a stable 
microfoam. For example, the material to be dyed is sprayed with dye liquor 
and fed into a drum dyeing machine, whereupon an intense foam is produced 
by a tumbling action, the dyestuff being then fixed by a heat treatment 
consisting, for example, of the introduction of saturated steam or hot 
air. But this process too has disadvantages, one particular disadvantage 
being that relatively large amounts of foam-forming compounds are 
required, with the removal of these from the dyed material necessitating 
the application of several washing operations. Furthermore, dyeing in the 
presence of a stable microfoam can be performed only in a quite specific 
type of equipment. 
A process has now been found which renders possible, in a simple manner and 
with avoidance of the mentioned difficulties and disadvantages, the 
obtainment on diverse fibre materials, preferably textile fibres, of 
excellent dyeings is concentrated dye liquors. This process comprises the 
application to the fibre material of an aqueous dye liquor at a 
temperature below the absorption temperature of the dyestuffs and with a 
goods to liquor ratio of 1:1.5 to 1:4, the said aqueous dye liquor 
containing at least one dyestuff which, in the case of the substrate to be 
dyed, has affinity to the fibres, and which is either soluble or 
dispersible in water, and 0.2 to 10 g/l, preferably 2 to 5 g/l, of at 
least one nonionic, surface-active agent from the class of ethylene oxide 
addition products and having a cloud point below 85.degree. C., and the 
finishing of the dyeing by means of a heat treatment. 
Suitable water-soluble dyestuffs having affinity to fibres or 
water-dispersible dyestuffs, applicable according to the invention, are 
the same organic dyestuffs as are normally used in textile dyeing for the 
dyeing of fibre materials, particularly textile fibres, from an aqueous 
dye liquor. Depending on the substrate to be dyed, suitable dyestuffs are 
water-soluble anionic or cationic dyestuffs, or dispersion dyestuffs. 
The dyestuffs usable according to the invention can belong to the most 
diverse classes of dyestuffs. These are, in particular, mono-, dis- or 
polyazo dyestuffs, formazan, anthraquinone, nitro, methine, styryl, 
azastyryl or phthalocyanine dyestuffs. 
With regard to the water-soluble anionic dyestuffs these are, in 
particular, the alkali metal salts or ammonium salts of the dyestuffs 
known as acid wool dyestuffs, of the reactive dyestuffs, or of the 
substantive cotton dyestuffs of the azo, anthraquinone and phthalocyanine 
series. Suitable azo dyestuffs are preferably metal-free mono- and disazo 
dyestuffs containing one or more sulphonic acid groups, 
heavy-metal-containing, particularly copper-, chromium-, nickel- or 
cobalt-containing, monoazo, disazo and formazan dyestuffs, and metallised 
dyestuffs containing bound to one metal atom 2 molecules of azo dyestuff. 
Anthraquinone dyestuffs to be given particular mention are 
1-amino-4-arylamino-anthraquinone-2-sulphonic acids, and in the case of 
phthalocyanine dyestuffs, particularly sulphated copper phthalocyanines or 
phthalocyaninearylamides. 
As reactive dyestuffs containing sulpho groups mention may be made of 
water-soluble dyestuffs of the azo, anthraquinone and phthalocyanine 
series containing at least one fibre-reactive group, e.g. a 
monochlorotriazinyl, dichlorotriazinyl, dichloroquinoxalinyl, 
trichloropyrimidinyl, difluorochloropyrimidinyl, .alpha.bromoacrylamide 
group or the .beta.-oxyethylsulphuric acid ester group. 
In the case of the water-soluble cationic dyestuffs, these are the usual 
salts and metal halide double salts, e.g. zinc chloride double salts, of 
the known cationic dyestuffs, especially the methine, azomethine, or azo 
dyestuffs which contain the indolinium, pyrazolium, imidazolium, 
triazolium, tetrazolium, oxdiazolium, thiodiazolium, oxazolium, 
thiazolium, pyridinium, pyrimidinium or pyrazinium ring. Also suitable are 
cationic dyestuffs of the diphenylmethane, triphenylmethane, oxazine and 
thiazine series, and, finally, also dye salts of the arylazo and 
anthraquinone series with an external onium group, e.g. an external 
cyclammonium group or alkylammonium group. 
Concerning the dispersion dyestuffs, these are especially azo dyestuffs, as 
well as anthraquinone, nitro, methine, styryl, azostyryl, naphthoperinone, 
quinophthalone or naphthoquinoneimine dyestuffs. These difficultly 
water-soluble dyestuffs form in the finely-ground condition, with the aid 
of dispersing agents, very fine aqueous suspensions. 
The process according to the invention is suitable also for the optical 
brightening of undyed textile materials with dispersion brighteners, and 
particularly with water-soluble anionic and cationic optical brighteners. 
These can belong to any desired classes of brighteners. They are, in 
particular, stilbene compounds, coumarins, benzocoumarins, pyrazines, 
pyrazolines, oxaxenes, dibenzoxazolyl or dibenzimidazolyl compounds, as 
well as naphthalic acid imides. 
The amounts in which the dyestuffs are used in the dye baths can vary, 
depending on the desired depth of colour, within wide limits; in general, 
amounts of 0.001 to 10 percent by weight, relative to the material to be 
dyed, of one or more dyestuffs have proved advantageous. 
The cationic dyestuffs are employed, for example, for the dyeing of fibre 
materials made from polyacrylonitrile, modified synthetic polyesters or 
polyamides, cellulose-21/2-acetate, cellulose triacetate and silk; the 
anionic acid dyestuffs, metal-complex dyestuffs, substantive and reactive 
dyestuffs for the dyeing of fibre materials made from natural or 
regenerated cellulose, such as cotton, spun rayon and Rayon, natural 
polyamides such as wool and silk, synthetic polyamides such as 
polyhexamethylene-diaminoadipate, poly-.epsilon.-caprolactam or 
poly-.omega.-aminoundecanoic acid, and polyurethanes; and the dispersion 
dyestuffs for the dyeing of fibre materials made from synthetic polyesters 
such as polyethylene glycol terephthalate, 
polycyclohexanedimethyleneterephthalate, cellulose triacetate, 
polyacrylonitrile, synthetic polyamides, polyurethanes and polyolefins. 
The process according to the invention has proved particularly satisfactory 
for the dyeing of mixtures of these fibre types with a mixture of the 
dyestuffs suitable for the substrates to be dyed; for example, mixtures of 
polyacrylonitrile/spun rayon, polyester/cotton, polyester/spun rayon, 
polyamide/spun rayon, polyamide/cotton, cellulose-21/2-acetate/spun rayon, 
cellulosetriacetate/spun rayon, polyacrylonitrile/polyester, and 
especially polyester/wool. 
The fibre materials can be in the most diverse stages of processing; e.g., 
they may be in the form of fabrics, knitwear, yarns, ready-made articles, 
knitted goods, fibre fleece materials, textile floor coverings such as 
woven, tufted or felted carpets. 
Nonionic surface-active agents from the class of ethylene oxide addition 
products and having a cloud point below 85.degree. C. usable according to 
the invention are particularly addition products of 4 to 10 mols ethylene 
oxide with 1 mol of fatty alcohol, fatty acid or fatty amine having 8 to 
18 carbon atoms or with 1 mol of alkylphenols having a straight or 
branched chain alkyl radical containing 7 to 12 carbon atoms. Preferred 
because they produce particularly good colour yields are addition products 
of 6 to 10 mols of ethylene oxide with decyl-, undecyl- or dodecyl-alcohol 
or with octyl- or nonyl-phenol, such as lauryloctaethylene glycol ether, 
dodecylhexaethylene glycol ether and especially nonylphenoldecaethylene 
glycol ether or octylphenolheptaethyleno glycol ether. 
The cloud point of the aqueous solution of a defined nonionic surfactant is 
a characteristic property. The cloud point is defined as the temperature 
above which the aqueous solution of an ethylene oxide addition product 
occurs as a mixture of two liquid phases. The greater the member of 
ethylene oxide molecules which have been added to the basic molecule, the 
higher the temperature at which turbidity sets in and then disappears 
again when the temperature of the solution drops below a certain value. 
The cloud point is, however, also dependent upon the concentration of the 
solution. It is therefore necessary to use a constant concentration, e.g. 
a 0.1 to 0.5 percent aqueous solution. This is determined by slowly 
cooling the solution and measuring the temperature at which the mixture 
again becomes homogeneous. This temperature, which may also be called the 
"clear point", must not necessarily be identical with the temperature at 
which turbidity set in. However, because of measuring techniques, the 
temperature of the "clear point" is determined and this value is 
conventionally called the cloud point (Fachnormenansschuss Materialprufung 
in Deutachen Normensusschuss--October, 1967). 
If necessary, the dyestuff liquor can contain further components such as 
acids, especially an organic, lower aliphatic monocarboxylic acid, e.g. 
formic or acetic acid; sodium hydroxide; salts such as ammonium sulphate, 
sodium sulphate, sodium carbonate or sodium acetate; and/or carriers, e.g. 
based on o-phenylphenol, trichlorobenzene or diphenyl. 
For the preparation of dye liquors, it is advantageous to commence with 
aqueous dyestuff solutions or dyestuff dispersions, and to then add to 
these the suitable nonionic, surface-active agents defined. 
The process according to the invention is preferably performed in closed, 
optionally pressure-tight containers, e.g. in circulation equipment such 
as cheese dyeing machines or beam dyeing machines, jet machines, winch 
dyeing machines, drum dyeing machines, open vats, or inpaddle- or 
jig-dyeing machines. The process can be carried out, for example, as 
follows: The dye liquor and the material to be dyed are transferred, with 
a goods to liquor ratio of 1:1.5 to 1:4, preferably 1:1.5 to 1:2.5, or the 
material impregnated with the given goods to liquor ratio or 
advantageously sprayed, at a temperature below the absorption temperature 
of the dyestuffs, advantageously at 20.degree. to 40.degree. C., to the 
container; the dye liquor is then evenly distributed on the fibre 
material, below the absorption temperature of the dyestuffs, optionally by 
mechanical movement; and the temperature of the dye bath subsequently 
raised, by the introduction of saturated steam, superheated steam or hot 
air, advantageously however by heating from without, within 15 to 30 
minutes to 95.degree. to 140.degree. C., advantageously to 98.degree. to 
105.degree. C.; and this temperature maintained for ca. 15 to 120 minutes, 
advantageously for 20 to 45 minutes, until the dye liquor is exhausted. 
The dye bath is then cooled and the dyed material removed from the bath; 
the bulk of surplus dye liquor is separated from the material by 
squeezing, and the dyed fibre material, optionally after rinsing with warm 
water, dried. By virtue of the high degree of bath exhaustion and the 
small amounts of the nonionic, surface-active agents defined, a subsequent 
cleansing of the dyed material is in most cases unnecessary. 
Compared with known processes, the process according to the invention has 
noticeable advantages. The main advantages are that the dyestuffs are 
practically completely absorbed, that only little or no migration of the 
dyestuffs occurs, and that, within shorter dyeing times than usual, deeply 
coloured, even and non-streaky dyeings well dyed throughout are obtained. 
According to the present invention, deeply coloured dyeings are obtained 
with extremely small amounts of water, and hence with practically no 
accumulation of contaminated water, and without dyeing being performed in 
the presence of a stable microfoam, the obtained dyeings being to a great 
extent free from sandwich effects. 
The following examples serve to illustrate the invention. Temperatures are 
expressed in degrees Centigrade.

EXAMPLE 1 
An amount of 0.9 g of the dyestuff of the formula 
##STR1## 
(See C.I. No. 23635) is dissolved in 90 ml of hot water; additions are 
then made to the solution of 0.5 g of nonylphenolecaethylene glycol ether 
and 0.2 ml of acetic acid (40%), and the whole made up by the addition of 
water to 100 ml. After cooling to room temperature, the dyestuff solution 
is transferred together with 66 g of polyamide-6.6-tricot in the rolled-up 
state, to a metal container such as is employed for the dye baths of the 
equipment of the firm Callebaut de Blicouy, Brussels; the container is 
thereupon sealed and thoroughly shaken. The container is then maintained 
in continuous movement in the dyeing apparatus in the usual manner; the 
bath temperature is raised within 15 minutes from 20.degree. to 
100.degree., and then held at this temperature for 30 minutes. After 
cooling, the dyed fabric is removed, and then squeezed out to leave as 
little moisture as possible in the material; it is subsequently rinsed by 
heating with water, with a goods to liquor ratio of 1:2, in the above 
described container for 5 minutes, and finally dried. 
An even, non-streaky, brilliant red dyeing is obtained which is excellently 
dyed throughout, and which has very good fastness to wet processing and to 
light. 
EXAMPLE 2 
If, instead of the dyestuff given in Example 1, 1.5 g of the 1:2-chromium 
complex of the dyestuff of the formula 
##STR2## 
(See C.I. No. 18165) is used, and instead of 66.6 g of 
polyamide-6.6-tricot 66.6 g of wool flannel, the procedure being otherwise 
as described in Example 1, then a dark-grey even wool dyeing is obtained 
well dyed throughout and possessing good fastness to wet processing and to 
light. The small amount of dye liquor remaining after dyeing is 
colourless. 
If, instead of 0.5 g of nonylphenoldecaethylene glycol ether in the above 
example, 0.5 g of octylphenolheptaethylene glycol ether or 0.5 g of 
lauryloctaethylene glycol ether is added, the procedure being otherwise 
the same as described in Example 2, then there are likewise obtained even 
dark-grey wool dyeings well dyed throughout. 
If, instead of the above dyestuff of this Example, 0.6 g of the dyestuff of 
the formula 
##STR3## 
or 0.6 g of the dyestuff of the formula 
##STR4## 
(See U.S. Pat. No. 3,448,343) is used, the procedure being otherwise as 
described in this Example, then there is obtained a red wool dyeing well 
dyed throughout and possessing fastness to light and to wet processing. 
EXAMPLE 3 
An amount of 1.3 g of the dyestuff of the formula 
##STR5## 
(See U.S. Pat. No. 2,982,764) is dissolved in 90 ml of hot water; 
additions are then made to the solution of 0.5 g of 
nonylphenoldecaethylene glycol ether and 0.5 g of sodium sulphate, and the 
liquor made up to 100 ml by the addition of water. The dyestuff solution 
is cooled to room temperature and transferred, together with 66.6 g of 
cotton fabric in the rolled-up state, to a metal container; the container 
is sealed and well shaken. 
With otherwise the procedure as given in Example 1, there is obtained an 
evenly dyed dark-grey cotton fabric, which is well dyed throughout and 
possesses good fastness to wet processing and to light. 
EXAMPLE 4 
If, instead of the dyestuff given in Example 1, 0.01 g of the optical 
brightener of the formula 
##STR6## 
(See U.S. Pat. No. 2,889,315) is used, the procedure being otherwise as 
described in Example 3, then there is obtained an even optically 
brightened cotton fabric. 
EXAMPLE 5 
An amount of 0.66 g of the dyestuff of the formula 
##STR7## 
is dissolved in 90 ml of hot water. Additions are made to the obtained 
solution of 0.5 g of nonylphenol decaethylene glycol ether and 0.2 ml of 
acetic acid (80%); and the solution is then made up by the addition of 
water to 100 ml. After cooling to room temperature, the dyestuff solution 
is transferred, together with 66.6 g of a polyacrylonitrile staple fabric 
(ORLON) in the rolled-up state, to a metal container such as is employed 
for the dye baths of the equipment of the firm Callebaut de Blicquy, 
Brussels; the container is thereupon scaled and thoroughly shaken. The 
container is then maintained in continuous movement in the dyeing 
apparatus in the usual manner; the bath temperature is raised within 15 
minutes from 20.degree. to 100.degree., and then held at this temperature 
for 30 minutes. After cooling, the dyed fabric is removed, and then 
squeezed out to leave as little moisture as possible in the material; it 
is subsequently rinsed by heating with water, with a goods to liquor ratio 
of 1:2, in the above described container for 5 minutes, and finally dried. 
An even blue dyeing is obtained which is excellently dyed throughout, and 
which has very good fastness to wet processing and to light. 
EXAMPLE 6 
An amount of 0.66 g of the dyestuff of the formula 
##STR8## 
(See U.S. Pat. No. 3,558,261) is dispersed in 50 ml of hot water; 
additions are then made to the dispersion of 0.5 g of nonylphenol 
decaethylene glycol ether, and 0.6 g of carrier consisting of 45 parts of 
o-phenylphenol, 41 parts of ethylene glycol, 2.5 parts of polyvinyl 
alcohol, 2.5 parts of dioctylsulphosuccinate and 9 parts of water, 
dissolved in 50 ml of hot water. After cooling to room temperature, the 
dyestuff suspension is transferred, together with 33 g of polyethylene 
glycol terephthalate fabric, to a metal container such as is described in 
Example 1. If the procedure given in Example 1 is then carried out, an 
even orange dyeing well dyed throughout is obtained, which possesses the 
same fastness to wet processing and to light as a corresponding dyeing on 
polyethylene glycol terephthalate fabric obtained in the usual manner with 
a goods to liquor ratio of 1:10. 
EXAMPLE 7 
An amount of 0.66 g of the dyestuff mixture consisting of 10 parts of the 
dyestuff of the formula 
##STR9## 
and 60 parts of the dyestuff of the formula 
##STR10## 
is dissolved in 90 ml of hot water; additions are then made to the 
dispersion of 0.5 g of octylphenolheptaethylene glycol ether, and 0.2 ml 
of acetic acid (80%), and the dispersion made up to 100 ml by the addition 
of water. The dyestuff dispersion is cooled to room temperature and 
transferred, together with 66.6 g of a mixed fabric in the rolled-up 
state, consisting of 67% of polyethylene glycol terephthalate and 33% of 
wool, to a metal container; the container is sealed and well shaken. The 
container is then kept in continuous movement, in the usual manner, in the 
dyeing apparatus corresponding to Example 1; the bath temperature is 
raised within 15 minutes from 20.degree. to 130.degree. and this 
temperature maintained for 30 minutes. After cooling, the mixed fabric is 
removed; it is squeezed out to about 50% moisture content; it is 
subsequently rinsed with cold water, and then soaped with warm water 
containing 2 g/l of the addition product of 9 mols of ethylene oxide with 
1 mol of nonylphenol. 
An even navy blue dyeing well dyed throughout is obtained, with both fibre 
constituents being uniformly dyed. 
EXAMPLE 8 
An amount of 10 g of the dyestuff of the formula 
##STR11## 
(See C.I. No. 23635) is dissolved in 1500 ml of hot water; additions are 
then made to the solution of 10 g of octylphenol heptaethylene glycol 
ether, and 0.2 ml of acetic acid (80%), and the whole made up by the 
addition of water to 2000 ml. After cooling to room temperature, the 
dyestuff solution is sprayed in atomised form by means of a volumetric 
gear under a pressure of 25 atmospheres to pullovers rotating continuously 
in a drum at room temperature with a rotary speed of 25 revolutions per 
minute, the said pullovers being made from polyamide-6.6 and having a 
total weight of 1000 g. After completion of the atomisation spraying 
process, the indirect heating is switched on, with the drum still 
rotating, and by addition of 1000 ml of water to the bottom of the drum 
and evaporation of the water, an immediate formation of saturated steam in 
the drum is obtained, whilst the temperature is allowed to rise to 
98.degree.. Within 10 minutes there is produced in this manner a saturated 
steam atmosphere of 98.degree. and this then maintained for 20 minutes. 
The dyed material is subsequently cooled to a temperature of 70.degree. 
and then centrifuged in the dyeing drum until a residual moisture content 
of about 50% on the fibre is obtained. An amount of 2000 ml of water is 
thereupon applied by atomisation to the rotating dyed textile material. 
After completion of this atomisation washing treatment, the dyed material 
is centrifuged and afterwards dried with hot air at about 100.degree.. 
An even, non-streaky, brilliant red dyeing is obtained on pullovers made 
from polyamide-6.6 well dyed throughout and possessing good fastness 
properties. 
EXAMPLE 9 
An amount of 1.3 g of the disodium salt of copper phthalocyanine 
disulphonic acid is dissolved in 90 ml of hot water; additions are then 
made to the solution of 0.5 g of nonylphenol decaethylene glycol ether, 
and 0.8 g of sodium sulphate, and the liquor made up to 100 ml by the 
addition of water. After cooling to room temperature, the dyestuff 
solution is transferred together with 66.6 g of cotton fabric to a metal 
container such as is described in Example 1. With otherwise the procedure 
as given in Example 1, there is obtained an evenly dyed turquoise cotton 
fabric which is well dyed throughout and possesses good fastness to wet 
processing and to light. 
EXAMPLE 10 
An amount of 100 g of the dyestuff of the formula 
##STR12## 
is dissolved in 10 liters of hot water; additions are made to the solution 
of 30 g of nonylphenoldecaglycol ether and 30 ml of 80% acetic acid, and 
the dye liquor is made up with water to 15 liters. A sample of 10 kg of 
polyamide-6.6-pullover material is placed into a drum dyeing apparatus 
having a design enabling dyeing to be performed with concentrated 
goods-to-liquor ratios; the textile material is then sprayed evenly with 
the above described dye liquor cooled to room temperature. The drum is 
thereupon rotated at room temperature until the dye liquor is uniformly 
distributed through the material to be dyed. The rotation of the drum is 
maintained while the bath temperature is raised in the course of 20 
minutes from 20.degree. to 100.degree., and the bath held at this 
temperature for 20 minutes. After cooling, the dyed pullover material is 
treated in the drum dyeing apparatus by centrifuging to reduce the water 
content to ca. 50%. The dyed material is thereupon washed by being sprayed 
twice with 15 liters of water at 60.degree. for 5 minutes; it is again 
centrifuged to give a residual moisture content of ca. 50%, and then dried 
by means of an air stream at ca. 100.degree. for ca. 15 minutes. 
Blue polyamide-6.6 pullover material is obtained well dyed throughout, the 
said material possessing good fastness to wet processing and to light.