Red Dye Mixtures and Their Use: Dyeing Natural or Synthetic Polyamides

The present invention relates to mixtures of red-dyeing dyes which are suitable for the dyeing of natural or synthetic textile polyamide fibre material from an aqueous bath and have very good fastness properties and show good exhaustion expecially in combination with other dyes, in particular from short liquors.

The present invention relates to a dye mixture containing a dye of the formula ##STR4## in which R.sub.1 is methyl or ethyl and at least one dye of the formulae (2) and (3) ##STR5## in which D is substituted or unsubstituted phenyl, thiophenyl or benzothiazolyl, R.sub.2 is C.sub.1 -C.sub.8 alkyl, R.sub.3 is substituted or unsubstituted C.sub.1 -C.sub.8 alkyl and R.sub.4 is hydrogen or C.sub.1 -C.sub.4 alkyl, and ##STR6## in which R.sub.5 is C.sub.1 -C.sub.4 alkyl.

The dye mixture according to the invention containing a dye of the formula (1) and a dye of the formula (2) or a dye of the formula (1) and a dye of the formula (3) is preferred.

Examples of suitable R.sub.2 and R.sub.3 radicals in formula (2) as C.sub.1 -C.sub.8 alkyl are, independently of one another, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, pentyl, hexyl, heptyl and octyl. R.sub.2 and R.sub.3 are preferably C.sub.1 -C.sub.4 alkyl.

R.sub.3 as C.sub.1 -C.sub.8 alkyl can be substituted, for example, by sulfo, sulfato or phenyl. Examples are benzyl, .beta.-sulfoethyl, .gamma.-sulfopropyl and .beta.-sulfatoethyl.

Examples of suitable R.sub.4 radicals in formula (2) and R.sub.5 radicals in formula (3) as C.sub.1 -C.sub.4 alkyl are, independently of one another, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl or isobutyl, in particular methyl.

D in formula (2) can be substituted, for example, by halogen, such as fluorine, chlorine or bromine, C.sub.1 -C.sub.4 alkyl, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl or isobutyl, C.sub.1 -C.sub.4 alkoxy, for example methoxy, ethoxy, propoxy or butoxy, C.sub.1 -C.sub.4 alkoxycarbonyl, for example methoxycarbonyl or ethoxycarbonyl, sulfo or C.sub.1 -C.sub.4 alkylaminosulfonyl which is unsubstituted or substituted in the alkyl portion by sulfo, for example methylaminosulfonyl, ethylaminosulfonyl or .beta.-sulfoethylaminosulfonyl.

Preference is given to a dye mixture containing at least one dye of the formula (2) in which D is phenyl, thiophenyl or benzthiazolyl, it being possible for each of the radicals mentioned to be substituted by halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkoxycarbonyl, sulfo or C.sub.1 -C.sub.4 alkylaminosulfonyl which is unsubstituted or substituted in the alkyl portion by sulfo, R.sub.2 is C.sub.1 -C.sub.4 alkyl, R.sub.3 is benzyl or C.sub.1 -C.sub.4 alkyl which is unsubstituted or substituted by sulfo or sulfato, and R.sub.4 is hydrogen or C.sub.1 -C.sub.4 alkyl. In the abovementioned dye mixture, the radical D of the dye of the formula (2) is preferably phenyl which is substituted by halogen, sulfo or C.sub.1 -C.sub.4 alkylaminosulfonyl which is unsubstituted or substituted in the alkyl portion by sulfo, or thiophenyl substituted by C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxycarbonyl, or benzothiophenyl which is unsubstituted or substituted by C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or sulfo.

Furthermore, preference is given to a dye mixture containing as dye of the formula (3) a dye of the formula ##STR7## in which R.sub.6 is C.sub.1 -C.sub.4 alkyl, in particular methyl.

Particular preference is given to a dye mixture containing at least one dye of the formula (2) in which D is phenyl which is substituted by chlorine, sulfo, methylaminosulfonyl, ethylaminosulfonyl or .beta.-sulfoethylaminosulfonyl, thiophenyl which is substituted by methyl, methoxy- or ethoxycarbonyl, or benzothiophenyl which is unsubstituted or substituted by methyl, methoxy or sulfo, R.sub.2 is C.sub.1 -C.sub.4 alkyl, R.sub.3 is benzyl or C.sub.1 -C.sub.4 alkyl which is unsubstituted or substituted by sulfo or sulfato, and R.sub.4 is hydrogen or C.sub.1 -C.sub.4 alkyl, and/or a dye of the formula (4) in which R.sub.6 is C.sub.1 -C.sub.4 alkyl, in particular methyl.

Very particular preference is given to a dye mixture containing a of the formula (1) in which R.sub.1 is methyl or ethyl, in particular methyl, and at least one dye of the formula (2) in which D is phenyl which is substituted by chlorine, sulfo, methylaminosulfonyl, ethylaminosulfonyl or .beta.-sulfoethylaminosulfonyl, thiophenyl which is substituted by methyl, methoxy- or ethoxycarbonyl, or benzothiophenyl which is unsubstituted or substituted by methyl, methoxy or sulfo, R.sub.2 is ethyl, R.sub.3 is ethyl, .beta.-sulfatoethyl, --(CH.sub.2).sub.2-3 --SO.sub.3 H or benzyl, and R.sub.4 is hydrogen or methyl, and/or a dye of the formula (4) in which R.sub.6 is methyl.

Particular importance is given to a dye mixture containing a dye of the formula (1) in which R.sub.1 is methyl or ethyl, in particular methyl, and at least one dye of the formulae (5) to (10) and (4): ##STR8## and a dye of the formula (4) in which R.sub.6 is methyl. The particularly important dye mixtures thus contain a dye of the formula (1) and at least one dye of the formulae (4), (5), (6), (7), (8), (9) and (10).

A dye mixture containing a dye of the formula (1) in which R.sub.1 is methyl or ethyl, in particular methyl, and at least one dye of the formulae (6), (7) or (8) is very particularly important.

In the dye mixtures according to the invention, the ratio of the dyes of the formulae (1) to (2) or (3) or the ratio of the dyes of the formulae (1) to (4), (5), (6), (7), (8), (9) or (10) of 10:90 to 90:10 and in particular 40:60 to 60:40 is preferred. The ratio of the dyes of the formulae (1) to (2) or (3) and in particular the ratio of the dyes of the formulae (1) to (4), (5), (6), (7), (8), (9) or (10) of 55:45 to 45:55 is very particularly preferred.

The dyes of the formulae (1), (2) and (3) are known per se or can be prepared in analogy to known dyes.

The dye mixture according to the invention can be prepared by mixing the individual dyes. This mixing process is carried out, for example, in suitable mills, for example ball and pinned-disc mills, and in kneaders or mixers.

Furthermore, the dye mixtures can be prepared by spray-drying of the aqueous dye mixtures.

The invention furthermore relates to a process for the dyeing and printing of natural or synthetic polyamide materials by means of the dye mixture according to the invention containing the dye of the formula (1) and at least one dye of the formulae (2) and (3). Examples of suitable synthetic polyamide materials are nylon-6,6 or nylon-6 fibre materials and an example of a suitable natural polyamide material is wool. The customary dyeing and printing processes are employed for the dyeing and printing.

The dye mixture containing the dye of the formula (1) and at least one dye of the formulae (2) and (3) is suitable in particular for the dyeing and printing in combination with other dyes and in particular for the dyeing and printing by the trichromatic principle. Trichromatic dyeing is understood as an additive dye mixing of three suitably chosen yellow-, red- and blue-dyeing dyes in the amounts necessary for obtaining the desired shade. The dye mixture according to the invention is suitable in particular for the dyeing from short liquors, for example in continuous dyeing processes or batchwise and continuous foam-dyeing processes.

The dye mixture according to the invention is distinguished by generally good properties, for example good solubility, stability of the solution in the cold, good exhaustion and in particular by good compatibility with other dyes and uniformly good exhaustion onto different fibre materials.

The textile material to be dyed or printed can be present in a wide range of processing forms, for example as fibre, yarn, woven or knitted fabrics and in particular in the form of carpets.

In the dye mixture according to the invention, the dyes of the formulae (1) and (2) or (3) are present either in the form of their free sulfonic acid or preferably as their salts, for example the alkali metal salts, alkaline earth metal salts or ammonium salts or as the salts of an organic amine. Examples are the sodium salts, lithium salts or ammonium salts or the salt of triethanolamine.

As a rule, the dye mixture contains further additives, for example common salt or dextrin.

The dye liquors or printing pastes can also contain further additives, for example wetting agents, antifoams, levelling agents or agents affecting the property of the textile material, for example softening agents, additives for flameproofing or soil-, water- and oil-repellent agents and water-softening agents and natural or synthetic thickeners, for example alginates and cellulose ethers.

In the examples which follow, parts are by weight. The temperatures given are in degrees centrigrade. Parts by weight relate to parts by volume as the gram relates to the cubic centimeter.

To prepare the dye mixture containing a dye of the formula ##STR9## and a dye of the formula ##STR10## or a dye of the formulae (101), (102) and (107), in a mixer, a) 30 parts of the dye of the formula (101) and 70 parts of the dye of the formula (102) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture A;

b) 60 parts of the dye of the formula (101) and 40 parts of the dye of the formula (104) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture B;

c) 80 parts of the dye of the formula (101) and 20 parts of the dye of the formula (103) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture C;

d) 30 parts of the dye of the formula (105) and 70 parts of the dye of the formula (101) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture D;

e) 60 parts of the dye of the formula (106) and 40 parts of the dye of the formula (101) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture E;

f) 80 parts of the dye of the formula (107) and 20 parts of the dye of the formula (101) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture F;

g) 10 parts of the dye of the formula (108) and 90 parts of the dye of the formula (101) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture G;

h) 50 parts of the dye of the formula (101), 25 parts of the dye of the formula (102) and 25 parts of the dye of the formula (107) are mixed homogeneously to give 100 parts of the mixture which hereinafter is called dye mixture H.

10 parts of a nylon-6,6 fibre material (Helance fabric) are dyed in 500 parts of an aqueous liquor containing 2 g/l of ammonium acetate and having a pH which has been adjusted to 5 with acetic acid. The dyes which are used are 0.12% of the red dye mixture A according to Example 1a), 0.27% of the yellow dye of the formula ##STR11## and 0.13% of the blue dye of the formula ##STR12## the amounts given being based on the weight of the fibres. The dyeing time at a temperature of 60.degree. to 98.degree. is 30 to 90 minutes. The dyed nylon-6,6 fibre material is then removed from the liquor and rinsed and dried as usual. This gives a piece of fabric completely levelly dyed in a neutral brown shade having no material-related streaks whatever.

Instead of 0.13% of the dye of the formula (110), it is also possible to use an equimolar amount of the dye C.I. Acid Blue 40, C.I. Acid Blue 258, C.I. Acid Blue 288, C.I. Acid Blue 324 or C.I. Acid Blue 336 in Example 2. Likewise, instead of 0.27% of the dye of the formula (109), it is possible to use an equimolar amount of the dye C.I. Acid Yellow 199 or C.I. Acid Yellow 219 in Example 2.

Example 2 is repeated, using the dyes of the formulae (109) and (110) listed in Table 1 below and the dye mixtures from Example 1 instead of 0.12% of the red dye mixture A and 0.27% of the yellow dye of the formula (109) and 0.13% of the blue dye of the formula (110), to give the pieces of fabric dyed completely levelly in the shade given.

The procedure of Example 2 is repeated, except that 0.12% of a red dye mixture consisting of 50 parts of the dye of the formula ##STR13## and 50 parts of the dye of the formula (107) is used instead of 0.12% of the red dye mixture A, to give a piece of fabric dyed completely levelly in a neutral brown shade.

10 parts of a nylon-6,6 yarn are dyed in 400 parts of an aqueous liquor containing 1.5 g/l of ammonium acetate and having a pH which has been adjusted to 5.5 with acetic acid. The dyes which are used are 0.12% of dye mixture B, 0.27% of the dye of the formula (109) and 0.13% of the dye of the formula (110), the amounts given being based on the weight of the fibres. The dyebath is heated to 98.degree. over a period of 30 minutes and maintained at 96.degree. to 98.degree. for 60 minutes. The dyed yarn is then removed from the dyebath and rinsed and dried as usual. This gives a yarn dyed in a neutral brown shade.

A beam dyeing apparatus (laboratory piece-dyeing apparatus, Model 10 from Rudolf Then) comprises, as its main parts, a horizontal dye boiler equipped with cooling jacket and connected with a secondary boiler which contains a special reversible pump to produce a circulation system.

This dyeing apparatus is entered with a beam charged with a nylon-6 loop pile carpet of 50 cm in width, 135 cm in length and a weight of 380 g. 6 liters of softened water were poured into the secondary boiler and 60 ml of 2N sodium hydroxide solution were added. By opening the corresponding valves (secondary boiler and connecting lines, pump/dye boiler), the liquor flows from the secondary boiler by gravity into the dye boiler, while the air displaced flows into the secondary boiler through a vent line. After the dyeing apparatus has been filled, the liquor remaining in the secondary boiler has a height of about 5 cm and then the circulating pump is turned on. To control the pH, a hole is drilled into the pipeline between the dye and secondary boiler (direction of flow) and a combination glass electrode is inserted. The dye liquor is circulating during the entire dyeing process from inside to outside, while the pressure gradient is 0.1 to 0.2 bar, and the delivery of the pump is about 6 liters per minute. The liquor is heated to 98.degree., and 7.6 g of an anionic levelling agent of high fibre affinity, dissolved in 100 ml of water, is added to the secondary boiler over a period of 5 minutes.

The dyeing temperature is adjusted to 97.degree. to 98.degree. while the pH is 10.7. The pH of the sample removed from the dyebath and cooled to 20.degree. is 11.9.

2.5 g of the red dye mixture B and 1.8 g of the yellow dye of the formula (109), both dissolved in 200 ml of hot water, are run in to the secondary boiler from a dropping funnel over a period of 10 minutes. After 30 minutes, a total of 100 ml of 1N sulfuric acid are metered in by means of a piston burette at a rate of 5.5 ml per minute over a period of 10 minutes and at a rate of 2.25 ml per minute over a further period of 20 minutes.

After another 10 minutes, the pH is 3.8. The dyebath is exhausted, i.e. more than 99% of the dyes has been absorbed by the material to be dyed. The heating is turned off, and the dye liquor is cooled to 60.degree. by means of indirect cooling. During this time, the pH increases to 3.9. The almost water-clear liquor is pumped back into the secondary boiler, and the beam is removed. The carpet material is unwound, centrifuged and dried. The nylon-6 loop pile carpet has been dyed uniformly levelly orange.