GB2024265A - Process for dyeing or printing hydrophobic, synthetic organic fibre materials - Google Patents

Abstract

A process for fast dyeing or printing hydrophobic, synthetic organic fibre material comprises using a water- insoluble disazopyrazole dyestuff of the general formula <IMAGE> wherein R1 represents hydrogen, (C1-C8) alkyl which is unsubstituted or substituted by one or more of the same or different substituents which do not confer solubility in water, or represents cyclohexyl or phenyl which is unsubstituted or substituted by one or more of the same or different substituents selected from methyl, methoxy, chlorine, bromine, and nitro, R2 and R3, independently of one another, each represents hydrogen or methyl or phenyl, R4 and R5, independently of one another, each represents hydrogen or a substituent which does not confer solubility in water, and A represents phenyl which is unsubstituted or substituted by one or more of the same or different substituents which do not confer solubility in water, or represents a 5-hydroxypyrazol-4-yl radical which in the 1-position carries hydrogen or beta -hydroxyethyl, beta - cyanoethyl or phenyl and in the 3- position carries methyl, (C1-C4)-alkoxycarbonyl or aminocarbonyl in which the amino group is unsubstituted or substituted by one or two of the same or different (C1-C4)alkyl radicals. The process provides level dyeings of polyester wool blends.

Description

SPECIFICATION Process for dyeing or printing hydrophobic, synthetic organic fibre materials The present invention provides a process for dyeing or printing hydrophobic, synthetic organic fibre material wherein there is used a water-insoluble disazopyrazole dyestuff of the general formula

in which R1 represents a hydrogen atom, an alkyl radical having 1 to 8 carbon atoms, which is unsubstituted or substituted by one or more of the same or different substituents which do not confer solubility in water, or a cyclohexyl group or a phenyl group, which is unsubstituted or substituted by one or more of the same or different substituents selected from methyl, methoxy, chlorine, bromine and nitro, R2 and R3, independently of one another, each represents a hydrogen atom or a methyl or phenyl group, R4 and R5, independently of one another, each represents a hydrogen atom or a substituentwhich does not confer solubility in water, such as, for example, a halogen atom, e.g. chlorine or bromine, or a nitro group or an alkyl or alkoxy radical each having 1 to 4 carbon atoms, e.g. i-propyl, n-butyl or i-propoxy, or, preferably, methyl, ethyl, methoxy or ethoxy, and A represents a phenyl group which is unsubstituted or substituted by one or more of the same or different substituents which do not confer solubility in water, or represents a 5-hydroxypyrazol-4-yl radical which in the 1-position carries a hydrogen atom or a p-hydroxyethyl, ss-cyanoethyl or phenyl group and in the 3-position carries a methyl group, a (C1-C4)alkoxycarbonyl radical, e.g. methoxycarbonyl, or an aminocarbonyl group in which the amino group is unsubstituted or substituted by one or two of the same or different alkyl radicals each having 1 to 4 carbon atoms, e.g. methylaminocarbonyl or diethylaminocarbonyl.

An alkyl radical having 1 to 8 carbon atoms (exclusive of substituents), represented by R1, is to be understood to mean a straight-chain or branched, saturated aliphatic hydrocarbon radical having 1 to 8 carbon atoms, such as, for example, methyl, ethyl, n- and i-propyl, n-, i-, sec.- and tert.-butyl, n-pentyl, i-amyl, n-hexyl and n-octyl and may be substituted by substituent(s) which do not confer solubility in water.These are; for example, hydroxy groups, halogen atoms, cyano groups, unsubstituted and substituted phenyl groups, (C1 -C4) alkoxy radicals, alkoxycarbonyl radicals in which the alkoxy moiety has from 1 to 4 carbon atoms, aminocarbonyl groups unsubstituted or substituted by one or two of the same or different (C1-C4)alkyl radicals, trifluoromethyl groups, nitro groups, alkyl-carbonyl radicals in which the alkyl moiety has from 1 to 4 carbon atoms, unsubstituted and substituted phenoxy groups and (C-C4) alkyl radicals.

Thus, for example, an alkyl group represented by P1 can be substituted, for example by one or more of the same or different substituents selected from hydroxy, halogen, e.g. chlorine or bromine, cyano, phenyl, alkoxy having 1 to 4 carbon atoms, e.g. methoxy or butoxy, (C,-C4) alkoxy-carbonyl, e.g. methoxycarbonyl or butoxycarbonyl, unsubstituted aminocarbonyl and aminocarbonyl in which the amino group is substituted by one or two of the same or different alkyl radicals each having 1 to 4 carbon atoms, e.g.

methylaminocarbonyl or diethylaminocarbonyl. Compounds in which an alkyl radical represented by R1 is unsubstituted or substituted by one or more of the same kind of substituent, especially by one substituent, should especially be mentioned.

A phenyl group represented by A can be substituted, for example by one or more of the same or different substituents selected from fluorine, chlorine, bromine, hydroxy, (C1-C4)alkyl, (C1-C4)alkoxy, phenyl, phenoxy, trifluoromethyl, nitro, (C1-C4)alkyl-carbonyl,(C1-C4)-alkoxy-carbonyl and cyano.

The su bstitu ents which do not confer so flu ability in water and which may be represented by R4 and/or P5 are preferably halogen, nitro and alkyl and alkoxy each having 1 to 4 carbon atoms.

Amongst the dyestuffs of the general formula I, which has been given, those preferably used according to the process are those of the general formula

in which R1, R4 and P5 have the meanings indicated above and in which the benzene radical B is unsubstituted or monosubstituted to trisubstituted by the same or different substituents which do not confer solubility in water, such as, for example, hydroxy, methyl, ethyl, phenyl, methoxy, ethoxy, phenoxy, chlorine, bromine, fluorine, trifluoromethyl, nitro, methylcarbonyl, methoxycarbonyl, ethoxycarbonyl and/or cyano.

Hydrophobic synthetic organic fibre materials suitable for the dyeing and printing process according to the invention are, for example, those made of cellulose esters, polyamides, polyesters, polyurethanes, polyolefins, polycarbonates and polyacrylonitriles. Those made of cellulose esters, e.g; cellulose diacetate, cellulose 2 -acetate or cellulose triacetate, polyamides, e.g. polycaprolactam or polyhexamethylenediamine adipate, and, more especially, those made of polyesters, e.g. polyethylene glycol terephthalate, are preferred. The synthetic fibre materials may be subjected to the dyeing and printing process according to the invention not only in the pure form but also in the form of mixtures with one another or with natural fibre materials, e.g. cellulose fibres or wool.A material containing no synthetic fibre material but comprising wool may also be dyed by the process of the present invention.

The fibre materials can be in very diverse stages of processing, for example in the form of filaments, flocks or tops, in the form of piece goods, for example woven fabrics, knitted fabrics or non-wovens, or in the form of made-up goods.

When the disazopyrazole dyestuffs of the indicated formula I are used according to the invention for dyeing or printing the said fiber materials, the dyestuffs are usually employed in the form of a preparation, such as, for example, in the form of an aqueous dispersion or solution in organic solvents or in the form of an emulsion or dispersion, which can also contain water in addition to a solvent or solvent mixture.

In order to prepare dispersions, the dyestuffs are finely divided in the presence of dispersing agents and optionally further assistants. Aqueous dispersions in particular are very suitable for the preparation of dry dyestuff preparations, which then contain the dispersing agents employed and any grinding assistants which may have been employed, in addition to the particular dyestuff. An essential characteristic of such dyestuff preparations is that when they are introduced into water they again give a dyestuff dispersion with a degree of fine division the same as that which existed prior to drying, without the use of special fine-dispersion devices. Drying can be carried out in ambient air, in drying equipment which operates under normal pressure or in vacuo, or by spray-drying in equipment suitable for this.

Dyeing is carried out by processes which are in themselves known and the dyeing conditions largely depend on the nature of the synthetic fiber materials and their stage of processing.

Polyester fibers, for example, are preferably dyed from aqueous dispersion at temperatures above 100 C under pressure. However, the dyeings can also be carried out at the boiling point of water in the presence of carriers, such as, for example, phenylphenols, polychlorobenzene compounds, methylnaphthalene or simiiar assistants. Furthermore, deep dyeings are obtained when woven fabrics or knitted fabrics made of polyester fibers are impregnated with aqueous suspensions of one of the pyrazole dyestuffs or a mixture of these dyestuffs and are then subjected briefly to the action of heat, for example at temperatures of 180 to 210"C.

Fiber materials made of cellulose 2 1/2-acetate are preferably dyed at temperatures of 65 to 85"C, and those made of cellulose triacetate are preferably dyed at temperatures of 65 to about 11 5 C. Fiber materials made of polyamide are usually dyed in the region of the boiling point in the range between 90 and 95"C. The use of carriers is not necessary when dyeing cellulose 2 1/2-acetate or polyamide fibers.

The most advantageous pH range for the dyebaths from which the abovementioned substrates are dyed is between 2 and 9 and preferably between 4 and 8.

The pH is adjusted to the desired value using, for example, aqueous solutions of ammonium sulfate, sodium o-phosphate or ammonium o-phosphate, sodium acetate, sulfuric acid or acetic acid.

In order to improve the fastness to rubbing, the dyed material is appropriately freed from dyestuff adhering to the surface, for example by careful rinsing, but especially by conventional after-treatment processes, such as washing with emulsifiers or reductive after-treatment.

When the fiber materials listed are dyed from organic solvents, either uptake of the disazopyrazole dyestuff from the solution by the substrate is allowed to take place, preferably at 70 to 1 30"C, by the exhaustion process, which operates discontinuously, or dyeing is carried out by the thermosol process, which operates continuously and with which the substrate, which, for example, is in the form of woven fabric, is impregnated with an organic dyestuff solution and is then dried and subjected briefly to the action of heat, for example at 180 to 210 C.

Solvents which may be mentioned for the exhaustion process are water-immiscible solvents with boiling points between 40 and 1 70 C, such as, for example, the aliphatic halogenated hydrocarbons, such as methylene chloride, trichloroethane, trichlorethylene and perchloroethylene.

Solvents which can be used for the dyeing process which operates continuously are, preferably, also water-miscible solvents, such as, for example, alcohols, such as alkanols with 1 to 4 C atoms, or dimethylformamide. The solvents can also be in the form of mixtures and can contain further assistants soluble in the solvents, such as, for example, alkoxylation products of such as fatty alcohols, alkylphenols or fatty acids.

The production of prints on the said fiber materials by the use, according to the invention, of the disazopyrazole dyestuffs (I) is also effected by processes which are in themselves known.

On polyester fiber material, for example, the dyestuffs can be used in aqueous formulations which contain suitable thickeners and fixing accelerators in addition to the finely divided dyestuff. Fixing is carried out, for example, after printing and drying, by steaming under atmospheric pressure for 30 to 60 minutes or under an elevated pressure of up to 2 atmospheres gauge for 10 to 30 minutes. Fixing can also be effected by the action of superheated steam or hot air at a temperature of 150 to 220"C for 30 to 90 seconds.

Furthermore, the disazopyrazole dyestuffs (I) are suitable for the production of prints by the transfer printing process, and materials which can be printed are not only the said synthetic fiber materials and mixtures thereof with one another or with natural fiber materials but optionally also correspondingly finished natural fibers, such as cellulose fibers, which, for example, have been treated with suitable synthetic resins prior to printing. For this purpose, printing inks, which in addition to the finely divided dyestuff contain binders, water and/or an organic solvent, are first applied to an inert support, for example to plastic films or aluminum foils which are stable at the temperatures employed, but preferably to paper, and dried.The treated side of the support is then brought into contact with the surface of the fiber material, for example polyester woven fabric, nonwoven or knitted fabric, the support and the fiber material are then subjected to the action of heat, e.g. at 150 to 2300C and advantageously 170 to 210"C, for e.g. 2 to 60 seconds if appropriate under mechanical pressure, and the dyed fiber material is then separated from the support.

The use, according to the invention, of the disazopyrazole dyestuffs of the indicated formula (I), the uptake of which, which in itself is excellent, can be even further improved by mixing two or more of the said dyestuffs, enables bright and clear yellow to brown deep dyeings, which have very good fastness to wet processing, washing, sublimation, waste gas and light, to be obtained on the said fiber materials.

The disazaopyrazole dyestuffs of the formula (I) are of particular importance for dyeing mixed fabrics made of polyester fibers and wool. Specifically, it is observed that when a polyester fabric and a wool fabric are dyed at the same time in one and the same dyebath, the dyestuff is taken up not only by the polyester material but also by the wool fabric. This characteristic of the disazopyrazole dyestuffs, which in itself would have to be regarded as indicating "poor reservation" of wool and which as a rule is undesirable in the case of disperse dyestuffs, is assessed as advantageous in the present case, because of the high quality of the wool dyeings.

Thus, compared with the polyester fabric, the wool fabric is dyed in virtually the same color shade and with virtually the same depth of color. The high level of the fastness properties of the wool dyeings manifests itself, for example, in a very good fastness to light, perspiration and washing. On conventional after-treatment of the dyeings by a wash with emulsifiers or by treatment with reducing agents, not only the dyeing of the polyester fabric but also that of the wool fabric undergoes no discernible change in the color shade and no discernible change in the depth of color.

These unusual coloristic properties, which are regarded as exceedingly advantageous, of the said disazopyrazole dyestuffs make it superfluous, in the given cases when dyeing polyester/wool mixed fabrics, to use so-called mixed dyestuffs, which consist of a mixture of a disperse dyestuff for dyeing the polyester and a special dyestuff for dyeing the wool.

The disazopyrazole dyestuffs which are used according to the invention can be manufactured in a manner which is in itself known: Thus, for example, it is possible to couple diazotized aminoazo compounds of the formula (III)

with 1,3-dicarbonyl compounds of the formula (lV)

and to react the resulting coupling products of the formula

with hydrazinesoftheformula (VI) H2N - NH - R1 (Vl) to give the dyestuffs of the formula (I). In the above formulae Ill to VI, R1, R2, R3, R4, R5 and A have the meanings indicated further above.

However, in all cases in which A represents the radical of a compound which can be coupled, such as the radical of a phenol or pyrazolone, the procedure employed for the manufacture of the pyrazole dyestuffs which are used according to the process can be to couple monodiazotized p-phenyldiamines of the formula

with 1,3-dicarbonyl compounds of the indicated formula (IV) and either to subject the coupling products of the formula (VIII)

which are thus obtained, to further diazotization immediately and to allow the resulting products to react with compounds of the formula (IX) A-H (IX) which can be coupled, to give the coupling products of the formula (X)

and then to react the latter with hydrazines of the indicated formula (VI) to give the desired dyestuffs, or, alternatively, first to react the resulting coupling products of the formula (VIII) with hydrazines of the formula (Vl),to diazotizethe resulting cyclization products of the formula (Xl)

and to couple the resulting products with compounds of the formula (iX) to give the disazopyrazole dyestuffs of the formula (I). In the above formulae VII to Xl, P1, R2, R3, R4 and P5 have the meanings indicated further above.

If the synthesis of the dyestuffs is carried out in one of the ways described above, using 1,3-dicarbonyl compounds as the coupling component, the 1,3-dicarbonyl compounds used are appropriately the following compounds: malonodialdehyde, acetoacetaldehyde, acetylacetone, formylacetophenone, benzoylacetone and dibenzoylacetone and also derivatives of these compounds, such as dimethylaminoacrolein, 1,1dimethoxybutan-3-one and 4-diethylaminobuten-2-one, with which, after coupling is complete, the coupling products are in the form of the 1,3-dicarbonylazo compounds.

When 1,3-dicarbonyl compounds of unsymmetrical structure (R2 + R3) are used, an isomeric mixture of the two dyestuffs of the general formula (i) and (XII) is isolated after formation of the pyrazole.

The examples which follow are intended to illustrate the invention. In these examples, parts denote parts by weight. Parts by volume are expressly stated to be such, and the relationship between parts by volume and liter is the same as that between part and kilogram.

Example 1: 15 parts of the dyestuff of the formula

15 parts of a commercially available condensation product of formaldehyde and a naphthalenesulfonic acid, which is an ionic dispersing assistant, and 120 parts of water are ground to a fine dispersion in a ball mill.

This dispersion is evaporated down at 60"C in a circulating air drying cabinet to give a dyestuff preparation which is readily storable and which, as required, on introduction into water gives a dispersion suitable for use of the dyestuff.

A dyebath is prepared from 2 parts of the resulting dyestuff preparation, 2000 parts of water and 7 parts of a commercially available dyeing accelerator based on methylnaphthalene. 140 parts of a 55/45 mixed fabric of polyethylene terephthalate fiber/wool are introduced, at 60"C, into this dyebath, the pH of which is adjusted to about 5 with ammonium sulfate and acetic acid, the bath is heated to 104 to 1 060C in the course of 60 minutes and dyeing is carried out at this temperature for 90 minutes in a closed apparatus.For after-treatment, the dyed mixed fabric is subjected to a wash with emulsifier, being exposed for 20 minutes at 95"C to an aqueous bath which contains, per 1000 parts, 2 parts of a commercially available emulsifying agent based on a highly oxethylated vegetable fat and 0.4 part of glacial acetic acid. It is then rinsed and dried.

A polyester/wool mixed fabric dyed in a deep reddish-tinged yellow with good fastness properties is obtained. Amongst the fastness properties, the high fastness to light, perspiration and washing may be singled out in particular.

The abovementioned dyestuff can be prepared as follows: 19.7 parts of 4-aminoazobenzene are suspended in 150 parts of water and 30 parts by volume of concentrated hydrochloric acid and diazotized with 6.9 parts of sodium nitrite, which are dissolved in about 20 parts of water, at 10-15"C in the course of one hour. The resulting diazonium salt solution is clarified and first 11 parts of acetylacetone and then 29 percent strength sodium acetate solution are added, the latter being added until, in the pH range of 4 to 5, the coupling reaction starts. The coupling product, which is obtained as crystals, is filtered off, washed with water until salt-free and, in the form of the aqueous paste, dissolved at 80"C in 100 parts by volume of dimethylformamide.After adding 4.8 parts of hydrazine in the form of 7.5 parts of an 80 percent strength aqueous solution of hydrazine hydrate, the reaction mixture is kept at the indicated temperature for a further 30 minutes. The cyclization which takes place during this time can be followed easily by thin layer chromatography. The dyestuff formed is then precipitated by adding 200 to 400 parts of water and is filtered off and washed until free from dimethylformamide.

Example 2: 100 parts of yarn made of polyethylene glycol terephthalate are dyed for 1.5 hours at 95 to 98"C from 2000 parts of a dyebath which contains 1 part of the dyestuff of the formula

in the finely dispersed form, 12 parts of a commercially available dyeing accelerator based on o-phenylphenol and 12 parts of ammonium o-phosphate.

The dyed material is then subjected to reductive after-treatment for 20 minutes at 80"C in another bath, which contains, per 1000 parts, 2 parts of sodium dithionite and 2 parts of 33 percent strength by weight sodium hydroxide solution, and is then carefully rinsed and dried.

With very good exhaustion of the dyebath, a polyester yarn dyed in a reddish-tinged yellow is obtained.

The dyeing is distinguished by good fastness properties and amongst these the very good fastness to light is to be mentioned in particular.

The abovementioned dyestuff can be prepared by following the instructions given in Example 1 but replacing the 19.7 parts of 4-aminoazobenzene by 21.1 parts of 4-methyl-4'-aminoazobenzene.

Example 3: 0.08 oart of the dvestuff of the formula

is dissolved in 8 parts of dimethylformamide. This solution is poured, whilst stirring, into 400 parts of water, to which 1 part of a commercially available, non-ionic dyeing assistant, which has a dispersing and levelling action and is based on a highly oxethylated vegetable fat, has been added beforehand.

8 parts of a polyamide fabric based on caprolactam are introduced, at 40"C, into the dyebath prepared in this way, the pH value of the bath having been adjusted to 5 with ammonium sulfate and acetic acid.

The bath is then heated to 90 to 950C in the course of 45 minutes and is kept at this temperature for 1 hour.

The fabric dyed in this ways is rinsed with water, after-treated for 10 minutes at 50"C in another bath which contains, per 1000 parts of water, 1 part of a commercially available wetting, washing and dispersing agent based on an oxethylated alkylphenol, rinsed again with water and dried.

With good exhaustion of the dyebath, a reddish-tinged yellow dyeing with good fastness properties, amongst which the fastness to light is particularly surprising, is thus obtained on the said poiyamide fabric.

Example 4: 0.2 part of the dyestuff of the formula

is finely dispersed in 200 parts of water in the customary manner. After the pH value has been adjusted to 4-5 with small amounts of an aqueous sulfuric acid, 20 parts of a polyester fabric are dyed for 1 hour at 130"C in the dye-bath prepared in this way, in a closed apparatus. The dyed material is then subjected to after-treatment and finishing as described in Example 2.

The reddish-tinged yellow dyeing obtained is distinguished by good fastness properties.

The said dye can also be obtained in accordance with the instructions given in Example 1 if 21.1 parts of 4'-methyl-4-aminoazobenzene are employed in place of 19.7 parts of 4-aminoazobenzene and 13.8 parts of ss-hydroxyethylhydrazine are employed in place of 4.8 parts of hydrazine.

Example 5: 15 parts of the dyestuff of the formula

15 parts of a commercially available formaldehyde/naphthalenesulfonic acid condensation product and 120 parts of water are ground to a fine dispersion in a ball mill and the dispersion is then made up to 2000 parts with water.

Using this dye liquor, polyester fabric is impregnated on a padder in the customary manner. The fabric is then squeezed off to a liquor pick-up of 70 %, dried at about 100 C in a dryer and then treated with hot air at 210"C for about 60 seconds. The dyed material is rinsed with water, subjected to reductive after-treatment in the manner described in Example 2, rinsed again and dried.

Deep dyeings in a yellowish-tinged red with good fastness properties are thus obtained.

The dyestuff employed in this example can be prepared as follows: 50 parts of acetic acid are added to a solution of 2.72 parts of 4'-nitro-4-amino-methoxy-azobenzene in 50 parts of dimethylformamide.

The resulting mixture is cooled to 20 to 25"C and 2 parts by volume of 5N sodium nitrite solution and then 6 parts by volume of 5N hydrochloric acid are added, after which the aminoazo compound rapidly undergoes complete diazotization. The diazonium salt formed is coupled with acetylacetone, by introducing first 1.2 parts of acetylacetone and then 5 parts of sodium acetate (NaC2H302. 3 H2O) into the reaction mixture.

The resulting mixture is then warmed to 800C and 1.1 parts of ss-hydroxyethylhydrazine are added. The disazopyrazole dyestuff which now forms is precipitated from the dimethylformamide solution, whilst this is still warm, by adding water and is filtered off and washed until free from solvent.

Example 6: Using a solution of 10 parts of the dyestuff of the formula

in 1000 parts by volume of perchloroethylene, polyester fabric is impregnated on a padder in the customary manner, squeezed offto a liquor pick-up of about 90 % and dried at about 100"C in a dryer. The dyeing is then fixed for 60 seconds with hot air at 21 0'C. The dyed fabric is then rinsed at room temperature with perchloroethylene and then dried.

The yellowish-tinged red dyeing obtained on the polyester fabric is distinguished by good fastness properties.

The dyestuff employed in this example can be prepared in accordance with the instructions given in Example 5, using 1.1 parts of ss-cyanoethylhydrazine in place of 1.1 parts of B-hydroxyethylhydrazine.

Example 7: A polyester fabric is printed with a printing paste which contains, per 1000 parts, 200 parts of a 10 percent strength by weight aqueous dispersion of the dyestuff of the formula

in addition to the commercially available thickener alginate and further conventional additives, and dried.

The print is then fixed for 60 seconds with hot air at 200"C. The printed fabric is then subjected to a reductive after-treatment, rinsed with water and dried.

Yellowish-tinged red prints with good fastness properties are obtained by a procedure carried out in this way.

Example 8: 50 parts of the dyestuff of the formula

5 parts of a formaldehyde/naphthalenesulfonic acid condensation product and 70 parts of water are ground in a ball mill until the dyestuff is in an adequate state of fine division.

100 parts of this 40 percent strength by weight dyestuff preparation are stirred into 960 parts of a commercially available varnish.

The printing ink thus obtained is then applied to paper using a gravure printing machine. If this paper is pressed for 30 seconds at 200"C with a fabric made of polyester fibers, a deep print in reddish-tinged yellow with very good fastness properties is obtained on the polyester material.

The dyestuff mentioned here can be prepared by the process described in Example 1, by employing 22.5 parts of 3,4'-dimethyl-4-aminoazobenzene in place of 19.7 parts of 4-aminoazobenzene and 6.9 parts of methylhydrazine in place of 4.8 parts of hydrazine.

Further dyestuffs of the general formula I which are used according to the process are listed in Tables 1 - 5 which follow.

The dyestuffs in Table 1 can be prepared in accordance with the instructions given in Example 1, equivalent amounts of substituted 4-aminoazobenzenes being employed in place of the 19.7 parts by weight of 4-aminoazobenzene.

Table 1 Example Dyestuff Color shade on poly ester fibers

reddish tinged yellow reddish tinged yellow reddish tinged yellow reddish tinged yellow Example Dyestuff Color shade.

on polyester fibers

reddish tinged yellow reddish tinged yellow reddishtinged yellow reddishtinged yellow reddishtinged yellow reddish tinged yellow Example Dyestuff or Color shade on polyester fibers

reddishtinged yellow reddishtinged yellow reddish tinged yellow reddish tipged yellow reddish tinged yellow reddish tinged yellow If, in Example 1, equivalent amounts of monosubstituted hydrazines are used in place of the 4.8 parts by weight of hydrazine, the dyestuffs listed in Table 2 are obtain-ed; these give reddish-tinged yellow dyeings on polyester fabric.

Table 2 Example Dyestuff Color shade on polyester fibers

reddishtinged yellow reddishtinged yellow reddish-.

tinged yellow reddishtinged yellow reddishtinged yellow reddishtinged yellow reddishtinged yellow !Example Dyestuff Color shade on polyester fibers

reddish tinged yellow reddish tinged yellow reddish tinged yellow reddish- tinged yellow reddish tinged yellow reddish t-inged yellow reddish tinged yellow Example Dyestuff Color shade on polyester fibers.

reddish tinged yellow reddish tinged yellow reddish tinged yellow reddish tinged yellow reddish tinged yellow Example 44:

18 parts of benzoylacetone are added to the diazonium salt solution obtained according to Example 1 from 19.7 parts of 4-aminoazobenzene, and 29 percent strength sodium acetate solution is then added until, in the pH range of 4 to 5, coupling takes place. The coupling product which is then isolated is dissolved in 100 parts by volume of dimethylformamide. 8.5 parts of ss-hydroxyethylhydrazine are added to this solution and the mixture is kept at 80"C for 30 minutes, during which time the pyrazole ring forms, as can be followed easily by thin layer chromatography.After the resulting dyestuff has been precipitated, in the form of good crystals, from the warm dimethylformamide solution by slowly adding about 300 parts of water, it is filtered off, washed until free from solvent and dried. If this dyestuff is used to dye polyester fabric, deep, reddish-tinged yellow dyeings are obtained which have very good coloristic fastness properties, amongst which the high fastness to light is to be mentioned in particular.

When an unsymmetrical 1 ,3-dicarbonyl compound is used, a dyestuff mixture is obtained in which the two components have the following formulae

The existence of such a mixture of isomers is expressed at the beginning of this example by a single formula in which the methyl group and the phenyl group are shown in indefinite positions on the pyrazole ring. The same applies correspondingly for some of the dyestuffs in Table 3 which follows, which are accessible analogously to the instructions of Example 44 or 1. The corresponding compounds, in the form of which the 1,3-dicarbonyl compounds are used, are given in column 2 of this table.

Table 3 Example 1,3-Dicarbonyl Dyestuff Color compound employed shade in the form of: on poly ester fibers

CH3 .

45 Benzoyl- O -M N=N Xt reddish acetone 9 N-c2H4GN tinged c6 yellow tos3 46 ' ,I N=N-2-NeNg 11 CF &commat;3~N=NiN " O ; CG HS Cç HS 48 Dibenzoyl- y N-N e -N=N ss I acetone Dimethylamino- o N o N Re X h- $ N 1l 49 acro1einamino -.x--.ll Ex- 1,3-Dicarbonyl Dyestuff Color ample compound shade on employed in poly the form of: ester fibers

Oou c$ 5Q l,l-Dimethoxy- G2i'- O li NLN- yellowis-t yellowishF H brotm cf 31 a OZH51 1 reddish-4 4 -C2H4Cä tinged CG HS yellow phenone Formylaceto- y N=N e Il=N tinged phenone Formylaceto- GH tinged H yellow Further dyestuffs which are accessible analogously to the instructions of Example 5 are listed in Table 4.

Table 4 Example Dyestuff Color shade on poly ester fibers

M3C)O CR 53 '2 4 -N-N 4 N=N 9 brown tinged brown OCH CHa 54 2 4 hWN X OCLo CLO 55 t)2N e -N= 4 k i: Example Dyestuff. Color shade on poly ester fibers

/OCRJ CH3 56 02X- 5 N=N =N < \ . yellowish tinged brown /OUR3 C 57 02N4D-H=S8 == N~$ CH3 58 O?N o OH e -N=~ tinged yellow C 5.9 02N o N N O t CN C1 OC; C 60 y -N===N S N===1Q C1 MOCHA Cç.

II 6I EI=L c CH2-OH d N C' CJ 62 s,CoN=N- (I u I d -CH2 GH2 - E CH2 -OH Example Dyestuff Color shade on poly ester fibers

- - CLe G3 Ha C0''--= I~\ reddish =2 r N-CCH2-CB tinged CHa Ha CHe yellow CR w CHa 64 d N"='-N-N= CHa I1 CHa Example 65::

10.8 parts of p-phenyldiamine in 1 00 parts of water are monodiazotized at O-50C in the pH range of 1.5 to 3.5 by alternately adding a total of about 40 parts by volume of 5N hydrochloric acid and 20 parts by volume of 5N sodium nitrite solution.After clarifying the diazonium solution, the 4-amino-benzenediazonium chloride is coupled, after adding 50 parts by volume of 4N sodium acetate solution, with 11 parts by weight of acetylacetone to give the aminoazo compound of the formula

The reaction mixture is then acidified with mineral acid, using 80 parts by volume of 5N hydrochloric acid, the temperature is kept at O to 5"C by adding ice and the amino group which is still free is diazotized with 18 parts by volume of 5N sodium nitrite solution. The diazonium solution which is now obtained is allowed to run into a solution of 9.4 parts of phenol in 50 parts by volume of 2N sodium hydroxide solution and 400 parts by volume of 2N sodium carbonate solution.The resulting disazo compound of the formula

is filtered off with sharp suction, taken up in 200 parts by volume of ethanol and reacted atthe boiling point of the alcohol with 7.6 parts of p-hydroxyethylhydrazineto give the desired disazopyrazole dyestuff.

After cooling the reaction mixture, the dyestuff which has formed is filtered off, washed until free from solvent and dried. Using this dyestuff, reddish-tinged yellow dyeings with good fastness properties from the point of view of dyeing technology can be obtained on polyester fabrics.

Example 66:

14.3 parts 2-chloro-1 ,4-diaminobenzene in 100 parts of water are monodiazotized at 0-5"C in the pH range of 1.5 to 3.5 by alternately adding a total of about 40 parts by volume of 5N hydrochloric acid and 20 parts by volume of 5N sodium nitrite solution. The diazonium solution which is a solution of the isomeric 2- and 3-chloro-4-amino-benzene-diazonium chlorides, is clarified with kieselguhr. It is then coupled with acetylacetone, by adding 11 parts of the 1,3-dicarbonyl compound and acidifying the reaction mixture with acetic acid, using 50 parts by volume of 4N sodium acetate solution.

The coupling product of the formula

which is obtained as crystals, is filtered of, dissolved in 100 parts by volume of dimethylformamide at 80"C and reacted at this temperature with 8.5 parts of -cyanoethylhydrazine to give the aminoazopyrazole of the formula

This aminoazo compound is then diazotized at 10 to 15"C in the existing dimethylformamide solution, after adding 60 parts by volume of 5N hydrochloric acid, with a 5N sodium nitrite solution.

The resulting diazonium solution is added to a solution of 13.6 parts of 2-hydroxy-acetophenone in 200 parts by volume of 2N sodium carbonate solution, whereupon the disazopyrazole dyestuff forms; this is a mixture of two isomeric compounds which differ in respect of the position of the chlorine atom in the phenyl ring. Using this dyestuff mixture, dyeings in a clear reddish-tinged yellow which are fast to light are obtained on polyester fibers.

A number of further disazopyrazole dyestuffs which are accessible according to Example 65 and 66 are listed in Table 5 which follows.

Table 5 Example Dyestuff Color shade on polyester fibers

reddishtinged yellow " " " " Example Dyestuff Color shade on polyester fibers

reddish-tinged yellow " " " 11 " " Example Dyestuff Color shade on polyester fibers

reddishtinged yellow " " Ia "

Claims (17)

1. A process for dyeing or printing material comprising hydrophobic, synthetic organic fibres and/or wool, which comprises using a water-insoluble disazopyrazole dyestuff of the general formula

wherein R1 represents a hydrogen atom or an alkyl radical having 1 to 8 carbon atoms, which is unsubstituted or substituted by one or more of the same or different substituents not conferring solubility in water, or represents a cyclohexyl group or a phenyl group which is unsubstituted or substituted by one or more of the same or different substituents selected from methyl, methoxy, chlorine, bromine and nitro, R2 and P3, independently of one another, each represents a hydrogen atom or a methyl or phenyl group, R4 and P5, independently of one another, each represents a hydrogen atom or a substituent which does not confer solubility in water, and A represents a phenyl group which is unsubstituted or substituted by one or more of the same or different substituents not conferring solubility in water, or represents a 5-hydroxypyrazol-4-yl radical which in the 1-position carries a hydrogen atom or a ss-hydroxyethyl, p-cyanoethyl or phenyl group, and in the 3-position carries a methyl group, an alkoxycarbonyl radical in which the alkoxy moiety has from 1 to 4 carbon atoms or an aminocarbonyl group which is unsubstituted or substituted by one or two of the same or different (C1-C4)alkyl radicals.

2. A process as claimed in claim 1, wherein, in the general formula I, the phenyl group represented by A is unsubstituted or substituted by one or more of the same or different substituents selected from fluorine, chlorine and bromine atoms, hydroxy groups, (C1-C4)alkyl groups, (C1-C4)alkoxy groups, phenyl, phenoxy, trifluoromethyl and nitro groups, alkylcarbonyl groups in which the alkyl moiety has 1 to 4 carbon atoms, alkoxycarbonyl groups in which the alkoxy moiety has 1 to 4 carbon atoms and cyano groups.

3. A process as claimed in claim 1, wherein, in the general formula I, the phenyl group represented by A is substituted by one or more fluorine, chlorine or bromine atoms or by one or more of the same or different substituents selected from hydroxy groups,(C-C4)alkyl, (C1-C4)alkoxy, phenyl, phenoxy, trifluoromethyl and nitro groups, alkylcarbonyl groups in which the alkyl moiety has 1 to 4 carbon atoms, alkoxycarbonyl groups in which the alkoxy moiety has 1 to 4 carbon atoms and cyano groups.

4. A process as claimed in claim 1, wherein the disazopyrazole dyestuff of the general formula I has the general formula

in which RX, R4 and P5 have the meanings given in claim 1 and the benzene radical B is unsubstituted or substituted by 1 to 3 of the same or different su bstituents selected from hydroxy, methyl, ethyl, phenyl, methoxy, ethoxy, phenoxy, chlorine, bromine, fluorine, trifluoromethyl, nitro, methylcarbonyl, methoxycarbonyl, ethoxycarbonyl and cyano.

5. A process as claimed in any one of claims 1 to 4, wherein, in the general formula I, the phenyl group represented by R1 is unsubstituted or substituted by one or more methyl, methoxy or nitro groups or chlorine or bromine atoms.

6. A process as claimed in any one of claims 1 to 4, wherein, in the general formula I, the alkyl group represented by R1 is unsubstituted or substituted by one or more of the same or different substituents selected from halogen atoms, hydroxy, cyano, phenyl and (C,-C4)alkoxy groups, alkoxycarbonyl groups in which the alkoxy moiety has from 1 to 4 carbon atoms, aminocarbonyl and N-monoalkylaminocarbonyl and N,N-dialkylaminocarbonyi groups in which the or each alkyl group has from 1 to 4 carbon atoms.

7. A process as claimed in claim 6, wherein, in the general formula I, the alkyl group represented by R is substituted by one or more halogen atoms or by one or more hydroxy, cyano, phenyl, alkoxy, alkoxycarbonyl, aminocarbonyl, N-monoalkylaminocarbonyl or N,N-dialkylaminocarbonyl groups.

8. A process as claimed in any one of claims 1 to 7, wherein, in the general formula I, R4 and P5, independently of one another, each represents a hydrogen or halogen atom, or a nitro, (C1-C4)alkyl or (C1-C4)-alkoxy group.

9. A process as claimed in claim 8, wherein, in the general formula I, R4 and R5, independently of one another, each represents a methyl, ethyl, methoxy or ethoxy group.

10. A process as claimed in any one of claims 1 to 9, wherein the material is in the form of filaments, flocks, tops, woven fabric, knitted fabric or non-woven material.

11. A process as claimed in any one of claims 1 to 10, wherein the material comprises cellulose ester, polyamide, polyester, polyurethane, polyolefin, polyacrylonitrile or polycarbonate.

12. A process as claimed in claim 11, wherein the material comprises cellulose diacetate, 21/2-acetate or triacetate, polycaprolactam or polyhexamethylenediamine adipate.

13. A process as claimed in any one of claims 1 to 12, wherein the material contains cellulose and/or wool.

14. A process as claimed in claim 13, wherein the material is polyester-wool.

15. A process as claimed in any one of claims 1 to 14, wherein there are used two or more dyestuffs of the general formula I.

16. A process as claimed in claim 1, carried out substantially as described in any one of the Examples herein.

17. Material comprising hydrophobic, synthetic organic fibres and/or wool, which has been dyed by a process as claimed in any one of claims 1 to 16.