In the dyeing of polyamide fibres, especially polyamide microfibres, dark shades can be obtained by using acid dyes, although at the expense of good fastness-to-washing properties.

Conversely, good fastness-to-washing properties are obtained when dyeing with reactive dyes, although in that case dark shades are not readily obtained.

It has now been found that dark shades having a high degree of fastness to washing can be obtained if the polyamide fibre material is treated with a liquor comprising specific polyamines before, during or after dyeing.

The present invention relates to a method of increasing the depth of shade of dyed natural or synthetic polyamide fibre materials, which comprises treating the fibre material-before, during or after dyeing-with an aqueous liquor comprising a polyamine, the polyamine being the product of reaction of a compound containing at least two primary amino groups with ethylene oxide, propylene oxide, 1, 2-epoxybutane, a chloroalkylamine or an aromatic compound having at least one-COCI,-SO3CI or-SO=Z substituent wherein Z is vinyl, 2-chloroethyl or 2-sulfatoethyl, or the product of reaction of a compound containing at least two primary amino groups with an unsaturated aliphatic cyano compound and subsequent hydrogenation.

Large numbers of compounds containing at least two primary amino groups are known and commercially available.

Aliphatic, aromatic, araliphatic or cydoaliphatic di-or poly-amines can be used to prepare the polyamines that can be used in the method according to the invention. In this context, aromatic di-and poly-amines are understood to indude both carbocydic and heterocydic compounds. Similarly, the term"cycloaliphatic compounds"includes both carbocydic and heterocydic ring systems.

Examples of suitable diamines are aliphatic diamines such as, for example, 1, 2-diamino- ethane, 1,2-diaminopropane, 1,3-diaminopropane, 1, 4-diaminobutane and 1,6-diamino- hexane.

Further suitable aliphatic di-or poly-amines are dimeric, oligomeric or polymeric ethyleneimines.

Aromatic diamines are, for example, 1,2-diaminobenzene, 1, 3-diaminobenzene, 1,4-diamino- benzene, 1, 4-diaminonaphthalene, 1, 5-diaminonaphthalene, 1, 8-diaminonaphthalene, 2,5- diaminotoluene and 2, 4-diaminopyridine.

Araliphatic diamines are, for example, 4-aminobenzylamine, 4-(2-aminoethylpaniline and 1,4-bis (aminomethyl) benzene.

Suitable cycloaliphatic diamines are, inter alia, 1, 2-diaminocydohexane, 1, 3-diaminocydo- hexane, 1, 4-diaminocydohexane and isophoronediamine.

For preparation of the polyamines that can be used in the method according to the invention, the primary amino groups of the diamines are reacted, in accordance with methods known perse, with epoxides such as ethylene oxide, propylene oxide or 1, 2-epoxybutane, with chloroalkylamines such as, for example, 1-dimethylamino-2-chloropropane or 1-dimethyl- amino-2-chloroethane, with aromatic carboxylic acid chlorides such as benzoyl chloride or 4-aminobenzoyl chloride, with aromatic sulfonic acid chlorides such as benzene sulfochloride or 4-aminobenzene sulfochloride, or with reactive aromatic sulfonyl compounds such as, for example, 4- ine.

It is also possible first to add the said compounds containing at least two primary amino groups to an unsaturated aliphatic cyano compound such as, for example, acrylonitrile or methacrylonitrile and then to hydrogenate the intermediate obtained.

In the method according to the invention, preference is given to the use, as the polyamine, of a compound of formula (1) or (2)

wherein A is a divalent aliphatic, aromatic, araliphatic or cydoaliphatic radical, X1, X2, X3 and X4 are, each independently of the others, a linear or branched, divalent, aliphatic radical containing from 2 to 6 carbon atoms, and the radicals R, to R6 are, each independently of the others, hydrogen, C,-C6alkyl or amino-(C2-C6) alkyl, or the product of reaction of a compound of formula (1) or (2), wherein at least one of the radicals R, to R8 is hydrogen, with ethylene oxide, propylene oxide, 1,2-epoxybutane, a chloroalkylamine or an aromatic compound having at least one-COCI, aS03CI or-SOZ substituent wherein Z is vinyl, 2-chloroethyl or 2-sulfatoethyl.

Aliphatic radicals A in formulae (1) and (2) are, for example, ethylene, propylene, trimethylene, tetramethylene, hexamethylene, decamethylene or linear or branched alkylen interrupted by one or more-NH-,-N-alkyl-or-N-alkylene-NH2-groups.

Suitable aromatic radicals A in formulae (1) and (2) are, for example, 1, 2-phenylene, 1,3- phenylen, 1, 4-phenylene, naphthalene-1, 4-diyl, naphthalene-1, 5-diyl, naphthalene-1, 6-diyl and pyridine-2, 4-diyl.

Suitable aliphatic radicals Xi, X2, X3 and X4 in formulae (1) and (2) are, for example, ethylene, propylene, trimethylene, propane-1, 1-diyl or tetramethylene.

C,-C6Alkyl as one of the radicals R, to R8 can be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl or n-hexyl.

A in formula (1) or (2) is preferably an aliphatic radical.

Preferred polyamines are compounds of formula (1) or (2) wherein A is linear or branched C2-C10alkylene or linear or branched C4-C8oalkylene interrupted by one or more-NH-, - N-C,-Cealkyl-or-N-C,-C6alkylene-NH2-groups.

Special preference is given to compounds of formula (1) or (2) wherein A is ethylene, tetramethylene, hexamethylene or a group of formula (3) wherein x is a number from 1 to 20 and y is a number from 0 to 20, Y is a linear or branched C2-C6alkylene radical and R7 and Ra are, each independently of the other, hydrogen, Ci-Ce- alkyl or amino- alkyl.

R7 and Ra in formula (3) are preferably hydrogen, methyl or ethyl.

In the method according to the invention, preference is furthermore given to the use, as the polyamine, of a compound of formula (1) or (2) wherein R, to Ra are hydrogen or methyl.

In addition, preference is given to compounds of formula (1) or (2) wherein Xi, X2, X3 and X4 are ethylene, propylene, 1, 1-propanediyl or trimethylene.

In a further preferred embodiment of the method according to the invention, there is used, as the polyamine, the product of reaction of a compound of formula (1) or (2), wherein at least one of the radicals R, to R8 is hydrogen, with a compound of formula (4) to (9)

wherein Z is vinyl, 2-chloroethyl or 2-sulfatoethyl, w is 0 or 1, R11 and R12 are, each independently of the other, hydrogen or C,-C6alkyl, z is 0 or 1, Y is C2-C6alkylene, preferably ethylene, propylene, trimethylene or tetramethylene, R13 and R14 are, each independently of the other, halogen, -OR15, -NH2, -NHR15 or -NR15R16 wherein Ris and Rie are, each independently of the other, a linear or branched Cl-C, 2alkyl radical which is unsubstituted or which may be substituted by one or more hydroxyl, amino, sulfo or C6-C24aryl groups.

As the polyamine, special preference is given to the product of reaction of a compound of formula (1) or (2), wherein at least one of the radicals R, to R8 is hydrogen, with the compound of formula (10)

Especially preferred polyamines are the compounds of formulae (100) - (109)

The compounds of formulae (1) and (2) are known or can be prepared according to known methods, for example by reacting the diamine of formula H2N-A-NH2 with the appropriate aminoalkyl chlorides of formulae CI-X,-NRiR2, CI-X-NR3R4, CI-X-NR5R6 and CI-X4-NR7RB wherein A, X, to X4 and Ri to F ; Z8 are as defined hereinbefore.

The polyamines employed in the method according to the invention are advantageously used, irrespective of the liquor ratio, in an amount of from 0.01 to 15 % by weight, preferably from 0.1 to 10 % by weight and especially from 0.5 to 7 % by weight, based on the weight of the polyamide fibre material.

The treatment of the polyamide fibre material with the polyamine may be carried out after, during or, preferably, before the dyeing.

When the treatment of the polyamide fibre material with the polyamines is carried out during the dyeing process, the method according to the invention-is advantageously carried out by adding the polyamine to the dye liquor in the above-mentioned amount and dyeing the fibre material in the usual manner.

Preferably, however, the treatment of the polyamide fibre material with the polyamines is carried out before the dyeing. After the pre-treatment, the textile material is advantageously rinsed with water at RT (room temperature) or slightly elevated temperature.

Suitable polyamide fibre material includes natural polyamide fibre material, e. g. wool or silk, and synthetic polyamide fibre material, e. g. polyamide-6 or polyamide-6. 6, and fibre blends, e. g. wool/cellulose or polyamide/cellulose fibre blends, polyamide/wool fibre blends or polyamide/elastane fibre blends. The fibre material is preferably synthetic polyamide fibre material, especially microfibres.

The textile material can be used in any form, e. g. in the form of fibres, yarn, woven fabric or knitted fabric.

The treatment of the polyamide fibre material with the polyamines is preferably carried out in accordance with the exhaust process, in which case the liquor ratio can be selected from within a wide range and is, for example, from 1: 4 to 1: 100, preferably from 1: 5 to 1: 40 and especially from 1: 10 to 1: 40.

Special apparatus is not required. For example, customary dyeing apparatus, e. g. open baths, winch becks, jigs, or paddle, jet or circulation apparatus, may be used.

The procedure is advantageously carried out at a temperature of, for example, from 20 to 130°C, preferably from 50 to 120°C and especially from 60 to 100°C. The treatment time may be, for example, from 10 to 60 minutes and preferably from 15 to 40 minutes. The pH of the liquor is generally from 7 to 13, preferably from 8 to 12.5 and especially from 10 to 12.

The liquor can comprise, in addition to the adjuvant according to the invention, further customary additives, such as electrolytes, e. g. sodium chloride or sodium sulfate, dispersants and wetting agents, pH-regulators and antifoams.

Dyeing is carried out using, for example, anionic dyes or reactive dyes; any customary anionic dye or reactive dye, as described, for example, in Colour Index, 3rd edition (1971), is, suitable.

Examples of anionic dyes indude sulfo-group-containing monoazo, polyazo, metal complex azo, anthraquinone, phthalocyanine and formazan dyes.

The anionic dyes used in dyeing the polyamide fibre material are either in the form of their free sulfonic acids or, preferably, in the form of their salts.

The dyes used in the dyeing of the polyamide fibre material may comprise further additives, e. g. sodium chloride or dextrin.

Dyeing of the polyamide fibre material can be carried out in accordance with customary dyeing or printing methods, for example in accordance with the padding or exhaust process.

The dye liquors or printing pastes may comprise, in addition to water and the dyes, further

additives, for example wetting agents, antifoams, levelling agents or agents that influence the characteristics of the textile material, for example softeners, flame-retardants, or dirt-, water- and oil-repellents, and also water-softeners and natural or synthetic thickeners, for example alginates and cellulose ethers.

The amounts in which dyes are used in the dye baths can vary within wide limits depending on the required depth of shade; in general, amounts of from 0.01 to 15 % by weight, especially from 0.01 to 10 % by weight, based on the material to be dyed, have proved to be advantageous.

Dyeing with anionic dyes or reactive dyes is preferably carried out at a pH of from 1 to 8 and especially from 2 to 7. The liquor ratio can be selected from within a wide range, for example from 1: 3 to 1: 50, preferably from 1: 5 to 1: 30. Dyeing is preferably carried out at from 50 to 130°C and especially from 80 to 120°C.

Following the method according to the invention there are obtained dyeings of dyes, e. g. anionic dyes or reactive dyes, on polyamide fibre material, which dyeings exhibit a substantial improvement in terms of the depth of shade, without the fastness-to-washing or fastness-to-light properties being adversely affected.

The invention relates also to a textile adjuvant comprising an aqueous solution of a polyamine as defined hereinbefore.

The textile adjuvants according to the invention may comprise, as further additives, for example wetting agents, dispersants or pH-regulators.

The Examples that follow serve to illustrate the invention. The temperatures are given in degrees Celsius, parts are parts by weight, and percentages refer to percentages by weight, unless otherwise specified. Parts by weight relate to parts by volume in the same ratio as kilograms to litres.

I. Preparation Examples 1. 1.174. 3 g of pentaethylenehexamine, 5 drops of Triton B (40 % aqueous solution of benzyltrimethylammonium hydroxide) and 0.2 g of hydroquinone are introduced into a 350 ml sulfonating flask and heated at 40°C. Over the course of 70 minutes, 159.3 g of acrylonitrile are added dropwise. The reaction is exothermic and the temperature is maintained at 40- 45°C. After the addition, the reaction mixture is stirred for 90 minutes at 45°C and then for a further 3 hours at 70°C.

The product is then hydrogenated at 150°C and 80 bar in ethanol, using Raney nickel and ammonia as catalyst. After filtering off the catalyst, the ethanol is drawn off using a rotary evaporator.

275 g of a brown, clear, slightly viscous liquid are obtained.

1. 2.10. 9 g of pentaethylenehexamine and 20 g of water are introduced into a 100 ml sulfonating flask and heated at 40°C. Then, over the course of 40 minutes, a solution of 29.2 g of 2-chloro-1-dimethylaminopropane hydrochloride and 20 g of water is added dropwise. During the dropwise addition, a constant pH of 9.5 is maintained by adding 4N NaOH. After the addition is complete, stirring is carried out for a further 3 hours at 80°C and pH 9.5.

168 g of a dear, yellow, thin solution having an assay value of about 17 % are obtained.

1. 3.10. 9 g of pentaethylenehexamine and 20 g of water are introduced into a 100 ml sulfonating flask and heated at 40°C. Then, over the course of 40 minutes, a solution of 26.6 g of 1-chloro-2-dimethylaminoethane hydrochloride and 20 g of water is added dropwise. During the dropwise addition, a constant pH of 9.5 is maintained by adding 4N NaOH. After the addition is complete, stirring is carried out for a further 3 hours at 80°C and pH 9.5.

137 g of a clear, yellow, thin solution having an assay value of about 21 % are obtained.

1. 4. 86.1 g of polyethyleneimine having a molecular weight of 800 and 5 drops of Triton B (40 % aqueous solution of benzyltrimethylammonium hydroxide) are introduced into a 350 ml sulfonating flask and heated at 70°C. Over the course of 70 minutes, a solution of 58.5 g of 4-(2-sulfatoethylsulfonylfianiline and 80 g of water, neutralised to pH 4.5 and filtered, is added dropwise at 70°C. During the addition, the pH value drops. When pH 9.5 is reached,

the pH is kept constant by adding 4N NaOH. After stirring for 2 hours at 70°C and pH 9.5, a turbid solution is obtained. After cooling to RT (room temperature), the organic phase is separated off and collected.

A clear, brown, slightly viscous solution having an assay value of 40 % is obtained.

1. 5.34. 4 g of polyethyleneimine having a molecular weight of 600,49. 1 g of water and 3 drops of Triton B are introduced into a 350 ml sulfonating flask and heated to 70°C. After adding 58.5 g of 4- « 2-sulfatoethylsulfonylfianiline, the mixture is stirred at 70°C for 2 hours.

A turbid, brown solution of medium viscosity having an assay value of 50 % is obtained.

1. 6.6. 3 g of N, N, N', N'-tetrakis (3-aminopropyl)-1, 4-diaminobutane, 7.5 g of water and 1 drop of Triton B are introduced into a 100 ml sulfonating flask and heated to 70°C. After adding 5.8 g of 4- (2-sulfatoethylsulfonyl)-aniline, the mixture is stirred at 70°C for 2 hours.

A dear, brown solution having an assay value of 51 % is obtained.

1. 7.174. 3 g of pentaethylenehexamine, 5 drops of Triton B and 0.2 g of hydroquinone are introduced into a 350 ml sulfonating flask and heated at 40°C. Over the course of 70 minutes, 159.3 g of acrylonitrile are added dropwise. The reaction is exothermic and the temperature is maintained at 40-45°C. After the addition, the reaction mixture is stirred for 90 minutes at 45°C and then for a further 3 hours at 70°C.

The intermediate is then hydrogenated at 150°C and 80 bar in ethanol, using Raney nickel and ammonia as catalyst. After filtering off the catalyst, the ethanol is drawn off using a rotary evaporator.

21.5 g of the resulting product, 29 g of water and 5 drops of Triton B are introduced into a 100 ml sulfonating flask and heated to 70°C. After adding 29.2 g of 4-(2-sulfatoethylsulfonyl)- aniline, the mixture is stirred at 70°C for 2 hours.

A brown, turbid solution of medium viscosity having an assay value of 50 % is obtained.

1. 8. Example 1. 4. is repeated using 43 g of pentaethylenehexamine instead of polyethylene- imine.

A dear, brown solution having an assay value of 27 % is obtained.

1. 9. 4.61 g of cyanuric chloride, 25 g of water, 25 g of ice and 1 drop of a dispersant are introduced into a 350 ml sulfonating flask and stirred at 0°C for 30 minutes. Over the course

of about 35 minutes, a solution of 1.53 g of ethanolamine and 5.0 g of water is added dropwise so that the pH remains constant at 7.5. The mixture is stirred at 0°C for a further 90 minutes. A constant pH of 7.5 is maintained by adding 1 N NaOH.

There is then added a solution, neutralised to pH 4.0 and filtered, of 7.4 g of 4- (2-sulfato- ethylsulfonylpaniline and 20 g of water. The pH is kept constant at 5.0 and the temperature is slowly increased to 40°C. After about 6 hours, the reaction is complete.

A solution of 43.1 g of polyethyleneimine having a molecular weight of 800 and 20 g of water is then added. After reacting at pH 9.5 for 3 hours, the solution is filtered.

225 g of a dear solution having an assay value of 14 % are obtained.

1. 10.47. 9 g of diethylenetriamine, 5 drops of Triton B and 0.1 g of hydroquinone monomethyl ether are introduced into a 350 ml sulfonating flask and heated at 40°C. Over the course of 60 minutes, 98.5 g of acrylonitrile are added dropwise. The reaction is exothermic and the temperature is maintained at 40-45°C. After the addition, the reaction mixture is stirred for 90 minutes at 45°C, then for 90 minutes at 70°C and subsequently for a further 90 minutes at 90°C.

The product is then hydrogenated in ethanol at 70°C and 60 bar using Raney cobalt. After filtering off the Raney cobalt, the ethanol is drawn off using a rotary evaporator.

148 g of a dear, yellow liquid are obtained.

1 ! 9. 9 g of the resulting product, 47.5 g of water, 1 drop of Triton B ans 17. 4 g of 4-(2- sulfatoethylsulfonylpaniline are introduced into a 350 ml sulfonating flask and heated at 70°C. The reaction mixture is stirred at that temperature for 2 hours.

86.2 g of water are added; the product solution is cooled, filtered and collected.

167 g of a clear, red-brown liquid are obtained.

1. 11. 127 g of 1,6-diaminohexane, 5 drops of Triton B and 0.1 g of hydroquinone monomethyl ether are introduced into a 750 ml sulfonating flask and heated at 40°C. After the mixture has melted, 232 g of acrylonitrile are added dropwise over the course of 80 minutes. The reaction is exothermic and the temperature is maintained at 40-45°C. After the addition, the reaction mixture is stirred for 90 minutes at 45°C, then for 90 minutes at 70°C and subsequently for a further 90 minutes at 90°C.

The product is then hydrogenated in ethanol at 70°C and 60 bar using Raney cobalt. After filtering off the Raney cobalt, the ethanol is drawn off using a rotary evaporator.

323 g of a dear, yellow liquid are obtained.

20.6 g of the resulting product, 47.5 g of water, 1 drop of Triton B and 17.4 g of 4- (2- sulfatoethylsulfonylpaniline are introduced into a 350 mi sulfonating flask and heated at 70°C. The reaction mixture is stirred for 2 hours at that temperature.

100.2 g of water are added; the product solution is cooled, filtered and collected.

180 g of a dear, brown liquid are obtained.

II. Application Examples 11. 1. Pretreatment and dyeing of microfibres : (a) Pretreatment 5 g of polyamide microfibre fabric (PA-Meryl microfibre 5-3101) are immersed, at RT, in a liquor containing 0.25 g of the product of Preparation Example 1. 1 (5 % of active product, based on the fibre weight) and 45 g of water, adjusted to pH 11 using NaOH. The liquor is then heated to 98°C at a heating rate of 2°C/minute. Afler 30 minutes at 98°C, the liquor is cooled to 60°C at 3°C/minute.

After the pretreatment, the fabric is rinsed with water, first at 25°C and then at 50-60°C, and subsequently with dilute acetic acid (pH 6.0) at 25°C.

(b) Dyeing The pretreated fabric is immersed, at RT, in 50 g of a liquor adjusted to pH 3 using 80 % acetic acid and containing 8 % Eriofast Red 2B (Ciba Specialty Chemicals) and 1 g/litre of Tinovetin JUN (wetting agent, Ciba Specialty Chemicals). The liquor is then heated to 98°C at a heating rate of 2°C/minute. After 60 minutes at 98°C, the liquor is cooled to 60°C at 3°C/minute.

After the dyeing, the fabric is rinsed first at 50°C with water, then for 20 minutes at 70°C with aqueous Na2CO3 solution (1 gAHre), at 3040°C with water and finally at RT with dilute acetic acid (0.5 ml of 80 % acetic acid per litre) and again with water.

11. 2. Example 11. 1. is repeated using 1.50 g of the product of Preparation Example 1. 2.

11. 3. Example 11. 1. is repeated using 1.20 g of the product of Preparation Example 1. 3.

11. 4. Example 11. 1. is repeated using 0.62 g of the product of Preparation Example 1. 4.

11. 5. Example 11. 1. is repeated using 0.50 g of the product of Preparation Example 1. 5.

11. 6. Example 11. 1. is repeated using 0.30 g of the product of Preparation Example 1. 6.

11. 7. Example 11. 1. is repeated using 0.30 g of the product of Preparation Example 1. 7.

11. 8. Example 11. 1. is repeated using 0.95 g of the product of Preparation Example 1. 8.

11. 9. Example 11. 1. is repeated using 1.70 g of the product of Preparation Example 1. 9.

11. 10. Example 11. 1. is repeated using 0.25 g of the product of Preparation Example 1. 10.

11. 11. Example 11. 1. is repeated using 0.25 g of the product of Preparation Example 1. 11.

Test results : Dyeings having dark shades are obtained, without the fastness to washing and fastness to light being adversely affected.