EP0432597B1 - Process for dyeing polyamide substrates - Google Patents

Description

The present invention relates to an improved process for dyeing polyamide substrates from aqueous baths with suitable dyes and with copper complexes as light stabilizers for the colored polyamide.

The invention further relates to dye formulations which contain a copper complex of an organic N-nitrosohydroxylamine as a light stabilizer for the colored polyamide.

It is well known that colored polyamide loses lightfastness due to the catalytic influence of the dye, i.e. it is subject to chemical changes under the influence of light and especially light and heat, which deteriorate the mechanical and thermal properties and also cause undesirable discoloration.

To remedy this disadvantage, lightfastness stabilizers have therefore been used in the coloring, which are primarily copper complexes, e.g. of salicylaldehydes (EP-A 252 368), salicyloximes (EP-A 113 856 and EP-A 162 811) and water-soluble azo dyes (EP-A 255 481) and of hydroxamic acids (DE-A 3 326 640).

However, the uptake of these complexes leaves something to be desired, i.e. for rapid dyeing, the concentration in the dye bath must be chosen higher than the amount required, and moreover they have too strong their own color, so that they shift the color tone and brilliantly tarnish the dyeing, particularly in the case of brilliant dyeings.

The object of the invention was therefore to remedy these disadvantages.

Accordingly, a process for dyeing polyamide substrates from aqueous baths with suitable dyes and with copper complexes as light stabilizers for the colored polyamide has been found, which is characterized in that the copper complexes used are those of organic N-nitrosohydroxylamines.

entsprechen und in denen die Reste R aliphatische, cycloaliphatische, araliphatische oder aromatische organische Gruppen bedeuten, können sich prinzipiell von beliebigen organischen N-Nitrosohydroxylaminen ableiten.The copper complexes to be used according to the invention, which have the general structure I

correspond and in which the radicals R are aliphatic, cycloaliphatic, araliphatic or aromatic organic groups, can in principle be derived from any organic N-nitrosohydroxylamines.

• C₁-C₂₀-Alkylgruppen, vorzugsweise C₁-C₁₀-Alkylgruppen, darunter vorzugsweise 2-Ethylhexyl sowie C₁-C₄-Alkylgruppen wie Methyl, Ethyl, n-Propyl, iso-Propyl, n-Butyl und iso-Butyl;
• C₃-C₂₀-Alkenylgruppen, vorzugsweise C₃-C₆-Alkenylgruppen wie Propenyl, Butenyl, Pentenyl, Hexenyl, sowie vor allem Oleyl;
• C₇-C₁₂-Arylalkylgruppen, vorzugsweise Benzyl und Phenylethyl;
• C₅-C₁₂-Cycloalkylgruppen, vorzugsweise C₅-C₇-Cycloalkylgruppen wie Cyclopentyl, Cycloheptyl und besonders Cyclohexyl;
• Arylgruppen wie vorzugsweise Phenyl.

For economic reasons, however, those complexes I are preferred in which the radicals R have the following meaning:

• C₁-C₂₀ alkyl groups, preferably C₁-C₁₀ alkyl groups, including preferably 2-ethylhexyl and C₁-C₄ alkyl groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl and iso-butyl;
• C₃-C₂₀ alkenyl groups, preferably C₃-C₆ alkenyl groups such as propenyl, butenyl, pentenyl, hexenyl, and especially oleyl;
• C₇-C₁₂ arylalkyl groups, preferably benzyl and phenylethyl;
• C₅-C₁₂ cycloalkyl groups, preferably C₅-C₇ cycloalkyl groups such as cyclopentyl, cycloheptyl and especially cyclohexyl;
• Aryl groups such as preferably phenyl.

The cycloalkyl and aryl groups can in turn carry one to three substituents.

• Vorzugsweise C₁-C₁₂-Alkylgruppen, C₁-C₁₂-Alkoxygruppen, C₂-C₈-Alkenylgruppen, Aminogruppen und Chlor;
• Weiterhin Fluor, Brom, die Sulfonsäuregruppe und Reste der Formeln -CO-O-R¹ und -SO₂-R¹, und
• außerdem Hydroxy, Nitro, Nitroso und Reste der Formeln -N(R¹)R² und -NH-CO-R¹,

wobei R¹ und R² C₁-C₁₂-Alkylgruppen, Phenylgruppen oder C₇-C₁₂-Phenylalkylgruppen bezeichnen.As substituents on the cycloalkyl radicals come C₁-C₄ alkyl groups. Preferred alkylcycloalkyl groups are 4-methyl and 4-tert-butylcyclohexyl. The following substituents should be emphasized for the aryl groups:

• Preferably C₁-C₁₂ alkyl groups, C₁-C₁₂ alkoxy groups, C₂-C₈ alkenyl groups, amino groups and chlorine;
• Furthermore, fluorine, bromine, the sulfonic acid group and radicals of the formulas -CO-O-R¹ and -SO₂-R¹, and
• also hydroxy, nitro, nitroso and radicals of the formulas -N (R¹) R² and -NH-CO-R¹,

wherein R¹ and R² denote C₁-C₁₂ alkyl groups, phenyl groups or C₇-C₁₂ phenylalkyl groups.

The following should be emphasized as compounds I with substituted phenyl groups:
Tolyl, 2,3- or 4-chlorophenyl, 2,3- or 4-bromophenyl, 2,3- or 4-fluorophenyl, 2,3- or 4-ethylphenyl, 2,3- or 4-propylphenyl, 2,3 - or 4-iso-propylphenyl, 2,3- or 4-dodecylphenyl, 2,3- or 4-methoxyphenyl, 2,3- or 4-ethoxyphenyl, 2,3- or 4-propoxyphenyl, 2,3- or 4 -Butoxyphenyl, 4-nitrosophenyl, 4-hydroxyphenyl, 4-dimethylaminophenyl, 4-diethylaminophenyl, 4-aminophenyl, phenylsulfonylphenyl, methyloxycarbonyl, ethyloxycarbonyl, propyloxycarbonyl, acetylamino, propionylamino, butanoylamino and pentanoylamino.

The N-nitrosohydroxylamines on which the complexes are based are known or can be obtained in a known manner, e.g. by the action of nitrosating agents such as alkali metal nitrites on N-monosubstituted hydroxylamines (DE-A 10 19 657). The same applies to the production of the complexes.

Since the impairment of the lightfastness of the polyamides practically does not depend on the chemical nature of the dye, all those which are suitable for dyeing polyamides are suitable as dyes, including in particular dyes with acidic groups and disperse dyes.

Suitable dyes are azo and anthraquinone dyes, their metal complexes and also other metal complex dyes.

Among the azo dyes, mono- and bisazo dyes of benzene-azo-naphthalene, benzene-azo-1-phenylpyrazol-5-one, benzene-azo-benzene, naphthalene-azo-benzene, benzene-azo-aminonaphthalene are particularly suitable. , Naphthalene-azo-naphthalene, naphthalene-azo-1-phenylpyrazol-5-one, benzene-azo-pyridone, benzene-azo-aminopyridine, naphthalene-azo-pyridone, naphthalene-azo-aminopyridine and the stilbene -azo-benzene series.

Further dyes of this type can be found in the relevant specialist literature Color Index and K. Venkataraman "The Chemistry of Synthetic Dyes", Vol. VI, Academic Press, New York, London, 1972. Those from the class of anthraquinone dyes are described in K. Venkataraman, Vol. II, Academic Press, New York, 1952.

Particularly suitable disperse dyes are metal complex dyes, for example 1: 1 or preferably 1: 2 complexes of metallized azo, azomethine and phthalocyanine dyes.

Azo and azomethine dyes preferentially complex chromium or cobalt, phthalocyanines especially copper and nickel. Examples of the latter class of dyes are described in F.H. Moser, D.L. Thomas: The Phthalocyanines ", Vol. II, CRC Press, Boca Raton, Florida 1983.

Mixtures of different dyes are of course also suitable.

The process according to the invention is suitable for dyeing any polyamides, e.g. also natural polyamides such as wool and silk, but is of particular practical importance for dyeing synthetic polyamides such as nylon 6, nylon 6.6 and nylon 12 or materials containing these polyamides.

In principle, the substrates can be of any shape - for example injection molded articles, foils, tapes and fibers, but primarily fiber structures such as yarns, nonwovens and mainly textiles come into consideration.

The dyeing process is carried out under the conditions recommended for the respective dyes, as usual, from an aqueous bath, so that detailed explanations for this are unnecessary.

If it is water-insoluble dyes or copper complexes, it is advisable to use a dispersant.

The amount of copper complexes to be used according to the invention, in the case of polyamide textile goods, is generally between 0.01 and 2% by weight of copper, depending on the type of fabric and the amount of dye applied, based on the amount of the polyamide content in the textile goods. The concentration of the complex in the dyebath depends on this amount, which is expediently dimensioned in such a way that the used dyebath contains only 0.001 to 1% by weight of copper in the form of the complexes because of the excellent absorption capacity. In the case of other substrates, the effective amounts of dyes and complexes can be determined by means of a few preliminary tests.

The copper complexes are normally finished at the same time as the dyeing process, but it is also possible to apply the complexes to the substrate from a separate bath before or after the dyeing.

In the case of simultaneous application, it is expedient to provide ready-to-use dye preparations which contain the dyes, optionally dispersants and other customary auxiliaries and the complexes.

The process according to the invention is of great importance for the dyeing of textiles made of polyamides, which are not only exposed to light to a special degree but also to heat, which are primarily fabrics for the seats and interior linings of cars. The lower intrinsic color of the complexes enables the fabrics to be colored in clearer shades than before.

example 1

0,5 g

des dunkelblauen 1:2-Chrom-Komplex-Farbstoffes der Colour Index Nr. 15707

0,05 g

des grünen Anthrachinon-Farbstoffes der Colour Index Nr. 61570

0,45 g

des blauen Anthrachinon-Farbstoffes N,N'-Bis(4-amino-3-sulfo-anthrachinonyl)-4,4'-diaminodiphenylmethan

0,5 g

Dispergiermittel (Oleylamin, oxethyliert mit 12 mol Ethylenoxid) und

0,05 g

(= 0,009 g Cu) des Kupferkomplexes von N-Nitroso-cyclohexylhydroxylamin (I, R = Cyclohexyl)

enthielt.100 g of a yarn made of nylon 6.6 were dyed for 60 minutes at boiling temperature in 2 l of an aqueous liquor which had been brought to pH 5 with acetic acid and which

0.5 g

of the dark blue 1: 2 chromium complex dye of Color Index No. 15707

0.05 g

of the green anthraquinone dye, Color Index No. 61570

0.45 g

of the blue anthraquinone dye N, N'-bis (4-amino-3-sulfo-anthraquinonyl) -4,4'-diaminodiphenylmethane

0.5 g

Dispersant (oleylamine, oxyethylated with 12 mol ethylene oxide) and

0.05 g

(= 0.009 g Cu) of the copper complex of N-nitroso-cyclohexylhydroxylamine (I, R = cyclohexyl)

contained.

The yarn dyed in this way is characterized by high light fastness and brilliant coloring.

Example 2

0,7 g

des gelben 1:2-Chrom-Komplex-Farbstoffes der Formel

0,3 g

des rotvioletten 1:2-Chrom-Komplex-Azofarbstoffes der Colour Index Nr. 18762 und

0,5 g

Dispergiermittel (Oleylamin, oxethyliert mit 12 mol Ethylenoxid)

enthielt.100 g of a nylon 6.6 fabric were dyed for 40 minutes at a temperature of 115 ° C. in an autoclave with a liquor adjusted to pH 4.5

0.7 g

of the yellow 1: 2 chromium complex dye of the formula

0.3 g

of the red-violet 1: 2 chromium complex azo dye of Color Index No. 18762 and

0.5 g

Dispersant (oleylamine, oxyethylated with 12 mol ethylene oxide)

contained.

After subsequent rinsing and drying, the fabric was impregnated with a liquor which contained 1 g (= 0.188 g Cu) of the copper complex of N-nitroso-phenylhydroxylamine (I, R = phenyl) per liter of water.

The orange-brown dyeing obtained in this way showed a significantly improved light fastness in accordance with the fakrotest DIN 75 202 compared to a dyeing which had not been post-treated.

Example 3

0,04 g

des braunen 1:2-Chrom-Mischkomplex-Azofarbstoffes der Formel

0,04 g

des olivfarbenen 1:2-Cobalt-Komplex-Azofarbstoffes der Formel

0,5 g

Dispergiermittel (Oleylamin, oxethyliert mit 12 mol Ethylenoxid) und

0,1 g

(= 0,018 g Cu) des Kupferkomplexes von N-Nitroso-cyclohexylhydroxylamin (I, R = Cyclohexyl)

enthielt.100 g of a flake made of nylon 6 were dyed for 60 minutes at boiling temperature in 2 l of an aqueous liquor which had been adjusted to pH 6 with monosodium phosphate and acetic acid

0.04 g

of the brown 1: 2 chromium mixed complex azo dye of the formula

0.04 g

of the olive-colored 1: 2 cobalt complex azo dye of the formula

0.5 g

Dispersant (oleylamine, oxyethylated with 12 mol ethylene oxide) and

0.1 g

(= 0.018 g Cu) of the copper complex of N-nitroso-cyclohexylhydroxylamine (I, R = cyclohexyl)

contained.

The gray color produced in this way showed, according to the facotest DIN 75 202, a significantly improved light fastness compared to a corresponding color without the addition of the copper complex.

Claims (5)

1. A process for dyeing a polyamide substrate from an aqueous bath with a suitable dye and with a copper complex.as light stabilizer for the dyed polyamide, which comprises using the copper complex of an organic N-nitrosohydroxylamine.
2. A process as claimed in claim 1, wherein the copper complex used has the formula I

   

   in which each R is C₁-C₂₀-alkyl, C₃-C₂₀-alkenyl, C₇-C₁₂-aralkyl, C₅-C₁₂-cycloalkyl or aryl, of which the cycloalkyl may be substituted by up to 3 C₁-C₄-alkyl groups and the aryl by up to 3 C₁-C₁₂-alkyl groups, C₁-C₁₂-alkoxy groups, C₂-C₈-alkenyl groups, or chlorine or amino radicals.
3. A process as claimed in claim 2, wherein R is phenyl or cyclohexyl.
4. A process as claimed in any of claims 1 to 3, wherein the polyamide substrate is a sheetlike structure consisting of or containing polyamide fiber material.
5. A dye formulation for dyeing a polyamide substrate, which contains a copper complex of an organic N-nitrosohydroxylamine as light stabilizer for the dyed polyamide.