DE849996C - Process for dyeing leather and animal skins with azo dyes - Google Patents

Description

Process for dyeing leather and animal skins with azo dyes Azo dyes are usually dipped or brushed on leather, mostly colored from a neutral or acid bath, depending on the dye composition low penetration depth or deep coloring of the leather is achieved. In the spray process one uses fuel-soluble azo dyes.

Some of these procedures are very time-consuming and some are sufficient also the fastness does not meet all requirements.

It has also been proposed to use azo dyes on leather in the `` '' ice produce that aminonaphtholsulfonic acids or coupling components which sulfonic acid amide groups contain, from soda-alkaline baths or those whose pH does not exceed 9, are applied to the leather and then with diazonium compounds on the Leather is made of the dye. This procedure is also not in practice was introduced, apparently because the two-bath application seemed cumbersome and deep coloring into the leather interior is difficult.

It has now been found that the production of azo dyes is based on Leather from the components is simpler and cheaper in terms of the degree of coloring can be achieved if the coupling component is in a caustic solution applies to the leather together with the diazo component in the form of its antidiazotate and then the antidiazotate in the couplable Converts diazonium compound, the coupling to the azo dye taking place.

While in the known method, coupling component and diazo component to be used one after the other, the depth of penetration is very limited, the caustic ones penetrate Solutions of the coupling components and antidiazotates, especially if you are dry Leather applies deeply into the leather and the dye is formed accordingly also in the inner zones of the leather.

The solutions of the mixtures of coupling components and antidiazotates In caustic alkalis, water-soluble solvents, Contains wetting agents, protective colloids and anti-reduction additives as well as salts. They can be applied to the leather by dipping, brushing or spraying will. The ones used to convert the antidiazotates into diazonium compounds Measures can consist of 'a short treatment with solutions of organic acids, like acetic acid, formic acid, tartaric acid, glycolic acid, citric acid, which also May contain salts, or acid salts, such as sodium acid sulfate, monosodium phosphate i.a. m. Acid fumes can also be painted over the treated leather, however, this method is time consuming as the treatment takes into account the Maintaining the leather quality in the cold or at moderate temperatures got to.

Treatment with acidic solutions can be done in the immersion process, as well as by brushing or spraying.

As coupling components in the sense of the above are the to understand products which are soluble in caustic solutions and which react with diazonium salts can combine to form azo dyes. Particularly good fastness properties are to be expected if such coupling components are used that the coupling steer into the ortho position to an oxy group, especially if they have a certain affinity to possess protein bodies. Oxynaphthoylaminoaryls and alkyls, aroyls or oxynaphthoylaminoaryls may be mentioned Alkoyl compounds of aminonaphthols, carboxylic acid arylamides of oxycarbazole, oxydiphenylene oxide, Oxynaphthocarbazoles, oxythiodiphenyls, oxyanthracene, oxybenzoic acid and the Cresotinic acid, acetoacetyl, benzoylacetyl, terephthaloylacetylarylamides. Contain such compounds have a sulfonic acid or carboxylic acid group in their molecule, so dyeings of increased rub fastness are obtained.

If you apply the mixtures of coupling components locally on the leather on by stencil or relief printing, brush or spray printing, this allows Process also to produce patterns on the leather.

The method also enables the backs of fur skins to be colored without coloring the hair.

EXAMPLE i Leather tanned with a vegetable combination of chromium is treated for one minute with an aqueous solution which contains per liter: 15 g of 2 ', 3'-oxynaphthoyl-i-aminobenzo-3-carboxylic acid, 25 g of a 45% alkaline setting of the antidiazotate i-Amino-2-methyl-4-chlorobenzene, 35 g sodium hydroxide solution 38 ° B6, 50 g spirit, 30 g castor oil sulfonic acid sodium 50%, 10 g sodium chromate, 835 ccm water.

It is then squeezed off and treated immediately or after a few hours of storage for 30 seconds with a 40 ° warm solution of 50 g of glacial acetic acid and 100 g of Glauber's salt per liter of water. After half an hour of storage, it is rinsed and dried. A red coloration is obtained which is colored very well in section.

You can also brush the solution onto the dry leather using a brush method or spray it on with a spray gun. In the latter case, especially when it comes to the production of patterns using a template, the solution is expediently thickened a little with tragacanth thickening. Example 2 Chrome-tanned leather is coated on both sides with a solution of 15 g of 2 ', 3'-oxynaphthoylamino-2-methoxybenzene, 25 g of an alkaline 55% solution of sodium antidiazotate from i-amino-2-methoxy-5-chlorobenzene, 25 ccm Sodium hydroxide solution 38 ° B6, 30 g of castor oil sulphonic acid sodium 50 %, 50 g of spirit, 10 g of sodium chromate, 865 cc of water.

The coating solution is allowed to penetrate for a short time and then treated with a solution of so g of glacial acetic acid and 100 g of sodium chloride per liter of water by brushing on. A red color is obtained. Example 3 Vegetable tanned leather is treated for one minute with a solution of 10 g of 4- (2'-nitrobenzolazo) -i-amino-7-oxynaphthalene, 25 g of an alkaline 55% setting of the antidiazotate from i-amino-2- methoxy-5-chlorobenzene, 30 g sodium hydroxide solution 38 ° B6, 30 g sodium castor oil sulfonic acid, 50 g spirit, 10 g sodium chromate, 865 g water.

It is squeezed off and treated for 1/2 minute with so g of glacial acetic acid and 100 g of table salt per liter of water, left for a while and rinsed and dried. A purple-brown color is obtained. Example 4 A trimmed sheepskin that has been sanded on the leather side is brushed on the leather side with a solution of so g of a dye preparation, molar amounts of 2 ', 3'-oxynaphthoyl-i-amino-2-methylbenzene and antidiazotate from i-amino-5- Containing trifluoromethylethylsulfonylbenzene, 30 g sodium hydroxide solution 38 ° B6, 50 g spirit, 30 g castor oil sulfonic acid sodium 50%, 10 g sodium chromate, 50 g tragacanth thickening 3o: 1000, 780 g water.

The dye solution is allowed to soak in and a 35 ° solution of so g of glacial acetic acid and 100 g of table salt per liter is applied. After a short exposure, rinse in water, dry and purify as usual. Table of the shades obtained on leather No. I coupling component antidiazotate color 1 2 ', 3'-oxynaphthoylamino-2-methoxybenzene i-amino-2-methyl-4-chlorobenzene red 2 2 ', 3'-oxynaphthoylaminonaphthalene similarly bluish-tinted red 3 2 ', 3'-oxycarbazole carboylamino-4-chloro- benzene also brown 4 i-acetoacetylamino-4-chloro-2,5-dimeth- oxybenzene like yellow 5 2 ', @' - oxynaphthoyl-i-amino-2-methyl- 4-methoxybenzene like red 6 2 ', 3'-oxynaphthoyl-i-amino-2-methyl- benzene-5-sulfonic acid similarly red 2 ', 3'-oxynaphthoyl-i-amino-2-methyl- benzene i-amino-2-methyl-4-chlorobenzene red 8 2 ', 3'-oxynaphthoyl-i-amino-2-ethoxy- benzene i-amino-2-methyl-5-chlorobenzene scarlet red 2 ', 3'-oxynaphthoylamino-2, 5-dimethoxy- benzene i-amino-2, 5-dichlorobenzene brown-red 10 2 ', 3'-oxynaphthoyl-i-amino-2-ethoxy- benzene like red-orange 11 2 ', 3'-oxynaphthoyl-i-amino-2-methoxy- benzene and scarlet red 12 2 ', 3'-Oxynaphthoyl-i-aminobenzene like red 13 2 ', 3'-oxycarbazole carboyl-i-amino- 4-chlorobenzene also brown 14 4,4'-diacetoacetoylamino-3, 3'-dimethyl- diphenyl like yellow 15 i-Benzoylacetylamino-4-benzoylamino- 2, 5-dimethoxybenzene i-amino-2-methoxy-5-chlorobenzene yellow 16 2 ', 3'-Oxynaphthoyl-i-aminonaphthalene similarly bluish-tinted red 17 2 ', 3'-oxynaphthoyl-i-aminonaphthalene- 4-sulfonic acid similarly bluish-tinted red 18 2 ', 3'-oxynaphthoyl-i-aminobenzene- 3-carboxylic acid like red 19 2 ', 3'-oxynaphthoyl-i-amino-2-methyl- benzene-5-sulfonic acid similarly red 20 2 ', 3'-Oxynaphthoyl-i-amino-3-nitrobenzene, like bluish-tinted red 21 2 ', 3'-Oxycarbazolcarboyl-i-amino-4-chloro- benzene also brown 22 2 ', 3'-Oxynaphthoylaminobenzene i-Amino-2-chloro-5-trifluoromethylbenzene red orange 23 2 ', 3'-Oxynaphthoylamino-2-methoxybenzene like red-orange 24 2 ', 3'-Oxynaphthoylaminobenzene 4, 4'-Diamino-3, 3'-dimethoxydiphenyl blue 25 2 ', 3'-Oxynaphthoylaminobenzene i-Amino-2-chloro-4-nitrobenzene red 26 2 ', 3'-Oxynaphthoylaminobenzene i-Amino-2-nitro-4-methylbenzene red 2-7 2 ', 3'-Oxynaphthoyl-i-aminonaphthalene i-Amino-2-methoxy-4-nitrobenzene bluish-tinted red 28 2 ', 3'-oxycarbazolecarboylamino-4-chloro- benzene i-amino-3-chlorobenzene olive brown

Claims (1)

PATENT CLAIM: `` 'Learn about dyeing leather and animal skins with azo dyes, characterized in that the material to be dyed with caustic alkaline Solutions is treated that contain coupling components in addition to antidiazotates and is then post-treated with acidic agents for the purpose of dye formation.