EP0372536B1 - One-phase process for producing prints using reactive dyes besides azoic developing dyes on alkali-pre-impregnated textiles - Google Patents

Description

The present invention relates to a single-phase process for producing prints on textiles previously primed with coupling components under alkaline conditions, cellulose-containing or textiles consisting exclusively of cellulose fibers by separate overprinting with reactive dyes in addition to primary aromatic amines with addition of sodium nitrite and in the presence of acid or acid-providing substances Diazotizing produced immediately couplable diazonium compounds with simultaneous development of water-insoluble azo dyes as a result of spontaneous coupling, and fixation of the reactive dyes which takes place after drying of these prints by steaming.

For dyeing the textiles, the generic chemical compounds listed in the Color Index, 3rd edition 1971 as "C.I. Azoic Coupling Component" (coupling component) and as "C.I. Azoic Diazo Component" (diazo component) are suitable.

The printing of textiles primed with coupling components - hereinafter referred to briefly as "naphthols" - with the diazo components, for example so-called fast dye salts or diazotized fast dye bases, has been known for a long time and is generally carried out in practice according to this principle: for this purpose the textiles are shaped padded with an alkaline solution of naphthol and dried. This pre-primer is then printed either using commercially available, stabilized diazonium compounds or by means of the free diazonium compounds prepared directly from primary aromatic amines by a diazotization process. In both cases, dye coupling on the fiber creates the azo dye - also common as a development dye - at the printed areas of the textile.

The primary aromatic amines are conventionally diazotized in a strongly acidic medium, generally with the aid of hydrochloric acid. In order to ensure the envisaged dye coupling as quickly and as completely as possible, the strongly acidic diazonium salt solution must be buffered to pH values around 3 to 4. At the same time, it must be ensured that there is still sufficient acid capacity to neutralize the alkali applied together with the naphthol. The diazonium salt solution thus set is then thickened for printing. The dye formation itself takes place close to the neutral point.

DE-A-28 50 901 describes a simplified process for preparing printing pastes with real dye bases capable of coupling, in which the diazotization of the amine is not carried out in solution, as is customary, but rather directly in the thickener, namely by stirring two together thickened batches, one with the acid required for diazotization, the other with the amine to be diazotized and sodium nitrite in the amounts necessary for the diazotization.

It is also known that, in addition to the diazo component (s), textiles pretreated with a coupling component in this way can also be used to separately print reactive dyes, in which case it would be theoretically possible to use the excess To use alkali of the naphthol primer at the same time to fix the reactive dyes.

However, such a project fails when using the previously customary diazotization methods because volatile acids are released and escape, both during the drying process of the printed goods and during the subsequent steaming in the course of dye fixation, which uncontrollably partially controls the alkali necessary for fixing the reactive dyes neutralize. The fixation of the reactive dyes then proceeds unevenly and in some areas not at all or only incompletely.

In the known printing methods, the presence or the formation of these volatile acids stems from the dulling (buffering) of the diazonium salt solutions, generally with a mixture of Na acetate / acetic acid, which is stirred into the pressure thickener.

The use of increased amounts of alkali in the form of sodium bicarbonate or soda, added directly to the reactive printing paste, often does not help. In addition, there is the problem of the often low stability of reactive printing pastes which have already been made alkaline.

One has therefore abandoned this single-phase procedure for fixing the reactive dyes by steaming and fixes the reactive dyes in such a case in two phases by passing the printed goods after the coupling process to the development of the azo dyes again through an alkali-containing bath and only then dampens, or that you choose a different, two-phase fixing method for reactive dyes.

The invention defined below is based on the object of creating a single-phase printing process of reactive dyes in addition to azo developing dyes (i.e. the related diazo components) on goods which have been alkaline-primed beforehand with coupling components and which does not have the disadvantages of the techniques known in this field.

This object is achieved in that, in the diazotization of the printed amines as the sole acidic agent, an acid which is neither volatile during the drying process nor in the steam during the fixing operation and, if appropriate, only water-soluble salts of such acids are used to buffer the printing pastes with the diazonium compounds.

The free amine can be diazotized both in the solution or dispersion and in accordance with the method according to DE-A-28 50 901 in the thickening.

Because of the easier and faster course of the diazotization, the primary aromatic amines are advantageously used in the form of finely divided dispersions, as described in DE-A-23 46 612 or DE-A-24 49 782.

Suitable diazotizable amines (also aminoazo dyes) are in principle all those which are suitable for the customary ice color technique. Preferred amines are mentioned in DE-A-23 46 612 and DE-A-24 49 782. It also describes how these amines can be converted into suitable finely divided dispersions.

Modified or degraded locust bean gum or guar products, if appropriate also cellulose or starch ethers or plant mucilage, are expediently used as thickeners for preparing the printing inks.

As acidic chemicals which are not volatile in steam under the process conditions, medium to weak, inorganic or organic acids are suitable for carrying out the diazotization. Low molecular weight aliphatic carboxylic acids such as glycolic acid, citric acid, tartaric acid or oxalic acid, but preferably also phosphoric acid, are used in amounts of 20 to 80 g / kg base color.

In certain cases, however, it can also be diazotized with strong acids, such as sulfuric acid or, in particular, hydrochloric acid, if the amine requires such a diazotization. The blunting then has to be done with neutral or alkaline salts of acids that are not volatile in water vapor, for example with tertiary or secondary sodium salts of phosphoric acid, such as tri- or disodium phosphate, or with corresponding buffer mixtures.

Suitable coupling components for priming the cellulosic materials are alkaline solutions of those compounds which couple in the vicinity of a hydroxyl group. Such compounds are listed in DE-A-28 50 901.

In addition to the diazo components, neutral, thickened solutions of reactive dyes are printed according to the invention in question. In principle, all organic colorants mentioned in the Color Index, 3rd edition 1971 and supplements 1975, 1982 and 1987 under the name "C.I. Reactive Dyes" can be used without restriction.

These reactive dyes are, according to the process, with the body-poor and commercially available for this class of dyes alkali-insensitive thickeners, such as thickened alginate.

According to this invention, the two process variants are therefore carried out as follows:

a) Diazotization in the solution

The fabric to be dyed is first padded and dried with the coupling component, which is dissolved in an alkaline manner according to the customary instructions. The amines provided as diazo components are also diazotized according to the instructions, but instead of the hydrochloric acid normally used otherwise, equivalent amounts of a medium to weak, non-steam-volatile organic or inorganic acid are used here. If, in the case of a primer that only couples well in a narrow pH range, an exact adjustment to the pH value that is conducive to coupling is required, the solutions of the diazonium compounds used for dye development in such a case become weaker with an alkaline or neutral salt , non-volatile acidity adjusted. The diazonium salt solutions obtained in this way are then thickened and printed.

The reactive dyes used for printing are dissolved in water until neutral, this solution is thickened and then printed in the same operation next to the diazo components.

The printing of the diazonium compounds on the naphthol-primed product immediately gives the development dye.

To fix the reactive dyes, the goods must be steamed for 6 to 8 minutes at 100 ° to 105 ° C after printing.

The prints are treated as usual.

b) diazotization in the thickening

The printing material is primed with the coupling component as in variant a). The diazotization of the amines provided as the diazo component takes place in accordance with the specification in DE-A-28 50 901 by stirring two thickenings, one containing the non-volatile acid, the other the amine and sodium nitrite. The reactive dyes are separately dissolved and thickened in water as in variant a).

After the printing of both printing pastes side by side on the primed goods, the textile material for fixing the reactive dyes is steamed and post-treated as in variant a).

The following procedure has proven to be more practical:
The thickened nitrite solution is initially introduced and the corresponding finely divided amine is first introduced, the mixture is stirred and then the acid required for the diazotization, usually dilute phosphoric acid, is added and finally the printing ink prepared in this simplified manner is thoroughly stirred with the diazonium compound .

The following examples are intended to explain the claimed process, without restricting it in the stated ways.

The dyes or dye precursors are used in a commercial presentation, so that quantities refer to such commercial products.

example 1

A cotton fabric is washed with an aqueous solution containing 20 g of Azoic Coupling Component 2 with the CI no. 37505 (2-hydroxy-3-naphthoylamino-benzene) and 25 g sodium hydroxide solution (32.5%) in liters, primed and dried. Then a printing paste is printed on the goods treated in this way, the production of which proceeds as follows: Root approach I: In 500 g a 5% aqueous solution of locust bean gum as a thickener 16-18 g Sodium nitrite incorporated. By filling up with 484-482 g Water is on 1,000 g completed. Root approach II: In 500 g the same thickening as in master batch I. 60 g Phosphoric acid (85%) stirred in and by filling with 440 g Water is on 1,000 g completed.
To make the printing ink 300 g of master batch I, 15 g a 60% aqueous dispersion of Azoic Diazo Component 11 with the CI no. 37085 (4-chloro-o-toluidine) and 300 g of master record II and 385 g Water to complete 1000 g added.
In addition to this printing paste, another printing paste is made 30 g of the dye Reactive Blue 19 with the CI no. 61200, 500 g a neutral, 4% alginate thickening, 50 g Urea and 420 g water 1000 g printed on the primer.

After printing, the fabric is dried, steamed at 102 ° C. for 8 minutes to fix the dye, rinsed with water, hot soaped and finally rinsed again with water.

A deep red print with good fastness properties based on the development dye is obtained on the goods in addition to a real, clear blue based on the reactive dye.

Example 2

16 g/l

von Azoic Coupling Component 2 mit der C.I.-Nr. 37505 (2-Hydroxy-3-naphthoylamino-benzol),

hergestellt nach der Vorschrift aus der Firmenbroschüre "Naphtol AS Anwendungsvorschriften" Hoe 4026 der Farbwerke Hoechst Aktiengesellschaft, Frankfurt/Main und trocknet das so behandelte Textilgut.A cotton fabric is primed with the alkaline solution of

16 g / l

by Azoic Coupling Component 2 with the CI no. 37505 (2-hydroxy-3-naphthoylamino-benzene),

produced according to the regulation from the company brochure "Naphtol AS application instructions" Hoe 4026 from Farbwerke Hoechst Aktiengesellschaft, Frankfurt / Main and dries the textile goods treated in this way.

12 g/kg

von Azoic Diazo Component 34 mit der C.I.-Nr. 37100 (o-Chloranilin-hydrochlorid)

mittels Natriumnitrit und Salzsäure. Das Abstumpfen der Diazoniumsalzlösung erfolgt jedoch in diesem Fall nicht mit Natriumacetat, sondern hier mit

30 g/kg

Dinatriumphosphat.

Diese Lösung wird nunmehr durch Vermischung mit 600 g einer Johannisbrot-Kernmehlether-Verdickung und x g Wasser zu 1000 g Druckpaste verdickt.
Des weiteren stellt man eine zweite Druckpaste her aus 40 g des Farbstoffes Reactive Yellow 17 mit der C.I.-Nr. 18852, 50 g Harnstoff, 700 g einer neutralen, 6%igen Alginatverdickung und 210 g Wasser 1000 g. Diazotization is also carried out according to the above-mentioned application instructions

12 g / kg

by Azoic Diazo Component 34 with the CI no. 37100 (o-chloroaniline hydrochloride)

using sodium nitrite and hydrochloric acid. In this case, however, the diazonium salt solution is not blunted with sodium acetate, but here with

30 g / kg

Disodium phosphate.

This solution is now mixed with 600 g a locust bean gum thickener and xg Water too 1000 g Printing paste thickened.
A second printing paste is also produced 40 g of the dye Reactive Yellow 17 with the CI no. 18852, 50 g Urea, 700 g a neutral, 6% alginate thickening and 210 g water 1000 g.

The two printing pastes are printed side by side on the primed fabric and this is then dried at 100 ° C.

Now the fabric is steamed for 6 minutes at 105 ° C for dye fixation, then rinsed with water, neutralized and neutral soaped. A gold-yellow reactive print is obtained on the goods, in addition to a red print of the development dye.

If, in the above example, the diazonium salt solution is blunted with sodium acetate, the procedure is otherwise the same, an incomplete and uneven fixation of the reactive dye is obtained, especially in the vicinity of printing paste with the diazotized amine which is simultaneously printed on, to form the development dye.

Example 3

A cotton fabric is primed as described in Example 2 and dried. For the coupling of the primer with a diazonium compound, a printing ink is prepared separately as follows: In 814 g a locust bean gum thickener (medium viscosity adjusted) containing 6 g Sodium nitrite 20 g by Azoic Diazo Component 34 with the CI no. 37100 (4-nitro-o-toluidine) in finely divided, liquid commercial form and then still 160 g Phosphoric acid (diluted 1: 8 with water) 1000 g
added. After 5 minutes, the diazotization is complete without the development of nitrous gases and the printing paste thus obtained can be printed.

The second printing paste from Example 2 is used here as the printing ink with the reactive dye.

Both printing pastes are printed side by side on the primed fabric, this is dried and then steamed at 103 ° C for 6 minutes to fix the dye.

A print corresponding to example 2 is obtained on the goods. A tensile strength test showed no damage to the fabric.

Example 4

A cotton fabric is primed and dried as in Example 1. In addition, a printing ink of the following composition is used:

Furthermore, a second printing ink is produced

These two printing pastes are printed side by side on the primed fabric and this is then dried at 100 ° C.

The goods are then steamed at 105 ° C for 8 minutes, rinsed with hot and cold water and soaped neutral at 90 ° C.

A yellow reactive print in addition to a black print of the development dye is obtained on the fabric treated in this way.

Example 5

A cellular wool fabric is washed with an aqueous solution containing 20 g of Azoic Coupling Component 5 with the CI no. Contains 37610 (3,3'-dimethyl-4,4'-bis-acetoacetylamino-diphenyl) and 15 g of sodium hydroxide solution (32.5%) in a liter, padded and dried. Two printing inks are prepared for the subsequent overprint. The printing paste with the diazonium compound consists of: 300 g of master batch I from example 1, 12 g a 50% aqueous solution of Azoic Diazo Component 44 with CI no. 37000 (o-chloroaniline hydrochloride), 300 g of Stammanstzes II from Example 1, but here contains citric acid instead of phosphoric acid, and 388 g water 1000 g .

The printing paste with the reactive dye is composed as follows: 40 g of the dye Reactive Orange 16 with the CI no. 17757, 6 g Formaldehyde solution (35%), 44 g Urea, 700 g a neutral, 6% alginate thickening and 210 g water 1000 g .

These two printing pastes are printed side by side on the primed fabric and dried at 100 ° C. Then proceed to the dye fixation and completion of the pattern as in Example 4.

A brilliant red reactive print is obtained on the fabric treated in this way, without being impaired by acid escaping in the vapor, in addition to a yellow from the development dye.

Example 6

A cotton fabric is padded with an aqueous solution containing 20 g of Azoic Coupling Component 44 with CI no. Contains 37613 (5-chloro-2-acetoacetylamino-1,4-dimethoxybenzene), 32 g ethanol, 40 g water and 20 g sodium hydroxide solution (32.5%) in liters. The dried fabric is printed with a printing ink of the following composition: 300 g of master batch I from Example 1 are with 20 g the 45% aqueous dispersion of Azoic Diazo Component 13 with the CI no. 37130 (5-nitro-o-anisidine) and 300 g of master batch II from Example 1 mixed. 380 g Water will complete on 1000 g added.

In addition, the reactive printing paste of Example 1 containing the dye Reactive Blue 19 with the C.I.no. 61200. The further processing of the print for the purpose of dye fixation and completion is carried out as in the previous examples.

A yellow print with good fastness properties is obtained on the goods alongside one of blue color.

In all examples, in addition to the reactive printing paste mentioned, other reactive printing pastes can be printed as illustration colors.

It is also possible to add other C.I. Print Azoic Diazo Components if the measures according to the invention are observed when preparing them.

Claims (8)

1. A one-phase process for producing prints on textiles containing cellulose or exclusively composed of cellulose fibers which have been pre-impregnated with coupling components under alkaline conditions by separate over-printing using reactive dyes alongside directly couplable diazonium compounds which have been produced from primary aromatic amines with the addition of sodium nitrite and in the presence of acid or acid-supplying substances by diazotization with simultaneous development of water-insoluble azo dyes as a result of spontaneous coupling, drying the prints, and fixing the reactive dyes by steaming, which comprises using as the sole acidic agent in the diazotization of the applied amines an acid which is not volatile in the drying operation nor in the steam of the fixing operation and, if the print pastes containing the diazonium compounds need to be buffered, only water-soluble salts of such acids.
2. The process of claim 1, wherein the diazotization of the amine and the buffering of the diazonium compound takes place in aqueous solution and this solution is directly thickened for printing.
3. The process of claim 1, wherein the diazotization is effected by combining a first thickener containing sodium nitrite with a further thickener containing the acid which is not volatile in steam, the amine having been admixed into one of the two thickeners, preferably into that containing the nitrite.
4. The process of claim 1, wherein first the finely divided primary aromatic amine and then the acid which is not volatile in steam are stirred into a thickened sodium nitrite solution, which, if desired, may be followed by buffering the acid.
5. The process of one or more of claims 1 to 4, wherein the acid which is not volatile in steam and is used for diazotization is glycolic acid, citric acid, tartaric acid, oxalic acid, sulfuric acid, but preferably phosphoric acid.
6. The process of one or more of claims 1 to 4, wherein the acid used for diazotization is hydrochloric acid, which is then buffered by means of tertiary or secondary sodium salts of phosphoric acid.
7. The process of one or more of claims 1 to 6, wherein the print pastes containing the reactive dye have been brought to a neutral pH.
8. The process of one or more of claims 1 to 7, wherein, after printing and drying of the prints, the printed material is steamed at 100° to 105°C for 6 to 8 minutes in order to fix the reactive dyes, the excess alkali from the naphthol pre-impregnation being utilized for fixing the reactive dyes.