DE2003363A1 - Process for dyeing and printing textiles with Kuepen- and reactive dyes - Google Patents

Description

The present invention relates to the joint application of reactive and vat dyes to cellulose fibers and their blended fabrics according to the so-called two-phase process by padding the dyes with one another in a first stage or by printing them with one another and / or next to one another, drying them and in a second stage in a solution of Hydroxides and neutral salts padded at room temperature, characterized in that this solution contains formaldehyde sulfoxylate and a water-soluble nitroaryl compound and that the tissue is then subjected to a heat treatment in the moist state. Then it is finished as usual by rinsing, oxidizing, boiling soapy, rinsing and drying.

It is well known that the ranges of reactive dyes and vat dyes have certain gaps and weaknesses, some of which compensate for each other, so that it would be of great technical interest if the two classes of dyes could be combined with one another. This stands in the way of the fact that the reduction process inevitable for the fixation of vat dyes leads to the destruction of the reactive dyes.

Reactive dyes are far superior to the vat dyes, primarily in red and turquoise blue, and it seems hardly conceivable that this purity and brilliance of the nuances can ever be achieved with vat dyes. These, in turn, are at least as good as the reactive dyes in the blue and green tones in terms of brilliance and purity, and are also far superior in terms of economy and authenticity. The latter also applies to the muted tones such as gray, brown, olive and khaki.

Dyeing together is about to be able to use reactive dyes for shading and enhancing vat dyeings, with the intention of combining optimal luminosity with maximum authenticity. When it comes to printing, it is primarily about being able to print the two classes of dye side by side. This task, which is more important in terms of use, is by no means easier to solve as a problem, since weaver cases usually arise during printing, i.e. places where the printing inks overlap, so that here too the dyes should be able to be fixed well not only next to one another but also with one another.

In view of the importance of the problem, great efforts have already been made, but none of the proposals known so far has been technically successful because the methods were either too cumbersome or not sufficiently reliable.

BASF made the first suggestion in DAS 1 152 381 of March 15, 1961 to be able to print vat and reactive dyes. It is based on the idea of adding the reducing agent to the vat printing ink and then padding on the required alkali in a second stage. Appropriately, the reactive dyes are also protective additives in their printing inks against and that in the form of the oxidizing agents known for this purpose. This process was probably unsuccessful, among other things, because when using an inert reducing agent such as formaldehyde sulfoxylate (known in the trade as Rongalit C® [® = registered trademark]) unreasonably long steaming times or poor fixation of the vat dyes have to be accepted. If, on the other hand, more active reducing agents are used, as are commonly used today in two-phase printing, e.g. acetaldehyde sulfoxylate or its reaction products with amines (known commercially as Rongal A®), then the printing ink stability suffers as a result of the reduction in the vat dyes, which results in a change in viscosity; In addition, excessive destruction of the reactive dyes due to reducing agents that bleed out of the printing inks into the alkali bath is to be expected when working continuously.

Another suggestion that has been widely discussed, especially in American specialist circles, which has been tried out in practice under the name "Everbrite" ®, is based on the classic recipe for two-phase printing. In addition to lye and salts, the developing bath contains sodium hydrosulphite as a reducing agent, the amount of which must be dosed so carefully that the

Vat dyes is achieved without the reactive dyes being destroyed too far. Despite the selection of the most easily fixable vat dyes and the most stable reactive dyes, the process was evidently too delicate and not operationally reliable to be successfully introduced.

Proposals have also become known to print the reactive dyes with alkali next to the vat dyes and to fix them by drying and steaming before they were subsequently padded with lye and Rongal A® in a bath to fix the vat dyes and steamed again. Apparently, the pre-fixing of the reactive dyes increased their stability against reduction. This proposal was not only too complicated, it was apparently also insufficiently operationally reliable, so that it was also unsuccessful.

It has now been found that by combining a reducing agent with a selected oxidizing agent in the developing bath, a kind of buffer effect can be achieved with simultaneous activation, which enables vat and reactive dyes to be fixed well with one another and next to one another in a reliable manner.

In contrast to the proposal of the Badische Anilin- und Sodafabrik, the oxidizing agent is added to the reducing agent so that the former can be measured so that the latter is always in excess and consequently dominates. In addition, the choice of both partners is very selective. Not all aldehyde sulfoxylates (alkanesulfinic acids) are suitable, only formaldehyde sulfoxylate (oxymethanesulfinic acid) and, among the oxidizing agents, only the nitroaryl compounds show a positive effect. According to the BASF patent, however, the following selection is listed as suitable: "Substances that reduce or eliminate the destructive influence of reducing agents on the dyes. Such substances are oxidizing agents such as inorganic nitrites, preferably alkali or alkaline earth metal nitrites, inorganic halogenates, organic nitrogen compounds in which the nitrogen is bound to oxygen with at least one bond and at least one bond carries an element that is not oxygen or nitrogen, for example nitroparaffins, aromatic nitro and nitroso compounds, nitropropane, sodium nitrite, nitrium chlorate and sodium nitrobenzenesulfonate are only a few representatives of the oxidizing agents, which can be added to the printing pastes ". So there are many more options than those cited here.

It follows from this that the combination according to the invention was not obvious and that the technical effect achieved can be described not only as valuable but also as extremely surprising.

It is known that activation of formaldehyde sulfoxylate can be achieved with nitroaryl compounds, see, for example, US Pat reactive dyes present. On the contrary, some of these are damaged even more than if an active reducing agent such as Rongal A® had been used from the outset.

Particular mention should be made of the known reduction accelerators for formaldehyde sulfoxylate found in practice, such as Fixing accelerator TX® from BASF (cobalt dimethylglyoxime), see e.g. DAS 1 239 269; Calfac A® from ICI (cobalt complex of dioxyanthraquinone); Hydritex D® from Ventron Corp. USA sodium borohydride), see e.g. Brit.Pat. 999 589 CIBA: Anthraquinone-2-sulfonic acid, according to British Patent 787 343 of the ICI; complex alkali metal cyanides of Cr, Fn, Co, Ni according to Belg.Pat. 613 287.

The present procedure is for staining like

Printing a two-stage process with intermediate drying. In a first stage, the vat dyes are applied by padding or printing, without the addition of reducing agents, but optionally with the addition of the customary thickeners, wetting agents, hydrotropic substances and migration-inhibiting additives, and dried. The vat dyes are basically to be used in the form of modern commercial forms with extremely fine distribution (known in the trade as colloisol, microdisperse, etc.). Some dyes that are very difficult to reduce, such as khaki 2G (CI Vat Green 8), cannot be fixed, but all important vat dyes can be fixed in the same good yield as when using hydrosulfite or Rongal A. Reactive vat dyes or colloidally soluble, hydrophilic, so-called " Water-soluble "vat dyes" can also be used, as can the so-called sulfur vat dyes (known commercially as hydron or hydrosol).

The reactive dyes are added to the dispersion or printing ink of the vat dyes or printed separately in thickened form. They can contain the usual additives such as urea, alginates, wetting agents and acid-binding agents such as sodium bicarbonate or potash. The latter additives can be a partial in hot drying

Prefix the reactive dyes. Since the duration of the steaming time does not depend on the vat dye but on the reactive dye, this can be advantageous in the case of dyes that react particularly slowly, such as phthalocyanine derivatives or dyes with a chloropyrimidine group.

As such, there are no restrictions on the reactive dyes, except for those that have to be taken into account when printing, namely no substantive agents that are difficult to wash out and stain the white printing fonds. Polyazo dyes are therefore unfavorable, as are most metal complex dyes. With regard to reactive groups, all known and commercially available variants are suitable. Examples of reactive groups include: mono- and dichlorotriazine, di- and trichloropyrimidine, dichloroquinoxaline, dichlorophthalazine, chlorobenzothiazole, dichloropyridazone, methylsulfonchlorpyrimidine, sulfatoethyl sulfone, sulfatoethyl sulfamide, acrylamide, etc.

The following list is given as examples of such reactive dyes:

The developing solution contains hydroxides, preferably the alkali metals such as sodium and potassium hydroxide, in concentrations between 0.2 to 2-n, preferably 0.5 to 1-n. Sodium chloride or sodium sulfate are used as neutral salts. Their concentration should preferably be close to the saturation limit. Formaldehyde sulfoxylate is added in quantities of 30 to 100 g per liter, preferably 50 g / l. The concentration of the nitroaryl compound should be at least 10% of the reducing agent, but in no case exceed 50%. Preferably 20% is used. Possible water-soluble compounds are the nitrobenzenecarboxylic acids, the nitrostilbene disulphonic acids, the nitronaphthalene sulphonic acids, but especially the meta-nitrobenzenesulphonic acid, which is the cheapest.

The print or dye is impregnated at room temperature on a padder. After squeezing to 50 to 100% weight increase, the heat treatment is then immediately followed in the moist state. It is best carried out in a steamer, whereby a one-sided product guidance as it exists in the sheet steamer is necessary for prints. A guide between a heated roller and a sealing rubber blanket, as is the case with the Montforts reactor, is also possible.

The duration of treatment depends primarily on the device used. It varies between 10 to 60 seconds. Normally, 30 seconds will be considered a favorable mean.

After steaming, it is completed as usual by intensive rinsing, oxidizing, boiling soapy, rinsing and drying.

The fabrics used are those made from natural and regenerated cellulose, preferably in a boiled and bleached state. They can be present alone or in a mixture with synthetic fibers such as polyamides or polyesters. In the latter case, disperse dyes can also be added to the dye solutions and printing inks. The heat treatment after impregnation should be particularly intensive in this case. It is advantageous to follow the drying process with a heat setting of e.g. 60 seconds at 200 ° in order to fix the disperse dyes.

In the examples below, the parts are parts by weight, the percentages are percentages by weight, and the temperatures are given in degrees Celsius. The reactive dyes were used in commercially available coupons, the vat dyes in microdisperse powder or dough form.

Example 1.

The following vat printing inks are made: a) 60 parts of C.I. Vat Orange 19, 140 parts of water, 800 parts of thickener, b) 50 parts of C.I. Vat Brown 3, 150 parts water, 800 parts thickener, c) 100 parts C.I. Vat Violet 1, 100 parts water, 800 parts thickener, d) 200 C.I. Vat Blue 4, 800 parts of thickening, e) 200 parts of Cibacron printing black FTL dough, 800 parts of thickening.

Microdisperse powder is used for a to c, and micro-dough for d and e.

The stated thickening is obtained as follows: 350 parts of Solvitose C®5 8% and 350 parts of Polyprint multus® 5% are mixed with 50 parts of white spirit and 50 parts of water on a high-speed stirrer until a homogeneous paste is formed. The following reactive printing inks are also produced: 50 parts of dye 3 (see list above), 100 parts of urea, 350 parts of water, 50 parts of thickener. 50 parts of dye 4, 100 parts of urea, 50 parts of meta-nitrobenzenesulfonate 20% solution, 100 parts of potash 1: 2,

200 parts of 0.1N sodium hydroxide solution, 500 parts of 4% alginate thickening. 50 parts of dye 8, 100 parts of urea, 150 parts of potash 1: 2, 200 parts of 0.1-n sodium hydroxide solution, 500 parts of alginate thickener.

These eight printing inks are used to print a fabric made of mercerized cotton on a Rouleaux printing machine.

After printing, drying is carried out for 60 seconds at 200 ° in a drying box. The printed fabric is then impregnated at room temperature on a padder in a solution of 50 parts of formaldehyde sulfoxylate, 50 parts of meta-nitrobenzenesulfate 20%, 60 parts of 10-n sodium hydroxide, 15 parts of borax and 725 parts of saturated saline solution.

The weight is increased by about 80% and the padded fabric is introduced into a steamer in a moist state and steamed for 30 seconds in air-free steam at 110 to 115 °. It is then reoxidized as usual, soaped at the boil and each time rinsed. One obtains an orange, a brown, two red tones, a violet, a blue and a turquoise as well as a black, which are strong and well developed.

Example 2

20 parts of reactive dye 5 are dissolved in 930 parts of water and 50 parts of CI Vat Red 10 are dispersed in this solution. A fabric made of viscose rayon is padded in this solution, squeezed off to a 70% increase in weight, passed through an infrared pre-dryer and continuously dried at 200 ° for 60 seconds. The fabric is then padded again in a solution of 50 parts of formaldehyde sulfoxylate, 100 parts of m-nitrobenzenesulfonate 10%, 120 parts of 5-n sodium hydroxide solution and 730 parts of saturated sodium sulfate solution, squeezed
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Weight gain, steams in air-free steam for 60 seconds at 110 to 115 ° and rinses, oxidizes, soaps and rinses as usual. A real, brilliant red coloration results.

Used instead of the above-mentioned dyes
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C.I. Vat Green 1 and proceed as described above on a linen fabric, the result is a true and brilliant blue-green coloration.

Claims (4)

1. A method for dyeing and printing cellulose fibers and their blended fabrics with vat and reactive dyes, characterized in that the fabric is first impregnated or printed with these dyes, dried and then in an aqueous solution of alkali hydroxides and neutral salts, the formaldehyde sulfoxylate and a water-soluble Contains nitroaryl compound, impregnated and subjected to a heat treatment. 2. The method according to claim 1, characterized in that alkali metal carbonates or bicarbonates are added to the reactive solutions and printing inks and dried while hot. 3. The method according to claim 1, characterized in that the alkali metal salt of a nitroarylsulfonic acid is used as the water-soluble nitroaryl compound. 4. The method according to claim 3, characterized in that the sodium or potassium salt of m-nitrobenzenesulfonic acid is used as the alkali metal salt of a nitroarylsulfonic acid.