EP0296485A2 - Method of dyeing textile materials containing polyester fibres on jet machines - Google Patents

Abstract

The newly developed jet dyeing machines with aerodynamic movement of goods allow a drastic reduction in the liquor ratio in addition to the addition of highly concentrated dye solutions or dispersions directly into the driving gas cycle under isothermal conditions. However, prerequisites for this are processed, i.e. finished dyes. According to the invention, it has now been found that the elaborate finish treatment is unnecessary if non-finished disperse dyes are highly concentrated in suitable, preferably water-miscible, ecologically or toxicologically acceptable organic solvents and these solutions are added to the circulating gas stream in a targeted manner using the new technology , whereby a dyestuff dispersion suitable for dyeing is formed, which then dyes the dye regardless.

Description

The present invention relates to a method for isothermal, discontinuous dyeing in jet dyeing machines in endless form as a woven or knitted strand of textile material made of polyester fibers or their mixtures with other fibers in an aqueous medium with heat-fixable colorants according to the pull-out technique, the feed for the transport of the Goods within the self-contained jet system via the actuation of the nozzle system by means of the kinetic energy of a circulated, in relation to the intended specific treatment effect, ie the dyeing behavior of dye and fiber material, non-inert gas flow takes place, this flowing gas in the nozzle section for the goods drive the colorants are also added in the form of an atomized preparation and thus brought into contact with the textile goods according to the preselected temperature and pressure conditions, there immediately come into effect in the fixing state.

A generic method in which textile fabric strands are subjected to wet finishing, in particular for dyeing, in jet piece dyeing systems is described in European Patent EP-B-0 078 022. This working principle explained for the dyeing of the textile material in endless form in the cited literature reference, which allows the seamless transition from successive treatment courses without a standstill under isothermal conditions, but is to be carried out in a complex process for its implementation equalizable disperse dyes depend on finished products; ie the water-insoluble colorants obtained after chemical formation must first be brought into a dispersible or self-dispersing form by grinding and mixing in relatively large amounts of dispersants. It is only due to the degree of fine distribution on which the dye individual is based that perfect color results can be achieved using this conventional method.

From the German patent DE-C-32 10 380, however, a pull-out method is now known, according to which textile bobbins containing or consisting of synthetic fibers are dyed with non-finished dyes. For this purpose, the water-insoluble dyestuffs under consideration are dissolved without prior preparation by means of a finish geared to suitable dyeing properties, before they are used in water-miscible organic solvents, and the solution thus obtained is then brought into the circulating textile material at dyeing temperature flowing, dye-free aqueous liquor. Precipitation from the organic solution then results in a dispersion of the dye in the aqueous dye bath which is suitable for dyeing. In the course of this type of treatment, however, relatively large amounts of the organic solvent are consumed, so that this special process, which is also limited to dyeing machines with a long liquor ratio and high liquor recirculation, was not able to assert itself for price reasons.

However, it is still one of the most urgent needs in practice, even if only in some areas, to save the costly finish of the dyes, especially in view of the growing importance of synthetic fibers in general and the production capacities for dyes, the bottleneck of which has proven to be the finish.

The invention discussed below was therefore primarily based on the object of expanding the principle of use for dyes without a finish and of transferring them to modern jet dyeing techniques. The aim of this project was to achieve a breakthrough in the field of finishing textile goods in jet dyeing machines, which is becoming increasingly important.

Within the scope of these efforts, it has now been found that, based on the procedure according to the European patent EP-B-0 078 022, good coloring results can also be achieved with regard to levelness if the colorants are used as a liquid preparation of a finish which is not subjected to a finish Dyes and / or pigments which are practically insoluble or sparingly soluble are metered into the driving gas stream in the form of a preferably highly concentrated solution in one or more organic solvents, and then, due to the dilution caused in the aqueous environment present, the dissolved colorants are finely dispersed on the textile material and precipitated the coloring finally comes to an end under isothermal conditions.

The feasibility of the present invention and, at the same time, the discontinuation of the advantages which can be achieved thereby are based on the fact that the jet dyeing machines with aerodynamic goods movement, which have recently become available in practice, drastically shorten the liquor ratio in addition to adding highly concentrated dye solutions or dispersions directly into allow the driving gas cycle under isothermal conditions. A prerequisite for this was the latter The development of suitable dosing devices, which enable the targeted, precisely dimensioned injection of even small amounts of liquid into the circulated gas stream, was carried out over time. On this basis alone, it could be dared to subject the feasibility of the inventive idea to a test.

However, in order to arrive at the invention in question, a number of prejudices had to be overcome:

On the one hand, the question had to be asked whether the dyes present in real solution had any possibility of compensating for achieving level dyeings even when they first came into contact with the fiber material under fixing conditions, or whether every chance was not given from the outset.

Secondly, it could indeed be considered to be proven that the application technology from the gas stream enables treatment agents to be applied in a level manner under less drastic conditions. However, it remained extremely uncertain whether this could still be achieved under the circumstances according to the invention, ie with reduced amounts of liquor and highly concentrated dye solutions. Because it was inevitable for the process to keep the necessary solvent to a minimum so as not to fail due to the prices or ecological requirements, i.e. the dosage of the small amount of dye solution must be precisely controlled in order to achieve an even primary distribution in the aqueous liquor on the textile.

The procedure itself is as follows:

With simultaneous wetting and heating by the steam / air flow generated by the fan and also Simultaneously adding the necessary liquor (in the range of 1: 1.2 to 1: 5 by weight of the goods), the textile goods are introduced into the jet dyeing machine, sewn together to form an endless strand and, after the jet has been closed, steam or hot air is used to circulate them as well set to the selected dyeing temperature.

On the other hand, the non-finished dye is dissolved in the solvent provided in the separate vessel. Depending on the solvent, this solution is 70 - 150 ° C hot, so it can be without having too great an effect on the temperature of the dyeing system, i.e. be introduced into the jet system under isothermal conditions.

This solution is then metered into the driving gas stream of the jet dyeing machine via a precisely working metering pump in such a way that the same amount of solution is always added during one cycle of the textile material. The metering extends under isothermal conditions to 5 to 10 rounds of the color material. The mixture is then left to run at the dyeing temperature for a further 30 minutes, the goods are then cooled and the dyeing is subsequently treated as desired.

According to the invention, dyeing is possible at temperatures below 100 ° C., preferably between 90 ° and 100 ° C., under atmospheric pressure, and also at temperatures above 100 ° C., preferably between 120 ° and 135 ° C., at the increased pressure that arises .

Suitable organic solvents for the process according to the invention are preferably those which are at least partially soluble or miscible with water under the dyeing conditions used and in which the pure dye and / or the pigment can be dissolved in a sufficiently high concentration. The dye or that According to the process, pigment is dissolved in the organic solvent at elevated temperature and metered into the liquor circuit from a heated batch vessel. Examples of such solvents which are used alone or in the form of mixtures are:

Alcohols such as 3-methoxybutanol, but above all the glycols and their ethers or the esters of such glycol ethers as glycol (monoethylene glycol), diglycol, triglycol, methyl glycol, methyl glycol acetate, methyl diglycol, ethyl glycol, ethyl diglycol, ethyl diglycol acetate, propyl glycol, n-butyl glycol Butyl diglycol; Ketones such as acetone, methyl ethyl ketone, diacetone alcohol; cyclic ethers such as tetrahydrofuran, tetrahydrofurfuryl alcohol, dioxane; Esters and lactones such as glycol monoacetate, sec-butyl acetate, ethyl lactate, butyrolactone; low carboxylic acids such as formic acid, acetic acid; nitrogen-containing compounds, optionally of a cyclic nature, such as dimethylformamide, dimethylacetamide, pyridine, N-methylpyrrolidone, morpholine; sulfur-containing compounds such as dimethyl sulfoxide. Polar, aprotic solvents are particularly suitable. Of particular note are dimethylformamide and dimethyl sulfoxide, which are particularly suitable due to their dissolving properties and their physiological-ecological behavior.

In second place are polyethylene glycols with a molecular weight between 400 and 2000, possibly even higher. Here too, the dyes are dissolved in the heated polyglycol. Higher molecular weight polyglycols are first melted and the dye is then dissolved in this melt.

It is irrelevant for the claimed process whether the solvents used may be for foaming tend, since the foam can only form in the textile itself and promotes the even distribution of the treatment agents in it rather than hampers. This circumstance is then considered to be a further advantage in favor of the present method, since foaming in conventional jet systems has otherwise been recognized as the reason for running difficulties and uneven coloring.

Finally, according to the process, solvents which are still immiscible or water-insoluble, such as e.g. halogenated hydrocarbons, or substances which act as carriers. When using such solvent types, two process variants are then available for carrying out the invention: First, by metering the solution of the dye directly into the dyeing cycle; on the other hand, by producing a predispersion of the dye from the solution by dilution with hot water and then metering it in. In any case, however, the halogenated hydrocarbons are eliminated from the gas / liquor cycle again during the actual dyeing process, so that at the end of the dyeing, residues of the liquor which are hardly ecologically acceptable remain on the goods or in the jet system. These halogenated hydrocarbons are chlorinated, fluorinated or mixed halogenated aliphatics with 1 - 4 carbon atoms.

According to the invention, primarily dyestuffs are used as dyestuffs which meet the abovementioned conditions with regard to solubility. Such products are well known and are described in the Color Index, 3rd edition, 1971, volume 2 and supplements 1975 and 1982 under the class name "CI Disperse Dyes". According to their constitution, most disperse dyes belong to the azo, anthraquinone or in a few cases to the nitro or quinophthalone compounds.

According to the claimed process, the disperse dyes are used in the unfinished state and are used, for example, as press cakes, i.e. coming from the factory and not yet finished, used [non-finished (raw) fabric]. In addition to the advantage of making unfinished dyes accessible to PES exhaust dyeing, the present invention also makes it possible to dye with very good levelness those finished disperse dyes which are difficult to dye using the exhaust methods previously used.

According to the present invention, pigments can also be used if they meet the requirements with regard to solubility, in particular organic pigments which, in the course of the new process, do not require a binder system as a mediator for their binding to the fiber, and the Color Index, 3. Edition 1971, Volume 3 under the term "CI Pigments" are divided. The products listed under the name "C.I. Solvent Dyes" in the Color Index, 3rd edition 1971, volume 3 have also proven to be suitable in terms of the process.

To carry out the new process, the dyes and / or pigments mentioned (in the nature specified above) are dissolved in a solvent (of the type defined above) alone or in a mixture thereof in as high a concentration as possible and this concentrated dye solution is metered in a certain time sequence injected into the dyeing system, which corresponds to the circulation times of the textile goods in the jet dyeing machine.

The new process offers a number of advantages over the closest comparable prior art:
- The pure dyes that can be used for dyeing are considerably cheaper as unfinished manufactured goods than the finished commercial products. They only need to be standardized to the same color strength.
- According to the process, dyes and pigments can be used which previously appeared to be unsuitable in finished form or with a binder for PES dyeing to achieve level dyeings.
- The dyeing time is reduced due to the rapid attainment of level dyeings.
- The problem of foam formation is also negligible.
- Since in most cases no or very little dispersant and / or leveling agent are added to the dye solution in the preparation vessel or the circulating, blind liquor, there are no corresponding residues on the fiber or in the bath. This makes the post-treatment of the dyed goods easier or the post-treatment time shorter.

In many cases, for example, the reductive aftertreatment can be dispensed with and the coloring only needs to be rinsed.

If no surfactants are present in the bath, after the first dye has been removed, the dyeing can again be carried out easily on the remaining aqueous liquor.
- In the process according to the invention, the coloration of the PES fiber is better in most cases than in the previously customary working methods.

The claimed process can be carried out very safely and provides very good reproducible dyeings because the dosage of the dye solution is controlled automatically.

The organic solvent in the remaining liquor and the associated wastewater pollution appear to be disadvantageous compared to the conventional process for dyeing from aqueous dispersion. To this end, it must be established that the amount of such a solvent in the liquor is very small, that in most cases no dispersing and leveling agents get into the waste water with the remaining liquor and that one can possibly avoid reductive aftertreatment.

The following examples are intended to explain the principle of the process according to the invention, but in particular not to restrict it with regard to the solvents used, since a selection of the most suitable solvents has already been made.

example 1

80 kg of a knitted polyester fabric are fed to the nozzle system of a jet dyeing machine of the type shown in EP-B-0 078 022 steam / hot air mixture with the simultaneous addition of 120 l of hot water (80 ° C) and 3 cm³ / l acetic acid (60%) introduced into the jet system and sewn together to form an endless strand. After the jet has been sealed off from the outside atmosphere, the flow of the colored material is started with the aid of a steam / hot air mixture which is itself in circulation by actuating a blower, while heating the dyeing system together with the textile material to a dyeing temperature of 125 ° C and then kept constant by regulating the temperature of the driving gas mixture via a heat exchanger.

in reiner, nicht gefinishter Form, bei 110°C in 4 l Dimethylformamid gelöst. Nach ca. 10 Minuten Laufzeit des Jets wird nun diese Lösung über eine Dosierpumpe in den heißen Gasstrom so eingedüst, daß nach Ablauf von 10 Umläufen des Textilgates das Zudosieren der flüssigen Farbstoffzubereitung abgeschlossen ist. Bei konstanter Temperatur wird der Strang alsdann noch 30 Minuten weitergefärbt, währendessen man den Warenumlauf durch das Dampf/Heißluft-Gemisch unter den eingestellten Temperaturbedingungen fortführt.640 g of the yellow disperse dye of the formula are separate

in pure, not finished form, dissolved in 4 l dimethylformamide at 110 ° C. After the jet has run for about 10 minutes, this solution is then injected into the hot gas stream by means of a metering pump in such a way that after 10 rounds of the textile gate the metering in of the liquid dye preparation is complete. The strand is then dyed at a constant temperature for a further 30 minutes while the circulation of goods is continued through the steam / hot air mixture under the set temperature conditions.

After the dyeing period has ended, the dyeing system in circulation, which is under overpressure, is relieved of pressure by opening a so-called hot (HT) drain, whereby noticeable cooling and the now occurring liquor evaporation in the fabric loosen it.

Subsequent addition of hot water (70 ° C) into the jet, which is now at normal pressure, the dyed goods are first rinsed hot, while the air is circulated through the nozzle and the blower. Finally, the coloring produced is reductively treated as usual and rinsed again with water, hot as well as cold.

A level yellow dyeing of the polyester knitted fabric is obtained, which corresponds to a 2% dyeing with the same color body - but in a finished commercial form, in the dyeing result obtained.

Example 2

Already in its cellulose fiber content with the dye C.I. Reactive Blue 21 pre-dyed polyester / cotton blend (70/30) should be over-dyed with disperse dyes:

After the reactive dyeing, the batch weighing 60 kg is already in the jet and is circulated by means of an air drive via the nozzle system. In addition, it is loaded with 150 l of water at 30 ° C from the previous treatment. By adding 500 cm³ of acetic acid (60%), the strand-like product is now made slightly acidic; then by blowing steam and simultaneously heating the circulated air by means of a heat exchanger textile and liquor heated to 130 ° C. A complete temperature equalization in the dyeing system is achieved after approx. 5 minutes.

ebenfalls in einer nicht mit einem Finish versehenen Form, in 1,5 l Dimethylacetamid bei 150°C gelöst. Diese Lösung wird nun bei konstanter Temperatur (130°C) sowie ständig umlaufendem Textilgut während 5 Umläufen desselben über das Düsensystem dem antreibenden Dampf/Heißluft-Gemisch gleichmäßig zudosiert.Separately, there are now 63 g of the yellow disperse dye from Example 1 and 4 g of the blue disperse dye of the formula

also in a non-finished form, dissolved in 1.5 l dimethylacetamide at 150 ° C. This solution is now evenly metered into the driving steam / hot air mixture over a nozzle system at constant temperature (130 ° C.) and continuously circulating textile material during 5 circulations.

After a further 20 minutes of treatment under constant conditions, the dyeing is ended as in Example 1 after releasing the excess pressure by hot and then cold rinsing with water.

You get a turquoise / yellow bicolor effect on the goods.

Example 3

According to the invention, the dyeing of the polyester portion of the blended fabric according to Example 2 can also be carried out in the following manner at a treatment temperature of 100 ° C. under normal pressure:

After the reactive dyeing of the cellulose fiber portion and the addition of acetic acid have been carried out, the goods are then only heated to 100.degree. In this case, however, the disperse dyes listed in the same proportions are dissolved in 700 cm 3 of a commercially available carrier based on methyl salicylate at 100 ° C. and this solution is then metered into the dyeing system as in Example 2. After the end of the dosing process, 2 - 3 l of hot water are also added to the jet by means of the dosing pump in order to enter all carrier / dye residues from the nozzle section into the circulating system. After a further 30 minutes of dyeing at 100 ° C, the dyed goods are rinsed hot and cold with water.

The same dyeing result as in Example 2 is obtained.

Example 4

84 kg of a fabric made of 100% polyester fibers are introduced into a jet dyeing machine of the type depicted in EP-B-0 078 022 via a nozzle operated with steam / hot air and at the same time moistened and by adding 170 l of hot water (85 ° C) loaded with liquor. The pH of the hot water has previously been adjusted to pH 5 using acetic acid.

After the polyester fabric has been sewn together to form an endless strand, the jet system is closed pressure-tight and the circulation of goods is started by means of steam / hot air. The dyeing system is finally heated to a treatment temperature of 125 ° C. by heating the steam / hot air mixture and blowing in further steam.

290 g des gelben Dispersionsfarbstoffes der Formel

und 210 g des gelben Dispersionsfarbstoffes der Formel

alle drei Farbstoffkomponenten der Mischung in reiner, nicht gefinishter Form, bei 120°C in 7 l Polyethylglykol mit einem Molgewicht 600 gelöst. Diese Lösung wird nun heiß in den umgewälzten Gasstrom so eindosiert, daß der Dosiervorgang sich gleichmäßig über 12 Umläufe des Farbgutes im Jet erstreckt. Danach wird die Ware noch weitere 30 Minuten unter den gleichen Temperaturbedingungen weitergefärbt, daraufhin durch Druckentlastung wie in Beispiel 1 zunächst abgekühlt, hernach auf übliche Weise heiß und kalt mit Wasser gespült, reduktiv nachbehandelt und schließlich erneut mit Wasser heiß und kalt gespült.Separately, you now have a mix of 675 g of the blue disperse dye of the formula

290 g of the yellow disperse dye of the formula

and 210 g of the yellow disperse dye of the formula

all three dye components of the mixture in pure, not finished form, dissolved at 120 ° C in 7 l of polyethylene glycol with a molecular weight of 600. This solution is now metered in hot into the circulated gas stream in such a way that the metering process extends evenly over 12 cycles of the ink in the jet. The goods are then further dyed for a further 30 minutes under the same temperature conditions, then first cooled by relieving pressure as in Example 1, then rinsed hot and cold with water in the customary manner, subjected to reductive treatment and finally rinsed again with hot and cold water.

A level green coloring of the fabric is obtained.

Example 5

(in reiner, nicht gefinishter Form) in Perchlorethylen zudosiert.60 kg of a fabric made of 100% polyester fibers in strand form are introduced into a jet together with 100 l of water at 80 ° C., as in the previous examples. The water is adjusted to a pH of 5. After the temperature of the system has been brought to 130 ° C., 2 l of a solution of 30 g of the red disperse dye of the formula are added to the circulating gas stream which provides the goods advance

(in pure, not finished form) metered in perchlorethylene.

During the subsequent 30-minute dyeing period at 130 ° C, the perchlorethylene is removed from the system via a bypass and the dyeing is then ended by actuating hot (HT) bleed, hot and cold rinsing with water.

You get a fabric that is dyed pink.

Claims (7)

1. Process for isothermal, discontinuous dyeing in continuous jet dyeing machines as a woven or knitted strand of textile material made of polyester fibers or their mixtures with other fibers in an aqueous medium with heat-fixable dyes according to the pull-out technique, the feed for the transport of the goods within the in a self-contained jet system via the actuation of the nozzle system by means of the kinetic energy of a circulated gas stream which is not inert with respect to the intended specific treatment effect, the colorants in the nozzle section for the goods drive are simultaneously added in the form of an atomized preparation and so on brought into contact with the textile material in accordance with the preselected temperature and pressure conditions, come into effect there immediately in the fixing state, characterized in that the colorants are practically in water as a liquid preparation of those not subjected to a finish Insoluble or sparingly soluble dyes and / or pigments in the form of a solution in one or more organic solvents are metered into the driving gas stream, the dissolved colorants are then finely dispersed on the textile material due to the dilution caused in the aqueous environment present, and the coloring is finally reduced isothermal conditions. 2. The method according to claim 1, characterized in that the organic solvent is a water-miscible solvent. 3. The method according to claim 2, characterized in that the organic solvent is dimethylformamide. 4. The method according to claim 1, characterized in that the organic solvent is a water-emulsifiable solvent. 5. The method according to claim 1, characterized in that the organic solvent is simultaneously effective as a carrier. 6. The method according to one or more of claims 1 to 5, characterized in that the dyeing is carried out at temperatures above 100 ° C, preferably between 120 ° and 135 ° C. 7. The method according to one or more of claims 1 to 5, characterized in that the dyeing is carried out at temperatures below 100 ° C, preferably between 90 ° and 100 ° C.