EP0200131B1 - Process for the even dyeing of cellulosic fibres with reactive dyes - Google Patents

Abstract

In a known isothermal dyeing process, the alkali required for fixing the dye is added linearly or progressively to the neutral dyebath under program control. In this process, the amount of alkali added per unit time is initially small and increases progressively in accordance with a preprogrammed profile. This involves passing through a certain (uncontrollable) initial phase until fixation of the dye starts on the cellulose. Subsequently, the rate of fixation attains a maximum and then gradually ceases, to arrive at the final state of the dyeing. To shorten the initial phase (delay time) of dye fixation and in order to slow down the rate of fixation during the steepest part of the curve, it has been found to be advantageous to add the alkali according to a parabolic program.

Description

The dyeing of textile material from cellulose fibers by pulling out alkaline fixing reactive dyes from an aqueous medium is by far the largest and most important area of application for this class of dyes and, according to the previous procedures, usually takes place in the "all-in process" or in a "preliminary process" or in a "stage process", which differ from one another in terms of the type of process management. This takes into account the fact that there is a very high risk of irregularity if, in the case of a reactive dyeing of the dye and electrolyte-containing liquor at dyeing temperature, all of the alkali required for fixing is available at once, which results in a rapid increase in the fixing of the dye.

In order to counteract an undesirably fast fixation of the dye in the initial phase of the dyeing, the entire amount of dye, salt, alkali and, if appropriate, a textile auxiliary at low temperature (room temperature) is put into the pull-out bath in the usual "all-in process" fed dyeing machine loaded with textile goods; thereupon the batch prepared in this way is heated to the intended dyeing temperature and the measures introduced for coloring the goods are now brought to a end for a certain time under the set temperature conditions, the fixing taking place. According to this process, fast-fixing dyes are often used to achieve insufficient levelness of coloration in the presence of otherwise difficult material and / or machine conditions.

Because of this unsatisfactory staining result, there has been no lack of attempts to use the measurement of the alkali additions instead of a special temperature control of the treatment operation to control the course of the fixation (ie the reaction speed) and - in modification of the previously mentioned staining technique - to do the job " Preliminary process "(introduction of dye and salt into the liquor containing the textile material at room temperature and then, after heating to the dyeing temperature, the fixing alkali in several portions and after certain time intervals) or a" step process "(the hot process under the fixing conditions) The liquor containing the goods and dye is first developed to add the salt and a relatively weak alkali, and only later, in portions in 1-3 steps, to add the stronger alkali for final fixation) in order to achieve a more uniform coloring. However, this project was only achieved gradually, mostly by accepting extended total dyeing times, which means reduced production output.

In addition, the striving to achieve good levelness in US-A-4,372,744 describes a further dyeing process in which - in contrast to the prior art discussed above - the dye at the fixing temperature in the cellulose textile, the alkali, electrolyte and if necessary, a dye bath containing textile auxiliaries is metered in in amounts such that less than 10% of the dye fixed on the fiber at the end of the dyeing is present in the dye bath in the reactive bath, but unfixed, during the entire dyeing period. However, this method is not well suited for use in practice because an ongoing measurement / control of the concentration of reactive dye in the dyebath would have to be associated with an extraordinarily high outlay (HPLC or coloristic testing by separate series tests).

Furthermore, an isothermal dyeing process is known from ZA-A-84/1967 and is used in practice, according to which, at dyeing temperature, an aqueous dye bath containing the dye, electrolyte, optionally a textile auxiliary and the cellulosic textile material is used continuously to fix the Reactive dye required alkali is metered. The alkali is dosed automatically; it starts with a small amount of alkali per unit of time, and this addition of alkali is increasingly increased in the course of the metering process in accordance with a specific program. The progression of metering can be controlled between 0% (linear) and 100% (exponential or logarithmic) in 10% steps. The dosing time can be 30, 60 or 90 minutes. (see: "textile practice international", volume 39 (May 1984), pages 493-496). However, there are still some shortcomings to this process: The decisive factor for the use of the fixation of reactive dyes on cellulose fibers is the presence of a certain minimum pH value. If you work according to the dyeing process claimed in ZA-A-84/1967, depending on the composition of the dye bath and the programming of the alkali dosage, an undetermined (uncontrollable) time passes until the "critical" pH value is reached at which fixation of the bulk of the dye begins. This waiting time leads to an extended dyeing cycle or reduced production output.

For this reason, there was a need for an improvement and further development of the measures for optimizing the process conditions in the dyeing of cellulose fibers with reactive dyes, which is also the task for the present invention.

Surprisingly, it has now been found that the above-mentioned deficiencies arise in the conventional dyeing of cellulose fibers can be remedied with reactive dyes if the control of the dosing of alkali metal to the dyebath is not carried out exclusively with variable progression, but rather by carrying out this process in terms of quantity according to a parabolic program. This enables you to shorten the initial phase (waiting time) of the dye fixation on the one hand and on the other hand to slow down the dye fixation during its steepest course (fixation increase depending on progression and time, illustrated by a graphical representation of the fixation curve), what has an extremely positive effect on the product image.

Process for level dyeing of textile material from cellulose fibers in an aqueous medium with alkaline fixable reactive dyes according to the pull-out technique, in which the alkali required for dye fixation over a predetermined period of time in the pull-out phase in accordance with a quantity mode per unit of time that is added to the dye, at least one such dye and, if appropriate, all other ingredients, but no pull-out bath containing fixing alkali, is gradually metered in at fixing temperature, which is characterized in that the alkali metering is carried out in the manner of a parabolic function, with the addition of at least 1/400 of the The total amount of alkali begins, whereupon the addition rate for these amounts of alkali is gradually reduced and tends towards a minimum value towards or equal to zero, and finally by continuous or step-by-step entry of further amounts per time egg unit increasing amounts in the liquor until the total amount of alkali required for fixing the respective reactive dyes is added during the exhaust phase.

Appropriately, the procedure described above is carried out automatically with the aid of a computer-controlled metering device (e.g. from the prototype shown in ZA-A-84/1967), which is capable due to its design features, the alkali metering into the fleet immediately under fixing conditions according to the prescribed Control addition scheme.

According to the present invention, the addition of the fixing alkali to the alkali-free dye bath can be carried out at a constant temperature be made in the range of 30-100 ° C; but there is also the possibility that the temperature is increased or decreased during the actual metering process. The isothermal procedure is preferred, with a relatively low temperature (range around 30-50 ° C.) or a relatively high temperature (range around 60-100 ° C.) being selected, depending on the type of dye or substrate.

The precautions according to the invention for the continuous or approximately continuous control of the addition mode based on the dimensioning of a parabolic function can also be understood in such a way that within the scope of the dosing process, the addition of a first rate corresponding to 1/15 to 1/400, preferably 1/15 to 1 / 73, the total amount of alkali required for dye fixation begins that the addition rate decreases in quantity after 20 minutes at the latest and then continues to increase in volume from then on in accordance with the expiration of the time required for the alkali addition of the pull-out phase finally reached the maximum value. The one for the special The guidelines to be applied for programming the amount of alkali to be added per unit of time depend on the type of reactive dye or its reactive anchor, the type of textile material and the type of dyeing equipment used (for stationary or moving goods). The characteristic of the dosing curve symbolized by a diagram (depending on progression and time) can have a relatively flat or relatively steep curve. The total metering process can generally be completed in a time between 10 and 120 minutes, preferably between 15 and 60 minutes, which makes up a substantial part of the total dyeing time.

wie z.B. der folgenden allgemeinen quadratischen Gleichung:

$\text{y = ax² + bx + c}$

oder einer trigonometrischen Funktion:

$\text{y = b · sin a · x + c · x}$

Hierbei bedeuten

y

= zu dosierende Alkalimenge pro Zeiteinheit

x

= Zeit

n, a, b, c,

= ungleiche oder gleiche reale Zahlen.

Rational mathematical functions can be used to determine the course of the alkali quantity dosage, for example an entire n-degree rational function:

${\text{y = a}}_{\text{n}}{\text{· X}}^{\text{n}}{\text{+ a}}_{\text{n-1}}{\text{· X}}^{\text{n-1}}\text{+ ... a₁ · x + a₀}$

such as the following general quadratic equation:

$\text{y = ax² + bx + c}$

or a trigonometric function:

$\text{y = bsin ax + cx}$

Here mean

y

= amount of alkali to be dosed per unit of time

x

= Time

n, a, b, c,

= different or identical real numbers.

According to the invention, a step-by-step alkali metering is to be understood as a mode of operation in which the mode of addition for the alkali amounts over the entire metering period follows the course of a parabola, but in which the measures for metering take place in individual batches (e.g. analogous to the rhythm of a piston pump) or at that the rate of addition remains constant for a certain time (seconds or minutes) and then gradually changes to reduced or increased values. The alkali metering according to the invention can thus also proceed in such a way that certain constant units of quantity of the alkali are metered in at such a time cycle that the course of a parabola is observed over the entire metering period.

The alkali to be used for dye fixation according to the process can be an alkali hydroxide, carbonate, bicarbonate, phosphate, metaphosphate, pyrophosphate, polyphosphate or another alkaline substance or also a mixture of various of these alkalis, in particular the corresponding sodium compounds. The needed amount and selection of such alkalis depends on the type of reactive dye used or its reactive anchor and corresponds to the recipes customary in dyeing practice.

The process according to the invention leads to a surprisingly cheap, i.e. even course of dye fixation. This means that the dyeing process can be completed in a much shorter time than was possible according to the prior art and that one can still achieve excellent dye levelness.

For dyeing cellulose fibers or the cellulose fiber fraction of fiber mixtures according to the present invention, the organic dyes known under this generic term - regardless of the type of their fiber-reactive group - are considered as reactive dyes. This class of dyes is referred to in the Color Index, 3rd edition 1971 and additions in 1975 as "C.I. Reactive Dyes" and comprises chemical compounds with a dye character which are able to form a covalent bond with fibers containing OH groups. These are predominantly those dyes which contain at least one group which is reactive with polyhydroxyl fibers, a precursor therefor or a substituent which is reactive with the polyhydroxyl fiber. Particularly suitable as the base of the chromophoric system of these organic dyes are those from the series of the azo, anthraquinone and phthalocyanine compounds, it being possible for the azo and phthalocyanine dyes to be both metal-free and metal-containing.

Examples of reactive groups and precursors which form such reactive groups include epoxy groups, the ethyleneimide group, the vinyl grouping in the vinylsulfone or acrylic acid residue, also the β-sulfatoethylsulfone group, the β-chloroethylsulfone group or the β-dialkylamino-ethylsulfone group. Derivatives of the tetrafluorocyclobutyl series, for example tetrafluorocyclobutyl acrylic acid, are also suitable for this process. The reactive substituents in reactive dyes are those that are easily removable and leave an electrophilic residue. In this regard, 1 to 3 halogen atoms on the following ring systems are of interest as substituents: quinoxaline, triazine, pyrimidine, phthalazine, pyridazine and pyridazone. Dyes with several identical or different types of reactive groups can also be used, as can combinations of dyes of the same or different types. Such reactive dyes of the type defined above often have more than one sulfonic acid group (apart from that in the reactive group of the dye) in the molecule, which can be distributed as desired over the chromophore, but are preferably bound to its aromatic radicals.

Dyes of the vinyl sulfone type are preferably used for carrying out the claimed process, with which the fiber reacts via an addition mechanism via the vinyl sulfone form of the dye and which have either the vinyl sulfone residue itself or the β-sulfatoethyl sulfone group as reactive anchors. Also of value as coloring substances are those dyes which, in addition to a reactive residue of the vinylsulfone type or precursor thereof, additionally have at least one group which reacts with the cellulose according to the substitution mechanism, e.g. a monochlorotriazinyl or monofluorotriazinyl group.

Among the cellulose fibers to be dyed according to the invention are cotton, mercerized or leached cotton, conventional regenerated cellulose fibers, ^(R) modal fibers and other vegetable fibers, such as flat to understand. Likewise, the process according to the invention is suitable for mixtures of the abovementioned fibers with one another and with other fibers, such as, for example, polyester, polyamide, polyacrylonitrile fibers or silk.

The dyeing itself can be in the various processing stages or presentation forms of the textile material, such as As a flake, as a sliver, as a yarn, as a fabric, as a knitted fabric or as a fleece. All machines or apparatuses customary for such dyeings in the exhaust process can be used to carry out the new process.

The examples listed below serve to illustrate the invention and are not intended to restrict the claimed method in any way. The percentages contained therein relate to the weight of the objects so designated. The reactive dyes mentioned are used in commercial form and quality.

example 1

gelöst in etwas heißem Wasser, sowie 12,5 kg Glaubersalz zugegeben und man läßt den Warenstrang anschließend 5 min bis zur gleichmäßigen Verteilung dieser Zusätze unter gleichzeitiger Zirkulation der Behandlungsflüssigkeit laufen. Sodann wird bei weiterer Flottenumwälzung mit der Zudosierung von insgesamt 527 cm³ konz. Natronlauge (38°Bé) begonnen, wobei man den Dosiervorgang des Fixieralkalis portionsweise nach gleichen Zeitabständen folgendermaßen gestaltet: Dosierzeit 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 min^* Dosierungsrate 31 21 13 7 3 1 1 3 7 13 21 31 43 57 73 91 111 cm³/min * = Dosierzeit ab Beginn der Dosierung A jet dyeing machine is loaded with 25 kg of cotton weave and with 250 l of water at 40 ° C. to carry out a dyeing process at a liquor ratio of 1:10. The fleet thus prepared is now 0.5 kg of a reactive dye of the formula

dissolved in a little hot water, and 12.5 kg of Glauber's salt added and the product strand is then allowed to run for 5 minutes until these additives are evenly distributed, with the treatment liquid being circulated at the same time. Then, with further liquor circulation with the addition of a total of 527 cm³ conc. Sodium hydroxide solution (38 ° Bé) started, the metering process of the fixing alkali being carried out in portions at the same time intervals as follows: Dosing time 0 1 2nd 3rd 4th 5 6 7 8th 9 10th 11 12 13 14 15 16 min ^* Dosage rate 31 21st 13 7 3rd 1 1 3rd 7 13 21st 31 43 57 73 91 111 cm³ / min * = Dosing time from the start of dosing

During this measure, the temperature of the pull-out bath is kept constant at 40 ° C.

After the sodium hydroxide solution has been introduced, the textile material is dyed to the end for a further 20 min at the set temperature and this dyeing is then completed as usual by rinsing, acidifying, soaping and rinsing again. You get a gray color with very good levelness.

Examples 2 to 15

If, in the course of the dyeing process according to Example 1, instead of the reactive dye defined there by its structure, one of the reactive dyes mentioned below is used here and the other dyeing conditions are left unchanged, completely level dyeings are also achieved:

Example 16

If, instead of the cotton goods used there, a blended fabric of 30% polyester fibers and 70% cotton is used for pulling out according to the treatment recipe of Example 1, a completely level gray dyeing is obtained on the cotton component, in which the polyester fiber portion of the dye material is then also used with commercially available Disperse dyes can be over-dyed until a plain shade is set.

Example 17

hinzu. Darauf beginnt man bei Aufrechterhaltung der Temperatur von 50°C im zirkulierenden Bad mit der Zudosierung von insgesamt 8800 cm³ einer mit Wasser im Verhältnis von 1:10 verdünnten, konz. Natronlauge (38° Bé), wobei die nachfolgend beschriebene Dosierungsstaffelung eingehalten wird: Dosierzeit 0 4 8 12 16 20 24 28 32 36 min Dosierungsrate 125 80 45 20 5 0 5 20 45 80 cm³/min Dosierzeit 40 44 48 52 56 60 min Dosierungsrate 125 180 245 320 405 500 cm³/min 75 kg of cotton yarn in the form of packages are introduced into a yarn dyeing machine and the dyeing container is then filled with 750 l of water at 50.degree. 22.5 kg of Glauber's salt and a preparation of 500 g of a reactive dye of the formula dissolved in water are added to this liquor while the circulation pump is running

added. Then you start with maintaining the temperature of 50 ° C in the circulating bath with the addition of a total of 8800 cm³ one diluted with water in a ratio of 1:10, conc. Sodium hydroxide solution (38 ° Bé), the dosage scale described below is observed: Dosing time 0 4th 8th 12 16 20th 24th 28 32 36 min Dosage rate 125 80 45 20th 5 0 5 20th 45 80 cm³ / min Dosing time 40 44 48 52 56 60 min Dosage rate 125 180 245 320 405 500 cm³ / min

The textile material is then dyed for a further 15 minutes while the liquor cycle continues under the same temperature conditions and then finished as usual. A pink yarn dyeing is obtained which, after knitting, leads to completely level piece goods.

Example 18

If you follow the instructions for dyeing as described in Example 17, but using yarn consisting of a fiber mixture of 70% cotton and 30% of a polyester fiber pre-dyed with disperse dyes, you will also get a complete after the dyeing operation on the cotton portion of the goods level pink.

Example 19

welche vorher in 100 l heißem Wasser vorgelöst wurden, zugegeben sowie unter Rotation des strangförmig geführten Textilguts in dem Färbemedium verteilt. Nach weiterem 10-minütigen Lauf der Zirkulationsflotte bei derselben Temperatur werden dem Behandlungsbad dann noch 24375 cm³ einer durch Auflösen von 15 kg Soda in Wasser angesetzten Lösung des Fixieralkalis entsprechend dem folgenden Schema zudosiert: Dosierzeit 0 5 10 15 20 25 30 35 40 45 min Dosierungsrate 1200 675 300 75 0 75 300 675 1200 1875 cm³/min A jet dyeing machine is fed with 300 kg of cotton jersey and a fleet of 2700 l of water for dyeing after the pull-out process. After heating to 30 ° C., this bath is initially 110 kg of a reactive dye of the formula

which were previously dissolved in 100 l of hot water, added and distributed in the dyeing medium with rotation of the strand-guided textile material. After the circulation liquor had been run for a further 10 minutes at the same temperature, 24375 cm 3 of a solution of the fixing alkali prepared by dissolving 15 kg of soda in water were then metered into the treatment bath in accordance with the following scheme: Dosing time 0 5 10th 15 20th 25th 30th 35 40 45 min Dosage rate 1200 675 300 75 0 75 300 675 1200 1875 cm³ / min

After 30 minutes of running the textile strand under the set conditions, the treated tricot fabric is finished as usual. The product image of the orange color obtained in this way is flawless and does not matter.

Example 20

und nach 10 Minuten zwischenzeitlicher Zirkulation fernerhin noch 140 kg Kochsalz im Verlauf von 30 Minuten sowie in Form von 3 Portionen zugesetzt. Durch Heizen wird dann die Badtemperatur innerhalb von 30 Minuten auf 80°C getrieben. Während dieser Periode werden in den Färbeansatz 52896 cm³ einer wäßrigen Lösung, hergestellt aus 10000 g Soda und 10000 cm³ konz. Natronlauge (38° Bé), ratenweise entsprechend dem unten angegebenen Zeittakt eingebracht: Dosierzeit 0 2 4 6 8 10 12 14 16 18 min Dosierungsrate 133 37 5 37 133 293 517 805 1157 1573 cm³/min Dosierzeit 20 22 24 26 28 30 min Dosierungsrate 2053 2597 3205 3877 4613 5413 cm³/min A reel runner with liquor circulation is loaded with 100 kg of cotton lining material and filled with 2000 l of water. The liquor presented is now 3 kg of a reactive dye of the formula at room temperature

and after 10 minutes of intermittent circulation, 140 kg of table salt were also added over the course of 30 minutes and in the form of 3 portions. The bath temperature is then raised to 80 ° C. within 30 minutes by heating. During this period, 52896 cm³ of an aqueous solution made from 10,000 g of soda and 10,000 cm³ of conc. Sodium hydroxide solution (38 ° Bé), introduced in installments in accordance with the time interval specified below: Dosing time 0 2nd 4th 6 8th 10th 12 14 16 18th min Dosage rate 133 37 5 37 133 293 517 805 1157 1573 cm³ / min Dosing time 20th 22 24th 26 28 30th min Dosage rate 2053 2597 3205 3877 4613 5413 cm³ / min

On the goods colored in this way by pulling out, a completely level blue color is obtained after the customary post-treatment.

Example 21

welcher zuvor in 1 l heißem Wasser vorgelöst wurde, in diese Ausziehflotte ein, worauf letztere innerhalb von 30 min auf 80°C aufgeheizt wird und während dieser Zeit 11,2 kg Kochsalz portionsweise zugegeben werden. Separat davon hat man unterdessen als Fixieralkali 14,69 l einer wäßrigen Lösung angesetzt, welche 2820 g Soda enthält und die dann im Verlauf von 65 min im nachfolgend gezeigten Zeitrhythmus dem unter Fixierbedingungen befindlichen Färbebad zudosiert werden: Dosierzeit 0 5 10 15 20 25 30 35 min Dosierungsrate 201 113,5 51 13,5 1 13,5 51 113,5 cm³/min Dosierzeit 40 45 50 55 60 min Dosierungsrate 201 313,5 451 613,5 801 cm³/min 25 kg of cross-wound bobbins made of cotton yarn and 188 l of water are placed in a bobbin dyeing machine. After switching on the disposable circulation pump, 375 9 of a reactive dye of the formula are worn

which was previously dissolved in 1 l of hot water, into this pull-out liquor, whereupon the latter is heated to 80 ° C. within 30 minutes and 11.2 kg of sodium chloride are added in portions during this time. Separately, 14.69 l of an aqueous solution which contains 2820 g of soda have been prepared as fixative alkali and are then metered into the dye bath under fixation conditions over the course of 65 min: Dosing time 0 5 10th 15 20th 25th 30th 35 min Dosage rate 201 113.5 51 13.5 1 13.5 51 113.5 cm³ / min Dosing time 40 45 50 55 60 min Dosage rate 201 313.5 451 613.5 801 cm³ / min

After the alkali metering has ended, the textile material is dyed for a further 30 minutes at the same temperature and then finished as usual.

To assess the dyeing result, the yarn was wound from two dyed bobbins onto a fresh bobbin that the inner yarn layers of the first bobbin came to lie next to the outer yarn layers of the second bobbin. In this comparison, no nuance deviations could be determined, which proved a perfect level coloring.

Example 22

die man zuvor in 50 l heißem Wasser gelöst hat, über das Ansatzgefäß dem Behandlungsbad zugespeist werden. In diese Ausziehflotte läßt man daraufhin unter fortdauernder Zirkulation sowie bei gleichbleibenden Temperaturverhältnissen einen wäßrigen Alkaliansatz von 119,4 l Volumen, bestehend aus 9750 g Soda, 165 cm³ konz. Natronlauge (38° Bé) und Wasser, innerhalb von 65 Minuten nach dem in folgender Tabelle vorgeschriebenen Zugabemodus einfließen: Dosierzeit 0 5 10 15 20 25 30 min Dosierungsrate 723,5 326 87,5 8 87,5 326 723,5 cm³/min Dosierzeit 35 40 45 50 55 60 min Dosierungsrate 1280 1995,5 2870 3904 5096 6448 cm³/min In a jet dyeing machine, 500 kg of a round-knit tubular fabric, consisting of a mixture of 35% polyester fiber and 65% cotton, are loaded and 3100 l of water are let into the dye container so charged. With the circulation pump running, 65 kg of table salt are then added to the liquor presented and this is then heated to 50 ° C., after which 1620 g of a reactive dye of the formula

which have previously been dissolved in 50 l of hot water, are fed to the treatment bath via the preparation vessel. In this pulling-out liquor, an aqueous alkali batch of 119.4 l volume, consisting of 9750 g of soda, 165 cm 3 of conc., Is then left under constant circulation and at constant temperature conditions. Sodium hydroxide solution (38 ° Bé) and water, flow in within 65 minutes according to the addition mode specified in the following table: Dosing time 0 5 10th 15 20th 25th 30th min Dosage rate 723.5 326 87.5 8th 87.5 326 723.5 cm³ / min Dosing time 35 40 45 50 55 60 min Dosage rate 1280 1995.5 2870 3904 5096 6448 cm³ / min

After a further 30 minutes of dyeing time following the metering of the fixing alkali, the dyeing is completed as usual and then over-colored with commercially available disperse dyes. The nuance of the goods on the cotton component achieved in this way is immaterial.

Example 23

in 50 l heißem Wasser gelöst, welche dann in diesem Stadium des Behandlungsganges innerhalb von 10 Minuten der Flotte über die Kochwand zugegeben werden. Separat davon sind zwischenzeitlich 13,8 kg Soda mit Wasser gelöst und auf ein Volumen von 119 l aufgefüllt worden. Diese Lösung wird anschließend über ein Verteilerrohr in das unter Fixierbedingungen befindliche Färbebad entsprechend dem unten angegebenen Schema eingetragen: Dosierzeit 0 10 20 30 40 50 60 70 80 90 min Dosierungsrate 500 150 0 150 300 600 1200 2000 3000 4000 cm³/min 92 kg of a cotton jersey mercerized as yarn are loaded in a reel runner without liquor circulation, the latter is filled with 1230 l of water and 69 kg of Glauber's salt are added and the liquor temperature is brought to 90 ° C with the reels running. In the meantime, regardless of the treatment vessel, there is 1840 g of a reactive dye of the formula

dissolved in 50 l of hot water, which are then added to the liquor via the cooking wall within 10 minutes at this stage of the treatment course. Separately, 13.8 kg of soda have since been dissolved with water and made up to a volume of 119 l. This solution is then introduced via a distributor pipe into the dye bath under fixing conditions according to the scheme below: Dosing time 0 10th 20th 30th 40 50 60 70 80 90 min Dosage rate 500 150 0 150 300 600 1200 2000 3000 4000 cm³ / min

The coloring is complete after the dosing of the fixing alkali has been completed and is subjected to the aftertreatment as usual. The resulting blue-colored goods are perfectly level.

Example 24

600 g des Farbstoffes Reactive Orange 16 mit der C.I.-Nr. 17757 und 900 g des Farbstoffes Reactive Blue 19 mit der C.I.-Nr. 61200, die man zuvor in 50 l Wasser gelöst hat, bei laufender Umwälzung der vorgelegten Flotte zugegeben. Zur Farbstoff-Fixierung setzt man außerhalb des Färbegefäßes eine alkalische Fixierflüssigkeit an. Dazu werden 2 l konz. Natronlauge (38° Bé) mit Wasser auf ein Volumen von 24,6 l verdünnt, in einen Ansatzbehälter gegeben und der auf Färbetemperatur erwärmten Zirkulationsflotte nach folgendem Schema zudosiert: Dosierzeit 0 2 4 6 8 10 12 14 16 18 20 min Dosierungsrate 720 320 80 0 80 320 720 1280 2000 2880 3920 cm³/min A jet dyeing machine is loaded with 50 kg of cotton jersey. Then 430 l of water are poured into the dye container and 40 g of table salt are added; the temperature of the bath is 40 ° C. Then a mixture of 900 g of a reactive dye of the formula

600 g of the dye Reactive Orange 16 with the CI no. 17757 and 900 g of the dye Reactive Blue 19 with the CI no. 61200, which had previously been dissolved in 50 l of water, was added to the submitted liquor while the circulation was ongoing. To fix the dye, an alkaline fixing liquid is used outside the staining vessel. For this, 2 l conc. Sodium hydroxide solution (38 ° Bé) diluted to a volume of 24.6 l with water, placed in a batch container and added to the circulation liquor heated to the dyeing temperature according to the following scheme: Dosing time 0 2nd 4th 6 8th 10th 12 14 16 18th 20th min Dosage rate 720 320 80 0 80 320 720 1280 2000 2880 3920 cm³ / min

The dosing is done by means of an electropneumatically controlled air pressure pump. The connected processor controls the dosing process according to the selected curve. The pressure side of the metering pump is connected to the suction side of the liquor circulation pump.

After 30 minutes of remaining dyeing time under the set conditions, the dyeing is finished, the dyed goods are rinsed as usual and washed hot. The levelness of the brown color obtained in this way is excellent.

Claims (7)

1. A process for the level dyeing of textile material made of cellulose fibers in an aqueous medium by the exhaust method with reactive dyes which are fixable under alkaline conditions, in which the alkali required for dye fixation is added a little at a time to the dyebath, which contains the material to be dyed, at least one such dye and, if appropriate, all other ingredients but no fixing alkali, at the fixation temperature over a predetermined period of the exhaustion phase in a predetermined amount per unit time, wherein the addition of alkali is effected in the manner of a parabolic function by starting initially continuously or portionwise with the addition of at least 1/400 of the total amount of alkali, whereupon the rate of addition for these amounts of alkali is gradually reduced to a minimum approaching or equal to zero in order finally to increase again through continuous or portionwise addition to the liquor of further amounts which increase per unit time until the total amount of alkali required for the fixation of the particular reactive dyes has been added during the exhaustion phase.
2. The process as claimed in claim 1, wherein the addition of alkali is started at a first rate corresponding to 1/15 to 1/400, preferably 1/15 to 1/73, of the total amount of the alkali required for dye fixation, the rate of addition then decreases in an amount to reach the minimum value after not more than 20 minutes and from then on continuously increases again in amount and finally, in conformity with the time required during the exhaustion phase for the addition of alkali, reaches its maximum value.
3. The process as claimed in at least one of claims 1 to 2, wherein the rate of addition for the amounts of alkali remains constant for a certain portion of the period of the exhaustion phase envisaged for the addition of alkali and then incrementally changes to quantitively reduced or increased values per unit time.
4. The process as claimed in at least one of claims 1 to 3, wherein the addition of alkali is automatically program-controlled.
5. The process as claimed in at least one of claims 1 to 4, wherein the addition of alkali takes place at constant temperature.
6. The process as claimed in at least one of claims 1 to 5, wherein the reactive dyes used are those which have a reactive attachment system of the β-sulfatoethylsulfonyl or vinylsulfonyl type.
7. The process as claimed in at least one of claims 1 to 6, wherein the textile material which contains cellulose fibers is present as a mixture with polyester, acrylic or polyamide fibers or with silk.