EP0058432B1 - Process for the continuous dyeing of wool fibres - Google Patents

Description

The present invention relates to the continuous and uniform fast dyeing of wool fibers with reactive dyes containing sulfo groups in the presence of alkali acetate in an aqueous dye liquor after a pad-steaming process without intermediate drying.

The continuous dyeing of wool fibers, especially in the form of sliver, threads, bundles of yarn, but also fabrics, with reactive dyes without the use of textile auxiliaries or without being forced to work with two-phase dyeing liquors, has not yet been possible with the for carry out the necessary safety and reproducibility of the nuance. On the one hand, it is the steaming times which take too long for an economical, energy-conscious dye fixation; on the other hand, in the previously known dyeing processes, this always results in high amounts of waste water contaminated with surface-active products, the treatment of which is rather cumbersome and also costly.

For example, it is known from DE-C-2244524 to process wool comb with the help of Vigoureux printing into uniformly colored melanges, the authenticity properties of the color effects which can be achieved in this way being superior to those of other dye classes primarily because of the reactive dyes used. The steam times for dye fixation - exposure times at 100-102 ° C from 15 to 40 minutes are recommended for Vigoureux printing - can be described as short for the technical development at that time. However, in the known process for full fixation of the reactive dyes, urea as a solubilizer and at the same time as a fixing aid must also be added to the printing pastes; an acetic acid / sodium acetate buffer serves to adjust the pH.

Furthermore, a sample printing process for wool is explained in the sample card Hoe 2990 "®REMAZOL dyes for printing by Hoechst AG, Frankfurt / Main, in which reactive dyes of the vinylsulfone type, together with sodium acetate and urea, are printed on woolen fabric, dried and fixed for fixing be steamed in saturated steam. The latter recipe prescribes urea quantities of 150 to 200 g / kg printing paste for the purpose of deepening the color.

In contrast to this, in the wool application area, continuous dyeing of yarn by dye impregnation and fast-acting fixation has so far only been possible in the treatment of a single thread, but not in the case of comb drawing, thread coulters and yarn bundles. Unless, in such an examination, all continuous dyeing processes of wool fibers are included, which are either aimed at the use of specific dyes which compensate for the affinity differences within the wool fibers, such as, for. B. methyltaurino-ethyl sulfone reactive dyes according to DE-C-23 40 044, where from a neutral or only slightly different medium and without intermediate drying is carried out by a steam fixing method and the impregnated solder to prevent the gray haze on the dyeings produced a mixture of anionic and non-ionic surfactants must be added; or the above-mentioned check also extends to continuous dyeing techniques which are carried out under the influence or in the presence of textile auxiliaries or substances having a similar effect. This subheading also includes products that allow working in two-phase dyeing liquors. Processes in the category discussed above involve a high level of water consumption and therefore require a lot of energy and a correspondingly large amount of labor. Today, however, energy savings and easy-to-remove wastewater play an important role.

The invention explained below is based on the object of eliminating the disadvantages of the known processes for the continuous dyeing of wool fibers with sulfo-containing reactive dyes in relation to the length of the dyeing time, and in particular to shorten the steaming time. In addition, the mandatory use of textile auxiliaries should be as low as possible, so that the emission of such polluted wastewater is largely reduced.

This object is achieved in that a liquor is used to block the fiber material which, in addition to the dissolved dyes, only contains 20 to 50 g / l, preferably 30 to 40 g / l sodium acetate and optionally a reducing agent, and after removing the Excess liquor the wet padding for dye fixation for 5 to 13 minutes, preferably 9 to 12 minutes, the action of saturated steam at temperatures of 102 ° to 115 ° C.

The feasibility of the new process is based on the principle of adding large amounts of sodium acetate to the padding liquor combined with a subsequent short-term steaming process without prior drying of the padding with the reactive dyes. Here, the concentration of sodium acetate is such that it is present in the dye preparation in a clear excess based on the amount that would be required for the setting and maintenance of weakly acidic to neutral pH conditions. Under this condition, the method of operation according to the invention allows the wool material to be continuously dyed without the involvement of additional textile auxiliaries or solubilizers.

The claimed pad dyeing technique is characterized above all by the fact that a very high color strength of the process products is achieved. The product image available in this way is Excellent, this results in up to 100% greater color yields than with the previously usual methods for continuous wool dyeing. The level of authenticity that can be achieved with the high color strength of the dyeings must be regarded as surprising. The extraordinarily good fastness properties result from the covalent bond between dye and wool fiber that takes place within a very short time, which in turn has its origin in the use of sodium acetate. In order to achieve the high level of authenticity described, no additional measures such as pH control etc. need to be taken, so that the implementation of the method described is very simplified.

In relation to the present invention, it was astonishing and was not expected even by a person skilled in the art that when using 20 to 50 g / l of sodium acetate, depending on the color depth, the course of the reaction of the fixing operation, which is known per se in the scheme, is accelerated so that in this case allows continuous process control. However, this also means that - because large amounts of sodium acetate are available - these then make a direct contribution to the fixation of the dyes used and, consequently, the steaming times required for this can be kept low.

Likewise, it was not easy to predict that the colors would be extremely unimportant under these conditions. In Textile Practice 1971, pages 164-167, in particular 167, it is emphasized that the levelness of dyeing wool with reactive dyes becomes better as the pH decreases, and does so significantly better. It was simply in no way obvious that the sodium acetate, which reacted in a clearly alkaline manner in these quantities, could be obtained at all.

Fiber damage does not occur in the course of the dyeing process according to the invention, although the pH of the padding liquor is about 9 at the start of the treatment. Firstly, the exposure time in this environment is very short, it is only a few seconds, and immediately after the goods enter the steamer, acetic acid is released, which then shifts the pH value to weakly acidic. At the end of the steam treatment, however, the padding liquor medium is shifted back to alkaline, but this state also only lasts for a few seconds and at the same time replaces an alkaline aftertreatment of the dyeings produced.

The specific type of constraints makes it possible to dispense with the leveling agents that are usually used for dyeing wool. You still get very uniform colors. Of course, certain circumstances can make the presence of small amounts of such aids in the padding fleet appear advantageous. However, these are not of crucial importance for the practicability of the new method in practice. However, such an addition does not do any harm and in no way has a negative effect on the fastness properties of the wool dyeings produced in this way. If necessary, adding urea, for example, is in no way disturbing as long as it remains within the limits where wool damage is not to be feared. Previous continuous or semi-continuous dyeing processes, on the other hand, have prescribed the use of 80 g / l urea as the minimum minimum amount; the maximum amount in this regard is up to 300 g / l. Clearly longer steaming times are required in all such known methods.

A very special advantage under the given conditions is the stability of the padding liquors, which is over 24 hours in this very weakly alkaline environment. This makes the entire dyeing process easier to handle.

However, the padding liquors used according to the invention can additionally contain thickeners, so that they can also be used for Vigoureux printing due to the more viscous consistency set in accordance with a modification of the present invention. The rest of the procedure, in particular the measures for dye fixation, remains the same.

As fiber material for the claimed process, wool fibers are particularly suitable in the form of sliver, yarn, thread sheets and bundles of yarn, but also fabrics. Of course, individual threads can also be treated in this way, but the effectiveness of the method is questioned in this case. The new process is also suitable for dyeing the wool content of fiber blends.

The dyeing technique according to the present invention can also be applied to wool fibers which have been subjected to a "felt-free _" finishing process - such wool is generally referred to as "superwash-treated wool" a polyimine or polyacrylic resin film (as described in Melliand Textile Reports 9/1971, page 1100, or in the Journal of the Society of Dyers and colors, Volume 88, Number 3/1972, pages 93-100) The textile article made therefrom must withstand the hard stresses not required and not attained with normal wool, such as repeated washing at 60 ° C with the use of household detergents containing perforates, without matting, and consequently must also be color-fast. Such requirements at this high level of authenticity especially in the fastness to washing and sweating, he is primarily from dyeings with reactive dyes enough.

With wool treated in this way without felting, the results obtained in the dyeing according to the invention are as good as with normal wool. This fact is surprising in that the felt-free finished wool has a different drawing power than the untreated wool fibers demonstrate. Nevertheless, this different behavior does not require special consideration when creating a coloring recipe. This makes the new process the only one of its kind to date, in which the same depth of color and the same levelness can be achieved on both finished and non-finished wool fibers according to one and the same rule.

For dyeing the wool fibers or the wool portion of fiber mixtures according to the present method, the organic dyes known under this term - regardless of the type of their reactive group - come into consideration as reactive dyes. This class of dyes is referred to in the Color Index, 3rd edition 1971 as “reactive dyes. These are predominantly those dyes which contain at least one group which is reactive with the amino groups of polyamide fibers, a preliminary stage therefor or a substituent which is reactive with the amino groups of polyamide fibers. Particularly suitable as the basic body of the organic dyes are those from the series of the azo, anthraquinone and phthalocyanine dyes, it being possible for the azo and phthalocyanine dyes to be both metal-free and metal-containing. Reactive groups and precursors which form such reactive groups include, for example, epoxy groups, the ethyleneimide group, the vinyl grouping in the vinylsulfone or acrylic acid radical, also the β-sulfatoethylsulfone group, the β-chloroethylsulfone group or the β-dialkylamino-ethylsulfone group. In addition, derivatives of the tetrafluorocyclobutyl series, e.g. B. the tetrafluorocyclobutyl acrylic acid in question. The reactive substituents in reactive dyes are those that are easily removable and leave an electrophilic residue. Examples of suitable substituents are 1 to 3 halogen atoms on the following ring systems: quinoxaline, triazine, pyrimidine, phthalazine, pyridazine and pyridazone. Dyes with several identical or different types of reactive groups can also be used. Such reactive dyes of the type defined above often have more than one sulfonic acid group (apart from the reactive component of the dye) in the molecule, which can be distributed as desired over the chromophore, but are preferably bound to its aromatic radicals. Based on the color yields achievable with conventional exhaust processes, the dyes mentioned above give very good yields on wool in the case of the continuous process according to the invention.

The claimed process has proven to be superior to the known dyeing methods in which acetic acid (e.g. 25-35 g / l 60% acetic acid) or acetic acid together with urea instead of sodium acetate has been added to the padding liquor. The steaming times of these previous methods are usually much longer and the resulting color strength is almost always up to 50% weaker than when working with sodium acetate.

DE-A-2057400 also relates to a continuous process, according to which besides printing also the block dyeing of textile material made of non-chlorinated wool with reactive dyes including dye fixation - expediently after preliminary drying - is described by steaming with saturated steam. Although it is evident from the recipe of the exemplary embodiments there that, in addition to a not insignificant addition of urea, the printing pastes or pad liquors used in accordance with this prior art also contain sodium acetate in such a high concentration as in the process according to the invention, the difference is based on Present invention this known dyeing technique in particular on the mandatory use of auxiliaries with a surface-active effect, for. B. fatty acid polyglycol esters, in amounts of 2 to 10 wt .-%. The presence of the last-mentioned substances is primarily aimed at making the pretreatment of the fiber material by chlorine, which is otherwise necessary to achieve full and deep colors with good brilliance, unnecessary. However, the inevitable involvement of aids of the type mentioned above is avoided by the method of operation according to the invention.

example 1

• 16 g des Reaktivfarbstoffs der Formel
  
  und
• 40 g Natriumacetat enthält. Dieser Klotzflotte werden außerdem noch 10 g/I m-nitrobenzolsulfonsaures Natrium als Reduktionsschutzmittel zugesetzt.

Woolen fabric made of non-finished woolen fibers in plain weave is padded with an aqueous liquor at a block temperature of 25 ° C and a liquor absorption of 105% (by weight of the dry goods), which is a solution in liters

• 16 g of the reactive dye of the formula
  
  and
• Contains 40 g sodium acetate. In addition, 10 g / l of sodium m-nitrobenzenesulfonic acid are added to this padding liquor as a reducing agent.

Without intermediate drying, the still moist fiber material is passed through a damper immediately after the padding process and steamed there for 12 minutes in saturated steam at 130 ° C.

• 1 g/I eines nichtionischen Waschmittels enthaltend 30 Gew.-% eines Umsetzungsproduktes von 1 Mol Stearylamin mit 12 Mol Ethylenoxid, und
• 1,5 ml/I Ammoniak (pH 8,5)

5 Minuten lang bei 55 °C geseift. Zuletzt wird die gefärbte Ware nochmals warm und kalt mit Wasser gespült.The textile material treated in this way is then rinsed first with cold water, then with water at 40 ° C. and finally in an aqueous bath with the addition of

• 1 g / l of a nonionic detergent containing 30% by weight of a reaction product of 1 mol of stearylamine with 12 mol of ethylene oxide, and
• 1.5 ml / l ammonia (pH 8.5)

Soaped at 55 ° C for 5 minutes. Finally, the dyed goods are rinsed warm and cold with water.

You get a very strong color in a reddish yellow.

A dyeing carried out parallel to the above procedure, in which the entire amount of sodium acetate used there has been replaced by 25 ml of acetic acid (60%), has only resulted in a 50% lighter (weaker) shade compared to the result there.

The same dyeing results as in the example according to the invention are obtained, however, if the wool material is padded according to the present recipe (in the presence of sodium acetate), but is then steamed for 10 minutes at 106 ° C.

Example 2

• 16 g des Reaktivfarbstoffs der Formel
  
  45 g Natriumacetat und
• 8 g m-nitrobenzolsulfonsaures Natrium enthält.

Knitted fabric made of chlorinated wool fibers is padded with an aqueous liquor at room temperature and a liquor absorption of 95% (by weight of the dry fabric), which is in liters

• 16 g of the reactive dye of the formula
  
  45 g sodium acetate and
• Contains 8 g of sodium m-nitrobenzenesulfonate.

The still moist fiber material is then immediately passed through a damper and steamed there at 110 ° C. for 9 minutes. The colored goods are aftertreated as in Example 1. A strong, brilliant orange color is obtained.

An analogous coloring, but using 150 g / l urea together with 25 ml / l acetic acid (60%) instead of 45 g / l sodium acetate, results in a shade which is at least 50% lighter in comparison to the example according to the invention.

Example 3

• 20 g des Farbstoffs Reactive Blue 19 mit der C.I.-Nr. 61200,
• 35 g Natriumacetat und
• 9 g m-nitrobenzolsulfonsaures Natrium.

Wool yarn made from non-chlorinated wool is padded in the form of parallel bundles of yarn at a pad temperature of 30 ° C and a liquor absorption of 90% (by weight of the dry goods) by dipping and squeezing three times with an aqueous liquor which contains 1 liter

• 20 g of the dye Reactive Blue 19 with the CI no. 61200,
• 35 g sodium acetate and
• 9 g of sodium m-nitrobenzenesulfonic acid.

The still moist fiber material is immediately passed through a steamer without intermediate drying and steamed there at 115 ° C. for 7 minutes. After a subsequent, cold and warm rinsing with water, an aftertreatment is carried out as described in Example 1. A navy blue dyeing is obtained on the yarn.

If, instead of the 35 g sodium acetate, a mixture of 150 g / l urea and 25 ml / l acetic acid (60%) is used in the padding liquor described above and the dyeing operation is carried out as described above, dyed yarn in bright blue is obtained. which means in comparison to the example according to the invention a shade which is weaker in color.

Example 4

• 16 g des Reaktivfarbstoffs der Formel
  
  50 g Natriumacetat und
• 10 g m-nitrobenzolsulfonsaures Natrium enthält.

Chlorinated wool fabric (plain weave) is padded with an aqueous liquor at room temperature and a liquor absorption of 100% (by weight of the dry goods), which is in liters

• 16 g of the reactive dye of the formula
  
  50 g sodium acetate and
• Contains 10 g of sodium m-nitrobenzenesulfonate.

The still moist wool material is then steamed in a steamer at 102 ° C. for 13 minutes without intermediate drying and aftertreated as described in Example 1. A strong red color is obtained.

Example 5

• 9,1 g/I des Farbstoffs aus Beispiel 2,
• 5,7 g/I des Farbstoffs aus Beispiel 3,
• 3,4 g/I des Farbstoffs Reactive Black 5 mit der C.I. Nr. 20505 und
• 0,31 g/I des Reaktivfarbstoffs der Formel

The procedure is as in Example 4, the padding liquor here containing a combination of the dyes of the following formulas and amounts:

• 9.1 g / l of the dye from Example 2,
• 5.7 g / l of the dye from Example 3,
• 3.4 g / l of the dye Reactive Black 5 with CI No. 20505 and
• 0.31 g / l of the reactive dye of the formula

The type and amounts of the additives and the implementation of the process can also be found in Example 4. A deep, flowery black is obtained on the wool fabric.

If the procedure is otherwise the same, but instead of sodium acetate here using 150 g / l urea with 25 ml / l acetic acid (60%), a coloration is obtained which is about 50% weaker compared to the example according to the invention.

Example 6

• 15 g des Farbstoffs Reactive Red 4 mit der C.L-Nr. 18105 und
• 45 g Natriumacetat enthält.

The wool comb, which has been equipped with a polymer-free polyamide-epichlorohydrin, is padded with an aqueous liquor at room temperature and a liquor absorption of 110% (by weight of the dry goods), which is in liters

• 15 g of Reactive Red 4 dye with CL no. 18105 and
• Contains 45 g sodium acetate.

In addition, 10 g of sodium m-nitrobenzenesulfonic acid are added to the padding liquor as a reducing protection agent.

• 1 g/I eines nichtionischen Waschmittels enthaltend 30 Gew.-% eines Umsetzungsprodukts von 1 Mol Stearylamin mit 12 Mol Ethylenoxid, und
• 1,5 mi/I Ammoniak (pH 8,5)

5 Minuten lang bei 55 °C geseift. Anschließend wird die gafärbte Ware nochmals warm und kalt mit Wasser gespült. Man erhält eine sehr kräftige Rotfärbung.Without intermediate drying, the still moist fiber material is now immediately after the padding process passed through a damper and steamed there for 11 minutes at 102 ° C for dye fixation. Thereupon the textile material treated no is rinsed first with cold water, then with water at 40 ° C. and then in an aqueous bath with the addition of

• 1 g / l of a nonionic detergent containing 30% by weight of a reaction product of 1 mol of stearylamine with 12 mol of ethylene oxide, and
• 1.5 ml / l ammonia (pH 8.5)

Soaped at 55 ° C for 5 minutes. Then the dyed goods are rinsed with water again, warm and cold. A very strong red color is obtained.

Example 7

• 16 g des Reaktivfarbstoffs der Formel
  
• 50 g Natriumacetat und
• 10 g m-nitrobenzolsulfonsaures Natrium enthält.

Wollkammzug is padded at room temperature and a liquor absorption of 100% (by weight of the dry goods) with an aqueous liquor, which is in liters

• 16 g of the reactive dye of the formula
  
• 50 g sodium acetate and
• Contains 10 g of sodium m-nitrobenzenesulfonate.

Without intermediate drying, the still moist wool material is steamed for 6 minutes at 115 ° C immediately after padding. The post-treatment of the goods so dyed is carried out as in Example 6. The result is a strong, clear blue color.

Claims (6)

1. A process for the continuous and uniform fast dyeing of wool fibers with reactive dyes containing sulfo groups, in the presence of an alkali metal acetate and in an aqueous dye bath according to a pad steaming method without applying an intermediate drying, characterized in that for the padding operation of the wool fiber material a dyebath is used containing sodium acetate in the range of from 20 to 50 g per liter of liquor and optionally an anti-reducing agent in addition to the dissolved dyestuffs, and after removing of excess liquor, said moist pad dyeing is subjected to a treatment with saturated steam at a temperatur in the range of from 102 to 115 °C for to 13 minutes, to fix the dyestuffs.

2. A process according to claim 1, characterized in that the amount of sodium acetate is in the range of from 30 to 40 g per liter of the padding liquor.

3. A process according to claims 1 or 2, characterized in that the padding liquor additionally contains sodium m-nitrobenzene sulfonate.

4. A process according to one or several of the claims 1 to 3, characterized in that the time of treatment with steam is 9 to 12 minutes.

5. A process according to one or several of the claims 1 to 4, characterized in that wool fibers in form of slubbing, yarn, warp and yarn bundles are dyed.

6. A process according to one or several of the claims 1 to 5, characterized in that wool fibers having an antifelting finish in the form of a coating layer of a polyimine resin or a polyacrylic resin are dyed.