DE4208757A1 - METHOD FOR COLORING TEXTILE MATERIALS FROM CELLULOSE FIBERS - Google Patents

Abstract

A process is disclosed for dyeing and printing on textiles made from cellulose fibres or from mixtures of cellulose and other fibres, in an aqueous bath with pH values in excess of 12 and at temperatures of at least 100 DEG C. Use is made of vat dyes without the usual reducing agents for such dyes, in concentrations of alkali hydroxide in the bath of between 20 and 500 ml of aqueous alkaline lye at 38 DEG Bé per litre of bath, dyeing being finished in the normal way.

Description

The invention relates to a method for dyeing textiles Materials made from cellulose fibers or cellulos contain fibers mixed with synthetic fibers in aq small liquor at pH values above 12 and temperatures of at least 100 ° C with combinable dyes.

When dyeing cellulose fibers with vat dyes, esp especially with indigo, Na is used as the reducing agent triumdithionite (hydrosulfite), thiourea dioxide (Formami dinsulfinic acid) or hydroxyacetone. Works in all cases one in the presence of alkali and at pH values of at least 12. Sodium dithionite and thiourea dioxide are very effective same reducing agents, but also have disadvantages. So leads for example the use of hydrosulfite or thiourine Dioxide during dyeing with a pollution of the wastewater Sulfite and sulfate ions.

From DE-A-2 10 11 387 it is known in the vat coloring of Textiles containing cellulose fibers thiourea dioxide to use as a reducing agent. The reduction of the vat dyes can additionally in the presence of glucose be taken to prevent sensitive dyes be reduced too much.

EP-A-03 64 752 describes a process for dyeing Cel loose fibers with vat dyes in alkaline-aqueous Me dium known, in which mixtures are used as reducing agents from, for example, sodium dithionite and α-hydroxycarbonyl connections, e.g. B. hydroxyacetone, in weight ratio nis 1: 1 to 1:15 and the coloring at pH values of at least 13 and at temperatures above 75 ° C carries out.

From EP-A-03 57 548 is also a process for dyeing ben of textile materials made of cellulose fibers with vat dyes in the presence of reducing agents and alkali is known in which one for the reduction of vat dyes En  diols used and also organic, mixed with water bare solvents such as alcohols, acetone, cyclohexanone, forma mid or acetamide. As from the last two dis cut literature is required for si cheren reduction of vat dyes, especially In digo, additionally with α-hydroxycarbonyl compounds other component. Provided you reduce the vat color makes substances alone with α-hydroxycarbonyl compounds, Precipitation occurs again and again when dyeing in practice of not completely reduced dyes, in particular reoxidized indigo.

DE-B-2 11 64 463 describes a process for dyeing and loading known to print textile materials with vat dyes, in which the reduction of vat dyes in aqueous Medium at a pH of at least 12 with hydroxyacetone in the presence of quinoid compounds under Coloring conditions are water soluble.

As can be seen from the prior art described above, is used in the known dyeing processes with vat dyes the insoluble pigment pigment into the reduced, water to transfer soluble leuco compound. Only this Leukover bond is drawn onto the cellulose fibers and is there after of the reoxidation as a pigment.

The present invention is based, ge a verbes compared to the prior art described above sertes procedure for dyeing cellulosic fibers to make available dyes that are ecological is cheaper than the known methods. The sewage from The dyeing should not with sulfur compounds to the same extent gen or organic compounds as the Ab water that occurs in the usual vat coloring processes.

The object is achieved with a method for dyeing and printing textile materials made from Cellulose fibers exist or cellulose fibers in a mixture contained with other fibers, in an aqueous liquor at pH ten above 12 and temperatures of at least 100 ° C. with combinable dyes if you are dyeing in absentia unit of the usual reducing agents for the viable color  substances with a concentration of alkali hydroxide in the Liquor of 20 to 500 ml of aqueous alkali metal solution 38 ° Be / l Carried out liquor and then staining in the usual Way completed.

The textile materials consist of cellulose fibers or contain cellulose fibers mixed with other fibers. They can be in any processing state, e.g. B. as Flake, card sliver, yarn, skein, fabric or knitted fabric. At The cellulose fibers can either be natural or regenerated cellulose such as rayon, viscose or poly trade nosic fibers. According to the method according to the invention can be both mercerized cotton and raw cotton as well as raw yarn, which is available as a package or as a strand, be colored. Synthetic fibers mixed with cellulo fibers in the textile materials are included for example polyester fibers, polyacrylonitrile fibers or syn aesthetic polyamide fibers.

The cellulose fibers are with viable dyes such as Vat dyes, especially indigo, or sulfur dye fabrics dyed. The vat dyes are either indigo or anthraquinone or indigoide Dyes. Vat dyes and sulfur dyes have been around since long available in the trade and in the Color Index (C.I.) docu mented, cf. Color Index, 3rd edition 1971, Volume 3, Sei ten 3719 to 3844 and volume 4, C.I. 58000 to 74000, Soc. Dyers and Coluristes, England.

The viable dyes are in the invention Process used in the amounts usual for dyeing sets, e.g. B. in the range of 0.01 to 10 wt .-%, based on the textile material. You can only use one or a mixture of 2 or more viable dyes insert fen. The dyeing of the textile materials can for example from a long aqueous fleet at a fleet ver Ratio from 1: 5 to 1:40, preferably 1: 8 to 1:20, successful gene, or also in the continuous process, for. B. Block process. Here one works with fleet ratios of 1: 0.5 up to 1: 3. The printing of textile materials is also possible by the method according to the invention.  

The pH of the aqueous liquors is above pH half of 12. It is made by adding alkali metal hydroxides to aqueous coloring medium adjusted. Suitable alkali hydroxides are sodium hydroxide and potassium hydroxide, the uses tion of sodium hydroxide solution is preferred as the alkali hydroxide. The Concentration of the alkali hydroxide in the aqueous dye liquor is 20 to 500, preferably 40 to 300 ml aqueous alkali solution 38 ° Be / l liquor. For most practical Applications are alkali hydroxide amounts of 40 to 80 ml of aqueous alkali hydroxide 38 ° Be per liter of liquor chatting.

The textile materials are used for dyeing in the aqueous-al Kali fleet introduced that have at least one viable Ren dye and possibly other usual coloring aids ent holds. According to the invention, the dyeing is carried out with the viable Dyes in the absence of the usual reducing agents for these dyes at temperatures of at least 100 ° C, before preferably at temperatures from 110 to 160 ° C. In most In some cases, the dyeing temperatures are in the range of 120 up to 135 ° C. Due to the high dyeing temperatures, the Dyeing in closed, pressure-tight dyeing machines be performed. The pressure to be considered apparatuses are known. Compared to the well-known Küpenfär The process is required in the process of the invention a higher amount of alkali hydroxide. Among the be written staining conditions, d. H. Temperatures of at least at least 100 ° C and a relatively high amount of alkali hydroxide, the combinable dyes - surprisingly without the addition of the usual reducing agents required for this - converted into the leuco form, which in the aqueous alkaline Fleet is soluble and on the cellulose fibers of the textile Materials. Studies on the reaction me mechanism of formation of leuko compounds from the conn dyes are not yet available.

The dyeing can be carried out at the same time as leaching the texti len materials made of cellulose fibers can be combined. Au It is also possible to use textile materials made from cellulose sern, whose warp threads are sized with starch, without stain prior removal of the sizing film. While the dyeing process is replaced by a slip films from the warp yarns of the fabrics, so that also a  It is possible to dye the warp yarns. Besides, it did proven to be advantageous, the inventive method in Perform presence of polysaccharides, e.g. B. cellulose, Starch and degraded starch. As cellulose, the dye bad is added, paper or wood pulp can ver be applied.

To accelerate the dyeing process, has it has proven advantageous in some cases that dyeing or printing additionally in the presence of chi noiden compounds that perform at pH values above out of 12 are water soluble. These connections are among the Dyeing conditions dissolved in the aqueous liquor. Suitable chi noide connections that are suitable for this are out the DE-B-21 64 463 described above. Quinoids Compounds are, for example, hydroxy, carboxylic acid and / or derivatives of benzochi containing sulfonic acid groups nons, naphthoquinones, acenaphthoquinones or anthraquinones, such as hydroxyanthraquinones, e.g. B. 2-hydroxyanthraquinone and 1,4-dihydroxyanthraquinone, anthraquinone carboxylic acids, Anthra quinonesulfonic acids, such as anthraquinone-2-sulfonic acid and 1,4-diaminoanthraquinone-2-sulfonic acid. These connections are common as accelerators in vat dyeing. The chi noiden compounds are used in amounts of 1 to 10 wt .-%, based on the amount of dye used puts.

The alkaline aqueous dyeing liquor can besides at least one egg nem dockable dye additionally polymers of mono ethylenically unsaturated carboxylic acids as coloring aids contain. Such coloring aids are, for example, from DE-B-24 44 823 known. It is in the we noticeably about homo- and copolymers of monoethylenic unsaturated carboxylic acids. The copolymers contain at least 10% by weight of a monoethylenically unsaturated Polymerized carboxylic acid. Individual connections of this Type are, for example, polyacrylic acid, polymethacrylic acid, Copolymers of acrylic acid and acrylamide, copolymers from acrylic acid and acrylonitrile, methacrylonitrile, acrylic acid esters, methacrylic acid esters and / or methacrylic acid esters. Copolymers of acrylic acid and Ma are also suitable linseic acid, copolymers of acrylic acid and itaconic acid, Copolymers of maleic acid and vinyl esters, copolymers  sate from maleic acid and vinyl ethers. What is essential is single Lich that the copolymers at least 10, preferably at least 50 mol% of a monoethylenically unsaturated car contain copolymerized bonic acid. The copolymers can NEN in the form of the free acids or preferably already form neutralized with alkali lye as dyeing aid be used. The K values of the homopolymers and copolymers monoethylenically unsaturated carboxylic acids are 15 to 90 and are preferably in the range of 20 to 65. Die K values are determined according to H. Fikentscher, Celluloseche mie, vol. 13, 58-64 and 71-74 (1932) in aqueous solution a temperature of 25 ° C and a concentration of 1% by weight at pH 7 on the sodium salt of the polymers. The poly mers are in amounts of 0.05 to 2 wt .-%, based on the textile materials to be dyed.

The textile material that after treatment in the dye bath contains the linked dye in the leuco form is in Treated in the usual way to complete the dyeings. For this purpose, the textile material is first according to the in the vat dyeing methods used are oxidized, e.g. B. The material containing the leuco dye lingers air or treatment of this material with an aqueous Liquor, the hydrogen peroxide or another oxidation contains medium. After oxidation, the colored textile Material rinsed and soaped. Completing the dye However, conditions can also be made so that the textile Material that contains the vat dye in the leuco form, first rinsed, then oxidized and then soaped. To the Soaps are usually used with a wetting agent aqueous solution, which may also contain dissolved soda. Man he keeps rubbing and washable dyeings, whereby the waste water is out dyeing plants do not use sulfate or sulfite ions or other compounds derived from reducing agents is contaminated.

Examples example 1

In a pressure-tight sealable laboratory dyeing container, a bleached cotton jersey in an aqueous dye liquor, the 0.5 g / l of the blue vat dye of CI no. 69825 and  Contains 60 ml aqueous sodium hydroxide solution 38 ° Be per liter of liquor, colored at a liquor ratio of 1:20. This brings the material to be dyed is placed in the bath at a temperature of 25 ° C, closes the dyeing device pressure-tight and heats the contents maintains a temperature of 130 ° C within 20 minutes this temperature remains constant for about 30 minutes and cools the In then stop the dyeing machine within 20 minutes a temperature of 60 ° C. The cotton jersey is made taken from the fleet and hung on a line. By the action of air-oxygen becomes the leuco form of the Vat dye oxidized. The blue colored cotton jersey is then rinsed with cold water and then ge soaps by treating it with a liquor that is 1 g / l a commercially available anionic surfactant and 0.5 g / l soda contains. This way you get a rub and wash real blue coloring.

The coloring is despite the high dyeing temperature and despite the absence of substances to protect against over-reduction (Glucose) not over-reduced.

Example 2

A bleached cotton jersey becomes pressure-tight closable laboratory dyeing apparatus in which an aq dyeing liquor was submitted, the 0.5 g / l of the green Kü pen dye of the C.I. 59825 and 60 ml aqueous sodium bicarbonate contains 38 ° Be / l liquor. The dyeing machine is pressurized tightly closed and its contents within 20 minutes heated from a temperature of 25 to 130 ° C. The coloring even at a temperature of 130 ° C within 30 minutes. After that, the content of the dye ap parates within 20 minutes to a temperature of Cooled 60 ° C and removed the cotton jersey. The Oxida tion of the leuco compound of the vat dye, which is due to the Cotton jersey is pulled on, then takes place in one Liquor containing 2 ml of 30% hydrogen peroxide per liter Fleet contains. The oxidation is over after about 15 minutes a temperature of 30 ° C ended. The dyed material turns on finally rinsed cold and soaped with a liquor that 1 g / l of a commercially available anionic surfactant and 0.5 g / l  Contains soda. You get a rubbing and washable green Coloring of the cotton jersey.

Example 3

Example 1 is repeated with the only exception that the dye now is the black vat dye of the C.I. 69525 inserts. You get a black one Cotton jersey that is dyed to rub and wash.

Example 4

Example 2 is repeated with the only exception that the concentration of aqueous sodium hydroxide solution to 300 ml Sodium hydroxide solution, 38 ° Be / l liquor increased. You get one rubbing and washable green coloring.

Comparative Example 1

A bleached cotton jersey is made according to the well-known dye process within 45 min at a temperature of Colored 60 ° C in an aqueous liquor, the 15 ml of aqueous Na Tronlauge 38 ° Be per liter of liquor, 6 g / l sodium dithionite and 0.5 g / l of the green vat dye of C.I. 59825 ent holds. This coloring has about the same depth of color as that Coloring obtained according to Example 4.

Example 5

Example 3 is repeated with the only exception that the aqueous sodium hydroxide concentration to 300 ml Sodium hydroxide solution 38 ° Be increased. You get a rub and wash real black coloring.

Comparative Example 2

A bleached cotton jersey is at a temperature of 60 ° C within 45 min with an aqueous liquor colors the 0.5 g / l of the black vat dye of the C.I.- No. 69525, 15 ml aqueous sodium hydroxide solution 38 ° Be per liter of liquor and contains 6 g / l sodium dithionite. The coloring is as in Example 1 described, completed. A comparison of that Color obtained with that of Example 5 shows that the  Coloring according to Example 5 is more than 20% deeper than those obtained by the known method.

Claims (5)

1. Process for dyeing and printing textile materia lien, which consist of cellulose fibers or Cellulosefa sern mixed with other fibers, in an aqueous liquor at pH values above 12 and temperatures of at least 100 ° C with viable dyes, thereby characterized in that the dyeing is carried out in the absence of the customary reducing agents for the viable dyes at a concentration of alkali metal hydroxide in the liquor of 20 to 500 ml of aqueous alkali metal hydroxide solution at 38 ° Be per liter of liquor and the dyeing is then completed in the customary manner. 2. The method according to claim 1, characterized in that the concentration of the alkali hydroxide 50 to 300 ml aq alkaline solution is 38 ° Be per liter of liquor. 3. The method according to claim 1 or 2, characterized net that sodium hydroxide solution is used as alkali hydroxide and dyeing at temperatures from 120 to 135 ° C leads. 4. The method according to any one of claims 1 to 3, characterized ge indicates that the dyeing or printing additional is carried out in the presence of quinoid compounds, which are water soluble at pH values above 12. 5. The method according to any one of claims 1 to 4, characterized ge indicates that the fleet also contains polymers of monoethylenically unsaturated carboxylic acids as color contains tools.