DE3833194A1 - METHOD FOR COLORING TEXTILE MATERIALS FROM CELLULOSE FIBERS - Google Patents

Abstract

Process for dyeing textile materials from cellulose fibres in an alkaline aqueous medium with vat dyes in the presence of reducing agent mixtures of a) sodium dithionite and/or thiourea dioxide and b) alpha -hydroxycarbonyl compounds in a weight ratio of 1:1 to 1:15 at a pH of at least 13 and at temperatures of above 75 DEG C and finishing the dyeings in a conventional manner. The dyeings obtained are very level.

Description

When dyeing textile materials made of cellulose fibers or contain cellulose fibers in a mixture with synthetic fibers, with vat dyes are worked in an alkaline aqueous medium in the presence of Reducing agents and, if appropriate, other customary auxiliaries Temperatures of, for example, 45 to 60 ° C and then the Dyes finished by rinsing, oxidizing and soaps. The most famous reducing agents used in vat dyeing of Textile materials containing cellulose fibers are used Sodium dithionite, thiourea dioxide (formamidine sulfinic acid) and hydroxy acetone. For example, it is known from DE-OS 20 11 387, in which Vat dyeing of textiles containing cellulose fibers thiourea use dioxide as a reducing agent. As from this publication is also known, the reduction of vat dyes can also in Presence of glucose can be made to prevent sensitive Liche dyes are "reduced". According to the information in the Examples is glucose, based on the amount of thiourea dioxide in the Deficit used. The levelness of the vat colorations that can be achieved with it is still in need of improvement.

From DE-PS 21 64 463 is a method for dyeing and printing Textile materials with vat dyes known in which the reduction the vat dyes in an aqueous medium at a pH of at least 12 with hydroxyacetone in the presence of quinoid compounds which are water-soluble under the dyeing conditions. The disadvantage here is that quinoid compounds must be used and the number of vat dyes suitable for this process is limited.

The present invention has for its object a method for Dyeing textile materials consisting of cellulose fibers or Cellulose fibers contained in a mixture with synthetic fibers, in alkaline aqueous medium with vat dyes in the presence of reducing agents to provide blends and finishing the colors, at which gives dyeings with better levelness than with known dyeings method.

The object is achieved in that as a reduction medium mixtures combinations

• a) sodium dithionite and / or thiourea dioxide and
• b) α- hydroxycarbonyl compounds

in a weight ratio of 1: 1 to 1:15 and the coloring at pH values of at least 13 and at temperatures above 75 ° C.

The textile materials consist of or contain cellulose fibers Cellulose fibers mixed with other fibers. You can in any Processing state, e.g. as a flake, card sliver, yarn, skein, Woven or knitted fabric. The cellulose fibers can either be natural or regenerated cellulose, such as cellulose or polynosic Trade fibers. The method according to the invention is particularly suitable for Dyeing mercerized cotton, raw cotton and dyeing Raw yarns that are available as a package or as a skein. Synthetic fibers, which are present in the textile materials in a mixture with cellulose fibers, are, for example, polyester fibers or synthetic polyamide fibers. The Fibers made from natural or regenerated cellulose are used in vats dyes colored. The vat dyes are mainly around anthrachinoid and indigoid dyes. Vat dyes have been around long available in stores and documented in the Color Index, cf. Color Index, 3rd edition, 1971, volume 3, pages 3719-3844 and volume 4, C.I. No. 58,000-74,000, Society Dyers and Colorists, England.

Process for dyeing cellulose fibers with vat dyes in the presence of reducing agent mixtures have already become the prior art above resolved. Based on the textile material, this requires 0.01 up to 10% by weight vat dye or a mixture of several vat dyes. The dyeing of the textile materials can take a long time, for example aqueous liquor at a liquor ratio of 1: 5 to 1:40, preferably 1: 8 to 1:20, or also in the continuous process, e.g. Log method. Here one works with fleet ratios from 1: 0.5 to 1: 3. According to the invention, the vat dyes are reduced in aqueous Medium at pH values of at least 13 and with reducing agent mixtures out

• a) sodium dithionite and / or thiourea dioxide (formamidine sulfinic acid) and
• b) α- hydroxycarbonyl compounds

in a weight ratio of 1: 1 to 1:15 at temperatures above 75 ° C.

Sodium is used as component a) of the reducing agent mixtures dithionite, thiourea dioxide or mixtures of sodium dithionite and thiourea dioxide in any ratio. Is preferred as Component a) sodium dithionite used.  

As component b) of the reducing agent mixtures, α- hydroxycarbonyl compounds come into consideration. Suitable α- hydroxycarbonyl compounds are, for example, monohydroxyacetone (hereinafter referred to as hydroxyacetone), dihydroxyacetone, glycolaldehyde, dihydroxybutanone, 2,3-dihydroxyacrylaldehyde, ascorbic acid and cyclopentendiol-2,3-one-1, which is referred to as triose reductone. Compounds of this type are referred to as reductones and reductonates. Further examples of compounds of this type are triose reductone and reducing acid, which are obtained, for example, by acidic or alkaline degradation of glucose, saccharides or polysaccharides, such as starch, molasses and pectin. From this group of reducing agents, preference is given to hydroxyacetone. It is of course also possible to use mixtures of several α- hydroxycarbonyl compounds as component b) of the combinations to be used according to the invention, for example mixtures of hydroxyacetone and glucose.

A combination of is preferably used as the reducing agent mixture

• a) sodium dithionite and
• b) hydroxyacetone

in a weight ratio of 1: 2 to 1:10. The coloring is carried out at pH values of performed at least 13. In contrast to those, you need this Coloring process in which sodium dithionite is used as the sole reduction medium uses a higher amount of alkali. The pH of the aqueous Coloring medium is preferably added to the liquor by adding sodium hydroxide solution set. Other bases, such as Potash lye, can be used will. A pH of at least 13 is obtained by adding at least 20 ml / l liquor in aqueous sodium hydroxide solution 38 ° B´, preferably of more than 25 ml / l sodium hydroxide solution reached 38 ° B´. The textile materials become Coloring is introduced into the aqueous alkaline liquor containing the vat dye and the reducing agent mixtures to be used according to the invention and optionally contains other conventional dyeing aids. The textile Material is in the fleet at temperatures above 75 to 120, preferably 80 to 105 ° C colored. Provided dyeing temperatures above 100 ° C are to be used, the coloring in the usual Printing equipment carried out. Under these conditions, the solubilized vat dyes on the textile material. The Dyeing time is about 30 to 120 minutes. The reducing agent mixtures are in amounts of 1 to 20, preferably 2 to 10 g / l in the liquors applied.  

The textile material that after the treatment in the dye bath the vat color contains substance in the leuco form, is then treated in the usual way, to complete the coloring. To do this, the textile material is first oxidized by methods used in vat dyeing. After this The textile material is oxidized, rinsed and soaped. The finishing the dyeings can also be carried out in such a way that the textile material, which contains the vat dye in the leuco form, first rinsed, then is oxidized and then soaped.

The method according to the invention can of course also be present common leveling agent for vat dyeing, e.g. in the presence of Polyvinyl pyrrolidone or water-soluble polyamides are made, which are known for example from DE-PS 11 25 881. When dyeing textile materials made of mercerized raw cotton or raw cotton one additionally uses homopolymers as dyeing aids Acrylic acid or methacrylic acid, copolymers of acrylic acid or meth acrylic acid with other monomers, e.g. Methacrylamide, acrylamide, acrylic nitrile, methacrylonitrile, acrylic acid esters, methacrylic acid esters as well Maleic acid, as well as the alkali or ammonium salts of the carboxyl groups containing homo- or copolymers. Copoly are also suitable merisate from maleic acid and styrene, maleic acid and vinyl esters or Maleic acid and vinyl ethers. The polymers in question have Viscosities (measured with the Höppler falling ball viscometer at 20 ° C according to DIN 53 015) from 1 to 300 mPas in 7.5% by weight aqueous Solution adjusted to pH 9 with caustic soda. The Use of such polymers in vat dyeing in amounts from 0.05 to 2% by weight, based on the material to be dyed, is known from DE-PS 24 44 823.

The advantages of the method according to the invention lie in an improved levelness of the textile materials containing dyed cellulose fiber. This applies in particular to those textile materials that are difficult to dye regardless, such as mercerized cotton, in particular mercerized cotton yarn in rope form or cotton yarn on particularly large packages (for example packages with more than 1200 g of yarn). In addition, compared to the use of known reducing agent mixtures, level dyeings in vat dyes or dye combinations of vat dyes are obtained, in which otherwise problems of levelness occur in the colored materials. Another advantage of the method according to the invention is that the wastewater pollution of the textile plant can be classified as lower than if sodium dithionite or thiourea dioxide are used alone.

The parts given in the examples are parts by weight, the details in Percent is percent by weight.

example 1

A strand of mercerized raw cotton is sold on a trade usual strand yarn dyeing machine first pre-wetted by using the goods 3 g / l of a phosphoric acid diethylhexyl ester as wetting agent for 15 minutes Room temperature with constant pumping around the dye bath in the dyeing machine is treated. The strand yarn of mercerized raw cotton so wetted is then at a liquor ratio of 1:20 at 100 ° C with a Colored bath of the following composition:

1 part of the blue vat dye CI 69825
40 parts of warm sodium hydroxide solution 38 ° B´
2 parts of sodium dithionite
4 parts of hydroxyacetone
1 part sodium polyacrylate (molecular weight 60,000)
952 parts of water

The bath is heated to 100 ° C within 30 minutes. You dye 45 minutes at 100 ° C, then cools to 60 ° C and restores the color finished as usual. An even blue-colored strand yarn is obtained good color and very good fastness properties. The good equality of the Coloring within the strand and between different strands clearly recognizable if you knit pieces from the yarn of a strand and made from the yarn of different strands.

Example 2

Raw cotton yarn is made in a commercially available package winder with an aqueous bath containing 3 g / l phosphoric acid diethylhexyl Contains wetting agent for 15 minutes at room temperature with continuous pumping treated of the aqueous medium. The raw cotton yarn so wetted becomes then with a bath ratio of 1:15 with a bath following Colored composition:

0.8 parts of the olive vat dye CI 69525
30 parts of aqueous sodium hydroxide solution 38 ° B '
1 part sodium dithionite
4 parts of hydroxyacetone
1 part sodium polyacrylate with a viscosity of 35 mPas (30% aqueous solution at 20 ° C)
963.2 parts water

After the bath described above has been heated to 60 ° C., the liquor is pumped around at 60 ° C. for 10 minutes. The liquor is then heated to 90 ° C. within 15 minutes with continuous pumping and the textile is dyed at 90 ° C. for a good 40 minutes. The bath is then cooled to 60 ° C and the coloring is finished as usual, namely rinsing with water, oxidizing with 1 ml / l of hydrogen peroxide 40% and boiling soaps with a liquor containing 0.5 g / l of an adduct of 25 moles of ethylene contains oxide on 1 mole of a C ₁₂ / C ₁₈ fatty alcohol.

A uniformly olive-gray textile material with very good throughput was obtained staining and very good fastness properties. The good level of cross-wound dyeing became clearly recognizable by the fact that knitwear is made at which the inner yarn layers and the outer yarn layers of a cheese be knitted on. There are no differences in color and Color depth determined between the inner and outer layers of yarn.

Example 3

Ready-to-dye cotton woven goods were dyed on a conventional laboratory dyeing machine in closed bombs, which were moved throughout the dyeing process, with an aqueous liquor which contained the following constituents:
0.3% of the orange vat dye CI 69025 and
0.5% of the blue vat dye CI 59800 (each based on the weight of the dry cotton weave),
30 ml / l aqueous sodium hydroxide solution (38 ° B´)
0.3 g / l sodium dithionite and
3 g / l hydroxyacetone.

The liquor ratio was 1: 20. The liquor was heated to 60 ° C. At this temperature was initially only taken into account with half of the material to be dyed and adds the second half of the dye 5 minutes later. Both Tissue pieces were then closed together with constant movement of the bombs End stained by letting the liquor at 80 ° C within 10 minutes heated and then left at 80 ° C for 30 minutes. After that the coloring in Completed in the usual way by rinsing the fabric with water with 1 ml / l hydrogen peroxide oxidized and with a commercially available after dish soap at 95 to 100 ° C.

The two dyes 3 and 4 used for dyeing have a very different migratory ability and pull up differently quickly.  

It was therefore not to be expected that the piece of tissue added later in Color depth and nuance of the fabric in the dye bath from the start piece corresponds. The example shows, however, that both pieces of tissue are almost were colored the same and thus good equality was achieved.

Example 4

Example 3 was repeated with the exception that the liquor now contained the following amounts instead of the amounts of sodium hydroxide solution, sodium dithionite and hydroxyacetone given in Example 3:
35 ml / l aqueous sodium hydroxide solution 38 ° B´
0.5 g / l sodium dithionite and
3.5 g / l hydroxyacetone.

Two dyed pieces of fabric were obtained, which differ in color depth and shade hardly differentiated. Even under these unfavorable staining conditions achieved good equality.

Comparative Example 1

The dyeing instructions given in Example 3 with dyes 3 and 4 was repeated with the exceptions that the aqueous dye liquor - as in the usual way of working according to the IN method - 12 ml / l aqueous sodium hydroxide solution 38 ° B´ and 3 g / l sodium dithionite as sole reduction contained medium. With this way of working you get clearly unequal dyed pieces of fabric. The piece of tissue added later was clear colored lighter and less blue.

Comparative Example 2

The procedure given in example 3 was again with the exceptions fetches that the dye liquor 2.5 g / l sodium dithionite and 0.5 g / l hydroxy contained acetone. The amount of sodium hydroxide solution remained unchanged. Man received two clearly unevenly colored fabrics with this procedure pieces. The piece of fabric added later was significantly lighter and less colored blue.  

Comparative Example 3

The procedure given in example 3 was again with the exceptions gets that 20 ml / l aqueous sodium hydroxide solution 38 ° B´, 2.5 g / l Sodium dithionite and 2 g / l hydroxyacetone used. You also got in in this case two clearly unevenly colored pieces of fabric, one of which is the Tissue pieces added later stained much lighter and less blue was.

Claims (4)

1. Process for dyeing textile materials which consist of cellulose fibers or contain cellulose fibers in a mixture with synthetic fibers, in an alkaline aqueous medium with vat dyes in the presence of reducing agent mixtures and finishing the dyeings, characterized in that mixtures of combinations are used as reducing agents

• a) sodium dithionite and / or thiourea dioxide and
• b) α- hydroxycarbonyl compounds

in a weight ratio of 1: 1 to 1:15 and the coloring at pH values of at least 13 and at temperatures above 75 ° C carries out. 2. The method according to claim 1, characterized in that combinations of

• a) sodium dithionite and
• b) hydroxyacetone

in a weight ratio of 1: 2 to 1:10.