US3894838A

US3894838A - Process for dyeing unmodified polyolefin fibers with vat dyestuffs, leuco esters of vat dyestuffs or sulfur dyestuffs

Info

Publication number: US3894838A
Application number: US336901A
Authority: US
Inventors: Der Eltz Hans-Ulrich Von; Armand Lehinant; Hans-Peter Maier
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1972-03-07
Filing date: 1973-03-01
Publication date: 1975-07-15
Anticipated expiration: 1992-07-15
Also published as: JPS4899473A; IT981126B; GB1383451A; DE2210877A1

Abstract

Process for dyeing or printing unmodified polyolefin fibers with vat dyestuffs, leuco esters of vat dyestuffs or sulfur dyestuffs, by reacting under high-temperature dyeing conditions on these textile materials aqueous liquids or printing pastes containing the said dyestuffs in unvatted or vatted-up state or as vat acid, in the presence of a dispersion system on the basis of polyglycol ethers and, if required, converting the vatted products applied by reoxidation into their pigment form.

Description

United States Patent von der Eltz et a1.

PROCESS FOR DYEING UNMODIFIED POLYOLEFIN FIBERS WITH VAT DYESTUFFS, LEUCO ESTERS OF VAT DYESTUFFS OR SULFUR DYESTUFFS Inventors: Hans-Ulrich von der Eltz, Frankfurt am Main; Armand Lehinant,

Offenbach, Main; Hans-Peter Maier, Sulzbach, Taunus, all of Germany Hoechst Aktiengesellschaft, Frankfurt am Main, Germany Filed: Mar. 1, 1973 Appl. No.: 336,901

Assignee:

Foreign Application Priority Data Mar. 7, 1972 Germany 2210877 US. Cl. 8/37; 8/30; 8/34;

8/176; 8/180 Int. Cl D06p 1/30 Field of Search 8/30, 34, 37, 180, 176

References Cited UNITED STATES PATENTS 10/1962 Kutncr 8/34 OTHER PUBLICATIONS Cook, Handbook of Polyolefin Fibers, (1967), Merrow Publishing Co., Ltd. pp. 139-141.

Primary ExaminerBenjamin R. Padgett Assistant Examiner-B. Hunt Attorney, Agent, or Firm-Curtis, Morris & Safford [57] I ABSTRACT Process for dyeing or printing unmodified polyolefin fibers with vat dyestuffs, leuco esters of vat dyestuffs or sulfur dyestuffs, by reacting under hightemperature dyeing conditions on these textile materials aqueous liquids or printing pastes containing the said dyestuffs in unvatted or vatted-up state or as vat acid, in the presence of a dispersion system on the basis of polyglycol ethers and, if required, converting the vatted products applied by reoxidation into their pigment form.

8 Claims, No Drawings PROCESS FOR DYEING UNMODIFIED POLYOLEFIN FIBERS WITH VAT DYESTUFFS, LEUCO ESTERS OF VAT DYESTUFFS OR SULFUR DYESTUFFS The present invention relates to a process for the dyeing of unmodified polyolefin fibers with vat dyes, leuco esters of vat dyes or sulfur dyes.

It is known that unmodified polyolefin fibers, for example, polypropylene fibers, are, generally, difficult to dye by direct dyeing methods. Besides the immediate dyeing of the spinning mass in the melt with pigment dyestuffs, the dyeing of piece goods made of such fibers with aqueous suspensions of pigment dyestuffs and curable binding systems is described which form a correspondingly colored film layer fast to washing on the fiber surface when being heated. Disperse dyes used for dyeing polyester fibers and other hydrophobic fibers, however, yield under comparable thermal conditions only very fair dyeings when being fixed, the yield of which is unproportioned with respect to the amount of dyestuff used.

Various methods for the modification of the polyolefin material allow to improve the dye receptivity of the fiber considerably. For example, nitrogen-containing copolymers having a basic effect are introduced into the spinning melt of the ground substance of which the fibers consist and so anchored in the macromolecule. The fibers so modified then have affinity towards the anionic dyestuffs. Polypropylene can also be modified in such a manner that compounds of such metals which can form fast color lakes with metallizable dyestuffs are incorporated into the mass or fiber. Thus, the fiber properties are influenced either by a metal-containing copolymer or by special after-treatment operations of the finished, unmodified fibrous material before dyeing, for example, as described in German Auslegeschriften Nos. 1,297,577, 1,469,600 and 1,619,601. But each of these processes for the modification of polyolefins requires additional operational expenditure which makes the fiber more expensive and sometimes inadvertantly affects the physical properties of the fiber, for example, by reducing its stability and elasticity or by increasing its inflammability.

It was, now found, that unmodified polyolefin fibers preferably polypropylene fibers, can be dyed or printed with vat dyes, leuco esters of vat dyes, or sulfur dyes when allowing aqueous liquors or printing pastes containing the dyestuffs mentioned above in unvatted or vatted-up state or as vat acid to act under hightemperature dyeing conditions on these textile materials in the presence of a dispersion system on the basis of polyglycol ethers and, if required, converting the vatted products applied by reoxidation to adopt their pigment form.

The present invention is based on the observation that vat dyes or sulfur dyes have a technically useful affinity towards the strongly hydrophobic, unmodified polyolefin fibers when they are in their original unvatted form, as leuco dyestuff or as vat acid present in a certain colloidal state of dispersion and are applied under adequate thermal conditions which allow the diffusion into the fiber. Under these conditions the concentration equilibrium of liquid to fiber can be shifted in favor of the fiber. The same applies to leuco esters of vat dyes when they are present as vat acid after acid saponification. When respecting the conditions mentioned above, the dyeing or prints can be effected according to the process claimed using the exhaustion method, the pad-steaming method or a printing method together with steam fixation of the dyes.

The exhaustion method requires temperatures within the range of from to 135C, preferably about C, and a period of action of 40 to 70 minutes, preferably about 60 minutes; the pad-steaming and the print-steaming method require temperatures within the range of from 100 to C, preferably about 130C, and a period of action of from 10 to 40 minutes, preferably about 30 minutes. These temperatures suggested are, while maintaining a technical safety zone, below the range of temperature (from to C) at which the fiber melts.

The form of colloidal dispersion of the dyestuff which is essential for carrying out the process of the invention can be obtained in the following manner:

On the one hand by normal vatting as usually effected by means of sodium dithionite and alkali or sodium sulfide for dyeing vat dyes or sulfur dyes on cellulose fibers, the excess amounts of chemicals in the bath being, however, smaller; on the other hand, the dyestuffs are dispersed in the desired manner which allows a diffusion into and thus an absorption by the fiber, at best by means of an auxiliary mixture. This dispersion system essentially consists of a non-ionic auxiliary on the basis of alkylor alkylaryl-polyglycol ethers or oxethylated fatty acid polyglycol esters, preferably a reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide, which is combined in the exhaustion method with anionic protective colloids having a dispersing effect, preferably those on the basis of ligninsulfonic acid and, optionally, electrolyte in the form of sodium sulfate, and in the pad-steaming or printsteaming method with non-ionic protective colloids having a thickening effect, preferably a completely etherified locust bean flour.

In the thermal process, under high-temperature conditions or when steaming under air-free conditions above 100C, the reduction agents gradually lose their efficiency even with the exclusion of air, so that the leuco dye adopts the form of dispersion-under the action of the dispersing agent which enables the absorption. The same effect is obtained by the formation of the vat acid from solutions of the vatted vat dyestuffs or from leuco esters of the vat dyestuffs by adding acids.

When vatting is effected acid salts, preferably sodium hydrogen sulfite, may be added to the liquids. Sodium hydrogen sulfite avoids the possible separation of elementary sulfur from dithionite, sulfide or polysulfide while forming thiosulfate.

In the case of leuco esters of vat dyestuffs, the vat acid is formed in the dyebath before the dyeing process itself by adding acetic acid (saponification of the ester without oxidation). The protective colloid on the basis of lignin-sulfonic acid which must concomitantly be used has the effect that the vat acid adopts the finely dispersed form desired and has, thus, affinity towards the polyolefin fiber.

A colloidal dispersion of the dyestuffs to be used can also be obtained by dissolving the pigment of the vat dyes or sulfur dyes in a suitable solvent miscible with water, preferably dimethyl formamide, in a ratio of 1 z 3 to 1 10 of dyestuff to solvent, and by introducing this solution in an aqueous bath containing the said protective colloid while stirring. The fine pigment dispersion resulting therefrom grows coarser when heating the liquid to dyeing temperature which leads to the optimal state of dispersion. When working by this method the following reoxidation of the dyestuff is not required but the color yield is somewhat smaller than when dyeing from pure aqueous medium.

Within the process of the invention it cannot be avoided in all cases at which a dyestuff had been applied in its leuco form or as vat acid to effect a reoxidation by oxidizing agents to convert the vatted dyestuff product into its original pigment state, because the hydrophobic nature of the polyolefin fiber does not allow a spontaneous autoxidation with air oxygen. For this purpose, preferably sodium nitrite or nitrous acid or sodium chlorite or chlorous acid are used, the acids having an oxidizing effect being freed from the corresponding salts by means of acetic acid. The temperature to be used during the reoxidation process is within the range of from 100 to 1 C, preferably about 110C, the times of action of the oxidizing agent are within about to 40 minutes. For the purpose pointed out acetic acid has been chosen because it cannot be oxidized under the application conditions in contradistinction to the formic acid and because the pH it yields is not too low as it is, for example, when using mineral acids. Acetic acid, furthermore, exercises a certain, if slight, swelling effect on the unmodified polypropylene fiber which is supposed to be the reason for the fact that the reoxidation temperature can be lower than the dyeing temperature itself. When reoxidizing, an overoxidation does not occur even with dyestuffs otherwise known for their sensibility towards nitrite or oxidation if the reoxidation temperature is controlled correspondingly.

To carry out the dyeings according to the new method suitable vat dyestuffs are those of the type of indigo, thioindigo and the corresponding derivatives thereof, anthraquinone dyestuffs having one or several anthraquinone nuclei, of indanthrone, flavanthrone and anthraquinone carbazole, of acridones, (thio- )oxanthrones, pyranthrones, anthranthrones and anthrinides as well as of dibenzanthrone and dibenzpyrenquinone, etc. The leuco esters of vat dyestuffs used in accordance with the invention are water-soluble products derived from the above-mentioned vat dyestuffs obtained by esterification, preferably with sulfuric acid. Sulfur dyes are meant to be in the process of the present invention easily reducible, water-insoluble polymer substances which are obtained by melting organic compounds, for example, aminophenols, nitrophenols, diaminobenzenes, diaminonaphthalenes, dinitronaphthalenes, etc., with sulfur, alkali metal sulfides or alkali metal polysulfides and which represent heterogeneous high-molecular weight mixtures with thiazine rings, thiazoles, disulfide chains, etc.

According to the process of the invention, the unmodified polyolefin fibers which are otherwise rather difficult to stain, could unexpectedly be dyed with dyestuff assortments already dealt with in commerce under simple conditions with corresponding color intensity depending on the amount of dyestuff used and having very good fastness to light and to wet processing.

It is also surprising that a technically useful dispersion of the leuco dyes, the vat acids or the pigment can be obtained with dispersion agents which have been applied for a long time in industry.

Finally, it wasalso surprising that the reoxidation of the leuco dyes or the vat acids on the fiber occurs quantitatively without running the risk of over-oxidation of the dyestuff caused by the nitrous or chlorous acid (prepared from its sodium salts and acetic acid) under the conditions mentioned.

The following Examples illustrate the invention, the parts and percentages are by weight, unless stated otherwise. The Color-Index-Numbers indicated in the Examples to characterize the dyestuffs have been taken from the 2nd edition 1956 and the supplement volume EXAMPLE 1 Flock material of unmodified polypropylene fibers was dyed in a dyeing apparatus under high-temperature conditions, with a goods-to-liquor ratio of 1 20 at 125C for 60 minutes with an aqueous liquid which contained, calculated on the weight of the dry material,

2 percent of the vat dyestuff Vat Yellow 29 C.l.

No. 68,400, vatted according to the usual prescription with sodium dithionite and sodium hydroxide solution, but avoiding excesses of chemicals in the bath,

4 percent of an anionic protective colloid on the basis of lignin-sulfonic acid,

1 percent of the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide and then rinsed with warm water.

In a second operational step, the leuco vat dyestuff absorbed by the fiber was reoxidized to yield the vat dyestuff by treating the material, first at 30C which temperature was increased within 1 hour to C, with a goods-to-liquor ratio of 1 20, with a fresh bath which contained per liter of water 2 g of sodium nitrite and 2 ml of acetic acid (60 After the dyeing process the fibrous material so treated was rinsed and dried in usual manner.

A yellow dyeing of good fastness properties, especially of good fastness to light and to wet processing, was obtained.

EXAMPLE 2 The dyeing was carried out in an analogous manner as described in Example 1, using, however 2 percent of the vat dyestuff Vat Orange 7 Color Index No. 71,105. A brilliant orange dyeing of very good fastness properties was obtained.

EXAMPLE 3 Dyeing was carried out in an analogous manner as described in Example 1, using, however 2 percent of the vat dyestuff Vat Red 14 Color Index No. 71,110. A brilliant scarlet dyeing of very good fastness properties was obtained.

EXAMPLE 4 Dyeing was carried out in an analogous manner as described in Example 1. The dyestuff used in this case was 2 percent of the vat dyestuff .Vat Red 15 Color Index No. 71,100. v V A wine-red dyeing of very good fastness properties was obtained.

EXAMPLE 5 Dyeing on the textile material was carried out in an analogous manner as described in Example I using as dyestuff, however,

2 percent of the vat dyestuff Vat Blue 4 Color Index No. 69,800. A brilliant solid blue dyeing was obtained.

EXAMPLE 6 When using 2 percent of the vat dyestuff Vat Green 1 Color Index No. 59,825 and dyeing in the same manner as described in Example l, a brilliant bluish green dyeing of very good fastness properties was obtained.

EXAMPLE 7 Dyeing was carried out in an analogous manner as described in Example 1, with the exception that after vatting the dyestuff the liquid was acidified with 2 6 ml/l of an aqueous sodium hydrogensulfite solution of 40Be' to form the finely dispersed vat acid.

A dyeing having the same quality as that described in Example 1 was obtained.

EXAMPLE 8 After an adequate prewashing, piece goods of unmodified polypropylene fibers were padded on the padding mangle with an aqueous liquor of room temperature containing per liter :1 suspension of 20 g of vat dyestuff Vat Red 14 Color Index No.

71,1 in a micro-dispersed form,

10 g of a 2 percent aqueous solution of a completely etherified locust bean flour and 5 g of the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide, with a liquor-pick-up of 70 percent, and dried. Then the material was cross-padded, with a liquor pick-up of 70 percent, with a liquid of room temperature which contained per liter of water 30 g of a reduction agent on the basis of a sulfinic acid derivative,

40 ml of sodium hydroxide solution of 32.5 percent (38B) and 15 g of sodium sulfate (anhydrous) and steamed under high temperature conditions at 130C for 15 minutes with the exclusion of air. The dyeing was then batched up, rinsed in the beam dyeing apparatus and reoxidized as described in Example 1. A brilliant scarlet dyeing of good fastness properties was obtained.

EXAMPLE 9 Flock material of unmodified polypropylene fibers was dyed on a dyeing apparatus under hightemperature conditions, with a goods-to-liquor-ratio of l at 130C for 60 minutes with a liquid which was obtained as follows:

Calculated on the weight of the dry material 2 percent of the vat dyestuff Vat Blue 4 Color Index No. 69,800 were dissolved in 6 percent of dimethyl formamide (optionally by heating to about 40C and this solution was introduced via a calico sieve into an aqueous bath of 40C which contained 5 percent of an anionic protective colloid on the basis of lignin-sulfonic acid and 1 percent of the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide while stirring which yielded a fine dispersion.

After dyeing the material was rinsed with warm water.

A brilliant blue dyeing was obtained. Reoxidation as required in the case of leuco dyes or vat acids is not necessary in this case, but the dyestuff yield is somewhat smaller than that obtained when dyeing from pure aqueous medium.

EXAMPLE l0 Piece-goods of unmodified polypropylene were padded, with a liquor-pick-up of percent at room temperature with a liquid that was prepared in the following manner:

20 g per liter vat dyestuff Vat Green 1 Color Index No. 59,825 were dissolved in 60 ml of dimethyl formamide and the solution was introduced with stirring into an aqueous bath which contained 5 g of the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide and 10 g of a 2 percent aqueous solution of a completely etherified locust bean flour.

The material so treated was steamed for 20 minutes at C in the high-temperature steaming apparatus without intermediate drying and then rinsed with warm and cold water.

In the scope of the dyeing operation described, intermediate drying is possible before steaming. However, reoxidation as described in Examples 1 to 8 is not necessary in this case.

A brilliant green dyeing was obtained.

When proceeding by this method, prints can also be effected on the material.

EXAMPLE 1 1 Loose material of unmodified polypropylene fibers was dyed, with a goods-to-liquor ratio of 1 20, on a high-temperature dyeing apparatus at 130C for 60 minutes with a liquid which was prepared at 40C in the following manner:

Calculated on the weight of the dry material,

2 percent of the leuco ester vat dyestuff Solubilized Vat Green 21 C]. No. 59,051 were dissolved in warm water together with 5 percent of a protective solloid on the basis of ligninsulfonic acid and 1 percent of the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide and to that solution 1 percent of acetic acid (of 60 percent) was added.

After dyeing the material so treated was rinsed with warm water and the vat acid absorbed was reoxidized on the fiber as described in Example 1.

A brilliant fast green dyeing of good yield was obtained.

EXAMPLE l2 Loose material of unmodified polypropylene fibers was dyed, with a goods-to-liquor ratio of l 20, on a dyeing apparatus for 60 minutes with an aqueous liquid of 130C which contained, calculated on the weight of the dry material, the following constituents:

2 percent of the sulfur dyestuff Sulphur Brown 51 C]. No. 53,327,

4 percent of crystallized sodium sulfide,

5 percent of an anionic protective colloid of the type of lignin-sulfonic acid,

1 percent of the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide and 20 percent of sodium sulfate (anhydrous).

After the application of the dyestuff the material so treated was first rinsed with warm water and then it was treated for the reoxidation of the dyestuff at 105C for 20 minutes with an aqueous bath which contained 1 g/l of sodium nitrite and 2 m/l of acetic acid (60 A fast brown dyeing was obtained.

We claim:

1. A process for dyeing or printing unmodified polypropylene fibers with vat dyestuffs, leuco esters of vat dyestuffs or sulfur dyestuffs, which comprises: reacting under high-temperature dyeing conditions above 100C on these textile materials aqueous liquids or printing pastes containing the said dyestuffs, in unvatted or vatted-up state or as vat acid, in the presence of a dispersion system based upon polyglycol ethers or esters and, if required, converting the vatted products applied by reoxidation into their pigment form.

2. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are padded or printed onto the fibers in vatted-up state and in the presence of a non-ionic protective colloid having a thickening effect of the type of a completely etherified locust bean flour; and these paddings or prints are then steamed in a pressure steamer at 100C to 135C for 10 to 40 minutes and fi nally oxidized.

3. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are used in vatted-up state and in the presence of an anionic protective colloid having a dispersing effect based upon lignin-sulfonic acid; and the dyestuffs are applied to the fibers in the finely dispersed form so obtained according to the exhaustion method, for 40 to 70 minutes at a temperature of 120 to 135C, and finally oxidized.

4. A process as claimed in claim 1, wherein: leuco esters of vat dyestuffs are used in the presence of an anionic protective colloid having a dispersing effect based upon lignin-sulfonic acid, by treating them with acetic acid while saponifying the esters without oxidation to yield the vat acid; and the dyestuffs are then applied to the fibers in the finely dispersed form so obtained according to the exhaustion method, for 40 to minutes at a temperature of from 120 to 135C, and finally oxidized.

5. A process as claimed in claim 1, wherein: leuco esters of vat dyestuffs are used in the presence of a nonionic protective colloid having a thickening effect of the type of a completely etherified locust bean flour, by treating them with acetic acid while saponifying the esters without oxidation to yield the vat acid; the dyestuffs are then padded or printed onto the fibers in the finely dispersed state so obtained; and these paddings or prints are then steamed in a pressure steamer at to 135C for 10 to 40 minutes, and finally oxidized.

6. A process as claimed in claim 1, wherein the leuco dyestuff or the vat acid applied is reoxidized into its pigment form by treating the dyeings or prints with sodium nitrite or sodium chlorite in the presence of acetic acid for 20 to 40 minutes at 100 to C.

7. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are dissolved, without vatting, in dimethyl formamide in a ratio of 1 3 to 1 :10; the solution so obtained is introduced, while stirring, into an aqueous liquid together with an anionic protective colloid having a dispersing effect based upon ligninsulfonic acid; and the dyestuffs are applied to the fibers in the finely dispersed form so obtained according to the exhaustion method for 40 to 70 minutes at a temperature of from to C.

8. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are dissolved, without vatting, in dimethyl formamide in a ratio of l 3 to l 10; the solution so obtained is introduced, while stirring, into an aqueous liquid or printing paste together with a nonionic auxiliary based upon the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide in combination with non-ionic protective colloids having a thickening effect of the type of a completely etherified locust bean flour; the dyestuffs are padded or printed onto the fibers in the finely dispersed form so obtained; and these paddings or prints are then steamed in a pressure steamer at 100 135C for 10 to 40 minutes.

Claims

1. A PROCESS FOR DYEING OR PRINTING UNMODIFIED POLYPROPYLENE FIBERS WITH VAT DYESTUFFS, LEUCO ESTERS OF VAT DYESTUFFS OR SULFUR DYESTUFFS, WHICH COMPRISES: REACTING UNDER HIGH-TEMPERATURE DYEING CONDITIONS ABOVE 100*C ON THESE TEXTILE MATERIALS AQUEOUS LIQUIDS OR PRINTING PASTES CONTAINING THE SAID DYESTUFFS, IN UNVATTED OR VATTED-UP STATE OR AS VAT ACID, IN THE PRESENCE OF A DISPERSION SYSTEM BASED UPON POLYGLYCOL ETHERS OR ESTERS AND, IF REQUIRED, CONVERTING THE VATTED PRODUCTS APPLIED BY REOXIDATION INTO THEIR PIGMENT FORM.

2. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are padded or printed onto the fibers in vatted-up state and in the presence of a non-ionic protective colloid having a thickening effect of the type of a completely etherified locust bean flour; and these paddings or prints are then steamed in a pressure steamer at 100*C to 135*C for 10 to 40 minutes and finally oxidized.

3. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are used in vatted-up state and in the presence of an anionic protective colloid having a dispersing effect based upon lignin-sulfonic acid; and the dyestuffs are applied to the fibers in the finely dispersed form so obtained according to the exhaustion method, for 40 to 70 minutes at a temperature of 120* to 135*C, and finally oxidized.

4. A process as claimed in claim 1, wherein: leuco esters of vat dyestuffs are used in the presence of an anionic protective colloid having a dispersing effect based upon lignin-sulfonic acid, by treating them with acetic acid while saponifying the esters without oxidation to yield the vat acid; and the dyestuffs are then applied to the fibers in the finely dispersed form so obtained according to the exhaustion method, for 40 to 70 minutes at a temperature of from 120* to 135*C, and finally oxidized.

5. A process as claimed in claim 1, wherein: leuco esters of vat dyestuffs are used in the presence of a non-ionic protective colloid having a thickening effect of the type of a completely etherified locust bean flour, by treating them with acetic acid while saponifying the esters without oxidation to yield the vat acid; the dyestuffs are then padded or printed onto the fibers in the finely dispersed state so obtained; and these paddings or prints are then sTeamed in a pressure steamer at 100* to 135*C for 10 to 40 minutes, and finally oxidized.

6. A process as claimed in claim 1, wherein the leuco dyestuff or the vat acid applied is reoxidized into its pigment form by treating the dyeings or prints with sodium nitrite or sodium chlorite in the presence of acetic acid for 20 to 40 minutes at 100* to 115*C.

7. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are dissolved, without vatting, in dimethyl formamide in a ratio of 1 : 3 to 1 :10; the solution so obtained is introduced, while stirring, into an aqueous liquid together with an anionic protective colloid having a dispersing effect based upon lignin-sulfonic acid; and the dyestuffs are applied to the fibers in the finely dispersed form so obtained according to the exhaustion method for 40 to 70 minutes at a temperature of from 120* to 135*C.

8. A process as claimed in claim 1, wherein: vat or sulfur dyestuffs are dissolved, without vatting, in dimethyl formamide in a ratio of 1 : 3 to 1 : 10; the solution so obtained is introduced, while stirring, into an aqueous liquid or printing paste together with a non-ionic auxiliary based upon the reaction product of 1 mol of isotridecyl alcohol with 8 mols of ethylene oxide in combination with non-ionic protective colloids having a thickening effect of the type of a completely etherified locust bean flour; the dyestuffs are padded or printed onto the fibers in the finely dispersed form so obtained; and these paddings or prints are then steamed in a pressure steamer at 100* - 135*C for 10 to 40 minutes.