WO2002097187A1

WO2002097187A1 - Method for reducing pilling

Info

Publication number: WO2002097187A1
Application number: PCT/EP2002/004184
Authority: WO
Inventors: Cornelia Kinscherf; Heike Bartl
Original assignee: Carl Freudenberg Kg
Priority date: 2001-05-25
Filing date: 2002-04-16
Publication date: 2002-12-05

Abstract

The invention relates to a method for preventing, or at least reducing pilling in nonwoven materials consisting of non-split and/or partially split microfibres and/or microfilaments of synthetic polymers, containing at least one polyester component, at least one polyamide component and optionally at least one polyurethane component. According to the method, the nonwoven material is treated with an aqueous alkali.

Description

Pilling Reduction Process

The present invention relates to a method for avoiding or at least reducing the pilling of nonwoven fabrics from unsplit and / or at least partially split microfibers and / or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and optionally at least one polyurethane component, according to which the nonwoven fabric with aqueous Alkali is treated.

Textile materials made of synthetic polymers, such as polyamide, polyester or polyurethane, which have been produced by the classic method of weaving warp and weft or by stitch formation, have been widely used in a wide variety of applications, for example because of their diverse excellent properties Clothing or the automotive industry.

Nonwovens which are produced by strengthening microfibers and / or microfilaments, in particular at least partially split microfibers and / or microfilaments, can be produced very inexpensively, but are only very suitable for a number of applications. One of the reasons for this is that such nonwovens tend to form nodules, that is to say pilling. This results in an unsightly appearance of the nonwoven fabric, which renders the use of such nonwoven fabrics unusable for a number of applications or severely limits their possible uses.

It was therefore an object of the present invention to find a process by which no or at least reduced pilling in a nonwoven fabric composed of unsplit and / or at least partially split microfibers and / or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and optionally at least one

Polyurethane component is reached.

This object is achieved by the method according to the invention for avoiding or at least reducing the pilling of nonwoven fabrics from unsplit and / or at least partially split microfibers and / or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and optionally at least one polyurethane component, according to which the nonwoven fabric is treated with aqueous alkali.

In a preferred embodiment of the process according to the invention, the nonwoven fabric to be treated with aqueous alkali is used as untreated raw material.

In a further preferred embodiment, the nonwoven fabric used according to the invention consists of at least one polyester component and at least one polyamide amide component, these two plastic components preferably in a ratio of 5 to 95% by weight of the Polyester component and 95 to 5% by weight of the polyamide component, preferably 15 to 85% by weight of the polyester component and 85 to 15% by weight

% of the polyamide component, particularly preferably from 30 to 70% by weight of the

Polyester component and 70 to 30 wt .-% of the polyamide component are present.

The polyamide component is preferably selected from the group consisting of polyamide 6, polyamide 66 and polyamide 11.

The polyester component is preferably selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate,

Polybutylene terephthalate, polylactic acid, their mixtures and copolyesters. Such copolyesters can be prepared either by partial exchange of the acid component and / or by partial exchange of the diol component, as described, for example, in Büttner "Basically Modified Polyester Fibers" in "Die Angewandte Makromolekulare Chemie" 40/41, 1974, pages 57-70 (no. 593) or GG Kulkami, Colorage, August 21, 1986, pages 30-33. The corresponding literature descriptions are hereby introduced as a reference and are considered part of the disclosure.

The nonwoven fabric can also preferably have a polyester based on lactic acid as the polyester component, as described in EP 1 091 028. The corresponding description is hereby introduced as a reference and is considered part of the disclosure.

In a further preferred embodiment of the method according to the invention, the titer of the microfibers and / or microfilaments of the nonwoven fabric is <1 dtex. The nonwoven fabric used according to the invention is preferably a staple fiber nonwoven fabric or spunbonded nonwoven fabric, particularly preferably a spunbonded nonwoven fabric. Such nonwovens can in each case be produced by customary methods known to the person skilled in the art. The production of corresponding spunbonded nonwovens is described, for example, in EP 0 814 188. The corresponding description is hereby introduced as a reference and is considered part of the disclosure.

The nonwoven fabric used according to the invention preferably has a weight per unit area of 15 to 350 g / m ² , particularly preferably 50 to 300 g / m ² and very particularly preferably 80 to 200 g / m ² .

The aqueous alkali used in the process according to the invention is preferably sodium hydroxide solution, potassium hydroxide solution or a mixture thereof, particularly preferably sodium hydroxide solution.

The process according to the invention can be carried out continuously, semi-continuously or batchwise.

The concentration of alkali can vary in the treatment of the nonwoven fabric by the process according to the invention, for example depending on the ratio of the different plastic components, the degree of splitting of the fibers or the type of process. The person skilled in the art can determine the optimum alkali concentration for the respective nonwoven fabric and the respective procedure by means of simple preliminary tests.

The concentration of the alkali in the aqueous treatment solution is preferably 0.01 to 2 mol / l, preferably 0.1 to 1.9 mol / l, particularly preferably 0.15 to 1.75 mol / l. The treatment time of the nonwoven varies and depends, among other things, on the pH of the treatment solution and / or the treatment temperature.

Preferably, the method according to the invention for treating the nonwoven fabric can be carried out at elevated temperature, e.g. shorten the treatment time. The treatment of the nonwoven fabric is preferably carried out at a temperature of from 15 to 240 ° C., particularly preferably from 40 to 210 ° C. and very particularly preferably from 60 to 120 ° C.

The treatment time with aqueous alkali is preferably 10 seconds to 600 minutes, particularly preferably from 15 seconds to 2 hours.

If the process according to the invention is carried out continuously, the treatment of the nonwoven fabric in addition to the application of the aqueous alkali, for example by padding, preferably also intermediate drying, fixation with dry heat or fixation with saturated steam or a combination of at least two of these further process steps within the above indicated treatment time and the above range for the treatment temperature.

Furthermore, after treatment with aqueous alkali, the nonwoven fabric is preferably preferably rinsed and neutralized with an acidic, aqueous solution and optionally dried under the conditions mentioned above.

Usually, the nonwovens made of unsplit and / or at least partially split microfibers and / or microfilaments of synthetic polymers are also dyed or printed to design their appearance. The treatment of the nonwoven fabric with aqueous alkali according to the invention is advantageously carried out in one process step during the dyeing or printing of the nonwoven fabric by customary dyeing or printing processes known to the person skilled in the art. By carrying out these process steps at the same time, the amount of waste water and the treatment time of such nonwovens can be reduced to reduce or avoid pilling and for dyeing or printing, so that they can be finished more cost-effectively.

The treatment with aqueous alkali can preferably be carried out together with the dyeing of the nonwoven fabric by the exhaust process, according to which the dye is drawn onto the nonwoven fabric from the alkalized dye bath. The dyeing according to the exhaust process can preferably be carried out on a nozzle dyeing machine, a jigger or on a reel curve.

The nonwoven fabric can also preferably be treated with aqueous alkali together with the dyeing of the nonwoven fabric by a continuous process, for example the padding process, the padding steaming process or the padding heat setting process.

The treatment of the nonwoven fabric with aqueous alkali can also be carried out during the printing of the nonwoven fabric using customary processes known to the person skilled in the art, preferably according to a direct printing process, particularly preferably according to the flat film, rotary film, Rouleaux or ink jet printing process, or before printing the transfer printing process.

The treatment of the nonwoven fabric with aqueous alkali and the dyeing or printing of the nonwoven fabric can be followed by customary process steps known to the person skilled in the art. The procedure in which the treatment with aqueous alkali is carried out during the dyeing with at least one vat and / or sulfur dye according to one of the dyeing or printing processes specified above is particularly suitable. For this reason, a reducing agent known to the person skilled in the art, such as, for example, sodium hydrosulfite, is usually added to the alkaline treatment solution in order to dissolve the respective dye. After the dye has been applied to the microfibers and / or microfilaments of the nonwoven, it is converted back into the insoluble dye by oxidation using a conventional auxiliary known to the person skilled in the art, for example by hydrogen peroxide. Of course, the corresponding dyes can also be added to the alkaline treatment solution in their dissolved form, ie in the form of corresponding leuco vat dyes or water-soluble sulfur dyes.

As vat dye, a dye selected from the group of the anthraquinones, indigoids or leucocubes ester dyes can be used, as described, for example, in "Rath Textbook of Textile Chemistry", Springer-Verlag, Berlin, Heidelberg, New York, 3rd edition 1972, pages 462 to 485 are described. The corresponding literature description is hereby introduced as a reference and is considered part of the disclosure.

The treatment of the nonwoven fabric with aqueous alkali can also take place during the dyeing or during the printing of the nonwoven fabric with at least one disperse dye. Suitable disperse dyes which are stable with respect to aqueous alkali are known to the person skilled in the art.

The nonwovens used according to the invention can sometimes have poor color fastnesses, such as after dyeing or printing Show fastness to washing, light and perspiration, an uneven color drop within one batch, poor reproducibility of the color between different batches and dull, matt colors.

Surprisingly, these errors can be avoided by the treatment according to the invention with aqueous alkali during the dyeing or printing. The nonwovens treated and dyed or printed in this way show, in addition to sufficient color fastness and depth of color, improved uniformity of color within one section of the nonwoven fabric and improved reproducibility of the color between different sections of the nonwoven fabric.

In particular, the inexpensive staple fiber or spunbonded nonwovens can be equipped with the process according to the invention with a minimal tendency to pilling and can be dyed and finished with an elegant sheen.

With treatment times of more than 10 seconds and at an elevated treatment temperature, it is possible not only to reduce the tendency of the nonwoven to pilling, but also surprisingly to achieve a silky sheen and a pleasantly smooth feel.

Conventional textile materials have to be treated with considerable effort for such a handle improvement, which is not necessary with the nonwovens treated according to the invention.

As already mentioned, the nonwoven fabric treated by the method according to the invention is characterized by no or at least a reduced tendency to pilling in addition to good tear strength.

The pilling tendency of the nonwovens treated according to the method according to the invention is determined according to EN ISO 12945 according to method 1 and / or method 2 or determined according to DIN 53 867. The corresponding

Descriptions are hereby introduced as a reference and are considered part of the

Epiphany.

The wash fastness of the nonwovens treated and dyed according to the invention at 95 ° C. were determined according to EN ISO 105 C06-E2S, the sweat fastness (acidic and alkaline) according to EN ISO 105 E04 and the light fastness according to EN ISO 105 B02. The corresponding descriptions are hereby introduced as a reference and are therefore considered part of the disclosure.

In the following the invention will be explained with the aid of examples. These explanations are only examples and do not limit the general idea of the invention.

Example 1 :

A spunbonded nonwoven fabric with a basis weight of 100 g / m ² consisting of partially split microfilaments with a titer of approx. 0.15 dtex from 30% by weight of polyamide 66 and 70% by weight of polyethylene terephthalate was treated with an aqueous treatment solution containing 100 g / l of a 50 wt .-% NaOH padded. The liquor absorption was 100% by weight, based on the weight per unit area of the nonwoven used. The treated nonwoven fabric was then dried at 120 ° C. for 90 seconds and then fixed with hot air at 220 ° C. for 90 seconds. The nonwoven fabric treated in this way was then neutralized with 6 ml / l of 60% by weight acetic acid and rinsed with cold water.

The spunbonded nonwoven treated according to the invention exhibits excellent pilling behavior, determined in accordance with DIN 53 867. Example 2:

A spunbonded nonwoven fabric with a basis weight of 100 g / m ² consisting of partially split microfilaments with a titer of approx. 0.15 dtex from 30% by weight of polyamide 66 and 70% by weight of polyethylene terephthalate was mixed with an aqueous treatment solution containing 21 ml / l of a 50 wt .-% NaOH treated for 80 minutes at 80 ° C. The nonwoven fabric was then neutralized with acetic acid solution and rinsed with cold water.

The spunbonded nonwoven treated according to the invention exhibits excellent pilling behavior, determined in accordance with DIN 53 867.

Example 3:

A spunbonded nonwoven fabric with a basis weight of 100 g / m ² consisting of partially split microfilaments with a titer of approx. 0.15 dtex from 30% by weight of polyamide 66 and 70% by weight of polyethylene terephthalate was mixed with an aqueous liquor of 60 g / l of vat dye Cl Vat Black 9 and dried at 120 ° C for 90 seconds. The nonwoven fabric was then padded with 80 g / l of 50% by weight NaOH and 80 g / l sodium hydrosulfite. The liquor absorption when the dye or NaOH / sodium hydrosulfite was applied was 100% by weight, based on the weight per unit area of the nonwoven used. The nonwoven fabric was then dried for 90 seconds at 220 ° C. and then subjected to saturated steam treatment at 103 ° C. for 1 minute. Then an oxidation with 10 ml / l of 50% by weight hydrogen peroxide solution was carried out. The material thus obtained was then neutralized with 3 ml / l of 60% strength by weight acetic acid and then soaped at 70 ° C. for 20 minutes and rinsed with cold water. The wash, sweat and light fastness properties of the spunbonded fabric treated and dyed according to the invention are shown in Table 1 below. The spunbonded nonwoven treated according to the invention is characterized by a reduced pilling behavior - determined according to DIN 53 867. The corresponding values are given in addition to the values for the untreated raw material in Tables 2 and 3 below.

Example 4:

A spunbonded nonwoven with a basis weight of 100 g / m ² consisting of partially split microfilaments with a titer of approx. 0.15 dtex made of 30% by weight of polyamide 66 and 70% by weight of polyethylene terephthalate was used in a jet dyeing machine (Soft-TRD , Thies, Coesfeld, Germany) in the presence of 1 g / l of a defoamer based on a preparation of fatty acid ester, 1 g / l of a dispersant based on a naphthalene sulfonate, 2 g / l of a dispersant based on acrylate copolymers, 21 ml / l a 50% by weight NaOH, 8 g / l sodium hydrosulfite and 5% by weight (based on the weight of the raw material) of the vat dye Cl Vat Black 9 at a liquor ratio of 1:10. The coloring took place within 30 minutes at 80 ° C. It was then rinsed with water, oxidized with 5 ml / l of a 30% strength by weight hydrogen peroxide solution at 60 ° C. for 15 minutes and soaped at 70 ° C. for 20 minutes and rinsed with cold water.

The wash, sweat and light fastness properties of the spunbonded fabric treated and dyed according to the invention are shown in Table 1 below. The spunbonded nonwoven treated according to the invention is characterized by a reduced pilling behavior - determined according to DIN 53 867. The corresponding values are given in addition to the values for the untreated raw material in Tables 2 and 3 below. Example 5:

A spunbonded nonwoven with a basis weight of 100 g / m ² consisting of partially split microfilaments with a titer of approx. 0.15 dtex made of 30% by weight of polyamide 66 and 70% by weight of polyethylene terephthalate was used in a jet dyeing machine (Soft-TRD , Thies, Coesfeld, Germany) in the presence of 1 g / l of a defoamer based on a preparation of fatty acid ester, 1 g / l of a dispersant based on a naphthalene sulfonate, 2g / l of a dispersant based on acrylate copolymers, 15 ml / l one 50% by weight NaOH, 8 g / l sodium hydrosulfite and 2% by weight (based on the weight of the raw material) of the vat dye Cl Vat Brown 3 colored at a liquor ratio of 1:10. The coloring took place within 60 minutes at 95 ° C. It was then rinsed with water, oxidized with 5 ml / l of a 30% by weight hydrogen peroxide solution at 60 ° C for 15 minutes and soaped at 70 ° C for 20 minutes and rinsed with cold water.

The spunbonded nonwoven thus obtained exhibits excellent pilling behavior, determined in accordance with DIN 53 867. The wash, sweat and light fastness of the spunbonded nonwoven are given in Table 1 below. Example 6:

A printing paste consisting of 70 g / kg of the Vat Vat 2 vat dye, 800 g / kg of potato starch ether thickener and 130 g / kg of water was rotated onto a spunbonded nonwoven with a basis weight of 100 g / m ² of partially split Microfilaments with a titer of approximately 0.85 dtex made of 50% by weight of polyamide 66 and 50% by weight of polyethylene terephthalate are applied. The print was dried at 100 ° C. The aqueous alkali and the reducing agent for the vat dye were then by means of Foulard applied. The padding liquor used contained about 820 g / kg

Water, 10 g / kg borax, 5 g / kg of a wetting agent based on a preparation of alkanesulfonate, 10 g / kg, potato starch ether, 55 g / kg caustic soda and 60 g / kg of a reducing agent based on an alkanesulfonate. The printed nonwoven fabric was then dried for 90 seconds at 120 ° C. and for

Fixed at 210 ° C for 90 seconds. Then it was rinsed with cold water, at 60

° C oxidized with 5 ml / l of a 30 wt .-% hydrogen peroxide solution, 20

Soaped for minutes at 70 ° C and rinsed with cold water.

The spunbonded nonwoven treated according to the invention exhibits excellent pilling behavior, determined in accordance with DIN 53 867. The wash, sweat and light fastness of the spunbonded nonwoven treated and printed according to the invention are shown in Table 1 below.

Example 7:

A ready-made, undyed shirt made of a spunbonded nonwoven with a basis weight of 100 g / m ² consisting of partially split microfilaments with a titer of approx. 0.85 dtex made of 50% by weight of polyethylene terephthalate and 50% by weight of polyamide 66 a drum dyeing machine with 1 g / l of a dispersant based on a naphthalene sulfonate, 0.5 g / l of a trisodium nitriloacetate complexing agent, 2 g / l of a dispersant based on acrylate copolymers, 4g / l of a carrier based on an N-alkyl-phthalimidecarboxylic acid compound, 3 g / l of a 80 wt% aqueous glucose, and 4 wt .-% (based on the starting weight of the raw material) Cottestren ^® dark blue DBC (DyStar) at a liquor ratio of 1: 10 colored. The pH was adjusted to 4.5 with acetic acid. Starting at 60 ° C, the mixture was heated to 98 ° C at 2.5 ° C / min and stained at 98 ° C for 70 minutes. The mixture was then cooled to 80 ° C. at 2.5 ° C./minute, 1 g / l of a preparation based on fatty acid ester was added and 17 ml / l a 50% by weight NaOH and 9 g / l hydrosulfite plus 1.1 l of a 50

% NaOH and 1.7 kg hydrosulfite per m ^{3 of} air. After this

Tubing was dyed at 80 ° C for 30 minutes, cooled to 60 ° C at 2.5 ° C / minute, rinsed with water and oxidized with 2 g / l of an oxidizing agent for vat dyes based on nitrobenzenesulfonate at 60 ° C for 15 minutes. Finally, the dyed shirt was soaped at 70 ° C for 20 minutes and rinsed with cold water.

The shirt obtained in this way shows excellent pilling behavior, determined in accordance with DIN 53 867.

Example 8:

A staple fiber nonwoven with a basis weight of 100 g / m 2, consisting of partially split microfibers with a titer of approx. 0.85 dtex from 70

% By weight of polyester and 30% by weight of polyamide-6 were mixed with 1 ml / l

Wetting agent based on a sulfonated fatty acid derivative, 20% by weight

(based on the weight of the raw material) of the sulfur dye Diresul ^®

Black RDT (Clariant, 'Germany), 30 g / l Glauber's salt, 8 g / l sodium hydrosulfite and 8 ml / l of a 50% by weight NaOH at 95 ° C for 45

Minutes colored. It was then rinsed with water and with 1.5 wt .-% of an oxidizing agent for sulfur dyes based on an inorganic

Halogen compound oxidized at 70 ° C for 20 minutes. The pH was adjusted to 3.5 with acetic acid. After the oxidation was rinsed with water, at 90 ° C with 2 g / l of a complexing agent based on

Sodium salt of an aliphatic organic acid and 2 g / l

Soaped sodium carbonate and rinsed again with water.

The spunbonded nonwoven treated according to the invention shows an excellent pilling behavior determined according to DIN 53 867 and EN ISO 12945. Table 1 :

Color fastness of spunbonded fabrics treated and dyed according to Examples 3 to 6:

S = bleeding of accompanying tissue // C = color change of the sample

Tables 2 and 3 below show the test results according to DIN 53 867. The random tumble-pilling test was carried out using the paddle method.

Table 2 below shows the assessment of the surface change according to Table 2.1.1. of DIN 53 867. The given ratings are mean values from 3 assessments. Table 3 below is the description of the

Surface change according to table 2.1.2. of DIN 53 867. The ratings given are mean values from 3 descriptions.

Table 2:

^* An untreated, undyed spunbonded nonwoven (raw material) with a basis weight of 100 g / m ² made of partially split microfilaments with a titer of approx. 0.15 dtex consisting of 30% by weight polyamide 66 and 70% by weight was used as a reference. % Polyethylene terephthalate used.

Min stands for minute or minutes

9 = no pilling

1 = very strong pilling

Table 3:

Min stands for minute or minutes

1 = no visible change 5 = very strong change

Claims

claims:

1. A method for avoiding or at least reducing the pilling of nonwoven fabrics from unsplit and / or at least partially split microfibers and / or microfilaments of synthetic polymers containing at least one polyester component and at least one polyamide component and optionally at least one polyurethane component, characterized in that the nonwoven fabric with aqueous alkali is treated.

2. The method according to claim 1, characterized in that the nonwoven fabric is used as a raw material.

3. The method according to claim 1 or 2, characterized in that the nonwoven fabric consists of at least one polyester component and at least one polyamide amide component.

4. The method according to claim 3, characterized in that the nonwoven fabric from 5 to 95 wt .-% of at least one polyester component and 95 to 5 wt .-% of at least one polyamide component, preferably from 15 to

85% by weight of at least one polyester component and 85 to 15% by weight of at least one polyamide component, particularly preferably 30 to 70% by weight of at least one polyester component and 70 to 30% by weight of at least one polyamide component.

5. The method according to any one of claims 1 to 4, characterized in that the polyamide is selected from the group consisting of polyamide 6, polyamide 66 and polyamide 11th

6. The method according to any one of claims 1 to 5, characterized in that the polyester is selected from the group consisting of

Polyethylene terephthalate, polypropylene terephthalate,

Polybutylene terephthalate, polylactic acid, their mixtures and copolyesters.

7. The method according to any one of claims 1 to 6, characterized in that the titer of the microfibers and / or microfilaments is <1 dtex.

8. The method according to any one of claims 1 to 7, characterized in that the nonwoven fabric is a stack of nonwoven fabric.

9. The method according to any one of claims 1 to 7, characterized in that the nonwoven fabric is a spunbonded nonwoven fabric.

10. The method according to any one of claims 1 to 9, characterized in that the nonwoven fabric has a basis weight of 15 to 350 g / m ² , preferably from 50 to 300 g / m ² , particularly preferably from 80 to 200 g / m ² .

11. The method according to any one of claims 1 to 10, characterized in that sodium hydroxide solution and / or potassium hydroxide solution, preferably sodium hydroxide solution, is used as the aqueous alkali.

12. The method according to any one of claims 1 to 11, characterized in that the concentration of alkali in the aqueous treatment solution 0.01 to 2 mol / l, preferably 0.1 to 1.9 mol / l, particularly preferably 0.15 to 1.75 mol / l.

13. The method according to any one of claims 1 to 12, characterized in that the treatment temperature 15 to 240 ° C, preferably 40 to 210

° C, particularly preferably 60 to 120 ° C.

14. The method according to any one of claims 1 to 13, characterized in that the treatment time is 10 seconds to 600 minutes, particularly preferably 15 seconds to 2 hours.

15. The method according to any one of claims 1 to 14, characterized in that the treatment in addition to the application of the aqueous alkali

Drying, fixation with dry heat and / or fixation with saturated steam.

16. The method according to any one of claims 1 to 15, characterized in that the nonwoven fabric, after treatment with aqueous alkali, is preferably rinsed with an acidic, aqueous solution and optionally dried.

17. The method according to any one of claims 1 to 16, characterized in that the treatment with aqueous alkali during dyeing and / or

The nonwoven is pressed.

18. The method according to claim 17, characterized in that the treatment with aqueous alkali during dyeing after the exhaust process, preferably on a nozzle dyeing machine, one

Jigger or on a reel curve.

19. The method according to claim 17, characterized in that the treatment with aqueous alkali during the dyeing after Block process, the block steaming process or the block

Thermofixing process takes place.

20. The method according to claim 17, characterized in that the treatment with aqueous alkali during printing according to one

Direct printing process, preferably according to the rotary film, flat film, Rouleaux or inkjet printing process.

21. The method according to any one of claims 1 to 16, characterized in that the treatment with aqueous alkali before printing according to the

Transfer printing process takes place.

22. The method according to any one of claims 17 to 21, characterized in that the dyeing and / or the printing of the nonwoven fabric is carried out with at least one vat and / or sulfur dye.

23. The method according to any one of claims 17 to 22, characterized in that the dyeing and / or printing of the nonwoven fabric is carried out with at least one disperse dye.