EP1703003A1 - Mass-dyed polyurethaneurea fibres, process for their production, and their use in the production of textile fabrics - Google Patents

Abstract

Basically modified carbon black (I) is used to produce dark polyurethaneurea fibers, where (I) is uniformly dispersed in the fibers in an amount of 0.05-8 wt.%. Independent claims are also included for: (1) polyurethaneurea fibers comprising 70-99.9 wt.% polyurethaneurea, 0.05-8 wt.% (I) and 0-20 wt.% additives, where (I) is uniformly dispersed in the fibers; (2) producing colored polyurethaneurea fibers by preparing a polyurethaneurea solution containing 0.05-8 wt.% (I), spinning the solution, forming fibers by drying or precipitation, and lubricating and spooling the fibers.

Description

The invention relates to elastic polyurethane urea fibers containing a basic modified carbon black, so that the color of the fiber is significantly changed, and a process for their preparation and their use for the production of textile fabrics.

The term fiber used in the present invention description includes staple fibers and continuous filaments which can be made by basically known spinning processes such as the dry spinning process, the wet spinning process or the melt spinning process.

These spinning processes are described, for example, in Polyurethane urea fibers, H. Gall and M. Kausch in Kunststoff-Handbuch 7, Polyurethane, published by G. Oertel, Carl Hanser Verlag Munich Vienna, 1993, pages 679 to 694 ,

Elastic polyurethane urea fibers from long-chain synthetic polymers which comprise at least 85% of segmented polyurethanes based on e.g. Polyethers, polyesters and / or polycarbonates are constructed, are well known. Yarns of such fibers are used to make fabrics, which in turn are used, inter alia, for corsetry, stockings, and sportswear, e.g. Swimsuits or swimming trunks are suitable.

Polyurethane urea fibers show excellent elasticity and strong extensibility in combination with high restoring forces. Due to this excellent combination of properties, they find wide use in the clothing sector. In the production of dark polyurethane-urea fiber-elasticized textiles in the clothing area, it is difficult to obtain a uniform coloring or visual appearance of the various yarns. The reason for this is that the different yarns used to make the textile have different shades of color. If, for example, the co-processed inelastic yarn is in a dark shade, a conventionally produced elastic polyurethaneurea fiber will be visible in the textile and smear through, thus disturbing the visual appearance of the textile. Another method for the production of dark polyurethaneurea fibers elasticized textiles in the clothing sector is staining with the desired dye. However, the coloring is a technically complex, additional and thus also cost-increasing process step in the production chain of the textile.

The literature describes a method to produce a dark polyurethane urea fiber.

As in the application KR-A-2002092588 described, a black polyurethane urea fiber can be obtained by the incorporation of graphite as an additive. Although the polyurethane urea fibers thus obtained are dyed and have a black color, the incorporation of carbon black into polyurethane urea fibers rapidly forms agglomerates which interfere with the spinning process due to self-clogging filters. Furthermore, by the agglomeration of the carbon black, the distribution in the fiber may be disturbed so much that the uniformity in the thickness of the fiber is no longer present. This can lead to a non-homogeneous color of the fiber, as well as thread breaks in the processing to textiles.

Like in the DE-A-10 2004 003 997 described, a dark polyurethane urea fiber can be obtained by the incorporation of dark spinel pigment based on iron oxide as an additive. Although the polyurethane urea fibers thus obtained are colored and have a dark color, they can not be processed sufficiently well in the production of the fibers. Dosing pumps, for example, may suffer damage due to abrasion when dosing the solutions containing hard spinel pigments. Thus, the incorporation of iron oxide-based dark spinel pigment as an additive into a polyurethaneurea composition can not be constant over a long period of time. Dosing fluctuations lead to different, generally ever decreasing, levels of spinel pigment in the polyurethaneurea fiber. This can result in increasingly bright appearing polyurethane urea fibers, which can then lead to undesirable color differences in further processing of the fibers into textiles.

It is an object of the present invention to provide dark polyurethane urea fibers which do not have the aforementioned disadvantages of the polyurethane urea fibers described above. Thus, during the production of the polyurethaneurea fiber, no disturbance of the spinning process due to, for example, the formation of agglomerates in the spinning solution should occur. Furthermore, during the production of the polyurethaneurea fiber, there should be no change in the color shade, as well as during processing of the polyurethaneurea fiber in the textile processing chain and in the use of the finished articles.

It has been found that the dark coloring of polyurethane urea fibers is achieved by adding a basic modified carbon black to the polyurethane urea spinning solution prior to spinning. It has been found that the mechanical yarn data of the polyurethane urea fibers are not adversely affected by this addition, do not form agglomerates that interfere with the spinning process for the production of Polyurethanharnstofffaser and shades during the spinning process or in the further processing in the textile processing chain and in the use of finished goods Don `t change. Furthermore, it was found that the incorporation of the Addition in the polyurethane urea spinning solution is possible without much effort, since the dispersibility of the basic carbon black used is excellent and a homogeneous distribution of the carbon black is obtained within the polyurethane urea fiber.

• A) 99,9 bis 70 Gew.-%, insbesondere 99,8 bis 80 Gew.-%, insbesondere bevorzugt 99,7 bis 85 Gew.-% Polyurethanharnstoffpolymer,
• B) 0,05 bis 8 Gew.-%, insbesondere 0,1 bis 5 Gew.-%, insbesondere bevorzugt 0,2 bis 3 Gew.-% basisch modifiziertem Ruß,
  wobei der basisch modifizierte Ruß gleichmäßig in der Faser verteilt ist,
  und gegebenenfalls
• C) 0 bis 20 Gew.-%, insbesondere 0 bis 15 Gew.-% Zusatzstoffe im wesentlichen enthalten.

The invention relates to polyurethane urea fibers, characterized in that they

• A) 99.9 to 70 wt .-%, in particular 99.8 to 80 wt .-%, particularly preferably 99.7 to 85 wt .-% polyurethane urea polymer,
• B) 0.05 to 8 wt .-%, in particular 0.1 to 5 wt .-%, particularly preferably 0.2 to 3 wt .-% basic modified carbon black,
  wherein the basic modified carbon black is uniformly distributed in the fiber,
  and optionally
• C) 0 to 20 wt .-%, in particular 0 to 15 wt .-% additives substantially.

The dark shade of polyurethane urea elastane yarns creates a good visual appearance of textiles produced in dark shades.

The polyurethane urea fibers according to the invention are based on segmented polyurethane urea polymers. The polymers have segmental structure, i. they consist of "crystalline" and "amorphous" blocks (so-called hard segments or soft segments).

The polyurethane urea fibers can in particular be produced from a linear homo- or copolymer having in each case one hydroxyl group at the end of the molecule and a molecular weight of 600 to 4000 g / mol, such as polyether diols, polyester diols, polyester amide diols, polycarbonate diols or a mixture or copolymers of this group , Particular preference is given to polyester diols and polyether diols, very particular preference to polyester diols, since polyester diols are stabilized without the addition of further stabilizers against degradation by chlorinated water. Furthermore, they are based on organic diisocyanates, with which the polymeric diols are converted to terminal isocyanate-functional prepolymers, and diamines or mixtures of various diamines as chain extenders, with which the terminal isocyanate-functional prepolymers are converted to high polymers.

Examples of organic diisocyanates are 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate and 4,4'-diphenylmethane diisocyanate. Examples of diamines are ethylenediamine, 1,2-propanediamine, 2-methyl-1,5-diaminopentane, isophoronediamine, 1,3-diaminocyclohexane, 1-methyl-2,4-diaminocyclohexane or 1,2-diaminocyclohexane.

The polyurethane urea fibers can be prepared by generally known methods, such as those described in the documents US 3,553,290 and US Pat. No. 3,555,115 and in Scripture WO 9 3/09 174 are described.

The basic modification of carbon black is carried out by adding a nitrogen-containing base to the carbon black before or during the incorporation into the polyurethaneurea composition and the subsequent spinning process for the production of the polyurethaneurea fiber. The amount of nitrogen-containing base added to the carbon black is 0.05 to 30%, in particular 0.1 to 20% and especially preferably 0.2 to 15%, with respect to percent by weight of carbon black.

The carbon blacks used are those whose preparation is carried out by processes known per se, such as the FurnanceRuß process, the GasRuß process or the FlammRuß process, particularly preferably by the FurnanceRuß process or the GasRuß process, and more particularly preferably according to the GasRuß method. The FurnanceRuss process is a continuous process that uses liquid and gaseous hydrocarbons. The reaction takes place at high temperatures in a ceramic lined furnace. After soot formation, the process gas mixture is cooled abruptly by injecting water. In the gas soot method, a hydrogen-containing gas is passed over a heated oil, and the carrier gas saturated with oil vapor is supplied to a burner tube carrying a plurality of small burner caps. The many small flames strike against a water-cooled roll, at which then the resulting soot separates. In the FlammRuß process, the liquid or molten raw materials are taken up in a cast-iron bowl, which is provided with a refractory lined exhaust hood and burned. The separation of the carbon black then takes place on coolers.

The nitrogen-containing bases used for the basic modification of the carbon black are aliphatic amines, in particular methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, 3-methyl-1-butanamine, hexylamine, octylamine, 2-ethylhexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, di (2-ethylhexyl) amine, trimethylamine, triethylamine, tripropylamine, tributylamine, trihexylamine, tris (2-ethylhexyl) amine, N, N-dimethylethylamine, dimethylpropylamine, N, N-dimethylisopropylamine and N, N-dimethylbutylamine, alkoxyalkylamines, in particular 2-methoxyethylamine, 3-methoxypropylamine and di (2-methoxyethyl) amine, cycloaliphatic, aliphatic-aromatic and aromatic amines, in particular cyclopentylamine, cyclohexylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine , Dicyclohexylamine, N, N-dimethylcyclohexylamine, benzylamine and ethylaniline, polyamines, especially ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, neopentanediamine, He xamethylenediamine, octamethylenediamine, isophoronediamine, 3- (methylamino) propylamine, 3- (cyclohexylamino) propylamine, 2- (diethylamino) ethylamine, 3- (dimethylamino) propylamine, 3- (diethylamino) propylamine, 1-diethylamino-4-aminopentane, N, N, N ', N'-tetramethyl-1,3-propanediamine and N, N, N', N'-tetramethyl-1,6-hexanediamine and aminohydroxy compounds, in particular monoethanolamine, 3-amino-1-propanol, isopropanolamine, 5-amino-1-pentanol, aminoethylethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, diethanolamine, 3- (2-hydroxyethylamino) -1- propanol, diisopropanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dimethylisopropanolamine, N, N-dibutylethanolamine, 3-dimethylamino-1-propanol, N-methyldiethanolamine, N-butyldiethanolamine, triethanolamine and triisopropanolamine.

Particularly preferred nitrogen-containing bases are aliphatic amines, especially those from the group propylamine, butylamine, sec-butylamine, tert-butylamine, 3-methyl-1-butanamine, hexylamine, 2-ethylhexylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine and di (2-ethylhexyl) amine, alkoxyalkylamines, in particular from the group 2-methoxyethylamine, 3-methoxypropylamine and di (2-methoxyethyl) amine, cycloaliphatic amines, especially those from the group cyclohexylamine, polyamines, in particular ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, neopentanediamine, 3- (methylamino) propylamine, 2- (diethylamino) ethylamine, 3- (diethylamino) propylamine and 1-diethylamino-4-aminopentane and aminohydroxy compounds, especially those from the group monoethanolamine, 3-amino 1-propanol, isopropanolamine, 5-amino-1-pentanol, aminoethylethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, diethanolamine, diisopropanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dime ethyl isopropylamine, N, N-dibutylethanolamine, N-methyldiethanolamine and N-butyldiethanolamine.

Very particularly preferred nitrogen-containing bases are aliphatic amines, in particular 3-methyl-1-butanamine, hexylamine, 2-ethylhexylamine, diethylamine, dibutylamine, dihexylamine and di (2-ethylhexyl) amine, polyamines, in particular ethylenediamine and 1,2-propanediamine and aminohydroxy compounds , in particular monoethanolamine, 3-amino-1-propanol, aminoethylethanolamine, N-ethylethanolamine, diethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-methyldiethanolamine and N-butyldiethanolamine.

• A) 99,9 bis 70 Gew.-%, insbesondere 99,8 bis 80 Gew.-%, insbesondere bevorzugt 99,7 bis 85 Gew.-% Polyurethanharnstoffpolymer,
• B) 0,05 bis 8 Gew.-%, insbesondere 0,1 bis 5 Gew.-%, insbesondere bevorzugt 0,2 bis 3 Gew.-% .-% basisch modifiziertem Ruß, wobei der basisch modifizierte Ruß gleichmäßig in der Faser verteilt ist und der Ruß eine BET-Oberfläche von 20 bis 550 m²/g, insbesondere von 50 bis 350 m²/g, insbesondere bevorzugt von 70 bis 300 m²/g und ganz insbesondere bevorzugt von 90 bis 250 m²/g aufweist,
  und gegebenenfalls
• C) 0 bis 20 Gew.-%, insbesondere 0 bis 15 Gew.-% Zusatzstoffe im wesentlichen enthalten.

Another object of the invention are also polyurethane urea fibers, characterized in that they

• A) 99.9 to 70 wt .-%, in particular 99.8 to 80 wt .-%, particularly preferably 99.7 to 85 wt .-% polyurethane urea polymer,
• B) 0.05 to 8 wt .-%, in particular 0.1 to 5 wt .-%, particularly preferably 0.2 to 3 wt .-% .-% basic modified carbon black, wherein the basic modified carbon black is uniformly distributed in the fiber and the carbon black has a BET surface area of from 20 to 550 m ² / g, in particular from 50 to 350 m ² / g, particularly preferably from 70 to 300 m ² / g and very particularly preferably from 90 to 250 m ² / g,
  and optionally
• C) 0 to 20 wt .-%, in particular 0 to 15 wt .-% additives substantially.

The BET surface determination is a well-known method, named after Brunauer, Emmett and Teller and includes the outer and inner surface of the soot. It is thus a measure of the total surface area of the carbon black and also includes pores and gaps of the carbon black.

Another object of the invention is the use of basic modified carbon black for the production of dark polyurethane urea fibers, wherein the basic modified carbon black from 0.05 to 8 wt .-%, in particular from 0.1 to 5 wt .-%, particularly preferably from 0, 2 to 3 wt .-% is evenly distributed in the fiber.

The basic modified carbon black can be added to the polyurethane urea spinning solution in the production of polyurethane urea fibers at any point in the processing of the composition. For example, the basic modified carbon black may be added as a powder or in the form of a dispersion to a solution, dispersion or slurry of other additives. The basic modified carbon black, when processed into fibers, may then be mixed or injected upstream with the polymer spinning solution with respect to the fiber spinning nozzles. Of course, the base-modified carbon black may also be added separately to the polymer spinning solution as a powder or in the form of a dispersion in a suitable medium. The basic-modified carbon black may further be added in the above-mentioned formulations in the usual polyurethane-urea production.

The polyurethaneurea fibers according to the invention may optionally contain as additives C) for various purposes substances such as flatting agents, fillers, antioxidants, dyes, release agents, antistatic agents, heat stabilizers, light, UV radiation, nitrogen oxides, chlorine-containing water and vapors.

Examples of antioxidants, stabilizers against heat, light, UV radiation or nitrogen oxides are stabilizers from the group of sterically hindered phenols, HALS stabilizers (h indered amine l ight s tabilizer), triazines, and benzotriazoles Benzophenpne. Examples of release agents are magnesium stearate, calcium stearate and aluminum stearate. Examples of antistatic agents are alkali metal salts of sulfosuccinic or ethylene oxide or propylene oxide-modified silicones. Examples of pigments and matting agents are titanium dioxide, zinc oxide and barium sulfate. Examples of dyes are acid dyes, disperse and pigment dyes and optical brighteners. Examples of stabilizers against degradation of the fibers by chlorine or chlorine-containing water are zinc oxide, magnesium oxide, magnesium calcium or magnesium aluminum hydroxycarbonates. The stabilizers mentioned can also be used in mixtures. The additives mentioned should preferably be metered in such amounts that they show no effects which are contrary to the basic modified carbon black.

As described above, carbon blacks may be present in polar solvents, e.g. Dimethylacetamide, dimethylformamide or dimethyl sulfoxide, which are commonly used in the dry or wet spinning process for the production of polyurethane urea fibers, in the form of agglomerates. For this reason, there is the danger that in spinning solutions with incorporated soot during the spinning process difficulties may occur due to clogging of the spinnerets, resulting in a greatly increasing nozzle pressure results and / or the distribution of carbon black in the fiber is not homogeneous and / or for the demolition of The freshly formed fibers can come before or during winding on a bobbin. When incorporating basic modified carbon black in polyurethane urea spinning solutions according to the invention, surprisingly no agglomeration occurs in the spinning solution. This ensures a long service life of the spinnerets without pressure build-up on the spinnerets, a homogeneous and constant distribution of the modified carbon black in the fiber with constant color shade and thus good operational reliability and economy in the dry or wet spinning process of the polyurethaneurea fibers according to the invention.

The invention further provides a process for the preparation of spun-dyed polyurethane urea fibers by the dry spinning or wet spinning process, preferably by the dry spinning process, by preparing the spinning solution, spinning the spinning solution with a spinneret, threading below the spinneret by removing the spinning solvent by drying or in a coagulation bath , Preparing and winding the threads, characterized in that the polyurethaneurea spinning solution prior to spinning the solution to the polyurethane urea fiber 0.05 to 8 wt .-%, in particular 0.1 to 5 wt .-%, particularly preferably 0.2 to 3 wt. - Mixed% basic modified carbon black and evenly distributed in the fiber.

Another object of the invention is the use of the polyurethaneurea fibers according to the invention for the production of elastic fabrics, knitted fabrics, knitted fabrics and other textile goods. The use of the polyurethaneurea fibers according to the invention takes place preferred in the manufacture of blended fabrics together with other synthetic based dark stains, eg polyamide, polyester or polyacrylonitrile or non-synthetic fibers, eg cotton, wool, linen or silk.

The invention will be further elucidated by the examples, which are not a limitation of the invention. All percentages are based on the total weight of the fibers unless otherwise specified.

Examples:

The polyurethaneurea spinning solution used for the following examples and the comparative examples was prepared by the following procedure:

A polyurethane urea spinning solution was prepared from a polyester diol having an average molecular weight of 2000 g / mol, which consists of adipic acid, hexanediol and neopentyl glycol, capped with methylene bis (4-phenyl diisocyanate) (MDI) and then with a mixture of ethylenediamine (EDA) and Diethylamine (DEA) was chain extended. The molecular weight of the polyester diol is based on the number average.

To prepare the polyurethaneurea spinning solution, 49.88 parts by weight of polyester diol having a molecular weight of 2000 g / mol was added with 1.00 parts by weight of 4-methyl-4-azaheptanediol-2,6 and 36.06 parts by weight of dimethylacetamide (DMAc) and 13.06 parts by weight of MDI 25 ° C, heated to 50 ° C, held for 110 minutes at this temperature and then cooled to 25 ° C to obtain an isocyanate-capped polymer having an NCO content of 2.65% NCO.

Chain extension was accomplished by rapidly mixing 100 parts by weight of the isocyanate-capped polymer into a solution consisting of 1.32 parts by weight EDA and 0.03 parts by weight DEA in 189.05 parts by weight DMAc. The solids content of the resulting polyurethane urea spinning solution was 22%.

By addition of hexamethylene diisocyanate (HDI), the molecular weight of the polyurethane urea spinning solution was adjusted so that a viscosity of 70 Pa * s at a measurement temperature of 25 ° C resulted.

The polyurethaneurea spinning solution was then admixed with a stock of additives. This stock mixture consisted of 66.6% by weight of dimethylacetamide (DMAc), 11.1% by weight of Cyanox® 1790 (1,3,5-tris (4-tert-butyl-3-hydroxy-2,5-) dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, from Cytec), 5.7% by weight of Tinuvin® 622 (polymer consisting of succinic acid and Hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol, Ciba), 16.6 wt .-% 22% polyurethaneurea spinning solution and 0.001 wt .-% of the dye Makrolex® violet (Bayer AG). This stock is added to the polyurethaneurea spinning solution such that the content of Cyanox® 1790 is 1.0% by weight, based on the total solids content.

This polyurethane urea spinning solution was then mixed with a second stock solution. This consists of 5.5% by weight Silwet® L 7607 (polyalkoxy-modified polydimethylsiloxane, viscosity: 50 mPas (at 25 ° C.), molecular weight 1000 g / mol, from OSI Specialties), 5.5% by weight Magnesium stearate, 45.0% by weight DMAC and 44.0% by weight of a 30% spinning solution and was added so as to have a magnesium stearate content of 0.30% by weight, based on the solid the polyurethane-urea polymers resulted.

This polyurethane urea spinning solution was delivered to the spinnerets. Before the spinnerets, a further stock batch was admixed to this polyurethaneurea spinning solution, which contained the following quantities of the additive for staining the polyurethaneurea spinning solution:

Example 1 (according to the invention):

1.0% by weight (based on the solids content of the polyurethaneurea spinning solution) of carbon black, as a 10% dispersion in dimethylacetamide (% by weight) with the addition of 2.0% by weight of ethylenediamine (based on carbon black) and 50% by weight .-% of a 22% polyurethaneurea spinning solution (carbon black Printex® F80, manufacturer Fa. Degussa).

Example 2 (according to the invention):

1.0% by weight (based on the solids content of the polyurethaneurea spinning solution) of carbon black, as a 10% dispersion in dimethylacetamide (% by weight) with the addition of 10.0% by weight of ethylenediamine (based on carbon black) and 50% by weight .-% of a 22% polyurethaneurea spinning solution (carbon black Printex® F80, manufacturer Fa. Degussa).

Example 3 (Invention):

1.0% by weight (based on the solids content of the polyurethaneurea spinning solution) of carbon black, as a 10% dispersion in dimethylacetamide (% by weight) with the addition of 2.0% by weight of ethylenediamine (based on carbon black) and 50% by weight .-% of a 22% polyurethaneurea spinning solution (carbon black Printex® U, manufacturer Fa. Degussa).

Example 4 (according to the invention):

1.0% by weight (based on the solids content of the polyurethaneurea spinning solution) of carbon black, as a 10% dispersion in dimethylacetamide (% by weight) with the addition of 10.0% by weight of dibutylamine (based on carbon black) and 50% by weight .-% of a 22% polyurethaneurea spinning solution (carbon black Printex® F80, manufacturer Fa. Degussa).

Comparative Example 1 (V1):

1.0% by weight (based on the solids content of the polyurethaneurea spinning solution) of carbon black, as a 10% dispersion in dimethylacetamide (% by weight) and 50% by weight of a 22% polyurethaneurea spinning solution (carbon black Printex® F80, manufacturer Fa Degussa).

Comparative Example 2 (V 2):

1.0% by weight (based on the solids content of the polyurethaneurea spinning solution) of Heucodur® Black 9-100 (copper chromite spinel pigment Cu (Fe, Cr) ₂ O ₄ , Pigment Black 28, manufactured by Heubach GmbH) as 10% strength Dispersion in dimethylacetamide (wt .-%) and 50 wt .-% of a 22% polyurethaneurea spinning solution.

Comparative Example 3 (V 3):

0.2% by weight (based on the solids content of the polyurethaneurea spinning solution) of Makrolex® Black 1 (mixture consisting of 57.0% by weight of Makrolex® Red EG Gran and 43.0% by weight of Makrolex® Green 5B Gran , Manufacturer Fa. Bayer AG) and 50 wt .-% of a 22% polyurethaneurea spinning solution.

Comparative Example 4 (V 4):

0.2% by weight (based on the solids content of the polyurethaneurea spinning solution) of Makrolex® Black 2 (mixture consisting of 15.0% by weight of Makrolex® Yellow G Gran, 65.5% by weight of Makrolex® Violet 3R Gran and 19.5% by weight of Makrolex® Green 5B Gran, manufactured by Bayer AG) and 50% by weight of a 22% spinning solution.

The finished spinning solution was spun dry by spinnerets in a spinning apparatus typical for a dry spinning process into filaments having a denier of 11 dtex, wherein four individual filaments were combined to coalescing filament yarns. The fiber preparation (Baysilone® oil M20, GE Bayer Silicones) was applied via a preparation roller, wherein 4 wt .-% based on the weight of the polyurethane urea fiber were applied. The take-off speed of the thread winders was 550 m / min.

Table 1 shows the observations that occurred during the five-day spinning process. <b><u> Table 1: </ u></b> Tabular comparison of observations during the spinning process: example number Assessment of spinning process 1 No abnormality 2 No abnormality 3 No abnormality 4 No abnormality V 1 Dope already contains agglomerates; Strong construction of nozzle pressure; Termination of the spinning process according to Id; inhomogeneous distribution of the carbon black in the filament and light color nuances V 2 Change in color shade (lightening) over spin time V 3 No abnormality V 4 No abnormality

As the examples show, the spinning process is not disturbed by the addition of basic modified carbon black according to the invention. This also applies to the additives Makrolex® Black 1 and Makrolex® Black 2.

With the addition of nonbasically modified carbon black (Comparative Example C1), agglomerates already form in the spinning solution. During the spinning process, there is a strong pressure build-up upstream of the spinneret, resulting in a discontinuation of the continuous spinning process. Furthermore, the distribution of the carbon black in the fiber is not homogeneous and there is a bright color nuance. For these reasons, non-base-modified carbon black is not suitable for producing dark polyurethane urea fibers.

With the addition of dark spinel pigment based on iron oxide (Comparative Example V 2), the color shade can not be kept constant during the spinning process. Over the spinning period, the dark polyurethane urea fiber loses color depth. The cause of this non-constant and decreasing dosage of the pigment-containing stock solution in the polyurethaneurea spinning solution may be the strong abrasion of the dark spinel pigment based on iron oxide. Thus, at the end of the spinning test, instead of 1.0% by weight only a content of 0.6% by weight of dark spinel pigment based on iron oxide with respect to the polyurethane urea fiber was found. For this reason, dark spinel pigments based on iron oxide are not suitable for the production of dark polyurethane urea fibers.

In a further experiment, the extractability of the additives used for darkening the elastane fiber was tested. For this purpose, knitting hoses, consisting of 100% of the polyurethane urea fiber, were produced by means of a knitting machine. The respective knit hoses were subjected to a laundry with per (tetrachlorethylene), as they may also occur in the processing chain for the production of textiles and in the use of the finished article. The results are summarized in Table 2. <b><u> Table 2: </ u></b> Tabular comparison of changes by per wash: example Per-cleaning 1 No abnormality 2 No abnormality 3 No abnormality V 3 Strong change of color; brightening V 4 Strong change of color; brightening

The results show that undesirably large changes in hue by the per-cleaning of the Makrolex® Black 1 and 2 dark stained polyurethane urea fibers occur in Comparative Examples V 3 and V 4.

Color changes caused by per-cleaning of the polyurethane urea fibers additized according to the invention with basicly modified carbon black do not occur.

Umwindungsgarne produced using the polyurethane urea fibers according to the invention, even after the above treatment methods no visible color differences in comparison to the Beigarns used in the production of the yarn based on natural fibers or synthetic fibers.

Claims (8)

Polyurethane urea fibers, characterized in that they are substantially A) 99.9 to 70 wt .-%, in particular 99.8 to 80 wt .-%, particularly preferably 99.7 to 85 wt .-% polyurethane urea polymer, B) 0.05 to 8 wt .-%, in particular 0.1 to 5 wt .-%, particularly preferably 0.2 to 3 wt .-% basic modified carbon black,
wherein the basic modified carbon black is uniformly distributed in the fiber,
and optionally C) 0 to 20 wt .-%, in particular 0 to 15 wt .-% additives. Polyurethane urea fibers according to claim 1, characterized in that the base-modified carbon black has a BET surface area of from 20 to 550 m ² / g, in particular from 50 to 350 m ² / g, particularly preferably from 70 to 300 m ² / g and very particularly preferably from 90 to 250 m ² / g. Polyurethane urea fibers according to claim 1 or 2, characterized in that the polyurethaneurea polymer is made from a polyesterdiol. Polyurethane urea fibers according to one of the preceding claims, characterized in that the carbon black has been basicly modified by the addition of an aliphatic amine, an alkoxyalkylamine, a cycloaliphatic, aliphatic-aromatic or aromatic amine or an aminohydroxy compound. Use of base-modified carbon black for the production of dark polyurethane urea fibers, wherein the basic-modified carbon black contains from 0.05 to 8% by weight, in particular from 0.1 to 5% by weight, particularly preferably from 0.2 to 3% by weight. % is evenly distributed in the fiber. A process for the preparation of colored polyurethane urea fibers by the dry spinning or wet spinning process, preferably by the dry spinning process, by preparing the spinning solution, spinning the spinning solution with a spinneret, forming filaments below the spinneret by removing the spinning solvent by drying or in a coagulation bath, preparing and winding the Filaments, characterized in that the polyurethaneurea spinning solution before spinning the solution to the polyurethane urea fiber from 0.05 to 8 wt .-%, in particular from 0.1 to 5 wt .-%, more preferably from 0.2 to 3 wt .-% of basic modified carbon black admixed and evenly distributed in the fiber. Use of the polyurethane urea fibers according to any one of claims 1 to 4 for the production of elastic fabrics, knitted fabrics, knitted fabrics and the like. textile goods. Use of the polyurethane urea fibers according to any one of claims 1 to 4 in the production of blended fabrics together with other synthetic-based dark stains, from the group consisting of polyamide, polyester or polyacrylonitrile or non-synthetic fibers, from the group consisting of cotton, wool, linen or silk.