Black lyocell fiber as well as preparation method and application thereof

Abstract

The invention relates to a black lyocell fiber and a preparation method and application thereof.The preparation method comprises the steps of spinning solution preparation, spinning, curing and aftertreatment, and curing comprises the following steps that fiber trickles obtained through spinning enter a first coagulating bath to be subjected to preliminary curing forming, the first coagulating bath comprises N-methyl morpholine oxide and a pyrrole monomer; and then the preliminarily formed fibers enter a second coagulating bath to be cured and formed, and the second coagulating bath comprises an oxidation polymerization agent of N-methyl morpholine oxide and pyrrole. According to the preparation method disclosed by the invention, black dyeing is synchronously completed in the fiber curing forming process based on two-stage coagulating bath treatment by utilizing the principle of color change of pyrrole monomer polymerization reaction, so that the preparation method not only has good dyeing fastness, but also has the advantages of environmental protection, high efficiency, simplification of downstream dyeing and finishing procedures and the like.

Description

Technical Field

[0001] The present invention relates to the field of textile technology, and particularly to black lyocell fiber and its preparation method and application. Background Art

[0002] Lyocell fiber is a new type of environmentally friendly cellulose fiber product prepared by solution spinning. The preparation process includes steps such as spinning solution preparation, spinning, solidification, and post-treatment. Specifically, cellulose (pulp) is directly dissolved in an organic solvent / water system to prepare a spinning solution with an appropriate concentration. Then, the spinning solution is extruded through a spinneret to form a fiber stream, and the fiber stream enters a coagulation bath for solidification and shaping, and then obtains the finished fiber through post-treatment processes such as washing, oiling, and drying.

[0003] In addition, currently, the dyeing methods of cellulose fibers (including lyocell) mainly focus on the downstream yarn or fabric end, and generally use dyeing methods such as dip dyeing or pad dyeing. Among them, the black dyes used for black cellulose fibers generally include direct dyes (such as direct black ECK, direct black 19, etc., with good water solubility but relatively poor dyeing fastness), reactive dyes (such as Yageosu TMGE reactive dyes, containing reactive groups, with good dyeing fastness but relatively complex dyeing process), sulfur dyes (such as environmentally friendly sulfur dyes, with low cost but generating sulfur-containing wastewater during dyeing), etc. Summary of the Invention

[0004] Based on this, in view of the above problems, it is necessary to provide a black lyocell fiber and its preparation method and application. The preparation method utilizes the principle of color change of pyrrole monomer polymerization reaction, and synchronously completes black dyeing during the fiber solidification and shaping process based on two-stage coagulation bath treatment, which not only has good dyeing fastness, but also has the advantages of environmental protection, high efficiency, and simplifying the downstream dyeing and finishing processes.

[0005] A preparation method of black lyocell fiber includes spinning solution preparation, spinning, solidification, and post-treatment. Among them, the solidification includes the following steps:

[0006] The fiber stream obtained by spinning enters a first coagulation bath for preliminary solidification and shaping. Among them, the first coagulation bath includes N-methylmorpholine N-oxide and pyrrole monomer;

[0007] Then, the preliminarily formed fiber enters a second coagulation bath for solidification and shaping. Among them, the second coagulation bath includes N-methylmorpholine N-oxide and an oxidation polymerization agent of pyrrole.

[0008] In one embodiment, the oxidation polymerization agent of pyrrole is selected from ferric chloride.

[0009] In one embodiment, the mass fraction of pyrrole monomer in the first coagulation bath is 1% - 5%;

[0010] And / or, the mass fraction of the pyrrole oxidizing polymerization agent in the second coagulation bath is 0.1% to 1%.

[0011] In one embodiment, the mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is greater than that in the second coagulation bath.

[0012] In one embodiment, the mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is 10% to 20%;

[0013] And / or, the mass fraction of N-methylmorpholine N-oxide in the second coagulation bath is 5% to 10%.

[0014] In one embodiment, the temperature of the first coagulation bath is greater than that of the second coagulation bath;

[0015] And / or, the time for the fiber stream to enter the first coagulation bath for preliminary solidification and shaping is greater than the time for the preliminarily shaped fiber to enter the second coagulation bath for solidification and shaping.

[0016] In one embodiment, the temperature of the first coagulation bath is 8°C to 15°C;

[0017] And / or, the temperature of the second coagulation bath is 3°C to 8°C.

[0018] In one embodiment, the time for the fiber stream to enter the first coagulation bath for preliminary solidification and shaping is 5 min to 10 min;

[0019] And / or, the time for the preliminarily shaped fiber to enter the second coagulation bath for solidification and shaping is 3 min to 5 min.

[0020] A black Lyocell fiber obtained by using the above preparation method.

[0021] A textile made of the above black Lyocell fiber.

[0022] In the preparation method of the present invention, during the process that the fiber stream obtained by spinning enters the first coagulation bath for preliminary solidification and shaping, the solvent in the fiber stream and the pyrrole monomer in the first coagulation bath will perform two-way diffusion using the concentration gradient, so that the pyrrole monomer enters the fiber interior. Then, during the process that the preliminarily solidified and shaped fiber enters the second coagulation bath for solidification and shaping, the pyrrole monomer in the fiber will undergo an in-situ polymerization reaction under the action of the oxidizing polymerization agent, and a black polymer will be in-situ generated inside the fiber, so that black dyeing is synchronously completed during the process of fiber solidification and shaping, which not only has good dyeing fastness, but also has the advantages of environmental protection, high efficiency, and simplifying the downstream dyeing and finishing processes. Detailed Embodiments

[0023] For the convenience of understanding the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, these embodiments or examples are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments or examples and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of the related listed items. The said any and all combinations include any two related listed items, any more related listed items, or the combination of all related listed items.

[0025] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous and include the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to integers, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0026] The preparation method of the black Lyocell fiber provided by the present invention includes spinning solution preparation, spinning, solidification and post-treatment.

[0027] In the step of spinning solution preparation, the pulp is directly dissolved in an aqueous solution of N-methylmorpholine N-oxide (NMMO) to obtain a spinning solution. Optionally, the pulp is selected from at least one of bamboo pulp, recycled waste paper pulp, straw pulp, cotton fiber, and agricultural and forestry waste fiber. During preparation, an aqueous solution of N-methylmorpholine N-oxide with a mass fraction of 86% - 88% is first heated to 100°C - 110°C, then the pulp is pulverized and mixed according to a mass ratio of pulp:N-methylmorpholine N-oxide aqueous solution of 1:10 - 1.2:10, and the temperature is further raised to 110°C - 120°C until the pulp is completely dissolved to obtain a uniform and stable spinning solution.

[0028] Then, the spinning solution is extruded through a spinneret orifice to form a fiber stream, and the fiber stream enters a coagulation bath for solidification and shaping.

[0029] In the present invention, the fiber stream obtained by spinning first enters a first coagulation bath for preliminary solidification and shaping, and then the preliminarily shaped fiber enters a second coagulation bath for solidification and shaping. Among them, the first coagulation bath includes N-methylmorpholine N-oxide and pyrrole monomer, and the second coagulation bath includes N-methylmorpholine N-oxide and an oxidizing polymerization agent for pyrrole.

[0030] Therefore, during the process that the fiber stream obtained by spinning in the present invention enters the first coagulation bath for preliminary solidification and shaping, the solvent in the fiber stream and the pyrrole monomer in the first coagulation bath will perform two-way diffusion using the concentration gradient, enabling the pyrrole monomer to enter the fiber interior. Then, during the process that the preliminarily solidified and shaped fiber enters the second coagulation bath for solidification and shaping, the pyrrole monomer in the fiber will undergo an in-situ polymerization reaction under the action of the oxidizing polymerization agent, and a black polymer will be generated in-situ inside the fiber, thereby synchronously completing black dyeing during the process of fiber solidification and shaping. It not only has good color fastness, but also has the advantages of environmental protection, high efficiency, and simplifying the downstream dyeing and finishing processes.

[0031] Optionally, the oxidizing polymerization agent for pyrrole is selected from iron(III) chloride (FeCl 3 ).

[0032] Optionally, the mass fraction of the pyrrole monomer in the first coagulation bath is 1% - 5%, such as 1%, 2%, 3%, 4%, 5%, etc., and the mass fraction of the oxidizing polymerization agent for pyrrole in the second coagulation bath is 0.1% - 1%, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, etc.

[0033] Optionally, the mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is greater than that in the second coagulation bath. Preferably, the mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is 10% - 20%, such as 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc., and the mass fraction of N-methylmorpholine N-oxide in the second coagulation bath is 5% - 10%, such as 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0034] Optionally, the temperature of the first coagulation bath is greater than that of the second coagulation bath. Preferably, the temperature of the first coagulation bath is 8°C - 15°C, such as 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, etc., and the temperature of the second coagulation bath is 3°C - 8°C, such as 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, etc.

[0035] Optionally, the time for the fiber stream to be initially solidified and formed in the first coagulation bath is greater than the time for the initially formed fiber to be solidified and formed in the second coagulation bath. Preferably, the time for the fiber stream to be initially solidified and formed in the first coagulation bath is 5 min to 10 min, such as 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc., and the time for the initially formed fiber to be solidified and formed in the second coagulation bath is 3 min to 5 min, such as 3 min, 4 min, 5 min, etc.

[0036] Thus, sufficient pyrrole monomers can enter the fiber and polymerize into a black polymer to complete fiber dyeing.

[0037] After solidification, the fiber is post-treated to obtain black Lyocell fiber. Among them, during post-treatment, it is first washed with water to precipitate N-methyl morpholine oxide in the fiber and remove residual iron chloride and unreacted pyrrole on the fiber surface, and then through processes such as oiling and drying to obtain the finished fiber.

[0038] Furthermore, the present invention also provides a black Lyocell fiber obtained by the described preparation method, and the black Lyocell fiber has good color fastness.

[0039] Furthermore, the present invention also provides a textile made of the described black Lyocell fiber.

[0040] Hereinafter, the black Lyocell fiber, its preparation method and application will be further described through the following specific examples.

[0041] Example 1

[0042] An aqueous solution of N-methyl morpholine with a mass fraction of 87% is injected into the dissolution kettle, heated to and maintained at 100 °C to form a stable solution. Then the crushed cotton fiber is added to the dissolution kettle, where the mass ratio of cotton fiber to the aqueous solution of N-methyl morpholine is 1:10, and the temperature is further raised to 110 °C. Mechanical stirring is maintained in the dissolution kettle until the pulp is completely dissolved to form a homogeneous and stable spinning solution.

[0043] The spinning solution is extruded through a delivery screw and a metering pump, extruded through the spinneret under pressure to form a fiber stream, and then enters the first coagulation bath for initial solidification and formation. Among them, the first coagulation bath is composed of N-methyl morpholine, pyrrole monomer and water. The mass fraction of N-methyl morpholine in the first coagulation bath is 15%, the mass fraction of pyrrole monomer in the first coagulation bath is 3%, the temperature of the first coagulation bath is 8 °C, and the time for initial solidification and formation is 5 min.

[0044] Then the preliminarily formed fibers are transferred to the second coagulation bath by a godet roll for solidification and shaping. The second coagulation bath is composed of N-methyl morpholine N-oxide, ferric chloride, and water. The mass fraction of N-methyl morpholine N-oxide in the second coagulation bath is 5%, the mass fraction of ferric chloride in the second coagulation bath is 0.5%, the temperature of the second coagulation bath is 3°C, and the solidification and shaping time is 3 min.

[0045] The solidified and shaped fibers are drawn by a draw roll and leave the second coagulation bath. A nozzle connected to a soft water pipe is installed above the draw roll to spray the fibers from top to bottom. Subsequently, black Lyocell fibers are obtained through processes such as cutting, oiling, drying, opening, and packing.

[0046] Example 2

[0047] An aqueous solution of N-methyl morpholine N-oxide with a mass fraction of 86% is injected into a dissolution kettle, heated to and maintained at 105°C to form a stable solution. Then the crushed cotton fibers are added to the dissolution kettle, where the mass ratio of cotton fibers to the aqueous solution of N-methyl morpholine N-oxide is 1.1:10. The temperature is further raised to 115°C, and mechanical stirring is maintained in the dissolution kettle until the pulp is completely dissolved to form a uniform and stable spinning solution.

[0048] The spinning solution is extruded through a spinneret by a conveying screw and a metering pump, and extruded through the spinneret holes under pressure to form fiber filaments, which then enter the first coagulation bath for preliminary solidification and shaping. The first coagulation bath is composed of N-methyl morpholine N-oxide, pyrrole monomer, and water. The mass fraction of N-methyl morpholine N-oxide in the first coagulation bath is 10%, the mass fraction of pyrrole monomer in the first coagulation bath is 1%, the temperature of the first coagulation bath is 10°C, and the preliminary solidification and shaping time is 6 min.

[0049] Then the preliminarily formed fibers are transferred to the second coagulation bath by a godet roll for solidification and shaping. The second coagulation bath is composed of N-methyl morpholine N-oxide, ferric chloride, and water. The mass fraction of N-methyl morpholine N-oxide in the second coagulation bath is 6%, the mass fraction of ferric chloride in the second coagulation bath is 0.1%, the temperature of the second coagulation bath is 4°C, and the solidification and shaping time is 4 min.

[0050] The solidified and shaped fibers are drawn by a draw roll and leave the second coagulation bath. A nozzle connected to a soft water pipe is installed above the draw roll to spray the fibers from top to bottom. Subsequently, black Lyocell fibers are obtained through processes such as cutting, oiling, drying, opening, and packing.

[0051] Example 3

[0052] Inject an aqueous solution of N-methylmorpholine N-oxide with a mass fraction of 87% into the dissolution kettle, heat it up and maintain at 110 °C to form a stable solution. Then add bamboo pulp into the dissolution kettle, where the mass ratio of bamboo pulp to the aqueous solution of N-methylmorpholine N-oxide is 1:10, continue to heat up to 120 °C, and keep mechanical stirring in the dissolution kettle until the pulp is completely dissolved to form a homogeneous and stable spinning solution.

[0053] The spinning solution is extruded through a conveying screw and a metering pump through a spinneret, and is extruded through the spinneret holes under pressure to form a fiber stream, which then enters the first coagulation bath for preliminary solidification and shaping. Among them, the first coagulation bath is composed of N-methylmorpholine N-oxide, pyrrole monomer and water. The mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is 12%, the mass fraction of pyrrole monomer in the first coagulation bath is 4%, the temperature of the first coagulation bath is 12 °C, and the time for preliminary solidification and shaping is 7 min.

[0054] Then the preliminarily formed fibers are transferred to the second coagulation bath by a godet roller for solidification and shaping. Among them, the second coagulation bath is composed of N-methylmorpholine N-oxide, ferric chloride and water. The mass fraction of N-methylmorpholine N-oxide in the second coagulation bath is 8%, the mass fraction of ferric chloride in the second coagulation bath is 0.3%, the temperature of the second coagulation bath is 6 °C, and the time for solidification and shaping is 4 min.

[0055] The solidified and shaped fibers are drawn by a draw roller and leave the second coagulation bath. A nozzle connected to a soft water pipeline is installed above the draw roller to spray the fibers from top to bottom. Then, through processes such as cutting, oiling, drying, opening, and packing, black Lyocell fibers are obtained.

[0056] Example 4

[0057] Inject an aqueous solution of N-methylmorpholine N-oxide with a mass fraction of 88% into the dissolution kettle, heat it up and maintain at 100 °C to form a stable solution. Then add bamboo pulp into the dissolution kettle, where the mass ratio of bamboo pulp to the aqueous solution of N-methylmorpholine N-oxide is 1.2:10, continue to heat up to 110 °C, and keep mechanical stirring in the dissolution kettle until the pulp is completely dissolved to form a homogeneous and stable spinning solution.

[0058] The spinning solution is extruded through a conveying screw and a metering pump through a spinneret, and is extruded through the spinneret holes under pressure to form a fiber stream, which then enters the first coagulation bath for preliminary solidification and shaping. Among them, the first coagulation bath is composed of N-methylmorpholine N-oxide, pyrrole monomer and water. The mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is 20%, the mass fraction of pyrrole monomer in the first coagulation bath is 5%, the temperature of the first coagulation bath is 15 °C, and the time for preliminary solidification and shaping is 5 min.

[0059] Then the preliminarily formed fibers are transferred to the second coagulation bath through a godet roll for solidification and shaping. The second coagulation bath is composed of N-methylmorpholine N-oxide, ferric chloride, and water. The mass fraction of N-methylmorpholine N-oxide in the second coagulation bath is 10%, the mass fraction of ferric chloride in the second coagulation bath is 1%, the temperature of the second coagulation bath is 8 °C, and the solidification and shaping time is 3 min.

[0060] The solidified and shaped fibers are drawn by a draw roll and leave the second coagulation bath. A nozzle connected to a soft water pipeline is installed above the draw roll to spray the fibers from top to bottom. Subsequently, black Lyocell fibers are obtained through processes such as cutting, oiling, drying, opening, and packing.

[0061] Example 5

[0062] An aqueous solution of N-methylmorpholine N-oxide with a mass fraction of 88% is injected into a dissolution kettle, heated to 105 °C and maintained to form a stable solution. Then the recycled waste paper pulp is added to the dissolution kettle, where the mass ratio of the recycled waste paper pulp to the aqueous solution of N-methylmorpholine N-oxide is 1:10. The temperature is further raised to 120 °C, and mechanical stirring is maintained in the dissolution kettle until the pulp is completely dissolved to form a uniform and stable spinning solution.

[0063] The spinning solution is extruded through a conveying screw and a metering pump through a spinneret, extruded through the spinneret holes under pressure to form fiber filaments, and then enters the first coagulation bath for preliminary solidification and shaping. The first coagulation bath is composed of N-methylmorpholine N-oxide, pyrrole monomer, and water. The mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is 15%, the mass fraction of pyrrole monomer in the first coagulation bath is 2%, the temperature of the first coagulation bath is 10 °C, and the preliminary solidification and shaping time is 10 min.

[0064] Then the preliminarily formed fibers are transferred to the second coagulation bath through a godet roll for solidification and shaping. The second coagulation bath is composed of N-methylmorpholine N-oxide, ferric chloride, and water. The mass fraction of N-methylmorpholine N-oxide in the second coagulation bath is 5%, the mass fraction of ferric chloride in the second coagulation bath is 0.2%, the temperature of the second coagulation bath is 5 °C, and the solidification and shaping time is 5 min.

[0065] The solidified and shaped fibers are drawn by a draw roll and leave the second coagulation bath. A nozzle connected to a soft water pipeline is installed above the draw roll to spray the fibers from top to bottom. Subsequently, black Lyocell fibers are obtained through processes such as cutting, oiling, drying, opening, and packing.

[0066] Example 6

[0067] Inject an aqueous solution of N-methylmorpholine N-oxide with a mass fraction of 87% into the dissolution kettle, heat it up and maintain at 100 °C to form a stable solution. Then add straw pulp to the dissolution kettle, where the mass ratio of straw pulp to the aqueous solution of N-methylmorpholine N-oxide is 1.1:10. Continue to heat up to 115 °C, and maintain mechanical stirring in the dissolution kettle until the pulp is completely dissolved to form a uniform and stable spinning solution.

[0068] The spinning solution is extruded through a conveying screw and a metering pump and passes through a spinneret. Under pressure, it is extruded through the spinneret holes to form fiber filaments, which then enter the first coagulation bath for preliminary solidification and shaping. Among them, the first coagulation bath is composed of N-methylmorpholine N-oxide, pyrrole monomer and water. The mass fraction of N-methylmorpholine N-oxide in the first coagulation bath is 16%, the mass fraction of pyrrole monomer in the first coagulation bath is 4%, the temperature of the first coagulation bath is 12 °C, and the time for preliminary solidification and shaping is 6 min.

[0069] Then the preliminarily formed fibers are transferred to the second coagulation bath by a godet roller for solidification and shaping. Among them, the second coagulation bath is composed of N-methylmorpholine N-oxide, ferric chloride and water. The mass fraction of N-methylmorpholine N-oxide in the second coagulation bath is 8%, the mass fraction of ferric chloride in the second coagulation bath is 0.8%, the temperature of the second coagulation bath is 5 °C, and the time for solidification and shaping is 4 min.

[0070] The solidified and shaped fibers are drawn by a draw roller and leave the second coagulation bath. A nozzle connected to a soft water pipeline is installed above the draw roller to spray the fibers from top to bottom. Then, through processes such as cutting, oiling, drying, opening, and packing, black Lyocell fibers are obtained.

[0071] Perform performance tests on the black Lyocell fibers obtained in Examples 1 - 6 according to "GB / T 3921-2008 Textiles - Tests for colour fastness - Colour fastness to soaping". The results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0076] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for preparing black lyocell fiber, comprising preparation of spinning solution, spinning, curing and post-treatment, characterized in that: The curing comprises the following steps: The fiber stream obtained by spinning enters the first coagulation bath for preliminary solidification and forming, wherein the first coagulation bath comprises N-methylmorpholine oxide and pyrrole monomer; Then the initially formed fiber enters into a second coagulation bath for solidification and forming, wherein the second coagulation bath comprises an oxidative polymerization agent of N-methylmorpholine oxide and pyrrole.

2. The method for preparing black lyocell fiber according to claim 1, wherein The oxidative polymerization agent of pyrrole is selected from ferric chloride.

3. The method for preparing black lyocell fiber according to claim 1, characterized in that: The mass fraction of the pyrrole monomer in the first coagulation bath is 1% to 5%; And / or, the mass fraction of the oxidative polymerization agent of pyrrole in the second coagulation bath is 0.1% to 1%.

4. The method for preparing black lyocell fiber according to claim 1, characterized in that: The mass fraction of N-methylmorpholine oxide in the first coagulation bath is greater than the mass fraction of N-methylmorpholine oxide in the second coagulation bath.

5. The method for preparing black lyocell fiber according to claim 4, characterized in that: The mass fraction of N-methylmorpholine oxide in the first coagulation bath is 10% to 20%; And / or, the mass fraction of N-methylmorpholine oxide in the second coagulation bath is 5% to 10%.

6. The method for preparing black lyocell fiber according to claim 1, characterized in that: The temperature of the first coagulation bath is greater than the temperature of the second coagulation bath; And / or, the time for the fiber stream to enter the first coagulation bath for initial solidification and forming is greater than the time for the initially formed fibers to enter the second coagulation bath for solidification and forming.

7. The method for preparing black lyocell fiber according to claim 6, characterized in that: The temperature of the first coagulation bath is 8°C to 15°C; And / or, the temperature of the second coagulation bath is 3°C to 8°C.

8. The method for preparing black lyocell fiber according to claim 6, characterized in that: The time for the fiber stream to enter the first coagulation bath for initial solidification and shaping is 5 to 10 minutes; And / or, the time for the initially formed fiber to enter the second coagulation bath for curing and forming is 3 minutes to 5 minutes.

9. A black lyocell fiber obtained by the preparation method according to any one of claims 1 to 8.

10. A textile fabric made from the black lyocell fiber according to claim 9.

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