Wool fiber, dyeing method of wool fiber, modified microbial dye and preparation method of modified microbial dye

Abstract

The invention relates to the technical field of fiber dyeing, in particular to a wool fiber, a dyeing method of the wool fiber, a modified microbial dye and a preparation method of the modified microbial dye, and the dyeing method comprises the following steps: S1, mixing the microbial dye, reducing sugar, alkali and an aprotic solvent according to a preset molar ratio; reacting at a first preset temperature for a first preset time under the protection of inert gas, carrying out reduced pressure distillation on the reacted product under the conditions of a first preset pressure intensity and a second preset temperature, and then drying at a third preset temperature for a second preset time to obtain the modified microbial dye, s3, the modified microbial dye is dissolved in water, the pH value is adjusted to a preset pH value, and dye liquor is formed; and completely immersing the wool fiber raw material in the dye liquor, carrying out constant-temperature dyeing at a fourth preset temperature for a third preset time, washing the dyed wool fiber raw material with deionized water for preset times, and carrying out vacuum drying at a fifth preset temperature for a fourth preset time to obtain the wool fiber.

Description

Technical Field

[0001] This disclosure relates to the field of fiber dyeing technology, and in particular to a wool fiber and its dyeing method, a modified microbial dye and its preparation method. Background Technology

[0002] Wool dyeing mainly involves using acid dyes or reactive dyes, under conditions such as the addition of large amounts of salt, dyeing auxiliaries, and boiling dyeing, to electrostatically or covalently bind with the fibers, thereby achieving the dyeing purpose. However, this dyeing method poses a serious environmental pollution problem.

[0003] Microbial pigments are brightly colored natural pigments produced by microorganisms such as bacteria, fungi, and algae. They have advantages such as wide availability, safety and environmental friendliness, and production not being limited by region or season, and have already been industrialized. However, microbial pigments have problems such as low dyeing rate and poor color fastness when used to dye textiles.

[0004] To address the aforementioned issues, existing Maillard reaction-based dyeing techniques typically employ small-molecule reducing sugars to color wool fibers. This method involves pretreating the wool fibers with hydrogen peroxide during the dyeing process to improve their surface properties, followed by in-situ dyeing with reducing sugars. This approach is characterized by its green and environmentally friendly nature and high dyeing performance. Reference 1 (Enzyme and Microbial Technology, 2007, 40(7): 1788) used laccase to catalyze the oxidation of flavonoids (rutin, morin, and quercetin) in solution to obtain quinones. These quinones were further polymerized under the action of enzymes and reacted with flavonoids on unbleached cotton fabrics, thereby coloring the cotton fabrics (unbleached cotton fabrics contain natural flavonoids). Reference 2 (Mechanism investigation on the biological dyeing of proteinfibers via laccase-mediated catalysis. Wuxi: Jiangnan University, 2017) used laccase to catalyze the grafting of amino acids such as tyrosine and tryptophan onto wool, thereby coloring the wool. Reference 3 (Industrial & Engineering Chemistry Research, 2013, 52(26): 8953-8961) used tyrosinase to catalyze the oxidation of caffeic acid and react with tyrosine and tryptophan in wool to color the wool. The above-mentioned literature is based on the reaction of reactive groups on fibers with small molecules to form a conjugated color-developing system containing large π bonds, thereby enabling in-situ dyeing of fibers. It can be seen that some reactions with color characteristics can be used to design new in-situ dyeing methods for fibers. Literature 4 (Dye-free dyeing performance of wool based on Maillard reaction. Fine Chemicals, 2023, 40(5): 1130) studied the dyeing performance of reducing sugars such as D-galactose, xylose, and D-glucose on wool fibers. It found that the dyeing uniformity of wool fabrics after dyeing was good, and the color fastness to brushing, soaping and dry / wet rubbing was high, but the light fastness was low, and its breaking strength and tensile strength were slightly reduced, making it difficult to apply in practice.

[0005] Therefore, it is of great significance to study an efficient and environmentally friendly dyeing method for wool fibers to solve the above problems. Summary of the Invention

[0006] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a wool fiber and its dyeing method, a modified microbial dye and its preparation method.

[0007] This disclosure provides a method for dyeing wool fibers, the dyeing method comprising the following steps: S1. Preparation of modified microbial dye: The four substances, namely microbial dye, reducing sugar, alkali and aprotic solvent, are mixed according to a preset molar ratio and reacted at a first preset temperature for a first preset time under inert gas protection. The product after reaction is subjected to vacuum distillation under a first preset pressure and a second preset temperature, and then dried at a third preset temperature for a second preset time to obtain the modified microbial dye. S3. In-situ dyeing: The modified microbial dye is dissolved in water, and the pH value is adjusted to the preset pH value to form a dyeing solution. The wool fiber raw material is then completely immersed in the dyeing solution and dyed at a constant temperature for a third preset time. After the dyed wool fiber raw material is washed with deionized water a preset number of times, it is vacuum dried at a fifth preset temperature for a fourth preset time to obtain wool fiber.

[0008] In one embodiment of this disclosure, the microbial dye is one of monazine, monazine, erythropoietin, erythropoietin amine, monazine, and monazine amine. The reducing sugar is one of D-glucose, D-fructose, and D-galactose; The alkali is one of LiOH, NaOH, and KOH; The aprotic solvent is one of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), propylene carbonate (PC), and N-methylpyrrolidone (NMP).

[0009] In one embodiment of this disclosure, the preset molar ratio is 1:1.1-1.3:20-30:100-1000.

[0010] In one embodiment of this disclosure, the inert gas is one of nitrogen, helium, or argon.

[0011] In one embodiment of this disclosure, the first preset temperature is 80-120°C, and the first preset duration is 1-4 hours.

[0012] In one embodiment of this disclosure, the first preset pressure is 1.33-133 Pa, and the second preset temperature is 100-150 °C.

[0013] In one embodiment of this disclosure, the third preset temperature is 80-95°C, and the second preset duration is 12-18h.

[0014] In one embodiment of this disclosure, the mass ratio of the wool fiber raw material, the modified microbial dye, and water is 1:0.2-4:10-200.

[0015] In one embodiment of this disclosure, the preset pH value is 7-10.

[0016] In one embodiment of this disclosure, the fourth preset temperature is 70-90°C, and the third preset duration is 60-240 min.

[0017] In one embodiment of this disclosure, the preset number of times is 3-5 times.

[0018] In one embodiment of this disclosure, the fifth preset temperature is 30-50°C, and the fourth preset duration is 90-180 min.

[0019] This disclosure also provides a wool fiber obtained by the dyeing method of wool fiber described in any of the above embodiments.

[0020] This disclosure also provides a method for preparing a modified microbial dye, comprising: The four substances—microbial dye, reducing sugar, alkali, and aprotic solvent—are mixed in a preset molar ratio and reacted at a first preset temperature for a first preset time under inert gas protection. The product after the reaction is subjected to vacuum distillation under a first preset pressure and a second preset temperature, and then dried at a third preset temperature for a second preset time to obtain the modified microbial dye.

[0021] In one embodiment of this disclosure, the microbial dye is one of monazine, monazine, erythropoietin, erythropoietin amine, monazine, and monazine amine. The reducing sugar is one of D-glucose, D-fructose, and D-galactose; The alkali is one of LiOH, NaOH, and KOH; The aprotic solvent is one of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), propylene carbonate (PC), and N-methylpyrrolidone (NMP).

[0022] In one embodiment of this disclosure, the preset molar ratio is 1:1.1-1.3:20-30:100-1000.

[0023] In one embodiment of this disclosure, the inert gas is one of nitrogen, helium, or argon.

[0024] In one embodiment of this disclosure, the first preset temperature is 80-120°C, and the first preset duration is 1-4 hours.

[0025] In one embodiment of this disclosure, the first preset pressure is 1.33-133 Pa, and the second preset temperature is 100-150 °C.

[0026] In one embodiment of this disclosure, the third preset temperature is 80-95°C, and the second preset duration is 12-18h.

[0027] This disclosure also provides a modified microbial dye, which is prepared by the method for preparing the modified microbial dye described in the above embodiments.

[0028] One beneficial effect of the wool fiber dyeing method disclosed herein is that it utilizes reducing sugars to modify microbial dyes, thus preparing modified microbial dyes. This not only takes advantage of the safety and environmental friendliness of microbial dyes, but also improves the dyeing performance, mechanical properties, UV resistance, and antibacterial properties of wool fibers by forming hydrogen bonds, dynamic covalent bonds, and dipole interactions between the modified microbial dyes and wool fibers during the dyeing process, through the special molecular structure of the modified microbial dyes. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0030] Figure 1 This is a flowchart of a method for dyeing wool fibers provided in one embodiment of this disclosure; Figure 2 This is Embodiment 1 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 3 This is Embodiment 1 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 4 This is Embodiment 2 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 5 This is Embodiment 2 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 6 This is embodiment 3 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 7 This is embodiment 3 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 8 This is embodiment 4 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 9 This is embodiment 4 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 10 This is embodiment 5 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 11 This is embodiment 5 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 12 This is embodiment 6 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 13 This is embodiment 6 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 14 This is embodiment 7 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 15 This is embodiment 7 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 16 This is embodiment 8 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 17 This is embodiment 8 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 18 This is embodiment 9 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 19 This is embodiment 9 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 20 This is embodiment 10 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 21 This is embodiment 10 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 22 This is embodiment 11 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 23 This is embodiment 11 of the present disclosure. carbon spectrum ( 13 (C NMR). Figure 24 This is embodiment 12 of the present disclosure. The hydrogen spectrum ( 1 H NMR), the horizontal axis PPM represents displacement; Figure 25 This is embodiment 12 of the present disclosure. carbon spectrum ( 13 C NMR). Detailed Implementation

[0031] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0032] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0033] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0034] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0035] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0036] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0037] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0038] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0039] The test methods for the relevant performance indicators in the following embodiments and comparative examples are as follows: K / S value and color difference: The K / S value of the multi-colored wool fibers prepared in each example was tested using a colorimeter under a D65 light source and a 10° viewing angle. , , The value was calculated, and the color difference ΔE was calculated according to the formula. Five points were randomly tested on each multi-colored wool fiber, and the average value was taken. The formula for calculating the color difference ΔE is as follows: In the formula, △ For brightness variation; △ For changes in red-green hue; △ This represents the variation in yellow-blue tint.

[0040] Dye uptake rate: The absorbance of the dye liquor was measured using a spectrophotometer to determine the maximum absorption wavelength. Then, the absorbance of the dye liquor before dyeing and the residual liquor after dyeing were measured at the maximum absorption wavelength. Dye uptake rate = (1-Ai / A0)×100%, where: A0 is the absorbance of the dye liquor before dyeing and Ai is the absorbance of the residual liquor after dyeing.

[0041] Color fastness to sunlight: The wool fibers prepared in each example were tested according to GB / T 8426—1998 "Textiles - Tests for color fastness to light - Color fastness to sunlight".

[0042] Color fastness to washing: The wool fibers prepared in each example were tested according to GB / T 3921—2008 "Textiles - Tests for color fastness to washing".

[0043] Color fastness to dry rubbing: The wool fibers prepared in each example were tested according to GB / T 3920—2008 "Color fastness to textiles - test for color fastness to rubbing".

[0044] Color fastness to perspiration: The wool fibers prepared in each example were tested according to GB / T 3922—2013 "Textiles - Tests for color fastness to perspiration".

[0045] Tensile strength: The wool fibers prepared in each embodiment were tested according to GB / T 27629-2011 standard.

[0046] Elongation at break: The wool fibers prepared in each example were measured according to GB / T 3923.1-2013 standard.

[0047] Antibacterial rate: The wool fibers prepared in each example were measured according to GB / T 20944.3-2008 standard.

[0048] UV protection performance: The wool fibers prepared in each example were tested according to GB / T 18830-2009 "Evaluation of UV protection performance of textiles". The UV protection factor (UPF) of the dyed samples was tested at a UV wavelength of 290-400nm. Five tests were conducted at different locations for each sample, and the average value was taken. When UPF>50, it was uniformly labeled as UPF50+, which means blocking ≥98% of ultraviolet rays (transmittance ≤2%).

[0049] The sources of some of the materials in this invention are as follows: Red yeast rice flavonoid: CAS: 74-79-3, structural formula is... .

[0050] Red yeast rice extract: CAS: 285-69-8, structural formula is... .

[0051] Erythemacin: CAS: 514-67-0, structural formula is... .

[0052] Erythromycin: CAS: 514-66-9, structural formula is... .

[0053] Red yeast rice extract: CAS: 21516-68-7, structural formula is... .

[0054] Red yeast rice extract: CAS: 3627-51-8, structural formula is... .

[0055] D-glucose: CAS: 50-99-7, structural formula is... .

[0056] D-Fructose: CAS: 57-48-7, structural formula is... .

[0057] D-Galactose: CAS: 15572-79-9, structural formula is... .

[0058] Existing wool dyeing methods primarily utilize acid dyes or reactive dyes, but these methods pose significant environmental pollution problems. While some literature has explored the use of small-molecule reducing sugars to color wool fibers, the dyed wool fibers exhibit low light fastness, reduced breaking strength, and lower tensile strength, hindering practical application. Therefore, this disclosure provides a wool fiber and its dyeing method, as well as a modified microbial dye and its preparation method. For ease of understanding, the following refers to… Figures 1-25The present invention will be described in detail with reference to the embodiments, including wool fibers and dyeing methods thereof, modified microbial dyes and their preparation methods.

[0059] This disclosure provides a method for dyeing wool fibers, the dyeing method comprising the following steps: S1, preparing modified microbial dye: mixing microbial dye, reducing sugar, alkali, and aprotic solvent in a preset molar ratio, reacting at a first preset temperature for a first preset time under inert gas protection, subjecting the reaction product to vacuum distillation under a first preset pressure and a second preset temperature, and then drying at a third preset temperature for a second preset time to obtain modified microbial dye; S3, in-situ dyeing: dissolving the modified microbial dye in water, adjusting the pH value to a preset pH value to form a dye solution; then completely immersing the wool fiber raw material in the dye solution, dyeing at a fourth preset temperature for a third preset time, washing the dyed wool fiber raw material with deionized water a preset number of times, and then vacuum drying at a fifth preset temperature for a fourth preset time to obtain wool fibers.

[0060] Specifically, refer to Figure 1 Microbial dyes can be produced on a large scale through controlled biosynthesis, without occupying arable land resources, and are not limited by seasons or geographical conditions. The production process is clean and environmentally friendly, and the byproducts are easily biodegradable, meeting the requirements of green and sustainable production. Furthermore, the molecular structure of microbial dyes is rich in active functional groups such as hydroxyl, carboxyl, and amino groups, which can directly form a stable bond with fiber materials, significantly improving dyeing rate and color fastness.

[0061] The Maillard reaction is a complex reaction between carbonyl compounds (reducing sugars) and amino compounds (amino acids and proteins) to produce brown or even black polymers. This disclosure utilizes reducing sugars to modify microbial dyes, preparing modified microbial dyes. These modified microbial dyes are then used to prepare dye solutions. During the dyeing process, the modified microbial dyes interact with the wool fibers through hydrogen bonds, dynamic covalent bonds, and dipole interactions, thereby improving the dyeing properties, mechanical properties, UV resistance, and antibacterial properties of the wool fibers.

[0062] Specifically, dyeing performance is improved: During the dyeing process, the modified microbial dye molecules contain a large number of hydroxyl groups, which can act as an effective mordant, cross-linking fiber molecules and firmly binding the pigment and fiber functional groups through chemical bonds or intermolecular forces. On the one hand, the modified microbial dye molecules have a strong affinity for both wool and microbial dye molecules, and can firmly bind with wool and modified microbial dye molecules through hydrogen bonds, promoting the diffusion of dye into the fiber interior. On the other hand, the modified microbial dye molecules can form a protective film on the fabric surface, inhibiting the desorption of modified microbial dye molecules during the dyeing process; the carbonyl groups of wool fibers and the multiple phenolic hydroxyl groups, amino groups, imino groups, etc., contained in the modified microbial dye molecules form hydrogen bonds, and at the same time, they may also generate ionic dipole interactions with the -NH3+ in the modified microbial dye molecules, forming a bond between wool fibers and modified microbial dye molecules. Cross-linking strengthens the interaction between the fiber and the modified microbial dye molecules, improving the color depth, dyeing rate, and color fastness of the fabric. The K / S value of dyed wool fibers is greatly improved because the modified microbial dye molecules have high solubility, and the pigment particles gradually dissolve on the surface. After being dyed by the modified microbial dye molecules, a large number of carboxylic acid groups are grafted onto the wool fibers. Due to the hydrogen bonds between the modified microbial dye molecules and the carboxylic acid groups, a large number of them are adsorbed onto the fiber surface. The concentration difference between the inside and outside of the fiber causes the pigment to diffuse inward. After washing, the modified microbial dye molecules are transformed into insoluble pigment lakes and fixed on the wool fibers to achieve the final dyeing.

[0063] Improved mechanical properties: As the modified microbial dye molecules undergo the Maillard reaction with the wool fibers, it is beneficial for the formation of a dyeing film on the surface of the wool fibers. The formed dyeing film can increase the network connection between fibers, improve the surface roughness of the fabric, and slightly increase the breaking strength. The introduced modified microbial dye molecules contain -NH- groups, which can combine with hydrogen ions in the dye bath, reducing the number of free hydrogen ions and thus reducing the damage to the fibers to a certain extent.

[0064] Enhanced UV resistance: During Maillard dyeing, the amino groups (mainly from lysine and arginine residues) on the surface of wool fibers react with the carbonyl groups in the modified microbial dye molecules under heating conditions. This causes the modified microbial dye molecules to firmly adhere to or cross-link on the fiber surface and superficial layer, forming a dense colored layer with a conjugated structure. The modified microbial dye molecules contain numerous aromatic rings, conjugated olefins, and heterocyclic structures, effectively absorbing high-energy ultraviolet light (especially UVB and UVA bands) and converting it into harmless heat or low-energy radiation. Simultaneously, the physical barrier formed by the reaction products on the fiber surface enhances the reflection and scattering of ultraviolet light. This synergistic effect of chemical absorption and physical shielding significantly improves the UV resistance of wool fibers.

[0065] Enhanced antibacterial properties: Due to their aromatic and highly conjugated structure, rigid modified microbial dye molecules can insert their conjugated rigid groups into the bacterial cell wall. Through contact reactions, they alter the permeability of the bacterial cell membrane, leading to the loss of nutrients and thus inactivation of the bacteria. Alternatively, they can inhibit bacterial reproduction and growth by damaging the bacterial genetic material such as DNA and RNA, or inhibit bacterial cell wall synthesis by blocking transglycosylation and transpeptidation processes, thereby achieving beneficial antibacterial properties.

[0066] In one embodiment, the microbial dye is one of monascorbic acid, monascorbine, erythropoietin, erythropoietin amine, monascorbic acid, and monascorbine amine; the reducing sugar is one of D-glucose, D-fructose, and D-galactose; the base is one of LiOH, NaOH, and KOH; and the aprotic solvent is one of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), propylene carbonate (PC), and N-methylpyrrolidone (NMP).

[0067] Specifically, monazine, monazine rubigin, erythropoietin, erythropoietin amine, monazine rubigin, and monazine rubiginamine, as microbial dyes, have the core advantages of being natural and safe, having stable color tones, rich biological functions, and controllable and sustainable production. Most of their components have no acute or subchronic toxicity, and are non-teratogenic or carcinogenic, making them widely used in food, cosmetics, and textiles. They have a complete chromatogram, covering yellow, orange, and red, and can be formulated to produce soft hues such as natural red, orange, and brown. They are not limited by region or season, and can be produced in a controlled, factory-scale manner with a short fermentation cycle.

[0068] The key advantage of using LiOH, NaOH, and KOH as bases is that they provide a strongly alkaline environment, activate reaction sites, and enable the ionization of large amounts of OH-. - This rapidly increases the pH value of the system, activates the reactive groups of the dye, and promotes efficient reaction.

[0069] Aprotic solvents are solvents without active hydrogen, so they do not interfere with the reaction and can dissolve the dye, allowing it to be truly dispersed at the molecular level, so that the modification reaction can occur uniformly.

[0070] In one embodiment, the preset molar ratio is 1:1.1-1.3:20-30:100-1000.

[0071] Specifically, the reaction is a matter of numbers between molecules, so controlling the molar ratio is to control the precise dosage of the reaction, determine whether the reaction can occur and to what extent, and at the same time reduce side reactions, reduce raw material consumption, and make the reaction system efficient and stable.

[0072] In one embodiment, the inert gas is one of nitrogen, helium, or argon.

[0073] Specifically, using nitrogen, helium, or argon as inert protective gases can effectively isolate the reaction system from contact with oxygen and moisture in the air, prevent the dyes, reducing sugars, and other reactants from being oxidized and decomposed under heating or alkaline conditions, inhibit side reactions, and improve reaction selectivity and product yield. At the same time, it can maintain the stability of the reaction system atmosphere, reduce problems such as dye color variation and structural damage, ensure the smooth progress of the modification reaction, and improve the consistency and reproducibility of product performance.

[0074] In one embodiment, the first preset temperature is 80-120℃ and the first preset duration is 1-4h.

[0075] Specifically, precise control of reaction temperature and reaction time can effectively control the reaction rate and process, ensuring that the dye modification reaction proceeds fully and stably; avoiding dye structure damage, color shift, increased side reactions, and decreased product purity caused by excessively high temperature or long reaction time; and preventing problems such as incomplete reaction, low conversion rate, and poor modification effect caused by excessively low temperature or short reaction time.

[0076] By optimizing the reaction temperature and time, the reaction selectivity and product yield can be improved, as well as the solubility, dispersibility, reactivity, and color fastness of the modified dyes. This makes the reaction system stable, controllable, and reproducible, facilitating industrial production and application.

[0077] In one embodiment, the first preset pressure is 1.33-133 Pa, and the second preset temperature is 100-150 °C.

[0078] Specifically, vacuum distillation can efficiently remove residual aprotic solvents, small molecule byproducts, and unreacted low-boiling-point substances from the system at lower temperatures, avoiding damage to the dye structure caused by high temperatures and ensuring the stability of dye color and performance; at the same time, it can improve product purity, reduce solvent residue, and facilitate subsequent separation, purification and post-processing.

[0079] The purpose of controlling the distillation pressure and temperature is to selectively remove solvents and small molecules by regulating the pressure and temperature of vacuum distillation. This ensures removal efficiency while avoiding problems such as dye structure degradation, color change, and performance deterioration caused by excessively high temperature or low pressure. It also makes the distillation process mild and controllable, safe to operate, improves product purity and yield, and ensures stable quality and good reproducibility of modified dyes.

[0080] In one embodiment, the third preset temperature is 80-95°C, and the second preset duration is 12-18h.

[0081] Specifically, drying can completely remove residual trace solvents, moisture and volatile impurities from the product, further improving the purity of the modified dye and preventing residual solvents or moisture from affecting the dye's solubility, dispersibility, dyeing performance and storage stability; at the same time, it can make the dye form a uniform solid form, which is convenient for subsequent packaging, storage, transportation and application.

[0082] Precise control of drying temperature and time serves two main purposes: first, it prevents thermal degradation, color shift, and structural damage to modified dyes caused by excessively high drying temperatures or prolonged drying times, which would affect their colorfastness and performance; second, it prevents excessive solvent or moisture residues in the product due to excessively low drying temperatures or short drying times, which would prevent the achievement of the expected purification effect and affect the storage stability and subsequent application of the dye. By rationally adjusting the drying temperature and time, the drying process can be made mild and controllable, ensuring stable quality and uniform performance of the modified dyes while maintaining drying efficiency, thus meeting the needs of industrial production and practical applications.

[0083] In one embodiment, the mass ratio of wool fiber raw material, modified microbial dye, and water is 1:0.2-4:10-200.

[0084] Specifically, in the dyeing process of wool fibers with modified dyes, precisely controlling the mass ratio of wool fibers, modified dyes, and water is crucial to ensuring dyeing effects and product quality. Its core function lies in regulating the concentration of the dyeing system, ensuring uniform dispersion of the modified dye in water, avoiding uneven dyeing, color spots, and uneven color due to excessively high dye concentration, or insufficient dyeing rate and dyeing depth due to excessively low concentration; coordinating the interaction ratio of wool fibers and dyes, promoting the full combination of modified dyes and active groups on the surface of wool fibers, improving dyeing rate and fixation rate, and enhancing color fastness; and optimizing the amount of water used, ensuring sufficient swelling of wool fibers and smooth diffusion and penetration of dyes, while avoiding water waste and subsequent wastewater treatment pressure. By rationally controlling the mass ratio of these three components, the dyeing process can be stable and controllable, ensuring uniform color and excellent brightness of the dyed wool fibers, while balancing dyeing efficiency and production costs, meeting the actual needs of industrial dyeing.

[0085] In one embodiment, the preset pH value is 7-10.

[0086] Specifically, adjusting the pH value of the dye bath can adapt to the interaction characteristics of modified dyes and wool fibers, ensuring that the active groups of the modified dyes are in an optimal reaction state. This promotes the binding of the dyes with the amino and carboxyl groups on the surface of the wool fibers, significantly improving the dyeing rate and fixation rate, and enhancing color fastness. Furthermore, it can stabilize the dye bath system, preventing the modified dyes from agglomerating, degrading, or shifting in color due to unsuitable pH, ensuring uniform and stable dyeing and avoiding defects such as uneven dyeing and color variations. In addition, it can protect the wool fibers by creating a mild dyeing environment through pH control, preventing damage to the scale structure of the wool fibers from strong acids or alkalis, thus preventing fiber brittleness and deterioration of hand feel, while maintaining the color brightness and morphological stability of the dyed wool fibers. Moreover, a suitable pH value can also regulate the dyeing reaction rate, making the dyeing process stable and controllable, improving dyeing reproducibility, and adapting to the needs of large-scale industrial dyeing production.

[0087] In one embodiment, the fourth preset temperature is 70-90°C, and the third preset duration is 60-240 min.

[0088] Specifically, precise control of dyeing temperature and duration serves several purposes. First, it regulates the dyeing reaction rate. A suitable dyeing temperature promotes the appropriate opening of wool fiber scales, facilitating the diffusion and penetration of modified dyes into the fiber interior. Simultaneously, it activates the binding reaction between the dye and the fiber's active groups, shortening the reaction cycle and improving dyeing efficiency. Second, it ensures thorough dyeing. A reasonable dyeing duration guarantees sufficient interaction between the modified dye and the wool fiber, preventing problems such as low dyeing rate, uneven dyeing, and light color due to insufficient time. Conversely, it prevents excessive dye aggregation, color shift, fiber damage, and a deteriorated hand feel due to excessive time. Third, it stabilizes the dyeing effect. Precise temperature and duration control prevents wool fiber degradation and dye structure damage caused by excessively high temperatures, or dyeing reaction stagnation caused by excessively low temperatures. This ensures uniform color, excellent brightness, and stable fastness of the dyed wool fibers, improving dyeing reproducibility and adapting to large-scale industrial dyeing production, balancing dyeing quality and production efficiency.

[0089] In one embodiment, the preset number of times is 3-5.

[0090] Specifically, washing dyed wool fibers multiple times with deionized water can effectively remove residual unreacted dyes, byproducts, and other impurities. By controlling the number of washes, the amount of residual impurities on the surface of the wool fibers can be significantly reduced, improving the purity and clarity of the product. At the same time, an appropriate number of washes helps remove excess free electrolytes from the surface, avoiding problems such as dull color, decreased wash fastness, or uneven dyeing caused by residual impurities.

[0091] In one embodiment, the fifth preset temperature is 30-50°C, and the fourth preset duration is 90-180 minutes.

[0092] Specifically, after washing with deionized water, the dyed wool fibers are vacuum dried. Precise control of the vacuum drying temperature and duration allows for the rapid and gentle removal of residual washing moisture and trace impurities from the fabric or product, preventing residual moisture from causing mold, color shift, or decreased colorfastness, thus further improving product purity and storage stability. Secondly, it protects the product's structure and performance; the vacuum environment lowers the drying temperature, preventing damage to the wool fiber scale structure caused by high-temperature drying, which can lead to fiber brittleness and a deterioration in hand feel. Furthermore, it improves drying efficiency. By controlling the temperature and duration, it avoids over-drying and fiber embrittlement due to excessively high temperatures or durations, or excessive moisture residue due to excessively low temperatures or durations, achieving a gentle and controllable drying process. Reasonable control of vacuum drying temperature and duration ensures both drying effectiveness and product quality and production efficiency, guaranteeing uniform product performance, good reproducibility, and suitability for industrial production needs.

[0093] This disclosure also provides a wool fiber, which is obtained by the dyeing method of the wool fiber of any of the above embodiments.

[0094] Specifically, by dyeing with modified microbial dyes, wool fibers can be obtained in one of three colors: red, magenta, or yellow. The K / S value of the wool fibers is 19.95-22.31, the color difference ΔE is 0.03-0.5, the dyeing rate is 80%-95%, and the color fastness to sunlight, washing, dry rubbing, and perspiration are all grade 4-5. The breaking strength is 2.6-3.5 cN / dtex, the breaking elongation is 50%-64%, and the UPF is 50+, specifically 467-524. The antibacterial rate against Escherichia coli is 99.4%-99.8%, and the antibacterial rate against Staphylococcus aureus is 99.7%-99.9%. The dyeing properties, mechanical properties, UV resistance, and antibacterial properties of wool fibers are all improved.

[0095] This disclosure also provides a method for preparing a modified microbial dye, comprising: mixing four substances—microbial dye, reducing sugar, alkali, and aprotic solvent—in a preset molar ratio, reacting them at a first preset temperature for a first preset time under inert gas protection, subjecting the reaction product to vacuum distillation under a first preset pressure and a second preset temperature, and then drying it at a third preset temperature for a second preset time to obtain the modified microbial dye.

[0096] Specifically, this disclosure utilizes reducing sugars to modify microbial dyes, thereby preparing modified microbial dyes. These modified microbial dyes possess unique molecular structures and can improve the dyeing performance, mechanical properties, UV resistance, and antibacterial properties of wool fibers.

[0097] This disclosure also provides a modified microbial dye, which is prepared by the preparation method of the modified microbial dye in the above embodiments.

[0098] Specifically, rigid microbial dye molecules possess excellent antibacterial capabilities due to their aromatic, highly conjugated structure, which can enhance the antibacterial properties of wool fibers during the dyeing process. Modified microbial dye molecules not only function as dye molecules but also as mordants. On one hand, they can form hydrogen bonds, dynamic covalent bonds, and dipole interactions with wool fibers. On the other hand, the wool fibers, through the newly formed hydrogen bonds with the modified microbial dye molecules, achieve orderly arrangement, resulting in cross-linking between molecules. This promotes the directional adsorption of bio-derived dye molecules by the wool fibers, leading to better dyeing effects and achieving high dye uptake and high color fastness.

[0099] To make the technical solutions and advantages of this disclosure clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments listed in this disclosure are only some embodiments, and other embodiments formed by arranging and combining raw materials and conditions are also within the protection scope of this disclosure.

[0100] Example 1 Reference Figure 2 , Figure 3 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Red yeast rice flavorin, D-glucose, NaOH, and DMF were added to a three-necked flask and mixed. The mixture was reacted at 80°C for 1 hour under nitrogen protection. The reaction product was then subjected to vacuum distillation at 1.33 Pa and 100°C, followed by drying at 80°C for 12 hours to obtain the modified microbial dye. The molar ratio of red yeast rice flavorin, D-glucose, NaOH, and DMF was 1:1.1:20:100.

[0101] The molecular structure of the modified microbial dye is as follows: .

[0102] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 7 to form a dye solution. The wool fiber raw material was then completely immersed in the dye solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed three times with deionized water and then vacuum dried at 30°C for 90 minutes to obtain yellow wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:0.2:10.

[0103] The final wool fiber has a K / S value of 19.95, a color difference ΔE of 0.5, a dyeing rate of 80%, and grades 4 for color fastness to sunlight, soaping, dry rubbing, and perspiration. It also has a breaking strength of 2.6 cN / dtex, a breaking elongation of 50%, and a UPF of 50+ (specifically 467). Furthermore, it exhibits an antibacterial rate of 99.4% against Escherichia coli and 99.7% against Staphylococcus aureus.

[0104] Example 2 Reference Figure 4 , Figure 5 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Red yeast rice pigment, D-glucose, KOH, and PC were added to a three-necked flask and mixed. The mixture was reacted at 85°C for 2 hours under helium protection. The reaction product was then subjected to vacuum distillation at 3.99 Pa and 105°C, followed by drying at 82°C for 12.5 hours to obtain the modified microbial dye. The molar ratio of red yeast rice pigment, D-glucose, KOH, and PC was 1:1.12:21:150.

[0105] The molecular structure of the modified microbial dye is as follows: .

[0106] (2) In situ staining: The modified microbial dye was dissolved in water, and the pH was adjusted to 7.5 to form a dye solution. The wool fiber raw material was then completely immersed in the dye solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed four times with deionized water and then vacuum dried at 32°C for 95 minutes to obtain red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye, and water was 1:0.4:20.

[0107] The final wool fiber has a K / S value of 20.07, a color difference ΔE of 0.45, a dyeing rate of 82%, and grades 4 for color fastness to sunlight, washing, dry rubbing, and perspiration. It also has a breaking strength of 2.7 cN / dtex, a breaking elongation of 51%, a UPF of 50+ (specifically 472), an antibacterial rate of 99.45% against Escherichia coli, and an antibacterial rate of 99.72% against Staphylococcus aureus.

[0108] Example 3 Reference Figure 6 , Figure 7 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Erythropoietin, D-glucose, NaOH, and NMP were added to a three-necked flask and mixed. The mixture was reacted at 90°C for 3 hours under argon protection. The reaction product was then subjected to vacuum distillation at 110°C and 6.65 Pa, and dried at 84°C for 13 hours to obtain the modified microbial dye. The molar ratio of erythropoietin, D-glucose, NaOH, and NMP was 1:1.14:22:200.

[0109] The molecular structure of the modified microbial dye is as follows: .

[0110] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 8 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After being washed 5 times with deionized water, the wool fiber raw material was vacuum dried at 34°C for 100 minutes to obtain red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:0.6:40.

[0111] The final wool fiber has a K / S value of 20.32, a color difference ΔE of 0.43, a dyeing rate of 84%, and grades 4 for color fastness to sunlight, soaping, dry rubbing, and perspiration. It also has a breaking strength of 2.8 cN / dtex, a breaking elongation of 52%, a UPF of 50+ (specifically 477), and exhibits an antibacterial rate of 99.5% against Escherichia coli and 99.75% against Staphylococcus aureus.

[0112] Example 4 Reference Figure 8 , Figure 9 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Erythromycin, D-glucose, LiOH, and DMSO were added to a three-necked flask and mixed. The mixture was reacted at 95°C for 4 hours under nitrogen protection. The product was then subjected to vacuum distillation at 13.3 Pa and 115°C, and dried at 86°C for 13.5 hours to obtain the modified microbial dye. The molar ratio of erythromycin, D-glucose, LiOH, and DMSO was 1:1.16:23:250.

[0113] The molecular structure of the modified microbial dye is as follows: .

[0114] (2) In situ staining: The modified microbial dye was dissolved in water, and the pH value was adjusted to 8.5 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed three times with deionized water and then vacuum dried at 36°C for 105 minutes to obtain purple-red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye, and water was 1:0.8:70.

[0115] The final wool fiber has a K / S value of 20.53, a color difference ΔE of 0.4, a dyeing rate of 86%, and color fastness to sunlight, soaping, dry rubbing, and perspiration of grade 4-5. Its breaking strength is 2.85 cN / dtex, breaking elongation is 53%, UPF50+ (specifically 483), and it exhibits an antibacterial rate of 99.55% against Escherichia coli and 99.78% against Staphylococcus aureus.

[0116] Example 5 Reference Figure 10 , Figure 11 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Monascus rubra, D-fructose, KOH, and DMF were added to a three-necked flask and mixed. The mixture was reacted at 100°C for 1 hour under helium protection. The reaction product was then subjected to vacuum distillation at 26.6 Pa and 120°C, and dried at 88°C for 14 hours to obtain the modified microbial dye. The molar ratio of monascus rubra, D-fructose, KOH, and DMF was 1:1.18:24:300.

[0117] The molecular structure of the modified microbial dye is as follows: .

[0118] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 9 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed four times with deionized water and then vacuum dried at 38°C for 110 minutes to obtain yellow wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:1:100.

[0119] The final wool fiber has a K / S value of 20.79, a color difference ΔE of 0.35, a dyeing rate of 88%, and color fastness to sunlight, soaping, dry rubbing, and perspiration of grade 4-5. Its breaking strength is 2.9 cN / dtex, breaking elongation is 54%, UPF50+ (specifically 490), and it exhibits an antibacterial rate of 99.6% against Escherichia coli and 99.8% against Staphylococcus aureus.

[0120] Example 6 Reference Figure 12 , Figure 13 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Red yeast rice extract, D-fructose, NaOH, and NMP were added to a three-necked flask and mixed. The mixture was reacted at 103℃ for 2 hours under nitrogen protection. The product was then subjected to vacuum distillation at 39.9 Pa and 125℃, and dried at 89℃ for 14.5 hours to obtain the modified microbial dye. The molar ratio of red yeast rice extract, D-fructose, NaOH, and NMP was 1:1.2:25:400.

[0121] The molecular structure of the modified microbial dye is as follows: .

[0122] (2) In situ staining: The modified microbial dye was dissolved in water, and the pH value was adjusted to 9.5 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After being dyed, the wool fiber raw material was washed 5 times with deionized water and then vacuum dried at 40°C for 115 minutes to obtain purple-red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye, and water was 1:1.3:120.

[0123] The final wool fiber has a K / S value of 20.91, a color difference ΔE of 0.3, a dyeing rate of 89%, and color fastness to sunlight, soaping, dry rubbing, and perspiration of grade 4-5. Its breaking strength is 2.95 cN / dtex, breaking elongation is 55%, UPF50+ (specifically 496), and its antibacterial rate against Escherichia coli is 99.65%, while its antibacterial rate against Staphylococcus aureus is 99.82%.

[0124] Example 7 Reference Figure 14 , Figure 15 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Red yeast rice flavorin, D-fructose, KOH, and DMSO were added to a three-necked flask and mixed. The mixture was reacted at 105℃ for 3 hours under argon protection. Then, vacuum distillation was carried out at 53.2 Pa and 130℃, followed by drying at 90℃ for 15 hours to obtain the modified microbial dye. The molar ratio of red yeast rice flavorin, D-fructose, KOH, and DMSO was 1:1.22:26:500.

[0125] The molecular structure of the modified microbial dye is as follows: .

[0126] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 10 to form a dye solution. The wool fiber raw material was then completely immersed in the dye solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed three times with deionized water and then vacuum dried at 42°C for 120 minutes to obtain yellow wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:1.6:140.

[0127] The final wool fiber has a K / S value of 21.27, a color difference ΔE of 0.25, a dyeing rate of 90%, and grades 5 for color fastness to sunlight, soaping, dry rubbing, and perspiration. It also has a breaking strength of 3.0 cN / dtex, a breaking elongation of 57%, a UPF of 50+ (specifically 500), and exhibits an antibacterial rate of 99.7% against Escherichia coli and 99.84% against Staphylococcus aureus.

[0128] Example 8 Reference Figure 16 , Figure 17 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Red yeast rice pigment, D-fructose, LiOH, and PC were added to a three-necked flask and mixed. The mixture was reacted at 108℃ for 4 hours under argon protection. The reaction product was then subjected to vacuum distillation at 135℃ and 66.5 Pa, and dried at 91℃ for 15.5 hours to obtain the modified microbial dye. The molar ratio of red yeast rice pigment, D-fructose, LiOH, and PC was 1:1.24:27:600.

[0129] The molecular structure of the modified microbial dye is as follows: .

[0130] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 7 to form a dye solution. The wool fiber raw material was then completely immersed in the dye solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed four times with deionized water and then vacuum dried at 44°C for 130 minutes to obtain red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:2:150.

[0131] The final wool fiber has a K / S value of 21.52, a color difference ΔE of 0.2, a dyeing rate of 91%, and grades 5 for color fastness to sunlight, soaping, dry rubbing, and perspiration. It also has a breaking strength of 3.1 cN / dtex, a breaking elongation of 59%, a UPF of 50+ (specifically 507), an antibacterial rate of 99.72% against Escherichia coli, and an antibacterial rate of 99.85% against Staphylococcus aureus.

[0132] Example 9 Reference Figure 18 , Figure 19 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Erythropoietin, D-galactose, LiOH, and DMSO were added to a three-necked flask and mixed. The mixture was reacted at 108℃ for 1 h under argon protection. The reaction product was then subjected to vacuum distillation at 79.8 Pa and 140℃, and dried at 92℃ for 16 h to obtain the modified microbial dye. The molar ratio of erythropoietin, D-galactose, LiOH, and DMSO was 1:1.26:24:700.

[0133] The molecular structure of the modified microbial dye is as follows: .

[0134] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 8 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After being washed 5 times with deionized water, the wool fiber raw material was vacuum dried at 46°C for 140 minutes to obtain red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:2.5:160.

[0135] The final wool fiber has a K / S value of 21.76, a color difference ΔE of 0.15, a dyeing rate of 92%, and grades 5 for color fastness to sunlight, washing, dry rubbing, and perspiration. It also has a breaking strength of 3.2 cN / dtex, a breaking elongation of 60%, and a UPF of 50+ (specifically 513). Furthermore, it exhibits an antibacterial rate of 99.74% against Escherichia coli and 99.86% against Staphylococcus aureus.

[0136] Example 10 Reference Figure 20 , Figure 21 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Erythromycin, D-galactose, KOH, and NMP were added to a three-necked flask and mixed. The mixture was reacted at 113°C for 2 hours under nitrogen protection. The product was then subjected to vacuum distillation at 143°C and dried at 93°C for 16.5 hours to obtain the modified microbial dye. The molar ratio of erythromycin, D-galactose, KOH, and NMP was 1:1.27:28:800.

[0137] The molecular structure of the modified microbial dye is as follows: .

[0138] (2) In situ staining: The modified microbial dye was dissolved in water and the pH was adjusted to 9 to form a dye solution. The wool fiber raw material was then completely immersed in the dye solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed three times with deionized water and then vacuum dried at 47°C for 150 minutes to obtain purple-red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye and water was 1:3:170.

[0139] The final wool fiber has a K / S value of 21.97, a color difference ΔE of 0.1, a dyeing rate of 93%, and grades 5 for color fastness to sunlight, washing, dry rubbing, and perspiration. It also has a breaking strength of 3.3 cN / dtex, a breaking elongation of 61%, and a UPF of 50+ (specifically 517). Furthermore, it exhibits an antibacterial rate of 99.76% against Escherichia coli and 99.87% against Staphylococcus aureus.

[0140] Example 11 Reference Figure 22 , Figure 23 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Monascus rubra, D-galactose, NaOH, and DMF were added to a three-necked flask and mixed. The mixture was reacted at 117°C for 3 hours under argon protection. The reaction product was then subjected to vacuum distillation at 119.7 Pa and 147°C, and dried at 94°C for 17 hours to obtain the modified microbial dye. The molar ratio of monascus rubra, D-galactose, NaOH, and DMF was 1:1.28:29:900.

[0141] The molecular structure of the modified microbial dye is as follows: .

[0142] (2) In situ staining: The modified microbial dye was dissolved in water, and the pH value was adjusted to 10 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed four times with deionized water and then vacuum dried at 48°C for 160 minutes to obtain yellow wool fiber. The mass ratio of wool fiber raw material, modified microbial dye, and water was 1:3.5:180.

[0143] The final wool fiber has a K / S value of 22.14, a color difference ΔE of 0.05, a dyeing rate of 94%, and grades 5 for color fastness to sunlight, soaping, dry rubbing, and perspiration. It also has a breaking strength of 3.4 cN / dtex, a breaking elongation of 63%, a UPF of 50+ (specifically 520), and exhibits an antibacterial rate of 99.78% against Escherichia coli and 99.88% against Staphylococcus aureus.

[0144] Example 12 Reference Figure 24 , Figure 25 A method for dyeing wool fibers, comprising the following steps: (1) Preparation of modified microbial dyes: Red yeast rice extract, D-galactose, KOH, and PC were added to a three-necked flask and mixed. The mixture was reacted at 120°C for 4 hours under helium protection. The reaction product was then subjected to vacuum distillation at 133 Pa and 150°C, and dried at 95°C for 18 hours to obtain the modified microbial dye. The molar ratio of red yeast rice extract, D-galactose, KOH, and PC was 1:1.3:30:1000.

[0145] The molecular structure of the modified microbial dye is as follows: .

[0146] (2) In situ staining: The modified microbial dye was dissolved in water, and the pH value was adjusted to 10 to form a dyeing solution. The wool fiber raw material was then completely immersed in the dyeing solution and dyed at a constant temperature. After dyeing, the wool fiber raw material was washed 5 times with deionized water and then vacuum dried at 50°C for 180 minutes to obtain purple-red wool fiber. The mass ratio of wool fiber raw material, modified microbial dye, and water was 1:4:200.

[0147] The final wool fiber has a K / S value of 22.31, a color difference ΔE of 0.03, a dyeing rate of 95%, and grades 5 for color fastness to sunlight, washing, dry rubbing, and perspiration. It also has a breaking strength of 3.5 cN / dtex, a breaking elongation of 64%, a UPF of 50+ (specifically 524), and exhibits an antibacterial rate of 99.8% against Escherichia coli and 99.9% against Staphylococcus aureus.

[0148] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for dyeing wool fibers, characterized in that, The staining method includes the following steps: S1. Preparation of modified microbial dye: The four substances, namely microbial dye, reducing sugar, alkali and aprotic solvent, are mixed according to a preset molar ratio and reacted at a first preset temperature for a first preset time under inert gas protection. The product after reaction is subjected to vacuum distillation under a first preset pressure and a second preset temperature, and then dried at a third preset temperature for a second preset time to obtain the modified microbial dye. S3. In-situ dyeing: The modified microbial dye is dissolved in water, and the pH value is adjusted to the preset pH value to form a dyeing solution. The wool fiber raw material is then completely immersed in the dyeing solution and dyed at a constant temperature for a third preset time. After the dyed wool fiber raw material is washed with deionized water a preset number of times, it is vacuum dried at a fifth preset temperature for a fourth preset time to obtain wool fiber.

2. The dyeing method for wool fibers according to claim 1, characterized in that, The microbial dye is one of the following: monazine, monazine, erythropoietin, erythropoietin, monazine, and monazine amine. The reducing sugar is one of D-glucose, D-fructose, and D-galactose; The alkali is one of LiOH, NaOH, and KOH; The aprotic solvent is one of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), propylene carbonate (PC), and N-methylpyrrolidone (NMP).

3. The dyeing method for wool fibers according to claim 2, characterized in that, The preset molar ratio is 1:1.1-1.3:20-30:100-1000.

4. The dyeing method for wool fibers according to claim 3, characterized in that, The inert gas is one of nitrogen, helium, or argon.

5. The dyeing method for wool fibers according to claim 4, characterized in that, The first preset temperature is 80-120℃, and the first preset duration is 1-4h.

6. The dyeing method for wool fibers according to claim 5, characterized in that, The first preset pressure is 1.33-133 Pa, and the second preset temperature is 100-150℃.

7. The dyeing method for wool fibers according to claim 6, characterized in that, The third preset temperature is 80-95℃, and the second preset duration is 12-18h.

8. The method for dyeing wool fibers according to claim 7, characterized in that, The mass ratio of the wool fiber raw material, modified microbial dye, and water is 1:0.2-4:10-200.

9. A method for dyeing wool fibers according to claim 8, characterized in that, The preset pH value is 7-10.

10. A method for dyeing wool fibers according to claim 9, characterized in that, The fourth preset temperature is 70-90℃, and the third preset duration is 60-240min.

11. The method for dyeing wool fibers according to claim 10, characterized in that, The preset number of times is 3-5 times.

12. The method for dyeing wool fibers according to claim 11, characterized in that, The fifth preset temperature is 30-50℃, and the fourth preset duration is 90-180min.

13. A wool fiber, characterized in that, The wool fiber is obtained by the dyeing method of wool fiber according to any one of claims 1-12.

14. A method for preparing a modified microbial dye, characterized in that, include: The four substances—microbial dye, reducing sugar, alkali, and aprotic solvent—are mixed in a preset molar ratio and reacted at a first preset temperature for a first preset time under inert gas protection. The product after the reaction is subjected to vacuum distillation under a first preset pressure and a second preset temperature, and then dried at a third preset temperature for a second preset time to obtain the modified microbial dye.

15. The method for preparing the modified microbial dye according to claim 14, characterized in that, The microbial dye is one of the following: monazine, monazine, erythropoietin, erythropoietin, monazine, and monazine amine. The reducing sugar is one of D-glucose, D-fructose, and D-galactose; The alkali is one of LiOH, NaOH, and KOH; The aprotic solvent is one of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), propylene carbonate (PC), and N-methylpyrrolidone (NMP).

16. The method for preparing the modified microbial dye according to claim 15, characterized in that, The preset molar ratio is 1:1.1-1.3:20-30:100-1000.

17. The method for preparing the modified microbial dye according to claim 16, characterized in that, The inert gas is one of nitrogen, helium, or argon.

18. The method for preparing the modified microbial dye according to claim 17, characterized in that, The first preset temperature is 80-120℃, and the first preset duration is 1-4h.

19. The method for preparing the modified microbial dye according to claim 18, characterized in that, The first preset pressure is 1.33-133 Pa, and the second preset temperature is 100-150℃.

20. The method for preparing the modified microbial dye according to claim 19, characterized in that, The third preset temperature is 80-95℃, and the second preset duration is 12-18h.

21. A modified microbial dye, characterized in that, The modified microbial dye is prepared by the method for preparing the modified microbial dye according to any one of claims 14-20.

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