A nano-monascus red pigment dyeing solution and an antibacterial dyeing method for cellulose fiber fabric

Abstract

This invention discloses a nano-red yeast rice dye solution and an antibacterial dyeing method for cellulose fiber fabrics, comprising the following steps: Weighing 10% owf chitosan and 10% owf citric acid, adding 1 / 5 of the total dye solution to deionized water, and heating at 80℃ for 5 minutes to obtain a chitosan solution. Weighing 12.5% ​​owf nano-red yeast rice dye and adding 4 / 5 of the total dye solution to deionized water to obtain a nano-red yeast rice dye suspension. Slowly pouring the chitosan solution into the nano-red yeast rice dye suspension, stirring evenly to obtain the dye solution, and impregnating the cellulose fiber fabric. After dyeing, rinsing the cellulose fiber fabric with warm water, followed by soaping. After soaping, washing with water, and drying the fabric in an oven. This invention enables the dyeing of cellulose fibers using red yeast rice dye without the participation of metal ions, and gives the cellulose fibers excellent dyeing depth and color fastness, while also imparting antibacterial properties to the fibers during dyeing.

Description

Technical Field

[0001] This invention belongs to the field of textile printing and dyeing technology, and particularly relates to a nano-red yeast rice dye solution and an antibacterial dyeing method for cellulose fiber fabrics. Background Technology

[0002] Wastewater discharge from the dyeing and printing industry has long been a major source of industrial wastewater. With increasingly stringent environmental policies, exploring new alternatives to traditional dyeing and printing methods is imperative. Natural dyes are highly compatible with the ecological environment, widely available, and possess many advantages such as being non-toxic, non-irritating, and easily degradable, gaining increasing acceptance from consumers. Using natural dyes to color textiles can satisfy people's pursuit of personalization and diversification, and has promising application prospects in the field of eco-friendly textile dyeing.

[0003] Red yeast rice pigment is a natural food coloring derived from Monascus fermentation. It boasts advantages such as being natural, non-toxic, and safe, and is widely used in food, cosmetics, and other fields. Furthermore, red yeast rice pigment also possesses antibacterial properties, and its application in textile dyeing can impart higher added value to textiles. The molecular structures of the main chemical substances constituting red yeast rice pigment are shown below:

[0004]

[0005] It is evident that red yeast rice pigment has promising applications in the textile printing and dyeing industry due to its advantages such as being edible, easily degradable, pollution-free, health-promoting, and low-cost. Applying natural red yeast rice pigment to dyeing cellulosic fiber fabrics is particularly beneficial for people with sensitive skin (especially infants and young children), and has good market and consumer acceptance prospects.

[0006] Cellulose fiber fabrics are among the most common textiles in daily life and have a significant impact on people's health (for example, cellulose fiber fabrics come into direct contact with the mouth, nose, and eyes). Currently, the vast majority of colored cellulose fiber fabrics available on the market are dyed using synthetic dyes, and the production, processing, and application of synthetic dyes pose pollution problems. Therefore, exploring cleaner and more natural dyeing methods for cellulose fiber fabrics is of great significance. Currently, patented technologies for dyeing fibers using red yeast rice pigment mainly include the following:

[0007] CN106192453A discloses a method for dyeing silk fabrics with red yeast rice. Specifically, the dyeing method of the present invention includes the following steps: adding red yeast rice and a mordant to water and adjusting the pH value to 4-5 to obtain a dyeing solution; adding silk fabrics to the dyeing solution for dyeing, washing with water, and drying to finally obtain dyed fabrics; wherein: the mordant is a mixed rare earth element containing 20-30% by weight of lanthanum trioxide and 45-55% by weight of cerium dioxide, with a concentration of 0.2-1.2 g / L.

[0008] CN108755192A discloses a method for dyeing fabrics with natural pigments after color matching. Two or three pigments selected from natural blue pigment Indigoidine, red yeast rice pigment, and red yeast rice yellow pigment are dissolved in a solvent and then mixed for color matching. Praseodymium chloride and / or lanthanum trioxide and / or sodium sulfonate are added to water to adjust the pH value to 3-6. The fabric is then added to the dyeing solution, heated to 60-90℃ for dyeing, and after washing and drying, the dyeing of the fabric is completed.

[0009] CN110698878 A discloses a method for preparing and dyeing a natural dye of red yeast rice pigment for cotton fibers, which includes the following steps: (1) Dye extraction: using water-ethanol immersion extraction method, with water-ethanol as solvent, the pigment raw material is immersed in the solvent for dye extraction treatment for 6-12 hours under water bath conditions of 20-40℃, and then solid-liquid separation treatment is performed, and the upper liquid is taken for evaporation and concentration to obtain concentrated liquid; (2) Pigment modification: according to the ratio of modifier to concentrated liquid mass of 1:1.5, the modifier is added to the concentrated liquid, and then the alkali is added, so that the mixed system is reacted and treated at 0-60℃ for 8-12 hours, and then concentrated and spray dried to obtain a natural dye of red yeast rice pigment for cotton fibers.

[0010] As can be seen from the aforementioned patented technologies, the current use of red yeast rice pigment for dyeing protein fibers and cotton fibers requires the use of mordants as fixing agents, i.e., dyeing via metal ion mordants. As mordants are metal ions, the dyed fibers cannot meet health and environmental protection requirements, and cannot avoid industrial wastewater pollution, thus affecting the green and sustainable development requirements of the textile printing and dyeing industry. Furthermore, due to the low affinity of red yeast rice pigment for cellulose fibers and poor color yield, heavy metal mordants are even more necessary, further limiting the industrial application of red yeast rice pigment in cellulose fiber dyeing. Therefore, how to achieve the dyeing of cellulose fibers using red yeast rice pigment without the participation of metal ions, and to give the cellulose fibers excellent dyeing depth and color fastness (such as wash fastness and rubbing fastness), while also imparting antibacterial properties to the fibers during dyeing, thus achieving green and environmentally friendly goals, has become a pressing problem for textile printing and dyeing technicians to solve. Summary of the Invention

[0011] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a nano-red yeast rice dye solution and an antibacterial dyeing method for cellulose fiber fabrics that can dye cellulose fibers with red yeast rice dye without the participation of metal ions, and give the cellulose fibers excellent dyeing depth and color fastness, while also imparting antibacterial properties to the fibers during dyeing.

[0012] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a nano-red yeast rice dye solution, the preparation method of which includes the following steps:

[0013] (1) Take 5-15% owf chitosan, add 5-25% owf organic acid, add 1 / 5 of the total dye solution of deionized water, and stir evenly to obtain a mixed solution.

[0014] (2) Heat the mixed solution obtained in step (1) at 70-90℃ for 4-6 minutes to fully dissolve the chitosan and obtain a chitosan solution for later use.

[0015] (3) Take another 10-15% owf of nano red yeast rice pigment, add 4 / 5 of the total dyeing solution of deionized water, and stir evenly to prepare a nano red yeast rice pigment suspension for later use.

[0016] (4) Slowly add the chitosan solution obtained in step (2) into the nano red yeast rice pigment suspension and mix thoroughly to obtain the nano red yeast rice pigment dye solution.

[0017] In the above-mentioned nano-red yeast rice dye solution, the amount of chitosan used in step (1) is 10% owf, and the amount of organic acid used is 10% owf.

[0018] In the above-mentioned nano-red yeast rice dye solution, in step (2), the mixed solution obtained is heated at 80°C for 5 minutes.

[0019] In the above-mentioned nano-red yeast rice dye solution, in step (3), the amount of nano-red yeast rice dye used is 12.5% ​​owf.

[0020] In the above-mentioned nano-red yeast rice dye solution, the organic acid in step (1) is citric acid monohydrate or acetic acid.

[0021] The nano-red yeast rice dye solution mentioned above has a particle size distribution range of 71-188 nm for the nano-red yeast rice dye used in step (3).

[0022] An antibacterial dyeing method for cellulose fiber fabrics includes the following steps:

[0023] (1) Prepare the cellulose fiber fabric to be dyed for later use;

[0024] (2) Place the cellulose fiber fabric into the nano red yeast rice dye solution, set the dyeing time to 90-150 min, the dyeing temperature to 80-100℃, and the dyeing bath ratio to 1:40-60.

[0025] (3) Take out the cellulose fiber fabric, wash it with deionized water first, and then soap it.

[0026] (4) Clean the soaped cellulose fiber fabric with deionized water;

[0027] (5) Place the washed cellulose fiber fabric into an oven to dry.

[0028] In the above-mentioned antibacterial dyeing method for cellulose fiber fabrics, in step (2), the dyeing time is set to 120 min, the dyeing temperature to 90 ℃, and the dyeing bath ratio to 1:50.

[0029] In the above-mentioned antibacterial dyeing method for cellulose fiber fabrics, in step (3), the concentration of soap flakes in the soap solution used for soap washing is 2g / L, the soap washing temperature is 70℃, and the soap washing time is 10min.

[0030] In the above-mentioned antibacterial dyeing method for cellulose fiber fabrics, the drying temperature in step (5) is 70°C.

[0031] The advantages of this invention regarding the nano-red yeast rice pigment dye solution and the antibacterial dyeing method for cellulose fiber fabrics are as follows: This invention uses environmentally friendly natural pigment dyes produced by microbial fermentation, completely eliminating the pollution problems associated with the production, processing, and dyeing applications of synthetic dyes. Using chitosan as a fixing agent fully utilizes most of the dissolved red yeast rice pigment molecules and some undissolved nano-red yeast rice pigment particles, achieving not only a strong bond between the red yeast rice pigment and the cellulose fiber fabric but also excellent dyeing depth and color fastness. Simultaneously, the dyed cellulose fiber fabric exhibits significant antibacterial properties. The nano-sized red yeast rice pigment used can be well dispersed in the dye solution, avoiding the use of organic solvents to dissolve the pigment, ensuring a clean and environmentally friendly dyeing process, and realizing green and ecological dyeing processing of cellulose fiber fabrics. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating the preparation of the nano-red yeast rice dye solution and the antibacterial dyeing process of cellulose fiber fabrics according to the present invention.

[0033] Figure 2 The image shows a towel treated with the antibacterial dyeing process of Example 2 of this invention.

[0034] Figure 3 for Figure 2 Enlarged view of part A of the towel shown;

[0035] Figure 4 An optical microscope image of the towel obtained after processing in Example 2;

[0036] Figure 5 This is a particle size distribution diagram of nano-red yeast rice pigment;

[0037] Figure 6A graph showing the change in average particle size of nano-red yeast rice pigment particles before and after heating;

[0038] Figure 7 This is an electron microscope image of cellulose fibers in a dyed fabric. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order. The term "multiple" means "two or more".

[0041] like Figure 1 As shown, a nano-red yeast rice dye solution is prepared by the following steps:

[0042] (1) Take 5-15% owf chitosan, add 5-25% owf organic acid, add 1 / 5 of the total dye solution of deionized water, and stir evenly to obtain a mixed solution.

[0043] (2) Heat the mixed solution obtained in step (1) at 70-90℃ for 4-6 minutes to fully dissolve the chitosan and obtain a chitosan solution for later use.

[0044] (3) Take another 10-15% owf of nano red yeast rice pigment, add 4 / 5 of the total dyeing solution of deionized water, and stir evenly to prepare a nano red yeast rice pigment suspension for later use.

[0045] (4) Slowly add the chitosan solution obtained in step (2) into the nano red yeast rice pigment suspension and mix thoroughly to obtain the nano red yeast rice pigment dye solution.

[0046] The organic acid is citric acid monohydrate or acetic acid. The particle size distribution range of the nano-red yeast rice pigment used in step (3) is 71-188 nm, and the average particle size is 120 nm.

[0047] The present invention discloses a method for antibacterial dyeing of cellulose fiber fabrics using a prepared nano-red yeast rice dye solution, comprising the following steps:

[0048] (1) Prepare the cellulose fiber fabric to be dyed for later use;

[0049] (2) Place the cellulose fiber fabric into the nano red yeast rice dye solution, set the dyeing time to 90-150 min, the dyeing temperature to 80-100℃, and the dyeing bath ratio to 1:40-60.

[0050] (3) Take out the cellulose fiber fabric, wash it with deionized water first, and then soap it.

[0051] (4) Clean the soaped cellulose fiber fabric with deionized water;

[0052] (5) Place the washed cellulose fiber fabric into an oven to dry.

[0053] Chitosan, as a polysaccharide, contains a large number of hydroxyl and amino groups in its molecular structure. First, under the high-temperature, acidic conditions of dyeing, chitosan macromolecules dissolve in the dye bath and form numerous hydrogen bonds with the cellulose macromolecules in cotton fibers. Second, van der Waals forces exist between chitosan and cellulose macromolecules; since both chitosan and cellulose are macromolecules, these van der Waals forces are relatively strong. Third, in the acidic dye bath, chitosan carries a positive charge, while cellulose carries a negative charge, resulting in electrostatic attraction between chitosan and cotton fibers. Fourth, under the high-temperature dyeing conditions, the cellulose macromolecules in the cotton fibers undergo intense thermal motion, and the cotton fibers fully absorb water and swell, increasing the pores between the cellulose macromolecules. This allows some chitosan molecules to enter these pores. After dyeing, as the temperature drops to room temperature, the pores between the cellulose macromolecules decrease, and some chitosan macromolecules become trapped between the cellulose macromolecules. The combined effects and mechanisms of the above four aspects enable chitosan to be firmly fixed on cellulose fibers after dyeing, significantly improving the dyeing effect (dyeing depth) and color fastness of cellulose fibers.

[0054] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0055] Comparative Example 1

[0056] This comparative example did not add chitosan and citric acid, and directly used nano-red yeast rice pigment to prepare dye solution for dyeing cellulose fiber fabrics. The specific process is as follows:

[0057] Weigh out 12.5% ​​owf nano-red yeast rice pigment and add it to deionized water, stirring until homogeneous to prepare the dye solution. Immerse the cellulose fiber fabric at 90℃ for 120 minutes, with a liquor ratio of 1:50. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap it. The soap solution used for soaping has a soap flake concentration of 2 g / L, and the soaping temperature is 70℃ for 10 minutes. After soaping, wash the fabric with warm water first, then rinse it with cold water, and finally place the fabric in an oven to dry at 70℃.

[0058] Comparative Example 2

[0059] The comparative example involved preparing a citric acid-free chitosan solution beforehand, followed by the preparation of a nano-red yeast rice dye solution. The specific process is as follows:

[0060] Weigh 10% owf chitosan and add it to 1 / 5 of the total dye liquor in deionized water. Heat at 80℃ for 5 minutes. Weigh 12.5% ​​owf nano-red yeast rice pigment and add it to 4 / 5 of the total dye liquor in deionized water to obtain a nano-red yeast rice pigment suspension. Slowly pour the chitosan solution into the nano-red yeast rice pigment suspension and stir until homogeneous to obtain the dye liquor. Immerse the cellulose fiber fabric at 90℃ for 120 minutes, with a liquor ratio of 1:50. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap it. The soap solution used for soaping has a soap flake concentration of 2 g / L, and the soaping temperature is 70℃ for 10 minutes. After soaping, wash the fabric with warm water first, then rinse it with cold water. Place the fabric in an oven to dry at 70℃.

[0061] Example 1

[0062] Weigh out 5% owf chitosan and 5% owf citric acid monohydrate, add 1 / 5 of the total dye liquor to deionized water, and heat at 70℃ for 4 minutes to obtain a chitosan solution. Weigh out 10% owf nano-red yeast rice pigment and add 4 / 5 of the total dye liquor to deionized water to obtain a nano-red yeast rice pigment suspension. Slowly pour the chitosan solution into the nano-red yeast rice pigment suspension and stir evenly to obtain the dye liquor. Immerse the cellulose fiber fabric at 80℃ for 100 minutes with a liquor ratio of 1:40. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap it. The soap solution used for soaping has a soap flake concentration of 2 g / L, the soaping temperature is 70℃, and the time is 10 minutes. After soaping, wash the fabric with warm water first, then rinse it with cold water, and then dry the fabric in an oven at 70℃.

[0063] Example 2

[0064] Weigh out 10% owf chitosan and 10% owf citric acid monohydrate, add 1 / 5 of the total dye liquor to deionized water, and heat at 80℃ for 5 minutes to obtain a chitosan solution. Weigh out 12.5% ​​owf nano-red yeast rice pigment and add 4 / 5 of the total dye liquor to deionized water to obtain a nano-red yeast rice pigment suspension. Slowly pour the chitosan solution into the nano-red yeast rice pigment suspension and stir evenly to obtain the dye liquor. Immerse the cellulose fiber fabric at 90℃ for 120 minutes with a liquor ratio of 1:50. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap it. The soap solution used for soaping has a soap flake concentration of 2 g / L, the soaping temperature is 70℃, and the time is 10 minutes. After soaping, wash the fabric with warm water first, then rinse it with cold water, and then dry the fabric in an oven at 70℃.

[0065] Example 3

[0066] Weigh out 15% owf chitosan and 25% owf citric acid monohydrate, add 1 / 5 of the total dye liquor to deionized water, and heat at 90℃ for 6 minutes to obtain a chitosan solution. Weigh out 15% owf nano-red yeast rice pigment and add 4 / 5 of the total dye liquor to deionized water to obtain a nano-red yeast rice pigment suspension. Slowly pour the chitosan solution into the nano-red yeast rice pigment suspension and stir evenly to obtain the dye liquor. Immerse the cellulose fiber fabric at 100℃ for 150 minutes, with a liquor ratio of 1:60. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap it. The soap solution used for soaping has a soap flake concentration of 2 g / L, the soaping temperature is 70℃, and the time is 10 minutes. After soaping, wash the fabric with warm water first, then rinse it with cold water, and then dry the fabric in an oven at 70℃.

[0067] This invention utilizes the prepared nano-red yeast rice pigment dye solution to perform antibacterial dyeing on cellulose fiber fabrics. The final cellulose fiber fabrics were tested, and the test results are as follows:

[0068] OWF refers to the weight of the fabric. For example, 1% OWF means that 0.01g of dye or auxiliaries are used for 1g of fabric.

[0069] Color fastness to rubbing was determined according to GB / T 3920—2008 "Textiles - Tests for Color Fastness to Rubbing". Color fastness to washing was determined according to GB / T 3921—2008 "Textiles - Tests for Color Fastness to Rubbing".

[0070] The antibacterial properties of the fabric were tested according to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method".

[0071] Table 1: Performance Test Results of Cellulose Fiber Fabrics Dyed with Nano-Red Yeast Rice Pigment

[0072] Example Test Items Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 K / S value of dyed fabric 0.2 0.3 0.4 1.3 1.3 Dry rubbing color fastness 5 5 5 5 5 wet rubbing color fastness 4-5 4-5 4-5 4-5 4-5 Colorfastness to soap washing 4-5 4-5 4-5 4-5 4-5 Color fastness to soap washing 5 5 5 5 5 Color fastness to soap washing 5 5 5 5 5 Inhibition rate against Staphylococcus aureus No obvious antibacterial effect No obvious antibacterial effect No obvious antibacterial effect 96% 96%

[0073] Note: The K / S value indicates the depth of color of the fabric; the higher the value, the deeper the color.

[0074] Colorfastness description: The colorfastness grades listed in the table range from 1 to 5, with grade 5 indicating the best colorfastness and grade 1 indicating the worst.

[0075] As shown in Table 1, a comparison of "Comparative Examples 1 and 2" and "Examples 2 and 3" reveals that the addition of chitosan and citric acid significantly affects the dyeing depth (K / S value) of cellulose fiber fabrics. Only with the simultaneous addition of both chitosan and citric acid can cellulose fiber fabrics achieve a better dyeing effect. A comparison of "Example 1" and "Examples 2 and 3" shows that the amount of citric acid added greatly affects the dyeing depth (K / S value) of cellulose fiber fabrics. When the amount of citric acid added is low, chitosan is difficult to dissolve, resulting in a very light color in the fabric. Therefore, the amount of citric acid used to ensure good dissolution of chitosan is crucial. Generally, for fabrics dyed with the same dye, the lighter the color, the higher the colorfastness. Table 1 shows that compared to "Comparative Examples 1 and 2, Example 1," the fabrics in "Examples 2 and 3," which have significantly higher color depths, do not exhibit a decrease in colorfastness. This indicates that this technology achieves higher color depths without compromising colorfastness, verifying the advanced nature of this technology.

[0076] like Figure 2-4 As shown, the present invention employs a nano-red yeast rice dyeing process, which exhibits excellent dyeing effect on cellulose fiber fabrics, with uniform dyeing and achieving the expected and satisfactory dyeing depth.

[0077] I. Regarding the staining mechanism of this invention:

[0078] The difference between this invention and the classic dyeing mechanism of traditional synthetic dyes (i.e., dyes that are entirely in a dissolved state in the dye solution) is that it can utilize and dye both most of the dissolved red yeast rice pigment molecules and some undissolved nano-red yeast rice pigment particles.

[0079] 1. The staining mechanism of red yeast rice pigment in dissolved state:

[0080] like Figure 5 , 6As shown, nano-sized red yeast rice pigment particles partially dissolve under high-temperature dyeing conditions. The smaller the pigment particles and the larger their specific surface area, the easier they dissolve under these conditions, resulting in more dissolved pigment molecules and thus more pigment molecules adhering to the fabric. The change in pigment particle size before and after heating shows that the average particle size decreased from 120 nm before heating to 40 nm after heating. This indicates that the nano-pigment partially dissolves during the dyeing process. The dissolved pigment molecules contain multiple carbonyl groups and ether bonds, enabling them to form multi-site hydrogen bonds with cellulose and chitosan, while also exhibiting van der Waals forces with these substances. Furthermore, the imino groups in the Monascorubramine and Rubropunctamine molecules of the red yeast rice pigment can bind to hydrogen ions under acidic dyeing conditions, creating an attractive charge between them and cotton fibers. Additionally, the strong bond between chitosan and cotton fibers forms a film on the fiber surface, preventing the red yeast rice pigment from detaching and thus contributing to color fixation.

[0081] 2. Dyeing mechanism of undissolved red yeast rice pigment nanoparticles:

[0082] like Figure 7 As shown, electron microscopy reveals that undissolved nano-pigment particles are coated and adhered to by chitosan, thus fixing them onto the fiber surface. Because chitosan forms a film on the fiber surface after firmly binding with the cotton fiber, it not only firmly encapsulates the dissolved red yeast rice pigment molecules inside and on the surface of the cotton fiber, but the film structure also encapsulates and adheres the undissolved nano-sized pigment particles inside the film and fixes them to the fiber surface. The dissolved chitosan acts as a coating, enabling further dyeing utilization of the undissolved red yeast rice pigment particles. This overcomes the low affinity of red yeast rice pigment for cellulose fibers and the resulting color difference, improving dyeing depth and color fixation effect.

[0083] II. Factors Affecting Staining Results

[0084] 1. Pigment Dosage: The amount of pigment used in this invention has a significant impact on the color depth of the fabric. As is well known, under the same conditions, a small amount of pigment results in a lighter color, while a large amount results in a darker color. However, in this invention, after reaching the optimal dosage, the color depth of the fabric no longer increases with the increase of pigment dosage. Therefore, selecting an appropriate amount of pigment not only achieves excellent dyeing results but also minimizes production costs.

[0085] 2. Chitosan Dosage: Given the dual color-fixing function of chitosan ("dissolving + undissolving"), the amount of chitosan used in this invention has a significant impact on the color depth of the fabric. Chitosan plays a color-fixing role; the greater the amount of chitosan used, the better the color-fixing effect and the darker the fabric color. However, after reaching the optimal dosage, the color depth of the fabric no longer increases with further increases in chitosan dosage.

[0086] 3. Dyeing Temperature: The dyeing temperature of this invention has a significant impact on the color depth of the fabric. Tests have shown that the K / S value of fabric dyed at 90℃ is approximately three times that at 70℃. This is because higher temperatures facilitate the dissolution of nano-sized red yeast rice pigment particles, and the dyeing of the dissolved pigment molecules onto the fabric has a substantial effect on the color depth.

[0087] 4. Dyeing Time: Dyeing time has a significant impact on the color depth of the fabric. Tests have shown that the K / S value of fabric dyed for 120 minutes is approximately three times that of fabric dyed for 30 minutes. According to the classic dyeing mechanism of synthetic dyes (i.e., for dyes where all dye in the dye bath is in a dissolved state), dyeing for 30-60 minutes can generally achieve the maximum color depth. However, this invention requires 120 minutes to allow for partial dissolution of the nano-pigment under high-temperature conditions. After the dissolved pigment molecules are applied to the fabric, the undissolved nano-pigment particles can further dissolve and continue to apply to the fabric, maximizing the solubility of the nano-red yeast rice pigment particles and increasing the dyeing depth.

[0088] This invention enables antibacterial dyeing of regenerated cellulose fiber fabrics such as viscose, lyocell, modal, or cupro fabrics using this antibacterial dyeing method. This invention develops a novel method for antibacterial dyeing of cellulose fiber fabrics using nano-red yeast rice pigment. First, chitosan is dissolved under acidic conditions by heating. Then, the prepared chitosan solution is added to a suspension of nano-red yeast rice pigment to prepare the final dye solution. The optimal dyeing method was determined through dyeing process exploration, achieving strong dyeing of cellulose fiber fabrics with nano-red yeast rice pigment. The dyed fabrics exhibit excellent wash fastness and rubbing fastness, and show excellent antibacterial activity against Staphylococcus aureus. The dyes and auxiliaries required in this process, including red yeast rice pigment, chitosan, and citric acid, are all natural products, making them green, environmentally friendly, and sustainable.

[0089] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A nano-red yeast rice dye solution, characterized in that, The preparation method includes the following steps: (1) Take 5-15% owf chitosan, add 5-25% owf organic acid, add 1 / 5 of the total dye solution of deionized water, and stir evenly to obtain a mixed solution. (2) Heat the mixed solution obtained in step (1) at 70-90℃ for 4-6 minutes to fully dissolve the chitosan and obtain a chitosan solution for later use. (3) Take another 10-15% owf of nano red yeast rice pigment, add 4 / 5 of the total dyeing solution of deionized water, and stir evenly to prepare a nano red yeast rice pigment suspension for later use. (4) Slowly add the chitosan solution obtained in step (2) into the nano red yeast rice pigment suspension and mix thoroughly to obtain the nano red yeast rice pigment dye solution.

2. The nano-red yeast rice dye solution according to claim 1, characterized in that: In step (1), the amount of chitosan used is 10% owf, and the amount of organic acid used is 10% owf.

3. The nano-red yeast rice dye solution according to claim 1, characterized in that: In step (2), the prepared mixed solution is heated at 80°C for 5 minutes.

4. The nano-red yeast rice dye solution according to claim 1, characterized in that: In step (3), the amount of nano-red yeast rice pigment used is 12.5% ​​owf.

5. The nano-red yeast rice dye solution according to claim 1, characterized in that: The organic acid in step (1) is citric acid monohydrate or acetic acid.

6. The nano-red yeast rice dye solution according to claim 1, characterized in that: The particle size distribution range of the nano-red yeast rice pigment used in step (3) is 71-188 nm.

7. A method for antibacterial dyeing of cellulose fiber fabrics, characterized in that, Includes the following steps: (1) Prepare the cellulose fiber fabric to be dyed for later use; (2) Place the cellulose fiber fabric into the nano-red yeast rice dye solution according to any one of claims 1-4, set the dyeing time to 90-150 min, the dyeing temperature to 80-100℃, and the dyeing bath ratio to 1:40-60. (3) Take out the cellulose fiber fabric, wash it with deionized water first, and then soap it. (4) Clean the soaped cellulose fiber fabric with deionized water; (5) Place the cleaned cellulose fiber fabric into an oven to dry.

8. The method for antibacterial dyeing of cellulose fiber fabrics according to claim 7, characterized in that: In step (2), the dyeing time is set to 120 min, the dyeing temperature to 90 ℃, and the dyeing bath ratio to 1:

50.

9. The method for antibacterial dyeing of cellulose fiber fabrics according to claim 7, characterized in that: In step (3), the concentration of soap flakes in the soap solution used for soap washing is 2g / L, the soap washing temperature is 70℃, and the soap washing time is 10min.

10. The method for antibacterial dyeing of cellulose fiber fabrics according to claim 7, characterized in that: In step (5), the drying temperature is 70°C.

Images