Nano monascus red pigment dye liquor and antibacterial dyeing method of cellulosic fiber fabric

Abstract

The invention discloses a nano monascus red pigment dye liquor and an antibacterial dyeing method of cellulosic fiber fabric, and the method comprises the following steps: weighing 10% owf of chitosan and 10% owf of citric acid, adding deionized water accounting for 1 / 5 of the total dye liquor, and heating at 80 DEG C for 5 min to obtain a chitosan solution; weighing 12.5% owf of nano monascus red pigment, and adding deionized water accounting for 4 / 5 of the total dye liquor to obtain nano monascus red pigment turbid liquid; and slowly pouring the chitosan solution into the nano monascus red pigment turbid liquid, uniformly stirring to obtain a dye solution, and dip-dyeing the cellulosic fiber fabric with the dye solution. After dyeing is finished, the cellulosic fiber fabric is washed with warm water and then soaped. And washing after soaping, and drying the fabric in a drying oven. According to the present invention, the cellulose fiber can be dyed by using the monascus red pigment without the participation of metal ions, the cellulose fiber has excellent dyeing depth and excellent color fastness, and the fiber can be endowed with the antibacterial property while the dyeing is performed.

Description

Technical Field

[0001] The invention belongs to the technical field of textile printing and dyeing, and in particular relates to a nano monascus red pigment dye solution and an antibacterial dyeing method for cellulose fiber fabrics. Background Art

[0002] Wastewater discharge from the printing and dyeing industry has always been the main source of industrial wastewater. With increasingly stringent environmental protection policies, it is imperative to explore new methods to replace traditional printing and dyeing. Natural dyes are highly compatible with the ecological environment, have a wide range of sources, and have many advantages such as non-toxicity, non-irritation, and easy degradation. They are recognized by more and more consumers. Dyeing textiles with natural dyes can meet people's pursuit of personalization and diversification, and has good application prospects in the field of textile ecological dyeing.

[0003] Monascus red pigment is a natural food pigment derived from Monascus fermentation. It has the advantages of being natural, non-toxic and safe, and is widely used in many fields such as food and cosmetics. In addition, Monascus red pigment also has antibacterial functions. Applying it in the field of textile dyeing can give textiles a higher added value. The molecular structure of the main chemical substances that make up Monascus red pigment is as follows:

[0004]

[0005] It can be seen that red pigment has good application prospects in the field of textile printing and dyeing due to its advantages of being edible, easily degradable, pollution-free, healthy, and low cost. The application of natural red pigment in the dyeing of cellulose fiber fabrics is more friendly to people with sensitive skin (especially infants and young children) and has good market and consumer recognition prospects.

[0006] Cellulose fiber fabrics are one of the most common textiles in daily life and have an important impact on people's health (for example, cellulose fiber fabrics will directly contact the mouth, nose, eyes, etc.). At present, most of the colored cellulose fiber fabrics available on the market are dyed with synthetic dyes, and there are pollution problems in the production, processing, printing and dyeing of synthetic dyes. Therefore, it is of great significance to explore cleaner and more natural methods for dyeing cellulose fiber fabrics. The current patented technology for dyeing fibers using red pigments mainly includes the following contents:

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

[0008] CN108755192A discloses a method for dyeing fabric with natural pigments after color matching. Two or three pigments of natural blue pigment Indigoidine, monascus red pigment and monascus yellow pigment are dissolved in solvents respectively and then mixed for color matching; praseodymium chloride and / or lanthanum trioxide and / or sodium sulfonate are added into water, the pH value is adjusted to 3-6, fabric is added into the dyeing solution, the temperature is raised to 60-90°C for dyeing, and the fabric is dyed after washing and drying.

[0009] CN110698878 A discloses a method for preparing and dyeing a natural red pigment dye for cotton fibers, which comprises the following steps: (1) extracting the dye: using a water-alcohol immersion extraction method, with water-ethanol as solvent, immersing the pigment raw material in the solvent for dye extraction treatment for 6 to 12 hours under a water bath condition of 20 to 40°C, then performing a solid-liquid separation treatment, and taking the upper layer of liquid for evaporation and concentration to obtain a concentrated solution; (2) pigment modification: adding a modifier to the concentrated solution at a mass ratio of 1:1.5, and then adding an alkali agent, allowing the mixed system to react at 0 to 60°C for 8 to 12 hours, and then concentrating and spray drying to obtain a natural red pigment dye for cotton fibers.

[0010] As can be seen from the above patented technology, red yeast rice pigment is currently used for the dyeing of protein fiber and cotton fiber, and it all needs to use mordant as fixing agent, that is, dyeing by metal ion mordant method. As metal ions, the fiber after dyeing cannot achieve health and environmental protection requirements, and the pollution problem of industrial wastewater cannot be avoided, thereby affecting the sustainable development requirements of green environmental protection in the textile printing and dyeing industry. At the same time, due to the low affinity of red yeast rice pigment to cellulose fiber and the poor color yield, it is more necessary to use heavy metal mordant to process, thereby limiting the industrial application of red yeast rice pigment in cellulose fiber dyeing. Therefore, how to realize the dyeing of cellulose fiber using red yeast rice pigment without the participation of metal ions, and make cellulose fiber have excellent dyeing depth, color fastness (such as soap fastness, rubbing fastness), and at the same time, it can also give fiber antibacterial performance while dyeing, realize green environmental protection ecological purpose, become a difficult problem that technicians in the field of textile printing and dyeing need to solve urgently. Summary of the invention

[0011] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a nano-monascus red pigment dye solution and an antibacterial dyeing method for cellulose fiber fabrics, which can use monascus red pigment to dye cellulose fibers without the participation of metal ions, and make the cellulose fibers have excellent dyeing depth and color fastness, and can also give the fibers antibacterial properties during dyeing.

[0012] In order to solve the above technical problems, the technical solution adopted by the present invention is: a nano red pigment dye solution, the preparation method of which comprises 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 prepare a mixed solution;

[0014] (2) heating the mixed solution obtained in step (1) at 70-90° C. for 4-6 min to fully dissolve the chitosan, thereby obtaining a chitosan solution for later use;

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

[0016] (4) Slowly add the chitosan solution obtained in step (2) into the nano-monascus red pigment suspension, mix thoroughly and evenly, and obtain the nano-monascus red pigment dye solution.

[0017] In the above-mentioned nano-monascus red pigment 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-monascus red pigment dye solution, in the step (2), the obtained mixed solution is heated at 80° C. for 5 minutes.

[0019] In the above-mentioned nano-monascus red pigment dye solution, in the step (3), the dosage of the nano-monascus red pigment is 12.5% ​​owf.

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

[0021] The above-mentioned nano-monascus red pigment dye solution, the particle size distribution range of the nano-monascus red pigment used in step (3) is 71-188nm.

[0022] A method for antibacterial dyeing of cellulose fiber fabric comprises the following steps:

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

[0024] (2) placing the cellulose fiber fabric into the nano-monascus red pigment dye solution according to any one of claims 1 to 4, setting the dyeing time to 90-150 min, the dyeing temperature to 80-100° C., and the dyeing bath ratio to 1:40-60;

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

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

[0027] (5) The cleaned cellulose fiber fabric is placed in an oven for drying.

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

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

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

[0031] The advantages of the nano-monascus red pigment dyeing solution and the antibacterial dyeing method of cellulose fiber fabric of the present invention are: the present invention uses the environment-friendly natural pigment dye produced by microbial fermentation, and completely abandons the pollution problem of artificial synthetic dyes in the production and processing and printing and dyeing application process. Chitosan is used as a color fixing agent, and most of the dissolved monascus red pigment molecules and part of the undissolved nano-monascus red pigment particles are fully utilized, not only the firm combination of monascus red pigment and cellulose fiber fabric is achieved, but also excellent dyeing depth and color fastness are achieved, and the cellulose fiber fabric after dyeing has obvious antibacterial performance. The nano-level monascus red pigment used can be well dispersed in the dyeing solution, avoiding the use of organic solvents to dissolve the pigment, ensuring the cleanliness and environmental protection of the dyeing process, and realizing the green ecological printing and dyeing processing of cellulose fiber fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The process flow chart of the preparation of the nano-monascus red pigment dye solution and the antibacterial dyeing process of cellulose fiber fabrics of the present invention;

[0033] Figure 2 This is a real picture of a towel treated by the antibacterial dyeing process of Example 2 of the present invention;

[0034] Figure 3 for Figure 2 An enlarged view of section A of the towel shown;

[0035] Figure 4 This is an optical microscope photo of the towel obtained after the treatment in Example 2;

[0036] Figure 5 This is the particle size distribution diagram of nano-monascus red pigment;

[0037] Figure 6 This is a curve diagram showing the change of the average particle size of nano-monascus red pigment particles before and after heating;

[0038] Figure 7 This is an electron microscope photograph of cellulose fibers in the dyed fabric. DETAILED DESCRIPTION

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

[0040] In the present invention, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the attached drawings; while "inside" and "outside" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order. The term "plurality" means "two or more".

[0041] like Figure 1 As shown, a nano red pigment dye solution, the preparation method comprises 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 prepare a mixed solution;

[0043] (2) heating the mixed solution obtained in step (1) at 70-90° C. for 4-6 min to fully dissolve the chitosan, thereby obtaining a chitosan solution for later use;

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

[0045] (4) Slowly add the chitosan solution obtained in step (2) into the nano-monascus red pigment suspension, mix thoroughly and evenly, and obtain the nano-monascus red pigment dye solution.

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

[0047] The method for antibacterial dyeing of cellulose fiber fabric using the prepared nano monascus red pigment dye solution comprises the following steps:

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

[0049] (2) placing the cellulose fiber fabric into the nano-monascus red pigment dye solution according to any one of claims 1 to 4, setting the dyeing time to 90-150 min, the dyeing temperature to 80-100° C., and the dyeing bath ratio to 1:40-60;

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

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

[0052] (5) The cleaned cellulose fiber fabric is placed in an oven for drying.

[0053] Chitosan is a polysaccharide with a large number of hydroxyl and amino groups in its molecular structure. First, under the high temperature and acidic conditions of dyeing, chitosan macromolecules dissolve in the dye solution, and there are a large number of hydrogen bonds between chitosan macromolecules and cellulose macromolecules in cotton fibers. Secondly, there is a van der Waals force between chitosan molecules and cellulose macromolecules. Since both chitosan and cellulose are macromolecules, the van der Waals force is relatively strong. Third, in the acidic dye solution, chitosan is positively charged and cellulose is negatively charged, and there is an electric charge attraction between chitosan and cotton fibers. Fourth, under high temperature conditions of dyeing, the cellulose macromolecules in cotton fibers undergo violent thermal motion, and the cotton fibers absorb water and swell fully, the pores between cellulose macromolecules in cotton fibers become larger, and the chitosan molecules can partially enter the pores between cellulose macromolecules. After dyeing, the temperature drops to room temperature, the gaps between cellulose macromolecules become smaller, and part of the chitosan macromolecules are sandwiched between the cellulose macromolecules. The combined effects and mechanisms of the above four aspects enable chitosan to be firmly fixed on the cellulose fibers after dyeing, which significantly improves the dyeing effect (dyeing depth) and color fastness of the cellulose fibers.

[0054] The present application is described in detail below through specific embodiments. The following embodiments are only partial embodiments of the present application and are not limitations of the present application.

[0055] Comparative Example 1

[0056] In this comparative example, chitosan and citric acid were not added, and the dye solution was directly prepared using nano-monascus red pigment to dye the cellulose fiber fabric. The specific process is as follows:

[0057] Weigh 12.5% ​​owf of nano-monascus red pigment and add it to deionized water, stir it evenly as dye solution, and dye cellulose fiber fabric at 90℃ for 120min, with a bath ratio of 1:50. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap wash, the soap flake concentration in the soap solution used for soap washing is 2g / L, the soap washing temperature is 70℃, and the time is 10min. After soap washing, wash with warm water first, then rinse the fabric with cold water, and put the fabric into the oven to dry at 70℃.

[0058] Comparative Example 2

[0059] In this comparative example, a chitosan solution without citric acid is prepared in advance, and then a nano-monascus red pigment dye solution is prepared. The specific process is as follows:

[0060] Weigh 10% owf chitosan, add 1 / 5 of the total dye solution of deionized water, and heat at 80℃ for 5min. Weigh 12.5% ​​owf nano-monascus red pigment and add 4 / 5 of the total dye solution of deionized water to obtain a nano-monascus red pigment suspension. Slowly pour the chitosan solution into the nano-monascus red pigment suspension and stir evenly as the dye solution. Dye the cellulose fiber fabric at 90℃ for 120min with a bath ratio of 1:50. After dyeing, rinse the cellulose fiber fabric with warm water first, and then soap wash. The soap flake concentration in the soap solution used for soap washing is 2g / L, the soap washing temperature is 70℃, and the time is 10min. After soap washing, wash with warm water first, then rinse the fabric with cold water, and put the fabric into the oven to dry at a drying temperature of 70℃.

[0061] Example 1

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

[0063] Example 2

[0064] Weigh 10% owf chitosan and 10% owf monohydrate citric acid, add 1 / 5 of the total dye solution to deionized water, and heat at 80°C for 5 minutes to obtain a chitosan solution. Weigh 12.5% ​​owf nano-monascus red pigment and add 4 / 5 of the total dye solution to deionized water to obtain a nano-monascus red pigment suspension. Slowly pour the chitosan solution into the nano-monascus red pigment suspension and stir evenly as the dye solution. Dye the cellulose fiber fabric at 90°C for 120 minutes with a bath ratio of 1:50. After dyeing, rinse the cellulose fiber fabric with warm water first, then soap wash, the soap flake concentration in the soap solution used for soap washing is 2g / L, the soap washing temperature is 70°C, and the time is 10min. After soap washing, wash with warm water first, then rinse the fabric with cold water, and put the fabric into an oven to dry at a drying temperature of 70°C.

[0065] Example 3

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

[0067] The present invention uses the prepared nano-monascus red pigment dye solution to perform antibacterial dyeing on cellulose fiber fabrics, and the cellulose fiber fabrics finally obtained are tested, and the test results are as follows:

[0068] Owf refers to the weight of the fabric, such as 1% owf means that 0.01g of dye or auxiliary agent is used for 1g of fabric.

[0069] The color fastness to rubbing is measured according to GB / T 3920-2008 "Textiles - Tests for Color Fastness - Color Fastness to Rubbing". The color fastness to washing is measured according to GB / T 3921-2008 "Textiles - Tests for Color Fastness - Color Fastness to Washing".

[0070] The antibacterial properties of fabrics are tested according to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method".

[0071] Table 1: Test results of the performance of cellulose fiber fabric dyed with nano-monascus red pigment

[0072]

[0073] Note: The K / S value indicates the color depth of the fabric. The larger the value, the darker the color.

[0074] Color fastness description: The color fastness grades listed in the table range from 1 to 5, with 5 indicating the best color fastness and 1 indicating the worst.

[0075] As shown in Table 1, by comparing "Comparative Examples 1, 2" and "Examples 2, 3", it can be seen that the addition of chitosan and citric acid has a great influence on the dyeing depth (K / S value) of cellulose fiber fabrics. Only after adding chitosan and citric acid at the same time can the cellulose fiber fabrics obtain a better dyeing effect. By comparing "Example 1" and "Examples 2, 3", it can be seen that the amount of citric acid added has a great influence on the dyeing depth (K / S value) of cellulose fiber fabrics. When the amount of citric acid added is small, chitosan is difficult to dissolve and the color of the fabric is very light. Therefore, the amount of citric acid that can make chitosan dissolve better is very critical. Generally speaking, for the same dye dyed fabric, the lighter the color, the higher the color fastness. It can be seen from Table 1 that compared with "Comparative Examples 1, 2, Example 1", the color fastness of the fabric in "Examples 2, 3" with significantly higher color depth has not decreased, indicating that the present technology has achieved a higher color depth while the color fastness has not decreased, verifying the advanced nature of the present technology.

[0076] like Figure 2-4 As shown, the present invention adopts the nano-monascus red pigment dyeing process, which shows an excellent dyeing effect on cellulose fiber fabrics, and the dyeing is uniform and reaches the expected and satisfactory dyeing depth.

[0077] 1. About the dyeing mechanism of the present invention:

[0078] The difference between the present invention and the classical dyeing mechanism of traditional synthetic dyes (i.e., dyes that are all dissolved in the dye solution) is that most of the dissolved Monascus red pigment molecules and some undissolved nano Monascus red pigment particles can be utilized and dyed.

[0079] 1. Dyeing mechanism of dissolved red pigment of Monascus:

[0080] like Figure 5 , 6As shown in the figure, the nano-scale red pigment particles will partially dissolve under the high temperature conditions of dyeing, and the smaller the pigment particles, the larger the specific surface area, the easier it is to dissolve under the high temperature conditions of dyeing, the more pigment molecules in the dissolved state, and the more pigment molecules dyed on the fabric. From the change in the particle size of the nano red pigment before and after heating, it can be seen that the average particle size of the pigment particles changes from 120nm before heating to 40nm after heating. This shows that the nano pigment will partially dissolve during the dyeing process. There are multiple carbonyl groups and ether bonds in the dissolved pigment molecules, which can form multi-site hydrogen bonds with cellulose and chitosan, and there are also van der Waals forces with cellulose and chitosan. In addition, the monascorubramine and rubropunctamine molecules in the red pigment contain imino groups, which can combine with hydrogen ions under acidic conditions of dyeing, and there is charge attraction between them and cotton fibers. In addition, after chitosan is firmly combined with cotton fibers, it forms a film on the fiber surface, which will also prevent the red pigment from falling off, and also play a color fixing role.

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

[0082] like Figure 7 As shown, through electron microscope observation, it can be seen that the undissolved nano pigment particles are coated, adhered, and fixed on the fiber surface by chitosan. Since chitosan is firmly combined with cotton fiber to form a film on the fiber surface, it can not only firmly coat the dissolved red monascus pigment molecules inside and on the surface of the cotton fiber, but also the structure of the film can coat and adhere the undissolved nano pigment particles inside the film and fix them on the fiber surface. The dissolved chitosan plays the role of a coating here, realizing the further dyeing and utilization of the undissolved nano red monascus pigment particles, making up for the low affinity of red monascus pigment to cellulose fiber and the defects of color difference, and improving the dyeing depth and fixation effect.

[0083] 2. Factors affecting dyeing effect

[0084] 1. Pigment dosage: The pigment dosage of the present invention has a great influence on the color depth of the fabric. As is known to all, under the premise of other conditions being the same, a small amount of pigment will result in a light dyeing, while a large amount of pigment will result in a darker color. However, after the present invention reaches the optimal dosage, the color depth of the fabric no longer increases with the increase of the pigment dosage. Therefore, selecting the appropriate pigment dosage can not only achieve excellent dyeing effects, but also reduce production costs to the greatest extent.

[0085] 2. Chitosan dosage: In view of the "dissolved + undissolved" dual-functional color fixing effect of chitosan, the chitosan dosage in the present invention has a significant effect on the color depth of the fabric. Chitosan plays a color fixing role. The greater the chitosan dosage, the better the color fixing effect and the darker the fabric color. However, after reaching the optimal dosage, the fabric color depth no longer increases with the increase of chitosan dosage.

[0086] 3. Dyeing temperature: The dyeing temperature of the present invention has a great influence on the color depth of the fabric. According to the test, the K / S value of the dyed fabric at 90°C is about 3 times that at 70°C. This is because high temperature is conducive to the dissolution of nano-scale red pigment particles of Monascus, and the dissolved pigment molecules dyeing the fabric have a great influence on the color depth of the fabric.

[0087] 4, dyeing time: dyeing time has a great influence on fabric color depth. After testing, the K / S value of dyeing 120 minutes fabric is about 3 times of dyeing 30 minutes fabric. According to the classical dyeing mechanism of synthetic dyes (i.e. all dissolved dyes in the dye liquor), dyeing 30-60 minutes can reach maximum color depth basically. But the present invention needs 120 minutes, is in order to partially dissolve the nano pigment under hot conditions, after the dissolved pigment molecules dye the fabric, the undissolved nano pigment microparticles can further dissolve and continue to dye the fabric, so that the nano monascus red pigment microparticles reach maximum solubility, improves the depth of dyeing.

[0088] In the present invention, regenerated cellulose fiber fabrics such as viscose fabric, lyocell fabric, modal fabric or cuprammonium fabric can be antibacterial dyed by the antibacterial dyeing method. The present invention develops a new method for antibacterial dyeing of cellulose fiber fabrics using nano-monascus red pigment. First, chitosan is heated and dissolved under acidic conditions, and then the prepared chitosan solution is added to the nano-monascus red pigment suspension to prepare the final dye solution. The optimal dyeing method is obtained through dyeing process exploration to achieve the firm dyeing of cellulose fiber fabrics by nano-monascus red pigment. The dyed fabric has good soap resistance and rubbing fastness, and exhibits excellent antibacterial effect on Staphylococcus aureus. The dyes and auxiliaries required in the process include monascus red pigment, chitosan, and citric acid, which are all natural products, green, environmentally friendly and sustainable.

[0089] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A nano red monascus pigment dye solution, characterized in that: The preparation method comprises 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 prepare a mixed solution; (2) heating the mixed solution obtained in step (1) at 70-90° C. for 4-6 min to fully dissolve the chitosan, thereby obtaining a chitosan solution for later use; (3) Take 10-15% owf of nano-monascus red pigment, add 4 / 5 of the total dye solution of deionized water, and stir evenly to prepare a nano-monascus red pigment suspension for later use; (4) Slowly add the chitosan solution obtained in step (2) into the nano-monascus red pigment suspension, mix thoroughly and evenly, and obtain the nano-monascus red pigment dye solution.

2. The nano monascus red pigment dye solution according to claim 1, wherein: In the step (1), the amount of chitosan used is 10% owf, and the amount of organic acid used is 10% owf.

3. Nano monascus red pigment dye solution according to claim 1, is characterized in that: In the step (2), the obtained mixed solution is heated at 80° C. for 5 minutes.

4. Nano monascus red pigment dye solution according to claim 1, is characterized in that: In the step (3), the dosage of the nano-monascus red pigment is 12.5% ​​owf.

5. Nano monascus red pigment dye solution according to claim 1, is characterized in that: In the step (1), the organic acid is citric acid monohydrate or acetic acid.

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

7. A method for antibacterial dyeing of cellulose fiber fabric, characterized in that: The steps include: (1) Prepare cellulose fiber fabric to be dyed for later use; (2) placing the cellulose fiber fabric into the nano-monascus red pigment dye solution according to any one of claims 1 to 4, setting the dyeing time to 90-150 min, the dyeing temperature to 80-100° C., and the dyeing bath ratio to 1:40-60; (3) Take out the cellulose fiber fabric, wash it with deionized water, and then wash it with soap; (4) Clean the soaped cellulose fiber fabric with deionized water; (5) The cleaned cellulose fiber fabric is placed in an oven for drying.

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

50.

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

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

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