Ecological short-process dyeing and fixation integrated treatment method for cotton-polyester blended fabric

Abstract

The invention relates to the field of spinning, and particularly discloses an ecological short-process dyeing and fixation integrated treatment method for a cotton-polyester blended fabric, which comprises the following steps: S1, pretreating the cotton-polyester blended fabric to remove impurities; s2, dye liquor is prepared on the basis of disperse dye and reactive dye, a bio-based color fixing agent is added, a mixed solution is prepared, then the temperature is increased, the pH value is adjusted, the pretreated cotton-polyester blended fabric is soaked in the mixed solution, treatment and temperature increasing are carried out, a nano-porous material is added, and color fixing is carried out for 20-30 min; s3, post-treatment: drying after treatment in the step S2 to finish dyeing and color fixation; wherein the bio-based color fixing agent in the step S2 comprises a natural phenolic compound and a bio-based polymer in a mass ratio of 1: (1-5). The device has the advantages that integrated operation of dyeing and color fixing is achieved, water consumption and energy consumption are reduced, meanwhile, the color fixing fastness is higher, and the device is more environmentally friendly.

Description

Technical Field

[0001] This application relates to the textile field, and more specifically, it relates to an eco-friendly, short-process integrated dyeing and color-fixing treatment method for polyester-cotton blended fabrics. Background Technology

[0002] In the textile dyeing and finishing industry, polyester-cotton blended fabrics are widely used in clothing, home textiles, and other fields due to their combination of abrasion resistance, wrinkle resistance, and moisture absorption and breathability. Traditional dyeing and color fixing processes for polyester-cotton blended fabrics are lengthy and complex, typically involving the following steps: First, pretreatment is performed to remove impurities from the fabric surface. Then, after dyeing, multiple washes are needed to remove floating color and residual auxiliaries. Next, the fabric is immersed in a solution containing a fixing agent for color fixation treatment to improve the binding strength between the dye and the fiber and prevent fading during washing. After color fixation, post-washing and soaping are performed to remove residual fixing agent and unbound dye. The above pretreatment, dyeing, color fixation and post-treatment are carried out separately, requiring multiple washes, which leads to waste of water and energy resources. Moreover, traditional color fixatives have limited effectiveness and are prone to fading after washing, resulting in poor color fixation.

[0003] Based on the above problems, it is necessary to develop new processes that can achieve integrated dyeing and color fixing operations, reduce water and energy consumption, and at the same time achieve higher color fastness and be more environmentally friendly. Summary of the Invention

[0004] In order to achieve integrated dyeing and color fixing operations, reduce water and energy consumption, and achieve higher color fastness and greater environmental friendliness, this application provides an eco-friendly short-process integrated dyeing and color fixing treatment method for polyester-cotton blended fabrics.

[0005] This application provides an eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics, employing the following technical solution: An eco-friendly, short-process integrated dyeing and color-fixing treatment method for polyester-cotton blended fabrics includes the following steps: S1. Pre-treat the polyester-cotton blended fabric to remove impurities; S2. Prepare a dyeing solution based on disperse dyes and reactive dyes, add a bio-based fixing agent to obtain a mixed solution, then heat to 60-65℃, adjust the pH value to 5-5.5, immerse the pretreated polyester-cotton blended fabric in the mixed solution, treat for 30-40 minutes, then heat to 70-75℃, add nanoporous material, maintain the pH value to 6-6.5, and fix the color for 20-30 minutes; S3. Post-treatment: After step S2, drying is performed to complete the dyeing and color fixation. In step S2, the bio-based fixing agent includes a natural phenolic compound and a bio-based polymer in a mass ratio of 1:(1-5). The natural phenolic compound is selected from one or both of tannic acid and gallic acid, and the bio-based polymer is selected from one or both of chitosan and starch derivatives.

[0006] By adopting the above technical solution, this application mixes disperse dyes and reactive dyes and adds a bio-based fixing agent to directly achieve integrated dyeing and fixing. This eliminates the need for separate fixing solution preparation for washing after dyeing, which is required in traditional processes, significantly reducing water and energy consumption. Furthermore, in this application, the first stage is treated at 60-65℃, where disperse dyes are applied to polyester and reactive dyes are initially adsorbed onto cotton fibers. Then, a bio-based fixing agent is added, and the temperature is raised to 60-65℃, causing the polyester fibers to expand further, the disperse dyes to diffuse deeper, and the activity of the active groups on the cotton fibers to be enhanced and react completely with the dyes. At the same time, the addition of nanoporous materials strengthens the fixing process, achieving integrated dyeing and fixing with better fixing rate.

[0007] In this application, the bio-based color-fixing agent is a blend of natural phenols and biopolymers. The hydroxyl groups in the natural phenolic compounds form hydrogen bonds with the fiber surface and dye molecules, enhancing the adhesion between the dye and the fiber. Their hydrophobic benzene ring structure can embed into the amorphous regions of the polyester fiber, reducing dye leaching. The film-forming properties of chitosan and starch derivatives can form a transparent protective film on the fiber surface, encapsulating the dye molecules and preventing them from falling off, thus improving color-fixing rate and durability. Their porous structure can also adsorb unreacted dye, reducing floating dye. Furthermore, the amino groups of chitosan can form hydrogen and covalent bonds with the hydroxyl groups of cotton fibers, further fixing the dye. Starch derivatives enhance the affinity with the fiber. Through a dual mechanism of "chemical bonding + physical encapsulation," the natural phenols and biopolymers significantly improve color-fixing efficiency, washing fastness, and rubbing fastness. Moreover, compared to traditional polyamine compounds, the raw materials of this color-fixing agent are more environmentally friendly and have better biodegradability.

[0008] In this application, nanoporous materials are added during the color-fixing stage. On the one hand, their specific surface area is used to adsorb dye molecules, reduce the concentration of free dye in the solution, and promote the dyeing equilibrium to move into the fiber. On the other hand, the silanol groups on the surface of the nanoporous materials can interact with the polar groups of dye molecules through hydrogen bonding and other interactions, thereby enhancing the fixation of dye on the fiber surface. This further promotes the adsorption of dye on the fabric and improves the color-fixing rate.

[0009] Optionally, the drying in step S3 may be microwave drying or plasma treatment.

[0010] Optionally, in step S2, the temperature is raised to 60-65℃, the pH value is adjusted to 5.5, and after adding the nanoporous material, the pH value is maintained at 6.

[0011] By adopting the above technical solution, the weakly acidic pH environment during the dyeing stage can simultaneously meet the dyeing requirements of both polyester and cotton fibers that require weak acid activation. This avoids the complex operation of adjusting the pH step by step during the dyeing and fixing processes in traditional processes. Furthermore, the addition of nanoporous materials can neutralize some of the negative charge on the surface of the nanoporous materials, reduce the repulsion between the dye molecules and the settling point, and improve the adsorption efficiency.

[0012] Optionally, the specific operation of step S2 is as follows: prepare a dyeing solution based on disperse dye and reactive dye, add a bio-based fixing agent to obtain a mixed solution, then heat to 60°C, adjust the pH value to 5.5, immerse the pretreated polyester-cotton blended fabric in the mixed solution, treat for 30 minutes, heat to 70°C, add nanoporous material, maintain the pH value to 6, and fix the color for 20 minutes.

[0013] By adopting the above technical solution, the above dyeing adopts low-temperature dyeing, combined with the auxiliary effect of bio-based fixing agent, to achieve low-temperature and high-efficiency dyeing, reduce energy consumption, and the disperse dye and reactive dye are applied in steps. First, under the condition of 60°C, the glass transition temperature of the polyester fiber increases, the molecular chain segment movement intensifies, and the fiber gaps widen. The disperse dye enters the fiber interior through hydrophobic interaction and van der Waals forces, forming a monolayer adsorption. Under the weakly acidic condition of pH 5, the active groups of the reactive dye activate the hydroxyl groups of the cotton fiber and covalently bond with the dye molecules to form stable chemical bonds.

[0014] Optionally, the nanoporous material may be selected from one or both of nano-silica and nano-clay.

[0015] Optionally, the amount of nanoporous material added is 0.1-3 wt% of the amount of bio-based color-fixing agent added.

[0016] Optionally, in step S2, the ratio of the dye liquor to the pretreated polyester-cotton blended fabric is 1:(8-10), and the amount of bio-based fixing agent added is 2-4 wt% of the sum of disperse dye and reactive dye.

[0017] Optionally, in step S2, the mass ratio of disperse dye to reactive dye is (1.5-2.5):1, and the mass percentage of reactive dye in the dye solution is 1-3 wt%.

[0018] By adopting the above technical solution, the control of the amount of dye added results in more uniform and stable dyeing, and a better dyeing effect.

[0019] Optionally, the bio-based fixing agent in step S2 includes a natural phenolic compound and a bio-based polymer in a mass ratio of 1:(2-3), wherein the natural phenolic compound is a mixture of tannic acid and gallic acid in a mass ratio of 1:(0.8-1), and the bio-based polymer is a mixture of chitosan and carboxymethyl starch in a mass ratio of (1.8-2):1.

[0020] Optionally, tannic acid can be modified with glycidyltrimethylammonium chloride to obtain cationic tannic acid, which is then added.

[0021] By adopting the above technical solution, tannic acid is modified by glycidyltrimethylammonium chloride to achieve quaternization modification of tannic acid, thereby obtaining cationic tannic acid. This enhances its electrostatic binding ability with anionic reactive dyes, significantly reduces the water solubility of the dyes, and improves its affinity for polyester. When combined with gallic acid, it forms a dual-active-site fixing agent, which improves the adsorption capacity and fixing effect of reactive dyes.

[0022] Optionally, chitosan may be added after being modified with epichlorohydrin and ethylenediamine.

[0023] By adopting the above technical solution, chitosan is modified with epichlorohydrin and ethylenediamine. Epichlorohydrin crosslinks with the hydroxyl and amino groups in the chitosan molecular chain through a ring-opening reaction to form a three-dimensional network structure. The introduction of functional groups such as epoxy and hydroxyl groups can form covalent bonds or hydrogen bonds with dye molecules and fibers, significantly reducing the water solubility of dyes and improving wash fastness. Moreover, the modified chitosan molecular chain has an increased openness and a larger specific surface area, which further reacts with ethylenediamine to introduce more amino adsorption sites. The significant improvement in its adsorption capacity reduces the shedding of dye molecules by physically encapsulating them in the color-fixing process. Furthermore, the amino groups combine with dye molecules through hydrogen bonds and other mechanisms to enhance the color-fixing strength and improve the color-fixing effect.

[0024] Furthermore, unmodified chitosan is easily soluble under acidic or alkaline conditions. However, the insoluble network structure formed after epichlorohydrin modification ensures its stability in weakly acidic conditions, preventing performance degradation due to pH fluctuations during the fixation process. Simultaneously, the cross-linked structure enhances the binding force between the fiber and the dye, reducing dye migration during washing and improving the fixation effect. Carboxymethyl starch, as an anionic polymer, can form ionic bonds with cationic tannic acid, constructing a three-dimensional cross-linked network that encapsulates the dye. Simultaneously, carboxymethyl fibers form a film on the fiber surface, creating a physical barrier and reducing dye shedding. Finally, the ionic bonding between cationic tannic acid and carboxymethyl starch, the cross-linking film formation of chitosan, and the coordination effect of natural phenols form a dual "chemical-physical" fixation mechanism, significantly improving the fixation rate. Cationicization is optional; cationic tannic acid is prepared through the following steps: A tannic acid solution is prepared by mixing tannic acid and sodium hydroxide and dissolving them in water. The tannic acid solution was heated to 45-55℃, pyridine was added, and then an aqueous solution of glycidyltrimethylammonium chloride was added dropwise. The mixture was stirred for 8-10 hours and cooled to room temperature. The molecular weight cutoff was 400-600 Da by dialyzing. The retentate was concentrated under vacuum to 1 / 3-1 / 2 of its original volume. After pre-freezing at -25-(-15)℃ for 20-25 hours, the mixture was freeze-dried to obtain cationic tannic acid.

[0025] By adopting the above technical solution, tannic acid is first deprotonated under alkaline conditions to generate phenoxy anions, which enhance nucleophilicity and provide active sites for quaternization reactions. Epioxypropyltrimethylammonium chloride, as a quaternary ammonium salt compound containing an epoxy group, has an epoxy ring that is easily opened by nucleophilic attack. At the same time, the trimethylammonium group in the molecule imparts cationicity. Pyridine is added to the tannic acid solution as a catalyst. Its alkaline environment promotes the deprotonation of phenolic hydroxyl groups. Moreover, the aromatic ring of pyridine stabilizes the intermediate through π-π interactions. The phenoxy anions attack the epoxy ring of epioxypropyltrimethylammonium chloride, causing the epoxy ring to open and form ether bonds. At the same time, quaternary ammonium groups are introduced into the tannic acid molecule to generate cationic tannic acid containing a quaternary ammonium structure.

[0026] Optionally, when preparing cationic tannic acid, the mass ratio of tannic acid to sodium hydroxide is 1:(0.2-0.3), and the amount of water added is 8-10 times the mass of tannic acid. The molar ratio of tannic acid to pyridine is 1:(20-25), and the molar ratio of tannic acid to glycidyltrimethylammonium chloride is 1:(1-1.5).

[0027] Optionally, the chitosan modification process includes the following steps: Chitosan powder was dissolved in water, sodium hydroxide was added, the temperature was raised to 50-55℃, and the mixture was stirred for 30-40 minutes. Epichlorohydrin was then added dropwise, and the temperature was maintained for 3-4 hours. After the reaction was completed, the mixture was cooled to room temperature, ethylenediamine was added, the temperature was raised to 60-65℃, and the reaction was carried out for 2-3 hours. After the reaction was completed, hydrochloric acid was added to adjust the pH to neutral. After centrifugation, the supernatant was discarded, ethanol was added to precipitate the mixture, and the precipitate was dispersed in water. The molecular weight cutoff was 1000 Da by dialyzing, and then the mixture was concentrated under vacuum and freeze-dried to obtain modified chitosan.

[0028] By adopting the above technical solution, chitosan is first swollen under alkaline conditions, and then epichlorohydrin is added. The epoxy groups of epichlorohydrin open under alkaline conditions to form an intermediate that reacts with the amino and hydroxyl groups on the chitosan molecular chain to form a cross-linked structure between the chitosan molecular chains. Then, after adding ethylenediamine, its amino groups can react with the remaining epoxy groups in the epichlorohydrin cross-linked product to further introduce amino groups. Finally, the network structure fixes the dye through physical adsorption and the reaction of dye with the amino or hydroxyl groups on chitosan, thus reducing dye migration during washing.

[0029] Optionally, during chitosan modification, chitosan powder is dissolved in 6-8 times its mass of water, sodium hydroxide is added to adjust the pH to 9-10, the mass ratio of epichlorohydrin to chitosan is (3-4):1, and the mass ratio of ethylenediamine to chitosan is (2-3):1.

[0030] In summary, this application has the following beneficial effects: 1. In this application, disperse dyes and reactive dyes are mixed and then a bio-based fixing agent is added to directly achieve integrated dyeing and fixing. This eliminates the need for separate fixing solution preparation for washing after dyeing, which is required in traditional processes. This significantly reduces water and energy consumption. In addition, in this application, the first stage is treated at 60-65℃, where disperse dyes are applied to polyester and reactive dyes are initially adsorbed onto cotton fibers. Then, a bio-based fixing agent is added, and the temperature is raised to 60-65℃. The polyester fibers expand further, the disperse dyes diffuse deeper, and the activity of the active groups on the cotton fibers is enhanced, allowing for a complete reaction with the dyes. At the same time, the addition of nanoporous materials strengthens the fixing process, achieving integrated dyeing and fixing with better fixing rate. 2. The bio-based color-fixing agent in this application is a blend of natural phenols and biopolymers. The hydroxyl groups in the natural phenolic compounds form hydrogen bonds with the fiber surface and dye molecules, enhancing the adhesion between the dye and the fiber. Their hydrophobic benzene ring structure can embed into the amorphous regions of the polyester fiber, reducing dye leaching. The film-forming properties of chitosan and starch derivatives can form a transparent protective film on the fiber surface, encapsulating dye molecules and preventing them from falling off, thus improving color-fixing rate and durability. Their porous structure can also adsorb unreacted dye, reducing floating dye. Furthermore, the amino groups of chitosan can form hydrogen and covalent bonds with the hydroxyl groups of cotton fibers, further fixing the dye. Starch derivatives enhance the affinity with the fiber. Through a dual mechanism of "chemical bonding + physical encapsulation," natural phenols and biopolymers significantly improve color-fixing efficiency, washing fastness, and rubbing fastness. Moreover, compared to traditional polyamine compounds, the raw materials of the aforementioned color-fixing agent are more environmentally friendly and have better biodegradability. 3. In this application, nanoporous materials are added during the color-fixing stage. On the one hand, their specific surface area is used to adsorb dye molecules, reduce the concentration of free dye in the solution, and promote the dyeing equilibrium to move into the fiber. On the other hand, the silanol groups on the surface of the nanoporous materials can interact with the polar groups of dye molecules through hydrogen bonding and other interactions, thereby enhancing the fixation of dye on the fiber surface. This further promotes the adsorption of dye on the fabric and improves the color-fixing rate. Detailed Implementation

[0031] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0032] Unless otherwise specified, all percentages in the following examples are mass percentages.

[0033] In the following embodiments, the polyester-cotton blended fabric is selected as a 70 / 30 polyester-cotton blended fabric, that is, a fabric made of 70% polyester and 30% cotton blend. Disperse yellow ACE dye was selected as the disperse dye, and reactive yellow EMF dye was selected as the reactive dye.

[0034] Example 1 An eco-friendly, short-process integrated dyeing and color-fixing treatment method for polyester-cotton blended fabrics includes the following steps: S1. Pretreatment: Immerse the polyester-cotton blended fabric in warm water at 40°C for 10 minutes. S2, Integrated dyeing and color fixing treatment: Preparation of dye liquor: First, add disperse dye and reactive dye to water and prepare the dye liquor according to a liquor ratio of 1:9 (that is, the mass ratio of polyester-cotton blended fabric to dye liquor). The mass ratio of disperse dye to reactive dye is 2:1, and the mass percentage of reactive dye in the dye liquor is 2wt%. Then, a bio-based fixing agent was added to the prepared dye solution to obtain a mixed solution. The amount of bio-based fixing agent added was 3 wt% of the sum of disperse dye and reactive dye. The bio-based fixing agent included natural phenolic compounds and bio-based polymers in a mass ratio of 1:3. The natural phenolic compounds were selected as a mixture of tannic acid and gallic acid in a mass ratio of 1:0.9, and the bio-based polymers were selected as a mixture of chitosan and carboxymethyl starch in a mass ratio of 1.9:1. After the mixture is prepared, the temperature is first raised to 60°C and the pH value is adjusted to 5.5. The pretreated polyester-cotton blended fabric is then immersed in the mixture for 30 minutes. After that, the temperature is raised to 70°C and nano silica is added. The amount of nano silica added is 1.5 wt% of the amount of bio-based color-fixing agent added. The pH value is maintained at 6 and the color is fixed for 20 minutes. S3. Post-treatment: The polyester-cotton blended fabric treated in step S2 is dried using microwave at a temperature of 80°C for 5 minutes to complete the dyeing and color fixing of the polyester-cotton blended fabric.

[0035] Example 2 An eco-friendly, short-process integrated dyeing and color-fixing treatment method for polyester-cotton blended fabrics includes the following steps: S1. Pretreatment: Immerse the polyester-cotton blended fabric in warm water at 40°C for 10 minutes. S2, Integrated dyeing and color fixing treatment: Preparation of dye liquor: First, add disperse dye and reactive dye to water and prepare the dye liquor according to a liquor ratio of 1:8 (that is, the mass ratio of polyester-cotton blended fabric to dye liquor). The mass ratio of disperse dye to reactive dye is 1.5:1, and the mass percentage of reactive dye in the dye liquor is 1wt%. Then, a bio-based fixing agent is added to the prepared dye solution to obtain a mixed solution. The amount of bio-based fixing agent added is 2 wt% of the sum of disperse dye and reactive dye. The bio-based fixing agent includes natural phenolic compounds and bio-based polymers in a mass ratio of 1:1. The natural phenolic compounds are selected from a mixture of tannic acid and gallic acid in a mass ratio of 1:0.8, and the bio-based polymers are selected from a mixture of chitosan and carboxymethyl starch in a mass ratio of 1.8:1. After the mixture is prepared, the temperature is first raised to 60°C and the pH value is adjusted to 5. The pretreated polyester-cotton blended fabric is then immersed in the mixture for 30 minutes. After treatment, the temperature is raised to 70°C and nano silica is added. The amount of nano silica added is 0.1 wt% of the amount of bio-based color-fixing agent added. The pH value is maintained at 6 and the color is fixed for 20 minutes. S3. Post-treatment: The polyester-cotton blended fabric treated in step S2 is dried using microwave at a temperature of 80°C for 5 minutes to complete the dyeing and color fixing of the polyester-cotton blended fabric.

[0036] Example 3 An eco-friendly, short-process integrated dyeing and color-fixing treatment method for polyester-cotton blended fabrics includes the following steps: S1. Pretreatment: Immerse the polyester-cotton blended fabric in warm water at 40°C for 10 minutes. S2, Integrated dyeing and color fixing treatment: Preparation of dye liquor: First, add disperse dye and reactive dye to water and prepare the dye liquor according to a liquor ratio of 1:10 (that is, the mass ratio of polyester-cotton blended fabric to dye liquor). The mass ratio of disperse dye to reactive dye is 2.5:1, and the mass percentage of reactive dye in the dye liquor is 3wt%. Then, a bio-based fixing agent is added to the prepared dye solution to obtain a mixed solution. The amount of bio-based fixing agent added is 4 wt% of the sum of disperse dye and reactive dye. The bio-based fixing agent includes natural phenolic compounds and bio-based polymers in a mass ratio of 1:5. The natural phenolic compounds are selected from a mixture of tannic acid and gallic acid in a mass ratio of 1:1, and the bio-based polymers are selected from a mixture of chitosan and carboxymethyl starch in a mass ratio of 2:1. After the mixture is prepared, the temperature is first raised to 65°C and the pH value is adjusted to 5.5. The pretreated polyester-cotton blended fabric is then immersed in the mixture for 40 minutes. After that, the temperature is raised to 75°C and nano silica is added. The amount of nano silica added is 3 wt% of the amount of bio-based color-fixing agent added. The pH value is maintained at 6.5 and the color is fixed for 30 minutes. S3. Post-treatment: The polyester-cotton blended fabric treated in step S2 is dried using microwave at a temperature of 80°C for 5 minutes to complete the dyeing and color fixing of the polyester-cotton blended fabric.

[0037] Example 4 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is disclosed. The method described in Example 1 is followed, except that the bio-based color-fixing agent in step S2 comprises a natural phenolic compound and a bio-based polymer in a mass ratio of 1:3. Furthermore, in this example, the ratio of tannic acid to gallic acid in the natural phenolic compound remains unchanged; however, the tannic acid is modified with glycidyltrimethylammonium chloride to obtain cationic tannic acid before being added. The specific operation is as follows: Take the same amount of tannic acid as in Example 1 for later use, mix tannic acid and sodium hydroxide at a mass ratio of 1:0.2 and dissolve them in water. The amount of water added is 9 times the mass of tannic acid to prepare a tannic acid solution. The tannic acid solution was heated to 50°C, pyridine was added, and then an aqueous solution of glycidyltrimethylammonium chloride was added dropwise. The molar ratio of tannic acid to pyridine was 1:22, and the molar ratio of tannic acid to glycidyltrimethylammonium chloride was 1:1.2. The mixture was stirred for 9 hours, cooled to room temperature, and the molecular weight cutoff was 400-600 Da by dialysis. The retentate was concentrated under vacuum to half its original volume, pre-frozen at -20°C for 22 hours, and then freeze-dried to obtain cationic tannic acid.

[0038] Example 5 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is disclosed. The method described in Example 1 is followed, except that the bio-based color-fixing agent in step S2 comprises a natural phenolic compound and a bio-based polymer in a mass ratio of 1:2. Furthermore, in this example, the ratio of tannic acid to gallic acid in the natural phenolic compound remains unchanged; however, the tannic acid is modified with glycidyltrimethylammonium chloride to obtain cationic tannic acid before being added. The specific operation is as follows: Take the same amount of tannic acid as in Example 1 for later use, mix tannic acid and sodium hydroxide at a mass ratio of 1:0.2 and dissolve them in water. The amount of water added is 8 times the mass of tannic acid to prepare a tannic acid solution. Tannic acid solution was heated to 45°C, pyridine was added, and then an aqueous solution of glycidyltrimethylammonium chloride was added dropwise. The molar ratio of tannic acid to pyridine was 1:20, and the molar ratio of tannic acid to glycidyltrimethylammonium chloride was 1:1. The reaction was stirred for 8 hours, cooled to room temperature, and the molecular weight cutoff was 400-600 Da by dialysis. The retentate was concentrated under vacuum to 1 / 3 of its original volume, pre-frozen at -25°C for 25 hours, and then freeze-dried to obtain cationic tannic acid.

[0039] Example 6 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is disclosed. The method described in Example 1 differs in that the bio-based color-fixing agent in step S2 comprises a natural phenolic compound and a bio-based polymer in a mass ratio of 1:2.5. Furthermore, in this example, the ratio of tannic acid to gallic acid in the natural phenolic compound remains unchanged; however, the tannic acid is modified with glycidyltrimethylammonium chloride to obtain cationic tannic acid before being added. The specific operation is as follows: Take the same amount of tannic acid as in Example 1 for later use. Mix tannic acid and sodium hydroxide at a mass ratio of 1:0.3 and dissolve them in water. The amount of water added is 10 times the mass of tannic acid to prepare a tannic acid solution. Heat the tannic acid solution to 55°C, add pyridine, and then add an aqueous solution of glycidyltrimethylammonium chloride dropwise. The molar ratio of tannic acid to pyridine is 1:25, and the molar ratio of tannic acid to glycidyltrimethylammonium chloride is 1:1.5. Stir the reaction for 10 hours, cool to room temperature, dialyze to a molecular weight cutoff of 400-600 Da, concentrate the retentate under vacuum to 1 / 2 of the original volume, pre-freeze at -15°C for 20 hours, and then freeze-dry to obtain cationic tannic acid.

[0040] Example 7 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is provided, following the method in Example 4. The difference lies in that the ratio of chitosan to carboxymethyl starch in this example is the same as in Example 4, but the chitosan in this example is added after modification. The specific steps of the chitosan modification process include: Take the same amount of chitosan powder as in Example 4 and dissolve it in 7 times its mass of water. Add sodium hydroxide to adjust the pH to 9.5, heat to 50°C, stir for 35 min, then add epichlorohydrin dropwise at a mass ratio of 3.5:1. Maintain the temperature and react for 3.5 h. After the reaction is complete, cool to room temperature, add ethylenediamine at a mass ratio of 2.5:1, heat to 60°C, and react for 2.5 h. After the reaction is complete, add hydrochloric acid to adjust the pH to neutral. After centrifugation, discard the supernatant, add ethanol to precipitate, then disperse the precipitate in water, dialyze to remove a molecular weight cutoff of 1000 Da, then concentrate under vacuum and freeze dry to obtain modified chitosan. Mix the modified chitosan with carboxymethyl starch and add it.

[0041] Example 8 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is provided, following the method in Example 4. The difference lies in that the ratio of chitosan to carboxymethyl starch in this example is the same as in Example 4, but the chitosan in this example is added after modification. The specific steps of the chitosan modification process include: Take the same amount of chitosan powder as in Example 4 and dissolve it in 6 times the mass of water. Add sodium hydroxide to adjust the pH to 9, heat to 50°C, stir for 40 min, and then add epichlorohydrin dropwise. The mass ratio of epichlorohydrin to chitosan is 3:1. Maintain the temperature and react for 3 h. After the reaction is complete, cool to room temperature, add ethylenediamine. The mass ratio of ethylenediamine to chitosan is 2:1. Heat to 60°C and react for 3 h. After the reaction is complete, add hydrochloric acid to adjust the pH to neutral. After centrifugation, discard the supernatant, add ethanol to precipitate, and then disperse the precipitate in water. Dialyze to retain a molecular weight cutoff of 1000 Da, then concentrate under vacuum and freeze dry to obtain modified chitosan. Mix the modified chitosan with carboxymethyl starch and add it.

[0042] Example 9 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is provided, following the method in Example 4. The difference lies in that the ratio of chitosan to carboxymethyl starch in this example is the same as in Example 4, but the chitosan in this example is added after modification. The specific steps of the chitosan modification process include: Take the same amount of chitosan powder as in Example 4 and dissolve it in 8 times its mass of water. Add sodium hydroxide to adjust the pH to 10, heat to 55°C, stir for 30 min, and then add epichlorohydrin dropwise. The mass ratio of epichlorohydrin to chitosan is 4:1. Maintain the temperature and react for 4 h. After the reaction is complete, cool to room temperature and add ethylenediamine. The mass ratio of ethylenediamine to chitosan is 3:1. Heat to 65°C and react for 2 h. After the reaction is complete, add hydrochloric acid to adjust the pH to neutral. After centrifugation, discard the supernatant, add ethanol to precipitate, and then disperse the precipitate in water. Dialyze to remove a molecular weight cutoff of 1000 Da, then concentrate under vacuum and freeze dry to obtain modified chitosan. Mix the modified chitosan with carboxymethyl starch and add it.

[0043] Comparative Example 1 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is carried out according to the method in Example 1, except that tannic acid is selected as the bio-based color-fixing agent.

[0044] Comparative Example 2 An eco-friendly, short-process integrated dyeing and color-fixing method for polyester-cotton blended fabrics is carried out according to the method in Example 1, except that chitosan is selected as the bio-based color-fixing agent.

[0045] Comparative Example 3 An eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics is carried out according to the method in Example 1, except that the bio-based color-fixing agent is a mixture of tannic acid and gallic acid with a mass ratio of 1:0.9.

[0046] Comparative Example 4 An eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics is carried out according to the method in Example 1, except that the bio-based color-fixing agent is a mixture of chitosan and carboxymethyl starch with a mass ratio of 1.9:1.

[0047] Comparative Example 5 An eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics is carried out according to the method in Example 1, except that nano-silica is not added in step S2.

[0048] Performance testing The fabrics obtained after treatment using the methods described in the above examples and comparative examples were tested for color fastness, washing fastness, and rubbing fastness. The color fastness test method was as follows: the polyester-cotton blended fabrics treated using the methods in the examples and comparative examples were boiled in DMSO at 100℃ for 30 minutes at a liquor ratio of 1:300 (mass ratio). This was repeated twice, and the residual liquors were combined. The absorbance of the residual liquor was measured using a UV spectrophotometer, and the color fastness was calculated as follows: Color fastness = 1 - (absorbance of the stripping solution - absorbance of the blank group) ÷ absorbance of the blank group × 100%. The blank group refers to the polyester-cotton blended fabrics not treated in step S1. The statistical results are shown in Table 1 below. Additionally, the washing fastness of dyed fabrics was tested according to GB / T3921—2008 "Textiles - Tests for Color Fastness - Washing Fastness"; the rubbing fastness of dyed fabrics was tested according to GB / T3920—2008 "Textiles - Tests for Color Fastness - Rubbing Fastness". The results are shown in Table 1.

[0049] Table 1: Continued from Table 1: Based on the test data in Table 1 above, the color fixation rate of the fabric after color fixation in the embodiments of this application is high. The eco-friendly short-process dyeing and color fixation integrated treatment method of this application is significantly effective, and its color fastness to washing and rubbing is generally high. The dyed fabric is not easy to fade under washing or dry and wet rubbing conditions. Combining the test results of Examples 1 and Examples 4-6, when tannic acid modified by quaternization to obtain cationic tannic acid is added to the bio-based color fixation, its color fixation rate is further improved, and its color fastness is also significantly improved. Combining the test results of Examples 7-9, the color fixation rate of chitosan is further improved after epoxidation and diethylamine modification. The introduction of its epoxy and amino groups helps to achieve better physical encapsulation and chemical bonding between fibers and dyes, further improving the color fixation rate.

[0050] Combining the test results of Example 1 with those of Comparative Examples 1 and 2, the color-fixing effect is limited when using a single tannic acid or chitosan as the bio-based color-fixing agent. Combining the test results of Comparative Examples 3 and 4, the color-fixing effect is improved compared to Comparative Examples 1 and 2 when using a mixture of polyphenols or a mixture of chitosan and starch as the bio-based color-fixing agent, but it is still far weaker than the mixture of polyphenols, chitosan and starch in Example 1. Combining the test results of Comparative Example 5, the color-fixing effect is also significantly reduced compared to Example 1 when no nano-silica is added during color fixing.

[0051] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An eco-friendly, short-process integrated dyeing and color-fixing treatment method for polyester-cotton blended fabrics, characterized in that... Includes the following steps: S1. Pre-treat the polyester-cotton blended fabric to remove impurities; S2. Prepare a dyeing solution based on disperse dyes and reactive dyes, add a bio-based fixing agent to obtain a mixed solution, then heat to 60-65℃, adjust the pH value to 5-5.5, immerse the pretreated polyester-cotton blended fabric in the mixed solution, treat for 30-40 minutes, then heat to 70-75℃, add nanoporous material, maintain the pH value to 6-6.5, and fix the color for 20-30 minutes; S3. Post-treatment: After step S2, drying is performed to complete the dyeing and color fixation. In step S2, the bio-based fixing agent includes a natural phenolic compound and a bio-based polymer in a mass ratio of 1:(1-5). The natural phenolic compound is selected from one or both of tannic acid and gallic acid, and the bio-based polymer is selected from one or both of chitosan and starch derivatives.

2. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 1, characterized in that: The specific operation of step S2 is as follows: prepare a dyeing solution based on disperse dyes and reactive dyes, add a bio-based fixing agent to obtain a mixed solution, then heat it to 60°C, adjust the pH value to 5.5, immerse the pretreated polyester-cotton blended fabric in the mixed solution, treat for 30 minutes, heat it to 70°C, add nanoporous materials, maintain the pH value to 6, and fix the color for 20 minutes.

3. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 1, characterized in that: The nanoporous material is made of one or both of nano-silica and nano-clay; And / or, the amount of nanoporous material added is 0.1-3 wt% of the amount of bio-based fixing agent added.

4. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 1, characterized in that: In step S2, the ratio of the dye liquor to the pretreated polyester-cotton blended fabric is 1:(8-10), and the amount of bio-based fixing agent added is 2-4 wt% of the sum of disperse dye and reactive dye. And / or, in step S2, the mass ratio of disperse dye to reactive dye is (1.5-2.5):1, and the mass percentage of reactive dye in the dye solution is 1-3wt%.

5. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 1, characterized in that: The bio-based fixing agent in step S2 includes a natural phenolic compound and a bio-based polymer in a mass ratio of 1:(2-3). The natural phenolic compound is a mixture of tannic acid and gallic acid in a mass ratio of 1:(0.8-1), and the bio-based polymer is a mixture of chitosan and carboxymethyl starch in a mass ratio of (1.8-2):

1.

6. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 5, characterized in that: In step S2, tannic acid is modified with glycidyltrimethylammonium chloride to obtain cationic tannic acid, which is then added. And / or, chitosan is added after being modified with epichlorohydrin and ethylenediamine.

7. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 6, characterized in that: Cationic tannic acid is prepared by the following steps: A tannic acid solution is prepared by mixing tannic acid and sodium hydroxide and dissolving them in water. The tannic acid solution was heated to 45-55℃, pyridine was added, and then an aqueous solution of glycidyltrimethylammonium chloride was added dropwise. The mixture was stirred for 8-10 hours and cooled to room temperature. The molecular weight cutoff was 400-600 Da by dialysis. The retentate was concentrated under vacuum to 1 / 3-1 / 2 of its original volume. After pre-freezing at -25-(-15)℃ for 20-25 hours, the mixture was freeze-dried to obtain cationic tannic acid.

8. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 7, characterized in that: When preparing cationic tannic acid, the mass ratio of tannic acid to sodium hydroxide is 1:(0.2-0.3), and the amount of water added is 8-10 times the mass of tannic acid. The molar ratio of tannic acid to pyridine is 1:(20-25), and the molar ratio of tannic acid to glycidyltrimethylammonium chloride is 1:(1-1.5).

9. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 6, characterized in that: The specific steps of chitosan modification include: Chitosan powder was dissolved in water, sodium hydroxide was added, the temperature was raised to 50-55℃, and the mixture was stirred for 30-40 minutes. Epichlorohydrin was then added dropwise, and the temperature was maintained for 3-4 hours. After the reaction was completed, the mixture was cooled to room temperature, ethylenediamine was added, the temperature was raised to 60-65℃, and the reaction was carried out for 2-3 hours. After the reaction was completed, hydrochloric acid was added to adjust the pH to neutral. After centrifugation, the supernatant was discarded, ethanol was added to precipitate the mixture, and the precipitate was dispersed in water. The molecular weight cutoff was 1000 Da by dialyzing, and then the mixture was concentrated under vacuum and freeze-dried to obtain modified chitosan.

10. The eco-friendly short-process dyeing and color-fixing integrated treatment method for polyester-cotton blended fabrics according to claim 9, characterized in that: During the chitosan modification process, chitosan powder is dissolved in 6-8 times its mass of water, sodium hydroxide is added to adjust the pH to 9-10, the mass ratio of epichlorohydrin to chitosan is (3-4):1, and the mass ratio of ethylenediamine to chitosan is (2-3):1.

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