A green printing and dyeing process for cotton fabric surface

Abstract

The present application relates to the field of textiles, and specifically discloses a green printing and dyeing process for the surface of cotton fabrics, comprising the following steps: pre-treating the cotton fabric to remove surface impurities to obtain a pre-treated substrate; first immersing the pre-treated substrate in a pre-dyeing solution containing a natural colorant, and drying to obtain a pre-dyed substrate; coating the pre-dyed substrate with a modifier to form an intermediate layer, and washing with a phosphate buffer to obtain a modified substrate, wherein the modifier is mainly prepared from an amine modifier, a microcapsule anionic dye, cotton fiber, epoxy resin, nano-silica and an amine curing agent; supplementing the pre-dyeing solution after the pre-dyeing treatment with a natural colorant, and adding a microcapsule anionic dye to form a dyeing solution, and then immersing the modified substrate in the dyeing solution for dyeing, and then curing after drying, washing with water, and air-drying to obtain a dyed fabric. The present application has the characteristics of improving the dye fixation rate and making the treatment process more environmentally friendly and green.

Description

Technical Field

[0001] The present application relates to the field of textiles, and more specifically, to a green printing and dyeing process for the surface of cotton fabrics. Background Art

[0002] For a long time, the printing and dyeing industry has mainly used reactive dyes for dyeing. This dyeing method can meet the market demand for color to a certain extent, but it also has many disadvantages.

[0003] First of all, adding inorganic salts to promote dyeing is an important part of traditional reactive dyeing. However, the amount of inorganic salts used is extremely large, which not only wastes resources but also increases production costs. At the same time, a large amount of inorganic salts will be discharged with wastewater during the dyeing process, causing serious pollution to the environment. In addition, high water consumption is also a major problem of traditional dyeing technology. A large amount of water is needed to rinse and dilute the dye during the dyeing process, which not only wastes precious water resources, but also increases the difficulty of wastewater treatment.

[0004] Secondly, the low dye fixation rate is also a problem in traditional dyeing process. Due to the low dye fixation rate, the utilization rate of dye is not high, and a large amount of dye remains in the wastewater, which further increases the color of the wastewater and the difficulty of treatment. Moreover, the low dye fixation rate will also affect the quality of dyed products, making the color not bright and uniform enough, and the color fastness is difficult to reach a high standard.

[0005] In view of the above-mentioned drawbacks, it is urgent to study and improve the printing and dyeing technology of cotton fabrics. The greening and environmental protection of printing and dyeing technology has become the key to the development of the industry. Improving the dye fixation rate is of great significance. On the one hand, it improves the utilization rate of dyes, reduces the residual dyes in wastewater, reduces the chromaticity of wastewater and the difficulty of treatment. At the same time, the high fixation rate also ensures the quality of dyed products, making the colors more vivid and uniform, and the color fastness is better. Summary of the invention

[0006] In order to improve the dye fixation rate and make the treatment process more environmentally friendly and green, the present application provides a green printing and dyeing process for the surface of cotton fabrics.

[0007] The present application provides a green printing and dyeing process for the surface of cotton fabric, which adopts the following technical scheme: A green printing and dyeing process for the surface of cotton fabric, comprising the following steps: S1. Fabric pretreatment: cotton fabric is pretreated to remove surface impurities to obtain a pretreated substrate; S2, pre-dyeing: the pre-treated substrate in step S1 is first immersed in a pre-dyeing solution containing a natural colorant, and then dried to obtain a pre-dyed substrate; S3, modification: coating a modifier on the pre-dyed substrate in step S2 to form an intermediate layer, and then washing with a phosphate buffer to obtain a modified substrate, wherein the modifier is mainly prepared from an amine modifier, a microcapsule anionic dye, cotton fiber, epoxy resin, nano-silicon dioxide and an amine curing agent, wherein the microcapsule anionic dye comprises a core material, an inner layer and an outer layer, wherein the inner layer comprises acrylic resin, microcrystalline cellulose and polyvinyl chloride, and the outer layer comprises PEO, gelatin and chitosan; S4, adding a natural colorant to the pre-dyeing liquid after the pre-dyeing treatment in step S2, and adding a microcapsule anionic dye to form a dyeing liquid, and then immersing the modified substrate modified in step S3 in the dyeing liquid for dyeing, and then drying and curing, washing, and drying to obtain a dyed fabric.

[0008] By adopting the above technical scheme, in the present application, the cotton cloth is first pretreated to remove impurities on the cloth, and then it is first pre-dyed in a pre-dyeing solution containing a natural colorant to complete the preliminary dyeing to form a primary dyeing layer, and then it is coated with a modifier, and the addition of the modifier forms a thin film protective layer on the surface of the pre-dyed substrate, wherein the addition of microcapsule anionic dye is combined with the subsequent rinsing of the microcapsule anionic dye on the intermediate transition layer with a phosphate buffer, and the formed intermediate layer has a certain template pore structure, and then it is immersed in the dyeing solution, and the wall material of the microcapsule anionic dye gradually dissolves to achieve membrane breaking. Due to the addition of the amine modifier on the modified substrate, the surface of the modified substrate has cationic groups, and after the membrane is broken The anionic dye of the core material is close to the cationic group, and the adsorption effect of nano-silicon dioxide makes the anionic dye fit closely to the modified substrate. At the same time, due to the addition of polyethylene oxide in the inner layer, the wall material is away from the substrate and the anionic dye capsule is fixed on the substrate under the adhesive effect of acrylic resin, etc., so as to fix the dye, thereby improving the color fixation rate, reducing the residual dye in the wastewater, and reducing the difficulty of wastewater treatment. In addition, the present application undergoes a double treatment of pre-dyeing and dyeing, and the pre-dyeing layer is fixed by an intermediate layer, which further improves its color fixation rate, and the replacement of some natural dyes in pre-dyeing and dyeing further improves its environmental performance. Finally, the printing and dyeing process in the present application is more green and environmentally friendly, and the dye fixation rate is higher.

[0009] Optionally, the modifier in step S3 includes the following raw materials in parts by weight: 2.5-4 parts of amine modifier, 3-5 parts of microcapsule anionic dye, 1.5-2.5 parts of cotton fiber, 10-15 parts of epoxy resin, 1-3 parts of nano-silicon dioxide, 0.5-0.8 parts of silane coupling agent and 0.05-0.1 parts of amine curing agent.

[0010] By adopting the above technical scheme, the addition of amine modifiers can react with the hydroxyl groups in the cotton fibers to achieve cationic modification of the cotton fabric, thereby facilitating the subsequent curing of anionic dyes through electrostatic adsorption and improving the color fixation rate. The microcapsule anionic dye is used as a template to construct template holes in the modified layer, thereby facilitating the attachment of the microcapsule anionic dye during dyeing. The addition of nano-silicon dioxide can improve the air permeability of the intermediate layer by utilizing its pore structure, and can also enhance the bonding between the dye and the intermediate layer by utilizing its adsorption effect during the subsequent dyeing process. The combination of the layers improves the dyeing rate and the color fixation rate. The addition of epoxy resin serves as a film-forming material for the middle layer to form the middle layer. At the same time, the primary dyeing layer after pre-dyeing is fixed to a certain extent, so as to realize double-layer dyeing on the cotton fabric in the present application, and further improve its color fixation rate. The addition of cotton fiber plays a physical overlapping role between the cotton fabric substrate and the middle layer, and the amine modifier has a certain modifying effect on the cotton fiber while modifying the cotton fabric, so that the cotton fiber interspersed in the middle layer also has a certain cationic property, which improves the adsorption of anionic dyes during subsequent dyeing and improves the color fixation rate.

[0011] Optionally, 0.5-1.5 parts by weight of wood fiber are also added to the modifier raw material in step S3.

[0012] By adopting the above technical solution, the addition of wood fiber further improves the air permeability of the middle layer on the one hand, and forms a certain overlapping and entanglement effect with the cotton fiber on the other hand, thereby improving the stability of the middle layer.

[0013] Optionally, the amine modifier is selected from one or more of 2,3-epoxypropyltrimethylammonium chloride or epoxy ammonium salt.

[0014] Optionally, the core material of the microcapsule anionic dye is anionic dye, and the inner layer comprises acrylic resin, microcrystalline cellulose and polyvinyl chloride in a mass ratio of 1: (0.3-0.5): (0.1-0.15).

[0015] By adopting the above technical scheme, microcrystalline cellulose has the characteristic of high porosity. The addition of microcrystalline cellulose allows the outer layer to dissolve and water to enter the inner layer through the pores of the microcrystalline cellulose to wet and swell the inner layer during dyeing in the subsequent step S4, so that the inner layer breaks the wall to release the anionic dye core material to enter the template holes or adhere to the surface of the middle layer, thereby improving the dyeing rate and the color fixation rate. In addition, when the microcrystalline cellulose is added in the present application and the solvent is dried and removed after dyeing, a certain pore structure is formed after the solvent evaporates, thereby ensuring the air permeability of the dyed fabric. The addition of polyvinyl chloride as a non-polar or weakly polar substance has a large difference in polarity from the epoxy resin, so that after the microcapsule anionic dye breaks the wall, the internal anionic dye is adsorbed in the middle layer or the template holes. At the same time, the inner layer material is far away from the middle layer due to the polarity difference and subsequently achieves a coating effect on the color fixative under the action of viscosity, thereby improving the color fixation rate.

[0016] Optionally, the outer layer comprises PEO, gelatin and chitosan in a mass ratio of 1:(1-1.5):(2-3).

[0017] By adopting the above technical scheme, the outer layer formed by mixing the above raw materials has a certain film-forming wrapping property on the one hand, and is helpful for the subsequent flushing and removal of phosphate buffer to form template holes on the other hand. Moreover, when the microcapsule anionic dye breaks the membrane and disperses in the dyeing solution during dyeing, chitosan can promote the adsorption and penetration of the dye, improve the dyeing rate and levelness, and the addition of a small amount of PEO can reduce the concentration and reduce its effect on dye penetration.

[0018] Optionally, the mass ratio of the core material, the inner layer and the outer layer is 1:(0.6-0.8):(0.3-0.4).

[0019] By adopting the above technical solution, a certain number of template holes are formed when the above ratio is used, so that part of the microcapsule anionic dye is adsorbed in the template holes and the other part is adsorbed on the surface of the intermediate layer, and the final color fixing effect is better.

[0020] Optionally, the microcapsule anionic dye is prepared by the following method: 1) First, the acid dye, lauryl alcohol polyoxyethylene ether and water are mixed in a mass ratio of 1: (0.8-1.5): (10-12), stirred in a constant temperature water bath at 80°C for 15-20 minutes, and then processed in a colloid mill to obtain a core material solution; 2) After acrylic resin, microcrystalline cellulose and polyvinyl chloride are mixed in proportion to prepare an inner layer raw material, the inner layer raw material is dissolved in a water-ethanol mixture of 3-5 times the mass multiple to prepare an inner layer solution, and then the core material solution prepared in step 1) is added, and after stirring and mixing evenly, sodium lignin sulfonate is added, and the mass ratio of sodium lignin sulfonate to acid dye is 1: (2-3), and then homogenized and spray-dried to obtain primary microcapsule dye particles coated by the inner layer; 3) After mixing PEO, gelatin and chitosan in proportion to prepare the outer layer raw material, dissolve it in 4-5 times the mass of acetic acid-water mixed solution to prepare the outer layer solution, then add the primary microcapsule dye particles prepared in step 2), then add the cross-linking agent, stir and let stand, then centrifuge, wash and dry to obtain the microcapsule anionic dye.

[0021] Optionally, in step S2, the pre-dyeing immersion temperature is 65-80° C., the bath ratio of the pretreated substrate to the pre-dyeing solution is 1 g: (20-30) mL, the immersion time is 30-40 min, and the mass concentration of the natural colorant in the pre-dyeing solution is 3-5 g / L.

[0022] By adopting the above technical solution, low-temperature dyeing is achieved through the above treatment.

[0023] Optionally, the coating amount of the modifier in step S3 is 0.5-1.5 wt % of the amount added to the pre-dyed substrate.

[0024] Optionally, in step S4, the natural colorant is added to the pre-dyeing solution to a concentration of 3-5 g / L, and the microcapsule anionic dye is added to a concentration of 10-18 g / L. The immersion dyeing temperature in step S4 is 65-80°C, the bath ratio of the modified substrate to the dyeing solution is 1 g: (45-55) mL, and the immersion time is 30-40 min.

[0025] By adopting the above technical solution and the above dyeing system, less dye is added while the dyeing rate and fixation rate are higher. The chroma in the wastewater after dyeing is smaller and easier to handle, and the dyeing process is more environmentally friendly.

[0026] Optionally, the specific operation in step S1 is: immersing the cotton cloth in a sodium carbonate solution to obtain a pretreated substrate.

[0027] By adopting the above technical solution, the pretreatment method in the present application can not only effectively remove impurities on the fabric, but also reduce pollution to the environment.

[0028] In summary, this application has the following beneficial effects: 1. In the present application, cotton cloth is firstly pretreated to remove impurities on the cloth, and then it is first pre-dyed in a pre-dyeing solution containing a natural colorant to complete the preliminary dyeing to form a primary dyeing layer, and then it is coated with a modifier, and the addition of the modifier forms a thin film protective layer on the surface of the pre-dyed substrate, wherein the addition of microcapsule anionic dye cooperates with the subsequent rinsing of the microcapsule anionic dye on the intermediate transition layer with a phosphate buffer, and the formed intermediate layer has a certain template pore structure, and then it is immersed in the dyeing solution, and the wall material of the microcapsule anionic dye gradually dissolves to achieve film breaking. Due to the addition of amine modifiers on the modified substrate, the surface of the modified substrate carries cationic groups, and after the film is broken, the core material anionic dye is close to the cationic group, and then the adsorption effect of nano-silicon dioxide makes the anionic dye and the modified substrate closely fit. At the same time, due to the addition of polyethylene oxide in the inner layer, the wall material is away from the substrate and the anionic dye capsule is fixed on the substrate under the adhesive action of acrylic resin, etc., to achieve the fixation of the dye, thereby improving the color fixation rate, reducing the residual dye in the wastewater, and reducing the difficulty of wastewater treatment; 2. In this application, the double treatment of pre-dyeing and dyeing is performed, and the pre-dyeing layer is fixed by an intermediate layer, which further improves its color fixation rate, and the replacement of some natural dyes in pre-dyeing and dyeing further improves its environmental performance. Finally, the printing and dyeing process in this application is more green and environmentally friendly, and the dye fixation rate is higher. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0030] Anionic dyes in the present application are acid dyes.

[0031] In the following examples, the acrylic resin is water-based acrylic resin Neocryl XK-12 produced by DSM; the epoxy resin is epoxy resin E-44; The amine curing agent is an aliphatic amine curing agent, specifically isophoronediamine.

[0032] In the following examples, the cotton fiber powder and the wood fiber powder are obtained by crushing and grinding cotton fiber and wood fiber, respectively.

[0033] The natural colorants in the following examples are natural dyes such as turmeric powder, gardenia green, purple sweet potato pigment, phycocyanin-spirulina extract, etc.

[0034] The following preparation example is an example of the preparation of microcapsule anionic dyes Preparation Example 1 A microcapsule anionic dye comprises a core material, an inner layer and an outer layer arranged in sequence from the inside to the outside, wherein the core material is an acid dye, the inner layer is made of acrylic resin, microcrystalline cellulose and polyvinyl chloride in a mass ratio of 1:0.4:0.12, and the outer layer is made of PEO, gelatin and chitosan in a mass ratio of 1:1.2:2.5; The preparation method comprises the following steps: 1) First, the acid dye, lauryl alcohol polyoxyethylene ether and water are mixed in a mass ratio of 1:1.2:11, stirred in a constant temperature water bath at 80°C for 20 minutes, and then processed in a colloid mill to obtain a core material solution; 2) After acrylic resin, microcrystalline cellulose and polyvinyl chloride are mixed in proportion to prepare an inner layer raw material, the inner layer raw material is dissolved in a water-ethanol mixture (the mass ratio of water to ethanol is 1:2.5) with a mass multiple of 4 times to prepare an inner layer solution, and then the core material solution prepared in step 1) is added, and after stirring and mixing evenly, sodium lignin sulfonate is added, and the mass ratio of sodium lignin sulfonate to acid dye is 1:2.5, and then the primary microcapsule dye particles coated by the inner layer are obtained after homogenization and spray drying; 3) After mixing PEO, gelatin and chitosan in proportion to obtain an outer layer raw material, dissolve it in 4-5 times the mass of an acetic acid-water mixed solution (the mass ratio of acetic acid to water is 1:1.3) to prepare an outer layer solution, then add the primary microcapsule dye particles prepared in step 2), then add sodium tripolyphosphate crosslinking agent, stir for 45 minutes, let stand for 15 minutes, then centrifuge, wash and dry to obtain a microcapsule anionic dye; Among them, the above-mentioned acid dye is used as the core material, and the added mass ratio of the core material, the inner layer raw material and the outer layer raw material is 1:0.7:0.3.

[0035] Preparation Example 2 A microcapsule anionic dye comprises a core material, an inner layer and an outer layer arranged in sequence from the inside to the outside, wherein the core material is an acid dye, the inner layer is made of acrylic resin, microcrystalline cellulose and polyvinyl chloride in a mass ratio of 1:0.3:0.1, and the outer layer is made of PEO, gelatin and chitosan in a mass ratio of 1:1:2; The preparation method comprises the following steps: 1) First, the acid dye, lauryl alcohol polyoxyethylene ether and water are mixed in a mass ratio of 1:0.8:10, stirred in a constant temperature water bath at 80°C for 15 minutes, and then processed in a colloid mill to obtain a core material solution; 2) After acrylic resin, microcrystalline cellulose and polyvinyl chloride are mixed in proportion to prepare an inner layer raw material, the inner layer raw material is dissolved in a water-ethanol mixture (water and ethanol are added in a mass ratio of 1:2) at a multiple of 3 times by mass to prepare an inner layer solution, and then the core material solution prepared in step 1) is added, and after stirring and mixing evenly, sodium lignin sulfonate is added, and the mass ratio of sodium lignin sulfonate to acid dye is 1:2, and then the raw material is homogenized and spray-dried to obtain primary microcapsule dye particles coated by the inner layer; 3) After PEO, gelatin and chitosan are mixed in proportion to obtain an outer layer raw material, the outer layer raw material is dissolved in 4 times the mass of an acetic acid-water mixed solution (the mass ratio of acetic acid to water is 1:1.2) to prepare an outer layer solution, and then the primary microcapsule dye particles prepared in step 2) are added, and then sodium tripolyphosphate crosslinking agent is added, stirred for 40 minutes, and then allowed to stand for 10 minutes, and then centrifuged, washed and dried to obtain a microcapsule anionic dye; Among them, the above-mentioned acid dye is used as the core material, and the added mass ratio of the core material, the inner layer raw material and the outer layer raw material is 1:0.6:0.3.

[0036] Preparation Example 3 A microcapsule anionic dye comprises a core material, an inner layer and an outer layer arranged in sequence from the inside to the outside, wherein the core material is an acid dye, the inner layer is made of acrylic resin, microcrystalline cellulose and polyvinyl chloride in a mass ratio of 1:0.5:0.15, and the outer layer is made of PEO, gelatin and chitosan in a mass ratio of 1:1.5:3; The preparation method comprises the following steps: 1) First, the acid dye, lauryl alcohol polyoxyethylene ether and water are mixed in a mass ratio of 1:1.5:12, stirred in a constant temperature water bath at 80°C for 20 minutes, and then processed in a colloid mill to obtain a core material solution; 2) After acrylic resin, microcrystalline cellulose and polyvinyl chloride are mixed in proportion to prepare an inner layer raw material, the inner layer raw material is dissolved in a water-ethanol mixture (water and ethanol are added in a mass ratio of 1:3) at a multiple of 5 times by mass to prepare an inner layer solution, and then the core material solution prepared in step 1) is added, and after stirring and mixing evenly, sodium lignin sulfonate is added, and the mass ratio of sodium lignin sulfonate to acid dye is 1:3, and then the mixture is homogenized and spray-dried to obtain primary microcapsule dye particles coated by the inner layer; 3) After PEO, gelatin and chitosan are mixed in proportion to obtain an outer layer raw material, the outer layer raw material is dissolved in 5 times the mass of an acetic acid-water mixed solution (the mass ratio of acetic acid to water is 1:1.5) to prepare an outer layer solution, and then the primary microcapsule dye particles prepared in step 2) are added, and then sodium tripolyphosphate crosslinking agent is added, stirred for 50 minutes, and then allowed to stand for 20 minutes, and then centrifuged, washed and dried to obtain a microcapsule anionic dye; Among them, the above-mentioned acid dye is used as the core material, and the added mass ratio of the core material, the inner layer raw material and the outer layer raw material is 1:0.8:0.4.

[0037] Comparative Preparation Example 1 A microcapsule anionic dye and a preparation method thereof are prepared according to the method in Preparation Example 1, except that no microcrystalline cellulose is added to the inner layer raw material.

[0038] Comparative Preparation Example 2 A microcapsule anionic dye and a preparation method thereof are prepared according to the method in Preparation Example 1, except that polyvinyl chloride is not added to the inner layer raw material.

[0039] Comparative Preparation Example 3 A microcapsule anionic dye and a preparation method thereof are prepared according to the method in Preparation Example 1, except that no outer layer coating design is performed.

[0040] Example 1 A green printing and dyeing process for the surface of cotton fabric, comprising the following steps: S1. Fabric pretreatment: first immerse the cotton cloth in a 1-3 g / L sodium carbonate solution, the bath ratio of the cotton cloth to the sodium carbonate solution is 1 g: 18 mL, and the immersion temperature is 80° C. to obtain a pretreated substrate; S2, pre-dyeing: the pre-treated substrate in step S1 is first immersed in a pre-dyeing solution containing a natural colorant, the pre-dyeing immersion temperature is 70°C, the bath ratio of the pre-treated substrate to the pre-dyeing solution is 1g:25mL, the immersion time is 35min, the mass concentration of the natural colorant in the pre-dyeing solution is 4g / L, and then dried to obtain a pre-dyed substrate; S3, modification: after coating the pre-dyed substrate in step S2 with a modifier, curing it at 70° C. for 50 min to form an intermediate layer, and then washing it with 0.2 M phosphate buffer to obtain a modified substrate, the coating amount of the modifier is 1wt% of the amount added to the pre-dyed substrate, and the modifier is prepared by mixing the following raw materials: 3g of an amine modifier, 4g of the microcapsule anionic dye prepared in Preparation Example 1, 2g of cotton fiber, 12g of epoxy resin, 2g of nano-silica, 0.6g of silane coupling agent KH-550 and 0.08g of an amine curing agent, wherein the amine modifier is 2,3-epoxypropyltrimethylammonium chloride; S4, adding a natural colorant to the pre-dyeing residual liquid after the pre-dyeing treatment in step S2 to a concentration of 4 g / L, and adding a microcapsule anionic dye to a concentration of 14 g / L (finally, each 1L of dyeing liquid contains 14g of microcapsule anionic dye particles) to form a dyeing liquid, and then immersing the modified substrate modified in step S3 in the dyeing liquid for dyeing, the immersion dyeing temperature is 70°C, the bath ratio of the modified substrate to the dyeing liquid is 1g:50mL, the immersion time is 35min, and then drying, curing, washing, and drying to obtain a dyed fabric.

[0041] Example 2 A green printing and dyeing process for the surface of cotton fabric, comprising the following steps: S1. Fabric pretreatment: first immerse the cotton cloth in a 1 g / L sodium carbonate solution, the bath ratio of the cotton cloth to the sodium carbonate solution is 1 g:15 mL, and the immersion temperature is 80° C. to obtain a pretreated substrate; S2, pre-dyeing: the pre-treated substrate in step S1 is first immersed in a pre-dyeing solution containing a natural colorant, the pre-dyeing immersion temperature is 65°C, the bath ratio of the pre-treated substrate to the pre-dyeing solution is 1g:20mL, the immersion time is 40min, the mass concentration of the natural colorant in the pre-dyeing solution is 3g / L, and then dried to obtain a pre-dyed substrate; S3, modification: after coating the pre-dyed substrate in step S2 with a modifier, curing at 60° C. for 60 min to form an intermediate layer, and then washing with 0.2 M phosphate buffer to obtain a modified substrate, the coating amount of the modifier is 0.5 wt % of the amount added to the pre-dyed substrate, and the modifier is prepared by mixing the following raw materials: 2.5 g of an amine modifier, 3 g of the microcapsule anionic dye prepared in Preparation Example 2, 1.5 g of cotton fiber, 10 g of epoxy resin, 1 g of nano-silica, 0.5 g of silane coupling agent KH-550 and 0.05 g of an amine curing agent, wherein the amine modifier is 2,3-epoxypropyltrimethylammonium chloride; S4, adding a natural colorant to the pre-dyeing residual liquid after the pre-dyeing treatment in step S2 to a concentration of 3g / L, and adding a microcapsule anionic dye to a concentration of 10g / L (finally, each 1L of dyeing liquid contains 10g of microcapsule anionic dye particles) to form a dyeing liquid, and then immersing the modified substrate modified in step S3 in the dyeing liquid for dyeing, the immersion dyeing temperature is 65°C, the bath ratio of the modified substrate to the dyeing liquid is 1g:45mL, the immersion time is 40min, and then drying, curing, washing, and drying to obtain a dyed fabric.

[0042] Example 3 A green printing and dyeing process for the surface of cotton fabric, comprising the following steps: S1. Fabric pretreatment: first immerse the cotton cloth in a 3 g / L sodium carbonate solution, the bath ratio of the cotton cloth to the sodium carbonate solution is 1 g: 20 mL, and the immersion temperature is 80° C. to obtain a pretreated substrate; S2, pre-dyeing: the pre-treated substrate in step S1 is first immersed in a pre-dyeing solution containing a natural colorant, the pre-dyeing immersion temperature is 80°C, the bath ratio of the pre-treated substrate to the pre-dyeing solution is 1g:30mL, the immersion time is 30min, the mass concentration of the natural colorant in the pre-dyeing solution is 5g / L, and then dried to obtain a pre-dyed substrate; S3, modification: after coating the pre-dyed substrate in step S2 with a modifier, curing at 80° C. for 40 min to form an intermediate layer, and then washing with 0.2 M phosphate buffer to obtain a modified substrate, the coating amount of the modifier is 1.5 wt % of the amount added to the pre-dyed substrate, and the modifier is prepared by mixing the following raw materials: 4 g of an amine modifier, 5 g of the microcapsule anionic dye prepared in Preparation Example 3, 2.5 g of cotton fiber, 15 g of epoxy resin, 3 g of nano-silica, 0.8 g of silane coupling agent KH-550 and 0.1 g of an amine curing agent, wherein the amine modifier is 2,3-epoxypropyltrimethylammonium chloride; S4, adding a natural colorant to the pre-dyeing residual liquid after the pre-dyeing treatment in step S2 to a concentration of 5g / L, and adding a microcapsule anionic dye to a concentration of 18g / L (finally, each 1L of dyeing liquid contains 18g of microcapsule anionic dye particles) to form a dyeing liquid, and then immersing the modified substrate modified in step S3 in the dyeing liquid for dyeing, the immersion dyeing temperature is 80°C, the bath ratio of the modified substrate to the dyeing liquid is 1g:55mL, the immersion time is 30min, and then drying, curing, washing, and drying to obtain a dyed fabric.

[0043] Example 4 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that 1g of wood fiber is also added to the modifier raw material.

[0044] Example 5 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that 0.5 g of wood fiber is also added to the modifier raw material.

[0045] Example 6 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that 1.5 g of wood fiber is also added to the modifier raw material.

[0046] Comparative Example 1 A green printing and dyeing process for the surface of a cotton fabric is carried out according to the method in Example 1, except that step S2 is not performed and step S3 is directly performed.

[0047] Comparative Example 2 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that step S4 is directly carried out without step S3, and the microcapsule anionic dye in step S4 is directly replaced by the core material acid dye in step S3.

[0048] Comparative Example 3 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that no nano-silicon dioxide is added to the modifier in step S3.

[0049] Comparative Example 4 A green printing and dyeing process for the surface of a cotton fabric is carried out according to the method in Example 1, except that no cotton fiber is added in step S2.

[0050] Comparative Examples 5-6 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that the microcapsule anionic dyes in step S3 are respectively selected from the microcapsule anionic dyes prepared in Comparative Preparation Example 1 and Comparative Preparation Example 2.

[0051] Comparative Example 7 A green printing and dyeing process for the surface of cotton fabric is carried out according to the method in Example 1, except that the microcapsule anionic dye in step S3 is selected from the microcapsule anionic dye prepared in comparative preparation example 3, and in step S3, a mixed solution of water and ethanol in a mass ratio of 1:2.5 is used for washing to form template holes.

[0052] Performance Testing The air permeability, dye uptake in step S4 and color fastness of the dyed cotton fabrics prepared in the examples and comparative examples of the present application were tested. The air permeability was tested with reference to GB / T 5453 "Determination of Air Permeability of Textile Fabrics", the dye uptake was tested by the dyeing residual liquid method, the color fastness was tested for rubbing fastness with reference to GB / T 3920-2008, and the fastness to soaping was tested with reference to GB / T 3921-2008. The test results are shown in Table 1 below.

[0053] Table 1: Table 1 continued: Referring to the test results in Table 1 above, the dyed fabric prepared in the embodiment of the present application has excellent dye uptake rate, and its color fixation rate is high, there is less residual dye in the residual liquid, the color value is lower, it is easier to handle, more green and environmentally friendly, and has excellent air permeability.

[0054] Referring to the test results in Example 1 and Comparative Example 1, in Comparative Example 1, no pre-dyeing treatment was performed, and the substrate after alkali treatment was directly subjected to intermediate layer modification in step S3 and dyeing treatment in step S4. It can be seen that the color fixation rate is reduced. Combined with the test results in Comparative Example 2, the intermediate layer treatment in step S3 was not performed, and the acid dye was directly subjected to dyeing treatment in step S4. It can be seen that when the dyeing rate is significantly reduced, its rubbing fastness is also significantly reduced; combined with the test results of Comparative Examples 3 and 4, when nano-silicon dioxide or cotton fiber is not added to the modifier in step S3, the binding effect on the acid dye is reduced, and its color fastness and dyeing rate are reduced. Referring to the test results of Comparative Examples 5 and 6, when microcrystalline cellulose was not added to the inner layer of the microcapsule anionic dye in Comparative Example 5, its air permeability was significantly reduced, and when polyvinyl chloride was not added to the inner layer in Comparative Example 6, its color fastness was significantly reduced rapidly. Combined with the test results of Comparative Example 7, when there was no outer layer coating in Comparative Example 7 and only the inner layer was used as the wall material, its dyeing rate was reduced, and it can be clearly seen that the dyeing was uneven and the levelness was reduced.

[0055] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A green printing and dyeing process for the surface of cotton fabric, characterized in that: The following steps are involved: S1. Fabric pretreatment: cotton fabric is pretreated to remove surface impurities to obtain a pretreated substrate; S2, pre-dyeing: the pre-treated substrate in step S1 is first immersed in a pre-dyeing solution containing a natural colorant, and then dried to obtain a pre-dyed substrate; S3, modification: coating a modifier on the pre-dyed substrate in step S2 to form an intermediate layer, and then washing with a phosphate buffer to obtain a modified substrate, wherein the modifier is mainly prepared from an amine modifier, a microcapsule anionic dye, cotton fiber, epoxy resin, nano-silicon dioxide and an amine curing agent, wherein the microcapsule anionic dye comprises a core material, an inner layer and an outer layer, wherein the inner layer comprises acrylic resin, microcrystalline cellulose and polyvinyl chloride, and the outer layer comprises PEO, gelatin and chitosan; S4, adding a natural colorant to the pre-dyeing liquid after the pre-dyeing treatment in step S2, and adding a microcapsule anionic dye to form a dyeing liquid, and then immersing the modified substrate modified in step S3 in the dyeing liquid for dyeing, and then drying and curing, washing, and drying to obtain a dyed fabric.

2. A green printing and dyeing process for cotton fabric surface according to claim 1, characterized in that: The modifier in step S3 includes the following raw materials in parts by weight: 5-4 parts of amine modifier, 3-5 parts of microcapsule anionic dye, 1.5-2.5 parts of cotton fiber, 10-15 parts of epoxy resin, 1-3 parts of nano-silicon dioxide, 0.5-0.8 parts of silane coupling agent and 0.05-0.1 parts of amine curing agent.

3. A green printing and dyeing process for cotton fabric surface according to claim 2, characterized in that: 0.5-1.5 parts by weight of wood fiber are also added to the modifier raw material in step S3.

4. A green printing and dyeing process for cotton fabric surface according to claim 1, characterized in that: The amine modifier is selected from one or more of 2,3-epoxypropyltrimethylammonium chloride or epoxy ammonium salt.

5. The green printing and dyeing process for the surface of cotton fabric according to claim 1, characterized in that: The core material of the microcapsule anionic dye is anionic dye, and the inner layer includes acrylic resin, microcrystalline cellulose and polyvinyl chloride in a mass ratio of 1: (0.3-0.5): (0.1-0.15); The outer layer includes PEO and gelatin and chitosan in a mass ratio of 1:(1-1.5):(2-3).

6. A green printing and dyeing process for cotton fabric surface according to claim 1, characterized in that: The mass ratio of the core material, the inner layer and the outer layer is 1:(0.6-0.8):(0.3-0.4).

7. A green printing and dyeing process for cotton fabric surface according to claim 1, characterized in that: In step S2, the pre-dyeing immersion temperature is 65-80°C, the bath ratio of the pre-treated substrate to the pre-dyeing solution is 1g: (20-30)mL, the immersion time is 30-40min, and the mass concentration of the natural colorant in the pre-dyeing solution is 3-5g / L.

8. The green printing and dyeing process for the surface of cotton fabric according to claim 1, characterized in that: The amount of the modifier applied in step S3 is 0.5-1.5 wt % of the amount of the pre-dyed substrate added.

9. A green printing and dyeing process for cotton fabric surface according to claim 1, characterized in that: In step S4, the natural colorant is added to the pre-dyeing solution to a concentration of 3-5 g / L, and the microcapsule anionic dye is added to a concentration of 10-18 g / L. The immersion dyeing temperature in step S4 is 65-80° C., the bath ratio of the modified substrate to the dyeing solution is 1 g: (45-55) mL, and the immersion time is 30-40 min.

10. A green printing and dyeing process for cotton fabric surface according to claim 1, characterized in that: The specific operation in step S1 is: immersing the cotton cloth in a sodium carbonate solution to obtain a pretreated substrate.

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