Dyeing method of salt-free alkali-free reactive dye for real silk fabric

Abstract

The invention discloses a dyeing method of a salt-free alkali-free reactive dye for a real silk fabric, which comprises the following steps: S1, pretreatment of the real silk fabric: soaping the real silk fabric, and drying for later use; s2, modification treatment of the real silk fabric: soaking the real silk fabric treated in S1 in a finishing agent at room temperature, and taking out and drying the real silk fabric; s3, dyeing with an active dye: immersing the real silk fabric treated in the step S1 into water, fully wetting, then putting into the prepared active dye liquor for dyeing, dipping twice and rolling twice, and finally baking at 50-80 DEG C until the real silk fabric is dried. According to the method, the use of salt and alkali is avoided, the demand of auxiliaries in the dyeing process is remarkably reduced, the discharge of high-salinity printing and dyeing wastewater caused by the use of a large amount of electrolyte is reduced, and the problems of ecological environment pollution and soil salinization are effectively relieved.

Description

Technical Field

[0001] The invention relates to the technical field of dyeing, and in particular to a method for dyeing silk fabrics with salt-free and alkali-free reactive dyes. Background Art

[0002] Silk has a unique jewel-like luster, natural luxury, soft touch, smooth and comfortable feel. It is commonly dyed with acid dyes and direct dyes, but has low color fastness. It has excellent wearability, biocompatibility and biodegradability, and is widely used in textile, biomedicine, food and other fields.

[0003] Reactive dyes are widely used in dyeing and printing cellulose fiber fabrics and protein fiber fabrics due to their wide color range, bright colors, good color fastness, and strong applicability. Silk fiber is the only protein filament fiber produced on a large scale in China. It has the characteristics of elegant appearance, gloss, biodegradability, skin-friendliness, drape performance, high hygroscopicity, and breathability. It is often used in the production of high-end clothing and high-end household items. It has become one of the key fabrics for reactive dye inkjet printing, and silk printed fabrics are becoming more and more popular. However, compared with cellulose, the molecular chain structure of protein is more complex, and the nucleophilic groups, such as amino, phenolic hydroxyl, alcoholic hydroxyl and thiol, make its chemical reaction with reactive dyes more complicated.

[0004] Reactive dyes are anionic dyes that contain one or more sulfonic acid groups in their structure. They have good water solubility and are negatively charged in water. They are mainly used for cellulose fibers. Because they contain a large number of hydroxyl groups in their structure, the fiber surface also exhibits negative charge due to ionization in water. Therefore, the most prominent problem of reactive dyes is the low exhaustion rate and fixation rate. In actual production, in order to improve the utilization rate of dyes, a large amount of inorganic salts (such as NaCl, Na 2 SO4, etc., the dosage is generally between 30-150g / L) to overcome the charge repulsion between dye and fiber, thereby increasing the dyeing rate. The large amount of inorganic salts used causes a high salt content in printing and dyeing wastewater. Discharge will cause damage to the ecological environment and water resources, and salinization of soil around rivers and lakes. In addition, the inorganic salts in the wastewater are difficult to handle and cannot be biodegraded.

[0005] The color fastness of silk dyed with reactive dyes is very high, but a large amount of high-chroma, high-salt wastewater will be produced. The dyeing wastewater containing a large amount of inorganic salts is difficult to treat, and direct discharge will aggravate environmental pollution and destroy the ecological balance. In order to improve the utilization rate of reactive dyes and reduce the amount of salt used, people have conducted research on dyeing methods, silk surface modification, modified reactive dyes, and cationic surfactant dyeing. Therefore, for economic development and in response to the country's call for energy conservation, emission reduction, and green environmental protection, it is necessary to develop a salt-free and alkali-free reactive dyeing process. Summary of the invention

[0006] The purpose of the present invention is to provide a method for dyeing silk fabrics with salt-free and alkali-free reactive dyes, which avoids the use of salt and alkali, significantly reduces the demand for auxiliaries in the dyeing process, reduces the discharge of high-salinity printing and dyeing wastewater caused by the use of a large amount of electrolytes, and effectively alleviates ecological environmental pollution and soil salinization problems.

[0007] The technical solution adopted by the present invention to solve the technical problem is: A method for dyeing silk fabric with salt-free and alkali-free reactive dyes comprises the following steps: S1. Pretreatment of silk fabric: Soap-wash the silk fabric and dry it for later use; S2, modification treatment of silk fabric: soak the silk fabric treated by S1 in a finishing agent at room temperature, take it out and dry it; the finishing agent is composed of: 2-10wt% dimethyldiallylammonium chloride, 2-10wt% glycidyl methacrylate, 0.8-1.2wt% initiator, 0.4-0.6wt% catalyst, and the balance deionized water; S3. Dyeing with reactive dyes: soak the silk fabric treated with S1 in water to fully wet it, then put it into the prepared reactive dye solution for dyeing, double immersion and double rolling, and finally bake it at 50-80°C until it is dry.

[0008] The soap washing times are 3 times, the soap washing temperature is 50°C, the soap washing time is 30 minutes each time, and the soap washing liquid is composed of 5 wt% of soap washing powder and 95 wt% of water.

[0009] In S2, the initiator is ammonium persulfate.

[0010] In S2, the catalyst is tetramethylethylenediamine.

[0011] In S2, the soaking time at room temperature is 1-5 hours.

[0012] In S3, the dyeing temperature is 50-65°C and the bath ratio is 1:10-1:15.

[0013] In S3, the dipping time of the double dipping and double rolling is 5 minutes, and the dipping and rolling liquid rate is 70-80%.

[0014] In S2, the silk fabric treated in S1 is immersed in the finishing agent at room temperature. The specific operation is: add dimethyldiallylammonium chloride and glycidyl methacrylate into deionized water, stir and mix, add initiator, then immerse the silk fabric therein, add catalyst, and immerse at room temperature.

[0015] The invention uses ammonium persulfate (APS) as an initiator and tetramethylethylenediamine (TEMED) as a catalyst to polymerize dimethyldiallylammonium chloride (DADMAC) and glycidyl methacrylate (GMA) through carbon-carbon double bonds on the surface of a silk fabric, and introduces a cationic group and an epoxy group into the surface of the silk fabric. When the silk fabric is dyed with a reactive dye, electrostatic adsorption is formed with the cationic group, and covalent cross-linking is generated with the epoxy group at a high temperature during baking, thereby improving the dyeing rate and color fastness of the silk fabric dyed with the reactive dye. The dyeing process does not involve the use of salt and alkali, thereby reducing the use of dyeing auxiliaries when the reactive dye is dyed with the silk, avoiding the discharge of printing and dyeing wastewater caused by the use of a large amount of salt and alkali, reducing the burden of sewage treatment, improving production costs, and protecting the environment.

[0016] The reactions involved on the silk fabric surface are as follows:

[0017] The beneficial effects of the present invention are: (1) Ammonium persulfate (APS) was used as an initiator to initiate a carbon-carbon double bond polymerization reaction between dimethyldiallylammonium chloride (DADMAC) and glycidyl methacrylate (GMA) on the surface of silk fabric under specific conditions. In this process, tetramethylethylenediamine (TEMED) was used as a catalyst to accelerate the reaction. Through this polymerization reaction, cationic groups and epoxy groups were successfully introduced into the surface of silk fabric.

[0018] (2) During the process of dyeing silk fabric with reactive dyes, on the one hand, electrostatic adsorption is formed between the cationic groups on the surface of the silk fabric and the reactive dyes. This electrostatic adsorption can enhance the binding force between the reactive dyes and the silk fabric, thereby improving the dyeing rate of the reactive dyes. On the other hand, during the baking stage, the epoxy groups on the surface of the silk fabric will undergo a covalent cross-linking reaction with the reactive dyes at high temperatures. This covalent cross-linking further enhances the binding stability between the reactive dyes and the silk fabric, thereby improving the color fastness of the reactive dyes on the silk fabric.

[0019] (3) By introducing cationic groups and epoxy groups on the surface of silk fabrics, the dyeing rate and color fastness of silk fabrics dyed with reactive dyes are significantly improved by utilizing electrostatic adsorption and covalent cross-linking respectively. The improvement of dyeing rate means that less dye can be used to achieve the same dyeing effect, reducing the consumption of dyes. The improvement of color fastness ensures that the dyed silk fabric is not easy to fade during use, thus improving the quality and service life of the product.

[0020] (4) The traditional process of dyeing silk fabrics with reactive dyes usually requires the use of a large amount of salt and alkali as dyeing auxiliaries. The use of these salts and alkalis will not only increase production costs, but also bring serious problems in the discharge of printing and dyeing wastewater. The present invention avoids the use of a large amount of salt and alkali, reduces the discharge of printing and dyeing wastewater, and reduces the burden of sewage treatment. The salt-free and alkali-free dyeing process meets the current environmental protection requirements and helps promote the sustainable development of the textile printing and dyeing industry. At the same time, reducing the use of dyeing auxiliaries also reduces production costs and improves the economic benefits of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a comparison chart of the apparent colors of the silk fabrics obtained after they are dyed with the reactive dyes of the present invention and comparative example 1. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below through specific embodiments.

[0023] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are all conventional methods in the art.

[0024] In the present invention, glycidyl methacrylate (GMA, purity ≥ 98.5%) was purchased from Sigma Company in the United States, dimethyldiallylammonium chloride (DADMAC) was purchased from Tokyo Chemical Industry Co., Ltd. in Japan, ammonium persulfate (APS) and tetramethylethylenediamine (TEMED) were both purchased from Sinopharm Chemical Reagent Co., Ltd., and soap powder: Omo antibacterial and anti-mite laundry detergent was purchased from Unilever Limited.

[0025] Embodiment 1: (1) The silk fabric was soaped 3 times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and air-dried at room temperature. The air-dried silk fabric was cut into the predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0026] (2) 2 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water and stirred for 20 min. 1 wt % of initiator ammonium persulfate (APS) was added. Then, the silk fabric was immersed in the mixed solution. 0.5 wt % of tetramethylethylenediamine (TEMED) was added and immersed at room temperature for 2 h. The fabric was dried in an oven at 50 ° C.

[0027] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into a 2% owf reactive red LS dye solution (composition: reactive red LS dye 2% owf and deionized water) with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a drying machine and baked at 70°C for 5 minutes.

[0028] Embodiment 2: (1) The silk fabric was soaped 3 times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and then dried. The silk fabric after drying was cut into the predetermined experimental mass (5 g), and the edge yarn was cut off, and then dried in a constant temperature oven at 50°C for 30 min.

[0029] (2) 4 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0030] (3) The treated and dried silk fabric was immersed in water for 5 minutes to fully wet it, and then put it into a 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two pads (the two immersion times were 5 minutes each, and the padding liquid rate was 75%), the dyeing process temperature was 60°C, and then the fabric was placed in a drying machine and baked at 70°C for 5 minutes.

[0031] Embodiment 3: (1) The silk fabric was soaped 3 times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and air-dried at room temperature. The air-dried silk fabric was cut into the predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0032] (2) 6 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0033] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0034] Embodiment 4: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0035] (2) 8 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0036] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0037] Embodiment 5: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0038] (2) 10 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0039] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0040] Embodiment 6: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0041] (2) 6 wt % of dimethyldiallylammonium chloride and 2 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0042] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0043] Embodiment 7: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0044] (2) 6 wt % of dimethyldiallylammonium chloride and 6 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0045] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0046] Embodiment 8: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0047] (2) 6 wt % of dimethyldiallylammonium chloride and 8 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0048] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0049] Embodiment 9: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0050] (2) 6 wt % of dimethyldiallylammonium chloride and 10 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 2 h, and dried in an oven at 50 ° C.

[0051] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0052] Embodiment 10: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0053] (2) 6 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 1 h, and dried in an oven at 50 ° C.

[0054] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0055] Embodiment 11: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0056] (2) 6 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 3 h, and dried in an oven at 50 ° C.

[0057] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0058] Embodiment 12: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0059] (2) 6 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 0.8 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.4 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 4 h, and dried in an oven at 50 ° C.

[0060] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:15 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 70%), the dyeing process temperature is 50°C, and then the fabric is placed in a baking machine and baked at 50°C for 10 minutes.

[0061] Embodiment 13: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0062] (2) 6 wt % of dimethyldiallylammonium chloride and 4 wt % of glycidyl methacrylate were added to 20 mL of deionized water in proportion, stirred for 20 min, 1.2 wt % of initiator ammonium persulfate (APS) was added, and then the silk fabric was immersed in the mixed solution, and 0.6 wt % of tetramethylethylenediamine (TEMED) was added, immersed at room temperature for 5 h, and dried in an oven at 50 ° C.

[0063] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into a 2% owf reactive red LS dye solution with a bath ratio of 5% for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 80%), the dyeing process temperature is 65°C, and then the fabric is placed in a drying machine and baked at 80°C for 5 minutes.

[0064] Comparative Example 1: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0065] (2) The dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0066] Comparative Example 2: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0067] (2) 6 wt % of dimethyldiallylammonium chloride was added to 20 mL of deionized water, stirred for 20 min, and 1 wt % of initiator ammonium persulfate (APS) was added to prepare a finishing agent. The silk fabric was then immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added. The fabric was immersed at room temperature for 2 h and dried in an oven at 50 ° C.

[0068] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0069] Comparative Example 3: (1) The silk fabric was soaped three times (soaping temperature 50°C, time 30 min; the soaping solution consisted of 5 wt% soaping powder and 95 wt% water), and dried at room temperature. The dried silk fabric was cut into a predetermined experimental mass (5 g), and the edge yarn was cut off, and dried in a constant temperature oven at 50°C for 30 min.

[0070] (2) 4 wt % of glycidyl methacrylate was added to 20 mL of deionized water according to a certain ratio, stirred for 20 min, and 1 wt % of initiator ammonium persulfate (APS) was added to prepare a finishing agent. The silk fabric was then immersed in the mixed solution, and 0.5 wt % of tetramethylethylenediamine (TEMED) was added. The fabric was immersed at room temperature for 2 h, and then dried in an oven at 50° C.

[0071] (3) The treated and dried silk fabric is immersed in water for 5 minutes to fully wet it, and then put into 2% owf reactive red LS dye solution with a bath ratio of 1:10 for padding dyeing, two immersions and two paddings (the two immersion times are 5 minutes each, and the padding liquid rate is 75%), the dyeing process temperature is 60°C, and then the fabric is placed in a baking machine and baked at 70°C for 5 minutes.

[0072] Performance Testing: The surface color characteristic values ​​L, a, b, and K / S of dyed fabrics were tested using a Datacolor colorimeter under D65 light source and 10° viewing angle.

[0073] The color fastness to rubbing is determined in accordance with GB / T 3920-2008 “Textiles—Tests for Color Fastness—Color Fastness to Rubbing”.

[0074] The color fastness to washing is determined in accordance with GB / T 3921-2008 “Textiles—Tests for Color Fastness—Colour Fastness to Washing with Soap: Test 1”.

[0075] The apparent color comparison of silk fabrics modified with dimethyldiallylammonium chloride (DADMAC) and glycidyl methacrylate (GMA) and untreated silk fabrics after dyeing with reactive dyes is shown in Figure 1 (Conventional dyeing is Comparative Example 1). from Figure 1 The optical images of the silk fabric before and after dyeing can intuitively show that compared with the untreated silk fabric, the modified silk fabric is darker in color after dyeing, and the dye uptake rate is improved to a greater extent. The dye uptake rate of the unmodified silk fabric (Comparative Example 1) is 1.15%, while the dye uptake rate of the modified silk fabric (Example 3) is 50.6%, which is much higher than the dye uptake rate of the untreated silk fabric.

[0077] Table 1 shows the comparison of the apparent color depth K / S value and the different color fastness properties of the silk fabric modified with dimethyldiallylammonium chloride (DADMAC) and glycidyl methacrylate (GMA) and the untreated silk fabric after dyeing with reactive dyes.

[0078] The K / S value directly reflects the color depth after fabric dyeing. From the data in the table, it can be seen that the K / S value range in the embodiment is roughly between 13.68 and 20.35. Wherein, the K / S value of embodiment 3 reaches 20.35, which is the highest value in the embodiment, which shows that under the corresponding modification and dyeing conditions, the silk fabric obtains a darker apparent color after dyeing. On the whole, there is a certain fluctuation in the K / S value between the embodiments, but it is at a relatively considerable level, reflecting that after modification with dimethyldiallylammonium chloride (DADMAC) and glycidyl methacrylate (GMA), the adsorption effect of silk fabric on reactive dyes is better, so that the color after dyeing is more intense visually, and the dyeing effect is improved to a certain extent. The K / S value of the comparative example group is in the interval of 9.74 to 12.63, which is significantly lower than the numerical value of the embodiment group. For example, the K / S value of comparative example 1 is only 9.74, which is significantly different from that of embodiment 3. This fully demonstrates that when unmodified silk fabrics are dyed with reactive dyes, their adsorption capacity for dyes is relatively weak, and the final apparent color depth is shallow. The color depth indicator intuitively reflects the importance of modification treatment in improving the dyeing effect of silk fabrics.

[0079] Soap fastness is related to the color stability of fabrics during washing. The grades of the embodiments are mostly concentrated between 3 and 4. Like Example 3 and Example 4, they all reached 4 levels, which means that these modified silk fabrics have a small degree of color change after undergoing the soaping process, and the dyes on the fabrics can be attached more firmly, showing good soaping resistance, reflecting that the modification process forms a relatively stable combination between the silk fabric and the reactive dye, which can resist the influence of the chemical action in the soaping process on the dyeing effect. The soaping fastness of the comparative example group is basically at 2-3 levels, which is significantly lower than the embodiment group. This shows that the silk fabrics without modification are more prone to color change when performing the same soaping operation, and the combination between the dye and the fabric is not strong enough. Under the action of external forces such as washing, the dye is easily separated from the fabric, resulting in a poor dyeing effect of the fabric, which once again highlights the positive role of the modification process in improving color fastness.

[0080] The color fastness to friction is divided into dry friction and wet friction fastness, which reflects the color transfer of the fabric during the friction process. The dry friction color fastness of the embodiment group is mostly at the level of 3 to 4. Although there are small fluctuations between the embodiments, the overall performance is good, indicating that in daily dry friction scenes, the silk fabrics treated with modification can better maintain the dye adhesion, are not prone to fading, and the bonding force between the fabric and the dye can withstand a certain degree of friction test. The dry friction color fastness of the comparative group is mostly level 3, which is slightly inferior to the samples with better performance in the embodiment group, but the gap is not particularly large, reflecting that the silk fabrics without modification also have a certain color retention ability under dry friction, but are still not as good as the modified fabrics. The wet friction color fastness of the embodiment group is in the range of 3 to 4-5 levels, which is better than the dry friction color fastness as a whole. This shows that even when the fabric is in a wet state, the silk fabrics treated with modification can still better maintain the combination of the dye and the fabric, making the color stable, reflecting the advantages of the modification treatment for improving the color fastness of the fabric in a complex environment. The wet rubbing color fastness of the comparative group is basically at level 2-3 or level 3, which is significantly lower than that of the embodiment group, which means that the dye of the unmodified silk fabric is more likely to fall off when rubbed in wet state, and the color stability is poor, which makes it difficult to meet the requirements of high-quality dyed fabrics.

[0081] Through the comparative analysis of different performance indicators such as apparent color depth (K / S value) and soap fastness, color fastness to rubbing, it can be clearly seen that the silk fabric modified with dimethyldiallylammonium chloride (DADMAC) and glycidyl methacrylate (GMA) has significantly improved both the apparent effect and color fastness of dyeing after dyeing with reactive dyes compared to the untreated silk fabric. The modification treatment effectively enhances the interaction between silk fabric and reactive dyes, which not only makes the color of the fabric more intense after dyeing, but also greatly improves the ability of the fabric to maintain color stability during subsequent use. This provides strong data support for the optimization of silk fabric dyeing process and the development of high-quality silk dyeing products, and has important practical application value.

[0082] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A method for dyeing silk fabric with salt-free and alkali-free reactive dyes, characterized in that: The following steps are involved: S1. Pretreatment of silk fabric: Soap-wash the silk fabric and dry it for later use; S2, modification treatment of silk fabric: soak the silk fabric treated by S1 in a finishing agent at room temperature, take it out and dry it; the finishing agent is composed of: 2-10wt% dimethyldiallylammonium chloride, 2-10wt% glycidyl methacrylate, 0.8-1.2wt% initiator, 0.4-0.6wt% catalyst, and the balance deionized water; S3. Dyeing with reactive dyes: soak the silk fabric treated with S1 in water to fully wet it, then put it into the prepared reactive dye solution for dyeing, double immersion and double rolling, and finally bake it at 50-80°C until it is dry.

2. The dyeing method according to claim 1, characterized in that In S2, the initiator is ammonium persulfate.

3. The dyeing method according to claim 1, characterized in that In S2, the catalyst is tetramethylethylenediamine.

4. The dyeing method according to claim 1, characterized in that In S2, the soaking time at room temperature is 1-5 hours.

5. The dyeing method according to claim 1, characterized in that In S3, the dyeing temperature is 50-65°C and the bath ratio is 1:10-1:

15.

6. The dyeing method according to claim 1, characterized in that In S3, the dipping time of the double dipping and double rolling is 5 minutes, and the dipping and rolling liquid rate is 70-80%.

7. The dyeing method according to claim 1, characterized in that In S2, the silk fabric treated in S1 is immersed in the finishing agent at room temperature. The specific operation is: add dimethyldiallylammonium chloride and glycidyl methacrylate into deionized water, stir and mix, add initiator, then immerse the silk fabric therein, add catalyst, and immerse at room temperature.

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