A high fastness and high utilization rate dyeing method of reactive dye

Abstract

The application relates to a high-fastness and high-utilization-rate dyeing method of active dyes, which comprises the following steps: (1) padding and piling, dyeing and diffusion of the active dyes; (2) reducing the liquid content on the fiber by controlling the temperature; (3) comprehensively treating the low-liquid-content fabric by temperature and humidity, rapidly fixing the active dyes on the fiber by reaction; and (4) washing and drying. The application has the following advantages: the padding-piling-reducing-liquid-content can promote the sufficient diffusion of the dyes to the fiber interior, ensure that the dyes between the yarns and between the fibers are almost completely absorbed into the fiber interior, under the low-liquid-content, the comprehensive treatment by temperature and humidity can improve the fixing reaction efficiency and the final utilization rate of the dyes, and the active dyes can further diffuse to the fiber interior, and the hydrolysis side reaction of the active dyes can be effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of textile printing and dyeing, and specifically relates to a dyeing method with high fastness and high utilization rate of reactive dyes. Background Technology

[0002] Reactive dyes are the most commonly used dyes for dyeing cellulose fibers. However, due to the characteristics of their molecular structure, these dyes undergo a certain degree of hydrolysis during fixation, resulting in low utilization rates and poor dyeing quality. For commonly used dip-dyeing and pad-dyeing processes, improving the utilization rate of reactive dyes can not only reduce the difficulty of wastewater treatment but also further enhance the quality of the dyeing process.

[0003] In recent years, newly developed methods and processes to improve the utilization rate of reactive dyes include: organic solvent dyeing, supercritical CO2 dyeing, cold pad-batch dyeing, cationic modification of cotton fibers, low liquor ratio dyeing, and foam dyeing. Although these processes have improved dye utilization to some extent, certain problems still exist in industrial applications. These include solvent recovery and toxicity in organic solvent dyeing, the widespread availability of supercritical CO2 dyeing equipment, the uniformity of cationic modified dyeing, and the universality of low liquor ratio dyeing; as well as the reproducibility of foam dyeing and processing equipment issues. These problems, to some extent, restrict the application and development of these new technologies.

[0004] Reactive dyes exhibit rapid fixation and minimal hydrolysis at low liquid content, ensuring good utilization. Therefore, the application of reactive dyes with low liquid content has become a research focus. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dyeing method with high fastness and high utilization rate of reactive dyes. The method has a wide range of applications for reactive dyes, low cost, low equipment requirements, and simple operation.

[0006] This invention provides a dyeing method for high fastness and high utilization rate of reactive dyes, comprising the following steps:

[0007] (1) Immerse the textiles in a dyeing solution containing dyes and fixing agents, roll them evenly to remove moisture, and stack them at room temperature.

[0008] (2) Reduce the liquid content of the stacked textiles to 15%-40% under the condition that the surface temperature does not exceed 40°C.

[0009] (3) The textile with low liquid content is fixed under the combined effect of temperature and humidity, and finally soaped, washed with water and dried to obtain the dyed product.

[0010] The textiles in step (1) include one or more of the following: natural or regenerated cellulose fiber woven fabrics, skeins, cotton strips, loose fibers, knitted fabrics, and garments.

[0011] The dye in step (1) includes one or more of the following: divinyl sulfone type, bis(chlorotriazine) type, bis(fluorotriazine) type, monochlorotriazine monovinyl sulfone type, monofluorotriazine monovinyl sulfone type, divinyl sulfone monochlorotriazine, and divinyl sulfone monofluorotriazine reactive dyes; the amount of the dye used is 10-100 g / L.

[0012] The fixing agent in step (1) is one or more of sodium hydroxide, sodium carbonate, sodium silicate, disodium hydrogen phosphate, sodium acetate, ethylenediamine, triethanolamine, and sodium trichloroacetate; the concentration of the fixing agent is 5-40 g / L.

[0013] The stacking in step (1) is open stacking and does not need to be in a sealed environment; the stacking method includes one or more of the following: rolling stacking, circulating stacking in the dyeing machine, roller turning stacking, and shaking stacking.

[0014] The stacking temperature in step (1) is 15-35℃ and the stacking time is 60-360 min.

[0015] The methods for reducing the liquid content on textiles in step (2) include one or more of the following: centrifugation, cold air blowing, hot air blowing, drum drying, infrared radiation drying, and ultra-low liquid content rolling mill.

[0016] After reducing the liquid content of textiles, the fabrics do not need to be sealed and can be rolled and stacked.

[0017] The color fixing in step (3) is carried out in a steaming box, steaming machine or setting machine, without the need for sealing.

[0018] The synergistic effect of temperature and humidity in step (3) refers to the humidity being 80%-100% when the temperature is 90-120℃ and 5-50% when the temperature is 140-180℃.

[0019] The color-fixing time in step (3) is 0.5-8.5 min.

[0020] Beneficial effects

[0021] The present invention has the following advantages:

[0022] Padding-piling-reducing the liquid content promotes the full diffusion of dye into the fiber interior, ensuring that the dye is almost completely adsorbed into the fiber interior between yarns and fibers, thus ensuring efficient and uniform dye adsorption and high-efficiency color fixation. At low liquid content, the combined effects of humidity and temperature during reactive dye fixation can improve the dye fixation reaction efficiency and final utilization rate, and allow the reactive dye to diffuse further into the fiber interior, effectively reducing the hydrolysis side reaction of the reactive dye and ensuring the re-diffusion of dye within the fiber. This ensures the high uniformity of the final dyed product and guarantees dyeing quality, especially improving the wet rubbing fastness of dark-colored varieties by 1-2 grades. This method ensures less floating dye, uniform dyeing, and high dye utilization during the reactive dye dyeing process, resulting in textiles with high rubbing fastness. The dyeing process of this method is simple, requires no sealing operations, and is easy to produce and process. Detailed Implementation

[0023] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0024] Example 1

[0025] (1) Accurately weigh 20 pieces of pure cotton twill (21S*21S, 160g / m²) weighing 6.08g each. 2 ), numbered 1-20;

[0026] (2) Prepare a working solution of CI active black 5 (100g / L) and sodium carbonate (15g / L), stir until completely dissolved, and perform two dips and two rolls with a roll residue of 70%.

[0027] (4) Pile cotton fabrics No. 1-7 at room temperature (25℃) for 0, 60, 120, 180, 240, 300 and 360 min respectively; pile No. 8 cotton fabric for 24 h; and pile No. 9-20 cotton fabrics for 180 min.

[0028] (5) Allow the stacked cotton fabrics of grades 1-7 to air dry naturally until the liquid content is 30±2%. Allow cotton fabrics of grades 8-12 to air dry until the liquid content is 60%, 50%, 40%, 20%, and 10%, respectively. For grades 13-16, use centrifugal drying, infrared drying, forced-air drying oven, and drying drum drying methods to reduce the liquid content to 30%+2%, respectively. Then place them in a steam oven (100℃, 100% humidity, 450g / m³ steam). 3Steam for 6 minutes. Air dry naturally at 17-20°C until the liquid content is 30±2%. Then place in a tabletop setting machine, a small setting machine (140°C, 3 minutes), a forced-air drying oven (140°C, 3 minutes), or a steam oven (100°C, 100% humidity, 3 minutes).

[0029] (6) After color fixing, the cotton fabric is washed with cold water, soaped at 95℃ (standard detergent 2g / L, sodium carbonate 1g / L), washed with hot water at 60℃ (washing time is 10min for each), washed with running cold water, and dried to obtain the finished product.

[0030] Using a UV-1800PC spectrophotometer (Mapada, Shanghai), the fixation rate (F%) of reactive dyes was measured according to the standard GB / T 2391-2014 using the acid dissolution method. The dry and wet rubbing fastness of the dyed fabrics was determined according to the standard GB / T3920-2008. The fixation rate and dry and wet rubbing fastness of 20 samples are shown in the table below.

[0031] Serial Number Color fixation rate Dry friction fastness wet friction fastness 1 51.2％ 3 2-3 2 75.3％ 4 2-3 3 83.2％ 4 3 4 95.1％ 4 3-4 5 95.2％ 4 3-4 6 95.3％ 4 3-4 7 90.3％ 4 3 8 80.2％ 3-4 3 9 85.1 3-4 3 10 88.3％ 3-4 3 11 90.0 4 3 12 65.0％ 3 2-3 13 94.6％ 4 3-4 14 94.1％ 4 3-4 15 93.2％ 4 3-4 16 95.8％ 4 3-4 17 92.8％ 4 3-4 18 93.6％ 4 3 19 94.8％ 4 3-4 20 95.6％ 4 4

[0032] Example 2

[0033] (1) Accurately weigh 8g of pure cotton yarn (21s), pure cotton knitted fabric, loose cotton fiber, viscose woven fabric, Tencel woven fabric, and pure cotton Tencel interwoven woven fabric, numbered 21 to 26.

[0034] (2) Prepare a 50 g / L CI Reactive Red 3B impregnation working solution and add 10 g / L sodium carbonate. Stir until completely dissolved, then perform a two-dip and two-nip working solution with a roll residue of 70%.

[0035] (3) Stack at 30℃ for 120 minutes;

[0036] (4) Centrifuge the stacked textiles until the liquid content is 30%, and fix the color in a benchtop setting machine (140℃, 5min);

[0037] (5) After color fixing, the cotton fabric is washed with soap at 95℃ (standard detergent 2g / L, sodium carbonate 1g / L), washed with hot water at 60℃ (washing time is 10min), washed with running cold water, and dried to obtain the finished product.

[0038] Using a UV-1800PC spectrophotometer (Mapada, Shanghai), the fixation rate (F%) of reactive dyes was measured according to the following equation using the acid dissolution method: The dry and wet rubbing fastness of the dyed fabrics was determined according to standard GBT3920-2008. The corresponding fixation rates and dry and wet rubbing fastness of the samples are shown in the table below.

[0039] Serial Number Color fixation rate Dry friction fastness wet friction fastness 21 94.2％ 3 3-4 22 95.3％ 4 3-4 23 93.2％ 4 3-4 24 95.1％ 4 3-4 25 95.2％ 4 3-4 26 95.3％ 4 3-4

[0040] Example 3

[0041] (1) Accurately weigh 5 pieces of liquid ammonia mercerized cotton cloth weighing 1.08g each, and number them 27-31;

[0042] (2) Prepare padding working solutions of 50g / L L.I. Reactive Red 198 (M type), CI Reactive Blue 194 (M type), CI Reactive Red 120 (bis(monochlorotriazine) type), CI Reactive Black 5 (vinyl sulfone type), and CI Reactive Blue 250 (bis(vinyl sulfone) type) respectively, and add 10g / L sodium carbonate, stir for 2-3 minutes until completely dissolved;

[0043] (3) Set the roll pressure to 1.8 kg / cm. 2 The rotation speed is 4.6 revolutions / min. Cotton fabrics of No. 27-31 are respectively immersed in the above dye liquor, and then immersed and nibbled in the working liquor twice (immersion time 30s), with a pick-up rate of 70%.

[0044] (4) After padding, stack at 25°C for 120 min. After stacking, dry with infrared to 30% liquid content. Then fix in a setting machine at 120°C for 3 min.

[0045] (5) The hydrolysis of the dye was quantitatively analyzed in each process of stacking, reducing the liquid content and fixing using high performance liquid chromatography (HPLC). The hydrolysis of the dye is shown in the table below.

[0046]

[0047] As shown in the table, for the five different reactive dyes, almost no hydrolyzed dyes were generated during the stacking and liquid content reduction stages. This indicates that stacking does not affect the stability of the dyes during the dye diffusion process, and that reducing the liquid content of the fabric by infrared rapid drying is feasible. Under certain temperature and humidity conditions, the M-type reactive dyes have a higher amount of hydrolysis compared to the bis(chlorotriazine) and bis(ethylene sulfone) type reactive dyes, but at most, they only account for 4.55% of the total dye amount. Considering the hydrolysis of dyes at each stage, this process proves that it can effectively improve the color-fixing efficiency of reactive dyes, greatly reduce hydrolysis side reactions, and significantly improve dye utilization.

[0048] Example 4

[0049] (1) Accurately weigh 8 pieces of 1.08g liquid ammonia mercerized cotton cloth, numbered 32-37.

[0050] (2) Prepare padding working solutions of 25 g / L and 60 g / L CI Reactive Red 198 (bath ratio 1:20), add 10 g / L and 25 g / L sodium carbonate respectively, stir for 2-3 minutes until completely dissolved; set the roll pressure to 1.8 kg / cm. 2Rotation speed 4.6 revolutions / min, 32 and 33 cotton fabrics are impregnated with 25g / L working solution, 34 and 35 cotton fabrics are impregnated with 65g / L working solution, and the pick-up rate is 80%.

[0051] (4) After impregnation, No. 32 and No. 34 cotton fabrics were sealed and stacked at 25°C for 120 minutes. After stacking, they were naturally air-dried until 30% liquid content was achieved. Then, they were sealed again and placed in an electric heating drying oven for color fixation at 80°C for 40 minutes.

[0052] (5) After impregnation, No. 33 and No. 35 cotton fabrics were piled at 25°C for 120 minutes. After piled up, they were naturally air-dried until 30% liquid content was achieved. Then, they were fixed in a steam oven at 105°C and 80% humidity for 6 minutes.

[0053] (6) Dyeing process for cotton fabrics No. 36 and No. 37. Prepare dyeing solutions of 2% owf and 4% owf CI Reactive Red 198 respectively (liquor ratio 1:20). Place the conical flask containing the dyeing solution into a shaking water bath. When the dyeing solution temperature reaches the dyeing temperature (40℃), add the cotton fabric for dyeing for 60 min, and add sodium sulfate (60g / L) every 30 min. After the dyeing process is completed, adjust the heating rate of the water bath to 1℃ / min. When the dyeing solution temperature reaches the fixing temperature (90℃), add sodium carbonate (20g / L) for fixing for 60 min.

[0054] (7) After color fixing, the 32-37 cotton fabric is washed with cold water, soaped at 95℃ (standard detergent 2g / L, sodium carbonate 1g / L), washed with hot water at 60℃ (washing time is 10min for each), washed with running cold water, and dried to obtain the finished product.

[0055] Serial Number Color fixation rate Dry friction fastness wet friction fastness 32 90.2％ 3-4 3 33 95.3％ 4 4 34 89.0％ 3 3 35 95.1％ 4 3-4 36 83.6％ 3 2-3 37 78.5％ 3 2-3

[0056] As shown in the table above, in the pad-pile-pile-low liquid-volume fixing process, when the concentration of CI Reactive Red 198 is increased from 25 g / L to 60 g / L, the fixing rate does not change significantly. The increase in dye concentration does have a certain impact on dye diffusion, and pile-pile-sealed pile-sealed fixing achieves a better diffusion effect. Compared with conventional pad-dyeing processes and pad-pile-sealed pile-sealed fixing processes, the process of this invention not only improves the fixing rate but also enhances the quality of the dyed products, making it practically significant for improving the fixing rate of reactive dyes.

Claims

1. A dyeing method for high fastness and high utilization rate of reactive dyes, comprising the following steps: (1) Immerse the textile in a dye bath containing dye and fixing agent, roll out the water evenly, and stack at room temperature; wherein the fixing agent is one of sodium hydroxide, sodium carbonate, sodium silicate, disodium hydrogen phosphate, sodium acetate, ethylenediamine, triethanolamine, and sodium trichloroacetate; the stacking temperature is 15-35℃ and the stacking time is 120-360min; (2) After stacking, reduce the liquid content of the textiles to 20%-40% under the condition that the surface temperature does not exceed 40°C; (3) The textile with low liquid content is fixed under the synergistic effect of temperature and humidity, and finally soaped, washed with water and dried to obtain the dyed product; the color fixing does not require sealing; the synergistic effect of temperature and humidity means that when the temperature is 100-120℃, the humidity is 80%-100%; when the temperature is 140-180℃, the humidity is 5-50%; the color fixing time is 3-8.5min.

2. The method according to claim 1, characterized in that: The textiles in step (1) include one or more of the following: natural or regenerated cellulose fiber woven fabrics, skeins, cotton strips, loose fibers, knitted fabrics, and garments.

3. The method according to claim 1, characterized in that: The dye in step (1) includes one or more of the following: divinyl sulfone type, bis(chlorotriazine) type, bis(fluorotriazine) type, monochlorotriazine monovinyl sulfone type, monofluorotriazine monovinyl sulfone type, divinyl sulfone monochlorotriazine, and divinyl sulfone monofluorotriazine reactive dyes; the amount of the dye used is 10-100 g / L.

4. The method according to claim 1, characterized in that: The concentration of the color-fixing alkali agent in step (1) is 5-40 g / L.

5. The method according to claim 1, characterized in that: The stacking in step (1) is open stacking and does not need to be in a sealed environment; the stacking method includes one or more of the following: rolling stacking, circulating stacking in the dyeing machine, roller turning stacking, and shaking stacking.

6. The method according to claim 1, characterized in that: The methods for reducing the liquid content on textiles in step (2) include one or more of the following: centrifugation, cold air blowing, hot air blowing, drum drying, infrared radiation drying, and ultra-low liquid content rolling mill.

7. The method according to claim 1, characterized in that: The color fixing in step (3) is carried out in a steam oven, steaming machine or setting machine.

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