Dyeing auxiliaries, their manufacturing methods, and the dyeing processes in which they are applied

Abstract

This invention provides a dyeing auxiliary agent, its manufacturing method, and the dyeing process in which it is applied. Using gelatin, citric acid, epichlorohydrin, and sodium bisulfite as raw materials, a hydrolyzed gelatin derivative surfactant is synthesized through reaction. The surfactant utilizes the aggregation properties of the auxiliary agent to capture and carry the dye in the dyeing and finishing wastewater into the cellulosic fabric, thereby increasing the dyeing rate of the fabric and reducing the dye residue rate in the subsequent wastewater.

Description

Dyeing auxiliaries, their manufacturing methods, and the dyeing processes in which they are applied This invention belongs to the field of dyeing auxiliaries, and in particular relates to a dyeing auxiliary that can improve the color uptake rate during dyeing and reduce the dye residue rate in the wastewater generated subsequently, as well as its manufacturing method and the dyeing process in which it is applied. Note that in the textile industry, the dyeing and finishing process is a crucial step, determining the quality of the finished product. While treatment technologies and methods have advanced significantly with technological advancements, the treatment of high-color wastewater from dyeing and finishing remains one of the most challenging issues in today's environmentally conscious world. The main pollutants in this wastewater are the organic compounds from dyes. Discharge of these substances into rivers can cause significant ecological impacts. For the dyeing and finishing industry, to achieve economic efficiency, wastewater treatment methods often combine biological treatment and chemical coagulation processes. Currently, approximately 10,000 different dyes are used in industrial production, and there are even 7x10... 5 Various auxiliaries are produced worldwide. However, even with the use of existing auxiliaries to assist in the dyeing and finishing process, approximately 20-25% of the dye compounds still fail to adhere to the fabric and are discharged with the wastewater. Therefore, more effective auxiliaries are needed in the process to reduce the environmental damage caused by dyeing and finishing wastewater. In view of this, the inventor, feeling that the technology was not perfect, devoted himself to research and, based on his years of experience in the industry, has provided a dyeing auxiliary agent, its manufacturing method, and the dyeing process in which it is applied, in order to improve the shortcomings of the above-mentioned prior art. Therefore, one object of the present invention is to provide a dyeing auxiliary agent, a method for manufacturing the same, and a dyeing process in which the dyeing process is applied, so as to increase the dyeing rate of the fabric and reduce the dye residue rate in the wastewater generated subsequently. To achieve the above objectives, the dyeing auxiliary agent of the present invention is designed to improve the dyeing rate during dyeing and reduce the dye residue rate in the subsequent wastewater. The characteristic feature is that the general formula of the dyeing auxiliary agent is: And n is in the range of 10 to 100, while R 1. R 2 、 R The 3 series consists of alkyl groups. Furthermore, this invention also provides a method for preparing a dyeing auxiliary agent, comprising the following steps: (A) dissolving 0.1 mol of citric acid in water, then adding alcohol and placing it in a four-well reaction vessel and stirring for 30 minutes, while heating to 80°C during stirring to generate a first transition product and water; (B) adding 50 ml of 20% gelatin to the first transition product and heating to 80°C, reacting for 1-2 hours to generate a second transition product; (C) cooling the second transition product to room temperature, then adding 50 ml of a mixed solution of epichlorohydrin and sodium bisulfite, and stirring at a constant temperature of 60°C for 1-2 hours to generate the dyeing auxiliary agent, wherein the molar ratio of epichlorohydrin to sodium bisulfite is 1:1. The general formula of the dyeing auxiliary agent is: And n is in the range of 10 to 100, while R 1. R 2 、 R The 3 series consists of alkyl groups. Preferably, the present invention further includes the following steps: (D) dissolving the dyeing auxiliary agent in ethanol, filtering, and then removing the solvent by vacuum distillation to obtain the dyeing auxiliary agent in high purity. Furthermore, this invention provides a dyeing process that utilizes a dyeing auxiliary to improve the dyeing rate, comprising the following steps: (1) adding dye and a dyeing auxiliary to a steel cylinder; (2) placing a fiber fabric into the steel cylinder and sealing it for dyeing; and (3) removing the fiber fabric and subjecting it to washing and soaping, followed by natural drying. The general formula of the dyeing auxiliary is: And n is in the range of 10 to 100, while R 1. R 2 、 R The 3 series consists of alkyl groups. Ideally, the fiber fabric is placed in a sealed steel cylinder and then heated and dyed starting at 30°C at a rate of 2°C per minute. Ideally, the material of the fiber fabric is cotton fiber. In this way, the dyeing auxiliary agent provided by the present invention can significantly reduce the content of dye compounds in wastewater after dyeing, thereby reducing pollution after wastewater discharge. The dyeing process described above can also improve the fabric dyeing rate and reduce the proportion of dye compounds in the wastewater generated after the process by adding the dyeing auxiliary agent. To ensure that your review committee can clearly understand the contents of this invention, please refer to the following description and accompanying drawings. In this embodiment, the dyeing auxiliary agent provided by the present invention is prepared by the following method: First, 0.1 mol of citric acid is dissolved in water, then alcohol is added and placed in a four-well reaction vessel and stirred for 30 minutes. During stirring, the mixture is heated to 80°C to generate a first transition product and water. Next, 50 ml of 20% gelatin is added to the first transition product and heated to 80°C, reacting for 1-2 hours to generate a second transition product. Finally, after cooling the second transition product to room temperature, 50 ml of a mixed solution of epichlorohydrin and sodium bisulfite is added, and the mixture is stirred at a constant temperature of 60°C for 1-2 hours to generate the dyeing auxiliary agent, wherein the molar ratio of epichlorohydrin to sodium bisulfite is 1:1. At this point, the chemical structure of the dyeing auxiliary agent is as follows: And n is in the range of 10 to 100, while R 1. R 2 、 R The 3 series consists of alkyl groups. After the process is completed, further processing can be carried out to purify the synthesized product. The raw materials of the incomplete reaction are dissolved in ethanol and then filtered. The solvent and excess water are then removed by vacuum distillation to obtain a higher purity synthesized product, which can be prepared into different concentrations depending on the dyeing requirements. Figure 1 illustrates data analysis of the dyeing auxiliary to confirm whether it possesses the characteristics of an auxiliary. The X-axis represents the auxiliary concentration, and the Y-axis represents surface tension. Gelatin refers to hydrolyzed gelatin, and Gelatin-CA is the dyeing auxiliary of this invention. Pure water at 25°C has a surface tension of approximately 72.4 dyne / cm. When an auxiliary is added, the surface tension decreases as its concentration increases. Figure 1 shows that the surface tension decreases significantly after the addition of the dyeing auxiliary, and further decreases slightly as the concentration of the added auxiliary increases to a certain level. This indicates that the dyeing auxiliary possesses the characteristics of an auxiliary. This is because the addition of a surfactant to an aqueous solution reduces surface tension due to the arrangement of the hydrophilic groups of the surfactant remaining in the liquid while the hydrophobic groups protrude above the water surface. Furthermore, it can be seen from Figure 1 that the surface tension of the hydrolyzed gelatin derivative Gelatin-CA is lower than that of hydrolyzed gelatin. This helps the dye penetrate into the fiber. This is because the dyeing auxiliary has multiple hydrophilic groups, while the hydrophobic groups of the surfactant are difficult to adsorb and arrange in a tight and regular manner on the water surface. Therefore, the reduction in surface tension is smaller. Figure 2 is a schematic diagram illustrating the results of an experiment conducted to determine whether excessive foaming would occur after adding the dyeing auxiliary agent. Gelatin is hydrolyzed gelatin, and Gelatin-CA is the dyeing auxiliary agent of this invention. Pure water does not foam, but when a solution contains surfactants, the solution is stirred, and air enters the solution, forming bubbles. At this time, the auxiliary agent is adsorbed at the interface between the liquid and gas phases, forming an elastic film. Therefore, if gas is present in the liquid, foam will be generated. As can be seen from Figure 2, the foam height of the derivative Gelatin-CA is lower than that of gelatin, and the foam stability is also lower. The experiment shows that the foam of the derivative Gelatin-CA almost disappeared within five minutes of the measuring instrument being stopped, while the gelatin still had a foam height of 0.1 cm. This is beneficial for environmental protection and reducing the discharge of polluting wastewater. If the foam does not disappear, it will cause anoxidation of rivers and increase the burden on the environment. In the dyeing process, the ideal situation is for the dyed fabric to completely absorb the dye. This not only makes the finished product close to the original color of the dye but also solves the problem of excessively high color in the wastewater discharge. However, this is often difficult to achieve in actual on-site operation. Therefore, in this embodiment of the present invention, a dyeing process is provided that utilizes the above-mentioned dyeing auxiliary agent to improve the color uptake rate and reduce the dye residue rate in the wastewater. The process includes the following steps: (1) adding dye and a dyeing auxiliary agent to a steel cylinder; (2) placing a fiber fabric into the steel cylinder and sealing it for dyeing; and (3) removing the fiber fabric and washing it with water and soap, and then allowing it to dry naturally. In this embodiment, the fiber fabric used for dyeing is cotton fiber. After the fiber fabric is placed into the sealed steel cylinder, it is heated and dyed starting from 30°C at a rate of 2°C per minute. This heating rate makes the dyeing process more stable and improves the color uptake rate. Figures 3 to 6 are schematic diagrams showing the results of detecting the color uptake rate of cotton fabrics after the dyeing process for different auxiliary agent concentrations, heat preservation times, dye concentrations, and dye types. Gelatin refers to hydrolyzed gelatin, Gelatin-CA is the dyeing auxiliary agent of this invention, and Blank represents the control group without the addition of auxiliary agents. As can be observed from Figure 3, the coloring rate increases with the increase of the concentration of the auxiliary agent. A high coloring rate can be obtained when the concentration of its derivative Gelatin-CA reaches 10 g / L. When the concentration is further increased, the coloring rate does not increase significantly. Therefore, the concentration of the derivative Gelatin-CA should be 10 g / L to obtain a high coloring rate. The dyeing process generally includes three stages: adsorption, diffusion, and fixation. Each of these stages requires a certain amount of time to complete the dyeing process. As shown in Figure 4, the dyeing rate of hydrolyzed gelatin and its derivative Gelatin-CA increases with increasing holding time. Compared to samples without additives and those with added hydrolyzed gelatin, the addition of Gelatin-CA significantly improves the dyeing rate of cotton fabrics. Gelatin-CA exhibits the highest dyeing rate at 60 minutes; further increases in holding time slightly decrease the dyeing rate. Therefore, a holding time of 60 minutes is optimal; excessive holding time only increases dyeing costs and wastes power. To achieve a darker color in fabric, the dye concentration must be increased; therefore, knowing the fabric's maximum dye absorption value is crucial. Figure 5 shows that as the dye concentration increases, the dye uptake of cotton fabric also increases. However, when the dye concentration reaches 1%, the uptake only slightly increases. Therefore, the optimal dye concentration for cotton fabric is 1%. Furthermore, using the derivative Gelatin-CA as a dyeing auxiliary agent results in a higher uptake of cotton fabric compared to cotton fabrics treated with hydrolyzed gelatin or without any additives. Figure 6 compares the color uptake of cotton fabrics with different dyes when gelatin and its derivative Gelatin-CA are added to the dye bath. Figure 6 shows that Gelatin-CA exhibits high color uptake on cotton fabrics with all direct dyes, showing a significant difference compared to the gelatin and no-additive groups. This demonstrates that Gelatin-CA effectively improves the color uptake of cotton fabrics regardless of the color. In summary, the experimental data above demonstrate that adding the dyeing auxiliary agent provided by this invention during dyeing increases the dye uptake rate of direct dyes on cotton fabrics. It also offers the following advantages or effects: 1. To achieve a high dye uptake rate when using the hydrolyzed gelatin derivative Gelatin-CA as an auxiliary agent for dyeing cotton fabrics, the optimal conditions are an auxiliary agent concentration of 10 g / L and a dyeing holding time of 60 minutes; it also has a dyeing aid effect on various colors of direct dyes. 2. Using the hydrolyzed gelatin derivative Gelatin-CA as a dyeing and finishing auxiliary agent reduces the difficulty of treating wastewater after dyeing, and this auxiliary agent is biodegradable and environmentally friendly. Therefore, this dyeing auxiliary agent can indeed improve the dye uptake rate of fabrics, while also reducing the residual dye content in the wastewater generated subsequently, thus avoiding further environmental pollution. However, the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Therefore, any equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered within the patent scope of the present invention. Figure 1 shows experimental data on whether dyeing auxiliaries possess the characteristics of auxiliaries. Figure 2 shows experimental data on whether excessive foaming occurs after applying dyeing auxiliaries. Figure 3 shows experimental data on the color uptake rate of dyeing auxiliaries on cotton fabrics at different concentrations. Figure 4 shows experimental data on the color uptake rate of dyeing auxiliaries on cotton fabrics at different heat treatment times. Figure 5 shows experimental data on the color uptake rate of dyeing auxiliaries on cotton fabrics at different dye concentrations. Figure 6 shows experimental data on the color uptake rate of dyeing auxiliaries on cotton fabrics with different dyes.

Claims

1. A dyeing auxiliary agent, used to improve the dyeing rate and reduce the dye residue rate in the subsequent wastewater, characterized in that: the general formula of the dyeing auxiliary agent is: And n is in the range of 10 to 100, while R 1、R 2 、 R The 3 series consists of alkyl groups. A method for preparing a dyeing auxiliary includes the following steps: (A) Dissolving 0.1 mol of citric acid in water, then adding alcohol and placing it in a four-well reaction vessel, stirring for 30 minutes, and heating to 80°C during stirring to generate a first transition product and water; (B) Adding 50 ml of 20% gelatin to the first transition product and heating to 80°C, reacting for 1-2 hours to generate a second transition product; (C) Cooling the second transition product to room temperature, then adding 50 ml of a mixed solution of epichlorohydrin and sodium bisulfite, and stirring at a constant temperature of 60°C for 1-2 hours to generate the dyeing auxiliary. The molar ratio of epichlorohydrin to sodium bisulfite is 1:1, and the general formula of this staining auxiliary is: And n is in the range of 10 to 100, while R 1、R 2、R The 3 series consists of alkyl groups. The method described in claim 2 further includes the following steps: (D) dissolving the dyeing auxiliary in ethanol, filtering, and then removing the solvent by vacuum distillation to obtain the dyeing auxiliary in high purity. A dyeing process utilizing a dyeing auxiliary to improve the dyeing rate includes the following steps: (1) adding dye and a dyeing auxiliary to a steel cylinder; (2) placing a fiber fabric into the steel cylinder and sealing it for dyeing; and (3) removing the fiber fabric and subjecting it to washing with water and soaping, followed by natural drying; wherein, The general formula for this dyeing auxiliary is: And n is in the range of 10 to 100, while R 1、R 2 、 R The 3 series consists of alkyl groups. The dyeing process as described in claim 4, wherein, After the fiber fabric is placed in a sealed steel cylinder, it is heated and dyed starting at 30°C at a rate of 2°C per minute. The dyeing process as described in claim 5, wherein, The material of this fiber fabric is cotton fiber.

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