TWI783626B - Auxiliary for dyeing, its manufacturing method and applied dyeing process - Google Patents

Abstract

The present invention provides a kind of auxiliary agent for dyeing and its manufacturing method as well as the applied dyeing process. Using dextran and citric acid as raw materials, the dextran surfactant is synthesized, and the dye in the dyeing and finishing wastewater is synthesized by using the agglutination property of the auxiliary agent. Catch and bring it into the cellulose fabric, in order to increase the dyeing rate of the fabric during the dyeing process and reduce the dye residue rate in the subsequent wastewater.

Description

Auxiliary for dyeing, its manufacturing method and applied dyeing process

The present invention belongs to the field of dyeing auxiliaries, and in particular relates to a dyeing auxiliaries capable of improving the dyeing rate during dyeing and reducing the dye residue rate in subsequent wastewater, its manufacturing method and the applied dyeing process.

According to general dyeing and finishing process can not be separated from fiber, machinery, dyes and water, in order to make full use of dyeing and finishing process, to successfully overcome the difficulties and reduce processing losses, it is necessary to use various chemicals to achieve for this purpose. However, with the improvement of consumers' quality requirements and the rapid development of new dyeing and finishing technologies, the requirements for reducing dyeing and finishing costs, saving energy, and automating operations are increasingly urgent. The development of new dyeing and finishing auxiliaries has emerged as the times require. It has contributed a lot to the progress and development of the dyeing and finishing industry. In the past, the anionic surfactants and cationic surfactants commonly used in dyeing and finishing factories often have disadvantages such as agglutination, precipitation, high residual content, strange smell, difficult storage, and effective use when used in large quantities. Therefore, the development of new surfactants is one of the main methods to enhance the competitiveness of the dyeing and finishing industry in the future. Especially in the dyeing process, the lack of appropriate auxiliaries often causes defects such as poor coloring rate, poor fastness, and uneven color.

In view of this, the present inventor feels that it is not perfect and exhausts its mental pains to study, and with its accumulated experience in this industry for many years, and then provides a kind of dyeing auxiliary agent and its manufacturing method and applied dyeing process, with a view to The deficiency of the above-mentioned prior art can be improved.

Therefore, one object of the present invention is to provide a dyeing auxiliary agent, its manufacturing method and the applied dyeing process, so as to increase the dyeing rate of the cloth and reduce the dye residue rate in the subsequent wastewater generated during the dyeing process.

，其中，n大於1。 In order to achieve the above-mentioned purpose, the auxiliary agent for dyeing of the present invention is used to improve the color uptake rate during dyeing and reduce the residual dye rate of the subsequent wastewater. It is characterized in that: the chemical structure of the auxiliary agent for dyeing is:

, where n is greater than 1.

，其中，n大於1。 Moreover, the present invention also provides a method for preparing dyeing auxiliaries, which includes the following steps: (A) putting dextran and citric acid in a reaction tank with a molar ratio of 1:1 to react, and reacting under high temperature and acidic conditions generate esterification dehydration reaction; and (B) add sodium hydroxide to make the pH in the reaction tank at 8-11, raise the temperature to carry out the reaction, and remove excess water to obtain a dyeing auxiliary. Wherein, the chemical structure of the auxiliary agent for dyeing is

, where n is greater than 1.

Preferably, the present invention further comprises the following steps: (C) adjusting the pH of the auxiliary agent for dyeing in step B to neutral with HCl, and then using extraction filtration to remove by-products while removing unreacted substances, and then The solvent was removed by distillation under reduced pressure to obtain the high-purity dyeing auxiliary.

Preferably, the concentration of sodium hydroxide is 0.1N.

，其中，n 大於1。 In addition, the present invention also provides a dyeing process using dyeing auxiliary to improve the color uptake, which includes the following steps: (1) adding dye and a dyeing auxiliary into the steel cylinder; (2) putting a fiber fabric into the steel cylinder and (3) taking out the fiber fabric and washing and soaping it with water, then drying it naturally. Wherein, the chemical structure of the auxiliary agent for dyeing is

, where n is greater than 1.

Preferably, the fiber fabric is cotton fabric.

In this way, the dyeing auxiliaries provided by the present invention can greatly reduce the content of dye compounds in the wastewater after dyeing, thereby reducing the pollution after wastewater discharge, and the above-mentioned dyeing process is also improved due to the addition of the dyeing auxiliaries. It can improve the dyeing rate of the fabric while reducing the ratio of dye compounds in the wastewater generated after the process.

Figure 1 is an experimental data diagram of whether the dyeing auxiliaries have the characteristics of the auxiliaries.

Fig. 2 is an experimental data diagram of the pH buffering ability of dyeing auxiliaries.

Figure 3 is the data chart of the interaction between dyeing auxiliaries and C.I.Direct Orange 39.

Figure 4 is the data chart of the interaction between dyeing auxiliaries and C.I.Direct Red 83.

Figure 5 is the data chart of the interaction between dyeing auxiliaries and C.I.Direct Blue 86.

Fig. 6 is an experimental data diagram of the dyeing rate of cotton fabrics by dyeing auxiliaries at different dyeing times.

Fig. 7 is an experimental data diagram of the absorbance of the raffinate after dyeing cotton fabrics with dyeing auxiliaries at different dyeing times.

The 8th figure, it is the experimental data figure of different dyestuffs to dyeing auxiliaries to the color rate of cotton fabric.

In order to enable those skilled in the art to clearly understand the content of the present invention, the following descriptions are provided together with the drawings for your reference.

，其中，n大於1。並且，以下係以Dextran-CA 代指該染色用助劑。 In this example, a dyeing auxiliary agent provided by the present invention is produced by the following method: first, dextran and citric acid are placed in a reaction tank with a molar ratio of 1:1 to react, and Under acidic conditions, esterification and dehydration reactions are generated, and sodium hydroxide is added to make the pH in the reaction tank between 8 and 11. Then, the temperature is raised to carry out the reaction, and excess water is removed to obtain a dyeing auxiliary. At this time, the chemical structure of the auxiliary agent for dyeing is

, where n is greater than 1. And, hereinafter, Dextran-CA is used to refer to the auxiliary agent for dyeing.

After the process is completed, follow-up treatment can also be carried out to purify the compound. Adjust the pH of the dyeing auxiliary in step B to neutral with HCl, and then use extraction and filtration to remove by-products and remove unreacted substances , and then distilled under reduced pressure to remove the solvent to obtain high-purity dyeing auxiliaries, and adjust them to different concentrations according to different dyeing situations.

Figure 1 is a diagram for data analysis of the dyeing auxiliaries to confirm whether the dyeing auxiliaries have the characteristics of the auxiliaries. The X-axis is the concentration of the auxiliaries, and the Y-axis is the surface tension.

Generally, when pure water is at 25°C, the surface tension is about 72.4dyne/cm. When additives are added, the surface tension will decrease with the increase of its concentration. It can be seen in Figure 1 that the molecular weight of citric acid at the hydrophilic base increases increase, the better the hydrophilicity, and the decrease in the surface tension value gradually becomes smaller. This is because when the (-CH ₃ COO) in the citric acid molecular chain increases, the oxygen atoms in the structure and the water molecules are likely to form hydrogen bonds, resulting in product water increased hydrophilicity. It can also be seen from the figure that the dyeing auxiliaries have a very large inward attraction to water molecules, and the hydrophobic groups of the surfactants are difficult to arrange in a tight and regular adsorption on the water surface, so the reduction in surface tension becomes smaller. Therefore, it can be seen that the present invention The dyeing auxiliaries provided are relatively stable.

Next, discuss the foamability of the dyeing auxiliary agent provided in this case. Pure water does not foam, but when the solution contains a surfactant, the solution is stirred, and air enters the solution to form bubbles. At this time, the additive will be adsorbed on the interface between the liquid and gas phases to form an elastic film, so Foam will occur if gas is present in the liquid. In the dyeing process, it is often necessary to add surfactants to improve the quality of product dyeing. However, during the dyeing process, the gas is often brought into the dye solution due to the rotation of the machine to generate foam. Therefore, in the dyeing and finishing process, the surfactant used Must have the nature of low foaming. Surfactants help foaming because they reduce surface tension. Generally speaking, the foaming value of anionic surfactants is about 20 cm, and that of nonionic surfactants is about 10 cm.

The main reason for low foaming is that the structure of a series of products has more steric barriers, resulting in irregular arrangement of hydrophilic groups and hydrophobic groups in the interface, making the long chains of hydrophobic groups on the interface unable to be symmetrical Arranged side by side, and because the stable existence of foam mainly depends on the attractive force between the long chains of hydrophobic groups to provide a certain strength to the liquid film, in this case the long chains of hydrophobic groups cannot give sufficient strength to the liquid film. Therefore, it is not easy to form a stable elastic film at the interface, so when the bubbles are generated, they will quickly burst, so the foaming property is low.

Excessive foam will hinder the contact between the dye solution and the fiber, thus causing problems such as uneven dyeing. However, because the dyeing auxiliary retains the hydrophilic properties of dextran, it will not produce foam during dyeing and will not cause problems. It will cause non-oxidation of the river due to the persistent foam, causing a burden on the environment.

Please refer to Table 1 and Table 2 below, which are the acid and alkali resistance test results of the dyeing auxiliaries.

It can be seen from Table 1 that after adding NaOH to each synthesized product, and the concentration ranges from 10% to 40% aqueous solution, it will be a homogeneous phase after stirring and standing for 10 minutes, which means that the dyeing auxiliaries will not destroy its color under alkaline conditions. Molecular structure; as can be seen from Table 2, when the concentration of HCl is added from 10% to 37% aqueous solution, it will be a homogeneous phase after stirring and standing for 10 minutes, indicating that the dyeing auxiliary has good acid resistance.

Please refer to Fig. 2, which is an experimental data diagram of the pH buffering ability of the dyeing auxiliaries. As shown in the figure, in the fiber dyeing process, it is often necessary to add different acid-base agents to increase various properties of the fabric, such as softness, hand feeling, color uniformity, etc. Due to the difference in the acidity and alkalinity of the added agents, the pH of the processing procedure changes greatly, resulting in differences in product properties and increasing costs. Therefore, it must have pH buffering ability to maintain a relatively constant pH value. The pH value of the dyeing auxiliaries is acidic, so the experiment is to adjust it to neutral as a test, and slowly drop 0.5N HCl to record the change of pH. After the pure water is dropped into 1mL of 0.5N HCl, the pH value drops from about 7 to about 4 sharply, which shows no buffering ability, but it has acceptable pH buffering ability for this dyeing auxiliaries. And for the product containing COOH group structure, when dissolved in water, it can combine with H ⁺ ions, so that the concentration of H ⁺ ions in the solution increases slowly, so it has a fair pH buffering ability.

In the dyeing process, the ideal situation is to make the dyed fabric fully absorb the dye, so that the finished product can be close to the original color of the dye, and also solve the problem of excessive color of the discharged wastewater, but it is often difficult to do it in actual operation on site. Achieved. Therefore, in this embodiment, the present invention provides a dyeing process that uses the above-mentioned dyeing auxiliary to increase the coloring rate and reduce the dye residue rate in wastewater, including the following steps: (1) adding dye and a Auxiliaries for dyeing; (2) putting a fiber fabric into a steel cylinder and sealing it before dyeing; and (3) taking out the fiber fabric and washing it with water and soap, and then drying it naturally. In the present embodiment, the fiber fabric to be dyed is cotton fiber. Among them, after the fiber fabric is put into a steel cylinder and sealed, it is heated and dyed from 30°C at a rate of 2°C per minute. Through this heating rate, the dyeing process can be made more stable and the color uptake rate can also be improved.

Please refer to Table 3 below, which is the ratio of COD to BOD ₅ of the dyeing auxiliaries.

As can be seen from the above table 3, the auxiliary agent for dyeing has a higher biodegradability (Biodegradability (%)) compared to the commercially available surfactant sodium dodecyl sulfate (Sodium dodecyl sulfate, SDS), and from the table It can also be known that the ratio of COD/BOD ₅ , COD/BOD ₅ <2.0, indicates that the biodegradability of the dyeing auxiliary is quite high, and it is suitable for biological treatment.

Figure 3 to Figure 5 are the data graphs of the interaction between dyeing auxiliaries and C.I.Direct Orange 39, C.I.Direct Red 83 and C.I.Direct Blue 86 respectively.

During the dyeing process, the surfactant and the dye have an affinity to interact and form a so-called complex. After the complex is formed, the absorption characteristics of the spectrum of the dye and the surfactant solution will be changed, thereby affecting the dyeing process. In order to understand the surfactant and dye solution As a mechanism for forming a complex, it is necessary to discuss the relationship between them. Generally, in the process of dyeing cotton fibers with direct dyes, the dyes are prone to agglomeration in the dyeing bath or in the pores inside the fibers. The absorbance of the dye concentration measured by the visible spectrometer is proportional to the amount of unassociated dye. Therefore, at a fixed dye concentration, self-agglutination of the dye will result in a decrease in absorbance.

The dye will form self-agglutination phenomenon in the dye bath. If the aggregation phenomenon is de-agglomerated by the addition of surfactants, the absorbance will decrease. The dye after de-aggregation has a lower affinity for fibers than agglutinated dyes, so it can be reduced. The effective dye concentration in the dye bath provides a retarding effect on the dyeing process; however, if a dye-surfactant complex is formed after the addition of a surfactant, the formation of such complexes or dye aggregates (aggregates) can reduce the dye bath. There is no agglomerated dye concentration in the medium, so the absorbance can be reduced, and the composite or dye aggregate aggregated in the dye bath or in the pores inside the fiber is more hydrophobic than the raw material, so it has a greater effect on cotton fibers than when the dye is alone. Affinity, so it can increase the effective dye concentration in the dye bath to provide a dyeing-accelerating effect on the dyeing process.

The synthesized dyeing auxiliaries were directly reacted with three dyes, C.I.Direct Orange 39, C.I.Direct Red 83 and C.I.Direct Blue 86, and UV U-3010 was used to measure the spectrum and the absorbance of the maximum absorption wavelength. It can be seen from the figure that adding the dyeing auxiliaries to the dye solution can reduce the absorbance, which will cause a shift in the UV maximum absorption wavelength (λ max) of the dye solution, which means that the dyeing auxiliaries and the dye have an affinity and will form a composite body. The dyeing auxiliaries combine with the hydrogen bond and van der Waals force of the dye to form a huge molecule in the early stage of dyeing, which reduces the absorbance, and the resulting complex is smaller than that of a single dye, which is conducive to diffusion and movement, thus causing dyeing acceleration.

Please continue to refer to Fig. 6 and Fig. 7, which are the experimental data diagrams of the dyeing rate of the dyeing auxiliaries on cotton fabrics at different dyeing times and the absorbance of the residual liquid after dyeing cotton fabrics at different dyeing times. The dyeing process generally includes three stages: adsorption, diffusion, and fixation. All three stages require certain Time to complete the dyeing process, as the dyeing time increases, the better the exhaustion rate of the fiber to the dye, but after a certain period of time, it will no longer increase to the maximum exhaustion rate, and it is known that the dyeing aid is the best for the fiber and the dye The staining time can be shortened considerably for staining procedures. It can be seen from Figure 6 that the dyeing auxiliaries have a dyeing-accelerating effect on fibers and direct dyes, and the highest dye exhaustion rate is obviously reached at 60 minutes; if it exceeds it, the coloring rate will be reduced; and from Figure 7 It can be seen that the time of 60 minutes has the lowest residual liquid absorbance, so 60 minutes of heat preservation is the best condition.

Please refer to Fig. 8, which is an experimental data diagram of the color ratio of different dyes to dyeing auxiliaries on cotton fabrics. CIDirect Blue 86, CIDirect Orange 39 and CIDirect Red 83 with three primary colors and different structures (all are linear structures with azo groups as the main body, and also contain sulfonic acid groups (-SO ₃ H) or sodium sulfonate (-SO ₃ Na) is a hydrophilic group, so it is an anionic dye with excellent water solubility) to dye cellulose fibers respectively to investigate the color uptake rate of the dyeing auxiliaries to other direct dyes. Figure 8 shows that the dyeing auxiliaries have obvious dyeing aid effects on other types of direct dyes, and can improve the coloring rate of cellulose fibers, showing that even under direct dyes with different structures, it can also help to dye cellulose. Fiber dyeing rate problem.

The following table 4 and table 5 are the experimental data of the water fastness and washing fastness of the dyeing auxiliary agent for dyeing cellulose fibers.

A: AATCC 107 B: ISO 105 E01

C: AATCC 61 1A D: ISO 105 C06 A2S

The results in Table 4 and Table 5 show that the washing fastness of the three dyes has a high degree of pollution to cotton fabrics, especially C.I.Direct Blue 86 has poor fastness to fading (level 2-3), because of the non-linear structure of the dye itself and the fiber Cotton and Nylon are the most polluted (grade 1-2) in terms of water fastness; except for the poor fastness of C.I.Direct Blue 86 in the sweat test, the other two dyes are both Has a good fastness rating. For the dyeing auxiliaries to dye cellulose fibers with direct dyes, although it helps to improve the color uptake of the fabric, but after dyeing, there is no post-processing and color fixing treatment, so the washing fastness and water fastness are slightly poor. If you want to get better dyeing fastness, you can try to use post-processing to fix the color to increase the dyeing fastness to washing and water.

In summary, the above experimental data show that adding the dyeing auxiliaries provided by the present invention during dyeing will increase the color uptake rate of cotton fabrics to direct dyes. And the present invention has the following advantages:

1. The dyeing auxiliary has good acid and alkali resistance, and the composite is not easily damaged by acid and alkali.

2. The auxiliary agent for dyeing has acceptable pH buffering capacity.

3. The auxiliary agent for dyeing has been tested for chemical oxygen demand in water and biochemical oxygen demand in water, and has high biodegradability, and is suitable for biological treatment.

4. The auxiliary agent for dyeing has dyeing effect on different types of direct dyes (C.I.Direct Orange 39, C.I.Direct Red 83, C.I.Direct Blue 86).

Therefore, the dyeing auxiliaries can indeed improve the dyeing rate of the cloth, and at the same time reduce the residual dye content in the wastewater produced afterwards, so as to avoid further pollution to the environment.

However, the above-mentioned ones are only preferred embodiments of the present invention, and are not used to limit the scope of the present invention; therefore, equivalent changes and modifications made without departing from the scope of the present invention should be covered by the present invention within the scope of the patent.

Claims (6)

A kind of auxiliary agent for dyeing, which is used to improve the coloring rate during dyeing, and reduce the dye residue rate in the subsequent waste water. It is characterized in that: the chemical structure of the auxiliary agent for dyeing is:

Wherein, n is greater than 1. A method for preparing dyeing auxiliaries, comprising the following steps: (A) placing dextran and citric acid in a reaction tank with a molar ratio of 1:1 to react, and generating esterification and dehydration reaction under high temperature and acidic conditions and (B) adding sodium hydroxide to make the pH in the reaction tank between 8 and 11, heating up to react, and removing excess water to obtain a dyeing auxiliary agent; wherein, the chemical structure of the dyeing auxiliary agent is for

Wherein, n is greater than 1. The method as described in claim 2, further comprising the following steps: (C) adjusting the pH of the dyeing auxiliary in step B to neutral with HCl, and then using extraction and filtration to remove by-products and remove unreacted substances , and then distilled under reduced pressure to remove the solvent to obtain the high-purity dyeing auxiliaries. The method as described in claim 3, wherein the concentration of sodium hydroxide is 0.1N. A dyeing process using dyeing auxiliary to improve the color uptake, comprising the following steps: (1) adding dye and a dyeing auxiliary into a steel cylinder; (2) putting a fiber fabric into the steel cylinder and sealing it for dyeing and (3) taking out the fiber fabric and washing it with water and soap, and then drying it naturally; wherein, the chemical structure of the auxiliary agent for dyeing is wherein, and n is greater than 1. The method according to claim 5, wherein the fiber fabric is cotton fabric.

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