Dyeing method for improving dyeing reproducibility of cellulosic fibers

Abstract

The invention relates to the technical field of textile fabrics, and discloses a dyeing method for improving dyeing reproducibility of cellulosic fibers, which comprises the following steps: 1) preparing a sodium acetate-acetic acid buffer solution, a reactive dye and substitute alkali into a dye solution with pH of 6.5-7.5; and 2) immersing cellulose fibers into the dye liquor in the step 1), sequentially dyeing at 25-40 DEG C for 8-12 minutes, heating to 60-80 DEG C, carrying out heat preservation dyeing for 20-40 minutes, and cooling to 40 DEG C or below. A sodium acetate / acetic acid / substituted alkali mixed system is adopted, electrolyte and alkali do not need to be added in batches in the subsequent dyeing process, the operation frequency of the dyeing process is reduced, and the dyeing reproducibility of dyed objects in different batches is improved.

Description

Technical Field

[0001] This invention relates to the field of textile fabric technology, and specifically to a dyeing method for improving the reproducibility of cellulose fiber dyeing. Background Technology

[0002] Reactive dyes are diverse in type and color selectivity. Their active groups allow them to form covalent bonds with cellulose fibers, resulting in excellent wash fastness and making them a commonly used dye in textile dyeing. Reactive dyes are readily soluble in water, primarily due to the presence of anionic groups in their molecules. However, in water, the hydroxyl groups on cellulose fibers dissociate into anions. Therefore, during immersion dyeing, there is a repulsive force between the reactive dye and the cellulose fiber, leading to low dyeing efficiency and a low dyeing exhaustion rate. To address this, electrolytes, such as sodium chloride and sodium sulfate, are typically added to the dye bath to increase the dyeing exhaustion rate, maximizing dye adsorption onto the dyed material. After the reactive dye has adsorbed onto the cellulose dye, an alkali, such as sodium carbonate and sodium hydroxide, is added to activate the reactive groups in the dye and accelerate the dissociation of hydroxyl groups (-OH) on the cellulose fibers into oxygen anions (-O). - This allows reactive dyes to react more efficiently with cellulose fibers, producing covalent bonds and fixing the dye onto the cellulose fiber dyed fabric.

[0003] In reactive dyeing, not only is it necessary for the dye to adhere firmly to the fabric, but also for the color to be uniform in each dyeing cycle, avoiding quality issues such as uneven coloring or spots. Therefore, in the traditional reactive dyeing process for cellulose fibers, dyeing is performed at room temperature without electrolytes for a period of time before adding the electrolyte in several batches to the dye bath. This allows the dye to gradually adhere to the fabric, achieving uniform dyeing. Adding the electrolyte in stages avoids uneven dyeing caused by a sudden increase in electrolyte concentration in the dye bath when added all at once. Similarly, in alkali-fixing processes, the alkali must be added in batches to prevent a sudden increase in the alkalinity of the surrounding dye bath, which could cause the reactive dye, not yet evenly distributed within the fiber, to react with the cellulose fiber, resulting in uneven dyeing.

[0004] The dyeing process of reactive dyes and cellulose fibers is complex. Multiple additions of dyes are required during the dyeing process, and the order of addition cannot be changed. Even slight differences in operation will result in uneven dyeing and color differences in the same type of fabric dyed in different batches. The dyeing reproducibility is poor and cannot meet production requirements. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of complex process flow and poor dyeing reproducibility in the dyeing of cellulose fibers with reactive dyes in the existing technology, and to provide a dyeing method that improves the dyeing reproducibility of cellulose fibers. The method dissolves reactive dyes in a mixed solution of sodium acetate / acetic acid / alkaline substitute to prepare the dye for dyeing. In subsequent dyeing processes, there is no need to add electrolytes and alkalis in batches, which reduces the number of operations in the dyeing process and thus improves the dyeing reproducibility of different batches of dyed materials.

[0006] To achieve the above objectives, the present invention provides a dyeing method for improving the reproducibility of cellulose fiber dyeing, the method comprising: 1) Prepare a dyeing solution with a pH of 6.5~7.5 by mixing sodium acetate-acetic acid buffer solution, reactive dye, and substitute alkali; 2) Immerse the cellulose fibers in the dye solution of step 1), and dye them at 25~40℃ for 8~12 minutes, heat them to 60~80℃ and keep them at that temperature for 20~40 minutes, and then cool them down to below 40℃.

[0007] Preferably, in step 1), the concentration of the sodium acetate-acetic acid buffer solution is 100~140 g / L.

[0008] Preferably, in step 1), the amount of the reactive dye in the dyeing solution is 1~5% (omf).

[0009] Preferably, in step 1), the reactive dye is at least one of Reactive Red 195, Reactive Yellow 145, and Reactive Blue 194.

[0010] Preferably, in step 1), the concentration of the substitute alkali in the dye solution is 4~6 g / L.

[0011] Preferably, in step 1), the substitute alkali includes a basic alkali agent, a buffer agent, and an auxiliary agent.

[0012] Preferably, the basic alkaline agent is at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0013] Preferably, the buffer is at least one of sodium silicate, triethanolamine, and sodium polyacrylate.

[0014] Preferably, the auxiliary agent is at least one of a dispersant, a chelating agent, and a leveling agent.

[0015] Preferably, in step 2), the ratio of the cellulose fiber to the dye liquor is 1:10~20.

[0016] Preferably, in step 2), the heating rate is 2.5~3.5℃ / min.

[0017] Preferably, in step 2), the cooling rate is 4.5~5.5℃ / min.

[0018] Preferably, the cellulose fiber is at least one of cotton fiber, linen fiber, and viscose fiber.

[0019] Compared with the prior art, the present invention has the following advantages: 1) This invention employs a sodium acetate / acetic acid / alkaline substitute mixed system. At room temperature, reactive dyes are dissolved in this mixed solution to prepare the dye for dyeing. Subsequent dyeing processes do not require the addition of electrolytes and alkalis in batches, reducing the number of dyeing operations and thus improving the reproducibility of dyeing different batches. Simultaneously, the sodium acetate contained in the discharged wastewater can serve as an effective carbon source, improving wastewater treatment efficiency.

[0020] 2) This invention uses a sodium acetate / acetic acid mixed solution as a pH buffer, which can not only precisely control the pH value to achieve the best dyeing effect, but also replace the use of electrolytes to improve the dyeing exhaustion rate.

[0021] 3) This invention uses a substitute alkali to replace the conventional alkali (sodium carbonate and sodium hydroxide). This not only eliminates the need to add alkali in batches during the subsequent dyeing and fixing process, but also enhances the ability to control the pH value during the dyeing process due to the synergistic effect of various alkaline compounds in the substitute alkali, ensuring uniform and continuous dyeing.

[0022] 4) When dyeing at 25-40℃, the dye bath containing the sodium acetate / acetic acid / alkaline substitute mixture is weakly acidic or neutral. Sodium acetate / acetic acid acts like an electrolyte, slowly releasing sodium ions to promote the slow adsorption of dye by cellulose fibers and its diffusion throughout the dyed material until uniform adsorption occurs. During heating to 60-80℃, the sodium acetate / acetic acid / alkaline substitute mixture begins to slowly release alkaline substances, making the dye bath alkaline and gradually promoting the reaction between the reactive dye and cellulose fibers, thus fixing the dye. Detailed Implementation

[0023] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0026] The dyeing method for improving the reproducibility of cellulose fiber dyeing according to the present invention includes: 1) Prepare a dyeing solution with a pH of 6.5~7.5 by mixing sodium acetate-acetic acid buffer solution, reactive dye, and substitute alkali; 2) Immerse the cellulose fibers in the dye solution of step 1), and dye them at 25~40℃ for 8~12 minutes, heat them to 60~80℃ and keep them at that temperature for 20~40 minutes, and then cool them down to below 40℃.

[0027] In step 1) above, the preparation method of the sodium acetate-acetic acid buffer solution is a conventional preparation method in the art, specifically, it can be prepared by mixing sodium acetate trihydrate, glacial acetic acid, and deionized water evenly. In the above preparation process, sodium acetate trihydrate can also be replaced with anhydrous sodium acetate, and the purity of glacial acetic acid can be selected as ≥99%.

[0028] In this invention, sodium acetate-acetic acid buffer solution is used instead of traditional electrolytes for dyeing. This not only simplifies the dyeing process and avoids the need to add electrolytes in batches during subsequent dyeing, but also stabilizes the pH value of the dye solution, ensuring uniform and continuous dyeing.

[0029] The concentration of the sodium acetate-acetic acid buffer solution described in this invention can be 100-140 g / L, preferably 110-130 g / L, meaning that the total mass of acetic acid and sodium acetate in each liter of buffer solution is between 100-140 g, preferably between 110-130 g. The concentration of the sodium acetate-acetic acid buffer solution reflects the total content of the buffer pair in the buffer solution and directly affects the buffer solution's ability to resist pH changes. Within the above concentration range, the buffer solution has a large buffering capacity, resulting in a slow pH change during the release of the substitute alkali in the subsequent dyeing process. This avoids a sudden increase in alkalinity in the dye bath, which could cause reactive dyes that have not yet been evenly distributed within the fibers to react prematurely with the cellulose fibers, ultimately leading to uneven dyeing.

[0030] In step 1) above, the amount of reactive dye in the dyeing solution can be 1-5% (omf), preferably 1.5-3% (omf). In this invention, the amount of reactive dye added is determined based on the mass of the dyed material, i.e., cellulose fiber, and the proportion of reactive dye is precisely controlled according to the actual weight of the cellulose fiber. In this invention, the amount of reactive dye required to be added per 1000g of cellulose fiber can be 10-50g, preferably 15-30g.

[0031] In this invention, the applicable reactive dye can be at least one of Reactive Red 195, Reactive Yellow 145, and Reactive Blue 194. The aforementioned reactive dyes were purchased from Shanghai Jiaying Chemical Co., Ltd.

[0032] In this invention, a substitute alkali is used instead of the traditional alkali agent. This not only simplifies the dyeing process and avoids the need to add alkali agents in batches during subsequent dyeing, but also allows the substitute alkali to be released slowly during the heating and dyeing process. Only after the dye is evenly adsorbed onto the cellulose fibers does it gradually promote the reaction between the reactive dye and the cellulose fibers, thus fixing the dye and avoiding uneven dyeing caused by a sudden increase in alkalinity in the dye bath.

[0033] The substitute alkali described in this invention is an alkaline auxiliary agent composed of multiple weakly alkaline compounds, replacing traditional strong alkalis. Through a compounding process, it retains the alkaline function of traditional alkalis while offering milder performance and greater controllability. Typically, the substitute alkali includes a base alkali, a buffer, and auxiliary agents. The base alkali is the core substance providing the alkaline environment and can be at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The buffer is a substance that maintains pH stability and optimizes dyeing effects and can be at least one of sodium silicate, triethanolamine, and sodium polyacrylate. The auxiliary agents are substances that improve process compatibility and environmental performance and can be at least one of reactive dye dispersants, chelating agents, and leveling agents. The performance of the substitute alkali depends on the synergistic effect between its components. The selection of each component in the substitute alkali enhances its alkaline stability and buffering capacity, preventing precipitation or color change due to reactions between components and improving color fixation uniformity.

[0034] In step 1) above, the concentration of the substitute alkali in the dyeing solution can be 4~6 g / L, preferably 4.5~5.5 g / L. The concentration of the substitute alkali is one of the core parameters affecting the dyeing effect. It controls the pH value of the dyeing solution to balance the reaction efficiency between the dye and cellulose fibers, the dye stability, and the fabric properties. Both excessively high and low concentrations of the substitute alkali can lead to dyeing defects. When the substitute alkali concentration is too low, the hydroxyl groups of the fibers will not ionize sufficiently, making it difficult for the active groups of the dye to react with the cellulose fibers. This results in a large amount of dye remaining in the dyeing solution without binding to the cellulose fibers, leading to a reduced fixation rate. Simultaneously, when the substitute alkali concentration is too low, its buffering capacity is insufficient, and the pH of the dyeing solution easily drops rapidly due to the dye reaction consuming the alkali, resulting in differences in dyeing rates in different parts of the fabric, causing "color spots" and "color patches." Conversely, when the substitute alkali concentration is too high, the high concentration of alkali will cause the dye to fix rapidly on the surface of the cellulose fibers before the diffusion is complete, leading to an increased dye concentration difference between the fabric surface and interior, forming "surface dyeing" (i.e., dark on the outside and light on the inside), which is difficult to correct through post-treatment. Furthermore, excessively high concentrations of the substitute alkali can damage cellulose fibers and hydrolyze the reactive groups of reactive dyes. In this invention, the substitute alkali can be at least one of AlO533, AlO500, and AlO541. The aforementioned substitute alkali was purchased from Qingyuan Enke Materials Technology Co., Ltd.

[0035] In step 2) above, the ratio of the cellulose fiber to the dye liquor is 1:10~20, preferably 1:12~18. The liquor ratio involved in this invention is the weight ratio of the cellulose fiber to the dye liquor, that is, 1 kg of cellulose fiber requires 10~20 kg of dye liquor, preferably 12~18 kg of dye liquor.

[0036] In step 2) above, after immersing the cellulose fibers in the dye solution from step 1), the dyeing process is initially carried out at room temperature (25-40℃). During this initial dyeing, the sodium acetate / acetic acid / alkali substitute mixture is weakly acidic, weakly alkaline, or neutral, slowly releasing sodium ions. This promotes the slow adsorption of the dye by the cellulose fibers and its diffusion throughout the dyed material until uniform adsorption occurs. Then, the dye solution is heated to 60-80℃ and maintained for 20-40 minutes. During this process, the sodium acetate / acetic acid / alkali substitute mixture begins to slowly release alkaline substances, making the dye solution alkaline and gradually promoting the reaction between the reactive dye and the cellulose fibers, thus fixing the dye. The heating rate to 60-80℃ can be 2.5-3.5℃ / min. Finally, after completing the heat treatment and dyeing process, the temperature is lowered to below 40℃ at a rate of 4.5-5.5℃ / min.

[0037] In some specific implementations, cellulose fibers can be immersed in the dye solution of step 1), and dyed sequentially at 25~35℃ for 9~11 min, heated to 65~75℃ for 25~35 min, and then cooled to below 40℃.

[0038] The present invention may also include post-dyeing treatment, specifically, washing and drying the cooled dyed cellulose fibers.

[0039] The dyeing method of the present invention for improving the reproducibility of cellulose fiber dyeing is applicable to all cellulose fibers, and has excellent dyeing effect on at least one of cotton, linen and viscose fibers.

[0040] The organic carbon skeleton in the organic sodium contained in the dyeing wastewater of this invention is a key carbon source for microbial metabolism, serving as an energy source and raw material for the synthesis of cellular substances. Utilizing microorganisms to treat the dyeing wastewater of this invention can effectively improve wastewater treatment efficiency.

[0041] The following examples further illustrate the dyeing method for improving the reproducibility of cellulose fiber dyeing according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0042] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0043] The following embodiments involve , and These are three parameters based on the CIE LAB color space established by the International Commission on Illumination (CIE), used to quantify the "brightness" and "color bias" of a color. It indicates the lightness or darkness of a color; it is the "brightness" index of a color. Indicates the color bias in the "red-green" direction; It indicates the color bias in the "yellow-blue" direction. , and The value can be obtained by measuring a colorimeter. Measurements are performed under the same light source, observation angle, and measuring aperture.

[0044] This invention measures , and The colorimeter used for measurement and matching is the DS-23D spectrophotometer from Hangzhou Caipu Technology Co., Ltd.

[0045] In this invention, color difference is used To reflect the uniformity of staining, the specific calculation method is as follows:

[0046]

[0047]

[0048]

[0049] in, , , Measured at any three points on a standard cotton cloth , and The average value; , , The measurements were taken at any three points on the sample cotton fabric. , and The average of the values.

[0050] The industry standard for color difference judgment is: When the value is less than 1.0, there is almost no difference, and the human eye can hardly distinguish them; 1.0≤ At speeds <3.0, the differences are slight and can be identified by professionals, but are not easily noticed by ordinary users; 3.0≤ At version 6.0, the difference is obvious and easily identifiable by ordinary users; When the value is ≥6.0, there is a serious color difference, which does not meet the requirements at all.

[0051] Example 1 1) Prepare a dye solution with a pH of 7.0 and a volume of 30 mL by mixing 120 g / L sodium acetate-acetic acid buffer solution, 0.04 g (2% omf) Reactive Red 195 dye and 0.15 g AIO533 substitute base.

[0052] 2) Take 2g of cotton cloth and immerse it in the dye solution prepared in step 1), at 30°C. o C staining for 10 minutes, then 3 o Heating rate: C / min to 70 o C, keep warm for another 30 minutes, then add 5 o The cooling rate decreased to 40 °C / min. o C.

[0053] The dyed cotton fabric was used as a standard cotton fabric, and after being soaped and dried, three random points on the dyed cotton fabric were tested using a colorimeter. , and value.

[0054] 3) Take two pieces of cotton cloth and perform steps 1) and 2) above respectively.

[0055] The two dyed cotton fabrics mentioned above were used as sample cotton fabrics. After being soaped and dried, three random points on the sample cotton fabrics were tested using a colorimeter. , and value.

[0056] Calculate the color difference between the two sample cotton fabrics and the standard cotton fabric. and And record them in Table 1.

[0057] Example 2 1) Prepare a dye solution with a pH of 6.5 and a volume of 24 mL by mixing 110 g / L sodium acetate-acetic acid buffer solution, 0.03 g (1.5% omf) Reactive Red 195 dye and 0.11 g AIO533 substitute base.

[0058] 2) Take 2g of cotton cloth and immerse it in the dye solution prepared in step 1), at 25°C. o C staining for 11 min, then at 2.5 o Heating to 65°C at a heating rate of C / min o C, keep warm for another 35 minutes, then heat at 4.5 o The cooling rate decreased to 30 °C / min. o C.

[0059] The dyed cotton fabric was used as a standard cotton fabric, and after being soaped and dried, three random points on the dyed cotton fabric were tested using a colorimeter. , and value.

[0060] 3) Take two pieces of cotton cloth and perform steps 1) and 2) above respectively.

[0061] The two dyed cotton fabrics mentioned above were used as sample cotton fabrics. After being soaped and dried, three random points on the sample cotton fabrics were tested using a colorimeter. , and value.

[0062] Calculate the color difference between the two sample cotton fabrics and the standard cotton fabric. and And record them in Table 1.

[0063] Example 3 1) Prepare a dye solution with a pH of 7.5 and a volume of 36 mL by mixing 130 g / L sodium acetate-acetic acid buffer solution, 0.06 g (3% omf) Reactive Red 195 dye and 0.20 g AIO533 substitute base.

[0064] 2) Take 2g of cotton cloth and immerse it in the dye solution prepared in step 1), at 35°C. o C staining for 9 minutes, followed by 3.5% staining. o Heating to 75°C at a heating rate of C / min o C, keep warm for another 25 minutes, then heat at 5.5 o The cooling rate decreased to 30 °C / min. o C.

[0065] The dyed cotton fabric was used as a standard cotton fabric, and after being soaped and dried, three random points on the dyed cotton fabric were tested using a colorimeter. , and value.

[0066] 3) Take two pieces of cotton cloth and perform steps 1) and 2) above respectively.

[0067] The two dyed cotton fabrics mentioned above were used as sample cotton fabrics. After being soaped and dried, three random points on the sample cotton fabrics were tested using a colorimeter. , and value.

[0068] Calculate the color difference between the two sample cotton fabrics and the standard cotton fabric. and And record them in Table 1.

[0069] Example 4 The difference from Example 1 is that in step 1), the concentration of the sodium acetate-acetic acid buffer solution is 100 g / L.

[0070] Example 5 The difference from Example 1 is that in step 1), the concentration of the sodium acetate-acetic acid buffer solution is 140 g / L.

[0071] Example 6 The difference from Example 1 is that in step 1), the amount of AIO533 substitute alkali used is 0.12g.

[0072] Example 7 The difference from Example 1 is that in step 1), the amount of AIO533 substitute alkali used is 0.18g.

[0073] Example 8 The difference from Example 1 is that in step 1), the volume of the dye solution is 20 mL.

[0074] Example 9 The difference from Example 1 is that in step 1), the volume of the dye solution is 40 mL.

[0075] Example 10 The difference from Example 1 is that in step 2), at 25 o Stain with C for 10 minutes and then raise the temperature.

[0076] Example 11 The difference from Example 1 is that in step 2), at 40 o Stain with C for 10 minutes and then raise the temperature.

[0077] Example 12 The difference from Example 1 is that in step 2), at 30 o C staining for 8 minutes followed by warming.

[0078] Example 13 The difference from Example 1 is that in step 2), at 30 o C staining for 12 minutes followed by warming.

[0079] Example 14 The difference from Example 1 is that in step 2), 2.5 o Heating rate: C / min to 70 o C.

[0080] Example 15 The difference from Example 1 is that in step 2), 3.5 o Heating rate: C / min to 70 o C.

[0081] Example 16 The difference from Example 1 is that in step 2), 3 o Heating to 60°C at a heating rate of C / min o C.

[0082] Example 17 The difference from Example 1 is that in step 2), 3 o Heating rate: C / min to 80 o C.

[0083] Example 18 The difference from Example 1 is that in step 2), 3 o Heating rate: C / min to 70 oC, then keep warm for another 20 minutes.

[0084] Example 19 The difference from Example 1 is that in step 2), 3 o Heating rate: C / min to 70 o C, then keep warm for another 40 minutes.

[0085] Example 20 The difference from Example 1 is that in step 2), 4.5 o The cooling rate decreased to 40 °C / min. o C.

[0086] Example 21 The difference from Example 1 is that in step 2), 5.5 o The cooling rate decreased to 40 °C / min. o C.

[0087] Comparative Example 1 1) Dissolve 0.04g (2% omf) Reactive Red 195 dye in 30mL of water to prepare a dye solution.

[0088] 2) Take 2g of cotton cloth and immerse it in the dye solution prepared in step 1), at 30°C. o After staining with C for 10 minutes, add 0.6 g of NaCl, stain for another 10 minutes, then add 0.6 g of NaCl again, stain for another 10 minutes, and then... o Heating rate: C / min to 70 o C, add 0.15g of Na2CO3, incubate for 10 minutes, then add another 0.15g of Na2CO3, incubate for another 20 minutes, and then... o The cooling rate decreased to 40 °C / min. o C.

[0089] The dyed cotton fabric was used as a standard cotton fabric, and after being soaped and dried, three random points on the dyed cotton fabric were tested using a colorimeter. , and value.

[0090] 3) Take two pieces of cotton cloth and perform steps 1) and 2) above respectively.

[0091] The two dyed cotton fabrics mentioned above were used as sample cotton fabrics. After being soaped and dried, three random points on the sample cotton fabrics were tested using a colorimeter. , and value.

[0092] Calculate the color difference between the two sample cotton fabrics and the standard cotton fabric. and And record them in Table 1.

[0093] Comparative Example 2 The difference from Example 1 is that the amount of AIO533 substitute alkali used is 0.21g.

[0094] Comparative Example 3 The difference from Example 1 is that the amount of AIO533 substitute alkali used is 0.09g.

[0095] Comparative Example 4 The difference from Example 1 is that the AlO533 substitute alkali is replaced with Na2CO3.

[0096] Comparative Example 5 The difference from Example 1 is that the sodium acetate-acetic acid buffer solution is replaced with a NaCl solution.

[0097] Table 1

[0098] As can be seen from the results in Table 1, the color difference in Examples 1-21 using the dyeing method of the present invention... and All values ​​are less than 1, indicating almost no color difference, which is difficult for the human eye to distinguish. This means that the present invention improves the reproducibility of dyeing in different batches of dyed materials while reducing the number of operations in the dyeing process.

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A dyeing method for improving the reproducibility of cellulose fiber dyeing, characterized in that, The method includes: 1) Prepare a dyeing solution with a pH of 6.5~7.5 by mixing sodium acetate-acetic acid buffer solution, reactive dye, and substitute alkali; 2) Immerse the cellulose fibers in the dye solution of step 1), and dye them at 25~40℃ for 8~12 minutes, heat them to 60~80℃ and keep them at that temperature for 20~40 minutes, and then cool them down to below 40℃.

2. The method according to claim 1, characterized in that, In step 1), the concentration of the sodium acetate-acetic acid buffer solution is 100~140 g / L.

3. The method according to claim 1 or 2, characterized in that, In step 1), the amount of the reactive dye in the dyeing solution is 1~5% (omf).

4. The method according to any one of claims 1-3, characterized in that, In step 1), the reactive dye is at least one of Reactive Red 195, Reactive Yellow 145 and Reactive Blue 194.

5. The method according to any one of claims 1-4, characterized in that, In step 1), the concentration of the substitute alkali in the dye solution is 4~6 g / L.

6. The method according to any one of claims 1-5, characterized in that, In step 1), the substitute alkali includes a basic alkali agent, a buffer agent, and an auxiliary agent; The basic alkaline agent is at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; and / or The buffer is at least one of sodium silicate, triethanolamine, and sodium polyacrylate; and / or The auxiliary agent is at least one of dispersant, chelating agent and leveling agent.

7. The method according to any one of claims 1-6, characterized in that, In step 2), the ratio of the cellulose fiber to the dye liquor is 1:10~20.

8. The method according to any one of claims 1-7, characterized in that, In step 2), the heating rate is 2.5~3.5℃ / min.

9. The method according to any one of claims 1-8, characterized in that, In step 2), the cooling rate is 4.5~5.5℃ / min.

10. The method according to any one of claims 1-9, characterized in that, The cellulose fiber is at least one of cotton fiber, linen fiber, and viscose fiber.

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