Printing and dyeing auxiliary and dyeing method thereof

Abstract

The invention relates to a printing and dyeing auxiliary agent and a dyeing method thereof. The printing and dyeing auxiliary agent is prepared from the following raw materials in parts by weight: 96 to 98 parts of anhydrous sodium sulphate, 1.2 to 1.8 parts of multifunctional dispersing agent DM-1501, 0.8 to 1.2 parts of 8-hydroxy-2-methylquinolyl Gemini surfactant and 0.3 to 0.7 part of alkyl glycoside. The preparation raw materials of the 8-hydroxy-2-methyl quinolyl Gemini surface active agent comprise 8-hydroxy-2-methyl quinoline and sulfonic acid ester. The printing and dyeing auxiliary agent can improve the dyeing uniformity and color fastness of cotton cakes. The K / S value of the dyed cotton cake is gt; 26.5, the dye uptake rate gt; the color fastness to wet rubbing is gt; grade 3, the color fastness to washing is gt; and grade 4.

Description

Technical Field

[0001] This application relates to the field of dyeing and printing auxiliaries, and in particular to a dyeing and printing auxiliary agent and a dyeing method thereof. Background Technology

[0002] Loose cotton (loose fiber) dyeing is a crucial and fundamental step in the textile printing and dyeing industry. However, existing loose cotton cake dyeing processes and conventional dyeing auxiliaries have significant drawbacks in practical applications: First, the evenness and penetration of the dye are poor. The high-pressure, compacted thick cotton cake results in high resistance to dye penetration, causing dye to be easily adsorbed and fixed on the outer layer while insufficient exchange occurs in the inner layer, resulting in a "dark on the outside, light on the inside" color problem. Second, it is difficult to achieve both high dye uptake and color fastness in dark-colored dyeing. Dyes tend to aggregate in high-concentration dye liquors, and the dispersion performance of conventional auxiliaries decreases in high-salt and high-alkali environments, leading to the accumulation of floating dye that is difficult to remove due to the difficulty of washing the inside of the cotton cake. As a result, the finished product has low wet rubbing and washing color fastness.

[0003] Therefore, there is an urgent need in this field to develop new dyeing auxiliaries and dyeing methods that can maintain efficient dispersion and penetration in complex dye bath environments, thereby solving the technical problems of poor dyeing uniformity and poor color fastness of dark colors in the dyeing of loose cotton cakes. Summary of the Invention

[0004] This invention provides a dyeing auxiliary agent and a dyeing method thereof, which can solve the problems of poor uniformity in dyeing thick cakes and poor color fastness to dark colors.

[0005] In a first aspect of this application, a printing and dyeing auxiliary agent is provided, comprising the following raw materials in parts by weight: 96-98 parts by weight of sodium sulfate, 1.2-1.8 parts by weight of multifunctional dispersant DM-1501, 0.8-1.2 parts by weight of 8-hydroxy-2-methylquinoline Gemini surfactant, and 0.3-0.7 parts by weight of alkyl glycoside; wherein the raw materials for preparing the 8-hydroxy-2-methylquinoline Gemini surfactant include 8-hydroxy-2-methylquinoline and sulfonate.

[0006] By adopting the above technical solution, this invention provides a dyeing auxiliary agent that can promote uniform dyeing of cotton cakes and improve the wet rubbing fastness and wash fastness of the cotton cakes. This may be because the 8-hydroxy-2-methylquinoline Gemini surfactant has a "double-headed, double-tailed" structure, exhibiting salt and alkali resistance and dye solubilizing and dispersing ability in the dye bath; while the alkyl glycoside has excellent wetting and penetrating properties; after the two are combined, the alkyl glycoside rapidly reduces the surface tension and provides penetration channels, while the Gemini surfactant stabilizes and disperses the dye and achieves controllable slow dyeing. The two work synergistically to achieve internal uniform dyeing and fixation. Consequently, the K / S value of the dyed cotton cake is >26.5, the dyeing rate is >70%, the wet rubbing fastness is >3, and the wash fastness is >4.

[0007] Optionally, the weight ratio of the 8-hydroxy-2-methylquinolinyl Gemini surfactant to the alkyl glycoside is (8-28):7.

[0008] By adopting the above technical solution and adjusting the amount of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside according to the above weight ratio, when the weight ratio of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside is (8-28):7, it can be ensured that the cotton cake is dyed evenly and improve the wet rubbing fastness and water washing fastness of the cotton cake.

[0009] Optionally, in the 8-hydroxy-2-methylquinoline Gemini surfactant, the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is 21:(9-14).

[0010] By adopting the above technical solution and adjusting the amount of 8-hydroxy-2-methylquinoline and sulfonate according to the above molar ratio, when the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is 21:(9-14), it can be ensured that the cotton cake is dyed evenly and has good wet rubbing fastness and water washing fastness.

[0011] Optionally, the preparation method of the 8-hydroxy-2-methylquinolinyl Gemini surfactant includes the following steps: a1. Polyethylene glycol and p-toluenesulfonyl chloride were added to a reaction vessel, followed by dichloromethane. After stirring until homogeneous, the mixture was cooled, and triethylamine was added. The reaction was carried out, filtered, and the filtrate was allowed to settle with water. The liquid was separated, the organic phase was collected, dried, filtered, and rotary evaporated to obtain the sulfonate ester. a2. Add the sulfonate ester from step a1 to N,N-dimethylformamide, stir and dissolve under inert gas to obtain a sulfonate ester solution; a3. Add 8-hydroxy-2-methylquinoline to the reaction vessel, add N,N-dimethylformamide, stir, add sodium hydride at 0-10℃, stir, add the sulfonate solution from step a2 to the reaction vessel, react, cool, extract, dry, and obtain crude product; a4. Wash, dry, filter, rotary evaporate, and dry the crude product from step a3 to obtain 8-hydroxy-2-methylquinoline Gemini surfactant.

[0012] Optionally, in step a3, the molar ratio of 8-hydroxy-2-methylquinoline to sodium hydride is 1:(2-2.4).

[0013] Optionally, in step a4, the crude product from step a3 is washed with hydrochloric acid, sodium bicarbonate, and brine.

[0014] In a second aspect, this application provides a dyeing method using the dyeing auxiliaries described in the first aspect, comprising the following steps: S1. Weigh the loose cotton and beat it into a cake to obtain a cotton cake; S2. The cotton cake obtained in step S1 is suspended into a dyeing vat, a low-temperature pretreatment agent and soda ash are added, the temperature is raised to 55-65℃ for 15-25 minutes, the water is drained, and the pretreated cotton cake is obtained. S3. Dye the pretreated cotton cake obtained in step S2 by adding water and dye, running for 8-12 minutes, then adding printing and dyeing auxiliaries, heating to 55-65℃ and holding for 3-7 minutes, then adding soda ash, holding for color fixation for 50-70 minutes, stopping the main pump, opening the cover, cooling, draining water, and obtaining semi-finished dyed cotton cake. S4. The semi-finished dyed cotton cake obtained in step S3 is post-treated by water intake, cold water washing, and drainage; water intake again, acetic acid added, acid washing, and drainage; water intake again, auxiliary agent added, and treatment at 75-85℃ for 10-20 minutes, and drainage; water intake again, cold water washing, and drainage to obtain the semi-finished post-treated cotton cake. S5. The semi-finished cotton cake obtained in step S4 is subjected to color-fixing and softening treatment. Water is added, and color-fixing agent, softener and antistatic agent are added. The mixture is treated at 50-60℃ for 12-18 minutes, and then drained to obtain the semi-finished color-fixed cotton cake. S6. Dehydrate, dry, and package the semi-finished color-fixing cotton cake obtained in step S5 to obtain the finished dyed cotton cake.

[0015] Optionally, in step S2, the mass concentration of the low-temperature pretreatment agent is 1.5-2.5 g / L, and the mass concentration of the soda ash is 1-3 g / L.

[0016] Optionally, the cryogenic pretreatment agent is NCD.

[0017] Optionally, in step S3, the mass concentration of the dyeing and printing auxiliary agent is 60-70 g / L, and the mass concentration of the soda ash is 15-25 g / L.

[0018] Optionally, in step S4, the mass concentration of acetic acid during pickling is 1-2 g / L.

[0019] Optionally, in step S4, the soaping agent is soaping agent DM-1573, and the mass concentration of soaping agent DM-1573 is 0.5-1.5 g / L.

[0020] Optionally, in step S5, the fixing agent is DM-2518, and the mass of DM-2518 is 0.6-1.0% of the mass of the dyed cotton cake; the softener is hydrophilic silicone oil 801, and the mass concentration of hydrophilic silicone oil 801 is 0.5-1.5 g / L; and the antistatic agent is ZDL, and the mass concentration of ZDL is 0.6-1.0 g / L.

[0021] In summary, the present invention has at least one of the following beneficial technical effects: 1. This invention provides a dyeing auxiliary agent that promotes uniform dyeing of cotton cakes and improves their wet rubbing fastness and wash fastness. The 8-hydroxy-2-methylquinolinyl Gemini surfactant has a "double-headed, double-tailed" structure, exhibiting salt and alkali resistance and dye solubilizing and dispersing ability in the dye bath; while the alkyl glycoside has excellent wetting and penetrating properties. When combined, the alkyl glycoside rapidly reduces surface tension and provides penetration channels, while the Gemini surfactant stabilizes and disperses the dye, achieving controlled slow dyeing. The two work synergistically to achieve internal uniform dyeing and fixation. Consequently, the dyed cotton cake has a K / S value > 26.5, a dye uptake > 70%, wet rubbing fastness > grade 3, and wash fastness > grade 4.

[0022] 2. This invention provides a dyeing method for printing and dyeing auxiliaries. The finished cotton cake dyed by this method has good wet rubbing fastness and water washing fastness, and the dyeing is uniform. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0024] Polyethylene glycol was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. (P815616), 8-hydroxy-2-methylquinoline (2-methyl-8-hydroxyquinoline) was purchased from Anaiji Chemical (E020504), sodium sulfate was purchased from Wuhan Jiyesheng Chemical Co., Ltd., multifunctional dispersant DM-1501 was purchased from Guangdong Demei Fine Chemical Group Co., Ltd., alkyl glycosides were purchased from Yancheng Green Chemical Co., Ltd., low-temperature pretreatment agent NCD was purchased from Hubei Shenyuan Textile Technology Co., Ltd., black FL-N, black B 150% and deep red HS-D were all purchased from Hubei Liyuan Technology Co., Ltd., soaping agent DM-1573 was purchased from Guangdong Demei Fine Chemical Group Co., Ltd., color fixing agent DM-2518 was purchased from Guangdong Demei Fine Chemical Group Co., Ltd., hydrophilic silicone oil 801 was purchased from Jiangmen Shenye Technology Co., Ltd., and antistatic agent ZDL was purchased from Jiangmen Shenye Technology Co., Ltd.

[0025] Preparation Example 1 Preparation of 8-hydroxy-2-methylquinolinyl Gemini surfactant a1. Add 40g of polyethylene glycol and 38.5g of p-toluenesulfonyl chloride to a reaction vessel, then add 150mL of dichloromethane, stir well, cool to 2℃ in an ice-water bath, slowly add 20.2g of triethylamine, react at room temperature and atmospheric pressure for 30h, filter, collect the filtrate, precipitate the filtrate twice with saturated saline solution, separate the liquid and take the organic phase, dry with anhydrous sodium sulfate for 2h, filter, and rotary evaporate under reduced pressure at 42℃ to obtain sulfonate ester; a2. Add the sulfonate from step a1 to 80 mL of N,N-dimethylformamide, stir and dissolve under nitrogen protection to obtain a sulfonate solution; a3. Add 0.013 mol of 8-hydroxy-2-methylquinoline to the reaction vessel, replace the air in the reaction vessel with nitrogen, add 50 mL of N,N-dimethylformamide and stir to dissolve, slowly add 0.0286 mol of sodium hydride at 5 °C, stir for 1 h, then inject the sulfonate solution from step a2 into the reaction vessel with a needle, the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is 13:7, heat to 70 °C under normal pressure and react for 16 h, after the reaction is completed, cool to 20 °C, extract with ethyl acetate for 15 min, dry by rotary evaporation to obtain crude product; a4. The crude product from step a3 was first washed twice with 0.1 mol / L hydrochloric acid, then once with saturated sodium bicarbonate solution, and then washed with saturated brine until neutral. Finally, it was dried with anhydrous sodium sulfate, filtered, and rotary evaporated under reduced pressure at 42°C. The solid was then washed twice with a small amount of cold ether and dried under vacuum (10 kPa, 25°C, 24 h) to obtain 8-hydroxy-2-methylquinolinyl Gemini surfactant.

[0026] Preparation Example 2 The difference between Preparation Example 2 and Preparation Example 1 is that in step a3, the total molar amount of 8-hydroxy-2-methylquinoline and sulfonate remains unchanged, and the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is adjusted to 7:3.

[0027] Preparation Example 3 The difference between Preparation Example 3 and Preparation Example 1 is that in step a3, the total molar amount of 8-hydroxy-2-methylquinoline and sulfonate remains unchanged, and the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is adjusted to 3:2.

[0028] Comparative Preparation Example 1 The difference between Preparation Example 1 and Preparation Example 2 is that in step a3, equimolar amounts of 8-hydroxy-2-methylquinoline are replaced with 8-hydroxyquinoline.

[0029] Specifically, step a3 is different, and is as follows: a3, 0.013 mol of 8-hydroxyquinoline is added to the reaction vessel, the air in the reaction vessel is replaced with nitrogen, 50 mL of N,N-dimethylformamide is added and stirred to dissolve, 0.0286 mol of sodium hydride is slowly added at 5 °C, and stirred for 1 h, then the sulfonate solution from step a2 is injected into the reaction vessel with a needle, the molar ratio of 8-hydroxyquinoline to sulfonate is 13:7, the temperature is raised to 70 °C under normal pressure and reacted for 16 h, after the reaction is completed, the temperature is lowered to 20 °C, and extracted with ethyl acetate for 15 min, and dried by rotary evaporation to obtain the crude product.

[0030] Accordingly, step a4 is as follows: a4. The crude product from step a3 is first washed twice with 0.1 mol / L hydrochloric acid, then washed once with saturated sodium bicarbonate solution, washed with saturated brine until neutral, dried with anhydrous sodium sulfate, filtered, rotary evaporated under reduced pressure at 42°C, washed twice with a small amount of cold diethyl ether, and dried under vacuum (10 kPa, 25°C, 24 h) to obtain 8-hydroxyquinoline Gemini surfactant.

[0031] Example 1

[0032] Example 1 provides a dyeing and printing auxiliary agent and its dyeing method. The dyeing and printing auxiliary agent comprises the following raw materials in parts by weight: 97 parts by weight of sodium sulfate, 1.5 parts by weight of multifunctional dispersant DM-1501, 1.0 part by weight of 8-hydroxy-2-methylquinolinyl Gemini surfactant prepared by the preparation method of Example 1, and 0.5 parts by weight of alkyl glycoside. The preparation method of the dyeing and printing auxiliary agent is as follows: the raw materials are mixed and stirred to obtain the dyeing and printing auxiliary agent.

[0033] The staining method includes the following steps: S1. Cotton cake making: Weigh the loose cotton and make it into cakes as required. Control the thickness of the cotton cake to be 50cm and the height to be 85cm. The weight of a single cotton cake is 310kg. Two cakes are put into one vat, and the total dyeing weight is 620kg. S2. Pretreatment before entering the dyeing vat: The cotton cake obtained in step S1 is hoisted into the dyeing vat, the cover is closed, water is introduced and pressure is tested to confirm that there is no leakage; then low-temperature pretreatment agent NCD and soda ash are added, wherein the mass concentration of low-temperature pretreatment agent NCD is 2g / L and the mass concentration of soda ash is 2g / L, the temperature is raised to 60℃ and treated for 20 minutes, and after completion, the water is drained to obtain the pretreated cotton cake. S3. Dyeing: The pretreated cotton cake obtained in step S2 is dyed by adding water and dye (black FL-N 6.0wt%, black B150% 1.0wt%, dark red HS-D 0.5wt%), with a liquor ratio of 1:5, and running for 10 minutes. The mass percentage of dye refers to the mass percentage of dye to the mass of the cotton cake being dyed. Then, dyeing auxiliaries are added, with a mass concentration of 70g / L. The temperature is raised to 60℃ and held for 5 minutes. Then, soda ash is added, with a mass concentration of 20g / L, and the temperature is held for 60 minutes to fix the color. After the holding time is completed, the main pump is stopped, the cover is opened, and the water is drained when the temperature of the main cylinder drops to 45℃ to obtain a semi-finished dyed cotton cake. S4. Post-treatment: The semi-finished dyed cotton cake obtained in step S3 is post-treated by first washing with water and cold water for 5 minutes, then draining; then washing with water again, adding glacial acetic acid with a mass concentration of 1.5 g / L, and acid washing for 5 minutes, then draining; then washing with water again, adding soaping agent DM-1573 with a mass concentration of 1 g / L, and treating at 80℃ for 15 minutes, then draining; then washing with water again and cold water for 5 minutes, and draining to obtain the semi-finished post-treated cotton cake. S5. Softening after color fixation: The semi-finished cotton cake obtained in step S4 is subjected to softening treatment after color fixation. Water is added, and color fixation agent DM-2518 is added. The mass of color fixation agent DM-2518 is 0.8% of the mass of the dyed cotton cake. Softener (hydrophilic silicone oil 801) and antistatic agent ZDL are then added. The mass concentration of hydrophilic silicone oil 801 is 1 g / L and the mass concentration of antistatic agent ZDL is 0.8 g / L. The treatment is carried out at 55℃ for 15 min. After completion, the water is drained from the vat to obtain the semi-finished color-fixed cotton cake. S6. Dehydration, drying and packaging: The semi-finished color-fixed cotton cake obtained in step S5 is hoisted into the dehydrator for dehydration. After dehydration, it is hoisted out, put into the dryer for drying, and then put into the packaging machine for packaging to obtain the finished dyed cotton cake.

[0034] Example 2

[0035] Example 2 provides a dyeing and printing auxiliary agent and its dyeing method. The difference from Example 1 is that, in the raw materials of the dyeing and printing auxiliary agent, the 8-hydroxy-2-methylquinoline Gemini surfactant prepared by the preparation method of Example 1 is replaced by an equal weight part of the 8-hydroxy-2-methylquinoline Gemini surfactant prepared by the preparation method of Example 2.

[0036] The staining method is the same as in Example 1.

[0037] Example 3

[0038] Example 3 provides a dyeing and printing auxiliary agent and its dyeing method. The difference from Example 1 is that, in the raw materials of the dyeing and printing auxiliary agent, the 8-hydroxy-2-methylquinoline Gemini surfactant prepared by the preparation method of Example 1 is replaced by an equal weight part of the 8-hydroxy-2-methylquinoline Gemini surfactant prepared by the preparation method of Example 3.

[0039] The staining method is the same as in Example 1.

[0040] Example 4

[0041] Example 4 provides a dyeing and printing auxiliary agent and its dyeing method. The difference from Example 1 is that the total weight of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside in the raw materials of the dyeing and printing auxiliary agent remains unchanged, and the weight ratio of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside is 4:1.

[0042] The staining method is the same as in Example 1.

[0043] Example 5

[0044] Example 5 provides a dyeing and printing auxiliary agent and its dyeing method. The difference from Example 1 is that the total weight of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside in the raw materials of the dyeing and printing auxiliary agent remains unchanged, and the weight ratio of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside is 8:7.

[0045] The staining method is the same as in Example 1.

[0046] Comparative Example 1 Comparative Example 1 provides a dyeing and printing auxiliary agent and its dyeing method. The difference from Example 1 is that in the raw materials of the dyeing and printing auxiliary agent, an equal part by weight of 8-hydroxy-2-methylquinolinyl Gemini surfactant is replaced with alkyl glycoside.

[0047] The staining method is the same as in Example 1.

[0048] Comparative Example 2 Comparative Example 2 provides a dyeing and printing auxiliary agent and its dyeing method. The difference from Example 1 is that in the raw materials of the dyeing and printing auxiliary agent, alkyl glycosides are replaced by 8-hydroxy-2-methylquinolinyl Gemini surfactant in equal parts by weight.

[0049] The staining method is the same as in Example 1.

[0050] Comparative Example 3 Comparative Example 3 provides a dyeing auxiliary agent and its dyeing method. The difference from Example 1 is that, in the raw materials of the dyeing auxiliary agent, an equal weight part of the 8-hydroxy-2-methylquinoline Gemini surfactant prepared by the preparation method of Preparation Example 1 is replaced with the 8-hydroxy-2-methylquinoline Gemini surfactant prepared by the preparation method of Comparative Example 1.

[0051] The staining method is the same as in Example 1.

[0052] Performance testing The finished dyed cotton cakes obtained from Examples 1-5 and Comparative Examples 1-3 were tested for rubbing fastness according to GB / T 3920-2008; and for water fastness according to GB / T5713-2013. The results are shown in Table 1.

[0053] The K / S values ​​of the finished dyed cotton cakes obtained in Examples 1-5 and Comparative Examples 1-3 were measured using a HunterLabColorQuest XE spectrophotometer, and the results are shown in Table 2. The absorbance of the dye bath before and after dyeing was measured using a spectrophotometer at the maximum absorption wavelength for the finished dyed cotton cakes obtained in Examples 1-5 and Comparative Examples 1-3. The dyeing percentage was calculated according to the following formula: C t = (1 – A1 / A0) × 100%, the results are shown in Table 2; In the formula: A0 is the absorbance of the original dye solution; A1 is the absorbance of the residual solution after dyeing.

[0054] Table 1

[0055] Table 2

[0056] Results Analysis and Summary Based on Examples 1-3, Tables 1 and 2, it can be seen that adjusting the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate in the 8-hydroxy-2-methylquinoline Gemini surfactant can affect the color fastness, dyeing uniformity, and dyeing rate of the cotton cake. In Example 1, when the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is 13:7, the dyeing effect and color fastness of the cotton cake are better, and the dyeing auxiliary agent achieves the best dyeing effect, which is superior to Examples 2 and 3.

[0057] Based on Examples 1, 4-5, Tables 1 and 2, it can be seen that adjusting the weight ratio of 8-hydroxy-2-methylquinoline Gemini surfactant and alkyl glycoside can affect the color fastness, dyeing uniformity, and dyeing rate of cotton cake. In Example 1, when the mass ratio of 8-hydroxy-2-methylquinoline Gemini surfactant to alkyl glycoside is 2:1, the dyeing effect and color fastness of the cotton cake are better, and the dyeing auxiliary agent helps the dyeing effect to reach the best, which is better than Examples 4 and 5.

[0058] Based on Examples 1, Comparative Examples 1-2, and Tables 1 and 2, it can be seen that in Comparative Example 1, replacing an equal part by weight of 8-hydroxy-2-methylquinoline Gemini surfactant with alkyl glycosides, and in Comparative Example 2, replacing an equal part by weight of alkyl glycosides with 8-hydroxy-2-methylquinoline Gemini surfactant, resulted in significantly worse dyeing effects and color fastness in cotton cakes compared to Example 1. This may be because, when using alkyl glycosides alone, although the penetration is good, the dispersion stability of dark dyes in high-salt, high-alkali dye baths is insufficient; while when using 8-hydroxy-2-methylquinoline Gemini surfactant alone, although the dispersing and solubilizing ability is strong, the penetration rate into the thick cotton cake is relatively slow. After the two are combined, the wetting and penetrating properties of alkyl glycosides and the dispersing and retarding properties of Gemini surfactants produce a synergistic effect, enabling dye molecules to migrate and fix more evenly into the cotton cake, thereby significantly improving levelness and color fastness.

[0059] Based on Examples 1 and 3, as well as Tables 1 and 2, it is evident that in Comparative Example 3, replacing 8-hydroxy-2-methylquinoline with an equimolar amount of 8-hydroxyquinoline resulted in significantly worse dyeing effects and colorfastness of the cotton cake compared to Example 1. This may be because the introduction of the 2-methyl group moderately increases the hydrophobicity and molecular volume of the hydrophobic group, enhancing the hydrophobic interaction between the Gemini surfactant and the dye molecules. Simultaneously, it optimizes the adsorption orientation of the surfactant molecules on the fiber surface, facilitating the formation of a stable micelle structure and achieving controlled retarded dyeing. In contrast, Comparative Example 3 lacks this methyl group, weakening the interaction between the hydrophobic group and the dye and fiber, reducing micelle stability, and decreasing the retarded and migration dyeing effects. Consequently, the dye uptake rate and leveling / penetration effects deteriorate, leading to reduced colorfastness.

[0060] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the products, methods and principles of this application should be covered within the scope of protection of this application.

Claims

1. A dyeing and printing auxiliary agent, characterized in that, The raw materials include the following parts by weight: 96-98 parts by weight of sodium sulfate, 1.2-1.8 parts by weight of multifunctional dispersant DM-1501, 0.8-1.2 parts by weight of 8-hydroxy-2-methylquinolinyl Gemini surfactant, and 0.3-0.7 parts by weight of alkyl glycoside. The raw materials for preparing the 8-hydroxy-2-methylquinoline Gemini surfactant include 8-hydroxy-2-methylquinoline and sulfonate.

2. The dyeing and printing auxiliary agent according to claim 1, characterized in that, The weight ratio of the 8-hydroxy-2-methylquinolinyl Gemini surfactant to the alkyl glycoside is (8-28):

7.

3. The dyeing and printing auxiliary agent according to claim 1, characterized in that, In the 8-hydroxy-2-methylquinoline Gemini surfactant, the molar ratio of 8-hydroxy-2-methylquinoline to sulfonate is 21:(9-14).

4. The dyeing and printing auxiliary agent according to claim 1, characterized in that, The preparation method of the 8-hydroxy-2-methylquinolinyl Gemini surfactant includes the following steps: a1. Polyethylene glycol and p-toluenesulfonyl chloride were added to a reaction vessel, followed by dichloromethane. After stirring until homogeneous, the mixture was cooled, and triethylamine was added. The reaction was carried out, filtered, and the filtrate was allowed to settle with water. The liquid was separated, the organic phase was collected, dried, filtered, and rotary evaporated to obtain the sulfonate ester. a2. Add the sulfonate ester from step a1 to N,N-dimethylformamide, stir and dissolve under inert gas to obtain a sulfonate ester solution; a3. Add 8-hydroxy-2-methylquinoline to the reaction vessel, add N,N-dimethylformamide, stir, add sodium hydride at 0-10℃, stir, add the sulfonate solution from step a2 to the reaction vessel, react, cool, extract, dry, and obtain crude product; a4. Wash, dry, filter, rotary evaporate, and dry the crude product from step a3 to obtain 8-hydroxy-2-methylquinoline Gemini surfactant.

5. The dyeing and printing auxiliary agent according to claim 4, characterized in that, In step a3, the molar ratio of 8-hydroxy-2-methylquinoline to sodium hydride is 1:(2-2.4).

6. The dyeing and printing auxiliary agent according to claim 4, characterized in that, In step a4, the crude product from step a3 is washed with hydrochloric acid, sodium bicarbonate, and brine.

7. A dyeing method using the dyeing auxiliary agent according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Weigh the loose cotton and beat it into a cake to obtain a cotton cake; S2. The cotton cake obtained in step S1 is suspended into a dyeing vat, a low-temperature pretreatment agent and soda ash are added, the temperature is raised to 55-65℃ for 15-25 minutes, the water is drained, and the pretreated cotton cake is obtained. S3. Dye the pretreated cotton cake obtained in step S2 by adding water and dye, running for 8-12 minutes, then adding printing and dyeing auxiliaries, heating to 55-65℃ and holding for 3-7 minutes, then adding soda ash, holding for color fixation for 50-70 minutes, stopping the main pump, opening the cover, cooling, draining water, and obtaining semi-finished dyed cotton cake. S4. The semi-finished dyed cotton cake obtained in step S3 is post-treated by water intake, cold water washing, and drainage; water intake again, acetic acid added, acid washing, and drainage; water intake again, soaping agent added, and treatment at 75-85℃ for 10-20 minutes, and drainage; water intake again, cold water washing, and drainage to obtain the semi-finished post-treated cotton cake. S5. The semi-finished cotton cake obtained in step S4 is subjected to color-fixing and softening treatment. Water is added, and color-fixing agent, softener and antistatic agent are added. The mixture is treated at 50-60℃ for 12-18 minutes, and then drained to obtain the semi-finished color-fixed cotton cake. S6. Dehydrate, dry, and package the semi-finished color-fixing cotton cake obtained in step S5 to obtain the finished dyed cotton cake.

8. The dyeing method using the dyeing auxiliary agent according to claim 7, characterized in that, In step S2, the mass concentration of the low-temperature pretreatment agent is 1.5-2.5 g / L, and the mass concentration of the soda ash is 1-3 g / L.

9. The dyeing method using the dyeing auxiliary agent according to claim 7, characterized in that, In step S3, the mass concentration of the dyeing and printing auxiliary agent is 60-70 g / L, and the mass concentration of the soda ash is 15-25 g / L.

10. The dyeing method using the dyeing auxiliary agent according to claim 7, characterized in that, In step S4, the mass concentration of acetic acid during pickling is 1-2 g / L.

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