Cationic dye reverse micelle emulsion and its application in acrylic dyeing

Abstract

This invention belongs to the field of eco-friendly dyeing and printing technology, and discloses a cationic dye reverse micelle emulsion and its application in acrylic yarn dyeing. The cationic dye reverse micelle emulsion comprises a cationic dye solution and fatty acids, wherein the fatty acids are at least one of C16-C18 fatty acids or fatty acids obtained from the hydrolysis of (waste) edible oils. When this cationic dye reverse micelle emulsion is used for dyeing acrylic yarn, no additional acid-base buffer system or synthetic retarder is required. Dyeing is completed under normal pressure, significantly reducing dyeing water and colored wastewater discharge. It also effectively improves the dye uptake rate and color depth of the finished product in the dyeing of dark acrylic yarn, reduces the bulkiness of the finished acrylic yarn, and increases the strength of the acrylic yarn.

Description

Technical Field

[0001] This invention belongs to the field of eco-friendly printing and dyeing technology, and specifically relates to a cationic dye reverse micelle emulsion and its application in acrylic dyeing. Background Technology

[0002] The most traditional acrylic bulky yarn is generally made by uniformly mixing acrylic fibers with different shrinkage rates to form yarn, and then undergoing a bulking process to achieve the effect of shrinking the yarn length and increasing its diameter. Acrylic bulky yarn has advantages such as being fluffy, soft, and resistant to sunlight, and is widely used in the apparel industry.

[0003] Traditional cationic dyeing methods for acrylic fibers require increasing the liquor ratio, adding pH buffers, synthetic retarders, and strictly controlling the heating rate to slow down dye uptake. This results in large quantities of colored wastewater containing pH buffers, synthetic retarders, and residual dye. Water-saving and anhydrous dyeing methods can reduce water consumption and even decrease the consumption of auxiliaries and the generation of colored wastewater. Chinese patent CN107794788B discloses a silicone-based non-aqueous medium dyeing method for packaged yarns. Specifically, it uses cyclic methylsiloxane as a solvent, requires alkali fixation during dyeing, and removes the solvent from the yarn primarily through pressure, centrifugation, and vacuum. However, cyclic methylsiloxanes have certain biotoxicity, and the silicone solvents remaining on textiles pose health risks to consumers, especially infants. Silicone solvents that leak into the environment can accumulate in aquatic microorganisms after entering water bodies. In conclusion, the use of silicon-based non-aqueous solvents as solvents in the processing of eco-textiles poses significant application risks.

[0004] The expansion of acrylic fibers mainly includes dry-heat hot air expansion, hot water expansion, and steam expansion. Chinese Patent Publication CN102268759A discloses a dry-heat hot air expansion method, specifically involving winding the yarn on a winding machine equipped with an electric heating device. The temperature of the electric heating zone is 138±2℃, and the time is 30±1s. Textile printing and dyeing equipment is typically used in open machinery, so acrylic fibers treated at high temperatures are susceptible to yellowing, browning, and carbonization due to the influence of high temperature and oxygen. Chinese Patent Publication CN106702628A discloses a hot water expansion method, specifically using recycled water pre-added during the dyeing process to expand the added yarn. Typically, the expansion of acrylic fibers in water requires a very high temperature (such as boiling water), but the temperature of recycled water is difficult to meet this condition. Therefore, an additional heat source is needed to heat the water to boiling. In the dyeing process after yarn expansion treatment, the temperature of the water in the dyeing vat needs to be slowly increased from below the glass transition temperature of acrylic fibers (70-85℃). After the expansion process, the water in the dyeing vat needs to be cooled. These processes significantly extend the processing time of the expanded acrylic yarn. Chinese Patent Publication CN101962843A discloses a steam expansion method, specifically treating acrylic skeins at 105℃ for 10 minutes, followed by twisting, heat setting, and napping treatments to finally prepare a wool-like acrylic yarn. The fiber gaps contain a certain amount of cold air, which is not conducive to the entry of water vapor. When water vapor encounters cold fibers, it condenses into water. The steam expansion treatment time is relatively short, but due to the presence of a condensate film, its uniformity is relatively difficult to guarantee. Summary of the Invention

[0005] To address the problems of complex dyeing processes for dark acrylic textiles, the generation of colored wastewater, and numerous control points in the expansion process, the primary objective of this invention is to provide a cationic dye reverse micelle emulsion.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned cationic dye reverse micelle emulsion.

[0007] Another object of the present invention is to provide the application of the above-mentioned cationic dye reverse micelle emulsion in acrylic dyeing.

[0008] Another object of the present invention is to provide a dyeing method for acrylic fibers to obtain acrylic low-bulk dyed fabrics.

[0009] The objective of this invention is achieved through the following solution:

[0010] A cationic dye reverse micelle emulsion comprising a concentrated cationic dye solution and fatty acids, wherein the fatty acids are at least one of fatty acids with 16-18 carbon atoms or fatty acids obtained by hydrolysis of (waste) edible oils.

[0011] In one embodiment, the cationic dye concentrate includes a cationic dye and water, wherein the concentration of the cationic dye is 80–500 g / L;

[0012] In one embodiment, the cationic dye is at least one of an azo cationic dye (such as at least one of cationic red X-GRL, cationic violet 2RL, cationic blue RL, cationic orange RN, and cationic red GTL), azacyanine cationic dye (cationic pale yellow 7GL), azahemicyanine cationic dye (such as at least one of cationic golden yellow X-GL, cationic blue X-GRRL, and cationic yellow X-5GL), and cyanine azo cationic dye (such as at least one of cationic red BL, cationic violet 3R, and cationic red 3G).

[0013] In one embodiment, the edible oil is preferably at least one of peanut oil, palm oil, soybean oil, and lard.

[0014] In one embodiment, the fatty acids obtained by hydrolyzing the (waste) edible oil are prepared by the following method: hydrolyzing the (waste) edible oil under acid or alkali catalysis, then recovering the unhydrolyzed waste edible oil, and then purifying it to obtain the fatty acids.

[0015] In one embodiment, the fatty acids obtained by hydrolyzing (waste) edible oil are specifically prepared by the following method: (waste) edible oil is hydrolyzed under alkaline conditions, then unreacted waste edible oil is removed by extraction with solvent 1, the pH is adjusted to 1-2 with acid, and the fatty acids are extracted again with solvent 2. Finally, solvent 2 is removed by rotary evaporation to obtain the purified fatty acids. Ethanol is preferably added during the hydrolysis process to increase the contact between reactants and accelerate the reaction; hydrolysis refers to hydrolysis at 80-100℃ for 1-5 hours; solvent 1 is preferably at least one of n-hexane, benzene, carbon tetrachloride, and cyclohexane; solvent 2 is preferably at least one of n-hexane, benzene, carbon tetrachloride, and cyclohexane.

[0016] In one embodiment, the fatty acids obtained by hydrolyzing waste edible oil are specifically prepared by the following method: Waste edible oil is hydrolyzed under acidic conditions, and the pH is adjusted to 8-10 with the addition of alkali to obtain fatty acid salt precipitates. The unreacted upper layer of waste edible oil is then recovered by centrifugation. In the collected lower layer of fatty acid salt precipitate, acid is added to adjust the pH to 1-2. The fatty acids are then extracted with solvent 2, and finally, solvent 3 is removed by rotary evaporation to obtain the purified fatty acids. Hydrolysis refers to hydrolysis at 80-100℃ for 1-5 hours; the centrifugation speed is 8000-12000 rpm / min, and the centrifugation time is 5-10 minutes.

[0017] In one embodiment, the mass ratio of the cationic dye solution to the cationic dye reverse micelle emulsion is 0.1–0.3:5–40, preferably 1:(30–70).

[0018] The average particle size of the cationic dye droplets in the reverse micelle emulsion within the fatty acid is 0.1 μm to 200 μm.

[0019] A method for preparing the above-mentioned cationic dye reverse micelle emulsion includes the following steps: adding the cationic dye to water and ultrasonically treating it to obtain a cationic dye solution; then adding the cationic dye solution to fatty acids and ultrasonically treating it to obtain the cationic dye reverse micelle emulsion.

[0020] Ultrasonic treatment refers to treatment in a cationic dye solution at 20-30°C and 300W for 10-30 minutes.

[0021] Ultrasonic treatment, which is used to obtain cationic dye reverse micelle emulsions, refers to pulsed ultrasound for 10-30 minutes at 10-30℃, power of 10-2000W, frequency of 20-30KHz, and interval time of 2-10S.

[0022] The above-mentioned cationic dye reverse micelle emulsion is used in the dyeing of acrylic yarn.

[0023] A method for dyeing acrylic yarn includes the following steps:

[0024] Acrylic yarn is immersed in cationic dye reverse micelle emulsion for dyeing, and centrifugation is performed to remove oil after dyeing.

[0025] In one embodiment, the acrylic yarn is an acrylic yarn with a moisture content of 1% to 3%.

[0026] In one embodiment, the mass ratio of the cationic dye reverse micelle emulsion to the dry weight of the acrylic yarn is (5-40):1; and the mass ratio of the cationic dye solution to the dry weight of the acrylic yarn is (1-3):10.

[0027] In one embodiment, the staining process involves first heating to 70-80°C at 1°C / min and holding for 10-30 minutes, then heating to 90-99°C at 0.5°C / min and holding for 30-60 minutes, and finally cooling to 50°C at 1°C / min.

[0028] In one embodiment, the staining process involves first heating to 80°C at 1°C / min and holding for 20 min, then heating to 95°C at 0.5°C / min and holding for 60 min, and finally cooling to 50°C at 1°C / min.

[0029] In one embodiment, the amount of the cationic dye used is 3-5% of the fiber weight.

[0030] A low-bulk acrylic dyed fabric is prepared using the above-mentioned dyeing method for acrylic yarn.

[0031] In one embodiment, the acrylic yarn dyed with the cationic dye reverse micelle emulsion shrinks in length by 5-10% and increases in diameter to 1.1-1.5 times its original size.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] Acrylic fibers are typically dyed using cationic dyes. The dyeing principle involves the fiber carrying a negative charge during the dyeing process, while the dye macromolecules carry a positive charge. The attraction between these charges forms salt bonds, resulting in high colorfastness. However, this dyeing mechanism has a drawback: the fiber's high electronegativity in the initial dyeing stage leads to a strong attraction to the cationic dye, making uneven dyeing very likely. Therefore, a certain amount of pH buffer (pH 4-6) and a retarding agent from the surfactant needs to be added to the dye bath. C16-C18 fatty acids and fatty acids obtained from the hydrolysis of (waste) edible oils have relatively long carbon chains, so their acidity is not very strong, generally meeting the pH requirements for cationic dyeing. Simultaneously, the anionic ionization products of fatty acids in water can also form unstable cationic dye-fatty acid complexes with the cationic dye through ionic bonds. During the dyeing process, as the dyeing temperature increases and the dyeing time lengthens, the dye-fatty acid complex slowly releases the cationic dye again, completing the dyeing of the acrylic fiber and achieving the purpose of retarded dyeing.

[0034] For dark-colored acrylic yarns, in the traditional dyeing process, the attraction of acrylic fibers to cationic dyes in aqueous solutions decreases in the later stages of dyeing due to the neutralizing effect of cationic dyes on the fiber's charge. On the one hand, a large amount of cationic dye remains in the residual liquor after dyeing, resulting in a large amount of colored wastewater from the processing of dark-colored acrylic yarns. On the other hand, because more dyes are used for dyeing dark-colored acrylic yarns, the competition between different colored cationic dyes is amplified during color-matching dyeing, requiring significant time to screen for compatible dyes and control the dyeing process. However, when cationic dyes are used for dyeing C16-C18 fatty acids or fatty acids obtained from the hydrolysis of (waste) edible oils, the cationic dyes, as strongly charged organic salts, exhibit high polarity. C16-C18 fatty acids or fatty acids obtained from the hydrolysis of (waste) edible oils, with their longer carbon chains, exhibit lower polarity. Cationic dyes, trace amounts of water, and some fatty acids form an unstable cationic dye-fatty acid complex under certain external forces. As dyeing progresses, almost all cationic dyes enter the macromolecular structure of acrylic fibers, completing the dyeing process. Therefore, dyeing with cationic dyes in C16-C18 fatty acids or fatty acids obtained from the hydrolysis of (waste) edible oils reduces the discharge of colored wastewater and alters the dyeing process of different cationic dyes on acrylic fibers, reducing the competitive dyeing phenomenon between different cationic dyes.

[0035] ③ Acrylic fiber expansion mainly includes dry-heat hot-air expansion, hot water expansion, and steam expansion. Known patent texts report related technologies. However, these patent texts have issues such as high-temperature treatment causing yellowing of the acrylic yarn, reclaimed water expansion making the process cumbersome and prolonging operation time, and steam condensing into a water film upon contact with cold fibers, making it relatively difficult to guarantee expansion uniformity. Therefore, a simple and efficient method for expanding acrylic fibers is still worth developing. Cationic dyes are used for dyeing C16-C18 fatty acids or fatty acids obtained from the hydrolysis of (waste) edible oils. Cationic dyes, trace amounts of water, and some fatty acids form an unstable cationic dye-fatty acid complex under certain external forces. Therefore, this invention utilizes reverse micelle emulsions to achieve micro-expansion of acrylic fibers while dyeing them. Throughout the expansion process, the fibers are immersed in fatty acids. Attached Figure Description

[0036] Figure 1 The 1H NMR spectrum of fatty acids prepared from waste edible oil with a polar substance content of 27.3% after frying in Example 1.

[0037] Figure 2The carbon NMR spectrum of fatty acids prepared from waste edible oil with a polar substance content of 27.3% after frying in Example 1.

[0038] Figure 3 The cationic dye reverse micelle emulsion prepared in Example 1 with a cationic red X-GRL dosage of 3% is shown in (a) after preparation and (b) after being left for 3 hours.

[0039] Figure 4 This is a 1000X magnified cross-sectional view of acrylic fibers dyed with cationic dye reverse micelles when the amount of cationic red X-GRL is 3% in Example 1. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0041] Unless otherwise specified, all reagents used in the examples are commercially available.

[0042] Example 1

[0043] Take 100g of waste edible oil (a mixture of fried peanut oil, palm oil, soybean oil, and lard, containing 35g peanut oil, 20g palm oil, 35g soybean oil, and 10g lard) with a polar substance content of 27.3% after frying. Add it to a 500ml solution of potassium hydroxide-ethanol (water:ethanol = 5:95) with a concentration of 2mol / L and hydrolyze at 90℃ for 5 hours. After the temperature drops to room temperature, add 100ml of n-hexane 3-5 times to extract trace amounts of unreacted waste edible oil. Then, adjust the pH of the above ethanol solution containing potassium fatty acids to around 1 using a 6mol / L hydrochloric acid solution. Finally, add 100ml of n-hexane 3-5 times to the above solution to extract fatty acids, and obtain a n-hexane solution containing fatty acids by separation after standing. Fatty acids were separated from n-hexane by rotary evaporation at room temperature. The fatty acid solution free of n-hexane was then freeze-dried for 24 hours to obtain the fatty acids used for staining. Their 1H and 1C NMR spectra are shown below. Figure 1 and Figure 2 The solvent is deuterated chloroform.

[0044] exist Figure 1 In the middle, the peak at around 11 ppm is the carboxyl group peak. Figure 2 In the middle, around 180 ppm is the carbon peak of the carboxyl group.

[0045] 0.9 g of cationic red X-GRL was added to 9.1 g of distilled water and treated with ultrasound at 25°C and 300 W for 15 min to prepare a concentrated cationic dye solution. 1 g of the concentrated cationic dye solution was added to 59 g of fatty acids obtained from the hydrolysis of waste edible oil. The mixture was then subjected to pulsed ultrasound at 20°C, 900 W, and 20 kHz for 15 min with a 5 s interval to prepare a cationic red X-GRL reverse micelle emulsion. The state diagrams of the freshly prepared cationic dye reverse micelle emulsion (a) and (b) after 3 h are shown below. Figure 3 As shown, from Figure 3 As can be seen, the cationic dye reverse micelle emulsion prepared in Example 1 has good stability and can basically meet the requirements of printing and dyeing processing for the stability of the production system.

[0046] 3g of acrylic yarn with a moisture content of 2% was placed in the above-mentioned cationic red X-GRL reverse micelle emulsion. The temperature was first increased to 70℃ at 1℃ / min and held for 15min, then increased to 95℃ at 0.5℃ / min and held for 30min, and finally decreased to 50℃ at 1℃ / min. After dyeing, the yarn was centrifuged at 5000rpm / min for 10min to remove oil, yielding low-bulk acrylic fiber dyed with reverse micelles.

[0047] Figure 4 A 1000X magnified cross-sectional view of acrylic fibers dyed with cationic dye reverse micelles when the cationic red X-GRL dosage is 3% (where 3% refers to the mass ratio of cationic dye to acrylic yarn). From Figure 4 It can be observed that the cross-sectional color of the acrylic fiber in Example 1 is relatively uniform. This demonstrates that cationic dye reverse micelle dyeing can achieve through-dyeing.

[0048] Example 2

[0049] The method for preparing fatty acids from waste cooking oil is the same as in 1.

[0050] The difference from Example 1 is that the amount of cationic red X-GRL is increased to 1.5g.

[0051] Example 3

[0052] The method for preparing fatty acids from waste cooking oil is the same as in 1.

[0053] The difference from Example 2 is that 1.5g of cationic red X-GRL is replaced with a combination of three dyes, specifically 0.5g of cationic red X-GRL, 0.5g of cationic golden yellow X-GL and 0.5g of cationic blue X-GRRL.

[0054] Example 4

[0055] The method for preparing fatty acids from waste cooking oil is the same as in 1.

[0056] The difference from Example 1 is that the amount of cationic yellow 7GL used is 0.9g.

[0057] Example 5

[0058] The method for preparing fatty acids from waste cooking oil is the same as in 1.

[0059] The difference from Example 1 is that the amount of cationic blue X-GRRL used is 0.9g.

[0060] Example 6

[0061] The difference from implementation 1 is that the fatty acid preparation method uses an acid hydrolysis process.

[0062] 100g of waste edible oil (a mixture of fried peanut oil, palm oil, soybean oil, and lard with a polar substance content of 27.3%) was added to 100ml of 3mol / L hydrochloric acid solution and hydrolyzed at 90℃ for 5 hours. After cooling to room temperature, the pH was adjusted to 9.3 with 1mol sodium hydroxide. Once no yellow precipitate was observed, the solution was centrifuged at 10000rpm / min for 5 minutes. The upper oil layer and the middle water layer were removed using a pipette to obtain sodium fatty acid precipitate. The pH of the sodium fatty acid precipitate was then adjusted to approximately 1 with 6mol / L hydrochloric acid solution. Finally, 100ml of n-hexane was added 3-5 times to extract the fatty acids. A cyclohexane solution containing fatty acids was obtained by separation after static settling. The fatty acids were separated from the n-hexane by rotary evaporation at room temperature. The fatty acid solution without n-hexane was freeze-dried for 24 hours to obtain the fatty acids used for staining.

[0063] Example 7

[0064] The staining method is the same as in Example 1.

[0065] The difference from Example 1 is that the fatty acids from the hydrolysis of waste cooking oil are replaced with oleic acid.

[0066] Example 8

[0067] The staining method is the same as in Example 1.

[0068] The difference from Example 1 is that the fatty acids from the hydrolysis of waste edible oils are replaced with palmitic acid.

[0069] Comparative Example 1

[0070] The water-based dyeing process is employed, specifically: 1.2g acetic acid, 0.6g sodium acetate, 12270.6g synthetic retarder, and 0.09g cationic red X-GRL, with a liquor ratio of 1:20. 3g of acrylic fiber with a moisture content of 2% is placed in the above dye bath. The temperature is first increased to 70℃ at 1℃ / min and held for 15min, then increased to 95℃ at 0.5℃ / min and held for 30min. Finally, the temperature is decreased to 50℃ at 1℃ / min, and the dyed acrylic fiber is removed from the dye bath.

[0071] Comparative Example 2

[0072] The water-based dyeing process is basically the same as that used in Comparative Example 1, except that the amount of cationic red X-GRL is increased to 0.15g.

[0073] Comparative Example 3

[0074] The water-based dyeing process is basically the same as Comparative Example 1, except that 0.15g of cationic red X-GRL is replaced with a combination of three dyes, specifically 0.05g of cationic red X-GRL, 0.05g of cationic golden yellow X-GL, and 0.05g of cationic blue X-GRRL.

[0075] Comparative Example 4

[0076] The water-based dyeing process is basically the same as that used in Comparative Example 1, except that the amount of cationic pale yellow 7GL used is 0.09g.

[0077] Comparative Example 5

[0078] The water-based dyeing process is basically the same as that used in Comparative Example 1, except that the amount of cationic blue X-GRRL used is 0.09g.

[0079] The staining performance of Examples 1-6 and Comparative Examples 1-5 was tested, as shown in Table 1:

[0080] Table 1. Staining performance of Examples 1-6 and Comparative Examples 1-5

[0081] Staining system Dye utilization rate K / S value Color difference Length shrinkage % Diameter increased by % Example 1 99％ 17.9 0.2 5％ 10％ Example 2 99％ 25.2 0.3 6％ 11％ Example 3 98.5％ 28.3 0.2 5％ 11％ Example 4 98.5％ 18.2 0.1 6％ 11％ Example 5 99.2％ 16.5 0.2 5％ 10％ Example 6 98.9％ 18.0 0.2 6％ 10％ Example 7 99.1％ 18.1 0.1 5％ 10.5％ Example 8 99.3％ 18.2 0.2 5％ 10.3％ Comparative Example 1 95％ 16.2 0.6 20％ 116％ Comparative Example 2 83％ 21.1 0.8 23％ 119％ Comparative Example 3 78％ 24.8 1.1 21％ 115％ Comparative Example 4 94.3％ 16.9 0.7 22％ 113％ Comparative Example 5 95.1％ 15.3 0.6 24％ 116％

[0082] Examples 1, 4, and 5, and Comparative Examples 1, 4, and 5 show that when the amount of dye used is 3% of the fiber weight, the color depth is already medium. Reverse micelle dyeing has a dye utilization rate that is about 4% higher than that of traditional water bath dyeing, and the color is 5%-10% deeper than that of traditional water bath dyeing. Most importantly, the color difference of reverse micelle dyeing is less than 0.6. This is largely due to the fact that during reverse micelle dyeing, the chromophore of the cationic dye forms a dye-fatty acid with the anionic fatty acid, which plays a role in slowing down the dyeing process. In reverse micelle dyeing, the length shrinkage of the acrylic yarn is only 20%-25% of that in traditional water bath dyeing, and the diameter increase is only 5%-10%. This is because in reverse micelle dyeing, the amount of water used is only 10-30% of the yarn weight, and there are not enough water molecules to break the hydrogen bonds in the acrylic fiber molecules.

[0083] A comparison of Example 1 with Examples 7 and 8 shows that the dyeing effect of fatty acids hydrolyzed from waste cooking oil is basically equivalent to that of pure oleic acid and palmitic acid.

[0084] The comparison between Example 2 and Comparative Example 2 shows that when the dye dosage is 5% of the fiber weight, the color depth is already dark. Reverse micelle dyeing achieves approximately 19% higher dye utilization than traditional water bath dyeing. This is because in traditional dark-dyeing of acrylic fibers, the electrostatic attraction of the acrylic fiber to the cationic dye decreases in the later stages of dyeing, resulting in a greater amount of cationic dye remaining in the water. In contrast, reverse micelle dyeing uses temperature to slowly break down the semi-stable relationship between the dye and fatty acids, allowing a large amount of dye to still enter the acrylic fiber in the later stages of dyeing.

[0085] A comparison of Examples 1 and 6 shows that when the dye dosage is 3% of the fiber weight, there is no essential difference in dye utilization, color depth, color difference, length shrinkage, and diameter change. This is because, when waste edible oil is hydrolyzed under acidic conditions, the final hydrolysis product is also fatty acids.

[0086] In color-matching dyeing, acrylic fibers require strict control over conditions such as cationic dyes, temperature, leveling agents, and pH values. A comparison of Example 3 and Comparative Example 3 shows that reverse micellar dyeing exhibits excellent color uniformity. This is because in traditional acrylic color-matching dyeing, acrylic fibers have a strong electrostatic attraction to cationic dyes, leading to significant competition between cationic dyes with different structures. However, in reverse micellar dyeing, a semi-stable relationship is formed between the cationic dye and fatty acids. By controlling the temperature, this semi-stable relationship can be slowly broken, resulting in the slow release of the dye.

[0087] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for dyeing acrylic yarn, characterized in that... Includes the following steps: Acrylic yarn is immersed in cationic dye reverse micelle emulsion for dyeing, and centrifugation is performed to remove oil after dyeing. The cationic dye reverse micelle emulsion comprises a cationic dye solution and fatty acids, wherein the fatty acids are fatty acids obtained by hydrolyzing waste edible oils; The method for preparing the cationic dye reverse micelle emulsion includes the following steps: Cationic dye is added to water and ultrasonically treated to obtain a cationic dye solution; then the cationic dye solution is added to fatty acids and ultrasonically treated to obtain a cationic dye reverse micelle emulsion. The waste cooking oil is a mixture of peanut oil, palm oil, soybean oil, and lard after frying. The acrylic yarn mentioned is acrylic yarn with a moisture content of 1% to 3%.

2. The dyeing method for acrylic yarn according to claim 1, characterized in that: The cationic dye solution comprises cationic dye and water, wherein the concentration of the cationic dye is 80~500g / L; the mass ratio of the cationic dye solution to the cationic dye reverse micelle emulsion is 0.1~0.3:5~40.

3. The dyeing method for acrylic yarn according to claim 1 or 2, characterized in that: The cationic dye is at least one of azo cationic dyes, azircyanine cationic dyes, azirheycyanine cationic dyes, and cyanine azo cationic dyes.

4. The dyeing method for acrylic yarn according to claim 1, characterized in that: The fatty acids obtained from the hydrolysis of edible oils and the fatty acids obtained from the hydrolysis of waste edible oils are prepared by the following method: edible oils or waste edible oils are hydrolyzed under acid or alkali catalysis, and then the unhydrolyzed edible oils are recovered and purified to obtain fatty acids.

5. The dyeing method for acrylic yarn according to claim 1, characterized in that: The fatty acids obtained from the hydrolysis of waste edible oil or edible oil are specifically prepared by the following method: Waste edible oil or edible oil is hydrolyzed under alkaline conditions, then unreacted waste edible oil is removed by extraction with solvent 1, the pH is adjusted to 1-2 by adding acid, and the fatty acids are then extracted with solvent 2. Finally, solvent 2 is removed by rotary evaporation to obtain the purified fatty acids. Hydrolysis refers to hydrolysis at 80-100℃ for 1-5 hours; solvent 1 is at least one of n-hexane, benzene, carbon tetrachloride, and cyclohexane; solvent 2 is at least one of n-hexane, benzene, carbon tetrachloride, and cyclohexane. Alternatively, the fatty acids obtained from the hydrolysis of waste edible oil or the fatty acids obtained from the hydrolysis of edible oil are specifically prepared by the following method: Waste edible oil or edible oil is hydrolyzed under acidic conditions, and the pH is adjusted to 8-10 by adding alkali to obtain fatty acid salt precipitates. Then, the unreacted waste edible oil in the upper layer is recovered by centrifugation. In the collected lower layer of fatty acid salt precipitates, acid is added to adjust the pH to 1-2. The fatty acids are then extracted with solvent 2, and finally solvent 3 is removed by rotary evaporation to obtain the purified fatty acids. Hydrolysis refers to hydrolysis at 80-100℃ for 1-5 hours; the centrifugation speed is 8000-12000 rpm / min, and the centrifugation time is 5-10 minutes.

6. The dyeing method for acrylic yarn according to claim 1, characterized in that: The mass ratio of the cationic dye reverse micelle emulsion to the dry weight of the acrylic yarn is (5-40):

1. The staining process involves first raising the temperature to 70-80℃ at a rate of 1℃ / min and holding it for 10-30 minutes, then raising the temperature to 90-99℃ at a rate of 0.5℃ / min and holding it for 30-60 minutes, and finally lowering the temperature to 50℃ at a rate of 1℃ / min.

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