Method for preparing alkali-resistant liquid disperse dye through anti-solvent crystallization

Abstract

The invention provides a method for preparing an alkali-resistant liquid disperse dye by an anti-solvent crystallization method, which comprises the following steps: dissolving an alkali-resistant disperse dye solid in a low-boiling-point solvent, ultrasonically heating to destroy the crystal structure of the dye, and filtering to obtain a dye solution; dissolving a crystal control agent and a dispersing agent in a high-boiling-point solvent to obtain an anti-solvent; slowly adding the dye solution into the anti-solvent, stirring, cooling, and removing the low-boiling-point solvent after dye crystals are stable; the anti-solvent method is applied to preparation of the alkali-resistant liquid disperse dye for the first time, and compared with a traditional grinding method, the method has the advantages of low energy consumption, simple equipment and less pollution; the prepared alkali-resistant liquid disperse dye has the advantages that the particle size can be as low as 130nm, the storage stability is good, the deep dyeing property is improved compared with that of the conventional alkali-resistant liquid disperse dye, the dye utilization rate is high, the dyeing soaping fastness is higher than level 4, the dyeing COD value is reduced compared with that of the conventional dye with the same strength, the use is convenient, and the dyeing process is simplified.

Description

Technical Field

[0001] The invention relates to the technical field of disperse dye preparation, and in particular to a method for preparing alkali-resistant liquid disperse dye without grinding and with low energy consumption. Background Art

[0002] With the development of technology, a series of benzene, benzothiazole, and benzisothiazole disperse dyes with different gradients of alkali resistance and oxidation resistance have been obtained through the introduction of different substituents. A series of alkali-resistant disperse dyes have been put into research and production. Alkali-resistant disperse dyes have high resistance to oxygen bleaching and oxidation, which can shorten the process flow and processing time and improve production efficiency.

[0003] Disperse dyes are mainly stored in powder and liquid form. Traditional powdered solid disperse dyes need to go through a spray drying process, which requires large equipment space, large investment, large energy consumption, and high production costs; and the amount of dispersant used is large. In recent years, with the advancement of automatic batching and energy-saving and emission reduction technology in printing and dyeing, as well as in-depth research on the preparation and application technology of liquid disperse dyes, the advantages of liquid disperse dyes have gradually become prominent: no spray drying is required during preparation; no chemical materials are required during application, there is no dust pollution, and it is easy to adjust the pulp or prepare the dye solution; due to the low amount of auxiliaries, the dye migration phenomenon is light during continuous pad dyeing, less surface floating color during high-temperature immersion dyeing, light color of dyeing wastewater, and high dye utilization rate; no water washing is required during printing.

[0004] Compared with traditional disperse dye packaging, the preparation process of liquid disperse dyes omits the intermediate spray drying process, saving energy; reduces dust pollution, and the production process is more environmentally friendly; the dye utilization rate is high, which reduces the treatment cost of dye wastewater. However, liquid disperse dyes still have problems such as poor grinding energy efficiency during preparation and large fluctuations in dye particle size during storage or long-distance transportation. There are two main ways to prepare nanosuspensions. One is a top-down method, such as high-pressure homogenization or media grinding. The other is a bottom-up method, such as anti-solvent crystallization. The top-down media grinding method is widely used in the preparation of alkali-resistant liquid disperse dyes. This method requires a lot of energy for grinding, and the grinding efficiency is low, and it takes a long time to process. The anti-solvent crystallization method has the advantages of low energy consumption and short preparation cycle. Current research is mainly focused on drug and pesticide research, which can improve the application performance of drug and pesticide suspensions. The antisolvent method is rarely used in the preparation of liquid alkali-resistant disperse dyes. Firstly, some dyes cannot be well dissolved in low-boiling point solvents, resulting in the inability to undergo antisolvent crystallization. Secondly, some dyes may exhibit better color intensity, color fastness and dispersibility when prepared by other methods (such as mechanical stirring, high-pressure homogenization, medium grinding, etc.). Summary of the invention

[0005]

Technical issues

[0006] Alkali-resistant disperse dyes have high resistance to oxygen bleaching and oxidation, can shorten the process and processing time, and improve production efficiency. The production process of liquid disperse dyes is environmentally friendly, easy to use and operate, and can improve dyeing performance. The anti-solvent crystallization method has low energy consumption and a short preparation cycle. However, the preparation of liquid alkali-resistant disperse dyes by the reverse crystallization method has problems with poor color intensity, color fastness, and dispersibility. A reverse crystallization preparation method for liquid alkali-resistant disperse dyes with excellent color intensity, color fastness, and dispersibility is needed.

[0007]

Technical solution

[0008] The first object of the present invention is to provide a method for preparing alkali-resistant liquid disperse dyes by anti-solvent crystallization, comprising the steps of:

[0009] (1) Destruction of dye crystals: dissolving alkali-resistant disperse dye solids in a low-boiling point solvent, ultrasonically heating, and filtering to obtain a dye solution;

[0010] (2) Controlling the particle size of dye crystals: dissolving a crystal control agent and a dispersant in a high boiling point solvent to obtain an anti-solvent; slowly adding the dye solution to the anti-solvent, stirring, cooling, and removing the low boiling point solvent to obtain an alkali-resistant liquid disperse dye.

[0011] In one embodiment of the present invention, in step (1), the alkali-resistant disperse dye solid is an alkali-resistant disperse dye filter cake; the effective content of the alkali-resistant disperse dye filter cake is 0.5-5% w / w, and the solid content is 1-10% w / w.

[0012] The effective content is the content of the alkali-resistant disperse dye in the alkali-resistant disperse dye filter cake, and the solid content is the content of the remaining part of the alkali-resistant disperse dye filter cake after drying.

[0013] In one embodiment of the present invention, in step (1), the concentration of the alkali-resistant disperse dye in the dye solution is 5 to 50 mg / L.

[0014] In one embodiment of the present invention, the alkali-resistant disperse dye is selected from one or more of the following formulas I, II, and III:

[0015]

[0016] In formula I, R1 is a C1-5 alkyl or alkoxy group;

[0017] In formula II, R2 is -H, C1-5 alkyl, benzyl, phenethyl, phenylpropyl, p-methylbenzyl or m-methylbenzyl;

[0018] In formula III, R3 is -H, C1-5 alkyl or C1-5 alkoxy; R4 is C1-5 alkyl, benzyl, phenethyl, phenylpropyl, p-methylbenzyl or m-methylbenzyl.

[0019] In one embodiment of the present invention, the alkali-resistant disperse dye is selected from one or more of Ⅰ, Ⅱ, and Ⅲ;

[0020] In formula Ⅰ, R1 is -CH3 or -OCH3;

[0021] In formula II, R2 is -H, -CH3, benzyl, p-methylbenzyl or m-methylbenzyl;

[0022] In formula III, R3 is -H, -CH3 or -OCH3; R4 is -C2H5, benzyl, p-methylbenzyl or m-methylbenzyl.

[0023] In one embodiment of the present invention, in step (1), the low boiling point solvent is one or more of ethanol (EA), acetone (CP), ethyl acetate (EAC), dichloromethane (DCM), and tetrahydrofuran (THF).

[0024] In one embodiment of the present invention, in step (1), the temperature of ultrasonic heating is 25-35°C.

[0025] In one embodiment of the present invention, in step (1), the filtering method is filtering using a 0.45 μm organic filter membrane to remove impurities and incompletely dissolved components in the dye solution.

[0026] In one embodiment of the present invention, in step (2), the crystal controller is a naphthalene polymer having the following structure:

[0027]

[0028] Wherein, the X group is amino, methyl or -H; a, b, c, n are 1 to 100 respectively; R1 is an alkyl group having 1 to 18 carbon atoms; and R2 is -H or -CH3.

[0029] In one embodiment of the present invention, in step (2), the dispersant is one or more of sodium lignin sulfonate, sodium methylene bisnaphthalene sulfonate (NNO), sodium methylene bismethylnaphthalene sulfonate (MF), fatty alcohol polyoxyethylene ether, and fatty amine polyoxyethylene ether.

[0030] In one embodiment of the present invention, in step (2), the high boiling point solvent is one or more of water, liquid paraffin, decamethylcyclopentasiloxane, a choline chloride-urea mixture, and a betaine-thiourea mixture.

[0031] In one embodiment of the present invention, in step (2), the crystal controller concentration of the antisolvent is 2 to 50 mg / mL, the dispersant concentration is 3 to 50 mg / mL, and the volume ratio of the dye solution to the antisolvent is 1 to 10:10.

[0032] In one embodiment of the present invention, in step (2), the cooling is performed by cooling the temperature to 2-10° C. using an ice bath.

[0033] The second object of the present invention is to provide an alkali-resistant liquid disperse dye prepared by the above method.

[0034] In one embodiment of the present invention, the components of the alkali-resistant liquid disperse dye are: 0.5-50 mg / L of alkali-resistant disperse dye, 1-50 mg / mL of dispersant, 1-50 mg / mL of crystal controller, and a high boiling point solvent.

[0035] The third object of the present invention is to provide applications of the alkali-resistant liquid disperse dyes, including dyeing of synthetic fibers and textiles thereof, printing of synthetic fiber textiles, and preparation of ultrafine disperse dye inks.

[0036] Beneficial effects:

[0037] Compared with the existing alkali-resistant liquid disperse dye preparation technology, the present invention provides a method for preparing alkali-resistant liquid disperse dyes without grinding, which is a high energy consumption mode, and has the following beneficial effects:

[0038] There is no high-energy-consuming and high-pollution step of grinding in the preparation process, and the required equipment is simple, without the need for large and complex equipment such as high-pressure homogenizers and sand mills.

[0039] Compared with alkali-resistant powder disperse dyes, the prepared alkali-resistant liquid disperse dyes have high storage stability, good level dyeing, good dyeing depth, low COD value of dyeing wastewater and high dye utilization rate.

[0040] Compared with alkali-resistant powder disperse dyes, the prepared alkali-resistant liquid disperse dyes have smaller particle size, with the minimum reaching 130nm, providing new ideas for the preparation of disperse dye inks.

[0041] The grinding method can make some alkali-resistant disperse dyes show better color strength, color fastness and dispersibility, and the alkali-resistant liquid disperse dye prepared by the present invention also has excellent color strength, color fastness and dispersibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the stability particle size of Example 1.

[0043] Figure 2 Schematic diagram of particle size and Zeta potential of alkali-resistant liquid disperse dye in Example 1. DETAILED DESCRIPTION

[0044] Test Method

[0045] Storage stability: The prepared alkali-resistant liquid disperse dye suspension was stored at room temperature for 30 days, and its particle size and Zeta potential were tested after 7 days and 30 days.

[0046] K / S value: The dyed fabric is measured using a Datacolor 800 colorimeter with a D65 light source and a 10° observation angle to determine the K / S value of the fabric sample. The measurement is performed 4 times at different locations of the fabric sample and the average value is taken.

[0047] Dye uptake: Use a UV spectrophotometer to test the absorbance of the dye solution before and after dyeing, and calculate the concentration and dye uptake by making a standard curve.

[0048] COD value: Use DGB-401 multi-parameter water quality analyzer to measure the COD value of the residual liquid after dyeing with powder and liquid disperse dyes at the same dyeing concentration, and refer to GB / T 18885-2009 for comparison.

[0049] Washing fastness: refer to GB / T 3921-2008 "Textiles - Tests for Colour Fastness - Colour Fastness to Washing" to determine the colour fastness of dyed fabrics to washing with soap.

[0050] Example 1

[0051] An alkali-resistant liquid disperse dye, the preparation method is:

[0052] (1) Destruction of dye crystals: 50 mg of alkali-resistant disperse dye filter cake (Ⅰ, R1 = -CH3) was dissolved in 10 mL of acetone (AC), ultrasonically heated to 30°C, and filtered with a 0.45 μm organic filter membrane to obtain a dye solution; the effective content of the alkali-resistant disperse dye filter cake was 0.5% w / w, and the solid content was 1% w / w.

[0053] (2) Control of the particle size of dye crystals: 25 mg of a naphthalene polymer (R1 = -CH3, R2 = -H, X = -NH2, a = 1, b = 1, c = 1, n = 1), 25 mg of sodium methylene bis-naphthalene sulfonate (NNO) and 25 mg of octadecylamine polyoxyethylene ether 1820 were dissolved in 10 mL of water to obtain an anti-solvent; the anti-solvent was placed at 4°C and magnetically stirred at 800 rpm, and 10 mL of the dye solution was slowly added to 10 mL of the anti-solvent, stirred for 4 h, cooled to 4°C in an ice bath, and the low-boiling point solvent was removed by rotary evaporation to obtain an alkali-resistant liquid disperse dye.

[0054] Alkali-resistant liquid disperse dye dyeing method:

[0055] A standard cloth cutting machine was used to accurately cut out a 1.0 g polyester plain woven fabric sample, and the dyed fabric was obtained by high temperature and high pressure dyeing, reduction cleaning, and washing.

[0056] High temperature and high pressure dyeing process: prepare dye solution (alkali-resistant liquid disperse dye 5% owf, leveling agent concentration is 3wt% of dye solution, bath ratio 1:50, dye solution pH = 4.5) → heat up (4℃ / min quickly heat up to 80℃, 1℃ / min slowly heat up to 130℃ dyeing for 1h) → keep warm (cool down to 80℃ and keep warm for 30min)

[0057] Reduction cleaning, water washing: hydrosulfite 2g / L, Na2CO3 4g / L, bath ratio 1:80, 80℃ reduction cleaning for 30min, wash away floating color. Bath ratio 1:20, 80℃ hot water washing, 25℃ cold water washing for 15min each.

[0058] Example 2

[0059] An alkali-resistant liquid disperse dye, the preparation method is:

[0060] (1) Destruction of dye crystals: 50 mg of alkali-resistant disperse dye filter cake (II, R2 = -CH3) was dissolved in 10 mL of acetone (AC), ultrasonically heated to 30°C, and filtered with a 0.45 μm organic filter membrane to obtain a dye solution; the effective content of the alkali-resistant disperse dye filter cake was 0.5% w / w, and the solid content was 1% w / w.

[0061] (2) Control of the particle size of dye crystals: 25 mg of a naphthalene polymer (R1 = -CH3, R2 = -H, X = -NH2, a = 1, b = 1, c = 1, n = 1), 25 mg of sodium methylene bis-naphthalene sulfonate (NNO) and 25 mg of octadecylamine polyoxyethylene ether 1820 were dissolved in 10 mL of water to obtain an anti-solvent; the anti-solvent was placed at 4°C and magnetically stirred at 800 rpm, and 10 mL of the dye solution was slowly added to 10 mL of the anti-solvent, stirred for 4 h, cooled to 4°C in an ice bath, and the low-boiling point solvent was removed by rotary evaporation to obtain an alkali-resistant liquid disperse dye.

[0062] Alkali-resistant liquid disperse dye dyeing method:

[0063] A standard cloth cutting machine was used to accurately cut out a 1.0 g polyester plain woven fabric sample, and the dyed fabric was obtained by high temperature and high pressure dyeing, reduction cleaning, and washing.

[0064] High temperature and high pressure dyeing process: prepare dye solution (alkali-resistant liquid disperse dye 5% owf, leveling agent concentration is 3wt% of dye solution, bath ratio 1:50, dye solution pH = 4.5) → heat up (4℃ / min quickly heat up to 80℃, 1℃ / min slowly heat up to 130℃ dyeing for 1h) → keep warm (cool down to 80℃ and keep warm for 30min)

[0065] Reduction cleaning, water washing: hydrosulfite 2g / L, Na2CO3 4g / L, bath ratio 1:80, 80℃ reduction cleaning for 30min, wash away floating color. Bath ratio 1:20, 80℃ hot water washing, 25℃ cold water washing for 15min each.

[0066] Example 3

[0067] An alkali-resistant liquid disperse dye, the preparation method is:

[0068] (1) Destruction of dye crystals: 50 mg of alkali-resistant disperse dye filter cake (III, R3 = -CH3) was dissolved in 10 mL of acetone (AC), ultrasonically heated to 30°C, and filtered with a 0.45 μm organic filter membrane to obtain a dye solution; the effective content of the alkali-resistant disperse dye filter cake was 0.5% w / w, and the solid content was 1% w / w.

[0069] (2) Control of the particle size of dye crystals: 25 mg of a naphthalene polymer (R1 = -CH3, R2 = -H, X = -NH2, a = 1, b = 1, c = 1, n = 1), 25 mg of sodium methylene bis-naphthalene sulfonate (NNO) and 25 mg of octadecylamine polyoxyethylene ether 1820 were dissolved in 10 mL of water to obtain an anti-solvent; the anti-solvent was placed at 4°C and magnetically stirred at 800 rpm, and 10 mL of the dye solution was slowly added to 10 mL of the anti-solvent, stirred for 4 h, cooled to 4°C in an ice bath, and the low-boiling point solvent was removed by rotary evaporation to obtain an alkali-resistant liquid disperse dye.

[0070] Alkali-resistant liquid disperse dye dyeing method:

[0071] A standard cloth cutting machine was used to accurately cut out a 1.0 g polyester plain woven fabric sample, and the dyed fabric was obtained by high temperature and high pressure dyeing, reduction cleaning, and washing.

[0072] High temperature and high pressure dyeing process: prepare dye solution (alkali-resistant liquid disperse dye 5% owf, leveling agent concentration is 3wt% of dye solution, bath ratio 1:50, dye solution pH = 4.5) → heat up (4℃ / min quickly heat up to 80℃, 1℃ / min slowly heat up to 130℃ dyeing for 1h) → keep warm (cool down to 80℃ and keep warm for 30min)

[0073] Reduction cleaning, water washing: hydrosulfite 2g / L, Na2CO3 4g / L, bath ratio 1:80, 80℃ reduction cleaning for 30min, wash away floating color. Bath ratio 1:20, 80℃ hot water washing, 25℃ cold water washing for 15min each.

[0074] Example 4

[0075] An alkali-resistant liquid disperse dye, the preparation method is:

[0076] (1) Destruction of dye crystals: 50 mg of alkali-resistant disperse dye filter cake (Ⅰ, R1 = -CH3) was dissolved in 10 mL of dichloromethane (DCM), ultrasonically heated to 30°C, and filtered with a 0.45 μm organic filter membrane to obtain a dye solution; the effective content of the alkali-resistant disperse dye filter cake was 0.5% w / w, and the solid content was 1% w / w.

[0077] (2) Control of the particle size of dye crystals: 25 mg of a naphthalene polymer (R1 = -CH3, R2 = -H, X = -NH2, a = 1, b = 1, c = 1, n = 1), 25 mg of sodium methylene bis-naphthalene sulfonate (NNO) and 25 mg of octadecylamine polyoxyethylene ether 1820 were dissolved in 10 mL of water to obtain an anti-solvent; the anti-solvent was placed at 4°C and magnetically stirred at 800 rpm, and 10 mL of the dye solution was slowly added to 10 mL of the anti-solvent, stirred for 4 h, cooled to 4°C in an ice bath, and the low-boiling point solvent was removed by rotary evaporation to obtain an alkali-resistant liquid disperse dye.

[0078] Alkali-resistant liquid disperse dye dyeing method:

[0079] A standard cloth cutting machine was used to accurately cut out a 1.0 g polyester plain woven fabric sample, and the dyed fabric was obtained by high temperature and high pressure dyeing, reduction cleaning, and washing.

[0080] High temperature and high pressure dyeing process: prepare dye solution (alkali-resistant liquid disperse dye 5% owf, leveling agent concentration is 3wt% of dye solution, bath ratio 1:50, dye solution pH = 4.5) → heat up (4℃ / min quickly heat up to 80℃, 1℃ / min slowly heat up to 130℃ dyeing for 1h) → keep warm (cool down to 80℃ and keep warm for 30min)

[0081] Reduction cleaning, water washing: hydrosulfite 2g / L, Na2CO3 4g / L, bath ratio 1:80, 80℃ reduction cleaning for 30min, wash away floating color. Bath ratio 1:20, 80℃ hot water washing, 25℃ cold water washing for 15min each.

[0082] Example 5

[0083] An alkali-resistant liquid disperse dye, the preparation method is:

[0084] (1) Destruction of dye crystals: 50 mg of alkali-resistant disperse dye filter cake (Ⅰ, R1 = -OCH3) was dissolved in 10 mL of acetone (AC), ultrasonically heated to 30°C, and filtered with a 0.45 μm organic filter membrane to obtain a dye solution; the effective content of the alkali-resistant disperse dye filter cake was 0.5% w / w, and the solid content was 1% w / w.

[0085] (2) Control of the particle size of dye crystals: 25 mg of a naphthalene polymer (R1 = -CH3, R2 = -H, X = -NH2, a = 1, b = 1, c = 1, n = 1), 25 mg of sodium methylene bis-naphthalene sulfonate (NNO) and 25 mg of octadecylamine polyoxyethylene ether 1820 were dissolved in 10 mL of water to obtain an anti-solvent; the anti-solvent was placed at 4°C and magnetically stirred at 800 rpm, and 10 mL of the dye solution was slowly added to 10 mL of the anti-solvent, stirred for 4 h, cooled to 4°C in an ice bath, and the low-boiling point solvent was removed by rotary evaporation to obtain an alkali-resistant liquid disperse dye.

[0086] Alkali-resistant liquid disperse dye dyeing method:

[0087] A standard cloth cutting machine was used to accurately cut out a 1.0 g polyester plain woven fabric sample, and the dyed fabric was obtained by high temperature and high pressure dyeing, reduction cleaning, and washing.

[0088] High temperature and high pressure dyeing process: prepare dye solution (alkali-resistant liquid disperse dye 5% owf, leveling agent concentration is 3wt% of dye solution, bath ratio 1:50, dye solution pH = 4.5) → heat up (4℃ / min quickly heat up to 80℃, 1℃ / min slowly heat up to 130℃ dyeing for 1h) → keep warm (cool down to 80℃ and keep warm for 30min)

[0089] Reduction cleaning, water washing: hydrosulfite 2g / L, Na2CO3 4g / L, bath ratio 1:80, 80℃ reduction cleaning for 30min, wash away floating color. Bath ratio 1:20, 80℃ hot water washing, 25℃ cold water washing for 15min each.

[0090] The particle size, Zeta potential, K / S value, dye uptake, COD value, and soap fastness of the alkali-resistant liquid disperse dye prepared in the embodiment are shown in Table 1.

[0091] Table 1

[0092]

[0093]

[0094] The results show that the present invention can prepare alkali-resistant liquid disperse dyes with small particle size and good storage stability. The soap fastness of the dyeing in the embodiment is above grade 4, the dyeing depth is improved by 40% compared with the conventional alkali-resistant liquid disperse dyes, and the COD value of dyeing with the same strength powder dye is reduced by 30%. And because of its alkali resistance, the dyeing process can be shortened and energy consumption can be reduced. The alkali-resistant liquid disperse dye prepared by this method is easy to use, has good application prospects, and provides a new method for optimizing the preparation process of alkali-resistant liquid disperse dyes.

[0095] Comparative Example 1

[0096] An alkali-resistant disperse dye solution, the preparation method is as follows:

[0097] The difference from Example 1 is that the low boiling point solvent is acetonitrile.

[0098] The filter cake has low solubility in acetonitrile and is prone to aggregation when using anti-solvent crystallization, resulting in low solvent utilization. Acetonitrile cannot be used as a solvent for the preparation of alkali-resistant liquid disperse dyes by anti-solvent crystallization.

[0099] Comparative Example 2

[0100] An alkali-resistant disperse dye solution, the preparation method is as follows:

[0101] The difference from Example 1 is that the low boiling point solvent is dimethyl sulfoxide.

[0102] Alkali-resistant disperse dye solution dyeing method:

[0103] The difference from Example 1 is that in the high temperature and high pressure dyeing process, the amount of alkali-resistant disperse dye solution in the dye liquor is 1% owf.

[0104] The dye has high solubility in dimethyl sulfoxide, but the boiling point of dimethyl sulfoxide is too high to be removed by rotary evaporation. It will remain in the dye solution, causing difficulties in subsequent dyeing. It cannot be used as a solvent for preparing alkali-resistant liquid disperse dyes by the anti-solvent crystallization method.

[0105] Comparative Example 3

[0106] An alkali-resistant disperse dye solution, the preparation method is as follows:

[0107] The difference from Example 1 is that the low boiling point solvent is chloroform.

[0108] Chloroform as an anti-solvent is immiscible with solvent water, and stratification occurs after mixing. It cannot be used as an anti-solvent to prepare alkali-resistant liquid disperse dyes. Dyeing is impossible.

[0109] Comparative Example 4

[0110] An alkali-resistant disperse dye solution, the preparation method is as follows:

[0111] The difference from Example 1 is that sorbitan monooleate is used as the dispersant.

[0112] Alkali-resistant disperse dye solution dyeing method:

[0113] The difference from Example 1 is that in the high temperature and high pressure dyeing process, the amount of alkali-resistant disperse dye solution in the dye liquor is 1% owf.

[0114] The prepared alkali-resistant liquid disperse dye solution has a particle size of 850.13 nm, poor dispersibility, poor stability, and poor level dyeing.

[0115] Comparative Example 5

[0116] An alkali-resistant disperse dye solution, the preparation method is as follows:

[0117] The difference from Example 1 is that polyvinyl pyrrolidone is used as the dispersant.

[0118] Alkali-resistant disperse dye solution dyeing method:

[0119] Same as Example 1.

[0120] The prepared liquid disperse dye solution has an initial particle size of 578.65 nm, poor stability, poor levelness, and cannot be used for dyeing.

[0121] Comparative Example 6

[0122] An alkali-resistant disperse dye solution, the preparation method is as follows:

[0123] The difference from Example 1 is that sodium methylenebisnaphthalene sulfonate (NNO) is replaced by sodium dodecylbenzene sulfonate.

[0124] Alkali-resistant disperse dye solution dyeing method:

[0125] Same as Example 1.

[0126] The difference from Example 1 is that in the high temperature and high pressure dyeing process, the amount of alkali-resistant disperse dye solution in the dye liquor is 2% owf.

[0127] The prepared alkali-resistant disperse dye solution has a particle size of 523.98 nm, poor levelness and stability.

[0128] Comparative Example 7

[0129] An alkali-resistant liquid disperse dye solution, the preparation method is:

[0130] The difference from Example 1 is that the alkali-resistant disperse dye used has the following structure:

[0131]

[0132] The dye filter cake has very low solubility in acetone, and dye aggregation easily occurs when the dye solution is mixed with a high-boiling point anti-solvent. This alkali-resistant disperse dye filter cake cannot be used to prepare alkali-resistant liquid disperse dyes by the anti-solvent method.

[0133] The particle size, Zeta potential, K / S value, dye uptake, COD value and soap fastness of the alkali-resistant disperse dye solution prepared in the comparative example are shown in Table 2.

[0134] Table 2

[0135]

[0136]

[0137] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing alkali-resistant liquid disperse dyes by anti-solvent crystallization, characterized in that: Includes steps: (1) Destruction of dye crystals: dissolving alkali-resistant disperse dye solids in a low-boiling point solvent, ultrasonically heating, and filtering to obtain a dye solution; (2) Controlling the particle size of dye crystals: dissolving a crystal control agent and a dispersant in a high boiling point solvent to obtain an anti-solvent; adding the dye solution to the anti-solvent, stirring, cooling, and removing the low boiling point solvent to obtain an alkali-resistant liquid disperse dye.

2. The method according to claim 1, characterized in that In step (1), the concentration of the alkali-resistant disperse dye in the dye solution is 5 to 50 mg / L; and the temperature of ultrasonic heating is 25 to 35°C.

3. The method according to any one of claims 1 to 2, characterized in that: The alkali-resistant disperse dye is selected from one or more of the following formulas I, II, and III: In formula I, R1 is a C1-5 alkyl or alkoxy group; In formula II, R2 is -H, C1-5 alkyl, benzyl, phenethyl, phenylpropyl, p-methylbenzyl or m-methylbenzyl; In formula III, R3 is -H, C1-5 alkyl or C1-5 alkoxy; R4 is C1-5 alkyl, benzyl, phenethyl, phenylpropyl, p-methylbenzyl or m-methylbenzyl.

4. The method according to claim 1, characterized in that In step (1), the low boiling point solvent is one or more of ethanol, acetone, ethyl acetate, dichloromethane and tetrahydrofuran.

5. The method according to claim 1, characterized in that In step (2), the crystal controller is a naphthalene polymer having the following structure: Wherein, the X group is amino, methyl or -H; a, b, c, n are 1 to 100 respectively; R1 is an alkyl group having 1 to 18 carbon atoms; and R2 is -H or -CH3.

6. The method according to claim 1, characterized in that In step (2), the dispersant is one or more of sodium lignin sulfonate, sodium methylene bisnaphthalene sulfonate, sodium methylene bismethylnaphthalene sulfonate, fatty alcohol polyoxyethylene ether, and fatty amine polyoxyethylene ether.

7. The method according to claim 1, characterized in that In step (2), the high boiling point solvent is one or more of water, liquid paraffin, decamethylcyclopentasiloxane, choline chloride-urea mixture, and betaine-thiourea mixture.

8. The method according to claim 1, characterized in that In step (2), the crystal controller concentration of the antisolvent is 2-50 mg / mL, and the dispersant concentration is 3-50 mg / mL; the volume ratio of the dye solution to the high boiling point antisolvent is 1-10:10; and the cooling is performed by cooling in an ice bath to 2-10°C.

9. Alkali-resistant liquid disperse dye obtained by the method according to any one of claims 1 to 8.

10. Application of the alkali-resistant liquid disperse dye according to claim 9, including dyeing of synthetic fibers and textiles thereof, printing of synthetic fiber textiles, and preparation of ultrafine disperse dye ink.

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