A process for the production of a dispersion of orange 30

Abstract

The application discloses a production process of dispersed orange 30, and comprises the following steps: first, high-purity stable diazonium liquid is prepared through segmented gradient salt-free diazotization; then, an acetic acid-ammonia water buffer system is adopted, a rare earth catalyst is matched with an amphoteric betaine complex surfactant to realize dynamic controllable coupling; subsequently, PEG2000 is added to carry out micro-nano crystal reorganization and purification; gradient water washing and pressure filtration are carried out to obtain filter cake; finally, a dispersing agent is matched, and the filter cake is subjected to segmented sand milling, drying and screening to obtain a finished product. The rare earth catalyst and the amphoteric surfactant are used in cooperation to reduce coupling by-products, and PEG2000 is used to regulate the crystal form of the dye and remove wrapped impurities. The finished product produced by the process has high purity, high comprehensive yield and high relative intensity of the original dye.

Description

Technical Field

[0001] This invention relates to the field of dye synthesis technology, and in particular to a production process for Disperse Orange 30. Background Technology

[0002] Disperse Orange 30 is an anthraquinone disperse dye characterized by its bright color, high lightfastness, and excellent sublimation fastness. It is widely used in dyeing and direct printing of polyester-cotton and polyester-viscose blended products and is an indispensable basic color tone for polyester fiber dyeing. Currently, with the upgrading of textile products towards high-end, functional, and green products, the market's requirements for the color stability, batch consistency, weather fastness, low impurity residue, and low-salt environmentally friendly production indicators of Disperse Orange 30 products are continuously increasing.

[0003] The current mainstream industrial production process for Disperse Orange 30 uses 2,6-dichloro-4-nitroaniline as the diazo precursor, preparing a diazonium salt through a diazotization reaction, followed by a coupling reaction with N-acetoxyethyl-N-cyanoethylaniline. The final product is obtained through simple filtration, grinding, and drying. This process route uses readily available raw materials and has a mature reaction mechanism, making it a widely used basic production process in the industry. However, in traditional production processes, insufficient control precision in the diazotization and coupling reactions results in a significant amount of tar-like impurities and unreacted intermediates in the product. This leads to poor alkali resistance in the final product, making the dyed goods prone to color changes during subsequent processing or use. Furthermore, the uneven distribution of dye particles affects the dyeing effect. In addition, Disperse Orange 30 produced using traditional mass production processes often suffers from crystal structure defects, residual trace organic impurities, large batch-to-batch color variations, and insufficient color fastness in high-weather conditions. Moreover, the production process generates high levels of waste gas, wastewater, and solid waste, making it difficult to meet the stringent standards and green chemical production policies of current high-end textile printing and dyeing industries.

[0004] For example, the invention patent document CN102618061A discloses a method for preparing Disperse Orange 30, including (1) diazotization reaction: 2,6-dichloro-p-nitroaniline is diazotized with nitrosylsulfuric acid in a sulfuric acid medium to obtain a diazo product solution; (2) coupling reaction: the diazo product solution obtained in step (1) is coupled with N-cyanoethyl-N-acetoxyethyl to generate Disperse Orange 30. The chromatographic content of the raw material 2,6-dichloro-p-nitroaniline used in step (1) is above 99.8 wt%, and the content of polychlorinated biphenylamine is below 5 ppm. The diazotization reaction is carried out at a temperature of 0-5℃. The product obtained by this invention method does not contain the internationally banned byproduct polychlorinated biphenylamine, which lays the foundation for opening up the international market; in addition, the yield of the obtained product is high, the purity is high, and the color is bright. However, it only optimized the process from the perspective of raw material selection and simple temperature control, without making any changes to the reaction system, crystal structure, and post-processing refining core processes. As a result, there are still obvious shortcomings in the overall performance of the product and the controllability of the process. Summary of the Invention

[0005] To overcome the defects in the above-mentioned technologies, the present invention provides a production process for Disperse Orange 30, which effectively improves product purity, yield and color fastness, and reduces emissions of waste through segmented gradient diazotization, dynamic buffer coupling, crystal form modification and purification, and graded sand milling.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a production process for Disperse Orange 30, comprising the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to -2 to 0℃, add 2,6-dichloro-4-nitroaniline to swell for 40 to 50 min, add nitrite sulfuric acid solution with a mass percentage concentration of 40% to 45% in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.1-4.3. Diazo solution is added dropwise from bottom to top at 6-9℃, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 45-48℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 36% to 39%. The slurry is coarsely ground and finely ground at 22 to 28°C, filtered, vacuum dried and sieved to obtain the Disperse Orange 30 finished product.

[0007] Preferably, the mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution in step S1 is 1:(4.6-4.9):(1.3-1.4).

[0008] Preferably, the segmentation in step S1 specifically involves: adding 60%–70% of the total mass of nitrosylsulfuric acid solution at -2–2°C for 0.8–1.2 hours; adding the remaining nitrosylsulfuric acid solution at 3–5°C for 0.4–0.6 hours; maintaining the temperature at 0–3°C for 0.8–1.2 hours; and maintaining the temperature at 3–5°C for 1.4–1.6 hours.

[0009] Preferably, the compound solvent in step S2 is prepared by compounding deionized water, methanol, and ethanol in a mass ratio of (4.8-5.2):(1.7-1.9):0.4.

[0010] Preferably, the two-component buffer system in step S2 is composed of acetic acid, ammonia, and deionized water in a mass ratio of 2.5:1:10; the mass percentage concentration of the ammonia is 24%-26%.

[0011] Preferably, the mass ratio of N-acetoxyethyl-N-cyanoethyl aniline, compound solvent, acetic acid-ammonia water two-component buffer system, rare earth catalyst, amphoteric surfactant and diazonium solution in step S2 is 100:(700~750):(21~23):(0.4~0.5):(0.5~0.7):252.

[0012] Preferably, the rare earth catalyst in step S2 is a mixture of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:(0.8-1.2); the amphoteric surfactant is a mixture of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:(0.8-1.2).

[0013] Preferably, the heat preservation reaction time in step S2 is 2-4 hours, and the temperature for heating and ripening is 10°C for 1.5-2.5 hours.

[0014] Preferably, the mass ratio of the crude dye solution and the PEG2000 crystal form regulator in step S3 is (4200-4250):1.

[0015] Preferably, the temperature for microcrystalline reforming in step S3 is 45–48°C, and the holding time is 58–62 min; the time for isothermal stratification is 118–122 min.

[0016] Preferably, the gradient temperature of the water washing in step S3 is 35℃, 40℃, and 45℃ respectively, and the washing and stirring time is 18-22 min and the settling time is 28-32 min; the plate and frame filter press pressure is 0.35-0.4 MPa and the time is 2.3-2.8 h.

[0017] Preferably, the compound dispersant in step S4 is a mixture of dispersant NF, sodium lignosulfonate, and dispersant SN-5040 in a mass ratio of 5:(2-3):(1.5-2.5).

[0018] Preferably, the amount of the compound dispersant added is 8.5% to 9.5% of the weight of the filter cake.

[0019] Preferably, the coarse grinding in step S4 is performed at a speed of 1900-2100 r / min for 1.5-2.5 h; the fine grinding is performed at a speed of 3050-3150 r / min for 2.5-3.5 h, with the temperature controlled at 22-28℃ throughout the process.

[0020] Preferably, the vacuum drying temperature in step S4 is 54-56°C and the drying time is 8-9 hours; the sieving is performed using a 400-mesh filter.

[0021] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The production process of Disperse Orange 30 disclosed in this invention adopts segmented dropwise and segmented gradient salt-free diazotization, combined with a specific ratio of concentrated sulfuric acid and raw material system. Based on the kinetic characteristics of the diazotization reaction being intense in the early stage and gradual in the later stage, the low temperature stage suppresses side reactions and the medium temperature stage promotes the complete reaction of raw materials. It can effectively avoid the decomposition and coupling side reactions caused by local excess nitrous acid and sudden temperature changes, greatly suppress the generation of impurities, improve the storage and reaction stability of diazo product liquid, and effectively solve the problems of large batch color difference and low raw material conversion rate in traditional processes.

[0022] (2) The production process of Disperse Orange 30 disclosed in this invention uses rare earth compound catalyst to directionally activate the coupled amino groups and reduce the reaction energy barrier. It is combined with betaine amphoteric surfactant to solubilize and stabilize the catalyst and assist in the removal of impurities. Combined with acetic acid-ammonia water bidirectional dynamic buffer system, the triple synergistic effect effectively controls pH fluctuations, eliminates side reactions such as diazonium hydrolysis and coupling component isomerization, significantly reduces the amount of organic impurities generated, significantly improves the raw material reaction conversion rate, and significantly reduces coupling by-products. It effectively improves the synthesis quality and reaction yield of dye intermediates and ensures the consistency of the basic color of the product.

[0023] (3) The production process of Disperse Orange 30 disclosed in this invention introduces PEG2000 crystal form regulator to induce the rearrangement and reconstruction of dye microcrystals, transforming irregular defect crystals into dense and stable crystals, which greatly improves the dye molecules' resistance to photoaging and friction damage, and significantly improves the product's lightfastness. Combined with constant temperature layering impurity removal, gradient warm water washing, and plate and frame filter press purification technology, the product purity and batch consistency are further improved.

[0024] (4) The production process of Disperse Orange 30 disclosed in this invention adopts a graded sand milling mode of coarse grinding followed by fine grinding, which effectively solves the problems of uneven particle size, over-grinding, and insufficient grinding in traditional sand milling, resulting in excellent particle size uniformity of the finished product. At the same time, the low temperature control system protects the color development conjugate structure of the dye throughout the process, with no thermal degradation loss, significantly improving the color uniformity and color stability of the dye, and providing excellent dry and wet rubbing color fastness. Detailed Implementation

[0025] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0026] Example 1

[0027] A production process for Disperse Orange 30 includes the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to -2℃, add 2,6-dichloro-4-nitroaniline to swell for 40 min, add 40% nitrosyl sulfuric acid solution in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.1. Diazo solution is added dropwise from bottom to top at 6°C, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 45℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 36%. The slurry is coarsely ground and finely ground at 22°C, filtered, vacuum dried and sieved to obtain Disperse Orange 30 finished product.

[0028] In step S1, the mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution is 1:4.6:1.3. The segmented process in step S1 specifically involves: adding 60% of the total mass of nitrosylsulfuric acid solution dropwise at -2℃ for 0.8 hours; adding the remaining nitrosylsulfuric acid solution dropwise at 3℃ for 0.4 hours; maintaining the temperature at 0-3℃ for 0.8 hours; and maintaining the temperature at 3℃ for 1.4 hours. In step S2, the compound solvent is prepared by mixing deionized water, methanol, and ethanol in a mass ratio of 4.8:1.7:0.4. In step S2, the two-component buffer system is prepared by mixing acetic acid, ammonia, and deionized water in a mass ratio of 2.5:1:10; the mass percentage concentration of the ammonia is 24%.

[0029] In step S2, the mass ratio of N-acetoxyethyl-N-cyanoethyl aniline, the compound solvent, the acetic acid-ammonia water two-component buffer system, the rare earth catalyst, the amphoteric surfactant, and the diazonium solution is 100:700:21:0.4:0.5:252; the rare earth catalyst in step S2 is a compound of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:0.8; the amphoteric surfactant is a compound of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:0.8; the heat preservation reaction time in step S2 is 2 hours, and the temperature for ripening is 10°C for 1.5 hours; the mass ratio of the crude dye solution and the PEG2000 crystal form regulator in step S3 is 4200:1.

[0030] In step S3, the temperature for microcrystalline reforming is 45℃, and the holding time is 58 min; the time for constant temperature stratification is 118 min; the temperature gradient water washing in step S3 is 35℃, 40℃, and 45℃ respectively, with each washing and stirring lasting 18 min and followed by standing for 28 min; the plate and frame filter press pressure is 0.35 MPa, and the time is 2.3 h; in step S4, the compound dispersant is composed of dispersant NF, sodium lignosulfonate, and dispersant SN-5040 in a mass ratio of 5:2:1.5; the amount of the compound dispersant added is 8.5% of the weight of the filter cake; in step S4, the coarse grinding speed is 1900 r / min, and the grinding time is 1.5 h; the fine grinding speed is 3050 r / min, and the grinding time is 2.5 h, with the temperature controlled at 22℃ throughout; the vacuum drying temperature in step S4 is 54℃, and the drying time is 8 h; the sieving is done using a 400-mesh filter screen.

[0031] Example 2

[0032] A production process for Disperse Orange 30 includes the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to -1℃, add 2,6-dichloro-4-nitroaniline to swell for 43 min, add 42% nitrosyl sulfuric acid solution in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.2. Diazo solution is added dropwise from bottom to top at 7°C, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 46℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 37%. The slurry is coarsely ground and finely ground at 24°C, filtered, vacuum dried and sieved to obtain Disperse Orange 30 finished product.

[0033] In step S1, the mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution is 1:4.7:1.32. The segmented treatment in step S1 specifically involves: adding 63% nitrosylsulfuric acid solution at -1℃ for 0.9 hours, then adding the remaining nitrosylsulfuric acid solution at 3.5℃ for 0.45 hours; maintaining the temperature at 1℃ for 0.9 hours, and then at 3.5℃ for 1.45 hours. In step S2, the compound solvent is prepared by mixing deionized water, methanol, and ethanol in a mass ratio of 4.9:1.75:0.4. In step S2, the two-component buffer system is prepared by mixing acetic acid, ammonia, and deionized water in a mass ratio of 2.5:1:10; the mass percentage concentration of the ammonia is 24.5%.

[0034] In step S2, the mass ratio of N-acetyloxyethyl-N-cyanoethyl aniline, the compound solvent, the acetic acid-ammonia water two-component buffer system, the rare earth catalyst, the amphoteric surfactant, and the diazonium solution is 100:720:21.5:0.43:0.55:252; the rare earth catalyst in step S2 is a compound of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:0.9; the amphoteric surfactant is a compound of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:0.9; the heat preservation reaction time in step S2 is 2.5 h, the temperature for heating and ripening is 10 °C, and the time is 1.8 h; the mass ratio of the crude dye solution and the PEG2000 crystal form regulator in step S3 is 4220:1.

[0035] In step S3, the temperature for microcrystalline reforming is 46℃, and the holding time is 59 min; the time for constant temperature stratification is 119 min; the temperature gradient water washing in step S3 is 35℃, 40℃, and 45℃ respectively, with a single washing and stirring time of 19 min and a standing time of 29 min; the plate and frame filter press pressure is 0.37 MPa, and the time is 2.5 h; the compound dispersant in step S4 is a mixture of dispersant NF, sodium lignosulfonate, and dispersant SN-5040 in a mass ratio of 5:2.3:1.7; the amount of the compound dispersant added is 8.7% of the weight of the filter cake; the coarse grinding speed in step S4 is 1950 r / min, and the grinding time is 1.7 h; the fine grinding speed is 3080 r / min, and the grinding time is 2.8 h, with the temperature controlled at 24℃ throughout; the vacuum drying temperature in step S4 is 54.5℃, and the drying time is 8.3 h; the sieving is done using a 400-mesh filter screen.

[0036] Example 3

[0037] A production process for Disperse Orange 30 includes the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to -1℃, add 2,6-dichloro-4-nitroaniline to swell for 45 min, add 43% nitrosyl sulfuric acid solution in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.2. Diazo solution is added dropwise from bottom to top at 7.5℃, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 46.5℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 37.5%. The slurry is coarsely ground and finely ground at 25°C, filtered, vacuum dried and sieved to obtain Disperse Orange 30 finished product.

[0038] In step S1, the mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution is 1:4.8:1.35. The segmented steps in step S1 are as follows: 65% nitrosylsulfuric acid solution is added dropwise at 0°C for 1 hour; the remaining nitrosylsulfuric acid solution is added dropwise at 4°C for 0.5 hours; the mixture is kept at 2°C for 1 hour and at 4°C for 1.5 hours. In step S2, the compound solvent is prepared by mixing deionized water, methanol, and ethanol in a mass ratio of 5:1.8:0.4. In step S2, the two-component buffer system is prepared by mixing acetic acid, ammonia, and deionized water in a mass ratio of 2.5:1:10; the ammonia has a mass percentage concentration of 25%.

[0039] In step S2, the mass ratio of N-acetyloxyethyl-N-cyanoethyl aniline, the compound solvent, the acetic acid-ammonia water two-component buffer system, the rare earth catalyst, the amphoteric surfactant, and the diazonium solution is 100:730:22:0.45:0.6:252; the rare earth catalyst in step S2 is a compound of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:1; the amphoteric surfactant is a compound of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:1; the heat preservation reaction time in step S2 is 3 hours, and the temperature for ripening is 10°C for 2 hours; the mass ratio of the crude dye solution and the PEG2000 crystal form regulator in step S3 is 4230:1.

[0040] In step S3, the temperature for microcrystalline reforming is 46.5℃, and the holding time is 60 min; the time for constant temperature stratification is 120 min; the temperature gradient water washing in step S3 is 35℃, 40℃, and 45℃ respectively, with each washing and stirring lasting 20 min and followed by standing for 30 min; the plate and frame filter press pressure is 0.38 MPa, and the time is 2.5 h; in step S4, the compound dispersant is composed of dispersant NF, sodium lignosulfonate, and dispersant SN-5040 in a mass ratio of 5:2.5:2; the amount of the compound dispersant added is 9% of the weight of the filter cake; in step S4, the coarse grinding speed is 2000 r / min, and the grinding time is 2 h; the fine grinding speed is 3100 r / min, and the grinding time is 3 h, with the temperature controlled at 25℃ throughout; the vacuum drying temperature in step S4 is 55℃, and the drying time is 8.5 h; the sieving is done using a 400-mesh filter screen.

[0041] Example 4

[0042] A production process for Disperse Orange 30 includes the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to 0℃, add 2,6-dichloro-4-nitroaniline to swell for 48 min, add 44% nitrosyl sulfuric acid solution in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.2. Diazo solution is added dropwise from bottom to top at 8.5℃, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 47.5℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 38.5%. The slurry is coarsely ground and finely ground at 27°C, filtered, vacuum dried and sieved to obtain Disperse Orange 30 finished product.

[0043] In step S1, the mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution is 1:4.8:1.38. The specific steps in step S1 are as follows: 68% nitrosylsulfuric acid solution is added dropwise at 1°C for 1.1 hours; the remaining nitrosylsulfuric acid solution is added dropwise at 4.5°C for 0.55 hours; the mixture is then kept at 2°C for 1.1 hours and at 4.5°C for 1.55 hours. In step S2, the compound solvent is composed of deionized water, methanol, and ethanol in a mass ratio of 5:1. The mixture is prepared by mixing acetic acid, ammonia, and deionized water in a mass ratio of 1:1.85:0.4; the two-component buffer system in step S2 is prepared by mixing acetic acid, ammonia, and deionized water in a mass ratio of 2.5:1:10; the mass percentage concentration of the ammonia is 25.5%; the mass ratio of N-acetoxyethyl-N-cyanoethyl aniline, the mixed solvent, the acetic acid-ammonia two-component buffer system, the rare earth catalyst, the amphoteric surfactant, and the diazonium solution in step S2 is 100:740:22.5:0.48:0.65:252.

[0044] In step S2, the rare earth catalyst is a mixture of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:1.1; the amphoteric surfactant is a mixture of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:1.1; the heat preservation reaction time in step S2 is 3.5 h, the temperature for heating and ripening is 10 °C, and the time is 2.3 h; in step S3, the mass ratio of the crude dye solution and the PEG2000 crystal form regulator is 4240:1; the temperature for microcrystalline reforming in step S3 is 47.5 °C, and the heat preservation time is 61 min; the time for isothermal stratification is 121 min.

[0045] In step S3, the gradient temperature water washing temperature is 35℃, 40℃, and 45℃ respectively, with each washing and stirring lasting 21 minutes and followed by 31 minutes of settling. The plate and frame filter press pressure is 0.39 MPa, and the time is 2.7 hours. In step S4, the compound dispersant is composed of dispersant NF, sodium lignosulfonate, and dispersant SN-5040 in a mass ratio of 5:2.8:2.4. The amount of the compound dispersant added is 9.3% of the weight of the filter cake. In step S4, the coarse grinding speed is 2050 r / min, and the grinding time is 2.3 hours. The fine grinding speed is 3130 r / min, and the grinding time is 3.3 hours, with the temperature controlled at 27℃ throughout. In step S4, the vacuum drying temperature is 55.5℃, and the drying time is 8.8 hours. The sieving is performed using a 400-mesh filter screen.

[0046] Example 5

[0047] A production process for Disperse Orange 30 includes the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to 0℃, add 2,6-dichloro-4-nitroaniline to swell for 50 min, add 45% nitrosyl sulfuric acid solution in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.3. Diazo solution is added dropwise from bottom to top at 9°C, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 48℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 39%. The slurry is coarsely ground and finely ground at 28°C, filtered, vacuum dried and sieved to obtain Disperse Orange 30 finished product.

[0048] In step S1, the mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution is 1:4.9:1.4. The specific steps in step S1 are: adding 70% of the total mass of nitrosylsulfuric acid solution at 2°C for 1.2 hours; adding the remaining nitrosylsulfuric acid solution at 5°C for 0.6 hours; maintaining the temperature at 3°C ​​for 1.2 hours; and maintaining the temperature at 5°C for 1.6 hours. In step S2, the compound solvent is prepared by mixing deionized water, methanol, and ethanol at a mass ratio of 5.2:1.9:0.4. In step S2, the two-component buffer system is prepared by mixing acetic acid, ammonia, and deionized water at a mass ratio of 2.5:1:10; the mass percentage concentration of the ammonia is 26%.

[0049] In step S2, the mass ratio of N-acetoxyethyl-N-cyanoethyl aniline, the compound solvent, the acetic acid-ammonia water two-component buffer system, the rare earth catalyst, the amphoteric surfactant, and the diazonium solution is 100:750:23:0.5:0.7:252; the rare earth catalyst in step S2 is a compound of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:1.2; the amphoteric surfactant is a compound of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:1.2; the heat preservation reaction time in step S2 is 4 hours, and the temperature for ripening is 10°C for 2.5 hours.

[0050] In step S3, the mass ratio of the crude dye solution to the PEG2000 crystal form regulator is 4250:1; the temperature for microcrystalline reforming in step S3 is 48℃, and the holding time is 62 min; the isothermal stratification time is 122 min; the gradient water washing temperature in step S3 is successively 35℃, 40℃, and 45℃, with each washing and stirring lasting 22 min followed by 32 min of settling; the plate and frame filter press pressure is 0.4 MPa, and the time is 2.8 h; the compounding process in step S4... The powder is a compound of dispersant NF, sodium lignosulfonate, and dispersant SN-5040 in a mass ratio of 5:3:2.5; the amount of the compound dispersant added is 9.5% of the weight of the filter cake; the coarse grinding speed in step S4 is 2100 r / min and the grinding time is 2.5 h; the fine grinding speed is 3150 r / min and the grinding time is 3.5 h, with the temperature controlled at 28℃ throughout; the vacuum drying temperature in step S4 is 56℃ and the drying time is 9 h; the sieving is done using a 400 mesh filter screen.

[0051] Comparative Example 1 A production process for Disperse Orange 30 is basically the same as that in Example 5, except that an equal amount of rare earth catalyst is used instead of the amphoteric surfactant.

[0052] Comparative Example 2 A production process for Disperse Orange 30 is basically the same as that in Example 5, except that an equal amount of amphoteric surfactant is used instead of rare earth catalyst.

[0053] Comparative Example 3 A production process for Disperse Orange 30 is basically the same as that in Example 5, except that PEG2000 crystal form regulator is not added.

[0054] Comparative Example 4 A production process for Disperse Orange 30 is basically the same as that in Example 5, except that an equal amount of Pingpingjia O-25 is used instead of the amphoteric surfactant.

[0055] To further illustrate the beneficial technical effects of the production process of Disperse Orange 30 of the present invention, relevant performance tests were conducted on the Disperse Orange 30 involved in Example 5 and Comparative Examples 1-4. The test results are shown in Table 1, and the test methods are as follows: (1) Dye purity detection: A high-performance liquid chromatograph equipped with a C18 reversed-phase column (4.6 mm × 250 mm, 5 μm) was used with methanol-ultrapure water as the mobile phase. A dedicated gradient elution program was set: 0-10 min methanol volume fraction 70%, 10-20 min linearly increased to 90%, 20-28 min maintained at 90%, 28-30 min dropped back to 70% and the baseline was balanced; constant detection wavelength 430 nm, column temperature 30 ℃, flow rate 1.0 mL / min. Before the test, 0.05 g of Disperse Orange 30 sample dried to constant weight was accurately weighed, placed in a volumetric flask, and chromatographically pure methanol was added. The sample was ultrasonically vibrated for 15 min to fully dissolve the effective components. High-speed centrifugation was used to remove trace amounts of insoluble impurities. The supernatant was taken and diluted to volume to prepare the test solution. The chromatogram was collected on the instrument, and the relative percentage content of the main peak of the product was calculated using the area normalization method.

[0056] (2) Product synthesis yield test: Based on the theoretical yield of the limited amount of reactant monomer 2,6-dichloro-4-nitroaniline, the actual mass of the purified and dried finished dye was accurately weighed, and the pure product mass was calculated in combination with the measured purity of the product. The synthesis yield was calculated according to the percentage of the actual pure product mass to the theoretical product mass.

[0057] (3) Test of relative strength of original dye: The relative strength of the original slurry is tested in accordance with GB / T 27594-2025 standard. The higher the value, the stronger the dye’s coloring ability.

[0058] Table 1 Performance test results of Disperse Orange 30

[0059] As can be seen from Table 1, the Disperse Orange 30 produced by the production process disclosed in Example 5 has high purity, synthesis yield, and relative strength of the original dye. Comparative Example 1, which retains only the rare earth catalyst and lacks the amphoteric surfactant, and Comparative Example 2, which retains only the amphoteric surfactant and does not add the rare earth catalyst, and Comparative Example 4, which replaces the compound betaine amphoteric surfactant with Pingpingjia O-25, all showed varying degrees of decline in various indicators. Comparative Example 3, which omits the PEG2000 crystal form regulator, had the largest decrease in purity, yield, and color strength due to the disordered dye crystal form and the difficulty in removing impurities. This proves that there is a synergistic effect between the rare earth catalyst and the amphoteric betaine surfactant, and that the PEG2000 microcrystalline reforming purification step plays a key role in improving the overall quality of the product.

[0060] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A production process for Disperse Orange 30, characterized in that, Includes the following steps: Step S1, Segmented gradient salt-free diazotization: Pre-cool concentrated sulfuric acid with a mass percentage concentration of 98% to -2 to 0℃, add 2,6-dichloro-4-nitroaniline to swell for 40 to 50 min, add nitrite sulfuric acid solution with a mass percentage concentration of 40% to 45% in two segments and keep warm in each segment to obtain a stable diazo solution with a purity ≥99.5%; Step S2, Dynamic Buffer Controlled Coupling: N-acetyloxyethyl-N-cyanoethyl aniline is uniformly dispersed in a compound solvent, and an acetic acid-ammonia water two-component buffer system, rare earth catalyst and amphoteric surfactant are added to stabilize the pH at 4.1-4.

3. Diazo solution is added dropwise from bottom to top at 6-9℃, and the reaction is maintained at the temperature and then heated to mature, to obtain crude dye solution. Step S3, Micro-nano Crystal Modification and Purification: The crude dye solution is heated to 45-48℃, and PEG2000 crystal form regulator is added for micro-crystal reforming. After isothermal layering and impurity removal, it is washed with gradient warm water and plate and frame filter press to obtain high-purity dye filter cake. Step S4, Sand milling and refining: The filter cake, compound dispersant and deionized water are prepared into a slurry with a solid content of 36% to 39%. The slurry is coarsely ground and finely ground at 22 to 28°C, filtered, vacuum dried and sieved to obtain the Disperse Orange 30 finished product.

2. The production process of Disperse Orange 30 according to claim 1, characterized in that, The mass ratio of 2,6-dichloro-4-nitroaniline, 98% concentrated sulfuric acid, and nitrosylsulfuric acid solution in step S1 is 1:(4.6-4.9):(1.3-1.4).

3. The production process of Disperse Orange 30 according to claim 1, characterized in that, The segmentation in step S1 is as follows: add 60% to 70% of the total mass of nitrosyl sulfuric acid solution at -2 to 2℃ for 0.8 to 1.2 hours; add the remaining nitrosyl sulfuric acid solution at 3 to 5℃ for 0.4 to 0.6 hours; keep warm at 0 to 3℃ for 0.8 to 1.2 hours; keep warm at 3 to 5℃ for 1.4 to 1.6 hours.

4. The production process of Disperse Orange 30 according to claim 1, characterized in that, The compound solvent in step S2 is prepared by mixing deionized water, methanol, and ethanol in a mass ratio of (4.8-5.2):(1.7-1.9):0.4; the two-component buffer system in step S2 is prepared by mixing acetic acid, ammonia, and deionized water in a mass ratio of 2.5:1:10; and the mass percentage concentration of the ammonia is 24%-26%.

5. The production process of Disperse Orange 30 according to claim 1, characterized in that, The mass ratio of N-acetoxyethyl-N-cyanoethyl aniline, compound solvent, acetic acid-ammonia water two-component buffer system, rare earth catalyst, amphoteric surfactant and diazonium solution in step S2 is 100:(700~750):(21~23):(0.4~0.5):(0.5~0.7):

252.

6. The production process of Disperse Orange 30 according to claim 1, characterized in that, The rare earth catalyst in step S2 is a mixture of yttrium trifluoromethanesulfonate and lanthanum trifluoromethanesulfonate in a mass ratio of 3:(0.8-1.2); the amphoteric surfactant is a mixture of dodecyl dimethyl betaine and cocamidopropyl betaine in a mass ratio of 2:(0.8-1.2); the heat preservation reaction in step S2 lasts for 2-4 hours, and the temperature for ripening is 10°C for 1.5-2.5 hours.

7. The production process of Disperse Orange 30 according to claim 1, characterized in that, In step S3, the mass ratio of the crude dye solution to the PEG2000 crystal form regulator is (4200-4250):1; the temperature of the microcrystalline reforming in step S3 is 45-48℃, and the holding time is 58-62 min; the time for isothermal stratification is 118-122 min.

8. The production process of Disperse Orange 30 according to claim 1, characterized in that, In step S3, the gradient temperature water washing temperature is 35℃, 40℃, and 45℃ respectively, and the single washing and stirring time is 18-22 min, followed by standing for 28-32 min; the plate and frame filter press pressure is 0.35-0.4 MPa, and the time is 2.3-2.8 h.

9. The production process of Disperse Orange 30 according to claim 1, characterized in that, The compound dispersant mentioned in step S4 is a mixture of dispersant NF, sodium lignosulfonate and dispersant SN-5040 in a mass ratio of 5:(2-3):(1.5-2.5); the amount of the compound dispersant added is 8.5% to 9.5% of the weight of the filter cake.

10. The production process of Disperse Orange 30 according to claim 1, characterized in that, In step S4, the coarse grinding speed is 1900-2100 r / min and the grinding time is 1.5-2.5 h; the fine grinding speed is 3050-3150 r / min and the grinding time is 2.5-3.5 h, with the temperature controlled at 22-28℃ throughout the process; the vacuum drying temperature in step S4 is 54-56℃ and the drying time is 8-9 h; the sieving is done using a 400-mesh filter screen.

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