A preparation method of red disperse dye and red dye filter cake

Abstract

The present application provides a method for preparing a red disperse dye and a red dye filter cake, and relates to the technical field of dyes. The method for preparing a red disperse dye comprises five steps: preparing a thiazole mixed solution, preparing a diazo solution, preparing a dye precursor, synthesizing a dye, and preparing a dye slurry. The method has the advantages of simple process, low cost, and environmental friendliness.

Description

Technical Field

[0001] The invention relates to the technical field of dyes, and in particular to a preparation method of a red disperse dye and a red dye filter cake. Background Art

[0002] Traditional dye synthesis methods have the problems of complex process, high production cost and serious environmental pollution. In recent years, with the enhancement of environmental awareness and the advancement of synthesis technology, the development of new environmentally friendly, efficient and low-cost dye synthesis methods has become a research hotspot. The present invention aims to provide a novel method for preparing a bright red dye, which achieves low-cost and efficient preparation of the dye and reduces environmental pollution by optimizing reaction conditions and raw material ratios. Summary of the invention

[0003] The invention provides a method for preparing a red disperse dye. The method comprises five steps of preparing a thiazole mixed solution, preparing a diazo solution, preparing a dye precursor, synthesizing the dye and preparing a dye slurry. The method has the advantages of simple process, low cost and environmental friendliness.

[0004] In a first aspect, the present invention provides a method for preparing a red disperse dye, comprising:

[0005] Obtain concentrated sulfuric acid, add 2-amino-6-nitrobenzothiazole under stirring, heat to a predetermined temperature to dissolve, obtain a solution, dropwise add nitrosyl sulfuric acid to the solution, continue stirring until uniformly mixed, and form a thiazole mixed solution;

[0006] The temperature of sulfuric acid is lowered and maintained within a preset temperature range by using an external circulating refrigeration liquid, and a thiazole mixed solution is slowly added dropwise to the sulfuric acid, and after the addition is completed, low temperature stirring is maintained for a preset time to obtain a diazo liquid; an ice-water mixture is obtained, sulfuric acid and fatty alcohol polyoxyethylene ether are added after stirring evenly, and stirring is continued until completely dissolved, and N-ethyl-N-cyanoethyloxyethyl-m-toluidine is added to the solution, and slurrying is performed evenly to form a uniform slurry;

[0007] Slowly drop the diazo solution into the uniform slurry while stirring, continue stirring and reacting for a preset time after the dropwise addition is completed, heat to a preset temperature and continue stirring and reacting, filter the reaction liquid, and wash the filter cake with clean water to obtain a red dye filter cake;

[0008] The red dye filter cake is mixed with a dispersant in a preset ratio, and a sand mill disperser is used to perform sand milling dispersion to obtain a bright red dye slurry.

[0009] In some specific embodiments, the method comprises obtaining concentrated sulfuric acid, adding 2-amino-6-nitrobenzothiazole under stirring, heating to a predetermined temperature to dissolve, obtaining a solution, adding nitrosyl sulfuric acid dropwise to the solution, and continuing to stir until uniformly mixed to form a thiazole mixed solution, comprising:

[0010] According to the preset ratio, concentrated sulfuric acid and 2-amino-6-nitrobenzothiazole are added into the flask, and the stirring speed and time are controlled to completely dissolve the 2-amino-6-nitrobenzothiazole in the concentrated sulfuric acid to obtain a uniform solution;

[0011] Using a titration device, add nitrosyl sulfuric acid to the solution obtained in step 1 at a constant rate, and monitor the changes of parameters such as pH value and temperature of the solution in real time through a sensor, and dynamically adjust the dropping rate according to the monitoring data to ensure that the nitrosyl sulfuric acid is fully mixed with the solution;

[0012] After the addition is completed, the reaction solution is stirred continuously to determine whether the solution has reached a uniformly mixed state. If not, the stirring parameters are adjusted until the system determines that the mixture is uniform and a stable thiazole mixture is generated.

[0013] In some specific embodiments, the temperature of sulfuric acid is lowered and maintained within a preset temperature range by using an external circulating refrigeration liquid, a thiazole mixed solution is slowly added dropwise to the sulfuric acid, and after the addition is completed, low temperature stirring is maintained for a preset time to obtain a diazo liquid, comprising:

[0014] Obtain the component information of the thiazole mixed solution, calculate the amount of sulfuric acid required to prepare the diazo solution based on the preset stoichiometric ratio, and automatically prepare a 40% dilute sulfuric acid solution based on the calculation result;

[0015] The temperature of the dilute sulfuric acid solution is reduced to -10±3℃ by a refrigeration system, monitored in real time by a temperature sensor, and maintained within this temperature range by feedback control;

[0016] The thiazole mixture is slowly added dropwise to low-temperature dilute sulfuric acid. The dropping rate is accurately controlled by a flow meter. The temperature change of the solution is monitored at the same time. The dropping rate is dynamically adjusted according to the temperature fluctuation to ensure that the reaction is carried out under constant temperature conditions.

[0017] After the addition is completed, the temperature is maintained and the stirring reaction is continued for 2 hours. The completion of the diazotization reaction is determined by a chemical composition analysis instrument. If the reaction is incomplete, the stirring time is extended until the characteristic peak of the diazo liquid is detected, indicating that the diazotization is completed and the diazo liquid is obtained.

[0018] In some specific embodiments, the ice-water mixture is obtained, stirred evenly, sulfuric acid and fatty alcohol polyoxyethylene ether are added, and stirring is continued until completely dissolved, N-ethyl-N-cyanoethyloxyethyl-m-toluidine is added to the solution, and slurry is evenly beaten to form a uniform slurry, comprising:

[0019] The ice-water mixture is obtained, stirred evenly, sulfuric acid and fatty alcohol polyoxyethylene ether are added, and stirred until completely dissolved, specifically comprising:

[0020] Obtain an ice-water mixture, stir it to make it evenly distributed, and determine the amount of sulfuric acid and fatty alcohol polyoxyethylene ether added according to the volume of the ice-water mixture;

[0021] The calculated amount of sulfuric acid is gradually added to the ice-water mixture, and the sulfuric acid and ice-water are fully mixed by continuous stirring to obtain a uniform acidic solution;

[0022] The fatty alcohol polyoxyethylene ether is added to the acidic solution in batches, and the mixture is stirred thoroughly after each addition until the fatty alcohol polyoxyethylene ether is completely dissolved;

[0023] According to the dissolution of fatty alcohol polyoxyethylene ether, dynamically adjust the stirring time and speed to ensure that there are no undissolved solid particles in the system;

[0024] By testing the transparency of the solution, it is determined whether the fatty alcohol polyoxyethylene ether has been completely dissolved. If the solution is uniform and transparent, it indicates that it is completely dissolved.

[0025] Obtain the temperature data of the completely dissolved solution, and decide whether to cool the solution according to the temperature value;

[0026] If the solution temperature exceeds the set threshold, the cooling device is started to cool the solution until the temperature drops to within the target range;

[0027] The components of the cooled solution are analyzed, and the accuracy of the solution ratio is calculated by comparing the deviation between the theoretical ratio and the actual ratio;

[0028] If the ratio accuracy reaches the preset qualified standard, the solution is transferred to the next process for use, otherwise the solution formula is readjusted and the preparation is restarted;

[0029] According to adding N-ethyl-N-cyanoethyloxyethyl-m-toluidine into the solution, beating the solution evenly to form a uniform slurry, specifically comprising:

[0030] Obtain raw material data for N-ethyl-N-cyanoethyloxyethyl-m-toluidine, including chemical purity and physical state;

[0031] The parameters of the dissolving equipment are adjusted by a computer control system to ensure that N-ethyl-N-cyanoethyloxyethyl-m-toluidine can be completely dissolved in the solution;

[0032] A high-speed stirrer is used for stirring to ensure that N-ethyl-N-cyanoethyloxyethyl-m-toluidine is fully mixed with the solution;

[0033] Monitor the homogeneity of the slurry with an online turbidity sensor to ensure that there are no undissolved particles;

[0034] The viscosity of the slurry is measured by a rheometer, and the stirring speed and time are adjusted to achieve the ideal slurry state;

[0035] An automatic sampling system is used to collect slurry samples, and a spectrometer is used to determine whether the chemical composition of the slurry meets the preset standards;

[0036] According to the results of the spectral analysis, the amount of N-ethyl-N-cyanoethyloxyethyl-m-toluidine added was adjusted to optimize the chemical properties of the slurry;

[0037] Pass the adjusted slurry through a filtration system to remove possible impurities;

[0038] The filtered slurry is transferred to the next production stage for the synthesis of dyes or other related processes.

[0039] In some specific embodiments, the step of slowly dropping the diazo solution into the uniform slurry and stirring the mixture is continued, stirring the mixture for a preset time after the dropping is completed, heating the mixture to a preset temperature and stirring the mixture, filtering the reaction solution, and washing the filter cake with clean water to obtain a red dye filter cake comprises:

[0040] According to the preset reaction conditions, the reaction solution is filtered to obtain a filter cake containing red dye;

[0041] The filter cake is washed multiple times with clean water to remove residual impurities and obtain a red dye filter cake with higher purity;

[0042] By testing the chromaticity and color index of the red dye filter cake, it is determined whether it meets the preset quality standards.

[0043] In some specific embodiments, the red dye filter cake is mixed with a dispersant in a preset ratio, and a sand mill disperser is used to perform sand milling and dispersion to obtain a bright red dye slurry, comprising:

[0044] According to a preset ratio, the red dye filter cake is mixed with a dispersant to obtain a mixture;

[0045] Add the mixture into a sand mill disperser and set the speed and time parameters of the sand mill disperser;

[0046] Starting a sand mill disperser to perform sand mill dispersion treatment on the mixture to obtain a dispersed dye slurry;

[0047] Check the particle size distribution of the dye slurry. If the particle size distribution does not meet the requirements, adjust the sand mill disperser parameters and re-sand mill dispersion.

[0048] The dye slurry meeting the particle size distribution requirements is homogenized to obtain a homogenized dye slurry.

[0049] In a second aspect, the present application provides a red dye filter cake prepared according to the above-mentioned method for preparing red disperse dye.

[0050] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0051] The object of the present invention is to provide a method for preparing a red disperse dye and a red dye filter cake, which comprises five steps of preparing a thiazole mixed solution, preparing a diazo solution, preparing a dye precursor, synthesizing a dye, and preparing a dye slurry. The method has the advantages of simple process, low cost, and environmental friendliness. Compared with the traditional process, the method for preparing a red disperse dye has the following technical advantages:

[0052] 1. Simplified process and reduced cost: This solution simplifies the complex process of traditional dye synthesis by optimizing the reaction steps and raw material ratio, reduces unnecessary operation steps and raw material waste, and thus reduces production costs. This makes the preparation of the bright red dye more economical and efficient.

[0053] 2. Excellent environmental performance: This solution uses environmentally friendly raw materials and solvents, such as concentrated sulfuric acid, nitrosyl sulfuric acid, etc., and reduces the emission of harmful substances and environmental pollution under strict control of reaction conditions and waste treatment. At the same time, the dye itself has good environmental performance and meets the requirements of modern industry for green chemical products.

[0054] 3. Stable product quality and excellent performance: By precisely controlling the reaction conditions and raw material quality, this solution can produce bright red dyes with bright colors, good fastness and excellent dispersibility. This dye has good permeability and uniformity during the dyeing process, and can give textiles bright colors and lasting color fastness.

[0055] 4. High flexibility and adaptability: Some steps and raw material ratios in this scheme can be adjusted and optimized according to actual needs to adapt to different types of fibers and dyeing processes. This flexibility makes the bright red dye have a wide range of application prospects in the textile industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 The present invention is a flow chart of a method for preparing a red disperse dye. DETAILED DESCRIPTION

[0057] The following will describe the technical solutions in the embodiments of the present invention in detail in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention.

[0058] like Figure 1 The preparation method of a red disperse dye in this embodiment may specifically include:

[0059] S101, obtaining concentrated sulfuric acid, adding 2-amino-6-nitrobenzthiazole under stirring, heating to a predetermined temperature to dissolve, obtaining a solution, dropping nitrosyl sulfuric acid into the solution, continuing to stir until uniformly mixed, to form a thiazole mixed solution.

[0060] Example: Add 98% concentrated sulfuric acid to a dry 100mL flask, add 19.6g of 2-amino-6-nitrobenzthiazole while stirring, and heat to 50℃ to dissolve; add 32g of 40% nitrosyl sulfuric acid dropwise to the above solution, continue stirring until evenly mixed, and form a thiazole mixture.

[0061] Here, concentrated sulfuric acid is obtained, 2-amino-6-nitrobenzthiazole is added under stirring, and the temperature is raised to 50°C to dissolve to obtain a thiazole solution. According to the volume of the thiazole solution, the amount of nitrosyl sulfuric acid to be added is calculated, and nitrosyl sulfuric acid is slowly added dropwise, and stirring is continued until uniformly mixed to form a thiazole mixed solution.

[0062] Specifically, concentrated sulfuric acid and 2-amino-6-nitrobenzothiazole are added into a flask according to a preset ratio, and the stirring speed and time are controlled to completely dissolve 2-amino-6-nitrobenzothiazole in the concentrated sulfuric acid to obtain a uniform solution.

[0063] Using a titration device, add nitrosyl sulfuric acid to the solution obtained in step 1 at a constant rate, and monitor the changes in parameters such as the pH value and temperature of the solution in real time through a sensor, and dynamically adjust the dropping rate according to the monitoring data to ensure that the nitrosyl sulfuric acid is fully mixed with the solution.

[0064] After the addition is completed, the reaction solution is stirred continuously to determine whether the solution has reached a uniformly mixed state. If not, the stirring parameters are adjusted until the system determines that the mixture is uniform and a stable thiazole mixture is generated.

[0065] S102, using an external circulating refrigeration liquid to lower the temperature of sulfuric acid and maintain it within a preset temperature range, slowly dropping the thiazole mixed solution into the sulfuric acid, and maintaining low temperature stirring for a preset time after the dropping is completed to obtain a diazo liquid.

[0066] Example: Add 120g of 40% sulfuric acid into a 250mL flask, use an external circulating refrigeration fluid to lower the temperature of the dilute acid to -10±3℃, maintain the low temperature and slowly add the thiazole mixture dropwise, and maintain it for 2 hours for use.

[0067] Here, the component information of the thiazole mixed solution is obtained, and the amount of sulfuric acid required for preparing the diazo solution is calculated in combination with the preset stoichiometric ratio, and a 40% dilute sulfuric acid solution is automatically prepared based on the calculation result.

[0068] The temperature of the dilute sulfuric acid solution is reduced to -10±3°C by a refrigeration system, monitored in real time by a temperature sensor, and maintained within this temperature range by feedback control.

[0069] The thiazole mixture is slowly dripped into the low-temperature dilute sulfuric acid, and the dripping rate is accurately controlled by the flow meter. At the same time, the temperature change of the solution is monitored, and the dripping rate is dynamically adjusted according to the temperature fluctuation to ensure that the reaction is carried out under constant temperature conditions. Here, by detecting the temperature of sulfuric acid, it is determined whether the temperature of sulfuric acid is maintained within the preset temperature range. If the temperature of sulfuric acid is higher than the preset temperature range, the sulfuric acid is continuously cooled using an external circulating refrigerant; according to the preset dripping rate, the speed of dripping the thiazole mixture into the sulfuric acid is controlled to ensure a smooth dripping process; a temperature sensor is used to monitor the temperature change of sulfuric acid in real time, and the temperature data is transmitted to the control system; by analyzing the temperature data, the refrigeration power of the external circulating refrigerant is dynamically adjusted to maintain the temperature of sulfuric acid stable within the preset temperature range.

[0070] After the addition is completed, the temperature is maintained and the stirring reaction is continued for 2 hours. The completion of the diazotization reaction is determined by a chemical composition analysis instrument. If the reaction is incomplete, the stirring time is extended until the characteristic peak of the diazo liquid is detected, indicating that the diazotization is completed and the diazo liquid is obtained.

[0071] Specifically, first, according to the preset ratio, add 98% concentrated sulfuric acid and 2-amino-6-nitrobenzothiazole into the flask, control the stirring speed to 100 rpm, stir for 30 minutes, and completely dissolve 2-amino-6-nitrobenzothiazole to obtain a uniform solution. Then, add nitrosyl sulfuric acid at a constant rate of 5 ml / min, monitor the pH value and temperature of the solution in real time, and dynamically adjust the dropping rate. After the addition is completed, increase the stirring speed to 300 rpm.

[0072] S103, obtaining an ice-water mixture, stirring it evenly, adding sulfuric acid and fatty alcohol polyoxyethylene ether, continuing to stir until completely dissolved, adding N-ethyl-N-cyanoethyloxyethyl-m-toluidine to the solution, beating evenly to form a uniform slurry.

[0073] Example: Add 500g of ice-water mixture into a 1000mL flask, stir evenly, add 8g of 98% sulfuric acid, then add 0.2g of fatty alcohol polyoxyethylene ether, continue stirring until completely dissolved, add 23.5g of coupling component N-ethyl-N-cyanoethyloxyethyl-m-toluidine, beat evenly to form a uniform slurry.

[0074] Here, an ice-water mixture is obtained, and the mixture is evenly distributed by stirring, and the amount of sulfuric acid and fatty alcohol polyoxyethylene ether added is determined according to the volume of the ice-water mixture; the calculated amount of sulfuric acid is gradually added to the ice-water mixture, and the sulfuric acid and ice water are fully mixed by continuous stirring to obtain a uniform acidic solution; the fatty alcohol polyoxyethylene ether is added to the acidic solution in batches, and is fully stirred after each addition until the fatty alcohol polyoxyethylene ether is completely dissolved; the stirring time and speed are dynamically adjusted according to the dissolution of the fatty alcohol polyoxyethylene ether to ensure that there are no undissolved solid particles in the system; the transparency of the solution is tested to determine Check whether the fatty alcohol polyoxyethylene ether has been completely dissolved. If the solution is uniform and transparent, it indicates that it is completely dissolved; obtain the temperature data of the completely dissolved solution, and decide whether the solution needs to be cooled according to the temperature value; if the solution temperature exceeds the set threshold, start the cooling device to cool the solution until the temperature drops to the target range; analyze the components of the cooled solution, and calculate the solution ratio accuracy by comparing the deviation between the theoretical ratio and the actual ratio; if the ratio accuracy reaches the preset qualified standard, transfer the solution to the next process for use, otherwise readjust the solution formula and return to start preparation again.

[0075] Specifically, first, prepare a certain volume of ice-water mixture, and stir it to make its temperature and concentration uniform. According to the volume of ice water, the mass of sulfuric acid and fatty alcohol polyoxyethylene ether to be added is calculated by the stoichiometric ratio method. For example, if the volume of ice water is 1000mL, according to the volume ratio of 10:1, the amount of sulfuric acid added is 100mL. The calculated sulfuric acid is gradually added to the ice water at a rate of 10mL / min through a peristaltic pump, and stirred continuously at a speed of 300rpm for 5 minutes to fully mix the sulfuric acid and ice water. Then, the fatty alcohol polyoxyethylene ether is added to the acidic solution in 3 batches, and the amount of each batch is 1 / 3 of the total amount. After adding, stir at a speed of 500rpm for 10 minutes, and detect the transparency of the solution by visual observation and transparency detector. When the transparency reaches more than 99%, it is determined that the fatty alcohol polyoxyethylene ether has been completely dissolved. During the dissolution process, the solution temperature is monitored in real time. If the temperature exceeds 40°C, it is cooled by a cooling device, and the cooling intensity is dynamically adjusted according to the cooling curve to control the temperature to about 25°C. The solution was analyzed by high performance liquid chromatography, and the actual content of each component was calculated by peak area normalization method, and compared with the theoretical ratio. When the deviation was less than 1%, the accuracy of the ratio was determined to be up to standard. Finally, the solution was transferred to a sealed container for the next process.

[0076] According to the technical goal of adding N-ethyl-N-cyanoethyloxyethyl-m-toluidine to the solution, beating the solution evenly, and forming a uniform slurry, the following steps are performed: Step 1: Obtain the raw material data of N-ethyl-N-cyanoethyloxyethyl-m-toluidine, including chemical purity and physical state. Step 2: Adjust the parameters of the dissolution equipment through the computer control system to ensure that N-ethyl-N-cyanoethyloxyethyl-m-toluidine can be completely dissolved in the solution. Step 3: Stir with a high-speed stirrer to ensure that N-ethyl-N-cyanoethyloxyethyl-m-toluidine is fully mixed with the solution. Step 4: Monitor the uniformity of the slurry through an online turbidity sensor to ensure that there are no undissolved particles. Step 5: Determine the viscosity of the slurry through a rheometer, and adjust the stirring speed and time to achieve an ideal slurry state. Step 6: Collect slurry samples through an automatic sampling system, and determine whether the chemical composition of the slurry meets the preset standard through a spectrometer. Step 7: According to the results of the spectral analysis, adjust the amount of N-ethyl-N-cyanoethyloxyethyl-m-toluidine to optimize the chemical properties of the slurry. Step 8: The adjusted slurry is passed through a filtration system to remove possible impurities. Step 9: The filtered slurry is transferred to the next production stage for dye synthesis or other related processes.

[0077] Specifically, in the process of preparing a uniform slurry of N-ethyl-N-cyanoethyloxyethyl-m-toluidine, it is first necessary to obtain the raw material data of the compound, including the chemical purity is usually set to more than 98%, and the physical state is a solid powder. Using a computer control system, the temperature of the dissolution equipment is adjusted to 30°C according to the solubility parameter of the compound (such as a solubility of 50g / L at 25°C) to improve the dissolution efficiency. Subsequently, a high-speed stirrer is used to stir at a speed of 1500 rpm for 30 minutes to ensure that the compound and the solvent are fully mixed to form a uniform solution. The turbidity of the slurry is monitored in real time by an online turbidity sensor, and the turbidity value should be controlled below 5NTU to confirm that there are no undissolved particles in the solution. Next, the viscosity of the slurry is measured using a rheometer. If the initial viscosity is 1200mPa·s, the viscosity is reduced to 800mPa·s by adjusting the stirring speed to 1800 rpm and extending the stirring time to 45 minutes to achieve an ideal state. An automatic sampling system is used to collect slurry samples, and the chemical composition of the samples is analyzed by a spectrometer to ensure that the proportions of all components meet the preset standards, such as the concentration of N-ethyl-N-cyanoethyloxyethyl-m-toluidine is maintained at 5% w / v. According to the results of the spectral analysis, if the actual concentration is found to be 45% w / v, the addition amount is adjusted to 55% w / v to compensate for the difference. Finally, the adjusted slurry is passed through a filtration system with a filter pore size set to 10 microns to remove any potential impurities and ensure the purity of the slurry. The filtered slurry can be transferred to the next production stage for the synthesis process of advanced dyes.

[0078] S104, slowly drop the diazo liquid into the uniform slurry while keeping stirring, continue stirring and reacting for a preset time after the dropwise addition is completed, heat to a preset temperature and continue stirring and reacting, filter the reaction liquid, and wash the filter cake with clean water to obtain a red dye filter cake.

[0079] Here, the chemical formula of the red dye filter cake is:

[0080]

[0081] R=H、COCH 3 , C 2 H 4 CN.

[0082] Example: Slowly add diazo solution, keep stirring during the addition, continue stirring and react for 2 hours after the addition is completed, then raise the temperature to 70°C, continue stirring and react for a period of time until the reaction is complete, filter the reaction liquid, wash the filter cake with clean water, and obtain a red dye filter cake.

[0083] Here, according to the preset reaction conditions, the reaction solution is filtered to obtain a filter cake containing red dye.

[0084] The filter cake is washed multiple times with clean water to remove residual impurities and obtain a red dye filter cake with higher purity.

[0085] By testing the chromaticity, color and other indicators of the red dye filter cake, it is determined whether it meets the preset quality standards.

[0086] Specifically, according to the preset reaction conditions, the reaction solution is vacuum filtered, and the filtrate is filtered using a polypropylene membrane with a pore size of 45 μm to obtain a filter cake containing red dye. The filter cake is washed three times with deionized water, and the volume of each washing liquid is 5 times the mass of the filter cake to remove residual impurities such as inorganic salts, and after drying, a red dye filter cake with a purity of 98% is obtained. The absorbance of the filter cake at the maximum absorption wavelength of 520 nm is tested by a spectrophotometer, and the chromaticity value is calculated according to the Lambert-Beer law. The result shows that the chromaticity reaches 120, which meets the preset quality standards.

[0087] S105, mixing the red dye filter cake and the dispersant according to a preset ratio, and performing sand milling and dispersion using a sand mill disperser to obtain a bright red dye slurry.

[0088] Example: The obtained red dye filter cake is mixed with dispersant MF in a ratio of 1:1.

[0089] Specifically:

[0090] According to a preset ratio (1:1), the red dye filter cake is mixed with a dispersant to obtain a mixture;

[0091] Add the mixture into a sand mill disperser and set the speed and time parameters of the sand mill disperser;

[0092] Starting a sand mill disperser to perform sand mill dispersion treatment on the mixture to obtain a dispersed dye slurry;

[0093] Check the particle size distribution of the dye slurry. If the particle size distribution does not meet the requirements, adjust the sand mill disperser parameters and re-sand mill dispersion.

[0094] The dye slurry meeting the particle size distribution requirements is homogenized to obtain a homogenized dye slurry.

[0095] Specifically, first, the red dye filter cake is mixed with a dispersant, and mixed at a speed of 3000 rpm for 10 minutes by a high-speed mixer to obtain a uniform mixture. Then, the mixture is added to a sand mill disperser, and the speed of the sand mill disperser is set to 1500 rpm, and the dispersion time is 60 minutes. The sand mill disperser is started to perform sand milling and dispersion treatment on the mixture, and the particle size distribution of the dispersed dye slurry is detected by a laser particle size analyzer. If the average particle size is greater than 500 nanometers, the sand mill speed is increased by 200 rpm, and the dispersion time is extended by 10 minutes until the particle size distribution meets the requirement of D90≤500nm. The dye slurry with qualified particle size is subjected to 3 cycles of homogenization treatment using a tubular homogenizer at a pressure of 50MPa.

[0096] The present application provides a red dye filter cake prepared according to the above-mentioned method for preparing red disperse dye.

[0097] The present invention provides a method for preparing a red disperse dye and a red dye filter cake, which comprises five steps of preparing a thiazole mixed solution, preparing a diazo solution, preparing a dye precursor, synthesizing a dye, and preparing a dye slurry. The method has the advantages of simple process, low cost, and environmental friendliness. Compared with the traditional process, the method for preparing a red disperse dye has the following technical advantages:

[0098] 1. Simplified process and reduced cost: This solution simplifies the complex process of traditional dye synthesis by optimizing the reaction steps and raw material ratio, reduces unnecessary operation steps and raw material waste, and thus reduces production costs. This makes the preparation of the bright red dye more economical and efficient.

[0099] 2. Excellent environmental performance: This solution uses environmentally friendly raw materials and solvents, such as concentrated sulfuric acid, nitrosyl sulfuric acid, etc., and reduces the emission of harmful substances and environmental pollution under strict control of reaction conditions and waste treatment. At the same time, the dye itself has good environmental performance and meets the requirements of modern industry for green chemical products.

[0100] 3. Stable product quality and excellent performance: By precisely controlling the reaction conditions and raw material quality, this solution can produce bright red dyes with bright colors, good fastness and excellent dispersibility. This dye has good permeability and uniformity during the dyeing process, and can give textiles bright colors and lasting color fastness.

[0101] 4. High flexibility and adaptability: Some steps and raw material ratios in this scheme can be adjusted and optimized according to actual needs to adapt to different types of fibers and dyeing processes. This flexibility makes the bright red dye have a wide range of application prospects in the textile industry.

[0102] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the present application. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) to form a technical solution.

Claims

1. A method for preparing a red disperse dye, characterized in that: The method comprises: Obtain concentrated sulfuric acid, add 2-amino-6-nitrobenzothiazole under stirring, heat to a predetermined temperature to dissolve, obtain a solution, dropwise add nitrosyl sulfuric acid to the solution, continue stirring until uniformly mixed, and form a thiazole mixed solution; The temperature of sulfuric acid is lowered and maintained within a preset temperature range by using an external circulating refrigeration liquid, and a thiazole mixed solution is slowly added dropwise to the sulfuric acid, and after the addition is completed, low temperature stirring is maintained for a preset time to obtain a diazo liquid; an ice-water mixture is obtained, sulfuric acid and fatty alcohol polyoxyethylene ether are added after stirring evenly, and stirring is continued until completely dissolved, and N-ethyl-N-cyanoethyloxyethyl-m-toluidine is added to the solution, and slurrying is performed evenly to form a uniform slurry; Slowly drop the diazo solution into the uniform slurry while stirring, continue stirring and reacting for a preset time after the dropwise addition is completed, heat to a preset temperature and continue stirring and reacting, filter the reaction liquid, and wash the filter cake with clean water to obtain a red dye filter cake; The red dye filter cake is mixed with a dispersant in a preset ratio, and a sand mill disperser is used to perform sand milling dispersion to obtain a bright red dye slurry.

2. The method for preparing red disperse dyes according to claim 1, wherein The method comprises obtaining concentrated sulfuric acid, adding 2-amino-6-nitrobenzothiazole under stirring, heating to a predetermined temperature to dissolve, obtaining a solution, dropping nitrosyl sulfuric acid into the solution, and continuing to stir until uniformly mixed to form a thiazole mixed solution, comprising: According to the preset ratio, concentrated sulfuric acid and 2-amino-6-nitrobenzothiazole are added into the flask, and the stirring speed and time are controlled to completely dissolve the 2-amino-6-nitrobenzothiazole in the concentrated sulfuric acid to obtain a uniform solution; Using a titration device, add nitrosyl sulfuric acid to the solution obtained in step 1 at a constant rate, and monitor the changes of parameters such as pH value and temperature of the solution in real time through a sensor, and dynamically adjust the dropping rate according to the monitoring data to ensure that the nitrosyl sulfuric acid is fully mixed with the solution; After the addition is completed, the reaction solution is stirred continuously to determine whether the solution has reached a uniformly mixed state. If not, the stirring parameters are adjusted until the system determines that the mixture is uniform and a stable thiazole mixture is generated.

3. The method for preparing red disperse dyes according to claim 1, wherein The method comprises: using an external circulating refrigeration liquid to lower the temperature of sulfuric acid and maintain it within a preset temperature range, slowly dropping a thiazole mixed solution into the sulfuric acid, and maintaining low temperature stirring for a preset time after the dropwise addition is completed to obtain a diazo liquid, comprising: Obtain the component information of the thiazole mixed solution, calculate the amount of sulfuric acid required to prepare the diazo solution based on the preset stoichiometric ratio, and automatically prepare a 40% dilute sulfuric acid solution based on the calculation result; The temperature of the dilute sulfuric acid solution is reduced to -10±3℃ by a refrigeration system, monitored in real time by a temperature sensor, and maintained within this temperature range by feedback control; The thiazole mixture is slowly added dropwise to low-temperature dilute sulfuric acid. The dropping rate is accurately controlled by a flow meter. The temperature change of the solution is monitored at the same time. The dropping rate is dynamically adjusted according to the temperature fluctuation to ensure that the reaction is carried out under constant temperature conditions. After the addition is completed, the temperature is maintained and the stirring reaction is continued for 2 hours. The completion of the diazotization reaction is determined by a chemical composition analysis instrument. If the reaction is incomplete, the stirring time is extended until the characteristic peak of the diazo liquid is detected, indicating that the diazotization is completed and the diazo liquid is obtained.

4. The method for preparing red disperse dye according to claim 1, wherein The ice-water mixture is obtained, stirred evenly, sulfuric acid and fatty alcohol polyoxyethylene ether are added, and stirring is continued until completely dissolved, N-ethyl-N-cyanoethyloxyethyl-m-toluidine is added to the solution, and slurry is evenly beaten to form a uniform slurry, including: The ice-water mixture is obtained, stirred evenly, sulfuric acid and fatty alcohol polyoxyethylene ether are added, and stirred until completely dissolved, specifically comprising: Obtain an ice-water mixture, stir it to make it evenly distributed, and determine the amount of sulfuric acid and fatty alcohol polyoxyethylene ether added according to the volume of the ice-water mixture; The calculated amount of sulfuric acid is gradually added to the ice-water mixture, and the sulfuric acid and ice-water are fully mixed by continuous stirring to obtain a uniform acidic solution; The fatty alcohol polyoxyethylene ether is added to the acidic solution in batches, and the mixture is stirred thoroughly after each addition until the fatty alcohol polyoxyethylene ether is completely dissolved; According to the dissolution of fatty alcohol polyoxyethylene ether, dynamically adjust the stirring time and speed to ensure that there are no undissolved solid particles in the system; By testing the transparency of the solution, it is determined whether the fatty alcohol polyoxyethylene ether has been completely dissolved. If the solution is uniform and transparent, it indicates that it is completely dissolved. Obtain the temperature data of the completely dissolved solution, and decide whether to cool the solution according to the temperature value; If the solution temperature exceeds the set threshold, the cooling device is started to cool the solution until the temperature drops to within the target range; The components of the cooled solution are analyzed, and the accuracy of the solution ratio is calculated by comparing the deviation between the theoretical ratio and the actual ratio; If the ratio accuracy reaches the preset qualified standard, the solution is transferred to the next process for use, otherwise the solution formula is readjusted and the preparation is restarted; According to adding N-ethyl-N-cyanoethyloxyethyl-m-toluidine into the solution, beating the solution evenly to form a uniform slurry, specifically comprising: Obtain raw material data for N-ethyl-N-cyanoethyloxyethyl-m-toluidine, including chemical purity and physical state; The parameters of the dissolving equipment are adjusted by a computer control system to ensure that N-ethyl-N-cyanoethyloxyethyl-m-toluidine can be completely dissolved in the solution; A high-speed stirrer is used for stirring to ensure that N-ethyl-N-cyanoethyloxyethyl-m-toluidine is fully mixed with the solution; Monitor the homogeneity of the slurry with an online turbidity sensor to ensure that there are no undissolved particles; The viscosity of the slurry is measured by a rheometer, and the stirring speed and time are adjusted to achieve the ideal slurry state; An automatic sampling system is used to collect slurry samples, and a spectrometer is used to determine whether the chemical composition of the slurry meets the preset standards; According to the results of the spectral analysis, the amount of N-ethyl-N-cyanoethyloxyethyl-m-toluidine added was adjusted to optimize the chemical properties of the slurry; Pass the adjusted slurry through a filtration system to remove possible impurities; The filtered slurry is transferred to the next production stage for the synthesis of dyes or other related processes.

5. The method for preparing red disperse dye according to claim 1, wherein The step of slowly dropping the diazo solution into the uniform slurry and stirring the mixture is continued. After the dropping is completed, the mixture is stirred for a preset time, the temperature is raised to a preset temperature, the mixture is stirred for a preset time, the reaction liquid is filtered, and the filter cake is washed with clean water to obtain a red dye filter cake, including: According to the preset reaction conditions, the reaction solution is filtered to obtain a filter cake containing red dye; The filter cake is washed multiple times with clean water to remove residual impurities and obtain a red dye filter cake with higher purity; By testing the chromaticity and color index of the red dye filter cake, it is determined whether it meets the preset quality standards.

6. The method for preparing red disperse dye according to claim 1, wherein The red dye filter cake is mixed with a dispersant in a preset ratio, and a sand mill disperser is used to perform sand milling and dispersion to obtain a bright red dye slurry, comprising: According to a preset ratio, the red dye filter cake is mixed with a dispersant to obtain a mixture; Add the mixture into a sand mill disperser and set the speed and time parameters of the sand mill disperser; Starting a sand mill disperser to perform sand mill dispersion treatment on the mixture to obtain a dispersed dye slurry; Check the particle size distribution of the dye slurry. If the particle size distribution does not meet the requirements, adjust the sand mill disperser parameters and re-sand mill dispersion. The dye slurry meeting the particle size distribution requirements is homogenized to obtain a homogenized dye slurry.

7. A red dye filter cake prepared according to the method for preparing a red disperse dye according to any one of claims 1 to 6.

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