Process for producing solvent blue 104 by solvent method

Abstract

The invention belongs to the technical field of chemical dye production, and particularly discloses a process for producing solvent blue 104 by a solvent method, which comprises the following steps: adding N-methyl pyrrolidone as a solvent into a condensation reaction kettle, sequentially adding p-tritoluidine, 1, 4-dihydroxy anthraquinone, a 1, 4-dihydroxy anthraquinone leuco body, boric acid and salicylic acid, closing the kettle, heating, keeping the temperature, and cooling to room temperature to obtain the solvent blue 104. And transferring to an oxidation kettle after a side end point, adding potassium hydroxide in batches, introducing air for reaction, cooling, filtering, washing and drying to obtain a finished product, collecting, filtering and washing liquid, and recovering the N-methyl pyrrolidone solvent for reuse. According to the method, N-methyl pyrrolidone used in the production process of the solvent blue 104 is recycled, so that waste of production resources is avoided, pollutants generated by a solvent in wastewater are reduced, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical dye production, and specifically relates to a process for producing solvent blue 104 by a solvent method. BACKGROUND

[0002] Solvent blue 104, also known as transparent blue 2B, has a CAS number of 116-75-6, is a blue powder, has bright and pure color, has good light resistance and heat resistance, can remain stable at a temperature as high as 300 DEG C, has excellent coloring capacity, and is suitable for coloring various plastics, such as PS, SAN, ABS, PC, PET, PBT, PVC-R and PMMA, and is particularly suitable for plastic products that need high-temperature processing, such as injection-molded parts and extruded parts. Solvent blue 104 is also suitable for dyeing synthetic fibers such as polyester fibers and nylon fibers, and can provide uniform blue color. Solvent blue 104 can also be used for coloring in the paint, ink and coating industries, and for dyeing materials such as resins and rubbers. In outdoor environments, solvent blue 104 can resist the effects of ultraviolet light, rain and other harsh conditions, and maintain color stability.

[0003] Currently, the mainstream industrialized preparation method of solvent blue 104 usually uses 1,4-dihydroxyanthraquinone and mesitylamine to prepare by condensation reaction. In order to avoid a too viscous reaction system and promote the reaction, it is often necessary to add an excess of mesitylamine, which is one of the reactants. The excess mesitylamine is used as a reactant and a solvent for the reaction system during this process. Through retrieval, a patent (application number CN201710029347.2) discloses a technical solution for recycling the production mother liquor containing excess mesitylamine, which serves the purpose of environmentally friendly production. However, the following problems in the industry have not been solved: the excess reactant makes the separation and purification process of the product complicated, a large amount of methanol is needed for multiple times of bubble washing and refining during the purification process, which increases the cost of purification; and the excess mesitylamine may cause amine residues in the product, affecting the color, and affecting the purity of the product.

[0004] With the improvement of environmental awareness, the requirement for environmental protection in chemical production is also getting higher and higher. Therefore, it is of great practical significance to develop an environmentally friendly and high resource utilization rate production method of solvent blue 104. SUMMARY

[0005] The purpose of the present application is to provide a process for synthesizing solvent blue 104 by a solvent method, which reduces the amount of mesitylamine added as a reactant and adds a recyclable environmentally friendly solvent, instead of the traditional solvent method that relies on excess mesitylamine as a reaction medium.

[0006] The technical solution of the present application is a process for producing solvent blue 104 by a solvent method, which comprises the following steps:

[0007] (a) Add N-methyl pyrrolidone (NMP) as a solvent into a condensation reactor, and sequentially add p-mesitylamine, 1,4-dihydroxyanthraquinone, 1,4-dihydroxyanthraquinone leuco, boric acid, and salicylic acid. After the feeding is completed, close the reactor and heat it up. After 1.5-2 hours, heat it up to 120-122℃, and keep it at this temperature for 3 hours. Then, heat it up to 140-142℃, and keep it at this temperature for 12 hours. After the holding time is over, take a sample for end point detection;

[0008] wherein the mass ratio of 1,4-dihydroxyanthraquinone to NMP is 1:(3-4), the mass ratio of 1,4-dihydroxyanthraquinone to p-mesitylamine, 1,4-dihydroxyanthraquinone leuco is 1:(0.9-1):(0.3-0.4), and the mass ratio of 1,4-dihydroxyanthraquinone to boric acid, salicylic acid is 1:(0.08-0.1):(0.01-0.02);

[0009] (b) Preheat the oxidation reactor to 50-55℃, and slowly transfer the material in the condensation reactor of step (a) into the oxidation reactor after pressurizing it with nitrogen. After confirming that the material in the condensation reactor is completely transferred, use nitrogen to blow clean the residual material in the transfer pipeline to avoid pipeline blockage;

[0010] (c) After the transfer is completed, keep the stirring and temperature control of the oxidation reactor at 70-80℃. During this period, add potassium hydroxide in portions, control the reactor temperature not to exceed 90℃, and keep the stirring uniform for about 40 minutes. After the temperature is stabilized at 85-90℃, open the bottom valve to pass air for oxidation for 9 hours, during which the temperature is controlled at 85-90℃, and the air flow rate is controlled at 10-12m³ / h;

[0011] (d) After the oxidation time is over, close the bottom valve to stop the air passing, stir for 1 hour, and then discharge the material after cooling to 45-50℃. Dry the mother liquor and collect it into a mother liquor recovery reactor. Wash the material with 60-70℃ warm water in portions, collect the washing water into the mother liquor recovery reactor, and transfer the mother liquor and the washing water into the reactor column of a column distillation tower to recover NMP by distillation;

[0012] (e) Wash the filter cake with 85℃ hot water until it is neutral and the water is clear, dry it, and obtain the dry product of solvent blue 104.

[0013] Further, the end point analysis method in step (a) is thin layer chromatography (TLC) method. The developing agent is a mixture of toluene and acetone, and the solvent is chloroform. The end point is controlled to be no spot or a small amount of purple spot.

[0014] Further, from the second batch, the NMP used in step (a) is preferably the NMP recovered in step (f).

[0015] Further, in step (c), the total mass ratio of potassium hydroxide to 1,4-dihydroxyanthraquinone is (0.55-0.6):1.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] 1. After adding NMP as a solvent to the reaction system, the reactant ratio can be more accurately controlled, the excess of mesitylamine can be avoided, the energy consumption and operation complexity during the subsequent product separation and purification can be reduced, the raw material consumption can be significantly reduced, and the production cost can be reduced.

[0018] 2. By recycling the solvent NMP, the solvent NMP can be reused multiple times, the emission of organic solvents to the environment can be greatly reduced from the source, the wastewater treatment load and cost can be reduced, and the pollution to the environment can be reduced.

[0019] 3. By using specific raw material input ratio, and using specific reaction system temperature and air flow rate, the generation of by-products in the reaction can be reduced, and the purity of the product can be improved. DETAILED DESCRIPTION

[0020] The present application will be further described below in conjunction with specific examples, but the scope of protection of the present application is not limited thereto.

[0021] In the synthesis process of solvent blue 104, NMP is used as a solvent, boric acid and salicylic acid are used as catalysts, 1,4-dihydroxyanthraquinone leuco body is used as an initiator, 1,4-dihydroxyanthraquinone and mesitylamine are used as reaction raw materials to prepare the product solvent blue 104, and NMP is recycled for reuse.

[0022] The main components of the mother liquor and the washing water recovered by the present application are NMP and water, and the kettle type rectification column used for distillation is a batch distillation column with a distillation kettle. During the distillation process, water is first distilled out, and then NMP is distilled out. Among them, the main content of the recovered NMP is controlled to be more than 98%, so as to avoid the influence of low content of the recovered NMP on the reuse.

[0023] The processes of recovering the mother liquor and washing water and separating and recovering NMP in the following multiple examples are the same. NMP is a conventional solvent in the technical field, and the specific separation and recovery process will not be described in detail. The raw materials used in the examples are commercially available industrial products suitable for dye and intermediate production, unless otherwise specified.

[0024] Example 1

[0025] The present embodiment provides a process for producing solvent blue 104 by solvent method, which comprises the following steps:

[0026] (a) 600 kg of fresh NMP as solvent was added to the condensation reactor, and p-mesitylamine 180 kg, 1,4-dihydroxyanthraquinone 200 kg, 1,4-dihydroxyanthraquinone cryptate 60 kg, boric acid 16 kg, and salicylic acid 2 kg were sequentially added. After the addition of the materials was completed, the reactor was closed and heated. The temperature was raised to 120°C in 1.5 hours, and the temperature was maintained for 3 hours. Then the temperature was raised to 140°C, and the temperature was maintained for 12 hours. After the maintenance was completed, the end point was detected by sampling;

[0027] (b) The oxidation reactor was preheated to 50°C. Nitrogen was introduced into the condensation reactor in step (a) to pressurize the reactor, and the materials in the reactor were slowly transferred into the oxidation reactor. After confirming that the materials in the condensation reactor were completely transferred, nitrogen was used to blow the remaining materials in the transfer pipeline to avoid pipeline blockage.

[0028] (c) After the oxidation reactor was stirred and the temperature was controlled at 70°C, 110 kg of potassium hydroxide was added in portions. The temperature was controlled to be not higher than 90°C. After the temperature was stably maintained at 85°C for about 40 minutes, the bottom valve was opened to introduce air for oxidation for 9 hours. During the oxidation, the temperature was controlled at 85°C, the air flow rate was controlled at 10 m³ / h, and attention was paid to the air flow rate of the oil-water separator and the size of the condensate to avoid material overflow.

[0029] (d) After the oxidation time was up, the bottom valve was closed to stop the air introduction, and the materials were stirred for 1 hour. After the temperature was lowered to 45°C, the materials were discharged. The mother liquor was drained and collected into a mother liquor recovery reactor. The materials were washed with 60°C warm water in portions, and the washing water was collected into the mother liquor recovery reactor. The mother liquor and the washing water were transferred into the reactor column of a column distillation tower, and NMP was recovered by distillation.

[0030] (e) The filter cake was washed with 85°C hot water until the cake was neutral and the water was clear. The cake was dried to obtain dry solvent blue 104.

[0031] Example 2

[0032] The present example provides a process for producing solvent blue 104 by a solvent method, which comprises the following steps:

[0033] (a) 960 kg of fresh NMP as solvent was added to the condensation reactor, and p-mesitylamine 240 kg, 1,4-dihydroxyanthraquinone 240 kg, 1,4-dihydroxyanthraquinone cryptate 96 kg, boric acid 24 kg, and salicylic acid 4.8 kg were sequentially added. After the addition of the materials was completed, the reactor was closed and heated. The temperature was raised to 122°C in 2 hours, and the temperature was maintained for 3 hours. Then the temperature was raised to 142°C, and the temperature was maintained for 12 hours. After the maintenance was completed, the end point was detected by sampling;

[0034] (b) The oxidation reactor was preheated to 55°C. Nitrogen was introduced into the condensation reactor in step (a) to pressurize the reactor, and the materials in the reactor were slowly transferred into the oxidation reactor. After confirming that the materials in the condensation reactor were completely transferred, nitrogen was used to blow the remaining materials in the transfer pipeline to avoid pipeline blockage.

[0035] (c) After the oxidation reactor is completed, stir and control the temperature at 80°C. During this period, add 144 kg of potassium hydroxide in batches, and control the reactor temperature to not exceed 90°C. Stir evenly for about 40 minutes until the temperature stabilizes at 90°C. Open the bottom valve to allow air to circulate for oxidation for 9 hours. During this period, control the temperature at 90°C and control the air flow rate at 12 m³ / h. Pay attention to the air flow rate of the oil-water separator and the amount of condensate to avoid material overflow.

[0036] (d) When the oxidation time is up, close the bottom valve to stop the gas supply, stir for 1 hour, cool down to 50°C and discharge the material. The mother liquor is dried and collected in the mother liquor recovery vessel. The material is washed several times with 70°C warm water. The washing water is collected in the mother liquor recovery vessel. The mother liquor and washing water are transferred to the kettle of the kettle-type distillation column for distillation separation and recovery of NMP.

[0037] (e) Wash the filter cake with hot water at 85°C until it is neutral and the water is clear, then dry it to obtain Solvent Blue 104 dry product.

[0038] Example 3

[0039] This embodiment provides a process for producing Solvent Blue 104 using a solvent method, including the following steps:

[0040] (a) Add 750 kg of fresh NMP as solvent to the condensation reactor, and then add 195 kg of p-trisylamine, 200 kg of 1,4-dihydroxyanthraquinone, 70 kg of cryptic 1,4-dihydroxyanthraquinone, 18 kg of boric acid, and 3 kg of salicylic acid in sequence. After the addition is completed, close the reactor and raise the temperature to 121°C in 1.8 hours and hold for 3 hours. After the holding time is up, raise the temperature to 141°C and hold for 12 hours. After the holding time is completed, take a sample to test the endpoint.

[0041] (b) Preheat the oxidation reactor to 53°C, pressurize the condensation reactor in step (a) with nitrogen gas, and slowly transfer the material in the reactor into the oxidation reactor. After confirming that the material in the condensation reactor has been transferred, use nitrogen gas to blow out the remaining material in the transfer tank pipeline to avoid pipeline blockage.

[0042] (c) After the oxidation reactor is completed, stir and control the temperature at 75°C. During this period, add 120 kg of potassium hydroxide in batches, and control the reactor temperature to not exceed 90°C. Stir evenly for about 40 minutes until the temperature stabilizes at 88°C. Open the bottom valve to allow air to circulate for oxidation for 9 hours. During this period, control the temperature at 88°C and control the air flow rate at 11 m³ / h. Pay attention to the air flow rate of the oil-water separator and the amount of condensate to avoid material overflow.

[0043] (d) When the oxidation time is up, close the bottom valve to stop the gas supply, stir for 1 hour, cool down to 47°C and then discharge the material. The mother liquor is dried and collected in the mother liquor recovery vessel. The material is washed several times with 65°C warm water. The washing water is collected in the mother liquor recovery vessel. The mother liquor and washing water are transferred to the kettle of the kettle-type distillation column for distillation separation and recovery of NMP.

[0044] (e) Wash the filter cake with hot water at 85°C until it is neutral and the water is clear, then dry it to obtain Solvent Blue 104 dry product.

[0045] Example 4

[0046] This embodiment is basically the same as Embodiment 3 above in terms of material input, process conditions and steps, except that:

[0047] In step (a) of this embodiment, 750 kg of NMP recovered in Example 3 above is added to the condensation reactor as a solvent, and finally Solvent Blue 104 dry product is obtained.

[0048] Example 5

[0049] This embodiment provides a process for producing Solvent Blue 104 using a solvent method, including the following steps:

[0050] (a) Add 650 kg of NMP recovered in Example 4 above as a solvent to the condensation reactor, and then add 200 kg of p-tristoline, 200 kg of 1,4-dihydroxyanthraquinone, 65 kg of cryptic 1,4-dihydroxyanthraquinone, 20 kg of boric acid, and 4 kg of salicylic acid in sequence. After the addition is completed, close the reactor and raise the temperature to 122°C in 1.6 hours and hold for 3 hours. After the holding time is up, raise the temperature to 140°C and hold for 12 hours. After the holding time is up, take a sample to test the endpoint.

[0051] (b) Preheat the oxidation reactor to 52°C, pressurize the condensation reactor in step (a) with nitrogen, and slowly transfer the material in the reactor into the oxidation reactor. After confirming that the material in the condensation reactor has been transferred, use nitrogen to blow out the remaining material in the transfer tank pipe to avoid blockage of the pipe.

[0052] (c) After the oxidation reactor is completed, stir and control the temperature at 78°C. During this period, add 120 kg of potassium hydroxide in batches, and control the reactor temperature to not exceed 90°C. Stir evenly for about 40 minutes until the temperature stabilizes at 88°C. Open the bottom valve to allow air to circulate for oxidation for 9 hours. During this period, control the temperature at 88°C and control the air flow rate at 10 m³ / h. Pay attention to the air flow rate of the oil-water separator and the amount of condensate to avoid material overflow.

[0053] (d) When the oxidation time is up, close the bottom valve to stop the gas supply, stir for 1 hour, cool down to 46°C and discharge the material. The mother liquor is dried and collected in the mother liquor recovery vessel. The material is washed several times with 68°C warm water. The washing water is collected in the mother liquor recovery vessel. The mother liquor and washing water are transferred to the kettle of the kettle-type distillation column for distillation separation and recovery of NMP.

[0054] (e) Wash the filter cake with hot water at 85°C until it is neutral and the water is clear, then dry it to obtain Solvent Blue 104 dry product.

[0055] Example 6 (Comparative)

[0056] This embodiment is basically the same as Embodiment 3 above in terms of material input, process conditions and steps, except that:

[0057] In step (c), the air flow rate is controlled at 5 m³ / h, and finally Solvent Blue 104 dry product is obtained.

[0058] Example 7 (Comparative)

[0059] This embodiment is basically the same as Embodiment 3 above in terms of material input, process conditions and steps, except that:

[0060] In step (c), the air flow rate is controlled at 17 m³ / h, and finally Solvent Blue 104 dry product is obtained.

[0061] The specific product results data for all the above embodiments and comparative examples are shown in the table below.

[0062] No. Solvent origin Conversion Workup yield Product DE value Example 1 Freshly added 83.3% 93.1% 0.20 Example 2 Freshly added 82.6% 92.8% 0.18 Example 3 Freshly added 83.6% 93.6% 0.21 Example 4 Recovery 82.8% 92.3% 0.26 Example 5 Recovery 82.4% 92.6% 0.22 Example 6 Freshly added 70.2% 76.4% 0.95 Example 7 Freshly added 68.4% 70.9% 0.62

[0063] This invention collects the mother liquor and washing liquid, then distills and recovers the solvent NMP for reuse, reducing production costs and the organic content in wastewater. By using a specific air flow rate, it ensures a high conversion rate and yield of the product, reduces waste emissions, and helps mitigate environmental pollution.

Claims

1. A process for producing Solvent Blue 104 using a solvent method, characterized in that, Includes the following steps: (a) Add N-methylpyrrolidone (NMP) as a solvent to the condensation reactor, and then add p-trisylamine, 1,4-dihydroxyanthraquinone, 1,4-dihydroxyanthraquinone leuco, boric acid, and salicylic acid in sequence. After the addition is completed, close the reactor and raise the temperature to 120-122°C in 1.5-2 hours, and hold for 3 hours. After the holding time is up, raise the temperature to 140-142°C and hold for 12 hours. After the holding time is completed, take a sample to test the endpoint. The mass ratio of 1,4-dihydroxyanthraquinone to NMP is 1:(3-4), the mass ratio of 1,4-dihydroxyanthraquinone to trimethylolamine and 1,4-dihydroxyanthraquinone leucoform is 1:(0.9-1):(0.3-0.4), and the mass ratio of 1,4-dihydroxyanthraquinone to boric acid and salicylic acid is 1:(0.08-0.1):(0.01-0.02). (b) Preheat the oxidation reactor to 50-55°C, pressurize the condensation reactor in step (a) with nitrogen gas, and slowly transfer the material in the reactor into the oxidation reactor. After confirming that the material in the condensation reactor has been transferred, use nitrogen gas to blow out the remaining material in the transfer tank pipeline to avoid pipeline blockage. (c) After the transfer is completed, the temperature of the oxidation reactor is controlled at 70-80℃. During this period, potassium hydroxide is added in batches, and the temperature of the reactor is controlled not to exceed 90℃. After stirring evenly for about 40 minutes, the temperature is stabilized at 85-90℃. The bottom valve is opened to allow air to oxidize for 9 hours, during which the temperature is controlled at 85-90℃ and the air flow rate is controlled at 10-12m³ / h. (d) When the oxidation time is up, close the bottom valve to stop the gas supply, stir for 1 hour, cool down to 45-50℃ and then discharge the material. The mother liquor is dried and collected in the mother liquor recovery vessel. The material is washed several times with 60-70℃ warm water. The washing water is collected in the mother liquor recovery vessel. The mother liquor and washing water are transferred to the kettle of the kettle-type distillation column for distillation separation and recovery of NMP. (e) Wash the filter cake with hot water at 85°C until it is neutral and the water is clear, then dry it to obtain Solvent Blue 104 dry product.

2. The process for producing Solvent Blue 104 by solvent method according to claim 1, characterized in that: In step (a), the endpoint analysis method used is thin-layer chromatography (TLC). The developing solvent is a mixture of toluene and acetone, and the solvent is chloroform. The endpoint is defined as no spots or only trace purple spots on the developing layer.

3. The process for producing Solvent Blue 104 by solvent method according to claim 1, characterized in that: Starting from the second batch, the NMP used in step (a) will preferentially use the NMP recovered in step (f).

4. The process for producing Solvent Blue 104 by solvent method according to claim 1, characterized in that: In step (c), the total mass of potassium hydroxide added is in the mass ratio of 1,4-dihydroxyanthraquinone to (0.55-0.6):1.