Production method of low-chromaticity TCPP

Abstract

The invention relates to the technical field of production of TCPP, in particular to a production method of low-chroma TCPP. The invention relates to a production method of low-chroma TCPP. The production method comprises the following steps: S1, adding phosphorus oxychloride and a Lewis acid catalyst into a reaction kettle, and heating; s2, adding an antioxidant and an antioxidant aid into the reaction kettle, mixing with the mixture a to obtain a mixture b, adding epoxypropane into the mixture b, and carrying out heat preservation to obtain a TCPP crude product; s3, carrying out alkali washing and water washing on the TCPP crude product, and then dehydrating to obtain low-chroma TCPP; according to the production method of the TCPP provided by the invention, the low-chroma TCPP can be obtained, and the moisture content can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of TCPP production, and in particular to a method for producing low-chroma TCPP. Background Art

[0002] TCPP (tris(2-chloropropyl) phosphate) is a highly efficient phosphorus-based flame retardant. TCPP is used in fire-retardant coatings, polyurethane soft and hard foams, polyvinyl chloride and engineering plastics and other technical fields. In the process of producing TCPP, when the feed rate of propylene oxide is too fast, the temperature of the reaction between phosphorus oxychloride and propylene oxide will exceed 70°C, and in the dehydration process, the dehydration temperature is too high and the dehydration time is too long, which will also cause the formed TCPP to change from the original white transparent state to light yellow, reducing the quality of TCPP; when TCPP changes from the original white transparent state to light yellow, it will affect the synthesis of downstream products, and when the water content in TCPP is high, it will further affect the application of TCPP in downstream.

[0003] The Chinese invention patent with the patent publication number CN116239631A discloses a method for preparing a TCPP flame retardant, and the Chinese invention patent with the patent publication number CN115466283A discloses a method for preparing a low-odor flame retardant TCPP. These TCPP-related patents do not disclose a technical solution to the problem of TCPP being transformed from its original white transparent state to light yellow. Therefore, providing a production method that can solve the problem of TCPP being transformed from its original white transparent state to light yellow under the premise of ensuring that the moisture content in TCPP is qualified is the main technical problem that needs to be solved at present. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for producing TCPP, comprising the following steps:

[0005] S1. adding phosphorus oxychloride and a Lewis acid catalyst into a reaction vessel and heating to obtain a mixture a;

[0006] S2. The antioxidant and antioxidant aid were added to the reactor and mixed with the mixture a to obtain a mixture b, and then propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product;

[0007] S3. The crude TCPP product is alkali washed, washed with water, and then dehydrated to obtain TCPP;

[0008] The mass ratio of the antioxidant to the antioxidant aid is (4-6):1.

[0009] In one embodiment, the mass ratio of the antioxidant to the antioxidant aid is (5-5.1):1.

[0010] In one embodiment, the antioxidant comprises a hindered phenolic antioxidant, and the hindered phenolic antioxidant comprises antioxidant 1076.

[0011] In one embodiment, the antioxidant is antioxidant 1076.

[0012] In one embodiment, the antioxidant auxiliary agent includes a phosphite antioxidant, and the phosphite antioxidant includes antioxidant 626.

[0013] In one embodiment, the antioxidant adjuvant is antioxidant 626.

[0014] In order to solve the problem of TCPP being transformed from its original white transparent state to light yellow, the inventors found during the experiment that when antioxidant 1076 and antioxidant 626 are used in combination, the mass ratio of antioxidant 1076 to antioxidant 626 is (4-6):1, especially when the mass ratio of antioxidant 1076 to antioxidant 626 is (5-5.1):1, the problem of TCPP being transformed from its original white transparent state to light yellow can be solved, and the platinum-cobalt color number of the obtained TCPP is reduced to less than 6, thereby obtaining low-chroma TCPP. The inventors found during the experiment that when antioxidant 626 is not used or the mass ratio of antioxidant 1076 to antioxidant 626 is not within the range of (4-6):1, the platinum-cobalt color number of the obtained TCPP after dehydration for 6 hours will be greater than 7, and the numerical change of the platinum-cobalt color number is unstable.

[0015] In one embodiment, the Lewis acid catalyst is anhydrous aluminum chloride.

[0016] In one embodiment, the antioxidant and antioxidant auxiliary are added in an amount of 0.5-1.5 wt % of the amount of phosphorus oxychloride and propylene oxide added.

[0017] In one embodiment, the antioxidant and antioxidant auxiliary are added in an amount of 0.5-1.2 wt % of the amount of phosphorus oxychloride and propylene oxide added.

[0018] In order to obtain low-color TCPP, the inventors found during the experiment that by using an antioxidant and an antioxidant aid in an amount of 0.5-1.5wt% of the amount of phosphorus oxychloride and propylene oxide, especially when the antioxidant and the antioxidant aid are added in an amount of 0.5-1.2wt% of the amount of phosphorus oxychloride and propylene oxide, the platinum-cobalt color number of the obtained TCPP is reduced to less than 6, thereby obtaining low-color TCPP.

[0019] In one embodiment, the heating is performed in S1 until the Lewis acid catalyst is dissolved in phosphorus oxychloride.

[0020] In one embodiment, in S2, propylene oxide is added dropwise to the mixture b, and the temperature of the reactor is maintained at 60-65°C.

[0021] In one embodiment, in S2, propylene oxide is added dropwise to the mixture b, and the temperature of the reactor is maintained at, including but not limited to, 60°C, 61°C, 62°C, 63°C, 64°C, and 65°C.

[0022] In one embodiment, the temperature for insulation in S2 is 60-65° C., and the insulation time is 1-5 hours.

[0023] In one embodiment, the temperature for insulation in S2 includes but is not limited to 60°C, 61°C, 62°C, 63°C, 64°C, and 65°C.

[0024] In one embodiment, the insulation time in S2 is 2-4 hours.

[0025] In one embodiment, the temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0026] In one embodiment, in S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0027] In one embodiment, the temperature in the dehydration kettle is 170-190° C., and the pressure in the dehydration kettle is -98 to -80 kPa.

[0028] In order to reduce the moisture content in TCPP, the inventors found during the experiment that by maintaining the temperature of the reactor at 60-65°C, the insulation temperature at 60-65°C, the insulation time at 1-5h, the temperature in the dehydration kettle at 170-190°C, the pressure in the dehydration kettle at -98 to -80kPa, and the dehydration time of the dehydration kettle at 4-8h, the moisture content in TCPP can be less than 0.05%, and the obtained TCPP will not increase its platinum-cobalt color number as the dehydration time increases, and has good stability.

[0029] In one embodiment, the temperature in the dehydration kettle includes but is not limited to 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C, 180°C, 181°C, 182°C, 183°C, 184°C, 185°C, 186°C, 187°C, 188°C, 189°C, and 190°C.

[0030] In one embodiment, the pressure in the dehydration kettle includes but is not limited to -80kPa, -81kPa, -82kPa, -83kPa, -84kPa, -85kPa, -86kPa, -87kPa, -88kPa, -89kPa, -90kPa, -91kPa, -92kPa, -93kPa, -94kPa, -95kPa, -96kPa, -97kPa, and -98kPa.

[0031] In one embodiment, the dehydration kettle performs dehydration for 4-8 hours.

[0032] In one embodiment, the dehydration time of the dehydration kettle includes but is not limited to 4h, 5h, 6h, 7h, and 8h.

[0033] In one embodiment, the dehydration kettle performs dehydration for 6 hours.

[0034] In order to solve the problem of TCPP being transformed from its original white transparent state to light yellow and reduce the moisture content in TCPP, the inventors found in the experimental process that the antioxidant and the antioxidant auxiliary agent are used in the present application for coordination, the mass ratio of the antioxidant and the antioxidant auxiliary agent is (4-6):1, especially when the mass ratio of the antioxidant and the antioxidant auxiliary agent is (5-5.1):1, the antioxidant used is antioxidant 1076, the antioxidant auxiliary agent used is antioxidant 626, the amount of the antioxidant and the antioxidant auxiliary agent added is 0.5-1.5wt% of the amount of phosphorus oxychloride and propylene oxide added, especially the antioxidant When the amount of the antioxidant added is 0.5-1.2wt% of the amount of trichloride and propylene oxide added, by maintaining the temperature of the reactor at 60-65°C, the insulation temperature is 60-65°C, the insulation time is 1-5h, the temperature in the dehydration kettle is set to 170-190°C, the pressure in the dehydration kettle is set to -98 to -80kPa, and the dehydration time of the dehydration kettle is 4-8h, low-color TCPP can be obtained, and the moisture content in the TCPP is less than 0.05%, and the obtained TCPP does not increase its platinum-cobalt color number as the dehydration time increases, and has good stability.

[0035] Beneficial Effects

[0036] 1. The TCPP production method provided in this application can obtain low-color TCPP, does not affect the synthesis of TCPP in downstream products, and does not affect the application of TCPP in downstream.

[0037] 2. In the present application, antioxidant 1076 and antioxidant 626 are used in combination, and the mass ratio of antioxidant 1076 and antioxidant 626 is (4-6):1, especially when the mass ratio of antioxidant 1076 and antioxidant 626 is (5-5.1):1, the platinum-cobalt color number of the obtained TCPP is reduced to less than 6 to obtain low-color TCPP.

[0038] 3. In the present application, the amount of antioxidants and antioxidant aids added is 0.5-1.5wt% of the amount of phosphorus oxychloride and propylene oxide added, especially when the amount of antioxidants and antioxidant aids added is 0.5-1.2wt% of the amount of phosphorus oxychloride and propylene oxide added, the platinum-cobalt color number of TCPP can be reduced.

[0039] 4. In the present application, low-color TCPP can be obtained by using antioxidants and antioxidant aids in an amount of 0.5-1.5wt% of phosphorus oxychloride and propylene oxide, especially when the antioxidants and antioxidant aids are added in an amount of 0.5-1.2wt% of phosphorus oxychloride and propylene oxide.

[0040] 5. In the present application, by maintaining the temperature of the reactor at 60-65°C, the insulation temperature at 60-65°C, the insulation time at 1-5h, the temperature in the dehydration kettle at 170-190°C, the pressure in the dehydration kettle at -98 to -80kPa, and the dehydration time of the dehydration kettle at 4-8h, the moisture content in TCPP can be made less than 0.05%, and the obtained TCPP does not increase its platinum-cobalt color number with the increase of dehydration time, and has good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The left bottle in the middle contains TCPP provided by Comparative Example 4, and the right bottle contains TCPP provided by Example 1. DETAILED DESCRIPTION

[0042] The manufacturers and models of the raw materials used in Examples 1-2 and Comparative Examples 1-4 of the present application are as follows:

[0043] The phosphorus oxychloride is purchased from Nantong Jiangshan Pesticide Chemical Co., Ltd., with POCl3≥99.5%, PCl3 residue≤0.2%, and distillation range of 105-109°C.

[0044] The anhydrous aluminum chloride is purchased from Henan Shenma Chlor-Alkali Chemical Co., Ltd., and its AlCl3≥98.5%, Fe 3+ ≤0.08%.

[0045] The antioxidant 1076 was purchased from Shenzhen Zhenqiang Biotechnology Co., Ltd., and its HPLC content was ≥95%.

[0046] The antioxidant 1010 was purchased from Tianjin Lianlong New Materials Co., Ltd., and its purity was ≥94%.

[0047] The antioxidant 626 was purchased from Shanghai MacLean Biochemical Technology Co., Ltd., and its purity was ≥95%.

[0048] The propylene oxide is purchased from Ningbo Zhenhai Refining and Chemical Lyondell Chemical Co., Ltd. The propylene oxide (w / %) is ≥99.95%, the acidity (calculated as acetic acid) (w / %) is ≤0.003, and the water content (w / %) is ≤0.020.

[0049] Example 1

[0050] This embodiment provides a method for producing low-chroma TCPP, comprising the following steps:

[0051] S1. Phosphorus oxychloride and a Lewis acid catalyst were added to a reaction vessel and heated with stirring to obtain a mixture a, wherein the stirring speed was 88 r / min;

[0052] S2. The antioxidant and antioxidant aid were added to the reactor and the mixture a was stirred to obtain a mixture b, the stirring speed was 88r / min, and then propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product;

[0053] S3. The crude TCPP product is subjected to alkali washing, water washing, and then dehydrated to obtain TCPP.

[0054] The Lewis acid catalyst is anhydrous aluminum chloride.

[0055] The antioxidant is antioxidant 1076.

[0056] The antioxidant auxiliary agent is antioxidant 626.

[0057] The amount of phosphorus oxychloride added in S1 is 14879 kg, and the amount of anhydrous aluminum chloride added is 36.85 kg.

[0058] The amount of antioxidant 1076 added to S2 is 147.12 kg, the amount of antioxidant auxiliary 626 added is 29.42 kg, and the amount of propylene oxide added is 15710.5 kg.

[0059] In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

[0060] In the step S2, propylene oxide is added dropwise to the mixture b, the adding time is controlled to be 1 hour, and the temperature of the reactor is maintained at 60°C.

[0061] The temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0062] In S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0063] The temperature in the dehydration kettle is 180° C., and the pressure in the dehydration kettle is -80 kPa.

[0064] The dehydration time of the dehydration kettle is 6 hours.

[0065] Example 2

[0066] This embodiment provides a method for producing low-chroma TCPP, comprising the following steps:

[0067] S1. Phosphorus oxychloride and a Lewis acid catalyst were added to a reaction vessel and heated with stirring to obtain a mixture a, wherein the stirring speed was 88 r / min;

[0068] S2. The antioxidant and antioxidant aid were added to the reactor and the mixture a was stirred to obtain a mixture b, the stirring speed was 88r / min, and then propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product;

[0069] S3. The crude TCPP product is subjected to alkali washing, water washing, and then dehydrated to obtain TCPP.

[0070] The Lewis acid catalyst is anhydrous aluminum chloride.

[0071] The antioxidant is antioxidant 1076.

[0072] The antioxidant auxiliary agent is antioxidant 626.

[0073] The amount of phosphorus oxychloride added in S1 is 14870 kg, and the amount of anhydrous aluminum chloride added is 36.85 kg.

[0074] The amount of antioxidant 1076 added to S2 is 294.33 kg, the amount of antioxidant auxiliary 626 added is 58.54 kg, and the amount of propylene oxide added is 15626.5 kg.

[0075] In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

[0076] In the step S2, propylene oxide is added dropwise to the mixture b, the adding time is controlled to be 1 hour, and the temperature of the reactor is maintained at 60°C.

[0077] The temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0078] In S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0079] The temperature in the dehydration kettle is 180° C., and the pressure in the dehydration kettle is -98 kPa.

[0080] The dehydration time of the dehydration kettle is 6 hours.

[0081] Comparative Example 1

[0082] Comparative Example 1 provides a method for producing TCPP, comprising the following steps:

[0083] S1. Phosphorus oxychloride and a Lewis acid catalyst were added to a reaction vessel and heated with stirring to obtain a mixture a, wherein the stirring speed was 88 r / min;

[0084] S2. The antioxidant was added to the reactor and the mixture a was stirred to obtain a mixture b, the stirring speed was 88r / min, and then propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product;

[0085] S3. The crude TCPP product is subjected to alkali washing, water washing, and then dehydrated to obtain TCPP.

[0086] The Lewis acid catalyst is anhydrous aluminum chloride.

[0087] The antioxidant is antioxidant 1076.

[0088] The amount of phosphorus oxychloride added in S1 is 14353 kg, and the amount of anhydrous aluminum chloride added is 35.5 kg.

[0089] The amount of antioxidant 1076 added to the S2 is 154.48 kg, and the amount of propylene oxide added is 16496.5 kg.

[0090] In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

[0091] In the step S2, propylene oxide is added dropwise to the mixture b, the adding time is controlled to be 1 hour, and the temperature of the reactor is maintained at 60°C.

[0092] The temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0093] In S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0094] The temperature in the dehydration kettle is 180° C., and the pressure in the dehydration kettle is -98 kPa.

[0095] The dehydration time of the dehydration kettle is 6 hours.

[0096] Comparative Example 2

[0097] Comparative Example 2 provides a method for producing TCPP, comprising the following steps:

[0098] S1. Phosphorus oxychloride and a Lewis acid catalyst were added to a reaction vessel and heated with stirring to obtain a mixture a, wherein the stirring speed was 88 r / min;

[0099] S2. The antioxidant and antioxidant aid were added to the reactor and the mixture a was stirred to obtain a mixture b, the stirring speed was 88r / min; propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product;

[0100] S3. The crude TCPP product is subjected to alkali washing, water washing, and then dehydrated to obtain TCPP.

[0101] The Lewis acid catalyst is anhydrous aluminum chloride.

[0102] The antioxidant is antioxidant 1076.

[0103] The antioxidant auxiliary agent is antioxidant 626.

[0104] The amount of phosphorus oxychloride added in S1 is 13569 kg, and the amount of anhydrous aluminum chloride added is 33.6 kg.

[0105] The amount of antioxidant 1076 added to S2 is 29.4 kg, the amount of antioxidant auxiliary 626 added is 29.42 kg, and the amount of propylene oxide added is 14327.2 kg.

[0106] In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

[0107] In the step S2, propylene oxide is added dropwise to the mixture b, the adding time is controlled to be 1 hour, and the temperature of the reactor is maintained at 60°C.

[0108] The temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0109] In S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0110] The temperature in the dehydration kettle is 180° C., and the pressure in the dehydration kettle is -98 kPa.

[0111] The dehydration time of the dehydration kettle is 6 hours.

[0112] Comparative Example 3

[0113] Comparative Example 3 provides a method for producing TCPP, comprising the following steps:

[0114] S1. Phosphorus oxychloride and a Lewis acid catalyst were added to a reaction vessel and heated with stirring to obtain a mixture a, wherein the stirring speed was 88 r / min;

[0115] S2. The antioxidant and antioxidant aid were added to the reactor and the mixture a was stirred to obtain a mixture b, the stirring speed was 88r / min; propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product;

[0116] S3. The crude TCPP product is subjected to alkali washing, water washing, and then dehydrated to obtain TCPP.

[0117] The Lewis acid catalyst is anhydrous aluminum chloride.

[0118] The antioxidant is antioxidant 1010.

[0119] The antioxidant auxiliary agent is antioxidant 626.

[0120] The amount of phosphorus oxychloride added in S1 is 14580 kg, and the amount of anhydrous aluminum chloride added is 36.13 kg.

[0121] The amount of antioxidant 1010 added to S2 is 144.17 kg, the amount of antioxidant auxiliary 626 added is 57.36 kg, and the amount of propylene oxide added is 15313.5 kg.

[0122] In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

[0123] In the step S2, propylene oxide is added dropwise to the mixture b, the adding time is controlled to be 1 hour, and the temperature of the reactor is maintained at 60°C.

[0124] The temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0125] In S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0126] The temperature in the dehydration kettle is 180° C., and the pressure in the dehydration kettle is -98 kPa.

[0127] The dehydration time of the dehydration kettle is 6 hours.

[0128] Comparative Example 4

[0129] Comparative Example 4 provides a method for producing TCPP, comprising the following steps:

[0130] S1. Phosphorus oxychloride and a Lewis acid catalyst were added to a reaction vessel and heated with stirring to obtain a mixture a, wherein the stirring speed was 88 r / min;

[0131] S2. The propylene oxide was added to the mixture a and stirred at a stirring speed of 88r / min, and the crude TCPP product was obtained by heat preservation;

[0132] S3. The crude TCPP product is subjected to alkali washing, water washing, and then dehydrated to obtain TCPP.

[0133] The Lewis acid catalyst is anhydrous aluminum chloride.

[0134] The amount of phosphorus oxychloride added in S1 is 13575 kg, and the amount of anhydrous aluminum chloride added is 34 kg.

[0135] The amount of propylene oxide added in S2 is 15710.5 kg.

[0136] In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

[0137] In the step S2, propylene oxide is added dropwise to the mixture a, the adding time is controlled to be 1 hour, and the temperature of the reactor is maintained at 60°C.

[0138] The temperature for insulation in S2 is 60° C. and the insulation time is 3 hours.

[0139] In S3, the crude TCPP product is subjected to alkali washing, primary water washing, and secondary water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

[0140] The temperature in the dehydration kettle is 180° C., and the pressure in the dehydration kettle is -98 kPa.

[0141] The dehydration time of the dehydration kettle is 6 hours.

[0142] Performance Testing

[0143] 1. Chroma test:

[0144] The platinum-cobalt color number of the TCPP provided in Examples 1-2 and Comparative Examples 1-4 after dehydration for 6 hours was tested using a Hunterlab VIATA colorimeter. The test results are shown in Table 1.

[0145] 2. Moisture content test

[0146] The moisture content of the TCPP provided in Examples 1-2 and Comparative Examples 1-4 was tested using a moisture tester. The test results are shown in Table 1.

[0147] 3. Chromatographic test

[0148] The peak time and peak area of ​​TCPP content provided in Examples 1-2 and Comparative Examples 1-4 were tested using an Agilent 8890 gas chromatograph. The test results are shown in Tables 2 and 3.

[0149] 4. Stability test

[0150] The change of platinum-cobalt color number of TCPP provided by Examples 1-2 and Comparative Examples 1-4 at different dehydration times (1h, 2h, 3h, 4h, 5h, 6h) was tested using a Hunterlab VIATA colorimeter. The test results are shown in Table 4.

[0151] 5. Appearance status test

[0152] The appearance of the TCPP provided in Example 1 and Comparative Example 4 after dehydration for 6 hours is shown in FIG. Figure 1 .

[0153] Table 1

[0154] Example Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Platinum Cobalt Color 5.68 5.74 7.58 8.55 7.83 15.11 Moisture content Less than 0.05% Less than 0.05% Less than 0.05% Less than 0.05% Less than 0.05% Less than 0.05%

[0155] Table 2

[0156]

[0157] Table 3

[0158]

[0159] Table 4

[0160]

[0161]

[0162] It can be seen from the test results in Table 4 that when antioxidant 1076 and antioxidant 626 are used in Example 1 and Example 2, and the mass ratio of antioxidant 1076 to antioxidant 626 is (5-5.1): 1, the platinum-cobalt color number of the obtained TCPP can be reduced, and the platinum-cobalt color number of the obtained TCPP after dehydration for 6 hours is less than 6, and has good platinum-cobalt color number stability. It can be seen from Comparative Examples 1-4 that when antioxidant 626 and antioxidant 1076 are not used, or the mass ratio of antioxidant 1076 to antioxidant 626 is not within the range of (4-6): 1, the platinum-cobalt color number of the obtained TCPP after dehydration for 6 hours will be greater than 7, and the numerical change of the platinum-cobalt color number is unstable.

[0163] pass Figure 1 It can be seen that in the TCPP production method provided in Comparative Example 4, antioxidant 1076 and antioxidant 626 are not used, and the platinum-cobalt color number of the obtained TCPP after dehydration for 6 hours reaches 15.11, showing a yellow state.

[0164] The content description provided in this application is illustrative and is not intended to limit the scope of this application to the above-mentioned embodiments. The above-mentioned implementation modes provided in this application are merely specific implementation cases for the inventive concepts provided in this application. Therefore, this application is not limited by the above-mentioned embodiments. Under the inventive concepts provided in this application, technical solutions obtained by supplementing or modifying the above-mentioned implementation cases of this application or replacing them in a similar manner should all fall within the scope of protection of the present invention.

Claims

1. A method for producing low-chroma TCPP, characterized in that: The following steps are involved: S1. adding phosphorus oxychloride and a Lewis acid catalyst into a reaction vessel and heating to obtain a mixture a; S2. The antioxidant and antioxidant aid were added to the reactor and mixed with the mixture a to obtain a mixture b, and then propylene oxide was added to the mixture b, and the mixture was insulated to obtain a crude TCPP product; S3. The crude TCPP product is alkali washed, washed with water, and then dehydrated to obtain low-color TCPP; The mass ratio of the antioxidant to the antioxidant aid is (4-6):

1.

2. The method for producing low-chroma TCPP according to claim 1, wherein: The antioxidant includes a hindered phenol antioxidant, and the hindered phenol antioxidant includes antioxidant 1076.

3. The method for producing low-chroma TCPP according to claim 1, wherein: The antioxidant aid includes a phosphite antioxidant, and the phosphite antioxidant includes antioxidant 626.

4. The method for producing low-chroma TCPP according to any one of claims 1 to 3, characterized in that: The added amount of the antioxidant and antioxidant auxiliary is 0.5-1.5wt% of the added amount of phosphorus oxychloride and propylene oxide.

5. The method for producing low-chroma TCPP according to claim 1, wherein: In the step S1, heating is performed until the Lewis acid catalyst is dissolved in the phosphorus oxychloride.

6. The method for producing low-chroma TCPP according to claim 1, characterized in that: In S2, propylene oxide is added dropwise to the mixture b, and the temperature of the reactor is maintained at 60-65°C.

7. The method for producing low-chroma TCPP according to claim 1, wherein: The temperature for insulation in S2 is 60-65° C., and the insulation time is 1-5 hours.

8. The method for producing low-chroma TCPP according to claim 1, wherein: In S3, the crude TCPP product is subjected to alkali washing and water washing to obtain crude TCPP ester, and the crude TCPP ester is dehydrated by a thin film evaporator and then enters a dehydration kettle for dehydration.

9. The method for producing low-chroma TCPP according to claim 8, characterized in that: The temperature in the dehydration kettle is 170-190°C, and the pressure in the dehydration kettle is -98 to -80 kPa.

10. The method for producing low-chroma TCPP according to claim 8, characterized in that: The dehydration time of the dehydration kettle is 4-8h.

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