A post-treatment method for crude antioxidant 168

Abstract

The present invention belongs to the technical field of purification of fine chemical products, and specifically relates to a post-processing method of a crude antioxidant 168. The present invention provides a post-processing method of an antioxidant 168, comprising the following steps: dissolving the crude antioxidant 168 in a benzene solvent, mixing the obtained dissolving solution with water, and performing a hydrolysis reaction to obtain a hydrolysis reaction solution; the hydrolysis reaction solution is sequentially layered, and the obtained organic phase is sequentially concentrated and dried to obtain an antioxidant 168 finished product, and the purity of the antioxidant 168 finished product is >99.3%. The post-processing method provided by the present invention can effectively reduce the content of the by-product tert-butylphenyl bis (2,4-di-tert-butylphenyl) phosphite or (2,4-tert-butylphenyl) bis (di-tert-butylphenyl) phosphite, and improve the purity and hydrolysis resistance of the finished antioxidant 168.

Description

Technical Field

[0001] The invention belongs to the technical field of purification of fine chemical products, and specifically relates to a post-treatment method for a crude antioxidant 168 product. Background Art

[0002] Antioxidant 168 (tris(2,4-di-tert-butylphenyl)phosphite) is a phosphite antioxidant with the characteristics of good hydrolysis resistance, high temperature resistance, low volatility and strong extraction resistance. It can not only effectively decompose the hydroperoxides produced during the thermal processing of polyolefin materials, but also can be used in combination with main antioxidants 1010, 1076, etc. to achieve a synergistic effect. It is widely used in the processing of polymers such as PP, HDPE, LDPE, ABS, and polycarbonate.

[0003] At present, the synthesis method of antioxidant 168 mainly uses 2,4-di-tert-butylphenol and phosphorus trichloride as raw materials, reacts under the action of an organic amine catalyst to produce antioxidant 168 (such as patents CN101798325A, CN102718797 A, and CN110590834A all use this method). However, the above synthesis method will produce by-products such as tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite or (2,4-tert-butylphenyl) bis(di-tert-butylphenyl) phosphite, which reduces the purity and hydrolysis resistance of antioxidant 168. Summary of the invention

[0004] In view of this, the present invention provides a post-treatment method for a crude antioxidant 168 to effectively reduce the content of the by-product tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite or (2,4-tert-butylphenyl) bis(di-tert-butylphenyl) phosphite, and improve the purity and hydrolysis resistance of the antioxidant 168.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a post-treatment method of a crude antioxidant 168, comprising the following steps:

[0006] Dissolving a crude product of antioxidant 168 in a benzene solvent, mixing the obtained solution with water, and performing a hydrolysis reaction to obtain a hydrolysis reaction solution;

[0007] The hydrolysis reaction liquid is layered in sequence, and the obtained organic phase is concentrated and dried in sequence to obtain the finished product of antioxidant 168, and the purity of the finished product of antioxidant 168 is greater than 99.3%.

[0008] Preferably, the temperature of the hydrolysis reaction is 50-75° C., and the insulation time is 15-60 min.

[0009] Preferably, the mass ratio of the crude antioxidant 168 to water is 100:10-60.

[0010] Preferably, the benzene solvent includes one or more of xylene, toluene, chlorobenzene and dichlorobenzene.

[0011] Preferably, the mass ratio of the crude antioxidant 168 to the benzene solvent is 1:0.9-1.2.

[0012] Preferably, before the drying, the concentrate obtained by the concentration is further washed and solid-liquid separated; the washing reagent includes an isopropanol solution.

[0013] Preferably, the mass concentration of the isopropanol solution is 75.00-99.99%.

[0014] Preferably, the drying temperature is 80-90° C. and the drying time is 3-5 hours.

[0015] The present invention provides a post-treatment method of antioxidant 168, comprising the following steps: dissolving a crude product of antioxidant 168 in a benzene solvent, mixing the obtained solution with water, and performing a hydrolysis reaction to obtain a hydrolysis reaction solution; sequentially layering the hydrolysis reaction solution, and sequentially concentrating and drying the obtained organic layer to obtain a finished product of antioxidant 168, wherein the purity of the finished product of antioxidant 168 is greater than 99.3%. According to the different hydrolysis resistances of antioxidant 168 and byproducts tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite and (2,4-tert-butylphenyl) bis(di-tert-butylphenyl) phosphite, water is added to the crude product of antioxidant 168, and the byproducts are hydrolyzed, while antioxidant 168 has a strong hydrolysis resistance and will not be hydrolyzed, thereby achieving the purpose of removing the byproducts. At the same time, the removal of the byproducts improves the hydrolysis resistance of the finished product of antioxidant 168.

[0016] The data of the examples show that the contents of the two by-products in the finished product of antioxidant 168 are lower than 5 ppm, the purity of the finished product of antioxidant 168 can reach 99.61%, and the stability time of antioxidant 168 in the hydrolysis resistance test reaches 20 hours, showing good hydrolysis resistance. DETAILED DESCRIPTION

[0017] The present invention provides a post-treatment method of antioxidant 168, comprising the following steps:

[0018] Dissolving a crude product of antioxidant 168 in a benzene solvent, mixing the obtained solution with water, and performing a hydrolysis reaction to obtain a hydrolysis reaction solution;

[0019] The hydrolysis reaction liquid is layered in sequence, and the obtained organic layer is concentrated and dried in sequence to obtain the finished product of antioxidant 168, and the purity of the finished product of antioxidant 168 is greater than 99.3%.

[0020] The present invention dissolves a crude product of antioxidant 168 in a benzene solvent, mixes the obtained solution with water, and performs a hydrolysis reaction to obtain a hydrolysis reaction solution.

[0021] In the present invention, the method for preparing the crude antioxidant 168 preferably comprises the following steps:

[0022] 2,4-di-tert-butylphenol, xylene, an organic amine catalyst and phosphorus trichloride are mixed to carry out an esterification reaction, and the system obtained by the synthesis reaction is concentrated to dryness to obtain a crude product of antioxidant 168.

[0023] In the present invention, the benzene solvent preferably includes one or more of toluene, xylene, chlorobenzene and dichlorobenzene, and more preferably xylene. In the present invention, the mass ratio of the crude antioxidant 168 to the benzene solvent is preferably 1:0.9-1.2, and more preferably 1:1. In the present invention, the mass ratio of the crude antioxidant 168 to water is preferably 100:10-60, and more preferably 100:20-50.

[0024] In the present invention, the temperature of the hydrolysis reaction is preferably 50-75° C., more preferably 60-70° C.; the insulation time is preferably 15-60 min, more preferably 30-40 min.

[0025] In the present invention, during the hydrolysis reaction, tert-butylphenyl bis(2,4-di-tert-butylphenyl)phosphite or (2,4-tert-butylphenyl)bis(di-tert-butylphenyl)phosphite in the crude antioxidant 168 will be hydrolyzed, while the antioxidant 168 is relatively stable, thereby achieving the separation of the antioxidant 168 from the by-products.

[0026] In the present invention, the tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite has a structure shown in Formula I; the (2,4-tert-butylphenyl) bis(di-tert-butylphenyl) phosphite has a structure shown in Formula II;

[0027]

[0028] In the present invention, in the formula I, R1 is

[0029] In the present invention, in the formula II, R2 and R3 are independently

[0030] After obtaining the hydrolysis reaction liquid, the present invention sequentially layers, concentrates and dries the hydrolysis reaction liquid to obtain the finished product of antioxidant 168.

[0031] In the present invention, the separation is performed to obtain an organic phase and an aqueous phase.

[0032] In the present invention, the concentration is preferably to distill the organic phase under reduced pressure, the temperature of the distillation under reduced pressure is preferably 110-180°C, more preferably 140-150°C, the time is preferably 30-120 min, more preferably 50-70 min. In the present invention, the drying temperature is preferably 80-90°C, more preferably 85±2°C, the drying time is preferably 3-5 h, more preferably 4 h.

[0033] In the present invention, before the drying, it is preferred to include washing and solid-liquid separation. In the present invention, in the present invention, the washing reagent is preferably an isopropanol solution, and the mass concentration of the isopropanol solution is preferably 75.00-99.99%, more preferably 99.00%. In the present invention, the number of washings is preferably ≥2. In the present invention, the solid-liquid separation method is preferably centrifugation; the speed of the centrifugation is preferably 3000-8000rpm, more preferably 5000-6000rpm, and the time is preferably 5-15min, more preferably 7-9min. In the present invention, the washing is preferably washing to remove ammonium salts and partial hydrolyzates.

[0034] In the present invention, the purity of the finished product of antioxidant 168 is greater than 99.3%, preferably 99.61%.

[0035] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] Preparation of crude antioxidant 168:

[0038] In a 2000mL four-necked bottle, add 500g of 2,4-di-tert-butylphenol, 100mL of xylene and 15g of triethylamine, mix, heat to 60°C, add phosphorus trichloride dropwise, slowly heat to 160°C after the addition is complete, carry out esterification reaction, and distill to dryness under reduced pressure to obtain a crude product of antioxidant 168.

[0039] Post-processing:

[0040] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 50°C and stirred to dissolve, then 50 g of water was added, and the temperature was maintained at 50°C for hydrolysis for 15 min to obtain a hydrolysis reaction liquid;

[0041] The obtained hydrolysis reaction liquid was allowed to stand for stratification, and the obtained xylene layer was successively subjected to reduced pressure distillation (temperature of 140°C, time of 50min), washed with 99.00% isopropanol solution, centrifuged (speed of rotation of 5000rpm, time of 8min) and dried (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 4.8ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 1.5ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 3.3ppm. The purity of the finished product of antioxidant 168 was 99.34%.

[0042] Example 2

[0043] The preparation of crude antioxidant 168 is the same as in Example 1.

[0044] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 60° C. and stirred to dissolve, then 50 g of water was added, and the temperature was maintained at 60° C. for hydrolysis for 15 min to obtain a hydrolysis reaction liquid;

[0045] The obtained hydrolysis reaction liquid was allowed to stand for stratification, and the obtained xylene layer was successively subjected to reduced pressure distillation (temperature of 140°C, time of 50min), washing with 99.00% isopropanol solution, centrifugation (speed of rotation of 5000rpm, time of 8min) and drying (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 4.3ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 1.5ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 2.8ppm. The purity of the finished product of antioxidant 168 was 99.38%.

[0046] Example 3

[0047] The preparation of crude antioxidant 168 is the same as in Example 1.

[0048] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 75°C and stirred to dissolve, then 50 g of water was added, the temperature was maintained at 75°C, and hydrolyzed for 15 min to obtain a hydrolysis reaction liquid;

[0049] The obtained hydrolysis reaction liquid was allowed to stand for stratification, and the obtained xylene layer was successively subjected to reduced pressure distillation (temperature of 140°C, time of 50min), washing with 99.00wt% isopropanol solution, centrifugation (speed of rotation of 5000rpm, time of 8min) and drying (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 3.6ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 1.3ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 2.3ppm. The purity of the finished product of antioxidant 168 was 99.42%.

[0050] Example 4

[0051] The preparation of crude antioxidant 168 is the same as in Example 1.

[0052] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 75°C and stirred to dissolve, then 150 g of water was added, the temperature was maintained at 75°C, and hydrolyzed for 15 min to obtain a hydrolysis reaction liquid;

[0053] The obtained hydrolysis reaction liquid was allowed to stand for stratification, and the obtained xylene layer was successively subjected to reduced pressure distillation (temperature of 140°C, time of 50min), washed with 99.00% isopropanol solution, centrifuged (speed of rotation of 5000rpm, time of 8min) and dried (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 3.0ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 1.1ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 1.9ppm. The purity of the finished product of antioxidant 168 was 99.47%.

[0054] Example 5

[0055] The preparation of crude antioxidant 168 is the same as in Example 1.

[0056] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 75°C and stirred to dissolve, then 300 g of water was added, the temperature was maintained at 75°C, and hydrolyzed for 15 min to obtain a hydrolysis reaction liquid;

[0057] The obtained hydrolysis reaction liquid was allowed to stand for stratification, and the obtained xylene layer was successively subjected to reduced pressure distillation (temperature of 140°C, time of 50min), washing with 99.00wt% isopropanol solution, centrifugation (speed of rotation of 5000rpm, time of 8min) and drying (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 2.8ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 1.0ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 1.8ppm. The purity of the finished product of antioxidant 168 was 99.52%.

[0058] Example 6

[0059] The preparation of crude antioxidant 168 is the same as in Example 1.

[0060] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 75°C and stirred to dissolve, then 300 g of water was added, the temperature was maintained at 75°C, and hydrolyzed for 30 min to obtain a hydrolysis reaction liquid;

[0061] The obtained hydrolysis reaction solution was allowed to stand for stratification, and the obtained xylene layer was successively subjected to vacuum distillation (temperature of 140°C, time of 50min), washed with 99.00% isopropanol solution, centrifuged (speed of rotation of 5000rpm, time of 8min) and dried (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. The total content of by-products was 1.7ppm as detected by HPLC. The content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 0.6ppm, and the content of (2,4-tert-butylphenyl) bis(di-tert-butylphenyl) phosphite was 1.1ppm. The purity of the finished product of antioxidant 168 was 99.57%.

[0062] Example 7

[0063] The preparation of crude antioxidant 168 is the same as in Example 1.

[0064] 500 g of crude antioxidant 168 and 500 g of xylene were placed in a 2000 mL four-necked flask, heated to 75°C and stirred to dissolve, then 300 g of water was added, the temperature was maintained at 75°C, and hydrolyzed for 60 min to obtain a hydrolysis reaction liquid;

[0065] The obtained hydrolysis reaction solution was allowed to stand for stratification, and the obtained xylene layer was successively subjected to reduced pressure distillation (temperature of 140°C, time of 50 min), washed with 99.00wt% isopropanol solution, centrifuged (speed of rotation of 5000rpm, time of 8 min) and dried (temperature of 85°C, time of 4 h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 0.2ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 0.1ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 0.1ppm. The purity of the finished product of antioxidant 168 was 99.61%.

[0066] Comparative Example 1

[0067] The preparation of crude antioxidant 168 is the same as in Example 1.

[0068] 500g of the crude product of antioxidant 168 and 500g of isopropanol (99.00%) were placed in a 2000mL four-necked flask, and the product was washed by reflux at a temperature of 30min, centrifuged (rotating speed of 5000rpm, time of 8min) and dried (temperature of 85°C, time of 4h) to obtain the finished product of antioxidant 168. According to HPLC detection, the total content of by-products was 178ppm, of which the content of tert-butylphenyl bis(2,4-di-tert-butylphenyl) phosphite was 52ppm, and the content of (2,4-tert-butylphenyl)bis(di-tert-butylphenyl) phosphite was 116ppm. The purity of the finished product of antioxidant 168 was 99.03%.

[0069] The present invention also conducts a hydrolysis resistance test on the products obtained in the embodiments and comparative examples. The test method is: weigh (10±0.1)g of the sample and put it into a 250mL iodine volume flask, add 50mL of distilled water, drop (2-3) drops of methyl orange indicator and put it into a (95±2)℃ blast constant temperature drying oven, keep it for 5 hours, observe the color of the aqueous solution in the iodine volume flask, if the color does not change, it is qualified, and if the solution color turns red, it is considered to be hydrolyzed. The test results are shown in Table 1.

[0070] Table 1 Statistics of hydrolysis resistance time of embodiments and comparative examples

[0071]

[0072]

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A post-treatment method for a crude antioxidant 168, characterized in that: The following steps are involved: The crude product of antioxidant 168 is dissolved in a benzene solvent, the obtained solution is mixed with water, and a hydrolysis reaction is carried out to obtain a hydrolysis reaction solution; the temperature of the hydrolysis reaction is 50-75° C., and the insulation time is 15-60 min; the mass ratio of the crude product of antioxidant 168 to water is 100:10-60; The hydrolysis reaction liquid is layered in sequence, and the obtained organic phase is concentrated and dried in sequence to obtain the finished product of antioxidant 168, and the purity of the finished product of antioxidant 168 is greater than 99.3%.

2. The post-processing method according to claim 1, characterized in that: The benzene solvent includes one or more of xylene, toluene, chlorobenzene and dichlorobenzene.

3. The post-processing method according to claim 1 or 2, characterized in that: The mass ratio of the crude antioxidant 168 to the benzene solvent is 1:0.9-1.

2.

4. The post-processing method according to claim 1, characterized in that: Before the drying, the concentrated product is washed and solid-liquid separated; the washing reagent includes an isopropanol solution.

5. The post-processing method according to claim 4, characterized in that: The mass concentration of the isopropanol solution is 75-99.99%.

6. The post-processing method according to claim 1, characterized in that: The drying temperature is 80-90° C. and the drying time is 3-5 hours.

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