CN101250200A - Synthetic method of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite - Google Patents

Abstract

The invention discloses a synthesis method of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite. The present invention comprises following two steps: 1. the synthesis of dichloropentaerythritol diphosphite: take xylene as solvent, add pentaerythritol and catalyzer, pass into nitrogen, start stirring, dropwise add phosphorus trichloride, the hydrogen chloride gas of generation Absorb with sodium hydroxide solution; after the reaction product is purified, the xylene solution of dichloropentaerythritol diphosphite is obtained; 2. Synthesis of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite. Add 2,4-di-tert-butylphenol to the product reacted in step (1), pass in nitrogen gas and stir, the hydrogen chloride gas generated by the reaction is absorbed with sodium hydroxide solution, and the reaction product is purified to obtain the product. The invention uses 2,4-di-tert-butylphenol, pentaerythritol and phosphorus trichloride as main raw materials, has low price, easy reaction and high reaction yield.

Description

The synthetic method of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite

technical field

The present invention relates to a synthesis method of an antioxidant, in particular to a new synthesis method of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

Background technique

The structural formula of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphites is:

Because in this molecule, there are free radical scavenger pentaerythritol group and hydroperoxide decomposing agent phosphite group, the free radical scavenger and hydroperoxide decomposing agent are compounded in one molecule, therefore, this compound It is a molecular compound antioxidant and heat stabilizer. It is used together with hindered phenolic or hindered amine stabilizers, both of which can produce synergistic effects. The trade name is antioxidant 626. It is a new type of high-performance phosphorus-containing antioxidant with excellent prospects.

Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite is widely used as auxiliary antioxidant in PE, PP, PVC, ABS, PC, polyester, etc. Approved by the US FDA and Germany for use in food packaging materials. This product can improve color stability, light stability, processing stability and thermal stability; when used in PET, it can passivate the catalyst remaining in the polymer, improve color stability, and remove gel phenomenon, which is very beneficial to recycled PET Good stabilizing effect; compounded with phenolic antioxidants, UV absorbers and hindered amine light stabilizers, it can form a system with the best processability, long-term aging resistance, UV stability and economy. The main foreign manufacturer is General Electric Company; domestic Tianjin Institute of Synthetic Materials Industry and Beijing Research Institute of Chemical Industry are conducting research, and the main domestic manufacturer is Ningbo Jinhai Yabao Chemical Co., Ltd.

About two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite synthetic methods, the current published literature reports mainly contain: (1) Antioxidant 168 and pentaerythritol are esterified under high temperature and high vacuum. The exchange reaction can generate antioxidant 626, and at the same time by-produce 2,4-di-tert-butylphenol. By-product can be used as the production raw material recycling of antioxidant 168; (2) adopt triphenyl phosphite as raw material, mix with 2,4-di-tert-butylphenol, pentaerythritol and carry out transesterification reaction, by-product is phenol; ( 3) Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite was synthesized using phosphorus trichloride, pentaerythritol and 2,4-di-tert-butylphenol as main raw materials. Among them, in the first production method, the process is simple, the by-products can be recycled, and the yield is relatively high. However, the reaction conditions are harsh and the cost of raw materials is high; in the second method, the by-product phenol can be recycled. However, the trace amount of phenol in the product is difficult to remove, and the product is prone to yellowing, which limits its application in the fields of food and medicine; the third method, the specific process route, has not been publicly reported.

Contents of the invention

The object of the present invention is to overcome the shortcoming that prior art exists, a kind of synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite is provided, with phosphorus trichloride, pentaerythritol and 2,4- Di-tert-butylphenol is the main raw material, the price is low, the reaction is easy to carry out, and the yield of the reaction is relatively high.

To achieve the above object, the present invention has taken the following technical solutions:

Principle of the present invention is as follows:

The synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite comprises the following steps:

(1) Synthesis of dichloropentaerythritol diphosphite;

In a three-necked flask equipped with a stirrer, a condenser, a thermometer, and a receiver, add metered xylene solvent, pentaerythritol, and a catalyst, feed nitrogen, and start stirring at a stirring speed of 300 to 700 rpm. Add phosphorus trichloride dropwise within 1 minute, react at 30-90°C for 1-5 hours, and absorb the generated hydrogen chloride gas with sodium hydroxide solution; Pressure distills unreacted phosphorus trichloride, removes unreacted pentaerythritol by filtration, obtains the xylene solution of dichloropentaerythritol diphosphite;

Phosphorus trichloride: the mol ratio of pentaerythritol is 2～2.40: 1;

By weight, the consumption of catalyst is 1-4% of pentaerythritol;

Described catalyst is: octadecylamine, methyl ammonium chloride, triethylamine;

(2) Synthesis of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphites:

In the reaction product of step (1), add 2,4-di-tert-butylphenol and stir at a stirring speed of 300 to 700 rpm; react at a temperature of 85 to 140°C for 1 to 4 hours, and use Sodium hydroxide solution absorption; under the condition of temperature of 160°C and pressure of -0.03 ~ 0.08Mpa, the solvent xylene is distilled off under reduced pressure; isopropanol is added, and the product is crystallized by stirring. The white solid powder obtained after suction filtration is the product; the molar ratio of the 2,4-di-tert-butylphenol to the intermediate dichloropentaerythritol diphosphite is 2-2.20:1.

The process of the invention uses phosphorus trichloride, pentaerythritol and 2,4-di-tert-butylphenol as main raw materials, and the price is low. Reaction is divided into two steps and carries out, and the first step is solvent with xylene, phosphorus trichloride, pentaerythritol generate dichloropentaerythritol diphosphite; Second step is solvent with xylene, dichloropentaerythritol diphosphite and 2,4-di-tert-butylphenol reacts to generate bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; the reaction is easy to carry out.

Description of drawings

Fig. 1 is the infrared spectrogram of the product that embodiment 3 makes.

Figure 2 is the ¹ HNMR chart of the product prepared in Example 3.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited to the scope involved in the examples.

Example 1

The synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite comprises the following steps:

(1) Synthesis of dichloropentaerythritol diphosphite;

In the there-necked flask equipped with stirrer, condenser, thermometer, receiver, add 250ml xylene solvent, 0.2mol pentaerythritol 27.2g and 0.27g catalyst, feed nitrogen, start stirring, stirring speed is 300 rpm, in Add 55g of 0.4mol phosphorus trichloride dropwise within 30 minutes, react at 30°C for 4h, and absorb the generated hydrogen chloride gas with 40g of sodium hydroxide solution; depressurize at a temperature of 90°C and a pressure of -0.001Mpa Unreacted phosphorus trichloride was distilled off, and 0.2 g of unreacted pentaerythritol was removed by filtration to obtain a xylene solution of dichloropentaerythritol diphosphite;

The mol ratio of phosphorus trichloride and pentaerythritol is 2.0: 1;

By weight, the consumption of the catalyst is 1% of pentaerythritol; the catalyst is octadecylamine;

(2) Synthesis of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphites:

Add 82.5 g of 0.4 mol 2,4-di-tert-butylphenol to the reaction product of step (1), stir at a stirring speed of 300 rpm; react at 85°C for 4 h, and oxidize the hydrogen chloride gas generated with 20 g of hydrogen Sodium solution absorption; under the conditions of temperature 160°C and pressure -0.03Mpa, the solvent xylene was distilled off under reduced pressure; 170ml of isopropanol was added, and the product was crystallized by stirring. The white solid powder obtained after suction filtration is the product; the molar ratio of 2,4-di-tert-butylphenol to pentaerythritol is 2.0:1.

Example 2

The synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite comprises the following steps:

1. Synthesis of dichloropentaerythritol diphosphite;

In a three-necked flask equipped with a stirrer, a condenser, a thermometer, and a receiver, add 250ml of xylene solvent, 27.2g of 0.2mol pentaerythritol and 0.55g of catalyst methylammonium chloride, feed nitrogen, start stirring, and the stirring speed is 500 RPM, drop 60.5g of 0.44mol phosphorus trichloride within 40 minutes, react at 60°C for 3h, and absorb the hydrogen chloride gas generated with 40g of sodium hydroxide solution; at a temperature of 90°C and a pressure of -0.004 Under the condition of Mpa, unreacted phosphorus trichloride is distilled off under reduced pressure, filters out unreacted pentaerythritol 0.1g, obtains the xylene solution of dichloropentaerythritol diphosphite; The mol ratio of phosphorus trichloride and pentaerythritol is: 2.20: 1; By weight, the consumption of catalyzer is 2% of pentaerythritol; Described catalyzer is methyl ammonium chloride;

2. Synthesis of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite:

In the reaction product of step (1), add 86.61 g of 0.42 mol of 2,4-di-tert-butylphenol, stir at a stirring speed of 500 rpm; Sodium hydroxide solution absorption; under the condition of temperature of 160°C and pressure of -0.06Mpa, the solvent xylene was distilled off under reduced pressure; 180ml of isopropanol was added, and the product was crystallized by stirring. The white solid powder obtained after suction filtration is the product; the molar ratio of 2,4-di-tert-butylphenol to pentaerythritol is 2.10:1.

Example 3

The synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite comprises the following steps:

1. Synthesis of dichloropentaerythritol diphosphite;

In a three-necked flask equipped with a stirrer, a condenser, a thermometer, and a receiver, add 230ml of xylene solvent, 27.2g of 0.2mol pentaerythritol and 0.9g of catalyst triethylamine, feed nitrogen, start stirring, and the stirring speed is 700 rpm In 50 minutes, 66g of 0.48mol phosphorus trichloride was added dropwise, reacted at 90°C for 1h, and the generated hydrogen chloride gas was absorbed with 40g of sodium hydroxide solution; under the condition of temperature of 90°C and pressure of -0.006Mpa Under reduced pressure, unreacted phosphorus trichloride was distilled off, and 0.2 g of unreacted pentaerythritol was removed by filtration to obtain a xylene solution of dichloropentaerythritol diphosphite; the molar ratio of phosphorus trichloride to pentaerythritol was 2.4:1 ; By weight, the consumption of catalyzer is 3% of pentaerythritol; Described catalyzer is octadecylamine; 2, two (2, the synthesis of 4-di-tert-butylphenyl) pentaerythritol diphosphite:

In the reaction product of step (1), add 90.74 g of 0.44 mol of 2,4-di-tert-butylphenol, stir, and the stirring speed is 700 rpm; react for 1.0 h at a temperature of 140° C. 20g of sodium hydroxide solution for absorption; under the condition of temperature of 160°C and pressure of -0.06Mpa, the solvent xylene was distilled off under reduced pressure; 190ml of isopropanol was added, and the product was crystallized by stirring. The white solid powder obtained after suction filtration is the product; the molar ratio of 2,4-di-tert-butylphenol to pentaerythritol is 2.20:1.

Example 4

The synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite comprises the following steps:

(1) Synthesis of dichloropentaerythritol diphosphite;

In the there-necked flask equipped with stirrer, condenser, thermometer, receiver, add 240ml xylene solvent, 0.2mol pentaerythritol 27.2g and 1.1g catalyst, feed nitrogen, start stirring, stirring speed is 500 rpm, in Add 58g of 0.4mol phosphorus trichloride dropwise within 30 minutes, react at 30°C for 5h, and absorb the generated hydrogen chloride gas with 40g of sodium hydroxide solution; depressurize at a temperature of 90°C and a pressure of -0.001Mpa Distill out unreacted phosphorus trichloride, remove unreacted pentaerythritol 0.3g by filtration, obtain the xylene solution of dichloropentaerythritol diphosphite; The mol ratio of phosphorus trichloride and pentaerythritol is 2.10: 1; Calculated, the consumption of catalyzer is 4% of pentaerythritol; Described catalyzer is octadecylamine;

(2) Synthesis of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphites:

In the reaction product of step (1), add 88.67 g of 0.43 mol of 2,4-di-tert-butylphenol, stir at a stirring speed of 300 rpm; react at a temperature of 85° C. for 4 h, and use 20 g of hydrogen chloride gas to Sodium hydroxide solution absorption; under the condition of temperature of 160°C and pressure of -0.03Mpa, the solvent xylene was distilled off under reduced pressure; 200ml of isopropanol was added, and the product was crystallized by stirring. The white solid powder obtained after suction filtration is the product; the molar ratio of 2,4-di-tert-butylphenol to pentaerythritol is 2.15:1.

product analysis

Carry out product analysis with the product that embodiment 3 makes. The products obtained in other examples are the same.

1. Product purification

The reaction product contains some impurities, mainly unreacted products, which are purified by a suitable process to obtain pure bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

2. Elemental analysis

Two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite products were analyzed for elements, and the results are shown in Table 1. The content of C, H, and P elements in the sample is close to the theoretical value of the C, H, and P element content of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, indicating that the obtained sample has high purity.

Table 1: Product elemental analysis results

Measurements C H P theoretical value 67.21 11.20 8.47 Product measured value 67.43 11.32 8.10

3. Infrared spectral analysis

The infrared spectrum of the product is shown in Figure 1: 1227 is the vibration absorption peak of PO-benzene ring (1240~1190); 1016 is the vibration absorption peak of POC bond (1050~1030); 2957 is -CH ₃ , -CH ₂ 1362 is the vibration peak of tert-butyl group; 1495 is the vibration absorption peak of the benzene ring skeleton; it is consistent with the infrared characteristic absorption peak of the main group in the target product structure.

4. ¹ HNMR analysis

The ¹ HNMR analysis of the product is shown in Figure 2: the calculated chemical shift value of the hydrogen proton in the product is basically consistent with the measured value, and the number of hydrogen is the same as that of the target product, so the result of the product is completely the same as that of the target product.

Table 2: Calculated and measured chemical shift values of hydrogen protons in the product, peak shape, and assignment of hydrogen protons

Conclusion: The product obtained from the reaction is bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite. The process of the present invention takes phosphorus trichloride, pentaerythritol and 2,4-di-tert-butylphenol as main raw materials, and has a wide range of sources. Compared with the raw material antioxidant 168 and pentaerythritol and the second process in the traditional first process The raw materials of triphenyl phosphite, 2,4-di-tert-butylphenol and pentaerythritol are cheap. Reaction is divided into two steps and carries out, and the first step is solvent with xylene, phosphorus trichloride, pentaerythritol generate dichloropentaerythritol diphosphite; Second step is solvent with xylene, dichloropentaerythritol diphosphite and 2,4-di-tert-butylphenol reacts to generate bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; the reaction is easy to carry out.

Claims (7)

1. the synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, is characterized in that comprising the following steps: (1) Synthesis of dichloropentaerythritol diphosphite; Mix xylene solvent, pentaerythritol and catalyst, feed nitrogen, start stirring at a stirring speed of 300-700 rpm, add phosphorus trichloride dropwise within 30-50 minutes, and react at a temperature of 30-90°C for 1 ~5h, the generated hydrogen chloride gas is absorbed with sodium hydroxide solution; under the condition of temperature 85~110℃ and pressure -0.001~0.006Mpa, the unreacted phosphorus trichloride is distilled off under reduced pressure, and the unreacted phosphorus trichloride is removed by filtration. Pentaerythritol, obtain the xylene solution of dichloropentaerythritol diphosphite; The solvent is xylene, and the molar ratio of phosphorus trichloride to pentaerythritol is 2 to 2.40:1; On a weight basis, the catalyst is used in an amount of 1 to 4% of pentaerythritol; Described catalyst is: octadecylamine, methyl ammonium chloride or triethylamine; (2) Synthesis of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphites: In the reaction product of step (1), add 2,4-di-tert-butylphenol, feed nitrogen, and start stirring at a stirring speed of 300 to 700 rpm; react at a temperature of 85 to 140°C for 1 to 4 hours, The generated hydrogen chloride gas is absorbed with sodium hydroxide solution; the solvent xylene is distilled off under reduced pressure at a temperature of 150-165°C and a pressure of -0.03-0.08Mpa; an appropriate amount of isopropanol is added, and the product is crystallized by stirring; The white solid powder obtained after filtration is the product; the molar ratio of 2,4-di-tert-butylphenol to pentaerythritol is 2-2.20:1. 2. the new synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite according to claim 1, it is characterized in that the consumption of the catalyst in step (1) is 2～3 of pentaerythritol %. 3. the new synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite according to claim 1, is characterized in that the reaction times of step (1) is 2～4h. 4. The novel synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite according to claim 1, characterized in that the reaction temperature of step (1) is 30～60°C. 5. The novel synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite according to claim 1, characterized in that the reaction temperature of step (2) is 90～110°C. 6. the new synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite according to claim 1, is characterized in that the reaction time of step (2) is 2～4h. 7. the new synthetic method of two (2,4-di-tert-butylphenyl) pentaerythritol diphosphite according to claim 1, is characterized in that 2 in step (2), 4-di-tert-butylphenol The molar ratio to the intermediate dichloropentaerythritol diphosphite is 2-2.15:1.

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