Phosphite antioxidant and preparation process thereof

Abstract

The invention discloses a phosphite antioxidant and a preparation process thereof, and belongs to the field of chemical assistants. The phosphite antioxidant is prepared from the following raw materials: cardanol, phosphorus trichloride and modified branched chain alcohol, the molar ratio of the cardanol to the phosphorus trichloride to the modified branched chain alcohol is (2.4-2.6): (1-1.1): (0.7-0.9); the modified branched-chain alcohol is prepared by reacting epoxybutane with medium-chain amine according to a molar ratio of 1: 1 and then reacting the obtained intermediate product with chloropropane according to a molar ratio of 1: (1.05-1.1). The antioxidant has the effect of improving the processing stability while improving the thermal stability of the antioxidant to the material.

Description

Technical Field

[0001] This application relates to the field of chemical additives, and particularly to a phosphite antioxidant and its preparation process. Background Art

[0002] In recent years, with the rise of fields such as automobiles, electronics, and appliances, high molecular materials have become the mainstream materials due to their excellent processing performance and cost-effectiveness. However, high molecular materials, especially polyolefin materials, are prone to thermal oxidative degradation during processing and long-term use, resulting in a decline in mechanical properties, color change, and shortened service life. Therefore, antioxidants, as an indispensable additive in the processing of high molecular materials, have a continuously growing market demand. Among them, phosphite antioxidants occupy the core position in the antioxidant market due to their high efficiency in peroxide decomposition, synergistic cooperation with main antioxidants, and relatively low cost.

[0003] Phosphite antioxidants are phosphorus-containing organic compounds that effectively inhibit material oxidation by capturing free radicals and decomposing peroxides. Traditional phosphite antioxidants usually add raw materials such as nonylphenol and bisphenol A to synthesize phosphite antioxidants in order to enhance their heat and hydrolysis resistance stability. However, with the improvement of environmental protection requirements, the restricted use of nonylphenol, bisphenol A, etc. has become increasingly strict. Therefore, people have begun to use bio-based raw materials for substitution, such as synthesizing phosphite antioxidants from cardanol and phosphorus trichloride.

[0004] However, it has been found in actual use that although the phosphite antioxidant synthesized from cardanol can meet the requirements of thermal stability, it has deficiencies in processing stability. For example, for polyolefin materials added with this phosphite antioxidant, the melt index changes greatly after multiple extrusions, affecting processing stability. Summary of the Invention

[0005] In order to improve the thermal stability of the antioxidant to the material while improving the processing stability, this application provides a phosphite antioxidant and its preparation process.

[0006] In the first aspect, the phosphite antioxidant provided by this application adopts the following technical solution: A phosphite antioxidant is prepared from the following raw materials: cardanol, phosphorus trichloride, and modified branched-chain alcohol; The molar ratio of the cardanol, phosphorus trichloride, and modified branched-chain alcohol is (2.4 - 2.6):(1 - 1.1):(0.7 - 0.9); The modified branched-chain alcohol is obtained by reacting epoxy butane and medium-chain amine in a molar ratio of 1:1, and then reacting the obtained intermediate product with chloropropane in a molar ratio of 1:(1.05 - 1.1).

[0007] By adopting the above technical solution, on the basis of the synthesis of cardanol-based phosphite antioxidants, the modified branched-chain alcohol reacts with the remaining chlorine on the phosphorus of the phosphite to form a branched-chain structure of the antioxidant. When applied to polyolefin materials and polycarbonate materials, it can improve the thermal stability of polyolefin materials and polycarbonate materials, and at the same time improve the influence of the processing stability of polyolefin materials and polycarbonate materials. For example, the melt index of polyolefin materials and polycarbonate materials can still be well controlled after multiple extrusions.

[0008] Optionally, the medium-chain amine includes one or more of n-hexylamine, n-heptylamine, and n-octylamine.

[0009] By adopting the above technical solution, amines with appropriate carbon chain lengths are selected to stably bind the modified branched-chain alcohol within the structure of the phosphite, which helps to maintain the thermal stability of the material by the phosphite antioxidant.

[0010] Optionally, the medium-chain amine is n-hexylamine.

[0011] By adopting the above technical solution, n-hexylamine is selected to achieve a balance between maintaining the stability of the phosphite antioxidant and improving the processing stability of polyolefin materials and polycarbonate materials, and the comprehensive effect is better.

[0012] Optionally, the epoxy butane is 1,2-epoxybutane.

[0013] Optionally, the chloropropane is 1-chloropropane.

[0014] In the second aspect, a preparation process of a phosphite antioxidant provided by the present application adopts the following technical solution: A preparation process of a phosphite antioxidant includes the following steps: Mix epoxy butane and medium-chain amine for reaction to obtain an intermediate product, add chloropropane and a promoter to the intermediate product for reaction, and obtain a modified branched-chain alcohol after the reaction ends; Mix cardanol and a catalyst evenly, dropwise add phosphorus trichloride, heat the reaction after the dropping is completed, add the modified branched-chain alcohol in batches after reacting for a period of time, continue the reaction, then distill off the excess modified branched-chain alcohol, and add an acid-binding agent for neutralization to obtain the phosphite antioxidant.

[0015] By adopting the above technical solution, epoxy butane and medium-chain amine are connected by opening the epoxy group reaction, and at the same time an intermediate product containing one hydroxyl group and secondary amine is obtained. Under the action of a promoter, the intermediate product reacts with chloropropane through secondary amine to form an alcohol with a branched-chain structure, that is, a modified branched-chain alcohol. After cardanol reacts with phosphorus trichloride to a certain extent, a phosphite with one remaining chlorine is obtained, and then the modified branched-chain alcohol is incorporated to obtain a new type of phosphite antioxidant. While maintaining its own good stability, this antioxidant has good processing stability for a variety of materials.

[0016] Optionally, during the process of adding the modified branched-chain alcohol in batches, it is divided into three batches in total. The first batch of the modified branched-chain alcohol accounts for 20% - 30% of the total mass of the modified branched-chain alcohol, the second batch accounts for 50% - 60% of the total mass of the modified branched-chain alcohol, and the third batch accounts for 10% - 30% of the total mass of the modified branched-chain alcohol. The temperature when adding the first batch is 70 - 80°C, the temperature when adding the second batch is 90 - 100°C, and the temperature when adding the first batch is 70 - 80°C.

[0017] By adopting the above technical solution, adding the modified branched-chain alcohol in batches, controlling the addition amount and temperature of each batch of the modified branched-chain alcohol, controlling the reaction to proceed in an orderly manner, reducing the generation of by-products, and increasing the yield of the phosphite antioxidant.

[0018] Optionally, the temperature during the dropping process of phosphorus trichloride is 40 - 50°C. After the addition of phosphorus trichloride is completed, it is heated to 70 - 80°C and reacted for 1 - 1.5 h, then heated to 90 - 100°C and continued to react for 0.5 - 1 h, then heated to 120 - 130°C and continued to react for 1 - 1.5 h, and then cooled to 70 - 80°C, and the modified branched-chain alcohol is added in batches.

[0019] By adopting the above technical solution, controlling the reaction between cardanol and phosphorus trichloride to proceed in an orderly manner, reducing the generation of by-products, and increasing the yield of the phosphite antioxidant.

[0020] Optionally, the mass of the promoter is 1% - 2% of the mass of chloropropane; the promoter is potassium iodide.

[0021] By adopting the above technical solution, the promoter can catalyze the attack of chloropropane on the amino group of the intermediate product, realize the short-chain connection, and accelerate the reaction.

[0022] Optionally, the mass of the catalyst is 1% - 1.8% of the mass of cardanol; the catalyst is methyltrioctylammonium chloride.

[0023] By adopting the above technical solution, the catalyst can catalyze the reaction between phosphorus trichloride and cardanol and accelerate the reaction.

[0024] Optionally, the mass of the acid-binding agent is 2% - 2.5% of the mass of cardanol; the acid-binding agent is triethylamine.

[0025] By adopting the above technical solution, the acid-binding agent is used to neutralize the hydrogen chloride generated during the reaction.

[0026] Optionally, the distillation to remove the excessive modified branched-chain alcohol is carried out under a pressure of -90 to -99 kPa and a temperature of 155 to 160°C.

[0027] By adopting the above technical solution, it helps to quickly distill off the modified branched-chain alcohol.

[0028] In summary, the present application has the following beneficial effects: 1. Based on the synthesis of cardanol-based phosphite antioxidants, the modified branched-chain alcohol reacts with the remaining chlorine on the phosphorus of the phosphite to form a branched-chain structure for the antioxidant. When applied to polyolefin materials and polycarbonate materials, it can improve the thermal stability of polyolefin materials and polycarbonate materials, and at the same time improve the influence on the processing stability of polyolefin materials and polycarbonate materials. For example, the melt index of polyolefin materials and polycarbonate materials can still be well controlled after multiple extrusions.

[0029] 2. In the preparation process of the phosphite antioxidant of the present application, the modified branched-chain alcohol is added in batches, and the addition amount and temperature of each batch of modified branched-chain alcohol are controlled to control the reaction to proceed in an orderly manner, reduce the generation of by-products, and improve the yield of the phosphite antioxidant. Specific Embodiments

[0030] The following further details the present application.

[0031] Example 1 A preparation process of a phosphite antioxidant includes the following steps: Take epoxy butane and medium-chain amine in a molar ratio of 1:1. In this example, the medium-chain amine is specifically n-hexylamine. Stir and mix epoxy butane and n-hexylamine at 45 °C for 2 h to obtain an intermediate product.

[0032] The intermediate product reacts with chloropropane and a promoter at room temperature for 1 h. In this example, the promoter is specifically potassium iodide. The molar ratio of the intermediate product to chloropropane is 1:1.05, and the mass of the promoter is 1% of the mass of chloropropane. After the reaction is completed, acetone is added for washing, and the mass of acetone is 10% of the mass of the intermediate product. Then water is added for washing, and the mass of water is equal to the mass of the intermediate product. The organic layer insoluble in the water phase is separated and collected to obtain the modified branched-chain alcohol.

[0033] Take cardanol, phosphorus trichloride, and the modified branched-chain alcohol in a molar ratio of 2.4:1:0.7, and then take a catalyst. In this example, the catalyst is specifically methyltrioctylammonium chloride, and the mass of the catalyst is 1% of the mass of cardanol. Put cardanol and the catalyst into a reaction kettle and mix evenly, and add phosphorus trichloride dropwise at 40 °C. During the dropping process and the subsequent reaction process, start the tail gas system to absorb the hydrogen chloride gas generated by the reaction. After the dropping of phosphorus trichloride is completed in 1 h, heat the reaction.

[0034] Specifically, the heating reaction process is to first heat to 70 °C and react for 1.5 h, then raise the temperature to 90 °C and continue to react for 1 h, and then raise the temperature to 120 °C and continue to react for 1.5 h.

[0035] Then cool down to 70°C. After reacting for a period of time, add the modified branched-chain alcohol in batches. During the process of adding the modified branched-chain alcohol in batches, it is divided into three batches in total. The first batch of the modified branched-chain alcohol accounts for 20% of the total mass of the modified branched-chain alcohol. After reacting for 30 minutes, add the second batch. The second batch of the modified branched-chain alcohol accounts for 50% of the total mass of the modified branched-chain alcohol. After reacting for 30 minutes, add the third batch. The third batch of the modified branched-chain alcohol accounts for 30% of the total mass of the modified branched-chain alcohol. The temperature when adding the first batch is 70°C, the temperature when adding the second batch is 90°C, and the temperature when adding the first batch is 70°C. After adding the third batch of the modified branched-chain alcohol, continue to react for 1 hour.

[0036] Then distill off the excess modified branched-chain alcohol. The distillation process is carried out under a pressure of -90 to kPa and a temperature of 155°C. Finally, add an acid-binding agent for neutralization. The acid-binding agent is specifically triethylamine, and the mass of the acid-binding agent is 2% of the mass of cardanol, obtaining the phosphite antioxidant.

[0037] Example 2 A preparation process of a phosphite antioxidant, comprising the following steps: Take epoxy butane and medium-chain amine in a molar ratio of 1:1. In this example, the medium-chain amine is specifically n-hexylamine. Stir and mix epoxy butane and n-hexylamine at 45°C for 2 hours to obtain an intermediate product.

[0038] The intermediate product reacts with chloropropane and a promoter at room temperature for 1 hour. In this example, the promoter is specifically potassium iodide. The molar ratio of the intermediate product to chloropropane is 1:1.1, and the mass of the promoter is 2% of the mass of chloropropane. After the reaction is completed, add acetone for washing. The mass of acetone is 10% of the mass of the intermediate product, and then add water for washing. The mass of water is equal to the mass of the intermediate product. Separate and collect the organic layer that is insoluble in the aqueous phase to obtain the modified branched-chain alcohol.

[0039] Take cardanol, phosphorus trichloride and the modified branched-chain alcohol in a molar ratio of 2.6:1.1:0.9, and then take a catalyst. In this example, the catalyst is specifically methyltrioctylammonium chloride, and the mass of the catalyst is 1.8% of the mass of cardanol. Put cardanol and the catalyst into the reaction kettle and mix evenly. Dropwise add phosphorus trichloride at 50°C. During the dropping process and the subsequent reaction process, turn on the tail gas system to absorb the hydrogen chloride gas generated by the reaction. After the dropping of phosphorus trichloride is completed in 1 hour, carry out a heating reaction.

[0040] Specifically, the heating reaction process is as follows: First, heat to 80°C and react for 1 hour, then raise the temperature to 100°C and continue to react for 0.5 hour, and then raise the temperature to 130°C and continue to react for 1 hour.

[0041] Then cool down to 80°C. After reacting for a period of time, add the modified branched-chain alcohol in batches. During the process of adding the modified branched-chain alcohol in batches, it is divided into three batches in total. The first batch of the modified branched-chain alcohol accounts for 30% of the total mass of the modified branched-chain alcohol, the second batch accounts for 60% of the total mass of the modified branched-chain alcohol, and the third batch accounts for 10% of the total mass of the modified branched-chain alcohol. The temperature is 80°C when adding the first batch, 100°C when adding the second batch, and 80°C when adding the first batch.

[0042] Then distill off the excess modified branched-chain alcohol. The distillation process is carried out under a pressure of -99 kPa and a temperature of 160°C. Finally, add an acid-binding agent for neutralization. The acid-binding agent is specifically triethylamine, and the mass of the acid-binding agent is 2.5% of the mass of cardanol to obtain the phosphite antioxidant.

[0043] Example 3 A preparation process of a phosphite antioxidant, which is different from Example 1 in that the modified branched-chain alcohol is different.

[0044] Take epoxy butane and medium-chain amine in a molar ratio of 1:1.05. In this example, the medium-chain amine is specifically n-heptylamine. Stir and mix epoxy butane and n-heptylamine at 45°C for 2 h to obtain an intermediate product.

[0045] The intermediate product reacts with chloropropane and a promoter at room temperature for 1 h. In this example, the promoter is specifically potassium iodide. The molar ratio of the intermediate product to chloropropane is 1:1.05, and the mass of the promoter is 1% of the mass of chloropropane. After the reaction, add acetone for washing. The mass of acetone is 10% of the mass of the intermediate product, and then add water for washing. The mass of water is equal to the mass of the intermediate product. Separate and collect the organic layer that is insoluble in the aqueous phase to obtain the modified branched-chain alcohol.

[0046] Example 4 A preparation process of a phosphite antioxidant, which is different from Example 1 in that the modified branched-chain alcohol is different.

[0047] Take epoxy butane and medium-chain amine in a molar ratio of 1:1.05. In this example, the medium-chain amine is specifically n-octylamine. Stir and mix epoxy butane and n-octylamine at 45°C for 2 h to obtain an intermediate product.

[0048] The intermediate product reacts with chloropropane and a promoter at room temperature for 1 h. In this example, the promoter is specifically potassium iodide. The molar ratio of the intermediate product to chloropropane is 1:1.05, and the mass of the promoter is 1% of the mass of chloropropane. After the reaction, add acetone for washing. The mass of acetone is 10% of the mass of the intermediate product, and then add water for washing. The mass of water is equal to the mass of the intermediate product. Separate and collect the organic layer that is insoluble in the aqueous phase to obtain the modified branched-chain alcohol.

[0049] Example 5 A preparation process of a phosphite antioxidant, which is different from Example 1 in that the modified branched-chain alcohol is different.

[0050] Take epoxy butane and medium-chain amine in a molar ratio of 1:1.05. In this example, the medium-chain amine is specifically n-pentylamine. Stir and mix epoxy butane and n-pentylamine at 45 °C for 2 h to obtain an intermediate product.

[0051] The intermediate product reacts with chloropropane and a promoter at room temperature for 1 h. In this example, the promoter is specifically potassium iodide. The molar ratio of the intermediate product to chloropropane is 1:1.05, and the mass of the promoter is 1% of the mass of chloropropane. After the reaction, acetone is added for washing, and the mass of acetone is 10% of the mass of the intermediate product. Then water is added for washing, and the mass of water is equal to the mass of the intermediate product. The organic layer insoluble in the aqueous phase is separated and collected to obtain the modified branched-chain alcohol.

[0052] Comparative Example 1 A preparation process of a phosphite antioxidant, comprising the following steps: Take cardanol and phosphorus trichloride in a molar ratio of 3.1:1, and then take a catalyst. In this example, the catalyst is specifically methyltrioctylammonium chloride, and the mass of the catalyst is 1% of the mass of cardanol. Put cardanol and the catalyst into a reaction kettle and mix evenly, and add phosphorus trichloride dropwise at 40 °C. During the dropping process and the subsequent reaction process, turn on the tail gas system to absorb the hydrogen chloride gas generated by the reaction. After the dropping of phosphorus trichloride is completed in 1 h, heat the reaction.

[0053] Specifically, the heating reaction process is to first heat to 70 °C and react for 1.5 h, then raise the temperature to 90 °C and continue to react for 1 h, and then raise the temperature to 120 °C and continue to react for 2.5 h.

[0054] Finally, a deacidifying agent is added for neutralization. The deacidifying agent is specifically triethylamine, and the mass of the deacidifying agent is 2% of the mass of cardanol to obtain the phosphite antioxidant.

[0055] Comparative Example 2 A preparation process of a phosphite antioxidant, comprising the following steps: Take cardanol, phosphorus trichloride and isooctanol in a molar ratio of 2.4:1:0.7, and then take a catalyst. In this example, the catalyst is specifically methyltrioctylammonium chloride, and the mass of the catalyst is 1% of the mass of cardanol. Put cardanol and the catalyst into a reaction kettle and mix evenly, and add phosphorus trichloride dropwise at 40 °C. During the dropping process and the subsequent reaction process, turn on the tail gas system to absorb the hydrogen chloride gas generated by the reaction. After the dropping of phosphorus trichloride is completed in 1 h, heat the reaction.

[0056] Specifically, in the heating reaction process, it is first heated to 70°C and then reacted for 1.5 h, then heated to 90°C and reacted for another 1 h, and then heated to 120°C and reacted for 1.5 h.

[0057] Then it is cooled to 70°C. After reacting for a period of time, isooctanol is added in batches. During the process of adding isooctanol in batches, it is divided into three batches in total. The first batch of isooctanol accounts for 20% of the total mass of isooctanol. After reacting for 30 min, the second batch is added. The second batch of isooctanol accounts for 50% of the total mass of isooctanol. After reacting for 30 min, the third batch is added. The third batch of isooctanol accounts for 30% of the total mass of isooctanol. The temperature when the first batch is added is 70°C, the temperature when the second batch is added is 90°C, and the temperature when the first batch is added is 70°C. After the third batch of isooctanol is added, the reaction continues for 1 h.

[0058] Then the excess isooctanol is removed by distillation. The distillation process is carried out under a pressure of -90 to kPa and a temperature of 155°C. Finally, an acid-binding agent is added for neutralization. The acid-binding agent is specifically triethylamine, and the mass of the acid-binding agent is 2% of the mass of cardanol, obtaining a phosphite antioxidant.

[0059] Comparative Example 3 A preparation process of a phosphite antioxidant includes the following steps: Take epoxybutane and medium-chain amine in a molar ratio of 1:1.05. In this example, the medium-chain amine is specifically n-hexylamine. Epoxybutane and n-hexylamine are stirred and mixed at 45°C for 2 h to obtain an intermediate product, and the intermediate product is used as the modified branched-chain alcohol in this comparative example.

[0060] Take cardanol, phosphorus trichloride and the modified branched-chain alcohol in a molar ratio of 2.4:1:0.7, and then take a catalyst. In this example, the catalyst is specifically methyltrioctylammonium chloride, and the mass of the catalyst is 1% of the mass of cardanol. Cardanol and the catalyst are put into a reaction kettle and mixed evenly, and phosphorus trichloride is added dropwise at 40°C. During the dropping process and the subsequent reaction process, the tail gas system is turned on to absorb the hydrogen chloride gas generated by the reaction. After phosphorus trichloride is added dropwise for 1 h, a heating reaction is carried out.

[0061] Specifically, in the heating reaction process, it is first heated to 70°C and then reacted for 1.5 h, then heated to 90°C and reacted for another 1 h, and then heated to 120°C and reacted for 1.5 h.

[0062] Then cool down to 70°C. After reacting for a period of time, add the modified branched-chain alcohol in batches. During the process of adding the modified branched-chain alcohol in batches, it is divided into three batches in total. The first batch of the modified branched-chain alcohol accounts for 20% of the total mass of the modified branched-chain alcohol. After reacting for 30 minutes, add the second batch. The second batch of the modified branched-chain alcohol accounts for 50% of the total mass of the modified branched-chain alcohol. After reacting for 30 minutes, add the third batch. The third batch of the modified branched-chain alcohol accounts for 30% of the total mass of the modified branched-chain alcohol. The temperature when adding the first batch is 70°C, the temperature when adding the second batch is 90°C, and the temperature when adding the first batch is 70°C. Continue to react for 1 hour after adding the third batch of the modified branched-chain alcohol.

[0063] Then distill off the excess modified branched-chain alcohol. The distillation process is carried out under a pressure of -90 to kPa and a temperature of 155°C. Finally, add an acid-binding agent for neutralization. The acid-binding agent is specifically triethylamine, and the mass of the acid-binding agent is 2% of the mass of cardanol to obtain the phosphite antioxidant.

[0064] Experimental tests Take resins for experiments. The resins include polypropylene resin and polycarbonate. The polypropylene resin is the polypropylene resin without additives from Shanghai Petrochemical Company, and the polycarbonate resin is the polycarbonate resin without additives from Sinopec Company.

[0065] Thermal aging experiment: Take resins, divide them into an experimental group and a blank group. The resins in the experimental group are mixed with phenolic antioxidant 1010 and the phosphite antioxidants of Examples 1-5 and Comparative Examples 1-3. The mixing amount of antioxidant 1010 is 0.1 wt%, and the mixing amount of the phosphite antioxidant is 0.1 wt%. The resins in the blank group are mixed with phenolic antioxidant 1010, and the mixing amount of antioxidant 1010 is 0.1 wt%. Put the resins into a twin-screw extruder, extrude and cast to form specimen thin slices, and place them in an oven at 150°C and 75% RH for thermal aging, and record the thermal aging time when the appearance of the specimen thin slices is damaged.

[0066] Processing stability experiment: Take resins, divide them into an experimental group and a blank group. The resins in the experimental group are mixed with phenolic antioxidant 1010 and the phosphite antioxidants of Examples 1-5 and Comparative Examples 1-3. The mixing amount of antioxidant 1010 is 0.1 wt%, and the mixing amount of the phosphite antioxidant is 0.1 wt%. The resins in the blank group are mixed with phenolic antioxidant 1010, and the mixing amount of antioxidant 1010 is 0.1 wt%. Put the resins into a twin-screw extruder, extrude and granulate, and carry out extrusion five times in a cycle. Use a melt indexer to test the melt index (MFR) after the first extrusion and the fifth extrusion. The test conditions for the melt index of polypropylene resin particles are 230°C and a load of 2.16 kg, and the test conditions for the melt index of polycarbonate resin particles are 300°C and a load of 1.2 kg.

[0067] The above experimental results are shown in Table 1 and Table 2.

[0068] Table 1 Table 2 Combining Table 1 and Table 2, it can be seen that compared with the blank group, the materials added with the phosphite antioxidants of Examples 1-5 have significantly improved thermal aging ability and processing stability, and the function of the antioxidant is fully exerted.

[0069] Moreover, compared with Comparative Examples 1-3, the application of the phosphite antioxidant of Example 1 to the material has significantly improved thermal aging ability and processing stability, indicating that the synthesized phosphite antioxidant with the modified branched-chain alcohol and cardanol has better comprehensive antioxidant performance than the traditional cardanol-based phosphite antioxidant, and also indicating that the modified branched-chain alcohol of the present application is superior to isooctanol as a raw material. At the same time, the introduction of chloropropane also significantly improves the function of the modified branched-chain alcohol.

[0070] Compared with Examples 3-5, the application of the phosphite antioxidant of Example 1 to the material has significantly improved thermal aging ability and processing stability, and the comprehensive effect is better, indicating that the use of n-hexylamine as the middle-chain amine for synthesizing the modified branched-chain alcohol has the best effect.

[0071] This specific embodiment is only an interpretation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this specific embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A phosphite antioxidant, characterized in that: It is prepared from the following raw materials: cardanol, phosphorus trichloride, and modified branched-chain alcohol; The molar ratio of the cardanol, phosphorus trichloride, and modified branched-chain alcohol is (2.4 - 2.6):(1 - 1.1):(0.7 - 0.9); The modified branched-chain alcohol is obtained by reacting epoxy butane and medium-chain amine in a molar ratio of 1:1, and then reacting the obtained intermediate product with chloropropane in a molar ratio of 1:(1.05 - 1.1).

2. The phosphite antioxidant according to claim 1, wherein: The medium-chain amine includes one or more of n-hexylamine, n-heptylamine, and n-octylamine.

3. The phosphite antioxidant according to claim 1, wherein: The medium-chain amine is n-hexylamine.

4. A preparation process of the phosphite antioxidant according to any one of claims 1-3, characterized in that: It includes the following steps: Mix epoxy butane and medium-chain amine for reaction to obtain an intermediate product, add chloropropane and a promoter to the intermediate product for reaction, and obtain the modified branched-chain alcohol after the reaction ends; Mix cardanol and a catalyst evenly, dropwise add phosphorus trichloride, heat for reaction after the addition is completed, add the modified branched-chain alcohol in batches after reacting for a period of time, continue the reaction, then distill off the excessive modified branched-chain alcohol, and add an acid-binding agent for neutralization to obtain a phosphite antioxidant.

5. The preparation process of a phosphite antioxidant according to claim 4, characterized in that: During the process of adding the modified branched-chain alcohol in batches, it is divided into three batches in total. The first batch of the modified branched-chain alcohol accounts for 20% - 30% of the total mass of the modified branched-chain alcohol, the second batch accounts for 50% - 60% of the total mass of the modified branched-chain alcohol, and the third batch accounts for 10% - 30% of the total mass of the modified branched-chain alcohol. The temperature when adding the first batch is 70 - 80°C, the temperature when adding the second batch is 90 - 100°C, and the temperature when adding the first batch is 70 - 80°C.

6. The preparation process of a phosphite antioxidant according to claim 4, characterized in that: The temperature during the dropwise addition of phosphorus trichloride is 40 - 50°C. After the addition of phosphorus trichloride is completed, heat to 70 - 80°C and react for 1 - 1.5 h, then raise the temperature to 90 - 100°C and continue the reaction for 0.5 - 1 h, then raise the temperature to 120 - 130°C and continue the reaction for 1 - 1.5 h, and then cool down to 70 - 80°C, and add the modified branched-chain alcohol in batches.

7. The preparation process of a phosphite antioxidant according to claim 4, characterized in that: The mass of the promoter is 1% - 2% of the mass of chloropropane; the promoter is potassium iodide.

8. The preparation process of a phosphite antioxidant according to claim 4, characterized in that: The mass of the catalyst is 1% - 1.8% of the mass of cardanol; the catalyst is methyltrioctylammonium chloride.

9. The preparation process of a phosphite antioxidant according to claim 4, characterized in that: The mass of the acid-binding agent is 2% - 2.5% of the mass of cardanol; the acid-binding agent is triethylamine.

10. The preparation process of a phosphite antioxidant according to claim 4, characterized in that: The distillation to remove the excessive modified branched-chain alcohol is carried out under a pressure of -90~-99 kPa and a temperature of 155~160°C.

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