Synthesis process of antioxidant 1135

Abstract

The invention relates to the technical field of antioxidants, and particularly discloses a synthesis process of an antioxidant 1135, which comprises the following steps: (1) adding 3, 5-methyl ester, a catalyst and a catalytic auxiliary agent into a reaction container, filling nitrogen for replacement, heating, starting stirring, keeping the temperature, and adding isooctanol for reaction; (2) after the reaction in the step (1) is finished, distilling to remove unreacted isooctanol, cooling, adsorbing by using an adsorption filter aid, and filtering to obtain the antioxidant 1135; the catalytic auxiliary agent in the operation is a composition of diatomite and porous alumina according to a weight ratio of (3-8): 1. When the synthesis process of the antioxidant 1135 is applied, not only is a relatively high catalytic reaction progress achieved, but also relatively high product yield and product purity can be shown.

Description

Technical Field

[0001] The present application relates to the technical field of antioxidants, and more specifically, to a synthesis process of antioxidant 1135. Background Art

[0002] Antioxidants are indispensable additives in the production and processing of polymers. Without antioxidants, polymers will undergo rapid oxidative degradation during processing and use. Antioxidant 1135, also known as 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, is a liquid hindered phenol antioxidant with good performance. It is widely used in various polymers, especially in the antioxidant of polyurethane and its polymerized polyols in the automotive industry and in lubricating oil antioxidants.

[0003] There are two commonly used methods for synthesizing antioxidant 1135. One is to use 3,5-dimethyl ester and isopropanol for ester exchange reaction, and the other is to use 2,6-di-tert-butylphenol and acrylate for reaction without using 3,5-dimethyl ester as an intermediate. For example, the invention patent with authorization announcement number CN104447333B discloses a production method of liquid hindered phenol antioxidant 1135, comprising the following steps: 1) adding a certain amount of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid methyl ester ( 3,5-methyl ester), isooctyl alcohol and catalyst are put into the reactor, replaced with nitrogen, the temperature is controlled between 140 and 170°C, the vacuum degree is -0.04 to -0.08MPa, the methanol generated during the reaction is extracted, and the reaction is carried out for 4-8h; 2) the temperature is raised to 175 to 180°C, the vacuum degree is controlled below -0.096MPa, distilled for 90 to 120min, cooled to 80 to 90°C, an appropriate amount of organic acid is added to the reactor to neutralize the residual catalyst, filtered, and the filtrate is taken as the target product. Among them, in step 1), the reaction process is preferably to first heat up to 140 to 150°C, adjust the vacuum to -0.04 to -0.05MPa, react for 1 to 3h, continue to heat up to 160 to 170°C, adjust the vacuum degree to -0.07 to -0.08MPa, and react for 3-5h.

[0004] With respect to the above-mentioned related technologies, the inventors believe that, although a higher product yield and product purity can be achieved in the production of the above-mentioned antioxidant 1135, it can be seen that the catalytic reaction process is relatively long, resulting in a longer overall process time. If the catalytic reaction process is forcibly increased, it will have an adverse effect on the product yield and product purity.

[0005] Therefore, it is urgent to propose a solution to solve the above technical problems. Summary of the invention

[0006] In order to improve the catalytic reaction process during the production of antioxidant 1135 and obtain excellent product yield and product purity, the present application provides a synthesis process of antioxidant 1135.

[0007] The present application provides a synthesis process of antioxidant 1135, which adopts the following technical scheme: A synthesis process of antioxidant 1135 comprises the following steps: (1) adding 3,5-methyl ester, a catalyst and a catalyst auxiliary agent into a reaction vessel, replacing the atmosphere with nitrogen, heating and stirring, and then adding isooctyl alcohol to react while maintaining the temperature; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation, and after cooling, adsorption is performed using an adsorption filter aid, and antioxidant 1135 is obtained after filtration; The catalyst auxiliary agent in the above operation is a composition of diatomaceous earth and porous alumina in a weight ratio of (3-8):1.

[0008] By adopting the above technical scheme, diatomaceous earth has a special porous structure, a large number of silanol groups on the surface, and high thermal stability and chemical stability; porous alumina has a pore structure with abundant micropores and large specific surface area, and good thermal stability; and when diatomaceous earth and porous alumina are used as catalytic auxiliary agents in a specific weight ratio, the catalyst forms a multi-level load on the diatomaceous earth and porous alumina, and the overall activity, selectivity and stability of the catalyst are significantly improved, thereby significantly shortening the entire catalytic reaction process; at the same time, the synergistic combination of diatomaceous earth and porous alumina can also ensure the orderly progress of 3,5-methyl ester and isooctyl alcohol, play a regulatory role in the high catalytic process, and is conducive to obtaining excellent product yield and product purity. Moreover, in the operation of the entire synthesis process of antioxidant 1135, the mixture of 3,5-methyl ester, catalyst and catalytic auxiliary agent is first heated to a high temperature, and then isooctanol is added to the mixture while being kept warm. The previous heating promotes the full combination of the catalyst and the catalytic auxiliary agent and brings about a certain activation effect. Therefore, when isooctanol is subsequently introduced into the reaction, a higher catalytic reaction process can be obtained, thereby ensuring that the obtained antioxidant 1135 has excellent product yield and product purity.

[0009] Preferably, the weight ratio of the diatomaceous earth to the porous alumina is 5:1.

[0010] By adopting the above technical scheme, when the diatomaceous earth and porous alumina in the above weight ratio are used as a catalyst auxiliary agent, the coordination effect is relatively excellent, and it performs more prominently in accelerating the catalytic reaction process and ensuring the yield and purity of the product, thereby making the synthesis process of antioxidant 1135 have better application effect and strong industrial applicability.

[0011] Preferably, the diatomaceous earth has a particle size of 20-50 μm and a specific surface area of ​​40-60 m 2 / g, porosity is 60-70%; the particle size of the porous alumina is 60-80μm, and the specific surface area is 200-300m 2 / g, porosity is 30-50%.

[0012] By adopting the above technical scheme, when the diatomaceous earth and porous alumina of the above specifications are used in combination, the catalyst can not only be stably loaded thereon, but also a more suitable multi-stage loaded catalytic system can be formed, which has strong adaptability in exerting the coordinated characteristics of diatomaceous earth and porous alumina and ensuring the stable progress of the reaction, thereby enabling the catalytic auxiliary agent to exert a better application effect, that is, improving the catalytic reaction progress in the production process of antioxidant 1135, and ultimately obtaining excellent product yield and product purity.

[0013] Preferably, the catalyst is one or a combination of dibutyltin oxide, aluminum triisopropoxide, tetrabutyl titanate, potassium acetate and 2-ethylhexyl titanate.

[0014] By adopting the above technical solution, the catalyst reduces the activation energy of the reaction, allowing the reaction that was originally difficult to carry out to proceed under milder conditions, thereby accelerating the reaction rate and increasing the yield. The above types of catalysts can be applied to the synthesis process of antioxidant 1135 and bring excellent and stable corresponding effects.

[0015] Preferably, the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of (6-9):(1-3):1.

[0016] By adopting the above technical scheme, dibutyltin oxide has thermal stability and hydrolysis resistance, and has high catalytic activity; aluminum triisopropoxide has good thermal stability and chemical stability, and can carry out catalytic reactions at higher temperatures and pressures; the catalytic reaction rate of tetrabutyl titanate is fast, and side reactions are unlikely to occur during the process; and the combination of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in corresponding weight ratios as a catalyst can, on the one hand, have a more comprehensive catalytic effect, and on the other hand, can form a better synergistic effect with the catalytic auxiliary agent composed of diatomaceous earth and porous alumina, thereby obtaining a better product yield and product purity while improving the catalytic reaction process in the production process of antioxidant 1135, so that the synthesis process of antioxidant 1135 has a better application effect.

[0017] Preferably, the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of 8:2:1.

[0018] By adopting the above technical scheme, when the dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in the above weight ratio are used to form a catalyst, the synergistic coordination between them and the catalytic auxiliary agent is better, and the corresponding effect brought about is more excellent. On the premise of obtaining a higher catalytic reaction process, the product yield and product purity are better.

[0019] Preferably, the amount of the catalyst used is 0.4-0.6% of the mass of 3,5-methyl ester.

[0020] Preferably, the amount of the catalyst auxiliary agent used is 1.5-2.2% of the mass of 3,5-methyl ester.

[0021] Preferably, the mass ratio of the 3,5-methyl ester to isooctyl alcohol is 1:(1.5-1.7).

[0022] By adopting the above technical scheme, the amount of the above catalyst, the amount of the catalytic auxiliary agent, and the mass ratio of 3,5-methyl ester and isooctyl alcohol, not only can the catalyst and the catalytic auxiliary agent fully synergistically act in the reaction of 3,5-methyl ester and isooctyl alcohol, but also can be adapted to the requirements of the high catalytic reaction process, which is conducive to obtaining a higher product yield and product purity, thereby ensuring that the overall synthesis process of antioxidant 1135 has excellent and stable applicability.

[0023] Preferably, the synthesis process of antioxidant 1135 specifically comprises the following steps: (1) 3,5-methyl ester, catalyst and catalyst auxiliary agent are added to a reaction vessel, and after nitrogen replacement, the temperature is raised to 145-175° C. and stirred for 40-60 minutes, and then the temperature is kept at 175-180° C. and isooctyl alcohol is added to react for 80-100 minutes; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation at 185-195° C. for 10-30 min. After cooling, adsorption is performed using an adsorption filter aid, and antioxidant 1135 is obtained after filtration. The catalyst auxiliary agent in the above operation is a composition of diatomaceous earth and porous alumina in a weight ratio of (3-7):1.

[0024] By adopting the above technical scheme, in the above operation, the corresponding temperature and time control are selected, so that the catalyst and the catalytic auxiliary agent can be fully combined in the process, and the corresponding excellent effect can be brought about in the reaction process of 3,5-methyl ester and isooctyl alcohol, so that the interaction between the individual operations and the raw materials has better adaptability, and thus, on the premise of improving the catalytic reaction process in the production process of antioxidant 1135, it has excellent product yield and product purity.

[0025] In summary, this application has the following beneficial effects: 1. Since the present application uses a catalyst auxiliary agent composed of diatomaceous earth and porous alumina to form a multi-level loading on the catalyst, not only the overall activity, selectivity and stability of the catalyst are significantly improved, but also a regulatory effect can be brought about in the catalytic reaction process, which is beneficial to improving the catalytic reaction process in the production process of antioxidant 1135, and excellent product yield and product purity can be obtained; 2. Since the present application combines dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in corresponding weight ratios as catalysts, the synergistic coordination between the catalyst and the catalytic auxiliary agent is better, and it is more suitable for the reaction process of 3,5-methyl ester and isooctyl alcohol, thereby improving the catalytic reaction process in the production process of antioxidant 1135, and can obtain better product yield and product purity. DETAILED DESCRIPTION

[0026] The present application is further described in detail below in conjunction with embodiments and comparative examples.

[0027] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of the present application are commercially available: Diatomaceous earth was purchased from Jiayuan Mineral Products Processing Plant in Lingshou County; Porous alumina was purchased from Jiangxi Zhongxu Technology Co., Ltd., and the implementation standard was HG / T3927-2020; The adsorption filter aid is activated clay, which is activated clay 1060 purchased from Guangzhou Yifeng Chemical Technology Co., Ltd. Example

[0028] Example 1 A synthesis process of antioxidant 1135 comprises the following steps: (1) 3,5-methyl ester, catalyst and catalyst auxiliary agent are added to a reaction vessel, and after nitrogen replacement, the temperature is raised to 160° C. and stirred for 50 min. Then, isooctanol is added and the temperature is maintained at 177.5° C. to react for 90 min; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation at 190° C. for 10-30 min. After cooling, adsorption is performed using an adsorption filter aid, and antioxidant 1135 is obtained after filtration.

[0029] Note: The catalyst auxiliary agent in the above operation is a composition of diatomaceous earth and porous alumina in a weight ratio of 5:1; the particle size of diatomaceous earth is 35μm and the specific surface area is 50m 2 / g, porosity is 65%; the particle size of porous alumina is 70μm, and the specific surface area is 250m 2 / g, porosity is 40%; the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of 8:2:1; the amount of the catalyst is 0.5% of the mass of 3,5-methyl ester; the amount of the catalytic auxiliary is 1.85% of the mass of 3,5-methyl ester; the mass ratio of 3,5-methyl ester to isooctyl alcohol is 1:1.6.

[0030] Example 2 A synthesis process of antioxidant 1135, which is different from that of Example 1, specifically comprises the following steps: (1) 3,5-methyl ester, catalyst and catalyst auxiliary agent are added to a reaction vessel, and after nitrogen replacement, the temperature is raised to 145° C. and stirred for 60 minutes, and then the temperature is maintained at 180° C. and isooctyl alcohol is added to react for 80 minutes; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation at 185° C. for 30 min. After cooling, adsorption is performed using an adsorption filter aid, and antioxidant 1135 is obtained after filtration.

[0031] Example 3 A synthesis process of antioxidant 1135, which is different from that of Example 1, specifically comprises the following steps: (1) 3,5-methyl ester, catalyst and catalyst auxiliary agent are added to a reaction vessel, and after nitrogen replacement, the temperature is raised to 175° C. and stirred for 40 minutes, and then isooctanol is added while maintaining the temperature at 175° C. to react for 100 minutes; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation at 195° C. for 10 min. After cooling, adsorption is carried out using an adsorption filter aid, and antioxidant 1135 is obtained after filtration.

[0032] Example 4 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalytic auxiliary agent is a composition of diatomaceous earth and porous alumina in a weight ratio of 3:1.

[0033] Example 5 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalyst auxiliary agent is a composition of diatomaceous earth and porous alumina in a weight ratio of 8:1.

[0034] Example 6 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalytic auxiliary agent is a composition of diatomaceous earth and porous alumina in a weight ratio of 5.5:1.

[0035] Example 7 A synthesis process of antioxidant 1135, which is different from Example 1 in that the particle size of diatomaceous earth is 20 μm and the specific surface area is 40 m 2 / g, porosity is 60%; the particle size of porous alumina is 60μm, and the specific surface area is 200m 2 / g, and the porosity is 30%.

[0036] Example 8 A synthesis process of antioxidant 1135, which is different from Example 1 in that the particle size of diatomaceous earth is 50 μm and the specific surface area is 60 m 2 / g, porosity is 70%; the particle size of porous alumina is 80μm, and the specific surface area is 300m 2 / g, porosity is 50%.

[0037] Example 9 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of 7.5:2:1.

[0038] Example 10 A synthesis process of an antioxidant 1135, which is different from that of Example 1 in that the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of 6:1:1.

[0039] Embodiment 11 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of 9:3:1.

[0040] Example 12 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that dibutyltin oxide is not used in the catalyst.

[0041] Example 13 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that aluminum triisopropoxide is not used in the catalyst.

[0042] Embodiment 14 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that tetrabutyl titanate is not used in the catalyst.

[0043] Embodiment 15 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that dibutyltin oxide and tetrabutyl titanate are not used in the catalyst.

[0044] Example 16 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that aluminum triisopropoxide and tetrabutyl titanate are not used in the catalyst.

[0045] Embodiment 17 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that dibutyltin oxide and aluminum triisopropoxide are not used in the catalyst.

[0046] Embodiment 18 A synthesis process of antioxidant 1135 is different from that of Example 1 in that the amount of catalyst used is 0.4% of the mass of 3,5-methyl ester.

[0047] Embodiment 19 A synthesis process of antioxidant 1135 is different from that of Example 1 in that the amount of catalyst used is 0.6% of the mass of 3,5-methyl ester.

[0048] Embodiment 20 A synthesis process of antioxidant 1135 is different from that of Example 1 in that the amount of the catalyst auxiliary agent used is 1.5% of the mass of 3,5-methyl ester.

[0049] Embodiment 21 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the amount of the catalyst auxiliary agent used is 2.2% of the mass of 3,5-methyl ester.

[0050] Embodiment 22 A synthesis process of antioxidant 1135, which is different from Example 1 in that the mass ratio of 3,5-methyl ester to isooctyl alcohol is 1:1.5.

[0051] Embodiment 23 A synthesis process of antioxidant 1135, which is different from Example 1 in that the mass ratio of 3,5-methyl ester to isooctyl alcohol is 1:1.7.

[0052] Comparative Example Comparative Example 1 A synthesis process of an antioxidant 1135, which is different from that of Example 1 in that no catalytic auxiliary agent is used in the operation of step (1).

[0053] Comparative Example 2 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalyst auxiliary agent does not contain diatomaceous earth.

[0054] Comparative Example 3 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalytic auxiliary agent does not contain porous alumina.

[0055] Comparative Example 4 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalyst auxiliary agent is a composition of diatomaceous earth and porous alumina in a weight ratio of 2.5:1.

[0056] Comparative Example 5 A synthesis process of an antioxidant 1135 is different from that of Example 1 in that the catalyst auxiliary agent is a composition of diatomaceous earth and porous alumina in a weight ratio of 8.5:1.

[0057] Performance test test method: The synthesis process of antioxidant 1135 described in Examples 1-23 and Comparative Examples 1-5 was applied to calculate the product yield and product purity respectively; Product yield = actual antioxidant 1135 mass obtained / theoretical yield; Product purity = mass of effective substance (antioxidant 1135) / total mass of mixture.

[0058] Table 1 Application test results of Examples 1-23 and Comparative Examples 1-5 Synthesis process of antioxidant 1135 Product yield (%) Product purity (%) Example 1 99.73 99.47 Example 2 99.54 99.28 Example 3 99.62 99.36 Example 4 99.67 99.41 Example 5 99.58 99.32 Example 6 99.60 99.34 Example 7 99.64 99.38 Example 8 99.57 99.31 Example 9 99.69 99.43 Example 10 99.63 99.37 Embodiment 11 99.59 99.33 Example 12 99.43 99.17 Embodiment 13 99.36 99.11 Embodiment 14 99.41 99.14 Embodiment 15 99.25 99.01 Example 16 99.24 99.04 Embodiment 17 99.28 99.03 Embodiment 18 99.61 99.35 Embodiment 19 99.55 99.29 Embodiment 20 99.68 99.42 Embodiment 21 99.70 99.44 Embodiment 22 99.65 99.39 Embodiment 23 99.71 99.45 Comparative Example 1 94.56 94.18 Comparative Example 2 96.51 96.32 Comparative Example 3 96.35 96.07 Comparative Example 4 98.27 98.21 Comparative Example 5 98.34 98.27 It can be seen from the combination of Examples 1-3 and Comparative Examples 1-3 and Table 1 that the use of a catalytic auxiliary agent composed of diatomite and porous alumina can greatly shorten the catalytic reaction time, thereby improving the catalytic reaction process; at the same time, under a higher catalytic reaction process, a higher product yield and product purity can also be obtained, so that the synthesis process of antioxidant 1135 has a higher applicability. If a catalytic auxiliary agent is not used, it is found that the product yield and product purity obtained by the application test are significantly low, indicating that the catalytic reaction cannot be completed in a shorter time, and the purpose of improving the catalytic reaction process cannot be achieved; if any one of diatomite and porous alumina is used alone as a catalytic auxiliary agent, although it can bring about an increase in product yield and product purity to a certain extent, it is far less than the significant effect brought by the compound application of diatomite and porous alumina. It can be seen that only when diatomite and porous alumina are used in combination, the catalytic reaction process in the production process of antioxidant 1135 can be improved, and excellent product yield and product purity can be obtained.

[0059] Combining Example 1 and Examples 4-6 with Table 1, it can be seen that when the weight ratio of diatomaceous earth and porous alumina is 5:1, the application effect of the catalytic auxiliary agent is better, and it is more prominent in accelerating the catalytic reaction process and ensuring the yield and purity of the product; Combining Comparative Examples 4-5 with Table 1, it can be seen that when the weight ratio of diatomaceous earth and porous alumina exceeds the range of (3-8): 1 to form a catalytic auxiliary agent, it is found that the product yield and product purity obtained in the application test are significantly lower, indicating that based on the premise of the application of diatomaceous earth and porous alumina as a catalytic auxiliary agent, it is necessary to use them in combination within a specific ratio range to bring about a more prominent and significant application effect.

[0060] Combining Example 1 with Examples 7-8 and Table 1, it can be seen that the particle size of diatomaceous earth is 20-50 μm and the specific surface area is 40-60 m 2 / g, porosity is 60-70%; the particle size of porous alumina is 60-80μm, and the specific surface area is 200-300m 2 / g, and the porosity is 30-50%; the catalytic auxiliary agent can exert a better application effect, and the product yield and product purity obtained through application testing are better.

[0061] It can be seen from Example 1 and Examples 9-11 and Table 1 that when the catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of (6-9):(1-3):1, it can exert excellent and stable effects, and the product yield and product purity obtained by application testing are both high. Among them, when the weight ratio of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate is 8:2:1, the effect brought by the application of the catalyst is better. Combined with Examples 12-17 and Table 2, it can be seen that if any one or two of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate are used as catalysts, the product yield and product purity obtained by application testing are significantly reduced, indicating that the synergistic coordination between the catalyst and the catalytic auxiliary agent is poor. It can be seen that the present application combines dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a corresponding weight ratio as a catalyst, so that the synergistic coordination between the catalyst and the catalytic auxiliary agent is better, thereby improving the catalytic reaction process in the production process of antioxidant 1135. , It can be obtained better product yield and product purity.

[0062] It can be seen from Example 1 and Examples 18-23 and Table 1 that in the synthesis process of antioxidant 1135, the amount of catalyst used is 0.4-0.6% of the mass of 3,5-methyl ester, the amount of catalytic auxiliary used is 1.5-2.2% of the mass of 3,5-methyl ester, and the mass ratio of 3,5-methyl ester to isooctyl alcohol is 1:(1.5-1.7), which are all suitable for the requirements of high catalytic reaction process and can obtain stable and high product yield and product purity.

[0063] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A synthesis process of antioxidant 1135, characterized in that: The following steps are involved: (1) 3,5-methyl ester, catalyst and catalyst auxiliary agent are added to a reaction vessel, and after nitrogen replacement, the temperature is raised and stirring is started, and then isooctanol is added while the temperature is maintained to react; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation, and after cooling, adsorption is performed using an adsorption filter aid, and antioxidant 1135 is obtained after filtration; The catalyst auxiliary agent in the above operation is a composition of diatomaceous earth and porous alumina in a weight ratio of (3-8):

1.

2. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The weight ratio of the diatomaceous earth to the porous alumina is 5:

1.

3. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The particle size of the diatomaceous earth is 20-50 μm, and the specific surface area is 40-60 m 2 / g, the porosity is 60-70%; the particle size of the porous alumina is 60-80μm, and the specific surface area is 200-300m 2 / g, porosity is 30-50%.

4. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The catalyst is one or a combination of dibutyltin oxide, aluminum triisopropoxide, tetrabutyl titanate, potassium acetate and 2-ethylhexyl titanate.

5. The synthesis process of antioxidant 1135 according to claim 4, characterized in that: The catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of (6-9):(1-3):

1.

6. The synthesis process of antioxidant 1135 according to claim 5, characterized in that: The catalyst is a mixture of dibutyltin oxide, aluminum triisopropoxide and tetrabutyl titanate in a weight ratio of 8:2:

1.

7. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The amount of the catalyst used is 0.4-0.6% of the mass of 3,5-methyl ester.

8. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The dosage of the catalyst auxiliary agent is 1.5-2.2% of the mass of 3,5-methyl ester.

9. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The mass ratio of the 3,5-methyl ester to isooctyl alcohol is 1:(1.5-1.7).

10. The synthesis process of antioxidant 1135 according to claim 1, characterized in that: The specific steps include: (1) 3,5-methyl ester, catalyst and catalyst auxiliary agent are added to a reaction vessel, and after nitrogen replacement, the temperature is raised to 145-175°C and stirred for 40-60 minutes, and then the temperature is kept at 175-180°C and isooctyl alcohol is added to react for 80-100 minutes; (2) After the reaction in step (1) is completed, unreacted isooctyl alcohol is removed by distillation at 185-195° C. for 10-30 min. After cooling, adsorption is performed using an adsorption filter aid, and antioxidant 1135 is obtained after filtration. The catalyst auxiliary agent in the above operation is a composition of diatomaceous earth and porous alumina in a weight ratio of (3-7):1.