A high-temperature resistant antioxidant composition and its preparation method

Abstract

The present application relates to the field of antioxidant technology, and more specifically, to a high-temperature resistant antioxidant composition and its preparation method. A high-temperature resistant antioxidant composition includes 10-20 parts of an amine antioxidant, 5-10 parts of a phosphite antioxidant, and 8 parts of a zinc thiophosphate. The preparation method is as follows: after mixing the amine antioxidant, the phosphite antioxidant, and the zinc thiophosphate, stirring and mixing for 0.5-1h under a vacuum degree of (-0.4)-(-0.2) MPa, a high-temperature resistant antioxidant composition is obtained. The high-temperature resistant antioxidant composition of the present application can not only capture peroxyl radicals in hydraulic oil and terminate free radical chain reactions, but also decompose hydroperoxides and peroxides in hydraulic oil, thereby improving the antioxidant properties of hydraulic oil in high-temperature environments.

Description

Technical Field

[0001] The present application relates to the technical field of antioxidants, and more specifically, to a high-temperature resistant antioxidant composition and a preparation method thereof. Background Art

[0002] Hydraulic oil is the hydraulic medium used in hydraulic systems that utilize liquid pressure energy. It plays the roles of energy transmission, anti-wear, system lubrication, corrosion prevention, rust prevention, and cooling in hydraulic systems.

[0003] Antioxidants are commonly used additives in hydraulic oils. They can produce complex films on the metal surface, isolating oxygen and other corrosive substances, preventing the metal from catalyzing the hydraulic oil and the hydraulic oil from corroding the components.

[0004] However, although hydraulic oil contains antioxidants, it is still very easy to oxidize and deteriorate when used in a high-temperature environment. The harmful acidic substances it produces will accelerate the corrosion of components such as hydraulic valves and reduce the efficiency of the hydraulic system. Summary of the Invention

[0005] In order to improve the oxidation resistance of hydraulic oil in a high-temperature environment, the present application provides a high-temperature resistant antioxidant composition and a preparation method thereof.

[0006] In a first aspect, the present application provides a high temperature resistant antioxidant composition, which adopts the following technical solution:

[0007] A high temperature resistant antioxidant composition comprises the following components in parts by weight:

[0008] 10-20 parts of amine antioxidant;

[0009] 5-10 parts of phosphite antioxidant;

[0010] 5-8 parts of zinc thiophosphate.

[0011] By adopting the above technical solution, the combination of an amine antioxidant, a phosphite antioxidant, and a zinc thiophosphate added to the hydraulic oil creates a highly dispersed and stable mixture. This combination not only captures peroxyl radicals in the hydraulic oil, terminating free radical chain reactions, but also decomposes hydroperoxides and peroxides in the hydraulic oil, reducing the number of free radicals generated by the decomposition of hydroperoxides and peroxides. Therefore, the addition of the antioxidant composition of the present application to the hydraulic oil improves the hydraulic oil's antioxidant properties in high-temperature environments, reduces the content of harmful acidic substances in the hydraulic oil, and mitigates the impact of oxidative deterioration of the hydraulic oil on the efficiency of the hydraulic system.

[0012] Preferably, the amine antioxidant, the phosphite antioxidant and the zinc thiophosphate are mixed in a weight ratio of 1:(0.33-0.60):(0.38-0.53).

[0013] By adopting this technical solution, the three components achieve a synergistic effect, decomposing peroxides while also slowing the chain propagation of free radicals, effectively controlling the increase in acid value. Therefore, further optimizing the weight ratio of the amine antioxidant, phosphite antioxidant, and zinc thiophosphate not only improves the antioxidant properties of hydraulic oil in high-temperature environments and reduces precipitate formation, but also facilitates the antioxidant composition's decomposition of harmful acidic substances in the hydraulic oil.

[0014] Preferably, the amine antioxidant is one or both of a naphthylamine antioxidant and a p-phenylenediamine antioxidant.

[0015] By adopting the above technical solution, naphthylamine antioxidants and p-phenylenediamine antioxidants possess excellent free radical and desulfurization properties, are ashless, have low volatility, and have good mineral oil solubility. Therefore, adding naphthylamine antioxidants and / or p-phenylenediamine antioxidants to an antioxidant composition improves the antioxidant properties of the antioxidant composition and reduces the tendency to form sludge, thereby helping to reduce the amount of sediment in hydraulic oils used in high-temperature environments.

[0016] Preferably, the amine antioxidant is composed of a mixture of a naphthylamine antioxidant and a p-phenylenediamine antioxidant in a weight ratio of 1:(0.8-1.2).

[0017] By adopting the above technical solution, the naphthylamine antioxidant and the p-phenylenediamine antioxidant are compounded according to the above weight ratio. The resulting amine antioxidant has a certain active nitrogen content, and the alkalinity value of the obtained antioxidant composition is certain, which reduces the effect of acid on the phosphite antioxidant and the zinc thiophosphate, and is beneficial to improving the stability of the phosphite antioxidant and the zinc thiophosphate, thereby improving the antioxidant properties of the antioxidant composition and its decomposition efficiency of harmful acidic substances in hydraulic oil in high-temperature environments.

[0018] Preferably, the p-phenylenediamine antioxidant is one or more of N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine and N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine.

[0019] By adopting the above technical solution, the above-mentioned type of p-phenylenediamine antioxidant has excellent free radical and desulfurization properties, and adding it to the antioxidant composition is conducive to further improving the antioxidant performance of the antioxidant composition.

[0020] Preferably, the phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, diphenyl isodecyl phosphite and triphenyl phosphite.

[0021] By adopting the above technical solution, the above-mentioned type of phosphite antioxidant can combine with unstable oxygen in hydroperoxide and reduce it to stable alcohol substances, which is beneficial to improving the antioxidant property of the antioxidant combination.

[0022] Preferably, the phosphite antioxidant is tris(2,4-di-tert-butylphenyl)phosphite and triphenyl phosphite.

[0023] By adopting the above technical solution, tris(2,4-di-tert-butylphenyl)phosphite and triphenyl phosphite have a stronger steric hindrance effect, are more stable, and are not easily hydrolyzed, which is beneficial for controlling the increase in the acid value in the hydraulic oil and decomposing the sediment in the hydraulic oil.

[0024] Preferably, the zinc thiophosphate salt is zinc dialkyl dithiophosphate or zinc thiophosphate propyl octyl secondary alkyl zinc salt.

[0025] By adopting the above technical solution, zinc dialkyl dithiophosphates and secondary alkyl zinc salts of thiophosphate, propyl octane, and octane exhibit excellent antioxidant properties, thermal stability, and hydrolytic stability. Adding zinc dialkyl dithiophosphates and secondary alkyl zinc salts of thiophosphate, propyl octane, and octane to an antioxidant composition can improve the antioxidant composition's efficiency in decomposing peroxides in hydraulic oil, reduce the amount of sediment in hydraulic oil in high-temperature environments, and enhance the antioxidant properties of the antioxidant composition.

[0026] In a second aspect, the present application provides a method for preparing a high-temperature resistant antioxidant composition, which adopts the following technical solution:

[0027] A method for preparing a high-temperature resistant antioxidant composition comprises the following steps:

[0028] After mixing an amine antioxidant, a phosphite antioxidant and zinc thiophosphate, the mixture is stirred for 0.5-1h under a vacuum degree of (-0.4)-(-0.2) MPa to obtain a high-temperature resistant antioxidant composition.

[0029] By adopting the above technical solution, the mixture of the amine antioxidant, the phosphite antioxidant and the zinc thiophosphate is stirred and mixed under a vacuum environment, which is conducive to removing moisture and improving the stability of the obtained antioxidant composition.

[0030] In summary, this application has the following beneficial effects:

[0031] 1. The antioxidant composition obtained by compounding amine antioxidants, phosphite antioxidants and zinc thiophosphate not only has good antioxidant properties, but also has good dispersibility and a low tendency to generate sludge. When added to hydraulic oil, it can effectively terminate the free radical chain reaction, control the increase in acid value, decompose sediments, and improve the antioxidant properties of hydraulic oil in high temperature environments.

[0032] 2. The use of naphthylamine antioxidants and p-phenylenediamine antioxidants in combination with phosphite antioxidants and zinc thiophosphate can adjust the pH environment in the antioxidant composition. When the antioxidant composition is added to the hydraulic oil as an additive, the effect of acidic substances in the hydraulic oil in a high-temperature environment on the phosphite antioxidants and zinc thiophosphate can be reduced, thereby improving the decomposition efficiency of the antioxidant composition on acidic substances in the hydraulic oil. DETAILED DESCRIPTION

[0033] The present application is further described in detail below with reference to the embodiments.

[0034] Performance testing

[0035] The high temperature resistant antioxidant composition obtained in the example of the present application and the antioxidant composition obtained in the comparative example were used as the test samples, and were added to mineral oil (model Rimula R2E15W40, purchased from Shanghai Kaiyin Chemical Co., Ltd.) at an addition amount of 0.4 wt%. After stirring for 30 minutes, the oxidation stability, acid value and sediment were tested. The test method is as follows:

[0036] Oxidation stability test: refer to SH / T 0193-2008 Determination of oxidation stability of lubricating oils - rotating oxygen bomb method.

[0037] Acid value and sediment test: refer to SH / T 0811-2010.

[0038] Example

[0039] Example 1

[0040] A high temperature resistant antioxidant composition, the components and their corresponding weights are shown in the following table:

[0041]

[0042] The preparation method of the above-mentioned high temperature resistant antioxidant composition comprises the following steps:

[0043] After mixing the amine antioxidant, the phosphite antioxidant and the zinc thiophosphate, the mixture was stirred for 0.5-1h (0.5h in the embodiment of the present application) under a vacuum degree of (-0.4)-(-0.2)MPa (-0.2MPa in the embodiment of the present application) to obtain a high temperature resistant antioxidant composition.

[0044] The high temperature resistant antioxidant compositions obtained in Examples 1-5 of the present application were used as test samples. They were added to hydraulic oil at an addition amount of 0.4 wt %. After stirring and mixing for 30 minutes, oxidation stability, acid value, and sedimentation tests were performed. The test results are shown in the following table:

[0045]

[0046] By analyzing the data in the above table, it can be seen that the high-temperature resistant antioxidant compositions of Examples 3-5 have higher oxidation stability, lower acid value and lower precipitate than the high-temperature resistant antioxidant compositions of Examples 1 and 2. This shows that in the high-temperature resistant antioxidant composition of the present application, the amine antioxidant, the phosphite antioxidant and the zinc thiophosphate are mixed in a weight ratio of 1:(0.33-0.60):(0.38-0.53), which can improve the antioxidant properties of the high-temperature resistant antioxidant composition in a high-temperature environment. When added to hydraulic oil, it can effectively reduce the acid value and sediment content of the hydraulic oil in a high-temperature environment.

[0047] Examples 6-9

[0048] A high temperature resistant antioxidant composition, which is different from Example 3 in that the types and weights of the amine antioxidants are shown in the following table:

[0049]

[0050]

[0051] The high temperature resistant antioxidant compositions obtained in Examples 6-10 of the present application were used as test samples. They were added to hydraulic oil at an addition amount of 0.4 wt %. After stirring and mixing for 30 minutes, oxidation stability, acid value, and sediment were tested. The test results are shown in the following table:

[0052]

[0053] By analyzing the data in the above table, it can be seen that the high-temperature resistant antioxidant compositions of Examples 3 and 4 have higher oxidation stability, lower acid value and precipitate than the high-temperature resistant antioxidant composition of Example 7.

[0054] Compared with the high-temperature resistant antioxidant compositions of Examples 9 and 10, the high-temperature resistant antioxidant composition of Example 8 has higher oxidation stability, lower acid value and lower precipitate.

[0055] This shows that in the high-temperature resistant antioxidant composition of the present application, the amine antioxidant is a naphthylamine antioxidant and / or a p-phenylenediamine antioxidant, and in particular, the amine antioxidant is composed of a mixture of a naphthylamine antioxidant and a p-phenylenediamine antioxidant in a weight ratio of 1:1. The resulting high-temperature resistant antioxidant composition has higher antioxidant properties and is added to hydraulic oil to effectively reduce the acid value and sediment content of the hydraulic oil.

[0056] In the examples of the present application, when the amine antioxidant is composed of a mixture of a naphthylamine antioxidant and a p-phenylenediamine antioxidant in a weight ratio of 1:(0.8-1.2), the oxidation stability, acid value, and precipitate test results of the high-temperature resistant antioxidant composition are similar to those of Example 8. Therefore, the examples of the present application are only briefly described based on the example of Example 8 in which the amine antioxidant is composed of a mixture of a naphthylamine antioxidant and a p-phenylenediamine antioxidant in a weight ratio of 1:1, but this does not affect the application of other weight ratios of naphthylamine antioxidants and p-phenylenediamine antioxidants in the present application.

[0057] Examples 11-12

[0058] A high temperature resistant antioxidant composition, which is different from Example 8 in that the types and weights of the amine antioxidants are shown in the following table:

[0059]

[0060]

[0061] The high temperature resistant antioxidant compositions obtained in Examples 11 and 12 of the present application were used as test samples. They were added to hydraulic oil at an addition amount of 0.4 wt %. After stirring and mixing for 30 minutes, oxidation stability tests were performed. The test results are shown in the following table:

[0062]

[0063] Analysis of the data in the table above shows that the oxidation stability of Examples 8, 11, and 12 is as high as 215-217 minutes. This indicates that in the high-temperature resistant antioxidant composition of the present application, the phenylenediamine antioxidant is one or three of N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, and N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine. The resulting high-temperature resistant antioxidant composition has higher antioxidant properties and can effectively reduce the acid value and sediment content of the hydraulic oil when added to the hydraulic oil.

[0064] Examples 13-15

[0065] A high temperature resistant antioxidant composition, which differs from Example 8 in that the types and weights of the phosphite antioxidants are shown in the following table:

[0066]

[0067] The high temperature resistant antioxidant compositions obtained in Examples 13, 14, and 15 of the present application were used as test samples. They were added to hydraulic oil at an addition amount of 0.4 wt %. After stirring and mixing for 30 minutes, oxidation stability, acid value, and sediment were tested. The test results are shown in the following table:

[0068]

[0069] By analyzing the data in the above table, it can be seen that the high-temperature resistant antioxidant compositions of Examples 8, 13, 14, and 15 have higher oxidation stability, lower acid value, and lower precipitate than the high-temperature resistant antioxidant composition of Example 15. This shows that in the high-temperature resistant antioxidant composition of the present application, the phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, diphenylisodecyl phosphite, and triphenyl phosphite. The resulting high-temperature resistant antioxidant composition has higher antioxidant properties and can effectively reduce the acid value and precipitate content of the hydraulic oil when added to the hydraulic oil.

[0070] Examples 16-17

[0071] A high temperature resistant antioxidant composition, which differs from Example 13 in that the types and weights of zinc thiophosphate salts are shown in the following table:

[0072]

[0073] The high temperature resistant antioxidant compositions obtained in Examples 16 and 17 of the present application were used as test samples. They were added to hydraulic oil at an addition amount of 0.4 wt %. After stirring and mixing for 30 minutes, oxidation stability and sedimentation tests were performed. The test results are shown in the following table:

[0074]

[0075] Analysis of the data in the table above shows that the high-temperature resistant antioxidant compositions of Examples 13 and 16 have higher oxidative stability and lower precipitate content than the high-temperature resistant antioxidant composition of Example 17. This indicates that in the high-temperature resistant antioxidant composition of the present application, the zinc thiophosphate salt is a zinc dialkyl dithiophosphate or a secondary alkyl zinc thiophosphate propionate octane salt, which can improve the antioxidant properties of the resulting high-temperature resistant antioxidant composition and effectively reduce the precipitate content of the hydraulic oil when added to the hydraulic oil.

[0076] Comparative Example

[0077] Comparative Example 1

[0078] An antioxidant composition, which differs from Example 3 in that an equal weight of a phenolic antioxidant is used to replace the amine antioxidant, wherein the phenolic antioxidant is 2,6-di-tert-butylphenol.

[0079] Comparative Example 2

[0080] An antioxidant composition, which differs from Example 3 in that an equal weight of a sulfur-containing antioxidant is used to replace the phosphite antioxidant, wherein the sulfur-containing antioxidant is dimyristyl thiodipropionate.

[0081] Comparative Example 3

[0082] An antioxidant composition, which differs from Example 3 in that an equal weight of dialkyl dithiocarbamate is used to replace zinc thiophosphate, wherein the dialkyl dithiocarbamate is sodium dimethyl dithiocarbamate.

[0083] Comparative Example 4

[0084] An antioxidant composition, which differs from Example 3 in that an equal weight of a phenolic antioxidant is used to replace the amine antioxidant, and an equal weight of a sulfur-containing antioxidant is used to replace the phosphite antioxidant, wherein the phenolic antioxidant is 2,6-di-tert-butylphenol and the sulfur-containing antioxidant is dimyristyl thiodipropionate.

[0085] Comparative Example 5

[0086] An antioxidant composition, which differs from Example 3 in that an equal weight of a phenolic antioxidant is used instead of an amine antioxidant, and an equal weight of a dialkyl dithiocarbamate is used instead of a zinc thiophosphate, wherein the phenolic antioxidant is 2,6-di-tert-butylphenol, and the dialkyl dithiocarbamate is sodium dimethyldithiocarbamate.

[0087] Comparative Example 6

[0088] An antioxidant composition, which differs from Example 3 in that an equal weight of a sulfur-containing antioxidant is used to replace the phosphite antioxidant, and an equal weight of a dialkyl dithiocarbamate is used to replace the zinc thiophosphate, wherein the sulfur-containing antioxidant is dimyristyl thiodipropionate, and the dialkyl dithiocarbamate is sodium dimethyldithiocarbamate.

[0089] The antioxidant compositions obtained in Comparative Examples 1-6 of the present application were used as test samples. They were added to hydraulic oil at an addition amount of 0.4 wt %. After stirring and mixing for 30 minutes, oxidation stability, acid value, and sedimentation tests were performed. The test results are shown in the following table:

[0090]

[0091] By analyzing the data in the above table, it can be seen that the high-temperature resistant antioxidant composition of Example 3 has a relative improvement of 10.33-17.34% in oxidation stability, a relative reduction of 57.14-76.92% in acid value, and a relative reduction of 50.00-72.22% in sediment compared to the antioxidant compositions of Comparative Examples 1-6. This shows that the use of an amine antioxidant, a phosphite antioxidant, and a zinc thiophosphate in the total raw materials for preparing the high-temperature resistant antioxidant composition of the present application can improve the antioxidant properties of the high-temperature resistant antioxidant composition in a high-temperature environment, and when added to hydraulic oil, it can effectively reduce the acid value and sediment content of the hydraulic oil in a high-temperature environment.

[0092] 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 non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high temperature resistant antioxidant composition, characterized in that It is composed of the following components in parts by weight: 10-20 parts of amine antioxidant; 5-10 parts of phosphite antioxidant; 5-8 parts of zinc thiophosphate; The amine antioxidant is composed of a mixture of a naphthylamine antioxidant and a p-phenylenediamine antioxidant in a weight ratio of 1:(0.8-1.2); The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, diphenyl isodecyl phosphite and triphenyl phosphite.

2. The high temperature resistant antioxidant composition according to claim 1, characterized in that The amine antioxidant, the phosphite antioxidant and the zinc thiophosphate are mixed in a weight ratio of 1:(0.33-0.60):(0.38-0.53).

3. The high temperature resistant antioxidant composition according to claim 1, characterized in that The p-phenylenediamine antioxidant is one or more of N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine and N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine.

4. The high temperature resistant antioxidant composition according to claim 3, characterized in that The phosphite antioxidants are tris(2,4-di-tert-butylphenyl)phosphite and triphenyl phosphite.

5. The high temperature resistant antioxidant composition according to claim 1, characterized in that The zinc thiophosphate is zinc dialkyl dithiophosphate.

6. The method for preparing the high temperature resistant antioxidant composition according to any one of claims 1 to 5, characterized in that: The following steps are involved: After mixing an amine antioxidant, a phosphite antioxidant and zinc thiophosphate, the mixture is stirred for 0.5-1h under a vacuum degree of (-0.4)-(-0.2) MPa to obtain a high-temperature resistant antioxidant composition.

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