An antioxidant composition with adjustable viscosity

Abstract

This application relates to the technical field of hydraulic oils, and specifically discloses an antioxidant composition with adjustable viscosity. An antioxidant composition with adjustable viscosity includes the following components in parts by weight: 10-20 parts of thio hindered phenol antioxidants and 5-8 parts of thiocarbamate. This application uses a compound of thio hindered phenol antioxidants and thiocarbamate. The obtained antioxidant composition not only has good free radical scavenging ability, but also can promote the decomposition of hydroperoxides, which is beneficial to increasing the oxidation induction period of hydraulic oils, effectively inhibiting the increase in viscosity and the formation of precipitates after the oxidation of hydraulic oils.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic oil, and more specifically, to an antioxidant composition with adjustable viscosity. Background Art

[0002] Hydraulic oil is a hydraulic medium used in hydraulic systems that utilize the hydraulic energy of liquids, and it plays roles such as energy transfer, anti-wear, system lubrication, anti-corrosion, rust prevention, and cooling in hydraulic systems.

[0003] During the use of hydraulic oil, due to frequent contact with air, it will oxidize and deteriorate, resulting in an increase in viscosity and the generation of impurities. Therefore, the resistance of the hydraulic system increases, leading to an increase in energy consumption.

[0004] Although adding antioxidants can effectively slow down the oxidation and deterioration of hydraulic oil. However, during the use of hydraulic oil, the antioxidants are continuously consumed, so the viscosity of the hydraulic oil will gradually increase. Summary of the Invention

[0005] In order to improve the antioxidant performance of antioxidants and improve the phenomenon that the viscosity of hydraulic oil gradually increases during use, the present application provides an antioxidant composition with adjustable viscosity.

[0006] The present application provides an antioxidant composition with adjustable viscosity, adopting the following technical solution:

[0007] An antioxidant composition with adjustable viscosity, comprising the following components in parts by weight:

[0008] 10 - 20 parts of thio hindered phenol antioxidant;

[0009] 5 - 8 parts of thiocarbamate.

[0010] By adopting the above technical solution, the thio hindered phenol antioxidant has the characteristics of large molecular weight and high thermal stability. Adding the antioxidant composition obtained by compounding the thio hindered phenol antioxidant and thiocarbamate to hydraulic oil, on the one hand, since the thio hindered phenol antioxidant can react with free radicals in the hydraulic oil, scavenge free radicals in the hydraulic oil, form hydroperoxides, and inhibit the progress of the oxidation chain reaction; the thio hindered phenol antioxidant and thiocarbamate can decompose the hydroperoxides generated in the hydraulic oil into stable alcohol substances, terminating the degradation of the hydraulic oil. Therefore, the antioxidant performance of the antioxidant composition is improved, effectively inhibiting the increase in the viscosity of the hydraulic oil.

[0011] On the other hand, after the thio hindered phenolic antioxidant gives a free radical proton, the formed phenolic oxygen free radical can form a hydrogen bond with the sulfur-containing thiocarbamate, showing a significant synergistic effect. It not only promotes the decomposition of hydroperoxides, but also improves the stability of the phenolic oxygen free radical, which is beneficial to improving the antioxidant efficiency of the antioxidant composition, increasing the oxidation induction period of the hydraulic oil, and effectively inhibiting the increase in viscosity after the oxidation of the hydraulic oil.

[0012] Preferably, the antioxidant composition with adjustable viscosity further comprises a diphenylamine antioxidant.

[0013] By adopting the above technical solution, the diphenylamine antioxidant has a good free radical scavenging effect and can control the formation of precipitates in the hydraulic oil. When the diphenylamine antioxidant is added to the antioxidant composition, the diphenylamine antioxidant and the thio hindered phenolic antioxidant can jointly scavenge free radicals in the hydraulic oil, which is beneficial to improving the antioxidant efficiency of the antioxidant composition, inhibiting the increase in viscosity of the hydraulic oil and the formation of precipitates.

[0014] Preferably, the antioxidant composition with adjustable viscosity comprises the following components in parts by weight:

[0015] 10 - 20 parts of thio hindered phenolic antioxidant;

[0016] 5 - 8 parts of thiocarbamate;

[0017] 5 - 10 parts of diphenylamine antioxidant.

[0018] By adopting the above technical solution, in the antioxidant composition with adjustable viscosity, adding the diphenylamine antioxidant in the above parts by weight, the obtained antioxidant composition has a better free radical scavenging effect and hydroperoxide decomposition efficiency, which is beneficial to increasing the oxidation induction period of the hydraulic oil and effectively inhibiting the increase in viscosity and precipitates in the hydraulic oil. At the same time, in the antioxidant composition, the content of the diphenylamine antioxidant is less, which is beneficial to reducing the cost of the antioxidant composition and improving the environmental performance of the antioxidant composition.

[0019] Preferably, the thio hindered phenolic antioxidant is a thio symmetric hindered phenolic antioxidant.

[0020] By adopting the above technical solution, due to the large steric hindrance of the thio symmetric hindered phenolic antioxidant, it can protect the phenolic hydroxyl group from being oxidized and consumed, which is beneficial to prolonging the antioxidant effect of the antioxidant composition in the hydraulic oil, further increasing the oxidation induction period of the hydraulic oil, and slowing down the increase in viscosity of the hydraulic oil.

[0021] Preferably, the thio-symmetrical hindered phenol antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol) or 2,2'-thiobis(4-methyl-6-tert-butylphenol) or 4,4'-thiobis(6-tert-butyl-2-methylphenol).

[0022] By adopting the above technical solution, in the thio-symmetrical hindered phenol antioxidant, the ortho-side groups of the phenolic hydroxyl group contain a tert-butyl group and a methyl group with an electron-donating effect, which can improve the proton-donating ability of the phenolic hydroxyl group, enhance the activity of the thio-symmetrical hindered phenol antioxidant, and is beneficial to improving the antioxidant efficiency of the antioxidant composition.

[0023] Preferably, the thiocarbamate is dialkyldithiocarbamate or dibutyldithiocarbamate.

[0024] By adopting the above technical solution, dialkyldithiocarbamate or dibutyldithiocarbamate has a good synergistic effect with thio-hindered phenol antioxidants and diphenylamine antioxidants, which is beneficial to improving the efficiency of the antioxidant composition in scavenging free radicals and decomposing hydroperoxides, prolonging the oxidation induction period of hydraulic oil, and inhibiting the viscosity increase of hydraulic oil.

[0025] Preferably, the diphenylamine antioxidant is octyl / butyl diphenylamine, sulfurized diphenylamine or alkyl diphenylamine.

[0026] By adopting the above technical solution, the above-mentioned types of diphenylamine antioxidants have good heat resistance and free radical scavenging ability. The antioxidant composition can exhibit better antioxidant effects in high-temperature environments, improve the antioxidant performance of hydraulic oil, and inhibit the increase in viscosity and the formation of precipitates in hydraulic oil. At the same time, sulfurized diphenylamine also has good peroxide decomposition ability, which is beneficial to further improving the antioxidant effect of the antioxidant composition.

[0027] Preferably, the adjustable-viscosity antioxidant composition is composed of a thio-hindered phenol antioxidant, a thiocarbamate and a diphenylamine antioxidant in a weight ratio of 1:(0.34 - 0.63):(0.31 - 0.75).

[0028] By adopting the above technical solution, when the thio-hindered phenol antioxidant, the thiocarbamate and the diphenylamine antioxidant are compounded in the above weight ratio, the obtained antioxidant composition has higher free radical scavenging efficiency and hydroperoxide decomposition efficiency. Adding the antioxidant composition to hydraulic oil is beneficial to increasing the oxidation induction period of hydraulic oil, alleviating the increase in hydraulic oil viscosity, and the formation of precipitates.

[0029] In summary, the present application has the following beneficial effects:

[0030] 1. The antioxidant composition obtained by compounding a sulfur-containing hindered phenol antioxidant and a thiocarbamate not only has good free radical scavenging ability and hydroperoxide decomposition ability, but also the sulfur-containing hindered phenol antioxidant that gives protons to free radicals can form hydrogen bonds with the thiocarbamate, improving the stability of the sulfur-containing hindered phenol antioxidant that gives protons to free radicals, further promoting the decomposition of hydroperoxides, being beneficial to increasing the oxidation induction period of hydraulic oil, and effectively inhibiting the increase in viscosity in hydraulic oil;

[0031] 2. The compounding of a sulfur-containing hindered phenol antioxidant, a thiocarbamate and a diphenylamine antioxidant can not only improve the free radical scavenging efficiency and hydroperoxide decomposition efficiency of the antioxidant composition, increase the oxidation induction period of hydraulic oil, and inhibit the increase in viscosity and the formation of precipitates in hydraulic oil. Detailed implementation mode

[0032] The following further elaborates on this application in conjunction with examples.

[0033] Performance detection

[0034] Configuration of the sample to be tested: Add the adjustable viscosity antioxidant composition obtained in the examples of this application or the antioxidant composition obtained in the comparative examples to the 250SN 46# hydraulic oil base oil (purchased from Shandong Zhuyou Lubrication Technology Co., Ltd.), and after stirring and mixing, hydraulic oil is obtained.

[0035] Detection of the oxidation induction period, oxidation stability, kinematic viscosity (at 40 °C, mm 2 / s) change rate and precipitates of hydraulic oil: Detection of the oxidation stability of hydraulic oil - Rotating Bomb Oxidation Test (RPVOT): Use the standard test method of SH / T 0193 - 2008, and select the test temperature of 150 °C.

[0036] Detection of the oxidation induction period of hydraulic oil - Pressure Differential Scanning Calorimetry (PDSC): Use the standard test method of SH / T0719 - 2002, select the test temperature of 210 °C, and the pressure of 3.5 MPa.

[0037] Detection of the kinematic viscosity (at 40 °C, mm 2 / s) change rate of hydraulic oil: Refer to ASTM D4636 to calculate the kinematic viscosity (at 40 °C, mm 2 / s) change rate of hydraulic oil after 72 h at 175 °C.

[0038] Detection of precipitates in hydraulic oil: Refer to SH / T 0811 - 2010.

[0039] Examples

[0040] Example 1

[0041] An antioxidant composition with adjustable viscosity, and its components and weights are shown in the following table:

[0042]

[0043] The preparation method of the above antioxidant composition with adjustable viscosity is: stir and mix a thiohindered phenol antioxidant, a thiocarbamate, and a diphenylamine antioxidant to obtain the antioxidant composition with adjustable viscosity.

[0044] Examples 2 - 6

[0045] An antioxidant composition with adjustable viscosity, which is different from Example 1 in that its components and weights are shown in the following table:

[0046]

[0047] For the antioxidant compositions with adjustable viscosity obtained in Examples 1 - 6 of this application, the oxidation induction period, oxidation stability, and the change rate of kinematic viscosity (40 °C, mm 2 / s) were detected, and the detection results are shown in the following table:

[0048]

[0049] By analyzing the data in the above table, it can be seen that for the antioxidant compositions with adjustable viscosity obtained in Examples 1 - 5, compared with the antioxidant composition with adjustable viscosity obtained in Example 6, the oxidation induction period is longer, the oxidation stability is greater, and the change rate of kinematic viscosity is smaller. This shows that in the total raw materials for preparing the antioxidant composition with adjustable viscosity in this application, adding a diphenylamine antioxidant can improve the antioxidant efficiency of the antioxidant composition with adjustable viscosity and reduce the change rate of the viscosity of the hydraulic oil after oxidation.

[0050] By comparing the antioxidant compositions with adjustable viscosity in Examples 1 - 3 with those in Examples 4 - 5, it can be seen that for the antioxidant compositions with adjustable viscosity obtained in Examples 1 - 3, compared with the antioxidant compositions with adjustable viscosity obtained in Examples 4 - 5, the oxidation induction period is longer, the oxidation stability is greater, and the change rate of kinematic viscosity is smaller. This shows that in the total raw materials for preparing the antioxidant composition with adjustable viscosity in this application, the antioxidant composition with adjustable viscosity is composed of a thiohindered phenol antioxidant, a thiocarbamate, and a diphenylamine antioxidant mixed in a weight ratio of 1:(0.34 - 0.63):(0.31 - 0.75), which can improve the antioxidant efficiency of the antioxidant composition and effectively inhibit the increase in the viscosity of the hydraulic oil after oxidation.

[0051] In particular, for the antioxidant composition with adjustable viscosity obtained in Example 1, compared with the antioxidant compositions with adjustable viscosity obtained in Examples 2-3, the oxidation induction period increased relatively by -2.71 - 4.58%, the oxidation stability increased relatively by -29.4 - 5.77%, and the change rate of kinematic viscosity decreased relatively by -8.82 - 11.20%. This indicates that among the total raw materials for preparing the antioxidant composition with adjustable viscosity in this application, the antioxidant composition obtained by mixing 4,4'-thiobis(6-tert-butyl-2-methylphenol), dialkyldithiocarbamate, and diphenylamine sulfide in a weight ratio of 1:0.46:0.5 has excellent antioxidant performance, can improve the antioxidant property of hydraulic oil, and reduce the change rate of the viscosity of hydraulic oil after oxidation.

[0052] Example 7

[0053] An antioxidant composition with adjustable viscosity, which is different from that in Example 1 in that 4,4'-thiobis(6-tert-butyl-3-methylphenol) of equal weight is used to replace 4,4'-thiobis(6-tert-butyl-2-methylphenol).

[0054] Example 8

[0055] An antioxidant composition with adjustable viscosity, which is different from that in Example 1 in that 2,2'-thiobis(4-methyl-6-tert-butylphenol) of equal weight is used to replace 4,4'-thiobis(6-tert-butyl-2-methylphenol).

[0056] Example 9

[0057] An antioxidant composition with adjustable viscosity, which is different from that in Example 1 in that the thiohindered phenol antioxidant is composed of 4,4'-thiobis(6-tert-butyl-3-methylphenol) and 4,4'-thiobis(6-tert-butyl-2-methylphenol) mixed in a weight ratio of 1:1.

[0058] Example 10

[0059] An antioxidant composition with adjustable viscosity, which is different from that in Example 1 in that 2,4-bis(n-octylthiomethylene)-6-methylphenol of equal weight is used to replace 4,4'-thiobis(6-tert-butyl-2-methylphenol).

[0060] For the antioxidant compositions with adjustable viscosity obtained in Examples 7-10 of this application, the oxidation induction period, oxidation stability, and change rate of kinematic viscosity (40 °C, mm 2 / s) were detected, and the detection results are shown in the following table:

[0061]

[0062] By analyzing the data in the above table, it can be seen that for the adjustable-viscosity antioxidant compositions of Examples 1, 7, and 8, the oxidation induction period is as high as 2200 - 2510 min, the oxidation stability is as high as 14.4 - 16.5 min, and the change rate of kinematic viscosity is as low as 1.11 - 1.35%.

[0063] Comparing the adjustable-viscosity antioxidant compositions of Examples 1, 7, and 8 with the adjustable-viscosity antioxidant composition of Example 9, it can be seen that the adjustable-viscosity antioxidant compositions of Examples 1, 7, and 8 have a longer oxidation induction period, greater oxidation stability, and a smaller change rate of kinematic viscosity compared to the adjustable-viscosity antioxidant composition of Example 9. This shows that in the total raw materials for preparing the adjustable-viscosity antioxidant composition of this application, the thio hindered phenol antioxidant is a thio-symmetric hindered phenol antioxidant, which can improve the antioxidant efficiency of the adjustable-viscosity antioxidant composition and reduce the change rate of the viscosity of the hydraulic oil after oxidation.

[0064] Comparing the adjustable-viscosity antioxidant compositions of Examples 1, 7, and 8 with the adjustable-viscosity antioxidant composition of Example 10, it can be seen that the adjustable-viscosity antioxidant compositions of Examples 1, 7, and 8 have a longer oxidation induction period, greater oxidation stability, and a smaller change rate of kinematic viscosity compared to the adjustable-viscosity antioxidant composition of Example 10. This shows that in the total raw materials for preparing the adjustable-viscosity antioxidant composition of this application, the thio-symmetric hindered phenol antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol) or 2,2'-thiobis(4-methyl-6-tert-butylphenol) or 4,4'-thiobis(6-tert-butyl-2-methylphenol), and the obtained adjustable-viscosity antioxidant composition has good antioxidant efficiency and reduces the change rate of the viscosity of the hydraulic oil after oxidation.

[0065] Example 11

[0066] An adjustable-viscosity antioxidant composition, which is different from that of Example 1 in that dibutyl dithiocarbamate is used to replace dialkyl dithiocarbamate in equal weight.

[0067] For the adjustable-viscosity antioxidant composition obtained in Example 11 of this application, tests were carried out on the oxidation induction period, oxidation stability, and change rate of kinematic viscosity (40 °C, mm 2 / s), and the test results are shown in the following table:

[0068]

[0069]

[0070] By analyzing the data in the above table, it can be seen that for the adjustable-viscosity antioxidant composition obtained in Example 1, compared with the adjustable-viscosity antioxidant composition obtained in Example 11, the oxidation induction period increased by 9.37% relatively, the oxidation stability increased by 10.74% relatively, and the change rate of kinematic viscosity decreased by 15.27% relatively. This shows that among the total raw materials for preparing the adjustable-viscosity antioxidant composition in this application, the thiocarbamate is dialkyldithiocarbamate, which can improve the antioxidant property of hydraulic oil and effectively inhibit the increase in the viscosity of hydraulic oil after oxidation.

[0071] Example 12

[0072] An adjustable-viscosity antioxidant composition, which is different from that of Example 1 in that octyl / butyl diphenylamine of equal weight is used to replace sulfurized diphenylamine.

[0073] Example 13

[0074] An adjustable-viscosity antioxidant composition, which is different from that of Example 1 in that alkyl diphenylamine of equal weight is used to replace sulfurized diphenylamine.

[0075] Example 14

[0076] An adjustable-viscosity antioxidant composition, which is different from that of Example 1 in that N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine of equal weight is used to replace sulfurized diphenylamine.

[0077] For the adjustable-viscosity antioxidant compositions obtained in Examples 12 - 14 of this application, the oxidation induction period, oxidation stability and change rate of kinematic viscosity (40 °C, mm 2 / s) were detected, and the detection results are shown in the following table:

[0078]

[0079] By analyzing the data in the above table, it can be seen that for the adjustable-viscosity antioxidant composition obtained in Example 1, compared with the adjustable-viscosity antioxidant composition obtained in Example 12, the oxidation induction period increased by 10.62% relatively, the oxidation stability increased by 11.49% relatively, and the change rate of kinematic viscosity decreased by 15.91% relatively.

[0080] For the adjustable-viscosity antioxidant composition obtained in Example 1, compared with the adjustable-viscosity antioxidant composition obtained in Example 13, the oxidation induction period increased by 13.06% relatively, the oxidation stability increased by 12.24% relatively, and the change rate of kinematic viscosity decreased by 17.16% relatively.

[0081] This indicates that among the total raw materials for preparing the antioxidant composition with adjustable viscosity in the present application, the diphenylamine antioxidant is octyl / butyl diphenylamine, sulfurized diphenylamine or alkyl diphenylamine, especially sulfurized diphenylamine. The obtained antioxidant composition with adjustable viscosity has higher antioxidant properties and can effectively inhibit the increase in the viscosity of hydraulic oil after oxidation.

[0082] The antioxidant composition with adjustable viscosity obtained in Example 1, compared with the antioxidant composition with adjustable viscosity obtained in Example 13, has a relative increase of 16.47% in the oxidation induction period, a relative increase of 16.20% in the oxidation stability, and a relative decrease of 22.92% in the kinematic viscosity change rate. This indicates that in the total raw materials for preparing the antioxidant composition with adjustable viscosity in the present application, the use of a combination of diphenylamine antioxidants, thiohindered phenol antioxidants, and thiocarbamate can improve the antioxidant properties of hydraulic oil and effectively inhibit the increase in the viscosity of hydraulic oil after oxidation.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] An antioxidant composition, which is different from that in Example 1 in that 2,2'-methylenebis(4-methyl-6-tert-butylphenol) of equal weight is used to replace the thiohindered phenol antioxidant.

[0086] Comparative Example 2

[0087] An antioxidant composition, which is different from that in Example 1 in that dilauryl thiodipropionate of equal weight is used to replace the thiocarbamate.

[0088] For the antioxidant compositions obtained in Comparative Examples 1-2 of the present application, the oxidation induction period, oxidation stability, and kinematic viscosity (40 °C, mm 2 / s) change rate were detected, and the detection results are shown in the following table:

[0089]

[0090] By analyzing the data in the above table, it can be seen that the antioxidant composition with adjustable viscosity obtained in Example 1, compared with the antioxidant composition obtained in Comparative Example 1, has a relative increase of 61.49% in the oxidation induction period, a relative increase of 63.20% in the oxidation stability, and a relative decrease of 81.38% in the kinematic viscosity change rate.

[0091] The antioxidant composition with adjustable viscosity obtained in Example 1, compared with the antioxidant composition obtained in Comparative Example 2, has a relative increase of 45.93% in the oxidation induction period, a relative increase of 46.67% in the oxidation stability, and a relative decrease of 61.05% in the kinematic viscosity change rate.

[0092] This indicates that in the total raw materials for preparing the antioxidant composition with adjustable viscosity in the present application, the compounding of thio hindered phenol antioxidants and thiocarbamates can improve the antioxidant property of the obtained antioxidant composition and effectively inhibit the increase in the viscosity of hydraulic oil.

[0093] The post-oxidation precipitate detection was carried out on the antioxidant compositions with adjustable viscosity obtained in Examples 1-14 of the present application and the antioxidant compositions obtained in Comparative Examples 1-2. The detection results showed that the post-oxidation precipitate content of Examples 1-14 was ≤ 0.01%, and the post-oxidation precipitate content of Comparative Examples 1-2 was 0.05 - 0.08%. This indicates that the antioxidant composition with adjustable viscosity obtained in the present application can effectively inhibit the formation of post-oxidation precipitates in hydraulic oil.

[0094] This specific embodiment is only an interpretation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications without creative contributions to this 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. An antioxidant composition with adjustable viscosity, characterized in that, Comprising the following components in parts by weight: Thioblock phenolic antioxidant: 10 - 20 parts; Thiocarbamate: 5 - 8 parts; Diphenylamine antioxidant: 5 - 10 parts; The thioblock phenolic antioxidant is a thiosymmetric blocked phenolic antioxidant; The diphenylamine antioxidant is sulfurized diphenylamine or alkyl diphenylamine.

2. The antioxidant composition with adjustable viscosity according to claim 1, characterized in that: The thiosymmetric blocked phenolic antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol) or 2,2'-thiobis(4-methyl-6-tert-butylphenol) or 4,4'-thiobis(6-tert-butyl-2-methylphenol).

3. The antioxidant composition with adjustable viscosity according to claim 1, wherein: The thiocarbamate is dialkyldithiocarbamate.

4. The antioxidant composition with adjustable viscosity according to claim 1, characterized in that: The thioblock phenolic antioxidant, thiocarbamate and diphenylamine antioxidant are mixed in a weight ratio of 1:(0.34 - 0.63):(0.31 - 0.75).

Images