Antioxidant corrosion-resistant lubricating oil and preparation method thereof

Abstract

The invention discloses antioxidant corrosion-resistant lubricating oil and a preparation method thereof, and relates to the technical field of corrosion-resistant lubricating oil. Firstly, N-(1-naphthyl) ethylenediamine and isocyanate are used for generating a high-temperature-resistant corrosion inhibitor, the high-temperature-resistant corrosion inhibitor covers the surface of metal to form a protective film, corrosion of the lubricating oil to the metal is slowed down, the oxidation resistance of the lubricating oil under high-temperature, high-pressure and high-humidity industrial and mining conditions is improved, then 1, 2, 4-thiadiazole-5-formic acid and 2, 3, 4-trihydroxybenzoic acid are used for dehydration esterification, and the corrosion resistance of the lubricating oil is improved. Phenolic hydroxyl groups and carboxyl groups which are not reacted in the structure can efficiently capture free radicals and improve the oxidation resistance of lubricating oil, and thiadiazole groups can react with metal ions to form metal ion chelates on the metal surface, so that the metal is prevented from forming oxidation catalysis on the lubricating oil, and the anti-oxidation effect is further achieved. The oxidation resistance and corrosion resistance of the lubricating oil are effectively improved on the basis that the high-temperature lubricating performance is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion-resistant lubricating oil, in particular to an oxidation-resistant and corrosion-resistant lubricating oil and a preparation method thereof. Background Art

[0002] The main function of lubricating oil is to reduce friction and wear between mechanical parts. It also has cooling, rust prevention, cleaning, sealing and buffering functions. In some high-temperature working conditions, in addition to the basic functions of ordinary lubricating oil, lubricating oil must also meet the requirements of stability and corrosion resistance in high-temperature environments to ensure the normal operation of mechanical equipment under extreme conditions, such as aircraft engines, automobile engines, industrial furnaces, drying equipment, high-temperature bearings, etc. In these fields, lubricating oil needs to provide long-lasting and effective lubrication protection to reduce equipment wear, extend service life and improve work efficiency. The performance of traditional mineral oil is limited at high temperatures. High temperatures will accelerate the oxidation process of lubricating oil, causing it to deteriorate and fail, and even face erosion by corrosive media, such as acids, alkalis, salts, etc., which greatly affect the normal operation of mechanical parts under high-temperature working conditions. These working conditions require the addition of appropriate additives to lubricating oil to form a protective layer on the metal surface, isolate corrosive media, prevent metal parts from rusting and corrosion, and protect the lubricating oil to reduce the oxidation failure of the lubricating oil in high-temperature environments. Summary of the invention

[0003] The purpose of the present invention is to provide an anti-oxidation and non-corrosive lubricating oil and a preparation method thereof, so as to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: an antioxidant and non-corrosive lubricating oil, which comprises a base oil, a high temperature resistant corrosion inhibitor, a high efficiency antioxidant, an extreme pressure anti-wear agent, and a viscosity index improver.

[0005] Furthermore, the base oil is one or more of mineral-based base oil, ester-based base oil, and polyether base oil, and has a viscosity index of 85-100.

[0006] Furthermore, the high temperature resistant anti-corrosion agent is prepared by reacting N-(1-naphthyl)ethylenediamine with isocyanate.

[0007] Furthermore, the high-efficiency antioxidant is prepared by dehydration esterification of 1,2,4-thiadiazole-5-carboxylic acid and 2,3,4-trihydroxybenzoic acid.

[0008] Furthermore, the extreme pressure anti-wear agent is one or two of boric acid esters and boric acid salts, and the viscosity index improver is one or two of ethylene propylene copolymer, polyisobutylene, and hydrogenated styrene copolymer.

[0009] Furthermore, a method for preparing an anti-oxidation and non-corrosive lubricating oil comprises the following preparation steps:

[0010] (1) dissolving N-(1-naphthyl)ethylenediamine in tetrahydrofuran to obtain solution A, dissolving isocyanate in tetrahydrofuran to obtain solution B, adding solution A and solution B dropwise at a rate of 1 to 2 drops / s under an argon atmosphere, stirring to react after all are mixed, centrifuging at a rate of 8000 to 12000 r / min after completion, filtering with suction, washing with tetrahydrofuran for 3 to 6 times, and drying in an oven at 50 to 70° C. for 4 to 6 hours to obtain a high temperature resistant corrosion inhibitor;

[0011] (2) Add 1,2,4-thiadiazole-5-carboxylic acid, 2,3,4-trihydroxybenzoic acid, and tetrabutylammonium bromide to toluene, stir and heat to 70-90° C., add 3% sodium hydroxide solution at a rate of 0.5-1 drop / s, stir for 6-8 hours, wait until the temperature reaches room temperature, add deionized water, let stand for 30-50 minutes, separate the organic layer, wash the organic layer with deionized water 3-6 times until the pH is 6.6-7.5, and evaporate the solvent to obtain a high-efficiency antioxidant;

[0012] (3) The base oil is heated to 140-160° C., and a high temperature corrosion resistant agent, a high efficiency antioxidant, an extreme pressure anti-wear agent, and a viscosity index improver are added in sequence while stirring at a speed of 700-1000 r / min. After stirring for 1-2 hours, the mixture is cooled to room temperature to obtain an oxidation-resistant and corrosion-resistant lubricating oil.

[0013] Furthermore, in the step (1), after the solution A and the solution B are mixed, they are stirred at a rate of 600 to 800 r / min for 20 to 30 hours at room temperature.

[0014] Furthermore, in step (1), by weight, solution A contains 30 to 50 parts of N-(1-naphthyl)ethylenediamine and 60 to 70 parts of tetrahydrofuran, and solution B contains 45 to 55 parts of isocyanate and 60 to 70 parts of tetrahydrofuran.

[0015] Furthermore, in step (2), by weight, 40 to 50 parts of 1,2,4-thiadiazole-5-carboxylic acid, 50 to 60 parts of 2,3,4-trihydroxybenzoic acid, 5 to 10 parts of tetrabutylammonium bromide, 60 to 80 parts of toluene, and 20 to 30 parts of 3% sodium hydroxide solution are added.

[0016] Furthermore, in step (3), the base oil is 50 to 80 parts, the high temperature corrosion resistant agent is 5 to 10 parts, the high efficiency antioxidant is 5 to 10 parts, the extreme pressure anti-wear agent is 10 to 20 parts, and the viscosity index improver is 10 to 20 parts, by weight.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] The oxidation-resistant and corrosion-resistant lubricating oil prepared by the invention effectively improves the oxidation resistance and corrosion resistance of the lubricating oil on the basis of achieving high-temperature lubricating performance.

[0019] First, N-(1-naphthyl)ethylenediamine and isocyanate are used to generate a high-temperature resistant corrosion inhibitor. Urea bonds are introduced into the structure of the corrosion inhibitor, which covers the metal surface to form a protective film to prevent corrosive substances from contacting the metal and causing damage to the metal. The hydrogen atoms on the amine group in the structure can react with the free radicals generated during the oxidation process of the lubricating oil, thereby terminating the free radical chain reaction during the oxidation process and showing a certain degree of antioxidant properties. The naphthyl structure has a high stability, so that the generated oxidant can still maintain stability in harsh environments such as high temperature, high pressure and high humidity, and can maintain its own corrosion resistance and antioxidant properties for a long time, thereby extending the service life of the lubricating oil.

[0020] Secondly, 1,2,4-thiadiazole-5-carboxylic acid and 2,3,4-trihydroxybenzoic acid are dehydrated and esterified to obtain a high-efficiency antioxidant. The unreacted phenolic hydroxyl and carboxyl groups in the structure can effectively capture free radicals caused by high temperature, oxidation, ultraviolet light, light and other reasons in the lubricating oil. When the free radicals are initially formed, they react with them to convert them into relatively stable compounds, and no longer react with other hydrocarbon molecules or oxygen, thereby cutting off the oil oxidation reaction chain and delaying the oxidation process. The thiadiazole group introduced in the antioxidant can react with metal ions to form a metal ion chelate on the metal surface to form a protective isolation film to prevent the metal from forming an oxidation catalysis on the lubricating oil, further improving the antioxidant effect of the antioxidant. The generated high-efficiency antioxidant has higher antioxidant activity than the high-temperature corrosion resistant agent. During the storage at room temperature, the high-efficiency antioxidant first exerts its antioxidant performance. When encountering special working conditions of high temperature, high pressure and high humidity, the high-temperature corrosion resistant agent exerts its antioxidant performance. The two complement each other and significantly improve the antioxidant and corrosion resistance of the lubricating oil. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the anti-oxidation and non-corrosive lubricating oil prepared in the following examples are as follows:

[0023] Kinematic viscosity: The kinematic viscosity of the anti-oxidation and non-corrosive lubricating oils prepared in Examples 1-3 and Comparative Examples 1-9 at 100°C was tested according to GB / T265;

[0024] Anti-wear property: After heat treatment at 150° C. for 8 hours, the anti-oxidation and non-corrosive lubricating oils prepared in Examples 1-3 and Comparative Examples 1-9 were subjected to anti-wear property test according to GB / T3142;

[0025] Corrosion resistance: After heat treatment at 150°C for 8 hours, the oxidation-resistant and non-corrosive lubricating oils prepared in Examples 1-3 and Comparative Examples 1-9 were tested for corrosion resistance according to GB / T5096.

[0026] Example 1

[0027] (1) dissolving 30 parts of N-(1-naphthyl)ethylenediamine in 60 parts of tetrahydrofuran to obtain solution A, dissolving 45 parts of isocyanate in 60 parts of tetrahydrofuran to obtain solution B, adding solution A and solution B dropwise at a rate of 1 drop / s under an argon atmosphere, stirring to react after all are mixed, centrifuging at a rate of 12000 r / min after completion, filtering with suction, washing with tetrahydrofuran 6 times, and drying in an oven at 65° C. for 5 h to obtain a high temperature resistant corrosion inhibitor;

[0028] (2) Add 40 parts of 1,2,4-thiadiazole-5-carboxylic acid, 50 parts of 2,3,4-trihydroxybenzoic acid, and 5 parts of tetrabutylammonium bromide to 60 parts of toluene, stir and heat to 80°C, add 20 parts of 3% sodium hydroxide solution at a rate of 0.5 drops / s, stir for 7 hours, add deionized water when the temperature reaches room temperature, let stand for 50 minutes, separate the organic layer, wash the organic layer with deionized water 5 times to a pH of 7.2, and evaporate the solvent to obtain a high-efficiency antioxidant;

[0029] (3) Heat 50 parts of base oil to 145°C, add 5 parts of high temperature corrosion resistant agent, 5 parts of high efficiency antioxidant, 10 parts of extreme pressure anti-wear agent, and 10 parts of viscosity index improver in sequence while stirring at a speed of 1000 r / min, stir for 2 hours, and cool to room temperature to obtain an antioxidant and non-corrosive lubricating oil.

[0030] Example 2

[0031] (1) dissolving 40 parts of N-(1-naphthyl)ethylenediamine in 65 parts of tetrahydrofuran to obtain solution A, dissolving 50 parts of isocyanate in 65 parts of tetrahydrofuran to obtain solution B, adding solution A and solution B dropwise at a rate of 1 drop / s under an argon atmosphere, stirring to react after all are mixed, centrifuging at a rate of 12000 r / min after completion, filtering with suction, washing with tetrahydrofuran 6 times, and drying in an oven at 65° C. for 5 h to obtain a high temperature resistant corrosion inhibitor;

[0032] (2) Add 45 parts of 1,2,4-thiadiazole-5-carboxylic acid, 55 parts of 2,3,4-trihydroxybenzoic acid, and 8 parts of tetrabutylammonium bromide to 70 parts of toluene, stir and heat to 80°C, add 25 parts of 3% sodium hydroxide solution at a rate of 0.5 drops / s, stir for 7 hours, wait until the temperature reaches room temperature, add deionized water, let stand for 50 minutes, separate the organic layer, wash the organic layer with deionized water 5 times to a pH of 7.2, and evaporate the solvent to obtain a high-efficiency antioxidant;

[0033] (3) Heat 70 parts of base oil to 145°C, add 8 parts of high temperature corrosion resistant agent, 8 parts of high efficiency antioxidant, 15 parts of extreme pressure anti-wear agent, and 15 parts of viscosity index improver in sequence while stirring at a speed of 1000 r / min, stir for 2 hours, and cool to room temperature to obtain an antioxidant and non-corrosive lubricating oil.

[0034] Example 3

[0035] (1) dissolving 50 parts of N-(1-naphthyl)ethylenediamine in 70 parts of tetrahydrofuran to obtain solution A, dissolving 55 parts of isocyanate in 70 parts of tetrahydrofuran to obtain solution B, adding solution A and solution B dropwise at a rate of 1 drop / s under an argon atmosphere, stirring to react after all are mixed, centrifuging at a rate of 12000 r / min after completion, filtering with suction, washing with tetrahydrofuran 6 times, and drying in an oven at 65° C. for 5 h to obtain a high temperature resistant corrosion inhibitor;

[0036] (2) Add 50 parts of 1,2,4-thiadiazole-5-carboxylic acid, 60 parts of 2,3,4-trihydroxybenzoic acid, and 10 parts of tetrabutylammonium bromide to 80 parts of toluene, stir and heat to 80°C, add 30 parts of 3% sodium hydroxide solution at a rate of 0.5 drops / s, stir for 7 hours, add deionized water when the temperature reaches room temperature, let stand for 50 minutes, separate the organic layer, wash the organic layer with deionized water 5 times to a pH of 7.2, and evaporate the solvent to obtain a high-efficiency antioxidant;

[0037] (3) 80 parts of base oil are heated to 145°C, and 10 parts of high temperature corrosion resistant agent, 10 parts of high efficiency antioxidant, 20 parts of extreme pressure anti-wear agent, and 20 parts of viscosity index improver are added in sequence while stirring at a speed of 1000 r / min. After stirring for 2 hours, the mixture is cooled to room temperature to obtain an antioxidant and non-corrosive lubricating oil.

[0038] Comparative Example 1

[0039] The difference between Comparative Example 1 and Example 2 is that step (1) is removed, no high temperature resistant anti-corrosion agent is added in step (3), and the remaining steps are the same as Example 2.

[0040] Comparative Example 2

[0041] The difference between Comparative Example 2 and Example 2 is that step (2) is removed, no high-efficiency antioxidant is added in step (3), and the remaining steps are the same as Example 2.

[0042] Comparative Example 3

[0043] The difference between Comparative Example 3 and Example 2 is that step (1) and step (2) are removed, high temperature corrosion resistant anti-corrosion agent and high efficiency antioxidant are not added in step (3), and the remaining steps are the same as Example 2.

[0044] Comparative Example 4

[0045] The difference between Comparative Example 4 and Example 2 is that N-(1-naphthyl)ethylenediamine in step (1) is replaced by ethylenediamine, and the remaining steps are the same as Example 2.

[0046] Comparative Example 5

[0047] The difference between Comparative Example 5 and Example 2 is that 1,2,4-thiadiazole-5-carboxylic acid in step (2) is replaced by formic acid, and the remaining steps are the same as Example 2.

[0048] Comparative Example 6

[0049] The difference between Comparative Example 6 and Example 2 is that step (1) is omitted, and in step (3) only N-(1-naphthyl)ethylenediamine is used as a high temperature resistant anti-corrosion agent, and the remaining steps are the same as Example 2.

[0050] Comparative Example 7

[0051] The difference between Comparative Example 7 and Example 2 is that step (1) is omitted, and in step (3) only isocyanate is used as a high temperature resistant anti-corrosion agent, and the remaining steps are the same as Example 2.

[0052] Comparative Example 8

[0053] The difference between Comparative Example 8 and Example 2 is that step (2) is omitted, and in step (3), only 1,2,4-thiadiazole-5-carboxylic acid is used as a high-efficiency antioxidant, and the remaining steps are the same as in Example 2.

[0054] Comparative Example 9

[0055] The difference between Comparative Example 9 and Example 2 is that step (2) is omitted, and in step (3), only 2,3,4-trihydroxybenzoic acid is used as a high-efficiency antioxidant, and the remaining steps are the same as in Example 2.

[0056] Effect example

[0057] Table 1 below shows the performance analysis results of the anti-oxidation and non-corrosive lubricating oils of Examples 1 to 3 of the present invention and Comparative Examples 1 to 9.

[0058] Table 1 Performance test results of the anti-oxidation and non-corrosive lubricating oils of Examples 1 to 3 and Comparative Examples 1 to 9

[0059]

[0060] It can be seen from the results in the table that the antioxidant and non-corrosive lubricating oil prepared in the present application has good viscosity at 100°C and exhibits good lubrication performance. The prepared high-temperature resistant corrosion inhibitor has improved high-temperature performance of the lubricating oil due to the introduction of naphthyl groups in the structure. The prepared high-efficiency antioxidant has improved corrosion resistance of the lubricating oil due to the presence of thiadiazole groups, reduced corrosion of the lubricating oil to copper sheets, and enhanced oxidation resistance of the lubricating oil.

[0061] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An anti-oxidation and non-corrosive lubricating oil, characterized in that: The anti-oxidation and non-corrosive lubricating oil comprises base oil, high temperature resistant anti-corrosion agent, high efficiency antioxidant, extreme pressure anti-wear agent and viscosity index improver.

2. The anti-oxidation and non-corrosive lubricating oil according to claim 1, characterized in that: The base oil is one or more of mineral-based base oil, ester-based base oil and polyether base oil, and the viscosity index is 85-100.

3. The anti-oxidation and non-corrosive lubricating oil according to claim 2, characterized in that: The high temperature resistant anti-corrosion agent is prepared by the reaction of N-(1-naphthyl)ethylenediamine and isocyanate.

4. The anti-oxidation and non-corrosive lubricating oil according to claim 3, characterized in that: The high-efficiency antioxidant is prepared by dehydration esterification of 1,2,4-thiadiazole-5-carboxylic acid and 2,3,4-trihydroxybenzoic acid.

5. The anti-oxidation and non-corrosive lubricating oil according to claim 4, characterized in that: The extreme pressure anti-wear agent is one or two of boric acid ester and boric acid salt, and the viscosity index improver is one or two of ethylene propylene copolymer, polyisobutylene and hydrogenated styrene copolymer.

6. A method for preparing an oxidation-resistant and non-corrosive lubricating oil, characterized in that: The method comprises the following preparation steps: (1) dissolving N-(1-naphthyl)ethylenediamine in tetrahydrofuran to obtain solution A, dissolving isocyanate in tetrahydrofuran to obtain solution B, adding solution A and solution B dropwise at a rate of 1 to 2 drops / s under an argon atmosphere, stirring to react after all are mixed, centrifuging at a rate of 8000 to 12000 r / min after completion, filtering with suction, washing with tetrahydrofuran for 3 to 6 times, and drying in an oven at 50 to 70° C. for 4 to 6 hours to obtain a high temperature resistant corrosion inhibitor; (2) Add 1,2,4-thiadiazole-5-carboxylic acid, 2,3,4-trihydroxybenzoic acid, and tetrabutylammonium bromide to toluene, stir and heat to 70-90° C., add 3% sodium hydroxide solution at a rate of 0.5-1 drop / s, stir for 6-8 hours, wait until the temperature reaches room temperature, add deionized water, let stand for 30-50 minutes, separate the organic layer, wash the organic layer with deionized water 3-6 times until the pH is 6.6-7.5, and evaporate the solvent to obtain a high-efficiency antioxidant; (3) The base oil is heated to 140-160° C., and a high temperature corrosion resistant agent, a high efficiency antioxidant, an extreme pressure anti-wear agent, and a viscosity index improver are added in sequence while stirring at a speed of 700-1000 r / min. After stirring for 1-2 hours, the mixture is cooled to room temperature to obtain an oxidation-resistant and corrosion-resistant lubricating oil.

7. The method for preparing an oxidation-resistant and corrosion-resistant lubricating oil according to claim 6, characterized in that: In the step (1), after the solution A and the solution B are mixed, they are stirred at a rate of 600 to 800 r / min for 20 to 30 hours at room temperature.

8. The method for preparing an oxidation-resistant and corrosion-resistant lubricating oil according to claim 6, characterized in that: In step (1), by weight, solution A contains 30 to 50 parts of N-(1-naphthyl)ethylenediamine and 60 to 70 parts of tetrahydrofuran, and solution B contains 45 to 55 parts of isocyanate and 60 to 70 parts of tetrahydrofuran.

9. The method for preparing an oxidation-resistant and corrosion-resistant lubricating oil according to claim 6, characterized in that: In step (2), the following are added by weight: 40-50 parts of 1,2,4-thiadiazole-5-carboxylic acid, 50-60 parts of 2,3,4-trihydroxybenzoic acid, 5-10 parts of tetrabutylammonium bromide, 60-80 parts of toluene, and 20-30 parts of 3% sodium hydroxide solution.

10. The method for preparing an oxidation-resistant and corrosion-resistant lubricating oil according to claim 6, characterized in that: In step (3), the base oil is 50-80 parts, the high temperature corrosion resistant agent is 5-10 parts, the high efficiency antioxidant is 5-10 parts, the extreme pressure anti-wear agent is 10-20 parts, and the viscosity index improver is 10-20 parts, by weight.

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