High-temperature-resistant composite antirust lubricant

Abstract

The invention provides a high-temperature-resistant composite antirust lubricant, and belongs to the technical field of lubricants. The lubricating oil comprises the following components: base oil, a thickening agent, molybdenum disulfide, a sulfonic acid group-quaternary ammonium salt compound and an antioxidant. The glycine-monosaccharide lipid is prepared, the low-foam surfactant and the enzyme catalysis process are combined, the advantages in the aspects of decontamination efficiency, environmental friendliness, material compatibility and the like are achieved, the trend is highly consistent with the trend of low toxicity, low foam and high efficiency in the industry, and the excellent degreasing effect is achieved. According to the invention, a high-temperature-resistant physical framework is constructed through the base oil and the thickening agent; the antioxygen ensures that the framework stably exists at high temperature for a long time; molybdenum disulfide and a sulfonic acid group-quaternary ammonium salt compound act on the friction surface together, protection is provided for the two damage factors of mechanical abrasion and chemical corrosion, and the two damage factors are both emphasized to be still effective at high temperature. According to the invention, the application requirements on high temperature, wear resistance and rust prevention are met.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricants, and in particular relates to a high-temperature resistant composite anti-rust lubricant. Background Art

[0002] High-temperature resistant rust-proof lubricants are specialty chemical products designed for extreme environments, combining lubrication with rust and corrosion protection. They form a dense protective film on metal surfaces, isolating them from moisture, oxygen, and corrosive media (such as acids, alkalis, and salt spray), while also reducing friction and wear between moving parts. Their core properties include:

[0003] High temperature resistance: wide operating temperature range, no decomposition or volatilization at high temperatures, maintaining stability.

[0004] Corrosion resistance: The protective film can resist chemical corrosion and extend the life of metal equipment.

[0005] Low friction coefficient: It can maintain excellent lubricity under high temperature and high pressure environment, reducing energy consumption.

[0006] Oxidation resistance: resists high temperature oxidation reactions and avoids degradation of lubrication performance.

[0007] Conventional lubricants often coke during use. Coking is the formation of solid deposits due to the oxidation and decomposition of lubricating oil at high temperatures or reaction with pollutants in the air. This affects the transmission efficiency of parts and reduces the performance of equipment. Summary of the Invention

[0008] The object of the present invention is to provide a high temperature resistant composite anti-rust lubricant, which comprises the following components in parts by mass:

[0009] A high temperature resistant composite anti-rust lubricant, comprising the following components in parts by mass:

[0010]

[0011] The sulfonic acid group-quaternary ammonium salt complex is prepared by Schiff base reaction of sulfonic acid group aldehyde and tertiary amino group primary amine, followed by alkylation.

[0012] Preferably, the preparation method of the sulfonic acid-quaternary ammonium salt complex comprises the following steps:

[0013] S1: Add sulfonic acid aldehyde to water and dissolve it at 50-60°C, add tertiary amine and primary amine and adjust the pH to 4-6; heat to ≥80°C and reflux for reaction; after the reaction is complete, cool, filter and dry to obtain solid intermediate A;

[0014] S2: Place intermediate A and dimethyl carbonate into a reaction vessel and adjust the pH to 8.0-10.5. Replace the gas in the system with an inert gas; then pressurize to ≥0.5 MPa; stir and heat to at least 160°C; then react for at least 10 hours; during the reaction, pressurize to 2±0.2 MPa; after the reaction is complete, release the pressure, cool, and filter to collect the filtrate;

[0015] S3: Purify the filtrate to obtain intermediate B slurry;

[0016] S4: The intermediate B slurry is dissolved in a solvent, and calcium dinonylnaphthalenesulfonate is added. The temperature is raised to ≥80°C and stirred for reaction for at least 2 hours. The solid matter is removed by filtration, and the mixture is concentrated under reduced pressure and dried to obtain a sulfonic acid-quaternary ammonium salt complex.

[0017] Preferably, in step S1 of the method for preparing the sulfonic acid-quaternary ammonium salt complex, the molar ratio of the sulfonic acid aldehyde to the tertiary amine is 1:1-1.1; and the pH is adjusted using glacial acetic acid.

[0018] Preferably, in step S2 of the method for preparing the sulfonic acid-quaternary ammonium salt complex, the molar ratio of the intermediate A to dimethyl carbonate is 1: at least 3; and the pH is adjusted using potassium carbonate.

[0019] Preferably, step S3 of the method for preparing the sulfonic acid group-quaternary ammonium salt complex is specifically: distilling the filtrate to remove excess dimethyl carbonate; dissolving the residue in hot water and then cooling and crystallizing, centrifuging, and then rinsing to remove impurities.

[0020] Preferably, in step S4 of the method for preparing the sulfonic acid group-quaternary ammonium salt complex, the molar ratio of the intermediate B slurry to calcium nonylnaphthalenesulfonate is 1:1.05-1.1;

[0021] The mass of the solvent is at least 3 times the total mass of the solids.

[0022] Preferably, the sulfonic acid aldehyde is at least one of 3-sodium sulfonate benzaldehyde, 4-sodium sulfonate benzaldehyde, and sodium undecanesulfonate benzaldehyde.

[0023] The tertiary amine primary amine is at least one of N,N-dimethyl-1,3-propylenediamine, N,N-dimethylethylenediamine, and N,N-dimethylbutylenediamine.

[0024] Preferably, the base oil is ester oil and / or perfluoropolyether;

[0025] The ester oil is an oil having an ester group.

[0026] Preferably, the thickener is at least one of polyurea thickener, polytetrafluoroethylene, and bentonite.

[0027] Preferably, the antioxidant is an amine antioxidant and / or a phenolic antioxidant.

[0028] In the present invention:

[0029] Base oils serve as a lubricating medium and carrier, forming the bulk of lubricants and providing fluid lubrication, cooling (helping dissipate heat), and a foundation for carrying other additives. The core functions of selected ester oils and perfluoropolyether (PFPE) are to provide extremely high temperature resistance, oxidation stability, and a wide operating temperature range.

[0030] Thickeners build the structural framework of the lubrication system (thickening) and store the lubricant. They thicken the base oil (liquid) into a semi-solid or paste (grease form), enabling it to adhere to working surfaces (such as bearings and gears) and release the base oil appropriately under shear to lubricate. The core function of polyurea, PTFE, and bentonite is to provide the high-temperature stability, colloidal stability, and structural strength required by the lubricant.

[0031] Molybdenum disulfide is a solid lubricant and extreme pressure anti-wear additive. Its layered structure slides on the friction surface, effectively reducing friction and preventing wear even under high temperature and high load conditions. It provides backup lubrication when the base oil film may fail (such as in extreme pressure boundary lubrication), significantly improving resistance to galling and seizure. It directly protects against mechanical wear.

[0032] The sulfonic acid group-quaternary ammonium salt complex is the core product of the present invention, which has the characteristics of multifunctional integration and molecular design; it combines the quaternary ammonium salt anti-rust / corrosion inhibition group (especially for water vapor and acidic substances) with the organic sulfonate anti-rust group (good oil solubility and film-forming protection, and a certain acid neutralization ability) into one molecular structure. The quaternary ammonium salt group provides efficient rust prevention (against moisture, seawater, and salt spray) and anti-corrosion protection. The quaternary ammonium ion can be firmly adsorbed on the metal surface to form a hydrophobic layer, isolating moisture and corrosive media. It has good anti-rust durability. It protects against chemical corrosion. The sulfonic acid group itself is also an excellent oil-soluble rust inhibitor, forming a dense protective film on the metal surface. At the same time, the introduction of calcium sulfonate further enhances its ability to neutralize acid (provide alkaline reserves), preventing acidic substances from corroding the metal. In addition, the sulfonate group may help assist molybdenum disulfide in forming a high-strength surface film under boundary lubrication conditions.

[0033] The preparation of the sulfonic acid-quaternary ammonium salt complex ensures reliable reproduction of the product structure and performance through a four-step synthesis route (Schiff base + alkylation + purification + compounding). In particular, the use of high-boiling-point dimethyl carbonate as an alkylating agent (step S2) and precise ratio control (such as 1:1-1.1 molar ratio in step S1 and 1:1.05-1.1 molar ratio in step S4) ensure the conversion rate and product purity. Inert gas protection and pressure control (step S2) improve process safety and efficiency. Adequate solvent consumption (step S4, at least 3 times the total amount of solids) ensures the adequacy and operability of the reaction.

[0034] The reaction mechanism of each step in the preparation of the sulfonic acid group-quaternary ammonium salt complex of the present invention is:

[0035] Step S1 is to synthesize a Schiff base intermediate, wherein a sulfonic acid aldehyde and dimethylpropylenediamine undergo a condensation reaction to construct a reactant having an imine bond (C=N).

[0036] Step S2 is the methylation of tertiary amine. First, dimethyl carbonate is activated under alkaline conditions, and then the tertiary amine nitrogen attacks the methyl carbon of dimethyl carbonate (DMC) with nucleophilicity to generate quaternary ammonium salt and methyl carbonate anion.

[0037] Step S3 is mainly to recycle DMC and remove unreacted impurities, such as sodium sulfonate and residual DMC.

[0038] Step S4 is a solubility-driven ion exchange; the quaternary ammonium bicarbonate and calcium sulfonate undergo double decomposition to generate an oil-soluble quaternary ammonium sulfonate and a calcium carbonate precipitate.

[0039] Antioxidants slow down the oxidative degradation of lubricants at high temperatures. They prevent or delay oxidative deterioration of base oils and thickeners (e.g., increased viscosity, acidification, coking, and varnish sludge formation) caused by high temperatures and oxygen. This helps maintain lubricant performance stability and extend service life. Amine and phenolic antioxidants are selected because they are particularly effective in high-temperature lubrication systems.

[0040] Overall, the present invention utilizes a base oil and thickener to create a high-temperature-resistant physical framework. The antioxidant ensures the long-term stability of this framework at high temperatures. Molybdenum disulfide and the sulfonic acid-quaternary ammonium salt complex work together on the friction surface, providing protection against mechanical wear and chemical corrosion, respectively, while maintaining effectiveness even at high temperatures. This invention meets the stringent requirements for high-temperature, wear-resistant, and rust-resistant applications. DETAILED DESCRIPTION

[0041] In order to better understand the present invention, the present invention is further described below in conjunction with specific serial numbers, wherein the terms used in the serial numbers are for describing specific embodiments and do not constitute a limitation on the scope of protection of the present invention.

[0042] In the present invention, DMC refers to dimethyl carbonate.

[0043] Example 1 The preparation of the sulfonic acid group-quaternary ammonium salt complex comprises the following steps:

[0044] S1: Sodium 3-sulfonate benzaldehyde is added to water to completely dissolve it, and the temperature is controlled at 50-60°C. N,N-dimethyl-1,3-propanediamine is added and the pH is adjusted to 4 with glacial acetic acid. The temperature is raised to 80°C and refluxed for reaction. After the reaction is complete, the solid intermediate A is obtained by cooling, filtering, and drying.

[0045] The molar ratio of 3-sodium sulfonate benzaldehyde to N,N-dimethyl-1,3-propylenediamine is 1:1.

[0046] S2: Place intermediate A and dimethyl carbonate into a reaction vessel and adjust the pH to 8.0, replacing the gas in the system with nitrogen; then pressurize to 0.5 MPa; stir and heat to 160°C; then react for 10 hours; during the reaction, pressurize to 2±0.2 MPa; after the reaction is completed, release the pressure and cool, and filter to collect the filtrate.

[0047] S3: The filtrate was transferred to a distillation kettle and DMC was recovered by vacuum distillation. The residue was dissolved in 60°C hot water and decolorized with activated carbon for 30 minutes. After hot filtration, the filtrate was cooled to 5°C for crystallization. The product was centrifuged and the wet product was washed with cold ethanol to remove impurities. A slurry of intermediate B was obtained.

[0048] The molar ratio of intermediate A to dimethyl carbonate is 1:3.

[0049] S4: Dissolve the intermediate B slurry in a solvent, add calcium dinonylnaphthalenesulfonate, raise the temperature to ≥80°C, and stir to react for at least 2 hours;

[0050] The reaction generates a white calcium carbonate precipitate, which is removed by filtration. The organic phase is concentrated under reduced pressure to obtain a viscous substance, which is then fluidized bed dried to obtain a sulfonic acid-quaternary ammonium salt complex.

[0051] The molar ratio of intermediate B slurry to calcium nonylnaphthalenesulfonate is 1:1.05;

[0052] The solvent is a mixture of acetone and water in a ratio of 1:1, and the mass of the solvent is 3 times the total mass of the solid.

[0053] Example 2 The preparation of the sulfonic acid group-quaternary ammonium salt complex comprises the following steps:

[0054] S1: 4-Sodium sulfonate benzaldehyde is added to water to completely dissolve it, and the temperature is controlled at 50-60°C. N,N-dimethylethylenediamine is added and the pH is adjusted to 6 with glacial acetic acid. The temperature is raised to 80°C and refluxed for reaction. After the reaction is complete, the mixture is cooled, filtered, and dried to obtain a solid intermediate A.

[0055] The molar ratio of 4-sodium sulfonate benzaldehyde to N,N-dimethylethylenediamine is 1:1.1.

[0056] S2: Place intermediate A and dimethyl carbonate into a reaction vessel and adjust the pH to 9.0, replacing the gas in the system with nitrogen; then pressurize to 0.5 MPa; stir and heat to 160°C; then react for 10 hours; during the reaction, pressurize to 2±0.2 MPa; after the reaction is completed, release the pressure and cool, and filter to collect the filtrate.

[0057] S3: The filtrate was transferred to a distillation kettle and DMC was recovered by vacuum distillation. The residue was dissolved in 60°C hot water and decolorized with activated carbon for 30 minutes. After hot filtration, the filtrate was cooled to 5°C for crystallization. The product was centrifuged and the wet product was washed with cold ethanol to remove impurities. A slurry of intermediate B was obtained.

[0058] The molar ratio of intermediate A to dimethyl carbonate is 1:3.

[0059] S4: Dissolve the intermediate B slurry in a solvent, add calcium dinonylnaphthalenesulfonate, raise the temperature to ≥80°C, and stir to react for at least 2 hours;

[0060] The reaction generates a white calcium carbonate precipitate, which is removed by filtration. The organic phase is concentrated under reduced pressure to obtain a viscous substance, which is then fluidized bed dried to obtain a sulfonic acid-quaternary ammonium salt complex.

[0061] The molar ratio of intermediate B slurry to calcium nonylnaphthalenesulfonate is 1:1.10;

[0062] The solvent is a mixture of acetone and water in a ratio of 1:1, and the mass of the solvent is 3 times the total mass of the solid.

[0063] Example 3 The preparation of the sulfonic acid group-quaternary ammonium salt complex comprises the following steps:

[0064] S1: Sodium undecanesulfonate benzaldehyde is added to water to completely dissolve it, and the temperature is controlled at 50-60°C. N,N-dimethylbutanediamine is added and the pH is adjusted to 6 with glacial acetic acid. The temperature is raised to 80°C and refluxed for reaction. After the reaction is complete, the solid intermediate A is obtained by cooling, filtering, and drying.

[0065] The molar ratio of sodium undecanesulfonate benzaldehyde to N,N-dimethylbutanediamine is 1:1.1.

[0066] S2: Place intermediate A and dimethyl carbonate into a reaction vessel and adjust the pH to 1.05, replacing the gas in the system with nitrogen; then pressurize to 0.5 MPa; stir and heat to 160°C; then react for 10 hours; during the reaction, pressurize to 2±0.2 MPa; after the reaction is completed, release the pressure and cool, and filter to collect the filtrate.

[0067] S3: The filtrate was transferred to a distillation kettle and DMC was recovered by vacuum distillation. The residue was dissolved in 60°C hot water and decolorized with activated carbon for 30 minutes. After hot filtration, the filtrate was cooled to 5°C for crystallization. The product was centrifuged and the wet product was washed with cold ethanol to remove impurities. A slurry of intermediate B was obtained.

[0068] The molar ratio of intermediate A to dimethyl carbonate is 1:3.

[0069] S4: Dissolve the intermediate B slurry in a solvent, add calcium dinonylnaphthalenesulfonate, raise the temperature to ≥80°C, and stir to react for at least 2 hours;

[0070] The reaction generates a white calcium carbonate precipitate, which is removed by filtration. The organic phase is concentrated under reduced pressure to obtain a viscous substance, which is then fluidized bed dried to obtain a sulfonic acid-quaternary ammonium salt complex.

[0071] The molar ratio of intermediate B slurry to calcium nonylnaphthalenesulfonate is 1:1.10;

[0072] The solvent is a mixture of acetone and water in a ratio of 1:1, and the mass of the solvent is 3 times the total mass of the solid.

[0073] Example 4 Preparation of a composite anti-rust lubricant, comprising the following steps:

[0074] S1: Weigh each raw material according to the mass parts recorded in Table 1 below.

[0075] S2: Mix all the raw materials into a uniform shape, seal and set aside.

[0076] Table 1. Ratio of ingredients in composite anti-rust lubricant (parts by mass)

[0077]

[0078]

[0079] Table 1 (Continued) Composite Anti-Rust Lubricant Ingredient Ratio (Parts by Mass)

[0080]

[0081] The TAC in the TAC polyurea in Table 1 refers to triallyl cyanurate.

[0082] The performance test of the composite anti-rust lubricant prepared above was carried out:

[0083] Dropping point test: The dropping point test is carried out according to GB / T 4929-1985 Determination of the dropping point of grease.

[0084] PD value test: According to GB / T 12583-1998 Lubricant Extreme Pressure Performance Determination (Four-ball Method) PD value test

[0085] Liquid phase corrosion test: The test is conducted according to GB / T 11143-2008 Test method for rust prevention of mineral oil with inhibitor in the presence of water. The results are classified as follows:

[0086] Rust-free: Steel rods have no rust spots

[0087] Slight rust: limited to no more than 6 rust spots, and the diameter of each rust spot is no more than 1mm.

[0088] Moderate rust: Rust occurs on more than 6 points but less than 5% of the surface area of ​​the test bar.

[0089] Severe rust: The rusted area exceeds 5% of the surface area of ​​the test steel bar.

[0090] The results are shown in Table 2 below.

[0091] Table 2 Composite anti-rust lubricant performance test results

[0092]

[0093]

[0094] In Table 2, due to the difference in base oil, the dropping point of perfluoropolyether is much higher than that of pentaerythritol oleate, resulting in differences in their dropping point performance (comparison of Nos. 1, 2, and 3 with Nos. 4 and 5). It can be seen that the type of rust inhibitor has no significant effect on the dropping point. However, as the base oil content increases, the PD value decreases.

[0095] In Table 2, No. 1 and No. 6, 7, and 8 are comparisons of different types of rust inhibitors. It can be seen that the sulfonic acid-quaternary ammonium salt complex can significantly increase its PD value, and its principle is consistent with that described above.

[0096] At the same time, the sulfonic acid-quaternary ammonium salt complex also achieves excellent anti-rust effect by relying on its strong adsorption film and chemical inertness.

[0097] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of the present invention. In practical applications, technicians in this field can select part or all of it according to actual needs to achieve the purpose of the embodiment scheme, and no limitation is made here.

[0098] In addition, for technical details not fully described in this embodiment, please refer to the parameter operation method provided in any embodiment of the present invention, and will not be repeated here.

[0099] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0100] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0101] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the description of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high temperature resistant composite anti-rust lubricant, characterized in that: The following components are included in parts by mass: The sulfonic acid group-quaternary ammonium salt complex is prepared by Schiff base reaction of sulfonic acid group aldehyde and tertiary amino group primary amine, followed by alkylation.

2. The high temperature resistant composite anti-rust lubricant according to claim 1, characterized in that: The preparation method of the sulfonic acid group-quaternary ammonium salt complex comprises the following steps: S1: Add sulfonic acid aldehyde to water and dissolve it at 50-60°C, add tertiary amine and primary amine and adjust the pH to 4-6; heat to ≥80°C and reflux for reaction; after the reaction is complete, cool, filter and dry to obtain solid intermediate A; S2: Place intermediate A and dimethyl carbonate into a reaction vessel and adjust the pH to 8.0-10.

5. Replace the gas in the system with an inert gas; then pressurize to ≥0.5 MPa; stir and heat to at least 160°C; then react for at least 10 hours; during the reaction, pressurize to 2±0.2 MPa; after the reaction is complete, release the pressure, cool, and filter to collect the filtrate; S3: Purify the filtrate to obtain intermediate B slurry; S4: The intermediate B slurry is dissolved in a solvent, and calcium dinonylnaphthalenesulfonate is added. The temperature is raised to ≥80°C and stirred for reaction for at least 2 hours. The solid matter is removed by filtration, and the mixture is concentrated under reduced pressure and dried to obtain a sulfonic acid-quaternary ammonium salt complex.

3. The high temperature resistant composite anti-rust lubricant according to claim 2, characterized in that: In step S1 of the method for preparing the sulfonic acid group-quaternary ammonium salt complex, the molar ratio of the sulfonic acid group aldehyde to the tertiary amino group and primary amine is 1:1-1.

1.

4. The high temperature resistant composite anti-rust lubricant according to claim 2, characterized in that: In step S2 of the method for preparing the sulfonic acid group-quaternary ammonium salt complex, the molar ratio of the intermediate A to dimethyl carbonate is 1: at least 3.

5. The high temperature resistant composite anti-rust lubricant according to claim 2, characterized in that: Step S3 of the method for preparing the sulfonic acid group-quaternary ammonium salt complex specifically comprises: distilling the filtrate to remove excess dimethyl carbonate; dissolving the residue in hot water and then cooling and crystallizing, centrifuging, and then rinsing to remove impurities.

6. The high temperature resistant composite anti-rust lubricant according to claim 2, characterized in that: In step S4 of the method for preparing the sulfonic acid group-quaternary ammonium salt complex, the molar ratio of the intermediate B slurry to calcium nonylnaphthalenesulfonate is 1:1.05-1.1; The mass of the solvent is at least 3 times the total mass of the solids.

7. The high temperature resistant composite anti-rust lubricant according to claim 1, characterized in that: The sulfonic acid aldehyde is at least one of 3-sodium sulfonate benzaldehyde, 4-sodium sulfonate benzaldehyde, and undecane sodium sulfonate benzaldehyde; The tertiary amine primary amine is at least one of N,N-dimethyl-1,3-propylenediamine, N,N-dimethylethylenediamine, and N,N-dimethylbutylenediamine.

8. The high temperature resistant composite anti-rust lubricant according to claim 1, characterized in that: The base oil is ester oil and / or perfluoropolyether; The ester oil is an oil having an ester group.

9. The high temperature resistant composite anti-rust lubricant according to claim 1, characterized in that: The thickener is at least one of polyurea thickener, polytetrafluoroethylene and bentonite.

10. The high temperature resistant composite anti-rust lubricant according to claim 1, characterized in that: The antioxidant is an amine antioxidant and / or a phenolic antioxidant.

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