Preparation method of oxidation-resistant stain-free synthetic ether lubricating oil

Abstract

The invention relates to the technical field of industrial lubricating oil, in particular to a preparation method of oxidation-resistant stain-free synthetic ether lubricating oil which comprises the following components in parts by mass: 100 parts of PAG water-soluble polyether, 2-10 parts of a composite antioxidant, 1-3 parts of an extreme pressure anti-wear agent, 0.5-1.0 part of an ashless dispersant, 0.1-0.5 part of an antirust agent and 0.05-0.08 part of a defoaming agent. The preparation method of the oxidation-resistant stain-free synthetic ether lubricating oil comprises the following steps: S1, preheating; s2, compounding is carried out; s3, carrying out homogenization; and S4, filtering. According to the present invention, the formula is reasonable, the preparation operation is simple, the glyceryl borate, the 2, 5-dimercapto-1, 3, 4-thiadiazole and the 4, 4 '-dioctyl diphenylamine are compounded to form the composite antioxidant, such that the oxidation resistance of the synthetic ether lubricating oil can be significantly improved, and the dual requirements of high temperature oxidation resistance, cleaning and no stain can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial lubricating oils, and specifically relates to a preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil. Background Technique

[0002] Polyether lubricants play an important role in synthetic lubricants and are excellent in basic lubricating oil properties, environmental tolerance during use, and environmental friendliness compared with traditional mineral oils. With the development of industrial equipment towards high temperature, precision, and environmental protection, traditional mineral oils and synthetic hydrocarbon lubricating oils are prone to oxidation and coking under high-temperature conditions, and sulfur / phosphorus-containing additives can cause metal surface contamination, making it difficult to meet the stain-free cleaning requirements of precision machinery. Water-soluble polyether lubricating oils have become a potential solution due to their excellent high-temperature stability and natural water solubility.

[0003] Chinese invention application with the publication number CN118028043A discloses a lubricating oil composition for a photovoltaic tracker worm gear, which uses water-soluble polyether in combination with phenolic antioxidants and amine antioxidants. However, phenolic or amine antioxidants are prone to saturation in water-soluble polyether lubricating oils, not only resulting in limited improvement in the rotating oxygen bomb value, but also causing oxidation products to easily form gums and sludges at high temperatures. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil to solve the problems raised in the above background technique.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil, the oxidation-resistant and stain-free synthetic ether lubricating oil includes the following components by mass: 100 parts of PAG water-soluble polyether, 2 - 10 parts of a compound antioxidant, 1 - 3 parts of an extreme pressure and anti-wear agent, 0.5 - 1.0 part of an ashless dispersant, 0.1 - 0.5 part of a rust inhibitor, and 0.05 - 0.08 part of an antifoaming agent;

[0006] The compound antioxidant is composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole, and 4,4'-dioctyldiphenylamine with a mass ratio of (1 - 3):(1 - 3):(0.5 - 2);

[0007] The preparation method of the oxidation-resistant and stain-free synthetic ether lubricating oil includes the following steps:

[0008] S1. Preheating: Add PAG water-soluble polyether to a reaction kettle, heat it to 60 ± 5°C, and stir for 60 min at 200 - 300 rpm;

[0009] S2. Compound blending: First, divide the compound antioxidant into three portions and add them to the reaction kettle in batches. Stir for 10 min at 200 - 300 rpm each time after adding one portion. Then, add the extreme pressure anti-wear agent, ashless dispersant, rust inhibitor, and defoamer to the reaction kettle in sequence and stir for 60 min at 200 - 300 rpm to obtain a mixture.

[0010] S3. Homogenization: Heat the mixture to 80 ± 5 °C and process it for 60 min at 5000 - 5500 rpm using a high-speed shear emulsifier to obtain a primary product.

[0011] S4. Filtration: Filter the primary product through a 5-μm filter to obtain the oxidation-resistant and stain-free synthetic ether lubricating oil.

[0012] Optionally, the EO / PO of the PAG water-soluble polyether is 50:50 - 70:30.

[0013] Optionally, the compound antioxidant is composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole, and 4,4'-dioctyldiphenylamine with a mass ratio of 2:2:1.

[0014] Optionally, the extreme pressure anti-wear agent is tritolyl phosphate or triphenyl thiophosphate.

[0015] Optionally, the ashless dispersant is polyisobutylene succinimide or Mannich base ashless dispersant.

[0016] Optionally, the rust inhibitor is dodecenyl succinic acid ester or dodecenyl succinic acid diethanolamide.

[0017] Optionally, the defoamer is polyether-modified silicone oil.

[0018] Optionally, the 40 °C kinematic viscosity of the oxidation-resistant and stain-free synthetic ether lubricating oil is 46 - 52 mm 2 / s.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The formula of the present invention is reasonable and the preparation operation is simple. By compounding glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole, and 4,4'-dioctyldiphenylamine to form a compound antioxidant, the antioxidant property of the synthetic ether lubricating oil can be significantly improved, and at the same time, the dual requirements of high-temperature antioxidant and clean and stain-free are met.

[0021] 2. The 40 °C kinematic viscosity of the oxidation-resistant and stain-free synthetic ether lubricating oil prepared by the present invention is 46 - 52 mm2 / s, with a moderate viscosity, suitable for gear oils, hydraulic oils, etc. Specific embodiments

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] Embodiment 1: The present invention provides a preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil. The oxidation-resistant and stain-free synthetic ether lubricating oil comprises the following components by mass: 100 parts of PAG water-soluble polyether, 2 parts of compound antioxidant, 1 part of tritolyl phosphate, 0.5 part of polyisobutylene succinimide, 0.1 part of dodecenyl succinic acid ester, and 0.05 part of polyether-modified silicone oil; wherein, the EO / PO in the PAG water-soluble polyether is 50:50.

[0024] The compound antioxidant is composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole and 4,4'-dioctyldiphenylamine with a mass ratio of 1:1:1.

[0025] The preparation method of the oxidation-resistant and stain-free synthetic ether lubricating oil comprises the following steps:

[0026] S1. Preheating: Add the PAG water-soluble polyether into a reaction kettle, heat it to 55°C, and stir for 60 min at 200 rpm.

[0027] S2. Compound blending: First, divide the compound antioxidant into three portions and add them into the reaction kettle in batches. Stir for 10 min at 200 rpm each time after adding 1 portion. Then, add tritolyl phosphate, polyisobutylene succinimide, dodecenyl succinic acid ester and polyether-modified silicone oil into the reaction kettle in sequence, and stir for 60 min at 200 rpm to obtain a mixture.

[0028] S3. Homogenization: Heat the mixture to 80 ± 5°C, and process it with a high-speed shear emulsifier at 5000 rpm for 60 min to obtain a primary product.

[0029] S4. Filtration: Pass the primary product through a 5-μm filter to obtain the oxidation-resistant and stain-free synthetic ether lubricating oil.

[0030] Embodiment 2: The present invention provides a preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil. The oxidation-resistant and stain-free synthetic ether lubricating oil comprises the following components by mass: 100 parts of PAG water-soluble polyether, 4 parts of compound antioxidant, 2 parts of tritolyl phosphate, 0.4 part of Mannich base ashless dispersant, 0.4 part of dodecenyl succinic acid diethanolamide, and 0.06 part of polyether-modified silicone oil; wherein, the EO / PO in the PAG water-soluble polyether is 50:50.

[0031] The compound antioxidant consists of glycerol borate, 2,5 - dimercapto - 1,3,4 - thiadiazole and 4,4'-dioctyldiphenylamine with a mass ratio of 2:2:1.25.

[0032] The preparation method of the oxidation - resistant and stain - free synthetic ether lubricating oil comprises the following steps:

[0033] S1. Preheating: Add PAG water - soluble polyether into the reaction kettle, heat it to 60 ± 5 °C, and stir for 60 min at 200 - 300 rpm;

[0034] S2. Compound blending: First, divide the compound antioxidant into three portions and add them into the reaction kettle in batches. Stir for 10 min at 200 - 300 rpm after adding each portion. Then, add tritolyl phosphate, Mannich base ashless dispersant, diethanolamide dodecene - based succinic acid and polyether - modified silicone oil into the reaction kettle in sequence, and stir for 60 min at 200 - 300 rpm to obtain a mixture;

[0035] S3. Homogenization: Heat the mixture to 80 ± 5 °C, and process it with a high - speed shear emulsifier at 5000 - 5500 rpm for 60 min to obtain a primary product;

[0036] S4. Filtration: Filter the primary product through a 5 - μm filter to obtain the oxidation - resistant and stain - free synthetic ether lubricating oil.

[0037] Example 3: The present invention provides a preparation method of an oxidation - resistant and stain - free synthetic ether lubricating oil. The oxidation - resistant and stain - free synthetic ether lubricating oil comprises the following components by mass: 100 parts of PAG water - soluble polyether, 8 parts of compound antioxidant, 2 parts of triphenyl thiophosphate, 0.8 part of polyisobutylene succinimide, 0.4 part of diethanolamide dodecene - based succinic acid, 0.06 part of polyether - modified silicone oil; wherein, the EO / PO in the PAG water - soluble polyether is 60:40.

[0038] The compound antioxidant consists of glycerol borate, 2,5 - dimercapto - 1,3,4 - thiadiazole and 4,4'-dioctyldiphenylamine with a mass ratio of 2:2:1.

[0039] The preparation method of the oxidation - resistant and stain - free synthetic ether lubricating oil comprises the following steps:

[0040] S1. Preheating: Add PAG water - soluble polyether into the reaction kettle, heat it to 62 °C, and stir for 60 min at 240 rpm;

[0041] S2. Blending: First, divide the compound antioxidant into three portions and add them to the reaction kettle in batches. Stir for 10 min at 240 rpm each time after adding one portion. Then, add triphenyl thiophosphate, polyisobutylene succinimide, diethanolamide dodecylenesuccinate, and polyether-modified silicone oil to the reaction kettle in sequence and stir for 60 min at 240 rpm to obtain a mixture;

[0042] S3. Homogenization: Heat the mixture to 80 °C and process it for 60 min at 5200 rpm using a high-speed shear emulsifier to obtain a primary product;

[0043] S4. Filtration: Pass the primary product through a 5-μm filter to obtain an oxidation-resistant and stain-free synthetic ether lubricating oil.

[0044] Example 4: The present invention provides a method for preparing an oxidation-resistant and stain-free synthetic ether lubricating oil. The components of the oxidation-resistant and stain-free synthetic ether lubricating oil by mass include: 100 parts of PAG water-soluble polyether, 10 parts of compound antioxidant, 3 parts of triphenyl thiophosphate, 1.0 part of Mannich base ashless dispersant, 0.5 part of diethanolamide dodecylenesuccinate, and 0.08 part of polyether-modified silicone oil; among them, the EO / PO in the PAG water-soluble polyether is 70:30.

[0045] The compound antioxidant consists of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole, and 4,4'-dioctyldiphenylamine with a mass ratio of 3:3:2.

[0046] The method for preparing the oxidation-resistant and stain-free synthetic ether lubricating oil includes the following steps:

[0047] S1. Preheating: Add the PAG water-soluble polyether to the reaction kettle, heat it to 65 °C, and stir for 60 min at 300 rpm;

[0048] S2. Blending: First, divide the compound antioxidant into three portions and add them to the reaction kettle in batches. Stir for 10 min at 300 rpm each time after adding one portion. Then, add triphenyl thiophosphate, Mannich base ashless dispersant, diethanolamide dodecylenesuccinate, and polyether-modified silicone oil to the reaction kettle in sequence and stir for 60 min at 300 rpm to obtain a mixture;

[0049] S3. Homogenization: Heat the mixture to 85 °C and process it for 60 min at 5500 rpm using a high-speed shear emulsifier to obtain a primary product;

[0050] S4. Filtration: Pass the primary product through a 5-μm filter to obtain an oxidation-resistant and stain-free synthetic ether lubricating oil.

[0051] Comparative Example 1:

[0052] It is basically the same as Example 3, and the only difference is that 4,4'-dioctyldiphenylamine is used to replace the compound antioxidant.

[0053] Comparative Example 2:

[0054] It is basically the same as Example 3, and the only difference is that 2,6-di-tert-butyl-p-cresol and 4,4'-dioctyldiphenylamine are used, and the mass ratio of 2,6-di-tert-butyl-p-cresol to diisooctyldiphenylamine antioxidant is 1:1.

[0055] Test Example 1:

[0056] Test content: According to the EXXON annealing box method, the oxidation-resistant stain-free synthetic ether lubricating oils prepared in Examples 1 to 4 were respectively added to the aluminum rolling oil at a concentration of 8% by mass fraction, stirred evenly to obtain a sample. The physical and chemical properties of the aluminum rolling oil are shown in Table 1. 0.125 ml of the sample was dropped on the surface of the aluminum foil, spread evenly, placed in an EXXON annealing box, and the EXXON annealing box was placed in an annealing furnace. It was kept at 220 °C for 0.5 h, kept at 410 °C for 0.5 h, and cooled with the furnace. The pollution situation on the surface of the aluminum foil was observed, and the results were recorded in Table 2.

[0057] Table 1

[0058] Distillation range / °C Closed cup flash point / °C <![CDATA[Viscosity at 40°C (mm 2 / s)]]> Acid value (mgKOH / g) Sulfur content (mg / kg) Color Aluminum rolling oil 230～255 103 2.34 0.02 0.0002 Transparent

[0059] Test Example 2

[0060] Test content: According to the test method disclosed in SH / T 0074-1991, the oxidation stability of the oxidation-resistant stain-free synthetic ether lubricating oils prepared in Examples 1 to 4 and Comparative Example 1 was respectively tested by the rotating bomb method. The results were recorded in Table 2. The test temperature was 160 °C, and the test conditions of the oxidation bomb were: pressure 620 Kpa, rotation speed 100 rpm. The oxidation stability was the time required for the pressure of the oxidation bomb to drop from the highest point to 172 kPa.

[0061] Table 2

[0062] Surface contamination condition Oxidation stability / min Example 1 No stain 288 Example 2 No stain 310 Example 3 No stain 319 Example 4 No stain 311 Comparative example 1 - 125 Comparative example 2 - 220

[0063] As can be seen from Table 2, the oxidation-resistant stain-free synthetic ether lubricating oils prepared in Examples 1 to 4 are stain-free synthetic lubricating oils. Compared with Comparative Example 2, the oxidation stability of the oxidation-resistant stain-free synthetic ether lubricating oils prepared in Examples 1 to 4 is improved by 30% to 45%. The antioxidant composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole and 4,4'-dioctyldiphenylamine has much greater antioxidant properties than the linear superposition of the antioxidant properties of phenolic antioxidants and amine antioxidants. Among them, Example 3 shows the best performance. Therefore, the antioxidant composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole and 4,4'-dioctyldiphenylamine can greatly improve the oxidation stability of the oxidation-resistant stain-free synthetic ether lubricating oil. The kinematic viscosity at 40 °C of the oxidation-resistant stain-free synthetic ether lubricating oils prepared in Examples 1 to 4 was measured by a kinematic viscosity meter to be 46 to 52 mm 2 / s, with moderate viscosity, suitable for gear oils, hydraulic oils, etc.

[0064] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil, characterized in that: The oxidation-resistant and stain-free synthetic ether lubricating oil comprises the following components by mass parts: 100 parts of PAG water-soluble polyether, 2-10 parts of a compound antioxidant, 1-3 parts of an extreme pressure and anti-wear agent, 0.5-1.0 part of an ashless dispersant, 0.1-0.5 part of a rust inhibitor, and 0.05-0.08 part of an antifoaming agent; The compound antioxidant is composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole and 4,4'-dioctyldiphenylamine with a mass ratio of (1-3):(1-3):(0.5-2); The preparation method of the oxidation-resistant and stain-free synthetic ether lubricating oil comprises the following steps: S1. Preheating: Add the PAG water-soluble polyether into a reaction kettle, heat it to 60±5°C, and stir for 60 min at 200-300 rpm; S2. Compound blending: First, divide the compound antioxidant into three batches and add them into the reaction kettle in turn. Stir for 10 min at 200-300 rpm each time after adding 1 part. Then, add the extreme pressure and anti-wear agent, ashless dispersant, rust inhibitor and antifoaming agent into the reaction kettle in turn, and stir for 60 min at 200-300 rpm to obtain a mixture; S3. Homogenization: Heat the mixture to 80±5°C, and treat it with a high-speed shear emulsifier at 5000-5500 rpm for 60 min to obtain a primary product; S4. Filtration: Filter the primary product through a 5-μm filter to obtain the oxidation-resistant and stain-free synthetic ether lubricating oil.

2. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, characterized in that: In the PAG water-soluble polyether, the EO / PO is 50:50-70:

30.

3. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, characterized in that: The compound antioxidant is composed of glycerol borate, 2,5-dimercapto-1,3,4-thiadiazole and 4,4'-dioctyldiphenylamine with a mass ratio of 2:2:1; 4. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, characterized in that: The extreme pressure and anti-wear agent is tritolyl phosphate or triphenyl thiophosphate; 5. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, characterized in that: The ashless dispersant is polyisobutylene succinimide or Mannich base ashless dispersant; 6. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, characterized in that: The rust inhibitor is dodecenyl succinic acid ester or dodecenyl succinic acid diethanolamide; 7. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, wherein: The antifoaming agent is polyether-modified silicone oil.

8. The preparation method of an oxidation-resistant and stain-free synthetic ether lubricating oil according to claim 1, characterized in that: The kinematic viscosity of the oxidation-resistant and stain-free synthetic ether lubricating oil at 40 °C is 46 to 52 mm 2 / s.