A friction-reducing hydraulic oil composition and preparation method thereof

Abstract

The present invention belongs to the technical field of lubricating oil additives, and specifically relates to a friction-reducing hydraulic oil composition and a preparation method thereof. The friction-reducing hydraulic oil composition comprises the following components by mass fraction: 0.2%-2% of anti-wear agent, 0.2%-1% of antioxidant, 0.01%-0.08% of detergent, 0.2%-0.5% of metal passivator, 0.05%-0.5% of rust inhibitor, 0.01%-0.6% of demulsifier, 0.01%-2% of friction-reducing agent, 0.001%-0.1% of anti-foaming agent, and the balance is base oil. The friction-reducing hydraulic oil composition provided by the present invention has a low friction coefficient and can solve the problem of shaking and abnormal noise of hydraulic cylinders during operation.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oil additives, and in particular relates to a friction-reducing hydraulic oil composition and a preparation method thereof. Background Art

[0002] The earliest liquid used in hydraulic systems was water, but it corroded metals and had poor lubrication. The emergence of mineral oil solved the lubrication problem, but there was still the problem of equipment corrosion due to the formation of colloid and acidification. With the rise of additive technology, a large number of anti-corrosion, anti-rust and anti-oxidation additives have emerged and are widely used in industry. With the rapid development of hydraulic technology, the working pressure of hydraulic systems has continued to increase, and the requirements for oil products have also become higher.

[0003] The existing hydraulic oil has insufficient anti-friction property, and the hydraulic cylinder is prone to vibrate and make abnormal noise during operation, which affects the service life of the hydraulic cylinder. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides a friction-reducing hydraulic oil composition and a preparation method thereof. The friction-reducing hydraulic oil composition has a low friction coefficient and can solve the problem of vibration and abnormal noise in the operation of the hydraulic cylinder.

[0005] In order to solve the deficiencies of the prior art, the technical solution provided by the present invention is:

[0006] A friction-reducing hydraulic oil composition comprises the following components in mass fractions: 0.2%-2% of an anti-wear agent, 0.2%-1% of an antioxidant, 0.01%-0.08% of a detergent, 0.2%-0.5% of a metal passivator, 0.05%-0.5% of a rust inhibitor, 0.01%-0.6% of an anti-emulsifier, 0.01%-2% of a friction-reducing agent, 0.001%-0.1% of an anti-foaming agent, and the balance is base oil.

[0007] Preferably, the friction reducing agent is a mixture of pentaerythritol monoester and pentaerythritol tetraester.

[0008] Preferably, the pentaerythritol monoester is pentaerythritol monooleate; and the pentaerythritol tetraester is pentaerythritol tetraoleate.

[0009] Preferably, the mass ratio of the pentaerythritol monoester to the pentaerythritol tetraester is (1-4):(6-9).

[0010] Preferably, the mass ratio of pentaerythritol monoester to pentaerythritol tetraester is 2:3.

[0011] Preferably, the antiwear agent includes one or more of sulphurized olefins, thiophosphates, thiophosphate esters, thiophosphate amine salts, and triphenyl phosphate;

[0012] and / or,

[0013] The antioxidant includes one or more of hindered phenol, alkyl diphenylamine and naphthylamine.

[0014] Preferably, the detergent comprises one or more of sulfonates, sulphurised alkylphenols and salicylates;

[0015] and / or,

[0016] The rust inhibitor includes one or more of sulfonates, carboxylates, phosphates, amides, and carboxylate amide salts.

[0017] Preferably, the metal deactivator includes one or more of carboxylic acid derivatives, benzotriazole derivatives, and thiadiazole derivatives;

[0018] and / or,

[0019] The anti-emulsifier includes one or more of polyether, polyisobutylene succinamide, and petroleum sulfonate.

[0020] Preferably, the antifoaming agent is a silicone oil antifoaming agent or a non-silicone antifoaming agent;

[0021] and / or,

[0022] The base oil is a base oil of API Class II or above.

[0023] A method for preparing a friction-reducing hydraulic oil composition, comprising:

[0024] S1: Weigh each component according to the mass fraction of the aforementioned anti-friction hydraulic oil composition;

[0025] S2: uniformly mix the anti-wear agent, antioxidant, detergent, metal passivator, rust inhibitor, demulsifier, friction reducer and base oil, add the anti-foaming agent and mix uniformly to obtain the aforementioned friction-reducing hydraulic oil composition.

[0026] Beneficial effects of the present invention:

[0027] The invention achieves good wear reduction, anti-wear and oil-water separation performance by compounding pentaerythritol monoester and pentaerythritol tetraester and adjusting the ratio of pentaerythritol monoester and pentaerythritol tetraester. The four-ball average friction coefficient and SRV average friction coefficient of the prepared wear-reducing hydraulic oil composition are greatly reduced. The wear-reducing hydraulic oil composition prepared based on the invention has good wear reduction performance, changes the contact form of the surfaces of the four-ball steel balls, reduces the friction coefficient between the friction pairs, and can effectively improve the shaking and creeping problem of the hydraulic cylinder caused by the excessively large friction coefficient.

[0028] The anti-friction hydraulic oil composition provided by the present invention also has good anti-wear performance, anti-oxidation performance, detergency, rust prevention and oil-water separation performance, can meet various requirements of hydraulic oil, and prolong the service life of hydraulic oil. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0030] The embodiment of the present invention provides a friction-reducing hydraulic oil composition, comprising the following components in mass fractions: 0.2%-2% of an anti-wear agent, 0.2%-1% of an antioxidant, 0.01%-0.08% of a detergent, 0.2%-0.5% of a metal passivator, 0.05%-0.5% of a rust inhibitor, 0.01%-0.6% of an anti-emulsifier, 0.01%-2% of a friction-reducing agent, 0.001%-0.1% of an anti-foaming agent, and the balance being base oil.

[0031] In an optional embodiment of the present invention, the friction reducing agent is a mixed ester of pentaerythritol monoester and pentaerythritol tetraester, preferably a mixed ester of pentaerythritol monooleate and pentaerythritol tetraoleate.

[0032] Pentaerythritol ester is commonly used as a base oil in high-end oil products, but there is little research on its use as a friction modifier to improve the wear and anti-wear properties of oil products.

[0033] The present invention finds that pentaerythritol monoester has good wear reduction performance and has the potential to be used as a wear reducer in hydraulic oil. However, the anti-wear performance of pentaerythritol monoester is weaker than that of pentaerythritol tetraester, and the oil-water separation performance is poor, which cannot meet the requirement of water separation <30min in the product standard of GB / T11118.1 "Hydraulic Oil". In view of the above problems, the present invention adopts pentaerythritol tetraester and pentaerythritol monoester for compounding, and increases the anti-wear performance on the basis of improving the oil-water separation performance.

[0034] Taking pentaerythritol monooleate (PETO-1) and pentaerythritol tetraoleate (PETO-4) produced by Zhejiang Zhongcheng Environmental Protection Company as examples, Table 1 shows the average friction coefficient (characterizing the anti-friction performance), wear spot diameter (characterizing the anti-wear performance) and oil-water separation performance data of each formula when the mass ratio of pentaerythritol monooleate and pentaerythritol tetraoleate is different. Among them, pentaerythritol monooleate and pentaerythritol tetraoleate are stirred at 75°C for 3 hours to mix evenly.

[0035] According to NB / SH / T 0189 “Four-ball method for determination of anti-wear properties of lubricating oils”, the wear spot diameters of different formulations were tested by MRS-1J four-ball testing machine. The test parameters were 392N, 600r / min, 75℃ and running time of 60 minutes.

[0036] According to ASTM D5183 Standard Test Method for Determination of the Coefficient of Friction of Lubricants Using the Four-Ball Wear Test Machine, the average friction coefficient of different formulations was tested by an MRS-1J four-ball testing machine. The test parameters were 392N, 600r / min, 75°C, and a running time of 60 minutes.

[0037] Afterwards, each formula was added to the No. 46 anti-wear hydraulic oil of China National Petroleum Corporation at a mass fraction of 0.5%, and the oil-water separation performance of each formula was tested according to GB / T 7305 "Determination of water separation of petroleum and synthetic fluids". The oil-water separation performance of GB / T 11118.1 "Hydraulic oil" product standard <30min can meet the requirements.

[0038] Table 1 Friction properties and oil-water separation properties of pentaerythritol mixed esters

[0039]

[0040] The present invention adds formulas 1-11 into the No. 46 anti-wear hydraulic oil of China National Petroleum Corporation at a mass fraction of 0.5%, installs a DY-3093B vibration acceleration sensor at the middle point of the variable amplitude oil cylinder, tests the vibration acceleration of each measuring point of the variable amplitude action of the engine idling condition before and after the improvement, evaluates the improvement of the oil cylinder shaking and abnormal noise problem by the friction modifier, and when the average friction coefficient of the pentaerythritol mixed ester is lower than 0.07, the pentaerythritol mixed ester can effectively improve the shaking and creeping problem of the hydraulic oil cylinder caused by the excessive friction coefficient after adding the No. 46 anti-wear hydraulic oil of China National Petroleum Corporation. It can be seen from the table that when the mass ratio of pentaerythritol monooleate to pentaerythritol tetraoleate is (1-4): (6-9), the average friction coefficient, wear spot diameter and oil-water separation performance of the mixed ester are all good. Preferably, the mass ratio of pentaerythritol monooleate to pentaerythritol tetraoleate is 2:3. That is, the present invention achieves the goals of good wear reduction, wear resistance and oil-water separation performance by compounding pentaerythritol tetraoleate and adjusting the ratio of pentaerythritol monooleate and pentaerythritol tetraoleate.

[0041] In an optional embodiment of the present invention, the antiwear agent includes one or more of sulfided olefins, sulfur phosphates, thiophosphates, thiophosphate amine salts, and triphenyl phosphate, preferably thiophosphates. Thiophosphates have good antiwear properties, can improve the disadvantage of poor thermal stability of traditional secondary alcohol-based ZDDP, and prevent sludge formation.

[0042] In an optional embodiment of the present invention, the antioxidant includes one or more of hindered phenol, alkyl diphenylamine, and naphthylamine. Preferably, the mixture of 2,6-di-tert-butyl-p-cresol and butyl octyl diphenylamine can effectively prolong the service life of the oil under high temperature and high pressure environment.

[0043] In an optional embodiment of the present invention, the detergent includes one or more of sulfonates, sulfurized alkylphenols, and salicylates, preferably high-base sulfurized calcium alkylphenols. High-base sulfurized calcium alkylphenols can effectively prevent the oxygen-containing acids generated by the oxidation of oil products, and prevent their further oxidation and condensation, reduce the formation of varnish and carbon deposits due to oxidation of oil products, and maintain good cleanliness of oil products.

[0044] In an optional embodiment of the present invention, the rust inhibitor includes one or more of sulfonates, carboxylates, phosphates, amides, and carboxylate amide salts, preferably dinonylsulfonic acid calcium salt.

[0045] In an optional embodiment of the present invention, the metal deactivator includes one or more of carboxylic acid derivatives, benzotriazole derivatives, and thiadiazole derivatives, preferably methylbenzotriazole derivatives.

[0046] In an optional embodiment of the present invention, the demulsifier includes one or more of polyether, polyisobutylene succinamide, and petroleum sulfonate, preferably polyether. Polyether can effectively improve the interfacial tension between oil and water.

[0047] In an optional embodiment of the present invention, the antifoaming agent is a silicone oil antifoaming agent or a non-silicone antifoaming agent, preferably a siloxane antifoaming agent, and most preferably dimethyl silicone oil. Dimethyl silicone oil can effectively improve the increase in foam caused by the miniaturization design of the hydraulic system oil tank, and has low procurement cost.

[0048] In an optional embodiment of the present invention, the base oil is a combination of API Class II or Class II+ 150N and 500N base oils. Preferably, the base oil is a blend of solvent-refined Formosa 150N and Formosa 500N base oils or a blend of hydroisomerized SK 150N and SK 500N base oils. The mass percentage of the base oil is 97%-99%.

[0049] The embodiment of the present invention also provides a method for preparing a friction-reducing hydraulic oil composition, comprising:

[0050] S1: Weigh each component according to the mass fraction of the aforementioned anti-friction hydraulic oil composition;

[0051] S2: Add anti-wear agent, antioxidant, detergent, metal passivator, rust inhibitor, anti-emulsifier, friction reducer and base oil into a blending container in proportion, heat to about 50°C under normal pressure, stir for 1 hour, finally add anti-foaming agent, continue stirring for 4 hours until the mixture is completely dissolved; then cool the resulting mixture to obtain the friction-reducing hydraulic oil composition.

[0052] In the following embodiments, pentaerythritol monooleate was purchased from Zhejiang Zhongcheng Environmental Protection Company, model PETO-1, and pentaerythritol tetraoleate was purchased from Zhejiang Zhongcheng Environmental Protection Company, model PETO-4. Polyol ester is a mixture of pentaerythritol monooleate and pentaerythritol tetraoleate in a mass ratio of 2:3. Ashless thiophosphates were purchased from BASF, model IRGALUBE232 and IRGALUBE 353. 2,6-di-tert-butyl-p-cresol was purchased from Jinzhou Kangtai Chemical Co., Ltd., model T502A. Butyloctyl diphenylamine was purchased from BASF, model IRGANOX L57. High base value sulfurized alkylphenol calcium was purchased from Chevron (China) Investment Co., Ltd., model OLOA 219. Tolyltriazole derivatives were purchased from BASF, model IRGAMET 39. Rust inhibitor is dinonyl sulfonic acid calcium salt purchased from Rhein Chemie (Qingdao) Co., Ltd., model RC4220. The polyether was purchased from LUBRIZOL, model number LUBRIZOL 5957. The dimethyl silicone oil was purchased from Jinzhou Kangtai Chemical Co., Ltd., model number KT901. The hydraulic oil compound package was purchased from LUBRIZOL, model number LUBRIZOL 5703. The oiliness agent was purchased from Huihua Petroleum Additives Co., Ltd., model number T406.

[0053] Example 1

[0054] Components of anti-friction hydraulic oil composition and their mass percentages:

[0055] The anti-wear agent is ashless thiophosphate (IRGALUBE 232): 0.55%;

[0056] The antioxidant is a mixture of 2,6-di-tert-butyl-p-cresol and butyl octyl diphenylamine in a mass ratio of 1:2: 0.5%;

[0057] The detergent is high base value sulfurized alkyl phenol calcium: 0.05%;

[0058] The metal passivator is a methylbenzotriazole derivative: 0.45%;

[0059] The rust inhibitor is calcium dinonylsulfonate: 0.08%;

[0060] Demulsifier is polyether: 0.03%;

[0061] The friction reducing agent is polyol ester: 0.4%;

[0062] The anti-foaming agent is dimethyl silicone oil: 0.002%;

[0063] Formosa Plastics II 150N base oil: 60%;

[0064] Formosa Plastics Group II 500N base oil: remainder.

[0065] Preparation method: Add anti-wear agent, antioxidant, detergent, metal passivator, rust inhibitor, anti-emulsifier, anti-friction agent and base oil into a blending container in proportion, heat to 50°C under normal pressure, stir for 1 hour, finally add anti-foaming agent, continue stirring for 4 hours until the mixture is completely dissolved; then cool the resulting mixture to obtain the anti-friction hydraulic oil composition.

[0066] Example 2

[0067] Components of anti-friction hydraulic oil composition and their mass percentages:

[0068] The anti-wear agent is ashless thiophosphate (model IRGALUBE 353): 0.35%;

[0069] The antioxidant is a mixture of 2,6-di-tert-butyl-p-cresol and butyloctyl diphenylamine in a mass ratio of 1:2: 0.45%;

[0070] The detergent is high base value sulfurized calcium alkyl phenol: 0.1%;

[0071] The metal passivator is a methylbenzotriazole derivative: 0.3%;

[0072] The rust inhibitor is calcium dinonylsulfonate: 0.08%;

[0073] Demulsifier is polyether: 0.03%;

[0074] The friction reducing agent is polyol ester: 0.3%;

[0075] The anti-foaming agent is dimethyl silicone oil: 0.002%;

[0076] SK II 150N base oil: 75%;

[0077] SK II 500N base oil: remainder.

[0078] Preparation method: Add anti-wear agent, antioxidant, detergent, metal passivator, rust inhibitor, anti-emulsifier, friction reducer and base oil into a blending container in proportion, heat to 50°C under normal pressure, stir for 1 hour, finally add anti-foaming agent, continue stirring for 4 hours until the mixture is completely dissolved; then cool the resulting mixture to obtain the finished product.

[0079] Comparative Example

[0080] Each component and its mass percentage:

[0081] Hydraulic oil compound package: 0.8%

[0082] Oiliness agent: 0.5%

[0083] Anti-foaming agent is dimethyl silicone oil: 0.001%

[0084] Formosa Plastics II 150N base oil: 70%

[0085] Formosa Plastics Group II 500N base oil: remainder.

[0086] Preparation method: Add the hydraulic oil compound package, oiliness agent and base oil into the blending container in proportion, heat to 50°C under normal pressure, stir for 1 hour, finally add the anti-foaming agent, continue stirring for 4 hours until the mixture is completely dissolved; then cool the resulting mixture to obtain the finished product.

[0087] Table 2 shows the performance parameters of the hydraulic oil compositions of the embodiments and comparative examples, and the test methods are as follows:

[0088] The kinematic viscosity at 40°C of different formulations was measured according to ASTM D445 “Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)”.

[0089] The viscosity index of different formulations was measured according to GB / T 1995 “Method for calculating viscosity index of petroleum products”.

[0090] The open cup flash point of different formulations was measured according to GB / T 3536 “Determination of Flash Point and Fire Point of Petroleum Products (Cleveland Open Cup Method)”.

[0091] The pour points of different formulations were measured according to GB / T 3535 “Determination of pour point of petroleum products”.

[0092] The acid values ​​of different formulations were measured according to GB / T 7304 “Determination of the acid value of petroleum products (potentiometric titration)”.

[0093] The chromaticity of different formulations was measured according to ASTM D1500 "Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)".

[0094] The corrosion degree of copper strips of different formulations was measured according to GB / T 5096 “Test method for copper strip corrosion of petroleum products”.

[0095] The liquid phase corrosion performance of different formulations was measured according to GB / T 11143 “Test method for rust prevention performance of mineral oil with inhibitor in the presence of water”.

[0096] The rotating oxygen bombs of different formulations were measured according to ASTM D2272 "Standard Test Method for Oxidation Stability of SteamTurbine Oils by Rotating Pressure Vessel".

[0097] The foam properties of different formulations were measured according to GB / T 12579 “Determination of Foam Properties of Lubricating Oils”.

[0098] The oil-water separation performance of different formulations was tested according to GB / T 7305 “Determination of water separation of petroleum and synthetic fluids”.

[0099] The air release properties of different formulations were tested according to ASTM D3427 “Standard Test Method for Air Release Properties of Hydrocarbon Based Oils”.

[0100] According to NB / SH / T 0189 “Four-ball method for determination of anti-wear properties of lubricating oils”, the wear spot diameters of different formulations were tested by MRS-1J four-ball testing machine. The test parameters were 392N, 600r / min, 75℃ and running time of 60 minutes.

[0101] According to ASTM D5183 "Standard Test Method for Determination of the Coefficient of Friction of Lubricants Using the Four-Ball Wear Test Machine", the average friction coefficient of different formulations was tested by an MRS-1J four-ball testing machine. The test parameters were load 392N, speed 600r / min, temperature 75°C, and running time 60 minutes.

[0102] According to SH / T 0847 "SRV testing machine method for determination of friction and wear properties of extreme pressure lubricants", the SRV average friction coefficient of different formulations was obtained by SRV friction testing machine test. The test parameters were load 50N, frequency 50Hz, running time 30min, temperature 40℃, and stroke 1mm.

[0103] Under the conditions of pump speed of 1500r / min and pump outlet pressure of 34.3MPa, 13L of the hydraulic oil to be tested was circulated through the plunger pump bench. The test temperature was 80℃. The oxidation life of the hydraulic oil was evaluated by the results of the change rate of the hydraulic oil's kinematic viscosity (40℃), the increase in acid value and the particle contamination degree, which did not exceed the last sample collection time corresponding to the deterioration standard.

[0104] Table 2 Performance parameters of anti-friction hydraulic oil composition

[0105]

[0106] It can be seen from Table 2 that the four-ball average friction coefficient and SRV average friction coefficient of Example 1 and Example 2 are significantly lower than the hydraulic oil prepared by using the existing hydraulic oil compound package, indicating that the anti-friction hydraulic oil composition provided by the present application has good anti-friction performance. After adding the polyol ester anti-friction agent, the contact form of the surface of the four-ball steel balls is changed, the friction coefficient between the friction pairs is reduced, and the shaking and creeping problem of the hydraulic cylinder caused by the excessive friction coefficient can be effectively improved.

[0107] The anti-friction hydraulic oil composition provided by the present invention has good anti-wear performance, anti-oxidation performance, anti-foaming performance, detergency, anti-rusting performance and oil-water separation performance, and can meet the rapidly developing hydraulic system's requirements for the hydraulic oil's antioxidant capacity, thermal oxidation stability, anti-foaming performance, cleanliness, corrosion resistance and other aspects.

[0108] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a friction-reducing hydraulic oil composition, characterized in that: The invention comprises the following components in mass fraction: 0.2%-2% of anti-wear agent, 0.2%-1% of antioxidant, 0.01%-0.08% of detergent, 0.2%-0.5% of metal passivator, 0.05%-0.5% of rust inhibitor, 0.01%-0.6% of anti-emulsifier, 0.01%-2% of wear reducer, 0.001%-0.1% of anti-foaming agent, and the balance is base oil; the wear reducer is a mixture of pentaerythritol monoester and pentaerythritol tetraester; the pentaerythritol monoester is pentaerythritol monooleate; the pentaerythritol tetraester is pentaerythritol tetraoleate; the mass ratio of pentaerythritol monooleate to pentaerythritol tetraoleate is 2:3; the preparation method of the wear reducer comprises: stirring pentaerythritol monooleate and pentaerythritol tetraoleate at 75°C for 3 hours to mix them uniformly; The anti-wear agent is a thiophosphate; the antioxidant is a mixture of 2,6-di-tert-butyl-p-cresol and butyl octyl diphenylamine; the detergent is sulfurized alkyl phenate calcium; the rust inhibitor is dinonyl sulfonic acid calcium salt; the metal passivator is a methyl benzotriazole derivative; the demulsifier is a polyether; the anti-foaming agent is dimethyl silicone oil; the base oil is a base oil of API Class II or above; The preparation method comprises: adding anti-wear agent, antioxidant, detergent, metal passivator, rust inhibitor, anti-emulsifier, anti-friction agent and base oil into a blending container in proportion, heating to about 50°C under normal pressure, stirring for 1 hour, and finally adding anti-foaming agent, continuing to stir for 4 hours until the mixture is completely dissolved; and then cooling the obtained mixture to obtain the anti-friction hydraulic oil composition.

2. A friction-reducing hydraulic oil composition, characterized in that: Prepared by the method of claim 1.

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