Lubricating oil composition for improving friction characteristic of gear and preparation method of lubricating oil composition

Abstract

The invention discloses a lubricating oil composition for improving the friction characteristic of a gear and a preparation method thereof. The lubricating oil composition comprises the following raw materials in parts by weight: 81-95 parts of base oil, 1-4 parts of a gear oil complexing agent, 1-10 parts of a viscosity index improver and 2-5 parts of a friction improved dispersant. The friction-improved dispersant is introduced into the lubricating oil for the gear, so that the problem that the conventional friction-improved dispersant competitively adsorbs with other additives on a metal surface to generate adverse effects on the friction characteristics of an oil product is solved; in addition, the introduction of the substance can effectively adsorb and disperse oil sludge, paint film and other sediments in the oil product, prevents the sediments from gathering and depositing to cause frictional wear, further improves the oxidation stability of the vehicle gear oil, and prolongs the service life of the vehicle gear oil. The prepared lubricating oil composition for the gear has excellent friction characteristics, can effectively improve the friction characteristics of transmission oil, and improves the friction characteristics and gear shifting smoothness of an automobile transmission.

Description

Technical Field

[0001] The invention relates to a lubricating oil composition for improving the friction characteristics of gears and a preparation method thereof. Background Art

[0002] High-efficiency shifting in manual transmissions is usually achieved using synchronizers. As the main component of automotive gear transmissions, synchronizers allow two gears with different speeds to undergo a friction contact process between the friction pairs before meshing, so that the two gears quickly reach and maintain the same circumferential speed before meshing and achieving synchronization, thereby effectively eliminating the impact between gears during shifting. Under high-temperature operating conditions, the highly active additives in transmission oil are easily oxidized and decomposed to produce a large amount of sludge, paint film and sediment. With the continuous accumulation of sludge and sediment, the system temperature further increases, aggravating the aging and deterioration of the oil, affecting the smoothness of shifting, and also causing corrosion to the copper alloy in the transmission, ultimately affecting the life of the transmission.

[0003] Dispersants can absorb and disperse deposits such as sludge and paint film in oil products, prevent them from agglomerating and depositing to cause friction and wear, and improve the oxidation stability and life of vehicle gear oil. Therefore, they are widely used in gear oil formulations. Reference patents such as US201862613589, US2016075964A1, US8697617B2, US201615094478, etc. all use conventional dispersants to improve the dispersion performance of oil products. However, the amines in conventional dispersants are highly active. Highly active amines in oil products will form competitive adsorption with other additives on the metal surface, which will have an adverse effect on the friction characteristics of the oil products, thereby causing the shifting flexibility of the synchronizer to deteriorate and shortening its service life. Summary of the invention

[0004] In order to increase the selection space of lubricating oil for gears and at least partially solve the problems of poor shifting compliance and shortened service life of automobile transmissions, an embodiment of the present invention provides a lubricating oil composition for improving gear friction characteristics and a preparation method thereof.

[0005] As one aspect of the present invention, a lubricating oil composition for improving the friction characteristics of gears is provided. The lubricating oil composition comprises the following constituent raw materials, measured by weight: 81 to 95 parts of base oil, 1 to 4 parts of gear oil compound, 1 to 10 parts of viscosity index improver and 2 to 5 parts of friction improving dispersant.

[0006] In one or some possible embodiments, the base oil is selected from one or more of Group I base oil, Group II base oil, Group III base oil, poly α-olefin synthetic oil, ester synthetic oil or polyether synthetic oil.

[0007] In one or some possible embodiments, the gear oil compound comprises: an extreme pressure agent, an anti-wear agent, a rust inhibitor and a metal deactivator;

[0008] The mass ratio of the extreme pressure agent, the anti-wear agent, the rust inhibitor and the metal deactivator is (85-96): (3-15): (0.5-5): (0.5-5).

[0009] In one or some possible embodiments, the extreme pressure agent is selected from sulfided isobutylene, or a mixture of sulfided isobutylene and dialkyl pentasulfide in any ratio, or a mixture of sulfided isobutylene and di-tert-butyl polysulfide in any ratio.

[0010] In one or some possible embodiments, the antiwear agent is selected from one or more of phosphate ammonium salts, thiophosphate amine salts, dialkyl phosphite ammonium salts, 2,5-dimercaptothiadiazole ammonium salts, benzotriazole ammonium salts or benzotriazole thiophosphate ammonium salts.

[0011] In one or some possible embodiments, the rust inhibitor is selected from dioctyl phosphate oleic acid amine, dicyclohexyl phosphate oleic acid amine, dioctadecyl phosphate oleic acid amine, C 12 Fatty acid diethanolamide phosphate, C 14 Fatty acid diethanolamide phosphate, C 16 Fatty acid diethanolamide phosphate or C 18 One or more of fatty acid diethanolamide phosphates.

[0012] In one or some possible embodiments, the metal deactivator is selected from thiadiazole polysulfide or a derivative of thiadiazole polysulfide.

[0013] In one or some possible embodiments, the viscosity index improver is polymethacrylate and / or ethylene propylene copolymer.

[0014] In one or some possible embodiments, the friction-modifying dispersant is represented by formula (I):

[0015]

[0016] In formula (I), R is -CH2-, -O- or -SO2-; R1 is -CH2-, -CH2CH2-, -CH(CH3)- or -CH(OH)-; R2, R3, R4, and R5 are each independently selected from mono-hanging fatty amine type polyisobutylene succinimide B and / or mono-hanging polyether amine type polyisobutylene succinimide C.

[0017] In one or some possible embodiments, the mono-hanging fatty amine type polyisobutylene succinimide B is as shown in formula (II):

[0018]

[0019] In formula (II), the value range of n is 1≤n≤8, and n is an integer.

[0020] In one or some possible embodiments, the mono-hedral polyetheramine type polyisobutylene succinimide C is as shown in formula (III):

[0021]

[0022] In formula (III), the value range of x and z is 1≤(x+z)≤4, and x and z are both integers; the value range of y is 1≤y≤9, and y is an integer.

[0023] As another aspect of the present invention, it relates to a method for preparing the lubricating oil composition for improving the friction characteristics of gears, the method comprising the following steps:

[0024] S1. Preparation of gear oil compound

[0025] Under stirring conditions, weighing and mixing the extreme pressure agent, anti-wear agent, rust inhibitor and metal deactivator in order by mass, heating and mixing, and preparing a gear oil compound;

[0026] S2. Preparation of lubricating oil composition

[0027] Under stirring conditions, the base oil, the gear oil compound prepared in step S1, the viscosity index improver and the friction improving dispersant are weighed and mixed in order by mass, and heated and mixed to obtain a lubricating oil composition.

[0028] In one or some possible embodiments, the friction-modifying dispersant is a compound prepared by Mannich reaction of a multifunctional polar crosslinker A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B and / or the mono-hanging polyether amine type polyisobutylene succinimide C, and a polyformaldehyde compound D.

[0029] In one or some possible embodiments, the friction-modifying dispersant is a compound prepared by a Mannich reaction of a multifunctional polar crosslinking agent A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B, the mono-hanging polyether amine type polyisobutylene succinimide C and a polyformaldehyde compound D;

[0030] The molar ratio of the multifunctional polar crosslinking agent A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B, the mono-hanging polyether amine type polyisobutylene succinimide C and the polyformaldehyde compound D is 1:(1-4):(1-4):(3.5-4.2).

[0031] The method for preparing the lubricating oil composition also includes the preparation of a friction-modifying dispersant;

[0032] The method for preparing the friction-modifying dispersant comprises the following steps:

[0033] Under stirring conditions, the multifunctional polar crosslinking agent A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B, the mono-hanging polyether amine type polyisobutylene succinimide C and the polyformaldehyde compound D are heated and mixed according to the molar ratio, and then water is removed, the temperature is reduced and filtered to obtain a friction-modifying dispersant.

[0034] In one or some possible embodiments, the multifunctional polar crosslinking agent A containing multiple reaction sites is as shown in formula (IV):

[0035]

[0036] In formula (IV), R is -CH2-, -O- or -SO2-; R1 is -CH2-, -CH2CH2-, -CH(CH3)- or -CH(OH)-.

[0037] In one or some possible embodiments, the preparation of the multifunctional polar crosslinking agent A containing multiple reaction sites comprises the following steps:

[0038] The aromatic amine compound, the carboxyl-containing phenolic compound and the organic solvent are heated and mixed under stirring, refluxed under the protection of an inert gas, filtered, and distilled under reduced pressure to obtain the multifunctional polar crosslinking agent A containing multiple reaction sites.

[0039] In one or some possible embodiments, the molar ratio of the aromatic amine compound to the carboxyl-containing phenol compound is 1:(1.8-2.3).

[0040] In one or some possible embodiments, the aromatic amine compound is as shown in formula (V):

[0041]

[0042] In formula (V), R is -CH2-, -O- or -SO2-.

[0043] In one or some possible embodiments, the carboxyl-containing phenolic compound is selected from one or more of p-hydroxybenzoic acid, p-hydroxyphenylacetic acid, p-hydroxyphenylpropionic acid, 2-(4-hydroxyphenyl)propionic acid, 3-hydroxyphenylethanic acid, 2-(p-hydroxyphenylazo)benzoic acid or 2-amino-5-hydroxybenzoic acid.

[0044] In one or some possible embodiments, the preparation of the mono-hanging fatty amine type polyisobutylene succinimide B comprises the following steps:

[0045] Under stirring conditions, the polyethylene polyamine compound and the base oil are heated and mixed, and then polyisobutylene succinic anhydride is added, the temperature is raised for reaction, water is removed, and the mono-hanging fatty amine type polyisobutylene succinimide B is obtained by cooling.

[0046] In one or some possible embodiments, the molar ratio of the polyisobutylene succinic anhydride to the polyethylene polyamine compound is 1:(0.8-1).

[0047] In one or some possible embodiments, the number average molecular weight of the polyisobutylene succinic anhydride is selected from 1000, 1300 or 2300.

[0048] In one or some possible embodiments, the polyethylene polyamine compound is selected from one or more of diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine or heavy polyamines.

[0049] In one or some possible embodiments, the mass fraction of the base oil in the mono-hydroxylated fatty amine type polyisobutylene succinimide B is 50-65%.

[0050] In one or some possible embodiments, the preparation of the mono-hedral polyetheramine type polyisobutylene succinimide C comprises the following steps:

[0051] Under stirring conditions, the polyetheramine compound and the base oil are heated and mixed, and then polyisobutylene succinic anhydride is added, the temperature is raised for reaction, water is removed, and the mono-hanging polyetheramine type polyisobutylene succinimide C is obtained by cooling.

[0052] In one or some possible embodiments, the molar ratio of the polyisobutylene succinic anhydride to the polyetheramine compound is 1:(0.75-1).

[0053] In one or some possible embodiments, the mass fraction of the base oil in the mono-peptide polyetheramine polyisobutylene succinimide C is 45-55%.

[0054] The present invention introduces a friction-modifying dispersant into the gear lubricating oil, solving the problem that conventional dispersants compete with other additives for adsorption on the metal surface and adversely affect the friction characteristics of the oil. In addition, the friction-modifying dispersant has excellent dispersibility, oxidation resistance and high-temperature detergency. The introduction of this substance can effectively adsorb and disperse sediments such as sludge and paint film in the oil, prevent their aggregation and deposition to cause friction and wear, and further improve the oxidation stability and life of vehicle gear oil.

[0055] The gear lubricating oil composition prepared by the present invention has excellent friction properties, can effectively improve the friction properties of transmission oil, and improves the friction properties and gear shifting smoothness of synchronizers in automobiles.

[0056] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 The figure is a trend chart showing the change of the friction coefficient of the lubricating oil composition prepared in Application Examples 1 to 4 and Comparative Examples 1 to 2 of the present invention with the test time. DETAILED DESCRIPTION

[0057] The following is a detailed description of the embodiments of the present invention: The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following embodiments. The process parameters for which specific conditions are not specified in the following embodiments are generally based on conventional conditions.

[0058] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0059] The present invention is further described below in conjunction with specific examples, and the protection scope of the present invention is not limited by the following examples. The sources of materials mainly involved in the examples are all conventional commercial products.

[0060] The following are preparation examples of the present invention, and the preparation examples provide the preparation processes and products of the multifunctional polar crosslinker A containing multiple reaction sites, the single-hanging fat-type polyisobutylene succinimide B, and the single-hanging polyetheramine-type polyisobutylene succinimide C.

[0061] (1) Preparation of multifunctional polar crosslinker A containing multiple reactive sites

[0062] Preparation Example 1

[0063] Under stirring conditions, 59.4 g of 4,4'-diaminodiphenylmethane, 91.2 g of p-hydroxyphenylacetic acid and 100 g of xylene were mixed at 130°C, nitrogen was introduced, refluxed for 4 h, filtered, and distilled under reduced pressure to obtain a multifunctional polar crosslinking agent A1 containing multiple reaction sites.

[0064] The multifunctional polar cross-linking agent A1 containing multiple reaction sites is as follows:

[0065]

[0066] Preparation Example 2

[0067] Under stirring conditions, 60 g of 3,4'-diaminodiphenyl ether, 82.8 g of p-hydroxybenzoic acid and 100 g of xylene were mixed at 133°C, nitrogen was introduced, refluxed for 3 h, filtered, and distilled under reduced pressure to obtain a multifunctional polar crosslinking agent A2 containing multiple reaction sites.

[0068] The multifunctional polar cross-linking agent A2 containing multiple reaction sites is as follows:

[0069]

[0070] Preparation Example 3

[0071] Under stirring conditions, 74.4 g of 4,4'-diaminodiphenyl sulfone, 99.6 g of p-hydroxyphenylpropionic acid and 100 g of xylene were mixed at 138°C, nitrogen was introduced, refluxed for 3 h, filtered, and distilled under reduced pressure to obtain a multifunctional polar crosslinking agent A3 containing multiple reaction sites.

[0072] The multifunctional polar cross-linking agent A3 containing multiple reaction sites is as follows:

[0073]

[0074] (2) Preparation of mono-heptyl fatty amine type polyisobutylene succinimide B

[0075] Preparation Example 4

[0076] Under stirring conditions, 23.2 g of heavy polyamine (Huntsman E100) and 123.2 g of base oil Y4 were mixed at 102 ° C, and then 115 g of polyisobutylene succinic anhydride PIBSA-1000 was added. The feeding time was controlled to be 1 h. After the feeding was completed, the mixture was kept warm for 3 h, and then the temperature was raised to 160 ° C at a rate of 10 ° C / h. Nitrogen was introduced into the system, and water was removed by gas stripping for 6 h. The mono-hanging fatty amine type polyisobutylene succinimide B1 was obtained after cooling.

[0077] Preparation Example 5

[0078] Under stirring conditions, 11.6 g of polyethylene polyamine (E100) and 190 g of base oil 100SN were mixed at 110°C, and then 115 g of polyisobutylene succinic anhydride PIBSA-2300 was added. The addition time was controlled to be 1 h. After the addition was completed, the mixture was kept warm for 2 h, and then the temperature was raised to 150°C at a rate of 8°C / h. Nitrogen was introduced into the system, and water was removed by gas stripping for 4 h. The mono-hanging fatty amine type polyisobutylene succinimide B2 was obtained after cooling.

[0079] (3) Single hanging polyetheramine type polyisobutylene succinimide C

[0080] Preparation Example 6

[0081] Under stirring conditions, 60g of polyether diamine ( ED-600) and 160g base oil Y4 were mixed at 110°C, and then 100g polyisobutylene succinic anhydride PIBSA-1300 was added, and the feeding time was controlled to be 30min. After the feeding was completed, the reaction was carried out at 120°C for 3h, and then the temperature was raised to 160°C. Nitrogen was introduced into the system, and water was removed by gas stripping for 6h. The mono-hedral polyetheramine type polyisobutylene succinimide C1 was obtained by cooling.

[0082] Preparation Example 7

[0083] Under stirring conditions, 36 g of polyether diamine ( ED-900) and 159g base oil MVI150 were mixed at 120°C, and then 92g polyisobutylene succinic anhydride PIBSA-2300 was added, and the feeding time was controlled to be 30min. After the feeding was completed, the reaction was carried out at 130°C for 2h, and then the temperature was raised to 170°C. Nitrogen was introduced into the system, and water was removed by gas stripping for 5h. The mono-hedral polyetheramine type polyisobutylene succinimide C2 was obtained by cooling.

[0084] The following are examples of the present invention.

[0085] Examples 1 to 12 each provide a friction modifying dispersant.

[0086] Example 1

[0087] Under stirring conditions, 46.6 g of the multifunctional polar cross-linking agent A1 containing multiple reaction sites of Preparation Example 1, 492.8 g of the single-hanging fatty amine type polyisobutylene succinimide B1 of Preparation Example 4, 581.8 g of the single-hanging polyether amine type polyisobutylene succinimide C1 of Preparation Example 6 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 7°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 4 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL1.

[0088] Example 2

[0089] Under stirring conditions, 46.6 g of the multifunctional polar cross-linking agent A1 containing multiple reaction sites of Preparation Example 1, 492.8 g of the single-hanging fatty amine type polyisobutylene succinimide B1 of Preparation Example 4, 1300 g of the single-hanging polyether amine type polyisobutylene succinimide C2 of Preparation Example 7 and 36 g of polyformaldehyde were mixed. After 2 hours, the temperature was raised to 110°C at a rate of 10°C / h. After 4 hours, the temperature was raised to 160°C, nitrogen was introduced into the system, and water was removed by air stripping for 6 hours. After cooling to 145°C, diatomaceous earth filter aid was used for filtration to obtain a friction-modified dispersant SSL2.

[0090] Example 3

[0091] Under stirring conditions, 46.6 g of the multifunctional polar cross-linking agent A1 containing multiple reaction sites of Preparation Example 1, 1266 g of the single-hanging fatty amine type polyisobutylene succinimide B2 of Preparation Example 5, 581.8 g of the single-hanging polyether amine type polyisobutylene succinimide C1 of Preparation Example 6 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL3.

[0092] Example 4

[0093] Under stirring conditions, 46.6 g of the multifunctional polar cross-linking agent A1 containing multiple reaction sites of Preparation Example 1, 1266 g of the single-hanging fatty amine type polyisobutylene succinimide B2 of Preparation Example 5, 1300 g of the single-hanging polyether amine type polyisobutylene succinimide C2 of Preparation Example 7 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL4.

[0094] Example 5

[0095] Under stirring conditions, 46.8 g of the multifunctional polar cross-linking agent A2 containing multiple reaction sites of Preparation Example 2, 492.8 g of the single-hanging fatty amine type polyisobutylene succinimide B1 of Preparation Example 4, 581.8 g of the single-hanging polyether amine type polyisobutylene succinimide C1 of Preparation Example 6 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL5.

[0096] Example 6

[0097] Under stirring conditions, 46.8 g of the multifunctional polar cross-linking agent A2 containing multiple reaction sites of Preparation Example 2, 492.8 g of the single-hanging fatty amine type polyisobutylene succinimide B1 of Preparation Example 4, 1300 g of the single-hanging polyether amine type polyisobutylene succinimide C2 of Preparation Example 7 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, diatomaceous earth filter aid was used for filtration to obtain a friction-modified dispersant SSL6.

[0098] Example 7

[0099] Under stirring conditions, 46.8 g of the multifunctional polar cross-linking agent A2 containing multiple reaction sites of Preparation Example 2, 1266 g of the single-hanging fatty amine type polyisobutylene succinimide B2 of Preparation Example 5, 581.8 g of the single-hanging polyether amine type polyisobutylene succinimide C1 of Preparation Example 6 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, diatomaceous earth filter aid was used for filtration to obtain a friction-modified dispersant SSL7.

[0100] Example 8

[0101] Under stirring conditions, 46.8 g of the multifunctional polar cross-linking agent A2 containing multiple reaction sites of Preparation Example 2, 1266 g of the single-hanging fatty amine type polyisobutylene succinimide B2 of Preparation Example 5, 1300 g of the single-hanging polyether amine type polyisobutylene succinimide C2 of Preparation Example 7 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, diatomaceous earth filter aid was used for filtration to obtain a friction-modified dispersant SSL8.

[0102] Example 9

[0103] Under stirring conditions, 51.6 g of the multifunctional polar cross-linking agent A3 containing multiple reaction sites of Preparation Example 3, 492.8 g of the single-hanging fatty amine type polyisobutylene succinimide B1 of Preparation Example 4, 581.8 g of the single-hanging polyether amine type polyisobutylene succinimide C1 of Preparation Example 6 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL9.

[0104] Example 10

[0105] Under stirring conditions, 51.6 g of the multifunctional polar cross-linking agent A3 containing multiple reaction sites of Preparation Example 3, 492.8 g of the single-hanging fatty amine type polyisobutylene succinimide B1 of Preparation Example 4, 1300 g of the single-hanging polyether amine type polyisobutylene succinimide C2 of Preparation Example 7 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL10.

[0106] Embodiment 11

[0107] Under stirring conditions, 51.6 g of the multifunctional polar cross-linking agent A3 containing multiple reaction sites of Preparation Example 3, 1266 g of the single-hanging fatty amine type polyisobutylene succinimide B2 of Preparation Example 5, 581.8 g of the single-hanging polyether amine type polyisobutylene succinimide C1 of Preparation Example 6 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, diatomaceous earth filter aid was used for filtration to obtain a friction-modified dispersant SSL11.

[0108] Example 12

[0109] Under stirring conditions, 51.6 g of the multifunctional polar cross-linking agent A3 containing multiple reaction sites of Preparation Example 3, 1266 g of the single-hanging fatty amine type polyisobutylene succinimide B2 of Preparation Example 5, 1300 g of the single-hanging polyether amine type polyisobutylene succinimide C2 of Preparation Example 7 and 36 g of polyformaldehyde were mixed. After 1 hour, the temperature was raised to 110°C at a rate of 10°C / h. After 3 hours, the temperature was raised to 150°C, nitrogen was introduced into the system, and water was removed by air stripping for 5 hours. After cooling to 130°C, filtration was performed using a diatomaceous earth filter aid to obtain a friction-modified dispersant SSL12.

[0110] Examples 13 to 16 each provide a gear oil compound.

[0111] Embodiment 13

[0112] The composition and mass fraction of the gear oil compound SSL13 of this embodiment are shown in Table 1 below:

[0113] Table 1 Composition and quality of gear oil compound

[0114] type Components Mass fraction / % Extreme Pressure Agents Sulfurized isobutylene 87 Antiwear Agents Ammonium dodecyl phosphate 8 Rust inhibitor Dicyclohexyl phosphate oleylamine 3.6 Metal deactivator Tolyltriazole 1.4

[0115] Embodiment 14

[0116] The composition and quality of the gear oil compound SSL14 of this embodiment are shown in Table 2 below:

[0117] Table 2 Composition and quality of gear oil compound

[0118]

[0119]

[0120] Embodiment 15

[0121] The composition and quality of the gear oil compound SSL15 of this embodiment are shown in Table 3 below:

[0122] Table 3 Composition and quality of gear oil compound

[0123] type Components Mass / g Extreme Pressure Agents High pressure sulfurized isobutylene 87 Antiwear agent 1 Ammonium dodecyl phosphate 4 Antiwear agent 2 2,5-Dimercaptothiazolium ammonium salt 2 Antiwear agent 3 Benzotriazole ammonium salt 2 Rust inhibitor Dicyclohexyl phosphate oleylamine 3.6 Metal deactivator Tolyltriazole 1.4

[0124] Example 16

[0125] The composition and quality of the gear oil compound SSL16 of this embodiment are shown in Table 4 below:

[0126] Table 4 Composition and quality of gear oil compound

[0127] type Components Mass / g Extreme Pressure Agents Sulfurized isobutylene 87 Antiwear agent 1 Ammonium dodecyl phosphate 5 Antiwear agent 2 2,5-Dimercaptothiazolium ammonium salt 1.5 Antiwear agent 3 Benzotriazole ammonium salt 1.5 Rust inhibitor Dicyclohexyl phosphate oleylamine 3.5 Metal deactivator Tolyltriazole 1.5

[0128] The following are application examples of the present invention, each of which provides a lubricating oil composition for improving the friction characteristics of gears. In the following application examples, the lubricating oil composition for improving the friction characteristics of gears is prepared by the following steps:

[0129] S1. Preparation of gear oil compound

[0130] First, the required weight portions of extreme pressure agent, anti-wear agent, rust inhibitor and metal deactivator are measured by weighing equipment respectively, and poured into a mixing and stirring equipment in sequence, and stirred at 30-35°C for 1-2 hours to mix evenly, thus obtaining a gear oil compound;

[0131] S2. Preparation of friction-modifying dispersants

[0132] The preparation method of the substance refers to Examples 1 to 12.

[0133] S3. Preparation of lubricating oil composition

[0134] First, the required weight portions of base oil, the gear oil compound prepared in step S1, the viscosity index improver and the friction improving dispersant are measured by a weighing device, and poured into a mixing and stirring device in sequence, and stirred at a temperature of 60-70° C. for 2-3 hours to mix evenly, thereby obtaining a lubricating oil composition.

[0135] Application Example 1

[0136] The lubricating oil composition for improving the friction characteristics of gears prepared in this application example includes the constituent raw materials and mass fractions shown in Table 5 below:

[0137] Table 5 Constituent materials and mass fractions of lubricating oil composition

[0138]

[0139]

[0140] Application Example 2

[0141] The lubricating oil composition for improving the friction characteristics of gears prepared in this application example includes the constituent raw materials and masses shown in Table 6 below:

[0142] Table 6 Composition of lubricating oil composition and mass fraction

[0143]

[0144] Application Example 3

[0145] The lubricating oil composition for improving the friction characteristics of gears prepared in this application example includes the constituent raw materials and masses shown in Table 7 below:

[0146] Table 7 Composition of lubricating oil composition and mass fraction

[0147]

[0148]

[0149] Application Example 4

[0150] The lubricating oil composition for improving the friction characteristics of gears prepared in this application example includes the constituent raw materials and masses shown in Table 8 below:

[0151] Table 8 Constituent raw materials and mass fractions of lubricating oil composition

[0152]

[0153] Application Comparative Example 1

[0154] The difference from Application Example 1 is that the friction-improving dispersant is a commercially available anti-wear ashless dispersant T151PB.

[0155] Application Comparative Example 2

[0156] The difference from Application Example 2 is that the friction-improving dispersant is a commercially available conventional high molecular weight ashless dispersant T161.

[0157] The following performance evaluations were conducted on the above Application Examples 1 to 4 and Application Comparative Examples 1 to 2, and the evaluation results are recorded in the following table.

[0158] Test 1 Evaluation of Antioxidant Properties

[0159] The high temperature oxidation ability of the gear lubricant composition is evaluated by the DKA oxidation test method (CEC L-48-A-00). The DKA oxidation test simulates the test conditions of 150-170°C and contact with air. By evaluating the changes in gear oil viscosity, acid value and sludge score, the antioxidant ability of the gear oil is measured. The smaller the change in gear oil viscosity and acid value, the lower the sludge grade, and the better the antioxidant ability of the oil. The specific steps are as follows:

[0160] In the test, 100 ml of oil sample was collected and placed in a glass tube, which was immersed in an oil bath at 120°C. A condenser was connected to the top of the glass tube, and a certain amount of air was blown into the lubricating oil. The test time was 192 hours. The test results are recorded in Table 9 below.

[0161] Table 9DKA oxidation test results

[0162]

[0163] The test results show that after the friction-modifying dispersant provided by the present invention is applied to gear lubricating oil, the oil maintains a low viscosity increase and acid value increase, and the sludge level is low, indicating that it can effectively inhibit the oxidative decay of the oil, so that the oil has good antioxidant properties.

[0164] Test 2 Friction Characteristics Analysis

[0165] (1) Four-ball friction machine test

[0166] The maximum no-seizure load (PB value) is determined according to the relevant methods in GB / T 3142-1982 "Determination of lubricant load-bearing capacity (four-ball method)";

[0167] Among them, when conducting the four-ball friction machine test, the change trend of the oil friction factor with the test time is as follows: Figure 1 shown.

[0168] (2) SRV friction and wear test

[0169] The SRV4 high-frequency reciprocating linear vibration tester produced by OPTIMOL of Germany was used to measure the wear spot diameter of the oil test piece according to the relevant methods recorded in the industry standard NB / SH / T 0847 "SRV tester method for friction and wear determination of extreme pressure lubricating oil". The wear spot diameter and the maximum friction coefficient, minimum friction coefficient, and friction coefficient at different time points were measured under constant conditions using the upper and lower test piece copper disks in surface-to-surface contact to evaluate the wear and friction performance of manual transmission oil. The test conditions are: load 250N, frequency 50Hz, time 2h, temperature 80℃, and stroke 1mm.

[0170] The test results of the above two tests are recorded in Table 10 below.

[0171] Table 10 Friction characteristics analysis

[0172]

[0173] The test results show that, on the one hand, the friction coefficient of the lubricating oil composition provided by the present invention does not change significantly with the test time, indicating that it has good retention and stability and good friction properties; on the other hand, the maximum no-seizure load of the lubricating oil composition provided by the present invention is high and the average wear spot diameter is small, indicating that it has good extreme pressure and anti-wear properties.

[0174] In summary, the lubricating oil composition provided by the present invention has excellent oxidation resistance, extreme pressure and anti-wear properties, and friction characteristics.

[0175] The above are only preferred feasible embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Various modifications or applications made according to the above embodiments are within the protection scope of this technical solution.

[0176] Although the specific embodiments of the present invention have been described in detail, it will be understood by those skilled in the art. According to all the teachings disclosed, various modifications and replacements can be made to those details, and these changes are all within the protection scope of the present invention. The full scope of the present invention is given by the attached claims and any equivalents thereof.

Claims

1. A lubricating oil composition for improving the friction characteristics of gears, characterized in that: The lubricating oil composition comprises the following raw materials by weight: 81-95 parts of base oil, 1-4 parts of gear oil compounding agent, 1-10 parts of viscosity index improver and 2-5 parts of friction improving dispersant.

2. The lubricating oil composition for improving the friction characteristics of gears according to claim 1, characterized in that: The base oil is selected from one or more of Group I base oil, Group II base oil, Group III base oil, poly-α-olefin synthetic oil, ester synthetic oil or polyether synthetic oil.

3. The lubricating oil composition for improving the friction characteristics of gears according to claim 1, characterized in that: The gear oil compound comprises: an extreme pressure agent, an anti-wear agent, a rust inhibitor and a metal deactivator; The mass ratio of the extreme pressure agent, the anti-wear agent, the rust inhibitor and the metal deactivator is (85-96): (3-15): (0.5-5): (0.5-5).

4. The lubricating oil composition for improving the friction characteristics of gears according to claim 3, characterized in that: The extreme pressure agent is selected from sulfided isobutylene, or a mixture of sulfided isobutylene and dialkyl pentasulfide in any ratio, or a mixture of sulfided isobutylene and di-tert-butyl polysulfide in any ratio.

5. The lubricating oil composition for improving the friction characteristics of gears according to claim 3, characterized in that: The anti-wear agent is selected from one or more of phosphate ammonium salts, thiophosphate amine salts, dialkyl phosphite ammonium salts, 2,5-dimercaptothiadiazole ammonium salts, benzotriazole ammonium salts or benzotriazole thiophosphate ammonium salts.

6. The lubricating oil composition for improving the friction characteristics of gears according to claim 3, characterized in that: The rust inhibitor is selected from dioctyl phosphate oleic acid amine, dicyclohexyl phosphate oleic acid amine, dioctadecyl phosphate oleic acid amine, C 12 Fatty acid diethanolamide phosphate, C 14 Fatty acid diethanolamide phosphate, C 16 Fatty acid diethanolamide phosphate or C 18 One or more of fatty acid diethanolamide phosphates.

7. The lubricating oil composition for improving the friction characteristics of gears according to claim 3, characterized in that: The metal deactivator is selected from thiadiazole polysulfide or a derivative of thiadiazole polysulfide.

8. The lubricating oil composition for improving the friction characteristics of gears according to claim 1, characterized in that: The viscosity index improver is polymethacrylate and / or ethylene propylene copolymer.

9. The lubricating oil composition for improving the friction characteristics of gears according to claim 1, characterized in that: The friction-modifying dispersant is shown in formula (I): In formula (I), R is -CH2-, -O- or -SO2-; R1 is -CH2-, -CH2CH2-, -CH(CH3)- or -CH(OH)-; R2, R3, R4, and R5 are each independently selected from mono-hanging fatty amine type polyisobutylene succinimide B and / or mono-hanging polyether amine type polyisobutylene succinimide C.

10. The lubricating oil composition for improving the friction characteristics of gears according to claim 9, characterized in that: The mono-hanging fatty amine type polyisobutylene succinimide B is as shown in formula (II): In formula (II), the value range of n is 1≤n≤8, and n is an integer.

11. The lubricating oil composition for improving the friction characteristics of gears according to claim 9, characterized in that: The mono-hedral polyetheramine type polyisobutylene succinimide C is as shown in formula (III): In formula (III), the value range of x and z is 1≤(x+z)≤4, and x and z are both integers; the value range of y is 1≤y≤9, and y is an integer.

12. A method for preparing a lubricating oil composition for improving gear friction characteristics as claimed in any one of claims 1 to 11, characterized in that: The method comprises the following steps: S1. Preparation of gear oil compound Under stirring conditions, weighing and mixing the extreme pressure agent, anti-wear agent, rust inhibitor and metal deactivator in order by mass, heating and mixing, and preparing a gear oil compound; S2. Preparation of lubricating oil composition Under stirring conditions, the base oil, the gear oil compound prepared in step S1, the viscosity index improver and the friction improving dispersant are weighed and mixed in order by mass, and heated and mixed to obtain a lubricating oil composition.

13. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 12, characterized in that: The friction-modifying dispersant is a compound prepared by a Mannich reaction of a multifunctional polar crosslinking agent A containing multiple reaction sites, the monohedral fatty amine type polyisobutylene succinimide B and / or the monohedral polyether amine type polyisobutylene succinimide C, and a polyformaldehyde compound D.

14. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 13, characterized in that: The friction-modifying dispersant is a compound prepared by a Mannich reaction of a multifunctional polar crosslinking agent A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B, the mono-hanging polyether amine type polyisobutylene succinimide C and a polyformaldehyde compound D; The molar ratio of the multifunctional polar crosslinking agent A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B, the mono-hanging polyether amine type polyisobutylene succinimide C and the polyformaldehyde compound D is 1:(1-4):(1-4):(3.5-4.2).

15. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 14, characterized in that: The method for preparing the lubricating oil composition also includes the preparation of a friction-modifying dispersant; The method for preparing the friction-modifying dispersant comprises the following steps: Under stirring conditions, the multifunctional polar crosslinking agent A containing multiple reaction sites, the mono-hanging fatty amine type polyisobutylene succinimide B, the mono-hanging polyether amine type polyisobutylene succinimide C and the polyformaldehyde compound D are heated and mixed according to the molar ratio, and then water is removed, the temperature is reduced and filtered to obtain a friction-modifying dispersant.

16. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 15, characterized in that: The multifunctional polar cross-linking agent A containing multiple reaction sites is as shown in formula (IV): In formula (IV), R is -CH2-, -O- or -SO2-; R1 is -CH2-, -CH2CH2-, -CH(CH3)- or -CH(OH)-.

17. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 16, characterized in that: The preparation of the multifunctional polar cross-linking agent A containing multiple reaction sites comprises the following steps: The aromatic amine compound, the carboxyl-containing phenolic compound and the organic solvent are heated and mixed under stirring, refluxed under the protection of an inert gas, filtered, and distilled under reduced pressure to obtain the multifunctional polar crosslinking agent A containing multiple reaction sites.

18. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 17, characterized in that: The molar ratio of the aromatic amine compound to the carboxyl-containing phenol compound is 1:(1.8-2.3).

19. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 18, characterized in that: The aromatic amine compound is shown in formula (V): In formula (V), R is -CH2-, -O- or -SO2-.

20. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 18, characterized in that: The carboxyl-containing phenolic compound is selected from one or more of p-hydroxybenzoic acid, p-hydroxyphenylacetic acid, p-hydroxyphenylpropionic acid, 2-(4-hydroxyphenyl)propionic acid, 3-hydroxyphenylethanic acid, 2-(p-hydroxyphenylazo)benzoic acid or 2-amino-5-hydroxybenzoic acid.

21. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 15, characterized in that: The preparation of the monohedral fatty amine type polyisobutylene succinimide B comprises the following steps: Under stirring conditions, the polyethylene polyamine compound and the base oil are heated and mixed, and polyisobutylene succinic anhydride is added, the temperature is raised to react, water is removed, and the mono-hanging fatty amine type polyisobutylene succinimide B is obtained; The molar ratio of the polyisobutylene succinic anhydride to the polyethylene polyamine compound is 1:(0.8-1); The number average molecular weight of the polyisobutylene succinic anhydride is selected from 1000, 1300 or 2300; The polyethylene polyamine compound is selected from one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine or heavy polyamines; The mass fraction of the base oil in the mono-hydroxylated fatty amine type polyisobutylene succinimide B is 50-65%.

22. The method for preparing a lubricating oil composition for improving gear friction characteristics according to claim 15, characterized in that: The preparation of the mono-hung polyetheramine type polyisobutylene succinimide C comprises the following steps: Under stirring conditions, after heating and mixing the polyetheramine compound and the base oil, adding polyisobutylene succinic anhydride, heating to react, removing water, and cooling to obtain the mono-hanging polyetheramine type polyisobutylene succinimide C; The molar ratio of the polyisobutylene succinic anhydride to the polyetheramine compound is 1:(0.75-1); The mass fraction of the base oil in the mono-pendicular polyetheramine type polyisobutylene succinimide C is 45-55%.

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