KR100634102B1 - Lubricating grease compostion comprising alkyldiphenyl ether oil and diurea thickener - Google Patents

Abstract

The present invention is a lubricating grease composition for bearings used in high temperature, high speed, and high load environments, wherein the base oil has a molecular weight of 4,000 to 6,000, and has a kinematic viscosity of 40 to 90 to 120 cSt in an alkyldiphenyl ether. (alkyldiphenyl ether) oil, the content of diurea thickener (thiureer) in the grease composition is 20 to 30 wt%, the molecular formula of the diurea thickener is of the following structure,

In the above formula, R2 is an aromatic hydrocarbon group having 6 to 20 carbon atoms, R1 and R3 are composed of an aromatic hydrocarbon group having 6 to 15 carbon atoms and an alkyl group having 8 to 20 carbon atoms, and the aromatic hydrocarbon at R1 and R3 It provides a lubricating grease composition for bearings, characterized in that the ratio of 70 to 95 mole%. The lubricating grease composition for bearings provided above can be used at high temperatures, high speeds, high loads, and for a long time, and has an effect of preventing rust.

Lubricants for bearings, grease compositions

Description

Lubricating grease composition comprising alkyldiphenyl ether oil and diurea thickener

1 and 2 are views showing the structure of a bearing to which the grease composition of the present application is applied.

Explanation of symbols for main parts of the drawings

1: bearing outer ring 2: bearing inner ring

3: retainer 4: ball

5: rubber seal 6: grease injection space

Recently, the development and innovation of the mechanical technology has been made. Even during this technology development, there is a tendency to diversify and harsh use conditions in the application and application of mechanical parts, ie bearings. In particular, bearing greases applied to electronic components such as automotive alternators, electro-magnetic clutches, and idler-pulleys are gradually demanding high temperature, high speed, long life, and continuous performance improvement. In this regard, an object of the present invention is to provide a lubricating grease composition for bearings that can be used for high temperature, high speed, high load and long life.

Conventionally, lubricating greases, which have the performance of high-temperature, high-speed, and high-load bearings, are composed of polyalpha olefins as base oils in diurea thickeners containing cyclohexyl groups at their end groups. It was. However, typical diurea greases containing cyclohexyl groups soften when used under harsh conditions, such as high temperatures and high speeds, which can lead to premature increase in bearing leakage and cause bearing failure. In addition, polyalpha olefins used as base oils are difficult to satisfy a sufficient lubrication life in terms of thermal stability and oxidation stability.

Therefore, the bearing lubricating grease composition of the present application applies the diurea thickener which has an aromatic group to an end group, and uses the alkyldiphenyl ether oil excellent in thermal stability and oxidation stability as base oil, and it prevents early bearing damage as mentioned above. We tried to solve the problem.

It is an object of the present invention to provide a grease lubricating composition for ensuring a long life without rupture of bearings prematurely under high loads, as well as long term lubrication life at high temperatures and speeds. In addition, another object of the present application is to provide a lubricating grease composition that can solve the problem of rusting, since the lubricating grease may be applied to electrical components and may be affected by salt water or seawater.

The present invention relates to a lubricating grease composition for bearings having high temperature, high speed, high load and antirust performance.

The present application is an alkyldiphenylether oil having a molecular weight of 4,000 to 6,000, a kinematic viscosity in the range of 90 to 120 cSt at 40 ° C, and 20 to 30 wt% of a diurea thickener in the composition. Including as a range,

The molecular formula of the diurea thickener is as follows,

In the above formula, R2 is an aromatic hydrocarbon group having 6 to 20 carbon atoms, R1 and R3 are composed of an aromatic hydrocarbon group having 6 to 15 carbon atoms and an alkyl group having 8 to 20 carbon atoms, and the aromatic hydrocarbon at R1 and R3 It provides a lubricating grease composition for bearings used in high temperature, high speed and high load environment, characterized in that the ratio of 70 to 95 mole%.

The lubricating grease is assumed to have a No.1 to No. 3 range of the National Lubricating Grease Institute (NLGI) lead grade.

In addition, in order to improve the rust prevention performance, organo sulfonate, organite, nitrite, and nonionic surfactant having an HLB value of 1.5 to 10 may be added in an amount of 0.1 to 10 wt% based on the grease composition.

The grease of the above composition showed excellent performance under the harsh conditions of high temperature, high speed and high load in bearings applied to automotive electronic parts such as alternator, electro-magnetic clutch, idler-pulley, etc. Confirmed.

The alkyldiphenyl ether oil, which is a base oil used in the grease composition in the present invention, is obtained by addition reaction of 1 to 3 mol of polyalpha olefins having 10 to 22 carbon atoms and 1 mol of diphenyl ether.

This alkyldiphenyl ether oil is a colorless white liquid and has various properties depending on the number of moles and carbons of the alpha olefin. In particular, alkyldiphenyl ether oils have excellent properties as oils applied to rotary pump lubricating oil, seawater resistance oil, diffusion pump oil, and chain lubricating oil. In the grease composition of the present application, the kinematic viscosity of the alkyldiphenyl ether oil, which is a base oil, was limited to 90 to 120 cSt at 40 ° C., which resulted in premature failure of the bearing when the kinematic viscosity was lower than 90, whereas at higher temperatures than 120 cSt. This is because the stirring resistance and the torque value were large.

Although content of alkyldiphenyl ether oil is not limited to a specific range, 50 weight% or more content is preferable, and when using when temperature rises rapidly, it can use with more content for long time use. In this case, mineral oil, synthetic ester oil, synthetic hydrocarbon, phenyl ether oil can be added to the alkyldiphenyl ether oil.

The structural formula of the diurea compound as a thickener has been described above, and is generally obtained in the reaction between diisocyanate and monoamine. In the present application, the diurea compound is limited to having an aromatic group at the end, and is intended to minimize the initial leakage of the bearing at high temperature and high speed conditions. In addition, the insufficient fluidity of the thickener as a method to overcome the initial sticking The problem was solved by applying an alkyl group to the terminal group to compensate for the shortcomings.

The ratio of the aromatic hydrocarbon group in R1 and R3 is 70 to 95 mol%. The reason for limiting the molar ratio is that, when the molar ratio is less than 70 mol%, the fluidity of the grease may be large at high temperature, so that leakage may occur due to leakage, and in the case of more than 95 mol%, the actual fluidity may be reduced. This is because the initial chipping at high load may occur due to lack.

In addition, content of a diurea compound is 20-30 weight% with respect to the whole grease composition, and a grease-driven range means No.1-No.3. In other words, the principal value represents a value between 340 and 220. The numerical range is limited as described above because, if the content is less than No. 1 or the content is less than 20% by weight under high temperature and high speed, leakage may occur initially. This is because the stirring resistance and torque value at low temperatures are not advantageous. Therefore, for this reason, the content and the main value are preferably in the range of 24 wt% to 28 wt% and 310 to 250.

Examples of the diisocyanate used in the production of diurea include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate and naphthylene-1,5 -Compounds such as diisocyanate.

Examples of monoamines containing R1 and R3 include aromatic amines such as benzylamine, toluidine, chloro aniline, and the like, and aliphatic amines include octylamine, nonylamine, decylamine, dodecylamine, tridecylamine, tetra Decylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonyldecylamine, eicosylamine and the like.

In the present invention, an additive is added to the grease composition in order to improve the rust prevention performance. Organosulfonate, a water-insoluble additive, nitrite and a non-ionic surfactant, which are water-soluble aromatic additives, are added in an amount of 0.1 to 10% by weight, respectively, based on the total grease composition.

Organosulfonates can generally be expressed as RSO ₃ -M, for example RSO ₃ H as an acid comprising petroleum sulfonic acid and dinonylnaphthylenesulfonic acid. Alkali M is a metal as Ba, Ca, Zn, Pb, and metals such as Na, Li, NH4 ⁺ is water and the residual _{H 2 N (CH 2) 2} NH 2 amine. Sodium nitrite is industrially used with surfactants to improve oil dispersibility.

As the nonionic surfactant, glycerin fatty acid ester, polyglycerine fatty acid ester, sorbitan fatty acid ester, polyoxyethylene fatty acid ester having an HLB value of 1.5 to 9, and polyoxyethylene alkylphenyl ether may also be applied as the ether compound.

The effects of the rust preventive additives have been evaluated very well and have been provided in addition to the grease for bearings of automotive electronic parts. In addition, the grease compositions in this invention can be added with antioxidants, extreme pressure additives, oily enhancers and solid lubricants if necessary.

In the present invention, in the grease composition, an alkyldiphenyl ether oil having a kinematic viscosity in the range of 90 to 120 cSt at 40 ° C is basically used as the base oil, and the thickener in grease is 20 to 30 for the diurea thickener represented by the above-described molecular formula. It is used by content of weight%.

The grease composition is No. NLGI-led. 1 to No. Use the one in the range of 3. The use of grease compositions of this grade may have the effect of preventing the initial leakage of bearings under high temperature and high speed conditions, and has excellent lubrication characteristics to solve premature breakage and sticking under high loads and long lifespan. appear.

By adding rust preventive additives (organosulfonate, nitrite) and nonionic surfactants (HLB: 1.5 to 9) at 0.1 to 10 wt%, respectively, very excellent rust preventive performance can be exhibited. This effect will be described in more detail in the following examples.

In order to reduce the initial leakage under high temperature and high speed conditions, it is necessary to determine how much the amount of thickener should be. Since grease is a mixed reactant of liquid base oils and solid thickeners, greases with low content of thickeners tend to soften and leak. Comparing other urea type thickeners with soap-based thickeners, the urea type thickeners of the present invention were added in somewhat larger amounts having aromatic groups at the terminal groups. The aromatic group included in the urea thickener has excellent thermal stability, and when synthesized with alkyldiphenyl ether oil having excellent thermal stability and oxidative stability, it is excellent in high temperature and high speed conditions and can achieve long life.

In addition, it must be taken into account that the proper flow of grease is important to achieve lubrication life at high loads. It has been described above that the diurea thickener having an aromatic group in the terminal group can exhibit long life at high temperature and high speed conditions. However, at high loads, lubrication occurs early, resulting in shortened lubrication life. For this reason, it is considered that the flow flow of the grease is also worsened when the flow rate of the thickener of the grease is poor. In order to solve this problem, in the present invention, an alkyl group is applied to the diurea compound having an aromatic group in the terminal group, and the initial sticking is overcome with grease flow without loss of high temperature and high speed performance.

In the case of premature bearing failure, it is necessary to study the relationship between the type and amount of thickener and base oil and premature failure. Although both the metal-based and urea grease thickeners act as cushioning with the rolling surface of the bearing and the anti-abrasion effect, the urea grease of the present application has been observed to be particularly effective in the flaking properties in the bearings. In other words, the higher the thickener content, the lower the frequency of breakage than the lower one. The incidence of breakage was observed to be significantly reduced when the amount of thickener was greater than 24%.

In base oil, it was confirmed that breakage occurred in grease having a kinematic viscosity lower than 90 cSt at 40 ° C. This is thought to be caused by the increased contact between the bearing and the ball due to the small oil film in the boundary lubrication. Therefore, the present invention was to set the kinematic viscosity of the base oil to more than 90 cSt at 40 ℃ and to bring the effect of protecting the rolling surface of the bearing by the compound of the urea thickener in a ratio capable of forming a sufficient oil film. In order to further improve the rust preventive performance of grease, a satisfactory effect was obtained by adding an organosulfonate as a water-insoluble additive, a nitrite as a water-soluble rust preventive additive, and a nonionic surfactant.

According to the grease composition of the present invention, comparative evaluation was performed through the examples shown in Tables 1 to 8.

The performance evaluation of the grease-developed specimens was carried out by the following test method.

(1) High temperature, high speed leak test

Grease was filled in the bearings and the rotation test was carried out under the following conditions. Grease leakage before and after the test was calculated in weight percent.

-Test bearing: deep groove ball bearing

(Inner diameter Φ: 17 mm, outer diameter Φ: 40 mm, width: 12 mm, plastic cage, contact seal)

-Filling amount of grease: 1.0 ± 0.1g

RPM: 15,000 rpm

-Test temperature: 180 ℃

-Load: Fr 20 kgf Fa 30 kgf

(2) High temperature, high speed endurance life test

A lubrication life test of up to 1000 hours was conducted under the same conditions as in the test conditions (1).

(3) Heavy duty endurance and flaking test

Bearing samples (n = 5) were filled with grease samples and tested for up to 1,000 hours. The test bearings after the test were observed and evaluated for damage and sticking. Test conditions and methods are as follows.

-Test bearing: deep groove ball bearing

(Inner diameter Φ: 17 mm, outer diameter Φ: 40 mm, width: 12 mm, plastic cage, contact seal)

-Filling amount of grease: 2.0 ± 0.1g

RPM: 15,000 rpm

-Test temperature: 110 ℃

Load: Fr 300kgf

(4) Starting torque test

The starting torque test was carried out according to the KS M 2130 method, the test temperature was carried out at -40 ℃.

The standard values of the trial decision are as follows.

10,000 gfcm or less: Passed

10,000 gf · cm or more: fail

(5) Bearing antirust test

Bearing antirust test was carried out according to ASTM D 1743 and was determined according to the standard grade.

1. Examples 1 to 5, 7 to 10 and Comparative Examples 1 to 10

In each example, the base oil and the monoamine were reacted at 70-80 ° C. in a reaction vessel and a separation vessel, followed by stirring. The temperature increased due to the exothermic reaction during the reaction mixture, but the mixture was continuously stirred for about 30 minutes. (The cooling process was not performed.) The sufficiently reacted mixture was cooled after maintaining the temperature at 170 to 180 ° C for 30 minutes. Antirust additive was added as shown in the table, and 40 g of alkyldiphenylamine was added to the whole sample as an antioxidant. The final process was a 3-roll milling operation for grease homogenization.

2. Example 6

The proportion of base oil (550 g) and total p-toluidine were heated to 70-80 ° C. in the reaction vessel. The amount of the base oil (550 g) of the other ratio and the ratio of the entire TDI was reaction stirred at 70 ~ 80 ℃. The temperature of the reaction increased due to exothermic reaction. Stirring was continued for 30 minutes without cooling. The reacted mixture was kept at 170 to 180 ° C. for 30 minutes and then cooled. The rest of the base oil (140g) and the total octylamine was reacted at a temperature of 70 ~ 80 ℃. The remaining base oil (140g) was synthesized by reacting the total amount of MDI with a temperature of 70 ~ 80 ℃. The final reaction mixture was subjected to stirring, reaction and cooling. In addition, the additives shown in the table were added, and 40 g of alkyldiphenyl amine was added as an antioxidant. The final mixture was subjected to homogenization by 3-roll milling.

3. Comparative Example 11

Base oil (1400g) and lithium stearate (500.0g) were added to the reaction vessel and reacted with stirring until it completely dissolved at 230 ° C. After the reaction was cooled the antirust additive as shown in the table and 40 g of alkyldiphenylamine were added. The mixture was subjected to homogenization operation by 3-roll milling.

TDI shown in Tables 1-8 is an abbreviation of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate compound, and MDI is a symbol omitted from diphenylmethane-4,4'-diisocyanate. . As the alkyldiphenyl ether oil, kinematic viscosity of 97 cSt was used at 40 ° C., and polyalphaolefin was applied to PAO-A and PAT-B having kinematic viscosity of 400 cSt and 40 cSt at 40 ° C., respectively. Dinonylnaphthalene sulfonate was used as a sulfonate antirust additive. Sodium nitrite was used only for the fine passing through 100mesh. In addition, sodium nitrite contains a surfactant to ensure good dispersion in oil. According to the embodiment, the grease according to the present invention exhibits a low initial leakage and a long service life under high temperature and high speed conditions. In addition, no initial bearing failure was observed at high loads. It also shows good antirust performance.

In Comparative Example 1, sticking occurred at the initial stage under high load conditions, which is considered to be because only aromatics were used for the end group group of the diurea thickener. In Comparative Examples 2 to 4 having an aliphatic group in the terminal group and not composed of an aromatic group, leakage occurred initially at high temperature and high speed, and satisfactory lubrication life was not obtained. In Comparative Examples 3 and 4, where the amount of thickener of the urea type is relatively small, breakage is more likely to occur than in other Comparative Examples. Comparative Examples 7 and 8 using only polyalphaolefin as a base oil showed short lubrication life under high temperature and high speed conditions. Comparative Examples 5 and 10 showed inferior torque values at low temperatures, which are considered to be relatively hard because of high kinematic viscosity and low dominant values. On the contrary, if it is too soft as in Comparative Example 9, the initial leakage is large, the lubrication life is short, and breakage is observed. In Comparative Example 11 using a lithium thickener, leakage occurred at high temperature and high speed, and the lubrication life was also very small. In the bearing rust prevention test, inferior results were obtained only in Comparative Examples 5 to 6, and other examples showed good levels.

Table 1

Example 1 Example 2 Example 3 Example 4 Example 5 Thickener Diisocyanate TDI MDI  212.9-  220.8-  226.0-  226.8-  -260.4 Monoamine D-Toluidine Stearylamine Laurylamine Octylamine  243.6 31.5--  239.4-40.6-  250.4--33.6  192.8--101.4  180.8-77.8- Base oil Alkyldiphenyl ether poly-alpha-olefin A poly-alpha-olefin B 1,410-- 689.0 277.0 420.0 1,400.0-- 1,360.0-- 1,390.0-- Rust inhibitor Organo sulfonate (water insoluble) Ammonium Sulfonate 20.0 Ammonium Sulfonate 20.0 Ammonium Sulfonate 20.0 Zinc Sulfonate 20.0 Zinc Sulfonate 20.0 Night light (water soluble) Sodium Night Light 10.0 Sodium Night Light 20.0 Dispersion Sodium Night Light 10.0 Sodium Night Light 20.0 Dispersion Sodium Night Light 10.0 Nonionic Surfactant (HLB Value) Sorbitan Trioleate (1.8) 20.0 Sorbitan Trioleate (1.8) 20.0 Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (3.0) 20.0

Table 2

Example 1 Example 2 Example 3 Example 4 Example 5 Aromatic Hydrocarbon Ratios at R1 and R3 (mol%) 95 90 90 70 80 Amount of thickener (% by weight) 24.5 25.5 25.5 26.5 26.0 Dynamic viscosity (cSt) of base oil at 40 ℃ 97.0 94.0 97.0 97.0 97.0 NLGI rating 279 (No.2) 285 (No.2) 281 (No.2) 288 (No.2) 287 (No.2) Leakage at high temperature and high speed (% by weight) 6.0 7.2 6.7 8.1 7.1 Durability at high temperature and high speed 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) Durability and fracture resistance at high loads (n = 5) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) Starting torque at -40 ℃ pass pass pass pass pass Rust resistance of bearing pass pass pass pass pass

Table 3

Example 6 Example 7 Example 8 Example 9 Example 10 Thickener Diisocyanate TDI MDI  197.8 32.6  194.0-  213.7-  247.3-  261.3- Monoamine D-Toluidine Stearylamine Laurylamine Octylamine  245.6--33.0  217.0--29.0  232.7--30.6  273.8--35.9  223.8--114.9 Base oil Alkyldiphenyl ether poly-alpha-olefin A poly-alpha-olefin B 1,380.0-- 948.0 512.0- 1,432.0-- 1,351.0-- 640.0 270.0 390.0 Rust inhibitor Organo sulfonate (water insoluble) Zinc Sulfonate 20.0 Zinc Sulfonate 20.0 Barium sulfonate 10.0 Barium sulfonate 20.0 Barium sulfonate 20.0 Night light (water soluble) Sodium Night Light 20.0 Dispersion Sodium Night Light 20.0 Dispersion Sodium Night Light 10.0 Sodium Night Light 10.0 Sodium Night Light 20.0 Dispersion Nonionic Surfactant (HLB Value) Polyoxyethylene Ester (8.4) 20.0 Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (3.0) 20.0 Polyoxyethylene Ester (8.4) 20.0 Sorbitan Trioleate (1.8) 20.0

Table 4

Example 6 Example 7 Example 8 Example 9 Example 10 Aromatic Hydrocarbon Ratios at R1 and R3 (mol%) 95 90 90 90 70 Thickener amount (% by weight) 25.5 23.0 24.0 28.0 30.0 Dynamic viscosity at 40 ° C base oil (cSt) 97.0 150.0 97.0 97.0 94.0 NLGI rating 274 (No.2) 331 (No.1) 310 (No.1) 250 (No.3) 225 (No.3) Leakage at high temperature and high speed (% by weight) 6.7 14.7 8.1 6.2 6.0 Durability at high temperature and high speed 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) Durability and fracture resistance at high loads (n = 5) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) Starting torque at -40 ℃ pass pass pass pass pass Rust resistance of bearing pass pass pass pass pass

Table 5

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Thickener Diisocyanate TDI MDI 220.6- 221.7- -168.6 -110.2 228.0- Monoamine D-Toluidine CHA Octylamine  269.4--  135.6-162.7  -133.4-  --112.8  251.4-33.6 Base oil Alkyldiphenyl ether poly-alpha-olefin A poly-alpha-olefin B 1,410-- 1,390.0-- 1,600.0-- 1,690.0-- 695.0 695.0- Rust inhibitor Organo sulfonate (water insoluble) Ammonium Sulfonate 20.0 Zinc Sulfonate 20.0 Zinc Sulfonate 20.0 Barium sulfonate 20.0 - Night light (water soluble) Sodium Night Light 10.0 Sodium Night Light 10.0 Sodium Night Light 20.0 Dispersion Sodium Night Light 10.0 Sodium Night Light 30.0 Dispersion Nonionic Surfactant (HLB Value) Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (1.8) 20.0 Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (3.0) 20.0

Table 6

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Aromatic Hydrocarbon Ratios at R1 and R3 (mol%) 100 50 0 0 90 Amount of thickener (% by weight) 24.5 26.0 15.0 11.0 25.5 Dynamic viscosity at 40 ° C base oil (cSt) 97.0 97.0 97.0 97.0 190.0 NLGI rating 275 (No.2) 290 (No.2) 287 (No.2) 270 (No.2) 273 (No.2) Leakage at high temperature and high speed (% by weight) 5.1 20.1 36.7 38.9 6.4 Durability at high temperature and high speed 1000 (pass) 650 470 419 1000 (pass) Durability and fracture resistance at high loads (n = 5) 200 270 330 500 700 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 250 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 180 200 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) Starting torque at -40 ℃ pass pass pass pass pass Rust resistance of bearing pass pass pass pass pass

Table 7

Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Thickener Diisocyanate TDI MDI 225.4- 225.0- 225.0- 176.2- 288.1- Lithium stearate                                              500-- Monoamine D-Toluidine CHA Octylamine  251.0-33.6  250.4-33.6  250.4-33.6  197.4-25.4  320.1-42.8 Base oil Alkyldiphenyl ether poly-alpha-olefin A poly-alpha-olefin B -554.0 836.0 856.0-534.0 --1,400.0 1,500.0-- 1,260.0-- 1,400-- Rust inhibitor Organo sulfonate (water insoluble) Zinc Sulfonate 30.0 Barium sulfonate 30.0 Alkenyl Succinic Anhydride 20.0 Ammonium Sulfonate 20.0 Barium sulfonate 20.0 Zinc Sulfonate 20.0 Night light (water soluble) - Sodium Night Light 30.0 Dispersion Sodium Night Light 20.0 Dispersion Organic Acid Amine Salt 20.0 Sodium Night Light 10.0 Sodium Night Light 10.0 Nonionic Surfactant (HLB Value) Sorbitan Trioleate (3.0) 33.0 - Sorbitan Trioleate (3.0) 20.0 Sorbitan Trioleate (3.0) 20.0 Polyoxy Ethylene Ester (11.8) 20.0 Sorbitan Trioleate (3.0) 20.0

Table 8

Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Aromatic Hydrocarbon Ratios at R1 and R3 (mol%) 90 90 90 90 90 - Amount of thickener (% by weight) 25.5 25.5 25.5 20.0 32.5 25.0 Dynamic viscosity at 40 ° C base oil (cSt) 94.0 75.0 45.0 97.0 97.0 97.0 NLGI rating 281 (No.2) 282 (No.2) 290 (No.2) 355 (No.0) 198 (No.4) 270 (No.2) Leakage at high temperature and high speed (% by weight) 6.7 6.8 7.0 43.0 4.5 67.0 Durability at high temperature and high speed 1000 (pass) 660 480 420 1000 (pass) 32 Durability and fracture resistance at high loads (n = 5) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 180 200 1000 (pass) 1000 (pass) 1000 (pass) 160 180 210 1000 (pass) 1000 (pass) 220 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 1000 (pass) 160 200 210 1000 (pass) 1000 (pass) Starting torque at -40 ℃ pass pass pass pass fail - Rust resistance of bearing fail fail fail fail fail -

The grease of the composition as described herein exhibits excellent performance under the harsh conditions of high temperature, high speed and high load in bearings applied to automotive electronic components such as Alternator, Electro-Magnetic Clutch, Idler-Pulley, etc. have.

Claims (4)

As a lubricating grease composition for bearings, the base oil is an alkyldiphenyl ether oil having a molecular weight of 4,000 to 6,000 and a kinematic viscosity in the range of 90 to 120 cSt at 40 ° C, and as a thickener, diurea The compound is contained in the range of 20 to 30% by weight, The molecular formula of the diurea compound is as follows,

In the above molecular formula, R2 is an aromatic hydrocarbon group having 6 to 20 carbon atoms, R1 and R3 are composed of an aromatic hydrocarbon group having 6 to 15 carbon atoms and an alkyl group having 8 to 20 carbon atoms, and the aromatics at R1 and R3 The proportion of hydrocarbons is 70 to 95 mole% bearing lubricating grease composition. The lubricating grease composition for bearings according to claim 1, wherein the diurea as the thickener is formed by the reaction of diisocyanate and monoamine. The method of claim 2, The diisocyanate is 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate (diphenyl methane-4,4'-diisocyanate) ) And naphthylene-1,5-diisocyanate (naphthylene 1,5-diisocyanate), The monoamine is benzylamine, toluidine and chloroaniline as aromatic amine, octylamine, nonylamine, decylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, Lubricating grease composition for bearings, characterized in that it is selected from the group consisting of hexadecylamine, heptadecylamine, octadecylamine, nonyldecylamine, eicosylamine. The method of claim 1, The lubricating grease composition for bearings contains 0.1 to 10% by weight of organosulfonate, nitrite and nonionic surfactant, respectively, The nonionic surfactant is at least one member selected from the group consisting of glycerin fatty acid esters, polyglycerol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene fatty acid esters and polyoxyethylene alkylphenyl ethers. .

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