JP2001107073A - Grease composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grease composition exhibiting a long life to seizure under high-temperature high-speed conditions. SOLUTION: This composition is one containing a base oil and a thickener, wherein the base oil contains an ester oil, the thickener contains a diurea compound represented by the general formula, and the content of the diurea compound is 3-30 wt.% based on the composition. General formula : R1-NHCHOH- R2-NHCHOH-R3, wherein R1 and R3, which may be the same or different from each other, are each 6-20C aliphatic hydrocarbon group or a 6-12C aromatic hydrocarbon group; the rate of the alicyclic aliphatic hydrocarbon groups is 90-100 wt.% based on the entire weight of R1 and R3 groups; and R2 is a 6-15C divalent aromatic hydrocarbon group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a grease composition, and more particularly to an alternator, an electromagnetic clutch for a car air conditioner, an idler pulley, an intermediate pulley, an electric fan motor,
Used in high-temperature and high-speed rotation of household electrical appliances such as fluid couplings, water pumps, distributors, starter one-way clutches and other automotive electrical components, high-speed and high-speed rotation of engine accessories, and other home appliances such as cleaner motors. The present invention relates to a grease composition suitable for being sealed in a rolling bearing or the like.

[0002]

2. Description of the Related Art Conventionally, grease compositions using a diurea compound as a thickener and an alkyldiphenyl ether oil as a base oil have been used as grease compositions for high-temperature and high-speed bearings.
It is used for automotive electrical parts, engine accessories and the like. In addition, some greases contain 10% by weight or more of ester oil in the base oil, and have excellent peeling resistance, low-temperature characteristics, and bearing acoustic performance, and have suppressed early seizure at high temperatures and high speeds. Did not have. In addition, there is a grease based on fluorine oil which has extremely excellent thermal oxidation stability, but there is a problem that it is expensive.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a grease composition having a long seizure life under high temperature and high speed conditions, particularly under high temperature conditions.

[0004]

According to the present invention, there is provided a grease composition comprising a base oil and a thickener, wherein the base oil comprises an ester oil, and the thickener comprises a diurea compound represented by the general formula (1). Wherein the content of the diurea compound is 3 to 30% by weight in the composition. General formula (1) R ¹ -NHCONH-R ² -NHCONH-R ^{3 In the} formula, R ¹ and R ³ may be the same or different, and may be an aliphatic hydrocarbon group having 6 to 20 carbon atoms, or carbon. 6 atoms
To 12 aromatic hydrocarbon groups, wherein the proportion of acyclic aliphatic hydrocarbon groups in the total amount of R ¹ and R ³ is 90 to 100
% By weight, and R ² represents a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms. In the general formula (1), preferably, R ¹ and R ³ may be the same or different, and are each an acyclic aliphatic hydrocarbon group having 6 to 20 carbon atoms. 6, 8, 10, 12, 14, 1
6 or 18 acyclic aliphatic hydrocarbon groups.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the general formula (1), R ¹ and R ³
An aliphatic hydrocarbon group having 6 to 20 carbon atoms represented by
Preferably an acyclic aliphatic hydrocarbon group, more specifically, a linear or branched alkyl or alkenyl group, for example, hexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl Group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dolacenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, Examples include a hexadecenyl group, a heptadecenyl group, an octadecenyl group, a nonadecenyl group, an eicosenyl group, and the like. Specific examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group, and a t-butylphenyl group.
Specific examples of the divalent aromatic hydrocarbon group having 6 to 15 carbon atoms represented by R ² include:

[0006]

Embedded image Is mentioned.

The ester oil used for the base oil of the grease composition of the present invention is not particularly limited. However, in consideration of heat resistance, pentaerythritol ester oil, dipentaerythritol ester oil, trimethylolpropane ester oil, neopentyl Glycol ester oil, complex ester oil, trimellitic acid ester oil, pyromellitic acid ester oil and the like can be mentioned. Examples of the aliphatic carboxylic acid component of the polyol ester oil include heptanoic acid, octanoic acid, isononanoic acid, and decanoic acid. Further, diester oils such as dioctyl sebacate, carbonic acid ester compounds, ether synthetic oils such as alkyl diphenyl ether, synthetic hydrocarbon oils such as polyalpha-olefin, and mineral oils such as paraffin mineral oils can also be used in combination. The base oil of the grease composition of the present invention preferably contains 10 to 100% by weight, more preferably 30 to 100% by weight, and most preferably 50 to 100% by weight of an ester oil. The base oil used in the present invention preferably has a kinematic viscosity at 100 ° C. of 3 to 30 mm ² / s.

The diurea compound represented by the general formula (1), which is used as a thickener in the present invention, is obtained by reacting a diisocyanate with a monoamine. Examples of the diisocyanate include phenylene diisocyanate, diphenyl diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate, and monoamines include hexylamine.
Octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, aniline,
p-Toluidine and the like.

The present invention relates to a thickener of the general formula (1)
In addition to the diurea compound represented by, organic bentonite, lithium soap (for example, lithium stearate and
Lithium 12-hydroxystearate), sodium soap, calcium soap, aluminum soap, or a complex soap of these may be used. The amount of the thickener used in the grease composition of the present invention is suitably 3 to 30% by weight, and 5 to 20% by weight based on the whole composition.
Is more preferred. In the grease composition of the present invention, the content of the diurea compound represented by the general formula (1) is 3 to
It is 30% by weight, preferably 5 to 20% by weight. The lubricant composition of the present invention, in addition to the above components, amine-based, phenol-based antioxidants, chlorine-based, sulfur-based, zinc dithiophosphate, extreme pressure agents such as organic molybdenum, molybdenum disulfide, melamine Solid lubricants such as cyanuric acid adduct (MCA), rust inhibitors such as petroleum sulfonate, dinonylnaphthalene sulfonate, sorbitan ester, metal deactivators such as benzotriazole and sodium nitrite, polymethacrylate, polyisobutylene, and polystyrene And a viscosity index improver such as polybutene.

[0010]

Next, the present invention will be described with reference to examples and comparative examples. Example 1, Comparative Examples 1 to 5 Diisocyanate and half of the base oil were mixed, and monoamine and half of the base oil were mixed in another container, and each was heated and reacted. After heating and stirring, the mixture was cooled to room temperature and kneaded with a three-stage roll mill to produce a grease composition. For each composition, the kinematic viscosity (mm ² / s) of the base oil (100 ° C.), the penetration consistency, and the bearing lubrication life were measured. Table 1 shows the results. Bearing lubrication life test (according to ASTM D3336) The bearing 6204 is filled with 1.8 g of sample grease, and a steel shield plate is crimped on both sides, the outer ring temperature of the bearing is maintained at 180 ° C, and the condition of Fa = Fr = 66.7N Below, the inner wheel is operated continuously at 10,000 rpm. When the grease sealed in the bearing deteriorates, the rotational torque of the bearing becomes excessive, and the time until an overcurrent (6 amps) occurs or the temperature of the bearing rises by 15 ° C. is defined as the grease life.

[0011]

[Table 1]

Ester oil A: (pentaerythritol ester oil: 5.
4mm ² / s (100 ° C)) Ester oil B: (Dipentaerythritol ester oil:
20 mm ² / s (100 ° C)) Ether oil A: alkyl diphenyl ether oil (13 mm ² / s
s (100 ° C.)) The above results show that the grease of the present invention has a better bearing lubrication life than the grease using other diurea compound as a thickener.

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Claims (3)

[Claims] 1. A grease composition containing a base oil and a thickener, wherein the base oil contains an ester oil, the thickener contains a diurea compound represented by the general formula (1), and contains the diurea compound. A grease composition characterized in that the amount is 3 to 30% by weight in the composition. General formula (1) R ¹ -NHCONH-R ² -NHCONH-R ^{3 In the} formula, R ¹ and R ³ may be the same or different, and may be an aliphatic hydrocarbon group having 6 to 20 carbon atoms, or carbon. 6 atoms
To 12 aromatic hydrocarbon groups, wherein the proportion of acyclic aliphatic hydrocarbon groups in the total amount of R ¹ and R ³ is 90 to 100
% By weight, and R ² represents a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms. 2. The grease according to claim 1, wherein, in the general formula (1), R ¹ and R ³ are the same or different and are acyclic aliphatic hydrocarbon groups having 6 to 20 carbon atoms. Composition. 3. In the general formula (1), R ¹ and R ³ may be the same or different and each have 6, 8, 10, 1 or more carbon atoms.
The grease composition according to claim 1, wherein the grease composition is 2, 14, 16 or 18 acyclic aliphatic hydrocarbon groups.