JP2002053884A - Grease composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grease composition excellent in pressure-feedability, and in shear stability and anticorrosive properties when the composition contains water. SOLUTION: This grease composition contains (a) a base oil, (b) a thickener comprising a diurea-based compound expressed by the formula: R1NH-CO-NH-C6 H4-CH2-C6H4-NH-CO-NHR2 (R1 and R2 may be the same to or different from each other, and are each a 6-30C alkyl, a 6-7C aryl or cyclohexyl), (c) at least one kind of a metal salt compound selected from a group comprising a basic metal sulfonate, a basic metal salicylate, and a basic metal phenate, and (d) an alkenyl succinic acid anhydride.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a grease composition, and more particularly to a grease composition suitable for bearings in steelmaking equipment, particularly for continuous casting equipment. The present invention
The present invention relates to a grease composition having excellent shear stability when containing water and excellent rust prevention.

[0002]

2. Description of the Related Art In the grease lubrication of machines, there are quite a few lubricating points that are susceptible to accidents such as continuous casting equipment bearings and rolling mill bearings in steel mills where water is applied to the grease and moisture is mixed into the grease, causing the grease to soften and run off. is there. The shear stability of grease depends on the type and composition of the thickener, but largely depends on the amount of the thickener. Generally, grease with excellent shear stability has a large amount of thickener,
Because of its poor pumpability, it is not suitable for centralized lubrication equipment such as iron making equipment.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a grease composition which is excellent in pumpability and excellent in shear stability and rust prevention when containing water.

[0004]

Means for Solving the Problems The present invention is a grease composition containing the following components. (a) base oil, (b) diurea thickener represented by the following formula (1), (1) R ¹ NH-CO-NH-C ₆ H ₄ -CH ₂ -C ₆ H ₄ -NH- CO-NHR ² (wherein, R ¹ and R ² are the same or different, and have 6 carbon atoms.
(C) an aryl group having 6 or 7 carbon atoms or a cyclohexyl group) (c) at least one metal selected from the group consisting of basic metal sulfonates, basic metal salicylates and basic metal phenates Salt compounds, and (d) alkenyl succinic anhydride.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The base oil of component (a) used in the present invention includes mineral oil, ester-based synthetic oil, ether-based synthetic oil, and synthetic hydrocarbon oil. These alone
Two or more kinds may be used as a mixture.

The diurea thickener of the component (b) used in the present invention is represented by the following formula (1). (1) R ¹ NH-CO-NH-C ₆ H ₄ -CH ₂ -C ₆ H ₄ -NH-CO-NHR ^{2 In the} formula, R ¹ and R ² are the same or different, and have 6 to carbon atoms.
An alkyl group of 30; an aryl group having 6 or 7 carbon atoms; or a cyclohexyl group. Such diurea-based thickeners include alkyl monoamines such as octylamine, stearylamine, dodecylamine and hexadecylamine; aryl monoamines such as aniline and p-toluidine; monoamines such as cyclohexylamine and diphenylmethane-4,4'-. Obtained by reaction with diisocyanate. Particularly preferred thickeners are the diurea compounds of the formula (1) in which R ¹ and R ² are the same or different and are an alkyl or cyclohexyl group having 6 to 30 carbon atoms. The content of the diurea-based thickener of the component (b) in the grease composition is preferably 3 to 20% by mass, more preferably 4 to 15% by mass.

The basic metal sulfonate, basic metal phenate and basic metal salicylate of the component (c) used in the present invention are all known as metal-based detergents / dispersants and rust preventives used in lubricating oils such as engine oils. Have been. The basic metal sulfonate is a metal salt such as an alkyl aromatic sulfonic acid such as dinonylnaphthalenesulfonic acid or alkylbenzenesulfonic acid. The basic metal phenate is a metal salt of a long-chain alkylphenol derivative (sulfurized alkylphenol). Basic metal salicylates are compounds similar to metal phenates and are metal salts of alkyl salicylic acid derivatives. Examples of the metal salt include an alkaline earth metal salt such as a calcium salt, a barium salt, and a magnesium salt. All contain fine carbonates (for example, CaCO ₃ , BaCO ₃ , MgCO ₃ ), and it is preferable that the content of the carbonate is large, that is, the base number is high.
In the case of alkaline earth metal salts, calcium salts are the most effective as compared with barium salts, magnesium salts and the like. The base number is preferably 40 mg-KOH / g to 500 mg-KOH / g, more preferably 300 mg-KOH / g or more, and still more preferably 400 mg-KOH / g.
That is all. A preferred metal salt in the present invention is a basic metal sulfonate, and particularly a basic calcium sulfonate. The content of the basic metal salt of the component (c) in the grease composition is preferably 0.5 to 15% by mass.

The alkenyl succinic anhydride of the component (d) used in the present invention is known as a grease rust preventive. The alkenyl group of the alkenyl succinic acid preferably has 6 to 30 carbon atoms. The content of the alkenyl succinic anhydride in the grease composition is preferably 0.1 to 3% by mass.

In the present invention, the thickener is a diurea compound of the formula (1) in which R ¹ and R ² are the same or different and are an alkyl group or a cyclohexyl group having 6 to 30 carbon atoms, and a basic metal salt Is a basic metal sulfonate, the content of which is 0.5 to 15% by mass, and the content of alkenyl succinic anhydride which is 0.1 to 3% by mass is particularly preferred. When the content of the component (b) is less than 3% by mass, the content of the component (c) is less than 0.5% by mass, and the content of the component (d) is less than 0.1% by mass, the desired effect is insufficiently exhibited. On the other hand, when the content of the component (b) is more than 20% by mass, the pumpability is reduced, the content of the component (c) is more than 15% by mass, and the content of the component (d) is 3% by mass. Even if it is increased, the effect is not increased and the economy is lacking.

The grease composition of the present invention contains other additives commonly used in grease compositions, such as antioxidants, metal deactivators, surfactants, extreme pressure agents, friction modifiers and the like. May be contained.

[0011]

Next, the present invention will be described with reference to examples and comparative examples. (1) Grease containers of Examples and Comparative Examples 1316 g of base oil and 138 g of diphenylmethane-4,4'-diisocyanate were placed in a container, and the mixture was heated to 70 to 80 ° C.
Put 1400 g of base oil and 146 g of octylamine in a separate container,
After heating to 8080 ° C., it was added to the previous container. The mixture was heated to 160 ° C. while being sufficiently stirred, and allowed to cool to obtain a base urea grease. A base oil is added to the base urea grease as needed.
To obtain grease A. Additives were added to grease A in the formulations shown in Tables 1 to 3, and a base oil was added as appropriate. The resulting mixture was adjusted to a consistency of 350 using a three-roll mill. In the above Examples and Comparative Examples, mineral oils having the following characteristics were used as base oils for grease.

(2) Test method for water-containing shear stability test and rust prevention test 1. Water-containing shear stability test Using an apparatus used for the roll stability test method of ASTM D1831, 10 g of distilled water was added to grease. % Was used as a sample and operated at a temperature of 80 ° C. for 24 hours, and the hydrous shear stability was evaluated based on the difference in grease consistency before and after the test. This value is 60 or less, preferably 50 or less, more preferably 45 or less.
It is desirable that: 2. Rust prevention test Using a device that is used for the bearing rust prevention test method of ASTM D 1743, apply grease containing 30% distilled water to a sample, apply a torque of 1000 kgf to the bearing, and apply a temperature of 80 ° C. After standing for 144 hours, the rusting state of the bearing was confirmed. # 1: No rust on outer race surface # 2: Less than 3 rust on outer race surface # 3: More than 4 rust on outer race surface

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

1) Basic Ca sulfonate (trade name: BRYTON
C-400C WITCO CHEMICAL) (base number 400mg-KOH / g, purity 60% by mass, CaCO ₃ concentration in basic Ca sulfonate is about 35% by mass) 2) Alkenyl succinic anhydride (trade name MSP Mitsubishi Nisseki) Petroleum) 3) Basic Ca phenate (trade name OLOA 218A manufactured by Olonite Japan) (base number 147 mg-KOH / g, purity 60% by mass) 4) Basic Ca salicylate (trade name OSCA-438B manufactured by Osuka Chemical) (Base value: 320 mg-KOH / g, purity: 65% by mass) 5) Fatty acid amine salt (trade name: Kyresgard C, manufactured by Nippon Kagaku Sangyo)

Examples 1 to 14 containing components (a) to (d) of the present invention
Is excellent in pumpability, and is excellent in shear stability when containing water and rust prevention. In contrast, the components
The grease compositions of Comparative Examples 1 to 3, 5 and 6, which do not contain at least one of the metal salt of (c) and the alkenyl succinic anhydride of component (d), are inferior in shear stability and rust resistance when containing water. ,
Not practical. Comparative Example 4 using a fatty acid amine salt instead of alkenyl succinic anhydride as a rust inhibitor
The grease composition described above is also not practical because of poor shear stability and rust prevention when containing water.

[0018]

The grease composition of the present invention contains at least one metal salt compound selected from the group consisting of basic metal sulfonates, basic metal salicylates and basic metal phenates, and alkenyl succinic anhydride. Therefore, it is excellent in shear stability and rust prevention when containing water.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10M 159/24 C10M 159/24 // C10N 10:04 C10N 10:04 30:00 30:00 C30: 12 30:12 40:02 40:02 50:10 50:10 (72) Inventor Hiroshi Kimura 1-4-1 Tsujido Shindai, Fujisawa-shi, Kanagawa F-term in Kyodo Yushi Co., Ltd. 4H104 BB18C BE13B DA02A DB06C DB07C EB02 FA02 LA06 LA13 PA01 QA18

Claims (6)

[Claims] 1. A grease composition comprising the following components: (a) base oil, (b) diurea thickener represented by the following formula (1), (1) R ¹ NH-CO-NH-C ₆ H ₄ -CH ₂ -C ₆ H ₄ -NH- CO-NHR ² (wherein, R ¹ and R ² are the same or different, and have 6 carbon atoms.
(C) an aryl group having 6 or 7 carbon atoms or a cyclohexyl group) (c) at least one metal selected from the group consisting of basic metal sulfonates, basic metal salicylates and basic metal phenates Salt compounds, and (d) alkenyl succinic anhydride. 2. The grease composition according to claim ^1, wherein R ¹ and R ² are the same or different and are an alkyl group having 6 to 30 carbon atoms or a cyclohexyl group. 3. The content of the metal salt compound is 0.5 to 15% by mass.
3. The grease composition according to claim 1, which is: 4. The grease composition according to claim 1, wherein the metal salt compound is a basic metal sulfonate. 5. An alkenyl succinic anhydride having a content of anhydride
The grease composition according to any one of claims 1 to 4, which is 0.1 to 3% by mass. 6. R ¹ and R ² are the same or different and each is an alkyl group or cyclohexyl group having 6 to 30 carbon atoms, the basic metal salt is a basic metal sulfonate, and its content is 0.5 to 15 mass%. The grease composition according to any one of claims 1 to 5, wherein the content of the alkenyl succinic anhydride is 0.1 to 3% by mass.