JPH06100878A - Grease composition - Google Patents

Abstract

PURPOSE:To obtain a composition excellent in frictional and wear characteristics by incorporating a specified molybdenum compound and a specified acidic phosphoric ester (amine salt) each in a specified amount into a base grease. CONSTITUTION:This composition is obtained by mixing 100 pts.wt. base grease (e.g. urea grease) with 0.1-10 pts.wt. molybdenum compound of formula I (wherein R1 to R4 are each a 1-20C hydrocarbon group; and X is S or O except for the case where all of them are O at the same time) and 0.1-10 pts.wt. acidic phosphoric ester (amine salt) consisting of 20-100mol% acidic phosphoric ester of formula II (wherein R5 and R6 are each H or a 4-20C hydrocarbon group except for the case where all of them are H at the same time) and 80-0mol% amino compound of formula III (wherein R7 and R8 are each H or a 4-30C hydrocarbon group except for the case where all of them are H at the same time).

Description

Detailed Description of the Invention

[0001]

The present invention relates to a grease composition,
More specifically, it relates to a grease composition having excellent friction and wear characteristics, which is used for constant velocity joints, universal joints, constant velocity gears, transmission gears and the like of automobiles.

[0002]

2. Description of the Related Art Conventionally, grease containing a sulfur-phosphorus compound or molybdenum disulfide has been used in places where the surface pressure is high, wear is likely to occur and abnormal vibration is likely to occur. However, from the viewpoints of comfort and noise in automobiles, the demand for grease is becoming more and more severe. For example, in constant velocity joints of automobiles, when the above-mentioned grease is used, abnormal vibration is caused due to lack of extreme pressure, acceleration of wear and shortening of the life of lubricating parts are a problem. .

Under such circumstances, molybdenum dithiocarbamate (MoDTC) has been attracting attention for grease applications. However, MoDTC alone has insufficient lubrication performance, and in order to improve the lubrication performance, the following patents are given as conventional techniques. For example, JP-A-2-20597 and JP-A-62-207397 both disclose MoDTC.
And the combined use of phosphoric acid ester is described.

[0004]

However, the above-mentioned grease composition has not been able to cope with the lubrication system which becomes severe year after year, and there is still room for improvement.

Accordingly, it is an object of the present invention to provide a grease composition having excellent friction and wear characteristics.

[0006]

Means for Solving the Problems The present inventor has conducted extensive studies in order to achieve the above-mentioned object, and as a result, surprising lubricity was developed by combining a certain acidic phosphoric acid ester (amine salt) with MoDTC. The present invention has been completed and the present invention has been completed.

That is, the grease composition according to the present invention contains 0.1 to 10 parts by weight of the molybdenum compound represented by (a) the general formula (1) based on 100 parts by weight of the base grease;

[Chemical 4] (Wherein R ₁ , R ₂ , R ₃ and R ₄ represent the same or different saturated or unsaturated hydrocarbon groups having 1 to 20 carbon atoms, X is S or O, but all are O. None), and (b) an acidic phosphoric acid composed of 20 to 100 mol% of an acidic phosphoric ester represented by the general formula (2) and 80 to 0 mol% of an amino compound represented by the general formula (3). 0.1 to 10 parts by weight of ester (amine salt);

[Chemical 5] (In the formula, R ₅ and R ₆ are hydrogen or a saturated or unsaturated hydrocarbon group having 4 to 20 carbon atoms which is the same or different, but not all hydrogen)

[Chemical 6] (In the formula, R ₇ and R ₈ are hydrogen or a saturated or unsaturated hydrocarbon group having 4 to 30 carbon atoms which is the same or different, but not all hydrogen) It is characterized by

In the molybdenum compound represented by the general formula (1) of (a) used in the present invention, the hydrocarbon group represented by R ₁ , R ₂ , R ₃ and R ₄ is a saturated or unsaturated bond. May be a straight chain, branched chain,
Alternatively, they may be cyclic, or a combination thereof, and they may be the same or different and have 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms. When the number of carbon atoms exceeds 20, the molybdenum content becomes low and the addition efficiency deteriorates, which is not preferable.

Such hydrocarbon groups include aliphatic, aromatic and aromatic-aliphatic groups. In particular,
Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, 2-methylbutyl group, hexyl group, octyl group, 2-ethylhexyl group,
Nonyl group, decyl group, lauryl group, tridecyl group, isotridecyl group, myristyl group, palmityl group, stearyl group and other alkyl groups, propenyl group, butenyl group, isobutenyl group, pentenyl group, 2-ethylhexenyl group,
Octenyl group, palmitooleyl group, alkenyl group such as oleyl group, cyclopentyl group, cyclohexyl group, methylcyclopentyl group, cycloalkyl group such as ethylcyclopentyl group, phenyl group, naphthyl group, alkyl-substituted phenyl group (for example, toluyl group, nonylphenyl group etc)
And aryl groups such as benzyl, and aralkyl groups such as phenethyl. Preferably methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, lauryl group, tridecyl group, isotridecyl group. The base is good. In the compound represented by the general formula (1), all Xs are not O at the same time.

The molybdenum compound (a) is, for example, Japanese Patent Publication No. 53-31646, Japanese Patent Publication No. 55-40593, Japanese Patent Publication No. 56-12638, Japanese Patent Publication No. 57-24797, and Japanese Patent Publication No. 58-58.
It can be produced by the method described in JP-A-50233 and JP-A-62-81396.

In the acidic phosphoric acid ester represented by the general formula (2) which constitutes the acidic phosphoric acid ester (amine salt) of (b) used in the present invention, R ₅ and R ₆ are hydrogen and / or a hydrocarbon group. And the hydrocarbon group may contain a saturated or unsaturated bond, may be linear, branched, or cyclic, or any combination thereof, and may be the same or They may be different, and preferably have 4 to 20 carbon atoms, preferably 6 to 16 carbon atoms. Further, neither R ₅ nor R ₆ is hydrogen. If the number of carbon atoms is less than 4, sufficient lubricity cannot be obtained,
If it exceeds 20, the melting point becomes high and the workability becomes poor, which is not preferable.

Such hydrocarbon groups include aliphatic, aromatic and aromatic-aliphatic groups. In particular,
Butyl group, isobutyl group, pentyl group, 2-methylbutyl group, hexyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl, lauryl group, tridecyl group, isotridecyl group, mistyryl group, palmityl group, stearyl group. Alkyl group such as, propenyl group, butenyl group, isobutenyl group, pentenyl group, 2-ethylhexenyl group, octenyl group, alkenyl group such as palmitooleyl group, oleyl group, cyclopentyl group, cyclohexyl group, methylcyclopentyl group, ethylcyclopentyl group, etc. And cycloalkyl groups, phenyl groups, naphthyl groups, aryl groups such as alkyl-substituted phenyl groups (eg, toluyl group, nonylphenyl group, etc.), aralkyl groups such as benzyl group, phenethyl group, etc. From the viewpoint of lubricity, an alkyl group is preferable, and a hexyl group is particularly preferable,
2-ethylhexyl group, octyl group, decyl group, lauryl group, tridecyl group, myristyl group and the like are preferable.

Next, in the amino compound represented by the general formula (3) which constitutes the acidic phosphoric acid ester (amine salt) of (b) used in the present invention, R ₇ and R ₈ are hydrogen and / or hydrocarbon. The hydrocarbon group may be a group containing a saturated or unsaturated bond, and may be linear, branched, or
Alternatively, it may be cyclic, or a combination thereof, and may be the same or different, and may have 4 to 30 carbon atoms, preferably 8 to 20 carbon atoms. Moreover, neither R ₇ nor R ₈ is hydrogen. When the number of carbon atoms is less than 4, the boiling point is low when it is small,
If it exceeds, the melting point becomes high and the workability becomes poor, which is not preferable.

Such hydrocarbon groups include aliphatic, aromatic and aromatic-aliphatic groups. In particular,
Butyl, isobutyl, pentyl, 2-methylbutyl, hexyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, lauryl, tridecyl, isotridecyl, myristyl, palmityl, stearyl An alkyl group such as a group, a propenyl group,
Butenyl group, isobutenyl group, pentenyl group, 2-ethylhexenyl group, octenyl group, palmitooleyl group,
Alkyl group such as oleyl group, cyclopentyl group, cyclohexyl group, methylcyclopentyl group, cycloalkyl group such as ethylcyclopentyl group, phenyl group, naphthyl group, aryl group such as alkyl-substituted phenyl group (for example, toluyl group, nonylphenyl group, etc.) And aralkyl groups such as benzyl group and phenethyl group. From the viewpoint of lubricity, an alkyl group and an alkenyl group are preferable, and a 2-ethylhexyl group, an octyl group, a decyl group, a lauryl group, a tridecyl group, a myristyl group, a palmitooleyl group and an oleyl group are particularly preferable.

The acidic phosphoric acid ester (amine salt) of (b) used in the present invention is 20 to 100 mol% of the acidic phosphoric acid ester represented by the general formula (2), and is represented by the general formula (3). The amino compound represented by the general formula (2) may be contained in an amount of 80 to 0 mol%, preferably 30 to 70 mol% of the acidic phosphoric acid ester represented by the general formula (2), and the amino compound represented by the general formula (3). A composition ratio of 70 to 30 mol% is preferable. The effect does not appear outside the above range.

When (b) is an acidic phosphoric acid ester amine salt, the general formula (2) and the general formula (3) constituting the same are used.
Even if the compounds represented by the formulas (1) and (2) are separately added to the base grease, the compounds represented by the general formulas (2) and (3) are mixed in advance to obtain the acidic phosphate ester amine salt of (b), It may be added to grease.

The grease composition of the present invention comprises a base grease 10
0 parts by weight of the molybdenum compound (a) above 0.1
0.1 to 10 parts by weight of (b) the acidic phosphoric acid ester (amine salt) compound [containing an excess of each of the compounds represented by the general formulas (2) and (3) constituting the amine salt]. Parts by weight
It is sufficient to contain 10 parts by weight of each, and if the amount is less than the above amount, sufficient lubricity cannot be obtained, and even if the amount exceeds the above range, the lubricity is not improved so much, and conversely the consistency is lowered, which is not preferable. In addition, the molybdenum compound (a) and
The amount of the acidic phosphoric acid ester (amine salt) compound added in (b) may be within the above range, but a preferable range is 0.5 part by weight of the molybdenum compound in (a) to 100 parts by weight of the base grease. 5 parts by weight, (b) acidic phosphoric acid ester (amine salt)
The amount of the compound [containing an excess of each of the compounds represented by the general formulas (2) and (3) constituting the amine salt] is 0.5 to 5 parts by weight.

Examples of the base grease that can be used in the grease composition of the present invention include metal soap grease using mineral oil and / or synthetic oil, metal soap composite grease, urea grease, grease using organically treated clay such as benton. Can be mentioned. From the viewpoint of heat resistance, urea grease is preferable.

The grease composition of the present invention may contain zinc dithiophosphate, if desired, within the scope of the object of the present invention.
An extreme pressure additive such as a sulfur-phosphorus compound and molybdenum dithiophosphate and a solid lubricant such as molybdenum disulfide and graphite can be used together in a usual amount.

Further, the grease composition of the present invention is, within the scope of the object of the present invention, optionally a component known as a grease additive, such as NN-trimethylene diamine dioleate, sorbitan monooleate and the like, for preventing rust. Agents, dioctylphenylamine, antioxidants such as 2,6-tert-paracresol, and the like can be appropriately added in usual amounts.

[0021]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. A grease composition was prepared by using the following samples 1 to 11 and a base grease at a compounding ratio shown in Table 1, and various tests were conducted.

Sample 1: Compound represented by the following formula

[Chemical 7] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are 2-ethylhexyl groups)

Sample 2: Compound represented by the following formula

[Chemical 8] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are isobutyl groups)

Sample 3: The following equation

[Chemical 9] (In the formula, R ₁ and R ₂ are 2-ethylhexyl groups, and the molecular weight is 322), and

[Chemical 10] (In the formula, R ₁ is a 2-ethylhexyl group, the molecular weight is 210)
A mixture of compounds represented by (molar ratio 1: 1, average molecular weight 266)

Sample 4: Compound represented by the following formula

[Chemical 11] (In the formula, R ₁ and R ₂ are isodecyl groups, and the molecular weight is 378)

Sample 5: a compound represented by the following formula R ₁ NH ₂ (wherein R ₁ is an oleyl group, the molecular weight is 267)

Sample 6: Compound represented by the following formula

[Chemical 12] (In the formula, R ₁ and R ₂ are 2-ethylhexyl groups, and the molecular weight is 241)

Sample 7: 50 mol% of sample 4 and 50 mol%
Sample 6 mixture

Sample 8: 50 mol% of sample 3 and 50 mol%
Sample 5 mixture

Sample 9: 75 mol% of sample 3 and 25 mol%
Sample 5 mixture

Sample 10: Mixture of 22 mol% of Sample 3 and 78 mol% of Sample 5

Sample 11: tricresyl phosphate

Base grease: Urea grease (10
(Adjusted to 287 cSt at 25 ° C. using polyurea as a thickener using refined mineral oil having a kinematic viscosity of 15 cSt at 0 ° C.)

[0034]

[Table 1]

An abrasion resistance test was conducted on the lubricating oil composition obtained above by the following method. The results are shown in Table 2. <Abrasion resistance test> As the abrasion resistance test, a high-speed four-ball test was performed under the following conditions. Conditions Rotation speed 1200 rpm Load 40 kg Temperature 40 ° C. Test time 60 minutes

[0036]

[Table 2]

[0037]

The effect of the present invention is to provide a grease composition having excellent friction and wear characteristics. That is, the grease composition of the present invention exhibits excellent friction and wear characteristics in a lubrication system and can be used in greases for various purposes including constant velocity joints of automobiles.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number in the agency FI Technical indication location C10N 30:06 40:04 50:10 (72) Inventor Koyoshi Namiha 7-chome Higashiohisa, Arakawa-ku, Tokyo No. 2-35 Asahi Denka Kogyo Co., Ltd. (72) Inventor ▲ Tatsumi ▼ Yukio Higashio 7-35, Arakawa-ku, Tokyo Inside Asahi Denka Kogyo Co., Ltd. (72) Inventor Kazutoshi Morita Hisashi Higashi-o Arakawa-ku, Tokyo 7th 2-35 Asahi Denka Co., Ltd.

Claims (1)

[Claims] 1. To 100 parts by weight of the base grease, (a)
The molybdenum compound represented by the general formula (1) is used in an amount of 0.1 to 10
Parts by weight; (Wherein R ₁ , R ₂ , R ₃ and R ₄ represent the same or different saturated or unsaturated hydrocarbon groups having 1 to 20 carbon atoms, X is S or O, but all are O. None), and (b) an acidic phosphoric acid composed of 20 to 100 mol% of an acidic phosphoric acid ester represented by the general formula (2) and 80 to 0 mol% of an amino compound represented by the general formula (3). 0.1 to 10 parts by weight of ester (amine salt); (In the formula, R ₅ and R ₆ are hydrogen or the same or different saturated or unsaturated hydrocarbon groups having 4 to 20 carbon atoms, but not all hydrogen) (In the formula, R ₇ and R ₈ are hydrogen or a saturated or unsaturated hydrocarbon group having 4 to 30 carbon atoms which is the same or different, but not all hydrogen) A grease composition characterized by the above.