JPH08183976A - Grease composition - Google Patents

Abstract

PURPOSE: To obtain the new composition, comprising a base oil consisting essentially of a new polyphenyl thioether compound and a thickener, capable of attaining improved heat and oxidation resistances and long service life at high temperatures and suitable for bearings, etc., in rotating parts and driving parts of automobiles, etc. CONSTITUTION: This composition comprises (A) a compound of the formula [R is a 1-24C hydrocarbon, (n) is 1-4] (preferably monopentyl-m-triphenyl thioether, etc.) as a main component of a base oil and (B) a thickener (preferably urea). The component (B) is preferably blended in an amount of 2-35wt.% based on the total weight of the composition. A mineral oil, a poly α-olefin oil, etc., can be used as the base oil in addition to the component (A). An antioxidant, a rust preventing oil, an extreme-pressure additive, etc., as necessary, can be added to the composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel grease composition, and more particularly to a grease composition suitable for bearings of rotating parts and driving parts of ironmaking equipment, automobiles and industrial equipment. According to the present invention, a grease composition having excellent heat resistance and high temperature and long life is provided.

[0002]

2. Description of the Related Art Grease has hitherto been manufactured mainly with a base oil, a thickener and an additive, and extensive research and development have been carried out on the base oil and the thickener, especially the thickener, and the thickener Greases are roughly classified into soap-based greases, complex soap-based greases, and non-soap-based greases depending on the type of agent. With recent advances in mechanical technology, automobile wheel bearings, constant velocity ball joints (CV
In J) etc., high-speed rotation is performed, heat generated from the brake and differential parts is also transferred, and the temperature of each lubrication part rises, and the electrical components inside the bonnet are in a high temperature state as the performance and weight of automobiles increase. It is scented. Furthermore, the grease itself is being maintained without maintenance after replacement. Also, grease is often used in rolling and sliding bearings in steel equipment, but there are many problems in high-temperature locations, and maintenance-free measures are inevitable in order to automate the equipment and save labor.

As described above, the mechanical parts of the apparatus in which the grease is used are remarkably heated to a high temperature, and at present, high temperature heat resistance and long service life of the grease are strictly required.

On the other hand, conventionally, it has been proposed to use a urea compound such as allyldiurea as a thickener, which belongs to the above-mentioned non-soap group grease as a grease having improved heat resistance. For example, Japanese Patent Laid-Open No. 1-25
No. 9097 discloses a grease composition in which a base oil containing an alkyldiphenyl ether oil as an essential component is mixed with a diurea compound having a specified ratio of aromatic hydrocarbon groups as a thickener.

However, the alkyl diphenyl ether oil, which is the essential component proposed here, has less change in consistency at high temperatures and is excellent in oxidation resistance as compared with ester oils and poly α-olefin oils. As can be understood from the present proposal, grease having excellent heat resistance can be obtained only with the base oil unless the chemical structure of the thickener is limited. In particular, in order to cope with the high temperature of lubrication parts and maintenance-free grease lubrication in steelmaking facilities, automobiles, etc. in recent years, not only improvement of thickener but also improvement of high temperature and long life of base oil itself is indispensable. Has become.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a steelmaking facility,
Lubrication of automobiles and parts Under excellent circumstances, it is possible to achieve excellent heat resistance, oxidation resistance, and long service life at high temperatures under the circumstances that it is required to cope with high temperatures in various parts and maintenance-free lubricants. An object is to provide a base oil component of a grease composition.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems based on the above-mentioned technical background, the present inventors have carried out basic research from the viewpoint of the chemical structure of grease base oil, and as a result,
It has been found that the novel polyphenyl thioether compound can achieve the heat resistance, oxidation resistance, and high temperature longevity required for the present grease composition. The present invention has been completed based on this finding.

Thus, according to the present invention, the general formula [1]

[0009]

Embedded image (In the formula, R is the same or different and has 1 to 1 carbon atoms.
Is a hydrocarbon group having 24, and n is an integer of 1 to 4. A grease composition comprising a base oil containing a compound represented by the formula (4) as a main component and a thickener is provided.

Further, the following grease compositions are provided as preferred embodiments of the present invention.

That is, the grease composition provided is the grease composition according to the item (1), wherein the compound represented by the general formula [1] is an alkyl group-substituted meta-phenyl thioether. 3. The grease composition according to item 1 or 2 wherein the compound represented is monoalkyl meta-phenyl thioether, and the compound represented by the general formula [1] is dialkyl meta-phenyl thioether. The grease composition of

The present invention will be described in detail below.

In the present invention, R in the formula [1] is used.
Are the same or different and each is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms. As the hydrocarbon group, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkenyl group having 2 to 24 carbon atoms,
Examples thereof include a cycloalkyl group having 6 to 24 carbon atoms, an aryl group, an arylalkyl group, and an alkylaryl group.
Among these hydrocarbon groups, an alkyl group is preferable for the present invention, and a particularly preferable alkyl group is one having 10 to 18 carbon atoms. In the present invention, the carbon number is 1
A compound having an alkyl group of -24 is used, but a compound having an alkyl group having 5 or more carbon atoms is particularly excellent in lubricity. On the other hand, a carbon number of 24 or less is particularly preferable in terms of oxidation resistance.

Further, a hydrocarbon group containing an amino group, a sulfide group or the like in the molecule can also be used.

Preferred alkyl groups are pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, lauryl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, ocdecyl group, Structural isomers such as isoforms of nonadecyl and eicosyl groups or their alkyl groups are also included in the present invention.

N is an integer of 1 to 4, preferably 1 to
It is an integer of 3.

Specific examples of preferred compounds in the present invention are as follows.

Monopentyl meta-triphenyl thioether dipentyl meta-triphenyl thioether monohexyl meta-triphenyl thioether dihexyl meta-triphenyl thioether monoheptyl meta-triphenyl thioether diheptyl meta-triphenyl thioether monooctyl meta-triphenyl thioether dioctyl meta -Triphenylthioether monononylmeta-triphenylthioether dinonylmeta-triphenylthioether monodecylmeta-triphenylthioether didecylmeta-triphenylthioether monoundecylmeta-triphenylthioether diundecylmeta-triphenylthioether monododecylmeta-triphenylthioether didodecylmeta-triphenylthio Ether monotridecyl meta-triphenyl thioether ditridecyl meta-triphenyl thioether monotetradecyl meta-triphenyl thioether ditetradecyl meta-triphenyl thioether monoheptadecyl meta-triphenyl thioether diheptadecyl meta-triphenyl thioether monohexadecyl meta -Triphenyl thioether dihexadecyl meta-triphenyl thioether monooctadecyl meta-triphenyl thioether dioctadecyl meta-triphenyl thioether monononadecyl meta-triphenyl thioether dinonadecyl meta-triphenyl thioether monoeicosyl meta-triphenyl thioether and dieicosyl meta -Triphenyl thioether base oils according to the invention are generally As a main component a compound represented by [1], which in other types of base oils, such as mineral oil, diester oil, alkyl diphenyl ether may be mixed with hindered ester or poly α- olefin oil.

Next, the thickener will be described. Any thickening agent can be used in the present invention. That is, a soap thickener such as calcium soap, sodium soap, lithium soap, calcium complex soap,
Complex soaps such as aluminum complex soap and lithium complex soap, thickeners and non-soap thickeners such as beretone, silica aerosol, terephthalamate, urea, polytetrafluoroethylene, boron nitride and the like can be mentioned. The grease composition of the present invention can be produced by using any thickener, but in order to secure heat resistance, improve oxidative stability, and particularly to achieve high temperature and long life, a non-soap thickening agent is used. It is preferable to use an agent. Among non-soap thickeners, terephthalamate, urea, polytetrafluoroethylene (PTF
E) and boron nitride are preferable, and urea is particularly preferable. The chemical structure of these thickeners is not particularly limited and may be one that is available as a commercial product, but when mentioning the method for producing urea, the reaction between diisocyanate and monoamine is usually used. Examples of diisocyanates include 2,4-tolylene diisocyanate and 2,6-
Tolylene diisocyanate, diphenylmethane-4,4
′ -Diisocyanate and the like, and examples of monoamines include aniline, benzylamine, and toluidine.

These non-soap thickeners are fine particles,
It is in the form of short fibers or a string, and the compounding amount of the thickener is 2% by weight to 40% based on the total weight of the grease composition based on the base oil.
It is in the range of% by weight. A preferred blending amount is 2% by weight to 3
It is in the range of 5% by weight. When the blending amount is less than 2% by weight, softening and outflow of grease occur in the bearing, while when the blending amount exceeds 40% by weight, the softening of grease occurs.

If desired, additives such as antioxidants, rust preventives, extreme pressure agents, oiliness agents and the like are added to the grease composition of the present invention.

[0022]

The meta-triphenyl thioether used in the present invention has a constant viscosity even at high temperatures, has a small amount of evaporation, and is excellent in oxidation resistance, and exhibits good results when used as the main component of grease base oil. To do. This base oil is not limited to a thickener, and any thickener is arbitrarily selected and mixed depending on the application.

The grease composition of the present invention has the general formula [1]
It was possible to achieve heat resistance, oxidation resistance, and high temperature and long life by using a base oil containing a novel polyphenylthioether compound represented by

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples.

In each of the examples and comparative examples, a grease was manufactured according to the blending ratio shown in Table 1, and the obtained grease was evaluated by the following method. (1) Mixing Consistency: According to JIS K 2220 (2) Water-containing 10% Shell Roll: ASTM D1831
According to the test, perform a test at 80 ℃ × 168hr at 25 ℃
1/4 miscibility (JIS K 2220) is measured. As a accelerating condition, add 10% of water to grease,
The test was performed. (3) Bearing lubrication life: Tested at 200 ° C. according to ASTM D1741. The bearing weight before and after the test was measured, and the residual grease amount was calculated by the following formula.

[0026] Example 1-5 Half of the base oil and the total amount of monoamine shown in Table 1 were placed in a reaction vessel and heated to 70 ° C to 80 ° C. Half the amount of base oil and the total amount of diisocyanate were placed in a separate container and heated to 70 ° C to 80 ° C, which was added to the reaction container and stirred. The contents were stirred for about 30 minutes, and the contents were kept at 175 ° C to 185 ° C for 30 minutes and then cooled to room temperature. This was kneaded with a three-roll mill to obtain a grease composition. Comparative Example 1-2 A grease composition was obtained in the same manner as in Example 1-5 using the known base oils shown in Table 1.

The alkyl meta-triphenyl thioether compound shown as a base oil in the examples has a kinematic viscosity at 40 ° C. of 100 mm ² / s, a viscosity index of 120 and a flash point of 296.
It is a synthetic oil with the property of ℃. The tolylene diisocyanate used in the synthesis of urea was a commercial product.

When the examples and the comparative examples are arranged, the residual amount in the bearing lubrication life test (200 ° C.) is good in all the examples, and there is a marked difference from the comparative examples. In the comparative example, the heat resistance of the base oil was insufficient and the softening due to heat was remarkable, and the problem became apparent in practical use.

[0029]

As described above, the grease composition of the present invention is a grease composition comprising a base oil containing a polyphenylthioether compound represented by the general formula [1] which is a novel compound as a main component, and a thickener. It is a product, and has little evaporation and oxidation at high temperature, and has achieved high temperature and long life.

[0030]

[Table 1] Remarks * 1 C ₁₄ m-3P2T: alkyl triphenyl thioether ^{100mm 2 / s @ 40 ℃ *} 2 C 12 / C 14 -2P1E: mixed alkyl diphenyl ether ^{100mm 2 / s @ 40 ℃ *} 3 MDI: diphenylmethane 4,4-diisocyanate * 4 TDI: Tolylene diisocyanate * 5 PET: Pentaerythritol

Claims (1)

[Claims] 1. A compound of the general formula [1] (In the formula, R are the same or different and each is a hydrocarbon group having 1 to 24 carbon atoms, and n is an integer of 1 to 4.) A base oil containing a compound as a main component and a thickener. A grease composition comprising.