JPH0978078A - Grease composition for open gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a grease composition for open gears excellent in forced feedability and lubricity by adding an organomolybdenum compound, an organozinc compound, graphite, calcium carbonate and a vegetable oil and fat in a specific proportion to a grease composition comprising a mineral oil- based lubricating oil, etc. SOLUTION: This grease composition for open gears is obtained by adding (A) 1-5wt.% organomolybdenum compound such as molybdenum oxysulfide organophosphorodithioates, (B) 0.5-1.5wt.% organozinc compound such as zinc dialkyl dithiophosphate, (C) 5-15wt.% graphite such as natural graphite, (D) 1-5wt.% calcium carbonate such as precipitated calcium carbonate light and (E) 2-6wt.% vegetable oil and fat such as castor oil to a grease composition comprising a mineral oil-based lubricating oil and a thickener such as a soap- based thickener.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a grease composition for open gears, particularly spraying on a lubricated part of a large open gear such as a rotary kiln of a cement plant and a mill of a mining machine or a construction machine without heating or diluting with a solvent. The present invention relates to a grease composition which can be lubricated and has excellent lubricity.

[0002]

2. Description of the Related Art Generally, open gears are lubricated by hand coating or dipping in an oil bath. However, centrifugal force is generated when the tooth surface is damaged due to insufficient oil film or due to the viscosity of the lubricant used. It may be shaken off by the water and stain the surroundings. To prevent these, a highly viscous and highly adherent lubricant is required.
Further, in the case of large open gears, a lubricant that can prevent the excess and deficiency due to the labor and machine operation rate and can uniformly spray oil is required.

To these places of use, asphalt-based solvent-diluted conbounds have been used. This solvent type asphalt compound enhances fluidity with a solvent, facilitates pressure feeding and spray lubrication, and after spraying, the solvent evaporates and the excellent adhesion of the asphalt,
A highly viscous lubricating oil film is formed. Recently, due to environmental problems, there is a demand for deasphalting from the viewpoint of eliminating solvents or cleaning the working environment.

It is very difficult to meet these demands with a mineral oil type grease. Extreme pressure grease, which is mainly based on extreme pressure, has poor adhesion and adhesiveness, resulting in large friction on the tooth surface, and a large amount of polymer-containing gear grease has poor pumpability and has the problem that it cannot be lubricated. .

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a grease composition for oven gears which does not contain a solvent or asphalt and is excellent in pumpability and lubricity.

[0006]

SUMMARY OF THE INVENTION The inventors of the present invention have, as a subject, how to form a strong and stable oil film in order to maintain lubricity similar to that of asphalt when using a mineral oil type lubricating oil. , In the lab evaluation test, using a shell four-ball tester and a Chimken tester, the lubrication characteristics of various additives, solid lubricants or combinations of each additive are examined.
On the other hand, the pumpability was confirmed using an apparent viscosity tester.
As a result, the present inventors have found that an additive, a solid lubricant, and a combination thereof form an extremely strong and stable oil film even when a mineral oil-based lubricating oil is used, and that excellent lubricating performance is obtained. . Furthermore, an actual machine test was conducted, and it was confirmed that even if a mineral oil-based lubricating oil was used, the performance equal to or higher than that of the asphalt-based compound could be exhibited, and the present invention was completed.

That is, according to the present invention, a grease composition comprising a mineral oil-based lubricating oil and a thickener is added to an organic molybdenum compound in an amount of 1 to 5 wt% and an organic zinc compound in an amount of 0.5 to 1.5 wt.
%, Graphite 5-15 wt%, calcium carbonate 1-5 wt
%, Vegetable oils and fats 2 to 6 wt%, and a grease composition for open gears.

Although the present invention is based on a mineral oil-based lubricating oil and a thickener, any mineral oil-based lubricating oil or thickener can be used. For example, mineral oil-based lubricating oils are usually used in greases, and thickeners include soap-based thickeners typified by Li soap, and complex soap-based thickeners and diurea. Inorganic thickeners such as urea-based thickeners, bentonite, and silica are mentioned. It is preferable that the base grease as the base material be selected in consideration of the temperature conditions used.

The organo-moliden compound used in the present invention is a general term for organometallic load-bearing additives having a metal group of moridevene, and its representative is represented by the following structural formula (I). Sulfurized oxymolybdenum organophosphorodithioates

Embedded image (In the formula, R ¹ and R ² are the same or different and each represents a saturated or unsaturated hydrocarbon group having 1 to 30 carbon atoms, m is a number of 1 to 3, and n is 1 to 1). 3 and the sum of m and n is 4) and sulfurized oxymolybdenum dialkyldithiocarbamates represented by the following structural formula (II)

Embedded image (In the formula, R ³ and R ⁴ are the same or different and each represents an alkyl group having 1 to 24 carbon atoms, and x is 1
To 3 and y is a number from 1 to 3 and the sum of x and y is 4.).

In the above formula (I), the hydrocarbon group represented by R ¹ and R ² may be saturated or may contain an unsaturated bond, and may be linear or branched. It may be chain-type or chain-type or any combination thereof and has 1 carbon atom.
-30, preferably 1-20 are suitable.
However, such hydrocarbon groups include aliphatic, aromatic and aromatic-aliphatic groups, and specifically,
For example, an alkyl group having 1 to 20 carbon atoms, particularly 3 to 8 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, 2-methylbutyl, hexyl, 2-ethylhexyl, octyl, nonyl, stearin; Propenyl, butenyl, isobutenyl, pentenyl, 2-ethylhexenyl, octenyl, oleyl and like alkenyl groups having 2 to 20 carbon atoms, preferably 3 to 8 carbon atoms; cyclopentyl, cyclohexyl, methylcyclopentyl, ethylcyclopentyl, toluyl, nonylphenyl, A cycloalkyl group having 5 to 8 carbon atoms such as;
Aryl groups such as phenyl, naphthyl, and alkyl-substituted phenyl groups (the alkyl substituents include those having 1 to 20 carbon atoms, preferably 4 to 9 carbon atoms); benzyl, phenethyl, CH ₃ -C _{6 H 4 CH 2 -, C 2} H 5 -
_{C 6 H 4 CH 2 -,} C 2 H 5 -C 6 H 4 C 2 H 4 -, C 2 H 5 -C 6
_{H 4 C 3 H 6 -,} C 2 H 5 -C 6 H 4 C 4 H 8 -, C 2 H 5 -C 6 H
7 carbon atoms such as ₄ C ₅ H _10- , CH ₃ -C ₆ H ₄ C ₅ H _10-, etc.
-20, especially 7-20 aralkyl groups are mentioned. Among them, R ¹ and R ² are preferably propyl, butyl, pentyl, isopentyl, hexyl, 2-ethylbutyl, 2-ethylhexyl, 2-propylhexyl, nonylphenyl and the like. Further, m and n in the formula (I) are usually 2 respectively, but m = 1 and n = 3, or m = 3 and n = 1 may be produced depending on the production conditions. The compounds of) can be present as any mixture of m = 2 and n = 2, m = 1 and n = 3 and m = 3 and n = 1. No. 24562. ].

Representative examples of organomolybdenum compounds of formula (I) which can be used in the present invention include the following: sulfurized oxymolybdenum propyl phosphorodithioate, sulfurized oxymolybdenum butyl phosphorodithioate, sulfurized. Oxymolybdenum pentyl phosphorodithioate, sulfurized oxymolybdenum hexyl phosphorodithioate, sulfurized oxymolybdenum octyl phosphorodithioate, sulfurized oxymolybdenum 2-ethylhexyl phosphorodithioate sulfurized oxymolybdenum decyl phosphorodithioate, sulfurized oxymolybdenum lauryl phosphoro Dithioate, sulfurized oxymolybdenum stearyl phosphorodithioate, sulfurized oxymolybdenum butenyl phosphorodithioate, sulfurized oxymolybdenum pentenyl phosphorodithioate , Sulfurized oxymolybdenum 2-ethylhexenyl phosphorodithioate, sulfurized oxymolybdenum oleyl phosphorodithioate, sulfurized oxymolybdenum cyclopentyl phosphorodithioate, sulfurized oxymolybdenum cyclohexyl phosphorodithioate, sulfurized oxymolybdenum methylbenzyl phosphorodithioate, sulfurized Oxymolybdenum ethyl phenyl phosphorodithioate, sulfurized oxymolybdenum phenyl phosphorodithioate, sulfurized oxymolybdenum nonyl phenyl phosphorodithioate, sulfurized oxymolybdenum hexyl phenyl phosphorodithioate, sulfurized oxymolybdenum phenethyl phosphorodithioate, sulfurized oxy Molybdenum stearyl phenyl phosphorodithioate, sulfurized oxymolybdenum ethyl cyclopentyl phosphoro Thioate, etc. sulfurized oxymolybdenum propylcyclopentyl phosphorodithioate.

On the other hand, the alkyl group having 1 to 24 carbon atoms represented by R ³ and R ⁴ in the formula (II) may be of either linear or branched type. Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, 2ethylpropyl, 2ethylhexyl, lauryl, palmityl, 2propyllauryl, stearyl, decyl, etc., among which 3 to 8 carbon atoms are included. Are preferred. Further, x and y in the formula (II) have the same meanings as m and n in the formula (I). Therefore, the following can be mentioned as typical examples of the organic molybdenum compound of the formula (II) that can be used in the present invention.
Oxymolybdenum sulfide 2 ethylhexyl dithiocarbamate, oxymolybdenum ethyl dithiocarbamate sulfide, oxymolybdenum propyldithiocarbamate sulfide, oxymolybdenum isopropyldithiocarbamate sulfide, oxymolybdenum butyldithiocarbamate sulfide, oxymolybdenum isobutyl dithiocarbamate sulfide, oxymolybdenum pentyl dithiocarbamate sulfide, Oxymolybdenum isopentyl dithiocarbamate, oxymolybdenum hexyl dithiocarbamate, oxymolybdenum 2-ethylpropyl dithiocarbamate, oxymolybdenum nonyldithiocarbamate, oxymolybdenum 2-propylhexyldithiocarbamate, oxymolybdenum 2-propylpentyldithiocarbamate Oxymolybdenum lauryl dithiocarbamate, sulfurized oxymolybdenum palmityl dithiocarbamate, sulfurized oxymolybdenum stearyl dithiocarbamate, sulfurized oxymolybdenum 2-methyllauryl dithiocarbamate, sulfurized oxymolybdenum 2-methylstearyl dithiocarbamate, sulfurized oxymolybdenum 2butyl palmityl dithiocarbamate, sulfurized Oxymolybdenum 2-butyl stearyl dithiocarbamate etc.

The organic molybdenum compounds represented by the above formulas (I) and (II) can be used alone or in combination of two or more kinds.

The organozinc compound used in the present invention is a general term for organometallic load-bearing additives having a metal group of zinc, and its representative is represented by the structure represented by the following general formula (III). It is an organometallic compound.

Embedded image [Wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ represent the same or different primary, secondary and tertiary alkyl groups or aryl groups each having 1 to 20 carbon atoms, Alkyl groups are preferred. ]

Specific examples of the organic zinc compound include zinc dithiophosphates such as zinc dialkyldithiophosphate and zinc diaryldithiophosphate.

The graphite used in the present invention is a graphite powder known as a solid lubricant, and is roughly classified into natural graphite produced naturally and purified artificial synthetic graphite, both of which can be used. Is.

The calcium carbonate used in the present invention is widely used as a filler for rubber, paint, etc., and is roughly classified into heavy calcium carbonate and light calcium carbonate, but light calcium carbonate is more preferable. .

Examples of vegetable oils and fats used in the present invention include glyceroid-containing substances such as castor oil, soybean oil, rapeseed oil and coconut oil.

Further, the grease composition of the present invention may contain various additives such as a polymer, an antioxidant and a rust preventive, if necessary.

Regarding the amount of addition used in the present invention, the effect of the addition of an organometallic load-bearing additive of an organomolybdenum compound and an organozinc compound can be examined particularly by the evaluation of the Timken type lubricity test. . However, if the addition amount is less than 1 wt% and 0.5 wt% respectively, the effect is small, and if the addition amount is more than 5 wt% and 1.5 wt% respectively, the effect is not further increased and the corrosiveness is increased. Since such side effects occur,
The ranges of 1 to 5 wt% and 0.5 to 1.5 wt% are suitable.

The addition of solid lubricants of graphite and calcium carbonate is especially described by W. P. You can see the effect of increasing. However, if the added amount is less than 5 wt% and 1 wt%, respectively, the effect is small.
Even if added in an amount of more than 5 wt%, the effect is not further increased, and the thickening property of the powder deteriorates the pumpability and adversely affects the rust prevention property.
The range of wt% and 1 to 5 wt% is suitable.

The addition of an oily agent for vegetable fats and oils is particularly effective when used in combination with a solid lubricant such as graphite in the evaluation of the Timken type lubricity test. As a result, the range of 2 to 6 wt% is preferable.

[0023]

The present invention will be described with reference to the following examples and comparative examples, but the present invention is not limited thereto. Add the additives shown in Table 1 and Table 2 to the base grease,
Kneading was performed with a three-stage roll mill to produce the grease of each of the examples and comparative examples.

The physical properties and performance were evaluated by the following methods. The results are shown in Tables 3 and 4. (1) Worked penetration JIS K 2220 5.3 (2) Drop point JIS K 2220 5.4 (3) Shell four-ball test W. P. ¹⁾ ASTM D 2596 (4) Timken-type lubricity test Conforms to JIS K 2220 5.16 Using a Timken-type load-bearing performance (JIS K 2220 5.16) tester, 1 g of grease is applied to a cup or block and 30 Lb Drive for 10 minutes. During operation, measure the block temperature without grease reinforcement. After 10 minutes, the wear of the block is evaluated for the presence or absence of scoring and temperature. (5) Apparent viscosity JIS K 2220 5.15 (6) Actual machine test Company A cement factory Kiln (viscosity dryer) / Nipponkai Heavy Industries, Ltd. Measurement items Mixing consistency, dropping point, iron content (atomic absorption method) ¹⁾ W. P. weld point fusion load

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3] ¹⁾ W. P. Weld point Fusion load ²⁾ N Newton (load unit) ³⁾ 2W Sampling after 2 weeks ⁴⁾ 4W Sampling after 4 weeks

[0028]

[Table 4]

(Note) 1) Base grease 1 Thickener: Lithium soap 4% Mineral oil: Hydrogenated refined mineral oil having a kinematic viscosity of 450 mm ² / s at 40 ° C. Consistency: No. 0 grade (60w 370) 2) Base grease 2 Thickener: Silica 4% Mineral oil: Hydrogenated refined mineral oil having a kinematic viscosity of 450 mm ² / s at 40 ° C. Consistency: No. 1 Grade (60w 340) 3) Organic molybdenum compound (trade name MOTYVAN ART VANDER RBILT) 4) Organic zinc compound (trade name: LUBRIZOL 1360 Nippon Lubrisol Co., Ltd.) 5) Graphite 1 (trade name) : Artificial graphite G-6M manufactured by Fuji Graphite Industry Co., Ltd.) 6) Graphite 2 (Product name: Graphite FAG-1 manufactured by Fuji Graphite Industry Co., Ltd.) 7) Calcium carbonate (Product name: Escalon 2000 Sankyo Milling Co., Ltd.) 8) Vegetable oil (trade name: castor oil, manufactured by Toyokuni Oil Co., Ltd.) ^{* 1} Commercially available asphalt compound This commercially available product is a solvent-diluted type and practically shows the data after the solvent has evaporated. For comparison, the data when the solvent is contained (that is, before use) is shown in parentheses. 2-1 Kinematic viscosity at 40 ° C. 8000 mm ² / s (1800 mm ² / s) 2-2 Mixing consistency 410 (> 440) 2-3 Dropping point data not available (data not available) 2-4 Shell 4 sphere 4903N (data not available) ) 2-5 Apparent viscosity (-10 ° C) No data (No data) [Solvent evaporation condition 80 ° C x 2h (vacuum low temperature dry product used) Evaporation loss 13wt%] ^{* 2} Commercial product Large amount of polymer grease for grease 40 ° C Kinematic viscosity of 2300 mm ² / s ^{* 3} Timken type lubricity test result Evaluation 1: Block wear Scoring with or without scoring Symbol Scoring 〇: None ×: Yes Evaluation 2: Block temperature Symbol 〇: Less than 150 ° C △ : 150 ℃ or more ×: Baking

[0030]

EFFECTS OF THE INVENTION The grease composition for open gears of the present invention has a stable and strong combination of an organometallic load-bearing additive, a solid lubricant and an oily agent, even if a mineral lubricating oil is used. A grease that can form a large oil film and has the same or higher performance as an asphalt compound and can be sufficiently applied to the lubrication part of large open gears was obtained.

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Claims (1)

[Claims] 1. A grease composition comprising a mineral oil-based lubricating oil and a thickener is added to an organic molybdenum compound in an amount of 1 to 5 wt%,
Organozinc compound 0.5-1.5wt%, graphite 5-15w
t%, calcium carbonate 1-5 wt%, vegetable oil 2-6w
A grease composition for an open gear, containing t%.