JPS6142594A - Gear oil composition containing graphite - Google Patents

Abstract

PURPOSE:A gear oil composition capable of reducing friction and wear remarkably when applied to gears used under high-speed and high-load conditions, made by incorporating graphite and an organotin compound in addition to a conventional sulfur-phosphorus additive into a base oil. CONSTITUTION:About 0.3-3pts.wt. (on the sulfur basis) sulfur compound (e.g. sulfurized oil), about 0.02-3pts.wt. (on the phosphorus basis) phosphorus compound (e.g. a diester of phosphorous acid), about 0.1-20pts.wt. graphite (preferably having a vinyl monomer grafted onto its surface) of an average particle diameter of about 1.5mum or less, and about 0.1-10pts.wt. organotin compound [e.g. dioctyltin (octyl thioglycolate)] are incorporated into 100pts.wt. base oil mainly composed of mineral oil [having a dynamic viscosity (at 40 deg.C) of about 30-4,000cSt].

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application in the Cfri Industry] This invention relates to a gear oil composition that is used industrially and is used to reduce B friction and part of gears, thereby saving energy.

[Conventional technology]

In recent years, various types of modification equipment used in industry have become larger.
In addition, as speeds increase, mechanical elements such as shafts, bearings, and gears that are used with a power value of 11 tons are gradually being used at high speeds and high loads, and the gear oil used in such gear devices is also changing. -F
M fli is now being celebrated.

Gear oils used for this purpose include sulfur-based,
Additives such as phosphorus-based, lead soap-active sulfur-based, sulfur-chlorine-phosphorus-based, sulfur-chlorine-phosphorus-zinc-based, sulfur-phosphorus-based additives, or mixtures of some of these have been proposed. Furthermore, gear oils to which molybdenum disulfide is partially added have been proposed for use in high-load mechanical devices.

By the way, today, among these, those containing sulfur-phosphorus additives are most commonly used.
A graphite-containing gear oil in which graphite is added has also been proposed (Japanese Unexamined Patent Publication No. 58-96697).

In addition to the above-mentioned gear oils, 12 lubricating oil compositions containing tin compounds have also been proposed to fully exhibit the effects of both extreme pressure agents and anti-wear agents (Japanese Patent Application Laid-Open No. Tube No. 57-3894, Tube No. 57-3895M and Tube No. 5
7-3895).

[Problem that the invention seeks to solve]

However, the gear oils mentioned above, especially gear oils containing sulfur-phosphorus additives, exhibit satisfactory performance in terms of thermal stability, oxidation stability, water separation, low toxicity, and corrosion resistance. However, the performance required for gear oils used in gears operated under particularly severe conditions at high speeds and high loads, namely, performance such as prevention of gear wear reduction, smoothing of rough gear surfaces, and low friction. However, the performance of any of the gear oils mentioned above is still insufficient, and there is a strong demand for the development of a gear oil suitable for the power transmission mechanism of the mechanical devices used in today's industry. It became so.

[Means for solving problems]

In view of this, the present invention has been developed to utilize the properties of conventional gear oils containing sulfur-phosphorus additives, such as thermal stability, water separation properties, low temperature properties, and corrosion resistance, and to improve the performance of gear oils used in high-speed, high-load machines. It provides a gear oil that can be used in equipment, and is a graphite-containing gear oil composition made by blending a sulfur compound, a phosphorus compound, graphite, and an organic tin compound with a base oil.

In the present invention, J3 used as a base oil is mineral oil or a mineral oil-based base oil, and if necessary, it can be used as a lubricating oil such as polystyrene, polyisobutylene, polybutene, polymethacrylate, etc. Commonly used thickeners may be added and mixed to adjust the viscosity. Further, if necessary, a suitable pour point depressant may be added. Since industrial gear oil usually has a kinematic viscosity of about 30 to 4,0 OOcSt (centistokes) at 40°C, the above-mentioned mineral oil may also have a kinematic viscosity within this range; A base oil may be prepared by mixing a known poly-α-olefin type, synthetic ester type, etc. to be used as an auxiliary oil.

Examples of the sulfur compounds to be added to the above base oil include sulfurized olefins, which are obtained by sulfurizing olefin polymers and usually have a sulfur content of 10 to 5C1♀%, sulfurized fats and oils, sulfurized esters, etc. can be mentioned. These sulfur compounds may be used alone or in combination of two or more. Regarding the usage amount of the above sulfur compound, the sulfur content is usually 0.3 parts per 100 parts of base oil.
~3!12 claws, preferably 0.3 to 2 claws.

The phosphorus compounds that are blended into the base oil along with this sulfur compound include phosphorous diester, phosphorous triester, phosphonic acid ester, orthophosphoric acid ester, pyrophosphoric acid ester, acidic phosphoric acid ester, and acidic phosphoric acid ester amine salt. Alkyl or aryl phosphate ester compounds such as
Alkylthiophosphates having an alkyl group of carbon a1 to a18, phosphoric acid ester compounds of acidic thiophosphate esters, or alkylthiophosphates such as completely neutralized salts or partially neutralized salts of these alkyl amines, carbon atoms of 1 to 18 Alkylthiophosphates having 18 alkyl groups, phosphoric acid ester compounds or thiophosphoric acid ester compounds of acidic dithiophosphoric acid esters, or alkylthiophosphates such as completely neutralized salts or partially neutralized salts of these alkyl)nomines, carbon number Phosphoric acid ester compounds or thiophosphoric acid ester compounds of acidic didiophosphoric acid esters having two alkyl groups of 1 to 18, or sialic acid such as 4; Examples include esters. These phosphorus compounds may be used alone (or may be used in combination of two or more types.Also, the amount of the above phosphorus compound used is usually 100 parts by weight of base oil. The phosphorus content is 0.02 to 0.3 parts by weight, preferably 0.02 to 0.1 parts by weight.

Furthermore, the graphite used in the present invention has an average diameter of 3 μm.
The following is preferably a material with a particle size of 1.5 μm or less, and more preferably a graphite-g4 fat graft obtained by graft polymerizing a vinyl monomer onto the surface of graphite from the viewpoint of dispersion stability and demulsifying property. It is hand-made composite gold powder. The amount of graphite used is usually 0.1 to 100 parts of base oil.
20 car mother part.

Preferably it is 0.1 to 5 parts.

Furthermore, the organotin compound used together with the graphite is a wired compound containing tin in the compound, and is preferably a compound soluble in base oil. Such organotin compounds include the following general formula (1) group or -(CH) GOO
represents an R group, n R3 is an alkyl group, an alkenyl group, a cycloalkyl group,
It represents an alkoxyalkyl group or a benzyl group, and m is 1 to
Indicates an integer of 3, and n is 1 or 1. Indicates t2. ] and the alkyltin compounds represented by the following general formulas (a) and (
b) has at least one atomic group represented by R-8n-8R0-P-----(a) the following general formula (2
) to (16) % formula %) [In the above general formulas (a), (b) and (2) to (16),
R1 and R3 represent alkyltin, R2 and R4 represent alkylene, X represents an oxygen atom or a sulfur atom, and R5
-R13 represents hydrogen, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylaryl group, an arylalkyl group, or a substituent in which the hydrogen atom bonded to these carbon atoms is substituted with flukoxy. ) or an atomic group represented by the following general formula (C), R-3n-
3ll 0-8- --- (c) The following general formula (11)
~ (27) % formula %) [In the above general formulas (c) and (11) to (27), R1 represents an alkyl group, R2 represents an alkylene group, OR3
~OR8 is a hydroxyl group, an alkyloxy group, an alkenyloxy group, or a cycloalkyloxy group, and the hydrogen atom bonded to these carbon atoms is substituted with a hydroxyl group, a mercapto group, an alkyloxyoxy group, a hydroxyalkyl group, an aryl group, or an alkylaryl group Y
and Y2 represents oxygen or an alkylenedioxy group. ] Examples include organotin boric ester compounds represented by the following, including silver dibutyldithiophosphate, silver di-2-ethylhexyldithiophosphate, silver diphenyldithiophosphate, dibutyltin dibutyl ester, and di-2-ethylhexyldithiophosphate.
Silver dialkyl or diaryl dithiophosphate such as ethylhexyltin dithiophosphate di-2-ethylhexyl ester, diphenyltin dithiophosphate diphenyl ester, dibutyldithiojJ silver dithiophosphate, di-2-ethylhexyltin dithiocarbamate, dibutyltin dithiocarbamate, dibutyltin dithiocarbamate, There are sialyl mates such as 2-ethylhexyltin didiocarbamine and di-2-ethylhexyl, and all organic compounds containing tin can be used.

These organotin compounds can be used alone,
Also, two types of one stroke may be used in combination.

In addition, regarding the usage amount of the above-mentioned compound of tin 1, base oil 1
The amount is usually 0.1 to 10 m parts, preferably 0.1 to 5 parts by weight (λ·1). By coexisting with the above-mentioned graphite, these organotin compounds particularly improve wear resistance and I! i! Demonstrates friction-reducing properties.

In the gear oil composition of the present invention, in addition to the above-mentioned sulfur compound, phosphorus compound, graphite, and organotin compound, various third additives may be blended for the purpose of improving the properties required as a gear oil.

Examples of the third additive used for this purpose include metal deactivators, rust preventives, demulsifiers, antifoaming agents, and the like. Examples of the above-mentioned metal deactivators include benzo 1-
The amount of lyazole derivatives is usually 0 per 100 parts by weight of base oil.
．． 01 to 1 part by weight, preferably 0.05 to 0.5 part by weight, and the above-mentioned rust preventive agent is, for example, a sulfonate optical reading conductor or a succinic acid ester derivative. In
Usually 0.05 to 1 part per part, preferably 0.

05~0.5! As the demulsifier, for example, an anionic, cationic, or nonionic surfactant is used, usually in an amount of 0.003 to 2 parts by weight, preferably 0.003 to 1 part by weight, per 100 parts by weight of the base oil. In addition, as an antifoaming agent, for example, a silicone-based conductor is usually used in an amount of 0.001 to 0.000 parts by weight per 100 parts by weight of base oil. "lffll, preferably 0.002-0.

05 parts by weight can be used.

〔Example〕

Hereinafter, the present invention will be specifically explained based on typical examples.

[Examples 1 to 4 and comparison! Preparation of I41-8 gear oil Example 1 A base oil was prepared by mixing 500 neutral oil and bright stock oil, which were lubricating oils with the properties shown in Table 1, in a weight ratio of 50:50.

To 100 parts by weight of this base oil, 1% by weight of polylaurylmethacrylate, 0.5 parts by weight of grafted graphite, and dioctyltin bis (as a sulfur-containing alkyltin compound (A))
-f-A octyl glycolate) 1.

0 parts by weight and 1 as the sulfur content of the sulfurized olefin.

01 part and Nisdel phosphate as phosphorus content 0.

06 parts by weight were added and mixed to obtain a working IW1 gear oil. The properties of the obtained Example 1 gear oil are shown in Table 2.

Table 1 Example 2 Polylauryl methacrylate 1 used in Example 1 above
Example 2 gear oil was obtained in the same manner as Example 1 by using commercially available graphite (product name: 5LA-1255 manufactured by Nippon Acheson ■) instead of lff1% grafted graphite.The obtained Example 2 gear oil The properties are shown in Table 2.

Example 3 The sulfur-containing alkyltin compound (A
Example 3 gear oil was obtained in the same manner as in Example 1 except that the same type of dilauryltinbis(lauryl thioglycolate) was used instead of . The properties of the obtained Example 3 gear A7 oil are shown in Table 2.

Example 4 The sulfur-containing alkyltin compound (A
Example 4 gear oil was obtained in the same manner as in Example 1 except that an alkyl tin boric acid ester was used in place of the above. The properties of the obtained Example 4 gear oil are shown in Table 2.

Comparative Example 1 1% by weight of polylauryl methacrylate and 0.5% grafted graphite based on 100 parts by weight of the base oil used in Example 1 above.
The sulfur content of the olefin is reduced to 1. O
ilYm part and phosphoric acid ester as phosphorus content 0.06
Comparative example 1 gear oil was added and mixed with
7k. Table 2 shows the properties of the comparative example 1 gear oil.

Comparative Example 2 To 100 parts of base oil used in Example 1, 1.0 parts by weight of sulfur-containing alkyltin compound <A), 1.0 parts by weight of sulfurized olefin as sulfur content, and phosphoric acid. Comparative Example 2 gear oil was obtained by adding and mixing 0.061 m part of ester with a phosphorus content. The properties of the obtained Comparative Example 2 gear oil are not shown in Table 2.

Comparative Example 3 To 100 parts by weight of the base oil used in Example 1, 1 part by weight of lead dialkyl dithiocarbamate, 1.0 parts by weight of sulfurized olefin as sulfur content, and 0 parts of phosphoric acid ester as phosphorus content. .

Comparative Example 4 Commercially available SP gear oil (fl! i degree grade ■5OVG
220> was used as Comparative Example 4 gear oil. The properties of this Comparative Example 4 gear oil are shown in Table 2.

Comparative Example 5 Commercially available graphite-containing gear oil (viscosity grade 15OVG 2
20) was used as Comparative Example 5 gear oil. The properties of this Comparative Example 5 gear oil are shown in Table 2.

Comparative Example 6 Sulfur-containing alkyltin compound used in Example 1 <A
) was replaced with zinc di-2-ethylhexyldithiophosphate, and Comparative Example 6 gear oil was fy7.

The properties of the obtained Comparative Example 6 gear oil are shown in Table 2.

Comparative Example 7 The sulfur-containing al-4-nyltin compound used in Example 1 above (
In place of A), a wired molybdenum compound of 0.5'f' [im% was used, and Comparative Example 7 gear oil was 171. 1′:I
The properties of the Comparative Example 7 Gi 17 oil are not shown in Table 2.

Comparative Example 8 The sulfur-containing alkyltin compound (A
), using 1% by weight of a boron compound, Comparative Example 8
GiX? I got oil. ) The properties of Comparative Example 8 gear oil are shown in Table 2.

[Performance test of the gear oil of each Example and each Comparative Example] The gear oil of each of the above Examples and Comparative Examples was subjected to a wear test using a Farex friction/wear tester manufactured by Flex Co., Ltd. under the following conditions. , a during the exam! The friction coefficient, the abrasion coefficient at the end of the test, and the surface roughness of the sliding part were measured. The results are shown in Tables 3 and 4.

Test conditions test block: 8 ISI C-1137, IIRc
20-24 test bin: Al5I 3135
, IIRB 87-91 rpm @: 290rp
m Load: 5001bf Test time: 30 minutes Lower a than commercially available Comparative Examples 4 and 5 gear oil! The friction coefficient is shown.

Furthermore, as is clear from Table 4, the gear oils of Examples 1 to 4 showed improvement in both surface roughness and wear m when compared with commercially available comparative examples 4 and 5 gear oils, regardless of whether they were J5. In addition, when compared with Comparative Examples 1 to 3, the results of Comparative Example 1 gear oil in which graphite was added showed that the wear resistance was improved by the addition of graphite, and the results of Comparative Example 2 gear oil in which organotin compounds were added and Comparative Example 6. From the results of Examples 1 to 8, the smoothness was improved by adding the organotin compound, and from the results of Examples 1 to 4, the addition of both exhibited a synergistic effect.
It was found that the effects of reducing wear and improving surface smoothness were significant.

〔Effect of the invention〕

The graphite-containing gear oil composition of the present invention contains graphite and an organotin compound in coexistence without impairing the properties of conventional gear oils such as thermal stability, water separation, low toxicity, and corrosion resistance. It exhibits a synergistic effect and achieves the performance required for gear oils used in high-speed, high-load gears, such as preventing damage to the base metal of the gear, smoothing the gear surface, positive load capacity, low W, and ring coefficient. It is also a gear oil that can significantly improve this and is suitable for power transmission devices of various mechanical devices used in today's industry.

Claims (4)

[Claims] (1) A graphite-containing gear oil composition characterized in that a sulfur compound, a phosphorus compound, graphite, and an organic tin compound are blended in a base oil. (2) The graphite-containing gear oil composition according to claim 1, wherein graphite is blended in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the base oil. (3) The graphite-containing gear oil composition according to claim 1 or 2, wherein the graphite is a graphite-resin graft polymer obtained by graft polymerizing a vinyl monomer onto the surface of the graphite. (4) Organotin compound content is 0.1 per 100 parts by weight of base oil
The gear oil composition containing graphite according to any one of claims 1 to 3, wherein the graphite-containing gear oil composition is blended in an amount of 10 parts by weight.