JPH0246635B2 - SHITSUSHIKIKURATSUCHOMATAHASHITSUSHIKIBUREEKYOJUNKATSUYUSOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lubricating oil composition for wet clutches or wet brakes, and more specifically, it relates to a lubricating oil composition for wet clutches or wet brakes, which has good frictional properties, little change in frictional properties due to oil temperature or aging, and good oxidation stability, corrosion prevention ability, etc. The present invention relates to a lubricating oil composition for brakes or wet brakes. The frictional characteristics referred to here are not the usual frictional coefficients, but the ratio of the static frictional coefficients to the dynamic frictional coefficients, and the smaller this ratio is, the better the frictional characteristics are. Lubricating oils used in wet clutches of automatic transmissions, wet brakes of agricultural tractors, etc. are required to have good friction properties, thermal oxidation stability, corrosion resistance, and rust prevention properties. Therefore, lubricating oils using friction modifiers have been proposed to improve frictional properties. However, lubricating oils using friction modifiers still have insufficient frictional properties, and their frictional properties deteriorate due to changes in oil temperature and oil deterioration (change over time) due to long-term use. I had a problem with putting it away. Furthermore, there were also disadvantages in that the oxidation stability was reduced and the corrosion prevention ability was deteriorated. On the other hand, in recent years, due to the miniaturization of automobiles and the rapid increase in the number of front-wheel drive vehicles, automatic transmissions have become more sensitive to the human body. This has led to the need for further improvements in frictional properties. Therefore, the present inventors conducted extensive research into a lubricating oil composition for wet clutches or wet brakes that satisfies these required characteristics, and found that by incorporating a specific combination of compounds into the base oil, the lubricating oil composition for wet clutches or wet brakes can be made to meet the desired characteristics. Alternatively, the inventors discovered that a lubricating oil composition for wet brakes can be obtained, and based on this knowledge, they completed the present invention. That is, the present invention provides a base oil containing (A) a type of phosphoric acid ester or an amine salt thereof represented by the following general formulas [], [], and []. (In the above formulas [], [] and [],
R ¹ and R ² represent an alkyl group having 4 to 30 carbon atoms, a phenyl group, or an alkyl-substituted phenyl group, and R ¹ and R ² may be the same or different. ) and (B) (a) Esters of sorbitan with fatty acids having 12 to 24 carbon atoms, (b) Esters of glycerin and fatty acids having 12 to 24 carbon atoms, (c) Palm kernel oil fatty acids, (d) Coconut oil fatty acids , (e) a compound consisting of the general formula (RCOO) ₂ Zn (in the formula, R represents a fatty acid having 12 to 24 carbon atoms or a fat or oil fatty acid), (f) a compound consisting of a fat or oil and a fatty acid having 12 to 24 carbon atoms, former 5
~95: the latter in a ratio of 95 to 5 (weight ratio); and (g) diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, hexaethyleneheptamine, heptaethyleneoctamine, tetrapropylenepentamine and hexabutyleneheptamine A wet clutch characterized by containing one type of compound selected from the group consisting of a reaction product of a polyalkylene polyamine selected from the group consisting of: and a fatty acid having 12 to 30 carbon atoms or an oxidized mineral oil. The present invention provides a lubricating oil composition for use in brakes or wet brakes. In the present invention, the base oil is the main component of the lubricating oil composition, and any base oil commonly used in lubricating oils is not particularly limited, and synthetic oils, mineral oils, etc. can be used. The base oil preferably has a viscosity of 3 to 20 cst at 100°C. Specific examples of base oils include mineral oils such as 60 neutral oil, 100 neutral oil, 300 neutral oil, and 500 neutral oil produced by solvent refining or hydrogenation, and synthetic oils such as polyolefin, polyglycol ester, polyol ester, and phosphorus oil. These include acid esters, silicone oils, alkyl diphenyls, and dibasic acid esters. In the present invention, component (A) is a phosphoric acid ester or an amine salt thereof, which is added to the above-mentioned base oil mainly to obtain wear resistance and low friction properties. As the phosphoric acid ester of component (A), one represented by the following general formula is used.

【formula】

【formula】

[Formula] In the above formulas [] [] and [], R ¹
and R ² represents an alkyl group, phenyl group, or alkyl-substituted phenyl group having 4 to 30 carbon atoms,
R ¹ and R ² may be the same or different. Specific examples of phosphoric acid esters include butyl acid phosphate, 2-ethylhexyl acid phosphate, lauryl acid phosphate, oleyl acid phosphate,
Examples include stearyl acid phosphorite, dibutyl hydrogen phosphorite, dilauryl hydrogen phosphorite, dioleyl hydrogen phosphorite, distearyl hydrogen phosphorite, diphenyl hydrogen phosphorite, and the like. Examples of amine salts of phosphoric acid esters include oleylamine salts, coconut amine salts, tallow amine salts, and the like of the above-mentioned phosphoric acid esters. The amount of component (A) added varies depending on the desired characteristics of the intended lubricating oil composition, the compound used, etc., but is usually 0.01 to 5% by weight, preferably 0.1 to 2% by weight. If the amount of component (A) added is less than 0.01% by weight, there is no effect, and if it exceeds 5% by weight, the oxidation stability deteriorates, which is not preferable. As component (B) of the present invention, one or more compounds selected from the group of components (a) to (g) are used,
By adding it to the base oil in combination with component (A) above, the initial friction properties are good, i.e. the static friction coefficient/
This makes it possible to obtain a lubricating oil composition that has a small dynamic friction coefficient and whose value does not change due to fluctuations in oil temperature or oil deterioration (changes over time). Here, component (a) is an ester of sorbitan and a fatty acid having 12 to 24 carbon atoms, specifically sorbitan monolaurate, sorbitan monooleate,
Mention may be made of sorbitan monostearate, sorbitan sesquiolate, sorbitan dioleate or mixtures thereof. In addition, as component (b), glycerin and carbon number 12 ~
It is an ester with 24 fatty acids, specifically oleic acid monoglyceride, stearic acid monoglyceride, oleic acid diglyceride, or a mixture thereof. When using the above component (a) or (b) as component (B), the amount added is 0.05 to 5% by weight, preferably 0.1 to 5% by weight.
It is 3% by weight. If the amount added is less than 0.05% by weight, no improvement in friction properties will be observed, and if the amount exceeds 5% by weight, oxidation stability will deteriorate. Ingredient (c) is palm kernel oil fatty acid, which is used in the Philippines, Indonesia, Malaysia, Africa,
It is a fatty acid obtained by hydrolyzing palm kernel oil obtained in South America after refining and decolorizing it. Also,
Component (d), coconut oil fatty acid, is a fatty acid obtained by refining and decolorizing coconut oil obtained in the same region as component (c), and then hydrolyzing it. In the present invention
A hydrogenated version of component (c) or component (d) can also be used. When using component (c) or (d) above as component (B), the amount added is 0.1 to 3% by weight, preferably 0.3 to 1.5% by weight.
Weight%. When the amount added is less than 0.1% by weight,
The effect is not sufficient, and if the amount exceeds 3% by weight, the anticorrosion ability of the lubricating oil composition will be significantly reduced, which is not preferable. Next, component (e) is a zinc salt compound represented by the general formula below. (RCOO) ₂ Zn [] (In the formula, R represents a fatty acid having 12 to 24 carbon atoms or an oil fatty acid.) Here, examples of the oil fatty acid include coconut oil fatty acid, palm kernel oil fatty acid, lard fatty acid,
Examples include rapeseed oil fatty acids. (e) Ingredients include zinc oleate, lead stearate,
These include palm kernel oil fatty acid zinc and coconut oil fatty acid zinc. When using component (e) as component (B), the amount to be added is
It is 0.01 to 3% by weight, preferably 0.05 to 1% by weight. If it is less than 0.01% by weight, the effect will not be sufficient and 3
If it exceeds % by weight, it becomes difficult to dissolve in the lubricating oil composition, which is not preferable. Component (f) of the present invention is a mixture of fats and oils and fatty acids having 12 to 24 carbon atoms in a ratio of 5 to 95 for the former and 95 to 5 for the latter (weight ratio). Here, the fats and oils are lard,
Examples include palm oil, coconut oil, and rapeseed oil. Examples of fatty acids include lauric acid, valmitic acid, oleic acid, stearic acid, and linoleic acid. As component (f), the above mixture may be added to the base oil, or each component may be added separately to the base oil. The mixing ratio (weight) of this oil/fat and fatty acid is oil:fatty acid=5 to 95:95 to 5, preferably 10 to 95.
It should be 90:90-10. When using component (f) as component (B), the amount to be added is
It should be between 0.5 and 5% by weight, preferably between 0.8 and 3%. If the amount added is less than 0.5% by weight, there is no effect, and if it exceeds 5% by weight, oxidation stability deteriorates.
Undesirable. Component (g) of the present invention is a polyalkylene polyamine selected from the group consisting of diethylene triamine, triethylene tetraamine, tetraethylene pentamine, hexaethylene heptaamine, heptaethylene octaamine, tetrapropylene pentamine, and hexabutylene heptaamine. and a fatty acid having 12 to 30 carbon atoms or an oxidized mineral oil. In addition, fatty acids with carbon numbers of 12 to
30, preferably 16 to 20, and specific examples include behenic acid, tridecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, eicosanoic acid, and tricontanoic acid. Oxidized mineral oil is obtained by oxidizing mineral oil, for example, by blowing oxygen-containing gas into mineral oil under heating at 60 to 170°C to oxidize it, and optionally containing manganese, cobalt, nickel, etc. A catalyst of the compound can be used. 0.1 to 5 when using component (g) as component (B)
% by weight, preferably 0.3 to 1% by weight. No effect is observed when the amount added is less than 0.1% by weight, and no significant increase in effect is observed when the amount is more than 5% by weight. The lubricating oil composition of the present invention contains the above (A) and (B) in the base oil.
It is obtained by blending the components, but usually in addition to components (A) and (B), a viscosity index improver, an antioxidant, and a detergent/dispersant are added to improve the physical properties of the lubricating oil. The viscosity index improver is not particularly limited, but polymethacrylate, polybutene, etc. can be used. In particular, the molecular weight is 100,000 or less, preferably 5, which has excellent shear stability and can prevent viscosity changes for a long period of time.
Polymethacrylates of less than 10,000 are preferred. The amount added is 0.5 to 15% by weight, preferably 2 to 10% by weight.
It is. If the amount added is less than 0.5% by weight, no improvement in viscosity-temperature characteristics will be observed, and if it exceeds 15% by weight, wear resistance etc. will deteriorate due to the use of a low viscosity base oil, which is not preferable. Further, as the antioxidant, any commonly used antioxidant may be used, such as a phenol compound, an amine compound, or zinc dithiophosphate. Specifically, 2,6-di-t-butyl-4-methyl-phenol, 2,6-di-t-butyl-4-ethylphenol, 4,4'-methylenebis(2.6-di-t-
Examples include butyl-phenol, phenyl-α-naphthylamine, dialkyldiphenylamine, zinc di-2-ethylhexyldithiophosphate, zinc diamyldithiocarbamate, pinene pentasulfide, and the like. The amount added is 0.01 to 2% by weight, preferably 0.05 to 2% by weight.
It is 1% by weight. If the amount added is less than 0.01% by weight, no effect will be obtained, and even if it exceeds 2% by weight,
No significant improvement in effectiveness can be expected. Next, as the detergent and dispersant, in addition to ashless detergents, metal detergents, and the like, ashless detergent and dispersants containing boron can also be used. Specifically, alkenyl succinimides, sulfonates, finates and the like are preferred, and examples include polybutenyl succinimide, calcium sulfonate, barium sulfonate, calcium finate, barium finate, calcium salicylate and the like.
The amount added is 0.1 to 10% by weight, preferably 0.5 to 5% by weight. If the amount added is less than 0.1% by weight, the dispersibility will be insufficient, and if it exceeds 10% by weight, the friction characteristics will deteriorate, which is not preferable. In addition, corrosion inhibitors, rubber swelling agents, antifoaming agents, and the like may be added to the lubricating oil composition of the present invention, if necessary. By mixing and kneading the above raw materials, the lubricating oil composition of the present invention can be obtained. The lubricating oil composition thus obtained has good frictional properties.
That is, the static friction coefficient/dynamic friction coefficient is small. Therefore, when used in an automatic transmission or the like, the shift shock can be kept small and can be used satisfactorily even in miniaturized equipment. In addition, the frictional properties change little due to oil temperature, and the properties change less over time. This shows that the shock caused by shifting is very small and the ride is comfortable. Furthermore, it has good oxidation stability and corrosion prevention ability. Therefore, the lubricating oil composition of the present invention can be extremely effectively used as a lubricating oil for automatic transmissions, a lubricating oil for parts of tractors, etc. that have wet brakes, and the like. Furthermore, compositions having such properties are naturally effective as lubricating oils for shock absorbers, power steering systems, hydraulic suspensions, etc., and also as multi-purpose oils for these purposes. Next, the present invention will be explained in detail by examples.
In addition, the test results of the lubricating oil composition were determined by the following method. (1) SAENo.2 Friction Test Friction characteristics were evaluated under the following experimental conditions using a SAENo.2 testing machine manufactured by Greening Co., Ltd. (USA). The samples include oil as prepared and forcedly degraded oil (Lubricating oil oxidation stability test method for internal combustion engines (JISK-2514))
Two types of oils (oils that had been forcibly aged at 150°C for 24 hours) were used. Experimental conditions Disk: Paper disc for domestic automatic transmission (1 piece) Plate: Steel plate for domestic automatic transmission (2 pieces)
) Motor rotation speed: 3000 rpm Piston pressing pressure: 40 psi Oil temperature: Under conditions of 50℃ and 110℃ or higher, the dynamic friction coefficient when the rotation speed is 1200 rpm is μ1200, and the friction coefficient when stopping is μ0.
It was measured as (2) Oxidation stability Oxidation stability test of lubricating oil for internal combustion engines (JISK
-2514) at 150°C for 96 hours. (3) Corrosion test In accordance with JISK-2513, the corrosion state of the copper plate after being treated at 100°C for 3 hours was evaluated. Examples 1 to 6 and Comparative Examples 1 to 3 8.0% by weight of polymethacrylate (molecular weight 4200), 0.5% by weight of zinc di-2-ethylhexyldithiophosphate and polybutenyl succinimide (polybutenyl Base molecular weight 1000)
A predetermined amount of the compound shown in Table 1 was added to a base oil containing 4.0% by weight to obtain a lubricating oil composition. The test results are shown in Table 1. Examples 7 to 9 and Comparative Examples 4 to 6 Predetermined amounts of the compounds shown in Table 2 were added to the same base oil as in Example 1 to obtain lubricating oil compositions. The test results are shown in Table 2. Examples 10 to 12 and Comparative Examples 7 to 8 A predetermined amount of the compound shown in Table 3 was added to the same base oil as in Example 1 to obtain a lubricating oil composition. The test results are shown in Table 3. Examples 13 to 15 and Comparative Examples 9 to 13 Predetermined amounts of the compounds shown in Table 4 were added to the same base oil as in Example 1 to obtain lubricating oil compositions. The test results are shown in Table 4. Examples 16 to 18 and Comparative Examples 14 to 15 Predetermined amounts of the compounds shown in Table 5 were added to the same base oil as in Example 1 to obtain lubricating oil compositions. The test results are shown in Table 5.

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[Table] *1...Reaction product between tetraethylenepentamine and isostearic acid *2...Reaction product between tetraethylenepentamine and oxidized mineral oil

Claims (1)

[Claims] 1. In the base oil (A) a kind of phosphoric acid ester or its amine salt represented by the following general formulas [], [] and [] (In the above formulas [], [] and [],
R ¹ and R ² represent an alkyl group, phenyl group, or alkyl-substituted phenyl group having 4 to 30 carbon atoms;
R ¹ and R ² may be the same or different. ) and (B) (a) Esters of sorbitan with fatty acids having 12 to 24 carbon atoms, (b) Esters of glycerin and fatty acids having 12 to 24 carbon atoms, (c) Palm kernel oil fatty acids, (d) Coconut oil fatty acids , (e) a compound consisting of the general formula (RCOO) ₂ Zn (in the formula, R represents a fatty acid having 12 to 24 carbon atoms or a fat or oil fatty acid), (f) a compound consisting of a fat or oil and a fatty acid having 12 to 24 carbon atoms, Former 5~
95: the latter in a ratio of 95 to 5 (weight ratio) and (g) diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, hexaethyleneheptaamine, heptaethyleneoctaamine, tetrapropylenepentamine and hexabtyleneheptaamine Polyalkylene polyamine selected from the group consisting of 12 carbon atoms
A lubricating oil composition for wet clutches or wet brakes, characterized in that it contains one compound selected from the group consisting of -30 fatty acids or reaction products with oxidized mineral oil. 2. The composition according to claim 1, wherein (A) the phosphoric acid ester or its amine salt is oleyl acid phosphate and lauryl hydrogen phosphite or their amine salts. 3. The composition according to claim 1, wherein the ester (a) of sorbitan and a fatty acid having 12 to 24 carbon atoms in component (B) is sorbitan monooleate or sorbitan sesquioleate. 4. The composition according to claim 1, wherein component (B), the ester of glycerin and a fatty acid having 12 to 24 carbon atoms, is oleic acid monoglyceride. 5. The composition according to claim 1, wherein the compound (e) of component (B) having the general formula (RCOO) ₂ Zn is any one of zinc oleate, zinc stearate, and zinc coconut oil fatty acid. 6. The composition according to claim 1, wherein the mixture (f) of component (B) of oil and fat and fatty acid having 12 to 24 carbon atoms is a mixture of lard and oleic acid or a mixture of palm oil and oleic acid. . 7 The reaction product of component (B) (g) polyalkylene polyamine and fatty acid having 12 to 30 carbon atoms or oxidized mineral oil is the reaction product of tetraethylenepentamine and isostearic acid or oxidation with tetraethylenepentamine. A composition according to claim 1 which is a reaction product with mineral oil.