JPS60173097A - Lubricating oil composition - Google Patents

Abstract

PURPOSE:To provide a lubricating oil compsn. having high lubricating properties and excellent stability to oxidation and corrosion preventive effect, prepd. by adding a combination of a compd. selected from among sorbitan ester of fatty acid, coconut oil fatty acid, etc. and phosphoric ester, to a base lubricating oil. CONSTITUTION:The lubricating oil compsn. is prepd. by adding a combination of (A) one compd. selected from among sorbitan ester of fatty acid (e.g. sorbitan mono-oleate), glycerine ester of fatty acid, palm kernel oil fatty acid, coconut oil fatty acid, compd. of the formula (where R is 12-24C fatty acid, etc.) (e.g. zinc stearate), a mixt. of fatty oil and fatty acid and reaction product of polyalkylene polyamine and fatty acid or oxidized mineral oil, and (B) phosphoric ester (amine salt) (e.g. oleyl acid phosphate) to a base lubricating oil (e.g. mineral oil and synthetic oil).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lubricating oil composition, and more specifically to a lubricating oil that has good frictional properties, little change in frictional properties due to oil temperature or aging, and good oxidation stability, corrosion prevention ability, etc. Regarding the composition. 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 automatic transmissions, wet brakes for agricultural tractors, etc. are required to have good friction properties, thermal oxidation stability, corrosion resistance, rust prevention, and other properties.

Therefore, lubricating oils using friction modifiers have been proposed to improve frictional properties. However, lubricating oils using friction modifiers have insufficient frictional properties even when used as raw materials, and their frictional properties deteriorate due to changes in the oil temperature and deterioration of the oil (change over time) due to long-term use. There was a problem with this. Furthermore, there were also disadvantages in that oxidation stability decreased and corrosion prevention ability deteriorated.

Furthermore, in recent years, due to the miniaturization of automobiles and the rapid increase in the number of front-wheel drive vehicles, the main body of automatic transmissions has become smaller, and gear shifting has become more sensitive to the human body.
In order to improve ride comfort, further improvements in frictional characteristics have become necessary.

As a result of intensive research into lubricating oil compositions that meet these required characteristics, the present inventors discovered that the desired lubricating oil could be obtained by incorporating a specific combination of compounds into the base oil. The present invention was realized based on the findings.

That is, the present invention includes (A) a phosphoric acid ester or its amine salt (hereinafter referred to as component (A)) and CB in the base oil.
) (a) Sorbitan fatty acid ester (hereinafter referred to as component (a)) t (b) Glycerin fatty acid ester (
Hereinafter, it will be referred to as component (b). ), '(C) Palm kernel oil fatty acid (hereinafter referred to as (C) component), (d) Coconut oil fatty acid (hereinafter referred to as (d) component), (e) Compound consisting of general formula (ROOO) 2Zn (In the formula, R represents a fatty acid or an oil/fat fatty acid having 12 to 24 carbon atoms.)
(Hereinafter referred to as component (e)).

(f) A mixture of fats and oils and fatty acids (hereinafter referred to as component (f)) and a reaction product of polyalkylene polyamine and fatty acid or oxidized mineral oil (hereinafter referred to as component (g)).

) (hereinafter referred to as (B)
It is called an ingredient. ) is a lubricating oil composition characterized by containing.

In the present invention, the base oil is the main component of the lubricating oil composition,
There are no particular restrictions on base oils that are commonly used in lubricating oils, and synthetic oils, mineral oils, and the like can be used. The viscosity of the base oil is 1
3 to 20 cst at 00'C is preferred.

Specific examples of base oils include mineral oils such as 6o neutral oil, 100 neutral oil, 300 neutral oil, and 500 neutral oil produced by solvent refining or hydrogenation refining, and synthetic oils such as polyolefins, polyglycol esters, polyol esters, etc. Acid ester, silicone oil.

Examples include alkyldiphenyl 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. The phosphoric acid ester of component (A) is preferably represented by the following general formula.

(OIEI)2 In the above formulas [1) [11] and (III) R)
and R2 is an alkyl group or aryl group having 4 to 3 carbon atoms.

It represents an alkyl-substituted aryl group, and R2 and R may be the same or different.

Specific examples of phosphoric acid esters include butyl andophosphate, 2-ethylhexyl acladophosphate, lauryl acid phosphate, and oleyl acladophosphate.

Examples include stearyl acid phosphate, dibutylhydrogen heptosphite, dilauryl hydrogen heptosphite, dioleylhydrogen heptosphite, distearylhydrogen phosphite, and diphenylhydromonoliosphite. 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.

(4) The amount of the component added varies depending on the required characteristics of the target lubricating oil composition, the compounds used, etc., but is usually 0.01
~5i! %, preferably 0.1 to 21. (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.

A lubricating oil that, when added to the base oil in combination with component (4) above, has good initial friction properties, that is, the static friction coefficient/dynamic friction coefficient is small, and the values do not change due to fluctuations in oil temperature or oil deterioration (change over time). A composition is obtained.

Here, component (a) is a sorbitan fatty acid ester, specifically sorbitan monolaurate.

Sorbican monooleate, sorbitan monostearate, sorbitan sesquioleate, unrubitan dioleate or mixtures thereof can be used.

In addition, component 1(b) is a glycerin fatty acid ester, specifically oleic acid monoglyceride, stearic acid monoglyceride, oleic acid diglyceride, or a mixture thereof. When used as a component, the amount added is 0.05 to 5%, preferably 0.05%.
It is 1 to 3% by weight. The amount added is 0°05! At less than ffi%, no improvement effect on friction properties is observed, and at less than 5% ffi
If it is blended in excess of %, oxidation stability will deteriorate.

Ingredient (C) is palm kernel oil fatty acid, which is found in the Philippines, Indonesia, Malaya, and Africa.

It is a fatty acid obtained by hydrolyzing palm kernel oil obtained in South America after refining and decolorizing it. In addition, the coconut oil fatty acid of the component (d) is a fatty acid obtained by refining, decolorizing, and hydrolyzing coconut oil obtained in the same region as the component (c). In the present invention, component (C) or (a)
Hydrogenated components can also be used.

When using the above-mentioned (C) or (d) component as the (B) component, the amount added is O61-3! it%, preferably 0.
3~l. The amount taken is 5%. If the amount added is less than 01% by weight, the effect will not be sufficient, and if it exceeds 3% by weight,
This is undesirable because the corrosion prevention ability of the lubricating oil composition is significantly reduced. - Next, component (e) is a zinc salt compound represented by the following general formula.

(, ucoo), Zn [■) (In the formula, 几 represents a fatty acid having 12 to 24 carbon atoms or an oil or fat fatty acid.) Here, examples of the oil or fat fatty acid include a coconut oil fatty acid, a palm kernel oil fatty acid, and a lard fatty acid.

Examples include rapeseed oil fatty acids. (e) Component is 1
Specific examples include zinc oleate, zinc stearate, zinc palm kernel oil fatty acid, and zinc coconut oil fatty acid.

When using component (e) as component ω), the amount added is 0.
．． 01-3% by weight, preferably 0005-1% by weight. If the amount is less than 0.01% by animal amount, the effect will not be sufficient, and if it exceeds 3% by amount, it will be difficult to dissolve in the lubricating oil composition, which is undesirable. Component (f) of the present invention is a mixture of fats and oils and fatty acids. be. Here, the fats and oils used are lard and gum oil.

Coconut oil, rapeseed oil, etc. are also preferred.As the fatty acid, fatty acids having 12 to 24 carbon atoms are preferred, such as lauric acid, palmitic acid, and oleic acid.

Examples include stearic acid and linoleic acid.

(For the f> component, the above mixture may be added to the base oil, or each component may be added separately to the base oil.

The mixing ratio (1 ton) of this fat and oil is: fat and oil: fatty acid = 5-95: 95-5, preferably 10-90:
It should be between 90 and 10.

When component (f) is used as component (J3), the amount added should be 0.5 to 51 M%, preferably 0.8 to 3 M% by weight. If the amount added is less than 0%, s, there is no effect, and if it exceeds 5%, oxidation stability deteriorates, which is not preferable. .

Component (g) of the present invention is a reaction product of polyalkylene polyamide/and fatty acid or oxidized mineral oil.

Here, the polyalkylene polyamines include diethylenetriamine and triethylenetetraamine.

Tetraethylenepentamine, hexaether/heptaamine, heptaethyleneoctaamine, tetrapropylenepentamine, hexabutylenehebutamine, and the like can be used. In addition, as fatty acids, the number of carbon atoms is 12 to
30, preferably 16 to 20, specifically behenic acid, tridecanoic acid, lauric acid, myristic acid.

Examples include valmitic acid, stearic acid, eicotyric acid, and triacontanoic 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 manganese.

Catalysts of compounds such as cobalt and nickel can be used.

■) When using component (g) as the component, 0.1 to 5
% 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 5@% by weight.
No significant increase in effectiveness was observed even when the temperature exceeded ℃.

The lubricating oil composition of the present invention includes the above (4) and (B) in the base oil.
Although it is obtained by blending the components, in addition to components (4) and (B), a viscosity index improver, an antioxidant, and a detergent/dispersant are usually 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. Particularly suitable are polymethacrylates with a published rating of 100,000 or less, preferably 50,000 or less, which have good shear stability and can prevent viscosity changes for a long period of time.

The amount added is 95 to 15% by weight of O, preferably 2 to 10% by weight. 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,
Since a base oil of low viscosity is used, wear resistance etc. deteriorate, which is undesirable.

Phenolic compounds are also used as antioxidants.

Any commonly used amine compounds, dithiophosphate zinc, etc. may be used. Specifically, 2.6-Gt
-butyl-4-methyl-phenol, 2+6-di-t-
7'thyl-4-ethylphenol, 4.4'-metele/
bis(2,6-di-t-butyl-phenol, phenyl-α-7-teramine 1-dialkyldiphenylamine,
Examples include zinc di-2-ethylhexyl dithiophosphate, zinc diamyldithiocarbamate, and pinene pentasulfide. The amount added is o, o i ~ 2% by weight, preferably 0905
~1 weight J1%. If the amount added is less than 0.01% by weight, no effect will be obtained, and if it exceeds 2% by weight, no significant improvement in the first effect 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, etc. are preferred, such as polybutenyl succinimide.

Calcium sulfonate, barium sulfonate.

Examples include calcium finate, barium finate, and calcum salicylate. The amount added is 0.1-1
0% by weight, preferably 0.5-5% by weight. If the amount added is less than 0.1%, the dispersibility is insufficient, and 10f
If the amount exceeds i%, the friction characteristics will deteriorate, which is not preferable.

Corrosion inhibitors, rubber swelling agents, antifoaming agents, and the like can be added to the lubricating oil composition of the invention, if necessary.

The lubricating oil composition of the present invention can be obtained by mixing and kneading the above raw materials. The lubricating oil composition thus obtained has good frictional properties, that is, a small coefficient of static friction/coefficient of kinetic friction.

Therefore, when used in an automatic transmission or the like, shift shock can be suppressed to a small level, and it can be used satisfactorily even in miniaturized equipment.

Moreover, the change in frictional properties due to oil temperature is small, and the changes in these properties over time are also small. This shows that the jitter 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 used extremely effectively as a lubricating oil for automatic transmissions, a lubricating oil for parts with wet brakes such as tractors, etc. Furthermore, a composition having such characteristics can be used very effectively. Naturally, it is also effective as a lubricant for shock amplifiers, power steering, hydraulic suspensions, etc., and as a lubricant for these multiple purposes.

Next, the present invention will be explained in detail by examples.

The test results for the lubricating oil composition were determined by the following method.

(1) SAE A2 Friction Test Friction characteristics were evaluated using an SAE A2 tester manufactured by Greening Co., Ltd. (USA) under the following experimental conditions.

The samples used were the oil at the time of preparation and the forcedly degraded oil (150℃ according to the lubricating oil oxidation stability test method for internal combustion engines (-2514 to JI8).
Two types of oils (oils that had been forcibly aged for 24 hours) were used.

Experimental conditions Disc: 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: jOpsi Oil temperature: 50°C and 110°C or higher The dynamic friction coefficient at a rotational speed of 120 rpm was measured as μm200, and the friction coefficient when stopped was μ0.

(2) Oxidation stability test of lubricating oil for internal combustion engines (JISK-25
14) under the conditions of 150°C and 96 hours.

(3) Corrosion Test Based on 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 Polymethacrylate (molecular weight 4200) 8.0% by weight, zinc di-2-ethylhexyldithiophosphate 0.5% 11% in mineral oil at 5°3 cst at 100°C and polybutenyl succinimide (polybutenyl group molecule! 1
A lubricating oil composition was obtained by adding a predetermined amount of the compound shown in Table 1 to the base oil to which 4.0% of the amount was added. 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 A predetermined amount of the compound shown in Table 4 was added to the same base oil as in Example 1 to obtain a lubricating oil composition. The test results are shown in Table 4.

Examples 16 to 18 and Comparative Examples 14 to 15 A predetermined amount of the compound shown in Table 5 was added to the same base oil as in Example 1 to obtain a lubricating oil composition. The test results are shown in Table 5.

Continuing from page 1 ■Int, C1,' Identification code Office serial number 40:0
8

Claims (1)

[Claims] 1) A base oil containing (A) a phosphoric acid ester or an amine salt thereof and (B) (a) a sorbitan fatty acid ester, (b)
) glycerin fatty acid ester, (C) palm kernel oil fatty acid, (d) coconut oil fatty acid, (e) general formula (ROOO) t
A compound consisting of Zn (in the formula, 2 represents a fatty acid or an oil/fat fatty acid having 12 to 24 carbon atoms.> t (f) a mixture of an oil/fat and a fatty acid; and <g) a reaction product of a polyalkylene polyamine and a fatty acid or an oxidized mineral oil. A lubricating oil composition characterized by containing one type of compound selected from the group consisting of: 2) The composition according to claim 1, wherein (A) the phosphoric acid ester or its amine salt is oleyl abradophosphate and lauryl hydrogen phosphite or their amine salts. 5) The composition according to claim 1, wherein the sorbitan fatty acid ester (a) of component (B) is sorbitan monooleate or sorbitan sesquioleate. 4), Component (b) glycerin fatty acid ester is
Claim 1 which is oleic acid monoglyceride
Compositions as described in Section. 5), CB) component (e) general formula (ROOO), Z
2. The composition according to claim 1, wherein the compound consisting of n is any one of zinc oleate, zinc stearate, and zinc coconut oil fatty acid. 6), (B) component (f) mixture of oil and fat and fatty acid is a mixture of lard and oleic acid or palm oil and oleic acid/
The composition according to claim 1, which is a mixture of e. 7) The reaction product of component (g) polyalkylene polyamine and fatty acid or oxidized mineral oil is the reaction product of tetraethylenepentamine and isostearic acid or the reaction product of tetraethylenepentamine and oxidized mineral oil. The composition according to claim 1.