JP2966975B2 - Lubricating oil composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition and, more particularly, to a base oil containing an ester compound as a main component and a specific phosphorus compound and an amine compound, and to provide abrasion resistance and hydrolysis resistance. The present invention relates to a lubricating oil composition having excellent properties.

[0002]

2. Description of the Related Art
The lubricating oils include mineral lubricating oils composed of mineral oils, chemically synthesized synthetic lubricating oils, fatty lubricating oils composed of animal and vegetable fats and oils, mixed lubricating oils obtained by mixing mineral oils with animal and vegetable fats, and mineral oils and synthetic oils. Various types such as mixed lubricating oils are used. Among these, the use of synthetic lubricating oils that can be chemically modified and synthesized in various ways is increasing.
Ester lubricating oils are widespread. However,
Ester-based lubricating oils have poor abrasion resistance when used alone, and even when used in a compressor for a refrigerator, there is a remarkable drawback in that a sliding member is significantly worn. As an anti-wear agent to prevent it, usually tricresyl phosphate (TCP)
And triphenyl phosphite (TPP) are used, but their abrasion preventing effect is not as high as expected. Esters are susceptible to hydrolysis in the presence of water, and have the drawback that fatty acids and fatty acid metal salts are formed, causing corrosion in the system and clogging of capillaries.

[0003]

Means for Solving the Problems Accordingly, the present inventors have:
In view of the above-mentioned situation, intensive studies have been made on a base oil containing an ester-based compound as a main component in order to obtain a more excellent lubricating oil. As a result, they have found that the above object can be achieved by blending a specific phosphorus compound and an amine compound. The present invention has been completed based on such findings.

That is, the present invention relates to (A) a base oil containing an ester compound as a main component, (B) a general formula (I) or (II)
Or (III)

[0005]

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[0006]

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[0007]

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[Wherein, R¹And R^TwoEach have 3 carbon atoms
An alkyl group having from 30 to 30, an aryl group having from 6 to 30 carbon atoms, or
A cycloalkyl group having 3 to 30 carbon atoms;^Three, R^Four
And R ^FiveAre hydrogen and alkyl having 3 to 30 carbon atoms, respectively.
Group, an aryl group having 6 to 30 carbon atoms or an aryl group having 3 to 30 carbon atoms
R represents a cycloalkyl group;⁶, R⁷And R⁸Each
Represents an alkylene group having 2 to 4 carbon atoms, and p, q and r are
Each represents 0 to 20;⁹, R^Ten, R¹²And R¹³Is
Each of hydrogen, an alkyl group having 3 to 30 carbon atoms, and 6 carbon atoms
To 30 aryl groups or cycloalkyl having 3 to 30 carbon atoms
And R represents¹¹Represents an alkylene group having 2 to 4 carbon atoms
And x represents 1 to 20. ] Of the phosphorus compound represented by
At least one and (C) a general formula (IV)

[0009]

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[In the formula, R ¹⁴ , R ¹⁵ and R ¹⁶ represent hydrogen, an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a cycloalkyl group having 3 to 30 carbon atoms. However,
At least one of R ¹⁴ , R ¹⁵ and R ¹⁶ is a group other than hydrogen, and has a total carbon number of 6 or more in one molecule. And an amine compound represented by the formula:

First, in the present invention, the ester compound which is a main component of the base oil (A) is a mono- or polyhydric fatty acid ester. The kinematic viscosity is not particularly limited, but is usually 1 to 500 cSt (40 ° C.), preferably 10 to 100 cSt (40 ° C.). Kinematic viscosity is 1 cSt
If the temperature is lower than (40 ° C.), the lubricating property becomes insufficient, causing abnormal wear and seizure, which is not preferable. Also, 500cSt (40 ℃)
Exceeding the range will result in poor oil return at low temperature, resulting in insufficient refueling and burning. Specific examples having these characteristics include trimethylolpropane tri-2-ethylhexanoate, pentaerythritol tetra-2-ethylhexanoate, dioctyl adipate and the like.

Next, the phosphorus compound (B) blended in the base oil (A) containing an ester compound as a main component is represented by the aforementioned general formula (I), (II) or (III). There are things. These phosphorus compounds are used alone or in combination of two or more. The mixing ratio of the phosphorus compound as the component (B) is not particularly limited and may be appropriately selected depending on the circumstances. Usually, the mixing ratio of the base oil (A) containing the ester compound as a main component is 0%. 0.001 to 10% by weight
And preferably 0.01 to 2% by weight. The blending amount is 0.
If the amount is less than 001% by weight, the effect of preventing abrasion is insufficient, which is not preferable. On the other hand, if it exceeds 10% by weight, the effect of preventing abrasion reaches the saturation point and an effect commensurate with the compounding amount cannot be obtained.

In the above general formulas (I), (II) and (III), each symbol is as described above. That is, R ¹
And R ² are each an alkyl group having 3 to 30 carbon atoms, preferably an alkyl group having 6 to 20 carbon atoms (eg, hexyl group, octyl group, decyl group, lauryl group, stearyl group, oleyl group, etc.), An aryl group having 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms (for example, phenyl group, tolyl group, xylyl group, nonylphenyl group, dodecylphenyl group, etc.) or a cycloalkyl group having 3 to 30 carbon atoms, preferably 5 to 15 cycloalkyl groups (for example, cyclopentyl group, cyclohexyl group, trimethylcyclohexyl group, etc.), and R ³ , R ⁴ , R ⁵ ,
R ⁹ , R ¹⁰ , R ¹² and R ¹³ each represent hydrogen, carbon number 3 to
An alkyl group having 30 carbon atoms, preferably an alkyl group having 6 to 20 carbon atoms (for example, hexyl group, octyl group, decyl group, lauryl group, stearyl group, oleyl group, etc.);
An aryl group having 0 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms (e.g., phenyl, tolyl, xylyl, nonylphenyl, etc.) or a cycloalkyl group having 3 to 30 carbon atoms, preferably having 5 to 15 carbon atoms. And a cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group, a trimethylcyclopentyl group, etc.). R ⁶ , R ⁷ , R ⁸
And R ¹¹ each represent an alkylene group having 2 to 4 carbon atoms (eg, an ethylene, propylene group, and butylene group). Here, p, q and r each represent 0 to 20 (including real numbers, not limited to integers), preferably 2 to 10, and x represents 1 to 2
0 (including real numbers, not limited to integers), preferably 1 to 10
Is shown. Specific examples of the phosphorus compound represented by the general formula (I) include dilauryl hydrogen phosphite,
Examples thereof include dioleyl hydrogen phosphite and diphenyl hydrogen phosphite. Specific examples of the phosphorus compound represented by the general formula (II) include tris polyoxyethylene decyl ether phosphate and dipolyoxyethylene nonyl phenyl ether phosphate. Specific examples of the phosphorus compound represented by the general formula (III) include tetraphenyl dipropylene glycol diphosphite, tetratridecyl diethylene glycol diphosphite, and the like.

Further, a group containing an ester compound as a main component
The amine compound (C) to be blended with the oil (A) is the above-mentioned general compound.
This is represented by the formula (IV). Where R¹⁴, R^FifteenPassing
And R ¹⁶Is hydrogen, an alkyl group having 3 to 30 carbon atoms,
An aryl group having 6 to 30 carbon atoms or a cycle having 3 to 30 carbon atoms
Loalkyl group, preferably alkyl having 6 to 24 carbon atoms
Group, aryl group and cycloalkyl group. Where R
¹⁴, R^FifteenAnd R¹⁶At least one is a group other than hydrogen
And the total number of carbon atoms in one molecule must be 6 or more.
It is important. Here, the alkyl group may be straight-chain, branched, or saturated.
Or it may be unsaturated. However, dissolution in base oil
From the viewpoint of stability, a branched or unsaturated alkyl group is preferred. This
The amount of the amine compound (C) is particularly limited.
No, but usually base oils based on ester compounds
0.001 to 10% by weight based on (A), preferably
Is 0.01 to 2% by weight. The amount is 0.001 weight
%, The effect of preventing hydrolysis is insufficient, which is preferable.
Absent. On the other hand, if it exceeds 10% by weight, the effect of preventing hydrolysis is
When the saturation point is reached, an effect commensurate with the compounding amount can be obtained.
Absent. In addition, it has a negative effect on wear prevention and thermal stability.
Is not preferred. Specific examples of such an amine compound (C)
For example, tri (2-ethylhexyl) amine, di
(2-ethylhexyl) amine, tert-dodecyl ami
Tert-octadecylamine, tert-behenylamine
, Oleylamine, dioleylamine, isostearyl
Luamine, dimethyl oleyl amine, dodecylanili
, Dibenzylamine, cyclohexylamine, 2-meth
Tylcyclohexylamine, cyclohexyldecyl
Min and the like can be mentioned.

The lubricating oil composition of the present invention can of course also be used as a refrigerating machine oil using various refrigerants (such as a chlorofluorocarbon-based refrigerant and an alternative chlorofluorocarbon-based refrigerant) or as a hydraulic oil for hydraulic equipment. And, if necessary, an antioxidant, an oil agent, a copper deactivator, an antifoaming agent and the like can be optionally blended.

[0016]

The present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1 to 6 and Comparative Examples 1 to 8 The lubricating oil compositions were obtained by using the base oils shown in Table 1 at the compounding ratios shown in Table 2 to obtain a lubricating oil composition. Was subjected to the following test. In the abrasion test, the wear amount of the pin was evaluated by a Falex tester under the following conditions. In addition, the hydrolysis test was performed under the following conditions under ASTM D-
According to the hydrolysis test method of 2619-88, the total acid value of the oil layer after the test was measured. Further, a shield tube test was performed under the following conditions. Abrasion test conditions Injection of Freon 134a 10 liter / hour Load 300 LBS, time 60 minutes Test piece material Pin SAE3135 (AST
MD 2670-81 standard material) Block AISI 1137 (ASTM D 267
0-81 standard material) Under air atmosphere Load 300LBS, Time 60min Test piece material Pin SAE3135 (AST
MD 2670-81 standard material) Block AISI 1137 (ASTM D 267
0-81 standard material) Hydrolysis test conditions Temperature 93 ° C, time 240 hours Catalyst Copper piece (13 × 51 × 1mm) Oil 75g, water 25g Shield tube test conditions Temperature 175 ° C, time 720 hours, refrigerant Freon 134a

[0017]

[Table 1]

[0018]

[Table 2]

Further, the results of each of the test items performed are described in the third section.
It is shown in the table.

[0020]

[Table 3]

As can be seen from the test results in Table 3, according to the present invention, the shield tube test was satisfactory without any problem.
In addition, it can be seen that the amount of abrasion is small and the total acid value after hydrolysis is excellent without increasing. On the other hand, in the comparative example,
Although the tube test was satisfactory without any problem, it can be seen that each of them lacks either abrasion resistance or hydrolysis resistance.

【The invention's effect】

As described above, according to the present invention, the shield tube test is satisfactory without any problem, and the abrasion resistance and hydrolytic resistance under a chlorofluorocarbon atmosphere are extremely excellent. The effect exerted when used as oil can be sufficiently expected, and the effect of use is extremely large. Furthermore, the lubricating oil composition of the present invention has excellent abrasion resistance and excellent hydrolysis resistance even in an air atmosphere, and has an extremely large action and effect as other lubricating oils such as hydraulic oils.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification symbol FI C10M 137: 02) C10N 30:06 40:30 (58) Investigated field (Int.Cl. ⁶ , DB name) C10M 105/32 -105/48 C10M 137/02-137/08 C10M 133/04-133/14 C10M 133/54

Claims (2)

(57) [Claims] (A) Trimethylolpropane tri2-
Ethyl hexanoate, pentaerythritol tetra 2
Base oil containing as a main component at least one ester compound selected from ethylhexanoate, trimethylolpropanetricaplate, pentaerythritol tetracaprate and dioctyladipate; (B) general formulas (I) and (II) Or (III) [Wherein, R ¹ and R ² each represent an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or 3 to 3 carbon atoms.
R ³ , R ⁴ and R ⁵ each represent hydrogen, an alkyl group having 3 to 30 carbon atoms, and a cycloalkyl group having 6 to 6 carbon atoms;
An aryl group having 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms, wherein R ⁶ , R ⁷ and R ⁸ each have 2 to 4 carbon atoms;
And p, q and r are each 0 to 2
0, R ⁹ , R ¹⁰ , R ¹² and R ¹³ are each hydrogen,
R 3 represents an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms;
¹¹ represents an alkylene group having 2 to 4 carbon atoms, x represents 1 to 20
Is shown. At least one phosphorus compound represented by the general formula (IV): [Wherein, R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen, an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms or 3 carbon atoms.
And represents up to 30 cycloalkyl groups. Provided that at least one of R ¹⁴ , R ¹⁵ and R ¹⁶ is a group other than hydrogen;
The total number of carbon atoms in the molecule is 6 or more. ] A lubricating oil composition comprising an amine compound represented by the formula: (A) a base oil mainly composed of an ester compound, (B) a general formula (I), (II) or (III) [Wherein, R ¹ and R ² each represent an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or 3 to 3 carbon atoms.
R ³ , R ⁴ and R ⁵ each represent hydrogen, an alkyl group having 3 to 30 carbon atoms, and a cycloalkyl group having 6 to 6 carbon atoms;
An aryl group having 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms, wherein R ⁶ , R ⁷ and R ⁸ each have 2 to 4 carbon atoms;
And p, q and r are each 0 to 2
0, R ⁹ , R ¹⁰ , R ¹² and R ¹³ are each hydrogen,
R 3 represents an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms;
¹¹ represents an alkylene group having 2 to 4 carbon atoms, x represents 1 to 20
Is shown. And at least one phosphorus compound represented by the general formula (IV): [Wherein, R ¹⁴ , R ¹⁵ and R ¹⁶ are hydrogen, an alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms or 3 carbon atoms.
And represents up to 30 cycloalkyl groups. Provided that at least one of R ¹⁴ , R ¹⁵ and R ¹⁶ is a group other than hydrogen;
The total number of carbon atoms in the molecule is 6 or more. ] A refrigerating machine oil comprising an amine compound represented by the formula: