JPH10279982A - Lubricating oil composition - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Lubricity, cleanliness, electrical insulation, hydrofluorocarbon (HFC, Hydro Fluoro C)
compatibility with H. arbon) and hydrochlorofluorocarbon (HCFC, Hydro Chloro F)
The present invention provides a lubricating oil composition which is excellent in compatibility with FluoroCarbon and has excellent copper plating suppressing effect and oxidation stability. SOLUTION: (i) a carbonate oil represented by the following general formula [I], and (ii) at least one kind selected from an epoxy group-containing compound, a phenolic antioxidant compound and a phosphate ester extreme pressure agent. A lubricating oil composition comprising a compound; R ¹ OCOOR ²
... [I] (wherein, R ¹ and R ² each independently represent a hydrocarbon group having 30 or less carbon atoms or a hydrocarbon group having 2 or less carbon atoms)
It is a hydrocarbon group having up to 30 ether bonds. )

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, it can be used for lubricating oils for refrigerators in which the requirements for lubricity and detergency have been stricter than before, and have a lubricity, detergency and Lubricating oil excellent in electrical insulation, especially hydrofluorocarbon (HFC, HydroFluoro Ca)
rbon), hydrochlorofluorocarbon (HCF)
C, Hydro Chloro Fluoro Car
bon) or a mixture thereof as a refrigerant.

[0002]

BACKGROUND OF THE INVENTION In lubricating oils for refrigerators, the refrigerant gas has been changed to non-destructive ozone layer R-134a (CH ₂ F-CF ₃ ), and has been conventionally used as lubricating oils for refrigerators. Mineral oils and alkylbenzene compounds that have been used cannot be used because they have no compatibility with refrigerant gas. Currently, glycol ether lubricating oils have been developed as lubricating oils for the refrigerant gas refrigerators.

[0003] For example, US Pat. No. 4,755,316 discloses that tetrafluoroethane has a molecular weight of 300 to 200.
0 and a polyoxyalkylene glycol having a kinematic viscosity at 37 ° C. of about 25 to 150 cSt is disclosed.

[0004] However, it has been pointed out that such glycol ether-based lubricating oils generally have insufficient heat stability, have a high hygroscopicity, and further increase the hardness by shrinking rubber seal materials such as NBR. .

Further, carboxylic acid ester type lubricating oils recently called polyol ester and hindered ester have been used in hydrofluorocarbons (H
FC (Hydro Fluoro Carbon) has been developed as a lubricating oil for refrigerators using refrigerant. However, these lubricating oils generate carboxylic acid by hydrolysis or thermal decomposition, so that copper pipes and the like are corroded, and copper plating occurs on sliding portions of the compressor. For this reason, reduction in the reliability of the compressor has been cited as a problem. Further, in these lubricating oils, there is also a problem that oxidation progresses by heating, and the hue of the lubricating oil deteriorates.

The non-destructive hydrofluorocarbon (HFC, HydroFluoro Car)
specific examples of R-134a and R-40a of R-152a and mixtures thereof,
7C, R-410C, R-410A, R-410B, R
-404A and the like. In addition, hydrochlorofluorocarbon (HCFC, Hy
dro Chloro Fluoro Carbon)
Is also used as a refrigerant. Examples of such hydrochlorofluorocarbons include R-22, R-123, and R-22.
-124 and the like. These hydrochlorofluorocarbons may be used alone or as described above (HFC, Hydro Fluor).
o Carbon).

The present inventors have proposed lubricating properties, cleanliness properties, electrical insulation properties, and hydrofluorocarbons (HFC, Hydro
Compatibility with Fluoro Carbon, and hydrochlorofluorocarbon (HCFC, Hydro)
After extensive research to obtain a lubricating oil composition having excellent compatibility with Chloro FluoroCarbon), copper plating suppressing effect and oxidation stability,
When a specific carbonate oil is used as a base oil and blended with at least one compound selected from the group consisting of an epoxy group-containing compound, a phenolic antioxidant compound and a phosphate ester extreme pressure agent, lubrication excellent in the above properties is obtained. The inventors have found that oil can be obtained, and have completed the present invention.

[0008]

An object of the present invention is to solve the problems associated with the prior art as described above, and to provide a lubricating property, a cleaning property, an electric insulating property, a hydrofluorocarbon (HFC,
Compatibility with Hydro Fluoro Carbon and hydrochlorofluorocarbon (HCF)
C, Hydro Chloro Fluoro Car
It is an object of the present invention to provide a lubricating oil composition which is excellent in compatibility with B.B.) and excellent in copper plating suppression effect and oxidation stability.

More specifically, the present invention relates to a hydrofluorocarbon (HFC, Hyd
It is an object of the present invention to provide a lubricating oil composition that can be particularly preferably used as a lubricating oil for a refrigerator such as a room air conditioner that uses (ro Fluoro Carbon) as a refrigerant.

[0010]

SUMMARY OF THE INVENTION A lubricating oil composition according to the present invention comprises (i) a carbonate oil represented by the following general formula [I], (ii) an epoxy group-containing compound, a phenolic antioxidant compound and a phosphate ester. And at least one compound selected from the group consisting of system extreme pressure agents.

R ¹ OCOOR ² ... [I] (In the formula [I], R ¹ and R ² each independently represent a hydrocarbon group having 1 to 30 carbon atoms or 2 to 30 carbon atoms.
Is a hydrocarbon group having an ether bond. ) The lubricating oil composition comprises (ii) an epoxy group-containing compound, a phenolic antioxidant compound, and a phosphate ester extreme pressure agent per 100 parts by weight of the carbonate oil represented by the formula [I]. It is preferable that the content of at least one compound selected from the group consisting of is 0.01 to 5 parts by weight.

The lubricating oil composition according to the present invention is excellent in lubricity, cleanliness and electrical insulation, and is easy to lower the viscosity at low temperatures. Gear oil, room air conditioners, car coolers, lubricating oils for refrigerators such as electric refrigerators, textile lubricating oils, rolling lubricating oils, and the like.

Further, the lubricating oil composition according to the present invention not only has excellent properties as described above, but also has a non-destructive hydrofluorocarbon (HFC, Hydro Fl).
It is excellent in compatibility with Uro Carbon and can be used as lubricating oil for refrigerators using these hydrogenated products as refrigerants.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the lubricating oil composition according to the present invention will be specifically described. The novel lubricating oil according to the present invention comprises (i) a carbonate oil and at least one compound selected from the group consisting of an epoxy group-containing compound, a phenolic antioxidant compound and a phosphate ester extreme pressure agent. Have been.

In the present invention, a carbonate oil represented by the following general formula [I] is used as a lubricating oil base oil. R ¹ OCOOR ² ... [I] In the above formula [I], R ¹ and R ² are each independently a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon having an ether bond having 2 to 30 carbon atoms. Group.

Specific examples of the above R ¹ and R ² include:
Methyl group, ethyl group, n-propyl group, isopropyl group,
n-butyl group, isobutyl group, s-butyl group, t-butyl group,
Pentyl group, isopentyl group, neopentyl group, n-hexyl group, 1,3-dimethylbutyl group, 2,3-dimethylbutyl group, isohexyl group, n-heptyl group, isoheptyl group,
3-methylhexyl, n-octyl, 2-ethylhexyl, isooctyl, n-nonyl, isononyl, n-decyl, isodecyl, n-undecyl, isoundecyl, n-dodecyl, isododecyl , N-tridecyl group, isotridecyl group, n-tetradecyl group, isotetradecyl group, n-pentadecyl group, isopentadecyl group, n-
Hexadecyl group, isohexadecyl group, n-heptadecyl group, isoheptadecyl group, n-octadecyl group, isooctadecyl group, n-nonadecyl group, isononadecyl group, n-icosyl group, isoicosyl group, 2-ethylhexyl group,
Aliphatic hydrocarbon groups such as 2- (4-methylpentyl) group; alicyclic hydrocarbon groups such as cyclohexyl group, 1-cyclohexenyl group, methylcyclohexyl group, dimethylcyclohexyl group, decahydronaphthyl group, and tricyclodecanyl group Hydrogen group; phenyl group, p-isopropylphenyl group, pt-butylphenyl group, p-isoamylphenyl group, p-octylphenyl group, p-nonylphenyl group, o-tolyl group, p-tolyl group, m-tolyl group , A 2,4-xylyl group, a mesityl group, an aromatic hydrocarbon group such as a 1-naphthyl group; a benzyl group, a methylbenzyl group, a β-phenylethyl group (phenethyl group),
Phenylethyl group, 1-methyl-1-phenylethyl group, p-
Aromatic aliphatic hydrocarbon groups such as methylbenzyl group, styryl group and cinnamyl group; and hydrocarbon groups having an ether bond represented by the following general formula [Ia].

− (R¹¹-O)_q-R¹² ... [Ia] In the general formula [Ia], R¹¹Represents 2 to 6 carbon atoms
Alkylene group or arylene having 6 to 28 carbon atoms
Group, specifically, ethylene group, propylene group,
Trimethylene group, 2,2-dimethylpropylene group, 2-butyl
2-ethylpropylene group, phenylene group, naphthylene group
Is mentioned. Also, R¹²Is an oil having 28 or less carbon atoms.
Aliphatic, alicyclic and aromatic hydrocarbon groups,
Has R ¹And R^TwoSimilar to the groups listed as specific examples of
Aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon
And araliphatic hydrocarbon groups. And q is
It is an integer of 1 to 20. Represented by such a general formula [Ia]
As a hydrocarbon group having an ether bond to be
Thixethyl group, 2-n-butoxyethyl group, 2-t-butoxy
Ethyl group, 3-methoxy-2,2-dimethylpropyl group, 3-E
Toxi-2,2-dimethylpropyl group, 3-t-butoxy-2,2-di
Methylpropyl group, 3-methoxy-2-ethyl-2-butylpro
Pill group, 3-ethoxy-2-ethyl-2-butylpropyl group, 3-
t-butoxy-2-ethyl-2-butylpropyl group, 2-phenoxy
Siethyl group, 2-p-isopropylphenoxyethyl group, 2-
p-t-butylphenoxyethyl group, 2-p-isoamylpheno
Xyethyl group, 2-p-octylphenoxyethyl group, etc.
No.

Of these R ¹ and R ² , a methyl group,
Butyl group, 2-ethylhexyl group, 3,5,5-trimethylhexyl group, phenyl group, p-isopropyl group, pt-butylphenyl group, p-octylphenyl group and the general formula [I
The hydrocarbon group having an ether bond represented by a] is preferred.

In the present invention, the above-mentioned carbonate oils may be used alone, or a plurality of carbonate oils may be mixed and used. Lubricating oil according to the present invention,
(i) Carbonate oil 10 represented by the above general formula [I]
It contains at least one compound selected from the group consisting of an epoxy group-containing compound, a phenolic antioxidant compound, and a phosphate ester extreme pressure agent with respect to 0 parts by weight.

The epoxy group-containing compound is preferably a glycidyl ether compound represented by the following formulas [1] to [3] or a compound containing an epoxycyclohexyl group.

[0021]

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(In the formula, R ⁴ is a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having an ether bond having 2 to 50 carbon atoms.)

[0023]

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(In the formula, R ⁵ is a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having 2 to 50 carbon atoms and having an ether bond.)

[0025]

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(Wherein, R ⁶ is a hydrocarbon group having 2 to 30 carbon atoms or a hydrocarbon group having an ether bond having 2 to 50 carbon atoms.) As such a glycidyl ether compound, phenyl is used. Glycidyl ether, 3- (2-xeniloxy) -1,2-epoxypropane, 3- (p-sec-butylphenyl) -1,2-epoxypropane,

[0027]

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And the like. As the compound containing an epoxycyclohexyl group,

[0029]

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And the like. In the present invention, the epoxy group-containing compound is preferably used in a proportion of 0.01 to 5 parts by weight, preferably 0.1 to 1.0 part by weight, based on 100 parts by weight of the carbonate oil.

As the phenolic antioxidant, a phenolic compound represented by the following general formula [4] is preferable.

[0032]

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Wherein R ⁷ is an alkyl group having 1 to 4 carbon atoms, 1 is an integer of 1 to 3, m and n are integers of 0 to 3, and satisfies the relationship of 1 ≦ l + m + n ≦ 6. As such a phenolic antioxidant compound, specifically,

[0034]

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And the like. In the present invention, the phenolic antioxidant compound is used in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the carbonate oil.
It is preferably used in a proportion of 0.5 parts by weight.

The phosphoric acid ester extreme pressure agent is preferably composed of a phosphoric acid ester compound represented by the following general formula [5].

[0037]

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(Wherein R ⁸ , R ⁹ and R ¹⁰ may be the same or different and each represents a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having an ether bond having 2 to 30 carbon atoms) Specific examples of such a phosphate-based extreme pressure agent include:

[0039]

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And the like. In the present invention, the phosphate ester extreme pressure agent is preferably used in a proportion of 0.01 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the carbonate oil.

The lubricating oil composition according to the present invention may contain at least one compound selected from the group consisting of the glycidyl compounds, phenolic antioxidants and phosphate extreme pressure agents as described above. It is sufficient that a plurality of compounds can be used in combination.

The lubricating oil composition according to the present invention may contain other components in addition to the above-described carbonate oil, glycidyl compound, phenolic antioxidant, and phosphate ester extreme pressure agent. .

For example, when the lubricating oil composition according to the present invention is used as an industrial gear oil, an engine oil for an automobile, or a gear oil for an automobile, neutral oil, bright stock and the like are compounded as the other components described above. You may. Also, carboxylic acids such as α-olefin oligomers such as liquid polybutene and liquid decene oligomers, diisooctyl adipate, diisooctyl sebacate, dilauryl sebacate, 2-ethylhexanoic acid tetraester of pentaerythritol, and hexanoic acid triester of trimethylolpropane Esters and vegetable oils may be blended in the lubricating oil. Further, in the present invention, known lubricating oil additives such as cleaning dispersants, antioxidants, and load-bearing additives described in, for example, "Petroleum Product Additives" edited by Toshio Sakurai (published by Koshobo, 1974). Lubricating oil additives such as oily agents, pour point depressants, and antifoaming agents can be included in the lubricating oil composition within a range that does not impair the purpose of the present invention.

When the lubricating oil composition according to the present invention is used as a lubricating oil for refrigerators, particularly, a hydrofluorocarbon (HFC, Hydro F) such as R-134a is used.
In a refrigerator using Fluorocarbon as a refrigerant gas, glycol ethers or carboxylic esters are used as the other components from the viewpoint of compatibility. However, the added amount of these components depends on heat resistance,
In order to deteriorate the compatibility with R-134a and the water absorption, the amount of addition is preferably less than 60% by weight based on 100% by weight of the total amount of the lubricating oil. Further, a known lubricant additive as described above may be blended in the lubricant. Furthermore, non-depleting hydrofluorocarbons (HFC, Hyd, etc.) such as R-134a are contained in lubricating oil for refrigerators.
ro Fluoro Carbon) or R-22
Hydrochlorofluorocarbon (HCFC, Hydro Chloro Flu)
oro Carbon), and also these hydrogenated products.

When the lubricating oil according to the present invention is used for applications such as lubricating oil for rolling, metal working oil, lubricating oil for textiles, etc., an appropriate emulsifier may be used as conventionally practiced. It is also possible to use the above carbonate oil as an emulsion with water.

[0046]

The lubricating oil composition according to the present invention has lubricity,
It has excellent cleanliness and electrical insulation properties, and also has the effect of easily lowering the viscosity at low temperatures.

Accordingly, the lubricating oil composition according to the present invention can be used for industrial gear oils, automotive engine oils, automotive gear oils, lubricating oils for refrigerators such as room air conditioners, car air conditioners and electric refrigerators, and lubricating oils for textiles. It can be widely used for applications such as lubricating oil for rolling.

Further, the lubricating oil composition according to the present invention is hardly oxidized, and when used as a lubricating oil for a refrigerator, can suppress copper plating of the sliding machine and has high lubricity. Can maintain long-term stability.

[0049]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

The analysis of the carbonate oil and the control product and the performance evaluation of the lubricating oil in the examples and comparative examples are conducted according to the following test methods. [Test method] a. Kinematic viscosity JIS K-2283 b. Viscosity index JIS K-2283 c. Copper plating suppression test 10 g of a sample (lubricating oil composition) was collected in a 20 ml glass bottle, and (size 1) (0.6 × 30 mm) iron and copper pieces, and 0.1N HCl in isopropanol was added.
2 ml was added, and the mixture was heated in an oven at 50 ° C. for 12 hours in a sealed state. After the heating, the degree of adhesion of copper to the surface of the iron piece (so-called copper plating phenomenon) was visually observed and evaluated according to the following criteria.

×: Copper plating progressed △: Copper plating progressed slightly ○: Copper plating progressed slightly ◎: No copper plating was observed d. Oxidation stability In a 50 ml glass bottle A sample (lubricating oil composition) (20 g) was sampled and heated in an oven at 150 ° C. for 12 hours under air.
After heating, the hue of the oil was evaluated in comparison with the ASTM standard color.
In addition, the total acid value (mgKOH / g) of the lubricating oil composition was determined according to JIS K2501.
It measured according to.

E. Lubricity Using a high-pressure atmosphere friction tester (manufactured by Shinko Zoki), 18 g of a sample (lubricating oil composition) was collected, and four balls (SUJ-2) were used as test pieces. To a saturated amount, load weight 981N, time 2 hours, rotation speed 500min ^-1 , raise the temperature from room temperature to an appropriate temperature, perform a lubricity test, and wear from 4 balls wear area (mm ² ) The sex was evaluated.

[0053]

Example 1 As a base oil, a carbonate oil represented by the following formula (A) (viscosity 72 mm ² / S, hue L0.5, total acid value 0.01 mgKOH /
g)

[0054]

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100 parts by weight of the above carbonate oil and propylene glycol diglycidyl ether (epoxy A)
0.1 part by weight, and the resulting mixture was subjected to a copper plating suppression test, oxidation stability evaluation, and lubricity evaluation.

Table 1 shows the results.

[0057]

Example 2 In Example 1, propylene glycol diglycidyl ether (epoxy A) was replaced with 3,4-
Epoxycyclohexylmethyl (3,4-epoxy) Cyclohexanecarboxylate (Epoxy B) was subjected to a copper plating suppression test, oxidation stability evaluation and lubricity evaluation in the same manner as in Example 1 except that 0.1 part by weight of cyclohexanecarboxylate (epoxy B) was used. .

Table 1 shows the results.

[0059]

Example 3 In Example 1, propylene glycol diglycidyl ether (epoxy A) was replaced with 2,6-
A copper plating suppression test, oxidation stability evaluation, and lubricity evaluation were performed in the same manner as in Example 1 except that 0.25 parts by weight of di-t-butylparacresol (DBPC) was used.

Table 1 shows the results.

[0061]

Example 4 Copper plating was suppressed in the same manner as in Example 1 except that tricresyl phosphate (TCP) was used in an amount of 1.0 part by weight instead of propylene glycol diglycidyl ether (epoxy A). Test, oxidation stability evaluation and lubricity evaluation were performed.

Table 1 shows the results.

[0063]

Example 5 In Example 1, 0.1 part by weight of propylene glycol diglycidyl ether (epoxy A) and 0.25 of 2,6-di-tert-butylparacresol (DBPC) were used.
A copper plating suppression test, oxidation stability evaluation, and lubricity evaluation were performed in the same manner as in Example 1 except that parts by weight were used.

Table 1 shows the results.

[0065]

Example 6 In Example 1, 0.1 part by weight of propylene glycol diglycidyl ether (epoxy A), 2,6 parts
In the same manner as in Example 1 except that 0.25 parts by weight of -di-t-butylparacresol (DBPC) and 1.0 part by weight of tricresyl phosphate (TCP) were used, a copper plating inhibition test, an oxidation stability evaluation, and Lubricity evaluation was performed.

Table 1 shows the results.

[0067]

Example 7 In Example 1, the propylene glycol diglycidyl ether (epoxy A) was replaced with 3,4-
Epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate (epoxy B) 0.1 part by weight, 2,6-di-tert-butylparacresol (DBPC) 0.2
5 parts by weight and tricresyl phosphate (TCP)
A copper plating suppression test, oxidation stability evaluation, and lubricity evaluation were performed in the same manner as in Example 1 except that 1.0 part by weight was used.

Table 1 shows the results.

[0069]

Comparative Example 1 As a base oil, a hindered ester (viscosity: 6)
Propylene glycol diglycidyl ether (epoxy A) using 8 mm ² / sec, hue L0.5, total acid value 0.01 mgKOH / g)
A copper plating suppression test, oxidation stability evaluation, and lubricity evaluation were performed in the same manner as in Example 1 except that no was used.

Table 1 shows the results.

[0071]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 129: 10 129: 14 137: 04) C10N 30:00 30:06 30:10 40:30 (72) Inventor Kuni Takeuchi Hiko 3 Chikusa Beach, Ichihara City, Chiba Prefecture Inside Mitsui Petrochemical Industry Co., Ltd. (72) Inventor Haruo Saito 3-4 Kojimachi, Chiyoda-ku, Tokyo Japan San Oil Co., Ltd.

Claims (7)

[Claims] 1. It is selected from the group consisting of (i) a carbonate oil represented by the following general formula [I], and (ii) an epoxy group-containing compound, a phenolic antioxidant compound and a phosphate ester extreme pressure agent. A lubricating oil composition comprising at least one compound. R ¹ OCOOR ² ... [I] (In the formula [I], R ¹ and R ² are each independently a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having 2 to 30 carbon atoms.
Is a hydrocarbon group having an ether bond. ) 2. At least one compound selected from the group consisting of (ii) an epoxy group-containing compound, a phenolic antioxidant compound and a phosphate ester extreme pressure agent, based on 100 parts by weight of (i) carbonate oil. Content is 0.01 to
The lubricating oil composition according to claim 1, wherein the amount is 5 parts by weight. 3. The method according to claim 1, wherein the epoxy group-containing compound is a glycidyl ether compound represented by the following general formulas [1] to [3] or a compound having an epoxycyclohexyl group. The lubricating oil composition according to the above. Embedded image (In the formula, R ⁴ is a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having 2 to 50 carbon atoms and having an ether bond.) (In the formula, R ⁵ is a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having 2 to 50 carbon atoms and having an ether bond.) (In the formula, R ⁶ is a hydrocarbon group having 2 to 30 carbon atoms or a hydrocarbon group having an ether bond having 2 to 50 carbon atoms.) 4. The lubricating oil composition according to claim 1, wherein the phenolic antioxidant comprises a phenolic compound represented by the following general formula [4]. Embedded image (Wherein, R ⁷ is an alkyl group having 1 to 4 carbon atoms, l is 1 to 3
And m and n are integers of 0 to 3, and 1 ≦ l + m
+ N ≦ 6 is satisfied. ) 5. The lubricating oil composition according to claim 1, wherein the phosphate ester extreme pressure agent comprises a phosphate ester compound represented by the following general formula [5]. Embedded image (Wherein R ⁸ , R ⁹ and R ¹⁰ may be the same or different from each other, and are a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group having an ether bond having 2 to 30 carbon atoms. .) 6. The lubricating oil composition according to claim 1, wherein the lubricating oil composition is a lubricating oil composition for a refrigerator. 7. Hydrofluorocarbon (HFC, Hy)
7. The lubricating oil composition according to claim 6, wherein the lubricating oil composition contains (dro Fluoro Carbon).