JP2000034491A - Lubricating oil composition for internal combustion engines - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent oxidation stability and a deposit in a lubricated part exposed to a high temperature without impairing low fuel consumption performance, low-temperature viscosity characteristics, and prevention of basicity reduction under water mixing. Disclosed is a lubricating oil composition for an internal combustion engine having a prevention performance. The kinematic viscosity at 100 ° C. is 2 to 12 mm.
² / s mineral oil as a base oil, and (a)
A mineral oil having a kinematic viscosity at 100 ° C. of 20 to 50 mm ² / s, (b) an organic molybdenum compound, (c) an imide compound comprising a polybutenyl succinimide and a boron adduct of polybutenyl succinimide, and ( d) alkaline earth metal sulfonates having a total base number of 310 to 500 mg KOH / g and a total base number of 150 to 250 mg KOH / g
Is a lubricating oil composition for an internal combustion engine, wherein the alkaline earth metal salicylate is blended.

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 for an internal combustion engine, and more particularly, it is suitable as a lubricating oil for a gasoline engine, and has a low fuel consumption characteristic, a low temperature viscosity characteristic, and a base mixed with water. Without impairing the ability to prevent
The present invention relates to a lubricating oil composition for an internal combustion engine having excellent oxidation stability and high-temperature deposit prevention performance.

[0002]

2. Description of the Related Art With the recent improvement of automobile technology, high output and high revolution of an engine have been achieved, and therefore, a high-performance lubricating oil for an internal combustion engine which can withstand use under severe conditions has been demanded. . In addition, in order to respond to energy and environmental issues, it has become an essential requirement for lubricating oil for internal combustion engines to have a fuel-efficiency-improving effect. Recently, long drains have become an essential requirement in response to environmental issues. In addition, lubricating oils for internal combustion engines are required to have high lubrication performance.

[0003] In view of the above background, in recent years, friction modifiers such as organic molybdenum compounds have been used in lubricating oils for internal combustion engines of automobiles and the like for the purpose of improving fuel economy.
However, it has been clarified that a lubricating oil for an internal combustion engine using a friction modifier such as an organic molybdenum-based compound has a problem in that the TEOST deposit prevention performance specified in the ILSAC GF-2 standard is reduced. To solve the problem, see, for example, Japanese Patent Application Laid-Open No. Sho 59-122595.
Japanese Patent Application Laid-Open No. H11-216, proposes an engine oil in which a high-viscosity base oil is blended to reduce the amount of high-temperature deposit in a panel coking test. However, since the blending amount of the high-viscosity base oil is large, ILSAC GF has a low-temperature characteristic. Gelation Index (ASTM D-51) specified in the -2 standard
33) is not satisfied. Japanese Patent Application Laid-Open No. 8-283762 proposes an engine oil in which a boron-containing compound is blended to reduce the amount of high-temperature deposit in the hot tube test. A large amount of water contained in the engine oil may cause a large decrease in the base number of the engine oil, which may impair the low fuel consumption characteristics achieved by blending the organic molybdenum compound. Recently, engine oils with further improved oxidative stability have been eagerly desired due to the demand for long drainage of engine oils. However, at present, engine oils satisfying all of these performances have not yet been developed.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made from the above viewpoint, and has excellent oxidation stability without impairing low fuel consumption performance, low-temperature viscosity characteristics, and prevention of basicity reduction under water mixing. It is an object of the present invention to provide a lubricating oil composition for an internal combustion engine, which has lubricity and anti-deposit performance in a lubricating part exposed to a high temperature.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the purpose of the present invention can be effectively achieved by combining a specific amount of a base oil having a specific viscosity with a specific additive. It has been found that the present invention can be achieved, and the present invention has been completed. That is, the gist of the present invention is as follows. (1) Mineral oil having a kinematic viscosity at 100 ° C. of ² to 12 mm ² / s is used as a base oil.
Mineral oil having a kinematic viscosity of 20 to 50 mm ² / s,
(B) an organic molybdenum compound, and (c) an imide compound comprising a boron adduct of polybutenyl succinimide and polybutenyl succinimide, which is derived from a bisimide compound having a nitrogen amount derived from a monoimide compound of the imide compound. The weight ratio to the nitrogen amount is 0.4 to 2.0, and the weight ratio of the boron amount derived from the imide compound to the nitrogen amount is 0.05 to
The weight ratio of the amount of the alkaline earth metal derived from the imide compound which is 0.35 and (d) the sulfonate to the amount of the alkaline earth metal derived from the salicylate is 0.2 to 5.0.
An alkaline earth metal sulfonate having a total base number of 310 to 500 mg KOH / g and a total base number of 150 to 2
A lubricating oil composition for an internal combustion engine containing 50 mg KOH / g of an alkaline earth metal salicylate, wherein mineral oil of component (a) is 0.5 to 2.5% by weight, based on the total amount of the composition, and (b) ) The amount of molybdenum derived from the component is 100 to 2,
000 wt ppm, the amount of boron derived from the component (c) is 0.004 to 0.014% by weight, the amount of nitrogen derived from the component (c) is 0.04 to 0.12% by weight,
(D) The alkaline earth metal sulfonate of the component is 0.2 to 0.2%.
A lubricating oil composition for an internal combustion engine comprising 0.8% by weight and 0.3 to 3.0% by weight of an alkaline earth metal salicylate as the component (d). (2) The lubricating oil composition for an internal combustion engine according to (1), wherein (e)
A lubricating oil composition for an internal combustion engine containing an organic polysulfide compound as a component in an amount of 50 to 1,000 ppm by weight, based on the total amount of the composition, as sulfur. (3) The internal combustion engine according to (1) or (2), wherein the lubricating oil composition for an internal combustion engine contains, as a component (f), a pour point depressant in an amount of 0.1 to 3% by weight based on the total amount of the composition. Lubricating oil composition.

[0006]

Embodiments of the present invention will be described below. First, in the present invention, as a base oil,
It is important to use a mineral oil having a kinematic viscosity at 100 ° C. of ² to 12 mm ² / s. Preferably 3 to 8 mm ²
/ S. If the kinematic viscosity is less than 2 mm ² / s, evaporation loss is undesirably large. On the other hand, if it exceeds 12 mm ² / s, power loss due to viscous resistance increases, and a fuel efficiency improvement effect cannot be obtained, which is not preferable. As the mineral oil, for example, a distillate obtained by distilling a paraffinic-base crude oil, an intermediate-base crude oil or a naphthenic-base crude oil under normal pressure, or a residual oil obtained by normal-pressure distillation under reduced pressure, or a distillate obtained by a conventional method Therefore, refined oil obtained by refining, for example,
Solvent refined oils, hydrogenated refined oils, dewaxed oils, clay treated oils and the like can be mentioned, and those having the above viscosity range may be selected from them. Among them, highly refined mineral oil having a% CA of 10 or less is preferable. Those having a% CA of 5 or less are more preferred. These mineral oils having the above viscosity range can be used in combination of two or more kinds.

Next, the components (a) to (d) to be blended in the base oil will be described. (A ) It is necessary that the mineral oil has a kinematic viscosity at 100 ° C. of 20 to 50 mm ² / s. 20mm is less than ² / s, and decreases the high temperature deposit precipitation preventing performance, 50 mm ²
/ S, the specified Gelation Index
Can not be obtained. Preferably it is 20-40 mm < ² > / s. As the mineral oil, similarly to the base oil, for example, a distillate obtained by subjecting a paraffin-based crude oil, an intermediate-based crude oil or a naphthenic-based crude oil to atmospheric distillation, or a residual oil obtained by atmospheric distillation under reduced pressure, Or a refined oil obtained by purifying it according to a conventional method, for example, a solvent refined oil,
Examples include hydrogenated refined oil, dewaxed oil, clay treated oil, and the like, and those having the above viscosity range may be selected. Among them, highly refined mineral oil having a% CA of 10 or less is preferable. These mineral oils having the above viscosity range can be used in combination of two or more kinds. The amount of the component (a) is 0.5 to 2.5% by weight based on the total amount of the composition. If it is less than 0.5% by weight, the high-temperature deposit prevention performance is reduced. On the other hand, when the content exceeds 2.5% by weight, a predetermined Gelation Index cannot be obtained. Preferably it is 1.0 to 2.0% by weight.

Component ( b) Examples of the organic molybdenum compound include molybdenum dithiophosphite (MoDTP), molybdenum dithiocarbamate (MoDTC), and molybdenum amine salt. The component (b) can be used alone or in combination of two or more, and the compounding amount thereof is 100 to 2,000 ppm by weight as molybdenum. If it is less than 100 ppm by weight, the effect of reducing friction is not sufficiently exhibited. If the content exceeds 2,000 ppm by weight, no improvement in the friction reducing effect commensurate with the amount is observed, and coking deposits are likely to occur. Preferably, 3
The range is from 0.00 to 1,000 ppm by weight. ( C) Component An imide compound comprising a polybutenyl succinimide and a boron adduct of polybutenyl succinimide. The polybutenyl succinimide has the following general formula (I)

[0009]

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A monoimide compound represented by the following general formula (II)

[0011]

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There is a bisimide compound represented by the formula: Where:
R ¹ , R ³ and R ⁴ each have a number average molecular weight of 300 to
Shows 3,000 polybutenyl groups, which may be identical or different. R ² , R ⁵ and R ⁶ are each an alkylene having 2 to 4 carbon atoms, which may be the same or different. m is an integer of 1 to 10, and n is 0 or an integer of 1 to 10. In addition, the polybutenyl group mentioned here is obtained from polybutene obtained by polymerizing a mixture of 1-butene and isobutene.

The polybutenyl succinimide is obtained, for example, by preparing polybutene having a number average molecular weight of 300 to 3,000 or chlorinated polybutene having a number average molecular weight of 300 to 3,000 with maleic anhydride at 100 to 200 ° C. It can be obtained by reacting tenyl succinic anhydride with a polyamine. Depending on the reaction conditions, a monoimide body, a bisimide body, or a mixture of a monoimide body and a bisimide body is produced, and any of them can be used. Examples of the polyamine include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. Boron adduct of polybutenyl succinimide, for example, number average molecular weight 300 ~
After reacting 3,000 polybutene with maleic anhydride to obtain polybutenyl succinic anhydride, the above polyamine and boron oxide, boron halide, boric acid,
It is obtained by reacting with an intermediate obtained by reacting a boron compound such as a borate ester or an ammonium salt of boric acid to imidize. The amount of boron in this boron adduct is preferably in the range of 0.1 to 5% by weight.
As the imide compound of the component (c), a mixture of a boron adduct of polybutenyl succinimide and a polybutenyl succinimide is usually used. In the preparation, one with a reduced amount of boron may be used as it is.

In the imide compound (c), the weight ratio of the nitrogen derived from the monoimide of the imide compound to the nitrogen derived from the bisimide must be adjusted to 0.4 to 2.0. If it is less than 0.4, the oxidation stability decreases, and if it exceeds 2.0, the compatibility of the seal rubber decreases, which is not preferable. Further, the weight ratio of the amount of boron derived from the imide compound to the amount of nitrogen is 0.05 to 0.35.
Need to be adjusted. If it is less than 0.05, the performance of preventing high-temperature deposit precipitation is reduced, and if it exceeds 0.35, the water resistance is undesirably reduced.

The imide compound of the component (c) can be used alone or in combination of two or more kinds with polybutenyl succinimide and a boron adduct thereof. Boron content is 0.0
It is necessary that the content be in the range of 04 to 0.014% by weight.
If it is less than 0.004% by weight, the high-temperature deposit prevention performance cannot be obtained, and if it exceeds 0.014% by weight, the water resistance decreases, which is not preferable. Preferably, 0.005 to
It is in the range of 0.014% by weight. In addition, the amount of nitrogen is set to 0.0
It must be between 4 and 0.12% by weight. 0.
If it is less than 04% by weight, the high-temperature deposit prevention performance is lowered, and the dispersibility of sludge is also lowered. On the other hand, if it exceeds 0.12% by weight, the water resistance is lowered and the compatibility of the seal rubber is also lowered, which is not preferred. Preferably, it is in the range of 0.05 to 0.10% by weight.

( D) an alkaline earth metal sulfonate having a total base number of 310 to 500 mgKOH / g and a total base number of 150 to 250 mgK
OH / g mixture of alkaline earth metal salicylates. The alkaline earth metal sulfonate is an alkaline earth metal salt of various sulfonic acids, and is usually obtained by a method of carbonating an alkaline earth metal salt of various sulfonic acids. Examples of the sulfonic acid include aromatic petroleum sulfonic acid, alkyl sulfonic acid, aryl sulfonic acid, and alkylaryl sulfonic acid, and specifically, dodecylbenzene sulfonic acid, dilauryl cetyl benzene sulfonic acid, and paraffin wax-substituted benzene sulfonic acid. And polyolefin-substituted benzenesulfonic acid, polyisobutylene-substituted benzenesulfonic acid, and naphthalenesulfonic acid. The total base number of the alkaline earth metal sulfonate must be 310-500 mg KOH / g. If it is less than 310 mgKOH / g, the high-temperature deposit-preventing property is reduced, and if it exceeds 500 mgKOH / g, precipitation may occur, which is not preferable.

Alkaline earth metal salicylate is an alkali metal salt of alkyl salicylic acid and usually has 8 carbon atoms.
Alkylating the phenol with ~ 18 alpha-olefins,
Then, after a carboxyl group is introduced by a Kolbe-Schmidt reaction, it is obtained by a method of metathesis and carbonation. Specific examples of the alkyl salicylic acid include dodecyl salicylic acid, dodecyl methyl salicylic acid, tetradecyl salicylic acid, hexadecyl salicylic acid, octadecyl salicylic acid, and dioctyl salicylic acid.
The total base number of this alkaline earth metal salicylate is 150
Must be ~ 250 mg KOH / g. 150mg
/ G, the oxidative stability is reduced, and 250 mgK
If it exceeds OH / g, the water resistance is undesirably reduced. In the present invention, it is necessary to adjust the weight ratio of the amount of alkaline earth metal derived from the sulfonate to the amount of alkaline earth metal derived from salicylate to 0.2 to 5.0. If it is less than 0.2, the high-temperature deposit-preventing property is reduced, and if it is more than 5.0, the oxidation stability is undesirably reduced.

As the component (d), each of the sulfonate and salicylate may be used alone or in combination of two or more. Regarding the amount of the component (d), the alkaline earth metal sulfonate is 0.2 to 0.8% by weight based on the total amount of the composition. If it is less than 0.2% by weight, the high-temperature deposit-preventing property decreases, and if it exceeds 0.8% by weight, the water resistance decreases, which is not preferable. Preferably, it is 0.4 to 0.8% by weight.

On the other hand, alkaline earth metal salicylates are:
It is 0.3 to 3.0% by weight based on the total amount of the composition. 0.
If it is less than 3% by weight, oxidative stability decreases, and if it exceeds 3.0% by weight, the high-temperature deposit-preventing property decreases, which is not preferable. Preferably, it is 1.0 to 2.5% by weight. Examples of the alkaline earth metals of the above-mentioned sulfonates and salicylates include calcium, barium, magnesium and the like, but calcium is preferred in terms of effect.

In the present invention, an organic polysulfide compound is added as a component (e) to Gelation In, in order to further improve the performance of preventing high-temperature deposit precipitation.
In order to further improve dex, it is preferable to add a pour point depressant as the component (f). ( E) Component The organic polysulfide compound is an organic compound in which two or more sulfur atoms are adjacently bonded in a molecule. Preferred organic polysulfides include sulfurized olefins and dihydrocarbyl polysulfides.

Examples of the sulfurized olefin include the following general formula (III): R ⁷ -S _x -R ⁸ (III) (wherein, R ⁷ is an alkenyl group having 2 to 15 carbon atoms, and R ⁸ is Represents an alkyl group or an alkenyl group having 2 to 15 carbon atoms,
x shows the integer of 2-8. And the like. This compound is obtained by reacting an olefin having 2 to 15 carbon atoms or a dimer or tetramer thereof with a sulfurizing agent such as sulfur or sulfur chloride. As the olefin, propylene, isobutene, diisobutene and the like are preferable.

The dihydrocarbyl polysulfide is represented by the following general formula (IV): R ⁹ -S _y -R ¹⁰ (IV) (wherein R ⁹ and R ¹⁰ each represent an alkyl having 1 to 20 carbon atoms) A group or a cyclic alkyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms, which may be the same or different from each other, and y is And an integer of 2 to 8). Where R ⁹ and R ¹⁰
When is an alkyl group, it is called an alkyl sulfide.

Specific examples of R ⁹ and R ¹⁰ in the general formula (IV) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s
ec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, various dodecyl groups, cyclohexyl groups, cyclooctyl groups, phenyl groups, naphthyl groups , Tolyl, xylyl, benzyl, phenethyl and the like.

Examples of the dihydrocarbyl polysulfide include dibenzyl polysulfide and di-t.
Preferred examples include tert-nonyl polysulfide, di-tert-dodecyl polysulfide, di-tert-butyl polysulfide, dioctyl polysulfide, diphenyl polysulfide, dicyclohexyl polysulfide, and the like.

Among them, dihydrocarbyl polysulfides such as di-tert-nonyl polysulfide, di-tert-dodecyl polysulfide and di-tert-butyl polysulfide are particularly preferred. The component (e) can be used singly or in combination of two or more. The compounding amount is 50 to 1,000 ppm by weight as sulfur based on the total amount of the composition. If it is less than 50 ppm by weight, the high-temperature deposit prevention performance may not be exhibited. If it exceeds 1,000 ppm, the high-temperature deposit prevention performance corresponding to the amount may not be observed. Preferably, 100 to 600 ppm by weight
Range.

The component ( f) pour point depressant includes polyalkyl methacrylate, chlorinated paraffin-naphthalene condensate, polyalkyl polystyrene and the like. Component (f) can be used alone or in combination of two or more.
The compounding amount is 0.1 to 3% by weight based on the total amount of the composition. If it is less than 0.1% by weight, Gelation
Index improvement may not be effective,
If it exceeds weight%, the Gelation corresponding to the amount
The effect of the improvement of the Index may not be recognized.
Preferably, it is in the range of 0.3 to 1.5% by weight.

Further, in order to improve the physical properties of the lubricating oil, various additives conventionally used in lubricating oils such as ZnDTP are usually added to the composition of the present invention so long as the object of the present invention is not impaired. Other anti-wear agents, viscosity index improvers such as polymethacrylates, olefin copolymers, etc., antioxidants such as phenolic, amine-based, sulfur-based, friction modifiers such as polyhydric alcohol partial esters, amines and amides,
Metal deactivators such as benzotriazole and thiadiazole, rust inhibitors such as alkenyl succinic acid and its partial esters, polyalkylene ethers and polyalkylene alkyl phenyl ethers, and defoamers such as silicone oil, based on the total amount of the composition. , (A) to (f), all additives other than the components can be blended in the range of 3 to 10% by weight.

[0028]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 16 and Comparative Examples 1 to 9 Base oil (paraffinic mineral oil: kinematic viscosity at 100 ° C.
3 mm ² / s,% CA = 0) and the following additives were blended in the proportions shown in Tables 1 and 2 to obtain lubricating oil compositions of Examples and Comparative Examples. The lubricating oil composition was evaluated for the amount of high-temperature deposit, the coefficient of friction, the water resistance, the high-temperature oxidation stability, and the low-temperature viscosity characteristics by the following methods, and the results were shown in Table 1 (Example) and Table 2 (Comparative). Example).

(1) Additives (a) Ingredients ・ Mineral oil 1 (paraffinic hydrogenated mineral oil: 100 ° C.)
Kinematic viscosity 30.8mm ^Two/ S,% CA = 0, Example
1, 4-16, Comparative Examples 1, 3-9)-Mineral oil 2 (paraffin-based hydro-reformed mineral oil: at 100 ° C)
Kinematic viscosity 32.8mm ^Two/ S,% CA = 3.9, implemented
Example 2)-Mineral oil 3 (paraffin-based hydro-reformed mineral oil: 100 ° C
Kinematic viscosity 32.0mm ^Two/ S,% CA = 8.7, implemented
Example 3) (b) Component MoDTC (Mo content 4.5% by weight, Examples 1 to 5
8-16, Comparative Examples 2-9) MoDTP (Mo content 9.0% by weight, Example 6) Mo amine salt (Mo content 4.5% by weight, Example 7) Component (c) Polybutenyl Succinic monoimide (of polybutenyl group)
Number average molecular weight 950, nitrogen content 1.8% by weight, Example 1
-16, Comparative Examples 1, 2, 4, 7-9)-Boron adduct of polybutenyl succinic monoimide (Po
Number average molecular weight of the ribenyl group: 950, nitrogen content: 2.3
%, Boron content 1.9% by weight, Examples 1-8,10-10
16, Comparative Examples 1 to 3, 5, 7 to 9) Polybutenyl succinic bisimide A (polybutenyl group)
Number average molecular weight of 950, nitrogen content of 1.1% by weight, Examples
1-7, 10-14, 16, Comparative Examples 1-9) polybutenyl succinic bisimide B (polybutenyl group
A number average molecular weight of 2,000, a nitrogen content of 0.86% by weight,
Examples 8, 15)-Boron adduct of polybutenyl succinic monoimide (Polybutenyl succinate monoimide)
The number average molecular weight of the ribenyl group is 2,000, and the nitrogen content is 0.1.
79% by weight, boron content 0.25% by weight, Example 9, ratio
Comparative Example 6)

Component (d) Ca sulfonate A (total base number 450 mg KOH /
g, Ca content 14.9% by weight, Examples 1 to 11, 13 to
16, Comparative Examples 1 to 8) Ca sulfonate B (total base number 320 mg KOH /
g, Ca content 12.5% by weight, Example 12) Ca salicylate A (total base number 170 mgKOH /
g, Ca content 6.0% by weight, Examples 1 to 13, 16 and Comparative Examples 1 to 9 • Ca salicylate B (total base number 230 mgKOH /
g, Ca content 8.1% by weight Examples 14, 15) Ca phenate (total base number 260 mg KOH / g, C
a content: 9.2% by weight, Comparative Example 9) The total base number is a value measured by JIS K2501 (perchloric acid method). (E) Component Di-tert-dodecyl trisulfide (S content 2
0.7% by weight, Example 16) (f) Component-Pour point depressant (polymethacrylate; weight average molecular weight 6,000, Examples 1 to 16, Comparative Examples 1 to 9)

(Other additives; Examples 1 to 16, Comparative Examples 1 to 9) ZnDTP (secondary type, based on the total amount of the composition,
P content: 0.1% by weight) Viscosity index improver (polymethacrylate; mixture of weight average molecular weights of 180,000 and 480,000) Antioxidant (phenolic, 0.1% based on the total amount of the composition)
5% by weight) ・ Antifoaming agent (silicone oil, 0.00% based on the total amount of the composition)
1% by weight)

(2) Evaluation method (i) High-temperature deposit amount (mg) Chrysle specified by ILSAC GF-2
r TEOST Test (Method 33) (AS
TM RR: D02: 1391).
The ILSAC GF-2 standard value is 60 mg or less. (Ii) Coefficient of friction (μ) Using a block-on-ring tester (LFW-1), rotation speed is 1,400 rpm, load is 20 lbs, oil temperature is 80 ° C, time is 15 minutes, and the amount of oil in which half of the ring is immersed in sample oil is tested. Using a Falex H-60 test block for the block and a Falex S-10 test ring for the test ring, a load is applied to the block, and the resistance generated when the ring is rotated is detected by a strain gauge, and the friction coefficient is determined. Calculated.

(Iii) Water resistance (decrease rate of total base number (%) after water mixing stability test) 100 g of a sample (97.5 g of oil, 97.5 g of oil) was determined in accordance with the hydraulic oil hydrolysis test (ASTM D-2619). Water 2.5
g) was treated at 62 ° C. for 24 hours, water and oil were centrifuged, and the supernatant was further dehydrated at 80 ° C. for 10 hours.
The total base number (JIS K 2501; hydrochloric acid method) of the obtained oil was measured, and the total base number (JIS K 25
01; hydrochloric acid method). (Iv) High temperature oxidation stability ISOT (JIS K 2514) test, 150 ° C, 7
Total base number after 2 hours (JIS K 2501; hydrochloric acid method)
Was evaluated. (V) Low temperature viscosity characteristics Gelation Index was obtained from ASTM D-513.
3 was measured.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

[Table 6]

[0040]

[Table 7]

[0041]

Industrial Applicability The lubricating oil composition for an internal combustion engine of the present invention has excellent oxidation stability and high temperature without impairing low fuel consumption performance, low-temperature viscosity characteristics, and prevention of basicity reduction under water mixing. It has a deposit preventing performance in the exposed lubricating part, and is particularly practical as an engine oil.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C10M 159: 24 159: 22) C10N 10:04 10:12 20:02 30:02 30:04 30:06 30:08 30:10 40:25 60:14 F term (reference) 4H104 BE11C BF03C BG10C BG11C BH04C BJ05C DA02A DB06C DB07C EA02A EA21C EA22C EB05 FA02 FA06 LA02 LA04 LA05 LA13 PA41

Claims (3)

[Claims] A kinematic viscosity at 100 ° C. of 2 to 12 mm
² / s mineral oil as a base oil, and (a)
A mineral oil having a kinematic viscosity at 100 ° C. of 20 to 50 mm ² / s, (b) an organic molybdenum compound, and (c) an imide compound comprising a boron adduct of polybutenyl succinimide and polybutenyl succinimide, The weight ratio of the nitrogen amount derived from the monoimide body of the imide compound to the nitrogen amount derived from the bisimide body is 0.4 to 2.0, and the weight ratio of the boron amount derived from the imide compound to the nitrogen amount is 0.0.
The weight ratio of the amount of the alkaline earth metal derived from the sulfonate to the amount of the alkaline earth metal derived from the salicylate is 0.2 to 0.25;
5.0, the total base number is 310-500 mg KOH /
g of alkaline earth metal sulfonate and a total base number of 15
A lubricating oil composition for an internal combustion engine containing 0 to 250 mg KOH / g of an alkaline earth metal salicylate, wherein mineral oil of the component (a) is 0.5 to 2.5% by weight, based on the total amount of the composition. (B) The amount of molybdenum derived from the component is 100
2,000 ppm by weight, and the amount of boron derived from the component (c) is 0.004 to 0.014% by weight;
The amount of nitrogen derived from the component (c) is 0.04 to 0.12% by weight, the content of the alkaline earth metal sulfonate of the component (d) is 0.2 to 0.8% by weight, A lubricating oil composition for an internal combustion engine, wherein the alkaline earth metal salicylate is 0.3 to 3.0% by weight. 2. The lubricating oil composition for an internal combustion engine according to claim 1, wherein the component (e) is an organic polysulfide compound.
A lubricating oil composition for an internal combustion engine containing 50 to 1,000 ppm by weight of sulfur based on the total amount of the composition. 3. The internal combustion engine according to claim 1, wherein the lubricating oil composition for an internal combustion engine contains, as a component (f), a pour point depressant in an amount of 0.1 to 3% by weight based on the total amount of the composition. Lubricating oil composition.