JP2010189657A - Lubricating oil composition for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil composition for an internal combustion engine having excellent performance in prevention of high temperature deposit (performance in prevention of TEOST deposit) without spoiling low fuel consumption performance which is required to deal with energy and environmental problems. <P>SOLUTION: The lubricating oil composition for an internal combustion engine comprises a lubricating oil component as base oil having kinematic viscosity at 100°C of 2-13 cSt and containing 1-20 wt.% of a heavy component having a boiling point of 480°C or higher and 27.3-49.5 wt.% of a heavy component having a boiling point of 430°C or higher in a boiling point range measured by gas chromatograph distillation. The composition contains an organomolybdenum-based compound as a friction modifier, and calcium sulfonate and/or calcium salicylate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lubricating oil composition for an internal combustion engine. More specifically, the present invention has excellent low fuel consumption performance and high-temperature deposit prevention performance, for example, high-temperature oxidation stability evaluated by TEOST (Thermo-Oxidation Engine Oil Simulation Test). The present invention relates to a lubricating oil composition for an internal combustion engine containing a lubricating base oil having excellent properties.

  Lubricants for internal combustion engines such as automobiles are mainly used to lubricate various sliding surfaces such as valve rings including piston rings and cylinder liners, crankshafts, bearing cams of connecting rods and valve lifters, as well as engine cooling and combustion products. It has the function of preventing and dispersing rust and corrosion. Therefore, in the lubricating oil for internal combustion engines, it is important to reduce friction and prevent wear on various sliding surfaces in the internal combustion engine. Furthermore, various performances such as prevention of heat and oxidation deterioration, cleanliness dispersibility, and corrosion resistance However, with the recent enhancement of performance and output of internal combustion engines, there is a demand for high-performance lubricating oil that can withstand use under severe conditions. In particular, having an effect of improving fuel efficiency in response to energy environment problems is an essential required quality of lubricating oil for internal combustion engines, and the use of friction modifiers is indispensable. Various friction modifiers have been developed, but organic molybdenum compounds are effective and are most often used.

  However, lubricating oils for internal combustion engines using friction modifiers such as organic molybdenum compounds have high temperature oxidation stability, in particular, gasoline engine oil standards (GF-2) established by the International Lubricant Standardization and Approval Committee (ILSAC). The present inventors have clarified that the problem that the high-temperature deposit prevention performance, that is, the TEOST deposit prevention performance decreases in the presence of nitrogen oxides defined in (1) is caused.

  The high temperature deposit prevention performance is used as an evaluation standard for the coking property of a turbo bearing of an internal combustion engine, and is an important required quality for a new fuel-efficient lubricating oil in the future. Satisfying this is an unavoidable issue for future development of high-performance lubricants with low fuel consumption. Conventionally, the oxidative stability of lubricating oil is addressed by the addition of amine-based antioxidants and phenol-based antioxidants in addition to the action of natural inhibitors such as sulfur compounds contained in the base oil. For example, alkylated phenyl-α-naphthylamine, P, P′-dialkyldiphenylamine, phenothiazine and the like are used as amine antioxidants, and 2,6-di-tert-butylphenol, 2 as phenolic antioxidants. , 6-di-t-butylparacresol, 4,4′-methylenebis (2,6-di-t-butylphenol) and the like are used. However, with these antioxidants alone, the improvement in the high temperature deposit prevention performance under the above severe conditions is extremely small, and the low fuel consumption lubricating oil having the high temperature deposit prevention performance is not impaired without impairing the low fuel consumption performance. It has not yet been developed.

  Accordingly, an object of the present invention is to provide an internal combustion engine containing a low fuel consumption lubricating base oil having the above-mentioned high temperature deposit prevention performance while maintaining both excellent low fuel consumption performance, that is, both initial fuel consumption performance and low fuel consumption sustainability. An object of the present invention is to provide a lubricating oil composition.

  Accordingly, as a result of intensive studies to solve the above problems, the present inventors have made the base oil component of the lubricating oil composition for internal combustion engines contain a substance having fluidity in a specific high boiling range. Thus, it has been found that the high-temperature deposit prevention performance can be imparted without sacrificing the low fuel consumption performance, and the present invention has been completed based on these findings.

That is, the present invention
A lubricating oil component having a kinematic viscosity at 100 ° C. of 2 cSt to 13 cSt and containing 1% by weight or more of a heavy component of 480 ° C. or higher based on the total weight of the lubricating base oil in a boiling range measured by gas chromatographic distillation The present invention relates to a lubricating oil composition for an internal combustion engine.

Furthermore, as a preferred embodiment of the present invention,
(1) A kinematic viscosity at 100 ° C. is 2 cSt to 13 cSt, and a heavy component of 480 ° C. or higher in the boiling range measured by the gas chromatographic distillation (hereinafter referred to as “GCD 480 ° C. residual heavy component” if necessary). A lubricating oil composition for an internal combustion engine comprising a lubricating oil component containing 1 wt% to 20 wt% based on the total weight of the lubricating base oil;
(2) A lubricating oil composition for an internal combustion engine having a kinematic viscosity at 100 ° C. of 3 cSt to 6 cSt and a base oil of a lubricating oil component containing 1 wt% to 20 wt% of GCD480 ° C. residual heavy component,
(3) Kinematic viscosity at 100 ° C. is 2 cSt to 13 cSt, heavy component 20 wt% to 70 wt% at 430 ° C. or higher in the boiling range measured by gas chromatographic distillation based on the total weight of the lubricating base oil, 450 Based on a lubricating oil component containing 4 wt% to 50 wt% of a heavy component having a temperature equal to or higher than ℃ (hereinafter referred to as "GCD450 ° C residual heavy component" if necessary) and 1 wt% or more of a GCD480 ° C remaining heavy component. A lubricating oil composition for an internal combustion engine can be provided.

  The lubricating oil composition for an internal combustion engine of the present invention is based on a lubricating oil component containing 1 wt% or more of a heavy component at 480 ° C. or higher in the boiling range measured by gas chromatographic distillation. It is possible to provide a high-performance lubricating oil that can exhibit excellent high-temperature deposit prevention performance without impairing fuel efficiency and can withstand future quality requirements.

  In this specification, “gas chromatographic distillation” refers to ASTM D2887 “Standard Test Method for Boiling Range Distribution of Petroleum Fraction by Gas Chromatography” and uses gas chromatography to simulate the measurement of the boiling point of lubricating oil by distillation. Means to do.

  One of the peculiarities of the present invention is that, when the high temperature deposit is taken into account, the presence of heavy components at 480 ° C. or higher in the boiling point range measured by gas chromatographic distillation according to ASTM D2887 in the lubricating base oil for internal combustion engines Has contributed to the high-temperature deposit suppression effect, and by containing 1% by weight or more of this heavy component based on the total weight of the lubricating base oil, high-temperature deposit prevention is achieved without impairing fuel efficiency. This is to realize a high-performance internal combustion engine lubricating oil composition using a lubricating oil component having performance as a base oil.

  Hereinafter, the present invention will be described in detail.

  As the base oil of the lubricating oil composition for an internal combustion engine of the present invention, a mineral base oil, a synthetic base oil or a mixed oil thereof can be used. Examples of mineral oil base oils include paraffinic mineral oils, intermediate base mineral oils, naphthenic base mineral oils, etc., and mixed base materials include light neutral oil, medium neutral oil, heavy neutral oil, and bright stock. Such as solvent refined oil or hydrotreated oil and wax isomerized oil can be used. As the synthetic base oil, poly-α-olefin, polyalkylene glycol, dibasic acid ester, polyol ester, organopolysiloxane and the like can be used. These base oils are each used alone or mixed so that the kinematic viscosity at 100 ° C. is 2 cSt to 13 cSt, preferably 3 cSt to 6 cSt suitable as a lubricating oil for an internal combustion engine. When lubricating oil is used in an internal combustion engine, if the 100 ° C. kinematic viscosity of the lubricating oil is less than 2 cSt, the oil film may not be sufficiently formed and the sliding surface may be worn. On the other hand, if it exceeds 13 cSt, the friction loss increases. However, there arises a problem that the low fuel consumption performance is impaired.

  As described above, the base oil used in the lubricating oil composition for internal combustion engines of the present invention contains a heavy component of 480 ° C. or higher in the boiling range measured by gas chromatographic distillation defined in accordance with ASTM D2887. Is essential, and the content thereof is 1% by weight or more, preferably in the range of 1% by weight to 20% by weight, based on the total weight of the lubricating base oil. In addition to the essential component 480 ° C. or higher base oil component as a heavy component, a lubricating oil component of 450 ° C. or higher is 5 wt% or more, preferably 5 wt% to 50 wt% based on the total weight of the lubricating base oil. Further, a lubricating oil component of 430 ° C. or higher is contained in a range of 20% by weight to 70% by weight, preferably 30% by weight to 60% by weight, based on the total weight of the lubricating base oil. Can be made. These lubricating oil components at 430 ° C. or higher, particularly 480 ° C. or higher, are presumed to perform dispersion dilution of the produced deposit under high temperature conditions. In the lubricating base oil, there is no heavy component of 480 ° C. or higher, or even if a component of 480 ° C. or higher is present, if the content is less than 1% by weight, the formation of the high temperature deposit (TEOST deposit) is suppressed On the other hand, even if the content exceeds 20% by weight, the rate of increase may not be able to reduce the high-temperature deposit amount, but may cause the disadvantage of lack of fuel efficiency due to increased viscosity of the lubricating oil. There is.

  The base oil used in the lubricating oil composition for an internal combustion engine of the present invention can employ any manufacturing method, and is not limited, but is manufactured by blending the various mixed base materials. Can do.

  The manufacturing method of the lubricating oil mixed base material is arbitrary and is not particularly limited, but the mineral oil based mixed base material is, for example, a lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil as a raw material, It can be produced by combining purification steps such as solvent dewaxing, solvent extraction, hydrocracking, hydrotreating, hydrorefining, solvent dewaxing, catalytic dewaxing, and clay treatment.

  The solvent refined oil is a mixed base material obtained by using a solvent treatment such as solvent extraction as a main purification step. For example, it can be obtained by subjecting a raffinate obtained by treating a vacuum distilled lubricating oil distillate or residual oil with an aromatic extraction solvent such as phenol or furfural to solvent dewaxing or catalytic dewaxing. The residual oil is subjected to solvent removal using a propane solvent and subjected to a removal treatment.

  In addition, the above-mentioned hydrotreated oil can be produced, for example, by bringing a lubricating oil raw material into contact with hydrogen under hydrotreating conditions in the presence of a hydrotreating catalyst. Examples of hydrotreating catalysts include oxides and / or sulfides such as cobalt, molybdenum, nickel, chromium, tungsten, platinum, and palladium, and hydrogenation active components such as reduced nickel as refractory inorganic materials such as alumina and silica-alumina. Those supported on an oxide support are used, and the hydrogenation active component is preferably used in combination of two or more. In particular, a combination of cobalt-molybdenum and cobalt-molybdenum-nickel is preferable from the viewpoint of catalytic activity and activity maintenance ability. By such hydrotreating, it is possible to obtain highly hydrotreated oil mainly containing saturated hydrocarbons such as paraffinic and naphthenic hydrocarbons with an aromatic hydrocarbon content of 2% by weight or less.

  Further, the isomerized oil obtained by bringing the wax into contact with hydrogen in the presence of a wax isomerization catalyst contains a heavy component remaining at GCD480 ° C. and has a high viscosity index, so that it is used in the lubricating oil composition of the present invention. It is useful as a base material for mixing base oil. Even if the lubricant base oil containing GCD480 ° C residual heavy components that contribute to the suppression of the formation of high-temperature deposits has the same viscosity level, the distribution of the distilled components differs depending on the distillation conditions. Can be manufactured by widening.

  The mixed base material for the lubricating base oil for internal combustion engines of the present invention is preferably solvent refined oil, wax isomerized oil, highly hydrotreated oil, etc. when compared at the same viscosity level. When the viscosity is about 4 cSt, a base oil containing GCD480 ° C. residual heavy component can be produced by blending wax isomerized oil at a ratio of 3% by weight or more based on the total weight of the lubricating base oil.

  Moreover, the manufacturing method of the mixing base material of synthetic base oil is also arbitrary, and what was manufactured by the conventional method can be used. For example, by preparing a poly-α-olefin having a kinematic viscosity at 100 ° C. of about 6 cSt, a lubricating base oil having a GCD480 ° C. residual heavy component can be obtained.

As the organic molybdenum compound as a friction modifier used in the lubricating oil composition for internal combustion engines of the present invention,
For example, the following general formula [I]

And general formula [II]

The compound represented by these can be employ | adopted.

In the general formulas [I] and [II], R _{1 to} R ₈ may be the same as or different from each other, and are each a hydrocarbon group having 1 to 30 carbon atoms. Examples of the hydrocarbon group include linear or branched alkyl groups having 1 to 30 carbon atoms; alkenyl groups having 2 to 30 carbon atoms; cycloalkyl groups having 4 to 30 carbon atoms; aryl groups having 6 to 30 carbon atoms; An aryl group or an arylalkyl group can be exemplified. Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group. Group, hexadecyl group, heptadecyl group, octadecyl group, and the like, and branched alkyl groups thereof. Particularly, an alkyl group having 3 to 8 carbon atoms is preferable. X ₁ and X ₂ are oxygen atoms or sulfur atoms, and Y ₁ and Y ₂ are oxygen atoms or sulfur atoms.

  Accordingly, representative examples of the compound represented by the above general formula [I] include sulfurized oxymolybdenum propyldithiocarbamate, sulfurized oxymolybdenum butyldithiocarbamate, sulfurized oxymolybdenum pentyldithiocarbamate, sulfurized oxymolybdenum hexyldithiocarbamate, sulfurized oxymolybdenum heptyl. And dithiocarbamate, sulfurized oxymolybdenum octyldithiocarbamate, sulfurized oxymolybdenum 2-ethylhexyldithiocarbamate, sulfurized oxymolybdenum dodecyldithiocarbamate, sulfurized oxymolybdenum octadecyldithiocarbamate and the like, and compounds having these branched alkyl groups. As a compound of the general formula [II], sulfurized oxymolybdenum propyl phosphorodithioate, sulfurized oximolyb Butyl phosphorodithioate, sulfurized oxymolybdenum pentyl phosphorodithioate, sulfurized oxymolybdenum hexyl phosphorodithioate, sulfurized oxymolybdenum heptyl phosphorodithioate, sulfurized oxymolybdenum octyl phosphorodithioate, sulfurized oxymolybdenum dodecyl phosphorodithioate And oxymolybdenum octadecyl phosphorodithioate, sulfurized oxymolybdenum oleyl phosphorodithioate and the like, and branched alkyl groups or alkenyl groups thereof.

  The organomolybdenum compound is added to the base oil in a proportion of 100 ppm to 3000 ppm, preferably 200 ppm to 1500 ppm, based on the total weight of the lubricating oil composition.

Examples of the peroxide decomposing agent used in the lubricating oil composition for an internal combustion engine of the present invention include a sulfur compound and a sulfur / phosphorus compound. As the sulfur-based compounds, sulfurized fats and oils such as sulfurized palm oil and sulfurized dipentene are used, and the general formula [III]
R ⁹ -S _X -R ¹⁰ [III]
(In the above general formula [III], R ⁹ and R ¹⁰ may be the same or different and each is a hydrocarbon group having 1 to 20 carbon atoms, and x is an integer of 1 to 4) is there.)
In addition to dialkyl sulfide represented by, for example, di-n-butyl sulfide and dicetyl sulfide, diphenyl sulfide and the like and dialkyl polysulfide such as di-n-butyl disulfide, dibenzyl disulfide, diphenyl disulfide and the like are used. be able to.

  On the other hand, zinc dialkyldithiophosphate, zinc diallyldithiophosphate and the like can be used as the sulfur / phosphorus compound.

  Content of a sulfur type compound is 100 ppm-4000 ppm as a sulfur content on the basis of the total weight of the lubricating oil composition, and preferably ranges from 200 ppm to 2000 ppm. It is estimated that the sulfur-based compound contributes to the improvement of the fuel efficiency by promoting the adhesion of MoSx to the metal surface.

  Examples of metal detergents used in the lubricating oil composition for internal combustion engines of the present invention include phenates, sulfonates, salicylates, phosphonates of alkaline earth metals such as barium (Ba), calcium (Ca), and magnesium (Mg). In particular, it is possible to use at least one compound selected from the group consisting of Ca-sulfonate, Mg-sulfonate, Ca-phenate, Mg-phenate, Ca-salicylate and Mg-salicylate. it can. Although the influence which it has on metal type detergents on high temperature sludge formation prevention changes with types, especially Ca-sulfonate and Ca-salicylate are preferable since the effect with respect to a high temperature sludge prevention effect is large.

  These metallic detergents can be used in a proportion of 0.5 to 20% by weight, preferably 1 to 10% by weight, based on the total weight of the lubricating oil composition.

  The ashless detergent / dispersant used in the lubricating oil composition for internal combustion engines of the present invention is at least one selected from the group consisting of alkenyl succinimides, boron derivatives of alkenyl succinimides, benzylamine, and boron derivatives of benzylamine. Compounds can be used. The ashless detergent / dispersant has different high-temperature deposit prevention effects depending on the type, but benzylamine and alkenyl succinimide are more preferable.

  The ashless detergent-dispersant can be used in a proportion of 1% to 15% by weight, preferably 2% to 10% by weight, based on the total weight of the lubricating oil composition.

  Examples of the antiwear agent used in the lubricating oil composition for internal combustion engines of the present invention include zinc dithiophosphate (ZnDTP) and zinc dithiocarbamate (ZnDTC) represented by the following general formulas [IV] and [V]. Can do.

In the above general formulas [IV] and [V],
R _{11 to} R ₁₄ may be the same as or different from each other, and are each a hydrogen atom or a hydrocarbon group having 1 to 26 carbon atoms. The hydrocarbon group is a first one having 1 to 26 carbon atoms. Primary (secondary) alkyl group; alkenyl group having 2 to 26 carbon atoms; cycloalkyl group having 6 to 26 carbon atoms; aryl group, alkylaryl group or arylalkyl group having 6 to 26 carbon atoms; Or it is a hydrocarbon group containing an ester bond, an ether bond, an alcohol group or a carboxyl group. R _{11 to} R ₁₄ are preferably an alkyl group having 2 to 12 carbon atoms, a cycloalkyl group having 8 to 18 carbon atoms, and an alkylaryl group having 8 to 18 carbon atoms, and each is the same or different from each other. May be.

  Each of ZnDTP and ZnDTC can be used alone or in combination, and the use ratio thereof is 0.1 wt% to 7 wt%, preferably 1 wt% based on the total weight of the lubricating oil composition ~ 5% by weight.

  As the antioxidant, conventionally known phenol-based antioxidants and amine-based antioxidants can be selected and used. Specific examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol; 2,6-di-t-butyl-4-ethylphenol; 2,4-dimethyl-6-t- 4,4'-methylenebis (2,6-di-t-butylphenol); 4,4'-bis (2-methyl-6-t-butylphenol); 2,2'-methylenebis (4-ethyl-6) -T-butylphenol); 2,2'-methylenebis (4-methyl-6-t-butylphenol); 4,4'-butylidenebis (3-methyl-6-t-butylphenol); 4,4'-isopropylidenebis (2,6-di-t-butylphenol); 2,2′-methylenebis (4-methyl-6-nonylphenol); 2,2′-isobutylidenebis (4,6-dimethylphenol) 2,2′-methylenebis (4-methyl-6-cyclohexylphenol); 2,6-di-tert-butyl-4-methylphenol; 2,6-di-tert-butyl-4-ethylphenol; -Dimethyl-6-tert-butylphenol; 2,6-di-tert-alpha-dimethylamino-p-cresol; 2,6-di-tert-butyl-4 (N, N'-dimethylaminomethylphenol); 4'-thiobis (2-methyl-6-tert-butylphenol); 4,4'-thiobis (3-methyl-6-tert-butylphenol); 2,2'-thiobis (4-methyl-6-tert-butylphenol) In addition, examples of amine-based antioxidants include alkylated diphenylamine and alkylated phenyl-α-naphthylamine. These are usually used in a proportion of 0.05% by weight to 5% by weight.

  In the lubricating oil composition for an internal combustion engine of the present invention, other additives such as a viscosity index improver, a pour point depressant, a rust preventive, and an antifoaming agent are added as necessary as long as the purpose of the present invention is not impaired. Corrosion inhibitors and the like can be added as appropriate.

Examples of the viscosity index improver include polymethyl methacrylate, polyisobutylene, ethylene-propylene copolymer, styrene-butadiene hydrogenated copolymer, etc., and usually 0.5 wt% to 35 wt%. Used in proportions.

  Examples of the rust preventive include alkenyl succinic acid or a partial ester thereof, and can be appropriately added.

  Examples of the antifoaming agent include dimethylpolysiloxane and polyacrylate, which can be added as appropriate.

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

The performance evaluation of the lubricating oil compositions for internal combustion engines shown in Examples and Comparative Examples was evaluated by the following method.
1) High-temperature deposit prevention performance (TEOST (Thermo-Oxidation Engine Oil Simulation Test)) (See SAE Paper 932837)
1. Oxidation step 1. Formation of oxidation precursor in the reaction chamber; The deposit is divided into two sections, and the following test conditions are adopted to measure the amount of deposit generated. The amount of deposit generated is used as an evaluation standard for high temperature deposit prevention performance.

・ Pump speed: 0.45 ml / min ・ Air flow rate: 3.6 ml / min (containing water)
・ N ₂ O flow rate: 3.6 ml / min (containing water)
・ Reaction temperature: 100 ° C. ・ Reaction chamber oil amount: 100 ml
・ Iron naphthenate: 100ppm
・ Folding chamber temperature: 200 ℃ ~ 480 ℃
-Total test time: 114 minutes 2) Friction reduction effect Using a reciprocating sliding friction tester [SRV friction tester], with a frequency of 50 Hz, amplitude of 3 mm, load of 400 N, temperature of 110 ° C., test time of 25 minutes, friction coefficient Is used as an evaluation standard for the friction reduction effect.

Example 1
It contains 70.0% by weight of solvent refined oil A and 30.0% by weight of wax isomerized oil shown in Table 2, has a kinematic viscosity at 100 ° C. of 4.1 cSt, and GCD 480 ° C. residual heavy component is 7.5% by weight. % Mineral oil base oil was prepared. The content of GCD430 ° C. residual heavy component in the base oil was 35.5% by weight, of which GCD450 ° C. residual heavy component was 17.7% by weight. In the above base oil, based on the total weight of the lubricating oil composition, the sulfur content of oxymolybdenum dithiocarbamate is 500 ppm, the calcium salicylate is 3 wt%, the alkenyl succinimide is 3 wt%, the dibenzyl disulfide is the sulfur content is 500 ppm, and the zinc dithiophosphate As a phosphorus amount, 0.1% by weight was added, and other additives listed in Table 1 were added in the proportions shown in the same table to prepare a lubricating oil composition for an internal combustion engine. did. The trial oil 1 was subjected to a high temperature deposit prevention performance test (TEOST) and a friction test (SRV). The results are shown in Table 1. A high temperature deposit amount of 59.1 mg was obtained.

Example 2
Solvent refined oil A 30.0% by weight and wax isomerized oil 70.0% by weight are mixed, kinematic viscosity at 100 ° C. is 4.3 cSt, and GCD480 ° C. residual heavy component is contained 17.5% by weight. A mineral base oil was prepared. In the base oil, the residual heavy component of GCD430 ° C. was 49.5% by weight, and the residual heavy component of GCD450 ° C. was 33.3% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each additive shown in Table 1 to the base oil at a ratio shown in the same table, and designated as trial oil 2. The prototype oil 2 was subjected to a high temperature deposit prevention performance test (TEOST) and a friction test, and the measurement results are shown in Table 1. The high temperature deposit amount was further reduced to 48.6 mg.

Example 3
Mineral oil containing 85.0% by weight of solvent refined oil A, 7.5% by weight of poly-α-olefin A and 7.5% by weight of poly-α-olefin B and 4.0% by weight of GCD480 ° C. residual heavy component A system / synthetic system base oil was prepared. GCD430 ° C. residual heavy component in the base oil was 27.3% by weight, of which GCD450 ° C. residual heavy component was 10.1% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each additive shown in Table 1 to the base oil in the proportions shown in the same table, and designated as trial oil 3. Table 1 shows the high-temperature deposit amount and friction coefficient of the trial oil 3.

Example 4
Contains 70.0% by weight of solvent refined oil A, 15.0% by weight of poly-α-olefin A and 15% by weight of poly-α-olefin B, has a kinematic viscosity at 100 ° C. of 3.9 cSt, and remains at GCD 480 ° C. Heavy component 8.0% by weight of a mineral oil / synthetic oil mixed base oil was prepared. The GCD430 ° C. residual heavy component in the base oil was 29.7% by weight, and of these, the GCD450 ° C. residual heavy component was 14.3% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each of the additives shown in Table 1 to the above base oil in the proportions shown in Table 1, and was designated as trial oil 4. Table 1 shows the high-temperature deposit amount and friction coefficient of the trial oil 4.

Example 5
Solvent refined oil A 90.0% by weight and solvent refined oil E 10.0% by weight are mixed, a kinematic viscosity at 100 ° C. is 4.8 cSt, and GCD480 ° C. residual heavy component 9.0% by weight mineral oil system A base oil was prepared. The GCD430 ° C. residual heavy component was 32.5% by weight, and the GCD450 ° C. residual heavy component was 15.0% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each of the additives shown in Table 1 to the base oil in the proportions shown in Table 1, and was designated as trial oil 5. Table 1 shows the high-temperature deposit amount and friction coefficient of the trial oil 5.

Comparative Example 1
71.2% by weight of solvent refined oil A and 28.8% by weight of solvent refined oil B were mixed to prepare a base oil having a kinematic viscosity of 4.0 cSt at 100 ° C. This base oil contained no GCD480 ° C. residual heavy component. The GCD430 ° C. residual heavy component was 27.0% by weight, and the GCD450 ° C. residual heavy component was 6.6% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each of the additives shown in Table 1 to the base oil in the proportions shown in Table 1, and was designated as trial oil a. Table 1 shows the high-temperature deposit amount and friction coefficient of the trial oil a.

Comparative Example 2
Solvent refined oil A 30.0 wt% and hydrocracked oil 70.0 wt% were mixed to prepare a base oil having a kinematic viscosity of 3.9 cSt at 100 ° C. This base oil did not contain GCD 480 ° C. residual heavy components. The GCD430 ° C. residual heavy component was 10.8% by weight, and the GCD450 ° C. residual heavy component was 1.8% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each additive shown in Table 1 to the base oil at a ratio shown in the same table, and was designated as trial oil b. Table 1 shows the high-temperature deposit amount and friction coefficient of the trial oil b.

Comparative Example 3
71.8% by weight of solvent refined oil A and 29.2% by weight of solvent refined oil B were mixed to prepare a base oil having a kinematic viscosity of 4.0 cSt at 100 ° C. This base oil did not contain GCD480 ° C. residual heavy components. A lubricating oil composition for an internal combustion engine was prepared by adding each of the additives shown in Table 1 to the base oil in the proportions shown in Table 1, and was designated as trial oil c. The results of the performance evaluation are shown in Table 1.

Comparative Example 4
A mineral oil system in which 9.3% by weight of solvent refined oil C and 90.7% by weight of solvent refined oil D are mixed, kinematic viscosity at 100 ° C. is 4.0 cSt, and GCD480 ° C. residual heavy component 0.9% by weight A base oil was prepared. The GCD430 ° C. residual heavy component was 33.2% by weight, and the GCD450 ° C. residual heavy component was 15.6% by weight. A lubricating oil composition for an internal combustion engine was prepared by adding each additive shown in Table 1 to the base oil in the ratio shown in the same table, and designated as trial oil d. Table 1 shows the evaluation results of the high-temperature deposit amount and the friction coefficient.

Comparative Example 5
Mineral oil containing 70.0% by weight of solvent refined oil D and 30.0% by weight of poly-α-olefin A, kinematic viscosity at 100 ° C of 3.5 cSt, and GCD480 ° C residual heavy component 0.7% by weight A system / synthetic system base oil was prepared. The GCD430 ° C. residual heavy component was 25.2% by weight, and the GCD450 ° C. residual heavy component was 11.9% by weight. The additives shown in Table 1 were added to the base oil in the proportions shown in the same table to prepare a lubricating oil composition for an internal combustion engine. Table 1 shows the evaluation results of the high-temperature deposit amount and the friction coefficient. Although this base oil contained a heavy component remaining at 480 ° C. at GCD, since it was a small amount of 0.7% by weight, no effect on suppression of high-temperature deposit formation appeared.

Comparative Example 6
Mineral oil containing 30.0% by weight of solvent refined oil D and 70.0% by weight of poly-α-olefin A, having a kinematic viscosity at 100 ° C of 2.7 cSt, and a residual heavy component of 0.3% by weight of GCD480 ° C A system / synthetic system base oil was prepared. The GCD430 ° C. residual heavy component was 10.8% by weight, and the GCD450 ° C. residual heavy component was 5.1% by weight. The additives shown in Table 1 were added to the base oil in the proportions shown in the same table to prepare a lubricating oil composition for an internal combustion engine.

  Table 2 shows the mixed base materials used in the above Examples and Comparative Examples.

From the above examples and comparative examples, as shown in Examples 1 to 5, the base oil having 1% by weight or more of the GCD480 ° C. residual heavy component according to the present invention has a high temperature deposit amount (TEOST deposit) of ILSAC GF-2. (Amount) shows a remarkable effect of 60 mg or less. On the other hand, the base oil containing no GCD480 ° C. residual heavy component or less than 1% by weight has a very high high-temperature deposit amount as can be seen from Comparative Example 1 to Comparative Example 6, and satisfies the required value of ILSAC GF-2. It became clear that I was not satisfied. Further, the friction coefficients were all low enough to achieve low fuel consumption performance. From these results, it is clear that the contribution of the present invention is extremely large.

Claims (2)

  The lubricating base oil and the lubricating oil composition are based on the total weight of the organic molybdenum compound friction modifier in an amount of 200 ppm to 1500 ppm of molybdenum and calcium sulfonate and / or calcium salicylate in an amount of 1 wt% to 10 wt%. A lubricating oil composition for an internal combustion engine, wherein the lubricating base oil has a kinematic viscosity of 2 cSt to 13 cSt at 100 ° C., and is 480 ° C. or higher in a boiling range measured by gas chromatographic distillation based on the total weight of the lubricating base oil. 1 to 20% by weight of the heavy component and 27.3 to 49.5% by weight of the heavy component at 430 ° C. or higher in the boiling range measured by gas chromatographic distillation. A lubricating oil composition for an internal combustion engine. The lubricating oil composition for internal combustion engines according to claim 1, wherein the peroxide decomposer is further blended in an amount of 100 ppm to 4000 ppm as a sulfur amount.