JPH10147790A - Lubricating oil composition for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating oil composition excellent in the ability to inhibit a deposit from forming around the piston of an internal combustion engine, excellent in the ability to impart abrasion resistance to the respective sliding components, excellent in low-temperature properties and evaporation characteristics and advantageous in cost. SOLUTION: This composition is obtained by mixing a base oil having a kinematic viscosity of 3.0-12.0mm<2> /s (at 100 deg.C) and a heavy oil content of 5wt.% or above based on the base oil with 0.02-0.15wt.% (in terms of the amount of the nitrogen atoms), based on the entire weight of the composition, boron-free and/or boron-containing succinimide compounds having a number-average molecular weight (Mn) of 600-3,200 and a weight-average molecular weight (Mw) of 900-3,500 and an Mw/Mn ratio of 1.1-1.5 and 1.0-5.0wt.% based on the entire weight of the composition, overbased metal phenate having a base value of 100mgKOH/g or above. The base value ascribable to the overbased metal phenate should be 5-17mgKOH/g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lubricating oil composition for an internal combustion engine. More specifically, the present invention relates to a lubricating oil composition for an internal combustion engine that is excellent in suppressing deposits formed in a piston ring groove or the like of an internal combustion engine and has excellent wear resistance, and is particularly suitable as a diesel engine oil or a gasoline engine oil.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine, in addition to lubrication of various sliding parts such as a piston ring and a cylinder liner, a bearing of a crankshaft and a connecting rod, a valve mechanism including a cam and a valve lifter, A lubricating oil is used for the purpose of cooling the engine, cleanly dispersing combustion products, and preventing rust and corrosion.
As described above, lubricating oils for internal combustion engines are required to have various performances, and in recent years, advanced performances have been required in accordance with higher performance, higher output, and severe operating conditions of internal combustion engines. . Therefore, in order to satisfy such required performance, various additives such as an antiwear agent, a metal detergent, an ashless dispersant, and an antioxidant are blended in the lubricating oil for an internal combustion engine. Heretofore, a lubricating oil for an internal combustion engine, particularly a lubricating oil for a diesel engine has been used together with a metal detergent and an ashless dispersant as a detergent and dispersant. As the metal detergent, phenates, sulfonates, salicylates, phosphonates, and overbased products thereof of alkali metals and alkaline earth metals are generally used. On the other hand, as the ashless dispersant, polyalkenyl or polyalkylsuccinimide, polyalkenyl or polyalkylsuccinamide, polyalkenyl or polyalkylbenzylamine, and boron-treated products thereof are generally used. By the way, in recent years, high-performance engines have been required as automobile speeds have increased. Particularly in diesel engines, not only the peripheral parts of pistons but also sliding parts have become considerably hotter than conventional diesel engines. ing. Therefore, it is necessary to improve the cleanliness of the lubricating oil used (reduction of deposits) in the peripheral portion of the piston and to improve the wear resistance at high temperatures of each sliding portion. Conventionally, as a lubricating oil for diesel engines, for example, a solid impurity cohesive diesel engine oil having a composition obtained by adding calcium phenate, magnesium sulfonate and alkenyl succinimide to mineral oil or synthetic oil (Japanese Patent Publication No. 3-29839) And heavy-duty diesel lubricating oils containing an ashless dispersant, a sulfurized alkylphenol and an organic sulfur compound in a base oil (Japanese Patent Application Laid-Open No. 1-163294). However, with the combination of these additives, although the respective desired objects have been achieved, it is possible to sufficiently satisfy the above-described cleanliness at the peripheral portion of the piston and the abrasion resistance at high temperatures in each sliding portion. There is a problem that cannot be done. Furthermore, recently, a lubricating oil composition for diesel engines having a low ash content capable of exhibiting engine cleanliness and anti-deposit property has been proposed (Japanese Patent Laid-Open No. 7-1995).
102273 gazette). This lubricating oil composition contains 5 to 20% by weight of a boron-based ashless dispersant and a base number (perchloric acid method).
Is at least one selected from sulfonates, phenates and salicylates of 0 to 200 mgKOH / g.
A metal detergent of 0.01 to 30% by weight, wherein the amount of sulfated ash in the composition is 1.0% by weight or less;
And it has a boron content of 0.1% by weight or more. However, in this lubricating oil composition, the content of the boron-based ashless dispersant is too large, so that the amount of nitrogen increases, which adversely affects seal rubber, low-temperature viscosity characteristics, and the like, and is disadvantageous in terms of cost.

[0003]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is excellent in suppressing deposits formed around a piston such as a piston ring groove of an internal combustion engine, and has a high wear resistance in each sliding portion. Provide a lubricating oil composition for an internal combustion engine that is excellent in heat resistance, has little adverse effect on seal rubber, etc., has excellent low temperature characteristics and evaporation characteristics, and is advantageous in terms of cost, and is particularly suitable as a diesel engine oil or a gasoline engine oil. It was done for the purpose of doing.

[0004]

The present inventors have made intensive studies to develop a lubricating oil composition for an internal combustion engine having the above-mentioned preferable properties, and as a result, have found that a base oil having a viscosity in a specific range can be obtained. A boron-free succinimide compound and / or a boron-containing succinimide compound having a specific molecular weight and a molecular weight distribution are blended so that the amount of nitrogen is in a predetermined low range; The present inventors have found that a composition having a specific base number, in which phenate is blended in a predetermined ratio, can be suitable for the purpose, and based on this finding, have completed the present invention. That is, the present invention provides: (1) a kinematic viscosity at 100 ° C. of 3.0 to 12.0 mm ² / s
5% by weight of heavy oil based on lubricating base oil
In the base oil described above, (A) a number average molecular weight (Mn) of 600 to 3,200 and a weight average molecular weight (M
w) A boron-free succinimide compound and / or a boron-containing succinimide compound having a Mw / Mn ratio of 1.1 to 1.4 and a Mw / Mn ratio of from 0.02 to 0 .15% by weight, and
(B) 1.0 to 5.0% by weight of an overbased metal phenate having a base number of 100 mgKOH / g or more, wherein the base number derived from the overbased metal phenate is 5 to 17 mgKOH / g. A lubricating oil composition for an internal combustion engine. Furthermore, as a preferred embodiment of the present invention, (2) the component (A) is a boron-containing succinimide compound, and the amount of boron derived from the boron-containing succinimide compound in the entire composition is 0.005 to 0. No. 1% by weight
(1) The lubricating oil composition for an internal combustion engine according to the item (1), and (3) the item (1) or the item (1), further comprising 0.5 to 3.0% by weight of a neutral metal sulfonate having a base number of 50 mgKOH / g or less. The lubricating oil composition for an internal combustion engine according to the item (2) can be exemplified.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The lubricating oil composition of the present invention has a kinematic viscosity at 100 ° C. of 3.0 to 1 as a base oil.
It is necessary to use one in the range of 2.0 mm ² / s. If the kinematic viscosity is outside the above range, it is difficult to obtain a lubricating oil composition having excellent deposit resistance and wear resistance, and the object of the present invention cannot be achieved. The base oil used in the lubricating oil composition of the present invention is not particularly limited, and any one of a mineral base oil and a synthetic base oil, or
These mixed base oils can be mentioned. As the mineral base oil, for example, solvent purification, hydrocracking, hydrotreating, hydrorefining, lubricating oil fraction obtained by vacuum distillation of atmospheric distillation residue of paraffinic, intermediate base or naphthenic crude oil, Catalytic dewaxing, solvent dewaxing, mineral oil obtained by processing in a refining process such as clay treatment, after subjecting the vacuum distillation residue to solvent deasphalting, mineral oil obtained by processing the deasphalted oil in the above refining process, Alternatively, mineral oil or the like obtained by isomerization of a wax component or a mixed oil thereof can be used. In the above solvent purification, phenol, furfural,
Aromatic extraction solvents such as N-methyl-pyrrolidone are used, and liquefied propane, M
EK / toluene or the like is used. On the other hand, as synthetic base oils, for example, polyol esters such as poly-α-olefin oligomer, polybutene, alkylbenzene, trimethylolpropane ester, pentaerythritol ester, polyoxyalkylene glycol, polyoxyalkylene glycol ester, polyoxyalkylene glycol ether , Dibasic acid esters, phosphoric acid esters, silicone oils and the like. Each of these base oils may be used alone, or two or more may be used in combination. In the present invention, base oils are classified as follows according to kinematic viscosity at 100 ° C. That is,
Kinematic viscosity at 100 ° C. is 2.0mm ² /s~4.5mm ² / s
Light oil and a is group than, 4.5mm ² /s~11.0mm ² / s
Wood containing oil base oil is less than, 11.0mm ² / s~2,500.
The base oil of 0 mm ² / s is defined as heavy oil. In the lubricating oil composition of the present invention, the blending ratio of the heavy oil is 5% by weight or more, more preferably 10% by weight or more, even more preferably 16% by weight or more based on the lubricating base oil.

In the lubricating oil composition of the present invention, a succinimide compound containing no boron and / or a boron-containing succinimide compound is used as the component (A). Examples of the succinimide compound containing no boron include, for example, a compound represented by the general formula [1]:

Embedded image A monopolyalkenyl or polyalkylsuccinimide represented by the general formula [2]:

Embedded image Or a polyalkyl succinimide represented by the following formula: Further, as the boron-containing succinimide compound, for example, a monopolyalkenyl or polyalkylsuccinimide represented by the general formula [1] treated with a boron compound, or a general formula [2] Examples thereof include those obtained by treating bispolyalkenyl or polyalkylsuccinimide with a boron compound. In the general formulas [1] and [2], R
¹ , R ³ and R ⁴ are each an α-olefin oligomer residue having about 2 to 8 carbon atoms or a hydride thereof,
R ³ and R ⁴ may be the same or different. R ² , R ⁵ and R ⁶ are each an alkylene group having 2 to 4 carbon atoms, and R ⁵ and R ⁶ may be the same or different. m is an integer of 1 to 10, and n is an integer of 0 to 10.

In the present invention, the succinimide compound containing no boron as the component (A) is represented by the general formula [1]:
May be used, a bis-type compound represented by the general formula [2] may be used, or a mixture thereof may be used. Further, as the boron-containing succinimide compound of the component (A), a mono-type boron-treated product represented by the general formula [1] may be used, or a bis-type succinimide represented by the general formula [2] may be used. A boron-treated product may be used, or a mixture thereof may be used. In the present invention, the component (A) succinimide-based compound containing no boron and the boron-containing succinimide-based compound have a number average molecular weight (Mn) of 600 to 3,200 and a weight average molecular weight (Mw). ) Is in the range of 900 to 3,500,
Further, it is necessary that the Mw / Mn ratio is in the range of 1.1 to 1.4. If the Mn, Mw and Mw / Mn ratios are out of the above ranges, it is difficult to obtain a lubricating oil composition having excellent deposit resistance and wear resistance, and the object of the present invention cannot be achieved. In particular, the bis-type boron-containing succinimide-based compound has a high molecular weight (Mw of about 1,500 to 3,500, particularly 2,5
00 to 3,300) is preferable from the viewpoint of the effect of suppressing the amount of deposit. The polyalkenyl or polyalkylsuccinimide represented by the general formulas [1] and [2] is
It can be produced by reacting polyalkenyl succinic anhydride or a polyalkyl succinic anhydride, which is a hydride thereof, usually obtained by reacting a polyolefin with maleic anhydride with a polyalkylene polyamine. The mono- and bis-forms of the polyalkenyl or polyalkylsuccinimide can be produced by changing the reaction ratio between the polyalkenyl or polyalkylsuccinic anhydride and the polyalkylenepolyamine.

[0008] In the production of polyalkenyl or polyalkylsuccinimide, the polyolefin used as a raw material is selected from those obtained by polymerizing an α-olefin having about 2 to 8 carbon atoms and contains boron as a final product. The number average molecular weight (Mn), the weight average molecular weight (Mw) and the Mw / Mn ratio of the succinimide-based compound and the boron-containing succinimide-based compound that do not fall within the above ranges,
It is appropriately selected and used. The α-olefin forming the polyolefin may be used alone or in combination of two or more. Polybutene is particularly preferred as the polyolefin. On the other hand, examples of the polyalkylene polyamine include polyethylene polyamine, polypropylene polyamine, and polybutylene polyamine. Of these, polyethylene polyamine is preferable. Moreover, the boron-treated product of polyalkenyl or polyalkylsuccinimide can be produced by a conventional method. The content of boron in the boron-treated product is usually in the range of 0.1 to 5% by weight, and the preferable content is in the range of 0.1 to 2% by weight. In addition, the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the succinimide-based compound containing no boron and the boron-containing succinimide-based compound were measured by gel permeation chromatography (GPC) and calculated as polystyrene. Can be obtained as the value of

Further, the boron-containing succinimide compound and the boron-free succinimide compound may be used as a mixture. The mixing ratio of the boron-containing succinimide compound is preferably 25% by weight or more and the boron-free succinimide-based compound is preferably 75% by weight or less. If the mixing ratio of the boron-containing succinimide compound is less than 25% by weight, the dispersibility of the sludge may be insufficient, and the abrasion resistance may be adversely affected, and the object of the present invention is sufficiently achieved. May not be possible. In the lubricating oil composition of the present invention, the component (A) must be contained in an amount of 0.02 to 0.15% by weight, preferably 0.1% by weight, based on the total amount of the composition.
0.5 to 0.13% by weight. The content of this nitrogen is 0.0
If the amount is less than 2% by weight, the dispersibility of the sludge is insufficient and the object of the present invention cannot be achieved. If the amount exceeds 0.15% by weight, the effect is not improved for the amount. And the low-temperature viscosity deteriorates, and it is economically disadvantageous.

Next, in the lubricating oil composition of the present invention,
As the component (B), an overbased metal phenate having a base number of 100 mgKOH / g or more is used. If the base number of the overbased metal phenate is less than 100 mgKOH / g, a lubricating oil composition excellent in deposit resistance and antioxidant action cannot be obtained,
The object of the present invention cannot be achieved. From the viewpoint of the effect, the preferred base number of the overbased metal phenate is 100 to 450.
It is in the range of mg KOH / g, and particularly preferably in the range of 120 to 350 mg KOH / g. Such an overbased metal phenate is not particularly limited as long as the base number is in the above range, and conventionally known ones can be used. For example,
Alkaline earth metal salts of alkyl phenols and alkyl phenol sulfides, and those obtained by further overbasing these with alkali earth metal hydroxides or oxides and carbon dioxide are preferred. Here, examples of the alkaline earth metal salt include a calcium salt, a magnesium salt, a barium salt and the like, and a calcium salt is particularly preferable. In the present invention, the overbased metal phenate of the component (B) may be used singly or in combination of two or more, and the content thereof is 1.0 based on the total amount of the composition. ~ 5.0% by weight. If the content is less than 1.0% by weight, a lubricating oil composition having excellent deposit resistance and antioxidant action cannot be obtained, and the object of the present invention cannot be achieved. If the content exceeds 5.0% by weight, The effect is not improved for the amount, but rather the deposit resistance is reduced, the ash content is increased, and the ash is deposited in the combustion chamber, adversely affecting the combustibility.

In the lubricating oil composition of the present invention, if necessary, the above-mentioned lubricating oil composition may be used in order to further improve the deposit resistance.
A neutral metal sulfonate having a base number of 50 mgKOH / g or less may be blended with the component (B). The neutral metal sulfonate improves the deposit resistance and, in addition, further improves the rust resistance. If the neutral metal sulfonate has a base number of more than 50 mgKOH / g, the effect of blending the neutral metal sulfonate is not sufficiently exhibited. As the neutral metal sulfonate, those having a base number within the above range are preferable, and there is no particular limitation, and conventionally known ones can be used. For example, calcium salts of alkyl-substituted aromatic compound sulfonates, magnesium salts,
Barium salts and the like can be mentioned, and among them, calcium salts are particularly preferable. In the present invention, one kind of the neutral metal sulfonate may be used, or two or more kinds thereof may be used in combination. The content thereof is 0.5 to 3.0% by weight based on the total amount of the composition. Is preferably within the range. 0.5% by weight of neutral metal sulfonate
If the amount is less than 30% by weight, the effect of blending the neutral metal sulfonate cannot be sufficiently exerted. If the amount exceeds 3.0% by weight, the effect is not improved for the amount. Increases and accumulates in the combustion chamber, adversely affecting flammability. The lubricating oil composition of the present invention thus prepared needs to have a base number derived from an overbased metal phenate in the range of 5 to 17 mgKOH / g. In particular, it is preferably in the range of 8 to 13 mgKOH / g from the viewpoint of deposit control. When the base number is out of the above range, the deposit resistance and the antioxidant effect are reduced, and the object of the present invention cannot be achieved. In the present invention, the base numbers of the overbased metal phenate and the neutral metal sulfonate can be both measured by a hydrochloric acid method (based on JIS K2501).

In the lubricating oil composition of the present invention, when the compounding ratio of the heavy oil in the lubricating base oil is 5% by weight or more and the boron-containing succinimide compound is compounded as the component (A), It is particularly preferable that the compounding ratio of heavy oil is 5 to 25% by weight, the compounding ratio of medium oil is 10 to 40% by weight, and the compounding ratio of light oil is 35 to 74% by weight. When each of the heavy oil, the medium oil and the light oil is blended in the above proportions, the lubricating oil composition is particularly excellent in low-temperature viscosity and evaporation characteristics in addition to deposit resistance and abrasion resistance. It will be. In the lubricating oil composition of the present invention,
When the component (A) is a boron-containing succinimide compound, the amount of boron derived from the boron-containing succinimide compound is preferably 0.005 to 0.1% by weight in the whole composition. . When the amount of boron derived from the boron-containing succinimide-based compound is 0.005% by weight or more, the effect of dispersing the sludge is sufficiently exhibited. When the amount of boron derived from the boron-containing succinimide-based compound exceeds 0.1% by weight, the effect is not improved for the amount, and the seal rubber and low-temperature viscosity characteristics are adversely affected.

The lubricating oil composition of the present invention may contain, if desired, other additives conventionally used in lubricating oils for internal combustion engines, for example, an antiwear agent, a friction agent, as long as the object of the present invention is not impaired. Adjusters, antioxidants, viscosity index improvers, pour point depressants, rust inhibitors, corrosion inhibitors, defoamers and the like can be added as appropriate. Examples of the antiwear agent include metal dithiophosphates (Zn, Pb, Sb, Mo, etc.), metal dithiocarbamates (Zn, etc.), sulfur compounds, phosphate esters, phosphite esters, and phosphate ester amine salts. And amine salts of phosphites, which are usually used in a proportion of 0.05 to 5% by weight. Among them, zinc dithiophosphate is preferable, and is represented by the following general formula [3].

Embedded image In the above general formula [3], R ⁷ and R ⁸ are a hydrogen atom or a hydrocarbon group having 1 to 26 carbon atoms, and the hydrocarbon group is a primary (primary) or second hydrocarbon group having 1 to 26 carbon atoms.
A (secondary) alkyl group; an alkenyl group having 2 to 26 carbon atoms; a cycloalkyl group having 3 to 26 carbon atoms; an aryl group, an alkylaryl group or an arylalkyl group having 3 to 26 carbon atoms; It is a hydrocarbon group containing a hydroxyl group or a carboxyl group. Preferably an alkyl group having 2 to 12 carbon atoms, 8 carbon atoms
To 18 cycloalkyl groups and C8 to C18 alkylaryl groups, which may be the same or different from each other. Further, a mixture of a primary zinc dithiophosphate and a secondary zinc dithiophosphate is preferable, and the mixing ratio thereof is 2%.
The ratio is preferably from 0:80 to 80:20 (weight ratio). It is preferable that the amount of phosphorus derived from zinc dithiophosphate is 0.05 to 0.20% by weight in the whole composition. If the amount of phosphorus derived from zinc dithiophosphate in the whole composition is less than 0.05% by weight, satisfactory anti-wear properties may not be obtained under high-temperature and low-speed operation conditions. The amount of phosphorus derived from zinc dithiophosphate in the whole composition is 0.20
If the amount exceeds 10% by weight, no improvement in the wear resistance effect is recognized for the amount.

Examples of the friction modifier include molybdenum-based, amine-based, and phosphate-based agents, and these are usually used at a ratio of 0.05 to 5% by weight. Examples of the antioxidant include amine antioxidants such as alkylated diphenylamine, phenyl-α-naphthylamine, and alkylated-α-naphthylamine, and 2,6-di-t-.
Butyl-4-methylphenol, 4,4'-methylenebis
(2,6-di-t-butylphenol), 4,4'-bis
(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'-thiobis (2-methyl-6-t-butylphenol), 4,4'-thiobis (3-
Phenol-based antioxidants such as methyl-6-t-butylphenol) and 2,2′-thiobis (4-methyl-6-t-butylphenol). These are usually used at a ratio of 0.05 to 2% by weight. Examples of the viscosity index improver include polymethacrylates, olefin copolymers (polyisobutylene, ethylene-propylene copolymers, styrene-butadiene hydrogenated copolymers), and the like. In particular, a dispersion type olefin copolymer (ethylene-propylene copolymer) having a polymer amount of 0.1 to 1% by weight in oil is preferable from the viewpoint of the effect of suppressing the amount of deposit. As the pour point depressant, for example, polymethacrylate and the like, as the rust inhibitor, for example, alkenyl succinic acid and its partial ester, etc., as the corrosion inhibitor, for example, benzotriazole, benzimidazole, thiadiazole and the like, Examples of the antifoaming agent include dimethylpolysiloxane, polyacrylate, and the like, and these can be appropriately added.

[0015]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In addition, the amount of deposit formation, low-temperature viscosity, and evaporation loss were determined according to the following methods. 1. Deposit generation amount Simulating the use condition of lubricating oil in a diesel engine, a mixture of test oil and 6% by weight of commercially available carbon black was placed on a heated aluminum panel from the tip of a micro syringe at a speed of 1.0 g / hr. Drip. The oil carbonizes on the slanted panels to form a deposit. After a test for 3 hours under the conditions of a panel inclination of 8 ° and a panel temperature of 310 ° C., the oil remaining in the generated deposit is extracted with petroleum ether, and the amount of deposit generated is determined from the panel weight difference before and after the test. FIG. 1 shows a schematic diagram of a deposit generation amount evaluation apparatus. 2. Low Temperature Viscosity Measured at -20 ° C in accordance with JIS K 2010 "Method of testing apparent viscosity of engine oil at -40 ° C to 0 ° C using cold cracking simulator". 3. Evaporation loss It was measured in accordance with JPI-5S-41-93 "Engine oil evaporation test method". The following were used as the base oil and the additives. (1) Base oil BO-1: 86% by weight of solvent-refined mineral oil base oil 100N (100 ° C. kinematic viscosity: 4.4 mm ² / s) and solvent-refined mineral oil base oil 65
0N (100 ° C. kinematic viscosity: 13.3 mm ² / s) 14% by weight, 100 ° C. kinematic viscosity: 5.1 mm ² / s BO-2; Solvent refined mineral base oil 100N (100 ° C. kinematic viscosity: 4. 4 mm ² / s) 80% by weight and solvent refined mineral base oil 65
0N (100 ° C. kinematic viscosity: 13.3 mm ² / s) mixture with 20% by weight, 100 ° C. kinematic viscosity: 5.3 mm ² / s BO-3; Solvent refined mineral base oil 150 N (100 ° C. kinematic viscosity: 4. 7 mm ² / s) 84% by weight and solvent refined mineral base oil 65
0N (100 ° C. kinematic viscosity: 13.3 mm ² / s) a mixture of 16 wt%, 100 ° C. kinematic ^{viscosity: 5.4mm 2 / s BO-4} ; hydrocracked mineral base oil 100 N (100 ° C. kinematic viscosity: 4 .1 mm ² / s) 86% by weight and hydrocracked mineral base oil 6
50 N (100 ° C. kinematic viscosity: 13.0 mm ² / s) 14% by weight
Kinematic viscosity at 100 ° C .: 5.0 mm ² / s BO-5; 80% by weight of solvent-refined mineral oil base oil 150N (100 ° C. kinematic viscosity: 4.7 mm ² / s) and solvent-refined mineral oil base oil 65
0N (100 ° C. kinematic viscosity: 13.3 mm ² / s) mixture with 20% by weight, 100 ° C. kinematic viscosity: 5.6 mm ² / s BO-6; Solvent refined mineral oil base oil 150 N (100 ° C. kinematic viscosity: 4. 7 mm ² / s) 75% by weight and solvent refined mineral base oil 65
0N (100 ° C. kinematic viscosity: 13.3 mm ² / s) mixture with 25% by weight, 100 ° C. kinematic viscosity: 5.9 mm ² / s BO-7; Solvent refined mineral oil base oil 100N (100 ° C. kinematic viscosity: 4. 4 mm ² / s) 68% by weight and solvent refined mineral base oil 15
0N (100 ° C. kinematic viscosity: 4.7mm ² / s) 16 wt% and a solvent refined mineral base oil 650 N (100 ° C. kinematic viscosity: 13.3 mm ²
/ S) mixture with 16% by weight, kinematic viscosity at 100 ° C .: 5.2 m
m ² / s BO-8; solvent refined mineral base oil 100 N (100 ° C. kinematic viscosity: 4.4mm ² / s) 64 wt% and a solvent refined mineral base oils 15
0N (100 ° C. kinematic viscosity: 4.7mm ² / s) 16 wt% and a solvent refined mineral base oil 650 N (100 ° C. kinematic viscosity: 13.3 mm ²
/ S) mixture with 20% by weight, kinematic viscosity at 100 ° C .: 5.4 m
m ² / s BO-9; solvent refined mineral base oil 100 N (100 ° C. kinematic viscosity: 4.4mm ² / s) 63 wt% and a solvent refined mineral base oils 15
0N (100 ° C. kinematic viscosity: 4.7mm ² / s) 12 wt% and a solvent refined mineral base oil 650 N (100 ° C. kinematic viscosity: 13.3 mm ²
/ S) mixture with 25% by weight, kinematic viscosity at 100 ° C .: 5.6 m
m ² / s BO-10; solvent refined mineral base oil 650 N (100 ° C. kinematic viscosity: 13.3mm ² / s) 25 wt% and a wax isomerized oil (100 ° C. kinematic viscosity: 4.5mm ² / s) 75 Weight % Kinematic viscosity: 5.6 mm ² / s BO-11; 90% by weight of solvent-refined mineral oil base oil 100N (100 ° C. kinematic viscosity: 4.4 mm ² / s) and solvent-refined mineral oil base oil 65
0N (100 ° C. kinematic viscosity: 13.3 mm ² / s) a mixture of 10 wt%, 100 ° C. kinematic ^{viscosity: 4.7mm 2 / s BO-12} ; hydrocracked mineral base oil 100 N (100 ° C. kinematic viscosity: 4 0.1 mm ² / s) 95% by weight of ethylene propylene copolymer (100 ° C. kinematic viscosity: 600 mm ² / s) 5% by weight, 100 ° C. kinematic viscosity: 4.8 mm ² / s BO-13; Solvent refined mineral oil base 96% by weight of oil 150N (100 ° C kinematic viscosity: 4.7 mm ² / s) and solvent-refined mineral base oil 65
0N (100 ° C. kinematic viscosity: 13.3mm ² / s) 4 mixture of wt%, 100 ° C. kinematic viscosity: 4.7mm ² / s ⁽²⁾ succinimide compound A-1; Boron 0.2 wt% Containing succinimide compound, Mn: 2,380, Mw: 2,990, Mw / Mn: 1.
26A-2; succinimide compound containing 0.3% by weight of boron, Mn: 3,050, Mw: 3,300, Mw / Mn: 1.
08 A-3; succinimide compound containing 0.1% by weight of boron, Mn: 2,310, Mw: 4,670, Mw / Mn: 2.
02 A-4; a succinimide compound containing no boron,
Mn: 1,480, Mw: 1,820, Mw / Mn: 1.23 A-5; a succinimide compound containing no boron
Mn: 1,750, Mw: 2,100, Mw / Mn: 1.20 A-6; succinimide compound containing no boron
Mn: 2,650, Mw: 2,800, Mw / Mn: 1.06 A-7; succinimide compound containing no boron,
Mn: 3,030, Mw: 5,290, Mw / Mn: 1.75 A-8; succinimide compound containing no boron
Mn: 920, Mw: 1,100, Mw / Mn: 1.20 (3) Metal phenate, metal sulfonate B-1; calcium phenate, base number: 280 mg KOH
/ G B-2; calcium sulfonate, base number: 20 mg KO
H / g B-3; calcium sulfonate, base number: 300 mg
KOH / g B-4; calcium phenate, base number: 50 mg KOH /
g Example 1 Solvent refined mineral base oil 100N (Kinematic viscosity at 100 ° C:
86% by weight of a 4.4 mm ² / s) solvent-refined mineral base oil 650N
(Kinematic viscosity at 100 ℃: 13.3mm ² / s) in a mixture of 14 wt%, a kinematic viscosity at 100 ° C. 5.1 mm ² /
The lubricant base oil (BO-1) contains 0.2% by weight of boron as an ashless dispersant, Mn: 2,380, Mw:
2,990, 6.0% by weight of a succinimide compound (A-1) having a Mw / Mn of 1.26, and calcium phenate (B-1) having a base number of 280 mgKOH / g as a metal detergent. And a 50:50 (weight ratio) mixture of a primary zinc dialkyldithiophosphate having 4 to 8 carbon atoms and a secondary zinc dialkyldithiophosphate having 3 to 6 carbon atoms as an antiwear agent. 1.2% by weight, 0.5% by weight of diphenylamine as an antioxidant, 5.0% by weight of an ethylene-propylene copolymer as a viscosity index improver (polymer amount in oil 0.5% by weight), pour point A lubricating oil composition for an internal combustion engine was prepared by blending 0.2% by weight of polymethacrylate as a depressant and 0.01% by weight of dimethylpolysiloxane as an antifoaming agent. The lubricating oil composition had a metal detergent derived base number of 10.0 mg KOH / g, a nitrogen content of 0.06% by weight, and a boron content of 0.0.
1% by weight and the phosphorus content was 0.12% by weight.
The amount of deposit generated from the lubricating oil composition for an internal combustion engine is 12
1 mg, and the low temperature viscosity was 2,800 mp · s. Examples 2 to 12, 21 to 24 In the same manner as in Example 1, using the type of base oil shown in Table 1, the boron-containing succinimide compound of the type and amount shown in Table 1, containing no boron A succinimide compound, an overbased metal phenate, and a neutral metal sulfonate are blended, and a primary dialkyldithiophosphate having 4 to 8 carbon atoms and a secondary dialkyldithiophosphate having 3 to 6 carbon atoms are used as an antiwear agent. 1.2% by weight of a 50:50 mixture of zinc by weight, 0.5% by weight of diphenylamine as an antioxidant, and 5.0% by weight of an ethylene-propylene copolymer as a viscosity index improver (polymer in oil) 0.5% by weight) and 0.2 of polymethacrylate as a pour point depressant.
% By weight and dimethylpolysiloxane as an antifoaming agent in an amount of 0.1%.
By blending at 01% by weight, 14 types of lubricating oil compositions for internal combustion engines were prepared. The base number (derived from the metal detergent), nitrogen content, boron content, phosphorus content, deposit generation amount, and low-temperature viscosity of each additive of these lubricating oil compositions were determined. Table 1 shows the results. Example 13 Solvent-refined mineral base oil 150N (kinematic viscosity at 100 ° C .: 4.7 mm ²⁾
/ S) 84 wt% and solvent refined mineral base oil 650 N (100
° C kinematic viscosity: 13.3 mm ² / s) in a mixture with 16% by weight,
A lubricating base oil (BO) having a kinematic viscosity of 5.4 mm ² / s at 100 ° C.
-3) As ashless dispersants, Mn: 1,750, Mw:
2,100, Mw / Mn: 10.0% by weight of a boron-free succinimide-based compound (A-5) having a concentration of 1.20, and calcium phenate having a base number of 280 mgKOH / g as a metal detergent ( B-1) was added in an amount of 3.6% by weight, and a 50:50 mixture of a primary zinc dialkyldithiophosphate having 4 to 8 carbon atoms and a secondary zinc dialkyldithiophosphate having 3 to 6 carbon atoms was used as an antiwear agent. (Weight ratio): 1.2% by weight of the mixture and 0.2% of diphenylamine as an antioxidant.
5% by weight, 5.0% by weight of ethylene-propylene copolymer (0.5% by weight of polymer in oil) as a viscosity index improver, and 0.2% of polymethacrylate as a pour point depressant.
% By weight and dimethylpolysiloxane as an antifoaming agent in an amount of 0.1%.
By blending at 01% by weight, a lubricating oil composition for an internal combustion engine was prepared. The lubricating oil composition has a base number derived from a metal detergent of 1
It was 0.0 mg KOH / g and the nitrogen content was 0.1% by weight. The lubricating oil composition for an internal combustion engine had a deposit amount of 90 mg, a low temperature viscosity of 3,800 mps, and an evaporation loss (NOACK) of 14.1 mass%. Examples 14 to 20 In the same manner as in Example 13, using a base oil of the type shown in Table 1 and a boron-containing succinimide compound of the type and amount shown in Table 1, a boron-free succinimide compound A compound, an overbased metal phenate and a neutral metal sulfonate, and 50% of a primary zinc dialkyldithiophosphate having 4 to 8 carbon atoms and a secondary zinc dialkyldithiophosphate having 3 to 6 carbon atoms as an antiwear agent. : 50 (weight ratio) 1.2% by weight of a mixture, 0.5% by weight of diphenylamine as an antioxidant, 5.0% by weight of an ethylene-propylene copolymer as a viscosity index improver (polymer amount in oil: 0.1%). 5% by weight) and polymethacrylate as a pour point depressant in an amount of 0.1%.
By mixing 2% by weight and 0.01% by weight of dimethylpolysiloxane as an antifoaming agent, seven types of lubricating oil compositions for internal combustion engines were prepared. Base values (derived from metal detergents), nitrogen content, boron content, phosphorus content, amount of deposit, low-temperature viscosity and evaporation loss of each additive of these lubricating oil compositions were determined. Table 1 shows the results.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

[0019]

[Table 4]

[Note] 1) Base number derived from overbased metal phenate or neutral metal sulfonate 2) Boron-containing succinimide compound, nitrogen content derived from boron-free succinimide compound 3) Boron-containing Boron content derived from succinimide-based compound Comparative Examples 1 to 19 In the same manner as in Example 1, using a base oil of the type shown in Table 2, boron-containing succinimide of the type and amount shown in Table 2, A boron-free succinimide, an overbased metal phenate, and a neutral metal sulfonate are blended, and a C4-8 primary zinc dialkyldithiophosphate and a C3-6 secondary zinc are used as antiwear agents. 1.2% by weight of a 50:50 (weight ratio) mixture of zinc dialkyldithiophosphate, 0.5% by weight of diphenylamine as an antioxidant, and ethyl as a viscosity index improver. A blend of 5.0% by weight of a propylene copolymer, 0.2% by weight of a polymethacrylate as a pour point depressant and 0.01% by weight of dimethylpolysiloxane as an antifoaming agent is used for 22 kinds of internal combustion engines. A lubricating oil composition was prepared. Base value (derived from metal detergent) derived from each additive of these lubricating oil compositions, nitrogen content,
The boron content and the amount of deposit generated were determined. Table 2 shows the results.

[0021]

[Table 5]

[0022]

[Table 6]

[0023]

[Table 7]

[0024]

[Table 8]

[Note] 1) Base number derived from metal phenate and metal sulfonate 2) Boron-containing succinimide compound, nitrogen content derived from succinimide compound not containing boron 3) Boron-containing succinimide compound Based on the results in Table 1, the lubricating oil composition for an internal combustion engine of the present invention has a low amount of deposit formation of about 30 to 150 mg, and particularly low viscosity and evaporation for Examples 13 to 20. It can be seen that the loss is also excellent. In contrast,
As shown in Table 2, Comparative Example 1 and Mw in which the nitrogen content derived from the boron-containing succinimide compound was too low.
/ Mn is small and the lubricating oil composition of Comparative Example 2 having too much nitrogen content has a large amount of deposits. Comparative Example 3, Mn of Mn of boron-containing succinimide compound is too large
The lubricating oil composition of Comparative Example 4 in which Mw and Mw / Mn are too large has a large amount of deposit. Comparative Example 5 where the base number of the composition is too small and Comparative Example 6 where the base number of the composition is too large
The lubricating oil composition has a large amount of deposit. The lubricating oil compositions of Comparative Examples 7 and 8 in which a metal sulfonate was blended in place of the overbased metal phenate have a large amount of deposit. When the heavy oil (base oil) is 16% by weight or more, the lubricating oil composition of Comparative Example 9 in which the nitrogen content derived from the boron-containing succinimide-based compound is too small has a large amount of deposit. The lubricating oil composition of Comparative Example 10 in which the base number of the metal phenate is too small has a large amount of deposit.
The lubricating oil compositions of Comparative Examples 11 to 15 in which Mn, Mw and Mw / Mn of the succinimide-based compound are too large have a large amount of deposit. The lubricating oil composition of Comparative Example 16 in which Mw / Mn of the succinimide compound is too small has a large amount of deposit. Mn, Mw and Mw of succinimide compounds
The lubricating oil compositions of Comparative Examples 17 and 18 having too high / Mn have large amounts of deposits. The lubricating oil composition of Comparative Example 19, in which the proportion of heavy oil was small, had a large amount of deposit.

[0026]

Industrial Applicability The lubricating oil composition for an internal combustion engine of the present invention is excellent in suppressing deposits formed around a piston such as a piston ring groove of an internal combustion engine, and is excellent in wear resistance in each sliding portion, and has a low temperature. Low viscosity, excellent evaporation loss, and low nitrogen content derived from boron-containing succinimide and boron-free succinimide. It is suitable as engine oil or gasoline engine oil.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a deposit generation amount evaluation apparatus.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10N 20:02 20:04 30:04 30:06 40:25 (72) Inventor Katsumi Yamamoto Kazuto Nishitsurugaoka, Oimachi, Iruma-gun, Saitama Chome 3-1, Tonen Co., Ltd. (72) Inventor Mitsuru Yanaka 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Fumio Ueda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Inside the corporation

Claims (1)

[Claims] 1. A kinematic viscosity at 100 ° C. of 3.0 to 12.0.
mm ² / s, and the mixing ratio of heavy oil is 5 based on lubricating base oil.
(A) a number average molecular weight (Mn) of from 600 to 3,200, a weight average molecular weight (Mw) of from 900 to 3,500, and an Mw / Mn ratio of 1.1 based on the total weight of the composition. ~ 1.
4. a succinimide compound containing no boron and / or
Or, a boron-containing succinimide compound is blended so that the amount of nitrogen is 0.02 to 0.15% by weight, and
(B) 1.0 to 5.0% by weight of an overbased metal phenate having a base number of 100 mgKOH / g or more, wherein the base number derived from the overbased metal phenate is 5 to 17 mgKOH / g. A lubricating oil composition for an internal combustion engine.