WO2017170769A1 - Lubricant oil composition for internal combustion engines - Google Patents

Abstract

The present invention minimizes negative effects on an exhaust gas purification device and achieves excellent energy efficiency while inhibiting an increase in viscosity of a lubricant oil when biofuel gets mixed therein, by using a lubricant oil composition for internal combustion engines, which comprises: a base oil; (A) at least one component selected from (A1) alkenyl or alkyl succinic acid monoimide and boron derivatives thereof and (A2) alkenyl or alkyl succinic acid bisimide and boron derivatives thereof; (B) at least one component selected from binuclear and trinuclear organomolybdenum compounds; (C) superbasic sodium sulfonate; and (D) at least one component selected from superbasic calcium salicylate (D1) and superbasic calcium phenate (D2), wherein the contained amounts of components (A) to (C) and the contained amount ratio between component (A1) and component (A2) are respectively specified to fall within prescribed ranges, while the contained amount of sulfuric acid ash is specified to be 0.8 mass% or less.

Description

Lubricating oil composition for internal combustion engines

The present invention relates to a lubricating oil composition for an internal combustion engine, for example, a lubricating oil composition for an internal combustion engine that is driven by burning a fuel containing biofuel.

Conventionally, in order to suppress the deterioration of the lubricating oil, it is widely known to add a metallic detergent, an ashless dispersant, an antioxidant, etc. to the lubricating oil. For example, in Patent Document 1, a succinic monoimide boron derivative and succinic acid bisimide are blended as a ashless dispersant in a lubricating oil for an internal combustion engine, particularly a diesel engine, and a predetermined amount of a specific antioxidant is blended. Thus, it is disclosed that the deterioration of the lubricating oil is prevented.

Further, in diesel engines, as a means for removing and collecting exhaust gas components such as particulate matter and NO _X, it is known to mount such an exhaust purifying device as a diesel particulate filter (DPF) . In an internal combustion engine equipped with an exhaust gas purification device, it is desired to reduce the ash content of the lubricating oil in order to prevent clogging of the filter, deterioration of the performance of the catalyst in the exhaust gas purification device, and the like.
Further, in recent years, so-called biofuels have attracted attention as fuels used in automobiles from the viewpoint of reducing carbon dioxide, which is a main factor of global warming. For example, biodiesel fuels are sometimes used. Biofuels can be mixed in lubricating oils in internal combustion engines, but if they are mixed, they tend to accumulate in lubricating oils due to their chemical structure, and polar compounds are generated when they are degraded and decomposed. There is a concern that this may be reduced.

Therefore, conventionally, as disclosed in, for example, Patent Document 2, in order to improve the cleanliness of the engine when using biodiesel fuel while suppressing the adverse effect on the exhaust gas purification device, the mass ratio of boron and nitrogen There is known a lubricating oil in which a boron derivative of a succinimide compound in which is adjusted to a predetermined range and an alkaline earth metal detergent are blended and the sulfated ash content is adjusted to 1.1 mass% or less.

Japanese Patent No. 4806528 Japanese Patent No. 5313879

However, when the biofuel is mixed in the lubricating oil, not only the cleanliness is deteriorated but also the viscosity of the lubricating oil is increased, which may cause problems such as shortening the replacement period of the lubricating oil.
In addition, in order to reduce the coefficient of friction between metals and improve fuel efficiency, a lubricating compound may be blended with a molybdenum compound as a friction modifier. When a molybdenum compound is blended, the viscosity of the lubricating oil increases. May progress more. Therefore, when biofuel is mixed in the lubricating oil, it is difficult to suppress an increase in the viscosity of the lubricating oil while improving fuel economy.

Furthermore, in the diesel engine, as described above, in order to reduce the adverse effect on the exhaust gas purification device, it is desired to reduce the ash content (ie, sulfate ash content) of the lubricating oil. However, when the ash content is lowered, the blending amount of the friction modifier and the metal detergent is limited, and it becomes difficult to lower the intermetallic friction coefficient or to improve the oxidation stability. For this reason, it becomes difficult to improve fuel economy, and it is also difficult to suppress an increase in the viscosity of the lubricating oil that occurs when biofuel is mixed.

The present invention has been made in view of the above circumstances, and the problem of the present invention is that biofuels are mixed in lubricating oil while reducing adverse effects on the exhaust gas purification device and improving fuel economy. Even in such a case, it is an object to provide a lubricating oil composition for an internal combustion engine that can suppress an increase in the viscosity of the lubricating oil and prolong the replacement period of the lubricating oil.

As a result of intensive studies, the present inventors have blended the following components (A) to (D) into the lubricating oil composition, and the contents of these components so that the sulfated ash content is 0.8% by mass or less. The inventors have found that the above problems can be solved by setting the content ratio within a predetermined range, and have completed the following present invention. That is, this invention provides the following lubricating oil composition for internal combustion engines, and its manufacturing method. (1) base oil;
At least one succinimide compound (A) selected from the group consisting of alkenyl or alkyl succinic acid monoimide and its boron derivative (A1), and alkenyl or alkyl succinic acid bisimide and its boron derivative (A2);
At least one molybdenum-based compound (B) selected from the group consisting of a dinuclear organic molybdenum compound (B1) and a trinuclear organic molybdenum compound (B2);
Overbased sodium sulfonate (C);
Including at least one overbased calcium-based detergent (D) selected from the group consisting of overbased calcium salicylate (D1) and overbased calcium phenate (D2);
The content of the component (A) is 550 mass ppm or more in terms of nitrogen atoms, the content of the component (B) is 200 mass ppm to 600 mass ppm in terms of molybdenum atoms, and the component (C). Content is 250 mass ppm or more in terms of sodium atom,
The ratio [(A1 / A2)] of the content of the component (A1) in terms of nitrogen atom and the content of the component (A2) in terms of nitrogen atom is 0 or more and 0.3 or less, and the sulfated ash content is The lubricating oil composition for an internal combustion engine, which is 0.8% by mass or less.
(2) To base oil,
At least one succinimide compound (A) selected from the group consisting of alkenyl or alkyl succinic acid monoimide and its boron derivative (A1), and alkenyl or alkyl succinic acid bisimide and its boron derivative (A2),
At least one molybdenum-based compound (B) selected from the group consisting of a dinuclear organic molybdenum compound (B1) and a trinuclear organic molybdenum compound (B2);
Overbased sodium sulfonate (C), and at least one overbased calcium detergent (D) selected from the group consisting of overbased calcium salicylate (D1) and overbased calcium phenate (D2) A method for producing a lubricating oil composition for an internal combustion engine, wherein a lubricating oil composition is obtained by blending
The blending amount of the component (A) on the basis of the total amount of the lubricating oil composition is 550 mass ppm or more in terms of nitrogen atoms, the blending amount of the component (B) is 200 to 600 ppm in terms of molybdenum atoms, and the component (C) The blending amount is 250 mass ppm or more in terms of sodium atom,
The ratio [(A1 / A2)] of the blending amount of the component (A1) in terms of nitrogen atoms and the blending amount of the component (A2) in terms of nitrogen atoms is 0 or more and 0.3 or less, and the sulfated ash content is The manufacturing method of the lubricating oil composition for internal combustion engines which is 0.8 mass% or less.

In the present invention, the adverse effect on the exhaust gas purification device is reduced and the fuel efficiency is excellent, and even when biofuel is mixed in the lubricating oil, the increase in the viscosity of the lubricating oil is suppressed, and the lubricating oil A lubricating oil composition for an internal combustion engine capable of extending the replacement period is provided.

Hereinafter, embodiments of the present invention will be described in detail.
A lubricating oil composition for internal combustion engines according to an embodiment of the present invention (hereinafter, also simply referred to as “lubricating oil composition”) includes a base oil, a succinimide compound (A), and a molybdenum compound (B). And an overbased sodium sulfonate (C) and an overbased calcium detergent (D). Hereinafter, each component will be described in detail. The numerical values “above” and “below” relating to the numerical range are numerical values that can be arbitrarily combined.

[Base oil]
There is no restriction | limiting in particular as a base oil, Arbitrary things can be suitably selected and used from the mineral oil and synthetic oil which can be used as a base oil of lubricating oil.
As mineral oil, for example, a lubricating oil fraction obtained by distillation under reduced pressure of atmospheric residual oil obtained by atmospheric distillation of crude oil can be desolvated, solvent extracted, hydrocracked, solvent dewaxed, catalytic dehydrated. Mineral oil (hydrorefined mineral oil) refined by one or more of wax, hydrorefining, etc., or base oil produced by isomerizing wax such as GTL WAX (Gas Liquid Wax) Of these, mineral oil (hydrorefined mineral oil) treated by hydrorefining is preferred. By using hydrorefined mineral oil, it becomes easy to improve the% C _P and viscosity index described later.
Synthetic oils include, for example, polyα-olefins such as polybutene, α-olefin homopolymers and copolymers (for example, ethylene-α-olefin copolymers), such as polyol esters, dibasic acid esters, and phosphate esters. And various esters, for example, various ethers such as polyphenyl ether and polyglycol, alkylbenzene, alkylnaphthalene and the like. Of these synthetic oils, poly α-olefins are particularly preferred.
As base oil, mineral oil may be used independently and may be used in combination of 2 or more type. Moreover, synthetic oil may be used independently and may be used in combination of 2 or more type. Furthermore, one or more mineral oils and one or more synthetic oils may be used in combination.
Especially, it is preferable that base oil is a base oil which consists of mineral oil and synthetic oil. In this case, it is more preferable to use hydrorefined mineral oil as the mineral oil and poly α-olefin as the synthetic oil. When the base oil is composed of mineral oil and synthetic oil, the mass ratio of the synthetic oil content to the total base oil (synthetic oil / total base oil) is preferably 0.1 or more and 0.6 or less. 0.15 or more and 0.5 or less is more preferable, and 0.2 or more and 0.4 or less is more preferable.
In the lubricating oil composition, the base oil is usually 65% by mass or more, preferably 70% by mass or more and 97% by mass or less, more preferably 75% by mass or more and 95% by mass or less, based on the total amount of the lubricating oil composition. Is done.

The viscosity of the base oil is not particularly limited, but the kinematic viscosity at 100 ° C. is preferably 2 mm ² / s to 30 mm ² / s, more preferably 3 mm ² / s to 15 mm ² / s, and still more preferably 3 .5mm or less in the range ² / s or more 10 mm ² / s.
When the kinematic viscosity at 100 ° C. is 2 mm ² / s or more, the evaporation loss is small, and when it is 30 mm ² / s or less, the power loss due to the viscous resistance is suppressed, and the fuel efficiency improvement effect is obtained.
Furthermore, the viscosity index of the base oil is preferably 100 or more, more preferably 110 or more, still more preferably 120 or more, and still more preferably 130 or more. A base oil having a viscosity index of 100 or more has a small change in viscosity due to a change in temperature.
By making the viscosity index of the base oil within the above range, it becomes easy to improve the viscosity characteristics of the lubricating oil composition.
The NOACK evaporation amount (250 ° C., 1 hour) of the base oil is preferably 15.0% by mass or less, more preferably 14.0% by mass or less.

Further, as the mineral oil, those having an aromatic content (% C _A ) of 3.0% or less and a sulfur content of 10 mass ppm or less by ring analysis are preferably used. Here, the% C _A by ring analysis shows a proportion of aromatic content calculated by ring analysis n-d-M method (percentage).
_A mineral oil having a% CA of 3.0% or less and a sulfur content of 10 mass ppm or less has good oxidation stability, and more easily suppresses an increase in viscosity when mixed with biofuel. Preferred% _{C A} is 1.0 or less, more preferably 0.5 or less, even more preferably 0.1 or less, sulfur content is more preferably at most 5 mass ppm.
Moreover, mineral oils, paraffin content by ring analysis (% C _P) is preferably at least 75, more preferably 80 or more, more preferably 85 or more. By making the paraffin content 75 or more, the oxidation stability of the base oil becomes good, and it becomes easier to suppress an increase in viscosity when mixed with biofuel. Here, the% C _P by ring analysis shows a proportion of paraffin component calculated in ring analysis n-d-M method (percentage).
In addition, each property of base oil, such as kinematic viscosity and a viscosity index, is specifically measured by the method described in the Example mentioned later.

[Succinimide compound (A)]
The succinimide compound (A) used in the present embodiment is an ashless dispersant, an alkenyl or alkyl succinic monoimide and its boron derivative (A1), and an alkenyl or alkyl succinic acid bisimide and its boron derivative (A2). 1 type or 2 types or more selected from.
The content of the component (A) on the basis of the total amount of the lubricating oil composition is 550 mass ppm or more in terms of nitrogen atoms. If it is less than 550 mass ppm, the effect of blending the component (A) cannot be sufficiently obtained, and it may be difficult to suppress an increase in viscosity when mixed with biofuel.
The content of the component (A) in terms of nitrogen atom is preferably 560 mass ppm or more, more preferably 700 mass ppm or more from the above viewpoint.
On the other hand, the upper limit of the content of component (A) in terms of nitrogen atom is not particularly limited, but is usually 1500 ppm by mass or less, preferably 1250 ppm by mass or less, in order to exert an effect commensurate with the addition amount. Preferably it is 1000 mass ppm or less.

Further, the ratio [(A1 / A2)] of the content in terms of nitrogen atom of the component (A1) and the content in terms of nitrogen atom of the component (A2) in the lubricating oil composition is 0 or more and 0.3. It becomes the following. That is, as the component (A), the content of the component (A1) (monoimide) is relatively reduced or not included. In this embodiment, if the ratio [(A1 / A2)] is greater than 0.3, that is, if the monoimide content is relatively increased, it is difficult to suppress an increase in viscosity when biofuel is mixed.
The ratio [(A1 / A2)] is preferably 0 or more and 0.23 or less, and more preferably 0 or more and 0.20 or less, from the viewpoint of appropriately suppressing an increase in viscosity when biofuel is mixed.

Examples of the alkenyl or alkyl succinic monoimide used as the component (A1) include compounds represented by the following formula (1). Examples of the alkenyl or alkyl succinic acid bisimide used as the component (A2) include compounds represented by the following formula (2).
Further, it is selected from the group consisting of a compound represented by the following formula (1) or a compound represented by the following formula (2) and an alcohol, aldehyde, ketone, alkylphenol, cyclic carbonate, epoxy compound, organic acid and the like. A modified polybutenyl succinimide obtained by reacting with one compound can also be used.

(In the formula, R ¹ , R ³ and R ⁴ are each an alkenyl group or an alkyl group, R ³ and R ⁴ may be the same or different from each other, and R ² , R ⁵ and R ⁶ are each a carbon number. In the alkylene group of 2 to 5, R ⁵ and R ⁶ may be the same or different from each other, r represents an integer of 1 to 10, and s represents 0 or an integer of 1 to 10.

In the formulas (1) and (2), the number average molecular weights of R ¹ , R ³ and R ⁴ are each 500 or more and 3000 or less, more preferably 700 or more and 2700 or less, and further preferably 800 or more and 2500 or less. .
When R ¹ , R ³ and R ⁴ have a number average molecular weight of 500 or more, the solubility in the base oil is improved. Moreover, it becomes easy to obtain favorable cleanliness and it becomes easy to exhibit the function as a dispersing agent because it will be 3000 or less.
R is preferably 2 or more and 5 or less, more preferably 3 or more and 4 or less. When r is 2 or more, good cleanliness is exhibited, and when r is 5 or less, solubility in base oil is improved.
Further, in the formula (2), s is preferably 3 or more and 8 or less, more preferably 4 or more and 7 or less. When s is 3 or more, good cleanliness is exhibited, and when s is 8 or less, solubility in base oil is improved.

Examples of the alkenyl group include a polybutenyl group, a polyisobutenyl group, and a group derived from an ethylene-propylene copolymer, and examples of the alkyl group include hydrogenated groups thereof.
Suitable alkenyl groups include polybutenyl or polyisobutenyl groups. The polybutenyl group can be obtained, for example, by polymerizing a mixture of 1-butene and isobutene or high-purity isobutene. Moreover, as a suitable alkyl group, a polybutenyl group or a polyisobutenyl group is hydrogenated.

Alkenyl or alkyl succinic acid monoimide and alkenyl or alkyl succinic acid bisimide are usually alkenyl succinic anhydride obtained by reaction of polyolefin with maleic anhydride, or alkyl succinic anhydride obtained by hydrogenation thereof. It can be produced by reacting with a polyamine. Succinic monoimide and succinic bisimide can be prepared by changing the reaction ratio of alkenyl succinic anhydride or alkyl succinic anhydride and polyamine, respectively.
As the olefin monomer for forming the polyolefin, one or more of α-olefins having 2 to 8 carbon atoms can be mixed and used, and a mixture of isobutene and 1-butene is preferably used. it can.
On the other hand, polyamines include diamines such as ethylenediamine, propylenediamine, butylenediamine, and pentylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di (methylethylene) triamine, dibutylenetriamine, and butylenetetramine. And polyalkylene polyamines such as pentapentylenehexamine.

As the boron derivative of alkenyl or alkyl succinic acid monoimide, those prepared by a conventional method can be used.
For example, after reacting the above polyolefin with maleic anhydride to make alkenyl succinic anhydride, the above polyamine and boron oxide, boron halide, boric acid, boric anhydride, boric acid ester, ammonium boric acid It is obtained by reacting with an intermediate obtained by reacting a boron compound such as a salt and imidizing.
When the component (A1) contains a boron derivative, the boron content in the component (A1) is not particularly limited, but is usually 0.1% by mass to 5% by mass, preferably 0.5% by mass to 3% by mass. It is as follows.
Further, a boron derivative of alkenyl or alkyl succinic acid bisimide can be produced in the same manner, and the preferred range of the boron content in the component (A2) is also the same.

The component (A1) may or may not be contained in the lubricating oil composition as described above. When the component (A1) is contained, the component (A1) may be composed of one of alkenyl or alkyl succinic monoimide and its boron derivative, or may include both. However, the component (A1) preferably contains a boron derivative of alkenyl or alkyl succinic monoimide. When the component (A1) contains a boron derivative, it is easy to reduce the coefficient of friction between metals due to the component (A), and it is easy to suppress an increase in viscosity when mixed with biofuel.
When the component (A1) contains a boron derivative, the boron content derived from the component (A1) is preferably 50 ppm by mass or more and 300 ppm by mass or less based on the total amount of the lubricating oil composition. By setting the boron content to 50 mass ppm or more, the effect of reducing the coefficient of friction between metals by the component (A) is more easily exhibited. Moreover, it becomes easy to reduce the ratio of (A1) component in (A) component by setting it as 300 mass ppm or less.
From the above viewpoint, the boron content derived from the component (A1) is more preferably 80 ppm to 300 ppm by mass, and further preferably 100 ppm to 250 ppm by mass.

On the other hand, the component (A2) is contained as an essential component in the lubricating oil composition. The component (A2) may contain both alkenyl or alkyl succinic acid bisimide and its boron derivative, or may consist of either one, but is preferably made of alkenyl or alkyl succinic acid bisimide.
And when (A) component contains both (A1) and (A2) component, while (A1) component contains the boron derivative of alkenyl or alkyl succinic monoimide, (A2) component is alkenyl or It preferably consists of an alkyl succinic acid bisimide. This makes it easier to reduce the coefficient of friction between metals while appropriately suppressing an increase in viscosity when biofuel is mixed.

[Molybdenum compound (B)]
The molybdenum compound (B) is one or more selected from a dinuclear organic molybdenum compound (B1) and a trinuclear organic molybdenum compound (B2). In the present embodiment, by including the molybdenum-based compound (B) in the lubricating oil composition, it is possible to lower the coefficient of friction between metals and to improve fuel economy.
In addition, when the lubricating oil composition contains the molybdenum-based compound (B), the viscosity of the lubricating oil composition tends to increase when biofuel is mixed. In this embodiment, in addition to the component (B), By containing the components (A), (C), and (D) at an appropriate content ratio or content, it becomes possible to prevent an increase in viscosity when biofuel is mixed.
The content of the molybdenum-based compound (B) on the basis of the total amount of the lubricating oil composition is in the range of 200 mass ppm to 600 mass ppm in terms of molybdenum atoms. If it is less than 200 ppm by mass, the coefficient of friction between metals cannot be made sufficiently low, and the fuel economy cannot be made excellent. On the other hand, if it exceeds 600 ppm by mass, it is difficult to suppress an increase in the viscosity of the lubricating oil composition when biofuel is mixed even if the components (A), (C), and (D) are appropriately contained. .
From the above viewpoint, the content of the molybdenum compound (B) is preferably 250 mass ppm or more and 500 mass ppm or less, and more preferably 300 mass ppm or more and 500 mass ppm or less.

Examples of the dinuclear organic molybdenum compound (B1) include dinuclear molybdenum dithiocarbamate, and specifically include a compound represented by the following formula (3).

[In the formula (3), R ¹¹ to R ¹⁴ represent a hydrocarbon group having 7 to 22 carbon atoms, and R ¹¹ to R ¹⁴ may be the same or different. X ¹ to X ^{4 each} represents a sulfur atom or an oxygen atom. ]

In the compound of the above formula (3), when the carbon number of each of R ¹¹ to R ¹⁴ is 7 or more, the oil solubility becomes good and it is easy to dissolve in the lubricating oil composition. On the other hand, when it is 22 or less, the melting point becomes low, the handling property becomes good, and the friction reducing effect is easily exhibited. From these viewpoints, the number of carbon atoms of R ¹¹ to R ¹⁴ is preferably 7 to 18, more preferably 7 to 14, and particularly preferably 8 to 13. The total number of carbon atoms of R ¹¹ to R ¹⁴ is preferably 34 to 80, more preferably 36 to 60, and still more preferably 38 to 54.
Examples of the hydrocarbon group for R ¹¹ to R ¹⁴ include an alkyl group, an alkenyl group, an alkylaryl group, a cycloalkyl group, and a cycloalkenyl group, and a branched or straight chain alkyl group or alkenyl group is preferable. A chain or straight chain alkyl group is more preferred. Examples of the branched or straight chain alkyl group include n-octyl group, 2-ethylhexyl group, isononyl group, n-decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group and the like.
In addition, from the viewpoint of solubility in base oil, storage stability, and friction reducing ability, the binuclear organomolybdenum compound represented by the formula (3) is an alkyl group in which R ¹¹ and R ¹² are the same, R ¹³ and R ^14. Are the same alkyl groups, and the alkyl groups of R ¹¹ and R ¹² are preferably different from the alkyl groups of R ¹³ and R ¹⁴ .

In the formula (3), X ¹ to X ⁴ represent a sulfur atom or an oxygen atom, and X ¹ to X ⁴ may be the same or different. When both sulfur atoms and oxygen atoms are contained, the ratio of sulfur atoms to oxygen atoms is preferably sulfur atom / oxygen atoms = 1/3 to 3/1, more preferably 1.5 / 2.5 to 3/1. It is. Further, all of X ¹ to X ⁴ may be sulfur atoms or oxygen atoms, but it is more preferable that all of them are oxygen atoms.

Examples of the trinuclear organic molybdenum compound include those represented by the following formula (4).
_{Mo 3 S k E m L n} A p Q z (4)
[In formula (4), each E is independently oxygen or selenium. k is an integer of at least 1, m is 0 or a positive integer, and k + m is 4 or more and 10 or less. L is independently an anionic ligand having an organic group containing a carbon atom, and the total number of carbon atoms of the organic group in each ligand is 14 or more, and each ligand may be the same or different. It may be. n is a positive integer of 1 or more and 4 or less. A is an anion other than L. p is 0 or a positive integer. Q is a compound which donates a neutral electron independently. z is 0 or more and 5 or less, and includes a non-stoichiometric value. ]

In the formula (4), when the total number of carbon atoms of the organic group in each ligand represented by L is 14 or more, the solubility in the base oil is good. The total number of carbon atoms of the organic group in each ligand is preferably 14 to 50, more preferably 16 to 30, and still more preferably 18 to 24. The anionic ligand is preferably a monoanionic ligand (monovalent anionic ligand).

Each ligand is preferably any one selected from, for example, ligands represented by the following formulas (4-A) to (4-D).

[In the formulas (4-A), (4-B), (4-C) and (4-D), X ²¹ to X ²⁷ and Y are each independently an oxygen atom or a sulfur atom. In the formulas (4-A), (4-B), (4-C) and (4-D), R ²¹ to R ²⁵ are independent organic groups, and R ²¹ to R ²⁵ are the same. It may or may not be. The organic group of R ²¹ to R ²³ has 14 or more carbon atoms. The sum of the carbon number of the organic group of R ²⁴ and the carbon number of the organic group of R ²⁵ is 14 or more. ]
Preferably R ²¹ carbon atoms organic group of each - ^{R 23} is 14 to 50, more preferably 16 to 30, 18 - and more preferably a 24. The total number of carbon atoms of the organic group of R ^{24 and} the organic group of R ²⁵ is preferably 14 to 50, more preferably 16 to 30, and more preferably 18 to 24. Is more preferable. Further, the carbon number of the organic group of R ²⁴ and the carbon number of the organic group of R ²⁵ are each preferably 7 to 30, more preferably 7 to 20, and 8 to 13 Is more preferable.
The organic group of R ^{24 and} the organic group of R ²⁵ may be the same or different, but are preferably different. Further, the carbon number of the organic group of R ²⁴ and the carbon number of the organic group of R ²⁵ may be the same or different, but are preferably different.
In the formula (4), the ligand preferably includes a ligand represented by the formula (4-D). In the formula (4), it is preferable that all ligands are the same. Furthermore, it is more preferable that all the ligands are ligands represented by the above formula (4-D).

Preferably, the organic group is a hydrocarbyl group such as an alkyl group, an aryl group, a substituted aryl group, and an ether group. More preferably, each ligand has the same hydrocarbyl group.
The term “hydrocarbyl” refers to a substituent having a carbon atom that is directly bonded to the remainder of the ligand, and within the scope of this embodiment, the property is primarily hydrocarbyl. Such substituents include the following.
1. Hydrocarbon substituents As hydrocarbon substituents, substituted with aliphatic substituents such as alkyl and alkenyl, alicyclic substituents such as cycloalkyl and cycloalkenyl, aromatic groups, aliphatic groups and alicyclic groups An aromatic nucleus, a cyclic group in which the ring is completed via another location in the ligand (ie any two of the indicated substituents may together form an alicyclic group) Can be mentioned.
2. Substituted hydrocarbon substituents Examples of substituted hydrocarbon substituents include those in which the hydrocarbon substituent is substituted with a non-hydrocarbon group that does not change the properties of the hydrocarbyl. Examples of the non-hydrocarbon group include halogen groups such as chloro and fluoro, amino groups, alkoxy groups, mercapto groups, alkyl mercapto groups, nitro groups, nitroso groups, and sulfoxy groups.

Preferred ligands include alkyl xanthates, carboxylates, dialkyldithiocarbamates, and mixtures thereof. Most preferred is a dialkyldithiocarbamate.

In the formula (4), E (oxygen or selenium) can replace sulfur in the core described later, for example. k + m is preferably 4 or more and 7 or less.
Moreover, as Q in Formula (4), water, an amine, alcohol, ether, a phosphine, etc. are mentioned. The anions of Q may be the same or different, but are preferably the same. The neutral electron donating compound Q is present to satisfy the empty coordination on the trinuclear molybdenum compound.
Moreover, the anion of A in Formula (4) may be a monovalent anion or a divalent anion. Specific examples of A include disulfide, hydroxide, alkoxide, amide and thiocyanate or derivatives thereof.

In one embodiment of Formula (4), k is 4 or more and 7 or less, n is 1 or 2, L is a monoanionic ligand, and p is a compound based on an anionic charge in A. It is an integer that imparts electrical neutrality, and each of m and z is 0.
In another embodiment of formula (4), k is 4 or more and 7 or less, L is a monoanionic ligand, n is 4, and each of p, m, and z is 0.

In addition, the trinuclear organomolybdenum compound of the formula (4) has, for example, a core represented by the following formula (4-E) or (4-F). Each core has a net electrical charge of +4. These cores are surrounded by anionic ligands and anions other than the anionic ligands present as needed.

One skilled in the art will select the appropriate anionic ligand (L) and other anions (A) for the formation of the trinuclear molybdenum-sulfur compound, depending on, for example, the sulfur and number of E atoms present in the core. It will be appreciated that the total anionic charge constituted by the sulfur atom, E atom if present, L and A if present must be -4. The trinuclear molybdenum-sulfur compound may also contain cations other than molybdenum, such as (alkyl) ammonium, amine or sodium, if the anionic charge exceeds -4. A preferred embodiment of the anionic ligand (L) and the other anion (A) is a configuration having four monoanionic ligands.
Molybdenum-sulfur cores, for example, structures represented by the above formulas (4-E) and (4-F), bind to one or more polydentate ligands, ie molybdenum atoms, to form oligomers. Can be interconnected by ligands having more than one possible functional group.

The trinuclear organic molybdenum compound can be prepared, for example, by the following methods (1) to (3). The solvent used in (1) to (3) may be, for example, aqueous or organic.
(1) in a suitable _{solvent, (NH 4) 2 Mo 3} S 13 · n (H 2 O) a molybdenum source such as (where, n represents vary between 0 and 2, the non-stoichiometric Is reacted with a suitable ligand source such as tetraalkyl thiuram disulfide.
(2) In an appropriate solvent, a molybdenum source such as (NH ₄ ) ₂ Mo ₃ S ₁₃ .n (H ₂ O), a ligand source such as tetraalkylthiuram disulfide and dialkyldithiocarbamic acid, a cyanide ion, and sulfurous acid It reacts with a sulfur extracting agent such as ions.
(3) Trinuclear molybdenum-sulfur such as [M ′] ₂ [Mo ₃ S ₇ A ₆ ] (where M ′ is a counter ion and A is a halogen such as Cl, Br, or I). The halide salt is reacted with a ligand source such as a dialkyldithiocarbamic acid in a suitable solvent.

In the present embodiment, the trinuclear organic molybdenum compound is preferably a dithiocarbamate compound, that is, a trinuclear molybdenum dithiocarbamate. Particularly useful compounds are trinuclear molybdenum dialkyl dithiocarbamate represented by the formula _Mo 3 _S 7 ((alkyl) _{2 dithiocarbamate) 4.}
Moreover, the lubricating oil composition may further contain a mononuclear organic molybdenum compound as long as the friction reducing effect is not impaired.

[Overbased sodium sulfonate (C)]
The lubricating oil composition contains overbased sodium sulfonate (C). In this embodiment, as a metallic detergent, in addition to the basic calcium detergent (D) described later, an overbased sodium sulfonate (C) is used in combination so that the base number of the lubricating oil composition can be extended over a long period of time. It becomes possible to maintain it well. And oxidation stability becomes favorable and it becomes possible to suppress especially the viscosity increase at the time of biofuel mixing appropriately.
The content of the overbased sodium sulfonate (C) on the basis of the total amount of the lubricating oil composition is 250 mass ppm or more in terms of sodium atoms. If it is less than 250 ppm by mass, the effect of the component (C) cannot be fully exhibited, and it becomes difficult to suppress an increase in viscosity when biofuel is mixed. On the other hand, the upper limit of the content of the component (C) is not limited as long as the sulfated ash is within a specified range described later, but is preferably 500 ppm by mass or less. By setting it as 500 mass ppm or less, it is prevented that the abrasion resistance of the lubricating oil composition for internal combustion engines falls by excessive addition of (C) component.
From the above viewpoint, the content of the component (C) is preferably 280 mass ppm or more and 480 mass ppm or less, more preferably 350 mass ppm or more and 450 mass ppm or less in terms of sodium atom.

Examples of the overbased sodium sulfonate include those obtained by overbasing sodium salts of various sulfonic acids. Examples of the sulfonic acid used here include aromatic petroleum sulfonic acid, alkyl sulfonic acid, aryl sulfonic acid, alkylaryl sulfonic acid, and the like. Specifically, for example, dodecyl benzene sulfonic acid, dilauryl cetyl benzene sulfonic acid, Examples thereof include paraffin wax-substituted benzenesulfonic acid, polyolefin-substituted benzenesulfonic acid, polyisobutylene-substituted benzenesulfonic acid, and naphthalenesulfonic acid.

The base number of the overbased sodium sulfonate (C) is preferably 200 mgKOH / g or more. By setting it as 200 mgKOH / g or more, the base number maintenance property and oxidation stability of a lubricating oil composition become favorable, and it becomes easy to suppress an above-mentioned viscosity raise. In addition, the upper limit of the base number of the component (C) is not particularly limited, but is preferably 500 mgKOH / g or less in order to prevent the formation of a precipitate or the like. From these viewpoints, the base number of the component (C) is more preferably from 300 mgKOH / g to 500 mgKOH / g, still more preferably from 400 mgKOH / g to 500 mgKOH / g.
The base number is the total base number measured by the perchloric acid method specified in JISK-2501: 2003.

[Overbased calcium detergent (D)]
The lubricating oil composition contains one or more selected from overbased calcium salicylate (D1) and overbased calcium phenate (D2) as the overbased calcium detergent (D). .
The content of the overbased calcium detergent (D) based on the total amount of the composition may be adjusted so that the sulfated ash content described later falls within a specified range, but preferably 500 mass ppm or more and 1500 mass in terms of calcium atom. ppm or less. By setting the content within this range, it becomes easy to improve the cleanliness of the lubricating oil composition, and it becomes easy to suppress an increase in viscosity when mixed with biofuel. From these viewpoints, the content of the component (D) is preferably 750 mass ppm or more and 1450 mass ppm or less, and more preferably 1000 mass ppm or more and 1350 mass ppm or less in terms of calcium atom.

The base number of the overbased calcium-based detergent (D) is preferably 150 mgKOH / g or more. When the base number is 150 mgKOH / g or more, the function of the component (D) as a detergent is easily exhibited, and the base number maintenance property and oxidation stability of the lubricating oil composition are easily improved. Moreover, it is preferable that the base number of an overbased calcium type detergent (D) is 500 mgKOH / g or less. By setting it as 500 mgKOH / g or less, it becomes difficult to produce a precipitate in the composition. From these viewpoints, the base number of the overbased calcium-based detergent (D) is more preferably 200 mass ppm or more and 400 mgKOH / g or less, and further preferably 200 mass ppm or more and 350 mgKOH / g or less.
The component (D) is preferably an overbased calcium salicylate in order to more easily suppress an increase in viscosity when mixed with biofuel.

Examples of the overbased calcium salicylate (D1) include those obtained by overbasing a calcium metal salt of an alkyl salicylic acid such as a dialkyl salicylic acid. The alkyl group constituting the alkyl salicylic acid preferably has 4 to 30 carbon atoms, more preferably a linear or branched alkyl group having 6 to 18 carbon atoms.
Examples of the overbased calcium phenate (D2) include those obtained by overbasing calcium metal salts such as alkylphenol, alkylphenol sulfide, and Mannich reaction product of alkylphenol. Here, the alkyl group in the calcium phenate preferably has 4 to 30 carbon atoms, and more preferably a linear or branched alkyl group having 6 to 18 carbon atoms.

[Antioxidant (E)]
The lubricating oil composition preferably contains one or more antioxidants (E) selected from a phenolic antioxidant (E1) and an amine antioxidant (E2).
The content of the antioxidant (E) is preferably 1.0% by mass or more based on the total amount of the lubricating oil composition. When the content is 1.0% by mass or more, the oxidation stability of the lubricating oil composition is improved, and the increase in viscosity when mixed with biofuel is more easily suppressed.
Further, the content of the antioxidant (E) is more preferably 1.0% by mass or more and 3.0% by mass or less, and 1.25% by mass or more and 2.0% by mass based on the total amount of the lubricating oil composition. More preferably, it is as follows. Antioxidant (E) makes it easy to exhibit an effect commensurate with the content by setting the content to the upper limit or less. The lubricating oil composition may contain any one of a phenolic antioxidant and an amine antioxidant as the antioxidant (E), but both the phenolic antioxidant and the amine antioxidant are contained. It is more preferable to contain.

(Phenolic antioxidant (E1))
Examples of the phenolic antioxidant (E1) include monophenolic antioxidants and bisphenolic antioxidants.
Monophenol antioxidants include alkyl esters of 3,5-bis (1,1-dimethylethyl) -4-hydroxybenzenepropanoic acid (the alkyl group has 4 to 20, preferably 6 to 18, carbon atoms, More preferably 7-9); 2,6-di-t-butyl-4 such as 2,6-di-t-butyl-4-methylphenol and 2,6-di-t-butyl-4-ethylphenol -Alkylphenol (alkyl group having 1 to 4 carbon atoms); 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-amyl-p-cresol and the like.

As bisphenol antioxidants, 4,4′-methylenebis (2,6-di-t-butylphenol), 4,4′-bis (2,6-di-t-butylphenol), 4,4′- Bis (2-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4 , 4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-isopropylidenebis (2,6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6- Nonylphenol), 2,2′-isobutylidenebis (4,6-dimethylphenol), 2,2′-methylenebis (4-methyl-6-cyclohexylphenol), 4,4 -Thiobis (2-methyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-thiobis (4-methyl-6-t-butylphenol), Bis (3-methyl-4-hydroxy-5-t-butylbenzyl) sulfide, bis (3,5-di-t-butyl-4-hydroxybenzyl) sulfide, thiodiethylenebis [3- (3,5-di -T-butyl-4-hydroxyphenyl) propionate] and the like.

(Amine-based antioxidant (E2))
Examples of the amine-based antioxidant (E2) include mono-t-butyldiphenylamine, monooctyldiphenylamine, and monononyldiphenylamine, which are monoalkyldiphenylamines having an alkyl group having 4 to 12 carbon atoms; bis (4-butylphenyl) amine Bis (4-pentylphenyl) amine, bis (4-hexylphenyl) amine, bis (4-heptylphenyl) amine, bis (4-octylphenyl) amine, bis (4-nonylphenyl) amine, 4-butyl- 4'-octyldiphenylamine and other dialkyldiphenylamines having 4 to 12 carbon atoms in each alkyl group; tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, tetranonyldiphenylamine, di (2,4-diethylphenyl) Nyl) amine, di (2-ethyl-4-nonylphenyl) amine and the like, polyalkyldiphenylamine having 3 or more alkyl groups, each alkyl group having 1 to 10 carbon atoms; methylphenyl-α-naphthylamine, ethyl Phenyl-α-naphthylamine, butylphenyl-α-naphthylamine, hexylphenyl-α-naphthylamine, heptylphenyl-α-naphthylamine, octylphenyl-α-naphthylamine, nonylphenyl-α-naphthylamine, t-dodecylphenyl-α-naphthylamine, etc. And alkylphenyl-α-naphthylamine having at least one alkyl group having 1 to 12 carbon atoms, or phenyl-α-naphthylamines exemplified by phenyl-α-naphthylamine and the like.

As the antioxidant (E), among the above, alkyl esters of 3,5-bis (1,1-dimethylethyl) -4-hydroxybenzenepropanoic acid and dialkyldiphenylamine are preferably used. It is more preferable. The most preferred combination is an alkyl ester of 3,5-bis (1,1-dimethylethyl) -4-hydroxybenzenepropanoic acid (the alkyl group has 7 to 9 carbon atoms) and bis (4-nonyl). And a combination with phenyl) amine.

[Viscosity index improver (F)]
The lubricating oil composition may contain a viscosity index improver (F) in order to improve the viscosity index of the lubricating oil composition. As the viscosity index improver (F), polymethacrylate; olefin copolymer such as ethylene-propylene copolymer; styrene such as styrene-diene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer A styrene-based polymer is preferable among them.
The weight average molecular weight of the viscosity index improver (F) is usually 10,000 or more and 1,000,000 or less, preferably 50,000 or more and 800,000 or less, more preferably 100,000 or more and 700,000 or less. In addition, the weight average molecular weight here is a value obtained using polystyrene as a calibration curve by the GPC method.
The content of the viscosity index improver (F) is appropriately adjusted according to the weight average molecular weight and the desired viscosity index value, but is preferably 10% by mass or less, more preferably, based on the total amount of the lubricating oil composition. It is 0.1 mass% or more and 6 mass% or less, More preferably, it is 0.2 mass% or more and 4 mass% or less. In general, commercially available viscosity index improvers are usually distributed in a diluted state in a diluent oil (mineral oil or synthetic oil) in consideration of handling properties and solubility in base oils. The content of the above-mentioned viscosity index improver (F) means a resin equivalent amount excluding diluent oil.

[Other additives]
The lubricating oil composition may further contain other additives other than the components (A) to (F) as long as the effects of the present invention are not impaired. Examples of other additives include one or more selected from antiwear agents, pour point depressants, metal deactivators, antifoaming agents, and the like. The other additive is usually 20% by mass or less, preferably 15% by mass or less, more preferably 10% by mass or less, based on the total amount of the lubricating oil composition. In addition, as other additives, there are additives containing metal components such as organic zinc dithiophosphate, but the content of such additives is adjusted so that the sulfated ash content described later is within a predetermined range. Is done.

In the present embodiment, as the antiwear agent, organic zinc dithiophosphate is preferably used. Examples of the organic zinc zinc dithiophosphate include zinc dihydrocarbyl dithiophosphate. Each hydrocarbyl group contained in zinc dihydrocarbyl dithiophosphate has 1 to 24 carbon atoms, preferably 3 to 24 carbon atoms, more preferably 5 to 18 carbon atoms. Examples of the hydrocarbyl group include an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group. The alkyl group and alkenyl group may be branched, straight chain, or have a cyclic structure. In these, the zinc dialkyl dithiophosphate whose hydrocarbyl group is an alkyl group is preferable.
However, as an antiwear agent, instead of organic dithiophosphate or in combination with organic dithiophosphate, zinc dithiocarbamate, zinc phosphate, disulfides, sulfurized olefins, sulfurized fats and oils, sulfurized esters, thiols Sulfur-containing compounds such as carbonates; phosphorus-containing compounds such as phosphites, phosphate esters, phosphonate esters, and amine salts or metal salts thereof; thiophosphites, thiophosphonates, And sulfur and phosphorus-containing antiwear agents such as amine salts or metal salts thereof may be used.

Examples of the metal deactivator include benzotriazole, triazole derivatives, benzotriazole derivatives, and thiadiazole derivatives.
Examples of the pour point depressant include ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polymethacrylate, polyalkylstyrene, etc. Polymethacrylate is preferably used.
Examples of the antifoaming agent include silicone oil, fluorosilicone oil, and fluoroalkyl ether.
The lubricating oil composition may contain additives other than those described above as other additives, for example, antioxidants other than the antioxidant (E), specifically, sulfur-based oxidation. An inhibitor, a phosphorus antioxidant, etc. may be contained, and an ashless friction modifier, a rust inhibitor, etc. may be contained.

<Sulfated ash>
The lubricating oil composition has a sulfated ash content of 0.8% by mass or less. If the sulfated ash content exceeds 0.8% by mass, the filter in the exhaust gas purification device such as DPF is clogged, and the performance of the catalyst in the exhaust gas purification device is likely to decrease. From the viewpoint of further suppressing these adverse effects on the exhaust gas purification device, the sulfated ash content is preferably 0.78% by mass or less, and more preferably 0.75% by mass or less.
Further, the lower limit of sulfated ash is not particularly limited, but is usually 0.4% by mass or more, preferably 0.8% in order to contain an appropriate amount of the above components (A) to (D) in the lubricating oil composition. It is 50 mass% or more, More preferably, it is 0.60 mass% or more.
In addition, sulfate ash means the value measured based on JISK2272: 1998.

As described above, the lubricating oil composition may contain metal atoms by containing the components (B) to (D), and may contain boron atoms derived from the component (A). In the components A) to (D), the amount of metal and the amount of boron in each component are adjusted so that the sulfated ash content is 0.8% by mass or less.
Since the lubricating oil composition of the present embodiment has a low sulfated ash content, it is difficult to increase the content of the components (B) to (D) and the boron content derived from the component (A). By using a combination of D) component in an appropriate amount, it is possible to suppress an increase in viscosity when biofuel is mixed while lowering the coefficient of friction between metals.

The lubricating oil composition according to one embodiment of the present invention includes a base oil and the components (A), (B), (C), and (D), and the above-mentioned various lubricating oil additives. More specifically, for example, base oil, alkenyl or alkyl succinic acid monoimide and its boron derivative (A1), and alkenyl or alkyl succinic acid bisimide and its boron derivative ( At least one succinimide compound (A) selected from the group consisting of A2), at least selected from the group consisting of a dinuclear organic molybdenum compound (B1) and a trinuclear organic molybdenum compound (B2) One molybdenum-based compound (B), overbased sodium sulfonate (C), overbased calcium salicylate (D1), and persalt At least one overbased calcium detergent (D) selected from the group consisting of soluble calcium phenates (D2), phenolic antioxidants and amine antioxidants, viscosity index improvers, and dialkyls It consists of zinc dithiophosphate, a metal deactivator, a pour point depressant, and an antifoaming agent, and the contents of the component (A), the component (B) and the component (C) are within the predetermined range, (A1 / A2) and the lubricating oil composition whose sulfated ash content is the said predetermined range is mentioned.

<Usage method of lubricating oil composition, lubricating method>
The lubricating oil composition is used for lubricating various internal combustion engines for automobiles and the like, but is preferably used for an internal combustion engine that is driven by burning a fuel containing biofuel. Examples of the internal combustion engine include a gasoline engine, a diesel engine, and a gas engine, and a diesel engine is preferable. That is, what is called biodiesel fuel is used as the biofuel.

Examples of the biofuel include one or more selected from natural fats and oils, hydrogenated products of natural fats and oils, transesterified products of natural fats and oils, and hydrotreated products of transesterified products of natural fats and oils.
As natural fats and oils, various animal and vegetable fats and oils widely existing in the natural world can be used, but vegetable oils mainly composed of esters of fatty acids and glycerin, such as safflower oil, soybean oil, rapeseed oil, palm oil, and palm kernel. Oil, cottonseed oil, coconut oil, rice bran oil, sesame oil, castor oil, linseed oil, olive oil, tung oil, coconut oil, peanut oil, kapok oil, cacao oil, wood wax, sunflower oil, corn oil, etc. are preferably used, more preferably Soybean oil and rapeseed oil are used.

The hydrotreated product of natural fats and oils is a so-called hydrogenated product of the aforementioned fats and oils in the presence of a suitable hydrogenation catalyst. As hydrogenation catalysts, nickel catalysts, platinum group (Pt, Pd, Rh, Ru) catalysts, cobalt catalysts, chromium oxide catalysts, copper catalysts, osmium catalysts, iridium catalysts, molybdenum catalysts Etc. Further, it is also preferable to use a combination of two or more of the above catalysts as the hydrogenation catalyst.
The transesterified product of natural fats and oils is an ester obtained by subjecting a triglyceride constituting natural fats and oils to a transesterification reaction in the presence of a suitable ester synthesis catalyst. For example, the fatty acid ester used as a biofuel is manufactured by transesterifying a lower alcohol and fats and oils in the presence of the ester synthesis catalyst. The lower alcohol is used as an esterifying agent, and examples thereof include alcohols having 5 or less carbon atoms such as methanol, ethanol, propanol, butanol, and pentanol. Is preferred. Such a lower alcohol is generally used in an amount equal to or greater than that of the oil or fat.
The hydrotreated product of the transesterified product of natural fats and oils is a product obtained by hydrogenating the transesterified product described above in the presence of an appropriate hydrogenation catalyst.
Biofuel can be suitably used as a mixed fuel by adding it to a fuel composed of hydrocarbons such as light oil.
In addition, as a lubricating method using the lubricating oil composition for internal combustion engines which is one embodiment of the present invention, the lubricating oil composition for internal combustion engines which is one embodiment of the present invention is applied to an internal combustion engine such as an engine, for example. There is a method of filling and lubricating between the parts related to the internal combustion engine.

<Internal combustion engine>
The internal combustion engine which is one embodiment of the present invention is filled with the lubricating oil composition for an internal combustion engine of the present invention, and examples thereof include gasoline engines, diesel engines, gas engines and the like used for automobiles and the like. In particular, an internal combustion engine that is driven by burning fuel including biofuel is a suitable example.

<Method for producing lubricating oil composition>
A method for producing a lubricating oil composition according to an embodiment of the present invention includes a base oil containing at least a succinimide compound (A), a molybdenum compound (B), an overbased sodium sulfonate (C), and an overbase. It is a manufacturing method of the lubricating oil composition which mix | blends a basic calcium type detergent (D) and obtains a lubricating oil composition. Moreover, in this manufacturing method, it is preferable to mix | blend antioxidant (E) further and you may mix | blend a viscosity index improver (F) and another additive suitably.
Details of these components (A) to (F) and other additives, details of their blending amounts, and details of the resulting lubricating oil composition, details of each component described above, details of content, and lubricating oil composition Since it is the same as the detail of a thing, the description is abbreviate | omitted.

EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Various properties and the evaluation of the lubricating oil composition were determined according to the following procedure.

(1) Kinematic viscosity It is a value measured using a glass capillary viscometer according to JISK2283: 2000.
(2) Viscosity index It measured based on JISK2283: 2000.
(3) NOACK evaporation (250 ° C, 1 hour)
It is a value measured according to the method prescribed in ASTM D5800.
(4) Aromatic content (% C _A ) and paraffin content (% C _P )
This is a value measured by ring analysis (ndM method) of ASTM D-3238.
(5) Sulfur content This is a value measured in accordance with JIS K2541-6: 2003 “Crude oil and petroleum products—Sulfur content test method”.
(6) Base number It is measured by the perchloric acid method according to JIS K2501: 2003.
(7) Sulfated ash content This is a value measured according to JIS K2272: 1998.
(8) SRV reciprocating friction test Using a reciprocating friction tester (manufactured by Optimar, SRV reciprocating friction tester), the friction coefficient was measured by the following method. As a test piece, a SUJ-2 disk (φ24 mm × 7.9 mm) is used, and several drops of sample oil (lubricating oil composition) are dropped on it. The friction coefficient was measured under the conditions of a load of 400 N, an amplitude of 1.5 mm, a frequency of 50 Hz, and a temperature of 80 ° C. with a SUJ-2 cylinder (φ15 mm × 22 mm) set on the top of the disk.
(9) Biofuel addition IOT test In a glass test tube, 5 mass of biodiesel fuel B100 (80% RME (rapeseed oil methyl ester), 20% SME (soybean oil methyl ester), produced by Haltermann Solutions, Inc.) as a lubricating oil composition. % Sample oil added 100% and tris (2,4-pentanedionato) iron (III) 63.24 mg as a catalyst, air was blown at 160 ° C. at a flow rate of 10 L / h, and 168 hours oxidation deterioration I let you. The 100 degreeC kinematic viscosity of the sample oil before a test and the sample oil after a test was measured, and the 100 degreeC kinematic viscosity increase rate was calculated | required. The smaller the 100 ° C. kinematic viscosity increase rate, the better the oxidation stability.

Examples 1-8, Comparative Examples 1-8
In each example and comparative example, the lubricating oil composition shown in Table 1 was prepared, and the resulting lubricating oil composition was measured for sulfated ash, and an SRV reciprocating friction test and a biofuel addition IOT test were performed.

Each component in the table is as follows.
(Base oil)
・ Hydrorefined base oil: 100 ° C. kinematic viscosity 4.15 mm ² / s, viscosity index 133, sulfur content less than 5 mass ppm, NOACK evaporation 13.8 mass%,% C _A 0.1 or less,% C _P 89.5
Poly α-olefin: Durasyn 145 (manufactured by INEOS), kinematic viscosity at 100 ° C. 5.194 mm ² / s, viscosity index 145, NOACK evaporation 5.14% by mass
((A) component)
-Boron derivative of polybutenyl succinic acid monoimide (A1): polybutenyl group number average molecular weight 1000, nitrogen content 1.23 mass%, boron content 1.30 mass%, chlorine content, 0.06 mass%
Polybutenyl succinic acid bisimide (A2): number average molecular weight of polybutenyl group 2300, nitrogen content 0.99% by mass, chlorine content 0.01% by mass or less (component (B))
-Binuclear organic molybdenum compound (B1): SakuraLube 515 (manufactured by ADEKA Co., Ltd.), molybdenum content 10.0 mass%, sulfur content 11.5 mass%, R ¹¹ to R ¹⁴ each having 8 or 8 carbon atoms A dinuclear molybdenum dithiocarbamate / trinuclear organomolybdenum compound (B2) represented by formula (3) wherein X ¹ to X ⁴ are oxygen atoms: Infineum C9455B (manufactured by Infineum), represented by formula (4) Trinuclear molybdenum dithiocarbamate, molybdenum content 5.5% by mass, sulfur content 9.9% by mass
((C) component)
Overbased sodium sulfonate: base number (perchloric acid method) 448 mg KOH / g, sodium content 19.5 mass%, sulfur content 1.2 mass%
((D) component)
・ Overbased calcium salicylate (D1): base number (perchloric acid method) 225 mgKOH / g, calcium content 8.0 mass%, sulfur content 0.15 mass%
・ Overbased calcium phenate (D2): base number (perchloric acid method) 255 mgKOH / g, calcium content 9.3 mass%, sulfur content 3.0 mass%
((E) component)
Phenolic antioxidant (E1): C7-C9 alkyl ester of 3,5-bis (1,1-dimethylethyl) -4-hydroxybenzenepropanoic acid (trade name “IRGANOX® L135, manufactured by BASF AG) ")
Amine-based antioxidant (E2): bis (4-nonylphenyl) amine, nitrogen content 3.5% by mass
Viscosity index improver (F): styrene-isobutylene copolymer, mass average molecular weight 584,000, resin content 10% by mass
Other additives: zinc dialkyldithiophosphates, metal deactivators, pour point depressants, and antifoaming agents

As described above, in Examples 1 to 8, the components (A) to (D) are contained, and the content and ratio (A1 / A2) of the components (A) to (C) are set within a predetermined range. Thus, the intermetallic friction coefficient was lowered while the sulfated ash content was lowered, and the viscosity increase rate of the lubricating oil composition was suppressed in the biofuel addition IOT test. Therefore, it is understood that it is possible to suppress an increase in the viscosity of the lubricating oil even when biofuel is mixed into the lubricating oil composition, while reducing adverse effects on the exhaust gas purification device and improving fuel efficiency. it can.
In contrast, in Comparative Example 1, the components (A) to (D) were contained, and the contents of the components (A) to (C) were within a predetermined range, but the ratio (A1 / A2) was defined. Since it was not within the range, the rate of increase in viscosity of the lubricating oil composition could not be suppressed. Further, as in Comparative Examples 2 and 3, when the molybdenum-based compound (B) is not contained or the content is outside the specified range, both the intermetallic friction coefficient and the viscosity increase rate are reduced. I could not.
Further, in Comparative Examples 4 to 6, the overbased sodium sulfonate (component (C)) was not contained, or even if it was contained, the content thereof was small, so that an increase in the viscosity of the lubricating oil composition could be suppressed. There wasn't. This result was the same even when the amount of the overbased calcium-based detergent (component (D)) was increased instead of containing the component (C) as in Comparative Example 7. Further, in Comparative Example 8, the component (C) was not contained, and the ratio (A1 / A2) was also large, so that an increase in viscosity could not be suppressed.

Claims (15)

1. Base oil,
   At least one succinimide compound (A) selected from the group consisting of alkenyl or alkyl succinic acid monoimide and its boron derivative (A1), and alkenyl or alkyl succinic acid bisimide and its boron derivative (A2);
   At least one molybdenum-based compound (B) selected from the group consisting of a dinuclear organic molybdenum compound (B1) and a trinuclear organic molybdenum compound (B2);
   Overbased sodium sulfonate (C);
   Including at least one overbased calcium-based detergent (D) selected from the group consisting of overbased calcium salicylate (D1) and overbased calcium phenate (D2);
   The content of the component (A) is 550 mass ppm or more in terms of nitrogen atoms, the content of the component (B) is 200 mass ppm to 600 mass ppm in terms of molybdenum atoms, and the component (C). Content is 250 mass ppm or more in terms of sodium atom,
   The ratio [(A1 / A2)] of the content of the component (A1) in terms of nitrogen atom and the content of the component (A2) in terms of nitrogen atom is 0 or more and 0.3 or less, and the sulfated ash content is The lubricating oil composition for an internal combustion engine, which is 0.8% by mass or less.
2. The at least 1 sort (s) of antioxidant (E) selected from the group which consists of a phenolic antioxidant and an amine antioxidant contains 1.0 mass% or more on the basis of the total amount of lubricating oil composition. A lubricating oil composition for internal combustion engines.
3. The lubricating oil composition for an internal combustion engine according to claim 1 or 2, wherein the base oil comprises mineral oil and synthetic oil.
4. The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 3, wherein the base oil contains a poly α-olefin.
5. The lubricating oil composition for internal combustion engines according to any one of claims 1 to 4, wherein the succinimide compound (A) comprises a boron derivative of alkenyl or alkyl succinic monoimide.
6. The lubricating oil composition for an internal combustion engine according to claim 5, wherein the boron content derived from the component (A1) is 50 mass ppm or more and 300 mass ppm or less based on the total amount of the lubricating oil composition.
7. The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 6, wherein the component (A2) comprises alkenyl or alkyl succinic acid bisimide.
8. 8. The alkenyl or alkyl succinic acid monoimide is a compound represented by the following formula (1), and the alkenyl or alkyl succinic acid bisimide is a compound represented by the following formula (2). The lubricating oil composition for an internal combustion engine according to Item.
   

   

   
   (In the formula, R ¹ , R ³ and R ⁴ are each an alkenyl group or an alkyl group, R ³ and R ⁴ may be the same or different from each other, and R ² , R ⁵ and R ⁶ are each a carbon number. 2 to 5 alkylene groups, R ⁵ and R ⁶ may be the same or different from each other, r represents an integer of 1 to 10, and s represents 0 or an integer of 1 to 10. R ¹ , The number average molecular weights of R ³ and R ⁴ are 500 or more and 3000 or less, respectively.
9. The internal combustion engine according to any one of claims 1 to 8, wherein the dinuclear organic molybdenum compound (B1) is a dinuclear molybdenum dithiocarbamate and the trinuclear organic molybdenum compound (B2) is a trinuclear molybdenum dithiocarbamate. Lubricating oil composition for engines.
10. The lubricating oil composition for internal combustion engines according to any one of claims 1 to 9, wherein the base number of the overbased sodium sulfonate (C) is 200 mgKOH / g or more.
11. The lubricating oil composition for internal combustion engines according to any one of claims 1 to 10, wherein the content of component (D) is 500 mass ppm or more and 1500 mass ppm or less in terms of calcium atom, based on the total amount of the lubricating oil composition. .
12. The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 11, wherein the overbased calcium-based detergent (D) is an overbased calcium salicylate.
13. The lubricating oil composition for internal combustion engines according to any one of claims 1 to 12, wherein the base number of the overbased calcium detergent (D) is 150 mgKOH / g or more.
14. The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 13, which is used in an internal combustion engine driven by burning a fuel containing biofuel.
15. Base oil,
    At least one succinimide compound (A) selected from the group consisting of alkenyl or alkyl succinic acid monoimide and its boron derivative (A1), and alkenyl or alkyl succinic acid bisimide and its boron derivative (A2),
    At least one molybdenum-based compound (B) selected from the group consisting of a dinuclear organic molybdenum compound (B1) and a trinuclear organic molybdenum compound (B2);
    Overbased sodium sulfonate (C), and at least one overbased calcium detergent (D) selected from the group consisting of overbased calcium salicylate (D1) and overbased calcium phenate (D2) A method for producing a lubricating oil composition for an internal combustion engine, wherein a lubricating oil composition is obtained by blending
    The blending amount of the component (A) on the basis of the total amount of the lubricating oil composition is 550 mass ppm or more in terms of nitrogen atoms, the blending amount of the component (B) is 200 to 600 ppm in terms of molybdenum atoms, and the component (C) The blending amount is 250 mass ppm or more in terms of sodium atom,
    The ratio [(A1 / A2)] of the blending amount of the component (A1) in terms of nitrogen atoms and the blending amount of the component (A2) in terms of nitrogen atoms is 0 or more and 0.3 or less, and the sulfated ash content is The manufacturing method of the lubricating oil composition for internal combustion engines which is 0.8 mass% or less.