JP6507455B2 - Lubricating oil composition - Google Patents

Description

  The present invention relates to a lubricating oil composition used for an internal combustion engine such as a diesel engine, a gasoline engine, a gas engine, and an engine for a hybrid vehicle.

At present, environmental regulations on a global scale are becoming increasingly severe, and the circumstances surrounding automobiles are also becoming stricter, such as fuel consumption regulations and emission gas regulations. This background includes environmental problems such as global warming and resource protection from concerns about the exhaustion of petroleum resources. For the above reasons, fuel efficiency of automobiles is further desired.
When aiming at high output of automobile engines, the combustion temperature and pressure in the engines tend to increase. In particular, in a diesel engine, it is necessary to design the engine robustly because resistance and rigidity at high temperatures, heat crack resistance and the like are required. However, in order to reduce fuel consumption, weight reduction of the engine is required.
Therefore, conventionally, an aluminum alloy such as JIS AC 8A has been used as a piston for a diesel engine in order to reduce the weight. Further, a lubricating oil composition suitable for lubricating a diesel engine using an aluminum alloy has been developed (see, for example, Patent Document 1).

JP, 2010-10070, A

However, since pistons made of aluminum alloy have a thermal and mechanical durability temperature of about 350 ° C. and a large amount of thermal expansion, among the improvements to meet the recent demand for higher output and lower fuel consumption of automobile engines In place of aluminum alloys, cast iron pistons having thermal and mechanical endurance temperatures up to about 400 ° C. are partially employed.
Cast iron pistons are more durable than pistons made of aluminum alloy, and because graphite contained in cast iron has a self-lubricating property, it is also excellent in seizure resistance. However, cast iron pistons are likely to cause deterioration of engine performance because they are large in wear and inferior in cleanliness due to the high temperature near the piston top dead center compared to aluminum alloys.
Therefore, the present invention can prevent engine performance degradation even when used in an internal combustion engine for vehicles that can achieve higher output and lower fuel consumption by increasing the thermal and mechanical durability temperature more than before, and the engine performance and the engine It is an object of the present invention to provide a lubricating oil composition compatible with the durability of

  As a result of intensive studies, the inventor of the present invention can solve the above-mentioned problems by mixing them under specific conditions in a lubricating oil composition having a base oil, a dispersant and a metallic detergent. The present invention has been completed.

  That is, the lubricating oil composition according to the present invention comprises at least one selected from mineral oil and synthetic oil, a base oil having a viscosity index of 120 or more and a paraffin content by ring analysis of 70% or more (A ) A dispersant containing one or more compounds selected from alkenyl succinimides, borides of alkenyl succinimides, alkyl succinimides, and borides of alkyl succinimides; (B) Alkali metal sulfonates, alkalis Component (A), which has a metal-based detergent containing one or more compounds selected from metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates Is 0.01 mass% or more and 0.10 mass% or less in nitrogen content conversion based on the total composition Rare, component (B) is contained in an amount of 0.01% by mass or more and 0.3% by mass or less in terms of metal content in terms of the total amount of the composition, and boride of the alkenyl succinimide in the component (A) and alkylsuccinic acid Containing one or more compounds selected from borides of imide, and having a B / N ratio of 0.5 or more, which is a mass ratio of boron to nitrogen contained in the component (A), and containing phosphorus based on the total amount of the composition The amount is 100 mass ppm or more and 1200 mass ppm or less, and the sulfated ash content in the total amount of the composition is 1.1 mass% or less.

  Further, a method for producing a lubricating oil composition according to the present invention is a base oil containing at least one selected from mineral oil and synthetic oil, having a viscosity index of 120 or more, and having a paraffin content by ring analysis of 70% or more. A dispersant containing at least one compound selected from (A) alkenyl succinimides, borides of alkenyl succinimides, alkyl succinimides, and borides of alkyl succinimides, and (B) an alkali metal (A) a metallic detergent comprising one or more compounds selected from sulfonates, alkali metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates; Is 0.01 mass% or more and 0.10 mass% or less in nitrogen content conversion based on the total composition Rare, component (B) is contained in an amount of 0.01% by mass or more and 0.3% by mass or less in terms of metal content in terms of the total amount of the composition, and boride of the alkenyl succinimide in the component (A) and alkylsuccinic acid Containing one or more compounds selected from borides of imide, B / N ratio which is a mass ratio of boron to nitrogen contained in the component (A) is 0.5 or more, and contains phosphorus on the basis of the total amount of the composition A method of producing a lubricating oil composition for producing a lubricating oil composition by blending so that the amount is 100 mass ppm or more and 1200 mass ppm or less and the sulfated ash content in the total amount of the composition is 1.1 mass% or less is there.

  According to the present invention, engine performance and engine performance can be prevented even when used in an automotive internal combustion engine that can achieve higher output and lower fuel consumption by increasing the thermal and mechanical durability temperature more than before, and the engine performance and the engine It is possible to provide a lubricating oil composition compatible with the durability of the above.

[Lubricating oil composition]
The lubricating oil composition according to the present invention contains at least one selected from mineral oil and synthetic oil, a base oil having a viscosity index of 120 or more, and a paraffin content by ring analysis of 70% or more; A dispersant containing at least one compound selected from succinimide, alkenyl succinimide boride, alkyl succinimide, and alkyl succinimide boride; (B) alkali metal sulfonate, alkali metal phenate And a metallic detergent comprising at least one compound selected from alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates.
The component (A) is contained in an amount of 0.01% by mass or more and 0.10% by mass or less in terms of nitrogen content in terms of total composition, and the component (B) is 0.01% in terms of metal content in terms of total composition % Or more and 0.3 mass% or less are contained.
In addition, at least one compound selected from the boride of the alkenyl succinimide and the boride of the alkyl succinimide in the component (A) is included, and the mass ratio of boron to nitrogen contained in the component (A) A certain B / N ratio is 0.5 or more. Furthermore, in the lubricating oil composition, the phosphorus content on the basis of the total amount of the composition is 100 mass ppm or more and 1200 mass ppm or less, and the sulfated ash content on the basis of the total amount of the composition is 1.1 mass% or less. The lubricating oil composition according to the present invention may be hereinafter simply referred to as "the present composition".

[Base oil]
The base oil of the present composition may be mineral oil or synthetic oil. There is no restriction | limiting in the kind of this mineral oil and a synthetic oil, Arbitrary thing can be suitably selected and used out of the mineral oil and synthetic oil which are conventionally used as a base oil of lubricating oil composition.
As a mineral oil, for example, a lubricating oil fraction obtained by vacuum-distilling an atmospheric residue obtained by atmospheric distillation of crude oil is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic removal Examples include mineral oil refined by performing one or more treatments such as wax, hydrorefining, or wax, mineral oil produced by isomerizing GTL WAX, and the like.
As synthetic oils, for example, polybutene, polyolefin [α-olefin homopolymer or copolymer (eg ethylene-α-olefin copolymer), etc.], various esters (eg, polyol ester, dibasic acid ester, phosphorus, etc.) Examples include acid esters and the like, various ethers (eg, polyphenyl ether and the like), polyglycols, alkylbenzenes, alkylnaphthalenes and the like. Among these synthetic oils, polyolefins and polyol esters are particularly preferable in view of viscosity characteristics, solubility of additives and compatibility with seal rubber.
In the present invention, the above mineral oils may be used alone or in combination of two or more. Moreover, 1 type of the said synthetic oil may be used and you may use combining 2 or more types. Furthermore, one or more types of mineral oils and one or more types of synthetic oils may be used in combination.
The viscosity of the base oil is not particularly limited, and can be selected according to the application of the lubricating oil composition. The viscosity of the base oil, kinematic viscosity at 100 ° C., usually, 2 mm ² / s or more 30 mm ² / s or less, preferably 3 mm ² / s or more 15 mm ² / s or less, particularly preferably 4 mm ² / s or more 10 mm ² / s or less. When the kinematic viscosity at 100 ° C. is 2 mm ² / s or more, evaporation loss is small, and when it is 30 mm ² / s or less, power loss due to viscous resistance is suppressed, and a fuel consumption improvement effect is obtained.

In addition, the base oil has a paraffin content (sometimes described as% CP) by ring analysis of 70% or more. If the% CP is less than 70%, the oxidation stability is poor, and the increase in acid value and the generation of sludge tend to occur. From the above viewpoint,% CP is preferably 80% or more.
Furthermore, the viscosity index of the base oil is 120 or more. Preferably, it is 125 or more, more preferably 130 or more. The base oil having a viscosity index of less than 120 has a large change in viscosity due to a change in temperature, and the fuel efficiency improvement effect at low temperatures is reduced.

[(A) component]
The component (A) is a dispersant including one or more compounds selected from alkenyl succinimide, boride of alkenyl succinimide, alkyl succinimide, and boride of alkyl succinimide.
Component (A) is a boride of alkenyl succinimide among one or more compounds selected from alkenyl succinimides, borides of alkenyl succinimides, alkyl succinimides, and borides of alkyl succinimides. Alternatively, either one of alkyl succinimide borides is essential. When the component (A) contains a boride of alkenyl succinimide or alkyl succinimide, high-temperature cleaning is enhanced.
In the present embodiment, succinimide comprises a monoimide structure and a bisimide structure.
The monoimide structure includes both a structure based on an alkenyl or alkylsuccinic acid monoimide alone and a structure based on a boride of an alkenyl or alkylsuccinic acid monoimide. Examples of alkenyl or alkylsuccinic acid monoimides include alkenyl or alkylsuccinic acid monoimides represented by the following formula (1).
Similarly, the bisimide structure includes both a structure based on an alkenyl or alkyl succinate bisimide alone and a structure based on a boride of an alkenyl or alkyl succinate bisimide. Examples of alkenyl or alkyl succinic acid bisimides include alkenyl or alkyl succinic acid bisimides represented by the following formula (2).

In the above formulas (1) and (2), R ¹ , R ³ and R ⁴ are an alkenyl group or an alkyl group, and the mass average molecular weight is preferably 500 or more and 3,000 or less, more preferably 1 It is more than 3,000 and less than 3,000.
When the mass average molecular weight of the above R ¹ , R ³ and R ⁴ is 500 or more, the solubility in the base oil becomes high, and when it is 3,000 or less, the effect of cleanliness can be expected. 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 5 carbon atoms, and R ⁵ and R ⁶ may be the same or different. m represents an integer of 1 to 10, and n represents an integer of 0 or 1 to 10. Here, m is preferably 2 to 5, more preferably 3 to 4. When m is 2 or more, better high-temperature cleaning can be provided, and when m is 5 or less, the solubility in a base oil is further improved.
In the above formula (2), n is preferably 1 to 4, and more preferably 2 to 3. Unlike monoimide, when n is 1 or more, the high-temperature cleaning property is further improved, and when n is 4 or less, the solubility in a base oil is further improved.

  Examples of the alkenyl group include polybutenyl group, polyisobutenyl group and ethylene-propylene copolymer, and examples of the alkyl group include those obtained by hydrogenating these. Suitable alkenyl groups include polybutenyl or polyisobutenyl groups. The polybutenyl group is preferably obtained as a mixture of 1-butene and isobutene or as a polymerized product of high purity isobutene. Moreover, as a representative example of a suitable alkyl group, what hydrogenated the polybutenyl group or the polyisobutenyl group is mentioned.

  The above alkenyl or alkyl succinimide is generally reacted with a polyamine with an alkenyl succinic anhydride obtained by the reaction of a polyolefin and maleic anhydride, or an alkyl succinic anhydride obtained by hydrogenating the same. It can be manufactured by Moreover, the above-mentioned succinic acid monoimide and succinic acid bisimide can be produced by changing the reaction ratio of alkenyl succinic anhydride or alkyl succinic anhydride and polyamine.

As an olefin monomer which forms said polyolefin, although 1 type, or 2 or more types of C2-C8 alpha olefin can be mixed and used, it is used, The mixture of isobutene and 1-butene is used suitably be able to.
On the other hand, as polyamines, single diamines such as ethylenediamine, propylenediamine, butylenediamine and pentylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di (methylethylene) triamine, dibutylenetriamine and triamine Mention may be made of butylene tetramine, and polyalkylene polyamines such as pentapentyl hexamine, and piperazine derivatives such as aminoethyl piperazine.

Moreover, the boride of alkenyl or alkyl succinimide can use what was manufactured by the conventional method.
For example, after reacting the above-mentioned polyolefin with maleic anhydride to form alkenyl succinic anhydride, the above-mentioned polyamine and boron oxide, boron halide, boric acid, boric acid anhydride, boric acid ester, ammonium of boric acid It is obtained by imidization by reacting with an intermediate obtained by reacting a boron compound such as a salt.

  Here, in the component (A), the mass ratio (Nm / Nb) of the nitrogen derived from the monoimide structure to the nitrogen derived from the bisimide structure is 0.5 or less, preferably 0.4 or less. When the mass ratio (Nm / Nb) is 0.5 or less, the durability of the engine can be improved.

  One or more compounds selected from alkenyl succinimides, borides of alkenyl succinimides, alkyl succinimides, and borides of alkyl succinimides in component (A) have a nitrogen content based on the total amount of the composition 0.01 mass% or more and 0.10 mass% or less are contained in conversion. More preferably, it is 0.02 mass% or more and 0.09 mass% or less, still more preferably 0.03 mass% or more and 0.08 mass% or less. If this compound is less than 0.01% by mass in terms of nitrogen content, the high-temperature cleaning properties deteriorate, and if it exceeds 0.10% by mass, the oxidation stability becomes worse.

  The mass ratio (B / N ratio) of boron to nitrogen constituting the boride of alkenyl or alkyl succinimide in the component (A) is 0.5 or more, preferably 0.6 or more, more preferably It is 0.8 or more. When the B / N ratio is 0.5 or more, the high temperature cleanliness is greatly improved.

  When a certain amount or more of the boron content derived from the boride of alkenyl or alkyl succinimide in the component (A) is present, high-temperature cleanliness is exhibited. When the boron content derived from the boride of the alkenyl or alkyl succinimide in the component (A) is 0.01% by mass or more and 0.06% by mass or less based on the total mass of the composition, sufficient high-temperature cleaning is obtained can get. Preferably, it is 0.02 mass% or more and 0.05 mass% or less.

[(B) component]
Component (B) of the lubricating oil composition according to the present invention is one selected from alkali metal sulfonates, alkali metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates. It is a metal detergent containing the above compounds. Among these, the component (B) is preferably at least one of an alkali metal sulfonate and an alkaline earth metal sulfonate.

Examples of the alkaline earth metal sulfonate include alkaline earth metal salts of alkylaromatic sulfonic acids obtained by sulfonation of alkylaromatic compounds having a molecular weight of 300 to 1,500, preferably 400 to 700. In particular, magnesium salts, calcium salts and the like are mentioned, and among them, calcium salts are preferably used.
Examples of the alkaline earth metal phenate include alkylphenols, alkylphenol sulfides, alkaline earth metal salts of Mannich reaction products of alkylphenols, in particular, magnesium salts, calcium salts and the like, among which calcium salts are preferably used.
Examples of the alkaline earth metal salicylate include alkaline earth metal salts of alkylsalicylic acids, in particular, magnesium salts, calcium salts and the like, among which calcium salts are preferably used.
The alkyl group constituting the alkaline earth metal detergent is preferably an alkyl group having 4 to 30 carbon atoms, more preferably an alkyl group of 6 to 18, and these may be linear or branched. They may also be primary alkyl groups, secondary alkyl groups or tertiary alkyl groups.

  Also, for the alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate, the aforementioned alkyl aromatic sulfonic acid, alkyl phenol, alkyl phenol sulfide, Mannich reaction product of alkyl phenol, alkyl salicylic acid, etc. from magnesium and calcium Neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earths obtained by direct reaction with an alkaline earth metal base such as an oxide or hydroxide of one or more selected alkaline earth metals Such metals include salicylates.

  In addition, as the alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate, the aforementioned alkyl aromatic sulfonic acid, alkyl phenol, alkyl phenol sulfide, Mannich reaction product of alkyl phenol, alkyl salicylic acid and the like, sodium salt And neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earth metal salicylates obtained by substituting the alkaline earth metal salts as alkali metal salts such as potassium salts.

  Further, for alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate, neutral alkaline earth metal sulfonate, neutral alkaline earth metal phenate and neutral alkaline earth metal salicylate, and excess alkali Basic alkaline earth metal sulfonates, basic alkaline earth metal phenates and basic alkaline earth metal salicylates obtained by heating an earth metal salt or alkaline earth metal base in the presence of water are included.

Furthermore, alkaline earth metal sulfonates, alkaline earth metal phenates and alkaline earth metal salicylates include neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earths in the presence of carbon dioxide gas. Also included are overbased alkaline earth metal sulfonates obtained by reacting metal salicylates with alkaline earth metal carbonates or borates, overbased alkaline earth metal phenates and overbased alkaline earth metal salicylates Be
The alkaline earth metal sulfonate, the alkaline earth metal phenate and the alkaline earth metal salicylate can be used in combination of one or more selected from those described above.

  As the metal detergent, the above-mentioned neutral salts, basic salts, overbased salts and mixtures thereof may be used, and in particular, one of overbased salicylates, overbased phenates and overbased sulfonates. A mixture of the above with a neutral sulfonate is preferable in terms of the cleanliness inside the engine and the wear resistance. Metal-based detergents are generally commercially available as diluted with light lubricating base oils and the like. It is desirable to use a metal detergent having a metal content of 1.0% by mass or more and 20% by mass or less, preferably 2.0% by mass or more and 16% by mass or less.

  The base number of the component (B) is preferably 10 mg KOH / g or more and 600 mg KOH / g or less, more preferably 20 mg KOH / g or more and 500 mg KOH / g or less. The term "total base number" as used herein is defined in JIS K 2501 "Petroleum products and lubricants-Test method for neutralization number". It means the total base number by potentiometric titration method (base number · perchloric acid method) measured according to

  Further, the metal ratio contained in the component (B) is not particularly limited, and usually, one having 20 or less may be used alone or as a mixture of two or more. Preferably, the metal ratio is 3 or less, more preferably 1. It is particularly preferable to use a metal-based detergent of 5 or less, particularly preferably 1.2 or less, as an essential component, because it is excellent in oxidation stability, base number maintenance and high-temperature cleanliness. The metal ratio referred to here is represented by the valence number of the metal element in the metal detergent × metal element content (mol%) / sane base content (mol%), and the metal element is calcium, magnesium, etc. The soap group means a sulfonic acid group, a phenol group, a salicylic acid group and the like.

In the lubricating oil composition according to the present invention, in order to reduce the sulfated ash content to 1.1% by mass or less, the component (B) is preferably 0.3% by mass or less. Moreover, the compounding quantity of (B) component is 0.01 mass% or more and 0.3 mass% or less in conversion of the metal content in the composition whole quantity basis.
Further, from the viewpoint of reducing the sulfated ash content of the lubricating oil composition to 1.1% by mass or less, more preferably sodium sulfonate is added to the component (B) in an amount of 0. 0 metal based on the total amount of the lubricating oil composition. It is to be contained at less than 05% by mass. Alternatively, magnesium sulfonate is contained in an amount of 0.05% by mass or less of the metal based on the total amount of the lubricating oil composition.
In the lubricating oil composition according to the present invention, the sulfur content is preferably 0.3% by mass or less on the basis of the total amount of the composition, more preferably 0.2% by mass or less, and still more preferably 0. It is 1 mass% or less. The performance fall of the purification catalyst of exhaust gas can be effectively suppressed as sulfur content is 0.3 mass% or less.

[(C) ingredient]
In the present composition, zinc dialkyl dithiophosphate (hereinafter also referred to as "ZnDTP") is preferably blended as component (C). As (C) component, ZnDTP shown by following formula (3) is mentioned, for example.

In the above formula (3), R ¹¹ , R ¹² , R ¹³ and R ^{14 each} represents an alkyl group substituted with a primary or secondary alkyl group having 3 to 22 carbon atoms or an alkyl group having 3 to 18 carbon atoms Substituents selected from aryl groups, which may be identical to or different from one another.

In the present invention, one of these ZnDTPs may be used alone, or two or more of them may be used in combination, and in particular, zinc dithiophosphate having a secondary alkyl group as a main component It is preferable to increase the abrasion resistance.
Specific examples of ZnDTP include zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl dithiophosphate, zinc dihexyl dithiophosphate, zinc diisopentyl dithiophosphate, zinc diethylhexyl dithiophosphate, zinc dioctyl dithiophosphate, dinonyl dithiophosphate Zinc, zinc didecyl dithiophosphate, zinc didodecyl dithiophosphate, zinc dipropylphenyl dithiophosphate, zinc dipentylphenyl dithiophosphate, zinc dipropylmethylphenyl dithiophosphate, zinc dinonylphenyl dithiophosphate, zinc didodecylphenyl dithiophosphate, And zinc dodecylphenyl dithiophosphate.

[Other ingredients]
The lubricating oil composition according to the present invention may, if necessary, be an antioxidant, a viscosity index improver, a pour point depressant, a rust inhibitor, a metal deactivator, insofar as the effects of the present invention are not impaired. Antifoaming agents, antiwear agents, extreme pressure agents and other additives may be added.
<Antioxidant>
As an antioxidant, an antioxidant such as phenol type or amine type can be used.
As a phenolic antioxidant, for example, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate; 4,4'-methylenebis (2,6-di-t-butylphenol); 4,4'-bis (2,6-di-tert-butylphenol); 4,4'-bis (2-methyl-6-tert-butylphenol); 2,2'-methylenebis (4-ethyl-6-t) -Butylphenol); 2,2'-methylenebis (4-methyl-6-t-butylphenol); 4,4'-butylidenebis (3-methyl-6-t-butylphenol); 4,4'-isopropylidenebis (2 2, 6-di-t-butylphenol); 2,2'-methylenebis (4-methyl-6-nonylphenol); 2,2'-isobutylidenebis (4,6-dimethylphenol); 2,6-di-tert-butyl-4-methylphenol; 2,6-di-tert-butyl-4-ethylphenol; 2,4-dimethyl -'- methylenebis (4-methyl-6-cyclohexylphenol); 2,6-di-tert-amyl-p-cresol; 2,6-di-tert-butyl-4- (N, N′-dimethylaminomethylphenol); 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-tert-butylbenzyl) sulfide; bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide; n-octyl-3- (4-hydroxy-3,5) - Di-t-butylphenyl) propionate, n-octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate; 2,2'-thio [diethyl-bis-3- (3,5) -Di-t-butyl-4-hydroxyphenyl) propionate] and the like. Among these, those of bisphenol type and ester group-containing phenol type are particularly preferable.

  Examples of amine antioxidants include monoalkyldiphenylamines such as monooctyldiphenylamine and monononyldiphenylamine; 4,4'-dibutyldiphenylamine, 4,4'-dipentyldiphenylamine, 4,4'-dihexyldiphenylamine, And dialkyldiphenylamines such as 4,4'-diheptyldiphenylamine, 4,4'-dioctyldiphenylamine and 4,4'-dinonyldiphenylamine; polyalkyldiphenylamines such as tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine and tetranonyldiphenylamine And naphthylamines, specifically α-naphthylamine, phenyl-α-naphthylamine, and further butylphenyl-α Naphthylamine, pentylphenyl -α- naphthylamine, hexylphenyl -α- naphthylamine, heptylphenyl -α- naphthylamine, octylphenyl -α- naphthylamine, alkyl-substituted phenyl -α- naphthylamine, such as nonylphenyl -α- naphthylamine. Among these, diphenylamines are preferred to naphthylamines from the viewpoint of the antioxidant effect.

In the present invention, a molybdenum amine antioxidant may be further added. Molybdenum amine-based antioxidants include hexavalent molybdenum compounds, specifically, those obtained by reacting molybdenum trioxide and / or molybdic acid with an amine compound, for example, the production described in JP-A No. 2003-252887. The compounds obtained by the method can be used.
The amine compound to be reacted with the hexavalent molybdenum compound is not particularly limited. Specifically, monoamines, diamines, polyamines and alkanolamines can be mentioned. More specifically, it has an alkyl group having 1 to 30 carbon atoms such as methylamine, ethylamine, dimethylamine, diethylamine, methylethylamine and methylpropylamine (these alkyl groups may be linear or branched). Alkyl amines; alkenyl amines having alkenyl groups having 2 to 30 carbon atoms such as ethenyl amines, propenyl amines, butenyl amines, octenyl amines and oleyl amines (these alkenyl groups may be linear or branched); methanolamine, ethanolamine , An alkanolamine having an alkanol group having 1 to 30 carbon atoms such as methanolethanolamine or methanolpropanolamine (these alkanol groups may be linear or branched); methylenediamine, ethylenediamine, propylene And alkylenediamines having an alkylene group having 1 to 30 carbon atoms such as butylenediamine; polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine; undecyldiethylamine, undecyldiethanolamine, dodecyldipropanolamine The above monoamines such as oleyl diethanolamine, oleyl propylene diamine and stearyl tetraethylene pentamine, diamines, compounds having an alkyl group or alkenyl group having 8 to 20 carbon atoms in the polyamine, heterocyclic compounds such as imidazoline; alkylene oxides of these compounds Additives; and mixtures thereof can be exemplified. Moreover, the sulfur-containing molybdenum complex of the succinimide described in Japanese Patent Publication No.3-22438 and Unexamined-Japanese-Patent No. 2004-2866 etc. can be illustrated.

  The blending amount of the above-mentioned antioxidant is preferably 0.3% by mass or more and 3% by mass or less based on the total amount of the composition from the viewpoint of compatibility with the base oil. Moreover, 0.4 to 3 mass% is more preferable, 0.4 to 2 mass% is more preferable, and 0.5 to 2 mass% is particularly preferable. If the antioxidant is 0.3% by mass or more based on the total amount of the composition, the increase in acid value can be suppressed, and if it is 3% by mass or less, the solubility in a lubricating oil base oil can be secured.

<Viscosity Index Improver>
As a viscosity index improver, for example, polymethacrylates, dispersed polymethacrylates, olefin copolymers (eg, ethylene-propylene copolymer etc.), dispersed olefin copolymers, styrene copolymers (eg, Styrene-diene copolymer, styrene-isoprene copolymer, etc. are mentioned. The compounding amount of these viscosity index improvers is 0.5% by mass or more and 15% by mass or less, preferably 1% by mass or more and 10% by mass or less, based on the total amount of the composition, from the viewpoint of the compounding effect.

Pour point depressant
Examples of pour point depressants include ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polymethacrylate, polyalkylstyrene, etc. Polymethacrylates having a molecular weight of 5,000 or more and 50,000 or less are preferably used. These are used in a ratio of 0.1% by mass or more and 5% by mass or less based on the total amount of the composition.

<Antirust agent>
Examples of the rust inhibitor include petroleum sulfonate, alkyl benzene sulfonate, dinonyl naphthalene sulfonate, alkenyl succinic acid ester, polyhydric alcohol ester and the like. The compounding amount of these rust inhibitors is 0.01% by mass or more and 1% by mass or less, preferably 0.05% by mass or more and 0.5% by mass or less based on the total amount of the composition from the viewpoint of the compounding effect. .

<Metal deactivator>
Examples of the metal deactivator (copper corrosion inhibitor) include benzotriazole, tolyltriazole, thiadiazole, imidazole and pyrimidine compounds. Among these, benzotriazole compounds are preferable. By blending a metal deactivator, metal corrosion and oxidation deterioration of engine parts can be suppressed. The compounding amount of these metal deactivators is preferably 0.01% by mass or more and 0.1% by mass or less, more preferably 0.03% by mass or more, based on the total amount of the composition from the viewpoint of the compounding effect. It is .05 mass% or less.

<Antifoam>
Examples of the antifoaming agent include silicone oil, fluorosilicone oil and fluoroalkyl ether etc. From the point of balance of defoaming effect and economy, etc., 0.005% by mass or more and 0.1% by mass based on the total amount of the composition It is preferable to blend% or less.

<Antiwear agent or extreme pressure agent>
Antiwear agents or extreme pressure agents include zinc dithiophosphate, zinc phosphate, zinc dithiocarbamate, molybdenum dithiocarbamate, molybdenum dithiophosphate, disulfides, sulfurized olefins, sulfurized oils and fats, sulfurized esters, thiocarbonates, thio Sulfur-containing compounds such as carbamates and polysulfides; Phosphorous esters, phosphoric esters, phosphonic esters, and phosphorus-containing compounds such as amine salts or metal salts thereof; thiophosphorous esters, thiophosphoric acid And sulfur and phosphorus containing antiwear agents such as esters, thiophosphonates, and their amine or metal salts.
When other antiwear agents or extreme pressure agents are compounded as necessary, the amount of other antiwear agents or extreme pressure agents is 600 mass ppm or less in terms of element as zinc based on the total amount of the lubricating oil composition is there. Preferably, it is 0 mass ppm or more and 500 mass ppm or less, more preferably 0 mass ppm or more and 400 mass ppm or less.
In addition, the blending amount of the other antiwear agent or extreme pressure agent is 500 mass ppm or less in terms of element as phosphorus in terms of the total amount of the lubricating oil composition. Preferably, it is 0 mass ppm or more and 400 mass ppm or less, more preferably 0 mass ppm or more and 300 mass ppm or less. If the blending amount of zinc is 600 mass ppm or less and the blending amount of phosphorus is 500 mass ppm or less, for example, the basic compound in the engine oil is consumed in the lubricating oil composition, and the oil change period becomes extremely short. There is no

<Phosphorous content of lubricating oil composition and sulfated ash content>
In the lubricating oil composition according to the present invention, the phosphorus content based on the total amount of the composition is 100 mass ppm or more and 1200 mass ppm or less. If the said phosphorus content is less than 100 mass ppm, abrasion resistance will become inadequate. On the other hand, when the phosphorus content exceeds 1200 mass ppm, poisoning of the exhaust gas on the purification catalyst can not be sufficiently suppressed.
The phosphorus content is preferably 200 mass ppm or more and 1100 mass ppm or less, more preferably 300 mass ppm or more and 1000 mass ppm or less, and particularly preferably 400 mass ppm or more and 900 mass ppm or less.
In the lubricating oil composition according to the present invention, the sulfated ash content on the basis of the total amount of the composition is 1.1% by mass or less. When the sulfated ash content exceeds 1.1% by mass, in the diesel engine, the amount of ash deposited on the filter of the DPF increases, the ash clogging of the DPF filter tends to occur, and the life of the DPF filter becomes short.
The sulfated ash content is more preferably 0.2% by mass or more, particularly preferably 0.3% by mass or more, from the viewpoint of further enhancing the oxidation stability, the base number maintenance property, and the high temperature cleanliness of the lubricating oil composition. This makes it possible to obtain a composition capable of maintaining the base number and the high-temperature cleaning property for a longer period of time.
The sulfated ash content refers to ash which is obtained by adding sulfuric acid to a carbonized residue produced by burning a sample and heating it to a constant weight, and in order to generally know the approximate amount of metal additive in the lubricating oil composition Used for Specifically, JIS K 2272 [5. It is measured according to the method specified in the test method for sulfated ash content].

  The lubricating oil composition according to the present invention is excellent not only in high-temperature cleanliness but also in compatibility with fluorine rubber seals frequently used in the engine interior, so gasoline engines, diesel engines, gas engines and engines for hybrid vehicles Etc. can be suitably used for internal combustion engines. Examples of internal combustion engines include general internal combustion engines manufactured using materials such as aluminum alloy materials, nickel chromium alloy materials, carbon steel materials, chromium molybdenum steel materials, etc. However, the lubricating oil composition according to the present invention In particular, it can be suitably used for the lubrication of an internal combustion engine where at least the piston head is made of cast iron material.

[Method of producing lubricating oil composition]
A method for producing a lubricating oil composition according to this embodiment is a base oil containing at least one selected from a mineral oil and a synthetic oil, having a viscosity index of 120 or more, and having a paraffin content by ring analysis of 70% or more. (A) A dispersant comprising at least one compound selected from alkenyl succinimides, borides of alkenyl succinimides, alkyl succinimides, and borides of alkyl succinimides, and (B) alkali metal sulfonates And (A) a metallic detergent comprising one or more compounds selected from alkali metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates 0.01 mass% or more and 0.10 mass% or less in nitrogen content conversion based on the whole composition basis Component (B) is contained in an amount of 0.01% by mass or more and 0.3% by mass or less in terms of metal content in terms of the total amount of the composition, and boride of the alkenyl succinimide in the component (A) and alkylsuccinic acid Containing one or more compounds selected from borides of imide, and having a B / N ratio of 0.5 or more, which is a mass ratio of boron to nitrogen contained in the component (A), and containing phosphorus based on the total amount of the composition A method of producing a lubricating oil composition by blending so that the amount is 100 mass ppm or more and 1200 mass ppm or less and the sulfated ash content in the total amount of the composition is 1.1 mass% or less is there.

  Further, the method for producing a lubricating oil composition according to the present embodiment further comprises, if necessary, an antioxidant, a viscosity index improver, a pour point depressant, a rust inhibitor, and a metal nonbasic agent, as needed. It contains an activator, an antifoamer, an antiwear agent, an extreme pressure agent, and other additives.

  As described above, the base oil contains the components (A) and (B), and, if necessary, an antioxidant, a viscosity index improver, a pour point depressant, a rust inhibitor, metal inactivity Lubricating oil compositions prepared by blending an additive, an antifoaming agent, an antiwear agent, an extreme pressure agent, and other additives contain the various additives blended with these. In the lubricating oil composition, in some cases, at least a portion of the various additives blended therein may be reacted to form another compound.

Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to the following examples.
[Examples and Comparative Examples]
Sample oils of lubricating oil compositions were prepared using the following base oils, dispersants, metal detergents and other additives, and the characteristics and properties of these sample oils were measured by the evaluation method described later. The results are shown in Tables 1 and 2.
Base oil: hydrogenated refined base oil, 40 ° C. kinematic viscosity 21 mm ² / s, 100 ° C. kinematic viscosity 4.5 mm ² / s, viscosity index 127,% CP 83,% CA 0.0, sulfur content less than 10 mass ppm, NOACK evaporation 13.3% by mass
Viscosity index improver A: Polymethacrylate, weight average molecular weight 420,000, resin amount 39% by mass
Phenolic antioxidant: Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate Amine antioxidant: dialkyl diphenylamine, nitrogen content 4.62% by mass
Zinc dithiophosphate: Zn content: 9.0% by mass, phosphorus content: 8.2% by mass, sulfur content: 17.1% by mass, alkyl group; mixture of secondary butyl group and secondary hexyl group metal cleaning Agent A: neutral calcium sulfonate, base number (perchloric acid method) 20 mg KOH / g, calcium content 1.8 mass%, sulfur content 1.8 mass%
Metal detergent B: neutral calcium sulfonate, base number (perchloric acid method) 22 mg KOH / g, calcium content 2.4 mass%, sulfur content 3.0 mass%
Metal detergent C: overbased calcium sulfonate, base number (perchloric acid method) 308 mg KOH / g, calcium content 12% by mass, sulfur content 1.1% by mass
Metal detergent D: Overbased calcium sulfonate, base number (perchloric acid method) 320 mg KOH / g, calcium content 13 mass%, sulfur content 2.4 mass%
Metal detergent E: overbased calcium sulfonate, base number (perchloric acid method) 450 mg KOH / g, calcium content 15% by mass, sulfur content 1.2% by mass
Metal detergent F: overbased calcium sulfonate, base number (perchloric acid method) 500 mg KOH / g, calcium content 18.5 mass%
Metallic detergent G: Overbased calcium phenate, base number (perchloric acid method) 200 mg KOH / g, calcium content 7.2 mass%, sulfur content 2.0 mass%
Metal detergent H: overbased calcium phenate, base number (perchloric acid method) 255 mg KOH / g, calcium content 9.2% by mass, sulfur content 3.3% by mass
Metal detergent I: Overbased calcium phenate, base number (perchloric acid method) 400 mg KOH / g, calcium content 14 mass%, sulfur content 2 mass%
Metal detergent J: neutral calcium salicylate, base number (perchloric acid method) 64 mg KOH / g, calcium content 2.3 mass%
Metal detergent K: overbased sodium sulfonate, base number (perchloric acid method) 450 mg KOH / g, sodium content 19.5% by mass, sulfur content 1.2% by mass
Metal detergent L: Overbased magnesium sulfonate, base number (perchloric acid method) 410 mg KOH / g, magnesium content 9.4 mass%, sulfur content 2.0 mass%
Metal detergent M: overbased calcium salicylate, base number (perchloric acid method) 230 mg KOH / g, calcium content 7.9 mass%
Metal detergent N: overbased calcium salicylate, base number (perchloric acid method) 290 mg KOH / g, calcium content 7.8 mass%
Ashless dispersant A: Boron derivative of alkenyl succinimide, number average molecular weight of polybutenyl group 1000, nitrogen content 1.8% by mass, boron content 2.0% by mass
Ashless dispersant B: alkenyl succinimide, number average molecular weight 2000 of polybutenyl group, nitrogen content 1.0% by mass
Methyl benzotriazole derivative: 1- [N, N-bis (2-ethylhexyl) aminomethyl] methyl benzotriazole Other additives: pour point depressants and antifoam agents

[Characteristic evaluation of base oil and lubricating oil composition]
(1) Dynamic viscosity of base oil and lubricating oil composition It measured based on the "petroleum product dynamic viscosity test method" prescribed | regulated to JISK2283.
(2) Viscosity index of base oil It measured based on the "petroleum product dynamic viscosity test method" prescribed | regulated to JISK2283.
(3) Sulfur content of base oil It measured based on JISK2541.
(4)% CA of base oil ... ring analysis The proportion (percentage) of the aromatic component was calculated by the n-d-M method.
(5)% CP of base oil ... ring analysis The proportion (percentage) of the paraffin component was calculated by the n-d-M method.
(6) NOACK evaporation amount of base oil It measured based on JPI-5S-41-2004.
(7) Boron content It measured based on JPI-5S-38-92.
(8) Nitrogen content It measured based on JISK2609.
(9) Molybdenum and phosphorus content It measured based on JPI-5S-38-92.
(10) Sulfated ash content Measured in accordance with JIS K2272.

[Evaluation method]
<High temperature cleanliness evaluation method (hot tube test)>
The high temperature cleanliness was evaluated by the hot tube test in accordance with JPI-5S-55-99. Specifically, the sample oil was kept flowing at a flow rate of 0.31 mL / h and air at a flow rate of 10 mL / min for 16 hours in a glass tube with an inner diameter of 2 mm. The temperature of the glass tube was kept at 280 ° C. Thereafter, the mass of the deposit deposited in the glass tube was measured. The evaluation is made on a scale of 10, and the higher the score, the smaller the mass of the deposit deposit, and the better the high-temperature cleaning property.
<Initial film formation test>
A rotating ball and a fixed ball are completely electrically insulated by a lubricating oil film in a test time of 180 seconds under the conditions of oil temperature 80 ° C., rotation speed 500 rpm, load 0.0480 MPa using the Kuwata four-ball tester. The time was evaluated as film formation time. The shorter the film formation time, the better the initial film formation ability and the better the abrasion resistance.
<Load capacity test>
Using Oda four ball tester, increase the load by 0.196 MPa every 3 minutes from initial load 0.048 MPa under the condition of oil temperature 80 ° C and rotation speed 500 rpm, apply load up to 0.288 MPa, and rotate The load at which the ball and the fixed ball were electrically completely conducted was evaluated as a complete contact load. The larger the value of the complete contact load, the better the load bearing performance.

[Evaluation results]
From the results of Table 1, it can be seen that in the examples using the lubricating oil composition of the present invention, the amount of deposited deposit in the hot tube test is small, and the high-temperature cleanliness is excellent. Moreover, since the lubricating oil composition of the example has good results in the initial film formation test, it can be seen that the oil film breakage hardly occurs even at the piston top dead center and the wear resistance is good. It is also excellent in load bearing performance.

Claims (7)

A base oil containing at least one selected from mineral oil and synthetic oil, having a viscosity index of 120 or more, and having a paraffin content by ring analysis of 70% or more;
(A) A boride of alkenyl succinimide or a boride of alkyl succinimide, and a dispersant comprising an alkenyl succinimide or an alkyl succinimide.
(B) A metallic detergent comprising one or more compounds selected from calcium sulfonate, calcium phenate, and overbased calcium salicylate,
The component (A) is contained in an amount of 0.01% by mass or more and 0.10% by mass or less in terms of nitrogen content based on the total amount of the composition
Component (B) is contained in an amount of 0.01% by mass or more and 0.3% by mass or less in terms of the metal content in terms of the total amount of the composition, and from the calcium sulfonate, calcium phenate, and overbased calcium salicylate The calcium content based on the one or more selected compounds is at least 0.09 mass% in terms of the metal content in terms of the total amount of the composition,
B: at least one compound selected from the boride of the alkenyl succinimide and the boride of the alkyl succinimide in the component (A), which is a mass ratio of boron to nitrogen contained in the component (A); / N ratio is 0.6 or more,
The phosphorus content in the total amount of the composition is 100 mass ppm or more and 1200 mass ppm or less,
A lubricating oil composition having a sulfated ash content of 1.1% by mass or less based on the total amount of the composition.   The lubricating oil composition according to claim 1, wherein the component (B) is calcium sulfonate, and the base number of the component (B) is 10 mg KOH / g to 600 mg KOH / g.   The antioxidant selected from amine-based antioxidants, phenol-based antioxidants, and molybdenum amine-based antioxidants is contained in an amount of 0.3% by mass or more and 3% by mass or less based on the total amount of the lubricating oil composition. The lubricating oil composition as described in 2.   The lubricating oil composition according to any one of claims 1 to 3, wherein the phosphorus content is 200 mass ppm or more and 1100 mass ppm or less. The lubricating oil composition according to any one of claims 1 to 4, wherein the metal detergent (B) is contained in an amount of 0.01% by mass or more and 0.09 % by mass or less in terms of metal content.   The lubricating oil composition according to any one of claims 1 to 5, which is used for lubricating an internal combustion engine.   7. The lubricating oil composition of claim 6, wherein at least the piston head is used to lubricate an internal combustion engine made of cast iron material.