JP6302458B2 - Lubricating oil composition - Google Patents

Description

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

Currently, environmental regulations on a global scale are becoming stricter, and the situation surrounding automobiles is becoming stricter, such as fuel efficiency regulations and exhaust gas regulations. This is due to environmental issues such as global warming and resource protection from concerns over the depletion of petroleum resources. For the above reasons, it is further desired to reduce the fuel consumption of automobiles.
When the output of an automobile engine is increased, the combustion temperature and pressure in the engine tend to increase. In particular, in a diesel engine, resistance and rigidity at high temperatures, heat cracking resistance, and the like are required, and therefore it is necessary to design the engine firmly. However, in order to reduce fuel consumption, it is necessary to reduce the weight of the engine.
Therefore, conventionally, an aluminum alloy such as JIS AC8A has been used for a diesel engine piston in order to reduce the weight. In addition, a lubricating oil composition suitable for lubricating diesel engines using an aluminum alloy has been developed (see, for example, Patent Document 1).

JP 2010-10070 A

However, pistons made of aluminum alloy have a thermal and mechanical endurance temperature of about 350 ° C. and a large amount of thermal expansion. Therefore, there is an improvement in response to the recent demand for higher output and lower fuel consumption of automobile engines. In place of the aluminum alloy, a cast iron piston having a thermal and mechanical endurance temperature of up to about 400 ° C. is partially employed.
The cast iron piston has higher durability than a piston made of an aluminum alloy and also has good seizure resistance because graphite contained in the cast iron has self-lubricating properties. However, cast iron pistons are more likely to cause engine performance degradation because they have higher wear and lower cleanliness due to the high temperature near the piston top dead center than aluminum alloys.
Therefore, the present invention can prevent deterioration in engine performance even when used in an internal combustion engine for automobiles that can achieve higher output and lower fuel consumption by increasing the thermal and mechanical durability temperatures than in the past. An object of the present invention is to provide a lubricating oil composition capable of satisfying both the durability and the durability.

As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by mixing these oils under specific conditions in a lubricating oil composition having a base oil and a dispersant. It came to be completed.
That is, the lubricating oil composition according to the present invention comprises a base oil containing at least one selected from mineral oil and synthetic oil, having a viscosity index of 120 or more, and a paraffin content by ring analysis of 70% or more, and (A A dispersant containing one or more compounds selected from alkenyl succinimide, alkenyl succinimide borate, alkyl succinimide, and alkyl succinimide borate, and (B) molybdenum dithiocarbamate, 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, and the boronated product and alkyl of the alkenyl succinimide in the component (A) One or more compounds selected from succinimide boride are contained in an amount of 0.05% by mass to 3.5% by mass based on the total amount of the composition. The phosphorus content on the basis of the total composition is 100 mass ppm or more and 1200 mass ppm or less, the sulfated ash content on the basis of the total composition is 1.2 mass% or less, and the molybdenum content on the basis of the total composition is 300 mass ppm or more. It is 1000 mass ppm or less.

  Further, the method for producing a lubricating oil composition according to the present invention includes a base oil containing at least one selected from mineral oil and synthetic oil, having a viscosity index of 120 or more and a paraffin content by ring analysis of 70% or more. (A) a dispersant containing at least one compound selected from alkenyl succinimides, alkenyl succinimide borides, alkyl succinimides, and alkyl succinimide borides, and (B) molybdenum dithiols Carbamate, (A) component is contained in 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, and (A) the alkenyl succinimide borate and alkyl One or more compounds selected from succinimide boride are contained in an amount of 0.05% by mass to 3.5% by mass based on the total amount of the composition. The phosphorus content on the basis of the total composition is 100 mass ppm or more and 1200 mass ppm or less, the sulfated ash content on the basis of the total composition is 1.2 mass% or less, and the molybdenum content on the basis of the total composition is 300 mass ppm or more. It is a manufacturing method of the lubricating oil composition which manufactures a lubricating oil composition by mix | blending so that it may be 1000 mass ppm or less.

  According to the present invention, it is possible to prevent deterioration in engine performance even when used in an internal combustion engine for automobiles that can achieve higher output and lower fuel consumption by increasing the thermal and mechanical durability temperatures than in the past. It is possible to provide a lubricating oil composition capable of satisfying both of the above durability.

[Lubricating oil composition]
The lubricating oil composition according to the present invention comprises a base oil containing at least one selected from mineral oil and synthetic oil, having a viscosity index of 120 or more and a paraffin content by ring analysis of 70% or more, and (A) alkenyl A dispersant containing at least one compound selected from succinimide, alkenyl succinimide borate, alkyl succinimide, and alkyl succinimide borate, and (B) molybdenum dithiocarbamate .
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, and the boronated product of the alkenyl succinimide and the alkyl succinimide in the component (A) A dispersant comprising one or more compounds selected from the above borides is contained in an amount of 0.05% by mass to 3.5% by mass based on the total amount of the composition, and a phosphorus content in the total amount of the composition of 100 ppm by mass to 1200%. The mass is ppm or less.
Moreover, the sulfated ash content on the basis of the total amount of the lubricating oil composition is 1.2% by mass or less, and the molybdenum content on the basis of the total amount of the composition is 300 ppm to 1000 ppm by mass.

[Base oil]
The base oil of the composition may be mineral oil or synthetic oil. There is no restriction | limiting in the kind of this mineral oil or synthetic oil, Arbitrary things can be suitably selected from the mineral oil and synthetic oil conventionally used as a base oil of a lubricating oil composition, and can be used.
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 refined by one or more treatments such as wax, hydrorefining, or the like, or mineral oil produced by isomerizing wax, GTL WAX, and the like.
Synthetic oils include, for example, polybutene, polyolefins [α-olefin homopolymers and copolymers (for example, ethylene-α-olefin copolymers)], various esters (for example, polyol esters, dibasic acid esters, phosphorus Acid ester, etc.), various ethers (eg, polyphenyl ether), polyglycol, alkylbenzene, alkylnaphthalene and the like. Of these synthetic oils, polyolefins and polyol esters are particularly preferred from the viewpoints of viscosity characteristics, solubility of additives, and compatibility with seal rubbers.
In the present invention, one kind of the mineral oil may be used, or two or more kinds may be used in combination. Moreover, the said synthetic oil may be used 1 type and may be used in combination of 2 or more type. Further, one or more mineral oils and one or more synthetic oils may be used in combination.
There is no restriction | limiting in particular about the viscosity of a base oil, According to the use of a lubricating oil composition, it can select. 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, 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.

The base oil has a paraffin content (may be described as% CP) by ring analysis of 70% or more. When% CP is less than 70%, the oxidation stability is poor, and an increase in acid value and sludge are likely to occur. From the above viewpoint, the% 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 viscosity change due to a change in temperature, and a fuel efficiency improvement effect at low temperatures is reduced.

[(A) component]
The component (A) is a dispersant containing one or more compounds selected from alkenyl succinimides, alkenyl succinimide borides, alkyl succinimides, and alkyl succinimide borides.
When the component (A) contains an alkenyl succinimide or an alkyl succinimide boride, the high-temperature cleanability is further enhanced.
In the present embodiment, the succinimide includes a monoimide structure and a bisimide structure.
The monoimide structure includes both a structure based on a single alkenyl or alkyl succinic acid monoimide and a structure based on a boride of alkenyl or alkyl succinic monoimide. Examples of the alkenyl or alkyl succinic acid monoimide include alkenyl or alkyl succinic acid monoimide represented by the following formula (1).
Similarly, the bisimide structure includes both a structure based on an alkenyl or alkyl succinic acid bisimide alone and a structure based on a boride of an alkenyl or alkyl succinic acid bisimide. Examples of the alkenyl or alkyl succinic acid bisimide include alkenyl or alkyl succinic acid bisimide represented by the following formula (2).

In the above formulas (1) and (2), R ¹ , R ³ and R ⁴ are alkenyl groups or alkyl groups, and the mass average molecular weights are preferably 500 or more and 3,000 or less, respectively, more preferably 1 3,000 to 3,000.
When the mass average molecular weight of R ¹ , R ³ and R ⁴ described above is 500 or more, the solubility in the base oil increases, 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 0 or an integer of 1 to 10. Here, m is preferably 2 to 5, more preferably 3 to 4. When m is 2 or more, even better high-temperature cleanability can be provided, and when m is 5 or less, the solubility in base oil is further improved.
In said formula (2), n becomes like this. Preferably it is 1-4, More preferably, it is 2-3. Unlike monoimide, when n is 1 or more, high-temperature cleanability is even better, and when n is 4 or less, solubility in base oil is even better.

  Examples of the alkenyl group include a polybutenyl group, a polyisobutenyl group, and an ethylene-propylene copolymer, and examples of the alkyl group include those obtained by hydrogenation thereof. Suitable alkenyl groups include polybutenyl or polyisobutenyl groups. The polybutenyl group is suitably obtained as a mixture of 1-butene and isobutene or a polymer of high-purity isobutene. A representative example of a suitable alkyl group is a hydrogenated polybutenyl group or polyisobutenyl group.

  The above alkenyl or alkyl succinimide is usually prepared by reacting an alkenyl succinic anhydride obtained by reaction of a polyolefin with maleic anhydride, or an alkyl succinic anhydride obtained by hydrogenating it with a polyamine. Can be manufactured by. The succinic monoimide and succinic bisimide described above can be produced by changing the reaction ratio of alkenyl succinic anhydride or alkyl succinic anhydride and polyamine.

As the olefin monomer that forms the above-mentioned polyolefin, one or more of α-olefins having 2 to 8 carbon atoms can be mixed and used, but a mixture of isobutene and 1-butene is preferably used. be able to.
On the other hand, polyamines include ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, and other single diamines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di (methylethylene) triamine, dibutylenetriamine, triethylene Examples thereof include polyalkylene polyamines such as butylenetetramine and pentapentylenehexamine, and piperazine derivatives such as aminoethylpiperazine.

Moreover, what was manufactured by the conventional method can be used for the boride of an alkenyl or alkyl succinimide.
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.

  Here, the component (A) has a mass ratio (Nm / Nb) of nitrogen derived from the monoimide structure and nitrogen derived from the bisimide structure of 0.5 or less, preferably 0.4 or less. Engine durability can be improved as mass ratio (Nm / Nb) is 0.5 or less.

In the component (A), at least one compound selected from alkenyl succinimide, alkenyl succinimide borate, alkyl succinimide, and alkyl succinimide borate has a nitrogen content based on the total amount of the composition. It is contained 0.01% by mass or more and 0.10% by mass or less in terms of conversion. The compound of component (A) is preferably contained in an amount of 0.02% by mass or more and 0.09% by mass or less, more preferably 0.03% by mass or more and 0.08% by mass in terms of the nitrogen content based on the total amount of the composition. % Or less is included. When this compound is less than 0.01% by mass in terms of nitrogen content, the high-temperature cleanability is deteriorated, and when it exceeds 0.10% by mass, the oxidation stability is deteriorated.
In the lubricating oil composition according to the present embodiment, one or more compounds selected from the borides of alkenyl succinimide and alkyl succinimides in component (A) are 0.05 mass on the basis of the total amount of the composition. % To 3.5% by mass, preferably 0.1% to 3.0% by mass, and more preferably 0.5% to 2.5% by mass. If at least one compound selected from the alkenyl succinimide borate and the alkyl succinimide borate in the component (A) is within this range, the high-temperature cleanability is further enhanced.

  In addition, when the component (A) contains either one of an alkenyl succinimide borate or an alkyl succinimide borate, it constitutes an alkenyl or alkyl succinimide borate in the component (A). The mass ratio (B / N ratio) between boron and nitrogen is preferably 0.5 or more, more preferably 0.6 or more, and still more preferably 0.8 or more. When the B / N ratio is 0.5 or more, the high-temperature cleanability is greatly improved.

  High temperature detergency is exhibited by the presence of a certain amount or more of the boron content derived from the alkenyl or alkyl succinimide borate in the component (A). If the boron content derived from the alkenyl or alkyl succinimide borate in the component (A) is 0.01% by mass or more and 0.06% by mass or less on the basis of the total amount of the composition, sufficient high-temperature cleanliness is obtained. can get. Preferably, they are 0.02 mass% or more and 0.05 mass% or less.

[Component (B)]
In this composition, molybdenum dithiocarbamate (hereinafter also referred to as MoDTC) is blended as the component (B). (B) As a component, MoDTC shown by following formula (3) is mentioned, for example.

Here, in the above formula (3), R ^{7 to} R ¹⁰ are preferably hydrocarbon groups having 4 to 22 carbon atoms, such as an alkyl group, an alkenyl group, an alkylaryl group, a cycloalkyl group, and a cycloalkenyl group. Etc. Among these, R ^{7 to} R ¹⁰ are preferably branched or straight chain alkyl groups or alkenyl groups having 4 to 18 carbon atoms, and are soluble in base oils and can be easily used. Thirteen alkyl groups are more preferred. For example, n-octyl group, 2-ethylhexyl group, isononyl group, n-decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group and the like can be mentioned. R ^{7 to} R ¹⁰ may be the same as or different from each other, but when R ⁷ and R ⁸ are different alkyl groups from R ⁹ and R ^{10, they} are dissolved in the base oil. , Storage stability and durability of friction reduction ability are improved.
In the above formula (3), X ^{1 to} X ⁴ may each be a sulfur atom or an oxygen atom, and all of X ^{1 to} X ⁴ may be a sulfur atom or an oxygen atom. Here, the ratio of sulfur atom and oxygen atom is sulfur atom / oxygen atom = 1/3 to 3/1, and more preferably 1.5 / 2.5 to 3/1, in terms of corrosion resistance, It is preferable for improving the solubility in the base oil.
As the component (B), one type may be used alone, or two or more types may be used in combination.

[Component (C)]
In the present composition, zinc dialkyldithiophosphate (hereinafter also referred to as ZnDTP) is preferably blended as component (C). (C) As a component, ZnDTP shown by following formula (4) is mentioned, for example.

In the above formula (4), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are alkyl substituted with a primary or secondary alkyl group having 3 to 22 carbon atoms or an alkyl group having 3 to 18 carbon atoms. It is a substituent selected from an aryl group, and they may be the same as or different from each other.

In the present invention, these ZnDTPs may be used singly or in combination of two or more, and in particular, those having a secondary alkyl group zinc dithiophosphate as a main component. In order to improve wear resistance, it is preferable.
Specific examples of ZnDTP include zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, zinc dipentyldithiophosphate, zinc dihexyldithiophosphate, zinc diisopentyldithiophosphate, zinc diethylhexyldithiophosphate, zinc dioctyldithiophosphate, dinonyldithiophosphate. Zinc, zinc didecyl dithiophosphate, zinc didodecyl dithiophosphate, zinc dipropylphenyl dithiophosphate, zinc dipentylphenyl dithiophosphate, zinc dipropylmethylphenyl dithiophosphate, zinc dinonylphenyl dithiophosphate, zinc didodecylphenyl dithiophosphate, di Examples include zinc dodecylphenyl dithiophosphate.

[Other ingredients]
In the lubricating oil composition according to the present invention, an antioxidant, a metallic detergent, a viscosity index improver, a pour point depressant, a rust preventive, a metal are included as long as the effects of the present invention are not impaired. An inactivating agent, an antifoaming agent, an antiwear agent, an extreme pressure agent, and other additives may be added.
<Antioxidant>
As the antioxidant, a phenol-based or amine-based antioxidant can be used.
Examples of the phenolic antioxidant include octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate; 4,4′-methylenebis (2,6-di-t-butylphenol); 4,4′-bis (2,6-di-t-butylphenol); 4,4′-bis (2-methyl-6-t-butylphenol); 2,2′-methylenebis (4-ethyl-6-t) -Butylphenol); 2,2'-methylenebis (4-methyl-6-tert-butylphenol); 4,4'-butylidenebis (3-methyl-6-tert-butylphenol); 4,4'-isopropylidenebis (2 , 6-di-t-butylphenol); 2,2′-methylenebis (4-methyl-6-nonylphenol); 2,2′-isobutylidenebis (4,6-dimethylphenol); '-Methylenebis (4-methyl-6-cyclohexylphenol); 2,6-di-t-butyl-4-methylphenol; 2,6-di-t-butyl-4-ethylphenol; 2,4-dimethyl- 6-t-butylphenol; 2,6-di-t-amyl-p-cresol; 2,6-di-t-butyl-4- (N, N′-dimethylaminomethylphenol); 4,4′-thiobis (2-methyl-6-tert-butylphenol); 4,4′-thiobis (3-methyl-6-tert-butylphenol); 2,2′-thiobis (4-methyl-6-tert-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, bisphenol-based and ester group-containing phenol-based ones are particularly preferable.

  Examples of amine-based antioxidants include monoalkyldiphenylamines such as monooctyldiphenylamine and monononyldiphenylamine; 4,4′-dibutyldiphenylamine, 4,4′-dipentyldiphenylamine, 4,4′-dihexyldiphenylamine, 4 , 4′-diheptyldiphenylamine, 4,4′-dioctyldiphenylamine, dialkyldiphenylamines such as 4,4′-dinonyldiphenylamine; polyalkyldiphenylamines such as tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, tetranonyldiphenylamine Systems; and those of the naphthylamine type, specifically α-naphthylamine, phenyl-α-naphthylamine, and even 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, the diphenylamine type is more preferable than the naphthylamine type in terms of the antioxidant effect.

In the present invention, a molybdenum amine antioxidant may be further added. As the molybdenum amine antioxidant, a hexavalent molybdenum compound, specifically, a product 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 compound obtained by the method can be used.
It does not restrict | limit especially as an amine compound made to react with a hexavalent molybdenum compound. Specific examples include monoamines, diamines, polyamines and alkanolamines. 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). Alkylamines; alkenylamines having 2 to 30 carbon atoms such as ethenylamine, propenylamine, butenylamine, octenylamine, and oleylamine (these alkenyl groups may be linear or branched); methanolamine, ethanolamine , Alkanolamines having 1 to 30 carbon atoms such as methanolethanolamine and methanolpropanolamine (these alkanol groups may be linear or branched); methylenediamine, ethylenediamine, propylene Amines and alkylenediamines having 1 to 30 carbon atoms such as butylenediamine; polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine; undecyldiethylamine, undecyldiethanolamine, dodecyldipropanolamine , Oleyldiethanolamine, oleylpropylenediamine, stearyltetraethylenepentamine and other monoamines, diamines, polyamines having a C8-20 alkyl group or alkenyl group, and heterocyclic compounds such as imidazoline; alkylene oxides of these compounds Additives; and mixtures thereof. Moreover, the sulfur containing molybdenum complex etc. of the succinimide described in Japanese Patent Publication No. 3-22438 and Unexamined-Japanese-Patent No. 2004-2866 can be illustrated.

  The blending amount of the antioxidant described above 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 mass% or more and 3 mass% or less are more preferable, 0.4 mass% or more and 2 mass% or less are still more preferable, and 0.5 mass% or more and 2 mass% or less are especially preferable. If the antioxidant is 0.3% by mass or more based on the total amount of the composition, an increase in the acid value can be suppressed, and if it is 3% by mass or less, solubility in the lubricating base oil can be secured.

<Metal-based detergent>
Metallic detergents that can be added to the lubricating oil composition according to the present invention include alkali metal sulfonates, alkali metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metals It is a metallic detergent containing one or more compounds selected from salicylates. Among these, at least one of an alkyl metal sulfonate and an alkaline earth metal sulfonate is preferable.

Examples of the alkaline earth metal sulfonate include an alkaline earth metal salt of an alkyl aromatic sulfonic acid obtained by sulfonating an alkyl aromatic compound having a molecular weight of 300 to 1,500, preferably 400 to 700. In particular, magnesium salts, calcium salts and the like can be mentioned, among which calcium salts are preferably used.
Alkaline earth metal phenates include alkylphenols, alkylphenol sulfides, alkaline earth metal salts of Mannich reaction products of alkylphenols, particularly magnesium salts, calcium salts, and the like. Of these, calcium salts are preferably used.
Examples of the alkaline earth metal salicylates include alkaline earth metal salts of alkyl salicylic acid, particularly magnesium salts and calcium salts, 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 having 6 to 18 carbon atoms, which may be linear or branched. These may also be primary alkyl groups, secondary alkyl groups or tertiary alkyl groups.

  Alkaline earth metal sulfonates, alkaline earth metal phenates and alkaline earth metal salicylates include the above-mentioned alkyl aromatic sulfonic acids, alkylphenols, alkylphenol sulfides, Mannich reactants of alkylphenols, alkylsalicylic acids, etc. from magnesium and calcium. Neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earths obtained by direct reaction with one or more selected alkaline earth metal bases such as oxides or hydroxides of alkaline earth metals Metallic salicylates are included.

  Alkaline earth metal sulfonates, alkaline earth metal phenates and alkaline earth metal salicylates include the above-mentioned alkyl aromatic sulfonic acids, alkylphenols, alkylphenol sulfides, Mannich reactants of alkylphenols, alkylsalicylic acids, etc. Further, neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earth metal salicylates obtained by substituting alkali metal salts such as potassium salts with alkaline earth metal salts are included.

  Further, 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 earth metal salicylates, 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 an 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. Also included are overbased alkaline earth metal sulfonates, overbased alkaline earth metal phenates and overbased alkaline earth metal salicylates obtained by reacting metal salicylates with alkaline earth metal carbonates or borates. It is.
The alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate can be used in combination of one or more selected from the above.

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

  The base number of the metal detergent is preferably 10 mgKOH / g or more and 600 mgKOH / g or less, more preferably 20 mgKOH / g or more and 500 mgKOH / g or less. The total base number referred to here is 7. JIS K 2501 “Petroleum products and lubricants—neutralization number test method”. Means the total base number by potentiometric titration method (base number / perchloric acid method) measured according to the above.

  Moreover, there is no restriction | limiting in particular in the metal ratio contained in a metal type detergent, Usually, 20 or less things can be used in mixture of 1 type, or 2 or more types, However, Preferably, metal ratio is 3 or less, More preferably, 1. It is particularly preferable to use a metal 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, high-temperature cleanability, and the like. The metal ratio here is represented by the valence of the metal element in the metal-based detergent × metal element content (mol%) / soap group content (mol%), and the metal elements include calcium, magnesium, and the like. The soap group means a sulfonic acid group, a phenol group, a salicylic acid group, and the like.

<Viscosity index improver>
As the viscosity index improver, for example, polymethacrylate, dispersed polymethacrylate, olefin copolymer (for example, ethylene-propylene copolymer), dispersed olefin copolymer, styrene copolymer (for example, Styrene-diene copolymer, styrene-isoprene copolymer, etc.). The blending 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 blending effect.

<Pour point depressant>
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, and the like. Polymethacrylate having a molecular weight of 5,000 or more and 50,000 or less is preferably used. These are used in a proportion of 0.1% by mass or more and 5% by mass or less based on the total amount of the composition.
<Rust preventive>
Examples of the rust preventive include petroleum sulfonate, alkylbenzene sulfonate, dinonyl naphthalene sulfonate, alkenyl succinate, polyhydric alcohol ester and the like. The blending amount of these rust preventives 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 blending effect. .

<Metal deactivator>
Examples of the metal deactivator (copper corrosion inhibitor) include benzotriazole, tolyltriazole, thiadiazole, imidazole, and pyrimidine compounds. Of these, benzotriazole compounds are preferred. By compounding a metal deactivator, metal corrosion and oxidative 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 and 0% by mass based on the total amount of the composition from the viewpoint of blending effect. 0.05% by mass or less.

<Antifoaming agent>
Examples of the antifoaming agent include silicone oil, fluorosilicone oil, fluoroalkyl ether, and the like, and 0.005% by mass or more and 0.1% by mass based on the total amount of the composition from the viewpoint of balance between defoaming effect and economy. % Or less is preferable.

<Antiwear agent or extreme pressure agent>
Antiwear or extreme pressure agents include zinc dithiophosphate, zinc phosphate, zinc dithiocarbamate, molybdenum dithiocarbamate, molybdenum dithiophosphate, disulfides, sulfurized olefins, sulfurized fats and oils, sulfurized esters, thiocarbonates, thiocarbonates Sulfur-containing compounds such as carbamates and polysulfides; Phosphorous esters, phosphate esters, phosphonate esters, and phosphorus-containing compounds such as amine salts or metal salts thereof; thiophosphite esters, thiophosphoric acid Examples include sulfur and phosphorus-containing antiwear agents such as esters, thiophosphonic acid esters, and amine salts or metal salts thereof.
When other antiwear agent or extreme pressure agent is blended as necessary, the blending amount of other antiwear agent or extreme pressure agent 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, they are 0 mass ppm or more and 500 mass ppm or less, More preferably, they are 0 mass ppm or more and 400 mass ppm or less.
Moreover, the compounding quantity of another antiwear agent or extreme pressure agent is 500 mass ppm or less in terms of element as phosphorus on the basis of the total amount of the lubricating oil composition. Preferably, they are 0 mass ppm or more and 400 mass ppm or less, More preferably, they are 0 mass ppm or more and 300 mass ppm or less. When the blending amount of zinc is 600 mass ppm or less and the blending amount of phosphorus is 500 mass ppm or less, the basic compound in the lubricating oil composition, for example, engine oil is consumed, and the oil renewal period becomes extremely short. There is no.

<Phosphorus content, sulfated ash content, and molybdenum content of the lubricating oil composition>
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 amount of phosphorus is less than 100 mass ppm, the wear resistance becomes insufficient, and the friction reducing effect by the MoDTC of the component (B) cannot be sufficiently obtained. On the other hand, if the phosphorus content exceeds 1200 ppm by mass, poisoning of exhaust gas to the purification catalyst cannot be sufficiently suppressed.
The phosphorus content is preferably 200 ppm to 1100 ppm, more preferably 300 ppm to 1000 ppm, and particularly preferably 400 ppm to 900 ppm.
In the lubricating oil composition according to the present invention, the sulfated ash content based on the total amount of the composition is 1.2% by mass or less. If the sulfated ash content exceeds 1.2% by mass, the amount of ash deposited on the DPF filter in the diesel engine increases, the ash content of the DPF filter is likely to clog, and the life of the DPF filter is shortened.
From the viewpoint of further improving the oxidation stability, base number maintenance, and high-temperature cleanability of the lubricating oil composition, the sulfated ash content is more preferably 0.2% by mass or more, and particularly 0.3% by mass or more. Thus, a composition capable of maintaining the base number and the high temperature cleanliness for a longer period can be obtained.
The sulfated ash refers to the ash that has been made constant by adding sulfuric acid to the carbonized residue produced by burning the sample and heating it. Usually, to know the approximate amount of the metal additive in the lubricating oil composition. Used for. Specifically, JIS K 2272 [5. It is measured by the method specified in the sulfate ash test method].
In the lubricating oil composition according to the present invention, the molybdenum content on the basis of the total amount of the composition is 300 ppm to 1000 ppm, preferably 400 ppm to 700 ppm. If it is less than 300 ppm by mass, a sufficient friction reducing effect cannot be obtained, and if it exceeds 1000 ppm by mass, the solubility in the base oil is deteriorated and the corrosion of the metal material is likely to proceed.

  The lubricating oil composition according to the present invention is not only excellent in high-temperature cleanliness, but also has good compatibility with fluororubber seals frequently used in the engine, so that it is a gasoline engine, diesel engine, gas engine, and hybrid vehicle engine. It can use suitably for internal combustion engines, such as. Examples of the internal combustion engine include a general internal combustion engine manufactured using a material such as an aluminum alloy material, a nickel chromium alloy material, a carbon steel material, or a chromium molybdenum steel material. The lubricating oil composition according to the present invention includes: In particular, it can be suitably used for lubricating an internal combustion engine in which at least the piston head is made of cast iron material.

[Method for producing lubricating oil composition]
The method for producing a lubricating oil composition according to the present embodiment includes a base oil containing at least one selected from mineral oil and synthetic oil, having a viscosity index of 120 or more and a paraffin content by ring analysis of 70% or more. (A) a dispersant containing at least one compound selected from alkenyl succinimide, alkenyl succinimide borate, alkyl succinimide, and alkyl succinimide borate, and (B) molybdenum dithiocarbamate And (A) component 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, and the alkenyl succinimide boride and alkyl One or more compounds selected from borides of acid imides are contained in an amount of 0.05% by mass to 3.5% by mass based on the total amount of the 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, the sulfated ash content on the basis of the total amount of the composition is 1.2 mass% or less, and the molybdenum content on the basis of the total amount of the composition is 300 mass ppm or more. It is a manufacturing method of the lubricating oil composition which manufactures a lubricating oil composition by mix | blending so that it may be 1000 mass ppm or less.

  In addition, the manufacturing method of the lubricating oil composition according to the present embodiment further includes an antioxidant, a viscosity index improver, a pour point depressant, a rust inhibitor, a metal Activators, antifoaming agents, antiwear agents, extreme pressure agents, and other additives are blended.

  In addition, as mentioned above, (A) component and (B) component are added to the base oil, and further, an antioxidant, a viscosity index improver, a pour point depressant, a rust inhibitor, and a metal inert as necessary. The lubricating oil composition obtained by blending the agent, the antifoaming agent, the antiwear agent, the extreme pressure agent, and further other additives contains these various blended additives. In some cases, the lubricating oil composition may be converted into another compound by reacting at least a part of these various additives.

Hereinafter, the present invention will be described in more detail with reference to 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-based detergents, and other additives, and the characteristics and properties of these sample oils were measured by the evaluation methods described below. The results are shown in Table 1.
Base oil: hydrorefined 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 of 13.3 mass%
Viscosity index improver A: polymethacrylate, weight average molecular weight 420,000, resin amount 39% by mass
Phenol-based antioxidant: octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate Amine-based antioxidant: dialkyldiphenylamine, nitrogen content 4.62% by mass
Molybdenum / amine complex: SakuraLube S-710 (manufactured by Adeka) Molybdenum content 10% by mass, nitrogen content 1.3% 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 Agent A: Overbased calcium phenate, base number (perchloric acid method) 255 mgKOH / g, calcium content 9.3 mass%, sulfur content 3.0 mass%
Metal detergent B: Overbased calcium salicylate, base number (perchloric acid method) 225 mgKOH / g, calcium content 7.8% by mass
Metal detergent C: calcium sulfonate, base number (perchloric acid method) 17 mg KOH / g, calcium content 2.4 mass%, sulfur content 2.8 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, polybutenyl group number average molecular weight 2000, nitrogen content 1.0 mass%
Molybdenum dithiocarbamate: SakuraLube 515 (manufactured by Adeka) Mo content 10 mass%, sulfur content mass 11.5%
Methylbenzotriazole derivative: 1- [N, N-bis (2-ethylhexyl) aminomethyl] methylbenzotriazole Other additives: pour point depressant and antifoaming agent

[Characteristic evaluation of base oil and lubricating oil composition]
(1) Kinematic viscosity of base oil and lubricating oil composition Measured in accordance with “Petroleum product kinematic viscosity test method” defined in JIS K 2283.
(2) Viscosity index of base oil Measured according to “Petroleum product kinematic viscosity test method” defined in JIS K 2283.
(3) Sulfur content of base oil Measured according to JIS K2541.
(4)% CA of base oil: The ratio (percentage) of the aromatic component was calculated by the ring analysis ndM method.
(5)% CP of base oil: The ratio (percentage) of the paraffin component was calculated by the ring analysis ndM 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 Measured according to JIS K2609.
(9) Calcium, phosphorus, zinc, molybdenum, boron and phosphorus content Measured according to JPI-5S-38-92.
(10) Sulfated ash content Measured according to JIS K2272.

[Evaluation method]
<High temperature cleanliness evaluation method (hot tube test)>
High temperature cleanliness was evaluated by a hot tube test in accordance with JPI-5S-55-99. Specifically, the sample oil was continuously supplied into a glass tube having an inner diameter of 2 mm at a flow rate of 0.31 mL / h and air at a flow rate of 10 mL / min for 16 hours. The temperature of the glass tube was kept at 280 ° C. Thereafter, the mass of the deposit adhered to the glass tube was measured. The lower the mass of deposit deposit, the better the high temperature cleanability.
<Initial film formation test>
Using a Kamata four-ball tester, a rotating ball and a fixed ball are electrically insulated completely by a lubricating oil film in a test time of 180 seconds under conditions of an oil temperature of 80 ° C., a rotation speed of 500 rpm, and a load of 0.0480 MPa. Time was evaluated as the film formation time. The shorter the film formation time, the better the initial film formation ability and the better the wear resistance.
<Load bearing performance test>
Using an Iwata four-ball tester, under an oil temperature of 80 ° C. and a rotational speed of 500 rpm, the load was increased by 0.196 MPa every 3 minutes from the initial load of 0.048 MPa, and the load was applied to 0.288 MPa to rotate. The load at which the sphere and the fixed sphere are electrically conducted completely was evaluated as a complete contact load. The larger the value of the complete contact load, the better the load bearing performance.
< Friction reduction evaluation test (SRV test)>
Using a SRV tester (manufactured by Optimol), the friction coefficient of the sample oil was measured under the following conditions. The lower the friction coefficient, the better the friction reducing effect.
Test piece: (a) Disc: SUJ-2 material, (b) Cylinder: SUJ-2 material Amplitude: 1.5 mm
Frequency: 50Hz
Load: 400N
Temperature: 100 ° C

[Evaluation results]
From the results shown in Table 1, in the examples using the lubricating oil composition of the present invention containing a specific amount of molybdenum dithiocarbamate, the result in the initial film formation test is good, so that the oil film breaks even at the top dead center of the piston. It can be seen that the wear resistance is good. Moreover, it is excellent also in load bearing performance.

Claims (9)

A base oil containing at least one selected from mineral oil and synthetic 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, alkenyl succinimide borides, alkyl succinimides, and alkyl succinimide borides;
(B) molybdenum dithiocarbamate,
The component (A) is contained in an amount of 0.01% by mass or more and 0.08 % by mass or less in terms of nitrogen content based on the total amount of the composition.
In the component (A), one or more compounds selected from the alkenyl succinimide borate and the alkyl succinimide borate are contained in an amount of 0.05% by mass to 3.5% by mass based on the total amount of the 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,
The sulfated ash content based on the total amount of the composition is 1.2% by mass or less,
A lubricating oil composition having a molybdenum content of 400 to 1000 ppm by mass based on the total amount of the composition. The lubricating oil composition according to claim 1, wherein the molybdenum content based on the total amount of the composition is 700 mass ppm or more and 1000 mass ppm or less. The lubrication according to claim 1 or 2 , wherein when a boride is contained in the component (A), the B / N ratio, which is a mass ratio of boron and nitrogen contained in the component (A), is 0.5 or more. Oil composition. Amine antioxidants, phenolic antioxidants, and according to any one of claims 1 to antioxidant selected from molybdenum amine antioxidant is contained 3 wt% 0.3 wt% in the lubricating oil composition the total amount 4. The lubricating oil composition according to any one of 3 . A total amount of a metal detergent containing at least one compound selected from alkali metal sulfonates, alkali metal phenates, alkali metal salicylates, alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates. The lubricating oil composition according to any one of claims 1 to 4, comprising 0.11% by mass or more and 0.25% by mass or less in terms of metal on a standard basis. The lubricating oil composition according to any one of claims 1 to 5, wherein the phosphorus content is not more than 200 mass ppm to 1,100 mass ppm. The lubricating oil composition according to any one of claims 3 to 6 , wherein the B / N ratio is 0.6 or more. The lubricating oil composition according to any one of claims 1 to 7 used to lubricate the internal combustion engine. The lubricating oil composition according to claim 8 , wherein at least the piston head is used for lubricating an internal combustion engine made of a cast iron material.