JP2000087070A - 4-cycle engine oil composition for two wheeler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a 4-cycle engine oil compsn. for two wheelers which is excellent in reduction effect of oil consumption and in saving fuel consumption. SOLUTION: This compsn. is prepd. by using, as the base oil, a hydrocarbon lube base oil having a kinematic viscosity at 100 deg.C of 3-10 mm2/s and a viscosity index of 120 or higher or by using a mixed base oil contg. at least 15 mass % above lube base oil and further contains (A) a zinc dialkyldithiophosphate, (B) a metal-based detergent, (C) an ashless dispersant, (D) a friction modifier, and (E) a viscosity index improver for modifying the kinematic viscosity of the compsn. at 100 deg.C to 9.3-16.5 mm2/s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-cycle engine oil composition for motorcycles, and more particularly to a four-cycle engine oil composition for motorcycles that is excellent in reducing oil consumption of two-cycle four-stroke engines and excellent in fuel efficiency.

[0002]

2. Description of the Related Art A two-wheeled vehicle is characterized in that even with the same four-stroke engine, the engine speed is higher and the combustion temperature is higher than that of a four-wheeled vehicle. For this reason, when the existing four-cycle engine oil for a four-wheeled vehicle is used for a four-cycle engine for a two-wheeled vehicle, the oil consumption is high, and the oil component in the exhaust gas discharged into the atmosphere may be increased.
As a countermeasure, improvement of engine oil has been strongly demanded.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a four-stroke cycle engine oil composition for motorcycles having low oil consumption and excellent fuel efficiency. .

[0004]

In order to achieve the above object, a four-cycle engine oil composition for a motorcycle according to the present invention is provided.
As the base oil, a hydrocarbon-based lubricating base oil having a kinematic viscosity at 100 ° C. of 3 to 10 mm ² / s and a viscosity index of 120 or more, or a mixed base oil containing the base oil in an amount of 15% by mass or more based on the total amount of the base oil is used. And (A) zinc dialkyldithiophosphate (B) metal-based detergent, (C) ashless dispersant, (D) friction modifier (E) the composition has a kinematic viscosity at 100 ° C of 9.3 to 1
It contains a viscosity index improver of 6.5 mm ² / s.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in more detail. The base oil in the four-stroke engine oil composition for a motorcycle according to the present invention has a kinematic viscosity at 100 ° C of 3 to 10 mm ^2.
/ S and a hydrocarbon-based lubricating base oil having a viscosity index of 120 or more, or a mixed base oil containing the base oil in an amount of 15% by mass or more based on the total amount of the base oil. Examples of the hydrocarbon-based lubricating base oil include, for example, hydrorefining, solvent refining, dewaxing, and clay refining to a lubricating oil fraction obtained by distilling a paraffinic crude oil or a naphthenic crude oil under normal pressure and reduced pressure. Or one or more purification treatments such as chemical (acid / alkali) purification (when performing two or more purification treatments, each purification treatment can be combined in any order, and the same Mineral oils such as paraffinic mineral oils, naphthenic mineral oils and normal paraffins, and poly-α-olefins (polybutene, 1-octene oligomer, 1). -Decene oligomers), isoparaffins, alkylbenzenes, alkylnaphthalenes, and other synthetic oil-based lubricating base oils.

[0006] Among these hydrocarbon base oils, in the present invention, 1 is selected from the group consisting of the following (a) and (b) from the viewpoint of excellent oil consumption and fuel economy.
It is preferable to use a base oil obtained by mixing seeds or two or more kinds at an arbitrary ratio. (A) mineral oil having a total aromatic content of 15% by mass or less, (b)
The upper limit of the total aromatic content of the olefin polymer having 2 to 16 carbon atoms or its hydride and the component (a) is 15% by mass, preferably 10% by mass, and more preferably 7% by mass. When the total aromatic content exceeds the upper limit, the oxidation stability of the engine oil composition may be deteriorated. (A)
The lower limit of the total aromatic content of the component is not particularly limited,
When the total aromatic content is 0% by mass or more than 0% by mass and less than 2% by mass, since the sludge generated during use is hardly soluble in the engine oil composition, the total aromatic content is 2% by mass. It is preferable that this is the case. In addition, the total aromatic content referred to here is a value defined by Stann specified in ASTM D2549.
dard Test Method for Separation of Representative
Aromatics and Nonaromatics Fractions of High-Boili
ng Oils by Elution Chromatography means the aromatics fraction content measured according to
Typically, the aromatics fraction contains alkylbenzene, alkylnaphthalene, anthracene,
Examples include phenanthrene, alkylated products thereof, compounds in which four or more benzene rings are condensed, and compounds having a heteroaromatic such as pyridines, quinolines, phenols, and naphthols. The above component (a) can be produced by any known method. For example: distillate of atmospheric pressure distillation of paraffinic and / or mixed base crude oil, and vacuum distillation distillate (WVGO) of atmospheric distillation residue of paraffinic and / or mixed base crude oil ,: And / or a mild hydrocracking treated oil,:: a mixed oil of two or more oils selected from::, or deoiled oil (DAO),: a mild hydrocracking treated oil,:: A mixed oil of two or more kinds of oils selected from the group consisting of a raw material oil and a raw oil refined as it is to recover a lubricating oil fraction, or a lubricating oil fraction recovered from the raw material oil The lubricating oil fraction can be refined and, if necessary, further produced by recovering the lubricating oil fraction from the refined product. Any means can be used for refining the feedstock or lubricating oil fractions described above, for example, (1) hydrocracking, hydrorefining such as hydrofinishing,
(2) Solvent purification such as furfural solvent extraction, (3) Dewaxing treatment such as solvent dewaxing and contact dewaxing, (4) Purification of clay with acid clay or activated clay, (5) Sulfuric acid cleaning, caustic soda cleaning, etc. Chemical (acid / alkali) purification or the like can be employed alone or in combination. When two or more purification means are used in combination, the individual purification means can be combined in an arbitrary order, and the same kind of purification means can be repeated twice or more. As the component (a),
In particular, from the viewpoint of excellent oil consumption and fuel economy, a raw oil selected from the above or a lubricating oil fraction thereof is subjected to hydrocracking treatment, and a lubricating oil fraction recovered from the product or from the product is subjected to hydrocracking treatment. It is preferable to use mineral oil obtained by subjecting to a dewaxing treatment and a solvent refining treatment. The above-mentioned hydrocracking can be carried out under any conditions in the presence of a hydrocracking catalyst.
g / cm ² , temperature 350-500 ° C., LHS 0.1-2.
Under the reaction conditions of ⁰ hr ^-1, the above feedstock oil or its lubricating oil fraction is hydrocracked so that the cracking rate becomes 40% by mass or more. As an active component of the hydrocracking catalyst, for example, molybdenum, chromium, tungsten, vanadium, platinum,
One or more selected from the group consisting of metals such as nickel, copper, iron, and cobalt, and oxides and sulfides thereof can be used. These active components may be silica-alumina, It can be supported on a carrier such as alumina or zeolite. In addition, when performing the dewaxing treatment and the solvent refining treatment to the hydrocracking product or the lubricating oil fraction thereof, the order of these two treatments and the number of treatments can be arbitrarily selected. The dewaxing treatment mentioned here includes both solvent dewaxing and contact dewaxing.

On the other hand, an olefin polymer or its hydride is used as the component (b). Here, the olefin polymer has 2 to 16 carbon atoms, preferably 2 to 12 carbon atoms.
Means a homopolymer of the olefin and a copolymer of the above-mentioned olefins, and the copolymer is a random copolymer,
Either an alternating copolymer or a block copolymer may be used. The olefin monomer forming the olefin polymer may be an α-olefin or an internal olefin, and may be a linear olefin or a branched olefin. Specific examples of olefins that can be used in producing the olefin polymer of the present invention include ethylene, propylene, 1-butene, 2-butene, isobutene, pentene, hexene,
Heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene (all may be linear or branched, and may be α-olefins or internal olefins) and mixtures thereof. Among them, ethylene, propylene, 1-butene, 2-butene, isobutene, 1-octene, 1-decene, 1-dodecene and a mixture thereof are preferably used. This olefin polymer can be produced by any method. For example, it can be produced by a thermal reaction without a catalyst,
Organic peroxide catalysts such as benzoyl peroxide; Friedel-Crafts catalysts such as aluminum chloride, aluminum chloride-polyhydric alcohol, aluminum chloride-titanium tetrachloride, aluminum chloride-alkyltin halide, boron fluoride; Aluminum chloride-titanium tetrachloride,
Ziegler catalysts such as organoaluminum-titanium tetrachloride; metallocene catalysts such as aluminoxane-zirconocene and ionic compound-zirconocene; Lewis acid complex catalysts such as aluminum chloride-base and boron fluoride-base Using the known catalyst system of
It can be produced by homopolymerizing or copolymerizing the above olefin. As the component (b), the above-mentioned olefin polymer can be used. However, since the polymer usually has a double bond, when the thermal and oxidative stability is considered, the olefin polymer in the polymer may be used. It is preferable to use a hydride of an olefin polymer having a hydrogenated bond as the component (b). In order to obtain a hydride of the olefin polymer, an appropriate method can be adopted.For example, the olefin polymer is hydrogenated with hydrogen in the presence of a known hydrogenation catalyst, and a double hydrogen present in the olefin polymer is obtained. It can be obtained by saturating the bond. In addition, by selecting the catalyst to be used, there are two types of polymerization, olefin polymerization and polymer hydrogenation.
It is also possible to complete the polymerization of the olefin and the hydrogenation of the double bond present in the polymer in one step without going through the steps. Among the usable olefin polymers or hydrides thereof, ethylene-propylene copolymers, polybutene (butane-butene by-produced during naphtha pyrolysis (a mixture of 1-butene, 2-butene and isobutene) Copolymer obtained by the polymerization of a fraction), 1-octene oligomer, 1-decene oligomer, 1-dodecene oligomer, a hydride thereof, and a mixture thereof. Preferred as the component (b) in terms of excellent properties and low-temperature fluidity, particularly, hydrogenated ethylene-propylene copolymer, polybutene hydride, 1-octene oligomer hydride, 1-decene oligomer hydride, 1-d Decene oligomer hydrides and mixtures thereof are more preferred. Incidentally, synthetic hydrocarbon base oils such as ethylene-propylene copolymers, polybutenes and poly-α-olefins currently commercially available as lubricating base oils usually have double bonds already hydrogenated. These commercial products can also be used as the component (b).

100 ° C. of the hydrocarbon-based lubricating base oil of the present invention
Is 3 mm ² / s, preferably 4.0 mm ² / s, while the upper limit is 10 mm ² / s.
s, preferably 6.0 mm ² / s. When the kinematic viscosity at 100 ° C. is less than 3 mm ² / s, oil consumption is poor. On the other hand, when it exceeds 10 mm ² / s, viscosity characteristics at low temperature and fuel economy are inferior, and therefore, each is not preferable.
The viscosity index is 120 or more, preferably 125 or more. When the viscosity index of the hydrocarbon-based lubricating base oil is less than 120, oil consumption is poor, which is not preferable.

As the base oil in the four-stroke engine oil composition for a motorcycle according to the present invention, a hydrocarbon-based lubricating base oil having the above properties may be used alone, or the base oil may be used in an amount of 15% by mass based on the total amount of the base oil. %, Preferably 20% by mass or more. When used as a mixed base oil, various types of lubricating base oils can be mixed with the hydrocarbon-based lubricating base oil. These lubricating base oils are not particularly limited, and can be used irrespective of mineral oils and synthetic oils as long as they are usually used as base oils for lubricating oils. As the mineral oil-based lubricating base oil, specifically, for example, a lubricating oil fraction obtained by distilling crude oil under normal pressure and reduced pressure, solvent removal, solvent extraction, hydrocracking, solvent dewaxing, contact Oils such as paraffinic and naphthenic oils and normal paraffins, which are appropriately combined with purification treatments such as dewaxing, hydrorefining, sulfuric acid washing, and clay treatment, can be used. Specific examples of the synthetic lubricating base oil include poly-α-olefins (polybutene, 1-octene oligomer, 1-decene oligomer, etc.), isoparaffin, alkylbenzene, alkylnaphthalene, dibasic acid ester (ditridecyl) Glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc., tribasic acid ester (trimellitic acid ester, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropaneperalgo) Nate,
Pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether and the like can be used. These mineral base oils and synthetic base oils may be used alone, or two or more base oils selected from them may be used in combination at an arbitrary mixing ratio. The viscosity of these lubricating base oils is arbitrary, but lubricity and cooling (heat removal)
Kinematic viscosity at 40 ° C. is preferably 5 to 15
0 mm ² / s, more preferably not to use those of 10~110mm ² / s.

[0010] The component (A) in the four-stroke engine oil composition for a motorcycle according to the present invention is a zinc dialkyldithiophosphate. Specific examples of the zinc dialkyldithiophosphate include compounds represented by the following general formula (1).

Embedded image In the formula, R ¹ , R ² , R ³ and R ⁴ may be the same or different, and represent a linear or branched alkyl group having 2 to 18 carbon atoms, preferably 3 to 8 carbon atoms. Ethyl group, propyl group, butyl group, pentyl group, hexyl group,
Heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group,
Examples thereof include a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group and the like, and these may be linear or branched. These may also be primary, secondary or tertiary alkyl groups. When introducing R ¹ , R ² , R ³ and R ⁴ , a mixture of α-olefins may be used as a raw material. In this case, as the component (A), zinc dialkyldithiophosphate having an alkyl group having a different structure is used as the component (A). And a mixture of More preferred zinc dialkyl dithiophosphates, specifically, zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl dithiophosphate, zinc dihexyl dithiophosphate, zinc diheptyl dithiophosphate,
Examples thereof include zinc dioctyl dithiophosphate (the alkyl groups may be linear or branched) and mixtures thereof, but different numbers of carbon atoms in one molecule (3 to 3 carbon atoms).
8) Zinc dialkyldithiophosphates having an alkyl group of and / or structure can also be preferably used.
The content of the component (A) in the four-stroke engine oil composition for motorcycles of the present invention is arbitrary, but is usually 0.5 to 2.0% by mass, preferably 0.5 to 2.0% by mass, based on the total amount of the composition. ~
It is 1.5% by mass, more preferably 0.6 to 1.2% by mass. When the content of the component (A) is less than 0.5% by mass, the friction coefficient becomes high after deterioration of the engine oil, so that low fuel efficiency cannot be maintained. , The exhaust gas may be adversely affected.

The component (B) in the four-cycle engine oil composition for a motorcycle according to the present invention is a metal-based detergent. As the metal-based detergent, any compound used as a metal-based detergent for lubricating oils can be used. Specifically, for example, alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates And one or more metal-based detergents selected from the above. Alkaline earth metal sulfonates have a molecular weight of 1
Alkaline earth metal salts of alkylaromatic sulfonic acids obtained by sulfonating from 300 to 1500, preferably from 400 to 700, alkylaromatic compounds;
Particularly magnesium salts and / or calcium salts,
Calcium salts are preferably used. Specific examples of the alkyl aromatic sulfonic acid include so-called petroleum sulfonic acid and synthetic sulfonic acid. As the petroleum sulfonic acid used herein, a sulfonated alkyl aromatic compound of a lubricating oil fraction of a mineral oil, a so-called mahoganic acid which is a by-product of white oil production, and the like are generally used. Examples of the synthetic sulfonic acid include sulfonation of alkylbenzene having a linear or branched alkyl group, which is obtained as a by-product from an alkylbenzene production plant used as a raw material of a detergent or obtained by alkylating a polyolefin to benzene. Or a sulfonated alkylnaphthalene such as dinonylnaphthalene. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but fuming sulfuric acid or sulfuric anhydride is usually used. Examples of the alkaline earth metal phenate include an alkaline earth metal salt of an alkylphenol, an alkylphenol sulfide, and a Mannich reaction product of an alkylphenol, particularly, a magnesium salt and / or a calcium salt. For example, in the following general formulas (2) to (4), What is represented can be mentioned.

Embedded image

Embedded image

Embedded image In the formula, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different, and each represents a linear or branched alkyl group having 4 to 30, preferably 6 to 18 carbon atoms. , M ¹ ,
M ² and M ³ each represent an alkaline earth metal, preferably calcium and / or magnesium, and x represents an integer of 1 to 2. In the above formula, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰
As specifically, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group,
Undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, henycosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group Octacosyl group, nonacosyl group, triacontyl group and the like, which may be linear or branched. They may also be primary, secondary or tertiary alkyl groups. Examples of the alkaline earth metal salicylate include alkaline earth metal salts of arylsilicylic acid, particularly magnesium salts and / or calcium salts, and examples thereof include those represented by the following general formula (5).

Embedded image In the formula, R ¹¹ represents a linear alkyl group having 4 to 30, preferably 6 to 18 carbon atoms, and M ⁴ represents an alkaline earth metal, preferably calcium and / or magnesium. R ¹¹
As specifically, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group,
Undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, henycosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group Octacosyl group, nonacosyl group, triacontyl group and the like, which may be linear or branched. They may also be primary, secondary or tertiary alkyl groups. Further, as the alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate, the above-mentioned alkyl aromatic sulfonic acid, alkyl phenol, alkyl phenol sulfide, Mannich reaction product of alkyl phenol, alilic salicylic acid, etc. And / or react with alkaline earth metal bases such as alkaline earth metal oxides and hydroxides of calcium, or replace alkali metal salts such as sodium salts and potassium salts once with alkaline earth metal salts. (Neutral salt) alkaline earth metal sulfonate, neutral (normal salt) alkaline earth metal phenate and neutral (normal salt) alkaline earth metal salicylate, as well as neutral alkaline earth metal sulfonate , Neutral alkali Basic alkaline earth metal sulfonates and basic alkaline earths obtained by heating a metal-like phenate and a neutral alkaline earth metal salicylate and an excess of an alkaline earth metal salt or an alkaline earth metal base in the presence of water Reaction of metal phenate and basic alkaline earth metal salicylate and neutral alkaline earth metal sulfonate, neutral alkaline earth metal phenate and neutral alkaline earth metal salicylate in the presence of carbon dioxide gas with alkaline earth metal base Also included are overbased (ultrabasic) alkaline earth metal sulfonates, overbased (ultrabasic) alkaline earth metal phenates and overbased (ultrabasic) alkaline earth metal salicylates. As the detergent in the present invention, the above-mentioned neutral alkaline earth metal salts, basic alkaline earth metal salts, overbased (ultrabasic) alkaline earth metal salts, and mixtures thereof can be used. . The metal-based detergent is usually commercially available in a diluted state with a light lubricating base oil or the like, and is available, but generally has a metal content of 1.0 to 20% by mass, preferably Is 2.0-1
It is desirable to use 6% by mass. Although the total base number of the metal-based detergent used in the present invention is arbitrary, the total base number is usually 30 to 30 from the viewpoint of excellent antioxidant properties and fuel economy.
400 mg KOH / g, preferably 150-300 mg
It is desirable to use KOH / g. In addition, the total base number mentioned here is JIS K2501 (1992) "7. Means the total base number measured by the perchloric acid method in accordance with
The content of the component (B) in the motorcycle four-stroke engine oil composition of the present invention is arbitrary, but is usually 1.0 to 10.0% by mass, preferably 1.0 to 10.0% by mass, based on the total amount of the composition.
It is 8.0% by mass, and more preferably 1.5 to 5.0% by mass. When the content of the component (B) is less than 1.0% by mass, the friction coefficient becomes high after deterioration of the engine oil, so that low fuel efficiency cannot be maintained. When the content exceeds 10.0% by mass, However, the fuel consumption reduction effect may be poor.

The component (C) in the four-stroke engine oil composition for a motorcycle according to the present invention is an ashless dispersant. The ashless dispersant generally has a polybutenyl group having a number average molecular weight of 900 to 3,500, preferably 1,000 to 2,000, and specific examples thereof include polybutenyl succinimide, polybutenyl benzylamine, and polybutenyl succinate. An acid ester or a mixture thereof is exemplified. Examples of the polybutenyl succinimide include a monoimide represented by the following general formula (6) or a bisimide represented by the following general formula (7).

Embedded image

Embedded image In the general formulas (6) and (7), R ¹² , R ¹³ and R ¹⁴ each represent a polybutenyl group having a number average molecular weight of 900 to 3,500, preferably 1,000 to 2,000, and a
And b each represent an integer of 1 to 5. Examples of polybutenylbenzylamine include those represented by the following general formula (8).

Embedded image In the general formula (8), R ¹⁵ and R ¹⁶ each represent a number average molecular weight of 900 to 3500, preferably 1000 to 200.
0 represents a polybutenyl group, and c represents an integer of 1 to 5.
Examples of the polybutenyl succinate include those represented by the following general formula (9).

Embedded image In the general formula (9), R ¹⁷ is a number average molecular weight of 900 to 3
500, preferably 1000 to 2000 polybutenyl groups. Further, as the component (C) of the present invention, the above-mentioned nitrogen-containing compounds such as polybutenylsuccinimide, polybutenylbenzylamine, and polybutenylsuccinate can be used in combination with monocarboxylic acids having 2 to 30 carbon atoms (fatty acids). Etc.) and oxalic acid, phthalic acid, trimellitic acid, pyromellitic acid, etc. to react a polycarboxylic acid having 2 to 30 carbon atoms to neutralize a part or all of the remaining amino group and / or imino group. Or amidated, so-called acid-denatured compound; boric acid acting on the nitrogen-containing compound as described above to neutralize or amidate a part or all of the remaining amino group and / or imino group; A so-called boron-modified compound; a sulfur-modified compound obtained by allowing a sulfur compound to act on the nitrogen-containing compound as described above;
Modified compounds obtained by combining two or more kinds of modifications selected from boron modification and sulfur modification; and mixtures thereof can also be preferably used. The content of the component (C) in the motorcycle four-stroke engine oil composition of the present invention is arbitrary, but is usually 2.0 to 10.0% by mass, preferably 2.0 to 8% by mass, based on the total amount of the composition. 0.0% by mass, and more preferably 3.0 to 5.0% by mass. When the content of the component (C) is less than 1.0% by mass, a sufficient friction-reducing effect cannot be obtained, and when it exceeds 10.0% by mass, the rubber seal material may be adversely affected. .

The component (D) in the four-stroke engine oil composition for a motorcycle according to the present invention is a friction modifier. (D)
Examples of the component include an organometallic friction modifier such as an organic molybdenum compound, an ashless friction such as an alcohol having at least one alkyl group or alkenyl group having 6 to 30 carbon atoms, a fatty acid or a derivative thereof, and an amine or a derivative thereof. Adjusters and the like can be mentioned, and among these, it is preferable to use one or more organic molybdenum compounds selected from molybdenum dithiophosphate and molybdenum dithiocarbamate. As the molybdenum dithiophosphate, specifically, for example, a compound represented by the following general formula (10) can be used.

Embedded image In the above formula (10), R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ may be the same or different and each have 2 to 30 carbon atoms, preferably 5 to 18 carbon atoms, more preferably 5 to 5 carbon atoms. 1
2 alkyl groups and 6 to 18 carbon atoms, preferably 1 carbon atom
It represents a hydrocarbon group such as 0 to 15 (alkyl) aryl group, and X ¹ , X ² , X ³ and X ⁴ each represent a sulfur atom or an oxygen atom. Here, the alkyl group includes a primary alkyl group, a secondary alkyl group, and a tertiary alkyl group, and these may be linear or branched.
Preferred examples of the alkyl group include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl,
A dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, etc., which may be a primary alkyl group, a secondary alkyl group or a tertiary alkyl group; It may be branched. Preferred examples of the (alkyl) aryl group include phenyl, tolyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, octylphenyl, nonylphenyl,
Examples thereof include a decylphenyl group, an undecylphenyl group, and a dodecylphenyl group. The alkyl group may be a primary alkyl group, a secondary alkyl group, or a tertiary alkyl group, and may be linear or branched. Furthermore, these (alkyl)
The aryl group includes all substituted isomers in which the substitution position of the alkyl group on the aryl group is different. More preferred molybdenum dithiophosphate, specifically,
Molybdenum sulfide diethyl dithiophosphate, molybdenum dipropyl dithiophosphate, molybdenum dibutyl dithiophosphate, molybdenum dipentyl dithiophosphate, molybdenum dihexyl dithiophosphate, molybdenum dioctyl dithiophosphate, molybdenum didecyl dithiophosphate, molybdenum didide disulfide (Butylphenyl) dithiophosphate, molybdenum sulfide (nonylphenyl) dithiophosphate, oxymolybdenum sulfide diethyl dithiophosphate, oxymolybdenum sulfide dipropyl dithiophosphate, oxymolybdenum dibutyl dithiophosphate, oxymolybdenum dipentyl dithiophosphate, oxymolybdenum sulfide Dihexyl dithiophosphate, oxymolybdenum dioctyl dithiophosphate, oxymolybdenum didecyl dithiophosphate, oxymolybdenum didodecyl dithiophosphate, oxymolybdenum di (butylphenyl) dithiophosphate, oxymolybdenum di (butylphenyl) dithiophosphate (nonylphenyl) dithiophosphate It may be chain-like or branched, and the bonding position of the alkyl group of the alkylphenyl group is arbitrary.), And mixtures thereof. In addition, as these molybdenum dithiophosphates, compounds having hydrocarbon groups having different carbon numbers and / or structures in one molecule can be preferably used.

On the other hand, as molybdenum dithiocarbamate, specifically, for example, a compound represented by the following general formula (11) can be used.

Embedded image In the above formula (11), R ²² , R ²³ , R ²⁴ and R ²⁵ may be the same or different and each have an alkyl group having 2 to 24 carbon atoms, preferably 4 to 13 carbon atoms, or 6 to 6 carbon atoms. 2
4, preferably a hydrocarbon group such as an (alkyl) aryl group having 10 to 15 carbon atoms, and X ⁵ , X ⁶ , X ⁷ and X ⁸
Represents a sulfur atom or an oxygen atom, respectively. Here, the alkyl group includes a primary alkyl group, a secondary alkyl group and a tertiary alkyl group, and these may be linear or branched. Preferred examples of the alkyl group include an ethyl group, a propyl group, a butyl group, a pentyl group,
Hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, and the like. It may be a secondary alkyl group or a tertiary alkyl group, and may be linear or branched. Preferred examples of the (alkyl) aryl group include phenyl, tolyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, octylphenyl, nonylphenyl,
Examples thereof include a decylphenyl group, an undecylphenyl group, and a dodecylphenyl group. The alkyl group may be a primary alkyl group, a secondary alkyl group, or a tertiary alkyl group, and may be linear or branched. Furthermore, these (alkyl)
The aryl group includes all substituted isomers in which the substitution position of the alkyl group on the aryl group is different. More preferred molybdenum dithiocarbamate, specifically,
Molybdenum sulfide diethyl dithiocarbamate, molybdenum dipropyl dithiocarbamate, molybdenum dibutyl dithiocarbamate, molybdenum dipentyl dithiocarbamate, molybdenum dihexyl dithiocarbamate, molybdenum dioctyl dithiocarbamate, molybdenum didecyl dithiocarbamate, molybdenum didide disulfide (Butylphenyl) dithiocarbamate, molybdenum di (nonylphenyl) dithiocarbamate, oxymolybdenum sulfide diethyl dithiocarbamate, oxymolybdenum dipropyl dithiocarbamate, oxymolybdenum dibutyl dithiocarbamate, oxymolybdenum dipentyl dithiocarbamate, oxymolybdenum sulfide Dihexyl dithiocarbamate, oxymolybdenum dioctyl dithiocarbamate, oxymolybdenum didecyl dithiocarbamate, oxymolybdenum didodecyl dithiocarbamate, oxymolybdenum di (butylphenyl) dithiocarbamate, oxymolybdenum di (nonylphenyl) dithiocarbamate (alkyl groups are directly It may be chain-like or branched, and the bonding position of the alkyl group of the alkylphenyl group is arbitrary.), And mixtures thereof. As these molybdenum dithiocarbamates, compounds having hydrocarbon groups having different carbon numbers and / or structures in one molecule can also be preferably used. Further, the component (D) of the present invention includes one or more molybdenum dithiophosphates selected from the above.
Mixtures with one or more molybdenum dithiocarbamates in any mixing ratio can also be used as preferred. As the component (D) of the present invention, as the friction modifier other than the above organic molybdenum compound, as described above,
Alcohols having at least one alkyl group or alkenyl group having 6 to 30 carbon atoms, fatty acids or derivatives thereof, amines or derivatives thereof, and the like can be used. This alkyl group or alkenyl group may be linear or branched, but is preferably a compound having 6 to 30, preferably 9 to 24 carbon atoms. When the number of carbon atoms of the alkyl group or the alkenyl group is less than 6 or more than 30, the effect of improving fuel efficiency may be poor. As the alkyl group or alkenyl group,
Specifically, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, Alkyl groups such as henicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triacontyl group (all may be linear or branched); hexenyl group, Heptenyl group,
Octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icosenyl group, henycocenyl group, docosenyl group, tricosenyl group, tricosenyl group , All alkenyl groups such as pentacosenyl group, hexacosenyl group, heptacosenyl group, octacosenyl group, nonacosenyl group and triaconenyl group may be linear or branched, and the position of the double bond is also arbitrary.); Among them, among these, a linear alkyl group or an alkenyl group having 12 to 18 carbon atoms such as a lauryl group, a myristyl group, a palmityl group, a stearyl group, and an oleyl group is particularly preferable from the viewpoint of particularly improving the fuel efficiency. . Particularly preferred as ashless friction modifiers such as alcohols, fatty acids or derivatives thereof, amines or derivatives thereof having at least one alkyl or alkenyl group having 6 to 30 carbon atoms include straight-chains having 12 to 18 carbon atoms. It has an alkyl group or a linear alkenyl group, and specifically, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, linear aliphatic alcohols such as oleyl alcohol; lauric acid, myristic acid, palmitic acid, Linear fatty acids such as stearic acid, oleic acid, and linear fatty acids (coconut oil fatty acids, etc.) derived from various fats and oils; esters (partial esters) of these linear fatty acids with mono- or polyhydric alcohols having 1 to 10 carbon atoms ); These fatty acids and monoamines having 1 to 10 carbon atoms, dia Or salts with polyamines and polyamines; laurylamine, lauryldiethylamine, lauryldiethanolamine, dodecyldipropanolamine, palmitylamine, stearylamine, stearyltetraethylenepentamine, oleylamine, oleylpropylenediamine, oleyldiethanolamine, N-hydroxyethyl Straight-chain aliphatic amine compounds such as oleimidazoline; alkylene oxide adducts of these straight-chain aliphatic amine compounds; these straight-chain aliphatic amine compounds and acid phosphates (eg, di-2-ethylhexyl phosphate); Salts with acid esters (for example, di-2-ethylhexyl phosphite); linear aliphatic amine compounds, alkylene oxide adducts of linear aliphatic amine compounds, and linear aliphatic amine compounds. Modified products obtained by the reaction of boric acid with a salt of a phosphoric acid compound and a (sub) phosphoric acid ester; amides or salts of these linear aliphatic amine compounds with fatty acids having 1 to 10 carbon atoms. . Although the content of the component (D) in the four-stroke engine oil composition for motorcycles of the present invention is arbitrary,
Usually, it is 0.3 to 1.5% by mass, preferably 0.6 to 1.2% by mass, based on the total amount of the composition. When the content of the component (A) is less than 0.3% by mass, the friction coefficient increases after deterioration of the engine oil, so that low fuel efficiency cannot be maintained. When the content exceeds 1.5% by mass, There is a danger of clutch slippage in the wet clutch mechanism.

The component (E) in the four-cycle engine oil composition for a motorcycle according to the present invention is a viscosity index improver. Examples of the viscosity index improver include polymethacrylates, olefin copolymers or hydrides thereof, styrene-diene copolymers, graft copolymers of polymethacrylates and olefin copolymers or hydrides thereof, and mixtures of polymethacrylates with olefin copolymers or hydrides thereof. Is mentioned. Specific examples of the olefin copolymer include a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms.
The diene in the styrene-diene copolymer referred to here includes a diene having 4 to 10 carbon atoms, preferably butadiene and pentadiene. Polymethacrylate,
Although the molecular weight of the olefin copolymer or its hydride, the styrene-diene copolymer, and the graft copolymer of polymethacrylate and the olefin copolymer or its hydride is arbitrary, the weight average molecular weight is usually 50,000 to 1, in polymethacrylate. 0
00,000, 10,000 to 500,000 for olefin copolymer or its hydride, 10,000 to 1,000,000 for styrene-diene copolymer, 50,000 to 1,000 for graft copolymer of polymethacrylate and olefin copolymer. 000. The content of the component (E) in the four-cycle engine oil composition for a motorcycle according to the present invention is 100% of the lubricating oil composition.
The amount is such that the kinematic viscosity at ℃ is 9.3 to 16.5 mm ² / s, preferably 9.5 to 16.3. (E)
When the content of the component is less than 9.3 mm ² / s in kinematic viscosity at 100 ° C. of the lubricating oil composition, a problem occurs in the wear resistance of the valve train and the transmission, and If the kinematic viscosity at 100 ° C. of the composition exceeds 16.5 mm ² / s, fuel efficiency may be poor. The content of the component (E) varies depending on the viscosity of the base oil used in the four-cycle engine oil composition for a motorcycle according to the present invention. As described above, the kinematic viscosity at 100 ° C of the lubricating oil composition is from 9.3 to 9.3.
The amount is 16.5 mm ² / s, but it is usually 4.0 to 10.0% by mass, preferably 6.0 to 9.0% by mass, based on the total amount of the composition.

In the present invention, a four-stroke cycle engine oil composition for motorcycles that is excellent in the effect of reducing oil consumption and fuel economy by merely blending the above components (A) to (E) with a specific base oil. However, for the purpose of further enhancing its various performances, known lubricating oil additives, for example, extreme pressure additives, antiwear agents, rust inhibitors, corrosion inhibitors, pour point depressants, rubber swelling agents, Antifoaming agents, coloring agents and the like can be used alone or in a combination of several types. As the extreme pressure additive and the antiwear agent, for example, a sulfur compound can be used. Specific examples of the sulfur compound include, for example,
Examples include disulfides, sulfurized olefins, sulfurized fats and oils, and the like. Specific examples of the rust inhibitor include alkenyl succinic acid, alkenyl succinate, polyhydric alcohol ester, petroleum sulfonate, dinonyl naphthalene sulfonate, and the like. As the corrosion inhibitor, specifically, for example, benzotriazole,
And thiadiazole-based and imidazole-based compounds. Specific examples of the pour point depressant include, for example, polymethacrylate-based polymers that are compatible with the lubricating base oil used. Specific examples of the antifoaming agent include silicones such as dimethyl silicone and fluorosilicone. The addition amount of these additives is arbitrary, but usually, the content of the antifoaming agent is 0.0005 to 1% by weight, and the content of the corrosion inhibitor is 0.005 to 1 based on the total amount of the lubricating oil composition. %, And the content of other additives is about 0.1 to 15% by weight, respectively.

[0017]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

Examples 1 to 8 and Comparative Examples 1 to 2 Various compositions having the compositions shown in Tables 1 and 2 were prepared (the examples shown in Table 1 were used for 10W-30 oil, The examples shown were adjusted to 10w-40 oils, respectively), and the following performance evaluation tests were performed on these compositions. The results are also shown in Tables 1 and 2.

[Oil Consumption] Based on the evaporability test specified in DIN 51581, the amount of oil reduction after a test at 250 ° C. for 1 hour was measured. [Fuel saving] A motoring test was performed using a water-cooled 4-cylinder motorcycle engine with a displacement of 399 CC and a water temperature of 80 ° C. and an oil temperature of 80 ° C., and the crankshaft torque at that time was reduced to an engine speed of 3000 to 3000 rpm. It was measured every 1000 rpm in the range of 13000 rpm. In addition, Examples 1-4 are the friction reduction rates with respect to Comparative Example 1, and Examples 5-8 are Comparative Example 2.
It is shown by the friction reduction rate against.

[0020]

[Table 1]

[0021]

[Table 2]

As is clear from the results of Tables 1 and 2, the four-stroke cycle engine oil compositions for motorcycles of Examples 1 to 8 according to the present invention are comparative examples 1 using a base oil other than the base oil of the present invention. In comparison with the compositions of Nos. 2 and 3, both of them exhibit low oil consumption and excellent fuel economy. Accordingly, the four-stroke engine oil composition for motorcycles of the present invention has been found to be effective in reducing the total amount of exhaust gas in terms of both the oil consumption and the improved fuel efficiency from the low friction performance, which were lacking in the existing four-stroke engine oil. Is also a major contributor.

[0023]

In summary, according to the present invention, a four-stroke cycle engine oil composition for motorcycles having excellent effects of reducing oil consumption and excellent fuel economy can be obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) C10M 135: 10 133: 18) C10N 10:04 10:12 40:26 F term (reference) 4H104 BF03C BG10C BH04C BH12C CA01C CB08C DA02A DB06C DB07C EA02A EB02 EB05 EB07 EB08 FA02 FA06 LA20 PA44

Claims (1)

[Claims] A kinematic viscosity at 100 ° C. of 3 to 10 as a base oil.
A hydrocarbon-based lubricating base oil having a mm ² / s and a viscosity index of 120 or more, or a mixed base oil containing the base oil in an amount of 15% by mass or more based on the total amount of the base oil, and (A) zinc dialkyldithiophosphate (B ) Metal detergent, (C) Ashless dispersant, (D) Friction modifier (E) The kinematic viscosity of the composition at 100 ° C is from 9.3 to 1.
A four-stroke cycle engine oil composition for motorcycles, comprising a viscosity index improver of 6.5 mm ² / s.