JP5828756B2 - Automotive engine oil - Google Patents

Description

  The present invention relates to an engine oil for automobiles (a lubricating oil composition for an internal combustion engine), and more particularly to an engine oil for automobiles excellent in friction reduction performance, engine cleanup performance, and oxidation stability performance.

  Standards established by API (American Petroleum Institute: American Petroleum Institute) and ILSAC (International Lubricants Standardization Committee), which is organized by Japanese and American automakers, are the most popular classifications of engine oils for automobiles. It is recognized as an engine oil standard that anticipates needs. By the way, in recent years, API-SN and ILSAC GF-5 standards have been established from the viewpoint of enhancing fuel efficiency and sustainability, enhancing engine protecting performance, and enhancing exhaust purification device performance. Yes. Here, the required performance based on the performance described above includes viscosity grade, gelation index, oxidation stability, piston cleanliness, wear resistance, engine cleanliness, valve system wear resistance, bearing corrosion resistance, Fuel efficiency, oil aeration, catalyst poisoning, wear resistance, evaporation, high temperature deposit suppression, filter clogging suppression, defoaming properties, low temperature oil viscosity, shear stability, uniformity / mixing, low temperature corrosion resistance As a result of various additives such as composite fuel compatibility, rubber seal compatibility and the like being mixed, there is a problem with their interaction. Some additives are effective in one performance, while others have a negative effect, making compounding techniques increasingly difficult. In particular, friction modifiers are used to improve fuel economy recently, but these compounds are highly active and are known to adversely affect cleanliness, deposit generation, oxidation stability, and the like.

Here, as a friction modifier, a glyceride compound that contributes to friction reduction performance is frequently used as an ashless friction modifier because it does not contain metal, but if a necessary amount for fuel saving is added, cleanliness and Since there was a problem with oxidation stability, there was a problem that sufficient addition could not be performed. Further, zinc dialkyldithiophosphate (ZDTP) has been conventionally used as an additive most suitable as an antiwear agent and an antioxidant. However, since phosphorus in zinc dialkyldithiophosphate (ZDTP) is also a factor that hurts automobile environmental catalysts, when a large amount of the compound is used, the expected phosphorus content in the future, including the GF-5 standard, is expected. It becomes difficult to meet the demand for reduction. Thus, there is a demand for engine oil that can meet strict specifications expected in the future, including the GF-5 standard, which can exhibit performance such as wear resistance and oxidation stability while ensuring low phosphorus content. Has been. Therefore, Patent Document 1 proposes a lubricating oil for internal combustion engines that can exhibit performance such as wear resistance and oxidation stability while satisfying the requirements of the GF-5 standard.
JP 2005-002214 A

  However, since the new active ingredient described in Patent Document 1 is also a phosphorus-containing compound, it cannot always be said that it can sufficiently meet the demand for low phosphorus type lubricating oil expected in the future, including GF-5. . Therefore, an object of the present invention is to provide means capable of achieving excellent friction reduction performance, engine cleanup performance, and oxidation stability performance even when the amount of phosphorus-containing components is reduced in automotive engine oil. .

（式中、Ｒ１はオレイル基である）で示されるグリセリン１−オレアートと
下記式：

（式中、ＲはＣ８〜Ｃ２２の炭化水素基であり、ｎ及びｍはそれぞれ独立して１又は２である）で示されるモノアルキル又はモノアルケニルアミンエチレンオキサイド付加物からなる群より選択される１種又は２種以上と
を含有することを特徴とする自動車用エンジンオイルである。 As a result of screening various combinations of non-phosphorus components known as additives, the present inventors have combined specific components with specific components, resulting in excellent friction reduction performance and engine cleaning performance. And it was discovered that there are combinations that can achieve oxidation stability performance, and the present invention has been completed. Specifically, the present invention has the following formula:

(Wherein R1 is an oleyl group) and glycerol 1-oleate represented by the following formula:

Wherein R is a C8-C22 hydrocarbon group, and n and m are each independently 1 or 2, and are selected from the group consisting of monoalkyl or monoalkenylamine ethylene oxide adducts An automotive engine oil characterized by containing one or more.

  According to the present invention, the presence of glycerin 1-oleate (GMO, monoolein) and a monoalkyl or monoalkenylamine ethylene oxide adduct having a specific structure allows the GF-5 standard (and more to be expected in the future). There is an effect that it is possible to provide an engine oil having excellent friction reduction performance, engine cleaning performance, and oxidation stability performance that satisfies the performance in the standard that requires high performance. The present invention is particularly suitable for the automotive engine oil composition of the newest API-SN and ILSAC GF-5 standards at present, but is not limited to the engine oil composition of the standards.

BEST MODE FOR CARRYING OUT THE INVENTION

≪Ingredients of automotive engine oil≫
(Base oil)

  As the base oil of the engine oil according to the present embodiment, mineral oil and synthetic oil used for ordinary lubricating oil can be used. In particular, base oils belonging to Group 1, Group 2, Group 3, Group 4, etc. in the API (American Petroleum Institute, American Petroleum Institute) base oil category can be used alone or as a mixture.

For Group 1 base oils, for example, paraffin obtained by applying a suitable combination of solvent refining, hydrorefining, dewaxing, etc. to lubricating oil fractions obtained by atmospheric distillation of crude oil There are mineral oils. The viscosity index is preferably 80 to 120, more preferably 95 to 110. The kinematic viscosity at 100 ° C. is preferably ² to 32 mm ² / s, more preferably 3 to 12 mm ² / s. The total nitrogen content should be less than 50 ppm, preferably less than 25 ppm. Further, the aniline point is preferably from 80 to 150 ° C, more preferably from 90 to 120 ° C.

For Group 2 base oils, for example, paraffinic mineral oil obtained by appropriately combining refining means such as hydrocracking and dewaxing for lubricating oil fractions obtained by atmospheric distillation of crude oil There is. Group 2 base oils refined by hydrorefining methods such as the Gulf Company method have a total sulfur content of less than 10 ppm and an aroma content of 5% or less. The viscosity of these base oils is not particularly limited, but the viscosity index is preferably 90 to 125, more preferably 100 to 120. The kinematic viscosity at 100 ° C. is preferably ² to 32 mm ² / s, more preferably 3 to 12 mm ² / s. The total sulfur content is preferably less than 300 ppm, more preferably less than 100 ppm, and even more preferably less than 10 ppm. The total nitrogen content is also preferably less than 10 ppm, more preferably less than 1 ppm. Further, the aniline point is preferably 80 to 150 ° C, more preferably 100 to 135 ° C.

Group 3 base oils are, for example, paraffinic mineral oils produced by advanced hydrorefining, and waxes produced in the dewaxing process to isoparaffins for lubricating oil fractions obtained by atmospheric distillation of crude oil. Also suitable are base oils refined by the ISODEWAX process for conversion and dewaxing, and base oils refined by the mobile WAX isomerization process. The viscosity of these base oils is not particularly limited, but the viscosity index is preferably 120 to 150, more preferably 120 to 145. Kinematic viscosity at 100 ° C. is, 2~32mm ² / s are preferred, 3 to 12 mm ² / s is more preferable. Moreover, 0-100 ppm is suitable for a total sulfur content, and less than 10 ppm is more suitable. The total nitrogen content is also preferably less than 10 ppm, and more preferably less than 1 ppm. Further, the aniline point is preferably 80 to 150 ° C, more preferably 110 to 135 ° C.

  Examples of synthetic oils include polyolefins, and alkylbenzene, alkylnaphthalene, ester, and the like can be mixed and used as necessary.

The polyolefin includes polymers of various olefins or hydrides thereof. Any olefin may be used, and examples thereof include ethylene, propylene, butene, and α-olefin having 5 or more carbon atoms. In the production of polyolefin, one of the above olefins may be used alone, or two or more may be used in combination. Particularly preferred are polyolefins called polyalphaolefins (PAO), which are Group 4 base oils. The viscosity of these synthetic base oils is not particularly limited, but the kinematic viscosity at 100 ° C. is preferably ² to 32 mm ² / s, more preferably 3 to 12 mm ² / s. Esters include diesters synthesized from dibasic acids such as adipic acid and monohydric alcohols, polyol esters synthesized from polybasic alcohols such as neopentyl glycol, trimethylolpropane, pentaerythritol and monobasic acids, and mixtures thereof. Etc.

GTL (Gas Liquid) oil synthesized by the Fischer-Tropsch method, which is a natural gas liquid fuel technology, has extremely low sulfur and aromatic content compared to mineral oil base oil refined from crude oil. Since the composition ratio is extremely high, the oxidation stability is excellent and the evaporation loss is very small. The viscosity property of the GTL base oil is not particularly limited, but normally, the viscosity index is preferably 120 to 180, more preferably 120 to 150. Kinematic viscosity at 100 ° C. also, 2~32mm ² / s are preferred, 3 to 12 mm ² / s is more preferable. In general, the total sulfur content is preferably less than 10 ppm, and the total nitrogen content is preferably less than 1 ppm. An example of such a GTL base oil product is SHELL XHVI®.

（式中、Ｒ１はオレイル基である）で示される。 (Glycerin 1-oleate)
The glycerin 1-oleate contained as an essential component in the engine oil according to the present embodiment has the following formula:

(Wherein R1 is an oleyl group).

（式中、ＲはＣ８〜Ｃ２２の炭化水素基であり、ｎ及びｍはそれぞれ独立して１又は２である）で示される。この炭素数８〜２２の炭化水素基としては、炭素数８〜２０が好ましく、具体的には例えばオクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基、ノナデシル基、イコシル基等のアルキル基（これらアルキル基は直鎖状でも分枝状でもよい）、オクテニル基、ノネニル基、デセニル基、ウンデセニル基、ドデセニル基、トリデセニル基、テトラデセニル基、ペンタデセニル基、ヘキサデセニル基、ヘプタデセニル基、オクタデセニル基、ノナデセニル基、イコセニル基等のアルケニル基（これらのアルケニル基は直鎖状でも分枝状でもよく、また２重結合の位置も任意で、シス型、トランス型でもよい）が挙げられる。ここで、ｎ及びｍは、それぞれ１であることが好ましい。また、引火点（ＣＯＣ）は２００℃以上であることが好ましい。尚、当該付加物は、１種でも２種以上の混合物でもよい。 (Monoalkyl or monoalkenylamine ethylene oxide adduct)
The monoalkyl or monoalkenylamine ethylene oxide adduct contained as an essential component in the engine oil according to this embodiment has the following formula:

(Wherein R is a C8-C22 hydrocarbon group, and n and m are each independently 1 or 2). The hydrocarbon group having 8 to 22 carbon atoms is preferably 8 to 20 carbon atoms. Specifically, for example, 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 and other alkyl groups (these alkyl groups may be linear or branched), octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group Group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icocenyl group, etc. (These alkenyl groups may be linear or branched, and the position of the double bond is arbitrary. And may be cis type or trans type). Here, n and m are each preferably 1. The flash point (COC) is preferably 200 ° C. or higher. The adduct may be one kind or a mixture of two or more kinds.

(Metal-based detergent)
Examples of metal detergents that can be used in the engine oil according to the present embodiment include alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates, alkaline earth metal naphthenates, and the like. Examples of the alkaline earth metal include calcium and magnesium. These can be used alone or in combination of two or more. Usually, calcium or magnesium sulfonates, phenates and salicylates are preferably used. Alkaline earth metal phenates include alkylphenols having a linear or branched alkyl group having 4 to 30, preferably 6 to 18 carbon atoms, alkylphenol sulfides, alkaline earth metal salts of alkylphenol Mannich reactants, especially calcium A salt is preferably used. Alkaline earth salicylates include alkaline earth metal salts of alkylsalicylic acid having a linear or branched alkyl group having 1 to 30 carbon atoms, preferably 6 to 18, particularly preferably magnesium salts and / or calcium salts. Preferably used. These base numbers can be arbitrarily selected depending on the type and purpose of the lubricating oil to be applied.

(Ashless dispersant)
Examples of the ashless dispersant that can be used in the engine oil according to this embodiment include polybutenyl succinimides, polybutenyl succinamides, benzylamines, and succinates. These dispersants may be borated. This polybutenyl succinimide is obtained from polybutene obtained by polymerizing a high purity isobutene or a mixture of 1-butene and isobutene with a boron fluoride catalyst or an aluminum chloride catalyst, and has a vinylidene structure at the end of the polybutene. In general, 5 to 100 mol% is contained. The polyalkylene polyamine chain preferably contains 2 to 5, particularly 3 to 4 nitrogen atoms from the viewpoint of obtaining an excellent sludge inhibiting effect. In addition, as a derivative of polybutenyl succinimide, a boric acid compound such as boric acid or an oxygen-containing organic compound such as alcohol, aldehyde, ketone, alkylphenol, cyclic carbonate, or organic acid is added to the polybutenyl succinimide. It can be used as a so-called modified succinimide in which a part or all of the remaining amino group and / or imino group is neutralized or amidated by acting. In particular, a boron-containing alkenyl (or alkyl) succinimide obtained by a reaction with a boron compound such as boric acid is excellent in terms of thermal and oxidation stability.

(Antiwear agent)
Examples of the antiwear agent that imparts wear resistance and extreme pressure used in the engine oil according to this embodiment include zinc dithiophosphate (ZnDTP). Examples of ZnDTP generally include zinc dialkyldithiophosphate, zinc diaryldithiophosphate, zinc arylalkyldithiophosphate, and the like. These alkyl groups may be linear or branched. For example, the zinc group of zinc dialkyldithiophosphate is a zinc dialkyldithiophosphate having an alkylaryl group substituted with a primary or secondary alkyl group having 3 to 22 carbon atoms or an alkyl group having 3 to 18 carbon atoms. used. Specific examples of zinc dialkyldithiophosphate include zinc dipropyldithiophosphate, zinc dibutyldithiophosphate, zinc dipentyldithiophosphate, zinc dihexyldithiophosphate, zinc diisopentyldithiophosphate, zinc diethylhexyldithiophosphate, zinc dioctyldithiophosphate, Zinc nonyldithiophosphate, zinc didecyldithiophosphate, zinc didodecyldithiophosphate, zinc dipropylphenyldithiophosphate, zinc dipentylphenyldithiophosphate, zinc dipropylmethylphenyldithiophosphate, zinc dinonylphenyldithiophosphate, didodecylphenyldithiophosphate Zinc, zinc dodecylphenyl dithiophosphate, and the like can be mentioned.

(Metal deactivator)
Examples of metal deactivators that can be used in the engine oil according to this embodiment include benzotriazole derivatives such as benzotriazole and alkyl-tolutriazole, and benzimidazole derivatives such as benzimidazoles and toluimidazoles. In addition, there are indazole derivatives such as tolindazoles, and benzothiazole derivatives such as benzothiazoles and torzothiazoles. Furthermore, a benzoxazole derivative, a thiadiazole derivative, a triazole derivative, etc. are mentioned.

(Antioxidant)
As antioxidant which can be used for the engine oil which concerns on this form, an amine antioxidant and a phenolic antioxidant can be mentioned, for example. As amine-based antioxidants, p, p′-dioctyl-diphenylamine (manufactured by Seiko Chemical Co., Ltd .: non-flex OD-3), p, p′-di-α-methylbenzyl-diphenylamine, Np-butylphenyl- Dialkyl-diphenylamines such as Np′-octylphenylamine, monoalkyldiphenylamines such as mono-t-butyldiphenylamine and monooctyldiphenylamine, di (2,4-diethylphenyl) amine, di (2-ethyl-4 -Bis (dialkylphenyl) amines such as nonylphenyl) amine, alkylphenyl-1-naphthylamines such as octylphenyl-1-naphthylamine, Nt-dodecylphenyl-1-naphthylamine, 1-naphthylamine, phenyl-1- Naphtylamine, phenyl-2-naphthyla , N-hexylphenyl-2-naphthylamine, aryl-naphthylamines such as N-octylphenyl-2-naphthylamine, N, N′-diisopropyl-p-phenylenediamine, N, N′-diphenyl-p-phenylenediamine, etc. Phenylenediamines, phenothiazines (manufactured by Hodogaya Chemical Co., Ltd .: Phenothiazine), and phenothiazines such as 3,7-dioctylphenothiazine. Examples of phenolic antioxidants include 2-t-butylphenol, 2-t-butyl-4-methylphenol, 2-t-butyl-5-methylphenol, 2,4-di-t-butylphenol, 2,4- Dimethyl-6-t-butylphenol, 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone (manufactured by Kawaguchi Chemical Co., Ltd .: Antage DBH), 2,6-di-t-butylphenol such as 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol 2,6-di-tert-butyl-4-, such as -4-alkylphenols, 2,6-di-tert-butyl-4-methoxyphenol, 2,6-di-tert-butyl-4-ethoxyphenol There is a Turkey alkoxy phenols. 3,5-di-t-butyl-4-hydroxybenzyl mercapto-octyl acetate, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by Yoshitomi Pharmaceutical Co., Ltd.) Yoshinox SS), n-dodecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2'-ethylhexyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Alkyl-3- () such as propionate, benzenepropanoic acid 3,5-bis (1,1-dimethyl-ethyl) -4-hydroxy-C7-C9 side chain alkyl ester (manufactured by Ciba Specialty Chemicals: Irganox L135) 3,5-di-t-butyl-4-hydroxyphenyl) propionates, 2,6-di-t-butyl-α-di Tylamino-p-cresol, 2,2′-methylenebis (4-methyl-6-t-butylphenol) (manufactured by Kawaguchi Chemical Co .: Antage W-400), 2,2′-methylenebis (4-ethyl-6-t-) And 2,2′-methylenebis (4-alkyl-6-t-butylphenol) such as (Butylphenol) (manufactured by Kawaguchi Chemical Co., Ltd .: Antage W-500). Further, 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) (manufactured by Kawaguchi Chemical Co., Ltd .: Antage W-300), 4,4′-methylenebis (2,6-di-tert-butylphenol) (shell) -Japan company make: Ionox220AH), 4,4'-bis (2,6-di-t-butylphenol), 2, 2- (di-p-hydroxyphenyl) propane (shell Japan company make: bisphenol A), 2,2-bis (3,5-di-t-butyl-4-hydroxyphenyl) propane, 4,4′-cyclohexylidenebis (2,6-t-butylphenol), hexamethylene glycol bis [3- ( 3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals: Irganox L109), triethyle Glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] (manufactured by Yoshitomi Pharmaceutical Co., Ltd .: Tominox 917), 2,2′-thio- [diethyl-3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals: Irganox L115), 3,9-bis {1,1-dimethyl-2- [3- (3-t-butyl -4-hydroxy-5-methylphenyl) propionyloxy] ethyl} 2,4,8,10-tetraoxaspiro [5,5] undecane (Sumitomo Chemical: Sumilizer GA80), 4,4'-thiobis (3-methyl -6-t-butylphenol) (manufactured by Kawaguchi Chemical Co., Ltd .: Antage RC), 2,2'-thiobis (4,6-di-t-butyl-resorcin) There is Lumpur class. Tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (manufactured by Ciba Specialty Chemicals: Irganox L101), 1,1,3-tris (2-methyl) -4-hydroxy-5-t-butylphenyl) butane (Yoshitomi Pharmaceutical Co., Ltd .: Yoshinox 930), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4 -Hydroxybenzyl) benzene (manufactured by Shell Japan: Ionox 330), bis- [3,3′-bis- (4′-hydroxy-3′-t-butylphenyl) butyric acid] glycol ester, 2- (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) methyl-4- (2 ", 4" -di-tert-butyl-3 "-hydroxyphenyl) methyl Of polyphenols such as -6-tert-butylphenol, 2,6-bis (2'-hydroxy-3'-tert-butyl-5'-methyl-benzyl) -4-methylphenol, pt-butylphenol and formaldehyde Examples include condensates and phenol aldehyde condensates such as a condensate of pt-butylphenol and acetaldehyde.

(Viscosity index improver)
Examples of the viscosity index improver that can be used in the engine oil according to the present embodiment include non-dispersions of olefin polymers such as polymethacrylates, ethylene-propylene copolymers, styrene-diene copolymers, polyisobutylene, and polystyrene. Examples thereof include a type viscosity index improver and a dispersion type viscosity index improver obtained by copolymerizing a nitrogen-containing monomer.

(Defoamer)
Examples of the antifoaming agent that can be used for the engine oil according to the present embodiment include organosilicates such as dimethylpolysiloxane, diethyl silicate, and fluorosilicone, and non-silicone antifoaming agents such as polyalkyl acrylate.

≪Composition of engine oil for automobiles≫
(Amount of glycerin 1-oleate in engine oil)
The content of glycerin 1-oleate is preferably 0.1 to 2.0% by mass and 0.25 to 1.5% by mass based on the total mass of the engine oil composition. Is more suitable, and it is still more suitable that it is the range of 0.5-1.2 mass%.

(Amount of monoalkyl or monoalkenylamine ethylene oxide adduct in engine oil)
The content of the monoalkyl or monoalkenylamine ethylene oxide adduct (the total amount when there are plural types) is determined based on the total mass of the engine oil composition, alone or in combination, and the total amount of the engine oil composition. It is preferably 0.1 to 2.0% by mass, more preferably 0.2 to 1.5% by mass, based on mass, and 0.2 to 1.0% by mass. More preferably, it is in the range.

(Amount of other components in engine oil)
The preferred addition amount of other components that may be added to the engine oil composition according to this embodiment will be described. First, the preferred addition amount of the antioxidant is in the range of 0.01 to 2% by mass based on the total mass of the engine oil composition, alone or in combination. A suitable addition amount of the metal deactivator is in a range of 0.01 to 0.5% by mass based on the total mass of the engine oil composition, alone or in combination. A suitable addition amount of the antiwear agent (for example, ZnDTP) is 0.01 to 0.10% by mass, more preferably 0, based on the total mass of the engine oil composition, based on the total mass of the engine oil composition. The range is from 0.05 to 0.08% by mass. If the weight of elemental phosphorus contained in ZnDTP is less than 0.01% by mass with respect to the total weight of engine oil, sufficient wear resistance cannot be obtained, and if the concentration is higher than 0.10% by mass, the exhaust gas purification catalyst for automobiles cannot be obtained. The effect of poisoning increases. The preferred addition amount of the viscosity index improver is in the range of 0.05 to 20% by mass based on the total mass of the engine oil composition, alone or in combination. The preferred addition amount of the antifoaming agent is in the range of 0.0001 to 0.01% by mass based on the total mass of the engine oil composition, alone or in combination. The preferred addition amount of the metallic detergent is 0.05 to 0.3% by mass, more preferably 0.1 to 0.2% by mass, based on the total mass of the engine oil composition, alone or in combination. %. The preferred addition amount of the ashless dispersant is such that it provides 0.01 to 0.3% by mass of nitrogen, alone or in combination, based on the total mass of the engine oil composition.

≪Physical properties of automotive engine oil≫
The engine oil composition according to this embodiment is based on an engine oil composition having the same composition except that it does not contain “glycerin 1-oleate” and “monoalkyl or monoalkenylamine ethylene oxide adduct”. % Friction coefficient (reciprocating friction coefficient at 80 ° C.) is preferably low (improved), and it is more preferable that the coefficient of friction (reciprocating friction coefficient at 80 ° C.) is low (improved). Furthermore, the engine oil composition according to this embodiment preferably has a friction coefficient (reciprocating friction coefficient) in the range of 0.100 or less. Moreover, the score by the hot tube test (engine cleanliness test: 280 ° C.) is preferably 5 or more, more preferably 7 or more, and even more preferably 8 or more. Score by the hot tube test (engine cleanliness test) : 295 ° C.) is preferably 2 or more, more preferably 3.0 or more, and even more preferably 3.5 or more. Further, the rate of change in viscosity with respect to the kinematic viscosity at 100 ° C. by the oxidation stability test (ISOT) is preferably less than 0.5%, more preferably less than 0.25%. Moreover, the acid value change by an oxidation stability test (ISOT) is preferably less than 0.3 mgKOH / g, more preferably less than 0.2 mgKOH / g, and even more preferably less than 0.15 mgKOH / g.

≪Ingredients≫
(Base oil)
The base oils used in Examples and Comparative Examples have the properties shown in Table 1. Here, kinematic viscosity (@ 40 ° C) and kinematic viscosity (@ 100 ° C) are JIS
K 2283 “crude oil and petroleum products—kinematic viscosity test method and viscosity index calculation method”. The viscosity index is JIS-K-2283.
Crude oil and petroleum products-values obtained according to the kinematic viscosity test method and viscosity index calculation method. JIS K 2269 was used for the pour point (PP), JIS K 2541 (radiation excitation method) for the sulfur content, and JIS K 2609 (chemiluminescence method) for the nitrogen content.

(Glycerin 1-oleate)
The physical properties of glycerin 1-oleate (GMO) used in Examples and Comparative Examples are as follows. Here, the flash point is a value obtained by the Cleveland open type (COC) of JIS K2265. The hydroxyl value is a value measured by a pyridine-acetyl chloride method according to JIS K 0070.
Melting point: 41 ° C
Kinematic viscosity @ 100 ° C: 11mm ² / s
Flash point (COC): 220 ° C
Hydroxyl value: 222mgKOH / g

(Amine ethylene oxide adduct)
The physical properties and the like of those used in Examples and Comparative Examples as the amine ethylene oxide adduct (DEA) are as follows. Here, the base number is JIS
It is a value measured by the K2501 method (perchloric acid method).
R = oleyl group, [CH ₃ (CH ₂ ) ₇ —CH═CH— (CH ₂ ) ₇ −]
n = 1
m = 1
Melting point: 31 ° C
Density: 0.92 g / cm ³
Kinematic viscosity @ 40 ° C: 69mm ² / s
Flash point (COC): 230 ° C
Hydroxyl value: 322 mgKOH / g
Base number: 160mgKOH / g

(DI package additive)
The main components of the DI package additive (corresponding to GF-5) used in the examples and comparative examples are as follows {in addition, the content of each component is calculated with the engine oil in the examples as 100% by mass ( In the examples, the additive is added by 9.05% by mass)}.
Metal detergent: Ca salicylate (Ca content = 0.21 mass%, base number (HCl method) = 6.7 mgKOH / g)
Ashless dispersant: polybutenyl succinimide (N content = 0.095 mass%, B content = 0.006 mass%)
Zinc dialkyldithiophosphate (secondary alkyl type, Zn content = 0.085 mass%, P content = 0.074 mass%)
Metal deactivator antioxidant: Aromatic amine compounds, hindered phenol compounds

(Viscosity index improver)
Viscoplex 6-6955 (Polymethacrylate viscosity index improver)
The dispersant-viscosity index (VI) improver used is a polymethacrylate copolymer obtained from Romax under the trade name “VISCOPLEX 6-6955”.

(Defoamer)
3% by weight solution diluted with kerosene using polydimethylsiloxane as solvent

≪Evaluation method≫
(Reciprocating friction test conditions)
In order to see the friction characteristics, it evaluated using the CAMERON-PLINT * TE77 test machine used by ASTM-G-133 (American Society for Testing and Materials). The upper test piece is made of SK-3 and has a cylindrical shape with a diameter of 6 mm and a length of 16 mm. The lower test piece is a plate made of SK-3, and the test temperature is 80 ° C., the load is 300 N, the amplitude is 15 mm, and the reciprocating frequency is 10 Hz. A minute test was performed and the average value of the coefficient of friction measured during the last stable minute was noted. A smaller friction coefficient indicates better friction reduction.

(Hot tube test)
Implemented based on the Petroleum Institute Act, JPI-5S-55-99. The test temperature was performed at two points of 280 ° C. and 295 ° C. The Japanese diesel engine oil standard JASO M355: 2008 also uses a test temperature of 280 ° C as an evaluation test for the prevention of high temperature deposits. ing. The higher the score, the better the high-temperature deposition prevention property.

(Oxidation stability test (ISOT))
According to JIS-K-2514, test temperature: 165.5 ° C., test time: 96 hours, and as evaluation items, kinematic viscosity increase rate at 100 ° C. after test, change in acid value, mgKOH / g are measured The results are shown in Table 3.

<< Examples 1-4 and Comparative Examples 1-5 >>
Table 2 shows compositions of engine oils according to Examples 1 to 4 and Comparative Examples 1 to 5. Table 3 shows the properties of the engine oil according to Examples 1 to 4 and Comparative Examples 1 to 5. Here, the acid value is a value measured according to JIS K2501.

  Table 4 shows the results of the evaluation of the friction reduction performance of the engine oil according to the example and the comparative example. As can be seen from the table, increasing the GMO decreased the coefficient of friction and recognized a fuel saving effect. On the other hand, the DEA itself did not show fuel efficiency due to the friction coefficient reducing effect. When GMO and DEA were combined, a good friction coefficient reduction effect was obtained. It is presumed that the nitrogen atom of DEA and the hydrogen atom of the hydroxyl group of GMO are hydrogen-bonded to form a strong and dense adsorption film on the surface by DEA and GMO, and the friction coefficient is further reduced.

≪Piston cleanliness evaluation≫
Table 5 shows the results of the piston cleanliness evaluation of the engine oil according to the example and the comparative example. As can be seen from the table, in the combination of GMO and DEA, no significant difference in piston cleanliness was observed in the hot tube test at 280 ° C. On the other hand, at a severe high temperature of 295 ° C., the overall cleanliness deteriorated, and the cleanliness score decreased. In particular, since GMO has a double bond in the oleyl group, it tends to oxidize and deteriorate at high temperatures. As the amount of GMO added increased, the cleanliness clearly decreased. However, the cleanliness improved dramatically when the DEA was combined. This is presumably because the cleaning effect of the surfactant DEA did not deteriorate even at high temperatures, and the addition effect was observed.

≪Heat and oxidation stability evaluation≫
Tables 6 and 7 show the results of the piston cleanliness evaluation of the engine oil according to Examples and Comparative Examples. First, as can be seen from Table 6, the rate of change in viscosity at 100 ° C. after ISOT increased in proportion to the amount added in the case of GMO, which had an adverse effect on the thermal and oxidative deterioration of the sample oil. This is presumably because oxidation and deterioration are likely to occur in the double bond portion of the oleyl group described above at a high temperature. Addition of 0.5 wt% DEA to the sample oil containing GMO dramatically suppressed oxidative degradation and suppressed and improved viscosity increase. On the other hand, in the case of DEA alone, as the addition amount increases, the viscosity tends to increase, but the degree is very small. Also in this test, when GMO and DEA were combined, the increase in viscosity due to thermal oxidative degradation was suppressed and decreased. It can be seen that the combined effect (synergistic effect) of GMO and DEA is working. Although the reason for this synergistic effect is not clearly understood, it was considered that DEA deactivated the surface of the catalytic metals Cu and Fe used in the ISOT test to suppress oxidative degradation.

  Table 7 shows the results of measuring the acid value of the deteriorated oil after ISOT. As can be seen from Table 7, as the amount of GMO added increases, the acid value increases, so that acidic substances are generated. On the other hand, there was a slight tendency for the acid value to increase as DEA increased in addition. When GMO and DEA were combined, there was almost no increase in acid value. From this, the existence of the combination effect is clear.

Claims (2)

Following formula:

(Wherein R1 is an oleyl group) and glycerol 1-oleate represented by the following formula:

Wherein R is a C8-C22 hydrocarbon group, and n and m are each independently 1 or 2, and are selected from the group consisting of monoalkyl or monoalkenylamine ethylene oxide adducts 1 type or 2 types or more
A base oil belonging to Group 3 in the API base oil category, and
Based on the total mass of the oil, the content of glycerin 1-oleate is 0.5 to 2.0.
An engine oil for automobiles , wherein the content of the adduct is 0.5 to 2.0% by mass . Based on the total mass of the oil, the content of glycerin 1-oleate is 0.5 to 1.2% by mass, and the content of the adduct is 0.1. The engine oil for automobiles according to claim 1, which is 5 to 1.0 mass%.