JP2008523188A - Lubricating oil composition - Google Patents

Abstract

A lubricating oil composition comprising an ashless friction modifier that exhibits good friction reduction and fuel economy.
A lubricating oil composition comprising a base oil, oleylamide and one or more ether compounds, and a method for lubricating an internal combustion engine, wherein the composition is applied to an internal combustion engine.
[Selection] Figure 1

Description

  The present invention relates to a lubricating oil composition, and more particularly to a lubricating oil composition suitable for lubricating internal combustion engines and having improved friction reduction and fuel economy.

Due to the increasingly stringent automotive standards for emissions and fuel efficiency, there is an increasing demand for engine manufacturers and lubricant formulators for effective solutions to improve fuel economy.
Optimizing lubricants using high performance base stocks and new additives provides a flexible solution to the growing challenge.

  Lubricants (also known as friction modifiers) are important ingredients for reducing fuel consumption, and various such additives are already known in the art.

  Friction modifiers are conveniently divided into two categories: metal-containing friction modifiers and ash (organic) free friction modifiers. Organomolybdenum compounds belong to the most common metal-containing friction modifiers. Common organic molybdenum compounds include molybdenum dithiocarbamate (MoDTC), molybdenum dithiophosphate (MoDTP), molybdenum amine, molybdenum alcoholate, and molybdenum alcohol amide. WO-A-98 / 26030, WO-A-99 / 31113, WO-A-99 / 47629 and WO-A-99 / 66013 describe trinuclear molybdenum compounds for lubricating oil compositions.

However, low ash lubricating oil compositions require increased drive to reduce friction and improve fuel economy using friction modifiers that are free of ash (organic).
Ash-free (organic) friction modifiers usually contain esters of fatty acids and polyhydric alcohols, fatty acid amides, amines derived from fatty acids, and organic dithiocarbamate or organic dithiophosphate compounds.

Utilizing a synergistic mechanism with specific combinations of lubricating oil additives, the performance characteristics of lubricating oil were further improved.
WO-A-99 / 50377 discloses a lubricating oil composition and states that the use of a trinuclear molybdenum compound in combination with an oil-soluble dithiocarbamate significantly improves fuel economy.

EP-A-1041135 discloses the use of a succinimide dispersant in combination with molybdenum dialkyldithiocarbamate to improve friction reduction in diesel engines.
US-B1-6562765 discloses a lubricating oil composition and states that an unexpectedly low coefficient of friction is obtained due to the synergistic nature of the oxymolybdenum nitrogen dispersant complex and oxymolybdenum dithiocarbamate.

EP-A-1367116, EP-A-0799883, EP-A-0747464, US-A-3933659 and EP-A-335701 disclose lubricating oil compositions comprising various combinations of ashless friction modifiers. Yes.
WO-A-92 / 02602 discloses a lubricating oil composition for an internal combustion engine comprising a blend of ashless friction modifiers and states that the blend exhibits a synergistic effect on fuel economy.

The blend disclosed in WO-A-92 / 02602 comprises (a) an amine / amide friction modifier prepared by reaction of one or more acids with one or more amines and (b) one or more acids. A combination with an ester / alcohol friction modifier prepared by reaction with one or more polyols.
US-A-5286394 discloses a lubricating oil composition and a method for reducing the fuel consumption of an internal combustion engine.

  The lubricating oil composition disclosed in this patent comprises a small amount of a friction improving polar surface selected from a large number of oils having a lubricating viscosity and a number of compounds including polyol monoesters and higher esters and aliphatic amides. Active organic compounds. Examples of such compounds include glycerol monooleate and oleamide (ie, oleylamide).

However, the current policy on reducing the friction of fuel economy oils does not fully meet the ever-increasing fuel economy target set by the Original Equipment Manufacturer (OEM).
For example, molybdenum friction modifiers are superior to ashless friction modifiers in the boundary regime, and there are challenges in using similar ashless friction modifiers to approach similar friction improvement levels.

Thus, considering the ever increasing fuel economy demands on engines, there is still a need to further improve the friction reduction and fuel economy of internal combustion engines using low ash lubricating oil compositions.
Thus, further improvements in the performance of known ashless friction modifiers and the performance of known combinations of ashless friction modifiers, particularly polyol ester friction modifiers and fatty acid amides commonly used in the art It is desirable to further improve the friction reducing performance of ashless friction modifier combinations with polyol esters (eg, a combination of oleylamide and glycerol monooleate).
WO-A-98 / 26030 WO-A-99 / 31113 WO-A-99 / 47629 WO-A-99 / 66013 WO-A-99 / 50377 EP-A-1041135 US-B1-6562765 EP-A-1367116 EP-A-0799883 EP-A-0747464 US-A-3933659 EP-A-335701 WO-A-92 / 02602 US-A-5286394 EP-A-776959 EP-A-668342 WO-A-97 / 21788 WO-00 / 15736 WO-00 / 14188 WO-00 / 14187 WO-00 / 14183 WO-00 / 14179 WO-00 / 08115 WO-99 / 41332 EP-1029029 WO-01 / 18156 WO-01 / 57166 Japanese patent no. 13677796 Japanese patent no. 1667140 Japanese patent no. 1302811 Japanese patent no. 1743435

  A lubricating oil composition comprising an ashless friction modifier that exhibits good friction reduction and fuel economy in the present invention has now been unexpectedly found.

  Accordingly, the present invention provides a lubricating oil composition comprising a base oil, oleylamide and one or more ether compounds.

  In the present invention, “ether compound” means a saturated or unsaturated hydrocarbon compound having one or more ether bonds and optionally one or more hydroxyl groups inside, but not containing any other functional group. To do.

The selection of the ether compound used in the present invention is not limited. However, the ether compound is preferably an acyclic compound.
Ether compounds that can be conveniently used in the present invention are represented by the formula (I):

(Provided that R ¹ , R ² and R ³ are each independently hydrogen; an alkyl group having 10 to 30 carbon atoms, preferably 16 to 22 carbon atoms; and an alkyl group having 10 to 30 carbon atoms, preferably 16 to 22 carbon atoms. (Selected from saturated hydrocarbon groups)
It is a compound of this.

Preferred ether compounds are those in which R ¹ is an alkyl or unsaturated hydrocarbon group having 10 to 30 carbon atoms, more preferably 16 to 22 carbon atoms, and R ² and R ³ are hydrogen.
Other preferred ether compounds are those in which R ¹ and R ² are alkyl or unsaturated hydrocarbon groups having 10 to 30 carbon atoms, more preferably 16 to 22 carbon atoms, and R ³ is hydrogen.

Preferred ether compounds also include compounds in which R ¹ and R ³ are alkyl or unsaturated hydrocarbon groups having 10 to 30 carbon atoms, more preferably 16 to 22 carbon atoms, and R ² is hydrogen.
Preferable ether compounds also include compounds in which R ¹ , R ² and R ³ are each independently selected from alkyl or unsaturated hydrocarbon groups having 10 to 30 carbon atoms, more preferably 16 to 22 carbon atoms.

In a preferred embodiment of the invention, the lubricating oil composition of the invention contains a mixture of the preferred one or more ether compounds.
Examples of ether compounds that can be conveniently used in the present invention include glycerol oleyl monoether, glycerol oleyl diether, glycerol oleyl triether, glycerol stearyl monoether, glycerol stearyl diether, glycerol stearyl triether and mixtures thereof. .

Preferred ether compounds include those obtained from Asahi Denka Kogyo Co. Ltd. under the trade name “ADEKA FM-618C”.
In an embodiment of the present invention, the one or more ether compounds are 0.1 to 5 wt%, more preferably 0.5 to 4 wt%, most preferably 1 to 1.5 wt%, based on the total weight of the lubricating oil composition. Present in the weight percent range.

In a preferred embodiment of the present invention, oleylamide is 0.05 to 0.5 wt%, more preferably 0.1 to 0.4 wt%, most preferably 0.15 to 0.5 wt%, based on the total weight of the lubricating oil composition. It exists in the range of 0.3% by weight.
In a preferred embodiment, the lubricating oil composition of the present invention further contains one or more nitrile compounds.

  Nitrile compounds that can be conveniently used in the present invention are saturated or unsaturated hydrocarbon compounds having one or more cyano groups (—C═N) but free of any additional functional group substituents.

Particularly preferred nitrile compounds that can be conveniently used in the present invention are branched or linear, saturated or unsaturated aliphatic nitriles.
A nitrile compound having preferably 8 to 24, more preferably 10 to 22, and most preferably 10 to 18 carbon atoms is preferable.

Particularly preferred nitrile compounds are saturated or unsaturated linear aliphatic nitriles having 8 to 24 carbon atoms, more preferably 10 to 22, most preferably 10 to 18 carbon atoms.
Examples of nitrile compounds that can be conveniently used in the present invention include coconut oil fatty acid nitrile, oleyl nitrile, decane nitrile and beef tallow nitrile.

Preferred nitrile compounds that can be conveniently used in the present invention include the trade name “ARNEEL 12” (also known as trade name “ARNEEL C”) from Akzo Nobel (a mixture of saturated nitriles of C10, C12, C14 and C16). Available under the trade name "ARNEEL O" (oleylnitrile) from Akzo Nobel, and "ARNEEL 10D" (decane nitrile), "ARNEEL T" (beef tallow) from Akzo Nobel Nitriles) and “ARNEEL M” (C _16-22 nitriles).

  In an embodiment of the present invention, the one or more nitrile compounds are preferably 0.1 to 0.8% by weight, more preferably 0.2 to 0.6% by weight, most preferably based on the total weight of the lubricating oil composition. Preferably it is present in an amount ranging from 0.3 to 0.5% by weight.

The total amount of the base oil incorporated into the lubricating oil composition of the present invention is preferably 60 to 92% by weight, more preferably 75 to 90% by weight, most preferably 75 to 90% by weight based on the total weight of the lubricating oil composition. It is present in an amount in the range of 88% by weight.
There is no restriction | limiting in particular about the base oil used by this invention, Conventionally well-known various mineral oil and synthetic oil can be used conveniently.

The base oil used in the present invention may conveniently contain a mixture of one or more mineral oils and / or a mixture of one or more synthetic oils.
Mineral oils include liquid petroleum and paraffinic, naphthenic or paraffin / naphthene mixed solvent-treated or acid-treated lubricating mineral oils that can be further refined by hydrofinishing and / or dewaxing.

  Naphthenic base oils have a low viscosity index (VI) (generally 40-80) and a low pour point. Such base oils are produced from feedstocks rich in naphthenes and low wax content, and are mainly used in lubricating oils where color tone and color stability are particularly important and VI and oxidative stability are the next most important. The

Paraffinic base oils have a high VI (generally> 95) and a high pour point. Such base oils are made from paraffin-rich feedstocks and are used in lubricating oils where VI and oxidative stability are important.
Fischer-Tropsch derived base oil can be conveniently used as a base oil for the lubricating oil composition of the present invention, for example, EP-A-776959, EP-A-668342, WO-A-97 / 21788, WO-00 / 15736. WO-00 / 14188, WO-00 / 14187, WO-00 / 14183, WO-00 / 14179, WO-00 / 08115, WO-99 / 41332, EP-1029029, WO-01 / 18156 and WO-01 / 57166.

By a synthesis method, it is possible to make a molecule from a simple substance or obtain a molecule having a structure modified so as to have a required fine characteristic.
Synthetic oils include hydrocarbon oils such as olefin oligomers (PAO), dibasic acid esters, polyol esters and dewaxed waxy raffinates. Synthetic hydrocarbon base oils sold under the trade name “XHVI” by the Royal Dutch / Shell group can be used conveniently.

The base oil is preferably composed of mineral and / or synthetic oils, as measured by ASTM D2007, containing more than 80% by weight of saturates, preferably more than 90% by weight.
The base oil is preferably measured by ASTM D2622, ASTM D4294, ASTM D4927, or ASTM D3120 and calculated as elemental sulfur, and preferably contains less than 1.0% by weight of sulfur, preferably less than 0.1% by weight.

The viscosity index of the base oil is preferably greater than 80, more preferably greater than 120, as measured by ASTM D2270.
Kinematic viscosity at 100 ° C. of the base oil preferably ranges 2~80mm ² / s, more preferably 3~70mm ² / s, most preferably 4~50mm ² / s.

The total amount of phosphorus in the lubricating oil composition of the present invention is preferably 0.04 to 0.1% by weight, more preferably 0.04 to 0.09% by weight, most preferably based on the total weight of the lubricating oil composition. Is in the range of 0.045 to 0.09% by weight.
The sulfated ash content of the lubricating oil composition of the present invention is preferably 1.0% by weight or less, more preferably 0.75% by weight or less, and most preferably 0.7% by weight, based on the total weight of the lubricating oil composition. % Or less.

The sulfur content of the lubricating oil composition of the present invention is preferably 1.2 wt% or less, more preferably 0.8 wt% or less, most preferably 0.2 wt% or less, based on the total weight of the lubricating oil composition. It is.
The lubricating oil composition of the present invention comprises an antioxidant, an antiwear agent, a cleaning agent, a dispersant, a friction modifier, a viscosity index improver, a pour point depressant, a corrosion inhibitor, an antifoaming agent, and a seal fixing agent or Additional additives such as seal matching agents may further be included.

Antioxidants that can be conveniently used include those selected from amine-based antioxidants and / or phenol-based antioxidants.
In an embodiment, the antioxidant is preferably 0.1 to 5.0% by weight, more preferably 0.3 to 3.0% by weight, most preferably 0.5 to 0.5%, based on the total weight of the lubricating oil composition. It is present in an amount in the range of 1.5% by weight.
Amine antioxidants that can be conveniently used include alkylated diphenylamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine and alkylated α-naphthylamine.

  Preferred amine antioxidants include p, p′-dioctyl-diphenylamine, p, p′-di-α-methylbenzyl-diphenylamine and Np-butylphenyl-Np′-octylphenylamine. Dialkyldiphenylamines; monoalkyldiphenylamines such as mono-t-butyldiphenylamine and mono-octyldiphenylamine; bis (such as di- (2,4-diethylphenyl) amine and di (2-ethyl-4-nonylphenyl) amine Dialkylphenyl) amine; alkylphenyl-1-naphthylamines such as octylphenyl-1-naphthylamine and nt-dodecylphenyl-1-naphthylamine; 1-naphthylamine; phenyl-1-naphthylamine, phenyl-2-naphthylamine, N— Aryl naphthylamines such as xylphenyl-2-naphthylamine and N-octylphenyl-2-naphthylamine; N, N′-diisopropyl-p-phenylenediamine and N, N′-diphenyl-p-phenylenediamine; and phenothiazine and 3, And phenothiazines such as 7-dioctylphenothiazine.

  Preferred amine antioxidants include the following trade names: “Sonoflex OD-3” (from Seiko Kagaku Co.), “Irganox L-57” (from Ciba Specialty Chemicals Co.) and phenothiazine (from Hodogaya Kagaku Co.). ).

  Examples of phenolic antioxidants that can be conveniently used include C5-C9 branched alkyl esters of 3,5-bis (1,1-dimethyl-ethyl) -4-hydroxy-benzenepropionic acid; 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-tert-butyl-4-methoxyphenol; 2,5-di-tert-butylhydroquinone; 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methyl 2,6-di-tert-butyl-4-alkylphenols such as phenol and 2,6-di-tert-butyl-4-ethylphenol; 2,6-di-tert-butyl 2,6-di-tert-butyl-4-alkoxyphenol such as 4-methoxyphenol and 2,6-di-tert-butyl-4-ethoxyphenol; 3,5-di-tert-butyl-4-hydroxy Benzyl mercaptooctyl acetate; n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, n-butyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) ) Alkyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) such as propionate and 2'-ethylhexyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) Propionate; 2,6-di-t-butyl-α-dimethylamino-p-cresol; 2,2′-methylenebis (4-methyl-6-t-butyl) Phenol) and 2,2′-methylenebis (4-alkyl-6-tert-butylphenol) such as 2,2′-methylenebis (4-ethyl-6-tert-butylphenol); 4,4′-butylidenebis (3- Methyl-6-tert-butylphenol), 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 2,2- ( Di-p-hydroxyphenyl) propane, 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], triethylene glycol bis [3- (3-t-butyl) -4-hydroxy-5-methylphenyl) propionate], 2,2'-thio- [diethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis { 1,1-dimethyl-2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} 2,4,8,10-tetraoxaspiro [5,5] undecane, Bisphenols such as 4,4′-thiobis (3-methyl-6-tert-butylphenol) and 2,2′-thiobis (4,6-di-tert-butylresorcinol); tetrakis [methylene-3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, bis- [3,3′-bis (4′-hydroxy-3′-t) -Butylphenyl) butyric acid] glycol ester, 2- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) methyl-4- (2 ", 4" -di-t-butyl-3 "-hydroxy Poly) phenols such as phenyl) methyl-6-tert-butylphenol and 2,6-bis (2′-hydroxy-3′-tert-butyl-5′-methylbenzyl) -4-methylphenol; and pt-butylphenol -Formaldehyde condensates and pt-butylphenol-acetaldehyde condensates.

  Preferred phenolic antioxidants include the following trade names: “Irganox L-135” (from Ciba Specialty Chemicals Co.), “Yoshinox SS” (from Yoshitomi Seiyaku Co.), “Antage W-400” (Kawagudhi Kagaku Co.), “Antage W-500” (from Kawagudhi Kagaku Co.), “Antage W-300” (from Kawagudhi Kagaku Co.), “Irganox L109” (from Ciba Specialty Chemicals Co.), “Tominox 917” (From Yoshitomi Seiyaku Co.), “Irganox L115” (from Ciba Specialty Chemicals Co.), “Sumilizer GA80” (from Sumitomo Kagaku), “Antage RC” (from Kawagudhi Kagaku Co.), “Irganox L101” (Ciba Specialty) Chemicals Co.) and “Yoshinox 930” (from Yoshitomi Seiyaku Co.).

The lubricating oil composition of the present invention may contain a mixture of one or more amine antioxidants and one or more phenolic antioxidants.
In a preferred embodiment, the lubricating oil composition may contain a single zinc dithiophosphate or a combination of two or more zinc dithiophosphates as an antiwear agent. The zinc dithiophosphate is selected from zinc dialkyl-, diaryl- or alkylaryl-dithiophosphates.

Zinc dithiophosphate is an additive well known in the art and has the general formula II:

Can be expressed conveniently. In the formula, R ^{2 to} R ⁵ may be the same or different and are each a primary alkyl group having 1 to 20 carbon atoms, preferably 3 to 12 carbon atoms; 3 to 20 carbon atoms, preferably 3 to 3 carbon atoms. 12 secondary alkyl groups; an aryl group; or an aryl group substituted with an alkyl group having 1 to 20, preferably 3 to 18 carbon atoms.

Zinc dithiophosphate compounds in which R ^{2 to} R ⁵ are all different from each other can be used alone or in a mixture with a zinc dithiophosphate compound in which R ^{2 to} R ⁵ are all the same.

  The zinc dithiophosphate compound used in the present invention is preferably zinc dialkyldithiophosphate. Suitable commercially available zinc dithiophosphates are those obtained from Lubrizol Corporation under the trade names “Lz 1097” and “Lz 1395”, from Chevon Oronite under the trade names “OLOA 267” and “OLOA 269R”, and Afton Chemical Obtained under the trade name "HITC 7197" from Lubrizol Corporation, obtained under the trade names "Lz 677A", "Lz 1095" and "Lz 1371", obtained from Chevon Oronite under the trade name "OLOA 262", Examples thereof include those obtained under the trade name “HITC 7169” from Afton Chemical, those obtained under the trade names “Lz 1370” and “Lz 1373” from Lubrizol Corporation, and those obtained from Chevon Oronite under the trade name “OLOA 260”.

The lubricating oil composition of the present invention contains zinc dithiophosphate generally in the range of 0.4 to 1.0% by weight relative to the total weight of the lubricating oil composition.
Additional or alternative antiwear agents can be conveniently used in the lubricating oil composition of the present invention.
Typical detergents that can be used in the lubricating oil composition of the present invention include one or more salicylate detergents and / or phenolate detergents and / or sulfonate detergents.

However, in a preferred embodiment of the present invention, the amount of such additives is minimal because the metal organic and inorganic base salts used as cleaning agents can contribute to the sulfated ash content of the lubricating oil composition. It becomes.
In addition, salicylate detergents are preferred to maintain low sulfur levels.
Thus, in a preferred embodiment, the lubricating oil composition of the present invention may contain one or more salicylate detergents.

  The total content of sulfated ash in the lubricating oil composition of the present invention is preferably 1.0% by weight or less, more preferably 0.75% by weight or less, and most preferably 0.8% by weight based on the total weight of the lubricating oil composition. To maintain a level of 7 wt% or less, the detergent is preferably 0.05 to 12.5 wt%, more preferably 1.0 to 9.0 wt%, based on the total weight of the lubricating oil composition. Most preferably, it is used in an amount ranging from 2.0 to 5.0% by weight.

  In addition, the detergent was independently measured according to ISO 3771, 10-500 mg. KOH / g, more preferably 30 to 350 mg. KOH / g, most preferably 50-300 mg. It preferably has a TBN (total base number) value in the range of KOH / g.

  Furthermore, the lubricating oil composition of the present invention may contain an ashless dispersant added and mixed preferably in an amount in the range of 5 to 15% by weight with respect to the total weight of the lubricating oil composition. Examples of ashless dispersants that can be used include Japanese Patent No. And polyalkenyl succinimides and polyalkenyl succinates disclosed in US Pat. Nos. 1,367,796, 1,667,140, 1,130,811, and 1,743,435. A preferred dispersant is borated succinimide.

  Viscosity index improvers that can be conveniently used in the lubricating oil composition of the present invention include styrene-butadiene copolymers, styrene-isoprene star copolymers, and polymethacrylate copolymers and ethylene-propylene copolymers. It is done. Such viscosity index improvers can be conveniently used in amounts ranging from 1 to 20% by weight relative to the total weight of the lubricating oil composition.

Polymethacrylate can be conveniently used as an effective pour point depressant in the lubricating oil composition of the present invention.
In addition, compounds such as alkenyl succinic acid or its ester moiety, benzotriazole-based compounds and thiodiazole-based compounds can be conveniently used as corrosion inhibitors in the lubricating oil compositions of the present invention.
Compounds such as polysiloxanes, dimethylpolycyclohexane and polyacrylates can be conveniently used as antifoaming agents in the lubricating oil compositions of the present invention.

Examples of compounds that can be conveniently used in the lubricating oil composition of the present invention as seal fixatives or seal compatibilizers include commercially available aromatic esters.
The lubricating oil composition of the present invention comprises an oleylamide, one or more ether compounds, and optionally one or more nitrile compounds and / or further additives such as those previously described which are usually present in the lubricating oil composition. Can be conveniently prepared by mixing with mineral and / or synthetic base oils.

In another embodiment of the present invention, there is provided a method for lubricating an internal combustion engine, wherein the lubricating oil composition as described above is applied to the internal combustion engine.
The present invention further provides a method of using a combination of oleylamide, one or more ether compounds, and optionally one or more nitrile compounds in a lubricating oil composition to improve fuel economy and / or friction reduction. provide.
The invention will now be described with reference to the following examples, which are not intended to limit the scope of the invention in any way.

Formulations Table 1 shows the formulations tested.
The formulations in Table 1 include conventional detergents, dispersants, pour point depressants, antioxidants, viscosity improvers, and zinc dithiophosphate additives, which are present as additive packages in the diluent oil.

The base oils used in these formulations were poly α-olefin base oils (PAO-4 obtained from BP Amoco under the trade name “DURASYN 164” and PAO-5 obtained from Chevron Oronite under the trade name “SYNFLUID 5”). And a base oil obtained from Unigema under the trade name “PRIOLUBE 1976”.
The ether used is glycerin oleyl ether obtained from Asahi Denka Kogyo Co. Ltd. under the trade name “ADEKA FM-618C”.

The oleylamide used was obtained from Unigema under the trade name “UNISLIP 1757”.
The glycerol monooleate used was obtained from Oleon Chemicals under the trade name “RADIASURF 7149”.
The C12 nitrile used was obtained from Akzo Nobel under the trade name “ARNEEL 12”.
All formulations listed in Table 1 are SAE 0W20 viscosity grade oils.
The formulation was prepared by blending all ingredients at a temperature of 70 ° C. according to a one-stage blending process. The heating was mixed using a paddle type stirrer while maintaining a minimum of 30 minutes to ensure sufficient mixing.

¹ : TBN is 165 mg. KOH / g and 280 mg. Conventional additive packaging including KOH / g calcium salicylate detergent, dispersant, pour point depressant, amine and phenolic antioxidant, viscosity improver, zinc dithiophosphate additive and diluent oil.

Small traction machine (MTM) test
Friction was measured with a small traction machine manufactured by PCS equipment.
The MTM test is the “A screener test for the fuel economy potential of engine lubricants by RI Taylor, E. Nagatomi, NR Horswill, DM James, submitted at the 13th International Colloquium in January 2002 Tribology. "Scriner test for fuel economic potential)".

The coefficient of friction was measured with a small traction machine using a “ball on disk” structure.
The ball specimen is a ground steel ball bearing with a diameter of 19.05 mm. The disc specimen is a polished bearing steel disc having a diameter of 46 mm and a thickness of 6 mm.

The ball specimen was fixed concentrically on the motor drive shaft. The disc specimen was fixed concentrically on the other motor drive shaft. In order to create a point contact area with minimal spin and skew components, a ball was loaded onto the disc. At the contact point, the surface speed of the ball and disk was adjusted to maintain a slide to roll ratio of 100%.
The test was conducted at variable temperature and variable average surface velocity under a pressure of 1.25 GPa (71 N load) or 0.82 GPa (20 N load) as detailed in the results table below.

Results and Discussion The above tests were conducted on the formulations shown in Table 1. The obtained results are described in detail below.
Test under high load / high temperature conditions The formulations of Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to high load (1.25 GPa) and high temperature (105 ° C, 125 ° C) conditions and various speeds (1000 mm / s, MTM tests were conducted at 500 mm / s, 100 mm / s, and 50 mm / s).
The coefficient of friction was measured and is shown in Table 2.

  Table 3 shows the average coefficient of friction measured for the formulation of Comparative Example 1 in relation to intermediate speeds (ie, 1000 mm / s, 500 mm / s, 100 mm / s, 50 mm / s) under high load test conditions. For comparison, the average friction reduction rate (%) of the blends of Examples 1 and 2 and Comparative Examples 2 and 3 will be described in detail.

  In Table 3, positive values indicate improved friction reduction (ie, low coefficient of friction) compared to the average coefficient of friction measured for the formulation of Comparative Example 1, and negative values are those of Comparative Example 1. Compared to the average coefficient of friction measured for the formulation, it shows a worsening friction drop (ie, a high coefficient of friction).

² : Relative average coefficient of friction measured for the formulation of Comparative Example 1.

  In Table 4, Examples 1, 2 and Comparative Example 2, compared to the average coefficient of friction measured for the formulation of Comparative Example 1 at high temperatures (ie, 125 ° C. and 105 ° C.) under high load test conditions. The average friction reduction rate (%) of the blend of 3 is described in detail.

  In Table 4, positive values indicate improved friction reduction (ie, low coefficient of friction) compared to the average coefficient of friction measured for the formulation of Comparative Example 1, and negative values are of Comparative Example 1. Compared to the average coefficient of friction measured for the formulation, it shows a worsening friction drop (ie, a high coefficient of friction).

³ : Relative average coefficient of friction measured for the formulation of Comparative Example 1.

As is apparent from Tables 3 and 4, the oleylamide / ether combinations of Examples 1 and 2 show a synergistic friction reduction.
The improvement in ether friction reduction upon addition of oleylamide ranges from 3 to 7% depending on the conditions of use.
The results of Table 4 are shown graphically in FIG. As is clear from FIG. 1, it is expected from the results of Comparative Examples 2 and 3 that when oleylamide is used in combination with ether, the friction reduction is expected to be worse than that of Comparative Example 2. When such a combination is used, not only the friction reduction performance is not unexpectedly deteriorated, but the friction reduction performance is further improved by using such a combination.

Test under Low Load / Low Temperature Conditions For the blends of Examples 1, 3 and Comparative Examples 1, 4, low load (0.82 GPa) and low temperature (105 ° C., 70 ° C., 45 ° C.) conditions and various speeds (500 mm) / TM, 100 mm / s, 50 mm / s, 10 mm / s).
The coefficient of friction was measured and is shown in Table 5.

  Table 6 compares the formulation of Comparative Example 1 with the average coefficient of friction measured at low speeds (ie, 500 mm / s, 100 mm / s, 50 mm / s and 10 mm / s) under low load test conditions. The average friction reduction rate (%) of the formulations of Examples 1 and 3 and Comparative Example 4 will be described in detail.

  In Table 6, positive values indicate improved friction reduction (ie, low coefficient of friction) compared to the average coefficient of friction measured for the formulation of Comparative Example 1, and negative values are of Comparative Example 1. Compared to the average coefficient of friction measured for the formulation, it shows a worsening friction drop (ie, a high coefficient of friction).

⁴ : Relative average coefficient of friction measured for the formulation of Comparative Example 1.

  Table 7 compares Examples 1, 3 and Comparative Example 1 with the average coefficient of friction measured at low temperatures (ie, 105 ° C., 70 ° C., 45 ° C.) under low load test conditions. The average friction reduction (%) of the formulation of Example 4 is detailed.

  In Table 6, positive values indicate improved friction reduction (ie, low coefficient of friction) compared to the average coefficient of friction measured for the formulation of Comparative Example 1, and negative values are of Comparative Example 1. Compared to the average coefficient of friction measured for the formulation, it shows a worsening friction drop (ie, a high coefficient of friction).

⁵ : Relative average coefficient of friction measured for the formulation of Comparative Example 1.
As is apparent from Tables 6 and 7, the oleylamide / ether / nitrile combination of Example 3 exhibits a synergistic friction reduction under low load conditions.

About the compound of Examples 1, 2 and Comparative Examples 2, 3, the relative friction fall by the MTM (small traction machine) test measured at high temperature under high load conditions is shown with a graph.

Claims (10)

  A lubricating oil composition comprising a base oil, oleylamide and one or more ether compounds.   The lubricating oil composition according to claim 1, wherein the one or more ether compounds are acyclic ethers. One or more ether compounds are of formula I:

(However, R ¹ , R ² and R ³ are each independently selected from an alkyl group having 10 to 30 carbon atoms, an unsaturated hydrocarbon group having 10 to 30 carbon atoms, and hydrogen)
The lubricating oil composition according to claim 1, which is a compound of   The one or more ether compounds are selected from glycerin oleyl monoether, glycerin oleyl diether, glycerin oleyl triether, glycerin stearyl monoether, glycerin stearyl diether, and glyceryl stearyl triether. The lubricating oil composition described in 1.   The lubricating oil composition according to any one of claims 1 to 4, wherein the one or more ether compounds are present in a range of 0.1 to 5% by weight relative to the total weight of the lubricating oil composition.   The lubricating oil composition according to any one of claims 1 to 4, wherein the oleylamide is present in a range of 0.05 to 0.5% by weight relative to the total weight of the lubricating oil composition.   The lubricating oil composition according to any one of claims 1 to 6, wherein the composition further contains one or more nitrile compounds.   The lubricating oil composition according to claim 7, wherein the nitrile compound is present in the range of 0.1 to 0.8% by weight relative to the total weight of the lubricating oil composition.   The lubricating oil composition according to claim 7 or 8, wherein the one or more nitrile compounds are selected from coconut oil fatty acid nitrile, oleyl nitrile, decane nitrile, and beef tallow nitrile. A lubricating oil composition according to any one of claims 1 to 9, wherein the lubricating oil composition is applied to an internal combustion engine.