JP2011140643A - Lubricating oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil composition, especially obtained by using a base oil having a high purification degree, having good rust-preventing properties, low sludge and also excellent energy saving characteristics through having a low friction coefficient, and usable as the whole industrial lubricating oils, in particular for machine oils, hydraulic oils, turbine oils, compressor oils, gear oils and bearing oils. <P>SOLUTION: The lubricating oil composition contains a succinic acid derivative and an epoxy compound as additives in a base oil of a mineral oil and a synthetic oil, having a small sulfur content and high purification degree. As a result, the lubricating oil composition having the excellent rust-preventing properties and low sludge, and suitable as the industrial lubricating oils can be provided. Preferably, the lubricating oil composition having the reduced friction coefficient and rich energy-saving properties can be obtained by adding at least one of an amine compound, an amide compound and an ester of a polyhydric alcohol besides them. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lubricating oil composition, and relates generally to industrial lubricating oil using a refined base oil having a low sulfur content. The present invention relates to a lubricating oil composition used as a bearing oil.

Lubricating oil compositions, especially industrial lubricating oil compositions, are required to have good rust prevention and friction properties, and have a low coefficient of friction (μ), which effectively reduces friction loss in machinery and equipment. However, it is required to achieve high energy saving.
For example, hydraulic equipment is frequently used in construction machinery, etc., but if the friction coefficient of lubricating oil used as hydraulic fluid is high, a micro stick-slip phenomenon occurs in the sliding part of the reciprocating packing of the hydraulic cylinder. In addition, the cylinder chattering, vibration, squealing, abnormal noise generation, and the like occur, and the hydraulic device cannot be controlled with high precision (Patent Document 1). Therefore, in order for the hydraulic cylinder to move accurately and smoothly, it is necessary to reduce the friction coefficient of the lubricating oil.

  In order to maintain the performance of the lubricating oil used in machinery and equipment, rust prevention is essential. This is because the temperature of the lubricating oil in the tank of the mechanical device fluctuates depending on the use conditions, so that condensed water may be mixed in the lubricating oil in the tank, and water is mixed in due to water leakage from the cooling water piping. This is due to the fact that

Japanese Patent Laid-Open No. 9-111277

  The present invention seeks to obtain an industrial oil lubricant having a high energy-saving property by reducing the friction coefficient exhibited by the lubricant. In addition, when such a lubricating oil composition is used as a hydraulic fluid in a hydraulic device, the hydraulic device can be controlled with high accuracy without causing phenomena such as chatter, vibration, squeal, abnormal noise, etc. of the hydraulic cylinder. At the same time, it is intended to suppress the generation of rust and to give good rust prevention properties. Thus, it is an object of the present invention to obtain a lubricating oil composition having good rust prevention properties and high energy efficiency and high operating efficiency.

The present invention relates to industrial applications such as hydraulic fluids by adding a succinic acid derivative and an epoxy compound as additives to a refined mineral oil and / or synthetic oil base oil having a sulfur content of 0.3% by mass or less. A lubricating oil composition suitable as a lubricating oil composition can be obtained.
Further, by adding at least one of an amine compound, an amide compound, and a polyhydric alcohol ester as an additive, a lubricating oil composition that is further rich in rust prevention and excellent in energy saving can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the sludge generate | occur | produced with various industrial apparatuses can be decreased, generation | occurrence | production of rust can be suppressed, and the lubricating oil composition rich in rust prevention property can be obtained. Furthermore, friction loss can be effectively reduced, and energy saving can be achieved. Further, when used as a hydraulic fluid, by reducing the friction coefficient, it is possible to accurately control the hydraulic device without causing phenomena such as chatter, vibration, squealing, and abnormal noise generation of the hydraulic cylinder.

  As the base oil of the present lubricating oil composition, a highly refined oil that is a mineral oil or synthetic oil used in ordinary lubricating oil and has a sulfur content of about 0.3% by mass or less can be used. Base oils belonging to 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 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, which is suitable for the present invention. The viscosity of these base oils is not particularly limited, but the viscosity index is 90 to 125, preferably 100 to 120. The kinematic viscosity at 40 ° C. is preferably ² to 680 mm ² / s, more preferably 8 to 220 mm ² / s. The total sulfur content is less than 700 ppm, preferably less than 500 ppm, more preferably less than 10 ppm. The total nitrogen content is also less than 10 ppm, preferably less than 1 ppm. Furthermore, the aniline point should be 80 to 150 ° C, preferably 100 to 135 ° C.

Group 3 base oil and Group 2 plus base oil include, for example, a paraffinic mineral oil produced by advanced hydrorefining and a dewaxing process for a lubricating oil fraction obtained by atmospheric distillation of crude oil. A base oil refined by the ISODEWAX process for converting and dewaxing the produced wax to isoparaffin, and a base oil refined by the mobile WAX isomerization process are also suitable. The viscosity of these base oils is not particularly limited, but the viscosity index is 95 to 145, preferably 100 to 140. The kinematic viscosity at 40 ° C. is preferably ² to 680 mm ² / s, more preferably 8 to 220 mm ² / s. The total sulfur content is 0 to 100 ppm, preferably less than 10 ppm. The total nitrogen content is also less than 10 ppm, preferably less than 1 ppm. Furthermore, it is good to use an aniline point of 80-150 degreeC, Preferably it is 110-135 degreeC.

  Examples of the synthetic oil include polyolefin, alkylbenzene, alkylnaphthalene, ester, polyoxyalkylene glycol, polyphenyl ether, dialkyldiphenyl ether, fluorine-containing compounds (perfluoropolyether, fluorinated polyolefin, etc.), silicone oil and the like.

The polyolefin includes polymers of various olefins or hydrides thereof. Any olefin may be used, and examples thereof include ethylene, propylene, butene, and α-olefins 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 40 ° C. is preferably ² to 680 mm ² / s, more preferably 8 to 220 mm ² / s.

GTL (Gas Liquid) synthesized by the Fischer-Tropsch method, which is a natural gas liquid fuel technology, has an extremely low sulfur content and aromatic content compared to mineral oil base oil refined from crude oil. Is extremely high, so that it has excellent oxidation stability and very low evaporation loss, and is therefore suitable as the base oil of the present invention. The viscosity property of the GTL base oil is not particularly limited, but usually the viscosity index is 130 to 180, more preferably 140 to 175. Moreover, kinematic viscosity in 40 degreeC is 2-680 mm < ² > / s, More preferably, it is 5-120 mm < ² > / s. In general, the total sulfur content is less than 10 ppm and the total nitrogen content is less than 1 ppm. An example of such a GTL base oil product is SHELL XHVI®.

The sulfur content in the base oil component of the lubricating oil composition of the present invention is 0.3% by mass or less, preferably 1000 ppm or less, more preferably 100 ppm or less, and even more preferably 10 ppm or less.
The content of the base oil in the lubricating oil composition is not particularly limited, but is 60% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% based on the total amount of the lubricating oil composition. It is at least mass%.

The succinic acid derivative is represented by the general formula (1).

In the general formula (1), X ₁ and X ₂ are each hydrogen or 3 to 6 identical or different alkyl group, alkenyl group or hydroxyalkyl group, preferably a hydrogen atom, 1-hydroxypropyl group, 2 -A hydroxypropyl group, a 2-methylpropyl group, and a tertiary butyl group are preferable. X ₃ is an alkyl group or alkenyl group having 1 to 30 carbon atoms, an alkyl group having an ether bond, or a hydroxyalkyl group. For example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, dodecylene, tridecyl, tetradecyl group, tetradecylene, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecylene, eicosyl group, docosyl group, an alkoxycarbonyl propyl, _{3- (C} 6 ~C ₁₈₎ hydrocarbonoxy _(C 3 _{~C 6)} alkyl Group, more preferably tetraisopropyl group, oleyl group, cyclohexyloxypropyl group, 3-octyloxypropyl group, 3-isooctyloxypropyl group, 3-decyloxypropyl group, 3-isodecyloxypropyl group, 3- _(C 12 ~C ₁₆₎ Arco Shipuropiru group is good. Aminated products of these compounds may also be used.

  The succinic acid derivative has an acid value defined by JIS K2501 of 10 to 300 mgKOH / g, preferably 30 to 200 mgKOH / g. The succinic acid derivative in the lubricating oil composition is about 0.001 to 0.5% by mass, preferably about 0.001 to 0.1% by mass, and more preferably about 0.005 to 0.1% by mass. Used in degree. This succinic acid derivative can be used alone or in combination.

Examples of the epoxy compound include an aliphatic epoxy compound, and an epoxy compound represented by the following general formula (2).

In the general formula (2), R ₁ is hydrogen (H) or a linear or branched alkyl group or alkenyl group having 1 to 22 carbon atoms. R ₂ represents hydrogen (H), a linear or branched alkyl group or alkenyl group having 1 to 22 carbon atoms, a “—R ₃ —COOH” group, a “—R ₃ —COOR ₄ ” group, or a “—OH” group. (Wherein R ₃ is a linear or branched alkylene group or alkenylene group having 1 to 22 carbon atoms, and R ₄ is a linear or branched alkyl group or alkenyl group having 1 to 22 carbon atoms).

  Examples of the epoxy compound represented by the general formula (2) include what is called olefin oxide as an epoxidized alkenyl compound. For example, octene oxide, nonene oxide, decene oxide, undecene oxide, dodecene oxide, tridecene oxide, tetradecene oxide, pentadecene oxide, hexadecene oxide, heptadecene oxide, octadecene oxide, and terminally epoxidized alpha Examples include decene oxide, alpha dodecene oxide, alpha tetradecene oxide, alpha hexadecene oxide, and alpha octadecene oxide.

  Other epoxy compounds were produced by epoxidizing rapeseed oil, soybean oil, linseed oil, castor oil, palm oil, palm oil, palm kernel oil, sunflower oil, rice bran oil, safflower oil, beef tallow, lard, etc. And epoxidized fatty acid glycerides such as epoxidized rapeseed oil, epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil, and epoxidized safflower oil.

  Epoxy compounds other than the above-mentioned epoxy compounds include epoxidized ester compounds such as rapeseed oil, soybean oil, linseed oil, castor oil, coconut oil, palm oil, palm kernel oil, sunflower oil, rice bran oil, safflower oil, and beef tallow. , Epoxidized rapeseed oil ester, epoxidized soybean oil ester, epoxidized linseed oil ester, epoxidized castor oil ester, epoxidized safflower oil ester Etc.

  Further, the alcohol residue of these esters is an alkyl group, an alkyl group having an ether bond, or a hydroxyalkyl group, and more preferably a butyl group, an isobutyl group, or a 2-ethylhexyl group. Examples include epoxidized methyl stearate, epoxidized butyl stearate, epoxidized octyl stearate, epoxidized rapeseed fatty acid isobutyl ester, epoxidized rapeseed fatty acid 2-ethylhexyl ester, epoxidized linseed oil fatty acid butyl ester and the like. The main components of common rapeseed fatty acids are fatty acids having 18 carbon atoms, 63% oleic acid, 20% linoleic acid, and 8% linolenic acid. The main components of linseed fatty acids are 21% oleic acid and 13% linoleic acid. , A fatty acid having 18 carbon atoms and 57% linolenic acid.

  These epoxy compounds are known as plasticizers and stabilizers for rubbers and plastics. The compounding amount of the epoxy compound in the lubricating oil composition is 0.01 to 5% by mass, more preferably 0.01 to 2 mass%, More preferably, 0.01-1 mass% is good.

Examples of amine compounds include aliphatic amines, and alkylamines represented by the following general formula (3).
(Chemical formula 3)
(R ₅ ) _n NH _3-n (3)

(In Formula 3, R ₅ is a straight-chain saturated or unsaturated alkyl group having 6 to 30 carbon atoms, and n is an integer of 1 or 2.)

Among the alkylamines represented by the general formula (3), the primary amines include those represented by the following general formula (4).
(Chemical formula 4)
_{H 2 N-X 5 (4} )

In the general formula (4), _{X 5} is an alkyl or alkenyl group having 1 to 30 carbon atoms. Examples of such compounds include laurylamine, coconutamine, n-tridecylamine, myristylamine, n-pentadecylamine, n-palmitylamine, n-heptadecylamine, n-stearylamine, isostearylamine, n -Nonadecylamine, n-eicosylamine, n-heneicosylamine, n-docosylamine, n-tricosylamine, n-pentacosylamine, oleylamine, beef tallow amine, hydrogenated tallow amine, soybean amine and the like. The number of carbon atoms of X ₅ is preferably 8 to 24, and more preferably 12 to 18. X ₅ may be linear aliphatic, branched aliphatic, or tertiary alkyl group.

  Secondary amines include, for example, dilaurylamine, dicoconutamine, di-n-tridecylamine, di-n-myristylamine, di-n-pentadecylamine, di-n-palmitylamine, di-n- Heptadecylamine, di-n-stearylamine, diisostearylamine, di-n-nonadecylamine, di-n-eicosylamine, di-n-heneicosylamine, di-n-docosylamine, di-n-tricosylamine, di-n-pentacosi Luamine, dioleylamine, di beef tallow amine, dihydrogenated beef tallow amine, di soy amine and the like.

Examples of the aliphatic amine include diamines represented by the following general formula (5).
(Chemical formula 5)
_{X 6 -HN-X 7 -NH 2} (5)

In the general formula (5), _{X 6} is an alkyl or alkenyl group having 1 to 30 carbon atoms. X ₆ preferably has 8 to 24 carbon atoms, more preferably 12 to 18 carbon atoms. X ₇ is an alkylene group having 1 to 12 carbon atoms. X ₇ preferably has 1 to 8 carbon atoms, more preferably 2 to 4 carbon atoms.

  Examples of the diamine compound represented by the general formula (5) include N-octyl-1,2-ethylenediamine, N-nonyl-1,2-ethylenediamine, N-decyl-1,2-ethylenediamine, N-undecyl-1, 2-ethylenediamine, N-lauryl-1,2-ethylenediamine, N-tridecyl-1,2-ethylenediamine, N-myristyl-1,2-ethylenediamine, N-tetradecyl-1,2-ethylenediamine, N-pentadecyl-1, 2-ethylenediamine, N-palmityl-1,2-ethylenediamine, N-heptadecyl-1,2-ethylenediamine, N-oleyl-1,2-ethylenediamine, N-stearyl-1,2-ethylenediamine, N-isostearyl-1 , 2-Ethylenediamine, N-nonadecyl-1,2-ethyl Diamine, N-eicosyl-1,2-ethylenediamine, N-coconut-1,2-ethylenediamine, N-beef tallow-1,2-ethylenediamine, N-hydrogenated tallow-1,2-ethylenediamine, N-soy-1, There are ethylenediamines such as 2-ethylenediamine.

  N-octyl-1,3-propylenediamine, N-nonyl-1,3-propylenediamine, N-decyl-1,3-propylenediamine, N-undecyl-1,3-propylenediamine, N-lauryl- 1,3-propylenediamine, N-tridecyl-1,3-propylenediamine, N-myristyl-1,3-propylenediamine, N-tetradecyl-1,3-propylenediamine, N-pentadecyl-1,3-propylenediamine N-palmityl-1,3-propylenediamine, N-heptadecyl-1,3-propylenediamine, N-oleyl-1,3-propylenediamine, N-stearyl-1,3-propylenediamine, N-isostearyl- 1,3-propylenediamine, N-nonadecyl-1,3-propylenediamine, N- Icosyl-1,3-propylenediamine, N-coconut-1,3-propylenediamine, N-tallow-1,3-propylenediamine, N-hydrogenated tallow-1,3-propylenediamine, N-soy-1, There are propylenediamines such as 3-propylenediamine.

  Further, N-octyl-1,4-butylenediamine, N-nonyl-1,4-butylenediamine, N-decyl-1,4-butylenediamine, N-undecyl-1,4-butylenediamine, N-lauryl- 1,4-butylenediamine, N-tridecyl-1,4-butylenediamine, N-myristyl-1,4-butylenediamine, N-tetradecyl-1,4-butylenediamine, N-pentadecyl-1,4-butylenediamine N-palmityl-1,4-butylenediamine, N-heptadecyl-1,4-butylenediamine, N-oleyl-1,4-butylenediamine, N-stearyl-1,4-butylenediamine, N-isostearyl- 1,4-butylenediamine, N-nonadecyl-1,4-butylenediamine, N-eicosyl-1,4-butylene Min, N-coconut-1,4-butylenediamine, N-tallow-1,4-butylenediamine, N-hydrogenated tallow-1,4-butylenediamine, N-soybean-1,4-butylenediamine, etc. There are butylenediamines.

Examples of the aliphatic amine include amines represented by the following general formula (6).
(Chemical formula 6)
_{X 8 -N- (X 9) 2} (6)

In the general formula (6), X ₈ is an alkyl group or alkenyl group having 1 to 30 carbon atoms, and X ₈ preferably has 1 to 20 carbon atoms, more preferably 1 to 8 or 12 to 18 carbon atoms. . X ₉ is an alkyl group having 1 to 20 carbon atoms, an alkenyl group, or a hydroxyalkyl group, and X ₉ preferably has 1 to 8 or 12 to 18 carbon atoms.

X ₈ is a methyl group, for example, dioctylmethylamine, dinonylmethylamine, didecylmethylamine, diundecylmethylamine, dilaurylmethylamine, ditridecylmethylamine, dimyristylmethylamine, ditetradecylmethyl Amine, Dipentadecylmethylamine, Dipalmitylmethylamine, Diheptadecylmethylamine, Dioleylmethylamine, Distearylmethylamine, Diisostearylmethylamine, Dinonadecylmethylamine, Diaicosylmethylamine, Dicoco There are dialkylmethylamines such as nutmethylamine, di-tallow methylamine, dihydrogenated tallow methylamine, and di-soy methylamine.

Examples of X ₉ being a methyl group include octyldimethylamine, nonyldimethylamine, decyldimethylamine, undecyldimethylamine, lauryldimethylamine, tridecyldimethylamine, myristyldimethylamine, tetradecyldimethylamine, pentadecyl. Dimethylamine, palmityldimethylamine, heptadecyldimethylamine, oleyldimethylamine, stearyldimethylamine, isostearyldimethylamine, nonadecyldimethylamine, eicosyldimethylamine, coconut dimethylamine, beef tallow dimethylamine, hydrogenated tallow dimethylamine And alkyl dimethylamines such as soybean dimethylamine.

Further, as X ₉ being a hydroxyalkyl group, for example, N-octyldiethanolamine, N-nonyldiethanolamine, N-decyldiethanolamine, N-undecyldiethanolamine, N-lauryldiethanolamine, N-tridecyldiethanolamine, N-myristyldiethanolamine N-tetradecyldiethanolamine, N-pentadecyldiethanolamine, N-palmityldiethanolamine, N-heptadecyldiethanolamine, N-oleyldiethanolamine, N-stearyldiethanolamine, N-isostearyldiethanolamine, N-nonadecyldiethanolamine, N-eico Sildiethanolamine, N-coconut diethanolamine, N-tallow diethanolamine, N-water N-alkyldiethanolamines such as raw beef tallow diethanolamine, N-soybean diethanolamine, N-octyldipropanolamine, N-nonyldipropanolamine, N-decyldipropanolamine, N-undecyldipropanolamine, N-lauryl Dipropanolamine, N-tridecyldipropanolamine, N-myristyldipropanolamine, N-tetradecyldipropanolamine, N-pentadecyldipropanolamine, N-palmityldipropanolamine, N-heptadecyldipropanolamine N-oleyl dipropanolamine, N-stearyl dipropanolamine, N-isostearyl dipropanolamine, N-nonadecyl dipropanolamine, N-eicosyl dipropanolamine N- coconut dipropanolamine, N- tallow dipropanolamine, N- hydrogenated tallow di-propanolamine, there are N- alkyl dipropanolamine such as N- soybean dipropanolamine.

  These aliphatic amines may be used in the lubricating oil composition in an amount of about 0.005 to 5% by mass, preferably about 0.01 to 1% by mass, selected from the above group.

Examples of the amide compound in the present invention include an amide compound that is a product of a fatty acid and a monoamine represented by the general formula (7), or an amide compound that is a product of a fatty acid and a polyamine.
(Chemical formula 7)
X ₁₀ CONH ₂ (7)

As an amide compound composed of a fatty acid and a monoamine, in the general formula (7), X ₁₀ is an alkyl group or alkenyl group having 1 to 30 carbon atoms. For example, laurylamide, coconutamide, n-tridecylamide, myristylamide, n-pentadecylamide, n-palmitylamide, n-heptadecylamide, n-stearylamide, isostearylamide, n-nonadecylamide, n -Eicosylamide, n-heneicosylamide, n-docosylamide, n-tricosylamide, n-pentacosylamide, oleylamide, beef tallow amide, hydrogenated tallow amide, soybean amide and the like. Preferably the number of carbon atoms of X ₁₀ is 8 to 24, and more preferably 12 to 18. The alkyl group or alkenyl group may be a linear aliphatic, branched aliphatic, or tertiary alkyl group.

  Examples of amide compounds of polyamines and fatty acids include, for example, isostearic acid triethylenetetramide, isostearic acid tetraethylenepentamide, oleic acid diethylenetriamide, oleic acid diethanolamide, and the like, saturated or unsaturated fatty acids having 1 to 24 carbon atoms and aliphatic Reaction products with amide, polyalkylene polyamide and the like can be mentioned.

  The amide compound in the lubricating oil composition is about 0.001 to 0.5% by mass, preferably about 0.001 to 0.1% by mass, more preferably about 0.005 to 0.1% by mass. Used in These amide compounds can be used alone or in combination.

  An ester of a polyhydric alcohol can be blended with the lubricating oil composition of the present invention. As the ester of this polyhydric alcohol, those conventionally used as oily agents, for example, glycerol, sorbitol, alkylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, xylitol and the like have 1 to 1 carbon atoms. 24 partial or complete esters of saturated or unsaturated fatty acids can be used.

  As such, specifically, for example, as glycerol ester, glycerol monolaurate, glycerol monostearate, glycerol monoisostearate, glycerol monopalmitate, glycerol monooleate, glycerol dilaurate, glycerol distearate, Examples include glycerol diisostearate, glycerol dipalmitate, and glycerol diolate.

  The sorbitol esters include sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monooleate, sorbitol dilaurate, sorbitol dipalmitate, sorbitol distearate, sorbitol diolate, sorbitol tristearate, sorbitol tris Examples thereof include laurylate, sorbitol trioleate, sorbitol sesquioleate, and sorbitol tetraoleate.

  Examples of alkylene glycol esters include ethylene glycol monolaurate, ethylene glycol monostearate, ethylene glycol monooleate, ethylene glycol dilaurate, ethylene glycol distearate, ethylene glycol diolate, propylene glycol monolaurate, propylene glycol monostearate. Rate, propylene glycol monooleate, propylene glycol dilaurate, propylene glycol distearate, propylene glycol dioleate and the like.

  Examples of neopentyl glycol esters include neopentyl glycol monolaurate, neopentyl glycol monostearate, neopentyl glycol monooleate, neopentyl glycol dilaurate, neopentyl glycol distearate, neopentyl glycol dioleate, and the like. .

  Examples of the trimethylolpropane ester include trimethylolpropane monolaurate, trimethylolpropane monostearate, trimethylolpropane monooleate, trimethylolpropane dilaurate, trimethylolpropane distearate, and trimethylolpropanediolate.

Examples of the pentaerythritol ester include pentaerythritol monolaurate, pentaerythritol monostearate, pentaerythritol monooleate, pentaerythritol dilaurate, pentaerythritol distearate, pentaerythritol dioleate, dipentaerythritol monooleate, and the like.
As such a fatty acid ester of a polyhydric alcohol, a partial ester of a polyhydric alcohol and an unsaturated fatty acid is preferably used.

  The fatty acid ester of these polyhydric alcohols is used in the lubricating oil composition at about 0.01 to 5% by mass, preferably about 0.05 to 2% by mass. If the amount used is outside the above range, the effect of reducing the friction coefficient may be weakened.

  In addition to the above-described components, various additives can be appropriately used as necessary in order to further improve the performance. These include antioxidants, metal deactivators, extreme pressure agents, oiliness improvers, antifoaming agents, viscosity index improvers, pour point depressants, cleaning dispersants, rust inhibitors, demulsifiers, etc. Other known lubricating oil additives can be mentioned.

  As antioxidant used in this invention, what is used for lubricating oil is practically preferable, and a phenolic antioxidant, an amine antioxidant, and a sulfur type antioxidant can be mentioned. These antioxidants can be used alone or in combination in the lubricating oil composition in the range of about 0.01 to 5% by mass.

  Examples of the amine antioxidant include p, p′-dioctyl-diphenylamine (Seiko Chemical Co., Ltd .: Nonflex OD-3), p, p′-di-α-methylbenzyl-diphenylamine, and Np-butylphenyl. Dialkyl-diphenylamines such as -Np'-octylphenylamine, monoalkyldiphenylamines such as mono-t-butyldiphenylamine and monooctyldiphenylamine, di (2,4-diethylphenyl) amine, di (2-ethyl- Bis (dialkylphenyl) amines such as 4-nonylphenyl) amine, alkylphenyl-1-naphthylamines such as octylphenyl-1-naphthylamine, Nt-dodecylphenyl-1-naphthylamine, 1-naphthylamine, phenyl-1 -Naphthylamine, phenyl Aryl-naphthylamines such as 2-naphthylamine, N-hexylphenyl-2-naphthylamine, N-octylphenyl-2-naphthylamine, N, N′-diisopropyl-p-phenylenediamine, N, N′-diphenyl-p-phenylene Examples include phenylenediamines such as diamine, phenothiazines (manufactured by Hodogaya Chemical Co., Ltd .: Phenothiazine), and phenothiazines such as 3,7-dioctylphenothiazine.

  Examples of sulfur-based antioxidants include dialkyl sulfides such as didodecyl sulfide and dioctadecyl sulfide, didodecyl thiodipropionate, dioctadecyl thiodipropionate, dimyristyl thiodipropionate, and dodecyl octadecyl thiodipropionate. Examples include thiodipropionic acid esters and 2-mercaptobenzimidazole.

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-t-butyl- such as -4-alkylphenols, 2,6-di-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethoxyphenol - there is a 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 (Ciba Specialty Chemicals: Irganox L135) 3,5-di-t-butyl-4-hydroxyphenyl) propionates, 2,6-di-t-butyl-α- Methylamino-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) There are 2,2′-methylenebis (4-alkyl-6-t-butylphenol) s 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), triethyl Renglycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] (manufactured by Yoshitomi Pharmaceutical: 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), bis such as 2,2′-thiobis (4,6-di-t-butyl-resorcin) There is a phenol compound.
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.

  Examples of phosphorus antioxidants include triaryl phosphites such as triphenyl phosphite and tricresyl phosphite, trialkyl phosphites such as trioctadecyl phosphite and tridecyl phosphite, and tridodecyl trithiophosphite. It is done.

Metal deactivators that can be used in conjunction with the compositions of the present invention include 4-alkyl-benzotriazoles such as benzotriazole, 4-methyl-benzotriazole, 4-ethyl-benzotriazole, 5-methyl-benzotriazole, 5- 5-alkyl-benzotriazoles such as ethyl-benzotriazole, 1-alkyl-benzotriazoles such as 1-dioctylaminomethyl-2,3-benzotriazole, 1 such as 1-dioctylaminomethyl-2,3-toltriazole -2- (alkyldithio) such as benzotriazole derivatives such as alkyl-tolutriazoles, benzimidazole, 2- (octyldithio) -benzimidazole, 2- (decyldithio) -benzimidazole, 2- (dodecyldithio) -benzimidazole ) Benzimidazole derivatives such as 2- (alkyldithio) -toluimidazoles such as benzimidazoles, 2- (octyldithio) -toluimidazole, 2- (decyldithio) -toluimidazole, 2- (dodecyldithio) -toluimidazole, etc. is there.
Indazole derivatives such as tolindazoles such as indazole, 4-alkyl-indazole, 5-alkyl-indazole, benzothiazole, 2-mercaptobenzothiazole derivative (manufactured by Chiyoda Chemical Co., Ltd .: Thiolite B-3100), 2- (hexyl) 2- (Alkyldithio) benzothiazoles such as dithio) benzothiazole, 2- (octyldithio) benzothiazole, 2- (alkyldithio) such as 2- (hexyldithio) tolthiazole, 2- (octyldithio) tolthiazole Tolthiazoles, 2- (N, N-diethyldithiocarbamyl) benzothiazole, 2- (N, N-dibutyldithiocarbamyl) -benzothiazole, 2- (N, N-dihexyldithiocarbamyl) -benzothiazole 2- (N, N-dia Kirdithiocarbamyl) benzothiazoles, 2- (N, N-diethyldithiocarbamyl) tolthiazole, 2- (N, N-dibutyldithiocarbamyl) tolthiazole, 2- (N, N-dihexyldithiocarbamyl) ) There are benzothiazole derivatives such as 2- (N, N-dialkyldithiocarbamyl) -torzothiazoles such as tolthiazole.
Furthermore, 2- (alkyldithio) -benzoxazoles such as 2- (octyldithio) benzoxazole, 2- (decyldithio) benzoxazole, 2- (dodecyldithio) benzoxazole, 2- (octyldithio) toluoxazole, 2 Benzoxazole derivatives such as 2- (alkyldithio) toluazoles such as-(decyldithio) toluxazole and 2- (dodecyldithio) toluxazole, 2,5-bis (heptyldithio) -1,3,4-thiadiazole, 2 , 5-bis (nonyldithio) -1,3,4-thiadiazole, 2,5-bis (dodecyldithio) -1,3,4-thiadiazole, 2,5-bis (octadecyldithio) -1,3,4 2,5-bis (alkyldithio) -1,3,4-thio such as thiadiazole Diazoles, 2,5-bis (N, N-diethyldithiocarbamyl) -1,3,4-thiadiazole, 2,5-bis (N, N-dibutyldithiocarbamyl) -1,3,4-thiadiazole 2,5-bis (N, N-dialkyldithiocarbamyl) -1,3,4-thiadiazoles such as 2,5-bis (N, N-dioctyldithiocarbamyl) -1,3,4-thiadiazole 2-N, N-dibutyldithiocarbamyl-5-mercapto-1,3,4-thiadiazole, 2-N, N-dioctyldithiocarbamyl-5-mercapto-1,3,4-thiadiazole Thiadiazole derivatives such as N, N-dialkyldithiocarbamyl-5-mercapto-1,3,4-thiadiazoles, 1-di-octylaminomethyl-2,4-triazol Like 1-alkyl-2,4-triazole derivative of triazoles such like.
These metal deactivators can be used alone or in combination in the lubricating oil composition in the range of about 0.01 to 0.5 mass%.

In order to impart wear resistance and extreme pressure to the lubricating oil composition of the present invention, a phosphorus compound may be added. Examples of the phosphorus compound suitable for the present invention include phosphoric acid ester, acidic phosphoric acid ester, amine salt of acidic phosphoric acid ester, chlorinated phosphoric acid ester, phosphite ester, phosphorothionate, zinc dithiophosphate, and dithiophosphorus. Examples include esters of acids and alkanols or polyether alcohols or derivatives thereof, phosphorus-containing carboxylic acids, and phosphorus-containing carboxylic acid esters.
These phosphorus compounds can be used alone or in combination in the lubricating oil composition in the range of about 0.01 to 2% by mass.

  Examples of the phosphate ester include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl phosphate, Tetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tris (iso-propylphenyl) phosphate, triaryl phosphate, tricresyl phosphate, Trixylenyl phosphate, cresyl diphenyl phosphate, and xyl Such as sulfonyl diphenyl phosphate.

  Specific examples of the acidic phosphate ester include monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid Phosphate, monododecyl acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate, dibutyl acid Dipentyl acid phosphate Xyl acid phosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, ditetradecyl acid phosphate, dipentadecate Examples include dihexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, and dioleyl acid phosphate.

  Examples of the amine salt of the acidic phosphate ester include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. , Salts with amines such as dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, and trioctylamine It is done.

  Examples of the phosphites include dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, geode Rail phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl Examples thereof include phosphite, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite, and tricresyl phosphite.

  Specific examples of the phosphorothionate include tributyl phosphorothioate, tripentyl phosphorothioate, trihexyl phosphorothionate, triheptyl phosphorothionate, trioctyl phosphorothionate, trinonyl phosphate. Phorothionate, tridecyl phosphorothionate, triundecyl phosphorothionate, tridodecyl phosphorothionate, tritridecyl phosphorothionate, tritetradecyl phosphorothionate, tripentadecyl phosphorothionate, tri Hexadecyl phosphorothioate, triheptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleyl phosphorothionate, triphenyl phosphorothionate, tricresyl phosphorothioate , Trixylenyl phosphorothionate, cresyl diphenyl phosphorothionate, xylenyl diphenyl phosphorothionate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phosphorothionate, tris (N-Butylphenyl) phosphorothionate, Tris (isobutylphenyl) phosphorothionate, Tris (s-butylphenyl) phosphorothionate, Tris (t-butylphenyl) phosphorothionate, and the like can be given. Mixtures of these can also be used.

Examples of the zinc dithiophosphate generally include zinc dialkyldithiophosphate, zinc diaryldithiophosphate, zinc arylalkyldithiophosphate, and the like. 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.

  As the phosphorus-containing carboxylic acid compound such as phosphorus-containing carboxylic acid and ester, the structure is not particularly limited as long as both the carboxyl group and the phosphorus atom are included in the same molecule. From the viewpoint of oxidation stability, phosphorylated carboxylic acid or phosphorylated carboxylic acid ester is preferred. Examples of the phosphorylated carboxylic acid and phosphorylated carboxylic acid ester include compounds represented by the following general formula (8).

In the general formula (8), R ₆ and R ₇ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and R ₈ represents an alkylene group having 1 to 20 carbon atoms. R ₉ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and X ₁₁ , X ₁₂ , X ₁₃ and X ₁₄ may be the same or different and each represents an oxygen atom or a sulfur atom.
Examples of the hydrocarbon group having 1 to 30 carbon atoms in R ₆ and R ₇ in the general formula (8) include an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an arylalkyl group.

Among the phosphorylated carboxylic acids, useful β-dithiophosphorylated propionic acid has a structure represented by the following general formula (9).

  Specific examples of the β-dithiophosphorylated propionic acid include 3- (di-isobutoxy-thiophosphorylsulfanyl) -2-methyl-propionic acid.

  The content of the phosphorus-containing carboxylic acid compound in the lubricating oil composition is not particularly limited, but is preferably 0.001 to 1% by mass, more preferably 0.002 to 0.00% in the lubricating oil composition. 5% by mass. If the content of the phosphorus-containing carboxylic acid compound is less than the lower limit, sufficient lubricity tends to be not obtained. On the other hand, even if it exceeds the upper limit, there is a tendency that the lubricity improvement effect corresponding to the content does not tend to be obtained, and furthermore, there is a possibility that the heat / oxidation stability and the hydrolysis stability may be lowered.

In the phosphorylated carboxylic acid represented by the general formula (8), the content of the compound in which R ₉ is a hydrogen atom is 0.001 to 0.1% by mass, preferably 0.002 to 0. 0.08% by mass, more preferably 0.003 to 0.07% by mass, still more preferably 0.004 to 0.06% by mass, and still more preferably 0.005 to 0.05% by mass.

In order to improve low temperature fluidity and viscosity characteristics, a pour point depressant and a viscosity index improver may be added to the lubricating oil composition of the present invention.
Examples of the viscosity index improver include non-dispersed viscosity index improvers such as polymethacrylates, ethylene-propylene copolymers, styrene-diene copolymers, polyisobutylene, polystyrene and other olefin polymers, and nitrogen-containing compounds. Examples thereof include a dispersion type viscosity index improver obtained by copolymerizing monomers. The addition amount can be used in the range of about 0.05 to 20% by mass in the lubricating oil composition.
Examples of the pour point depressant include polymethacrylate polymers. The addition amount can be used in the lubricating oil composition in the range of about 0.01 to 5% by mass.

  In order to impart antifoaming properties to the lubricating oil composition of the present invention, an antifoaming agent may be added. Examples of antifoaming agents suitable for the present invention include organosilicates such as dimethylpolysiloxane, diethyl silicate and fluorosilicone, and non-silicone antifoaming agents such as polyalkyl acrylate. The addition amount can be used in the lubricating oil composition in the range of about 0.0001 to 0.1% by mass, alone or in combination.

  Demulsifiers suitable for the present invention include those commonly used as lubricating oil additives. The addition amount can be used in the lubricating oil composition in the range of about 0.0005 to 0.5% by mass.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited only to these Examples.
In preparing Examples and Comparative Examples, the following composition materials were prepared.
1. Base oil (1-1) Base oil 1: It was obtained by applying a suitable combination of refining means such as hydrocracking and dewaxing to a lubricating oil fraction obtained by atmospheric distillation of crude oil. Paraffinic mineral oil classified as Group 2 (Gp2) by API (American Petroleum Institute) base oil classification. (Characteristics: Kinematic viscosity at 100 ° C .; 5.35 mm ² / s, kinematic viscosity at 40 ° C .; 31.4 mm ² / s, viscosity index; 103, sulfur content (sulfur element equivalent value); less than 10 mass ppm, Nitrogen content (nitrogen element conversion value): less than 1 ppm by mass, aniline point; 110 ° C., 15 ° C. density; 0.863, 20 ° C. density; 0.860, 20 ° C. refractive index: 1.472, according to ASTM D2502 (Molecular weight: 411, paraffin content of ring analysis by ASTM D3238 method; 62%, naphthene content; 38%, same aroma content: less than 1%, initial boiling point temperature by gas chromatography by ASTM D5480 method; 312 ° C)
(1-2) Base oil 2: A paraffinic mineral oil produced by advanced hydrorefining of a lubricating oil fraction obtained by atmospheric distillation of crude oil, according to API (American Petroleum Institute) base oil classification Those classified into Group 3 (Gp3). (Characteristics: Kinematic viscosity at 100 ° C .; 6.57 mm ² / s, kinematic viscosity at 40 ° C .; 37.5 mm ² / s, viscosity index; 130, sulfur content (converted elemental value of sulfur); less than 10 mass ppm, Nitrogen content (nitrogen element conversion value); less than 1 ppm by mass, aniline point; 123 ° C., 15 ° C. density; 0.844, 20 ° C. density; 0.841, 20 ° C. refractive index; 1.465, according to ASTM D2502 Molecular weight: 479, paraffin content of ring analysis by ASTM D3238 method; 79%, aroma content; less than 1%, polycyclic aromatic content by IP346 method: 0.2%, initial boiling point temperature by gas chromatographic distillation by ASTM D5480 method 306 ° C)
(1-3) Base oil 3: GTL (Gas Liquid) synthesized by the Fischer-Tropsch method and classified into Group 3 (Gp3) by API (American Petroleum Institute) base oil classification. (Characteristics:; kinematic viscosity at 5.10mm ² / s, 40 ℃; kinematic viscosity at 100 ℃ 23.5mm ² / s, viscosity index; 153,15 ° C. Density; 0.821, sulfur content (terms of the sulfur element Value); less than 10 mass ppm, nitrogen content (nitrogen element equivalent value); less than 1 mass ppm, aniline point; 126 ° C., 15 ° C. density; 0.821, 20 ° C. density; 0.817, 20 ° C. refractive index 1.456, molecular weight according to ASTM D2502; 447, paraffin content of ring analysis by ASTM D3238 method; 95%, same aroma content: less than 1%, initial boiling point temperature by gas chromatography by ASTM D5480 method; 365 ° C.)
(1-4) Base oil 4: Synthetic oil; Poly-α-olefin synthesized by polymerization of α-decene, generic name PAO6, classified into group 4 (Gp4) by API (American Petroleum Institute) base oil classification. (Characteristics: Kinematic viscosity at 100 ° C .; 5.89 mm ² / s, kinematic viscosity at 40 ° C .; 31.2 mm ² / s, viscosity index; 135, 15 ° C. density; 0.827, sulfur content (in terms of elemental sulfur) Value); less than 10 mass ppm, nitrogen content (nitrogen element equivalent value); less than 1 mass ppm, aniline point; 128 ° C., 15 ° C. density; 0.827, 20 ° C. refractive index; 1.460, ASTM D5480 method First boiling point temperature by gas chromatographic distillation with 403 ℃
(1-5) Base oil 5: A paraffinic mineral oil obtained by applying a suitable combination of refining means such as dewaxing to a lubricating oil fraction obtained by atmospheric distillation of crude oil. API (American Petroleum Institute) Classified as Group 1 (Gp1) by base oil classification. (Characteristics: Kinematic viscosity at 100 ° C .; 4.60 mm ² / s, kinematic viscosity at 40 ° C .; 24.6 mm ² / s, viscosity index; 101, 15 ° C. density; 0.866, sulfur content (in terms of elemental sulfur) Value); 4500 mass ppm, nitrogen content (nitrogen element equivalent value); 20 mass ppm, parafun content of ring analysis by ASTM D3238 method; 66%, naphthene content; 31%, same aroma content; 3%, aniline Point: 99 ° C., polycyclic aromatic content by IP346 method: 0.8%, initial boiling point temperature by gas chromatography by ASTM D5480 method; 331 ° C.)

2. Additive
(2-1) Additive A1: Succinic acid derivative; tetraisopropenyl succinic acid, 1,2-propanediol half ester (acid value according to JIS K2501 method: 160 mgKOH / g)
(2-2) Additive A2: Succinic acid derivative; tetraisopropenyl succinic acid, 1,3-propanediol half ester (acid value according to JIS K2501 method: 160 mgKOH / g)
(2-3) Additive A3: Succinic acid derivative; Rhein Chemie RC4802 (Acid value according to ASTM D3739: 35 mgKOH / g)
(2-4) Additive B1: Epoxidized rapeseed fatty acid 2-ethylhexyl ester (2-5) Additive B2: Epoxidized rapeseed fatty acid isobutyl ester (2-6) Additive B3: Epoxidized soybean oil (2-7) Addition Agent C1: Coconut amine (main component is dodecylamine)
(2-8) Additive C2: N-alkenyldiethanolamine (main component is N-dodecyldiethanolamine): tertiary amine compound (base number according to JIS K2501 method: 160 mgKOH / g)
(2-9) Additive C3: N-alkenyldiethanolamine (main component is N-oleyldiethanolamine): tertiary amine compound (base number according to JIS K2501 method: 160 mgKOH / g)
(2-10) Additive D1: Polyamine amide (main component is isostearic acid triethylenetetraamide)
(2-11) Additive D2: Oleylamide (2-12) Additive E1: Trimethylolpropane monooleate (2-13) Additive E2: Pentaerythritol monooleate (2-14) Additive E3: Glycerol Monoisostearate (hydroxyl value according to JIS K0070 method: 313 mg KOH / g)

(Examples 1 to 23, Comparative Examples 1 to 9)
Using the above-described composition materials, lubricating oil compositions of Examples 1 to 23 and Comparative Examples 1 to 9 were prepared according to the compositions shown in Tables 1 to 7.

(test)
The following tests were conducted on the lubricating oil compositions of Examples 1 to 23 and Comparative Examples 1 to 9 to see their performance.

(Rust prevention test)
In accordance with JIS K2510, 300 ml of test oil is collected in a container installed in a thermostatic bath, stirred at 1000 revolutions per minute, and when the temperature reaches 60 ° C., an iron test piece is inserted into the test oil. 30 ml of artificial seawater was added and stirring was continued for 24 hours while maintaining the temperature at 60 ° C., and then the test piece was taken out and visually evaluated for the presence or absence of rust on the test piece.
The test was evaluated according to the following criteria.
No generation of rust ... ◎◎ (Pass)
The appearance of rust is generated .... × (Fail)

(Thermal stability test)
In accordance with THERMAL STABILITY TEST PROCEDURE “A” manufactured by CINCINNATI MILACRON, 200 ml of test oil was collected in a container placed in a thermostatic bath and left at 135 ° C. for 168 hours in the presence of a copper catalyst and an iron catalyst. Then, after cooling to room temperature, sludge was collected with a 5 micron filter, and the generated sludge weight was weighed. In addition, the numerical value in a table | surface is the amount of sludge (mg / 200ml) per 200ml of test oil.
The test was evaluated according to the following criteria.
Sludge amount is less than 2.5mg / 200ml ... Pass (◎)
Sludge amount is 2.5mg / 200ml or more ... Fail (×)

(Pendulum test, friction coefficient)
The coefficient of friction was measured with a Kamata-type pendulum type oiliness tester manufactured by Shinko Machine Co., Ltd. In this test, test oil is applied to the friction portion of the pendulum fulcrum, the pendulum is vibrated, and the friction coefficient is obtained from the vibration attenuation. It carried out about Examples 9-23 and Comparative Examples 1-9.
The test was evaluated according to the following criteria.
The coefficient of friction is 0.135 or less.
Coefficient of friction is more than 0.135 and less than 0.150 ... ○ (good)
The coefficient of friction is 0.150 or more.

(Test results)
Tables 1 to 7 show the results of each test.

(Discussion)
As is clear from the test results shown in Table 1, the group 2 base oil (base oil 1) shown in Examples 1 to 3 was used, and the succinic acid derivative (additive A1 or A2) and the epoxy compound (additive B1 or In the case of using B2) together, rust does not occur even in the artificial seawater of the rust prevention test, and it passes (◎), the amount of sludge generated is small, and the amount of sludge passes (◎).
Moreover, as shown in Examples 4 to 8 in Table 2, lubrication using any base oil of group 3 base oil (base oil 2), GTL (base oil 3), or PAO (base oil 4) as the base oil In the oil composition, rust does not occur and it passes (合格), and the amount of sludge generated is small, and the amount of sludge passes (◎).

In Table 3, in Examples 9-12, as the base oil, group 2 base oil (base oil 1), group 3 base oil (base oil 2), GTL (base oil 3), PAO (base oil 4) Any of these materials that use a succinic acid derivative (additive A1 or A2), an epoxy compound (additive B1 or B2), and an amine compound (additive C1) do not generate rust even in the rust prevention test. Passed (◎), passed sludge amount (◎), good coefficient of friction, small in Examples 10 and 11, excellent (◎), good in Examples 9 and 12 (Good). ing.
In addition, in the rust preventive test in which the succinic acid derivative (additive A3), the epoxy compound (additive B2) and the amine compound (additives C1 and C2 are used in combination) are added to the base oil 1 of Examples 13 and 14. No rust is generated and it passes (合格), and the amount of sludge also passes (◎), and the friction coefficient is small (優).

Examples 15 to 17 shown in Table 4 use either group 2 base oil (base oil 1) or GTL (base oil 3) as the base oil, and succinic acid derivative (additive A1). ), An epoxy compound (additive B1) and an amide compound (additive D1 or D2), and passed (◎) without rust generation in the rust prevention test, and sludge generation was small. The amount is also acceptable (合格), and the friction coefficient is excellent (◎) in Examples 16 and 17, and good (（) in Example 15.
Moreover, the thing of Examples 18-19 uses (base oil 1 or base oil 3) as a base oil, a succinic acid derivative (additive A1), an epoxy compound (additive B1), and a polyhydric alcohol ester (addition) Agent (E1 or E2) was used, passed (◎) in the rust prevention test, passed (◎) in the amount of sludge, and excellent in friction coefficient (◎).
Furthermore, the thing of Example 20 uses a base oil (base oil 1), a succinic acid derivative (additive A1), an epoxy compound (additive B1), an amine compound (additive C1), and an amide compound (additive). D1) was used, passed (合格) in the rust prevention test, passed (◎) in the amount of sludge generated, and excellent in friction coefficient (◎).

  Examples 21 to 23 shown in Table 5 use base oil (base oil 1), succinic acid derivative (additive A2 or A3), epoxy compound (additive B1 or B2), amine compound [(addition Agent C1 and C3) or (additives C1 and C2)] and polyhydric alcohol ester (additive E3), which passed (◎) in the rust prevention test and passed in the amount of sludge generated ( ◎), and the coefficient of friction is excellent (◎).

On the other hand, in Tables 6 and 7, Comparative Examples 1 to 8 use Group 2 base oil (Base Oil 1) as the base oil. The oil 1) alone passes (◎) in the amount of sludge, but fails (x) in the rust prevention test and friction coefficient. In the case where only the succinic acid derivative (additive A1 or A2) of Comparative Examples 2 and 3 was added, it passed (錆) in the rust prevention test, but failed (x) in terms of sludge amount and friction coefficient. Yes.
In Comparative Examples 4 and 5, only the epoxy compound (additive B2 or B3) was added, but Comparative Example 4 passed (◎) in the amount of sludge. Is rejected (x). In Comparative Example 5, the value of the sludge amount was too large, so the measurement of the friction coefficient was omitted.

Comparative Example 6 was obtained by adding only the amide compound (additive D1) to the base oil 1 and passed (◎) in the amount of sludge and friction coefficient, but failed (x) in the rust preventive test. Yes.
The thing of the comparative example 7 is what added only the amide compound (additive D2) to the base oil 1, and has passed ((double-circle)) by the friction coefficient, but it is disqualified (x) and sludge amount by the rust prevention property test. It is rejected (x).
Comparative Example 8 was obtained by adding only the polyhydric alcohol ester (additive E2) to the base oil 1 and passed (◎) in the rust-preventing property test and good in the friction coefficient (）), but in the amount of sludge. It is a pass (x).
The thing of the comparative example 9 is what uses croup 1 base oil (base oil 5) for base oil, and uses succinic acid derivative (additive A1) and an epoxy compound (additive B1) together, but rust prevention property Even if the test passes (◎), the sludge amount fails (x). Also in Comparative Example 9, the value of the sludge amount was too large, so measurement of the friction coefficient was omitted.
As described above, in each of the examples, superior results were obtained as compared with the comparative example, and it was found that the examples were preferable as the lubricating oil composition in the present invention.

Claims (7)

  A lubricating oil composition comprising a mineral oil and / or synthetic oil base oil having a sulfur content of 0.3% by mass or less and containing a succinic acid derivative and an epoxy compound as additives.   The lubricating oil composition according to claim 1, wherein the acid value of the succinic acid derivative is 10 to 300 mg KOH / g (JIS K2501).   The lubricating oil composition according to claim 1, wherein the epoxy compound is an epoxidized fatty acid ester.   The lubricating oil composition according to any one of claims 1 to 3, wherein the lubricating oil composition contains 0.001 to 0.5 mass% of the succinic acid derivative and 0.01 to 5 mass% of an epoxy compound. .   The lubricating oil composition according to any one of claims 1 to 4, further comprising at least one of an amine compound, an amide compound, and a polyhydric alcohol ester as an additive.   The lubricating oil composition according to any one of claims 1 to 5, wherein the base oil is GTL.   The lubricating oil composition according to any one of claims 1 to 5, wherein the base oil is a polyalphaolefin.