ES2384584T3 - Lubricating oil composition - Google Patents

Abstract

Lubricating oil composition characterized in that it comprises a basic oil; (A) an acid alkyl phosphate ester having a C6 to C20 alkyl group; (B) a dialkylamine and / or a trialkylamine in an amount such that the mass ratio of P contained in component (A) with respect to N contained in component (B) is adjusted to 1.7 to 2.1; and (C) (c-1) a sulfur compound in an amount of 0.2 at 0.6% by mass reduced to S, the sulfur compound not containing any poly-sulfur bond that is equal to or longer than -SS-Senuna molecule thereof and having an S content of the molecule of 15% by mass or more and (c-2) an optional thiophosphoric acid trihydrocarbyl ester in an amount of 0.1 to 1.0% by mass, the ester being represented by the formula (I) :( RO-) 3P> = S (I) (in which R represents a C6 to C20 hydrocarbyl group) and having a P content of the composition of 150 to 500 ppm by mass.

Description

Composition of lubricating oil.

[Technical field]

The present invention relates to a lubricating oil composition and, more particularly, to a lubricating oil composition having excellent non-stick performance, excellent anti-fatigue performance and reduced sludge formation in an oxidation test, and which is particularly suitable for use. with a multiplier gear for wind power generation.

[Background of the technique]

The demand for wind power generation is expected to increase, making use of renewable energy, as it will reduce the environmental burden and contribute to the conservation of fossil fuel, which have become important issues in recent years.

In wind power generation using the force of the wind, the kinetic energy of the wind is transformed into power by means of rotors that include propellers that the wind rotates. Through the power generated, a power generator works by producing electrical energy.

In wind power generation, a multiplier gear is used to raise the rotational speed of the rotors, which is relatively slow, so that the power generation efficiency of the power generator is improved. In fact, a variety of multiplier gears are known in the art, and among them, a planetary gear type power transmission apparatus is widely used.

In such an apparatus (for example, planetary gear-type power transmission apparatus) as used in wind power generation, an oil composition for multiplier gears is used and it is required that it has excellent non-stick performance and anti-fatigue performance, such as anti-corrosion performance by micro-bites of FZG, and that guarantees the minimization of the amount of sludge formed in an oxidation test.

A lubricating oil composition has been proposed for use in a multiplier gear used in a wind power generator, a composition that contains (a) an extreme pressure compound that includes a sulfur compound, (b) a mixture of a compound of hydrocarbylamine and an alkyl phosphorothioate compound, (c) a friction control compound and (d) a basic oil (see, for example, patent document 1).

However, it is not believed that the proposed lubricating oil composition exhibits the completely satisfactory performance required for gear oil multiplier compositions for wind power generation.

[Patent Document 1]

Japanese patent application open for public consultation (kokai) No. 2005-126709.

Japanese patent application JP2002-338983 (WO02 / 092735) discloses a gear oil composition comprising an acid phosphate ester, a dialkylamine and a sulfur compound without polyazufre bonds.

[Description of the invention]

[Problems to be solved by the invention]

In such circumstances, an object of the present invention is to provide a lubricating oil composition that has excellent non-stick performance, anti-fatigue performance and reduced sludge formation in an oxidation test, and that is properly used with a multiplier gear for power generation. wind.

[Means to solve the problems]

The present inventor has carried out extensive studies for the development of a lubricating oil composition that is excellent in the characteristics mentioned above, and has found that the object can be achieved by a lubricating oil composition containing a basic oil and (A) a specific acidic alkyl phosphate ester, (B) a specific alkylamine in an amount such that the mass ratio of P contained in component (A) with respect to N contained in component (B) is set to 1, 7 to 2.1, (C) and a specific sulfur compound, in combination, and having a specific P / S ratio. The present invention has been achieved based on this finding.

Accordingly, the present invention provides the following.

[1] A lubricating oil composition characterized in that it comprises: a basic oil; (A) an acid alkyl phosphate ester having a C6 to C20 alkyl group; (B) a dialkylamine and / or a trialkylamine; and (C) (c-1) a sulfur compound in an amount of 0.2 to 0.6% by mass reduced to S, the sulfur compound not containing any polyazufre bond that is equal to or longer than -SSS -in a miso molecule and having an S content of the molecule of 15% by mass or more and (c-2) an optional thiophosphoric acid trihydrocarbyl ester in an amount of 0.1 to 1.0% by mass, the ester being represented by the formula (I):

(R-O-) 3P = S ... (I)

(wherein R represents a C6 to C20 hydrocarbyl group) and having a P content of the composition of 150 to 500 ppm by mass.

[2] A lubricating oil composition as described in [1] above, wherein component (B) is a trialkylamine having a C6 to C20 alkyl group.

[3] A lubricating oil composition as described in [1] or [2] above, which further contains

(D) a partial polyol ester in an amount of 5 to 20% by mass.

[4] A lubricating oil composition as described in any of [1] to [3] above, which is used as an oil composition for multiplier gears for wind power generation.

[Effects of the invention]

The present invention can provide a lubricating oil composition that has excellent non-stick performance, excellent anti-fatigue performance (e.g., anti-corrosion performance by micro-pitting of FZG) and reduced sludge formation in an oxidation test, and that is suitably used with a multiplier gear for wind power generation.

[Best ways to carry out the invention]

The lubricating oil composition of the present invention is characterized in that it comprises: a basic oil; (A) an acid alkyl phosphate ester having a C6 to C20 alkyl group; (B) a dialkylamine and / or a trialkylamine in an amount such that the mass ratio of P contained in component (A) with respect to N contained in component (B) is adjusted to 1.7 to 2.1 ; and (C) (c-1) a sulfur compound in an amount of 0.2 to 0.6% by mass reduced to S, the sulfur compound not containing any polyazufre bond that is equal to or longer than -SSS -in a molecule thereof and having an S content of the molecule of 15% by mass or more and (c-2) an optional thiophosphoric acid trihydrocarbyl ester in an amount of 0.1 to 1.0% by mass, the ester being represented by the formula

(I): (R-O-) 3P = S ... (I)

(wherein R represents a C6 to C20 hydrocarbyl group) and having a P content of the composition of 150 to 500 ppm by mass.

The basic oil used in the lubricating oil composition of the present invention preferably has a kinematic viscosity as determined at 40 ° C of 30 to 800 mm2 / s and a viscosity index of 80 or higher. When the kinematic viscosity (40 ° C) is 30 mm2 / s or higher, the evaporation loss is small, while when it is 800 mm2 / s or less, the power loss due to viscous resistance does not increase excessively. The kinematic viscosity (40 ° C) is more preferably from 32 to 680 mm2 / s, particularly preferably from 100 to 500 mm2 / s. When the viscosity index is 80 or higher, the variation in viscosity with respect to the temperature variation is small. The viscosity index is more preferably 100 or higher, still more preferably 130 or higher.

The pour point is preferably -25 ° C or lower. When the pour point is -25 ° C or lower, the lubricating oil composition produced may have sufficient fluidity even at low temperature. The pour point is more preferably of -30 ° C or less, still more preferably of 40 ° C or less.

The kinematic viscosity and viscosity index mentioned above are determined according to JIS K 2283, and the pour point is determined according to JIS K 2265.

No particular limitation is imposed on the type of the basic oil, and either mineral oil or synthetic oil can be used. A variety of conventional mineral oils can be used. Examples of the mineral oil include paraffin-based mineral oil, intermediate mineral oil and naphthene-based mineral oil. Specific examples include light neutral oil, medium neutral oil, heavy neutral oil and hydrogenated or solvent refined heavy lubricant base.

In addition, a variety of conventional synthetic oils can be used. Examples of the synthetic oil include poly-a-olefin, polybutene, polyol ester, dibasic acid esters, phosphate esters, polyphenyl esters, alkylbenzenes, alkylnaphthalenes, polyoxyalkylene glycols, neopentyl glycol, silicone oil, trimethylolpropane, pentaerythritol and ester. These basic oils can be used individually or in combination of two or more species, and mineral oil and synthetic oil can be used in combination.

In the lubricating oil composition of the present invention, the C6 to C20 acid alkyl phosphate ester serving as component (A) can be a compound represented by the formula (II):

(wherein X1 represents a hydrogen atom or a C6 to C20 alkyl group, and X2 represents a C6 to C20 alkyl group).

The C6 to C20 alkyl group can be linear, branched or cyclic. Examples of the alkyl group include hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and icosyl. Of these, C10 to C18 alkyl groups are preferred.

Examples of the acid alkyl phosphate ester represented by the formula (II) include acidic phosphate monoesters such as monooctyl acid phosphate, monodecyl acid phosphate, monoisodecyl acid phosphate, monolauryl acid phosphate, mono (tridecyl) acid phosphate , monomyristyl acid phosphate, monopalmityl acid phosphate, monostearyl acid phosphate; and acid phosphate diesters such as dioctyl acid phosphate, didecyl acid phosphate, diisodecyl acid phosphate, dilauryl acid phosphate, di (tridecyl) acid phosphate, dipalmityl acid phosphate and distearyl acid phosphate.

In the present invention, the aforementioned alkyl acid phosphate esters serving as component (A) can be used individually or in combination of two or more species. The amount (s) of the phosphate ester (s) reduced to P is / are 150 to 500 ppm by mass with respect to the amount of lubricating oil composition. When the P content of the composition is less than 150 ppm by mass, the non-stick performance is insufficient, while when the P content is in excess of 500 ppm by mass, the anti-fatigue performance (anti-corrosion corrosion resistance of FZG) decreases The P content is preferably 250 to 450 ppm by mass, more preferably 350 to 400 ppm by mass.

Non-stick performance and anti-fatigue performance are evaluated through the following test methods.

<Non-stick performance>

(one)

 FZG adhesion test

The test is performed according to ASTM D 5182-91, at 90 ° C and 1,450 rpm for 15 minutes. The score is represented by a loading phase at which wear occurs.

(2)

 Timken test

The test is performed according to ASTM D 2782, at 800 rpm for 10 minutes. The score is represented by the maximum load (lbs) to which no adhesion occurs.

<Anti-fatigue performance>

(3) FZG micropicadura corrosion test

The test is performed through the same procedure that was used in the FZG adhesion test mentioned above, except that the score is represented by a loading phase in which micro-pitting corrosion occurs.

In the lubricating oil composition of the present invention, dialkylamine and / or trialkylamine serving as component (B) preferably has a C6 to C20 alkyl group.

Examples of dialkylamine include dihexylamine, dicyclohexylamine, dioctylamine, dilaurylamine and distearylamine. Examples of trialkylamine include trihexylamine, tricyclohexylamine, trioctylamine, trilaurylamine and trytearylamine.

In the lubricating oil composition of the present invention, the aforementioned dialkylamines and / or trialkylamines that serve as component (B) can be used individually or in combination of two or more species. Of these, trialkylamines are preferred from the standpoint of performance. When a monoalkylamine is used, the non-stick performance is altered.

Component (B) is incorporated into the composition in an amount such that the mass ratio of P contained in component (A) with respect to N contained in component (B) is adjusted to 1.7 to 2.1 . When the mass ratio is 1.7 or higher, good non-stick performance is achieved, while when the mass ratio is 2.1 or less, sludge formation in an oxidation test is avoided.

In the lubricating oil composition of the present invention, as sulfur compounds that serve as component (C), (c-1) a sulfur compound is used that does not contain any polyazufre bond that is equal to or longer than -SSS -in a molecule thereof and having an S content of the molecule of 15% by mass or more and (c-2) an optional thiophosphoric acid trihydrocarbyl ester represented by the formula (I):

(R-O-) 3P = S ... (I)

(in which R represents a C6 to C20 hydrocarbyl group).

When the sulfur compound that serves as component (c-1) has a poly-sulfur bond that is equal to or longer than -SSS-, a large amount of mud is formed in the Indiana oxidation test, and the anti-corrosion performance by FZG micropicadura decreases. When the S content of the molecule is less than 15% by mass, the effect of the sulfur compound cannot be achieved in proportion to the amount of addition and, in some cases, the non-stick performance is poor.

Examples of the sulfur compound that serves as component (c-1) and that has the properties mentioned above include the following compounds:

(one)

 olefin mono or disulfides,

(2)

 dihydrocarbyl mono or disulfides,

(3)

 thiadiazole compounds,

(4)

 dithiocarbamate compounds,

(5)

 ester compounds having a disulfide structure, and

(6)

 other sulfur compounds.

[Olefin mono or disulfide]

Examples of olefin sulfide include the compounds represented by formula (III):

R1-Sa-R2 ... (I)

(where R1 represents a C2 to C15 alkenyl group, R2 represents a C2 to C15 alkenyl group or group, and aes 1 or 2).

These compounds are produced through the reaction between a C2 to C15 olefin or a tetramer dimer thereof and a sulfurizing agent such as sulfur or sulfur chloride. Examples of preferred olefins include propylene, isobutene and diisobutene.

[Dihydrocarbyl mono or disulfide]

Examples of the dihydrocarbyl mono or disulfide include the compounds represented by the formula (IV):

R3-Sb-R4 ... (IV)

(wherein R3 and R4, which may be identical or different from each other, each represent a C1 to C20 alkyl group, a cycloalkyl group, a C6 to C20 aryl group, a C7 to C20 alkylaryl group or a C7 to C20 arylalkyl group , and b is 1 or 2). When R3 and R4 are alkyl groups, these compounds are called alkyl sulfide.

Examples of preferred dihydrocarbyl mono or disulfides represented by formula (IV) include dibenzyl mono or disulfide, various dinonyl mono or disulfides, various didodecyl mono or disulfides, various dibutyl mono or disulfides, various dioctyl mono or disulfides , various diphenyl mono or disulfide and various dicyclohexyl mono or disulfide.

[Thiadiazole compound]

Examples of preferred thiadiazole compounds include 2,5-bis (n-hexyldithium) -1,3,4-thiadiazole, 2,5bis (n-octyldithium) -1,3,4-thiadiazole, 2,5-bis ( n-nonildithio) -1,3,4-thiadiazole, 2,5-bis (1,1,3,3-tetramethylbutyldithium) -1,3,4thiadiazole, 3,5-bis (n-hexyldithium) -1,2 , 4-thiadiazole, 3,6-bis (n-octyldithium) -1,2,4-thiadiazole, 3,5-bis (n-nonildithio) -1,2,4thiadiazole, 3,5-bis (1,1 , 3,3-tetramethylbutyllithium) -1,2,4-thiadiazole, 4,5-bis (n-octyldithium) -1,2,3-thiadiazole, 4,5-bis (n-nonildithio) 1,2,3 -thiadiazole and 4,5-bis (1,1,3,3-tetramethylbutyldithium) -1,2,3-thiadiazole.

[Dithiocarbamate compound]

Examples of the dithiocarbamate compound include alkylene bisdialkyldithiocarbamates. Among them, preferably those having a C1 to C3 alkylene group, a linear or branched, saturated or unsaturated C3 to C20 alkyl group, or a C6 to C20 cycloalkyl group are employed. Specific examples of such dithiocarbamate compounds include methylene bisdibutyldithiocarbamate, methylene bisdioctyldithiocarbamate and methylene bistridecyldithiocarbamate.

[Ester compound having a disulfide structure]

Examples of the ester compound having a disulfide structure employed include disulfide compounds represented by the formula (V):

R5OOC-A1-S-S-A2-COOR6… (V)

and the disulfide compounds represented by the formula (VI):

R11OOC-CR13R14-CR15 (COOR12) -S-S-R20 (COOR17) -CR18R19-COOR16 ··· (VI).

In formula (V), each of R5 and R6 represents a C1 to C30 hydrocarbyl group (preferably a C1 to C20 hydrocarbyl group, more preferably C2 to C18, particularly preferably C3 to C18). The hydrocarbyl group may be linear, branched or cyclic, and may contain an oxygen atom, a sulfur atom or a nitrogen atom. R5 and R6 can be identical or different from each other. From the point of view of the production of the above compounds, the two groups are preferably identical to each other.

Each of A1 and A2 represents CR7R8 or CR7R8-CR9R10, in which each of R7 aR10 represents a hydrogen atom or a C1 to C20 hydrocarbyl group. The hydrocarbyl group is preferably a C1 to C12 hydrocarbyl group, more preferably a C1 to C8 hydrocarbyl group. A1 and A2 may be identical or different from each other. From the point of view of the production of the above compounds, the two groups are preferably identical to each other.

In the formula (VI), each of R11, R12, R16 and R17 represents a C1 to C30 hydrocarbyl group (preferably a C1 to C20 hydrocarbyl group, more preferably C2 to C18, particularly preferably C3 to C18). The hydrocarbyl group may be linear, branched or cyclic and may contain an oxygen atom, a sulfur atom or a nitrogen atom. R11, R12, R16 and R17 may be identical or different from each other. From the point of view of the production of the above compounds, these groups are preferably identical to each other.

Each of R13 aR15 and R18 aR20 represents a hydrogen atom or a C1 to C5 hydrocarbyl group. For reasons of availability, these groups are preferably hydrogen atoms.

Specific examples of the disulfide compound represented by the formula (V) include bis (methoxycarbonylmethyl) disulfide, bis (ethoxycarbonylmethyl) disulfide, bis (n-propoxycarbonylmethyl) disulfide, bis (isopropoxycarbonylmethyl) disulfide, bis (cyclopropoxycarbonyl disulfide) ), 1,1-bis (1-methoxycarbonylethyl) disulfide, 1,1-bis (1-methoxycarbonyl-n-propyl) disulfide, 1,1-bis (1-methoxycarbonyl-n-butyl) disulfide), 1,1-bis -bis (1-methoxycarbonyl-n-hexyl), 1,1-bis (1-methoxycarbonyl-n-octyl) disulfide,

2,2-bis (2-methoxycarbonyl-n-propyl), a, a-bis (a-methoxycarbonylbenzyl) disulfide, 1,1-bis (2-methoxycarbonylethyl) disulfide, 1,1-bis (2-ethoxycarbonylethyl) disulfide ), 1,1-bis (2-n-propoxycarbonylethyl) disulfide, 1,1-bis (2-isopropoxycarbonylethyl) disulfide, 1,1-bis (2-cyclopropoxycarbonylethyl) disulfide, 1,1bis (2-disulfide) -methoxycarbonyl-n-propyl), 1,1-bis (2-methoxycarbonyl-n-butyl) disulfide, 1,1-bis (2-methoxycarbonyl-n-hexyl) disulfide), 1,1-bis (2- methoxycarbonyl-n-propyl), 2,2-bis (3-methoxycarbonyl-npentyl) disulfide and 1,1-bis (2-methoxycarbonyl-1-phenylethyl) disulfide).

Specific examples of the disulfide compound represented by the formula (VI) include tetramethyl dithiomalate, tetraethyl dithiomalate, tetra-1-propyl dithiomalate, tetra-2-propyl dithiomalate, tetra-1-butyl dithiomalate, tetra dithiomalate -2-Butyl, tetraisobutyl dithiomalate, tetra-1-hexyl dithiomalate, tetra-1-octyl dithiomalate, tetra-1- (2-ethyl) hexyl dithiomalate, tetra-1- (3,5,5-trimethyl dithiomalate) ) hexyl, tetra-1-decyl dithiomalate, tetra-1-dodecyl dithiomalate, tetra-1-hexadecyl dithiomalate, dithiomalate

tetra-1-octadecyl, tetrabenzyl dithiomalate, tetra-a- (methyl) benzyl dithiomalate, tetra-a dithiomalate, adimethylbenzyl, tetra-1- (2-methoxy) ethyl dithiomalate, tetra-1- (2-dithiomalate) -ethoxy) ethyl, tetra-1- (2-butoxy) ethyl dithiomalate, tetra-1- (2-ethoxy) ethyl dithiomalate, tetra-1- (2-butoxy-butoxy) ethyl dithiomalate and tetra1- (2-dithiomalate) -phenoxy) ethyl.

[Other sulfur compounds]

Other sulfur compounds include sulfurized oils and fats such as sulfurized butter, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil and sulfurized rice bran oil; sulfurated fatty acids such as thioglycolic acid and thiooleic acid; dialkyl thiodipropionate compounds such as dilauryl thiodipropionate, distearyl thiodipropionate and dimiristyl thiodipropionate; and a tioterpene compound formed through the reaction between phosphorus pentasulfide and pinene.

In the lubricating oil composition of the present invention, the aforementioned sulfur compounds that serve as component (c-1) can be used individually or in combination of two or more species. Component (c-1) is required to be incorporated into the lubricating oil composition in an amount of composition of 0.2 to 0.6% by mass reduced to S. When the S content is less than 0.2 % by mass, the non-stick performance is not satisfactory, while when the S content is in excess of 0.6% by mass, the anti-fatigue performance such as resistance to micro-pitting corrosion of FZG is altered, and a large amount of mud in the Indiana oxidation test. Therefore, the S content is preferably 0.3 to 0.5% by mass.

The Indiana oxidation test is carried out through the following procedure.

<Indiana oxidation test>

The test is carried out according to the Indiana oxidation test method (Standard Oil Co.). Specifically, air is introduced into a sample (300 ml) at 10 l / hour and 121 ° C for 312 hours to cause forced deterioration. After the experiment, the generated sludge is recovered by means of a Millipore filter and weighed.

In the lubricating oil composition of the present invention, a thiophosphoric acid trihydrocarbyl ester represented by the formula (I) is used:

(R-O-) 3P = S ... (I)

as an optional component (c-2).

In formula (I), R represents a C6 to C20 hydrocarbyl group. The hydrocarbyl group represents a linear, branched or cyclic C6 to C20 alkyl group or alkenyl group, a C6 to C20 aryl group or a C7 to C20 aralkyl group. In the aryl group and aralkyl group, one or more alkyl groups can be attached to the corresponding aromatic ring. Three R-O-groups can be identical or different from each other.

Examples of the alkenyl group and C6 to C20 alkyl group include hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, cyclohexyl, hexenyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyls, octadecenyls and cyclohexenyl.

Examples of the C6 to C20 aryl group include phenyl, tolyl, xylyl, decylphenyl, 2,4-didecylphenyl and naphthyl. Examples of the C7 to C20 aralkyl group include benzyl, phenethyl, naphthylmethyl, methylbenzyl, methylphenethyl and methylnaphthylmethyl.

The specific ones of the trihydrocarbyl ester of the thiophosphoric acid represented by the formula (I) include trihexyl thiophosphate, tri-2-ethylhexyl thiophosphate, tris (decyl) thiophosphate, trilauryl thiophosphate, trimiristyl thiophosphate, thiophosphate trifophosphate , trioleyl thiophosphate, tricresyl thiophosphate, trixylyl thiophosphate, tris (decylphenyl) thiophosphate and tris [2,4-isoalkyl (C9, C10) phenyl] thiophosphate. These thiophosphoric acid trihydrocarbyl phosphates can be used individually or in combination of two or more species.

In the lubricating oil composition of the present invention, the thiophosphoric acid trihydrocarbyl ester optionally serving as component (c-2) is optionally added to the composition to further enhance the effect of the sulfur compound serving as component (c-1) . The amount of the component compound (c-2) is preferably 0.1 to 1.0% by mass based on the total amount of the lubricating oil composition, more preferably 0.2 to 0.5% by mass. However, the total amount of P in the lubricating oil composition is set at 150 to 500 ppm by mass.

If required, the lubricating oil composition of the present invention may additionally contain a partial polyol ester that serves as component (D). Component (D) also prevents sludge formation in the Indiana oxidation test.

No particular limitation is imposed on the polyol that serves as the starting material of the partial polyol ester, and an aliphatic polyol is preferred. Examples of the polyol include dihydroxylated alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol and neopentyl glycol; trihydroxylated alcohols such as glycerin, trimethylolethane and trimethylolpropane; and polyhydric (� tetravalent) alcohols such as diglycerin, triglycerin, pentaerythritol, dipentaerythritol, mannitol and sorbitol.

No particular limitation is imposed on the number of ester bonds in the partial ester, provided that at least one hydroxyl group remains. The hydrocarbyl group that forms the ester linkage (s) is preferably an alkenyl group or C6 to C20 alkyl group. Examples include hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, hexenyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyls and octadecenyls.

Specific examples of the partial polyol ester include, but are not limited to, neopentyl glycol monolaurate, neopentyl glycol monomiristate, neopentyl glycol monopalmitate, neopentyl glycol monostearate, neopentyl glycol monostearate, mono or trimethylolpropane trimethyl monopropane monourate, mono or trimethylolpropane dipalmitate, trimethylolpropane mono or distearate, trimethylolpropane mono or diiso stearate, glycerin mono or dilaurate, glycerin mono or distearate and glycerin mono or diisoestearate.

In the lubricating oil composition of the present invention, these partial polyol esters can be used individually or in combination of two or more species as component (D). The amount of partial polyol ester (s) incorporated in the composition is generally from about 5 to about 20% by mass, based on the total amount of the composition, more preferably from 7 to 15% by mass. , from the point of view of the prevention of sludge formation in the Indiana oxidation test.

In the lubricating oil composition of the present invention, provided that the objects of the present invention are not altered, at least one additive can be incorporated according to the needs, the additive being selected from a detergent-dispersant without ashes, an antioxidant, a anticorrosive, a metal deactivator, a viscosity index improver, a pour point reducer, a defoaming agent, etc.

Examples of the ash-free detergent dispersant include succinimides, boron-containing succinimides, benzylamines, boron-containing benzylamines, succinate esters, and mono- or divalent carboxamides including succinamides and fatty acid amides.

The antioxidant used may be an amine-based antioxidant, a phenol-based antioxidant or a sulfur-containing antioxidant, which are conventionally used in lubricating oil. These antioxidants can be used individually or in combination of two or more species. Examples of the amine-based antioxidant include monoalkyl diphenylamine compounds such as monooctyldiphenylamine and monononyldiphenylamine; dialkyl diphenylamine compounds such as 4,4’-dibutyldiphenylamine, 4,4’ diphenyl diphenylamine, 4,4’-dihexyldiphenylamine, 4,4’-diheptyldiphenylamine, 4,4’-dioctyldiphenylamine, and 4,4’dinonyldiphenylamine; polyalkyldiphenylamine compounds such as tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine and tetranonyldiphenylamine; and naphthylamine compounds such as a-naphthylamine, phenyl-anaphthylamine, butylphenyl-a-naphthylamine, pentylphenyl-a-naphthylamine, hexylphenyl-a-naphthylamine, heptylphenyl-a-naphthylamine, octylphenyl-a-naphthylamine and nonylphenyl-a-naphthylamine.

Examples of the phenol-based antioxidant include monophenol compounds such as 2,6-diterc-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol and 3- (3,5-di-tert -butyl-4-hydroxyphenyl) octadecyl propionate; and diphenol compounds such as 4,4’-methylenebis (2,6-di-tert-butylphenol) and 2,2’-methylenebis (4-ethyl-6-tert-butylphenol).

Examples of the sulfur-containing antioxidant include 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5triazin-2-ylamino) phenol; thioterpene compounds such as a reaction product between phosphorus pentasulfide and pinene; and dialkyl thiodipropionates such as dilauryl thiodipropionate and distearyl thiodipropionate.

Examples of the anticorrosive include metal sulphonates and esters of succinic acid, and examples of the metal deactivator include benzotriazole and thiadiazole.

Examples of the viscosity index improver include polymethacrylates, dispersion type polymethacrylates, olefin copolymers (eg, ethylene-propylene copolymer), dispersion type olefin copolymers and styrene copolymers (eg, styrene-diene hydrogenated copolymer ).

Examples of the pour point reducer employed in the invention include polymethacrylates having a weight average molecular weight of 50,000 to 150,000.

The defoaming agent is preferably a high molecular weight silicone defoaming agent or a polyacrylate defoaming agent. The incorporation of a defoaming agent such as a high molecular weight silicone defoaming agent in the composition of the invention effectively achieves the defoaming property.

Examples of the high molecular weight silicone defoaming agent include organopolysiloxanes. Of these, fluorine-containing organopolysiloxanes such as trifluoropropylmethyl silicone oil are particularly preferred.

The lubricating oil composition of the present invention is excellent in non-stick performance, excellent in anti-fatigue performance (eg, resistance to micro-pitting corrosion of FZG) and reduced sludge formation in an oxidation test. Therefore, the composition can be used as lubricating oils such as gear oil and bearing oil, and is particularly suitable for a lubricating oil for use in a planetary gear type power transmission apparatus in a wind power generator.

As described hereinbefore, the present invention relates to a lubricating oil composition comprising a basic oil, components (A) to (C) and an optional component (D). Generally, the lubricating oil composition comprises a basic oil, components (A) a

(C)

and a component (D). Examples The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

The properties of the basic oils used in the examples and those of the lubricating oil compositions obtained in the examples were determined by the following methods. <Properties of basic oils>

(one)

 Kinematic viscosity and viscosity index Determined according to JIS K 2283.

(2)

 Pour point

Determined according to JIS K 2265. <Performance of lubricating oil compositions>

(3)

 FZG adhesion test

The test was carried out according to a method described herein. Phase 13 is a step level.

(4)

 Timken test

The test was carried out according to a method described herein. The step level is 45 lbs or higher.

(5)

 FZG micropicadura corrosion test

The test was carried out according to a method described herein. Phase 9 is a step level.

(6)

 Indiana oxidation test The test was carried out according to a method described herein. Mud level

(determined by means of a Millipore filter) of 10 or less is a step level. The following components were used to prepare the lubricating oil compositions.

(one)

 Basic oil: PAO, α-olefin oligomer, kinematic viscosity (40 ° C) of 390 mm2 / s, viscosity index of 149 and pour point of -50 ° C or lower

(2)

 Acid phosphate esters -Isodecyl: (mono, di) isodecyl acid phosphate ester (mono: di (mol) = 1: 1) -Tridecil: phosphate ester of (mono, di) tridecyl acid (mono: di (mol) = 1: 1) -Isoamilo: phosphate ester of (mono, di) isoamyl acid (mono: di (mol) = 1: 1)

5 -2-Ethylhexyl: phosphate ester of (mono, di) -2-ethylhexyl acid (mono: di (mol) = 1: 1) -Oleílo: (mono, di) oleyl acid phosphate ester (mono: di (mol) = 1: 1)

(3) Amines -Trioctylamine -Dodecylamine

10 (4) Sulfur compounds -Dithiocarbamate: methylenebisdibutyl dithiocarbamate: S content of 30% by mass -Thiophosphate: tris thiophosphate (2,4-diisoalkyl (C9, C10) phenyl), S content of 44% by mass -Dibutyl Dithioglycolate: S content of 20% by mass -Tiadiazole: 2,5-bis (1,1,3,3-tetramethylbutanedithium) -1,3,4-thiadiazole, S content of 39% by mass

15-Butene sulphide: containing trisulfide bond (mono, di, tri and tetrasulfides, Sx: average of 2.3 x), S content of 40% by mass

(5) Polyol ester Partial ester: Trimethylolpropane ester and isostearic acid (1: 2 (mol)) Complete ester: Trimethylolpropane ester and isostearic acid (1: 3 (mol))

20 (6) Antioxidant

A: octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate

B: 4,4’-Dioctyldiphenylamine

(7) Anticorrosive: dialkylaminomethylbenzotriazole Examples 1 to 8 and comparative examples 1 to 7 25 Lubricating oil compositions were prepared having a formulation shown in Table 1, and

The characteristics of the compositions were evaluated. Table 1 shows the results. [Table 1] Table 1-1

Examples

one

2 3 4 5

Formulation (mass%)

Basic Oil (PAO) 86.32 86.28 86.68 86.33 86.93

Acid phosphate ester (A)

isodecyl  0.22 - - - -

tridecil

- 0.26 0.26 0.26 0.26

isoamyl

  - - - -

2-ethylhexyl

  - - - -

oil

  - - - -

Amine (B)

trioctylamine 0.36 0.36 0.36 0.36 0.36

dodecylamine

  - - - -

Sulfur Compound (C)

dithiocarbamate 1.65 1.65 1.65 - -

thiophosphate

0.40 0.40 - - -

dibutyl dithioglycolate

- - - 2.00  

thiadiazole

  - - - 1.50

butene sulfide

- - - - -

Polyol ester (D)

partial ester 10 10 10 10 10

complete ester

- - - - -

Antioxidant

TO 0.5 0.5 0.5 0.5 0.5

B

0.5 0.5 0.5 0.5 0.5

Anti-corrosive

0.05 0.05 0.05 0.05 0.05

P content of the composition (ppm by mass)

380 380 220 220 220

S content of the composition (mass%)

0.51 0.51 0.49 0.40 0.45

[P in (A)] / [N in (B)] (mass)

1.9 1.9 1.9 1.9 1.9

performance

Timken test (lbs) 65 60 Four. Five fifty Four. Five

FZG adhesion test

phase 12 pass pass pass pass pass

phase 13

pass pass pass pass pass

phase 14

pass pass does not happen pass pass

FZG micropicadura corrosion test

phase 8 pass pass pass pass pass

phase 9

pass pass pass pass pass

phase 10

pass pass pass does not happen does not happen

Indiana oxidation test

Fil-tro Millipore 2 one 4 7 5

[Table 2] Table 1-2 [Table 3] Table 1-3

Examples

Eg comp.

6

7 8 one 2

Formulation (mass%)

Basic Oil (PAO) 96.28 86.28 86.37 86.42 85.66

Acid phosphate ester (A)

isodecyl   - - - -

tridecil

 0.26 0.26 - - 0.52

isoamyl

- - - 0.12 -

2-ethylhexyl

- - 0.17 - -

oil

  - - - -

Amine (B)

trioctylamine 0.36 0.36 0.36 0.36 0.72

dodecylamine

  - - - -

Sulfur Compound (C)

dithiocarbamate  1.65 1.65 1.65 1.65 1.65

thiophosphate

0.40 0.40 0.40 0.40 0.40

dibutyl dithioglycolate

- - - - -

thiadiazole

- - - - -

butene sulfide

- - - - -

Polyol ester (D)

partial ester - - 10 10 10

complete ester

- 10 - - -

Antioxidant e

TO 0.5 0.5 0.5 0.5 0.5

B

0.5 0.5 0.5 0.5 0.5

Anti-corrosive

0.05 0.05 0.05 0.05 0.05

P content of the composition (ppm by mass)

380 380 380 380 600

S content of the composition (mass%)

0.51 0.51 0.51 0.51 0.51

[P in (A)] / [N in (B)] (mass)

1.9 1.9 1.9 1.9 1.9

performance

Timken test (lbs) 55 60 fifty 70 65

FZG adhesion test

phase 12 pass pass pass pass pass

phase 13

pass pass pass pass pass

phase 14

does not happen pass pass pass pass

FZG micropicadura corrosion test

phase 8 pass pass pass pass pass

phase 9

pass pass pass does not happen does not happen

phase 10

pass pass pass does not happen does not happen

Indiana oxidation test

Millipore filter 40 35 fifteen 100 18

Eg comp.

3

4 5 6 7

Formulation (mass%)

Basic Oil (PAO) 87.08 86.21 86.47 87.51 Commercial oil

Acid phosphate ester (A)

isodecyl   - - -

tridecil

 0.26 - 0.26 0.26

isoamyl

- - - -

2-ethylhexyl

- - - -

oil

  0.33 - -

Amine (B)

trioctylamine 0.36 0.36 - 0.36

dodecylamine

  - 0.17

Sulfur Compound (C)

dithiocarbamate   1.65 1.65 0.82

thiophosphate

- 0.40 0.40 -

dibutyl dithioglycolate

- - - -

thiadiazole

- - - -

butene sulfide

1.25 - - -

Polyol ester (D)

partial ester 10 10 10 10

complete ester

- - - -

Antioxidant

TO 0.5 0.5 0.5 0.5

B

0.5 0.5 0.5 0.5

Anti-corrosive

0.05 0.05 0.05 0.05

P content of the composition (ppm by mass)

220 380 380 220 570

S content of the composition (mass%)

0.51 0.51 0.51 0.17 0.44

[P in (A)] / [N in (B)] (mass)

1.9 1.9 1.9 1.9 -

performance

Timken test (lbs) 60 40 fifty 35 Four. Five

FZG adhesion test

phase 12 pass pass pass pass pass

phase 13

pass pass does not happen does not happen pass

phase 14

pass does not happen does not happen does not happen does not happen

FZG micropicadura corrosion test

phase 8 pass pass pass pass pass

phase 9

does not happen pass pass pass does not happen

phase 10

does not happen pass pass pass does not happen

Indiana oxidation test

Millipore filter 90 fifty 4 6 120

As is clear from Table 1, the lubricating oil compositions of Examples 1 through 5 passed all the Timken test, the FZG adhesion test, the FZG micro-pitting corrosion test and the oxidation test. from Indiana. The lubricating oil composition of example 6

5 does not contain partial polyol ester, and that of example 7 contains a complete polyol ester. These two compositions provide a relatively large amount of sludge in the Indiana oxidation test. The lubricating oil composition of Example 8, which contains 2-ethylhexyl acid phosphate (C8 alkyl) as an acid phosphate ester, provides a slightly large amount of sludge in the Indiana oxidation test.

The lubricating oil compositions of comparative examples 1 to 6 have at least one property that is outside the scope of the present invention. Therefore, their performance is lower than that of the compositions of the examples.

A commercial product (comparative example 7) provides a considerable amount of sludge in the Indiana oxidation test.

[Industrial Applicability]

The lubricating oil composition of the present invention has excellent non-stick performance, excellent anti-fatigue performance (eg, anti-corrosion performance by micro-pitting of FZG) and reduced sludge formation in an oxidation test, and is suitably used as a lubricating oil such as oil. for gears or bearing oil. The composition is particularly suitable as a lubricating oil for use with a multiplier gear (for example, gear type power transmission apparatus

20 planetarium) in a wind power generator.

Claims (4)

1. Composition of lubricating oil characterized in that it comprises a basic oil; (A) an acid alkyl phosphate ester having a C6 to C20 alkyl group; (B) a dialkylamine and / or a trialkylamine in an amount such that the mass ratio of P contained in component (A) with respect to N contained in component (B) is adjusted to 1.7 to 2, one; and (C) (c-1) a sulfur compound in an amount of 0.2 to 0.6% by mass reduced to S, the sulfur compound not containing any polyazufre bond that is equal to or longer than -SS -In a molecule thereof and having an S content of the molecule of 15% by mass or more and (c-2) an optional thiophosphoric acid trihydrocarbyl ester in an amount of 0.1 to 1.0% by mass, the ester being represented by the formula (I): (R-O-) 3P = S (I) (wherein R represents a C6 to C20 hydrocarbyl group) and having a P content of the composition of 150 to 500 ppm by mass. 2. A lubricating oil composition according to claim 1, wherein component (B) is a trialkylamine having a C6 to C20 alkyl group.

3.

Lubricating oil composition according to claim 1, further containing (D) a partial polyol ester in an amount of 5 to 20% by mass.

Four.

Lubricating oil composition according to any one of claims 1 to 3, which is used as an oil composition for multiplier gears for wind power generation.