JP2019137748A - Additive composition for lubricant oil, and lubricant oil composition - Google Patents

Abstract

To provide an additive composition for lubricant oil, capable of preventing corrosive wear when an anti-wear agent and an extreme pressure agent are used together.SOLUTION: The additive composition for lubricant oil comprises an anti-wear agent represented by formula (1) and an extreme pressure agent such as a compound represented by formula (2). [R, R, Rrepresent a monovalent hydrocarbon group. R, R, R, Reach independently represent a hydrogen atom or an alkyl group. Rrepresents a hydrogen atom or a carboxyl group, and Xrepresents a sulfur atom or an oxygen atom.]SELECTED DRAWING: None

Description

  The present invention relates to an additive composition for lubricating oil and a lubricating oil composition.

  Conventionally, lubricating oil has been used in mechanical devices such as industrial machines in order to improve lubricity between members. In recent years, mechanical devices such as hydraulic machines, compressors, turbines, gears, and bearings have been operated under harsh conditions as mechanical devices have been increased in speed and size. Therefore, the lubricating oil used in these mechanical devices is required to further improve the lubricating performance.

  Generally, in order to improve the lubricating performance of a lubricating oil, an additive is blended in the lubricating base oil according to desired characteristics. For example, Patent Document 1 discloses a lubricating oil composition in which a lubricant base oil is blended with an antiwear agent such as tricresyl phosphate (TCP) and a sulfur-based extreme pressure agent. The composition is said to be able to improve the extreme pressure effect while maintaining the antiwear effect.

JP 2003-171684 A

  However, the present inventors have found that when a sulfur-based extreme pressure agent is used in combination with a sulfur-based extreme pressure agent in a lubricating oil composition containing an anti-wear agent such as TCP, an extreme pressure effect is caused. And obtained knowledge that it can cause troubles in machinery and equipment.

  The present invention has been made in view of such circumstances, and an additive composition for lubricating oil that can prevent corrosive wear and the lubricating oil when the antiwear agent and the extreme pressure agent are used in combination. It is an object of the present invention to provide a lubricating oil composition containing the additive composition.

  The present invention relates to an antiwear agent represented by the following general formula (1), a compound represented by the following general formula (2), an acid anhydride of a compound represented by the following general formula (2), and the following general formula And at least one extreme pressure agent selected from the group consisting of an adduct obtained by adding an aliphatic monoalcohol, an alkylene glycol or a dialkylene glycol to at least one carboxyl group of the compound represented by the formula (2). An additive composition for oil is provided.

［式（１）中、Ｒ^１は１価の炭化水素基を表し、Ｒ^２及びＲ^３はそれぞれ独立に水素原子又はアルキル基を表す。］

[In Formula (1), R ¹ represents a monovalent hydrocarbon group, and R ² and R ³ each independently represent a hydrogen atom or an alkyl group. ]

［式（２）中、Ｒ^４及びＲ^５はそれぞれ独立に１価の炭化水素基を表し、Ｒ^６は水素原子又はカルボキシル基を表し、Ｒ^７及びＲ^８はそれぞれ独立に水素原子又はアルキル基を表し、Ｘ^１は硫黄原子又は酸素原子を表す。］

[In Formula (2), R ⁴ and R ⁵ each independently represent a monovalent hydrocarbon group, R ⁶ represents a hydrogen atom or a carboxyl group, and R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group. X ¹ represents a sulfur atom or an oxygen atom. ]

  Moreover, this invention provides the lubricating oil composition containing lubricating oil base oil and the additive composition for lubricating oils which concerns on this invention mentioned above.

  ADVANTAGE OF THE INVENTION According to this invention, when using both an antiwear agent and an extreme pressure agent, the lubricating oil additive composition which can prevent corrosion wear, and the lubricating oil composition containing the said lubricating oil additive composition Can be provided.

  The additive composition for lubricating oil according to the present embodiment is represented by the antiwear agent represented by the following general formula (1), the compound represented by the following general formula (2), and the following general formula (2). And at least one selected from the group consisting of an adduct obtained by adding an aliphatic monoalcohol, alkylene glycol or dialkylene glycol to at least one carboxyl group of a compound represented by the following general formula (2). A species of extreme pressure agent.

［式（１）中、Ｒ^１は１価の炭化水素基を表し、Ｒ^２及びＲ^３はそれぞれ独立に水素原子又はアルキル基を表す。］

[In Formula (1), R ¹ represents a monovalent hydrocarbon group, and R ² and R ³ each independently represent a hydrogen atom or an alkyl group. ]

［式（２）中、Ｒ^４及びＲ^５はそれぞれ独立に１価の炭化水素基を表し、Ｒ^６は水素原子又はカルボキシル基を表し、Ｒ^７及びＲ^８はそれぞれ独立に水素原子又はアルキル基を表し、Ｘ^１は硫黄原子又は酸素原子を表す。］

[In Formula (2), R ⁴ and R ⁵ each independently represent a monovalent hydrocarbon group, R ⁶ represents a hydrogen atom or a carboxyl group, and R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group. X ¹ represents a sulfur atom or an oxygen atom. ]

  By using the above additive composition for lubricating oil, corrosion wear of the lubricating oil composition can be prevented even when the antiwear agent and the extreme pressure agent are used in combination. The present inventors infer the reason why such an effect is obtained as follows. First, when a compound having a sulfur atom in the molecule (sulfur-based extreme pressure agent) is used as an extreme pressure agent, there is a risk of causing corrosion wear due to sulfur atoms. In this case, when conventional TCP or the like is used as an antiwear agent to be used in combination, the amount of TCP adsorbed on the friction surface is not sufficient, so that formation of a phosphoric acid film by TCP becomes insufficient, and corrosive wear due to a sulfur-based extreme pressure agent. Can not be prevented. On the other hand, in the additive composition for lubricating oil according to the present embodiment, the compound represented by the general formula (1) as an antiwear agent is excellent in the adsorptive power to the friction surface. It is thought that the formation of the phosphoric acid film was sufficient and corrosion wear due to the sulfur-based extreme pressure agent could be prevented.

  Moreover, by using the additive composition for lubricating oil, it is possible to provide a lubricating oil composition that is excellent in both the anti-wear effect and the extreme pressure effect. Furthermore, since the antiwear agent represented by the general formula (1) can improve not only the antiwear effect in the middle load region but also the oily effect in the low load region, it can be used under a wider range of load conditions. Excellent load resistance can be achieved.

  The additive composition for lubricating oil according to the present embodiment contains a compound represented by the following general formula (1) as an antiwear agent.

In Formula (1), R ¹ represents a monovalent hydrocarbon group, preferably a linear or branched alkyl group, and more preferably a linear alkyl group. The carbon number of the monovalent hydrocarbon group or alkyl group represented by R ¹ is preferably 6 to 24, more preferably 8 to 18, and still more preferably 12 to 18. Examples of the monovalent hydrocarbon group or alkyl group represented by R ¹ include an octyl group, a stearyl group, a dodecyl group, a decyl group, and a hexyl group. Among them, the oily effect of the lubricating oil composition is further increased. From the viewpoint of improvement, R ¹ is preferably an octyl group, a stearyl group, or a dodecyl group.

In formula (1), R ² and R ³ each independently represent a hydrogen atom or an alkyl group. The alkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 3 carbon atoms. From the viewpoint of further preventing the corrosion wear of the lubricating oil composition and further improving the wear prevention effect, it is preferable that R ² and R ³ are each independently a hydrogen atom, a methyl group or an ethyl group.

  Examples of the compound represented by the general formula (1) include dimethyl stearyl phosphonate, ethyl stearyl phosphonate, diethyl stearyl phosphonate, diethyl octyl phosphonate, dimethyl dodecyl phosphonate, dimethyl decyl phosphonate, and the like.

  The compound represented by the general formula (1) can be obtained, for example, by reacting an olefin with a dialkylphosphonic acid.

  In the additive composition for lubricating oil, the compound represented by the general formula (1) may be used singly or in combination of two or more.

  The additive composition for lubricating oil according to this embodiment includes a compound represented by the following general formula (2), an acid anhydride of a compound represented by the following general formula (2), and the following general formula (2). At least one extreme pressure selected from the group consisting of an adduct obtained by adding an aliphatic monoalcohol, alkylene glycol or dialkylene glycol to at least one carboxyl group of the represented compound (hereinafter also simply referred to as “adduct”) Contains agents.

In formula (2), R ⁴ and R ⁵ each independently represents a monovalent hydrocarbon group, preferably a linear or branched alkyl group. Carbon number of the monovalent hydrocarbon group or alkyl group represented by R ⁴ and R ⁵ is preferably 1 to 12, more preferably 2 to 10, and further preferably 3 to 8.

In formula (2), R ⁶ represents a hydrogen atom or a carboxyl group. In formula (2), R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group. Carbon number of the alkyl group represented by R ⁷ and R ⁸ is preferably 1 to 3. Examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, and an i-propyl group.

X ¹ represents a sulfur atom or an oxygen atom, and preferably represents a sulfur atom.

When R ⁶ is a carboxyl group and X ¹ is a sulfur atom, the compound represented by the formula (2) is obtained by, for example, reacting phosphorus pentasulfide with an alcohol to obtain a dithiophosphate ester. It can be obtained by reacting an acid ester with maleic anhydride, followed by hydrolysis. In the compound represented by the formula (2), when R ⁶ is a carboxyl group and X ¹ is an oxygen atom, for example, hydrogen phosphite, Na alkoxide and elemental sulfur are reacted to form Na dialkylthiophosphate. After obtaining, dialkylthiophosphoric acid is obtained by acid decomposition. It can be obtained by reacting the dialkylthiophosphoric acid and maleic anhydride, followed by hydrolysis.

In formula (2), the acid anhydride of the compound represented by formula (2) when R ⁶ is a carboxyl group is represented by the following formula (2a).

Wherein ^{(2a), R 4, R} 5, R 7, R 8 and ^{X 1} is a ^{R 4, R 5, R 7} , R 8 and ^{X 1} same definitions and contents in each formula (2) . Preferred embodiments of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ¹ are the same as those of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ^{1 in} the general formula (2), respectively, and overlap here. Description is omitted.

Acid anhydride of the compound represented by formula (2) (compound represented by the formula (2a)), when X ¹ is a sulfur atom, for example, a dithiophosphoric acid by reacting phosphorus pentasulfide with an alcohol It is obtained by obtaining an ester and reacting this dithiophosphate with maleic anhydride. The acid anhydride of the compound represented by the formula (2) (compound represented by the above formula (2a)) reacts, for example, hydrogen phosphite, Na alkoxide, and elemental sulfur when X ¹ is an oxygen atom. After obtaining Na dialkylthiophosphate, dialkylthiophosphate is obtained by acid decomposition. It can be obtained by reacting this dialkylthiophosphoric acid with maleic anhydride.

  The adduct is, for example, a dehydration condensate of a compound represented by the formula (2) and an aliphatic monoalcohol, alkylene glycol or dialkylene glycol, and at least one carboxyl group of the compound represented by the formula (2) And an ester bond formed from a hydroxyl group of aliphatic monoalcohol, alkylene glycol or dialkylene glycol.

  The adduct added with the aliphatic monoalcohol can be obtained, for example, by reacting the compound represented by the formula (2a) with the aliphatic monoalcohol for 1 hour at 60 ° C., for example.

  The adduct added with alkylene glycol or dialkylene glycol can be obtained, for example, by reacting the compound represented by the formula (2a) with alkylene glycol or dialkylene glycol, for example, at 80 ° C. for 4 hours. .

  The number of carbon atoms of the aliphatic monoalcohol is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 2.

  Carbon number of alkylene glycol becomes like this. Preferably it is 2-6, More preferably, it is 2-5, More preferably, it is 2-4. Dialkylene glycols are dimers of these alkylene glycols.

In formula (2), the adduct when R ⁶ is a carboxyl group may be a compound represented by the following general formula (2b).

Wherein ^{(2b), R 4, R} 5, R 7, R 8 and ^{X 1} is an ^{R 4, R 5, R 7} , R 8 and ^{X 1} same definitions and contents in each formula (2) , R ⁹ and R ¹⁰ each independently represent a divalent hydrocarbon group, R ^a and R ^b each independently represent a hydrogen atom or a monovalent hydrocarbon group, and m and n each independently represents 0 to 2 Represents an integer. However, at least one of the following conditions is satisfied.
(I) m is 1 or more, and R ^a is a hydrogen atom.
(Ii) n is 1 or more, and R ^b is a hydrogen atom.

Preferred embodiments of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ¹ are the same as those of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ^{1 in} the general formula (2), respectively. Description to be omitted is omitted.

R ⁹ and R ¹⁰ are each independently preferably a linear or branched alkylene group. The carbon number of the divalent hydrocarbon group or alkylene group represented by R ⁹ and R ¹⁰ is preferably 2 to 6, more preferably 2 to 5, and still more preferably 2 to 4.

R ^a and R ^b are each independently preferably a hydrogen atom or a linear or branched alkyl. The carbon number of the monovalent hydrocarbon group or alkyl group represented by R ^a and R ^b is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 2. It is preferable that both R ^a and R ^b are hydrogen atoms.

In formula (2), the adduct when R ⁶ is a carboxyl group may be a compound represented by the following general formula (2c).

Wherein ^{(2c), R 4, R} 5, R 7, R 8 and ^{X 1} is an ^{R 4, R 5, R 7} , R 8 and ^{X 1} same definitions and contents in each formula (2) , R ^c and R ^d each independently represents a hydrogen atom or an alkyl group. However, at least one of R ^c and R ^d is an alkyl group.

Preferred embodiments of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ¹ are the same as those of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ^{1 in} the general formula (2), respectively. Description to be omitted is omitted.

R ^c and R ^d are each independently preferably a hydrogen atom or a linear or branched alkyl group. The number of carbon atoms of the alkyl group represented by R ^c and ^{R d,} preferably 1 to 6, more preferably 1 to 4, more preferably 1 to 2. It is preferable that only one of R ^c and R ^d is an alkyl group.

In formula (2), the adduct when R ⁶ is a hydrogen atom may be a compound represented by the following general formula (2d).

Wherein ^{(2d), R 4, R} 5, R 7, R 8 and ^{X 1} is an ^{R 4, R 5, R 7} , R 8 and ^{X 1} same definitions and contents in each formula (2) , R ¹¹ represents a divalent hydrocarbon group, R ^e represents a hydrogen atom or a monovalent hydrocarbon group, and p represents an integer of 0 to 2. However, when ^Re is a hydrogen atom, p is an integer of 1 or more.

Preferred embodiments of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ¹ are the same as those of R ⁴ , R ⁵ , R ⁷ , R ⁸ and X ^{1 in} the general formula (2), respectively. Description to be omitted is omitted.

R ¹¹ is preferably a linear or branched alkylene group. The carbon number of the divalent hydrocarbon group or alkylene group represented by R ¹¹ is preferably 2 to 6, more preferably 2 to 5, and still more preferably 2 to 4.

R ^e is preferably a hydrogen atom or a linear or branched alkyl. The number of carbon atoms of the monovalent hydrocarbon group or an alkyl group represented by R ^e is preferably 1-6, more preferably 1-4, still more preferably 1-2.

  The extreme pressure agent may be one of the above compounds or a mixture of two or more. The extreme pressure agent is preferably a compound represented by the formula (2) or an adduct represented by the formula (2c).

  In the additive composition for lubricating oil, the content ratio of the extreme pressure agent to the antiwear agent represented by the general formula (1) is preferably 0.002 in terms of mass ratio from the viewpoint of sufficiently ensuring extreme pressure. As mentioned above, More preferably, it is 0.005 or more, More preferably, it is 0.01 or more. The content ratio is preferably 0.5 or less, more preferably 0.1 or less, and still more preferably 0.05 or less in terms of mass ratio from the viewpoint of sufficiently preventing corrosion wear.

  The lubricating oil composition according to the present embodiment includes a lubricating base oil and the lubricating oil additive composition according to the present embodiment described above.

  The lubricating base oil is, for example, mineral oil, synthetic oil, or a mixture of both.

  As mineral oils, lubricating oil fractions obtained by atmospheric distillation and vacuum distillation of crude oil are removed from solvents, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, clay. Examples thereof include paraffinic and naphthenic mineral oils, normal paraffins, isoparaffins, and the like, which are purified by combining purification treatments such as treatment alone or in combination of two or more. These mineral oils may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.

Preferred base oils include the following base oils.
(1) Distilled oil obtained by atmospheric distillation of paraffin-based crude oil and / or mixed-base crude oil (2) Vacuum-distilled distilled oil (WVGO) of atmospheric distillation residue oil of paraffin-based crude oil and / or mixed-base crude oil )
(3) Wax obtained by a lubricant dewaxing step and / or a Fischer-Tropsch wax produced by a GTL process or the like (4) One or more mixed oils selected from the above (1) to (3) Mild hydrocracking oil (MHC)
(5) Mixed oil of two or more oils selected from the above (1) to (4) (6) Detachment of (1), (2), (3), (4) or (5) Oil (DAO)
(7) Mild hydrocracking treatment oil (MHC) of (6) above
(8) A mixed oil or the like of two or more kinds of oils selected from the above (1) to (7) is used as a raw oil, and this raw oil and / or a lubricating oil fraction recovered from this raw oil is usually used. Oil obtained by refining by the refining method and recovering the lubricating oil fraction

Here, as a normal refining method, a refining method used in base oil production can be arbitrarily adopted. Examples of normal purification methods include the following purification methods.
(A) Hydrorefining such as hydrocracking, hydrofinishing, etc. (b) Solvent refining such as extraction of furfural solvent (c) Dewaxing such as solvent dewaxing, catalytic dewaxing, etc. Purification (e) Chemical (acid or alkali) purification such as sulfuric acid washing and caustic soda washing These purification methods can be used singly or in combination of two or more and in any order.

  Synthetic oils include, for example, esters, ethers and hydrocarbon oils.

  The ester is preferably an ester of a fatty acid (monobasic acid) and an alcohol and an ester of a polybasic acid and an alcohol, more preferably an ester of a fatty acid and an alcohol.

  The fatty acid may be a saturated fatty acid or an unsaturated fatty acid, and is preferably an unsaturated fatty acid.

  The fatty acid is preferably a fatty acid having 2 to 24 carbon atoms. Specific examples of fatty acids having 2 to 24 carbon atoms include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, Saturated fatty acids such as tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, henicosanoic acid, docosanoic acid, tricosanoic acid, tetracosanoic acid, acrylic acid, butenoic acid, pentenoic acid, hexenoic acid, heptene Acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, octadecenoic acid, nonadecenoic acid, icosenoic acid, heicosenoic acid, docosenoic acid, tricosenoic acid, Unsaturated fats such as tetracosenoic acid , And the like and mixtures thereof. These fatty acids may be linear or branched.

  Examples of polybasic acids include dibasic acids and tribasic acids. The polybasic acid may or may not have an unsaturated bond. The carbon number of the dibasic acid may be, for example, 2-16. Specific examples of the dibasic acid having 2 to 16 carbon atoms include ethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, and decane. Diacid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, heptadecanedioic acid, hexadecanedioic acid, hexenedioic acid, heptenedioic acid, octenedioic acid, nonenedioic acid, decenedioic acid, heptadecenedioic acid , Hexadecenedioic acid and mixtures thereof. These dibasic acids having 2 to 16 carbon atoms may be linear or branched. Examples of the tribasic acid include trimellitic acid.

  The alcohol may be a monohydric alcohol or a polyhydric alcohol. Carbon number of monohydric alcohol becomes like this. Preferably it is 1-24, More preferably, it is 1-12, More preferably, it is 1-8. Specific examples of the alcohol having 1 to 24 carbon atoms include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, Hexadecanol, heptadecanol, octadecanol, nonadecanol, icosanol, henycosanol, tricosanol, tetracosanol, and mixtures thereof can be mentioned. These monohydric alcohols may be linear or branched.

  The number of hydroxyl groups contained in the polyhydric alcohol (polyol) is preferably 2 to 10, more preferably 2 to 6. Specific examples of the polyhydric alcohol having 2 to 10 hydroxyl groups include ethylene glycol, diethylene glycol, polyethylene glycol (3 to 15 mer of ethylene glycol), propylene glycol, dipropylene glycol, and polypropylene glycol (of propylene glycol). 3 to 15-mer), 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 2-methyl- Dihydric alcohols such as 1,3-propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, neopentyl glycol; glycerin, polyglycerin (glycerin 2 to 8 mer, such as diglycerin Triglycerin, tetraglycerin, etc.), trimethylol alkanes (trimethylol ethane, trimethylol propane, trimethylol butane, etc.) and their 2- to 8-mer, pentaerythritol and their 2- to 4-mer, 1, 2, 4 -Butanetriol, 1,3,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,4-butanetetrol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol, mannitol Polyhydric alcohols such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, etc., and mixtures thereof Etc., and the like.

  Examples of the ether include polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether and the like.

  Examples of the hydrocarbon oil include poly α-olefin or a hydride thereof, isobutene oligomer or a hydride thereof, isoparaffin, alkylbenzene, alkylnaphthalene, and the like.

  These synthetic oils may be used individually by 1 type, and may be used combining 2 or more types by arbitrary ratios.

  Among the above, the lubricating base oil is preferably at least one selected from the group consisting of mineral oils and esters.

Kinematic viscosity at 40 ° C. of the lubricating base oil, the oil film component becomes sufficient, more excellent lubricity, in view of evaporation loss under high temperature conditions becomes smaller, preferably 20 mm 2 / ^s or more, more preferably 25 mm ² / S or more, more preferably 30 mm ² / s or more. The kinematic viscosity at 40 ° C. of the lubricating base oil is preferably 100 mm ² / s or less, more preferably 80 mm ² / s or less, and still more preferably 60 mm ² from the viewpoint of improving low-temperature viscosity characteristics and further improving fuel economy. / S or less.

Kinematic viscosity at 100 ° C. of the lubricating base oil, oil film formation becomes sufficient, more excellent lubricity, in view of evaporation loss under high temperature conditions becomes smaller, preferably 5 mm 2 / ^s or more, more preferably 6 mm ² / S or more, more preferably 7 mm ² / s or more. The kinematic viscosity at 100 ° C. of the lubricating base oil is preferably 20 mm ² / s or less, more preferably 15 mm ² / s or less, and still more preferably 10 mm ² from the viewpoint of improving low temperature viscosity characteristics and further improving fuel economy. / S or less.

  The kinematic viscosity in the present invention means a kinematic viscosity measured according to JIS K2283: 2000.

  The content of the lubricating base oil may be, for example, 50% by mass or more, 70% by mass or more, or 90% by mass or more based on the total amount of the lubricating oil composition.

  The content of the additive composition for lubricating oil in the lubricating oil composition may be, for example, 50% by mass or less, 30% by mass or less, 10% by mass or less, 5% by mass or less, or 1% by mass or less. It may be 0.01 mass% or more, 0.1 mass% or more, or 0.3 mass% or more.

  The content of the compound represented by the general formula (1) in the lubricating oil composition is based on the total amount of the lubricating oil composition from the viewpoint of sufficiently improving the wear prevention effect and the oily effect, and further preventing corrosion wear. The amount is preferably 0.05% by mass or more, more preferably 0.3% by mass or more, and still more preferably 0.5% by mass or more. The content of the compound represented by the general formula (1) is preferably 1 from the viewpoint of sufficiently securing the extreme pressure effect by the extreme pressure agent while sufficiently preventing the corrosion wear on the basis of the total amount of the lubricating oil composition. It is 0.0 mass% or less, More preferably, it is 0.9 mass% or less, More preferably, it is 0.8 mass% or less. When the lubricating oil composition contains two or more compounds represented by the general formula (1), the above content is the total content of the two or more compounds.

  In the lubricating oil composition, the content of the extreme pressure agent is preferably 0.001% by mass or more, more preferably 0.005% by mass from the viewpoint of sufficiently exerting extreme pressure properties based on the total amount of the lubricating oil composition. As mentioned above, More preferably, it is 0.01 mass% or more. The content of the extreme pressure agent is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and still more preferably 0.1% by mass from the viewpoint of long-term stability, based on the total amount of the lubricating oil composition. % Or less. When the lubricating oil composition contains two or more of the extreme pressure agents described above, the content is the sum of the contents of the two or more extreme pressure agents.

Kinematic viscosity at 40 ° C. of the lubricating oil composition, oil film formation becomes sufficient, more excellent lubricity, in view of evaporation loss under high temperature conditions becomes smaller, preferably 20 mm 2 / ^s or more, more preferably 25 mm ² / S or more, more preferably 30 mm ² / s or more. The kinematic viscosity at 40 ° C. of the lubricating oil composition is preferably 100 mm ² / s or less, more preferably 80 mm ² / s or less, and still more preferably 60 mm ² from the viewpoint of improving low-temperature viscosity characteristics and further improving fuel economy. / S or less.

Kinematic viscosity at 100 ° C. of the lubricating oil composition, oil film formation becomes sufficient, more excellent lubricity, in view of evaporation loss under high temperature conditions becomes smaller, preferably 5 mm 2 / ^s or more, more preferably 6 mm ² / S or more, more preferably 7 mm ² / s or more. The kinematic viscosity at 100 ° C. of the lubricating oil composition is preferably 20 mm ² / s or less, more preferably 15 mm ² / s or less, and still more preferably 10 mm ² from the viewpoint of improving low-temperature viscosity characteristics and further improving fuel economy. / S or less.

  The phosphorus content in the lubricating oil composition is preferably 1000 ppm by mass or less, more preferably 800 ppm by mass or less, and even more preferably 600 ppm by mass or less, based on the total amount of the lubricating oil composition. The lower limit of the phosphorus content in the lubricating oil composition is not particularly limited, and is, for example, 100 mass ppm or more, or 300 mass ppm or more, based on the total amount of the lubricating oil composition. The “phosphorus content” in the present invention means the content measured by ICP elemental analysis.

  The lubricating oil additive composition and the lubricating oil composition containing the lubricating oil additive composition according to the present embodiment can be widely used in the lubricating oil field. The lubricating oil composition is preferably used as a drive system lubricating oil such as engine oil, automatic transmission or manual transmission, hydraulic hydraulic oil, turbine oil, compressor oil, etc., and particularly preferably used as hydraulic hydraulic oil. .

  The lubricating oil additive composition and the lubricating oil composition according to this embodiment have been described above, but the present invention is not limited to these embodiments. For example, the above-described additive composition for lubricating oil and lubricating oil composition may further contain other additives as long as the effects of the present invention are not significantly impaired. Other additives include, for example, load-resistant additives such as extreme pressure agents, antiwear agents, oiliness agents (friction modifiers) (however, antiwear agents and extreme pressures represented by the above general formula (1)) Cleaning agents, antioxidants, metal deactivators, viscosity index improvers, antifoaming agents, pour point depressants, corrosion inhibitors, rust inhibitors, demulsifiers and the like.

  The content of the load-bearing additive is 1.0 mass based on the total amount of the lubricating oil composition from the viewpoint of ensuring long-term stability of the lubricating oil composition, particularly when the lubricating oil composition is used as a hydraulic fluid. % Or less, more preferably 0.5% by mass or less, still more preferably 0.3% by mass or less, and particularly preferably not substantially contained.

  In addition, when the lubricating oil composition is used as a hydraulic fluid, the content of the detergent dispersant is preferably 5. 5% based on the total amount of the hydraulic fluid composition from the viewpoint of ensuring the demulsibility of the lubricating oil composition. It is preferably 0% by mass or less, more preferably 3.0% by mass or less, still more preferably 1.0% by mass or less, and particularly preferably not substantially contained.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to a following example.

(Lubricant base oil)
The following base oil A1 was used as the lubricating base oil.

A1: Mineral oil (Group III, kinematic viscosity at 40 ° C .: 31.3 mm ² / s)

(Additive)
The following B1 to B4 were used as wear inhibitors.

B1: Dimethylstearylphosphonate represented by the following formula (1-1) (DMSP, Mw: 362, phosphorus content: 8.56% by mass)

B2: Diethyl stearyl phosphonate represented by the following formula (1-2) (DESP, Mw: 390, phosphorus content: 7.94% by mass)

B3: Ethyl stearyl phosphonate represented by the following formula (1-3) (ESP, Mw: 362, phosphorus content: 8.56% by mass)

B4: tricresyl phosphate (TCP, phosphorus content: 8.4% by mass)

  A method for synthesizing the antiwear agents B1 to B3 will be described below.

(Synthesis of antiwear agent B1)
1-dodecene (38 g, 0.226 mol) and dimethyl hydrogen phosphite (79.7 g, 0.69 mol) are collected in a vessel equipped with a stirrer, condenser and nitrogen sparger, and nitrogen is dispersed while stirring. Di-t-butyl peroxide (3 ml) was added. This mixture was stirred at room temperature for 10 minutes and then reacted at about 130 ° C. for 2 hours to obtain an antiwear agent B1 (dimethylstearylphosphonate represented by the formula (1-1)).

(Synthesis of antiwear agent B2)
The antiwear agent B2 is the same as the antiwear agent B1, except that diethyl hydrogen phosphite (100 g, 0.69 mol) is used instead of dimethyl hydrogen phosphite (79.7 g, 0.69 mol). (Diethyl stearyl phosphonate represented by the formula (1-2)) was obtained.

(Synthesis of antiwear agent B3)
Wear prevention similar to the antiwear agent B1, except that ethyl hydrogen phosphite (79.7 g, 0.69 mol) was used instead of dimethyl hydrogen phosphite (79.7 g, 0.69 mol) Agent B3 (ethyl stearyl phosphonate represented by formula (1-3)) was obtained.

  The following C1 to C2 were used as extreme pressure agents.

C1: Extreme pressure agent represented by the following (2-1) (2EH-MDTP-M, Mw: 484, phosphorus content: 6.4% by mass)

C2: Extreme pressure agent represented by the following (2-2) (DTP, 3- (di-isobutoxy-thiophosphorylsulfanyl) -2-methyl-propionic acid, trade name: IRGALUBE353, manufactured by BASF)

  Using the base oil A1, the antiwear agents B1 to B4 and the extreme pressure agents C1 to C2, lubricating oil compositions (based on the total amount of the lubricating oil composition, mass%) having the compositions shown in Tables 1 and 2 were prepared.

(Evaluation of wear prevention effect)
Under the conditions shown below, a four-ball test (ASTM D 4172) was performed, and the wear scar diameter (mm) was measured to evaluate the wear prevention effect. It can be said that the smaller the wear scar diameter, the better the wear prevention effect, that is, the corrosion wear due to the sulfur-based extreme pressure agent could be prevented. The results are shown in Tables 1 and 2.
Load: 392N
Rotation speed: 1200rpm
Temperature: 75 ° C
Test time: 1 hour

(Evaluation of oily effect)
The friction coefficient (μ) of the lubricating oil compositions of Examples 1 to 4 was measured under the following conditions using a block-on-ring test machine (LFW-1) described in ASTM D 2174, and the oiliness of the lubricating oil composition was measured. The effect was evaluated. The results are shown in Table 3. In this test, the smaller the friction coefficient, the better the oily effect.
Test piece (ring): Falex S-10 Test Ring (SAE 4620 Steel)
Test piece (block): Falex H-60 Test Block (SAE01 Steel)
Oil temperature: 60 ° C
Load: 150N

  The test was carried out for 30 minutes at a peripheral speed (sliding speed) of 1 m / s, then the peripheral speed was reduced to 0.05 m / s, and the coefficient of friction for 5 minutes in the peripheral speed region was measured.

(Evaluation of extreme pressure)
Based on ASTM D2783, the load (WL) at 1800 revolutions when the lubricating oil compositions of Examples 1 to 4 were used was measured using a high-speed four-ball tester. The results are shown in Table 3. In addition, it means that it is excellent in extreme pressure property, so that a load is large.

Claims (2)

An antiwear agent represented by the following general formula (1):
A compound represented by the following general formula (2), an acid anhydride of the compound represented by the following general formula (2), and an aliphatic mono group on at least one carboxyl group of the compound represented by the following general formula (2) At least one extreme pressure agent selected from the group consisting of adducts added with alcohol, alkylene glycol or dialkylene glycol;
A lubricating oil additive composition comprising:

[In Formula (1), R ¹ represents a monovalent hydrocarbon group, and R ² and R ³ each independently represent a hydrogen atom or an alkyl group. ]

[In Formula (2), R ⁴ and R ⁵ each independently represent a monovalent hydrocarbon group, R ⁶ represents a hydrogen atom or a carboxyl group, and R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group. X ¹ represents a sulfur atom or an oxygen atom. ]   A lubricating oil composition comprising a lubricating base oil and the additive composition for lubricating oil according to claim 1.