JP2018095814A - Lubricating oil composition for sliding surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating oil composition for a sliding surface, exhibiting both excellent sliding characteristics and excellent water-draining and -separating properties.SOLUTION: This invention relates to a lubricating oil composition for a sliding surface, comprising: (A) a lubricant base oil containing a group-II base oil; (B) at least one selected from the group consisting of sulfurized grease and olefin sulfide; (C) at least one selected from the group consisting of phosphoric ester and amine salt thereof; and (D) at least one selected from the group consisting of polyalkylene glycol and derivative thereof. A mass ratio [P/S] of a phosphorus atom content (P) in the lubricating oil composition and a sulfur atom content (S) in the lubricating oil composition is 0.0040 or more and 0.0150 or less.SELECTED DRAWING: None

Description

  The present invention relates to a sliding surface lubricating oil composition, a method for producing the sliding surface lubricating oil composition, and a machine tool.

A machine tool has a sliding surface for moving a tool, a work material or the like in an arbitrary direction, and a sliding guide surface is mainly used as a sliding surface. Smooth sliding movement of the sliding guide surface greatly contributes to improving the production efficiency of machine tools, reducing product defects by improving machining accuracy, reducing machine tool failures and extending the service life.
In order to perform the sliding motion smoothly, lubricating oil for lubricating the sliding surface (hereinafter also referred to as “sliding surface lubricating oil”) is used.
In addition, during processing such as cutting and grinding, a water-soluble processing oil may be used as the processing oil in addition to the sliding surface lubricating oil. Since water-soluble processing oil is repeatedly used while being circulated, the sliding surface is used for processing oil repeatedly after being used in machining using a machine tool and mixed with lubricating oil for the sliding surface. A process for separating the lubricating oil from the water-soluble processing oil is required. In this case, if the sliding surface lubricating oil remains mixed in the water-soluble processing oil, the water-soluble processing oil is deteriorated, the processing performance of the water-soluble processing oil is lowered, and the decay proceeds. Therefore, when the sliding surface lubricating oil is mixed in the water-soluble processing oil, the sliding surface lubricating oil has excellent performance (hereinafter also referred to as “water draining separation performance”) that can be quickly separated from the water-soluble processing oil. Is required.
For example, Patent Document 1 describes a lubricating oil composition for sliding surfaces, which is obtained by blending a lubricating base oil with a sulfur-based extreme pressure agent, a phosphate ester or an amine salt thereof, and a polyalkylene glycol derivative. ing.
Further, for example, Patent Document 2 discloses at least one base oil selected from mineral oils, fats and oils, at least one selected from phosphorus compounds and sulfur compounds, and a polyalkylene glycol derivative having a specific structure; A lubricating oil composition for a sliding guide surface, characterized in that it contains

Japanese Patent Application Laid-Open No. 10-53783 JP 2004-182790 A

As described above, the sliding surface lubricating oil is required to have excellent draining performance while maintaining excellent sliding characteristics. However, when the sliding surface lubricating oil improves the sliding characteristics, on the other hand, the drainage separation performance tends to deteriorate, and it is difficult to achieve both the sliding characteristics and the drainage separation performance.
In particular, in recent years, there has been an increase in the machining of high-load work materials and / or tools by moving from low speed to high speed, and further improvement in sliding characteristics has been demanded. From the viewpoint of achieving both excellent draining performance, there is room for improvement in the lubricating oil for sliding surfaces.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lubricating oil composition for a sliding surface capable of achieving both excellent sliding characteristics and excellent draining performance. It is.

As a result of intensive studies, the inventors of the present invention are a lubricating oil composition for a sliding surface including a specific lubricating base oil that is the component (A) and specific components (B) to (D), For a sliding surface where the mass ratio [P / S] of the sulfur atom content (S) in the lubricating oil composition and the phosphorus atom content (P) in the lubricating oil composition satisfies a specific range It has been found that a lubricating oil composition can solve the above problems. The present invention has been completed based on such findings. That is, according to each embodiment of the present invention, the following [1] to [3] are provided.
[1] (A): a lubricating base oil containing a Group II base oil;
(B): one or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins;
(C): one or more selected from the group consisting of phosphate esters and amine salts thereof;
(D): A sliding surface lubricating oil composition comprising at least one selected from the group consisting of polyalkylene glycols and derivatives thereof,
The ratio [(P) / (S)] of the sulfur atom content (S) in the lubricating oil composition to the phosphorus atom content (P) in the lubricating oil composition is 0.0040 or more and 0 by mass. A lubricating oil composition for a sliding surface, which is 0.150 or less.
[2] A method for producing a lubricating oil composition for a sliding surface,
The ratio [(P) / (S)] of the sulfur atom content (S) in the lubricating oil composition to the phosphorus atom content (P) in the lubricating oil composition is 0.0040 or more and 0 by mass. .0150 or less,
(A): a lubricating base oil containing a Group II base oil,
(B): one or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins;
(C): one or more selected from the group consisting of phosphate esters and amine salts thereof;
(D): A method for producing a lubricating oil composition for sliding surfaces, wherein a lubricating oil composition is obtained by blending at least one selected from the group consisting of polyalkylene glycol and derivatives thereof.
[3] A machine tool using the sliding surface lubricating oil composition and the water-soluble processing oil according to [1].

  It is possible to provide a lubricating oil composition for a sliding surface that can achieve both excellent sliding characteristics and excellent draining performance.

Hereinafter, the present invention will be described using embodiments.
[Lubricating oil composition for sliding surface]
A lubricating oil composition for a sliding surface according to an embodiment of the present invention (hereinafter, also simply referred to as “lubricating oil composition”) includes a lubricating base oil containing a Group II base oil as a component (A), a component (B) one or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins, component (C) one or more selected from the group consisting of phosphate esters and amine salts thereof, and polyalkylene glycol as component (D) And one or more selected from the group consisting of derivatives thereof. And the ratio [(P) / (S)] of the sulfur atom content (S) in the lubricating oil composition and the phosphorus atom content (P) in the lubricating oil composition is 0 in mass ratio. 0040 to 0.0150.
When the ratio [(P) / (S)] satisfies the range, the lubricating oil composition can achieve both excellent sliding characteristics and excellent draining performance. From such a viewpoint, the ratio [(P) / (S)] is a mass ratio, preferably 0.0045 or more, more preferably 0.0050 or more, and preferably 0.0100 or less. .
The ratio [(P) / (S)] is mainly the ratio of the group II base oil and other base oils contained in the component (A) described later, and the content and components of the component (B). It can adjust with content of (C). Moreover, when the other additive which may be added as needed contains a sulfur atom and a phosphorus atom, the ratio [(P) / (S)] is also affected.
Hereinafter, each component contained in the lubricating oil composition for sliding surfaces will be described.

<Component (A): Lubricating base oil including Group II base oil>
The lubricating oil composition contains a lubricating base oil containing a Group II base oil (hereinafter, also simply referred to as “component (A)”) as component (A). The Group II base oil is a mineral oil classified as Group II in the API (American Petroleum Institute) base oil category.
In the component (A), the content of the group II base oil is preferably 30% by mass or more based on the total amount of the component (A) from the viewpoint that both excellent sliding characteristics and excellent draining performance can be achieved. More preferably, it is 50 mass% or more, and preferably 100 mass% or less.

Component (A) may also contain other base oils in addition to Group II base oils. Other base oils may include, for example, Group I base oils. The Group I base oils are mineral oils classified as Group I in the API (American Petroleum Institute) base oil category.
When component (A) contains a Group I base oil, the ratio of the content of Group I base oil to the content of Group II base oil in Component (A) [(Gr.I) / (Gr. II)] is preferably 0.01 to 2.30 in terms of mass ratio.
When the lubricating oil composition satisfies the ratio, it becomes easier to achieve both excellent sliding characteristics and excellent draining performance. From such a viewpoint, the ratio [(Gr.I) / (Gr.II)] is a mass ratio, more preferably 0.30 or more, still more preferably 1.00 or more, and more preferably 2.00 or less.

  When component (A) also contains a Group I base oil, the total content of Group II and Group I base oils in Component (A) is a lubrication capable of achieving both excellent sliding characteristics and excellent draining performance. From the viewpoint of easily obtaining the oil composition, the total amount of component (A) is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and still more preferably 90% by mass or more. Yes, and preferably 100% by mass or less.

The mineral oil may be, for example, a lubricating oil fraction obtained by atmospheric distillation of paraffinic, intermediate group, or naphthenic crude oil, or by vacuum distillation of atmospheric residual oil obtained by atmospheric distillation of crude oil. Mineralized oil and mineral oil wax are isomerized by performing one or more of solvent removal, solvent extraction, solvent dewaxing, catalytic dewaxing, hydrocracking, hydrorefining, etc. Or oil produced by isomerizing GTL WAX (gas-triwax wax) produced by Fischer-Tropsch process or the like.
Component (A) includes Group II mineral oils among these mineral oils, as described above. Group II mineral oil is produced by a process based on hydrotreating (hydrocracking) among the above-mentioned treatments, so it becomes a mineral oil with low sulfur content, low aromatic hydrocarbon content and high saturation content. .

  Moreover, a component (A) may also contain a synthetic oil as a said other base oil in the range which does not inhibit the effect of this invention. Examples of the synthetic oil include poly α-olefins such as polybutene, α-olefin homopolymers and copolymers (for example, ethylene-α-olefin copolymers); polyol esters, dibasic acid esters, phosphate esters, and the like. Various esters; various ethers such as polyphenyl ether; polyglycol; alkylbenzene; alkylnaphthalene and the like.

The component (A) has a kinematic viscosity at 40 ° C. of preferably 10 mm ² / s to 220 mm ² / s. The 40 ° C. kinematic viscosity is preferably 220 mm ² / s or less, for example, from the viewpoint of improving the sliding characteristics in the obtained lubricating oil or at a high sliding speed. Further, the 40 ° C. kinematic viscosity is preferably 10 mm ² / s or more, for example, from the viewpoint of further reducing the friction coefficient at a low sliding speed of the obtained lubricating oil.
From such a viewpoint, the 40 ° C. kinematic viscosity of the component (A) is more preferably 30 mm ² / s or more, further preferably 40 mm ² / s or more, still more preferably 50 mm ² / s or more, and still more preferably 60 mm. ² / s or more, and more preferably 150 mm ² / s or less, still more preferably 100 mm ² / s or less, still more preferably 80 mm ² / s or less, and still more preferably 75 mm ² / s or less.

Component (A) has a viscosity index (VI) of preferably 80 or more and 120 or less. If the said viscosity index is 80 or more, the viscosity change by the change of temperature will become small. In addition, when the viscosity index of the component (A) is within this range, it becomes easier to obtain appropriate viscosity characteristics as the sliding surface lubricating oil composition.
From such a viewpoint, the viscosity index (VI) of the component (A) is more preferably 85 or more, and still more preferably 90 or more.
In addition, the value of the 40 ° C. kinematic viscosity and the viscosity index (VI) are values measured using the method described in Examples described later.

For example, when a Gr. II base oil is used as the component (A), a sulfur content of 300 mass ppm or less is preferably used. The sulfur content is a value measured using the method described in Examples described later. If it is a component (A) whose sulfur content is 300 mass ppm or less, it is preferable from the viewpoint that the obtained lubricating oil composition may have better thermal stability.
From such a viewpoint, in the component (A), the sulfur content is more preferably 200 ppm by mass or less, still more preferably 100 ppm by mass or less, and still more preferably 50 ppm by mass or less.

The component (A) preferably has an aromatic content (% C _A ) of 3.0 or less by ring analysis. Here, the% C _A by ring analysis shows a proportion of aromatic content calculated by ring analysis n-d-M method (percentage).
If the% C _A is 3.0 or less, preferably it is possible to have better oxidative stability. From this point of view, the% _{C A} of Component (A), more preferably 1.0 or less, more preferably 0.5 or less.
In addition, the component (A) has a paraffin content (% C _P ) by ring analysis of preferably 60 or more, more preferably 65 or more. Setting the paraffin content to 60 or more is preferable because the oxidation stability of the component (A) is improved. Here, the% C _P by ring analysis shows a proportion of paraffin component calculated in ring analysis n-d-M method (percentage).

The lubricating oil composition preferably contains the component (A) as a main component. Here, the phrase “the lubricating oil composition contains the component (A) as a main component” means that the component (A) is contained in a proportion of 50% by mass or more based on the total amount of the lubricating oil composition. The content of the component (A) is more preferably 75% by mass or more, more preferably 80% by mass or more, and still more preferably 85% by mass or more, based on the total amount of the lubricating oil composition (100% by mass). More preferably, it is 90 mass% or more, and preferably 99 mass% or less, More preferably, 98 mass% or less, More preferably, 97 mass% or less.
Component (A) may be a single Group II base oil, or a combination of two or more Group II base oils. One or more Group II base oils may be used. And one or more other base oils may be used in combination. In the case where two or more Group II base oils are used as the component (A), or when the Group II base oil and other base oils are used in combination, the content of the component (A) is the component (A ) Represents the total content.

<Component (B): One or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins>
The lubricating oil composition further contains, as component (B), one or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins (hereinafter also simply referred to as “component (B)”).
By containing the component (B), a lubricating oil composition having excellent sliding properties can be obtained.

  Examples of sulfurized oils and fats include sulfides of animal and vegetable oils or synthetic oils. Examples of the sulfide of animal and vegetable oils include sulfurized lard, sulfurized rapeseed oil, sulfurized castor oil, sulfurized soybean oil, and sulfurized rice bran oil. Examples of the sulfide of synthetic oil include disulfide fatty acids such as sulfurized oleic acid; sulfurized esters such as methyl sulfide oleate; and the like.

  As the sulfurized olefin, for example, a compound represented by the following general formula (1b) is used.

In general formula (1b), R ^1b represents an alkenyl group having 2 to 20 carbon atoms. R ^2b represents an alkyl group having 3 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms. x represents an integer of 1 to 10. Moreover, the alkyl group and alkenyl group in R ^1b and R ^2b may be either linear or branched.
In the general formula (1b), the carbon number of R ^{1b and} the carbon number of R ^2b are each independently preferably 2 to 18 carbon atoms, more preferably 2 to 15 carbon atoms, and x is preferably 1 It is 8 or less, more preferably 1 or more and 7 or less.
The sulfurized olefin was obtained by reacting an olefin having 2 to 20 carbon atoms or a dimer, trimer or tetramer thereof with a sulfur halide such as sulfur chloride or a sulfurizing agent such as sulfur. Things. As the olefin, for example, propylene, isobutene, diisobutene and the like are preferable.
From the viewpoint of improving the wear resistance of the resulting lubricating oil composition, it is preferable to use sulfurized fats and oils.

The content of the component (B) is preferably 0.1% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition (100% by mass). When the lubricating oil composition contains the component (B) in an amount of 0.1% by mass or more, it becomes easier to obtain an effect of improving the sliding characteristics due to a synergistic effect with the component (C) described later. Moreover, the effect corresponding to content can be acquired as this content of a component (B) is 10 mass% or less.
From such a viewpoint, the content of the component (B) is more preferably 0.5% by mass or more, still more preferably 1.0% by mass or more, more than the total amount (100% by mass) of the lubricating oil composition. More preferably, it is 1.5 mass% or more, More preferably, it is 2.0 mass% or more, More preferably, it is 2.5 mass% or more, More preferably, it is 8.0 mass% or less, More preferably, it is 7 It is 0.0 mass% or less, More preferably, it is 5.0 mass% or less, More preferably, it is 4.0 mass% or less.
In addition, a component (B) may be used individually by 1 type, and may be used in combination of 2 or more type. When using 2 or more types of components (B) together, content of this component (B) represents the total content of these components (B).

<Component (C): One or more selected from the group consisting of phosphate ester compounds and amine salts thereof>
The lubricating oil composition further contains, as component (C), one or more selected from the group consisting of phosphate ester compounds and amine salts thereof (hereinafter also simply referred to as “component (C)”). By containing the component (C), a lubricating oil composition having excellent sliding characteristics can be obtained due to a synergistic effect with the component (B).

  Examples of the phosphate ester compound include a phosphate ester represented by the following general formula (1c), an acidic phosphate ester represented by the following general formula (2c) or (3c), and the following general formula: Examples thereof include phosphites represented by (4c) and acidic phosphites represented by the following general formulas (5c) to (7c).

In general formulas (1c) to (7c), R ^{1c to} R ^3c are each independently a hydrocarbon group having 2 to 30 carbon atoms, preferably a hydrocarbon group having 4 to 24 carbon atoms, more preferably carbon. A hydrocarbon group of several 10 to 18 is shown.
Examples of the hydrocarbon group include an alkyl group having 2 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an aralkyl group having 7 to 30 carbon atoms. It is done.

Examples of the alkyl group include an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, and various undecyl groups. , Various dodecyl groups, various tridecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various heptadecyl groups, various octadecyl groups, various nonadecyl groups, various icosyl groups, various heicosyl groups, various docosyl groups, various tricosyl groups, various Examples include a tetracosyl group, various pentacosyl groups, various hexacosyl groups, various heptacosyl groups, various octacosyl groups, various nonacosyl groups, and triacontyl groups.
Here, the description of “various... Group (“ ... ”includes a substituent name.”) Includes linear, branched, cyclic, and isomers thereof (for example, “various butyl groups. "Means an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group and a cyclobutyl group. Hereinafter, the description of “various... Groups” in the present specification is the same unless otherwise specified.

  Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, various butenyl groups, various pentenyl groups, various hexenyl groups, various heptenyl groups, various octenyl groups, various nonenyl groups, various decenyl groups, various undecenyl groups, and various types. Dodecenyl group, various tridecenyl groups, various tetradecenyl groups, various pentadecenyl groups, various hexadecenyl groups, various heptadecenyl groups, various octadecenyl groups, various nonadecenyl groups, various icosenyl groups, various heicosenyl groups, various dococenyl groups, various tricocenyl groups, various tetracocenyl groups , Various pentacocenyl groups, various hexacocenyl groups, various heptacocenyl groups, various octacocenyl groups, various nonacosenyl groups, and triaconenyl groups.

Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group.
Examples of the aralkyl group include benzyl group, phenethyl group, propylbenzyl group, butylbenzyl group, hexylbenzyl group, naphthylmethyl group, methylbenzyl group, methylphenethyl group, and methylnaphthyl group.

  Examples of the phosphate represented by the general formula (1c) include triphenyl phosphate, tricresyl phosphate, benzyl diphenyl phosphate, ethyl diphenyl phosphate, tributyl phosphate, ethyl dibutyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate. , Ethyl phenyl diphenyl phosphate, diethyl phenyl phenyl phosphate, propyl phenyl diphenyl phosphate, dipropyl phenyl phenyl phosphate, triethyl phenyl phosphate, tripropyl phenyl phosphate, butyl phenyl diphenyl phosphate, dibutyl phenyl phenyl phosphate, tributyl phenyl phosphate, trihexyl phosphate, tri (2-ethylhexyl Phosphate, tridecyl phosphate, trilauryl phosphate, trimyristyl phosphate, tri palmityl phosphate, tristearyl phosphate, and trioleyl phosphate and the like.

  Examples of the acidic phosphate represented by the general formula (2c) or (3c) include monoethyl acid phosphate, mono n-propyl acid phosphate, mono 2-ethylhexyl acid phosphate, monobutyl acid phosphate, monooleyl acid phosphate. , Monotetracosyl acid phosphate, monoisodecyl acid phosphate, monolauryl acid phosphate, monotridecyl acid phosphate, monostearyl acid phosphate, monoisostearyl acid phosphate, diethyl acid phosphate, di-n-propyl acid phosphate, di n- Butyl acid phosphate, di-2-ethylhexyl acid phosphate, dioleyl acid phosphate, ditetracosyl acid Dohosufeto, diisodecyl acid phosphate, dilauryl acid phosphate, ditridecyl acid phosphate, distearyl acid phosphate include diisostearyl acid phosphate.

  Examples of the phosphite represented by the general formula (4c) include triethyl phosphite, tributyl phosphite, triphenyl phosphite, tricresyl phosphite, tri (nonylphenyl) phosphite, tri (2-ethylhexyl). ) Phosphite, tridecyl phosphite, trilauryl phosphite, triisooctyl phosphite, diphenylisodecyl phosphite, tristearyl phosphite, trioleyl phosphite.

Examples of the acidic phosphite represented by the general formulas (5c) to (7c) include monoethyl hydrogen phosphite, mono n-propyl hydrogen phosphite, mono n-butyl hydrogen phosphite, mono- 2-ethylhexyl hydrogen phosphite, monolauryl hydrogen phosphite, monooleyl hydrogen phosphite, monostearyl hydrogen phosphite, monophenyl hydrogen phosphite, dibutyl hydrogen phosphite, dihexyl hydrogen phosphite, diheptyl hydrogen phosphite , Di-n-octyl hydrogen phosphite, di-2-ethylhexyl hydrogen phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phospha DOO, distearyl hydrogen phosphite, and diphenyl hydrogen phosphite and the like.
Among the phosphoric acid ester compounds, preferably, isodecyl acid phosphate, lauryl acid phosphate, stearyl acid phosphate, oleyl acid phosphate, and more preferably oleyl acid phosphate are used.

Examples of the amine salt of the phosphate ester compound include amine salts formed from the aforementioned phosphate ester compound and an amine.
Examples of the amine include primary amines, secondary amines, tertiary amines, and polyalkylene amines.
Examples of the primary amine, secondary amine, or tertiary amine include amines represented by the following general formula (8c).

In the general formula (8c), R represents a hydrocarbon group having 2 to 30 carbon atoms, preferably a hydrocarbon group having 4 to 24 carbon atoms, more preferably a hydrocarbon group having 14 to 18 carbon atoms. t represents 1, 2 or 3. When t is 2 or 3, a plurality of R may be the same or different.
Examples of the hydrocarbon group having 2 to 30 carbon atoms represented by R in the general formula (8c) include an alkyl group having 2 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, and 6 to 30 carbon atoms. Examples thereof include the following aryl groups, aralkyl groups having 7 to 30 carbon atoms, and hydroxyalkyl groups having 2 to 30 carbon atoms.
As the alkyl group, alkenyl group, aryl group and aralkyl group represented by R in the general formula (8c), the alkyl group, alkenyl group and aryl group according to R ^{1c to} R ^3c in the general formulas (1c) to (7c) And the thing similar to what was demonstrated as an aralkyl group is mentioned.
As the hydroxyalkyl group represented R is in the general formula (8c), for example, at least one of the hydrogen atoms general formula (1c) alkyl group of the ^R 1c ^{to R 3c} in ~ (7c) has The thing substituted by the hydroxy group is mentioned.

Examples of the primary amine include butylamine, pentylamine, hexylamine, cyclohexylamine, octylamine, laurylamine, stearylamine, oleylamine, and benzylamine.
Examples of the secondary amine include dibutylamine, dipentylamine, dihexylamine, dicyclohexylamine, dioctylamine, dilaurylamine, distearylamine, dioleylamine, dibenzylamine, stearyl / monoethanolamine, decyl / monoethanolamine, Examples include hexyl monopropanolamine, benzyl monoethanolamine, phenyl monoethanolamine, and tolyl monopropanol.
Examples of the tertiary amine include tributylamine, tripentylamine, trihexylamine, tricyclohexylamine, trioctylamine, trilaurylamine, tristearylamine, trioleylamine, tribenzylamine, dioleyl monoethanolamine, dilauryl monomono. Propanolamine, dioctyl monoethanolamine, dihexyl monopropanolamine, dibutyl monopropanolamine, oleyl diethanolamine, stearyl dipropanolamine, lauryl diethanolamine, octyl dipropanolamine, butyl diethanolamine, benzyl diethanolamine, phenyl・ Diethanolamine, Tolyl, Dipropanolamine, Xylyl, Diethanolamine, Tri Ethanolamine, tri propanolamine.

  Examples of the polyalkyleneamine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, tetrapropylenepentamine, and hexabutyleneheptamine.

  In addition, it is preferable to use a phosphate ester amine salt as a component (C) from a viewpoint of improving the lubrication characteristic at low speed.

The content of the component (C) is preferably 0.01% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition (100% by mass). When the content of the component (C) is 0.01% by mass or more, a lubricating oil composition having excellent sliding characteristics can be obtained due to a synergistic effect with the component (B). Moreover, the effect corresponding to content can be acquired as this content of a component (C) is 10 mass% or less.
From such a viewpoint, the content of the component (C) is more preferably 0.03% by mass or more, still more preferably 0.05% by mass or more, more preferably with respect to the total amount (100% by mass) of the lubricating oil composition. More preferably, it is 0.10 mass% or more, More preferably, it is 0.15 mass% or more, More preferably, it is 5.0 mass% or less, More preferably, it is 3.0 mass% or less, More preferably, it is 1 It is 0.0 mass% or less, More preferably, it is 0.40 mass% or less, More preferably, it is 0.30 mass% or less, More preferably, it is 0.20 mass% or less.
In addition, a component (C) may be used individually by 1 type, and may be used in combination of 2 or more type. When using 2 or more types of components (C) together, content of this component (C) represents the total content of these components (C).

<Component (D): One or more selected from the group consisting of polyalkylene glycols and derivatives thereof>
The lubricating oil composition further contains, as component (D), one or more selected from the group consisting of polyalkylene glycols and derivatives thereof (hereinafter also simply referred to as “component (D)”).
By containing the component (D), a lubricating oil composition having excellent drainage separation performance can be obtained.

  Component (D) is preferably one or more selected from the group consisting of polyalkylene glycols represented by the following general formula (1d) and derivatives thereof.

In General Formula (1d), R ^1d and R ^2d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an oxyethylene group, and RO has 3 to 6 carbon atoms. An oxyalkylene group is shown. m and n each independently represent an integer of 0 or more and 100 or less, and an integer satisfying 5 ≦ m + n ≦ 100.

Examples of the alkyl group having 1 to 6 carbon atoms that can be R ^1d and R ^2d include an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, and various hexyl groups.
Examples of the oxyalkylene group having 3 to 6 carbon atoms that can be RO include an oxypropylene group, an oxybutylene group, an oxypentylene group, and an oxyhexylene group, preferably an oxypropylene group.
The repeating units (EO) m and (RO) n may be bound as a block body or may be bound as a random body. When binding as a random body, m represents the total number of EO contained in one molecule, and n represents the total number of RO contained in one molecule.
It is preferable that (EO) m and (RO) n which are repeating units are bonded as a block body.
The molecular weight of component (D) is such that the weight average molecular weight is preferably 1,000 or more, more preferably 3,000 or more, still more preferably 5,000 or more, and preferably 20,000 or less, more preferably It is 10,000 or less, more preferably 7,000 or less.
As component (D), in general formula (1d), R ^1d represents a hydrogen atom, R ^2d represents a hydrogen atom, RO represents an oxypropylene group, and m and n each independently represents an integer of 0 to 100. More preferably a block copolymer represented by a general formula showing an integer satisfying 5 ≦ m + n ≦ 100, and the ratio of m to n is m: n = 20: 80 More preferably, the weight average molecular weight is 5,000 or more and 10,000 or less.

  Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyoxyethylene polyoxypropylene glycol.

  Examples of polyalkylene glycol derivatives include polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, polyoxyethylene monoethyl ether, polyoxypropylene monoethyl ether, polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether, polyoxypropylene Ethylene polyoxypropylene monomethyl ether, polyoxyethylene polyoxypropylene monoethyl ether, polyoxyethylene polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene dimethyl ether, polyoxyethylene polyoxypropylene diethyl ether, polyoxyethylene polyoxypropylene di Butyl ether is mentioned.

The content of component (D) is preferably 0.0001% by mass or more and 1.00% by mass or less based on the total amount of the lubricating oil composition (100% by mass). By containing 0.0001% by mass or more of the component (D), a lubricating oil composition having excellent drainage separation performance can be obtained. Moreover, the effect corresponding to content can be acquired as this content of a component (D) is 1.00 mass% or less.
From such a viewpoint, the content of the component (D) is more preferably 0.001% by mass or more, still more preferably 0.005% by mass or more, more than the total amount (100% by mass) of the lubricating oil composition. More preferably, it is 0.008 mass% or more, More preferably, it is 0.01 mass% or more, More preferably, it is 0.40 mass% or less, More preferably, it is 0.10 mass% or less, More preferably, it is 0. 0.05% by mass or less, more preferably 0.03% by mass or less.
In addition, a component (D) may be used individually by 1 type, and may be used in combination of 2 or more type. When using 2 or more types of components (D) together, content of this component (D) represents the total content of these components (D).

<Component (E): Rust preventive>
In addition to the components (A) to (D), the lubricating oil composition preferably further contains a rust inhibitor as the component (E).

Examples of the rust preventive include metal sulfonates, aliphatic amines, petroleum sulfonates, alkylbenzene sulfonates, dinonyl naphthalene sulfonates, organic sulfonic acid metal salts, organic phosphoric acid metal salts, alkenyl succinic acid esters, polyhydric alcohol esters, A succinimide etc. can be mentioned. When the component (A) contains a Group II base oil, it is preferable to use succinimide as the rust inhibitor.
The content of the rust inhibitor is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, still more preferably 0.05% by mass or more, with respect to the total amount of the lubricating oil composition. Preferably, it is 10 mass% or less, More preferably, it is 5 mass% or less, More preferably, it is 3 mass% or less.

<Other additives>
In addition to the components (A) to (D) and the component (E) used as necessary, the lubricating oil composition further comprises an oil agent, an antioxidant, a rust inhibitor, a metal deactivator, You may contain any 1 type (s) or 2 or more types of various additives (other additives), such as a corrosion inhibitor, an extreme pressure agent, a demulsifier other than a component (D), and an antifoamer. When the lubricating oil composition contains other additives, the total content of the other additives is preferably 15% by mass or less, more preferably 5% by mass with respect to the total amount of the lubricating oil composition. Below, and preferably 0% by mass or more.

Examples of the oily agent include aliphatic saturated and unsaturated monocarboxylic acids such as stearic acid and oleic acid; polymerized fatty acids such as dimer acid and hydrogenated dimer acid; hydroxy fatty acids such as ricinoleic acid and 12-hydroxystearic acid; lauryl Aliphatic saturated and unsaturated monoalcohols such as alcohol and oleyl alcohol; aliphatic saturated and unsaturated monoamines such as stearylamine and oleylamine; aliphatic saturated and unsaturated monocarboxylic amides such as lauric acid amide and oleic acid amide; glycerin And a partial ester of a polyhydric alcohol such as sorbitol and an aliphatic saturated or unsaturated monocarboxylic acid;
In addition, when the said component (A) contains the base oil of group II by high content (for example, 100 mass%), the said alcohol component is the above-mentioned component (B)-(E), and component (A) Therefore, the oily agent is preferably included, and oleyl alcohol is more preferable. When the component (A) contains a Group II base oil in a high content (for example, 100% by mass), the content of the alcohol component is preferably 0.01% by mass or more and 1% by mass or less.
These may be used individually by 1 type and may be used in combination of 2 or more type. The content of the oily agent is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 10% by mass or less, more preferably, based on the total amount of the lubricating oil composition. 5% by mass or less.

Examples of the antioxidant include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,2′-methylenebis (4-methyl-6). -Tert-butylphenol) and the like; amines such as alkylated diphenylamine, alkylated-α-naphthylamine, phenyl-α-naphthylamine, N, N′-di-phenyl-p-phenylenediamine; 2,6-di Sulfur-based antioxidants such as -tert-butyl-4- [4,6-bis (octylthio) -1,3,5-triazin-2-ylamino] phenol and dilaurylthiodipropinate.
The content of the antioxidant is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, with respect to the total amount of the lubricating oil composition, from the viewpoints of effects and economy, and Preferably it is 5 mass% or less, More preferably, it is 3 mass% or less.

Examples of the metal deactivator include benzotriazole, benzimidazole, benzothiazole, thiadiazole, and dimercaptothiazole.
The content of the metal deactivator is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, with respect to the total amount of the lubricating oil composition, from the viewpoints of effects and economy. And preferably it is 5 mass% or less, More preferably, it is 3 mass% or less.

Examples of the corrosion inhibitor include amines, alkanolamines, amides, carboxylic acids and the like.
The content of the corrosion inhibitor is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, with respect to the total amount of the lubricating oil composition, from the viewpoint of effect and economy, and Preferably it is 5 mass% or less, More preferably, it is 3 mass% or less.

Examples of extreme pressure agents include phosphorous extreme pressure agents such as phosphoric acid esters, acidic phosphoric acid esters, phosphorous acid esters, acidic phosphorous acid esters and amine salts thereof other than the aforementioned component (C). Examples thereof include trithiophenyl phosphate.
In addition, examples of other extreme pressure agents include metal salts of carboxylic acids. The metal salt of the carboxylic acid here is preferably a carboxylic acid having 3 to 60 carbon atoms, more preferably a metal salt of a fatty acid having 3 to 30 carbon atoms, and still more preferably a metal of a fatty acid having 12 to 30 carbon atoms. Salt. Moreover, the dimer acid of the said fatty acid, trimer acid, and the metal salt of C3-C30 dicarboxylic acid can be mentioned. Among these, a metal salt of a carboxylic acid is preferably a fatty acid having 12 to 30 carbon atoms and a metal salt of a dicarboxylic acid having 3 to 30 carbon atoms. As the metal constituting the metal salt, an alkali metal or an alkaline earth metal is preferable, and an alkali metal is more preferable.

Furthermore, examples of extreme pressure agents other than the above include sulfur-based extreme pressure agents such as dihydrocarbyl polysulfide, thiocarbamates, thioterpenes, and dialkylthiodipropionates.
One of these extreme pressure agents may be used alone, or two or more thereof may be used in combination.
The content of the extreme pressure agent is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and preferably 10% by mass or less, more preferably based on the total amount of the lubricating oil composition. Is 5% by mass or less.

  Examples of the demulsifier other than the component (D) include surfactants such as an anionic surfactant, a cationic surfactant, and a nonionic surfactant. The content of the demulsifier is preferably 0.001% by mass or more and 0.5% by mass or less based on the total amount of the lubricating oil composition.

  Examples of the antifoaming agent include silicone antifoaming agents such as silicone oil, fluorinated silicone antifoaming agents such as fluorosilicone oil, and polyacrylates. The content of the antifoaming agent is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, and preferably 0.5% by mass or less, more preferably based on the total amount of the lubricating oil composition. Is 0.01 mass% or less.

<Characteristics of lubricating oil composition for sliding surface>
The sliding surface lubricating oil composition preferably has a friction coefficient measured using the method described in the examples described later, from the viewpoint of obtaining excellent friction characteristics in a lower sliding speed environment. 100 or less, more preferably 0.990 or less.
In addition, the sliding surface lubricating oil composition has a maximum non-seizure load (LNL) value measured using the method described in the examples described later, and is excellent in a medium speed to high speed sliding speed environment. From the viewpoint of obtaining good sliding characteristics, it is preferably 650 N or more, more preferably 700 N or more, and further preferably 750 N or more.
From the same viewpoint, the sliding surface lubricating oil composition preferably has a fusion load (WL) value measured using the method described in Examples below, preferably 1,500 N or more, more preferably 1,800 N or more, more preferably 1,900 N or more.
From the same viewpoint, the sliding surface lubricating oil composition preferably has a load wear index (LWI) value calculated using the method described in the examples described later, preferably 250 N or more, more preferably 300 N or more. More preferably, it is 330 N or more.

[Production Method of Sliding Surface Lubricating Oil Composition]
The method for producing a sliding surface lubricating oil composition according to an embodiment of the present invention includes a lubricating base oil containing a group II base oil as component (A), at least a sulfurized fat and oil as component (B), and From one or more selected from the group consisting of sulfurized olefins, one or more selected from the group consisting of the phosphate ester and its amine salt as component (C), and polyalkylene glycol and its derivatives as component (D) One or more selected from the group consisting of the ratio of the phosphorus atom content (P) in the lubricating oil composition to the sulfur atom content (S) in the lubricating oil composition [(P) / (S) Are mixed so that the mass ratio is 0.0040 or more and 0.0150 or less, and the manufacturing method of the lubricating oil composition for sliding surfaces is manufactured.
Moreover, in the said manufacturing method, you may mix | blend any 1 type (s) or 2 or more types of a component (E) and another additive other than a component (B)-(D) as needed. Detailed descriptions of the components (A) to (E) and other additives are the same as those described above, and thus the description thereof is omitted.

[Machine Tools]
The sliding surface lubricating oil composition can be suitably used as a sliding surface lubricating oil composition for machine tools. And since the lubricating oil composition for a sliding surface can achieve both excellent sliding characteristics and excellent drainage performance, it is more preferably used for a sliding guide surface of a machine tool that uses the water-soluble machining fluid. be able to. Examples of the water-soluble machining fluid include a water-soluble metal machining fluid, more specifically a water-soluble cutting oil.
Examples of the machine tool using the sliding surface lubricating oil composition of the present invention include an NC (Numerical Control Machine) machine tool, a machining center, a grinding machine, a CNC (Computerized Numerical Control), and a multi-task machine. Can be mentioned.
Examples of the water-soluble processing oil used together with the sliding surface lubricating oil composition include water-soluble cutting oil, water-soluble grinding oil, water-soluble heat treatment oil, and water-soluble rolling oil. Among these, water-soluble cutting oil is preferable.

  Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  In addition, each physical property of each component and the lubricating oil composition for sliding surfaces was calculated | required according to the point shown below.

[Kinematic viscosity]
According to JIS K2283: 2000, the kinematic viscosity at each temperature was measured using a glass capillary viscometer.
[Viscosity index (VI)]
It is a value measured and calculated in accordance with ASTM D2270.
[Ring analysis (% C _A and% C _P )]
Ring analysis n-d-M aromatic calculated in method (aromatic) proportion (percentage)% of fraction _{C A,} shows the percentage of paraffin component (percentage) as the% _{C P,} it was measured according to ASTM D-3238 .
[Sulfur atom content]
Measured according to ASTM D1552.
[Phosphorus content]
It measured based on JPI-5S-38-2003.
[Weight average molecular weight (Mw)]
The weight average molecular weight (Mw) was measured by GPC (gel permeation chromatography).

[Shell Four Ball Test Load Resistance (EP) Test]
In accordance with ASTM D2783-03 (2014), a four-ball tester is used under conditions of a rotation speed of 1,800 revolutions / minute and an oil temperature (room temperature; 25 ± 5 ° C.), maximum non-seizure load (LNL), The contact load (WL) was measured, and the load wear index (LWI) was calculated. The larger these values, the better the load resistance.
[JASO pendulum test: measurement of friction coefficient μ]
The friction coefficient μ was measured at an oil temperature of 80 ° C. using an Iwata-type pendulum tester (II) type in accordance with “Iwata-type pendulum test” defined in JASO-M314-88.
[Evaluation of draining performance]
The draining performance was evaluated according to the demulsibility test method of JIS K2520: 2000. Specifically, at a measurement temperature of 30 ° C., a cylinder containing 40 mL of water-soluble cutting oil diluted 20-fold with pure water and 40 mL of the sliding surface lubricating oil composition is rotated for 5 minutes at 1,500 rpm. The emulsified liquid that has been agitated and mainly contains water and a water-soluble cutting oil (hereinafter also referred to as “water draining layer”) and a layer that mainly includes a sliding surface lubricating oil composition (hereinafter referred to as “oil layer”). The time until separation was measured. As the water-soluble cutting oil, a trade name “Daphney (registered trademark) Alpha Cool EW (stock solution)” manufactured by Idemitsu Kosan Co., Ltd. was used.
From the measurement results, the water scissor separation performance was evaluated with the following ratings. The lower the score, the better the draining separation performance, and the higher the score, the worse the draining separation performance.
1 point: Separated into drainage layer and oil layer in less than 20 minutes.
2 points: Separated into a draining layer and an oil layer in a time of 20 minutes or more and less than 30 minutes.
3 points: Separated into a draining layer and an oil layer in a time of 30 minutes or more and less than 40 minutes.
4 points: Separated into a draining layer and an oil layer in a time of 40 minutes or more and less than 50 minutes.
5 points: Separated into a draining layer and an oil layer in a time of 50 minutes or more.

[Examples 1 to 6 and Comparative Examples 1 to 10]
In the compositions shown in Tables 1 and 2, the components shown in Tables 1 and 2 were blended with the component (A) to prepare lubricating oil compositions for sliding surfaces of Examples and Comparative Examples. According to the said evaluation method, the lubricating oil composition for sliding surfaces of each Example and each comparative example was evaluated. The obtained results are shown in Tables 1 and 2 below.

In addition, each component shown in following Table 1 and 2 represents the following.
<Component (A)>
Group I paraffinic mineral oil [hereinafter also referred to as “Gr. I base oil”. 40 ° C. kinematic viscosity: 68 mm ² / s (ISO VG68), viscosity index (VI): 95 or more, sulfur atom content: 5,300 mass ppm, ndM ring analysis;% C _A 7.0,% C _P 68.9]
Group II paraffinic mineral oil [hereinafter also referred to as “Gr. II base oil”. 40 ° C. kinematic viscosity: 68 mm ² / s (ISO VG68), viscosity index (VI): 100, sulfur content: 7 mass ppm, ndM ring analysis;% C _A 0.0,% C _P 67. 1]
-Base oil used in Example 2 [Gr. I / Gr. II = 25/75 (mass ratio); 40 ° C. kinematic viscosity: 68 mm ² / s (ISO VG68), viscosity index (VI): 113, sulfur content: 1,300 mass ppm, ndM ring analysis; % C _A 1.5,% C _P 69.2]
-Base oil used in Example 3 [Gr. I / Gr. II = 50/50 (mass ratio); 40 ° C. kinematic viscosity: 68 mm ² / s (ISO VG68), viscosity index (VI): 111, sulfur content: 2,700 mass ppm, ndM ring analysis; % C _A 2.9,% C _P 68.9]
-Base oil used in Examples 4 and 5 [Gr. I / Gr. II = 67/33 (mass ratio); 40 ° C. kinematic viscosity: 68 mm ² / s (ISO VG68), viscosity index (VI): 110, sulfur content: 3,600 mass ppm, ndM ring analysis; % C _A 3.9,% C _P 68.7]

<Component (B)>
・ Sulfurized oil (sulfurized lard, sulfur atom content: 11% by mass)

<Ingredient (C)>
Phosphoric ester amine salt [phosphorus compound obtained by reacting oleyl acid phosphate and polyalkyleneamine, phosphorus atom content: 2.20% by mass]
・ Phosphate ester (oleyl acid phosphate, phosphorus atom content: 6.30% by mass)

<Component (D)>
Polyalkylene glycol [In the general formula (1d), R ^1d is hydrogen, R ^2d is hydrogen, RO is an oxypropylene group, m: n = 20: 80, and a weight-average molecular weight is 5,500. (Ethylene / polyoxypropylene block copolymer)

<Component (E) Rust inhibitor>
・ Polybutenyl succinimide

As is apparent from the evaluation results in Tables 1 and 2, the sliding surface lubricating oil compositions of Examples 1 to 6 have a low coefficient of friction μ by the JASO pendulum test, and the results of the load resistance evaluation by the shell four-ball test are also shown. It was confirmed that the sliding property was excellent under the condition of low to high speed. Moreover, the lubricating oil compositions for sliding surfaces of Examples 1 to 6 were also excellent in drainage separation performance, and it was confirmed that both excellent sliding characteristics and excellent drainage separation performance can be achieved.
On the other hand, it was confirmed that the lubricating oil compositions of Comparative Examples 1 to 10 cannot achieve both excellent sliding characteristics and excellent draining performance.

  Since the sliding surface lubricating oil composition can achieve both excellent sliding characteristics and excellent draining performance, for example, for lubricating a sliding surface of a cutting machine used with a water-soluble cutting oil. It can be suitably used as a lubricating oil for sliding surfaces.

Claims (9)

(A): a lubricating base oil containing a Group II base oil;
(B): one or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins;
(C): one or more selected from the group consisting of phosphate ester compounds and amine salts thereof,
(D): A sliding surface lubricating oil composition comprising at least one selected from the group consisting of polyalkylene glycols and derivatives thereof,
The ratio [(P) / (S)] of the sulfur atom content (S) in the lubricating oil composition to the phosphorus atom content (P) in the lubricating oil composition is 0.0040 or more and 0 by mass. A lubricating oil composition for a sliding surface, which is 0.150 or less. The lubricating oil composition for sliding surfaces according to claim 1, wherein the component (D) is at least one selected from the group consisting of polyalkylene glycols represented by the following general formula (1d) and derivatives thereof.

(In General Formula (1d), R ^1d and R ^2d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, EO represents an oxyethylene group, and RO represents 3 to 6 carbon atoms. M and n each independently represents an integer of 0 or more and 100 or less, and an integer satisfying 5 ≦ m + n ≦ 100.   The lubricating oil composition for sliding surfaces according to claim 1 or 2, wherein the content of the group II base oil is 30% by mass or more and 100% by mass or less based on the total amount of component (A). The content of the component (B) is 0.1% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition,
The content of component (C) is 0.01% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition, and
The sliding surface lubricating oil according to any one of claims 1 to 3, wherein the content of the component (D) is 0.0001 mass% or more and 1.00 mass% or less based on the total amount of the lubricating oil composition. Composition.   Component (A) further comprises a Group I base oil, and the ratio of the Group I base oil content to the Group II base oil content in component (A) [(Gr.I) / ( The lubricating oil composition for a sliding surface according to any one of claims 1 to 4, wherein Gr. II)] is 0.01 to 2.30 in terms of mass ratio.   Furthermore, (E) Lubricating oil composition for sliding surfaces of any one of Claims 1-5 containing a rust preventive agent. In the component (D), in general formula (1d), R ^1d represents a hydrogen atom, R ^2d represents a hydrogen atom, RO represents an oxypropylene group, and m and n each independently represents an integer of 0 to 100. And the lubricating oil composition for sliding surfaces of any one of Claims 2-6 which is a block copolymer represented by the general formula which shows the integer which satisfies 5 <= m + n <= 100. A method for producing a lubricating oil composition for a sliding surface,
The ratio [(P) / (S)] of the sulfur atom content (S) in the lubricating oil composition to the phosphorus atom content (P) in the lubricating oil composition is 0.0040 or more and 0 by mass. .0150 or less,
(A): a lubricating base oil containing a Group II base oil,
(B): one or more selected from the group consisting of sulfurized fats and oils and sulfurized olefins;
(C): one or more selected from the group consisting of phosphate ester compounds and amine salts thereof,
(D): A method for producing a lubricating oil composition for sliding surfaces, wherein a lubricating oil composition is obtained by blending at least one selected from the group consisting of polyalkylene glycol and derivatives thereof.   A machine tool using the lubricating oil composition for sliding surfaces and the water-soluble processing oil according to any one of claims 1 to 7.