JP2005060526A - Hydraulic oil composition and operation method for hydraulic operating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a hydraulic oil composition which prevents generation of rust or sludge and deterioration of the hydraulic oil and permits stable operation of a hydraulic operating system even when it is used for the hydraulic operating system of high performances obtained by enhancing speed/precision of a servo valve, or the like, and to provide an operation method for the hydraulic operating system. <P>SOLUTION: The hydraulic oil composition comprises at least one selected from among mineral oils, oil and fat and synthetic oils as a base oil, and incorporated therewith, (A) 0.01-2 mass% of an ashless rust-proofing agent having a total base value of 2-100 mgKOH/g, (B) 0.01-2 mass% of an ashless antioxidant, and (C) 0.005-5 mass% of an ashless wear-preventing agent, and is substantially free from zinc dithiophosphate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydraulic fluid composition and a method for operating a hydraulic operation system.

  Conventionally, lubricating oil has been required as an essential performance for rust prevention. For example, JIS K 2513 stipulates a rust prevention test using distilled water or artificial seawater. However, in the case of hydraulic fluids that are circulated and used, the market is required to pass the rust prevention test. .

Therefore, in order to ensure rust prevention properties, rust preventives such as fatty acids, fatty acid esters, alkenyl succinic acid half esters, aliphatic amines, alkenyl succinimides, polyhydric alcohol esters, petroleum sulfonates, dinonyl naphthalene sulfonic acids are hydraulically used. It is customary to add to hydraulic oil. (For example, refer to page 15 of Patent Document 1)
JP 2000-303086 A

  By the way, what is known as a hydraulic operation system is a system that controls the flow rate and flow direction of hydraulic hydraulic oil by a control valve such as a spool valve or a servo valve. In particular, in a hydraulic machine such as a vibration exciter provided for the purpose of studying the degree of influence of the ground and buildings on an earthquake, a hydraulic operation system including a servo valve is widely used. In such a hydraulic operation system, the performance of the hydraulic machine is further improved by increasing the speed and accuracy of the control valve.

  However, when conventional hydraulic fluids are used in such a high-performance hydraulic system, rust, sludge, and deterioration of the hydraulic fluid occur. As a result, the hydraulic system body and control valve May cause malfunction.

  The present invention has been made in view of the above-described problems of the prior art, and even when used in a hydraulic operation system that has been improved in performance by increasing the speed and precision of spool valves, servo valves, etc., It is an object of the present invention to provide a hydraulic fluid composition capable of stably operating a hydraulic operation system by preventing occurrence of sludge and deterioration of the hydraulic operation oil, and an operation method of the hydraulic operation system.

    As a result of intensive research to achieve the above object, the inventors of the present invention firstly increased the speed and precision of control valves such as spool valves and servo valves. It was found that a large shear stress is applied, and as a result, organic acids such as formic acid and acetic acid are easily generated. The generation of rust and sludge described above is due to the formation of organic acid metal salts, and is considered to be one of the causes of the deterioration of hydraulic fluid.

  In addition, the present inventors have heretofore widely used hydraulic fluids to which zinc dithiophosphate (ZnDTP) has been added for the purpose of improving oxidation stability and wear resistance. It has been found that even when used for a long period of time, sludge is generated due to the generation of water and the thermal degradation of ZnDTP, and this sludge enters the sliding surface of the hydraulic operation system to increase the sliding resistance.

  Conventionally, in order to prevent the generation of rust and sludge, the characteristics of hydraulic fluids have been improved by using an acid-based anti-rust agent such as succinic acid half ester, which is considered to have high anti-rust properties. Although it is considered that the method of raising the standard such as the rust prevention test by artificial seawater prescribed in 2513 is effective, the adoption of such a method is a fundamental solution under the condition that organic acid such as formic acid is generated. It will not be. That is, organic acids such as formic acid have a very strong adsorptive power to metals such as iron, and the acid rust inhibitor adsorbed on the metal surface is easily replaced by organic acids, so that it is very difficult to obtain the desired rust preventive effect. Have difficulty.

Then, in order to solve the said subject, the hydraulic fluid composition of this invention makes base oil at least 1 sort (s) chosen from mineral oil, fats and oils, and the following (A)-(C):
(A) Ashless rust preventive agent having a total base number of 2 to 100 mgKOH / g 0.01 to 2% by mass
(B) Ashless antioxidant 0.01-2 mass%
(C) Ashless antiwear agent 0.005-5 mass%
And is substantially free from zinc dithiophosphate.

Further, the hydraulic fluid composition of the present invention may be used in a hydraulic fluid system having a portion where the shear stress applied to the hydraulic fluid is 10 ³ S ⁻¹ or more.

Further, according to the operation method of the hydraulic operation system of the present invention, when the hydraulic operation system having a portion where the shear stress applied to the hydraulic operation oil is 10 ³ S ⁻¹ or more is operated, A hydraulic oil composition is used.

According to the present invention, by adding specific amounts of the components (A) to (C) to the predetermined base oil and substantially not containing zinc dithiophosphate, the thermal and oxidation stability of the hydraulic fluid composition can be improved. Property, rust prevention, sludge formation prevention and wear resistance are all improved in a well-balanced manner. Therefore, a hydraulic machine having a large load on the hydraulic fluid, such as a hydraulic operation system including a spool valve and a servo valve, particularly, a hydraulic operation having a portion where the shear stress applied to the hydraulic fluid is 10 ³ S ⁻¹ or more. Even when the system is operated, the operation is sufficiently stabilized, so that high performance of the system can be realized.

  In the present invention, “substantially does not contain zinc dithiophosphate” means that the addition effect of zinc dithiophosphate does not appear, and is not particularly limited in numerical values. Means that the content of ZnDTP is 0.001% by mass or less based on the total amount of the composition.

  ADVANTAGE OF THE INVENTION According to this invention, the hydraulic fluid composition which is excellent in all of rust prevention property, thermal / oxidation stability, and abrasion resistance, and the operating method of the hydraulic system using the said hydraulic fluid composition are provided. Therefore, the present invention prevents the generation of rust and sludge and the deterioration of hydraulic fluid even when used in high-performance hydraulic systems such as spool valves and servo valves. It becomes possible to operate the hydraulic operation system stably.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  In the hydraulic fluid composition of the present invention, at least one selected from mineral oil, fats and oils and synthetic oils is used as the base oil.

  As mineral oil, lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil is solvent desorbed, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing Examples thereof include paraffinic or naphthenic mineral oils obtained by appropriately combining and applying one or more purification means such as clay treatment.

  Examples of the fats and oils include beef tallow, lard, sunflower oil, soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, palm kernel oil, and hydrogenated products thereof.

  Synthetic oils include, for example, poly α-olefins (ethylene-propylene copolymer, polybutene, 1-octene oligomer, 1-decene oligomer, and hydrides thereof), alkylbenzene, alkylnaphthalene, monoester (butyl). Stearate, octyl laurate), diester (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sepacate, etc.), polyester (trimellitic acid ester, etc.), polyol ester (Trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glyco Le, polyphenyl ether, dialkyl diphenyl ether, phosphate ester (tricresyl phosphate, etc.), fluorine-containing compound (perfluoropolyether, fluorinated polyolefin and the like), silicone oils and the like.

  In the present invention, one of the aforementioned base oils may be used alone, or two or more may be combined.

Kinematic viscosity of the base oil used in the present invention is not particularly limited, preferably a kinematic viscosity at 40 ° C. is 5 to 500 mm ² / s, more preferably 7~300mm ² / s, 10~ More preferably, it is 200 mm ² / s. When the kinematic viscosity of the base oil is within the above range, characteristics such as friction characteristics and cooling properties (heat removability) are further enhanced, and friction loss due to stirring resistance tends to be reduced.

  The viscosity index of the base oil used in the present invention is also arbitrary, but is preferably 80 to 500, more preferably 100 to 300 from the viewpoint of maintaining an oil film at a high temperature.

  Furthermore, although the pour point of the base oil is also arbitrary, it is preferably −5 ° C. or lower, more preferably −15 ° C. or lower, from the viewpoint of pump startability in winter.

  In the present invention, components (A) to (C) described later are blended with the base oil.

  The component (A) according to the present invention is an ashless rust inhibitor having a total base number of 2 to 100 mgKOH / g. Here, the ashless rust preventive means a rust preventive containing no metal element. By using an ashless rust inhibitor, the thermal and oxidation stability of the hydraulic fluid composition can be further increased.

  (A) The total base number of the ashless anticorrosive agent is required to be 2 mgKOH / g or more in terms of the effect of suppressing the malfunction of control valves and the like caused by iron formate, and 5 mgKOH / G or more is preferable, and 10 mgKOH / g or more is more preferable. Also, from the viewpoint of rust prevention and prevention of sludge formation due to high base components, it is necessary that the amount be 100 mgKOH / g or less, preferably 80 mgKOH / g or less, and 60 mgKOH / g or less. More preferably, it is still more preferably 40 mgKOH / g or less.

  The total base number referred to here is JIS K 2501 “Petroleum products and lubricating oils-Neutralization number test method”. The total base number [mgKOH / g] measured by the hydrochloric acid method according to the above.

As an ashless rust inhibitor used in the present invention,
(A-1) Amine compound (A-2) Amide compound (A-3) Carboxylic acid amine salt and / or sulfonic acid amine salt and the like.

  (A-1) Examples of the amine compound include monoamines, polyamines, alkanolamines, and among these, monoamines are preferable from the viewpoint of the effect of suppressing malfunction of control valves caused by iron formate and the like.

Specific examples of monoamines include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine (including all isomers), dipropylamine (including all isomers), Propylamine (including all isomers), monobutylamine (including all isomers), dibutylamine (including all isomers), tributylamine (including all isomers), monopentylamine (all including all isomers) Including isomers), dipentylamine (including all isomers), tripentylamine (including all isomers), monohexylamine (including all isomers), dihexylamine (including all isomers) ), Monoheptylamine (including all isomers), diheptylamine (including all isomers) ), Monooctylamine (including all isomers), dioctylamine (including all isomers), monononylamine (including all isomers), monodecylamine (including all isomers), monoundecyl (Including all isomers), monododecylamine (including all isomers), monotridecylamine (including all isomers), monotetradecylamine (including all isomers), monopentadecyl Amine (including all isomers), monohexadecylamine (including all isomers), monoheptadecylamine (including all isomers), monooctadecylamine (including all isomers), mononona Decylamine (including all isomers), monoicosylamine (including all isomers), monohenicosylamine (including all isomers), monodocosyl Min (including all isomers), monotricosylamine (including all isomers), dimethyl (ethyl) amine, dimethyl (propyl) amine (including all isomers), dimethyl (butyl) amine (all Isomers), dimethyl (pentyl) amine (including all isomers), dimethyl (hexyl) amine (including all isomers), dimethyl (heptyl) amine (including all isomers), dimethyl ( Octyl) amine (including all isomers), dimethyl (nonyl) amine (including all isomers), dimethyl (decyl) amine (including all isomers), dimethyl (undecyl) amine (all isomers) ), Dimethyl (dodecyl) amine (including all isomers), dimethyl (tridecyl) amine (including all isomers), dimethyl (tetradecyl) ) Amine (including all isomers), dimethyl (pentadecyl) amine (including all isomers), dimethyl (hexadecyl) amine (including all isomers), dimethyl (heptadecyl) amine (all isomers) ), Dimethyl (octadecyl) amine (including all isomers), dimethyl (nonadecyl) amine (including all isomers), dimethyl (icosyl) amine (including all isomers), dimethyl (henicosyl) Alkylamines such as amines (including all isomers), dimethyl (tricosyl) amine (including all isomers);
Monovinylamine, divinylamine, trivinylamine, monopropenylamine (including all isomers), dipropenylamine (including all isomers), tripropenylamine (including all isomers), monobutenylamine (Including all isomers), dibutenylamine (including all isomers), tributenylamine (including all isomers), monopentenylamine (including all isomers), dipentenylamine (all isomers) ), Tripentenylamine (including all isomers), monohexenylamine (including all isomers), dihexenylamine (including all isomers), monoheptenylamine (all isomers) ), Diheptenylamine (including all isomers), monooctenylamine (including all isomers), dioctenylamine (Including all isomers), monononenylamine (including all isomers), monodecenylamine (including all isomers), monoundecenyl (including all isomers), monododecenylamine (Including all isomers), monotridecenylamine (including all isomers), monotetradecenylamine (including all isomers), monopentadecenylamine (including all isomers), Monohexadecenylamine (including all isomers), monoheptadecenylamine (including all isomers), monooctadecenylamine (including all isomers), monononadecenylamine (all isomers) ), Monoicosenylamine (including all isomers), monohenicocenylamine (including all isomers), monodocosenylamine (including all isomers), Trichoderma cell (including all isomers) cycloalkenyl amines alkenyl amines, such as;
Dimethyl (vinyl) amine, dimethyl (propenyl) amine (including all isomers), dimethyl (butenyl) amine (including all isomers), dimethyl (pentenyl) amine (including all isomers), dimethyl ( Hexenyl) amine (including all isomers), dimethyl (heptenyl) amine (including all isomers), dimethyl (octenyl) amine (including all isomers), dimethyl (nonenyl) amine (all isomers) ), Dimethyl (decenyl) amine (including all isomers), dimethyl (undecenyl) amine (including all isomers), dimethyl (dodecenyl) amine (including all isomers), dimethyl (tridecenyl) Amine (including all isomers), dimethyl (tetradecenyl) amine (including all isomers), dimethyl (pen Decenyl) amine (including all isomers), dimethyl (hexadecenyl) amine (including all isomers), dimethyl (heptadecenyl) amine (including all isomers), dimethyl (octadecenyl) amine (all isomers) ), Dimethyl (nonadecenyl) amine (including all isomers), dimethyl (icosenyl) amine (including all isomers), dimethyl (henicosenyl) amine (including all isomers), dimethyl (tricosenyl) Monoamines having alkyl and alkenyl groups such as amines (including all isomers);
Monobenzylamine, (1-phenyltyl) amine, (2-phenylethyl) amine (also known as monophenethylamine), dibenzylamine, bis (1-phenethyl) amine, bis (2-phenylethylene) amine (also known as diphenethylamine) Aromatic substituted alkylamines such as
C5-C16 cycloalkylamines such as monocyclopentylamine, dicyclopentylamine, tricyclopentylamine, monocyclohexylamine, dicyclohexylamine, monocycloheptylamine, dicycloheptylamine;
Monoamines having an alkyl group and a cycloalkyl group, such as dimethyl (cyclopentyl) amine, dimethyl (cyclohexyl) amine, dimethyl (cycloheptyl) amine;
(Methylcyclopentyl) amine (including all substituted isomers), bis (methylcyclopentyl) amine (including all substituted isomers), (dimethylcyclopentyl) amine (including all substituted isomers), bis (dimethylcyclopentyl) ) Amine (including all substituted isomers), (ethylcyclopentyl) amine (including all substituted isomers), bis (ethylcyclopentyl) amine (including all substituted isomers), (methylethylcyclopentyl) amine ( All substituted isomers included), bis (methylethylcyclopentyl) amine (including all substituted isomers), (diethylcyclopentyl) amine (including all substituted isomers), (methylcyclohexyl) amine (all substituted isomers) Isomers), bis (methylcyclohexyl) amine (all substituted isomers) ), (Dimethylcyclohexyl) amine (including all substituted isomers), bis (dimethylcyclohexyl) amine (including all substituted isomers), (ethylcyclohexyl) amine (including all substituted isomers), bis (Ethylcyclohexyl) amine (including all substituted isomers), (Methylethylcyclohexyl) amine (including all substituted isomers), (Diethylcyclohexyl) amine (including all substituted isomers), (Methylcycloheptyl) ) Amine (including all substituted isomers), bis (methylcycloheptyl) amine (including all substituted isomers), (dimethylcycloheptyl) amine (including all substituted isomers), (ethylcycloheptylamine) (Including all substituted isomers), (methylethylcycloheptyl) amine (all substituted isomers) And alkyl cycloalkylamines such as (diethylcycloheptyl) amine (including all substituted isomers), etc. The monoamine also includes monoamines derived from fats and oils such as beef tallow amine. It is.

  Among the above-mentioned monoamines, alkylamines, monoamines having an alkyl group and an alkenyl group, monoamines having an alkyl group and a cycloalkyl group, and cycloalkylamines, in particular, from the viewpoint of the effect of suppressing malfunction of control valves caused by iron formate, In addition, alkylcycloalkylamine is preferable, and monoamine having an alkylamine, an alkyl group, and an alkenyl group is more preferable.

  Although there is no restriction | limiting in particular about carbon number of a monoamine, It is preferable that it is 8 or more from the point of rust prevention property, and it is more preferable that it is 12 or more. Moreover, it is preferable that it is 24 or less from the point of the malfunction suppression effect, such as a control valve resulting from iron formate etc., and it is more preferable that it is 18 or less.

  Furthermore, the number of hydrocarbon groups bonded to the nitrogen atom in the monoamine is not particularly limited, but from the viewpoint of the effect of suppressing the malfunction of control valves and the like caused by iron formate, it is preferably 1 or 2; More preferably, it is one.

  (A-2) As an amide compound, an amine compound containing only a fatty acid having 6 to 30 carbon atoms or its acid chloride, ammonia, a hydrocarbon group having 1 to 8 carbon atoms or a hydroxyl group-containing hydrocarbon group in the molecule, etc. And amides obtained by reacting the nitrogen-containing compounds.

  The fatty acid here may be a linear fatty acid or a branched fatty acid, and may be a saturated fatty acid or an unsaturated fatty acid. The carbon number is 6-30, preferably 9-24.

  Specific examples of the fatty acid include heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, Saturated fatty acids such as icosanoic acid, henicosanoic acid, docosanoic acid, tricosanoic acid, tetracosanoic acid, pentacosanoic acid, hexacosanoic acid, heptacosanoic acid, octacosanoic acid, nonacosanoic acid and triacontyl group (these saturated fatty acids may be linear or branched) ); Heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, octadecenoic acid (including oleic acid), nonadecenoic acid, icosenic acid, Henicosenoic acid Unsaturated fatty acids such as docosenoic acid, tricosenoic acid, tetracosenoic acid, pentacosenoic acid, hexacosenoic acid, heptacosenoic acid, octacosenoic acid, nonacenoic acid, triacontenoic acid (these unsaturated fatty acids may be linear or branched, The position of the heavy bond is also arbitrary); but the linear fatty acids derived from lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, various fats and oils (coconut oil fatty acid etc.) A mixture of linear fatty acid and branched fatty acid synthesized by the oxo method or the like is preferably used.

  Specific examples of the nitrogen-containing compound to be reacted with the fatty acid include ammonia; monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, dimethylamine, Alkylamines such as methylethylamine, diethylamine, methylpropylamine, ethylpropylamine, dipropylamine, methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, etc. May be chain or branched); monomethanolamine, monoethanolamine, monopropanolamine, monobutanolamine, monopentanolamine, monohexene Noramine, monoheptanolamine, monooctanolamine, monononanolamine, dimethanolamine, methanolethanolamine, diethanolamine, methanolpropanolamine, ethanolpropanolamine, dipropanolamine, methanolbutanolamine, ethanolbutanolamine, propanolbutanolamine, di Examples thereof include alkanolamines such as butanolamine, dipentanolamine, dihexanolamine, diheptanolamine and dioctanolamine (the alkanol group may be linear or branched); and mixtures thereof.

  Specific examples of fatty acid amides include lauric acid amide, lauric acid diethanolamide, lauric acid monopropanolamide, myristic acid amide, myristic acid diethanolamide, myristic acid monopropanolamide, palmitic acid amide, palmitic acid diethanolamide, and palmitic acid. Acid monopropanolamide, stearic acid amide, stearic acid diethanolamide, stearic acid monopropanolamide, oleic acid amide, oleic acid diethanolamide, oleic acid monopropanolamide, coconut oil fatty acid amide, coconut oil fatty acid diethanolamide, coconut oil fatty acid mono Propanolamide, C12-13 synthetic mixed fatty acid amide, C12-13 synthetic mixed fatty acid diethanolamide, C12-13 synthetic blend Fatty acid mono-propanol amides, and mixtures thereof are particularly preferred.

  (A-3) Examples of the amine used in the carboxylic acid amine salt and / or sulfonic acid amine salt include the above-described (A-1) amine compound, and more specifically, monoamine, polyamine, alkanolamine, and the like. Among these, polyamine is preferred from the viewpoint of the effect of suppressing malfunction of control valves and the like caused by iron formate and the like.

Specific examples of polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, propylenediamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, pentapropylenehexamine, butylenediamine, diethylene Alkylpolyamines such as butylenetriamine, butylenetetramine, tetrabutylenepentamine, pentabylenehexamine;
N-methylethylenediamine, N-ethylethylenediamine, N-propylethylenediamine (including all isomers), N-butylethylenediamine (including all isomers), N-pentylethylenediamine (including all isomers), N -Hexylethylenediamine (including all isomers), N-heptylethylenediamine (including all isomers), N-octylethylenediamine (including all isomers), N-nonylethylenediamine, N-decylethylenediamine (all Isomers), N-undecylethylenediamine (including all isomers), N-dodecylethylenediamine (including all isomers), N-tridecylethylenediamine (including all isomers), N-tetra Decylethylenediamine (including all isomers), N-pe Tadecylethylenediamine (including all isomers), N-hexadecylethylenediamine, N-heptadecylethylenediamine (including all isomers), N-octadecylethylenediamine (including all isomers), N-nonadecylethylenediamine (Including all isomers), N-icosylethylenediamine (including all isomers), N-henicosylethylenediamine (including all isomers), N-docosylethylenediamine (including all isomers) N-alkylethylenediamine such as N-tricosylethylenediamine (including all isomers);
N-vinylethylenediamine, N-propenylethylenediamine (including all isomers), N-butenylethylenediamine (including all isomers), N-pentenylethylenediamine (including all isomers), N-hexenylethylenediamine ( Including all isomers), N-heptenylethylenediamine (including all isomers), N-octenylethylenediamine (including all isomers), N-nonenylethylenediamine (including all isomers), N-decenylethylenediamine (including all isomers), N-undecenylethylenediamine (including all isomers), N-dodecenylethylenediamine (including all isomers), N-tridece Nylethylenediamine (including all isomers), N-tetradecenylethylenediamine (all isomers) N-pentadecenylethylenediamine (including all isomers), N-hexadecenylethylenediamine (including all isomers), N-heptadecenylethylenediamine (including all isomers) ), N-octadecenylethylenediamine (including all isomers), N-nonadecenylethylenediamine (including all isomers), N-icosenylethylenediamine (including all isomers), N -N-alkenylethylenediamines such as henicosenylethylenediamine (including all isomers), N-docosenylethylenediamine (including all isomers), N-tricosenylethylenediamine (including all isomers), etc. ;
N-alkyldiethylenetriamine, N-alkenyldiethylenetriamine, N-alkyltriethylenetetramine, N-alkenyltriethylenetetramine, N-alkyltetraethylenepentamine, N-alkenyltetraethylenepentamine, N-alkylpentaethylenehexamine, N-alkenyl Pentaethylenehexamine, N-alkylpropylenediamine, N-alkenylpropylenediamine, N-alkyldipropylenetriamine, N-alkenyldipropylenetriamine, N-alkyltripropylenetetramine, N-alkenyltripropylenetetramine, N-alkyltetrapropylenepenta Min, N-alkenyltetrapropylenepentamine, N-alkylpentapropylenehexamine, N-alkenylpentapropylene Hexamine, N-alkylbutylenediamine, N-alkenylbutylenediamine, N-alkyldibutylenetriamine, N-alkenyldibutylenetriamine, N-alkyltributylenetetramine, N-alkenyltributylenetetramine, N-alkyltetrabutylenepentamine, N-alkyl or N-alkenylalkylene polyamines such as N-alkenyltetrabutylenepentamine and the like can be mentioned. The polyamine according to the present invention includes polyamines derived from fats and oils (such as beef tallow polyamine).

  (A-3) As a carboxylic acid used for a component, a fatty acid and a succinic-acid type compound are mentioned.

  Examples of the fatty acid herein include fatty acids exemplified in the description of the above (A-2) amide compound.

  Examples of the succinic acid-based compound include succinic acid, succinic acid substituted with an alkyl group or alkenyl group having 8 to 30 carbon atoms, and the like.

［式中、Ｒ¹は炭素数８〜３０（好ましくは１２〜２４）のアルキル基又は炭素数８〜３０（好ましくは１２〜２４）のアルケニル基を示す］
で表される化合物が挙げられる。 Examples of succinic acid substituted with an alkyl group or alkenyl group having 8 to 30 carbon atoms include the following general formula (1):

[Wherein, R ¹ represents an alkyl group having 8 to 30 (preferably 12 to 24) carbon atoms or an alkenyl group having 8 to 30 (preferably 12 to 24) carbon atoms]
The compound represented by these is mentioned.

  As the component (A) according to the present invention, one of (A-1) amine compound, (A-2) amide compound, (A-3) carboxylic acid amine salt and / or sulfonic acid amine salt is used alone. Or two or more compounds having different structures may be mixed and used.

  In the present invention, since it is more excellent in rust prevention and the effect of suppressing the malfunction of control valves and the like caused by iron formate, (A) an amine compound, (A-3) a carboxylate amine as the component (A) Salts and / or sulfonic acid amine salts are preferred, and (A-1) amine compounds are more preferred.

  The content of the component (A) is required to be 0.01% by mass, more preferably 0.03% by mass or more, and 0.05% by mass from the viewpoint of rust prevention. It is even more preferable that it is above. In addition, from the viewpoint of thermal stability, antioxidant life, and wear resistance, it is necessary that it is 2% by mass or less, preferably 1.5% by mass or less, and more preferably 1% by mass or less. More preferred.

  The component (B) according to the present invention is an ashless antioxidant. Here, the ashless antioxidant means an antioxidant containing no metal element. Conventionally, metal antioxidants such as zinc dithiophosphate (ZnDTP) have been used as antioxidants for hydraulic fluids. However, when metal antioxidants are used, water and heat can be used over a long period of time. This is not preferable because sludge is likely to be generated due to deterioration or the like, and this sludge enters the sliding surface and increases sliding resistance.

(B) As the antioxidant, various known ones can be used. More specifically,
(B-1) Phenol type antioxidant (B-2) Amine type antioxidant etc. are mentioned.

  As the (B-1) phenolic antioxidant, any alkylphenolic compound used as an antioxidant for lubricating oils can be used. For example, the phenolic antioxidant is represented by the following general formula (2) or (4). One or more alkylphenol compounds selected from the compounds are preferred.

［式（２）中、Ｒ²は炭素数１〜４のアルキル基を示し、Ｒ³は水素原子又は炭素数１〜４のアルキル基を示し、Ｒ⁴は水素原子、炭素数１〜４のアルキル基、又は下記一般式（３）、（４）で表される基を示す。

[In the formula (2), R ² represents an alkyl group having 1 to 4 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ⁴ represents a hydrogen atom, and has 1 to 4 carbon atoms. An alkyl group or a group represented by the following general formulas (3) and (4) is shown.

（式（３）中、Ｒ⁵は炭素数１〜６のアルキレン基を示し、Ｒ⁶は炭素数１〜２４のアルキル基又は炭素数１〜２４のアルケニル基を示す。）

(In formula (3), R ⁵ represents an alkylene group having 1 to ⁶ carbon atoms, and R ⁶ represents an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 1 to 24 carbon atoms.)

（式（４）中、Ｒ⁷は炭素数１〜６のアルキレン基を示し、Ｒ⁸は炭素数１〜４のアルキル基を示し、Ｒ⁹は水素原子又は炭素数１〜４のアルキル基を示し、ｎは０又は１の整数を示す。）］

(In formula (4), R ⁷ represents an alkylene group having 1 to 6 carbon atoms, R ⁸ represents an alkyl group having 1 to 4 carbon atoms, R ⁹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms N represents an integer of 0 or 1.)]

［式（５）中、Ｒ¹⁰は及びＲ¹⁴は同一でも異なっていてもよく、それぞれ炭素数１〜４のアルキル基を示し、Ｒ¹¹及びＲ¹⁵は同一でも異なっていてもよく、それぞれ水素原子又は炭素数１〜４のアルキル基を示し、Ｒ¹²及びＲ¹³は同一でも異なっていてもよく、それぞれ炭素数１〜６のアルキレン基を示し、Ａは炭素数１〜１８のアルキレン基又は下記一般式（６）で表される基を示す。

[In the formula (5), R ¹⁰ and R ¹⁴ may be the same or different and each represents an alkyl group having 1 to 4 carbon atoms; R ¹¹ and R ¹⁵ may be the same or different and each represents hydrogen; Represents an atom or an alkyl group having 1 to 4 carbon atoms, R ¹² and R ¹³ may be the same or different, each represents an alkylene group having 1 to 6 carbon atoms, and A represents an alkylene group having 1 to 18 carbon atoms or The group represented by the following general formula (6) is shown.

—R ¹⁶ —S—R ¹⁷ — (6)
(In Formula (6), R ¹⁶ and R ¹⁷ may be the same or different and each represents an alkylene group having 1 to 6 carbon atoms.)]

In general formula (2), R ² represents an alkyl group having 1 to 4 carbon atoms. Specific examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. A tert-butyl group is preferable from the viewpoint of superior sludge resistance.

R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Specific examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, a hydrogen atom, a methyl group, or a tert-butyl group is preferable from the viewpoint of superior sludge resistance.

In the general formula (2), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a group represented by the above formula (3) or (4).

Specific examples of the alkyl group having 1 to 4 carbon atoms represented by R ⁴ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl. Examples thereof include a group, but a methyl group or an ethyl group is preferable from the viewpoint of superior sludge resistance.

In the case where R ⁴ in the general formula (2) is a group represented by the formula (3), the alkylene group having 1 to 6 carbon atoms represented by R ⁵ in the formula (3) may be linear or branched. Specifically, for example, methylene group, methylmethylene group, ethylene group (dimethylene group), ethylmethylene group, propylene group (methylethylene group), trimethylene group, linear or branched butylene Group, a linear or branched pentylene group, a linear or branched hexylene group, and the like. Among these, an alkylene group having 1 to 2 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), in that the compound represented by the general formula (2) can be produced with few reaction steps. And the like are more preferable.

On the other hand, the alkyl group or alkenyl group having 1 to 24 carbon atoms represented by R ⁶ in the formula (3) may be linear or branched, and specifically includes, for example, methyl group, ethyl group, propyl Group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, Alkyl groups such as icosyl group, henocosyl group, docosyl group, tricosyl group, tetracosyl group (these alkyl groups may be linear or branched); vinyl group, propenyl group, isopropenyl group, butenyl group, pentenyl group Hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, Ridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, octadecadienyl group, nonadecenyl group, icocenyl group, henicosenyl group, alkenyl group such as dococenyl group, tricocenyl group, tetracocenyl group (these alkenyl groups) May be linear or branched, and the position of the double bond is arbitrary). Among these, from the point which is excellent in the solubility with respect to base oil, a C4-C18 alkyl group, specifically, for example, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, An alkyl group such as an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, or an octadecyl group (these alkyl groups may be linear or branched) and preferably has 6 to 6 carbon atoms. 12 linear or branched alkyl groups are more preferable, and branched alkyl groups having 6 to 12 carbon atoms are particularly preferable.

Among the phenol compounds represented by the general formula (2), as a compound when R ⁴ is a group represented by the formula (3), R ⁵ in the formula (3) has 1 to 2 carbon atoms. More preferably, it is an alkylene group, and R ⁶ is a linear or branched alkyl group having 6 to 12 carbon atoms, R ⁵ in formula (3) is an alkylene group having 1 to 2 carbon atoms, It is particularly preferred that R ⁶ is a branched alkyl group having 6 to 12 carbon atoms.

In the case where R ⁴ in the general formula (2) is a group represented by the formula (4), R ⁷ in the formula (4) represents an alkylene group having 1 to 6 carbon atoms. The alkylene group may be linear or branched, and specific examples include various alkylene groups exemplified in the description of R ⁵ . Among these, since the compound represented by the general formula (2) can be produced with few reaction steps and its raw materials are easily available, an alkylene group having 1 to 3 carbon atoms, specifically, for example, methylene group, methyl A methylene group, an ethylene group (dimethylene group), an ethylmethylene group, a propylene group (methylethylene group), a trimethylene group, and the like are more preferable.

Moreover, R < ⁸ > in Formula (4) shows a C1-C4 alkyl group. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and the like. From the viewpoint of excellent sludge resistance, tert. -A butyl group is preferred. Examples of R ⁹ include a hydrogen atom or an alkyl group having 1 to 4 carbon atoms as described above, and a hydrogen atom, a methyl group, or a tert-butyl group is preferable from the viewpoint of excellent sludge resistance.

  N in Formula (4) represents an integer of 0 or 1. When n is 0, it takes a biphenyl structure in which two benzene rings are directly bonded.

In the general formula (2), as described above, R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a group represented by the above formula (3) or (4). is preferably a group represented by to 4 alkyl groups or the formula (4), a group represented by a methyl group, an ethyl group, or the formula (4), R ⁷ is 1 to carbon atoms More preferably, it is an alkylene group of 3, R ⁸ is a tert-butyl group, R ⁹ is a hydrogen atom, a methyl group or a tert-butyl group, and n is an integer of 0 or 1. .

Preferred compounds among the compounds represented by the general formula (2) are listed as 2,6-di-tert-butyl-p- as a compound when R ⁴ is an alkyl group having 1 to ⁴ carbon atoms. Cresol, 2,6-di-tert-butyl-4-ethylphenol and the like; As a compound when R ⁶ is a group represented by the general formula (i), (3-methyl-5-tert-butyl-4 -Hydroxyphenyl) acetate n-hexyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isohexyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate n-heptyl, ( 3-methyl-5-tert-butyl-4-hydroxyphenyl) isoheptyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate n-octyl, (3- Methyl-5-tert-butyl-4-hydroxyphenyl) isooctyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid 2-ethylhexyl, (3-methyl-5-tert-butyl-4- Hydroxyphenyl) acetic acid n-nonyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid isononyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetic acid n-decyl, (3 -Methyl-5-tert-butyl-4-hydroxyphenyl) isodecyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate n-undecyl, (3-methyl-5-tert-butyl-4 -Hydroxyphenyl) isoundecyl acetate, (3-methyl-5-tert-butyl-4-hydro Cyphenyl) acetic acid n-dodecyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetododecyl acetate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionic acid n-hexyl, (3 -Methyl-5-tert-butyl-4-hydroxyphenyl) isohexyl propionate, n-heptyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl) -4-hydroxyphenyl) isoheptyl propionate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate n-octyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionic acid Isooctyl, (3-methyl-5-tert-butyl-4- (Droxyphenyl) 2-ethylhexyl propionate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate n-nonyl, (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionic acid Isononyl, n-decyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl-4-hydroxyphenyl) isodecyl propionate, (3-methyl-5 -Tert-butyl-4-hydroxyphenyl) n-undecyl propionate, isoundecyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3-methyl-5-tert-butyl-4-hydroxy) N-dodecyl phenyl) propionate, (3-methyl-5- tert-butyl-4-hydroxyphenyl) isododecyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetate n-hexyl, (3,5-di-tert-butyl-4-hydroxyphenyl) Isohexyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) n-heptyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) isoheptyl acetate, (3,5-di-) tert-butyl-4-hydroxyphenyl) acetic acid n-octyl, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid isooctyl, (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid 2-ethylhexyl, (3,5-di-tert-butyl-4-hydroxyphenyl) acetate n-nonyl, ( , 5-Di-tert-butyl-4-hydroxyphenyl) isononyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) acetate n-decyl, (3,5-di-tert-butyl-4) -Hydroxyphenyl) isodecyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) n-undecyl acetate, (3,5-di-tert-butyl-4-hydroxyphenyl) isoundecyl acetate, 5-Di-tert-butyl-4-hydroxyphenyl) acetate n-dodecyl, (3,5-di-tert-butyl-4-hydroxyphenyl) acetate isododecyl, (3,5-di-tert-butyl-4- Hydroxyphenyl) n-hexyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) propionate Hexyl, n-heptyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, isoheptyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-diphenyl) -Tert-butyl-4-hydroxyphenyl) n-octylpropionate, (3,5-di-tert-butyl-4-hydroxyphenyl) isooctylpropionate, (3,5-di-tert-butyl-4-hydroxy) 2-ethylhexyl (phenyl) propionate, n-nonyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, isononyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N-decyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, Isodecyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, n-undecyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-tert -Butyl-4-hydroxyphenyl) isoundecyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) n-dodecyl propionate, (3,5-di-tert-butyl-4-hydroxyphenyl) Isododecyl propionate and the like; as a compound when R ⁶ is a group represented by the formula (ii), bis (3,5-di-tert-butyl-4-hydroxyphenyl), bis (3,5-di- tert-butyl-4-hydroxyphenyl) methane, 1,1-bis (3,5-di-tert-butyl-4-hydroxyphenyl) 1,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) ethane, 1,1-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 1, 2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 1,3-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis ( 3,5-di-tert-butyl-4-hydroxyphenyl) propane and the like; and mixtures thereof.

On the other hand, in said general formula (5), R < ¹⁰ > and R <^14> may be same or different, and respectively show a C1-C4 alkyl group. Specific examples of R ¹⁰ and R ¹⁴ are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Both are preferably tert-butyl groups from the viewpoint of superior sludge properties.

R ¹¹ and R ¹⁵ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of such an alkyl group include the groups described above. Among these, a hydrogen atom, a methyl group, or a tert-butyl group is preferable because they are more excellent in sludge resistance.

R ¹² and R ¹³ may be the same or different and each represents an alkylene group having 1 to 6 carbon atoms. Such alkylene groups may be linear or branched. Specific examples of R ¹² and R ¹³ include various alkylene groups exemplified in the description of R ⁵ . Among these, an alkylene group having 1 to 2 carbon atoms, specifically methylene, for example, can be produced in a reaction process with few compounds represented by the general formula (5) and the raw material is easily available. Group, methylmethylene group, ethylene group (dimethylene group) and the like are more preferable.

  Moreover, in General formula (5), A shows a C1-C18 alkylene group or group represented by the said Formula (7).

  Specific examples of the alkylene group having 1 to 18 carbon atoms represented by A include, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), an ethylmethylene group, a propylene group (methylethylene group), a trimethylene group, Butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group, etc. (these alkylene groups) May be linear or branched). Among these, because of the availability of raw materials, etc., an alkylene group having 1 to 6 carbon atoms, specifically, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group), an ethylmethylene group, a propylene group (methylethylene) Group), trimethylene group, butylene group, pentylene group, hexylene group and the like (these alkylene groups may be linear or branched), ethylene group (dimethylene group), trimethylene group, linear butylene group ( A linear alkylene group having 2 to 6 carbon atoms such as a tetramethylene group), a linear pentylene group (pentamethylene group), and a linear hexylene group (hexamethylene group) is particularly preferable.

  Among the alkylphenols represented by the general formula (5), a compound represented by the following formula (7) is particularly preferable as a compound when A is an alkylene group having 1 to 18 carbon atoms.

In the case where A in the general formula (5) is a group represented by the formula (6), R ¹⁶ and R ¹⁷ in the formula (6) may be the same or different and each have 1 to 6 represents an alkylene group. Such alkylene groups may be linear or branched. Specific examples of R ¹⁶ and R ¹⁷ include various alkylene groups exemplified in the description of R ⁵ . As R ¹⁶ and R ¹⁷ , since the raw materials for producing the compound represented by the general formula (5) are easy to obtain, each independently an alkylene group having 1 to 3 carbon atoms, specifically, for example, More preferred are a methylene group, a methylmethylene group, an ethylene group (dimethylene group), an ethylmethylene group, a propylene group (methylethylene group), a trimethylene group, and the like.

  Of the alkylphenols represented by the general formula (5), a compound represented by the following formula (8) is particularly preferred as a compound when A is a group represented by the formula (6).

上述した通り、一般式（５）において、Ａは炭素数１〜１８のアルキレン基又は一般式（６）で表される基を示すが、耐スラッジ性により優れることから、Ａは一般式（６）で表される基であることが好ましい。

As described above, in the general formula (5), A represents an alkylene group having 1 to 18 carbon atoms or a group represented by the general formula (6). It is preferable that it is group represented by.

  On the other hand, as the (B-2) amine-based antioxidant, any aromatic amine-based compound used as an antioxidant for lubricating oils can be used, and is not particularly limited. Preferred are one or more aromatic amines selected from phenyl-α-naphthylamines represented by the formula (9) or p, p′-dialkyldiphenylamines represented by the following general formula (10): As mentioned.

［式（９）中、Ｒ¹⁸は水素原子又は炭素数１〜１６のアルキル基を示す。］

[In the formula (9), R ¹⁸ represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms. ]

［式（１０）中、Ｒ¹⁹及びＲ²⁰は同一でも異なっていてもよく、それぞれ炭素数１〜１６のアルキル基を示す。］

[In Formula (10), R ¹⁹ and R ²⁰ may be the same or different and each represents an alkyl group having 1 to 16 carbon atoms. ]

In the above formula (9), R ¹⁸ represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms. When R ¹⁸ is an alkyl group, when the number of carbon atoms in R ¹⁸ exceeds 16, the ratio of functional groups in the molecule is reduced, and sludge resistance may be reduced. The alkyl group may be linear or branched.

Specific examples of the alkyl group represented by R ¹⁸ include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl. Group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group and the like (these alkyl groups may be linear or branched).

Among the phenyl-α-naphthylamines represented by the general formula (9), when R ¹⁸ is an alkyl group, it has 8 to 16 carbon atoms because it has excellent solubility of its own oxidation product in the base oil. And a branched alkyl group having 8 to 16 carbon atoms derived from an oligomer of an olefin having 3 or 4 carbon atoms is more preferable. Specific examples of the olefin having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene and isobutylene, but from the viewpoint of excellent solubility of its own oxidation product in the base oil, Propylene or isobutylene is preferred. Further, when R ¹⁸ is an alkyl group, it is derived from a branched octyl group derived from a dimer of isobutylene or a trimer of propylene because it is more excellent in solubility of its own oxidation product in a base oil. A branched dodecyl group derived from a trimer of isobutylene, a branched dodecyl group derived from a tetramer of propylene, a branched dodecyl group derived from a tetramer of propylene, or a branched pentadecyl group derived from a pentamer of propylene More preferably, a branched octyl group derived from a dimer of isobutylene, a branched dodecyl group derived from a trimer of isobutylene, or a branched dodecyl group derived from a tetramer of propylene is most preferable.

As described above, R ¹⁸ may be either a hydrogen atom or an alkyl group, but is preferably a hydrogen atom from the viewpoint of antioxidant properties. Moreover, it is preferable that it is an alkyl group from the soluble point of the oxidation product by oxidation of the compound itself represented by Formula (9).

Of the phenyl-α-naphthylamines represented by the formula (9), a commercially available compound may be used as the compound in which R ¹⁸ is an alkyl group. In addition, phenyl-α-naphthylamine and a halogenated alkyl compound having 1 to 16 carbon atoms, an olefin having 2 to 16 carbon atoms, or an olefin oligomer having 2 to 16 carbon atoms and phenyl-α-naphthylamine using a Friedel-Crafts catalyst. It can be easily synthesized by reacting. Specific examples of Friedel-Crafts catalysts in this case include metal halides such as aluminum chloride, zinc chloride, and iron chloride; sulfuric acid, phosphoric acid, phosphorus pentoxide, boron fluoride, acidic clay, activated clay, etc. An acidic catalyst or the like can be used.

On the other hand, in the p, p′-dialkyldiphenylamine represented by the formula (10), R ¹⁹ and R ²⁰ may be the same or different and each represents an alkyl group having 1 to 16 carbon atoms. In addition, when one or both of R ¹⁹ and R ²⁰ are hydrogen atoms, sludge may be generated due to oxidation of the compound represented by the formula (10) and may be settled. Also, if the carbon number of the alkyl group represented by R ¹⁹ and R ²⁰ exceeds 16, the proportion of the functional group occupying in the molecule is reduced, resistance to sludge formation may be reduced.

Specific examples of R ¹⁹ and R ²⁰ include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl Group, tetradecyl group, pentadecyl group, hexadecyl group and the like (these alkyl groups may be linear or branched). Among these, as R ¹⁹ and R ²⁰ , a branched alkyl group having 3 to 16 carbon atoms is preferable from the viewpoint of excellent solubility of the oxidation product itself in the base oil, and further an olefin having 3 or 4 carbon atoms, Alternatively, a branched alkyl group having 3 to 16 carbon atoms derived from the oligomer thereof is more preferable.

  Specific examples of the olefin having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene, and isobutylene, but the solubility of its own oxidation product in a lubricating base oil is excellent. From the viewpoint, propylene or isobutylene is preferable.

Further, R ¹⁹ and R ²⁰ are derived from an isopropyl group derived from propylene or isobutylene from the viewpoint that the solubility of the oxidation product of the compound represented by the formula (10) by oxidation of the compound itself in the lubricating base oil is excellent. Tert-butyl group, branched hexyl group derived from propylene dimer, branched octyl group derived from isobutylene dimer, branched nonyl group derived from propylene trimer, isobutylene Even more preferred is a branched dodecyl group derived from a trimer of the above, a branched dodecyl group derived from a tetramer of propylene or a branched pentadecyl group derived from a pentamer of propylene, and is derived from isobutylene. tert-butyl group, branched hexyl group derived from propylene dimer, branched octyl derived from isobutylene dimer Group, a branched nonyl group derived from propylene trimer, is a branched dodecyl group derived from a tetramer of branched dodecyl or propylene derived from a trimer of isobutylene most preferred.

  A commercially available product may be used as p, p'-dialkyldiphenylamine represented by the formula (10). Further, similarly to the phenyl-α-naphthylamine represented by the formula (9), diphenylamine and a halogenated alkyl compound having 1 to 16 carbon atoms, an olefin having 2 to 16 carbon atoms, an olefin having 2 to 16 carbon atoms, or these These oligomers and diphenylamine can be easily synthesized using a Friedel-Crafts catalyst. As the Friedel-Crafts catalyst at this time, specifically, for example, metal halides and acidic catalysts listed in the synthesis of phenyl-α-naphthylamine are used.

  As a matter of course, as the component (B) of the present invention, one compound selected from a phenolic antioxidant and an amine antioxidant may be used alone, or two or more kinds may be used. However, it is preferable to use an amine-based antioxidant and a phenol-based antioxidant in combination because of better oxidation stability.

  In consideration of workability in producing the hydraulic fluid composition of the present invention, it is preferable to use a liquid at room temperature (20 ° C.) among the components (B).

  The upper limit of the content of the component (B) in the hydraulic fluid composition of the present invention is 2% by mass, more preferably 1% by mass, based on the total amount of the composition. When the content exceeds 2% by mass, it is not preferable because it causes sludge and the like.

  On the other hand, the lower limit of the content of the component (B) is 0.01% by mass, preferably 0.05% by mass, and more preferably 0.1% by mass based on the total amount of the composition. When the content of the component (B) is less than 0.01% by mass, the antioxidant performance is insufficient, which is not preferable.

  The component (C) of the present invention is an ashless antiwear agent.

  In the present invention, the ashless antiwear agent means an antiwear agent containing no metal element.

  Examples of such an antiwear agent include the following compounds (C-1) to (C-9).

(C-1) Dihydrocarbyl polysulfide (C-2) Sulfurized ester (C-3) Sulfurized mineral oil (C-4) Phosphate ester (C-5) Acidic phosphate ester (C-6) Acidic phosphate ester (C-7) Chlorinated phosphate ester (C-8) Phosphite ester (C-9) Thiophosphate ester (C-10) Substituted phosphate ester

  Hereinafter, (C-1) to (C-9) will be described in order.

  (C-1) Dihydrocarbyl polysulfide is a sulfur compound generally called polysulfide or sulfurized olefin, and is specifically represented by the following general formula (11).

_{^{R 21 -S x -R 22 (11}} )
[In the formula (11), R ²¹ and R ²² may be the same or different and each has a linear or branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a carbon number. An alkylaryl group having 6 to 20 carbon atoms or an arylalkyl group having 6 to 20 carbon atoms is represented, and x represents an integer of 2 to 6 (preferably 2 to 5). ]
Specific examples of the alkyl group represented by R ²¹ and R ²² in the formula (11) include an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. , Linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, straight Chain or branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or A branched heptadecyl group, a linear or branched octadecyl group, a linear or branched nonadecyl group, a linear or branched icosyl group can be mentioned.

Specific examples of the aryl group represented by R ²¹ and R ²² include a phenyl group and a naphthyl group.

Specific examples of the alkylaryl group represented by R ²¹ and R ²² include a tolyl group (including all structural isomers), an ethylphenyl group (including all structural isomers), straight-chain or branched Propylphenyl group (including all structural isomers), straight chain or branched butylphenyl group (including all structural isomers), straight chain or branched pentylphenyl group (including all structural isomers), straight Chain or branched hexylphenyl group (including all structural isomers), linear or branched heptylphenyl group (including all structural isomers), linear or branched octylphenyl group (including all structural isomers) Straight chain or branched nonylphenyl group (including all structural isomers), straight chain or branched decylphenyl group (including all structural isomers), straight chain or branched undecylphenyl group (all Including structural isomers of Branched dodecylphenyl group (including all structural isomers), xylyl group (including all structural isomers), ethylmethylphenyl group (including all structural isomers), diethylphenyl group (all structural isomers) ), Di (linear or branched) propylphenyl group (including all structural isomers), di (straight or branched) butylphenyl group (including all structural isomers), methylnaphthyl group (including Including all structural isomers), ethyl naphthyl group (including all structural isomers), linear or branched propyl naphthyl group (including all structural isomers), linear or branched butyl naphthyl group (all ), Dimethylnaphthyl group (including all structural isomers), ethylmethylnaphthyl group (including all structural isomers), diethylnaphthyl group (including all structural isomers), di ( Linear or Branched) containing propyl naphthyl group (all structural isomers), a di (straight or branched) butylnaphthyl groups (all structural isomers) and the like.

Specific examples of the arylalkyl group represented by R ²¹ and R ²² include a benzyl group, a phenylethyl group (including all isomers), a phenylpropyl group (including all isomers), and the like. Can do.

R ²¹ and R ²² are each an alkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 8 carbon atoms, an alkylaryl group having 7 to 8 carbon atoms, or carbon derived from propylene, 1-butene or isobutylene. It is preferably an arylalkyl group of several 7 to 8.

  Specifically, examples of the alkyl group include an isopropyl group, a branched hexyl group derived from a propylene dimer (including all branched isomers), and a moiety derived from a propylene trimer. Branched nonyl group (including all branched isomers), branched dodecyl group derived from propylene tetramer (including all branched isomers), branch derived from propylene pentamer Branched pentadecyl group (including all branched isomers), branched octadecyl group (including all branched isomers) derived from propylene hexamer, sec-butyl group, tert-butyl group Branched octyl groups derived from 1-butene dimer (including all branched isomers), branched octyl groups derived from isobutylene dimer (all branched isomers Derived from 1-butene trimer) Branched dodecyl group (including all branched isomers), branched dodecyl group derived from isobutylene trimer (including all branched isomers), derived from 1-butene tetramer Branched hexadecyl groups (including all branched isomers), branched hexadecyl groups (including all branched isomers) derived from isobutylene tetramer, and the like. Examples of the aryl group include a phenyl group. Examples of the alkylaryl group include a tolyl group (including all structural isomers), an ethylphenyl group (including all structural isomers), a xylyl group (including all structural isomers), and the like. . Examples of the arylalkyl group include a benzyl group and a phenethyl group (including all isomers).

Furthermore, R ²¹ and R ²² are more preferably each independently a branched alkyl group having 3 to 18 carbon atoms derived from propylene, from the viewpoint of its lubricating performance, and the number of carbon atoms derived from propylene. Particularly preferred is a 6-15 branched alkyl group.

  (C-1) The sulfur content of dihydrocarbyl polysulfide is not particularly limited, but is preferably 10 to 55 mass%, more preferably 20 to 50 mass%, from the viewpoint of excellent extreme pressure performance.

  (C-2) Specific examples of the sulfurized ester include animal and vegetable fats and oils such as beef tallow, pork tallow, fish tallow, rapeseed oil and soybean oil; unsaturated fatty acids (oleic acid, linoleic acid and the above-mentioned animal and plant fats and oils) And unsaturated fatty acid esters obtained by reacting various alcohols; and mixtures thereof and the like obtained by sulfiding by any method.

  (C-2) The sulfur content of the sulfurized ester is not particularly limited, but is preferably 2 to 40% by mass, more preferably 5 to 35% by mass from the viewpoint of excellent extreme pressure performance.

  (C-3) Sulfurized mineral oil refers to one obtained by dissolving elemental sulfur in mineral oil. Although it does not restrict | limit especially as this mineral oil, Specifically, the mineral oil type | system | group lubricating base oil etc. which were illustrated in description of a base oil are mentioned. In addition, as the elemental sulfur, any form such as a lump, powder, or molten liquid may be used, but a powder or molten liquid can be efficiently dissolved in the base oil. Therefore, it is preferable. When using molten liquid elemental sulfur, the liquids are mixed together, so there is an advantage that the melting operation can be performed in a very short time, but it is handled above the melting point of elemental sulfur. In addition, special equipment such as heating equipment is required, and handling in a high-temperature atmosphere is dangerous, and handling is not always easy. On the other hand, powdery simple sulfur is particularly preferable because it is inexpensive and easy to handle and has a sufficiently short dissolution time. The sulfur content in the sulfide mineral oil is not particularly limited, but is preferably 0.05 to 1.0 mass%, more preferably 0.1 to 0.5 mass%, based on the total amount of sulfide mineral oil.

  Specific examples of the (C-4) phosphate ester include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, triundecyl phosphate. Dodecyl phosphate, tritridecyl phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, Examples include dildiphenyl phosphate and xylenyl diphenyl phosphate.

  Specific examples of the (C-5) acidic phosphate ester include monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, Monoundecyl acid phosphate, monododecyl acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate , Dibutyl acid phosphate, dipentyl acid phosphate , Dihexyl acid phosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate phosphate, ditetradecyl acid phosphate decide phosphate phosphate , Dihexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, and dioleyl acid phosphate.

  (C-6) As the amine salt of the acidic phosphate ester, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropyl of the above acidic phosphate ester With amines such as amine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, and trioctylamine Salt.

  Examples of the (C-7) chlorinated phosphate ester include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, tris-chlorophenyl phosphate, and polyoxyalkylene bis [di (chloroalkyl)] phosphate.

  (C-8) As phosphites, dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite Phosphite, dioleyl phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite , Triundecyl phosphite, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite, and tricresyl phosphite.

  Examples of (C-9) thiophosphate esters include tributyl phosphorothioate, tripentyl phosphorothioate, trihexyl phosphorothionate, triheptyl phosphorothionate, trioctyl phosphorothionate, trinonyl phosphorothioate. , Tridecyl phosphorothioate, triundecyl phosphorothioate, tridodecyl phosphorothioate, tritridecyl phosphorothionate, tritetradecyl phosphorothionate, tripentadecyl phosphorothionate, trihexadecyl Phosphorothioate, triheptadecyl phosphorothionate, trioctadecyl phosphorothioate, trioleyl phosphorothioate, triphenyl phosphorothioate Tricresyl phosphorothioate, trixylenyl phosphorothioate, cresyl diphenyl phosphorothioate, xylenyl diphenyl phosphorothionate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) Phosphorothioate, tris (n-butylphenyl) phosphothionate, tris (isobutylphenyl) phosphothionate, tris (s-butylphenyl) phosphothionate, tris (t-butylphenyl) phosphothionate Etc.

  (C-10) A substituted phosphate ester is a compound represented by the following general formula (12).

［式（１２）中、Ｒ²³、Ｒ²⁴及びＲ²⁵は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜２０の炭化水素基又は下記一般式（１３）：
−Ｒ²⁶−ＣＯＯ−Ｒ²⁷ （１３）
（式（１３）中、Ｒ²⁶は炭素数１〜６のアルキレン基を示し、Ｒ²⁷は水素原子又は炭素数１〜２０の炭化水素基を示す）
で表される基を示し、Ｒ²³、Ｒ²⁴及びＲ²⁵のうちの少なくとも１つは一般式（１３）で表される基であり、Ｘ¹、Ｘ²、Ｘ³及びＸ⁴は同一でも異なっていてもよく、それぞれ酸素原子又は硫黄原子を示す。］

[In the formula (12), R ²³ , R ²⁴ and R ²⁵ may be the same or different and are each a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or the following general formula (13):
—R ²⁶ —COO—R ²⁷ (13)
(In formula (13), R ²⁶ represents an alkylene group having 1 to 6 carbon atoms, and R ²⁷ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms)
Wherein at least one of R ²³ , R ²⁴ and R ²⁵ is a group represented by the general formula (13), and X ¹ , X ² , X ³ and X ⁴ may be the same They may be different and each represents an oxygen atom or a sulfur atom. ]

Specific examples of the hydrocarbon group represented by R ²³ , R ²⁴ and R ²⁵ include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, Alkyl groups such as decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group (these alkyl groups may be linear or branched); butenyl group, Alkenyl groups such as pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl Can be linear or branched); cyclopentyl A cycloalkyl group having 5 to 7 carbon atoms such as a group, a cyclohexyl group, a cycloheptyl group; a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, C6-C11 alkylcycloalkyl groups such as diethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, methylethylcycloheptyl group, diethylcycloheptyl group (the substitution position of the alkyl group in the cycloalkyl group is arbitrary) ); Aryl groups such as phenyl and naphthyl groups; tolyl, xylyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylpheny Group, octylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, etc., an alkylaryl group having 7 to 18 carbon atoms (the alkyl group may be linear or branched, The substitution position of the alkyl group is also arbitrary); arylalkyl groups having 7 to 12 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, phenylhexyl group (the alkyl group is a straight chain) Or may be branched). Among these, a C1-C12 alkyl group is preferable and a C1-C8 alkyl group is more preferable.

The alkylene group having 1 to 6 carbon atoms represented by R ²⁶ in the formula (13) may be linear or branched, and specifically includes, for example, a methylene group, a methylmethylene group, an ethylene group (dimethylene group). ), Ethylmethylene group, propylene group (methylethylene group), trimethylene group, linear or branched butylene group, linear or branched pentylene group, linear or branched hexylene group, and the like. Among these, an alkylene group having 1 to 4 carbon atoms is preferable, an alkylene group having 1 to 3 carbon atoms is more preferable, an alkylene group having 1 or 2 carbon atoms is more preferable, and a methylene group or an ethylene group is particularly preferable.

Further, R ²⁷ in the formula (13) represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Specific examples of the hydrocarbon group represented by R ²⁷ include hydrocarbon groups having 1 to 20 carbon atoms exemplified in the description of R ²³ , R ²⁴ and R ²⁵ . Among these, a hydrogen atom and an alkyl group having 1 to 12 carbon atoms are preferable, a hydrogen atom and an alkyl group having 1 to 8 carbon atoms are more preferable, a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are more preferable, and a hydrogen atom Is particularly preferred.

R ²³ , R ²⁴ and R ²⁵ in the formula (12) may be the same or different, but at least one of these needs to be a group represented by the formula (13).

Moreover, it is preferable that one or two of R ²³ , R ²⁴ and R ²⁵ is a hydrocarbon group having 1 to 20 carbon atoms, and the remaining two or one is a group represented by the formula (13). , R ²³ , R ²⁴ and R ²⁵ are more preferably a hydrocarbon group having 1 to 20 carbon atoms, and the remaining one is a group represented by the formula (13).

X ¹ , X ² , X ³ and X ⁴ in formula (12) may be the same or different and each represents an oxygen atom or a sulfur atom. X ^1, is 1-3 oxygen atoms of X ^2, X ³ and X ^4, it is preferable that the remaining 3 to one is a sulfur atom, of X ^1, X ^2, X ³ and X ⁴ More preferably, two of them are oxygen atoms and the remaining two are sulfur atoms.

  As (C) component used by this invention, since there is little generation | occurrence | production of sludge, (C-4) phosphate ester, (C-5) acidic phosphate ester, (C-6) acidic phosphate ester Amine salts, (C-7) chlorinated phosphates, (C-8) phosphites, (C-9) thiophosphates, (C-10) substituted phosphates are preferred, (C-4) Phosphate esters are more preferred.

The upper limit of the content of the component (C) in the hydraulic fluid composition of the present invention is 5% by mass, preferably 2% by mass, more preferably 1.5% by mass based on the total amount of the composition. When the content exceeds 5% by mass, the thermal stability is inferior and sludge is generated, which is not preferable.
On the other hand, the lower limit of the content of component (C) is 0.005% by mass, preferably 0.01% by mass, more preferably 0.05% by mass, based on the total amount of the composition. When the content of the component (C) is less than 0.005% by mass, the wear resistance is insufficient, which is not preferable.

  In the present invention, for the purpose of further improving the performance, if necessary, a rust inhibitor other than the component (A), a metal deactivator, a viscosity index improver, a pour point depressant, an antifoaming agent, You may contain various additives represented by a demulsifier, a stick slip inhibitor, an oily agent, etc. individually or in combination of several types.

  Examples of the rust inhibitor other than the component (A) include a polyhydric alcohol partial ester compound and a succinic acid partial ester compound.

  Any polyhydric alcohol can be used as the polyhydric alcohol partial ester compound, but glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitan are preferable.

  Further, the carboxylic acid constituting the partial ester may be a saturated fatty acid or an unsaturated fatty acid, and may be a linear fatty acid or a branched fatty acid. Moreover, although there is no restriction | limiting in particular about carbon number, A C12-C20 thing is preferable.

  The partial ester here means an ester remaining in the form of a hydroxyl group in which at least one of the hydroxyl groups in the polyhydric alcohol is not esterified. Among these, a monoester in which only one of a plurality of hydroxyl groups is esterified is preferable because the detergency can be further improved.

Specific examples of the polyhydric alcohol partial ester include glycerin monododecanoate (glycerin monolaurate), glycerin monoisolaurate, glycerin monotetradecanoate (glycerin monomyristate), glycerin monoisomyristate, Glycerol monohexadecanoate (glycerin monopalmitate), glycerin monoisopalmitate, glycerin monooctadecanoate (glycerin monostearate), glycerin monoisostearate, glycerin monooctadecenoate (glycerin monooleate) Glycerol monoesters such as glycerol monoisooleate;
Trimethylolpropane monododecanoate (trimethylolpropane monolaurate), trimethylolpropane monoisolaurate, trimethylolpropane monotetradecanoate (trimethylolpropane monomyristate), trimethylolpropane monoisomyristate, trimethylolpropane Methylolpropane monohexadecanoate (trimethylolpropane monopalmitate), trimethylolpropane monoisopalmitate, trimethylolpropane monooctadecanoate (trimethylolpropane monostearate), trimethylolpropane monoisostearate, trimethylolpropane monoisostearate Trimethylol group such as methylolpropane monooctadecenoate (trimethylolpropane monooleate), trimethylolpropane monoisooleate Pan mono ester;
Pentaerythritol monododecanoate (pentaerythritol monolaurate), pentaerythritol monoisolaurate, pentaerythritol monotetradecanoate (pentaerythritol monomyristate), pentaerythritol monoisomyristate, pentaerythritol monohexadecanoate (Pentaerythritol monopalmitate), pentaerythritol monoisopalmitate, pentaerythritol monooctadecanoate (pentaerythritol monostearate), pentaerythritol monoisostearate, pentaerythritol monooctadenoate (pentaerythritol monooleate) ), Pentaerythritol monoesters such as pentaerythritol monoisooleate;
Sorbitan monododecanoate (sorbitan monolaurate), sorbitan monoisolaurate, sorbitan monotetradecanoate (sorbitan monomyristate), sorbitan monoisomyristate, sorbitan monohexadecanoate (sorbitan monopalmitate), Sorbitan monoesters such as sorbitan monoisopalmitate, sorbitan monooctadecanoate (sorbitan monostearate), sorbitan monoisostearate, sorbitan monooctadecenoate (sorbitan monooleate), sorbitan monoisooleate; and A mixture of these is preferably used.

  Examples of the succinic acid partial ester compound include partial esters of alkyl succinic acid or alkenyl succinic acid and alcohol. Among these, partial esters (monoesters) of alkenyl succinic acid and alcohol are preferably used. Here, the carbon number of the alkenyl group is arbitrary, but those having 8 to 18 carbon atoms are usually used.

  The alcohol constituting the partial ester may be either a monohydric alcohol or a dihydric or higher polyhydric alcohol, but monohydric alcohols and dihydric alcohols are preferred.

  As the monohydric alcohol, usually an aliphatic alcohol having 8 to 18 carbon atoms is preferably used. These may be linear or branched, and may be saturated or unsaturated.

  As the dihydric alcohol, alkylene glycol and polyoxyalkylene glycol are preferably used. Specific examples of the alkylene glycol include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, octylene glycol, nonylene glycol, and decylene glycol. Moreover, as polyoxyalkylene glycol, what homopolymerized or copolymerized alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide, is used. In addition, in the polyoxyalkylene glycol, when alkylene oxides having different structures are copolymerized, there is no particular limitation on the polymerization form of the oxyalkylene group, which may be random copolymerization or block copolymerization. . Although there is no restriction | limiting in particular about a polymerization degree, The thing of 2-10 is preferable, The thing of 2-8 is more preferable, The thing of 2-6 is used still more preferably.

  The content when blending the polyhydric alcohol partial ester compound and the succinic acid partial ester compound is arbitrary, but is preferably 0.01 to 1% by mass based on the total amount of the hydraulic fluid composition.

  Furthermore, as rust preventives other than the component (A), metal soaps such as fatty acid metal salts, lanolin fatty acid metal salts, and oxidized wax metal salts; sulfonates such as calcium sulfonate and barium sulfonate; oxidized wax; amine And the like. In the present invention, one or two or more compounds arbitrarily selected from these rust inhibitors can be contained in any amount, but usually the content of these rust inhibitors is The total amount of the hydraulic fluid composition is preferably 0.01 to 1% by mass.

  Specific examples of the metal deactivator include benzotriazole, thiadiazole, and imidazole compounds. In the present invention, one or two or more compounds arbitrarily selected from these metal deactivators can be contained in any amount, but the content is usually determined by hydraulic operation. It is desirable that it is 0.001-1 mass% on the basis of the total amount of the oil composition.

  Specific examples of the viscosity index improver include a copolymer of one or more monomers selected from various methacrylates or a hydrogenated product thereof, an ethylene-α-olefin copolymer (as α-olefin). Can be exemplified by propylene, 1-butene, 1-pentene, etc.) or a hydride thereof, polyisobutylene or a hydrogenated product thereof, a hydride of a styrene-diene copolymer, and a so-called non-dispersed viscosity. An index improver etc. can be illustrated. In the present invention, one or two or more compounds arbitrarily selected from these viscosity index improvers can be contained in any amount, but the content is usually determined by hydraulic fluid. The content is desirably 0.01 to 10% by mass based on the total amount of the composition.

  Specific examples of the pour point depressant include copolymers of one or more monomers selected from various acrylic esters and methacrylic esters or hydrogenated products thereof. In the present invention, one or two or more compounds arbitrarily selected from these pour point depressants can be contained in any amount, but the content thereof is usually hydraulic oil. It is desirable that it is 0.01-5 mass% on the basis of the total amount of the composition.

  Specific examples of the antifoaming agent include silicones such as dimethyl silicone and fluorosilicone. In the present invention, one or two or more compounds arbitrarily selected from these antifoaming agents can be contained in any amount, but the content is usually determined by the hydraulic fluid composition. It is desirable that it is 0.001-0.05 mass% on the basis of the total amount of things.

  Specific examples of the stick-slip preventing agent include polyhydric alcohol esters (complete esters and partial esters).

  Specific examples of the oily agent include fatty acids, esters, alcohols and the like. Usually, the content is desirably 0.01 to 0.5% by mass based on the total amount of the hydraulic fluid composition.

  The hydraulic fluid composition of the present invention contains the components (A) to (C) described above and other additives as necessary in the base oil, but substantially contains zinc dithiophosphate (ZnDTP). It is necessary not to contain. When a hydraulic fluid composition containing ZnDTP is used under high shear conditions, not only the sludge resistance is lowered, but also the effect of improving the friction characteristics becomes insufficient.

  The hydraulic fluid composition of the present invention having the above structure is excellent in all of thermal / oxidation stability, rust prevention, sludge generation prevention and wear resistance, and rust and the like due to the generation of organic acids such as formic acid. Generation of sludge and deterioration of hydraulic fluid can be prevented. In particular, in a closed hydraulic operation system, when organic acid such as formic acid is generated inside the system, diffusion due to volatilization of the organic acid cannot be expected. However, the hydraulic fluid composition of the present invention is used for such a hydraulic operation system. Even if it is a case, the outstanding effect is exhibited. In addition, since the hydraulic fluid composition of the present invention has excellent rust prevention properties, it has a sufficient rust prevention effect even when operating a hydraulic operation system in which the oil film is hard to be held in the piping because of its short usage time. Can be obtained.

  Next, an operation method of the hydraulic operation system of the present invention will be described.

The operating method of the hydraulic operating system of the present invention is such that when the hydraulic operating system having a portion where the shear stress applied to the hydraulic operating oil is 10 ³ S ⁻¹ or more is operated, the hydraulic operating oil composition of the present invention is used as the hydraulic operating oil. It is characterized by using a thing.

The hydraulic operation system according to the present invention is not particularly limited as long as it has a portion where the shear stress applied to the hydraulic fluid is 10 ³ S ⁻¹ or more. Examples include actuators that have been improved in performance through higher precision. Such a hydraulic operation system drives heavy objects such as machine tools such as high-speed punching presses, high-speed rolling mills, high-speed pile driving machines, vibration generators (high-speed vibration testing machines), flight simulators for pilot training, and stage equipment. When it is used for facilities and the like, especially when used for a vibrator (high-speed vibration tester), its superior performance is more exhibited.

  Hereinafter, an operation method of a hydraulic operation system including a servo valve will be described in detail as an example.

  FIG. 1 is a schematic cross-sectional view showing an example of a hydraulic operation system including a servo valve. In FIG. 1, a hydraulic pump 2 and a cylinder 3 are accommodated in a housing 1, and these are respectively connected to a servo valve 4 via piping. The space in the housing 1 is filled with the hydraulic fluid composition 100 of the present invention.

  The hydraulic pump 2 includes an electric motor 5 as a drive source. A suction filter 6 is connected to the front stage (upstream side) of the hydraulic pump, and a filter 8 including a pressure gauge 7 is connected between the hydraulic pump 2 and the servo valve 4. By driving the hydraulic pump 2, the hydraulic fluid composition 100 sucked from the suction filter 6 is sent to the servo valve 4 through the filter 8. An engine may be used instead of the electric motor 5 as a drive source of the hydraulic pump 2.

  The servo valve 4 switches the flow path and controls the flow rate of the hydraulic fluid composition 100 when supplying the hydraulic fluid composition 100 from the hydraulic pump 2 to the cylinder 3. The operation in the servo valve 4 will be described later.

  A piston composed of a piston head 9 and a rod 10 is accommodated in the cylinder 3, and this piston can move along the longitudinal direction of the cylinder 3. The interior of the cylinder 3 is partitioned into a cylinder port 11a and a cylinder port 11b by a piston head 9, and the hydraulic fluid composition 100 from the servo valve 4 is supplied to each cylinder port 11a and 11b. Piping to connect is connected. Although the configuration on the other end side of the rod 10 is not shown in FIG. 1, the configuration on the other end side differs depending on the type of hydraulic machine. For example, the other end of the rod 10 can be connected to a crank drive unit to convert the reciprocating motion of the rod 10 into rotational motion. In addition, the object can be reciprocated using the reciprocating motion of the rod 10 as it is like a vibrator.

  Here, the operation of each member in the servo valve 4 and the flow of the hydraulic fluid composition 100 will be described with reference to FIG. 2 which is a schematic sectional view of the servo valve 4. In FIG. 2, the solid line arrows represent the movement direction of the members, and the broken line arrows represent the flow of the hydraulic fluid composition 100.

  The servo valve 4 shown in FIG. 2 is an electro-hydraulic type using a nozzle flapper 20 and a spool valve 24. In FIG. 2, a flapper 22 connected to the torque motor 21 is disposed inside the nozzle flapper main body 20, and a pair of opposed nozzles 23 a and 23 b are provided with the flapper 22 interposed therebetween. Between the nozzles 23 a and 23 b, the flapper 22 can move with a predetermined moving distance by the operation of the torque motor 21. Each of the nozzles 23a and 23b is connected to a flow path provided with an introduction port 28a for introducing the hydraulic fluid composition 100 from the hydraulic pump 2 into the servo valve 4. The nozzle flapper body 20 is connected to the nozzles 23a and 23b. The hydraulic fluid composition 100 is supplied to both spaces partitioned by the internal flapper 22. The hydraulic fluid composition 100 supplied to the space is discharged into the housing 1 from a discharge port 29 provided at a predetermined position of the nozzle flapper body 20, and is sucked from the suction filter 6 and repeatedly used.

  In FIG. 2, a spool 25 is accommodated in a cylindrical hollow spool valve body 24. The spool 25 includes three partition members 25a, 25b, and 25c arranged in the longitudinal direction of the spool valve body 24, and two rods 26a and 26b that connect two of these partition members and hold them at a predetermined interval. It is configured. A space formed by the inner wall surface of the spool valve main body 24 and the partition member 25b or 25c at the end of the spool 25 communicates with the nozzles 23a and 23b through flow paths, respectively. On the other hand, the wall surface of the spool valve body 24 is provided with openings 27a, 28b, and 27b along the longitudinal direction thereof. The openings 27a and 27b are supply ports for supplying the hydraulic fluid composition 100 to the cylinder ports 11a and 11b, respectively, and the opening 28b between the supply ports 27a and 27b is formed in the spool valve body 24. It is an inlet for introducing the object 100.

  In the servo valve 4 having the above-described configuration, when the flapper 22 is stationary in the center between the nozzles 23a and 23b, the pressure of the hydraulic fluid composition 100 flowing through the nozzles 23a and 23b is equal. The hydraulic pressure applied to the partition members 25b and 25c is equal, so that the spool 25 is located in the center of the sleeve 24. At this time, the introduction port 28b is closed by the partition member 25a at the center of the spool 25, and the hydraulic fluid composition 100 is not supplied to any of the supply ports 27a and 27b.

  Next, when the torque motor 21 is operated to move the flapper 22 closer to the nozzle 23a (to the left side of the page), the hydraulic pressure at the outlet of the nozzle 23a approaching the flapper 22 is higher than that at the outlet of the nozzle 23b. . As the hydraulic pressure changes, the hydraulic pressure applied to the partition member 25b at the end of the spool 25 becomes greater than the hydraulic pressure applied to the partition member 25c, so the spool 25 moves to the right side of the page. Then, when the partition member 25a moves to the right side, the introduction port 28b is opened, the hydraulic fluid composition 100 is introduced into the space between the partition members 25a and 25b, and further from the supply port 27a to the cylinder port 11a. Supplied. As a result, the hydraulic pressure in the cylinder port 11a increases and the piston head 9 and the rod 10 move to the right.

  Similarly, when the flapper 22 is moved closer to the nozzle 23b, the hydraulic pressure at the outlet of the nozzle 23b, that is, the hydraulic pressure applied to the partition member 25c at the end of the spool 25 increases, so that the spool moves to the left side of the page. Then, the hydraulic fluid composition 100 is supplied to the cylinder port 11b from the introduction port 28b through the space between the partition members 25a and 25c and the supply port 27b, and the hydraulic pressure in the cylinder port 11b is increased, and the piston head 9 and The rod 10 moves to the left.

  Thus, when the piston in the cylinder 3 is reciprocated, it is possible to improve the performance of the hydraulic machine by speeding up the operation of the spool 25 by speeding up the operation of the flapper 22.

At this time, in the servo valve 4, by increasing the speed of the operation of the spool 25, a large shear stress is applied to the hydraulic fluid composition 100 existing between the partition members 25a to 25c and the inner wall surface of the spool valve body 24. Is added. Further, a large shear stress is applied to the hydraulic fluid composition 100 even at the sliding portion of the hydraulic pump 2 and the cylinder 3. These shear stresses are 10 ⁻² S ⁻¹ or more in order to achieve sufficiently high performance of the hydraulic operation system, 10 ⁻³ S ⁻¹ or more, and 10 in order to achieve further high performance. ^-4 S ^-1 or more.

  As described above, when a conventional hydraulic fluid is used under such a high shear condition, an organic acid such as formic acid is generated, and rust and sludge are easily generated and the hydraulic fluid is liable to deteriorate. On the other hand, in the present invention, by using the hydraulic fluid composition of the present invention which is excellent in all of heat / oxidation stability, rust prevention property, sludge generation prevention property and wear resistance, generation of rust and sludge, hydraulic pressure The deterioration of the hydraulic oil can be prevented, and the high-performance hydraulic machine can be stably operated.

  In addition, this invention is not limited to said embodiment. For example, FIG. 1 shows a hydraulic machine having an electro-hydraulic servo valve 4, but the servo mechanism of the servo valve 4 is mechanical, electric, pneumatic, hydraulic, mechanical-pneumatic, mechanical-hydraulic. An electric-pneumatic type or the like may be used.

  In the present invention, a spool valve may be used instead of the servo valve 4 as a control valve. FIG. 3 is a schematic cross-sectional view showing an example of a spool valve. The configuration of the spool valve shown in FIG. 3 is the same as that of the spool valve 24 provided in the servo valve 4 shown in FIG. That is, when the spool 25 moves left and right inside the spool valve body 24, the introduction port 28b is opened and closed, and the hydraulic fluid composition 100 introduced from the introduction port 28b is supplied from the supply ports 27a and 27b to the cylinder ports 11a and 11b. To be supplied.

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

[Examples 1-8, Comparative Examples 1-5]
In Examples 1 to 8 and Comparative Examples 1 to 5, hydraulic pressures having the compositions shown in Table 1 or 2 using the base oil, rust inhibitor, antioxidant, antiwear agent and other additives shown below, respectively. A hydraulic oil composition was prepared.

(Base oil)
Base oil 1: Paraffin-based highly solvent refined base oil (kinematic viscosity at 40 ° C .: 46.1 mm ² / s, viscosity index: 100)
Base oil 2: Paraffinic hydrocracked base oil (kinematic viscosity at 40 ° C .: 46.1 mm ² / s, viscosity index: 125).

(Rust inhibitor)
Ashless rust preventive agent A1: dodecenyl succinic acid diethylenetriamine salt (total base number: 8 mgKOH / g)
Ashless rust inhibitor A2: oleylamine (total base number: 18 mgKOH / g)
Ashless rust inhibitor A3: amide of oleic acid and methylamine (total base number: 22 mgKOH / g)
Ashless rust inhibitor A4: Alkenyl succinic acid half ester rust inhibitor (total base number 0 mgKOH / g)
Ashless rust inhibitor A5: sorbitan monooleate (total base number: 0 mgKOH / g)
Metal rust inhibitor A6: Ca dinonyl naphthalene sulfonate (total base number 0 mg KOH / g).

(Antioxidant)
Ashless antioxidant B1: Di-tertbutyl-p-cresol Ashless antioxidant B2: Dioctyldiphenylamine Metal antioxidant B3: Zinc di-2-ethylhexyl dithiophosphate.

(Antiwear agent)
Ashless antiwear agent C1: tricresyl phosphate Sulfur antiwear agent C2: isopropylthiophosphate (other additives)
Pour point depressant D1: Polymethacrylate pour point depressant Antifoam E1: Silicone defoamer.

  Next, the following tests were performed on the hydraulic fluid compositions of Examples 1 to 8 and Comparative Examples 1 to 5.

(Rust prevention test under formic acid generation conditions)
Using a test body defined in JIS K 2246, 5.39 “Testing Method for Vaporization and Rust Prevention”, a rust prevention test was performed under the formic acid generation condition according to the following procedure.

  First, in the method stipulated in JIS K 2246 5.39 “Vaporizable rust preventive test method”, each hydraulic fluid composition was put in place of the data (vaporizable rust preventive oil), and the steel test A specimen was prepared according to the method defined by the copper test method, except that the polished part (the part where rust was observed) of the piece was immersed in each hydraulic fluid composition and then fixed to the rubber stopper.

  The obtained specimen was placed in a tank of an ultrasonic generator installed at room temperature, and left for 12 hours under ultrasonic conditions (frequency 40 kHz). Thereafter, the polished portion of the steel test piece was observed by a method defined in the copper test method to determine whether or not rust was generated. The obtained results are shown in Tables 1 and 2. It has been separately confirmed that formic acid is generated from each hydraulic fluid composition under the above ultrasonic conditions.

(JIS K 2510 rust prevention test)
A rust prevention test was conducted in accordance with the “rust prevention performance test method” prescribed in JIS K 2510, and the rust prevention properties of each hydraulic fluid composition were evaluated. The obtained results are shown in Tables 1 and 2. In this test, artificial seawater was used as a reagent.

(Thermal stability test)
A thermal stability test was conducted in accordance with the “lubricating oil thermal stability method” defined in JIS K 2540. Specifically, 50 ml of the hydraulic fluid composition was sampled in a beaker having a capacity of 50 ml, and a coiled catalyst of iron and copper was added and held in an air constant temperature bath at 140 ° C. for a certain period. The sample oil after 10 days or 20 days from the start of the test was filtered with a filter, and the amount of generated sludge was measured. The obtained results are shown in Tables 1 and 2.
"Vane pump test"
A vane pump test defined in ASTM D 2882 was conducted, and the amount of wear was measured by measuring the weight of the vane and the ring before and after the test. The obtained results are shown in Tables 1 and 2. The test time in this test was 100 hours.

表１に示したように、実施例１〜８の各油圧作動油組成物は、ギ酸発生条件での厳しい防錆試験であっても極めて良好な防錆性と熱安定性を有しており、さらに耐摩耗性にも優れていることが確認された。

As shown in Table 1, the hydraulic fluid compositions of Examples 1 to 8 have extremely good rust prevention properties and thermal stability even in severe rust prevention tests under formic acid generation conditions. In addition, it was confirmed that the wear resistance is also excellent.

  On the other hand, as shown in Table 2, each of the hydraulic fluid compositions of Comparative Examples 1 to 5 was insufficient in any of rust prevention, thermal stability, and wear resistance. In particular, in the hydraulic fluid compositions of Comparative Examples 1, 2, and 4, no rust was observed in the JIS K 2510 rust prevention test, but rust was generated in the rust prevention test under the formic acid generation condition. Was recognized. In the case of Comparative Example 6 using zinc di-2-ethylhexyl dithiophosphate, although the antirust property was relatively good, the thermal stability was insufficient.

It is a schematic cross section showing an example of a hydraulic operation system. It is a schematic cross section which shows an example of a servo valve. It is a schematic cross section which shows an example of a spool valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Hydraulic pump, 3 ... Cylinder, 4 ... Servo valve, 5 ... Electric motor, 6 ... Suction filter, 7 ... Pressure gauge, 8 ... Filter, 9 ... Piston head, 10 ... Rod, 11a, 11b ... Cylinder Port, 20 ... nozzle flapper, 21 ... torque motor, 22 ... flapper, 23a, 23b ... nozzle, 24 ... spool valve, 25 ... spool, 25a, 25b, 25c ... partition member, 26a, 26b ... rod, 27a, 27b ... supply Mouth, 28a, 28b ... introduction port, 29 ... discharge port.

Claims (3)

At least one selected from mineral oil, fats and oils and synthetic oils is used as a base oil, and the following (A) to (C):
(A) Ashless rust preventive agent having a total base number of 2 to 100 mgKOH / g 0.01 to 2% by mass
(B) Ashless antioxidant 0.01-2 mass%
(C) Ashless antiwear agent 0.005-5 mass%
And a hydraulic fluid composition characterized by containing substantially no zinc dithiophosphate. 2. The hydraulic fluid composition according to claim 1, wherein the hydraulic fluid composition is used in a hydraulic machine having a portion where a shear stress applied to the hydraulic fluid is 10 ³ S ⁻¹ or more. The hydraulic fluid composition according to claim 1 is used as the hydraulic fluid when operating the hydraulic fluid system having a portion where the shear stress applied to the hydraulic fluid is 10 ³ S ^-1 or more. Actuation method of hydraulic actuation system.

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