WO2010064347A1

WO2010064347A1 - Flame retardant hydraulic oil composition

Info

Publication number: WO2010064347A1
Application number: PCT/JP2009/004519
Authority: WO
Inventors: 三本信一
Original assignee: 新日本石油株式会社
Priority date: 2008-12-01
Filing date: 2009-09-11
Publication date: 2010-06-10
Also published as: JPWO2010064347A1; CN102292424A; CN102292424B; JP5389048B2

Abstract

As a flame retardant hydraulic oil composition which is most suitable for use at a place where the risk of fire breakout is high under high-temperature and high-pressure conditions, can be applied to a high-pressure pump, has high wear resistance, seize resistance, and sludge inhibiting performance, and can be used for a long period of time, a flame retardant hydraulic oil composition containing (A) at least one base oil selected from hydrocarbon oils, synthetic esters, oils and fats; (B) a carbodiimide compound represented by formula (1) and/or an epoxy compound in an amount of 0.01 to 2% by mass based on the total amount of the composition; and (C) at least one anti-wear agent selected from sulfur-containing phosphoric acid esters, acidic phosphoric acid esters, acidic phosphoric acid ester amine salts, and phosphorous acid esters in an amount of 0.001 to 5% by mass based on the total amount of the composition is provided.

Description

Flame retardant hydraulic fluid composition

The present invention relates to a flame retardant hydraulic fluid composition, particularly high risk of fire occurrence, such as aluminum die-cast extrusion machine or steelworks premises work, optimal for use in high temperature and high pressure, and high pressure A flame-retardant hydraulic fluid composition that is applicable to pumps, has long life, sludge suppression performance, wear resistance, and seizure resistance, and is particularly resistant to hydrolysis and can be used for a long period of time. About.

Conventionally, hydraulic fluids used in places where there is a high risk of fire, such as aluminum die-cast extrusion processing machines or steelworks premises work, are made of flame retardant hydraulic fluids such as water glycols or fatty acid esters (liquids). ) Has been used. Among them, water glycol-based hydraulic oil has been mainly used in places where there is a restriction on the fourth petroleum of the Fire Service Act, but it has drawbacks in terms of the complexity of use liquid management and wear resistance. However, as a result of the revision of the Fire Service Act in 2002, hydraulic oils based on fatty acid esters with a flash point of 250 ° C. or higher have been exempted from the Fire Service Act, and their uses have expanded.

The performance of the fatty acid ester varies depending on the composition of the fatty acid constituting the ester, and the ester of a saturated fatty acid is superior in terms of oxidation stability. However, saturated fatty acids are expensive because they are produced by synthesizing from petroleum raw materials or hydrogenating unsaturated fatty acids obtained from animal and vegetable oils, and are not friendly to the global environment. Therefore, natural synthetic esters and fats and oils using fatty acids mainly composed of unsaturated fatty acids obtained from animal and plant oils that are environmentally friendly and advantageous in terms of cost are also used (Patent Documents 1 to 4). 3).

On the other hand, the hydraulic system has recently been increased in pressure and maintenance-free, and hydraulic oils used in such an environment have been required to have long life and excellent wear resistance. The biggest drawback was that it was hydrolyzed in the presence of moisture. The acid generated by hydrolysis promotes corrosion of various metals and wear at the sliding portion, and thus adversely affects not only the life but also the wear resistance. In this hydrolysis, metal or the like acts as a catalyst, but the acid itself generated by hydrolysis can act as a catalyst. Capturing and detoxifying is extremely important.
Natural synthetic esters made from natural raw materials are unsaturated fatty acids, and the fatty acids are mainly environmentally friendly and cost-effective. It was a disadvantage that it was greatly inferior to other hydrocarbon oils.
Synthetic esters and vegetable fats and oils contain impurity acids at the new oil stage, which trigger hydrolysis and oxidative degradation, so the use of acid scavengers that capture these acids greatly increases the degradation life. Extension is possible. As this acid scavenger, carbodiimide compounds and epoxy compounds are known (for example, see Document 4).

However, when these acid scavengers are used alone, they are known to have an adverse effect on abrasion resistance, and typical phosphorus-based antiwear agents used in hydraulic fluids such as tricresyl phosphate are blended. However, the wear resistance was not improved.
In addition, esters composed of unsaturated fatty acids have poor oxidation stability, but conventional phenolic antioxidants and amine antioxidants that have been used in hydrocarbon oils alone are sufficient to oxidize those ester oils. The prevention effect was not obtained.

JP 2001-214187 A Japanese Patent No. 3548591 Japanese Patent No. 2888747 JP 2001-316687 A

Natural synthetic ester hydraulic fluids using fatty acids mainly composed of unsaturated fatty acids obtained from animal and vegetable oils that are environmentally friendly and cost-effective are inferior in hydrolytic stability, oxidation stability or wear resistance. Yes. For this reason, it is necessary to quickly capture and detoxify the acid that is generated in the initial stage, but if an acid scavenger is used alone, it will adversely affect the wear resistance. . Moreover, since the ester which consists of unsaturated fatty acid has bad oxidation stability, the combination of the additive from which the antioxidant effect outstanding from the past is acquired is required.

The present invention has been made in view of such circumstances, and in synthetic esters or animal and vegetable oils and fats obtained from raw materials mainly composed of unsaturated fatty acids, it has sufficient antioxidant performance and wear resistance. As a result of diligent research aimed at providing a long-life, flame-retardant hydraulic fluid that is compatible with high-pressure and maintenance-free hydraulic systems, it is obtained from hydrocarbon oils, synthetic esters and / or oils, especially natural raw materials. The present inventors have found that the above-mentioned problems can be solved by blending a specific acid scavenger and a specific phosphorus compound with a synthetic ester containing an unsaturated fatty acid as a main component, and have completed the present invention.

That is, the present invention comprises (A) at least one base oil selected from hydrocarbon oils, synthetic esters and fats and oils, (B) an epoxy compound and / or a carbodiimide compound represented by the following general formula (1). 0.01 to 2% by mass in total on the basis, and (C) at least one type of antiwear agent selected from sulfur-containing phosphate ester, acidic phosphate ester, acidic phosphate ester amine salt and phosphite ester A flame-retardant hydraulic fluid composition characterized by containing 0.001 to 5% by mass based on the total amount of substances.

(In the formula (1), R ¹ and R ² represent an alkyl group having 4 to 26 carbon atoms, an (alkyl) phenyl group, an aralkyl group, or an (alkyl) cycloalkyl group, which may be the same or different. .)

The present invention also provides the flame retardant hydraulic fluid composition as described above, wherein the carbodiimide compound represented by the general formula (1) is a compound represented by the following general formula (2).

(In formula (2), R ³ to R ⁸ represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and may be the same or different.)

Furthermore, the present invention provides the flame retardant hydraulic fluid composition as described above, which contains 0.01 to 5% by mass of an amine-based antioxidant and / or a phenol-based antioxidant based on the total amount of the composition. is there.

According to the present invention, it is possible to provide a flame-retardant hydraulic fluid composition excellent in oxidation resistance stability and wear resistance, particularly in fatty acid ester oils mainly composed of unsaturated fatty acids. In addition, it is possible to provide a flame retardant hydraulic fluid composition having a failure stage of 10 or more in the FZG gear test.

Hereinafter, preferred embodiments of the present invention will be described in detail.
As the base oil used in the flame retardant hydraulic fluid composition of the present invention, at least one selected from hydrocarbon oils, synthetic esters and fats and oils can be used as a base oil, specifically, polyol. Examples include esters, diesters, various vegetable oils and fats, animal fats and the like. Among them, esters such as polyol esters, rapeseed oil, sunflower oil, soybean oil and the like having a high oleic acid ratio are preferable, and those having a kinematic viscosity at 40 ° C. of 10 to 200 mm ² / s are particularly preferable.

The hydrocarbon oil used in the present invention includes mineral oil and synthetic hydrocarbon oil. Specific examples include synthetic hydrocarbon oils such as naphthenic or paraffinic mineral oils, olefin polymers, naphthalene compounds, alkylbenzenes, or mixtures of two or more thereof.

Mineral oils include solvent removal, solvent extraction, hydrocracking, solvent removal from lubricating oil fractions obtained by atmospheric distillation and vacuum distillation of paraffinic, intermediate or naphthenic crudes. Mention may be made of paraffinic or naphthenic mineral oils obtained by applying a suitable combination of one or more purification means such as dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment.

Among these mineral oils, it is preferable to use highly refined mineral oil from the viewpoint of superior stability. The highly refined mineral oils used in the present invention,% _{C A} of 2 or _less,% _C P /% C _N is 6 or more, an iodine value of 2.5 or more is preferable. In the present invention,% C _P ,% C _N, and% C _A are the total number of paraffin carbons determined by a method (ndM ring analysis) based on ASTM D 3238-85, respectively. It means percentage, percentage of naphthene carbon number to total carbon number, and percentage of aromatic carbon number to total carbon number.
Moreover, it is preferable that a non-aromatic unsaturated part (unsaturation degree) is 10% or less. If this degree of unsaturation is more than 10%, sludge may be generated. From this point, in the present invention, the degree of unsaturation is more preferably 5% or less, further preferably 1% or less, and most preferably 0.1% or less. Specific examples of such highly refined mineral oil include, for example, a distillate obtained by atmospheric distillation of paraffinic crude oil, intermediate crude oil or naphthenic crude oil, or distillation of residual oil of atmospheric distillation under reduced pressure. Examples include refined oil obtained by refining oil according to a conventional method, deep dewaxed oil obtained by further deep dewaxing after refining, and hydrotreated oil obtained by hydrotreatment. . In this case, the purification method is not particularly limited, and various methods are used.

Examples of the olefin polymer include those obtained by polymerizing olefins having 2 to 12 carbon atoms, and those obtained by subjecting this to hydrogenation treatment. Specific examples include polybutene, polyisobutene, α having 5 to 12 carbon atoms, and the like. Olefin oligomers (poly α-olefins), ethylene-propylene copolymers, and those obtained by hydrogenating these are preferably used.

The naphthalene compound is not particularly limited as long as it has a naphthalene skeleton, but a naphthalene compound represented by the following general formula (3) is preferable.

In the general formula (3), R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms. . Examples of the hydrocarbon group herein include an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, and an aralkyl group. The total carbon number of R ⁹ , R ¹⁰ , R ¹¹ and R ¹² is preferably 1 to 10.
As a naphthalene compound, not only a compound having a single structure but also a mixture of two or more compounds having different structures may be used.
Moreover, the manufacturing method of the said naphthalene compound is not restrict | limited in particular, Although it can manufacture by various well-known methods, the thing whose sulfur content is 500 mass ppm or less is used preferably from the point which is excellent in thermal and oxidation stability.

Any alkylbenzene can be used as long as the performance as a hydraulic fluid is not impaired. Of these, alkylbenzene having 1 to 4 alkyl groups having 1 to 30 carbon atoms and a total carbon number of the alkyl groups of 20 to 30 is more preferable.
The alkyl group may be linear or branched, but a branched alkyl group is preferable from the viewpoint of stability, viscosity characteristics, etc., and propylene, Branched alkyl groups derived from olefin oligomers such as butene and isobutylene are more preferred.

The alkylbenzene has 1 to 4 alkyl groups. From the viewpoints of stability and availability, alkylbenzene having 1 or 2 alkyl groups, that is, monoalkylbenzene, dialkylbenzene, or a mixture thereof may be used. Most preferably used.
The alkylbenzene may be a mixture of two or more alkylbenzenes having different structures as well as a single structure.
The manufacturing method of the said alkylbenzene is arbitrary and is not limited at all.

Examples of synthetic esters include fatty acid esters, dibasic acid esters, polyol esters, complex esters, aromatic esters, carbonate esters, and mixtures thereof.

Fatty acid esters include palmitoleic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, 8,11-icosadienoic acid and other unsaturated fatty acids, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonane Saturated fatty acid having a linear or branched alkyl group having 5 to 19 carbon atoms such as acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, and nonadecanoic acid And methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol , Octadecanol, esters and mixtures thereof with monohydric alcohols having a carbon number of 119 with a straight-chain or branched alkyl group nonadecanol is preferably used. Specifically, fatty acid esters such as oleyl stearate and oleyl laurate are preferred. *

Examples of the dibasic acid ester include dibasic acids having 5 to 10 carbon atoms such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid, and linear or branched alkyl groups described in the fatty acid ester. And esters of monohydric alcohols having 1 to 15 carbon atoms and mixtures thereof are more preferably used. More specifically, for example, ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, diester -2-ethylhexyl sebacate, and mixtures thereof.

As the polyol ester, an ester of a diol or a polyol having 3 to 20 hydroxyl groups and a fatty acid having 1 to 24 carbon atoms is preferably used.
Specific examples of the diol include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5 -Pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propane Diol, 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, etc. Is mentioned.

Specific examples of the polyol include, for example, trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, di- (pentaerythritol), tri- (Pentaerythritol), glycerin, polyglycerin (glycerin 2-20 mer), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensate, polyhydric alcohols such as adonitol, arabitol, xylitol, mannitol, Xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffino Scan, gentianose, sugars such as melezitose, and their partially etherified products and methyl glucosides (glycosides) and the like.
Among these, polyols are superior in hydrolytic stability, so neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), penta Hindered alcohols such as erythritol and di- (pentaerythritol) are preferred.

Examples of the fatty acid of the polyol ester include unsaturated fatty acids described in the fatty acid esters, and saturated fatty acids having a linear or branched alkyl group having 5 to 19 carbon atoms, and particularly unsaturated fatty acids described in the fatty acid esters. Is preferably used. Or the neo acid etc. whose (alpha) carbon atom is quaternary are mentioned. Specific examples of branched saturated fatty acids include isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, and the like. Can be mentioned.

Specific examples of preferred polyol esters include valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, and 2-ethylhexanoic acid. A diester of one or more fatty acids selected from 3,5,5-trimethylhexanoic acid and each polyol of neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane and pentaerythritol, Triesters and tetraesters are mentioned.
The ester of two or more fatty acids and a polyol may be a mixture of two or more esters of one fatty acid and a polyol, or may be an ester of two or more mixed fatty acids and a polyol.

Among the polyol esters, since they are more excellent in hydrolysis stability, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), penta More preferred are esters of hindered alcohols such as erythritol, di- (pentaerythritol), tri- (pentaerythritol), and even more preferred are esters of neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane and pentaerythritol. The ester of trimethylolpropane and pentaerythritol is most preferred because it is particularly excellent in hydrolysis stability. Specifically, trimethylolpropane oleate, pentaerythritol oleate and the like are preferably used.

The polyol ester may be a partial ester in which some hydroxyl groups remain without esterification of all hydroxyl groups of the polyol, or may be a complete ester in which all hydroxyl groups are esterified, A mixture of a partial ester and a complete ester may be used, but a complete ester is preferred.

The complex ester is an ester of a fatty acid and a dibasic acid, and a monohydric alcohol and a polyol. The fatty acid, the dibasic acid, the monohydric alcohol, and the polyol are described with respect to the dibasic acid ester and the polyol ester. The thing similar to what was illustrated in can be used.

Examples of the aromatic ester include esters of 1 to 6 valent, preferably 1 to 4 valent, more preferably 1 to 3 valent aromatic carboxylic acid and aliphatic alcohol having 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms. Is used. Specific examples of the monovalent to hexavalent aromatic carboxylic acid include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and mixtures thereof. Examples of the aliphatic alcohol having 1 to 18 carbon atoms include monohydric alcohols having 1 to 15 carbon atoms and linear or branched hexadecanol having a linear or branched alkyl group described in the fatty acid ester. , Linear or branched heptadecanol, linear or branched octadecanol, and mixtures thereof.
Specific examples of aromatic esters include dibutyl phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, didodecyl phthalate, ditridecyl phthalate, tributyl trimellitic acid, trimethyl trimellitic acid ( 2-ethylhexyl), trinonyl trimellitic acid, tridecyl trimellitic acid, tridodecyl trimellitic acid, tritridecyl trimellitic acid, and the like. Of course, when a divalent or higher valent aromatic carboxylic acid is used, it may be a simple ester composed of one kind of aliphatic alcohol or a complex ester composed of two or more kinds of aliphatic alcohol. May be.

The carbonate ester is a compound having a carbonate ester structure in the molecule. One carbonate ester structure or a plurality of carbonate ester structures may be included in one molecule.
As alcohol which comprises carbonate ester, the above-mentioned aliphatic alcohol, polyol, etc. can be used, and what added polyglycol to polyglycol and polyol can also be used. Moreover, you may use what used carbonic acid and a fatty acid, and / or a dibasic acid.

As a matter of course, the ester referred to in the present invention may be a single ester having a single structure or a mixture of two or more esters having different structures.
Among these ester base oils, a polyol ester is preferable because of excellent hydrolysis stability.
In the present invention, one of the ester base oils may be used alone, or two or more may be used in combination.

Examples of the oil used as the base oil of the flame retardant hydraulic fluid composition of the present invention include natural animal and vegetable oils and fats, such as rapeseed oil, sunflower oil, soybean oil, castor oil, coconut oil, corn oil, and cottonseed oil. Olive oil, rice bran oil, coconut oil, palm oil, palm kernel oil, peanut oil, tall oil, beef tallow, lard, or hydrogenated products thereof. Among the oils and fats, hyoleic acid type fats and oils having a high proportion of unsaturated fatty acids, particularly oleic acid, among fatty acids constituting the ester are preferable, and hyoleinized vegetable oil having a higher proportion of oleic acid is more preferable.

As the base oil of the flame retardant hydraulic oil composition of the present invention, one kind selected from the group consisting of the above-described mineral oil, synthetic hydrocarbon, synthetic ester and oil and fat may be used alone, or a combination of two or more kinds may be used. May be used.

In the synthetic ester and / or fat and oil, the constituent fatty acid may be a saturated fatty acid, an unsaturated fatty acid, a linear fatty acid, or a branched fatty acid, and is represented by the formula (1) of the component (B). From the addition effect of an acid scavenger of a carbodiimide compound or an epoxy compound, it is preferable to contain an unsaturated fatty acid. The ratio of the unsaturated fatty acid to the fatty acid constituting the ester is 30 mol% or more, preferably 50 mol% or more, more preferably 70 mol% or more.
When the ratio of unsaturated fatty acid in the fatty acid constituting the ester is less than 30 mol%, even if the component (B) is blended, the effect of suppressing the increase in viscosity and the increase in acid value is obtained at the initial stage of use of the hydraulic fluid. However, as the use proceeds, the deteriorated product tends to become sludge suddenly, and troubles may occur in the hydraulic system.

The kinematic viscosities of these base oils are not particularly limited and are arbitrary, but are usually 40 from the viewpoints of excellent flame retardancy, wear resistance, seizure resistance, and low friction loss due to stirring resistance. The kinematic viscosity at 0 ° C. is preferably 10 to 200 mm ² / s, more preferably 15 to 150 mm ² / s, and still more preferably 20 to 100 mm ² / s. The viscosity index is arbitrary, but from the viewpoint of maintaining an oil film at a high temperature, the viscosity index is usually preferably from 80 to 500, more preferably from 100 to 300. The pour point is also arbitrary, but is preferably −5 ° C. or lower, more preferably −15 ° C. or lower, from the viewpoint of pump startability in winter.

R ¹ and R ² of the carbodiimide compound represented by the following general formula (1), which is the component (B) in the flame retardant hydraulic oil composition of the present invention, are an alkyl group, a phenyl group, an alkylphenyl group, an aralkyl group, a cyclo A paraffin group or an alkylcycloparaffin group, each of which may be the same or different;

The alkyl group is preferably a linear or branched alkyl group having 4 to 26 carbon atoms, more preferably a linear or branched alkyl group having 4 to 12 carbon atoms, such as a butyl group or a pentyl group. Hexyl group, octyl group and the like.
When R ¹ and R ² are alkylphenyl groups, examples of the compound represented by the general formula (1) include diphenylcarbodiimide or dialkylphenylcarbodiimide represented by the following general formula (2). In general formula (2), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and may be the same or different.
Examples of the cycloparaffin group and the alkylcycloparaffin group include those in which the phenyl group is replaced with a cyclohexyl group in the dialkylphenylcarbodiimide.

Among the compounds represented by the general formula (1), R ¹ and R ² are an alkylphenyl group, particularly an ethyl group or a branched alkyl group having 3 to 4 carbon atoms because a better acid scavenging effect can be obtained. Preferred are phenyl groups with, for example, diisopropylphenyl group and ditertiarybutylphenyl group, and specific examples include bis (2,6-di-tert-butylphenyl) carbodiimide.
In addition, R ¹ and R ² each preferably have 4 to 26 carbon atoms, more preferably 4 to 20 carbon atoms, and still more preferably 4 to 12 carbon atoms. When R ¹ or R ² has 3 or less carbon atoms, the reactivity becomes high and unstable, which is not preferable, and when it is 27 or more, the proportion of functional groups in the molecule decreases, which adversely affects the acid supplementation effect. There is a risk of giving.

As the epoxy compound of component (B), alkyl oxirane compounds, allyl oxirane compounds, phenyl glycidyl ether type epoxy compounds, alkyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, alicyclic epoxy compounds, epoxidized fatty acid monoesters and At least one epoxy compound selected from epoxidized vegetable oils can be used.

The alkyl group of the alkyloxirane compound is a linear or branched alkyl group having 4 to 20 carbon atoms, preferably an alkyl group having 8 to 20 carbon atoms, and more preferably an alkyl group having 10 to 18 carbon atoms. When the carbon number of the alkyl group is 3 or less, it tends to evaporate and lacks stability. On the other hand, when the carbon number of the alkyl group is 21 or more, the low temperature performance and solubility, particularly the solubility after acid capture, are poor.

Specific examples of the alkyloxirane compound include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1,2- Epoxy nonane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1,2- Examples thereof include epoxyhexadecane, 1,2-epoxyheptadecane, 1,1,2-epoxyoctadecane, 2-epoxynonadecane, and 1,2-epoxyicosane.

Specific examples of the allyloxirane compound include 1,2-epoxystyrene and alkyl-1,2-epoxystyrene.

Specific examples of the phenyl glycidyl ether type epoxy compound include phenyl glycidyl ether and alkylphenyl glycidyl ether. Examples of the alkylphenyl glycidyl ether herein include those having 1 to 3 alkyl groups having 1 to 13 carbon atoms, and those having one alkyl group having 4 to 10 carbon atoms, such as n-butylphenyl glycidyl. Ether, i-butylphenyl glycidyl ether, sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl ether, pentylphenyl glycidyl ether, hexylphenyl glycidyl ether, heptylphenyl glycidyl ether, octylphenyl glycidyl ether, nonylphenyl glycidyl ether, decylphenyl A glycidyl ether etc. can be illustrated as a preferable thing.

Specific examples of the alkyl glycidyl ether type epoxy compound include decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl ether, Examples thereof include trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ether, and polyalkylene glycol diglycidyl ether.

Specific examples of the glycidyl ester type epoxy compound include phenyl glycidyl ester, alkyl glycidyl ester, alkenyl glycidyl ester and the like, and preferred are glycidyl-2,2-dimethyloctanoate, glycidyl benzoate, glycidyl acrylate. And glycidyl methacrylate.

Specific examples of the alicyclic epoxy compound include 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis (3,4 -Epoxycyclohexylmethyl) adipate, exo-2,3-epoxynorbornane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 2- (7-oxabicyclo [4.1.0] hept-3- Yl) -spiro (1,3-dioxane-5,3 ′-[7] oxabicyclo [4.1.0] heptane, 4- (1′-methylepoxyethyl) -1,2-epoxy-2-methyl Examples include cyclohexane and 4-epoxyethyl-1,2-epoxycyclohexane.

Specific examples of the epoxidized fatty acid monoester include esters of an epoxidized fatty acid having 12 to 20 carbon atoms with an alcohol or phenol having 1 to 8 carbon atoms or an alkylphenol. In particular, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters of epoxy stearate are preferably used.

Specific examples of the epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil and cottonseed oil.

Among these epoxy compounds, preferred are alkyl oxirane compounds, phenyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, alicyclic epoxy compounds and epoxidized fatty acid monoesters. Of these, alkyl oxirane compounds, phenyl glycidyl ether type epoxy compounds and glycidyl ester type epoxy compounds are more preferred, and 1,2-epoxytetradecane, phenyl glycidyl ether, butylphenyl glycidyl ether, alkyl glycidyl esters or mixtures thereof are particularly preferred.

The upper limit of the content of the component (B) in the flame retardant hydraulic fluid composition of the present invention is 2% by mass, preferably 1.5% by mass, more preferably 1.0% by mass based on the total amount of the composition. %. When the content exceeds 2% by mass, the solubility after acid trapping is inferior, causing sludge generation, which is not preferable. On the other hand, the lower limit of the content of component (B) is 0.01% by mass, preferably 0.05% by mass, 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 acid scavenging effect is insufficient, which is not preferable.

The flame-retardant hydraulic fluid composition of the present invention has at least one selected from the group consisting of a sulfur-containing phosphate ester, an acidic phosphate ester, an acidic phosphate amine salt, and a phosphite ester as the component (C). Contains various types of antiwear agents.

Specific examples of the sulfur-containing phosphate ester include trialkyl phosphorothioate, trioleyl phosphorothioate, triphenyl phosphorothioate, tricresyl phosphorothioate having an alkyl group of 4 to 18 carbon atoms. , Trixylenyl phosphorothioate, cresyl diphenyl phosphorothioate, xylenyl diphenyl phosphorothioate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phosphorothioate, tris (N-butylphenyl) phosphothionate, tris (isobutylphenyl) phosphothionate, tris (s-butylphenyl) phosphothionate, tris (t-butylphenyl) phosphothionate, etc. It is.

Specific examples of acidic phosphate esters include alkyl acid phosphates and dioleyl acid phosphates having an alkyl group of 4 to 22 carbon atoms, diphenyl acid phosphates and dicresyl ester acid phosphates which are aromatic acid phosphate esters. Fate etc. are mentioned. Of these, dialkyl acid phosphates that do not contain aromatics and have an alkyl group with 4 to 22 carbon atoms are preferred, and dialkyl acid phosphates with an alkyl group with 6 to 18 carbon atoms are more preferred.

Specifically, the acid phosphate ester amine salt includes the acid phosphate ester, an amine having an alkyl group having 1 to 8 carbon atoms, an amine having two alkyl groups having 1 to 8 carbon atoms, and the number of carbon atoms. Examples thereof include salts with amines selected from amines having 3 alkyl groups of 1-8.

Specific examples of the phosphite ester include dialkyl phosphites, dioleyl phosphites, diphenyl phosphites, dicresyl phosphites having 4 to 12 carbon atoms, and alkyl groups having 4 to 12 carbon atoms. And trialkyl phosphites, trioleyl phosphites, triphenyl phosphites, and tricresyl phosphites.

As the component (C) used in the present invention, sulfur-containing phosphate esters, acidic phosphate esters, and acidic phosphate ester amine salts are preferably used because of their high effects in synthetic esters and fats and oils.

The upper limit of the content of the component (C) in the flame-retardant 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. is there. 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 the component (C) is 0.001% by mass, preferably 0.005% by mass, more preferably 0.01% by mass based on the total amount of the composition. When the content of the component (C) is less than 0.001% by mass, the wear resistance and seizure resistance are insufficient, which is not preferable.

The flame retardant hydraulic fluid composition of the present invention preferably further contains an amine-based antioxidant and / or a phenol-based antioxidant. By using an antioxidant in combination, higher antioxidant properties and sludge suppression properties can be added. As the antioxidant, any amine compound or phenol used as an antioxidant for lubricating oil can be used, and it is not particularly limited.

Representative amine antioxidants include phenyl-α-naphthylamines represented by the following formula (4) or p, p'-dialkylated diphenylamine represented by the following formula (5).

In the general formula (4), R ¹³ represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms.
In the general formula (5), R ¹⁴ and R ¹⁵ each independently represents an alkyl group having 1 to 16 carbon atoms.

Among the compounds represented by the general formula (4), when R ¹³ is an alkyl group, a more excellent sludge generation suppressing effect can be obtained. Therefore, R ¹³ is a branched alkyl group having 8 to 16 carbon atoms. Further, 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 propylene or isobutylene is preferable in order to obtain a more excellent sludge formation suppressing effect. In order to obtain a further excellent sludge production inhibitory effect, R ¹³ represents a branched octyl group derived from an isobutylene dimer, a branched nonyl group derived from a propylene trimer, and an isobutylene trimer. A branched dodecyl group derived from a propylene tetramer, a branched dodecyl group derived from a propylene tetramer, or a branched pentadecyl group derived from a propylene pentamer is more preferred, and a branch derived from a dimer of isobutylene. A branched dodecyl group derived from a branched octyl group, a trimer of isobutylene or a branched dodecyl group derived from a tetramer of propylene is more preferred, and a branched dodecyl group is most preferred.

R ¹⁴ and R ¹⁵ of p, p′-dialkyldiphenylamine represented by the general formula (5) are each independently a branched alkyl group having 3 to 16 carbon atoms in order to obtain a more excellent sludge generation inhibiting effect. Further, a branched alkyl group having 3 to 16 carbon atoms derived from an olefin having 3 or 4 carbon atoms or an 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 propylene or isobutylene is preferable in order to obtain a more excellent sludge generation suppressing effect.
Further, R ¹⁴ or R ¹⁵ is most preferably a tert-butyl group derived from isobutylene or a branched octyl group derived from a dimer of isobutylene in order to obtain a better antioxidant effect.

As the p, p'-dialkyldiphenylamine represented by the general formula (5), a commercially available product or a synthesized product may be used. Similar to the phenyl-α-naphthylamine represented by the general formula (4), the synthesized product is a halogenated alkyl compound having 1 to 16 carbon atoms and diphenylamine, or an olefin having 2 to 16 carbon atoms or an alkyl having 2 to 16 carbon atoms. Although it can be easily synthesized by reacting an olefin or an oligomer thereof with diphenylamine using a Friedel-Crafts catalyst, any synthesis method may be used.

The upper limit of the content of the amine-based antioxidant is preferably 2% by mass based on the total amount of the composition, more preferably 1.5% by mass, and even more preferably 1% by mass. If the content exceeds 2% by mass, sludge is generated, which is not preferable. On the other hand, the lower limit of the content of the amine antioxidant is preferably 0.001% by mass, more preferably 0.05% by mass, and still more preferably 0.1% by mass based on the total amount of the composition. When the content of the antioxidant is less than 0.001% by mass, the antioxidant effect is insufficient, which is not preferable.

As the phenolic antioxidant, any alkylphenolic compound used as an antioxidant for lubricating oils can be used, and is not particularly limited. For example, the following general formula (6) or general formula One or more alkylphenol compounds selected from the compounds represented by (7) are preferred.

In the above formula (6), R ¹⁶ represents an alkyl group having 1 to 4 carbon atoms, R ¹⁷ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ¹⁸ represents a hydrogen atom, and has 1 to 4 carbon atoms. An alkyl group, a group represented by the following general formula (i) or a group represented by the following general formula (ii) is shown.

In the above formula (i), R ¹⁹ represents an alkylene group having 1 to 6 carbon atoms, and R ²⁰ represents an alkyl group or alkenyl group having 1 to 24 carbon atoms.
In the above formula (ii), R ²¹ represents an alkylene group having 1 to 6 carbon atoms, R ²² represents an alkyl group having 1 to 4 carbon atoms, and R ²³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N represents an integer of 0 or 1.

In the above formula (7), R ²⁴ and R ²⁸ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ²⁵ and R ²⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ²⁶ and R ²⁷ each independently represents an alkylene group having 1 to 6 carbon atoms, and Y represents an alkylene group having 1 to 18 carbon atoms or a group represented by the following general formula (iii): Show.
^{^{-R 30 -S-R 31 - (}} iii)
In the above formula (iii), R ³⁰ and R ³¹ each independently represents an alkylene group having 1 to 6 carbon atoms.

In the general formula (6), R ¹⁶ represents an alkyl group having 1 to 4 carbon atoms. Of these, a tert-butyl group is preferred because it is more excellent in sludge resistance. R ¹⁷ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Among these, a hydrogen atom, a methyl group, or a tert-butyl group is preferable because it is more excellent in sludge resistance. R ¹⁸ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a group represented by the above formula (i), or a group represented by the above formula (ii). The alkyl group having 1 to 4 carbon atoms represented by R ¹⁸ is preferably a methyl group or an ethyl group from the viewpoint of superior sludge resistance.

The compound represented by the general formula (6) includes various compounds as described above. Preferred examples of these compounds include compounds in which R ¹⁸ is an alkyl group having 1 to 4 carbon atoms. 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-ethylphenol, etc .; as a compound when R ¹⁸ is a group represented by formula (i) N-hexyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) acetate, isohexyl (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, (3,5-di-tert -Butyl-4-hydroxyphenyl) acetic acid n-heptyl, (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid 2-ethylhexyl, (3,5-di-tert) Butyl-4-hydroxyphenyl) isododecyl propionic acid; a compound where R ¹⁸ 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, and the like; and mixtures thereof.

In the general formula (7), Y represents an alkylene group having 1 to 18 carbon atoms or a group represented by the above formula (iii). The alkylene group having 1 to 18 carbon atoms represented by Y may be linear or branched. An alkylene group having 1 to 6 carbon atoms is more preferable from the viewpoint of easy availability of raw materials, and includes an ethylene group (dimethylene group), a trimethylene group, a linear butylene group (tetramethylene group), a linear pentylene group (pentamethylene group), A straight-chain alkylene group having 2 to 6 carbon atoms such as a straight-chain hexylene group (hexamethylene group) is particularly preferred.

The upper limit of the content of the phenolic antioxidant is preferably 5% by mass, more preferably 2% by mass, and even more preferably 1.5% by mass based on the total amount of the composition. When the content exceeds 5% by mass, sludge is generated, which is not preferable. On the other hand, the lower limit of the content of the phenolic antioxidant is preferably 0.01% by mass, more preferably 0.05% by mass, and still more preferably 0.1% by mass based on the total amount of the composition. When the content of the antioxidant is less than 0.01% by mass, the antioxidant effect is insufficient, which is not preferable.

In the present invention, as described above, at least one base oil selected from the group consisting of hydrocarbon oils, synthetic esters and fats and oils, (B) component, (C) component, and further an amine-based antioxidant and / or By adding a phenolic antioxidant, a flame-retardant hydraulic fluid with excellent antioxidant performance and wear resistance can be obtained. In order to further improve the performance, other antioxidants are added as necessary. Agent, rust inhibitor, metal deactivator, antiwear agent, viscosity index improver, pour point depressant, antifoaming agent, anti-emulsifier, stick-slip inhibitor, oily agent, etc. Or in combination of several kinds.

Specific examples of rust inhibitors include amino acid derivatives, partial esters of polyhydric alcohols; esters such as lanolin fatty acid esters, alkyl succinic acid esters, and alkenyl succinic acid esters; sarcosine; polyhydric alcohol moieties such as sorbitan fatty acid esters. Esters; 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; amines; phosphoric acid; It can be illustrated. Of these, amino acid derivatives are preferred because of their high rust prevention effect.

As said amino acid derivative, the compound shown by following General formula (8) is mentioned.

In the formula (8), A is a group represented by the formula (9) or the formula (10), and B is an alkyl group having 1 to 12 carbon atoms or the residue of the monovalent carboxylic acid ester represented by the formula (11). R ³² is an alkyl group having 4 to 12 carbon atoms, and R ³³ is an alkyl group having 1 to 10 carbon atoms.
R ³⁵ O—CO—R ³⁴ — (9)
R ³⁷ O—CO—R ³⁶ —CO— (10)
-C-CO-O-R ³⁸ (11)
(In the formulas (9) to (11), R ³⁴ is an alkylene group having 1 to 12 carbon atoms, R ³⁶ is an alkylene group having 1 to 10 carbon atoms, and R ³⁵ and R ³⁷ are each a hydrogen atom or (It is an alkyl group having 1 to 10 carbon atoms, and R ³⁸ is an alkyl group having 1 to 10 carbon atoms.)

R ³² is an alkyl group having 4 to 12 carbon atoms, preferably an alkyl group having 4 to 10 carbon atoms, and more preferably an alkyl group having 6 to 10 carbon atoms. R ³³ and R ³⁸ are each independently an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. R ³⁷ is hydrogen or an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms.

In the present invention, one or two or more compounds arbitrarily selected from these rust inhibitors can be contained in the hydraulic fluid composition in any amount, but usually the content is The total amount of the hydraulic fluid composition is preferably 0.001 to 2.0% by mass, more preferably 0.01 to 1.5% by mass, and still more preferably 0.05 to 1% by mass.

Specific examples of the metal deactivator include benzotriazole, thiadiazole, and imidazole compounds. In the present invention, one kind or two or more kinds of compounds arbitrarily selected from these metal deactivators can be contained in any amount, but the content thereof is usually hydraulic oil. The content is desirably 0.001 to 1% by mass based on the total amount of the composition.

Specific examples of the viscosity index improver include a copolymer of one or more monomers selected from various methacrylic esters or a hydride thereof, an ethylene-α-olefin copolymer (as an α-olefin). Non-dispersed viscosity index improvers such as propylene, 1-butene, 1-pentene, etc.) or hydrides thereof, polyisobutylene or hydrogenated products thereof, hydrides of styrene-diene copolymers, and polyalkylstyrenes 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 the hydraulic fluid composition. It is desirable that the content is 0.01 to 10% by mass based on the total amount of the product.

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 is usually determined by the hydraulic fluid composition. It is desirable that the content is 0.01 to 5% by mass based on the total amount of the product. *

Specific examples of the antifoaming agent include silicones such as dimethyl silicone and fluorosilicone. In the present invention, one kind or two or more kinds of compounds arbitrarily selected from these antifoaming agents can be contained in any amount, but the content thereof is usually a hydraulic fluid composition. It is desirable that the content is 0.001 to 0.05% by mass based on the total amount.
Examples of the demulsifier include polyoxyalkylene glycol, polyoxyalkylene alkyl ether, polyoxyalkylene alkylamide, polyoxyalkylene fatty acid ester and the like.
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.

Hereinafter, the contents of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these contents.

(Examples 1 to 17, Comparative Examples 1 to 3)
As shown in Tables 1 to 4, hydraulic oil compositions were prepared by blending base oil and additives. The base oils and additives used in the examples and comparative examples are as follows.

<(A) component (base oil)>
A1: Trioleic propane oleate (kinematic viscosity at 40 ° C. 47.2 mm ² / s, viscosity index 190)
A2: High oleic acid-containing rapeseed oil (kinematic viscosity at 40 ° C. 35 mm ² / s, viscosity index 190, ratio of oleic acid to all fatty acids constituting the ester, 75 mol%, unsaturated fatty acid ratio to all fatty acids constituting the ester 90 mol%)
A3: Poly α-olefin oligomer (kinematic viscosity at 40 ° C. 44.5 mm ² / s, viscosity index 145)

<(B) component (acid scavenger)>
B1: Bis (2,6-di-tert-butylphenyl) carbodiimide represented by the following formula

(R ³ and R ⁸ are hydrogen, and R ⁴ , R ⁵ , R ⁶ and R ⁷ are tert-butyl groups.)
B2: 1,2-epoxytetradecane

<Component (C) (Antiwear Agent)>
C1: triphenylthiophosphate C2: 2-ethylhexyl acid phosphate C3: tricresyl phosphate

<Antioxidant>
D1: Np-isododecylphenyl-α-naphthylamine D2: p, p′-dioctyldiphenylamine D3: Bis (3,5-di-tert-butyl-4-hydroxyphenyl) methane

<Rust preventive>
E1: Amino acid derivative compound represented by the following formula.

(Here, R ¹ represents an octyl group, R ² represents a butyl group, and R ³ represents a butylene group.)
E2: Sorbitan monooleate

<Other additives>
F1: N methylbenzotriazole F2: Polymethacrylate (molecular weight 50,000)

The prepared hydraulic fluid composition was subjected to a flash point, an RPVOT test, a four-ball test, an FZG gear test, a V104C vane pump test, a rust prevention test, and the like. The results are shown in Tables 1 to 4. In addition, each property, a test, etc. were based on the following.

[Flash point]
Conforms to JIS K 2265 "Crude oil and petroleum products-Flash point test method".

[RPVOT test]
A test vessel with a lid containing 50 g of sample oil, a copper coiled catalyst, and 10 ml of water is placed in a cylinder equipped with a pressure gauge according to the “Rotating cylinder oxidation stability method” defined in JIS K 2514. Is pressed into 620 kPa and placed in a constant temperature bath at 150 ° C. The cylinder is rotated at 100 revolutions per minute while maintaining an angle of 30 ° C., and the time from when the pressure reaches the maximum to when the pressure is reduced to 175 kPa is evaluated.

[Four ball test]
Rotation speed in accordance with Standard Test Method for Measurement of Extreme-Pressure Properties of Lubricating Fluids (Four-Ball Method) stipulated in ASTM D 2783-88 The test is performed under the conditions of 1200 rpm, load 294 N, oil temperature room temperature, test time 30 minutes, and the average value of the wear scar diameter (mm) of the three fixed balls is measured.

[FZG gear test]
Gear test as defined in ASTM D 5182. The test is started at 1500 rpm (rotation speed 1500 rpm) and the test start oil temperature is 90 ° C., the gear is loaded with the weight specified in each stage, and is operated for 15 minutes. The seizure resistance of the oil is evaluated on a stage where the gear is burned. A stage with a load with a burned out gear is rejected.

[Vane pump test (V104C test)]
A vane pump test defined in ASTM D 2882 was conducted, the weight of the vane and the ring before and after the test was measured, and the amount of wear was measured. The test time was 100 hours.

[Rust prevention test]
Rust prevention test using general steel materials for polished steel bars specified in JIS K 2510. There are two types of test methods, distilled water and artificial seawater, depending on the water used, but this time the test was conducted with more severe artificial seawater. The test time is 24 hours and the test oil temperature wave is 60 ° C.

[Acid value]
This is defined by the titration amount of potassium hydroxide required for neutralizing acidic components contained in a certain amount of sample as defined in JIS K 2501. That is, 1 (KOH / mg) indicates the amount of acidic component contained in 1 mg that can be measured with a KOH solution.

The present invention provides a flame-retardant hydraulic fluid composition that is excellent in long life, sludge suppression performance, abrasion resistance, and seizure resistance, and is particularly resistant to hydrolysis and usable for a long period of time.

Claims

(A) At least one base oil selected from hydrocarbon oils, synthetic esters and fats and oils, (B) an epoxy compound and / or a carbodiimide compound represented by the following general formula (1) in a total amount of 0. 01 to 2% by mass, and (C) at least one antiwear agent selected from sulfur-containing phosphate ester, acidic phosphate ester, acidic phosphate ester amine salt and phosphite ester, based on the total amount of the composition. A flame-retardant hydraulic fluid composition characterized by containing 001 to 5% by mass.

(In the formula (1), R 1 and R 2 represent an alkyl group having 4 to 26 carbon atoms, an (alkyl) phenyl group, an aralkyl group, or an (alkyl) cycloalkyl group, which may be the same or different. .)
The flame retardant hydraulic fluid composition according to claim 1, wherein the carbodiimide compound represented by the general formula (1) is a compound represented by the following general formula (2).

(In formula (2), R 3 to R 8 represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and may be the same or different.)
The flame-retardant hydraulic fluid composition according to claim 1 or 2, comprising 0.01 to 5% by mass of an amine-based antioxidant and / or a phenol-based antioxidant based on the total amount of the composition.