JPH06279779A - Water-containing hydraulic fluis composition - Google Patents

Abstract

PURPOSE:To provide the composition excellent in flame retardancy, stability, corrosion resistance, abrasion resistance, etc., and improved in the capability of being easily treated by coagulating sedimentation and pump performance in a waste water treatment facility by mixing a polyoxyalklene glycol diether compound (PAGDE) with a polyoxyalkylene glycol monoether compound (PAGME), an oxypropylene glycol monoether compound (OPGME), a salt of a fatty acid and water in a specified ratio. CONSTITUTION:The composition is prepared by mixing 1-30wt.% PAGDE of an average molecular weight of 500-20000 represented by formula (1) (wherein R1 and R2 are each 6--30 deg.C hydrocarbon group; P1 and P2 polyoxyalkylene residue respectively) with 1-30wt.% PAGME represented by formula (2) (wherein R3 is a 3-20C hydrocarbon group; a is 4-25; a/b>=1/2; and x is the valence of R3), 0.1-10wt.% OPGME represented by formula (3) (wherein R4 is a 3-12C hydrocarbon group; and c is 1-4), 0.5-15wt.% salt of a fatty acid, represented by formula (4) (wherein R5 is a 5-35C hydrocarbon group; and M is a cation) and 15-97.4wt.% water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-containing hydraulic fluid composition which is a kind of flame-retardant hydraulic oil. A hydraulic fluid composition.

[0002]

2. Description of the Related Art Hydraulic systems have been widely adopted in industry,
Contributes to improved productivity. These hydraulic devices are driven by hydraulic fluid, but when used near heat sources such as devices that handle high-temperature metals, devices that generate electric sparks, and heating furnaces, there is a risk of fire, and various flame retardants Sex hydraulic oil is used. Of these flame-retardant hydraulic oils, hydrous hydraulic fluids are widely used because they are inexpensive and have excellent flame retardancy. A typical example of the water-containing hydraulic fluid is a water-glycol hydraulic fluid, and its type includes a solution type and an emulsion type. The emulsion type contains mineral oil, which may cause separation or spoilage, while
The solution-type water-glycol based hydraulic fluid has excellent performances such as noncombustibility and high temperature stability without fear of separation or decomposition.

However, it is known that the conventional water-glycol hydraulic fluid has the above-mentioned excellent performance, but has a problem in wastewater treatment. That is, when the water-glycol-based hydraulic fluid leaks from the hydraulic system and mixes with the wastewater, COD components cannot be removed by a normal wastewater treatment method such as a coagulation sedimentation method or an activated sludge method, which is effective in preventing pollution. There's a problem. Glycols are particularly problematic in the composition of the water-glycol-based working fluid in the wastewater treatment of the water-containing working fluid. The glycols usually used in water-glycol hydraulic fluids are water-soluble and cannot be separated by coagulation-sedimentation treatment, and high-molecular-weight glycols are extremely difficult to decompose by activated sludge treatment. is there. Therefore, in some cases, methods such as separation by adsorption to activated carbon and membrane separation have been studied, but they have not been put into practical use due to problems of processing speed and processing cost. A flame-retardant lubricating oil comprising polyoxyalkylene glycol diether, polyoxyethylene glycol monoether, and water has been proposed as a lubricating oil having improved wastewater treatment (Japanese Patent Publication No. 61-23240). However, since this lubricating oil uses a high proportion of water-soluble polyoxyethylene glycol monoether of 10 to 45 wt%, its coagulation-sedimentation processability is poor and its wastewater processability is still sufficient. I can't.

On the other hand, the water-containing hydraulic fluid must have excellent pump performance as well as wastewater treatment performance. However, no conventional water-containing hydraulic fluid has both excellent wastewater treatment performance and excellent pump performance.

[0005]

DISCLOSURE OF THE INVENTION The present invention has excellent flame retardancy equivalent to that of a water-glycol hydraulic fluid, stability, corrosion resistance and abrasion resistance, and aggregation in a wastewater treatment facility. An object of the present invention is to provide a water-containing hydraulic fluid composition having excellent precipitation processability and also excellent pump performance.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that instead of a polyoxyethylene glycol monoether compound instead of a specific polyoxyalkylene glycol diether compound. , Focusing on compounding a specific polyoxyalkylene glycol monoether compound, and as a result of further research, by combining a specific oxypropylene glycol monoether compound and a specific fatty acid salt, various properties such as flame retardancy can be obtained. It has been found that the present invention has high performance, excellent coagulation-sedimentation processability, and excellent pump performance, and has completed the present invention.

That is, in the present invention, (A) one or more kinds of average molecular weight represented by the following general formula (1) is 500 to 20.
1 to 30% by weight of polyoxyalkylene glycol diether compound, 1 to 30% by weight of (B), 1 to 30% by weight of polyoxyalkylene glycol monoether compound represented by the following general formula (2), and 1 or more of (C) 0.1 to 10% by weight of an oxypropylene glycol monoether compound represented by the following general formula (3), and (D) one or more kinds of fatty acid salts having 6 to 36 carbon atoms represented by the following general formula (4): 5 to 15% by weight, and (E) water 15 to 9
The water-containing hydraulic fluid composition is characterized by containing 7.4% by weight. General formula (1):

[0008]

Embedded image R ₁ —P ₁ —CH ₂ —P ₂ —R ₂

(In the formula, R ₁ and R ₂ represent a monovalent hydrocarbon group having 6 to 30 carbon atoms, P ₁ and P ₂ represent a polyoxyalkylene group consisting of an oxyethylene group and an oxypropylene group,
The weight ratio of the oxyethylene group and the oxypropylene group is
The range is 1/9 to 8/2. ) General formula (2):

[0010]

Embedded image R _3- [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _x

(In the formula, R ₃ is a monovalent or polyvalent hydrocarbon group having 3 to 20 carbon atoms, a is the average number of moles of propylene oxide added and is 4 to 25, and b is the average of ethylene oxide. Represents the number of moles added, a / b ≧ 1/2,
x represents an integer corresponding to the valence of R ₃ . ) General formula (3):

[0012]

Embedded image R ₄ —O— (C ₃ H ₆ O) _c —H

(Wherein R ₄ represents a monovalent hydrocarbon group having 3 to 12 carbon atoms, c represents the average number of moles of propylene oxide added, and represents the number of 1 to 3). ):

[0014]

[Chemical 8] R ₅ COOM

(In the formula, R ₅ represents a hydrocarbon group having 5 to 35 carbon atoms, and M represents a salt-forming cation.) The present invention will be described in detail below.

The water-containing hydraulic fluid composition of the present invention comprises, as its component (A), a polyoxyalkylene glycol diether compound represented by the general formula (1) and having an average molecular weight of 500 to 20,000 (hereinafter referred to as compound A). Sometimes). In the general formula (1) representing the compound A, R ₁ and R ₂ are monovalent hydrocarbon groups, and an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group are used. Although included, aliphatic hydrocarbon groups are preferred. The aliphatic hydrocarbon group can be linear or branched, and saturated or unsaturated. The carbon number of this monovalent hydrocarbon group is
It is 6 to 30, preferably 6 to 24. If the hydrocarbon groups R ₁ and R ₂ have less than 6 carbon atoms, the compound A
Becomes more soluble in water and adversely affects the coagulation-sedimentation processability of the working fluid, while when the carbon number exceeds 30, it adversely affects the stability of the working fluid. R ₁ and R ₂ may be the same or different. Specific examples of R ₁ and R ₂ include, for example, hexyl group, hexenyl group, octyl group, nonyl group, decyl group, dodecyl group, hexadecyl group, octadecyl group, oleyl group, benzyl group, phenyl group, tolyl group, hexyl group. Examples thereof include a phenyl group, a xylyl group, a cyclohexyl group and an octylcyclohexyl group.

P ₁ and P ₂ in the general formula (1)
Represents a polyoxyalkylene group composed of a copolymer of an oxyethylene group and an oxypropylene group, and the weight ratio of the oxyethylene group and the oxypropylene group is 1/9 to
It is in the range of 8/2, preferably in the range of 2/8 to 6/4. If the weight ratio is less than 1/9, the stability of the working fluid is adversely affected, whereas if it exceeds 8/2, the water solubility of the compound A is increased, which adversely affects the coagulation-sedimentation processability of the working fluid. Further, the oxyalkylene groups P ₁ and P ₂
In the above, the oxyethylene group unit and the oxypropylene group unit may form a random structure or a block structure, but a block structure is preferable. The molecular weight of compound A is in the range of 500 to 20,000, preferably 500 to 10,000. When the molecular weight is less than 500, the viscosity of the hydraulic fluid becomes too low, while when the molecular weight exceeds 20,000, the viscosity becomes too high. In addition, the compound A may be used individually by 1 type, and may be used in combination of 2 or more type.

The polyoxyalkylene glycol diether compound represented by the general formula (1) is produced by utilizing the method described in, for example, JP-A-48-22198 and JP-B-49-15185. be able to. That is, propylene oxide is addition-polymerized to alcohol or phenol of R ₁ OH, and then ethylene oxide is addition-polymerized to prepare oxyalkylene glycol monoether, to which sodium alkoxide is added and heated at 80 to 150 ° C. in an inert gas. It can be adjusted by a method of mixing and gradually adding methylene dihalide to the obtained product to cause reaction. Further, propylene oxide is addition-polymerized to alcohol or phenol of R ₁ OH, then ethylene oxide is addition-polymerized, and then propylene oxide is addition-polymerized to form a polyoxyalkylene glycol monoether.
It can also be adjusted by a method of etherifying the H group via a methylene group.

In the hydrous hydraulic fluid composition of the present invention,
As the component (B), a polyoxyalkylene glycol monoether compound represented by the general formula (2) (hereinafter sometimes referred to as compound B) is used. In the general formula (2), R ₃ represents a monovalent or polyvalent hydrocarbon group, and includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Group-based hydrocarbon groups are preferred. The monovalent or polyvalent hydrocarbon group has 3 to 20 carbon atoms, preferably 4 to 15 carbon atoms. When the number of carbon atoms of the monovalent or polyvalent hydrocarbon group is less than 3, the compound B becomes water-soluble and adversely affects the coagulation-sedimentation processability, while when it exceeds 20, the hydrophobicity of the compound B becomes too large. Without forming a solubilizing system, it becomes impossible to obtain a hydraulic fluid having the intended performance of the present invention. Also,
The valence of the monovalent or polyvalent hydrocarbon group may be appropriately selected, but is preferably monovalent or divalent.

The mole ratio a / b of the addition mole number a of propylene oxide and the addition mole number b of ethylene oxide is 1/2 or more, but when R ₁ has 3 to 6 carbon atoms, a / b is preferably. 18/3 to 50, particularly preferably 18 /
2 to 75/2 and the carbon number of R ₁ is 7 to 10,
a / b is preferably 7/3 to 50, particularly preferably 8/2 to 65/2, and the carbon number of R ₁ is 10 to 20.
In the case of, a / b is preferably 6/4 to 50, particularly preferably 5/5 to 65/2. When it is less than these ranges, the hydrophilicity of the compound tends to be strong, and when it exceeds the range, the stability of the system tends to be deteriorated. In addition, the propylene oxide unit and the ethylene oxide unit may form a random structure or a block structure, but the block structures represented by the following general formulas (5) and (6) are Those that form a block structure are preferable, and those that form a block structure represented by the general formula (5) are particularly preferable. General formula (5):

[0021]

Embedded image R ₃ — [O— (C ₃ H ₆ O) _a — (C ₂ H ₄ O) _b —H] _x General formula (6):

[0022]

Embedded image R ₃ — [O— (C ₂ H ₄ O) _b — (C ₃ H ₆ O) _a —H] _x

The polyoxyalkylene glycol monoether compound represented by the general formula (2) has 3 to 10 carbon atoms.
It can be obtained by adding propylene oxide and ethylene oxide to 20 monohydric or polyhydric alcohols. Specific examples of monohydric or polyhydric alcohols include, for example, propanol, butanol, propylene glycol, butanediol, hexylene glycol, octylene glycol, glycerin, trimethylolpropane,
Pentaerythritol, sorbitol, glucose, di (hydroxymethyl) cyclohexane, di (hydroxymethyl) benzene and the like can be mentioned.

When the compound B used in the present invention is derived from a monohydric alcohol, the compound B is represented by the following general formula.

[0025]

Embedded image R ₃ — [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b ] -H In the above formula, R ₃ has 3 to 20 carbon atoms, preferably 4 to 15 carbon atoms.
Represents a monovalent hydrocarbon group. As the hydrocarbon group R ₃ , a linear or branched alkyl group or alkenyl group is preferable. a represents the average number of moles of propylene oxide polymerized and is in the range of 4 to 25, preferably 4 to 20; b represents the number of average polymerized moles of ethylene oxide and is in the range of 1 to 10; It is preferably in the range of 1 to 5. The compound B may be used alone, or
You may use it in combination of 2 or more type.

In the hydrous hydraulic fluid composition of the present invention,
As the component (C), the oxypropylene glycol monoether compound represented by the general formula (3) (hereinafter, sometimes referred to as compound C) is used. In the general formula (3), R ₄ represents a monovalent hydrocarbon group, and includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, and preferably a phenyl group. Is to have. The monovalent hydrocarbon group has 3 to 1 carbon atoms.
It is in the range of 2, and preferably in the range of 4-9. The average addition mole number c of propylene oxide in the general formula (3) is 1 to 3, and preferably 1 to 2. This compound C acts as a solubilizing agent for the compounds A and B, and when R ₄ has less than 3 carbon atoms, a large amount of the compound C is required for solubilizing the compounds A and B. It becomes necessary to adversely affect the coagulation-sedimentation processability. On the other hand, when the carbon number exceeds 12, the compound C itself cannot be solubilized, so that the working fluid composition having the intended performance of the present invention cannot be obtained.

The compound C can be obtained by adding propylene oxide to an alcohol or phenol having 3 to 12 carbon atoms. Specific examples of the alcohol include, for example, propanol, butanol, pentanol, hexanol, heptanol, octanol, cyclohexyl alcohol, benzyl alcohol, methylbenzyl alcohol, ethylbenzyl alcohol, propylbenzyl alcohol and the like, but preferably benzyl alcohol or The alkyl derivative is mentioned. Specific examples of phenol include phenol, methylphenol, ethylphenol, propylphenol,
Examples thereof include butylphenol, pentylphenol and cyclohexylphenol, with preference given to phenol, methylphenol and ethylphenol. In addition, the compound C may be used individually by 1 type, and may be used in combination of 2 or more type.

In the hydrous hydraulic fluid composition of the present invention,
As the component (D), a fatty acid salt represented by the general formula (4) (hereinafter sometimes referred to as compound D) is used.
R ₅ in the general formula (4) is a hydrocarbon group,
It is preferably an aliphatic hydrocarbon group and includes a linear or branched saturated or unsaturated hydrocarbon group. The carbon number of this hydrocarbon group is in the range of 6 to 36, preferably 1
It is in the range of 0 to 20. If the number of carbon atoms in this hydrocarbon group is less than 6, the solubilizing ability will be reduced and the composition will be unstable, and if it exceeds 36, the viscosity will increase and it will be difficult to use it as a hydraulic fluid. Further, M in the general formula (4) represents a salt-forming cation, and examples thereof include an alkali metal, ammonium and amine. Specific examples of M include sodium, potassium, lithium, ammonium, ethanolamine, diethanolamine, triethanolamine, and the like, and alkali metals such as sodium and potassium are preferable. Specific examples of this fatty acid salt include, for example, capric acid, lauric acid,
Examples thereof include salts of myristic acid, palmitic acid, stearic acid, oleic acid, aromatic fatty acid, dimer acid and the like.
In addition, the compound D may be used individually by 1 type, and may be used in combination of 2 or more type.

In the hydrous hydraulic fluid composition of the present invention,
Water is used as the component (E). Purified water is preferred as the water in this case.

The compounding ratio of each component in the hydrous hydraulic fluid composition of the present invention is as follows: Compound A is in the range of 1 to 30% by weight, preferably 5 to 25% by weight, and Compound B is in the range. It is in the range of 1 to 30% by weight, preferably 10
To 20% by weight, compound C in the range 0.1 to 10% by weight, preferably 0.1 to 5% by weight, compound D in the range 0.5 to 15% by weight. And
It is preferably in the range of 2 to 10% by weight. The water content of the water-containing hydraulic fluid composition is 15 to 97.4% by weight, and preferably 40 to 82.5% by weight.
If the amount of the compound A is less than 1% by weight, the viscosity will be low, and if it exceeds 30% by weight, the oil will have poor stability or will solidify. If the content of compound B is less than 1% by weight, the viscosity will decrease,
If it exceeds 30% by weight, the composition becomes unstable. Compound C
However, if it is less than 0.1% by weight, the oil becomes unstable and 10
Oil becomes unstable when it exceeds the weight percentage. Compound D is 0.
If it is less than 5% by weight, the composition becomes unstable, and if it exceeds 15% by weight, the viscosity increases too much.

Further, the hydrous hydraulic fluid composition of the present invention may contain a polyoxyalkylene glycol compound represented by the following general formula (7) (hereinafter sometimes referred to as compound F). . General formula (7):

[0032]

HO (AO) H (In the formula, AO represents a polyoxyalkylene group consisting of an oxyethylene group and an oxypropylene group, and the weight ratio of the oxyethylene group to the polyoxyalkylene group is 5
It is 5% or less. )

In the general formula (7) representing the compound F, AO is a polyoxyalkylene group composed of a copolymer of an oxyethylene group (C ₂ H ₄ O) and an oxypropylene group (C ₃ H ₆ O). The weight ratio of the oxyethylene group to the polyoxyalkylene group is 55% or less, and it is particularly preferable to define it in the range of 30 to 55%. In this polyoxyalkylene group (AO), the oxyethylene group unit and the oxypropylene group unit may form a random structure or a block structure, but a block structure is preferable. Examples of such a block _{structure, (C 3 H 6 O)} m -
(C ₂ H ₄ O) _1- (C ₃ H ₆ O) _n (wherein, m and n are the number of moles of oxypropylene group, l is the number of moles of oxyethylene group), (C ₂ H _{4 O) q - (C 3 H} 6 O) p - (C 2 H 4
O) _r (wherein q and r are the number of moles of oxyethylene group, p
Indicates the number of moles of oxypropylene group. ) And the like.

The average molecular weight of the polyoxyalkylene glycol compound represented by the general formula (7) is about 1000.
However, it is preferable to specify the range of about 3000 to 10000. When the weight ratio of the oxyethylene group to the polyoxyalkylene group in the general formula (7) exceeds 55%, the water solubility of the compound F becomes large, which adversely affects the coagulation-sedimentation processability of the water-containing hydraulic fluid composition.
Further, when the molecular weight of the compound F is less than about 1000, the viscosity of the water-containing hydraulic fluid composition becomes too low, while when the molecular weight exceeds about 20,000, the viscosity of the water-containing hydraulic fluid composition becomes too high. The compounding amount of the compound F may be appropriately selected and determined, but is usually 0.1 to 3 in the water-containing hydraulic fluid composition.
It is in the range of wt%, preferably in the range of 0.1 to 2 wt%. The viscosity of the water-containing hydraulic fluid composition of the present invention can be appropriately adjusted according to the viscosity characteristics of the hydraulic fluid required in the hydraulic system used.

The water-containing hydraulic fluid composition of the present invention contains, in addition to the above-mentioned components, other components as required, such as sulfur compounds and phosphorus compounds as extreme pressure agents, and alkali metals and amines as pH adjusters. Add appropriate amounts of auxiliary components such as hydroxides, metal salts and amine salts of nitrogen-containing compounds such as mercaptobenzothiazole and triazole as corrosion inhibitors, and metal salts of aminocarboxylic acids such as ethylenediaminetetraacetic acid as sequestering agents. You can The hydrous hydraulic fluid composition of the present invention can be prepared by appropriately mixing and mixing the above-mentioned components in predetermined amounts.

The hydraulic system which can use the water-containing hydraulic fluid composition of the present invention is not particularly limited,
Machine tools, die casting machines, transfer machines,
Press machines, forging machines, cargo handling machines, civil construction machines,
There are various hydraulic devices such as plant control device,
In particular, it is effective in hydraulic equipment such as equipment that handles high-temperature metals that are associated with fire hazard, equipment that produces electric sparks, heating furnaces, and steel equipment. Further, the hydraulic pump used in the hydraulic device is not particularly limited and can be used for various hydraulic pumps.

[0037]

EXAMPLES Next, the present invention will be described in more detail by way of examples. The present invention is not limited to these examples. Examples 1 to 3 A water-containing hydraulic fluid composition having the composition shown in Table 1 was prepared and its performance was evaluated. The results are shown in Table 3. The polyoxyalkylene glycol diether compound and the polyoxyalkylene glycol monoether compound used in the examples had a block structure, and purified water was used as water.

[0038]

[Table 1] (Note) In Table 1, Ph in the chemical formula of the component C of Example 1
Represents a phenyl group.

Comparative Examples 1 to 3 The performances of three commercially available water / glycol type working fluids (I), (II) and (III) having a water content of 70 wt% or less were evaluated. The results are shown in Table 3. These commercially available water / glycol-based hydraulic fluids (I), (II) and (III) are 35 to 45% by weight of water, 40 to 50% by weight of a solvent (glycol), and 10 to 15% by weight of a thickener. %,
It is a hydraulic fluid having a composition of several% to 15% by weight of other additives.

Comparative Example 4 The performance of a commercially available thickened high water content working fluid (IV) having a water content of 80 wt% or more was evaluated. The results are shown in Table 3. In addition, a commercially available thickened highly water-containing hydraulic fluid (IV)
Is a hydraulic fluid having a composition of 75 to 98% by weight of water, 1 to 15% by weight of a thickener and 1 to 10% by weight of other additives.

Comparative Example 5 A water-containing hydraulic fluid composition having the composition shown in Table 2 was prepared and its performance was evaluated. The results are shown in Table 3.

[0042]

[Table 2]

The properties of the water-containing hydraulic fluid composition shown below were evaluated by the following test methods. (1) Coagulation-sedimentation treatment test 1% by weight of aluminum sulfate (Al ₂ (SO ₄ ) ₃ · 14-18H ₂ O) was added to 100 parts by weight of a 1% aqueous solution of a working fluid, and then the pH was adjusted to 6 with an aqueous NaOH solution. Adjust to 5. After rapid stirring for 10 minutes and slow stirring for 15 minutes, the mixture was allowed to stand for 1 hour and filtered with a filter paper (5C).
The value was measured. The treatment rate was calculated by the following formula, and the value was used to evaluate the coagulation-sedimentation processability of the working fluid. It is indicated that the higher the treatment rate is, the better the coagulation-sedimentation processability is.

[0044]

[Equation 1]

[0045]

[Table 3]

For each hydraulic fluid of Example 1 and Comparative Example 1,
A shell four-ball test (ASTM D-2783 compliant) and a metal corrosion test (JIS K 2234 compliant) were performed. The results are shown in Table 4. (2) Shell four-ball test (according to ASTM D-2783) It was measured under the following conditions. Conditions: 1200 rpm, 15 kg, 30 min

[0047]

[Table 4] (3) Metal corrosion test (according to JIS K 2234) Measurement was performed under the following conditions. Conditions: 70 ° C x 168 hr

[0048]

[Table 5] As is clear from the results of Tables 3 to 5, each of the water-containing hydraulic fluid compositions of the present invention has sufficient performance as a hydraulic fluid and is also excellent in coagulation-sedimentation processability. I understand.

(4) Pump Performance Test Next, in Example 1, a hydraulic pump (P, manufactured by Yuken Kogyo Co., Ltd.) was used.
V2R2-26) was used to perform a pump performance test under the following conditions. Set pressure: 140 kgf / cm ² Number of revolutions: 1200 rpm Test time: 100 hr As a result of the pump performance test, the amount of wear of the vane and the cam ring was 73 mg.

[0050]

EFFECTS OF THE INVENTION The hydrous hydraulic fluid composition of the present invention has excellent flame retardancy equivalent to that of a water-glycol hydraulic fluid, and requires stability, corrosion resistance, abrasion resistance and other hydraulic fluids. In addition to having excellent properties, the coagulation-sedimentation processability in a wastewater treatment facility is excellent, and the pump performance is also excellent. Therefore, even if the hydrous working fluid of the present invention is mixed with waste water, the base compound is not dissolved in a large amount of waste water and is separated from the water, and is not substantially dissolved in the waste water. There is no particular hindrance to the processing.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C10N 10:02 20:04 30:00 Z 8217-4H 30:02 40:08 (72) Inventor Daisuke Yamada 1134-2 Gongendo, Satte City, Saitama Prefecture Cosmo Research Institute Co., Ltd. (72) Inventor Mayumi Yamamoto 1134-2, Gongendo Satte City, Saitama Co., Ltd. Research & Development Center

Claims (1)

[Claims] (A) 1 to 30% by weight of (A) a polyoxyalkylene glycol diether compound represented by the following general formula (1) and having an average molecular weight of 500 to 20,000:
(B) One or more polyoxyalkylene glycol monoether compounds 1 to 30 represented by the following general formula (2)
%, (C) one or more oxypropylene glycol monoether compounds represented by the following general formula (3).
1 to 10% by weight, (D) 0.5 to 15% by weight of one or more kinds of fatty acid salts having 6 to 36 carbon atoms represented by the following general formula (4), and (E) 15 to 97.4% by weight of water. A water-containing hydraulic fluid composition comprising: General formula (1): embedded image R ₁ —P ₁ —CH ₂ —P ₂ —R ₂ (wherein R ₁ and R ₂ are monovalent hydrocarbon groups having 6 to 30 carbon atoms, P ₁ , P ₂ represents a polyoxyalkylene group composed of an oxyethylene group and an oxypropylene group, and the weight ratio of the oxyethylene group and the oxypropylene group is 1/9 to 8
The range is / 2. ) General formula (2): embedded image R _3- [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _x (wherein R ₃ is a monovalent group having 3 to 20 carbon atoms) Or a polyvalent hydrocarbon group, a is an average addition mole number of propylene oxide of 4 to 25, b is an average addition mole number of ethylene oxide, a / b ≧ 1/2, and x is An integer corresponding to the valence of R ₃ is shown.) General formula (3): embedded image R ₄ —O— (C ₃ H ₆ O) _c —H (wherein R ₄ has 3 to 12 carbon atoms). Represents a monovalent hydrocarbon group, and c represents the average number of added moles of propylene oxide and represents a number of 1 to 3.) General formula (4): embedded image R ₅ COOM (wherein R ₅ Represents a hydrocarbon group having 5 to 35 carbon atoms, and M represents a salt-forming cation.)