JPH06279780A - Water-containing hydraulic fluid - Google Patents

Abstract

PURPOSE:To provide the fluid having flame retardancy, stability, corrosion resistance and abrasion resistance and improved in the capability of being easily treated by coagulation sedimentation and pumpability in a waste water disposal facility by mixing a polyoxyalkylene glycol monoether compound (PAGME) with a salt of a fatty acid, water and a polyoxyalkylene glycol compound (PAG) in a specified ratio. CONSTITUTION:The fluid is prepared by mixing 5-40wt.% PAGME represented by formula (1) (wherein R1 is a 3-20C hydrocarbon group; a is the average number of moles of propylene oxide added and is 4-25; b is the average number of moles of ethylene oxide added, a/b >=1/2; and x is the valence of R1), 5-20wt.% salt of a fatty acid, represented by formula (2) (wherein R2 is a 5-35C hydrocarbon group; and M is a cation), 37-89.9wt.% water and 0.1-3wt.% PAG of an average molecular weight of 1000-20000 represented by formula (3) (wherein AO is a polyoxyalkylene group in which the weight ratio of the oxyethylene groups to the polyoxyalkylene groups is 55% or below).

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 fluid, and more specifically to a water-containing hydraulic fluid composition having excellent pump performance and wastewater treatment performance, as well as various performances such as stability. 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 oil, 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-retardant operations will occur. 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 may cause separation or spoilage, while the solution type water-glycol hydraulic fluid has no concerns about separation or spoilage and has excellent performance such as non-combustibility and high temperature stability. There is.

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 is excellent in a wastewater treatment facility. It is another object of the present invention to provide a water-containing hydraulic fluid composition that has the coagulation-sedimentation processability and 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 a specific polyoxyalkylene glycol monoether compound is used instead of the polyoxyethylene glycol monoether compound. As a result of further intensive research focusing on the use, stability was improved by combining a specific polyoxyalkylene glycol monoether compound and a specific fatty acid salt,
It has various properties such as corrosion resistance and flame retardancy, and even if mixed in wastewater, the base compound does not dissolve in a large amount of wastewater but separates from water, and it is practically insoluble in wastewater. It was found that the coagulation-sedimentation processability and the excellent pump performance were exhibited, and the present invention was completed.

That is, the present invention comprises (A) 5 to 40 wt% of a polyoxyalkylene glycol monoether compound represented by the following general formula (1), and (B) a carbon number of 6 to 36 represented by the following general formula (2). 5 to 20 fatty acid salts
The present invention provides a water-containing hydraulic fluid characterized by containing wt% and (C) 40 to 90% by weight of water.
General formula (1):

[0008]

Embedded image R _1- [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _x (wherein R ₁ is a monovalent or polyvalent hydrocarbon group having 3 to 20 carbon atoms). , 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 corresponds to the valence of R _1. The general formula (2):

[0009]

Embedded image R ₂ COOM (wherein, R ₂ is a hydrocarbon group having 5-35 carbon atoms, M represents a salt-forming cation.)

The present invention also provides (A) the following general formula (1)
5 to 40% by weight of a polyoxyalkylene glycol monoether compound represented by: (B) 5 to 20% by weight of a fatty acid salt of 6 to 36 carbon atoms represented by the following general formula (2):
(C) 37 to 89.9% by weight of water, and (D) 0.1 to 3% by weight of a polyoxyalkylene glycol compound represented by the following general formula (3) and having an average molecular weight of 1000 to 20,000. The present invention provides a hydrous hydraulic fluid characterized by the above. General formula (1):

[0011]

Embedded image R _1- [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _x (wherein R ₁ is a monovalent or polyvalent hydrocarbon group having 3 to 20 carbon atoms). , 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 corresponds to the valence of R _1. The general formula (2):

[0012]

Embedded image R ₂ COOM (wherein R ₂ represents a hydrocarbon group having 5 to 35 carbon atoms, and M represents a salt-forming cation) General formula (3):

[0013]

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. ) Hereinafter, the present invention will be described in detail.

In the hydrous hydraulic fluid of the present invention, the polyoxyalkylene glycol monoether compound represented by the general formula (1) (hereinafter sometimes referred to as compound A) is used as the component (A). R ₁ in the general formula (1) represents a monovalent or polyvalent hydrocarbon group, and includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, Hydrocarbon groups are preferred. The monovalent or polyvalent hydrocarbon group has 3 carbon atoms.
Is in the range of 20 to 20, preferably in the range of 4 to 15. When the number of carbon atoms of the monovalent or polyvalent hydrocarbon group is less than 3, the compound A becomes water-soluble, which adversely affects the coagulation-sedimentation processability, while when it exceeds 20, the hydrophobicity of the compound A becomes too large. Without forming a solubilizing system, it becomes impossible to obtain a hydraulic fluid having the intended performance of the present invention. The valency of the monovalent or polyvalent hydrocarbon group may be appropriately selected, but monovalent or divalent is preferable.

The molar 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.

The propylene oxide unit and the ethylene oxide unit may form a random structure or a block structure, which are represented by the following general formulas (4) and (5). Those that form a block structure are preferable, and those that form a block structure represented by the general formula (4) are particularly preferable. General formula (4):

[0017]

Embedded image R ₁ — [O— (C ₃ H ₆ O) _a — (C ₂ H ₄ O) _b —H] _x General formula (5):

[0018]

Embedded image R _1- [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 (1) has 3 to 10 carbon atoms.
It can be obtained by adding propylene oxide and propylene 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 A used in the present invention is derived from a monohydric alcohol, the compound A is represented by the following general formula.

[0021]

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

In the hydrous hydraulic fluid of the present invention, (B)
As the component, the fatty acid salt of the general formula (2) (hereinafter sometimes referred to as compound B) is used. The general formula (2)
R _{2 in} is a hydrocarbon group, preferably an aliphatic hydrocarbon group. The aliphatic hydrocarbon group includes a linear or branched saturated or unsaturated hydrocarbon group.
The hydrocarbon group has 6 to 36 carbon atoms, preferably 10 to 20 carbon atoms. 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 (2) represents a salt-forming cation, and examples thereof include alkali metals, ammonium and amines. As a specific example of M,
For example, sodium, potassium, lithium, ammonium, ethanolamine, diethanolamine, triethanolamine and the like, preferably sodium,
It is an alkali metal such as potassium. Specific examples of this fatty acid salt include, for example, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid,
Examples thereof include salts of aromatic fatty acids and dimer acids. In addition, the compound B may be used individually by 1 type, and may be used in combination of 2 or more type.

In the hydraulic fluid of the present invention, water is used as the component (C). Purified water is preferred as the water in this case. Further, in the hydraulic fluid of the present invention, a polyoxyalkylene glycol compound represented by the general formula (3) (hereinafter sometimes referred to as compound D) is used as the component (D), if necessary. . In the general formula (3) representing the compound D, AO represents 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%.

The polyoxyalkylene group (A
In O), the oxyethylene group unit and the oxypropylene group unit may form a random structure or a block structure, but a block structure is preferable. An example of such a block structure is (C ₃ H _{6
O) m - (C 2 H} 4 O) l - (C 3 H 6 O) n ( wherein, m, n
Indicates the number of moles of oxypropylene groups, and l indicates the number of moles of oxyethylene groups. _{), (C 2 H 4 O} ) q - (C 3 H 6 O) p -
(C ₂ H ₄ O) _r (wherein q and r represent the number of moles of oxyethylene group, p represents the number of moles of oxypropylene group) and the like. The polyoxyalkylene glycol compound represented by the general formula (3) has an average molecular weight of about 100.
0 to 20,000, but especially about 3,000 to 10,
It is preferable to define it in the range of 000. When the weight ratio of the oxyethylene group to the polyoxyalkylene group in the general formula (3) exceeds 55%, the water solubility of the compound D becomes large, which adversely affects the coagulation-sedimentation processability of the working fluid. Further, if the molecular weight of compound D is less than about 1000, the viscosity of the working fluid becomes too low, while if the molecular weight exceeds about 20,000, the viscosity of the working fluid becomes too high. Compound D may be used alone or in combination of two or more.

The mixing ratio of each component in the water-containing hydraulic fluid of the present invention is shown below. When the water-containing hydraulic fluid is composed of compound A, compound B and water, compound A is 5-40% by weight, preferably 10-30. %, The compound B is 5 to 20% by weight, preferably 6 to 15% by weight. The amount of water is 40 to 9
It is 0% by weight, preferably 55 to 86% by weight. When the water-containing hydraulic fluid is composed of compound A, compound B, water and compound D, compound A is 5 to 40% by weight, preferably 10 to 30%.
% By weight, compound B 5-20% by weight, preferably 6-1
5% by weight, water is 37 to 89.9% by weight, preferably 53
˜84.9% by weight, Compound D is 0.1 to 3% by weight, preferably 0.1 to 2% by weight. If the content of the compound A is less than 5% by weight, the viscosity is lowered, and if it exceeds 40% by weight, the composition becomes unstable. If the content of the compound B is less than 5% by weight, the composition becomes unstable, and if it exceeds 20% by weight, the viscosity is excessively increased. Further, when the compound D is less than 0.1% by weight, the viscosity is lowered, and when it exceeds 3% by weight, the viscosity is increased.

The viscosity of the hydrous 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 of the present invention,
In addition to the above components, other components as necessary, for example, sulfur compounds and phosphorus compounds as extreme pressure agents, hydroxides of alkali metals and amines as pH adjusters, mercaptobenzothiazole, triazoles as corrosion inhibitors, etc. An appropriate amount of auxiliary components such as a metal salt or amine salt of a nitrogen-containing compound and a metal salt of an aminocarboxylic acid such as ethylenediaminetetraacetic acid as a sequestering agent can be added. The hydrous working fluid of the present invention can be prepared by appropriately mixing and mixing the above-mentioned components in predetermined amounts.

The hydraulic device which can use the water-containing hydraulic fluid of the present invention is not particularly limited, and it is a machine tool, die casting machine, transfer machine, press machine, forging machine, cargo handling machine, civil construction machine. Various hydraulic devices such as a plant control device are particularly effective in hydraulic devices such as a device that handles high-temperature metal that is associated with a fire hazard, a device that produces an electric spark, a heating furnace, and steel equipment. Also, the hydraulic pump used in the hydraulic device is not particularly limited, and various hydraulic pumps can be used.

[0029]

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 5 A water-containing hydraulic fluid having the component composition shown in Table 1 was prepared and its performance was evaluated. The results are shown in Table 3. The polyoxyalkylene glycol monoether compound and the polyoxyalkylene glycol compound used in Examples had a block structure in the polyoxyalkylene portion, and purified water was used as water.

[0030]

[Table 1]

Comparative Examples 1 to 3 The performances of three commercially available water / glycol hydraulic 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 has 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. The commercially available thickening type high water content working fluid (IV) is a working fluid having a composition of 75 to 98% by weight of water, 1 to 15% by weight of a thickening agent and 1 to 10% by weight of other additives. .

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

[0034]

[Table 2]

The properties of the hydraulic fluid shown below are 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.

[0036]

[Equation 2]

[0037]

[Table 3]

A shell four-ball test (according to ASTM D-2783) and a metal corrosion test (according to JIS K 2234) were conducted for each hydraulic fluid of the examples. The results are shown in Tables 4-7. (2) Shell four-ball test (according to ASTM D-2783) It was measured under the following conditions. Conditions: 1200 rpm, 15 kg, 30 min

[0039]

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

[0040]

[Table 5]

[0041]

[Table 6]

[0042]

[Table 7] As is clear from the results of Tables 3 to 7, 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, for Example 5 and Comparative Example 4, a pump performance test was conducted under the following conditions using a hydraulic pump (PV2R2-26 manufactured by Yuken Industry Co., Ltd.). Set pressure: 140 kgf / cm ² Number of revolutions: 1200 rpm Test time: 100 hr As a result of a pump performance test, the vane and cam ring wear amounts were 70.3 mg in Example 5 and 80.
It was 2 mg.

[0044]

The water-containing hydraulic fluid of the present invention has excellent flame retardancy equivalent to that of a water-glycol hydraulic fluid, and is required for a hydraulic fluid having stability, corrosion resistance and abrasion resistance. In addition to having excellent properties, it also has excellent pump performance.
In addition, it has excellent coagulability and sedimentation processability in wastewater treatment facilities. 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 30:06 30:12 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 Research and Development In the center

Claims (2)

[Claims] 1. A polyoxyalkylene glycol monoether compound 5-4 represented by the following general formula (1):
0% by weight, (B) 5 to 20% by weight of a C6 to C36 fatty acid salt represented by the following general formula (2), and (C) water 40
A water-containing hydraulic fluid containing 90 to 90% by weight. General formula (1): embedded image R _1- [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _x (wherein R ₁ is a monovalent group having 3 to 20 carbon atoms or 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 R . an integer corresponding to the valence of ₁₎ the general formula (2): ## STR2 ## in R ₂ COOM (wherein, R ₂ is a hydrocarbon group having 5-35 carbon atoms, M is a salt-forming cation Represent) 2. (A) Polyoxyalkylene glycol monoether compounds 5 to 4 represented by the following general formula (1):
0% by weight, (B) 5 to 20% by weight of a fatty acid salt having 6 to 36 carbon atoms represented by the following general formula (2), (C) water 37 to 8
9.9% by weight, and (D) a water-containing water containing 0.1 to 3% by weight of a polyoxyalkylene glycol compound represented by the following general formula (3) and having an average molecular weight of 1000 to 20000: System hydraulic fluid. General formula (1): embedded image R _1- [O (C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _x (wherein R ₁ is a monovalent group having 3 to 20 carbon atoms or 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 R . an integer corresponding to the valence of ₁₎ the general formula (2): embedded image R ₂ COOM (wherein, R ₂ is a hydrocarbon group having 5-35 carbon atoms, M is a salt-forming cation General formula (3): HO (AO) H (In the formula, AO represents a polyoxyalkylene group composed of an oxyethylene group and an oxypropylene group, and the oxyethylene group has a polyoxyalkylene group relative to the polyoxyalkylene group. Weight ratio is 5
It is 5% or less. )