JP2023063105A - Water-soluble processing oil composition and metal processing method - Google Patents

Abstract

To provide a water-soluble processing oil composition capable of maintaining a foaming suppressing effect, and a metal processing method using the water-soluble processing oil composition.SOLUTION: A water-soluble processing oil composition comprises: a base oil (A); and a silicone antifoaming agent (B) modified with a polyalkylene oxide modifying group, wherein the silicone antifoaming agent (B) has a weight average molecular weight of more than 26,000.SELECTED DRAWING: None

Description

The present invention relates to a water-soluble working oil composition and a metal working method.

When performing metal processing such as turning, planing, drilling, and milling on iron and steel or non-ferrous metal materials, it is necessary to reduce friction between the tool and the workpiece or chips, remove chips, prevent formation of built-up edge, Metalworking is performed using a working oil composition for the purpose of suppressing heat generation, cooling, or the like. In general, processing oil compositions are broadly classified into water-insoluble processing oil compositions whose main purpose is lubrication and water-soluble processing oil compositions whose main purpose is cooling.

For example, water-soluble cutting oil compositions, which are one type of water-soluble working oil composition, are classified into types A1, A2, and A3 according to JIS K2241. All of them are used after being diluted with water, and while A3 type is composed only of water-soluble components, A1 type and A2 type also contain water-insoluble components. Therefore, A1 type and A2 type are emulsions containing surfactants.
Type A1 is called emulsion, and type A2 is called soluble, and has higher workability than type A3. The reason for exhibiting this high workability is often due to the inclusion of water-insoluble components. Therefore, when A1 and A2 types are used, it is important to stably emulsify the water-insoluble components when diluting the A1 and A2 types before metalworking.

A surfactant is generally used to maintain a stable emulsified state, but the presence of the surfactant may cause the water-soluble processing oil composition to foam violently.
For example, in some processing, a water-soluble processing oil composition is supplied to the processing point at high pressure, but at such times, a large amount of foam is generated, and problems such as overflowing from the tank may occur. .
Antifoaming agents are generally used to suppress such foaming.

For example, in Patent Document 1, based on the total amount of the composition, (A) 15 to 50% by mass of a block-type polyoxyalkylene compound having a specific structure and (B) 1.0 to 15% of a fatty acid having 8 to 10 carbon atoms mass%, (C) at least one basic compound selected from alkali metal hydroxides, aliphatic amines, alicyclic amines, aromatic amines, alkanolamines, polyamines, and nitrogen-containing compounds with specific structures , the neutralization equivalent of the component (B) or more, and the total amount of the component (B) and the component (C) is contained in a range of 1.1 to 85% by mass, and further water is contained in an amount of 0 to 60% by mass. % is disclosed. It is stated that the water-soluble cutting fluid concentrate composition described in Patent Document 1 causes little foaming even when supplied at high pressure.

JP-A-08-239683

In the water-soluble processing oil composition, the antifoaming agent is stably dispersed in the oil in both the undiluted state at the time of manufacture and sale and the state diluted with water at the time of processing. (hereinafter referred to as antifoaming agent stability) is preferably maintained. Poor stability of the antifoaming agent in the undiluted water-soluble process oil composition may, for example, cause the antifoaming agent to settle in the water-soluble process oil composition. Then, when diluting the water-soluble processing oil composition, only the supernatant containing almost no antifoaming agent is collected, and foaming cannot be suppressed when the resulting diluted product is subjected to processing. There is
In addition, if the stability of the antifoaming agent in the water-soluble processing oil composition diluted with water is poor, for example, the antifoaming agent in the water-soluble processing oil composition settles in the tank, Foaming may not be suppressed when subjected to processing.
In the conventional water-soluble working oil composition such as the water-soluble cutting fluid concentrate composition of Patent Document 1 described above, the water-soluble working oil in the undiluted state and in the state diluted with water when subjected to processing There is room for improvement in the antifoam stability of the composition.

The present invention has been made in view of the above circumstances, and provides a water-soluble working oil composition capable of maintaining the effect of suppressing foaming, and a metal working method using the water-soluble working oil composition. is the subject.

As a result of extensive studies, the inventors have found that by using a base oil and a silicone-based antifoaming agent that has a specific molecular weight and is modified with a polyalkylene oxide modifying group, the undiluted state and processing can be achieved. It has been found that the dispersibility and stability of the silicone antifoaming agent in the water-soluble processing oil composition are improved in both water-diluted states when applied.
That is, with the above-described specific configuration, a water-soluble processed oil composition that has good foaming suppression properties even when the stock solution is diluted and does not deteriorate in foaming suppression properties even when the stock solution is stored for a long period of time has been found. I have perfected my invention.
Specifically, the present invention employs the following configurations.

[1] It contains a base oil (A) and a silicone antifoaming agent (B) modified with a polyalkylene oxide modifying group, and the silicone antifoaming agent (B) has a weight average molecular weight of more than 26,000. A water-soluble processing oil composition.
[2] The water-soluble processing oil composition according to [1], wherein the silicone antifoaming agent (B) has a modification rate of more than 0.12% and less than 2.38%.
[3] The water-soluble processing oil composition according to [1] or [2], wherein the polyalkylene oxide modified group in the silicone antifoaming agent (B) has a molecular weight of 5,000 or more.
[4] Any one of [1] to [3], further comprising one or more surfactants selected from the group consisting of nonionic surfactants and anionic surfactants. water-soluble processing oil composition.
[5] The water-soluble processing oil composition according to any one of [1] to [4], wherein the kinematic viscosity at 40° C. of the base oil (A) is 10 mm ² /s or more and 100 mm ² /s or less. thing.
[6] The water-soluble working oil composition according to any one of [1] to [5], which is used for cutting or grinding metal.
[7] The water-soluble working oil composition according to [6], wherein the metal includes one or more metals selected from the group consisting of aluminum, aluminum alloys, copper, copper alloys, iron, and iron alloys. .
[8] A dilution step of diluting the water-soluble working oil composition according to any one of [1] to [5] with water, and using the diluted water-soluble working oil composition to perform metal processing. A metalworking method, comprising:

ADVANTAGE OF THE INVENTION According to this invention, the water-soluble working oil composition which can maintain a foaming inhibitory effect, and the metalworking method using the said water-soluble working oil composition can be provided.

It is a schematic diagram which shows a foaming test apparatus.

As used herein, "viscosity index" means a viscosity index measured according to JIS K 2283:2000.
As used herein, "sulfur content" means a value measured according to JIS K 2541-6:2013.
As used herein, "content of saturates" means a value measured according to ASTM D 2007-93.

In the present specification, "naphthene content" and "paraffin content" are values for determining their proportions based on the molecular ion intensity obtained by mass spectrometry using FI ionization (using a glass reservoir). The measuring method is specifically shown below.

(1) An adsorption tube for elution chromatography having a diameter of 18 mm and a length of 980 mm is filled with 120 g of silica gel with a nominal diameter of 74 to 149 μm (grade 923 manufactured by Fuji Silysia Chemical Co., Ltd.) activated by drying at about 175° C. for 3 hours.
(2) Inject 75 mL of n-pentane to pre-wet the silica gel.
(3) Accurately weigh about 2 g of a sample, dilute with an equal volume of n-pentane, and inject the obtained sample solution.
(4) When the liquid surface of the sample solution reaches the upper end of the silica gel, 140 mL of n-pentane is injected to separate the saturated hydrocarbon component, and the eluate is recovered from the lower end of the adsorption tube.
(5) The eluate is subjected to a rotary evaporator to remove the solvent to obtain a saturated hydrocarbon component.
(6) Type analysis of saturated hydrocarbon components with a mass spectrometer. As an ionization method in mass spectrometry, an FI ionization method using a glass reservoir is used, and a mass spectrometer, JMS-AX505H manufactured by JEOL Ltd. is used.

Measurement conditions are shown below.
Acceleration voltage: 3.0 kV, cathode voltage: -5 to -6 kV, resolution: about 500, emitter: carbon, emitter current: 5 mA, measurement range: mass number 35 to 700, auxiliary oven temperature: 300°C, separator temperature: 300 °C, main oven temperature: 350 °C, sample injection volume: 1 µL.

After isotope correction, molecular ions obtained by mass spectrometry were divided into paraffins (C _n H _2n+2 ) and naphthenes (C _n H _2n , C _n H _2n−2 , C _n H _2n−4 . . ) are classified and organized into two types, the fraction of each ionic strength is obtained, and the content of each type with respect to the entire saturated hydrocarbon component is determined. Next, based on the content of saturated hydrocarbon components, the content of paraffins and naphthenes in the entire sample is determined.

The details of data processing by the type analysis method of FI method mass spectrometry are described in "Nisseki Review" Vol. .

As used herein, the term “aromatic content” means a value measured according to the fluorescent indicator adsorption method of JIS K 2536-1:2003 “Petroleum products—Methods for testing ingredients”.

As used herein, "kinematic viscosity at 40°C" means kinematic viscosity (mm ² /s) at 40°C measured according to JIS K 2283:2000.

As used herein, "weight-average molecular weight Mw" means a polystyrene-equivalent value determined by gel permeation chromatography (GPC) using the following measuring device and measuring conditions.
Apparatus used: Prominence series manufactured by Shimadzu Corporation Detector: RID-10A
Column: Shodex KF-405LHQ
Mobile phase: THF
Flow rate: 0.5mL/min
Concentration: 5,000mg/L
Calibrator: Polystyrene

(Water-soluble processing oil composition)
The water-soluble processing oil composition of the present embodiment comprises a base oil (A) and a silicone antifoaming agent (B) modified with a polyalkylene oxide modifying group (hereinafter also referred to as "silicone antifoaming agent (B)" ) and

<Base oil (A)>
The base oil (A) of the water-soluble processed oil composition of the present embodiment includes mineral oil and synthetic oil.

≪Mineral oil≫
As mineral oil, specifically, solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrogenation for lubricating oil fractions obtained by atmospheric distillation and vacuum distillation of crude oil Mineral oils obtained by applying one or more refining means such as refining, washing with sulfuric acid, and treatment with clay can be mentioned.

Mineral oils include Group I base oils (hereinafter sometimes referred to as "API Group I base oils") and Group II base oils (hereinafter sometimes referred to as "API Group II base oils"). , or Group III base oils (hereinafter sometimes referred to as "API Group III base oils"), or mixtures thereof.
API Group I base oils are mineral base oils with a sulfur content of greater than 0.03 wt.% and/or a saturate content of less than 90 wt.
API Group II base oils are mineral base oils having a sulfur content of 0.03 mass % or less, a saturate content of 90 mass % or more, and a viscosity index of 80 or more and less than 120.
API Group III base oils are mineral base oils having a sulfur content of 0.03 wt.% or less, a saturates content of 90 wt.% or more, and a viscosity index of 120 or more.

The base oil (A) may consist of one mineral oil, or may be a mixed base oil containing two or more mineral oils. In mixed base oils comprising two or more mineral oils, the API classifications of those mineral oils may be the same or different from each other.
The mineral oil in the base oil (A) preferably contains an API group I base oil or an API group II base oil from the viewpoint of the stability of the defoamer in the water-soluble process oil composition.

When the base oil (A) is an API Group I base oil, the paraffin content in the base oil is preferably 45% by volume or more, more preferably 55% by volume or more, from the viewpoint of working environment (low odor), More preferably, it is 65% by volume or more.
The paraffin content in the base oil is preferably 90% by volume or less, more preferably 80% by volume or less, and even more preferably 70% by volume or less, from the viewpoint of stability of the composition.
In one embodiment, the paraffin content in the base oil is preferably 45% to 90% by volume, more preferably 55% to 80% by volume, and even more preferably 65% to 70% by volume. .

When the base oil (A) is an API Group I base oil, the naphthene content in the base oil is preferably 5% by volume or more, more preferably 15% by volume or more, from the viewpoint of stability of the composition. It is preferably at least 25% by volume.
In addition, the naphthene content in the base oil is preferably 50% by volume or less, more preferably 40% by volume or less, and even more preferably 30% by volume or less, from the viewpoint of working environment (low odor).
In one embodiment, the naphthene content in the base oil is preferably 5% to 50% by volume, more preferably 15% to 40% by volume, and even more preferably 25% to 30% by volume. .

When the base oil (A) is an API Group I base oil, the aromatic content in the base oil is preferably 10% by volume or less, more preferably 8% by volume or less, and even more preferably 6% by volume or less. .

For example, when the base oil (A) is an API Group I base oil, the API Group I base oil has a paraffin content of 60% by volume or more and 70% by volume or less, and a naphthene content of , 20% by volume or more and 30% by volume or less, and the aromatic content is preferably 10% by volume or less.

When the base oil (A) is an API Group II base oil, the paraffin content in the base oil is preferably 50% by volume or more, more preferably 60% by volume or more, and even more preferably 70% by volume or more.
The paraffin content in the base oil is preferably 95% by volume or less, more preferably 90% by volume or less, and even more preferably 85% by volume or less.
In one embodiment, the paraffin content in the base oil is preferably 50% to 95% by volume, more preferably 60% to 90% by volume, and even more preferably 70% to 85% by volume. .

When the base oil (A) is an API Group II base oil, the naphthene content in the base oil is preferably 5% by volume or more, more preferably 10% by volume or more, and even more preferably 15% by volume or more.
The naphthene content in the base oil is preferably 50% by volume or less, more preferably 40% by volume or less, and even more preferably 30% by volume or less.
In one embodiment, the naphthene content in the base oil is preferably 5% to 50% by volume, more preferably 10% to 40% by volume, and even more preferably 15% to 30% by volume. .

When the base oil (A) is an API Group II base oil, the aromatic content in the base oil is preferably 5% by volume or less, more preferably 3% by volume or less, and even more preferably 1% by volume or less. and may be below the detection limit.

For example, when the base oil (A) is an API Group II base oil, the API Group II base oil has a paraffin content of 70% by volume or more and 85% by volume or less, and a naphthene content of , 15% by volume or more and 30% by volume or less, and the content of the aromatic component is preferably 1% by volume or less.

When the base oil (A) is an API Group III base oil, the paraffin content in the base oil is preferably 60% by volume or more, more preferably 65% by volume or more, and even more preferably 70% by volume or more.
The paraffin content in the base oil is preferably 95% by volume or less, more preferably 90% by volume or less, and even more preferably 85% by volume or less.
In one embodiment, the paraffin content in the base oil is preferably 60% to 95% by volume, more preferably 65% to 90% by volume, and even more preferably 70% to 85% by volume. .

When the base oil (A) is an API Group III base oil, the naphthene content in the base oil is preferably 5% by volume or more, more preferably 10% by volume or more, and even more preferably 15% by volume or more.
The naphthene content in the base oil is preferably 40% by volume or less, more preferably 35% by volume or less, and even more preferably 30% by volume or less.
In one embodiment, the naphthene content in the base oil is preferably 5% to 40% by volume, more preferably 10% to 35% by volume, and even more preferably 15% to 30% by volume. .

When the base oil (A) is an API Group III base oil, the aromatic content in the base oil is preferably 5% by volume or less, more preferably 3% by volume or less, and even more preferably 1% by volume or less. and may be below the detection limit.

For example, when the base oil (A) is an API Group III base oil, the API Group III base oil has a paraffin content of 70% by volume or more and 85% by volume or less, and a naphthene content of , 15% by volume or more and 30% by volume or less, and the content of the aromatic component is preferably 1% by volume or less.

≪Synthetic oil≫
Synthetic oils include polyolefins, alkylbenzenes, and the like.

• Polyolefin Polyolefins include those obtained by homopolymerizing or copolymerizing olefin monomers having 2 to 16 carbon atoms, preferably 2 to 12 carbon atoms, and hydrides of these polymers. The olefin monomers may be α-olefins, internal olefins, linear olefins, or branched olefins. Specific examples of such olefin monomers include ethylene, propylene, 1-butene, 2-butene, isobutene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, and hexadecene. and mixtures thereof.

• Alkylbenzene Alkylbenzenes preferably have 1 to 4 alkyl groups of 1 to 40 carbon atoms in the molecule. In addition, the alkyl group of alkylbenzene may be linear or branched, but a branched alkyl group is preferable from the viewpoint of stability, viscosity characteristics, etc., and is particularly easy to obtain. Therefore, branched alkyl groups derived from oligomers of olefins such as propylene, butene and isobutylene are more preferred.

As the base oil (A) of the water-soluble processed oil composition of the present embodiment, one of the mineral oils and/or synthetic oils described above may be used alone, or two or more may be used in combination. It is preferable to use the mineral oil mentioned above individually, or to mix and use 2 or more types.

The kinematic viscosity at 40° C. of the base oil (A) of the water-soluble processing oil composition of the present embodiment is preferably 4 mm ² /s or more, more preferably 6 mm ² /s or more, from the viewpoint of processability. It is preferably 8 mm ² /s or more.
In addition, the kinematic viscosity of the base oil (A) at 40° C. is preferably 100 mm ² /s or less, more preferably 80 mm ² /s or less, and still more preferably 60 mm, from the viewpoint of removability of the composition after processing. ² /s or less.
In one embodiment, the kinematic viscosity of the base oil (A) at 40° C. is preferably 4 mm ² /s or more and 100 mm ² /s or less, more preferably 6 mm ² /s or more and 80 mm ² /s or less, and still more preferably It is 8 mm ² /s or more and 60 mm ² /s or less.

The content of the base oil (A) in the water-soluble processing oil composition of the present embodiment is preferably 1% by mass or more, and preferably 3% by mass or more, relative to the total amount of the water-soluble processing oil composition. More preferably, it is 5% by mass or more.
The content of the base oil (A) is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, relative to the total amount of the water-soluble processing oil composition.
In one embodiment, the content of the base oil (A) is preferably 1% by mass or more and 50% by mass or less, and 3% by mass or more and 40% by mass or less, relative to the total amount of the water-soluble processing oil composition. is more preferable, and more preferably 5% by mass or more and 30% by mass or less.

<Silicone Antifoaming Agent (B)>
The silicone-based antifoaming agent (B) in the present embodiment is a synthetic polymer compound having a main skeleton formed of siloxane bonds (Si—O—Si bonds), and part of the synthetic polymer compound is polyalkylene oxide-modified. modified with a group, and the weight average molecular weight of the silicone antifoaming agent (B) is more than 26,000.
In the water-soluble processing oil composition of the present embodiment, the dispersibility of the silicone antifoaming agent (B) in the above-described base oil (A) is improved by configuring the silicone antifoaming agent (B) as described above. are improving.

The silicone antifoaming agent (B) in the water-soluble processing oil composition of the present embodiment preferably has a dimethylsilicone skeleton.

In the silicone antifoaming agent (B), the structural units modified with polyalkylene oxide modified groups and the non-modified structural units may be randomly repeated or alternately arranged, and may be of the same type. may be repeated continuously for a long time.

Specific examples of the silicone antifoaming agent (B) include a side chain-modified silicone antifoaming agent represented by the following general formula (b-1), and a side chain-modified silicone antifoaming agent represented by the following general formula (b-2). A double-end modified silicone antifoaming agent, a single end modified silicone antifoaming agent represented by the following general formula (b-3), and a side chain represented by the following general formula (b-4) Examples thereof include both terminal-modified silicone antifoaming agents.

［式中、Ｘは、それぞれ独立に、ポリアルキレンオキサイド変性基である。ｍ１～ｍ４は、それぞれ独立に、非変性の構成単位［－（ＣＨ_３）_２ＳｉＯ－］の繰返し数を示す。ｎ１～ｎ４は、それぞれ独立に、ポリアルキレンオキサイド変性基で変性された構成単位の繰返し数を示す。］

[In the formula, each X is independently a polyalkylene oxide modifying group. m1 to m4 each independently represent the number of repetitions of the unmodified structural unit [--(CH ₃ ) ₂ SiO--]. n1 to n4 each independently represent the number of repeating structural units modified with a polyalkylene oxide modifying group. ]

m1 to m4 and n1 to n4 in the above general formulas (b-1) to (b-4) are appropriately adjusted so that the weight average molecular weight of the silicone antifoaming agent (B) exceeds 26000. be.

The polyalkylene oxide-modified group is preferably a group represented by the following general formula (X-1).

［式中、Ｒ^１～Ｒ^３は、それぞれ独立に、アルキレン基である。ｐは、（－Ｏ－Ｒ^２－）の繰返し数を示す。ｑは、（－Ｏ－Ｒ^３－）の繰返し数を示す。＊は結合手を示す。］

[In the formula, R ¹ to R ³ are each independently an alkylene group. p represents the number of repetitions of (-OR ² -). q represents the number of repetitions of (-OR ³ -). * indicates a bond. ]

In general formula (X-1) above, R ¹ to R ³ are each independently an alkylene group.
The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and even more preferably an alkylene group having 1 to 4 carbon atoms.

Examples of linear alkylene groups having 1 to 4 carbon atoms include a methylene group, an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [-(CH ₂ ) ₃ -], and a tetramethylene group [-(CH ₂ ) _4- ].
The branched alkylene group having 2 to 4 carbon atoms includes -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )- and other alkylmethylene groups; -CH ₂ CH(CH ₃ )-, -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) Alkylethylene groups such as ₂ CH ₂ -- and --CH(CH ₂ CH ₃ )CH ₂ --; Alkyl trimethylene groups such as --CH(CH ₃ )CH ₂ CH ₂ -- and --CH ₂ CH(CH ₃ )CH ₂ -- and alkylalkylene groups such as groups.

In the above general formula (X-1), R ¹ to R ³ are each independently an ethylene group [-(CH ₂ ) ₂ -] or a propylene group {[-CH ₂ CH(CH ₃ )-] or [-CH(CH ₃ )CH ₂ -]} are preferred.

The number of repetitions of (-OR ² -) and the number of repetitions of (-OR ³ -) in p and q are, for example, as described later, that the molecular weight of the polyalkylene oxide modifying group is preferably 5000 or more. adjusted accordingly.

Among the above, the silicone antifoaming agent (B) in the water-soluble processing oil composition of the present embodiment is a dimethyl silicone modified with a group to which a polyethylene oxide group and a polypropylene oxide group are linked (hereinafter, "EOPO-modified dimethyl silicone ”) is preferable.

The weight average molecular weight of the silicone antifoaming agent (B) in the present embodiment is more than 26,000, preferably 30,000 or more, more preferably 35,000 or more, even more preferably 38,000 or more, and particularly preferably 40,000 or more.
On the other hand, the upper limit of the weight average molecular weight of the silicone antifoaming agent (B) is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 50,000 or less, and particularly preferably 45,000 or less.

If the weight average molecular weight of the silicone antifoaming agent (B) in the present embodiment is at least the above lower limit, the dispersibility of the silicone antifoaming agent (B) in the base oil (A) in the undiluted state is improved. . In addition, in the state diluted with water when subjected to processing, the insolubility of the silicone-based antifoaming agent (B) in water becomes appropriate, and the antifoaming effect is improved.
If the weight average molecular weight of the silicone-based antifoaming agent (B) in the present embodiment is equal to or less than the above preferable upper limit, the antifoaming effect is further improved.

In one embodiment, the weight average molecular weight (Mw) of the silicone antifoaming agent (B) is preferably 30000 or more and 100000 or less, more preferably 35000 or more and 70000 or less, even more preferably 38000 or more and 50000 or less, and 40000 or more and 45000 or less. Especially preferred.

The modification rate of the silicone antifoaming agent (B) in the present embodiment is preferably more than 0.12%, more preferably 0.15% or more, still more preferably 0.18% or more, and particularly 0.2% or more. preferable.
The modification rate of the silicone antifoaming agent (B) is preferably less than 2.38%, more preferably 2.0% or less, still more preferably 1.5% or less, and particularly preferably 1.0% or less.

If the modification rate of the silicone antifoaming agent (B) in the present embodiment is equal to or higher than the above preferable lower limit, the silicone antifoaming agent (B) diluted with water when subjected to processing Better dispersibility.
If the modification rate of the silicone antifoaming agent (B) in the present embodiment is equal to or less than the above preferable upper limit, the dispersibility of the silicone antifoaming agent (B) in the base oil (A) in the undiluted state is improve more.

In one embodiment, the modification rate of the silicone antifoaming agent (B) is preferably more than 0.12% and less than 2.38%, more preferably 0.15% or more and 2.0% or less, and 0.18% or more 1.5% or less is more preferable, and 0.2% or more and 1.0% or less is particularly preferable.

[Method for calculating modification rate of silicone antifoaming agent (B)]
Taking a silicone antifoaming agent (B0) having a structural unit represented by the following general formula (b-0) as an example, the method for calculating the modification rate of the silicone antifoaming agent (B) is shown below.

［式中、Ｘａは、ポリアルキレンオキサイド変性基である。ｍａは、非変性の構成単位［－（ＣＨ_３）_２ＳｉＯ－］の繰返し数を示す。ｎａは、ポリアルキレンオキサイド変性基により変性された構成単位の繰返し数を示す。］

[In the formula, Xa is a polyalkylene oxide modifying group. ma indicates the number of repetitions of the unmodified structural unit [--(CH ₃ ) ₂ SiO--]. na represents the number of repeating structural units modified with a polyalkylene oxide modifying group. ]

(i) In the structural unit modified by the polyalkylene oxide modifying group of the silicone antifoaming agent (B0), the peak area HxP attributed to the hydrogen atom Hx of _CH2 bonded to Si is measured by ¹ H-NMR. Determined by measurement. In the ¹ H-NMR measurement in the present invention, the peak area HxP obtained here is "2" because the peak area per hydrogen atom is regarded as "1". A value obtained by dividing the peak area HxP "2" by the number (2) of hydrogen atoms Hx is the number na of structural units modified with the polyalkylene oxide modifying group.

(ii) In the non-modified structural unit of the silicone antifoaming agent (B0), the peak area HyP attributed to the hydrogen atom Hy of CH ₃ bonded to Si is obtained by ¹ H-NMR measurement. From the peak area HyP, by subtracting the peak area "3" attributed to the hydrogen atom Hy of CH ₃ possessed by the structural unit modified with the polyalkylene oxide modifying group, the hydrogen atom Hy of CH ₃ possessed by the unmodified structural unit The peak area HyP1 attributed to can be calculated. Next, the value obtained by dividing this peak area HyP1 by the number (6) of hydrogen atoms Hy possessed by the non-modified structural units is the number ma of the non-modified structural units.

(iii) As shown by the following formula (1a), the number na of structural units modified with a polyalkylene oxide modifying group and the number ma of unmodified structural units are found by the calculations in (i) and (ii) above. A ratio can be calculated.
na:ma=2/2:(HyP-3)/6 (1a)

(iv) The modification rate of the silicone antifoaming agent (B0) can be obtained from the following formula (2a).
Modification rate (%) = na/(ma + na) x 100 (2a)

The measurement equipment and measurement conditions for the ¹ H-NMR measurement are as follows.
Apparatus used: AVANCE III HD-cryo600 type NMR manufactured by Bruker
¹ H resonance frequency: 600.18 MHz
Solvent: _CDCl3
Concentration: about 50 mg/mL
Measurement method: ¹ H non-decoupling method Pulse width: 30° pulse Waiting time: 5 sec
Chemical shift standard: _CHCl3 (7.28 ppm) in _CDCl3

The molecular weight of the polyalkylene oxide modified group of the silicone antifoaming agent (B) in the present embodiment is preferably 5,000 or more, more preferably 5,300 or more, still more preferably 5,500 or more, and particularly preferably 6,000 or more.
The molecular weight of the polyalkylene oxide modified group of the silicone antifoaming agent (B) is preferably 10,000 or less, more preferably 9,000 or less, even more preferably 8,000 or less, and particularly preferably 7,500 or less.

If the molecular weight of the polyalkylene oxide modified group of the silicone antifoaming agent (B) in the present embodiment is at least the above preferable lower limit, the silicone antifoaming agent in a water-diluted state when subjected to processing. The dispersibility of the agent (B) is further improved.
If the molecular weight of the polyalkylene oxide modified group of the silicone antifoaming agent (B) in the present embodiment is equal to or less than the above preferable upper limit, the silicone antifoaming agent (B ) dispersibility is further improved.

In one embodiment, the molecular weight of the polyalkylene oxide modified group of the silicone antifoaming agent (B) is preferably 5000 or more and 10000 or less, more preferably 5300 or more and 9000 or less, even more preferably 5500 or more and 8000 or less, and 6000 or more and 7500 or less. is particularly preferred.

[Method for calculating the molecular weight of the polyalkylene oxide modified group of the silicone antifoaming agent (B)]
The molecular weight of the polyalkylene oxide modifying group of the silicone antifoaming agent (B) can be calculated if the structure of the modifying group and the number of repeating alkylene oxide units are known.

Taking as an example a silicone antifoaming agent having a modifying group X0 represented by the following formula (x-0) as a modifying group, a method for calculating the molecular weight of the polyalkylene oxide modifying group of the silicone antifoaming agent (B) are shown below.

［式中、ｐａは、（－Ｏ－ＣＨ_２ＣＨ_２－）の繰返し数を示す。ｑａは、（－Ｏ－ＣＨ_２（ＣＨ_３）ＣＨ－）の繰返し数を示す。＊は結合手を示す。］

[In the formula, pa represents the number of repetitions of (--O--CH ₂ CH ₂ --). qa represents the number of repetitions of (--O--CH ₂ (CH ₃ )CH--). * indicates a bond. ]

(i) The repeating number qa of (-O-CH ₂ (CH ₃ )CH-) is, as shown in the following formula (ia), CH in the structural unit (-O-CH ₂ (CH ₃ )CH-) The peak area HdP attributed to the hydrogen atom Hd of ₃ is determined by ¹ H-NMR measurement, and can be calculated by dividing the peak area HdP by the number of hydrogen atoms Hd (3).
qa=HdP/3 (ia)

(ii) The repeating number pa of (—O—CH ₂ CH ₂ —) is, as shown in the following formula (iia), from the peak area HcP attributed to the hydrogen atom Hc to the peak area attributed to the hydrogen atom Hd It can be calculated by subtracting the peak area HaP attributed to HdP and the hydrogen atom Ha and dividing the resulting value by the number (4) of hydrogen atoms Hc in (--O--CH ₂ CH ₂ --).
pa = (HcP - HdP - HaP) / 4 (iia)

(iii) the modifying group X0 is, as shown in the following formula (iiia),
a molecular weight of 42 of (—CH ₂ CH ₂ CH ₂ —) bonded to the main chain of the silicone antifoaming agent (B);
a value obtained by multiplying the molecular weight 44 of (—O—CH ₂ CH ₂ —) by the repetition number pa obtained in (iia);
(—O—CH ₂ (CH ₃ )CH—) with a molecular weight of 58 multiplied by the repetition number qa obtained in (ia);
It can be calculated by adding the molecular weight 17 of the terminal --OH.
Molecular weight of modifying group X0 = 42 + 44 x pa + 58 x qa + 17 (iiia)

[Method for producing silicone antifoaming agent (B)]
The silicone antifoaming agent (B) of the present embodiment is, for example, a methylpolysiloxane containing a ≡SiH group, two or more polyoxyalkylene compounds having a vinyl group or an allyl group at the molecular chain end, and a carbon number It can be produced by addition reaction with 3 to 20 unsaturated olefins in the presence of a platinum catalyst.
Further, by adjusting the addition amount of the polyoxyalkylene compound and the reaction conditions, the modification rate of the silicone antifoaming agent (B) can be adjusted.
Further, by adjusting the type and degree of polymerization of the polyoxyalkylene compound, it is possible to adjust the molecular weight of the polyalkylene oxide modified group in the silicone antifoaming agent (B) described above.

The content of the silicone antifoaming agent (B) in the water-soluble processing oil composition of the present embodiment is preferably 0.0005% by mass or more with respect to the total amount of the water-soluble processing oil composition, and 0.001 It is more preferably 0.005% by mass or more, more preferably 0.005% by mass or more.
The content of the silicone antifoaming agent (B) is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, relative to the total amount of the water-soluble processing oil composition. .
In one embodiment, the content of the silicone antifoaming agent (B) is preferably 0.0005% by mass or more and 3% by mass or less with respect to the total amount of the water-soluble processing oil composition, and 0.001% by mass. It is more preferably at least 1% by mass, and even more preferably at least 0.005% by mass and not more than 0.5% by mass.

The content of the silicone antifoaming agent (B) in the water-soluble processing oil composition of the present embodiment is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the base oil (A). It is more preferably 5 parts by mass or more, and even more preferably 0.8 parts by mass or more.
In addition, the content of the silicone antifoaming agent (B) is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, with respect to 100 parts by mass of the base oil (A). Part or less is more preferable.
In one embodiment, the content of the silicone antifoaming agent (B) is preferably 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the base oil (A). Part or more and 3 mass parts or less are more preferable, and 0.8 mass part or more and 1 mass part or less is even more preferable.

The water-soluble processing oil composition of the present embodiment may contain one type of silicone antifoaming agent (B) alone, or two or more types thereof.

<Optional component>
The water-soluble processing oil composition of the present embodiment further contains components (optional components) other than the above-described base oil (A) and silicone antifoaming agent (B) within a range that does not impair the effects of the present invention. You may
Optional components include surfactant (C); extreme pressure agent (D); water (W); oiliness agent (E); rust inhibitor (F); anti-mist agents such as poly-α-olefin; metal deactivators such as benzotriazole and its derivatives; bactericides;
The water-soluble processing oil composition of the present embodiment comprises a base oil (A), a silicone antifoaming agent (B), a surfactant (C), an extreme pressure agent (D), water (W), and an oily agent. It preferably contains (E), a base oil (A), a silicone antifoaming agent (B), a surfactant (C), an extreme pressure agent (D), water (W), an oily agent (E), And it is more preferable to contain a rust preventive (F).

<<Surfactant (C)>>
The water-soluble processing oil composition of the present embodiment preferably further contains a surfactant (C).
Surfactant (C) is preferably a nonionic surfactant or an anionic surfactant, more preferably a nonionic surfactant.

Specific examples of nonionic surfactants include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, higher alkylamine ethylene oxide adducts, fatty acid esters of sorbitol and sorbitan, and sucrose fatty acid esters. , fluorine-based surfactants, Pluronic (registered trademark)-based surfactants, and the like.

Among the above nonionic surfactants, the water-soluble processing oil composition of the present embodiment preferably contains a pluronic surfactant.
Pluronic surfactants are triblock copolymer nonionic surfactants of hydrophilic ethylene oxide (EO) and hydrophobic propylene oxide (PO). By changing the EO polymerization degree/PO polymerization degree, the properties as a surfactant can be changed.

Specific examples of anionic surfactants include aliphatic carboxylates, sulfonates, sulfate ester salts, and phosphate ester salts.

When the water-soluble processing oil composition of the present embodiment contains a surfactant (C), the content of the surfactant (C) is 15% by mass or more with respect to the total amount of the water-soluble processing oil composition. It is preferably 20% by mass or more, more preferably 25% by mass or more.
Moreover, the content of the surfactant (C) is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, relative to the total amount of the water-soluble processing oil composition.
In one embodiment, the content of the surfactant (C) is preferably 15% by mass or more and 40% by mass or less, more preferably 20% by mass or more and 35% by mass or less, relative to the total amount of the water-soluble processing oil composition. 25% by mass or more and 30% by mass or less is more preferable.

The water-soluble processing oil composition of the present embodiment may contain one type of surfactant (C) alone, or may contain two or more types.

<<Extreme pressure agent (D)>>
The water-soluble processing oil composition of the present embodiment preferably further contains an extreme pressure agent (D).
Specific examples of the extreme pressure agent (D) include dihydrocarbyl polysulfide, sulfurized ester (including sulfurized ester oil), sulfurized fatty acid, sulfurized mineral oil, zinc dithiophosphate compound, zinc dithiocarbamate compound, molybdenum dithiophosphate compound and dithiocarbamine. molybdenum acid and the like.

As the extreme pressure agent (D) of the water-soluble processed oil composition of the present embodiment, among the above, a sulfurized fatty acid is preferable. Specific examples of sulfurized fatty acids include oleic acid, linoleic acid, fatty acids extracted from animal and vegetable oils, and mixtures thereof that are sulfurized by any method. Among them, oleic acid sulfide is preferable as the extreme pressure agent (D).

When the water-soluble process oil composition of the present embodiment contains the extreme pressure agent (D), the content of the extreme pressure agent (D) is 3% by mass or more with respect to the total amount of the water-soluble process oil composition. Preferably, it is 5% by mass or more, and even more preferably 10% by mass or more.
The content of the extreme pressure agent (D) is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, relative to the total amount of the water-soluble processing oil composition.
In one embodiment, the content of the extreme pressure agent (D) is preferably 3% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 20% by mass or less, relative to the total amount of the water-soluble processing oil composition. 10% by mass or more and 15% by mass or less is more preferable.

The water-soluble processing oil composition of the present embodiment may contain one type of extreme pressure agent (D) alone, or two or more types thereof.

≪Water (W)≫
The water-soluble processing oil composition of the present embodiment preferably further contains water (W).
Water (W) includes tap water, industrial water, pure water, deionized water, ion-exchanged water, well water, and water absorbed from the atmosphere.

When the water-soluble processing oil composition of the present embodiment contains water (W), the content of water (W) is preferably 10% by mass or more with respect to the total amount of the water-soluble processing oil composition, and 15 mass % or more is more preferable, and 20% by mass or more is even more preferable.
The content of water (W) is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, relative to the total amount of the water-soluble processing oil composition.
In one embodiment, the content of water (W) is preferably 10% by mass or more and 35% by mass or less, more preferably 15% by mass or more and 30% by mass or less, relative to the total amount of the water-soluble processing oil composition, and 20% by mass. % or more and 25 mass % or less is more preferable.

<<Oil-based agent (E)>>
The water-soluble processing oil composition of the present embodiment preferably further contains an oiliness agent (E).
Specific examples of oily agents (E) include nitrogen-containing compounds, and more specific examples include ethylamine, n-propylamine, n-butylamine, 1-ethylbutylamine, 1,3-diaminopropane, and cyclohexylamine. Primary amines such as diethylamine, di-n-propylamine, di-n-butylamine, 4,4′-diaminodiphenylamine, diethylenetriamine, tetraethylenepentamine, N-(2-aminoethyl)ethanolamine Secondary amine; Tertiary amine such as dimethylethylamine, diethylmethylamine, triethylamine, tributylamine, triisopropylamine, dicyclohexylmethylamine; N,N-dibutylaniline, N,N-dihexylaniline, 2,6-diisopropylaniline , 2,4,6-tri(t-butyl)aniline; and alkanolamines such as diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine and dibutanolamine.

Among the above, the oily agent (E) in the water-soluble processed oil composition of the present embodiment is preferably an alkanolamine, such as diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, dibutanolamine, or , more preferably a mixture thereof, more preferably diisopropanolamine.

When the water-soluble processing oil composition of the present embodiment contains the oily agent (E), the content of the oily agent (E) is preferably 3% by mass or more with respect to the total amount of the water-soluble processing oil composition, 5% by mass or more is more preferable, and 8% by mass or more is even more preferable.
The content of the oily agent (E) is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, relative to the total amount of the water-soluble processing oil composition.
In one embodiment, the content of the oily agent (E) is preferably 3% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 20% by mass or less, relative to the total amount of the water-soluble processing oil composition. % or more and 15 mass % or less is more preferable.

When the water-soluble processing oil composition of the present embodiment contains the extreme pressure agent (D) and the oil agent (E), the content of the oil agent (E) is the content of the extreme pressure agent (D) 100 mass It is preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and even more preferably 50 parts by mass or more.
In addition, the content of the oily agent (E) is preferably 300 parts by mass or less, more preferably 250 parts by mass or less, and even more preferably 200 parts by mass or less with respect to 100 parts by mass of the extreme pressure agent (D). .
In one embodiment, the content of the oily agent (E) is preferably 30 parts by mass or more and 300 parts by mass or less, and 40 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the extreme pressure agent (D). is more preferable, and 50 parts by mass or more and 200 parts by mass or less is even more preferable.

The water-soluble processing oil composition of the present embodiment may contain one type of oily agent (E) alone, or may contain two or more types.

≪Antirust agent (F)≫
The water-soluble processing oil composition of the present embodiment preferably further contains a rust inhibitor (F).
Specific examples of the rust inhibitor (F) include polyhydroxy fatty acids, alkyl or alkenyl succinic acid derivatives, polyhydric alcohol partial esters, metal sulfonates, and amines.

As the rust inhibitor (F) in the water-soluble processing oil composition of the present embodiment, among the above, polyhydroxy fatty acids are preferable, and dimers of 1,2-hydroxystearic acid, 1,2-hydroxy More preferred is a trimer of stearic acid or a mixture of said dimers and trimers.

When the water-soluble working oil composition of the present embodiment contains the rust inhibitor (F), the content of the rust inhibitor (F) is 5% by mass or more with respect to the total amount of the water-soluble working oil composition. It is preferably 10% by mass or more, more preferably 15% by mass or more.
The content of the rust preventive (F) is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, relative to the total amount of the water-soluble working oil composition.
In one embodiment, the content of the rust inhibitor (F) is preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 25% by mass or less, relative to the total amount of the water-soluble working oil composition. 15% by mass or more and 20% by mass or less is more preferable.

The water-soluble processing oil composition of the present embodiment may contain one rust preventive agent (F) alone, or may contain two or more kinds thereof.

The water-soluble processing oil composition of the present embodiment described above includes a base oil (A) and a silicone antifoaming agent (B ) and
The silicone antifoaming agent (B) is modified with a polyalkylene oxide modifying group so as to increase its hydrophilicity, and its weight-average molecular weight is controlled to more than 26,000 so as not to increase its hydrophilicity too much. As a result, in the undiluted state, the silicone antifoaming agent (B) is well dispersed in the base oil (A). The silicone antifoaming agent (B) is well dispersed in the oil (A).
Therefore, in the water-soluble processing oil composition of the present embodiment, the silicone antifoaming agent (B) has good dispersibility in both the undiluted state and the state diluted with water when subjected to processing. , it is possible to maintain the anti-foaming property.

Water-soluble containing base oil (A), silicone antifoaming agent (B), surfactant (C), extreme pressure agent (D), oily agent (E), and water (W) of one embodiment In the processing oil composition, foaming can be further suppressed while improving processability.
Since the silicone antifoaming agent (B) has moderate hydrophobicity in the undiluted state, for example, it has a low affinity for water in a micelle state. It is assumed that
When it is diluted with water during processing, it forms a so-called O/W emulsion in which the amount of the oily component is small relative to the amount of water. Since the silicone antifoaming agent (B) has moderate hydrophobicity, it is presumed that it is likely to be included in the microemulsion of the oily component, resulting in a state of being dispersed in water.
On the other hand, for example, when the hydrophilicity of the silicone antifoaming agent (B) is too high, the tendency of the silicone antifoaming agent (B) to aggregate near the interface between water and the oily component increases, and the oily component becomes It is presumed that when the microemulsion is formed, it is divided into those contained in the oily component and those not contained, and the dispersibility of the silicone antifoaming agent (B) deteriorates, resulting in poor antifoaming properties. be.

The water-soluble working oil composition of this embodiment is useful for cutting or grinding metal work materials.
Specific examples of the metal work material include work materials containing one or more metals selected from the group consisting of aluminum, aluminum alloys, copper, copper alloys, iron, and iron alloys.
A specific example of the iron alloy is stainless steel.

(Metal processing method)
The metal working method of the present embodiment includes a dilution step of diluting the water-soluble working oil composition of the above-described embodiment with water, and a working step of working metal using the diluted water-soluble working oil composition. have

[Dilution process]
The dilution step is a step of diluting the water-soluble process oil composition of the embodiment described above with water.
Water in the dilution step includes the same water (W) in the water-soluble processed oil composition of the above-described embodiment.

From the viewpoint of cooling performance, the dilution ratio of the water-soluble processing oil composition is preferably 5 times or more, more preferably 7 times or more, and still more preferably 10 times or more in volume ratio with respect to the water-soluble processing oil composition.
From the standpoint of workability, the dilution ratio of the water-soluble processing oil composition is preferably 50 times or less, more preferably 40 times or less, and still more preferably 30 times or less in terms of volume ratio with respect to the water-soluble processing oil composition. be.
In one embodiment, the dilution ratio of the water-soluble processing oil composition in the dilution step is preferably 5 times or more and 50 times or less, more preferably 7 times or more and 40 times or less, in terms of volume ratio with respect to the water-soluble processing oil composition. It is preferably 10 times or more and 30 times or less.

If the dilution ratio of the water-soluble processing oil composition in the dilution step is within the above preferred range, a large change in the viscosity of the diluted water-soluble processing oil composition, a reverse phase of the emulsion, etc. do not occur, and the water-soluble processing oil The concentration of each component of the composition becomes sufficient, and the metal working becomes more stable.

[Process]
The working step is a step of working a metal using the diluted water-soluble working oil composition.
Examples of the metal include aluminum, aluminum alloys, copper, copper alloys, iron, iron alloys, and metals containing two or more thereof.
A specific example of the iron alloy is stainless steel.

The processing includes, for example, cutting or grinding, and known devices can be used for cutting or grinding.

Since the water-soluble working oil composition of the embodiment described above is used in the metal working method of the present embodiment, foaming of the water-soluble working oil composition during working is suppressed, and stable metal working can be performed. can be done.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

<Preparation of base oil (A)>
A base oil (mineral oil) having physical properties shown in Table 1 below was prepared. "-" in Table 1 means that the value was below the detection limit.

[Measurement of 40° C. kinematic viscosity of base oil (A) and water-soluble processing oil composition]
Table 1 shows the kinematic viscosity (mm ² /s) of the base oil (A) at 40° C. measured according to JIS K 2283:2000. Similarly, Tables 3 to 5 show the kinematic viscosity (mm ² /s) at 40° C. of the water-soluble processing oil composition of each example.

<Preparation of silicone antifoaming agent>
Silicone antifoaming agents (B1) to (B12), (X1), and (X2) having physical properties shown in Table 2 were prepared.
(B1) to (B12): EOPO-modified dimethyl silicone (X1): EOPO-modified dimethyl silicone (X2): dimethyl silicone

[Measurement of weight average molecular weight (Mw) of silicone antifoaming agent]
The weight average molecular weights (Mw) of the polystyrene equivalent values of the silicone antifoaming agents (B1) to (B12), (X1), and (X2) were measured by gel permeation chromatography under the following measurement equipment and measurement conditions. (GPC). The results are shown in Table 2.
<<Weight average molecular weight Mw measuring device and measurement conditions>>
Apparatus used: Prominence series manufactured by Shimadzu Corporation Detector: RID-10A
Column: Shodex KF-405LHQ
Mobile phase: THF
Flow rate: 0.5mL/min
Concentration: 5,000mg/L
Calibrator: Polystyrene

[Measurement of molecular weight of polyalkylene oxide modified group of silicone antifoaming agent]
The molecular weights of the polyalkylene oxide modified groups of the silicone antifoaming agents (B1) to (B12) and (X1) were calculated in the same manner as described above.
The polyalkylene oxide modified groups of the silicone antifoaming agents (B1) to (B12) and the silicone antifoaming agent (X1) are all represented by the following formula (x-0).
For the peak area HaP attributed to the hydrogen atom Ha, an integrated value of 0.4 to 0.5 ppm was adopted.
The integrated value of 3.0 to 4.0 ppm was adopted for the peak area HcP attributed to the hydrogen atom Hc.
The integrated value of 1.0 to 1.5 ppm was adopted for the peak area HdP attributed to the hydrogen atom Hd.

［式中、ｐａは、（－Ｏ－ＣＨ_２ＣＨ_２－）の繰返し数を示す。ｑａは、（－Ｏ－ＣＨ_２（ＣＨ_３）ＣＨ－）の繰返し数を示す。＊は結合手を示す。］

[In the formula, pa represents the number of repetitions of (--O--CH ₂ CH ₂ --). qa represents the number of repetitions of (--O--CH ₂ (CH ₃ )CH--). * indicates a bond. ]

The molecular weights of the polyalkylene oxide modified groups of the silicone antifoaming agents (B1) to (B12) and the silicone antifoaming agent (X1) were calculated using the following formula (1).
Molecular weight of polyalkylene oxide modifying group = number of repetitions of pa x 44 + number of repetitions of qa x 58 + 42 + 17 (1)
The results are shown in Table 2.

[Measurement of Modification Rate of Silicone Defoamer]
Polyalkylene oxide modification rates of the silicone antifoaming agents (B1) to (B12) and (X1) were calculated in the same manner as described above.
The structural units of the silicone antifoaming agents (B1) to (B12) and the silicone antifoaming agent (X1) differ in the number of repetitions, but are all structural units represented by the following formula (s-0). be.
For the peak area HxP attributed to hydrogen atoms Hx, an integrated value of 0.4 to 0.5 ppm was adopted.
For the peak area HcP attributed to the hydrogen atom Hy, an integrated value of -0.5 to 0.4 ppm was adopted.

［式中、Ｘ_０は、上記式（ｘ－０）で表される基である。ｍ０は、非変性の構成単位［－（ＣＨ_３）_２ＳｉＯ－］の繰返し数を示す。ｎ０は、上記式（ｘ－０）で表される基で変性された構成単位の繰返し数を示す。］

[In the formula, X ₀ is a group represented by the above formula (x-0). m0 represents the number of repetitions of the unmodified structural unit [--(CH ₃ ) ₂ SiO--]. n0 represents the number of repeating structural units modified with the group represented by the above formula (x-0). ]

Modification ratios of polyalkylene oxide modified groups of silicone antifoaming agents (B1) to (B12) and (X1) were calculated using the following formula (2).
Denaturation rate = n0/(m0+n0) x 100 (2)
The results are shown in Table 2.

<Preparation of Surfactant (C), Extreme Pressure Agent (D), Water (W), Oily Agent (E), and Antirust Agent (F)>
Surfactant (C), extreme pressure agent (D), water (W), oiliness agent (E) and rust preventive (F) shown below were prepared.
Surfactant (C1): Pluronic PAG (molecular weight 2650)
Extreme pressure agent (D1): Sulfurized oleic acid Water (W): Ion-exchanged water Oily agent (E1): Diisopropanolamine Rust inhibitor (F1): 1,2-hydroxystearic acid dimer, trimer mixture

<Production of water-soluble processing oil composition>
The above base oil (A), silicone antifoaming agent (B), surfactant (C), extreme pressure agent (D), water (W), oily agent (E), and rust inhibitor (F) were mixed at the ratios shown in Tables 3 to 5 to produce water-soluble processed oil compositions of each example.

[foaming test 1]
(1) The water-soluble processing oil composition of each example produced by the above method was diluted 10-fold with deionized water to prepare a sample of each example.
(2) As shown in FIG. 1, a circulation pump P was used to circulate 500 mL of each example sample in a 1000 mL graduated cylinder. The position of the tip of the nozzle from which the sample was ejected in each example was the position of the opening of the 1000 mL graduated cylinder.
(3) After 20 minutes had passed since the circulation, the height of the foam was read from the scale of the graduated cylinder, and the circulation pump P was stopped.
(4) The foaming height (mm) was obtained by subtracting the scale of the graduated cylinder for the height of the liquid surface before starting circulation from the scale of the graduated cylinder for the foam height read in (3). The results are shown in Tables 3-5.

[Foam test 2 (stability test)]
(a) 20 L of the water-soluble processing oil composition of each example produced by the above method was allowed to stand at room temperature (25° C.) for 1 month in a 20 L can.
(b) 100 mL was sampled from the upper portion of the water-soluble processed oil composition of each example that had been allowed to stand, and diluted 10-fold with deionized water to be used as a sample.
The foaming height (mm) of the sample of each example was obtained in the same procedure as (2) to (4) of [foaming test 1]. The results are shown in Tables 3-5.

In Tables 3 to 5, the numerical values of base oil (A), antifoaming agent, surfactant (C), extreme pressure agent (D), oiliness agent (E), and rust preventive agent (F) are water-soluble It is the content (% by mass) with respect to 100% by mass of the total amount of the processing oil composition.

As shown in Tables 3 to 5, the water-soluble processing oil compositions of Examples had lower foaming heights in foaming tests 1 and 2 than the water-soluble processing oil compositions of Comparative Examples. Moreover, especially the water-soluble processing oil compositions of Examples had a lower foaming height in foaming test 2 than the water-soluble processing oil compositions of Comparative Examples.

From the results of the foaming test 1, it was confirmed that the water-soluble processing oil compositions of Examples had good foaming suppression properties when diluted with water. This is attributed to the good dispersibility of the silicone antifoaming agent (B) in the water-soluble working oil composition of the example diluted with water. guessed.
Moreover, from the results of the foaming test 2, it was confirmed that the water-soluble processing oil compositions of Examples could maintain the foaming suppressing property even when left standing at room temperature (25°C) for one month. This is because the silicone-based antifoaming agent (B) in the water-soluble processing oil composition maintained good dispersibility even when the water-soluble processing oil composition of Examples was stored for a long period of time in an undiluted state. It is assumed that there is.

Among the water-soluble processing oil compositions of Examples, the water-soluble processing oil compositions of Examples 1-11 showed higher foaming in Foaming Tests 1 and 2 than the water-soluble processing oil compositions of Examples 12-14. Both were low in height.

In comparing the water-soluble processing oil compositions of Examples 1 to 11 and the water-soluble processing oil composition of Example 14, the silicone antifoaming agent (B12 ) has a low modification rate (modification rate: 0.12%) compared to other silicone antifoaming agents (B), so although the foaming height in foaming test 1 is low, the foaming height in foaming test 2 is low. was higher than the water-soluble processing oil compositions of Examples 1-11. That is, the water-soluble process oil compositions of Examples 1-11 maintained their antifoaming properties longer than the water-soluble process oil composition of Example 14.

In comparing the water-soluble processing oil compositions of Examples 1 to 11 and the water-soluble processing oil composition of Example 13, the silicone antifoaming agent (B11 ) had a higher modification rate (modification rate: 2.38%) than the other silicone antifoaming agent (B), so the foaming height in foaming tests 1 and 2 was both high. That is, the water-soluble process oil compositions of Examples 1 to 11 had better anti-foaming properties than the water-soluble process oil composition of Example 13, and maintained the anti-foaming properties for a longer period of time.

In comparing the water-soluble processing oil compositions of Examples 1 to 11 and the water-soluble processing oil composition of Example 12, the silicone antifoaming agent (B10 ) has a lower molecular weight (Mw) of the polyalkylene oxide modifying group than the other silicone antifoaming agent (B) (molecular weight (Mw) of the modifying group: 4580), so the foaming height of foaming tests 1 and 2 Both were high. That is, the water-soluble processed oil compositions of Examples 1 to 11 had better anti-foaming properties than the water-soluble processed oil composition of Example 12, and maintained the anti-foaming properties for a longer period of time.

Claims (8)

Containing a base oil (A) and a silicone antifoaming agent (B) modified with a polyalkylene oxide modifying group,
The water-soluble processing oil composition, wherein the silicone antifoaming agent (B) has a weight average molecular weight of more than 26,000. 2. The water-soluble processing oil composition according to claim 1, wherein the silicone antifoaming agent (B) has a modification rate of more than 0.12% and less than 2.38%. 3. The water-soluble processing oil composition according to claim 1, wherein the polyalkylene oxide modified group in the silicone antifoaming agent (B) has a molecular weight of 5,000 or more. The water-soluble processing oil according to any one of claims 1 to 3, further comprising one or more surfactants selected from the group consisting of nonionic surfactants and anionic surfactants. Composition. The water-soluble processing oil composition according to any one of claims 1 to 4, wherein the base oil (A) has a kinematic viscosity at 40°C of 10 mm ² /s or more and 100 mm ² /s or less. The water-soluble working oil composition according to any one of claims 1 to 5, which is used for cutting or grinding metal. 7. The water-soluble working oil composition of Claim 6, wherein the metal comprises one or more metals selected from the group consisting of aluminum, aluminum alloys, copper, copper alloys, iron, and iron alloys. A dilution step of diluting the water-soluble processed oil composition according to any one of claims 1 to 5 with water;
and a working step of working a metal using the diluted water-soluble working oil composition.

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