JP5150060B2 - Electrical discharge machining oil composition - Google Patents

Description

  The present invention relates to an electric discharge machining oil composition.

In the electric discharge machining method, an electrode (copper, graphite, etc.) and a conductive workpiece are opposed to each other with a narrow gap of several microns to several tens of microns in an insulating medium, and the machining power supply is passed through this gap. When a voltage is supplied in a pulsating manner, discharge occurs when the distance between the electrode and the workpiece is the interval at which discharge starts at that voltage, and the workpiece is processed with high accuracy.
Machining speed (machining efficiency) is a measure of how much power source capacity can be extracted, and machining accuracy (machining surface irregularities, ie, surface roughness, machining surface due to adhesion of combustion soot such as oil due to electric discharge) This is one of the basic performances in the electric discharge machining method.

Electric discharge machining oil used as an insulating medium has a great influence not only on machining accuracy but also on machining speed, and also disperses scattered machining powder that scatters molten metal generated by electric discharge machining. It plays important roles such as cooling the heated part by electric discharge machining and recovering insulation between the electrodes.
Conventionally, hydrocarbon-based solvents such as mineral oil, normal paraffin, and isoparaffin have been used as the base oil of such electric discharge machining oil (Patent Documents 1, 2, and 3).
Patent Literature 1: Japanese Patent Laid-Open No. 2001-115179 Patent Literature 2: Japanese Patent Laid-Open No. 2003-342595 Patent Literature 3: Japanese Patent Laid-Open No. 2005-154471

  In recent years, improvement of the working environment such as odor and rough skin, further improvement of the processing speed, particularly improvement of the processing speed at the time of high finishing have been demanded, and various studies have been conducted. However, sufficient effects have not been obtained with the conventional hydrocarbon solvents described above.

In order to solve the above problems, the present invention is selected from a Fischer-Tropsch (FT) synthesis process, a hydrocracking process of wax-containing components, and a hydrorefining process of components obtained from these processes. A kerosene fraction produced by a production process having at least one process, a density at 15 ° C. of 0.7 to 0.8 g / cm ³ , an n-paraffin content of 10 to 90% by mass , and aromatic An electrical discharge machining oil composition comprising a hydrocarbon oil having a content of 0 to 3% by volume , a naphthene content of 0 to 20% by volume , and a kinematic viscosity at 40 ° C. of 0.5 to 9 mm 2 / s provide.

  Disclosed is an electric discharge machining oil capable of improving the working environment such as odor and rough skin, further improving the processing speed, particularly at the time of high finishing.

Properties of Hydrocarbon Oil as Base Oil The electric discharge machining oil composition of the present invention has a density at 15 ° C. of 0.7 to 0.8 g / cm ³ , an n-paraffin content of 10 to 90%, and an aromatic content. Containing 0 to 3% of hydrocarbon oil and 0 to 20% of naphthene (hereinafter referred to as hydrocarbon oil of the present invention).
The density (g / cm < ³ >) in 15 degreeC of the hydrocarbon oil of this invention is 0.70-0.80, Preferably it is 0.72-0.79, More preferably, it is 0.73-0.785. If the density is lower than this range, the replenishment amount is increased. On the other hand, if the density is higher than this range, neither the cooling of the heated part, the scattering of the molten metal (working powder), or the prevention of removal is insufficient. The density in the present invention means a value measured according to JISK2249.
The n-paraffin content (% by mass) of the hydrocarbon oil of the present invention is 10-90%, preferably 20-80%, more preferably 30-70%. If it is less than this, there will be a problem in terms of odor.
In addition, n-paraffin content here means the value (dilution oil whole quantity reference | standard) measured using GC-FID. In the present invention, a capillary column of methyl silicon (ULTRAALLOY-1) is used for the column, helium is used for the carrier gas, a hydrogen ion detector (FID) is used for the detector, the column length is 30 m, the carrier gas flow rate is 1. An n-paraffin-containing standard sample was used under the conditions of 0 mL / min, split ratio 1:79, sample injection temperature 360 ° C., column temperature rising condition 140 ° C. → (8 ° C./min)→355° C., detector temperature 360 ° C. The n-paraffin content (based on the total amount of diluted oil) identified and quantified is shown, but the measurement conditions are not limited as long as equivalent results are obtained.

The content (volume%) of the aromatic component of the hydrocarbon oil of the present invention is 0-10%, preferably 0-3%, more preferably 0-2%, still more preferably 0-1%. If the aromatic content is high, odor is also emitted and skin irritation is exhibited, which is also undesirable because it leads to deterioration of the working environment.
The saturated hydrocarbon content (volume%) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 90-100%, more preferably 97-100%, still more preferably 98-100%, most preferably. Is 99-100%.
Although content (volume%) of the unsaturated part of the hydrocarbon oil of this invention is not specifically limited, Preferably it is 0-5%, More preferably, it is 0-3%, More preferably, it is 0-1%.
In addition, the saturated content, the unsaturated content, and the aromatic content referred to here are measured in accordance with the Petroleum Institute method JPI-5S-49-97 “hydrocarbon type test method—high performance liquid chromatograph method”. It means the volume percentage (volume%) (based on the total amount of diluent oil) of the aromatic content measured according to (published by the Japan Petroleum Institute).

The naphthene content (volume%) of the hydrocarbon oil of the present invention is 0-20%, preferably 0-10%, more preferably 0-5%. If the naphthene content is high, an odor is generated, which leads to deterioration of the working environment, which is not preferable.
The paraffin content (volume%) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 80-100%, more preferably 90-100%, still more preferably 95-100%, and most preferably 99-100. %.
Here, the paraffin content and naphthene content are measured in accordance with ASTM D2786 “Standard Test Method for Hydrocarbon Types Analysis of Gas-Oil Saturates Fractions by High Ionizing Voltage Mass Spectrometry”. It means volume percentage (volume%) (based on the total amount of saturation).

The kinematic viscosity (mm ² / s) of the hydrocarbon oil of the present invention is 0 . 5-9, good Mashiku is 1.0-5.5, good Ri preferably 1.2-5.0. If the kinematic viscosity is lower than this range, the replenishment amount may increase. On the other hand, if the kinematic viscosity is higher than this range, the cooling of the heated part may be poorly cooled, the molten metal (working powder) may be scattered, and prevention of removal may be insufficient. There is. The kinematic viscosity in the present invention means a value measured according to JISK2283.
The flash point (° C.) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 50-200, more preferably 55-150, and still more preferably 58-140. If the flash point is low, the risk of fire may increase, and if it is high, the removability may be poor. In addition, the flash point in the present invention means a value measured by a tag-sealed or pen-scheme-tensile sealed flash point test method in accordance with JIS K2265.
Although the aniline point (degreeC) of the hydrocarbon oil of this invention is not specifically limited, Preferably it is 65-110, More preferably, it is 70-110, More preferably, it is 75-110. In addition, the aniline point in this invention means the value measured by JISK2256.
The sulfur content (mass ppm) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 0-30, more preferably 0-10, still more preferably 0-5, and most preferably 0-1. If there is a lot of sulfur, the odor may get worse. In addition, the sulfur content in this invention means the value measured by JISK2541.

Distillation properties (° C.) of the hydrocarbon oil of the present invention are as follows according to Engler distillation (JIS K2254).
The initial boiling point (° C.) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 140 to 280, more preferably 150 to 275, still more preferably 160 to 270, and most preferably 165 to 265. . If it is low, the supply amount may increase.
The 10% distillation point (° C.) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 150-270, more preferably 160-285, still more preferably 170-280, and most preferably 180-275. .
The 50% distillation point (° C.) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 170-320, more preferably 180-310, still more preferably 190-300, and particularly preferably 195-290. It is.
The 90% distillation point (° C.) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 180-390, more preferably 190-370, still more preferably 200-340, particularly preferably 210-330. is there.
Although the end point (degreeC) of the hydrocarbon oil of this invention is not specifically limited, Preferably it is 190-400, More preferably, it is 200-380, More preferably, it is 210-350, Most preferably, it is 220-340.
_T 90 _{-T 10} hydrocarbon oils of the present invention (℃) is not particularly limited, preferably 15-160, more preferably 20-150, more preferably 30 to 140, particularly preferably from 35 to 135. When T ₉₀ -T ₁₀ (° C.) is narrow, the solubility of the additive may be inferior. On the other hand, when T ₉₀ -T ₁₀ (° C.) is wide, the replenishment amount increases, the cooling of the heated part is poor, the molten metal (work powder) is scattered Removal may be poor.
The EP-IBP (° C.) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 35 to 200, more preferably 40 to 190, still more preferably 50 to 180, and particularly preferably 60 to 170. If EP-IBP (° C) is narrow, the solubility of the additive is inferior. On the other hand, if the EP-IBP (° C.) is wide, the replenishment amount increases, the cooling of the heated part is poor, the molten metal (processed powder) is scattered, and the removal is poor. Neither is preferred.
The smoke point (mm) of the hydrocarbon oil of the present invention is not particularly limited, but is preferably 0-5, more preferably 0-3, and still more preferably 0-1. In addition, the smoke point in this invention means the value measured by JISK2537.

As mentioned above, although the hydrocarbon oil of this invention has been demonstrated, the following 1st aspect is mentioned as a more concrete preferable aspect.
In a preferred first embodiment, the initial boiling point (° C.) is preferably 140-260, preferably 150-255, more preferably 160-250, most preferably 165-245. If the initial boiling point is low, the supply amount may increase.
In a preferred first embodiment, the 10% distillation point (° C.) is preferably 150-270, preferably 160-265, more preferably 170-260, most preferably 180-255.
In a preferred first embodiment, the 90% distillation point (° C) is preferably 180-320, preferably 190-310, more preferably 200-300, most preferably 210-290.
In a preferred first embodiment, the end point (° C.) is preferably 190-310, preferably 200-300, more preferably 210-290, most preferably 220-280.

Hydrocarbon oils of the present invention has at least one step selected from the full I Tsu Shah Tropsch (FT) synthesis process, hydrocracking process of the wax-containing component and a hydrorefining process of components obtained from these steps Ru Ah in kerosene and gas oil fraction produced by the production process.
The FT synthesis process is a process in which a Fischer-Tropsch (FT) reaction is applied to a mixed gas containing hydrogen and carbon monoxide as main components (sometimes referred to as synthesis gas). Gas, naphtha, kerosene, light oil A liquid fraction corresponding to the boiling point range, paraffin wax (FT wax) and the like are obtained.
The hydrocracking process of the wax-containing component is a process of hydrocracking (which may include an isomerization reaction) a wax-containing component such as slack wax by-produced in the FT wax or lubricating oil dewaxing process. Yes, a liquid fraction, lubricating oil fraction, etc. corresponding to the boiling range of gas, naphtha, kerosene, and light oil can be obtained.
The hydrorefining step is a step of hydrorefining (which may include a hydrocracking / isomerization reaction) a component obtained from either or both of the above two steps.
In the present invention, the kerosene fraction obtained from each of the above steps may be used singly or as a mixture of two or more, and the kerosene fraction obtained from different above steps may be used as a mixture of two or more. May be.
Here, the kerosene oil fraction means a fraction having a boiling range in the range of 140 to 400 ° C., preferably 150 to 360 ° C. at normal pressure. For example, the kerosene fraction generally has a boiling point of 140 -300 degreeC, Preferably it exists in the range of 150-260 degreeC, and the light oil fraction has a boiling point in the range of 150-400 degreeC, Preferably it is in the range of 180-360 degreeC.

Below, each process of FT synthesis | combination, hydrorefining, and hydrocracking is demonstrated.
(FT synthesis process)
<Raw gas>
The mixed gas used as a raw material is a mixed gas mainly composed of hydrogen and carbon monoxide, and a substance containing carbon is oxidized using oxygen and / or water and / or carbon dioxide as an oxidizing agent, and further required. Accordingly, it is obtained by adjusting to a predetermined hydrogen and carbon monoxide concentration by a shift reaction using water. Substances containing carbon include natural gas, petroleum liquefied gas, methane gas, etc., gas components consisting of hydrocarbons that are gaseous at room temperature, petroleum asphalt, biomass, coal, waste such as building materials and garbage, sludge, In addition, mixed gas obtained by exposing heavy crude oil, unconventional petroleum resources, etc. that are difficult to process by ordinary methods to high temperatures is common, but mixed gas mainly composed of hydrogen and carbon monoxide As long as is obtained, the present invention does not limit the raw materials.

<Catalyst type>
A Fischer-Tropsch reaction requires a metal catalyst. As the metal catalyst, a Group 8 metal, for example, cobalt, ruthenium, rhodium, palladium, nickel, iron, or the like, more preferably a Group 8 metal of the fourth period is used as an active catalyst component. Moreover, the metal group which mixed these metals in an appropriate amount can also be used. These active metals are generally used in the form of a catalyst obtained by being supported on a support such as silica, alumina, titania or silica alumina. Further, by using these catalysts in combination with a second metal in addition to the above active metal, the catalyst performance can be improved. Examples of the second metal include alkali metal and alkaline earth metal, specifically sodium, lithium, magnesium, etc., as well as zirconium, hafnium, titanium, and the like. It is used appropriately according to the purpose, such as an increase in chain growth probability (α) as an index.

<Raw material mixed gas composition>
The Fischer-Tropsch reaction is a synthesis method for producing a liquid fraction and paraffin wax using a mixed gas as a raw material. In order to efficiently perform this synthesis method, it is generally preferable to control the ratio of hydrogen to carbon monoxide in the mixed gas. The molar mixing ratio of hydrogen and carbon monoxide is preferably 1.2: 1 or more, more preferably 1.5: 1, and even more preferably 1.8: 1 or more. This ratio is preferably 3: 1 or less, more preferably 2.6: 1 or less, and even more preferably 2.2: 1 or less.

<Reaction temperature>
When performing the Fischer-Tropsch reaction using the catalyst, the reaction temperature is preferably 180 ° C. or higher and 320 ° C. or lower, and more preferably 200 ° C. or higher and 300 ° C. or lower. When the reaction temperature is less than 180 ° C., carbon monoxide hardly reacts and the hydrocarbon yield tends to be low. On the other hand, when the reaction temperature exceeds 320 ° C., the amount of gas such as methane increases, and the production efficiency of the liquid fraction and paraffin wax decreases.

<Liquid space velocity>
No particular restriction on the gas hourly space velocity relative to the catalyst, but preferably 500h ^-1 or more 4000h ^-1 or less, 1000h ^-1 or more 3000h ^-1 or less is more preferable. If the gas space velocity is less than 500, the productivity of the liquid fuel tends to decrease. If the gas space velocity exceeds 4000 h ⁻¹ , the reaction temperature has to be increased and gas generation increases, resulting in a decrease in the yield of the target product. End up.

<Reaction pressure>
The reaction pressure (partial pressure of synthesis gas composed of carbon monoxide and hydrogen) is not particularly limited, but is preferably 0.5 MPa or more and 7 MPa or less, and more preferably 2 MPa or more and 4 MPa or less. If the reaction pressure is less than 0.5 MPa, the yield of the liquid fraction tends to decrease, and if it exceeds 7 MPa, the amount of capital investment tends to increase, which is uneconomical.

(Hydrorefining process, hydrocracking process)
The component obtained by the FT synthesis step and / or the wax-containing component is hydrorefined or hydrocracked by any method. Hydrorefining and hydrocracking may be selected in accordance with the purpose, and selection of only one or a combination of both methods is not limited in any way as long as the diluted oil of the present invention can be produced.

(Hydro-refining process)
This step is a step of hydrorefining mainly the component obtained by the FT synthesis step and / or the component obtained by the hydrocracking step of the wax-containing component described later. The reaction in this step may include a hydrogenolysis / isomerization reaction.
<Catalyst type>
A catalyst used for hydrorefining is generally a catalyst in which a hydrogenation active metal is supported on a porous carrier, but the present invention does not limit the form of the catalyst as long as the same effect can be obtained.
Examples of the porous carrier include inorganic oxides such as alumina. Specific examples of the inorganic oxide include alumina, titania, zirconia, boria, silica, and zeolite.
Zeolite is a crystalline aluminosilicate, and includes faujasite, pentasil, mordenite, etc., preferably faujasite, beta, mordenite, particularly preferably Y type and beta type. The Y type is preferably ultra-stabilized.

As the active metal, the following two types (active metal A type and active metal B type) are preferably used.
The active metal A type is at least one metal selected from Group 8 metals of the Periodic Table. Preferably, it is at least one selected from Ru, Rd, Ir, Pd, and Pt, and more preferably Pd or / and Pt. The active metal may be a combination of these metals. For example, Pt-Pd, Pt-Rh, Pt-Ru, Ir-Pd, Ir-Rh, Ir-Ru, Pt-Pd-Rh, Pt-Rh-Ru , Ir-Pd-Rh, Ir-Rh-Ru, and the like. When using a noble metal catalyst composed of these metals, it can be used after pre-reduction treatment in a hydrogen stream. In general, when a gas containing hydrogen is circulated and heat of 200 ° C. or higher is applied according to a predetermined procedure, the active metal on the catalyst is reduced, and hydrogenation activity is exhibited.
Further, as the active metal B type, it contains at least one metal selected from Group 6A and Group 8 metals of the periodic table, and preferably contains two or more metals selected from Groups 6A and 8 What you are doing can also be used. For example, Co-Mo, Ni-Mo, Ni-Co-Mo, and Ni-W can be mentioned. When a metal sulfide catalyst made of these metals is used, it is necessary to include a preliminary sulfidation step.

  As the metal source, a general inorganic salt or a complex salt compound can be used, and as a supporting method, any method of a supporting method used in an ordinary hydrogenation catalyst such as an impregnation method or an ion exchange method can be used. When a plurality of metals are supported, they may be supported simultaneously using a mixed solution, or may be sequentially supported using a single solution. The metal solution may be an aqueous solution or an organic solvent.

<Reaction temperature>
The reaction temperature when hydrorefining using the catalyst composed of the active metal A type is preferably 180 ° C. or higher and 400 ° C. or lower, more preferably 200 ° C. or higher and 370 ° C. or lower, more preferably 250 ° C. or higher. It is further preferably 350 ° C. or lower, and more preferably 280 ° C. or higher and 350 ° C. or lower. If the reaction temperature in hydrorefining exceeds 370 ° C., side reactions that decompose into naphtha fractions increase, and the yield of middle fractions is extremely undesirably reduced. On the other hand, when the reaction temperature is lower than 170 ° C., the alcohol component cannot be completely removed and is not preferable.
The reaction temperature when hydrotreating using a catalyst composed of the active metal B type is preferably 170 ° C. or higher and 320 ° C. or lower, more preferably 175 ° C. or higher and 300 ° C. or lower, and 180 ° C. or higher. It is still more preferable that it is 280 degrees C or less. If the reaction temperature in the hydrorefining exceeds 320 ° C., side reactions that decompose into naphtha fractions increase, and the yield of middle fractions is extremely undesirably reduced. On the other hand, when the reaction temperature is lower than 170 ° C., the alcohol component cannot be completely removed and is not preferable.

<Hydrogen pressure>
The hydrogen pressure when hydrotreating using a catalyst composed of the active metal A type is preferably 0.5 MPa or more and 12 MPa or less, and more preferably 1.0 MPa or more and 5.0 MPa or less. The higher the hydrogen pressure, the more hydrogenation reaction is promoted, but generally there is an optimal point economically.
The hydrogen pressure when hydrorefining using the catalyst composed of the active metal B type is preferably 2 MPa or more and 10 MPa or less, more preferably 2.5 MPa or more and 8 MPa or less, and 3 MPa or more and 7 MPa or less. Even more preferably. The higher the hydrogen pressure, the more hydrogenation reaction is promoted, but generally there is an optimal point economically.

<LHSV>
The liquid hourly space velocity which hydrorefining is carried out using a catalyst composed of the active metal A type (LHSV) is preferably at 0.1 h ^-1 or more 10.0H ^-1 or less, 0.3h ^-1 or 3 More preferably, it is 5 h ⁻¹ or less. The lower the LHSV, the more advantageous for the reaction. However, if the LHSV is too low, an extremely large reaction tower volume is required, resulting in excessive capital investment, which is not economical.
The liquid hourly space velocity which hydrorefining is carried out using a catalyst composed of the active metal B type (LHSV) is preferably at 0.1 h ^-1 or more ^{2h -1} or less, 0.2 h ^-1 or 1. more preferably 5h ^-1 or less, and still more preferably at 0.3h ^-1 or 1.2 h ^-1 or less. The lower the LHSV, the more advantageous for the reaction. However, if the LHSV is too low, an extremely large reaction tower volume is required, resulting in excessive capital investment, which is not economical.

<Hydrogen / oil ratio>
The hydrogen / oil ratio when hydrorefining using the catalyst composed of the active metal A type is preferably 50 NL / L or more and 1000 NL / L or less, and preferably 70 NL / L or more and 800 NL / L or less. More preferred. The higher the hydrogen / oil ratio, the more hydrogenation reaction is promoted, but generally there is an optimal point economically.
The hydrogen / oil ratio when hydrorefining using the catalyst composed of the active metal B type is preferably 100 NL / L or more and 800 NL / L or less, and preferably 120 NL / L or more and 600 NL / L or less. More preferably, it is 150 NL / L or more and 500 NL / L or less. The higher the hydrogen / oil ratio, the more hydrogenation reaction is promoted, but generally there is an optimal point economically.

(Hydrolysis process)
This step is a step of hydrocracking the wax-containing component, preferably the FT wax. The reaction in this step may include an isomerization reaction.
<Catalyst type>
The catalyst used for hydrocracking is generally one in which a hydrogenation active metal is supported on a carrier having a solid acid property, but the present invention does not limit the form of the catalyst as long as the same effect can be obtained. Absent.
Supports having a solid acid property include amorphous and crystalline zeolites. Specific examples include amorphous silica-alumina, silica-magnesia, silica-zirconia, silica-titania and zeolite faujasite type, beta type, MFI type, and mordenite type. Preferred are faujasite type, beta type, MFI type, and mordenite type zeolite, and more preferred are Y type and beta type. The Y type is preferably ultra-stabilized.

As the active metal, the following two types (active metal C type and active metal D type) are preferably used.
The active metal C type is mainly at least one metal selected from Group 6A and Group 8 metals of the Periodic Table. Preferably, it is at least one metal selected from Ni, Co, Mo, Pt, Pd, and W. When using a noble metal catalyst composed of these metals, it can be used after pre-reduction treatment in a hydrogen stream. In general, when a gas containing hydrogen is circulated and heat of 200 ° C. or higher is applied according to a predetermined procedure, the active metal on the catalyst is reduced, and hydrogenation activity is exhibited.
The active metal D type may be a combination of these metals, such as Pt—Pd, Co—Mo, Ni—Mo, Ni—W, and Ni—Co—Mo.
Moreover, when using the catalyst which consists of these metals, it is preferable to use after pre-sulfiding.

  As the metal source, a general inorganic salt or a complex salt compound can be used, and as a supporting method, any method of a supporting method used in an ordinary hydrogenation catalyst such as an impregnation method or an ion exchange method can be used. When a plurality of metals are supported, they may be supported simultaneously using a mixed solution, or may be sequentially supported using a single solution. The metal solution may be an aqueous solution or an organic solvent.

<Reaction temperature>
The reaction temperature when performing hydrocracking using a catalyst composed of the active metal C type and the active metal D type is preferably 200 ° C. or higher and 450 ° C. or lower, more preferably 250 ° C. or higher and 430 ° C. or lower. It is more preferably 300 ° C. or higher and 400 ° C. or lower. When the reaction temperature in hydrocracking exceeds 370 ° C., side reactions that decompose into a naphtha fraction increase and the yield of the middle fraction is extremely reduced, which is not preferable. On the other hand, when the temperature is lower than 200 ° C., the activity of the catalyst is remarkably lowered, which is not preferable.

<Hydrogen pressure>
The hydrogen pressure when hydrocracking using a catalyst comprising the above active metal C type and active metal D type is preferably 1 MPa or more and 20 MPa or less, more preferably 4 MPa or more and 16 MPa or less, and 6 MPa or more. Even more preferably, it is 13 MPa or less. The higher the hydrogen pressure is, the more hydrogenation reaction is promoted. However, the decomposition reaction rather slows down and the progress of the reaction needs to be adjusted by increasing the reaction temperature, leading to a decrease in catalyst life. For this reason, there is generally an economical optimum for the reaction temperature.

<LHSV>
The liquid hourly space velocity which hydrocracking is carried out using a catalyst composed of the active metal type C (LHSV) is preferably at 0.1 h ^-1 or more ^{10h -1} or less, 0.3h ^-1 or 3. More preferably, it is 5h- ¹ or less. The lower the LHSV, the more advantageous for the reaction. However, if the LHSV is too low, an extremely large reaction tower volume is required, resulting in excessive capital investment, which is not economical.
The liquid hourly space velocity which hydrocracking is carried out using a catalyst composed of the active metal type D (LHSV) is preferably at 0.1 h ^-1 or more ^{2h -1} or less, 0.2 h ^-1 or 1. more preferably 7h ^-1 or less, and still more preferably at 0.3h ^-1 or more 1.5Hh ^-1 or less. The lower the LHSV, the more advantageous for the reaction. However, if the LHSV is too low, an extremely large reaction tower volume is required, resulting in excessive capital investment, which is not economical.

<Hydrogen / oil ratio>
The hydrogen / oil ratio when hydrocracking using a catalyst composed of the above active metal C type is preferably 50 NL / L or more and 1000 NL / L or less, and preferably 70 NL / L or more and 800 NL / L or less. More preferably, it is 400 NL / L or more and 1500 NL / L or less. The higher the hydrogen / oil ratio, the more hydrogenation reaction is promoted, but generally there is an optimal point economically.
The hydrogen / oil ratio when hydrocracking using the catalyst composed of the active metal D type is preferably 150 NL / L or more and 2000 NL / L or less, and preferably 300 NL / L or more and 1700 NL / L or less. More preferably, it is still more preferably 400 NL / L or more and 1500 NL / L or less. The higher the hydrogen / oil ratio, the more hydrogenation reaction is promoted, but generally there is an optimal point economically.

<Device>
The apparatus for hydrotreating may be of any configuration, the reaction towers may be used alone or in combination, hydrogen may be additionally injected between the reaction towers, gas-liquid separation operation, hydrogen sulfide removal equipment, hydrogen It may have a distillation column for fractionating the chemical product and obtaining the desired fraction.
The reaction format of the hydrotreating apparatus of the present invention can be a fixed bed system. Hydrogen can take either a countercurrent or a cocurrent flow with respect to the feedstock, and may have a plurality of reaction towers and a combination of countercurrent and cocurrent flow. The general format is downflow, and there is a gas-liquid twin parallel flow format. Hydrogen gas may be injected into the middle stage of the reaction tower as a quench for the purpose of removing reaction heat or increasing the hydrogen partial pressure.
A kerosene oil fraction produced by the production process having at least one process selected from the Fischer-Tropsch synthesis process, the hydrocracking process of the wax-containing component, and the hydrorefining process of the component obtained from these processes as described above. Can be used as the hydrocarbon oil of the present invention.

  The present invention contains the hydrocarbon oil of the present invention as an essential component of the base oil, but besides this, any of mineral oil, synthetic oil and oil can be used together, and there is no limitation on the type, For combined use, mineral oil or synthetic oil is particularly preferred. The combination ratio is not particularly limited and can be arbitrarily selected as long as the effects of the present invention are not impaired. However, the content of the hydrocarbon oil of the present invention is 60% by mass or more based on the total amount of the electric discharge machining oil composition. It is preferably 80% by mass or more, and most preferably 95% by mass or more. The content of the base oil other than the hydrocarbon oil of the present invention is preferably 40% by mass or less, more preferably 20% by mass or less, and more preferably 5% by mass based on the total amount of the electric discharge machining oil composition. Most preferably:

  Specific examples of mineral oils that can be used in combination include kerosene fractions obtained by distillation of paraffinic or naphthenic crude oils; normal paraffins obtained by extraction operations from kerosene fractions; and paraffinic or naphthenic crude oils. The lubricating oil fraction obtained by distillation is appropriately combined with one or more of solvent purification, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment. And purified.

  In addition, as synthetic oils that can be used in combination, specifically, for example, poly-α-olefin (propylene oligomer, isobutylene oligomer, polybutene, 1-octene oligomer, 1-decene oligomer, ethylene-propylene oligomer, etc.) or a hydride thereof. , Alkylbenzene, alkylnaphthalene, diester (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropane pelargo , Pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyglycol, silicone oil, dialkyldiphenyl ether , Polyphenyl ether, polyalkylene glycol, and the like. The synthetic oil usually called isoparaffin includes propylene oligomer hydride, isobutylene oligomer hydride and polybutene hydride.

  Among the above synthetic oils, any alkylbenzene can be used, but those having one or two alkyl groups are preferable, and those having one alkyl group are more preferable. Moreover, the carbon number of the alkyl group which alkylbenzene has becomes like this. Preferably it is 8-40, More preferably, 8-24 are preferable. When the carbon number of the alkyl group is less than 8, volatility may increase, and when it exceeds 40, the performance of the electric discharge machining oil as a base oil may be insufficient. The alkyl group may be linear or branched, but is preferably a branched alkyl group from the viewpoint of work safety. The alkylbenzene may be a single structure alkylbenzene or a mixture of two or more alkylbenzenes having different structures.

  In this invention, in order to use together, 1 type of the said mineral oil or synthetic oil may be sufficient, or 2 or more types of mixtures may be used together. Moreover, the combination in the base oil used together may be any of mineral oils, synthetic oils, or a combination of mineral oil and synthetic oil. Furthermore, although the mixing ratio can be selected as appropriate, it is desirable to select the mixing ratio so that the kinematic viscosity of the mixed base oil at 40 ° C. falls within a preferable range described later.

  The content of the base oil is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, and most preferably 70% by mass or more, based on the total amount of the composition. On the other hand, the base oil content is preferably 99.85% by mass or less based on the total amount of the composition, more preferably, in order to facilitate the removal of processing waste and tar-like substances that stay between the electrodes. It is 99.5 mass% or less, Most preferably, it is 99.0 mass% or less.

  The electric discharge machining oil composition of the present invention may contain (A) a compound having two or more hydroxyphenyl groups (hereinafter, sometimes referred to as component (A)).

  Each of the hydroxyphenyl groups of the component (A) may be substituted or unsubstituted, but is preferably substituted with an alkyl group having 1 to 4 carbon atoms. In addition, the number of substituents in the case where each of the hydroxyphenyl groups of the component (A) is substituted with an alkyl group having 1 to 4 carbon atoms is not particularly limited, but as the component (A), each hydroxyphenyl group Preferably, the compound has at least one alkyl group, and more preferably has at least two alkyl groups. In addition, the compound used in the present invention may be a compound having 3 or more hydroxyphenyl groups, but is preferably a compound having 2 hydroxyphenyl groups because the production of tar-like substances can be further suppressed. Furthermore, in the plurality of hydroxyphenyl groups, the phenyl groups may be directly bonded to each other or may be bonded via a hydrocarbon group, or a bonding group containing atoms other than carbon and hydrogen such as oxygen and sulfur. It may be connected via. Examples of the linking group containing oxygen and / or sulfur include —S—, —O—C (═O) —, and a combination of these with a hydrocarbon group. Among these linking groups, since generation of a tar-like substance can be further suppressed, a group containing oxygen, a group containing sulfur, or a group containing oxygen and sulfur is preferable, and is a group containing oxygen and sulfur. Is more preferable.

  The component (A) used in the present invention is preferably a bisphenol compound represented by the following general formula (4).

一般式（４）において、Ｒ^１２、Ｒ^１３、Ｒ^１４及びＲ^１５は、それぞれ個別に炭素数１〜４のアルキル基を示し、Ｒ^１６、Ｒ^１７、Ｒ^１８及びＲ^１９は、それぞれ個別に炭素数１〜１０のアルキレン基を示す。

In the general formula (4), R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are each individually An alkylene group having 1 to 10 carbon atoms is shown.

The alkyl group represented by R ^{12 to} R ¹⁵ may be linear or branched, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a tert-butyl group, etc. can be mentioned. Among these, a tert-butyl group is preferable from the viewpoint of excellent tar-like substance suppressing effect.

The alkylene group represented by R ^{5 to} R ⁸ may be linear or branched, and specific examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, and a heptylene. Group, octylene group, nonylene group, decylene group and other alkylene groups (these alkylene groups may be linear or branched). Among these, a methylene group and an ethylene group (dimethylene group, methylmethylene group) are preferable.

  Preferable specific examples of the component (A) used in the present invention include compounds represented by the following formula (5).

  When the electric discharge machining oil composition of the present invention contains the component (A), the content thereof is arbitrary, but is preferably 0.05% by mass or more, more preferably 0.1%, based on the total amount of the composition. It is at least mass%. When the content of the component (A) is less than 0.005% by mass, the effect of suppressing the formation of tar-like substances during electric discharge machining tends to be insufficient. On the other hand, the content of the component (A) is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the composition. When the content of the component (A) exceeds 10% by mass, electrode wear tends to increase.

Effect of addition of component (A) During electric discharge machining, since electric discharge is instantaneously performed using electric discharge machining oil as a medium, electric discharge machining oil is locally exposed to high temperature, and a part thereof is thermally decomposed. Thermal decomposition products may be polycondensed to produce tar-like substances.
When electric discharge machining is performed using an electric discharge machining oil containing such a tar-like substance, the tar-like substance adheres to the electrode and the workpiece (work), causing electric discharge concentration, and as a result, locally on the machining surface. Phenomena that cause unevenness are likely to occur.
Therefore, in order to further improve the surface state of the processed surface, it is necessary to sufficiently suppress the generation of tar-like substances.
In addition, although there is a method using a filter as a method of removing the tar-like substance from the electric discharge machining oil, since the tar-like substance generated in such a system usually contains fine particles having a particle diameter of 1 μm or less, The required characteristics of the filter are very strict, and more complicated equipment and complicated work are required.
Said (A) component has an effect which suppresses the production | generation of a tar-like substance fully.

Further, in the present invention, as an additive, a polymer substance having a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and a kinematic viscosity at 100 ° C. of 10 mm ² / s and / or a polymer having a weight average molecular weight of 500 or more. Substances can be added.
Examples thereof include high-viscosity oils, polymers (polymers), and resins having such properties. Examples of the high molecular weight material having the kinematic viscosity include mineral oil from which the kerosene fraction and normal paraffin content are excluded from the base oil described above. Specifically, for example, a lubricating oil fraction obtained by distillation of paraffinic or naphthenic crude oil is subjected to solvent removal, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing , And those obtained by appropriately combining one or more purification treatments such as white clay treatment.

  Examples of the polymer (polymer) include poly-α-olefins (for example, polybutene, polyisobutylene, etc.) or hydrides thereof, polyamide compounds, polyalkylstyrene, polyvinyl acetate, polyalkyl (meth) acrylate, and ethylene-propylene. Mention may be made of copolymers or their hydrides and styrene-maleic anhydride copolymers.

  Examples of the resin include terpene resin and petroleum resin. Examples of the terpene resin include monoterpenes such as hemiterpene and dipentene, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, tetraterpenes, polymers of polyterpenes, hydrides thereof, and modified resins thereof. Examples of petroleum resins include, for example, resins made from hydrocarbon fractions having 4 or 5 carbon atoms, hydrocarbon fractions having 9 or 10 carbon atoms, or fractions of petroleum cracked fractions. Examples thereof include resins used as mixed raw materials, modified resins thereof, cyclopentadiene-dicyclopentadiene copolymerized petroleum resins, hydrides thereof, or modified resins thereof.

  As the polymer component of the present invention, the processing accuracy and processing speed can be further increased, and an excellent effect of improving workability due to stickiness can be obtained in a balanced manner. It is preferably a poly-α-olefin (for example, polybutene, polyisobutylene, etc.), ethylene-propylene copolymer, polymethacrylate, or a hydride thereof, and polybutene or a hydride thereof is more preferable. . In addition, polybutene or a hydride thereof is preferable from the viewpoint that stains hardly occur.

The polymer substance as an additive component used in the present invention has a kinematic viscosity at 40 ° C. of preferably 100 mm ² / s or more, more preferably 500 mm ² / s or more, in order to further improve processing accuracy and processing speed. Preferably, it has 1000 mm ² / s or more, most preferably 5000 mm ² / s or more, and the kinematic viscosity at 100 ° C. is preferably 100 mm ² / s or more, more preferably 500 mm ² / s or more, most preferably 1000 mm. ² / s or more. On the other hand, the upper limit of the kinematic viscosity at 40 ° C. and 100 ° C. is not particularly limited, but the kinematic viscosity at 40 ° C. is usually 250,000 mm ² / s or less, and preferably does not cause deterioration of the working environment such as stickiness. It is 200000 mm < ² > / s or less, More preferably, it is 180000 mm < ² > / s or less. For the same reason, the kinematic viscosity at 100 ° C. is not more than 10000 mm ² / s, preferably not more than 7000 mm ² / s, more preferably not more than 5000 mm ² / s.

  In the present invention, the polymer substance as the additive component has a weight average molecular weight of preferably 1000 or more, more preferably 2000 or more, and further preferably 3000 or more in order to obtain further excellent processing accuracy and processing speed. , Most preferably those having 5000 or more. On the other hand, the upper limit of the weight average molecular weight is not particularly limited, but is usually 50000 or less, preferably 40000 or less, more preferably 30000 or less, and most preferably 10,000 or less.

  The content of the polymer substance as an additive component used in the present invention is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and still more preferably 0.5%, based on the total amount of the composition. % By mass or more, most preferably 1% by mass or more. On the other hand, the content is preferably 30% by mass or less, more preferably 20% by mass or less, and most preferably 15% by mass or less, based on the total amount of the composition. When the content as an additive component is less than 0.1% by mass based on the total amount of the composition, it is difficult to obtain a sufficient processing speed and good processing accuracy, while the content is the total amount of the composition When it exceeds 30% by mass on the basis, workability such as stickiness is deteriorated, and generation of tar-like substances tends to increase, which is not preferable.

Effect of addition of polymer substance The polymer substance as an additive component can improve the processing speed.
In addition, the specific polymer material as the additive component can be used in combination with the component (A) to suppress the generation of tar-like material and achieve a high-level surface condition and processing speed. In addition, the surface state of the processed surface can be maintained at a high level even when the service period is long.

Preferred examples of the polymer material as the additive component include the following.
(B) High molecular compound having a main chain composed of a hydrocarbon skeleton and an ester group bonded to a part of carbon atoms constituting the main chain (C) Polybutene having a weight average molecular weight of 650 to 1200 (D) Containing butylene oxide Polyalkylene glycol included as a unit

  Further, the electric discharge machining oil composition of the present invention comprises (B) a polymer compound having a main chain composed of a hydrocarbon skeleton and an ester group bonded to a part of carbon atoms constituting the main chain (hereinafter referred to as ( B) component)).

  In addition, the side chain of the high molecular compound which is (B) component may have a side chain group other than the said ester group. Such a side chain group is preferably a hydrocarbon group such as an alkyl group, a cycloalkyl group, an alkenyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, an arylalkyl group, and more preferably an alkyl group. As an alkyl group, a C1-C30 alkyl group is preferable, a C1-C20 alkyl group is more preferable, and a C2-C6 alkyl group is still more preferable. The alkyl group as the side chain group may be linear or branched.

  As the component (B) used in the present invention, for example, a homopolymer of a monomer represented by the following general formula (1) (maleic ester polymer, fumaric ester polymer, etc.), or the following general formula Examples include copolymers of the monomer represented by (1) and other monomers, and among these, the monomer represented by the following general formula (1) and the general formula (2) Copolymers with monomers are preferred.

［式（１）中、Ｒ^１は炭化水素基を示し、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ個別に水素原子、炭化水素基又はエステル基を示す。］

[In formula (1), R ¹ represents a hydrocarbon group, and R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a hydrocarbon group or an ester group. ]

［式（２）中、Ｒ^５、Ｒ^６、Ｒ^７及びＲ^８はそれぞれ個別に水素原子又はアルキル基を示す。］
上記一般式（１）中、Ｒ^１で示される炭化水素基としては、具体的には、アルキル基、シクロアルキル基、アルケニル基、アルキルシクロアルキル基、アリール基、アルキルアリール基、アリールアルキル基等が挙げられ、アルキル基が特に好ましい。

[In the formula (2), R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group. ]
Specific examples of the hydrocarbon group represented by R ¹ in the general formula (1) include an alkyl group, a cycloalkyl group, an alkenyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, and an arylalkyl group. And an alkyl group is particularly preferable.

Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group. Group, hexadecyl group, heptadecyl group, octadecyl group and the like. These alkyl groups may be linear or branched. When R ¹ is an alkyl group, the number of carbon atoms is preferably 1 or more, more preferably 2 or more, and still more preferably 3 or more from the viewpoint of processability. From the viewpoint of stability, the carbon number of the alkyl group is preferably 30 or less, more preferably 20 or less, and even more preferably 6 or less.

In the general formula (1), R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a hydrocarbon group or an ester group (—COOR; R represents a hydrocarbon group). R ^{2, R} 3, the hydrocarbon group ^{R 4} is a hydrocarbon group, and the hydrocarbon groups R when ^R 2, ^{R 3} and ^{R 4} is an ester group, respectively an alkyl group, a cycloalkyl Group, alkenyl group, alkylcycloalkyl group, aryl group, alkylaryl group, arylalkyl group and the like, and the alkyl group exemplified in the description of R ¹ is preferable.

As the monomer represented by the general formula (1), R ² , R ^3, or R ⁴ can be used because the workability and storage stability of the electric discharge machining oil composition can be compatible at a higher level. A monomer in which at least one is an ester group is preferable, and a monomer in which one of R ² , R ³ or R ⁴ is an ester group and the other two are hydrogen atoms or hydrocarbon groups is more preferable, Maleate esters and / or fumarate esters are particularly preferred.

In addition, when the high molecular compound concerning this invention contains the monomer represented by General formula (1), if the structure of the copolymer finally obtained is the same, the manufacturing method will not be restrict | limited. For example, when the polymer compound is a copolymer of a monomer represented by the general formula (1) and a monomer represented by the general formula (2), the polymer compound is represented by the general formula (1). The monomer and the monomer represented by the general formula (2) may be copolymerized, or may be represented by the following general formula (3) instead of the monomer represented by the general formula (1). After the copolymerization using the monomer, the carboxylic acid group (—COOH) derived from the monomer represented by the general formula (3), or R ⁹ , R ¹⁰ or R ¹¹ is a carboxylic acid group. In some cases, the carboxylic acid group may be esterified. When the monomer represented by the general formula (1) has a plurality of ester groups, an acid anhydride having a corresponding structure is used instead of the monomer represented by the general formula (1). Then, the carboxylic acid group derived from the acid anhydride may be esterified.

［式（３）中、Ｒ^９、Ｒ^１０及びＲ^１１は同一でも異なってもよく、それぞれ水素原子、炭化水素基、カルボン酸基又はエステル基を示す。］
また、本発明においては、上記一般式（１）で表される単量体として、１種を単独で用いてもよく、あるいは構造が異なる２種以上を併用してもよい。

[In Formula (3), R ⁹ , R ¹⁰ and R ¹¹ may be the same or different and each represents a hydrogen atom, a hydrocarbon group, a carboxylic acid group or an ester group. ]
In the present invention, as the monomer represented by the general formula (1), one type may be used alone, or two or more types having different structures may be used in combination.

In the general formula (2), R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or an alkyl group.

Examples of the alkyl group represented by R ⁵ , R ⁶ , R ⁷ , and R ⁸ include the alkyl groups exemplified in the description of R ¹ above. Among them, an alkyl group having 1 to 30 carbon atoms is preferable, and 6 to 6 carbon atoms. A 20 alkyl group is more preferable, and an alkyl group having 8 to 12 carbon atoms is still more preferable.

As the monomer represented by the general formula (2), at least one of R ⁵ , R ⁶ , R ⁷ or R ⁸ is preferably an alkyl group, and one is an alkyl group. Is more preferable.

  The monomer represented by the general formula (2) is preferably an α-olefin having 6 to 20 carbon atoms, more preferably 10 to 14 carbon atoms.

  In the present invention, as the monomer represented by the general formula (2), one type may be used alone, or two or more types having different structures may be used in combination.

  In the copolymer of the monomer represented by the general formula (1) and the monomer represented by the general formula (2), the ratio of each monomer is not particularly limited. From the viewpoint that both processability and storage stability can be achieved at a higher level, the ratio of the monomer represented by the general formula (1) may be 10 to 90 mol% based on the total amount of the monomers. Preferably, it is 30 to 70 mol%, more preferably 40 to 60 mol%.

  The weight average molecular weight of the component (B) is not particularly limited, but it is 5000 or less from the viewpoint of improving the surface condition of the processed surface and maintaining the characteristics at a high level over a long period of time, and improving workability due to stickiness and the like. It is preferable that it is 3000 or less. From the viewpoint of improving the processing speed, the weight average molecular weight of the component (A) is preferably 800 or more, more preferably 900 or more, and further preferably 1000 or more.

  When a component having a weight average molecular weight satisfying the above conditions is used as the component (B), the type and degree of polymerization of the monomer may be selected and adjusted to a desired weight average molecular weight. Moreover, you may use the commercial item (Ketjenlube115, Ketjenlube165 (all are made by Akzo Nobel) etc.) which is (B) component and a weight average molecular weight satisfy | fills the said conditions as it is. Further, from a polymer compound obtained by an arbitrary method or a commercially available polymer compound (including a mixture), a component corresponding to the component (B) and having a weight average molecular weight satisfying the above conditions, It may be separated by distillation or chromatography.

  Although content of (B) component in the electric discharge machining oil composition of this invention is arbitrary, it is 0.1-20 mass% normally on the basis of composition whole quantity. The content of the component (B) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, more preferably 0.5% by mass based on the total amount of the composition in terms of the processing speed and the surface state of the processed surface. % Or more is more preferable, and 1 mass% or more is particularly preferable. It also provides higher storage stability, suppresses the formation of tar-like substances, improves the surface condition of the machined surface, maintains its properties at a high level for a long period of time, and has workability such as stickiness. From the viewpoint of improvement, the content of the component (B) is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less, based on the total amount of the composition.

  In addition, the electric discharge machining oil composition of the present invention may contain (C) polybutene having a weight average molecular weight of 650 to 1200 (hereinafter sometimes referred to as “compound (C)”). The polybutene here refers to a polymer of 1-butene, 2-butene, isobutene and a mixture thereof and a hydride thereof.

  The weight average molecular weight of the compound (C) may be 1200 or less from the viewpoint of improving the surface condition of the processed surface and maintaining its characteristics at a high level over a long period of time, and improving workability due to stickiness and the like. It is necessary, 1000 or less is preferable, and 800 or less is more preferable. Further, from the viewpoint of improving the processing speed, the weight average molecular weight of the compound (C) needs to be 650 or more, preferably 700 or more, and more preferably 750 or more.

  Although content of the compound (C) used by this invention is arbitrary, it is 0.1-20 mass% normally on the basis of composition whole quantity. The content of the compound (C) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and more preferably 0.5% by mass based on the total amount of the composition in terms of the processing speed and the surface state of the processed surface. % Or more is more preferable, and 1 mass% or more is particularly preferable. In addition, the amount of 20% by mass or less is 20% by mass or less from the viewpoint of suppressing the generation of tar-like substances, improving the surface condition of the processed surface and maintaining the characteristics at a high level for a long period of time, and improving workability such as stickiness. Preferably, 15 mass% or less is more preferable, and 10 mass% or less is further more preferable.

  In addition, the electric discharge machining oil composition of the present invention can contain (D) polyalkylene glycol (hereinafter, sometimes referred to as component (D)) containing butylene oxide as a structural unit. Here, the butylene oxide referred to in the present invention includes both 1,2-epoxybutane (α-butylene oxide) and 2,3-epoxybutane (β-butylene oxide).

  The polyalkylene glycol as the component (D) may be a homopolymer of butylene oxide or a copolymer of butylene oxide and another alkylene oxide, or may be a mixture of two or more of these. .

  When component (D) is a copolymer of butylene oxide and another alkylene oxide, there is no particular limitation on the polymerization mode of the polyoxyalkylene chain, and either a random copolymer or a block copolymer may be used. . The alkylene oxide to be combined with butylene oxide is preferably an alkylene oxide having 2, 3, 5 or 6 carbon atoms, more preferably an alkylene oxide having 2 or 3 carbon atoms from the viewpoint of processability. Specific examples of the alkylene oxide having 2, 3, 5 or 6 carbon atoms include ethylene oxide, propylene oxide, 1,2-epoxy-1-methylpropane, 1,2-epoxyheptane, 1 , 2-epoxyhexane and the like.

  Further, when the component (D) is a copolymer of butylene oxide and another alkylene oxide, the proportion of butylene oxide is preferably 30 mol% or more based on the total amount of alkylene oxide as a raw material monomer, It is more preferably 50 mol% or more, further preferably 70 mol% or more, and particularly preferably 90 mol% or more. When the proportion of butylene oxide is less than the lower limit, processability and solubility in base oil tend to decrease.

  As described above, in the present invention, either a homopolymer of butylene oxide or a copolymer of butylene oxide and another alkylene oxide may be used as the component (D). From the viewpoint of solubility, it is preferable to use a homopolymer of butylene oxide.

  The polyalkylene glycol as component (D) is a diol type polyalkylene glycol in which both ends of the polyoxyalkylene chain are hydroxyl groups, a monoether type polyalkylene glycol in which one of the terminal hydroxyl groups is etherified with an alkyl group or the like, Alternatively, either a monoether type polyalkylene glycol in which both terminal hydroxyl groups are etherified with an alkyl group or the like may be used, but a diol type polyalkylene glycol is preferable.

  The weight average molecular weight of the component (D) is not particularly limited, but it is 5000 or less from the viewpoint of improving the surface condition of the processed surface and maintaining the characteristics at a high level for a long period of time, and improving workability due to stickiness and the like. Preferably, it is 3000 or less, more preferably 2000 or less. From the viewpoint of improving the processing speed, the weight average molecular weight of the component (A) is preferably 800 or more, more preferably 900 or more, and further preferably 1000 or more.

  (D) When using the component whose number average molecular weight satisfies the above conditions, when polymerizing the alkylene oxide, the type and degree of polymerization of the alkylene oxide are selected in advance and adjusted so as to have a desired weight average molecular weight. May be. In addition, a component containing butylene oxide as a constituent unit and a weight average molecular weight satisfying the above conditions from a polyalkylene glycol obtained by an arbitrary method or a commercially available polyalkylene glycol (including a mixture) by distillation or chromatography. It may be separated.

  Although content of (D) component in the electric discharge machining oil composition of this invention is arbitrary, it is 0.1-20 mass% normally on the basis of composition whole quantity. The content of the component (D) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and 0.5% by mass based on the total amount of the composition in terms of the processing speed and the surface state of the processed surface. % Or more is more preferable, and 1 mass% or more is particularly preferable. It also provides higher storage stability, suppresses the formation of tar-like substances, improves the surface condition of the machined surface, maintains its properties at a high level for a long period of time, and has workability such as stickiness. From the viewpoint of improvement, the content of the component (D) is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less, based on the total amount of the composition.

  The electric discharge machining oil composition of the present invention may further contain other additives as necessary for the purpose of further enhancing the performance as the electric discharge machining oil composition.

  Specific examples of such additives include antioxidants, antifoaming agents, rust inhibitors, metal deactivators, oiliness agents, extreme pressure agents, detergent dispersants, and surfactants. The content of these additives is usually 0.005 to 10% by mass based on the total amount of the electric discharge machining oil composition.

Kinematic viscosity at 40 ° C. EDM oil composition of the present invention, from the viewpoint of safety against fires, 0.5 mm ² / s or more der is, it is good Mashiku is ^{1 mm} 2 / s or more, 1. More preferably, it is 5 mm ² / s or more. On the other hand, removal of machining debris, maintaining a good cooling action for electrodes, etc., furthermore, removal of machining debris is easy, the surface condition of the machined surface is good, and the cooling action for electrodes etc. is good , and to obtain better effects, such as processing speed is improved, kinematic viscosity at 40 ° C. of the base oil, 9 ^mm 2 / s or less, the good Mashiku ^{5 mm} 2 / s or less, even more preferably 3mm ² / s or less.

  According to the electric discharge machining oil composition of the present invention having the above configuration, it becomes possible to achieve both high workability and storage stability at the time of electric discharge machining. Here, electrical discharge machining is performed by causing a tool electrode and a workpiece to face each other in an electrical discharge machining fluid such as oil or water, and generating a pulse current having a high repetition rate between two electrodes. As the discharge current and current pulse width increase, the processing speed increases. On the other hand, the processing surface becomes rough (such processing is referred to as “rough processing”). On the other hand, by reducing the discharge current and the pulse width, the surface roughness of the processed surface can be finished to be, for example, 5 μm or less in terms of Rz (such processing is referred to as “finishing processing”). The electric discharge machining oil composition of the present invention can be suitably used in both roughing and finishing, but is particularly suitable for finishing, and can increase the machining speed and improve the workability. It can be done.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.
In Examples and Comparative Examples, electric discharge machining oil compositions were prepared using the base oils shown in Table 1 at the blending ratios shown in Table 2. The components used for the preparation of each electric discharge machining oil composition are as follows.
(1) Manufacturing method of base oil to be used (FT synthetic oil hydrorefined oil, wax hydrocracked oil, and base oil 1, 2, 6, 7, 8)
1) FT synthetic hydrocarbon oil made from natural gas as raw material (content of hydrocarbons with a boiling point of 150 ° C or higher: 82% by mass, content of hydrocarbons with a boiling point of 360 ° C or higher: 41% by mass) in a distillation column It was separated into a light fraction having a temperature of 150 ° C. or lower, an intermediate fraction having a boiling point of 150 to 360 ° C., and a heavy wax residue (FT wax: corresponding to a fraction having a boiling point of 360 ° C. or higher).
2) The middle distillate separated in 1) was a hydrorefining catalyst (Pt: 0.8% by mass with respect to the support, USY zeolite / silica alumina / alumina binder: weight ratio 3/57/40), under a hydrogen stream. The hydrorefining treatment was performed at a reaction temperature of 311 ° C., a hydrogen pressure of 3.0 MPa, LHSV: 2.0 h-1, and a hydrogen / oil ratio of 340 NL / L.
3) The hydrorefined oil obtained in 2) was fractionated by distillation into a 150 to 250 ° C. fraction (kerosene fraction 1) and a 250 to 360 ° C. fraction (light oil fraction 1).
4) The FT wax obtained in 1) was obtained by using a hydrogenolysis catalyst (Pt: 0.8% by mass with respect to the support, USY zeolite / silica alumina / alumina binder: weight ratio 3/57/40). Then, hydrogenolysis was performed at a reaction temperature of 326 ° C., a hydrogen pressure of 4.0 MPa, LHSV: 2.0 h−1, and a hydrogen / oil ratio of 680 NL / L.
5) The hydrocracked oil obtained in 4) was fractionated by distillation into a 150 to 250 ° C. fraction (kerosene fraction 2) and a 250 to 360 ° C. fraction (light oil fraction 2).
6) The hydrorefined oil obtained in 2) and the hydrocracked oil obtained in 4) were mixed, and a 200 to 260 ° C. fraction (base oil 1) was obtained by atmospheric distillation. Properties of the base oil 1 are shown in Table 1.
7) The light oil fractions 1 and 2 obtained in 3) and 5) were mixed at 51:49 (mass ratio) to obtain a dilute base oil 2. Properties of the base oil 2 are shown in Table 1.
8) The light oil fractions 1 and 2 obtained in 3) and 5) were mixed at 57:43 (mass ratio) to obtain a diluted base oil 6. Table 1 shows the properties of the base oil 6.
9) Kerosene fractions 1 and 2 obtained in 3) and 5) were mixed at 63:37 (mass ratio) to obtain base oil 7. The properties of the base oil 7 are shown in Table 1.
10) Kerosene fractions 1 and 2 obtained in 3) and 5) were mixed at 49:51 (mass ratio) to obtain base oil 8. Table 1 shows the properties of the base oil 8.
(Base oil 3-5)
1) The base oil 3 was a general hydrorefined mineral oil. Table 1 shows the properties of the base oil 3.
2) The base oil 4 was a general isoparaffin solvent. Table 1 shows the properties of the base oil 4.
3) As the base oil 5, a general normal paraffin solvent was used. Table 1 shows the properties of the base oil 5.

(2) Properties of base oil used in Examples Table 1 shows properties of base oils 1 to 8.

The following compound A and compound B were mixed with the base oil of Table 1 in the amounts shown in Table 2 to prepare an electric discharge machining oil.
Compound A: Thiobisphenol type compound of the following formula

 (Compound B): Polybutene hydride (weight average molecular weight: 2900)

  Using the obtained electric discharge machining oil composition, machining was performed under the following conditions using an electric discharge machine with servo (Diax EA12E, manufactured by Mitsubishi Electric Corporation), and the metal machining speed was evaluated by the evaluation method shown below.

The conditions for electric discharge machining are as follows.
Electrode: Copper square bar electrode (10mm x 10mm)
Current peak value (A): 1.0
Pulse width ON (μ sec): 2.0
Pause time OFF (μ sec): 8.0
Depth of electrode penetration (mm): 2
Processing time (minutes): 40

The machining fluid (electric discharge machining oil) was filled in a machining tank with 12 L of machining fluid and subjected to the following tests.
(Evaluation of processing speed)
The time required for machining (time until the electrode penetration depth reaches a predetermined position) and the weight change of the workpiece before and after machining were measured, and the machining speed was calculated using the following formula.
Machining speed (mg / min) = Change in weight of workpiece before and after machining (mg) / Time required for machining (min)
(Odor evaluation)
The odor of the processing tank when processed under the above conditions was determined. Evaluated by 10 people, did not care: 0 points, there is a little odor: 2 points, 4 points with odor, scored an average value. Less than 1 point was evaluated as ◯, 1 point or more and less than 2 points as Δ, and 2 points or more as ×.
The results are shown in Table 2.

Claims (1)

Hydrocarbon oil is produced by a production process having at least one process selected from a Fischer-Tropsch (FT) synthesis process, a hydrocracking process for wax-containing components, and a hydrotreating process for components obtained from these processes. a kerosene and gas oil fraction, density at 15 ℃ is 0.7~0.8g / cm ^3, n- paraffin content of 10 to 90 wt%, aromatic content 0 to 3% by volume, naphthene content is 0-20 volume An electrical discharge machining oil composition comprising a hydrocarbon oil having a kinematic viscosity at 40 ° C. of 0.5 to 9 mm 2 / s .