Metal processing oil composition

Abstract

To provide a metal processing oil composition having good processability and capable of improving hydrophilicity of a metal.SOLUTION: A metal processing oil composition comprises a base oil (A) and a polyoxyalkylene compound (B) having a repeated structure of oxyethylene groups and a repeated structure of oxypropylene groups, wherein the base oil (A) contains a branched chain hydrocarbon (A1) having a methyl group proton ratio of 20 or more and 65 or less when an integral value of all protons detected by 1H-NMR analysis is taken as 100.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a metalworking oil composition. [Background technology]

[0002] In the field of metalworking, metalworking oil compositions have been used to lubricate the machining sites of metal workpieces, and metalworking oil compositions are required to have excellent workability, such as the ability to suppress seizure between the workpiece and the tool.

[0003] Aluminum fins used in heat exchangers of refrigeration systems such as refrigerators and air conditioners are produced by subjecting aluminum fin materials to plastic working such as bulging, drawing, punching, curling, ironing, etc. The processing of aluminum fin materials is usually carried out using a metal working oil composition.

[0004] For example, Patent Document 1 discloses a hydrophilic treatment agent for aluminum fins of heat exchangers, which contains a hydrophilic polymer (A) and a crosslinking agent (B), wherein the solid mass ratio of hydrophilic polymer (A) / crosslinking agent (B) is within the range of 97 / 3 to 76 / 24, and the amount of hydrophilic polymer (A) is 91 to 100 parts by mass per 100 parts by mass of resin solids remaining after subtracting the crosslinking agent (B) from the resin solids of the hydrophilic treatment agent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-20015 Summary of the Invention [Problem to be solved by the invention]

[0006] A metal working oil composition used in the production of aluminum fins not only has excellent workability but also improves the cooling properties (heat dissipation efficiency) of the aluminum fins, and therefore it is preferable that the metal working oil composition can improve the hydrophilicity of the aluminum fins. Furthermore, with regard to the hydrophilicity of the aluminum fins, it is preferable that the hydrophilicity of the aluminum fins is high not only after the processed aluminum fins have been heated and dried, but also when the aluminum fins have been washed with water.

[0007] The hydrophilic treatment agent for aluminum fins of heat exchangers described in Patent Document 1 leaves room for improvement in terms of the hydrophilicity of the aluminum fins after the aluminum fins to which the hydrophilic treatment agent is attached are washed with water, and also leaves room for improvement in terms of processability.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal working oil composition that has good workability and can improve the hydrophilicity of metals. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following configuration. [1] A composition comprising a base oil (A) and a polyoxyalkylene compound (B) having a repeating structure of an oxyethylene group and a repeating structure of an oxypropylene group, wherein the base oil (A) is 1 A metalworking oil composition comprising a branched-chain hydrocarbon (A1) having a methyl group proton ratio of 20 to 65, where the integral value of all protons detected by H-NMR analysis is taken as 100. [2] The metal working oil composition according to [1], wherein the branched-chain hydrocarbons (A1) have a ratio (CB / CA) of the proportion of hydrocarbons with the highest carbon number (CA) to the proportion of hydrocarbons with the second highest carbon number (CB) in a carbon number distribution obtained by gas chromatography distillation of 0.4 or more. [3] The metal working oil composition according to [1] or [2], wherein the branched chain hydrocarbons (A1) have a carbon number distribution obtained by gas chromatography distillation in which the proportion (CC) of hydrocarbons having 10 or less carbon atoms is 20% by volume or more. [4] The metal working oil composition according to any one of [1] to [3], wherein the polyoxyalkylene compound (B) has an EO / PO molar ratio of 0.25 to 0.75. [5] The metal working oil composition according to any one of [1] to [4], wherein the polyoxyalkylene compound (B) has a number average molecular weight (Mn) of 450 or less. [6] The metal working oil composition according to any one of [1] to [5], wherein the proportion of the branched chain hydrocarbon (A1) in the base oil (A) is 30 mass % or more and 100 mass % or less. [7] The metalworking oil composition according to any one of [1] to [6], which is used in machining an aluminum fin. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a metalworking oil composition that has good workability and can improve the hydrophilicity of metals. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram showing an outline of a flat plate sliding test. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Metalworking oil composition) The metal working oil composition of this embodiment contains a base oil (A) and a polyoxyalkylene compound (B) having a repeating structure of an oxyethylene group and a repeating structure of an oxypropylene group.

[0013] The metal working oil composition of this embodiment has a kinematic viscosity at 40°C of 5mm 2 / s or less is preferable, and 3 mm 2 / s or less is more preferable, and 2 mm 2 / s or less is even more preferable. In this specification, the kinematic viscosity at 40°C means a value measured in accordance with JIS K2283:2000.

[0014] <Base oil (A)> The base oil (A) has a kinematic viscosity of 5mm at 40°C. 2 / s or less is preferable, and 3 mm 2 / s or less is more preferable, and 2 mm 2 / s or less is even more preferable.

[0015] The base oil (A) is 1 It contains a branched-chain hydrocarbon (A1) (hereinafter also referred to as "component (A1)") in which the ratio of methyl group protons is 20 to 65, when the integral value of all protons detected by H-NMR analysis is set to 100.

[0016] As the component (A1), mineral oil, GTL (Gas to Liquids), CTL (Coal to Liquids), etc. are used. As the mineral oil, a distillate obtained by atmospheric distillation of crude oil can be used. In addition, a lubricating oil fraction obtained by further vacuum distillation of the distillate obtained by the atmospheric distillation and then refining the distillate through various refining processes can also be used. The refining process may be a suitable combination of hydrorefining, solvent extraction, solvent dewaxing, hydrodewaxing, sulfuric acid washing, clay treatment, etc. Mineral oil can be obtained by combining these refining processes in a suitable order. Furthermore, a mixture of a plurality of refined oils with different properties obtained by subjecting different crude oils or distillate oils to a combination of different refining processes may also be used. GTL is a hydrocarbon that is synthesized using natural gas as a raw material using the Fischer-Tropsch process (FT process). CTL is a hydrocarbon synthesized using coal as a raw material by the FT method. A mixture of these may also be used as the component (A1).

[0017] The component (A1) is1 It is a branched hydrocarbon in which the ratio of methyl group protons is 20 to 65, when the integral value of all protons detected by H-NMR analysis is taken as 100. In other words, component (A1) is an isoparaffin with relatively few branches.

[0018] The component (A1) has a proton ratio of the methyl group of 65 or less, preferably 60 or less, more preferably 50 or less, and even more preferably 45 or less. On the other hand, the proton ratio of the methyl group in the component (A1) is preferably 20 or more, and more preferably 25 or more.

[0019] When the proton ratio of the methyl group in component (A1) is less than 20, i.e., when the base oil has fewer branches, it is presumed that the molecules of the base oil are densely stacked, making it difficult for the polyoxyalkylene compound (B), described below, to be adsorbed to the surface of the metal being processed. On the other hand, when the proton ratio of the methyl group in component (A1) is more than 65, i.e., when the base oil has more branches, it is presumed that the gaps between the molecules of the base oil are small, making it difficult for the polyoxyalkylene compound (B), described below, to be adsorbed to the surface of the metal being processed. When the proton ratio of the methyl group in component (A1) is within the above-mentioned preferred range, i.e., when the branching of the base oil is appropriate, it is presumed that the molecules of the base oil become irregular, increasing the gaps between the molecules of the base oil, and making it easier for the polyoxyalkylene compound (B), described below, to be adsorbed onto the surface of the metal being processed.

[0020] For example, the proton ratio of the methyl group in the component (A1) is preferably 25 or more and 60 or less, more preferably 25 or more and 50 or less, and even more preferably 25 or more and 45 or less.

[0021] 1 The measurement equipment and conditions for H-NMR measurement are as follows: Equipment used: Bruker AVANCE III HD-cryo600 NMR 1H resonance frequency: 600.18MHz Solvent: CDCl3 Concentration: Approximately 50mg / mL Measurement method: 1 H Non-decoupling method Pulse width: 30° pulse Waiting time: 5 seconds Chemical shift standard: CHCl3 (7.28 ppm) in CDCl3

[0022] When component (A1) is a mineral oil, the proton ratio of the methyl group in component (A1) can be controlled by selecting the crude oil and by appropriately managing the refining conditions (temperature, pressure, catalyst, etc.) in refining such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment of the fraction obtained by atmospheric distillation and / or reduced pressure distillation of the crude oil. When the component (A1) is GTL or CTL, the proton ratio of the methyl group in the component (A1) can be controlled by appropriately managing the reaction conditions (temperature, pressure, catalyst, etc.) of the FT reaction.

[0023] The component (A1) is preferably a branched chain hydrocarbon having 6 to 20 carbon atoms, and more preferably a branched chain hydrocarbon having 6 to 18 carbon atoms. Furthermore, the component (A1) is preferably a mixture of hydrocarbons with different carbon numbers. The carbon number of the hydrocarbon in the present invention means the carbon number obtained by gas chromatographic distillation, which will be described later.

[0024] In the carbon number distribution of component (A1), the volume ratio (CB / CA) of the proportion (volume %) of hydrocarbons with the highest carbon number (CA) to the proportion (volume %) of hydrocarbons with the second highest carbon number (CB) is preferably 0.4 or more, and more preferably 0.45 or more.

[0025] In the carbon number distribution of the component (A1), the proportion of hydrocarbons having 10 or less carbon atoms (CC) is preferably 20% by volume or more, and more preferably 25% by volume or more. The proportion of hydrocarbons having 10 or less carbon atoms (CC) is preferably 60% by volume or less, and more preferably 50% by volume or less.

[0026] The carbon number distribution in component (A1) can be controlled by distilling the mineral oil, GTL, or CTL while precisely adjusting the pressure, temperature, reflux ratio, or number of plates in the distillation column when producing the mineral oil, GTL, or CTL.

[0027] [Carbon number distribution measurement] The measurement conditions for gas chromatographic distillation are as follows. Model: Shimadzu GC-2030 Column: UA-1 MS / HT (30m×0.25mmI.D.×0.10μm) Carrier gas: Helium 200kPa Detector: FID Det.Temp.:350℃ Oven Temp.: 50℃ (2 min) ~ 170℃ Temp. Rate: 6℃ / min Inj.Vol: 1 μL toluene solution

[0028] The initial boiling point of component (A1) is preferably 120°C or higher, more preferably 130°C or higher, and even more preferably 150°C or higher.

[0029] The end point of the component (A1) is preferably 300°C or lower, more preferably 280°C or lower, and even more preferably 250°C or lower.

[0030] In this specification, the initial boiling point and end point of the component (A1) refer to values ​​measured by the atmospheric pressure method specified in JIS K2254:2018.

[0031] By ensuring that the initial boiling point of component (A1) is equal to or greater than the above-mentioned preferred value, volatilization at room temperature can be more sufficiently prevented, and processability can be further improved.

[0032] By ensuring that the end point of component (A1) is equal to or less than the above preferred value, processability is further improved.

[0033] The difference between the end point and the initial boiling point of component (A1) (end point - initial boiling point) is preferably 10°C or more, more preferably 15°C or more, and even more preferably 20°C or more.

[0034] When the difference between the final boiling point and the initial boiling point of component (A1) is equal to or greater than the above-mentioned preferred value, that is, the greater the amount of hydrocarbons with different carbon numbers, the more improved the processability.

[0035] In one embodiment, the component (A1) is 1 When the integral value of all protons detected by H-NMR analysis is taken as 100, the ratio of methyl group protons is 65 or less, preferably 60 or less, more preferably 50 or less, and even more preferably 45 or less; 1 the ratio of methyl group protons is 15 or more, preferably 20 or more, and more preferably 25 or more, when the integral value of all protons detected by H-NMR analysis is taken as 100; In the carbon number distribution obtained by gas chromatographic distillation, the volume ratio (CB / CA) of the proportion (CA) (volume %) of hydrocarbons having the highest carbon number to the proportion (CB) (volume %) of hydrocarbons having the second highest carbon number is preferably 0.4 or more, more preferably 0.45 or more; A mixture of branched chain hydrocarbons having 6 to 20 carbon atoms is preferred, and a mixture of branched chain hydrocarbons having 6 to 18 carbon atoms is more preferred. Furthermore, from the viewpoint of further improving processability, the initial boiling point of the (A1) component is preferably 120°C or higher, more preferably 130°C or higher, and even more preferably 150°C or higher. The end point is preferably 300°C or less, more preferably 280°C or less, and even more preferably 250°C or less. The difference between the end point and the initial boiling point (end point - initial boiling point) is preferably 10°C or more, more preferably 15°C or more, and even more preferably 20°C or more.

[0036] Component (A1) has a kinematic viscosity of 5mm at 40°C. 2 / s or less is preferable, and 3 mm 2 / s or less is more preferable, and 2 mm 2 / s or less is even more preferable.

[0037] The proportion of the (A1) component in the base oil (A) is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, and especially more preferably 98% by mass or more. In the metal working oil composition of this embodiment, the base oil (A) most preferably consists of only the component (A1).

[0038] <Polyoxyalkylene compound (B)> The polyoxyalkylene compound (B) (hereinafter also referred to as "component (B)") in the metal working oil composition of this embodiment has a repeating structure of an oxyethylene group and a repeating structure of an oxypropylene group.

[0039] Component (B) may be a block copolymer having an oxyethylene group block (OE block) with long succession of oxyethylene groups (OE) and an oxypropylene group block (OP block) with long succession of oxypropylene groups (OP), or it may be a random copolymer in which the arrangement of OE and OP is disordered.

[0040] The proportion of oxyethylene groups in the entire component (B) is preferably 35 to 95 mol%, more preferably 45 to 85 mol%, and even more preferably 55 to 75 mol%, relative to the total amount (100 mol%) of oxyalkylene groups in the component (B). If the proportion of OE in the entire component is equal to or greater than the lower limit of the above range, hydrophilicity is further ensured, while if it is equal to or less than the upper limit of the above range, oil solubility is more likely to be improved.

[0041] The proportion of oxypropylene groups in the entire component (B) is preferably 5 to 65 mol%, more preferably 15 to 55 mol%, and even more preferably 25 to 45 mol%, relative to the total amount (100 mol%) of oxyalkylene groups in the component (B). If the proportion of OP in the entire component is at least the lower limit of the above range, oil solubility is further ensured, while if it is at most the upper limit of the above range, hydrophilicity is more likely to be improved.

[0042] When the oxyalkylene groups in the polyoxyalkylene compound consist solely of oxypropylene groups and oxyethylene groups, the EO / PO molar ratio is preferably 0.5 to 20, more preferably 0.8 to 6, and even more preferably 1.0 to 3.0.

[0043] The number average molecular weight (Mn) of the polyoxyalkylene compound is preferably 200 to 350, more preferably 200 to 400, and even more preferably 200 to 450. When the Mn of the polyoxyalkylene compound is equal to or greater than the lower limit of the above range, hydrophilicity is imparted and the oil-solubility effect is sufficiently exhibited, whereas when the Mn is equal to or less than the upper limit of the above preferred range, oil solubility is more likely to be improved.

[0044] The structure of component (B) (oxyethylene group proportion, oxypropylene group proportion), number average molecular weight, and weight average molecular weight can be measured by the methods shown below.

[0045] [Structure of polyoxyalkylene compound] The structure of the polyoxyalkylene compound is 13 It can be analyzed by NMR measurement using C. NMR measurement conditions Measurement equipment: Agilent, product name "DD2" Magnet: 600MHz Nuclide: 13C Analytical methods: 1H inverse gated decoupling and DEPT135 Waiting time: 10 to 20 seconds Solvent: CDCl3

[0046] Oxyethylene group ratio The proportion of oxyethylene groups can be determined by calculating the proportion of oxyethylene groups relative to the total amount (100 mol%) of oxyalkylene groups contained in the polyoxyalkylene compound. The oxypropylene group (OP) can be quantified by [CH3 terminal derived from propylene oxide (PO) (integral value around 17 ppm) + CH derived from PO (integral value around 75 ppm)] / 2. Oxyethylene groups (OE) can be quantified by [sum of integral values ​​of all CH2 (downward-pointing peaks in the DEPT spectrum measured with DEPT135) - {CH3 terminal derived from PO (integral value around 17 ppm) + CH derived from PO (integral value around 75 ppm)} / 2] / 2. When the oxyalkylene groups in the polyoxyalkylene compound consist only of oxypropylene groups and oxyethylene groups, the proportion (mol %) of oxyethylene groups can be calculated by OE / (OE+OP)×100.

[0047] The proportion of oxypropylene groups bonded to the terminals of polyoxyalkylene compounds The proportion of oxypropylene groups bonded to the terminals of the polyoxyalkylene compound can be determined by calculating the proportion of oxypropylene groups bonded to the terminals relative to the total amount (100 mol%) of oxyalkylene groups bonded to the terminals.

[0048] The proportion of oxyethylene groups bonded to the terminals of polyoxyalkylene compounds The proportion of oxyethylene groups bonded to the terminals of a polyoxyalkylene compound can be determined by calculating the proportion of oxyethylene groups bonded to the terminals relative to the total amount (100 mol%) of oxyalkylene groups bonded to the terminals.

[0049] The oxypropylene group bonded to the terminal (OP terminal) can be quantified by the integral values ​​near 65 ppm and 67 ppm in the above NMR measurement. The oxyethylene group bonded to the terminal (OE terminal) can be quantified by the integrated value around 61 ppm in the above NMR measurement. When the oxyalkylene groups in a polyoxyalkylene compound consist only of oxypropylene groups and oxyethylene groups, the proportion (mol %) of oxypropylene groups bonded to the terminals can be calculated by OP terminals / (OE terminals + OP terminals) x 100. The proportion (mol %) of oxyethylene groups bonded to the terminals can be calculated by OE terminals / (OE terminals + OP terminals) x 100.

[0050] [Number average molecular weight, weight average molecular weight] The number average molecular weight and weight average molecular weight of the polyoxyalkylene compound can be measured by gel permeation chromatography (GPC). GPC measurement conditions Measurement device: Waters, product name "Alliance2695" Column: Tosoh Corporation, product name "TSK-GEL GMHHR-M" x 2 (7.8 mm I.D. x 30 cm) Detector: RI Measurement conditions: column temperature 25°C, developing solvent tetrahydrofuran, flow rate 1.0 mL / min Sample: 2.0% by mass tetrahydrofuran solution Injection volume: 100μL Standard sample: polystyrene

[0051] In the metal working oil composition of this embodiment, the component (B) may be used alone or in combination of two or more types.

[0052] The content of component (B) is preferably 0.05 mass % or more, more preferably 0.10 mass % or more, even more preferably 0.15 mass % or more, and particularly preferably 0.20 mass % or more, based on the total amount of the metal working oil composition of this embodiment. The content of component (B) is preferably 1.0 mass% or less, more preferably 0.8 mass% or less, and even more preferably 0.5 mass% or less, based on the total amount of the metal working oil composition of this embodiment. For example, the content of component (B) is preferably 0.05 mass% to 1.0 mass%, more preferably 0.10 mass% to 0.8 mass%, even more preferably 0.15 mass% to 0.5 mass%, and particularly preferably 0.20 mass% to 0.5 mass%, based on the total amount of the metal working oil composition of this embodiment. When the content of component (B) is equal to or greater than the above-mentioned preferable lower limit, the hydrophilicity of the processed metal can be further improved. If the content of component (B) is equal to or less than the above-mentioned preferable upper limit, the hydrophilicity of the processed metal can be sufficiently improved in proportion to the content.

[0053] <Optional ingredients> The metal working oil composition of the present embodiment may contain optional components other than the above-mentioned base oil (A) and component (B). Examples of optional components include an ester (C1) having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid (hereinafter also referred to as "component (C1)"), a monohydric alcohol (C2) (hereinafter also referred to as "component (C2)"), a dimer to tetramer (D) of propylene glycol (hereinafter also referred to as "component (D)"), a linear olefin (E) (hereinafter also referred to as "component (E)"), an extreme pressure additive, a rust inhibitor, a corrosion inhibitor, and an antifoaming agent.

[0054] <Component (C1): Ester having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid> The component (C1) is an ester having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid.

[0055] Monohydric alcohol The monohydric alcohol used as a raw material for the component (C1) may be a monohydric alcohol having 1 to 25 carbon atoms, and the monohydric alcohol may be linear or branched, and may be saturated or unsaturated. Specific examples of monohydric alcohols include methanol, ethanol, propanol, butanol, octanol (caprylic alcohol), nonanol, decanol (capric alcohol), undecanol, dodecanol (lauryl alcohol), tridecanol, tetradecanol (myristyl alcohol), pentadecanol, hexadecanol (cetyl alcohol), heptadecanol, octadecanol (stearyl alcohol), nonadecanol, eicosanol (arachidyl alcohol), heneicosanol, and docosanol (behenyl alcohol). linear saturated alcohols such as 2-ethylhexanol, isostearyl alcohol, and 2-n-octyl-1-dodecanol; branched saturated alcohols such as cis-9-hexadecen-1-ol (palmitoleyl alcohol), 9E-octadecen-1-ol (elaidyl alcohol), cis-9-octadecen-1-ol (oleyl alcohol), and 9Z,12Z-octadecadien-1-ol (linoleyl alcohol).

[0056] Monobasic acid Examples of monobasic acids used as raw materials for the component (C1) include fatty acids, specifically fatty acids having 1 to 25 carbon atoms, and the fatty acids may be linear or branched, and may be saturated or unsaturated. Of the above fatty acids, fatty acids having 6 to 24 carbon atoms are preferred.

[0057] Specific preferred examples include linear saturated fatty acids such as n-hexanoic acid, n-heptanoic acid, n-octanoic acid (caprylic acid), n-nonanoic acid, n-decanoic acid (capric acid), n-undecanoic acid, n-dodecanoic acid (lauric acid), n-tridecanoic acid, n-tetradecanoic acid (myristic acid), n-pentadecanoic acid, n-hexadecanoic acid (palmitic acid), n-heptadecanoic acid, n-octadecanoic acid (stearic acid), n-icosanoic acid (arachidic acid), docosanoic acid (behenic acid), and tetracosanoic acid (lignoceric acid); isoheptanoic acid, isooctanoic acid, iso-octanoic acid, and iso-octadecanoic acid. Examples of branched-chain saturated fatty acids include nonanoic acid, isodecanoic acid, isoundecanoic acid, isododecanoic acid, isotridecanoic acid, isotetradecanoic acid, isopentadecanoic acid, isohexadecanoic acid, isoheptadecanoic acid, isooctadecanoic acid, and isoicosanoic acid; unsaturated fatty acids include 9-tetradecenoic acid (myristoleic acid), 9-hexadecenoic acid (palmitoleic acid), 9-octadecenoic acid (oleic acid), eicosenoic acid, and linoleic acid (9,12-octadecadienoic acid); and naturally occurring fatty acids containing one or more of these fatty acids (for example, beef tallow and coconut oil).

[0058] Of the above, the (C1) component is preferably an ester (C11) having 13 to 22 carbon atoms obtained from a monohydric alcohol and a monobasic acid (hereinafter also referred to as the (C11) component). Specifically, the (C11) component is more preferably an ester having 13 to 22 carbon atoms obtained from a monovalent linear saturated alcohol and a linear saturated fatty acid, and more preferably methyl laurate, ethyl laurate, propyl laurate, butyl laurate, pentyl laurate, hexyl laurate, heptyl laurate, octyl laurate, nonyl laurate, decyl laurate, methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, pentyl palmitate, and hexyl palmitate, and particularly preferably methyl laurate, butyl palmitate, and butyl stearate.

[0059] The component (C1) in the metal working oil composition of this embodiment may use one type alone, or two or more types in combination.

[0060] The content of component (C1) in the metal working oil composition of this embodiment is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and even more preferably 0.3 mass % or more, based on the total amount of the metal working oil composition. On the other hand, the content of component (C1) is preferably 5.0 mass % or less, more preferably 3.0 mass % or less, and even more preferably 1.0 mass % or less, based on the total amount of the metal working oil composition.

[0061] When the content of component (C1) is equal to or greater than the above-mentioned preferable lower limit, processability is further improved, and when the content of component (C) is equal to or less than the above-mentioned preferable upper limit, drying properties are further improved.

[0062] For example, the content of component (C1) is preferably 0.1 mass % or more and 5.0 mass % or less, more preferably 0.2 mass % or more and 3.0 mass % or less, and even more preferably 0.3 mass % or more and 1.0 mass % or less, based on the total amount of the metal working oil composition.

[0063] <Component (C2): Monohydric alcohol> The component (C2) is a monohydric alcohol, and examples thereof include the same monohydric alcohols as those used as raw materials for the component (C1) described above. Of these, the (C2) component is preferably a monohydric alcohol (C21) having 10 to 16 carbon atoms (hereinafter also referred to as the (C21) component), more preferably a monohydric alcohol having 12 or 14 carbon atoms, and even more preferably dodecanol (lauryl alcohol).

[0064] The component (C2) in the metal working oil composition of this embodiment may use one type alone, or two or more types in combination.

[0065] The content of component (C2) in the metal working oil composition of this embodiment is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and even more preferably 0.3 mass % or more, based on the total amount of the metal working oil composition. On the other hand, the content of component (C2) is preferably 5.0 mass % or less, more preferably 3.0 mass % or less, and even more preferably 1.0 mass % or less, based on the total amount of the metal working oil composition.

[0066] When the content of component (C2) is equal to or greater than the above-mentioned preferable lower limit, the processability is further improved, and when the content of component (C) is equal to or less than the above-mentioned preferable upper limit, the drying property is further improved.

[0067] For example, the content of component (C2) is preferably 0.1 mass % or more and 5.0 mass % or less, more preferably 0.2 mass % or more and 3.0 mass % or less, and even more preferably 0.3 mass % or more and 1.0 mass % or less, based on the total amount of the metal working oil composition.

[0068] <Component (D): Propylene glycol dimer to tetramer> Specifically, the component (D) is preferably one or more compounds selected from the group consisting of dipropylene glycol, tripropylene glycol, and tetrapropylene glycol, with tripropylene glycol being more preferred. As the component (D), the above compounds may be used alone or as a mixture of two or more.

[0069] The content of component (D) in the metal working oil composition of this embodiment is preferably 0.05 mass % or more, more preferably 0.08 mass % or more, and even more preferably 0.1 mass % or more, based on the total amount of the metal working oil composition. On the other hand, the content of component (D) is preferably 2.0 mass % or less, more preferably 1.5 mass % or less, and even more preferably 1.0 mass % or less, based on the total amount of the metal working oil composition.

[0070] When the content of component (D) is equal to or greater than the above-mentioned preferable lower limit, processability is further improved. When the content of component (D) is equal to or less than the above-mentioned preferable upper limit, the solubility of component (D) in base oil (A) is improved.

[0071] For example, the content of component (D) is preferably 0.05 mass % or more and 2.0 mass % or less, more preferably 0.08 mass % or more and 1.5 mass % or less, and even more preferably 0.1 mass % or more and 1.0 mass % or less, based on the total amount of the metal working oil composition.

[0072] <Component (E): Linear olefin> Examples of component (E) include linear olefins having 6 to 20 carbon atoms, and among these, linear olefins having 8 to 18 carbon atoms are preferred, and linear olefins having 10 to 16 carbon atoms are more preferred.

[0073] The linear olefin may have one double bond or two or more double bonds in the molecule, but preferably has one double bond. There are also no particular restrictions on the position of the double bond, but it is preferable that the double bond is at the terminal, i.e., that the olefin is an n-α-olefin, as this will result in the resulting metal working oil composition having better lubricity.

[0074] Specific examples of linear olefins include 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-icosene, and mixtures of two or more of these. Among these, 1-dodecene is preferred.

[0075] The linear olefin may be one obtained by various methods, for example, an ethylene oligomer obtained by polymerizing ethylene by a conventional method.

[0076] The linear olefins may be used alone or as a mixture of two or more kinds. The content of component (E) is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the metal working oil composition. The content of component (E) is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the metal working oil composition.

[0077] When the content of component (E) is equal to or greater than the above-mentioned preferable lower limit, processability is further improved. When the content of component (E) is equal to or less than the above-mentioned preferable upper limit, the solubility of component (E) in base oil (A) is improved.

[0078] For example, the content of component (E) is preferably 5% by mass or more and 30% by mass or less, more preferably 8% by mass or more and 25% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less, based on the total amount of the metal working oil composition.

[0079] Extreme pressure additives Specific examples of extreme pressure additives include phosphorus compounds such as tricresyl phosphate, and organometallic compounds such as zinc dialkyldithiophosphate.

[0080] <Rust inhibitor> Specific examples of the rust inhibitor include salts of fatty acids such as oleic acid, sulfonates such as dinonylnaphthalene sulfonate, partial esters of polyhydric alcohols such as sorbitan monooleate, amines and derivatives thereof, and phosphate esters and derivatives thereof.

[0081] <Corrosion inhibitor> Examples of corrosion inhibitors include benzotriazole.

[0082] The metal working oil composition of this embodiment exerts favorable effects when used in particular for the production of aluminum fins. That is, the metal working oil composition of this embodiment is preferably an aluminum working oil composition used for producing aluminum fins. [Example]

[0083] The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

[0084] <Preparation of base oil (A)> Base oils (A-1, A-2, and a-1) having the physical properties shown in Table 1 were prepared.

[0085] [Measurement of the proton ratio of methyl groups] Base oils 1 and 2 1 The proton ratios of the methyl group (CH), methylene group (CH), and methine group (CH) were measured, assuming that the integral value of all protons detected by H-NMR analysis was 100. The results are shown in Table 1.

[0086] 1 The measurement equipment and conditions for H-NMR measurement are as follows: Equipment used: Bruker AVANCE III HD-cryo600 NMR 1 H resonance frequency: 600.18MHz Solvent: CDCl3 Concentration: Approximately 50mg / mL Measurement method: 1 H Non-decoupling method Pulse width: 30° pulse Waiting time: 5 seconds Chemical shift standard: CHCl3 (7.28 ppm) in CDCl3

[0087] [Measurement of distillation properties] The initial boiling points and final boiling points of base oils 1 and 2 were measured according to the atmospheric pressure method of JIS K 2254. The initial boiling points (IBP), final boiling points (FBP), and the difference between the final boiling point and the initial boiling point (FBP-IBP) of base oils 1 and 2 are shown in Table 1.

[0088] [Carbon number distribution measurement] The carbon number distributions of base oils 1 and 2 were measured by gas chromatographic distillation. The measurement conditions for gas chromatographic distillation are as follows. Model: Shimadzu GC-2030 Column: UA-1 MS / HT (30m×0.25mmI.D.×0.10μm) Carrier gas: Helium 200kPa Detector: FID Det.Temp.:350℃ Oven Temp.: 50 (2 min) ~ 170℃ Temp. Rate: 6℃ / min Inj.Vol: 1 μL toluene solution

[0089] [Table 1]

[0090] <Preparation of Metalworking Oil Composition> (Examples 1 to 8, Comparative Examples 1 to 3) The components shown in Tables 2 and 3 were mixed to prepare metalworking oil compositions of the respective examples. In Tables 2 and 3, the abbreviations have the following meanings:

[0091] A-1, A-2, A-3, a-1: Each base oil shown in Table 1 B-1: Polyglycol monoalkyl ether (EO:PO=35:65, number average molecular weight 300, one end of the alkyl structure of the ether is butyl ether) B-2: Polyglycol monoalkyl ether (EO:PO=35:65, number average molecular weight 970, one end of the alkyl structure of the ether is butyl ether) C-1: Lauryl alcohol D-1: Polypropylene glycol Newpol PP200 (manufactured by Sanyo Chemical Industries, Ltd.) E-1: 1-dodecene

[0092] B-1 and B-2: The structure (ratio of oxyethylene groups, ratio of oxypropylene groups) and number average molecular weight of the polyglycol monoalkyl ethers were measured by the methods shown below.

[0093] [Structure of polyoxyalkylene compound] The structure of the polyoxyalkylene compound was analyzed by NMR measurement using 13C as the nuclide. NMR measurement conditions Measurement equipment: Agilent, product name "DD2" Magnet: 600MHz Nuclide: 13C Analytical methods: 1H inverse gated decoupling and DEPT135 Waiting time: 10 to 20 seconds Solvent: CDCl3

[0094] Oxyethylene group ratio The proportion of oxyethylene groups was determined by calculating the proportion of oxyethylene groups relative to the total amount (100 mol%) of oxyalkylene groups contained in the polyoxyalkylene compound. The oxypropylene group (OP) was quantified by [CH3 terminal derived from propylene oxide (PO) (integral value around 17 ppm) + CH derived from PO (integral value around 75 ppm)] / 2. The oxyethylene group (OE) was quantified by [sum of integral values ​​of all CH2 (downward-pointing peaks in the DEPT spectrum measured by DEPT135) - {CH3 terminal derived from PO (integral value around 17 ppm) + CH derived from PO (integral value around 75 ppm)} / 2] / 2. When the oxyalkylene groups in the polyoxyalkylene compound consisted only of oxypropylene groups and oxyethylene groups, the proportion (mol %) of oxyethylene groups was calculated by OE / (OE+OP)×100.

[0095] The proportion of oxypropylene groups bonded to the terminals of polyoxyalkylene compounds The proportion of oxypropylene groups bonded to the terminals of the polyoxyalkylene compound was determined by calculating the proportion of oxypropylene groups bonded to the terminals relative to the total amount (100 mol%) of oxyalkylene groups bonded to the terminals.

[0096] The proportion of oxyethylene groups bonded to the terminals of polyoxyalkylene compounds The proportion of oxyethylene groups bonded to the terminals of the polyoxyalkylene compound was determined by calculating the proportion of oxyethylene groups bonded to the terminals relative to the total amount (100 mol%) of oxyalkylene groups bonded to the terminals.

[0097] The oxypropylene groups bonded to the terminals (OP terminals) were quantified based on the integral values ​​near 65 ppm and 67 ppm in the above NMR measurement. The oxyethylene group bonded to the terminal (OE terminal) was quantified by the integrated value around 61 ppm in the above NMR measurement. When the oxyalkylene groups in a polyoxyalkylene compound consist only of oxypropylene groups and oxyethylene groups, the proportion (mol %) of oxypropylene groups bonded to the terminals was calculated by OP terminals / (OE terminals + OP terminals) x 100. The proportion (mol %) of oxyethylene groups bonded to the terminals was calculated by OE terminals / (OE terminals + OP terminals) x 100.

[0098] [Number average molecular weight] The number average molecular weight of the polyoxyalkylene compound was measured by gel permeation chromatography (GPC). GPC measurement conditions Measurement device: Waters, product name "Alliance2695" Column: Tosoh Corporation, product name "TSK-GEL GMHHR-M" x 2 (7.8 mm I.D. x 30 cm) Detector: RI Measurement conditions: column temperature 25°C, developing solvent tetrahydrofuran, flow rate 1.0 mL / min Sample: 2.0% by mass tetrahydrofuran solution Injection volume: 100μL Standard sample: polystyrene

[0099] [Evaluation of processing performance] An aluminum flat plate sliding test was conducted to evaluate the machinability of each metalworking oil composition. FIG. 1 is an explanatory diagram showing an outline of the flat plate sliding test. In FIG. 1, a test piece 1 was made of an aluminum alloy and was immersed in the metalworking oil composition of each example before being used for the test. The test piece 1 was clamped between a pair of flat plate blocks 2a and 2b, and a predetermined load (hereinafter referred to as "clamping load") was applied from the upper surface of the flat plate block 2a (arrow A in FIG. 1). Next, the test piece 1 to which the clamping load had been applied was pulled out horizontally (arrow B in FIG. 1). The pull-out load when pulling out the test piece 1 was measured, and the results are shown in Tables 2 and 3. The smaller the pull-out load when pulling out the test piece 1, the better the machinability of the metalworking oil composition. The details of the test conditions are as follows:

[0100] <Test conditions> Aluminum test piece: JIS A1050 material Flat block 2a, 2b: SKD-11, 300mm (width) x 600mm (length) x 10mm (thickness), contact area with test piece 1: 10mm x 250mm Clamping load: 1.5kN Pulling speed: 100mm / min Temperature of the metalworking oil composition of each example at the time of immersion application: 40°C ± 3°C Temperature of test piece 1 during the test: 25°C ± 3°C Temperature of the flat block: 25°C ± 3°C

[0101] [Evaluation of hydrophilicity] <Measurement of contact angle after drying> An aluminum test piece (JIS A1050 material) was immersed in each metalworking oil composition for 5 minutes. The aluminum test piece was then removed, dried at 140°C for 7 minutes, and cooled to room temperature (25°C). 0.002 mL of water was then dropped onto the test piece, and the contact angle was measured. The average values ​​of three measurements are shown in Tables 2 and 3. A contact angle of 15° or less was considered acceptable.

[0102] <Measurement of contact angle after rinsing with water> An aluminum test piece (JIS A1050 material) was immersed in each metalworking oil composition for 5 minutes. The aluminum test piece was then removed and dried at 140°C for 7 minutes. The aluminum test piece was then suspended in a beaker, and tap water was poured into it without directly contacting the aluminum test piece, and the aluminum test piece was rinsed for 30 minutes. The aluminum test piece was then dried at 80°C for 10 minutes, cooled to room temperature (25°C), and 0.002 mL of water was dropped onto the test piece, and the contact angle was measured. The average values ​​of three measurements are shown in Tables 2 and 3. A contact angle of 15° or less was considered acceptable.

[0103] [Table 2]

[0104] [Table 3]

[0105] As shown in Tables 2 and 3, it was confirmed that the metalworking oil compositions of Examples 1 to 8 had better processability and could improve the hydrophilicity of metals compared to the metalworking oil compositions of Comparative Examples 1 to 3. In the metalworking oil compositions of Examples 1 to 8, low-molecular-weight additives derived from component (B) remained after drying, and because base oil (A) with moderate branching was used, component (B) was more easily adsorbed to the aluminum surface, resulting in a lower contact angle and better hydrophilicity than the metalworking oil compositions of Comparative Examples 1 to 3. Furthermore, the metal working oil compositions of Examples 1 to 8 had a lower contact angle and better hydrophilicity than the metal working oil compositions of Comparative Examples 1 to 3 because the low molecular weight additive derived from component (B) remained even after rinsing with water.

Claims

1. The composition contains a base oil (A) and a polyoxyalkylene compound (B) having a repeating structure of an oxyethylene group and a repeating structure of an oxypropylene group, The base oil (A) is １ A metal working oil composition comprising a branched chain hydrocarbon (A1) having a methyl group proton ratio of 20 to 65, where the integral value of all protons detected by H-NMR analysis is taken as 100.

2. 2. The metal working oil composition according to claim 1, wherein the branched-chain hydrocarbons (A1) have a ratio (CB / CA) of a proportion of hydrocarbons having the highest proportion of carbon atoms (CA) to a proportion of hydrocarbons having the second highest proportion of carbon atoms (CB) in a carbon number distribution obtained by gas chromatography distillation of 0.4 or more.

3. 3. The metal working oil composition according to claim 1, wherein the branched chain hydrocarbons (A1) have a proportion (CC) of hydrocarbons having 10 or less carbon atoms of 20 mass% or more in a carbon number distribution obtained by gas chromatographic distillation.

4. 3. The metal working oil composition according to claim 1, wherein the polyoxyalkylene compound (B) has an EO / PO molar ratio of 1.0 to 3.

0.

5. 3. The metal working oil composition according to claim 1, wherein the polyoxyalkylene compound (B) has a number average molecular weight (Mn) of 450 or less.

6. 3. The metal working oil composition according to claim 1, wherein the proportion of the branched chain hydrocarbon (A1) in the base oil (A) is 30 mass % or more and 100 mass % or less.

7. The metal working oil composition according to claim 1 or 2, which is used in the production of aluminum fins.

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