Aqueous heat treatment liquid composition, method for manufacturing metal materials, and apparatus for manufacturing metal materials

Abstract

The present invention provides an aqueous heat treatment fluid composition that exhibits little change in cooling rate even after repeated use. [Solution] An aqueous heat treatment liquid composition according to one aspect of the present disclosure contains water (A), polyalkylene glycols (B) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and compound (C), wherein the cloud point of (C) is 10°C or higher, and the cloud point of (C) is 10°C or lower than the cloud point of (B).

Description

[Technical Field]

[0001] This disclosure relates to an aqueous heat treatment liquid composition, a method for producing a metal material using the aqueous heat treatment liquid composition, and an apparatus for producing a metal material. [Background technology]

[0002] Coolants used for quenching metal materials include, for example, (i) gas or salt solution, (ii) oil-based or water-based (water-soluble) quenching fluid, (iii) water, and (iv) salt water. Cooling properties vary depending on the type of coolant, with a tendency for the cooling properties to increase in the order of (i), (ii), (iii), and (iv). Using a coolant with high cooling properties can produce harder metal materials, but on the other hand, it increases the risk of distortion and quench cracking. For this reason, the type of coolant is selected according to the desired hardness and allowable amount of distortion in the metal material after quenching.

[0003] Among these coolants, water-based quenching fluids are widely used because they have many advantages over oil-based quenching fluids, such as: higher cooling performance; the ability to adjust cooling performance by dilution concentration; less risk of fire because they do not burn like oil; reduced oil usage because they can be diluted; and a reduced risk of distortion and cracking compared to water.

[0004] For example, Patent Document 1 discloses an aqueous quenching solution composition comprising water (A), linear polyalkylene glycols (B), and a branched polyhydric alcohol alkylene oxide adduct (C), wherein the linear polyalkylene glycol (B) has a mass-average molecular weight of 10,000 or more, and the branched polyhydric alcohol alkylene oxide adduct (C) is a mixed adduct of alkylene oxides having 2 to 3 carbon atoms and has a mass-average molecular weight of 10,000 or more.

[0005] The aqueous quenching liquid composition of Patent Document 1 contains two types of polyalkylene glycol (PAG) having a mass average molecular weight of 10,000 or more at a predetermined mixing ratio, whereby the cooling rate is slow and quenching cracking can be suppressed.

Prior Art Document

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0007] However, polymers such as PAG may be damaged by thermal load. Therefore, in an aqueous quenching liquid composition containing PAG like the aqueous quenching liquid composition of Patent Document 1, repeated heat treatment may damage the PAG due to thermal load and change the cooling performance.

[0008] An object of one aspect of the present disclosure is to provide an aqueous heat treatment liquid composition with little change in cooling rate even when used repeatedly.

Means for Solving the Problem

[0009] The present inventors, through diligent research to solve the above problems, have discovered for the first time that by blending a specific PAG with a compound having a cloud point of 10°C or higher and a cloud point 10°C or higher lower than that of the PAG, it is possible to realize an aqueous heat treatment liquid composition that exhibits little change in cooling rate even with repeated use, thus completing the present invention. That is, in order to solve the above problems, an aqueous heat treatment liquid composition according to one aspect of the present disclosure contains water (A), polyalkylene glycols (B) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and compound (C), wherein the cloud point of compound (C) is 10°C or higher, and the cloud point of compound (C) is 10°C or higher lower than the cloud point of polyalkylene glycols (B). [Effects of the Invention]

[0010] According to one aspect of this disclosure, it is possible to provide an aqueous heat treatment fluid composition that exhibits little change in cooling rate even after repeated use. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows the results of the examples, illustrating the relationship between the rate of change in kinematic viscosity at 40°C or the change in cooling rate of each aqueous heat treatment fluid composition and the cloud point of component (C). [Figure 2] This figure shows the results of the examples, specifically the relationship between the rate of change in cooling rate and the cloud point of component (C) for each aqueous heat treatment liquid composition. [Modes for carrying out the invention]

[0012] One aspect of the present invention will be described in detail below. Unless otherwise specified in this specification, "A to B" representing a numerical range means "greater than or equal to A and less than or equal to B".

[0013] [1. Aqueous heat treatment fluid composition] An aqueous heat treatment liquid composition according to one aspect of this disclosure contains water (A), polyalkylene glycols (B) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and compound (C), wherein the cloud point of compound (C) is 10°C or higher, and the cloud point of compound (C) is 10°C or lower than the cloud point of polyalkylene glycols (B). The above configuration provides the following effects.

[0014] (1) Good durability The aqueous heat treatment fluid composition according to one aspect of this disclosure exhibits minimal change in cooling rate even with repeated use in heat treatment and has excellent durability, thus maintaining its cooling performance even after repeated use. Furthermore, by using the aqueous heat treatment fluid composition according to one aspect of this disclosure, the frequency of heat treatment fluid replacement can be reduced, thus contributing to the environment. Such effects contribute, for example, to achieving Goal 12 of the United Nations Sustainable Development Goals (SDGs), "Ensure sustainable consumption and production patterns."

[0015] (2) Suppression of the cooling rate Regarding the quenching of metal materials, when a heated metal material is immersed in an aqueous quenching solution, the cooling rate is not constant and typically proceeds through the following three stages. Stage 1 (Vapor Film Stage): In this stage, the metal material is covered with vapor from an aqueous quenching solution and cooled through the vapor film. Stage 2 (Boiling Stage): The vapor film breaks down, and the foamy heat treatment oil comes into contact with the metal surface. Third stage (convection stage): This is the stage where the temperature of the metal material falls below the boiling point of the aqueous quenching solution, and cooling proceeds through convection of the aqueous quenching solution.

[0016] In conventional aqueous quenching solutions, since the boiling point of water is 100°C, the metal material cools rapidly to around 100°C after the vapor film breaks. In other words, when using conventional aqueous quenching solutions, the cooling rate in the temperature range where martensite is formed in the second stage (boiling stage) is fast, which can cause localized temperature differences in the metal material, making it prone to distortion and quench cracking.

[0017] In contrast, the aqueous heat treatment fluid composition according to one aspect of this disclosure has a suppressed cooling rate during heat treatment, and therefore, by using the aqueous heat treatment fluid composition according to one aspect of this disclosure as a quenching fluid or tempering fluid, cooling can be mitigated. For example, cooling can be mitigated by suppressing the 350-150°C cooling rate, which is one of the indicators of the coolability of aqueous quenching fluids. Hereinafter, in this specification, the "350-150°C cooling rate" means the cooling rate (°C / s) calculated from the cooling time in the temperature range from 350°C to 150°C, measured in accordance with the cooling performance test method (Method B: core temperature measurement method) for water-soluble quenching fluids specified in JIS K2242:2012.

[0018] According to one aspect of the present disclosure, the aqueous heat treatment fluid composition can suppress the cooling rate during heat treatment and mitigate cooling, thereby reducing the risk of distortion and quench cracking in metal materials due to heat treatment.

[0019] As described above, the aqueous heat treatment fluid composition according to one aspect of this disclosure has good durability, and even after repeated use, the cooling rate suppression effect and, consequently, the effect of reducing the risk of distortion and quench cracking in metal materials due to heat treatment are maintained.

[0020] The components contained in the aqueous heat treatment liquid composition according to one aspect of this disclosure are described below.

[0021] <Water (A)> A water-based heat treatment fluid composition according to one aspect of this disclosure is a water-based heat treatment composition containing water (A) (hereinafter sometimes referred to as "component (A)"), and therefore has the following advantages compared to oil-based quenching fluids: high cooling performance; cooling performance can be adjusted by dilution concentration; high safety due to the low risk of fire as it does not burn like oil; and the amount of oil used can be reduced because it can be used after dilution.

[0022] In an aqueous heat treatment fluid composition according to one aspect of this disclosure, the type of component (A) is not particularly limited. For example, distilled water, deionized water, tap water, industrial water, etc., can be used as component (A).

[0023] <Polyalkylene glycols (B) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide> A water-based heat treatment liquid composition according to one aspect of this disclosure contains polyalkylene glycols (B) (hereinafter sometimes referred to as "component (B)") which include repeating units derived from ethylene oxide (EO units) and repeating units derived from alkylene oxides other than ethylene oxide (AO units other than EO). As a result, component (B) precipitates when the material is treated at high temperatures, suppressing the cooling rate between 350 and 150°C and mitigating the cooling process. Furthermore, the cooling performance can be adjusted by the content of component (B) in the water-based heat treatment liquid composition according to one aspect of this disclosure.

[0024] Component (B) in an aqueous heat treatment fluid composition according to one aspect of this disclosure may include, for example, linear polyalkylene glycols containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide; and branched polyhydric alcohol adducts of ethylene oxide and alkylene oxides other than ethylene oxide. Component (B) in an aqueous heat treatment fluid composition according to one aspect of this disclosure preferably has a cloud point. Here, "cloud point" in this specification can be measured in accordance with the measurement method of ASTM D2024.

[0025] (Linear polyalkylene glycols containing repeating units derived from ethylene oxide (EO units) and repeating units derived from alkylene oxides other than ethylene oxide (AO units other than EO units)) Examples of linear polyalkylene glycols containing EO units and AO units other than EO include compounds represented by the following general formula (I). R 1 O-(RA O) n -R 2 ··· (I) In the formula (I), R A represents an alkylene group having 2 to 6 carbon atoms. R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group having 1 to 18 carbon atoms, a saturated alicyclic hydrocarbon group having 5 to 18 carbon atoms which may have a substituent(s), an unsaturated alicyclic hydrocarbon group having 5 to 18 carbon atoms which may have a substituent(s), or an aromatic hydrocarbon group having 5 to 18 carbon atoms which may have a substituent(s). n is an integer of 2 or greater such that the weight average molecular weight (Mw) of the compound falls within the numerical range described below (for example, 8,000 or more). A preferred numerical range for the weight average molecular weight of the compound will be described later.

[0026] Examples of said "alkylene group having 2 to 6 carbon atoms" in formula (I) include an ethylene group, a propylene group, an ethylmethylene group, a 1,1-dimethylethylene group, a 1,2-dimethylethylene group, an n-butylethylene group, an isobutylethylene group, a 1-ethyl-2-methylethylene group, a 1-ethyl-1-methylethylene group, a trimethylene group, a tetramethylene group, and a pentamethylene group.

[0027] R in formula (I) 1 and R 2 Examples of said "alkyl group having 1 to 10 carbon atoms" represented by 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, a hexyl group, a 2-ethylhexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.

[0028] R in formula (I) 1 and R 2 Examples of said "acyl group having 1 to 18 carbon atoms" represented by include a group having an alkyl group of 1 to 17 carbon atoms and a carbonyl group. R in formula (I) 1 and R 2The "acyl group having 1 to 18 carbon atoms" indicated by the above is preferably an acyl group having 1 to 11 carbon atoms.

[0029] R in equation (I) above 1 and R 2 Examples of the "saturated alicyclic hydrocarbon group having 5 to 18 carbon atoms" shown include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl group.

[0030] R in equation (I) above 1 and R 2 Examples of the "unsaturated alicyclic hydrocarbon group having 5 to 18 carbon atoms" shown include the cyclopentenyl group and cyclohexenyl.

[0031] R in equation (I) above 1 and R 2 Examples of the "aromatic hydrocarbon groups having 5 to 18 carbon atoms" shown include aryl groups such as phenyl groups and naphthyl groups.

[0032] The saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, and aromatic hydrocarbon groups having 5 to 18 carbon atoms mentioned above may have substituents. Examples of such substituents include alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, and aryl groups having 6 to 14 carbon atoms.

[0033] Straight-chain polyalkylene glycols containing EO units and AO units other than EO are defined as (R) in formula (I) above. AThe O) unit includes ethylene oxide and alkylene oxides other than ethylene oxide. The alkylene oxide other than ethylene oxide is not particularly limited and can be arbitrarily selected from alkylene oxides having 3 to 6 carbon atoms, for example, propylene oxide and butylene oxide. The AO unit other than EO may be one type or a combination of two or more types. For example, the AO unit other than EO may be a propylene oxide unit, a butylene oxide unit, or a combination of a propylene oxide unit and a butylene oxide unit. Furthermore, the mixture may further contain alkylene oxide units other than propylene oxide units and butylene oxide units.

[0034] (R in equation (I) above) A The bonding mode of the 0) units is not particularly limited and includes, for example, random bonding (random copolymer), block bonding (block copolymer), graft bonding (graft copolymer), and alternating bonding (alternating copolymer). The block copolymer may be a reverse pluronic block copolymer or a reverse stetronic block copolymer. The bonding mode in linear polyalkylene glycols containing EO units and AO units other than EO may be any of these bonding modes, but from the viewpoint of the manufacturing cost of the copolymer, a random bonding mode is preferred.

[0035] Linear polyalkylene glycols containing EO units and AO units other than EO are preferably water-soluble. In this specification, among the compounds of general formula (I) above, R 1 and R 2 When both are hydrogen, it is called a polyalkylene glycol, 1 and R 2 A polyalkylene glycol derivative is defined as one in which at least one of the groups is a group other than hydrogen. Therefore, in this specification, the term "polyalkylene glycols" encompasses both polyalkylene glycols and polyalkylene glycol derivatives.

[0036] In linear polyalkylene glycols containing EO units and non-EO AO units, the ratio (P1:Q1) of the number of moles of EO units added (P1) to the number of moles of non-EO AO units added (Q1) in the molecule is preferably 50:50 or higher, more preferably 60:40 or higher, and even more preferably 67:33 or higher, from the viewpoint of improving solubility in water. Furthermore, from the viewpoint of cloud point, the ratio (P1:Q1) is preferably 91:9 or less, more preferably 90:10 or less, and even more preferably 86:14 or less. The upper and lower limits of these numerical ranges may be combined in any way; for example, the ratio (P1:Q1) is preferably 50:50 to 91:9, more preferably 60:40 to 90:10, and even more preferably 67:33 to 86:14. Furthermore, if a linear polyalkylene glycol containing both EO units and non-EO AO units contains two or more types of non-EO AO units, the number of moles of non-EO AO units added (Q1) shall be the sum of all non-EO AO units.

[0037] The mass-average molecular weight (Mw) of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 12,000 or more, from the viewpoint of sufficiently obtaining the effect of suppressing the cooling rate at 350-150°C. Furthermore, the mass-average molecular weight of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 50,000 or less, more preferably 40,000 or less, more preferably 30,000 or less, even more preferably 28,000 or less, and even more preferably 25,000 or less, from the viewpoint of viscosity. The upper and lower limits of these numerical ranges may be combined in any way. For example, the mass-average molecular weight of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 8,000 to 50,000, more preferably 8,000 to 40,000, more preferably 8,000 to 30,000, even more preferably 10,000 to 28,000, and even more preferably 12,000 to 25,000.

[0038] The ratio (Mw / Mn) of the mass-average molecular weight (Mw) to the number-average molecular weight (Mn) of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 1.5 to 10, more preferably 2.8 to 9, and even more preferably 2.5 to 5. In this specification, the mass-average molecular weight and number-average molecular weight of polyalkylene glycols are measured by gel permeation chromatography (GPC) under the following measurement conditions and represent the values ​​converted to standard polystyrene. <Measurement Conditions> Column: TSKgel GMPWXL x 2, manufactured by Tosoh Corporation Guard column: Shodex LF-G Flow rate: 1.0mL / min Mobile phase: 0.2M NaNO3aq. Sample injection volume: 100 μL Column oven temperature: 40℃ Detector: RI-1530, manufactured by JASCO Corporation

[0039] Preferred examples of linear polyalkylene glycols containing EO units and AO units other than EO include the polyoxyethylene polyoxypropylene glycols No. 1 to 11 shown in Table 1 below.

[0040] [Table 1]

[0041] (Adducts of branched polyhydric alcohols with ethylene oxide and alkylene oxides other than ethylene oxide) Adducts of branched polyhydric alcohols with ethylene oxide and alkylene oxides other than ethylene oxide (hereinafter referred to as "AO adducts of branched polyhydric alcohols other than EO·EO") are obtained by adding ethylene oxide and alkylene oxides other than ethylene oxide to branched polyhydric alcohols.

[0042] The alkylene oxide other than ethylene oxide is not particularly limited and can be arbitrarily selected from alkylene oxides having 3 to 6 carbon atoms, for example, propylene oxide and butylene oxide. The AO other than EO may be one type or a combination of two or more types. For example, the AO other than EO may be propylene oxide, butylene oxide, or a combination of propylene oxide and butylene oxide. Furthermore, the material may further contain alkylene oxides other than propylene oxide and butylene oxide.

[0043] In the molecule of a branched polyhydric alcohol EO·EO-non-EO adduct, the ratio (P1:Q1) of the number of moles of EO units added (P1) to the number of moles of AO units other than EO (Q1) is preferably 50:50 or higher, more preferably 60:40 or higher, and even more preferably 67:33 or higher, from the viewpoint of improving solubility in water. Furthermore, from the viewpoint of cloud point, the ratio (P1:Q1) is preferably 91:9 or less, more preferably 90:10 or less, and even more preferably 86:14 or less. The upper and lower limits of these numerical ranges may be combined in any way; for example, the ratio (P1:Q1) is preferably 50:50 to 91:9, more preferably 60:40 to 90:10, and even more preferably 67:33 to 86:14. Furthermore, if a branched polyhydric alcohol AO adduct other than EO·EO contains two or more types of AO units other than EO, the number of moles of AO units other than EO (Q1) shall be the sum of all AO units other than EO.

[0044] The polyhydric alcohol used as a raw material for branched polyhydric alcohol AO adducts other than EO·EO is not particularly limited as long as it has 3 or more hydroxyl groups, but the number of hydroxyl groups is preferably 3 to 8, more preferably 3 to 6, and even more preferably 3 to 4. Furthermore, from the viewpoint of solubility in water, the polyhydric alcohol used as a raw material for branched polyhydric alcohol AO adducts other than EO·EO preferably has 3 to 10 carbon atoms, more preferably 3 to 6, and even more preferably 3 to 4. Specific examples of the polyhydric alcohol include glycerin, diglycerin, polyglycerin, trimethylolpropane, and pentaerythritol, among which glycerin is preferred.

[0045] The bonding modes of EO and non-EO AO in branched polyhydric alcohol EO·EO-non-AO adducts are not particularly limited, and examples include random bonding (random copolymer), block bonding (block copolymer), graft bonding (graft copolymer), and alternating bonding (alternating copolymer). The block copolymer may be a reverse pluronic block copolymer or a reverse stetronic block copolymer. The bonding modes in branched polyhydric alcohol EO·EO-non-AO adducts may be any of these bonding modes, but from the viewpoint of copolymer manufacturing cost, the random bonding mode is preferred.

[0046] Branched polyhydric alcohol adducts other than EO·EO are preferably water-soluble.

[0047] The mass-average molecular weight (Mw) of branched polyhydric alcohol AO adducts other than EO·EO is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 12,000 or more, from the viewpoint of sufficiently obtaining the effect of suppressing the cooling rate at 350-150°C. Furthermore, from the viewpoint of viscosity, the mass-average molecular weight of the branched polyhydric alcohol AO adduct other than EO·EO is preferably 50,000 or less, more preferably 40,000 or less, more preferably 30,000 or less, even more preferably 28,000 or less, and even more preferably 25,000 or less. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, the mass-average molecular weight of branched polyhydric alcohol AO adducts other than EO·EO is preferably 8,000 to 50,000, more preferably 8,000 to 40,000, more preferably 8,000 to 30,000, even more preferably 10,000 to 28,000, and even more preferably 12,000 to 25,000.

[0048] The ratio (Mw / Mn) of the mass-average molecular weight (Mw) to the number-average molecular weight (Mn) of branched polyhydric alcohol AO adducts other than EO·EO is preferably 1.5 to 10, more preferably 2.8 to 9, and even more preferably 2.5 to 5.

[0049] Preferred examples of branched polyhydric alcohol AO adducts other than EO·EO include the EO·PO adduct of glycerin No. 12 and the EO·PO adducts of pentaerythritol Nos. 13-14 (CAS number: 58205-99-5), as shown in Table 2 below.

[0050] [Table 2]

[0051] Component (B) may be used alone or in combination of two or more types. Component (B) may also be a combination of linear polyalkylene glycols containing EO units and AO units other than EO, and branched polyhydric alcohols with AO adducts other than EO.

[0052] <Compound (C)> A water-based heat treatment fluid composition according to one aspect of this disclosure contains compound (C) (hereinafter sometimes referred to as "component (C)"), which provides good durability for repeated use. The mechanism is presumed to be as follows: Component (C) has a cloud point of 10°C or higher, and its cloud point is 10°C or higher lower than that of component (B). Due to this difference in cloud points between component (B) and component (C), component (C) precipitates first on the surface of a high-temperature workpiece (e.g., a metal material), and then component (B) precipitates on top of it. The precipitation of component (B) on the surface of the high-temperature workpiece suppresses the cooling rate and mitigates the cooling process. Furthermore, the presence of component (C) between the surface of the high-temperature workpiece and component (B) reduces direct contact between the surface of the high-temperature workpiece and component (B), thereby suppressing damage to component (B) due to thermal load. As a result, it is presumed that the cooling rate does not change much even when repeatedly used for heat treatment, resulting in excellent durability.

[0053] Component (C) having a cloud point of 10°C or higher has good solubility in water at 10°C. From the viewpoint of further improving solubility in water, the cloud point of component (C) is preferably 15°C or higher, more preferably 20°C or higher, even more preferably 27°C or higher, and even more preferably 30°C or higher. Furthermore, the upper limit of the cloud point of component (C) is not particularly limited, but for example, it is 70°C or lower. The upper and lower limits of these numerical ranges may be combined in any way; for example, the cloud point of component (C) is preferably 15 to 70°C, more preferably 20 to 70°C, even more preferably 27 to 70°C, and even more preferably 30 to 70°C.

[0054] Regarding the difference between the cloud point of component (B) and the cloud point of component (C), if the cloud point of component (C) is 10°C or more lower than the cloud point of component (B), the change in cooling rate due to repeated use can be reduced. From the viewpoint of further reducing the change in cooling rate, it is preferable that the cloud point of component (C) is 20°C or more lower than the cloud point of component (B). As long as the cloud point of component (C) is 10°C or higher, there is no particular upper limit to the difference between the cloud points of component (B) and component (C).

[0055] The mass-average molecular weight of component (C) is preferably smaller than that of component (B). Furthermore, considering the influence of component (C) on cooling performance, a smaller mass-average molecular weight of component (C) is preferable from the viewpoint of reducing its influence on cooling performance. For example, the mass-average molecular weight of component (C) is preferably 30,000 or less, more preferably 25,000 or less, more preferably 20,000 or less, more preferably 15,000 or less, more preferably 10,000 or less, even more preferably 6,000 or less, and even more preferably 5,000 or less. From the viewpoint of the cloud point, the lower limit of the mass-average molecular weight of component (C) is preferably 150 or higher, more preferably 250 or higher, even more preferably 350 or higher, and even more preferably 500 or higher. The upper and lower limits of these numerical ranges may be combined in any way. For example, the mass-average molecular weight of component (C) is preferably 150 to 30,000, more preferably 150 to 25,000, more preferably 150 to 20,000, more preferably 150 to 15,000, more preferably 150 to 10,000, more preferably 150 to 6,000, more preferably 150 to 5,000, even more preferably 250 to 5,000, even more preferably 350 to 5,000, and even more preferably 500 to 5,000.

[0056] Furthermore, the difference between the mass-average molecular weight of component (B) and the mass-average molecular weight of component (C) is preferably 5,000 or more, and more preferably 8,000 or more, taking into consideration its effect on the cooling properties of component (C). The upper limit of the difference between the mass-average molecular weight of component (B) and the mass-average molecular weight of component (C) is not particularly limited, but for example, it is 29,800 or less.

[0057] In an aqueous heat treatment liquid composition according to one aspect of this disclosure, a compound having the above-mentioned cloud point and mass-average molecular weight can be selected as component (C). For example, a compound can be selected from among polyalkylene glycols and polyglyceryl ethers to be used as component (C).

[0058] (Second type of polyalkylene glycol (C1)) In one aspect of the present disclosure, polyalkylene glycols having the above-described cloud point and molecular weight can be used as component (C) in the aqueous heat treatment liquid composition. To distinguish the polyalkylene glycols used as component (C) from the polyalkylene glycols of component (B), they are referred to herein as "second polyalkylene glycols (C1)," and for convenience of explanation, they may be simply referred to as "component (C1)."

[0059] Examples of component (C1) include linear polyalkylene glycols and branched polyhydric alcohol alkylene oxide adducts.

[0060] (Second type of linear polyalkylene glycol) Examples of the second type of linear polyalkylene glycol include compounds represented by the following general formula (II). R 3 O-(R B O) m -R 4 ... (II) In the above equation (II), R B R represents an alkylene group with 2 to 6 carbon atoms. 3 and R 4Each of these independently represents a hydrogen atom, a nitrogen atom, an amino group, an alkyl group having 1 to 36 carbon atoms, an acyl group having 1 to 24 carbon atoms, a saturated alicyclic hydrocarbon group having 5 to 18 carbon atoms which may have substituents, an unsaturated alicyclic hydrocarbon group having 5 to 18 carbon atoms which may have substituents, or an aromatic hydrocarbon group having 5 to 18 carbon atoms which may have substituents. m is an integer of 2 or more (e.g., 4 or more) such that the mass-average molecular weight (Mw) of the compound is within the numerical range described above (e.g., 150 or more). The preferred numerical range for the mass-average molecular weight of the compound is as described above as the preferred numerical range for the mass-average molecular weight of component (C).

[0061] (R B O) When there are multiple units, i.e., when m≧2, each (R B O) The units may be the same or different. (R in formula (II) above B O) The unit is not particularly limited and can be arbitrarily selected from alkylene oxides having 2 to 6 carbon atoms, for example, ethylene oxide, propylene oxide, and butylene oxide.

[0062] (R in equation (II) above) B The bonding pattern of the O) units is as described for linear polyalkylene glycols containing EO units (component B) and AO units other than EO.

[0063] More specific embodiments of the second linear polyalkylene glycols include the following: (i) (R) of formula (II) above B O) The unit consists of one type of alkylene oxide, such as propylene oxide or butylene oxide, R 3 and R 4 The second linear polyalkylene glycol a is a hydrogen atom; (ii) (R) of formula (II) above B O) The unit is composed of two or more alkylene oxides selected from ethylene oxide, propylene oxide, and butylene oxide, R 3 and R4 The second linear polyalkylene glycol b is a hydrogen atom; (iii) End R of formula (II) 3 and R 4 A second linear polyalkylene glycol derivative wherein at least one of the following is a nitrogen atom, an amino group, an alkyl group having 1 to 36 carbon atoms, an acyl group having 1 to 24 carbon atoms, a saturated alicyclic hydrocarbon group having 5 to 18 carbon atoms which may have substituents, an unsaturated alicyclic hydrocarbon group which may have substituents, or an aromatic hydrocarbon group which may have substituents.

[0064] Examples of the "alkylene group having 2 to 6 carbon atoms" in formula (II) above include ethylene group, propylene group, ethylmethylene group, 1,1-dimethylethylene group, 1,2-dimethylethylene group, n-butylethylene group, isobutylethylene group, 1-ethyl-2-methylethylene group, 1-ethyl-1-methylethylene group, trimethylene group, tetramethylene group, pentamethylene group, and the like.

[0065] R in equation (II) above 3 and R 4 Examples of the "alkyl group having 1 to 36 carbon atoms" shown in the above formula (II) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, hexyl group, 2-ethylhexyl group, heptyl group, octyl group, nonyl group, decyl group, and behenyl group. 1 and R 2 The "alkyl group having 1 to 36 carbon atoms" shown above may, for example, be an alkyl group having 1 to 36 carbon atoms, an alkyl group having 1 to 22 carbon atoms, or an alkyl group having 1 to 10 carbon atoms.

[0066] R in equation (II) above 3 and R 4 The "acyl group having 1 to 24 carbon atoms" shown by can be, for example, a group having an alkyl group and a carbonyl group having 1 to 23 carbon atoms. 1 and R2 The "acyl group having 1 to 24 carbon atoms" indicated by the above is preferably an acyl group having 1 to 18 carbon atoms.

[0067] R in equation (II) above 3 and R 4 Examples of the "saturated alicyclic hydrocarbon group having 5 to 18 carbon atoms" shown include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl group.

[0068] R in equation (II) above 3 and R 4 Examples of the "unsaturated alicyclic hydrocarbon group having 5 to 18 carbon atoms" shown include the cyclopentenyl group and cyclohexenyl.

[0069] R in equation (II) above 3 and R 4 Examples of the "aromatic hydrocarbon groups having 5 to 18 carbon atoms" shown include aryl groups such as phenyl groups and naphthyl groups.

[0070] The saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, and aromatic hydrocarbon groups having 5 to 18 carbon atoms mentioned above may have substituents. Examples of such substituents include alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, and aryl groups having 6 to 14 carbon atoms.

[0071] The ratio (P2:Q2) of the number of moles of EO units (P2) to the number of moles of AO units other than EO (Q2) in the molecule of the second linear polyalkylene glycol can be selected from the range of 0:100 to 100:0, but the R in formula (I) 3 It is preferable to change the range of possible ratios (P2:Q2) depending on the type. For example, R in equation (II) above 3When the atom is a hydrogen atom, the ratio (P2:Q2) is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. Also, R in equation (II) 3 If is an atom or group other than a hydrogen atom, the ratio (P2:Q2) is 0:100 to 100:0, preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. Furthermore, if the second linear polyalkylene glycol contains two or more types of AO units other than EO, the number of moles of AO units other than EO (Q2) shall be the sum of all AO units other than EO.

[0072] Preferred examples of the second linear polyalkylene glycol include the linear polyalkylene glycols shown in Table 3 of the Examples described later. Other preferred examples include the second linear polyalkylene glycol, which may be an amine having a nitrogen atom or amino group at its terminus or in its molecule. Examples include polyoxyalkylene alkylamines and their derivatives, such as polyoxyethylene laurylamine, polyoxyethylene tallowamine, polyoxyethylene stearylamine, and polyoxyethylene tallowpropylenediamine. Further preferred examples of the second linear polyalkylene glycol include polyoxyalkylene alkyl ethers and their derivatives, such as polyoxyethylene behenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecylphenyl ether, and polyoxyethylene styrene-phenyl ether.

[0073] (Second branched polyhydric alcohol alkylene oxide adduct) The second branched polyhydric alcohol alkylene oxide adduct is an adduct of one or more alkylene oxides. The alkylene oxide is not particularly limited and can be arbitrarily selected from alkylene oxides having 2 to 6 carbon atoms, for example, ethylene oxide, propylene oxide, and butylene oxide. The alkylene oxide may be one type or a combination of two or more types. For example, the alkylene oxide may be ethylene oxide, propylene oxide, butylene oxide, or a combination of two or more types selected from ethylene oxide, propylene oxide, and butylene oxide. It may also further contain alkylene oxides other than ethylene oxide, propylene oxide, and butylene oxide.

[0074] The ends of the second branched polyhydric alcohol alkylene oxide adduct molecule may be a hydrogen atom, a nitrogen atom, an amino group, a C1-C36 alkyl group, a C1-C24 acyl group, an optionally substituted C5-C18 saturated alicyclic hydrocarbon group, an optionally substituted C5-C18 unsaturated alicyclic hydrocarbon group, or an optionally substituted C5-C18 aromatic hydrocarbon group. These groups are as described for the second linear polyalkylene glycols.

[0075] In the molecule of the second branched polyhydric alcohol alkylene oxide adduct, the ratio (P2:Q2) of the number of moles of EO units added (P2) to the number of moles of AO units other than EO (Q2) can be selected from the range of 0:100 to 100:0, but it is preferable to change the range of possible values ​​of the ratio (P2:Q2) depending on the type of atom or group present at the end of the molecule. For example, if the terminal end of the molecule is a hydrogen atom, the ratio (P2:Q2) is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. Furthermore, if the terminal end of the molecule is an atom or group other than a hydrogen atom, the ratio (P2:Q2) is 0:100 to 100:0, preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. Furthermore, if the second branched polyhydric alcohol alkylene oxide adduct contains two or more types of AO units other than EO, the number of moles of AO units other than EO (Q2) shall be the sum of all AO units other than EO.

[0076] The types of polyhydric alcohols that serve as raw materials for the second branched polyhydric alcohol alkylene oxide adduct, and the mode of alkylene oxide bonding, are as explained for AO adducts other than EO·EO of the branched polyhydric alcohol, which is component (B).

[0077] The second branched polyhydric alcohol alkylene oxide adduct is preferably water-soluble.

[0078] The preferred numerical range for the mass-average molecular weight (Mw) of the second branched polyhydric alcohol alkylene oxide adduct is as described above as the preferred numerical range for the mass-average molecular weight of component (C).

[0079] A second preferred example of a branched polyhydric alcohol alkylene oxide adduct is the branched polyhydric alcohol alkylene oxide adduct shown in Table 3 of the examples described later.

[0080] (Polyglyceryl ethers (C2)) The polyglyceryl ethers are not particularly limited, and examples include polyoxyalkylene polyglyceryl ethers such as polyoxyethylene polyglyceryl ether, polyoxypropylene polyglyceryl ether, and polyoxyethylene polyoxypropylene polyglyceryl ether.

[0081] The preferred numerical range for the mass-average molecular weight (Mw) of polyglyceryl ethers (C2) is as described above, as the preferred numerical range for the mass-average molecular weight of component (C).

[0082] Component (C) may be used alone or in combination of two or more types. For example, as component (C1), a second linear polyalkylene glycol and a second branched polyhydric alcohol alkylene oxide adduct may be used in combination. Alternatively, component (C1) and component (C2) may be used in combination.

[0083] (Preferred example of component (C)) From the viewpoint of availability, component (C) is preferably a second polyalkylene glycol (C1).

[0084] (Examples of preferred combinations of component (B) and component (C)) Component (B) and component (C) should be combined such that at least the following conditions (i) to (ii) are satisfied, preferably at least the following conditions (i) to (iii), and more preferably all of the following conditions (i) to (iv): (i) The cloud point of component (C) is 10°C or more lower than the cloud point of component (B); (ii) The cloud point of component (C) is 10°C or higher; (iii) The difference between the mass-average molecular weight of component (B) and the mass-average molecular weight of component (C) [(B)-(C)] is 5,000 or greater; (iv) The mass-average molecular weight of component (C) is 30,000 or less.

[0085] Examples of preferred combinations of component (B) and component (C) include the following: • Combination of PAG1 (component (B)) and PAG10 (component (C)) from the example. • Combination of PAG1 (component (B)) and PAG5 (component (C)) from the example. • Combination of PAG1 (component (B)) from the example and PAG11 (component (C)) from the example • Combination of PAG1 (component (B)) and PAG12 (component (C)) from the example.

[0086] The aqueous heat treatment fluid composition according to one aspect of this disclosure may contain, in addition to the above-described components (B) and (C), other components to the extent that they do not impair the effects of this embodiment. Examples of other components include third polyalkylene glycols that do not fall under either component (B) or component (C); additives, etc.

[0087] <Additive (D)> In addition to the components described above, an aqueous heat treatment fluid composition according to one aspect of this disclosure may contain an additive (D) to the extent that it does not impair the effects of this embodiment. Examples of additive (D) include metal deactivators, defoamers, disinfectants, rust inhibitors, antioxidants, and anti-emulsifiers, and one or more of these may be used.

[0088] (metal deactivator) Examples of metal deactivators include benzotriazole, imidazoline, pyrimidine derivatives, and thiadiazole, sodium phosphate salts, and phosphate ester derivatives.

[0089] (Antioxidant) Examples of antioxidants include 2,6-ditert-butyl-p-cresol.

[0090] (Preservatives, defoamers, rust inhibitors) Examples of preservatives include diglycolamine, N-methyldicyclohexylamine, 2-amino-2-methyl-1-propanol, N-methyldiethanolamine, cyclohexyldiethanolamine, triethanolamine, 2-(methylamino)ethanol, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, and monobutylethanolamine.

[0091] Examples of defoaming agents include silicone compounds and polyether compounds.

[0092] Examples of rust inhibitors include dotecandioic acid and neodecanoic acid.

[0093] (Antiemulsifier) Examples of anti-emulsifiers include cationic surfactants.

[0094] Additive (D) may be used alone or in combination of two or more types.

[0095] <Content of each ingredient> (Content of ingredient (A)) The content of component (A) relative to the total amount of the aqueous heat treatment solution composition according to one aspect of this disclosure is not particularly limited. Since the aqueous heat treatment solution composition according to one aspect of this disclosure is sold in a form with a low water content (in the form of a concentrated solution) and can be used by the user after diluting it to the desired concentration, the content of component (A) in the aqueous heat treatment solution composition may change during distribution and use.

[0096] The case in which the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a diluent will be described. In this case, the content of component (A) in the aqueous heat treatment liquid composition is set appropriately from the viewpoint of sufficiently obtaining the cooling rate suppression effect of component (B); from the viewpoint of sufficiently obtaining the durability improvement effect of component (C); and so on.

[0097] For example, the content of component (A) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of the present disclosure is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more. Furthermore, for example, the content of component (A) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 98% by mass or less, more preferably 96% by mass or less, and even more preferably 94% by mass or less, from the viewpoint of good cooling suppression and durability. The upper and lower limits of these numerical ranges may be combined in any way. For example, the content of component (A) relative to the total amount of the aqueous heat treatment liquid composition according to one embodiment of this disclosure, when in the form of a diluted solution, is preferably 30% to 98% by mass, more preferably 35% to 96% by mass, and even more preferably 40% to 94% by mass.

[0098] Next, we will describe the case in which the aqueous heat treatment fluid composition according to one aspect of this disclosure is in the form of a concentrated liquid. In this case, the content of component (A) in the aqueous heat treatment fluid composition according to one aspect of this disclosure is set appropriately from the viewpoint of reducing fire risk and enhancing safety; from the viewpoint of transportation costs; from the viewpoint of concentration handling at the site of use (high degree of freedom to change the concentration range); and from the viewpoint of ensuring sufficient content of components (B) and (C).

[0099] While a lower water content is preferable from the viewpoint of ease of concentration handling at the site of use (higher degree of freedom to change the concentration range), from the viewpoint of reducing fire risk, for example, the content of component (A) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one embodiment of this disclosure is preferably 10% by mass or more, and more preferably 15% by mass or more, 20% by mass or more, or 30% by mass or more. Furthermore, for example, the content of component (A) relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, from the viewpoint of active ingredient concentration. The upper and lower limits of these numerical ranges may be combined in any way. For example, the content of component (A) in relation to the total amount of the aqueous heat treatment liquid composition according to one embodiment of the present disclosure, when in the form of a concentrated liquid, is preferably 10% to 85% by mass, more preferably 15% to 80% by mass, even more preferably 20% to 75% by mass, and even more preferably 30% to 75% by mass.

[0100] (Content of ingredient (B)) The content of component (B) in the total amount of 100% by mass of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.7% by mass or more, more preferably 0.9% by mass or more, and even more preferably 1.8% by mass or more, from the viewpoint of enhancing the effect of suppressing the cooling rate. Furthermore, from the viewpoint of improving handling properties, the content of component (B) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. The upper and lower limits of these numerical ranges may be combined in any way. For example, the content of component (B) relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.7% to 50% by mass, more preferably 0.9% to 45% by mass, and even more preferably 1.8% to 40% by mass.

[0101] (Content of ingredient (C)) From the viewpoint of enhancing the durability improvement effect, the content of component (C) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.025% by mass or more, more preferably 0.035% by mass or more, and even more preferably 0.05% by mass or more. Furthermore, the content of component (C) relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, taking into consideration the solubility of component (C) in water and the effect of component (B) on the cooling rate suppression effect. The upper and lower limits of these numerical ranges may be combined in any way. For example, the content of component (C) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one embodiment of the present disclosure, when in the form of a diluted solution, is preferably 0.025% by mass to 5% by mass, more preferably 0.035% by mass to 4% by mass, and even more preferably 0.05% by mass to 3% by mass.

[0102] (Content of ingredient (B) and ingredient (C)) In an aqueous heat treatment liquid composition according to one aspect of this disclosure, it is preferable that the content of component (B) is greater than the content of component (C).

[0103] In an aqueous heat treatment fluid composition according to one aspect of the present disclosure, for example, the content of component (B) is preferably 65% ​​by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, when the total amount of components (B) and (C) is 100% by mass, from the viewpoint of enhancing the effect of suppressing the cooling rate. Furthermore, when the total amount of components (B) and (C) is taken as 100% by mass, the content of component (B) is preferably 99.3% by mass or less, more preferably 95% by mass or less, and even more preferably 91% by mass or less, from the viewpoint of exhibiting durability. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, in the case of a concentrated liquid, the content of component (B) is preferably 65% ​​to 99.3% by mass, more preferably 75% to 95% by mass, and even more preferably 80% to 91% by mass, when the total amount of components (B) and (C) is 100% by mass.

[0104] Furthermore, for example, from the viewpoint of enhancing the durability-improving effect, the content of component (C) is preferably 0.7% by mass or more, more preferably 5% by mass or more, and even more preferably 9% by mass or more, when the total amount of components (B) and (C) is 100% by mass. Furthermore, when the total amount of components (B) and (C) is taken as 100% by mass, the content of component (C) is preferably 35% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of exhibiting durability. The upper and lower limits of these numerical ranges may be combined in any way. For example, in the case of a concentrated liquid, the content of component (C) is preferably 0.7% to 35% by mass, more preferably 5% to 25% by mass, and even more preferably 9% to 20% by mass, when the total amount of components (B) and (C) is 100% by mass.

[0105] (Content of ingredient (D)) The content of component (D) in the aqueous heat treatment liquid composition according to one aspect of this disclosure can be appropriately determined within a range that does not hinder the effects of this embodiment and that allows the effects of component (D) to be exerted.

[0106] When the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a diluent, the content of component (D) is not particularly limited, but is preferably 0.01 to 12% by mass, more preferably 0.05 to 10% by mass, and even more preferably 0.1 to 7.5% by mass, based on 100% by mass of the total amount of the aqueous heat treatment liquid composition.

[0107] Furthermore, the content of component (D) when the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a concentrated liquid is not particularly limited. The content of component (D) relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition can be determined according to the concentration ratio of the concentrated liquid so that the content of component (D) when diluted falls within the range described above. For example, the content of component (D) is preferably 0.1 to 25% by mass, more preferably 0.5 to 15% by mass, and even more preferably 1 to 10% by mass, relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition. If the aqueous heat treatment liquid composition according to one aspect of this disclosure contains multiple components as component (D), each component shall be contained independently within the above range.

[0108] <Example of preferred formulation> An aqueous heat treatment liquid composition according to one embodiment of the present disclosure, when the total amount of the aqueous heat treatment liquid composition is 100% by mass, The aforementioned component (B) is 0.7% by mass or more and 50% by mass or less, The aforementioned component (C) is 0.025% by mass or more and 5% by mass or less, It is preferable that it includes.

[0109] Furthermore, in another embodiment of the present disclosure, when the total amount of the aqueous heat treatment liquid composition is 100% by mass, The aforementioned component (B) is 0.9% by mass or more and 45% by mass or less, The aforementioned component (C) is 0.035% by mass or more and 4% by mass or less, It is preferable that it includes.

[0110] Furthermore, in another embodiment of the present disclosure, when the total amount of the aqueous heat treatment liquid composition is 100% by mass, The aforementioned component (B) is 1.8% by mass or more and 40% by mass or less, The aforementioned component (C) is 0.05% by mass or more and 3% by mass or less, It is preferable that it includes.

[0111] <Properties of aqueous heat treatment solution compositions> (durability) A water-based heat treatment fluid composition according to one aspect of this disclosure is preferable to a water-based heat treatment fluid composition that does not contain component (C) in which the cooling rate changes less even when the composition is repeatedly used in heat treatment. For example, the 350-150°C cooling rate change rate (%) obtained from the durability test described in the examples below is preferably 25% or less, more preferably 20% or less, and even more preferably 15%. A water-based heat treatment fluid composition having a 350-150°C cooling rate change rate (%) of 25% or less can be said to have good durability against repeated use.

[0112] (cooling rate) The aqueous heat treatment fluid composition according to one aspect of this disclosure preferably exhibits a suppressed (slower) cooling rate compared to an aqueous heat treatment fluid composition that does not contain component (B). The degree to which the cooling rate of the aqueous heat treatment fluid composition according to one aspect of this disclosure is suppressed is not particularly limited.

[0113] The cooling rate of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably, for example, 450°C / s or less, and more preferably 400°C / s or less, between 350°C and 150°C. Furthermore, there are no particular limitations on the lower limit of the 350-150°C cooling rate using the aqueous heat treatment liquid composition according to one aspect of this disclosure, but for example, it is 30°C / s or higher. The upper and lower limits of these numerical ranges may be combined in any way; for example, the 350-150°C cooling rate of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 30°C / s to 450°C / s, and more preferably 30°C / s to 400°C / s.

[0114] <Form of aqueous heat treatment liquid composition> The aqueous heat treatment fluid composition according to one aspect of this disclosure may be prepared by blending the above-mentioned components at the desired concentration at the time of use from the beginning, or a concentrated solution (stock solution) may be prepared first and then diluted with water to the desired concentration at the time of use. The aqueous heat treatment fluid composition according to one aspect of this disclosure also has good storage stability in the form of a concentrated solution. For this reason, considering the reduction of transportation costs and the ability to adjust the cooling performance by dilution concentration, the aqueous heat treatment fluid composition according to one aspect of this disclosure is preferably in the form of a concentrated solution.

[0115] As a concentrated aqueous heat treatment liquid composition according to one aspect of this disclosure, from the viewpoint of ease of handling, the aqueous heat treatment liquid composition is concentrated by a volume ratio of preferably 2 to 20 times, more preferably 2.5 to 15 times, and even more preferably 3 to 10 times.

[0116] <Uses of aqueous heat treatment liquid compositions> An aqueous heat treatment fluid composition according to one aspect of this disclosure can be used as a coolant for heat treatment of metallic materials. The type of heat treatment of the metallic material is not particularly limited. The aqueous heat treatment fluid composition according to one aspect of this disclosure may be an aqueous heat treatment fluid composition for quenching or an aqueous heat treatment fluid composition for tempering.

[0117] <Method for producing an aqueous heat treatment liquid composition> An aqueous heat treatment fluid composition according to one aspect of this disclosure can be manufactured by mixing the above-described components. The mixing method is not particularly limited as long as the components can be mixed uniformly.

[0118] [2. Methods for manufacturing metal materials] A method for manufacturing a metallic material according to one aspect of the present disclosure includes a heat treatment step for the metallic material, wherein an aqueous heat treatment liquid composition according to one aspect of the present disclosure is used as a coolant for cooling the heated metallic material in the heat treatment step.

[0119] According to a method for manufacturing a metal material according to one aspect of this disclosure, since an aqueous heat treatment liquid composition according to one aspect of this disclosure is used as a coolant to cool the heated metal material in the heat treatment process, it is possible to manufacture a metal material that suppresses distortion and quench cracking even after repeated use.

[0120] In a method for manufacturing a metal material according to one aspect of the present invention, the specific type of metal material to be manufactured is not particularly limited.

[0121] The type of heat treatment step for a metal material included in a method for manufacturing a metal material according to one aspect of this disclosure is not limited. Examples of the heat treatment step include a quenching step and a tempering step. In a method for manufacturing a metal material according to one aspect of this disclosure, an aqueous heat treatment liquid composition according to one aspect of this disclosure is used in the heat treatment step. The method for manufacturing a metal material according to one aspect of this disclosure may include only a quenching step, only a tempering step, or both a quenching step and a tempering step as the heat treatment step. If the method for manufacturing a metal material according to one aspect of this disclosure includes both a quenching step and a tempering step as the heat treatment step, the tempering step may be included after the quenching step. If the method for manufacturing a metal material according to one aspect of this disclosure includes a tempering step after the quenching step, it is preferable to use the aqueous heat treatment liquid composition according to one aspect of this disclosure as a coolant to cool the metal material after tempering in the tempering step.

[0122] In the heat treatment process, the method of heating the metal material is not particularly limited, and conventionally known heating methods such as high-frequency induction hardening and carburizing can be used. Furthermore, in the quenching process, the cooling method using the aqueous heat treatment liquid composition is not particularly limited, and cooling methods employed in conventionally known quenching methods can also be employed in this embodiment. For example, an immersion method may be employed in which the heated metal material is immersed in the aqueous heat treatment liquid composition according to one aspect of this disclosure described above to cool it, or an injection method may be employed in which the aqueous heat treatment liquid composition according to one aspect of this disclosure described above is sprayed onto the heated metal material to cool it.

[0123] A method for manufacturing a metallic material according to one aspect of this disclosure may further include steps other than the heat treatment step.

[0124] [3. Manufacturing equipment for metal materials] A metal material manufacturing apparatus according to one aspect of the present disclosure is a metal material manufacturing apparatus that performs at least a heat treatment step for a metal material, wherein in the heat treatment step, an aqueous heat treatment liquid composition according to one aspect of the present disclosure is used as a coolant to cool the heated metal material.

[0125] According to a metal material manufacturing apparatus according to one aspect of this disclosure, since an aqueous heat treatment liquid composition according to one aspect of this disclosure is used as a coolant to cool the heated metal material in the heat treatment process, it is possible to manufacture a metal material that suppresses distortion and quench cracking even after repeated use.

[0126] In a metal material manufacturing apparatus according to one aspect of the present invention, the specific type of metal material to be manufactured is not particularly limited.

[0127] The type of heat treatment process for a metal material carried out in a metal material manufacturing apparatus according to one aspect of this disclosure is not limited. Examples of such heat treatment processes include quenching and tempering. In the metal material manufacturing apparatus according to one aspect of this disclosure, an aqueous heat treatment liquid composition according to one aspect of this disclosure is used in the heat treatment process. The metal material manufacturing apparatus according to one aspect of this disclosure may carry out only a quenching process, only a tempering process, or both a quenching and tempering process as the heat treatment process. When the metal material manufacturing apparatus according to one aspect of this disclosure carries out both a quenching and tempering process as the heat treatment process, the tempering process may be carried out after the quenching process. When the metal material manufacturing apparatus according to one aspect of this disclosure includes a tempering process after the quenching process, it is preferable to use the aqueous heat treatment liquid composition according to one aspect of this disclosure as a coolant for cooling the metal material after tempering in the tempering process.

[0128] A manufacturing apparatus for a metallic material according to one aspect of this disclosure comprises at least a heat treatment apparatus for performing a heat treatment process on the metallic material. The specific configuration of the heat treatment apparatus is not particularly limited. Depending on the type of heating and cooling method used in the heat treatment process to be performed (e.g., quenching process, tempering process), the heat treatment apparatus may be equipped with a mechanism capable of performing these methods. The heating and cooling methods in the heat treatment process are as described in the manufacturing method for a metallic material according to one aspect of this disclosure.

[0129] A metal material manufacturing apparatus according to one aspect of this disclosure may further include components other than a heat treatment apparatus.

[0130] 〔summary〕 The aqueous heat treatment liquid composition according to Embodiment 1 of the present disclosure contains water (A), polyalkylene glycols (B) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and compound (C), wherein the cloud point of compound (C) is 10°C or higher, and the cloud point of compound (C) is 10°C or lower than the cloud point of polyalkylene glycols (B).

[0131] In the aqueous heat treatment liquid composition according to Embodiment 2 of this disclosure, in Embodiment 1 above, the ratio (P1:Q1) of the number of moles of ethylene oxide units added (P1) to the number of moles of alkylene oxide units other than ethylene oxide (Q1) in the molecule of the polyalkylene glycol (B) is preferably 50:50 to 91:9.

[0132] The aqueous heat treatment liquid composition according to aspect 3 of the present disclosure may have a configuration in which, when the total amount of the polyalkylene glycols (B) and the compound (C) is set to 100% by mass, the polyalkylene glycols (B) are contained in an amount of 65% by mass or more and 99.3% by mass or less, and the compound (C) is contained in an amount of 0.7% by mass or more and 35% by mass or less.

[0133] The aqueous heat treatment liquid composition according to aspect 4 of the present disclosure may have a configuration in any one of aspects 1 to 3 above, where the total amount of the aqueous heat treatment liquid composition is 100% by mass, and the polyalkylene glycols (B) are 0.7% by mass or more and 50% by mass or less, and the compound (C) is 0.025% by mass or more and 5% by mass or less.

[0134] In the aqueous heat treatment liquid composition according to aspect 5 of this disclosure, it is preferable that the compound (C) is a second polyalkylene glycol (C1) in any one of the above aspects 1 to 4.

[0135] In the aqueous heat treatment liquid composition according to aspect 6 of the present disclosure, it is preferable that, in aspect 5 above, the mass-average molecular weight of the second polyalkylene glycol (C1) is smaller than the mass-average molecular weight of the polyalkylene glycol (B), and the difference between the mass-average molecular weight of the polyalkylene glycol (B) and the mass-average molecular weight of the second polyalkylene glycol (C1) is 5,000 or more.

[0136] In the aqueous heat treatment liquid composition according to aspect 7 of this disclosure, in aspect 5 or 6 above, it is preferable that the ratio (P2:Q2) of the number of moles of ethylene oxide units added (P2) to the number of moles of alkylene oxide units other than ethylene oxide (Q2) in the molecule of the second polyalkylene glycol (C1) is 0:100 to 100:0.

[0137] In any of embodiments 5 to 7 above, the aqueous heat treatment liquid composition according to aspect 8 of this disclosure may be configured such that the cloud point of the second polyalkylene glycol (C1) is 20°C or more lower than the cloud point of the polyalkylene glycol (B).

[0138] The aqueous heat treatment fluid composition according to aspect 9 of this disclosure may be configured for quenching in any of the above aspects 1 to 8.

[0139] A method for manufacturing a metal material according to aspect 10 of the present disclosure includes a heat treatment step for the metal material, wherein the aqueous heat treatment liquid composition described in any one of aspects 1 to 9 above is used as a coolant for cooling the heated metal material in the heat treatment step.

[0140] A metal material manufacturing apparatus according to aspect 11 of the present disclosure is a metal material manufacturing apparatus that performs at least a heat treatment step for a metal material, wherein, in the heat treatment step, the aqueous heat treatment liquid composition described in any one of aspects 1 to 9 above is used as a coolant for cooling the heated metal material.

[0141] The present disclosure is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical means respectively disclosed in the embodiments are also included in the technical scope of the present disclosure. [Examples]

[0142] Hereinafter, the present invention will be described in more detail with reference to working examples and comparative examples, but the present invention is not limited to these examples. [Test Example 1] 1. Materials The following materials were used for the aqueous heat treatment liquid compositions of the examples and comparative examples. <Water (A): Component (A)> • Tap water <Polyalkylene glycols containing repeating units derived from EO and repeating units derived from PO (B): Component (B)> • Linear polyalkylene glycol 1 containing EO units and PO units (PAG1) <Candidate compounds for compound (C): Component (C)> <<Second polyalkylene glycols (C1)>> (1) Linear PAG • Linear polyalkylene glycol 2 containing EO units and PO units (PAG2) • Linear polyalkylene glycol 3 containing EO units and PO units (PAG3) • Linear polyalkylene glycol 5 containing EO units and PO units (PAG5) • Linear polyalkylene glycol 6 containing EO units and PO units (PAG6) • Linear polyalkylene glycol 7 containing EO units and PO units (PAG7) • Linear polyalkylene glycol 8 containing EO units and PO units (PAG8) • Linear polyalkylene glycol 9 containing EO units and PO units (PAG9) • Linear polyalkylene glycol 10 containing EO units and PO units (PAG10) (2) Branched PAG • Mixed adduct of glycerin EO and PO (PAG4) (3) Ethylenediamine adducts • Ethylenediamine polyoxyethylene polyoxypropylene block polymer 1 (PAG11) • Polyoxyethylene polyoxypropylene block polymer 2 (PAG12) of ethylenediamine (4) Linear PAG derivatives (methyl terminate) • Polyoxyalkylene alkyl ether (PAG13) Polyglyceryl ether (C2) • Polyglyceryl ether (PGE1) <<Other ingredients>> • Polyglycerin (PG1) • Polyethylene glycol (PEO1)

[0143] <Other ingredients> Dodecane dioic acid • Diglycolamine

[0144] Detailed information, such as the structure of the substances used as component (B) and component (C), is shown in Table 3. Table 4 shows the numerical values ​​of the cloud point difference between component (B) and component (C), and the numerical values ​​of the molecular weight difference between component (B) and component (C).

[0145] [Table 3]

[0146] [Table 4]

[0147] 2. Preparation The aqueous heat treatment fluid compositions (stock solutions) for Examples 1-9 and Comparative Examples 1-7 were prepared using the formulations and proportions shown in Tables 5-6. In all of the aqueous heat treatment fluid compositions (stock solutions) for Examples 1-9 and Comparative Examples 1-7, the content of component (B) was 94.3% by mass and the content of component (C) was 5.7% by mass, with the total amount of component (B) and component (C) being 100% by mass.

[0148] [Table 5]

[0149] [Table 6]

[0150] 3. Exam Each aqueous heat treatment solution composition (stock solution) of the Examples and Comparative Examples was diluted with water (A) to a concentration of 20% to prepare the diluted solutions used in the following tests. Note that the aqueous heat treatment solution composition (stock solution) of Comparative Example 2 separated into upper layers in about one week, and the diluted solution also separated into layers, so the following evaluation was not performed. This was thought to be because the cloud point of component (C) added to the aqueous heat treatment solution composition of Comparative Example 2 was less than 25°C, causing separation at room temperature. In addition, although the aqueous heat treatment solution composition of Comparative Example 3 separated into layers in the stock solution, it did not separate into layers in the diluted state, so it was subjected to the tests described later. No layer separation was observed in the aqueous heat treatment solution compositions of the other Examples and Comparative Examples, whether in the stock solution or the diluted state, indicating good solubility of component (C) in water.

[0151] 3-1. Cooling performance test Cooling curves were obtained for aqueous heat treatment fluid compositions obtained at a liquid temperature of 30°C, in accordance with the cooling performance test specified in JIS K2242:2012:Annex A (Method B: Core temperature measurement method). (1) Characteristic seconds From the aforementioned cooling curve, the time (characteristic seconds) required to reach the characteristic temperature (the temperature at which the above film-making process is completed) was obtained. (2) Cooling rate In the aforementioned cooling curve, the cooling rate from 350°C to 150°C (350-150°C cooling rate (°C / s)) was calculated.

[0152] 3-2. Durability Test (Induction Heating Degradation Test) (1) Cooling rate and characteristic time in seconds First, the cooling performance evaluation described in 3-1 above was performed, and this was taken as the result before the induction tacit degradation test (when the oil was new). Next, induction heating degradation tests were performed using the aqueous heat treatment fluid compositions of the examples and comparative examples under the conditions shown below. After the degradation test, the cooling performance evaluation described in 3-1 above was performed again, and this was taken as the result after the induction heating degradation test (after degradation). Test conditions Test piece: SUS304 (φ25×50mm) Hardening temperature: 850℃ (25kHz induction heating) Oil amount: 400ml Oil temperature: 30℃ Stirring: 200 rpm Nitrogen injection: 200 ml / min Heat treatment time: 5 minutes Number of heat treatments: 100 times The rate of change in cooling rate between 350°C and 150°C (hereinafter referred to as "rate of change in cooling rate") was calculated using the following formula. Cooling rate change rate (%) = [(Value after degradation / Value when oil is present) - 1] × 100 Furthermore, the change in cooling rate between 350°C and 150°C (hereinafter referred to as "change in cooling rate") was calculated using the following formula. Cooling rate change [°C / sec] = Value after degradation - Value when new oil is used

[0153] (2) Sugar content The sugar content was measured using a Brix refractometer.

[0154] (3)Kinematic viscosity at 40℃ The kinematic viscosity at 40°C was measured using a modified Ostwald-type Cannon-Fenske viscometer in accordance with the method described in JIS K2282. The rate of change in kinematic viscosity at 40°C was calculated using the following formula. Change in kinematic viscosity at 40°C (%) = [(Value after degradation / Value when oil is lipophilic) - 1] × 100

[0155] 4.Results The evaluation results are shown in Tables 7-11.

[0156] [Table 7]

[0157] [Table 8]

[0158] [Table 9]

[0159] [Table 10]

[0160] [Table 11]

[0161] Examples 2 and 3 and Comparative Examples 1, 6 and 7 were selected as representative examples from the examples and comparative examples. The relationship between the rate of change in kinematic viscosity at 40°C and the change in cooling rate of each aqueous heat treatment fluid composition, and the cloud point of component (C) in each aqueous heat treatment fluid composition is shown in the graph.

[0162] Furthermore, as representative examples from the examples and comparative examples, Examples 1 to 5 and Comparative Examples 1, 3, 6, and 7 were selected, and the relationship between the rate of change in the cooling rate of each aqueous heat treatment liquid composition and the cloud point of component (C) in each aqueous heat treatment liquid composition is shown in a graph.

[0163] The results are shown in Figures 1 and 2. Figure 1 shows the relationship between the rate of change in kinematic viscosity at 40°C or the change in cooling rate of each aqueous heat treatment fluid composition and the cloud point of component (C). Figure 2 shows the relationship between the rate of change in cooling rate of each aqueous heat treatment fluid composition and the cloud point of component (C).

[0164] As shown in Figures 1 and 2, a correlation was found between the rate of change in cooling rate and the cloud point of component (C).

[0165] Therefore, we decided to evaluate durability using the rate of change in cooling rate as an indicator. Specifically, the rate of change in cooling rate of each aqueous heat treatment fluid composition was compared with the rate of change in cooling rate of Comparative Example 1 (reference value), and the results were evaluated in the following three stages. A: The rate of change in cooling rate is extremely low compared to the reference value (rate of change in cooling rate is 25% or less). B: Cooling rate change rate is equivalent to or slightly lower than the reference value. C: Cooling rate change rate is higher than the reference value.

[0166] A result of "A" in the evaluation of the rate of change in cooling rate was evaluated as good durability, a result of "B" was evaluated as moderately good durability, and a result of "B" was evaluated as poor durability. The evaluation results of the durability of each aqueous heat treatment fluid composition are shown in Tables 7 to 11.

[0167] The results shown in Tables 7-11 indicate that the aqueous heat treatment fluid composition of the Examples showed a suppressed cooling rate of 350-150°C compared to the aqueous heat treatment fluid composition of Comparative Example 1, which did not contain component (C). Furthermore, it was found that the aqueous heat treatment fluid composition of the Examples has good durability and exhibits little change in cooling rate even after repeated use, due to the presence of component (C), which has a cloud point of 10°C or higher and a cloud point at least 10°C lower than that of component (B). [Industrial applicability]

[0168] A water-based heat treatment fluid composition according to one aspect of this disclosure can be used as a quenching or tempering fluid for metal materials.

Claims

1. The material contains water (A), polyalkylene glycols (B) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and a compound (C). The cloud point of the compound (C) is 10°C or higher, The cloud point of compound (C) is 10°C or more lower than the cloud point of polyalkylene glycols (B). A water-based heat treatment liquid composition characterized by the following features.

2. The number of moles of ethylene oxide units added in the molecule of the polyalkylene glycols (B) (P １ ) and the number of moles of alkylene oxide units other than ethylene oxide (Q １ ) ratio (P １ : Q １ The aqueous heat treatment liquid composition according to claim 1, wherein the ratio of ) is 50:50 to 91:

9.

3. When the total amount of the polyalkylene glycols (B) and the compound (C) is 100% by mass, The above polyalkylene glycols (B) are contained in an amount of 65% by mass or more and 99.3% by mass or less, and The aqueous heat treatment liquid composition according to claim 1 or 2, comprising 0.7% by mass or more and 35% by mass or less of the compound (C).

4. When the total amount of the aqueous heat treatment fluid composition is 100% by mass, The polyalkylene glycols (B) are present in an amount of 0.7% by mass or more and 50% by mass or less. The aforementioned compound (C) is present in an amount of 0.025% by mass or more and 5% by mass or less. An aqueous heat treatment liquid composition according to any one of claims 1 to 3, comprising the above.

5. The aqueous heat treatment liquid composition according to any one of claims 1 to 4, wherein the compound (C) is a second polyalkylene glycol (C1).

6. The mass-average molecular weight of the second polyalkylene glycol (C1) is smaller than the mass-average molecular weight of the polyalkylene glycol (B), and The aqueous heat treatment liquid composition according to claim 5, wherein the difference between the mass-average molecular weight of the polyalkylene glycol (B) and the mass-average molecular weight of the second polyalkylene glycol (C1) is 5,000 or more.

7. The number of moles of ethylene oxide units added in the molecule of the second polyalkylene glycol (C1) (P ２ ) and the number of moles of alkylene oxide units other than ethylene oxide (Q ２ ) ratio (P ２ : Q ２ The aqueous heat treatment liquid composition according to claim 5 or 6, wherein the ratio of ) is 0:100 to 100:

0.

8. The aqueous heat treatment liquid composition according to any one of claims 5 to 7, wherein the cloud point of the second polyalkylene glycol (C1) is 20°C or more lower than the cloud point of the polyalkylene glycol (B).

9. A water-based heat treatment liquid composition according to any one of claims 1 to 8, characterized in that it is for quenching.

10. This includes a heat treatment process for metal materials. A method for producing a metal material, wherein in the heat treatment step, the aqueous heat treatment liquid composition described in any one of claims 1 to 9 is used as a coolant for cooling the heated metal material.

11. A manufacturing apparatus for metal materials that performs at least a heat treatment process for metal materials, A metal material manufacturing apparatus that uses the aqueous heat treatment liquid composition described in any one of claims 1 to 9 as a coolant for cooling the heated metal material in the heat treatment process.

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