Coolant for die for plastic working

Abstract

To provide a novel cooling agent useful for a plasticity processing die.SOLUTION: A cooling agent for a plasticity processing die is a liquid in which the following components A, B are dispersed in water, a water-miscible organic solvent, or a mixture of the two. The component A is one or more silicate-containing minerals, the component B is one or more compounds selected from a group consisting of aliphatic carboxylic acids and salts thereof, aliphatic hydroxy acids and salts thereof, aromatic carboxylic acids and salts thereof, and aromatic hydroxy acids and salts thereof, and a compound has 12 to 22 carbon atoms.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a coolant for plastic working dies.

Background Art

[0002] When manufacturing plastic processed products using dies, the dies may become hot. When the dies are exposed to high temperatures, they suffer from thermal degradation, resulting in a problem of shortened die life. From the viewpoints of improving the production efficiency of plastic processed products and reducing production costs, it is desirable to prevent the thermal degradation of the dies. Therefore, a method of cooling the dies using a coolant has been conventionally proposed. For example, Patent Document 1 discloses a method of injecting a coolant onto the inner surface of a die of a hot press device. As the coolant, cooling water is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a novel coolant useful for plastic working dies.

Means for Solving the Problems

[0005] As a result of intensive studies to solve the above problems, the present inventors have found that a coolant containing a silicate-containing mineral and a hydrocarbon compound having a predetermined carboxy group has an excellent cooling effect on plastic working dies, and have completed the present invention.

[0006] The present invention is specifically specified as follows by way of example. [1] A coolant for plastic working dies containing the following Component A and Component B. Component A: one or more silicate-containing minerals; Component B: one or more compounds selected from the group consisting of aliphatic carboxylic acids and their salts, aliphatic hydroxy acids and their salts, aromatic carboxylic acids and their salts, and aromatic hydroxy acids and their salts.

Advantages of the Invention

[0007] The present invention can provide a novel coolant useful for molds for plastic processing. Therefore, the present invention is expected to contribute to improving the production efficiency and reducing the production cost of plastic processed products.

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention including a coolant for a mold for plastic processing will be described in detail. Note that the present invention can be arbitrarily changed without departing from the gist of the present invention and is not limited to the following embodiments.

[0009] In one embodiment, the coolant for a mold for plastic processing according to the present invention contains the following Component A and Component B. Thereby, an excellent cooling effect can be exhibited on the mold for composition processing. Component A: one or more silicate-containing minerals; Component B: one or more compounds selected from the group consisting of aliphatic carboxylic acids and their salts, aliphatic hydroxy acids and their salts, aromatic carboxylic acids and their salts, and aromatic hydroxy acids and their salts

[0010] <Component A> As Component A, one or more silicate-containing minerals are used. The silicate-containing mineral may be a natural mineral or a synthetic product. The silicate-containing mineral preferably contains aluminum oxide and / or magnesium oxide. Further, the silicate-containing mineral may be a hydrous mineral or a hydrate. The silicate-containing mineral is not particularly limited, and examples thereof include layered silicate-containing minerals and network-structured silicate-containing minerals.

[0011] The layered silicate-containing mineral is not particularly limited as long as SiO4 tetrahedrons are bonded in a planar manner. Examples include kaolinite, kaolin, halloysite, antigorite, monoclinic chrysotile, orthorhombic chrysotile, lizardite, nickel silicate, bentonite, montmorillonite, hectorite, pyrophyllite, talc, mica (muscovite, sericite, phlogopite, iron mica, biotite, trilicic mica, polilicic mica, lithium mica, tschermigite, margarite, etc.), illite, glauconite, (clinocloisite, stilpnomelane, etc.), magnesian vermiculite, gaylussite, okenite, prehnite, fluorapophyllite, hydroxylapophyllite, chrysocolla, and other phyllosilicate minerals.

[0012] The network-structured silicate-containing minerals are not particularly limited as long as the SiO4 tetrahedrons are bonded in a network structure. For example, feldspars such as orthoclase, sanidine, microcline, anorthoclase, labradorite, ash alluvium, petalite, etc.; feldspathoids such as kaliophilite, leucite, nepheline, sodalite, haüyne, lapis lazuli, nosean, etc.; columnar minerals such as wollastonite, pectolite, etc.; zeolites such as amicite, analcime, barrel zeolite, belvite, bikitaite, boggsite, strontium brewsterite, barium brewsterite, gray chabazite, soda chabazite, kali chabazite, chiavennaite, kali clinoptilolite, soda clinoptilolite, gray clinoptilolite, coulsonite, gray dachiardite, soda dachiardite, edingtonite, erionite, soda erionite, kali erionite, sodium forjasite, gray forjasite, magnesia forjasite, magnesia ferrierite, kali ferrierite, soda ferrierite, galloonite, goldstone, gismondine, soda gmelinite, gray gmelinite, kali gmelinite, gobbinsite, gonardite, goose creekite, gotardite, barium cross zeolite, gray stilbite, strontium stilbite, soda stilbite, kali stilbite, shanfaite, kali borosilite laumontite, gray levyne, soda levyne, lovdarite, maricopaite, massyite, merlinoite, mesolite, montesommaite, mordenite, mutinaite, soda zeolite, offretite, pahasapaite, palteite, sodium pollingite, kali pollingite, calcium pollingite, perialite, soda cross zeolite, kali cross zeolite, gray cross zeolite, porkusite, lodgianite, scorellite, stellaite, gray scolecite, soda scolecite, terranovaite, thomsonite, czarnikite, tscholtnerite, wirakeite, vinebeneite, wilhendersonite, yuwanite, leucite, ammonium leucite, inesite, dumbrisite, helvite, dainite and other tectosilicate minerals such as zeolites. The crystal structure of the zeolite may be any of A-type, X-type, beta-type, ZSM-5 type, ferrierite type, mordenite type, L-type, Y-type. The silicate-containing mineral may be used alone or in combination of two or more.

[0013] <Component B> As component B, one or more compounds selected from the group consisting of aliphatic carboxylic acids and their salts, aliphatic hydroxy acids and their salts, aromatic carboxylic acids and their salts, and aromatic hydroxy acids and their salts are used.

[0014] Although the aliphatic carboxylic acids and aliphatic hydroxy acids are not particularly limited, for example, aliphatic carboxylic acids and aliphatic hydroxy acids having 7 to 30 carbon atoms can be used, aliphatic carboxylic acids and aliphatic hydroxy acids having 8 to 28 carbon atoms are preferably used, and aliphatic carboxylic acids and aliphatic hydroxy acids having 12 to 22 carbon atoms are more preferably used.

[0015] The aliphatic carboxylic acid means a compound in which one or more hydrogen atoms in the hydrocarbon are substituted with a carboxyl group. The hydrocarbon may have one or more double bonds or triple bonds. The carbon atoms in the aliphatic carboxylic acid may be linked linearly, branched, and / or cyclically, but are preferably linked linearly. The ring formed by cyclic linkage may be, for example, a 3-membered ring, 4-membered ring, 5-membered ring, 6-membered ring, etc., but is not limited thereto. The ring is not particularly limited as long as it is a non-aromatic ring, and may be a saturated ring or an unsaturated ring. One kind of aliphatic carboxylic acid may be used, or two or more kinds may be used in combination.

[0016] Examples of aliphatic carboxylic acids include butyric acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, octacosanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, isopalmitic acid, isostearic acid, cyclohexanoic acid, 4-methylcyclohexanecarboxylic acid, carboxymethylcyclohexane, 2-(carboxymethyl)cyclohexylacrylic acid, 9-tetradecenoic acid, 2-hexadecenoic acid, 9-hexadecenoic acid, 9-octadecenoic acid, 9,12-octadecadienoic acid, 6,9,12-octadecatrienoic acid, γ-linolenic acid, arachidonic acid, dihomo-γ-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid, etc.

[0017] Aliphatic hydroxy acids refer to compounds in which one or more hydrogen atoms in the hydrocarbon of the above-mentioned aliphatic carboxylic acids are replaced by hydroxyl groups. Examples of aliphatic hydroxy acids include 2-hydroxymyristic acid, 3-hydroxymyristic acid, 2-hydroxypalmitic acid, 12-hydroxystearic acid, 2-hydroxyicosanoic acid, 3-hydroxy-3-methylhexanoic acid, 4-hydroxycyclohexanecarboxylic acid, 3-hydroxy-4-methylcyclohexane-1-carboxylic acid, etc. One kind of aliphatic hydroxy acid may be used, or two or more kinds may be used in combination.

[0018] Aromatic carboxylic acids and aromatic hydroxy acids are not particularly limited. For example, aromatic carboxylic acids and aromatic hydroxy acids having 7 to 30 carbon atoms can be used, preferably those having 8 to 28 carbon atoms, and more preferably those having 12 to 22 carbon atoms.

[0019] An aromatic carboxylic acid means a compound in which one or more hydrogen atoms in a hydrocarbon compound having an aromatic ring are substituted with carboxyl groups. The aromatic ring may be either monocyclic or polycyclic with two or more rings. In the case of a polycyclic ring, it may have a condensed ring. The hydrocarbon may have one or more double bonds or triple bonds. The hydrocarbon bonded to the aromatic ring may be linear or branched. One kind of aromatic carboxylic acid may be used, or two or more kinds may be used in combination.

[0020] Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, terephthalic acid, 3-phenyl-2-propenoic acid, 4-methoxycinnamic acid, p-ethylbenzoic acid, 4-vinylbenzoic acid, and the like.

[0021] Aromatic hydroxy acids include compounds in which one or more hydrogen atoms in the above-described aromatic carboxylic acids are substituted with hydroxyl groups. Examples of aromatic hydroxy acids include monohydroxybenzoic acids (salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid), dihydroxybenzoic acids (such as 2-pyrocatechuic acid), trihydroxybenzoic acids (such as gallic acid), 4-methylsalicylic acid, caffeic acid, mandelic acid, 3-hydroxy-2-phenylpropanoic acid, hydroxycinnamic acid, 3,4-dihydroxycinnamic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, and the like. One kind of aromatic hydroxy acid may be used, or two or more kinds may be used in combination.

[0022] Examples of aliphatic carboxylates, aliphatic hydroxycarboxylates, aromatic carboxylates, and aromatic hydroxycarboxylates include the metal salts of the above-described aliphatic carboxylic acids, aliphatic hydroxyacids, aromatic carboxylic acids, and aromatic hydroxyacids, respectively. Examples of the metal salts include, but are not limited to, alkali metal salts (such as sodium salts, potassium salts, and lithium salts), alkaline earth metal salts (such as calcium salts and barium salts), magnesium salts, zinc salts, and aluminum salts. Other salts include salts of tin, iron, silver, antimony, manganese, and ammonium. These salts may be used alone or in combination of two or more.

[0023] The ratio of the total mass of component A to the total mass of component B in the coolant is preferably in the range of 1.0 or more and 35.5 or less, more preferably in the range of 2.0 or more and 26.0 or less, and even more preferably in the range of 3.0 or more and 15.0 or less.

[0024] <Solvent> In one embodiment, the coolant according to the present invention can be provided as a liquid in which component A and component B are dispersed in a solvent. The solvent can be water, but for example, ketone solvents such as acetone and methyl ethyl ketone; amide solvents such as N,N'-dimethylformamide and dimethylacetamide; alcohol solvents such as methanol, ethanol, and isopropanol; ether solvents such as ethylene glycol monobutyl ether and ethylene glycol monohexyl ether; pyrrolidone solvents such as 1-methyl-2-pyrrolidone and 1-ethyl-2-pyrrolidone; and other water-miscible organic solvents can also be used. When mixing a water-miscible organic solvent with water, there is no particular limitation as long as it is 50% by mass or less based on the total mass of the water-miscible organic solvent and water, and it may be 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less.

[0025] <Other Components> In one embodiment, the coolant according to the present invention may contain an additive in addition to component A, component B, and a solvent. As the additive, although not limited, for example, additives used in existing lubricants such as resin components, dispersants, surfactants, etc. can be added.

[0026] In addition, it is preferable that the coolant does not contain silica other than component A, component B, and the solvent. Therefore, in one embodiment of the coolant according to the present invention, the content concentration of silica is 0.4 mass% or less, preferably 0.2 mass% or less, more preferably 0.1 mass% or less, and most preferably 0 mass% with respect to 100 mass% of the coolant.

[0027] The coolant according to the present invention may be used as it is, or may be diluted with a solvent such as water and used. The dilution ratio of the coolant may be appropriately adjusted according to the object to be processed, the mold, and the method of contact of the coolant with the mold, etc., but for example, it can be in the range of 1.0 times or more and 15 times or less, and typically can be in the range of 1.2 times or more and 10 times or less.

[0028] <Method for manufacturing coolant> The coolant can be manufactured by mixing component A and component B in a solvent, and if necessary, a desired additive.

[0029] In this embodiment, the coolant is useful when plastic working a metal material. Specifically, by bringing the coolant into contact with the metal material to be plastically worked or the mold for plastic working, plastic working using the mold can be efficiently performed. Note that a film may be formed by bringing the coolant into contact with the metal material or the mold, or the state may be such that the liquid adheres. Here, the metal material is not particularly limited, and examples include metal materials such as iron, steel, alloy steel (e.g., stainless steel, chrome molybdenum steel, die steel), copper or copper alloy, aluminum or aluminum alloy, titanium or titanium alloy. The plastic working is not limited, and examples include forging, metal pressing, rolling, extrusion, wire drawing, drawing, squeezing, spinning, and bending. The method for manufacturing a plastic worked product according to the present invention can be suitably used for warm working and hot working in which the mold temperature tends to become high. The contact of the coolant with the metal material or the mold is not particularly limited, and examples thereof include the dipping method, the flow coating method, the spraying method, or a combination thereof.

Examples

[0030] Examples for better understanding of the present invention and its advantages are shown below together with comparative examples. However, the present invention is not limited by these examples.

[0031] (1. Preparation of coolant) As component A, the silicate-containing mineral or silica shown in Table 1 was used. As component B, various aliphatic carboxylic acids or their salts, salts of aliphatic hydroxy acids, and aromatic hydroxy acids shown in Table 1 were used.

[0032] Component A was added to water and stirred at 25°C for 30 minutes, and then component B was added and stirred further at 25°C for 1 hour to prepare the coolants of Examples 1 to 16 and Comparative Examples 1 to 5. The compositions of the respective coolants are as described in Tables 1 and 2.

[0033] (2. Mold cooling test) The following mold cooling test was performed on each of the coolants prepared above. <Test Conditions> · Disk-shaped mold size: φ200 mm × thickness 20 mm · Disk-shaped mold material: SS400 · Mold heating temperature: 300 °C · Spray gun: LPH-100 spray gun (manufactured by Anest Iwata) · Spray air pressure: 0.2 MPa · Distance between mold and spray gun: 200 mm · Coolant spray amount: 5 g · Method for measuring mold temperature: Insert a thermocouple from the side of the mold to a position 5 mm deep from the center of the upper surface of the mold to measure the mold temperature · Hot plate: AS ONE ceramic hot plate (product number: CHP-250DF) · Size of aluminum plate for soaking: 250 mm × 250 mm × thickness 10 mm <Test Procedure> (1) Place the aluminum plate for soaking on the top plate of the hot plate, and further place the disk-shaped mold on the aluminum plate for soaking. (2) Start heating with the hot plate so that the mold temperature reaches 300 °C. (3) After confirming that the mold temperature has reached 300 °C and stabilized, cool the mold according to the following procedure. · Fill the spray gun with a predetermined amount of coolant. · Start measuring the mold temperature with a data logger. · Stop heating the hot plate, and using the spray gun, spray the coolant onto the upper surface of the mold under the conditions of the above-mentioned distance between the mold and the spray gun, spray air pressure, and coolant spray amount. · After confirming that the mold temperature has dropped once and then risen again due to the spraying of the coolant, end the measurement with the data logger. (4) Remove the coolant adhering to the mold, return to step (2), and conduct the next test.

[0034] After the mold cooling test, based on the results of the data logger, the minimum value of the mold temperature when the mold temperature once dropped due to the spraying of each coolant was confirmed, and the maximum drop amount (°C) from 300 °C of the mold temperature was obtained. The evaluation of the mold cooling performance of each coolant was classified as follows based on the maximum drop amount of the mold temperature. The results are shown in Tables 1 and 2. S: 45 °C or more A: 40 °C or more and less than 45 °C B: 35 °C or more and less than 40 °C C: 30 °C or more and less than 35 °C D: Less than 30 °C

[0035] (3. Measurement of Friction Coefficient by Ring Compression Test Method) For each coolant prepared above, the friction coefficient was measured by the ring compression test method. A ring with an outer diameter of 30 mm × inner diameter of 15 mm × thickness of 10 mm and a material of S45C spheroidized annealed material was heated to 1000 °C in a muffle furnace and held for 5 minutes. The temperature of the ring was measured by welding a thermocouple to the ring. One upper and one lower flat mold with a size of φ50.8 mm × thickness of 10 mm and a material of SKD61 (quenched) were prepared. After heating these upper and lower molds to 300 °C, each coolant was sprayed onto the contact surface between the upper and lower molds and the ring using a spray gun (LPH - 100 (manufactured by Anest Iwata)) under the conditions of a spray air pressure of 0.2 MPa and a spray time of 2 seconds. Next, the above - mentioned ring heated to 1000 °C was sandwiched between the upper and lower molds after applying the coolant, and compressed at a processing speed of 30 spm and a compression ratio of 52% using a 2000 kN crank press machine (MSF200 (manufactured by Fukui Machinery)).

[0036] The inner diameter and thickness of the compressed ring were measured to calculate the inner diameter change rate, and plotted on the theoretical curve of compression ratio - inner diameter change rate using CAE analysis software (COLD FORM) to obtain the friction coefficient (μ) of each coolant. The evaluation of the friction coefficient of each coolant was classified as follows. The results are shown in Tables 1 and 2. S: Less than 0.1 A: 0.1 or more and less than 0.14 B: 0.14 or more and less than 0.18 C: 0.18 or more and less than 0.22 D: 0.22 or more

[0037]

Table 1-1

[0038]

Table 1-2

[0039]

Table 2

Claims

**Claim 1** A coolant for plastic processing molds, which is a liquid obtained by directly dispersing the following component A and component B in water, a water-miscible organic solvent, or a mixture of both, with the ratio of the total mass of component A to the total mass of component B being in the range of 2.0 or more and 35.5 or less. Component A: One or more silicate-containing minerals; Component B: One or more compounds selected from the group consisting of aliphatic carboxylic acids and their salts, aliphatic hydroxy acids and their salts, aromatic carboxylic acids and their salts, and aromatic hydroxy acids and their salts, and having 12 to 22 carbon atoms.

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