Metalworking oil composition for cold rolling and metalworking method

Abstract

To provide a metal processing oil composition for cold rolling that is less susceptible to heat generated during cold rolling and metal wear powder derived from a rolled material mixed during the cold rolling.SOLUTION: A metal processing oil agent composition for cold rolling comprises: (A) 44 to 90 mass% of a base oil, (B) 0.5 to 4 mass% of nonionic surfactant, (C) 1 to 20 mass% of phospholipids, (D) 0.5 to 2 wt.% of di-benzylamine, (E) 0.5 to 20 mass% of a hydrocarbon substituted succinic acid having 10 to 20 carbon atoms, and (F) 0.5 to 10 mass% of a hydrocarbon-substituted succinic acid having 50 to 90 carbon atoms, based on total mass of the composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a metalworking oil composition for use in cold rolling and a metalworking method. [Background technology]

[0002] Water-soluble metal working oil agents, for example, water-soluble plastic working oil agents, are prepared by blending mineral oil, natural fats and oils, synthetic esters, or other base oils with oiliness improvers, extreme-pressure additives, antioxidants, rust inhibitors, surfactants, dispersants, preservatives, and other additives, and adjusting the resulting emulsion to suit the intended purpose. Water-soluble metal rolling oils used in rolling, a type of plastic processing, are diluted with water and recycled as emulsions. They reduce friction between the rolls and the rolled material and absorb the enormous amount of heat generated during rolling, cooling the rolls and the rolled material. However, the emulsion's emulsified state can become unstable due to shear stress caused by circulation, absorbed heat, and wear particles generated during rolling. Therefore, various efforts have been made to reduce the impact of heat and wear particles generated during rolling. For example, Patent Document 1 discloses a water-soluble metalworking oil composition that contains a base oil, a surfactant, and a phospholipid, thereby reducing the impact of heat and wear particles generated during rolling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-279976 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, an object of the present invention is to provide a metalworking oil composition for cold rolling that is less susceptible to the effects of heat generated during cold rolling and metal wear particles derived from the rolled material that are mixed in during cold rolling. Another object of the present invention is to provide a metalworking method using the above metalworking oil composition for cold rolling. [Means for solving the problem]

[0005] 1. Based on the total weight of the composition, (A) 44 to 90 mass% of a base oil, (B) 0.5 to 4 mass% of a nonionic surfactant, (C) 1 to 20 mass% of a phospholipid, (D) 0.5 to 2 mass% of dibenzylamine, (E) 0.5 to 20 mass% of a hydrocarbon-substituted succinic acid having 10 to 20 carbon atoms, and (F) 0.5 to 10 mass% of a hydrocarbon-substituted succinic acid having 50 to 90 carbon atoms A metalworking oil composition for cold rolling comprising: 2. The metalworking oil composition for cold rolling according to item 1, further comprising (G) at least one selected from the group consisting of organic phosphonic acids and esters thereof, organic phosphinic acids and esters thereof, phosphate esters, phosphites, and hypophosphites. 3. The metalworking oil composition for cold rolling according to item 1 or 2 above, further comprising (H) at least one selected from the group consisting of phenolic antioxidants and amine-based antioxidants. 4. The metalworking oil composition for cold rolling according to any one of the above items 1 to 3, further comprising (I) at least one member selected from the group consisting of hydrocarbon polymers and ester polymers. 5. The metalworking oil composition for cold rolling according to any one of items 1 to 4 above, wherein (A) the base oil is at least one selected from the group consisting of natural fats and oils, mineral oils, derivatives of natural fats and oils, and synthetic esters. 6. A metalworking method, comprising working a metal material using the metalworking oil composition for cold rolling according to any one of items 1 to 5 above. 7. The metalworking method according to item 6 above, wherein the metalworking oil composition according to any one of items 1 to 5 above is used as a cold rolling oil in cold rolling. [Effects of the Invention]

[0006] The metalworking oil composition for cold rolling of the present invention has excellent emulsion stability, allowing for efficient cold rolling. The composition of the present invention also has excellent oil burn resistance, a high seizure load, and a friction coefficient in an appropriate range, so that the metalworked product obtained by the metalworking method of the present invention has a good worked surface and working accuracy. The composition of the present invention also has excellent long-term storage stability. DETAILED DESCRIPTION OF THE INVENTION

[0007] The base oil (A) used in the present invention can be any oil without particular limitation, and is preferably at least one selected from the group consisting of natural fats and oils or derivatives thereof, mineral oils, synthetic oils (particularly synthetic ester oils), and mixtures thereof. From the viewpoints of lubricity and cost, the base oil (A) of the present invention is preferably selected from the group consisting of natural fats and oils, derivatives thereof, mineral oils, synthetic ester oils, and mixtures thereof. Therefore, when these preferred base oils are used in combination with other base oils, it is desirable that the preferred base oils account for 70 mass % or more, preferably 80 mass % or more, more preferably 90 mass % or more, and particularly 100 mass % of the total base oils. Ester oils have polar groups in their molecules and form an adsorbed film with good lubricity on metal surfaces, so it is preferable to include ester oils in terms of lubricity and adsorption to new surfaces. Therefore, when ester oils are used in combination with other base oils, whether natural or synthetic, it is desirable that the ester oils account for 70% by mass or more of the total base oil, preferably 80% by mass or more, more preferably 90% by mass or more, and particularly 100% by mass.

[0008] Examples of natural fats and oils include rapeseed oil, soybean oil, castor oil, coconut oil, palm oil, palm olein oil, beef tallow, and lard. Palm olein oil is preferred as the natural fat and oil. In particular, from the viewpoint of lubricity, palm olein oil having an iodine value (measured according to JIS K0070.6) of 56 to 72 and a slip melting point (the melting point at which the fat and oil begins to melt, measured according to the standard method for analyzing fats and oils) of 24°C or lower is preferred. Examples of the natural fat derivatives include hydrogenated products of these natural fats and oils, castor seed oil to which alkylene oxide is added, etc. As the natural fat derivatives, hydrogenated palm olein oil is preferred, and hydrogenated palm olein oil having an iodine value of 56 to 72 and a slip melting point of 16 to 24°C is more preferred. Mineral oils include naphthenic and paraffinic mineral oils, with paraffinic mineral oils being preferred.

[0009] Examples of synthetic oils include synthetic hydrocarbon oils such as poly-α-olefins and polybutenes; ether-based synthetic oils such as alkyl diphenyl ethers and polypropylene glycols; monoesters such as methyl oleate, 2-ethylhexyl stearate, 2-ethylhexyl palmitate, and butyl stearate; dibasic acid esters such as di-2-ethylhexyl sebacate and di-2-ethylhexyl adipate; synthetic ester oils such as partial esters and full esters of polyhydric alcohol esters such as trimethylolpropane trioleate and pentaerythritol tetraoleate; silicone oils; and fluorinated oils. As the synthetic oil, synthetic ester oil is preferred. Monoesters such as 2-ethylhexyl stearate, 2-ethylhexyl palmitate, and butyl stearate; dibasic acid esters such as di-2-ethylhexyl sebacate and di-2-ethylhexyl adipate; and full esters of polyhydric alcohols such as trimethylolpropane trioleate and pentaerythritol tetraoleate are more preferred. A combination of a dibasic acid ester such as di-2-ethylhexyl sebacate or di-2-ethylhexyl adipate with trimethylolpropane trioleate is most preferred. In particular, a combination of di-2-ethylhexyl sebacate and trimethylolpropane trioleate is preferred.

[0010] As the base oil (A) of the present invention, a mixture of a natural fat derivative and a synthetic ester oil is particularly preferred, and among these, a combination of a hydrogenated palm olein oil having an iodine value of 56 to 72 and an elevation melting point of 16 to 24°C, di-2-ethylhexyl sebacate, and trimethylolpropane trioleate is preferred. In particular, a mixture of these three is preferred, in which the amount of the hydrogenated palm olein oil having an iodine value of 56 to 72 and an elevation melting point of 16 to 24°C is 10 to 18 times the mass of di-2-ethylhexyl sebacate, and the amount of trimethylolpropane trioleate is 1 to 2 times the mass of di-2-ethylhexyl sebacate.

[0011] The mass proportion of the base oil (A) used in the oil agent composition of the present invention is 44 to 90 mass%, preferably 50 to 90 mass%, and more preferably 70 to 90 mass%, based on the total mass of the composition. By making it 44 mass% or more, an optimal coefficient of friction can be obtained even during high-speed rolling. By making it 90 mass% or less, the coefficient of friction can be prevented from becoming too low, preventing adverse effects such as slippage.

[0012] The nonionic surfactant (B) used in the oil composition of the present invention includes not only low-molecular-weight surfactants but also polymeric surface-active substances. The nonionic surfactant used in the present invention is not particularly limited. Preferably, at least one surfactant selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene-modified fatty acid esters, polyoxyethylene nonylphenol ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, hydrogenated castor oil polyoxyethylene adducts, polyoxyethylene diglycerin, and partially hydrolyzed polyoxyethylene adducts of fats and oils. Among these, polyoxyethylene sorbitol fatty acid esters, hydrogenated castor oil polyoxyethylene adducts, polyoxyethylene nonylphenol ethers, and nonionic polymers (particularly copolymers of maleated polybutene, polyalkylene glycol, and glycerin) are more preferred. The polyoxyethylene may be a mix or block polymer of oxyethylene and oxypropylene. Polyoxyethylene (30) sorbitol fatty acid esters, hydrogenated castor oil polyoxyethylene (10) adducts, polyoxyethylene (20) nonylphenol ethers, and nonionic polymers (particularly copolymers of maleated polybutene, polyalkylene glycol, and glycerin) are particularly preferred. Of these, a combination of polyoxyethylene (30) sorbitol fatty acid esters and hydrogenated castor oil polyoxyethylene (10) adducts is particularly preferred. The number in parentheses indicates the number of moles of ethylene oxide added. In particular, a mixture of these in which the amount of hydrogenated castor oil polyoxyethylene (10) adduct is 0.5 to 1.5 times the mass of polyoxyethylene (30) sorbitol fatty acid ester is preferred.

[0013] The mass proportion of the nonionic surfactant (B) in the oil agent composition of the present invention is 0.5 to 4 mass%, more preferably 0.6 to 3 mass%, and even more preferably 0.7 to 2 mass%, based on the total mass of the composition. Since the nonionic surfactant acts as an emulsifier in the composition of the present invention, by including it in the oil agent composition in this range, the emulsion can be stabilized.

[0014] Examples of the (C) phospholipids used in the oil solution composition of the present invention include egg yolk lecithin and soybean lecithin. Egg yolk lecithin, soybean lecithin, and the like are commercially available in both highly refined powder form and less refined liquid form. This lecithin is a mixture of various phospholipid molecular species, such as phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol, with triglycerides (mainly soybean oil). The phospholipids used in the oil solution composition of the present invention may be in any form, but liquid forms are easily dissolved in base oils and are suitable for producing oil solutions. Liquid soybean lecithin is particularly preferred. Phospholipids are generally available on the market, and commercially available products can be used in the present invention. Examples of such commercially available products include Lecithin (manufactured by Ajinomoto Co., Inc.) and Lecithin DX (manufactured by Nisshin Oillio Co., Ltd.).

[0015] In the oil agent composition of the present invention, the mass ratio of the phospholipid is 1 to 20 mass%, preferably 1 to 15 mass%, more preferably 1 to 10 mass%, and even more preferably 2 to 5 mass%, based on the total mass of the composition. Because the phospholipid also acts as an emulsifier in the composition of the present invention, incorporating it in this range in the oil agent composition can uniformly emulsify the entire composition. This allows the amount of the composition of the present invention that adheres to the rolled material to be optimized, resulting in good lubrication and preventing adverse effects such as oil burn.

[0016] The mass ratio of (D) dibenzylamine used in the oil composition of the present invention is 0.5 to 2 mass%, preferably 0.6 to 1.75 mass%, and more preferably 0.7 to 1.5 mass%, based on the total mass of the composition. Dibenzylamine acts as an alkali agent in the composition of the present invention. Various amines, such as dicyclohexylamine, diphenylamine, and tributylamine, can generally be used as alkali agents in metalworking oils. By incorporating a predetermined amount of dibenzylamine, the present invention can provide an oil composition with excellent stability, which can maintain the emulsion shape and size even if metal wear particles from the rolled material are mixed in during processing.

[0017] The (E) hydrocarbon-substituted succinic acid having 10 to 20 carbon atoms used in the oil composition of the present invention includes alkenylsuccinic acid having an alkenyl group having 10 to 20 carbon atoms or anhydride thereof. Alkenylsuccinic acid having an alkenyl group having 15 carbon atoms and anhydride of alkenylsuccinic acid having an alkenyl group having 12 carbon atoms are preferred.

[0018] The mass proportion of the (E) hydrocarbon-substituted succinic acid having 10 to 20 carbon atoms used in the oil agent composition of the present invention is 0.5 to 20 mass%, preferably 1 to 15 mass%, more preferably 1 to 10 mass%, and even more preferably 3 to 5 mass%, based on the total mass of the composition. By setting the mass within this range, oil scorch is effectively prevented, the lubricating component is effectively adhered to the rolled material, good lubricity is exhibited, and staining of the rolled material can be prevented.

[0019] The (F) succinic acid substituted with a hydrocarbon having 50 to 90 carbon atoms used in the oil agent composition of the present invention includes succinic acid substituted with a hydrocarbon having 58 carbon atoms and succinic acid substituted with a hydrocarbon having 72 carbon atoms.

[0020] The mass proportion of (F) the hydrocarbon-substituted succinic acid having 50 to 90 carbon atoms used in the oil agent composition of the present invention is 0.5 to 10 mass%, preferably 0.5 to 7 mass%, more preferably 0.5 to 5 mass%, and even more preferably 0.5 to 2 mass%, based on the total mass of the composition. A content of 0.5 mass% or more effectively improves the selective adsorption of component (E). The upper limit is the concentration that allows the viscosity of the oil agent composition to fall within an appropriate range and prevents adverse effects such as slippage due to excessive adhesion. Furthermore, adding more than 10 mass% does not provide the desired effect commensurate with the amount added, and is therefore uneconomical.

[0021] As optional components, (G) organic phosphonic acids and esters thereof, organic phosphinic acids and esters thereof, phosphates, phosphites, and hypophosphites may be used in the oil agent composition of the present invention. Of these, phosphates, phosphites, and hypophosphites are preferred.

[0022] The organic phosphonic acid and its ester are preferably those represented by the following general formula (1). [ka] [In formula (1), R 1 is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms; R 2 and R 3 is a hydrogen atom, a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms.

[0023] The organic phosphinic acid and its ester are preferably those represented by the following general formula (2). [ka] [In formula (2), R 4 is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms; R 5 and R 6 is a hydrogen atom, a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms.

[0024] The phosphate ester is preferably one represented by the following general formula (3). [ka] [In formula (3), R 7 , R 8 and R 9 is a hydrogen atom, a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms. 7, R 8 and R 9 and cannot simultaneously be hydrogen atoms.

[0025] The phosphite ester is preferably one represented by the following general formula (4), (5) or (6). [ka] [ka] [ka]

[0026] [In formulas (4), (5), (6), R 10 , R 11 , R 12 , R 15 , R 16 , R 18 and R 19 is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms; R 17 represents an alkylene group having 1 to 24 carbon atoms, an alkenylene group having 2 to 24 carbon atoms, an arylene group having 6 to 24 carbon atoms, an arylene alkylene group having 7 to 24 carbon atoms, an alkylarylene group having 7 to 24 carbon atoms, an alkylene oxide group having 2 to 4 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms; R 13 , R 14 is a hydrogen atom, a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms, provided that R 13 and R 14 and n are numbers from 1 to 20.

[0027] The hypophosphite ester is preferably one represented by the following general formula (7), (8) or (9). [ka] [ka] [ka] [In formulas (7), (8), and (9), R 20 , R 22 , R 23 , R 24 , R 25 , R 27 , R 28 is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms; R 21 is a hydrogen atom, a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms, preferably 5 to 15 carbon atoms; R 26 represents an alkylene group having 1 to 24 carbon atoms, an alkenylene group having 2 to 24 carbon atoms, an arylene group having 6 to 24 carbon atoms, an arylene alkylene group having 7 to 24 carbon atoms, an alkylarylene group having 7 to 24 carbon atoms, an alkylene oxide group having 2 to 4 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms.

[0028] Specific examples of organic phosphonic acids and esters thereof include methylphosphonic acid, ethylphosphonic acid, phenylphosphonic acid, tolylphosphonic acid, benzylphosphonic acid, methyl methylphosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, and diethyl phenylphosphonate.

[0029] Examples of organic phosphinic acids and esters thereof include methylphosphinic acid, ethylphosphinic acid, diethylphosphinic acid, methylethylphosphinic acid, phenylphosphinic acid, methylphenylphosphinic acid, phenylphosphinic acid, ethyl methylphosphinate, ethyl dimethylphosphinate, phenyl methylphosphinate, and ethyl phenylphosphinate.

[0030] Examples of the phosphate ester include aliphatic phosphate esters such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, triisopropyl phosphate, tributyl phosphate, and triisobutyl phosphate; di-C1-22 alkyl phosphate esters such as dimethyl phosphate, diethyl phosphate, dipropyl phosphate, dibutyl phosphate, and di(2-ethylhexyl) phosphate; and mono-C1-22 alkyl phosphate esters such as monomethyl phosphate, monoethyl phosphate, monopropyl phosphate, monoisopropyl phosphate, monobutyl phosphate, and monoisobutyl phosphate; aromatic phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylyl phosphate, diphenylcresyl phosphate, tri(isopropylphenyl) phosphate, and diphenylethylcresyl phosphate; and aliphatic-aromatic phosphate esters such as methyl diphenyl phosphate and phenyl diethyl phosphate. Of these, tri-C1-22 alkyl phosphate and tri-C6-22 aryl phosphate are preferred, with tributyl phosphate and tricresyl phosphate being particularly preferred.

[0031] Examples of the phosphite ester include aromatic phosphites such as triphenyl phosphite, tricresyl phosphite, trixylyl phosphite, and diphenylcresyl phosphite, tri-C6-22 aryl phosphite esters; aliphatic phosphites such as trimethyl phosphite, triethyl phosphite, tripropyl phosphite, triisopropyl phosphite, tributyl phosphite, triisobutyl phosphite, and trioleyl phosphite, tri-C1-22 alkyl phosphite esters; dimethyl phosphite, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, and dilauryl phosphite, di-C1-22 alkyl phosphite esters; monomethyl phosphite, monoethyl phosphite, monopropyl phosphite, monoisopropyl phosphite, monobutyl phosphite, and monoisobutyl phosphite. aliphatic-aromatic phosphites include alkylphosphonic acid aryl esters such as diphenyl methanephosphonate and diethyl methanephosphonate; and other examples include trisnonylphenyl phosphite, tris(2-ethylhexyl)phosphite, tris(tridecyl)phosphite, diphenyl mono(2-ethylhexyl)phosphite, diphenyl mono(tridecyl)phosphite, tetraphenyldiethylene glycol diphosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyldibutylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, and bis(tridecyl)pentaerythritol diphosphite. Of these, di-C1-22 alkyl phosphite is preferred, and dilauryl phosphite is particularly preferred.

[0032] Examples of hypophosphite esters include dihypophosphite esters such as dimethyl hypophosphite, diethyl hypophosphite, dipropyl hypophosphite, dibutyl hypophosphite, dihexyl hypophosphite, dioctyl hypophosphite, didecyl hypophosphite, methyl-diphenylphosphonite, ethyl-diphenylphosphonite, propyl-diphenylphosphonite, butyl-diphenylphosphonite, hexyl-diphenylphosphonite, octyl-diphenylphosphonite, decyl-diphenylphosphonite, bis[bis(2,4-di-t-butyl-5-methylphenoxy) Examples of hypophosphite monoesters include monomethyl hypophosphite, monoethyl hypophosphite, monopropyl hypophosphite, monobutyl hypophosphite, monohexyl hypophosphite, monooctyl hypophosphite, and monodecyl hypophosphite. Further examples include bis(diphenoxyphosphino)methane, 1,2-bis(diphenoxyphosphino)ethane, 1,3-bis(diphenoxyphosphino)propane, 1,6-bis(diphenoxyphosphino)methane, 1,2-bis(diphenoxyphosphino)ethane, 1,3-bis(diphenoxyphosphino)propane, 1,6-bis(diphenoxyphosphino) (diphosphino)hexane, 1,8-bis(diphenoxyphosphino)octane, tetraphenyl-1,4-phenylene diphosphonite, tetraphenyl-4,4'-biphenylene diphosphonite, tetrakis(4-methylphenyl)ethylene diphosphonite, tetrakis(4-methylphenyl)-1,3-phenylene diphosphonite, tetrakis(4-methylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-t-butylphenyl)ethylene diphosphonite, tetrakis(2,4-di-t-butylphenyl)-1,3 -phenylene diphosphonite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-t-butyl-5-methylphenyl)ethylene diphosphonite, tetrakis(2,4-di-t-butyl-5-methylphenyl)-1,3-phenylene diphosphonite, tetrakis(2,4-di-t-butyl-5-methylphenyl)-4,4'-biphenylene diphosphonite, tetraphenyl-4,4'-isopropylidenediphenyl diphosphonite, tetrakis(2,4-t-butylphenyl)-4,4'-isopropylidenediphenyl diphosphonite, etc. Of these, dioctyl hypophosphite and 1,2-bis(diphenoxyphosphino)ethane are preferred.

[0033] The amount of (G) organic phosphonic acid and its ester, organic phosphinic acid and its ester, phosphate ester, phosphite ester and hypophosphite ester relative to the total amount of the oil agent composition of the present invention is preferably 0.3 to 10 mass %, more preferably 0.5 to 5 mass %.

[0034] The oil agent composition of the present invention may further contain, as optional components, (H) a phenolic antioxidant and / or an amine antioxidant, and (I) a hydrocarbon polymer and / or an ester polymer.

[0035] Examples of the phenolic antioxidants of component (H) include BHT (butylated hydroxytoluene), thiodiethylene bispropionate, and pentaerythritol tetrakispropionate, and examples of the amine antioxidants include alkylphenyl-α-naphthylamine, phenyl-1-naphthylamine, and octylbutyldiphenylamine. When the entire oil agent composition of the present invention contains component (H), the content thereof relative to the entire composition is preferably 0.5 to 1.5% by mass.

[0036] Examples of hydrocarbon polymers of component (I) include polyisobutylene or polybutene having a weight-average molecular weight of 40,000 to 80,000, and examples of ester polymers include methacrylate copolymers or alkyl methacrylate copolymers having a weight-average molecular weight of 150,000 to 200,000. Polyisobutylene having a weight-average molecular weight of 40,000 to 80,000 and alkyl methacrylate copolymers having a weight-average molecular weight of 150,000 to 200,000 are preferred, and polyisobutylene having a weight-average molecular weight of 60,000 and alkyl methacrylate copolymers having a weight-average molecular weight of 180,000 are more preferred. When the entire oil agent composition of the present invention contains component (I), the content thereof relative to the entire composition is preferably 2 to 5 mass %.

[0037] In particular, the oil composition of the present invention is (A) A combination of 70 to 90% by mass of hydrogenated palm olein oil having an iodine value of 56 to 72 and a slip melting point of 16 to 24°C, di-2-ethylhexyl sebacate, and trimethylolpropane trioleate, wherein the amount of hydrogenated palm olein oil having an iodine value of 56 to 72 and a slip melting point of 16 to 24°C is 10 to 18 times the mass of di-2-ethylhexyl sebacate, and the amount of trimethylolpropane trioleate is 1 to 2 times the mass of di-2-ethylhexyl sebacate; (B) a combination of 0.7 to 2% by mass of a polyoxyethylene (30) sorbitol fatty acid ester and a hydrogenated castor oil polyoxyethylene (10) adduct, wherein the amount of the hydrogenated castor oil polyoxyethylene (10) adduct is 0.5 to 1.5 times the mass of the polyoxyethylene (30) sorbitol fatty acid ester; (C) 2 to 5 mass% liquid soybean lecithin, (D) 0.7 to 1.5 mass% dibenzylamine, (E) 3 to 5% by mass of at least one selected from the group consisting of alkenyl succinic acids having an alkenyl group with 15 carbon atoms and alkenyl succinic anhydrides having an alkenyl group with 12 carbon atoms, and (F) 0.5 to 2 mass% of at least one selected from the group consisting of hydrocarbon-substituted succinic acid having 58 carbon atoms and hydrocarbon-substituted succinic acid having 72 carbon atoms; A metalworking oil composition for cold rolling comprising the following is preferred.

[0038] Among these, the oil agent composition of the present invention is (A) A combination of 70 to 90% by mass of hydrogenated palm olein oil having an iodine value of 56 to 72 and a slip melting point of 16 to 24°C, di-2-ethylhexyl sebacate, and trimethylolpropane trioleate, wherein the amount of hydrogenated palm olein oil having an iodine value of 56 to 72 and a slip melting point of 16 to 24°C is 10 to 18 times the mass of di-2-ethylhexyl sebacate, and the amount of trimethylolpropane trioleate is 1 to 2 times the mass of di-2-ethylhexyl sebacate; (B) a combination of 0.7 to 2% by mass of a polyoxyethylene (30) sorbitol fatty acid ester and a hydrogenated castor oil polyoxyethylene (10) adduct, wherein the amount of the hydrogenated castor oil polyoxyethylene (10) adduct is 0.5 to 1.5 times the mass of the polyoxyethylene (30) sorbitol fatty acid ester; (C) 2 to 5 mass% liquid soybean lecithin, (D) 0.7 to 1.5 mass% dibenzylamine, (E) 3 to 5 mass% of succinic acid having an alkenyl group having 15 carbon atoms, (F) 0.5 to 2 mass% of succinic acid having a hydrocarbon group with 72 carbon atoms, (G) 0.5 to 5% by mass of a combination of dilauryl phosphite and tricresyl phosphate (H) 0.5 to 1.5 mass% of a combination of butylated hydroxytoluene and phenyl-1-naphthylamine, (I) 2 to 5 mass% of an alkyl methacrylate copolymer having a weight-average molecular weight of 180,000 A metalworking oil composition for cold rolling comprising the following is preferred.

[0039] The oil agent composition of the present invention can be easily produced by mixing and dissolving components (A) to (F) and, optionally, components (G) to (I) under appropriate temperature conditions, for example, at about 40 to 70°C.

[0040] The metalworking oil composition of the present invention preferably has a pH of 7.0 to 11, and more preferably 8.0 to 11, at 25°C in a 5% by mass diluted solution. With a pH in this range, the composition has good antiseptic properties while suppressing skin irritation. As the pH adjuster, amines other than component (D) can be used, for example, amines having an alicyclic group such as dicyclohexylamine or their EO adducts, and amines having an aromatic cyclic group such as metaxylenediamine.

[0041] The metalworking oil composition of the present invention is generally used after dilution with water, which may be any of ultrapure water, distilled water, ion-exchanged water, tap water, city water, industrial water, etc. The oil composition of the present invention is used in cold rolling. The concentration of the oil composition when used in cold rolling can be appropriately determined by one skilled in the art; for example, the oil composition of the present invention can be diluted with water so that the concentration at the time of use is preferably 0.5 to 10 mass %, more preferably 1 to 5 mass %, and most preferably 1 to 3 mass %. Examples of rolling members include ferrous steel sheets such as low carbon steel, high tensile steel sheet, stainless steel, and silicon steel sheet, as well as non-ferrous materials such as aluminum, aluminum alloy, titanium, and titanium alloy. The oil composition of the present invention can be applied to one or both of the surface of the workpiece and the surface of the tool using a conventional means (for example, using a nozzle to supply oil at the entry side of the rolling mill) in a conventional amount (for example, 4 to 8 m per stand). 3 / min). [Example]

[0042] The components shown in the table below were mixed in the mass ratios shown in the table below to prepare oil compositions. The properties of these oil compositions were evaluated by the following methods.

[0043] (1) Emulsion stability 1 This test is a test for evaluating the initial emulsifying performance of an oil agent composition. Specifically, the oil solution composition prepared above was diluted with ion-exchanged water (400 ml, 50-55°C) so that the concentration of the oil solution composition in the emulsion was 2% by mass, and the mixture was stirred at 8,000 rpm for 3 minutes using a homogenizer (TK Homomixer MARK II 2.5, manufactured by Primix Corporation) to obtain an emulsion of the oil solution composition. The emulsion stability of the resulting emulsion was evaluated based on particle size and ESI value. Particle size is the volume average diameter measured using a particle size distribution analyzer (Coulter Multisizer III, manufactured by Coulter). ESI value is an abbreviation for Emulsion Stability Index, and is an index used to evaluate the emulsion stability of an oil solution emulsion. Specifically, 400 ml of the oil solution emulsion was placed in a cylindrical separatory funnel and allowed to stand for 8 minutes. 100 ml of each of the upper and lower layers was then sampled, and the concentration of the oil solution composition in each phase (i.e., the oil concentration) was analyzed and expressed as the ratio of the oil concentration in the lower layer to the oil concentration in the upper layer. The evaluation was based on the following criteria: ○: Emulsion particle size less than 5 μm and ESI value 0.8 or more ×: Emulsion particle size is 5 μm or more, or ESI value is less than 0.8

[0044] (2) Emulsion stability 2 This test is conducted to evaluate the degree of deterioration in the performance of the oil agent composition, since the emulsification performance during rolling can be deteriorated due to the inclusion of metal wear particles from the rolled material during processing. Specifically, the oil agent composition prepared above was diluted with ion-exchanged water (400 ml, 50-55°C, 2000 ppm iron fine powder added) so that the concentration of the oil agent composition in the emulsion was 2% by mass. The mixture was stirred at 8000 rpm for 3 minutes in a homogenizer (TK Homomixer MARK II 2.5, manufactured by Primix Corporation) and boiled to 200 ml. Ion-exchanged water was added to make the total volume 400 ml, and the mixture was again stirred at 8000 rpm in the homomixer for 3 minutes to obtain an emulsion of the oil agent composition. The emulsion stability of the emulsion was evaluated in terms of particle size and ESI value using the same method as described for emulsion stability 1. The iron fine powder added had a particle size of 20 nm, simulating wear particles generated during metalworking. Evaluation was based on the following criteria. ○: Emulsion particle size less than 15 μm and ESI value 0.6 or more ×: Emulsion particle size is 15 μm or more, or ESI value is less than 0.6 (3) Seizure load (N) The seizure load of the oil agent compositions of the Examples and Comparative Examples was evaluated as the limit load (N) at which seizure occurred using a Soda-type four-ball pressure tester. The evaluation was based on the following criteria. ○: Limit load 100N or more ×: Limit load less than 100N

[0045] (4) Friction coefficient The friction coefficients of the oil compositions of the Examples and Comparative Examples were measured using a high-speed plate threading tester (roll diameter = 240 mmΦ, test piece = SPCC material immediately after rolling; width 30 mm × thickness 0.8 mm, rolling speed = 1000 m / min, reduction 40%). Evaluation was based on the following criteria. ○: 0.025~0.045 ×: Less than 0.025 or more than 0.045 If the ratio is less than 0.025, there is a high risk of slippage, and if the ratio exceeds 0.045, the rolling power becomes high.

[0046] (5) Oil burn resistance The oil scorch resistance of the oil agent compositions of the Examples and Comparative Examples was evaluated by rolling test pieces (SPCC material immediately after rolling, thickness 0.8 mm) in a low-speed rolling mill (roll diameter = 150 mmΦ, rolling speed 15 m / min, reduction 20%), packaging them in aluminum foil without draining them, pressing them with a pressure plate, and leaving them in a 120°C thermostatic bath for 20 hours, and then evaluating the occurrence of oil scorch. The evaluation was based on the following criteria. ○: No oil burn △: A small amount of oil burn occurs ×: A large amount of oil burns

[0047] (6) Overall evaluation Pass (○): All are ○ or △ Fail (×): If there is even one × The results are shown in the table below.

[0048] [Table 1]

[0049]

Table 2

[0050]

Table 3

[0051]

Table 4

[0052]

Table 5

[0053]

Table 6

[0054]

Table 7

[0055]

Table 8

[0056]

Table 9

[0057]

Table 10

Claims

1. Based on the total weight of the composition, (A) 44 to 90% by mass of a base oil; (B) 0.5 to 4 mass% of a nonionic surfactant, (C) 1 to 20% by mass of a phospholipid; (D) 0.5 to 2% by mass of dibenzylamine, (E) 0.5 to 20% by mass of a hydrocarbon-substituted succinic acid having 10 to 20 carbon atoms, and (F) 0.5 to 10% by mass of a hydrocarbon-substituted succinic acid having 50 to 90 carbon atoms A metalworking oil composition for cold rolling comprising:

2. 2. The metalworking oil composition for cold rolling according to claim 1, further comprising (G) at least one selected from the group consisting of organic phosphonic acids and esters thereof, organic phosphinic acids and esters thereof, phosphates, phosphites, and hypophosphites.

3. 3. The metalworking oil composition for cold rolling according to claim 1, further comprising (H) at least one selected from the group consisting of phenolic antioxidants and amine-based antioxidants.

4. The metalworking oil composition for cold rolling according to any one of claims 1 to 3, further comprising (I) at least one member selected from the group consisting of hydrocarbon polymers and ester polymers.

5. 5. The metalworking oil composition for cold rolling according to claim 1, wherein the base oil (A) is at least one selected from the group consisting of natural fats and oils, mineral oils, derivatives of natural fats and oils, and synthetic esters.

6. A metalworking method comprising working a metal material using the metalworking oil composition for cold rolling according to any one of claims 1 to 5.

7. 7. The metalworking method according to claim 6, wherein the metalworking oil composition according to any one of claims 1 to 5 is used as a cold rolling oil in cold rolling.

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