JP2016216536A - Aqueous lubricant, metallic material and metal worked part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous lubricant for metallic material plastic working capable of forming a lubricant film, e.g., excellent in lubricity under a high-humidity environment (moisture absorption resistance) and seizure resistance to high easiness metal working, and also excellent in long period chemical stability, a metallic material having a lubricant film formed by the aqueous lubricant on the surface, and a metal worked part obtained by molding the metallic material.SOLUTION: Provided is an aqueous lubricant for metallic material plastic working in which aliphatic polycarboxylic acid having the carbon number of 5 to 8 and a solubility to water at 20°C of 10 g/100 mL or more and an alkaline-earth metal compound are blended into water, or the alkaline-earth metal salt of the aliphatic polycarboxylic acid is dissolved or dispersed into water.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous lubricant for metal material plastic working, a metal material having a lubricant film formed on the surface thereof, and a metal workpiece obtained by molding the metal material.

  In plastic processing such as wire drawing, tube drawing, plate pressing, forging, forging, etc., a lubrication film is applied to the friction interface between the mold and the workpiece to facilitate processing into the desired shape and suppress the occurrence of seizure. Is formed. In recent years, a technique capable of forming this lubricating film with a single solution has been proposed. For example, Patent Document 1 discloses an alkaline earth metal salt of an aliphatic monocarboxylic acid having 1 to 4 carbon atoms, an alkaline earth metal salt of an aliphatic dicarboxylic acid having 2 to 4 carbon atoms, or 1 to 2 hydroxyl groups. A water-soluble lubricant for plastic working has been proposed which contains at least an alkaline earth metal salt of an aliphatic carboxylic acid having 2 to 4 carbon atoms having a group. According to this technique, it is possible to provide a water-soluble lubricant for plastic working that is excellent in lubricity and does not cause precipitation and solidification and does not cause rough or worn tools.

JP 2009-132895 A

  However, the lubricating film formed by the lubricant proposed in Patent Document 1 does not have sufficient lubricity (hygroscopic resistance) in a high-humidity environment, and furthermore, seizure resistance sufficient for metal processing with high difficulty. Sex cannot be obtained. Therefore, the present invention can form a lubricating film excellent in lubricity (hygroscopic resistance) in a high humidity environment, seizure resistance to metal processing of high difficulty, etc., and has long-term drug stability. An object of the present invention is to provide an excellent water-based lubricant for plastic working of metal materials, a metal material having a lubricating film formed by the water-based lubricant on the surface, and a metal processed product obtained by molding the metal material. .

  As a result of intensive studies to solve the above problems, the present inventors have an aliphatic polycarboxylic acid having a carbon number of 5 or more and 8 or less and a solubility in water at 20 ° C. of 10 g / 100 mL or more. And an alkaline earth metal compound in water. The water-based lubricant has a lubricating film with excellent lubricity (hygroscopic resistance) in a high humidity environment and high seizure resistance against difficult metal processing. It has been found that it can be formed and has excellent drug stability for a long period of time, and the present invention has been completed.

That is, the present invention
(1) Aliphatic polycarboxylic acids and alkaline earths, which are water-based lubricants for plastic working of metal materials, having 5 to 8 carbon atoms and water solubility at 20 ° C. of 10 g / 100 mL or more A water-based lubricant in which a metal compound is mixed in water, or an alkaline earth metal salt of the aliphatic polycarboxylic acid is dissolved and / or dispersed in water;
(2) The aqueous lubricant according to (1), further comprising at least one organic lubricant selected from oil, soap, wax, layered structure amino acid compound, organically modified clay mineral, and extreme pressure agent;
(3) The aqueous lubricant according to (1) or (2) above, which contains at least one selected from water-soluble inorganic acid salts, water-soluble organic acid salts, water-dispersible or water-soluble resins as a binder component. ;
(4) Zinc phosphate, zinc oxide, titanium dioxide, mica, molybdenum disulfide, tungsten disulfide, tin disulfide, graphite fluoride, graphite, boron nitride, calcium hydroxide, calcium carbonate, lime, calcium sulfate and barium sulfate The aqueous lubricant according to any one of the above (1) to (3), further comprising at least one solid lubricant selected from:
(5) The aqueous lubricant according to any one of (1) to (4), wherein the aliphatic polycarboxylic acid is citric acid;
(6) A metal material having on its surface a lubricating film formed by the aqueous lubricant according to any one of (1) to (5) above;
(7) A metal processed product obtained by molding the metal material according to (6) above;
Etc.

  According to the present invention, it is possible to form a lubricating film excellent in lubricity (moisture absorption resistance) in a high humidity environment, seizure resistance to metal processing of high difficulty, etc., and for long-term drug stability. An excellent water-based lubricant for metal material plastic working, a metal material having a lubricant film formed by the water-based lubricant on the surface, and a metal workpiece obtained by molding the metal material can be provided.

It is a figure which shows the evaluation criteria of the burning degree of the test piece which performed the ball ironing process in the upsetting-ball ironing type friction test method with respect to the Example of this invention.

  Hereinafter, the present invention will be described in detail. In addition, the form described below is only an example, and the present invention is not limited to this form.

  The water-based lubricant according to the present invention is excellent in chemical stability for a long period of time, and forms a lubricating film excellent in lubricity (moisture absorption resistance) in a high-humidity environment and seizure resistance against metal processing of high difficulty. Therefore, it is useful for plastic working of metal materials. Here, in the present specification, “long-term drug stability” means maintaining a state in which almost no sedimentation component is generated at 40 ° C. for one month or more as a high-concentration lubricant before dilution, or to a metal material. As a diluted lubricant (actual use concentration) obtained by diluting a high concentration lubricant to form a lubricant film, this means that a state where almost no sediment component is generated for one month or more at the actual use temperature is meant.

  Examples of the metal material for plastic working to which the aqueous lubricant according to the present invention is applied include iron, steel, stainless steel, aluminum, magnesium, copper, and titanium. The shape of the metal material varies depending on the application, and examples thereof include, but are not limited to, a sheet, a bar, a tube, a slab, and the like.

  The aqueous lubricant according to the present invention has an aliphatic polycarboxylic acid having 5 to 8 carbon atoms and a water solubility at 20 ° C. of 10 g / 100 mL or more (hereinafter simply referred to as “aliphatic polycarboxylic acid”). And an alkaline earth metal compound are mixed in water, or the alkaline earth metal salt of the aliphatic polycarboxylic acid is dissolved and / or dispersed in water. In addition to the above, additives such as organic lubricants, binder components, solid lubricants, etc .; liquid adjustment components such as rheology modifiers, surfactants, pH adjusters, etc. may be included as necessary. . Here, the aliphatic polycarboxylic acid means an aliphatic compound having two or more carboxyl groups in the molecule.

  The alkaline earth metal salt of the aliphatic polycarboxylic acid is obtained by adding an alkaline earth metal compound to an aqueous solution in which the aliphatic polycarboxylic acid is dissolved in advance, and mixing the resulting mixture with the alkaline earth metal of the aliphatic polycarboxylic acid. A similar metal salt can be obtained.

  The aliphatic polycarboxylic acid in the aliphatic polycarboxylic acid or its alkaline earth metal salt is not particularly limited as long as it has 5 to 8 carbon atoms and the solubility in water at 20 ° C. is 10 g / 100 mL or more. For example, glutaric acid, citric acid, diacetyl-D-tartaric acid, diacetyl-L-tartaric acid, and the like can be used. Here, the number of carbons is limited to 5 or more. In aliphatic polycarboxylic acids having 4 or less carbon atoms or alkaline earth metal salts thereof, the chemical stability is inferior for a long time, and lubricity in a high humidity environment ( This is because it is not possible to obtain a lubricating film excellent in moisture absorption) and seizure resistance to highly difficult metal processing. On the other hand, the reason why the number of carbon atoms is limited to 8 or less is that, with aliphatic polycarboxylic acids having 9 or more carbon atoms or alkaline earth metal salts thereof, precipitation solidification occurs and an aqueous lubricant cannot be prepared. In addition, the solubility in water at 20 ° C. was limited to 10 g / 100 mL or more, even if an aliphatic polycarboxylic acid having an solubility in water at 20 ° C. of less than 10 g / 100 mL or an alkaline earth metal salt thereof, This is because, as in the case of the aliphatic polycarboxylic acid having a number of 9 or more or its alkaline earth metal salt, precipitation solidification occurs and an aqueous lubricant cannot be prepared.

  The alkaline earth metal compound is not particularly limited as long as it is a compound of beryllium, magnesium, calcium, strontium, barium, or radium. For example, magnesium compounds such as magnesium carbonate, magnesium hydroxide, and magnesium oxide; Calcium compounds such as calcium, calcium hydroxide, and calcium oxide; Among these, it is preferable to use magnesium carbonate or calcium carbonate in terms of excellent reactivity with the aliphatic polycarboxylic acid.

  The aqueous lubricant according to the present invention is, for example, after adding a predetermined aliphatic polycarboxylic acid and an alkaline earth metal compound to water or dissolving an alkaline earth metal salt of a predetermined aliphatic polycarboxylic acid in water. And it can manufacture by adding an additive as needed, after making it disperse | distribute, However, It is not limited to these methods. In addition, you may adjust the pH of an aqueous lubricant to 7 or more using a pH adjuster after manufacture of an aqueous lubricant. As a pH adjuster, alkali components, such as sodium hydroxide and calcium hydroxide, can be used, for example.

  In the production of the aqueous lubricant, the amount of the aliphatic polycarboxylic acid and the alkaline earth metal compound added to water is not particularly limited, but the aliphatic polycarboxylic acid is not particularly limited. The molar ratio of the acid to the alkaline earth metal compound is preferably in the range of 1: 0.2 or more and less than 1: 8, and more preferably in the range of 1: 0.5 or more and less than 1: 2. preferable. By manufacturing within these ranges, it is possible to improve various properties such as lubricity (moisture absorption resistance) in a high humidity environment and seizure resistance to metal processing of high difficulty, as well as long-term drug stability. The sex can be further improved.

  Examples of the organic lubricant include lubricating supplemental components such as oil, soap, wax, layered amino acid compound, organically modified clay mineral, and extreme pressure agent.

  As the oil used as a lubricating supplement component, for example, vegetable oil, synthetic oil, mineral oil and the like can be used, and more specifically, palm oil, castor oil, rapeseed oil, machine oil, turbine oil, ester oil, silicon oil and the like. Can be used.

  The soap is, for example, a metal salt of a fatty acid, and more specifically, has 8 to 22 carbon atoms such as octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, icosanoic acid, oleic acid, stearic acid and the like. Mention may be made of metal salts of saturated or unsaturated fatty acids. Examples of the metal salt include alkali metal salts such as sodium salt and potassium salt, and polyvalent metal salts such as calcium salt, zinc salt, magnesium salt and barium salt.

  Examples of the wax include polyethylene wax, polypropylene wax, carnauba wax, paraffin wax, polytetrafluoroethylene, and the like. Examples of polytetrafluoroethylene include polytetrafluoroethylene having a degree of polymerization of about 1 million to 10 million. In addition, although not similar to wax, an amino acid having a hydrocarbon group having 11 or more carbon atoms or a layered structure amino acid compound which is a derivative thereof, and at least one inorganic cation in the clay mineral is ion-exchanged with an organic cation. Lubricating materials exhibiting lubricating properties such as organically modified clay minerals can also be used. Various waxes and lubricating materials may be used alone or in combination of two or more.

  Examples of the extreme pressure agent include a sulfur-based extreme pressure additive, an organic molybdenum-based extreme pressure additive, a phosphorus-based extreme pressure additive, and a chlorine-based extreme pressure additive. More specifically, melamine cyanurate, sulfurized olefin, sulfurized ester, sulfite, thiocarbonate, chlorinated fatty acid, phosphate ester, phosphite ester, molybdenum dithiocarbamate (MoDTC), molybdenum dithiophosphate (MoDTP), zinc Examples thereof include dithiophosphate (ZnDTP). These extreme pressure agents may be used alone or in combination of two or more.

  As the binder component, for example, a water-soluble inorganic acid salt, a water-soluble organic acid salt, a water-dispersible or water-soluble resin, or the like can be used. These may be used alone or in combination of two or more. The term “water-soluble” as used in the present specification and claims means to dissolve more than 0.1 g in 100 ml of water at 20 ° C.

Examples of the water-soluble inorganic acid salt include acid salts such as sulfuric acid salts, boric acid salts, phosphoric acid salts, tungstic acid salts and silicic acid salts. Examples of salts constituting these acid salts include alkali metal salts (sodium salt, potassium salt, lithium salt, etc.), ammonium salts, amine salts (ethylamine salt, etc.), alkanolamine salts (monoethanolamine salt, diethanolamine salt). Etc.), and an alkali metal salt or an ammonium salt is preferable. Specific examples of water-soluble inorganic acid salts include sodium sulfate, potassium sulfate, lithium borate (such as lithium tetraborate), sodium borate (such as sodium tetraborate), potassium borate (such as potassium tetraborate), Diethanolamine salt of boric acid, sodium silicate, potassium silicate, lithium silicate, sodium metasilicate, sodium phosphate, potassium phosphate, sodium tripolyphosphate, lithium tungstate, sodium tungstate, potassium tungstate, etc. it can. As for the salts of silicic acids, mention is made of those represented by the general formula M ₂ O · nSiO ₂ (wherein n represents the number of 1 to 9, and M represents Na, K, Li or NH ₄ ). Can do. These water-soluble inorganic acid salts may be used alone or in combination of two or more.

  Examples of the water-soluble organic acid salt include, for example, a polycarboxylic acid salt having 3 to 6 carbon atoms which may have a hydroxyl group, malate, succinate, glutarate, citric acid, and the like. It is preferable to use at least one selected from salts and tartrate. Examples of salts constituting these acid salts include alkali metal salts (sodium salt, potassium salt, lithium salt, etc.), ammonium salts, amine salts (ethylamine salt, etc.), alkanolamine salts (monoethanolamine salt, diethanolamine salt). Etc.), and an alkali metal salt or an ammonium salt is preferable. Specific examples of water-soluble organic acid salts include sodium malate, potassium malate, lithium malate, sodium succinate, potassium succinate, lithium succinate, sodium citrate, potassium citrate, lithium citrate, sodium glutarate And potassium glutarate, lithium glutarate, sodium tartrate, potassium tartrate, lithium tartrate and the like. These water-soluble organic acid salts may be used alone or in combination of two or more.

  The water-dispersible or water-soluble resin is not particularly limited as long as it has film-forming properties. For example, an acrylic resin, a phenol resin, a urethane resin, an epoxy resin, a polyester resin, And water-soluble or water-dispersible resins such as isobutylene resins. These water-dispersible or water-soluble resins may be used alone or in combination of two or more.

  The acrylic resin is not particularly limited as long as it is obtained by polymerizing at least one acrylic monomer. Examples of acrylic monomers include alkyls such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, octyl acrylate (for example, C = 1 to 8) (Meth) acrylate; methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, methoxymethyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, ethoxyethyl methacrylate, methoxybutyl acrylate, etc. ) Acrylate; 2-hydroxyethyl (meth) acrylate, 3- Hydroxy lower alkyl (meth) acrylates such as roxypropyl (meth) acrylate; acrylamide; methacrylamide; N-unsubstituted such as N-methylolacrylamide, N-methylolmethacrylamide, N-butoxymethylacrylamide, N-butoxymethylmethacrylamide Alternatively, (meth) acrylamide having a substituted (particularly lower alkoxy substituted) methylol group; phosphonyloxymethyl acrylate, phosphonyloxyethyl acrylate, phosphonyloxypropyl acrylate, phosphonyloxymethyl methacrylate, phosphonyloxyethyl methacrylate, phosphonyloxy Phosphonyloxy lower alkyl (meth) acrylate such as propyl methacrylate; Acrylonitrile; Acrylic acid; Methacrylic acid And the like. In the present invention, the acrylic resin includes a copolymer of at least one of the above acrylic monomers and at least one of other ethylenic monomers such as styrene, methylstyrene, vinyl acetate, vinyl chloride, vinyltoluene, and ethylene. And what contains 30 mol% or more of acrylic monomer units is also included. In the above, “lower” means 1 to 6 carbon atoms.

  Examples of the phenolic resin include those obtained by a reaction of at least one phenol such as phenol, cresol, and xylenol with formaldehyde, and may be either a novolak type resin or a resol type resin. When a novolac resin is used, it is preferable that hexamethylenetetramine or the like is present as a curing agent.

  The urethane resin is not particularly limited as long as it is a synthetic resin having a urethane bond (NHCOO), and a known urethane resin can be used. Examples thereof include those obtained by a polyaddition reaction of a polyisocyanate compound having two or more isocyanate groups and a polyol having two or more active hydrogen groups. Examples of the polyol include polyester polyol and polyether polyol.

  Examples of the polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1, Low molecular weight (molecular weight 1000 or less) polyols such as 4-butylene glycol, 3-methylpentanediol, hexamethylene glycol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, glycerin, succinic acid, glutaric acid, adipic acid, Obtained by reaction with polybasic acids such as sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, hexahydrophthalic acid, etc. And a polyester compound having a hydroxyl group at the end.

  Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1 , 4-butylene glycol, 3-methylpentanediol, hexamethylene glycol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, glycerin and other low molecular weight polyols (molecular weight 1000 or less) or their high ethylene oxide and / or propylene oxide content Adducts (two or more adducts); polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol; polycaprolactone polio Le; polyolefin polyols; polybutadiene polyols; and the like.

  Examples of polyisocyanate compounds include aliphatic, alicyclic or aromatic polyisocyanates. Specifically, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, hydrogenated xylylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4′-dicyclohexylmethane diisocyanate, isophorone Diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4, 4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, phenylene diisocyanate, xylylene diisocyanate It can be mentioned tetramethylxylylene diisocyanate and the like.

  Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resins obtained by reacting bisphenols, particularly bisphenol A (2,2-bis (4′-hydroxyphenyl) propane) and epichlorohydrin. Can be mentioned. In addition, novolak type epoxy resin in which phenolic hydroxyl group of phenol novolak resin is glycidyl ether, glycidyl ester of aromatic carboxylic acid, peracid epoxy type epoxy resin in which double bond of ethylenically unsaturated compound is epoxidized with peracid, etc. Can be mentioned. Furthermore, what added ethylene oxide or propylene oxide to the resin frame | skeleton of the said various epoxy resin, the glycidyl ether type epoxy resin of a polyhydric alcohol, etc. can be mentioned. Among these, it is preferable to use a bisphenol A type epoxy resin.

  Examples of the polyester resin include maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, isophthalic acid, terephthalic acid, trimellitic acid , Polybasic acids such as trimesic acid, pyromellitic acid, naphthalene dicarboxylic acid, ethylene glycol, diethylene glycol, trimethylolpropane, neopentyl glycol, 1,4-CHDM (cyclohexanedimethanol), 1,6-hexanediol, etc. A condensation resin obtained by condensing a polyol; a polybasic acid and a polyol such as a polymer polyol, a polycaprolactone polyol, a polycarbonate diol, a polybutadiene polyol, neopentyl glycol, or methylpentadiol. Engaged thereby condensation resin; and the like. Also, a water-based resin in which a monomer having three or more carboxyl groups such as trimellitic acid or pyromellitic acid is used as a part of the monomer, and the unreacted carboxylic acid is neutralized with an alkali to be solubilized or dispersed in water. Alternatively, an aqueous resin that is solubilized or dispersed in water using a sulfonated monomer such as sulfophthalic acid as a part of the monomer can also be used.

  Examples of the isobutylene resin include a copolymer of isobutylene and maleic anhydride. In addition, although the maleic anhydride part of the copolymer may be modified with ammonia or imidized, it is preferable to use a copolymer having a number average molecular weight of 10,000 or more from the viewpoint of film formation ( GPC method (measured value by Gel Permeation Chromatography).

  Examples of solid lubricants (including powdered ones) include zinc phosphate, zinc oxide, titanium dioxide, mica, molybdenum disulfide, tungsten disulfide, tin disulfide, graphite fluoride, graphite, boron nitride, Examples thereof include calcium hydroxide, calcium carbonate, lime, calcium sulfate, and barium sulfate. These solid lubricants may be used alone or in combination of two or more.

  Examples of the rheology modifier include an aqueous polymer and an inorganic viscosity modifier. Examples of the aqueous polymer include hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylic acid amide, sodium polyacrylate, sulfonic acid-modified sodium polyacrylate, polyvinyl pyrrolidone, and polyvinyl alcohol. Examples of the inorganic viscosity modifier include silica, bentonite, kaolin, mica, montmorillonite, hectorite and the like. The inorganic viscosity modifier may be a natural product or a synthetic product. These rheology modifiers may be used alone or in combination of two or more. By blending the rheology modifier in the aqueous lubricant according to the present invention, the components dispersed in the aqueous lubricant can be stabilized, and the coating characteristics (for example, liquid viscosity) on the metal material can be improved. Can be achieved.

  Examples of the surfactant include nonionic surfactants, anionic surfactants, amphoteric surfactants, and cationic surfactants. If necessary, the molecular structure, HLB, etc. May be selected as appropriate. These may be used alone or in combination of two or more. By blending a surfactant with the aqueous lubricant according to the present invention, it is possible to improve the cleaning effect and wettability of the surface of the metal material. Since this effect is general, it is not shown in the examples.

  Next, the metal material and the metal processed product according to the present invention will be described. The metal processed product according to the present invention can be obtained by molding the metal material. Examples of the forming method include a method of forming the metal material according to the present invention by heat, pressure, mechanical force, or the like using a mold, a tool, or the like. The metal material according to the present invention can be obtained by forming a lubricating film on the surface with the aqueous lubricant. More specifically, it can be produced by a method comprising a step of bringing a water-based lubricant into contact with the surface and a step of drying the surface in contact with the water-based lubricant. Before performing the step of bringing the aqueous lubricant into contact, the surface of the target metal material is washed (usually using an alkaline detergent), washed with water after washing, and descaling (shot blast or acid such as hydrochloric acid). The surface may be cleaned by performing all or part of pre-treatment such as washing, etc.) and water washing after descaling. As a result, a good lubricating film can be obtained in the subsequent step (step of bringing the aqueous lubricant into contact). In addition, when the oxide scale does not adhere or when it is used for an application requiring the oxide scale, descaling and washing with water after descaling may be omitted. These pretreatments can be performed by conventional methods.

  Moreover, before performing the process which contacts the aqueous | water-based lubricant which concerns on this invention, you may perform a chemical conversion treatment, a base treatment, etc. as needed. Examples of the chemical conversion treatment include iron phosphate chemical conversion treatment, zinc phosphate chemical conversion treatment, zinc phosphate calcium chemical conversion treatment, iron oxalate chemical conversion treatment, aluminum fluoride chemical conversion treatment, and zircon oxide chemical conversion treatment. As the ground treatment, for example, a solid lubricant is mechanically applied by a method of contacting and drying a ground treatment agent containing an alkali metal salt such as boric acid, silicic acid, sulfuric acid, phosphoric acid, tungstic acid, or a projection method such as blasting. The method of coating etc. can be mentioned.

  As a method of bringing the aqueous lubricant or the base treatment agent into contact, for example, a known method such as dipping, spraying, pouring or brushing can be applied. The contact with the aqueous lubricant or the surface treatment agent is not particularly limited as long as the surface is sufficiently covered with the lubricant or the surface treatment agent. Drying of the surface of the metal material in contact with the aqueous lubricant or the base treatment agent can be performed by a known method such as heat drying or air drying. Although it does not restrict | limit especially as drying temperature and time, It is preferable to carry out for about 10 second-about 60 minutes with the ultimate board temperature of 60 to 150 degreeC.

The mass of the lubricating film formed by the aqueous lubricant according to the present invention may be adjusted as appropriate according to the application such as the form of processing and the degree of difficulty. From the viewpoint of preventing seizure, it is usually 1 g / m ² or more with a dry film. It is preferable that it is in the range of 3-50 g / m < ² >. The aqueous lubricant of the present invention may be applied not only to the surface of the metal material but also to the surface of the mold in addition to the surface of the metal material. In the lubricating film, it is presumed that the aliphatic polycarboxylic acid and the alkaline earth metal form a salt. Here, the mass of the alkaline earth metal contained in the lubricating film is preferably 1% by mass or more in terms of solid content in the dried lubricating film, but from the viewpoint of improving the seizure resistance. The content is more preferably 5% by mass or more, and particularly preferably 10% by mass or more. The existing mass of the alkaline earth metal in the dried lubricating film can be calculated by measuring a metal material having the lubricating film with fluorescent X-rays.

  A protective layer may be formed on the upper layer of the lubricating film formed by the aqueous lubricant according to the present invention for the purpose of supplementing lubricity and rust prevention. Examples of components used for forming the protective layer include oil, soap, metal soap, wax and the like, and one or more of them may be used. The protective layer can be formed by applying these components. In addition, the protective layer may be comprised in the form of the composite layer which hold | maintained the said component in the binder component.

  The present invention will be described more specifically together with its effects by giving examples of the present invention together with comparative examples. In addition, this invention is not restrict | limited by these Examples.

(1) Manufacturing method of aqueous | water-based lubricant The structural component (the following a component-f component) of the various aqueous | water-based lubricant which concerns on a following example and a comparative example is shown below. Table 1 shows the carbon number of various components a and the solubility in water (20 ° C.). Various water-based lubricants are based on the compositions shown in Tables 2 and 3, and each component of various water-based lubricants (any one of the following a1 to a8 and any of b1 to b6, if necessary, c1 to c2, d1 to d3, e1 to e2, and f1 to f4) were sequentially added to water while stirring, and the pH was adjusted with sodium hydroxide or sodium carbonate. In addition, the numerical value of each component in Table 2 and 3 means the mass% of each addition component on the basis of the mass of all the added components.

(2) Constituent component of aqueous lubricant <aliphatic polycarboxylic acid: component a>
a1: glutaric acid a2: citric acid a3: butanetetracarboxylic acid a4: oxalic acid a5: tartaric acid a6: malic acid a7: suberic acid a8: 1,10-decanedicarboxylic acid

<Metal compound to be reacted with aliphatic polycarboxylic acid: component b>
b1: Magnesium carbonate b2: Calcium carbonate b3: Calcium hydroxide b4: Strontium carbonate b5: Sodium hydroxide b6: Lithium hydroxide

<Lubricating component: c component>
c1: Polyethylene wax c2: Calcium stearate

<Binder component: d component>
d1: potassium tetraborate d2: sodium citrate d3: isobutylene resin: copolymer of isobutylene and maleic anhydride (molecular weight 90,000)

<Solid lubricant: e component>
e1: Zinc phosphate aqueous dispersion (Nippon Parkerizing Co., Ltd.)
e2: Organically modified synthetic mica: distearyldimethylammonium chloride supported between hectorite layers

<Viscosity modifier: f component>
f1: hydroxyethyl cellulose f2: carboxymethyl cellulose f3: sulfonic acid-modified sodium polyacrylate f4: polyvinyl alcohol

(Table 1) Carbon number of component a and solubility in water

(3) Formation of Lubricating Film Formation of the lubricating film on the plastic processing performance evaluation test pieces using the aqueous lubricants of Examples 1 to 29 and Comparative Examples 1 to 8, respectively, is performed by applying the above test pieces to various aqueous lubricants. It was performed by dip coating and then drying. In addition, the solid content concentration and dip coating time of various water-based lubricating coatings were appropriately adjusted so that the amount of coating formed was about 5 g / m ² .

(Table 2)

(Table 3)

(4) Evaluation Long-term drug stability:
Evaluation before dilution was performed by filling 100 mL of various aqueous lubricants having a high concentration (solid content concentration of 20% by mass) into a transparent plastic container, and keeping it still in a constant temperature bath at 40 ° C. for 1 day, 1 week or 1 month. It was carried out by storing and measuring the degree of dispersion of the aqueous lubricant. In addition, the evaluation after dilution was carried out by filling 100 mL of various aqueous lubricants having an actual use concentration (solid content concentration of 8% by mass) into a transparent plastic container, and in a constant temperature bath at 60 ° C. for 1 day, 1 week or 1 It was carried out by storing it for a month and measuring the degree of dispersion of the aqueous lubricant. The dispersity (%) of the water-based lubricant was obtained as a ratio of the dispersity by measuring the height from the bottom surface of the container to the phase separation surface when the total amount of the water-based lubricant was 100%. If the evaluation result was “Δ” or higher, it was judged that there was no concern about sedimentation and solidification, and the performance was at a practical level.

<Evaluation criteria>
Long term drug stability:
◎: Dispersion is 80% or more even when stored for 1 month, and no sedimentation solidification is observed at the bottom of the container ○: Dispersity is 50% or more and less than 80% even if stored for 1 week to 1 month, No sedimentation or solidification is observed at the bottom of the container. Δ: Dispersion is less than 50% by storage for 1 day to 1 week, but no sedimentation or solidification is observed at the bottom of the container. % And sedimentation solidification is observed at the bottom of the container

Lubricity evaluation by pull-out test (lubricity, moisture absorption resistance, clogging resistance):
In order to evaluate the lubrication performance of the lubricating film formed with various water-based lubricants for metal material plastic working, the steel wire with the lubricating film formed is drawn, and the lubricity during the drawing process In addition, moisture absorption resistance, clogging resistance and the like were evaluated according to the following evaluation methods and evaluation criteria. The wire drawing was performed by drawing the steel wire using an R die (φ11.85 mm). As the steel wire, SCM435 steel wire (φ 13.00 mm, length 1.5 m) was used. The surface treatment of the steel wire (including the formation of the lubricating film) was performed by the following steps i to viii. In the above evaluation results, “Δ” or more was judged to have a practical level of performance.
i) Alkaline degreasing (Fine Cleaner E6400 (Nihon Parkerizing Co., Ltd.), 20 g / L, 60 ° C., 20 minutes, immersion)
ii) Washing with water (industrial water, 20 ° C., 30 seconds, immersion)
iii) Scale removal pickling (18% hydrochloric acid solution, 20 ° C., 20 minutes, immersion)
iv) Washing with water (industrial water, 20 ° C., 30 seconds, immersion)
v) Neutralization (preparene 27 (manufactured by Nihon Parkerizing Co., Ltd.), 3 g / L, 20 ° C., 30 seconds, immersion)
vi) Formation of lubricating film with various water-based lubricants (actual use concentration, 60 ° C., 30 seconds, immersion)
vii) Drying (100 ° C., 5 minutes)
viii) The steel wire material to be subjected to moisture absorption resistance evaluation was allowed to stand for 24 hours in a room of 30 ° C. × 80% RH after the step of vii).

<Evaluation method>
Lubricity without moisture absorption:
After the step vii), the steel wire was returned to room temperature and then drawn, and the lubricity was evaluated according to the following evaluation criteria.
Hygroscopic resistance (lubricity after moisture absorption):
After the step viii), wire drawing was performed using a steel wire, and moisture absorption resistance was evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: The lubricity is extremely good, and no seizure or wrinkle is observed on the steel wire or R die. O: The lubricity is good and the steel wire or the R die has an area ratio of less than 10%. Δ: The lubricity is standard, and the surface of the steel wire and the R die have wrinkles and adhesion in the area ratio of 10% or more and less than 25%. ×: The lubricity decreases. The surface of the steel wire and the R die have wrinkles and adhesion within an area ratio of 25% or more, or the steel wire is not lubricated and breaks during wire drawing.

<Evaluation method>
Anti-clogging resistance:
During metal processing, the amount of residue generated in the lubricant film is large, and the residue may easily clog the R die. Therefore, the occurrence of residue when wire drawing was performed under conditions without moisture absorption was visually confirmed, and the resistance to residue clogging was evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: Most of residue is not observed (the amount of residue generated is less than 10% of the amount of the lubricant film)
○: The generation of debris is small, and the generated debris is not viscous and is not adsorbed to the R die (the amount of debris generated is 10% or more and less than 30% of the amount of the lubricant film)
Δ: A large amount of debris is generated and the R die is easily clogged (the amount of debris generated is 30% or more and less than 50% of the amount of the lubricant film), or the generated debris is at least because the debris is viscous. Adsorbed on the die (the amount of waste generated is 10% or more and less than 30% of the lubricating film)
X: The amount of waste generated is very large and the R die is easily clogged (the amount of generated waste is 50% or more of the amount of the lubricating film), or the residue is adhering to the R die because it is viscous ( (The amount of waste generated is 30% or more of the lubricating film)

Highly difficult workability (seizure resistance, moisture absorption resistance):
Processing with high difficulty was performed, and seizure resistance was evaluated. Evaluation of machining performance on high difficulty level is disclosed in the reference (Akiaki Takahashi, Hitoshi Hirose, Shinobu Omiyama, Shigoshi Wang: Proceedings of the 62nd Japan Plastic Working Federation, (2011), 89-90) -Only the ironing process in the ball ironing friction test was performed. The evaluation before moisture absorption was carried out after applying various water-based lubricants to the surface of the barrel-shaped test piece and then forming a lubricating film on the surface of the test piece by drying in a hot air oven at 100 ° C. Evaluation of moisture absorption resistance was carried out after leaving a test piece having a lubricating film formed on the surface in a constant temperature and humidity tester of 30 ° C. × 80% RH for 24 hours. In addition, all of the adhesion amount of the formed film was around 5 g / m ² . The barrel-shaped test piece is upset to a upsetting rate of 45% in a state where both end faces are constrained so as not to spread using a cylindrical steel material (S10C) having a diameter of 14 mm and a length of 32 mm. What was produced in was used. The surface roughness in the vicinity of the most protruding portion on the side surface of the test piece was about Rz 9 μm. The upper and lower end surfaces of the barrel-shaped test piece on which the lubricating film is formed are sandwiched between molds, and the ironing process is performed using three ball-shaped molds (SUJ-2 bearing balls with a diameter of 10 mm) for the most protruding part. went. The ironing process is a strong process in which the maximum surface area expansion of the ironing part exceeds 200 times, and is an extremely difficult process.

<Evaluation criteria>
The evaluation of seizure resistance after processing at a high degree of difficulty was performed according to the evaluation criteria shown in FIG. 1 after confirming the degree of seizure in the latter half of the ironing process with a large surface area expansion.

Corrosion resistance:
Applying various water-based lubricants at the actual use concentration to degreased and washed carbon steel S45C material, and drying with hot air, test pieces for corrosion resistance evaluation (film adhesion mass after volatilization of water is 5 g / m ² ), respectively Produced. The corrosion resistance of each test piece was evaluated according to the following evaluation criteria by measuring the area of the generated rust after leaving the test piece in a constant temperature and humidity chamber at a temperature of 30 ° C. and a humidity of 80% for 120 hours. When the evaluation result is “◯” or more, it can be said that excellent corrosion resistance is exhibited even in a wet environment.

<Evaluation criteria>
A: Rust area ratio is less than 10% B: Rust area ratio is 10% or more and less than 20% Δ: Rust area ratio is 20% or more and less than 50% ×: Rust area ratio is 50% or more

  The above evaluation results are shown in Table 4. As is apparent from Table 4, Examples 1 to 29, which are water-based lubricants for metal material plastic working of the present invention, were practical levels in all evaluation items. On the other hand, Comparative Examples 1 and 2 using an alkali metal salt of an aliphatic polycarboxylic acid, which is outside the scope of the present invention, have none of seizure resistance, moisture absorption resistance, clogging resistance, and corrosion resistance at practical levels. It was. In Comparative Example 3, which was outside the scope of the present invention using an alkaline earth metal without using an aliphatic polycarboxylic acid, the drug stability did not reach a practical level for a long time. Further, in Comparative Examples 4, 5, and 6 in which the carbon number of the aliphatic polycarboxylic acid is outside the range of the present invention, seizure resistance, moisture absorption resistance, and corrosion resistance were not at practical levels. In Comparative Example 6, the drug stability did not reach a practical level for a long time. Comparative Example 7 in which the solubility of the aliphatic polycarboxylic acid in water is outside the scope of the present invention, and Comparative Example 8 in which the carbon number of the aliphatic polycarboxylic acid and the solubility in water are outside the scope of the present invention, In addition, an alkaline earth metal salt of an aliphatic polycarboxylic acid could not be formed, and an aqueous lubricant could not be prepared.

(Table 4)

Claims (7)

A water-based lubricant for metal material plastic working,
An aliphatic polycarboxylic acid having 5 to 8 carbon atoms and a solubility in water at 20 ° C. of 10 g / 100 mL or more and an alkaline earth metal compound are mixed in water, or the aliphatic polycarboxylic acid An aqueous lubricant in which an alkaline earth metal salt of an acid is dissolved and / or dispersed in water.   The aqueous lubricant according to claim 1, further comprising at least one organic lubricant selected from oil, soap, wax, layered structure amino acid compound, organically modified clay mineral, and extreme pressure agent.   The aqueous lubricant according to claim 1 or 2, comprising at least one selected from water-soluble inorganic acid salts, water-soluble organic acid salts, water-dispersible or water-soluble resins as a binder component.   Selected from zinc phosphate, zinc oxide, titanium dioxide, mica, molybdenum disulfide, tungsten disulfide, tin disulfide, graphite fluoride, graphite, boron nitride, calcium hydroxide, calcium carbonate, lime, calcium sulfate and barium sulfate The aqueous lubricant according to any one of claims 1 to 3, further comprising at least one solid lubricant.   The aqueous lubricant according to any one of claims 1 to 4, wherein the aliphatic polycarboxylic acid is citric acid.   The metal material which has the lubricating film formed with the water-based lubricant of any one of Claims 1-5 on the surface.   A metal processed product obtained by molding the metal material according to claim 6.