Lubricant composition for plastic working and method for producing metal material with lubricant coating

Abstract

To provide a lubricant composition for plastic working that enables processing without a chemical conversion coating even in severe plastic working such as forging of steel or stainless steel and that forms a coating exhibiting excellent working lubricity even when exposed to a moisture-absorbing environment.SOLUTION: A lubricant composition for plastic working comprises a polymer A having a polyamide chain and a polyalkylene oxide chain within one molecule, and one or more inorganic substances B selected from a smectite clay mineral and an inorganic oxide represented by aMxOy-bSiO2-cH2O, where a, b, and c are rational numbers satisfying 0≤a≤3, 0≤b≤4, 0≤c≤5, and 1≤a+b, x and y satisfy x=2 and y=1, or x=y=1, or x=2 and y=3, and M is Mg or Al.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lubricant composition for plastic working used during plastic working of metal materials such as steel and stainless steel, and a method for producing a metal material with a lubricating coating. [Background technology]

[0002] During plastic processing of metal materials such as steel and stainless steel, a lubricating film is formed on the metal surface to prevent seizure and galling. These lubricating films can be formed by physically attaching a lubricant to the metal surface, or by applying a lubricant to a chemical conversion coating formed on the metal surface through a chemical reaction. The former has generally been used for light processing. On the other hand, the latter has a two-layer structure consisting of a chemical conversion coating as a carrier coating and a lubricating coating, and exhibits extremely high seizure resistance. Therefore, it has been used in a wide range of plastic processing fields, such as wire drawing, pipe drawing, and forging. In particularly severe plastic processing fields, a phosphate or oxalate coating is often used as a base layer, followed by the application of a lubricant.

[0003] Lubricants used to form a lubricating film on a chemical conversion coating can be divided into two types depending on their method of use. One type is physically adhered to the chemical conversion coating, and the other is reacted with the chemical conversion coating. Examples of the former lubricants include those based on mineral oil, vegetable oil, or synthetic oil, to which an extreme-pressure agent has been added, and those in which solid lubricants such as graphite or molybdenum disulfide are dissolved in water with a binder component, applied, and dried. These types of lubricants that physically adhere to the chemical conversion coating have the advantage of being easily applied by spraying or immersion and requiring little liquid management, but due to their low lubricity, they are often used for relatively light lubrication. On the other hand, examples of lubricants that react with the chemical conversion coating include reactive soaps such as sodium stearate, which are particularly suitable for applications requiring high lubricity (processing lubrication).

[0004] In recent years, a technology has been proposed that allows a lubricating film to be formed using a single agent. For example, Patent Document 1 proposes a water-soluble lubricant for plastic working that contains a water-soluble polymer compound consisting of a water-soluble polyether compound and a water-soluble polyester compound, and an inorganic metal salt. This technology makes it possible to obtain a lubricating film with processing lubricity equivalent to that of a lubricant that has undergone chemical conversion treatment, using a simple processing method. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-177000 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the use of reactive soaps that involve chemical reactions requires management of the liquid composition and bath temperature to control the chemical reaction, and requires a two-stage process to form a chemical conversion coating and a lubricating coating. Furthermore, the lubricating coating disclosed in Patent Document 1 also leaves room for improvement in terms of its processing lubrication performance. It can be particularly difficult to use when the treated coating is exposed to a hygroscopic environment before or during processing.

[0007] An object of the present invention is to provide a lubricant composition for plastic working that can be used in severe plastic working such as forging of steel, stainless steel, etc. without a chemical conversion coating, and that can provide a coating that exhibits excellent working lubricity even when exposed to a hygroscopic environment. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that a lubricant composition for plastic working containing a specific polymer and a predetermined inorganic substance absorbs less moisture than conventional lubricants for plastic working, even in a hygroscopic environment, has excellent lubricating properties for processing, and is particularly suitable as a lubricant for plastic working of metals such as steel and stainless steel, and have completed the present invention.

[0009] The present invention provides, by way of example, the following lubricant composition for plastic working and a method for producing a metal material with a lubricating coating. [1] a polymer A having a polyamide chain and a polyalkylene oxide chain in one molecule; Smectite clay minerals and aM x O y and one or more inorganic substances B selected from inorganic oxides represented by the formula: ·bSiO2·cH2O (wherein a, b, and c are rational numbers satisfying 0≦a≦3, 0≦b≦4, 0≦c≦5, and 1≦a+b; x and y are either x=2 and y=1, or x=y=1, or x=2 and y=3; and M is Mg or Al). [2] The lubricant composition for plastic working according to [1], wherein the polymer A is water-insoluble. [3] The lubricant composition for plastic working according to [1] or [2], wherein the inorganic substance B is water-insoluble. [4] The polymer A has a peak intensity of 1580 to 1660 cm in infrared spectroscopy (IR). -1 Peak α and 1060-1150 cm -1 and the peak α has a peak intensity α A The peak intensity β of the peak β relative to A The ratio β A / α A The lubricant composition for plastic working according to any one of [1] to [3], wherein is 0.3 to 2.0. [5] The mass M of the polymer A A Mass M of the inorganic substance B B Ratio of M B / M A The lubricant composition for plastic working according to any one of [1] to [4], wherein is 0.01 to 1.5. [6] The lubricant composition for plastic working according to any one of [1] to [5], further comprising a water-soluble inorganic salt C (excluding inorganic substance B). [7] The lubricant composition for plastic working according to [6], wherein the water-soluble inorganic salt C comprises one or more selected from phosphates, condensed phosphates, silicates, borates, molybdates, and tungstates. [8] The mass M of the polymer A A and the mass M of the inorganic substance B B The mass M of the water-soluble inorganic salt C relative to the total C Ratio of M C / (M A +M B ) is 0.01 to 0.3. [9] The lubricant composition for plastic working according to any one of [1] to [8], further comprising a water-soluble polymer compound D (excluding polymer A).

[10] The lubricant composition for plastic working according to [9], wherein the water-soluble polymer compound D contains one or more selected from a urethane-based resin, a polycarboxylic acid-based resin, a polyvinyl alcohol-based resin, a polyether-based resin, and a polysaccharide.

[11] The mass M of the polymer A A and the mass M of the inorganic substance B B The mass M of the water-soluble polymer compound D relative to the total D Ratio of M D / (M A +M B ) is 0.01 to 0.25.

[12] The lubricant composition for plastic working according to any one of [1] to

[11] , wherein the softening point of the polymer A is 100 to 200°C.

[13] A method for producing a metal material with a lubricating coating, comprising the step of bringing the lubricant composition for plastic working according to any one of [1] to

[12] into contact with a metal material. [Effects of the Invention]

[0010] According to the lubricant composition for plastic working according to one embodiment of the present invention, by containing a specific polymer A, a predetermined inorganic substance B, and, if necessary, a water-soluble inorganic salt C or a water-soluble polymer compound D, the following effects can be obtained. (1) The lubricant composition for plastic working according to one embodiment of the present invention has excellent processing lubricity, and can be used to form a lubricating film on the surface of metal materials such as steel, stainless steel, aluminum, titanium, etc., when performing cold plastic working such as forging, wire drawing, pipe drawing, pressing, etc. Furthermore, even in severe plastic working such as forging of steel, stainless steel, etc., processing is possible without a chemical conversion coating. (2) Furthermore, a lubricating film formed using the lubricant composition for plastic working according to one embodiment of the present invention has excellent working performance even when exposed to a hygroscopic environment. [Brief explanation of the drawings]

[0011] [Figure 1] The evaluation criteria for evaluating the seizure resistance after ironing are shown below. DETAILED DESCRIPTION OF THE INVENTION

[0012] The lubricant composition for plastic working of the present invention will be described in more detail below, but is not limited to the embodiments according to the present disclosure. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits, and "X to Y" means at least X and at most Y.

[0013] <Polymer A> A lubricant composition for plastic working according to one embodiment of the present invention contains a polymer A (hereinafter simply referred to as "polymer A") containing a polyamide chain and a polyalkylene oxide chain in one molecule. The presence of a polyamide chain as a hard segment and a polyalkylene oxide chain as a soft segment in one molecule significantly improves working lubricity. Polymer A has the role of imparting slip properties and followability to a lubricating coating.

[0014] Polymer A may be either water-soluble or water-insoluble, but if it is water-insoluble, moisture absorption is suppressed even when it is exposed to a hygroscopic environment, which provides the advantage of maintaining even better processing lubricity. "Water-insoluble" refers to the following: Polymer A is added to pure water at 25°C so that the solid content is 10% by mass; this is heated and dried in an oven at 60°C; this is then added again to pure water at 25°C so that the solid content is 10% by mass; the mixture is left to stand for one day with stirring; the mixture is filtered through 5A filter paper; and the dried mass of the residue remaining on the filter paper is weighed. The weight loss from the initial polymer is measured; if the weight loss is 20% or less, the polymer is considered water-insoluble. On the other hand, if the weight loss is more than 20%, the polymer is considered water-soluble. The appropriate sample size is approximately 1 g.

[0015] The polyamide chain is not particularly limited, and examples thereof include polyamide 6, polyamide 46, polyamide 49, polyamide 410, polyamide 412, polyamide 66, polyamide 69, polyamide 610, polyamide 611, polyamide 612, polyamide 1010, polyamide 66 / 6, polyamide 6 / 66 / 12, polyamide 6 / 12, polyamide 11, polyamide 12, polyamide 912, polyamide 1212, polyamide 62, polyamide 92, polyamide 102, and polyamide 122.

[0016] The polyalkylene oxide chain is not particularly limited, but may have an alkylene group with a linear structure or an alkylene group with a branched structure. The number of carbon atoms in the alkylene group is also not particularly limited, but may be C2 to C20, C2 to C18, or C2 to C16. Specific examples of the polyalkylene oxide chain include, but are not limited to, polymethylene oxide chains, polyethylene oxide chains, polypropylene oxide chains, and polybutylene oxide chains. The number of repeating units in the polyalkylene oxide chain is preferably in the range of 3 to 100, and more preferably in the range of 15 to 50.

[0017] Polymer A is not particularly limited as long as it has a polyamide chain and a polyalkylene oxide chain in one molecule, and may be a synthetically prepared polymer or a commercially available product. The polymerization mode of the polyamide chain and the polyalkylene oxide chain is not particularly limited, and may be block copolymerization, random copolymerization, or graft copolymerization.

[0018] Polymer A exhibits a peak intensity of 1580-1660 cm in infrared spectroscopy (IR). -1 (hereinafter referred to as "peak α") and the absorption peak at 1060-1150 cm -1 It is preferable that the compound has an absorption peak (hereinafter referred to as "peak β") of α = 0. Peak α is mainly due to the C=O stretching of an amide group. Peak β is mainly due to the CO stretching of an aliphatic ether. The peak intensity α of peak α is A Peak intensity β of peak β A The ratio β A / α A is preferably in the range of 0.3 to 2.0, more preferably in the range of 0.6 to 1.3, even more preferably in the range of 0.65 to 1.15, still more preferably in the range of 0.7 to 1.10, and particularly preferably in the range of 0.8 to 1.10. A / α A When the value is within the above range, a lubricating coating having excellent moisture absorption resistance and flexibility can be obtained. In this specification, infrared spectroscopy (IR) is performed using a diamond crystal attenuated total reflection (ATR) method at an incident angle of 45°. In the examples, a Fourier transform infrared spectrometer, Spectrum Two (manufactured by PerkinElmer), was used.

[0019] The softening point of polymer A is preferably 100°C to 200°C, more preferably 120°C to 180°C, and even more preferably 140°C to 170°C. In this specification, the softening point is measured using a rigid pendulum-type physical property tester RPT-3000W (manufactured by A&D Co., Ltd.) (used in the Examples) or an equivalent tester. The measurement conditions are as follows: a round-bar cylinder edge pendulum (RBP-006) is used as the pendulum, and the temperature is raised from 25 to 200°C at a rate of 5°C / min. In this specification, the change in the amplitude of the pendulum is recorded, and the temperature at which the logarithmic decrement reaches its maximum is taken as the softening point.

[0020] The content of polymer A relative to the solid content of the lubricant composition for plastic working is not particularly limited, but from the viewpoint of the processing lubrication of the lubricating coating, it is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. Furthermore, from the viewpoint of the seizure resistance of the lubricating coating, the content of polymer A relative to the solid content of the lubricant composition for plastic working is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less. That is, the content of polymer A relative to the solid content of the lubricant composition for plastic working is, for example, preferably 10 to 95% by mass, more preferably 15 to 90% by mass, and even more preferably 20 to 80% by mass or less. One type of polymer A may be used alone, or two or more types may be used in combination. When two or more types of polymer A are used, the above-mentioned "% by mass" refers to the total amount. The solid content of the lubricant composition for plastic working is the portion of the lubricant composition for plastic working excluding the solvent or dispersion medium such as water, and is the total mass of components that are in a solid state at a temperature of 25°C.

[0021] <Inorganic substance B> The lubricant composition for plastic working according to one embodiment of the present invention comprises a smectite clay mineral and aM x O yThe coating contains one or more inorganic substances B (hereinafter simply referred to as "inorganic substance B") selected from inorganic oxides represented by the formula bSiO2 cH2O (where a, b, and c are rational numbers satisfying 0≦a≦3, 0≦b≦4, 0≦c≦5, and 1≦a+b; x and y are either x=2 and y=1, or x=y=1, or x=2 and y=3; and M is Mg or Al). The inorganic substance B has the role of imparting toughness to the coating.

[0022] Examples of smectite clay minerals include, but are not limited to, smectite and laponite. Examples of inorganic oxides include silica represented by SiO2 (a=0, b=1, c=0), magnesia represented by MgO (a=1, b=0, c=0, x=y=1), alumina represented by Al2O3 (a=1, b=0, c=0, x=2, y=3), forsterite represented by 2MgO·SiO2 (a=2, b=1, c=0, x=y=1), and 3Al2O3·2SiO2 (a=3, b=1). Examples of inorganic substance B include, but are not limited to, mullite represented by the formula 3MgO·4SiO2·H2O (a=3, b=4, c=1, x=y=3), kaolin represented by Al2O3·2SiO2·2H2O (a=1, b=2, c=2, x=2, y=3), and talc represented by the formula 3MgO·4SiO2·H2O (a=3, b=4, c=1, x=y=1). Preferred inorganic substance B is smectite, laponite, magnesia, alumina, and silica.

[0023] The inorganic substance B may be either water-soluble or water-insoluble, but if it is water-insoluble, moisture absorption is suppressed even when exposed to a hygroscopic environment, which provides the advantage of maintaining even better processing lubricity. Whether or not the inorganic substance B is water-insoluble is determined by the same method and criteria as for the polymer A.

[0024] The content of inorganic substance B relative to the solid content of the lubricant composition for plastic working is not particularly limited, but from the viewpoint of the seizure resistance of the lubricating coating, it is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass. Furthermore, from the viewpoint of suppressing the processing load, the content of inorganic substance B relative to the solid content of the lubricant composition for plastic working is preferably 55% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass. That is, the content of inorganic substance B relative to the solid content of the lubricant composition for plastic working is, for example, preferably 1 to 55% by mass, more preferably 3 to 50% by mass, and even more preferably 5 to 45% by mass. One type of inorganic substance B may be used alone, or two or more types may be used in combination. When two or more types of inorganic substance B are used, the above-mentioned "% by mass" refers to the total amount.

[0025] The mass M of polymer A contained in the lubricant composition for plastic working A Mass M of inorganic substance B B Ratio of M B / M A is preferably 0.01 to 1.5, more preferably 0.03 to 1.0, even more preferably 0.05 to 0.8, and particularly preferably 0.1 to 0.5. B / M A When the value of the moisture absorption coefficient is within the above range, the moisture absorption resistance and the lubricity during processing are excellent.

[0026] The average particle size of inorganic substance B is not particularly limited as long as the intended effect of the present invention can be obtained, but is preferably 2 nm to 50 μm, more preferably 5 nm to 10 μm, and even more preferably 10 nm to 1 μm. When the average particle size of inorganic substance B is within the above range, it is uniformly dispersed in the lubricant components, making it easier to obtain processing lubrication. The average particle size can be the average value when the particle sizes (meaning the circle equivalent diameter) of 20 or more inorganic substances B are measured using an electron microscope.

[0027] The specific surface area of ​​the inorganic substance B is not particularly limited as long as the intended effect of the present invention can be obtained, but is preferably 50 to 1000 g / m 2 is preferable, and 250 to 800 g / m 2When the specific surface area of ​​inorganic substance B is within the above range, the contact area with other components of the lubricant increases, and the other components are dispersed around inorganic substance B, resulting in excellent seizure resistance. The specific surface area of ​​inorganic substance B can be measured by the BET single-point method (JIS Z 8830:2013).

[0028] <Water-soluble inorganic salt C> The lubricant composition for plastic working according to one embodiment of the present invention may contain a water-soluble inorganic salt C (hereinafter simply referred to as "inorganic salt C"). Inorganic salt C has the role of improving the seizure resistance and adhesion of the lubricating coating. As inorganic salt C, phosphate, condensed phosphate, silicate, borate, molybdate, and tungstate are preferred. The form of the salt is not particularly limited, but examples include alkali metal salt, alkaline earth metal salt, and ammonium salt. Phosphates include orthophosphates such as sodium phosphate and potassium phosphate; condensed phosphates include pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate, and tripolyphosphates such as sodium tripolyphosphate and potassium tripolyphosphate; silicates include sodium silicate and potassium silicate; borates include sodium borate (sodium tetraborate), potassium borate (potassium tetraborate, etc.), and ammonium borate (ammonium tetraborate, etc.); molybdates include ammonium molybdate and sodium molybdate; and tungstates include, but are not limited to, sodium tungstate. Water-soluble inorganic salts C exclude those that fall under inorganic substance B.

[0029] When inorganic salt C is used, the lower limit of its content is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on the solid content of the lubricant composition for plastic working. The upper limit of its content is preferably 20% by mass or less, more preferably 15% by mass or less. That is, the content of inorganic salt C is preferably, for example, 1 to 20% by mass, more preferably 3 to 15% by mass, and even more preferably 5 to 15% by mass, based on the solid content of the lubricant composition for plastic working. When the content of inorganic salt C relative to the solid content of the lubricant composition for plastic working is within the above range, the lubricant composition for plastic working can be easily applied uniformly. One type of inorganic salt C may be used alone, or two or more types may be used in combination. When two or more types of inorganic salt C are used, the above-mentioned "% by mass" refers to the total amount.

[0030] From the viewpoint of uniformly applying the lubricant composition for plastic working, the mass M of the polymer A in the lubricant composition for plastic working is A and the mass M of inorganic substance B B The mass ratio M of inorganic salt C to the total C / (M A +M B ) is preferably 0.01 or more, more preferably 0.02 or more, even more preferably 0.05 or more, and is preferably 0.3 or less, more preferably 0.2 or less, even more preferably 0.1 or less. That is, the mass ratio M C / (M A +M B ) is, for example, preferably 0.01 to 0.3, more preferably 0.02 to 0.2, and even more preferably 0.05 to 0.1. C / (M A +M B When M is within the above range, the lubricant composition has excellent uniformity in application. C / (M A +M B ) exceeds 0.3, the water resistance of the lubricant film tends to be poor.

[0031] <Water-soluble polymer compound D> The lubricant composition for plastic working according to one embodiment of the present invention may contain a water-soluble polymer compound D (hereinafter simply referred to as "polymer D") other than polymer A. Polymer D plays a role in improving the stability of the lubricant composition for plastic working, improving smoothness during film formation, and suppressing film unevenness. The term "water-soluble" in water-soluble polymer compound D means that when 1 g of a sample (or powder if solid) is placed in 1000 mL of pure water and repeatedly shaken vigorously for 30 seconds at 20°C ± 5°C every 5 minutes, the sample completely dissolves (the solid becomes invisible) within 30 minutes.

[0032] The polymer D is preferably one or more selected from the group consisting of urethane resins, polycarboxylic acid resins, polyvinyl alcohol resins, polyether resins, and polysaccharides. Examples of urethane resins include polymers of polyols and polyisocyanates; examples of polycarboxylic acid resins include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, salts thereof, and copolymers thereof; examples of polyvinyl alcohol resins include polyvinyl alcohol; examples of polyether resins include polyethylene glycol and polypropylene glycol; and examples of polysaccharides include, but are not limited to, methyl cellulose, carboxymethyl cellulose or salts thereof, methyl starch, and methyl guar gum.

[0033] When polymer D is used, its content is preferably 1 to 20 mass %, more preferably 2 to 15 mass %, and even more preferably 3 to 10 mass %, based on the solid content of the lubricant composition for plastic working. When the content of polymer D is within the above range based on the solid content of the lubricant composition for plastic working, the adhesion of the film formed from the lubricant composition for plastic working is excellent. Polymer D may be used alone, or two or more types may be used in combination. When two or more types of polymer D are used, the above mass % refers to the total amount.

[0034] The mass M of polymer A in the lubricant composition for plastic working A and the mass M of inorganic substance B B The mass M of polymer D relative to the sum of DRatio of M D / (M A +M B The lower limit of the ratio M is preferably 0.01 or more, more preferably 0.02 or more. D / (M A +M B The upper limit of the mass ratio M is preferably 0.25 or less, more preferably 0.20 or less, and even more preferably 0.12 or less. D / (M A +M B ) is, for example, preferably 0.01 to 0.25, more preferably 0.02 to 0.20, and even more preferably 0.02 to 0.12. D / (M A +M B ) is within the above range, the film formed from the lubricant composition for plastic working has excellent film formation stability.

[0035] <Wax E> The lubricant composition for plastic working according to one embodiment of the present invention may contain wax E. Examples of wax E include, but are not limited to, carnauba wax, paraffin wax, microcrystalline wax, polyethylene wax, and polypropylene wax. The use of wax E can reduce friction between an article with a lubricating coating formed from the lubricant composition for plastic working and a mating material. Wax E is preferably used in an amount of 1 to 20 mass% relative to the solid content of the lubricant composition for plastic working. Wax E may be used alone or in combination of two or more types. Wax E may also be dispersed or emulsified in water and blended. When two or more types of wax E are used, the mass% refers to the total amount.

[0036] <Solid Lubricant F> The lubricant composition for plastic working according to one embodiment of the present invention may contain a solid lubricant F. Examples of the solid lubricant F include, but are not limited to, molybdenum disulfide, graphite, and boron nitride. By using the solid lubricant F, the lubrication properties of the lubricating film formed from the lubricant composition for plastic working can be improved even in a hygroscopic environment. The solid lubricant F is preferably used in an amount of 1 to 20 mass % based on the solid content of the lubricant composition for plastic working. The solid lubricant F may be used alone or in combination of two or more. When two or more solid lubricants F are used, the mass % refers to the total amount thereof.

[0037] <Surfactant> The lubricant composition for plastic working according to one embodiment of the present invention may contain a surfactant. The surfactant may be any of nonionic surfactants, anionic surfactants, amphoteric surfactants, and cationic surfactants. Nonionic surfactants include, but are not limited to, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters composed of polyethylene glycol and higher fatty acids (e.g., having 12 to 18 carbon atoms), and polyoxyethylene sorbitan alkyl esters composed of sorbitan, polyethylene glycol (or ethylene oxide), and higher fatty acids (e.g., having 12 to 18 carbon atoms). Anionic surfactants include, but are not limited to, higher fatty acid salts, alkyl sulfate ester salts, alkylbenzene sulfonates, alkyl phosphate ester salts, and dithiophosphate ester salts. Amphoteric surfactants include, but are not limited to, amino acid-type and betaine-type carboxylate salts. Cationic surfactants include, but are not limited to, aliphatic amine salts, quaternary ammonium salts, and the like. These surfactants may be used alone or in combination. The surfactant is preferably used in an amount of 0.05 to 5 mass % relative to the solid content of the lubricant composition for plastic working. When two or more surfactants are used, the mass % refers to the total amount thereof.

[0038] <Other ingredients> The lubricant composition for plastic working according to one embodiment of the present invention can be appropriately blended with components such as rust prevention additives, preservatives, colorants, viscosity modifiers, and stabilizers, as long as the object of the present invention is not impaired.

[0039] <Solvent or Dispersion Medium> The lubricant composition for plastic working according to one embodiment of the present invention can be provided as a liquid in which the various lubricant raw materials described above are dissolved or dispersed in a solvent or dispersion medium. The solvent or dispersion medium can be water (e.g., deionized water), but it is also possible to use water-miscible organic solvents such as 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; and pyrrolidone solvents such as 1-methyl-2-pyrrolidone and 1-ethyl-2-pyrrolidone. From the viewpoint of easier handling of the lubricant composition, it is preferable to use water (e.g., deionized water).

[0040] <Method for producing lubricant composition for plastic working> The method for producing the lubricant composition for plastic working according to one embodiment of the present invention is not particularly limited, but it is produced by mixing the various lubricant raw materials described above with a solvent or dispersion medium. The method for mixing the lubricant raw material with the solvent or dispersion medium is not particularly limited, but it can be carried out by a general method such as propeller stirring or stirring with a homogenizer. Furthermore, heating may be performed as appropriate during mixing. A known surfactant can be used to obtain a stable liquid state.

[0041] <Method of manufacturing metal material with lubricating film> Next, a method for producing a metal material with a lubricating coating, which includes application of a lubricant composition for plastic working according to one embodiment of the present invention, will be described. One embodiment of the method for producing a metal material with a lubricating coating includes a step of contacting a metal material with a lubricant composition for plastic working according to one embodiment of the present invention (contact step), and a step of drying the metal material after the contact step (drying step). A step of cleaning the metal material (cleaning step) may be carried out before the step of contacting the metal material with the lubricant composition for plastic working. Each step will be described below.

[0042] [Cleaning process (pretreatment process)] To clean the surface of the metal material, a known cleaning step may be carried out before the contact step with the lubricant composition. The purpose of cleaning is to remove oxide scale grown by annealing or the like and various contaminants (oil, etc.). Examples of cleaning steps include shot blasting, sand blasting, wet blasting, peeling, alkaline degreasing, and acid cleaning. Two or more cleaning steps may be combined.

[0043] [Contact process] The contacting step between the metal material and the lubricant composition may be carried out by a known method, such as, but not limited to, a dipping method, a flow coating method, or a spraying method. The contacting step is sufficient as long as at least the surface portion of the workpiece that comes into contact with the mating material, such as a mold, is coated with the lubricant composition. The temperature in the contacting step is not particularly limited, but 40 to 80°C is preferred. To promote drying of the lubricant composition after contact, the metal material may be heated to 60 to 80°C before contacting with the lubricant composition. The contacting time is also not particularly limited, but is typically 5 to 300 seconds, e.g., 10 to 180 seconds.

[0044] [Drying process (post-processing process)] After the contact step, the lubricant composition on the surface of the metal material is in a wet state and is prone to peeling due to contact, etc. Therefore, it is preferable to provide a drying step as a post-treatment step to turn the lubricant composition into a dry film and prevent peeling. Drying may be carried out at room temperature, but it is preferable to dry at 60 to 150°C for 1 to 30 minutes.

[0045] The amount of the lubricating film formed on the metal surface is adjusted as appropriate depending on the metal material to be processed and the degree of processing, but the amount of the film to be applied is generally 0.5 to 40 g / m 2 is preferred, and 2 to 20 g / m 2 More preferably, the coating amount is 0.5 g / m 2 If the amount is less than 40 g / m, sufficient lubrication for processing tends to be insufficient. 2 If the content exceeds 100%, there is no problem with the lubrication during processing, but clogging of the mold with residue and the like is likely to occur. The amount of adhesion can be calculated from the difference in mass of the metal material before and after processing and the projected area of ​​the surface to which the lubricant composition is attached. In order to control the amount of adhesion to fall within the above-mentioned range, for example, the solid content of the lubricant composition can be adjusted. Specifically, a high-concentration lubricant composition can be diluted to a desired ratio with a solvent or dispersion medium such as water, and the diluted composition can be used as the lubricant composition for plastic processing.

[0046] The step of forming a lubricating film on the surface of a metal material using a lubricant composition for plastic working according to one embodiment of the present invention is a means of making the lubricant composition present on the working surface of the metal material, and it is sufficient that the lubricant composition for plastic working is present on the working surface. Thus, according to one embodiment of the method for producing a metal material with a lubricating film, the lubricant composition for plastic working according to one embodiment of the present invention is dried in advance, and then powdered during drawing, such as wire drawing or pipe drawing, and the powder is drawn into a die as a dry lubricant composition to form a lubricating film on the working surface of the metal material. In this case, the step of forming a film in advance can be omitted, which is convenient from a production standpoint. [Example]

[0047] The effects of the present invention will be specifically explained below by showing examples of the present invention and comparative examples, but the present invention is not limited to these examples.

[0048] (1) Metal materials The metal material used in Examples 1 to 28 and Comparative Examples 1 to 6 was carbon steel for machine structural use (S10C material) as specified in JIS G4051: 2016. The shape was a barrel shape with an upset ratio of 45%, which is used in the ball-ironing friction test method disclosed in the reference (Takahashi Akinori, Hirose Hitoshi, Omiyama Shinobu, Wang Zhigang: Proceedings of the 62nd Japan Society for Technology of Plasticity, (2011), pp. 89-90).

[0049] (2) Polymer A [Polymer A1] A commercially available product was used as polymer A1. Polymer A1 has a polyamide chain and a polyalkylene oxide chain in one molecule. When the IR spectrum of this polymer A1 was measured by the ATR method under the measurement conditions described above, the intensity ratio β of peak β to peak α was A / α A The viscosity was 1.07, and the softening point was 162°C.

[0050] [Polymer A2] Polymer A2 was synthesized with reference to Japanese Patent Publication No. 45-7559. Specifically, a diamine compound HNCH(CHCHO) having a polyethylene oxide chain was obtained by hydrogenating a cyanoethylated polyethylene glycol. n CH2CH2NH2 (average value of n = 21.2) and polyamide HO(-CO-(CH2)) with carboxy groups at both ends obtained by reacting lauryllactam with adipic acid, with reference to JP-T-2016-532728. 12 -NH-) n CO(CH2)4COOH (average value of n = 48.0) was mixed so that the molar ratio of amino groups to carboxy groups was 1:1, and the mixture was placed in a reaction vessel. Next, the pressure inside the reaction vessel was reduced to 3 mmHg, and the mixture was heated to 230°C. After the polymer was dissolved, stirring was started, and the reaction was continued for 10 hours, synthesizing polymer A2. When the IR spectrum of the synthesized A2 was measured by the ATR method under the measurement conditions described above, the peak intensity ratio β A / α A The viscosity was 0.65, and the softening point was 129°C.

[0051] [Polymer A3] Polymer A3 was synthesized in the same manner as polymer A2, except that a diamine having a polyethylene oxide chain with an average value of n=7.0 was used. The IR spectrum of the synthesized polymer A3 was measured by the ATR method under the above-mentioned measurement conditions, and the peak intensity ratio β A / α A The viscosity was 2.0, and the softening point was 169°C.

[0052] [Polymer A4~A7] Commercially available nylons were prepared as polymers A4 to A7. A / α A The softening point and melting point were measured, and the results are described below.

[0053] (3) Preparation of lubricant composition The lubricant compositions shown in Examples 1 to 28 and Comparative Examples 1 to 6 were prepared by blending the raw materials shown below to obtain the content ratios shown in Table 1. Specifically, water was charged into a mixing vessel, and the raw materials were mixed in order based on the content ratios shown in Table 1 while stirring at 60°C. D2 was used after being adjusted in advance with sodium hydroxide to a neutralization degree of 1. The numerical values ​​for the content ratios of each raw material in Table 1 represent the mass % of each raw material relative to the total mass (solid content) of the blended raw materials excluding water. The lubricant composition had a coating weight of 5.0 g / m 2 The water concentration was adjusted so that

[0054] <Polymer A> A1: Polymer A1 (commercially available product) (water-insoluble, β A / α A =1.07, softening point=162℃) A2: Synthetic polymer A2 (water-insoluble, β A / α A =0.65, softening point=129℃) A3: Synthetic polymer A3 (water soluble, β A / α A =2.0, softening point=169℃) A4: AQ nylon P-95 (manufactured by Toray Industries, Inc.) (water-soluble, β A / α A=1.19, softening point=134℃) A5: AQ nylon A-90 (manufactured by Toray Industries, Inc.) (water-soluble, β A / α A =0.32, softening point=125℃) A6: AQ nylon T-70 (manufactured by Toray Industries, Inc.) (water-soluble, β A / α A =0.41, softening point=131℃) A7: AQ nylon P-70 (manufactured by Toray Industries, Inc.) (water-soluble, β A / α A =0.71, softening point=138℃) When the solubility in water was evaluated in accordance with the above-mentioned criteria, A1 and A2 were found to be water-insoluble, while A3 to A7 were found to be water-soluble. <Inorganic substance B> B1: Colloidal silica (average particle size: 12 nm) B2: Mullite (3Al2O3 2SiO2) (average particle size: 1.9μm) B3: Silica gel (average particle size: 10 μm) (specific surface area by BET single point method = 520 g / m 2 ) B4: Magnesia (average particle size: 3.5μm) B5: Alumina (average particle size: 2 μm) B6: Forsterite (2MgO·SiO2) (average particle size: 2.5 μm) B7: Talc (3MgO·4SiO2·H2O) (average particle size: 4.6 μm) B8: Kaolin (Al2O3·2SiO2·2H2O) (average particle size: 1.2 μm) B9: Hectorite (Na0.3(Mg,Li)3Si4O10(OH)2) (average particle size: 0.1μm) B10: Laponite RD (BYK synthetic hectorite) (average particle size: 0.1 μm) (BET specific surface area (catalog value) = 900 g / m 2 ) When the solubility in water was evaluated in accordance with the above-mentioned criteria, all of B1 to B10 were found to be water-insoluble. <Water-soluble inorganic salt C> C1: Potassium tetraborate dihydrate C2: Sodium tungstate <Water-soluble polymer compound D> D1: Cellogen 7A (sodium carboxymethylcellulose, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) D2: ISOBAM 304 (imide derivative of isobutylene-maleic anhydride copolymer manufactured by Kuraray Co., Ltd.) <Wax E> E1: Polyethylene wax <Solid Lubricant F> F1: Molybdenum disulfide <Mixture of polyamide and polyalkylene oxide> G1: Sepolsion PA150 (Sumitomo Seika Chemicals Co., Ltd.) (water-insoluble, β A / α A =0.21) G2: Sepolsion PA150 and PEG6000S (manufactured by Sanyo Chemical Industries, Ltd.) were mixed, and β A / α A =1.10 <Other resins> Epoxy resin: Modepics 303 (manufactured by Arakawa Chemical Industries, Ltd.) Urethane resin: Superflex 150 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Acrylic resin: Saivinol EC505 (manufactured by Saiden Chemical Co., Ltd.)

[0055] (4) Manufacturing of metal materials with lubricating coating (4-1) Purification of metal materials The surfaces of the metal materials used in the examples and comparative examples were cleaned by the following method. A commercially available degreaser (Fine Cleaner E6400, manufactured by Nihon Parkerizing Co., Ltd.) was adjusted to a concentration of 20 g / L using tap water and heated to a constant temperature of 60°C. The metal materials were immersed in the degreaser for 10 minutes to degrease them. Subsequently, the metal materials were immersed in tap water at 25°C for 20 seconds to rinse off any remaining degreaser and dirt.

[0056] (4-2) Film formation A coating was formed on the metal material that had been subjected to the cleaning treatment by the following method. The cleaned metal material was immersed for 15 seconds in each lubricant composition listed in Table 1 that had been heated to 60°C, and then the metal material was removed. Thereafter, the metal material was left to dry in an ambient temperature atmosphere, thereby producing a metal material with a lubricating coating (Examples 1 to 28, Comparative Examples 1 to 6).

[0057] (5) Evaluation test (5-1) Ball squeezing test The evaluation of seizure resistance and lubricity in processing based on the maximum processing load was carried out based on the ball-ironing friction test method disclosed in the above-mentioned reference. For the evaluation test, after the coating was formed, the protruding side of the barrel-shaped test piece was subjected to ironing (heavy ironing) using three ball-shaped dies (SUJ-2 bearing balls with a diameter of 10 mm).To evaluate the processing lubricity of the coating under dry conditions and under hygroscopic conditions, the test piece under dry conditions was left to stand in a constant temperature and humidity chamber set at 60°C and a relative humidity of 5% or less, and the test piece under hygroscopic conditions was left to stand for 24 hours in an environment set at 30°C and a relative humidity of 80%, and then the ball ironing test was performed immediately after removing it from the constant temperature and humidity chamber.

[0058] [Ironed surface evaluation] The seizure resistance of each test piece was evaluated by visually inspecting the appearance of the ironed surface, where an increase in surface area was observed, according to the evaluation criteria shown in Figure 1. The test results are shown in Table 1. S: No seizure or very thin scratches A: There is some short burning B: Many short burns C: Burning occurs over a wide area D: There is a full burn from the middle of the stroke.

[0059] [Maximum ironing load evaluation] The maximum load value obtained during ironing was evaluated according to the following index. A smaller maximum load value indicates better processing lubrication. The test results are shown in Table 1. S: Maximum load value is less than 35kN A: The maximum load value is 35kN or more but less than 38kN. B: Maximum load value is 38kN or more but less than 40kN C: Maximum load value is 40kN or more but less than 42kN D: Maximum load value is 42kN or more

[0060] [Evaluation of uniform coating properties] Instead of the barrel-shaped metal material described above, an SPC plate material (cold-rolled steel plate) measuring 70 mm × 150 mm × 0.8 mm was prepared. The lubricant compositions according to the examples and comparative examples prepared above were coated with a coating amount of 10 g / m 2 The moisture concentration was changed and an appropriate bar coater size was selected so that the lubricant composition was applied dropwise to the plate using a bar coater, and then the plate was dried in an oven at 60°C to produce a test specimen with a lubricating film formed on the surface. The thickness of the lubricating film was measured using an ultrasonic film thickness gauge at 7 points in the longitudinal direction and 3 points in the lateral direction at intervals of ±20 mm from the center of the plate (21 points in total). The coefficient of variation of the measured values ​​was calculated and evaluated according to the following index. The results are shown in Table 1. A: The coefficient of variation is less than 0.05 B: Coefficient of variation is 0.05 or more and less than 0.10 C: Coefficient of variation is 0.10 or more and less than 0.15 D: Coefficient of variation is 0.15 or more

[0061] [Liquid stability] 200 ml of each lubricant composition prepared above according to each Example and Comparative Example was thoroughly stirred using a stirrer to avoid foaming, then placed in a 250 ml plastic graduated cylinder and allowed to stand. After 24 hours, the capped graduated cylinder was inverted upside down 10 times at a rate of once per second, then allowed to stand again, and the state of the lubricant composition was observed after 1 minute. A 10 mm diameter steel ball was then placed in the graduated cylinder for stirring, and the capped graduated cylinder was inverted upside down 10 times at a rate of once per second, then allowed to stand, and the state of the lubricant composition was observed after 1 minute. The results of each observation were evaluated using the following indices. The results are shown in Table 1. A: When observing after inverting only the chemical solution, the precipitate in the treatment solution is less than 5% of the liquid surface height. B: When observed after inversion of only the chemical solution, the sediment in the treatment liquid exceeds 5% of the liquid surface height, and when observed after inversion with the steel ball, the sediment in the treatment liquid is 5% or less of the liquid surface height. C: When observing after inverting only the chemical solution, the precipitate in the treatment liquid exceeds 5% of the liquid surface height, and when observing after inverting with the steel ball, the precipitate in the treatment liquid exceeds 5% and is 10% or less of the liquid surface height. D: When observing after inversion of only the chemical solution, the precipitate in the treatment liquid exceeds 5% of the liquid surface height, and when observing after inversion with the steel ball, the precipitate in the treatment liquid exceeds 10% of the liquid surface height.

[0062] [Table 1-1]

[0063] [Table 1-2]

[0064] [Table 1-3]

[0065] [Table 1-4]

[0066] As is clear from Table 1, Examples 1 to 28 of the lubricant composition for plastic working according to the embodiment of the present invention exhibit excellent lubricity under dry conditions. Also, Examples 1 to 21 and 28, in which the polymer A and inorganic substance B were water-insoluble, exhibit excellent lubricity even under hygroscopic conditions. The present invention makes it possible to obtain a lubricating coating with excellent plastic processing properties, thereby reducing the energy required for plastic processing and contributing to the SDGs.

Claims

1. a polymer A having a polyamide chain and a polyalkylene oxide chain in one molecule; Smectite clay minerals, and aM x O y bSiO 2 ・cH 2 and one or more inorganic substances B selected from inorganic oxides represented by the formula (I) and (II) (wherein a, b, and c are rational numbers satisfying 0≦a≦3, 0≦b≦4, 0≦c≦5, and 1≦a+b; x and y are either x=2 and y=1, or x=y=1, or x=2 and y=3; and M is Mg or Al).

2. 2. The lubricant composition for plastic working according to claim 1, wherein the polymer A is water-insoluble.

3. 3. The lubricant composition for plastic working according to claim 1, wherein the inorganic substance B is water-insoluble.

4. The polymer A has a peak intensity of 1580 to 1660 cm in infrared spectroscopy (IR). -1 Peak α and 1060-1150 cm -1 and the peak β has a peak intensity α A The peak intensity β of the peak β relative to A The ratio β A / α A The lubricant composition for plastic working according to claim 1 or 2, wherein is 0.3 to 2.

0.

5. The mass M of the polymer A A The mass M of the inorganic substance B B The ratio M B / M A The lubricant composition for plastic working according to claim 1 or 2, wherein is 0.01 to 1.

5.

6. 3. The lubricant composition for plastic working according to claim 1, further comprising a water-soluble inorganic salt C (excluding the inorganic substance B).

7. 7. The lubricant composition for plastic working according to claim 6, wherein the water-soluble inorganic salt C comprises one or more salts selected from the group consisting of phosphates, condensed phosphates, silicates, borates, molybdates, and tungstates.

8. The mass M of the polymer A A and the mass M of the inorganic substance B B The mass M of the water-soluble inorganic salt C relative to the total C The ratio M C / (M A +M B 7. The lubricant composition for plastic working according to claim 6, wherein the value of (I) is 0.01 to 0.

3.

9. The lubricant composition for plastic working according to claim 1 or 2, further comprising a water-soluble polymer compound D (excluding polymer A).

10. 10. The lubricant composition for plastic working according to claim 9, wherein the water-soluble polymer compound D contains one or more selected from the group consisting of urethane-based resins, polycarboxylic acid-based resins, polyvinyl alcohol-based resins, polyether-based resins, and polysaccharides.

11. The mass M of the polymer A A and the mass M of the inorganic substance B B The mass M of the water-soluble polymer compound D relative to the total D The ratio M D / (M A +M B 10. The lubricant composition for plastic working according to claim 9, wherein the value of (I) is 0.01 to 0.

25.

12. 3. The lubricant composition for plastic working according to claim 1, wherein the softening point of the polymer A is 100 to 200°C.

13. A method for producing a metal material with a lubricating coating, comprising the step of bringing the lubricant composition for plastic working according to claim 1 or 2 into contact with a metal material.

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