Surface treatment agent for carbon steel material, carbon steel material having surface treatment film, and method for producing same

Abstract

Provided is a surface treatment agent capable of forming a surface treatment film having excellent electrolytic corrosion resistance. The problem is solved by a surface treatment agent for a carbon steel material comprising a silicone resin (A), a titanium compound (B), a barium compound (C), an aromatic hydrocarbon-based solvent (D), and an alkoxysilane (E) having an amino group, (I) the ratio (BM / AM) of the mass (BM) of the compound (B) to the mass (AM) of the silicone resin (A) is in the range of 0.05-3.12, and the ratio (BM / AM) of the mass (BM) of the compound (B) to the mass (AM) of the silicone resin (A) is in the range of 0.05-3.12. (II) The ratio (CM / AM) of the mass (CM) of the compound (C) to the mass (AM) of the silicone resin (A) is in the range of 0.02-0.55, and (III) the ratio (EM / AM) of the mass (EM) of the compound (E) to the mass (AM) of the silicone resin (A) is in the range of 0.01-0.43.

Description

Technical Field

[0001] The present invention relates to a surface treatment agent for carbon steel materials that can be preferably used for mechanical component parts used in products such as automobiles, home appliances, OA equipment, and medical equipment, a method for manufacturing a carbon steel material with a surface treatment coating using the surface treatment agent, and a carbon steel material with a surface treatment coating obtained by the manufacturing method. Background Art

[0002] In industrial products such as automobiles, home appliances, OA equipment, and medical equipment, metal materials can be used to constitute mechanical components of the above products. Since these industrial products are used in various environments, the metal materials used in these industrial products require various properties. Therefore, in recent years, in order to give metal materials various properties, a technology of providing a surface treatment coating with various properties on the surface of a metal material or on the surface thereof has been developed. For example, the following technology is disclosed in Patent Document 1: a composition for surface treatment of a metal material prepared by dissolving or dispersing a prescribed phosphoric acid compound, a fluoric acid having a prescribed element such as titanium or zirconium, a silane coupling agent having at least one amino group containing active hydrogen, and a silane coupling agent having at least one epoxy group in a prescribed amount is applied to the metal surface, and dried to form a prescribed coating.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-213958. Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In recent years, it is necessary to develop a technology capable of forming a surface treatment film having excellent electrolytic corrosion resistance in carbon steel materials used in mechanical element components. Therefore, an object of the present invention is to provide a surface treatment agent capable of forming a surface treatment film having excellent electrolytic corrosion resistance, a method for manufacturing a carbon steel material having a surface treatment film using the surface treatment agent, and a carbon steel material having a surface treatment film obtained by the manufacturing method.

[0008] Solutions for solving problems

[0009] The present inventors have repeatedly conducted intensive studies to solve the above-mentioned problems, and as a result, have found that by using a surface treatment agent containing a silicone resin, a compound containing a specified metal element, and an aromatic hydrocarbon solvent in specified amounts, a surface treatment film with excellent electrolytic corrosion resistance can be formed on the surface of a carbon steel material or on the surface, thereby completing the present invention.

[0010] That is, the present invention is:

[0011] [1] A surface treatment agent for a carbon steel material, comprising a silicone resin (A), a titanium compound (B), a barium compound (C), an aromatic hydrocarbon solvent (D), and an alkoxysilane having an amino group (E),

[0012] (I) The mass (B) of the above compound (B) M ) and the mass (A) of the above silicone resin (A) M ) M / A M ) is within the range of 0.05 to 3.12,

[0013] (II) The mass (C) of the above compound (C) M ) and the mass (A) of the above silicone resin (A) M ) M / A M ) is within the range of 0.02 to 0.55,

[0014] (III) The mass (E) of the above compound (E) M ) and the mass (A) of the above silicone resin (A) M ) M / A M ) is within the range of 0.01 to 0.43;

[0015] [2] A method for producing a carbon steel material, the carbon steel material having a surface treatment coating,

[0016] The manufacturing method of the above-mentioned carbon steel material comprises:

[0017] In the first step, the surface treatment agent described in [1] is brought into contact with the surface or the surface of the carbon steel material; and

[0018] The second step is to dry the surface treatment agent that has been in contact with the carbon steel material to form a surface treatment film;

[0019] [3] The manufacturing method according to [2], further comprising, before the first step, a base film forming step of bringing a base treatment agent containing a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, or phosphoric acid into contact with the surface of the carbon steel material or on the surface thereof to form a base film;

[0020] [4] A carbon steel material having a surface treatment coating, which is obtained by the manufacturing method described in [2] or [3] above, wherein the film thickness of the surface treatment coating is within a range of 3 μm to 100 μm.

[0021] [5] A carbon steel material having a surface treatment coating, wherein the surface of the carbon steel material or the surface of the carbon steel material has a surface treatment coating,

[0022] The surface treatment film contains a silicone resin (A), a titanium compound (B), a barium compound (C), and a polymer derived from an alkoxysilane having an amino group (E).

[0023] (I) The mass (B) of the above compound (B) M ) and the mass (A) of the above silicone resin (A) M ) M / A M ) is within the range of 0.05 to 3.12,

[0024] (II) The mass (C) of the above compound (C) M ) and the mass (A) of the above silicone resin (A) M ) M / A M ) is within the range of 0.02 to 0.55;

[0025] [6] The carbon steel material with a surface treatment coating according to [5] above, wherein a base film is provided between the carbon steel material and the surface treatment coating.

[0026] The base film comprises at least one selected from a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, and phosphoric acid;

[0027] [7] The carbon steel material having a surface treatment coating according to [5] or [6] above, wherein the film thickness of the surface treatment coating is within a range of 3 μm to 100 μm.

[0028] [8] The high carbon steel material having a surface treatment coating according to any one of [5] to [7] above, wherein the carbon steel material is a high carbon steel containing 0.95 mass % or more of carbon; etc.

[0029] Effects of the Invention

[0030] According to the present invention, there are provided a surface treatment agent capable of forming a surface treatment film having excellent electrolytic corrosion resistance, a method for producing a carbon steel material having a surface treatment film using the surface treatment agent, and a carbon steel material having a surface treatment film obtained by the production method. DETAILED DESCRIPTION

[0031] Hereinafter, the surface treatment agent, the carbon steel material having a surface treatment film and the method for producing the same according to the present invention will be described.

[0032] (Surface treatment agent)

[0033] The surface treatment agent of the present embodiment contains a silicone resin (A), a titanium compound (B), a barium compound (C), an aromatic hydrocarbon solvent (D) and an alkoxysilane having an amino group (E). By using this surface treatment agent, a surface treatment coating having excellent electrolytic corrosion resistance (especially electrolytic corrosion resistance in a high temperature environment) can be formed on a carbon steel material. In addition, high temperature refers to at least 100°C or above, preferably 150°C or above, and more preferably 200°C or above. As such, since the surface treatment agent of the present embodiment can form a surface treatment coating having excellent electrolytic corrosion resistance, the surface treatment agent of the present embodiment is useful as an electrolytic corrosion resistance coating forming agent. In addition, a surface treatment coating having excellent electrolytic corrosion resistance is useful for carbon steel materials used to form mechanical component parts of industrial products such as automobiles, home appliances, OA equipment, and medical equipment.

[0034] <Silicone resin (A)>

[0035] As the organosilicon resin (A), there is no particular limitation as long as it has an organopolysiloxane structure containing multiple siloxane bonds and an organic group bonded to silicon (Si). It is preferred to have an organopolysiloxane structure having at least two or more organic groups bonded to Si in one molecule. In addition, there is no particular limitation on the position of the organic group bond, and it can be bonded to the main chain, side chain or end. In addition, the organosilicon resin (A) may be a homopolymer having the above-mentioned organopolysiloxane structure, or a mixture of a homopolymer having the above-mentioned organopolysiloxane structure and a homopolymer having a polysiloxane structure, or a copolymer (block copolymer or graft polymer) having the above-mentioned organopolysiloxane structure and a polysiloxane structure. In addition, the organosilicon resin (A) may be an addition type or a condensation type. Furthermore, the organosilicon resin (A) may be any one of a thermosetting type, a room temperature curing type (RVT), and a UV curing type.

[0036] As the organic group bonded to Si in the organopolysiloxane structure, for example, saturated hydrocarbon groups, unsaturated hydrocarbon groups, halogenated alkyl groups, epoxycyclohexyl groups, etc. can be cited, but are not limited to these. As the saturated hydrocarbon group, for example, straight-chain or branched alkyl groups, cycloalkyl groups, etc. can be cited, but are not limited to these. In addition, as the unsaturated hydrocarbon group, for example, straight-chain or branched alkenyl groups, cycloalkenyl groups, cycloalkenyl alkyl groups, aryl groups, etc. can be cited, but are not limited to these. In addition, as the organic group bonded to Si, it is preferably an unsaturated hydrocarbon group, more preferably an alkenyl group, and particularly preferably a vinyl or hexenyl group.

[0037] Examples of haloalkyl include chloromethyl, 3-chloropropyl, 1-chloro-2-methylpropyl, 3,3,3-trifluoropropyl, etc. Examples of alkyl include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. Examples of cycloalkyl include cyclopentyl, cyclohexyl, etc. Examples of linear or branched alkenyl include vinyl, 1-propenyl, allyl, isopropenyl, 1-butenyl, 2-butenyl, pentenyl, hexenyl, etc. Examples of cycloalkenyl include cyclopentenyl, cyclohexenyl, etc. Examples of cycloalkenyl include cyclopentenyl ethyl, cyclohexenyl ethyl, cyclohexenyl propyl, etc. Examples of aryl include phenyl, etc.

[0038] The polysiloxane structure is not particularly limited as long as it is different from the above-mentioned organopolysiloxane structure, and examples thereof include a polysiloxane structure having at least two hydrogen atoms bonded to Si in one molecule, a polysiloxane structure having at least two alkoxy groups bonded to Si in one molecule, etc. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. In addition, the alkoxy group may be linear or branched.

[0039] In the preparation of the surface treatment agent, the various silicone resins mentioned above can be used alone or in combination of two or more. As a preferred embodiment of the silicone resin (A), a mixture of a homopolymer having an organopolysiloxane structure having at least two unsaturated hydrocarbon groups bonded to Si in one molecule and a homopolymer having a polysiloxane structure having at least two hydrogen atoms bonded to Si in one molecule can be cited.

[0040] Examples of the homopolymer having an organopolysiloxane structure having at least two unsaturated hydrocarbon groups bonded to Si in one molecule include dimethylpolysiloxane having dimethylvinylsiloxy groups at both ends of the molecular chain, dimethylsiloxane-methylphenylsiloxane copolymer having dimethylvinylsiloxy groups at both ends of the molecular chain, dimethylsiloxane-methylvinylsiloxane copolymer having dimethylvinylsiloxane groups at both ends of the molecular chain, dimethylsiloxane-methylvinylsiloxane copolymer having trimethylsiloxy groups at both ends of the molecular chain, dimethylsiloxane-methylvinylsiloxane terpolymer having trimethylsiloxy groups at both ends of the molecular chain, dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane terpolymer having trimethylsiloxy groups at both ends of the molecular chain, dimethylsiloxane-methylvinylsiloxane copolymer having silanol groups at both ends of the molecular chain, and methylvinylpolysiloxane having silanol groups at both ends of the molecular chain. In addition, various polymers, copolymers and terpolymers in which a part of the methyl groups are replaced by alkyl groups other than methyl groups such as ethyl and propyl groups, or halogenated alkyl groups such as 3,3,3-trifluoropropyl and 3,3,3-trichloropropyl groups can also be mentioned. A mixture of two or more selected from these polymers, copolymers and terpolymers can also be used for the preparation of the surface treatment agent.

[0041] The homopolymer having a polysiloxane structure having at least two or more hydrogen atoms bonded to Si in one molecule is not particularly limited, and examples thereof include organohydrogen polysiloxanes having a SiH group formed by at least two or more hydrogen atoms bonded to Si in one molecule, and having a diorganosiloxane structure as a main chain repeatedly, with both ends of the molecular chain being blocked by triorganosiloxy groups and having a linear, cyclic, branched, or three-dimensional network structure. More specifically, there can be mentioned methylhydrogen polysiloxane having trimethylsiloxy groups at both ends of the molecular chain, dimethylsiloxane-methylhydrogen siloxane copolymer having trimethylsiloxy groups at both ends of the molecular chain, methylhydrogen polysiloxane having silanol groups at both ends of the molecular chain, dimethylsiloxane-methylhydrogen siloxane copolymer having silanol groups at both ends of the molecular chain, dimethyl polysiloxane having dimethylhydrogen siloxy groups at both ends of the molecular chain, methylhydrogen polysiloxane having dimethylhydrogen siloxy groups at both ends of the molecular chain, dimethylsiloxane-methylhydrogen siloxane copolymer having dimethylhydrogen siloxy groups at both ends of the molecular chain, etc. A mixture of two or more selected from these polymers and copolymers can also be used for the preparation of the surface treatment agent.

[0042] The weight average molecular weight of the silicone resin (A) is not particularly limited, but is usually in the range of 6000 to 45000, preferably 6500 to 40000. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) in terms of polystyrene.

[0043] <Compound (B)>

[0044] As compound (B), there is no particular limitation as long as it contains titanium as an element. As compounds containing titanium, for example, titanium oxysulfate, titanium oxynitrate, titanium nitrate, titanium oxychloride, titanium chloride, titanium dioxide sol, titanium oxide, potassium oxalate titanate, titanium lactate, titanium tetraisopropoxide, titanium tetraacetylacetonate, diisopropyl diacetylacetonate titanium, di(acetylacetonato) titanate diisopropyl, etc. can be cited. Titanium oxide is particularly preferably used.

[0045] In the preparation of the surface treatment agent, these compounds may be used alone or in combination of two or more.

[0046] <Compound (C)>

[0047] The compound (C) is not particularly limited as long as it contains barium as an element. Examples of compounds containing barium include barium hydroxide, barium oxide, barium fluoride, barium iodide, barium sulfate, barium hydrogen sulfate, barium sulfite, barium nitrate, barium phosphate, barium hydrogen carbonate, barium acetate, and barium chromate. In particular, barium sulfate is preferably used.

[0048] In the preparation of the surface treatment agent, these compounds may be used alone or in combination of two or more.

[0049] The content of the silicone resin (A) (when using a plurality of silicone resins, the total content) is in the range of 20 mass % to 90 mass %, preferably in the range of 54 mass % to 80 mass %, relative to the total mass of the silicone resin (A), the compound (B), the compound (C) and the compound (E).

[0050] In the surface treatment agent, the mass of compound (B) (B M ) [when using a plurality of compounds, the total mass] and the mass of the silicone resin (A) (A M ) [When using multiple silicone resins, it refers to the total mass] ratio (B M / A M ) is preferably in the range of 0.05 to 3.12, more preferably in the range of 0.10 to 0.61.

[0051] The mass of compound (C) M ) [when using a plurality of compounds, the total mass] and the mass of the silicone resin (A) (A M ) M / A M ) is preferably in the range of 0.02 to 0.55, more preferably in the range of 0.04 to 0.22.

[0052] <Aromatic hydrocarbon solvent (D)>

[0053] Examples of the aromatic hydrocarbon solvent (D) include hydrocarbons composed of a single ring or multiple planar rings each consisting of six carbon atoms with single bonds and double bonds alternating and electrons delocalized, and the types thereof are not particularly limited.

[0054] The aromatic hydrocarbon solvent (D) is not particularly limited as long as it has the above unit, and preferably has a solubility parameter (SP) value in the range of 8.5 or more and 9.5 or less, more preferably in the range of 8.8 or more and 9.3 or less. More specifically, benzene, toluene, o-xylene, p-xylene, m-xylene, ethylbenzene, cumene, etc. can be cited. In addition, in the preparation of the surface treatment agent, one of these organic solvents can be used, or two or more can be used in combination.

[0055] The content of the aromatic hydrocarbon solvent (D) in the surface treatment agent is not particularly limited, and in terms of mass ratio, it is preferably in the range of 40% by mass or more and 99% by mass or less, more preferably in the range of 45% by mass or more and 95% by mass or less.

[0056] <Alkoxysilane (E)>

[0057] Examples of the alkoxysilane having an amino group [hereinafter simply referred to as "alkoxysilane (E)"] are not particularly limited as long as it has an amino group, and examples include N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, polymers of the silane coupling agent, copolymers with the polymers, etc.

[0058] In the preparation of the surface treatment agent, when using the alkoxysilane (E), the mass (E M ) [in the case of using multiple alkoxysilanes, it refers to the total mass] and the mass (A M ) [in the case of using multiple organosilicon resins, it refers to the total mass] of the organosilicon resin (A) The ratio (E M / A M ) is preferably in the range of 0.01 or more and 0.43 or less, more preferably in the range of 0.17 or more and 0.39 or less, but is not limited to these ranges.

[0059] <Other additives>

[0060] In the surface treatment agent of the present embodiment, various additives may also be included as needed. As additives, for example, surfactants, defoamers, leveling agents, thickeners, antibacterial and antifungal agents, colorants, fluororesins, etc. can be cited, but are not limited to these. By adding these additives to the surface treatment agent, the storage and dryness of the surface treatment agent can be improved, or the operability in the manufacture of the surface treatment film using the surface treatment agent can be improved, or the appearance (especially the design) of the manufactured surface treatment film can be improved. These additives can be added within the scope of not damaging the effect of the present invention, and the content of the additives is at most a few percent by mass relative to the mass of the surface treatment agent.

[0061] (Method for producing surface treatment agent)

[0062] The surface treatment agent of the present embodiment can be produced by mixing a silicone resin (A), a titanium compound (B), a barium compound (C), an aromatic hydrocarbon solvent (D), an alkoxysilane (E), and the like.

[0063] (Carbon steel material with surface treatment coating and manufacturing method thereof)

[0064] The method for manufacturing a carbon steel material having a surface treatment film of the present embodiment includes: a first step of bringing the surface treatment agent into contact with the surface or on the surface of the carbon steel material; and a second step of drying the surface treatment agent that has been in contact with the carbon steel material to form a surface treatment film. By performing these steps, a carbon steel material having a surface treatment film can be manufactured.

[0065] Before the first step, the metal material may be pre-treated to remove oil and dirt attached to the surface of the carbon steel material. The pre-treatment method is not particularly limited, and examples thereof include hot water cleaning, solvent cleaning, and alkaline degreasing cleaning.

[0066] As the contact method of the first step, various contact methods can be used, and it is preferred to appropriately select the most suitable method according to the shape of the metal material to be treated. Specifically, coating methods such as immersion treatment method, spray treatment method, flow coating treatment method, roll coating method, rod coating method, and electrolytic deposition method can be cited; a coating method using one or more coating devices such as a spin coater, a slit coater, a die coater, a knife coater, and a dispenser, etc., and a coating method using a dispenser that can stably apply a predetermined amount of a surface treatment agent is preferred.

[0067] The temperature (ambient temperature) during the drying of the second step is not particularly limited, but is preferably in the range of 40 to 250°C, and more preferably in the range of 60 to 180°C. The drying method is not particularly limited, and examples thereof include a method of drying the surface treatment agent by heating the surface treatment agent in contact with the carbon steel material by hot air, an induction heater, infrared rays, near infrared rays, etc. In addition, the heating time is not particularly limited, and the most suitable conditions can be appropriately set according to the type of material used, the surface of the carbon steel material or the amount of the surface treatment agent attached to the surface, etc.

[0068] The method for manufacturing a carbon steel material having a surface treatment film of the present embodiment may also include, before the first step (after the pretreatment in the case of pretreatment), a third step of bringing a base treatment agent containing one or more selected from a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, etc., and phosphoric acid into contact with the surface or on the surface of the metal material; and a fourth step of washing or not washing the base treatment agent that has been in contact with the carbon steel material and drying it to form a base film. By performing the first and second steps after performing the third and fourth steps in this way, a metal material having a surface treatment film and a base film can be manufactured.

[0069] The substrate treatment agent comprises one or more selected from a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, and phosphoric acid. The silane coupling agent having an amino group is not particularly limited as long as it has one amino group, and examples thereof include N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0070] Furthermore, there are no particular limitations as long as it contains phosphoric acid, and examples thereof include manganese phosphate, iron phosphate, zinc phosphate, and calcium zinc phosphate. Among these, manganese phosphate is preferably used.

[0071] The solvent contained in the substrate treatment agent is not particularly limited, and the solvent can be cited as organic solvents such as alcohol, acetone, acetonitrile, benzene, cyclohexane, methyl acetate, ethyl acetate, methyl ethyl ketone, etc.; mixtures of these organic solvents and water, etc. As the organic solvent, alcohols with a carbon number of 5 or less are preferred. In addition, the mass ratio of water contained in the mixture is preferably less than 5% by mass. In addition, the substrate treatment agent may also include: a leveling agent for improving wettability to metal materials; a film-forming aid for improving film-forming properties; an organic crosslinking agent and an inorganic crosslinking agent for making the substrate film a more solid film; a defoaming agent for suppressing foaming; a thickener for controlling viscosity; additives such as rust inhibitors, which can be formulated within the range that does not impair the effect of the present invention.

[0072] As the contact method of the third step, various contact methods can be used, and it is preferred to appropriately select the most suitable method according to the shape of the metal material to be treated. Specifically, in addition to the method of coating using the above-mentioned coating device, methods such as immersion treatment, spray treatment, flow coating, roller coating, rod coating, and electrolytic deposition can be cited, but are not limited to these methods. In addition, as the drying method of the fourth step, there can be cited: a method of heating and drying using hot air, an induction heater, infrared rays, near-infrared rays, etc.; a method of drying by vacuum distillation, etc., but are not limited to these. As the temperature during heating and drying, there is no particular limitation, preferably in the range of 40 to 250°C (ambient temperature), more preferably in the range of 60 to 180°C (ambient temperature). In addition, the heating time is not particularly limited, and the most suitable conditions can be appropriately set according to the type of material used, the surface of the metal material or the amount of the base treatment agent attached to the surface, etc.

[0073] <Carbon Steel Material>

[0074] As carbon steel materials, there are no particular restrictions, and examples include steel materials that are alloys of iron and carbon and have a carbon content of 0.02% to 2.14% by mass, preferably high-carbon steel containing more than 0.95% by mass of carbon, and more preferably high-carbon chromium bearing steel materials used for mechanical components and the like. High-carbon chromium bearing steel materials are carbon steel materials with various special properties that have chromium, nickel, molybdenum, etc. added to the carbon contained in large quantities in steel. In addition, the upper limit of the carbon content of high-carbon steel is not limited, and can be less than 3% by mass, or less than 2.14% by mass.

[0075] In addition, although the present specification cites carbon steel as an example of a target material to which the surface treatment agent is applied, the target material to which the surface treatment agent of the present embodiment is applied is not limited to a metal material, and any material may be used as long as a corrosion-resistant coating is required.

[0076] (Carbon steel material with surface treatment coating)

[0077] The carbon steel material with a surface treatment film of the present embodiment has the above-mentioned surface treatment film on the surface of the carbon steel material or on the surface. The surface treatment film contains a polymer derived from an alkoxysilane (E) having an amino group and a silicone resin (A), a compound (B), a compound (C), and an amino group. It is believed that the polymer derived from an alkoxysilane (E) having an amino group in the surface treatment film achieves the effect of stably maintaining the silicone resin (A), the compound (B), and the compound (C) (adhesive effect).

[0078] In addition, the mass of compound (B) (B M ) and the mass (A) of the silicone resin (A) M )M / A M ) is within the range of greater than 0.05 and less than 3.12.

[0079] In addition, the mass (C M ) and the mass (A) of the silicone resin (A) M ) M / A M ) is within the range of 0.02 to 0.55. M ), the mass of compound (B) M ) and the mass (C) of the compound (C M ) also remains unchanged in the surface treatment film formed by the surface treatment agent.

[0080] In addition, the carbon steel material with a surface treatment film of the present embodiment may also have a base film between the carbon steel material and the surface treatment film. The base film includes one or more selected from a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, and phosphoric acid. In addition, when the above-mentioned additive is added to the base treatment agent forming the base film, the base film may also include the additive.

[0081] The carbon steel material with the surface treatment coating can be manufactured by the manufacturing method. The film thickness of the surface treatment coating is not particularly limited, and each single side is preferably in the range of 3 μm to 100 μm, and more preferably in the range of 20 μm to 80 μm. The film thickness of the surface treatment coating can be measured by observing the cross section of the coating with an electron microscope.

[0082] The above-mentioned carbon steel material with a surface treatment coating has excellent electrolytic corrosion resistance and is therefore suitable for: automotive parts such as bearings and motors; home appliance parts such as home appliance motors and reactors; OA equipment parts such as printed circuit boards and inductors; and industrial products such as medical equipment.

[0083] Example

[0084] Hereinafter, the effects of the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples.

[0085] (1) Test materials (raw materials)

[0086] The following commercially available materials were used as test materials.

[0087] (M1) High carbon chromium bearing steel SUJ2: Plate thickness 1.0 mm, carbon content 1.0 mass%

[0088] (2) Pretreatment (alkaline degreasing and cleaning)

[0089] The surfaces of various test materials were immersed in a 2% aqueous solution of an alkaline degreasing agent (Fine Cleaner E6406 manufactured by Nippon Parkersei Co., Ltd.) at 60°C for 30 seconds to remove oil and dirt on the surface. Then, the surfaces were washed with tap water, rinsed with pure water, and dried at 100°C.

[0090] (3) Preparation of surface treatment agent

[0091] The surface treatment agents of Examples 1 to 19 and Comparative Examples 1 to 5 were prepared by mixing the components as shown in Table 1. The types of the components shown in Table 1 are shown in Tables 2 to 6. The mixing amounts of the silicone resin (A) and the alkoxysilane (E) shown in Table 1 are the masses of compounds excluding the solvent and the like.

[0092] [Table 1]

[0093] Table 1: Composition of surface treatment agent

[0094]

[0095] [Table 2]

[0096] Table 2

[0097]

[0098] [Table 3]

[0099] Table 3

[0100]

[0101] [Table 4]

[0102] Table 4

[0103]

[0104] [Table 5]

[0105] Table 5

[0106]

[0107] [Table 6]

[0108] Table 6

[0109]

[0110] (4) Metal materials with surface treatment coatings

[0111] As shown in Table 7, various surface treatment agents are brought into contact with the surfaces of various test materials that have been pretreated. Afterwards, the treatment agent that has been in contact with the surface of the test material is dried at the drying temperature (ambient temperature) shown in Table 7 without washing, and the test material (test plate) having a surface treatment coating of the film thickness shown in Table 7 is prepared. In addition, the contact of the surface treatment agent is carried out by coating. In addition, as required, before contacting the surface treatment agent, various test materials that have been pretreated are immersed in the base treatment agent shown in Table 7 and dried, thereby forming a base film on the surface of the test material. In addition, the types of base treatment agents shown in Table 7 are shown in Table 8.

[0112] [Table 7]

[0113] Table 7: Preparation of test board

[0114]

[0115] [Table 8]

[0116] Table 8

[0117]

[0118] In addition, the base treatment in Table 8 was specifically performed as follows.

[0119] S1: A treatment agent prepared by diluting 3-aminopropyltriethoxysilane ("KBE-903" manufactured by Shin-Etsu Chemical Co., Ltd.) with ethanol to 10 mass % is directly applied to the test material at room temperature and then dried until it reaches 100°C (test material temperature) to form a base film.

[0120] S2: In a surface conditioning agent prepared by diluting a manganese phosphate treatment surface treatment conditioning agent ("Prepalene 55" manufactured by Japan Parker Seiki Co., Ltd.) to 0.3% by mass with tap water, various test materials were immersed for 30 seconds. Next, a manganese phosphate-based surface treatment agent ("PF-M1A" manufactured by Japan Parker Seiki Co., Ltd.) was diluted to 14% by mass with tap water, and the total acidity, free acidity, acid ratio (total acidity / free acidity) were adjusted to 50 points, 8.6 points, acid ratio (total acidity / free acidity) to 5.8, and iron component concentration to 1.5 g / L were adjusted, and the surface-conditioned iron-based metal material was immersed in a chemical conversion treatment solution heated to 97°C for 900 seconds. Next, the material was washed with tap water, and further rinsed with pure water, and the surface of the test material was dried at 100°C (ambient temperature) for 10 minutes to form a base film composed mainly of manganese phosphate and manganese iron phosphate.

[0121] (5) Evaluation test

[0122] The following evaluation tests were performed on various test plates. The results of each evaluation test are shown in Table 9. In addition, from a practical point of view, the test plates without "×" in each evaluation item shown in Table 9 were considered to be qualified. In addition, the level that could not be evaluated due to poor liquid stability and coating properties was set to "-".

[0123] <Electrolytic Corrosion Resistance after Heating>

[0124] After cutting various test plates (No. 1 to No. 34) into a size of 70 × 150 mm, they were heated in an oven at 200°C for 10 hours and then left at room temperature (25°C) for 24 hours. Then, according to JIS C2110-1: 2016, a voltage was applied to the various test plates at a voltage increase rate of 10 V / s, and the maximum voltage when the various test plates were energized was measured, and the electrolytic corrosion resistance after heating was evaluated based on the following evaluation criteria.

[0125] (Evaluation Criteria)

[0126] S: 1000V or more

[0127] A: 500 or more ~ ​​less than 1000V

[0128] B: 300V or more ~ ​​less than 500V

[0129] C: 200V or more ~ ​​less than 300V

[0130] D: less than 200V

[0131] <Adhesion test after heating>

[0132] After cutting various test plates into a size of 70×150mm, heat them in an oven at 200°C for 10 hours, and then place them at room temperature (25°C) for 24 hours. Then, cut 11 slits horizontally and vertically at intervals of 1mm on various test plates, and apply checkerboard (10×10=100 squares) grid cuts. Next, stick cellophane tape on the checkerboard cuts, then peel off the cellophane tape and measure the number of squares remaining in 100 squares. Calculate the residual rate from the measurement results, and evaluate the adhesion after heating based on the following evaluation criteria.

[0133] (Evaluation Criteria)

[0134] S: Residual rate 95% to 100%

[0135] A: Residual rate 90% or more to less than 95%

[0136] B: Residual rate 70% or more to less than 90%

[0137] C: Residual rate 50% or more to less than 70%

[0138] D: Residual rate 0% or more to less than 50%

[0139] <Electrolytic Corrosion Resistance after Sliding>

[0140] After cutting each test plate into a size of 30 × 100 mm, the treated surfaces of two test plates were overlapped with each other (contact area 30 mm × 30 mm) using a drawbead testing machine, with a pressure load of 200 kg and a surface pressure of 22.2 kg / cm 2 Next, according to JIS C2110-1:2016, a voltage was applied to the sliding surfaces of the various test plates at a voltage increase rate of 10 V / s, the maximum voltage when power was applied to each test plate was measured, and the electrolytic corrosion resistance after heating was evaluated based on the following evaluation criteria.

[0141] (Evaluation Criteria)

[0142] S: 1000V or more

[0143] A: 500 or more ~ ​​less than 1000V

[0144] B: 300V or more ~ ​​less than 500V

[0145] C: 200V or more ~ ​​less than 300V

[0146] D: less than 200V [Table 9]

[0147] Table 9: Evaluation results

[0148]

[0149] Furthermore, although the present invention has been described in detail with reference to specific embodiments, it will be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

Claims

1. A surface treatment agent for carbon steel material, comprising an organic silicone resin (A), a titanium compound (B), a barium compound (C), an aromatic hydrocarbon solvent (D) and an alkoxysilane having an amino group (E), (I) the mass (B) of the compound (B) M ) and the mass (A) of the silicone resin (A) M ) M / A M ) is within the range of 0.05 to 3.12, (II) The mass (C) of the compound (C) M ) and the mass (A) of the silicone resin (A) M ) M / A M ) is within the range of 0.02 to 0.55, (III) the mass (E) of the compound (E) M ) and the mass (A) of the silicone resin (A) M ) M / A M ) is within the range of greater than 0.01 and less than 0.

43.

2. A method for manufacturing a carbon steel material, wherein the carbon steel material has a surface treatment coating. Method for manufacturing the carbon steel material include: In a first step, the surface treatment agent according to claim 1 is brought into contact with the surface or the surface of the carbon steel material; as well as In the second step, the surface treatment agent in contact with the carbon steel material is dried to form a surface treatment film.

3. The method for producing a carbon steel material according to claim 2, in, Before the first step, the method further comprises: In the base film forming step, a base treatment agent containing a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, or phosphoric acid is brought into contact with the surface or on the surface of the carbon steel material to form a base film. 4 . A carbon steel material having a surface treatment film, which is obtained by the production method according to claim 2 or 3 , wherein the film thickness of the surface treatment film is within a range of 3 μm to 100 μm.

5. A carbon steel material having a surface treatment coating, which has a surface treatment coating on or on the surface of the carbon steel material, The surface treatment film contains a silicone resin (A), a titanium compound (B), a barium compound (C), and a polymer derived from an alkoxysilane having an amino group (E). (I) the mass (B) of the compound (B) M ) and the mass (A) of the silicone resin (A) M ) M / A M ) is within the range of 0.05 to 3.12, (II) The mass (C) of the compound (C) M ) and the mass (A) of the silicone resin (A) M ) M / A M ) is within the range of 0.02 to 0.

55.

6. The carbon steel material with a surface treatment coating according to claim 5, in, There is a base film between the carbon steel material and the surface treatment film, The base film includes at least one selected from a silane coupling agent having an amino group, a polymer of the silane coupling agent, a copolymer with the polymer, and phosphoric acid.

7. The carbon steel material with a surface treatment coating according to claim 5, in, The surface treatment film has a thickness in the range of 3 μm to 100 μm.

8. The high carbon steel material having a surface treatment coating according to any one of claims 5 to 7, in, The carbon steel material is a high carbon steel containing 0.95 mass % or more of carbon.

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