JP2006307339A - Corrosion protecting method of metallic material, highly corrosion-resistant metallic material, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a corrosion protecting method of a metallic material, a highly corrosion-resistant metallic material, and its manufacturing method in which the highly corrosion-resistant metallic material can withstand a severe corrosive environment of the same degree as that of a conventional zinc-coating, zinc-rich paint, the electric corrosion protecting method or the like, any rare metal resources such as zinc are not used, any harmful metal such as chromium is not used, and any rectifier, transformer or the like is not required. <P>SOLUTION: The corrosion protecting method of a metallic material for preventing corrosion of a metallic material comprises a step of depositing a covered layer on a surface of the metallic material. The covered layer comprises an insertion material in which alkaline metal ions and/or alkaline earth metal ions are inserted, and has electronic conductivity. It also has the characteristic of permeating alkaline metal ions and/or alkaline earth metal ions. Corrosion of the metallic material can be prevented by releasing the alkaline metal ions and/or the alkaline earth metal ions in the insertion material from the surface of the covered layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to anticorrosion technology for various metal materials such as steel and stainless steel, and substantially uses harmful metals and low reserve metal resources for metal materials that easily corrode in outdoor environments and wet environments. It relates to the anticorrosion method which protects over a long period of time. The present invention also relates to a highly corrosion-resistant metal material that does not substantially contain harmful metals or low reserve metal resources and exhibits a long-term corrosion effect, and a method for producing the same.

  The conventional anticorrosion methods for metal materials such as steel materials were mainly by plating or painting. Corrosion prevention by plating utilizes the difference in corrosion potential between the plated metal and the base metal material, and can inhibit the corrosion of scratches and coating film defects. For example, when galvanizing is performed on the surface of the steel material, the occurrence of red rust of iron can be prevented for a certain period even if a scratch reaching the surface of the steel material occurs.

  This is because zinc is a base metal and has a lower corrosion potential than iron, so that zinc corrodes earlier than iron and protects iron from corrosion. Such an anticorrosion method is generally called sacrificial anticorrosion. Therefore, corrosion does not occur, but zinc corrosion actually occurs. That is, zinc is consumed in sacrificial protection.

  However, in recent years, a decrease in the reserves of resources used for plating (for example, metallic zinc) has become apparent, and if the same plating treatment as before is applied to automobile steel plates, building materials, home appliances, etc., there will be another 20 It is expected to run out in a few years.

  By the way, since the corrosion of zinc and the like used for plating progresses rapidly particularly in an environment with a high salt concentration, the anticorrosion effect does not last long.

  Therefore, as a method for improving this, a chromate treatment method in which a surface treatment with chromic acid is conventionally performed. However, since harmful hexavalent chromium is used, a method not using it has been demanded.

  On the other hand, anti-corrosion by coating is excellent in blocking the corrosive substances such as water, oxygen and salt from the outside and preventing the corrosion current due to electrical insulation, but it is weak against scratches and peeling of the coating film. There was a problem that the progress of rust from the defect progressed all at once.

  Furthermore, there is a zinc rich paint as a paint with an enhanced anticorrosion function, and among them, there is a kind similar to a zinc rich paint not containing harmful hexavalent chromium. For example, Patent Document 1 describes an anticorrosion paint stabilized as an aqueous paint without using hexavalent chromium.

  Specifically, zinc powder 100 parts by weight, at least one phosphate ester resin selected from the group consisting of a phosphate ester of an epoxy resin and a phosphate ester of a hydroxyl group-containing resin, and a binder Patent Document 1 describes a zinc powder-containing aqueous composition containing 0 to 69.99 parts by weight, wherein the total amount of the phosphate resin and the binder is 5 to 70 parts by weight. Yes.

  However, since such a composition uses metallic zinc, it cannot cope with future depletion of zinc resources.

By the way, as an anticorrosion method of a metal material, there is an anticorrosion method of cathodic protection by electrically connecting a metal body to be protected to a power supply device in addition to the above plating and coating.
This method is used for anticorrosion of railway rails, pipelines and offshore structures.

  As this cathodic protection method, for example, in Patent Document 2, a steel material inside a concrete of a concrete structure containing salt is used as an internal electrode, an electrode installed on a surface portion of the concrete is used as a surface electrode, and between the surface electrodes, And / or, in the method of passing an electric current between the surface electrode and the internal electrode, an electrolyte material containing a water-soluble lithium compound is supplied between both electrodes, so that the molar ratio of lithium / sodium in the concrete is 0.1 or more. A method for treating concrete containing salt is described.

However, such an anticorrosion method has been difficult to maintain an effect over a long period of time. In addition, such an anti-corrosion method requires a power supply facility at all times, and requires know-how for control, so that its application range is limited.
JP 11-124520 A JP-A-8-40784

  The present invention is based on the recognition that the conventional anticorrosion (rust prevention) method alone has a limit due to global environmental problems and depletion of resources, and provides a new anticorrosion technology that solves the problems as described above. It is intended.

  Therefore, the present invention can withstand a severe corrosive environment similar to that of conventional zinc plating, zinc rich paint, and anticorrosion methods, and does not use rare metal resources such as zinc, but uses harmful metals such as chromium. Therefore, it is an object of the present invention to provide an innovative anticorrosion method that does not require equipment such as a rectifier and a transformer, a highly corrosion-resistant metal material, and a manufacturing method thereof.

The present inventors have predicted that it will not be possible to escape from the problems of protecting the global environment and depleting resources in the future only by the above conventional anticorrosion method, and a new alternative to conventional chromic acid treatment, galvanization, etc. We worked hard on research and development of anticorrosion technology.
And the above-mentioned problems can be solved by anticorrosion technology based on a new principle using an insertion material inserted with alkali metal ions and / or alkaline earth metal ions using abundant and inexpensive resources without concern for environmental pollution. I found.

That is, the present invention includes the following (1) to (28).
(1) A method for preventing corrosion of a metal material, comprising the step of forming a coating layer on the surface of the metal material, the coating layer comprising alkali metal ions and / or alkaline earth metal An insertion material having ions inserted therein and having electronic conductivity and a property of transmitting the alkali metal ions and / or the alkaline earth metal ions; A method for preventing corrosion of a metal material, in which corrosion of the metal material is prevented by releasing alkali metal ions and / or alkaline earth metal ions from the surface of the coating layer.
(2) The method for preventing corrosion of a metal material according to the above (1), wherein the surface potential of the metal material is 0.1 V or more lower than the corrosion potential of the metal material.
(3) The method for preventing corrosion of a metal material according to (1) or (2), further comprising a step of cathodic polarization of the metal material continuously or intermittently.
(4) The alkali metal ion and / or alkaline earth metal ion is at least one selected from the group consisting of lithium ion, magnesium ion and calcium ion, according to any one of (1) to (3) above. Anticorrosion method for metal materials.

(5) A highly corrosion-resistant metal material having a coating layer on the surface of the metal material, the coating layer containing an insertion material into which alkali metal ions and / or alkaline earth metal ions are inserted, and electrons A highly corrosion-resistant metal material having conductivity and a property of transmitting the alkali metal ions and / or the alkaline earth metal ions.
(6) The highly corrosion-resistant metal material according to (5), wherein the alkali metal ion and / or alkaline earth metal ion is at least one selected from the group consisting of lithium ions, magnesium ions, and calcium ions.
(7) The highly corrosion-resistant metal material according to (5) or (6), wherein a charge / discharge potential of the insertion material is −1.8 to −0.4 V with respect to a standard hydrogen electrode.
(8) The above insertion material, wherein the insertion material includes at least one selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, a metal oxide, a metal carbide, a metal nitride, a carbon material, and an organic conductive material ( The high corrosion-resistant metal material according to any one of 5) to (7).
(9) The alkali metal compound according to (8), wherein the alkali metal compound is at least one selected from the group consisting of lithium titanate, lithium ferrate, lithium vanadate, lithium niobate, lithium manganate, and lithium zirconate. High corrosion resistance metal material.
(10) The alkaline earth metal compound is calcium titanate, calcium ferrate, calcium vanadate, calcium niobate, calcium manganate, calcium zirconate, magnesium titanate, magnesium ironate, magnesium vanadate, magnesium niobate The high corrosion-resistant metal material according to (8) or (9), which is at least one selected from the group consisting of magnesium manganate and magnesium zirconate.

(11) The above (8), wherein the metal oxide is at least one selected from the group consisting of titanium oxide, zirconium oxide, iron oxide, nickel oxide, cobalt oxide, manganese oxide, tin oxide, vanadium oxide and niobium oxide. The high corrosion-resistant metal material according to any one of to (10).
(12) The highly corrosion-resistant metal material according to (11), wherein the iron oxide is at least one selected from the group consisting of FeOOH, γ-Fe ₂ O ₃ and α-Fe ₂ O ₃ .
(13) The highly corrosion-resistant metal according to any one of (8) to (12), wherein the carbon material is at least one selected from the group consisting of graphite, activated carbon, nanocarbon, mesocarbon, coke, and carbon black. material.
(14) The highly corrosion-resistant metal according to any one of (8) to (13), wherein the organic conductive material is at least one selected from the group consisting of polyacene, polyacetylene, polythiophene, polyphenylene vinylene, polyaniline, and polypyrrole. material.
(15) The highly corrosion-resistant metal material according to any one of (5) to (14), wherein the coating layer includes an organic and / or inorganic binder.

(16) The highly corrosion-resistant metal material according to (15), wherein the organic and / or inorganic binder has an anionic group.
(17) The anionic group comprises a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and a peroxy group (—OOH). The high corrosion resistance metal material according to (16), which is at least one selected from the group.

(18) The high corrosion resistance according to any one of (5) to (17), wherein the coating layer has a surface contact electrical resistance of 1 to 10 ¹⁰ Ω / cm ² under a relative humidity of 30 to 40%. Metal material.
(19) The highly corrosion-resistant metal material according to any one of (5) to (18), wherein at least one protective layer having a higher contact electric resistance value than the coating layer is provided on the surface of the coating layer.
(20) The highly corrosion-resistant metal material according to (19), wherein the protective layer is formed using at least one selected from the group consisting of a powder coating material, an electrodeposition coating material, a solvent coating material, and a water-based coating material.

(21) The highly corrosion-resistant metal material according to (19) or (20), wherein the protective layer contains the organic and / or inorganic binder, and the organic and / or inorganic binder has an anionic group.
(22) The anionic group comprises a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and a peroxy group (—OOH). The high corrosion-resistant metal material according to (21), which is at least one selected from the group.

(23) The highly corrosion-resistant metal material according to any one of (5) to (22), wherein the metal material is a steel material.
(24) Building materials, bridge members, steel towers, gates, fences, handrails, vehicle / ship exterior materials, automobile steel plates, construction machinery, automobile undercarriage members, bicycles, concrete reinforcing bars, steel pipes, rails, road sign boards, signs, The high corrosion-resistant metal material according to the above (5) to (23), which is used for guard rails, home appliance outer plates or boiler, gas or water pipes.

(25) The method for producing a highly corrosion-resistant metal material according to any one of (5) to (24) above, comprising an insertion material into which the alkali metal ions and / or the alkaline earth metal ions can be inserted. And forming a coating layer having a property of transmitting the alkali metal ions and / or the alkaline earth metal ions on the surface of the metal material, and then the metal material on which the coating layer is formed. Is cathode-polarized in an electrolytic solution containing the alkali metal ions and / or the alkaline earth metal ions, and the alkali metal ions and / or the alkaline earth metal ions are inserted into the insertion material. A process for producing a highly corrosion-resistant metal material comprising the steps.
(26) The method for producing a highly corrosion-resistant metal material according to (25), further comprising a step of removing the electrolytic solution after the cathode polarization.
(27) The method for producing a highly corrosion-resistant metal material according to any one of (5) to (24) above, wherein the insertion material into which the alkali metal ions and / or the alkaline earth metal ions are inserted is used. The manufacturing method of the highly corrosion-resistant metal material which forms the said coating layer by apply | coating the containing composition to the surface of the said metal material.
(28) The height according to any one of (25) to (27), further including a step of forming at least one protective layer having a higher contact electric resistance value than the coating layer on the surface of the coating layer. A method for producing a corrosion-resistant metal material.

  According to the method for preventing corrosion of a metal material, the highly corrosion-resistant metal material and the method for producing the same according to the present invention, conventional methods such as chromate treatment with hexavalent chromium, galvanized material, zinc rich paint, and cathodic protection, which have been widely used so far. Instead, it is possible to prevent metal corrosion even in the severe corrosive environment similar to these conventional methods, and to prevent environmental pollution for many parts that could not be protected without these conventional methods. However, corrosion protection is possible without using rare metal resources. Further, even in the case of a building or structure that is difficult to repair by plating or painting, it is possible to prevent corrosion for a longer period of time than before by performing the cathode polarization treatment periodically.

The present invention is described in detail below.
The present invention is a method for preventing corrosion of a metal material, a highly corrosion-resistant metal material, and a method for producing the same.

First, the anticorrosion method of the present invention and the highly corrosion resistant metal material of the present invention will be described.
The anticorrosion method of the present invention is a metal material anticorrosion method for preventing corrosion of a metal material, and includes a step of forming a coating layer on the surface of the metal material, the coating layer comprising alkali metal ions and / or Containing an insertion material into which alkaline earth metal ions are inserted, and having the property of transmitting the alkali metal ions and / or the alkaline earth metal ions, and the alkali metal ions in the insertion material and In the method of preventing corrosion of the metal material, the alkaline earth metal ions are released from the surface of the coating layer to prevent corrosion of the metal material.

  The highly corrosion-resistant metal material of the present invention is a highly corrosion-resistant metal material having a coating layer on the surface of the metal material, and the alkali metal ions and / or the alkaline earth metal ions are inserted into the coating layer. It is a highly corrosion-resistant metal material containing an insertion material and having the property of transmitting the alkali metal ions and / or the alkaline earth metal ions.

<Metal material>
The metal material used in the present invention is not particularly limited, and examples thereof include steel, stainless steel, plated steel, zinc, aluminum, and copper. Steel materials (iron and stainless steel, zinc on the surface thereof, etc.) It is most preferable that the steel be plated with various types of plating. This is because a steel material exhibits a relatively low corrosion potential, and an oxide film formed in an atmosphere containing oxygen and moisture (for example, in the air) has no corrosion prevention effect, so that cathodic protection is effective.

  Moreover, it is preferable that the surface potential of such a metal material is 0.1 V or more lower than the corrosion potential of the metal material. This is because the anticorrosion effect becomes higher.

  The surface potential is measured in an aqueous solution of NaCl or KCl using a potentiostat and using a standard hydrogen electrode or a saturated sweet potato electrode as a standard electrode.

The anticorrosion method of this invention has the process of forming a coating layer on the surface of such a metal material.
The highly corrosion-resistant metal material of the present invention has a coating layer on the surface of such a metal material.

<Coating layer>
In the present invention, the coating layer contains an insertion material.

<Insertion material>
Insertion materials used in the present invention include alkali metal ions such as lithium ions and / or alkaline earth metal ions such as magnesium ions and calcium ions and hydrogen ions via a solid / electrolyte (liquid or solid) physical interface. A material that allows ions to be taken in and out (intercalation or deintercalation) while maintaining a solid form. Here, high specific surface area materials such as activated carbon and nanocarbon, and porous materials are also included.

  The insertion material used in the present invention is not particularly limited as long as the alkali metal ion and / or the alkaline earth metal ion can be inserted by a method described later. It is preferable to include at least one selected from the group consisting of a compound, a metal oxide, a metal carbide, a metal nitride, a carbon material, and an organic conductive material. This is because these substances easily insert or adsorb alkali metal ions or alkaline earth metal ions between layers, between particles, or in fine pores.

  Here, the alkali metal compound may be a metal compound containing an alkali metal element (lithium, sodium, potassium, rubidium, cesium, francium). For example, lithium titanate, lithium ferrate, lithium vanadate, niobium Examples thereof include lithium oxide, lithium manganate, lithium zirconate, lithium cobaltate, lithium nickelate, sodium ferrate, potassium titanate, sodium niobate, cesium titanate, and rubidium manganate.

  In such an alkali metal compound, at least one selected from the group consisting of lithium titanate, lithium ferrate, lithium vanadate, lithium niobate, lithium manganate and lithium zirconate is used as the insertion material used in the present invention. It is preferable to use it. The reason is that it is easy to make a compound composed of layered crystals, and lithium ions can be easily inserted and removed. Further, when a steel material is used as the metal material, this lithium ion can be inserted and desorbed at a slightly lower potential than the corrosion potential of iron, which is more preferable.

  The alkaline earth metal compound may be any metal compound containing an alkaline earth metal element (beryllium, magnesium, calcium, strontium, barium, radium). For example, calcium titanate, calcium ferrate, vanadic acid Calcium, calcium niobate, calcium manganate, calcium zirconate, magnesium titanate, magnesium ironate, magnesium vanadate, magnesium niobate, magnesium manganate, magnesium zirconate, barium titanate, strontium titanate, barium niobate, etc. Can be illustrated.

In such alkaline earth metal compounds, calcium titanate, calcium ferrate, calcium vanadate, calcium niobate, calcium manganate, calcium zirconate, magnesium titanate, magnesium ironate, magnesium vanadate, magnesium niobate, It is preferable to use at least one selected from the group consisting of magnesium manganate and magnesium zirconate as the insertion material used in the present invention. Furthermore, if a steel material is used as the metal material, the insertion and desorption potentials of ions such as Mg ²⁺ and Ca ²⁺ are slightly lower than the corrosion potential of iron, so that the cathodic protection effect is increased, which is more preferable.

  The metal oxide is not particularly limited, but is preferably a metal oxide that is stable at a neutral to weak alkaline pH. For example, titanium oxide, zirconium oxide, iron oxide, nickel oxide, cobalt oxide, oxidation Examples thereof include manganese, tin oxide, vanadium oxide, niobium oxide, hafnium oxide, molybdenum oxide, tungsten oxide, lanthanum oxide, yttrium oxide, cerium oxide, samarium oxide, and neodymium oxide.

  In such a metal oxide, at least one selected from the group consisting of titanium oxide, zirconium oxide, iron oxide, nickel oxide, cobalt oxide, manganese oxide, tin oxide, vanadium oxide, and niobium oxide is used in the insert. It is preferable to use it as an application material. The reason is that it is easy to form a layered compound having conductivity.

Further, the iron oxide is preferably at least one selected from the group consisting of FeOOH, γ-Fe ₂ O ₃ and α-Fe ₂ O ₃ . When these iron oxides are used, and when a steel material is used as a metal material, the insertion and desorption potentials of alkali metal ions and alkaline earth metal ions are suitable for corrosion protection of this steel material. The value is more preferably 1.2 V / SHE.

The metal carbide may be any conductive metal carbide capable of inserting ions such as Li ⁺ (alkali metal ions and / or alkaline earth metal ions described later) into its structure. Tungsten, titanium carbide, molybdenum carbide, zirconium carbide and the like can be exemplified.

  In such a metal carbide, it is preferable to use at least one selected from the group consisting of boron carbide, tungsten carbide and titanium carbide as an insertion material used in the present invention. The reason is that the amount of ions that can be inserted is large.

Similarly, the metal nitride may be any conductive metal nitride that can insert ions such as Li ⁺ into its structure. For example, titanium nitride, chromium nitride, silicon nitride, niobium nitride, iron nitride Examples thereof include zirconium nitride.

  In such a metal nitride, it is preferable to use at least one selected from the group consisting of titanium nitride, chromium nitride, silicon nitride, and niobium nitride as the insertion material used in the present invention. The reason is that the amount of ions that can be inserted is large.

In addition, the carbon material is a crystalline material which can insert ions such as Li ⁺ , Mg ^{2+ and the} like (an alkali metal ion and / or an alkaline earth metal ion described later) between the layers, and is an amorphous material in which these ions are inserted. Any carbon material having a space that can be inserted may be used. Examples thereof include graphite, activated carbon, nanocarbon, mesocarbon, coke, and carbon black.

In such a carbon material, it is preferable to use at least one selected from the group consisting of graphite, activated carbon, nanocarbon, mesocarbon, coke and carbon black as the insertion material used in the present invention. The reason is that ions such as Li ⁺ are easily inserted between the layers of the crystalline carbon material, or these ions are easily inserted between voids and particles in the structure.

  The organic conductive material is an organic material having a conjugated double bond in its molecular skeleton, and may be any organic conductive material that can move electrons depending on its structure. For example, polyacene, polyacetylene, polythiophene, polyphenylene vinylene And polyaniline, polypyrrole, and those doped with a conductive carrier.

In such an organic conductive material, it is preferable to use at least one selected from the group consisting of polyacene, polyacetylene, polythiophene, polyphenylene vinylene, polyaniline and polypyrrole as an insertion material used in the present invention. The reason is that a large amount of ions such as Li ⁺ and Mg ²⁺ can be inserted.

The size of such an insertion material is not particularly limited, but preferably has a particle diameter of several nm to several μm. The reason is that the actual surface area is large and ions can be quickly inserted and removed.
Here, the particle diameter is a value measured with a microscope or an electron microscope.

  Such an insertion material used in the present invention preferably has a charge / discharge potential of −1.8 to −0.4 V with respect to a standard hydrogen electrode. If this potential is too large, the cathodic protection effect is weakened. Conversely, if the potential is too small, hydrogen gas may be generated when it comes into contact with the aqueous solution. When the metal material is a steel material, a particularly preferable range of the charge / discharge potential is −1.5 to −0.7V.

Insertion materials having a charge / discharge potential in such a range include FeOOH such as γ-FeOOH, iron oxides such as γ-Fe ₂ O ₃ and α-Fe ₂ O ₃ , LiV ₃ O ₈ (lithium vanadate). There are alkali metal-containing compounds such as LiNb ₂ O ₅ (lithium niobate) and metal oxides such as VO ₂ and SnO ₂ , and these are insertion materials that can be particularly preferably used in the present invention.

Note that the charge / discharge potential here is a potential at which insertion and desorption of ions such as Li ⁺ are mainly performed, and can be measured as a potential range in which a potential change is small when charging or discharging with a constant current is performed. It is a measured value when measured by a method of plotting a charge-discharge curve (potential-time) with a constant current of 10 mA / dm ² and reading the potential at which the potential becomes nearly flat.

  Further, such an insertion material is preferably contained in the coating layer in an amount of 50% by mass or more, and more preferably more than 50% by mass. Furthermore, the content is more preferably 75% by mass or more, and most preferably 85% by mass or more. Moreover, as will be described later, the coating layer may be made of only an insertion material.

  In such an insertion material, the following alkali metal ions and / or alkaline earth metal ions are inserted.

<Alkali metal ions, alkaline earth metal ions>
In the present invention, alkali metal ions and / or alkaline earth metal ions are lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, francium ions, beryllium ions, magnesium ions, calcium ions, strontium ions, barium ions. And at least one ion selected from the group consisting of radium ions.

In such alkali metal ions and / or alkaline earth metal ions, the ions inserted into the insertion material are preferably at least one selected from the group consisting of lithium ions, magnesium ions and calcium ions, More preferably, it is lithium ion.
The reason is that these ions have a small ion radius, so that they can be easily inserted into the insertion material and a large amount can be inserted. Furthermore, as described later, the carbonate layer formed on the surface of the coating layer is difficult to dissolve in water.

As long as this coating layer has the property of permeating the alkali metal ions and / or alkaline earth metal ions described above, the material (material of the material other than the insertion material) is not particularly limited.
In addition, it is preferable that the material itself that forms the coating layer has such a property of transmitting ions, but even if it does not, the insertion material and organic and / or inorganic binders described later are used. By setting the mixing ratio (mass ratio) to 50: 1 to 1: 1, it is possible to have a property of transmitting alkali metal ions and / or alkaline earth metal ions as the entire coating layer.

As a material for forming such a coating layer, for example, as an organic binder, polyester resin, epoxy resin, acrylic resin, urethane resin, phenol resin, nylon resin, polyethylene / polypropylene resin, melamine resin And urea resins, polyimide resins, silicone resins, fluorine resins, chlorine resins, polysulfide resins, and the like. In addition, as inorganic binder, water glass such as lithium silicate, potassium silicate, sodium silicate, oxide sol such as silica sol, alumina sol, zirconia sol, titanium oxide sol, clay mineral such as synthetic smectite, sepiolite, aluminum phosphate, zirconium phosphate And phosphoric acid compounds such as cement and mortar.
Moreover, you may mix and use these arbitrarily. Furthermore, you may contain a metal particle, a fiber, glass, etc. The content of the metal particles, fibers, glass and the like is preferably 50% by mass or less, and more preferably 15% by mass or less.

The organic binder and / or inorganic binder preferably contains a compound having an anionic group. The reason is that the alkali metal ions and / or alkaline earth metal ions inserted in the coating layer can be captured, and rapid elution of these ions can be suppressed to improve the sustainability of the cathode effect. is there.
Examples of the anionic group include a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), a peroxy group (—OOH), iminodiacetic acid, and the like. Can be mentioned. Among these, this anionic group is a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and a peroxy group (—OOH). It is preferably at least one selected from the group consisting of

Furthermore, it is preferable that this anionic group further has chelating properties. That is, it is preferable that the organic binder and / or the inorganic binder contains a chelate compound having a plurality of anionic groups. The reason is that the organic binder and / or the inorganic binder increases the degree of capturing the alkali metal ions and / or alkaline earth metal ions inserted into the coating layer.
When the kind of the alkali metal ion and / or alkaline earth metal ion is at least one selected from the group consisting of lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion and francium, the plurality of anions The functional group is preferably at least two selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and an iminodiacetic acid group.
When the alkali metal ion and / or alkaline earth metal ion is beryllium, magnesium ion, calcium ion, strontium ion, barium ion or radium ion, the plurality of anionic groups are carboxyl groups (- COOH), a sulfo group (—SO ₃ H), and an iminodiacetic acid group are preferred.

  The coating layer preferably contains the organic binder and / or the inorganic binder in an amount of 50% by mass or less, more preferably less than 50% by mass, based on the total mass of the coating layer. The content is more preferably 25% by mass or less, and most preferably 15% by mass or less. If this content is too high, the electron conductivity of the coating layer is insufficient, and the cathode effect tends to decrease.

  A coating layer is formed by, for example, applying a material (composition) containing an insertion material in which such alkali metal ions and / or alkaline earth metal ions are inserted or can be inserted onto the surface of the metal material. As a method of performing, the method shown in the method for producing a highly corrosion-resistant metal material of the present invention described later can be preferably applied.

  Moreover, although the thickness of such a coating layer is not specifically limited, 0.1-1000 micrometers is preferable. Moreover, when using mortar as a binder, it is preferable that it is several tens of micrometers-thickness of several cm. The reason is that since the mortar contains many alkali ions and alkaline earth metal ions, a sufficient anticorrosive effect can be obtained by increasing the film thickness.

Such a coating layer has electron conductivity. Here, “having electronic conductivity” means that the volume resistivity measured in a room temperature and normal pressure is 10 ⁻² to 10 ¹⁰ Ω · cm.

  Moreover, since such a coating layer moves an electron from the insertion material to the surface of the said metal material, it is preferable that electron conductivity is high. It is preferable that the composition contains a conductive binder because electron conductivity is further increased. That is, it is preferable that this coating layer contains a conductive binder because the electronic conductivity is further increased.

Therefore, it is preferable that the volume resistivity measured in the room | chamber interior under normal temperature and normal pressure is 1-10 < ¹⁰ > ohm * cm that electronic conductivity is high.

In addition, such a coating layer preferably has a surface contact electrical resistance of 1 to 10 ¹⁰ Ω / cm ² under a relative humidity of 30 to 40%, and a range of 10 to 10 ¹⁰ Ω / cm ² . Further preferred.
If the contact electric resistance is too low, the electrons in the coating layer are liable to be lost by reacting with oxygen or water in the air, which is not preferable. In this way, when the contact electrical resistance value on the surface of the coating layer is too low, a protective layer, which will be described later, is formed by coating or painting a high electrical resistance material such as a resin or attaching an oxide or the like to the surface by post treatment It is preferable to increase the contact electric resistance value.

  Note that the contact electric resistance referred to here is a potential difference obtained by applying a load of 100 g to a graphite electrode having a diameter of 0.9 mmφ in an environment with a relative humidity of 30 to 40% and bringing the graphite electrode into contact with the surface of the coating layer perpendicularly. (12V) is given, and is calculated from the value of current flowing between the metal material and the graphite electrode.

  Moreover, it is preferable that such a coating layer has at least one protective layer having a higher contact electric resistance value than the coating layer on the surface thereof. Furthermore, it is preferable that the contact electrical resistance value of the protective layer is five times higher than that of the coating layer. Further, it is more preferable that the alkali metal ions and / or alkaline earth metal ions of the protective layer have a lower permeability than the coating layer.

  By having such a protective layer, it is possible to prevent wasteful consumption of electrons due to the supply or reduction reaction of oxygen or water brought from the surface (external environment) of the coating layer. The corrosion resistance of the high corrosion resistance material is improved. Moreover, the corrosion resistance effect by the anticorrosion method of this invention improves more. Furthermore, these corrosion resistances are maintained for a longer period.

In addition, the material of this protective layer, the formation method, etc. may be the same as that of the said coating layer, and may contain the said insertion material.
In this case, it is preferable because an operation of reinserting and regenerating alkali metal ions and / or alkaline earth metal ions as described later becomes easy.

  As will be described later, a carbonate layer is formed on the surface of the coating layer of the present invention. This carbonate layer can also be regarded as a protective layer.

  The protective layer is preferably formed using at least one selected from the group consisting of a powder coating material, an electrodeposition coating material, a solvent coating material, and a water-based coating material. The reason is that a film can be easily formed industrially by these methods.

Moreover, when this protective layer contains the said organic binder and / or an inorganic binder, it is preferable that this organic binder and / or an inorganic binder have an anionic group. The reason is that the alkali metal ions and / or alkaline earth metal ions inserted in the covering layer and / or the protective layer are captured, and the rapid elution of these ions is suppressed, thereby maintaining the sustainability of the cathode effect. This is because it can be improved.
Examples of the anionic group include a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), a peroxy group (—OOH), iminodiacetic acid, and the like. Can be mentioned. Among these, this anionic group is a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and a peroxy group (—OOH). It is preferably at least one selected from the group consisting of

Furthermore, it is preferable that this anionic group further has chelating properties. That is, it is preferable that the organic binder and / or the inorganic binder contains a chelate compound having a plurality of anionic groups. The reason is that the organic binder and / or the inorganic binder increases the degree of capturing the alkali metal ions and / or alkaline earth metal ions inserted into the coating layer and / or the protective layer.
When the kind of the alkali metal ion and / or alkaline earth metal ion is at least one selected from the group consisting of lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion and francium, the plurality of anions The functional group is preferably at least two selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and an iminodiacetic acid group.
When the alkali metal ion and / or alkaline earth metal ion is beryllium, magnesium ion, calcium ion, strontium ion, barium ion or radium ion, the plurality of anionic groups are carboxyl groups (- COOH), a sulfo group (—SO ₃ H), and an iminodiacetic acid group are preferred.

  Moreover, although the thickness of a protective layer is not specifically limited, It is preferable that the sum total of the thickness of the said coating layer and the said protective layer is 0.1-1000 micrometers.

Moreover, such a protective layer preferably has a surface contact electrical resistance of 10 ⁵ Ω / cm ² or more, more preferably 10 ⁸ Ω / cm ² or more, under a relative humidity of 30 to 40%. The upper limit is not particularly limited, but is preferably 10 ¹⁸ Ω / cm ² or less, and more preferably 10 ¹² Ω / cm ² or less.

The reason why the metal material is anticorrosive by the anticorrosion method of the present invention and the reason why the high corrosion resistance metal material of the present invention has high corrosion resistance are presumed as follows.
Since the coating layer of the present invention has a property of permeating alkali metal ions and / or alkaline earth metal ions, alkali metal ions and / or alkaline earth metal ions are removed from the insertion material in a corrosive use environment. When the alkali metal ions and / or alkaline earth metal ions are inserted into the insertion material, electrons stored inside are also transferred from the coating layer to the surface of the metal material. .
And, the surface of the metal material is kept at a base potential that does not corrode, and the cathodic protection effect is exhibited. In addition, when these alkali metal ions and / or alkaline earth metal ions move to the surface of the coating layer by diffusion, they react with carbon dioxide in the air to form a stable protective carbonate-based film. To do. And by preventing side reactions such as generation of hydrogen gas and reduction reaction of dissolved oxygen, the anticorrosion effect is sustained.

  The coating layer of the present invention is made of a material containing an insertion material into which alkali metal ions and / or alkaline earth metal ions are inserted, and this material contains only the insertion material. Is also within the scope of the present invention.

Moreover, in such a highly corrosion-resistant metal material of the present invention, it is preferable that the metal material is cathode-polarized continuously or intermittently.
That is, in the anticorrosion method of the present invention, it is preferable to further provide a step of cathodic polarization of the metal material continuously or intermittently.
In the coating layer of the present invention, alkali metal ions and / or alkaline earth metal ions are released from the surface, and almost all of them are released by long-term use. Unlike zinc plating, the effect can be restored again.
Moreover, it is preferable to make the surface potential of the metal material lower than the corrosion potential of the metal material by such a method.
A specific method of cathodic polarization is the same as that shown in the method for producing a highly corrosion-resistant metal material of the present invention described later.

  Therefore, if the anticorrosion method of the present invention and the highly corrosion-resistant metal material of the present invention are applied to conventional anticorrosion methods (cathodic anticorrosion methods, etc.), the conventional anticorrosion methods (cathodic anticorrosion methods, etc.) always require connection of a power source. However, the effect can be sustained only by intermittent and periodic energization. The anticorrosion method of the present invention and the highly corrosion-resistant metal material of the present invention can be used in combination with solar cells, wind power generation facilities, and other intermittent power generation devices that have been difficult to use.

The highly corrosion-resistant metal material of the present invention is a building material, a bridge member, a steel tower, a gate, a fence, a handrail, a vehicle / ship exterior material, an automobile steel plate, a construction machine, an automobile undercarriage member, a bicycle, a concrete rebar, a steel pipe, a rail, It can be preferably used for road sign boards, signboards, guardrails, home appliances outer panels or boilers, gas and water pipes.
Moreover, it can be used for general metal materials including iron-based materials other than such applications. In addition, by providing an optical semiconductor layer such as titanium oxide as a protective layer, it is possible to obtain a photocathode anticorrosive effect that maintains the antirust function by ultraviolet rays and light.

Next, a method for producing a highly corrosion-resistant metal material of the present invention (hereinafter also simply referred to as “the production method of the present invention”) will be described.
The manufacturing method of the present invention has the following two aspects. Hereinafter, when the term “the production method of the present invention” is simply indicated, these two aspects are included.
In addition, the method for producing the high corrosion resistance metal material of the present invention is not limited to the production method of the present invention described below. The production method of the present invention is a preferred embodiment of the above-described method for producing a highly corrosion-resistant metal material of the present invention.

  1st aspect of the manufacturing method of this invention is a manufacturing method of the highly corrosion-resistant metal material of this invention, Comprising: The said insertion material which can insert the said alkali metal ion and / or the said alkaline-earth metal ion is included, and A step of forming a coating layer having a property of transmitting the alkali metal ions and / or the alkaline earth metal ions on the surface of the metal material, and then the metal material on which the coating layer is formed is converted to the alkali. A step of cathodic polarization in an electrolytic solution containing metal ions and / or alkaline earth metal ions, and inserting the alkali metal ions and / or alkaline earth metal ions into the insertion material. This is a method for producing a highly corrosion-resistant metal material.

  A second aspect of the production method of the present invention is a method for producing a highly corrosion-resistant metal material of the present invention, which contains an insertion material into which the alkali metal ions and / or the alkaline earth metal ions are inserted. It is a manufacturing method of the highly corrosion-resistant metal material which forms the said coating layer by applying a composition on the surface of the said metal material.

  Metal materials, alkali metal ions and / or alkaline earth metal ions used in the production method of the present invention, insertion materials, types of components of the composition, preferred embodiments, mixing ratio of the composition, thickness of the coating layer All of them are the same as the above-described highly corrosion-resistant metal material of the present invention.

The insertion material used here is preferably manufactured by the following method. For example, γ-FeOOH is preferably obtained by blowing air while keeping a solution made weakly acidic by coexisting iron powder in a ferrous chloride aqueous solution at about 70 ° C. Γ-Fe ₂ O ₃ can be obtained by further drying and firing the γ-FeOOH thus obtained at about 260 ° C.

  First, an insertion material into which the alkali metal ion and / or the alkaline earth metal ion can be inserted according to the first aspect of the production method of the present invention, and the alkali metal ion and / or the alkaline earth metal is inserted. A process of forming a coating layer having a property of transmitting metal ions on the surface of the metal material will be described.

A method for forming the coating layer on the surface of the metal material is not particularly limited. For example, a composition containing an insertion material into which alkali metal ions and / or alkaline earth metal ions can be inserted and the organic and / or inorganic binder is applied to the surface of the metal material by a conventional method such as stainless steel wire. The coating layer can be formed by coating using a bar.
Moreover, it is preferable to dry on the conditions of about 50-120 degreeC after the said coating layer formation.

  Moreover, as a method of forming the coating layer on the surface of the metal material, in addition to the above steps, electrolytic deposition from an aqueous solution, chemical conversion treatment, electroless liquid phase deposition, oxidation treatment by heat treatment, or a combination thereof An example is a method in which a film of an insertion material is directly formed on the surface of the metal material by treatment. This method is preferable particularly when an insertion material of iron oxide or metal oxide is used.

For example, when α-Fe ₂ O ₃ is used as an insertion material, the surface of the metal material to be processed is immersed in an iron salt aqueous solution such as a ferric nitrate aqueous solution and subjected to cathode electrolysis using this as a cathode. A coating layer of FeOOH is formed on the substrate, and then dried (baked) at 100 to 400 ° C. in air. In this case, it is preferable that an oxidizing agent such as nitrate ion or hydrogen peroxide is contained in the electrolytic solution because the pH rises on the cathode surface and FeOOH is easily deposited.

Next, the metal material on which the coating layer is formed according to the first aspect of the manufacturing method of the present invention is cathodically polarized in an electrolytic solution containing the alkali metal ions and / or the alkaline earth metal ions, The step of inserting the alkali metal ions and / or the alkaline earth metal ions into the insertion material will be described.
This step is performed after the step of forming the coating layer on the surface of the metal material.

A preferred embodiment in this step will be described with reference to FIG.
In FIG. 1, a highly corrosion resistant material 1 and a graphite plate 2 are inserted into an electrolytic cell 10 and completely immersed in an electrolytic solution 5 containing lithium ions. Here, the highly corrosion-resistant metal material 1 is manufactured in the first step, and has a coating layer 12 on the surface of the stainless steel plate 11. Further, the coating layer 12 contains lithium titanate.

  The high corrosion resistance material 1 and the graphite plate 2 are installed inside the electrolytic cell 10 with the coating layer 12 and the graphite plate 2 sandwiching the separator 3 made of a porous organic material. Further, the high corrosion resistance metal material 1 and the graphite plate 2 are connected to a rectifier 15, and the graphite plate 2 is connected to the positive electrode, and the stainless steel plate 11 of the high corrosion resistance metal material 1 is connected to the negative electrode.

  According to such an embodiment shown in FIG. 1, lithium ions in the electrolytic solution 5 are taken into the lithium titanate in the coating layer 12 that is connected to the negative electrode and is cathode-polarized by electrolysis.

  In this way, the alkali metal ions and / or the alkaline earth metal ions (lithium ions) can be inserted into the insertion material (lithium titanate).

  Cathodic polarization is not particularly limited to the above-described embodiment, and can be performed by a conventionally known method.

Next, the 2nd aspect of the manufacturing method of this invention is demonstrated.
In the second aspect of the production method of the present invention, for example, a composition containing an insertion material into which alkali metal ions and / or alkaline earth metal ions are inserted, the organic and / or inorganic binder, and the like, The coating layer can be formed by coating the surface of the metal material using a conventional method, for example, a stainless wire bar.

A specific example is shown about the 2nd aspect of the manufacturing method of this invention.
An aqueous alkaline salt solution such as lithium hydroxide is added to an aqueous solution of a water-soluble iron salt such as ferric nitrate to form a precipitate of FeOOH, which is washed as necessary and dried at 100 to 400 ° C. (calcined) ) In this way, α-Fe ₂ O ₃ which is one of particularly preferred materials in the present invention can be produced. This α-Fe ₂ O ₃ has lithium ions inserted therein.
The α-Fe ₂ O ₃ thus obtained is pulverized and mixed with an appropriate binder component and solvent component to obtain a composition for forming a coating layer containing an insertion material. And the highly corrosion-resistant metal material of this invention can be manufactured by apply | coating this composition to the surface of a metal material by a well-known method.

Moreover, in the manufacturing method of this invention, it is preferable to further comprise the process of removing the said electrolyte solution after the said cathode polarization.
Specifically, the electrolytic solution can be removed by washing with deionized water or replacing with an organic solvent such as alcohol.

  Moreover, in the manufacturing method of this invention, it is preferable to further comprise the process of forming at least 1 layer of protective layers whose contact electrical resistance value is higher than the said coating layer on the surface of the said coating layer.

  Here, the material of the protective layer, the forming method, and the definition of the contact electric resistance value are the same as those of the high corrosion resistance metal material of the present invention.

  Hereinafter, the anticorrosion method for a metal material, the highly corrosion-resistant metal material and the method for producing the same according to the present invention will be described with reference to examples.

<Example 1>
Lithium titanate (Li ₄ Ti ₅ O ₁₂ ) particles (manufactured by Titanium Industry Co., Ltd., LT-FP: average particle diameter of about 1 μm) were used as the insertion material.
Further, water was added to 90 g of this lithium titanate, 10 g of conductive carbon powder, and 60 g of polyvinylidene chloride emulsion (produced by Asahi Kasei Chemicals Co., Ltd., Saran latex, solid content concentration: 20% by mass) as a binder. A total of 200 g was uniformly mixed to obtain a coating for forming a coating layer.
Next, this paint was uniformly applied to the surface of a steel plate (SPCC: 70 × 150 × 0.8 mm) degreased and cleaned with an alkali cleaner (manufactured by Nippon Parkerizing Co., Ltd., FC-4360) with a stainless wire bar. And it dried at 80 degreeC further, and the coating layer about 20 micrometers thick was formed in the steel plate surface. The steel plate thus obtained is referred to as a coated steel plate 1.
The coated steel sheet 1 produced in this way was subjected to cathodic electrolysis in a mixed non-aqueous electrolyte solution of ethylene carbonate, dimethyl carbonate and diethyl carbonate containing lithium hexafluorophosphate (LiPF ₆ ) to obtain a test plate 1. The specific apparatus used for the treatment was the same as in FIG. 1, and a graphite plate was used for the positive electrode. Cathodic electrolysis was performed at a voltage of 3 V for 20 minutes, and lithium ions were inserted into the coating layer. Here, the contact electric resistance value of the coating layer of the test plate 1 was 30 Ω / cm ² .
The test plate 1 thus obtained was subjected to a corrosion resistance test.
This electrical contact resistance value is obtained by applying a load of 100 g to a graphite electrode having a diameter of 0.9 mmφ in an environment with a relative humidity of 30 to 40%, and bringing the graphite electrode and the test plate into contact with each other perpendicular to the surface of the test plate. (12V) is given, and is calculated from the current value flowing between the test plate and the graphite electrode.

<Example 2>
Artificial graphite fine powder (manufactured by Showa Denko KK, SCMG) was used as the insertion material.
Then, 50 g of the artificial graphite fine powder and 8 g of the polyvinylidene fluoride powder as the binder were further mixed with water to make a total of 100 g to obtain a coating layer forming coating material.
Next, the same steel plate as in Example 1 was degreased and washed by the same method, and a coating layer was formed by the same method. This is referred to as a coated steel plate 2. The thickness of the obtained coating layer was about 80 μm.
The coated steel plate 2 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 2. Here, the contact electrical resistance value of the coating layer was 60 Ω / cm ² .
The test plate 2 thus obtained was subjected to a corrosion resistance test.

<Example 3>
Α-Fe ₂ O ₃ was prepared as an insertion material.
First, 60 g of ferric nitrate (Fe (NO ₃ ) ₃ .9H ₂ O) was dissolved in 500 g of distilled water, and 135 g of an 8% aqueous lithium hydroxide solution was added thereto and stirred. Further, 20 g of a 1% aqueous solution of lithium peroxide (Li ₂ O ₂ ) was added to obtain a FeOOH precipitate. This was washed, filtered with suction, separated from the precipitate, dried, and calcined at about 300 ° C. In this way, α-Fe ₂ O _{3 was} adjusted. The precipitate after firing was pulverized to 3 μm or less and confirmed to be α-Fe ₂ O ₃ by X-ray diffraction.
8 g of α-Fe ₂ O ₃ thus prepared, 0.1 g of conductive carbon powder, and 5 g of water-soluble phenol resin (concentration: 50%, manufactured by Gunei Chemical Industry Co., Ltd.) as a binder, Further, water was added to make a total of 30 g, which was uniformly mixed to obtain a coating layer forming coating material.
Next, the same steel plate as in Example 1 was degreased and washed by the same method, and a coating layer was formed by the same method. This is referred to as a coated steel plate 3. The thickness of the obtained coating layer was about 10 μm.
The coated steel plate 3 produced in this way was electrolyzed in the same manner as in Example 1 to obtain a test plate 3. The only difference from Example 1 was that the voltage was changed from 3 V to 2.5 V. All other conditions were electrolyzed in the same manner as in Example 1. Here, the contact electrical resistance value of the coating layer was 15 Ω / cm ² .
The test plate 3 thus obtained was subjected to a corrosion resistance test.

<Example 4>
30 g of ferric nitrate (Fe (NO ₃ ) ₃ · 9H ₂ O) and 20 g of sodium nitrate were dissolved in distilled water to 1000 g, and an electrolytic treatment was performed using this as an electrolytic solution.
Here, the same steel sheet as in Example 1 was degreased and washed by the same method as a cathode, and a carbon electrode was used as an anode counter electrode, and an electrolytic treatment was performed at a voltage of 4 V for 10 minutes.
Then, the steel plate used for the cathode was washed with water, dried, and fired at 200 to 300 ° C. to form an α-Fe ₂ O ₃ coating layer on the steel plate surface. The steel plate thus obtained is referred to as a coated steel plate 4. The thickness of this coating layer was 1 to 3 μm.
The coated steel plate 4 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 4. The difference from Example 1 is that the electrolyte used was an aqueous electrolyte containing 10 g / L of magnesium chloride, and that the electrolysis time was 10 minutes. All other conditions were the same as in Example 1. Electrolysis was done in the same way. Here, the contact electric resistance value of the coating layer was 3Ω / cm ² .
The test plate 4 thus obtained was subjected to a corrosion resistance test.

<Example 5>
Γ-FeOOH was prepared as an insertion material.
First, 80 g of ferrous chloride (FeCl ₂ .nH ₂ O) was allowed to coexist with 3 g of iron powder to adjust the pH to be weakly acidic. Γ-FeOOH was obtained by continuously blowing air while maintaining such a solution at about 70 ° C.
10 g of γ-FeOOH prepared in this way, 0.5 g of conductive carbon powder, 15 g of epoxy resin emulsion (manufactured by Hitachi Chemical Co., Ltd., W790) as a binder, and water added to a total of 35 g The coating was uniformly mixed to form a coating layer forming paint.
Next, this paint was uniformly applied to the surface of a weather-resistant steel plate (Shin Nippon Steel Corp. corten steel: 70 × 150 × 5 mm) degreased and washed in the same manner as in Example 1 with a stainless wire bar. And it dried at 80 degreeC further, and formed the coating layer about 40 micrometers thick on the surface of a weather-resistant steel plate. This is referred to as a coated steel plate 5.
The coated steel plate 5 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 5. The only difference from Example 1 is that an aqueous electrolyte solution containing 20 g / L of calcium chloride was used as the electrolyte solution and that the voltage was set to 2.5 V. All other conditions were the same as in Example 1. It is. Here, the contact electrical resistance value of the coating layer was ²⁰ Ω / cm ² .
The test plate 5 thus obtained was subjected to a corrosion resistance test.

<Example 6>
The γ-FeOOH obtained in Example 5 was further dried and fired at about 260 ° C. to obtain γ-Fe ₂ O ₃ .
Water was further added to 10 g of γ-Fe ₂ O ₃ thus prepared, 0.5 g of conductive carbon powder, and ₃ g of an epoxy resin emulsion (H790, manufactured by Hitachi Chemical Co., Ltd.) as a binder. A total of 20 g was uniformly mixed to form a coating layer forming coating material.
Next, the same steel plate as in Example 1 was degreased and washed by the same method, and a coating layer was formed by the same method. The coated steel sheet 6 thus obtained is designated. The resulting coating layer had a thickness of about 20 μm.
The coated steel plate 6 thus produced was electrolyzed in the same manner as in Example 1. The difference from Example 1 is that the electrolytic solution used is an aqueous electrolyte containing 20 g / L of magnesium chloride, and that the electrolytic voltage is 2.5 V. All other conditions are the same as in Example 1. Electrolysis was done in the same way. Here, the contact electrical resistance value of the coating layer was 25 Ω / cm ² .
Magnesium ions were inserted into γ-Fe ₂ O ₃ by such a method.
Then, after washing with water and drying, polyester powder coating was further performed by an electrostatic powder coating method as a protective layer of this coating layer. And the total thickness of the coating layer containing γ-Fe ₂ O ₃ and this protective layer was 80 μm. The steel plate thus obtained is designated as test plate 6.
The contact electrical resistance value after forming this protective layer was 10 ⁸ Ω / cm ² or more.
The test plate 6 thus obtained was subjected to a corrosion resistance test.

<Example 7>
In the same manner as in Example 4, a coated steel sheet 7 having the same coating layer made of α-Fe ₂ O ₃ as in Example 4 was obtained.
The coated steel sheet 7 thus produced was electrolyzed in the same manner as in Example 1. The difference from Example 1 is that the electrolytic solution used is an aqueous electrolyte solution containing 20 g / L of calcium chloride, and that the electrolysis time is 10 minutes. All other conditions are the same as in Example 1. Was electrolyzed. Here, the contact electric resistance value of the coating layer was 3Ω / cm ² .
In this way, calcium ions were inserted into α-Fe ₂ O ₃ .
Then, after washing with water and drying, cationic electrodeposition was further applied as a protective layer of this coating layer, and the total thickness of the coating layer containing α-Fe ₂ O ₃ and this protective layer was 30 μm. The steel plate thus obtained is designated as test plate 7. The contact electrical resistance value after forming this protective layer was 10 ⁸ Ω / cm ² or more.
The test plate 7 thus obtained was subjected to a corrosion resistance test.

<Example 8>
SnO ₂ was prepared as an insertion material.
First, 25 g of first tin chloride was dissolved in 200 g of distilled water, transferred to an evaporating dish and dried, and baked at 450 ° C. for 2 hours while supplying air. The produced SnO ₂ was pulverized to prepare a SnO ₂ powder having a particle size of 3 μm or less.
10 g of SnO ₂ powder prepared in this way, 1 g of conductive carbon powder, 5 g of lithium silicate (concentration: 20% by mass) as a binder, and water added to make a total of 30 g uniform To form a coating layer forming coating material.
Next, this paint was applied to Example 1 and a steel plate in the same manner as in Example 1, and then dried at 160 ° C. to form a coating layer having a thickness of about 20 μm. The steel plate obtained here is referred to as a coated steel plate 8.
The coated steel plate 8 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 8. The difference from Example 1 is that the electrolytic solution used is an aqueous electrolytic solution containing 30 g / L of lithium chloride, the electrolytic voltage is 1.5 V, and the electrolysis time is 5 minutes. All the conditions were electrolyzed in the same manner as in Example 1. Here, the contact electrical resistance value of the coating layer was 10 Ω / cm ² .
The test plate 8 thus obtained was subjected to a corrosion resistance test.

<Example 9>
A coated steel sheet 1 was obtained in the same manner as in Example 1.
The coated steel plate 1 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 9. The difference from Example 1 is only that the aqueous electrolyte containing 10 g / L of lithium chloride and 10 g / L of magnesium chloride is used as the electrolyte, and the voltage is 2.5 V. Other conditions Are all the same as in Example 1.
Here, the contact electrical resistance value of the coating layer was 30 Ω / cm ² .
The test plate 9 thus obtained was subjected to a corrosion resistance test.

<Example 10>
As the insertion material, lithium titanate (Li ₄ Ti ₅ O ₁₂ ) particles (manufactured by Titanium Industry, LT-FP: average particle diameter of about 1 μm) were used.
And 90 g of this lithium titanate, 10 g of conductive carbon powder, 48 g of polyvinylidene chloride emulsion (Asahi Kasei Chemicals, Saran latex, solid content 20 mass%) as a binder, and styrene-isoprenesulfonic acid copolymer To 6 g of the polymer (solid content 40% by mass), water was further added to make a total of 200 g to obtain a coating composition for coating layer formation.
Next, the same steel plate as in Example 1 was degreased and washed by the same method, and a coating layer was formed by the same method. This is referred to as a coated steel plate 10. The resulting coating layer had a thickness of about 20 μm.
The coated steel plate 10 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 10. The only difference from Example 1 is that an aqueous electrolyte containing 30 g / L of lithium chloride was used as the electrolyte and that the voltage was 2.5 V. All other conditions were the same as in Example 1. It is. Here, the contact electric resistance value of the coating layer was 30 Ω / cm ² .
The test plate 10 thus obtained was subjected to a corrosion resistance test.

<Example 11>
A coated steel sheet 1 was obtained in the same manner as in Example 1.
The coated steel sheet 1 thus produced was electrolyzed in the same manner as in Example 1. The only difference from Example 1 is that an aqueous electrolyte containing 30 g / L of lithium chloride was used as the electrolyte and that the voltage was 2.5 V. All other conditions were the same as in Example 1. It is.
Here, the contact electrical resistance value of the coating layer was 30 Ω / cm ² .
Thereafter, it is washed with water and dried, and as a protective layer of this coating layer, water-based coating is further performed with a water-based paint to which a resin having a sulfo group that is an anionic group is added, and the total thickness of the coating layer and this protective layer is set. The thickness was 30 μm. The steel plate thus obtained is designated as test plate 11.
The contact electrical resistance value after forming this protective layer was 10 ⁸ Ω / cm ² or more.
The test plate 11 thus obtained was subjected to a corrosion resistance test.

<Example 12>
8 g of α-Fe ₂ O ₃ prepared in the same manner as in Example 3, 0.1 g of conductive carbon powder, and water-soluble phenol resin as a binder (concentration: 50% by mass, manufactured by Gunei Chemical Industry Co., Ltd.) To 4.0 g and 1.5 g of acrylic acid-sulfonic acid copolymer polymer (manufactured by Nippon Shokubai Co., Ltd., aquaric, solid content of 30% by mass), water was further added to make a total of 30 g. Thus, a coating layer forming paint was obtained.
Next, the same steel plate as in Example 1 was degreased and washed by the same method, and a coating layer was formed by the same method. This is referred to as a coated steel plate 12. The thickness of the obtained coating layer was about 10 μm.
The coated steel plate 12 thus produced was electrolyzed in the same manner as in Example 1 to obtain a test plate 12. The only difference from Example 1 is that an aqueous electrolyte containing 30 g / L of lithium chloride was used as the electrolyte and that the voltage was 2.5 V. All other conditions were the same as in Example 1. It is. Here, the contact electric resistance value of the coating layer was 30 Ω / cm ² .
The test plate 12 thus obtained was subjected to a corrosion resistance test.

<Example 13>
A coated steel plate 3 was obtained in the same manner as in Example 3.
The coated steel sheet 3 thus produced was electrolyzed in the same manner as in Example 1. The only difference from Example 1 is that an aqueous electrolyte containing 30 g / L of lithium chloride was used as the electrolyte and that the voltage was 2.5 V. All other conditions were the same as in Example 1. It is.
Here, the contact electrical resistance value of the coating layer was 30 Ω / cm ² .
Then, the protective layer of this coating layer was formed by the same method as Example 11. The total thickness of the coating layer and this protective layer was 30 μm. The steel plate thus obtained is used as a test plate 13.
The contact electrical resistance value after forming this protective layer was 10 ⁸ Ω / cm ² or more.
The test plate 13 thus obtained was subjected to a corrosion resistance test.

<Comparative Example 1>
A coated steel sheet 1 was obtained in the same manner as in Example 1.
This was not subjected to insertion of lithium ions, and was subjected to a corrosion resistance test. That is, the coated steel plate 1 is used as the test plate 14 in Comparative Example 1. The contact electrical resistance value of the coating layer was 30 Ω / cm ² .

<Comparative Example 2>
A coated steel plate 2 was obtained in the same manner as in Example 2.
This was not subjected to insertion of lithium ions, and was subjected to a corrosion resistance test. That is, the coated steel plate 2 is used as the test plate 15 in Comparative Example 2. The contact electrical resistance value of the coating layer was 60 Ω / cm ² .

<Comparative Example 3>
8 g of α-Fe ₂ O ₃ prepared in the same manner as in Example 3, 0.5 g of conductive carbon powder, and water-soluble phenol resin (concentration: 50% by mass, manufactured by Gunei Chemical Industry Co., Ltd.) as a binder To 4 g, water was further added to make a total of 20 g, which was uniformly mixed to obtain a coating layer forming coating material.
Next, the same steel plate as in Example 1 was degreased and washed by the same method, and a coating layer was formed by the same method. The steel plate thus obtained was designated as coated steel plate 16. The thickness of the obtained coating layer was about 10 μm.
This was not subjected to insertion of lithium ions, and was subjected to a corrosion resistance test. That is, the coated steel plate 16 is used as the test plate 16 in Comparative Example 3. The contact electrical resistance value of the coating layer was 15 Ω / cm ² .
The test plate 16 thus obtained was subjected to a corrosion resistance test.

<Comparative example 4>
A coated steel plate 5 was obtained in the same manner as in Example 5.
This was not subjected to the insertion of calcium ions, and was subjected to a corrosion resistance test. That is, the coated steel plate 5 is used as the test plate 17 in Comparative Example 4. The contact electric resistance value of the coating layer was ²⁰ Ω / cm ² .

  When the corrosion potentials in the neutral 5% NaCl aqueous solution were measured with a potentiostat for the test plates prepared in the examples and comparative examples, all of the comparative examples were almost iron corrosion potentials (−0. 44Vvs.SHE), a numerical value of -0.7 to -1.5Vvs.SHE, which is 0.2V or more lower than the corrosion potential of iron in all the test plates in the examples.

In addition, each of the test plates prepared in these examples and a standard hydrogen electrode were connected to a potentiostat and immersed in an aqueous NaCl solution (electrolyte). Then, the potential of the test plate was set to +0.5 V and held as it was for 20 minutes, and then elemental analysis in the electrolytic solution was performed.
As a result, lithium ions were detected in the electrolytic solutions of Examples 1 to 3 and Examples 8 to 13. Similarly, magnesium ions were detected in Examples 4, 6, and 9, and calcium ions were detected in Examples 5 and 7. Thus, the coating layers formed on each test plate (Example 6, Example 7, Example 11, and Example 13 were before the upper layer coating) passed through alkali metal ions or alkaline earth metal ions. It was confirmed that there is sex.

A corrosion resistance test was conducted by a combined cycle test (CCT) using a test plate in which a cross cut with a width of about 0.5 mm reaching the substrate with a cutter knife was inserted in the center of the test plate produced in the above-mentioned examples and comparative examples.
In this combined cycle test, after immersing in a 3% NaCl aqueous solution, put in a drier kept at 50 ° C. and hold for 1 hour, and further hold for 5 hours in a humid environment at 50 ° C. Judged by. The degree of rust was expressed as a percentage of the rust area relative to the observed area. Table 1 shows the test results.

  Among the examples and comparative examples, using the test plates prepared in Examples 1 and 3 and Examples 10 to 13 and Comparative Examples 1 and 3, the combined cycle test was further performed for 5 cycles for a total of 10 cycles. Table 2 shows the test results.

FIG. 1 is an explanatory diagram of a specific example of the production method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High corrosion-resistant metal material 11 Stainless steel plate 12 Coating layer 2 Graphite plate 3 Separator 5 Electrolytic solution 10 Electrolytic tank 15 Rectifier

Claims (28)

A metal material anti-corrosion method for preventing corrosion of a metal material,
Forming a coating layer on the surface of the metal material;
The coating layer contains an insertion material into which alkali metal ions and / or alkaline earth metal ions are inserted, and has electronic conductivity, and the alkali metal ions and / or the alkaline earth metal ions. Has the property of transmitting,
A method for preventing corrosion of a metal material, in which the alkali metal ions and / or the alkaline earth metal ions in the insertion material are released from the surface of the coating layer to prevent corrosion of the metal material.   The method for preventing corrosion of a metal material according to claim 1, wherein the potential of the surface of the metal material is 0.1 V or more lower than the corrosion potential of the metal material.   Furthermore, the corrosion prevention method of the metal material of Claim 1 or 2 including the process of carrying out the cathode polarization of the said metal material continuously or intermittently.   The method for preventing corrosion of a metal material according to any one of claims 1 to 3, wherein the alkali metal ion and / or alkaline earth metal ion is at least one selected from the group consisting of lithium ion, magnesium ion and calcium ion. A highly corrosion-resistant metal material having a coating layer on the surface of the metal material,
The coating layer contains an insertion material into which alkali metal ions and / or alkaline earth metal ions are inserted, and has electronic conductivity, and the alkali metal ions and / or the alkaline earth metal ions. A highly corrosion-resistant metal material that has the property of transmitting light.   The highly corrosion-resistant metal material according to claim 5, wherein the alkali metal ion and / or alkaline earth metal ion is at least one selected from the group consisting of lithium ion, magnesium ion and calcium ion.   The highly corrosion-resistant metal material according to claim 5 or 6, wherein a charge / discharge potential of the insertion material is -1.8 to -0.4 V with respect to a standard hydrogen electrode.   The insertion material includes at least one selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, a metal oxide, a metal carbide, a metal nitride, a carbon material, and an organic conductive material. The highly corrosion-resistant metal material according to any one of the above.   The highly corrosion-resistant metal material according to claim 8, wherein the alkali metal compound is at least one selected from the group consisting of lithium titanate, lithium ironate, lithium vanadate, lithium niobate, lithium manganate, and lithium zirconate. .   The alkaline earth metal compound is calcium titanate, calcium ferrate, calcium vanadate, calcium niobate, calcium manganate, calcium zirconate, magnesium titanate, magnesium ferrate, magnesium vanadate, magnesium niobate, manganic acid The highly corrosion-resistant metal material according to claim 8 or 9, which is at least one selected from the group consisting of magnesium and magnesium zirconate.   The metal oxide is at least one selected from the group consisting of titanium oxide, zirconium oxide, iron oxide, nickel oxide, cobalt oxide, manganese oxide, tin oxide, vanadium oxide, and niobium oxide. Highly corrosion-resistant metal material according to crab. The highly corrosion-resistant metal material according to claim 11, wherein the iron oxide is at least one selected from the group consisting of FeOOH, γ-Fe ₂ O ₃ and α-Fe ₂ O ₃ .   The highly corrosion-resistant metal material according to any one of claims 8 to 12, wherein the carbon material is at least one selected from the group consisting of graphite, activated carbon, nanocarbon, mesocarbon, coke, and carbon black.   The highly corrosion-resistant metal material according to any one of claims 8 to 13, wherein the organic conductive material is at least one selected from the group consisting of polyacene, polyacetylene, polythiophene, polyphenylene vinylene, polyaniline, and polypyrrole.   The highly corrosion-resistant metal material according to claim 5, wherein the coating layer contains an organic and / or inorganic binder.   The highly corrosion-resistant metal material according to claim 15, wherein the organic and / or inorganic binder has an anionic group. The anionic group is selected from the group consisting of a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and a peroxy group (—OOH). The high corrosion-resistant metal material according to claim 16, which is at least one selected from the group consisting of: The high corrosion-resistant metal material according to any one of claims 5 to 17, wherein the coating layer has a surface contact electrical resistance of 1 to 10 ¹⁰ Ω / cm ² under a relative humidity of 30 to 40%.   The highly corrosion-resistant metal material according to any one of claims 5 to 18, wherein at least one protective layer having a contact electrical resistance value higher than that of the coating layer is provided on a surface of the coating layer.   The high corrosion-resistant metal material according to claim 19, wherein the protective layer is formed using at least one selected from the group consisting of a powder coating material, an electrodeposition coating material, a solvent coating material, and a water-based coating material.   The high corrosion-resistant metal material according to claim 19 or 20, wherein the protective layer contains the organic and / or inorganic binder, and the organic and / or inorganic binder has an anionic group. The anionic group is selected from the group consisting of a hydroxyl group (—OH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phospho group (—PO ₃ H ₂ ), and a peroxy group (—OOH). The highly corrosion-resistant metal material according to claim 21, wherein the metal material is at least one selected from the group consisting of:   The high corrosion resistance metal material according to any one of claims 5 to 22, wherein the metal material is a steel material.   Building materials, bridge members, steel towers, gates, fences, handrails, vehicle / ship exterior materials, automobile steel plates, construction machinery, automobile undercarriage members, bicycles, concrete rebars, steel pipes, rails, road sign boards, signboards, guardrails, home appliances The highly corrosion-resistant metal material according to claim 5, which is used for product outer plates or boiler, gas or water pipes. A method for producing a highly corrosion-resistant metal material according to any one of claims 5 to 24,
A coating layer containing an insertion material into which the alkali metal ions and / or the alkaline earth metal ions can be inserted, and having a property of transmitting the alkali metal ions and / or the alkaline earth metal ions; Forming on the surface of the metal material;
Thereafter, the metal material on which the coating layer is formed is cathodically polarized in an electrolytic solution containing the alkali metal ion and / or the alkaline earth metal ion, and the alkali metal ion is incorporated into the insertion material. And / or a step of inserting the alkaline earth metal ion.   Furthermore, the manufacturing method of the highly corrosion-resistant metal material of Claim 25 which comprises the process of removing the said electrolyte solution after the said cathode polarization. A method for producing a highly corrosion-resistant metal material according to any one of claims 5 to 24,
A highly corrosion-resistant metal material for forming the coating layer by coating the surface of the metal material with a composition containing the insertion material into which the alkali metal ions and / or the alkaline earth metal ions are inserted. Production method.   Furthermore, the manufacturing method of the highly corrosion-resistant metal material in any one of Claims 25-27 which comprises the process of forming at least 1 layer of protective layers whose contact electrical resistance value is higher than the said coating layer on the surface of the said coating layer. .

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