JP4840966B2 - Conductive polymer coated metal material - Google Patents

Description

  The present invention relates to a coated metal material in which a conductive polymer film that functions as an anticorrosive film and a conductive film is formed on a metal substrate, and particularly in an environment where the metal is easily corroded, such as in an acidic atmosphere or in a halide solution. Thus, the present invention relates to a coated metal material that exhibits excellent corrosion resistance and conductivity over a long period of time.

Corrosion prevention methods for metal materials include coating the surface with organic or inorganic materials, adding a corrosion inhibitor such as thioacetamide to the bath solution in an environment where the metal is prone to corrosion, and electrochemically corroding the corrosion current. The anti-corrosion method to suppress is known.
In recent years, there has been a demand for materials that combine corrosion resistance and conductivity for structural materials for organic synthesis plants that have antistatic properties, electrode materials used for organic electrolytic synthesis, and power supply terminal applications such as terminals and crimp terminals. It has been. As materials having both corrosion resistance and conductivity, corrosion-resistant alloys such as Hastelloy alloys and noble metal alloys and amorphous carbon materials are known. However, the corrosion-resistant alloys are very expensive, and the amorphous carbon materials are processed. However, there is a disadvantage that it is complicated and inferior in productivity.

  On the other hand, surface-coated metal materials typified by materials obtained by plating a noble metal on an inexpensive metal base such as stainless steel or materials chromated are known. These coated metal materials can be manufactured with high productivity because the base metal itself is relatively inexpensive and excellent in workability. However, there is a problem that a local battery reaction occurs due to pinholes and cracks in the coating film, resulting in lack of long-term reliability. In addition, noble metal plating baths and chromate treatment solutions contain harmful cyanide compounds and hexavalent chromium ions, resulting in high environmental impact.

  In order to solve these problems, Patent Document 1 discloses that two Ni plating layers having different oxidation-reduction potentials are provided on a metal substrate so that the upper layer becomes a more basic Ni layer, and further, Au plating is used as the uppermost layer. A method for preventing pitting corrosion due to pinholes and improving the corrosion resistance of a metal material by forming them is disclosed. Patent Document 2 discloses a technique for reducing environmental burden by performing chemical conversion treatment using a trivalent chromium compound and a compound such as titanium as a hexavalent chromium alternative technique.

  However, in the method of Patent Document 1, in order to protect the metal substrate at the self-sacrifice of the base Ni plating layer by the gold plating layer and the Ni plating layer having a high oxidation reduction potential, the Ni plating layer having a low oxidation reduction potential is Corrosion continues to progress. Since the effect disappears due to the disappearance of the Ni plating layer, the long-term reliability is insufficient. In addition, in the method of Patent Document 2, an inorganic polymer formed from trivalent chromium has a small molecular weight and is inferior in thermal stability as compared to a very stable inorganic polymer formed from hexavalent chromium. Therefore, a second component such as titanium is added, but they are more likely to change from an inorganic polymer to a thermally stable oxide form compared to a chromium inorganic polymer, at which time cracks and the like occur. Therefore, there is a problem that the effect of protecting the substrate from the corrosive environment is lowered.

JP 2001-234361 A JP 2000-234177 A

  An object of the present invention is a method in which a coating that exhibits good conductivity and anticorrosion ability is used on an inexpensive and highly productive metal substrate without using expensive or high environmental impact materials in view of the above problems. Even when used in an environment where the metal is easily corroded, such as in an acidic atmosphere or in a halide solution, while maintaining good electrical conductivity for a long period of time It is an object of the present invention to provide a coated metal material that is excellent in corrosion resistance stability, in which dissolution of metal base material and rust generation are suppressed.

  As a result of intensive investigations on a coated metal material in which a conductive polymer film is formed on a metal substrate as a film that exhibits conductivity and anticorrosion performance, the present inventors have found that a conductive polymer formed on a metal surface. By including a specific dopant compound in the coating film, the formation of an insulating metal oxide on the surface of the metal substrate can be suppressed, the good electrical conductivity of the metal substrate can be maintained, and the durability of the coated metal material can be maintained. As a result, the present invention has been completed.

That is, the present invention is a coated metal material described in (1) to (5) below.
(1) In a coated metal material in which a conductive polymer coating film containing at least a dopant compound is formed on the surface of a substrate made of a metal material, the dopant compound contained in the conductive polymer coating film is at least 1 A coated metal material comprising a compound having one or more sulfonic acid groups and a molecular weight of 240 or more.

  (2) The dopant compound contained in the conductive polymer coating film of the coated metal material is a compound having a benzene condensed ring and / or at least two or more aromatic rings. Coated metal material.

  (3) In (1) or (2), the dopant compound contained in the conductive polymer coating film of the coating metal material is a compound exhibiting oxidation-reduction activity that is electrochemically reversible. The coated metal material as described.

  (4) The coated metal material according to (3), wherein the dopant compound contained in the conductive polymer coating film of the coated metal material is a compound having a quinone structure.

  (5) The coated metal according to any one of (1) to (4), wherein the conductive polymer coated film of the coated metal material includes at least one formed by an electrolytic polymerization method. material.

  By making the dopant compound contained in the conductive polymer coating film of the coating metal material the specific compound, the conductive coating film effectively works as a barrier film for protecting the substrate from corrosive liquid. In addition, by using a compound exhibiting redox activity that is electrochemically reversible as the dopant compound, the electrode potential of the coated metal material can be controlled in accordance with the environment, and the metal anticorrosive effect is dramatically improved. To do. In addition, since corrosion of the base can be prevented while suppressing the growth of the oxide film on the metal base even in a corrosive environment, the good electrical conductivity of the metal material can be maintained over a long period of time.

  The present invention relates to a coated metal material in which a conductive polymer coating film containing at least a dopant compound is formed on the surface of a substrate made of a metal material, wherein the dopant compound is contained in at least one sulfone. It is a coated metal material characterized by being a compound having an acid group and a molecular weight of 240 or more. The environment in which the coated metal material of the present invention is used and the metal is easily corroded is not only in an acidic atmosphere such as in an aqueous hydrochloric acid solution or an aqueous sulfuric acid solution, but also in an oxidizing atmosphere solution such as an aqueous sodium hypochlorite solution. Is also envisaged. Under such circumstances, dopant ions having a carboxylic acid group such as benzoate ions and oxalate ions, which are conventionally known as dopants to be present in the conductive polymer coating film, are easily oxidized and carbon dioxide. Therefore, the electrical conductivity of the conductive polymer is lost. In addition, other anions having a hydroxy group are not suitable because they have low acceptor properties, have a low ability to create holes in conductive polymers, and are difficult to exhibit electrical conductivity. Therefore, it is preferable to use a dopant anion having a sulfonic acid group that can express high electrical conductivity and has strong oxidation resistance. The number of sulfonic acid groups in the compound is not particularly limited.

  In addition, when the molecular weight of the dopant compound is less than 240, the molecular weight is small, that is, the molecule is small, so that the dedoping easily occurs in the solution and also easily occurs in the atmosphere. Since the electrical conductivity is lost, the molecular weight is preferably 240 or more. Specific examples of the dopant compound having one or more sulfonic acid groups and having a molecular weight of 240 or more include anionic components such as sodium ferrocenesulfonate and sodium ligninsulfonate. A conductive polymer coating film containing such a dopant is suitable because it has a large barrier effect for blocking the corrosive environment from the substrate.

  A dopant having a benzene fused ring and / or two or more aromatic rings can be intricately intertwined with the polymer chain of the conductive polymer, creating a denser structure and further increasing the barrier effect. Moreover, it is suitable because it has the effect of making it difficult to dope by complicatedly intertwining.

  Examples of such dopants include anthracene sulfonic acid, diphenylamine sulfonic acid, an anion component of alkali metal salt or ammonium salt of diphenylamine sulfonic acid, acid black 1, acid blue 1, acid blue 3, acid blue 9, acid blue which is a dye. 20, Acid Blue 74, Acid Blue 83, Acid Blue 92, Acid Blue 119, Acid Blue 147, Acid A, Acid Brilliant Green J, Acid Brown M, Acid Captor H, Acid Captor 9M, Acid Cyanine 6B, Acid First Yellow G , Acid Faxin, Acid Green 1, Acid Green 3, Acid Green 5, Acid Green 9, Acid Green 16, Acid Glee 50, Acid Green B, Acid Green GG, Acid Light Yellow 2G, Acid Orange 5, Acid Orange 6, Acid Orange 7, Acid Orange 17, Acid Orange 20, Acid Red, Acid Red 1, Acid Red 2, Acid Red 9, Acid Red 13, Acid Red 18, Acid Red 18, Acid Red 26, Acid Red 27, Acid Red 29, Acid Red 52, Acid Red 60, Acid Red 87, Acid Red 88, Acid Red 91, Acid Red 92, Acid Red 94, Acid Red 112, Acid Red 265, Acid Bio Red 6B, Acid Bio Red 34, Acid Bio Red 43, Acid Bio Red 49, Acid Yellow 3, Acid Yellow 23, Acid Red 36, Acid Yellow 73, Acid Yellow 186, Sulfonazo III, Moldant 29, Sun Chromaine Blue Black R, Sun Chromaine Blue Black MB, Sun Chromaine Blue Black MD, Sunset Yellow FCF, Alpha Mine Anionic components such as Red R, Alpha Mine Red R base, Arsenazo I, Arsenazo III and their derivatives.

  The conductive polymer film containing a dopant compound having at least one sulfonic acid group and exhibiting electrochemically reversible oxidation-reduction activity should have a barrier property between the corrosive liquid and the substrate. In addition to having the function of being able to function, when exposed to a corrosive environment, the dopant performs an oxidation-reduction reaction in accordance with the environment, and the electrode potential of the conductive polymer-coated metal material is electrochemically changed. Therefore, the anticorrosion effect of the substrate is particularly remarkable.

  The aforementioned electrochemically reversible compound exhibiting redox activity is a compound capable of exhibiting an electrochemically reversible redox reaction, that is, oxidized at the anode and reduced to the original state at the cathode. Refers to a compound that can. For example, naphthoquinonesulfonic acid is oxidized at the anode and the quinone structure site becomes a hydroxy group, but at the cathode, the hydroxy group site is reduced to return to the quinone structure. This reaction can be confirmed by the cyclic voltammetry method, and the reaction peak during the oxidation reaction and the reaction peak during the reduction reaction appear at substantially the same potential.

  Specific examples of compounds containing at least one sulfonic acid group having electrochemically reversible redox activity include ferrocene sulfonic acid, hydroquinone sulfonic acid, anthoquinone sulfonic acid, naphthoquinone sulfonic acid, and azaxanthone sulfone. Anion component of alkali metal salt or ammonium salt such as acid, benzanthraquinone sulfonic acid, benzanthrone sulfonic acid, phenylazobenzene sulfonic acid, benzoquinone sulfonic acid and their derivatives, anthraquinone Irin R, anthraquinone Bio Red RN-3RN Ferrocene sulfonic acid, anthraquinone sulfonic acid, naphthoquinone sulfonic acid, azaxanthone sulfonic acid, benzanthraquinone due to resistance to oxidation and undoping It is more preferable to use an anion component of an alkali metal salt or ammonium salt of sulfonic acid, benzanthrone sulfonic acid, phenylazobenzene sulfonic acid or a derivative thereof, an anthraquinone Irin R which is a pigment, or an anion component of anthraquinone Biored RN-3RN.

  Among them, a dopant having a quinone structure and a sulfonic acid group has high electrochemical activity and a high redox potential. Therefore, the redox potential of the conductive polymer film containing the dopant is shifted to the most noble and the effect of protecting the substrate can be maximized. Therefore, it is most preferable to use the dopant. Specific examples of such a dopant include anthraquinone sulfonic acid and naphthoquinone sulfonic acid.

  The dopant may be contained alone in the coating film, or may be contained so as to exist in plural.

  Examples of the conductive polymer monomer formed on the metal surface include pyrrole, thiophene, alkylthiophene, alkylenedioxythiophene, aniline, phenylene, acetylene, furan, phenylene vinylene, acene, azulene and derivatives thereof, or these. Examples of those that give a π-conjugated conductive polymer when polymerized, such as a combination of two or more, are pyrrole, alkylthiophene, alkylenedioxythiophene, aniline, and those excellent in corrosion resistance and electrical conductivity. Derivatives are preferably used.

  There are mainly chemical polymerization methods and electrolytic polymerization methods as methods for synthesizing conductive polymers, but it is necessary to select an appropriate method depending on the type and form of the target conductive polymer.

  A conductive polymer film can be formed on the surface of the substrate by an electrolytic polymerization method in which the substrate is used as an electrode in an electrolytic solution containing a monomer and a supporting electrolyte. For example, when a polypyrrole film is formed, a monomer pyrrole and a supporting electrolyte such as sodium ferrocene sulfonate or potassium naphthoquinone sulfonate are dissolved in a solution and electrolyzed using the substrate as an anode. A dense polypyrrole film having high electrical conductivity can be obtained by containing the anion of the supporting electrolyte as a dopant on the substrate.

  By the way, when electropolymerization is performed using a metal substrate as an anode, the formation of a high-resistance oxide film layer occurs as a side reaction in the initial stage of electrolysis, and the resistance at the conductive polymer / metal interface increases. As a result, the volume resistivity may greatly increase, and the good electrical conductivity of the metal material may be lost. As a result, the conductive polymer may grow in an island shape and may not be electropolymerized to a uniform thickness. Usually, a natural oxide film layer is formed on the metal surface. Therefore, when using the electrolytic polymerization method, the conductive polymer layer is formed while suppressing the formation of the oxide film layer after removing the natural oxide film. Preferably it is done.

  When the above-mentioned compound showing electrochemically reversible redox activity is used as the supporting electrolyte, the conductive polymer layer can be formed by electrolytic polymerization while suppressing the formation of the oxide film layer. Since the dopant composed of the anionic component of the supporting electrolyte has redox activity, it can repeat a redox cycle on the electrode surface during the electropolymerization, so that the oxidation reaction of the dopant also occurs at the anode, The side-reaction metal oxide film formation reaction is reduced. Further, since it also acts as a reducing agent before the oxidation reaction occurs, it also has the effect of suppressing the formation of an oxide film on the substrate surface in the vicinity of the substrate electrode. Due to the effects described above, it becomes possible to coat the metal surface with the insulating metal oxide film that occurs in the early stage of the electropolymerization, before the metal surface is coated, and the good electrical conductivity of the metal is maintained. Will be.

  In the electropolymerization, when a compound having no redox activity is used as the supporting electrolyte, it can be used as an acid type instead of a salt type. If the supporting electrolyte is used for electrolytic polymerization in a neutral region, an oxide film may be formed in the initial stage. However, by making the supporting electrolyte acidic, the electrolytic polymerization solution becomes acidic, and at the initial stage of the electrolytic polymerization, the etching reaction of the substrate that is the anode proceeds, and the formation of an oxide film is suppressed, and the interface having good electrical conductivity. And a conductive polymer film having high corrosion resistance can be coated. As a method for converting from a salt type to an acid type, conventionally known methods can be used. For example, an ion exchange resin method, a reverse osmosis membrane method, or the like can be used. When it is difficult to change from the salt type to the acid type, a part of the acid type supporting electrolyte exchangeable to the acid type may be used. In addition, the supporting electrolyte having redox activity can be used by exchanging it with an acid type.

  In the chemical polymerization method, a conductive polymer film can be formed on the surface of the substrate by bringing the monomer of the desired conductive polymer into contact with the oxidizing agent solution on the surface of the substrate. For example, when a poly-3,4-ethylenedioxythiophene film is formed, 3,4-ethylenedioxythiophene as a monomer and ferrocenesulfonic acid ion as a dopant on the surface after removal of the base oxide film A poly-3,4-ethylenedioxythiophene coating can be obtained by spraying an aqueous solution of iron (III) chloride as an oxidizing agent solution after applying an ethanol-water mixed solution containing naphthoquinone sulfonate ions.

  In addition, when the polymer obtained by chemical polymerization or electrolytic polymerization is soluble, the polymer is dried and then dissolved in an appropriate organic solvent such as toluene or methylene chloride to form a coating solution, which is then applied to the upper layer of the metal substrate. A solution method of forming a conductive polymer film by drying can be used. For example, when forming a film of poly-3-hexylthiophene, 3-hexylthiophene, ammonium peroxodisulfate as an oxidizing agent, sodium 2,7-ferrocenesulfonate as a dopant is dissolved in an ethanol-water mixed solution, The polymerization reaction proceeds while stirring, and the resulting poly-3-hexylthiophene is dried and dissolved in toluene to obtain a coating solution. The coating solution is applied onto the substrate surface and then dried to obtain poly-3-hexyl. A thiophene film can be obtained.

  As a method for applying the soluble conductive polymer solution, a conventionally known method can be used. For example, screen printing method, dip coating method, roll coating method, spraying method, curtain flow coating method, bar coating method, doctor blade method, brush coating method, etc., there are simple and highly productive dip coating method, brush coating The method is preferred.

  By the way, the conductive polymer film obtained by the chemical polymerization method may be inferior in electrical properties because the molecular weight is small and the regularity of the structure is low as compared with the conductive polymer film obtained by the electrolytic polymerization method. In that case, after forming a conductive polymer coating film obtained by a chemical polymerization method, it is preferable to form a conductive polymer film by an electrolytic polymerization method using the coating film as an electrode. As a result, a conductive polymer film having a dense and highly regular electric conductivity is formed on the uppermost layer, and a coating film having excellent corrosion resistance and good conductivity is formed on the upper layer of the substrate.

  Examples of the metal substrate include stainless steel, iron, aluminum, magnesium, titanium, nickel, cobalt, copper, zinc, tin, and alloys thereof. From the viewpoint of productivity and corrosion resistance, stainless steel, nickel, titanium, cobalt, Copper and their alloys are preferably used.

  As a method for removing the natural oxide film layer of the metal base material, conventionally known methods can be used, for example, a wet etching method, an electrolytic etching method, an electrolytic polishing method, a mechanical polishing method, a reverse sputtering method, a blast method, a substitution method. There are plating methods, but cheap wet etching and mechanical polishing methods are preferred.

  Regarding the formation of a conductive polymer film, if it is desired to form a conductive polymer film on a substrate having a complicated shape, the substrate is previously subjected to electrical conductivity after mechanical processing such as bending, cutting, etching, etc. A polymer forming step may be performed. For example, by performing electropolymerization using the processed substrate as an electrode as described above, it is possible to form a conductive polymer film uniformly even if the substrate surface is uneven due to processing, and stable performance is achieved. Obtainable.

  The thickness of the conductive polymer to be formed is suitably from 0.001 μm to 100 μm, but from an economic point of view, 0.001 μm to 50 μm is more preferable, and 0.001 μm to 30 μm is most preferable. When it is 0.001 μm or less, it is difficult to obtain the effect of the coating film of the present invention.

  Hereinafter, an example of a method for producing a coated metal material according to the present invention will be described by taking a case of producing a thin plate electrode as an example. First, a base made of a plate-like metal material is prepared. In order to reduce the interface resistance between the conductive polymer and the substrate, the natural oxide film on the surface of the substrate is removed. By this operation, the interface resistance can be reduced, the volume resistivity of the electrode can be reduced, and the adhesion to the substrate can be improved.

  Next, a conductive polymer coating film is formed on the substrate by an electrolytic polymerization method. For example, in the case of forming a polypyrrole film, the electrolytic polymerization method is performed by dissolving pyrrole as a monomer and a supporting electrolyte in an appropriate solvent, and performing electrolysis using the substrate as an anode to form a metal surface on the substrate. A conductive polymer film containing the anionic component of the supporting electrolyte as a dopant is obtained. A thin plate electrode is manufactured by the above process. As described above, before the electropolymerization, a conductive polymer film is previously formed on the substrate surface by a chemical polymerization method or a solution method, and an electrolytic polymerization coating film is formed on the chemical polymerization conductive polymer film. May be.

  As described above, according to the present invention, it is possible to provide a coated metal material excellent in conductivity and corrosion resistance by forming a conductive polymer film using an inexpensive and highly productive metal substrate. . In particular, when a conductive polymer film such as polypyrrole or polyaniline is formed on the uppermost layer by electrolytic polymerization, the effect can be exhibited most.

  In addition, the coated metal material produced according to the present invention is not only an ordinary corrosion-resistant material such as a structural material, but also an antistatic material, an anode for electrolysis, a catalyst electrode, a power supply terminal, a current collector plate, etc. It can be used for applications requiring electrical conductivity.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited at all by the Example.

Example 1
SUS304 was used as the metal substrate. SUS304 is a rolled material having a size of 20 × 30 mm and a thickness of 0.2 mm. In order to remove the natural oxide film of the substrate, the substrate was immersed in a 10% by weight oxalic acid aqueous solution for 10 minutes, washed with ethanol, and sufficiently dried with nitrogen gas.

  K., a known document. Ferrocene sulfonic acid was prepared by the method described in Yamamoto, POLYMERS FOR ADVANCED TECHNOLOGIES, 11, 710-715, (2000). 60 g ferrocene was added to 400 mL dioxane. While stirring it in an ice bath, 120 ml of dioxane containing sulfuric acid (31 g) was slowly added dropwise and left stirring for 12 hours. The solution was distilled, and 500 mL of water was added to the resulting slurry material and filtered to remove unreacted substances. The obtained filtrate was distilled to further remove impurities to obtain a ferrocenesulfonic acid solution. This was recrystallized in a water-methanol mixed solution to obtain yellow ferrocenesulfonic acid crystals. (Yield 9.8%)

Next, a conductive polymer film was formed by electrolytic polymerization. Using pure water as a solvent, 0.45 mol / L of pyrrole as a monomer, 0.20 mol / L of ferrocenesulfonic acid as a supporting electrolyte, and an electrolyte adjusted to pH 6.5 with aqueous NaOH, The cathode was subjected to electropolymerization with an electropolymerization time of 1 hour and a current density of 5 mA / cm ² to form a polypyrrole film, thereby preparing 10 thin plates.

(Example 2)
SUS304 was used as the metal substrate. SUS304 is a cold rolled material having a size of 20 × 30 mm and a thickness of 0.2 mm. In order to remove the natural oxide film of the substrate, the substrate was immersed in a 5 wt% hydrofluoric acid aqueous solution for 5 minutes, washed with ethanol, and sufficiently dried with nitrogen gas.

  Next, a conductive polymer film was formed by a solution method. In an ethanol-water mixed solvent whose pH is adjusted to 7, 0.4 mol / L of 3-hexylthiophene and 0.20 mol / L of iron (III) anthracenesulfonate acting as an oxidizing agent and a dopant are added to an ice bath temperature. Stir for 6 hours under. After filtering the solution, the obtained powder was dried under reduced pressure to completely remove the solvent, and the powder was dissolved in toluene to obtain a coating solution.

  After uniformly applying the solution to the substrate from which the oxide film has been removed by spraying, the process of removing toluene in a dryer at 70 ° C. is repeated to form a poly-3-hexylthiophene film having a thickness of 15 μm. A sheet was produced.

(Example 3)
SUS304 was used as the metal substrate. SUS304 is a cold rolled material having a size of 20 × 30 mm and a thickness of 0.2 mm. In order to remove the natural oxide film of the substrate, the substrate was immersed in a 5 wt% hydrofluoric acid aqueous solution for 5 minutes, washed with ethanol, and sufficiently dried with nitrogen gas.

  Next, a conductive polymer film was formed by a solution method. In an ethanol-water mixed solvent whose pH is adjusted to 7, 3-octylthiophene 0.4 mol / L, iron (III) chloride 0.20 mol / L as an oxidizing agent, and acid black 0.2 mol / L as a dopant are iced. Stir for 6 hours under bath temperature. After filtering the solution, the obtained powder was dried under reduced pressure to completely remove the solvent, and the powder was dissolved in a toluene solution to obtain a coating solution.

  After uniformly applying the solution to the substrate from which the oxide film had been removed by a spraying method, toluene was removed in a dryer at 70 ° C. to form a poly-3-octylthiophene film having a thickness of 0.1 μm.

Subsequently, a conductive polymer film is formed by electrolytic polymerization using the previously formed poly-3-octylthiophene film as an electrode. Using an electrolytic solution containing pure water as a solvent, pyrrole 0.45 mol / L as a monomer, and acid black 0.20 mol / L as a supporting electrolyte, a 3-octylthiophene film as an anode, Ni as a cathode, electropolymerization time Was subjected to electrolytic polymerization for 1 hour at a current density of 5 mA / cm ² to form a polypyrrole film, and 10 thin plates were produced.

Example 4
SUS316L was used as the metal substrate. SUS316L is a rolled material having a size of 20 × 30 mm and a thickness of 0.2 mm. In order to remove the natural oxide film of the substrate, the substrate was immersed in a 10% by weight oxalic acid aqueous solution for 60 minutes, washed with ethanol, and sufficiently dried with nitrogen gas.

Next, a conductive polymer film was formed by electrolytic polymerization. Using a pure water as a solvent, an electrolytic solution containing 0.45 mol / L of o-toluidine as a monomer and 0.20 mol / L of 1,4-naphthoquinone-2-sulfonic acid as a supporting electrolyte, the substrate is made into an anode, Pt The cathode was subjected to electropolymerization with an electropolymerization time of 1 hour and a current density of 5 mA / cm ² to form a poly-o-toluidine film, and 10 thin plates were produced.

(Example 5)
Ti was used as the metal substrate. Ti is a cold-rolled material having a size of 20 × 30 mm and a thickness of 0.1 mm. After degreasing by ultrasonic cleaning in acetone, it was cleaned with ethanol and sufficiently dried with nitrogen gas.

  Acid Red 112 aqueous solution (1.0 mol / L) was passed through a cation exchange column to obtain Na type acid type acid 112 aqueous solution.

Next, a conductive polymer film was formed by electrolytic polymerization. The solvent is pure water, an electrolyte containing 0.45 mol / L of pyrrole as a monomer and Acid Red 112 (0.20 mol / L) as a supporting electrolyte, the base is an anode, Pt is a cathode, and the electropolymerization time is Electropolymerization was performed at a current density of 5 mA / cm ² for 1 hour to form a polypyrrole film, and 10 thin plates were produced.

(Example 6)
An Al alloy was used as the metal substrate. The Al alloy is a cold rolled material having a size of 20 × 30 mm and a thickness of 0.6 mm. In order to remove the natural oxide film of the substrate, the substrate was immersed in a 10% by weight hydrochloric acid aqueous solution for 60 minutes, washed with ethanol, and sufficiently dried with nitrogen gas.

  1,2-Naphthoquinone-4-sulfonic acid potassium aqueous solution (1.0 mol / L) was passed through a cation exchange column to obtain K-type to H-type 1,2-naphthoquinone-4-sulfonic acid aqueous solution.

  Next, a conductive polymer film was formed by electrolytic polymerization. The solvent is pure water, an electrolyte containing 0.30 mol / L of aniline as a monomer, and 0.60 mol / L of 1,2-naphthoquinone-4-sulfonic acid as a supporting electrolyte, the base is an anode, and SUS304 is a cathode. , Silver / silver chloride (saturated KCl) as reference electrode, electrode electropolymerization time is 1 hour, electrolysis voltage is set to 0.4 V (vs silver / silver chloride reference electrode), and a polyaniline film is formed, Ten thin plates were produced.

(Example 7)
SUS304 was used as the metal substrate. SUS304 is a cold rolled material having a size of 20 × 30 mm and a thickness of 0.2 mm. In order to remove the natural oxide film of the substrate, the substrate was immersed in a 10 wt% hydrofluoric acid aqueous solution for 5 minutes, washed with ethanol, and sufficiently dried with nitrogen gas.

  Sprayed with an aqueous solution of iron (III) 2-anthraquinone sulfonate, which is an oxidant solution containing 3,4-ethylenedioxythiophene as a monomer and a dopant, on the surface of the substrate after the removal of the substrate oxide film at 50 ° C. The process of drying for 10 minutes was repeated to form a poly-3,4-ethylenedioxythiophene film having a thickness of 26 μm, and 10 thin plates were produced.

(Comparative Example 1)
Except that the supporting electrolyte was p-toluenesulfonic acid in Example 1, it carried out similarly and produced 10 sheets.

(Comparative Example 2)
Ten thin plates were produced in the same manner except that the dopant in Example 2 was iron (III) chloride.

(Comparative Example 3)
Ten thin plates were produced in the same manner except that the supporting electrolyte in Example 3 was sodium oxalate.

(Comparative Example 4)
Ten thin plates were produced in the same manner except that the supporting electrolyte in Example 4 was perchloric acid.

(Comparative Example 5)
Ten thin plates were produced in the same manner except that the supporting electrolyte in Example 5 was benzoic acid.

(Comparative Example 6)
Ten thin plates were produced in the same manner except that the supporting electrolyte in Example 6 was potassium formate.

(Comparative Example 7)
Ten thin plates were produced in the same manner except that the oxidizing agent solution containing the dopant in Example 7 was iron (III) p-toluenesulfonate.

(Comparative Example 8)
In accordance with Japanese Patent Laid-Open No. 2001-234361, a SUS304 plate (20 × 30 mm, thickness 0.2 mm) was used as the metal substrate. The substrate was degreased with an alkaline degreasing solution, subsequently pickled with 10% by weight oxalic acid, and then used as a plating substrate. First, using a Watt bath containing a large amount of nickel chloride having a nickel sulfate hexahydrate of 1.00 mol / L, nickel chloride hexahydrate of 0.25 mol / L, and boric acid of 0.65 mol / L, a current density of 100 mA / A first Ni plating layer having a low sulfur content was formed at cm ² and a bath temperature of 50 ° C. Subsequently, nickel sulfate hexahydrate 1.2 mol / L, nickel chloride hexahydrate 0.19 mol / L, boric acid 0.65 mol / L, sodium 1,5-naphthalene disulfonate 2.33 × 10 ⁻² A second Ni plating layer was formed at a current density of 100 mA / cm ² and a bath temperature of 50 ° C. using a Watt bath having mol / L and thiourea of 1.31 × 10 ⁻³ mol / L. Next, using a commercially available cyan gold plating bath, a gold plating layer was formed at a current density of 100 mA / cm ² and a bath temperature of 30 ° C. to produce 10 thin plates.

(Comparative Example 9)
In accordance with Japanese Patent Laid-Open No. 2000-234177, carbon steel (20 × 30 mm, thickness 0.2 mm) was electrogalvanized (8 μm) using a commercially available acidic zinc plating solution, washed with water, and then 67. The activation treatment was performed by immersing in an acid solution containing 5% concentrated nitric acid 2 ml / L for 5 seconds at room temperature. Then, after water washing, it was immersed in a chemical conversion treatment solution at 40 ° C. for 60 seconds to perform chemical conversion treatment. As the chemical conversion liquid composition, chromium nitrate nonahydrate: 45 g / L, 62.5% sulfuric acid: 10 g / L, and titanium sulfate 5 g / L (solvent is pure water) were used. During the treatment, the chemical conversion solution was stirred by air stirring. Then, it washed with water and dried for 15 minutes with a 70 degreeC warm air, and produced 10 sheets.

(Evaluation of coated metal materials)
Table 1 shows the results obtained by conducting a salt spray test (according to JIS-Z2371) for 90 days on the coated metal material according to the present invention and the material of the comparative example thus produced, and comparing the corrosion resistance performance by the appearance inspection method. Shown in Table 2 shows the results of comparing the volume resistivity of the test piece after the salt spray test by the four-terminal measurement method in order to investigate the conductive characteristics.

  According to the results of Table 1, it was recognized that each material of Examples 1 to 7 according to the present invention has excellent corrosion resistance without any change even after 2160 hours of the salt spray test. On the other hand, in the materials produced in Comparative Examples 1 to 9 which were similarly subjected to the salt spray test, peeling of the conductive polymer film and the plating layer was confirmed due to corrosion of the substrate.

According to the results in Table 2, it was confirmed that each of the materials of Examples 1 to 7 according to the present invention retained good volume resistance even after 2160 hours of the salt spray test and had excellent conductive properties. On the other hand, the materials produced in Comparative Examples 1 to 7 and 9 in which the salt spray test was performed in the same manner, the corrosion of the substrate progressed considerably, and the volume resistivity was 1.000 × 10 ¹⁰ or more. It was not possible to measure accurately, and the conductive properties were lost. In the material produced in Comparative Example 8, it was recognized that the volume resistivity was increased by peeling of the gold plating layer, and the current collection characteristics were inferior.

Claims (3)

In the anticorrosive conductive film- coated metal material in which a conductive polymer coating film containing at least a dopant compound is formed on the surface of a substrate made of a metal material, the dopant compound contained in the conductive polymer coating film is at least 1 A compound having one or more sulfonic acid groups, a molecular weight of 240 or more , a benzene condensed ring and / or at least two aromatic rings, and having electrochemically reversible redox activity A metal material coated with an anticorrosive conductive film , characterized in that it exists. It said dopant compound contained in the conductive polymer coating film of anticorrosion conductive film coated metal material, anticorrosive conductive film coated metal material of claim 1 wherein which is a compound having a quinone structure. 3. The anticorrosive conductive film according to claim 1, wherein the conductive polymer coating film of the metal film coated with the anticorrosive conductive film includes at least one formed by an electrolytic polymerization method. Coated metal material.