JPWO2018216319A1 - Manufacturing method of titanium plated member - Google Patents

Abstract

The method for producing a titanium-plated member includes a step of preparing a base material having a conductive surface, and forming the base material into at least one Group 1 metal ion of Li + and Na +, F −, and Tin + Step of immersing in the molten salt titanium plating solution composition containing, and energized so that the substrate immersed in the molten salt titanium plating solution composition becomes a cathode, by coating the surface of the substrate with titanium, Forming a titanium plating film on the surface; and cleaning the titanium plating film with at least one compound selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides and KF. A step of removing first deposits adhered to the surface of the titanium plating film in the step of forming the titanium plating film by contacting and washing with a salt; And a step of removing the second material adhering to the surface of the titanium plated film in the step of washing with molten salt, a.

Description

  The present disclosure relates to a method for manufacturing a titanium plated member. This disclosure claims the priority based on Japanese Patent Application No. 2017-100758 filed on May 22, 2017. The entire contents described in the Japanese patent application are incorporated herein by reference.

As a method for performing titanium plating, a plating method in a molten salt has been studied. For example, in Japanese Patent Application Laid-Open No. 2015-193899 (Patent Document 1), an alloy film of Fe and Ti is formed on the surface of an Fe wire using a plating bath obtained by adding K ₂ TiF ₆ and TiO ₂ to KF-KCl. It is described that it did. Non-Patent Document 1 describes a method for forming a titanium film on a Ni and Fe substrate surface using a plating bath in which K ₂ TiF ₆ is added to LiF—NaF—KF.

JP 2015-193899 A

A. ROBIN et. al. , "ELECTROLYTIC COATING OF TITANIUM ONTO IRON AND NICKEL ELECTORDES IN THE MOLTEN LiF + NaF + KF EUTECTIC", Journal of Electronic. Chem. , 230 (1987) pp. 125-141

  A method for manufacturing a titanium-plated member according to one embodiment of the present disclosure includes a step of preparing a base material having a conductive surface, and forming the base material with at least one Group 1 metal ion of lithium ions and sodium ions. A step of immersing in a molten salt titanium plating solution composition containing fluoride ions and titanium ions, and energizing such that the base material immersed in the molten salt titanium plating solution composition becomes a cathode, A step of forming a titanium plating film on the surface by coating the surface of the base material with titanium, and forming the titanium plating film on an alkali metal chloride, an alkaline earth metal chloride and potassium fluoride. Washing the titanium plating film by contacting with a washing molten salt containing at least one compound selected from the group consisting of A step of removing a first deposit attached to the surface of the titanium plating film in the step of forming the titanium plating film, and a step of washing the titanium plating film with water and washing with the cleaning molten salt. Removing the second deposit attached to the surface.

FIG. 1 is a schematic sectional view showing an example of a part of a titanium plating member. FIG. 2 is a flowchart showing a procedure for manufacturing a titanium plated member. FIG. 3 is a schematic cross-sectional view showing an example of a state in which a substrate is immersed in a molten salt titanium plating solution composition. FIG. 4 is a graph showing the corrosion current density of each electrode in a physiological saline solution. FIG. 5 is a graph showing the correlation between the current density of each electrode and the potential in the simulated seawater. FIG. 6 is a graph showing the correlation between the current density and the potential of each electrode in a simulated electrolyte of a polymer electrolyte fuel cell (PEFC). FIG. 7 is another graph showing the correlation between the current density and the potential of each electrode in a simulated electrolyte of a polymer electrolyte fuel cell (PEFC).

[Problems to be solved by the present disclosure]
In order to obtain a titanium plating film having a smooth surface in titanium plating, it is important that fluoride ions exist in the plating bath. However, fluoride ions may combine with metal ions present in the plating bath to form poorly water-soluble metal fluoride. If the poorly water-soluble metal fluoride remains on the surface of the titanium plating film of the plating member, it is difficult to sufficiently remove it by washing with water. Therefore, there has been a demand for a method of manufacturing a titanium plated member that can reduce the residual amount of the poorly water-soluble fluoride on the surface of the plated member.

  Therefore, it is an object to provide a method for manufacturing a titanium plated member that can reduce the residual amount of poorly water-soluble fluoride on the surface of a titanium plated film.

[Effects of the present disclosure]
According to the method for manufacturing a titanium-plated member, it is possible to reduce the residual amount of the poorly water-soluble fluoride on the surface of the titanium-plated film.

[Description of Embodiment of the Present Disclosure]
First, embodiments of the present disclosure will be listed and described.

  [1] In a method for manufacturing a titanium-plated member according to an embodiment of the present disclosure, a step of preparing a base material having a conductive surface, and forming the base material in at least one group 1 of lithium ions and sodium ions A step of immersing in a molten salt titanium plating solution composition containing metal ions, fluoride ions, and titanium ions, such that the base material immersed in the molten salt titanium plating solution composition becomes a cathode; Energizing, by coating the surface of the base material with titanium, forming a titanium plating film on the surface, the titanium plating film, an alkali metal chloride, an alkaline earth metal chloride and The titanium plating film is washed by bringing it into contact with a washing molten salt containing at least one compound selected from the group consisting of potassium fluoride. The step of removing the first deposit attached to the surface of the titanium plating film in the step of forming the titanium plating film, and the step of washing the titanium plating film with water and washing with the washing molten salt. Removing the second deposit attached to the surface of the film.

  Titanium has a strong bonding force with oxygen and easily reacts with water to form oxides and hydroxides, and is not suitable for plating from an aqueous solution. Therefore, in order to form a titanium plating film on a base material, a plating bath of a molten salt titanium plating solution composition composed of a molten salt containing titanium ions is used.

  It is known that the presence of fluoride ions in the molten salt titanium plating solution composition is important for obtaining a titanium plating film having a smooth surface from the molten salt titanium plating solution composition. Therefore, a molten salt titanium plating solution composition containing a predetermined amount of a metal fluoride as a source of fluoride ions is selected. Potassium fluoride is used as a metal fluoride serving as a source of fluoride ions.

Furthermore, alkali metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF) are typical metal fluorides serving as sources of fluoride ions. Lithium fluoride (LiF) and sodium fluoride (NaF) lithium ion in the molten salt (LI ⁺⁾ or sodium ion (Na ^+), fluoride ions ^- ionized in the (F). Although these LI ⁺ , Na ⁺ , and F ⁻ effectively act in a molten salt to be plated, there is a problem that LiF and NaF reformed after plating are poorly water-soluble and thus cannot be sufficiently removed by washing with water. is there. In particular, when the substrate to be plated is a structure having a complicated shape such as a porous shape, it is difficult to sufficiently remove the poorly water-soluble metal fluoride from the plating film only by washing with water. Therefore, it is required to reduce the residual amount of poorly water-soluble fluoride on the surface of the titanium plating film.

  The method for manufacturing a titanium-plated member of the present disclosure includes, after forming a titanium-plated film, forming the titanium-plated film at least selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides, and potassium fluoride. A step of forming a titanium plating film by removing the first deposit attached to the surface of the titanium plating film by washing the titanium plating film by contacting with a cleaning molten salt containing one compound; . The first deposit contains either or both of poorly water-soluble LiF and NaF. Since the compound contained in the molten salt for cleaning has higher compatibility with LiF and NaF than water, the compound is washed with the molten salt for cleaning to remove the first deposit, thereby obtaining titanium. The amount of LiF and NaF remaining on the surface of the plating film can be reduced.

  The method for manufacturing a titanium-plated member according to the present disclosure further includes a step of washing the titanium-plated film with water and removing the second deposit attached to the surface of the titanium-plated film in the step of washing with the molten salt for washing. . Alkali metal chloride, alkaline earth metal chloride, and potassium fluoride contained in the cleaning molten salt have higher solubility in water than LiF and NaF. Therefore, after the step of washing with the molten salt for washing, the surface of the titanium plating film is further washed with water to remove the second deposit, thereby reducing the amount of residues on the surface of the titanium plating film. Can be.

  [2] In the step of removing the first deposit, the contact of the titanium plating film with the molten salt for cleaning may be performed by immersing the substrate on which the titanium plated film is formed in the molten salt for cleaning. May be performed. As a method of contacting the titanium plating film with the molten salt for cleaning, a method of immersing the substrate on which the titanium plated film is formed in the molten salt for cleaning is employed, so that the entire surface of the titanium plating film is sufficiently molten for cleaning. Salt can be contacted. As a result, the residual amount of poorly water-soluble substances such as LiF and NaF on the surface of the titanium plating film can be more suitably reduced.

  [3] The molten salt titanium plating solution composition may further contain chloride ions. By containing chloride ions together with fluoride ions, it is possible to lower the melting point of the molten salt titanium plating solution composition by lowering the melting point. As a result, titanium plating can be performed at a lower temperature.

  [4] In the molten salt titanium plating solution composition, the amount of fluoride ions may be 30 mol% or more and 50 mol% or less based on a total of 100 mol% of the chloride ions and the fluoride ions. Within such a range, the melting point of the molten salt titanium plating solution composition can be further reduced. As a result, it is possible to perform titanium plating at a still lower temperature.

  [5] The content of the titanium ion is preferably 0.1 mol% or more and 12 mol% or less based on 100 mol% of all cations contained in the molten salt titanium plating solution composition. Thereby, a titanium plated member having a titanium plated film as a protective film having high hardness, high surface smoothness, and excellent corrosion resistance and wear resistance can be manufactured with high yield.

  [6] The titanium-plated member is preferably an insoluble electrode. This makes it possible to provide an insoluble electrode having a titanium plating film in which the amount of residue on the surface is reduced.

  [7] The titanium plating member is preferably a current collector. Thereby, it is possible to provide a current collector having a titanium plating film in which the amount of residue on the surface is reduced.

  [8] The titanium-plated member is preferably a biomaterial. This makes it possible to provide a biomaterial having a titanium plating film with a reduced amount of residue on the surface. Such a biomaterial can also be excellent in corrosion resistance.

[Details of Embodiment of the Present Disclosure]
Next, with reference to the drawings, details of one embodiment of a method for manufacturing a titanium plated member of the present disclosure will be described below. In the present specification, the notation of the form “A to B” means the upper and lower limits of the range (that is, A or more and B or less), and when a unit is not described in A and a unit is described only in B, A And the unit of B are the same.

[Production method of titanium plated member]
With reference to FIGS. 1 to 3, a method for manufacturing a titanium plated member in the present embodiment will be described. FIG. 1 is a schematic sectional view showing an example of a part of a titanium plating member. FIG. 2 is a flowchart showing a procedure for manufacturing a titanium plated member. FIG. 3 is a schematic cross-sectional view showing an example of a state in which a substrate is immersed in a molten salt titanium plating solution composition.

  Referring to FIG. 1, titanium-plated member 1 includes a base material 10 and a titanium-plated film 20 (hereinafter, also simply referred to as “plated film 20”) formed on the surface of base material 10. The plating film 20 is a film made of titanium. The titanium plated member 1 is manufactured through steps S10 to S50 shown in FIG.

  In the method for manufacturing the titanium-plated member 1 according to the present embodiment, a step (S10) of preparing a base material 10 having a conductive surface and a step of preparing the base material 10 by at least one of lithium ion and sodium ion Immersing in a molten salt titanium plating solution composition (hereinafter, also referred to as “plating solution composition”) 50 containing group metal ions, fluoride ions, and titanium ions (S20); Energizing the substrate 10 immersed in the liquid composition 50 to become a cathode, and covering the surface of the substrate 10 with titanium, thereby forming a titanium plating film 20 on the surface (S30); The method includes a step of cleaning the surface of the titanium plating film 20 with a cleaning molten salt (S40) and a step of washing the surface of the titanium plating film 20 with water (S50).

  In the step (S40) of cleaning the surface of the titanium plating film 20 with the cleaning molten salt, the titanium plating film 20 is formed by cleaning the titanium plating film 20 with at least one selected from the group consisting of an alkali metal chloride, an alkaline earth metal chloride and potassium fluoride. The first deposit attached to the surface of the titanium plating film 20 in the step of forming the titanium plating film 20 is removed by contacting the titanium plating film 20 with a cleaning molten salt containing one compound to remove the first deposit. It is a process. In the step of washing the surface of the titanium plating film 20 with water (S50), the second deposit attached to the surface of the titanium plating film 20 in the step of washing the titanium plating film 20 with water and washing with a molten salt for washing is removed. It is a process. In addition, the method of manufacturing the titanium plated member 1 of the present embodiment may include steps other than S10, S20, S30, S40, and S50. Hereinafter, each of these steps will be described.

  First, a substrate 10 having a conductive surface is prepared (S10). The material constituting the base material 10 is not particularly limited as long as the material has a conductive surface. Examples of the substrate 10 include a substrate made of iron or nickel, a substrate made of an alloy thereof, a multilayer substrate having a layer of iron, nickel, or an alloy thereof on the surface.

  The shape of the substrate 10 is not particularly limited. For example, the base material 10 having various shapes such as a plate shape, a column shape, a pipe shape, and a mesh shape can be adopted as the base material 10.

Next, the base material 10 is immersed in the plating solution composition 50 (S20). Referring to FIG. 3, the plating solution composition 50 includes at least one Group 1 metal ion of lithium ion (Li ⁺ ) and sodium ion (Na ⁺ ), a fluoride ion (F ⁻ ), and titanium. Ions (Tin ⁺ (n is an integer of 2 or more and 4 or less; the same applies hereinafter)). In this case, the plating solution composition 50 can contain a plurality of types having different valences as titanium ions. It is preferable that the plating solution composition 50 further contains a chloride ion (Cl ⁻ ).

The plating solution composition 50 includes, for example, a mixture of at least one of lithium fluoride (LiF) and sodium fluoride (NaF) and at least one of lithium chloride (LiCl) and sodium chloride (NaCl). It can be prepared as a molten salt by dissolving a titanium compound which is a source of Tin ⁺ .

Examples of Ti ^{n +} source and becomes titanium compound, hexafluoro titanic acid (H ₂ TiF _6), potassium Chitanfu' of (K ₂ TiF _6), Chitanfu' ammonium _{((NH 4) 2 TiF 6} ), Chitanfu' of Soda (Na ₂ TiF ₆ ), potassium potassium oxalate dihydrate (K ₂ TiO (C ₂ O ₄ ) ₂ .2H ₂ O), titanium chloride (III) (TiCl ₃ ), titanium chloride (IV) (TiCl ₄ ) and the like.

The plating solution composition 50 may include a cation other than Li ⁺ and Na ⁺ . For example, the plating solution composition 50 may contain potassium ions (K ⁺ ). However, if the plating solution composition 50 contains a large amount of K ⁺ , potassium mist may be generated during plating. Therefore, the content of potassium ions with respect to 100 mol% of all ionic components in the plating solution composition is preferably 5 mol% or less. Since the Chitanfu' potassium (K ₂ TiF ₆₎ and potassium titanium oxalate dihydrate _{(K 2 TiO (C 2 O} 4) 2 · 2H 2 O) , including potassium ions, these titanium compounds Ti ^{n +} a When used as a supply source, it is used in an amount such that the content of K ⁺ with respect to 100 mol% of the total ionic components contained in the plating solution composition 50 is 5 mol% or less, or other K ⁺ is not generated. It is preferably used in combination with a titanium compound (for example, titanium (IV) chloride).

In the plating solution composition are molten salt, LiF, NaF, LiCl and NaCl are ionized ^{respectively, Li +, Na +, F} - is present in the state ^- and Cl. Similarly, the titanium compound is ionized and exists in the state of Ti ^{n +} . Thus, it is preferable to prepare a plating solution composition containing at least one Group 1 metal ion of Li ⁺ and Na ⁺ , F ⁻ , Cl ⁻ , and Tin ⁺ as a molten salt. .

The presence of Li ⁺ , Na ⁺ , F ⁻ , Cl ^−, and Tin ^{+ in} the plating solution composition 50 of the present embodiment means that the plating solution composition 50 is dissolved in a mixed solution of nitric acid and hydrofluoric acid, for example. The solution can be confirmed by analyzing the solution by ICP emission spectroscopy (Inductively Coupled Plasma Spectrometry). As the ICP emission spectrometer, for example, iCAP6200 manufactured by Thermo Fisher Scientific Co., Ltd. can be used.

The plating solution composition 50 preferably has an amount of F ⁻ of 30 mol% or more and 50 mol% or less based on 100 mol% of the total of Cl ⁻ and F ⁻ . F ^- for the Cl ^- increasing the proportion of, after once melting point of the molten salt is lowered by melting point depression, increases again. Cl ^- and F ^- F to the total 100 mol% of the ^- is a large melting point depression effect when in a predetermined range ratio. Specifically, Cl ^- and F ^- the sum F for 100 mol% of the ^- so long as the amount is less 30 mol% or more 50 mol% of a large drop of the melting point, is easy to perform plating at lower temperatures Become. It is more preferable that the amount of F ⁻ in the range of 30 mol% or more and 45 mol% or less relative to the total of 100 mol% of Cl ⁻ and F ⁻ , because the amount of decrease in the melting point is large.

In the plating solution composition 50 of the present embodiment, the anion fraction of F ⁻ (the ratio (molar ratio) of F ⁻ to the total amount of anions) is preferably 0.1 or more and 0.9 or less. More preferably, it is 25 or more and 0.75 or less. When the anion fraction of F ⁻ is 0.1 or more, particularly 0.25 or more, the titanium plated member 1 having the plating film 20 with high surface smoothness can be obtained more reliably. On the other hand, when the anion fraction of F ⁻ is 0.9 or less, particularly when it is 0.75 or less, it tends to be easy to remove the residual substances after the formation of the plating film 20. Therefore, F ^- is preferably an anion fraction of within the above range.

The content of Tin ⁺ in the plating solution composition is not particularly limited, and is appropriately set according to plating conditions. However, when the content of T in ⁺ is too large, an unnecessary precipitate is formed, and the current efficiency is greatly reduced. On the other hand, ^if the content of Tin ⁺ is too small, the titanium plating film cannot be formed sufficiently. Therefore, the content of Tin ⁺ is preferably 20 mol% or less, more preferably 12 mol% or less, based on 100 mol% of all cations in the plating solution composition. The content of Tin ⁺ is preferably at least 0.1 mol%, more preferably at least 0.5 mol%, based on 100 mol% of all cations in the plating solution composition. That is, the content of the titanium ion with respect to 100 mol% of all cations contained in the molten salt titanium plating solution composition is preferably 0.1 mol% or more and 12 mol% or less.

  Next, a current is applied so that the substrate 10 immersed in the plating solution composition 50 becomes a cathode, and the surface of the substrate 10 is coated with titanium to form a titanium plating film 20 on the surface (S30). . In the step of forming the plating film 20, a voltage is applied between the anode 30 immersed in the plating solution composition 50 and the substrate 10 as a cathode while the substrate 10 is immersed in the plating solution composition 50. It is carried out by applying a current and applying electricity to perform electrolysis of the plating solution composition 50. As a result, titanium ions are reduced to titanium on the surface of the base material 10 serving as the cathode, and the surface of the base material 10 is coated with titanium, whereby the plating film 20 is formed on the surface of the base material 10.

The electrolysis of the plating solution composition 50 is performed so that the absolute value of the current density of the current flowing between the anode 30 and the substrate 10 on the substrate 10 is 1 mA / cm ² or more and 500 mA / cm ² or less. It is more preferable that the absolute value of the current density be 1 mA / cm ² or more and 300 mA / cm ² or less. When the plating solution composition 50 is electrolyzed so that the absolute value of the current density of the current flowing between the anode 30 and the substrate 10 is 1 mA / cm ² or more, the plating on the surface of the substrate 10 The film 20 can be formed in a shorter time. On the other hand, when the electrolysis of the plating solution composition 50 is performed so that the absolute value of the current density of the current flowing between the anode 30 and the base material 10 is 500 mA / cm ² or less, particularly 300 mA / cm ² or less. Thus, the plating film 20 having higher surface smoothness can be formed.

  Next, the surface of the plating film 20 is washed with a washing molten salt (S40). Specifically, the titanium plating film 20 is brought into contact with a cleaning molten salt containing at least one compound selected from the group consisting of alkali metal chloride, alkaline earth metal chloride and potassium fluoride. By cleaning the titanium plating film 20, the first deposit attached to the surface of the titanium plating film 20 in the step of forming the titanium plating film 20 is removed by cleaning with a cleaning molten salt.

  The first deposit contains either or both of poorly water-soluble LiF and NaF. Since the compound contained in the molten salt for cleaning has higher compatibility with water than LiF and NaF, the LiF and NaF remaining on the surface of the plating film 20 are subjected to the step of cleaning with the molten salt for cleaning. Can be reduced.

Examples of the alkali metal chloride include lithium chloride (LiCl), sodium chloride (NaCl), and potassium chloride (KCl). Examples of the alkaline earth metal chloride include magnesium chloride (MgCl ₂ ) and calcium chloride (CaCl ₂ ). The molten salt may contain these alkali metal chlorides, alkaline earth metal chlorides and potassium fluoride alone or in combination of two or more. The molten salt may contain salts other than these alkali metal chlorides, alkaline earth metal chlorides and potassium fluoride.

  Alkali metal chlorides, alkaline earth metal chlorides and potassium fluoride (KF) have higher compatibility with LiF and NaF than water. Therefore, the amount of LiF and NaF on the surface of the plating film 20 can be reduced by bringing the plating film 20 into contact with the cleaning molten salt.

  The method of bringing the plating film 20 into contact with the molten salt for cleaning is not particularly limited. For example, a method of immersing the base material 10 on which the plated film 20 is formed in the molten salt for cleaning, flowing the molten salt on the surface of the plating film 20, A method of cleaning the surface of the plating film 20 by spraying or the like may be used. Of these methods, the method of bringing the plating film 20 into contact with the cleaning molten salt is preferably performed by immersing the substrate 10 on which the plating film 20 is formed in the cleaning molten salt. As the contacting method, by dipping the substrate 10 on which the plating film 20 is formed in the molten salt for cleaning, the molten salt for cleaning can be sufficiently contacted over the entire surface of the plating film 20. As a result, poorly water-soluble substances such as LiF and NaF on the surface of the plating film 20 can be more effectively cleaned.

  Finally, the surface of the plating film 20 is washed with water (S50). In this step, the titanium deposit film 20 is washed with water, and the second deposit attached to the surface of the plating film 20 in the step of washing with the molten salt for washing (S40) is removed.

  Through the step of cleaning the surface of the plating film 20 with the cleaning molten salt (S40), the residual amounts of poorly water-soluble LiF and NaF on the surface of the plating film 20 are reduced. After the step of washing with the washing molten salt, the second deposits attached to the surface of the plating film 20 mainly include the components contained in the washing molten salt, that is, the alkali metal chloride and the alkaline earth metal chloride. And KF. Alkali metal chlorides, alkaline earth metal chlorides and KF are not only compatible with LiF and NaF, but also have high water solubility. Therefore, the second deposit can be more easily removed by water washing than LiF and NaF. By passing through the two-step cleaning process (S40 and S50), the residual substances remaining on the surface of the plating film 20 can be reduced. As a result, a high-quality titanium-plated member 1 having a small amount of residual impurities can be manufactured.

  In washing with water, a water-soluble solvent such as alcohol and another detergent such as a surfactant may be used together with water. Thus, the titanium plating member 1 in which the plating film 20 is formed on the surface of the substrate 10 is manufactured.

[Titanium plated members]
The titanium-plated member 1 manufactured as described above is a member having a high hardness, a high surface smoothness, and a protective film having excellent corrosion resistance and abrasion resistance. Furthermore, the high quality titanium plated member 1 having a small amount of residual impurities on the plating film 20 is provided. Therefore, it can be used in various fields.

  The ratio ((Ra / R) × 100 (%)) of the surface average roughness Ra to the average thickness R of the plating film 20 in the titanium plating member 1 manufactured by the above manufacturing method is preferably 10% or less. More preferably, it is 5% or less. Within such a range, it is possible to provide the titanium plating member 1 having the plating film 20 having sufficiently high surface smoothness.

  The surface average roughness Ra of the plating film 20 can be measured by observing a cross section by SEM (Scanning Electron Microscope) or using a surface roughness meter. Further, the average thickness R of the plating film 20 can be determined by observing a cross section with a SEM. The surface average roughness Ra of the plating film 20 means an arithmetic average roughness Ra specified in JIS B0601 (2001). The average thickness R of the plating film 20 means, for example, the arithmetic average of the thickness of the plating film 20 at any 10 points in the SEM image.

  As described above, according to the method for manufacturing the titanium plated member 1 according to the present embodiment, it becomes possible to reduce the residual amount of the poorly water-soluble fluoride on the surface of the titanium plated film.

In the above embodiment, the molten salt titanium plating solution composition 50 containing chloride ions (Cl ⁻ ) has been described, but the molten salt titanium plating solution composition 50 can be prepared without containing Cl ^−. . When Cl ^- is not contained, the molten salt titanium plating solution composition 50 can be prepared so as to contain other anions instead. In this case, the other anions are desirably selected so as to be stable even at the plating temperature and not to form a residue such as a salt which is difficult to remove after plating.

  Here, the titanium plating member is preferably an insoluble electrode. This makes it possible to provide an insoluble electrode having a titanium plating film in which the amount of residue on the surface is reduced.

  Such an insoluble electrode is preferably used for producing hydrogen. When the insoluble electrode is used for producing hydrogen, it can be provided as a low-resistance insoluble electrode for producing hydrogen. This makes it possible to produce high-purity hydrogen.

  The titanium plating member is preferably a current collector. Thereby, it is possible to provide a current collector having a titanium plating film in which the amount of residue on the surface is reduced.

  Such a current collector is preferably for a fuel cell. When the current collector is for a fuel cell, it can be provided as a fuel cell current collector having good electric conductivity. In particular, when the current collector is for a fuel cell, it is more preferable that the current collector is for a polymer electrolyte fuel cell.

  It is preferable that the titanium plating member is a biomaterial. This makes it possible to provide a biomaterial having a titanium plating film with a reduced amount of residue on the surface. Such a biomaterial can also be excellent in corrosion resistance.

  The use of the biomaterial is preferably selected from the group consisting of a spinal fixation device, a fracture fixation material, an artificial joint, an artificial valve, an intravascular stent, a denture base, an artificial root, and an orthodontic wire.

  Hereinafter, the embodiment will be described more specifically with reference to examples. The present disclosure is not limited to these examples.

<< Example 1 >>
[Preparation of molten salt titanium plating solution composition and preparation of titanium plating member]
In order to prepare a titanium-plated member to be a test body, 2 mol of K ₂ TiF ₆ powder or 13 mol of TiCl ₄ as a titanium source was dissolved in 100 mol of a base material of a molten salt titanium plating solution composition shown in Table 1 below. First, the sample No. 1 to No. A molten salt titanium plating solution composition of No. 4 was prepared.

  As shown in Table 1, the sample No. 1 to No. The molten salt titanium plating solution composition of No. 4 has a potassium ion content of 5 mol% or less based on 100 mol% of all ionic components contained in the composition. Further, the sample No. The molten salt titanium plating solution composition of No. 1 is a sample in which the amount of fluoride ions is more than 50 mol% (51 mol%) with respect to the total of 100 mol% of chloride ions and fluoride ions. Sample No. The molten salt titanium plating solution composition 2 is a sample containing no chloride ion. Sample No. 3 and No. 3 The molten salt titanium plating solution composition of No. 4 is a sample in which the amount of fluoride ions is 30 mol% or more and 50 mol% or less with respect to a total of 100 mol% of chloride ions and fluoride ions. The sample No. 1 to No. The molten salt titanium plating solution composition of No. 4 had a titanium ion content of 0.1 mol% or more and 12 mol% or less (1.9 mol% or 11.5 mol%) based on 100 mol% of all cations contained in the composition. It is.

  Next, through the steps S10 to S30 (see FIG. 2) in the above-described method for manufacturing a titanium plated member, the sample No. 1 to No. Using the molten salt titanium plating solution composition of No. 4, titanium plating was performed on the surface of a substrate (made of nickel, 0.1 mm thick, 5 mm × 25 mm square). As a result, the specimen No. 1 to No. 4 was prepared.

  Here, the sample No. The titanium plating member precursor produced using the molten salt titanium plating solution composition of Test Sample No. 1 This corresponds to one titanium plated member precursor. Sample No. The titanium plating member precursor produced using the molten salt titanium plating solution composition of Test Sample No. 2 2 corresponds to the titanium plated member precursor. Sample No. The titanium-plated member precursor produced using the molten salt titanium plating solution composition of Test Sample No. 3 3 corresponds to the titanium plated member precursor. Sample No. Titanium-plated member precursor produced using the molten salt titanium plating solution composition of Test Sample No. 4 4 corresponds to the titanium plated member precursor.

  Further, through the steps of S40 to S50 (see FIG. 2) in the above-described method for manufacturing a titanium plated member, the molten salt for cleaning A to D shown in Table 2 and pure water are used, using the molten salt for cleaning A shown in Table 2. Specimen No. The first titanium-plated member precursor was washed to remove the first and second deposits on its surface. Specifically, the specimen No. Five titanium plating member precursors of No. 1 were prepared and immersed in a container containing the molten salt for cleaning A to the molten salt for cleaning D shown in Table 2 and pure water for 10 minutes (S40). Thereafter, the specimen No. The titanium-plated member precursor No. 1 was pulled out of each container, and was subjected to ultrasonic cleaning with pure water for 10 minutes (S50). Thereby, the specimen No. A titanium plated member of No. 1 was produced. Here, the molten salt D for cleaning and pure water are cleaning agents serving as comparative controls.

  Next, the above five test specimen Nos. EDX (trade name: "X-act", manufactured by Oxford Instruments Co., Ltd.) attached to a scanning electron microscope (trade name: "VE-8800", manufactured by Keyence Corporation) for the titanium-plated member of No. 1 Was used under the conditions of an acceleration voltage of 15 kV to analyze the presence or absence of metal fluoride and the residual components of the molten salt for cleaning A to the molten salt for cleaning D. The results are shown in the EDX column of Table 2. The “salt component” in Table 2 means the metal fluoride and the residual components of the molten salt for cleaning A to the molten salt for cleaning D.

  From the results in Table 2, the molten salt for cleaning containing at least one compound selected from the group consisting of chlorides of alkali metals, chlorides of alkaline earth metals, and potassium fluoride (molten salts for cleaning A to cleaning salts) It can be seen that the metal fluoride and the residual components of the molten salt did not remain on the surface of the titanium plating member washed with the molten salt C).

<< Example 2 >>
Specimen No. prepared in Example 1 Five titanium plated member precursors No. 2 were prepared. This test piece No. By performing the steps S40 to S50 (see FIG. 2) in the method for manufacturing a titanium-plated member under the same conditions as in Example 1, the surface of the titanium-plated member precursor The first and second deposits were removed. As a result, the specimen No. A titanium plated member of No. 2 was produced. Further, the specimen No. The titanium plated member of No. 2 was analyzed under the same conditions as in Example 1 for the presence or absence of metal fluoride and the residual components of the molten salt for cleaning A to the molten salt for cleaning D. The results are shown in the EDX column of Table 3. “Salt component” in Table 3 also means the residual components of metal fluoride and molten salt A for cleaning to molten salt D for cleaning.

  From the results in Table 3, the molten salt for cleaning containing at least one compound selected from the group consisting of chlorides of alkali metals, chlorides of alkaline earth metals, and potassium fluoride (molten salts for cleaning A to cleaning) It can be seen that the metal fluoride and the residual components of the molten salt did not remain on the surface of the titanium plating member washed with the molten salt C).

Example 3
Specimen No. prepared in Example 1 Five titanium plated member precursors No. 3 were prepared. This test piece No. By performing the steps S40 to S50 (see FIG. 2) in the method for manufacturing a titanium-plated member under the same conditions as in Example 1 for the titanium-plated member precursor of No. 3, the surface of the titanium-plated member precursor The first and second deposits were removed. As a result, the specimen No. A titanium plated member of No. 3 was produced. Further, the specimen No. The titanium plated member of No. 3 was analyzed under the same conditions as in Example 1 for the presence or absence of metal fluoride and the residual components of the molten salt for cleaning A to the molten salt for cleaning D. The results are shown in the column of EDX in Table 4. The “salt component” in Table 4 also means the residual components of the metal fluoride and the molten salt A for cleaning to the molten salt D for cleaning.

  From the results shown in Table 4, the molten salt for cleaning containing at least one compound selected from the group consisting of chlorides of alkali metals, chlorides of alkaline earth metals and potassium fluoride (molten salts for cleaning A to cleaning salts) It can be seen that the metal fluoride and the residual components of the molten salt did not remain on the surface of the titanium plating member washed with the molten salt C).

Example 4
Specimen No. prepared in Example 1 Five titanium plated member precursors of No. 4 were prepared. This test piece No. By performing the steps S40 to S50 (see FIG. 2) of the titanium-plated member production method under the same conditions as in Example 1 for the titanium-plated member precursor of Example 4, the surface of the titanium-plated member precursor was obtained. The first and second deposits were removed. As a result, the specimen No. 4 was produced. Further, the specimen No. Each titanium-plated member of No. 4 was analyzed under the same conditions as in Example 1 for the presence of metal fluoride and the residual components of the molten salt for cleaning A to the molten salt for cleaning D. The results are shown in the column of EDX in Table 5. The “salt component” in Table 5 also means the residual components of the metal fluoride and the molten salt A for cleaning to the molten salt D for cleaning.

  From the results in Table 5, the molten salt for cleaning containing at least one compound selected from the group consisting of chlorides of alkali metals, chlorides of alkaline earth metals and potassium fluoride (molten salts for cleaning A to cleaning salts) It can be seen that the metal fluoride and the residual components of the molten salt did not remain on the surface of the titanium plating member washed with the molten salt C).

  As described above, according to the method for manufacturing a titanium-plated member according to the present embodiment, the titanium-plated film is at least selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides, and potassium fluoride. A metal fluoride remaining on the surface of the titanium plating film and a residual component of the cleaning molten salt by washing the titanium plating film by contact with a cleaning salt containing one compound and washing the titanium plating film with water. (For example, LiF and NaF) can be reduced.

Example 5
[Corrosion resistance to physiological saline]
The following Ti-plated products were evaluated for corrosion resistance to physiological saline according to the following procedure.

(Preparation of specimen)
By going through S10 to S50 of the above-described method for producing a titanium plated member, a nickel porous substrate (3 cm × 5 cm × 1 mmt, porosity of 96%, average pore diameter of 300 μm, hereinafter referred to as “nickel porous body”) The surface of (1) was subjected to titanium plating to produce a Ti-plated product.

  On the other hand, as a test body of a comparative example, a Ni porous body (trade name: "Celmet (registered trademark)", manufactured by Sumitomo Electric Industries, Ltd.) and a Ti metal plate (manufactured by Nilaco Corporation) were prepared.

(Corrosion resistance test)
Cyclic voltammetry was performed under the following conditions. FIG. 4 shows the results. In FIG. 4, the test specimen of the example and the test specimen of the comparative example (the porous body of Ni and the metal plate of Ti) are denoted as “Ti plated product”, “Ni” and “Ti”, respectively.

<Conditions for cyclic voltammetry>
Electrolyte solution: 0.9 mass% sodium chloride aqueous solution (physiological saline)
Working electrode: Specimen of Example or Specimen of Comparative Example (Ti plated product, Ni or Ti)
Reference electrode: Ag / AgCl electrode Counter electrode: Ni metal plate Scanning speed: 10 mV / sec
Liquid temperature: 25 ° C.

  The results of FIG. 4 indicate that the Ti plated product of the example has a lower corrosion current density than the porous Ni body of the comparative example, and is stable in a physiological saline environment. Was done. From this result, it was found that the Ti plated product of the example was suitable as a biomaterial. Furthermore, the corrosion current density of the Ti plated product of the example was suppressed to be lower than that of the Ti metal plate of the comparative example. From these results, it was shown that the stability to the physiological saline environment was further improved by adopting the structure of the porous metal body instead of the metal plate.

Example 6
[Corrosion resistance to salt water simulating seawater]
The following Ti-plated products were evaluated for corrosion resistance to salt water simulating seawater according to the following procedure.

(Preparation of specimen)
As a test piece of the example, a Ti-plated product prepared by the same method as the Ti-plated product used in Example 5 was prepared. A Ti metal plate (manufactured by Niraco Co., Ltd.) was prepared as a test body of a comparative example.

(Corrosion resistance test)
Cyclic voltammetry was performed under the same conditions as those described in the section of [Corrosion Resistance to Physiological Saline], except that 3.3% by mass of saline simulating seawater was used as the electrolytic solution. FIG. 5 shows the results. In FIG. 5, the test specimen of the example and the test specimen of the comparative example are described as “Ti plated product” and “Ti commercial product”, respectively.

  From the results of FIG. 5, it was found that the Ti-plated product of the example had a lower current density than the Ti commercial product of the comparative example, and exhibited high corrosion resistance to seawater. As a result, it was found that the Ti-plated product of the example was promising as an insoluble electrode (anode) for salt electrolysis.

Example 7
[Evaluation of suitability for polymer electrolyte fuel cell]
The following procedure evaluated the suitability of the following Ti-plated products for polymer electrolyte fuel cells.

(Preparation of specimen)
As a test piece of the example, a Ti-plated product prepared by the same method as the Ti-plated product used in Example 5 was prepared. As test specimens of Comparative Examples, a porous Ni body (trade name: "Celmet (registered trademark)", manufactured by Sumitomo Electric Industries, Ltd.) and a metal plate of Ti (manufactured by Nilaco Corporation) were prepared.

(Appropriate evaluation)
Except for using a 10% by mass aqueous sodium sulfate solution (adjusted to pH = 3 by adding sulfuric acid) (PEFC simulated electrolyte solution) as the electrolyte solution, the conditions shown in the above column of [Corrosion resistance to physiological saline] were used. Cyclic voltammetry was performed under the same conditions. The results are shown in FIGS. In FIG. 6 and FIG. 7, the test specimen of the example and the test specimen of the comparative example (the porous body of Ni and the metal plate of Ti) were respectively referred to as “Ti plated product”, “Ni comparison”, and “Ti comparison”. It was written. In FIG. 6, the plots of the correlation between the current density and the potential of each electrode in “Ti plated product” and “Ti comparison” were duplicated, so the vertical axis (current density) in FIG. As a result, the plots of the above-described correlations in the “Ti plated product” and the “for Ti comparison” are made to be distinguishable.

  From the results of FIGS. 6 and 7, the current density of the Ti-plated product of the example is lower than that of the Ni-comparative product of the comparative example, and the current collector used in the polymer electrolyte fuel cell. It proved promising as a material.

  It should be understood that the embodiments and examples disclosed this time are exemplifications in all respects and are not restrictive in any aspect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 titanium plating member, 10 base material, 20 plating film, 30 anode, 40 container, 50 plating solution composition.

Claims (8)

Preparing a substrate having a conductive surface,
Immersing the base material in a molten salt titanium plating solution composition containing at least one Group 1 metal ion of lithium ions and sodium ions, fluoride ions, and titanium ions;
Energizing so that the substrate immersed in the molten salt titanium plating solution composition becomes a cathode, and covering the surface of the substrate with titanium, thereby forming a titanium plating film on the surface; ,
The titanium plating film is contacted with a cleaning molten salt containing at least one compound selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides and potassium fluoride to form the titanium plating film. Washing, removing a first deposit attached to the surface of the titanium plating film in the step of forming the titanium plating film;
Washing the titanium plating film with water and removing the second deposits attached to the surface of the titanium plating film in the step of washing with the washing molten salt.   In the step of removing the first deposit, the contact of the titanium plating film with the molten salt for cleaning is performed by immersing the substrate on which the titanium plated film is formed in the molten salt for cleaning. The method for producing a titanium plated member according to claim 1.   The method for producing a titanium plated member according to claim 1 or 2, wherein the molten salt titanium plating solution composition further contains chloride ions.   The titanium plating member according to claim 3, wherein the molten salt titanium plating solution composition has an amount of the fluoride ions of 30 mol% or more and 50 mol% or less based on a total of 100 mol% of the chloride ions and the fluoride ions. Manufacturing method.   The content of the titanium ion with respect to 100 mol% of all cations contained in the molten salt titanium plating solution composition is 0.1 mol% or more and 12 mol% or less, according to any one of claims 1 to 4. A method for producing a titanium plated member.   The method for manufacturing a titanium plated member according to any one of claims 1 to 5, wherein the titanium plated member is an insoluble electrode.   The method for manufacturing a titanium-plated member according to any one of claims 1 to 5, wherein the titanium-plated member is a current collector.   The method for manufacturing a titanium-plated member according to any one of claims 1 to 5, wherein the titanium-plated member is a biomaterial.

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