Zinc-based plating film manufacturing method and plating equipment

Abstract

To provide a method of stably producing an alkaline zinc-based plated film.SOLUTION: The method of producing a zinc-based plated film according to the present invention, includes dissolving a metal ingot including zinc using an alkaline electrolytic solution including a component obtained by dialyzing an alkaline plating solution and adding the electrolytic solution including the dissolved metal ingot including zinc to the plating solution. It is preferable that the concentration of the alloy elements constituting the zinc-based plated film, in the electrolytic solution is lower than the concentration of the alloy elements in the plating solution, when the zinc-based plated film is a zinc-alloy plated film.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for producing a zinc-based plating film and a plating apparatus for carrying out the method.

[0002] In this specification, "zinc-based plating" is a general term for zinc plating and zinc plating. Furthermore, "zinc alloy plating" refers to plating consisting of zinc, alloying elements, and unavoidable impurities. Zinc alloy plating may have a higher zinc concentration (mass%) than the concentrations (mass%) of any other alloying elements, or may contain alloying elements with a higher concentration (mass%) than that of zinc. [Background technology]

[0003] Zinc-based plating films, such as zinc alloy plating films and zinc plating films, including zinc alloy plating films such as zinc-nickel alloy, zinc-iron alloy, and tin-zinc alloy, are widely used in everyday materials, including steel sheets for automobiles and machine parts made of steel such as bolts and nuts, to improve functionality such as corrosion resistance and heat resistance.

[0004] A zinc-based plating film is formed by electroplating, in which electrolysis is performed while the member to be plated is immersed in a plating solution for forming the zinc-based plating film (also referred to as a "zinc-based plating bath" in this specification). Zinc-based plating baths are broadly classified into alkaline baths (e.g., Patent Document 1) and acidic baths (e.g., Patent Document 2). Alkaline baths include cyanide baths and zincate zinc alloy plating baths, while acidic baths include zinc chloride baths and zinc sulfate baths. An appropriate bath is selected from these zinc-based plating baths, taking into consideration various conditions such as the desired hardness and brightness of the zinc-based plating film, the shape and size of the member to be plated, and the working environment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 1-298192 [Patent Document 2] Patent No. 4307810 Summary of the Invention [Problem to be solved by the invention]

[0006] In zinc-based plating using an alkaline zinc-based plating bath, zinc is dissolved in an alkaline liquid and supplied to the plating solution as zincate ions. This tends to increase the concentration of alkaline components (substances that contribute to increasing the pH of aqueous liquids, such as sodium ions and potassium ions) used to dissolve zinc in the plating solution. If the concentration of these components in the plating solution increases, the stability of the plating solution may decrease, and it may become difficult to maintain the quality of the resulting zinc-based plating.

[0007] In addition, alkaline zinc alloy plating baths typically have lower current efficiencies than other zinc alloy plating baths, especially acidic zinc alloy plating baths. This is because a complexing agent with a high complex stability constant must be used to simultaneously dissolve zinc and alloying metals such as iron in a highly alkaline bath, which makes electrolytic deposition less likely to occur. Furthermore, when the alloying metal in a zinc alloy plating film is more noble than zinc, the alloying metal may precipitate on a zinc-containing metal ingot, making it difficult for the zinc to dissolve from the metal ingot.

[0008] An object of the present invention is to provide a method for stably producing a zinc-based plating film using an alkaline zinc-based plating bath, and to provide a plating apparatus capable of stably producing an alkaline zinc-based plating film. [Means for solving the problem]

[0009] The present invention, which is provided to solve the above problems, is as follows. (1) A method for producing a zinc-based plating film, comprising dissolving a metal ingot containing zinc in an alkaline electrolyte containing a component obtained by dialysis of an alkaline plating solution, and adding the electrolyte containing the dissolved metal ingot containing zinc to the plating solution. (2) The method for producing a zinc-based plating film according to (1) above, wherein the dialysis is electrodialysis. (3) The method for producing a zinc-based plating film according to (2) above, wherein the power supply for the electrodialysis and the power supply for plating are carried out independently. (4) The method for producing a zinc-based plating film according to (2) above, wherein the power supply for the electrodialysis is common to the power supply for plating. (5) The method for producing a zinc-based plating film according to any one of (1) to (4) above, wherein the zinc-containing metal ingot is not dissolved in the plating solution. (6) The method for producing a zinc-based plating film according to any one of (1) to (4), wherein the zinc-based plating film is a zinc alloy plating film, and the concentration of alloying elements of the zinc alloy plating film in the electrolytic solution is lower than the concentration of the alloying elements in the plating solution. (7) The method for producing a zinc-based plating film according to (6) above, wherein the zinc alloy plating film contains one or more elements selected from the group consisting of iron, nickel, and tin as the alloying element. (8) A plating apparatus for producing a zinc-based plating film using an alkaline plating solution, comprising: a plating tank containing the plating solution therein; a first insoluble anode in contact with the plating solution inside the plating tank; a conductive holder capable of holding a member to be plated; a second insoluble anode in contact with the plating solution inside the plating tank; a cathode in contact with an alkaline electrolytic solution; a power source that applies a positive voltage to the first insoluble anode and the second insoluble anode and a negative voltage to the holder and the cathode; and a power source that contains the cathode and the electrolytic solution therein. a first liquid transfer unit that transfers a portion of the electrolytic solution in the electrolytic solution to the plating tank; an ion exchange membrane that is provided in the liquid contact unit and that allows a portion of the plating solution in the plating tank to pass into the electrolytic solution; a dissolving tank that accommodates a metal ingot containing zinc and the electrolytic solution; a first liquid transfer unit that transfers a portion of the electrolytic solution in the electrolytic tank to the dissolving tank; and a second liquid transfer unit that transfers a portion of the electrolytic solution in the dissolving tank to the plating tank. (9) The plating apparatus according to (8) above, wherein the ion exchange membrane is more permeable to monovalent ions than to polyvalent ions. (10) The plating apparatus according to (8) or (9), wherein the ion exchange membrane is more permeable to cations than to anions. (11) The plating apparatus according to (8) above, wherein the ion exchange membrane is located between the second insoluble anode and the cathode. (12) The plating apparatus described in (8) above, wherein the power source has a first power source electrically connected to the first insoluble anode and the holder, and a second power source electrically connected to the second insoluble anode and the cathode. (13) The plating apparatus described in (8) above, wherein the power source includes a first power source that supplies power to a first electrolytic system including the first insoluble anode and the holder, and a second power source that supplies power to a second electrolytic system including the second insoluble anode and the cathode. (14) The plating apparatus according to (8) above, wherein either the first insoluble anode and the cathode are electrically connected by wiring, or the second insoluble anode and the holder are electrically connected by wiring. (15) The plating apparatus according to (8) above, wherein a first electrolysis system including the first insoluble anode and the holder and a second electrolysis system including the second insoluble anode and the cathode are connected in series. (16) The plating apparatus according to (8) above, wherein the plating tank has a first plating tank containing the plating solution in contact with the first insoluble anode and a second plating tank containing the plating solution in contact with the second insoluble anode, and further comprises a third liquid delivery unit that transfers a portion of the plating solution in the first plating tank to the second plating tank, and the second liquid delivery unit transfers a portion of the electrolytic solution in the dissolution tank to the first plating tank. (17) The plating apparatus according to (8) above, wherein the plating solution in the plating tank is not supplied to the dissolution tank. (18) The plating apparatus according to (8), wherein the zinc-based plating film is a zinc alloy plating film, and the concentration of the alloy elements of the zinc alloy plating film in the electrolytic solution is lower than the concentration of the alloy elements in the plating solution. (19) The plating apparatus according to (18) above, wherein the zinc alloy plating film contains one or more elements selected from the group consisting of iron, nickel, and tin as the alloying element. [Effects of the Invention]

[0010] The present invention provides a method for stably producing a zinc-based plating film using an alkaline zinc-based plating bath. Furthermore, by using the plating apparatus according to the present invention, it is possible to stably produce a zinc-based plating film from an alkaline zinc-based plating bath. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an explanatory diagram showing the configuration of a plating apparatus according to a first embodiment of the present invention. [Figure 2]FIG. 2 is a cross-sectional view taken along line AA' in FIG. [Figure 3] FIG. 4 is an explanatory view showing the configuration of a plating apparatus according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB′ in FIG. 3. [Figure 5] FIG. 10 is an explanatory view showing the configuration of a plating apparatus according to a third embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along line CC' in FIG. 5. [Figure 7] FIG. 10 is an explanatory view showing the configuration of a plating apparatus according to a fourth embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along line DD' in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below with reference to the drawings.

[0013] (First embodiment) Fig. 1 is an explanatory diagram showing the configuration of a plating apparatus according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view taken along line A-A' in Fig. 1. In Fig. 2, end A of the A-A' cross-sectional line is shown on the left side, and end A' is shown on the right side.

[0014] As shown in FIG. 1, the plating apparatus according to the first embodiment of the present invention includes a plating tank 10, an electrolytic tank 20, and a dissolving tank 30. The plating tank 10 contains an alkaline plating solution PS used to form a zinc alloy plating film, which is an example of a zinc-based plating film. The electrolytic tank 20 contains an alkaline electrolyte ES used to recover alkaline components from the plating solution PS. The dissolving tank 30 contains a zinc-containing metal ingot MI and a dissolving solution SS for dissolving the metal ingot MI. In FIG. 1, the metal ingot MI is held by a mesh (not shown) and floats in the dissolving solution SS.

[0015] A member to be plated 51 held by a conductive holder 50 and a first insoluble anode 40 are in contact with the plating solution PS inside the plating tank 10. The first insoluble anode 40 is connected to the positive terminal of a first power source 81, and the holder 50 is connected to the negative terminal of the first power source 81. In the plating apparatus 100 shown in FIG. 1, two first insoluble anodes 40 are arranged to sandwich the member to be plated 51. In use, a zinc alloy plating film is deposited on the member to be plated 51 by supplying power from the first power source 81 to a first electrolysis system including the holder 50, the member to be plated 51 held by the holder 50, and the first insoluble anode 40.

[0016] A second insoluble anode 60, which is different from first insoluble anode 40, is also in contact with the plating solution PS inside plating tank 10. Electrolytic tank 20 accommodates a cathode 70 and an electrolytic solution ES therein. Therefore, cathode 70 is in contact with the electrolytic solution ES inside electrolytic tank 20. An opening 10A is provided in a part of the side surface of plating tank 10, and this opening 10A allows at least a part of the outer surface of electrolytic tank 20 to come into contact with the plating solution PS inside plating tank 10 as liquid contact part 22.

[0017] The liquid contact part 22 is provided with an ion exchange membrane 23 that allows a portion of the plating solution PS in the plating tank 10 to permeate into the interior of the electrolytic tank 20. The ion exchange membrane 23 is disposed so as to be located between the second insoluble anode 60 in contact with the plating solution PS and the cathode 70 in contact with the electrolytic solution ES. Thus, the plating apparatus 100 according to this embodiment includes an electrolytic tank 20 that accommodates the cathode 70 and the electrolytic solution ES therein, and is provided with an electrolysis part 21 that comes into contact with the plating solution PS in the plating tank 10 at the liquid contact part 22 that is provided to include at least a portion of the outer surface of the electrolytic tank 20.

[0018] The second insoluble anode 60 is connected to the positive terminal of a second power source 82, and the cathode 70 is connected to the negative terminal of the second power source 82. During use, power is supplied from the second power source 82 to the second electrolysis system including the second insoluble anode 60 and the cathode 70, thereby performing electrodialysis in which a portion of the plating solution PS moves into the electrolyte solution ES through the ion exchange membrane 23. Specifically, alkaline components such as sodium ions and potassium ions are dialyzed and move from the plating solution PS to the electrolyte solution ES.

[0019] As shown in FIG. 2, power is supplied from a second power source 82 to the second insoluble anode 60 and the cathode 70, which face each other through the ion exchange membrane 23. Therefore, the substances that permeate the ion exchange membrane 23 are cationic substances that move from the plating solution PS to the electrolyte solution ES, and are anionic substances that move from the electrolyte solution ES to the plating solution PS.

[0020] In the plating apparatus 100 according to this embodiment, the ion exchange membrane 23 is a cationic ion exchange membrane, which allows cations to pass through it more easily than anions. This prevents anionic substances from moving from the electrolyte solution ES to the plating solution PS, and the amount of substances moving from the plating solution PS to the electrolyte solution ES tends to be greater than the amount of substances moving from the electrolyte solution ES to the plating solution PS. Therefore, the liquid level of the electrolyte solution ES in the electrolytic bath 20 is higher than the liquid level of the plating solution PS in the plating bath 10. In FIG. 2, the liquid levels of the solutions in each bath (plating solution PS, electrolyte solution ES, and dissolving solution SS) are indicated by two-dot chain lines. Thus, in this embodiment, the ion exchange membrane 23 also functions to transport liquid from the plating bath 10 to the electrolytic bath 20. A specific example of the cationic ion exchange membrane 23 is the "Neocepta CMB" manufactured by Astom Corporation.

[0021] As described above, the alkaline component comprising part of the plating solution PS is supplied to the electrolytic bath 20, causing the liquid level of the electrolytic solution ES to rise. In the plating apparatus 100 according to this embodiment, an overflow mechanism is provided as a first liquid supply unit 91 that transfers part of the electrolytic solution ES inside the electrolytic bath 20 to the dissolution bath 30. This maintains the amount of the electrolytic solution ES inside the electrolytic bath 20 at a predetermined level, and part of the electrolytic solution ES inside the electrolytic bath 20 is continuously supplied to the dissolution bath 30.

[0022] The alkaline electrolyte ES supplied into the dissolving tank 30 dissolves the metal ingot MI inside the dissolving tank 30. A second liquid supply unit 92 consisting of an overflow mechanism is provided between the dissolving tank 30 and the plating tank 10, so that a portion of the solution SS containing dissolved matter of the metal ingot MI (specifically, ions containing zinc, such as zincate ions, are exemplified) is continuously supplied to the plating tank 10.

[0023] As described above, in this embodiment, the alkaline plating solution PS located inside the plating tank 10 is dialyzed by the second electrolysis system, and the alkaline component is transferred to the electrolytic tank 20. The alkaline electrolyte solution ES containing the alkaline component obtained by this dialysis is supplied to the dissolving tank 30, whereby the zinc-containing metal ingot MI is dissolved inside the dissolving tank 30. Then, the solution SS, which is the electrolyte solution ES containing the dissolved metal ingot MI, is added to the plating solution PS inside the plating tank 10.

[0024] When adding the solution SS obtained by dissolving a zinc-containing metal ingot MI in an alkaline liquid to the plating solution PS, if the alkaline component that dissolves the metal ingot MI is supplied from an external source other than the plating solution PS, the concentration of ions based on the alkaline component in the plating solution PS (specifically, sodium ions and potassium ions are examples) increases over time, disrupting the compositional balance of the plating solution PS and reducing the stability of the plating solution PS. A decrease in the stability of the plating solution PS can also lead to a decrease in the quality of the plating film.

[0025] In contrast, as described above, in the zinc alloy plating manufacturing method using the plating apparatus 100 according to this embodiment, the metal ingot MI is dissolved by the alkaline components of the plating solution PS, so even if plating is performed for a long period of time, the alkaline components inside the plating solution PS are unlikely to increase, and therefore the balance of the plating solution PS is unlikely to be disturbed.

[0026] Here, the ion exchange membrane 23 provided in the plating apparatus 100 according to this embodiment allows monovalent ions to pass through more easily than multivalent ions, so that multivalent metal ions (specifically, iron ions, tin ions, and nickel ions) contained in the plating solution PS that provide alloying elements for the zinc alloy plating film are less likely to migrate to the electrolytic bath 20. Therefore, the concentration of multivalent metal ions originating from the plating solution PS in the solution SS is low, and even if an alloying element of the zinc alloy plating film, such as iron, is more noble than zinc, the concentration of that alloying element in the solution SS is particularly low. Thus, in the plating apparatus 100 according to this embodiment, the concentration of alloying elements for the zinc alloy plating film in the electrolytic solution ES is lower than the concentration of alloying elements in the plating solution PS, so displacement plating (precipitation of alloying elements on the metal ingot MI), which is problematic when a zinc-containing metal ingot MI is dissolved in the plating solution PS, is less likely to occur.

[0027] (Second embodiment) Fig. 3 is an explanatory diagram showing the configuration of a plating apparatus according to a second embodiment of the present invention. Fig. 4 is a cross-sectional view taken along line B-B' in Fig. 3. In Fig. 4, the end B side of the B-B' cross-sectional line is shown on the left side, and the end B' side is shown on the right side.

[0028] The plating apparatus 110 according to the second embodiment has a basic configuration in common with the plating apparatus 100 according to the first embodiment, so only the differences will be described. In the plating apparatus 100 according to the first embodiment, an opening 10A is provided in a portion of the plating tank 10, and the portion of the electrolytic tank 20 facing through this opening 10A constitutes the liquid-contacting portion 22. In contrast, in the plating apparatus 110 according to the second embodiment, the electrolytic tank 20 is provided so that a portion of the electrolytic tank 20 is submerged in the plating solution PS inside the plating tank 10. That is, in the plating apparatus 110 according to the second embodiment, portions of all side surfaces and the bottom surface of the electrolytic tank 20 constitute the liquid-contacting portion 22 that contacts the plating solution PS. In addition, in the plating apparatus 110, an ion exchange membrane 23 is provided on each of a pair of opposing side surfaces of the electrolytic tank 20, and two second insoluble anodes 60 are provided in the plating tank 10 so as to face the two ion exchange membranes 23 of the electrolytic tank 20, respectively. Note that the two second insoluble anodes 60 are connected in parallel to the positive terminal of the second power source 82, and therefore an equal positive voltage is applied to the two second insoluble anodes 60 during use.

[0029] In the plating apparatus 100 according to the first embodiment, the first liquid delivery section 91, which moves a portion of the electrolytic solution ES inside the electrolytic cell 20 to the dissolution tank 30, is composed of an overflow mechanism, whereas in the plating apparatus 110 according to the second embodiment, the first liquid delivery section 91 is composed of a liquid delivery pump.

[0030] In the first embodiment, the second electrolysis system including the ion exchange membrane 23 served as the driving source for the liquid circulation in the plating apparatus 100, but to achieve this, it is necessary to maintain the liquid level of the electrolytic solution ES higher than the liquid level of the plating solution PS. Therefore, in the plating apparatus 100 according to the first embodiment, the second electrolysis system must perform mass transfer against a force that tries to lower the liquid level of the electrolytic solution ES to the level of the plating solution PS.

[0031] In contrast, in the second embodiment, the liquid supply pump constituting the first liquid supply unit 91 continuously transfers the electrolyte solution ES to the dissolution tank 30, so that the liquid level of the electrolyte solution ES is lower than the liquid level of the plating solution PS, as shown in Fig. 4. Based on this difference in liquid level, mass transfer from the plating solution PS to the electrolyte solution ES occurs more easily than mass transfer in the opposite direction in the ion exchange membrane 23. Therefore, in the second embodiment, the second electrolysis system recovers the alkaline component of the plating solution PS into the electrolyte solution ES more efficiently than the second electrolysis system of the first embodiment.

[0032] In this embodiment, since the electrolytic cell 20 is located inside the plating cell 10, it is possible to use a commercially available cylindrical or box-shaped diaphragm electrode. One example of such a commercially available diaphragm electrode is "TECTORON" manufactured by POLYTEX CORPORATION.

[0033] (Third embodiment) Fig. 5 is an explanatory diagram showing the configuration of a plating apparatus according to a third embodiment of the present invention. Fig. 6 is a cross-sectional view taken along line CC' in Fig. 5. In Fig. 6, the end C side of the CC' cross-sectional line is shown on the left side, and the end C' side is shown on the right side.

[0034] The plating apparatus 120 according to the third embodiment has a basic configuration in common with the plating apparatus 110 according to the second embodiment, so only the differences will be described.

[0035] The plating apparatus 110 according to the second embodiment uses a single plating tank 10, with the first electrolysis system powered by a first power source 81 and the second electrolysis system powered by a second power source 82, whereas the plating apparatus 120 according to the third embodiment uses two plating tanks (first plating tank 11 and second plating tank 12), with the first and second electrolysis systems connected in series and powered by a single power source 80. A third liquid supply unit 93 consisting of an overflow mechanism is provided between the first plating tank 11 and the second plating tank 12, so that a portion of the plating solution PS in the first plating tank 11 is continuously supplied to the second plating tank 12.

[0036] Specifically, in the plating apparatus 120 according to the third embodiment, a first electrolysis system is disposed in the first plating tank 11, a second insoluble anode 60 constituting a second electrolysis system is disposed in the second plating tank 12, and the plating solution PS contained in the first plating tank 11 and the plating solution PS contained in the second plating tank 12 are electrically independent. The second insoluble anode 60 constituting the second electrolysis system is connected to the positive terminal of the power source 80, and the holder 50 constituting the first electrolysis system is connected to the negative terminal of the power source 80, and the cathode 70 of the second electrolysis system and the first insoluble anode 40 of the first electrolysis system are electrically connected, thereby connecting the first electrolysis system and the second electrolysis system in series.

[0037] This configuration may allow for a single power source, thereby reducing the manufacturing cost of the device. However, in this case, the amount of current flowing through the first electrolysis system and the amount of current flowing through the second electrolysis system are equal. Therefore, when the plating device 120 is in operation, the area of ​​the member to be plated 51 held by the holder 50 changes, which changes the amount of alkaline component in the plating solution PS that moves into the electrolytic bath 20. Since the amount of electrolyte solution ES in the electrolytic bath 20 changes depending on this change in the amount of alkaline component, it may be necessary to adjust the amount of electrolyte solution ES transferred to the dissolution bath 30 by the first solution transfer unit 91.

[0038] (Fourth embodiment) Fig. 7 is an explanatory diagram showing the configuration of a plating apparatus according to a fourth embodiment of the present invention. Fig. 8 is a cross-sectional view taken along line DD' in Fig. 7. In Fig. 8, the end D side of the DD' cross-sectional line is shown on the left side, and the end D' side is shown on the right side.

[0039] The plating apparatus 130 according to the fourth embodiment has a basic configuration in common with the plating apparatus 120 according to the third embodiment, so only the differences will be described.

[0040] In the plating apparatus 120 according to the third embodiment, the electrolytic cell 20 is disposed inside the plating tank 10, as in the second embodiment, but in the plating apparatus 130 according to the fourth embodiment, the electrolytic cell 20 is disposed outside the second plating tank 12, as in the first embodiment, and the first liquid delivery unit 91 is configured with an overflow mechanism. The plating apparatus 130 according to the fourth embodiment has a single power source and does not use a liquid delivery pump, which may enable the manufacturing costs to be kept low.

[0041] The above-described embodiments are provided to facilitate understanding of the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments are intended to encompass all design modifications and equivalents within the technical scope of the present invention. For example, in the above-described embodiment, the plating solution PS contained in the plating tank 10 is a zinc alloy plating solution (zinc alloy plating bath) for forming a zinc alloy plating film. However, it may be a zinc plating solution (zinc plating bath) for forming a zinc plating film. Even in this case, the alkaline component that dissolves the zinc-containing metal ingot MI in the dissolving solution SS in the dissolving tank 30 originates from the plating solution PS. Therefore, the alkaline component concentration of the plating solution PS is unlikely to increase, and the compositional balance of the plating solution PS is unlikely to be disrupted even during long-term plating. [Example]

[0042] The effects of the present invention will be explained below based on examples, but the present invention is not limited to these.

[0043] A plating test was carried out using the plating apparatus 110 according to the second embodiment. The liquid volume and current of each tank were as follows: Plating solution PS in plating tank 10: 40L Electrolyte ES in electrolytic cell 20: 1L Dissolving solution SS in dissolving tank 30: 2L Applied current (plating current) of first power supply 81: 5A Applied current of second power supply 82 (dialysis current): 10 A

[0044] The electrolyte ES in the electrolytic cell 20 was an aqueous solution of sodium hydroxide. As the ion exchange membrane 23, "Neocepta CMB" manufactured by Astom Co., Ltd., which has an ion exchange resin, was used.

[0045] The zinc concentration (zinc ion concentration) and sodium concentration (sodium ion concentration) of the liquid inside each tank (plating solution PS, electrolyte solution ES, dissolving solution SS) were measured initially before the start of energization, and 40 and 80 hours after the start of energization. The results are shown in Table 1. The numbers in the table indicate concentration (unit: g / L) (the same applies below).

[0046] [Table 1]

[0047] As shown in Table 1, in this example, the zinc concentration in the plating solution PS in the plating tank 10 did not change even after 80 hours. Furthermore, the sodium concentration in the plating solution PS in the plating tank 10 was measured after 40 hours, slightly lower than the initial value of 70 g / L to 65 g / L, and remained the same after 80 hours. Thus, in this example, the composition of the plating solution PS in the plating tank 10 was able to remain essentially the same after 80 hours from the time of bath make-up. The sodium concentrations in the electrolytic solution ES in the electrolytic tank 20 and the solution SS in the dissolving tank 30 increased compared to the initial values ​​(at the time of bath make-up) due to the plating process. Therefore, it was confirmed that the zinc concentration in the solution SS increased over time as the zinc ingot dissolved.

[0048] (Comparative Example 1) Using a plating apparatus having only a plating tank, plating was carried out using plating solution PS with the same composition as in Example 1 under the same conditions as in Example 1 (plating current: 5 A), and measurements were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0049] [Table 2]

[0050] As shown in Table 2, the zinc concentration of the plating solution PS in the plating tank decreased over time, reaching 3 g / L after 80 hours.

[0051] (Comparative Example 2) Using the plating apparatus of Comparative Example 1, the same plating solution PS as in the Example was prepared, and plating was carried out under the same conditions as in the Example (plating current: 5 A). However, in Comparative Example 2, plating was carried out while periodically replenishing a replenisher solution (zinc concentration: 150 g / L, sodium hydroxide concentration: 450 g / L). The measurement results of the zinc and sodium concentrations of the plating solution PS inside the plating tank are shown in Table 3.

[0052] [Table 3]

[0053] As shown in Table 3, in Comparative Example 2, unlike Comparative Example 1, no decrease in the zinc concentration was observed in the plating solution PS inside the plating tank 10. However, because plating was performed while replenishing a replenisher solution containing sodium hydroxide, the sodium concentration in the plating solution PS inside the plating tank 10 increased over time. This resulted in a decrease in the stability of the plating solution PS. [Explanation of symbols]

[0054] 100, 110, 120, 130: Plating equipment 10: Plating tank 10A:Aperture 11: First plating tank 12: Second plating tank 20: Electrolytic cell 21: Electrolytic section 22: Wetted part 23: Ion exchange membrane 30:Dissolution tank 40: First insoluble anode 50: Holder 51: Plated material 60: Second insoluble anode 70: Cathode 80: Power supply 81: 1st power supply 82:Second power supply 91: First liquid delivery section 92: Second liquid delivery section 93: Third liquid delivery section ES: Electrolyte MI: Metal ingot PS: Plating solution SS:Solution solution

Claims

1. A method for manufacturing a zinc-containing metal ingot by dialyzing an alkaline plating solution through a cationic ion exchange membrane that is more permeable to monovalent ions than polyvalent ions, thereby transferring alkaline components from the plating solution to an electrolyte, and dissolving a zinc-containing metal ingot in the alkaline electrolyte. adding the electrolyte solution containing the zinc-containing metal ingot melt to the plating solution; A method for producing a zinc-based plating film, characterized by:

2. The method for producing a zinc-based plating film according to claim 1 , wherein the dialysis is electrodialysis.

3. The method for producing a zinc-based plating film according to claim 2, wherein the power supply for the electrodialysis and the power supply for the plating are carried out independently.

4. The method for producing a zinc-based plating film according to claim 2 , wherein power supply for the electrodialysis is performed in common with power supply for plating.

5. The method for producing a zinc-based plating film according to claim 1 , wherein the zinc-containing metal ingot is not dissolved in the plating solution.

6. 5. The method for producing a zinc-based plating film according to claim 1, wherein the zinc-based plating film is a zinc alloy plating film, and a concentration of an alloy element of the zinc alloy plating film in the electrolytic solution is lower than a concentration of the alloy element in the plating solution.

7. 7. The method for producing a zinc-based plating film according to claim 6, wherein the zinc alloy plating film contains one or more elements selected from the group consisting of iron, nickel, and tin as the alloying elements.

8. A plating apparatus for producing a zinc-based plating film using an alkaline plating solution, a plating tank containing the plating solution therein; a first insoluble anode in contact with the plating solution inside the plating tank; a holder capable of holding a member to be plated and having conductivity; a second insoluble anode in contact with the plating solution inside the plating tank; a cathode in contact with an alkaline electrolyte; a power source that applies a positive voltage to the first insoluble anode and the second insoluble anode and applies a negative voltage to the holder and the cathode; an electrolysis unit having an electrolytic cell that accommodates the cathode and the electrolytic solution therein, the electrolysis unit contacting the plating solution inside the plating cell at a liquid contact part that is provided to include at least a part of the outer surface of the electrolytic cell; an ion exchange membrane provided in the liquid contact portion, which allows a portion of the plating solution in the plating tank to permeate into the electrolytic tank; a melting tank containing a zinc-containing metal ingot and the electrolyte; a first liquid delivery unit that transfers a portion of the electrolytic solution in the electrolytic cell to the dissolution tank; a second liquid transport unit configured to transport a portion of the electrolytic solution into the plating tank; Equipped with The plating apparatus is characterized in that the ion exchange membrane is more permeable to monovalent ions than to polyvalent ions, and more permeable to cations than to anions.

9. The plating apparatus according to claim 8 , wherein the ion exchange membrane is located between the second insoluble anode and the cathode.

10. The power supply a first power source electrically connected to the first insoluble anode and the holder; a second power source electrically connected to the second insoluble anode and the cathode; The plating apparatus according to claim 8 , further comprising:

11. The power supply a first power source that supplies power to a first electrolysis system including the first insoluble anode and the holder; a second power source that supplies power to a second electrolysis system including the second insoluble anode and the cathode; The plating apparatus according to claim 8 , further comprising:

12. 9. The plating apparatus according to claim 8, wherein either the first insoluble anode and the cathode are electrically connected by wiring, or the second insoluble anode and the holder are electrically connected by wiring.

13. 9. The plating apparatus according to claim 8, wherein a first electrolytic system including the first insoluble anode and the holder and a second electrolytic system including the second insoluble anode and the cathode are connected in series.

14. The plating bath is a first plating tank containing the plating solution in contact with the first insoluble anode; a second plating tank containing the plating solution in contact with the second insoluble anode; and a third solution delivery unit that transfers a portion of the plating solution in the first plating tank to the second plating tank, The plating apparatus according to claim 8 , wherein the second liquid delivery unit delivers a portion of the electrolytic solution in the dissolution tank to the first plating tank.

15. The plating apparatus according to claim 8 , wherein the plating solution in the plating tank is not supplied to the inside of the dissolving tank.

16. 9. The plating apparatus according to claim 8, wherein the zinc-based plating film is a zinc alloy plating film, and the concentration of alloy elements of the zinc alloy plating film in the electrolytic solution is lower than the concentration of the alloy elements in the plating solution.

17. 17. The plating apparatus according to claim 16, wherein the zinc alloy plating film contains one or more elements selected from the group consisting of iron, nickel, and tin as the alloying elements.

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