TWI818057B - Electrode for electrolytic plating - Google Patents

Abstract

The object of the present invention is to provide an electrode for an electrolytic plating, the electrode having an effect of a suppressed depletion of catalyst provided therein. There is thus provided an electrode for an electrolytic plating, comprising an electrode base, a catalyst layer provided over the electrode base, and a protective layer provided over the catalyst layer. The electrode of the present invention is characterized in that a surface area of the electrode with the protective layer being provided therein is smaller than a surface area of the electrode with no protective layer being provided therein.

Description

Electrodes for electrolytic plating

The present invention relates to electrodes for electrolytic plating. More specifically, the present invention relates to electrodes used for electrolysis in electroplating methods.

Electrolytic plating is still widely used in industry. For example, techniques for producing metal foils by electrolytic plating are known. Such electrolytic plating can also be called electrical casting (especially "electroforming"). Electroforming can produce metal foil relatively simply and continuously, and it is relatively easy to control metal foil characteristics such as surface smoothness, so it is mostly used to produce metal foil such as copper foil.

The production of metal foil by electrolytic plating utilizes the principle of electrolytic plating and uses electrodes. For example, as shown in FIG. 8 , an electrode 520 immersed in the electrolytic solution 510 of the electrolytic cell 500 and a cylindrical counter electrode 530 paired therewith are used. The electrolytic plating electrode 520 is disposed facing the cylindrical counter electrode 530 and used. When electricity is passed between the electrolytic plating electrode 520 and the cylindrical counter electrode 530, the metal component can be electrolytically deposited on the surface of the counter electrode 530. Therefore, the metal foil 550 can be continuously produced by energizing the cylindrical counter electrode 530 while rotating the counter electrode 520, and then sequentially peeling off the metal layer formed by electrolysis from the counter electrode 530. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 6-47758 [Patent Document 2] Japanese Patent No. 3278492 [Patent Document 3] Japanese Patent Publication No. 2016-503464 [Patent Document 4] Japanese Patent No. 3832645

[Problem to be solved by the invention]

The inventor of the present application found that the electrodes previously used for electrolytic plating still had problems that should be overcome, and discovered the necessity of adopting countermeasures to overcome the problems. Specifically, the inventor of the present application discovered the following problems.

When producing metal foil by electrolytic plating, an insoluble electrode is generally used as the electrode facing the cylindrical electrode. In particular, an insoluble anode placed opposite a cylindrical cathode is used. The reaction of the insoluble anode generally produces an oxidation reaction of water, that is, an oxygen generation reaction. Although the chlorine generation reaction may also occur depending on the components of the electrolyte, the oxygen generation reaction is the main reaction. Therefore, catalysts with high oxygen generation activity are often used for such electrodes for electrolytic plating.

On the other hand, additives are often added to the electrolyte solution used to produce metal foil by electrolytic plating. For example, additives are added from the viewpoint of surface smoothness and/or glossiness of the electrolytic metal foil. Although such additives are ideal for producing the desired metal foil, they are sometimes not necessarily ideal for electrodes with catalysts.

Specifically, the inventor of the present application found that the additives contained in the electrolyte for manufacturing metal foil by electrolytic plating are one of the reasons for promoting catalyst consumption, so the electrode catalyst decreases with the manufacturing of metal foil (please refer to Figure 7) .

The present invention was made in view of this situation. That is, the main object of the present invention is to provide an electrode for electrolytic plating that suppresses catalyst consumption. [Methods to solve problems]

The inventor of this application does not deal with the extension of the conventional technology, but attempts to solve the above problems by dealing with it in a new direction. As a result, an electrode for electrolytic plating that achieves the above-mentioned main object was invented.

The invention provides an electrode for electrolytic plating, which has: electrode substrate; A catalyst layer is provided on the aforementioned electrode substrate; and A protective layer is provided on the aforementioned catalyst layer, The surface area of the electrode with the aforementioned protective layer is relatively smaller than the surface area of the electrode without the protective layer. [Efficacy of the invention]

The electrode of the present invention is an electrode for electrolytic plating that suppresses catalyst consumption.

Specifically, the electrode of the present invention can more effectively suppress the consumption of the catalyst layer during electrolytic plating because the surface area of the electrode with the protective layer is relatively smaller than the surface area of the electrode without the protective layer.

Hereinafter, the electrode for electrolytic plating of the present invention will be described in detail. Although description is made with reference to the drawings as necessary, the contents shown in the drawings are merely schematically and exemplarily shown for understanding the present invention, and the appearance, dimensional ratio, etc. may be different from the actual thing.

The "cross-sectional view" used directly or indirectly when explaining the present invention corresponds to a cross-sectional view taken along the thickness direction of the electrode, and is essentially equivalent to a view of the object taken from the side. Obviously, the "cross-sectional view" can be equivalent to the view taken in the form shown in Figure 1 and so on. In addition, matters related to the "upper" and "lower" directions used directly or indirectly in relation to the electrodes for electrolytic plating also obviously depend on the forms shown in Figure 1 and so on.

Unless otherwise specified, the various numerical ranges mentioned in this specification are intended to include the lower and upper limits. That is, taking the numerical range of 1 to 10 as an example, unless otherwise specified, it can be interpreted as including the lower limit value "1" and the upper limit value "10".

"Electrode of the Invention" The electrode of the present invention is an electrode used for electrolytic plating. Electrolytic plating is used for manufacturing, for example, metal foils, etc., or for anti-rust plating, steel plate plating, etc. In particular, in the former case, the electrode of the present invention may be called an electrode for electrolytic metal foil manufacturing. The term "electrolytic metal foil" used herein refers to metal foil produced by electrolytic plating. Examples of the electrolytic metal foil include at least one metal foil selected from the group consisting of copper, nickel, and iron. As a typical example, the electrolytic metal foil can be copper foil (or copper alloy foil).

As shown in FIG. 1 , the electrode 100 for electrolytic plating (for example, for electrolytic metal foil production) of the present invention is used so as to face a cylindrical counter electrode 200 . In preferred metal foil manufacturing, the electrode 100 of the present invention serves as the "anode" and on the other hand the counter electrode 200 serves as the "cathode". When producing electrolytic metal foil, by passing electricity between the anode and cathode electrodes, a metal foil (more specifically, a metal layer that forms a precursor to the metal foil) can be formed on the cathode due to electrolytic precipitation. The electrode 100 used as such an anode is preferably a so-called insoluble anode. In the case of an insoluble anode, the metal component is not supplied by dissolving the anode electrode, but the components originally contained in the electrolyte of the electrolytic cell become the supply source of the metal component for electroplating.

The counter electrode serving as the cathode has a cylindrical shape as a whole and is rotatably provided. Here, "cylindrical shape" means that the counter electrode has a cylindrical shape or a substantially cylindrical shape that facilitates continuous production of metal foil. In addition, the electrode of the present invention serving as the anode is arranged to be separated from the cylindrical cathode and surround a part thereof during use.

The electrode for electrolytic plating of the present invention has a layered structure. Therefore, the electrode of the present invention at least has an electrode base material, a catalyst layer and a protective layer. Specifically, as shown in FIG. 1 , a catalytic layer 30 is provided relative to the electrode base material 10 forming the main body portion of the electrode, and a protective layer 50 is provided on the catalytic layer 30 . As can be seen from the illustrated aspect, in the electrode 100 of the present invention, the electrode base material 10, the catalytic layer 30 and the protective layer 50 are arranged to be stacked in layers.

The electrode base material 10 contributes to the conduction of electricity during electrolytic plating. For example, the electrode base material 10 contributes to the conduction of electricity during the production of electrolytic metal foil, and is a portion that has an actual function as an anode during electroforming. The electrode base material 10 forms the main body part of the electrode 100 for electrolytic plating. The material of the electrode substrate 10 is not particularly limited, but may be a valve metal. In more detail, the electrode substrate may include at least one metal selected from the group consisting of: tantalum, niobium, titanium, hafnium, zirconium, tungsten, bismuth, and antimony. Although this is only an example, from the viewpoint of corrosion resistance and/or versatility, according to a preferred embodiment, the electrode base material 10 includes titanium or a titanium alloy. The thickness (average thickness) of the electrode base material is not particularly limited, but may be, for example, about 0.5 mm to 30 mm.

In addition, when referred to as an "electrode base material", the electrode of the present invention may form a component separate from the electrolytic cell. This means that the electrode substrate and electrolytic cell are separated from each other. At this time, electrodes (such as most plate-shaped electrodes) are installed on the electrolytic tank during electrolytic plating. Alternatively, the electrode of the present invention may be integrated with the electrolytic cell. This means that the electrolytic cell itself essentially forms the electrode substrate. Although this is only an example, in the case of "integration", an electrolytic cell curved to face a cylindrical counter electrode with a predetermined interval is used, and the catalyst layer and the protective layer are formed on the curved surface of the electrolytic cell.

The catalyst layer 30 is provided on the electrode base material 10 . Another different layer may be inserted between the catalyst layer 30 and the electrode substrate 10 as an intermediate layer. Alternatively, the catalyst layer 30 can be directly disposed on the surface of the electrode substrate 10 . When the electrode 100 of the present invention is used as an insoluble anode when manufacturing electrolytic metal foil by electrolytic plating, the reaction of the electrode is mainly an oxygen generation reaction. Therefore, the catalyst layer 30 may include a catalyst component that is highly active in generating oxygen. For example, a catalyst containing a platinum group metal or its oxide may be coated. That is, the catalyst layer 30 provided on the electrode substrate 10 may include at least one platinum group metal and/or the platinum selected from the group consisting of: iridium, ruthenium, platinum, palladium, rhodium and osmium. Oxides of group metals. In addition, the catalyst layer 30 may contain metal components other than platinum group metals and/or oxides thereof, or may additionally contain metal components such as Group 5 elements. Although it is just an example, in the electrode according to a certain preferred aspect of the present invention, the catalyst layer 30 may contain iridium (Ir) or may contain tantalum (Ta). The thickness (average thickness) of the catalyst layer is not particularly limited, but may be, for example, about 1 μm to 20 μm.

The protective layer 50 is provided on the catalyst layer 30 . Preferably, the protective layer 50 is directly disposed on the surface of the catalyst layer 30 of the electrode substrate 10 . As shown in FIG. 1 , the catalyst layer 30 is preferably present through the protective layer 50 so as not to directly contact the electrolyte. The protective layer 50 provided in the electrode of the present invention is equivalent to the layer mainly used to protect the catalyst layer 30. That is, the term "protective layer" in this specification refers in a broad sense to a layer that protects a catalyst used to manufacture an electrode for electrolytic metal foil by electrolytic plating, and in a narrow sense refers to a layer that protects an electrode catalyst (especially an anode catalyst) from Affected by the additives contained in the electrolyte used to produce electrolytic metal foils by electrolytic plating.

Additives that improve the properties of the produced metal foil are usually added to the electrolyte solution used to produce electrolytic metal foil by electrolytic plating. For example, when copper foil used for printed circuit materials and/or battery current collectors is manufactured by electroforming, from the viewpoint of improving the surface smoothness and/or glossiness of the copper foil, it is often used in the electrolyte. Add additives. That is, from the viewpoint of improving characteristics such as surface smoothness and/or glossiness of the produced electrolytic copper foil, additives are often added to the electrolyte containing the copper sulfate aqueous solution. Although this is merely an example, such an additive may be at least one selected from the group consisting of saccharin, gelatin, gelatin, thiourea, and PEG. The inventor of the present application found that although additives are ideal for producing the desired metal foil, they become a factor that promotes consumption of the electrode base material and in the long term promotes the electrode catalyst layer (especially the anode when producing electrolytic metal foil). of catalyst layer). Therefore, in order to suppress such inappropriate promotion reduction, the electrode of the present invention is provided with a protective layer on the catalyst layer.

In the electrode 100 for electrolytic plating (for example, for electrolytic metal foil production) of the present invention, the protective layer 50 preferably contains a transition metal. That is, the protective layer 50 provided on the catalyst layer 30 should preferably contain a transition element metal. This is because the protective layer 50 containing the transition metal ideally helps protect the catalyst layer.

Among transition metals, metals of Group 5 elements are particularly good. That is, the protective layer 50 preferably contains a metal of Group 5 elements. In other words, the protective layer 50 disposed on the catalyst layer 30 should preferably include a vanadium group metal. This is because the protective layer 50 containing such a vanadium group, that is, a Group 5 element, more ideally contributes to protecting the catalyst layer. For example, the protective layer 50 contains tantalum (Ta), and in an electrode according to a preferred aspect of the present invention, the protective layer 50 is formed of only tantalum (Ta) (that is, the protective layer can have a Ta content rate of 100%). .

In addition, from another perspective, the material of the protective layer 50 of the present invention is preferably different from the material of the electrode base material 10 . In the electrode according to a preferred aspect of the present invention, the protective layer 50 is made of tantalum (Ta) only or a combination of tantalum (Ta) and iridium (Ir). On the other hand, the electrode base material 10 is made of titanium or titanium alloy.

Here, in the present invention, the surface area of the electrode having the protective layer is a singular point. Specifically, in the electrode for electrolytic plating (for example, for electrolytic metal foil production) of the present invention, the surface area of the electrode with a protective layer is relatively smaller than the surface area of the electrode without a protective layer. This means that for electrodes used for electrolytic plating (for example, for the production of electrolytic metal foils), when comparing the surface of the electrode with a protective layer and the surface of the electrode without a protective layer, the surface area of the former is smaller than the surface area of the latter. Furthermore, this means that the surface area of the electrode (especially the top surface of the electrode) can be reduced by providing a protective layer.

Specifically, in a preferred aspect, the surface area of the electrode with the protective layer is as small as about 20% to 90% of the surface area of the electrode without the protective layer. That is, the relationship between _{the surface area Sa of the electrode with a protective layer and the surface area S b of the electrode without a protective layer satisfies the condition of 0.2×S b ≦ S a} ≦0.9×S _b . An electrode having a protective layer with such surface area characteristics can ideally produce the protective effect of the catalyst layer as described in the embodiments described later. In this regard, in the process of intensively examining electrodes for electrolytic plating that suppress catalyst consumption, the inventors of the present application found that the surface area of the electrode with a protective layer is closely related to the cause of catalyst consumption (see "Catalyst" in the Examples described later). Relative comparison of consumption speed"). In particular, it was found that the surface area of the electrode with the protective layer that achieves the effect of suppressing catalyst consumption is smaller than the surface area of the electrode without the protective layer. The catalyst consumption rate V _a of an electrode with a protective layer having a relatively small surface area is, for example, 20% to 90% of the catalyst consumption rate V _b of an electrode without such a protective layer. More specifically, although the catalyst consumption rate V _a of "with a protective layer" may differ depending on the baking temperature when the protective layer is formed and the composition of the protective layer, etc., it can be the catalyst consumption rate V of "without a protective layer" 20% to 85% of _b , for example, may be 20% to 30% of V _b , 35% to 45% of V _b , 70% to 80% of V _b or 75% to 85% of V _b , etc.

In the present invention, although the surface area of the electrode with the protective layer is preferably as small as about 20% to 90% of the surface area of the electrode without the protective layer, it is more preferable that the surface area of the electrode with the protective layer is as small as without the protective layer. about 25% to 85% of the surface area of the electrode. Therefore, _{the relationship between the surface area Sa of the electrode with a protective layer and the surface area S b of the electrode without a protective layer better satisfies 0.25×S b ≦ S a} ≦0.85× S _b conditions. Although it may vary depending on the baking temperature and the composition of the protective layer when forming the protective layer, for another example, the relationship between the surface area Sa of the electrode with a protective _layer and the surface area S _b of the electrode without a protective layer can be It is the condition of 0.25×S _b ≦S _a ≦0.35×S _b or the condition of 0.75×S _b ≦S _a ≦0.85×S _b . In particular, the former means that by providing a protective layer, the surface area of the electrode is reduced to approximately 1/4 compared to an electrode without a protective layer.

As far as the electrode of the present invention is concerned, the "relatively small surface area of the electrode with a protective layer" refers to the surface area and specific surface area that can be obtained through electrochemical measurements, or particularly through electrostatic capacitance measurements of the electrical double layer. Therefore, "the relatively small surface area of the electrode with the protective layer" can be calculated based on cyclic voltammetry (CV: Cyclic Voltammetry), or the surface area and specific surface area can be calculated based on the cyclic voltammogram.

In cyclic voltammetry, when the electrode potential is scanned and the surface area is calculated based on the electrostatic capacity determined by measuring the response current (please refer to Figure 2), among the electrodes of the present invention, the surface area of the electrode with a protective layer is as small as without protection. approximately 20% to 90% of the surface area of the electrode of the layer. That is, in terms of the surface area and specific surface area obtained by cyclic voltammetry, the electrode with a protective layer is about 20% to 90% smaller than the electrode without a protective layer.

The term "specific surface area based on cyclic voltammetry" in the present invention means that it is determined by the electrochemical measurement manual "Basic Edition" (9th edition, Maruzen Co., Ltd., edited by the Denkiskai Society, pp. 37 to 44). The surface area obtained by CV measurement is explained. More specifically, the "specific surface area based on cyclic voltammetry" in the present invention refers to the surface area obtained using the measuring device of AUTOMATIC POLARIZATION SYSTEM HSV-110 (Hokuto Electric Co., Ltd.) . The measurement steps (evaluation method) and measurement conditions of the measurement device are described in detail below. Measurement procedures (evaluation methods) (1) First, assemble the measurement unit as shown in Figure 2. (2) Next, connect the terminals of HSV-110 to the working electrode, counter electrode and reference electrode. (3) Perform pre-treatment of the working electrode. (4) Measure at a predetermined scanning speed. Measurement conditions ‧Temperature when measuring: room temperature (about 25℃) ‧Electrolyte: 0.5M sulfuric acid aqueous solution ‧Working electrode: any one of the inventive electrode ("electrode with protective layer") and comparison electrode ("electrode without protective layer") (electrolysis area 10mm × 10mm) ‧Counter electrode: platinum plate (25mm×25mm) ‧Reference electrode: silver silver chloride electrode ‧Pretreatment conditions: 10 cycles at a scanning speed of 100mV/s in the range of 0.5 to 1.0V (for Ag/AgCl). ‧Measurement conditions: 3 cycles at a scanning speed of 10mV/s in the range of 0.5 to 1.0V (for Ag/AgCl).

The surface area S _b of the electrode without a protective layer is described in detail below. The electrode that does not have a protective layer as the object of this surface area may be an electrode before the protective layer is formed. That is, the electrode used for surface area measurement may be the electrode before the protective layer of the electrode precursor of the present invention is formed.

As can be seen from the above description, the "electrode without a protective layer" in the present invention means an electrode having a structure in which only the protective layer is removed from the electrode for electrolytic plating of the present invention. Therefore, in a preferred aspect, the "electrode without protective layer" is an electrode composed of an electrode base material and a catalytic layer provided on the electrode base material, and is an electrode in which the catalytic layer is provided as the outermost layer. In addition, such an electrode may have a structure having an "intermediate layer" described below. Therefore, an "electrode without a protective layer" has a catalyst layer as the outermost layer and additionally has an intermediate layer between the catalyst layer and the electrode base material. of electrodes.

In addition, in the present invention, the surface area S _b of the electrode without a protective layer may be the surface area of an electrode for electrolytic plating (for example, MD-100 or MD-160 manufactured by DAISO ENGINEERING Co., Ltd.) for convenience. When the electrode (for example, MD-100 or MD-160) is a commercially available electrode for electrolytic plating, it can be equivalent to the electrode of the precursor in terms of having a catalyst layer provided on the electrode base material, etc. The surface area of the electrode can be regarded as the "surface area S _b " of the present invention.

The electrode for electrolytic plating of the present invention can be embodied in various forms. For example, the following aspects may be considered.

(top protective layer) In this electrode aspect, the protective layer has the form of a topcoat layer. That is, the protective layer 50 forms the uppermost layer in the electrode 100 as shown in FIG. 1 . This means that when the metal foil is manufactured by electrolytic plating, the protective layer is in direct contact with the electrolyte, and in the presence of the protective layer, it directly functions to protect the catalyst layer relative to the electrolyte.

Since the uppermost layer is formed, the protective layer is exposed and no additional layer or the like is provided on the protective layer. In the present invention, the electrode with such a protective layer is preferably as small as about 20% to 90% of the surface area of the electrode without the protective layer.

(Protective layer in film form) In this aspect, the protective layer has a film form. That is, the layer used to protect the catalyst layer is not thick and can at least contribute to weight reduction of the electrode for electrolytic plating.

Specifically, the protective layer has an average thickness of, for example, 15 μm or less. Even with such a protective layer in the form of a film of 15 μm or less, the electrode of the present invention can achieve the effect of suppressing catalyst consumption when manufacturing electrolytic metal foil. The average thickness of the protective layer is preferably 10 μm or less, and more preferably 8 μm or less. On the other hand, the lower limit of the average thickness of the protective layer may be, for example, 4 μm, or may be 3 μm, 2 μm, or 1 μm. Therefore, the average thickness of the protective layer is preferably 1 μm to 10 μm, for example, 1 μm to 8 μm, 2 μm to 10 μm, 2 μm to 8 μm, 3 μm to 10 μm, 3 μm to 8 μm, 4 μm to 10 μm, or 4 μm to 8 μm.

The "average thickness of the protective layer" as used in this specification refers to any 10 points in the cross-sectional view of the protective layer based on a microscope photo or image such as an SEM image (for example, a cross-sectional image taken with JSM-IT500HR, manufactured by JEOL) Average (additive average). Furthermore, such "average" thickness details apply equally to other layers.

(Electrode laminate structure with intermediate layer) In this aspect, the laminate structure of the electrodes additionally has an intermediate layer. Specifically, as shown in FIG. 3 , the electrode 100 for electrolytic metal foil manufacturing further has an intermediate layer 60 between the electrode base material 10 and the catalyst layer 30 .

Although not particularly limited, the presence of the intermediate layer can achieve the effect of improving the protective properties of the electrode base material or improving the adhesion strength of the catalyst layer to the electrode base material. As can be seen from the aspects shown in the figures, the "middle" of the "intermediate layer" is based on the fact that the layer is provided between the part forming the electrode base material and the catalyst part.

Although merely illustrative, the average thickness of the intermediate layer may be approximately 5 μm to 20 μm. In addition, the material of the middle layer may be tantalum or the like or include titanium.

(Compound component form of protective layer) In this aspect, the protective layer is not made of a single material, but is made of multiple components. As mentioned above, when the protective layer preferably contains a transition metal, the protective layer may contain at least two kinds of metals as the transition metal. In this way, the protective layer can easily exert more ideal protective properties.

In a preferred aspect, the two metals are a metal of platinum group elements and a metal of elements other than platinum group elements. For example, it may be a metal of Group 5 elements and a metal of Platinum group elements. That is, the protective layer contains metals of both platinum group elements and elements other than platinum group elements, and preferably contains metal components of both platinum group elements and group 5 elements. At this time, it is preferable that there are relatively more metals other than platinum group elements than metals of platinum group elements. This is because metals other than the platinum group have low activity as electrode catalysts and do not produce electrochemical reactions. For example, the content of metals other than platinum group elements (such as Group 5 element metals) in the protective layer is 50% by weight (excluding 50% by weight) to 98% by weight, preferably 60% by weight to 98% by weight, and more preferably 70% to 98% by weight, for example, 80% to 98% by weight. In contrast, the platinum group element metal content may be 2% to 50% by weight, preferably 2% to 40% by weight, more preferably It is 2 to 30% by weight, for example, 2 to 20% by weight.

As the composite component contained in the protective layer, the Group 5 element may be tantalum (Ta) and the Platinum group element may be Iridium (Ir). That is, the protective layer may be a combination of tantalum (Ta) which is a group 5 element and iridium (Ir) which is a platinum group element, or a composite component of such a transition metal. To give a more specific example, for example, in a protective layer containing tantalum (Ta) and iridium (Ir) as the main components, the content of the tantalum (Ta) component is 50% by weight (excluding 50% by weight) to 98% by weight. Preferably it is 60% to 98% by weight, more preferably 70% to 98% by weight, for example, 80% to 98% by weight. In contrast, the content of the iridium (Ir) component may be 2% to 50% by weight. % by weight, preferably 2% to 40% by weight, more preferably 2% to 30% by weight, for example, 2% to 20% by weight.

Hereinafter, in order to better understand the present invention, "a method for manufacturing an electrode for electrolytic plating" and "a manufacturing apparatus for electrolytic metal foil using an electrode for electrolytic plating" will be described.

"Manufacturing method of electrodes for electrolytic plating" The electrode for electrolytic plating of the present invention can be produced by forming a catalyst layer on an electrode base material to prepare an electrode with a catalyst layer, and then providing a protective layer on the catalyst layer.

The catalytic layer can be formed by any method as long as it can be disposed on the electrode substrate. As an example, the catalyst layer can be formed by baking. Specifically, the catalytic layer can be formed by applying a raw material liquid corresponding to the precursor of the catalytic layer on the electrode base material, drying it, and then applying baking. The coating, drying, and baking can be performed in the same manner as the protective layer formation described in detail below. In addition, a commercially available electrode for electrolytic plating (eg, for electrolytic metal foil) can be used as the electrode having the catalytic layer. For example, as an electrode having a catalytic layer, electrodes with product numbers MD-100 or MD-160 manufactured by DAISO ENGINEERING Co., Ltd. can be used.

Next, the protective layer is formed. However, the protective layer can be formed by any method as long as it can be disposed on the catalyst layer of the electrode. As an example, the protective layer may be formed by baking.

Specifically, the protective layer can be formed by applying a raw material liquid corresponding to the precursor of the protective layer on the catalyst layer, drying it, and then baking it. Although the raw material liquid is only an example, it contains at least a transition metal, an organic solvent and/or a solvent such as water that dissolves the transition metal. The transition metal is a metal of the above-mentioned Group 5 elements, for example, tantalum (Ta). In addition, metals of platinum group elements may be further included as transition metals in the raw material liquid, for example, a combination of tantalum (Ta) and iridium (Ir) may be included. Organic solvents are not particularly limited, but can be used individually: methanol, ethanol, propanol (n-propanol, isopropanol), butanol (n-butanol, isobutanol, secondary butanol and tertiary butanol) Alcohols such as methyl ethyl ketone, methyl isobutyl ketone (MIBK), etc.; terpines including α-terpineol, β-terpineol, and γ-terpineol; ethylene glycol Alcohol monoalkyl ethers; ethylene glycol dialkyl ethers; diethylene glycol monoalkyl ethers; diethylene glycol dialkyl ethers; ethylene glycol monoalkyl ether acetate; ethylene glycol dialkyl ether acetate Class; diethylene glycol monoalkyl ether acetate; diethylene glycol dialkyl ether acetate; propylene glycol monoalkyl ether; propylene glycol dialkyl ether; propylene glycol monoalkyl ether acetate. In addition, optional A mixture formed from at least one or two or more solvents among these solvents. In addition, additives (for example, inorganic acids, etc.) may be added to the raw material liquid of the protective layer, although this is only an example.

The coating of the protective layer precursor is not limited, but can be carried out by spraying, brushing, dipping, etc. The protective layer precursor coated on the catalyst layer is dried to reduce the solvent through vaporization of the solvent. Therefore, the coated protective layer precursor may be dried at high temperature or the coated protective layer precursor may be placed under reduced pressure or vacuum. When drying at high temperature is applied, it is suitable to apply the coated protective layer precursor at a drying temperature of about 80 to 200°C (an example is 100 to 150°C) under atmospheric pressure for about 2 to 40 minutes. In addition, when placed under reduced pressure or vacuum, it is preferable, for example, to place the coated protective layer precursor under reduced pressure or vacuum of 7 to 0.1 Pa. You can also combine "under reduced pressure or vacuum" and "heat treatment" as needed. In a more specific example of application under drying temperature conditions, drying of the coated protective layer precursor can be performed by using an appropriate dryer (eg, Datong Industrial Laboratory, explosion-proof dryer, DBO3-450, etc.). After such drying is applied, baking is applied to the protective layer precursor. The baking temperature is preferably 300°C to 600°C and more preferably 350°C to 550°C. The baking time is not particularly limited, but is preferably about 5 to 90 minutes and more preferably about 10 to 60 minutes. In a more specific example, baking can be performed by using an appropriate oven (for example, an electric oven, a gas oven, an infrared oven, etc.). Through the above coating, drying and baking, the desired protective layer is finally obtained.

In addition, coating, drying, and baking are not limited to one time, but may be performed more than once. Therefore, the thickness of the protective layer can be appropriately adjusted. Although this is only an example, the process of coating, drying, and baking can be performed, for example, about 2 to 10 times.

"Electrolytic metal foil manufacturing equipment using electrodes for electrolytic plating" An apparatus for manufacturing electrolytic metal foil using the electrode of the present invention has the electrode 100 of the present invention as an anode and a cylindrical counter electrode 200 as a cathode (please refer to FIG. 1 ).

In a device for electrolyzing metal foil, the desired separation distance between the anode and the cathode (the distance between the proximate surfaces of the two electrodes) is, for example, approximately 5 to 25 mm. The electrode of the present invention used as an anode is installed to face the cathode, and on the other hand, a cylindrical counter electrode is rotatably provided as the cathode. That is, the cathode is formed into a rotating drum and placed in the electrolytic cell. Specifically, approximately the lower half of the rotating drum of the cathode is disposed so as to be immersed in the electrolyte of the electrolytic cell (that is, the plating solution). The cylindrical cathode itself may be one conventionally used in the manufacture of electrolytic metal foils. During the manufacture of metal foil, the cathode cylinder is rotated and electroplating is performed while the cathode cylinder is in contact with the electrolyte. Due to the rotation of the cylinder, a part of the cathode cylinder that is in contact with the electrolyte is exposed to the air, but at this time the electroplated layer is mechanically peeled off from the surface of the cylinder. In this way, the desired metal foil can be obtained. Since the metal foil is produced continuously, a suitable reel device for winding the metal foil can be provided.

The electrolytic metal foil device also has a busbar for supplying power to the electrodes. For example, the busbar may be mounted on the electrode substrate and/or the support base 150 of the electrode. With such a busbar, direct current can flow between the anode and the cathode, so that the desired electroforming can be performed. In addition, the support base or the like may have a supply port (for example, a gap portion) that facilitates supply of the electrolyte. Through this supply port, consumed electroplating components can be appropriately replenished.

Although various aspects of the present invention have been described above, it should be understood that the present invention is not limited thereto, and various aspects can be implemented by those with ordinary skill in the art without departing from the scope of the invention specified in the patent application.

Furthermore, it is confirmed that the present invention as described above includes the following aspects. Aspect 1: An electrode for electrolytic plating, comprising: an electrode base material; a catalyst layer provided on the aforementioned electrode base material; and a protective layer provided on the aforementioned catalyst layer, and the surface area of the electrode having the aforementioned protective layer is equal to The surface area is relatively smaller than that of an electrode without a protective layer. Second aspect: An electrode for electrolytic plating, in the first aspect, the relationship between the surface area S _a of the electrode having the aforementioned protective layer and the surface area S _b of the electrode not having the aforementioned protective layer satisfies 0.2×S _b ≦ S The condition of _a ≦0.9×S _b . A third aspect: an electrode for electrolytic plating, in the first aspect or the second aspect, the surface area is a specific surface area based on cyclic voltammetry. A fourth aspect: an electrode for electrolytic plating, in any one of the above-mentioned first to third aspects, wherein the protective layer forms an uppermost layer in the electrode. A fifth aspect: an electrode for electrolytic plating, in any one of the above-described first to fourth aspects, wherein the electrode corresponds to an anode for electrolytic plating. A sixth aspect: an electrode for electrolytic plating, in any one of the above-described first to fifth aspects, wherein the protective layer contains a transition metal. A seventh aspect: an electrode for electrolytic plating, in the above-mentioned sixth aspect, the transition metal is a metal of a Group 5 element. An eighth aspect: an electrode for electrolytic plating, in the above-mentioned sixth or seventh aspect, wherein the protective layer contains tantalum. A ninth aspect: an electrode for electrolytic plating in the sixth aspect, wherein the protective layer contains at least two kinds of metals as the transition metals. A tenth aspect: an electrode for electrolytic plating, in the ninth aspect, the two metals are a metal of Group 5 elements and a metal of Platinum group elements. An eleventh aspect: an electrode for electrolytic plating, in any one of the above-mentioned first to tenth aspects, wherein the catalyst layer contains a metal of a platinum group element. A twelfth aspect: An electrode for electrolytic plating, in any one of the above-described first to eleventh aspects, wherein the electrode base material contains a valve metal. A 13th aspect: an electrode for electrolytic plating, in any one of the above-mentioned 1st to 12th aspects, further having an intermediate layer between the electrode base material and the catalyst layer. [Example]

Various empirical tests related to the present invention were carried out.

"Relative comparison of catalyst consumption speed" In order to confirm the influence of additives in the electrolyte and the protective layer effect of the present invention, an electrolysis test was carried out.

Specifically, an electrolysis test simulating the production of electrolytic metal foil was conducted based on Examples 1 to 4 and Comparative Example 1 and "the "additive-free" condition of the electrolyte", and then the catalyst consumption speed was compared.

●Example 1 An electrolysis test was conducted using the following test electrodes. Test electrode (anode for electrolytic metal foil manufacturing) ‧Electrode laminate structure: (lower side) electrode base material/intermediate layer/catalyst layer/protective layer (upper side) ‧Electrode base material: valve metal (titanium) Thickness: 1 to 3mm ‧Intermediate layer material: tantalum Thickness: 5 to 10μm ‧Catalyst layer material: platinum group metal (iridium) Thickness: 5 to 20μm ‧Protective layer material: iridium and tantalum (weight ratio of Ir:Ta: 5:95) (Iridium component: Tokyo Chemical Industry Co., Ltd., Tantalum component: Tokyo Chemical Industry Co., Ltd.) Thickness: 5 to 10 μm Solvent of raw material liquid (protective layer precursor): Butanol (Tokyo Chemical Industry Co., Ltd.) Drying temperature after coating of raw material liquid: 120 ℃ Baking temperature after drying: 400℃ ‧The preparation method of the protective layer is a laminated structure with an electrode base material/intermediate layer/catalyst layer (a laminated structure in which a catalyst layer is provided on the electrode base material by inserting an intermediate layer) A protective layer is formed as a top coat by applying a raw material liquid of a protective layer precursor to a commercially available electrolytic metal foil electrode (manufactured by DAISO ENGINEERING Co., Ltd., product number: MD-160), drying and baking. Repeat the series of coating, drying and baking procedures 5 to 10 times until the predetermined thickness is obtained. Electrolysis test conditions ‧Opposite electrode (cathode): platinum plate (10mm×10mm) ‧Reference electrode: silver silver chloride electrode ‧Current density: 100A/dm ² ‧Electrolysis temperature: 80℃ ‧Electrolyte: 20 wt% H ₂ SO ₄ and 10% by weight Na ₂ SO ₄ ‧Additive: saccharin (Tokyo Chemical Industry Co., Ltd.) 1000ppm ‧The catalyst consumption rate is determined by the initial catalyst amount W _after deducting "the catalyst after electrolysis for a certain period of time (T: 300 hours)" _{After the amount W is electrolyzed} , the specific consumption rate V of the catalyst layer of the electrode is calculated by dividing it by the time T. The calculation formula is as follows. In addition, the "initial catalyst amount W _{initial stage} " and the "catalyst amount after electrolysis W _{after electrolysis} " were determined respectively by fluorescence X-ray analysis (handheld fluorescence X-ray analyzer MESA Portable manufactured by Horiba Manufacturing Co., Ltd.). V=(W _{initial stage} -W _{after electrolysis} )/T ●Example 2 Except that the baking temperature condition of the protective layer was set to "490°C", the electrode was produced under the same conditions as in Example 1 and the same electrolysis test was performed. ●Example 3 Except that the material condition of the protective layer was set to "tantalum 100%", the electrode was produced under the same conditions as in Example 1 and the same electrolysis test was conducted. ●Example 4 Except that the material condition of the protective layer is set to "tantalum 100%" and the baking temperature condition of the protective layer is set to "490°C", the electrode is produced under the same conditions as in Example 1 and the same electrolysis is performed. Experiment. ●Comparative Example 1 (without protective layer) The same electrolysis test was conducted using electrodes under the same conditions as in Example 1, except that no protective layer was provided. More specifically, an electrolysis test was performed on the electrode of DAISO ENGINEERING Co., Ltd., product number: MD-160. ● "Additive-free" condition of the electrolyte solution. The same electrolysis test as in Comparative Example 1 was performed except that the electrolyte solution did not contain additives.

The test results are shown in Figure 4. The following things can be understood from the diagram in Figure 4. ‧The additives used in the electrolyte promote the consumption of the catalyst layer of the electrode. ‧The protective layer helps protect the catalyst layer. ‧Specifically, the catalyst consumption speed is reduced by providing a protective layer and the catalyst consumption is suppressed by the protective layer.

"Confirmation test of protective layer characteristics" In order to confirm the characteristics of the protective layer that suppresses catalyst consumption, tests were conducted. In particular, the inventor of the present application learned through the above-mentioned experiments that the surface characteristics of the electrode surface (top surface) are possible, that is, the surface characteristics of the electrode with a protective layer are different from those of the electrode without a protective layer, and confirmed it. Test of surface area of electrodes.

Specifically, the following cyclic voltammetry was performed to relatively compare the surface areas of electrode A, electrode B, and electrode C. ‧Electrode A: The electrode used in "Comparative Example 1 (without protective layer)" ‧Electrode B: The electrode used in "Example 2" ‧Electrode C: The electrode used in "Example 1" Cyclic voltammetry (CV) AUTOMATIC POLARIZATION SYSTEM HSV-110 (Hokuto Electric Co., Ltd.) was used as the CV measurement device. Measurement procedures (evaluation methods) (1) First, assemble the measurement unit as shown in Figure 2. (2) Next, connect the terminals of HSV-110 to the working electrode, counter electrode and reference electrode. (3) Perform pre-treatment of the working electrode. (4) Measure at a predetermined scanning speed. Measurement conditions ‧Temperature when measuring: room temperature (about 25℃) ‧Electrolyte: 0.5M sulfuric acid aqueous solution ‧Working electrode: each of the above-mentioned electrode A, electrode B and electrode C (electrolysis area 10mm×10mm) ‧Counter electrode: platinum plate (25mm×25mm) ‧Reference electrode: silver silver chloride electrode ‧Pretreatment conditions: 10 cycles at a scanning speed of 100mV/s in the range of 0.5 to 1.0V (for Ag/AgCl). ‧Measurement conditions: 3 cycles at a scanning speed of 10mV/s in the range of 0.5 to 1.0V (for Ag/AgCl).

The results are shown in Figures 5 and 6. The following matters can be understood from the diagrams in Figures 5 and 6. ‧The surface area of the electrode with a protective layer is relatively smaller than the surface area of the electrode without a protective layer. ‧Specifically, the surface area of the electrode with a protective layer is as small as 20% to 90% of the surface area of the electrode without a protective layer.

Based on the above-mentioned "relative comparison of catalyst consumption speed" and "confirmation test of protective layer characteristics", it can be seen that the electrolytic plating electrode provided with a protective layer on the catalyst layer can suppress the catalyst consumption when manufacturing electrolytic metal foil. effect, and the surface area of the electrode with the protective layer that contributes to such suppressive effect has a relatively smaller surface area than the surface area of the electrode without the protective layer.

The electrode of the present invention can be used in various fields where electrolytic plating is performed. It is ideally used in electroforming for manufacturing electrolytic metal foils. Although this is merely an example, the electrode of the present invention can be preferably used as an anode in a device for manufacturing an electrolytic metal foil used in a printed circuit material or an electrode current collector of a secondary battery.

10:Electrode substrate 30:Catalyst layer 50:Protective layer 60:Middle layer 100, 520: Electrode 150:Matrix 200, 530: Counter electrode 500:Electrolyzer 510:Electrolyte 550:Metal foil

[Fig. 1] is a schematic cross-sectional view showing the laminate structure of the electrode for electrolytic plating of the present invention. [Figure 2] is a schematic diagram and principle formula used to illustrate cyclic voltammetry. [Fig. 3] is a schematic cross-sectional view for explaining the "electrode laminate structure having an intermediate layer". [Figure 4] is a graph showing the results of "relative comparison of catalyst consumption speeds". [Figure 5] is a cyclic voltammogram obtained through the "confirmation test of protective layer characteristics". [Figure 6] is a graph showing the results (relative comparison of surface areas) of the "confirmation test of protective layer characteristics". [Fig. 7] is a schematic cross-sectional view showing the reduction of the electrode catalyst along with the production of electrolytic metal foil. [Fig. 8] is a schematic cross-sectional view illustrating a method of manufacturing a continuous metal foil by electrolytic plating.

10:Electrode substrate

30:Catalyst layer

50:Protective layer

100:Electrode

150:Matrix

200: Counter electrode

Claims (4)

An electrode for electrolytic plating, comprising: an electrode base material; a catalyst layer disposed on the electrode base material; and a protective layer disposed on the catalyst layer. The surface area of the electrode with the protective layer is compared with that without protection. The surface area of the electrode of the protective layer has a relatively small surface area; the relationship between the surface area Sa of the electrode with the protective layer and _{the surface area S b of the electrode without the protective layer satisfies the condition of 0.2×S b ≦ S a} ≦0.9×S _b ; The surface area is based on the specific surface area of cyclic voltammetry; there is an intermediate layer between the electrode base material and the catalyst layer; the protective layer forms the uppermost layer in the electrode for electrolytic plating and contains iridium and tantalum. For example, it is the electrode for electrolytic plating in item 1 of the patent scope, wherein the electrode is equivalent to the anode for electrolytic plating. For example, in the electrode for electrolytic plating of claim 1, the catalyst layer contains a metal of platinum group elements. For example, the electrode for electrolytic plating in claim 1, wherein the electrode base material includes a valve metal.