Anode for electroplating and method and system for electroplating an object with a metal

Abstract

The present invention provides an anode for electroplating, which does not require an auxiliary device and an anode liquid management, and can be easily manufactured without using expensive metals and special metals. The present invention relates to an anode for electroplating, comprising: an input portion for inputting electric power from a power source; a pair of support portions extending in a first direction, arranged at intervals from each other in a second direction intersecting the first direction, receiving supply of electric power from the input portion, and covered with an insulating material at a liquid-contacting portion with a plating liquid; and a current-carrying portion extending in the second direction, one end of which is connected to one of the pair of support portions, the other end of which is connected to the other of the pair of support portions, and receiving supply of electric power from the pair of support portions; the current-carrying portion having a plurality of current paths arranged at intervals from each other in the first direction, and a cross-sectional area of the current-carrying portion being smaller than a cross-sectional area of the support portions.

Description

TECHNICAL FIELD

[0001] The present application relates to an anode for electroplating and a method and system for electroplating an article with metal using the same, and particularly relates to an anode for electroplating in which decomposition of an organic compound additive added to a plating bath containing metal ions is inhibited and a method and system for electroplating an article with metal using the same. BACKGROUND

[0002] Zinc plating is used as a comparatively inexpensive rustproof plating layer, and in its alkaline plating bath, an organic compound such as a quaternary ammonium polymer is used as an additive. If this organic compound is decomposed by anodic oxidation, it causes poor adhesion dendrites to be precipitated, and a good rustproof zinc plating layer cannot be formed.

[0003] Since zinc alloy plating has excellent corrosion resistance compared with zinc plating, it is widely used in automobile parts and the like. In particular, an alkaline zinc-nickel alloy plating bath is used in fuel parts requiring high corrosion resistance, and engine parts placed in a high temperature environment. The alkaline zinc-nickel alloy plating bath is one in which nickel is dissolved using an amine chelating agent suitable for the desired eutectoid ratio of nickel, and zinc and nickel are eutectoidized on the plated film. However, when current is passed, there is a problem in that the amine chelating agent is oxidized and decomposed on the anode surface to produce oxalic acid and sodium carbonate. In the presence of iron ions and the like, iron-based metal ions, they act as oxidation catalysts, and further promote the oxidation and decomposition of the amine chelating agent. Thus, by bringing the alkaline zinc-nickel alloy plating bath into contact with the anode, the amine chelating agent is rapidly decomposed, and the plating performance rapidly deteriorates. As a result of the accumulation of the decomposition products, there are many problems such as a decrease in current efficiency, an increase in bath voltage, a decrease in plating film thickness, a decrease in the eutectoid ratio of nickel in the plated film, a narrowing of the range of current density that can be plated, a decrease in gloss, an increase in chemical oxygen demand (COD), and the like. Therefore, the plating bath cannot be used for a long period of time, and must be frequently replaced.

[0004] Patent Documents 1 and 2 describe a so-called anode cell system in which an anode solution is put in a cell covered with a diaphragm, and the plating bath is separated from contact with the anode plate, whereby decomposition of the organic compound additive can be inhibited. In this anode cell system, since oxalic acid and sodium carbonate produced in the plating bath move from the plating solution into the anode cell, an effect of removing the decomposition products from the plating bath is also expected. On the other hand, the anode cell system requires a plurality of auxiliary equipment such as an anode cell main body, piping, and a pump. Furthermore, the concentration of the anode solution needs to be managed, and the anode solution needs to be renewed every certain amount of current passed.

[0005] Patent Document 3 describes that decomposition of the organic compound additive is inhibited by performing coating on the surface of the conductive substrate of the anode. In this case, no auxiliary equipment or electrode solution management is required, but the cost for manufacturing the anode becomes a problem. Patent Document 4 also describes performing coating on the surface of the conductive substrate of the anode, but further improvement is required.

[0006] On the other hand, Patent Literature 5 describes that an electrode in which an iridium oxide-based coating layer is provided on a conductive substrate is used for iron-based plating at a specific anode current density, thereby suppressing the oxidation of Fe ions in the plating bath 2+ the coating layer can be net-shaped. In addition, Patent Literature 6 describes a porous metal anode in the shape of a draw net metal having a coating layer of an electrode active material such as iridium oxide, and describes that the electrode is not only lightweight and easy to handle compared to a conventional flat plate anode, but also that gas generated is easily dissipated and effective for the decrease in voltage, and the like.

[0007] Prior Art Documents

[0008] Patent Literature

[0009] Patent Literature 1: International Publication No. 2016 / 075963

[0010] Patent Literature 2: International Publication No. 2016 / 075964

[0011] Patent Literature 3: Japanese Patent No. 6582353

[0012] Patent Literature 4: Japanese Laid-Open Patent Publication No. 2019-530800

[0013] Patent Literature 5: Japanese Laid-Open Patent Publication No. 5-331696

[0014] Patent Literature 6: Japanese Laid-Open Patent Publication No. 1-208499 SUMMARY

[0015] An object of the present application is to provide an anode for plating that does not require auxiliary equipment and management of an anolyte, and that can be manufactured relatively easily without using an expensive metal or a special metal.

[0016] The present inventors and others have conducted intensive research in order to solve the above-described problems, and as a result, have found that in an anode for plating, by providing a specific support portion between an input portion that inputs electric current from a power source and an energization portion that energizes a plating bath, the increase in bath voltage and the increase in bath temperature due to heating of the energization portion can be suppressed, thereby completing the present application. That is, the present application provides an anode for plating, a method of plating an article with a metal, and a system of plating an article with a metal, as shown below.

[0017] 〔1〕 An anode for plating, comprising:

[0018] an input portion that inputs electric power from a power source,

[0019] a pair of support portions extending in a first direction, arranged at intervals in a second direction intersecting the first direction, receiving supply of electric power from the input portion, and having liquid-contacting portions covered with an insulating material, and

[0020] a power supply portion extending in the second direction, one end of which is connected to one of the pair of support portions and the other end of which is connected to the other of the pair of support portions, receiving supply of electric power from the pair of support portions;

[0021] the power supply portion has a plurality of current paths arranged at intervals in the first direction,

[0022] a cross-sectional area of the power supply portion is smaller than a cross-sectional area of the support portion.

[0023] 〔2〕 The anode for electroplating according to any one of the above-mentioned items 1 to 5, wherein a ratio (Sc / So) of an area (Sc) of the liquid-contacting portion of the power supply portion to an outer shape area (So) of a region in which the power supply portion is arranged is 0.05 to 0.5.

[0024] 〔3〕 The anode for electroplating according to any one of the above-mentioned items 1 to 5, wherein a ratio (S2 / S1) of a cross-sectional area (S2) of the power supply portion to a cross-sectional area (S1) of the support portion is 0.5 or less.

[0025] 〔4〕 The anode for electroplating according to any one of the above-mentioned items 1 to 5, wherein the power supply portion contains a metal wire, a stretched metal, and / or a punched metal.

[0026] 〔5〕 The anode for electroplating according to any one of the above-mentioned items 1 to 5, wherein the power supply portion

[0027] has a cross-sectional area (S2) of 3 to 75 mm 2 , and / or,

[0028] contains at least one selected from iron, nickel, stainless steel, and carbon, and / or,

[0029] is arranged in the anode uniformly and dispersedly, and / or,

[0030] is arranged at intervals of 10 cm or less from each other.

[0031] 〔6〕 The anode for electroplating according to any one of the above-mentioned items 1 to 5, wherein the support portion constitutes at least a part of an outer periphery of the anode, and / or,

[0032] a cross-sectional area (S1) of the support portion is 15 to 1200 mm 2 .

[0033] 〔7〕 A method of electroplating an article with a metal,

[0034] The process includes energizing a plating bath containing ions of the aforementioned metals and organic compound additives.

[0035] The above-mentioned plating bath has the above-mentioned article as the cathode and has the electroplating anode as described in any one of [1] to [6] above.

[0036] [8] According to the method described in [7] above, the magnitude of the current (anodic current density) relative to the area (Sc) of the liquid-contact portion of the energized part is 25 to 150 A / dm. 2 , and / or

[0037] The magnitude of the current relative to the cross-sectional area (S2) of the aforementioned energized part is 2 to 75 A / mm². 2 .

[0038] [9] A system for electroplating articles with metal,

[0039] A plating bath containing ions of the aforementioned metals and organic compound additives.

[0040] The above-mentioned plating bath has the above-mentioned article as the cathode and has the electroplating anode as described in any one of [1] to [6] above.

[0041] According to the present invention, by providing a pair of support portions with a cross-sectional area larger than that of the energized portion and whose contact portion with the plating solution is covered with an insulating material between the input portion and the energized portion of the electroplating anode, the rise in bath voltage can be suppressed. The electroplating anode of the present invention does not require auxiliary equipment or anolyte management, and also does not require expensive or special metals, thus reducing the cost of electroplating. Attached Figure Description

[0042] Figure 1 This illustrates one embodiment (ladder type) of the electroplating anode of the present invention. The shaded areas are covered with an insulating material.

[0043] Figure 2 This illustrates one embodiment (grid type) of the electroplating anode of the present invention. The shaded areas are covered with an insulating material.

[0044] Figure 3 This illustrates one embodiment (mesh type) of the electroplating anode of the present invention. The shaded areas are covered with an insulating material.

[0045] Figure 4 express Figure 3 Enlarged view of part IV.

[0046] Figure 5 The anode used for comparison in electroplating.

[0047] Figure 6 representing the plated appearance of the cathode plate. DETAILED DESCRIPTION

[0048] Hereinafter, the present application will be described in further detail.

[0049] The anode for electroplating of the present application has:

[0050] an input portion that inputs electric power from a power source,

[0051] a pair of support portions that extend in a first direction, are arranged at intervals from each other in a second direction that intersects the first direction, receive supply of electric power from the input portion, and are covered with an insulating material at a portion that contacts the plating solution, and a power transmission portion that extends in the second direction, one end of which is connected to one of the pair of support portions and the other end of which is connected to the other of the pair of support portions, and receives supply of electric power from the pair of support portions; the cross-sectional area of the power transmission portion is smaller than the cross-sectional area of the support portions. When the anode current density is increased using a conventional electrode that is simply flat, it is necessary to reduce the outer shape area of the power transmission portion or to apply a current that is larger than that required for plating. In the former case, the power transmission area in the plating bath deviates due to the reduction in the outer shape area, the current distribution becomes uneven, and the bath voltage rises. Also, heat is generated at the boundary portion between the outside air and the plating solution, and this can cause the bath voltage to rise. On the other hand, in the electrode for electroplating of the present application, the support portions supply electric power to the power transmission portion, and since the portion that contacts the plating solution is covered with an insulating material, the plating solution is not electrified, and heat generation at the boundary portion between the outside air and the plating solution and the rise in the bath voltage do not easily occur. The support portions can effectively supply electric power to the power transmission portion that is located far from the input portion, i.e., to the power transmission portion that intrudes into the deep portion of the plating solution. Also, the power transmission portion can stably receive supply of electric power even in the deep portion of the plating solution, and the entire electrode is contained in the plating solution, so even if it is composed of a conductive member with a small cross-sectional area, heat generation is not a problem, and furthermore, since the power transmission portions are arranged uniformly and dispersedly, the current distribution in the bath does not deviate. As a result, the plating solution (plating bath) can be uniformly and effectively electrified, and a good plating film can be formed on the article that is the object of electroplating. Note that the "cross-sectional area" here refers to the cross-sectional area in a plane that is orthogonal to the direction of current flow.

[0052] The first direction in which the pair of support portions extend is not particularly limited, and can be a direction extending from the input portion. Also, the second direction is not particularly limited as long as it intersects the first direction, and can be a direction orthogonal to the first direction. Also, the pair of support portions can be separate points on a continuous member, or can be points on separate members, and the specific configuration is not particularly limited as long as the pair of support portions can connect the current-carrying portion therebetween. In some embodiments, the pair of support portions can constitute at least a portion of the outer periphery of the anode, and can surround the entire outer periphery. That is, the anode for electroplating of the present application can further include an additional support portion, and the pair of support portions and the additional support portion can be directly or indirectly connected to constitute a portion or all of the outer periphery of the anode, forming a frame.

[0053] The cross-sectional area (S1) of the support portion is not particularly limited, and can be, for example, about 15 mm 2 to about 1200 mm 2 , can be about 100 mm 2 to about 1100 mm 2 , or can be about 125 mm 2 to about 1000 mm 2 . Also, the electrically conductive member constituting the support portion is not particularly limited as long as it can carry current, and can include, for example, at least one selected from iron, nickel, stainless steel, carbon, titanium, copper, and members coated with the same.

[0054] The insulating material is not particularly limited as long as it can withstand use in a plating solution, and can include, for example, at least one selected from high molecular resins, rubber, insulating inorganic oxides, insulating inorganic nitrides, insulating inorganic carbides, and insulating inorganic borides. More specifically, the high molecular resin can include epoxy resin, vinyl chloride resin, melamine resin, phenol resin, fluorine resin, acrylic resin, polystyrene, ABS (acrylonitrile-butadiene-styrene) resin, polyethylene, polypropylene, nylon, polyurethane, methyl pentene resin, or polycarbonate, and the rubber can include silicone rubber, fluorine rubber, polyurethane rubber, acrylic rubber, nitrile rubber, ethylene-propylene rubber, styrene rubber, butyl rubber, butadiene rubber, or natural rubber. The insulating inorganic oxide can include silicon dioxide, magnesium oxide, zinc oxide, beryllium oxide, titanium oxide, or tantalum oxide.

[0055] The current-carrying portion of the anode for electroplating according to the present application has a plurality of current paths arranged at intervals from each other in the above-mentioned first direction. The "current path" as used herein refers to a path through which electric current flows, and a plurality of current paths can be formed by providing a plurality of electrically conductive members that constitute the current-carrying portion, or by providing an electrically conductive member that constitutes the current-carrying portion with a branched structure. In some embodiments, the plurality of current paths are arranged uniformly dispersed in the anode.

[0056] The arrangement of the respective current paths at intervals from each other means that gaps are formed in the region where the current-carrying portion exists, and thus the total area of the liquid-receiving portion of the entire current-carrying portion is smaller than the area of the liquid-receiving portion when all of the current-carrying portion is assumed to be a series of flat plates, i.e., the area of the outer shape of the region where the current-carrying portion is arranged. The ratio (Sc / So) of the area (Sc) of the liquid-receiving portion of the current-carrying portion to the area (So) of the outer shape of the region where the current-carrying portion is arranged is not particularly limited, and can be, for example, about 0.5 or less, about 0.3 or less, or about 0.25 or less, and can be about 0.05 or more, 0.1 or more, or 0.125 or more.

[0057] Although not limited by a particular theory, it is believed that in the vicinity of the anode, an oxygen generation reaction and a decomposition reaction of an organic compound additive described later occur simultaneously due to an oxidation reaction, and when the area of the current-carrying portion in the plating solution is limited for the electrode, the anode current density (current per unit area of the current-carrying portion of the anode) becomes high, and in this state, the oxygen generation reaction occurs preferentially over the decomposition reaction of the organic compound additive compared to when the anode current density is low, and thus the decomposition of the organic compound additive is suppressed. Furthermore, it is believed that by arranging the current paths at intervals from each other in the anode, the increase in the plating bath voltage can be suppressed and the current distribution to the cathode can be stably maintained. If a conventional flat plate is assumed to be used as the anode, and the anode current density is increased without changing the area of the current-carrying portion, the applied current needs to be increased substantially, but in this case, the bath voltage also increases, which is not economical and can also affect the durability of the anode. Furthermore, if the applied current is increased substantially, the cathode current density also increases substantially, and thus adverse effects on the plating quality can also occur. If the anode for electroplating according to the present application is used, the anode current density can be increased without these adverse effects, and the decomposition of the organic compound additive can be suppressed.

[0058] The cross-sectional area (S2) of the current-carrying portion of the anode for electroplating according to the present application is not particularly limited as long as it is smaller than the cross-sectional area of the support portion, and can be, for example, about 3 mm 2 to about 75 mm 2 , about 4.5 mm 2 to about 50 mm 2The ratio (S2 / S1) of the cross-sectional area (S2) of the current-carrying portion to the cross-sectional area (S1) of the support portion is not particularly limited, and may, for example, be about 0.5 or less, about 0.004 to about 0.25, or about 0.007 to about 0.16.

[0059] The electrically conductive member constituting the current-carrying portion is not particularly limited as long as it can carry current, and may, for example, contain at least one selected from the group consisting of iron, nickel, stainless steel, carbon, platinum, platinum-coated titanium, palladium-tin alloy, and a member coated with any of these, and preferably contains at least one selected from the group consisting of iron, nickel, stainless steel, and carbon. The shape of the current-carrying portion is not particularly limited, and may, for example, be a wire, expanded metal, punched metal, and / or a flat plate, and is preferably a wire. Since expanded metal and punched metal have branched structures, a plurality of current paths can be formed even when they are used alone.

[0060] In some embodiments, a plurality of the current-carrying portions can be provided in the anode for electroplating of the present application, and the plurality of the current-carrying portions are preferably provided uniformly dispersed in the anode. The interval at this time is not particularly limited, and for example, the current-carrying portions can be provided at an interval of about 10 cm or less or about 3 cm to about 7 cm in terms of the distance between the centers thereof. In some embodiments, the anode for electroplating of the present application can further have a current-carrying portion extending in the first direction. The current-carrying portion extending in the first direction is not particularly limited, and can have a plurality of current paths provided at intervals from each other in the second direction.

[0061] In the anode for electroplating of the present application, the scheme in which the current-carrying portion and the support portion are connected is not particularly limited as long as they can carry current to each other, and for example, the current-carrying portion 31 can be configured in a ladder shape between the both side portions of the support portion 41 (frame) configured to have an input portion 21 in the upper portion and to surround the periphery of the electrode except for the lower side (ladder-type anode for electroplating 1). In this case, a plurality of current paths 311 are provided in a direction orthogonal to the support portion 41. Alternatively, the current-carrying portion 32 can be configured in a lattice shape inside the support portion 42 (frame) configured to have an input portion 22 in the upper portion and to surround the entire periphery of the electrode (lattice-type anode for electroplating 1A). In this case, a plurality of current paths 321 are provided not only in a direction orthogonal to the support portion 42 but also in a direction in which the support portion 42 extends, and a plurality of current paths 322 are provided. An example of the ladder-type anode for electroplating in which the shape of the current-carrying portion is a wire is shown in FIG. 1. Figure 1 An example of the lattice-type anode for electroplating in which the shapes of the current-carrying portion and the additional current-carrying portion are wires is shown in FIG. 2. Figure 2 .

[0062] The anode for electroplating of the present application can be subjected to any modification commonly used in the technical field as long as the object is not impaired, or can be subjected to treatment for suppressing the increase in bath voltage, suppressing the increase in bath temperature due to heating of the current passage portion, or suppressing the decomposition of the above-mentioned organic compound additive, and the like. For example, if a part of the surface of the electrically conductive member constituting the above-mentioned current passage portion is covered with an insulating material and the other part is exposed, the area of the current passage portion in the plating solution of the above-mentioned electrode is limited, the anode current density (current per unit area of the current passage portion of the anode) becomes high, and this is useful for suppressing the decomposition of the above-mentioned organic compound additive.

[0063] In another embodiment, the present application also relates to a method for electroplating an article with a metal, the method comprising a step of passing current in a plating bath containing ions of the metal and an organic compound additive, wherein the plating bath has the article as a cathode and has the anode for electroplating of the present application. According to the method of the present application, the increase in bath voltage and the increase in bath temperature due to heating of the current passage portion can be suppressed, and the plating bath is uniformly and effectively passed with current, and a good plated film can be formed on the article.

[0064] The metal is not particularly limited as long as it is used for electroplating, and for example, the metal can contain zinc, nickel, iron, copper, cobalt, tin, manganese, and the like. If the metal is only zinc, a zinc film is formed on the article, and if the metal contains zinc and another metal, a zinc alloy film is formed on the article. The other metal is not particularly limited as long as it can form the above-mentioned zinc alloy film, and for example, it can be at least one selected from the group consisting of nickel, iron, cobalt, tin, and manganese. The zinc alloy film is not particularly limited, and for example, it can be zinc-nickel alloy plating, zinc-iron alloy plating, zinc-cobalt alloy plating, zinc-manganese alloy plating, or tin-zinc alloy plating, and the like.

[0065] The article is a plated article, and a general article in the technical field can be used without particular limitation. The article can be, for example, various metals such as iron, nickel, copper, zinc, aluminum, and alloys thereof. In addition, the shape is not particularly limited, and various shapes such as a plate-shaped article such as a steel sheet, a plated steel sheet, and the like, a cuboid, a cylinder, a cylindrical body, a spherical article, and the like can be mentioned. As the shaped article, specific examples include fastening members such as a bolt, a nut, a washer, and the like, a pipe member such as a fuel pipe, a cast iron member such as a brake caliper, a common rail, and the like, and various shaped articles such as a connector, a plug, a housing, a nozzle, a seat belt fastener, and the like.

[0066] The conditions of the current passage step are not particularly limited as long as the plating film of the metal can be formed on the article, and for example, the current can be passed at a temperature of about 15°C to about 40°C, preferably about 25°C to about 35°C, or the current can be passed at about 0.1 to 20 A / dm 2 , preferably 0.2 to 10 A / dm 2The cathode current density of the above-described power supply section is not particularly limited, and can be, for example, about 25 to about 150 A / dm 2 , preferably about 25 to about 75 A / dm 2 , and further preferably about 30 to about 65 A / dm 2 . The magnitude of the current with respect to the cross-sectional area (S2) of the above-described power supply section is not particularly limited, and can be, for example, about 2 to about 75 A / mm 2 , preferably about 5 to about 20 A / mm 2 .

[0067] The "organic compound additive" described in the present specification refers to an organic compound added to a plating bath used for electroplating. The type of the above-described organic compound additive is not particularly limited, and in the case where zinc plating is performed, for example, the above-described organic compound additive can be at least one selected from the group consisting of a brightener, a water quality adjuster, and a defoaming agent, and in the case where zinc alloy plating is performed, the above-described organic compound additive can be at least one selected from the group consisting of a brightener, a metal complexing agent, a water quality adjuster, and a defoaming agent. In any case, in a preferred embodiment, the above-described organic compound additive contains a brightener.

[0068] As the above-described brightener, a brightener commonly used in the technical field can be used without particular limitation, and examples thereof include a base component type brightener that mainly contributes to the covering power of a plated film and the uniformity of electrodeposition properties, a bright component type brightener that mainly directly contributes to the gloss imparting of a plated film, and an auxiliary component type brightener that mainly assists in the gloss imparting of a plated film in a low current density section.

[0069] The base component described above is not particularly limited, and for example, can include (1) nonionic surfactants such as polyoxyethylene polyoxypropylene block polymers, acetylene glycol EO adducts, anionic surfactants such as polyoxyethylene lauryl ether sulfate, alkyl diphenyl ether disulfonate; (2) polyallyl amines such as copolymers of diallyldimethyl ammonium chloride and sulfur dioxide; polycondensates of ethylenediamine and epichlorohydrin, polycondensates of dimethylaminopropylamine and epichlorohydrin, polycondensates of imidazole and epichlorohydrin, polycondensates of imidazole derivatives such as 1-methylimidazole and 2-methylimidazole and epichlorohydrin, polycondensates of heterocyclic amines including triazine derivatives such as acetoguanamine and benzoguanamine and epichlorohydrin, and polyepoxy polyamines; (3) polyamine polyurea resins such as polycondensates of 3-dimethylaminopropyl urea and epichlorohydrin, polycondensates of bis(N,N-dimethylaminopropyl) urea and epichlorohydrin; (4) water-soluble nylon resins such as polycondensates of N,N-dimethylaminopropylamine, alkylene dicarboxylic acids, and epichlorohydrin; (5) polyalkylene polyamines such as polycondensates of diethylenetriamine, dimethylaminopropylamine, and 2,2'-dichlorodiethyl ether, polycondensates of dimethylaminopropylamine and 1,3-dichloropropane, polycondensates of N,N,N',N'-tetramethyl-1,3-diaminopropane and 1,4-dichlorobutane, and polycondensates of N,N,N',N'-tetramethyl-1,3-diaminopropane and 1,3-dichloropropan-2-ol; and (6) imidazole derivatives.

[0070] The nitrogen-containing heterocyclic quaternary ammonium salt described above is, for example, a nitrogen-containing heterocyclic quaternary ammonium salt having a carboxyl group and / or a hydroxyl group. The nitrogen-containing heterocyclic ring of the nitrogen-containing heterocyclic quaternary ammonium salt described above is not particularly limited, and for example, can be a pyridine ring, a piperidine ring, an imidazole ring, an imidazoline ring, a pyrrolidine ring, a pyrazole ring, a quinoline ring, or a morpholine ring, and the like, and is preferably a pyridine ring. More preferably, the nitrogen-containing heterocyclic quaternary ammonium salt described above is a quaternary ammonium salt of nicotinic acid or a derivative thereof. In the nitrogen-containing heterocyclic quaternary ammonium chloride compound described above, the carboxyl group and / or the hydroxyl group can be directly bonded to the nitrogen-containing heterocyclic ring described above, or can be bonded via another substituent group, for example, like a carboxymethyl group. In addition to the carboxyl group and the hydroxyl group, the nitrogen-containing heterocyclic quaternary ammonium salt described above can have an additional substituent group, for example, an alkyl group, and the like. Furthermore, in the nitrogen-containing heterocyclic quaternary ammonium salt described above, the N substituent group that forms the heterocyclic quaternary ammonium cation is not particularly limited as long as it does not interfere with the effects as a gloss agent, and for example, can be a substituted or unsubstituted alkyl group, an aryl group, an alkoxy group, and the like. The counter anion that forms the salt is not particularly limited, and for example, can be a compound including a halide anion, an oxygen anion, a borate anion, a sulfate anion, a phosphate anion, an imide anion, and the like, and is preferably a halide anion. Since such a quaternary ammonium salt simultaneously contains a quaternary ammonium cation and an oxygen anion within the molecule, it also exhibits behavior as an anion, and is therefore preferred.

[0071] Specifically, the above-mentioned nitrogen-containing heterocyclic quaternary ammonium salts can be, for example, pyridine N-benzyl-3-carboxypyridinium chloride N-phenethyl-4-carboxypyridinium chloride N-butyl-3-carboxypyridinium bromide N-chloromethyl-3-carboxypyridinium bromide N-hexyl-6-hydroxy-3-carboxypyridinium chloride N-hexyl-6-3-hydroxypropyl-3-carboxypyridinium chloride N-2-hydroxyethyl-6-methoxy-3-carboxypyridinium chloride N-methoxy-6-methyl-3-carboxypyridinium chloride N-propyl-2-methyl-6-phenyl-3-carboxypyridinium chloride N-propyl-2-methyl-6-phenyl-3-carboxypyridinium chloride N-benzyl-3-carboxymethylpyridinium chloride 1-butyl-3-methyl-4-carboxyimidazolium bromide 1-butyl-3-methyl-4-carboxymethylimidazolium bromide 1-butyl-2-hydroxymethyl-3-methylimidazolium chloride 1-butyl-1-methyl-3-methylcarboxypyrrolidinium chloride or 1-butyl-1-methyl-4-methylcarboxypiperidinium chloride The above-mentioned nitrogen-containing heterocyclic quaternary ammonium salts can be used alone or in combination with two or more.

[0072] The concentration of the above-mentioned base component in the plating bath as a gloss agent is not particularly limited, and can be, for example, about 1 to about 500 mg / L, preferably about 5 to about 100 mg / L in the case of aromatic carboxylic acids, and about 0.01 to about 10 g / L, preferably 0.02 to 5 g / L in other cases.

[0073] The above-mentioned gloss component as a gloss agent is not particularly limited, and can include, for example, aromatic aldehydes such as veratraldehyde, vanillin, and anisaldehyde. The concentration of the above-mentioned gloss component in the plating bath as a gloss agent is not particularly limited, and can be, for example, about 1 to about 500 mg / L, preferably about 5 to about 100 mg / L.

[0074] The above-mentioned auxiliary component as a gloss agent is not particularly limited, and can include, for example, thiouracil compounds, mercapto compounds such as 2-mercaptobenzimidazole, and organic acids. The concentration of the above-mentioned auxiliary component in the plating bath as a gloss agent is not particularly limited, and can be, for example, about 0.01 to about 50 g / L.

[0075] As the water quality adjusting agent, a water quality adjusting agent commonly used in the technical field can be used without particular limitation, and for example, a silicic acid or the like can be used. The concentration of the water quality adjusting agent in the plating bath is not particularly limited, and for example, it can be about 0.01 to about 50 g / L. As the defoaming agent, a defoaming agent commonly used in the technical field can be used without particular limitation, and for example, a surfactant or the like can be used. The concentration of the defoaming agent in the plating bath is not particularly limited, and for example, it can be about 0.01 to about 5 g / L.

[0076] As the metal complexing agent, a metal complexing agent commonly used in the technical field can be used without particular limitation, and for example, an amine-based chelating agent or the like can be used. For example, the amine-based chelating agent can include an alkylene amine compound such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, or the like; an alkylene oxide adduct of the alkylene amine such as an ethylene oxide adduct, a propylene oxide adduct, or the like; an amino alcohol such as ethanolamine, diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, ethylenediamine tetra-2-propanol, N-(2-aminoethyl)ethanolamine, 2-hydroxyethylaminopropanol, or the like; an alkanol amine compound such as N-(2-hydroxyethyl)-N,N',N'-triethylethylenediamine, N,N'-di(2-hydroxyethyl)-N,N'-diethylethylenediamine, N,N,N',N'-tetra(2-hydroxyethyl)propylenediamine, N,N,N',N'-tetra(2-hydroxypropyl)ethylenediamine, or the like; a poly(alkylene imine) obtained from ethylene imine, 1,2-propylene imine, or the like; a poly(alkylene amine) obtained from ethylenediamine, triethylenetetramine, or the like; a poly(amino alcohol), or the like. Preferably, the metal complexing agent includes at least one selected from the group consisting of an alkylene amine compound, an alkylene oxide adduct thereof, and an alkanol amine compound. The metal complexing agent can be used alone or in combination with two or more. The concentration of the metal complexing agent in the plating bath is not particularly limited, and for example, it can be about 5 to about 200 g / L, and preferably about 30 to about 100 g / L.

[0077] The method of the present application can further include any process commonly used in the technical field without impairing the object thereof. For example, the method of the present application can further include a process of cleaning the article before the power supply process, a process of cleaning the article after the power supply process, or the like.

[0078] In addition, in another embodiment, the present application also relates to a system for electroplating an article with a metal, the system including: a plating bath containing ions of the metal and an organic compound additive, the plating bath having the article as a cathode, and having the anode for electroplating of the present application. According to the system of the present application, the increase in bath voltage and the increase in bath temperature caused by heating of the power supply portion can be suppressed, and the plating bath can be uniformly and effectively supplied with power, and a good plated film can be formed on the article.

[0079] The system of the present application can further include any device commonly used in the art without impairing the object of the present application.

[0080] The present application will be specifically described below by way of examples, but the scope of the present application is not limited to these examples.

[0081] Example

[0082] 〔Example 1〕

[0083] An iron frame of "コ" shape with the lower side open (length 620 mm x width 110 mm (inner width 80 mm), cross-sectional area 225 mm 2 ) was used as a support portion, and 19 iron wires (diameter 2.5 mm) were installed at intervals of 30 to 31 mm in the horizontal direction (in a ladder shape) in the support portion (the distance from the first wire to the 19th wire was 550 mm). A member (input portion) to be in contact with the power supply connecting portion was installed on the upper portion of the iron frame. Then, only the iron frame portion was coated with a masking paint MR-54 (manufactured by TOKAN Co., Ltd.) containing a styrene-based butadiene rubber (insulating material) to produce the anode for electroplating of Example 1. The anode was energized through the iron wire portion (energization portion; width 80 mm) and the area of the liquid contact portion portion when the anode was disposed in such a manner as to follow the wall surface of the electrolytic cell and to be immersed in the electrolyte solution as a whole was calculated to be 0.6 dm 2 (= 0.025 dm x 3.14 x 0.8 dm x 1 / 2 x 19). On the other hand, the outer shape area of the liquid contact portion of the anode (the outer shape area of the region in which the iron wire was disposed: So) was calculated to be 4.4 dm 2 (= 5.5 dm x 0.8 dm), and therefore Sc / So was calculated to be 0.14. In addition, the ratio (S2 / S1) of the current direction cross-sectional area (S2) of the iron wire to the current direction cross-sectional area (S1) of the iron frame was calculated to be 0.022.

[0084] 〔Example 1〕

[0085] The anode for electroplating of Example 1 was disposed in such a manner as to follow the wall surface of the electrolytic cell and to be immersed in the electrolyte solution as a whole in the electrolytic cell containing the electrolyte solution having the composition described in Table 1.

[0086]

Table 1

[0087] Table 1: Composition of electrolyte

[0088]

[0089] *1 amine chelating agent (epoxyethane adduct of alkylene amine) manufactured by Dipsa Corporation

[0090] As with the anode for plating of Example 1, an iron plate having the same outer shape area (length 550 mm x width 80 mm; both the outer shape area and the area of the liquid contact portion were 4.4 dm 2 ) or an iron plate having the same area of the liquid contact portion (length 550 mm x width 11 mm; both the outer shape area and the area of the liquid contact portion were 0.6 dm 2 ) was set in the electrolytic cell as the anode of Comparative Example 1 or 2, respectively. Then, a pickling steel plate (SPHC-P steel plate) was set in each electrolytic cell as the cathode, and power was applied under the conditions described in Table 2. During the power application, the electrolytic cell was set in a larger water tank, and the surrounding of the electrolytic cell was cooled with cooling water and a cooler to maintain the bath temperature.

[0091] [Table 2]

[0092] Table 2: Power application conditions

[0093]

[0094] Before and after the power application, 30 mL of the electrolyte was taken, respectively. Then, the concentration of IZ-250YB was measured by ion chromatography. In addition, the bath voltage immediately after the start of the power application and the bath temperature during the power application were measured. The results are shown in Table 3.

[0095] [Table 3]

[0096] Table 3: Test results

[0097]

[0098] *2 Since the bath temperature rose to 31°C one hour after the start of the power application, the power application was stopped for 10 minutes to cool to 25°C. Thereafter, the power application was continued while repeating this operation.

[0099] When the anode of Comparative Example 1, which is composed of a single iron plate, is used, the chelating agent IZ-250YB is decomposed. However, when the anode of Example 1, which uses multiple iron wires as energizing parts to reduce the area of ​​the contact portion (energizing part to the electrolyte) and has an insulating coated frame with a cross-sectional area larger than the iron wires as a support portion, is used, the decomposition of IZ-250YB can be suppressed. On the other hand, when the anode of Comparative Example 2, which is composed of a small single iron plate, is used, the decomposition of IZ-250YB can be suppressed, but the bath voltage is higher than that of Comparative Example 1, and the bath temperature cannot be maintained by the cooling method used in this test. Therefore, if the anode has the same external area, by using multiple conductive members arranged off the ground as energizing parts, the decomposition of organic compound additives can be suppressed even when the bath voltage and bath temperature are increased.

[0100] [Production example 2]

[0101] A copper metal part (input section 23) that connects to the power supply connection part is installed on the upper part of the expanded metal mesh (specifications SW22, LW50.8, T3.2, W3.5; 600mm long × 100mm wide; opening ratio 65%) used as the power supply section 33, and a copper rod (5mm in diameter, 19.6mm² cross-sectional area) coated with styrene-butadiene rubber is installed on its side. 2 ) As a support part 43, it is manufactured Figure 3 The mesh-type electroplating anode (with frame) shown in Example 2. The mesh metal portion ( Figure 3 Enlarged illustration of Part IV) Figure 4 Each of these branch paths serves as a current path.

[0102] [Experimental Example 2]

[0103] In an electrolytic cell containing an electrolyte with the composition described in Table 4, the electroplating anode of Example 2 is arranged such that the lower 500 mm of the mesh metal serving as the energized part is immersed in the electrolyte along the wall of the electrolytic cell (the external area of ​​the anode in the immersion part is 5 dm²). 2 ).

[0104] Table 4

[0105] Table 4: Composition of the electrolyte

[0106]

[0107] *3 Depso Corporation manufactures amine chelating agents (ethylene oxide adducts of alkylene amines).

[0108] *4 Depso Corporation manufactures gloss agents (polyamines).

[0109] *5 Gloss agent (quaternary ammonium salt of nicotinic acid) manufactured by Dipsa Corporation

[0110] Without installing the copper rod, the plating anode of Comparative Example 3 was prepared in the same manner as the plating anode of Example 2 Figure 5 The plating anode of Comparative Example 3 shown in the drawing (without frame) was set in the electrolytic cell in the same manner as the plating anode of Example 2. Then, SPHC-P pickled steel sheets having a width of 100 mm were set as cathodes (inter-electrode distance 30 cm) in each electrolytic cell in the same manner as the anode, immersed by 500 mm of the lower portion, and the current value was increased from 25 A to 150 A in stages under the conditions described in Table 5, with each current value applied for 5 minutes. During the application of current, the electrolytic cell was set in a larger tank, and the bath temperature was maintained by cooling the surroundings of the electrolytic cell with cooling water and a cooler.

[0111] [Table 5]

[0112] Table 5: Current application conditions

[0113]

[0114] The anode current density at each current value was calculated, and the bath voltage was measured. The results are shown in Table 6.

[0115] [Table 6]

[0116] Table 6: Progress of bath voltage

[0117]

[0118] When the anode of Comparative Example 3 without frame was used, the bath voltage increased each time the current value was increased, and the upper limit of the voltage was reached in the test device before the current value reached 150 A, so current application under the conditions of 150 A could not be performed. On the other hand, when the anode of Example 2 with frame was used, the increase in bath voltage was suppressed. Therefore, if a support portion connecting the current application portion and the electrode connection portion is provided in the plating anode, the increase in bath voltage can be suppressed.

[0119] [Production Example 3]

[0120] An iron frame of "コ" shape with the lower side open (length 200 mm x width 80 mm (inner width 70 mm), cross-sectional area 19.6 mm 2) as a support, 6 iron wires (diameter 2.5 mm) were installed at intervals of 35 to 36 mm in the horizontal direction (in a ladder shape) (the distance from the 1st to the 6th was 179 mm). A member (input portion) which contacted with the power supply connecting portion was installed at the upper portion of the above iron frame. Then, only the above iron frame portion was coated with a masking paint MR-54 (manufactured by TOKAN Co., Ltd.) containing a styrene-based butadiene rubber (insulating material) to produce the anode for plating of Example 3. The anode was energized through the above iron wire portion (energized portion; lateral width 70 mm) and the area of the liquid contact portion portion when the anode was disposed in such a manner as to follow the wall surface of the electrolytic cell and to be immersed in the electrolyte solution as a whole was calculated to be 0.16 dm 2 (= 0.025 dm x 3.14 x 0.7 dm x 1 / 2 x 6). On the other hand, the outer shape area of the liquid contact portion of the anode (the outer shape area of the region in which the above iron wire was disposed: So) was calculated to be 1.253 dm 2 (= 1.79 dm x 0.7 dm), and therefore Sc / So was calculated to be 0.13. In addition, the ratio (S2 / S1) of the current direction cross-sectional area (S2) of the above iron wire to the current direction cross-sectional area (S1) of the above iron frame was calculated to be 0.25.

[0121] [Experiment Example 3]

[0122] In an electrolytic cell containing an electrolyte solution (plating solution) containing the composition described in Table 7, the anode for plating of Example 3 was disposed in such a manner as to follow the wall surface of the electrolytic cell and to be immersed in the electrolyte solution as a whole with the iron wire as the energized portion.

[0123] [Table 7]

[0124] Table 7: Composition of electrolyte solution (plating solution)

[0125]

[0126] *6 manufactured by DAI-ICHI KOGYO Co., Ltd.

[0127] *7 manufactured by DAI-ICHI KOGYO Co., Ltd.

[0128] In the same manner as the anode for plating of Example 3, an iron plate having the same outer shape area and liquid contact portion area (longitudinal 179 mm x lateral 70 mm; both the outer shape area and the area of the liquid contact portion were 1.253 dm 2) was set in the electrolytic cell as Comparative Example 4. Then, SPCC steel sheet was set as the cathode in each electrolytic cell, and electrolysis was performed under the conditions described in Table 8. The cathode was replaced every hour until the amount of current passed to the plating solution reached 100 Ah / L. In addition, NiSO4-6H2O was replenished at a rate of 200 g / kAh, and the plating solution was analyzed by high-speed liquid chromatography or capillary electrophoresis at 50 Ah / L of current passed and at 100 Ah / L of current passed for the amine chelating agent and the nitrogen-containing heterocyclic compound-based brightener, respectively, to replenish these organic compound additives in a manner to maintain the concentrations at the start of the electrolysis. For zinc ions, titration analysis was performed every hour to replenish the zinc ions by appropriately immersing metallic zinc in the plating solution in a manner to maintain the concentration at the start of the electrolysis. It should be noted that the electrolytic cell was set in a larger tank during electrolysis, and the temperature of the bath was maintained by cooling the surroundings of the electrolytic cell with cooling water and a cooler.

[0129] [Table 8]

[0130] Table 8: Electrolysis conditions

[0131]

[0132] At 50 Ah / L of current passed and at 100 Ah / L of current passed, the appearance of the plating solution was visually observed, the concentration of oxalic acid in the plating solution was measured by ion chromatography, and the concentration of sodium carbonate (Na2CO3) in the plating solution was measured by titration.

[0133] In addition, a Hull cell test (Hull cell long type) was performed using the plating solution before electrolysis or the plating solution after 100 Ah / L of current passed. Briefly, 500 mL of the plating solution before electrolysis or after electrolysis was placed in a long tank (anode iron plate: 65 x 65 x 0.5 mm, cathode iron plate: 65 x 200 x 0.5 mm) for the Hull cell test, and plating was performed under conditions of 2 A - 20 minutes, 25°C. The cathode after plating was taken out, and the appearance thereof was visually observed. Then, the plating film thickness at every 1 cm from the left end (high current density portion side end) of the cathode plate was measured using a fluorescent X-ray analysis device, and the Ni eutectoid ratio was measured using a fluorescent X-ray analysis device.

[0134] The concentrations of oxalic acid and sodium carbonate are shown in Table 9, and the appearance of the cathode after the Hull cell test is shown in Figure 6 The plating film thickness and the Ni eutectoid ratio are shown in Tables 10 and 11, respectively.

[0135] [Table 9]

[0136] Table 9: Changes in concentrations of oxalic acid and sodium carbonate

[0137]

[0138] [Table 10]

[0139] Table 10: Comparison of coating thickness based on distance from the high current density section end face

[0140]

[0141] Table 11

[0142] Table 11: Comparison of Nickel Eutectoid Ratio Based on Distance from the High Current Density Section Side End

[0143]

[0144] When the anode of Comparative Example 4, which consisted of a single iron plate, was used, the amounts of oxalic acid (a decomposition product of the chelating agent) and sodium carbonate (produced by the reaction of carbon dioxide generated from the decomposition of the chelating agent with caustic soda in the plating bath) were high, and the color of the plating bath changed from blue-purple to brownish-red upon energization. On the other hand, when the anode of Example 3 was used, the amounts of oxalic acid and sodium carbonate generated were lower than in Comparative Example 4, and the color of the plating bath maintained its initial blue-purple color after energization. These results confirm that when the anode of Example 3 was used, which reduced the area of ​​the contact portion (the portion energized to the plating bath) by using multiple iron wires as the energizing portion and had an insulating coated frame with a cross-sectional area larger than the iron wires as the support portion, the decomposition of organic compound additives was suppressed. Furthermore, it was confirmed that no increase in bath voltage occurred.

[0145] In Test Example 3, organic compound additives were added to maintain the concentration at the start of energization. However, when using the plating solution after energization using the anode of Comparative Example 4, compared to using the plating solution after energization using the anode of Example 3, the gloss range of the cathode ( Figure 6 The black portion of the cathode narrows, and the coating thickness and nickel eutectoid rate decrease (Tables 10 and 11). These results suggest that when decomposition aging products such as oxalic acid and sodium carbonate are generated, even with the addition of organic compound additives, the plating performance decreases. However, if the anode of Example 3 is used, such a decrease in plating performance can be suppressed, and the utilization efficiency of the plating solution can be improved.

[0146] As can be seen from the above, by providing a pair of support portions with a larger cross-sectional area than the energized portion and whose contact portion with the plating solution is covered with an insulating material between the input portion and the energized portion of the electroplating anode, the rise in bath voltage can be suppressed. Electroplating anodes with this configuration do not require auxiliary equipment or anolyte management, and do not require expensive or special metals, thus reducing the cost of electroplating.

[0147] Symbol Explanation

[0148] 1. Ladder-type anode for electroplating

[0149] 21 Input Section

[0150] 31 energizing section

[0151] 311 current path

[0152] 41 support section

[0153] 1A lattice type anode for electroplating

[0154] 22 input section

[0155] 32 energizing section

[0156] 321 transverse current path

[0157] 322 longitudinal current path

[0158] 42 support section

[0159] 1B mesh type anode for electroplating

[0160] 23 input section

[0161] 33 energizing section

[0162] 331 current path

[0163] 43 support section

[0164] 100 counter electrode anode for electroplating

[0165] 200 input section

[0166] 300 counter energizing section

Claims

1. One method is to electroplate an object with metal. include: The process involves applying an electric current to a plating bath containing ions of the metal and organic compound additives. The plating bath includes the article as the cathode and an anode for electroplating. The electroplating anode comprises: The input section receives power from the power source. A pair of support portions extend in a first direction and are spaced apart from each other in a second direction intersecting the first direction. They receive power from the input portion, and the portions that come into contact with the plating solution are covered with an insulating material. The energized part extends in the second direction, with one end connected to one of the pair of support parts and the other end connected to the other of the pair of support parts, and receives power supply from the pair of support parts; Furthermore, it further includes additional support portions that are directly or indirectly connected to the pair of support portions and constitute part or all of the outer periphery of the electroplating anode; The plating bath is an alkaline zinc plating bath or an alkaline zinc-nickel alloy plating bath. The energized part has multiple current paths arranged at intervals from each other in the first direction. The cross-sectional area of ​​the energized part is smaller than the cross-sectional area of ​​the support part.

2. The method according to claim 1, wherein, In the electroplating anode, the ratio of the liquid-contacting area Sc of the energized part to the outer surface area So of the region where the energized part is disposed, i.e., Sc / So, is 0.05 to 0.

5.

3. The method according to claim 1, wherein, In the electroplating anode, the ratio of the cross-sectional area S2 of the energized part to the cross-sectional area S1 of the support part, S2 / S1, is 0.5 or less.

4. The method according to claim 1, wherein, The electrified part includes metal wire, drawn metal and / or perforated metal.

5. The method according to any one of claims 1 to 4, wherein, The magnitude of the current relative to the liquid-contact area Sc of the energized part, i.e., the anodic current density, is 25–150 A / dm². 2 , and / or The magnitude of the current relative to the cross-sectional area S2 of the energized part is 2 to 75 A / mm². 2 .

6. A system for electroplating articles with metal. Contains: a plating bath containing ions of the said metal and organic compound additives. The plating bath includes the article as the cathode and an anode for electroplating. The electroplating anode comprises: The input section receives power from the power source. A pair of support portions extend in a first direction and are spaced apart from each other in a second direction intersecting the first direction. They receive power from the input portion, and the portions that come into contact with the plating solution are covered with an insulating material. The energized part extends in the second direction, with one end connected to one of the pair of support parts and the other end connected to the other of the pair of support parts, and receives power supply from the pair of support parts; Furthermore, it further includes additional support portions that are directly or indirectly connected to the pair of support portions and constitute part or all of the outer periphery of the electroplating anode; The plating bath is an alkaline zinc plating bath or an alkaline zinc-nickel alloy plating bath. The energized part has multiple current paths arranged at intervals from each other in the first direction. The cross-sectional area of ​​the energized part is smaller than the cross-sectional area of ​​the support part.

7. The system according to claim 6, wherein, In the electroplating anode, the ratio of the liquid-contacting area Sc of the energized part to the outer surface area So of the region where the energized part is disposed, i.e., Sc / So, is 0.05 to 0.

5.

8. The system according to claim 6, wherein, In the electroplating anode, the ratio of the cross-sectional area S2 of the energized part to the cross-sectional area S1 of the support part, S2 / S1, is 0.5 or less.

9. The system according to any one of claims 6 to 8, wherein, The electrified part includes metal wire, drawn metal and / or perforated metal.

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