JPH0313599A - Insoluble electrode for electroplating - Google Patents

Abstract

PURPOSE:To obtain an insoluble electrode for electroplating having a long service life and stable electrode function by forming a coating layer of electrically conductive oxide ceramics having perovskite structure, pyrochlore structure, etc., on the surface of an electrode. CONSTITUTION:An iron plate 2 is successively coated with a Ti layer 3 and a Pb-4%Sn layer 4 and a resin lining 6 is formed to obtain an insoluble electrode for electroplating. A layer 5 of electrically conductive oxide ceramics having perovskite structure, pyrochlore structure, etc., is then formed on the surface of the electrode confronting a material to be plated. The ceramics having perovskite structure may be Na2WO3, SrIrO3, Ag0.5Ce0.5CrO3, Pb0.5Ce0.5 CrO3 or La0.2Sr0.8Fe0.2Co0.8O3. The ceramics having pyrochlore structure may be Pb<2>Ir2O7, Pb2Ru2O7, Bi2Ir2O7, Bi2Ru2O7, Tl2Ir2O7 or Tl2Ru2O7. Since the ceramic layer 5 prevents the exfoliation of oxide, the Ti layer 3 is not exposed over a prolonged period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to an insoluble electrode for electroplating.

(Prior art) Generally, when electroplating metal materials, an insoluble anode is used during electroplating, and metals such as Zn, Sn, and Ni are electroplated on the surface of the metal material to be plated using a cathode. There is.

The insoluble anode at this time is an insoluble anode formed by coating an iron plate 2 with a Ti layer and a Pb-4%Sn layer 4 thereon (hereinafter referred to as an insoluble anode made of Pb), as shown in Fig. 3. 10 are used.

In addition, when the Ti layer 3 of the electrode 10 becomes a current-carrying surface due to peeling and elution of the Pb-4%Sn layer 4, an oxidation reaction occurs on the Ti surface and TiO3, which is an electrical insulator, is generated, so that the Ti layer 3 becomes energized. It is generally provided to detect that it is impossible, and 6 indicates a resin lining.

Traditionally, insoluble anodes made of Pb have been used because Pb has corrosion resistance in electroplating baths, and when electricity is applied during the plating process, lead oxide C or less (PbO□) is formed on its surface, and this PbO2 This is because it functions as an insoluble anode.

However, in conventional Pb insoluble anodes, the PbO□ formed by surface oxidation becomes a scab and peels off from the electrode surface at an early stage, and the surface renewed by peeling repeats oxidation and peeling, eventually exposing the Ti surface. However, it loses power and must be replaced.

In order to extend this lifespan, it is desired to develop a completely insoluble electrode, and for example, in JP-A-61-44199,
Instead of the 4% Sn layer 4, or the above pb-4% Sn layer 4
An insoluble electrode for electroplating has been proposed, which is coated with a non-oxide conductive ceramic mainly composed of ZrB, TiB, or a composite thereof.

(Problem to be Solved by the Invention) However, when electricity is applied to the electrode coated with the above-mentioned non-oxide-based conductive ceramics, an electrical insulator (ZnO2, Tie, etc.) is generated due to an oxidation reaction, making it impossible to conduct electricity. The surface may be renewed due to peeling of the electrical insulator (ZrOz-TiO, etc.) and it becomes possible to conduct electricity, and these phenomena are repeated, resulting in unstable current value and unstable electrode function. There is a problem in that due to repeated oxidation peeling, the Ti layer is exposed at an early stage and becomes unable to conduct electricity and must be replaced.

The present invention provides an insoluble electrode for electroplating in which the period until the 11th layer is exposed is extended, the current value is stable, and the function as an electrode is stabilized.

(Means for Solving the Problems) This invention provides an electrode surface facing a material to be plated with N axW O3y S r I having a perovskite structure.
rO,,Ag,,,Ce,,,Coo,,Pb,,,C
e,,,CrO2゜L a,,,Sr,,,Fe,,,
Cr,,,O,P b, I with pyrochlore type structure
r, 07. Pb, Ru, O,, Bi, Ir, 07
゜Bi, RuzOttBizRhiOvt T Q 2
r70. , T Q zRu, Ov, or other insoluble electrode for electroplating.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a schematic diagram of the present invention, and FIG. 2 is a partial schematic diagram of an electroplating line (EGL) to which the present invention is applied.

In the figure, an insoluble electrode 1 consists of an iron plate 2, a Ti layer 3, and a Pb-
4% Sn layer 4, the oxide-based conductive ceramic layer 5,
It consists of a resin lining 6.

The oxide-based conductive ceramic layer 5 has hardness resistance and conductivity, and since it is an oxide-based ceramic, an oxidation reaction does not occur during plating treatment (when electricity is applied) and no electrical insulator is generated. ) No peeling. Therefore, in the insoluble electrode 1 of the present invention, the period until the 11th layer is exposed is extended, the current is stabilized, and the function as an electrode is stabilized.

As a coating method for the above-mentioned oxide-based conductive ceramics, methods such as coating by applying a solution containing a stoichiometric mixture of each component, drying and heat treatment, vapor deposition, and low-temperature gas spraying are generally used, but there are no particular restrictions. do not have.

Although the electrode in FIG. 1 is provided with the Pb-4%Sn layer 5, it may be omitted and the oxide-based conductive ceramic layer 5 may be provided directly on the Ti layer.

Figure 2 shows an example of the application of this invention, where 7 is a conductor.
8 is a roll, 9 is a plating solution, and 1 is an insoluble electrode of the present invention.

(Example 1) Nitrate, carbonate, and chloride solutions of each component of the material of the present invention shown in Table 1 were mixed stoichiometrically, and a Ti plate of cap 30 x length 150 x thickness 10 (unit: ■) was prepared. Coated on top and thermally decomposed, 800
The film thickness is 200mm by heat treatment at ~1000℃ for 24 hours.
A layer of μμ was formed to prepare an insoluble electrode test piece.

Using the test piece, Na, 804100 g/1
In an electrolytic solution with a bath composition of ltH, So410g/J1, a PT plated Ti plate of width 30 x length 150 x thickness 10 (unit: ■) was used as a cathode, and the current density was Intermittent electrolysis was performed for 240 hours, with the applied voltage being controlled to be constant at 15 OA/drrr, with electricity being applied for 50 minutes and interrupted for 10 minutes, and the weight loss was investigated after 240 hours of use. The experimental results are shown in Table 1.

Regarding the conventional materials shown in Table 1 & 1 and 2, the above Ti
An insoluble electrode test was prepared by plasma spraying the powder raw material onto a plate to form a 200μ thick film. The same experiment as above was conducted, and the results are also listed in Table 1.

Regarding the 12 types of inventive materials &3 to &14, there was not much difference in weight loss after 240 hours of use, and the weight loss was lower than that of the conventional material 171.
000 or less. In addition, the insoluble electrode test pieces of Ha 3 to 14 of the present invention materials were stable during test energization, but the ZrB2. TiB.

Regarding the electrode, the current value was not stable because the phenomenon of passivation peeling was repeated during test energization.

(Example 2) The electrode of the present invention was used as an anode of EGL. Anode shape 725
A comparison test was conducted with a conventional material (TiB) using X1800 (unit: m). The results of Example 1 show that in the material of the present invention, there is almost no difference in weight loss after 24Q hours of energization, so an example of an electrode coated with 5rIrO will be shown.

First, a Pb-4%Sn layer with a thickness of 15 am was formed by melting and solidifying Pb-4%Sn on the Ti surface, and after polishing the surface to remove the oxide layer generated on the surface, 5rCO,,I
A butanol solution in which rCQ3 was stoichiometrically mixed was applied, dried at 200'C for 11 hours, and then heat treated at 900°C for 20 hours to form a film with a thickness of 200 μm, which was used as an electrode. The conventional electrode was prepared by plasma spraying TiB2 on the polished Pb-4%Sn layer to form a TiB2 layer with a thickness of 200 .mu.m.

When the conventional product was inspected after 6 months of use, it was found that there were scattered peeling parts due to oxidation on the surface, and Tie was formed on the remaining surface.

However, in the present invention, although some roughness was observed on the surface during inspection after 6 months of use, no damage such as oxidation peeling that would reduce electrode function was observed, and long-term use was possible.

(Effects of the Invention) According to the present invention, it is possible to provide an electroplated, water-insoluble electrode in which the period until the Ti layer coated on the iron plate is exposed is extended, the current value is stable until the Ti layer is exposed, and the function as an electrode is stabilized.

Further, although this invention has been mainly described with respect to EGL, it is of course applicable to other electroplating lines and the like.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an insoluble electrode of the present invention, and FIG. 2 is an explanatory diagram of an example of application of the insoluble electrode for electroplating of the present invention to an EGL plating line. FIG. 3 is an explanatory diagram of a conventional insoluble electrode. 1... Electrode of the present invention 2... Iron plate 3 = 4'i layer
4.Pb-4%Sn layer 5...Oxide-based conductive ceramic layer 6...Resin lining 7...
・Conductor roll 8...Strip 9...
・Plating solution 10...Conventional electrode Fig. 3 538-

Claims (1)

[Claims] Na_xWO_3, SrIrO_3, Ag_0_.
_5Ce_0_. _5CrO_3, Pb_0_. _5C
e_0_. _5CrO_3, La_0_. _2Sr_0
＿． ___Fe_0_. _2Co_0_. ＿■O_3 Pb_2Ir_2O_7, Pb_ with vitrochlore type structure
2Ru_2O_7, Bi_2Ir_2O_7, Bi_2
Ru_2O_7, Bi_2Rh_2O_7, Tl_2I
An insoluble electrode for electroplating characterized by forming a coating layer of oxide-based conductive ceramics such as rO_7 and Tl_2Ru_2O_7.