JP2000008198A - Electrode lining for electrolysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high corrosion inhibition effect and insulating properties and a long service life by providing a discharge material composed of lead base metal joined to the surface side of a base material composed of iron, copper and titanium base metal and a flake lining layer obtd. by dispersing flakes such as glass into a resin on a non-discharge face including the exposed face of the base material. SOLUTION: An electrode lining 10 for electrolysis is composed in such a manner that a discharge material 12 of lead or a lead alloy joined to the surface side of a base material 11 of iron, copper, titanium or the alloys thereof is provided, a flake lining layer 13 small in soln. permeability and obtd. by dispersing flakes into a resin is provided on a non-discharge face including the exposed face of the base material 11, and furthermore, an FRP lining layer 14 composed of fiber reinforcing resins is laminated on the outside thereof. Since the flake lining layer 13 is provided, the permeation of an electrolytic soln. is prevented, the erosion of the base material is prevented, the insulating properties thereof is increased, and the service life of the electrode can be prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode lining for electrolysis, and more particularly to an electrode for a chrome plating line and a tin plating line used in an ironworks.

[0002]

2. Description of the Related Art Conventionally, an insoluble electrode used as an anode for chromium plating or tin plating uses lead or a lead alloy as a discharge material. Since lead and lead alloys have insufficient rigidity, distortion during electrolysis is large. For this reason, as shown in FIG. 2, the electrode lining for electrolysis 50 according to the conventional example has a structure in which a discharge material 51 made of lead or a lead alloy sandwiches a base material 52 made of mild steel having strength. On the other hand, since lead or a lead alloy is a conductive metal, the surface (discharge surface) that functions when electrolyzing is only the surface 53 facing the paired electrode, but the other surfaces also spill current. To discharge. For example, a lead or lead alloy anode electrode in a chromic acid electrolyte solution generates lead peroxide on its surface by anodic oxidation, and fulfills the function of both electrical conductivity and corrosion resistance. However, the above-mentioned electrode for electrolysis, at a potential lower than the potential at which lead peroxide is generated, lead peroxide generation becomes insufficient, and lead chromate or the like is generated, and the surface layer is ragged, and finally the surface layer falls off, It becomes difficult to protect the base material 52 inside. For this reason, it is necessary to insulate the surface other than the discharge surface. However, if the bonding or the adhesion between the discharge material 51 made of lead or a lead alloy and the base material 52 is poor, the lead or lead alloy layer will swell during electrolysis. Therefore, insulation is performed by the FRP lining 54 having high strength. This has made it possible to prevent deformation of lead and lead alloys.

[0003]

The conventional electrode for electrolysis described above is formed by casting a base material such as a mild steel around the entire circumference with a discharge material such as a lead alloy, so that the manufacturing method is complicated and troublesome. It was hanging. In addition, when lead on the discharge surface is consumed and the base material is exposed, the base material such as mild steel is eluted into the electrolytic solution, thereby contaminating the electrolytic solution. While leaving the electrode on the back side of the substrate. And FRP lining has high strength but corrosion resistance,
Lack of water vapor transmission resistance causes the electrolyte to penetrate from the surface other than the discharge surface, thereby shortening the life of the electrode. The present invention has been made in view of such circumstances,
An object of the present invention is to provide an electrode lining for electrolysis that has a high anticorrosion effect and insulation properties and has a long life.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
Electrode lining of the description, iron, copper, titanium, or a base material made of these alloys, a discharge material made of lead or a lead alloy bonded to the surface side of the base material, and the exposed surface of the base material And a non-discharge surface-containing scaly flake layer made of glass and other flaky flakes dispersed in a resin. The electrode lining for electrolysis according to claim 2 is the electrode lining for electrolysis according to claim 1, wherein an FRP lining layer made of a fiber-reinforced resin is laminated outside the flak lining layer.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. As shown in FIG. 1, an electrode lining for electrolysis 10 according to an embodiment of the present invention includes iron, copper,
A discharge material 12 made of lead or a lead alloy bonded to the surface side of a base material 11 made of titanium or an alloy thereof is provided, and a flaking layer 13 is provided on a non-discharge surface including an exposed surface of the base material 11, F made of fiber reinforced resin outside
The RP lining layer 14 is laminated.

In order to provide the discharge material 12 on the base material 11, for example, lead homogen processing is performed to raise a lead alloy welded to the base material 11 to a predetermined thickness. Base material 11
On the non-discharge surface including the exposed surface of the above, flake-like flakes such as glass having a thickness of 1 to 20 μm and a length of 5 mm or less are dispersed in the resin without intervening lead or a lead alloy, and the resistance to water vapor transmission is increased. A paste-like flaking layer (that is, having a low liquid permeability) is applied by a trowel or a spray gun. If the period until the base material comes into contact with the electrolyte is considered to be the life, in addition to the deterioration of the discharge material, the permeation of the electrolyte due to the deterioration of the lining layer becomes a problem. Hereinafter, the lining and its deterioration will be described in detail.

The problem with lining deterioration is mainly chemical deterioration. The chemical deterioration phenomenon occurs when an environmental agent (gas or liquid) enters the resin, and as a result, phenomena such as chemical reaction deterioration, swelling, craze, and swelling appear. Here, the swelling means that if the infiltrating environmental agent has a high affinity for the polymer substance, it infiltrates a large amount between the polymer molecules and widens the polymer molecule interval. In addition, craze refers to a phenomenon in which when an environmental agent infiltrates in a state where a stress is applied to a polymer substance, a molecular arrangement is locally shifted in a stress direction with the passage of time, and the location tends to be cracked. Considering the service life of 1 to 5 years, it is considered that the great effect is due to blistering. Among the causes of deterioration, those that cause swelling pass through the lining coating film with water molecules and oxygen (dissolved oxygen, etc.) and oxidize the surface of the base material, resulting in rust and initial adhesion of the lining It seems to be to weaken. For example, when the base material is made of mild steel, rust between the lining coating film and the iron base material or at the interface may be black rust (Fe ₃ O ₄ ) if the lining coating film is normal and has not been chemically degraded. Red rust (Fe), which has the greatest inhibition of adhesion due to insufficient oxygen
₂ O ₃ ) rarely occurs. Therefore, rather than oxygen permeation,
The magnitude of the permeability of water molecules (water vapor) to the coating film is the largest point that determines the lining life.

[0008] Flake lining is a method in which glass flakes or the like are dispersed in a resin. In a thickness of 1 mm, several tens of flake-like glass are dispersed and oriented in parallel with each other, and the highly corrosive electrolyte must penetrate while bypassing the flake layer. The resistance to water vapor permeation with respect to the electrolyte is higher than that of epoxy or FRP, and it is unlikely to cause lining deterioration such as swelling, cracking, or peeling, and does not weaken the adhesive strength with the substrate 11. .

The so-called corrosion resistance of flake lining is as follows:
It depends on the oil resistance of the base resin. Normally, polyester-based resins tend to be acidic, epoxy-based resins have high corrosion resistance to alkali-based resins, and vinyl ester-based resins have a strong tendency to both. Since the base material 11 is more rapidly attacked by the permeation than the electrolytic solution, the oil resistance of the lining material itself is usually not a problem.

[0010] Flake lining has high resistance to water vapor transmission, but is inferior in strength to FRP lining. Therefore, especially in the case of large-area electrodes such as steel plant plating line electrodes, in order to avoid the risk of cracks due to distortion due to aging, or the risk of scratches due to mechanical shock,
FRP lining layer 1 on flare lining layer 13
4 is given. As the FRP lining layer 14, several reinforcing glass fibers are laminated, a corrosion resistant layer having a high resin content is placed on the side in contact with the chemical, and a surface mat layer having a high resin content is generally placed on the chemical side. It is. This structure has a longer life and a simplified electrode structure compared to the conventional electrode lining for electrolysis. In addition,
The present invention is not limited to the above-described embodiment. For example, when a small electrode is used and high strength is not required, FRP
The lining layer 14 may be omitted.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described below. 200mm × 20
5% on a mild steel base material of 0mm x 6mm
5mm tin-lead alloy, 2m on back and side of discharge part
m, and immersed in a chromium electrolyte. One year later, he pulled it up and observed it. In the lead alloy portion, a yellow precipitate was observed on the surface, the surface was extremely rough, and a part of the surface was peeled off, whereas no change was observed in the flaking portion. A second embodiment will now be described.
A 5% tin-lead alloy was piled up to 5 mm on a 100 mm × 100 mm × 6 mm mild steel base material by homogen processing, and the back and side surfaces of the discharge part were subjected to 2 mm flare lining, and further a 0.8 mm FRP lining layer was applied. And chromium electrolysis. [CrO ₃ ] in the electrolyte is 100 g / L,
[F] is 3 g / L, [SO ₄ ^2- ] is 100 ppm,
Electric current was supplied at a current density of 50 A / dm ² . Six months later, the discharge lead portion was consumed and the service life was reached, but the lining portion was swollen and no phenomena such as cracking were observed at all. A third embodiment will now be described. On the back surface of a platinum electrode made of titanium having a size of 1100 mm × 1710 mm, 2 mm of flaking lining and 0.8 mm of FRP lining were applied, and tin plating was electrolyzed. At a current density of 30 A / dm ² and 15 months of use, no abnormality was observed in the lining.

[0012]

In the electrode lining for electrolysis according to the first and second aspects, since the non-discharged portion is provided with the flaking layer, the permeation of the electrolytic solution is prevented, the erosion of the base material is prevented, and the insulation is provided. It is possible to enhance the performance and extend the life of the electrode. Furthermore, there is no need to cover the entire substrate with a corrosion-resistant metal used as a discharge material such as lead or a lead alloy, and as a result, the discharge material can be arranged only on the discharge side of the electrode. As a result, it is possible to reduce the cost of the material used, and it is also easy to manufacture the material. In particular, in the electrode lining for electrolysis according to the second aspect, since the FRP lining layer is provided outside the flaking layer, the strength can be increased and the safety against impact can be enhanced.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an electrode lining for electrolysis according to an embodiment of the present invention.

FIG. 2 is a front sectional view of an electrode lining for electrolysis according to a conventional example.

[Explanation of symbols]

Reference Signs List 10 electrode lining for electrolysis 11 base material 12 discharge material 13 flak lining layer 14 FRP lining layer

Claims (2)

[Claims] 1. A base material made of iron, copper, titanium, or an alloy thereof, a discharge material made of lead or a lead alloy bonded to a surface side of the base material, and a non-conductive material including an exposed surface of the base material An electrode lining for electrolysis, comprising: a discharge surface having a flake-like layer having low liquid permeability in which flake-like flakes such as glass are dispersed in a resin. 2. The outside of the flaking layer,
The electrode lining for electrolysis according to claim 1, wherein an FRP lining layer made of a fiber reinforced resin is laminated.