JPH04157198A - Method for power feeding to continuous coloring device - Google Patents

Abstract

PURPOSE:To allow uniform power feeding and uniform color developing by bringing plural leaf spring electrodes into contact with the non-colored surface on the rear surface of a metallic sheet which is transported while being immersed in a coloring liquid and power feeding while forming an air layer for suppressing the contact with the coloring liquid. CONSTITUTION:The leaf spring electrodes are preferably formed of titanium and the front ends 36a thereof are formed to an arc shape in such a manner that the electrodes are not attached by the coloring liquid having high corrosiveness and are surely conducted. The other parts are previously formed with insulating coatings 40 to avert the generation of a stray current in the coloring liquid 14. A metallic sheet 38 to be treated is placed on a partition plate 58 on a supporting body 56 fixed in the cell. The power is fed to the spacing 60 between the plate 58 and plate 38 formed at this time by the leaf spring electrodes 32. The coloring liquid is discharged when the air is fed to a blow-off port 64 of an air pipe 62 into this space 60 to bubble the liquid. The formation of the oxide film on the rear surface of the metallic sheet which is the non- colored surface is thus lessened.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a power supply method for a continuous coloring device, and in detail,
The present invention relates to a method of supplying power by contacting a metal plate to be colored immersed in a coloring liquid in a coloring tank.

<Conventional technology> Conventionally, continuous processing equipment, such as continuous electroplating equipment, continuous electrolytic pickling equipment, and continuous coloring equipment, continuously electrolytically treats metal plates such as sheet metal plates and metal strips by immersing them in a processing solution. In this method, electric power was supplied to the metal plate, which is the material to be treated, by conductor rolls provided before and after the processing tank or inside the processing tank.

For example, a power supply device for a metal strip disclosed in Japanese Patent Publication No. 58-18997 is capable of applying tin plating or zinc plating to a thin steel plate, anodizing, electrolytic roughening, or electrolytic cleaning treatment to an aluminum plate, etc. It is used for various continuous electrolytic treatments performed at high current density.In order to enable continuous electrolytic treatment at high current density, a conductor roll is installed in front outside the treatment tank, and a pass roll is used to wind the metal strip. A pressurizing means is provided to press the metal strip onto the conductor roll.

In addition, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 59-64796,
In continuous electroplating equipment where a conductor roll comes into contact with a highly corrosive plating solution, metal carbide powder and nickel are coated on the body surface of the conductor roll to prevent corrosion of the conductor roll that comes into contact with the plating solution. We are proposing a conductor roll coated with chromium alloy powder by thermal spray coating.

<Problems to be Solved by the Invention> By the way, the power supply device disclosed in Japanese Patent Publication No. 18997/1983 is intended for continuous electrolytic treatment that requires high current density, and does not require high current flow like continuous coloring treatment. Although the density may be low, it is not suitable for the purpose of uniform power supply on the colored surface of the material to be colored.

Furthermore, the method of supplying power using a conductor roll provided outside the processing tank, which has been widely used in the past, can be applied to metal strips.

It cannot be applied to continuous veneer threading of sheet metal plates.

For this reason, conventionally, the present applicant
In the above publication, a method was adopted in which the proposed corrosion-resistant coated conductor roll was immersed in a colored liquid to supply power, but as the exposed area in the colored liquid became excessive, a stray current was generated and the material to be colored was The current flowing through the colored surface becomes uneven,
There were problems such as adverse effects such as uneven coloring.

Furthermore, in the method proposed by the present applicant in JP-A-2-15191, in which power is supplied from the leaf spring electrode to a non-colored surface, an oxide film is formed due to the contact of the colored liquid to the non-colored surface, increasing the power feeding resistance. There were problems such as poor power supply.

Here, in the electrolytic coloring process, interference color is obtained by the thickness of the oxide film of the metal plate, which is the material to be colored, so uniform energization is necessary for uniform coloring of the metal plate. It is necessary to accurately control the power supply to the coloring liquid, and power must be supplied within the colored liquid.

However, power supply in a colored liquid has many problems, including the problems mentioned above.

For example, in the alternating current electrolytic coloring method, (1) power supply members that have corrosion resistance and chemical resistance in a mixed coloring solution of chromic acid and sulfuric acid are extremely limited in terms of materials.

■Since the electrolytic current density is as small as ±O, IA/drf,
It is necessary to reduce the exposed area of the conductor in the colored liquid.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to supply air to the contact area of the electrode when a corrosion-resistant leaf spring electrode is brought into contact with a metal plate that is immersed in a highly corrosive colored liquid and transported. Then, by forming an air layer to suppress contact with the colored liquid and supplying power to the metal plate through the leaf spring electrode,
It is an object of the present invention to provide a power supply method for a continuous coloring device that enables uniform power supply to the metal plate and enables uniform coloring of the metal plate.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a method for electrolytically coloring a metal plate that is continuously passed through the metal plate, which is immersed in a coloring liquid in a coloring tank of a continuous coloring device and then transported. A plurality of leaf spring electrodes made of a corrosion-resistant conductive material are brought into contact with the uncolored surface of the lower surface of the metal plate.
A power supply method for a continuous coloring device, characterized in that power is supplied from the leaf spring electrodes to the metal plate while supplying air between the leaf spring electrodes to form an air layer that suppresses contact with the coloring liquid. This is what we provide. The leaf spring electrode is
Preferably, it is made of titanium.

Further, it is preferable that the leaf spring electrode has an insulating coating except for the tip contact portion.

Further, it is preferable that the contact pressure of the leaf spring electrode with the metal plate is adjustable.

Further, it is preferable that the plurality of leaf spring electrodes are arranged at the entrance and exit of each cell of the coloring tank made up of the plurality of cells.

Further, it is preferable that the metal plate is horizontally threaded.

Furthermore, air is supplied to the area where the plate spring electrode passes over the non-colored surface of the lower surface of the metal plate while being in contact with it during transportation of the metal plate, thereby forming an air layer to prevent contact with the colored liquid and forming an oxide film. It is preferable to reduce the power supply resistance by suppressing the generation of. Note that when there are a plurality of leaf spring electrodes in the width direction of the metal plate, the passage area of the leaf spring electrodes also extends in the width direction of the metal plate.

In the present invention, the metal plate includes a sheet metal plate and a metal band.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of feeding power to a continuous coloring apparatus according to the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a diagrammatic sectional view of an embodiment of an alternating current electrolytic coloring apparatus for metal strips, which is equipped with a power supply device that implements the power supply method for a continuous coloring apparatus of the present invention.

In the figure, the alternating current electrolytic coloring device 1O is basically for electrolytically coloring the metal strip 12 while conveying it by a horizontal plate passing method. It is comprised of a conveying means 18 for conveying, and a power supply device 20 that implements the power supply method of the present invention.

Here, the method of coloring stainless steel sheets by alternating current electrolysis is achieved by optimally combining the anodic and cathodic electrical quantities of the alternating current. It is carried out in one liquid step. The coloring solution used here is mainly a mixed solution of chromic acid and sulfuric acid, with additions of other chromium compounds, molybdic acid, etc., as well as solutions containing permanganate, vanadium compounds, and other metal oxides in sulfuric acid or alkali. Any solution may be used as long as it can be colored by alternating current electrolysis, such as a solution mixed with a solution.

In the example shown in FIG. 1, the coloring tank 16 is divided into two parts, and includes a first coloring tank 22 and a second coloring tank 24.
2 is three cells 22a.

22b and 22c, and the second coloring tank 24 consists of one cell. In front of the first coloring tank 22, between the first coloring tank 22 and the second coloring tank 24, and after the second coloring tank 24, the colored liquid 14 leaking from the first and second coloring tanks 22 and 24 is removed. Receiving tank 26a, 26b, 2
Consists of 6 c. Here, the coloring tank 16 has a core material such as iron or stainless steel (SUS), but since the coloring liquid 14 is usually a highly corrosive acidic solution containing sulfuric acid or chromic acid, the inner surface of the coloring tank 16 is In particular, the inner surfaces of the first and second coloring tanks 22 and 24 must be coated with a material with high corrosion resistance, chemical resistance, and insulation properties, such as a fluororesin such as vinylidene difluoride or vinylidene tetrafluoride. Good.

Although the alternating current electrolytic coloring method has been described here, the present invention is not limited thereto, and any coloring method may be used as long as electrolytic coloring is performed continuously.

At the entrance and exit of the coloring tank 16, the first coloring tank 228, and the second coloring tank 24, seal roll pairs 28a, 28b are provided to prevent the filled coloring liquid 14 from leaking.
28c, 28d.

28e and 28f are provided. These seal roll pairs 28a to 28f may also serve as the conveying means 18 for the metal strip 12.

The conveying means 18 includes conveying rolls 29 a, 29 b, and 29 c on which the metal strip 12 is placed and conveyed.

It has 29d.

A power supply device 20 implementing the power supply method of the present invention is provided for each cell, and counter electrodes 30 a, 30 b, 3 are arranged at a predetermined distance on the colored upper surface of the metal strip 12.
0 c and 30 d, and a power supply jig 32 a consisting of a plate spring electrode provided so as to be in contact with the lower surface of the non-colored surface of the metal band 12 .

32b, 32c, 32d, counter electrodes 30a to 30d, and power supply jigs 32a to 32d, respectively, and power supply devices 34a, 34b, 34c, 34d consisting of rectifiers, controllers, etc., for flowing and adjusting electrolytic coloring currents. and an independent power supply device 34a to 34 for each cell.
'd are independently connected to supply power to corresponding counter electrodes 30a to 30d and power supply jigs 32a to 32d, respectively. For example 3 shown as each leaf spring electrode
2a usually has a plurality of leaf spring electrodes arranged at predetermined intervals in the board width direction, and the other parts 32b, 3
The same applies to 2c, 32d, . . . .

In the present invention, each leaf spring electrode 36 arranged in the metal band radial direction on the lower surface side of the non-colored surface of the metal band 12 contacts the metal band in the longitudinal direction of the metal band when the metal band is conveyed. For example, air is supplied between adjacent leaf spring electrodes or between a leaf spring electrode and a seal roll or a conveyance roll, preferably by bubbling, to form an air layer between the metal strip and the leaf spring electrode. This particularly prevents the colored liquid from coming into contact with the contact power supply portion of the leaf spring electrode.

Here, in FIG. 2, the power supply jig 32 consists of a cantilevered leaf spring electrode 36, and since the colored liquid is a highly corrosive solution as described above, the material of the leaf spring electrode must be chemical resistant and corrosion resistant. The material must be made of an elastic material, for example, a corrosion-resistant material, so as to ensure reliable contact with the metal plate 38 such as the metal strip 12 or sheet metal plate during movement of the metal strip 12 or sheet metal plate. Preferably, it is a chemically resistant metal, especially titanium.

Further, as shown in FIG. 2, the leaf spring electrode 36 has an arcuate tip portion 36a to ensure reliable contact with the metal plate 38, and the portion other than the tip contact portion 36a that contacts the metal plate 38 is It is preferable to apply an insulating coating 40 to prevent stray current from occurring in the colored liquid 14. Insulating coating 4
0 may be any material as long as it has insulating properties, chemical resistance, and corrosion resistance (for example, colored liquid 1
An oxide film coating that is passivated in step 4 may be formed in advance, or may be formed by reaction with the colored liquid 14.

Furthermore, on this oxide film, a coating of insulating resin such as vinyl chloride, vinylidene difluoride, vinylidene tetrafluoride, etc.
It is preferable to form an insulating coating 40 on the leaf spring electrode 36, such as a coating of fluorine rubber.

Here, the plate spring electrode 36 is not limited to the one shown in FIG. 2, but the dimensions of the plate spring electrode 36 include the size of the coloring tank 16, the size and position of the counter electrodes 30a to 30d, the dimensions and thickness of the metal plate 38. , and the electrolytic current value, etc., but for example, the width is 6 mm, the thickness is 2 mm, and the length is 300 mm.
The thickness of the insulating coating 40 is titanium (Ti).
) In the case of a plate spring electrode, it may be about 1 mm to 2 mm.

Here, when titanium is used as the material for the plate spring electrode 36, it is preferable to perform spring processing such as hardening in order to impart elastic force. The titanium plate spring electrode 36, which has a spring force, reacts with the colored liquid to form an extremely thin oxide film on its surface and becomes an insulator, but since this insulating coating 40 is extremely thin, the portion that contacts the metal plate 38 is Since it peels off easily and can generate a very good current, it is most suitable as a power supply jig for use in the power supply method of the continuous coloring device of the present invention.

FIG. 5 shows an example of an apparatus for forming an air layer between a metal plate and a leaf spring electrode. The metal plate 38 may be moving in a direction perpendicular to the paper surface or may be stationary. The metal plate 38 is placed on a partition plate 58 placed on a support 56 fixed within the tank. The space 60 formed at this time between the support body 56, the partition plate 58, and the metal plate 38 is the range in which the leaf spring electrode 32 comes into contact, and the leaf spring electrode does not penetrate the support body 56 (metallic plate 38). It is in contact with the board.

Air sent through an air pipe 62 is bubbled into this space 60 from an air outlet 64 to eliminate the colored liquid in this space 60 and form an air layer. As a result, the colored liquid 14
The lower surface of the metal plate is no longer in contact with the colored liquid, and the formation of an oxide film on the lower surface of the metal plate, which is a non-colored surface, can be suppressed, reducing power supply resistance and providing long-term use. This enables uniform energization.

Furthermore, the power supply jig 32 has a plate spring electrode 36 attached to the base of the plate spring electrode 36 so that the contact pressure with the metal plate 38 can be adjusted.
It is preferable to provide contact pressure adjustment means 42 for adjusting the height and inclination of the leaf spring electrode 36. The adjustment means 42 is for vertically moving and rotating the cantilever leaf spring electrode 36. Anything is fine if you have it. Leaf spring electrode 36
It is better to have a high contact pressure so that the metal plate 38 does not come off when running, but if it is too high, the metal plate 38 will be pushed up and the distance from the opposite electrode will change, causing color unevenness. It is preferable to adjust the contact pressure and spring strength to such an extent that the plate 38 is not pushed up.

Further, the power supply jig 32 consisting of the leaf spring electrode 36 is connected to the metal band 1
2 or the entire width of the metal plate 38 in the plate width direction, but it is more convenient to provide it in a part of the vicinity of the center as shown in FIG. 3 because it can accommodate changes in the plate width. FIG. 3 is a cross-sectional view of one embodiment of one cell of a coloring tank with a continuous coloring device, in which a metal strip 12 is immersed in a coloring tank 16 filled with a coloring liquid 14 and is transported by a transport roll 29. Electrolytic coloring is carried out by the power supply device 20 that implements the method of the present invention. At this time, as explained with reference to FIG. 5, air is applied to the range where each leaf spring electrode arranged in the width direction of the metal strip on the non-colored side of the lower surface of the metal strip 12 contacts in the longitudinal direction of the metal strip when the metal strip is conveyed. is supplied to form an air layer, which prevents contact with the colored liquid, suppresses the formation of an oxide film, and reduces power supply resistance. The power supply device 20 includes a counter electrode 30 having a split electrode so that the length can be changed according to the width of the metal strip 12.
is arranged at a predetermined distance from the metal strip 12, and a power supply jig 32 consisting of a plate spring electrode 36 is provided at a part of the center, that is, at a position facing the counter electrode in the center, so as to be in reliable contact with the metal strip 12. , the current from the power supply device 34 is uniformly applied to the metal band 12.

Next, FIG. 4 shows a continuous coloring device 50 that is capable of passing not only the metal strip 12 but also a single sheet metal plate 46. In the figure, the coloring tank 16 is composed of a single tank. It consists of a large number of cells, eight cells 52 in FIG. 4. Coloring tank 16
A pair of seal rolls 28 are provided at the inlet and outlet of the pump. A transport roll 29 is provided between each cell 52 and at the center of each cell.

Each cell 52 is provided with each power supply device 20 . As described above, each power supply device 20 consists of a counter electrode 30, a power supply jig 32 consisting of a plate spring electrode, and a power supply device 34, but the current flowing through each cell influences the current flowing through other cells. A shielding plate 54 is provided between the counter electrodes 30 of each cell to prevent uneven coloring.

Here, in the sheet metal plate 46, two adjacent cells 52 and 52 may be colored at the same time, but if the power supply jig 32 is placed only in the center between the entrance and exit of the cells 52, Even if the tip of the sheet metal plate 46 enters the next cell 52, it cannot contact the power supply jig and is not energized, resulting in uneven coloring. Each cell 52 as shown in the figure
It is preferable to provide them at two locations: the inlet and the outlet.

The method of the present invention may be applied to an apparatus having the configuration shown in FIGS. It is preferable to have a structure as shown in the figure.

In FIG. 6, a pinch roll 66 is disposed on the colored side of the metal strip 12, and a conveying day scroll 67 is disposed on the non-colored side of the metal strip 12, and the metal strip 12 is conveyed by both rolls in the direction shown by the arrow. At this time, the spring electrode 36 is connected to the day scroll 67.
position, but make sure that the leaf spring electrode 36 and the day scroll do not interfere with each other (i.e.,
The leaf spring electrode 36 is attached to the metal strip 12 as shown in FIG. 6(b).
It is preferably composed of a plurality of leaf springs near the center of the plate when viewed in the width direction of the plate, and the area shown by diagonal lines in FIG. day scroll 6 in the area not indicated by diagonal lines.
Place 7.

Here, by a bubbling device etc. illustrated in FIG.
An air layer is formed by at least bubbling in the region B between adjacent leaf spring electrodes in FIG. 6(a), which is the shaded region shown in FIG. 6(b), that is, the region through which the leaf spring electrodes pass during transportation. , the coloring agent should not be present between the leaf spring electrode and the metal band. Therefore, the bubbling region is between adjacent electrodes, and is the region on the non-colored surface of the metal strip that the leaf spring electrode (when made of multiple leaf springs, has a width in the leaf width direction) passes through when the metal strip is conveyed. corresponds to

As described above in detail, in the power supply method for the continuous coloring apparatus of the present invention, the power supply jig consisting of the leaf spring electrode is connected to the metal plate (
Air is supplied to the area where the leaf spring electrode passes while making contact with the lower non-colored surface (including sheet metal plates and metal strips) to form an air layer that prevents contact with the colored liquid and suppresses color development. Any type of device may be used as long as it implements a method of feeding the electrolytic current from the power supply device to the metal plate by contacting the metal plate in a manner that reduces the feeding resistance. .

<Example> The present invention will be specifically described below based on Examples.

(Example 1) A stainless steel cut plate was energized with a current density of 0, IA/dm". At this time, the contact area of the plate spring electrode was 0.03
The metal plate was covered with an air layer by bubbling air at a rate of m''/min/m2 to suppress the formation of an oxide film on the lower surface (uncolored part) of the metal plate.

The colored state of the lower surface of the metal plate at this time is shown in FIG.

In Figure 6, ■ is the material, ■ is when bubbling is present,
■ indicates when there is no bubbling.

The evaluation is shown as L''(CIE1976L@a'b'' color system (JISZ8729)), and it can be seen that color development is not suppressed in the case without bubbling compared to the case with bubbling. That is, it can be seen that an oxide film is formed on the lower surface of the metal plate, which is a non-colored surface, and the power supply resistance increases.

<Effects of the Invention> As described in detail above, according to the present invention, when electrolytically coloring a metal plate that is continuously passed through, the uncolored surface of the lower surface of the metal plate that is immersed in a coloring liquid and transported. A plate spring electrode placed on the side supplies air to the area where it passes while contacting the metal strip, forming an air layer and suppressing contact with the colored liquid, and connecting multiple plates made of corrosion-resistant conductive material. By bringing the spring electrode into contact and supplying power, power can be reliably, stably, and uniformly supplied to the metal plate that is the material to be colored.

In addition, in the present invention, the plate spring electrode that is coated with an insulating coating except for the tip contact portion has a small exposed area of the electrode in the coloring solution and can reduce stray current, so a uniformly colored metal plate can be used. Obtainable.

In addition, in the present invention, the plate spring electrode made of titanium not only has excellent corrosion resistance and chemical resistance, but also forms a thin insulating oxide film in the colored liquid, so it is not necessary to apply a special insulating coating. (However, stray current can be prevented.

In addition, in the present invention, the leaf spring electrode passes over the lower surface of the metal plate while being in contact with the lower surface of the metal plate (by supplying air to the area to form an air layer and suppressing contact with the colored liquid, as shown in FIG. 6). As described above, since the formation of an oxide film can be suppressed, the power supply resistance can be reduced.

Furthermore, in the present invention, the plate spring electrode that can adjust the contact pressure with the metal plate always makes contact with a predetermined contact pressure, so power supply is extremely stable.

Furthermore, in the present invention, the leaf spring electrodes arranged at the entrances and exits of each cell of the coloring tank can suitably supply power not only to metal strips but also to sheet metal plates.

Furthermore, the method of the present invention is particularly effective in horizontal plate passing systems.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a continuous coloring device that implements the power supply method for a continuous coloring device according to the present invention. FIG. 2 is a partially enlarged view of the power supply jig of the continuous coloring apparatus shown in FIG. 1. FIG. 3 is a cross-sectional view of an embodiment of a continuous coloring device that implements the power supply method for a continuous coloring device according to the present invention. FIG. 4 is a longitudinal cross-sectional view of another embodiment of a continuous coloring device that implements the power supply method for a continuous coloring device according to the present invention. FIG. 5' is a partial cross-sectional view of a bubbling device for forming an air layer in a region in contact with a power supply leaf spring electrode of a continuous coloring device according to the present invention. FIG. 6 is a diagram (a) and a partial perspective view (b) for explaining the bubbling region. FIG. 7 is a graph showing the effect of suppressing the formation of an oxide film when bubbling is carried out in the area in contact with the power supply plate spring electrode of the continuous coloring device according to the present invention. Explanation of symbols 10... Alternating current electrolytic coloring device, 12... Metal band, 14... Coloring liquid, 16.22.24... Coloring tank, 18... Transport means, 20... Power supply Apparatus, 22a, 22b, 22c, 52-.
- Cells, 28a, 28b, 28c, 28d. 28e, 28f...Seal roll pair, 30, 30
a, 30 b, 30 c, 30 d -・
- Opposite poles, 32.32a, 32b, 32c, 32d. 32el, 32e2...power supply jig, 34, 34a, 34b, 34c,
34 d... Power supply device, 36... Leaf spring electrode, 36a... Tip portion, 38... Metal plate, 40... Insulating coating, 42... Adjustment means, 46... Sheet metal plate, 50... Continuous coloring device, 54... Shielding plate, 56... Support body, 58... Partition plate, 60... Air layer space, 62... Air pipe, 64... ... Air outlet, 66... Pinch roll, 67... Conveyance disk port - rule \) - Color development system L" FIG, 6

Claims (6)

[Claims] (1) When electrolytically coloring a metal plate that is continuously passed through, a plurality of plates made of a corrosion-resistant conductive material are placed on the uncolored surface of the lower surface of the metal plate that is immersed in the coloring liquid in the coloring tank of the continuous coloring device and transported. A continuous method characterized in that power is supplied from the leaf spring electrodes to the metal plate while the spring electrodes are in contact with each other and air is supplied to the area between the leaf spring electrodes to form an air layer that suppresses contact with the colored liquid. How to power the coloring device. (2) The power supply method for a continuous coloring device according to claim 1, wherein the leaf spring electrode is made of titanium. (3) The method of feeding power to a continuous coloring device according to claim 1 or 2, wherein the leaf spring electrode has an insulating coating except for the tip contact portion. (4) The power supply method for a continuous coloring device according to any one of claims 1 to 3, wherein the contact pressure of the leaf spring electrode with the metal plate can be adjusted. (5) The method for feeding power to a continuous coloring device according to any one of claims 1 to 4, wherein the plurality of leaf spring electrodes are arranged at the entrance and exit of each cell of the coloring tank made up of the plurality of cells. . (6) The method for feeding power to a continuous coloring device according to any one of claims 1 to 5, wherein the metal plate is passed horizontally.