JP2006037175A - Indirect energization type continuous electrolytic etching method for metal strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient indirect energization type continuous electrolytic etching method for a metal strip.
SOLUTION: A plurality of electrodes are sequentially arranged in the metal band traveling direction so as to face the etching surface of the metal band, and arranged between A system, B system, A system, B system,. In this case, I) repeats the voltage application for which the A system electrode becomes the cathode for a predetermined time and II) applies the voltage for which the A system electrode becomes the anode for a predetermined time. (Α ≧ 0), and / or electrolytic etching method that inserts time during which voltage is not applied between A system and B system electrodes during βmsec (β ≧ 0) during voltage application transition from II) to I) In 1), the etching mask is made alkali-soluble, the voltage application time M of I) is 0.1 to 10 msec, the voltage application time N of II) is 4 M to 20 Mmsec, and the metal band etching mask at the time of voltage application II) The effective current density to the non-formation region of the metal is 250-1500 A / dm ^2, and the non-formation region of the etching mask is dissolved by electrolytic etching, and then the etching mask is covered with an alkaline solution Dissolve and remove.
[Selection] Figure 1

Description

  In the present invention, one or both sides of a metal strip are etched surfaces, and at least a metal strip on which an alkali-soluble etching mask having an etching pattern is formed is formed at a high speed by electrolytic etching in a non-etched region. Indirect energization type continuous electrolytic etching method for metal band, in which the etching mask is dissolved and removed with an alkaline solution, and then the metal band for shadow mask is etched at high speed. The present invention relates to an electrolytic etching method.

The shadow mask has a large number of pores formed on a metal plate with a thickness of 0.1 to 0.2 mm by photo-etching technology and is attached to a color cathode ray tube, and the electron beam passing through the pores is correctly guided to the three primary color phosphors. It works to reproduce. The metal plate used as the substrate is a cold-rolled steel plate such as low carbon steel and amber (Fe-Ni alloy containing 36% by mass of Ni).
The shadow mask pores provided in the metal plate must be large on one side and small on the opposite side, and the cross-sectional shape must be widened toward the outside of the color cathode ray tube. This shape is for preventing the irregular reflection of the electron beam on the side surface of the pore. If the pore is straight, the electron beam is scattered on the side surface of the pore and the image contrast is lowered.

Thus, since the specially shaped pores must be processed with a fine pitch of 0.6 mm or less, the shadow mask is hardly manufactured by a method other than photoetching. In the photoetching process, a photosensitive film is formed on both sides of the shadow mask metal substrate, and a large hole is formed on the surface where the large hole is formed, and a small hole is formed on the surface where the small hole opposite to the surface is formed. After adhering the negative negative plate for use, exposure and development are performed to remove the unexposed portion, and an etching solution is sprayed by a spray method to perform etching to a target depth, and the base material after the primary etching After the etching resistance layer is formed on the photosensitive film on the small hole side and on the inside of the small hole by etching-resistant coating containing an etching resistance substance, and drying this, the large hole is the etching resistance of the small hole. This is roughly divided into a secondary etching process in which etching is performed until the layer reaches the layer and the opening diameter of the large hole portion reaches a predetermined size.
As an etching solution for photoetching, ferric chloride solution is the most common and widely used because it is inexpensive and has low toxicity, dissolves various metals and alloys, and has a high etching rate.

Simplifying the manufacturing process and defect rate by simultaneously etching from both sides by changing the concentration of each etchant on both sides of the metal substrate, such as productivity problems assuming such a photo-etching process Patent Document 1 discloses an invention capable of reducing the above.
In addition, solvent-resistant environmental problems from the solvent type that used a lot of halogen-based solvents and other organic solvents for diluting the corrosion-resistant coating used in the secondary etching process. In order to avoid this problem, Patent Document 2 discloses an invention that advantageously solves the wettability of the corrosion-resistant coating with respect to a metal base material that has become apparent as a result of being converted to an aqueous type.

On the other hand, the shape of the groove formed by electrolytic etching is stabilized, the groove width and groove depth are made more uniform, and especially the iron loss is less likely to deteriorate after the stress relief annealing used for the iron core of the power transformer. Patent Document 3 discloses an invention relating to an indirect energization type continuous electrolytic etching method and an indirect energization type continuous electrolytic etching apparatus for a metal strip, suitable for the production of iron loss unidirectional silicon steel sheets.
Japanese Unexamined Patent Publication No. 01-298178 Japanese Patent Laid-Open No. 07-014505 JP 2004-131841 A

The inventions described in Patent Document 1 and Patent Document 2 of the prior art are typically produced by spraying an etching solution made of ferric chloride solution by a spray method and performing etching to a target depth. Even if it is attempted to increase the etching rate in order to improve the performance, there is a limit naturally, and it is far from the electrolytic etching.
On the other hand, the invention described in Patent Document 3 has a possibility that the shape of the groove formed by electrolytic etching can be advantageously controlled, but it is an etching of a specially shaped pore such as a shadow mask, and It is not clear whether or not an alkali-soluble etching mask is suitable for etching.

  Therefore, the present invention employs an indirect energization type continuous electrolytic etching technique for etching a metal band on which an alkali-soluble etching mask is formed, and can perform high-speed processing and stabilize the shape formed by etching. It is an object of the present invention to provide an indirect energization type continuous electrolytic etching method for a metal strip, which is suitable for manufacturing a shadow mask.

First, a preliminary study up to the present invention will be described.
That is, in order to collect basic data on indirect energization type continuous electrolytic etching of a metal strip, as a preliminary experiment in which only the configuration when the A-system electrode is an anode is extracted from the invention described in Patent Document 3, one side Preliminary experiment in which an etching mask is selectively formed on the surface of the metal (with an etching pattern applied), and a groove is continuously formed by “electrolytic etching” on a metal strip having an etching mask formed entirely on the other surface. Went.

FIG. 5 shows an outline of the experimental apparatus in a longitudinal sectional view in the longitudinal direction. The main structure is that in the traveling direction of the metal band 1 opposite to the etching surface of the metal band 1 in which an etching mask is selectively formed (provided with an etching pattern) on the surface of one side that is continuously passed through. The electrode a4 'and the electrode b5' are sequentially installed, the electrolytic solution 3 is filled between the metal strip 1, the electrode a4 'and the electrode b5', and the DC power supply device 7 is disposed between the electrode a4 'and the electrode b5'. is doing.
A switch 9 is installed between the DC power supply 7 and the electrode a4 ′. By closing the switch 9, the electrode a4 ′ becomes an anode between the electrode a4 ′ and the electrode b5 ′. Apply voltage. The voltage application is interrupted by opening the switch 9. In addition, ringer rolls 11 and 12 are installed on the entry / exit side of the electrolytic cell 2 as a transport roll for the metal strip 1 to suppress the outflow of the electrolytic solution 3 to the outside of the cell. Sink rolls 13 and 14 are installed in the tank, and the distances between the electrodes a4 'and b5' and the metal strip 1 are kept constant.

FIG. 6 shows an example of voltage application to the electrode a4 ′ between the electrode a4 ′ and the electrode b5 ′ in the experimental apparatus of FIG. By applying this voltage, an electrolytic current flows from the electrode a4 ′ to the metal band 1 through the electrolytic solution 3 opposite to the electrode, the etching pattern portion of the metal band 1, and further to the metal band 1 opposite to the electrode b5 ′. This flows through the etching pattern portion and the electrolytic solution 3 to the electrode b5 ′.
In the electrolytic cell 2 between the electrode a4 'and the electrode b5', a non-conductive material is used for the purpose of suppressing the current from flowing directly from the electrode a4 'to the electrode b5' via the electrolytic solution 3. The shielding board 6 which consists of is installed. The electrode a4 ′ is a so-called anode (anode) and employs a Pt-based insoluble electrode so that the electrode itself is not etched, while the electrode b5 ′ is a so-called cathode (cathode) and is made of SUS316. An electrode was adopted. As the electrolytic solution 3, an aqueous solution of NaCl was used.

  Further, the metal strip 1 used in the experiment is a steel strip for a shadow mask, which is an alkali-soluble material composed of an ink obtained by adding a pigment to an acrylic resin provided with an etching pattern composed of a number of circles on the surface of one side thereof. An etching mask is formed, and on the opposite side, an etching mask made of the same material is formed on the entire surface.

  Using the experimental apparatus of FIG. 5 as described above, the present inventors apply the voltage shown in FIG. 6 to the electrode a between the electrode a and the electrode b, and zero the applied voltage (current density). Then, the metal strip 1 on which the etching mask was selectively formed (with an etching pattern) was processed by electrolytic etching, and the etched shape was observed.

FIG. 4 shows an example of changes in the electrolytic etching shape when the applied voltage (current density) is sequentially increased. When the current density is low, the formed shape is extremely less damaged by the etching mask and shows the shape shown in (a). When the applied voltage (current density) is increased and the effective current density of the etching pattern portion reaches 250 A / dm ² , the etching mask starts to be damaged from the portion in contact with the etching surface and exhibits the shape shown in (b).
Further, when the effective current density of the etching pattern portion is increased, the shape increases in diameter as shown in (c) and (d), and the hole shape becomes uneven, and the etching mask reaches 1500 A / dm ^2. Was severely damaged and exfoliated extensively.

  The inventors changed the steel type of the metal strip, or changed the etching mask material (acrylic, alkyd, epoxy, etc.) and electrolysis conditions (NaCl concentration, electrolyte temperature, effective current density in the groove), and various others. The etching shape was investigated under the conditions described above, but with a high applied voltage (high current density), damage to the etching mask was minimal, the hole diameter did not expand, the etching shape was stabilized, hole diameter variation, and hole depth. It was not possible to greatly reduce the variation of

  As the inventors of the present invention have made further studies, they pay attention to the physical property behavior of the solution in the vicinity of the etching pattern of the metal band relative to the so-called anode electrode (anode), particularly the pH behavior, and the local pH A confirmation experiment was conducted with the idea that the etching could be performed uniformly even at a high current density by suppressing the increase and preventing damage to the alkali-soluble etching mask.

As a result, as a means for suppressing a local increase in the pH of the electrolytic solution in the vicinity of the etching pattern of the metal strip relative to the so-called anode electrode (anode), the invention described in Patent Document 3 is applied, and during the electrolytic etching, It is extremely effective to periodically stop the generation of H _{2 on} the etching pattern surface of the metal band opposite to the so-called anode electrode (anode) and dissolve Fe to form iron hydroxide. This is the heading and the present invention.

That is, the gist of the present invention is as follows.
(1) A metal band that is etched continuously by indirect energization electrolytic etching on a metal band on which one or both surfaces of the metal band is an etching surface, and at least an etching mask having an etching pattern applied to the etching surface is formed. An indirect energization type continuous electrolytic etching method, wherein a plurality of electrodes are sequentially arranged in the advancing direction of the metal band so as to face the etching surface of the metal band, and the A system, the B system, the A system, and the B system. ,..., And an electrolyte is filled between the metal strip and the electrode group, and (I) a voltage application in which the A-system electrode becomes a cathode for a predetermined time between the A-system and B-system electrodes. And (II) voltage application in which the A-system electrode serves as an anode is alternately repeated for a predetermined time, and the time αmsec (α ≧ 0) is applied during the transition from the voltage application (I) to the voltage application (II). And / or from the voltage application of (II) above Indirect energization of the metal band, which inserts a period of time during which the voltage is not applied between the A-system electrode and the B-system electrode during the time βmsec (β ≧ 0) at the time of transition to the voltage application of (I) In the continuous electrolytic etching method,
With the etching mask used as an alkali-soluble etching mask, the voltage application time M in (I) is set to 0.1 to 10 msec, the voltage application time N in (II) is set to 4 M to 20 Mmsec, The effective current density to the non-formation region of the metal band etching mask at the time of applying the voltage of (II) is 250-1500 A / dm ² , the non-formation region of the etching mask is dissolved by electrolytic etching, and then with an alkaline solution, An indirect energization type continuous electrolytic etching method for a metal strip, wherein the etching mask is dissolved and removed.
(2) The metal band indirect energization type continuous electrolytic etching method according to (1), wherein the metal band is a metal band for a shadow mask that forms multiple holes.
(3) The metal band is an indirect metal band according to (1), characterized in that the metal band is a cold-rolled directional silicon steel sheet that forms a groove inclined by 3 to 15 ° with respect to the width direction. Energized continuous electrolytic etching method.

  According to the present invention, electrolytic etching of a metal strip on which an alkali-soluble etching mask is formed can be processed at a high speed, the formed shape is stabilized, and the hole diameter and hole depth are made more uniform. Therefore, the effect of the indirect energization type continuous electrolytic etching of the metal strip, which is particularly suitable for manufacturing a shadow mask having porosity, can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a facility for processing by indirect energization type continuous electrolytic etching on a metal band on which one or both sides of the metal band are etched surfaces and at least an etching mask provided with an alkali-soluble etching pattern is formed on the etched surface. The block diagram of an electrolytic cell is typically shown by a longitudinal vertical sectional view.

The main configuration is that the surface of one side that is continuously passed through is entirely formed with an etching mask, and the etching mask is selectively formed on the surface of the remaining one side, opposite to the etching surface of the metal strip 1, The electrode A4 and the electrode B5 are sequentially installed in the traveling direction of the metal band 1, the electrolyte solution 3 is filled between the metal band 1, the electrode A4, and the electrode B5, and the DC power supply devices 7 and 8 are interposed between the electrode A4 and the electrode B5. Is arranged. Switches 9 and 10 are respectively installed between the DC power supply devices 7 and 8 and the electrode A4, and switches 9 'and 10' are respectively connected between the DC power supply devices 7 and 8 and the electrode B5. is set up.
By closing the switches 9 and 9 'and opening the switches 10 and 10', a positive voltage is applied to the electrode A4 between the electrodes A4 and B5, and the switches 9 and 9 'are opened. Then, by closing the switches 10 and 10 ', a negative voltage is applied to the electrode A4 between the electrode A4 and the electrode B5. Further, the voltage application is interrupted by opening all the switches 9, 9 ', 10, 10'.

  In addition, in order to suppress the leakage current that flows directly from the electrode A4 to the electrode B5 or from the electrode B5 to the electrode A4 via the electrolytic solution 3, it is nonconductive in the electrolytic cell 2 between the electrode A4 and the electrode B5. A shielding plate 6 made of a conductive material is installed.

FIG. 2 shows an example of voltage application to the electrode A between the electrodes A and B according to the present invention.
Usually, a predetermined electrolytic current is adjusted to flow by applying a positive voltage or a negative voltage to the electrode A4 between the electrode A4 and the electrode B5.
For example, when the voltage application to the electrode A4 is a positive voltage application (the electrode A serves as an anode), the predetermined electrolytic current is etched from the electrode A4 to the electrolytic solution 3 and the metal strip 1 that are opposed to the electrode A4. Flows to the metal strip 1 through the portion (becomes the cathode), and further flows to the electrode B5 (becomes the cathode) through the etching pattern portion (becomes the anode) of the metal strip 1 opposite to the electrode B5 and the electrolytic solution 3. .

First, the electrolytic reaction on the metal band 1 (etching pattern portion) side by this electrolytic current will be described. That is, in the etching pattern portion of the metal band 1 on the side facing the electrode B5, an anodic reaction (electron emission reaction)
Me → Me ⁺ + e ⁻ (When the metal strip is a steel strip, Fe → Fe ²⁺ + 2e ⁻ )
As a result, electrolytic etching proceeds.
Moreover, in the etching pattern part (being a cathode) of the metal band 1 on the side opposite to the electrode A4 (being an anode), a cathodic reaction (electron accepting reaction)
2H ₂ O + 2e ⁻ → H ₂ ↑ + 2 (OH) ⁻
As a result, the pH of the electrolyte near the etching pattern portion shifts to the alkaline side. If this state continues for a long time, the electrolytic solution near the etching pattern portion largely shifts to the alkaline side and damages the etching mask.

Next, the electrolysis reaction on the electrode side by the above electrolysis current (when the voltage application to the electrode A4 is a positive voltage application) will be described.
That is, in the electrode B5 (which becomes the cathode), the cathode reaction (electron acceptance reaction)
2H ₂ O + 2e ⁻ → H ₂ ↑ + 2 (OH) ⁻
As a result, the pH of the electrolyte near the electrode B5 shifts to the alkaline side.
Further, in the electrode A4 (which becomes an anode), an anodic reaction (electron emission reaction)
2 (OH) ⁻ → (1/2) O ₂ ↑ + H ₂ O + 2e ⁻
As a result, the pH of the electrolyte near the electrode A4 shifts to the acidic side.

When the voltage application to the electrode A4 is a positive voltage application due to the electrolytic reaction as described above, as a whole electrolyte solution, the dissolved metal is
^{Me + + OH - → Me (} OH) ↓
Since the solution precipitates as a hydroxide, the pH of the solution reaches equilibrium when it is slightly inclined to the alkaline side.

On the contrary, when the voltage application to the electrode A4 is a negative voltage application (the electrode A becomes a cathode), a predetermined current flows in the opposite direction to the above case.
First, in the etching pattern portion (being a cathode) of the metal band 1 on the side opposite to the electrode B5 (becoming an anode), the cathode reaction (electron accepting reaction)
2H ₂ O + 2e ⁻ → H ₂ ↑ + 2 (OH) ⁻
As a result, the pH in the vicinity of the etched surface shifts to the alkaline side. Since this application time is short, the shift to the alkaline side is extremely small and there is almost no influence on the etching mask.

Moreover, in the etching pattern part (becoming an anode) of the metal band 1 on the side opposite to the electrode A4 (becoming a cathode), an anodic reaction (electron emission reaction)
Me → Me ⁺ + e ⁻ (When the metal strip is a steel strip, Fe → Fe ²⁺ + 2e ⁻ )
As a result, electrolytic etching proceeds. At that time, the eluted metal ions react with the electrolytic solution that is locally inclined to alkalinity to become hydroxide, thereby reducing the local pH bias toward the alkaline side. At the same time, the diffusion of the electrolytic solution proceeds, and the bias of the local pH toward the alkaline side is reduced by these two actions.

On the other hand, in the electrode B5 (becomes an anode), an anodic reaction (electron emission reaction)
2 (OH) ⁻ → (1/2) O ₂ ↑ + H ₂ O + 2e ⁻
As a result, the pH of the electrolyte near the electrode B5 shifts to the acidic side. In addition, in the electrode A4 (which becomes the cathode), the cathode reaction (electron acceptance reaction)
2H ₂ O + 2e ⁻ → H ₂ ↑ + 2 (OH) ⁻
As a result, the pH of the electrolyte near the electrode A4 shifts to the alkaline side.
At this time, as a whole electrolyte solution, the dissolved metal
^{Me + + OH - → Me (} OH) ↓
Since the solution precipitates as a hydroxide, the pH of the solution reaches equilibrium when it is slightly inclined to the alkaline side.

In the present invention, both the electrode A4 and the electrode B5 may be an anode or a cathode. Therefore, in order to prevent the electrode itself from being subjected to electrolytic etching in the case of the anode, for example, an insoluble material such as a Pt system is used. It is good to make from material.
In addition, as a means for performing electrolytic etching treatment of the metal strip at high speed, it is effective to install a plurality of electrode arrangements in the electrolytic cell as electrode A, electrode B, electrode A, electrode B..., Electrode A, electrode B. . It is also effective to install a plurality of electrolytic cells. In this specification, the plurality of electrodes A or B are collectively referred to as an A-system electrode or a B-system electrode, and may be simply referred to as an electrode A or an electrode B.

  In the present invention, as in the voltage application pattern shown in FIG. 2, the voltage application between the A-system and B-system electrodes is such that (I) the A-system electrode becomes a cathode during a time M = 0.1 to 10 msec. And (II) it is necessary to alternately repeat the voltage application in which the A-system electrode serves as the anode during the time N = 4 M to 20 Mmsec.

  When the A-system electrode of (I) is a cathode and the B-system electrode is an anode, when M is a voltage application time (msec), when a voltage of less than 0.1 msec is applied, a so-called anode electrode (anode) is formed. Since it is not sufficient to eliminate the local pH bias to the alkaline side in the vicinity of the etching pattern of the opposing metal band, on the other hand, when a voltage application of M exceeds 10 msec, the efficiency of electrolytic etching is reduced. Time M was defined as 0.1 to 10 msec.

  In addition, when the A-system electrode in (II) is an anode and the B-system electrode is a cathode, when N is a voltage application time (msec), application of a voltage with N less than 4 Mmsec reduces the efficiency of electrolytic etching. On the other hand, when a voltage of N exceeding 20 Mmsec is applied, the local pH bias toward the alkaline side in the vicinity of the etching pattern of the metal band relative to the so-called anode electrode (anode) becomes temporarily too large. N = 4M-20Mmsec.

Here, the arrangement of the electrodes when a plurality of electrodes A and B are installed or when a plurality of electrolytic cells are installed will be described.
Generally speaking, the last electrode in the direction of travel of the metal band is a viewpoint that prevents the substance in the electrolyte from adhering to the metal band (cathode) due to the cathodic reaction (the etching pattern part of the metal band is used as the anode) Therefore, the cathode is desirable. In the present invention, the electrode A and the electrode B are used by alternately switching between the anode and the cathode, but the time distribution in the voltage application of the above (I) and (II) is always N> M. The B-type electrode is mainly the cathode. Therefore, it is desirable that the last electrode in the traveling direction of the metal strip is a B system mainly serving as a cathode from the viewpoint of preventing the substances in the electrolyte from adhering to the metal strip.

Further, during the transition from the voltage application of (I) to the voltage application of (II), during the time αmsec (α> 0) and / or from the voltage application of (II) to the voltage of (I) Inserting a time interval during which no voltage is applied between the A-system electrode and the B-system electrode for a time βmsec (β> 0) when switching to application is also effective for stable electrolytic etching. It is.
In an actual electrolytic etching facility, an electrical so-called LC circuit is formed between the electrolytic power supply device and the electrodes A and B, or between the electrodes A and B and the metal strip, This is because the time delay that occurs when switching the cathode may be a problem. The problem of time delay due to the LC circuit becomes more apparent as the equipment scale increases.
FIG. 3 shows an example of voltage application to the electrode A between the electrode A and the electrode B according to the present invention in order to solve such a problem.

  However, it is not preferable to use a time during which no voltage is applied so that α or β exceeds 10 msec, because it causes a decrease in the electrolytic etching rate or an increase in the length of the electrolytic etching equipment (electrolyzer). Since it cannot be an effective solution to the problem of time delay caused by the LC circuit, α or β is preferably in the range of M to 10 msec.

Further, when the effective current density on the etching pattern surface is less than 250 A / dm ² , there is a problem that the efficiency of electrolytic etching is low. On the other hand, if it exceeds 1500 A / dm ² , the heat generated by the metal to be etched becomes so large that it is not practical. Therefore, the effective current density of the etching pattern surface is set to 250~1500A / dm ^2.

FIG. 4 shows an example of the electrolytic etching shape when the applied voltage (current density) is sequentially increased from zero. When the current density was low, the formed shape showed very little damage to the etching mask, and the shape shown in (a) was shown. Even when the applied voltage (current density) is further increased and the effective current density on the etching pattern surface reaches 250 A / dm ² , the etching mask is very little damaged, and even at 1500 A / dm ² , the etching mask is largely damaged. There wasn't. As a result, it was confirmed that the shape formed by the electrolytic etching according to the present invention was very stable even at a high current density, all became a concave shape as shown in FIG.

  The metal strip 1 used in the experiment is a steel strip for a shadow mask, and an alkali-soluble etching mask made of an ink obtained by adding a pigment to an acrylic resin provided with an etching pattern made of many circles on the surface of one side thereof. An etching mask made of the same material is formed on the entire surface on the opposite side. As the electrolytic solution 3, an aqueous solution of NaCl was used.

The electrolytic power supply device used in the present invention is not limited to the switching system using the DC power supply device and the switch described above, and any system can be used as long as it can take the voltage application cycle described above.
The present invention provides an etching mask in which one or both surfaces of a metal strip are etched surfaces, and at least the etching surface is provided with an alkali-soluble etching pattern made of any of inks obtained by adding a pigment to a resin such as acrylic, alkyd, or epoxy. The composition of the resist solution that forms an alkali-soluble etching pattern, which is effective for all cases where the formed metal strip is continuously grooved stably by indirect energization type electrolytic etching, and the resist solution This method is effective regardless of the coating method and the resist film forming method (drying and baking method, etc.). Further, the etching mask may or may not be formed on the entire remaining surface when only one surface of the metal strip is used as the etching surface.

FIG. 7 shows the electrolysis of equipment for processing by indirect energization continuous electrolytic etching on a metal band on which both sides of the metal band are etched surfaces and an etching mask having an alkali-soluble etching pattern is formed on the etched surface. The block diagram of a tank is typically shown by a longitudinal sectional view in the longitudinal direction.
The difference from the equipment of FIG. 1 is that the electrode part and the power supply unit part are arranged on both the upper side and the lower side of the metal band, and the amount of electrolytic etching on the upper side and the lower side of the metal band can be individually controlled. Thus, only a variable resistor is added between the power supply device and the electrode.

The effect of the present invention is that an alkali-soluble etching comprising any one of inks obtained by adding a pigment to a resin such as acrylic, alkyd, epoxy, etc., in which one or both surfaces of a metal strip is an etching surface and at least an etching pattern is provided on the etching surface. Indirect current continuous electrolytic etching method of metal band, in particular, shadow, in which the metal band on which the mask is formed is dissolved at high speed by electrolytic etching in the non-etching region of the etching mask, and then the etching mask is dissolved and removed with an alkaline solution. This is effective for an indirect energization type continuous electrolytic etching method of a metal band in which a metal band for a mask is etched at a high speed. This is because, in a shadow mask having multiple holes, the variation in hole shape becomes the variation in light transmittance as it is, and the problem becomes apparent.
Of course, the effect is effective even in a cold-rolled sheet of directional silicon steel sheet in which an etching mask is selectively formed on one surface.

Hereinafter, the present invention will be specifically described based on examples.
The metal strip 1 used for the experiment is a steel strip for shadow masks, and an alkali-soluble etching mask made of ink with pigment added to an acrylic resin with an etching pattern made of many circles on the surface of one side is formed. On the opposite side, an etching mask made of the same material is formed on the entire surface.

The steel sheet for shadow mask subjected to the pretreatment as described above was subjected to electrolytic etching treatment using the electrolytic bath of the indirect energization type continuous electrolytic etching apparatus shown in FIG. For comparison, a pickling etching process by spraying was also performed (not shown).
[Steel Mask Steel Plate] Thickness: 0.10mm, Plate Width: 1000mm
[Etching Mask] It has an etching pattern with a pitch of 1 mm and a diameter of 0.1 mm.
[Electrolyte] Composition 500 g-NaCl / 1, liquid temperature: 60 ° C.
[Pickling solution] Composition FeCl ₃ , 50 Baume, liquid temperature: 60 ° C.
[Target groove depth] 0.05mm
[Effective current density] 100 to 750 A / dm ²

After the electrolytic etching, the variation in the shape pattern of the holes formed by the electrolytic etching and the diameter of the holes was evaluated.
Table 1 shows test conditions and results when the voltage shown in FIG. 2, FIG. 3, or FIG. 6 is applied to the apparatus shown in FIG.

Example No. In the examples of the present invention shown in FIGS. 1 to 5, the effective current density was high (750 A / dm ² ) and the electrolytic etching time was 40 seconds, which was very short. ) Is more stable, and as a result, it can be seen that the variation in diameter (%) ((diameter standard deviation) / (average diameter) × 100) is extremely small.
In addition, No. of the example of the present invention. In FIG. 5, a special circuit configuration for avoiding the problem of time delay due to the LC circuit is employed. However, since this circuit configuration is based on a known technique, detailed description thereof is omitted.

On the other hand, in the comparative example No. No. 11 and Comparative Example No. 1 in which the ratio of positive voltage application time / negative voltage application time exceeds 20. In FIGS. 12 and 13, the shape of the hole is partially equivalent to the shape shown in FIG. 4 (a), but the shapes corresponding to FIGS. 4 (b), (c), and (d) are also mixed. As a result, the hole diameter variation was large and the quality was not satisfactory. The effective current density was 750 A / dm ² for all.

In addition, No. of the comparative example by the conventional voltage application method. As for Nos. 21 to 23, Nos. Having a low effective current density (long electrolytic etching time). The holes 21 (100 A / dm ² ) were all in the shape corresponding to FIG. 4 (a), but No. No. 21 was increased in effective current density (shortened electrolytic etching time). At 22 (250 A / dm ² ), the shape corresponding to FIG. 4 (A) disappeared, and the shapes corresponding to FIGS. 4 (B), (C), and (D) were mixed. Furthermore, the effective current density was increased (electrolytic etching time was shortened). In 23 (750 A / dm ² ), the etching mask was greatly damaged, and it was no longer possible to measure the diameter.

  Furthermore, No. of the comparative example which performed pickling etching. In No. 31, the shape of all holes is the shape corresponding to FIG. 4 (a), and the variation in diameter (%) ((standard deviation of diameter) / (average value of diameter) × 100) was extremely small. The pickling etching time is as long as 500 sec. The electrolytic etching time of 1 to 5 is not far from 40 sec.

It is a schematic explanatory drawing by the longitudinal direction vertical sectional view of the electrolysis apparatus which processes continuously by indirect energization type electrolysis etching to the metal belt in which the etching mask which gave the etching pattern to the surface of at least one side according to the present invention was formed. . It is a figure which shows the example of a voltage application to A system electrode between A system electrode and B system electrode based on this invention. It is a figure which shows another voltage application example to the A system electrode between the A system electrode and the B system electrode based on this invention. It is a figure which classify | categorizes and shows the pattern of the cross-sectional shape formed by electrolytic etching. It is similar to the conventional electrolytic pickling device for metal bands, and is an apparatus used in the preliminary experiment leading to the present invention, indirectly on the metal band having an etching mask provided with an etching pattern on at least one surface. It is a schematic explanatory drawing by the longitudinal direction vertical sectional view of the electrolysis apparatus processed continuously by energization type electrolytic etching. This is similar to the voltage application used in the conventional electrolytic pickling on the metal band, and an example of voltage application to the electrode a between the electrodes a and b in the experimental apparatus of FIG. 5 used in the preliminary experiment of the present invention. FIG. It is a schematic explanatory drawing by the longitudinal direction vertical sectional view of the electrolysis apparatus which processes continuously by indirect energization type electrolysis etching to the metal belt in which the etching mask which gave the etching pattern to the surface of both sides according to the present invention was formed. .

Explanation of symbols

1: Metal band 2: Electrolytic tank (electrolytic etching tank)
3: Electrolytic solution 4: Electrode A
4 ': Electrode a
5: Electrode B
5 ': Electrode b
6: Shield plate (non-conductive material)
7, 8: DC power supply device 9, 9 ', 10, 10': Switch 11, 12: Ringer roll 13, 14: Sink roll (dipping roll)
21, 21 ', 22, 22': Variable resistor

Claims (3)

Indirect energization of the metal band, where one or both surfaces of the metal band are etched surfaces, and at least an etching mask provided with an etching pattern on the etched surface is continuously etched by indirect energization electrolytic etching. In the continuous electrolytic etching method, a plurality of electrodes are sequentially arranged in the advancing direction of the metal band so as to face the etching surface of the metal band, and the A system, the B system, the A system, the B system,. And an electrolyte solution is filled between the metal strip and the electrode group, and (I) a voltage application in which the A-system electrode becomes a cathode for a predetermined time between the A-system and B-system electrodes; II) A voltage application in which the A-system electrode serves as an anode is alternately repeated for a predetermined time, and during the transition from the voltage application of (I) to the voltage application of (II) for a time αmsec (α ≧ 0), From the voltage application of (II) to the voltage application of (I) Indirect energization of the metal band, inserting a time interval in which no voltage is applied between the A-system electrode and the B-system electrode during one or both of the time βmsec (β ≧ 0) at the time of transition In the continuous electrolytic etching method,
With the etching mask used as an alkali-soluble etching mask, the voltage application time M in (I) is set to 0.1 to 10 msec, the voltage application time N in (II) is set to 4 M to 20 Mmsec, The effective current density to the non-formation region of the metal band etching mask at the time of applying the voltage of (II) is 250-1500 A / dm ² , the non-formation region of the etching mask is dissolved by electrolytic etching, and then with an alkaline solution, An indirect energization type continuous electrolytic etching method for a metal strip, wherein the etching mask is dissolved and removed.   2. The indirect energization type continuous electrolytic etching method for a metal band according to claim 1, wherein the metal band is a metal band for a shadow mask that forms multiple holes. The indirect energization type continuous electrolysis of a metal band according to claim 1, wherein the metal band is a cold-rolled directional silicon steel sheet that forms a groove inclined by 3 to 15 ° with respect to the width direction. Etching method.

Images