JP2013249490A - Anodization apparatus and method for manufacturing metal substrate with anodic oxide film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a metal substrate with an anodic oxide film causing little warpage or defects at high efficiency.SOLUTION: An anodization apparatus 10 has a first electrolysis part 11 that anodizes a first plane 1a of a strip 1 and a second electrolysis part 12 that anodizes a second plane 11b of the strip 1 having an anodic oxide film formed on the first plane 1a. The first electrolysis part 11 and the second electrolysis part 12 are each capable of contacting and supporting a plane opposite to a plane to be anodized of the strip 1 and has: a power supply drum 20 that supplies power to the strip 1 from the plane; a counter electrode 30; an electrolytic cell 40 that stores an electrolyte L in which a part of the power supply drum 20 and the counter electrode 30 are soaked; and a protection member 60 that overlaps a short-length direction edge 1t of the strip 1 that is closely supported by the power supply drum 20 and a part of a power supply drum surface 20s that does not closely contact the strip 1 so as to protect them from the electrolyte L. A part 21d of a power supply drum 21 that closely contacts the strip 1 and a part 22d of a power supply drum 22 that closely contacts the short-length direction edge t that has been protected by the protection member 60 at the first electrolysis part 11 are formed from a conductive material.

Description

  The present invention relates to an anodizing device and a metal with an anodized film suitable for manufacturing a substrate with an insulating layer and an electrode for an electrolytic capacitor, which are useful for applications of semiconductor devices such as solar cells, thin film transistors, and displays (image display devices). The present invention relates to a method for manufacturing a substrate.

  Thin film solar cells using a metal substrate may be applicable to a wider range of applications than those using a glass substrate from the viewpoint of lightness and flexibility of the substrate. . Furthermore, since the metal substrate can withstand high-temperature processes, the photoelectric conversion characteristics are improved, so that high efficiency of the solar cell can be expected.

  The solar cell module improves the module efficiency by connecting the solar cells in series on the same substrate and integrating them. At this time, it is necessary to form an insulating layer on the metal substrate of the solar cell module and provide a semiconductor circuit layer for performing photoelectric conversion thereon.

  When an iron-based material such as stainless steel is used for the metal substrate with an insulating layer, an oxide insulating layer of Si or aluminum is formed on the substrate surface by a vapor phase method such as CVD or a liquid phase method such as a sol-gel method. . However, these methods are prone to pinholes and cracks in the manufacturing process, and have an essential problem as a method for stably producing a large-area thin film insulating layer (Patent Document 1).

  On the other hand, in the case of an aluminum substrate, by forming an anodic oxide film (AAO) on the surface, an insulating layer having no pinholes and good adhesion can be obtained (Patent Document 2). However, AAO on aluminum is known to crack when heated to 120 ° C. or higher (Non-Patent Document 1), and has a problem that leakage current increases due to a decrease in insulation. Yes.

  In addition, since aluminum softens at about 200 ° C., aluminum having a temperature higher than this temperature has extremely low strength and tends to cause permanent deformation (plastic deformation) such as creep deformation and buckling deformation. Strict restrictions are necessary. This makes it difficult to apply to outdoor solar cells.

  In order to solve the above problems, it is proposed to use a substrate with an insulating layer, which is a so-called aluminum clad material, on which a surface of a composite metal substrate clad with aluminum is formed with AAO as an insulating layer, as a substrate of a semiconductor device. ing.

  Such a substrate can be designed to have a small difference in linear expansion coefficient between the metal substrate and the compound semiconductor layer. Even in the formation process of the compound semiconductor layer that forms a high-temperature film of 500 ° C. or higher, cracks in the insulating layer Does not cause problems such as exfoliation of compound semiconductors. In addition, since the aluminum composite metal base material has a higher specific strength and higher temperature strength than aluminum, handling during manufacture is easy.

  AAO as an insulating layer needs not only to have a dielectric breakdown at a high voltage when used as a battery module, but also to have a small leakage current when a voltage is applied, that is, a high volume resistance. When the leak current is large, the generated current becomes a leak current between the individual batteries, and the module power generation efficiency decreases. Therefore, AAO requires a thickness of 1 μm or more, preferably 5 μm or more in order to ensure the above-mentioned performance.

  A general device for continuously anodizing strip-shaped aluminum is a structure in which a feeding roll or feeding tank is placed in the front part of the electrolytic cell and current is supplied to the aluminum. Even current flows.

  Anodization is electrolytic oxidation (three-electron reaction in the case of aluminum), and the thickness of AAO is proportional to the amount of electricity passed. Therefore, in the case of an apparatus that continuously anodizes strip-shaped aluminum, it is necessary to supply a current proportional to the line speed (running speed of the strip-shaped aluminum).

  At this time, since a proportional current also flows in the aluminum from the feeding portion to the electrolytic cell, the voltage drop increases and power loss occurs as the AAO thickness increases and the line speed increases.

  Furthermore, aluminum from the power feeding portion to the electrolytic cell may be melted by IR heat generation, and there is an upper limit to the AAO thickness to be generated and the line speed. Since the heat generation and the fusing limit current are determined by the resistance per unit cross-sectional area of the strip-shaped aluminum, the thinner the aluminum foil, the higher the resistance per unit cross-sectional area, and the lower the upper limit of the AAO thickness that can be generated and the line speed.

  There is a demand to form a thick AAO only on one side of a strip-like thin aluminum foil, like the metal substrate with an insulating layer. In this case, it is possible to apply a masking film on one side and manufacture with the above-mentioned apparatus, but there is an upper limit to the AAO thickness and the line speed.

  In addition, unlike additive films such as plating, AAO is a subtractive film, and easily forms a film when the electrolyte enters from the end face of the masking film. Therefore, it is necessary to select a masking film having a high adhesive strength. Furthermore, in the case of a strip-shaped metal foil joined with dissimilar metals such as clad material, a masking film is also applied to the side edges in the width direction where the dissimilar metals are exposed in order to prevent side reactions due to local cell action. Must be inactive.

  Various apparatuses for forming AAO only on one side of strip-shaped aluminum have been proposed. A typical example is a method in which a support drum on a cross-sectional circle is placed in an anodizing tank, and an aluminum foil is brought into close contact therewith to anodize only one side of the aluminum foil (Patent Document 3). In addition, a method has been proposed in which the support drum is made conductive and power is supplied to the drum (Patent Document 4, Patent Document 5, and Patent Document 6). In the drum power supply method, power is directly supplied from the back surface of the aluminum foil, so that the above-described voltage drop and heat generation can be reduced to a negligible level.

  In the drum power feeding method, there is a problem that the electrolyte solution is likely to be infiltrated between the support drum and the aluminum foil, and the loss current generated thereby tends to increase the contact resistance on the drum contact surface side, causing local defects such as sparks. is there. In the above Patent Documents 4 to 6, a configuration for suppressing the inflow of the electrolytic solution to the contact surface and the increase in contact resistance on the contact surface side due to the inflow is proposed, but the configuration is favorable with a simple configuration and an easy process. It is difficult to suppress an increase in contact resistance on the drum contact surface side.

  The present inventors have provided an anodizing apparatus capable of satisfactorily suppressing an increase in contact resistance on the drum contact surface side with a simple configuration and an easy process and an anodizing method using the same in a drum power feeding system. Proposed (Patent Document 7)

JP 2001-339081 A JP 2000-49372 A JP-A-4-371789 JP-A-60-211093 JP-A-6-108289 JP-A-46-39441 Japanese Patent No. 4723041

Takashima, et al., Tokyo Metropolitan Industrial Technology Research Institute Research Report 3 (2000) p21

  However, in a thin metal substrate with a high resistance per unit cross-sectional area, a substrate on which only one side of the anodic oxide film is formed is caused by thermal stress due to heating of the device layer film formation or changes in internal stress of the anodic oxide film. Warping is likely to occur and handling is difficult. If anodized films are formed on both sides of the substrate, it is considered that symmetry increases, warping is eased, and handling becomes easy. However, in the anodizing apparatus of Patent Document 7, first, the first surface of the strip-shaped aluminum is formed on the first surface. Even if the anodization is performed and the back surface thereof is subsequently anodized, the feeding surface becomes the first surface on which the insulating anodic oxide film is already formed, and therefore the second surface cannot be anodized. Double-sided anodization is possible if anodization is performed using a power supply roll or a power supply tank. However, as described above, this method has a problem that the upper limit of the line speed is low.

  The present invention has been made in view of the above circumstances, and an anodizing apparatus capable of forming an anodized film on both surfaces of a thin metal substrate having a high resistance per unit cross-sectional area with high efficiency, and the use thereof. It is an object of the present invention to provide an anodic oxidation method.

The anodizing device of the present invention is an anodizing device for anodizing both surfaces of a metal strip that is a metal that can be anodized on both surfaces,
A first electrolysis unit for anodizing the first surface of the strip, and a second electrolysis unit for anodizing the second surface of the strip with the anodized film formed on the first surface. And
The first electrolysis unit and the second electrolysis unit are capable of closely supporting a surface opposite to the anodized surface of the strip, and feeding a power drum to feed the strip from the surface;
A counter electrode provided to face the power supply drum;
An electrolytic cell storing an electrolytic solution for immersing a part of the power supply drum and the counter electrode that tightly supports the belt-like object; and
At least a short-side end portion of the on-band object that is tightly supported by the power supply drum immersed in the electrolytic solution and a portion of the surface of the power supply drum where the belt-shaped object does not adhere are overlapped and covered. The end portion is protected from the electrolyte solution, and at least a portion in contact with the electrolyte solution is non-conductive,
The power supply drum of the first electrolysis unit is formed of a conductive material at a portion where the belt-like object is in close contact,
The power supply drum of the second electrolysis unit is formed of a conductive material at a portion where the end in the short side direction of the belt-shaped object that is protected by the protection member in the first electrolysis unit is in close contact. It is a feature.

  In this specification, “the end in the short direction of the band” includes the end in the short direction of the band and the end on the anodized surface, and the second electrolysis unit on the anodized surface. In this case, the second surface of the belt-shaped object is fed with power from the end portion and has an area capable of anodizing.

  In the present invention, the metal strip may be composed of a single metal or an alloy, or may be a composite metal strip in which a plurality of types of metal layers are laminated in the thickness direction.

  In the second electrolysis unit, the distance between the power supply drum and the counter electrode in a portion where the power supply drum and the end of the strip in the short direction are in close contact is the power supply drum in the center of the power supply drum in the rotation axis direction. It is preferable that it is larger than the distance between the electrode and the counter electrode.

  In the second electrolysis section, it is preferable that the width of the counter electrode in the short direction of the strip is smaller than the width of the portion of the strip that is not protected by the protection member.

  In the power supply drum of the second electrolysis section, it is preferable that a portion where the portion where the anodized film is formed in the first electrolysis portion is non-conductive, and at least the surface of the portion is formed of rubber. More preferably.

  Moreover, it is preferable that the rotating shaft of the power supply drum is lower than the liquid level of the electrolytic solution.

  It is preferable that the power supply drum is provided with a recess in which the belt-shaped object travels in an intimate contact with the surface of the belt-shaped object. It is good also as an aspect which provides the guide roller which press-contacts the said protection member at least to the said edge part. The counter electrode preferably has a large number of through holes.

  The distance between the power supply drum and the counter electrode in the portion where the strip supported by the power supply drum is in contact with the electrolyte and / or the portion where the strip is separated is the central portion of the strip in the electrolyte immersion liquid. It is preferable that the distance is larger than the distance between the power supply drum and the counter electrode.

  The protection member preferably has an aspect in which at least a part of the portion in contact with the end portion in the short direction of the strip is made of a conductive material. In such an aspect, the protective member is preferably a non-conductive rubber or a metal foil covered with a non-conductive rubber. The conductive material of the power supply drum is preferably a conductive plastic or a conductive rubber. Moreover, it is preferable that the said protection member has an adhesive substance in the side closely_contact | adhered to the said strip | belt-shaped object.

  It is preferable that the potential of the counter electrode is negative with respect to the ground. In particular, it is preferable that the strip is set to the same potential as the ground, and the electrolysis power source for anodization is an insulated output with respect to the ground. It is further preferable that a monitoring unit that monitors the voltage of the power supply drum with respect to the potential of the ground is provided.

  It is preferable that the anodizing apparatus of the present invention is an embodiment in which one or both of the first electrolysis unit and the second electrolysis unit are arranged in series. Moreover, it is good also as an aspect by which many anodizing apparatuses of this invention were arrange | positioned in series.

The method for producing a metal substrate with an anodized film of the present invention is a method for producing a metal substrate with an anodized film in which both surfaces of a metal strip that is a metal that can be anodized on both sides are anodized,
When anodizing the first surface of the strip, continuously forming an anodized film and an anodized portion in the longitudinal direction of the strip,
When the second surface is anodized, power is supplied through the non-anodized portion of the first surface, and an anodized film is formed on the second surface. Such a production method can be preferably carried out by the anodizing apparatus of the present invention.

The anodizing apparatus of the present invention includes a first electrolysis unit that anodizes the first surface of the strip, and a second electrolysis unit that anodizes the second surface of the strip, and the first electrolysis unit In the second electrolysis unit, the first surface and the second surface can be supported by using a power supply drum capable of closely supporting and supporting the surface of the belt-like object opposite to the anodized surface and feeding the belt-like material from the surface. The end of the strip in the short direction, which is closely supported by the power supply drum immersed in the electrolytic solution, and the portion where the belt-like material on the surface of the power supply drum does not adhere are overlapped at least. A covering member that protects the end portion from the electrolytic solution, and at least a portion that is in contact with the electrolytic solution is non-conductive, and the power supply drum of the first electrolytic unit is in close contact with the belt The portion is formed of a conductive material, and the power supply drum of the second electrolysis unit is connected to the first electrolysis unit. In this case, the portion where the end in the short direction of the belt-like material protected by the holding member is in close contact is formed of a conductive material.
According to such a configuration, the short-side end portion of the belt-like material that remains without being anodized by being covered with the protective member in the first electrolysis portion can be used as a power feeding portion in the second electrolysis portion. . Therefore, according to the present invention, an anodized film can be formed on both surfaces of a thin metal substrate having a high resistance per unit cross-sectional area.

  Furthermore, the anodizing apparatus of the present invention is formed by overlapping and covering an end portion of the strip in the short direction and a portion where the strip on the surface of the power supply drum is not in close contact, and protecting the end portion from the electrolytic solution. Because the protective member is provided, the end of the strip in the short direction is prevented from touching the electrolyte during anodization, and the electrolyte is prevented from entering between the power supply drum and the strip. Therefore, an anodic oxide film having a high film thickness uniformity and a good surface condition can be formed on the first surface of the belt-like material with a stable contact resistance.

  Further, in the first electrolysis unit and the second electrolysis unit, since the belt is closely supported by the power supply drum, power can be directly supplied from the back surface of the belt, so that the voltage drop and heat generation can be ignored. This makes it possible to increase the line speed, so even with a strip having a high resistance per unit width, it is possible to form an anodic oxide film that has a high uniform film thickness and a good surface condition. Can be formed.

  Furthermore, in the aspect which made the part which the part in which the anodic oxide film of the strip | belt-shaped object is closely_contact | adhered in the electric power supply drum of the 2nd electrolysis part made into the nonelectroconductive material, in the anodic oxide film formed in the 1st surface, An electric field is not applied, and adverse effects such as dielectric breakdown due to the occurrence of sparks can be prevented.

The schematic perspective view which shows the structure of the anodizing apparatus of one Embodiment which concerns on this invention. Schematic front schematic view of the power supply drum of the first electrolysis unit of the anodizing device shown in FIG. Schematic front schematic diagram of the power supply drum of the second electrolysis unit of the anodizing device shown in FIG. Schematic schematic diagram for explaining the configuration and operation of the anodizing apparatus shown in FIG. Schematic sectional view showing a first preferred embodiment of the power supply drum and the counter electrode in the second electrolysis unit Schematic sectional view showing a second preferred embodiment of the power supply drum and the counter electrode in the second electrolysis unit The figure which shows the electric power feeding aspect to a strip | belt-shaped object when a protection member is nonelectroconductive in a 2nd electrolysis part. The figure which shows the electric power feeding aspect to a strip | belt-shaped object in case a protection member consists of a nonelectroconductive part and a conductive part in a 2nd electrolysis part. Schematic front schematic diagram of a power supply drum provided with a recess where the belt-like object travels inscribed It is a schematic diagram which shows the relationship between the width | variety and diameter of an electric power feeding drum, and a strip | belt shaped object and a protection member. It is a schematic sectional drawing which shows one Embodiment of the anodizing apparatus provided with the guide roller. FIG. 9 is a schematic front view of a power supply drum provided with the guide roller of FIG. Schematic diagram of the anodizing device when the potential of the counter electrode is negative with respect to the ground Schematic schematic diagram for explaining the configuration and operation of an anodizing device in which a large number of anodizing devices of the present invention are arranged in series. A diagram showing the relationship between travel speed and AAO formation speed

  Hereinafter, an anodizing apparatus and a method for producing a metal substrate with an anodized film according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of the anodizing apparatus of the present invention, and FIGS. 2A and 2B are a first electrolysis unit (FIG. 2A) and a second electrolysis unit (FIG. 2A) of the anodizing apparatus shown in FIG. FIG. 2B is a schematic front schematic view of the power supply drum of FIG. 2B). FIG. 3 is a schematic diagram for explaining the configuration and operation of the anodizing apparatus shown in FIG. In order to facilitate visual recognition, the scale of each part is appropriately changed and shown.

  As shown in FIGS. 1 and 3, the anodizing apparatus 10 anodizes both surfaces (1a, 1b) of a metal strip 1 which is a metal that can be anodized on both surfaces. The first electrolysis unit 11 for anodizing the first surface 1a and the second electrolysis unit 12 for anodizing the second surface 1b of the strip 1 having an anodized film formed on the first surface 1a. The In the present embodiment, after the first surface 1a is anodized by the first electrolysis unit 11, the second surface 1b is continuously anodized by the second electrolysis unit 12 without winding. .

  The first electrolysis unit 11 and the second electrolysis unit 12 can closely support the surface of the strip 1 opposite to the anodized surface (1b in the first electrolysis unit, 1a in the second electrolysis unit), and The power supply drum 20 (21, 22) that supplies power to the belt 1 from the surface, the counter electrode 30 (31, 32) provided to face the power supply drum 20, and the power supply drum 20 that closely supports the belt 1 The electrolysis tank 40 (41, 42) in which the electrolytic solution L for immersing a part of the electrode and the counter electrode 30 is stored, and the short of the strip 1 that is closely supported by the power supply drum 20 that is immersed in at least the electrolytic solution L. The end portion 1t in the hand direction and the portion of the power supply drum surface 20s (21s, 22s) where the strip 1 does not adhere are overlapped and covered, the end portion 1t is protected from the electrolyte L, and at least electrolysis is performed. Protection that the part in contact with the liquid L is non-conductive And a wood 60.

  The power supply drum 21 of the first electrolysis unit 11 is formed of a conductive material at the portion where the strip 1 is in close contact, and the power supply drum 22 of the second electrolysis unit 12 is protected by the protective member 60 in the first electrolysis unit 11. A portion 22d where the end in the short direction of the strip 1 is in close contact is formed of a conductive material.

  A power source 50 is connected to each power supply drum 20 and the counter electrode 30, and the strip 1 becomes an anode through the power supply drum 20 in the first electric field portion 11 and the second electric field portion 12 when the anodic oxide film is formed. So that current flows.

  On the upstream side of the power supply drum 21 of the first electrolysis unit 11, an unwinding roll 71 for winding the strip 1 in a roll shape, and on one side 1 a of the strip 1 fed to the power supply drum 21 on the downstream side. A guide roll G is provided for guiding the strip 1 after the anodic oxidation to the power supply drum 22 of the second electrolysis unit 12 so that the anodized surface becomes the second surface 1b. On the downstream side of the electrolysis unit 12, a winding roll 72 is provided for winding up the strip 1 that has been anodized on both sides.

  Further, in the vicinity of the power supply drum 21 and the power supply drum 22, unwinding rolls 72 and 73 for winding the protective member 60 in a roll shape, and winding rolls 82 and 83 for winding the protective member 60 after the end of anodization are provided. The protective member 60 is provided on both sides of the band 1 so that the end 1t in the short direction of the band 1 and the portion of the power supply drum surface 20s (21s, 22s) where the band 1 does not adhere can overlap each other. It has been.

  Each of the winding rolls 81, 82, 83 is provided with a drive unit (not shown), and electrolyzes the strip 1 and the protection member 60 that are in close contact with the power supply drum 20 in synchronization with the peripheral speed of the power supply drum 20. It can be made to co-run in the liquid L.

  In addition, the drive part provided in winding roll 81,82,83 drives the winding roll here, respectively, and demonstrates the aspect by which the strip | belt-shaped object 1 and the protection member 60 after anodic oxidation are wound up are demonstrated. However, the winding rolls 81, 82, 83 are simply rotatable and have a function of feeding the belt-like object 1 and the protection member 60, and the winding rolls controlled by separate driving units are respectively downstream thereof. The arrangement may be sufficient. In the case of this configuration, a washing tank for washing the anodized belt-like material with water or a drying tank for drying after washing between the winding roll 81 and another winding roll controlled by the drive unit. May be installed.

  The power supply drum 20 itself has a rotation shaft 20c and is simply rotatable (rotatable). The power supply drum 20 rotates in the rotation direction R, for example, about the rotation shaft 20c.

  For this reason, by driving the drive unit described above, the power supply drum 20 rotates in the rotation direction R and is transported in a state where only one surface of the strip 1 is immersed in the electrolyte L. . However, the power supply drum 20 may be provided with a drive source and may itself rotate in the rotation direction R, for example.

  It is preferable that the central axis of the rotating shaft 20c is lower than the liquid level of the electrolytic solution L.

  Although the diameter of the power supply drum 20 depends on the production scale and the anodic oxidation speed, it can generally be appropriately selected within a range of 50 cm to 500 cm.

  As shown in FIG. 2A, the portion of the surface 21 s of the power supply drum 21 of the first electrolysis unit 11 that is in close contact with the strip 1 is made of a conductive material. The portion that does not adhere is made of a non-conductive material. The width W1 of the conductive material with which the belt-like object 1 of the power supply drum 21 is in close contact need not necessarily coincide with the width of the belt-like object 1, and may be a width that allows the meandering of the belt-like object 1. The width of the conductive material is preferably 50 to 100%, more preferably 70 to 90% with respect to the strip 1.

  2B, on the surface 22s of the power supply drum 22 of the second electrolysis unit 12, the short direction end 1t of the strip 1 protected by the protective member 60 in the first electrolysis unit 11 is in close contact. The region including is formed of a conductive material, and other portions are formed of a non-conductive material. In FIG. 2B, the width (W2-W1) of the portion 22d where the conductive material is formed in the power supply drum 22 and the width of the portion protected by the protective member 60 in the first electrolysis unit 11 are substantially the same. In the first electrolysis unit 11, it is possible to pass a current that can satisfactorily anodize the second surface 1 b in the second electrolysis unit 12 to the portion protected by the protective member 60 in the first electrolysis unit 11, and If the meandering of the strip 1 can be allowed, the width of 22d is not particularly limited. In FIG. 2A and FIG. 2B, in the front view of each power supply drum, the hatched portion 21d is shown as a region formed of a conductive material, and the other region 21i is shown as a region formed of a nonconductive material. is there.

Since the surface current density of anodic oxidation is generally 500 mA / cm ² or less, the conductive portion 21 d of the first power supply drum 21 needs to be made of a material that can supply power with the same surface current density. On the other hand, the conductive portion 22d of the second power supply drum 22 is necessary for power supply due to the width of the portion of the second surface 1b of the strip 1 where anodization is performed and the width 22d of the conductive portion of the second power supply drum 22. Different surface current densities. When the former width is W1, the latter width is W2-W1, and the surface current density of anodic oxidation is I, the current density J applied to the conductive portion of the second power supply drum 22 is a value obtained by the following equation. .
J = 0.5 × I × W1 / (W2-W1)

  Examples of the material suitably used for the conductive portion of the surface 20s of the power supply drum include metals, conductive plastics, conductive rubbers, and the like. The conductive plastics and conductive rubbers have a soft surface, and the band 1 adheres to the surface. It is preferable because the surface is hardly damaged. As the conductive plastic and the conductive rubber, those made conductive by mixing carbon into a general general-purpose material can be used. These thicknesses vary depending on the desired strength and conductivity, but are preferably about 0.1 mm to 10 mm.

  When the material suitably used for the conductive portion of the surface 20 s of the power supply drum is a metal, the aging of the contact resistance may occur due to the formation of an oxide film by the mist of the electrolytic solution L. Is preferred.

  As the nonconductive material used for the surface 20s of the power supply drum, a nonconductive plastic, a nonconductive rubber, or the like is preferable.

  As described above, in the present embodiment, a case where the region where the anodized film is in close contact with the surface of the power supply drum 22, which is a preferable embodiment, is made of a non-conductive material, is required. Depending on the characteristics to be performed and the degree of the influence of the anodic oxidation on the anodized film in the second electrolysis unit 12, the adhesion surface of the anodized film may be made conductive.

  However, as in the present embodiment, in the aspect in which the portion where the anodized film of the strip 1 is in close contact with the power supply drum 22 of the second electrolysis unit is a non-conductive material, the first surface An electric field is not applied to the anodized film formed on 1a, and adverse effects such as dielectric breakdown due to the occurrence of sparks can be prevented.

  The shape of the counter electrode 30 is preferably a curved plate shape that is substantially concentric with the power supply drum 20. Moreover, it is preferable that the counter electrode 30 has many through-holes. However, when the counter electrode 30 is located in the electrolytic solution L in a completely equidistant arrangement with respect to the power supply drum 20, in the portion where the strip to be anodized is in contact with the electrolytic solution L and the portion separated from the electrolytic solution L It is preferable to make the effective electric field small because current concentration due to electric field concentration causes anodic oxidation failure. In order to reduce the effective electric field in this way, it is easy to use the electrolytic solution resistance, an arrangement that increases the distance between the power supply drum and the counter electrode in the liquid contact portion and / or the liquid separation portion, An arrangement in which the counter electrode is not provided in the liquid contact portion and / or the liquid separation portion, or an arrangement using them in combination can be employed.

FIG. 3 shows a counter electrode arrangement in which the distance between the power supply drum 20 and the counter electrode 30 is increased in the liquid contact portion and the liquid separation portion. That is, the distance P ₁ between the power supply drum 20 and the counter electrode 30 in the portion where the strip 1 supported by the power supply drum 20 contacts the electrolyte L and the power supply drum in the portion where the strip 1 separates from the electrolyte L. the distance P ₂ of the 20 and the counter electrode 30 is made larger than the distance P3 of the feeding drum 20 and the counter electrode 3 in the central part that immersion in the electrolytic solution L of the web 1. Here, the distances P _{1 to} P ₃ are the shortest distances connecting the power supply drum 20 and the counter electrode 30. By adopting such a counter electrode arrangement, the effective electric field can be reduced, and the occurrence of defective anodic oxidation can be suppressed.

  Moreover, generation | occurrence | production can also be suppressed by devising the shape of the counter electrode 32 (30) also about the anodic oxidation nonuniformity and anodic oxidation defect in the transversal direction (rotation axis direction) of the strip | belt-shaped object 1. FIG. The anodic oxide film (insulating layer) is preferably uniform, and it is desirable to avoid unevenness in the film thickness.

  In the 2nd electrolysis part 12, since it supplies with electric power from end 1t, the energization distance inside a strip becomes long and the electrical resistance resulting from a strip becomes large, so that it approaches the center. As a result, the voltage drop increases, and the current density decreases in the center. Since the film thickness of the anodized film is substantially proportional to the amount of electricity supplied, the film thickness may decrease toward the center in the short direction of the strip. As a result, there is a possibility of causing anodic oxidation unevenness or poor anodic oxidation in the short direction of the strip 1.

  As a configuration for suppressing such anodic oxidation unevenness and defects, the distance Dc between the power supply drum 22 and the counter electrode 32 in the portion where the power supply drum 22 and the short-side end 1t of the strip 1 are in close contact with each other in the second electrolysis unit 12. A mode in which the distance is larger than the distance Ds between the power supply drum 22 and the counter electrode 32 in the central portion in the rotation axis direction of the power supply drum 22 is exemplified (FIG. 4).

  FIG. 4 shows a configuration in which the distance from the counter electrode 32 gradually increases from the center in the short direction to the end 1t, but is not limited to this mode.

  When the distance between the strip 1 forming the anodic oxide film and the counter electrode 32 is large, the voltage drop due to the resistance of the electrolyte L existing therebetween becomes larger, so that the current density can be reduced. Therefore, by adopting such a shape, the electrolytic solution resistance decreases as the resistance increases due to the strip 1, so that a more uniform current density distribution is obtained as a whole. That is, the reduction of the film thickness toward the center in the edge direction of the strip 1 is suppressed and alleviated to reduce anodic oxidation unevenness, and the electrolytic concentration at the end is suppressed to reduce anodization failure. Can do.

  Further, as another aspect for suppressing anodic oxidation unevenness and defects, the width W4 in the short direction of the strip 1 of the counter electrode 32 is protected by the protective member 60 of the strip 1 in the second electrolysis unit 12. An embodiment smaller than the width W1 of the non-existing portion is exemplified (FIG. 5).

  By adopting such a shape, the distance from the counter electrode 32 becomes longer at the end 1t of the strip 1 where the current density tends to be high, and the voltage drop due to the resistance of the electrolyte L existing therebetween is larger. Therefore, the energization current density can be reduced. Therefore, similarly to the above, the decrease in film thickness toward the center in the edge direction of the strip 1 is suppressed and alleviated to reduce anodic oxidation unevenness, and the electrolytic concentration at the end is suppressed to anodize. Defects can be reduced.

  The protective member 60 is non-conductive at least in contact with the electrolytic solution L. 6A and 6B are schematic cross-sectional views in the drum radial direction of the power supply drum at the close contact portion of the strip 1.

  When all of the protective members 60 are non-conductive, as shown in FIG. 6A, the contact with the conductive portion 22d of the power supply drum 22 at the short-side end 1t that is the power supply portion to the strip 1 is Only the surface of the power supply drum 22 is provided. In the configuration in which the portion where the protective member 60 is in contact with the electrolytic solution L is non-conductive, the occurrence of an electrochemical reaction on the surface of the protective member 60 can be suppressed, and the original object of the strip 1 It is possible to satisfactorily prevent the electrolyte L from entering the back surface.

  On the other hand, in the second electrolysis unit 12, since the contact area with the conductive portion 22d of the power supply drum used for the end power supply is small, the contact resistance with the strip 1 becomes smaller when the contact area is as large as possible. Further, it is preferable because a change in the contact area due to disturbance is suppressed and continuous and stable power feeding is possible.

  As shown in FIG. 6B, the contact portion of the protective member 60 with the electrolyte L is made of the non-conductive portion 61, and the portion that contacts the end face of the strip 1 at the short-side end portion 1t is taken from the conductive portion 62. By using the protective member 60 as described above, the intrusion of the electrolytic solution L to the back surface of the band 1 which is the original purpose is prevented, and at the same time, as indicated by the arrows in the figure, the protective member 60 is removed from the power supply drum 22. Since it becomes possible to supply power to the strip 1 via the conductive portion 62, the power supply area to the strip 1 can be increased. In the embodiment shown in FIG. 6B, the energization area is considered to be approximately twice as large as that in the embodiment of FIG. 6A. Moreover, since the part where the protective member 60 contacts the electrolytic solution L is made of a non-conductive material, it also has an effect of suppressing an electrochemical reaction on the surface of the protective member 60.

  In the protective member 60, the protective member 60 in FIG. 6A and the nonconductive portion 61 in FIG. 6B are preferably nonconductive rubber or nonconductive rubber, and the conductive portion 62 is preferably metal. A more preferable configuration for the protective member 60 includes non-conductive rubber or a metal foil covered with non-conductive rubber. In order to further improve water tightness, a material having adhesiveness may be applied to the side that is in close contact with the strip 1.

  Depending on the diameter of the power supply drum 20, it is preferable to apply tension to the co-traveling protection member 60 in order to ensure water tightness. In the case of a large diameter power supply drum, a non-conductive rubber belt with a steel core is used. More preferably, it can be used.

  The metal strip 1 that can be anodized by the anodizing apparatus 10 is not particularly limited as long as both surfaces can be anodized, and may be composed of a single metal or an alloy, or a plurality of types of metals in the thickness direction. It may be a composite metal band in which layers are laminated.

  As described in the background art section, in a thin metal substrate having a high resistance per unit cross-sectional area, a substrate on which only one side of an anodic oxide film is formed is a thermal stress due to heating of the device layer film formation or an anode Warping is likely to occur due to changes in internal stress of the oxide film, and handling is difficult. Therefore, the anodizing apparatus 10 can be effectively used for anodizing a thin metal strip having a high resistance per unit cross-sectional area.

  The thickness of the strip 1 is generally in the range of 0.02 to 0.5 mm. Even in the case of a strip having a high resistance per unit width in such a unit width, the strip can be closely supported on the power supply drum, and power can be directly fed from the back of the strip, so that the anodic oxide film can be fed at a higher speed. Can be formed.

  Examples of the metal that can be anodized include aluminum, Nb, Ta, Ti, and the like. For example, in the case of aluminum, generally an aluminum alloy having a purity of 90% or more is preferably used. When an anodized film is used as an insulating film, it is preferable not to include metal Si particles as a precipitate.

  Preferred examples of the metal to be combined with the anodizable metal as a composite metal strip include iron, carbon steel, stainless steel, Ti and the like, and a composite having an Al clad material on both sides of these metal strips. A metal strip is preferable as a substrate material with an insulating layer for an optical device or the like.

  Examples of the electrolyte L include aqueous solutions of acids such as sulfuric acid, phosphoric acid, chromic acid, oxalic acid, tartaric acid, malonic acid, sulfamic acid, benzenesulfonic acid, and amidosulfonic acid, or a mixture thereof. However, what is necessary is just to select an optimal thing in order to obtain desired quality. The concentration and temperature of the electrolytic solution can also be appropriately selected.

  Further, a flow means 90 is provided for moving the electrolyte L in the gap d between the counter electrode 30 and the belt-like object 1 tightly supported by the power supply drum 20 from the gap d. The circulation means 90 includes an introduction portion 92 provided in the counter electrode 30 and a supply portion 91 that moves the electrolytic solution L in the gap d through the introduction portion 92 from the gap d.

  The introduction part 92 is for introducing the electrolytic solution L of the electrolytic cell 40 into the gap d and discharging the electrolytic solution L in the gap d from the gap d. The introduction part 92 is, for example, a nozzle that is attached to an opening provided in the counter electrode 30. As shown in FIG. 3, the introduction portion 92 is provided at the lowermost portion of the counter electrode 30 along a direction parallel to the rotation shaft 20 c of the power supply drum 20.

  The introduction portion 92 is not particularly limited to the nozzle as long as the electrolytic solution L of the electrolytic cell 40 can be introduced into the gap d.

  The supply unit 91 supplies the electrolytic solution L in the electrolytic cell 40 to the introducing unit 92, and the electrolytic solution L in the electrolytic cell 40 is put into the gap d through the introducing unit 92, for example, as shown in FIGS. It is to be introduced. The supply unit 91 is not particularly limited in configuration as long as the electrolytic solution L in the electrolytic cell 40 can be supplied to the introduction unit 92, and the electrolytic solution L in the gap d and the electrolytic solution in the electrolytic cell 40 are not limited. L may be circulated. For example, a pump or the like is used for the supply unit 91.

  In the circulation means 90, the supply unit 91 introduces the electrolytic solution L in the electrolytic cell 40 into the gap d through the introduction unit 92. For example, as shown in FIG. The electrolyte L is discharged from the first opening L1 of the gap d by moving in a direction substantially parallel to the longitudinal direction of the strip 1 along the peripheral surface of the power supply drum 20. As a result, the electrolyte L in the gap d whose temperature has risen can be removed from the gap d, and the electrolyte L that is not affected by heat generation in the electrolytic cell 40 can be supplied to the gap d.

  Next, the operation of the anodizing apparatus 10 will be described with reference to FIGS. 1 and 3. First, the strip 1 wound in a roll shape is fed out from the unwinding roll 71 and is closely adhered to and supported by the power supply drum 21 (20) of the first electrolysis unit 11, and then the second electrolysis via the guide roll G. The power supply drum 22 (20) of the unit 12 is closely attached and wound around the winding roll 81.

  Similarly, in each electrolytic section, the protective member 60 wound in a roll shape is fed from the unwinding rolls 72 and 73 and wound around the winding rolls 82 and 83 after being closely supported by the power supply drum 20. . At this time, the protection member 60 overlaps the short-side end 1t of the belt-like object 1 that is closely supported by the power supply drum 20 and the portion of the power supply drum 20 where the belt-like object 1 does not adhere, by the protection member 60. In this manner, the power supply drum 20 is closely attached.

  In the first electrolysis unit 11, the protective member 60 has an area where the covering portion on the anodized surface can be anodized by feeding power from the end portion in the second electrolysis unit. It is important to overlap.

  Further, the protective member 60 needs to be sufficiently adhered so that the electrolyte solution can be prevented from entering the back surface of the belt 1.

  In the first electrolysis unit 11, the positioning when the belt-shaped object 1 is closely attached is performed such that the conductive portion 21 d of the power supply drum 21 is positioned on the back surface of the portion to be anodized. In the second electrolysis unit 12, the portion of the first electrolysis unit 11 that is covered with the protective member 60 and remains unanodized is positioned so as to be in close contact with the conductive unit 22 d of the power supply drum 22. is important.

  In this state, a part of the power supply drum 20, for example, the center of the drum is immersed in the electrolytic solution L in the electrolytic cell 40. Here, the drive unit is driven, and the belt 1 and the protective member 60 closely adhered to the power supply drum 20 in synchronism with the peripheral speed of the power supply drum 20 are caused to co-run in the electrolyte L, and the power source 50 of the anodizing device 1 is turned on. And a current flows between the power supply drum 20 and the counter electrode 30. At this time, in the circulation means 90, the supply unit 91 introduces the electrolytic solution L in the electrolytic cell 40 into the gap d through the introduction unit 92, and discharges the electrolytic solution L in the gap d from the gap d.

  As a result, an anodic oxide film is formed on the surface of the strip 1 that is not in close contact with the power supply drum 20.

  Further, since both end portions 1t in the short direction of the strip 1 are completely protected by the protective member 60, the anodizing apparatus 10 performs anodization on the strip in which dissimilar metals such as cladding materials are joined. Even in this case, a side reaction due to the local battery action does not occur. And it becomes possible to suitably prevent the formation of the anodic oxide film on the adhesion surface side between the power supply drum 20 and the belt-like object 1, and due to the stable contact resistance, the film thickness uniformity is high at high speed on each side of the metal substrate, In addition, an anodized film having a good surface state can be formed.

  Furthermore, by providing the intrusion prevention means, the electrolytic solution L is prevented from flowing into the opening area where the belt-like object 1 is not wound around the power supply drum 20, thereby suppressing deterioration of the power supply drum 20. be able to. Thereby, it is possible to stably form an anodized film having a high film thickness uniformity and a good surface state.

As shown in FIG. 7 and FIG. 8, the power supply drum 20 is provided with a recess (notch portion) in which the strip 1 travels inscribed and a recess in which the protection member 60 travels inscribed. In FIG. 8, W ₃ and D ₃ are the entire width and drum diameter of the power supply drum 20, W ₂ and D ₂ are the outer width and drum diameter at which the protective member 60 contacts the power supply drum 20, and W _p and D _p are The width of the strip 1 and the drum diameter are indicated, and W ₀ indicates the width of the conductive material portion of the power supply drum. By setting the relationship between the drum diameters to D ₃ > D ₂ > D _p , meandering is suppressed by the recesses provided in the power supply drum 20 and the protective member 60 that overlaps the belt 1, and the relationship between the drum widths described above. When W ₃ > W ₂ > W _p > W ₁ , the band 1 is overlapped with the protective member 60 with good water tightness, and the penetration of the electrolyte into the back surface of the band 1 is more effective. Can be prevented. Here, the power supply drum 20 is shown with a recess in which the belt-like object 1 travels inwardly and a recess in which the protection member 60 inwardly travels. However, only the recess in which the belt-like object 1 travels inscribed is shown. It is good also as an aspect which provides.

  The anodizing device 10 may have a mode in which a guide roller G <b> 2 that presses the protective member 60 against the power supply drum 20 is provided. This will be described with reference to FIGS. 9 and 10. FIG. 9 is a schematic sectional view showing an embodiment of an anodizing apparatus provided with a guide roller G2, and FIG. 10 is a schematic front view of a power supply drum provided with the guide roller G2 in FIG. As shown in FIGS. 9 and 10, in this anodizing apparatus, a protective member 60 that overlaps both ends of the strip 1 in the short direction and a portion where the strip 1 does not adhere is pressed against the power supply drum 20. Guide rollers G2 are provided at four locations. The surface of the guide roller G2 is insulated. By providing such a guide roller G2, the band 1 is overlapped with water tightness by the protective member 60, so that the electrolytic solution enters the back surface of the band 1 (the surface in close contact with the power supply drum). Can be blocked.

  In addition, although the aspect which provided the guide roller G2 only in the part immersed in the electrolyte solution L of the power supply drum 20 is shown here, the guide roller G2 is the part which is not immersed in the electrolyte solution L of the power supply drum 20 It is good also as an aspect provided. For example, even if the guide roller G2 is provided only in a portion (near the unwinding and winding roll of the protection member 60) of the power supply drum 20 that is not immersed in the electrolyte L, the meandering of the protection member 60 can be prevented. It is possible to overlap 1 and the part which the strip | belt-shaped object 1 does not contact | adhere with sufficient watertightness.

  As the power supply waveform at the time of anodization, a direct current is generally used, but an optimal waveform such as an alternating current waveform in which direct current is superimposed can be selected. The current density during anodization can be freely selected. For example, it may be a constant value during the processing time, or the current density may be gradually increased. The electrolytic method at the time of anodization may be a constant current method or a constant voltage method.

  In the anodic oxidation, an oxide film is formed by setting a positive potential to the counter electrode, and it is preferable to apply a negative voltage to the ground as the potential of the counter electrode. As a result, the potential of the strip can be made close to the ground potential, and the entire facility for handling the strip by roll-to-roll can be set to the ground potential. In the opposite case, it is necessary to make the entire facility have a potential with respect to the ground, which is not only dangerous, but also an abnormal discharge such as a spark between the strip and the facility, which may cause a product defect.

  In particular, it is more preferable that the strip is made to coincide with the ground potential, and both the positive electrode and the negative electrode output of the electrolysis power supply have an insulating output with respect to the ground. Thereby, the abnormal discharge of a strip | belt-shaped object and an installation can be prevented completely in roll-to-roll parts other than an electrolytic cell. This is schematically shown in FIG. In order to make the strip 1 coincide with the ground potential, it is possible to place at least one conductive roll G3 in a roll-to-roll portion other than the electrolytic cell 40 and electrically connect the roll to the ground.

  Furthermore, when the electrolysis method (the method in which a current flows between the power supply drum and the counter electrode) is a constant current method or a constant voltage method, it is preferable to monitor the voltage of the power supply drum with respect to the ground potential. As a result, the watertightness of the protective member described above is temporarily reduced to cause a leakage current, or the contact resistance between the belt and the power supply drum is changed. Quality fluctuation factors can be monitored.

  In the previous stage of the anodizing treatment, the strip is usually subjected to a washing treatment. This cleaning treatment is for removing dirt on the aluminum surface, and a known method such as immersing in an alkaline solution having an effect of removing dirt while dissolving the natural oxide film is used. Moreover, you may perform a roughening process as needed. This roughening treatment is for improving the adhesion with the layer provided on the surface of the anodic oxide film by providing irregularities on the surface, mechanical roughening method, chemical roughening method, It is carried out by an electrochemical roughening method or a known method combining them. Also in the anodizing apparatus of the present invention, a pretreatment tank for performing such pretreatment and a water washing tank for washing and removing the pretreatment liquid may be provided upstream of the unwinding roll 71 or the like.

On the other hand, the band-like material on which the AAO film after the anodizing treatment is formed is usually subjected to a drying treatment after passing through a washing layer for washing and removing the electrolytic solution.
As described above, the anodizing apparatus 10 is configured.

  The anodizing apparatus 10 includes a first electrolysis unit 11 that anodizes the first surface 1a of the strip 1 and a second electrolysis unit 12 that anodizes the second surface 1b of the strip 1. In the first electrolysis unit 11 and the second electrolysis unit 12, the surface opposite to the anodized surface of the strip 1 can be closely supported, and the power supply drum 20 is used to feed power to the strip 1 from the surface. 1 a and 1 b of the first surface 1a and the second surface 1b, and at least the short-side end 1t of the strip 1 that is in close contact with the power supply drum 20 immersed in the electrolyte L, and the power supply drum A protective member 60, which is formed by overlapping and covering a portion of the surface 20s where the belt-like object does not adhere, protects the end 1t from the electrolytic solution, and at least a portion in contact with the electrolytic solution is non-conductive. The feeding drum 21 of the first electrolysis unit 11 is in close contact with the strip 1 The portion 21d is formed of a conductive material, and the power supply drum 22 of the second electrolysis unit is electrically conductive with the portion 22d where the short-side end of the belt-like material protected by the retaining member in the first electrolysis unit is in close contact. It is made of material. According to such a configuration, the short-side end portion of the belt-like material that remains without being anodized by being covered with the protective member in the first electrolysis unit 11 is used as a power feeding unit in the second electrolysis unit 12. Can do.

  Further, the anodizing device 10 is formed by covering the end portion 1t of the strip 1 in the short direction and the portion where the strip of the power supply drum surface 20s is not in close contact, and covering the end portion with the electrolytic solution L. Since the protective member 60 is provided to protect the belt 1 from being in contact with the electrolyte solution L during the anodic oxidation, it is possible to prevent electrolysis between the power supply drum and the strip top. Since the infiltration of the liquid can be prevented, an anodic oxide film having a high film thickness uniformity and a good surface condition can be formed on the first surface 1a of the belt-like material with a stable contact resistance.

  Moreover, in the 1st electrolysis part 11 and the 2nd electrolysis part 12, since the strip | belt-shaped object 1 is closely_supported by the electric power feeding drum, since it can supply electric power directly from the back surface of a strip | belt, it is a level which can ignore a voltage drop and heat_generation | fever. Therefore, even if it is a belt-like material having a high resistance per unit length, the film thickness is high, the film thickness is uniform, and the surface condition is good. An oxide film can be formed.

  Furthermore, in the aspect which made the part which the part in which the anodic oxide film of the strip | belt-shaped object 1 was formed in the electric supply drum 22 of the 2nd electrolysis part made into the nonelectroconductive material, the anodic oxide film formed in the 1st surface In addition, no electric field is applied, and adverse effects such as dielectric breakdown due to the occurrence of sparks can be prevented.

  By using the anodizing apparatus 10, when the first surface 1a of the strip 1 is anodized, an anodized film and a portion that is not anodized are continuously formed in the longitudinal direction of the strip 1 When the second surface is anodized, power is supplied through the non-anodized portion of the first surface, and an anodized film is formed on the second surface. A metal substrate with an insulating layer having an anodized film on both surfaces of a metal substrate having a high resistance per area can be produced.

  A continuous anodizing device 100 including a plurality of the anodizing devices 10 is shown in FIG. The continuous anodizing apparatus 100 has a configuration in which four first electrolysis units 11-1, a first electrolysis unit 11-2, a second electrolysis unit 12-1, and a second electrolysis unit 12-2 are arranged in series. . In the aspect provided with the some 1st electrolysis part 11 and the 2nd electrolysis part 12 like the continuous anodic oxidation apparatus 100, the system which arrange | positions the same kind of electrolysis part in series is preferable.

  As FIG. 12 shows, washing | cleaning processes, such as water washing, may be included between the 1st electrolysis part 11 (11-2) and the 2nd electrolysis part 12 (12-1). Immediately after the first surface 1a is anodized in the first electrolysis section, the surface of the band-like material has an electrolytic solution or a solid material derived from the electrolytic solution. In particular, in the second electrolysis unit 12 (12-1, 12-2), power is supplied from this portion while the state where they are attached to the portion of the first surface 1a that has not been anodized is: Since there is a possibility that problems such as an increase in contact resistance, occurrence of side reactions, and electric leakage may occur, it is preferably removed beforehand by washing with water.

  In FIG. 12, the strip 1 is fed from the unwinding roll 71 and passes between the first electrolysis units 11-1 and 11-2 and the second electrolysis units 12-1 and 12-2 via the guide roll G. It is comprised so that it may wind up by the winding roll 81, and the protection member 60 is sent out from the unwinding rolls 72-1, 72-2, 73-1, 73-2 for every electrolysis part, and the winding roll It is comprised so that it may be wound up by 82-1, 82-2, 83-1, 83-2. In addition, about the protection member 60, it is good also as an aspect which uses the protection member 60 collectively in all the electrolysis parts instead of the aspect wound up for every electrolysis part.

  Although not shown, a pretreatment layer for pretreating the strip 1 is installed between the unwinding roll 71 and the guide roll G, and a drying tank 13 for drying is installed after the washing tank. Also good.

Although the anodic oxidation of aluminum depends on the electrolytic solution and the electrolysis conditions, the Coulomb efficiency of electrolytic oxidation is about 3 C / (cm ² · μm), and about 2 μm / min per energization current with a surface current density of 100 mA / cm ² . It becomes the formation speed. At this time, assuming that the surface current density is D1 (mA / cm ² ), the electrolysis time is T (min), and the necessary AAO film thickness is H (μm), T = 50 × H / D1 (min). . If the formation speed is S, S = 0.02 × D1, and therefore T = H / S. Assuming that the electrolyte immersion length of the strip is L (m) and the travel speed of the strip is LS (m / min), LS = L / T = 0.02 × L × D1 / H = L × S / H Yes, the traveling speed LS is proportional to L and D1 or S, and inversely proportional to H.

  FIG. 13 is a graph showing the relationship between the traveling speed and the AAO formation speed when the AAO thickness H is 10 μm. (A), (b), and (c) in the figure are cases where the electrolytic cell length L is 5, 10, and 15 m, respectively. The traveling speed LS can be increased in proportion to the AAO formation speed S. In the case of the present invention, the electrolytic cell length L is the distance at which the power supply drum is immersed in the electrolytic solution. For example, when the diameter of the power supply drum 21 of the first electrolysis unit 11 is about 3 m, the electrolytic cell length can be set to 5 m when immersed slightly larger than the center of the drum. Since the AAO film is formed only on one side and the other side remains a metal, it can be subsequently anodized by the same drum power feeding. Therefore, if N electrolytic cells are arranged in series, the traveling speed can be increased N times.

  On the other hand, when the diameter of the second power supply drum 22 is about 3 m, the electrolytic cell length can be set to 5 m when the power supply drum 22 of the second electrolysis unit 12 is immersed slightly larger than the center of the drum. Since power is supplied from the end portion, it is possible to continue anodic oxidation with the same drum power supply. Therefore, if N electrolytic cells are arranged in series, the traveling speed can be increased N times.

In the conventional electrolyzer that immerses the entire strip, it is necessary to pass an electrolytic current in the running direction of the strip from the feeding portion to the electrolytic cell as described above. At this time, when the electrolytic current flowing in the running direction per 1 cm width of the strip is D2 (A / cm), it is necessary to grow AAO of the necessary thickness on the strip area immersed in the electrolytic cell per unit time. Current is calculated from D2 = LS × H × [Coulomb efficiency] × 100/60 = 5 from the traveling speed LS (m / min), the AAO thickness H (μm), and the Coulomb efficiency 3 C / (cm ² · μm). × LS × H. Therefore, D2 becomes a current proportional to the traveling speed and the AAO thickness regardless of the AAO formation speed and the electrolytic cell length. Since the value shown on the right vertical axis in FIG. 13 is an AAO thickness of 10 μm, D2 = 50 × LS with respect to the left vertical axis LS.

  On the other hand, there is an upper limit to the current that flows from the feeding portion of the strip to the electrolytic cell. When the aluminum foil is 100 μm, even if it is sufficiently cooled by a water-cooled shower or the like, if it exceeds 150 A / cm, it is heated due to IR heat generation due to the resistance of aluminum. Runaway and increased risk of fusing. Therefore, regardless of the formation speed and electrolytic cell length in FIG. 13, the electrolysis current in the width direction needs to be 150 A / cm or less, that is, the traveling speed is 3 m / min or less. Since the IR heat generation and fusing limit current of the strip are determined by the resistance per unit cross-sectional area, the limit current per 1 cm width becomes smaller as the aluminum foil becomes thinner. Further, in a clad material in which a high-strength but high-resistance metal such as steel, stainless steel, and Ti is combined with thin aluminum, the limit current is similarly reduced, and the traveling speed needs to be reduced.

DESCRIPTION OF SYMBOLS 1 1st band 1a 1st surface 1b 2nd surface 1t Short direction direction edge part 11, 11-1, 11-2 of 1st electrolysis part 12, 12-1, 12-2 2nd electrolysis part 20, 21, 22 Feeding drums 20s, 21s, 22s Feeding drum surface 21d A portion 22d of the feeding drum of the first electrolysis unit that is in close contact with the belt-like material The short side protected by the protective member at the first electrolysis unit in the feeding drum of the second electrolysis unit Parts 30, 31, 32 in which direction end portions are in close contact with each other 40 Electrode tank 50 Power supply 60 Protective member 10, 100 Anodizing device 90 Flow means 91 Supply portion 92 Introduction portion L Electrolytic solution G Guide roller G2 Pressure contact guide roller Dc Power supply Distance Ds between the power supply drum and the counter electrode at the center in the rotation axis direction of the drum Distance W1 between the power supply drum and the counter electrode at the portion where the end in the short direction is in close contact. The lateral direction of the width of the web width W4 counter electrode portions unprotected I

Claims (19)

An anodizing device for anodizing both sides of a metal strip that is an anodizable metal on both sides,
A first electrolysis unit for anodizing the first surface of the strip, and a second electrolysis unit for anodizing the second surface of the strip with the anodized film formed on the first surface. And
The first electrolysis unit and the second electrolysis unit are capable of closely supporting a surface opposite to the anodized surface of the strip, and feeding a power drum to feed the strip from the surface;
A counter electrode provided to face the power supply drum;
An electrolytic cell storing an electrolytic solution for immersing a part of the power supply drum and the counter electrode that tightly supports the belt-like object; and
At least a short-side end portion of the on-band object that is tightly supported by the power supply drum immersed in the electrolytic solution and a portion of the surface of the power supply drum where the belt-shaped object does not adhere are overlapped and covered. The end portion is protected from the electrolytic solution, and at least a portion in contact with the electrolytic solution has a non-conductive protective member,
The power supply drum of the first electrolysis unit is formed of a conductive material at a portion where the belt-like object is in close contact, and the power supply drum of the second electrolysis unit is protected by the protective member in the first electrolysis unit. An anodic oxidation apparatus characterized in that a portion where the end in the short-side direction of the belt-like material that has been formed is in close contact is formed of a conductive material.   In the second electrolysis section, the distance between the power supply drum and the counter electrode at a portion where the power supply drum and the strip-shaped end portion of the belt-like object are in close contact with each other is such that the power supply at the central portion in the rotation axis direction of the power supply drum. The anodizing apparatus according to claim 1, wherein the anodizing apparatus is longer than a distance between the drum and the counter electrode.   3. The width of the counter electrode in the short-side direction of the strip is smaller than the width of a portion of the strip that is not protected by the protection member. The anodizing apparatus according to 1. 4. The part of the power supply drum of the second electrolysis unit, wherein the portion where the anodized film is formed in the first electrolysis unit is non-conductive. 5. Anodizing equipment. The anodizing apparatus according to claim 4, wherein at least a surface of the nonconductive portion of the power supply drum of the second electrolysis unit is formed of rubber.   The anodizing apparatus according to any one of claims 1 to 5, wherein at least a part of a portion of the protective member in contact with an end portion in a short direction of the strip is made of a conductive material. The anodizing apparatus according to claim 1, wherein one or both of the first electrolysis unit and the second electrolysis unit are arranged in series.   The continuous anodizing device according to any one of claims 1 to 7, wherein a rotating shaft of the power supply drum is lower than a liquid level of the electrolytic solution.   The anodizing apparatus according to any one of claims 1 to 8, wherein a concave portion in which the belt-like object can travel inscribed is provided on a surface of the power supply drum that closely contacts the belt-like object.   The anodizing apparatus according to claim 1, further comprising a guide roller that presses the protective member against at least the end.   In the portion where the strip supported by the power supply drum is in contact with the electrolyte and / or the portion where the strip is separated, the distance between the power supply drum and the counter electrode is determined so that the strip is immersed in the electrolyte. The anodizing device according to claim 1, wherein the anodizing device is larger than a distance between the power supply drum and the counter electrode at a substantially liquid center.   The anodizing device according to claim 1, wherein the protective member is a non-conductive rubber or a metal foil covered with a non-conductive rubber.   The anodizing apparatus according to claim 1, wherein the conductive material of the power supply drum is a conductive plastic or a conductive rubber.   The anodizing apparatus according to claim 1, wherein a potential of the counter electrode is negative with respect to the ground.   The anodizing apparatus according to claim 1, wherein the strip has the same potential as the ground, and the power source used for the anodic oxidation has an insulated output with respect to the ground.   The anodizing apparatus according to claim 14, further comprising a monitoring unit that monitors a voltage of the power supply drum with respect to the ground potential.   An anodizing device comprising a large number of the anodizing devices according to claim 1 arranged in series. A method for producing a metal substrate with an anodized film, in which both sides of a metal strip that is an anodizable metal on both sides are anodized,
When anodizing the first surface of the strip, continuously forming an anodized film and an anodized portion in the longitudinal direction of the strip,
When anodizing the second surface, power is supplied through the non-anodized portion of the first surface to form an anodized film on the second surface. A method for manufacturing a metal substrate.   The method for producing a metal substrate with an anodized film according to claim 18, wherein an anodized film is formed on both surfaces of the strip using the anodizing apparatus according to claim 1. .

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