JP2012177189A - Treatment tank and electrolytic treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic treatment device capable of preventing an electrolyte from being retained and of saving the using amount of the electrolyte even when treating a long-sized substrate, and to provide a treatment tank suitably used for the electrolytic treatment device.SOLUTION: The treatment tank 10 includes: a long-sized treatment tank body 11 in which the electrolyte L is housed, a cylindrical substrate A is immersed, and the inner surface 11a' of the bottom 11a of the tank body is bent into a circular arc shape; an electrolyte supply part 12 for supplying the electrolyte L to the treatment tank body 11; and an overflow part 13 for discharging the electrolyte L from the tank body 11. The electrolyte supply part 12 is provided above one side 11b of the tank body 11 along the longitudinal direction of the tank body 11, and the overflow part 13 is provided above the other side 11c of the tank body 11 along the longitudinal direction of the tank body 11. The electrolytic treatment device comprises the treatment tank 10 and an electrode plate immersed in the tank body 11.

Description

  The present invention relates to a treatment tank for electrolytically treating a cylindrical substrate in an electrolytic solution, and an electrolytic treatment apparatus for electrolytically treating a cylindrical substrate in an electrolytic solution.

As a method for treating the surface of the substrate, there are a film treatment such as plating and a chemical conversion treatment such as anodization.
When processing the surface of the base material, for example, as shown in FIG. 12, a processing liquid L ′ such as an electrolytic solution is supplied to the processing tank 70 from a supply pipe 71 installed at a lower part of the rectangular parallelepiped processing tank 70, While adjusting the flow of the processing liquid L ′ in the processing tank 70 by the perforated plate 72 and overflowing the processing liquid L ′ from the upper part of the processing tank 70, the cylindrical substrate A is treated with the processing liquid L in the processing tank 70. In general, the surface treatment is performed by immersing the film in '.

Further, Patent Document 1 includes a rectangular parallelepiped plating tank, an overflow section surrounding the four sides of the plating tank, a reserve tank communicating with the overflow section, and a pump for replenishing a plating solution from the reserve tank to the plating tank. There is disclosed a plating apparatus comprising: In this plating apparatus, a U-shaped perforated pipe is provided in a liquid discharge portion of a pump, and a perforated plate for partitioning the inside of the plating tank up and down is installed on the upper part of the perforated pipe. Is accommodated in the plating tank so as to be positioned above the perforated plate.
According to this plating processing apparatus, the plating solution is introduced into the plating tank by a pump, and discharged from the discharge port of the perforated pipe to the upper side of the plating tank. It is said that the flow of the plating solution can be made uniform by the upper porous plate.

JP 2009-242878 A

However, when processing the surface of a base material using the processing tank 70 as shown in FIG. 12 or the plating tank described in Patent Document 1, spots occur in the flow state of the processing liquid L ′ below the perforated plate 72. It was easy. As a result, the processing tank 70 moves from the lower part to the upper part, the flow of the processing liquid L ′ overflowing is disturbed, and the processing liquid L ′ may partially stay (generation of a staying part). When the staying portion is generated, it becomes difficult to uniformly treat the surface of the base material A.
Such a tendency is likely to occur when the substrate A has a long shape as shown in FIG. 12, and becomes more prominent as the length in the longitudinal direction becomes longer. The reason for this is considered as follows.

  Usually, the supply pipe 71 extends from the end surface of the processing tank 70 to the back toward the end surface opposite to the end surface. Therefore, the longer the substrate A is, the longer the shape of the treatment tank 70 that accommodates the substrate A is, and the longer the supply pipe 71 is in accordance with the length of the treatment tank 70 in the longitudinal direction. Since the processing liquid L ′ is extruded from the supply pipe 71 to the processing tank 70 by the pump 73, the pressure received by the processing liquid L ′ tends to vary depending on the distance from the pump 73. The longer the supply pipe 71 is, the farther away from the pump 73, the easier the pressure difference between the near side near the pump 73 and the far side away from the pump 73. Therefore, it is considered that spots are more likely to occur in the flow state of the treatment liquid L ′, and a staying portion is likely to occur.

  Further, when the base material A becomes longer, the processing tank 70 that accommodates the base material A also becomes larger, so that the apparatus becomes larger and the amount of the processing liquid L ′ used also increases.

  By the way, in recent years, articles such as an optical film having a fine concavo-convex structure with a period equal to or less than the wavelength of visible light on the surface exhibit an antireflection effect, a lotus effect, and the like, and thus its usefulness has attracted attention. In particular, a fine uneven structure called a moth-eye structure is known to exhibit an effective antireflection function by continuously increasing the refractive index from the refractive index of air to the refractive index of the material of the article. .

Examples of the method for producing an article having a fine concavo-convex structure on the surface include an imprint method in which the fine concavo-convex structure formed on the surface of the mold is transferred to the surface of a transfer target such as a base film.
As a method for producing a mold used in the imprint method, for example, a cylindrical aluminum base material is anodized in an electrolytic solution, and anodized alumina having a plurality of pores (recesses) on the peripheral surface of the aluminum base material is used. Methods of forming are known.

However, when a cylindrical aluminum substrate is anodized in the electrolytic solution using the treatment tank 70 as shown in FIG. (Electrolytic solution) Temperature spots tend to occur in L ′. The surface temperature of the base material A is easily affected by the temperature spots of the processing liquid L ′, and when the temperature spots are generated in the processing liquid L ′, the surface of the base material A is also likely to have temperature spots.
The depth of pores formed on the substrate surface by anodization is susceptible to the temperature during processing. Therefore, when temperature spots occur on the electrolyte solution or the substrate surface, a mold having a variation in the depth of pores depending on the location may be obtained. When such a mold is used and the fine concavo-convex structure formed on the surface of the mold is transferred by the imprint method, the height of the convex portion varies depending on the location, that is, the article has a variation in reflectance. .

  The present invention has been made in view of the above circumstances, and an electrolytic treatment apparatus capable of preventing stagnation of an electrolytic solution even when a long substrate is processed and further suppressing the amount of the electrolytic solution used, and to the electrolytic treatment apparatus It aims at providing the processing tank used suitably.

  The treatment tank of the present invention is a treatment tank for electrolytic treatment of a columnar base material in an electrolyte solution. A long treatment tank body in which the base material is immersed and the substrate is immersed, and the treatment tank body is electrolyzed. An electrolytic solution supply unit for supplying the solution, and an overflow unit for discharging the electrolytic solution from the processing tank body, the inner surface of the bottom of the processing tank body is curved in an arc shape, and the electrolytic solution supply unit It is provided above one side surface of the processing tank main body so as to be along the longitudinal direction, and the overflow part is provided on the other side upper portion of the processing tank main body so as to be along the longitudinal direction of the processing tank main body. Features.

Moreover, the electrolytic treatment apparatus of the present invention is an electrolytic treatment apparatus that performs electrolytic treatment of a cylindrical substrate in an electrolytic solution. The long treatment tank main body, the treatment tank main body in which the electrolytic solution is stored and the base material is immersed An electrolytic solution supply unit for supplying the electrolytic solution to the substrate, a treatment tank provided with an overflow unit for discharging the electrolytic solution from the treatment tank body, and an electrode plate immersed in the treatment tank body, The inner surface of the bottom part is curved in an arc shape, the electrolyte supply part is provided above one side surface of the treatment tank body so as to be along the longitudinal direction of the treatment tank body, and the overflow part is the length of the treatment tank body. It is provided in the other side upper part of the processing tank main body so that it may follow a direction.
Here, the electrode plate may be arranged so as to sandwich the base material immersed in the processing tank body, and may be curved so as to follow the inner surface shape of the bottom of the processing tank body.
Alternatively, the electrode plate may be disposed only at a position facing the overflow portion via the base material immersed in the treatment tank body, and the area of the electrode plate in contact with the electrolyte solution; The ratio of the area of the base material in contact with the electrolytic solution is preferably 1: 1 or less.
Furthermore, it is preferable that a rotation means for rotating the base material about the central axis of the base material is provided.
Moreover, it is preferable that the said rotation means rotates the said base material in the direction opposite to the direction where the electrolyte solution supplied from the electrolyte solution supply part flows into an overflow part.
Furthermore, it is preferable to further comprise temperature adjusting means for adjusting the temperature of the electrolytic solution by heating or cooling the electrolytic solution and cooling the electrolytic solution immediately before and during the electrolytic treatment.

The treatment tank of the present invention is suitable as a treatment tank of an electrolytic treatment apparatus that prevents the electrolytic solution from staying even when a long substrate is processed, and that can also suppress the amount of the electrolytic solution used.
In addition, the electrolytic treatment apparatus of the present invention can prevent stagnation of the electrolytic solution even when a long substrate is processed, and can also suppress the amount of electrolytic solution used.

It is a side view which shows an example of the processing tank of this invention. It is sectional drawing which follows the I-I 'line of FIG. It is sectional drawing explaining the positional relationship of the electrolyte solution supply part and base material of a processing tank. It is a side view which shows the other example of an overflow part. It is sectional drawing which shows the other example of the processing tank of this invention. It is sectional drawing which shows an example of the electrolytic processing apparatus of this invention. (A) is sectional drawing which follows the II-II 'line | wire of FIG. 6, (b) is a perspective view of the processing tank and electrode plate with which the electrolytic treatment apparatus shown in FIG. 6 is equipped. It is sectional drawing which shows the other example of the electrode plate with which an electrolytic treatment apparatus is equipped. It is sectional drawing which shows the formation process of the pore of an anodized alumina. It is a graph which shows the relationship between the time which electrolyzed in Example 1 and Comparative Example 1, and the raise temperature of the electrolyte solution in several points near a processing tank wall surface. It is a graph which shows the relationship between the time which electrolyzed in Example 1 and Comparative Example 1, and the maximum temperature difference of the electrolyte solution in several points of the longitudinal direction of a base-material surface. It is a figure which shows an example of the conventional processing apparatus, (a) It is a side view, (b) is sectional drawing which follows the III-III 'line | wire of (a).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Treatment tank]
The treatment tank of the present invention is for electrolytic treatment of a cylindrical substrate in an electrolytic solution.
FIG. 1 is a view showing an example of a treatment tank 10 according to the present embodiment, and is a side view seen from the electrolyte solution supply unit side described later. 2 is a cross-sectional view taken along the line II ′ of FIG.
In addition, the outer tank 40 which accommodates the processing tank 10 shown in FIG. 1 was added to FIG.
In the present invention, the shape of the base material to be subjected to the electrolytic treatment is a columnar shape, but may be a hollow shape (cylindrical shape) as shown in FIGS. In the present invention, the term “columnar” means that the shape as a whole including a shape such as a cylindrical shape is substantially columnar.

The processing tank 10 shown in FIGS. 1 and 2 contains an electrolytic solution L, a long processing tank body 11 in which a hollow cylindrical substrate A is immersed, and an electrolytic solution that supplies the electrolytic solution L to the processing tank body 11. The supply part 12 and the overflow part 13 which discharges the electrolyte solution L from the processing tank main body 11 are provided and comprised. In the present invention, the long refers to a shape in which the long side direction of the treatment tank body is longer than the length of the treatment tank body in the top view, for example, a substantially rectangular shape in the top view. Things.
The processing tank 10 is accommodated in the outer tank 40 as shown in FIG.

<Treatment tank body>
The treatment tank main body 11 accommodates the electrolytic solution L, and the base material A is immersed in the electrolytic solution L.
The inner surface 11 a ′ of the bottom 11 a of the processing tank body 11 in this example is curved in an arc shape so as to follow the peripheral surface (outer peripheral surface) A ′ of the base material A immersed in the processing tank body 11. Since the inner surface 11a ′ of the bottom portion 11a is curved in an arc shape, the electrolytic solution L supplied from the electrolytic solution supply unit 12 described later can flow smoothly to the overflow unit 13.
In the present invention, the “arc shape” is not limited to a perfect circle. Further, in the present invention, “curved” means that the inner surface of the bottom of the processing tank main body is curved so as to protrude to the outside of the processing tank main body.

  As the shape of the inner surface 11a 'of the bottom portion 11a, a shape such as a semicircular shape or a semielliptical shape that is smoothly bent along one direction without a bending point is preferable, but a semicircular shape is more preferable. If the shape of the inner surface 11a 'of the bottom part 11a is semicircular, the electrolyte L supplied from the electrolyte solution supply part 12 flows to the overflow part 13 while maintaining a smoother flow on the inner surface 11a' of the bottom part 11a.

  About the material of the processing tank main body 11, if it is hard to corrode with the electrolyte solution L, it will not restrict | limit in particular, For example, stainless steel, polyvinyl chloride (PVC), etc. are mentioned.

The size of the processing tank main body 11 is not particularly limited as long as it can accommodate the base material A. For example, when the base material A is disposed in the processing tank main body 11 as shown in FIG. The size of the gap S is formed between the outer peripheral surface A ′ of A and the inner surface 11a ′ of the bottom portion 11a. Specifically, the distance D from the central axis P of the substrate A to the inner surface 11a ′ of the bottom portion 11a is preferably 1.25 to 2 times the radius (r) of the substrate A.
When the shape of the inner surface 11a ′ of the bottom portion 11a is semicircular, the base A is placed in the treatment tank body 11 so that the center on the diameter of the semicircle and the central axis P of the base A overlap. It is preferable to arrange.

By the way, as described above, when forming the pores on the peripheral surface by anodizing the base material, the depth of the pores is easily affected by temperature spots on the electrolyte solution and the base material surface (outer peripheral surface). Need to reduce temperature spots.
The temperature spots on the surface of the electrolytic solution and the base material are mainly caused by the electrolytic solution staying in the processing tank. However, if the distance between the base material and the inner surface of the processing tank is narrow, the temperature spots may occur. This is presumably because when the anodization is performed, the treatment tank is easily heated by heat generation, and the surface of the base material in the vicinity of the treatment tank is directly and non-uniformly heated by the heat of the treatment tank, resulting in temperature spots. This tendency is considered to occur more easily as the distance between the base material and the inner surface of the treatment tank is shorter.

However, if the distance D from the central axis P of the substrate A to the inner surface 11a ′ of the bottom 11a is 1.25 times or more the radius (r) of the substrate A, the outer peripheral surface A ′ of the substrate A and the treatment A sufficient gap is formed between the bottom 11a of the tank body 11 and the inner surface 11a ′. Therefore, since the electrolytic solution L positioned between the base material A and the processing tank body 11 can sufficiently serve as a buffer material, even if the processing tank body 11 is heated by heat generated during anodization, the base material It can suppress that A is heated by the processing tank main body 11 directly. Therefore, temperature spots on the outer peripheral surface A ′ of the substrate A can be more effectively prevented, and pores with reduced depth variation can be formed on the outer peripheral surface of the substrate.
The distance D is preferably not more than twice the radius (r) of the substrate A. Even if the distance D exceeds twice the radius (r) of the base material A, the effect of preventing temperature spots is not limited, and the treatment tank body 11 becomes large, so that the amount of the electrolyte L used is increased. .

<Electrolyte supply unit>
The electrolytic solution supply unit 12 supplies the electrolytic solution L to the processing tank main body 11, and as shown in FIG. 1, one side surface 11 b of the processing tank main body 11 extends along the longitudinal direction of the processing tank main body 11. It is provided above. Thereby, the electrolyte L supplied from the upper side of the process tank main body 11 can move smoothly to the overflow part 13 mentioned later along the inner surface shape of this process tank main body 11. FIG. Therefore, it is possible to prevent the electrolytic solution L from being partially retained.

The electrolyte supply part 12 of the example of illustration is comprised by the supply pipe | tube 12a and the elongate discharge part 12b connected to this supply pipe | tube 12a.
The electrolyte is fed into the supply pipe 12a by a pump (not shown) or the like. And the electrolyte solution with which the supply pipe | tube 12a was filled is supplied to the discharge part 12b from the discharge outlet 121a of the supply pipe | tube 12a.

  The discharge port 121a may be formed continuously (slit) along the longitudinal direction of the supply pipe 12a or may be formed intermittently.

The tip of the discharge part 12b is immersed in the electrolytic solution L accommodated in the processing tank body 11, and the electrolytic solution L is supplied to the processing tank body 11 from the discharge port 121b of the discharge part 12b.
The discharge port 121b may be formed continuously along the longitudinal direction of the discharge part 12b, or may be formed intermittently.

As shown in FIG. 1, the longitudinal direction length (width) W _12b of the discharge portion 12b is selected by the longitudinal length (width) W _A of elongated substrate A, the length W of the discharge portion 12b _12b is preferably the substrate equal to the length W _a of a, the length W about 95% of the length of the _a base material a. If the length W _12b of the discharge portion 12b is too short relative to the length W _A of the base material A, flow of the supplied electrolytic solution L becomes uneven with respect to the longitudinal direction of the base material A from the discharge portion 12b, In places where the flow is strong and weak, it leads to cooling spots on the base material A during the electrolytic treatment and causes temperature spots. As a result, for example, when the base material A is anodized, spots are generated on the oxide film formed on the surface of the base material A.
Incidentally, if the uniform flow of the electrolyte in the longitudinal direction of the base A, the length W _12b of the discharge portion 12b need not be long.

As shown in FIGS. 3A and 3B, the electrolytic solution supply unit 12 is located above one side surface of the processing tank body 11 so that the base material A is not positioned on the extension line of the discharge port 121b of the discharge unit 12b. Is preferably provided. As a result, the electrolyte L discharged from the discharge port 121b of the discharge part 12b passes through the bottom part 11a of the treatment tank body 11 while maintaining the flow rate during discharge, and efficiently flows to the overflow part 13, so that the circulation Efficiency is improved.
As shown in FIG. 3C, when the base material A is positioned on the extended line of the discharge port 121b of the discharge portion 12b, the electrolyte L discharged from the discharge portion 12b hits the surface of the base material A. In the vicinity of the surface of the substrate A, stagnation occurs, the circulation efficiency is lowered, and temperature spots in the treatment tank tend to occur.
Here, the outer tub 40 is omitted in FIG.

  In order for the electrolyte L discharged from the discharge part 12b to maintain a uniform flow state with respect to the longitudinal direction of the processing tank body 11, a structure that can maintain a positive pressure in the electrolyte supply part 12 may be used. Thus, a uniform flow of the electrolyte L can be formed with respect to the longitudinal direction of the treatment tank body 11. In order to maintain the positive pressure, the supply pipe 12a may be provided so that the opening area of the discharge port 121a is larger than the opening area of the discharge port 121b of the discharge part 12b.

  The material of the supply pipe 12a and the discharge part 12b is not particularly limited as long as it is difficult to be corroded by the electrolytic solution L, and examples thereof include stainless steel and polyvinyl chloride (PVC).

<Overflow part>
The overflow part 13 shown in FIGS. 2 and 3 discharges the electrolyte L overflowing from the processing tank body 11 to the outside of the processing tank body 11, and extends along the longitudinal direction of the processing tank body 11. Of the other side surface 11c.
The overflow portion 13 in the illustrated example is formed by making the height of one side surface 11b and the other side surface 11c of the processing tank main body 11 different, specifically, making the other side surface 11c lower than the one side surface 11b. ing.

<Effect>
The processing tank 10 of the present invention described above supplies the electrolytic solution L from above the one side surface 11b of the processing tank main body 11, and discharges it from the upper part of the other side surface 11c. At this time, since the inner surface 11a ′ of the bottom 11a of the treatment tank body 11 is curved in an arc shape, the electrolyte L can move smoothly to the overflow portion 13 without stagnation.
Note that a pump (not shown) or the like is used when the electrolytic solution L is sent to the electrolytic solution supply unit 12, but the electrolytic solution L is sent out from the electrolytic solution supply unit 12 according to gravity. Therefore, the treatment tank 10 of the present invention, like the conventional treatment tank 70 shown in FIG. 12, supplies the electrolytic solution L ′ from the supply pipe 71 provided at the lower portion of the treatment tank 70 by the pump 73. Compared with the case of discharging upward (that is, against gravity), it is less affected by the pressure of the pump. Therefore, even if the base material A to be subjected to electrolytic treatment becomes long and the length of the treatment tank body 11 in the longitudinal direction or the electrolytic solution supply unit 12 becomes long, the pressure difference between the electrolytic solutions received from the pumps at both ends of the electrolytic solution supply unit 12 Is small.

Therefore, if the processing tank 10 of the present invention is used, it is possible to prevent the electrolytic solution L from partially staying in the processing tank main body 11, so that the outer peripheral surface A ′ of the substrate A can be uniformly subjected to electrolytic processing. In particular, if the electrolytic solution supply unit 12 is provided above one side surface of the treatment tank main body 11 so that the base material A is not located on the extended line of the discharge port 121b of the discharge unit 12b, the circulation efficiency is improved and the base material A is improved. The outer peripheral surface A ′ can be more uniformly electrolytically treated.
In particular, when anodizing an aluminum substrate, it is important to suppress temperature fluctuations on the electrolytic solution and the surface of the substrate. However, if the treatment tank 10 of the present invention is used, electrolysis in the treatment tank body 11 is performed. Since the stay part of the liquid L does not easily occur, temperature spots hardly occur. Therefore, variation in the depth of the pores formed on the outer peripheral surface A ′ of the substrate A is suppressed.

Further, since the inner surface 11a ′ of the bottom 11a of the processing tank main body 11 is curved in an arc shape, the processing tank 10 of the present invention can be reduced in volume as compared with a rectangular parallelepiped processing tank 70 as shown in FIG. . Therefore, the usage-amount of electrolyte solution can also be suppressed.
In addition, if the processing tank 10 of this invention is used, since the electrolyte solution L will flow smoothly in the processing tank main body 11, it is not necessary to provide the member which adjusts flow, such as a perforated plate.

<Other embodiments>
The treatment tank of the present invention is not limited to the treatment tank 10 shown in FIGS. For example, although the electrolyte supply part 12 of the processing tank 10 shown in FIGS. 1 and 2 is composed of a single supply pipe 12a and a discharge part 12b, the supply pipe 12a may be a multiple pipe. Further, the electrolyte solution supply unit 12 may have a tubular structure as long as the electrolyte solution L can be supplied uniformly in the longitudinal direction of the treatment tank body 11.

1 and 2, the overflow portion 13 is formed by making the other side surface 11c of the processing tank body 11 lower than the one side surface 11b. For example, as shown in FIG. A hole 13 ′ extending in the longitudinal direction of the processing tank main body 11 may be provided on the other side surface 11 c, and this may be used as the overflow portion 13. However, in this case, it is preferable to provide the hole 13 ′ at a position higher than the base material A immersed in the treatment tank body 11.
The holes 13 ′ may be continuous as shown in FIG. 4 or intermittent.
In FIG. 4, only the treatment tank main body 11, the hole 13 ′, and the base material A are shown, and the electrolytic solution supply unit is omitted.

By the way, the electrolytic solution L supplied from the electrolytic solution supply unit 12 passes through the bottom 11a of the processing tank body 11, flows to the overflow unit 13, and is discharged out of the processing tank body 11. A part of the liquid L may flow toward the electrolytic solution supply unit 12 through the liquid surface of the processing tank main body 11 without being directed to the overflow part 13, and may stay in the processing tank main body 11 to cause temperature spots. May occur.
In such a case, as shown in FIG. 5, it is preferable to install a baffle plate 15 in the vicinity of the overflow portion 13 for suppressing the flow of the electrolytic solution L back to the electrolytic solution supply unit 12 side. When the electrolytic solution L returns to the electrolytic solution supply unit 12 side, it mainly flows in the vicinity of the liquid level of the processing tank body 11, and therefore the baffle plate 15 may be immersed by about 20 to 30 mm from the liquid level.
The baffle plate 15 is preferably made of a material that is not easily corroded by the electrolytic solution L, and has some rigidity so that the baffle plate is not deformed by the flow of the electrolytic solution L, such as stainless steel or polyvinyl chloride (PVC). Can be mentioned.
In FIG. 5, the outer tank 40 is omitted.

[Electrolytic treatment equipment]
The electrolytic treatment apparatus of the present invention is an apparatus that performs electrolytic treatment on a cylindrical substrate in an electrolytic solution.
6 is a side sectional view showing an example of the electrolytic treatment apparatus 1 according to the present embodiment, FIG. 7A is a sectional view taken along the line II-II ′ in FIG. 6, and FIG. It is a perspective view of the processing tank 10 and the electrode plate 20 with which the electrolytic treatment apparatus shown in FIG. 6 is equipped.

  The electrolytic treatment apparatus 1 of this example includes a treatment tank 10 filled with an electrolytic solution L, an electrode plate 20 disposed so as to sandwich a substrate A immersed in the treatment tank body 11 of the treatment tank 10, and a base Rotating means 30 for rotating the base material A around the central axis of the material A, the processing tank 10, the outer tank 40 for receiving the electrolytic solution L overflowed from the processing tank 10, and the electrolytic solution L The storage tank 50 once stored, the flow channel 41 for flowing the electrolytic solution L received in the outer tank 40 to the storage tank 50, and the electrolytic solution L in the storage tank 50 are returned to the electrolytic solution supply unit 12 of the processing tank 10. A return passage 51 and a pump 52 provided in the middle of the return passage 51 are provided.

Hereinafter, the case where the electrolytic treatment apparatus 1 of the present invention is used as an anodizing apparatus will be described in detail.
The electrolytic treatment apparatus 1 is provided with the above-described treatment tank 10 of the present invention. As shown in FIGS. 7A and 7B, the electrode plate 20 is attached to the treatment tank body 11 of the treatment tank 10. It has a curved shape along the shape of the inner surface 11a ′ of the bottom 11a. Since the electrode plate 20 has a curved shape, the flow of the electrolytic solution L is less likely to be hindered, so that the electrolytic solution L can be moved to the overflow portion 13 more smoothly without stagnation.
In addition, the outer tank 40 was abbreviate | omitted in Fig.7 (a). Moreover, in FIG.7 (b), only the processing tank main body 11 and the overflow part 13, the electrode plate 20, and the base material A of the processing tank 10 were shown, and the other structural members of the electrolytic processing apparatus 1 were abbreviate | omitted.

The end faces 11d and 11e of the processing tank main body 11 are U-shaped as shown in FIG. Therefore, a sealing material (not shown) matching the shape is attached to the end surfaces 11d and 11e so that the electrolyte does not leak from the end surfaces 11d and 11e.
Further, on the lower side of the end faces 11d and 11e, as shown in FIGS. 6 and 7A, a support shaft 31 for supporting the base material A along the axial direction in the horizontal direction is provided as the rotating means 30. It has been.
As shown in FIGS. 6 and 7A, a pair of support shafts 31 are provided in the horizontal direction on the end surfaces 11 d and 11 e of the processing tank body 11, and each support shaft 31 is an end surface 11 d of the processing tank body 11. , 11e, and is supported rotatably with respect to the end surfaces 11d, 11e of the processing tank body 11.

A cylindrical elastic member 32 made of a resin material is inserted and provided at the end of each support shaft 31 in the treatment tank main body 11, and the base material A has outer peripheral surfaces at both ends on each elastic member 32. It is supported on the support shaft 31 so as to be placed. Each support shaft 31 is connected to a rotation drive unit (not shown) such as a motor, and the support shaft 31 is rotated in the same direction by the rotation drive unit. The base material A in contact with 32 rotates.
In particular, as shown in FIG. 7A, the rotating means 30 has a direction opposite to the direction in which the electrolyte L supplied from the electrolyte supply part 12 of the treatment tank 10 to the treatment tank body 11 flows to the overflow part 13. Further, it is preferable to rotate the substrate A. Since the flowing direction of the electrolyte L and the rotation direction of the substrate A are opposite, the flow of the electrolyte L near the surface with respect to the substrate A becomes relatively fast, and the heat generated from the substrate A during the electrolytic treatment Can be moved efficiently. When the flowing direction of the electrolytic solution L and the rotation direction of the base material A are the same, the flow of the electrolytic solution L in the vicinity of the surface of the base material A is relatively slow. It will lead to the temperature rise of the electrolyte solution L in the tank 10 whole.

  Above the support shaft 31, a current-carrying shaft 33 extending in the horizontal direction is provided through the sealing material 14 attached to the end surfaces 11d and 11e. 40 also penetrates and is exposed to the outside. The energizing shaft 33 is made of a conductive material, and is rotatably supported by the sealing materials attached to the end faces 11d and 11e. The energization shaft 33 does not have to be made entirely of a conductive material, and it is only necessary that a current can be applied to the base material A via an energization member 34 described later. Specifically, the outside of the current-carrying shaft 33 may be coated with an insulating material, and a portion having contact with the sealing material attached to the end faces 11d and 11e is coated with excellent wear resistance. It doesn't matter.

  A disc-shaped energizing member 34 is integrally provided at the end of each energizing shaft 33 in the processing tank body 11. The energization member 34 is in surface contact with both end surfaces of the hollow cylindrical base material A. Here, a power source 21 is electrically connected to the electrode plate 20 and the energization shaft 33 so that a current can be applied.

  The energizing member 34 is installed so that it can be moved forward and backward by a drive unit (not shown) that moves forward and backward such as an air cylinder in the axial direction of the energizing shaft 33 or the base material A. After the base material A is installed on the support shaft 31, the energization member 34 is brought into contact with both end faces of the base material A from both sides in the axial direction of the base material A, thereby enabling energization. In the example shown in FIG. 6, the current-carrying members 34 are provided on both end faces of the base material A. However, the current-carrying members 34 may be provided only on one end face of the base material A, and the other may be used as a pressing member. In addition, the energization member 34 does not have to be strictly in contact with the base material A at the end surface of the base material A, and may be configured to be in contact with the base material A at other positions such as the inner peripheral surface of the base material A. .

  Since the energizing shaft 33 moves forward and backward through the processing tank 10 and the outer tank 40, the energizing shaft 33 can be rotated between the energizing shaft 33 and the processing tank 10 and the outer tank 40. A sliding bearing 35 that is movably supported is provided.

The inner diameter side corners of both ends of the base material A in the illustrated example are chamfered, and tapered surfaces a are formed on a part of both end faces of the base material A, while the outer diameter side corners of the energizing member 34 are chamfered. In addition, it is preferable that a tapered surface 34a that is in surface contact with the tapered surface a of the substrate A is formed, and the inclination of both is set to the same gradient. When the taper surface a of the substrate A and the taper surface 34a of the energization member 34 are brought into surface contact with each other, they can be brought into electrical close contact with each other, and the substrate A or the energization member 34 side rotates. The rotation can be transmitted by the contacted resistance and can be rotated in synchronization.
With such a structure, the contact area is large, and the effects of slipping and wear when rotating are reduced, so that stable current supply is possible.

  In addition, the energization shaft 33 to which the energization member 34 is connected rotates in synchronization with the base material A, so that the energization shaft 33 and the power source 21 are in electrical contact with a connector (not shown) capable of rotational power feeding (not shown). It is connected. There are a rotary connector, a slip ring, and the like as a connector capable of rotating power supply. However, the rotary connector is preferable because of good current stability during rotation. Further, the energization member 34 may be energized by bringing it into surface contact with only one end surface of the substrate A.

The outer tank 40 accommodates the processing tank 10, and as shown in FIGS. 2 and 6, the electrolytic solution L in the processing tank 10 is discharged from the overflow portion 13 and flows to the outer tank 40. The electrolyte L received in the outer tank 40 flows down to the storage tank 50 through the flow-down channel 41.
The storage tank 50 is provided with temperature adjusting means 53 for adjusting the temperature of the electrolytic solution L by heating or cooling the electrolytic solution L, and cooling the electrolytic solution L immediately before and during the electrolytic process. The temperature adjusting means 53 in this example includes a heat exchanger 53 a that cools the electrolytic solution L and a heater 53 b that heats the electrolytic solution L, and the electrolytic solution L adjusted in the storage tank 50 is supplied by the pump 52. It returns to the processing tank main body 11 from the electrolyte solution supply part 12 of the processing tank 10 through the return flow path 51.
The heat exchanger 53a includes a heat exchanger using water, oil, or the like as a heat medium, and the heater 53b includes an electric heater. Both are preferably coated so that problems such as corrosion do not occur even when immersed in the electrolyte L.

<Effect>
The electrolytic treatment apparatus 1 of the present invention described above includes the treatment tank 10 of the present invention. Therefore, the electrolytic solution L is less likely to stay in the processing tank body 11 of the processing tank 10.
In addition, when returning the electrolyte solution L from the storage tank 50 to the electrolyte solution supply part 12, the pump 52 is used, but the electrolyte solution L is sent out from the electrolyte solution supply part 12 to the process tank main body 11 according to gravity. Accordingly, the electrolytic treatment apparatus 1 of the present invention is configured to remove the electrolytic solution L ′ from the supply pipe 71 provided at the lower portion of the treatment tank 70 by the pump 73 like the conventional treatment tank 70 shown in FIG. Compared with the case of discharging upward (that is, against gravity), it is less affected by the pressure of the pump. Therefore, even if the base material A to be subjected to electrolytic treatment becomes long and the length of the treatment tank body 11 in the longitudinal direction or the electrolytic solution supply unit 12 becomes long, the pressure difference between the electrolytic solutions received from the pumps at both ends of the electrolytic solution supply unit 12 Is small.

Therefore, the electrolytic treatment apparatus 1 of the present invention can prevent the electrolytic solution L from partially staying in the treatment tank body 11 of the treatment tank 10, so that the outer peripheral surface of the substrate A can be subjected to uniform electrolytic treatment. .
In particular, when anodizing an aluminum base material, it is important to suppress temperature fluctuations on the electrolyte solution and the surface of the base material. Since the retention part of the electrolyte solution L hardly occurs, temperature spots are hardly generated. Therefore, variation in the depth of the pores formed on the outer peripheral surface of the substrate A is suppressed.

Moreover, since the bottom part of the processing tank main body 11 is curving in circular arc shape, the electrolytic processing apparatus 1 of this invention can reduce a volume compared with the rectangular parallelepiped processing tank 70 as shown in FIG. Therefore, the usage-amount of electrolyte solution can also be suppressed.
In the electrolytic treatment apparatus 1 of the present invention, the electrolytic solution L smoothly flows in the treatment tank main body 11, so that it is not necessary to provide a member for adjusting the flow such as a perforated plate in the treatment tank 10.

<Other embodiments>
The electrolytic treatment apparatus of the present invention is not limited to the electrolytic treatment apparatus 1 shown in FIGS. For example, in the electrolytic treatment apparatus 1 shown in FIGS. 6 and 7, the electrode plate 20 is disposed so as to sandwich the base material A, and is curved so as to follow the inner surface shape of the bottom portion 11 a of the treatment tank body 11. As shown in FIG. 8, the electrode plate 20 may be disposed only at a position facing the overflow portion 13 through the base material A immersed in the processing tank body 11. At this time, the ratio (contact area: treatment area) of the area (contact area) in contact with the electrolyte solution L of the electrode plate 20 and the area (treatment area) in contact with the electrolyte solution L of the substrate A is It is preferable that the electrode plate 20 is immersed in the electrolytic solution L in the treatment tank body 11 so as to be 1: 1 or less.
The value of current flowing through the base material A and the electrode plate 20 during the electrolytic treatment is proportional to the ratio of the processing area of the base material A and the contact area of the electrode plate 20. As the contact area of the electrode plate 20 is larger than the processing area of the substrate A, current flows more. When a large amount of current flows, Joule heat (current × voltage) generated in the treatment tank 10 increases, and the amount of heat generation increases. Therefore, the cooling capacity of the apparatus for removing heat increases. If the inside of the treatment tank 10 is kept at a uniform temperature, the generated Joule heat is preferably low.
There is no problem even if the contact area of the electrode plate 20 is smaller than the processing area of the substrate A, but even if it is too small, the final current value is determined by the processing area of the substrate A. The effect of suppressing the current value reaches its peak. Therefore, in order to suppress the amount of flowing current, the ratio of the contact area of the electrode plate 20 and the processing area of the base material A is preferably 1: 1 or less.

Further, when the shape is like the electrode plate 20 shown in FIG. 8, it is not necessary to bend like the electrode plate 20 shown in FIGS. 6 and 7, so that the workability is remarkably improved. In addition, since the electrolyte solution L more easily flows at the bottom 11a of the treatment tank body 11, the renewability of the electrolyte solution L is further improved.
In addition, the outer tank 40 was abbreviate | omitted in FIG.

  Moreover, although the electrolytic treatment apparatus 1 shown in FIGS. 6 and 7 includes the support shaft 31 as the rotating means 30 for rotating the base material A, the energizing shaft 33 connected to the energizing member 34 may be used as the rotating means. . In that case, the support shaft 31 is not connected to the rotation driving unit described above, and may be configured to be able to rotate in synchronization with the base material A.

Furthermore, the energization member 34 does not need to be entirely composed of a conductive material as described above, and may be configured to be able to electrically connect the base material A and the energization shaft 33. . Specifically, the configuration may be such that a portion other than the portion that electrically connects the tapered surface 34a of the energization member 34 and the energization shaft 33 is coated with an insulating material. As for the tapered surface 34a, as long as the base material A and the energizing member 34 can be stably electrically connected, a part of the surface may be made of a material other than the conductive material.
In the above-described embodiment, the inner diameter side corners of both ends of the substrate A are chamfered to form the tapered surface a, and the outer diameter side corner of the energizing member 34 is chamfered to form the tapered surface 34a. However, the outer diameter side corners of both ends of the substrate A may be chamfered, and the inner diameter side corners of the energizing member 34 may be chamfered to form a tapered surface.
Further, the tapered surfaces 34a formed on the respective energizing members 34 need not have the same shape, and may have different shapes. Further, the tapered surface 34 a may be configured to be formed on at least one of the energization members 34.

<Application>
The electrolytic treatment apparatus of the present invention can be used as an apparatus for electrolytically treating the surface of a substrate such as chemical conversion treatment such as anodization or coating treatment such as plating. In particular, an anodization treatment for anodizing an aluminum substrate. It is suitable as a device.
Hereinafter, an example of a method for producing a mold by anodizing an aluminum substrate using the electrolytic treatment apparatus of the present invention will be described.

First, as shown in FIGS. 6 and 7, an aluminum base material is installed on the support shaft 31 as the base material A. At this time, as shown in FIG. 2, the base A is supported by the support shaft 31 so that a gap S is formed between the outer peripheral surface A ′ of the base A and the inner surface 11 a ′ of the bottom 11 a of the treatment tank body 11. Install on top. Specifically, the base material A is installed so that the distance D from the central axis P of the base material A to the inner surface 11a ′ of the bottom portion 11a is 1.25 to 2 times the radius (r) of the base material A. It is preferable to do this.
In addition, when the shape of inner surface 11a 'of the bottom part 11a is a semicircle shape, it is preferable to install the base material A so that the center on the diameter of this semicircle and the central axis P of the base material A may overlap.

Thereafter, the energizing shaft 33 is moved simultaneously from both sides by using the drive unit (not shown) that moves back and forth to bring the energizing member 34 into contact with the substrate A. The electrolytic solution L may be supplied to the treatment tank main body 11 after the substrate A is brought into contact with the conductive member 34, or the conductive member 34 is used in a state where the electrolytic solution L is contained in the treatment tank main body 11. You may make it contact the material A. The rotation drive unit (not shown) is driven in a state where the energization member 34 and the substrate A are in contact with each other, and the support shaft 31 is rotated to rotate the substrate A.
A voltage is applied to the base material A serving as the anode and the electrode plate 20 serving as the cathode through the current-carrying shaft 33 and the current-carrying member 34 while rotating the base material A, so that the base material A is anodized.

  When the current-carrying member 34 is brought into contact with the substrate A, the pressing pressure for bringing it into contact is preferably 0.2 MPa or more. Slip occurs on the tapered surface that is contacted during rotation, and there is an influence on stable current supply due to insufficient contact. However, if the pressing pressure is too large, it may cause distortion of the base material A, or the rotation cannot be transmitted and may stop, so that it is necessary to make an appropriate selection depending on the workpiece shape and the specification of the rotation drive source.

While the base material A is anodized, the same amount of electrolytic solution is supplied to the processing tank body 11 while discharging the part of the electrolytic solution L from the processing tank body 11 while rotating the base material A. Specifically, the electrolytic solution L is discharged from the processing tank body 11 to the outer tank 40 in the overflow portion 13 of the processing tank 10, and the discharged electrolytic solution L is caused to flow down from the outer tank 40 to the storage tank 50. After the temperature of the storage tank 50 is adjusted, the electrolytic solution L is returned to the electrolytic solution supply unit 12 provided above one side surface along the longitudinal direction of the processing tank main body 11 to supply the electrolytic solution. It supplies from the part 12 in the processing tank main body 11. FIG.
At this time, since the inner surface 11a ′ of the bottom 11a of the treatment tank body 11 is curved in an arc shape, a substantially uniform flow of the electrolytic solution L is formed, and the electrolytic solution L smoothly flows to the overflow portion 13 without stagnation. And move.
In addition, it is preferable to rotate the base material A in the direction opposite to the direction in which the electrolysis liquid L flows.

  The supply amount of the electrolytic solution L from the electrolytic solution supply unit 12 to the processing tank main body 11 is preferably such that the number of circulations is at least once every three minutes with respect to the volume of the processing tank main body 11. By doing so, the processing tank main body 11 can perform frequent liquid renewal, and can efficiently remove heat and remove generated hydrogen.

  The rotation speed of the substrate A is preferably 3 rpm or more. If the rotation speed of the base material A is 3 rpm or more, unevenness of the concentration and temperature of the electrolyte L around the base material A can be more effectively suppressed. In view of the capability of the driving device, the rotation speed of the substrate A is preferably 10 rpm or less.

The temperature adjustment of the electrolytic solution L is performed in the storage tank 50 as described above. Specifically, the heat exchanger 53a for cooling the electrolytic solution L and the heater 53b for heating the electrolytic solution L are controlled. Thus, the temperature of the electrolytic solution L is adjusted. As a control method, there is a feedback type PID control.
Here, “PID control” uses the amount of deviation between the output value of the controlled object and the target, and combines the three controls of proportional control, integral control, and differential control, so that the output value becomes the target value in a short time. It is a method of adjusting to reach.

The temperature adjustment of the electrolytic solution L before the base material A is put into the treatment tank 10 may be performed by controlling both cooling and heating. However, when the electrolytic treatment starts, the current flows in the treatment tank main body 11. The electrolyte solution L generates heat due to Joule heat or reaction heat generated by electrolytic treatment. In that case, the temperature rise in the processing tank main body 11 or the temperature rise of the storage tank 50 by the electrolytic solution L sent from the processing tank main body 11 is confirmed, PID control is performed in the storage tank 50, and the electrolytic solution L is used. Try to cool and keep at the desired temperature.
However, a time lag occurs until the inside of the processing tank main body 11 generates heat and the electrolyte L adjusted in the storage tank 50 reaches the processing tank main body 11, during which an unnecessary temperature rise occurs in the processing tank main body 11. May occur, the generation rate of the oxide film formed on the surface of the substrate A may change, and uniform electrolytic treatment may not be performed.

  Therefore, in order to avoid an unnecessary temperature rise, it is preferable to cool the electrolyte solution L slightly during the electrolytic solution treatment, and slightly cooler than the temperature at which the inside of the storage tank 50 is desired to be controlled immediately before the electrolytic treatment. . That is, the control is performed by cooling and heating before the base material A is put into the treatment tank 10, and the control is performed only by cooling just before the base material A is put into the treatment tank 10 and the electrolytic treatment is started. Keep electrolyte low. By doing so, it is also possible to instantaneously cool the electrolyte solution that has generated heat when the electrolytic treatment starts.

When the base material A is anodized as described above, an oxide film 62 having pores 61 is formed as shown in FIG. 9B from the state shown in FIG.
The purity of aluminum used as the substrate A is preferably 99% or more, more preferably 99.5% or more, and further preferably 99.8% or more. When the purity of aluminum is low, when anodization is performed, an uneven structure having a size that scatters visible light due to segregation of impurities is formed, or the regularity of the pores 61 formed by anodization is reduced. Examples of the electrolytic solution include oxalic acid and sulfuric acid.

When using oxalic acid as electrolyte:
The concentration of oxalic acid is preferably 0.7 M or less. When the concentration of oxalic acid exceeds 0.7M, the current value becomes too high, and the surface of the oxide film may become rough.
In order to obtain anodized alumina having fine pores with high regularity at a predetermined cycle, it is necessary to apply a conversion voltage suitable for the predetermined cycle. For example, in the case of anodized alumina having a period of 100 nm, the formation voltage is preferably 30 to 60V. When the formation voltage suitable for the predetermined cycle is not applied, the regularity tends to be lowered.
The temperature of the electrolytic solution is preferably 60 ° C. or lower, and more preferably 45 ° C. or lower. When the temperature of the electrolytic solution exceeds 60 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken, or the surface may melt and the regularity of the pores may be disturbed.

When using sulfuric acid as the electrolyte:
The concentration of sulfuric acid is preferably 0.7M or less. If the concentration of sulfuric acid exceeds 0.7M, the current value may become too high to maintain a constant voltage.
In order to obtain anodized alumina having fine pores with high regularity at a predetermined cycle, it is necessary to apply a conversion voltage suitable for the predetermined cycle. For example, in the case of anodized alumina having a period of 63 nm, the formation voltage is preferably 25 to 30V. When the formation voltage suitable for the predetermined cycle is not applied, the regularity tends to be lowered.
The temperature of the electrolytic solution is preferably 30 ° C. or lower, and more preferably 20 ° C. or lower. When the temperature of the electrolytic solution exceeds 30 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken or the surface may melt and the regularity of the pores may be disturbed.

  And after forming the oxide film 62 which has the pore 61 as shown in FIG.9 (b), the anodic oxidation alumina which has a several pore is carried out by anodizing using the electrolytic treatment apparatus 1 of this invention. A roll-shaped mold is manufactured by repeating the step of forming (anodizing treatment) and the step of expanding the diameter of the pores (pore diameter expanding treatment).

When the anodizing process and the pore diameter expanding process are repeated, first, the oxide film 62 is temporarily removed as shown in FIG. Here, the regularity of the pores can be improved by making this the pore generation point 63 of anodic oxidation.
Examples of the method for removing the oxide film include a method in which aluminum is not dissolved but is dissolved in a solution that selectively dissolves the oxide film and removed. Examples of such a solution include a chromic acid / phosphoric acid mixed solution.

Then, when the base material A from which the oxide film has been removed is anodized again, an oxide film 62 having columnar pores 61 is formed as shown in FIG.
Anodization is performed using the above-described electrolytic treatment apparatus 1. The conditions may be the same as those when the oxide film 62 shown in FIG. 9B is formed. Deeper pores can be obtained as the anodic oxidation time is lengthened.

Then, as shown in FIG. 9E, a process for enlarging the diameter of the pore 61 is performed. The pore diameter expansion treatment is a treatment for expanding the diameter of the pores obtained by anodic oxidation by immersing in a solution dissolving the oxide film. Examples of such a solution include a phosphoric acid aqueous solution of about 5% by mass.
The longer the pore diameter expansion processing time, the larger the pore diameter.

Then, when anodized again, as shown in FIG. 9 (f), cylindrical pores 61 having a small diameter that extend downward from the bottom of the cylindrical pores 61 are further formed.
Anodization is performed using the above-described electrolytic treatment apparatus 1. The conditions may be the same conditions as described above. Deeper pores can be obtained as the anodic oxidation time is lengthened.

Then, when the pore diameter enlargement process and the anodizing process as described above are repeated, the anodized alumina having pores 61 having a shape in which the diameter continuously decreases in the depth direction from the opening (a porous aluminum material). A roll-shaped mold 60 as shown in FIG. 9G on which an oxide film (alumite) is formed is obtained. It is preferable that the last end is a pore diameter expansion process.
The total number of repetitions is preferably 3 times or more, and more preferably 5 times or more. When the number of repetitions is 2 or less, the diameter of the pores decreases discontinuously, and thus the effect of reducing the reflectance of the optical film produced by transferring such pores is insufficient.

  Examples of the shape of the pore 61 include a substantially conical shape and a pyramid shape. The average period between the pores 61 is not more than the wavelength of visible light, that is, not more than 400 nm. The average period between the pores 61 is preferably 25 nm or more.

  The aspect ratio (depth of the pore / width of the opening of the pore) of the pore 61 is preferably 1.5 or more, and more preferably 2.0 or more.

  In the electrolytic processing apparatus 1 according to the present embodiment described above, when the roll-shaped aluminum base material is anodized in the electrolytic solution L of the processing tank body 11 as the base material A, the electrolytic solution L is used as the processing tank body 11. Is supplied from above one side and discharged from the upper part of the other side. At this time, since the inner surface of the bottom of the treatment tank main body 11 is curved in an arc shape, the electrolytic solution L can smoothly move to the overflow portion without stagnation. Accordingly, since temperature fluctuations on the electrolyte solution and the substrate surface are suppressed, anodization is performed almost uniformly over the entire outer peripheral surface of the substrate A, and as a result, a roll shape in which variations in the depth of the pores are suppressed. Can be manufactured.

In particular, if the substrate A is rotated with the central axis of the substrate A as the rotation axis, the concentration of the electrolyte solution and temperature spots around the substrate can be suppressed, so that the substrate A can be anodized more uniformly. It is possible to manufacture a roll-shaped mold in which the variation in the depth of the pores is further suppressed.
Furthermore, if the base material A is installed in the processing tank body 11 such that a gap of a specific size is formed between the outer peripheral surface of the base material A and the inner surface of the bottom of the processing tank body, the base material A and The electrolyte L located between the processing tank main bodies 11 can fully fulfill the role of a buffer material. As a result, even if the treatment tank main body 11 is heated by the heat generated during the anodic oxidation, the substrate A can be prevented from being directly warmed by the treatment tank main body 11. Accordingly, temperature variations on the outer peripheral surface of the base material can be more effectively prevented, and a roll-shaped mold in which variation in depth is further suppressed can be manufactured.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.

[Example 1]
A hollow cylindrical aluminum substrate (purity: 99.99%, length: 1000 mm, outer diameter: 200 mm, inner diameter: 155 mm) was anodized using the electrolytic treatment apparatus 1 shown in FIG.
The electrolytic treatment apparatus 1 is provided with the treatment tank 10 shown in FIG. 2, and the distance D from the central axis P to the inner surface 11a ′ of the bottom portion 11a was 400 mm.
Further, the electrolytic solution L whose temperature was adjusted to 16 ° C. at a flow rate at which the electrolytic solution L was circulated once every 3 minutes was supplied to the processing tank body 11 of the processing tank 10.

10 and 11 show the electrolyte temperature when anodizing is performed.
The graph of FIG. 10 shows the relationship between the time of electrolytic treatment (treatment time) and the rising temperature when the electrolyte solution temperature at a location 50 mm away from the treatment vessel wall surface is measured at several points throughout the treatment vessel.
On the other hand, the graph of FIG. 11 shows the maximum value of the temperature difference (maximum temperature difference) and the time of electrolytic treatment (treatment) when the electrolyte solution temperature near the substrate surface is measured at several points in the longitudinal direction of the substrate. Time).

[Comparative Example 1]
A hollow cylindrical aluminum base material was anodized in the same manner as in Example 1 except that the rectangular parallelepiped processing tank 70 shown in FIG. 12 was used instead of the processing tank 10 shown in FIG. 10 and 11 show the electrolyte temperature when anodizing is performed.

As is clear from FIG. 10, the temperature of the electrolytic solution in the main body of the treatment tank rises due to the influence of heat generated by energization, the heat of the oxidation reaction, etc. by performing the anodizing treatment. Compared with the case of Example 1, the temperature rise was small. This is because, as shown in FIG. 12, the bottom of the processing tank 70 is not curved, and in the rectangular parallelepiped processing tank, the circulation efficiency is poor and an electrolytic solution retention portion is likely to be generated, and the heat generated when the heat is generated becomes in the retention portion. It is considered that the temperature of the electrolytic solution is higher than that of the accumulated portion other than the accumulated portion.
However, in the treatment tank and the electrolytic treatment apparatus of the present invention, the inner surface of the bottom of the treatment tank main body is curved in an arc shape so as to be along the peripheral surface of the base material, so that a retention portion of the electrolytic solution is hardly generated. , Temperature spots are less likely to occur.

Further, as apparent from FIG. 11, in the case of Example 1, the maximum temperature difference of the electrolyte solution in the vicinity of the substrate surface was smaller than in the case of Comparative Example 1. The larger the temperature difference of the electrolyte solution in the vicinity of the substrate surface, the greater the temperature variation on the substrate surface. Therefore, when the anodizing treatment is performed, the variation in the pore depth is affected. In the case of the comparative example 1, since the maximum temperature difference of the electrolyte solution in the vicinity of the substrate surface is large, the temperature unevenness on the substrate surface is also large. This is considered to be due to the fact that the cuboid treatment tank has poor circulation efficiency and is likely to generate a retention portion of the electrolyte, and as a result, the electrolyte temperature on the surface of the base material in the vicinity of the retention portion increases.
However, in the treatment tank and the electrolytic treatment apparatus of the present invention, the inner surface of the bottom of the treatment tank main body is curved in an arc shape so as to be along the peripheral surface of the base material, so that a retention portion of the electrolytic solution is hardly generated. It can suppress that the electrolyte solution temperature of a base-material surface becomes high.

Further, the volume of the treatment tank used in Example 1 was 130 L, whereas the volume of the treatment tank used in Comparative Example 1 was 250 L.
Thus, with the treatment tank of the present invention, it was confirmed that not only the retention of the electrolyte solution can be prevented, but also the amount of the electrolyte solution used can be suppressed.

DESCRIPTION OF SYMBOLS 1 Electrolytic processing apparatus 10 Processing tank 11 Processing tank main body 11a Bottom part 11a 'Inner surface 11b, 11c Side surface 12 Electrolyte supply part 13 Overflow part 20 Electrode plate 30 Rotating means 53 Temperature adjusting means A Base material A' Peripheral surface (outer peripheral surface)
L electrolyte

Claims (8)

In a treatment tank for electrolytic treatment of a cylindrical substrate in an electrolytic solution,
A long processing tank main body in which the electrolytic solution is accommodated and the base material is immersed, an electrolytic solution supply part that supplies the electrolytic solution to the processing tank main body, and an overflow part that discharges the electrolytic solution from the processing tank main body,
The inner surface of the bottom of the treatment tank body is curved in an arc shape,
The electrolyte supply unit is provided above one side surface of the processing tank main body so as to be along the longitudinal direction of the processing tank main body,
The said overflow part is provided in the other side upper part of the processing tank main body so that the longitudinal direction of a processing tank main body may be followed. In an electrolytic processing apparatus for electrolytically processing a cylindrical base material in an electrolytic solution,
A treatment tank provided with a long processing tank main body in which the electrolytic solution is accommodated and the substrate is immersed, an electrolyte supply part for supplying the electrolytic solution to the processing tank main body, and an overflow part for discharging the electrolytic solution from the processing tank main body And an electrode plate immersed in the treatment tank body,
The inner surface of the bottom of the treatment tank body is curved in an arc shape,
The electrolyte supply unit is provided above one side surface of the processing tank main body so as to be along the longitudinal direction of the processing tank main body,
The said overflow part is provided in the other side upper part of the processing tank main body so that the longitudinal direction of a processing tank main body may be followed, The electrolytic processing apparatus characterized by the above-mentioned.   The said electrode plate is arrange | positioned so that the base material immersed in the said processing tank main body may be pinched | interposed, and it curves so that the inner surface shape of the bottom part of the said processing tank main body may be followed. Electrolytic treatment equipment.   The electrolytic processing apparatus according to claim 2, wherein the electrode plate is disposed only at a position facing the overflow portion through a base material immersed in the processing tank main body.   5. The electrolytic processing apparatus according to claim 4, wherein a ratio of an area of the electrode plate in contact with the electrolytic solution to an area of the base material in contact with the electrolytic solution is 1: 1 or less. .   6. The electrolytic processing apparatus according to claim 2, further comprising a rotating unit that rotates the base material about the central axis of the base material.   The electrolytic processing apparatus according to claim 6, wherein the rotating unit rotates the base material in a direction opposite to a direction in which the electrolytic solution supplied from the electrolytic solution supply unit flows to the overflow unit.   8. The method according to claim 2, further comprising temperature adjusting means for adjusting the temperature of the electrolytic solution by heating or cooling the electrolytic solution, and cooling the electrolytic solution immediately before and during the electrolytic treatment. The electrolytic treatment apparatus according to claim 1.

Images