JPH09272993A - Drum for metal foil electrodeposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a good quality metal foil having small nonuniformity in thickness and no heat-affected zone such as hot spot by forming a tin, lead or tin-lead alloy layer on the outer peripheral surface of an inner drum made of carbon steel or the like, also forming a coating film of a platinum group metal or its oxide on the inner peripheral surface of an outer cylinder made of titanium, and then subjecting the both resulting surfaces to shrinkage fitting to manufacture the subject drum. SOLUTION: In the manufacture of this drum for metal foil electrodeposition, a tin, lead or tin-lead alloy layer 11 is formed on the outer peripheral surface of an inner drum 9 made of carbon steel, stainless steel or a copper alloy, and also, a coating film 12 of a platinum group metal or its oxide is formed on the inner peripheral surface of an outer cylinder 10 made of titanium, and then, both the resulting outer peripheral surface of the inner drum 9 and the resulting inner peripheral surface of the outer cylinder 10 are subjected to shrinkage fitting to obtain the objective drum. The layer 11 has excellent corrosion resistance and protects the undercoat metal, i.e., the metallic material of the inner drum 9 from corrosion. Also, the layer 11 consisting of a soft metal is allowed to enter into recessed parts of the titanium rough surface of the outer cylinder 10 to increase the contact area of the inner drum 9 and outer cylinder 10 with each other. With the coating film 12, the contact electric resistance can be reduced, and also, the titanium metal of the outer cylinder 10 can be prevented from being oxidized at the time of performing the heating for shrinkage fitting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating cathode type metal foil electrodeposition drum used for producing an electrolytic metal foil.

[0002]

2. Description of the Related Art Electrolytic metal foils include copper foil, nickel foil, iron foil, etc., but the most widely used today is copper foil for printed wiring boards used in electronic devices, such as titanium or It is manufactured by an electrolytic copper foil manufacturing apparatus equipped with a rotating cathode type electrodeposition drum having stainless as an electrodeposition surface.
As shown in FIG. 1, this apparatus, which is a typical example of metal foil production, is set with a rotary cathode type electrodeposition drum 2 supporting both ends of a rotary shaft 3 on bearings 4 at the center of a bath 1 which serves as a container for copper plating solution. Approximately one half of the volume is immersed in the plating solution 5, and the current collector ring 7 and the DC power source 8 are supplied while the plating solution is supplied between the anode 6 and the electrode 6 that faces the electrodeposition surface serving as the cathode. Direct current is passed through the surface of the plating bath, and copper is plated on the electrodeposition surface that has penetrated into the solution from one side of the plating bath surface, and the prescribed thickness is reached until it comes out of the plating bath liquid surface on the other side into the air. After becoming the copper foil of
It is continuously manufactured as if it was peeled off from the electrodeposition surface and wound on a bobbin.

FIG. 2 is a partially cutaway front view of the electrodeposition drum. A titanium rolling plate is formed on the machined outer peripheral surface of an inner drum 9 made of carbon steel, stainless steel or copper alloy, which is constructed around the rotary shaft 3. The roll is formed into a ring shape, and the inner cylinder made by butt-welding both ends of the outer cylinder is slightly smaller than the outer diameter of the inner drum.The outer cylinder 10 is fitted by shrink fitting, and the surface of titanium that becomes the electrodeposition surface. Is used after being mechanically finished and polished. Typical dimensions of such an electrodeposited drum for copper foil are a diameter of 2 to 3 m and a width of 1 to 3 m,
The thickness of titanium on the electrodeposited surface is 5 to 8 mm. In the present invention, the surface treated metal foil electrode on both surfaces of the joint between the outer peripheral surface of the carbon steel, stainless steel or copper alloy inner drum 9 and the inner peripheral surface of the titanium outer cylinder 10 at the portion A shown in FIG. Regarding wearing drums.

The joint portion of the electrodeposition drum which is integrally formed by shrink-fitting the titanium outer cylinder of this kind to the inner drum is basically titanium in which one of the contacting surfaces forms a passivation film on the surface. Yes, it is a contact of dissimilar metals with a large difference in physical properties from the other surface, the titanium oxide film with high electrical resistance increases on the titanium surface of the outer cylinder due to high temperature heating during shrink fitting, and the outer cylinder has a titanium rolling plate. Since the roundness is not sufficient because it is made by roll forming into a cylinder shape and butt-welding both ends, the contact surface between the inner surface of the outer cylinder and the outer surface of the inner drum, which has been shrink-fitted, is not fully contacted. A close contact and a gap are created. Since the outer peripheral surface of the inner drum, which is easily oxidized, located in the gap portion is oxidized over time and rusted to increase the contact failure area, the thickness of the electrodeposited metal foil varies. Furthermore, when electric current flows from the inner surface of the titanium cylinder in a wide range where the contact failure is increased to the surface of the inner drum in a discharge manner, the local area of the titanium plate is melted and deteriorated by Joule heat. The copper foil electrodeposited on the copper sheet suffers from the disadvantage of loss of product value due to alteration called hot spot.
Therefore, many proposals have been made to date in order to improve the various drawbacks that occur during such shrink fitting.

In order to improve the gripping force of the outer cylinder to be shrink-fitted and to increase the contact surface pressure, these improvement proposals are provided with alternating peaks and troughs on the outer peripheral surface of the inner drum, and silver plating is applied to the peaks to be the contact surface. Method of providing layers (Japanese Patent Publication No. 58-2450)
No. 7), silver or platinum plating on both contact surfaces of the inner drum and the outer cylinder, gold plating (Japanese Patent Publication No. 61-60149), titanium surface is coated with silver or gold, precious metal such as palladium (Japanese Patent Sho 62-233
No.), a method of integrating an inner drum and a titanium drum externally attached to the inner drum via a low melting point metal (Japanese Patent Publication No. 2-55510).
No.), a method of shrink-fitting an outer cylinder onto an inner drum via a mesh or porous metal sheet (JP-A 3-1
91079), a method of shrink-fitting the outer cylinder by winding a conductive wire with a large coefficient of thermal expansion around the outer peripheral surface of the inner drum (JP-A-4-116190), the outer peripheral surface of the inner drum and the inner peripheral surface of the outer cylinder. There are many proposals such as a method of integrating by interposing a soft intermediate material with excellent conductivity and corrosion resistance between the and (Japanese Patent Laid-Open No. 4-103788), but each has effects, workability, durability, economic efficiency, etc. There are merits and demerits to the above, and it cannot be said that they are necessarily satisfied.

[0006]

For example, focusing on the titanium surface treatment on the outer cylinder side, the above-mentioned Japanese Patent Publication No.
In No. -60149, silver or platinum or gold is plated on copper or nickel undercoat, and in Japanese Patent Publication No. 62-233, noble metal such as silver or gold or palladium is coated. Japanese Examined Patent Publication No. 2-55510 proposes silver plating as an undercoat for soldering the inner drum, but titanium, which is the most suitable thin film forming metal, is different from iron, nickel, copper, etc. Since it belongs to a metal that cannot be soldered or welded to a dissimilar metal, the coating such as silver, platinum, and gold formed on the titanium surface by the general wet plating method or thermal spray coating method is a metal with the underlying titanium. Interbonding is extremely weak and easy to peel off. Undercoating of copper, etc. is effective in increasing the adhesion of the plating film of silver, platinum, etc. to titanium, but the adhesion of the undercoating itself to titanium is not sufficient and the edge of the plating film easily peels off. There is a problem in that the labor and cost of the above-mentioned overlapping plating work increase. Such titanium surface plating or coating film, when the electrodeposition surface penetrates into the high temperature plating bath during operation of the electrodeposition drum, is exposed to the atmosphere and is left to cool, and the outer cylinder expands due to repeated temperature changes, As a result of the repeated contraction, the contact surface with the inner drum moves relative to each other microscopically, resulting in peeling and diminishing its effect. Further, regarding the carbon steel or copper alloy surface treatment on the inner drum side, it is described in the above proposals that the same precious metal plating or coating as the titanium cylinder is applied for the purpose of rust prevention and contact resistance reduction, respectively. There is a tendency to increase costs.

Further, focusing on the proposal of interposing an electrically conductive and thermally expansive intermediate material between the outer peripheral surface of the inner drum and the inner peripheral surface of the outer cylinder, the outer peripheral surface of the inner drum may be in the form of a net, a sheet, a cylinder or a wire. It is extremely difficult to stick or wind and fix the material, and it takes time and labor, and if the outer circumference of the fixed intermediate material is not a perfect circle, it will contact the inner surface of the titanium cylinder during shrink fitting and cause friction. There is a risk that smooth insertion may not be possible. The above-mentioned Japanese Patent Laid-Open No.
In 4-103788, the proposal to integrate the material such as copper and aluminum into the inner surface of the titanium cylinder by explosion bonding etc. solves the above problem, but the melting point of the material is higher than the heating temperature at the time of shrink fitting. In addition, the material is limited to materials that are not deformed by the explosion pressure, and the cost tends to increase due to special processing. The present inventors have found that the plating or coating of noble metal on the surface of these titanium cylinders does not have sufficient adhesion to the base material, and that the construction is laborious and expensive, and the method of interposing an intermediate material, A precious metal coating method and intermediate material forming method that are easy to install, have excellent adhesion, and are economical, with an emphasis on making it difficult to place and fix them on the outer peripheral surface of the inner drum and to make the shrink fitting process extremely difficult. As a result of working on research to develop, the present invention has been completed.

[0008]

Means for Solving the Problems That is, a tin, lead or tin-lead alloy layer is formed on the outer peripheral surface of an inner drum made of carbon steel, stainless steel, copper alloy or the like, and platinum is formed on the inner peripheral surface of an outer cylinder made of titanium. It is a metal foil electrodeposition drum formed by forming a coating film of a group metal or its oxide and shrink-fitting both surfaces.

Here, the coating of the platinum group metal or its oxide on the inner peripheral surface of the titanium outer cylinder is applied with a solution prepared by dissolving a chloride or complex compound of the coating component in an organic solvent and incorporating a reducing substance, and drying. And is formed by firing.

As described above, the solution means of the present invention comprises two means for the inner drum side and the outer cylinder side. The first is an inner drum side means for forming a tin, lead or tin-lead alloy layer on the outer peripheral surface of the inner drum made of a material such as carbon steel. These metals or alloys have excellent corrosion resistance and, in addition to the effect of preventing corrosion of the base metal, are soft in hardness, so if they have a certain thickness, the grip of the outer cylinder can be shrink-fitted like the role of conventional intermediate materials. It is possible to produce an effect of increasing the contact area by digging into the recess of the rough titanium surface that has been rolled and has a large hardness due to the force. The formation of the tin, lead or tin-lead alloy layer is generally performed by plating a part of the surface to be the electrodeposition surface of the inner drum supporting the rotating shaft in the rotating cathode type plating device similar to the electrolytic copper foil manufacturing device shown in FIG. It is performed by immersing in a bath and rotating it while applying a current amount corresponding to a plating amount of a required thickness under each appropriate plating condition. For the anode, a pure tin plate or a pure lead plate is used in the case of tin plating or lead plating, and an alloy plate having the same composition as the intended alloy plating component is used in the case of tin lead alloy. The tin plating is a sulfuric acid acidic bright bath, the lead plating is a sulfamic acid bath, and the tin lead alloy plating is a bright borofluoric acid solder plating bath. To obtain. The thickness of the plating layer is 15 μm or more, which has no pinholes and is necessary to ensure the rustproof effect on the base material of carbon steel or copper alloy, and further penetrates into the concave part of the titanium surface of the outer cylinder to be shrink-fitted and electrically It is preferably 50 μm or more, which is effective for enhancing the contact effect. The plating layer formed in this way is the same as a metal sheet attached to the inner drum in terms of its thickness when viewed as an intermediate material, and there is no mounting problem in the conventional proposal in which the intermediate material is interposed. .

Secondly, an outer layer for forming a platinum group metal or its oxide film on the inner peripheral surface of the outer cylinder made of titanium, which has a large conductivity and reduces the contact electric resistance, and also has an effect of preventing oxidation during shrink fitting and heating. It is a means on the cylinder side. The means of the proposal is platinum, iridium, chlorides or complex compounds of platinum group metals such as palladium, for example, platinum chloride or chloroplatinic acid in the case of platinum, iridium chloride or iridium chloride in the case of iridium, these are used. Is dissolved in an organic solvent such as butyl alcohol or propyl alcohol, and a reducing substance such as lavender oil or turpentine oil is mixed to form a viscous liquid that is concentrated by heating to form a coating liquid, which is applied to the titanium surface by brush or spray. Then, the dried coating film is baked in air at 400 to 600 ° C to thermally decompose the chloride or complex compound of the platinum group metal in the coating film and reduce it to the metal and / or its oxide to form the titanium surface. It is carried out by a method called a thermal decomposition reduction method of causing precipitation. This method uses a platinum group metal or an oxide thereof which has an electrocatalytic effect on the surface of a titanium base material called a metal electrode developed as an anode for chlorine generation in the salt electrolysis industry. Application of group metal coating method to obtain platinum group metal and / or its oxide coating bonded to titanium surface texture, which cannot be obtained by general wet electrolytic plating method, electroless plating method or thermal spray coating method. . In particular, since iridium is firmly bonded to the oxide film structure on the surface of titanium, adding a small amount to platinum forms a platinum film with strong adhesion. The feature of this method is that it is economical because the construction tool required is a brush for applying at least the coating solution and a gas burner for baking as long as the coating solution is prepared, and the construction is easy.

The metal foil electrodeposition drum of the present invention comprises first, second
The use of an inner drum and an outer drum surface-treated by the method described above is characterized in that the electrical contact resistance of both contact surfaces at the time of shrink fitting becomes small. In the combination of tin plating and platinum coating, both contact surfaces are silver. under a slight 2mV high current densities comparable to 150A / dm ² in contact resistance when plated
The following good contacts are obtained.

As a first means, a tin, lead or tin-lead alloy layer having a thickness of 50 μm or more provided on the outer peripheral surface of the inner drum is pressed against the titanium surface of the outer cylinder which is shrink-fitted on the surface to form a rough titanium surface. As a result of biting into the recess and increasing the contact area, the contact resistance is reduced. Further, the tin, lead or tin-lead alloy layer has a function of permanently preventing corrosion of the carbon steel or copper alloy surface of the inner drum which is easily corroded, and a preferable conductive function of the outer cylinder and the inner drum as a good conductor of electricity.

The coating of platinum group metal or its oxide formed on the titanium surface on the inner circumference of the outer cylinder, which is the second means, is a titanium surface which is formed at the time of heating to increase the inner diameter of the outer cylinder which is applied during shrink fitting. It has the function of suppressing the formation of a titanium oxide film with high electrical resistance due to oxidation, and the function of improving the contact with the tin, lead or tin-lead alloy layer on the outer peripheral surface of the inner drum due to the conductive effect of the platinum group metal. To do.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described by the following examples. Example 1 An electrodeposition drum having a diameter of 500 mm and a width of 300 mm equipped with a rotating shaft having the structure shown in FIG. 2 was manufactured as follows. First, the outer periphery 9 of the inner drum was formed of carbon steel (SS400) having a thickness of 12 mm, and the surface thereof was turned and finished. The surface roughness measured by a surface roughness meter was Ra = 8.6 μm. Next, after the surface is alkali degreased, acid-etched and washed with water, a tin plating tank basically similar to the electrolytic copper foil manufacturing apparatus of FIG. 1 is masked except for the electrodeposited surface and about 1/6 of the surface is plated. A plating layer having an average thickness of 85 μm and having a metallic tin luster was formed under the following conditions while being set so as to be immersed in the liquid and rotating at 0.5 to 1 rpm for a pure tin plate as an anode.・ Plating bath composition: SnSO ₄ 40 g / liter H ₂ SO ₄ 100 〃 Surfactant 20 〃 Brightener 10 〃 ・ Plating conditions: Bath temperature 15-25 ° C Cathode current density 3A / dm ² Gap distance 100 mm

Thickness of 5.5 mm, surface roughness (Ra) = 1.6 μm
A ring of pure titanium rolled from the above was ring-formed and welded to produce an outer cylinder with an inner diameter of 499.8 mm and a width of 320 mm, which is 0.2 mm smaller than the outer diameter of the inner drum. Then, the inner peripheral surface was thoroughly cleaned, and platinum iridium coating was performed by the following. Chloroplatinic acid (hexahydrate) 5 g, iridium chloride 0.
Add 5 g to butyl alcohol (60 ml) with concentrated hydrochloric acid (0.2 ml) and dissolve under heating. Mix this with lavender oil (20 ml).
60 ml of black viscous coating liquid was prepared. Subsequently, the coating liquid was uniformly applied to the titanium surface by a brush several times, and the titanium liquid was naturally dried to form a brown coating film. While rotating the outer cylinder, baking was performed at a surface temperature of 400 ° C. with propane gas flame to burn off the coating film, and at the same time, a platinum iridium coating film was formed on the titanium surface. The bondability of this coating was tested by a peel test using an adhesive tape, and it was confirmed that it did not peel.

This outer cylinder was heated to 350 ° C., the inner drum having a tin layer formed thereon was shrink-fitted, the rear side plate was attached, and the electrodeposition surface was polished to complete the electrodeposition drum of the present invention. In order to confirm the effect of the present invention, a comparative electrodeposition drum having only shrink fitting was manufactured with exactly the same specifications except for the surface treatment of tin plating and platinum coating. Basically, a copper foil manufacturing test apparatus having the same structure as in FIG. Set, copper plating solution concentration 250
g / liter (CuSO ₄ .5H ₂ O), replenishment copper ion decomposition rate 5%, DSE anode, distance between electrodes 6 mm, temperature 65 ° C, foil thickness
A foil making test was performed under operating conditions of 35 microns and cathode current density of 60-100 A / dm ² . 60A / dm ^{2 for} the first month
It was operated at 80 A / dm ² for 1 month and 100 A / dm ² for 1 month for a total of 3 months. Throughout the entire period, the copper foil of the present invention stain, burns, no abnormalities such as hot spots were observed, but the copper foil of the comparative drum was burned at the end of the width of the foil at 80 A / dm ² or more, With 100 A / dm ² , local stain-like discoloration occurred and normal production of copper foil was not possible. Also, the copper foil of both drums at 60 A / dm ^{2 was} taken for one round, the 250 mm width excluding 25 mm at both ends of the width was divided into 5 equal parts, and cut into 50 mm square small pieces that were divided into about 31 equal parts in the length direction. And measure the total number, and the variation rate from the average value a, maximum value b, minimum value c
(%) = (B−c) / a × 100 was calculated. As a result, the comparison drum was 6.9%, while that of the drum of the present invention was
It was a low value of 1.8%. From this, it was confirmed that the electrodeposition drum subjected to the surface treatment of the present invention is effective in improving the contact between the inner drum and the outer drum and reducing the variation in the thickness of the electrodeposition metal foil.

Example 2 In order to compare the effect of the tin plating and the platinum coating on the contact resistance in Example 1 and the contact resistance of the shrink-fitted joint combining the two with the contact resistance in the case of no treatment and silver plating, The following test pieces were prepared using the same materials as in Example 1, and each test piece was subjected to the following surface treatment. Test piece A Material: Titanium Size: 5t × 50 × 50mm Surface roughness (Ra): 1.6μm Test piece B Material: Carbon steel Size: 25t × 50 × 50mm Surface roughness (Ra): 6.3μm Titanium surface treatment A ₁ : Platinum iridium coating (0.5 μm) ... Same conditions as in Example 1 A ₂ : No treatment A ₃ : Undercoat (copper 15 μm, nickel 5 μm) Silver plating (2 μm) Carbon steel surface treatment B ₁ : Tin Plating (85 μm) ... Same conditions as in Example 1 B ₂ : No treatment B ₃ : Undercoat (copper 15 μm) Silver plating (2 μm)

Next, a terminal copper plate is placed on the back surface of the A ₁ and B ₁ test pieces so that the surface-treated surfaces face each other. The terminals are sandwiched between presses and pressed at a pressure of 5 kg / cm ² which is approximately equal to the surface pressure corresponding to shrinkage fitting, and the terminals are pressed. Through contact with copper plate Current density = 100A / dm ²
A considerable current of 37.5 A was applied and the voltage drop between the faces was measured. Next, in order to verify the A _1, B ₁ each effect, with A ₂ and B ₂ without surface treatment measurement of the combination of Table 1 were made. Next, as a conventional example, the contact surfaces of A ₃ and B ₃ , which are the contacts between silver platings proposed in Japanese Patent Publication No. 61-60149, were measured. Table 1 shows these measured values.

[0020]

[Table 1]

As is clear from Table 1, the combined effect of platinum iridium and tin on the contact resistance is significantly greater than the effect of the platinum iridium coating and tin plating alone, and the ideal contact between silver platings is almost the same. It turns out that they are comparable.

Example 3 A tin-lead alloy plating layer having an average thickness of 100 μm was formed on the surface of an inner drum manufactured according to the same specifications as in Example 1 under the following conditions.・ Plating bath composition: stannous (Sn ² +) 30 g / liter lead (Pb ² +) 20 〃 free borofluoric acid 100 〃 dispersant 30 〃 brightener 50 〃 ・ plating conditions: bath temperature 15 to 20 ° C cathode current Density 3A / dm ² Anode (Sn: Pb) 60:40

An outer cylinder having the same specifications as in Example 1 was manufactured, and a platinum film was formed on the inner surface of the outer cylinder by the following procedure. Dissolve 8 g of chloroplatinic acid in 60 ml of isopropyl alcohol, mix with 20 ml of turpentine oil, and concentrate by heating to about 60
ml coating solution was prepared. Then, it was uniformly applied to the titanium surface with a brush to form a brown coating film. continue,
Baking was carried out at a surface temperature of 450 ° C with city gas to form a platinum film. The bondability of this coating to the titanium surface was examined and it was confirmed that peeling was difficult. Further, the titanium cylinder was heated to a surface temperature of 370 ° C. and shrink-fitted on the tin-lead alloy-plated inner drum.

Finally, the finished test electrodeposition drum was finished, and the copper foil thickness was 35 μm and 18 μm under the high current density conditions of cathode current density of 100 A / dm ² and temperature of 65 ° C. according to Example 1.
As a result of sequentially conducting the foil-making test for 2 months each, a high-quality copper foil without any alteration such as hot spots was produced.
Further, the contact resistance between the platinum coating and the tin-lead alloy plating was measured using a test piece in the same manner as in Example 2, and 100 A / dm ²
A low value of 1.4 mV was obtained. In addition, Example 1
And, the cost required for the platinum iridium coating and the platinum coating in Example 3 and the cost of the wet method silver plating including the undercoating currently adopted in a part of the copper foil industry were compared, and the result was about 3 /. It was 5, and we admitted that this method is extremely economical.

Example 4 A lead plating layer having an average thickness of 120 μm was formed on the surface of an inner drum manufactured according to the same specifications as in Example 1 under the following conditions.・ Plating bath composition: Lead borofluoride (Pb ² +) 30 g / liter Free borofluoric acid 160 〃Peptone 2 〃 ・ Plating conditions: Bath temperature 30 ° C Cathode current density 8A / dm ² Anode (lead purity) 99.9%

An outer cylinder was manufactured with the same specifications as in Example 1, and a palladium coating was formed on the inner surface of the outer cylinder by the following procedure. Palladium chloride 5g, ethyl alcohol 60ml
80 ml of a solution of turpentine oil and lavender oil mixed in a ratio of 3: 7 was added and mixed to prepare a palladium coating solution, and a titanium surface was brushed and dried, and then the work was repeated several times. Palladium was deposited by heating and burning at 400 ° C. with a flame of propane gas. After the bondability of this coating was checked and it was confirmed that it did not peel off, it was shrink-fitted at 350 to an inner drum coated with lead.

Then, the test electrodeposition drum which was finished and finished was subjected to the production test of 35 μm and 18 μm copper foil in accordance with Example 1 for 2 months and 4 months, respectively. As a result, there was no alteration such as hot spots. Good quality copper foil was produced. Further, the contact resistance between the palladium-coated surface and the lead-coated surface was measured using a test piece as in Example 2, and the contact resistance at 100 A / dm ^{2 was} 1.
A low value of 5 mV was obtained.

[0028]

As is apparent from the above embodiments, the electrodeposition drum manufactured by subjecting the contact surface of the inner drum and the outer cylinder to the surface treatment of the present invention has a small thickness unevenness and is free from alteration such as hot spots. In addition to being able to produce high quality copper foil, the conventional wet plating method for precious metal plating of silver, platinum, etc. on the titanium surface of the outer cylinder, and shrink fitting of an intermediate material such as a metal film on the inner drum surface The method is excellent in easiness, adhesion, and economic efficiency with respect to the method, and it becomes possible to reduce the manufacturing cost of the electrolytic metal foil comprehensively.

[Brief description of drawings]

FIG. 1 is a schematic front view of an apparatus for producing an electrolytic copper foil.

FIG. 2 is a partially cutaway front view showing an electrodeposition drum structure in which an outer cylinder is shrink-fitted and joined to an inner drum and a joining boundary surface.

FIG. 3 is an enlarged cross-sectional view corresponding to part A of FIG. 2 showing a shrink fitting joint interface between an inner drum and an outer cylinder that have been subjected to the surface treatment of the present invention.

[Explanation of symbols]

 1 Bath 2 Rotating cathode type electrodeposition drum 5 Plating layer 6 Anode 9 Inner drum (carbon steel) 10 Outer cylinder (titanium) 11 Tin, lead or tin-lead alloy plating layer 12 Platinum group metal or its oxide coating

Claims (2)

[Claims] 1. A tin, lead or tin-lead alloy layer is formed on the outer peripheral surface of an inner drum made of carbon steel, stainless steel, copper alloy or the like, and a platinum group metal or its oxide is formed on the inner peripheral surface of an outer cylinder made of titanium. A metal foil electrodeposited drum obtained by forming a coating film on and then shrink-fitting both surfaces. 2. A coating of a platinum group metal or its oxide on the inner peripheral surface of a titanium outer cylinder is applied with a solution prepared by dissolving a chloride or complex compound of the coating component in an organic solvent and incorporating a reducing substance, and drying the solution. The metal foil electrodeposition drum according to claim 1, which is formed by firing.