JP2015137380A - Method and apparatus for manufacturing aluminum film - Google Patents

Abstract

A method of manufacturing an aluminum film in which moisture and oxygen do not enter a plating chamber is provided. A step of bringing a long porous resin substrate W subjected to a conductive treatment into the plating chamber through a seal chamber 4 provided on the inlet side of the plating chamber 1 containing a molten salt electrolyte, and the plating A step of electrodepositing an aluminum film on the surface of the porous resin substrate in the chamber, and a porous resin substrate electrodeposited with the aluminum film is carried out of the plating chamber through a seal chamber 5 provided on the outlet side of the plating chamber. A seal roll 6 is provided on each of the inlet side and the outlet side of the seal chamber, and the space between the seal rolls 6 in the seal chamber is porous by at least one diffusion prevention plate 7 A method for producing an aluminum film, wherein the aluminum substrate is partitioned into a plurality of chambers in the direction of transport of the resin base material, and one end of the diffusion prevention plate is disposed at a distance from the porous resin base material. [Selection] Figure 1

Description

  The present invention relates to an aluminum film manufacturing method and apparatus for electroplating aluminum on the surface of a long porous resin substrate to form an aluminum film on the substrate.

Aluminum is passivated by forming a dense oxide film on its surface and exhibits excellent corrosion resistance. For this reason, the surface of a steel strip or the like is subjected to aluminum plating to improve the corrosion resistance.
For example, in order to perform aluminum plating on the surface of a steel strip, first, the steel strip is continuously fed into a plating chamber through a conductor roll and travels in an anode immersed in a plating solution in the plating chamber. At this time, since the steel strip itself is electrically connected so as to act as a cathode, electrolysis occurs between the anode and the steel strip that is the cathode, and aluminum is electrodeposited on the surface of the steel strip. A plating is formed. The direction of the steel strip traveling in the plating solution is changed by the turn roll, and this time it travels upward. In this case as well, plating is performed with the anode. The steel strip on which the aluminum plating is formed leaves the plating chamber and then is taken out of the system through a conductor roll (see Patent Document 1).

  In addition, a porous body made of aluminum having a three-dimensional network structure is promising as improving the capacity of the positive electrode of a lithium ion battery. At present, a material obtained by applying an active material such as lithium cobaltate to the surface of an aluminum foil by taking advantage of the excellent characteristics of aluminum such as conductivity, corrosion resistance and light weight is used as a positive electrode of a lithium ion battery. By forming the positive electrode with a porous body made of aluminum, the surface area can be increased and the active material can be filled inside the aluminum. Thereby, even if the electrode is thickened, the utilization factor of the active material is not reduced, the utilization factor of the active material per unit area is improved, and the capacity of the positive electrode can be improved.

The present applicant has proposed a method of electroplating aluminum on a resin molded body having a three-dimensional network structure as a method for producing the aluminum porous body as described above (see Patent Document 2). Since the conventional aluminum molten salt bath needs to have a high temperature, there has been a problem that when the aluminum is electroplated on the surface of the resin molded body, the resin cannot withstand the high temperature and dissolves. However, according to the method described in Patent Document 2, an organic chloride salt such as 1-ethyl-3-methylimidazolium chloride (EMIC) or 1-butylpyridinium chloride (BPC) and aluminum chloride (AlCl ₃ ) are used. By mixing, a liquid aluminum bath is formed at room temperature, and electroplating of aluminum onto the resin molded body becomes possible. In particular, the EMIC-AlCl ₃ system has good liquid properties and is useful as an aluminum plating solution.

  By the way, in a continuous electroplating apparatus using a molten salt as a plating solution, when the molten salt as a plating solution comes into contact with the atmosphere, it reacts with moisture in the air and absorbs moisture to produce a reaction product, which is required as a plating solution. Function is impaired. In particular, when a chloride-based molten salt is used for aluminum-based plating, the molten salt reacts with moisture in the air to produce hydrogen chloride, which deteriorates the work environment and corrodes each component of the plating equipment. There is a problem of doing. Moreover, since metal aluminum has the characteristic which is very easy to oxidize, the aluminum film formed in the base-material surface also reacts with the trace amount dissolved oxygen contained in a plating solution, and will become aluminum oxide. When such a reaction occurs simultaneously with the growth of the plating film, the crystal grains of aluminum change, causing problems that the mechanical strength of the plating film is lowered and the electrical conductivity is deteriorated.

Therefore, in a continuous electroplating apparatus using a molten salt as a plating solution, a closed system in which the plating solution is completely shut off from the outside air is used (see Patent Document 3).
In order to form a closed system, as shown in FIG. 8, N ₂ gas has two pairs of seal rolls at the inlet and outlet of the continuous sheet material (hereinafter also referred to as “work”) to the plating chamber 1. Are provided, and the plating chamber 1 is sealed. In addition, by making the N ₂ gas pressure in the plating chamber a positive pressure, moisture and oxygen are prevented from entering the plating chamber from outside air.

Japanese Patent Laid-Open No. 05-222599 JP 2012-007233 A JP 2000-87287 A

When the present inventors electroplated aluminum on a resin molded body having a three-dimensional network structure with a plating apparatus having a sealing chamber as described above, the plating apparatus still has a slight amount even though it has a sealing chamber. It has been found that there is a problem that moisture and oxygen enter the electrolytic chamber.
An object of this invention is to provide the manufacturing method and manufacturing apparatus of an aluminum film which a water | moisture content and oxygen do not penetrate | invade in a plating chamber in view of the said problem.

  As a result of intensive investigations to solve the above-mentioned problems, the present inventors have obtained the knowledge that the penetration of moisture into the plating chamber can be prevented by providing a diffusion prevention plate in the seal chamber, thereby completing the present invention. did.

In order to solve the above problems, the present invention employs the following configuration.
That is, the method for producing an aluminum film according to the present invention includes:
In a molten salt electrolyte, a method for producing an aluminum film in which aluminum is electrodeposited on the surface of a long porous resin base material provided with conductivity,
Carrying the substrate into the plating chamber through a seal chamber provided on the inlet side of the plating chamber;
Electrodepositing an aluminum film on the surface of the porous resin substrate in the plating chamber;
Carrying out the porous resin base material electrodeposited with the aluminum film from the plating chamber through a seal chamber provided on the outlet side of the plating chamber,
Seal rolls are respectively provided on the inlet side and the outlet side of the seal chamber,
The space between the seal rolls in the seal chamber is partitioned into a plurality of chambers in the transport direction of the porous resin substrate by at least one diffusion prevention plate,
One end of the diffusion preventing plate is disposed at a distance from the porous resin substrate,
Production method of aluminum film,
It is.
Moreover, the apparatus for producing an aluminum film according to the present invention comprises:
An apparatus for producing an aluminum film in which aluminum is electrodeposited on the surface of a long porous resin base material provided with conductivity in a molten salt electrolyte,
A plating chamber;
A seal chamber provided on each of the inlet side and the outlet side of the substrate of the plating chamber;
Have
The seal chambers are provided on each of an inlet side and an outlet side of the base material;
A space sandwiched between the seal rolls in the seal chamber and at least one diffusion prevention plate that divides the space into a plurality of chambers in the transport direction of the porous resin substrate,
Aluminum film manufacturing equipment,
It is.

  According to the present invention, in an aluminum film forming apparatus that forms an aluminum film on a substrate using a molten salt electrolyte, it is possible to reliably prevent moisture and oxygen from entering the plating chamber.

It is a figure which shows an example of the aluminum film manufacturing apparatus of embodiment of this invention. It is a figure which shows an example of the structure of the seal chamber used in embodiment of this invention. It is a figure which shows an example of the other structure of the seal chamber used in embodiment of this invention. It is a flowchart which shows the manufacturing process of an aluminum porous body. It is a cross-sectional schematic diagram explaining the manufacturing process of an aluminum porous body. It is a figure explaining an example of the continuous electroconductivity process of the resin porous body surface by an electroconductive coating material. It is a figure which shows the metal porous body which has a three-dimensional network structure which has a continuous pore. It is a figure which shows the manufacturing apparatus of the conventional aluminum film.

First, the contents of the embodiment of the present invention will be listed and described.
(1) An aluminum film manufacturing method according to an embodiment of the present invention includes:
In a molten salt electrolyte, a method for producing an aluminum film in which aluminum is electrodeposited on the surface of a long porous resin base material provided with conductivity,
Carrying the substrate into the plating chamber through a seal chamber provided on the inlet side of the plating chamber;
Electrodepositing an aluminum film on the surface of the porous resin substrate in the plating chamber;
Carrying out the porous resin base material electrodeposited with the aluminum film from the plating chamber through a seal chamber provided on the outlet side of the plating chamber,
Seal rolls are respectively provided on the inlet side and the outlet side of the seal chamber,
The space between the seal rolls in the seal chamber is partitioned into a plurality of chambers in the transport direction of the porous resin substrate by at least one diffusion prevention plate,
One end of the diffusion preventing plate is disposed at a distance from the porous resin substrate,
Production method of aluminum film,
It is.
According to the present embodiment, it is possible to reliably prevent the moisture and oxygen in the outside air from entering the plating chamber by the diffusion prevention plate provided in the seal chamber, so it is possible to obtain a high-quality aluminum plating film, In addition, generation of harmful substances such as hydrogen chloride can be prevented.
(2) The aluminum film manufacturing method according to the embodiment of the present invention is such that the diffusion prevention plate is a plate having an L-shaped cross section, a plate having a T-shaped cross section, or a flat plate. Manufacturing method.
By using the diffusion prevention plate having the shape defined in the present embodiment, an excellent diffusion prevention effect is exhibited.
(3) The method for producing an aluminum film according to an embodiment of the present invention is described in (1) or (2) above, wherein the seal chamber has a length in the transport direction of the porous resin substrate of 300 mm or more. It is a manufacturing method of an aluminum film.
By adopting the seal chamber length defined in this embodiment, an excellent diffusion preventing effect can be obtained.

(4) An apparatus for producing an aluminum film according to an embodiment of the present invention is an aluminum film in which aluminum is electrodeposited on the surface of a long porous resin substrate provided with conductivity in a molten salt electrolyte. Manufacturing equipment,
A plating chamber;
A seal chamber provided on each of the inlet side and the outlet side of the substrate of the plating chamber;
Have
The seal chambers are provided on each of an inlet side and an outlet side of the base material;
Having at least one diffusion prevention plate that divides a space between the seal rolls in the seal chamber into a plurality of chambers in the transport direction of the porous resin substrate,
Aluminum film manufacturing equipment,
It is.
This embodiment provides an apparatus for manufacturing an aluminum film that reliably prevents moisture and oxygen in the outside air from entering the plating chamber by means of a diffusion prevention plate provided in the seal chamber.

The method and apparatus for producing an aluminum film according to the present invention will be described in detail below.
In addition, this invention is not limited to this, It is shown by the claim, and it is intended that all the changes within the meaning and range equivalent to a claim are included.

An apparatus for producing an aluminum film according to the present invention includes an aluminum film that transports a base material into a plating solution accommodated in a plating chamber and electrodeposits aluminum onto the base material to form an aluminum film on the base material. It is a manufacturing apparatus. The aluminum film manufacturing apparatus includes a plating chamber in which a plating solution is stored, an inlet-side seal chamber provided with a seal roll provided on the inlet side of the plating chamber for carrying the substrate into the plating chamber, and a base after plating. And an outlet side seal chamber provided with a seal roll provided on the outlet side of the plating chamber for carrying the material out of the plating chamber.
The inlet side seal chamber and the outlet side seal chamber are provided to prevent moisture and oxygen contained in the outside air from entering the plating chamber. A seal roll is provided in the seal chamber.

When an aluminum film is formed on a normal substrate by plating, moisture can be sufficiently blocked even by a seal chamber provided with only a seal roll. However, when aluminum is electroplated on a resin molded body having a three-dimensional network structure (hereinafter also referred to as a resin porous body), the moisture blocking effect is not sufficient only with the seal roll.
This is because the porous resin body sandwiched between the seal rolls is porous, so the porous resin body has continuous pores, the concentration of moisture and oxygen in the nitrogen gas atmosphere in the plating chamber, and the concentration of moisture or oxygen in the outside air It is assumed that the cause is that moisture and oxygen diffuse into the plating chamber through the holes.
In particular, when a washing device is provided to remove the plating solution remaining on the surface of the substrate on which the aluminum film is formed behind the outlet side seal chamber, the moisture concentration in the vicinity of the washing device increases, and the moisture is diffused. It is presumed that it enters the plating chamber.

Therefore, when the present inventor provided a diffusion prevention plate for preventing the diffusion of moisture in addition to providing a seal roll in the seal chamber, it was possible to reliably prevent moisture from entering the plating chamber.
In the following, an outline of each process for producing an aluminum film by electroplating aluminum on a resin molded body having a three-dimensional network structure (hereinafter also referred to as “resin porous body”) is described. A specific configuration will be described in detail.

(Outline of aluminum film manufacturing process)
FIG. 4 is a flowchart showing a manufacturing process of the aluminum porous body. FIG. 5 schematically shows a state in which an aluminum film is formed using a porous resin base material (hereinafter sometimes referred to as “resin porous body”) as a base material corresponding to the flow diagram. is there. The flow of the entire manufacturing process will be described with reference to both drawings.

  First, preparation 101 of the porous resin body is performed. FIG. 5A is an enlarged schematic view in which the surface of a porous resin body having continuous air holes is enlarged as an example of the porous resin body. The pores are formed with the resin porous body 31 as a skeleton. Next, the surface 102 of the resin porous body is made conductive. Through this step, a thin conductive layer 32 made of a conductive material is formed on the surface of the porous resin body 1 as shown in FIG.

Subsequently, aluminum plating 103 in molten salt is performed, and an aluminum film 33 is formed on the surface of the porous resin body on which the conductive layer is formed (FIG. 5C). Thus, an aluminum structure having an aluminum film 33 formed on the surface using the resin porous body as a base material is obtained. If necessary, the base resin is removed 104 from the aluminum structure.
The porous aluminum body 33 in which only the metal layer remains can be obtained by dissociating the porous resin body 1 by decomposition or the like (FIG. 5D).
Hereinafter, each step will be described in order.

(Preparation of porous resin substrate)
A porous resin body having a three-dimensional network structure and continuous air holes is prepared. Arbitrary resin can be selected as the material of the resin porous body. Examples of the material include foamed resin moldings such as polyurethane, melamine, polypropylene, and polyethylene. Although described as a foamed resin molded article, a resin molded article having an arbitrary shape can be selected as long as it has continuous pores (continuous vent holes). For example, what has a shape like a nonwoven fabric entangled with a fibrous resin can be used instead of the foamed resin molded article. The foamed resin molded article preferably has a porosity of 80% to 98% and a pore diameter of 50 μm to 500 μm. Foamed urethane and foamed melamine can be preferably used as a foamed resin molded article because they have high porosity, have pore connectivity and are excellent in thermal decomposability.
Urethane foam is preferable in terms of pore uniformity and availability, and urethane foam is preferable in that a material having a small pore diameter can be obtained.

The resin porous body often has residues such as foaming agents and unreacted monomers in the foam production process, and it is preferable to perform a washing treatment for the subsequent steps. The resin base material constitutes a three-dimensional network as a skeleton, thereby constituting continuous pores as a whole. The urethane skeleton has a substantially triangular shape in a cross section perpendicular to the extending direction. Here, the porosity is defined by the following equation.
Porosity = (1− (weight of resin porous body [g] / (volume of resin porous body [cm ³ ] × material density))) × 100 [%]
In addition, the pore diameter is averaged as an average pore diameter = 25.4 mm / cell number by enlarging the surface of the resin base material with a micrograph and counting the number of pores per inch (25.4 mm) as the number of cells. Find the value.

(Conductivity on the surface of porous resin)
In order to perform electroplating, the surface of the foamed resin is subjected to a conductive treatment in advance.
In the present invention, a conductive coating containing conductive particles such as carbon is applied to the surface of the foamed resin to conduct the conductive treatment.
First, a carbon paint as a conductive paint is prepared. The suspension as the conductive paint preferably contains carbon particles, a binder, a dispersant and a dispersion medium. In order to uniformly apply the conductive particles, the suspension needs to maintain a uniform suspension state. For this reason, it is preferable that the suspension is maintained at 20 ° C to 40 ° C. The reason is that when the temperature of the suspension is lower than 20 ° C., the uniform suspension state is lost, and only the binder is concentrated on the surface of the skeleton forming the network structure of the porous resin body to form a layer. Because. In this case, the applied carbon particle layer is easy to peel off, and it is difficult to form a metal plating that is firmly adhered. On the other hand, when the temperature of the suspension exceeds 40 ° C., the amount of evaporation of the dispersant is large, and the suspension is concentrated as the coating treatment time elapses, and the amount of carbon applied tends to fluctuate. The particle size of the carbon particles is 0.01 to 5 μm, preferably 0.01 to 0.5 μm. If the particle size is large, it becomes a factor that clogs pores of the resin porous body or inhibits smooth plating, and if it is too small, it is difficult to ensure sufficient conductivity.

The carbon particles can be applied to the resin porous body by immersing the target resin porous body in the suspension, and performing squeezing and drying.
FIG. 6 is a diagram schematically showing a configuration example of a processing apparatus that conducts a band-shaped porous resin body serving as a skeleton as an example of a practical manufacturing process. As shown in the figure, this apparatus includes a supply bobbin 52 for supplying a long resin base material (hereinafter also referred to as “band-shaped resin”) 51, a tank 55 containing a suspension 54 of conductive paint, and an upper part of the tank 55. A pair of squeezing rolls 57, a plurality of hot air nozzles 56 provided opposite to the side of the belt-shaped resin 51 that travels, and a winding bobbin 58 that winds up the strip-shaped resin 51 after processing. ing. Further, a deflector roll 53 for guiding the belt-shaped resin 51 is appropriately disposed. In the apparatus configured as described above, the strip-shaped resin 51 having a three-dimensional network structure is unwound from the supply bobbin 52, guided by the deflector roll 53, and immersed in the suspension in the plating chamber 55. . The strip-shaped resin 51 immersed in the suspension 54 in the tank 55 changes its direction upward and travels between the squeeze rolls 57 above the liquid level of the suspension 54. At this time, the distance between the squeezing rolls 57 is smaller than the thickness of the belt-shaped resin 51, and the belt-shaped resin 51 is compressed. Therefore, the excessive suspension impregnated in the belt-shaped resin 51 is squeezed out and returned to the tank 55.

  Subsequently, the strip-shaped resin 51 changes the traveling direction again. Here, the dispersion medium of the suspension is removed by the hot air blown by the hot air nozzle 56 composed of a plurality of nozzles, and the belt-shaped resin 51 is wound around the winding bobbin 58 after sufficiently drying. The temperature of the hot air ejected from the hot air nozzle 56 is preferably in the range of 40 ° C to 80 ° C. When the apparatus as described above is used, the conductive treatment can be carried out automatically and continuously, and a skeleton having a network structure without clogging and having a uniform conductive layer is formed. The metal plating in the next process can be performed smoothly.

(Formation of aluminum film: Molten salt plating)
Next, electrolytic plating is performed in a molten salt to form an aluminum film on the surface of the porous resin body.
By performing aluminum plating in a molten salt bath, a thick aluminum film can be uniformly formed on the surface of a complicated skeleton structure such as a resin porous body having a three-dimensional network structure.
A direct current is applied in molten salt with the porous resin body having a conductive surface as the cathode and aluminum as the anode.
As the molten salt, an organic molten salt that is a eutectic salt of an organic halide and an aluminum halide, or an inorganic molten salt that is a eutectic salt of an alkali metal halide and an aluminum halide can be used. Use of an organic molten salt bath that melts at a relatively low temperature is preferable because plating can be performed without decomposing the porous resin body as a base material. As the organic halide, imidazolium salt, pyridinium salt and the like can be used. Specifically, 1-ethyl-3-methylimidazolium chloride (EMIC) and butylpyridinium chloride (BPC) are preferable.
Since the molten salt deteriorates when moisture or oxygen is mixed in the molten salt, the plating is preferably performed in an atmosphere of an inert gas such as nitrogen or argon and in a sealed environment.

As the molten salt bath, a molten salt bath containing nitrogen is preferable, and among them, an imidazolium salt bath is preferably used. When a salt that melts at a high temperature is used as the molten salt, the resin dissolves or decomposes in the molten salt faster than the growth of the plating film, and the plating film cannot be formed on the surface of the porous resin body. The imidazolium salt bath can be used without affecting the resin even at a relatively low temperature. As the imidazolium salt, a salt containing an imidazolium cation having an alkyl group at the 1,3-position is preferably used. In particular, an aluminum chloride-1-ethyl-3-methylimidazolium chloride (AlCl ₃ -EMIC) -based molten salt is used. It is most preferably used because it is highly stable and hardly decomposes. Plating onto foamed urethane resin or foamed melamine resin is possible, and the temperature of the molten salt bath is 10 ° C to 100 ° C, preferably 25 ° C to 45 ° C. The lower the temperature, the narrower the current density range that can be plated, and the more difficult it is to plate on the entire porous body surface. At a high temperature exceeding 100 ° C., a problem that the shape of the base resin is impaired tends to occur.

In molten salt aluminum plating on metal surfaces, it has been reported that additives such as xylene, benzene, toluene and 1,10-phenanthroline are added to AlCl ₃ -EMIC for the purpose of improving the smoothness of the plating surface. The inventors of the present invention have found that when aluminum plating is performed on a resin porous body having a three-dimensional network structure, an effect specific to the formation of the aluminum porous body can be obtained by adding 1,10-phenanthroline. That is, the first feature that the aluminum skeleton forming the porous body is not easily broken and the second feature that uniform plating with a small difference in plating thickness between the surface portion and the inside of the porous body can be obtained. It is.

On the other hand, an inorganic salt bath can be used as the molten salt as long as the resin is not dissolved. The inorganic salt bath is typically a two-component or multi-component salt of AlCl ₃ -XCl (X: alkali metal). Such an inorganic salt bath generally has a higher melting temperature than an organic salt bath such as an imidazolium salt bath, but is less restricted by environmental conditions such as moisture and oxygen, and can be put into practical use at a low cost overall. . When the resin is a foamed melamine resin, it can be used at a higher temperature than the foamed urethane resin, and an inorganic salt bath at 60 ° C. to 150 ° C. is used.

(Plating equipment)
FIG. 1 shows an example of an apparatus for producing an aluminum film according to an embodiment of the present invention.
The aluminum film manufacturing apparatus includes a plating chamber 1, an inlet-side seal chamber 4 provided on the substrate inlet side of the plating chamber 1, and an outlet-side seal chamber 5 provided on the substrate outlet side.
A diffusion prevention plate 7 having an L-shaped cross section as shown in FIG. 2A is provided in the seal chamber.

The base material W fed out from the supply bobbin 9 for feeding the base material passes through the seal roll 6 on the upstream side of the inlet side seal chamber 4 and is conveyed into the seal chamber. In the seal chamber, the diffusion prevention plate 7 is disposed at a position where it does not come into contact with the workpiece W, and prevents moisture and oxygen from entering. The workpiece W is conveyed into the plating chamber 1 through the downstream seal roll 6.
The workpiece W on which the aluminum film is formed in the plating chamber 1 is washed by the washing device 8 through the outlet side seal chamber 5 and then wound on the winding bobbin 10.

-Plating chamber-
As shown in FIG. 1, the plating chamber 1 includes an anode 2 and a plating solution 3.
As the plating chamber 1, a conventionally used one can be used, and either an in-liquid power feeding system or an external liquid power feeding system may be used.
Although FIG. 1 shows that the substrate is conveyed in the plating solution in the horizontal direction, it may be of a type that forms an aluminum film while conveying the workpiece along the circumferential surface of the conveying drum. . Further, the work W is pressed against the power supply roll 12 by the pressing roll 11 and is supplied with power from the power supply roll 12. The plating solution 3 overflows from the plating tank and is stored in the storage tank 14, and is circulated from the storage tank 14 to the plating tank by the pump 13.

-Inlet side seal chamber and outlet side seal chamber The inlet side seal chamber 4 and the outlet side seal chamber 5 may be the same type or different types. Hereinafter, the inlet side seal chamber 4 and the outlet side seal chamber 5 may be simply referred to as “seal chamber”.
2A shows the structure of the seal chamber shown in FIG. 1, and FIG. 2B shows the structure of the diffusion prevention plate 7. As shown in FIG.
The seal chamber is divided into a plurality of chambers by at least one diffusion prevention plate 7, and the end of the diffusion prevention plate 7 is arranged at a predetermined interval from the workpiece.

In the case shown in FIG. 2A, the diffusion prevention plate 7 has an L-shaped cross section.
The diffusion prevention plate 7 having an L-shaped cross section has a horizontal portion of length b at the end portion on the workpiece side, and this horizontal portion forms a gap a with a predetermined interval from the workpiece W. While allowing the workpiece W to pass, it prevents diffusion of moisture and oxygen.
The diffusion prevention plate may be provided so that the L shape shown in FIG.

One diffusion prevention plate may be provided, but a plurality of diffusion prevention plates are preferably provided. When only one sheet is provided, the length b may be increased, and when a plurality of sheets are provided, the length b may be decreased.
Further, the gap a is preferably as small as possible, but in reality it is 0.5 mm to 3 mm, and preferably 0.5 to 2 mm. If the gap a is small, the length b may be short, and if the gap a is large, the length b needs to be long.
The b / a ratio is preferably 15 to 600.

The length of the seal chamber can be appropriately set depending on the number, shape, and size of the diffusion prevention plate, but is preferably 300 mm or more.
The longer the length of the seal chamber, the better. However, if the length is too long, there is a problem in terms of space.

FIG. 3 shows another example of the diffusion prevention plate. The diffusion prevention plate shown in FIG. 3 (A) has a T-shaped cross section, and the one shown in FIG. 3 (B) has a flat plate shape. The shape of the diffusion preventing plate is not limited to the above, and any shape can be used as long as it prevents diffusion of moisture and oxygen.
Further, the angle of the vertical portion of the diffusion preventing plate may be perpendicular to the workpiece or may be inclined.

(Washing)
The aluminum structure having an aluminum film formed on the surface of the plated resin porous substrate is sufficiently blown with nitrogen to remove the plating solution, and then washed to obtain an aluminum porous body.
As the cleaning liquid, water is usually used, but an organic solvent may be used.

The aluminum structure (aluminum porous body) which has a resin porous body as a core of skeleton by the above process is obtained. Depending on uses such as various filters and catalyst carriers, the resin and metal composite may be used as they are. In addition, the resin may be removed when used as a metal structure having no resin due to restrictions on the use environment. Removal of the resin can be performed by any method such as decomposition (dissolution) with an organic solvent, molten salt, or supercritical water, and thermal decomposition. Here, methods such as thermal decomposition at high temperatures are simple, but involve oxidation of aluminum. Unlike nickel and the like, aluminum is difficult to reduce once oxidized. For example, when used as an electrode material for a battery or the like, it cannot be used because conductivity is lost due to oxidation.
For this reason, a method of removing the resin by thermal decomposition in a molten salt described below is preferably used so that oxidation of aluminum does not occur.

(Resin removal: thermal decomposition in molten salt)
Thermal decomposition in the molten salt is performed by the following method. A resin molded body having an aluminum film formed on the surface is immersed in a molten salt and heated while applying a negative potential to the aluminum film to decompose the foamed resin molded body. When a negative potential is applied while being immersed in the molten salt, the foamed resin molded product can be decomposed without oxidizing aluminum. Although heating temperature can be suitably selected according to the kind of foaming resin molding, in order not to melt aluminum, it is necessary to process at the temperature below melting | fusing point (660 degreeC) of aluminum. A preferable temperature range is 500 ° C. or more and 600 ° C. or less. The amount of negative potential to be applied is on the minus side of the reduction potential of aluminum and on the plus side of the reduction potential of cations in the molten salt.

As the molten salt used for the thermal decomposition of the resin, a salt of an alkali metal or alkaline earth metal halide that makes the electrode potential of aluminum base can be used. Specifically, it is preferable to include one or more selected from the group consisting of lithium chloride (LiCl), potassium chloride (KCl), sodium chloride (NaCl), and aluminum chloride (AlCl ₃ ). By such a method, an aluminum porous body having continuous air holes, a thin oxide layer on the surface and a small amount of oxygen can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, these Examples are illustrations and this invention is not limited to these. The scope of the present invention is defined by the scope of the claims, and includes meanings equivalent to the scope of the claims and all modifications within the scope.

[Example 1]
The aluminum plating film was formed in the resin porous base material using the aluminum apparatus which concerns on embodiment of this invention shown in FIG. The plating conditions were as follows.
(Porous resin substrate)
As the base material, urethane foam having a width of 1 m, a thickness of 1 mm, a porosity of 95% by volume, and a pore number (cell number) of about 50 per inch was prepared. The urethane foam was immersed in a carbon suspension and dried to impart conductivity. The components of the carbon suspension included 17% by mass of graphite and carbon black, 7% by mass of a resin binder, and further included a penetrant and an antifoaming agent. The particle size of carbon black was 0.5 μm.

(Seal room)
The length of the inlet side seal chamber 4 and the outlet side seal chamber 5 was 500 mm and the height was 200 mm.
An L-shaped diffusion preventing plate was used, and the gap a, length b, and number c were as follows.
a: 2 mm
b: 40 mm
c: 12

(Plating conditions)
The plating conditions were as follows.
Composition of plating solution: AlCl ₃ / EMIC = 2 mol / 1 mol
Energizing current: 5000A
Workpiece: urethane foam (thickness 1mm, width 1000mm, hole diameter 0.5mm)
Work speed: 700 mm / min Work immersion length: 2.5 m

(Evaluation)
After operating the above plating apparatus for 24 hours, nitrogen gas, which is the atmospheric gas in the plating chamber, is collected by suction with an air pump, and the dew point, hydrogen chloride concentration, and oxygen concentration are respectively measured as a dew point meter (capacitance type), It measured using the hydrogen chloride concentration meter and the oxygen concentration meter. Note that the dew point and the hydrogen chloride concentration are indicators of water content.
The measurement results were as follows.
Dew point: -42 ° C
Oxygen concentration: 0.2 vol%
Hydrogen chloride concentration: 2.5ppm

[Example 2]
Plating was performed in the same manner as in Example 1 except that an L-shaped diffusion preventing plate was used and the gap a, length b, and number c were as follows.
a: 0.5 mm
b: 240 mm
c: 2 pieces Nitrogen gas in the plating chamber was collected and analyzed for its dew point, oxygen concentration and hydrogen chloride concentration.
The measurement results were as follows.
Dew point: -48 ° C
Oxygen concentration: 0.1 vol%
Hydrogen chloride concentration: 1.8ppm

[Example 3]
Plating was performed in the same manner as in Example 1 except that the diffusion prevention plate was replaced with a flat plate, and nitrogen gas in the plating chamber was collected and analyzed for dew point, oxygen concentration, and hydrogen chloride concentration.
The measurement results were as follows.
Dew point: -40 ° C
Oxygen concentration: 0.3 vol%
Hydrogen chloride concentration: 2.9ppm

[Example 4]
Plating was performed in the same manner as in Example 1 except that the length of the seal chamber was 290 mm. Nitrogen gas in the plating chamber was collected, and its dew point, oxygen concentration, and hydrogen chloride concentration were analyzed.
The specific results were as follows.
Dew point: -39 ° C
Oxygen concentration: 0.3 vol%
Hydrogen chloride concentration: 3.1ppm

[Comparative Example 1]
Plating was performed in the same manner as in Example 1 except that only a sealing roll was provided without providing a diffusion prevention plate in the sealing chamber, and the length of the sealing chamber was set to 150 mm. Nitrogen gas in the plating chamber was supplied in the same manner as in Example 1. analyzed.
The measurement results were as follows.
Dew point: -10 ° C
Oxygen concentration: 2.2 vol%
Hydrogen chloride concentration: 25ppm

[Comparative Example 2]
Plating was performed in the same manner as in Example 1 except that no diffusion prevention plate was provided in the seal chamber, and nitrogen gas in the plating chamber was analyzed in the same manner as in Example 1.
The measurement results were as follows.
Dew point: -14 ° C
Oxygen concentration: 1.9 vol%
Hydrogen chloride concentration: 18ppm

DESCRIPTION OF SYMBOLS 1 Plating chamber 2 Anode 3 Plating solution 4 Inlet side seal chamber 5 Outlet side seal chamber 6 Seal roll 7 Diffusion prevention plate 8 Flushing device 9 Supply bobbin 10 Winding bobbin 11 Pressing roll 12 Feed roll 13 Pump 14 Liquid storage tank 31 Resin porous Body 32 Conductive layer 33 Aluminum film 51 Long porous resin substrate (band-shaped resin)
52 Supply Bobbin 53 Deflector Roll 54 Conductive Paint Suspension 55 Tank 56 Hot Air Nozzle 57 Drawing Roll 58 Winding Bobbin

Claims (4)

In a molten salt electrolyte, a method for producing an aluminum film in which aluminum is electrodeposited on the surface of a long porous resin base material provided with conductivity,
Carrying the substrate into the plating chamber through a seal chamber provided on the inlet side of the plating chamber;
Electrodepositing an aluminum film on the surface of the porous resin substrate in the plating chamber;
Carrying out the porous resin base material electrodeposited with the aluminum film from the plating chamber through a seal chamber provided on the outlet side of the plating chamber,
Seal rolls are respectively provided on the inlet side and the outlet side of the seal chamber,
The space between the seal rolls in the seal chamber is partitioned into a plurality of chambers in the transport direction of the porous resin substrate by at least one diffusion prevention plate,
One end of the diffusion preventing plate is disposed at a distance from the porous resin substrate,
A method for producing an aluminum film.   The method for producing an aluminum film according to claim 1, wherein the diffusion preventing plate is a plate having an L-shaped cross section, a plate having a T-shaped cross section, or a flat plate.   The method for producing an aluminum film according to claim 1, wherein the seal chamber has a length in the transport direction of the porous resin base material of 300 mm or more. An apparatus for producing an aluminum film in which aluminum is electrodeposited on the surface of a long porous resin base material provided with conductivity in a molten salt electrolyte,
A plating chamber;
A seal chamber provided on each of the inlet side and the outlet side of the substrate of the plating chamber;
Have
The seal chambers are provided on each of an inlet side and an outlet side of the base material;
Having at least one diffusion prevention plate that divides a space between the seal rolls in the seal chamber into a plurality of chambers in the transport direction of the porous resin substrate,
Aluminum film manufacturing equipment.

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