KR20200007784A - Manufacturing method of aluminum plating film and aluminum plating film - Google Patents

Abstract

An aluminum plating film containing aluminum as a main component, wherein the aluminum plating film includes an intervening layer containing a metal having a smaller ionization tendency than aluminum, or a metal having a smaller ionization tendency than aluminum between the coated surfaces at both ends in the thickness direction. An aluminum plating film which has an intervening layer containing the alloy of.

Description

Manufacturing method of aluminum plating film and aluminum plating film

The present disclosure relates to an aluminum plated film and a method for manufacturing the aluminum plated film.

This application claims the priority based on Japanese Patent Application No. 2017-097138 of an application on May 16, 2017, and uses all the description content described in the said Japanese application.

Patent Document 1 describes the arrangement of a porous plate made of an insulator between the substrate and the anode. By adjusting the opening ratio of the porous plate described in Patent Literature 1 along the advancing direction of the substrate, it is said that the current density distribution in the advancing direction of the substrate can be made uniform to form an aluminum plated film having no thickness variation.

Patent Literature 2 discloses a plating bath having a cell structure in which an upper tank and a lower tank are connected in two passages, a sink roll disposed in the lower tank, and a feed roll disposed outside the plating tank located above the upper tank. It is described to form an aluminum plating film on a base material using the continuous electrical processing apparatus provided. According to the continuous electroprocessing apparatus of patent document 2, it is supposed that an aluminum plating film can be formed in the surface of a base material several times by reciprocating a base material between a feed roll and a sink roll a plurality of times.

Japanese Patent Application Laid-Open No. 10-317195 Japanese Patent Application Laid-Open No. 11-117089

An aluminum plated film of the present disclosure is an aluminum plated film containing aluminum as a main component, and the aluminum plated film includes an intercalation layer containing a metal having a smaller ionization tendency than aluminum between coating surfaces at both ends in the thickness direction. Or an aluminum plated film having an intervening layer containing an alloy of a metal and aluminum having a smaller ionization tendency than aluminum.

The manufacturing method of the aluminum plating film of this indication is a method of manufacturing the aluminum plating film of this indication, Electrodepositing aluminum to the surface of the said base material by electrolytically treating the base material which is electroconductive at least in the 1st electrolyte solution, and free aluminum After the first electrolytic treatment step of forming a pre-aluminum plating film and after the first electrolytic treatment step, the prealuminum plating film contains a metal having a smaller ionization tendency than aluminum and the first electrolyte solution. And replacing the surface of the prealuminum plating film with a metal having a smaller ionization tendency than aluminum to form a substituted plating film, and subjecting the substituted plating film to electrolytic treatment in the second electrolyte after the substitution process. A second electrode which deposits aluminum on the surface of the film to form an aluminum plated film Having a treatment process, wherein the first electrolyte and the second electrolyte solution is a molten salt of aluminum plated film production method comprising at least aluminum chloride.

1 is an enlarged view showing an outline of a cross section of an example of an aluminum plated film according to an embodiment of the present disclosure.
2 is an enlarged view showing an outline of a cross section of another example of the aluminum plating film according to the embodiment of the present disclosure.
3 is an enlarged view showing an outline of a partial cross section of still another example of the aluminum plating film according to the embodiment of the present disclosure.
4 is an enlarged view illustrating an outline of a cross-sectional view taken along the line AA of FIG. 3.
5 is a photograph of a foamed urethane resin as an example of a resin molded article having a skeleton of a three-dimensional network structure.
6 is an enlarged view showing an outline of a partial cross section of an example of a state in which a conductive layer is formed on a surface of a skeleton of a resin molded body having a skeleton having a three-dimensional network structure.
It is a photograph which shows the result of having observed the cross section of the aluminum plating film No. 3 produced in Example 3 with the scanning electron microscope.
FIG. 8 is a photograph showing the result of observing the cross section of the aluminum plating film No. 4 prepared in Example 4 with a scanning electron microscope. FIG.
9 is a photograph showing the result of observing the cross section of aluminum plating film No. 7 prepared in Comparative Example 2 with a scanning electron microscope.

(Form to carry out invention)

Problems to be Solved by the Present Disclosure

A molten salt bath is used for electroplating aluminum, but since molten salt has low electrical conductivity, an aluminum plating film cannot be formed at high speed. In particular, when the substrate has an elongated shape such as a steel strip, an aluminum plated film having a sufficient thickness cannot be formed in the plating bath without slowing down the conveying speed. Although the method of patent document 1 says that the thickness of an aluminum plating film can be made uniform, when thickening an aluminum plating film, a conveyance speed will inevitably fall and production efficiency will become low.

In addition, when a base material is a sheet form like a steel strip, the continuous electric processing apparatus as described in patent document 2 cannot be used. Since the base material is a wire rod, the continuous electroprocessing apparatus described in Patent Literature 2 can reciprocate a plurality of times between a feed roll and a sink roll, and in the case of a sheet-shaped substrate, a plurality of reciprocates between a feed roll and a sink roll a plurality of times. Can't. Moreover, since aluminum is not electrodeposited on the base material surface of the part which contacts the sink roll in a plating tank, a nonuniformity will arise in the thickness of an aluminum plating film.

Then, the present inventors examined the formation of a thick aluminum plating film with high efficiency by using a plurality of plating apparatuses which convey a base material horizontally and forming an aluminum plating film, and forming an aluminum plating film in multisteps, and raising a conveyance speed. However, since aluminum is a metal that is very easily oxidized, an oxide film is formed when the substrate is pulled out of the molten salt bath, and when aluminum plating is performed in multiple stages, an oxide film is inserted between the aluminum plating films formed in each plating apparatus. Discarding was found. Even when molten salt aluminum plating was performed in nitrogen atmosphere (N ₂ : 99.99% or more) or argon atmosphere (Ar: 99.99% or more), an oxide film was formed on the surface of the aluminum plated film by very little oxygen contained in the atmosphere. .

In addition, since the oxide film formed on the surface of the aluminum plated film is very dense and strong, and cannot be uniformly energized, the adhesion between the aluminum plated films formed in stages is poor, and it is found that this may cause defects such as swelling. It became.

Therefore, an object of this disclosure is to provide the aluminum plating film | membrane which can be manufactured in a short time with a thick film thickness at low cost, and its manufacturing method.

[Effect of this disclosure]

According to the present disclosure, it is possible to provide an aluminum plated film which can be manufactured in a short time with a high film thickness and low cost, and a method for producing the same.

[Description of Embodiment of the Present Disclosure]

First, an embodiment of the present disclosure will be described in detail.

(1) The aluminum plating film which concerns on embodiment of this indication is an aluminum plating film which has aluminum as a main component, The said aluminum plating film contains the metal whose ionization tendency is smaller than aluminum between the film surfaces of the both ends of a thickness direction. It is an aluminum plating film which has an intervening layer which consists of an intercalation layer or an alloy of an aluminum and a metal whose ionization tendency is smaller than aluminum.

According to embodiment of the invention as described in said (1), the aluminum plating film which is thick and can be manufactured in a short time at low cost can be provided.

(2) It is preferable that the said aluminum plating film of said (1) is a long sheet shape. According to embodiment of the invention as described in said (2), the aluminum plating film which can be manufactured in a short time at low cost on the surface of a thick, elongate, sheet-like base material can be provided.

(3) It is preferable that the aluminum plating film of said (1) forms the said frame | skeleton of the metal porous body which has a frame | skeleton of a three-dimensional network structure.

According to embodiment of the invention as described in said (3), the thickness of frame | skeleton can provide the aluminum plating film which comprises the frame | skeleton of the porous metal body which can be manufactured in a short time at low cost.

(4) It is preferable that the said metal porous body of the aluminum plating film of said (3) is elongate sheet shape.

According to embodiment of the invention as described in said (4), the thickness of frame | skeleton is thick, it is possible to manufacture in a short time at low cost, and also provides the aluminum plating film which comprises the frame | skeleton of the metal porous body which has the shape of the elongate and sheet form as a whole. can do.

(5) It is preferable that the aluminum plating film in any one of said (1)-(4) has several said intervening layer in the thickness direction of the said aluminum plating film.

According to embodiment of the invention as described in said (5), the aluminum plating film which can be manufactured more thickly and can be manufactured in a short time at low cost can be provided.

(6) In the aluminum plated film according to any one of the above (1) to (5), a metal having a smaller ionization tendency than aluminum includes iron (Fe), zinc (Zn), zirconium (Zr), and manganese (Mn). And at least one selected from the group consisting of nickel (Ni) and copper (Cu).

According to embodiment of the invention as described in said (6), the aluminum plating film with high electrical conductivity can be provided.

(7) It is preferable that the thickness of the said aluminum plating film of the aluminum plating film in any one of said (1)-(6) is 10 micrometers or more and 1000 micrometers or less.

According to embodiment of the invention as described in said (7), the aluminum plating film which can be manufactured in a short time at a thicker film thickness and low cost can be provided.

(8) The manufacturing method of the aluminum plating film which concerns on embodiment of this indication is a method of manufacturing the aluminum plating film of said (1), The surface of the said base material is electrolytically processed at least the base material which is electroconductive in 1st electrolyte solution. In the first electrolytic treatment step of electrodepositing aluminum to form a prealuminum plating film, and after the first electrolytic treatment step, the prealuminum plating film is subjected to a substitution liquid containing a metal having a smaller ionization tendency than aluminum and the first electrolyte solution. Substitution process of immersing and substituting the surface of the said prealuminum plating film with metal whose ionization tendency is smaller than aluminum, and forming a substituted plating film, and electrolytically treating the said substituted plating film in a 2nd electrolyte solution after the said substitution process of the said substituted plating film Second electrolytic treatment for depositing aluminum on the surface to form an aluminum plated film It has a li process, The said 1st electrolyte solution and the said 2nd electrolyte solution are the manufacturing methods of the aluminum plating film which is a molten salt containing at least aluminum chloride.

According to embodiment of the invention as described in said (8), the manufacturing method of the aluminum plating film which can manufacture the aluminum plating film with a thick film thickness in a short time at low cost can be provided.

(9) It is preferable that the said base material is a resin molded object which has a skeleton of a three-dimensional network structure in the manufacturing method of the aluminum plating film of said (8).

According to embodiment of the invention as described in said (9), the aluminum plating film which can be manufactured in a short time at low cost on the surface of the base material which has a thick film | membrane and has a skeleton of a three-dimensional network structure can be provided.

(10) It is preferable that the manufacturing method of the aluminum plating film as described in said (8) or (9) has a removal process which removes the said base material after the said 2nd electrolytic treatment process.

According to embodiment of the invention as described in said (10), the manufacturing method of the aluminum plating film which can manufacture the aluminum plating film as described in said (3) can be provided.

[Details of Embodiments of the Present Disclosure]

The specific example of the aluminum plating film which concerns on embodiment of this indication, and its manufacturing method is demonstrated below. In addition, this indication is not limited to these illustrations, It is indicated by the claim, and it is intended that the meaning of a Claim and equality, and all the changes within a range are included.

<Aluminum plating film>

The aluminum plating film which concerns on embodiment of this indication has aluminum as a main component, and has an intervening layer between the coating surfaces of both ends of a thickness direction. In addition, having aluminum as a main component means that the content rate of aluminum in an aluminum plating film is 50 mass% or more.

In FIG. 1, the enlarged schematic diagram which expanded the cross section of an example of the aluminum plating film which concerns on embodiment of this indication is shown. As shown in FIG. 1, the aluminum plating film 10 has the intervening layer 12 between the coating surfaces 11 and 11 'of the both ends of the thickness direction. The aluminum plating film 10 may be formed on the surface of the base material which is not shown in figure. When the aluminum plating film 10 is formed on the surface of the base material, either of the coating surfaces of the film surfaces 11 and 11 'is in close contact with the surface of the base material. When a base material is a long sheet shape, the aluminum plating film 10 formed in the surface of the said base material also becomes a long sheet shape.

The intervening layer 12 is a layer containing a metal whose ionization tendency is smaller than aluminum or a layer containing an alloy of a metal and aluminum whose ionization tendency is smaller than aluminum. The intervening layer 12 is formed on a surface substantially parallel to the coating surfaces 11 and 11 'of the aluminum plating film. When the aluminum plating film 10 is formed on the surface of a flat base material, the intervening layer 12 is substantially parallel to the coating surfaces 11 and 11 'over almost the entire aluminum plating film 10. have. In the case where the aluminum plating film 10 is formed on the surface of a substrate having a complex three-dimensional shape, the intervening layer 12 is partially parallel to the coating surfaces 11 and 11 'of the aluminum plating film 10. There are many cases.

The thickness of the intervening layer 12 is preferably as thin as possible, and may be a monoatomic layer. Although the upper limit of the intervening layer 12 is not specifically limited, For example, what is necessary is just about 500 nm or less. As the thickness of the intervening layer 12 is thinner, the adhesion between the aluminum layers formed on both sides of the intervening layer 12 is increased, and the electrical conductivity of the aluminum plating film can be prevented from decreasing. As for the thickness of the intervening layer 12, it is more preferable that they are 1 nm or more and 400 nm or less, and it is still more preferable that they are 10 nm or more and 200 nm or less.

The intervening layer of the aluminum plating film according to the embodiment of the present disclosure can be confirmed by observing, for example, the cross section of the aluminum plating film with a scanning electron microscope (SEM) or a transmission electron microscope (TEM). When the thickness of the intervening layer is about 50 nm or more, it can be confirmed by SEM. In addition, when the thickness of an intervening layer is less than about 50 nm, it can confirm by element mapping by TEM.

2 is an enlarged schematic view showing an enlarged cross section of another example of the aluminum plated film according to the embodiment of the present disclosure. As shown in FIG. 2, it is preferable that the aluminum plating film 20 has a plurality of intervening layers 22 between the coating surfaces 21, 21 ′ of both ends in the thickness direction. Since the aluminum plating film 20 has the some intervening layer 22, it can manufacture more in a short time at low cost. When providing a plurality of intervening layers, the intervening layers are also substantially parallel.

As a metal whose ionization tendency which comprises an intervening layer is smaller than aluminum, a group which consists of iron (Fe), zinc (Zn), zirconium (Zr), manganese (Mn), nickel (Ni), and copper (Cu), for example. It is preferable that it is any 1 or more types chosen from. Since these metals have sufficiently high electrical conductivity, even if they exist as intervening layers in the aluminum plating film, the electrical conductivity of the aluminum plating film is not lowered.

When the metal whose ionization tendency is smaller than aluminum is Fe, Zn, Cu, or Ni, an aluminum plated film can be produced relatively inexpensively.

When the metal whose ionization tendency is smaller than aluminum is Zr, the adhesiveness of the aluminum layers formed in both sides of an intervening layer can be improved more.

When the metal whose ionization tendency is smaller than aluminum is Mn, since corrosion resistance is high, an aluminum plating film can be used suitably also as an electrical power collector, such as a nonaqueous electrolyte battery.

In addition, in the interlayer, the metal whose ionization tendency is smaller than aluminum may form an alloy with aluminum.

In the case where the aluminum plated film is formed on the surface of the substrate, the thickness of the aluminum plated film is preferably greater from the viewpoint of protecting the substrate, and is preferably about 10 μm or more. Moreover, when the thickness of an aluminum plating film is 10 micrometers or more, the breaking strength of an aluminum plating film can be made high. It is preferable that the thickness of an aluminum plating film is about 1000 micrometers or less from a viewpoint of manufacturing cost or weight reduction. From these viewpoints, it is more preferable that thickness of an aluminum plating film is 15 micrometers or more and 700 micrometers or less, and it is still more preferable that they are 20 micrometers or more and 500 micrometers or less.

Conventionally, in order to manufacture the aluminum plating film whose thickness is 10 micrometers or more, it takes a lot of time, and it was very difficult to form the aluminum plating film which is long, sheet-like, and thickness is 10 micrometers or more.

In contrast, the aluminum plated film according to the embodiment of the present disclosure can be manufactured in a short time at a low cost even if the thickness is 10 µm or more, and it is also possible to easily manufacture a long and sheet-shaped material. Moreover, since the aluminum plating film which concerns on embodiment of this indication is dense and there is no gap in a film | membrane, even if it thickens, thickness does not fall and an electrical conductivity is about the same as a rolled foil.

The aluminum plating film which concerns on embodiment of this indication may form the said frame | skeleton 33 of the porous metal body which has the frame | skeleton 33 of a three-dimensional network structure, as shown in FIG. In the example shown in FIG. 3, although the inside 34 of the frame | skeleton 33 is hollow, the base material may exist in the inside 34 of the frame | skeleton 33. As shown in FIG. The metal porous body has communication pores, and the pores 35 are formed by the skeleton 33.

In FIG. 4, the schematic enlarged view of the cross section along the A-A line of FIG. 3 is shown. As shown in FIG. 4, the aluminum plating film 30 which comprises the frame | skeleton 33 of a metal porous body has the intervening layer 32 between the coating surfaces 31 and 31 'of both ends of a thickness direction. have. As shown in FIG. 4, the intervening layer 32 is ideally substantially parallel to the coating surfaces 31 and 31 ′. However, in the aluminum plating film constituting a complex skeleton such as a metal porous body having a skeleton having a three-dimensional network structure, the intervening layer 32 is partially parallel to the coating surfaces 31 and 31 '. It is.

Even if the said metal porous body is a long sheet shape as a whole, since a skeleton is formed by the aluminum plating film which concerns on embodiment of this indication, it can manufacture in a short time at low cost.

What is necessary is just to select the porosity, average pore diameter, and thickness of a metal porous body suitably according to the use of a metal porous body. For example, when using as an electrode (current collector) of a battery, an average pore diameter is small and a thin metal porous body is preferable. In addition, when using for heat radiation, an average pore diameter is large and a thick metal porous body is preferable.

In addition, the porosity of a metal porous body shall mean the ratio of the volume of the space (pore part) inside of a metal porous body with respect to the volume of an external appearance.

The average pore diameter of the metal porous body means the inverse of the number of cells (pieces / inch) formed by the skeleton of the metal porous body.

<Method of Manufacturing Aluminum Plating Film>

The manufacturing method of the aluminum plating film which concerns on embodiment of this indication is a method of manufacturing the aluminum plating film which concerns on said embodiment of this indication, and has a 1st electrolytic treatment process, a substitution process, and a 2nd electrolytic treatment process. In addition, when manufacturing an aluminum plating film with a thicker film thickness, after a 2nd electrolytic treatment process, you may perform it repeatedly by setting a substitution process and an electrolytic treatment process as a set. Thereby, the aluminum plating film which has a some intervening layer in an aluminum plating film can be manufactured. In addition, in the manufacturing method of the aluminum plating film which concerns on embodiment of this indication, you may perform the removal process which removes a base material as needed.

Each process is explained in full detail below.

First Electrolytic Treatment Process

A 1st electrolytic treatment process is a process of electrodepositing aluminum on the surface of a base material by electrolytically treating a base material in electrolyte solution, and forming a pre aluminum plating film.

The electrolytic treatment (molten salt electrolysis) can be performed by placing the substrate and aluminum in an electrolyte solution so as to face each other, connecting the substrate to the cathode side of the rectifier and connecting the aluminum to the anode side, and applying a voltage between both electrodes. What is necessary is just to perform a 1st electrolytic treatment process in inert atmosphere, such as argon gas atmosphere and nitrogen gas atmosphere.

(materials)

The base material is not specifically limited, What is necessary is just to have the use which forms an aluminum plating film. For example, a copper plate, a steel strip, a copper wire, a steel wire, or a resin molded body subjected to a conductive treatment can be used as the substrate. Conventionally, it is very difficult to form an aluminum plated film with a thick film on a long sheet-like substrate, which requires a great deal of time and money. On the other hand, according to the manufacturing method of the aluminum plating film which concerns on embodiment of this indication, even if a base material is a long sheet form, a thick aluminum plating film can be manufactured in a short time at low cost.

As the resin molded article subjected to the conductive treatment, for example, a conductive treatment of the surface of polyurethane, melamine resin, polypropylene, polyethylene, or the like can be used. In addition, the resin molded article subjected to the conductive treatment may be of any shape. However, by using the resin molded article having a skeleton having a three-dimensional network structure, the resin molded article finally has excellent characteristics for applications such as a filter, a catalyst carrier, and a battery electrode. The porous metal body can be produced. It is preferable to use a resin foam as the resin molded article having a skeleton having a three-dimensional network structure. The resin foam may be porous and known or commercially available ones may be used. For example, expanded urethane, expanded styrene, or the like may be used. Among these, foamed urethane is preferable especially from a viewpoint of large porosity. The photograph of foamed urethane resin is shown in FIG. Moreover, also by using the resin molded object which has a nonwoven fabric frame | skeleton, the metal porous body which has a nonwoven fabric frame which can be used suitably for the use of a filter, a catalyst carrier, a battery electrode, etc. can be finally produced.

The figure which expanded the outline of the partial cross section of an example of the base material which electroconductively processed the resin molding which has frame | skeleton of a three-dimensional network structure in FIG. 6 is shown. As shown in FIG. 6, the resin molded body 66 having a skeleton having a three-dimensional network structure has communication pores, and the pores 65 are formed by the skeleton.

Since the skeleton of a metal porous body is formed by forming an aluminum plating film on the surface of the skeleton of the resin molded body 66, the porosity, average pore diameter, and thickness of the porous metal body are determined by the porosity, average pore diameter, and thickness of the resin molded body 66. Approximately the same. For this reason, what is necessary is just to select the porosity, average pore diameter, and thickness of the resin molded body 66 suitably according to the porosity, average pore diameter, and thickness of the metal porous body which are manufacturing purposes. The porosity and average pore diameter of the resin molded body 66 are defined similarly to the porosity and average pore diameter of the metal porous body.

The method of conducting a conductive treatment of the surface of the skeleton of the resin molded body 66 is not particularly limited as long as it is a method capable of forming the conductive layer 67 on the surface of the skeleton of the resin molded body 66. As a material which comprises the conductive layer 67, carbon powders, such as amorphous carbon, such as carbon black, graphite, other than metals, such as nickel, titanium, and stainless steel, are mentioned, for example. Among these, carbon powder is especially preferable, and carbon black is more preferable. In addition, when the conductive layer 67 is formed using amorphous carbon or carbon powder other than metal, the conductive layer 67 is also removed when the resin molded body is removed as necessary.

As a specific example of an electroconductive process, when using nickel, an electroless-plating process, sputtering process, etc. are mentioned preferably, for example. In addition, when using materials, such as metal, such as titanium and stainless steel, carbon black, and graphite, the mixture obtained by adding a binder to the fine powder of these materials arrives at the surface of the skeleton of the resin molding 66 ( The process to apply is mentioned as a preferable method.

As an electroless plating process using nickel, the resin molded body 66 may be immersed in well-known electroless nickel plating baths, such as nickel sulfate aqueous solution containing sodium hypophosphite as a reducing agent, for example. If necessary, before the plating bath is immersed, the resin molded body 66 may be immersed in an activating liquid (a cleaning liquid made by Kanizen) containing a small amount of palladium ions.

As a sputtering process using nickel, the inert gas ionized by, for example, attaching the resin molded body 66 to the substrate holder and then applying a DC voltage between the holder and the target (nickel) while introducing an inert gas. It is good to make it collide with nickel, and to blow up the sputtered nickel particle on the surface of the skeleton of the resin molding 66.

The conductive layer 67 may be formed continuously so as to cover the surface of the skeleton of the resin molded body 66. The weight per unit area of the conductive layer 67 is not limited, preferably 1.0 g / m 2 or more and 30 g / m 2 or less, more preferably 5.0 g / m 2 or more and 20 g / m 2 or less, 7.0 g / m 2 or more, It is more preferable that it is 15 g / m <2> or less.

In addition, the weight per unit area of a conductive layer shall mean the mass of the conductive layer in an apparent unit area of the resin molded object in which the conductive layer was formed in the surface of a skeleton.

(Electrolyte amount)

As the electrolyte solution, a molten salt (ion liquid) which can electrodeposit aluminum on the surface of the substrate may be used. Specifically, the electrolyte may be a molten salt containing aluminum halide, and may contain an additive as appropriate.

As the aluminum halide, for instance, there may be mentioned aluminum chloride (AlCl _3), aluminum bromide (AlBr _3), aluminum iodide (AlI ₃₎ or the like. Among these, aluminum chloride is the most preferable.

As the molten salt, for example, a chloride salt or a fluoride molten salt can be preferably used. As the molten salt of the chloride system, for example, KCl, NaCl, CaCl ₂ , LiCl, RbCl, CsCl, SrCl ₂ , BaCl ₂ , MgCl ₂ , eutectic salts thereof and the like can be used. In addition, as a fluoride-based molten salt, for example, it may be used LiF, NaF, KF, RbF, CsF, MgF _2, CaF _2, SrF _2, BaF _2, or such as a salt thereof the process.

Among the molten salts described above, it is preferable to use KCl, NaCl, CaCl ₂ from the viewpoint of being inexpensive and easy to obtain.

In addition, from the viewpoint of lowering the melting point, the molten salt preferably contains any one or more molten salt-forming compounds selected from the group consisting of alkylimidazolium halides, alkylpyridinium halides and urea compounds. . As a molten salt formation compound, what mixes molten salt at about 110 degrees C or less when mixing with an aluminum halide can be used preferably.

As the alkyl imidazolium halide, for example, imidazolium chloride having an alkyl group (1 to 5 carbon atoms) at 1, 3 position, and an alkyl group (1 to 5 carbon atoms) at 1, 2, 3 position The imidazolium chloride which has, and the imidazolium iodide which has an alkyl group (C1-C5) in 1 and 3 positions, etc. are mentioned.

More specifically, 1-ethyl-3-methylimidazolium chloride (EMIC), 1-butyl-3-methylimidazolium chloride (BMIC), 1-methyl-3-propylimidazolium chloride (MPIC), etc. Although, 1-ethyl-3- methyl imidazolium chloride (EMIC) can be used most preferably among these.

Examples of alkylpyridinium halides include 1-butylpyridinium chloride (BPC), 1-ethylpyridinium chloride (EPC), 1-butyl-3-methylpyridinium chloride (BMPC), and the like. Among these, 1-butylpyridinium chloride is the most preferable.

A urea compound means urea and its derivatives, For example, the compound represented by following formula (1) can be used preferably.

However, in Formula (1), R is a hydrogen atom, an alkyl group of 1-6 carbon atoms, or a phenyl group, and may be same or different.

As the urea compound, urea or dimethyl urea can be particularly preferably used among the above.

In the case of using the above-described molten salt-forming compound, an electrolyte solution suitable for electrodepositing aluminum on the surface of the substrate by mixing the aluminum halide and the molten salt-forming compound in a molar ratio of 1: 1 to 3: 1. Becomes

As an additive, the smoothing agent etc. which can smooth the free aluminum plating film electrodepositiond to the surface of a base material are mentioned, for example.

As the leveling agent, for example, any one or more compounds selected from the group consisting of 1,10-phenanthroline monohydrate, 1,10-phenanthroline monohydrate, and 1,10-phenanthroline are preferable. Available. When electrolyte solution contains these smoothing agents, the smooth and mirror-like free aluminum plating film is obtained.

Substitution process

The substitution step is a step of immersing the prealuminum plating film formed on the surface of the substrate by the first electrolytic treatment step in a substitution liquid to replace the surface of the prealuminum plating film with a metal other than aluminum. Since the substitution liquid is a liquid containing a metal whose ionization tendency is smaller than that of aluminum, the surface of the prealuminum plating membrane can be replaced with a metal whose ionization tendency is smaller than aluminum by immersing the prealuminum plating film in the substrate substitution liquid.

When the prealuminum plating film is taken out from the first electrolytic solution after the first electrolytic treatment step described above, an oxide film is formed on the surface of the prealuminum plating film by oxygen which is very little in the atmosphere. In the substitution process, aluminum on the surface of the prealuminum plating film is eluted in the oxide replacement film, and instead, metal contained in the substitution solution is deposited on the surface of the prealuminum plating film to form a substitution plating film. That is, the aluminum (including an oxide film) on the surface of the prealuminum plating film and the metal contained in the substitution solution are replaced, whereby a layer made of the metal contained in the substitution solution is formed on the surface of the prealuminum plating film. The layer by metal contained in a substitution liquid becomes an intervening layer in the aluminum plating film which concerns on embodiment of this indication.

Since the metal contained in the substitution solution does not form a dense oxide film as compared with aluminum, the aluminum electrodeposited in the second electrolytic treatment step carried out after the substitution step has adhesion with the layer by the metal contained in the second electrolyte solution. Is higher.

The time for performing a substitution process is not specifically limited, What is necessary is just to perform so that the oxide film on the surface of a free aluminum plating film may fully be removed. From the viewpoint of making the thickness of the intervening layer as thin as possible, it is better not to perform the substitution step for longer than necessary. What is necessary is just to perform a substitution process in the range of about 1 second or more and about 1 hour or less depending on the metal contained in a substitution liquid. When it takes time to replace the metal and aluminum contained in the substituent, the time can be shortened by energizing. What is necessary is just to make the temperature of the substitution liquid at the time of performing a substitution process about 20 degreeC or more and 200 degrees C or less.

In the substitution step, the surface of the prealuminum plating film is uniformly substituted with the metal contained in the substitution liquid. For this reason, if a prealuminum plating film is formed uniformly in the surface of a base material in a 1st electrolytic treatment process, the layer by the metal contained in a substitution liquid will be substantially parallel to the surface (coating surface of a prealuminum plating film) of a base material. Is formed.

(Replacement amount)

The substitution liquid may be one in which a metal having a smaller ionization tendency than aluminum is added to the first electrolyte solution used in the first electrolytic treatment step. As the metal having a smaller ionization tendency than aluminum, any one or more metals selected from the group consisting of iron (Fe), zinc (Zn), zirconium (Zr), manganese (Mn), nickel (Ni), and copper (Cu) may be used. It can use preferably.

A substitution liquid can be easily obtained by dissolving the chloride of the metal whose ionization tendency is smaller than aluminum in the 1st electrolyte solution used in a 1st electrolytic treatment process. As the chloride of the metal whose ionization tendency is smaller than that of aluminum, for example, FeCl ₄ , ZnCl ₂ , ZrCl ₄ , MnCl ₂ , NiCl ₂ , CuCl _2, or the like can be used. What is necessary is just to set the density | concentration in the substitution liquid of the chloride of the metal whose ionization tendency is smaller than aluminum to about 10 mmol / L or more and 1 mol / L or less.

Second Electrolytic Treatment Process

A 2nd electrolytic treatment process is a process of electrodepositing aluminum on the surface of a substituted plating film, and forming an aluminum plating film by electrolytically treating the substituted plating film after a substitution process in a 2nd electrolyte solution.

Conventionally, when it is going to form an aluminum plating film in multiple stages, the adhesiveness of the aluminum plating film formed in each step could not be improved by the influence of the oxide film formed in the surface of an aluminum plating film when it pulls out from electrolyte solution. On the other hand, in the manufacturing method of the aluminum plating film which concerns on embodiment of this indication, since the dense oxide film of aluminum is not formed in the surface of the substituted plating film used in a 2nd electrolytic treatment process, the aluminum plating film formed in each step is carried out. The adhesiveness of each other can be raised.

The second electrolytic treatment step can be carried out under the same conditions as the first electrolytic treatment step. That is, in a 1st electrolytic treatment process, a 2nd electrolytic treatment process can be performed similarly to a 1st electrolytic treatment process except using the substituted plating film after a substitution process instead of using a base material. The second electrolytic solution used in the second electrolytic treatment step is not necessarily the same composition as the first electrolytic solution used in the first electrolytic treatment step, but from the viewpoint of preventing the introduction of other components, the first electrolytic treatment step It is preferable to use electrolyte solutions of the same composition in the second electrolytic treatment step.

In addition, when the 1st electrolyte solution and the 2nd electrolyte solution are the same composition, it is preferable to separate each plating tank separately, but from a viewpoint of space saving, the plating bath used at the 1st electrolytic treatment process is again performed by a 2nd electrolytic treatment process. It is also possible to use. In the second electrolytic treatment step, when aluminum is uniformly electrodeposited on the surface of the substitution plating film, the layer of the metal contained in the substitution liquid and the surface (film surface) of the aluminum plating film are substantially parallel to each other.

Removal process

Although the aluminum plating film which concerns on embodiment of this indication can be formed in the surface of a base material by a 1st electrolytic treatment process, a substitution process, and a 2nd electrolytic treatment process, when a base material is unnecessary, the removal which removes a base material You may perform a process.

The method of removing a base material is not specifically limited. For example, when a base material is flat form, a base material can be removed by peeling an aluminum plating film from a base material. In addition, when a base material is a resin molded object, a base material can be removed by heat processing, for example. When removing a resin molding by heat processing, what is necessary is just to heat about 400 degreeC or more and 680 degrees C or less, for example in air | atmosphere atmosphere. In addition, when heat-processing, the aluminum plating film by which the metal in the intervening layer alloyed with aluminum is obtained.

Example

EMBODIMENT OF THE INVENTION Hereinafter, although this indication is demonstrated in detail based on an Example, these Examples are an illustration and the aluminum plating film of this indication and its manufacturing method are not limited to these. The scope of the present disclosure is indicated by the scope of the claims, and includes all changes within the meaning and range of equivalency of the claims.

Example 1

<1st electrolytic treatment process>

(materials)

As a base material, the flat copper plate (50 mm x 80 mm x 1 mm) was prepared.

(Electrolyte amount)

As an electrolyte, 1,10-phenanrol chloride as a smoothing agent in a molten salt obtained by mixing a ratio of aluminum chloride (AlCl ₃ ) and 1-ethyl-3-methylimidazolium chloride (EMIC) to be 2: 1 in molar ratio. The electrolyte solution which added lean monohydrate so that it may become a concentration of 0.5 g / L was prepared.

(Molten salt electrolysis)

In the above-mentioned electrolyte solution, molten salt electrolysis was performed so that a copper plate might be a cathode and the aluminum plate of 99.99% purity became an anode. Thereby, aluminum was electrodeposited on the surface of the copper plate, and the free aluminum plating film was obtained. The temperature of the electrolyte solution was 45 degreeC, and the current density was set to 3.0 A / dm <^2> .

<Substitution process>

(Replacement amount)

In the first electrolytic treatment step, FeCl ₄ was added to the electrolyte solution so as to be 20 mmol / L to prepare a substitution solution.

(Substitution condition)

The copper plate in which the free aluminum plating film was formed was immersed in the substitution liquid obtained above. The time to immerse was 10 second, and the temperature of the substitution liquid was 40 degreeC. Thereby, the substituted plating film in which the surface of the pre aluminum plating film was substituted by Fe was obtained.

<2nd electrolytic treatment process>

In the first electrolytic treatment step, a second electrolytic treatment step was performed in the same manner as the first electrolytic treatment step except that a copper plate with a substitution plating film was used instead of the copper plate.

Thereby, aluminum plating film No. 1 which has an intervening layer by Fe was obtained between the film surfaces of the both ends of the thickness direction. The film thickness of aluminum plating film No. 1 was about 15 micrometers.

Example 2

In Example 1, it carried out similarly to Example 1 except having added the process of removing the copper plate which is a base material, after immersing the obtained aluminum plating film No. 2 in nitric acid after a 2nd electrolytic treatment process. 2 was obtained. The film thickness of obtained aluminum plating film No. 2 was about 17 micrometers.

Example 3

<1st electrolytic treatment process>

(materials)

As a base material, the resin molded object which carried out the electroconductive process was prepared.

As the resin molded body, a polyurethane sheet (50 mm x 80 mm) having a skeleton having a three-dimensional network structure was used at a thickness of 1.0 mm. The porosity of the resin molded body was 96%, and the average pore diameter was 450 micrometers.

The conducting treatment was performed by immersing the polyurethane sheet in a carbon suspension to dry it, and forming a conductive layer on the surface of the skeleton of the polyurethane sheet. The components of the carbon suspension contained 25% of graphite and carbon black, and included a resin binder, a penetrant and an antifoaming agent. The particle diameter of carbon black was 0.5 micrometer.

(Electrolyte amount)

As electrolyte solution, the thing similar to the electrolyte solution used in the 1st electrolytic treatment process of Example 1 was prepared.

(Molten salt electrolysis)

In the electrolytic solution obtained above, molten salt electrolysis was carried out so that the polyurethane sheet subjected to the conducting treatment was a cathode and an aluminum plate having a purity of 99.99% became an anode. Thereby, aluminum was electrodeposited on the surface of the electrically conductive polyurethane sheet, and the free aluminum plating film was obtained. The temperature of the electrolyte solution was 45 degreeC, and the current density was set to 6.0 A / dm <^2> .

<Substitution process>

The substitution process was performed under the same conditions as in Example 1. As a result, a substituted plating film was formed on the surface of the skeleton of the polyurethane sheet.

<2nd electrolytic treatment process>

In the first electrolytic treatment step, a second electrolytic treatment step was performed in the same manner as in the first electrolytic treatment step except that a polyurethane sheet having a substituted plating film was used instead of the polyurethane sheet subjected to the conductive treatment.

Thereby, the aluminum plating film which has an intervening layer by Fe was obtained between the film surfaces of both ends of the thickness direction.

<Removal process>

The polyurethane sheet was burned and removed by heating the aluminum plating film obtained above to 600 degreeC in air | atmosphere.

This obtained aluminum plating film No. 3 which forms the frame | skeleton of the porous metal body which has a frame | skeleton of a three-dimensional network structure. The film thickness of aluminum plating film No. 3 was about 15 micrometers.

Example 4

In Example 3, aluminum plating film No. 4 was obtained like Example 3 except having used the following substitution liquid. The film thickness of aluminum plating film No. 4 was about 18 micrometers.

(Replacement amount)

To the electrolyte solution used in the first electrolytic treatment step of Example 1, ZnCl ₂ was added so as to be 40 mmol / L to prepare a replacement solution.

Example 5

In Example 3, aluminum plating film No. 5 was obtained like Example 3 except having used the following substitution liquid. The film thickness of aluminum plating film No. 5 was about 16 micrometers.

(Replacement amount)

ZrCl ₄ was added to 100 mmol / L in the electrolyte solution used in the first electrolytic treatment step of Example 1 to prepare a replacement solution.

Comparative Example 1

In Example 2, aluminum plating film No. 6 was obtained like Example 2 except having performed the 2nd electrolytic treatment process without performing a substitution process. The film thickness of aluminum plating film No. 6 was about 16 micrometers.

Comparative Example 2

In Example 3, aluminum plating film No. 7 was obtained like Example 3 except having performed the 2nd electrolytic treatment process without performing a substitution process. The film thickness of aluminum plating film No. 7 was about 18 micrometers.

-evaluation-

The following evaluation was performed about the aluminum plating film Nos. 1-7 which were obtained above. The evaluation results are shown in Table 1.

<Measurement of conductivity>

The resistivity of aluminum plating film No.2-No.7 was measured so that it might be 60 mm between measurement terminals using a resistivity meter.

The results are shown in Table 1.

As shown in Table 1, when the aluminum plating film No. 2 of Example 2 obtained by the method of forming on the surface of a copper plate is compared with the aluminum plating film No. 6 of the comparative example 1, it is the side of aluminum plating film No. 2 This low resistivity was obtained. In addition, the resistivity of the aluminum film having a thickness of 18 μm produced by rolling was 0.031 μΩ · m, and it was confirmed that the aluminum film No. 2 of Example 2 had the same low resistivity as the rolled film.

When the aluminum plating films No. 3 to No. 5 of Examples 3 to 5 obtained by the method of forming on the surface of the skeleton of the polyurethane sheet are compared with the aluminum plating film No. 7 of Comparative Example 2, aluminum plating The films No. 3 to No. 5 had a low resistivity.

<Surface Crossing of Aluminum Plating Film>

The cross sections of aluminum plating films No. 3, No. 4, and No. 7 were observed with a scanning electron microscope (SEM). The results are shown in FIGS. 7 to 9.

As shown to FIG. 7 and FIG. 8, the aluminum plating film No. 3, No. 4 which concerns on embodiment of this indication had intervening layers 72 and 82 between film surfaces of the both ends of a thickness direction. . The aluminum layers on both sides of the intervening layer were in close contact with each other without gaps.

On the other hand, aluminum plating film No. 7 of the comparative example 2 which did not perform the substitution process of the aluminum plating film formed by the 1st electrolytic treatment process and the aluminum plating film formed by the 2nd electrolytic treatment process as shown in FIG. The gap was formed in between, and adhesiveness was bad. In addition, a part of the aluminum plating film formed by the 2nd electrolytic treatment process was peeled off.

10: aluminum plating film
11: film surface
11 ': film surface
12: intervening layer
20: aluminum plating film
21: film surface
21 ': film surface
22: intervening layer
30: aluminum plating film
31: film surface
31 ': film surface
32: intervening layer
33: skeleton
34: inside of the skeleton
35: pore
65: pore
66: resin molded body
67: conductive layer
71: film surface
71 ': film surface
72: intervening layer
81: film surface
81 ': encapsulation
82: intervening layer

Claims (10)

As an aluminum plating film containing aluminum as a main component,
The said aluminum plating film contains the intervening layer containing the metal whose ionization tendency is smaller than aluminum, or the alloy of aluminum and the metal whose ionization tendency is smaller than aluminum between the coating surfaces of the both ends of the thickness direction. Having a layer,
Aluminum plating film. The method of claim 1,
The aluminum plating film is an elongated sheet shape. The method of claim 1,
The aluminum plating film | membrane which forms the said frame | skeleton of the metal porous body which has a frame | skeleton of a three-dimensional network structure. The method of claim 3,
The metal porous body is an aluminum plated film having a long sheet shape. The method according to any one of claims 1 to 4,
The aluminum plating film which has a some said intervening layer in the thickness direction of the said aluminum plating film. The method according to any one of claims 1 to 5,
The aluminum plating film whose said ionization tendency is smaller than aluminum is any 1 or more types chosen from the group which consists of iron, zinc, zirconium, manganese, nickel, and copper. The method according to any one of claims 1 to 6,
The aluminum plating film is 10 micrometers or more and 1000 micrometers or less in thickness of the said aluminum plating film. As a method of manufacturing the aluminum plating film according to claim 1,
A first electrolytic treatment step of electrodepositing aluminum on the surface of the substrate by electrolytically treating a substrate having at least a conductive surface in a first electrolyte solution, and forming a pre-aluminum plating film;
After the first electrolytic treatment step, the prealuminum plating film is immersed in a substitution liquid containing a metal having an ionization tendency smaller than aluminum and the first electrolyte solution, and the surface of the prealuminum plating film is made of a metal having an ionization tendency smaller than aluminum. A substitution step of substitution to form a substitution plating film,
After the substitution step, a second electrolytic treatment step of forming an aluminum plating film by electrodepositing aluminum on the surface of the substitution plating film by electrolytically treating the substitution plating film in a second electrolyte solution.
With
The first electrolyte solution and the second electrolyte solution is a molten salt containing at least aluminum chloride,
Manufacturing method of aluminum plating film. The method of claim 8,
The said base material is a manufacturing method of the aluminum plating film which is a resin molding which has frame | skeleton of a three-dimensional network structure. The method according to claim 8 or 9,
The manufacturing method of the aluminum plating film which has a removal process which removes the said base material after a said 2nd electrolytic treatment process.

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