JP2015140440A - Aluminum plating liquid, aluminum film, resin structure, aluminum porous body, and manufacturing method of the aluminum porous body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum plating liquid having large current density region capable of aluminum plating and small liquid resistance.SOLUTION: There is provided an aluminum plating liquid containing an aluminum halide, one or more kinds selected from a group consisting of alkyl imidazolium halide, alkyl pyridinium halide and a urea compound and an ammonium salt represented by following general formula (1) and having concentration of the ammonium salt of 1 g/L to 45 g/L. NR.X... general formula (1), where R represents a hydrogen atom or an alkyl group which may have a side chain and having 15 or less carbon atoms, X represents a halogen atom and R may be same or different from each other.

Description

  The present invention relates to an aluminum plating solution, an aluminum film, a resin structure, an aluminum porous body, and a method for producing the aluminum porous body.

  Metal porous bodies having a three-dimensional network structure are used in various fields such as various filters, catalyst carriers, and battery electrodes. For example, Celmet (manufactured by Sumitomo Electric Industries, Ltd .: registered trademark) made of a porous nickel body having a three-dimensional network structure (hereinafter referred to as “nickel porous body”) is an electrode material for batteries such as nickel metal hydride batteries and nickel cadmium batteries. It is used as Celmet is a metal porous body having continuous air holes, and has a feature of high porosity (90% or more) compared to other porous bodies such as a metal nonwoven fabric.

  Such a nickel porous body can be obtained by forming a nickel layer on the surface of a resin molded body having continuous ventilation holes such as foamed urethane, then heat-treating it to decompose the foamed resin molded body, and further reducing the nickel. It is done. The formation of the nickel layer is performed by depositing nickel by electroplating after applying carbon powder or the like to the surface of the skeleton of the foamed resin molded body and conducting a conductive treatment.

In addition to nickel, aluminum also has excellent characteristics such as conductivity, corrosion resistance, and light weight. In battery applications, for example, a positive electrode of a lithium ion battery is coated with an active material such as lithium cobalt oxide on the surface of an aluminum foil. Is used.
In order to improve the capacity of the positive electrode using aluminum, an aluminum porous body having a three-dimensional network structure with a large aluminum surface area (hereinafter referred to as “aluminum porous body”) is used. It is also conceivable to fill the active material. This is because by using the porous aluminum body, the active material can be retained even when the electrode is thickened, and the active material utilization rate per unit area is improved.

  As a method for producing the aluminum porous body, there is a method in which a foamed resin molded body having a three-dimensional network structure is subjected to aluminum plating. JP 2012-007233 A (Patent Document 1) is obtained by this plating method. The invention about the capacitor which uses the aluminum porous body made as an electrode is described. According to the method described in Patent Document 1, it is possible to uniformly plate high-purity aluminum on a porous resin molded body having a three-dimensional network structure, and to produce a high-quality aluminum porous body Can do.

JP 2012-007233 A

In the aluminum plating method using molten salt, an organic chloride salt such as 1-ethyl-3-methylimidazolium chloride (EMIC) or 1-butylpyridinium chloride (BPC) is mixed with aluminum chloride (AlCl ₃ ). By using the aluminum plating bath, aluminum can be electroplated onto the porous resin body at room temperature. In particular, the AlCl ₃ -EMIC system has good liquid properties and is useful as an aluminum plating solution.

In the aluminum plating solution using EMIC and AlCl ₃ described above, it is known that the higher the concentration of AlCl ₃ , the wider the current density range that can be plated (Tetsuko Takahashi, three others, “ Electroaluminum plating ", Nisshin Steel Technical Report, 1990, 63, p.44-51). Then, AlCl ₃ because it does not dissolve more than 67 mol%, aluminum plating solution 67mol% AlCl ₃ -33mol% EMIC containing the largest number of AlCl ₃ is the best in terms of plating efficiency. On the other hand, it is known that the conductivity of an ionic liquid obtained by mixing AlCl ₃ and EMIC increases as the concentration of EMIC increases.

  If the conductivity of the plating solution is low, the solution resistance increases, the voltage required to pass the same current increases, and the power cost increases. Further, since the liquid temperature rises due to Joule heat as the voltage rises, equipment for cooling the plating liquid is required to make the plating conditions constant, and the power cost further increases. For this reason, when a plating solution with high productivity capable of plating at a high current density is used, the power cost is generally increased.

  In view of the above problems, an object of the present invention is to provide an aluminum plating solution having a large current density range in which aluminum plating is possible and a small liquid resistance.

The present invention adopts the following configuration in order to solve the above problems.
That is, the aluminum porous body of the present invention is represented by the following general formula (1), one or more selected from the group consisting of aluminum halides, alkylimidazolium halides, alkylpyridinium halides, and urea compounds. An aluminum plating solution having a concentration of 1 g / L or more and 45 g / L or less.
NR ₄ ⁺ · X ^- ··· general formula (1)
However, in the general formula (1), R represents a hydrogen atom or an alkyl group having 15 or less carbon atoms which may have a side chain, X represents a halogen atom, and the Rs may be the same or different. It may be.

  According to the present invention, it is possible to provide an aluminum plating solution having a large current density range in which aluminum plating is possible and low liquid resistance.

First, the contents of the embodiment of the present invention will be listed and described.
(1) An aluminum plating solution according to an embodiment of the present invention includes one or more selected from the group consisting of an aluminum halide, an alkylimidazolium halide, an alkylpyridinium halide, and a urea compound, and the following general formula ( 1) and an aluminum plating solution having a concentration of the ammonium salt of 1 g / L or more and 45 g / L or less.
NR ₄ ⁺ · X ^- ··· general formula (1)
However, in the general formula (1), R represents a hydrogen atom or an alkyl group having 15 or less carbon atoms which may have a side chain, X represents a halogen atom, and the Rs may be the same or different. It may be.
The aluminum plating solution described in the above (1) is an aluminum plating solution having a large current density range that can be plated and a small liquid resistance. For this reason, it becomes possible to perform aluminum plating cheaply and efficiently by using the said aluminum plating solution.

(2) In the aluminum plating solution according to the embodiment of the present invention, the ammonium salt is dimethylamine hydrochloride or tetramethylamine hydrochloride, or the dimethylamine hydrochloride and the tetramethylamine hydrochloride. It is an aluminum plating solution as described in said (1) which is a mixture.
The aluminum plating solution described in the above (2) is a plating solution having a smaller liquid resistance, and can reduce the power cost required for forming the aluminum plating film.

(3) Further, in the aluminum plating solution according to the embodiment of the present invention, in the above (1) or (2), the alkyl imidazolium halide is 1-ethyl-3-methylimidazolium chloride (EMIC). The aluminum plating solution described.
With the aluminum plating solution described in (3) above, it is possible to increase the current density in the plating bath and to efficiently obtain a high-quality aluminum film at a higher speed.

(4) An aluminum film according to an embodiment of the present invention is an aluminum film obtained using the aluminum plating solution according to any one of (1) to (3) above.
The aluminum film described in the above (4) is an aluminum film obtained at high speed and efficiently at low cost because the aluminum plating solution described in any one of (1) to (3) is used.

(5) The resin structure according to the embodiment of the present invention is formed on the surface of the skeleton of a resin molded body having a conductive three-dimensional network structure, according to any one of (1) to (3) above. It is the resin structure which has the aluminum film obtained using the aluminum plating solution of description.
An aluminum porous body can be produced by removing the resin from the resin structure described in (5) above. Moreover, since the aluminum film formed on the surface of the skeleton of the resin structure is manufactured with high efficiency and at low cost, a porous aluminum body can be manufactured with high efficiency and at low cost by using the resin structure. can do.

(6) The porous aluminum body according to the embodiment of the present invention is an aluminum porous body obtained by removing a resin from the resin structure according to the above (5).
The aluminum porous body described in the above (6) is an aluminum porous body that can be produced efficiently and inexpensively.

(7) A method for producing a porous aluminum body according to an embodiment of the present invention includes a step of conducting a conductive treatment on the surface of a skeleton of a resin molded body having a three-dimensional network structure, and from (1) to (3) above. Using the aluminum plating solution according to any one of the above, a step of forming a resin structure by electrodepositing an aluminum film on the surface of the skeleton of the resin molded body subjected to the conductive treatment; and a resin from the resin structure And a step of removing the porous aluminum body.
By the method for producing an aluminum porous body described in (7) above, an aluminum porous body having a three-dimensional network structure can be produced efficiently and inexpensively.

[Details of the embodiment of the present invention]
Specific examples of the aluminum plating solution and the like according to the embodiment of the present invention will be described below. In addition, this invention is not limited to these illustrations, is shown by description of a claim, and it is intended that all the changes within the meaning and range equivalent to a claim are included. .

<Aluminum plating solution>
An aluminum plating solution according to an embodiment of the present invention includes at least one selected from the group consisting of alkylimidazolium halides, alkylpyridinium halides, and urea compounds, and an ammonium salt represented by the following general formula (1). And an aluminum plating solution having a concentration of the ammonium salt of 1 g / L or more and 45 g / L or less.
NR ₄ ⁺ · X ^- ··· general formula (1)
However, in the general formula (1), R represents a hydrogen atom or an alkyl group having 15 or less carbon atoms which may have a side chain, X represents a halogen atom, and the Rs may be the same or different. It may be.
The aluminum plating solution may contain other components as long as the quality of the aluminum film obtained using the plating solution is not impaired. Specifically, for example, an organic compound such as xylene, benzene, toluene, 1,10-phenanthroline may be included.

  The aluminum plating solution has high conductivity, and even when plating is performed at a high current density, it is possible to perform aluminum plating at a low voltage. It is possible to suppress the electric power applied to. Moreover, it becomes possible to plate aluminum at high speed. Furthermore, by using the aluminum plating solution, an aluminum plating film with a uniform thickness can be formed even when using a substrate with a very complicated shape, such as a resin molding having a three-dimensional network structure. can do.

The ammonium salt includes ammonium (NH ₄ ⁺ ), primary ammonium (NRH ₃ ⁺ ), secondary ammonium (NRH ₂ ⁺ ), tertiary ammonium ( NR ₂ H ⁺ ) and quaternary ammonium (NR ₄ ⁺ ) are general terms for chlorides of one or more ions selected from halogen ions. These ammonium salts, that is, in the above general formula (1), R represents a hydrogen atom or an alkyl group having 15 or less carbon atoms which may have a side chain. Among the alkyl groups having 15 or less carbon atoms, a methyl group, an ethyl group, an octyl group, and the like are preferable. These ammonium halogen salts having an alkyl group are preferred because they have a high effect of improving the conductivity of the aluminum plating solution.
Further, X in the general formula (1) is not particularly limited as long as it is a halogen atom, but chlorine (Cl), bromine (Br), and iodine (I) are preferable from the viewpoint of the stability of the plating solution.

  The ammonium salt is preferably dimethylamine hydrochloride or tetramethylamine hydrochloride, or a mixture of the dimethylamine hydrochloride and the tetramethylamine hydrochloride. These ammonium salts are preferable because they are highly effective in improving the conductivity of the aluminum plating solution and are easily available.

The concentration of the ammonium salt in the aluminum plating solution is 1 g / L or more and 45 g / L or less. When the concentration of the ammonium salt is less than 1 g / L, the conductivity of the aluminum plating solution cannot be sufficiently improved. Further, when the concentration of the ammonium salt is more than 45 g / L, the conductivity of the aluminum plating solution is improved. However, when an aluminum plating film is produced using the aluminum plating solution, the ammonium salt is added to the aluminum plating film. Entrainment occurs and a high-purity aluminum plating film cannot be obtained.
From these viewpoints, the concentration of the ammonium salt in the aluminum plating solution is more preferably 10 g / L or more and 36 g / L or less, and further preferably 15 g / L or more and 27 g / L or less.

Examples of the aluminum halide contained in the aluminum plating solution include aluminum chloride (AlCl ₃ ), aluminum bromide (AlBr ₃ ), and aluminum iodide (AlI ₃ ).
The alkyl imidazolium halide contained in the aluminum plating solution preferably has an alkyl group having 1 to 5 carbon atoms. Specific examples include 1-ethyl-3-methyl-imidazolium chloride (EMIC), 1-butyl-3-methyl-imidazolium chloride (BMIC), and the like.
The alkyl pyridinium halide contained in the aluminum plating solution preferably has an alkyl group having 1 to 5 carbon atoms. Specific examples include butylpyridinium chloride (BPC) and methylpyridinium chloride (MPC).
Among these, an ionic liquid obtained by mixing aluminum chloride with 1-ethyl-3-methyl-imidazolium chloride is preferable because of good liquid properties.
The mixing ratio of the aluminum halide and the alkyl imidazolium halide, alkyl pyridinium halide, or the alkyl imidazolium halide and alkyl pyridinium halide is 1: 1 or more and 3: 1 or less. Preferably, it is more preferably 3: 2 or more and 2: 1 or less.

但し、一般式（２）においてＲは、水素原子、炭素原子数が１個〜６個のアルキル基、又はフェニル基であり、互いに同一であっても、異なっていてもよい。
前記尿素化合物は上記の中でも、尿素、ジメチル尿素を特に好ましく用いることができる。 The aluminum plating solution can also be obtained by mixing the aluminum halide and a urea compound. The alkyl imidazolium halide and the alkyl pyridinium halide are relatively expensive organic chlorides. However, since the urea compound is inexpensive and easily available, the aluminum plating solution can be easily produced.
The urea compound means urea and its derivatives, and may be any substance that forms a liquid when mixed with aluminum chloride. For example, a compound represented by the following general formula (2) can be preferably used.

However, in General formula (2), R is a hydrogen atom, a C1-C6 alkyl group, or a phenyl group, and may mutually be same or different.
Among the above urea compounds, urea and dimethylurea can be particularly preferably used.

  A room temperature ionic liquid can be formed by mixing the urea compound with an aluminum halide. The urea compound is less expensive and easily available than the alkyl imidazolium halide and the alkyl pyridinium halide. For this reason, an aluminum plating solution can be manufactured at low cost.

  The mixing ratio of the urea compound and the aluminum chloride is preferably a molar ratio of urea compound: aluminum chloride = 1: 1.10 to 1: 1.50. When the mixing ratio of aluminum chloride is 1.10 or more, the viscosity of the formed ionic liquid can be within a suitable range, and plating can be efficiently performed with a sufficient current density. Further, when the mixing ratio of aluminum chloride is 1.50 or less, it is possible to suppress the mixing of impurities such as chloride into the aluminum film formed on the resin surface, and to obtain a high-quality aluminum film. Further, considering the plating efficiency, it is preferable that the amount of aluminum chloride is large. However, since aluminum chloride is highly corrosive, it is not preferable to use too much.

The mixing ratio of the urea compound and aluminum chloride is more preferably a molar ratio of urea compound: aluminum chloride = 1: 1.10 to 1: 1.20, and 1: 1.13 to 1: 1.17. Most preferably.
It was also found that the electrical resistance of the plating bath is significantly reduced when the mixing ratio of aluminum chloride is 1.13 to 1.17, particularly 1.15. By making the mixing ratio of aluminum chloride within this range, the voltage required for electrodeposition of aluminum can be lowered, which can contribute to energy saving and cost reduction, which is preferable. Further, since the temperature rise of the plating solution during operation is reduced, it is advantageous when the solution temperature is kept constant.

<Aluminum film>
The aluminum film according to the embodiment of the present invention is formed on the surface of the conductive substrate by causing aluminum to act as an anode and the conductive substrate as a cathode in the aluminum plating solution according to the embodiment of the present invention. Is obtained by electrodeposition. As described above, the aluminum plating solution is excellent in electrical conductivity, and is a plating solution with little increase in liquid temperature during operation. Therefore, the aluminum film can be obtained with high efficiency and at low cost.

<Resin structure>
In the resin structure according to the embodiment of the present invention, in the aluminum plating solution, a resin molded body having a three-dimensional network structure in which aluminum is an anode and a conductive treatment is used as a cathode. It is obtained by electrodepositing aluminum on the surface.
Hereinafter, the resin molded body and a method for conducting the resin molded body will be described in detail.

  Any resin can be selected as the material of the resin molded body. For example, a foamed resin molded article produced using polyurethane, melamine or the like can be exemplified as the material. 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 such as polypropylene and polyethylene can be used in place of the foamed resin molding.

  The resin molded body preferably has a porosity of 80% to 98% and a pore diameter of 50 μm to 500 μm. Urethane foam and foamed melamine can be preferably used as the resin molded article because they have high porosity, have pore connectivity and are excellent in thermal decomposability. Foamed urethane is preferable in terms of the uniformity of pores and availability, and is preferable in that a product having a small pore diameter can be obtained. In addition, since foamed resin moldings such as foamed urethane and foamed melamine often have residues such as foaming agents and unreacted monomers in the foaming process, it is preferable to perform a washing treatment.

The porosity of the molded resin is defined by the following equation.
Porosity = (1− (weight of porous material [g] / (volume of porous material [cm ³ ] × material density))) × 100 [%]
The pore diameter is an average of the average pore diameter = 25.4 mm / cell count by enlarging the surface of the resin molded body with a micrograph and counting the number of pores per inch (25.4 mm) as the number of cells. Find the value.

The conductive treatment of the resin surface can be selected including known methods. A method of forming a metal layer such as nickel by electroless plating or a vapor phase method, or forming a metal or carbon layer by a conductive paint can be used.
By forming a metal layer on the resin surface by electroless plating or a vapor phase method, the conductivity of the resin surface can be increased. On the other hand, although it is somewhat inferior from the viewpoint of electrical conductivity, the conductive surface of the resin surface by carbon coating can be made without mixing any metal other than aluminum into the aluminum structure after plating. A structure can be manufactured. There is also an advantage that it can be made conductive at low cost.

The conductive treatment can be performed by applying a carbon paint on the surface of the skeleton of the resin molded body. The suspension as the carbon coating used in this case preferably contains a binder, a dispersant and a dispersion medium in addition to the carbon particles.
In order to uniformly apply the carbon particles on the surface of the skeleton of the resin molded body, the suspension needs to maintain a uniform suspension state. For this purpose, the suspension is preferably maintained at 20 ° C to 40 ° C. By maintaining the temperature of the suspension at 20 ° C. or higher, a uniform suspension state can be maintained, and only the binder is concentrated on the surface of the skeleton forming the network structure of the resin molded body to form a layer. The carbon particles can be uniformly applied. Since the layer of carbon particles uniformly applied in this manner is difficult to peel off, it is possible to form a strongly adhered aluminum plating. On the other hand, when the temperature of the suspension is 40 ° C. or lower, the evaporation of the dispersant can be suppressed, so that it is possible to suppress the suspension from becoming difficult to concentrate with the lapse of the coating treatment time.
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 molded body or inhibits smooth plating, and if it is too small, it is difficult to ensure sufficient conductivity.

<Porous aluminum body>
The aluminum porous body according to the embodiment of the present invention is an aluminum porous body obtained by removing a resin from the resin structure according to the above-described embodiment of the present invention. The aluminum porous body has a three-dimensional network structure, and can exhibit excellent characteristics for various filters, catalyst carriers, battery electrodes, and the like.
The method for removing the resin from the resin structure is not particularly limited. For example, the resin structure is subjected to a heat treatment in which the resin is decomposed at 370 ° C. or higher, preferably 500 ° C. or higher, in which the resin is decomposed in a nitrogen atmosphere or in the air, whereby the resin is burned down to obtain an aluminum porous body. it can.

<Method for producing porous aluminum>
A method for producing a porous aluminum body according to an embodiment of the present invention uses a step of conducting a conductive treatment on the surface of a skeleton of a resin molded body having a three-dimensional network structure, and an aluminum plating solution according to the embodiment of the present invention. Then, a step of forming a resin structure by electrodepositing an aluminum film on the surface of the skeleton of the resin molded body subjected to the conductive treatment and a step of removing the resin from the resin structure are included.
-Process of conducting resin molded body-
This step is a step for forming a conductive layer on the surface of the skeleton of the resin molded body having a three-dimensional network structure so that the resin molded body has conductivity. As the resin molded body having a three-dimensional network structure, those described above can be preferably used. The conductive treatment of the resin molded body may be performed as described above.
-Process of forming aluminum plating film-
In order to form an aluminum film on the surface of the skeleton of the resin molded body subjected to the conductive treatment, as described above, in the aluminum plating solution according to the embodiment of the present invention, the aluminum is an anode, and the three-dimensional network is subjected to the conductive treatment. What is necessary is just to make the resin molding which has a shape structure act as a cathode. Thereby, aluminum is electrodeposited on the surface of the skeleton of the resin molded body, and the resin structure can be obtained.
-Process of removing resin-
In order to remove the resin from the resin structure, heat treatment may be performed in a nitrogen atmosphere or in the air as described above.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, these Examples are illustrations, Comprising: The aluminum plating solution of this invention etc. are 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]
Aluminum chloride and 1-ethyl-3-methylimidazolium chloride (EMIC) were mixed at a molar ratio of 2: 1 to prepare ionic liquid 1. To this ionic liquid 1, methylammonium chloride, which is a primary ammonium salt, was further added to a concentration of 15 g / L to prepare an aluminum plating solution 1.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 1 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 1 was increased by 11%. The electrical conductivity was measured using the AC impedance method.

[Example 2]
Aluminum plating solution 2 was produced by adding dimethylamine hydrochloride, which is a secondary ammonium salt, to 27 g / L to ionic liquid 1 produced in Example 1.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 2 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 2 was increased by 20%.

[Example 3]
Trimethylammonium chloride, which is a tertiary ammonium salt, was further added to the ionic liquid 1 produced in Example 1 to a concentration of 21 g / L to produce an aluminum plating solution 3.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 3 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 3 was increased by 13%.

[Example 4]
A quaternary ammonium salt, tetraoctylammonium chloride, was further added to the ionic liquid 1 produced in Example 1 to a concentration of 18 g / L to produce an aluminum plating solution 4.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 4 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 4 was increased by 18%.

[Example 5]
An aluminum plating solution 5 was produced by adding ammonium chloride to the ionic liquid 1 produced in Example 1 so as to be 10 g / L.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 5 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 5 was increased by 5%.

[Example 6]
The ionic liquid 1 produced in Example 1 further has 10 g / L of tetramethylammonium chloride, which is a quaternary ammonium salt, so that dimethylamine hydrochloride, which is a secondary ammonium salt, is 15 g / L. In this manner, an aluminum plating solution 6 was prepared by adding each of them.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 6 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 6 was increased by 22%.

[Example 7]
Aluminum chloride and 1-butylpyridinium chloride (BPC) were mixed at a molar ratio of 2: 1 to prepare ionic liquid 2. Further, tetramethylammonium chloride, which is a quaternary ammonium salt, was added to the ionic liquid 2 so as to be 18 g / L, thereby preparing an aluminum plating solution 7.
When the electrical conductivity of the ionic liquid 2 and the aluminum plating solution 7 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 7 was increased by 15%.

[Example 8]
Aluminum chloride and urea were mixed at a molar ratio of 1.5: 1 to prepare ionic liquid 3. Dimethylamine hydrochloride, which is a secondary ammonium salt, was added to this ionic liquid 3 so as to be 27 g / L, thereby preparing an aluminum plating solution 8.
When the electrical conductivities of the ionic liquid 3 and the aluminum plating solution 8 were measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 8 was increased by 25%.

[Example 9]
Aluminum chloride, EMIC, BPC, and urea were mixed at a molar ratio of 2: 0.8: 0.1: 0.1 to prepare ionic liquid 4. Tetramethylammonium chloride, which is a quaternary ammonium salt, was added to this ionic liquid 4 at 15 g / L to prepare an aluminum plating solution 9.
When the electrical conductivity of the ionic liquid 4 and the aluminum plating solution 9 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 9 was increased by 18%.

[Example 10]
Aluminum plating solution 10 was prepared by adding dimethylamine hydrochloride, which is a secondary ammonium salt, to ionic liquid 1 prepared in Example 1 so as to be 1 g / L.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 10 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 10 was increased by 3%.

[Example 11]
Aluminum plating solution 11 was prepared by adding dimethylamine hydrochloride, which is a secondary ammonium salt, to ionic liquid 1 prepared in Example 1 so as to be 45 g / L.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution 11 was measured and compared, it was confirmed that the electrical conductivity of the aluminum plating solution 11 was increased by 15%.

[Example 12]
Using the aluminum plating solution 1 produced in Example 1, an aluminum porous body was produced as follows.
-Formation of conductive layer-
As a resin molded body having a three-dimensional network structure, urethane foam having a thickness of 1 mm, a porosity of 95%, and a pore number (cell number) of about 46 per inch was prepared and cut into 50 mm × 80 mm squares. The foamed urethane was immersed in a carbon suspension and dried to form a conductive layer having carbon particles attached to the entire surface of the foamed urethane. The components of the carbon suspension include graphite + carbon black 25% and include a resin binder, a penetrating agent, and an antifoaming agent. The particle size of carbon black was 0.5 μm.
-Molten salt plating-
Subsequently, using the aluminum plating solution 1 produced in Example 1, aluminum was electrodeposited on the surface of the skeleton of urethane foam subjected to the conductive treatment prepared above to obtain a resin structure. The plating conditions were a plating solution with a current density of 6.0 A / dm ² and stirring the plating solution. Stirring was performed with a stirrer using a Teflon (registered trademark) rotor. The current density is a value calculated from the apparent area of the urethane foam. The amount of the aluminum plating solution 1 was 0.5 L.
-Removal of resin-
The resin structure obtained above was taken out from the plating bath, washed with water, and then heat treated at 600 ° C. for 30 minutes in the atmosphere. As a result, the resin was burnt out, and an aluminum porous body (purity 99.9% by mass) was obtained.
(Evaluation)
In the step of electrodepositing aluminum on the surface of the skeleton of the resin molded body, that is, in the aluminum plating step, the temperature rise of the plating solution is about 10 ° C., and the temperature rise when plating with the ionic liquid 1 is increased Compared with being 30 ° C., it was confirmed that the burden of controlling the liquid temperature was reduced, and thereby the power cost could be suppressed. Moreover, the plating film was also formed uniformly.

[Comparative Example 1]
Aluminum plating solution A was prepared by adding dimethylamine hydrochloride, which is a secondary ammonium salt, to 0.5 g / L to ionic liquid 1 prepared in Example 1.
When the electrical conductivities of the ionic liquid 1 and the aluminum plating solution A were measured and compared, the rate of increase in the electrical conductivity of the aluminum plating solution A was almost as low as 0.2%.

[Comparative Example 2]
Aluminum plating solution B was prepared by adding dimethylamine hydrochloride, which is a secondary ammonium salt, to 47 g / L to ionic liquid 1 prepared in Example 1.
When the electrical conductivity of the ionic liquid 1 and the aluminum plating solution B was measured and compared, the electrical conductivity of the aluminum plating solution B was increased by 10%, but dimethylamine hydrochloride was involved in the plating film. The purity of the aluminum plating film was 99.8%, which was not preferable.

Claims (7)

Aluminum halide,
Any one or more selected from the group consisting of alkylimidazolium halides, alkylpyridinium halides, and urea compounds;
An ammonium salt represented by the following general formula (1);
Including
An aluminum plating solution having a concentration of the ammonium salt of 1 g / L or more and 45 g / L or less.
NR ₄ ⁺ · X ^- ··· general formula (1)
In the above general formula, R represents a hydrogen atom or an alkyl group having 15 or less carbon atoms which may have a side chain, X represents a halogen atom, and the Rs may be the same or different from each other. Good.   The aluminum plating solution according to claim 1, wherein the ammonium salt is dimethylamine hydrochloride or tetramethylamine hydrochloride, or a mixture of the dimethylamine hydrochloride and the tetramethylamine hydrochloride.   The aluminum plating solution according to claim 1 or 2, wherein the alkyl imidazolium halide is 1-ethyl-3-methylimidazolium chloride (EMIC).   An aluminum film obtained using the aluminum plating solution according to claim 1.   The resin structure which has the aluminum film obtained using the aluminum plating liquid of Claim 1 on the surface of the frame | skeleton of the resin molding which has a three-dimensional network structure which carried out the electroconductive process.   A porous aluminum body obtained by removing a resin from the resin structure according to claim 5. A step of conducting a conductive treatment on the surface of the skeleton of the resin molded body having a three-dimensional network structure;
Using the aluminum plating solution according to claim 1 to form a resin structure by electrodepositing an aluminum film on the surface of the skeleton of the resin-molded resin-molded body;
Removing the resin from the resin structure;
The manufacturing method of the aluminum porous body which has this.