JP2003193335A - Hollow-shaped material and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environmentally friendly method for producing a hollow- shaped material by which toxic gases such as carbon dioxide are not produced during production and a substance to be a template can be reutilized. <P>SOLUTION: This method for producing the hollow-shaped material comprises steps of using an amphoteric compound capable of forming a fibrous material, forming a covered fibrous material having a core material formed of the fibrous material and an exterior finishing material formed of a metal material or a metal oxide and dissolving the core material formed of the fibrous material. The toxic gases such as the carbon dioxide are not produced and the substance to be the template can be reutilized by the method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hollow shaped article, and more particularly to a method for producing a hollow shaped article in which harmful gas such as carbon dioxide is not generated during production. is there.

[0002]

2. Description of the Related Art Ultrafine metal fibers are widely used in electrode plates for fuel cells and secondary batteries, catalysts, catalyst carriers, electrodes for displays, electrodes for mobile phones and the like. Further, in particular, as a means for improving the performance of fuel cells, secondary batteries, etc., it is required to increase the surface area of the electrode material and improve the catalyst efficiency. In order to increase the surface area of the electrode material, there has been proposed a method for producing a hollow product by a casting method using a fibrous molecular assembly formed by a surfactant or a fiber spun with a polymer as a casting mold.

As a method for producing hollow metal fibers as described above, Shnur et al. Use a fibrous molecular assembly formed of amphipathic surfactant molecules as a template, and subject this template to electroless plating. Proposed is a method of producing a composite material composed of an organic molecule and a metal, sintering the obtained composite material, and removing the organic molecule by burning to produce a hollow metal fiber (Materials Science and Engineering,
A158 (1992) 1-6). Further, a method for producing a hollow metal fiber is known in addition to the above-mentioned documents, but a method generally practiced for producing a hollow metal fiber is, in principle, the one described in the above-mentioned document. It is the same. That is, after obtaining a composite material composed of organic molecules and a metal, the obtained composite material is sintered.

The above-mentioned method has a step of oxidatively burning the composite material, and energy for this combustion is required. In addition, there is a problem that a harmful gas containing carbon dioxide as a main component is generated due to the burning of the surfactant to cause a global warming phenomenon. In addition, the fibrous molecular aggregate formed by the surfactant is in equilibrium with molecular aggregates having different shapes such as circular micelles and vesicles, so the shape of the molecular aggregate depends on the temperature and additives. It is easily affected and limits the manufacturing conditions when manufacturing a composite material composed of organic molecules and a metal.

On the other hand, as a method of producing hollow metal fibers, a method of using spun polymer fibers having a chemically and physically stable shape as a fibrous organic template has been proposed (Journal of Power Sources, 50 (1994) 2
1-25). In the method described in the literature, fibers are obtained by spinning polypropylene, the obtained fibers are used as a mold, and the mold is coated with nickel by electroless plating,
A complex composed of an organic substance and a metal is obtained. The resulting composite is oxidatively burned to produce a nickel hollow fiber.

According to such a manufacturing method, when compared with the fibrous molecular aggregate formed by the surfactant,
Since polymer fibers having a chemically and physically stable shape are used as a template, there is an advantage that the range of manufacturing conditions in the step of coating the polymer fibers by electroless plating can be expanded. However, as the step of removing the polymer fiber as the template from the composite, since the combustion method is used as in the above-mentioned method, there is a problem that harmful gas such as carbon dioxide is generated. Further, since the mold is sintered to obtain hollow fibers, the mold burns and cannot be reused.

In the above-mentioned method, since it is necessary to remove the mold by combustion, energy for combustion is required, and a harmful gas such as carbon dioxide is generated when the mold is removed. Therefore, there is a strong demand for a method for producing a hollow-shaped product which can reuse a substance serving as a template without causing by-product of harmful gas such as carbon dioxide.

[0008]

Therefore, an object of the present invention is to prevent generation of harmful gas such as carbon dioxide during production.
An object of the present invention is to provide a method for producing an environmentally friendly hollow shape product capable of reusing a substance serving as a template.

[0009]

[Means for Solving the Problems] The present inventors have already reported that a specific amphoteric compound can be dissolved in an alkaline aqueous solution to form a fiber in the vicinity of neutrality (J. Am. Che.
m. Soc. 2000, 122, 10997-11004). The present inventors have found that the above problems can be solved by producing a hollow article using the amphoteric compound.

The present invention has been made on the basis of the above findings, and (A) an amphoteric compound capable of forming a fibrous substance is dissolved in water to prepare an amphoteric compound aqueous solution, and the amphoteric compound aqueous solution is used to form the fibrous compound. Forming a fibrous material to obtain a fibrous material-containing aqueous solution; (B) a core material formed of a fibrous material by coating the fibrous material in the fibrous material-containing aqueous solution with a metal material or a metal oxide. And (C) dissolving the core material formed of the fibrous material of the coated fibrous material, Provided is a method for producing a hollow shaped article, which comprises obtaining a hollow shaped article formed of a metal material or a metal oxide. With the above structure, a manufacturing method for obtaining an environmentally-friendly hollow shape product in which no harmful gas of carbon dioxide is generated during the manufacturing process is obtained.

In the invention described in claim 2, a compound having a carboxyl group and a pyridyl group is used as the amphoteric compound. In the invention described in claim 3, the compound represented by the general formula (I) is used as the amphoteric compound. By using the above compound in the method for producing a hollow shaped article of the present invention, the formation of a fibrous material is facilitated, and it is possible to easily coat the fibrous material with a metal material or a metal oxide. It is possible to obtain a hollow article without burning the core material formed of the fibrous article.

Further, in the invention according to the fourth aspect, the core material formed of the fibrous material is dissolved by changing the hydrogen ion concentration or temperature of the fibrous material-containing aqueous solution. With such a configuration, it is not necessary to burn the core material formed of the fibrous material, and the method for manufacturing the hollow shaped material is environmentally friendly. It can be dissolved without burning and is a production method that does not generate harmful gas such as carbon dioxide. Moreover, since the core material formed of the fibrous material can be dissolved without burning, the amphoteric compound capable of forming the fibrous material can be recovered and reused.

Further, in the invention described in claim 5, the fibrous material is formed by placing the amphoteric compound aqueous solution in a carbon dioxide atmosphere. Since the fibrous substance is formed by placing the amphoteric compound aqueous solution in a carbon dioxide atmosphere, a particularly complicated device is not required to carry out the method for producing a hollow shaped product of the present invention, and a simple device can be used. It is possible.

In the invention according to claim 6, the fibrous material is coated with a metal material by electroless plating. With such a configuration, the coating process is easy, and it is possible to easily form a coating having a uniform film thickness.

Further, in the invention according to claim 7, the obtained hollow shaped article is a hollow metal fiber. Since the obtained hollow metal fibers have a large surface area, they can be used for electrode plates of fuel cells and secondary batteries, catalysts, catalyst carriers, display electrodes, mobile phone electrodes, etc., and have such a wide range of applications. Hollow metal fibers can be produced by an environmentally friendly method that does not generate harmful gases such as carbon dioxide.

Further, in the invention described in claim 8, the amphoteric compound recovered from the core material dissolved in the step (C) is used as a material. With such a configuration, the amphoteric compound that is the substance used as the template can be reused, so that waste of resources can be eliminated.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a hollow article according to the present invention comprises: (A) dissolving an amphoteric compound capable of forming a fibrous substance in water to prepare an aqueous solution of the amphoteric compound, and preparing the fibrous compound from the aqueous solution of the amphoteric compound. Forming a fibrous material to obtain a fibrous material-containing aqueous solution; (B) a core material formed of a fibrous material by coating the fibrous material in the fibrous material-containing aqueous solution with a metal material or a metal oxide. And (C) dissolving the core material formed of the fibrous material of the coated fibrous material, It is characterized in that a hollow shaped article formed of a metal material or a metal oxide is obtained.

FIG. 1 is a diagram showing steps of the method for producing a hollow shaped article of the present invention. As shown in FIG. 1, the hollow shaped article manufacturing method of the present invention comprises (A) a fiber forming step, (B) a fiber coating step, (C) a core material removing step, and (D) an amphoteric compound collecting step. . Then, in the step (C), the core material formed of the fibrous material is melted to obtain a hollow shaped material. In this step (C), after the hollow-shaped product is recovered by filtration or the like, the amphoteric compound which is a constituent element of the dissolved fibrous material is dissolved in the aqueous solution.
The amphoteric compound can be recovered (step D) and reused.

First, the amphoteric compound capable of forming a fibrous material used in the present invention will be described. The amphoteric compound used in the present invention has an acidic group and a basic group, and an intermolecular hydrogen bond is formed between the acidic group and the basic group. It is preferable that the acidic group and the basic group each have a terminal of the molecule. In the above amphoteric compound having an acidic group and a basic group, an intermolecular hydrogen bond is formed between the acidic group in the molecule and the basic group of another molecule, and the amphoteric compound has a fibrous form and has a fibrous shape. Form a thing. Further, the amphoteric compound used in the present invention is one which is dissolved by changing the temperature of the aqueous solution or the hydrogen ion concentration.
By using the amphoteric compound having such a property, it is possible to recover the amphoteric compound because sintering is not required to remove the core material in the step (C).

The acidic group contained in the amphoteric compound used in the present invention is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, a phosphonic acid group, a phenolic hydroxyl group and a sulfinic acid group. Also,
The basic group is not particularly limited, and examples thereof include primary, secondary, and tertiary amino groups as the aliphatic basic group, and examples thereof include pyridyl group, picolyl group, and quinolyl group as the aromatic condensed ring basic group. , An imidazoyl group and a benzimidazoyl group.

As the amphoteric compound used in the present invention, those having a carboxyl group and a pyridyl group in the molecule are preferably used. The compound is not particularly limited as long as it can form a fibrous substance in an aqueous solution, and examples thereof include compounds represented by the following general formula.

[0022]

[Chemical 2]

(Wherein R is hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms,
m is an integer of 1 to 20, preferably 1 to 10. )

Further, as the amphoteric compound used in the present invention, those represented by the following general formula (I) are more preferably used.

[0025]

[Chemical 3] (In the formula, R is hydrogen or 1 to 10 carbon atoms, preferably 1
5 is a linear or branched alkyl group, and m is 1-2.
It is an integer of 0, preferably 1-10. )

In the present invention, the amphoteric compound having an aromatic ring as described above is preferably used, but the amphoteric compound used in the present invention is not limited to those having an aromatic ring. Any amphoteric compound that can form a fibrous material in an aqueous solution can be used without particular limitation. Further examples of the amphoteric compounds that can be used in the present invention include, for example, α-ω-amino acids, benzene derivatives substituted with an aminoalkyl group and a carboxyl group, naphthalene derivatives, anthracene derivatives, azobenzene derivatives, stilbenzene derivatives and biphenyl. Examples include derivatives.

The method for producing a hollow article according to the present invention comprises (A)
A step of dissolving an amphoteric compound capable of forming a fibrous substance in water to prepare an aqueous solution of the amphoteric compound and forming a fibrous substance from the aqueous solution of the amphoteric compound to obtain an aqueous solution containing the fibrous substance; (B) the fibrous substance A coated fibrous material having a core material formed of a fibrous material and an exterior material formed of a metal material or a metal oxide by coating the fibrous material in a containing aqueous solution with a metal material or a metal oxide. A step of forming; and (C) a hollow material formed of a metal material or a metal oxide is obtained by dissolving a core material formed of the fibrous material of the coated fibrous material.

The present invention is characterized in that the hollow material formed of a metal material is obtained by dissolving the core material formed of a fibrous material in the step (C), and the hollow metal fiber has been conventionally used. Unlike the method used to manufacture the core, it does not have a step of burning out the core material.
Therefore, the amphoteric compound forming the core material is not burned out, and a hollow-shaped product formed of the metal material is obtained only by melting, and the amphoteric compound forming the core material can be reused. is there. Further, the conventional method has a step of sintering, and cracks may occur in the obtained hollow metal fibers, and the quality may deteriorate, but in the method for producing a hollow shaped article of the present invention, sintering is performed. Since it does not have a step, the obtained hollow shaped article does not crack and a high quality hollow shaped article can be obtained.

Next, the method of manufacturing the hollow shaped article of the present invention will be described step by step. First, the step (A) will be described. In the step (A), an amphoteric compound capable of forming a fibrous substance is dissolved in water to prepare an amphoteric compound aqueous solution,
A step of forming a fibrous substance from the amphoteric compound aqueous solution to obtain a fibrous substance-containing aqueous solution. As the amphoteric compound, it is preferable to use a powdery one dissolved in water or an aqueous solution containing an aqueous organic solvent. As described above, the amphoteric compound can be reused in the method for producing a hollow shaped article of the present invention, and by using the powdered one, the amphoteric compound from the aqueous solution after the hollow shaped article is obtained. The recovery rate of is improved.

In the step (A), first, an amphoteric compound capable of forming a fibrous substance is dissolved in water to prepare an amphoteric compound aqueous solution. The compound represented by the general formula (I) will be described below as an example. The compound represented by the general formula (I) forms a fibrous substance in an aqueous solution having a pH of 2 to 11, and has a pH of more than 11. And soluble in aqueous solutions with a pH below 2.

Therefore, the amphoteric compound aqueous solution is prepared by dissolving the compound represented by the general formula (I) in an aqueous solution having a pH of more than 11 or less than 2. For example, the compound represented by the general formula (I) is dissolved in an aqueous sodium hydroxide solution. The concentration of the amphoteric compound in the prepared amphoteric compound aqueous solution is not particularly limited, but is preferably about 0.1 to 10% by mass. The concentration of the amphoteric compound is preferably determined in consideration of the shaft diameter, length, etc. of the fiber to be obtained. Further, the sodium hydroxide aqueous solution may have a concentration such that its pH exceeds 11.

Next, a fibrous substance is formed from the obtained amphoteric compound aqueous solution to obtain a fibrous substance-containing aqueous solution. Since the compound represented by the general formula (I) forms a fibrous material at a pH of 2 to 11, the p of the aqueous solution of the amphoteric compound is
By setting H to 2 to 11, a fibrous substance can be formed from the amphoteric compound aqueous solution. The method for adjusting the pH of the aqueous solution of the amphoteric compound to 2 to 11 is not particularly limited, but for example, it can be carried out by dropping an aqueous solution in which an acidic substance such as dilute hydrochloric acid is dissolved, or spraying carbon dioxide to the aqueous solution. It can also be implemented by When a fibrous substance is formed by blowing carbon dioxide to the amphoteric compound aqueous solution, the blowing amount of carbon dioxide is about 10 to 1000 ml / min, and the time may be about 3 hours.

By leaving the amphoteric compound aqueous solution in the air, carbon dioxide in the air is dissolved in the amphoteric compound aqueous solution, the aqueous solution is neutralized, and a fibrous material is formed.
By leaving the amphoteric compound aqueous solution in the air and gradually dissolving carbon dioxide in the air in the amphoteric compound aqueous solution,
The length of the fiber can be increased. To leave the aqueous amphoteric compound solution in the air to form a fibrous material, leave the aqueous amphoteric compound solution in the air for about 7 days.

The axial diameter and the length of the obtained fibrous material are determined by the conditions for forming the fibrous material, that is, the concentration of the amphoteric compound,
It can be changed by the pH, the time for which the fibrous material is left in the air, and the like. The fibrous material contained in the fibrous material-containing aqueous solution obtained by the step (A) in the method for producing a hollow shaped article of the present invention has a shaft diameter of 0.1 μm or more for the production reason including the filtration step. And the length is preferably 10 μm or more.

Next, the step (B) will be described. In the step (B), a fibrous material contained in the fibrous material-containing aqueous solution obtained in the step (A) is coated with a metal material or a metal oxide to form a core material formed of the fibrous material. It is a step of forming a coated fibrous material having an exterior material formed of a metal material or a metal oxide.

The coating of the metal material in the step (B) will be described. As a method for coating the above fibrous material with a metal material, a conventionally known method can be used without any limitation. If the fibrous material can be coated with a metal material,
Although any method may be used, electroless plating is preferably used in the present invention. An electroless plating film is formed on a fibrous material by an electroless plating method, the fibrous material is coated with a metal material, and a coating having a core material formed of the fibrous material and an exterior material formed of the metal material is formed. A fibrous material is formed.

The electroless plating method can be carried out by a conventionally known method. Hereinafter, the coating of the fibrous material with the metal material by the electroless plating method will be briefly described. The electroless plating method is divided into a catalyst application step and an electroless plating step. The case of coating nickel will be described below. The step of imparting a catalyst is performed by catalyzing with a solution containing palladium chloride. The catalyst application step is a step performed to achieve uniform plating film thickness.

The electroless plating step is generally a step of reducing nickel with a reducing agent in an aqueous solution containing nickel salts such as nickel phosphate, nickel hypophosphite, nickel nitrate, nickel chloride and nickel sulfate. Therefore, it is preferable that a complexing agent, a pH adjusting agent, a buffering agent, a stabilizing agent, or the like is contained in the aqueous solution, if necessary. The electroless plating method of autocatalytically reducing nickel ions using an aqueous solution containing nickel hypophosphite is more preferable.

The plating bath used in the electroless plating process has a nickel salt concentration of 0.1 to 20.
It is preferable to use a plating bath having a mass%, and it is more preferable to use a plating bath having a nickel salt concentration of 1 to 10 mass%. Further, the coating of the fibrous material with the metal material by the electroless plating in the step (B) of the present invention is preferably performed in two steps, and a plating bath having a low nickel salt concentration is used in the first step. It is more preferable to use a plating bath having a high nickel salt concentration in the second step. It is preferable to perform the electroless plating in the two-step process because the electroless plating in the two-step process using the plating baths having different nickel concentrations makes the plating film thickness more uniform.

The pH of the plating bath for carrying out the above nickel electroless plating step is preferably 4.5 to 7, and more preferably 5 to 6. When the pH of the plating bath is less than 5, the plating rate may be slow, and the pH is 6
If it exceeds the range, the plating rate may be too fast, and in either case, it may be impossible to form a uniform plating film thickness. Therefore, the pH of the plating bath is preferably within the above range.

In the step (B) in the method for producing a hollow article according to the present invention, as described above, the fibrous material in the aqueous solution containing the fibrous material obtained in the step (A) is coated with a metal material. A coated fibrous material having a core material formed of the fibrous material and an exterior material formed of a metal material is formed. In the step (B), the fibrous material is coated with a metal material to form an exterior material with the metal material. The thickness of the exterior material is usually 0.5 to 30 μm.

In the above description, the case where the fibrous material is plated with nickel has been described. However, a metal material other than nickel can be used in the present invention. Examples of such a metal material include Although silver, copper, gold, palladium, lead, platinum, nickel alloy, tin, rhodium, cadmium, ruthenium, indium, cobalt and the like can be used, the metal material used in the present invention is not limited to the above. Any fibrous material that can be coated by plating can be used.

Next, the coating of the metal oxide in the step (B) will be described. As a method of coating the fibrous material with a metal oxide, a conventionally known method can be used without any limitation. Any method may be used as long as it can coat the fibrous material with a metal material. Examples of the method of coating the fibrous material with the metal oxide include the following methods. For example, the fibrous material is mixed in an aqueous solution containing tetraethoxysilane, an acidic substance such as dilute hydrochloric acid is added to accelerate the hydrolysis and condensation reaction of tetraethoxysilane, and the fibrous material is used as a core material. A metal oxide-coated fibrous material having a silicon polymer as an exterior material can be formed.

Examples of the metal oxide used in the present invention include oxides of silicon, titanium, tin, alumina, germanium, lead and the like, but the metal oxide used in the present invention is limited to the above. However, all that can coat the fibrous material can be used.

Next, the step (C) will be described. The step (C) is a fibrous material of a coated fibrous material obtained by the step (B), which has a core material formed of a fibrous material and an exterior material formed of a metal material or a metal oxide. In this step, the hollow material formed of a metal material or a metal oxide is obtained by melting the core material formed in (1).

The method of dissolving the core material formed of the fibrous material is not particularly limited, but for example, the compound represented by the general formula (I) forms a fibrous material at a pH of 2 to 11, and The core material can be dissolved by immersing the above coated fibrous material in a solution having a pH of less than 2 or a pH of more than 11, since the core material dissolves at a pH of less than 1 and a pH of more than 11.

When the coated fibrous material is dipped in a solution having a pH of more than 11, the solution used is, for example, an aqueous solution containing sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, or ammonia water. Also,
Examples of the solution used when the pH is less than 2 include diluted hydrochloric acid, diluted sulfuric acid, diluted nitric acid aqueous solution, and an aqueous solution containing halogenated acetic acid such as chloroacetic acid, dichloroacetic acid and trichloroacetic acid.

For example, when the compound represented by the above general formula (I) is used as the amphoteric compound, the core material of the coated fibrous substance is dissolved by immersing it in a sodium hydroxide solution having a pH of 14 for about 5 minutes to 24 hours. Therefore, a hollow product can be obtained. Further, when the compound represented by the general formula (I) is used as the amphoteric compound, the fibrous substance is dissolved at a temperature of 70 ° C. or higher, and therefore it is coated in water at a temperature of 70 ° C. or higher, preferably boiling water. The core material can be dissolved by immersing the fibrous material. The hollow shaped product obtained after dissolving the core material formed of the fibrous material can be collected by filtration or the like.

In the method for producing a hollow shaped article of the present invention, the hollow shaped article can be produced by the above steps (A), (B) and (C) without generating harmful gas such as carbon dioxide. Further, in the method for producing a hollow article according to the present invention, the core material formed from the fibrous material is dissolved in the step (C), and the amphoteric compound remains after the core material is dissolved. Therefore, it is possible to reuse (step D) by recovering the remaining amphoteric compound. Therefore, the material that serves as the template can be reused, the product utilization rate can be improved, and the waste of resources can be eliminated.

Step D will be described. As a method for recovering the amphoteric compound, when a core material formed of a fibrous material is dissolved in a sodium hydroxide solution, a method of recovering the amphoteric compound by neutralizing the solution by using dilute hydrochloric acid or the like is used. Can be mentioned. When the coated fibrous material is immersed in boiling water to dissolve the core material, the amphoteric compound can be recovered by cooling the filtrate.

In the above description, the method for producing a hollow fibrous material has been described, but the shape that can be produced by the method for producing a hollow shaped material of the present invention is not limited to a fibrous material, and a hollow shaped material can be used. Any kind of material can be manufactured. When forming a fiber from an amphoteric compound capable of forming a fibrous material, it is possible to adjust the axial diameter, length, etc. of the obtained fiber by adjusting the conditions for forming the fiber, and not the fibrous shape. For example, a hollow shape such as a box shape or a star shape can be formed, and a large number of fibers can be bundled to form a hollow shape having a larger shaft diameter than the fibers.

Using the method for producing a hollow article according to the present invention,
When a hollow metal fiber is produced, a hollow metal fiber having a large surface area can be obtained, so that it can be used as an electrode plate of a fuel cell or a secondary battery, a catalyst, a catalyst carrier, a display electrode, an electrode for a mobile phone, or the like. .

[0053] Example Hereinafter, further detailed explanation of the present invention embodiment. Needless to say, the scope of the present invention is not limited to such examples.

Example 1 (Step A) 1 g of a powder of 6- {2-sec-butyl-4- (4-pyridylazo) phenoxy} hexanoic acid represented by the following chemical formula (II) was added to a sodium hydroxide aqueous solution 10 having a pH of 12:
A homogeneous 6- {2-sec-butyl-
An aqueous solution containing 4- (4-pyridylazo) phenoxy} hexanoic acid was prepared.

[0055]

[Chemical 4]

The above 6- {2-sec-butyl-4-
An aqueous solution containing (4-pyridylazo) phenoxy} hexanoic acid is allowed to stand in the atmosphere for 1 week to lower the pH to 8,
An organic fiber having a shaft diameter of 1 to 10 μm and a length of about 700 μm was formed.

Example 2 (Step A) 1 g of a powder of 6- {2-sec-butyl-4- (4-pyridylazo) phenoxy} hexanoic acid represented by the above chemical formula (II) was added to 100 g of an aqueous solution of sodium hydroxide having a pH of 100.
Homogeneous 6- {2-sec-butyl-4, dissolved in 0 ml
An aqueous solution containing-(4-pyridylazo) phenoxy} hexanoic acid was prepared. 6- {2-sec-butyl-4-
Carbon dioxide was blown into the aqueous solution containing (4-pyridylazo) phenoxy} hexanoic acid for 3 hours (blowing amount: 10
0ml / min), shaft diameter 1-10μm, length about 100μ
m organic matter fibers were formed.

Example 3 (Step B) After washing the organic fibers obtained in Examples 1 and 2 with deionized water, 6 × 10 ⁻³ % by mass of palladium (II) chloride, 0.6% by mass. Dissolved% sodium chloride,
It was immersed in 500 ml of an acetate buffer solution (0.1 mol dm ⁻³ ) having a pH of 5 and allowed to stand at room temperature for 30 minutes. After leaving still for 30 minutes, it was washed with deionized water. Then, the organic fibers washed with deionized water were mixed with 1.5% by mass of nickel hypophosphite hexahydrate, 1.2% by mass of boric acid, and 0.2% by mass.
It was immersed in an electroless nickel plating bath (a) having a pH of 5.5 containing 4% by mass of sodium acetate and 0.12% by mass of ammonium sulfate, and allowed to stand at room temperature for 30 minutes. The organic fibers then contain 4.5% by weight nickel hypophosphite hexahydrate, 1.2% by weight boric acid, 0.24% by weight sodium acetate, 0.12% by weight ammonium sulfate. p
Dip in H5.5 electroless plating bath (b) for 24 hours at room temperature
After standing for a while, washing with deionized water was performed to obtain an organic fiber coated with metallic nickel.

Example 4 The procedure of Example 3 was repeated, except that the electroless nickel plating bath (b) was adjusted to pH 3 by adding hydrochloric acid.
An organic fiber partially coated with nickel metal was obtained.

Example 5 The same operation as in Example 3 was carried out except that the electroless nickel plating bath (b) was adjusted to pH 9 by adding an aqueous sodium hydroxide solution, and a lumpy nickel deposit was deposited. The obtained organic fiber was obtained.

Example 6 (Step B) After washing the organic fiber obtained in Example 1 with deionized water, 0.5% by mass of tin (II) chloride dihydrate and 1N dilute hydrochloric acid were added to 0%. The washed organic fiber was immersed in 100 ml of an aqueous solution containing 0.2 ml. After leaving it for 2 minutes at room temperature, it was washed with deionized water. Next, 0.026% by mass of palladium (II) chloride and 1 N of dilute hydrochloric acid were added to 0.05 m.
The organic fiber treated with the tin (II) chloride aqueous solution was immersed in the aqueous solution containing 1 l. After leaving it at room temperature for 5 minutes, it was washed with deionized water to obtain an organic fiber on which a catalyst was adsorbed. The obtained organic fiber was immersed in the electroless nickel plating bath (a) used in Example 3 and allowed to stand at room temperature for 120 minutes, followed by washing with deionized water, and an organic fiber coated with metallic nickel Got

Example 7 (Step C) The organic fibers coated with metallic nickel obtained in Examples 3 and 6 were immersed in an aqueous sodium hydroxide solution having a pH of 14 and allowed to stand at room temperature for 24 hours to obtain organic fibers. Was dissolved. It was filtered using a 0.2 μm pore size PTFE membrane filter and washed with deionized water to obtain a hollow nickel tube. A scanning electron micrograph of the obtained nickel tube is shown in FIG. A similar hollow nickel tube was obtained when the organic fiber obtained in Example 1 was used and when the organic fiber obtained in Example 2 was used. As shown in FIG. 2, the nickel tube obtained by the present invention has a hollow shape and does not have a step of sintering as described above, so that no harmful gas such as carbon dioxide is generated.

Example 8 The organic fibers coated with metallic nickel obtained in Examples 3 and 6 were immersed in boiling water to dissolve the organic fibers. PT with 0.2 μm pore size as in Example 7
A hollow nickel tube was obtained by filtration using a FE membrane filter and washing with deionized water. The obtained hollow nickel tube also had the same shape as that obtained in Example 7 (not shown).

Example 9 (Process D) The filtrate (alkaline) filtered with a membrane filter in Example 7 was neutralized with dilute hydrochloric acid to give an amphoteric compound (6- {2-sec-butyl-4-). An aqueous solution containing (4-pyridylazo) phenoxy} hexanoic acid) was obtained. 6
The aqueous solution containing-{2-sec-butyl-4- (4-pyridylazo) phenoxy} hexanoic acid was filtered, washed with deionized water, and then recrystallized from boiling water to give a pure amphoteric compound, 6- {. A powder of 2-sec-butyl-4- (4-pyridylazo) phenoxy} hexanoic acid was obtained. 6-
The recovery rate of {2-sec-butyl-4- (4-pyridylazo) phenoxy} hexanoic acid was 90%.

[0065]

As described above, the method for producing a hollow shaped article according to the present invention is an environmentally friendly method for producing a hollow shaped article which does not generate harmful gas such as carbon dioxide during production. Further, in the method for producing a hollow shaped article of the present invention,
Since the fiber serving as the template can be easily dissolved without burning out, the amphoteric compound capable of forming the fiber can be recovered to provide a recycling method for recycling. When a hollow metal fiber is produced by the method for producing a hollow shaped article of the present invention, since the obtained hollow metal fiber has a large surface area, an electrode plate of a fuel cell or a secondary battery, a catalyst, a catalyst carrier, a display electrode, It can be used as an electrode for mobile phones.

[Brief description of drawings]

FIG. 1 is a diagram illustrating steps of a method for manufacturing a hollow article according to the present invention.

FIG. 2 is a scanning electron micrograph of a hollow nickel tube obtained by the method for producing a hollow article according to the present invention.

Continued front page    (72) Inventor Kunihiro Ichimura             2-13-7 Kirigaoka, Midori-ku, Yokohama-shi, Kanagawa F-term (reference) 4G069 AA02 AA08 BB02A BB04A                       BC68B DA05 EA03X EA03Y                       EB06 FA01 FB21 FB48                 4K022 AA13 AA24 AA34 AA41 AA43                       BA01 BA03 BA06 BA08 BA14                       BA17 BA18 BA21 BA28 DA01                       EA01                 4L031 AA25 AB06 BA11 BA18 CA01                       CB12                 4L037 AT01 CS10 FA02 FA04 PA36                       UA04 UA14

Claims (9)

[Claims] 1. A step of: (A) dissolving an amphoteric compound capable of forming a fibrous substance in water to prepare an aqueous amphoteric compound solution, forming a fibrous substance from the amphoteric compound aqueous solution, and obtaining a fibrous substance-containing aqueous solution. (B) The fibrous material in the fibrous material-containing aqueous solution is coated with a metal material or a metal oxide, and a core material formed of the fibrous material and an exterior material formed of the metal material or the metal oxide. And (C) a hollow shaped article formed of a metal material or a metal oxide by dissolving the core material formed of the fibrous article of the coated fibrous material. A method for producing a hollow shaped article, which comprises: 2. The method for producing a hollow article according to claim 1, wherein the amphoteric compound is a compound having a carboxyl group and a pyridyl group. 3. The method for producing a hollow shaped article according to claim 2, wherein the amphoteric compound is a compound represented by the following general formula (I). [Chemical 1] (In the formula, R is hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms, and m is an integer of 1 to 20.) 4. The hollow according to claim 1, wherein the core material formed of the fibrous material is dissolved by changing the hydrogen ion concentration or temperature of the fibrous material-containing aqueous solution. Method of manufacturing shaped objects. 5. The fibrous material is formed by placing the amphoteric compound aqueous solution under a carbon dioxide atmosphere.
4. The method for producing a hollow shaped article according to any one of 4 above. 6. The method for producing a hollow shaped article according to claim 1, wherein the fibrous material is coated with a metal material by electroless plating. 7. The method for producing a hollow shaped article according to claim 1, wherein the obtained hollow shaped article is a hollow metal fiber. 8. The amphoteric compound is an amphoteric compound recovered from the core material dissolved in the step (C).
The method for manufacturing the hollow shaped article according to claim 1. 9. A hollow shaped article obtained by the method for producing a hollow shaped article according to claim 1.