JP2017172003A - Manufacturing method of copper nanoparticles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of copper nanoparticles capable of simply providing copper nanoparticles with single dispersion.SOLUTION: A manufacturing method of copper nanoparticles has a preparation process for preparing a reaction solution by dissolving a first metal salt containing copper, a complexing agent, a dispersant, a second metal salt containing a metal lower in ionization tend than copper in water and a deposition process for depositing copper nanoparticles by adding a reductant while stirring the reaction solution.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing copper nanoparticles.

  In recent years, there has been a demand for a method for producing metal particles for use in a method of printing a pattern directly on a substrate by a printing method such as inkjet printing using a metal particle dispersion, and for use as a light emitting material, a catalyst material, etc. ing.

  Since copper particles generally used as wiring have a large surface area, there is a problem that they are easily oxidized and difficult to synthesize.

  As a method for producing such copper particles, for example, Patent Document 1 discloses a step of mixing a compound containing copper and a reducing compound and thermally decomposing in an alkylamine to produce a composite compound capable of producing copper. And a method of coating the composite compound with a polymer having at least one of a carboxyl group and a specific phosphorus-containing functional group.

  For example, Patent Document 2 discloses a method of synthesizing coated copper fine particles by heating and reducing a polyol solution containing copper ions with a microwave.

  Furthermore, in Patent Document 3, for example, at least one of malic acid and malate, and gluconic acid and gluconate is used as a complexing agent, and reduced at approximately room temperature (35 ° C.) to synthesize metal nanoparticles. A method is disclosed.

Japanese Patent Laying-Open No. 2015-124415 JP 2014-224276 A JP 2012-172170 A

  However, Patent Document 1 has problems that it is difficult to synthesize in large quantities, such as the point that it takes time to synthesize the polymer to be coated, the point that a high temperature of 100 ° C. is applied in alkylamine, and hydrazine is used.

  Moreover, in patent document 2, there exists a subject that mass synthesis | combination is difficult from the point which needs to set it as high temperature of 185 degreeC, and the point of the synthesis | combination density | concentration being very low once.

  Moreover, in patent document 3, since it is necessary to utilize 2 types as a metal salt, and the synthesized metal nanoparticles are also 2 types, there exists a subject that a metal nanoparticle cannot be selectively synthesize | combined.

  Thus, the manufacturing method of the copper nanoparticle which can manufacture a monodispersed copper nanoparticle simply is calculated | required.

  This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method of the copper nanoparticle which can obtain a monodispersed copper nanoparticle simply.

In order to achieve the above object, a method for producing copper nanoparticles according to the present invention includes:
A preparation step of preparing a reaction solution by dissolving a first metal salt containing copper, a complexing agent, a dispersant, and a second metal salt containing a metal having a lower ionization tendency than copper in water;
While stirring the reaction solution, a reducing agent is added, and a precipitation step of precipitating copper nanoparticles,
It is characterized by providing.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the copper nanoparticle which can obtain a monodispersed copper nanoparticle simply can be provided.

  Hereinafter, the manufacturing method of the copper nanoparticle which concerns on embodiment of this invention is demonstrated in detail.

  First, the copper nanoparticles in the present specification mean particles having an average particle diameter of about 1 nm to about 200 nm. The average particle size of the copper nanoparticles is particularly preferably about 1 nm to about 100 nm. The particle size distribution is measured using a laser diffraction / scattering particle size distribution measuring device (for example, LA-920, manufactured by Horiba, Ltd.), and the average particle size is indicated by D50 (volume basis).

  In this embodiment, after preparing a reaction solution as described in detail below, copper nanoparticles are precipitated by dropping a reducing agent into the reaction solution while stirring the reaction solution, Produce copper nanoparticles. The reaction solution of this embodiment is a solution containing copper ions and further dissolving a metal salt, a complexing agent and a dispersing agent in water. As water, for example, ion exchange water is used. The water used in this embodiment is not limited to ion exchange water.

The copper ion is a divalent copper ion (Cu ²⁺ ). The copper ions are supplied into the reaction solution using, for example, a first metal salt that can supply copper ions into the reaction solution by dissolving in copper. As the first metal salt containing copper, for example, copper (II) chloride dihydrate is used. The first metal salt is not limited to copper chloride (II) dihydrate as long as it dissolves in water and generates copper (II) ions, and any material can be used.

  The second metal salt is a metal salt containing a divalent metal having a lower ionization tendency than copper. The second metal salt is a divalent metal chloride having a lower ionization tendency than copper, for example, tin (II) chloride, iron (II) chloride, nickel (II) chloride, cobalt (II) chloride, or One or more selected from the group consisting of zinc chloride can be used.

  In the present embodiment, it is particularly preferable to use tin (II) chloride (tin (II) chloride hydrate) as the second metal salt. Further, the second metal salt is more dissolved than the copper ion (or the first metal salt) in the reaction solution in terms of the number of moles.

  The complexing agent converts metal ions into metal complexes and stabilizes them in solution. In this embodiment, ethylenediaminetetraacetic acid disodium dihydrate (hereinafter referred to as EDTA-2Na) and trisodium citrate dihydrate are used as complexing agents. In addition, it is also possible to use things other than these as a complexing agent. The amount of trisodium citrate dihydrate is desirably in the range of 1.5 to 5.0 mol / L with respect to 1 mol / L of the second metal salt (for example, tin chloride) in the reaction solution, More desirably, it is 1.5 to 3.0 mol / L.

  A dispersing agent disperses the deposited copper nanoparticles well in the solution. As the dispersant, polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), gelatin, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether phosphate, N-acyl amino acid salt, or alkyl ether carboxylate is used. One or more selected from the group can be used. As the dispersant, polyvinyl pyrrolidone and polyvinyl alcohol are preferable, and polyvinyl pyrrolidone is particularly preferable.

  Taking PVP as an example, the molecular weight of PVP is preferably in the range of 30,000 to 400,000, more preferably 30,000 to 60,000. Moreover, K = 30 PVP (molecular weight 40,000) is particularly preferable. In the reaction solution, PVP is preferably contained in an amount of 1 to 15 parts by weight, more preferably 1 to 2 parts by weight, with respect to 100 parts by weight of water.

  Next, as the reducing agent, a material capable of reducing copper ions, for example, a titanium (III) chloride solution is used. The concentration of the titanium (III) chloride solution is, for example, 22% by weight, but other concentrations may be used. Further, as the reducing agent, a solution other than titanium (III) chloride may be used.

Next, in this embodiment, copper nanoparticles are manufactured by the following method.
First, a reaction solution is prepared by the following procedure. Here, the reaction solution preparation step and the reduction step are both performed in a room temperature environment. The room temperature is, for example, about 15 ° C to 30 ° C, or about 20 ° C to 25 ° C. Moreover, in this embodiment, it is not necessary to heat or cool a reaction solution or a reducing agent in any of the reaction solution preparation step and the reduction step.

  First, a second metal salt, a complexing agent, and a dispersing agent are dissolved in pure water, for example, ion exchange water. As the second metal salt, for example, tin (II) chloride dihydrate is used. As the complexing agent, for example, trisodium citrate hydrate and EDTA-2Na are used. Further, polyvinyl pyrrolidone (K = 30) is used as a dispersant.

  Further, with respect to 100 parts by weight of ion-exchanged water, 1.8 parts by weight of tin (II) chloride hydrate, 7.0 parts by weight of trisodium citrate hydrate, 3.0 parts by weight of EDTA-2Na, polyvinylpyrrolidone (K = 30) Add 1.5 parts by weight.

  Next, the mixture is stirred until the second metal salt is completely dissolved. Next, in order to supply copper ions, a first metal salt such as copper (II) chloride dihydrate is added, and the reaction solution is further stirred. For example, 0.5 parts by weight of copper (II) chloride hydrate is added. When the copper (II) chloride dihydrate is completely dissolved, the preparation of the reaction solution is finished.

  Next, a reducing agent is dropped while stirring the above reaction solution. As the reducing agent, for example, a titanium (III) chloride solution (for example, Wako Pure Chemical Industries, Ltd.) is used. The concentration of the titanium (III) chloride solution is, for example, 22% by weight. Further, the dropped titanium (III) chloride solution is, for example, 5 parts by weight, and the titanium (III) chloride contained in the titanium (III) chloride solution is 1.1 parts by weight.

  As it is, for example, stirring is continued for about 15 minutes to precipitate copper nanoparticles. After the precipitation of the copper nanoparticles, the copper particles are separated from the solution using a centrifuge. Subsequently, cleaning is performed using pure water. Separation and washing may be performed multiple times. Thereby, monodispersed copper nanoparticles are obtained.

  In the manufacturing method of the present embodiment, copper is added by adding a reducing agent while stirring a reaction solution in which a first metal salt, a second metal salt, a complexing agent, and a dispersing agent that supply copper ions are dissolved. Nanoparticles can be deposited. Neither solution needs to be heated or cooled, and the solvent can utilize water. The reaction solution can be prepared and the reduction step can be performed at room temperature. Thus, in this embodiment, the heat processing exceeding 100 degreeC and the process by a base are not required, for example. Further, the time for adding and stirring the reducing agent is about 15 minutes, which is in units of minutes, and the reaction time is extremely short as compared with the production method that requires reaction time in units of hours.

  Therefore, the manufacturing method of this embodiment is simpler than the conventional manufacturing method. Furthermore, copper nanoparticles can be produced under mild and neutral conditions. In addition, since the conditions are mild, mass synthesis is facilitated. Furthermore, the manufacturing method of the present embodiment is a safe method for workers.

  In the present embodiment, only pure water is used as a solvent, so there is almost no obstacle when processing the produced copper nanoparticles into applications such as conductive ink and paste, and secondary use is easy. It also has the excellent effect of being.

  Thus, according to the manufacturing method of the present embodiment, monodispersed copper nanoparticles can be manufactured under simple conditions.

Example 1
In Example 1, as shown in Table 1, copper (II) chloride dihydrate was used as the first metal salt for supplying copper ions. In addition, tin (II) chloride dihydrate was used as the second metal salt. Further, trisodium citrate dihydrate and EDTA-2Na (dihydrate) were used as complexing agents. As a dispersant, polyvinylpyrrolidone (K = 30) was used. As the reducing agent, a titanium (III) chloride solution (Wako Pure Chemical Industries, Ltd.) was used. A titanium (III) chloride solution having a concentration of 22% by weight was used. In Table 1, “hydrate” of each material is omitted.

  Under a room temperature (20 ° C. to 25 ° C.) environment, 1.8 g of tin (II) chloride hydrate, 7.0 g of trisodium citrate dihydrate, EDTA-2Na (dihydrate) Product) 3.0 g and polyvinylpyrrolidone (K = 30) 1.5 g were added and stirred until the tin (II) chloride hydrate was completely dissolved. To the prepared solution, 0.5 g of copper (II) chloride dihydrate was added and further stirred for about 5 minutes. A reaction solution was prepared by the above steps.

  While stirring the above reaction solution at 700 rpm, 4.0 ml of a titanium (III) chloride solution (specific gravity: about 1.23 g / ml) was slowly added dropwise. The concentration of the titanium (III) chloride solution was 22% by weight. Stirring was continued for 15 minutes as it was to precipitate copper particles. After 15 minutes, the copper nanoparticles were separated from the reaction solution using a centrifuge. The separated copper nanoparticles were washed with pure water to obtain monodispersed copper nanoparticles.

  The copper particles thus obtained had an average particle size of 80.00 nm. The particle size distribution was measured using LA-920 (Laser diffraction / scattering particle size distribution measuring device) manufactured by Horiba, Ltd. The average particle size is D50 (volume basis).

  As is clear from Table 1, the deposition time of the copper particles was 3 minutes, and the particles could be deposited in a very short time. The average particle size was also 80.00 nm and 100 nm or less.

(Example 2)
In Example 2, the first metal salt, the second metal salt and the complexing agent are the same type and addition amount, and the dispersant type is the same, and only the addition amount of the dispersant is changed. went. Specifically, 3.0 g of the dispersing agent twice that of Example 1 was added.

  As apparent from Table 1, the stirring time was 15 minutes, and the copper particles were precipitated in 7 minutes. The average particle size was 110.00 nm.

(Example 3)
In Example 3, the first metal salt, the second metal salt and the complexing agent were the same in type and amount added, and the dispersant type was the same, and only the amount of dispersant added was changed. It was. Specifically, 15.0 g of the dispersant, 10 times that of Example 1, was added.

  As apparent from Table 1, the stirring time was 15 minutes and the copper particles were precipitated in 10 minutes. The average particle size was 93.00 nm.

Example 4
In Example 3, the first metal salt, the second metal salt and the complexing agent, the addition amount, and the addition amount of the dispersing agent were the same, and the experiment was performed by changing the type of the dispersing agent. Specifically, 1.5 g of polyvinyl alcohol (PVA) as in Example 1 was added as a dispersant. The molecular weight of polyvinyl alcohol (PVA) was 40,000.

  As apparent from Table 1, the stirring time was 15 minutes and the copper particles were precipitated in 3 minutes. Moreover, the average particle diameter was 125.00 nm.

(Comparative Example 1)
In Comparative Example 1, the experiment was performed by changing the addition amount of the dispersing agent with the same type and addition amount of the first metal salt, the second metal salt and the complexing agent, and the same type of dispersing agent. It was. The experiment was conducted with the same types and concentrations of copper chloride, tin chloride, and complexing agent, and only changing the concentration of the dispersant. Specifically, 0.75 g of a dispersant, which is half of that in Example 1, was added.

  As is apparent from Table 1, in Comparative Example 1, the stirring time was 15 minutes and the copper nanoparticles were precipitated in 3 minutes, but the average particle size was 330.00 nm.

(Comparative Example 2)
In Comparative Example 2, the first metal salt, the second metal salt, the complexing agent, the amount of addition, and the amount of dispersant added were the same, and the experiment was performed by changing the type of dispersant. Specifically, 1.5 g of gelatin (Wako Pure Chemical's reagent gelatin, grade Wako Grade 1) was added as a dispersant.

  As is clear from Table 1, in Comparative Example 2, the stirring time was 15 minutes and the copper particles were precipitated in 3 minutes, but the average particle size was 500.00 nm.

  From Examples 1 to 4 and Comparative Examples 1 and 2, in Examples 1 to 4, copper nanoparticles having an average particle diameter of 1 to 200 nm or less were precipitated within a stirring time of 15 minutes or less. It has been shown to be preferred. In particular, in Example 1, copper nanoparticles having an average particle diameter of 100 nm or less were obtained, and the precipitation time of the particles was 3 minutes, which was shorter than those in Examples 2 and 3. From these, the conditions of Example 1 were particularly suitable. Further, Example 4 in which the dispersant was changed was also preferable because the precipitation time was as short as 3 minutes. From the viewpoint of average particle diameter, it was shown that PVP is more preferable when the amount of the dispersant added is the same.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible. For example, in the above-described embodiment, a configuration using a hydrate is described as an example for copper (II) chloride, tin (II) chloride, trisodium citrate, EDTA-2Na, and the like. Without limitation, an anhydride may be used. For example, the description copper (II) chloride can include hydrates and anhydrides. Moreover, the mass of each material shown in Table 1 is an illustration to the last, and the quantity which uses each material can be increased / decreased suitably.

  In the above-described embodiment, the order in which the first metal salt for supplying copper ions, the second metal salt, the complexing agent, and the dispersing agent are dissolved is not limited to the above order, and depends on the material used. It can be changed as appropriate. For example, it is also possible to dissolve the second metal salt after dissolving the first metal salt. Further, the stirring time is also an example, and may be appropriately increased or decreased according to various conditions such as the amount of the reaction solution.

  Although several embodiments of the present invention have been described, the present invention is included in the invention described in the claims and the equivalents thereof. Hereinafter, the invention described in the scope of claims of the present application will be appended.

(Appendix 1)
A preparation step of preparing a reaction solution by dissolving a first metal salt containing copper, a complexing agent, a dispersant, and a second metal salt containing a metal having a lower ionization tendency than copper in water;
While stirring the reaction solution, a reducing agent is added, and a precipitation step of precipitating copper nanoparticles,
A method for producing copper nanoparticles, comprising:
(Appendix 2)
The second metal salt is a chloride containing a divalent metal having a lower ionization tendency than copper.
The manufacturing method of the copper nanoparticle of Additional remark 1 characterized by the above-mentioned.
(Appendix 3)
The reducing agent is a titanium (III) chloride solution.
The manufacturing method of the copper nanoparticle of Additional remark 1 or 2 characterized by the above-mentioned.
(Appendix 4)
The complexing agent is trisodium citrate, EDTA-2Na,
The method for producing copper nanoparticles according to any one of appendices 1 to 3, wherein:
(Appendix 5)
The second metal salt is tin (II) chloride.
The method for producing copper nanoparticles according to any one of supplementary notes 1 to 4, wherein:
(Appendix 6)
The first metal salt is copper (II) chloride.
The method for producing copper nanoparticles according to any one of supplementary notes 1 to 5, wherein:
(Appendix 7)
The dispersant is selected from the group consisting of polyvinyl pyrrolidone, polyvinyl alcohol, gelatin, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether phosphate, N-acyl amino acid salt, or alkyl ether carboxylate 1 One or more,
The method for producing copper nanoparticles according to any one of supplementary notes 1 to 6, wherein:
(Appendix 8)
The dispersant is polyvinylpyrrolidone,
1 to 15 parts by weight are included with respect to 100 parts by weight of the water,
The method for producing copper nanoparticles according to Supplementary Note 7, wherein:

Claims (8)

A preparation step of preparing a reaction solution by dissolving a first metal salt containing copper, a complexing agent, a dispersant, and a second metal salt containing a metal having a lower ionization tendency than copper in water;
While stirring the reaction solution, a reducing agent is added, and a precipitation step of precipitating copper nanoparticles,
A method for producing copper nanoparticles, comprising: The second metal salt is a chloride containing a divalent metal having a lower ionization tendency than copper.
The manufacturing method of the copper nanoparticle of Claim 1 characterized by the above-mentioned. The reducing agent is a titanium (III) chloride solution.
The manufacturing method of the copper nanoparticle of Claim 1 or 2 characterized by the above-mentioned. The complexing agent is trisodium citrate, EDTA-2Na,
The method for producing copper nanoparticles according to any one of claims 1 to 3, wherein: The second metal salt is tin (II) chloride.
The manufacturing method of the copper nanoparticle of any one of Claims 1 thru | or 4 characterized by the above-mentioned. The first metal salt is copper (II) chloride.
The method for producing copper nanoparticles according to any one of claims 1 to 5, wherein: The dispersant is selected from the group consisting of polyvinyl pyrrolidone, polyvinyl alcohol, gelatin, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether phosphate, N-acyl amino acid salt, or alkyl ether carboxylate 1 One or more,
The method for producing copper nanoparticles according to any one of claims 1 to 6, wherein: The dispersant is polyvinylpyrrolidone,
1 to 15 parts by weight are included with respect to 100 parts by weight of the water,
The manufacturing method of the copper nanoparticle of Claim 7 characterized by the above-mentioned.