High-purity copper acetate

Abstract

We provide high-purity copper acetate that can be used in the production of high-purity copper particles. [Solution] Copper acetate with a purity of 99.99 wt% or higher.

Description

Technical Field

[0001] The present invention relates to high-purity copper acetate and a method for producing the same.

Background Art

[0002] In recent years, functional liquid materials containing metal nanoparticles have attracted attention. In particular, materials using copper nanoparticles, which are more advantageous in terms of cost than silver nanoparticles, have attracted attention.

[0003] Copper acetate can be used as a starting material for copper nanoparticles. High-purity copper acetate is required for the production of high-purity copper nanoparticles.

[0004] Patent Document 1 discloses a method for producing copper acetate by reacting atacamite (Cu2(OH)3Cl) with acetic acid. Patent Document 1 states that insoluble atacamite can be solubilized by this method to recover copper. However, the obtained copper acetate is in the form taken to solubilize atacamite and recover copper, and its purity is not disclosed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, an object of the present invention is to provide high-purity copper acetate that can be used for the production of high-purity copper particles.

Means for Solving the Problems

[0007] As a result of intensive research and development by the present inventors, the production of high-purity copper acetate was realized, and the present invention was achieved.

[0008] Therefore, the present invention includes (1) the following: (1) Copper acetate with a purity of 99.99 wt% or higher. [Effects of the Invention]

[0009] This invention provides high-purity copper acetate. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an explanatory diagram of the apparatus used for electrolytic dissolution. [Figure 2] Figure 2 is a graph showing the results of the XRD analysis for sample 1. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below with reference to specific embodiments. The present invention is not limited to the specific embodiments disclosed below.

[0012] [High-purity copper acetate] This invention relates to copper acetate with a purity of 99.99 wt% or higher.

[0013] Furthermore, in a preferred embodiment, the purity of the copper acetate of the present invention can be, for example, 99.99 wt% or higher, or 99.990 wt% or higher, 99.991 wt% or higher, 99.992 wt% or higher, 99.993 wt% or higher, 99.994 wt% or higher, 99.995 wt% or higher, 99.996 wt% or higher, 99.997 wt% or higher, 99.998 wt% or higher, 99.999 wt% or higher, or 99.9991 wt% or higher, 99.9992 wt% or higher, 99.9993 wt% or higher, 99.9994 wt% or higher, or 99.9995 wt% or higher.

[0014] According to the copper acetate of the present invention, high-purity copper particles can be easily produced.

[0015] [purity] The purity of copper acetate was calculated by the means disclosed in the examples described below.

[0016] In a preferred embodiment, the purity of the copper acetate of the present invention is the purity calculated after excluding hydrogen, carbon, oxygen, sulfur, chlorine, nitrogen, and phosphorus.

[0017] [Impurity content] In a preferred embodiment, in the high-purity copper acetate of the present invention, the content of the following impurity elements can be made the following contents respectively. The values of the impurity content can be measured by the means described below in the examples:

[0018] Na content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Al content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, less than 0.05 wtppm; K content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Ca content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Sc content: 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm;

[0019] Cr content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, less than 0.05 wtppm; Fe content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Ni content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, less than 0.05 wtppm; Ag content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, less than 0.05 wtppm;

[0020] Si content: 10 wtppm or less, 5 wtppm or less, 4 wtppm or less, 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm; S content: 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm; Cl content: 150 wtppm or less, 100 wtppm or less, less than 100 wtppm;

[0021] Li content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm;<00,00103>Be content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; B content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, 0.001 wtppm or less, less than 0.001 wtppm; C content: 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm;

[0022] N content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, less than 0.05 wtppm; O content: 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm; Mg content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; <,

[0023] P content: 5 wtppm or less, 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm; Ti content: 1 wtppm or less, 0.5 wtppm or less, 0.4 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; V content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm;

[0024] Mn content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Co content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Zn content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm;

[0025] Ga content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Gluten content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, less than 0.005 wtppm; As content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm;

[0026] Zr content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Nb content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Mo content: 1 wtppm or less, 0.5 wtppm or less, 0.3 wtppm or less, 0.2 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; Pd content: 3 wtppm or less, 2 wtppm or less, 1 wtppm or less, less than 1 wtppm; Cd content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, less than 0.01 wtppm;

[0027] Sn content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, less than 0.01 wtppm; Sb content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, 0.002 wtppm or less, less than 0.002 wtppm; Ba content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, 0.001 wtppm or less, less than 0.001 wtppm; W content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, 0.001 wtppm or less, less than 0.001 wtppm;

[0028] Au content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, less than 0.01 wtppm; Hg content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, less than 0.01 wtppm; Pb content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, 0.002 wtppm or less, less than 0.002 wtppm;

[0029] Bi content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, 0.05 wtppm or less, 0.01 wtppm or less, 0.005 wtppm or less, 0.001 wtppm or less, less than 0.001 wtppm; Th content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm; U content: 1 wtppm or less, 0.5 wtppm or less, 0.1 wtppm or less, less than 0.1 wtppm.

[0030] [Hydrate] In a preferred embodiment, the copper acetate of the present invention may be in the form of a hydrate or an anhydrous, or in the form of a mixture of a hydrate and an anhydrous. For example, the hydrate may be a monohydrate. The number of hydrates of the hydrate can be determined by measuring the mass after heating and drying and comparing it to the mass before drying.

[0031] In a preferred embodiment, the hydration number of the copper acetate hydrate of the present invention can be controlled to a desired hydration number by heating and drying. Heating and drying can be carried out, for example, by maintaining a temperature in the range of 100 to 200°C under atmospheric pressure for 60 to 120 minutes.

[0032] [Production of copper acetate] The copper acetate of the present invention can be produced by the production method described later in the examples. Specifically, it can be produced by a method that includes the steps of electrolytically dissolving 6N-Cu, which is the raw material, using the electrolytic dissolution apparatus and conditions disclosed in the examples, concentrating copper acetate in an anolite, precipitating copper acetate from the obtained concentrated solution, and recovering the precipitated copper acetate.

[0033] [Preferred embodiments of the present invention] In preferred embodiments, the present invention includes (1) and the following: (1) Copper acetate with a purity of 99.99 wt% or higher. (2) Copper acetate as described in (1), wherein the purity is calculated by excluding hydrogen, carbon, oxygen, sulfur, chlorine, nitrogen, and phosphorus. (3) Copper acetate as described in (1), wherein the sodium content is 1 wt ppm or less. (4) Copper acetate as described in (1), wherein the aluminum content is 1 wt ppm or less. (5) Copper acetate as described in (1), wherein the potassium content is 1 wt ppm or less. (6) Copper acetate as described in (1), wherein the calcium content is 1 wt ppm or less. (7) Copper acetate as described in (1), wherein the chromium content is 1 wt ppm or less. (8) Copper acetate as described in (1), wherein the iron content is 1 wt ppm or less. (9) Copper acetate as described in (1), wherein the nickel content is 1 wt ppm or less. (10) Copper acetate as described in (1), wherein the silver content is 1 wt ppm or less. (11) Copper acetate as described in (1), with a purity of 99.995 wt% or higher. (12) Copper acetate as described in (1), with a purity of 99.999 wt% or higher. (13) The copper acetate according to (1), wherein the copper acetate is in the form of anhydrous or hydrated form. [Examples]

[0034] The present invention will be described in detail below with reference to examples. The present invention is not limited to the examples illustrated below.

[0035] [Example 1: Case 1] [Electrolysis device] Figure 1 shows a diagram illustrating the apparatus used for electrolytic dissolution.

[0036] The electrolytic apparatus comprises an electrolytic dissolution tank 1 and an external cathode tank 19. The electrolytic dissolution tank 1 comprises an anode 3 and a cathode box 11.

[0037] For anode 3, the raw material 6N-Cu is molded and used. Anode 3 is immersed in anolite 7. Alternatively, instead of anode 3, an anode box (not shown) can be installed and the raw material 6N-Cu can be placed inside for use.

[0038] Inside the cathode box 11, a titanium plate is used as the cathode 9, and the cathode 9 is immersed in the cathodeite 13. The cathodeite 13 is separated from the anolite 7 outside the cathode box by an anion exchange membrane.

[0039] The electrolytic dissolution tank 1 is equipped with a stirring bar (not shown), which allows for stirring throughout the electrolytic dissolution process.

[0040] A circulation path is formed in the external cathodelite tank 19, through which the cathodelite 13 from the cathode box 11 is introduced via the acid-resistant tube 17, and the introduced cathodelite 13 is then introduced back into the cathode box 11 via the acid-resistant tube 17.

[0041] As electrolytic dissolution progresses, copper acetate is generated, consuming the acetic acid in the anolite and catholite. Therefore, by adding acetic acid to the catholite in the external catholite tank 19, the amount of acetic acid consumed is replenished, and the concentration of acetic acid in the anolite and catholite can be maintained at a constant level.

[0042] [Production of copper acetate solution and production of copper acetate by electrolysis] Electrolytic dissolution was performed using the electrolytic dissolution apparatus shown in Figure 1. The conditions for electrolytic dissolution were as follows: Anolite at the start of electrolysis: Dilute acetic acid (concentration 20-30 wt%) Castholite at the start of electrolysis: Acetic acid (concentration 80-85 wt%) Anode: 6N-Cu Cathode: Titanium plate

[0043] Table 1 shows the GDMS analysis results for 6N-Cu used as the anode. In Table 1, the unit of analysis for each impurity element is wtppm, and values ​​less than (<) indicate that the value was below the detection limit.

[0044] [Table 1]

[0045] By adding acetic acid to the cassolite in the external cassolite tank 19, the concentration of acetic acid in the anolite was maintained within the range of 20-30 wt%. Electrolytic dissolution was performed using a constant voltage of 7.0V. The process involved applying electricity for 2-3 weeks to dissolve high-purity copper into the anolite. As the dissolution of high-purity copper began, the color of the solution changed from colorless and transparent to a deep blue-green. The dissolution electrolysis was terminated when the concentration of copper acetate in the solution reached approximately 0.57 wt% to 0.73 wt%. The anolite was recovered and concentrated under reduced pressure using an evaporator to precipitate copper acetate crystals. The reduced pressure concentration using the evaporator was performed under vacuum while maintaining a bath temperature of 55°C and centrifugal rotation speed of 60 rpm. The initial liquid volume was approximately 1500 mL, which was concentrated under reduced pressure until the liquid volume was approximately 300 mL, precipitating 6-9 g of copper acetate. Next, the precipitated copper acetate was recovered. The precipitated copper acetate was recovered by taking a slurry containing the anolite solution and the precipitated crystals, and separating the solid and liquid by suction filtration. The solid obtained by solid-liquid separation was dried to obtain copper acetate crystals (Sample 1).

[0046] [Analysis of copper acetate crystals] The elements contained in the recovered copper acetate crystals were analyzed. Na, Al, Si, K, Ca, Cr, Fe, Ni, Ag, S, and Cl were analyzed by ICP-MS (inductively coupled plasma mass spectrometry), and Cu was analyzed by ICP-OES (inductively coupled plasma atomic emission spectrometry). The results obtained from the analysis are shown in Table 2. In Table 2, the unit of the analytical value of each contained impurity element is wtppm, and values ​​less than (<) indicate that the value was below the detection limit.

[0047] [Table 2]

[0048] Based on the analysis results, the purity of copper acetate was calculated to be 99.99948 wt%. In the calculation, the elements measured in Table 2 were used as impurities. Elements not measured in Table 2 were considered to not increase or decrease based on the principles of the experimental procedure, so the elemental content of 6N-Cu used as the anode was calculated using the elemental content measured in Table 1. However, among the elements in Tables 1 and 2, hydrogen, carbon, oxygen, sulfur, chlorine, nitrogen, and phosphorus were removed as gaseous components when copper particles were produced by reduction from copper acetate, and therefore were not used in the purity calculation.

[0049] Purity was calculated by focusing on the impurity content of metal elements. Excluding hydrogen, carbon, oxygen, sulfur, chlorine, nitrogen, and phosphorus from the elements listed in Tables 1 and 2 above, the impurity content was considered and substituted into the formula: 100 wt% - (total metal impurity content in wt ppm / 10000) wt%. In calculating the impurity content, values ​​below the detection limit were treated as if they were at the detection limit.

[0050] [Measurement of hydration number] The obtained copper acetate crystals were found to be almost monohydrate by XRD analysis under the following conditions.

[0051] XRD was performed using a Rigaku SmartLab fully automated horizontal multi-purpose X-ray diffractometer under the following conditions: Tube: Cu (measured using CuKα) Tube voltage: 40kV, Tube current: 30mA, Optical system: Focused diffraction optical system Scan mode (2θ / θ): 10°, Scan range (2θ): 10°~60° Measurement step (2θ): 10°, Scan speed (2θ): 20° / min Filter: CuKβ filter, Divergence slit: 2 / 3° Entrance slit: 0.150 mm, longitudinal limiting slit: 10.0 mm, Light-receiving slit 1: 1,000 mm, light-receiving slit 2: 0.150 mm.

[0052] Figure 2 shows the results obtained from XRD analysis of sample 1. For control, the chart in Figure 2 also shows the XRD analysis chart of copper acetate monohydrate obtained from the database. From the comparison of characteristic peaks, it was found that at least 99 wt% of the copper acetate crystals in sample 1, and probably the entire amount (100 wt%), is in the form of monohydrate, based on the observation that there are no peaks other than monohydrate.

[0053] [Potential contribution to the SDGs] One embodiment of the present invention provides high-purity copper acetate that can be used to manufacture high-purity copper particles. Since high precision of materials and components is important for the development of IoT and AI technologies, one embodiment of the present invention has the potential to contribute to the development of IoT and AI technologies. For this reason, one embodiment of the present invention has the potential to contribute to Goal 9 of the United Nations Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation." [Industrial applicability]

[0054] This invention provides high-purity copper acetate that can be used in the production of high-purity copper particles. This invention is industrially useful.

Claims

1. Copper acetate with a purity of 99.99 wt% or higher.

2. The copper acetate according to claim 1, wherein the purity is calculated by excluding hydrogen, carbon, oxygen, sulfur, chlorine, nitrogen, and phosphorus.

3. The copper acetate according to claim 1, wherein the sodium content is 1 wt ppm or less.

4. The copper acetate according to claim 1, wherein the aluminum content is 1 wt ppm or less.

5. The copper acetate according to claim 1, wherein the potassium content is 1 wt ppm or less.

6. The copper acetate according to claim 1, wherein the calcium content is 1 wt ppm or less.

7. The copper acetate according to claim 1, wherein the chromium content is 1 wt ppm or less.

8. The copper acetate according to claim 1, wherein the iron content is 1 wt ppm or less.

9. The copper acetate according to claim 1, wherein the nickel content is 1 wt ppm or less.

10. The copper acetate according to claim 1, wherein the silver content is 1 wt ppm or less.

11. The copper acetate according to claim 1, wherein the purity is 99.995 wt% or higher.

12. The copper acetate according to claim 1, wherein the purity is 99.999 wt% or higher.

13. The copper acetate according to claim 1, wherein the copper acetate is in the form of an anhydrous or hydrated form.

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