JP2012193068A - Method of producing high-purity cupric oxide fine powder and method of supplying copper ion to copper sulfate solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high-purity cupric oxide fine powder having high purity of copper oxide and high solubility in a plating solution and a method for producing the same, and to electroplating copper using the high-purity cupric oxide powder. Provided is a method for supplying copper ions to an aqueous copper sulfate solution to be used.
SOLUTION: A method for producing high-purity cupric oxide fine powder, which uses flaky copper powder as a raw material, and pulverizes cupric oxide coarse powder obtained by heat treatment from the flaky copper powder, comprising oxygen A step of obtaining a cupric oxide coarse powder by primary heat treatment in a containing atmosphere; a step of obtaining a primary heat treated cupric oxide fine powder by pulverizing the cupric oxide coarse powder; And a secondary heat treatment of the copper fine powder in an oxygen-containing atmosphere.
[Selection] Figure 2

Description

  The present invention relates to a method for producing a high-purity cupric oxide fine powder and a method for supplying copper ions in an aqueous copper sulfate solution using the high-purity cupric oxide fine powder by the production method.

  Cupric oxide is used as a copper source for replenishing pigments, paints, catalysts, ceramic colorants and copper plating solutions. The manufacturing method is roughly classified into a wet method and a dry method.

The wet method is, for example, a method in which sodium hydroxide is reacted with an aqueous solution of cupric chloride or copper sulfate as described in Patent Document 1 to form copper hydroxide and then heated. More specifically, the etching waste solution of the printed circuit board containing cupric chloride is neutralized with caustic alkali, and the neutralized copper solution and caustic aqueous solution are simultaneously dropped into an aqueous solution maintained at a temperature of 40 to 50 ° C. Mixing to form a copper hydrate while maintaining the pH of the mixed aqueous solution in a weakly acidic to weakly alkaline range. Next, Patent Document 1 proposes a method of preparing cupric oxide by adjusting the pH to 12 to 13 and maintaining the temperature at 70 to 80 ° C. for 30 minutes, followed by washing with water and solid-liquid separation.
However, since sodium chloride (NaCl) is produced as a by-product as an impurity, there is a problem that a water washing step is necessary for removing impurities, and that it is difficult to completely remove even after washing with water. Yes.

  In Patent Document 2, a copper sulfate aqueous solution and a sodium hydroxide aqueous solution are reacted at a temperature of 30 ° C. or lower to produce cupric hydroxide, and then heated and aged at a temperature of 60 to 80 ° C. A manufacturing method for forming cupric oxide is disclosed.

Many cupric oxide powders manufactured by the wet method shown in Patent Documents 1 and 2 have excellent solubility in a copper plating solution. However, the cupric oxide powder obtained by this method has a problem that the residual concentration of S in Na and SO ₄ bodies is high as an impurity. When a copper sulfate aqueous solution of a plating solution is used, the cupric oxide powder is caused by the impurity. Problems such as plating defects were likely to occur.

  On the other hand, as described in Non-Patent Document 1, the dry method is a method in which copper nitrate, copper sulfate, copper carbonate, copper hydroxide, etc. are thermally decomposed at about 600 ° C. in the air, compared with the wet method. Productivity is high, and when metallic copper is used as a raw material, there is an advantage that high-purity cupric oxide can be obtained. However, since the thermal decomposition temperature is high in the dry method, the obtained cupric oxide powder has a problem that the dissolution rate in the plating solution is extremely slow due to the influence of sintering.

JP-A-5-31825 Japanese Patent Laid-Open No. 3-80116

4th edition experimental chemistry course inorganic compounds

  The present invention was made by paying attention to the problem of the dry method with high productivity, that is, the solubility in the plating solution. The problem is that the purity of the copper oxide is high and the solution to the plating solution is high. To provide a high-purity cupric oxide fine powder having high solubility and a method for producing the same, and to supply copper ions to an aqueous copper sulfate solution used for electroplating copper using the high-purity cupric oxide powder .

Therefore, in order to solve the above problems, as a result of continual research by the present inventors, flaky copper powder was used as a cupric oxide source, and the first oxidized heat treatment obtained at 350 ° C. or higher in an oxygen-containing atmosphere. The cupric oxide fine powder obtained by pulverizing the cupric coarse powder and subjecting the recovered primary heat-treated cupric oxide fine powder to a secondary heat treatment in an oxygen-containing atmosphere has a solubility in the plating solution. We found a phenomenon that was even higher.
The present invention has been completed based on such technical knowledge.

  1st invention of this invention uses the flaky copper powder as a raw material, The manufacturing method of the high purity cupric oxide fine powder which grind | pulverizes the cupric oxide coarse powder obtained by heat processing from the flaky copper powder A step of obtaining a cupric oxide coarse powder by primary heat treatment in an oxygen-containing atmosphere; a step of obtaining a primary heat-treated cupric oxide fine powder by pulverizing the obtained cupric oxide coarse powder; The primary heat treatment cupric oxide fine powder is subjected to a secondary heat treatment in an oxygen-containing atmosphere.

  2nd invention of this invention is a manufacturing method of the high-purity cupric oxide fine powder characterized by the processing temperature of the secondary heat processing in 1st invention being 350 to 800 degreeC.

  According to a third invention of the present invention, the primary heat treatment in the first and second inventions is characterized in that the flaky copper powder is heat-treated at a temperature of 350 ° C. to 800 ° C. in an oxygen-containing atmosphere. It is a manufacturing method of copper fine powder.

  In the fourth invention of the present invention, the heat treatment for obtaining cupric oxide coarse powder from the flaky copper powder in the first invention is carried out at a heat treatment temperature of 350 ° C. to 800 ° C. in an oxygen-containing atmosphere. It is the manufacturing method of the highly purified cupric oxide fine powder characterized by performing on conditions.

  According to a fifth aspect of the present invention, in the first to fourth aspects, the pulverization treatment is a treatment in which a slurry obtained by mixing a cupric oxide coarse powder and a solvent is pulverized using a medium stirring mill, or the second oxidation It is a process for producing a high-purity cupric oxide fine powder, characterized in that it is a treatment in which a coarse copper powder is pulverized using an airflow mill.

  6th invention of this invention is the granular cupric oxide fine powder manufactured by the manufacturing method of the highly purified cupric oxide fine powder in 1st-5th invention.

A seventh invention of the present invention is a method for supplying copper ions to an aqueous copper sulfate solution, in which a high-purity cupric oxide fine powder is dissolved to adjust the copper ion concentration of the aqueous copper sulfate solution. The cupric fine powder was obtained by the first to fifth inventions, and the high-purity cupric oxide fine powder was made of CuSO ₄ .5H ₂ O at 50 to 130 g / L, H ₂ SO ₄ Is dissolved in an aqueous solution containing 150 to 240 g / L and 30 to 70 mg / L of chlorine ions.

  The high-purity cupric oxide fine powder produced by the production method according to the present invention is suitable as a copper source for replenishing the copper plating solution because it is highly soluble in the plating solution even if produced by a dry method with high productivity. .

It is a SEM image of electrolytic copper powder. It is a SEM image of flaky copper powder. It is a SEM image of flaky copper powder.

The method for producing cupric oxide fine powder of the present invention uses flaky copper powder as a cupric oxide source, and pulverizes the cupric oxide coarse powder obtained by heat-treating the flaky copper powder. This is a method for producing high-purity cupric oxide fine powder, a step of primary heat treatment in an oxygen-containing atmosphere to obtain a cupric oxide crude powder, and a heat treatment of cupric oxide coarse powder by pulverizing the cupric oxide coarse powder. And a step of obtaining a fine powder and a step of subjecting the fine powder of the primary heat treatment cupric oxide fine powder to a secondary heat treatment in an oxygen-containing atmosphere.
Furthermore, the cupric oxide fine powder obtained by subjecting the primary heat-treated cupric oxide fine powder obtained by pulverizing the cupric oxide coarse powder obtained by such primary heat treatment to the secondary heat treatment, Compared to the primary heat-treated cupric oxide fine powder, it has a feature that the dissolution time in the aqueous copper sulfate solution is short.

Hereinafter, embodiments of the present invention will be specifically described.
[Flake copper powder]
The flaky copper powder used for the cupric oxide source is a flat copper powder and has low cohesiveness, and therefore contributes to the improvement of oxidation reactivity and solubility by heat treatment.
Regarding the form of the flaky copper powder, the particle size and thickness are small from the viewpoint of oxidation rate and are preferably thin, and large from the viewpoint of ease of handling, and are preferably thick.
From such a viewpoint, the particle size of the flaky copper powder used in the present invention is 1 to 100 μm, preferably 3 to 50 μm or less, and more preferably 5 to 30 μm. The thickness is 5 μm or less, preferably 3 μm or less, more preferably 2 μm or less.
Although what is marketed can be used for the flaky copper powder to be used, you may grind | pulverize and prepare a commercially available copper powder.

[Manufacturing method of cupric oxide fine powder]
(1) Formation of cupric oxide coarse powder The cupric oxide coarse powder is formed by performing flaky copper powder as a raw material in an oxygen-containing atmosphere under a heat treatment temperature of 350 ° C to 800 ° C. be able to.

When the heat treatment temperature is less than 350 ° C., it takes a long time for the oxidation or a heterogeneous phase is mixed.
In particular, the problem is the heterogeneous phase, and cuprous oxide among the heterogeneous phases does not dissolve in the plating solution which is an aqueous copper sulfate solution. For this reason, the presence of a different phase is considered to adversely affect the solubility of the plating solution and the properties of the plating solution.
On the other hand, the upper limit of the heat treatment temperature is preferably 800 ° C. from the viewpoint of grindability in a medium stirring mill or an airflow mill, and when the heat treatment temperature exceeds 800 ° C., the cupric oxide coarse powder is difficult to sinter and pulverize. Become. Although the atmosphere can be selected as appropriate, heat treatment may be performed in the air.

  The heat treatment time can be appropriately selected, and is appropriately selected from the presence or absence of a different phase of the cupric oxide coarse powder and the pulverizability.

(2) Grinding treatment and primary heat treatment cupric oxide powder The primary heat treatment cupric oxide fine powder is obtained by pulverizing the cupric oxide coarse powder formed from the flaky copper powder formed by the above (1). .
The powder characteristics of the bulk density, tap density, specific surface area, and average particle diameter obtained in the pulverization process here determine the powder characteristics of the subsequent secondary heat-treated cupric oxide fine powder. The secondary heat treatment described later does not sinter the primary heat-treated cupric oxide fine powder.

It is desirable to use a medium stirring mill or an airflow mill for pulverizing the cupric oxide coarse powder.
When this medium stirring mill is used, it is possible to reduce the possibility that particles having an average particle diameter determined by the equation (1) in the following paragraph [0035] exceeding 1100 nm will be formed.
The media agitation mill gives kinetic energy to the slurry containing the grinding media such as beads, the cupric oxide coarse powder and the solvent by stirring, and the collision between the cupric oxide coarse powders and the grinding media and the cupric oxide coarse powder. It is a device that obtains fine powder by shear stress.
The stirring mechanism of the medium stirring mill is not particularly limited as long as the shear stress of the beads is efficiently transmitted to the cupric oxide coarse powder.

The bead diameter as a grinding medium is generally selected according to the final particle diameter of the desired cupric oxide fine powder, but is preferably 1 mm or less in diameter. If it is 1 mm or less in diameter, the efficiency which grinds particles finely will become high.
Furthermore, the smaller the bead diameter, the faster the grinding speed and the smaller the particle diameter of the cupric oxide powder to be ground. In particular, beads having a diameter of 0.3 mm or less are particularly preferable for pulverization to a particle diameter having high solubility in the plating solution.
The material of the beads is not particularly limited, and examples thereof include glass beads having a low specific gravity, ZrO ₂ beads having a high specific gravity, and YSZ beads. Beads having a large specific gravity are particularly preferred because of high grinding efficiency and low wear.

The medium stirring mill is not particularly limited, and examples thereof include a bead mill, a ball mill, a sand mill, a paint shaker, and an ultrasonic homogenizer.
On the other hand, the airflow mill is a device that obtains fine powder by causing the cupric oxide coarse powder to collide with each other in a high-speed jet stream.
The pulverization conditions are not particularly limited regardless of whether the wet medium mill or the airflow mill is used, so that the obtained cupric oxide fine powder has a desired specific surface area and average particle diameter. What is necessary is just to select suitably.

  The solvent is not particularly limited, and examples thereof include water, ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, diacetone alcohol and other ethers, methyl ether, ethyl ether, propyl ether and other ethers, and esters. Alternatively, various organic solvents such as acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, and ketones such as isobutyl ketone can be used.

  Furthermore, depending on the intended use of the cupric oxide fine powder, a known antifoaming agent or dispersant, a compound that coats the surface of the cupric oxide fine powder, or the like may be added to the slurry as appropriate.

(3) Secondary heat treatment The primary heat-treated cupric oxide fine powder obtained through the above steps is heat-treated in an oxygen-containing atmosphere to form a secondary heat-treated cupric oxide fine powder.
The heat treatment temperature is desirably 350 ° C. to 800 ° C., and the heat treatment time is desirably 1 hour to 3 hours, but both are appropriately selected so as to finally form a complete CuO form.

The solubility of the obtained cupric oxide fine powder in the plating solution by the secondary heat treatment in the oxygen-containing atmosphere is further increased from the state of partial oxygen deficiency (CuO _1-x ). This is presumed to be in the state of CuO.
It should be noted that this secondary heat treatment does not sinter the primary heat treated cupric oxide fine powder. Therefore, the above heat treatment temperature and heat treatment time are desirable.
Furthermore, the manufacturing method of the cupric oxide fine powder according to the present invention performs the secondary heat treatment of the finely powdered primary heat treated cupric oxide fine powder obtained by pulverizing the cupric oxide coarse powder. Cheap.

The dissolution time in the copper sulfate aqueous solution is shortened by performing the secondary heat treatment.
Therefore, the cupric oxide fine powder of the present invention is more desirable as a replenishing copper source for copper plating. Specifically, the dissolution time of 7 g of the cupric oxide fine powder obtained by the production method of the present invention is 90 g / L for CuSO ₄ .5H ₂ O, 220 g / L for H ₂ SO ₄ , and chloride ions. It contains 60 mg / L and has a solubility that dissolves in 2 minutes or less when added to a stirred 1 liter aqueous copper sulfate solution.

As described above, the copper oxide fine powder obtained has a effect of secondary heat treatment, a specific surface area of ^{1m 2} / ^g~50m 2 / g, and an average particle diameter of 20nm~1100nm next, an aqueous solution of copper sulfate (Plating Solubility in the liquid). In addition, the said average particle diameter is the value calculated | required from the following (1) formula.

[Copper ion supply method for copper sulfate aqueous solution (plating solution)]
A copper plating solution (copper sulfate aqueous solution) used for electrolytic plating of copper contains copper sulfate, sulfuric acid and chlorine ions, and a pH lower than 1 is often used. A known additive is added to the copper plating solution to improve the quality of the copper plating.

  On the other hand, when copper is electroplated, copper in the plating solution is deposited, and the concentration of copper in the plating solution is lowered. Therefore, in order to prevent a decrease in the copper concentration of the plating solution, a method of performing copper electrolytic plating while dissolving the anode using copper as the anode, and an insoluble anode made of titanium or the like covered with a conductive oxide ceramic on the anode In addition, there is a method using an insoluble anode provided with a mechanism for supplying copper to the plating solution.

The problem is how to supplement copper to the plating solution when this insoluble anode is used.
To supply copper to the plating solution, the copper source such as copper or a compound containing copper dissolves rapidly in the plating solution, and the balance of SO ₄ ²⁺ ions of the plating solution is lost due to the dissolution of the copper source. Further, it is required that the additive contained in the plating solution does not decompose.
In response to such demands, cupric oxide fine powder has the advantage that the balance of SO ₄ ²⁺ ions and the like of the plating solution is not lost, and the decomposition of various additives is small.

Furthermore, it is necessary to supply the copper to the plating solution promptly whenever the copper in the plating solution decreases.
Specifically, 7 g of cupric oxide powder was added to 1 liter of an aqueous solution approximated to 90 g / L of stirred CuSO ₄ .5H ₂ O, 220 g / L of H ₂ SO ₄ , and 60 mg / L of chlorine ions. It is more desirable that the dissolution time when adding is shorter.
The cupric oxide fine powder according to the present invention dissolves within 2 minutes when introduced into 1 liter of an aqueous solution similar to the above plating solution.

Moreover, the cupric oxide fine powder thrown into the plating solution should not produce a dissolution residue. In particular, cuprous oxide should be prevented from being formed because it is not dissolved in the plating solution and becomes a residue. In the manufacturing method of cupric oxide fine powder of the present invention, cuprous oxide which becomes a different phase by heat treatment at the time of manufacturing cupric oxide coarse powder is hard to occur.
Further, under the heat treatment conditions, a cupric oxide crude powder that can be made fine by a medium agitating mill or an airflow mill is obtained. A fine copper powder will be obtained. Therefore, it is possible to adjust the plating solution, that is, supply copper ions to the aqueous copper sulfate solution.

In order to carry out the method of supplying copper ions to the aqueous copper sulfate solution of the present invention in an electrolytic plating apparatus, a cupric oxide dissolution tank that dissolves cupric oxide fine powder separately from the plating tank for plating of the electrolytic plating apparatus And an aqueous solution (plating solution) may be circulated between the plating tank and the cupric oxide dissolution tank.
This cupric oxide dissolution tank returns an aqueous solution formed by dissolving cupric oxide fine powder in the aqueous solution supplied from the plating tank to the plating tank. It is preferable to attach a stirring mechanism such as a propeller to the cupric oxide dissolution tank to be used. Moreover, you may provide a well-known various filter between a plating tank and a cupric oxide dissolution tank for removal of a dust, a foreign material, etc.
The copper sulfate aqueous solution used in the method for supplying copper ions to the copper sulfate aqueous solution of the present invention may be an aqueous solution in which copper sulfate is dissolved in water, or the cupric oxide fine powder according to the present invention is dissolved in sulfuric acid. An aqueous solution may be used.

Examples of the present invention will be specifically described below together with comparative examples. However, the present invention is not limited to the following examples.
Among the obtained cupric oxide crude powder, all the samples in which the CuO single phase was confirmed by X-ray diffraction measurement (XRD) were black.

(Preparation of flaky copper powder)
Electrolytic copper powder (Grade: MF-D2, see FIG. 1) manufactured by Mitsui Kinzoku Co., Ltd. was weighed to 20 wt% and water 80 wt%, and 0.3 mmφZrO ₂ beads (Tracelum manufactured by Toray Industries, Inc.) ) For 12 hours with a paint shaker (made by Asada Iron Works Co., Ltd.), and then the bead-separated liquid was dried at 105 ° C. to obtain flaky copper powder.

The SEM image of the flaky copper powder after drying is shown in FIGS. The particle diameter and thickness were measured from this SEM image.
The particle diameter was measured by defining the major axis and the minor axis by regarding the particle as an ellipse.
As a result, the particle diameter was 5 to 30 μm. Here, the minimum value of the particle diameter is the minimum value of the short diameter, and the maximum value of the particle diameter is the maximum value of the long diameter. The thickness was 0.1 to 2.0 μm.

(Preparation of cupric oxide coarse powder by primary heat treatment)
A cupric oxide coarse powder a was obtained by heat-treating 10 g of this flaky copper powder at a temperature of 500 ° C. for 3 hours (primary heat treatment) in an air atmosphere.

(Preparation of primary heat-treated cupric oxide fine powder by grinding)
Next, the prepared cupric oxide coarse powder a 20% by weight, were weighed rest so water is 80 wt%, and 2 hours milling in a paint shaker containing the ZrO ₂ beads with a diameter of 0.3mm Thereafter, the dispersion from which the beads were separated was dried at 105 ° C. to obtain a primary heat-treated cupric oxide fine powder a.

(Preparation of cupric oxide fine powder by secondary heat treatment)
Thereafter, the cupric oxide fine powder a was formed by subjecting the primary heat-treated cupric oxide fine powder a to a secondary heat treatment at a temperature of 500 ° C. for 3 hours in an air atmosphere.
The cupric oxide fine powder a was a CuO single phase as a result of powder X-ray analysis.

(Evaluation of solubility of cupric oxide fine powder)
Next, as the plating solution composition, CuSO ₄ · 5H ₂ O: 68 g / L, H ₂ SO ₄ : 228 g / L, Cl ion: 60 mg / L, and while stirring with a stirrer at room temperature, When 7 g of cupric oxide fine powder a was added, it dissolved in 12 seconds.

In Example 1, the cupric oxide according to Example 2 was performed in the same manner as in Example 1 except that the primary heat treatment temperature when forming the cupric oxide coarse powder from the flake-shaped copper powder was 400 ° C. A fine powder b was formed.
The cupric oxide fine powder b was a CuO single phase as a result of powder X-ray analysis.
Next, when a dissolution test in the plating solution was performed in the same manner as in Example 1, it was dissolved in 18 seconds.

In Example 1, the second heat treatment according to Example 3 was performed in the same manner as in Example 1 except that the temperature of the primary heat treatment when forming the cupric oxide coarse powder from the flake-shaped copper powder was set to 700 ° C. Copper fine powder c was formed.
The cupric oxide fine powder c was a CuO single phase as a result of powder X-ray analysis.
Next, when a dissolution test in the plating solution was performed in the same manner as in Example 1, it was dissolved in 36 seconds.

In Example 1, the cupric oxide fine powder d according to Example 4 was prepared in the same manner as in Example 1 except that the heat treatment temperature during the secondary heat treatment of the primary heat treated cupric oxide fine powder was 600 ° C. Formed. As a result of the powder X-ray analysis of the cupric oxide fine powder d, it was a CuO single phase.
Next, when a dissolution test in a plating solution was performed in the same manner as in Example 1, it was dissolved in 25 seconds.

(Comparative Example 1)
Example 1 is the same as Example 1 except that the temperature of the primary heat treatment when forming cupric oxide coarse powder from the flake-shaped copper powder is 300 ° C. and the temperature of the secondary heat treatment is 600 ° C. Thus, cupric oxide fine powder e according to Comparative Example 1 was formed.
As a result of powder X-ray analysis, Cu cuprate fine powder e was not subjected to a dissolution test in a plating solution because Cu was mixed in addition to CuO.

(Comparative Example 2)
In Example 1, the second oxide according to Comparative Example 2 was made in the same manner as in Example 1 except that the temperature of the primary heat treatment when forming the cupric oxide coarse powder from the flake-shaped copper powder was set to 900 ° C. Copper fine powder f was formed.
Next, when a dissolution test in a plating solution was performed in the same manner as in Example 1, it took 15 minutes or more for dissolution.

(Comparative Example 3)
In Example 1, the Mitsui Metals electrolytic copper powder (Grade: MF-D2) was not made into flakes, and the paint shaker was pulverized after being heat-treated at 500 ° C. for 3 hours in the atmosphere and at 500 ° C. for 3 hours in the atmosphere. A cupric oxide fine powder g according to Comparative Example 3 was formed in the same manner as in Example 1 except that the secondary heat treatment was not performed.
Next, when a dissolution test in a plating solution was performed in the same manner as in Example 1, it took 15 minutes or more for dissolution.

(Comparative Example 4)
In Example 1, the cupric oxide fine powder h according to Comparative Example 4 was obtained in the same manner as in Example 1 except that the secondary heat treatment after pulverizing the cupric oxide coarse powder with a paint shaker for 2 hours was not performed. Formed.
Next, when a dissolution test in a plating solution was performed in the same manner as in Example 1, it took 6 minutes for dissolution.

(Comparative Example 5)
In Example 1, cupric oxide fine powder i according to Comparative Example 5 was formed in the same manner as Example 1 except that the cupric oxide coarse powder was not subjected to paint shaker pulverization and subsequent secondary heat treatment. .
Next, when a dissolution test in a plating solution was performed in the same manner as in Example 1, it took 15 minutes or more for dissolution.

(Comparative Example 6)
In Example 1, the electrolytic copper powder made by Mitsui Kinzoku Co., Ltd. was not made into a flake shape, and the grinding time in the paint shaker in the preparation of the primary heat-treated cupric oxide fine powder by the grinding treatment was 12 hours. In the same manner as in Example 1, cupric oxide fine powder j according to Comparative Example 6 was formed.
Next, when a dissolution test in a plating solution was performed in the same manner as in Example 1, it was dissolved in 12 seconds.

The results of Examples 1 to 4 and Comparative Examples 1 to 6 are summarized in Table 1 above.
As is clear from Table 1, in Examples 1 to 4 which are cupric oxide fine powders produced by the production method of the present invention, it dissolves in a copper sulfate aqueous solution as a plating solution within 1 minute and is easily soluble. I understand that. On the other hand, it is clear that Comparative Examples 1 to 5 in which any of the manufacturing conditions are not satisfied do not satisfy the solubility in the plating solution. Moreover, although Comparative Example 6 is satisfactory in solubility in the plating solution, it can be seen that the pulverization time is long and the pulverization efficiency is poor.

Claims (7)

Using a flaky copper powder as a raw material, a method for producing a high-purity cupric oxide fine powder that pulverizes a cupric oxide coarse powder obtained by heat treatment from the flaky copper powder,
A step of primary heat treatment in an oxygen-containing atmosphere to obtain a cupric oxide crude powder;
Crushing the cupric oxide coarse powder to obtain a primary heat treated cupric oxide fine powder;
Performing the secondary heat treatment of the primary heat-treated cupric oxide fine powder in an oxygen-containing atmosphere;
The manufacturing method of the highly purified cupric oxide fine powder characterized by comprising.   The process temperature of the said secondary heat processing is 350 to 800 degreeC, The manufacturing method of the highly purified cupric oxide fine powder of Claim 1 characterized by the above-mentioned.   The said primary heat processing heat-processes flake shaped copper powder at the temperature of 350 to 800 degreeC by oxygen-containing atmosphere, The manufacturing method of the high purity cupric oxide fine powder of Claim 1 or 2 characterized by the above-mentioned.   The method for producing a high-purity cupric oxide fine powder according to claim 1, wherein the heat treatment is a heat treatment of the flaky copper powder in an oxygen-containing atmosphere at a maximum temperature of 350 ° C to 800 ° C. .   The pulverization treatment is a slurry obtained by mixing the cupric oxide coarse powder and the solvent, a pulverization treatment using a medium stirring mill, or a pulverization treatment of the cupric oxide coarse powder using an airflow mill. The manufacturing method of the highly purified cupric oxide fine powder of Claim 1 to 4 characterized by these. Granular cupric oxide fine powder,
A granular cupric oxide fine powder produced by the method for producing a high-purity cupric oxide fine powder according to any one of claims 1 to 5. A method for supplying copper ions to an aqueous copper sulfate solution, wherein high-purity cupric oxide fine powder is dissolved to adjust the copper ion concentration of the aqueous copper sulfate solution,
The high-purity cupric oxide fine powder is obtained by the method for producing a high-purity cupric oxide fine powder according to claim 1,
The high-purity cupric oxide fine powder is dissolved in an aqueous solution containing 50 to 130 g / L of CuSO ₄ .5H ₂ O, 150 to 240 g / L of H ₂ SO _4, and 30 to 70 mg / L of chlorine ions. A method for supplying copper ions to an aqueous copper sulfate solution.