Amorphous copper material for electrolytic copper foil and method for manufacturing the same

Abstract

The present invention relates to a non-shape copper material for electrolytic copper foil and a method for manufacturing the same. In particular, the present invention relates to a non-shape copper material for electrolytic copper foil and a method for manufacturing the same, which not only has excellent dissolving performance when dissolved in an electrolyte solution for manufacturing electrolytic copper foil, but also ensures work stability when manufacturing electrolytic copper foil, and has a simple manufacturing process, thereby enabling cost reduction.

Description

Technical Field

[0001] This invention relates to indeterminate copper materials for electrolytic copper foil and their manufacturing method. Specifically, the invention relates to indeterminate copper materials for electrolytic copper foil and their manufacturing method, wherein the indeterminate copper materials not only exhibit excellent solubility in the electrolyte used to manufacture electrolytic copper foil, but also ensure operational stability during the manufacturing of electrolytic copper foil, and the manufacturing process is simple, thereby reducing costs. Background Technology

[0002] Electrolytic copper foil is manufactured by a continuous plating process in which a large titanium drum, acting as the cathode, is slowly rotated in an electrolyte, such as a copper sulfate solution, and copper is deposited in the form of copper foil. It is used for copper-plated laminates for printed circuit boards or building materials, especially for cathode plates of secondary batteries.

[0003] Figure 1 This is a flowchart of the raw material manufacturing process for existing linear copper materials used in electrolytic copper foil. Figure 2 These are photographs showing the shape and microstructure of cut copper wires produced during the manufacturing process of existing linear copper materials for electrolytic copper foil.

[0004] like Figure 1 As shown, the linear copper material for electrolytic copper foil can be manufactured by a method including a raw material supply step such as electrolytic copper (copper cathode) or copper scrap; a step of manufacturing the raw material into wire by casting, casting + rolling, or casting + rolling + wire drawing; and a step of cleaning and cutting the manufactured wire. On the other hand, electrolytic copper foil can be manufactured by dissolving the cut linear copper material, which is the raw material for electrolytic copper foil, in a sulfuric acid solution, which is the electrolyte.

[0005] In existing methods for manufacturing electrolytic copper foil, raw materials used for electrolytic copper foil include... Figure 2 The linear copper material shown is a cut copper wire. The cut linear copper material is manufactured through rolling, drawing and cutting processes. During rolling and drawing, it is exposed to oil components such as rolling oil and drawing oil, so it must be cleaned for degreasing, which makes the process complicated and increases the cost of electrolytic copper foil.

[0006] In addition, the cut wire copper material is usually manufactured into a shape with a diameter of 2 to 4 mm and a length of 30 to 100 mm to improve its solubility relative to the electrolyte. In this case, the problem is that during the electrolyte dissolution process, the cut wire copper material falls from the bottom of the plate with a 10 mm diameter hole, which is set at the bottom of the dissolution tank for electrolyte circulation and air supply, resulting in reduced workability.

[0007] In addition, the linear copper material undergoes continuous casting, rolling, and wire drawing processes, and is as follows: Figure 2 As shown, the average grain size of 5 μm is achieved through grain refinement. The higher grain boundary density accelerates the oxidation (passivity) of the linear copper surface, resulting in reduced solubility relative to the electrolyte.

[0008] Therefore, there is an urgent need for copper materials and manufacturing methods that not only have excellent solubility in the electrolyte used to manufacture electrolytic copper foil, but also ensure operational stability and have a simple manufacturing process, thereby reducing costs. Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The purpose of this invention is to provide an amorphous copper material with excellent solubility when dissolved in an electrolyte used to manufacture electrolytic copper foil, and a method for manufacturing the same.

[0011] In addition, the present invention aims to provide an amorphous copper material and its manufacturing method that can ensure operational stability during the manufacture of electrolytic copper foil, have a simple manufacturing process, and thus reduce the cost of electrolytic copper foil.

[0012] Technical solutions to the problem

[0013] To address the aforementioned problems, the present invention provides an amorphous copper material for electrolytic copper foil, wherein the average grain size of the amorphous copper material for electrolytic copper foil is 50 to 300 μm.

[0014] Here, a bulk density of 1.0 to 3.0 g / cm³ is provided, defined by the following mathematical formula 1. 3 Amorphous copper material for electrolytic copper foil.

[0015] [Mathematical Expression 1]

[0016] Bulk density (g / cm³) 3 = Total mass of amorphous copper material (g) / 1000cm³ 3

[0017] The total mass of the amorphous copper material refers to the total mass of the amorphous copper material filled in a cubic box with a length × width × height of 10cm × 10cm × 10cm.

[0018] In addition, an amorphous copper material for electrolytic copper foil is provided, wherein the longest axis of the amorphous copper material in any cross section is 10 mm or more, and the shortest axis of the short axis in any cross section is 5 mm or less.

[0019] In addition, an amorphous copper material for electrolytic copper foil is provided, characterized in that the longest axis is 10 to 75 mm and the shortest axis is 1 to 5 mm.

[0020] On the other hand, a method for manufacturing the amorphous copper material for electrolytic copper foil is provided, comprising: a) a copper raw material supply step; b) a copper raw material melting step; and c) a step of manufacturing the amorphous copper material by casting after melting the copper raw material.

[0021] Hereinafter, a method for manufacturing the amorphous copper material for electrolytic copper foil is provided, characterized in that, in step c), molten copper from the copper raw material is dispersed in the form of microparticles, settled into water in a water tank and cooled, thereby manufacturing the amorphous copper material.

[0022] In addition, a method for manufacturing the amorphous copper material for electrolytic copper foil is provided, characterized in that, in step c), molten copper from the copper raw material is dispersed in particulate form by dropping it from a molten metal nozzle onto an impact plate disposed on a water tank containing water, and then settles into the water in the water tank and is cooled, thereby manufacturing the amorphous copper material.

[0023] Furthermore, a method for manufacturing the amorphous copper material for electrolytic copper foil is provided, characterized in that the molten copper has a molten metal temperature of 1,090 to 1,400°C.

[0024] In addition, a method for manufacturing the amorphous copper material for electrolytic copper foil is provided, characterized in that the distance between the outlet of the molten metal nozzle and the upper surface of the impact plate is 0.3 to 1.5 m.

[0025] In addition, a method for manufacturing the amorphous copper material for electrolytic copper foil is provided, characterized in that the oxygen content of the molten copper is 20 to 1,000 ppm.

[0026] Invention Effects

[0027] The amorphous copper material for electrolytic copper foil involved in this invention exhibits excellent solubility performance, such as rapid dissolution rate and high solubility content, through specific bulk density, grain size and specific shape when dissolved in electrolyte.

[0028] In addition, the amorphous copper material for electrolytic copper foil involved in this invention exhibits the following excellent effects: it ensures operational stability during the manufacture of electrolytic copper foil, and unlike linear copper materials, it simplifies the manufacturing process because it does not require rolling, drawing, cleaning for degreasing, cutting, or other processes, thereby reducing the cost of electrolytic copper foil. Attached Figure Description

[0029] Figure 1 This is a flowchart of the existing manufacturing process for linear copper materials used in electrolytic copper foil.

[0030] Figure 2 These are photographs of the morphology and microstructure of linear copper materials used in existing electrolytic copper foil.

[0031] Figure 3 This is a flowchart of the manufacturing process of the amorphous copper material for electrolytic copper foil involved in this invention.

[0032] Figure 4 It is based on Figure 3 The photographs show the shape and microstructure of the amorphous copper material manufactured using the manufacturing process.

[0033] Figure 5 It is shown in general terms. Figure 3 A diagram showing the state of the casting apparatus used in the manufacturing process of amorphous copper materials for electrolytic copper foil.

[0034] Figure 6 This is a diagram showing the shape of a cube-shaped acrylic box filled with copper material for measuring bulk density. Detailed Implementation

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein, and may be embodied in other forms. Rather, the embodiments described herein are provided to make the disclosure thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art.

[0036] Figure 3 This is a flowchart of the manufacturing process of the amorphous copper material for electrolytic copper foil involved in this invention. Figure 4 It is based on Figure 3 The photographs show the shape and microstructure of the amorphous copper material manufactured using the manufacturing process. Figure 5 It is shown in general terms. Figure 3A diagram showing the state of the casting equipment used in the manufacture of amorphous copper materials for electrolytic copper foil. Additionally, Figure 6 This is a diagram showing the shape of a cube-shaped acrylic box filled with copper material for measuring bulk density.

[0037] like Figure 3 As shown, the amorphous copper material for electrolytic copper foil can be manufactured by a manufacturing method including the following steps a) to c).

[0038] a) Raw material supply steps such as electrolytic copper cathode or scrap;

[0039] b) The steps of supplying raw materials in a melt-melted manner; and

[0040] c) The step of manufacturing unshaped copper material by casting after melting raw materials.

[0041] Step c) can utilize Figure 5 The casting apparatus shown is used to perform this process. Figure 5 As shown, after refining, copper molten at 1,090°C or higher, preferably 1,090 to 1,400°C, falls from a molten metal nozzle onto an impact plate set on a water tank. When the falling molten copper impacts the impact plate, it is impacted and dispersed in all directions in the form of amorphous particles without a specific shape. It settles into the water in the water tank and is cooled, thereby forming an amorphous copper material.

[0042] Here, when the molten metal temperature of the molten copper is below 1,090°C, there may be problems such as the molten metal solidifying prematurely, the outlet of the molten metal nozzle being blocked, or the copper falling onto the impact plate being fused to the impact plate. On the other hand, when the molten metal temperature exceeds 1,400°C, there is a problem that the molten copper in the form of particles that are dispersed in all directions by falling onto the impact plate may be fused again, resulting in copper material with an excessively coarse shape.

[0043] In addition, the size of the generated amorphous copper material can be adjusted by adjusting the distance between the outlet of the molten metal nozzle that discharges molten copper from the lower part of the molten metal tank containing the molten copper and the upper surface of the impact plate to 0.3 to 1.5 m.

[0044] Here, when the distance between the outlet of the molten metal nozzle and the upper surface of the impact plate is less than 0.3m, the molten copper cannot be fully dispersed from the impact plate and may form excessively coarse amorphous copper material. On the other hand, when the distance exceeds 1.5m, the molten copper dispersed from the impact plate is dispersed in an excessively fine shape, thereby causing the formation of excessively fine amorphous copper material.

[0045] Furthermore, the oxygen content of the molten metal in the molten copper can be adjusted to between 20 and 1,000 ppm. Here, when the oxygen content of the molten metal is below 20 ppm, there is a problem that a large amount of hydrogen gas flows into the molten metal, making it difficult to control the shape of the amorphous copper material formed from the scattered molten copper. On the other hand, when the oxygen content exceeds 1,000 ppm, there is a problem that a large amount of oxides are generated when the amorphous copper material is solidified by cooling, making it difficult to control the shape of the amorphous copper material.

[0046] The amorphous copper material for electrolytic copper foil of the present invention, manufactured according to the embodiments of the manufacturing method shown above, refers to a copper material with an amorphous shape that cannot be defined as a specific shape such as a line or a circle.

[0047] On the other hand, electrolytic copper foil can be manufactured by dissolving the amorphous copper material produced as described above in a sulfuric acid electrolyte. As mentioned above, unlike existing linear copper materials, the amorphous copper material does not require rolling, drawing, or cutting processes during manufacturing. In particular, it does not use the rolling oil and drawing oil used in rolling and drawing, and therefore does not require a cleaning process for degreasing, which greatly simplifies the manufacturing process and can significantly reduce the manufacturing cost of electrolytic copper foil.

[0048] Here, as Figure 4 As shown, the amorphous copper material has an average grain size of 50 to 300 μm, preferably 150 to 250 μm, which is relatively coarse. It has a low grain boundary density, which delays surface passivation and thus ensures sufficient solubility relative to the electrolyte.

[0049] On the contrary, such as Figure 2 The existing linear copper material shown has a high grain boundary density when the average grain size is less than 50 μm and is therefore fine, which accelerates the passivation of the surface and results in a decrease in solubility relative to the electrolyte.

[0050] The coarse grain size of the amorphous copper material does not undergo the rolling and wire drawing processes found in existing linear copper materials, such as... Figure 5 As shown, this is achieved by rapidly cooling molten copper in water.

[0051] Here, the average grain size can be measured by inputting microscopic images of the amorphous and linear copper materials taken with an optical or electron microscope into general-purpose software such as an image analyzer. The average grain size can be measured using various methods known to those skilled in the art.

[0052] In addition, the amorphous copper material can be as follows: Figure 4The amorphous particle morphology shown has no specific shape and its bulk density can range from 1.0 to 3.0 g / cm³. 3 The inventors of this invention completed the invention by experimentally confirming that the amorphous copper material produced had a predetermined grain size, preferably a predetermined bulk density, and thus improved its solubility properties, such as rapid dissolution rate and high solubility in electrolyte.

[0053] Here, the bulk density can refer to the total mass of copper material relative to the volume of a cube with a length × width × height of 10cm × 10cm × 10cm, and can be defined by the following mathematical formula 1.

[0054] [Mathematical Expression 1]

[0055] Bulk density (g / cm³) 3 = Total mass of copper material (g) / 1000cm 3

[0056] The total mass of copper material refers to the total mass of copper material filled inside a cubic box with dimensions of 10cm x 10cm x 10cm.

[0057] The total mass of the copper material can be calculated by dropping it 5cm from the top of a cubic acrylic box with dimensions of 10×10×10cm (length×width×height) into the interior of the box, ensuring that the lid of the cubic acrylic box can be completely closed and the copper material at the top of the box is fully filled. The length, width, and height of the cubic acrylic box are based on the internal dimensions. In this embodiment, a 5mm thick acrylic box is used; however, the material and thickness of the box are not particularly limited, as long as the cubic shape is maintained.

[0058] In particular, the bulk density of the amorphous copper material is less than 1.0 g / cm³. 3 In this case, although the surface area of ​​the amorphous copper material in contact with the electrolyte increases, there is actually a problem of insufficient copper content dissolved in the electrolyte. On the other hand, when the bulk density exceeds 3.0 g / cm³... 3 In some cases, although the amount of copper dissolved in the electrolyte is sufficient, the surface area of ​​the amorphous copper material in contact with the electrolyte is insufficient, which may significantly reduce the dissolution rate.

[0059] In addition, the longest axis of the irregular copper material in any cross section can be more than 10 mm, preferably 10 to 75 mm, and the shortest axis of the short axis in any cross section can be less than 5 mm, preferably 1 to 5 mm.

[0060] When the longest axis is less than 10 mm, during the electrolyte dissolution process, copper material may fall from the bottom of the plate with 10 mm diameter perforations located at the bottom of the electrolyte tank for electrolyte circulation and air supply, potentially causing reduced workability. On the other hand, when the longest axis exceeds 75 mm, the dissolution performance relative to the electrolyte may be significantly reduced due to insufficient specific surface area of ​​the copper material. Conversely, when the shortest axis exceeds 5 mm, the dissolution performance relative to the electrolyte may be significantly reduced due to insufficient specific surface area of ​​the copper material.

[0061] Here, the longest and shortest axes of the amorphous copper material can be measured using a mechanism such as vernier calipers, but there are no particular limitations, as long as the mechanism is capable of measuring length.

[0062] [Example]

[0063] 1. Examples of copper material manufacturing

[0064] use Figure 5 The casting apparatus shown manufactures amorphous copper materials corresponding to Examples 1 to 3, which have the characteristics described in Table 1 below, by adjusting the molten metal temperature of the molten copper and the distance from the outlet of the molten metal nozzle that ejects the molten copper to the impact plate.

[0065] In addition, for comparison with the above embodiments, linear copper materials corresponding to Comparative Examples 1 to 3 were manufactured by casting, rolling, drawing, cleaning and cutting copper raw materials.

[0066] [Table 1]

[0067]

[0068] 2. Evaluation of the solubility of copper materials

[0069] The copper materials from the examples and comparative examples were precipitated in a 1L sulfuric acid solution at 80°C and a concentration of 150g / L for 48 hours. The weight of each sample was then measured, the amount dissolved was calculated, and recorded in Table 2 below.

[0070] [Table 2]

[0071]

[0072] As shown in Table 2, the dissolution performance of the amorphous copper materials of Examples 1 to 3, which precisely adjusted the bulk density while having a predetermined level of grain size and a specific shape, was significantly improved, including the dissolution rate and the amount of dissolution.

[0073] On the other hand, it was confirmed that the existing linear copper materials of Comparative Examples 1 to 3 had excessive bulk density and insufficient surface area in contact with the electrolyte, resulting in a significant decrease in dissolution rate. Furthermore, the average grain size was small and the grain boundary density was high, which accelerated surface passivation and reduced the dissolution performance relative to the electrolyte.

[0074] This specification has been described with reference to preferred embodiments of the invention; however, those skilled in the art can modify and vary the invention in various ways without departing from the spirit and scope of the invention as set forth in the following claims. Therefore, any modifications that substantially include the elements within the scope of the claims should be considered to be entirely included within the technical scope of the invention.

Claims

1. An amorphous copper material for electrolytic copper foil, wherein, the average grain size of the amorphous copper material for electrolytic copper foil is 50 to 300 μm, The bulk density defined by the following mathematical formula 1 is 1.0 to 3.0 g / cm 3 , Mathematical formula 1 Bulk density (g / cm 3 ) = Total mass of the amorphous copper material (g) / 1000 cm 3 wherein the total mass of the amorphous copper material is calculated by dropping the amorphous copper material at a height of 5 cm from the uppermost end of a cubic acrylic box having a size of 10 x 10 x 10 cm in length x width x height, to the inside of the cubic acrylic box, and filling the inside of the cubic acrylic box to the uppermost end to the extent that the lid of the cubic acrylic box can be completely closed.

2. The amorphous copper material for electrolytic copper foil according to claim 1, wherein, the longest axis, which is the longest axis among the longest axes in the major axes on any cross section, of the amorphous copper material is 10 mm or more, and the shortest axis, which is the shortest axis among the shortest axes in the minor axes on any cross section, is 5 mm or less.

3. The amorphous copper material for electrolytic copper foil according to claim 2, characterized in that, the longest axis is 10 to 75 mm, and the shortest axis is 1 to 5 mm.

4. A method for producing a bulk copper material for electrolytic copper foil as claimed in any one of claims 1 to 3, wherein including: a) a copper raw material supply step; b) a melting step of the copper raw material; and c) a step of manufacturing an amorphous copper material by casting after melting the copper raw material to make molten copper.

5. The method of manufacturing the amorphous copper material for electrolytic copper foil according to any one of claims 1 to 3 according to claim 4, characterized in that, in the step c), the molten copper from the copper raw material is dispersed in a particulate form, settled into water installed in a water tank, and cooled to thereby manufacture an amorphous copper material.

6. The method of manufacturing the amorphous copper material for electrolytic copper foil according to any one of claims 1 to 3 according to claim 5, characterized in that, in the step c), the molten copper from the copper raw material is dispersed in a particulate form by dropping from a molten metal nozzle onto an impact plate provided on a water tank installed with water, settled into water installed in the water tank, and cooled to thereby manufacture an amorphous copper material.

7. The method of manufacturing the amorphous copper material for electrolytic copper foil according to any one of claims 1 to 3 according to claim 4, characterized in that, the molten metal temperature of the molten copper is 1,090 to 1,400 °C.

8. The method of manufacturing the amorphous copper material for electrolytic copper foil according to any one of claims 1 to 3 according to claim 6, characterized in that, the distance between the discharge port of the molten metal nozzle and the upper face of the impact plate is 0.3 to 1.5 m.

9. The method of manufacturing the amorphous copper material for electrolytic copper foil according to any one of claims 1 to 3 according to claim 4, characterized in that, the oxygen content of the molten copper is 20 to 1,000 ppm.

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