Titanium anode plate suitable for HVLP copper foil production and preparation method thereof

Abstract

This invention discloses a method for preparing a titanium anode plate suitable for HVLP copper foil production, comprising the following steps: titanium substrate pretreatment: mechanically grinding and acid etching are performed on the titanium substrate sequentially to form a micro-rough surface; an electroplating solution is prepared, the electroplating solution including a noble metal compound, with a pH value of 1-3; electrodeposition: in the electroplating solution, using the titanium substrate as the anode and the titanium plate as the cathode, a stepped DC voltage sequence is applied using a programmable power supply, each stage lasting 1-10 minutes, and the current density is kept constant throughout the process, forming a composite coating on the surface of the titanium substrate, wherein the stepped DC voltage sequence starts with a low voltage; the electrodeposited titanium plate is then dried and heat-treated sequentially to transform the coating into a composite metal oxide; the above steps are repeated until the noble metal loading in the coating reaches the target value. The method for preparing the titanium anode plate of this invention can form a uniform, dense, crack-free, and strongly bonded noble metal oxide coating on a titanium substrate. This invention also provides a titanium anode plate prepared by this method suitable for HVLP copper foil production.

Description

Technical Field

[0001] This invention relates to the field of electrochemical electrode materials technology, specifically to a titanium anode plate suitable for HVLP copper foil production and its preparation method. Background Technology

[0002] In the production of electrolytic copper foil, especially HVLP (High Volume Low Profile) copper foil, which has extremely high requirements for surface microstructure, the performance of the titanium anode (DSA) is crucial. The catalytic activity, stability, and uniformity of the anode surface directly determine the uniformity, mechanical properties, and surface profile of the copper foil deposition.

[0003] Traditional titanium anode preparation often employs brush coating or dip coating combined with thermal decomposition. While these methods are widely used, they suffer from poor coating uniformity control, high internal stress, and susceptibility to microcracks, potentially leading to localized coating failure, electrolyte contamination, and copper foil quality fluctuations under long-term high current density operation. Furthermore, some studies have used electroplating (electrodeposition) techniques to improve coating adhesion; however, improper process parameter control can result in overly rapid reactions leading to porous coatings or uneven dissolution of the passivation film, ultimately shortening anode life.

[0004] Therefore, there is an urgent need in the field for a new method to prepare titanium anodes with higher density, stronger bonding and longer service life to meet the stringent requirements of HVLP copper foil production. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a titanium anode plate suitable for HVLP copper foil production and its preparation method. By controlling the step voltage sequence of the electrocoating process, a uniform, dense, crack-free and strongly bonded noble metal oxide coating is formed on the titanium substrate, which can significantly improve the durability and electrochemical stability of the anode in the HVLP copper foil production environment.

[0006] The first aspect of this invention is to provide a method for preparing a titanium anode plate suitable for HVLP copper foil production, the technical solution of which is:

[0007] A method for preparing a titanium anode plate suitable for HVLP copper foil production includes the following steps:

[0008] Step S1, titanium substrate pretreatment: The titanium substrate is mechanically polished and acid-etched in sequence to form a micro-rough surface on its surface;

[0009] Step S2: Prepare an electroplating solution, wherein the electroplating solution includes a noble metal compound and has a pH value of 1-3;

[0010] Step S3, Electrodeposition: In the electroplating solution, using the titanium substrate as the anode and the titanium plate as the cathode, a stepped DC voltage sequence is applied using a programmable power supply. The stepped DC voltage sequence first deposits at 2V for 1 min, then at 4V for 10 min, and the current density is kept constant at 5 mA / cm² throughout the process. 2 A composite coating is formed on the surface of the titanium substrate;

[0011] Step S4: The electrodeposited titanium plate is dried and heat-treated sequentially to transform the coating into a composite metal oxide.

[0012] Step S5: Repeat steps S3-S4 until the noble metal loading in the coating reaches the target value.

[0013] Preferably, in step S1, mechanical sandblasting is performed until the surface roughness Ra reaches 13-16μm and Rz reaches 75-90μm.

[0014] Preferably, the acid etching process is as follows: using a mixed solution of 8-10wt% oxalic acid and 5-7wt% hydrochloric acid, and treating at 75-95℃ for 2-5 hours.

[0015] Preferably, in step S2, the electroplating solution comprises the following components:

[0016] Iridium-containing compounds at concentrations of 0.3–0.5 mol / L, tantalum-containing compounds at concentrations of 0.1–0.2 mol / L, and tin-containing compounds at concentrations of 0.02–0.05 mol / L;

[0017] The electroplating solution is prepared by mixing the iridium-containing compound, the tantalum-containing compound, and the tin-containing compound in a volume ratio of 6:3:1.

[0018] Preferably, in step S3, the distance between the cathode and the anode is 10-15 mm, and the cathode and the anode have the same area.

[0019] Preferably, in step S3, the electroplating solution is heated by a water bath at a temperature of 50-70℃ and is stirred by electromagnetic stirring at a speed of 150-300 rpm.

[0020] Preferably, in step S4, the drying temperature is 110-130℃ and the time is 5-10 min; the heat treatment is carried out in an air atmosphere at 400-500℃ for 15-30 min.

[0021] Preferably, steps S3-S4 are repeated until the amount of iridium oxide in the coating is 15-20 g / m² and the amount of tantalum oxide is 8-10 g / m².

[0022] A second aspect of the present invention is to provide a titanium anode plate suitable for the production of HVLP copper foil, which is prepared by the method of the first aspect.

[0023] Compared with the prior art, the titanium anode plate and its preparation method suitable for HVLP copper foil production provided by the present invention have the following advantages:

[0024] The method for preparing titanium anode plates suitable for HVLP copper foil production provided by the present invention uses a stepped DC voltage sequence for electrodeposition to achieve layer-by-layer, controllable growth of the coating on the titanium substrate, effectively releasing internal stress and avoiding cracking and peeling problems caused by high-voltage one-time impact, thereby obtaining a denser and more uniform coating microstructure.

[0025] II. The method for preparing titanium anode plates suitable for HVLP copper foil production provided by this invention promotes a strong bond between the coating and the titanium substrate at the interface. Enhanced lifespan test results show that the titanium anode plates prepared by this invention have a lifespan that is more than 17% longer than anode plates prepared by conventional processes at extremely high current densities of 40,000 A / m², demonstrating excellent durability.

[0026] Third, the method for preparing titanium anode plates suitable for HVLP copper foil production provided by the present invention can obtain a dense and crack-free coating structure, which makes the titanium anode plate have a lower initial voltage and a more stable cell voltage during use, which is beneficial to reduce energy consumption and ensure the extreme uniformity of the electrolysis process, especially the HVLP copper foil deposition process, effectively improving the product yield of high-end copper foil.

[0027] IV. The method for preparing titanium anode plates suitable for HVLP copper foil production provided by this invention has good repeatability and has the potential for large-scale industrial application. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a microstructure diagram of the coating obtained using the preparation method of the present invention;

[0030] Figure 2 This is a microstructure diagram of the coating in Comparative Example 1;

[0031] Figure 3 This is a microstructure diagram of the coating in Comparative Example 2;

[0032] Figure 4This is a comparison chart of the cross-cut test results of Example 1, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described below.

[0034] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0035] The first aspect of this invention is to provide a method for preparing a titanium anode plate suitable for HVLP copper foil production, the technical solution of which is:

[0036] A method for preparing a titanium anode plate suitable for HVLP copper foil production includes the following steps:

[0037] Step S1, titanium substrate pretreatment: The titanium substrate is mechanically polished and acid-etched in sequence to form a micro-rough surface on its surface;

[0038] Step S2: Prepare an electroplating solution, wherein the electroplating solution includes a noble metal compound and has a pH value of 1-3;

[0039] Step S3, Electrodeposition: In the electroplating solution, using the titanium substrate as the anode and the titanium plate as the cathode, a stepped DC voltage sequence is applied using a programmable power supply. The stepped DC voltage sequence first deposits at 2V for 1 min, then at 4V for 10 min, and the current density is kept constant at 5 mA / cm² throughout the process. 2 A composite coating is formed on the surface of the titanium substrate;

[0040] Step S4: The electrodeposited titanium plate is dried and heat-treated sequentially to transform the coating into a composite metal oxide.

[0041] Step S5: Repeat steps S3-S4 until the noble metal loading in the coating reaches the target value.

[0042] In step S1, mechanical sandblasting is performed until the surface roughness Ra reaches 13-16μm and Rz reaches 75-90μm.

[0043] The acid etching process is as follows: use a mixed solution of 8-10wt% oxalic acid and 5-7wt% hydrochloric acid, and treat at 75-95℃ for 2-5 hours.

[0044] In step S2, the electroplating solution comprises the following components:

[0045] Iridium-containing compounds at concentrations of 0.3–0.5 mol / L, tantalum-containing compounds at concentrations of 0.1–0.2 mol / L, and tin-containing compounds at concentrations of 0.02–0.05 mol / L;

[0046] The electroplating solution is prepared by mixing the iridium-containing compound, the tantalum-containing compound, and the tin-containing compound in a volume ratio of 6:3:1.

[0047] In step S3, the distance between the cathode and the anode is 10-15 mm, and the cathode and the anode have the same area.

[0048] In step S3, the electroplating solution is heated by a water bath at a temperature of 50-70℃ and is stirred by electromagnetic stirring at a speed of 150-300 rpm.

[0049] In step S4, the drying temperature is 110-130℃ and the time is 5-10 min; the heat treatment is carried out in an air atmosphere at 400-500℃ for 15-30 min.

[0050] Repeat steps S3-S4 until the coating contains iridium oxide at a concentration of 15-20 g / m² and tantalum oxide at a concentration of 8-10 g / m².

[0051] Example 1: The active coating on the titanium substrate is: IrO2-Ta2O5-SnO2

[0052] A method for preparing a titanium anode plate includes the following steps:

[0053] Step S1, titanium matrix pretreatment, the specific method is as follows:

[0054] Take a titanium plate with a thickness of 1.0 mm, and first mechanically grind and sandblast it to Ra 13-16 μm. Z The roughness is approximately 75-90μm. The specific roughness of the sandblasted surface is measured using a portable roughness tester. If the Ra value is too high, the surface smoothness of the titanium plate is not high; if the Rz value is too high, deep pits are easily formed on the surface of the titanium plate, resulting in sharp local peaks or valleys; if the Ra and Rz values ​​are too low, the adhesion of the coating is low.

[0055] A mixed solution of oxalic acid and hydrochloric acid was used for acid etching at 85°C for 4 hours, wherein the mass concentration of oxalic acid was 8 wt% and the mass concentration of hydrochloric acid was 6 wt%.

[0056] The sample was then cleaned with purified water and dried before use. After sandblasting, acid etching, and cleaning, the microscopic surface of the sample was formed with uniform pits or a textured surface to increase the anchoring points for subsequent coatings.

[0057] Step S2, prepare the electroplating solution, the specific method is as follows:

[0058] Raw materials: Iridium-containing compounds, such as chloroiridic acid, iridium trichloride, or iridium tetrachloride; tantalum-containing compounds, such as tantalum pentachloride; tin-containing compounds, such as tin tetrachloride or stannous chloride;

[0059] The above compounds were diluted and mixed using a 1 mol / L sulfuric acid solution as a diluent.

[0060] The dilution concentrations are 0.3-0.5 mol / L for iridium-containing compounds, 0.1-0.2 mol / L for tantalum-containing compounds, and 0.02-0.05 mol / L for tin-containing compounds;

[0061] The three compounds were mixed thoroughly, and the mixture (volume ratio of solution 6:3:1) was used as the electroplating solution.

[0062] Step S3, electrodeposition, the specific process is as follows:

[0063] Using a titanium substrate as the anode and a titanium plate as the cathode, the titanium substrate was connected to the positive terminal of a programmable frequency converter power supply. The voltage sequence was set to deposit at 2V for 1 min, followed by depositing at 4V for 10 min, while maintaining a current density of 5 mA / cm². 2 ;

[0064] The distance between the cathode and the anode is 10-15 mm, and the cathode and the anode have the same area;

[0065] The electroplating solution is heated by a water bath at a temperature of 50-70℃ and is stirred by electromagnetic stirring at a speed of 150-300 rpm.

[0066] Step S4: The electrodeposited titanium plate is subsequently dried and heat-treated to transform the coating into a composite metal oxide. The specific method is as follows:

[0067] The titanium substrate that has undergone a voltage gradient is cleaned and dried with purified water. The drying is carried out in an electric heating drying oven at 120℃ for 5-10 minutes.

[0068] The dried titanium substrate is placed in an oxidation furnace for oxidation (temperature 450℃, holding for 20 min) to transform the coating into a composite metal oxide and form an IrO2-Ta2O5-SnO2-TiO2 composite coating.

[0069] Step S5: Repeat steps S3-S4 until the noble metal loading in the coating reaches the target value.

[0070] The coating was monitored using a direct-reading spectrometer until the iridium oxide content was determined to be 15-20 g / m³.2 The tantalum oxide content is calculated based on the amount of tantalum used, which is 8-10 g / m³. 2 count.

[0071] Comparative Example 1

[0072] Chinese Patent (CN2025 1 0822885.1, A high-performance titanium anode and its preparation method and application), the method adopts a coating process to prepare an IrO2-Ta2O5-SnO2-TiO2 composite coating.

[0073] Comparative Example 2

[0074] An IrO2-Ta2O5-SnO2-TiO2 composite coating was formed using an electrodeposition process. The process was based on that of Example 1, using a constant voltage of 4 V for electroplating, while other process parameters remained unchanged.

[0075] The titanium anode plates of Example 1, Comparative Example 1, and Comparative Example 2 were subjected to microstructure testing. The microstructure of the coating surface was detected by SEM images, and the results are as follows: Figure 1-3 As shown. By Figure 1 - 3 As can be seen, the coating surface prepared by the gradient voltage electrodeposition process described in this invention is uniform and dense, with no obvious cracks. In contrast, the coating process used in Comparative Example 1 has inherent drawbacks such as stress concentration, easy component segregation, and easy coating agglomeration, making it difficult to form a uniform coating structure at the microscale, ultimately resulting in a rough coating morphology containing a large number of macroscopic cracks. Although Comparative Example 2 also uses electrodeposition, it lacks a gradient voltage-controlled "gradual nucleation" stage and only uses a constant voltage for deposition, leading to uncontrolled deposition kinetics and ultimately forming a macroscopic defect structure similar to Comparative Example 1 (but with different causes).

[0076] EDX analysis showed that the coating formed by the method of this invention has a uniform distribution of noble metals.

[0077] The titanium anode plates of Example 1, Comparative Example 1, and Comparative Example 2 were subjected to enhanced life test analysis. The test methods and results are as follows:

[0078] 1. Experimental instruments and materials

[0079] High-frequency voltage and current device, multimeter, wires and connectors, tap water, sulfuric acid, beaker, glass rod, titanium anode plate.

[0080] 2. Experimental Procedure

[0081] Prepare a 1 mol / L sulfuric acid solution, stir thoroughly, and store at 50-60℃ for later use;

[0082] Pour the sulfuric acid solution into separate 1 L beakers, for a total volume of 1 L.

[0083] The test piece, which has been sanded on sandpaper, is attached to the sample hole cut to a size no larger than 10mm × 10mm and fixed to the positive electrode of the titanium anode material;

[0084] Connect the current and voltage device and the titanium anode material in series with wires; use sulfuric acid solution as electrolyte.

[0085] Turn on the power supply and set the appropriate current density: 40000A / m 2 ;

[0086] Record the initial voltage (usually 4 hours after the start of electrolysis), and then measure and record the voltage of each titanium anode at regular intervals every day.

[0087] The failure time of the standard test piece is when the voltage reaches 1.5 times the initial stable voltage, and the enhanced life test ends.

[0088] The test data is shown in Table 1:

[0089] Table 1: Enhanced lifespan test results for each embodiment

[0090]

[0091] The data above shows that, under the same environmental conditions, the titanium anode plate prepared by electrocoating in this invention has the longest lifespan, which is 3.1 times that of the anode plate in Comparative Example 1 and nearly 1.17 times that of the anode plate in Comparative Example 2, demonstrating excellent electrochemical performance. Comparing the initial and final voltages of Comparative Example 1, Comparative Example 2, and Example 1, under the same current density, Example 1 has a lower voltage and is more energy-efficient.

[0092] The titanium anode plates of Example 1, Comparative Example 1, and Comparative Example 2 were subjected to a comprehensive coating strength test (according to the ASTM D3359 cross-cut adhesion test) to quantify the bonding strength between the coating and the substrate. The test results are as follows: Figure 4 As shown in the figure. After cross-cut adhesion testing, no significant coating peeling was observed in Comparative Example 1, Comparative Example 2, and Example 1, indicating good coating adhesion. Furthermore, compared to the other two examples, the coating in Example 1 exhibited better adhesion to the substrate.

[0093] The method for preparing the titanium anode plate of the present invention produces a titanium anode plate with a uniform, dense, crack-free, and strongly bonded noble metal oxide coating on a titanium substrate, which can meet the stringent requirements of HVLP copper foil production.

[0094] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A method for preparing a titanium anode plate suitable for HVLP copper foil production, characterized in that, Includes the following steps: Step S1, titanium substrate pretreatment: The titanium substrate is mechanically polished and acid-etched in sequence to form a micro-rough surface on its surface; Step S2: Prepare an electroplating solution, wherein the electroplating solution includes a noble metal compound and has a pH value of 1-3; Step S3, Electrodeposition: In the electroplating solution, using the titanium substrate as the anode and the titanium plate as the cathode, a stepped DC voltage sequence is applied using a programmable power supply. The stepped DC voltage sequence first deposits at 2V for 1 min, then at 4V for 10 min, and the current density is kept constant at 5 mA / cm² throughout the process. 2 A composite coating is formed on the surface of the titanium substrate; Step S4: The electrodeposited titanium plate is dried and heat-treated sequentially to transform the coating into a composite metal oxide. Step S5: Repeat steps S3-S4 until the noble metal loading in the coating reaches the target value.

2. The preparation method according to claim 1, characterized in that, In step S1, mechanical sandblasting is performed until the surface roughness Ra reaches 13-16μm and Rz reaches 75-90μm.

3. The preparation method according to claim 2, characterized in that, The acid etching process is as follows: use a mixed solution of 8-10wt% oxalic acid and 5-7wt% hydrochloric acid, and treat at 75-95℃ for 2-5 hours.

4. The preparation method according to claim 1, characterized in that, In step S2, the electroplating solution comprises the following components: Iridium-containing compounds at concentrations of 0.3–0.5 mol / L, tantalum-containing compounds at concentrations of 0.1–0.2 mol / L, and tin-containing compounds at concentrations of 0.02–0.05 mol / L; The electroplating solution is prepared by mixing the iridium-containing compound, the tantalum-containing compound, and the tin-containing compound in a volume ratio of 6:3:

1.

5. The preparation method according to claim 1, characterized in that, In step S3, the distance between the cathode and the anode is 10-15 mm, and the cathode and the anode have the same area.

6. The preparation method according to claim 1, characterized in that, In step S3, the electroplating solution is heated by a water bath at a temperature of 50-70℃ and is stirred by electromagnetic stirring at a speed of 150-300 rpm.

7. The preparation method according to claim 1, characterized in that, In step S4, the drying temperature is 110-130℃ and the time is 5-10 min; the heat treatment is carried out in an air atmosphere at 400-500℃ for 15-30 min.

8. The preparation method according to claim 4, characterized in that, Repeat steps S3-S4 until the coating contains iridium oxide at a concentration of 15-20 g / m² and tantalum oxide at a concentration of 8-10 g / m².

9. A titanium anode plate suitable for HVLP copper foil production, characterized in that, Prepared by the method according to any one of claims 1-8.

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