Method for improving the corrosion resistance of copper foil surface using 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

Abstract

The present invention belongs to the technical field of copper foil preparation for the electronics industry, and specifically relates to a method for improving the corrosion resistance of the surface of copper foil by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor. The method comprises the following steps: preparation of 2-mercaptobenzothiazole; preparation of a cerium nitrate solution; preparation of a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor; preparation of an electrodeposited copper foil; and corrosion inhibition treatment of the copper foil. The method of improving the corrosion resistance of the surface of copper foil by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor, MBT-Ce corrosion resistance treatment and passivation treatment described in the present invention can significantly improve the corrosion resistance of the copper foil, thereby extending its service life in harsh environments; at the same time, the surface quality of the copper foil is improved, making it smoother and flatter, which is beneficial for subsequent processing and application; in addition, the peel strength value is improved, making it more durable during use; finally, production efficiency is improved, production costs are reduced, and large-scale production is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of copper foil preparation for the electronic industry, and specifically relates to a method for improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor. Background Art

[0002] Copper foil is widely used in numerous fields, including electronics, electrical engineering, communications, and aerospace. For example, in printed circuit board (PCB) manufacturing, copper foil is a key conductive material. However, copper foil is susceptible to corrosion during use due to environmental factors (humid air and corrosive gases). This not only affects its conductivity but also reduces its service life, ultimately impacting the reliability of the entire electronic product. Therefore, improving the corrosion resistance of copper foil is crucial to ensuring its long-term stable operation in complex environments.

[0003] In practice, various methods exist to improve the corrosion resistance of copper foil. For example, electroless plating deposits a uniform metal coating on the surface of copper foil. This coating forms a strong protective layer that effectively isolates corrosive media. Furthermore, alloying copper with small amounts of other metals (such as zinc, nickel, or tin) can alter the material's chemical composition to enhance corrosion resistance. Furthermore, the use of corrosion inhibitors or passivation treatments can create a dense protective film on the surface of copper foil, further enhancing its corrosion resistance. Using corrosion inhibitors to create a protective film on the surface of copper foil is a simple and practical method to inhibit corrosion.

[0004] There are many types of copper foil corrosion inhibitors available, which can be divided into organic, inorganic, and composite corrosion inhibitors. Organic corrosion inhibitors, including imidazoline, amine, and phenolic corrosion inhibitors, form a protective film on the copper foil surface through adsorption. Inorganic corrosion inhibitors, including chromate, phosphate, and silicate corrosion inhibitors, form a dense protective film on the copper foil surface through chemical reactions. Composite corrosion inhibitors, including organic-inorganic composite corrosion inhibitors and multifunctional composite corrosion inhibitors, further enhance the corrosion inhibition effect by combining the advantages of multiple corrosion inhibitors.

[0005] While existing corrosion inhibitors can inhibit copper foil corrosion to a certain extent, they still face some challenges. For example, their efficiency is often insufficient, making them ineffective in effectively protecting copper foil over long-term use. Furthermore, some inhibitors may pose environmental risks and fail to meet increasingly stringent environmental protection requirements. Therefore, it is necessary to explore new methods for improving the corrosion resistance of copper foil surfaces. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor. The method can improve the corrosion resistance of the copper foil and extend the service life of the copper foil.

[0007] The method of improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to the present invention comprises the following steps:

[0008] (1) Preparation of 2-mercaptobenzothiazole

[0009] o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole;

[0010] (2) Preparation of cerium nitrate solution

[0011] The cerium nitrate hexahydrate is placed in an oven and dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in anhydrous ethanol to prepare a cerium nitrate solution;

[0012] (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

[0013] The 2-mercaptobenzothiazole prepared in step (1) is added to the cerium nitrate solution prepared in step (2), and the mixture is stirred and reacted at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor;

[0014] (4) Preparation of electrodeposited copper foil

[0015] ① Evenly mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide dipropane sulfonate and sodium 3-mercapto-1-propane sulfonate to prepare an electrolyte;

[0016] ② Cut the copper foil into sheets, then wipe and clean them. Use the wiped copper foil as the cathode and the platinum electrode as the anode, place them in the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare electrodeposited copper foil;

[0017] (5) Corrosion inhibition treatment of copper foil

[0018] ① Clean the electrodeposited copper foil to remove oil and oxides on the surface;

[0019] ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition.

[0020] in:

[0021] In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; and the mass ratio of anhydrous ethanol to o-aminothiophenol is 65:1.

[0022] The stirring reaction time in step (1) is 6.5-6.8h.

[0023] In step (1), the product is washed with deionized water for 3-4 times, the drying temperature is 75-78°C, and the drying time is 5.5h.

[0024] In step (2), the drying temperature is 110° C. and the drying time is 2 h.

[0025] When preparing the cerium nitrate solution in step (2), the reaction is carried out under stirring at room temperature for 0.5-1 h. The solubility of the prepared cerium nitrate solution is 10 g / L.

[0026] In step (3), the volume ratio of the mass of 2-mercaptobenzothiazole to the cerium nitrate solution is 1:10-11, and the unit is g / mL.

[0027] In step (3), the stirring reaction temperature is 35-40° C., and the stirring reaction time is 0.8-1 h.

[0028] In the electrolyte described in step (4) ①, the concentration of copper sulfate pentahydrate is 240 g / L, the concentration of sulfuric acid is 160.0 g / L, the concentration of sodium chloride is 0.124 g / L, the concentration of sodium polydisulfide propane sulfonate (SPS) is 1.0 mg / L, and the concentration of sodium 3-mercapto-1-propanesulfonate (MPS) is 1.5 mg / L.

[0029] Step (4) ② The copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm.

[0030] The wiping agent used in step (4) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the original copper foil surface.

[0031] In step (4) ②, the distance between the cathode and the anode during electrodeposition is 10 cm, and the current density is 2.8 A / dm 2 , the deposition time is controlled at 2-4min.

[0032] The cleaning and drying in step (4) ② is to use ethanol as a cleaning agent, use ultrasound to clean the sample, and dry it at room temperature for 0.5h with an ultrasonic power of 30-50W.

[0033] In step (5) ①, the sample was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0034] The concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used in step (5) ② is 3 g / L, with water as the solvent.

[0035] In step (5) ②, the soaking time is 3-5 min, and the soaking temperature is 30-35°C.

[0036] In step (5) ②, the temperature of low temperature drying is 50-53°C and the time is 5-7 minutes.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention provides a method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor, wherein the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor is prepared from 2-mercaptobenzothiazole (MBT) and cerium (Ce) by a specific chemical synthesis method, MBT has good adsorption properties and can form a preliminary protective film on the surface of metal copper foil, and the addition of Ce element synergistically with MBT can further enhance the density and stability of the protective film and significantly reduce the corrosion rate of metal copper foil; the electroplating copper technology provides more active sites for the corrosion inhibitor, enhances the adsorption capacity of the corrosion inhibitor, and enables MBT-Ce to more effectively form a dense protective film on the surface of the copper foil, thereby improving the corrosion resistance of the copper foil in harsh environments.

[0039] (2) The method of improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in the present invention is that the MBT molecules in MBT-Ce are first adsorbed on the active sites on the copper foil surface through their active groups, preventing corrosive media (such as oxygen, water, etc.) from directly contacting the copper foil surface. In addition, the Ce element reacts chemically with the copper foil surface and MBT to form a composite protective film. This protective film has good barrier properties and can effectively inhibit the penetration of corrosive ions (such as chloride ions, etc.), thereby significantly reducing the corrosion rate of the copper foil. This protective film can not only effectively isolate the corrosive medium, but also has good self-healing ability, thereby continuously protecting the copper foil during long-term use.

[0040] (3) The method of improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in the present invention, MBT-Ce corrosion resistance treatment and passivation treatment can significantly improve the corrosion resistance of the copper foil, thereby extending its service life in harsh environments; at the same time, the surface quality of the copper foil is improved, making it smoother and flatter, which is beneficial for subsequent processing and application; in addition, the peel strength value is increased, making it more durable during use; finally, the production efficiency is improved, the production cost is reduced, and it is beneficial for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a scanning electron microscope image of the copper foil prepared in Example 1 after being corroded by ferric chloride corrosive solution;

[0042] Figure 2 This is a scanning electron microscope image of the copper foil prepared in Comparative Example 1 after being corroded by ferric chloride corrosive solution;

[0043] Figure 3 This is a scanning electron microscope image of the copper foil prepared in Comparative Example 2 after being corroded by ferric chloride etching solution. DETAILED DESCRIPTION

[0044] The present invention will be further described below with reference to the examples.

[0045] Example 1

[0046] The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor as described in Example 1 comprises the following steps:

[0047] (1) Preparation of 2-mercaptobenzothiazole

[0048] o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole;

[0049] (2) Preparation of cerium nitrate solution

[0050] The cerium nitrate hexahydrate is placed in an oven and dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in anhydrous ethanol to prepare a cerium nitrate solution;

[0051] (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

[0052] The 2-mercaptobenzothiazole prepared in step (1) is added to the cerium nitrate solution prepared in step (2), and the mixture is stirred and reacted at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor;

[0053] (4) Preparation of electrodeposited copper foil

[0054] ① Evenly mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide propane sulfonate (SPS) and sodium 3-mercapto-1-propane sulfonate (MPS) to prepare an electrolyte;

[0055] ② Cut the copper foil into sheets, then wipe and clean them. Use the wiped copper foil as the cathode and the platinum electrode as the anode, place them in the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare electrodeposited copper foil;

[0056] (5) Corrosion inhibition treatment of copper foil

[0057] ① Clean the electrodeposited copper foil to remove oil and oxides on the surface;

[0058] ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition.

[0059] in:

[0060] In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; and the mass ratio of ethanol to o-aminothiophenol is 65:1.

[0061] The stirring reaction time in step (1) is 6.5 h.

[0062] In step (1), the product was washed with deionized water three times, the drying temperature was 75°C, and the drying time was 5.5 h.

[0063] In step (2), the drying temperature is 110° C. and the drying time is 2 h.

[0064] When preparing the cerium nitrate solution in step (2), the reaction is carried out under stirring at room temperature for 0.5 h. The solubility of the prepared cerium nitrate solution is 10 g / L.

[0065] In step (3), the volume ratio of the mass of 2-mercaptobenzothiazole to the cerium nitrate solution is 1:10.5, and the unit is g / mL.

[0066] In step (3), the stirring reaction temperature is 35° C. and the stirring reaction time is 1 h.

[0067] In the electrolyte described in step (4) ①, the concentration of copper sulfate pentahydrate is 240 g / L, the concentration of sulfuric acid is 160.0 g / L, the concentration of sodium chloride is 0.124 g / L, the concentration of sodium polydisulfide propane sulfonate is 1.0 mg / L, and the concentration of sodium 3-mercapto-1-propane sulfonate is 1.5 mg / L.

[0068] Step (4) ② The copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm.

[0069] The wiping agent used in step (4) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the original copper foil surface.

[0070] In step (4) ②, the distance between the cathode and the anode during electrodeposition is 10 cm, and the current density is 2.8 A / dm 2 , the deposition time is controlled at 2 minutes.

[0071] The cleaning and drying in step (4) ② uses ethanol as a cleaning agent and uses ultrasound to clean the sample. The drying time is 0.5 h at room temperature and the ultrasonic power is 30 W.

[0072] In step (5) ①, the sample was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0073] The concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used in step (5) ② is 3 g / L, with water as the solvent.

[0074] In step (5) ②, the soaking time is 3 minutes and the soaking temperature is 35°C.

[0075] The temperature of low temperature drying in step (5) ② is 50°C and the time is 7 minutes.

[0076] Example 2

[0077] The method for improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in Example 2 comprises the following steps:

[0078] (1) Preparation of 2-mercaptobenzothiazole

[0079] o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole;

[0080] (2) Preparation of cerium nitrate solution

[0081] The cerium nitrate hexahydrate is placed in an oven and dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in anhydrous ethanol to prepare a cerium nitrate solution;

[0082] (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

[0083] The 2-mercaptobenzothiazole prepared in step (1) is added to the cerium nitrate solution prepared in step (2), and the mixture is stirred and reacted at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor;

[0084] (4) Preparation of electrodeposited copper foil

[0085] ① Evenly mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide propane sulfonate (SPS) and sodium 3-mercapto-1-propane sulfonate (MPS) to prepare an electrolyte;

[0086] ② Cut the copper foil into sheets, then wipe and clean them. Use the wiped copper foil as the cathode and the platinum electrode as the anode, place them in the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare electrodeposited copper foil;

[0087] (5) Corrosion inhibition treatment of copper foil

[0088] ① Clean the electrodeposited copper foil to remove oil and oxides on the surface;

[0089] ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition.

[0090] in:

[0091] In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; and the mass ratio of ethanol to o-aminothiophenol is 65:1.

[0092] The stirring reaction time in step (1) is 6.6 h.

[0093] In step (1), the product was washed with deionized water three times, the drying temperature was 76°C, and the drying time was 5.5 h.

[0094] In step (2), the drying temperature is 110° C. and the drying time is 2 h.

[0095] When preparing the cerium nitrate solution in step (2), the reaction is carried out under stirring at room temperature for 0.8 h. The solubility of the prepared cerium nitrate solution is 10 g / L.

[0096] In step (3), the volume ratio of the mass of 2-mercaptobenzothiazole to the cerium nitrate solution is 1:10, and the unit is g / mL.

[0097] In step (3), the stirring reaction temperature is 38° C., and the stirring reaction time is 0.9 h.

[0098] In the electrolyte described in step (4) ①, the concentration of copper sulfate pentahydrate is 240 g / L, the concentration of sulfuric acid is 160.0 g / L, the concentration of sodium chloride is 0.124 g / L, the concentration of sodium polydisulfide propane sulfonate is 1.0 mg / L, and the concentration of sodium 3-mercapto-1-propane sulfonate is 1.5 mg / L.

[0099] Step (4) ② The copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm.

[0100] The wiping agent used in step (4) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the original copper foil surface.

[0101] In step (4) ②, the distance between the cathode and the anode during electrodeposition is 10 cm, and the current density is 2.8 A / dm 2 , the deposition time is controlled at 4 minutes.

[0102] The cleaning and drying in step (4) ② uses ethanol as a cleaning agent and uses ultrasound to clean the sample. The drying time is 0.5 h at room temperature and the ultrasonic power is 40 W.

[0103] In step (5) ①, the sample was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0104] The concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used in step (5) ② is 3 g / L, with water as the solvent.

[0105] In step (5) ②, the soaking time is 4 minutes and the soaking temperature is 33°C.

[0106] In step (5) ②, the temperature of low-temperature drying is 52°C and the time is 6 minutes.

[0107] Example 3

[0108] The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in Example 3 comprises the following steps:

[0109] (1) Preparation of 2-mercaptobenzothiazole

[0110] o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole;

[0111] (2) Preparation of cerium nitrate solution

[0112] The cerium nitrate hexahydrate is placed in an oven and dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in anhydrous ethanol to prepare a cerium nitrate solution;

[0113] (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

[0114] The 2-mercaptobenzothiazole prepared in step (1) is added to the cerium nitrate solution prepared in step (2), and the mixture is stirred and reacted at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor;

[0115] (4) Preparation of electrodeposited copper foil

[0116] ① Evenly mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide propane sulfonate (SPS) and sodium 3-mercapto-1-propane sulfonate (MPS) to prepare an electrolyte;

[0117] ② Cut the copper foil into sheets, then wipe and clean them. Use the wiped copper foil as the cathode and the platinum electrode as the anode, place them in the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare electrodeposited copper foil;

[0118] (5) Corrosion inhibition treatment of copper foil

[0119] ① Clean the electrodeposited copper foil to remove oil and oxides on the surface;

[0120] ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition.

[0121] in:

[0122] In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; and the mass ratio of ethanol to o-aminothiophenol is 65:1.

[0123] The stirring reaction time in step (1) is 6.8 h.

[0124] In step (1), the product was washed with deionized water 4 times, the drying temperature was 78°C, and the drying time was 5.5 h.

[0125] In step (2), the drying temperature is 110° C. and the drying time is 2 h.

[0126] When preparing the cerium nitrate solution in step (2), the stirring reaction is carried out at room temperature for 1 hour. The solubility of the prepared cerium nitrate solution is 10 g / L.

[0127] In step (3), the volume ratio of the mass of 2-mercaptobenzothiazole to the cerium nitrate solution is 1:11, and the unit is g / mL.

[0128] In step (3), the stirring reaction temperature is 40° C., and the stirring reaction time is 0.8 h.

[0129] In the electrolyte described in step (4) ①, the concentration of copper sulfate pentahydrate is 240 g / L, the concentration of sulfuric acid is 160.0 g / L, the concentration of sodium chloride is 0.124 g / L, the concentration of sodium polydisulfide propane sulfonate is 1.0 mg / L, and the concentration of sodium 3-mercapto-1-propane sulfonate is 1.5 mg / L.

[0130] Step (4) ② The copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm.

[0131] The wiping agent used in step (4) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the original copper foil surface.

[0132] In step (4) ②, the distance between the cathode and the anode during electrodeposition is 10 cm, and the current density is 2.8 A / dm 2 , the deposition time is controlled at 3min.

[0133] The cleaning and drying in step (4) ② uses ethanol as a cleaning agent and uses ultrasound to clean the sample. The drying time is 0.5 h at room temperature and the ultrasonic power is 50 W.

[0134] In step (5) ①, the sample was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0135] The concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used in step (5) ② is 3 g / L, with water as the solvent.

[0136] In step (5) ②, the soaking time is 5 minutes and the soaking temperature is 30°C.

[0137] The temperature of low temperature drying in step (5) ② is 53°C and the time is 5 minutes.

[0138] Comparative Example 1

[0139] The method for improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in Comparative Example 1 comprises the following steps:

[0140] (1) Preparation of 2-mercaptobenzothiazole

[0141] o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole;

[0142] (2) Preparation of electrodeposited copper foil

[0143] ① Evenly mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide propane sulfonate (SPS) and sodium 3-mercapto-1-propane sulfonate (MPS) to prepare an electrolyte;

[0144] ② Cut the copper foil into sheets, then wipe and clean them. Use the wiped copper foil as the cathode and the platinum electrode as the anode, place them in the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare electrodeposited copper foil;

[0145] (3) Corrosion inhibition treatment of copper foil

[0146] ① Clean the electrodeposited copper foil to remove oil and oxides on the surface;

[0147] ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition.

[0148] in:

[0149] In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; and the mass ratio of ethanol to o-aminothiophenol is 65:1.

[0150] The stirring reaction time in step (1) is 6.5 h.

[0151] In step (1), the product was washed with deionized water three times, the drying temperature was 75°C, and the drying time was 5.5 h.

[0152] In the electrolyte described in step (2) ①, the concentration of copper sulfate pentahydrate is 240 g / L, the concentration of sulfuric acid is 160.0 g / L, the concentration of sodium chloride is 0.124 g / L, the concentration of sodium polydisulfide propane sulfonate is 1.0 mg / L, and the concentration of sodium 3-mercapto-1-propane sulfonate is 1.5 mg / L.

[0153] Step (2) ② The copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm.

[0154] The wiping agent used in step (2) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the original copper foil surface.

[0155] In step (2) ②, the distance between the cathode and the anode is 10 cm, and the current density is 2.8 A / dm 2 , the deposition time is controlled at 2 minutes.

[0156] The cleaning and drying in step (2) ② uses ethanol as a cleaning agent and uses ultrasound to clean the sample. The drying time is 0.5 h at room temperature and the ultrasonic power is 30W.

[0157] In step (3) ①, the sample was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0158] The concentration of the 2-mercaptobenzothiazole corrosion inhibitor solution used in step (3) ② is 3 g / L, with water as the solvent.

[0159] In step (3) ②, the soaking time is 3 min and the soaking temperature is 35°C.

[0160] The temperature of the low temperature drying in step (3) ② is 50°C and the time is 7 minutes.

[0161] Comparative Example 2

[0162] The method for improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in Comparative Example 2 comprises the following steps:

[0163] (1) Preparation of 2-mercaptobenzothiazole

[0164] o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole;

[0165] (2) Preparation of cerium nitrate solution

[0166] The cerium nitrate hexahydrate is placed in an oven and dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in anhydrous ethanol to prepare a cerium nitrate solution;

[0167] (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

[0168] The 2-mercaptobenzothiazole prepared in step (1) is added to the cerium nitrate solution prepared in step (2), and the mixture is stirred and reacted at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor;

[0169] (4) Corrosion inhibition treatment of copper foil

[0170] ①Cut the copper foil into sheets, clean it and remove the oil and oxide on the surface;

[0171] ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition.

[0172] in:

[0173] In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; and the mass ratio of ethanol to o-aminothiophenol is 65:1.

[0174] The stirring reaction time in step (1) is 6.5 h.

[0175] In step (1), the product was washed with deionized water three times, the drying temperature was 75°C, and the drying time was 5.5 h.

[0176] In step (2), the drying temperature is 110° C. and the drying time is 2 h.

[0177] When preparing the cerium nitrate solution in step (2), the reaction is carried out under stirring at room temperature for 0.5 h. The solubility of the prepared cerium nitrate solution is 10 g / L.

[0178] In step (3), the volume ratio of the mass of 2-mercaptobenzothiazole to the cerium nitrate solution is 1:10.5, and the unit is g / mL.

[0179] In step (3), the stirring reaction temperature is 35° C., and the stirring reaction time is 1 h.

[0180] Step (4) ① The copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm.

[0181] In step (4) ①, the sample was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0182] The concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used in step (4) ② is 3 g / L, with water as the solvent.

[0183] In step (4) ②, the soaking time is 3 min and the soaking temperature is 35°C.

[0184] In step (4) ②, the temperature of low-temperature drying is 50°C and the time is 7 minutes.

[0185] Copper foil samples prepared in Examples 1-3 and Comparative Examples 1-2 were polarized in a 3.5% sodium chloride solution for 5 minutes. Tafel and electrochemical impedance spectroscopy (EIS) measurements were then performed in the same system. The EIS spectra were fitted using ZView software to obtain Rs and Rct data. Tables 1 and 2 present the test results. Table 1 shows that Examples 1-3 (MBT-Ce) exhibit lower corrosion currents compared to Comparative Example 2 (MBT-Ce without deposition) and Comparative Example 1 (MBT). This indicates that the introduction of MBT-Ce effectively inhibits electrochemical corrosion activity on the copper foil surface. Table 2 shows that Examples 1-3 exhibit higher electrolyte solution resistance (Rs) and charge transfer resistance (Rct). The significant increase in Rct in Examples 1-3 compared to Comparative Example 1 indicates that the protective film formed by MBT-Ce on the copper surface effectively hinders charge transfer, thereby significantly improving the corrosion resistance of the system. Compared to Comparative Example 2, the Rct values of the deposited MBT-Ce in Examples 1-3 are significantly higher than those of the undeposited MBT-Ce. This phenomenon can be attributed to the microstructural regulation imparted by the electrodeposition copper process. Electrodeposition copper increases the density of surface active sites, promoting the adsorption of MBT-Ce molecules at the interface. The two synergistically form a dense and stable passivation film. This synergistic mechanism not only enhances the adsorption efficiency of the corrosion inhibitor but also blocks the penetration of corrosive media through a physical barrier effect, providing a dual guarantee for the long-term stability of the copper foil in harsh environments.

[0186] Table 1 Corrosion current test results of copper foil prepared in Examples 1-3 and Comparative Examples 1-2

[0187]

[0188] Table 2 Rs and Rct data of copper foil prepared in Examples 1-3 and Comparative Examples 1-2 fitted by AC impedance test

[0189]

[0190] Figure 1-3 The scanning electron microscope images of Example 1, Comparative Example 1 and Comparative Example 2 were obtained by etching for 10 seconds in ferric chloride etching solution (composed of 5g FeCl3+25ml hydrochloric acid+100ml anhydrous ethanol). Figure 1 and Figure 2 , Figure 2 The deeper the pores, the more serious the corrosion effect. This result shows that the corrosion inhibition effect of a single MBT corrosion inhibitor is insufficient and it is difficult to effectively inhibit the Cl - This phenomenon is consistent with the higher corrosion current density of this group in Table 1, confirming that its protective effectiveness is limited. Figure 1 and Figure 3 ,from Figure 3The surface flatness is high and the active site density is low. The SEM image shows that the corrosion inhibitor is distributed in an island shape and there are obvious uncovered gaps at the interface, which causes the corrosive medium to penetrate quickly along the defects and form shallow pitting pits. The electrodeposition process constructs a high-roughness copper layer with a uniform nano-scale protrusion structure on the surface, such as Figure 1 The surface roughness is higher and there are more active sites on the surface, which is conducive to the adsorption of MBT-Ce. MBT-Ce molecules form strong chemical adsorption with the copper surface through thiol groups (-SH), and with the help of cerium ions (Ce 3+ The hydrolysis products of MBT-Ce fill the micropores of the deposited layer, ultimately forming a thick, dense composite film. This synergistic effect of MBT-Ce and the electrodeposited copper layer results in a denser MBT-Ce distribution and better corrosion resistance.

Claims

1. A method for improving the corrosion resistance of copper foil surface using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor, characterized in that: It consists of the following steps: (1) Preparation of 2-mercaptobenzothiazole o-Aminothiophenol, carbon disulfide and sodium hydroxide solution are added to a reaction vessel, and then anhydrous ethanol is added and stirred at room temperature for reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to obtain a crude 2-mercaptobenzothiazole product, which is then washed with deionized water and dried to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution The cerium nitrate hexahydrate is placed in an oven and dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in anhydrous ethanol to prepare a cerium nitrate solution; (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor The 2-mercaptobenzothiazole prepared in step (1) is added to the cerium nitrate solution prepared in step (2), and the mixture is stirred at 35-40° C. for 0.8-1 h to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor; (4) Preparation of electrodeposited copper foil ① Evenly mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide dipropane sulfonate and sodium 3-mercapto-1-propane sulfonate to prepare an electrolyte; ② Cut the copper foil into sheets, then wipe and clean them. Use the wiped copper foil as the cathode and the platinum electrode as the anode, place them in the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare electrodeposited copper foil; (5) Corrosion inhibition treatment of copper foil ① Clean the electrodeposited copper foil to remove oil and oxides on the surface; ② Soak the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after soaking, rinse it with deionized water, and then dry it at low temperature to prepare a copper foil with corrosion inhibition; in: In step (3), the mass ratio of 2-mercaptobenzothiazole to the volume ratio of the cerium nitrate solution is 1:10-11, expressed in g / mL; In the electrolyte described in step (4) ①, the concentration of copper sulfate pentahydrate is 240 g / L, the concentration of sulfuric acid is 160.0 g / L, the concentration of sodium chloride is 0.124 g / L, the concentration of sodium polydisulfide propane sulfonate is 1.0 mg / L, and the concentration of sodium 3-mercapto-1-propane sulfonate is 1.5 mg / L; In step (4) ②, the distance between the cathode and the anode during electrodeposition is 10 cm, and the current density is 2.8 A / dm 2 , the deposition time is controlled at 2-4min.

2. The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: In step (1), the molar ratio of o-aminothiophenol to carbon disulfide is 1:1.1, the mass concentration of the sodium hydroxide solution is 30%, and the molar ratio of the sodium hydroxide solution to o-aminothiophenol is 1.8:1; The mass ratio of anhydrous ethanol to o-aminothiophenol is 65:

1.

3. The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: The stirring reaction time in step (1) is 6.5-6.8 hours; the deionized water washing in step (1) is 3-4 times, the drying temperature is 75-78°C, and the drying time is 5.5 hours.

4. The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: The drying temperature in step (2) is 110° C. and the drying time is 2 h. When preparing the cerium nitrate solution in step (2), the stirring reaction is carried out at room temperature for 0.5-1 h. The solubility of the prepared cerium nitrate solution is 10 g / L.

5. The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: The copper foil in step (4) ② is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm*14 cm; the wiping agent used in the wiping and cleaning in step (4) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the surface of the original copper foil.

6. The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: The cleaning and drying in step (4) ② is to use ethanol as a cleaning agent, use ultrasound to clean the sample, and dry it at room temperature for 0.5h with an ultrasonic power of 30-50W.

7. The method for improving the corrosion resistance of copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: In step (5) ①, the sample is first washed three times with deionized water and then washed twice with anhydrous ethanol; the concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used in step (5) ② is 3 g / L, and water is used as the solvent.

8. The method for improving the corrosion resistance of copper foil surface using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: In step (5) ②, the soaking time is 3-5 minutes, and the soaking temperature is 30-35°C; in step (5) ②, the low-temperature drying temperature is 50-53°C, and the time is 5-7 minutes.

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