Method for improving surface corrosion resistance of copper foil by adopting 2-mercaptobenzothiazole-cerium composite corrosion inhibitor

Abstract

The invention belongs to the technical field of preparation of copper foils for the electronic industry, and particularly relates to a method for improving the surface corrosion resistance of a copper foil by adopting a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor. The preparation method comprises the following steps: preparing 2-mercaptobenzothiazole; preparing a cerium nitrate solution; preparation of the 2-mercaptobenzothiazole-cerium compound type corrosion inhibitor is carried out; preparing an electro-deposition copper foil; and carrying out corrosion inhibition treatment on the copper foil. According to the method for improving the corrosion resistance of the surface of the copper foil by adopting the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor, the corrosion resistance of the copper foil can be remarkably improved through MBT-Ce corrosion resistance treatment and passivation treatment, so that the service life of the copper foil in a severe environment is prolonged; meanwhile, the surface quality of the copper foil is improved, so that the copper foil is smoother, and subsequent processing and application are facilitated; in addition, the anti-stripping strength value can be improved, so that the adhesive is more durable in the use process; and finally, production efficiency is improved, production cost is reduced, and large-scale production is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of copper foil preparation for the electronic industry, and particularly 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 foils are widely used in many fields such as the electronic industry, electrical engineering, communication, aerospace, etc. For example, in the manufacture of printed circuit boards (PCBs), copper foils are key conductive materials. However, copper foils are prone to corrosion under the influence of environmental factors (humid air and corrosive gases) during use, which not only affects their electrical conductivity but also reduces their service life, thus affecting the reliability of the entire electronic product. Therefore, improving the corrosion resistance of the copper foil surface is crucial for ensuring its long-term stable operation in complex environments.

[0003] In practical applications, there are various methods for improving the corrosion resistance of the copper foil surface. For example, a uniform metal coating can be deposited on the copper foil surface by electroless plating, and this coating can form a solid protective layer to effectively isolate the corrosive medium. In addition, a small amount of other metals (such as zinc, nickel, or tin) can be added to copper to form an alloy, thereby enhancing its corrosion resistance by changing the chemical composition of the material. Additionally, using a corrosion inhibitor or performing passivation treatment can generate a dense protective film on the copper foil surface to further improve its corrosion resistance. Among them, using a corrosion inhibitor to generate a protective film on the copper foil surface to inhibit copper foil corrosion is a simple and practical method.

[0004] Existing copper foil corrosion inhibitors are diverse and can be divided into organic corrosion inhibitors, inorganic corrosion inhibitors, and composite corrosion inhibitors. Organic corrosion inhibitors form a protective film by adsorbing on the copper foil surface, including imidazoline-based corrosion inhibitors, amine-based corrosion inhibitors, and phenolic corrosion inhibitors. Inorganic corrosion inhibitors form a dense protective film on the copper foil surface through chemical reactions, including chromate corrosion inhibitors, phosphate corrosion inhibitors, and silicate corrosion inhibitors. Composite corrosion inhibitors further improve the corrosion inhibition effect by combining the advantages of various corrosion inhibitors, including organic-inorganic composite corrosion inhibitors and multifunctional composite corrosion inhibitors.

[0005] Although the existing corrosion inhibitors can play a corrosion inhibition role on copper foils to a certain extent, there are still some problems. For example, the corrosion inhibition efficiency of the corrosion inhibitor is not high enough, and it is difficult to continuously and effectively protect the copper foil during long-term use; some corrosion inhibitors may also cause environmental pollution and do not meet the increasingly strict environmental protection requirements. Therefore, it is necessary to explore a new method for improving the corrosion resistance of the copper foil surface. Summary of the Invention

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

[0007] The method for improving the corrosion resistance of the surface of copper foil by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to the present invention comprises the following steps: (1) Preparation of 2-mercaptobenzothiazole Add o-aminothiophenol, carbon disulfide and sodium hydroxide solution into a reaction vessel, then add absolute ethanol and carry out stirring reaction at room temperature. After the reaction is completed, cool to room temperature, filter to obtain the crude product of 2-mercaptobenzothiazole, and finally wash with deionized water and dry to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution Put cerium nitrate hexahydrate into an oven for drying to obtain pure cerium nitrate monomer, and then dissolve the pure cerium nitrate monomer in absolute ethanol to prepare a cerium nitrate solution; (3) Preparation of 2-mercaptobenzothiazole-cerium composite corrosion inhibitor Add the 2-mercaptobenzothiazole prepared in step (1) into the cerium nitrate solution prepared in step (2), and carry out stirring reaction at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor; (4) Preparation of electrodeposited copper foil ① Mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydithiopropanesulfonate and 3-mercapto-1-propanesulfonate uniformly to prepare an electrolyte; ② Cut the copper foil into sheets, then wipe and clean it. Use the wiped copper foil as the cathode and a platinum electrode as the anode, put them into the electrolyte prepared in step ① for electrodeposition, and finally wash and dry to prepare an electrodeposited copper foil; (5) Corrosion inhibition treatment of copper foil ① Clean the electrodeposited copper foil to remove the oil and oxide on the surface; ② Immerse the cleaned copper foil in the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, take it out after the immersion is completed, rinse it with deionized water, and then carry out low-temperature drying to prepare a copper foil with corrosion inhibition.

[0008] Among them: 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 absolute ethanol to o-aminothiophenol is 65:1.

[0009] In step (1), the stirring reaction time is 6.5 - 6.8 h.

[0010] In step (1), it is washed with deionized water 3 - 4 times, the drying temperature is 75 - 78 °C, and the drying time is 5.5 h.

[0011] In step (2), the drying temperature is 110 °C and the drying time is 2 h.

[0012] In step (2), when preparing the cerium nitrate solution, the stirring reaction is carried out at room temperature, the stirring reaction time is 0.5 - 1 h, and the concentration of the prepared cerium nitrate solution is 10 g / L.

[0013] In step (3), the mass ratio of 2 - mercaptobenzothiazole to the volume of the cerium nitrate solution is 1:10 - 11, with the unit of g / mL.

[0014] In step (3), the stirring reaction temperature is 35 - 40 °C and the stirring reaction time is 0.8 - 1 h.

[0015] 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.

[0016] The copper foil described in step (4) ② is a rolled copper foil with a thickness of 12 μm, which is cut into a sheet with a size of 6.5 cm * 14 cm.

[0017] The wiping reagent used in the wiping and cleaning in step (4) ② is anhydrous ethanol, which is dropped on the gauze to wipe off the impurities on the surface of the original copper foil.

[0018] In step (4) ②, the distance between the cathode and the anode during electro - deposition is 10 cm, and the current density is 2.8 A / dm 2 , and the deposition time is controlled within 2 - 4 min.

[0019] The cleaning and drying in step (4) ② uses ethanol as the cleaning reagent, and the sample is cleaned clean by ultrasonic waves, dried at room temperature for 0.5 h, and the ultrasonic power is 30 - 50 W.

[0020] In step (5) ①, it is first cleaned 3 times with deionized water and then 2 times with anhydrous ethanol.

[0021] In step (5) ②, the concentration of the 2 - mercaptobenzothiazole - cerium composite inhibitor solution used is 3 g / L, with water as the solvent.

[0022] In step (5) ②, the soaking duration is 3 - 5 min and the soaking temperature is 30 - 35 °C.

[0023] In step (5) ②, the low-temperature drying temperature is 50-53 °C and the time is 5-7 min.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) In the method for improving the corrosion resistance of the copper foil surface by using the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor of the present invention, 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 performance and can form a preliminary protective film on the surface of the metal copper foil. The addition of Ce element acts synergistically with MBT, which can further enhance the compactness and stability of the protective film and significantly reduce the corrosion rate of the metal copper foil. The electrodeposition copper deposition technology provides more active sites for the corrosion inhibitor, enhances the adsorption ability of the corrosion inhibitor, and enables MBT-Ce to more effectively form a dense protective film on the copper foil surface, thereby improving the corrosion resistance of the copper foil in harsh environments.

[0025] (2) In the method for improving the corrosion resistance of the copper foil surface by using the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor of the present invention, the MBT molecules in MBT-Ce first adsorb 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 corrosion 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 corrosion medium, but also has good self-healing ability, thus continuously protecting the copper foil during long-term use.

[0026] (3) In the method for improving the corrosion resistance of the copper foil surface by using the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor of the present invention, the corrosion resistance treatment and passivation treatment of MBT-Ce can significantly improve the corrosion resistance of the copper foil, extend its service life in harsh environments; at the same time, improve the surface quality of the copper foil, make it smoother and flatter, which is beneficial to subsequent processing and application; in addition, the peel strength value will increase, making it more durable during use; finally, improve production efficiency, reduce production costs, and is beneficial to large-scale production. Description of the Drawings

[0027] Figure 1 is a scanning electron microscope image of the copper foil prepared in Example 1 after being corroded by the ferric chloride corrosion solution; Figure 2 is a scanning electron microscope image of the copper foil prepared in Comparative Example 1 after being corroded by the ferric chloride corrosion solution; Figure 3It is a scanning electron microscope image of the copper foil prepared in Comparative Example 2 after being etched with a ferric chloride etching solution. Detailed implementation mode

[0028] The present invention will be further described below in conjunction with embodiments.

[0029] Embodiment 1 The method for improving the corrosion resistance of the copper foil surface by using a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in Embodiment 1 of the present invention 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 absolute ethanol is added and stirred at room temperature. After the reaction is completed, it is cooled to room temperature, and the crude product of 2-mercaptobenzothiazole is obtained by filtration. Finally, it is washed with deionized water and dried to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution Cerium nitrate hexahydrate is placed in an oven to be dried to obtain pure cerium nitrate monomer, and then the pure cerium nitrate monomer is dissolved in absolute 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 stirred at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor; (4) Preparation of electrodeposited copper foil ① Copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydithiopropane sulfonate (SPS) and sodium 3-mercapto-1-propanesulfonate (MPS) are mixed evenly to prepare an electrolyte; ② The copper foil is cut into sheets, then wiped and cleaned. The wiped copper foil is used as the cathode, and the platinum electrode is used as the anode, and placed in the electrolyte prepared in step ① for electrodeposition, and finally washed and dried to prepare an electrodeposited copper foil; (5) Corrosion inhibition treatment of copper foil ① The electrodeposited copper foil is cleaned to remove oil and oxides on the surface; ② The cleaned copper foil is immersed in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time, taken out after soaking, rinsed with deionized water, and then dried at low temperature to prepare a copper foil with corrosion inhibition.

[0030] Among them: 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 ethanol to o-aminothiophenol is 65:1.

[0031] In step (1), the stirring reaction time is 6.5 h.

[0032] In step (1), it is washed 3 times with deionized water, the drying temperature is 75 °C, and the drying time is 5.5 h.

[0033] In step (2), the drying temperature is 110 °C, and the drying time is 2 h.

[0034] In step (2), when preparing the cerium nitrate solution, the stirring reaction is carried out at room temperature, the stirring reaction time is 0.5 h, and the concentration of the prepared cerium nitrate solution is 10 g / L.

[0035] In step (3), the mass ratio of 2-mercaptobenzothiazole to the volume of the cerium nitrate solution is 1:10.5, with the unit of g / mL.

[0036] In step (3), the stirring reaction temperature is 35 °C, and the stirring reaction time is 1 h.

[0037] 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 polydithiopropane sulfonate is 1.0 mg / L, and the concentration of 3-mercapto-1-propanesulfonic acid sodium is 1.5 mg / L.

[0038] The copper foil described in step (4) ② is a rolled copper foil with a thickness of 12 μm, which is cut into a sheet with a size of 6.5 cm * 14 cm.

[0039] The wiping reagent used in the wiping and cleaning in step (4) ② is anhydrous ethanol, which is dropped on the gauze to wipe off the impurities on the surface of the original copper foil.

[0040] In step (4) ②, the distance between the cathode and the anode during electroplating is 10 cm, and the current density is 2.8 A / dm 2 , and the deposition time is controlled within 2 min.

[0041] In step (4) ②, the cleaning and drying are carried out using ethanol as the cleaning reagent, and the sample is cleaned cleanly by ultrasonic waves. The drying time at room temperature is 0.5 h, and the ultrasonic power is 30 W.

[0042] In step (5) ①, it is first washed 3 times with deionized water, and then washed 2 times with anhydrous ethanol.

[0043] In step (5) ②, the concentration of the 2-mercaptobenzothiazole-cerium composite inhibitor solution used is 3 g / L, with water as the solvent.

[0044] In step (5) ②, the soaking duration is 3 min, and the soaking temperature is 35 °C.

[0045] In step (5)②, the low-temperature drying temperature is 50 °C and the time is 7 min.

[0046] Example 2 The method for improving the corrosion resistance of the copper foil surface by using the 2-mercaptobenzothiazole-cerium composite inhibitor in this Example 2 consists of the following steps: (1) Preparation of 2-mercaptobenzothiazole Add o-aminothiophenol, carbon disulfide and sodium hydroxide solution into the reaction vessel, then add anhydrous ethanol and stir at room temperature. After the reaction is completed, cool to room temperature, filter to obtain the crude product of 2-mercaptobenzothiazole, and finally wash and dry with deionized water to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution Put cerium nitrate hexahydrate into the oven for drying to obtain pure cerium nitrate monomer, and then dissolve the pure cerium nitrate monomer in anhydrous ethanol to prepare cerium nitrate solution; (3) Preparation of 2-mercaptobenzothiazole-cerium composite inhibitor Add the 2-mercaptobenzothiazole prepared in step (1) into the cerium nitrate solution prepared in step (2), and stir at room temperature to prepare the 2-mercaptobenzothiazole-cerium composite inhibitor; (4) Preparation of electrodeposited copper foil ① Mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide propane sulfonate (SPS) and sodium 3-mercapto-1-propanesulfonate (MPS) evenly to prepare the electrolyte; ② Cut the copper foil into sheets, then wipe and clean it. Use the wiped copper foil as the cathode and the platinum electrode as the anode, put them into the electrolyte prepared in step ① for electrodeposition, and finally wash and dry to prepare the electrodeposited copper foil; (5) Corrosion inhibition treatment of copper foil ① Clean the electrodeposited copper foil to remove the oil and oxide on the surface; ② Immerse the cleaned copper foil in the 2-mercaptobenzothiazole-cerium composite inhibitor solution for a period of time, take it out after immersion, rinse it with deionized water, and then perform low-temperature drying to prepare the copper foil with corrosion inhibition.

[0047] Among them: 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 ethanol to o-aminothiophenol is 65:1.

[0048] The stirring reaction time in step (1) is 6.6 h.

[0049] In step (1), it was washed three times with deionized water, the drying temperature was 76 °C, and the drying time was 5.5 h.

[0050] In step (2), the drying temperature was 110 °C and the drying time was 2 h.

[0051] When preparing the cerium nitrate solution in step (2), the stirring reaction was carried out at room temperature, the stirring reaction time was 0.8 h, and the concentration of the prepared cerium nitrate solution was 10 g / L.

[0052] In step (3), the mass ratio of 2-mercaptobenzothiazole to the volume of the cerium nitrate solution was 1:10, with the unit of g / mL.

[0053] In step (3), the stirring reaction temperature was 38 °C and the stirring reaction time was 0.9 h.

[0054] In the electrolyte described in step (4) ①, the concentration of copper sulfate pentahydrate was 240 g / L, the concentration of sulfuric acid was 160.0 g / L, the concentration of sodium chloride was 0.124 g / L, the concentration of sodium polydithiopropanesulfonate was 1.0 mg / L, and the concentration of 3-mercapto-1-propanesulfonic acid sodium salt was 1.5 mg / L.

[0055] The copper foil described in step (4) ② was a rolled copper foil with a thickness of 12 μm, which was cut into a sheet of 6.5 cm * 14 cm.

[0056] The wiping reagent used for wiping and cleaning in step (4) ② was anhydrous ethanol, which was dropped on the gauze to wipe off the impurities on the surface of the original copper foil.

[0057] In step (4) ②, the distance between the cathode and the anode during electrodeposition was 10 cm, and the current density was 2.8 A / dm 2 , and the deposition time was controlled within 4 min.

[0058] In step (4) ②, the cleaning and drying used ethanol as the cleaning reagent, and the sample was cleaned clean by ultrasonic waves. The drying time at room temperature was 0.5 h, and the ultrasonic power was 40 W.

[0059] In step (5) ①, it was first washed three times with deionized water and then washed twice with anhydrous ethanol.

[0060] In step (5) ②, the concentration of the 2-mercaptobenzothiazole-cerium composite inhibitor solution used was 3 g / L, with water as the solvent.

[0061] In step (5) ②, the soaking duration was 4 min and the soaking temperature was 33 °C.

[0062] In step (5) ②, the temperature of low-temperature drying was 52 °C and the time was 6 min.

[0063] Example 3 The method for improving the corrosion resistance of the copper foil surface by using 2-mercaptobenzothiazole-cerium composite inhibitor in this Example 3 consists of the following steps: (1) Preparation of 2-mercaptobenzothiazole Add o-aminothiophenol, carbon disulfide and sodium hydroxide solution into a reaction vessel, then add anhydrous ethanol and stir at room temperature. After the reaction is completed, cool to room temperature, filter to obtain the crude product of 2-mercaptobenzothiazole, and finally wash with deionized water and dry to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution Put cerium nitrate hexahydrate into an oven to dry to obtain pure cerium nitrate monomer, and then dissolve the pure cerium nitrate monomer in anhydrous ethanol to prepare a cerium nitrate solution; (3) Preparation of 2-mercaptobenzothiazole-cerium composite inhibitor Add the 2-mercaptobenzothiazole prepared in step (1) into the cerium nitrate solution prepared in step (2), and stir at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite inhibitor; (4) Preparation of electrodeposited copper foil ① Mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydithiopropanesulfonate (SPS) and sodium 3-mercapto-1-propanesulfonate (MPS) evenly to prepare an electrolyte; ② Cut the copper foil into sheets, then wipe and clean it. Use the wiped copper foil as the cathode and the platinum electrode as the anode, put them into the electrolyte prepared in step ① for electrodeposition, and finally wash and dry to prepare an 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 Immerse the cleaned copper foil in the 2-mercaptobenzothiazole-cerium composite 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.

[0064] Among them: 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 ethanol to o-aminothiophenol is 65:1.

[0065] The stirring reaction time in step (1) is 6.8 h.

[0066] In step (1), wash with deionized water 4 times, the drying temperature is 78 °C, and the drying time is 5.5 h.

[0067] In step (2), the drying temperature is 110 °C and the drying time is 2 h.

[0068] When preparing the cerium nitrate solution in step (2), the stirring reaction is carried out at room temperature for 1 h, and the concentration of the prepared cerium nitrate solution is 10 g / L.

[0069] In step (3), the mass ratio of 2-mercaptobenzothiazole to the volume of the cerium nitrate solution is 1:11, with the unit of g / mL.

[0070] In step (3), the stirring reaction temperature is 40 °C and the stirring reaction time is 0.8 h.

[0071] 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 polydithiopropanesulfonate is 1.0 mg / L, and the concentration of 3-mercapto-1-propanesulfonic acid sodium salt is 1.5 mg / L.

[0072] The copper foil described in step (4) ② is a rolled copper foil with a thickness of 12 μm, which is cut into a sheet with a size of 6.5 cm * 14 cm.

[0073] The wiping reagent used for wiping and cleaning in step (4) ② is anhydrous ethanol, which is dropped on the gauze to wipe off the impurities on the surface of the original copper foil.

[0074] In step (4) ②, the distance between the cathode and the anode during electro-deposition is 10 cm, and the current density is 2.8 A / dm 2 , and the deposition time is controlled within 3 min.

[0075] In step (4) ②, the cleaning and drying is carried out using ethanol as the cleaning reagent, and the sample is cleaned thoroughly by ultrasonic waves. The drying time at room temperature is 0.5 h, and the ultrasonic power is 50 W.

[0076] In step (5) ①, it is first washed 3 times with deionized water and then 2 times with anhydrous ethanol.

[0077] In step (5) ②, the concentration of the 2-mercaptobenzothiazole-cerium composite inhibitor solution used is 3 g / L, with water as the solvent.

[0078] In step (5) ②, the soaking duration is 5 min and the soaking temperature is 30 °C.

[0079] In step (5) ②, the low-temperature drying temperature is 53 °C and the time is 5 min.

[0080] Comparative Example 1 The method for improving the corrosion resistance of the copper foil surface by using the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor described in Comparative Example 1 consists of the following steps: (1) Preparation of 2-mercaptobenzothiazole Add o-aminothiophenol, carbon disulfide, and sodium hydroxide solution into a reaction vessel, then add anhydrous ethanol and stir at room temperature. After the reaction, cool to room temperature, filter to obtain the crude product of 2-mercaptobenzothiazole, and finally wash with deionized water and dry to obtain 2-mercaptobenzothiazole; (2) Preparation of electrodeposited copper foil ① Mix copper sulfate pentahydrate, sulfuric acid, sodium chloride, sodium polydisulfide propane sulfonate (SPS), and 3-mercapto-1-propanesulfonic acid sodium (MPS) evenly to prepare an electrolyte; ② Cut the copper foil into sheets, then wipe and clean it. Use the wiped copper foil as the cathode and the platinum electrode as the anode, and place them in the electrolyte prepared in step ① for electrodeposition. Finally, wash and dry to obtain the electrodeposited copper foil; (3) Corrosion inhibition treatment of copper foil ① Clean the electrodeposited copper foil to remove oil and oxides on the surface; ② Immerse the cleaned copper foil in the 2-mercaptobenzothiazole corrosion inhibitor solution for a period of time. After immersion, take it out, rinse with deionized water, and then dry at low temperature to obtain the copper foil with corrosion inhibition properties.

[0081] Among them: 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 ethanol to o-aminothiophenol is 65:1.

[0082] The stirring reaction time in step (1) is 6.5 h.

[0083] In step (1), wash with deionized water 3 times, the drying temperature is 75 °C, and the drying time is 5.5 h.

[0084] 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 3-mercapto-1-propanesulfonic acid sodium is 1.5 mg / L.

[0085] The copper foil described in step (2) ② is a rolled copper foil with a thickness of 12 μm, which is cut into sheets of 6.5 cm * 14 cm.

[0086] In step (2) ②, the wiping reagent used for wiping and cleaning is anhydrous ethanol. Drop it on the gauze and wipe off the impurities on the surface of the original copper foil.

[0087] In step (2) ②, for electroplating, the distance between the cathode and the anode is 10 cm, and the current density is 2.8 A / dm 2 , and the deposition time is controlled at 2 minutes.

[0088] In step (2) ②, the cleaning and drying is carried out using ethanol as the cleaning reagent. Use ultrasonic waves to clean the sample thoroughly, and the drying time is 0.5 h at room temperature, and the ultrasonic power is 30 W.

[0089] In step (3) ①, first wash with deionized water 3 times, and then wash with anhydrous ethanol 2 times.

[0090] In step (3) ②, the concentration of the 2-mercaptobenzothiazole inhibitor solution used is 3 g / L, and water is used as the solvent.

[0091] In step (3) ②, the soaking duration is 3 minutes, and the soaking temperature is 35 °C.

[0092] In step (3) ②, the temperature for low-temperature drying is 50 °C, and the time is 7 minutes.

[0093] Comparative Example 2 The method for improving the corrosion resistance of the copper foil surface using the 2-mercaptobenzothiazole-cerium composite inhibitor described in this Comparative Example 2 consists of the following steps: (1) Preparation of 2-mercaptobenzothiazole Add o-aminothiophenol, carbon disulfide and sodium hydroxide solution to the reaction vessel, then add anhydrous ethanol and stir at room temperature. After the reaction is completed, cool to room temperature, filter to obtain the crude product of 2-mercaptobenzothiazole, and finally wash and dry with deionized water to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution Put cerium nitrate hexahydrate in the oven to dry to obtain pure cerium nitrate monomer, and then dissolve the pure cerium nitrate monomer in anhydrous ethanol to prepare a cerium nitrate solution; (3) Preparation of 2-mercaptobenzothiazole-cerium composite inhibitor Add the 2-mercaptobenzothiazole prepared in step (1) to the cerium nitrate solution prepared in step (2), and stir at room temperature to prepare a 2-mercaptobenzothiazole-cerium composite inhibitor; (4) Corrosion inhibition treatment of copper foil ① Cut the copper foil into sheets, clean it, and remove the oil and oxides on the surface; ② Immerse the cleaned copper foil in a 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution for a period of time. After the immersion, take it out, rinse it thoroughly with deionized water, and then perform low-temperature drying to obtain a copper foil with corrosion inhibition properties.

[0094] Among them: 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 ethanol to o-aminothiophenol is 65:1.

[0095] In step (1), the stirring reaction time is 6.5 h.

[0096] In step (1), it is washed 3 times with deionized water, the drying temperature is 75 °C, and the drying time is 5.5 h.

[0097] In step (2), the drying temperature is 110 °C and the drying time is 2 h.

[0098] In step (2), when preparing the cerium nitrate solution, the stirring reaction is carried out at room temperature, the stirring reaction time is 0.5 h, and the concentration of the prepared cerium nitrate solution is 10 g / L.

[0099] In step (3), the mass ratio of 2-mercaptobenzothiazole to the volume of the cerium nitrate solution is 1:10.5, with the unit of g / mL.

[0100] In step (3), the stirring reaction temperature is 35 °C and the stirring reaction time is 1 h.

[0101] In step (4)①, the copper foil is a rolled copper foil with a thickness of 12 μm, which is cut into a sheet with a size of 6.5 cm * 14 cm.

[0102] In step (4)①, it is first washed 3 times with deionized water, and then washed 2 times with absolute ethanol.

[0103] In step (4)②, the concentration of the 2-mercaptobenzothiazole-cerium composite corrosion inhibitor solution used is 3 g / L, with water as the solvent.

[0104] In step (4)②, the immersion duration is 3 min and the immersion temperature is 35 °C.

[0105] In step (4)②, the low-temperature drying temperature is 50 °C and the time is 7 min.

[0106] The 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, and then Tafel and AC impedance spectroscopy tests were performed in the system, respectively. The AC impedance spectrum was fitted by ZView software to obtain Rs and Rct data. Tables 1 and 2 are the test results. As shown in Table 1, compared with Comparative Example 2 (MBT-Ce without deposition) and Comparative Example 1 (MBT), Example 1-3 (MBT-Ce) has a smaller corrosion current value, and the introduction of MBT-Ce effectively inhibits the electrochemical corrosion activity on the surface of the copper foil. As shown in Table 2, the electrolyte solution resistance (Rs) and charge transfer resistance (Rct) in Examples 1-3 have higher resistance values. Compared with Comparative Example 1, the significant increase in Rct in Example 1-3 indicates that the protective film formed by MBT-Ce on the copper surface can effectively hinder the charge transfer process, thereby greatly improving the corrosion resistance of the system. Compared with Comparative Example 2, the Rct value of MBT-Ce after deposition in Examples 1-3 is much higher than that of MBT-Ce without deposition. This phenomenon can be attributed to the microstructural regulation effect given by the electrodeposition copper deposition technology. The electrodeposition copper deposition technology increases the surface active site density and promotes the adsorption capacity of MBT-Ce molecules at the interface. The two work together to eventually 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 the corrosive medium through the physical barrier effect, providing a double guarantee for the long-term stability of the copper foil in harsh environments.

[0107] Table 1 Corrosion current test results of copper foil prepared in Examples 1-3 and Comparative Examples 1-2

[0108] Table 2 Rs and Rct data of the copper foil prepared in Example 1-3 and Comparative Example 1-2 obtained by AC impedance testing

[0109] Figures 1-3 In Example 1, Comparative Example 1 and Comparative Example 2, respectively, 5g FeCl 3 +25ml hydrochloric acid +100ml anhydrous ethanol) for 10s. Figure 1 and Figure 2 , Figure 2 The deeper the holes, 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 3In appearance, its surface has a relatively high flatness and a relatively low density of active sites. The SEM image shows that the inhibitor is distributed in an island shape, and there are obvious uncovered gaps at the interface, resulting in the rapid penetration of the corrosive medium along the defects and the formation of shallow pitting corrosion pits. The electroplating process constructs a copper layer with a high roughness, and the surface presents a uniform nanoscale convex structure, such as Figure 1 , which has a higher surface roughness and more active sites on the surface, facilitating the adsorption of MBT-Ce. The MBT-Ce molecules form strong chemical adsorption with the copper surface through the thiol group (-SH), and the hydrolysis products of cerium ions (Ce 3+ ) are used to fill the micropores of the deposition layer, ultimately forming a thick and dense composite film. This synergistic effect of MBT-Ce and the electroplated copper layer will make the distribution of MBT-Ce denser and the corrosion resistance better.

Claims

1. A method for improving the corrosion resistance of copper foil surface by using 2-mercaptobenzothiazole-cerium composite corrosion inhibitor, characterized in that: It consists of the following steps: (1) Preparation of 2-mercaptobenzothiazole Add o-aminothiophenol, carbon disulfide and sodium hydroxide solution into a reaction container, then add anhydrous ethanol and stir to react at room temperature, cool to room temperature after the reaction is completed, filter to obtain a crude 2-mercaptobenzothiazole, and finally wash with deionized water and dry to obtain 2-mercaptobenzothiazole; (2) Preparation of cerium nitrate solution The cerium nitrate hexahydrate is placed in an oven for drying 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 and reacted at room temperature 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 propane sulfonate and sodium 3-mercapto-1-propane sulfonate to prepare an electrolyte; ② Cut the copper foil into sheets, wipe and clean them, use the wiped copper foil as the cathode and the platinum electrode as the anode, put them into the electrolyte prepared in step ① for electrodeposition, and finally wash and dry them to prepare the 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.

2. The method for improving the corrosion resistance of the 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 the 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 the 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 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: 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 step (3), the stirring reaction temperature is 35-40° C., and the stirring reaction time is 0.8-1 h.

6. The method for improving the corrosion resistance of copper foil surface by using 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: 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.

7. The method for improving the corrosion resistance of copper foil surface by using 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 cleaning in step (4) ② is anhydrous ethanol, which is dropped on gauze to wipe off impurities on the original surface of the copper foil.

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

9. The method for improving the corrosion resistance of copper foil surface by using 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: In step (5) ①, the surface is first washed with deionized water for 3 times, and then washed with anhydrous ethanol for 2 times; 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.

10. The method for improving the corrosion resistance of copper foil surface by using 2-mercaptobenzothiazole-cerium composite corrosion inhibitor according to claim 1, characterized in that: In step (5) ②, the soaking time is 3-5 min, 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 min.

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