An anti-oxidation method for electrolytic copper foil

Abstract

The present invention discloses an anti-oxidation method for electrolytic copper foil, which relates to the technical field of copper foil production. The method includes the following steps: S1: drying; S2: slitting; S3: end face protection, adding a protection structure to the end face formed after slitting on the copper foil to separate the slitting end face from air and water vapor, and the protection structure is a stretching film layer and an EPE protection layer that are sequentially attached to the end face position; S4: storing and cooling, placing the copper foil in an environment with a temperature of 20-26°C and a humidity <70% for at least 24 hours. During the slitting process of the copper foil and during the cooling time after slitting, the end face of the copper foil is protected to ensure that the surrounding of the copper foil end face is isolated from air and water vapor, avoiding the condensation of water vapor on the end face of the copper foil during the cooling process after cutting and the oxidation of the copper foil end face caused by the cooperation with air. After the copper foil is completely cooled to room temperature, its edge position is then sealed and packaged, improving the product quality of the copper foil.

Description

Technical Field

[0001] The present invention relates to the technical field of copper foil production, and particularly to an anti-oxidation method for electrolytic copper foil. Background Art

[0002] Copper foil is one of the important materials for manufacturing copper clad laminates and PCBs. Similar to thin tin foil, it is a thin sheet generally with a thickness of less than 0.1 mm and is widely used in electronic devices such as circuit boards. Industrial copper foils are usually divided into two categories: rolled copper foil and electrolytic copper foil. Rolled copper foil has good ductility, while electrolytic copper foil has the advantage of low manufacturing cost and is suitable for large-scale production.

[0003] Electrolytic copper foil refers to a metal copper foil produced by an electrolysis method using copper material as the main raw material. The copper material is dissolved to make a copper sulfate electrolytic solution, and then the copper sulfate electrolyte is electro-deposited into a foil through direct current in a special electrolysis device, and then a series of treatments such as surface roughening and anti-oxidation treatment are carried out on it, and finally it is made into a finished product after slitting and testing.

[0004] After the current copper foil production is wound, it needs to be slit to cut the copper foil into the target size and shape.

[0005] For example, the method for synchronous slitting of multiple rolls of electrolytic copper foil disclosed in the Chinese patent with the publication number of CN1272151C mainly includes the following steps:

[0006] 1. Unroll the copper foil roll at the uncoiling place; 2. Install the lower knife group on the lower knife shaft and install the upper knife on the upper knife shaft;

[0007] 3. The copper foil passes through the guide shaft and the lower part of the drive shaft, passes between the lower knife shaft and the upper knife shaft, and between the drive rubber roll and the pressing rubber roll, and is pulled to the winding place through the upper part of the tension shaft;

[0008] 4. Adjust the upper knife shaft so that the depth of the upper blade entering the lower knife slot is 1.0 - 1.5 mm, and lock the upper knife holder; 5. The uncoiling tension is 80 - 100 N for every 100 KG of copper foil, and the winding tension is 25 - 35 N for every 100 mm of the foil width on the winding shaft;

[0009] 6. Install the paper core on the winding shaft, alternately pass the copper foil cut by each knife group through the upper and lower tension shafts, and respectively stick it to the paper cores of the upper and lower winding shafts, and lead the ear material to the ground; 7. Start the slitter and stop and unwind the roll until the required length.

[0010] This slitting method can synchronously slit multiple rolls of copper foil at one time, improving the yield and production efficiency of copper foil. However, during the slitting process of copper foil, due to the baking and heating before slitting and the friction cutting with the blade, a large amount of heat will be generated at the end face position of the copper foil, causing the temperature of the copper foil end face to be much higher than the ambient temperature and damaging the anti-oxidation layer here. During the cooling process of the copper foil after slitting, water vapor condenses on the end face, promoting end face oxidation, making the cut copper foil oxidize and change color, not meeting the usage standards. Summary of the Invention

[0011] In view of the above technical problems, the present invention overcomes the shortcomings of the prior art and provides an anti-oxidation method for electrolytic copper foil.

[0012] To solve the above technical problems, the present invention provides an anti-oxidation method for electrolytic copper foil.

[0013] Technical effect: During the slitting process of the copper foil and within the cooling time after slitting, the end face of the copper foil is protected to ensure that the surrounding of the copper foil end face is isolated from air and water vapor, avoiding the condensation of water vapor on the end face of the copper foil during the cooling process after cutting and the oxidation of the copper foil end face caused by cooperation with air. Until the copper foil is completely cooled to room temperature, then the edge position is sealed and packaged, improving the product quality of the copper foil.

[0014] The further limited technical solution of the present invention is: 1. An anti-oxidation method for electrolytic copper foil, including the following steps:

[0015] S1: Drying, placing the copper foil to be cut in a constant-temperature oven for baking and heating;

[0016] S2: Slitting, lifting the copper foil together with the constant-temperature oven to the vicinity of the slitter, and quickly lifting out the copper foil and placing it on the slitter to complete slitting. The slitting process is carried out under the surrounding of a protective gas;

[0017] S3: End-face protection, adding a protection structure to the end face formed after slitting the copper foil to separate the slitting end face from air and water vapor;

[0018] S4: Storage and cooling, lifting the copper foil with the added protection mechanism into a storage wooden box and placing it in an environment with a temperature of 20 - 26°C and a humidity < 70% for at least 24 hours until the copper foil is cooled to room temperature and then sealing the end face of the copper foil;

[0019] The protection structure is a stretch film layer and an EPE protection layer that are successively attached to the end face position.

[0020] Furthermore, the protective gas in step S3 is nitrogen or carbon dioxide or argon or a mixture of at least two gases. The protective gas is blown synchronously with the cutter of the slitter to the copper foil slitting position, and the temperature of the protective gas is 0 - 20°C.

[0021] For the anti-oxidation method for electrolytic copper foil described above, a stretching film layer is attached to the cutting end face of the copper foil, an EPE protective layer covers the stretching film layer, and a zinc sheet arranged in conformity with the cutting end face is further provided between the stretching film layer and the cutting end face.

[0022] For the anti-oxidation method for electrolytic copper foil described above, a paraffin protective layer is coated on the stretching film layer, and the paraffin protective layer is attached and covers the cutting end face of the copper foil.

[0023] For the anti-oxidation method for electrolytic copper foil described above, in step S4, the optimal conditions for the wooden box storage environment are: temperature: 22 °C, humidity < 40%, and a moisture absorbent is provided in the wooden box, and the moisture absorbent is coffee grounds or moisture-absorbing silica gel or calcium chloride particles.

[0024] For the anti-oxidation method for electrolytic copper foil described above, in step S3, before setting the protection structure, a layer of anti-oxidation liquid is evenly sprayed on the cutting end face of the copper foil. During the spraying process, the copper foil is in an energized state. After the oxidation liquid is sprayed and stays for 5 - 8 s, it is wiped off, and then the protection mechanism is set.

[0025] For the anti-oxidation method for electrolytic copper foil described above, the anti-oxidation liquid therein includes substances with the following weight fractions:

[0026]

[0027]

[0028] Among them, the concentration of the NaCl solution is 3%.

[0029] For the anti-oxidation method for electrolytic copper foil described above, when preparing the anti-oxidation liquid, first divide benzotriazole into two equal parts, and respectively mix it with corresponding amounts of sodium tungstate and sodium molybdate in the corresponding amounts of NaCl solution, then mix the two solutions and stir for 1 - 2 min, slowly add triethanolamine, adjust the pH value of the solution to between 7.5 and 8, add a cerium ion solution, and stir to obtain the finished anti-oxidation liquid.

[0030] The beneficial effects of the present invention are:

[0031] (1) In the present invention, after the electrolytic copper foil is slit, the reason for the easy oxidation and discoloration of the end face is that the copper foil needs to be heated before cutting. At the same time, a large amount of heat is generated by the friction between the end face and the cutting tool during the cutting process, and the original anti-oxidation layer is damaged. Direct packaging will cause air to remain, and water vapor will condense on the end face under high-temperature conditions, thus forming the oxidation of the end face. In the present invention, after the copper foil is dried, it is quickly lifted together with the oven and the copper foil to the vicinity of the slitter for slitting, which can avoid a large drop in temperature and a large amount of water vapor condensation in the air during the transfer of the copper foil. There is a protective gas during the slitting process. The protective gas can expel the air and water vapor around the cutting end face, avoid the condensation of water vapor and the accumulation of oxygen in the high-temperature state, and thus prevent the oxidation of the slitting end face. A stretch film layer and an EPE protective layer are added to the end face after slitting, which can separate the end face from air and water vapor. Then the copper foil is placed in a wooden box for storage and cooling. Under the conditions of a temperature of 20 - 26 °C and a humidity of < 70%, the copper foil can quickly cool down and is not easily oxidized. Finally, it is sealed to achieve an excellent end-face protection effect;

[0032] (2) In the present invention, the protective gas used is nitrogen or carbon dioxide or argon or a mixture of at least two of the above gases. The costs of nitrogen and carbon dioxide are relatively low and the protection effects are good, while the cost of argon is slightly higher and the protection effect is more excellent. It will not cause pollution to the environment and is all suitable as the protective gas for copper foil cutting. Moreover, the masses of all three are greater than that of air. Therefore, after cutting, the protective gas can sink around the end face to provide continuous protection for the cutting end face. In addition, the temperature of the protective gas is relatively low, which can quickly cool the end face initially after the copper foil is cut, reduce the temperature of the copper foil end face, and further play a role in preventing oxidation;

[0033] (3) In the present invention, the stretch film layer is attached to the cutting end face of the copper foil, which can isolate the air and water vapor at the cutting end face position and remove the oxidation conditions of the copper foil. Placing a zinc sheet on the cutting end face can utilize the fact that the activity of metallic zinc is much greater than that of copper to provide electrochemical protection for the copper foil, which can avoid the oxidation of copper caused by the remaining air when the stretch film layer is attached to the end face position. Setting an EPE protective layer outside the stretch film layer can further isolate air and water vapor, and at the same time protect the stretch film layer to avoid damage to the stretch film layer during handling;

[0034] (4) In the present invention, a paraffin wax protective layer is coated on the stretch film layer, which can make the attachment of the stretch film layer to the cutting end face closer and improve the ability of the stretch film layer to isolate air and water vapor. When the copper foil is stored in a wooden box, a moisture absorbent is set in the wooden box, which can remove the water vapor content in the wooden box and further improve the anti-oxidation effect of the copper foil end face;

[0035] (5)In the present invention, before setting up the protection structure, an anti-oxidation liquid is sprayed on the cutting end face, and the spraying process is in an electrified state, which can quickly form a dense and ordered monolayer protective film on the cutting end face, effectively protecting the copper foil and preventing the oxidation of the copper foil end face. The purpose of wiping off the anti-oxidation liquid is to prevent the anti-oxidation liquid from continuously reacting slowly with the copper foil after the protection mechanism is added, resulting in a relatively large thickness of the protective film and affecting the quality of the copper foil. Specific Embodiments

[0036] To make the objectives, technical solutions and advantages of the present invention clearer, the following provides a detailed description in conjunction with specific embodiments. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0037] It should be noted that when an element is referred to as "fixedly provided on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to an element or there may be intermediate elements at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0039] An anti-oxidation method for electrolytic copper foil provided in this embodiment includes the following steps.

[0040] S1: Drying, placing the copper foil to be cut in a constant-temperature oven for baking and heating.

[0041] S2: Slitting, lifting the copper foil together with the constant-temperature oven to the vicinity of the slitting machine, and quickly lifting out the copper foil and placing it on the slitting machine to complete the slitting. The slitting process is carried out under the surrounding of a protective gas; the protective gas is nitrogen or carbon dioxide or argon or a mixture of at least two of the above gases. At the same time, the protective gas moves along with the cutter of the slitting machine and is blown to the position of the end face of the copper foil cut by the slitting machine, and the temperature of the protective gas is controlled at 0 - 20°C.

[0042] In this step, the protective gas can blow away the air around the cutting end face of the copper foil, protect the end face of the copper foil by virtue of its characteristic of being not easily reactive, and the relatively low gas temperature can also rapidly cool the end face, reducing the temperature of the copper foil end face to lower its activity and achieving the effect of anti-oxidation.

[0043] S3: End face protection. A protection structure is added to the end face formed after slitting on the copper foil to separate the slitting end face from air and water vapor. Before setting the protection structure, a layer of anti-oxidation liquid is evenly sprayed on the cutting end face of the copper foil. The copper foil is in an energized state during the spraying process. After the oxidation liquid is sprayed and stays for 5 - 8 s, it is wiped off, and then the protection mechanism is set.

[0044] The protection structure is a stretch film layer and an EPE protection layer that are successively attached to the end face position. The stretch film layer is attached to the cutting end face of the copper foil, the EPE protection layer covers outside the stretch film layer, and a zinc sheet arranged in conformity with the cutting end face is provided between the stretch film layer and the cutting end face. A paraffin protection layer is also coated on the stretch film layer, and the paraffin protection layer conforms to and covers the cutting end face of the copper foil.

[0045] In this step, the anti-oxidation liquid can form a dense protective film on the cutting end face of the copper foil under the energized condition. The protective film can be formed after the oxidation liquid is sprayed and stays for 5 - 8 s under the energized condition; setting the zinc sheet can implement electrochemical protection on the end face of the copper foil by virtue of the relatively high activity of metallic zinc. Finally, the attachment of the paraffin protection layer, the stretch film layer, and the setting of the EPE protection layer can isolate the contact between the copper foil end face and air and prevent the oxidation of the copper foil end face.

[0046] S4: Storage and cooling. The copper foil with the added protection mechanism is lifted into a storage wooden box and placed in an environment with a temperature of 20 - 26°C and a humidity < 70% for at least 24 h until the copper foil cools to room temperature, and then the end face of the copper foil is sealed; the optimal conditions for the storage environment of the wooden box are a temperature of 22°C and a humidity < 40%. A moisture absorbent is also provided in the wooden box, and the moisture absorbent is coffee grounds or moisture-absorbing silica gel or calcium chloride particles.

[0047] In this step, placing the copper foil and the wooden box under suitable temperature and humidity conditions can reduce the reaction conditions of the copper foil to achieve the purpose of anti-oxidation, and at the same time, the copper foil is cooled. Finally, sealing the copper foil can maintain the best quality and sealing effect of the copper foil. In addition, setting the moisture absorbent can keep the air in the wooden box dry and reduce the reaction conditions for the oxidation of the copper foil end face. Coffee grounds or moisture-absorbing silica gel or calcium chloride particles are all common low-cost moisture absorbents and will not affect the copper foil itself.

[0048] The anti-oxidation liquid used in this embodiment has a composition including the following substances in weight fractions:

[0049]

[0050]

[0051] Among them, the concentration of the NaCl solution is 3%.

[0052] When preparing the above anti-oxidation liquid, benzotriazole is first divided into two equal parts, and the same NaCl solution is also divided into two equal parts.

[0053] Then, one part of benzotriazole and the corresponding sodium tungstate are successively added to one part of the NaCl solution, and the other part of benzotriazole and the corresponding sodium molybdate are added to the other part of the NaCl solution. After corresponding stirring, the two mixed solutions are mixed and stirred for 1 - 2 minutes. At this time, the mixed solution is neutral.

[0054] Then, triethanolamine is slowly added to the mixed solution. Triethanolamine has weak alkalinity and will not react with any of the above substances. Therefore, triethanolamine can be used to adjust the pH value of the mixed solution to between 7.5 and 8.

[0055] Finally, the corresponding amount of cerium ion solution is added to the weakly alkaline mixed solution, and after stirring, the finished anti-oxidation liquid is obtained.

[0056] Since benzotriazole is a widely used corrosion inhibitor for copper and its alloys, it can effectively slow down the oxidation reaction of copper and its alloys. However, due to the poor water solubility of benzotriazole, it is not easy to form a protective film on the copper surface when used alone, and the corrosion inhibition performance is relatively unsatisfactory, and the corrosion inhibition efficiency is only 48 - 52%.

[0057] In the present invention, sodium tungstate and sodium molybdate are used in combination with benzotriazole. This compounding system has a good synergistic corrosion inhibition effect in the NaCl solution, and can greatly improve the corrosion inhibition efficiency for copper and its alloys. The corrosion inhibition efficiency of the solution formed after compounding for copper is increased to 88 - 92%.

[0058] In addition, cerium ions are added to this solution. Cerium ions can change the film-forming mechanism of benzotriazole itself on copper under weakly alkaline conditions, and increase the corrosion inhibition efficiency of the compounded solution to more than 98%, greatly improving the atmospheric corrosion resistance of the anti-oxidant to copper.

[0059] The present invention uses test copper sheets for immersion tests to measure the corrosion inhibition efficiency of the anti-oxidation liquid on metallic copper under different components.

[0060] The test method is as follows: Take a test copper sheet with a size of 20mm * 20mm and a thickness of 1mm, with a copper content of 99.50%. Polish the copper sheet, weigh it, and then suspend and immerse it in the anti-oxidation liquid with different compositions for 7 days at a temperature of (25 ± 1) °C. After taking out the sample, rinse it with deionized water. After natural drying, erase the corrosion products on the surface with an eraser, and finally clean and dry it with acetone, weigh it again, and calculate the corrosion efficiency of each system by the weight loss method.

[0061] The corrosion efficiency is calculated by the following formula:

[0062]

[0063] Where, v corr and are the corrosion rates with and without antioxidant respectively, and the calculation formula is:

[0064]

[0065] m 前 refers to the mass of the copper sheet before immersion, g; m 后 refers to the mass of the copper sheet after immersion; A refers to the area of the copper sheet, cm 2 ; t refers to the immersion time, d.

[0066] In the present invention, the influence of the anti-oxidation liquid with different contents of substances on the corrosion efficiency of the copper sheet is set. A total of 9 examples are set, and a comparative example is also set. The comparative example is a copper sheet not immersed in the anti-oxidation liquid.

[0067] Table 1 Table of examples with different substance contents

[0068]

[0069]

[0070] The corrosion inhibition efficiency of the obtained copper sheet is shown in Table 2.

[0071] Table 2 Table of corrosion inhibition efficiency of copper sheets immersed in anti-oxidation liquid with different substance contents

[0072]

[0073] It can be seen from Table 2 that the contents of benzotriazole and cerium ions are the factors that have the greatest influence on the corrosion inhibition efficiency of the copper sheet. Within a certain range, the higher the contents of benzotriazole and cerium ions, the stronger the corrosion inhibition efficiency of the copper sheet; while the increase in the contents of sodium tungstate and sodium molybdate will cause the corrosion inhibition efficiency of the copper sheet to first increase and then decrease. In summary, under the conditions of a benzotriazole content of 1.0 part, a sodium molybdate and sodium tungstate content of 25 parts, and a cerium ion content of 0.2 part, the corrosion inhibition rate of the copper sheet is the highest.

[0074] In the present invention, the oxidation conditions of copper foils under different step conditions in the anti-oxidation method steps of electrolytic copper foils were also tested. Similarly, a comparative example was set in the present invention, and the comparative example was a copper foil sample that was directly cooled and sealed after cutting.

[0075] The detection standard adopted in the present invention is GB / T 29847-2013 "Test Methods for Copper Foil for Printed Circuit Boards". The test methods adopted are as follows:

[0076] 1. Room temperature anti-oxidation performance test: Cut a copper foil specimen with dimensions of (250±0.1)mm*(250±0.1)mm, cut it into a specimen of (150±0.1)mm*(250±0.1)mm, roll it into a copper foil roll with the same diameter. After being treated by the anti-oxidation method in the present invention, store it at a temperature of 80°C and a relative humidity of 90% for 24h. After taking it out, observe the oxidation points on the cut end face of the copper foil and record the number of oxidation points.

[0077] 2. High-temperature anti-oxidation performance test: Cut a copper foil specimen with dimensions of (250±0.1)mm*(250±0.1)mm, cut it into a specimen of (150±0.1)mm*(250±0.1)mm, roll it into a copper foil roll with the same diameter. After being treated by the anti-oxidation method in the present invention, then hang it in an air-circulating constant-temperature oven, keep it at a temperature of (140±2)°C for 15min and then take it out, and observe the oxidation and color change of the cut end face of the copper foil. If oxidation occurs, the end face of the copper foil will change from golden yellow to tawny or even black.

[0078] Ten embodiments were set in the present invention, which are respectively:

[0079] Embodiment 10 includes the following steps:

[0080] S1: Drying, placing the copper foil to be cut in a constant-temperature oven for baking and heating;

[0081] S2: Slitting, hanging the copper foil together with the constant-temperature oven around the slitter, and quickly lifting the copper foil out and placing it on the slitter to complete the slitting. The slitting process is carried out under the surrounding of a protective gas;

[0082] S3: End face protection, spraying an anti-oxidation liquid on the end face formed after slitting the copper foil, and adding a protection structure. The protection mechanism includes a zinc sheet, a paraffin wax protection layer, a stretch film layer and a pearl cotton protection layer;

[0083] S4: Storage and cooling, hanging the copper foil with the added protection mechanism into a storage wooden box, placing a moisture absorbent in the wooden box, and storing it in an environment with a temperature of 20°C and a relative humidity of 40% for 24h.

[0084] Embodiment 11 is different from Embodiment 10 in that there is no protective gas during the slitting process.

[0085] Example 12, which is different from Example 10 in that no anti-oxidation liquid is sprayed after slitting.

[0086] Example 13, which is different from Example 10 in that there is no zinc sheet in the protection mechanism.

[0087] Example 14, which is different from Example 10 in that there is no paraffin wax protective layer in the protection mechanism.

[0088] Example 15, which is different from Example 10 in that there is no moisture absorbent in the wooden box.

[0089] Example 16, which is different from Example 10 in that the storage environment of the wooden box is at a temperature of 22 °C and a relative humidity of 40%.

[0090] Example 17, which is different from Example 10 in that the storage environment of the wooden box is at a temperature of 25 °C and a relative humidity of 40%.

[0091] Example 18, which is different from Example 10 in that the storage environment of the wooden box is at a temperature of 20 °C and a relative humidity of 60%.

[0092] Example 19, which is different from Example 10 in that the storage environment of the wooden box is at a temperature of 20 °C and a relative humidity of 70%.

[0093] After testing, the normal-temperature anti-oxidation performance and high-temperature anti-oxidation performance of the copper foil cutting end face are shown in Table 3.

[0094] Table 3 Number of oxidation points under normal-temperature anti-oxidation test and discoloration under high-temperature anti-oxidation test of copper foil cutting end face

[0095]

[0096]

[0097] As can be seen from Table 3, the protective gas during slitting, spraying oxidation liquid after slitting, setting zinc sheets, paraffin wax protective layer, and the temperature and relative humidity of the storage wooden box all affect the oxidation of the copper foil end face. Among them, the most influential are the protective gas during slitting and the spraying of oxidation liquid after slitting.

[0098] During the slitting process of the copper foil and during the cooling time after slitting, the end face of the copper foil is protected in the present invention, ensuring that the surrounding of the copper foil end face is isolated from air and water vapor, avoiding the condensation of water vapor on the end face of the copper foil during the cooling process after cutting and the oxidation of the copper foil end face caused by the cooperation with air. After the copper foil is completely cooled to the normal temperature state, its edge position is then sealed and packaged, improving the product quality of the copper foil.

[0099] In addition to the above embodiments, the present invention may have other implementation manners. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. An anti-oxidation method for electrolytic copper foil, characterized in that, It includes the following steps: S1: Drying. Place the copper foil to be cut in a constant-temperature oven for baking and heating. S2: Slitting. Lift the copper foil together with the constant-temperature oven around the slitter, and quickly lift out the copper foil and place it on the slitter to complete slitting. The slitting process is carried out under the surrounding of a protective gas. S3: End face protection. Add a protection structure to the end face formed after slitting the copper foil to separate the slitting end face from air and water vapor. In step S3, before setting the protection structure, first evenly spray a layer of anti-oxidation liquid on the cutting end face of the copper foil. The copper foil is in an energized state during the spraying process. After the anti-oxidation liquid is sprayed and stays for 5 - 8 s, wipe it off, and then set the protection mechanism. The anti-oxidation liquid includes the following substances by weight fraction: Benzotriazole 0.8 - 1 part Sodium tungstate 20 - 30 parts Sodium molybdate 20 - 30 parts Cerium ion solution 0.1 - 0.2 part Triethanolamine 15 - 35 parts NaCl solution 100 parts, where the concentration of the NaCl solution is 3%. S4: Storage and cooling. Lift the copper foil with the added protection mechanism into a storage wooden box and place it in an environment with a temperature of 20 - 26°C and a humidity < 70% for at least 24 h until the copper foil cools to room temperature, and then seal the end face of the copper foil. The protection structure is a stretch film layer and an EPE protection layer that are sequentially attached to the end face position.

2. The anti-oxidation method for electrolytic copper foil according to claim 1, characterized in that: The protective gas in step S3 is nitrogen or carbon dioxide or argon or a mixture of at least two of the gases. The protective gas is blown synchronously with the cutter of the slitter to the copper foil slitting position, and the temperature of the protective gas is 0 - 20°C.

3. A method for preventing oxidation of electrolytic copper foil according to claim 1, characterized in that: The stretch film layer is attached to the cutting end face of the copper foil, the EPE protection layer covers the stretch film layer, and a zinc sheet attached to the cutting end face is also provided between the stretch film layer and the cutting end face.

4. A method for preventing oxidation of electrolytic copper foil according to claim 1, characterized in that: A paraffin protection layer is coated on the stretch film layer, and the paraffin protection layer is attached and covers the cutting end face of the copper foil.

5. A method for preventing oxidation of electrolytic copper foil according to claim 1, characterized in that: In step S4, the best conditions for the wooden box storage environment are: temperature: 22°C, humidity < 40%, and a moisture absorbent is provided in the wooden box. The moisture absorbent is coffee grounds or moisture-absorbing silica gel or calcium chloride particles.

6. A method for preventing oxidation of electrolytic copper foil according to claim 1, characterized in that: When preparing the anti-oxidation liquid, first divide the benzotriazole into two equal parts and mix them with the corresponding parts of sodium tungstate and sodium molybdate in the corresponding parts of the NaCl solution respectively. Then mix the two solutions and stir for 1 - 2 min, slowly add triethanolamine, adjust the pH value of the solution to between 7.5 and 8, and add the cerium ion solution and stir to obtain the finished anti-oxidation liquid.

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