Hydrocarbon degreasing surface cleaning process for copper foil

Abstract

The invention belongs to the technical field of metal surface treatment, and discloses a degreasing cleaning process of a copper foil. The degreasing cleaning technology of the copper foil comprises the following steps that a degreasing cleaning agent is sprayed to the surface of the copper foil for cleaning treatment, a passivating agent is sprayed to the surface of the copper foil for surface passivating treatment, drying is conducted, and cleaning is completed; the degreasing cleaning process of the copper foil further comprises the steps of separating, purifying and recycling a waste liquid mixture generated in the cleaning process, a hydrocarbon cleaning agent and a passivating agent are independently recycled through fractional distillation, and efficient and environment-friendly degreasing cleaning of the thin copper foil is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of metal surface treatment, and in particular to a carbon-hydrogen degreasing surface cleaning process for copper foil. Background Art

[0002] The production process of rolled copper foil is complex and has high technical content. The degreasing and cleaning process is an important part of the production of rolled copper foil. The first is to remove the oil on the surface of the rolled copper foil, and the second is to perform surface anti-oxidation treatment on the rolled copper foil. This problem is closely related to the degreasing method and process requirements of the rolled copper foil. Currently, the commonly used degreasing and cleaning methods include alkaline solution cleaning, organic solvent cleaning, etc. The degreasing and cleaning process in the copper foil production line, especially in the production process of high-precision rolled copper foil, can improve the surface cleanliness of the product and provide a good foundation for subsequent processing.

[0003] In the prior art, the cleaning process and technology generally only include the steps of cleaning, passivating and drying the copper foil. However, the cleaning agents and passivating agents used in the prior art are mostly organic compounds that cause great environmental pollution. If only drying is used to remove the above substances on the surface of the copper foil, the organic flow into the air will cause great pollution. There are few technical records on the recycling of cleaning agents and passivating agents in the prior art. Summary of the invention

[0004] In order to solve the above technical problems, a cleaning process flow is developed which can independently recycle and regenerate cleaning agents, passivating agents and rolling oils during the copper foil cleaning process, while also meeting the needs of process concentration and reducing energy consumption, thereby achieving the technical effect of efficient and environmentally friendly degreasing and cleaning of thin copper foil. The present application provides a hydrocarbon degreasing surface cleaning process for copper foil.

[0005] In a first aspect, the present application provides a degreasing and cleaning process for copper foil, comprising at least the following steps: S1. Send the produced copper foil to the cleaning work area, spray the degreasing cleaning agent on the surface of the copper foil for cleaning, and use a squeezing roller to squeeze the cleaned copper foil; S2, sending the copper foil squeezed in step S1 into the passivation work area, spraying the passivating agent on the surface of the copper foil for surface passivation treatment, and squeezing the passivated copper foil with a squeezing roller; S3, sending the copper foil squeezed out in step S2 into an oven for drying, and then performing hole detection, and the copper foil cleaning is completed.

[0006] Optionally, in step S1, the amount of degreasing cleaning agent used is 80-140 g / m 2 .

[0007] Optionally, in step S1, the action time of the degreasing cleaning agent on the surface of the copper foil is controlled to be 20-40 minutes.

[0008] By adopting the above technical solution, after the degreasing cleaning agent is sprayed onto the surface of the copper foil, the hydrocarbon cleaning agent of the degreasing cleaning agent is an alkane or isoalkane solvent with a carbon number of 6 to 13, which can dissolve the rolling oil on the surface of the copper foil. At the same time, after the cleaning is completed, a layer of oil film can be formed to prevent the surface of the copper foil from being further oxidized.

[0009] Optionally, in step S2, the amount of the passivating agent is 30-60 g / m 2 .

[0010] Optionally, in step S2, the action time of the passivating agent on the copper foil surface is controlled to be 6-10 minutes.

[0011] Optionally, the degreasing and cleaning process of the copper foil also includes step S4, and the step S4 includes the following steps: collecting the liquid squeezed by the squeezing roller in step S1 and the liquid squeezed by the squeezing roller in step S2, mixing them to obtain a liquid mixture, distilling the liquid mixture, and separating to obtain hydrocarbon cleaning agent, passivating agent, and rolling oil.

[0012] Optionally, in step S4, the hydrocarbon cleaning agent, the passivating agent, and the rolling oil are separated by utilizing the different boiling points. In step S4, the distillation comprises the following steps: Add the liquid mixture and place it in a distillation device, raise the temperature to 150-210°C, keep it warm for 2-4 hours and continue stirring, and condense and reflux at the same time to obtain a separated degreasing cleaning agent; move the liquid mixture from which the degreasing cleaning agent is separated into a new distillation device, raise the temperature to 220-275°C, keep it warm for 2-4 hours and continue stirring, and condense and reflux at the same time to obtain a separated passivating agent; the main component of the liquid mixture from which the degreasing cleaning agent and the passivating agent are separated is rolling oil, which is recovered and purified for reuse.

[0013] By adopting the above technical scheme, the distillation difference of each component in the liquid mixture is used for separation. The liquid mixture is first indirectly heated in a vacuum environment to vaporize the hydrocarbon cleaning agent. As the hydrocarbon vapor overflows and undergoes processes such as heat exchange and condensation, new, pure hydrocarbon cleaning agent is regenerated, thereby realizing continuous distillation, recycling and cost reduction of the hydrocarbon cleaning agent and achieving "zero" emissions of the hydrocarbon cleaning agent.

[0014] Optionally, the degreasing cleaning agent comprises the following raw materials in parts by weight: 50-80 parts of hydrocarbon cleaning agent, 5-15 parts of methyl methacrylate, 10-20 parts of alcohol ether compounds, and 5-8 parts of fatty alcohol polyoxyethylene ether phosphate.

[0015] By adopting the above technical solution, hydrocarbon cleaning agents can effectively dissolve and emulsify the dirt on the surface of copper foil based on the principle that like dissolves like, such as grease, wax, and organic pollution, to achieve a cleaning effect. Methyl methacrylate and hydrocarbon cleaning agents work synergistically to improve the cleaning agent's ability to dissolve pollutants. At the same time, methyl methacrylate can form a protective film during the cleaning process using its own modeling to reduce secondary contamination on the surface of copper foil. Alcohol ether compounds reduce the surface tension of the liquid, allowing the degreasing cleaning agent to spread more evenly on the surface of the copper foil. At the same time, their own emulsification effect helps to peel off dirt such as grease from the surface of the copper foil and suspend it in the degreasing cleaning agent, thereby removing dirt.

[0016] Optionally, the hydrocarbon cleaning agent is a normal alkane solvent or an isoalkane solvent having a distillation range of 150-210°C.

[0017] Optionally, the normal alkane solvent is selected from alkanes having 6 to 13 carbon atoms.

[0018] Optionally, the isoalkane solvent is selected from alkane isomers having 6 to 13 carbon atoms.

[0019] Optionally, the alcohol ether compound includes one or more of propylene glycol butyl ether, dipropylene glycol butyl ether, dipropylene glycol methyl ether, propylene glycol n-propyl ether, and dipropylene glycol n-propyl ether.

[0020] Optionally, the passivating agent comprises the following components in parts by weight: 80-85 parts of imidazole derivatives, 10-15 parts of alkyl alcohols, 0.1-0.5 parts of tetrasodium ethylenediaminetetraacetic acid, and deionized water as a supplement.

[0021] By adopting the above technical solution, imidazole derivatives are the main active ingredients in the passivator, which can form a stable coordination bond with the copper surface and form a dense protective film on the surface of the copper foil to prevent oxidation and corrosion. Alkyl alcohols, as solvents and auxiliary ingredients, can help imidazole derivatives to better disperse and adsorb on the surface of the copper foil, while enhancing the wettability of the passivator, causing the passivator to evenly cover the surface of the copper foil and enhance the passivation effect. Tetrasodium ethylenediaminetetraacetic acid combines with copper ions through multiple coordination sites to form a stable complex, reducing the redeposition of copper ions on the surface of the copper foil during the passivation process and keeping the copper foil surface clean.

[0022] Traditional passivation requires 50-60℃ to perform passivation treatment, while the passivation agent of the present invention can complete the passivation treatment at room temperature, which is easy to operate and maintain. The passivation process does not require heating of the passivation agent, which effectively reduces production costs and energy loss. Moreover, the passivation agent in the present application does not contain chromic acid, which fully meets the current environmental protection requirements and is beneficial to environmental protection.

[0023] Optionally, the imidazole derivative includes at least one of 2-amino-benzoimidazole, hydroxybenzotriazole, 2-mercaptobenzoimidazole and 2-methylimidazole.

[0024] In summary, the present invention includes at least one of the following beneficial technical effects: 1. In the hydrocarbon cleaning process of copper foil in this application, the waste degreasing cleaning agent and waste passivating agent generated after the cleaning process are graded and distilled and recycled for reuse, and the degreasing cleaning agent, passivating agent and rolling oil are independently recovered and regenerated.

[0025] 2. In the hydrocarbon cleaning process for copper foil in this application, the passivation agent and degreasing cleaning are implemented together, the process is concentrated to reduce energy consumption, and efficient and environmentally friendly degreasing cleaning of thin copper foil is achieved. DETAILED DESCRIPTION

[0026] The present application designs a degreasing and cleaning process for copper foil, which at least comprises the following steps: S1. Send the produced copper foil to the cleaning work area, spray the degreasing cleaning agent on the surface of the copper foil for cleaning, and use a squeezing roller to squeeze the cleaned copper foil; S2, sending the copper foil squeezed in step S1 into the passivation work area, spraying the passivating agent on the surface of the copper foil for surface passivation treatment, and squeezing the passivated copper foil with a squeezing roller; S3, sending the copper foil squeezed out in step S2 into an oven for drying, and then performing hole detection, and the copper foil cleaning is completed.

[0027] The present application is further described in detail below in conjunction with specific embodiments.

[0028] Example 1 The degreasing and cleaning process of the copper foil in Example 1 comprises the following steps: S1. Send the produced copper foil to the cleaning work area, spray the degreasing cleaning agent on the surface of the copper foil for cleaning. The amount of degreasing cleaning agent is 90g / m 2 , the action time is 30 minutes, and then the cleaned copper foil is squeezed dry using a squeeze roller; S2, the copper foil squeezed in step S1 is sent to the passivation work area, and the passivation agent is sprayed on the surface of the copper foil for surface passivation treatment. The amount of degreasing cleaning agent is 40g / m 2 , the action time is 8min, and the passivated copper foil is squeezed dry using a squeeze roller; S3, sending the copper foil squeezed in step S2 into an oven for drying, and then performing hole detection, and the copper foil cleaning is completed; S4, collecting the liquid drawn from the squeeze roller in step S1 and the liquid drawn from the squeeze roller in step S2, mixing them to obtain a liquid mixture, distilling the liquid mixture, and separating to obtain hydrocarbon cleaning agent, passivating agent, and rolling oil.

[0029] In step S4, the distillation comprises the following steps: The liquid mixture is placed in a distillation device, the temperature is raised to 130°C, kept warm for 3 hours, and condensed and refluxed at the same time. The condensed liquid is an organic matter with a low boiling point, no pollution to the environment and less pollution, and can be discharged directly; then the liquid mixture is moved to a new distillation device, the temperature is raised to 150°C, kept warm for 2 hours and continuously stirred, and condensed and refluxed at the same time to obtain a separated degreasing cleaning agent; the liquid mixture from which the degreasing cleaning agent is separated is moved to a new distillation device, the temperature is raised to 230°C, kept warm for 2 hours and continuously stirred, and condensed and refluxed at the same time to obtain a separated passivating agent; the main component of the liquid mixture of the separated degreasing cleaning agent and the passivating agent is rolling oil, which is recovered and purified for reuse.

[0030] The degreasing cleaning agent used in Example 1 includes the following raw materials: 60g of hydrocarbon cleaning agent, 10g of methyl methacrylate, 15g of alcohol ether compound and 6g of fatty alcohol polyoxyethylene ether phosphate. The above raw materials are stirred and mixed at room temperature to obtain the degreasing cleaning agent.

[0031] Among them, the hydrocarbon cleaning agent uses n-nonane (C9H 20 ), with a boiling point of 150.7°C; the alcohol ether compound uses dipropylene glycol methyl ether.

[0032] The passivator used in Example 1 includes the following raw materials: 83g of imidazole derivative, 13g of alkyl alcohol, 0.3g of ethylenediaminetetraacetic acid tetrasodium salt, and deionized water to 100g. The imidazole derivative is 2-methylimidazole, and the alkyl alcohol is polyoxyethylene alkyl alcohol ether-10. The above raw materials are stirred and mixed at room temperature to obtain the passivator.

[0033] The copper foil cleaned in Example 1 was subjected to a neutral salt spray test. After 52 hours of neutral salt spray testing, the copper foil surface had no rust spots and good glossiness. The 1:1 nitric acid titration lasted up to 67 seconds, indicating that the passivation film had good corrosion resistance.

[0034] The component contents of the degreasing cleaning agent collected after the distillation treatment in Example 1 were measured, wherein the mass fraction of the hydrocarbon cleaning agent reached 92.4wt%. The component contents of the passivating agent collected after the distillation treatment in Example 1 were measured, wherein the mass fraction of the imidazole derivative reached 83.2wt%.

[0035] Example 2 The degreasing and cleaning process of the copper foil in Example 2 comprises the following steps: S1. Send the produced copper foil to the cleaning work area, spray the degreasing cleaning agent on the surface of the copper foil for cleaning. The amount of degreasing cleaning agent is 80g / m 2 , the action time is 40 minutes, and then the cleaned copper foil is squeezed dry using a squeeze roller; S2, the copper foil squeezed in step S1 is sent to the passivation work area, and the passivation agent is sprayed on the surface of the copper foil for surface passivation treatment. The amount of degreasing cleaning agent is 30g / m 2 , the action time is 10min, and the passivated copper foil is squeezed dry using a squeeze roller; S3, sending the copper foil squeezed in step S2 into an oven for drying, and then performing hole detection, and the copper foil cleaning is completed; S4, collecting the liquid drawn from the squeeze roller in step S1 and the liquid drawn from the squeeze roller in step S2, mixing them to obtain a liquid mixture, distilling the liquid mixture, and separating to obtain hydrocarbon cleaning agent, passivating agent, and rolling oil.

[0036] In step S4, the distillation comprises the following steps: The liquid mixture is placed in a distillation device, the temperature is raised to 130°C, kept warm for 3 hours, and condensed and refluxed at the same time. The condensed liquid is an organic matter with a low boiling point, no pollution to the environment and less pollution, and can be discharged directly; then the liquid mixture is moved to a new distillation device, the temperature is raised to 150°C, kept warm for 2 hours and continuously stirred, and condensed and refluxed at the same time to obtain a separated degreasing cleaning agent; the liquid mixture from which the degreasing cleaning agent is separated is moved to a new distillation device, the temperature is raised to 230°C, kept warm for 2 hours and continuously stirred, and condensed and refluxed at the same time to obtain a separated passivating agent; the main component of the liquid mixture of the separated degreasing cleaning agent and the passivating agent is rolling oil, which is recovered and purified for reuse.

[0037] The degreasing cleaning agent used in Example 2 includes the following raw materials: 50g hydrocarbon cleaning agent, 15g methyl methacrylate, 10g alcohol ether compound and 8g fatty alcohol polyoxyethylene ether phosphate. The imidazole derivative is hydroxybenzotriazole. The degreasing cleaning agent is obtained by stirring and mixing the above raw materials at room temperature.

[0038] Among them, the hydrocarbon cleaning agent uses n-decane (C 10 H 22 ), with a boiling point of 174°C; the alcohol ether compound uses propylene glycol butyl ether.

[0039] The passivating agent used in Example 2 includes the following raw materials: 80 g of imidazole derivatives, 15 g of alkyl alcohols, 0.1 g of ethylenediaminetetraacetic acid tetrasodium salt, and deionized water to make up to 100 g. The above raw materials are stirred and mixed at room temperature to obtain the passivating agent.

[0040] The copper foil cleaned in Example 2 was subjected to a neutral salt spray test. After 44 hours of neutral salt spray testing, the copper foil surface had no rust spots and good glossiness. The 1:1 nitric acid titration lasted up to 74 seconds, indicating that the copper foil passivation film had good corrosion resistance.

[0041] The component contents of the degreasing cleaning agent collected after the distillation treatment in Example 2 were measured, wherein the mass fraction of the hydrocarbon cleaning agent reached 94.1wt%. The component contents of the passivating agent collected after the distillation treatment in Example 1 were measured, wherein the mass fraction of the imidazole derivative reached 80.6wt%.

[0042] Example 3 The degreasing and cleaning process of the copper foil in Example 3 comprises the following steps: S1. Send the produced copper foil to the cleaning work area, spray the degreasing cleaning agent on the surface of the copper foil for cleaning. The amount of degreasing cleaning agent is 140g / m 2 , the action time is 20 minutes, and then the cleaned copper foil is squeezed dry using a squeeze roller; S2, the copper foil squeezed in step S1 is sent to the passivation work area, and the passivation agent is sprayed on the surface of the copper foil for surface passivation treatment. The amount of degreasing cleaning agent is 60g / m 2 , the action time is 6 minutes, and the passivated copper foil is squeezed dry using a squeeze roller; S3, sending the copper foil squeezed in step S2 into an oven for drying, and then performing hole detection, and the copper foil cleaning is completed; S4, collecting the liquid drawn from the squeeze roller in step S1 and the liquid drawn from the squeeze roller in step S2, mixing them to obtain a liquid mixture, distilling the liquid mixture, and separating to obtain hydrocarbon cleaning agent, passivating agent, and rolling oil.

[0043] In step S4, the distillation comprises the following steps: The liquid mixture is placed in a distillation device, the temperature is raised to 130°C, kept warm for 3 hours, and condensed and refluxed at the same time. The condensed liquid is an organic matter with a low boiling point, no pollution to the environment and less pollution, and can be discharged directly; then the liquid mixture is moved to a new distillation device, the temperature is raised to 170°C, kept warm for 2 hours and continuously stirred, and condensed and refluxed at the same time to obtain a separated degreasing cleaning agent; the liquid mixture from which the degreasing cleaning agent is separated is moved to a new distillation device, the temperature is raised to 230°C, kept warm for 2 hours and continuously stirred, and condensed and refluxed at the same time to obtain a separated passivating agent; the main component of the liquid mixture of the separated degreasing cleaning agent and the passivating agent is rolling oil, which is recovered and purified for reuse.

[0044] The degreasing cleaning agent used in Example 3 includes the following raw materials: 80g of hydrocarbon cleaning agent, 15g of methyl methacrylate, 10g of alcohol ether compound and 5g of fatty alcohol polyoxyethylene ether phosphate. The above raw materials are stirred and mixed at room temperature to obtain the degreasing cleaning agent.

[0045] Among them, the hydrocarbon cleaning agent uses n-undecane (C 11 H 24 ), with a boiling point of 195.8°C; the alcohol ether compound uses propylene glycol n-propyl ether.

[0046] The passivator used in Example 3 includes the following raw materials: 85g of imidazole derivatives, 10g of alkyl alcohols, 0.5g of ethylenediaminetetraacetic acid tetrasodium salt, and deionized water to 100g. The imidazole derivative is a mixture of 2-amino-benzoimidazole and 2-methylimidazole in a mass ratio of 1:1. The above raw materials are stirred and mixed at room temperature to obtain the passivator.

[0047] The copper foil cleaned in Example 3 was subjected to a neutral salt spray test. After 48 hours of neutral salt spray testing, the copper foil surface had no rust spots and good glossiness. The 1:1 nitric acid titration lasted up to 69 seconds, indicating that the passivation film had good corrosion resistance.

[0048] The component contents of the degreasing cleaning agent collected after the distillation treatment in Example 3 were measured, wherein the mass fraction of the hydrocarbon cleaning agent reached 88.5wt%. The component contents of the passivating agent collected after the distillation treatment in Example 1 were measured, wherein the mass fraction of the imidazole derivative reached 81.6wt%.

[0049] In summary, the degreasing and cleaning process of the copper foil in the present application performs graded distillation and recycling of the waste degreasing cleaning agent and waste passivating agent generated after the cleaning process, and independently recycles the degreasing cleaning agent and passivating agent.

[0050] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A degreasing and cleaning process for copper foil, characterized in that: At least the following steps are included: S1. Send the produced copper foil to the cleaning work area, spray the degreasing cleaning agent on the surface of the copper foil for cleaning, and use a squeezing roller to squeeze the cleaned copper foil; S2, sending the copper foil squeezed in step S1 into the passivation work area, spraying the passivating agent on the surface of the copper foil for surface passivation treatment, and squeezing the passivated copper foil with a squeezing roller; S3, sending the copper foil squeezed out in step S2 into an oven for drying, and then performing hole detection, and the copper foil cleaning is completed.

2. The degreasing and cleaning process of copper foil according to claim 1, characterized in that: The method further includes step S4, which includes the following steps: collecting the liquid squeezed by the squeezing roller in step S1 and the liquid squeezed by the squeezing roller in step S2, mixing them to obtain a liquid mixture, distilling the liquid mixture, and separating to obtain hydrocarbon cleaning agent, passivating agent, and rolling oil.

3. The degreasing and cleaning process of copper foil according to claim 2, characterized in that: In step S4, hydrocarbon cleaning agent, passivating agent and rolling oil are separated by utilizing different boiling points. In step S4, distillation includes the following steps: Add the liquid mixture and place it in a distillation device, raise the temperature to 150-210°C, keep it warm for 2-4 hours and continue stirring, and condense and reflux at the same time to obtain a separated degreasing cleaning agent; move the liquid mixture from which the degreasing cleaning agent is separated into a new distillation device, raise the temperature to 220-275°C, keep it warm for 2-4 hours and continue stirring, and condense and reflux at the same time to obtain a separated passivating agent; the main component of the liquid mixture from which the degreasing cleaning agent and the passivating agent are separated is rolling oil, which is recovered and purified for reuse.

4. The degreasing and cleaning process of copper foil according to claim 1, characterized in that: The degreasing cleaning agent comprises the following raw materials in parts by weight: 50-80 parts of hydrocarbon cleaning agent, 5-15 parts of methyl methacrylate, 10-20 parts of alcohol ether compounds, and 5-8 parts of fatty alcohol polyoxyethylene ether phosphate.

5. The degreasing and cleaning process for copper foil according to claim 1, characterized in that: The hydrocarbon cleaning agent is a normal alkane solvent or an isoalkane solvent with a distillation range of 150-210°C.

6. The degreasing and cleaning process of copper foil according to claim 5, characterized in that: The normal alkane solvent is selected from alkanes with carbon atoms ranging from 6 to 13, or the isoalkane solvent is selected from alkane isomers with carbon atoms ranging from 6 to 13.

7. The degreasing and cleaning process of copper foil according to claim 4, characterized in that: The alcohol ether compound includes one or more of propylene glycol butyl ether, dipropylene glycol butyl ether, dipropylene glycol methyl ether, propylene glycol n-propyl ether, and dipropylene glycol n-propyl ether.

8. The degreasing and cleaning process for copper foil according to claim 1, characterized in that: The passivator comprises the following components in parts by weight: 80-85 parts of imidazole derivatives, 10-15 parts of alkyl alcohols, 0.1-0.5 parts of tetrasodium ethylenediaminetetraacetic acid, and deionized water as a supplement.

9. The degreasing and cleaning process of copper foil according to claim 8, characterized in that: The imidazole derivative includes at least one of 2-amino-benzoimidazole, hydroxybenzotriazole, 2-mercaptobenzoimidazole and 2-methylimidazole.