Surface treatment method of high-purity silver evaporation material

Abstract

The invention belongs to the technical field of material surface treatment, and particularly discloses a surface treatment method for a high-purity silver evaporation material. The method comprises the following steps: carrying out ultrasonic cleaning on a high-purity silver evaporation material by using an ethanol deionized water solution; then, a roller polishing machine is used for polishing the pre-cleaned high-purity silver evaporation material; then, the polished high-purity silver evaporation material is soaked with turpentine; and then, acetone, ethyl alcohol and deionized water are sequentially used for conducting ultrasonic cleaning on the high-purity silver evaporation material soaked in the turpentine oil, and the high-purity silver evaporation material with the smooth and clean surface is obtained. According to the method, the green, nontoxic and recyclable solvent is adopted, polishing treatment is combined, residual oil stains on the surface of the evaporation material can be efficiently removed, surface defects of the evaporation material can be eliminated, the surface is smoother, the surface quality of the evaporation material is improved, and therefore the use stability and coating performance of the evaporation material are improved; the cleaning agent has the characteristics of low loss, good decontamination effect, high surface quality and recyclable solvent.

Description

Technical Field

[0001] The invention relates to the technical field of material surface treatment, and in particular to a surface treatment method for a high-purity silver evaporation material with low loss, good decontamination effect, high surface quality and solvent recycling. Background Art

[0002] As a renewable energy source, solar energy has developed rapidly around the world in recent years. The development of solar cells is inseparable from high-performance conductive materials, which can ensure the efficient transmission of current, thereby reducing resistance loss and improving the conversion efficiency and stability of the battery. Among many conductive materials, high-purity silver evaporation materials have extremely high electrical conductivity and can form good electrodes on solar cells to effectively collect and transmit photogenerated carriers. The preparation of battery electrodes usually uses vacuum evaporation coating technology. With the continuous advancement of solar energy technology, the battery has higher and higher requirements for the quality and performance of electrodes prepared by high-purity silver evaporation materials.

[0003] Since surface defects of silver evaporation materials can lead to uneven coating performance, which in turn affects battery efficiency, and silver evaporation materials will inevitably have problems such as residual impurities and dirt on the surface during the preparation process, in order to ensure the quality of electrodes in the solar cell preparation process, it is necessary to remove surface defects and dirt of the silver evaporation material, thereby improving the quality of the silver evaporation material.

[0004] At present, the surface treatment of traditional evaporation materials is to first use pickling to remove the surface oxide layer and impurities, and then wash to remove the acid and surface dirt; but because the evaporation material has not been ground or polished to remove impurities, a large amount of acid is required for pickling, and too much acid will increase the loss of the evaporation material. In addition, the use of acid is not conducive to the improvement of the production environment and increases the difficulty of subsequent acid treatment.

[0005] In the prior art, in order to solve the problems existing in direct pickling, the silver evaporation material is cleaned after being subjected to centrifugal grinding (such as patent CN108987273A), and the oxide layer on the surface of the silver evaporation material is removed by centrifugal grinding and the surface polishing effect is achieved; although the loss of the silver evaporation material can be reduced compared with pickling, the loss of the silver evaporation material is still large, and the contaminants will be more firmly attached during the grinding process, making it difficult to effectively remove them during subsequent cleaning. To this end, there is also a technical solution that uses a mixture containing hydrogen peroxide-ammonia water to first clean the silver evaporation material, then uses IPA liquid to clean the silver evaporation material after the previous step, and finally uses pure water to clean it (such as patent CN111334809A); ​​and a technical solution that first uses an organic solvent to ultrasonically clean the metal evaporation material, then uses an inorganic mixed acid to pickle the metal evaporation material after ultrasonic cleaning, and finally ultrasonically cleans the metal evaporation material after pickling again and then dries it (such as patent CN111394697A). Although the above two technical solutions can reduce the loss of evaporation materials, due to the excessive amount of organic solvents used and the use of acids and highly volatile substances, it is not only not conducive to environmental protection, but also has a high process cost, and cannot solve the problem of surface defects of the evaporation material.

[0006] Therefore, it is particularly important to seek a surface treatment method for high-purity silver evaporation materials with low loss, good decontamination effect, high surface quality and recyclable solvent. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a surface treatment method for high-purity silver evaporation material with low loss, good decontamination effect, high surface quality and recyclable solvent, so as to solve the shortcomings of the existing treatment methods such as difficulty in effectively removing surface defects, great environmental pressure, high cost and difficulty in recycling solvents.

[0008] The surface treatment method of the high-purity silver evaporation material of the present invention is achieved by comprising the steps of pre-cleaning, surface polishing, immersion treatment, and ultrasonic cleaning, and the specific contents are as follows: A. Pre-cleaning: Use ethanol deionized water solution to ultrasonically clean the high-purity silver evaporation material to be treated; B. Surface polishing: Use a drum polisher to polish the pre-cleaned high-purity silver evaporation material; C. Soaking treatment: Soak the polished high-purity silver evaporation material in turpentine; D. Ultrasonic cleaning: Use acetone, ethanol and deionized water in turn to ultrasonically clean the high-purity silver evaporation material soaked in turpentine to obtain a high-purity silver evaporation material with a smooth and clean surface.

[0009] Furthermore, the purity of silver in the high-purity silver evaporation material to be processed in step A is ≥99.99%, and the high-purity silver evaporation material is a cylinder.

[0010] Furthermore, the high-purity silver evaporated material to be treated in step A is ultrasonically cleaned at room temperature for 8 to 12 minutes, and the concentration of ethanol in the ethanol deionized water solution is 60 to 80%.

[0011] Furthermore, the high-purity silver evaporation material is a cylinder of Φ2~5mm×2~5mm.

[0012] Furthermore, the concentration of the ethanol solution in step A and step D is ≥99%, and the concentration of the acetone solution in step D is ≥99%.

[0013] Furthermore, in step B, the drum polishing machine uses a steel ball with a diameter smaller than the diameter of the high-purity silver evaporation material as a polishing abrasive, wherein the mass ratio of the steel ball to the high-purity silver evaporation material is 5-10:1, and the drum polishing machine is set to rotate in the opposite direction at 1000-2500 r / min and polish for 10-20 minutes.

[0014] Furthermore, the volume ratio of the steel balls and the high-purity silver evaporation material in the drum polishing machine to the volume ratio of the drum is ≤ 2 / 3.

[0015] Furthermore, the high-purity silver evaporation material in step C is soaked in turpentine at room temperature for 3 to 5 minutes.

[0016] Furthermore, the high-purity silver evaporated material in step D is ultrasonically cleaned in acetone, ethanol and deionized water at room temperature for 4-6 minutes, 8-12 minutes and 13-17 minutes respectively.

[0017] Furthermore, the present invention also includes a drying step, wherein the high-purity silver evaporation material after ultrasonic cleaning with deionized water is vacuum dried at a temperature of 60 to 80° C. for 60 to 90 minutes, and the vacuum degree of the vacuum drying is ≤10 -2 Pa.

[0018] The beneficial effects of the present invention are: 1. The surface treatment method of the high-purity silver evaporation material of the present invention uses 4N silver evaporation material as raw material, and adopts a low-cost, green and environmentally friendly aqueous solvent combined with a physical polishing process, which can not only efficiently remove residual oil stains on the surface of the evaporation material, but also eliminate the defects on the surface of the evaporation material, so that the surface of the evaporation material is smoother and flatter, effectively improving the surface quality of the evaporation material, and can improve the stability of the evaporation material during use and the coating performance. In addition, because a non-toxic and harmless water-soluble solvent is used, the price is low and can be recycled, and the process flow can be simplified and the difficulty of handling the later cleaning solution can be reduced.

[0019] 2. The surface treatment method of the high-purity silver evaporation material of the present invention first uses a green, non-toxic, and highly soluble ethanol deionized water solution to pretreat the impurities (such as Mg, Al, Si, Cu, etc.) remaining on the surface of the silver evaporation material after machining and convert the oil stains into water-soluble compounds to prevent the impurities, oil stains, etc. from being more firmly attached or entering the interior of the evaporation material under physical action during the subsequent polishing process, thereby laying a foundation for subsequently obtaining an evaporation material with a high-quality surface.

[0020] 3. The surface treatment method of the high-purity silver evaporation material of the present invention uses a drum polisher to polish the surface of the evaporation material, and uses steel balls slightly smaller than the evaporation material to more efficiently remove surface defects of the raw material, and by strictly controlling the mass ratio of steel balls to evaporation material to be 5-10:1, it can avoid the problem that the polishing effect is poor when there are fewer polishing steel balls, resulting in difficulty in removing surface defects, and can also avoid the problem that the polishing efficiency is reduced when there are more steel balls, thereby extending the polishing time and increasing the energy consumption of the equipment. Therefore, not only the polishing efficiency is optimal, but also the evaporation material loss is less than 0.5%, and the evaporation material surface is smooth, which can improve the evaporation performance.

[0021] 4. The surface treatment method of the high-purity silver evaporation material of the present invention makes use of the principle that the main components of turpentine oil are terpene compounds and are similar to the oil stains on the surface of the evaporation material. The strong solubility of turpentine oil can eliminate the oil stains on the surface of the polished silver evaporation material, thereby improving the surface quality of the evaporation material, and ultimately improving the stability of the evaporation material during evaporation and the coating performance. Compared with the existing evaporation material cleaning method, it can also reduce the loss of silver.

[0022] 5. The surface treatment method of the high-purity silver evaporation material of the present invention is followed by ultrasonic cleaning with acetone, ethanol and deionized water in sequence, wherein acetone can not only remove the turpentine remaining on the evaporation material, but also has a carbonyl group (C=O), so that it can interact with the fatty acid glyceride in the oil, thereby playing a dissolving role and removing the residual oil on the surface; finally, the organic solvent remaining on the surface is removed by ethanol and deionized water respectively, so that the cleanliness of the evaporation material can be greatly improved; and the aforementioned solvents are all low-toxic or non-toxic substances, not only inexpensive, but also no violent chemical reaction occurs in the process link, and no harmful gas is generated, thereby simplifying the corresponding operation process and reducing the difficulty of solvent treatment in the later stage, and is particularly suitable for promotion and application in the surface treatment of high-purity metal evaporation materials.

[0023] In summary, the present invention has the characteristics of less loss, good decontamination effect, high surface quality and recyclable solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The photograph and scanning electron microscope image of the high-purity silver evaporation material before surface treatment in the embodiment of the present invention; Figure 2The photograph and scanning electron microscope image of the high-purity silver evaporation material after surface treatment in Example 1 of the present invention; Figure 3 The photograph and scanning electron microscope image of the high-purity silver evaporation material after surface treatment in Example 2 of the present invention; Figure 4 This is a scanning electron microscope image of the high-purity silver evaporated material after surface treatment in Comparative Example 1 of the present invention; Figure 5 This is a scanning electron microscope image of the high-purity silver evaporated material after surface treatment in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The surface treatment method of the high-purity silver evaporation material of the present invention comprises the steps of pre-cleaning, surface polishing, immersion treatment and ultrasonic cleaning, and the specific contents are as follows: A. Pre-cleaning: Use ethanol deionized water solution to ultrasonically clean the high-purity silver evaporation material to be treated; B. Surface polishing: Use a drum polisher to polish the pre-cleaned high-purity silver evaporation material; C. Soaking treatment: Soak the polished high-purity silver evaporation material in turpentine; D. Ultrasonic cleaning: Use acetone, ethanol and deionized water in turn to ultrasonically clean the high-purity silver evaporation material soaked in turpentine to obtain a high-purity silver evaporation material with a smooth and clean surface.

[0027] The purity of silver in the high-purity silver evaporation material to be processed in step A is ≥99.99%, and the high-purity silver evaporation material is a cylinder.

[0028] The high-purity silver evaporated material to be treated in step A is ultrasonically cleaned at room temperature for 8-12 minutes, and the concentration of ethanol in the ethanol deionized water solution is 60-80%.

[0029] The high-purity silver evaporation material is a cylinder of Φ2~5mm×2~5mm.

[0030] The concentration of the ethanol solution in step A and step D is ≥99%, and the concentration of the acetone solution in step D is ≥99%.

[0031] In step B, the drum polishing machine uses steel balls with a diameter smaller than that of the high-purity silver evaporation material as polishing abrasives, wherein the mass ratio of the steel balls to the high-purity silver evaporation material is 5-10:1, and the drum polishing machine is set to rotate in the opposite direction at 1000-2500 r / min and polish for 10-20 minutes.

[0032] The volume ratio of the steel balls and the high-purity silver evaporation material in the drum polishing machine to the volume ratio of the drum is ≤2 / 3.

[0033] The high-purity silver evaporated material in step C is soaked in turpentine at room temperature for 3 to 5 minutes.

[0034] The high-purity silver evaporated material in step D is ultrasonically cleaned in acetone, ethanol and deionized water at room temperature for 4-6 minutes, 8-12 minutes and 13-17 minutes respectively.

[0035] The present invention also includes a drying step, wherein the high-purity silver evaporated material after ultrasonic cleaning with deionized water is vacuum dried at a temperature of 60 to 80°C for 60 to 90 minutes, and the vacuum degree of the vacuum drying is ≤10 -2 Pa.

[0036] Example 1 S100: a certain amount of 4N silver evaporation material to be treated (cylinder with a size of Φ3mm×3mm) is placed in an ethanol deionized water solution with an ethanol concentration of 80% (enough to submerge the silver evaporation material), and ultrasonically cleaned at room temperature for 10 minutes.

[0037] S200: Put the silver evaporation material treated in step S100 into a cylindrical polishing machine, wherein the mass ratio of polishing steel balls (Φ2mm) to the silver evaporation material is 5:1, and the volume ratio of the steel balls to the silver evaporation material to the volume ratio of the drum is 1 / 2, and polish for 10 minutes at a reverse rotation of 2500r / min.

[0038] S300: Soak the silver evaporated material treated in step S200 in turpentine for 3 minutes.

[0039] S400: The silver evaporated material soaked in step S300 is ultrasonically cleaned in acetone, ethanol, and deionized water for 5 minutes, 10 minutes, and 15 minutes respectively (subject to submerging the silver evaporated material).

[0040] S500: The silver evaporated material after ultrasonic cleaning with deionized water in step S400 is heated to 80°C and the vacuum degree is ≤10 -2 The mixture was dried under vacuum at 370 °C for 60 min to obtain a surface-treated high-purity silver evaporation material.

[0041] Example 2 S100: Place a certain amount of 4N silver evaporation material to be treated (cylinder with a size of Φ3mm×3mm) into a deionized ethanol solution with an ethanol concentration of 60% (enough to submerge the silver evaporation material), and ultrasonically clean it at room temperature for 12 minutes.

[0042] S200: Put the silver evaporation material treated in step S100 into a cylindrical polishing machine, wherein the mass ratio of polishing steel balls (Φ2mm) to the silver evaporation material is 8:1, and the volume ratio of the steel balls to the silver evaporation material is 2 / 3 of the volume ratio of the drum, and polish for 15 minutes at a reverse rotation of 1500r / min.

[0043] S300: Soak the silver evaporated material treated in step S200 in turpentine for 5 minutes.

[0044] S400: The silver evaporated material soaked in step S300 is ultrasonically cleaned in acetone, ethanol, and deionized water for 6 minutes, 8 minutes, and 17 minutes respectively (subject to submerging the silver evaporated material).

[0045] S500: The silver evaporated material after ultrasonic cleaning with deionized water in step S400 is heated to 60°C and vacuum degree ≤10 -2 The mixture was dried under vacuum at 370 °C for 90 min to obtain a surface-treated high-purity silver evaporation material.

[0046] Comparative Example 1 S100: a certain amount of 4N silver evaporation material to be treated (cylinder with a size of Φ3mm×3mm) is placed in an ethanol deionized water solution with an ethanol concentration of 80% (enough to submerge the silver evaporation material), and ultrasonically cleaned at room temperature for 10 minutes.

[0047] S200: Put the silver evaporation material treated in step S100 into a cylindrical polishing machine, wherein the mass ratio of polishing steel balls (Φ2mm) to the silver evaporation material is 8:1, and the volume ratio of the steel balls to the silver evaporation material to the volume ratio of the drum is 1 / 2, and polish for 12 minutes at a reverse rotation of 2000r / min.

[0048] S300: ultrasonically clean the silver evaporated material soaked in step S300 in deionized water for 15 minutes (submerging the silver evaporated material).

[0049] S400: The silver evaporated material after ultrasonic cleaning with deionized water in step S400 is heated to 80°C and the vacuum degree is ≤10 -2 The mixture was dried under vacuum at 370 °C for 60 min to obtain a surface-treated high-purity silver evaporation material.

[0050] Comparative Example 2 S100: a certain amount of 4N silver evaporation material to be treated (cylinder with a size of Φ3mm×3mm) is placed in an ethanol deionized water solution with an ethanol concentration of 80% (enough to submerge the silver evaporation material), and ultrasonically cleaned at room temperature for 10 minutes.

[0051] S200: Put the silver evaporation material treated in step S100 into a cylindrical polishing machine, wherein the mass ratio of polishing steel balls (Φ3mm) to the silver evaporation material is 10:1, and the volume ratio of the steel balls to the silver evaporation material is 1 / 2 of the volume of the drum, and polish for 20 minutes at a reverse rotation of 1000r / min.

[0052] S300: The silver evaporated material soaked in step S300 is ultrasonically cleaned in ethanol and deionized water for 10 minutes and 15 minutes respectively (subject to submerging the silver evaporated material).

[0053] S400: vacuum drying the silver evaporated material after ultrasonic cleaning with deionized water in step S400 at 80° C. and a vacuum degree of ≤10-2Pa for 60 minutes to obtain a surface-treated high-purity silver evaporated material.

[0054] Depend on Figure 1 and Figure 2 and Figure 3 By comparison, it can be seen that the surface of the silver evaporation material treated by the surface treatment method of the present invention is clean, free of defects, impurities and oil stains.

[0055] Depend on Figure 4 It can be seen that the surface oil and dirt on the silver evaporated material that is only cleaned with deionized water ultrasonically after polishing is difficult to be cleaned, and the surface oil and dirt remain the most.

[0056] Depend on Figure 5 It can be seen that the surface defects of the silver evaporation material are difficult to be effectively removed due to the use of polishing steel balls that are as large as the silver evaporation material. The surface defects are more obvious. The silver evaporation material after polishing is ultrasonically cleaned with ethanol and deionized water in turn. Figure 4 There is less oil and other residue on the surface, but compared with Figure 2 and Figure 3 There is still obvious residue, indicating that the oil removal effect is poor.

[0057] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A surface treatment method for high-purity silver evaporation material, characterized in that: It includes pre-cleaning, surface polishing, immersion treatment, and ultrasonic cleaning steps. The specific contents are as follows: A. Pre-cleaning: Use ethanol deionized water solution to ultrasonically clean the high-purity silver evaporation material to be treated; B. Surface polishing: Use a drum polisher to polish the pre-cleaned high-purity silver evaporation material; C. Soaking treatment: Soak the polished high-purity silver evaporation material in turpentine; D. Ultrasonic cleaning: Use acetone, ethanol and deionized water in turn to ultrasonically clean the high-purity silver evaporation material soaked in turpentine to obtain a high-purity silver evaporation material with a smooth and clean surface.

2. The surface treatment method of the high-purity silver evaporation material according to claim 1, characterized in that: The purity of silver in the high-purity silver evaporation material to be processed in step A is ≥99.99%, and the high-purity silver evaporation material is a cylinder.

3. The surface treatment method of the high-purity silver evaporation material according to claim 2, characterized in that: The high-purity silver evaporated material to be treated in step A is ultrasonically cleaned at room temperature for 8-12 minutes, and the concentration of ethanol in the ethanol deionized water solution is 60-80%.

4. The surface treatment method of the high-purity silver evaporation material according to claim 2, characterized in that: The high-purity silver evaporation material is a cylinder of Φ2~5mm×2~5mm.

5. The surface treatment method of the high-purity silver evaporation material according to claim 1, characterized in that: The concentration of the ethanol solution in step A and step D is ≥99%, and the concentration of the acetone solution in step D is ≥99%.

6. The surface treatment method of high-purity silver evaporation material according to any one of claims 2 to 5, characterized in that: In step B, the drum polishing machine uses steel balls with a diameter smaller than that of the high-purity silver evaporation material as polishing abrasives, wherein the mass ratio of the steel balls to the high-purity silver evaporation material is 5-10:1, and the drum polishing machine is set to rotate in the opposite direction at 1000-2500 r / min and polish for 10-20 minutes.

7. The surface treatment method of the high-purity silver evaporation material according to claim 6, characterized in that: The volume ratio of the steel balls and the high-purity silver evaporation material in the drum polishing machine to the volume ratio of the drum is ≤2 / 3.

8. The surface treatment method of high-purity silver evaporation material according to claim 6, characterized in that: The high-purity silver evaporated material in step C is soaked in turpentine at room temperature for 3 to 5 minutes.

9. The surface treatment method of the high-purity silver evaporation material according to claim 6, characterized in that: The high-purity silver evaporated material in step D is ultrasonically cleaned in acetone, ethanol and deionized water at room temperature for 4-6 minutes, 8-12 minutes and 13-17 minutes respectively.

10. The surface treatment method of high-purity silver evaporation material according to claim 6, characterized in that: The step of drying is to vacuum dry the high-purity silver evaporated material after ultrasonic cleaning with deionized water at a temperature of 60 to 80° C. for 60 to 90 minutes, and the vacuum degree of the vacuum drying is ≤10 -2 Pa.

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