A stripping solution capable of improving stripping efficiency and its preparation method

Abstract

The present invention discloses a stripping solution capable of improving the stripping efficiency and a preparation method thereof. The stripping solution is prepared through two main steps: First, a composite alkali, a penetrant, ethylene glycol dimethyl ether and water are mixed and heated with stirring to form a mixed solution; Second, water and a corrosion inhibitor are added to the mixed solution, and stirring is carried out at room temperature to form the final stripping solution. The composite alkali is composed of an inorganic alkali and an organic alkali. The inorganic alkali includes sodium hydroxide, potassium hydroxide and sodium carbonate, and the organic alkali includes ethanolamine and propylenediamine. Compared with the prior art, the stripping solution of the present invention can penetrate and strip the film layer on the metal surface more quickly, reduce the residue of the dry film or other materials, ensure the cleanliness of the substrate surface, thereby improving the stripping efficiency, and has significant advantages in industrial applications.

Description

Technical Field

[0001] The present invention relates to the technical field of film stripping technology, and particularly to a film stripping solution capable of improving film stripping efficiency and a preparation method thereof. Background Art

[0002] In the fields of electronic manufacturing and metal surface treatment, the film stripping process is a key step for removing coatings or film layers on the surface of metals or circuit boards. Traditional film stripping solutions usually face the problem of diffusion rate limitation, which directly affects the efficiency and effect of the film stripping process.

[0003] The main components of the film stripping agent, such as surfactants, solvents, and other active components, need to diffuse into the interior of the dry film to achieve effective stripping. The rate of this step is a key factor in the film stripping speed. However, the poor hydrophilicity of the dry film will limit the penetration speed of the film stripping agent, thereby slowing down the entire film stripping process.

[0004] Many dry film materials are designed with low hydrophilicity to provide specific protective properties, but this also limits the diffusion of water and active ingredients in the film stripping agent. Due to the limitation of the diffusion rate, the film stripping process may take a long time, which reduces production efficiency and increases costs. During the film stripping process, if the film stripping agent cannot fully penetrate the dry film, it may cause incomplete stripping of the film layer, leaving residues and affecting the quality of the final product.

[0005] Chinese invention authorization patent CN108008606B discloses a film stripping solution for photosensitive dry film, a production method and an application thereof. The film stripping solution includes inorganic base, organic base, solvent, additive, and water; wherein the base equivalent is 0.4 - 1.25 mol / L, and the content of the inorganic base is 0.5 - 2 g / L, and the volume of the organic base added accounts for 2 - 5% of the film stripping solution. This invention uses the organic base as the main film stripping component to react with the dry film polymer, and at the same time incorporates a certain amount of inorganic base component to supplement the concentration of OH- during the film stripping process; selecting a high-boiling alcohol ether solvent can better play the role of penetrating and swelling the dry film. The additive aromatic azole chelate is a film-forming substance with a specific affinity for metals, thus ensuring that the surface of the conductive film layer will not be oxidized and eroded during the film stripping process. Its configuration is simple and safe, and it has a strong ability to strip dry film under normal spray stamping operation conditions, with high production efficiency and yield. However, the film stripping time of the film stripping solution of this invention is still relatively long, and there are still certain residues. Summary of the Invention

[0006] Aiming at the limitations of the prior art, the present invention provides a film stripping solution and a preparation method thereof, aiming to improve the film stripping efficiency, reduce the film stripping time and residues, and improve the quality of the final product.

[0007] In order to achieve the above-mentioned invention purpose, the present invention adopts the following technical solutions:

[0008] A stripping solution that can improve the stripping efficiency is composed of the following components: compound alkali, penetrant, organic solvent, corrosion inhibitor, and water.

[0009] The stripping solution that can improve the stripping efficiency is composed of the following components by weight: 25 - 35 parts of compound alkali, 10 - 20 parts of penetrant, 5 - 10 parts of organic solvent, 1 - 4 parts of corrosion inhibitor, and 40 - 50 parts of water.

[0010] The compound alkali is composed of inorganic alkali and organic alkali in a mass ratio of 10 - 15:1 - 3. The inorganic alkali is composed of sodium hydroxide, potassium hydroxide, and sodium carbonate in a mass ratio of 8 - 10:2 - 4:1; the organic alkali is composed of ethanolamine and propylenediamine in a mass ratio of 0.7 - 0.9:1 - 1.5.

[0011] The organic solvent is one or more of ethylene glycol dimethyl ether, cyclohexanone, and ethyl acetate.

[0012] The corrosion inhibitor is composed of octadecyl phosphate, oleic acid, sodium molybdate, sodium nitrate, benzotriazole, and zinc sulfate in a mass ratio of 9 - 11:9 - 11:2 - 4:40 - 60:6 - 8:18 - 22.

[0013] The preparation method of the penetrant is as follows, by weight:

[0014] S1. Add 400 - 600 parts of water to the reaction kettle and preheat it to 40 - 60 °C. Gradually add 10 - 15 parts of 10 - hydroxy - 18 - [2 - [2 - (sulfonyloxy)ethoxy], 13 - 16 parts of estriol trisulfate trisodium salt, and 20 - 30 parts of sulfated castor oil to the water. After each raw material is added, stir until it is completely dissolved, and continue to stir at 40 - 60 °C for 20 - 40 minutes to obtain a uniform solution;

[0015] S2. Under stirring, add 4 - 6 parts of emulsifier and 7 - 9 parts of bis(1 - methyl - 2 - hydroxyethyl) ether, and continue to stir for 5 - 15 minutes; add 1 - 3 parts of compound defoamer; continue to stir until the defoamer is completely dispersed, and use a microporous filter to filter to remove possible solid particles or insolubles to obtain the penetrant.

[0016] The emulsifier is sucrose fatty acid ester.

[0017] The compound defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropyl alcohol in a mass ratio of 0.8 - 1.2:1 - 3:0.8 - 1.2.

[0018] The pore size of the microporous filter is 0.4 - 0.5 μm.

[0019] The preparation method of a stripping solution that can improve the stripping efficiency is as follows:

[0020] Step 1: Weigh each raw material by weight parts. Mix the compound alkali, penetrant, organic solvent and water, then add them into a stirring kettle. Stir while heating, control the heating temperature at 50 - 60 °C, the stirring rate at 100 - 200 revolutions per minute, and the stirring time for 20 - 40 minutes. Then cool to room temperature to obtain a mixed solution.

[0021] Step 2: Add water and corrosion inhibitor into the mixed solution prepared in Step 1, then stir at room temperature, with the stirring rate of 400 - 600 revolutions per minute and the time of 100 - 150 minutes to obtain a film stripping solution.

[0022] The functions of various substances mentioned in the present invention are as follows:

[0023] The compound alkali is composed of inorganic alkali and organic alkali, which is the main active ingredient in the film stripping solution and is responsible for removing the film layer on the metal surface.

[0024] The inorganic alkali is composed of sodium hydroxide, potassium hydroxide and sodium carbonate. These substances have strong alkalinity and can chemically react with the film layer on the metal surface to promote the dissolution and peeling of the film layer.

[0025] The organic alkali is composed of ethanolamine and propylenediamine. These organic alkalis usually have better permeability, which helps to improve the penetration power of the film stripping solution, enabling the film stripping solution to act more deeply on the metal surface.

[0026] The penetrant enhances the penetration ability of the film stripping solution, making it more effectively penetrate the film layer on the metal surface.

[0027] 10 - hydroxy - 18 - [2 - [2 - (sulfonyloxy)ethoxy] is a surfactant, which helps to improve the wettability of the solution, thereby enhancing the penetration power.

[0028] Estriol trisulfate trisodium salt has the function of increasing the wettability and permeability of the solution.

[0029] Sulfated castor oil may help to reduce the friction during the film stripping process.

[0030] Sucrose fatty acid ester may act as an emulsifier, which helps to maintain the stability of the solution.

[0031] Bis(1 - methyl - 2 - hydroxyethyl) ether may act as a solvent or co - solvent to help dissolve other components.

[0032] Ethylene glycol dimethyl ether, as an organic solvent, helps to dissolve the compound alkali and other components, and may also provide certain penetration and cleaning effects.

[0033] The corrosion inhibitor protects the metal surface during the film stripping process to prevent excessive corrosion.

[0034] Octadecyl phosphate, as a component of the corrosion inhibitor, reduces the corrosion of the metal surface.

[0035] Oleic acid is used as a corrosion inhibitor, which helps to protect the metal from being eroded by the active components in the stripping solution.

[0036] Sodium molybdate, as a component of the corrosion inhibitor, improves the corrosion resistance of the metal.

[0037] Sodium nitrate, as a component of the corrosion inhibitor, may be used to adjust the pH value of the solution.

[0038] Benzotriazole is a commonly used metal corrosion inhibitor.

[0039] Zinc sulfate is part of the corrosion inhibitor.

[0040] The compound defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol, and is used to control the foam generated during the preparation of the solution, ensuring the stability and performance of the solution.

[0041] Through the synergistic effect of these substances, the stripping solution of the present invention can effectively remove the film layer on the metal surface while protecting the metal from corrosion, improving the stripping efficiency and the quality of metal surface treatment.

[0042] Compared with the prior art, it has the following beneficial effects:

[0043] 1) Through the synergistic effect of the specific compound base and penetrant in the stripping solution of the present invention, the stripping solution can strip the film layer on the metal surface faster, thereby improving the stripping efficiency.

[0044] 2) After stripping, the surface of the substrate by the stripping solution of the present invention is clean, without residue or fine residue, which helps to improve the quality of subsequent processes and reduce cleaning work.

[0045] 3) The specific mass ratio of the compound base and corrosion inhibitor and the special formulation of the penetrant in the stripping solution of the present invention improve the activity and selectivity of the stripping solution and reduce the corrosion of the substrate.

[0046] 4) Due to the high efficiency of the stripping solution of the present invention, the stripping time can be shortened, thereby improving the overall production efficiency. Specific Embodiments

[0047] Main sources of substances:

[0048] 10-Hydroxy-18-[2-[2-(sulfonyloxy)ethoxy]: CAS: 85153-73-7.

[0049] Sodium lauryl polyether sulfate: CAS: 3088-31-1.

[0050] Estriol trisulfate trisodium salt: CAS: 100940-55-4.

[0051] Sulfated castor oil: CAS: 8002-33-3.

[0052] Bis(1-methyl-2-hydroxyethyl) ether: CAS: 108-61-2.

[0053] Sucrose fatty acid ester: CAS No.: 37318-31-3.

[0054] Sorbitan fatty acid ester: Jinan Fland Chemical Co., Ltd., Model: S-80.

[0055] Polyethylene glycol: Guangzhou Nacheng Chemical Co., Ltd., Model: 400#.

[0056] Commercially available penetrant: Jiangsu Haian Petrochemical Factory, Product Number: JFC-E.

[0057] A method for preparing a stripping solution according to the present invention aims to improve the stripping efficiency. Stripping solutions are usually used in industrial production, especially in the process of metal surface treatment, to remove coatings or films on the metal surface.

[0058] A stripping solution capable of improving the stripping efficiency is composed of the following components in parts by weight: 25 - 35 parts of composite alkali, 10 - 20 parts of penetrant, 5 - 10 parts of organic solvent, 1 - 4 parts of corrosion inhibitor, and 40 - 50 parts of water.

[0059] The composite alkali is composed of inorganic alkali and organic alkali in a mass ratio of 10 - 15:1 - 3. The inorganic alkali is composed of sodium hydroxide, potassium hydroxide, and sodium carbonate in a mass ratio of 8 - 10:2 - 4:1; the organic alkali is composed of ethanolamine and propylenediamine in a mass ratio of 0.7 - 0.9:1 - 1.5.

[0060] The present invention first mixes the composite alkali (composed of inorganic alkali and organic alkali) with the penetrant and ethylene glycol dimethyl ether. The composition of the composite alkali is crucial because it determines the chemical properties and stripping ability of the stripping solution.

[0061] Inorganic alkalis: sodium hydroxide, potassium hydroxide, sodium carbonate. These strong alkalis provide the basic chemical activity of the stripping solution.

[0062] Organic alkalis: ethanolamine, propylenediamine. These organic alkalis enhance the permeability and stripping ability of the composite alkali.

[0063] The organic solvent is one or more of ethylene glycol dimethyl ether, cyclohexanone, and ethyl acetate.

[0064] The corrosion inhibitor is composed of octadecyl phosphate, oleic acid, sodium molybdate, sodium nitrate, benzotriazole, and zinc sulfate in a mass ratio of 9-11:9-11:2-4:40-60:6-8:18-22.

[0065] Adding a corrosion inhibitor to the mixed solution, these substances can slow down or prevent the corrosion of the metal surface, protecting the metal from being overly eroded by the active components in the stripping solution.

[0066] A preparation method of a stripping solution that can improve the stripping efficiency is as follows:

[0067] Step 1: Weigh each raw material according to parts by weight. Mix the composite base, penetrant, organic solvent, and water, then add them to a stirring kettle. While heating and stirring, control the heating temperature at 50-60 °C, the stirring rate at 100-200 revolutions per minute, and the stirring time for 20-40 minutes. Then cool to room temperature to obtain a mixed solution.

[0068] Step 2: Add water and a corrosion inhibitor to the mixed solution prepared in Step 1, then stir at room temperature. The stirring rate is 400-600 revolutions per minute, and the time is 100-150 minutes to obtain a stripping solution.

[0069] During the heating and stirring process, various components are fully mixed to form a uniform solution, which helps to improve the uniformity and stability of the stripping solution.

[0070] The preparation method of the penetrant is as follows, in parts by weight:

[0071] S1: Add 400-600 parts of water to a reaction kettle and preheat it to 40-60 °C. Gradually add 10-15 parts of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 13-16 parts of estriol trisulfate trisodium salt, and 20-30 parts of sulfated castor oil to the water. After adding each raw material, stir until completely dissolved, and continue to stir at 40-60 °C for 20-40 minutes to obtain a uniform solution.

[0072] S2: While stirring, add 4-6 parts of an emulsifier and 7-9 parts of bis(1-methyl-2-hydroxyethyl) ether, and continue to stir for 5-15 minutes; add 1-3 parts of a composite defoamer; continue to stir until the defoamer is completely dispersed, and use a microporous filter for filtration to remove possible solid particles or insoluble substances to obtain a penetrant.

[0073] The emulsifier is sucrose fatty acid ester.

[0074] The composite defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 0.8-1.2:1-3:0.8-1.2.

[0075] The pore size of the micro-porous filter is 0.4 - 0.5 μm.

[0076] The preparation of the penetrant includes multiple components, such as 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], estriol trisulfate trisodium salt, sulfated castor oil, etc. These components help to improve the permeability of the film stripping solution, enabling it to better penetrate and remove the film layer on the metal surface.

[0077] Through the synergistic effect of the composite base and the penetrant, the film stripping solution can more effectively penetrate and remove the film layer on the metal surface.

[0078] Example 1

[0079] A method for preparing a film stripping solution that can improve the film stripping efficiency is as follows:

[0080] Step 1: Mix 30 g of the composite base, 15 g of the penetrant, 8 g of ethylene glycol dimethyl ether, and 29 g of water, then add them to a stirring kettle. Stir while heating, control the heating temperature at 55 °C, the stirring rate at 150 revolutions per minute, and the stirring time for 30 minutes. Then cool to room temperature to obtain a mixed solution;

[0081] Step 2: Add 15 g of water and 3 g of the corrosion inhibitor to the mixed solution prepared in Step 1, then stir at room temperature, with a stirring rate of 500 revolutions per minute and a time of 120 minutes to obtain the film stripping solution.

[0082] The composite base is composed of an inorganic base and an organic base in a mass ratio of 13:2. The inorganic base is composed of sodium hydroxide, potassium hydroxide, and sodium carbonate in a mass ratio of 9:3:1; the organic base is composed of ethanolamine and propylenediamine in a mass ratio of 0.8:1.2;

[0083] The corrosion inhibitor is composed of octadecyl phosphate, oleic acid, sodium molybdate, sodium nitrate, benzotriazole, and zinc sulfate in a mass ratio of 10:10:3:50:7:20.

[0084] The preparation method of the penetrant is as follows:

[0085] S1: Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of estriol trisulfate trisodium salt, and 25 g of sulfated castor oil to the water. Stir until each raw material is completely dissolved after adding. Maintain at 50 °C and continue stirring for 30 minutes to obtain a uniform solution;

[0086] S2. With stirring, add 5 g of sucrose fatty acid ester and 8 g of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 10 minutes; add 2 g of a compound defoamer, where the compound defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles to obtain a penetrant.

[0087] Example 2

[0088] The preparation method of a film stripping solution that can improve the film stripping efficiency is basically the same as that of Example 1, the only difference being that the preparation method of the penetrant is different:

[0089] The preparation method of the penetrant is as follows:

[0090] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of sodium lauryl polyether sulfate, 15 g of estriol trisulfate trisodium salt, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until it is completely dissolved, and continue stirring at 50 °C for 30 minutes to obtain a homogeneous solution;

[0091] S2. With stirring, add 5 g of sucrose fatty acid ester and 8 g of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 10 minutes; add 2 g of a compound defoamer, where the compound defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles to obtain a penetrant.

[0092] Example 3

[0093] The preparation method of a film stripping solution that can improve the film stripping efficiency is basically the same as that of Example 1, the only difference being that the preparation method of the penetrant is different:

[0094] The preparation method of the penetrant is as follows:

[0095] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of 2-ethyl-3-hydroxyhexyl sodium sulfate, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until it is completely dissolved, and continue stirring at 50 °C for 30 minutes to obtain a homogeneous solution;

[0096] S2. Under stirring, add 5 g of sucrose fatty acid ester and 8 g of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 10 minutes; add 2 g of a composite defoamer, where the composite defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles, obtaining a penetrant.

[0097] Example 4

[0098] The preparation method of a stripping solution that can improve the stripping efficiency is basically the same as that of Example 1, except that the preparation method of the penetrant is different:

[0099] The preparation method of the penetrant is as follows:

[0100] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of sodium 2-ethylhexyl sulfate, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until completely dissolved, and continue stirring at 50 °C for 30 minutes to obtain a homogeneous solution;

[0101] S2. Under stirring, add 5 g of sucrose fatty acid ester and 8 g of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 10 minutes; add 2 g of a composite defoamer, where the composite defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles, obtaining a penetrant.

[0102] Example 5

[0103] The preparation method of a stripping solution that can improve the stripping efficiency is basically the same as that of Example 1, except that the preparation method of the penetrant is different:

[0104] The preparation method of the penetrant is as follows:

[0105] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of estriol trisulfate trisodium salt, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until completely dissolved, and continue stirring at 50 °C for 30 minutes to obtain a homogeneous solution;

[0106] S2. With stirring, add 5 g of cetearyl glucoside and 8 g of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 10 minutes; add 2 g of a compound defoamer, which is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles, obtaining a penetrant.

[0107] Example 6

[0108] The preparation method of a stripping solution that can improve the stripping efficiency is basically the same as that of Example 1, except that the preparation method of the penetrant is different:

[0109] The preparation method of the penetrant is as follows:

[0110] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of estriol trisulfate trisodium salt, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until it is completely dissolved, and continue stirring at 50 °C for 30 minutes to obtain a homogeneous solution;

[0111] S2. With stirring, add 5 g of sucrose fatty acid ester and 8 g of triethylene glycol monoisopropyl ether, and continue stirring for 10 minutes; add 2 g of a compound defoamer, which is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles, obtaining a penetrant.

[0112] Example 7

[0113] The preparation method of a stripping solution that can improve the stripping efficiency is basically the same as that of Example 1, except that the preparation method of the penetrant is different:

[0114] The preparation method of the penetrant is as follows:

[0115] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of estriol trisulfate trisodium salt, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until it is completely dissolved, and continue stirring at 50 °C for 30 minutes to obtain a homogeneous solution;

[0116] S2. Under stirring, add 5 g of sucrose fatty acid ester and 8 g of diethylene glycol tert-butyl ether, and continue stirring for 10 minutes; add 2 g of a compound defoamer, where the compound defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 1:2:1; continue stirring until the defoamer is completely dispersed, and filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles, obtaining a penetrant.

[0117] Comparative Example 1

[0118] The preparation method of a stripping solution that can improve the stripping efficiency is basically the same as that of Example 1, except that the preparation method of the penetrant is different:

[0119] The preparation method of the penetrant is as follows:

[0120] S1. Add 500 g of water to a reaction kettle and preheat it to 50 °C. Gradually add 12 g of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], 15 g of estriol trisulfate trisodium salt, and 25 g of sulfated castor oil to the water. After each raw material is added, stir until completely dissolved, maintain at 50 °C and continue stirring for 30 minutes to obtain a homogeneous solution;

[0121] S2. Under stirring, add 5 g of sucrose fatty acid ester and 8 g of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 10 minutes; filter using a microporous filter with a pore size of 0.45 μm to remove possible solid particles or insolubles, obtaining a penetrant.

[0122] Comparative Example 2

[0123] The preparation method of a stripping solution that can improve the stripping efficiency is as follows:

[0124] Step 1. Mix 30 g of compound base, 15 g of commercially available penetrant, 8 g of ethylene glycol dimethyl ether, and 29 g of water, and add them to a stirring kettle. Stir while heating, control the heating temperature at 55 °C, control the stirring rate at 150 revolutions per minute, and stir for 30 minutes. Then cool to room temperature to obtain a mixed solution;

[0125] Step 2. Add 15 g of water and 3 g of corrosion inhibitor to the mixed solution prepared in Step 1, and then stir at room temperature. The stirring rate is 500 revolutions per minute, and the time is 120 minutes to obtain a stripping solution.

[0126] The compound base is composed of inorganic base and organic base in a mass ratio of 13:2. The inorganic base is composed of sodium hydroxide, potassium hydroxide, and sodium carbonate in a mass ratio of 9:3:1; the organic base is composed of ethanolamine and propylenediamine in a mass ratio of 0.8:1.2.

[0127] The corrosion inhibitor is composed of octadecyl phosphate, oleic acid, sodium molybdate, sodium nitrate, benzotriazole, and zinc sulfate in a mass ratio of 10:10:3:50:7:20.

[0128] Comparative Example 3

[0129] A method for preparing a stripping solution that can improve the stripping efficiency is as follows:

[0130] Step 1: Mix 30 g of composite base, 8 g of ethylene glycol dimethyl ether, and 29 g of water, then add them to a stirring kettle. Stir while heating, control the heating temperature at 55 °C, control the stirring rate at 150 revolutions per minute, and stir for 30 minutes. Then cool to room temperature to obtain a mixed solution.

[0131] Step 2: Add 15 g of water and 3 g of corrosion inhibitor to the mixed solution prepared in Step 1, then stir at room temperature, with a stirring rate of 500 revolutions per minute and a time of 120 minutes to obtain the stripping solution.

[0132] The composite base is composed of inorganic base and organic base in a mass ratio of 13:2. The inorganic base is composed of sodium hydroxide, potassium hydroxide, and sodium carbonate in a mass ratio of 9:3:1; the organic base is composed of ethanolamine and propylenediamine in a mass ratio of 0.8:1.2.

[0133] The corrosion inhibitor is composed of octadecyl phosphate, oleic acid, sodium molybdate, sodium nitrate, benzotriazole, and zinc sulfate in a mass ratio of 10:10:3:50:7:20.

[0134] Test Example 1

[0135] Stripping ability test

[0136] Use the stripping solutions prepared in the examples and comparative examples to perform stripping treatment on the ultra-fine circuits of printed circuit boards respectively. Treatment conditions: stripping solution spraying pressure 1.8 kg / cm 2 , stripping solution use temperature 50 °C, line width / dry film width = 30 / 30 um, dry film thickness 50 um. Record the time required for stripping. Take the average value of the stripping time, and the test results are shown in Table 1.

[0137] Table 1

[0138]

[0139]

[0140] Test Example 2

[0141] Residue inspection

[0142] For the substrate surface after stripping in Test Example 1, use a microscope or high-power magnifying glass to check and confirm whether there are residues of dry film or other materials. The test results are shown in Table 2.

[0143] Table 2

[0144] Experimental Scheme Residue Inspection Example 1 Clean, no residue Example 2 Clean, with fine residues Example 3 Clean, with fine residues Example 4 Clean, with fine residues Example 5 Clean, with fine residues Example 6 Clean, with fine residues Example 7 Clean, with fine residues Comparative Example 1 Not clean, with partial residues Comparative Example 2 Not clean, with partial residues Comparative Example 3 Not clean, with large residues

[0145] As can be seen from Test Examples 1 to 2, the stripping solution obtained in Example 1 of the present invention has a shorter stripping time and less residue after stripping.

[0146] In Example 1 of the present invention, the penetrant component 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy] has a specific chemical structure, which shows better stripping efficiency and less residue compared with sodium lauryl polyether sulfate used in Example 2. 10-Hydroxy-18-[2-[2-(sulfonyloxy)ethoxy] may have a longer carbon chain and sulfonate groups, which increases its wetting and penetration ability in the dry film. The long-chain structure helps to better interact with the polymer chains of the dry film and promote peeling. The sulfonate groups may form strong interactions with the polar groups in the dry film material through ionic interactions, which helps to improve the peeling efficiency. Due to the molecular structure of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy], it may have better intermolecular forces, such as hydrogen bonding, which may enhance its interaction with the dry film, thereby improving the peeling efficiency. The interaction is stronger, and it may be easier to remove from the substrate surface after stripping, thus reducing the residue.

[0147] In Example 1 of the present invention, the use of sodium estriol trisulfate shows more excellent stripping efficiency and less residue compared with sodium 2-ethyl-3-hydroxyhexyl sulfate used in Example 3 and sodium 2-ethylhexyl sulfate used in Example 4. Sodium estriol trisulfate has three sulfate groups, which increases its solubility and wettability in water, and thus may improve its spreading and penetration on the surface of the dry film. Due to the hydrophilicity of the sulfate groups, sodium estriol trisulfate may form a thinner liquid film on the surface of the dry film, which helps to improve the wettability and spreading, which are key factors for the stripping efficiency. The sulfate groups may form strong interactions with the polar groups in the dry film material through ionic interactions, which helps to improve the peeling efficiency.

[0148] 10-Hydroxy-18-[2-[2-(sulfonyloxy)ethoxy] is an anionic surfactant with a sulfate group and a sulfonate group. Similarly, estriol trisulfate trisodium salt is also an anionic surfactant with multiple sulfate groups. In an aqueous solution, these charged groups can be attracted to each other through charge interactions to form a micelle structure. This structure helps to improve the stability and foam properties of the solution. There may be hydrogen bonding between the hydroxyl group in 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy] and estriol trisulfate trisodium salt. Hydrogen bond is a relatively strong non-covalent interaction that can enhance the intermolecular binding force, thus affecting the physical and chemical properties of the solution. The structures of 10-hydroxy-18-[2-[2-(sulfonyloxy)ethoxy] and estriol trisulfate trisodium salt complement each other in an aqueous solution to form a more stable and effective surfactant system, involving charge interactions, hydrogen bonding and possible synergistic effects. These interactions together determine the properties of the mixed solution, including surface tension and foam stability, thus affecting its application effect in the stripping solution.

[0149] In Example 1 of the present invention, sucrose fatty acid ester is used, while cetearyl glucoside is used in Example 5. Sucrose fatty acid ester may have a more suitable hydrophilic-lipophilic balance, which makes it more effective as a surfactant in the stripping solution, capable of better reducing the surface tension between water and the dry film, thus improving wettability and permeability. The molecular structure of sucrose fatty acid ester may help it to better penetrate into the microstructure of the dry film, which may be due to its molecular size and shape being more suitable for the pores of the dry film.

[0150] Comparing Example 1 with Examples 6 and 7, from the perspective of molecular structure, the shorter alkyl chain of bis(1-methyl-2-hydroxyethyl) ether may make it easier to penetrate and disperse, thus improving the stripping efficiency. In addition, the hydrophilic part of bis(1-methyl-2-hydroxyethyl) ether may contribute to its stability and emulsifying ability in an aqueous solution.

[0151] Compared with Comparative Example 1, the composite defoamer plays an important role in the preparation process of the stripping solution. The role of the defoamer is to reduce or eliminate the foam in the solution, improving the clarity and usage efficiency of the stripping solution. During the stripping process, the foam may affect the permeability of the stripping solution and the cleaning effect on the film layer. Therefore, adding a defoamer helps to maintain the stability of the solution and improve the stripping efficiency. The composite defoamer usually consists of multiple surfactants and additives to provide a synergistic effect, thus reducing foam more effectively. The composite defoamer used in the present invention is composed of polyethylene glycol, sorbitan fatty acid ester and isopropanol in a mass ratio of 1:2:1, which can provide excellent defoaming performance. Polyethylene glycol may reduce the surface tension and decrease the formation of foam. Sorbitan fatty acid ester may inhibit the growth of foam by adsorbing on the foam surface. Isopropanol may accelerate the rupture of foam by reducing the surface tension. By adding the composite defoamer, the stability of the stripping solution is improved, which helps to enhance the stripping efficiency and the film layer cleanliness. The selection and dosage of the defoamer need to be optimized according to the specific application conditions and the performance requirements of the stripping solution.

Claims

1. A film stripping solution capable of improving film stripping efficiency, characterized in that: The method is composed of the following components in parts by weight: 25-35 parts of composite alkali, 10-20 parts of penetrant, 5-10 parts of organic solvent, 1-4 parts of corrosion inhibitor, and 40-50 parts of water; The composite base is composed of an inorganic base and an organic base in a mass ratio of 10-15:1-3, the inorganic base is composed of sodium hydroxide, potassium hydroxide, and sodium carbonate in a mass ratio of 8-10:2-4:1; the organic base is composed of ethanolamine and propylenediamine in a mass ratio of 0.7-0.9:1-1.5; The preparation method of the penetrant is as follows, in parts by weight: S1, add 400-600 parts of water to the reactor and preheat to 40-60°C, gradually add 10-15 parts of 10-hydroxy-18-[2-[2-(sulfonic acid group oxy) ethoxy, 13-16 parts of estriol trisulfate trisodium salt and 20-30 parts of sulfated castor oil to the water, stir each raw material until it is completely dissolved, maintain 40-60°C and continue stirring for 20-40 minutes to obtain a uniform solution; S2. Under stirring, add 4 to 6 parts of emulsifier and 7 to 9 parts of bis(1-methyl-2-hydroxyethyl) ether, and continue stirring for 5 to 15 minutes; add 1 to 3 parts of composite defoamer; continue stirring until the defoamer is completely dispersed, and filter with a microporous filter to remove possible solid particles to obtain a penetrant; The emulsifier is sucrose fatty acid ester; The composite defoamer is composed of polyethylene glycol, sorbitan fatty acid ester, and isopropanol in a mass ratio of 0.8-1.2:1-3:0.8-1.2; The pore size of the microporous filter is 0.4-0.5 μm; The corrosion inhibitor is composed of octadecyl phosphate, oleic acid, sodium molybdate, sodium nitrate, benzotriazole and zinc sulfate in a mass ratio of 9-11:9-11:2-4:40-60:6-8:18-22.

2. The film stripping solution capable of improving film stripping efficiency as claimed in claim 1, characterized in that: The organic solvent is one or more of ethylene glycol dimethyl ether, cyclohexanone and ethyl acetate.

3. A method for preparing a stripping solution capable of improving stripping efficiency as claimed in any one of claims 1 to 2, characterized in that: Here’s how: Step 1, weighing each raw material according to weight, mixing the composite base, penetrant, organic solvent and water, adding them into a stirring kettle, heating and stirring, the heating temperature is controlled at 50-60°C, the stirring rate is controlled at 100-200 rpm, the stirring time is 20-40 minutes, and then cooling to room temperature to obtain a mixed solution; Step 2: Add water and corrosion inhibitor to the mixed solution prepared in step 1, and then stir at room temperature at a stirring rate of 400-600 rpm for 100-150 minutes to obtain a stripping solution.

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