Aqueous paint stripper and method of making same

Abstract

The application provides an aqueous paint remover and a preparation method thereof. The aqueous paint remover is prepared from the following raw materials with the following weight percentage: 50.0-60.0% of a main solvent, 10.0-40.0% of an auxiliary solvent, 1.0-2.0% of a thickening agent, 1.0-3.0% of a surfactant, 0.5-1.0% of a settling agent and 3.0-4.0% of an accelerator. The paint remover is composed of multiple raw materials, and after the addition of the defined surfactant and settling agent, the raw materials cooperate and promote each other, improve the paint removal efficiency, make the paint residue easily and quickly settle and clean, prolong the effective use time of the paint remover and the stability of paint removal, and are suitable for the automatic production of paint removal treatment. Due to the good adaptation of the settling agent and the surfactant, the solubility of the raw materials in the solvent is ensured, and the adhesion between the paint film and the substrate and the paint removal efficiency will not be reduced. Due to the use of raw materials with high ignition point, the safety performance is improved, and the raw materials are pollution-free.

Description

Technical Field

[0001] This invention relates to the technical field of removing paint films from object surfaces, and more particularly to a water-based paint remover suitable for automatically removing polyurethane, phenolic resin, epoxy, and other paint films, and its preparation method. Background Technology

[0002] Currently, paint removers are widely used in the paint removal and decontamination processes of various metal workpieces in fields such as machinery, power, automobiles, instruments, and shipbuilding. They can also be used for paint removal on non-metallic surfaces such as stone, ceramics, wood, plastics, and glass, and are particularly suitable for removing polyurethane, phenolic resin, and epoxy paint films. For example, a cleaning and paint remover material for the electronics industry, provided by existing technology, consists of the following components by weight percentage: 2-methylpentane 45-70%; anhydrous ethanol 15-25%; isopropanol 5-10%; and ether solvents 10-20%. The main solvent, 2-methylpentane, has particularly good dissolving power for rosin in flux used in electronic products; the ether solvent has good dissolving power for polar substances such as organic acids in flux; and anhydrous ethanol has a good removal effect on oil stains. This product does not contain harmful halogenated hydrocarbons, does not deplete the ozone layer, and is essentially harmless to the human body, thus gaining widespread application. There are also some cleaning agents commonly used for removing road marking paint, which include N-methylpyrrolidone and benzaldehyde, ethanol, formic acid and phosphoric acid, butyl acetate and isoamyl acetate, etc. These cleaning agents have high paint removal efficiency, are non-toxic and harmless, and are widely used for paint removal from inorganic materials such as stone, ceramics, and glass. With the rapid development of paint removal material technology in my country and the increasing environmental awareness, the requirements for paint removal materials are also becoming higher. Looking at the raw materials used in the formulations of the two types of paint removal materials mentioned above, the amount of ethanol solvent used in both is considerable. Ethanol is a flammable and explosive liquid, with poor safety for humans and the environment, leaving significant safety loopholes in the production process. Furthermore, for automated paint removal operations, such as the automated removal of paint from the surface of metal workpieces, the existing paint removal materials cause the paint residue to float in the cleaning material after removal, making it difficult to settle and be cleaned in a timely manner, which is unsuitable for automated paint removal. It also easily causes the cleaning material to deteriorate, shortening its effective service life and reducing the stability of paint removal.

[0003] Therefore, overcoming the shortcomings of existing cleaning and paint stripping materials, such as safety hazards, long paint stripping time, unsatisfactory paint stripping effect, and inability to meet the needs of automated paint stripping production, is an urgent problem to be solved in this field. Summary of the Invention

[0004] This invention addresses the technical problems of existing paint stripping materials, such as safety hazards, long stripping times, unsatisfactory stripping effects, and inability to meet the needs of automated paint stripping production. It provides a highly efficient, safe, and environmentally friendly water-based paint stripper and its preparation method. This paint stripper can meet the requirements of automated production.

[0005] The present invention provides a water-based paint remover, which is formulated from the following raw materials in the indicated weight percentages:

[0006] Main solvent 50.0–60.0%, co-solvent 10.0–40.0%, thickener 1.0–2.0%,

[0007] Surfactant 1.0-3.0%, flocculant 0.5-1.0%, accelerator 3.0-4.0%.

[0008] Preferably, the main solvent is one or two of benzyl alcohol, benzaldehyde, N-methyl-2-pyrrolidone, benzoic acid, or isohexanediol.

[0009] Preferably, the co-solvent is at least one of 2-methyl-2,4-pentanediol, ethanolamine, propylene glycol, or water.

[0010] Preferably, the thickener is polyvinyl alcohol and / or polyethylene glycol.

[0011] Preferably, the surfactant is one or two of sodium polymethacrylate, nonylphenol polyoxyethylene ether, polystyrene sulfonic acid, or 3-hydroxypropanesulfonic acid.

[0012] Preferably, the settling agent is polyacrylamide or its derivatives.

[0013] Preferably, the accelerator is a compound of potassium hydroxide and ester-based quaternary ammonium salt.

[0014] The method for preparing the water-based paint remover provided by the present invention includes the following steps:

[0015] Step 1: Slowly add the main solvent and the co-solvent into a beaker, and stir for a set time to obtain a mixture;

[0016] Step 2: Slowly add the surfactant to the primary mixture and mix thoroughly to obtain the secondary mixture;

[0017] Step 3: Add the thickener and settling agent to the secondary mixture, and stir at the set speed for the set time to obtain the tertiary mixture;

[0018] Step 4: Heat the three-component mixture to a set temperature, then add the accelerator, and use ultrasound to mix thoroughly for a set time to obtain the water-based paint remover.

[0019] Preferably, in step 1, the stirring time is 30-40 minutes.

[0020] Preferably, in step 3, the mixture is stirred at a speed of 100-120 r / min for 25-35 min.

[0021] Preferably, in step 4, the three-stage mixture is heated to 60-65°C and mixed using ultrasound for 15-25 minutes.

[0022] The paint remover provided by this invention comprises a complete system of multiple raw materials. In particular, the addition of the aforementioned surfactant and flocculant enhances the synergistic effect and compatibility of the raw materials. While improving paint removal efficiency, it also facilitates the rapid aggregation and settling of the removed paint residue, enabling timely cleaning and solving the problem of difficult paint residue recovery after paint removal. Due to the favorable compatibility between the flocculant and surfactant, optimal solubility of each raw material in the solvent is ensured, without reducing the adhesion between the paint film and the substrate or the paint removal efficiency. The ease of timely paint residue removal extends the effective service life of the paint remover, maintains the stability of the paint removal effect after multiple removals, and meets the requirements of continuous and stable paint removal on the workpiece surface in automated production lines, thus improving the efficiency of automated production lines. The paint remover of this invention does not use flammable and explosive ethanol solvents, maintaining a stable and rapid dissolution and paint removal effect. The paint remover of this invention uses raw materials with high flash points, lacking flammable and explosive properties, greatly improving safety. The raw materials are non-polluting, and the paint remover does not damage the substrate after removal. Attached Figure Description

[0023] Figure 1 This is a comparative schematic diagram of the test panel surface before and after paint removal in Embodiment 4 of the present invention;

[0024] Figure 2 This is a comparative schematic diagram of the test panel before and after paint removal in Example 6;

[0025] Figure 3 This is a comparative schematic diagram of the test panel surface before and after paint removal in Example 7;

[0026] Figure 4 This is a comparative schematic diagram showing the surface of the test panel in Comparative Example 1 before and after paint removal.

[0027] The lower half of the test panel in the figure shows the surface without paint stripping treatment, while the upper half shows the surface after paint stripping treatment. Detailed Implementation

[0028] The water-based paint remover proposed in this invention is formulated from the following raw materials in the indicated weight percentages:

[0029] Main solvent 50.0–60.0%, co-solvent 10.0–40.0%, thickener 1.0–2.0%.

[0030] Surfactant 1.0-3.0%, flocculant 0.5-1.0%, accelerator 3.0-4.0%.

[0031] The main solvent is one or a combination of two of benzyl alcohol, benzaldehyde, N-methyl-2-pyrrolidone, benzoic acid, or isohexanediol. It is non-toxic, safe, and environmentally friendly, significantly reducing the complexity of the process, increased paint stripping costs, and the problems associated with the disposal and recycling of waste organic solvents caused by their volatilization. Because the main solvent is an aromatic alcohol, its molecules easily penetrate the paint film, thus improving the paint stripping rate.

[0032] The co-solvent is one or a combination of two or more of 2-methyl-2,4-pentanediol, ethanolamine, propylene glycol, and water. As an excellent alcohol ether solvent, it works synergistically with the main solvent molecules to fully penetrate the paint film, thereby increasing the paint removal rate while reducing the amount of main solvent used and lowering costs.

[0033] The thickener is polyvinyl alcohol or polyethylene glycol, or a mixture of polyvinyl alcohol and polyethylene glycol. The thickener increases the viscosity of the system, allowing the paint remover to adhere to the surface of the workpiece and react fully, thus increasing the paint removal rate.

[0034] The surfactant is one or a combination of two of sodium polymethacrylate, nonylphenol polyoxyethylene ether, polystyrene sulfonic acid, or 3-hydroxypropanesulfonic acid. These surfactants, specifically defined in this invention, improve the compatibility of the various raw materials in the paint remover, significantly increasing its solubility in the solvent, thereby effectively reducing the adhesion between the paint film and the substrate and improving paint removal efficiency. Furthermore, they also help improve the storage stability of the paint remover and facilitate subsequent water rinsing for paint removal.

[0035] The flocculant is specifically selected from polyacrylamide and its derivatives. It allows the paint film to detach and form flocculent material, which then settles at the bottom of the container for easy cleaning, maintaining the effective use time of the paint remover and making it suitable for automated paint removal processes. Furthermore, the flocculant raw materials specified in this invention are compatible with the surfactants mentioned above; that is, the specified flocculant does not reduce the compatibility between the various raw materials of the paint remover, ensuring optimal solubility of each raw material in the solvent and maintaining effective reduction of adhesion between the paint film and the substrate, as well as paint removal efficiency. This is an unexpected and beneficial effect obtained through in-depth research and repeated experiments.

[0036] The accelerator is a compound of potassium hydroxide and ester-based quaternary ammonium salt. By hydrolyzing the ester bonds in the polyester, it reduces the adhesion between paint films, thereby allowing it to be removed from the substrate.

[0037] The preparation method of the water-based paint remover provided by the present invention comprises the following steps:

[0038] Step 1: Slowly add the main solvent and the co-solvent to the beaker, stirring for 30-40 minutes to obtain a primary mixture;

[0039] Step 2: Slowly add the surfactant to the primary mixture and mix thoroughly to obtain the secondary mixture;

[0040] Step 3: Add the thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain the tertiary mixture;

[0041] Step 4: Heat the three-component mixture to 60-65°C, then add the accelerator, and use an ultrasonic device to mix it thoroughly for 15-25 minutes to obtain the water-based paint remover.

[0042] The present invention will be further illustrated below through examples. Based on the technical solution of the paint remover protection according to the present invention, the following five examples and two comparative examples are given, as shown in Table 1:

[0043] Table 1. Formulation composition of the examples and comparative examples (raw material amounts are by weight percentage).

[0044]

[0045] The method for preparing the paint remover according to the present invention is derived from the preparation of samples of five embodiments.

[0046] Example 1:

[0047] 50g benzyl alcohol, 20g 2methyl-2,4-pentanediol, 10g ethanolamine, 10g water, 2g polyethylene glycol, 2g polystyrene sulfonic acid, 1g nonylphenol polyoxyethylene ether, 1g polyacrylamide, 3g potassium hydroxide, and 1g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0048] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0049] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0050] Add thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain a tertiary mixture;

[0051] The three mixtures are heated to 60-65°C, then an accelerator is added, and the mixture is thoroughly mixed using ultrasound for 15-25 minutes to obtain the water-based paint remover.

[0052] Example 2:

[0053] 43g benzyl alcohol, 15g N-methyl-2-pyrrolidone, 15g 2-methyl-2,4-pentanediol, 5g ethanolamine, 13g water, 1.8g polyethylene glycol, 1g polystyrene sulfonic acid, 2g nonylphenol polyoxyethylene ether, 0.7g polyacrylamide, 3g potassium hydroxide, and 0.5g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0054] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0055] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0056] Add thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain a tertiary mixture;

[0057] The three mixtures are heated to 60-65°C, then an accelerator is added, and the mixture is thoroughly mixed using ultrasound for 15-25 minutes to obtain the water-based paint remover.

[0058] Example 3:

[0059] 60g benzyl alcohol, 15g 2-methyl-2,4-pentanediol, 5g ethanolamine, 10g water, 2g polyethylene glycol, 3g polystyrene sulfonic acid, 1g polyacrylamide, 2g potassium hydroxide, and 2g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0060] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0061] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0062] Add thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain a tertiary mixture;

[0063] The three mixtures are heated to 60-65°C, then an accelerator is added, and the mixture is thoroughly mixed using ultrasound for 15-25 minutes to obtain the water-based paint remover.

[0064] Example 4:

[0065] 40g benzyl alcohol, 17.5g N-methyl-2-pyrrolidone, 20g 2,4-pentanediol, 5g ethanolamine, 10g water, 1.5g polyethylene glycol, 1.5g polystyrene sulfonic acid, 0.6g nonylphenol polyoxyethylene ether, 0.9g polyacrylamide, 2g potassium hydroxide, and 1g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0066] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0067] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0068] Add thickener and settling agent to the secondary mixture, stir at 100-120 r / min for 25-35 min to obtain tertiary mixture; then add accelerator at 60-65℃, and mix thoroughly with ultrasound for 15-25 min to obtain the water-based paint remover.

[0069] Example 5:

[0070] 45g benzyl alcohol, 10g N-methyl-2-pyrrolidone, 25g 2,4-pentanediol, 5g ethanolamine, 8g water, 1.5g polyethylene glycol, 1g polystyrene sulfonic acid, 1g nonylphenol polyoxyethylene ether, 0.5g polyacrylamide, 2g potassium hydroxide, and 1g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0071] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0072] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0073] Add thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain a tertiary mixture;

[0074] The three mixtures are heated to 60-65°C, then an accelerator is added, and the mixture is thoroughly mixed using ultrasound for 15-25 minutes to obtain the water-based paint remover.

[0075] Example 6:

[0076] 40g benzyl alcohol, 17.5g N-methyl-2-pyrrolidone, 20g 2,4-pentanediol, 5g ethanolamine, 10g water, 1.5g polyethylene glycol, 1.5g polystyrene sulfonic acid, 0.6g nonylphenol polyoxyethylene ether, 2g potassium hydroxide, and 1g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0077] In this Example 6, only a surfactant was added; no settling agent, polyacrylamide, was added.

[0078] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0079] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0080] Add thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain a tertiary mixture;

[0081] The three mixtures are heated to 60-65°C, then an accelerator is added, and the mixture is thoroughly mixed using ultrasound for 15-25 minutes to obtain the water-based paint remover.

[0082] Example 7:

[0083] 40g benzyl alcohol, 17.5g N-methyl-2-pyrrolidone, 20g 2,4-pentanediol, 5g ethanolamine, 10g water, 1.5g polyethylene glycol, 0.9g polyacrylamide, 2g potassium hydroxide, and 1g ester-based quaternary ammonium salt. Weigh the raw materials according to the above proportions.

[0084] In Example 7, only the settling agent polyacrylamide was added, and no surfactant was added.

[0085] Slowly add the main solvent and co-solvent to the beaker and stir for 30-40 minutes to obtain a primary mixture;

[0086] The surfactant is slowly added to the primary mixture and mixed thoroughly to obtain the secondary mixture;

[0087] Add thickener and settling agent to the secondary mixture, and stir at 100-120 r / min for 25-35 min to obtain a tertiary mixture;

[0088] The three mixtures are heated to 60-65°C, then an accelerator is added, and the mixture is thoroughly mixed using ultrasound for 15-25 minutes to obtain the water-based paint remover.

[0089] In addition to the raw materials used in the above embodiments, other preferred raw materials in the paint remover technical solution of the present invention can also be used. For example, the surfactant can also be polystyrene sulfonic acid and / or 3-hydroxypropanesulfonic acid. The dosage is similar, and the same technical effect is achieved. The paint remover of the present invention uses raw materials with high flash points and does not have flammable or explosive properties, greatly improving safety performance. At the same time, it keeps the raw materials uncontaminated and does not damage the substrate after paint removal.

[0090] Comparative Example 1:

[0091] 20g benzyl alcohol, 15g N-methyl-2-pyrrolidone, 50g ethanolamine, 6g water, 2g methylcellulose, 3g sodium dodecylbenzenesulfonate, 4g potassium hydroxide. Weigh out the amount of raw materials required for Comparative Example 1 according to the above proportions.

[0092] Slowly add benzyl alcohol, N-methyl-2-pyrrolidone, ethanolamine and water to a beaker and stir for 30-40 minutes to obtain a primary mixture; add methylcellulose and sodium dodecylbenzenesulfonate to the primary mixture and stir until homogeneous to obtain a secondary mixture; heat the secondary mixture to 60-65°C, then add an accelerator and mix thoroughly using ultrasound for 15-25 minutes to obtain the prior art paint remover 1.

[0093] Comparative Example 2:

[0094] 45g benzyl alcohol, 30g N-methyl-2-pyrrolidone, 17g ethanolamine, 2g methylcellulose, 2g sodium dodecylbenzenesulfonate, 4g potassium hydroxide. Weigh out the amount of raw materials required for Comparative Example 2 according to the above proportions.

[0095] The preparation method is similar to that of Comparative Example 1, and the paint remover 2 of the prior art is obtained.

[0096] The performance of the five embodiments and two comparative samples described above will be tested below.

[0097] 1. Testing instruments, equipment, and tools

[0098] The content of volatile organic compounds (VOCs) was determined by a balance, an oven, a Karl Fischer moisture analyzer, and a gas chromatography-mass spectrometry (GC-MS) system.

[0099] The total test for dichloromethane, trichloromethane, trichloroethylene, and tetrachloroethylene (i.e., the total test for four halogenated hydrocarbons) was performed using gas chromatography (GC).

[0100] Paint peeling time test: stopwatch, beaker

[0101] Test plate surface cleanliness: visual inspection

[0102] Settling properties: Graduated cylinder

[0103] 2. Standards for testing

[0104] The content of volatile organic compounds (VOCs) was tested in accordance with GB 38508 "Content of Volatile Organic Compounds in Cleaning Agents".

[0105] The total test for dichloromethane, trichloromethane, trichloroethylene, and tetrachloroethylene shall be conducted in accordance with GB / T 23992-2009.

[0106] Paint peeling time test was conducted in accordance with enterprise standard QJ / GD 41.13.242.

[0107] 3. Testing Steps

[0108] The specific steps for the paint stripping time test are as follows: Add 300ml of the paint stripper to a 500ml beaker and heat to 60℃. Place the test panel to be stripped: a test panel with a polyester powder coating of 110μm thickness. During the paint stripping process, stir with a glass rod to accelerate the coating removal, with a stirring frequency of about 2 times / s. After 3-5 minutes, remove the test panel and rinse it under tap water for about 10 seconds. Observe whether there is any residual coating on the test panel.

[0109] Settling properties: Prepare a plasticizer with a 3% solid content of paint sludge, i.e., the ratio of the mass of paint sludge to the mass of the plasticizer solution containing paint sludge is 3%. Preparation method: In a beaker containing 200±1g of plasticizer, heat to 60℃, then add 6.4±0.1g of crushed skin, and stir at a constant temperature for 3 minutes to dissolve. Immediately pour the plasticizer solution containing sludge into a 100ml graduated cylinder, mark to the graduation mark, and start timing. Observe the settling of the paint sludge after 30 minutes. If the settling interface drops below the 90ml mark, i.e., the settling rate is ≥10%, the settling effect is good.

[0110] Volatile organic compound (VOC) content detection and total test of four halogenated hydrocarbons.

[0111] Table 2 Test results of embodiments and comparative examples of the present invention

[0112]

[0113] Note: ND is a term specific to test results, meaning not detected.

[0114] The test results from the examples and comparative examples show that the water-based paint remover prepared by this invention is not only environmentally friendly but also has high paint removal efficiency. Specifically, considering the paint removal time and the continued paint removal time after 10 uses, compared to Comparative Examples 1 and 2, Examples 1-5 of this invention all exhibit stable paint removal efficiency, meaning the paint removal time remains within 5 minutes, and the paint removal effect is almost unaffected. It also has good settling properties and the cleanliness of the test panel surface. Example 4, in particular, showed excellent results in all tests, meeting the requirement of removing the paint film from the test panel surface within 3 minutes. Figure 1The image shows the paint removal effect of a test panel with a 110 μm thick polyester powder coating after immersion in the paint remover of Example 4 provided by this invention for 2.5 minutes. The surface of the test panel after paint removal is clearly clean and smooth. It also exhibits good settling properties, with a paint residue settling rate of up to 65%. In Example 6, only a surfactant was added; the settling agent polyacrylamide was not added, and other raw materials were the same as in Examples 1-5. Figure 2 As shown, the surface of the test panel after paint stripping was clean and smooth, but the paint residue settling rate was only 8%. That is, the settling properties of the paint stripper in Example 6 did not meet the requirements. In Example 7, only the settling agent polyacrylamide was added; no surfactant was added, and the other raw materials were the same as in Examples 1-5. Figure 3 As shown, after paint stripping, the surface cleanliness of the test panel was unsatisfactory, with visible spots, yet the paint residue settling rate was as high as 65%. This indicates that the paint stripper in Example 7 did not contain the surfactant selected in this invention, and its paint stripping effect did not meet the requirements. Finally, comparing Examples 1 and 2, neither contained the surfactant or settling agent selected in this invention; the other raw materials were commonly used in the prior art. Figure 4 As shown in Table 2, the surface cleanliness of the test panel in Comparative Example 1 was not ideal. Upon close inspection, it showed cloud-like residue and was not clean and smooth. However, the paint sludge settling rate was poor, only 8%. This means that the paint sludge settling effect of the paint remover in Comparative Example 1 did not meet the requirements. As shown in Table 2, the surface of the test panel in Comparative Example 2 was relatively clean and smooth. Similarly, the paint sludge settling rate was poor, only 6%. This means that the paint sludge settling effect of the paint remover in Comparative Example 2 did not meet the requirements.

[0115] As can be seen from the comparative examples 1 and 2, which are surface-treated with paint removers prepared by existing technologies, the lack of the surfactant and flocculant provided by this invention results in ineffective settling of paint sludge, cloudy paint remover, and a significant reduction in paint removal efficiency after 10 paint removal cycles. In contrast, Examples 1-5 show almost no impact on paint removal efficiency. Table 2 shows that the surfactant specifically defined in this invention improves the compatibility of the various components of the paint remover, effectively reducing the adhesion between the paint film and the substrate, and increasing paint removal efficiency. It also helps improve the storage stability of the paint remover, facilitating subsequent water rinsing for paint removal. The specific selection of polyacrylamide and its derivatives as flocculants, besides facilitating the cleaning of paint sludge and maintaining the effective use time of the paint remover, ensures good compatibility between the flocculant and the surfactant, guaranteeing optimal solubility of each raw material in the solvent. This means that the adhesion between the paint film and the substrate and the paint removal efficiency are not reduced, resulting in unexpected technical effects. The test results of Examples 6 and 7 show that simply adding surfactants or simply adding settling agents cannot simultaneously achieve a clean and smooth surface on the test panel after paint stripping and a paint sludge settling rate that meets the requirements.

[0116] The paint remover provided by this invention employs a complete system composed of multiple raw materials, enabling mutual synergy and improvement in compatibility. The use of a well-matched flocculant and surfactant ensures high paint removal efficiency while facilitating rapid aggregation and settling of paint residue for timely removal. This extends the effective service life of the paint remover, maintains stability, and meets the requirements of automated production lines for continuous and stable paint removal from workpiece surfaces. The introduction of a specific flocculant in this invention has not resulted in a reduction in the adhesion between the paint film and the substrate or in paint removal efficiency, thus benefiting automated paint removal production.

[0117] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water-based paint remover, characterized in that, It is formulated from the following ingredients in the following weight percentages: Main solvent 50.0~60.0%, cosolvent 10.0~40.0%, thickener 1.0~2.0%. Surfactant 1.0~3.0%, flocculant 0.5-1.0%, accelerator 3.0~4.0%; The main solvent is one or two of benzyl alcohol, benzaldehyde, N-methyl-2-pyrrolidone, benzoic acid, or isohexanediol; The co-solvent is at least one of 2-methyl-2,4-pentanediol, ethanolamine, propylene glycol, or water; The surfactant is one or two of sodium polymethacrylate, nonylphenol polyoxyethylene ether, polystyrene sulfonic acid, or 3-hydroxypropanesulfonic acid. The settling agent is polyacrylamide and its derivatives; The accelerator is a compound of potassium hydroxide and ester-based quaternary ammonium salt.

2. The water-based paint remover as described in claim 1, characterized in that, The thickener is polyvinyl alcohol and / or polyethylene glycol.

3. A method for preparing the water-based paint remover as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Slowly add the main solvent and the co-solvent to the beaker, and stir for a set time to obtain a mixture; Step 2: Slowly add the surfactant to the primary mixture and mix thoroughly to obtain the secondary mixture; Step 3: Add the thickener and settling agent to the secondary mixture, and stir at the set speed for the set time to obtain the tertiary mixture; Step 4: Heat the three-component mixture to a set temperature, then add the accelerator, and mix thoroughly with ultrasound for a set time to obtain the water-based paint remover.

4. The preparation method according to claim 3, characterized in that, In step 1, the stirring time is 30-40 minutes.

5. The preparation method according to claim 3, characterized in that, In step 3, the mixture is stirred at a speed of 100-120 r / min for 25-35 minutes.

6. The preparation method according to claim 3, characterized in that, In step 4, the three mixtures are heated to 60-65°C and mixed using ultrasound for 15-25 minutes.

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