Environment-friendly water-based paint remover for tooling as well as preparation method and application of paint remover

Abstract

The invention relates to the technical field of paint removers, and particularly discloses an environment-friendly water-based paint remover for tools as well as a preparation method and application of the environment-friendly water-based paint remover. The invention provides an environment-friendly water-based paint remover for tools. The environment-friendly water-based paint remover is specifically prepared from 280-320 parts of a main solvent, 40-54 parts of a solubilizer, 30-40 parts of a surfactant, 7-13 parts of a penetrating agent, 130-150 parts of monoethanolamine, 8-12 parts of sulfonic acid, 40-58 parts of caustic soda flakes, 1-5 parts of a thickening agent and 280-320 parts of water. The main solvent is formed by mixing benzyl alcohol and dipropylene glycol monomethyl ether according to the weight ratio of (0.1-1): (1-10); the preparation method of the penetrant comprises the following steps: reacting phthalic anhydride, ethylene glycol and hydroquinone to obtain modified polyester; and then mixing the modified polyester with isooctanol polyoxyethylene ether JFC-3 to obtain the modified polyester. The paint remover prepared by the invention has good paint removal efficiency, and can effectively improve the production efficiency of an automobile coating factory and reduce the comprehensive cost.

Description

Technical Field

[0001] This application relates to the technical field of paint strippers, and specifically relates to an environmentally friendly waterborne paint stripper for tooling and its preparation method and application. Background Art

[0002] With the development of the automotive industry and the improvement of people's living standards, people's demand for purchasing cars is increasing, especially with the popularization of new energy vehicles, the sales volume of cars continues to grow. Correspondingly, the production pressure of automobile factories is relatively large and the rhythm is relatively fast, which requires high efficiency in each production link. As a key link in the production line, improving the efficiency of painting is crucial. Through research, it is found that most of the paint strippers used for tooling fixtures in the painting process of automobile factories are still traditional organic solvent-based, containing toxic and harmful solvents such as halogenated hydrocarbons, phenol, ethyl acetate, and acetone. Not only is the paint stripping efficiency low (usually 6 - 8 hours, and the paint stripping time is even longer in winter), but it also causes great harm to operators and the environment. Therefore, environmentally friendly waterborne paint strippers are an inevitable trend in the development of the field of paint stripping for automobile tooling fixtures.

[0003] To solve these problems, developing a more environmentally friendly paint stripper formula to reduce harm to the environment and human body; improving the paint stripping efficiency and shortening the treatment time are expected to bring a revolutionary change to the paint stripping industry. Summary of the Invention

[0004] To solve the above technical problems, this application provides an environmentally friendly waterborne paint stripper for tooling and its preparation method and application.

[0005] In the first aspect, this application provides an environmentally friendly waterborne paint stripper for tooling, which specifically includes the following components in parts by weight: 280 - 320 parts of main solvent, 40 - 54 parts of solubilizer, 30 - 40 parts of surfactant, 7 - 13 parts of penetrant, 130 - 150 parts of monoethanolamine, 8 - 12 parts of sulfonic acid, 40 - 58 parts of caustic soda, 1 - 5 parts of thickener, and 280 - 320 parts of water; The main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.1 - 1:1 - 10; The preparation method of the penetrant is as follows: phthalic anhydride, ethylene glycol, and hydroquinone are mixed evenly according to a molar ratio of 1.2 - 1.8:1:0.04 - 0.08, and heated to 70 - 90°C. Then, 0.02 - 0.04 wt% of catalyst is added to the reaction system, and nitrogen is introduced while raising the temperature to 105 - 115°C for reaction for 8 - 14 hours. After the reaction, it is cooled to room temperature to obtain modified polyester; then the modified polyester and isooctyl alcohol polyoxyethylene ether JFC - 3 are mixed according to a weight ratio of 0.5 - 1.5:3 - 10 to obtain the penetrant.

[0006] The environmentally friendly water-based paint stripper for tooling proposed in this application is a water-based system, does not contain toxic and harmful solvents such as dichloromethane and chloroform, is easy to transport and store, has a short paint stripping time, and has excellent application prospects in the field of paint stripping for automotive tooling fixtures.

[0007] In the paint stripper formula provided by the present application, benzyl alcohol can quickly penetrate into the paint layer during the paint stripping process, soften the paint film, reduce the adhesion between the paint layer and the substrate, and make the paint layer easier to be stripped, thereby improving the paint stripping efficiency; benzyl alcohol also has good stability and compatibility, and can work in conjunction with other paint stripper ingredients to enhance the overall paint stripping effect. Dipropylene glycol methyl ether has a lower boiling point and a faster volatilization rate. During the paint stripping process, it can quickly take away the heat on the surface of the paint layer, reduce the temperature of the paint layer, and thus accelerate the stripping of the paint layer.

[0008] In addition, during the experiment, the applicant found that phthalic anhydride, ethylene glycol, hydroquinone and catalyst can be used to generate a modified polyester / aromatic ester structure through chemical reaction. This substance can interact with polar groups (such as hydroxyl and carboxyl) in the paint film to destroy the hydrogen bond network inside the paint film; and the aromatic ring structure has similar compatibility with paint films containing benzene rings (such as alkyd resins and phenolic paints), promoting penetration; at the same time, it can slowly diffuse into the paint film, increase the free volume of the paint film, and make the paint film swell and soften, which is convenient for subsequent peeling; when compounded with other ingredients such as the main solvent in the paint stripper, the solvent residence time can be extended to prevent excessive volatilization and improve the paint stripping efficiency. The applicant uses this modified polyester combined with isooctyl alcohol polyoxyethylene ether JFC-3, which is suitable for the paint stripper system of this application, which can quickly penetrate the paint coating, easily pass through the tiny gaps in the paint coating, destroy the chemical bonds inside the coating, and make it lose adhesion, thereby achieving the purpose of paint stripping.

[0009] Surfactants such as AES fatty alcohol polyoxyethylene ether sulfate can reduce the surface tension of the paint stripper and accelerate the stripping of the paint layer. Monoethanolamine, as a regulator, can adjust the pH value of the paint stripper to ensure that it works at the most suitable pH, and also helps to stabilize the paint stripping process. Sulfonic acid, as a catalyst, accelerates the paint stripping reaction and improves the paint stripping efficiency. Caustic soda (sodium hydroxide) is a strong alkaline agent used to decompose certain chemical components in the paint and promote the stripping of the paint layer. The main function of the thickener is to adjust the rheological properties of the paint stripper, making it easier to apply, reduce volatility, and enhance adhesion, so that the paint stripper can act on the paint film surface for a longer time and improve the paint stripping efficiency.

[0010] Preferably, the environmentally friendly water-based paint stripper for tooling specifically includes the following components in parts by weight: 290-310 parts of a main solvent, 44-50 parts of a solubilizer, 32-38 parts of a surfactant, 9-11 parts of a penetrant, 135-145 parts of monoethanolamine, 9-11 parts of sulfonic acid, 44-54 parts of caustic soda, 2-4 parts of a thickener, and 290-310 parts of water.

[0011] Preferably, the main solvent is composed of a mixture of benzyl alcohol and dipropylene glycol methyl ether with a weight ratio of 0.3 - 0.7:3 - 8.

[0012] In a specific embodiment, in the main solvent, the weight ratio of benzyl alcohol to dipropylene glycol methyl ether can be 0.1:1, 0.3:1, 0.5:1, 0.7:1, 1:1, 0.1:3, 0.5:3, 0.7:3, 1:3, 0.1:5, 0.3:5, 0.7:5, 1:5, 0.1:8, 0.3:8, 0.5:8, 0.7:8, 1:8, 0.1:10, 0.3:10, 0.5:10, 0.7:10, 1:10.

[0013] Through experimental analysis, it can be known that by using the main solvent composed of the above - mentioned weight ratio of benzyl alcohol and dipropylene glycol methyl ether in this application, the application effect of the paint remover can be effectively improved.

[0014] Preferably, in the preparation method of the penetrant, the catalyst is selected from one or more of p - toluenesulfonic acid, methanesulfonic acid, and 4 - dimethylaminopyridine.

[0015] Preferably, in the preparation method of the penetrant, the weight ratio of the modified polyester to isooctyl alcohol polyoxyethylene ether JFC - 3 is 0.7 - 1.2:5 - 7.

[0016] Preferably, the solubilizer is selected from one or more of ethylene glycol phenyl ether, sodium xylene sulfonate, sodium p - toluenesulfonate, and sodium isopropylbenzene sulfonate.

[0017] Preferably, the surfactant is selected from one or more of AES fatty alcohol polyoxyethylene ether sulfate, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, and fatty alcohol polyoxyethylene ether - 9EO.

[0018] Preferably, the thickener is selected from one or more of G1701 oil - based thickener, fumed silica thickener, white dextrin powder, and hydroxyethyl cellulose.

[0019] In the second aspect, this application provides a preparation method of the environment - friendly tooling water - based paint remover, which specifically includes the following steps in sequence: Weigh the corresponding raw material components respectively; Put one - half to two - thirds of the amount of water into the reaction kettle, start stirring, add the main solvent and caustic soda, and stir until completely dissolved; then add the solubilizer, surfactant, and penetrant, and continue stirring until completely dissolved; then add monoethanolamine, and continue stirring and mixing evenly; finally, add the thickener, and stir and mix evenly; Make up the remaining water, and continue stirring until uniform, then it is obtained.

[0020] Thirdly, the present application provides the application of the above-mentioned environment-friendly tooling water-based paint stripper in the paint stripping of automobile tooling fixtures.

[0021] In summary, the technical solution of the present application has the following effects: The paint stripper formula provided by the present application does not contain toxic and harmful solvents such as dichloromethane and chloroform, is convenient for transportation and storage, has a short paint stripping time, and has excellent application prospects in the field of paint stripping of automobile tooling fixtures.

[0022] The preparation method of the paint stripper provided by the present application has a simple production process. The water-based paint stripper does not contain phenolic and chlorinated alkane solvents, is non-toxic and harmless to operators and the environment, has a high paint stripping efficiency, can be recycled, can improve the production efficiency of automobile painting plants, and reduces the comprehensive cost. Specific Embodiments

[0023] The present application will be further described in detail below in conjunction with examples, comparative examples, and performance detection tests. These examples should not be construed as limiting the scope claimed by the present application. Examples Examples 1-5

[0024] Examples 1-5 respectively provide an environment-friendly tooling water-based paint stripper.

[0025] The differences between the above examples are as follows: the dosages of each component in the environment-friendly tooling water-based paint stripper are different, as shown in Table 1 specifically. The preparation method of the environment-friendly tooling water-based paint stripper in the above examples is as follows.

[0026] The preparation method of the penetrant is as follows: phthalic anhydride, ethylene glycol, and hydroquinone are mixed evenly according to a molar ratio of 1.5 mol: 1 mol: 0.06 mol, and heated to 80 °C. Then, 0.03 wt% of a catalyst is added to the reaction system, and nitrogen is introduced while raising the temperature to 110 °C. The reaction is carried out for 12 h. After the reaction is completed, it is cooled to room temperature to obtain a modified polyester. Then, the modified polyester and isooctyl alcohol polyoxyethylene ether JFC-3 are mixed according to a weight ratio of 1:6 to obtain the penetrant.

[0027] According to Table 1, the corresponding weights of each raw material component are weighed respectively; half of the amount of water is put into the reaction kettle, the stirring is started, the main solvent (composed of benzyl alcohol and dipropylene glycol methyl ether with a weight ratio of 0.5:6), and caustic soda are added, and stirred until completely dissolved; then the solubilizer ethylene glycol phenyl ether, the surfactant AES fatty alcohol polyoxyethylene ether sulfate, and the penetrant are added, and stirred until completely dissolved; then monoethanolamine is added, and stirred and mixed evenly; finally, sulfonic acid and the thickener Degussa A300 fumed silica are added, and stirred and mixed evenly; the remaining water is supplemented, and stirred until uniform to obtain the product.

[0028] Table 1 Dosages of Components in the Environmentally Friendly Tooling Waterborne Paint Stripper in Examples 1-5 Examples 6-9

[0029] Examples 6-9 respectively provide an environmentally friendly tooling waterborne paint stripper.

[0030] The differences between the above examples and Example 3 are specifically as follows: the main solvents are different, as shown below.

[0031] In Example 6: the main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.1:10.

[0032] In Example 7: the main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.3:8.

[0033] In Example 8: the main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.7:3.

[0034] In Example 9: the main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 1:1.

[0035] Other process parameters in the above examples are the same as those in Example 3. Examples 10-13

[0036] Examples 10-13 respectively provide an environmentally friendly tooling waterborne paint stripper.

[0037] The differences between the above examples and Example 3 are specifically as follows: the preparation methods of the penetrants are different, as shown below.

[0038] In Example 10: in the penetrant, the weight ratio of the modified polyester to the isooctyl alcohol polyoxyethylene ether JFC-3 is 0.5:10.

[0039] In Example 11: in the penetrant, the weight ratio of the modified polyester to the isooctyl alcohol polyoxyethylene ether JFC-3 is 0.7:7.

[0040] In Example 12: in the penetrant, the weight ratio of the modified polyester to the isooctyl alcohol polyoxyethylene ether JFC-3 is 1.2:5.

[0041] In Example 13: in the penetrant, the weight ratio of the modified polyester to the isooctyl alcohol polyoxyethylene ether JFC-3 is 1.5:3.

[0042] Other process parameters in the above examples are the same as those in Example 3. Examples 14-15

[0043] Examples 14-15 respectively provide an environmentally friendly tooling waterborne paint stripper.

[0044] The differences between the above-mentioned embodiments and Embodiment 3 are specifically as follows.

[0045] In Embodiment 14: The solubilizer is sodium p-toluenesulfonate.

[0046] In Embodiment 15: The surfactant is sodium dodecyl sulfate.

[0047] Other process parameters in the above-mentioned embodiments are the same as those in Embodiment 3. Comparative Example Comparative Examples 1-2

[0048] Comparative Examples 1-2 respectively provide an environmentally friendly water-based paint stripper for tooling.

[0049] The differences between the above-mentioned comparative examples and Embodiment 3 are as follows: The dosages of each component in the environmentally friendly water-based paint stripper for tooling are different, as shown in Table 1 specifically.

[0050] Other process parameters in the above-mentioned comparative examples are the same as those in Embodiment 3. Comparative Examples 3-6

[0051] Comparative Examples 3-6 respectively provide an environmentally friendly water-based paint stripper for tooling.

[0052] The differences between the above-mentioned comparative examples and Embodiment 3 are specifically as follows.

[0053] In Comparative Example 3: The main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.5:6.

[0054] In Comparative Example 4: The main solvent is composed of benzyl alcohol and propylene glycol ethyl ether mixed in a weight ratio of 6:0.5.

[0055] In Comparative Example 5: The penetrant is isooctyl polyoxyethylene ether JFC-3.

[0056] In Comparative Example 6: In the penetrant, the weight ratio of the modified polyester to isooctyl polyoxyethylene ether JFC-3 is 5:1.2.

[0057] Other process parameters in the above-mentioned comparative examples are the same as those in Embodiment 3. Performance Detection Test

[0058] (1) Paint Stripping Performance Coat a paint film on a steel plate (50 mm × 100 mm) with gray epoxy zinc-rich primer according to the provisions of GB / T1727-1992 to obtain a specimen workpiece; then immerse the specimen workpiece in the paint strippers prepared in the embodiments and comparative examples, and conduct a paint stripping experiment under the water bath conditions of 25°C and 50°C. Each group of tests is repeated 3 times, and the average value is taken and recorded as the paint stripping time.

[0059] (2)Automobile Tooling Fixture Paint Stripping Performance Detection Soak Specimen 1 - fixture with polyurethane resin paint (rear isolator, provided by BYD Changzhou), Specimen 2 - fixture with acrylic resin paint (front isolator, provided by BYD Jinan), Specimen 3 - fixture with epoxy resin paint (electrophoretic paint) (rear isolator, provided by BYD Hefei), and Specimen 4 - fixture with cured 2K clear coat (rear isolator, provided by BYD Xi'an) in the paint stripper, heat to 50 °C, observe the paint stripping process, and record the paint stripping time.

[0060] Test Results: As shown in Table 2.

[0061] Table 2 Performance Test Results of Paint Strippers in Examples and Comparative Examples

[0062] Combined with the test results in the above table, it can be seen that using the technical solution provided by this application, the prepared paint stripper has good paint stripping efficiency, and this paint stripper can be used for paint stripping of various tools in automobile painting factories, thereby effectively improving the production efficiency of automobile painting factories and reducing the comprehensive cost.

[0063] By comparing the test results in Examples 1 - 5 and Comparative Examples 1 - 2, it can be seen that the dosages of each raw material component have a great influence on the use effect of the paint stripper. The dosages of each raw material component in Comparative Examples 1 - 2 do not match, and the application effect of the paint stripper is poor. In contrast, by controlling and matching the dosages of each raw material component in the examples of this application, the application effect of the paint stripper is effectively improved.

[0064] By comparing the test results in Examples 3, 6 - 9 and Comparative Examples 3 - 4, it can be seen that in Comparative Example 3, the main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.5:6, and in Comparative Example 4, the main solvent is composed of benzyl alcohol and propylene glycol ethyl ether mixed in a weight ratio of 6:0.5, and the application effect of the paint stripper is poor. In contrast, in the examples of this application, by using a main solvent composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.1 - 1:1 - 10, the application effect of the paint stripper is effectively improved.

[0065] By comparing the test results in Examples 3, 10 - 13 and Comparative Examples 3 - 4, it can be seen that in Comparative Example 5, the penetrant is isooctyl alcohol polyoxyethylene ether JFC - 3, and in Comparative Example 6, the weight ratio of modified polyester to isooctyl alcohol polyoxyethylene ether JFC - 3 in the penetrant is 5:1.2, and the effect of the prepared paint stripper is poor. In contrast, in the examples of this application, by using a main solvent composed of modified polyester and isooctyl alcohol polyoxyethylene ether JFC - 3 mixed in a weight ratio of 0.5 - 1.5:3 - 10, the application effect of the paint stripper is effectively improved.

[0066] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it on the basis of the present invention, which will be obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. An environmentally friendly water-based paint stripper for work tools, characterized in that, Specifically, it includes the following components in parts by weight: 280 - 320 parts of main solvent, 40 - 54 parts of solubilizer, 30 - 40 parts of surfactant, 7 - 13 parts of penetrant, 130 - 150 parts of monoethanolamine, 8 - 12 parts of sulfonic acid, 40 - 58 parts of caustic soda, 1 - 5 parts of thickener, and 280 - 320 parts of water; The main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.1 - 1:1 - 10; The preparation method of the penetrant is as follows: Phthalic anhydride, ethylene glycol, and hydroquinone are mixed evenly according to a molar ratio of 1.2 - 1.8:1:0.04 - 0.08, and when heated to a temperature of 70 - 90 °C, a catalyst of 0.02 - 0.04 wt% is added to the reaction system, and at the same time, nitrogen is introduced, the temperature is raised to 105 - 115 °C, and the reaction is carried out for 8 - 14 h. After the reaction is completed, it is cooled to room temperature to obtain the modified polyester; then the modified polyester and isooctyl alcohol polyoxyethylene ether JFC - 3 are mixed according to a weight ratio of 0.5 - 1.5:3 - 10 to obtain the penetrant.

2. The environmentally friendly industrial waterborne paint stripper according to claim 1, characterized in that, Specifically, it includes the following components in parts by weight: 290 - 310 parts of main solvent, 44 - 50 parts of solubilizer, 32 - 38 parts of surfactant, 9 - 11 parts of penetrant, 135 - 145 parts of monoethanolamine, 9 - 11 parts of sulfonic acid, 44 - 54 parts of caustic soda, 2 - 4 parts of thickener, and 290 - 310 parts of water.

3. The environmentally friendly tooling water-based paint stripper according to claim 1, characterized in that, The main solvent is composed of benzyl alcohol and dipropylene glycol methyl ether mixed in a weight ratio of 0.3 - 0.7:3 - 8.

4. The environmentally friendly tooling waterborne paint stripper according to claim 1, characterized in that, In the preparation method of the penetrant, the catalyst is selected from one or more of p - toluenesulfonic acid, methylsulfonic acid, and 4 - dimethylaminopyridine.

5. The environmentally friendly tooling waterborne paint stripper according to claim 1, characterized in that, In the preparation method of the penetrant, the weight ratio of the modified polyester to isooctyl alcohol polyoxyethylene ether JFC - 3 is 0.7 - 1.2:5 - 7.

6. The environmentally friendly tooling water-based paint stripper according to claim 1, characterized in that, The solubilizer is selected from one or more of ethylene glycol phenyl ether, sodium xylene sulfonate, sodium p - toluenesulfonate, and sodium isopropylbenzene sulfonate.

7. The environmentally friendly tooling waterborne paint stripper according to claim 1, characterized in that, The surfactant is selected from one or more of AES fatty alcohol polyoxyethylene ether sulfate, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, and fatty alcohol polyoxyethylene ether - 9EO.

8. The environmentally friendly tooling waterborne paint stripper according to claim 1, characterized in that The thickener is selected from one or more of G1701 oil thickener, fumed silica thickener, white dextrin powder, and hydroxyethyl cellulose.

9. The preparation method of the environment-friendly tooling water-based paint stripper according to claim 1, characterized in that, Specifically, it includes the following steps in sequence: Weigh the corresponding raw material components respectively; Put half to two - thirds of the amount of water into the reaction kettle, start stirring, add the main solvent and caustic soda, and stir until completely dissolved; then add the solubilizer, surfactant, and penetrant, and continue to stir until completely dissolved; then add monoethanolamine, and continue to stir and mix evenly; finally, add sulfonic acid and thickener, and stir and mix evenly; Make up the remaining water, continue to stir until uniform, and that's it.

10. Application of the environmentally friendly industrial tool water - based paint stripper according to any one of claims 1 - 8 in the paint stripping of automotive industrial tool fixtures.

Images