Film-forming auxiliary agent, water-based catalytically degradable washable removable coating containing film-forming auxiliary agent and application of water-based catalytically degradable washable removable coating

Abstract

The invention discloses a coalescing agent and a water-based catalytically degradable washable removable coating containing the coalescing agent. According to the film-forming auxiliary agent, 2, 2, 4-trimethyl-1, 3-pentanediol di-n-butyrate is used as a core film-forming component and matched with a TACN Mn metal catalyst to construct a controllable degradation system, and meanwhile, the invention discloses a preparation process of the film-forming auxiliary agent, a matched coating formula, a construction process and a synergistic removal method of sodium percarbonate catalytic cracking and high-pressure water gun / warm water wiping. The device can be adapted to multiple scenes such as water-based billboards, special exhibition buildings, water-based nail polish and the like. The coating has high stability in a use stage and controllable degradability in a removal stage, the reuse rate of a base material in an industrial scene is larger than or equal to 98%, the content of VOCs in a manicure scene is low, dismounting is convenient, and environment-friendly controllability of the whole life cycle of the coating is achieved.

Description

Technical Field

[0001] This invention belongs to the field of multifunctional water-based coating materials technology, specifically relating to a film-forming aid formulation containing 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate and TACN Mn metal catalyst. It also discloses the preparation process of the film-forming aid, the matching water-based catalytically degradable and washable coating formulation containing the film-forming aid, the construction process, and the synergistic removal method of "chemical catalytic cracking + physical washing", which can be adapted to various scenarios such as industrial temporary coatings and civilian nail coatings. Background Technology

[0002] 2,2,4-Trimethyl-1,3-pentanediol di-n-butyrate, as a low-toxicity and environmentally friendly ester compound, is currently used in coating plasticizing and resin synthesis. However, there is no technology that combines it with a catalytic degradation system to achieve controlled removal of the coating. At the same time, existing patents in the UK, Japan, and the US either use physical water washing to remove the coating (which has the defect of incomplete removal) or use a single catalytic system to degrade the coating (which is prone to damaging the substrate). There is no technical solution that combines the film-forming toughness of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, the catalytic activity of TACN Mn, and the hydrolytic properties of sodium percarbonate to achieve a coating with "high stability during use and controllable degradation during removal".

[0003] Based on this, this application was developed. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art and provide a film-forming aid formulation containing 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate and TACN Mn metal catalyst, as well as a matching water-based catalytically degradable and washable coating formulation containing the film-forming aid. This solves the technical pain points of traditional water-based coatings, such as "the inability to balance toughness and removability", "low reusability of substrates in industrial scenarios", and "inconvenient removal in nail salon scenarios". At the same time, it avoids the technical overlap of existing patents at home and abroad and achieves environmental protection and controllability throughout the entire life cycle of the coating.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A film-forming aid, comprising, by mass parts: 15-25 parts of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, 30-40 parts of aqueous polyurethane dispersion, 5-8 parts of propylene glycol methyl ether acetate, 1-2 parts of polyether-modified silicone leveling agent, 0.02-0.05 parts of TACNMn metal catalyst, and 20-30 parts of deionized water; wherein the TACNMn metal catalyst is a triazacyclononane manganese(II) complex, and exists in a non-crosslinked dispersion state in the film-forming aid system.

[0006] As a preferred embodiment, the above-mentioned film-forming aid comprises, by weight parts, the following components: 20 parts of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, 35 parts of aqueous polyurethane dispersion, 6 parts of propylene glycol methyl ether acetate, 1.5 parts of polyether-modified silicone leveling agent, 0.03 parts of TACN Mn metal catalyst, and 27-28 parts of deionized water.

[0007] This invention provides a preparation process for the above-mentioned film-forming aid, which involves three steps: premixing a leveling agent, preparing a composite aid solution, and compounding and molding. Specifically, the process includes the following steps: 1) Premixed leveling agent: Mix deionized water with polyether modified silicone leveling agent and stir at a low speed of 300-400 r / min for 5-8 min to obtain a premixed solution; 2) Preparation of composite additive solution: Add 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate and propylene glycol methyl ether acetate to the premixed solution, heat to 40-45℃, stir at a medium speed of 500-600 r / min for 10-15 min, then add TACNMn metal catalyst and maintain the temperature at 40-45℃ while stirring for 3-5 min to obtain composite additive solution; 3) Compounding and molding: Add water-based polyurethane dispersion to the compound additive liquid, cool to 25-30℃, stir at a low speed of 200-300r / min for 20-25min, and filter through a 500-mesh filter to obtain the finished film-forming aid.

[0008] This invention provides an aqueous, catalytically degradable, washable coating containing the aforementioned film-forming aid, with formulations tailored to different application scenarios: its composition by weight... When applicable to billboard / exhibition special building scenarios, it includes the following components: 25-30 parts of the film-forming aid, 35-45 parts of water-based acrylic resin, 5-10 parts of water-based color paste, 0.5-1 part of water-based thickener, 15-25 parts of deionized water, 0.1-0.2 parts of preservative and antibacterial agent, and 1-2 parts of benzotriazole anti-UV additive; When applicable to water-based nail polish applications, the following components are included: 20-25 parts of the film-forming aid, 35-45 parts of water-based acrylic resin, 5-10 parts of water-based pigment, 0.5-1 part of water-based thickener, 10-17 parts of deionized water, and 0.1-0.2 parts of phenoxyethanol low-irritant antibacterial agent.

[0009] Furthermore, the water-based color paste can be at least one of titanium dioxide water-based color paste, phthalocyanine blue water-based color paste, CI Acid Red 52 water-based color paste, etc. The water-based thickener can be at least one of polyether modified polyurethane thickener (such as BYK-425), polyacrylate alkali-swelling thickener, hydroxyethyl cellulose, etc.

[0010] Furthermore, the preservative and antibacterial agent can be at least one of CMIT / MIT compound, 1,2-benzisothiazolin-3-one, phenoxyethanol, etc. The CMIT / MIT compound is a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2-methyl-4-isothiazolin-3-one (MIT). The benzotriazole UV-resistant additive can specifically be at least one of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P), 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole (UV-320), etc. In this invention, all the above-mentioned raw materials are suitable for aqueous systems and meet the environmental and functional requirements of the corresponding scenarios.

[0011] The present invention also provides a construction process for the above-mentioned water-based catalytically degradable and water-washable removable coating, which includes the following steps: (1) Substrate pretreatment: Dust removal and oil removal of billboard boards / exhibition special decoration substrates and drying to surface moisture content ≤1%; degreasing and cleaning of nail surfaces and removal of surface cuticle layer; (2) Coating preparation: Mix the film-forming aid with the remaining components of the coating evenly, let it stand to defoam for 10-15 minutes, and add water to control the viscosity of the system to 1500-2500 mPa·s; (3) Coating application: The substrate of the billboard / exhibition special exhibition is coated by roller or spray, with a single coating thickness of 30-50μm. After 30-40 minutes of surface drying at room temperature, the coating is repeated 1-2 times; the nail polish is applied by brush, with a single brush coating thickness of 5-10μm. After 5-8 minutes of surface drying, the top coat is applied. (4) Curing and molding: The coatings for all scenarios are cured for 2-4 hours at 25-30℃ and 50%-60% humidity. After curing, the coating surface is free of pinholes and sagging defects.

[0012] This invention also provides a method for removing the above-mentioned water-based, catalytically degradable, and washable coating, which adopts a synergistic approach of "catalytic decomposition + physical stripping" according to the application scenario. The specific operation is as follows: (1) Billboard / Exhibition special building scene: First, spray or brush a sodium percarbonate aqueous solution with a mass concentration of 5%-8% evenly on the coating surface, let it stand for 10-15 minutes, and use the hydrogen peroxide generated by the hydrolysis of sodium percarbonate to catalyze the cracking of the ester bond inside the coating under the action of TACN Mn metal catalyst. Then, use a high pressure water gun with a pressure of 0.8-1.2MPa to rinse at a 45° angle for 1-3 minutes to achieve complete peeling of the coating without damage to the substrate; (2) Water-based nail polish scenario: Soak the nails in a warm sodium percarbonate solution at a temperature of 35-40℃ and a mass concentration of 3%-5% for 2-3 minutes (at this time the coating will swell and turn white). It can be completely removed by gently wiping with a cotton pad, leaving no residue and not irritating the nail surface.

[0013] This invention provides the application of the above-mentioned water-based catalytically degradable and water-washable coating in billboard / exhibition special building scenarios or water-based nail polish scenarios.

[0014] This invention provides the application of the above-mentioned film-forming aid in the preparation of water-based replaceable coatings for billboards, temporary coatings for special exhibition buildings, or low-irritation water-based nail polish, etc.; wherein, the coating in industrial scenarios has a weather resistance of ≥6 months, a friction resistance of ≥620 times, and a substrate reuse rate of ≥98% after catalytic stripping; the coating in nail art scenarios has a film-forming time of ≤12min, a scratch resistance of ≥38 times, and a VOCs content of ≤22g / L, which meets the relevant standards for cosmetic safety.

[0015] The core and innovation of this invention lies in constructing a synergistic system of "2,2,4-trimethyl-1,3-pentanediol di-n-butyrate film-forming toughening + TACN Mn catalytic degradation + sodium percarbonate hydrolysis for energy supply": 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate serves as the core film-forming aid, ensuring the toughness and adhesion of the coating during use; dispersed TACN Mn metal catalyst acts as the core degradation trigger, without affecting the stability of the coating after curing; and sodium percarbonate aqueous solution serves as the degradation trigger, where the hydrogen peroxide generated by its hydrolysis directionally cleaves the ester bonds and polyurethane soft segments within the coating under the catalysis of TACN Mn, combined with physical washing to achieve non-destructive peeling of the coating. The coating formulation of this invention can be adjusted according to industrial and civilian applications. During construction, the moisture content of the substrate and the viscosity of the coating must be controlled, and removal employs a synergistic approach of "chemical catalysis + physical washing".

[0016] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1) Outstanding technological innovation: For the first time, the film-forming properties of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate are combined with the catalytic degradation properties of TACN Mn, and at the same time, a sodium percarbonate hydrolysis system is used to avoid the technical limitations of single physical peeling or single chemical degradation in British, Japanese and American patents. 2) Balancing performance and removability: The coating exhibits excellent toughness, weather resistance, and decorative properties during application. During removal, it can be peeled off non-destructively through catalytic pyrolysis. In industrial applications, the coating has a weather resistance of ≥6 months, a friction resistance of ≥620 cycles, and a substrate reuse rate of ≥98% after catalytic peeling. In nail salon applications, the removal efficiency is improved by more than 50%. 3) High environmental protection and safety: No chemical reagent residue in industrial settings; for nail art settings, the coating film forming time is ≤12min, the scratch resistance is ≥38 times and the VOCs content is ≤22g / L; the remover is a low-concentration sodium percarbonate solution, which is non-irritating and meets environmental protection and safety standards in multiple fields, including cosmetic safety standards. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0018] In this invention, all raw materials used are commercially available products that can be purchased directly, or can be prepared using conventional techniques in the field. For example, 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate can be prepared by referring to the method in existing published literature (Wu Xueyun, Preparation process of film-forming aid 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, 2025, Issue 14, China New Technologies & New Products), or can be purchased as commercially available products.

[0019] In the following examples, the 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate used was commercially available product 295 purchased from Hongye Holdings Group Co., Ltd.; the polyether-modified silicone leveling agent was a commercially available product purchased from Dow Corning, product model DC-57, which can effectively improve the leveling properties of the coating and avoid pinholes and sagging defects.

[0020] The TACN Mn metal catalyst is a commercially available product purchased from Sigma-Aldrich, product model 68411-33-6, chemical name triazacyclononane manganese(II) complex, purity ≥97%, appearance is brown powder, good dispersibility in aqueous system, and high catalytic activity.

[0021] The waterborne polyurethane dispersion is a polyurethane resin product purchased from Dongguan Hongsui Industrial Investment Co., Ltd., product model T124.

[0022] The water-based acrylic resin used is YWA2200 from Qingyuan Yake Chemical Co., Ltd.

[0023] The top coat is mainly composed of a water-based polyurethane dispersion as the base material, combined with leveling agents, gloss enhancers, hardening agents, and HEUR-type thickeners. The examples below use commercially available products, specifically water-based nail polish top coats purchased from Wanhua Chemical.

[0024] Example 1: Preparation of film-forming aid A film-forming aid, comprising, by weight parts: 20 parts of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, 35 parts of aqueous polyurethane dispersion, 6 parts of propylene glycol methyl ether acetate, 1.5 parts of polyether-modified silicone leveling agent, 0.03 parts of TACN Mn metal catalyst, and 27.47 parts of deionized water.

[0025] The preparation process of the above-mentioned film-forming aid specifically includes the following steps: 1) Mix deionized water with polyether-modified silicone leveling agent and stir at a low speed of 350 r / min for 6 min to obtain a premixed solution; 2) Add 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate and propylene glycol methyl ether acetate to the premixed solution, heat to 42°C, stir at a medium speed of 550 r / min for 12 min, then add TACNMn metal catalyst and maintain the temperature at 42°C for 4 min to obtain composite additive solution; 3) Add water-based polyurethane dispersion to the composite additive solution, cool to 28℃, stir at a low speed of 250r / min for 22min, and filter through a 500-mesh filter to obtain the finished film-forming aid.

[0026] The performance test data of the film-forming aid prepared in this embodiment are as follows: The appearance is a uniform, transparent liquid without precipitation or stratification. The viscosity (25℃) is 800 mPa·s. Storage stability: No significant change was observed after 30 days at 50℃. Dispersion uniformity of the TACN Mn metal catalyst: Transmission electron microscopy revealed that the catalyst particles were 50-100 nm in size, exhibiting a uniform dispersion without agglomeration.

[0027] Example 2: Preparation and Removal of Billboard Coating A billboard coating formulation, comprising the following components by weight: Example 1: 28 parts film-forming aid, 40 parts water-based acrylic resin, 8 parts water-based color paste, 0.8 parts water-based thickener, 20 parts deionized water, 0.15 parts preservative and antibacterial agent, and 1.5 parts benzotriazole UV-resistant additive.

[0028] The water-based color paste is titanium dioxide water-based color paste; the water-based thickener is polyether modified polyurethane thickener BYK-425; the preservative and antibacterial agent is 1,2-benzisothiazolin-3-one and phenoxyethanol (mass ratio 1:1); the benzotriazole anti-UV additive is 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P).

[0029] The specific construction process for the above-mentioned billboard coating is as follows: 1) Remove dust and oil from the billboard panels and dry them until the surface moisture content is 0.8% (dust and oil removal can be done using conventional techniques in this field, and since this is not the innovation of this application, it will not be described in detail here). 2) Mix all components of the coating evenly, let stand at room temperature for 12 minutes to defoam, and add water to control the viscosity of the system to 2000 mPa·s; 3) Apply a single coat of 40μm using a spraying method. Allow it to dry at room temperature for 35 minutes, then repeat the spraying once. Finally, cure the coating at 28℃ and 55% humidity for 3 hours to obtain the final product.

[0030] The relevant performance indicators of the coating prepared in this embodiment are shown in Table 1 below. As can be seen from Table 1, the coating surface is smooth and free of pinholes and sagging defects; the adhesion is grade 1; the weather resistance is good, with no chalking or discoloration after 26 months; the abrasion resistance is 620 cycles (weight loss ≤ 5 mg); and the VOCs content is low (25 g / L).

[0031] Table 1. Relevant performance indicators of the coating prepared in Example 2 The removal process and experimental data of the coating prepared in this embodiment are as follows: First, a 6% sodium percarbonate aqueous solution was sprayed onto the coating surface and left to stand for 12 minutes. During this period, the coating status was monitored in real time: the coating began to soften after 3 minutes of immersion, the ester bond breakage rate reached 75% after 8 minutes of immersion (the intensity change of the characteristic peak of ester carbonyl was detected by infrared spectroscopy), and the ester bond breakage rate reached 98% after 12 minutes of immersion. Then, a 1.0 MPa high-pressure water gun was used to rinse the coating at a 45° angle for 2 minutes, and the coating was completely peeled off with a peeling rate of 100%.

[0032] Substrate surface roughness (Ra) test: 0.8μm before treatment, 0.82μm after treatment, no obvious change, can be directly reused.

[0033] The substrate reuse rate is 98% (after 5 coating and removal cycles of 100 substrates, 98 substrates are undamaged and can be used normally).

[0034] Example 3: Preparation and Removal of Water-Based Nail Polish A water-based nail polish formulation, comprising the following components by weight: Example 1: 22 parts film-forming aid, 38 parts water-based acrylic resin, 7 parts water-based color paste, 0.6 parts water-based thickener, 15 parts deionized water, and 0.1 parts phenoxyethanol.

[0035] The water-based colorant used is cosmetic-grade CI Acid Red 52 water-based colorant, and the water-based thickener is polyether-modified polyurethane thickener BYK-425.

[0036] The specific application process for the above-mentioned water-based nail polish is as follows: 1) Degrease and clean the nail surface and remove the surface cuticle (this step can be done using conventional techniques in the field, and since it is not an innovation of this application, it will not be described in detail here). 2) Mix all components of the coating evenly, let stand at room temperature for 10 minutes to defoam, and add water to control the viscosity of the system to 1800 mPa·s; 3) Apply the nail polish by brushing, with a single brush coat thickness of 8μm. Allow it to dry to room temperature for 6 minutes, then apply a top coat and cure at 25℃ and 50% humidity for 2 hours.

[0037] The relevant performance indicators of the coating prepared in this embodiment are shown in Table 2 below. As can be seen from Table 2, the coating has a fast film formation time, good scratch resistance (no obvious scratches after 38 scratches), excellent gloss (60°, 85), and low VOC content (22g / L).

[0038] Table 2. Relevant performance indicators of the coating prepared in Example 3 The removal process and experimental data of the coating prepared in this embodiment are as follows: Soak the nail in a 4% sodium percarbonate solution (38°C) for 3 minutes. The coating begins to swell and turn white after 1 minute of soaking. The swelling rate reaches 80% after 2 minutes of soaking. The coating is completely swollen after 3 minutes of soaking. The coating is completely removed within 30 seconds by gently wiping with a cotton pad, with a removal rate of 100%.

[0039] Surface residue detection: High performance liquid chromatography was used for detection, and no coating residue components were detected.

[0040] Nail skin irritation: After removal, there was no redness or stinging on the nail surface, with an irritation score of 0.2, which meets the safety standards for cosmetics.

[0041] Comparative example (TACN-free Mn and sodium percarbonate synergistic system) Referring to the above embodiments, a film-forming aid and a corresponding coating that do not contain TACN Mn metal catalyst were prepared.

[0042] The test results showed that after spraying the coating with water and letting it stand, simply rinsing the billboard coating with a high-pressure water gun could only peel off 30% of the surface coating, leaving a large amount of coating residue on the substrate that was difficult to clean; when nail polish was simply soaked in warm water (38℃), it took more than 15 minutes for the coating to be partially removed, and there was still obvious residue.

[0043] In summary, the coating of this invention combines high stability during the use stage with controllable degradation during the removal stage. The substrate reuse rate in industrial scenarios is ≥98%, and the VOC content in nail salon scenarios is low and easy to remove, thus achieving environmental protection and controllability throughout the entire life cycle of the coating.

Claims

1. A film-forming aid, characterized in that, The product comprises, by mass parts, the following components: 15-25 parts of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, 30-40 parts of aqueous polyurethane dispersion, 5-8 parts of propylene glycol methyl ether acetate, 1-2 parts of polyether-modified silicone leveling agent, 0.02-0.05 parts of TACN Mn metal catalyst, and 20-30 parts of deionized water; wherein the TACN Mn metal catalyst is a triazacyclononane manganese(II) complex.

2. The film-forming aid according to claim 1, characterized in that, By weight, it includes the following components: 20 parts of 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate, 35 parts of aqueous polyurethane dispersion, 6 parts of propylene glycol methyl ether acetate, 1.5 parts of polyether-modified silicone leveling agent, 0.03 parts of TACN Mn metal catalyst, and 27-28 parts of deionized water.

3. A preparation process for the film-forming aid according to claim 1 or 2, characterized in that, Includes the following steps: 1) Premixed leveling agent: Mix deionized water with polyether modified silicone leveling agent and stir at a low speed of 300-400 r / min for 5-8 min to obtain a premixed solution; 2) Preparation of composite additive solution: Add 2,2,4-trimethyl-1,3-pentanediol di-n-butyrate and propylene glycol methyl ether acetate to the premixed solution, heat to 40-45℃, stir at a medium speed of 500-600 r / min for 10-15 min, then add TACNMn metal catalyst and maintain the temperature at 40-45℃ while stirring for 3-5 min to obtain composite additive solution; 3) Compounding and molding: Add water-based polyurethane dispersion to the compound additive liquid, cool to 25-30℃, stir at a low speed of 200-300r / min for 20-25min, and filter through a 500-mesh filter to obtain the finished film-forming aid.

4. A water-based, catalytically degradable, washable coating containing the film-forming aid of claim 1 or 2, characterized in that, By weight, when applicable to billboard / exhibition special building scenarios, it includes the following components: 25-30 parts of the film-forming aid, 35-45 parts of water-based acrylic resin, 5-10 parts of water-based color paste, 0.5-1 parts of water-based thickener, 15-25 parts of deionized water, 0.1-0.2 parts of preservative and antibacterial agent, and 1-2 parts of benzotriazole anti-UV additive; When applicable to water-based nail polish applications, the following components are included: 20-25 parts of the film-forming aid, 35-45 parts of water-based acrylic resin, 5-10 parts of water-based pigment, 0.5-1 part of water-based thickener, 10-17 parts of deionized water, and 0.1-0.2 parts of phenoxyethanol antibacterial agent.

5. The water-based, catalytically degradable, washable coating as described in claim 4, characterized in that, The water-based color paste is selected from at least one of titanium dioxide water-based color paste, phthalocyanine blue water-based color paste, and CI acid red 52 water-based color paste; the water-based thickener is selected from at least one of polyether modified polyurethane thickener, polyacrylate alkali-swelling thickener, and hydroxyethyl cellulose.

6. The water-based, catalytically degradable, washable coating as described in claim 4, characterized in that, The preservative and antibacterial agent is at least one of CMIT / MIT compound, 1,2-benzisothiazolin-3-one, and phenoxyethanol; the benzotriazole UV-resistant adjuvant is at least one of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole.

7. A construction process for a water-based, catalytically degradable, washable coating as described in any one of claims 4 to 6, characterized in that, Includes the following steps: (1) Substrate pretreatment: Dust removal and oil removal of billboard boards / exhibition special decoration substrates and drying to surface moisture content ≤1%; degreasing and cleaning of nail surfaces and removal of surface cuticle layer; (2) Coating preparation: Mix the film-forming aid with the remaining components of the coating evenly, let stand to defoam for 10-15 minutes; add water to control the viscosity of the system to 1500-2500 mPa·s; (3) Coating application: The substrate of the billboard / exhibition special exhibition is coated by roller or spray, with a single coating thickness of 30-50μm. After 30-40 minutes of surface drying at room temperature, the coating is repeated 1-2 times; the nail polish is applied by brush, with a single brush coating thickness of 5-10μm. After 5-8 minutes of surface drying, the top coat is applied. (4) Curing and molding: The coatings for all scenarios are cured for 2-4 hours at 25-30℃ and 50%-60% humidity.

8. A method for removing a water-based, catalytically degradable, washable coating as described in any one of claims 4 to 6, characterized in that, The specific steps are as follows: (1) Billboard / Exhibition special building scene: First, spray or brush a sodium percarbonate aqueous solution with a mass concentration of 5%-8% evenly onto the coating surface, let it stand for 10-15 minutes, and then use a high-pressure water gun with a pressure of 0.8-1.2MPa to rinse it, so that the coating can be completely peeled off without damaging the substrate. (2) Water-based nail polish scenario: Soak the nails in a warm sodium percarbonate solution at a temperature of 35-40℃ and a mass concentration of 3%-5% for 2-3 minutes, and wipe with a cotton pad to completely remove the polish without leaving any residue and without irritating the nail surface.

9. The application of the water-based catalytically degradable and washable coating as described in any one of claims 4 to 6 in billboard / exhibition special building scenarios or water-based nail polish scenarios.

10. The use of the film-forming aid of claim 1 or 2 in the preparation of water-based replaceable coatings for billboards, temporary coatings for exhibition buildings, or water-based nail polish.

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