A waterproof and fireproof paint for a painting process, a preparation method thereof, and a painting process

Abstract

The present application relates to the technical field of high-performance coatings, and discloses a waterproof and fireproof paint for a painting process, a preparation method of the waterproof and fireproof paint and the painting process. The paint takes natural raw lacquer as a base material, and comprises core-shell structure modified nano fireproof fillers, a hydrophobic modified compound and a crosslinking agent and the like. The preparation method comprises the preparation of the core-shell structure modified nano fireproof fillers, the pre-dispersion of the hydrophobic modified compound, segmented mixing and compounding. The painting process covers body treatment, base coating, intermediate coating, decoration and surface coating gloss. Through the synergistic effect of the self-assembled core-shell structure, the double crosslinking network and the hydrophobic compound, the present application makes the paint film retain the natural raw lacquer warm luster and color levels, significantly improves the defects of the traditional raw lacquer, such as softening when encountering water and carbonization at high temperature, and adapts to the traditional painting technique.

Description

Technical Field

[0001] This invention relates to the field of high-performance coatings technology, specifically to a waterproof and fireproof coating for lacquering processes, its preparation method, and the lacquering process thereof. Background Technology

[0002] Natural lacquer (also known as raw lacquer) is a natural latex composed of urushiol, laccase, gums, and water. The main film-forming substance, urushiol, is a mixture of catechols with unsaturated straight-chain groups. Under the catalysis of laccase, it undergoes oxidative polymerization to form a polymer network. After drying, the resulting film exhibits excellent corrosion resistance, abrasion resistance, and durability. The curing of raw lacquer requires specific temperature and humidity conditions, and the activity of laccase directly affects the drying speed and final properties of the lacquer film. With its warm luster and rich, delicate texture, natural lacquer enjoys the reputation of "King of Coatings" in the history of lacquerware craftsmanship.

[0003] However, traditional raw lacquer has two inherent drawbacks in complex environments: first, the lacquer film softens easily when exposed to water, leading to wrinkling, whitening, and peeling after absorbing moisture, limiting the application of lacquered products in humid outdoor environments; second, the lacquer film is prone to carbonization and degradation under high-temperature conditions, resulting in insufficient flame retardant properties and making it difficult to meet the fire protection requirements of public places and building decoration. To address these issues, researchers have attempted to modify natural raw lacquer.

[0004] Chinese invention patent CN103589268B discloses a nano-modified raw lacquer and its preparation method. The nano-modified raw lacquer is prepared using urushiol, aldehyde compounds, and nano-cellulose / nano-silica hybrid fillers, improving the water resistance, abrasion resistance, and adhesion of the raw lacquer. Chinese invention patent CN110776828B discloses a dendritic polyamide-amine (PAMAM) modified raw lacquer coating and its preparation method. PAMAM is added to the raw lacquer liquid at 0.2%-5% of the raw lacquer mass, and the coating is formed by drying at 120℃ for 6 hours, significantly improving the hardness, adhesion, elasticity, and impact resistance of the raw lacquer.

[0005] However, the existing technologies still have the following shortcomings: First, although CN103589268B improves water resistance, it does not address the improvement of fire resistance; Second, CN110776828B uses 120℃ high-temperature curing, which destroys the natural catalytic activity of lacquer enzymes in raw lacquer, resulting in damage to the density and aesthetic quality of the paint film; Third, the existing technologies have not solved the problem of synergistic effects between waterproofing and fireproofing, and the simple blending of waterproofing and fireproofing modifiers presents technical obstacles such as component incompatibility, uneven dispersion, and mutual inhibition of functions; Fourth, the existing modification technologies mainly focus on improving the basic physical and chemical properties of the coatings and have failed to achieve good compatibility with traditional lacquer finishing techniques such as gilding, inlaying, and lacquerware.

[0006] Therefore, there is an urgent need to develop a coating and its preparation method that can preserve the aesthetic qualities of natural lacquer, provide highly efficient waterproof and fireproof properties, and be well-suited to lacquer finishing techniques. Summary of the Invention

[0007] The purpose of this invention is to provide a waterproof and fireproof coating for lacquering processes, its preparation method, and the lacquering process thereof, in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, on the one hand, the present invention provides a waterproof and fireproof coating for lacquering processes, comprising, by weight: 100 parts of natural lacquer, 8-22 parts of core-shell modified nano-fireproof filler, 3-8 parts of hydrophobic modified compound, 5-12 parts of crosslinking agent, and 15-35 parts of diluent; the core of the core-shell modified nano-fireproof filler is a composite core composed of nano-silica modified with γ-aminopropyltriethoxysilane and nano-aluminum hydroxide, wherein the mass ratio of nano-silica to nano-aluminum hydroxide is 1:(0.8-2.5), and the shell of the core-shell modified nano-fireproof filler is a dendritic polyamide-amine shell layer coated by electrostatic induction self-assembly under pH 5.0-6.5 conditions.

[0009] Urushiol in natural lacquer provides the film-forming framework and reactive sites. Core-shell modified nano-fire-retardant fillers are constructed using a two-step method: surface chemical modification with γ-aminopropyltriethoxysilane (KH550) and a dendritic polyamide-amine (PAMAM) shell to create a self-assembled structure. KH550, with its molecular structure NH2—(CH2)3—Si(OCH2CH3)3, is chosen as the silane coupling agent. The terminal amino group (—NH2) forms hydrogen bonds and chemical crosslinks with urushiol in the subsequent system. Unlike KH560 (containing epoxy groups), which carries the risk of competing reactions with the terminal amino groups of PAMAM, KH550 fundamentally avoids this chemical conflict. Under pH 5.0–6.5 conditions, the surface of the KH550-modified nanofiller exhibits deprotonation of silanol, resulting in a negative charge (zeta potential of approximately -15 to -25 mV), and the terminal amino group of the PAMAM molecule is protonated to —NH3. + Exhibiting a positive charge (zeta potential of approximately +25 to +35 mV), PAMAM molecules spontaneously adsorb onto the filler surface through electrostatic attraction, forming a dense shell. Nano-aluminum hydroxide and nano-silica constitute a synergistic flame-retardant dual-component system. During combustion, they undergo endothermic decomposition to form an Al2O3 thermal barrier, while nano-silica fills the char pores, enhancing the dense barrier.

[0010] Preferably, the dendritic polyamide-amine shell accounts for 10%-30% of the total mass of the core-shell structure modified nano fire-retardant filler, and the shell thickness is 5-15 nm.

[0011] Preferably, the γ-aminopropyltriethoxysilane accounts for 3%-8% of the total mass of the composite nucleus.

[0012] Preferably, the hydrophobic modified compound is a mixture of heptadecafluorodecyltrimethoxysilane and hydroxyl-terminated polydimethylsiloxane, with a mass ratio of heptadecafluorodecyltrimethoxysilane to hydroxyl-terminated polydimethylsiloxane of 1:0.8-1.5. Both components contain active groups that can participate in condensation reactions, and can form covalent bonds with the phenolic hydroxyl groups of urushiol to anchor to the paint film network through dehydration condensation. The water contact angle can reach over 130°, fundamentally solving the long-term durability problem of hydrophobic components.

[0013] Preferably, the crosslinking agent is a mixture of dendritic polyamide-amine and tetraethyl orthosilicate, with a mass ratio of dendritic polyamide-amine to tetraethyl orthosilicate of 1:1.2-2.5. Dendritic polyamide-amine (PAMAM) forms organic crosslinking nodes through dehydration condensation of dense amino groups with the phenolic hydroxyl groups of urushiol; tetraethyl orthosilicate (TEOS) hydrolyzes in a system with trace amounts of moisture and an acidic environment to generate silanol intermediates, which further undergo condensation polymerization with the hydroxyl groups of urushiol to generate Si—O—C bonds, and simultaneously condense with the silanol groups on the surface of the nanofiller to generate Si—O—Si bonds, thus forming an organic-inorganic interpenetrating double network structure.

[0014] Preferably, the diluent is one or more of ethanol, isopropanol, or ethyl acetate.

[0015] On the other hand, the present invention discloses a method for preparing the above-mentioned waterproof and fireproof coating for lacquering processes, comprising the following steps: (1) Nano silica and nano aluminum hydroxide were mixed in proportion, and surface modified with γ-aminopropyltriethoxysilane. Then, dendritic polyamide-amine was added under pH 5.0-6.5 conditions for electrostatic self-assembly. After drying, core-shell structure modified nano fireproof filler was obtained. (2) Mix the hydrophobic modified compound with the diluent according to the ratio, and disperse it by ultrasonication to obtain a hydrophobic pre-dispersion liquid. The ultrasonic cavitation effect acts on the molecular chains of the two polymers, so that they are fully extended and uniformly dispersed, avoiding phase separation and agglomeration caused by excessive local concentration of the hydrophobic component when it is added later.

[0016] (3) Mix the crosslinking agent with natural lacquer at 15-25℃ according to the specified ratio and stir for 10-25 min; raise the temperature to 35-45℃ and add the core-shell structure modified nano fireproof filler in 2-4 batches, with an interval of 5-15 min each time, stirring until uniform to obtain a mixture; the first stage adds the crosslinking agent at a low temperature of 15-25℃, which can avoid the influence of premature heating on laccase activity. At the same time, urushiol has a certain viscosity at this temperature, which is conducive to the initial mixing of the crosslinking agent and the formation of the pre-crosslinked structure. The second stage raises the temperature to 35-45℃ to appropriately reduce the viscosity of the lacquer, which is conducive to the dispersion of the filler when it is added later, while keeping it within the laccase activity window (laccase has the highest activity at 40℃). The gradient dispersion strategy of adding the filler in batches avoids the aggregation caused by excessive local concentration and ensures the integrity of the self-assembled core-shell structure.

[0017] (4) Add the hydrophobic pre-dispersion liquid to the mixture, stir at 35-50℃ for 20-40 minutes, cool to room temperature, let stand to degas, and obtain waterproof and fireproof coating.

[0018] In step (3), before adding the core-shell structure modified nano fire-retardant filler, a pre-dispersion step is also included. Specifically, the core-shell structure modified nano fire-retardant filler is added to a diluent (20-30% of the total diluent) (the diluent in step (2) is 70-80% of the total diluent), and ultrasonically pre-dispersed for 10-20 minutes (frequency 40kHz, power 200-250W) to prepare a filler pre-dispersion slurry. The pre-dispersion of the filler and its addition in slurry form can avoid the agglomeration caused by the difficulty in dispersing dry powder in low-polarity raw lacquer, and significantly improve the uniform distribution of the filler in the raw lacquer matrix.

[0019] Preferably, the ultrasonic dispersion in step (2) has a frequency of 40kHz, a power of 200-300W, and a duration of 15-25min.

[0020] Preferably, after adjusting the pH to 5.0-6.5 in step (1), dendritic polyamide-amine is added and stirred at 20-30℃ for 15-30 min to carry out self-assembly, then centrifuged and vacuum dried at 40-60℃ for 8-12 h.

[0021] Furthermore, this invention also discloses a finishing process for the above-mentioned waterproof and fireproof coating used in finishing processes, comprising the following steps: (1) Body treatment: The body to be modified is sanded with 80-400 grit sandpaper, cleaned and dried; (2) Primer: Apply waterproof and fireproof coating to the surface of the substrate, with a wet film thickness of 60-120μm, and allow it to dry naturally for 12-24 hours at 20-30℃ and 60%-85% relative humidity; (3) Intermediate coating and decoration: Repeat step (2) 1-3 times, sanding after each drying, and then decorate the paint surface after the base coat or intermediate coat has cured; (4) Topcoat and polishing: Apply waterproof and fireproof coating as topcoat to the surface of the decorative layer. The wet film thickness is 60-100μm. Curing is carried out under any of the following conditions: ① 40-60℃, relative humidity 60%-85%, curing for 12-48h; or ② 20-30℃, relative humidity 60%-85%, curing for 48-120h. Then, sanding, polishing and cleaning are carried out in sequence.

[0022] Medium-temperature curing (40-60℃) utilizes the high activity of laccase maintained at 45-55℃ to accelerate the oxidative polymerization of urushiol; at the same time, TEOS undergoes hydrolysis in trace amounts of water in the system, and the silanol intermediate condenses with the urushiol hydroxyl group; the covalent anchoring of the hydrophobic complex in the composite system is completed in the curing stage, and the paint film has comprehensive properties of high density, hydrophobicity and flame retardancy.

[0023] The beneficial effects of this invention are as follows: This invention utilizes a core-shell structured nano-fire-retardant filler constructed through KH550 surface modification and pH-responsive electrostatic self-assembly, a PAMAM-TEOS organic-inorganic dual crosslinked network, and a fluorosilane / hydroxyl-terminated polydimethylsiloxane two-component covalently anchored hydrophobic system. These three components synergistically act on a natural lacquer matrix, enabling the coating to retain the traditional aesthetic characteristics of lacquer, such as its warm luster, rich texture, and color gradation, while simultaneously achieving long-lasting waterproofing and high-efficiency flame retardancy. The preparation process employs segmented temperature control and medium-temperature curing, fully protecting the natural catalytic activity of laccase and avoiding damage to the film's transparency and color caused by high-temperature curing. This coating is highly compatible with traditional lacquer techniques such as gilding, inlaid gold, and lacquerware, offering simple and reliable application. The coating exhibits strong adhesion, high hardness, and long-lasting weather resistance, significantly extending the service life of lacquered products in complex outdoor environments such as high humidity and high temperature.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0025] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0026] It should be noted that all reagents and raw materials used in this invention are commercially available, and the reagents are of analytical grade.

[0027] The natural raw lacquer was sourced from Chengdu Meixing Craft Paint Factory, model number Mxt-9099. Nano-silica was sourced from Suzhou Youzirconium Nanomaterials Co., Ltd., model number UG-SP15. Nano-aluminum hydroxide was sourced from Suzhou Youzirconium Nanomaterials Co., Ltd., model number UG-L30N. Hydroxyl-terminated polydimethylsiloxane was sourced from Shandong Yousuo Chemical Technology Co., Ltd., model number PMX-0156. Dendritic polyamide-amine was purchased from Weihai Chenyuan Molecular New Materials Co., Ltd., model number CYD-120A. Example 1

[0028] This embodiment discloses a method for preparing a waterproof and fireproof coating for lacquer finishing processes.

[0029] Component content (parts by weight): 100g of natural raw lacquer, 15g of core-shell structure modified nano fireproof filler (nano silica and nano aluminum hydroxide mass ratio 1:1.5), 5g of hydrophobic modified compound (heptadecyltrimethoxysilane: hydroxyl-terminated polydimethylsiloxane (mass ratio) = 1:1.2), 8g of crosslinking agent (dendritic polyamide-amine: tetraethyl orthosilicate (mass ratio) = 1:1.8), and 25g of diluent (ethanol) (of which 19g is used for pre-dispersion in step (2) and 6g is used for filler pre-dispersion in step (3)).

[0030] (1) Preparation of core-shell structure modified nano fireproof filler ① KH550 pre-hydrolysis: Dissolve 0.64g KH550 in an ethanol-water mixed solution (V(ethanol):V(water)=9:1, total volume 13mL), stir and hydrolyze at 30℃ for 30min to obtain hydrolysate; ② Surface grafting modification: Mix 5.5g of nano-silica and 8.25g of nano-aluminum hydroxide, add hydrolysate, stir and react at 65℃ for 3h, centrifuge after reaction (4000rpm, 10min), wash once with anhydrous ethanol, discard the supernatant, redisperse the precipitate in 85mL of deionized water to form a suspension; ③ pH adjustment and electrostatic self-assembly: The pH of the suspension was adjusted to 5.8 with dilute hydrochloric acid (0.1 mol / L), and the zeta potential was measured (approximately -20 mV). Under stirring conditions, an aqueous solution of dendritic polyamide-amine (3.44 g of dendritic polyamide-amine dissolved in 25 mL of deionized water) was added dropwise. The mixture was stirred at 25 °C for 25 min, and the zeta potential was measured again to confirm that it had changed to approximately +30 mV. ④ Centrifugation and drying: Centrifuge the product from step ③ (4000 rpm, 10 min), discard the supernatant, wash the precipitate once with deionized water (20 mL), place the precipitate in a vacuum drying oven at 50℃ and dry for 10 h (vacuum degree -0.08 MPa), grind after drying and pass through a 200-mesh sieve to obtain core-shell structure modified nano fireproof filler.

[0031] (2) Pre-dispersion of hydrophobically modified compound Add 5g of hydrophobic modified compound to 19g of diluent, place in an ultrasonic cleaner (frequency 40kHz, power 250W), and ultrasonically disperse for 20min (pause for 30s every 5min to prevent overheating) to obtain a hydrophobic pre-dispersion.

[0032] (3) Segmented mixing Place the natural lacquer in a 250mL glass reaction bottle, add the crosslinking agent in a constant temperature water bath at 20℃, stir magnetically for 20min, raise the temperature to 40℃, add 15g of the core-shell structure modified nano fireproof filler obtained in step (1) to 6g of diluent, and pre-disperse ultrasonically for 15min (frequency 40kHz, power 200W) to obtain the filler pre-dispersion slurry; add the filler pre-dispersion slurry into the reaction bottle in three equal portions, with an interval of 10min each time, and stir until the system is uniform; then continue stirring at 40℃ for 15min.

[0033] (4) Composite Add all of the hydrophobic pre-dispersion from step (2) into the reaction flask from step (3), stir for 30 minutes in a 45°C water bath, then cool to room temperature and let stand for 25 minutes to remove bubbles, thus obtaining a waterproof and fireproof coating.

[0034] Preparation of paint film samples: The obtained coating was evenly applied to the pre-treated linden wood decorative board (120mm×60mm×5mm), with a wet film thickness of about 100μm. The sample was placed in a constant temperature and humidity incubator, with the temperature set at 45℃ and the relative humidity at 75%, and cured for 24h. Example 2

[0035] This embodiment discloses a method for preparing a waterproof and fireproof coating for lacquer finishing processes.

[0036] Component content (parts by weight): 100g of natural raw lacquer, 8g of core-shell structure modified nano fireproof filler (nano silica and nano aluminum hydroxide mass ratio 1:0.8), 8g of hydrophobic modified compound (heptadecyltrimethoxysilane: hydroxyl-terminated polydimethylsiloxane (mass ratio) = 1:1.5), 5g of crosslinking agent (dendritic polyamide-amine: tetraethyl orthosilicate (mass ratio) = 1:1.2), 25g of diluent (isopropanol 20g + ethyl acetate 5g) (of which 20g is used for pre-dispersion in step (2) and 5g is used for pre-dispersion of filler in step (3)).

[0037] (1) Preparation of core-shell structure modified nano fireproof filler ①Pre-hydrolysis of KH550: Dissolve 0.29g of KH550 in a mixed ethanol-water solution (V(ethanol):V(water)=9:1, total volume 13mL), stir and hydrolyze at 30℃ for 30min to obtain hydrolysate; ② Surface grafting modification: Mix 5g of nano-silica and 4.0g of nano-aluminum hydroxide, add hydrolysate, stir and react at 65℃ for 3h, centrifuge after the reaction is completed (4000rpm, 10min), wash once with anhydrous ethanol, discard the supernatant, redisperse the precipitate in 85mL of deionized water to form a suspension; ③ pH adjustment and electrostatic self-assembly: The pH of the suspension was adjusted to 5.0 with dilute hydrochloric acid (0.1 mol / L), and the zeta potential was measured (approximately -20 mV). Under stirring conditions, an aqueous solution of dendritic polyamide-amine (1.0 g of dendritic polyamide-amine dissolved in 20 mL of deionized water) was added dropwise. The mixture was stirred at 20 °C for 30 min, and the zeta potential was measured again to confirm that it had changed to approximately +30 mV. ④ Centrifugation and drying: Centrifuge the product from step ③ (4000 rpm, 10 min), discard the supernatant, wash the precipitate once with deionized water (20 mL), place the precipitate in a vacuum drying oven at 40℃ and dry for 12 h (vacuum degree -0.08 MPa), grind after drying and pass through a 200-mesh sieve to obtain core-shell structure modified nano fireproof filler.

[0038] (2) Pre-dispersion of hydrophobically modified compound Add 8g of the hydrophobic modified compound to 20g of diluent, place it in an ultrasonic cleaner (frequency 40kHz, power 200W), and ultrasonically disperse for 25min (pause for 30s every 5min to prevent overheating) to obtain a hydrophobic pre-dispersion.

[0039] (3) Segmented mixing Place the natural lacquer in a 250mL glass reaction bottle, add the crosslinking agent in a constant temperature water bath at 15℃, stir magnetically for 25min, raise the temperature to 35℃, add 8g of the core-shell structure modified nano fireproof filler obtained in step (1) to 5g of diluent, and pre-disperse ultrasonically for 15min (frequency 40kHz, power 200W) to obtain the filler pre-dispersion slurry; add the filler pre-dispersion slurry into the reaction bottle in three equal portions, with an interval of 5min each time, and stir until the system is uniform; then continue stirring at 35℃ for 15min.

[0040] (4) Composite Add all of the hydrophobic pre-dispersion from step (2) into the reaction flask from step (3), stir for 40 minutes in a 35°C water bath, then cool to room temperature and let stand for 25 minutes to remove bubbles, thus obtaining a waterproof and fireproof coating.

[0041] Preparation of paint film samples: The obtained coating was evenly applied to the pre-treated linden wood decorative board (120mm×60mm×5mm), with a wet film thickness of about 100μm. The sample was placed in a constant temperature and humidity incubator, with the temperature set at 55℃ and the relative humidity at 70%, and cured for 16h. Example 3

[0042] This embodiment discloses a method for preparing a waterproof and fireproof coating for lacquer finishing processes.

[0043] Component content (parts by weight): 100g of natural raw lacquer, 22g of core-shell structure modified nano fireproof filler (nano silica and nano aluminum hydroxide mass ratio 1:2.5), 3g of hydrophobic modified compound (heptadecyltrimethoxysilane: hydroxyl-terminated polydimethylsiloxane (mass ratio) = 1:0.8), 12g of crosslinking agent (dendritic polyamide-amine: tetraethyl orthosilicate (mass ratio) = 1:2.5), and 35g of diluent (ethyl acetate) (of which 25g is used for pre-dispersion in step (2) and 10g is used for pre-dispersion of filler in step (3)).

[0044] (1) Preparation of core-shell structure modified nano fireproof filler ① KH550 pre-hydrolysis: Dissolve 1.38g KH550 in an ethanol-water mixture (V(ethanol):V(water)=9:1, total volume 20mL), stir and hydrolyze at 30℃ for 30min to obtain hydrolysate; ② Surface grafting modification: Mix 6g of nano-silica and 15g of nano-aluminum hydroxide, add hydrolysate, stir and react at 65℃ for 3h, centrifuge after reaction (4000rpm, 10min), wash once with anhydrous ethanol, discard the supernatant, redisperse the precipitate in 120mL of deionized water to form a suspension. ③ pH adjustment and electrostatic self-assembly: The pH of the suspension was adjusted to 6.5 with dilute hydrochloric acid (0.1 mol / L), and the zeta potential was measured (approximately -20 mV). Under stirring conditions, an aqueous solution of dendritic polyamide-amine (9.0 g of dendritic polyamide-amine dissolved in 50 mL of deionized water) was added dropwise. The mixture was stirred at 30 °C for 15 min, and the zeta potential was measured again to confirm that it had changed to approximately +30 mV. ④ Centrifugation and drying: Centrifuge the product from step ③ (4000 rpm, 10 min), discard the supernatant, wash the precipitate once with deionized water (20 mL), place the precipitate in a vacuum drying oven at 60℃ and dry for 8 h (vacuum degree -0.08 MPa), grind after drying and pass through a 200-mesh sieve to obtain core-shell structure modified nano fireproof filler.

[0045] (2) Pre-dispersion of hydrophobically modified compound Add 3g of hydrophobic modified compound to 25g of diluent, place in an ultrasonic cleaner (frequency 40kHz, power 300W), and ultrasonically disperse for 15min (pause for 30s every 5min to prevent overheating) to obtain a hydrophobic pre-dispersion.

[0046] (3) Segmented mixing Place the natural lacquer in a 250mL glass reaction bottle, add the crosslinking agent in a constant temperature water bath at 25℃, stir magnetically for 10min, raise the temperature to 45℃, add 22g of the core-shell structure modified nano fireproof filler obtained in step (1) to 10g of diluent, and ultrasonically pre-disperse for 15min (frequency 40kHz, power 200W) to obtain the filler pre-dispersion slurry; add the filler pre-dispersion slurry into the reaction bottle in three equal portions, with an interval of 15min each time, and stir until the system is uniform; then continue stirring at 45℃ for 15min.

[0047] (4) Composite Add all of the hydrophobic pre-dispersion from step (2) into the reaction flask from step (3), stir for 20 minutes in a 50°C water bath, then cool to room temperature and let stand for 25 minutes to remove bubbles, thus obtaining a waterproof and fireproof coating.

[0048] Preparation of paint film samples: The obtained coating was evenly applied to the pre-treated linden wood decorative board (120mm×60mm×5mm), with a wet film thickness of about 100μm. The sample was placed in a constant temperature and humidity incubator, with the temperature set at 60℃ and the relative humidity at 70%, and cured for 12h. Example 4

[0049] This embodiment discloses a method for preparing a waterproof and fireproof coating for lacquer finishing processes.

[0050] Component content (parts by weight): 100g of natural raw lacquer, 12g of core-shell structure modified nano fireproof filler (nano silica and nano aluminum hydroxide mass ratio 1:1.9), 4g of hydrophobic modified compound (heptadecyltrimethoxysilane: hydroxyl-terminated polydimethylsiloxane (mass ratio) = 1:1.1), 9g of crosslinking agent (dendritic polyamide-amine: tetraethyl orthosilicate (mass ratio) = 1:2.0), and 22g of diluent (ethyl acetate) (of which 16g is used for pre-dispersion in step (2) and 6g is used for filler pre-dispersion in step (3)).

[0051] (1) Preparation of core-shell structure modified nano fireproof filler ① KH550 pre-hydrolysis: Dissolve 0.54g KH550 in an ethanol-water mixed solution (V(ethanol):V(water)=9:1, total volume 15mL), stir and hydrolyze at 30℃ for 30min to obtain hydrolysate; ② Surface grafting modification: Mix 4g of nano-silica and 7.6g of nano-aluminum hydroxide, add hydrolysate, stir and react at 65℃ for 3h, centrifuge after the reaction is completed (4000rpm, 10min), wash once with anhydrous ethanol, discard the supernatant, redisperse the precipitate in 120mL of deionized water to form a suspension; ③ pH adjustment and electrostatic self-assembly: The pH of the suspension was adjusted to 5.5 with dilute hydrochloric acid (0.1 mol / L), and the zeta potential was measured (approximately -20 mV). Under stirring conditions, an aqueous solution of dendritic polyamide-amine (2.05 g of dendritic polyamide-amine dissolved in 25 mL of deionized water) was added dropwise. The mixture was stirred at 30 °C for 15 min, and the zeta potential was measured again to confirm that it had changed to approximately +30 mV. ④ Centrifugation and drying: Centrifuge the product from step ③ (4000 rpm, 10 min), discard the supernatant, wash the precipitate once with deionized water (20 mL), place the precipitate in a vacuum drying oven at 55℃ and dry for 10 h (vacuum degree -0.08 MPa), grind after drying and pass through a 200-mesh sieve to obtain core-shell structure modified nano fireproof filler.

[0052] (2) Pre-dispersion of hydrophobically modified compound Add 4g of hydrophobic modified compound to 16g of diluent, place in an ultrasonic cleaner (frequency 40kHz, power 250W), and ultrasonically disperse for 20min (pause for 30s every 5min to prevent overheating) to obtain a hydrophobic pre-dispersion.

[0053] (3) Segmented mixing Place the natural lacquer in a 250mL glass reaction bottle, add the crosslinking agent in a constant temperature water bath at 20℃, stir magnetically for 15min, raise the temperature to 40℃, add 12g of the core-shell structure modified nano fireproof filler obtained in step (1) to 6g of diluent, and pre-disperse ultrasonically for 18min (frequency 40kHz, power 220W) to obtain the filler pre-dispersion slurry; add the filler pre-dispersion slurry into the reaction bottle in three equal portions, with an interval of 10min each time, and stir until the system is uniform; then continue stirring at 40℃ for 15min.

[0054] (4) Composite Add all of the hydrophobic pre-dispersion from step (2) into the reaction flask from step (3), stir for 18 minutes in a 45°C water bath, then cool to room temperature and let stand for 25 minutes to remove bubbles, thus obtaining a waterproof and fireproof coating.

[0055] Preparation of paint film samples: The obtained coating was evenly applied to the pre-treated linden wood decorative board (120mm×60mm×5mm), with a wet film thickness of about 100μm. The sample was placed in a constant temperature and humidity incubator, with the temperature set at 25℃ and the relative humidity at 80%, and cured for 96h.

[0056] Comparative Example 1 Compared with Example 1, the difference is that no hydrophobic modified compound is added, step (2) is not included, all the diluent is added during the filler dispersion process in step (3), and the remaining components and preparation conditions are the same as in Example 1.

[0057] Comparative Example 2 Compared with Example 1, the difference is that step (1) is not included. The core-shell structure modified nano fireproof filler is replaced by a mixed nanofiller obtained by directly physical stirring and mixing 6g of nano silica and 9g of nano aluminum hydroxide for 15min. The remaining components and preparation conditions are the same as in Example 1.

[0058] Comparative Example 3 Compared with Example 1, the difference is that it does not contain a dendritic polyamide-amine shell, and the specific steps in step (1) are as follows: ① KH550 pre-hydrolysis: Dissolve 0.64g KH550 in an ethanol-water mixed solution (V(ethanol):V(water)=9:1, total volume 13mL), stir and hydrolyze at 30℃ for 30min to obtain hydrolysate; ② Surface grafting modification: 6g of nano-silica and 9g of nano-aluminum hydroxide were mixed, hydrolysate was added, and the mixture was stirred at 65℃ for 3h. After the reaction was completed, the mixture was centrifuged (4000rpm, 10min), washed once with anhydrous ethanol, and the supernatant was discarded. The precipitate was vacuum dried at 50℃ for 10h, ground and passed through a 200-mesh sieve to obtain a mixed filler modified only with KH550. The core-shell structure modified nano fireproof filler was replaced with the KH550 modified mixed filler. The remaining components and preparation conditions are the same as in Example 1.

[0059] Comparative Example 4 Compared with Example 1, the difference is that no crosslinking agent is added, the step of adding crosslinking agent in step (3) is cancelled, and the remaining components and preparation conditions are the same as in Example 1.

[0060] Comparative Example 5 Compared with Example 1, the difference is that the crosslinking agent is only 8g of dendritic polyamide-amine, and does not contain tetraethyl orthosilicate. The remaining components and preparation conditions are the same as in Example 1.

[0061] Comparative Example 6 Compared with Example 1, the difference is that the crosslinking agent is only 8g of tetraethyl orthosilicate, and it does not contain dendritic polyamide-amine. The other components and preparation conditions are the same as in Example 1.

[0062] Comparative Example 7 Compared with Example 1, the difference is that the temperature in step (3) of segmented mixing is changed to room temperature throughout: 100g of natural raw lacquer is placed in a reaction bottle, and crosslinking agent is added at room temperature (about 25°C) and stirred for 20min; without raising the temperature, 15g of core-shell structure modified nano fireproof filler is added to 6g of diluent and ultrasonically pre-dispersed for 15min, added in 3 portions with an interval of 10min each time; stirring is continued for 15min.

[0063] In the preparation of the paint film sample, the curing conditions were as follows: the coating film was placed in an oven at 120℃ and dried for 6 hours.

[0064] The remaining components and preparation conditions are the same as in Example 1.

[0065] Comparative Example 8 Compared with Example 1, the difference is that step (3) is changed to one-step mixing, that is, natural raw lacquer is placed in a 250mL reaction bottle, and the crosslinking agent, core-shell structure modified nano fireproof filler (without ultrasonic pre-dispersion, added directly as dry powder) and hydrophobic pre-dispersion liquid are added at room temperature all at once. No staged heating is performed, and all components are mixed at once and magnetically stirred for 30min. The remaining components and preparation conditions are the same as in Example 1.

[0066] The coatings prepared in Examples 1-4 and Comparative Examples 1-8 were subjected to relevant performance tests. The specific test indicators and methods are as follows: 1. Adhesion: According to the method specified in GB / T 9286-2021 "Paints and Varnishes Cross-cut Test", 25 squares are drawn on the paint film at 1 mm intervals using a cross-cut tester. After being pasted with transparent tape, the squares are quickly peeled off. The degree of paint film peeling is observed and the grade is evaluated (0 is the best, 5 is the worst).

[0067] 2. According to the method specified in GB / T 6739-2022 "Determination of Hardness of Paints and Varnishes by Pencil Method", a set of pencils with known hardness grades (9B to 9H) are used to scratch the paint film surface at a 45° angle under constant pressure. The highest pencil hardness grade that does not scratch the paint film is taken as the hardness value of the paint film.

[0068] 3. Water resistance (240h) and water absorption rate: According to the immersion test method in GB / T 1733—1993 "Determination of Water Resistance of Paint Films", the test panel was vertically immersed in distilled water at (23±2)℃ and kept for 240h. After that, the panel was removed, the surface moisture was absorbed with filter paper, and the paint film was immediately observed for phenomena such as blistering, softening, loss of gloss, discoloration, and peeling. The condition of the paint film was recorded. The water absorption rate was calculated as (mass after immersion - mass before immersion) / mass before immersion × 100%. The mass of the test panel was weighed before immersion and after 240h immersion. Three test panels were tested for each group of samples, and the average value was taken.

[0069] 4. Water contact angle: The water contact angle was measured at room temperature using an optical contact angle meter according to the method specified in GB / T 30693-2014 "Measurement of the contact angle between plastic films and water". Approximately 2 μL of deionized water was dropped onto the surface of the coating film. After the droplet stabilized (approximately 10 s), the static contact angle was measured. Five different locations were measured for each sample, and the arithmetic mean was taken.

[0070] 5. Flame Retardancy Time: Tested according to the large-panel burning method specified in Appendix A of GB 12441-2018 "Decorative Fire Retardant Coatings". Grade I three-layer plywood (900mm×900mm×5mm) is used as the base material, with a viscosity of 500g / m². 2 The wet coating is compared with the uniform coating. After curing under specified conditions, it is placed in a large plate combustion device and the test plate surface is exposed to a standard flame. The time from the start of the fire to the occurrence of damage (such as being burned through, flame appearing on the unexposed side, or continuous burning for more than 10 seconds) is recorded as the flame resistance time.

[0071] 6. Mass Loss: In accordance with Appendix A of GB 12441-2018 "Fire-retardant Coatings for Decorative Surfaces", the mass of the test panels was weighed before and after the large panel burning test. The mass loss is the mass before burning minus the mass after burning. This indicator reflects the degree of thermal decomposition and carbonization of the coating under flame. The smaller the mass loss, the better the flame retardant performance.

[0072] The performance test results are shown in Table 1.

[0073] Table 1 Performance Test Results Example 1 1 4H No foaming, no softening 1.22 138.7 425 6.8 Example 2 0 3H No foaming, no softening 0.91 145.4 378 8.2 Example 3 1 5H No foaming, no softening 1.78 130.6 451 5.7 Example 4 0 4H No foaming, no softening 1.09 141.5 437 6.3 Comparative Example 1 1 3H Slightly white 4.38 78.3 418 6.9 Comparative Example 2 2 2H soften 7.96 134.7 293 11.6 Comparative Example 3 1 H Slightly white 3.21 135.3 396 7.4 Comparative Example 4 2 HB expansion 6.54 137.1 381 8.8 Comparative Example 5 1 4H Slightly white 2.13 136.8 359 8.7 Comparative Example 6 3 2H microcracks 3.57 132.9 392 7.9 Comparative Example 7 2 3H Cracks 8.63 69.2 396 7.6 Comparative Example 8 2 3H Localized blistering 2.86 131.0 367 7.1 As can be seen from the table above, the coatings prepared in the embodiments of the present invention are superior to those in the comparative examples in terms of performance. The specific reasons are as follows: Regarding waterproof performance: In Comparative Example 1 without hydrophobic modified compound, the water contact angle decreased sharply from 138.7° in Example 1 to 78.3°, and the water absorption rate increased from 1.22% to 4.38%. After 240 hours of immersion in water, the paint film showed obvious whitening. This indicates that the hydrophobic modified compound covalently anchors to the paint film surface to construct a low surface energy hydrophobic layer, which is the key component that gives the coating excellent waterproof performance.

[0074] Regarding filler dispersion and flame retardant properties: Comparative Example 2 (physically mixed filler only) had a flame retardant time of only 293 s and a water absorption rate as high as 7.96%, with significant film softening. Comparative Example 3 (KH550 modified only, without dendritic polyamide-amine shell) had a flame retardant time of 396 s and a water absorption rate reduced to 3.21%. Example 1 had a flame retardant time of 425 s and a water absorption rate of only 1.22%. This indicates that surface chemical grafting of KH550 is the basis for establishing interfacial compatibility between the filler and the raw lacquer, while the electrostatic self-assembled shell of dendritic polyamide-amine further strengthens the filler-matrix bonding and flame retardant synergy; both steps are indispensable.

[0075] Regarding mechanical properties and structural density: Comparative Example 4 (without crosslinking agent) had a pencil hardness of only HB and swelled and deformed after water resistance; Comparative Example 5 (crosslinking agent containing only dendritic polyamide-amine) achieved a hardness of 4H, but its flame resistance time was only 359 s and its mass loss was 8.7 g; Comparative Example 6 (crosslinking agent containing only tetraethyl orthosilicate) had a flame resistance time of 392 s, but its hardness was only 2H, its adhesion was grade 3, and the paint film was prone to cracking; Example 1 simultaneously achieved a hardness of 4H, a flame resistance of 425 s, and a water absorption rate of 1.22%. This indicates that dendritic polyamide-amine mainly contributes to the organic crosslinking network, which imparts hardness and toughness to the paint film, while tetraethyl orthosilicate constitutes an inorganic network that enhances thermal stability and density. The two work together to form an interpenetrating double network, achieving comprehensive performance that cannot be achieved by a single crosslinking agent.

[0076] Regarding film integrity: Comparative Example 7 (cured at 120℃) showed a water absorption rate of 8.63% and a water contact angle of only 69.2°, with cracking and discoloration appearing in the film. This comparison demonstrates that even with high-temperature curing, the laccase and natural pigments in the raw lacquer will still be destroyed, and the chemical anchoring of the hydrophobic components will fail, leading to irreversible damage to aesthetic quality and film integrity. Segmented temperature control and medium-temperature curing are necessary process conditions to preserve the excellent performance of the coating of this invention.

[0077] Regarding the uniform dispersion of fillers: In Comparative Example 8 (all components added at once, without staged heating, and fillers added directly as dry powder), the flame retardancy time decreased to 367 s, the water absorption rate increased to 2.86%, and localized blistering appeared in the paint film. Compared with Example 1, the dry powder filler in Comparative Example 8 was difficult to fully wet and disperse in the viscous raw lacquer, and the defects formed by agglomeration became water penetration channels and weakened the flame-retardant synergistic effect of the filler. This verifies that the staged mixing and ultrasonic pre-dispersion process of the present invention is a key step to ensure the uniform distribution of core-shell structure fillers in the paint film and to fully exert their function.

[0078] Application Example 1 - Outdoor Weather Resistance Application - Wood Structure Building Door and Window Components Two sets of red pine carved door and window components of the same specifications (2 pieces in each set) were selected. The coatings to be tested were respectively applied with the coating of the present invention (prepared in Example 1) and with traditional natural lacquer, and an outdoor exposure comparison test was conducted.

[0079] The lacquer finishing process includes the following steps: (1) Body treatment: The surface of the red pine carved door and window body is sanded with 180 grit sandpaper along the wood grain until it is smooth and flat. The wood dust is blown away, and the surface is wiped with anhydrous ethanol cotton cloth to remove grease and dirt. It is then allowed to dry naturally for 2 hours. (2) Primer: The coating to be tested is applied to the surface of the substrate with a wet film thickness of 100 μm and dried in the shade for 18 hours at 25°C and 70% relative humidity; (3) Intermediate coating and decoration: Repeat step (2) twice. After each drying, lightly sand the paint surface with 800 grit sandpaper to remove the slight bumps. Then, paint the scroll pattern with vermilion lacquer on the paint surface after the base coating has cured. After the surface is dry, apply gold glue and apply gold leaf. Use a soft brush to lightly press and flatten the gold leaf. After drying for 24 hours, sweep away the excess gold leaf debris to form a gold-painted decoration. (4) Topcoat and polishing: The coating to be tested is applied to the surface of the decorative layer as topcoat with a wet film thickness of 80 μm. It is cured under the following conditions: 50℃, relative humidity 70%, curing for 24h. Then, it is smoothed with 2000-grit sandpaper dipped in water and polished with deerskin dipped in vegetable oil and fine tile ash.

[0080] Outdoor exposure test: Two sets of components were installed under the eaves of the building facade and exposed to a humid, sunny environment for 12 months, with the paint film condition observed monthly. At the same time, an artificial accelerated aging test (according to GB / T 1865-2009 "Artificial Climate Aging and Artificial Radiation Exposure to Filtered Xenon Arc Radiation for Paints and Varnishes") was conducted on the cut samples for 1000 hours.

[0081] Test results: After 12 months, the coating film of this invention remained intact, and the gold-painted pattern was complete and clear; the traditional natural lacquer control film showed multiple cracks and peeling, and could no longer maintain its decorative properties; after 1000 hours of artificial aging, the coating of this invention retained 84% of its gloss, while the traditional natural lacquer control film only retained 47%. The coating of this invention remained intact after 12 months of outdoor exposure, thanks to the durable waterproof effect of the hydrophobic modified compound, which blocks water penetration, and the double cross-linked network, which enhances the cohesive strength and anti-aging ability of the coating film.

[0082] Application Example 2: Demonstration of Decorative Effects of Lacquerware Craftsmanship—Application of Gilding and Inlaid Gilding Techniques in Wooden Carved Ornaments Six camphor wood ornaments of the same specifications were selected and randomly divided into three groups: Group A was decorated with the paint and gold-painting technique of Example 1 of the present invention, Group B was decorated with the paint and gold-painting technique of Example 2 of the present invention, and Group C was decorated with traditional natural lacquer as a control.

[0083] Group A: Gilding technique, the method and steps are the same as in application example 1.

[0084] Group B: Inlaid gold craftsmanship (1) Body treatment: The surface of the red pine carved door and window body is sanded with 180 grit sandpaper along the wood grain until it is smooth and flat. The wood dust is blown away, and the surface is wiped with anhydrous ethanol cotton cloth to remove grease and dirt. It is then allowed to dry naturally for 2 hours. (2) Primer: The coating to be tested is applied to the surface of the substrate with a wet film thickness of 100 μm and dried in the shade for 18 hours at 25°C and 70% relative humidity; (3) Intermediate coating and decoration: Repeat step (2) twice. After each drying, lightly sand the paint surface with 800-grit sandpaper to remove the slight protrusion. Then, use a cone needle (30° cone tip angle, 0.15mm diameter) to carve the dragon and phoenix pattern along the outline of the pattern on the paint surface after the base coating has cured. The carving depth is 0.3mm to form a V-shaped groove. After carving, apply gold glue evenly in the groove. When the gold glue is half dry, sprinkle gold powder (325 mesh, about 45μm particle size) into the groove. Press lightly with a soft cloth to make the gold powder fully fill it. After standing and drying for 24 hours, wipe the excess gold powder on the surface with a soft cloth. The gold powder in the groove is firmly retained due to the mechanical locking effect. (4) Topcoat and polishing: The coating to be tested is applied to the surface of the decorative layer as topcoat with a wet film thickness of 80 μm. It is cured under the following conditions: 50℃, relative humidity 70%, curing for 24h. Then, it is smoothed with 2000-grit sandpaper dipped in water and polished with deerskin dipped in vegetable oil and fine tile ash.

[0085] Evaluation of decorative effect: Group A: The edges of the gilded lines are sharp and there is no ink bleeding. The gold foil is firmly attached and there are no curling edges. Group B: The engraved edges are smooth and there are no chips. The gold powder is fully filled and does not fall off after 50 rubs. Group C: The control sample has slight ink bleeding and curling at the edges of the gilded lines. There are slight chips at the edges of the inlaid gold lines.

[0086] This invention's coating exhibits superior workability and final decorative effect compared to traditional raw lacquer in both gilding and inlay gilding techniques. In gilding, the surface smoothness and adhesion properties of this invention's coating prevent ink bleeding when drawing lines with vermilion lacquer, ensure uniform wetting and spreading of the gold glue, and guarantee firm adhesion of the gold leaf. This fundamentally solves the problem of poor adhesion of the gold glue or peeling of the gold leaf caused by the unstable viscosity of raw lacquer on-site. In inlay gilding, the dendritic polyamide-amine-tetraethyl orthosilicate double cross-linked network of this invention endows the paint film with higher hardness and toughness. When engraving, the edges of the lines are smooth and free of chipping. During polishing, wear in the inlay gilding area is minimized, maintaining the bright effect of the gold lines.

[0087] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0088] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A waterproof and fireproof coating for lacquering processes, characterized in that, The product comprises, by weight, 100 parts of natural lacquer, 8-22 parts of core-shell modified nano-fire retardant filler, 3-8 parts of hydrophobic modified compound, 5-12 parts of crosslinking agent, and 15-35 parts of diluent; the core of the core-shell modified nano-fire retardant filler is a composite core composed of nano-silica modified with γ-aminopropyltriethoxysilane and nano-aluminum hydroxide, wherein the mass ratio of nano-silica to nano-aluminum hydroxide is 1:(0.8-2.5); and the shell of the core-shell modified nano-fire retardant filler is a dendritic polyamide-amine shell layer coated by electrostatic induction self-assembly under pH 5.0-6.5 conditions.

2. The waterproof and fireproof coating for lacquering processes according to claim 1, characterized in that, The dendritic polyamide-amine shell accounts for 10%-30% of the total mass of the core-shell structure modified nano fireproof filler, and the shell thickness is 5-15 nm.

3. The waterproof and fireproof coating for lacquering processes according to claim 1, characterized in that, The γ-aminopropyltriethoxysilane accounts for 3%-8% of the total mass of the composite nucleus.

4. The waterproof and fireproof coating for lacquer finishing processes according to claim 1, characterized in that, The hydrophobic modified compound is a mixture of heptadecafluorodecyltrimethoxysilane and hydroxyl-terminated polydimethylsiloxane, with a mass ratio of heptadecafluorodecyltrimethoxysilane to hydroxyl-terminated polydimethylsiloxane of 1:(0.8-1.5).

5. The waterproof and fireproof coating for lacquering processes according to claim 2, characterized in that, The crosslinking agent is a mixture of dendritic polyamide-amine and tetraethyl orthosilicate, with a mass ratio of dendritic polyamide-amine to tetraethyl orthosilicate of 1:(1.2-2.5).

6. The waterproof and fireproof coating for lacquering processes according to claim 3, characterized in that, The diluent is one or more of ethanol, isopropanol, or ethyl acetate.

7. A method for preparing a waterproof and fireproof coating for lacquering processes according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Nano silica and nano aluminum hydroxide were mixed in proportion, and surface modified with γ-aminopropyltriethoxysilane. Then, dendritic polyamide-amine was added under pH 5.0-6.5 conditions for electrostatic self-assembly. After drying, core-shell structure modified nano fireproof filler was obtained. (2) Mix the hydrophobic modified compound with the diluent according to the ratio, and disperse by ultrasonication to obtain a hydrophobic pre-dispersion; (3) Mix the crosslinking agent with natural lacquer at 15-25℃ according to the ratio and stir for 10-25 min; raise the temperature to 35-45℃ and add the core-shell structure modified nano fireproof filler in 2-4 portions, with an interval of 5-15 min each time, and stir until uniform to obtain the mixture. (4) Add the hydrophobic pre-dispersion liquid to the mixture, stir at 35-50℃ for 20-40 minutes, cool to room temperature, let stand to degas, and obtain waterproof and fireproof coating.

8. The method for preparing a waterproof and fireproof coating for lacquering processes according to claim 7, characterized in that, The ultrasonic dispersion in step (2) is performed at a frequency of 40 kHz, a power of 200-300 W, and a time of 15-25 min.

9. The method for preparing a waterproof and fireproof coating for lacquering processes according to claim 7, characterized in that, After adjusting the pH to 5.0-6.5 as described in step (1), add dendritic polyamide-amine and stir at 20-30℃ for 15-30 min to carry out self-assembly. Then, centrifuge and dry under vacuum at 40-60℃ for 8-12 h.

10. A finishing process for a waterproof and fireproof coating according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Body treatment: The body to be modified is sanded with 80-400 grit sandpaper, cleaned and dried; (2) Primer: Apply waterproof and fireproof coating to the surface of the substrate, with a wet film thickness of 60-120μm, and allow it to dry naturally for 12-24 hours at 20-30℃ and 60%-85% relative humidity; (3) Intermediate coating and decoration: Repeat step (2) 1-3 times, sanding after each drying, and then decorate the paint surface after the base coat or intermediate coat has cured; (4) Topcoat and polishing: Apply waterproof and fireproof coating as topcoat to the surface of the decorative layer. The wet film thickness is 60-100μm. Curing is carried out under any of the following conditions: ① 40-60℃, relative humidity 60%-85%, curing for 12-48h; or ② 20-30℃, relative humidity 60%-85%, curing for 48-120h. Then, sanding, polishing and cleaning are carried out in sequence.