Three-stage modified coating process for odorless, aging-resistant and crack-resistant waterborne paint coated solid wood board

Abstract

The present application relates to the technical field of digital coating of solid wood, and in particular to a three-stage modified coating process for an odorless, aging-resistant and crack-resistant waterborne paint coated solid wood board. The process comprises the following steps: stage S1: primer composite coating, which comprises the application of four primer coating layers; stage S2: digital grain composite coating, which comprises the application of three intermediate coating layers; and stage S3: modified composite coating of waterborne paint finish coating layers, which comprises the application of four finish coating layers. By means of the three-stage digital coating process, the present application overcomes the problems of poor aging resistance and crack resistance, poor odorless effect, and failure to ensure the stability and consistency of optimal effect of solid wood sense in surface-coated solid wood boards, and also overcomes the problems that painted surfaces of surface-coated solid wood boards applying pure UV coating systems do not have a high-end sense, and surface effect, surface performance and environmentally-friendly and odorless performance are not high-end enough.

Description

A three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards Technical Field

[0001] This application relates to the field of digital coating technology for solid wood, and in particular to a three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards. Background Technology

[0002] Solid wood lacquered panels are the primary material for dark-colored, precious hardwood furniture and high-end custom furniture. Traditional solid wood lacquered panels are made from engineered wood panels with a fine, high-quality decorative veneer, which are then finished with wood lacquer coatings. The main function of the fine, high-quality decorative veneer layer is to provide decorative textures, grains, patterns, and colors to the surface of the solid wood lacquered panel. The main function of the wood lacquer coating is to provide or further enhance, optimize, and upgrade the surface physical and chemical properties of the solid wood lacquered panel (including but not limited to: film hardness, scratch resistance, anti-scratch properties, resistance to contaminant corrosion, crack resistance, aging resistance, yellowing resistance, and other protective or durable properties) and surface decorative properties (including but not limited to: gloss, color, clarity, transparency, naturalness, three-dimensionality, holographic effect, skin-like feel, and other visual and tactile decorative properties). Technical issues

[0003] While the aforementioned traditional solid wood lacquered panels possess many excellent features and advantages, they also present several challenges and pain points that urgently require research and solutions.

[0004] The first problem is that the finish of traditional solid wood lacquer panels relies excessively on traditional solvent-based wood coatings [including but not limited to polyurethane wood coatings (PU lacquer), alkyd wood coatings (AC lacquer), nitrocellulose wood coatings (NC lacquer), etc.]. However, traditional solvent-based wood coatings perform poorly in terms of odor, limits on harmful substances such as VOCs, and aging resistance. As a result, the health, safety, and environmental performance of these products cannot meet people's strong demand for a healthy, environmentally friendly, and better life, especially the requirements for odor-free, formaldehyde-free, and ultra-low VOCs release, as well as people's strong demand for non-toxic, harmless, and odorless products that can be installed and moved into immediately without the need for long-term ventilation or long-term storage to remove odors.

[0005] The second problem is that the solid wood feel of traditional solid wood lacquered panels relies excessively on premium decorative veneer layers. Without these layers, it's impossible to achieve the decorative effects such as textures, grains, patterns, and colors. However, these premium veneer layers are overly dependent on precious natural wood resources and the handcrafted production processes of premium veneer processing and engineered wood veneer industries. This makes traditional solid wood lacquered panels not only difficult to mass-produce industrially, resulting in extremely high production costs, but also unable to meet the current demand for personalized customization and rapid design and production delivery services.

[0006] The third problem is that the solid wood feel and veneer texture of traditional solid wood lacquer panels rely on the surface decorative effects (texture, grain, and pattern / color) obtained from precious and high-quality decorative thin wood veneers. Because these materials come from different logs or timbers, and from different origins, varieties, ages, and trunk sections, there are natural and inherent differences. This can only guarantee a similar decorative effect, but not an identical one. It is difficult to guarantee the consistency and stability of the surface decorative effect, and there are often obvious deviations in the surface decorative effects such as texture, grain, color, and pattern. Therefore, it is difficult to meet the production needs of large-scale industrialization, mass production, and strict standardization, as well as the market demand and the demand for the ultimate aesthetics in home decoration.

[0007] Chinese patent application number 202310144967.6 provides a finishing process for CNC color matching of 3D perforated wood grain paint on the surface of engineered wood panels, which solves the above-mentioned problems to a certain extent. However, the primary technical feature of this patent is that it uses a composite coating system of pure UV wood coatings instead of a composite coating system of solvent-based wood coatings; another significant feature of this patent is that it uses the surface film-pressed texture or printed texture of 3D texture-shaped UV topcoat coatings instead of the natural texture of decorative thin wood veneer layers, and uses a UV ink color composite coating system instead of the natural texture and decorative color patterns of decorative thin wood veneer layers. However, while solving the above problems, the above patent and its solution also bring new problems, namely:

[0008] (1) Insufficient adhesion and performance of coating interface: In the traditional water-based paint topcoat process, the physical bonding between the coatings depends on the surface roughness and lacks chemical activity regulation, resulting in unstable interlayer adhesion and easy peeling. Especially in the process of texture shaping by film pressing roller coating, the coating is prone to delamination due to insufficient interfacial bonding when it is deformed under stress, which affects the overall weather resistance.

[0009] (2) The surface finish of this coating process has obvious limitations. The coating effect of the closed paint surface has a certain degree of haziness, insufficient transparency and clarity. The effect of the open paint surface has a certain degree of texture deviation, insufficient synchronization, and appearance quality defects such as impurities and bright marks in the concave texture. As a result, the coating effect can only reach the simulation level, but cannot achieve the ultimate effect that surpasses the master version.

[0010] (3) The paint surface of pure UV roller coating is not high-end enough: it cannot achieve the high-end effect of being extremely delicate, warm and high-end from a distance, up close, microscopically and macroscopically, visually and tactilely, and harmoniously integrating real naturalness and design.

[0011] (4) The real wood feel effect of pure UV ink color coating + pure UV-3D simulation texture coating is not realistic and natural enough: the clarity, synchronization, vividness and realism of the texture and grain are not enough, and the effect of seeing the wood without seeing the paint is not achieved. In particular, the open type of paint surface has flaws and cannot achieve the ultimate visual and tactile effect.

[0012] (5) Insufficient resistance to aging and cracking: Pure UV coatings are relatively hard and brittle, and have poor resistance to yellowing, oxidation, and cracking. In order to balance the curing efficiency of UV radiation, large doses of UV absorbers cannot be used. When the UV coating, which is easily exposed to light, heat and oxidation, is the outermost layer and is directly exposed to light, oxygen, heat, moisture and other external environments, the UV paint coating will be easily oxidized and decomposed or cracked by light and heat radiation, producing various color groups and functional groups, resulting in yellowing, blackening and discoloration of the coating, aging and cracking, which affects the decorative effect.

[0013] (6) Insufficient odor neutralization effect: The pure UV system composite coating and its UV-3D topcoat curing coating are directly exposed on the outermost layer of the board surface, causing residual low-boiling-point VOCs such as photoinitiators to volatilize and produce a slight odor. This cannot meet the requirements of applications such as wardrobes and cabinets, where there are enclosed spaces or a large usage rate of the board, making it easy for odor substances to accumulate and become noticeable as the amount of board used and the sealing time increases. It is difficult for the odor level of the product surface coating to consistently reach the ≤1 level of odor neutralization, and the VOCs release is also difficult to consistently reach the ultra-low release level required by the green product standard (TVOC release ≤0.100mg / m³). 3 ).

[0014] (7) There are shortcomings in the synergistic effect between yellowing resistance and crack resistance: Due to its hard and brittle nature, pure UV coatings are prone to oxidative decomposition under the action of light, oxygen and heat cycles, producing chromogenic groups that cause yellowing; at the same time, stress concentration inside the coating is prone to microcracks, especially in areas with complex textures, where the risk of crack propagation is higher. Existing UV absorbers are limited by UV curing efficiency, making it difficult to increase the amount added, and there is a lack of means to synergistically regulate the toughness and oxidation resistance of the coating. Technical solutions

[0015] This application provides a three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards to solve the problems mentioned in the background art.

[0016] To address the above problems, this application provides a three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards, which includes the following steps:

[0017] S1 Section: Primer Composite Coating:

[0018] S101, First base coat coating: After sanding and dust removal of the substrate surface, apply UV odor-free, yellowing-resistant, high-adhesion clear primer and adhesive putty clear primer in sequence by roller coating.

[0019] S102, Application of the second primer coating: Apply a UV-free, odor-free, yellowing-resistant, white solid-color primer by roller coating over the first primer coating;

[0020] S103, Application of the third base coat: Apply a UV-free, odor-free, yellowing-resistant, color-correcting solid-color primer by roller coating over the second base coat.

[0021] S104, Fourth base coat coating: Apply UV-free, odor-free, yellowing-resistant, color-correcting solid-color base coat by roller coating over the third base coat.

[0022] S2 Section: Digitalized Color Composite Coating:

[0023] S201, the first intermediate coating: a UV-resistant, odor-free, yellowing-resistant, high-adhesion clear primer is applied by roller over the fourth base coat of S104.

[0024] S202, Coating of the second intermediate coating layer: UV-resistant, odor-free, high colorfastness yellow, magenta, cyan, and black solid color inks are sprayed onto the first intermediate coating layer respectively.

[0025] S203, the application of the third intermediate coating: apply a UV-free, odor-free, yellowing-resistant, sand-finish primer or a hardened primer by roller coating over the second intermediate coating.

[0026] S3 Section: Water-based paint topcoat modified composite coating:

[0027] S301, Coating of the first topcoat layer: Spray a pretreatment liquid on the third intermediate coat layer, dry at 40~50℃ for 10~15 minutes, and then roll-coat a UV-clean, odor-free, yellowing-resistant, high-adhesion clear primer.

[0028] S302, second topcoat coating: spray pretreatment liquid on top of the first topcoat, dry at 40~50℃ for 10~15min, then apply UV odor-free and yellowing-resistant synchronous textured clear topcoat with film roller.

[0029] S303, the coating of the third topcoat: spray the surface modification liquid on the second topcoat, dry at 55~65℃ for 6~10 minutes, roll the water-based UV odor-free and yellowing-resistant color-correcting primer, and then heat and dehumidify and dry at 80~100℃ for 2 minutes.

[0030] S304, fourth topcoat coating: Spray surface modifier on top of the third topcoat, dry at 55~65℃ for 6~10 minutes, then spray water-based odor-free and yellowing-resistant topcoat, first dry the surface layer in an infrared drying tunnel at 35~45℃ for 10 minutes, and then dry the inner layer in a heated and dehumidified vertical drying oven at 45~60℃ for 90~120 minutes.

[0031] The spraying amount of the pretreatment liquid is 4~6 g / m³. 2 The preparation method is as follows: lithium stearate is dissolved in anhydrous ethanol, then 50 nm silver peroxide is added, and the mixture is ultrasonically dispersed for 30 min to obtain a pretreated solution. The concentration of lithium stearate is 0.2~0.4 wt%, and the concentration of silver peroxide is 0.1 wt%.

[0032] The spraying amount of the surface modification liquid is 6~8 g / m². 2 The preparation method is as follows: on the basis of the pretreatment liquid, 1 wt% of modified aerogel is added to the pretreatment liquid, and then 0.3% of diphenyl phosphonate is added. After ultrasonic dispersion for 25 min, the surface modified liquid is obtained.

[0033] The modified aerogel is prepared by dissolving γ-aminopropyltriethoxysilane in anhydrous ethanol at a mass ratio of 1:20, adding aerogel and tannic acid at a mass ratio of 10:1, dispersing at 500 r / min for 5 min, stirring at 3000 r / min for 30 min, and then distilling under reduced pressure to obtain the modified aerogel. The mass ratio of the aerogel to anhydrous ethanol is 1:10.

[0034] Preferably, in S1, the coating speed of the primer composite coating is 16~18m / min;

[0035] In S2, the coating speed of digital color composite coating is 24~26m / min;

[0036] In S3, the coating speed of the water-based paint topcoat modified composite coating is 5~6m / min.

[0037] Preferably, the substrate is a hard, dense, crack-resistant, closed-type real wood veneer formaldehyde-free and odorless engineered wood panel.

[0038] Preferably, in section S1, among the following: UV odorless, yellowing-resistant, high-adhesion clear primer, adhesive putty clear primer, UV odorless, yellowing-resistant white solid-color primer, UV odorless, yellowing-resistant color-correcting solid-color primer, and UV odorless, yellowing-resistant color-correcting solid-color primer:

[0039] The long-lasting anti-yellowing multifunctional additive used is rutile type pigment-grade and micron-sized ultrafine powder titanium dioxide in a single crystal form, with a particle size of 100~400nm. Calculated by mass, the amount of the long-lasting anti-yellowing multifunctional additive added accounts for 5~8% of the mass of each of the above primers.

[0040] The UV resin used is an aliphatic non-aromatic polyurethane acrylate resin, silicone-modified or polyurethane-modified epoxy acrylate resin, pure acrylic resin, or a mixture thereof. The amount of UV resin added accounts for 46-65% of the mass of each of the above primers, calculated by mass.

[0041] The UV-active monomers used are TMPTA trimethylolpropane acrylate, TPGDA tripropylene glycol acrylate, DPGDA dipropylene glycol diacrylate, or a mixture thereof. The amount of UV-active monomers added accounts for 25-45% of the mass of each of the above primers, calculated by weight.

[0042] The photoinitiator used is TPO 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, BMF methyl benzoylformate, ITX isopropylthioxanthone, or a mixture thereof. The amount of photoinitiator added accounts for 2 to 6% of the mass of each of the above primers, calculated by mass.

[0043] Preferably, among UV-cured, low-odor, high-color-resistance solid inks in yellow, magenta, cyan, and black:

[0044] The long-lasting, yellowing-resistant, multifunctional additive used is rutile-type ultrafine nano-titanium dioxide powder in a single crystal form, with a particle size of 10~100nm. Calculated by mass, the amount of the long-lasting, yellowing-resistant, multifunctional additive added accounts for 0.5~5% of the mass of the aforementioned UV-resistant, odor-free, high-color-resistance yellow, magenta, cyan, and black solid color inks.

[0045] The UV resin used is an aliphatic non-aromatic polyurethane acrylate resin, fatty acid modified or polyurethane modified or silicone modified epoxy acrylate resin, pure acrylic resin, or a mixture thereof. Calculated by mass, the amount of UV resin added accounts for 30-60% of the mass of UV odorless high colorfastness yellow, magenta, cyan, and black solid color inks.

[0046] The photoinitiator used is TPO 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, BMF methyl benzoylformate, ITX isopropylthioxanthone, or a mixture thereof. The amount of photoinitiator added accounts for 2 to 5% of the mass of each of the above primers, calculated by mass.

[0047] Preferably, in fatty acid-modified, polyurethane-modified, or silicone-modified epoxy acrylate resins:

[0048] The preparation method of fatty acid modified epoxy acrylic resin includes the following steps:

[0049] 100 parts of bisphenol A epoxy resin were mixed with 0.1 parts of hydroquinone and melted at 90°C. Then, 30 parts of oleic acid were added under stirring. The mixture was heated to 110°C and reacted for 2 hours. The mixture was then cooled to 80°C and 25 parts of acrylic acid and 1 part of triethylamine were added dropwise. The mixture was then reacted at 90°C for 3 hours to complete the preparation.

[0050] The preparation method of polyurethane-modified epoxy acrylic resin includes the following steps:

[0051] Add 20 parts of hydroxyl-terminated polyurethane prepolymer and 0.2 parts of dibutyltin dilaurate to 100 parts of epoxy acrylate resin heated at 60°C. After reacting for 1.5 hours, add 3 parts of 1-hydroxy-cyclohexyl-phenyl ketone and 10 parts of tripropylene glycol diacrylate, and stir until homogeneous.

[0052] The preparation method of silicone-modified epoxy acrylate resin includes the following steps:

[0053] Add 10 parts of γ-methacryloxypropyltrimethoxysilane to 100 parts of epoxy acrylate resin heated at 80°C, cool to 50°C, then add 2 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 10 parts of isooctyl acrylate, and stir until homogeneous.

[0054] Preferably, in S302, the UV-resistant, odor-neutralizing, yellowing-resistant, texture-enhancing clear topcoat, by weight, comprises 20-25 parts of polyurethane acrylic resin; 25-40 parts of epoxy acrylic resin; 30-40 parts of an equal-proportion mixture of DPGDA dipropylene glycol diacrylate, TPGDA tripropylene glycol acrylate, TMPTA trimethylolpropane acrylate, and HEMA hydroxyethyl methacrylate; 4-7 parts of an equal-proportion mixture of MBF, TPO, and ITX; 0.2-0.4 parts of a defoaming polymer solution; and 0.4-0.6 parts of a polysiloxane-ether copolymer solution.

[0055] Preferably, in S304, the water-based odor-free, yellowing-resistant clear topcoat comprises, by weight parts:

[0056] 100 parts of a composition of waterborne acrylic modified polyurethane resin and waterborne polyurethane dispersion;

[0057] 5-15 parts of curing agent;

[0058] 10-20 parts diluent;

[0059] 0.2-2.0 parts of ultraviolet light absorber, anti-aging and antioxidant sunscreen additives;

[0060] VOCs purifying and deodorizing agent: 3.0~6.0 parts;

[0061] 1.0 to 3.0 parts of additives.

[0062] The curing agent is a combination of hydrophilic modified aliphatic polyisocyanate and hydrophilic modified alicyclic polyisocyanate;

[0063] The diluent is purified water;

[0064] The ultraviolet light absorber, anti-aging and antioxidant sunscreen additive is a composition of 2-hydroxy-4-methoxybenzophenone, 4-hydroxy-2,2,6,6-tetramethylpiperidine, hexyl diethylaminohydroxybenzoylbenzoate, ethylhexyl methoxycinnamate, rutile fumed nano titanium dioxide, and nano zinc dioxide.

[0065] The VOCs purifying and deodorizing agent is a composition of nano-silica, nano-photocatalyst, chitosan, and ethylene urea in equal proportions.

[0066] Preferably, in S101, the coating amount of the UV-resistant, odor-neutralizing, yellowing-resistant, high-adhesion clear primer is 15~25 g / m². 2 The application rate of the putty primer is 25~35g / m². 2 The UVA energy value of UV radiation is 200~400 mJ / cm. 2 UVV energy value is 300~600mJ / cm 2 ;

[0067] In both S102 and S103, the primer coating amount is 20~30g / m². 2 The UVA energy value of UV radiation is 150~350 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 ;

[0068] In S104, the primer coating amount is 20~30g / m². 2 The UVA energy value of UV radiation is 250~400 mJ / cm². 2 UVV energy value is 400~600mJ / cm 2 ;

[0069] In S201, the primer coating amount is 10~20g / m². 2 The energy value of UVA radiation is 150~300 mJ / cm. 2 UVV energy value is 200~400mJ / cm 2 ;

[0070] In step S202, the ink coating amount is 1~10g / m². 2 The UVA energy value of UV radiation is 200~400 mJ / cm. 2 UVV energy value is 300~600mJ / cm 2 ;

[0071] In the S203, the primer coating amount is 15~25g / m². 2 The energy value of UVA in UV radiation is 300~500 mJ / cm. 2 UVV energy value is 400~800 mJ / cm 2 ;

[0072] In S301, the primer coating amount is 15~25g / m². 2 The energy value of UVA radiation is 150~300 mJ / cm. 2 UVV energy value is 200~400mJ / cm 2 ;

[0073] In S302, the topcoat application rate is 150~250g / m². 2 The energy value of UVA radiation is 300~400 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 ;

[0074] In the S303, the primer coating amount is 30~45g / m². 2 The energy value of UVA radiation is 300~400 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 . Beneficial effects

[0075] The beneficial effects of the technical solution provided in this application include:

[0076] (1) Add pretreatment liquid and surface modification liquid to the water-based paint topcoat. The long-chain structure of lithium stearate is embedded between the UV resin molecular chains, which effectively reduces the brittleness of the coating. Combined with the stress dispersion of texture shaping during subsequent roller coating, it reduces the generation of microcracks and improves the unstable interlayer adhesion and the delamination problem during texture shaping. The aerogel in the surface modification liquid has a porous structure, which buffers the stress of S304 two-stage drying. The silver peroxide and diphenyl phosphonate in it work synergistically with the UV absorber in the S304 topcoat to improve the yellowing resistance and achieve synergistic regulation of crack resistance and yellowing resistance.

[0077] (2) The application of odor-free and aging-resistant modified coatings and digital water-based paint coating technology has solved problems such as insufficient high-end feel of the paint surface, insufficient realism and naturalness of the wood texture, and poor odor-free, aging-resistant and crack-resistant performance. Odor-free and aging-resistant additives (5%~20% rutile micronized titanium dioxide) and simulation enhancers (0.5~5.0% rutile vapor-phase nano-titanium dioxide) are applied to the coatings and inks; the "ultraviolet light absorption and shielding effect" of micronized titanium dioxide is used to improve the odor-free and aging-resistant performance of the coating; the "angle-dependent color and light refraction effect" of nano-titanium dioxide is used to significantly improve the printing clarity, simulation, vividness and real wood texture of the ink spray printing pattern coating; the texture modeling synchronization process is used to improve the synchronization of UV-3D topcoat texture; the modified water-based paint process (with the addition of simulation enhancers, odor-free purification functional additives and aging-resistant additives) significantly improves the high-end feel of the paint surface, the real wood texture and the odor-free, aging-resistant and crack-resistant performance.

[0078] (3) The technical requirements for the substrate veneer layer have been improved, making the subsequent coating process simpler and more cost-effective. By using a closed-type crack-resistant substrate and an odor-free, aging-resistant, and crack-resistant coating process, a variety of unique paint effects, such as closed-type, open-type, semi-open-type, and customized special effects, can be flexibly obtained as needed. In particular, the surface veneer layer is preferably made of fast-growing plantation poplar natural color ordinary engineered wood veneer rather than precious superior natural wood veneer, and does not involve endangered animal and plant species or controlled timber, which can avoid technical barriers and tariff barriers for export to European and American markets.

[0079] (4) The coating process of the primer composite coating is simplified, and multiple processes such as the surface wire drawing and hole-revealing treatment of the substrate, UV roller coating of ordinary putty, and sanding primer are omitted and saved. While achieving significant improvement in primer effect and odor-free, aging-resistant and crack-resistant performance, significant cost reduction, efficiency improvement and value-added economic effects can also be obtained.

[0080] (5) Replacing the pure UV coating system with a "mixed coating system of UV primer + UV intermediate coat + water-based topcoat" is not only an upgrade of the traditional UV coating process, but also a digital improvement and innovative breakthrough of the traditional water-based paint coating process. It not only solves the problem of poor aging resistance such as yellowing, oxidation, and cracking resistance of pure UV coatings, but also overcomes the problem that pure UV coating systems cannot add large doses of UV absorbers in order to take into account the efficiency of light radiation curing. When the UV coating, which is easily exposed to light, heat and photo-oxidation, is the outermost layer and is directly exposed to light, oxygen, heat, moisture and other external environments, the UV topcoat coating will be easily oxidized and decomposed or photo-thermal radiation cracked, producing various color groups and functional groups, resulting in yellowing, blackening and discoloration of the coating color, aging and cracking, which affects the surface decoration effect; it also makes full use of the flexibility of water-based paint coatings, solves the problems of high hardness, poor aging resistance and easy cracking and chipping of pure UV coatings, and realizes high performance and high cost performance (digitalization) of water-based paint coating.

[0081] (6) The invention replaces the pure UV coating system with a "hybrid coating system of UV primer + UV intermediate coat + water-based topcoat," overcoming the problem that the pure UV composite coating and its UV-3D topcoat, being directly exposed to the outermost layer of the board surface, can release residual low-boiling-point VOCs such as photoinitiators, resulting in a slight odor. This is unacceptable for applications such as wardrobes and cabinets where enclosed spaces or high board usage can easily lead to the accumulation of odorous substances with increasing board usage and sealing time, resulting in a noticeable odor. The product of this invention has a surface coating with an odor level that can stably reach ≤1 (neutral odor level), and the VOC release can stably reach the ultra-low release level required by the green product standard (TVOC release ≤0.100mg / m³). 3 It contains no formaldehyde and has the special effect of purifying the air quality in the space where the product is used.

[0082] (7) The outermost coating layer has been improved from roller-coated UV topcoat to spray-coated water-based paint, which is not only healthier and odorless, but also has a more delicate and high-end surface texture. The added water-based UV color-correcting clear varnish and spray-coated water-based paint top layer can enhance the color correction effect and transparency of the top layer coating. There are no limitations of conventional UV-3D coating process. The effect of closed paint surface does not have problems such as haziness, insufficient transparency and clarity. The effect of open paint surface does not have defects in appearance such as texture deviation, insufficient synchronization, and recessed texture impurities and bright marks. The coating effect can far exceed the simulation level, can exceed the master version effect, and can achieve the ultimate superior effect.

[0083] (8) This invention pioneers a new three-stage coating process, which scientifically meets the process characteristics of each functional coating (avoiding direct contact between water-based paint and substrate, which may lead to the substrate absorbing moisture and causing risks such as swelling, cracking, and deformation), enabling each coating to obtain a suitable curing effect, ensuring that the performance of each coating meets the technical requirements, achieving the effect of seeing the wood but not the paint, with a strong solid wood feel and a relatively weak paint feel, and avoiding residual odor or performance reduction due to incomplete coating curing; it can also maximize the operating efficiency of each stage, ensuring the optimal output, efficiency, and cost, and achieving a better process effect of energy saving, consumption reduction, and efficiency improvement. Attached Figure Description

[0084] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0085] Figure 1 is a production process flow diagram of the three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards provided in this application. The best embodiment of the present invention

[0086] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0087] Referring to Figure 1, this application provides a three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards, which includes the following steps:

[0088] Section S1: Primer composite coating, specifically including the application of 4 primer coats, with a coating speed of 16~18m / min.

[0089] S101, Application of the first primer coating: After sanding and dust removal of the substrate surface, apply a UV-resistant, odor-free, high-adhesion, non-yellowing primer and an adhesive putty primer in sequence by roller coating. Then, subject the substrate to UV radiation and allow it to dry and cure to 70% of its original curing level. No further curing is required. Finally, use a 400# sanding belt to finely sand the paint film surface. The application rate of the UV-resistant, odor-free, high-adhesion primer is 15~25 g / m². 2 The application rate of the putty primer is 25~35g / m². 2 The UVA energy value of UV radiation is 200~400 mJ / cm. 2 UVV energy value is 300~600mJ / cm 2 .

[0090] S102, Application of the second primer coating: Apply a UV-cured, odor-free, yellowing-resistant, white solid-color primer by roller coating over the first primer coating, and then subject it to UV radiation for drying and curing to 50% curing degree. The primer coating amount is 20~30g / m². 2 The UVA energy value of UV radiation is 150~350 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 ;

[0091] S103, Application of the third primer coating: Apply a UV-cured, odor-free, yellowing-resistant, color-correcting primer by roller coating over the second primer coating, and then subject it to UV radiation for drying and curing to 50% completion. The primer application rate is 20-30 g / m². 2 The UVA energy value of UV radiation is 150~350 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 ;

[0092] S104, Fourth base coat application: Apply a UV-cured, odor-free, yellowing-resistant, color-correcting base coat by roller over the third base coat, and then subject it to UV radiation. After drying and curing to 70% of the desired curing degree, store it for at least 24 hours to allow the odor to dissipate. Finally, use a 400# belt abrasive to finely sand the paint film surface. The base coat application rate is 20-30 g / m². 2 The UVA energy value of UV radiation is 250~400 mJ / cm². 2 UVV energy value is 400~600mJ / cm 2 ;

[0093] Section S2: Digital color composite coating, specifically including the coating of three intermediate coats, with a coating speed of 24~26m / min.

[0094] S201, First Intermediate Coating: A UV-curing, odor-free, yellowing-resistant, high-adhesion clear primer is applied by roller over the fourth primer coating (S104), followed by UV radiation and drying / curing to 50% completion. The primer application rate is 10-20 g / m². 2 The energy value of UVA radiation is 150~300 mJ / cm. 2 UV energy value is 200~400mJ / cm 2 ;

[0095] S202, Second intermediate coating: UV-cured, odor-free, high-color-resistance yellow, magenta, cyan, and black solid color inks are sprayed onto the first intermediate coating and then subjected to UV radiation for drying and curing to approximately 50% curing degree. The ink coating amount for each layer is 1~10 g / m². 2 (The specific ink consumption depends on the pattern and color being printed.) The actual coating amount varies slightly depending on the depth of the pattern's color. The UVA energy value of UV light radiation is 200~400mJ / cm². 2 UVV energy value is 300~600mJ / cm 2 ;

[0096] S203, Application of the third intermediate coating: Apply a UV-cured, odor-free, yellowing-resistant, sand-finish primer or a hardened primer by roller coating over the second intermediate coating. After UV irradiation and drying to 70% curing, allow it to stand for at least 12 hours to allow the odor to dissipate. Then, use a 400-600# belt abrasive to finely sand the paint film surface. The primer application rate is 15-25 g / m². 2 In UV radiation, the energy value of UVA is 300~500 mJ / cm. 2 UVV energy value is 400~800 mJ / cm 2 ;

[0097] S3 Section: Water-based paint topcoat modification composite coating, specifically including the application of 4 topcoat layers, with a coating speed of 5~6 m / min:

[0098] S301, First Topcoat Coating: A pretreatment liquid is sprayed over the third intermediate coat. After drying at 40-50℃ for 10-15 minutes, a UV-cured, odor-free, yellowing-resistant, high-adhesion clear primer is applied by roller. Then, UV light is applied, and the primer is dried and cured to 50% of its original curing level. The amount of pretreatment liquid sprayed is 4-6 g / m². 2 The primer application rate is 15~25g / m². 2The energy value of UVA radiation is 150~300 mJ / cm. 2 UVV energy value is 200~400mJ / cm 2 ;

[0099] S302, Second Topcoat Application: A pretreatment liquid is sprayed over the first topcoat. After drying at 40-50℃ for 10-15 minutes, a UV-cured, odor-free, yellowing-resistant, texture-enhancing clear topcoat is applied using a film-pressing roller and then subjected to UV radiation for drying and curing to 90% completion. Finally, the paint film surface is finely sanded using a 600# belt abrasive. The amount of pretreatment liquid sprayed is 4-6 g / m². 2 The topcoat application rate is 150~250g / m². 2 The energy value of UVA radiation is 300~400 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 ;

[0100] Furthermore, the four edge lines of the decorative surface where the second coating layer is located need to be ground (the grinding width should be ≤0.5mm).

[0101] S303, Third Topcoat Application: A surface modifier is sprayed over the second topcoat. After drying at 55-65℃ for 6-10 minutes, a water-based UV-cured, odor-neutralizing, yellowing-resistant color-correcting primer is applied by roller. Then, the mixture is heated and dehumidified at 80-100℃ for 2 minutes, followed by UV radiation drying and curing to 70% of the desired curing degree. The surface modifier application rate is 6-8 g / m². 2 The primer application rate is 30~45g / m². 2 The energy value of UVA radiation is 300~400 mJ / cm. 2 UVV energy value is 400~600mJ / cm 2 ;

[0102] S304, fourth topcoat application: A surface modifier is sprayed over the third topcoat and dried at 55-65℃ for 6-10 minutes. Then, a water-based, odor-free, yellowing-resistant clear topcoat is sprayed. The surface layer is first dried in an infrared drying tunnel at 35-45℃ for 10 minutes, followed by inner-layer drying in a heated and dehumidified vertical drying oven at 45-60℃ for 90-120 minutes. After drying and curing to over 90% of the required degree, it is stored for at least 24 hours to complete the three-stage digital coating process. The surface modifier spraying amount is 6-8 g / m². 2 The application rate of the clear topcoat is 60~80g / m². 2 .

[0103] In some embodiments, in S101, S201, and S301, the UV-resistant, odor-neutralizing, yellowing-resistant, high-adhesion clear primer comprises the following components by weight:

[0104] The composition includes: 20-25 parts epoxy acrylate resin, 15-20 parts polyester acrylate resin, 10-15 parts amino acrylate resin, 8-10 parts dipropylene glycol diacrylate, 12-15 parts tripropylene glycol diacrylate, 10-15 parts trimethylolpropane triacrylate, 3-4 parts 2-hydroxy-2-methyl-1-phenylpropanone, 3-4 parts 1-hydroxycyclohexylphenyl ketone, 5-10 parts nano silica, 5-10 parts nano titanium dioxide, 0.01-1 part adhesion promoter, 0.01-1 part dispersant, 0.01-1 part wetting agent, 0.01-1 part defoamer, 0.01-1 part cosolvent, and 0.01-1 part anti-settling agent.

[0105] In some embodiments, the coating speed of the primer composite coating in section S1 is 16~18m / min;

[0106] In section S2, the coating speed of digital color composite coating is 24~26m / min;

[0107] In section S3, the coating speed for water-based paint topcoat modified composite coating is 5~6m / min.

[0108] In some embodiments, the substrate is a hard, dense, crack-resistant, closed-type real wood veneer formaldehyde-free and odorless engineered wood panel.

[0109] Furthermore, the substrate should preferably be an odorless, formaldehyde-free engineered wood substrate with an odor level ≤ 1. Specifically, it can be further preferred to use plywood or particleboard with wood veneer made entirely of eucalyptus or poplar wood using Three Trees Green Core formaldehyde-free glue or MDI formaldehyde-free glue. Formaldehyde-containing plywood and particleboard made of mixed wood, recycled wood, or wood species with obvious odor characteristics such as pine, cypress, camphor, cedar, and toon should not be used.

[0110] Secondly, the wood veneer plywood or wood veneer particleboard selected as the closed-type substrate for the aforementioned odorless, formaldehyde-free, and aging-resistant digital solid wood water-based paint board uses high-grade wood veneer with standardized surface conditions (no color difference, no missing fibers, no black lines, or other appearance defects) and a dense and compact type (density controlled between 0.60 and 0.70 g / cm³). 3、(Too low density results in insufficient hardness, while too high density results in insufficient flexibility and crack resistance.) This involves using a high-grade, crack-resistant, and aging-resistant original color poplar veneer, reconstituted and laminated, fine-grained, closed-cell (no wood eyes or pores) thin veneer. The veneer enhances the tactile and manual feel of the board by utilizing the natural wood texture of the substrate veneer. The high density, hardness, and crack resistance of the substrate veneer allow for a reduction in the hardness requirements of the finishing coating. This enables the use of aliphatic resins with a more flexible molecular structure that does not contain benzene or aromatic rings, thereby improving the finishing coating's aging resistance, crack resistance, antioxidant and anti-decomposition stability, and odor neutralization.

[0111] In some embodiments, in S101, the UV-resistant, odor-neutralizing, yellowing-resistant adhesive putty primer comprises the following components by weight:

[0112] 25-30 parts epoxy acrylate resin, 25-30 parts amino acrylate resin, 8-10 parts dipropylene glycol diacrylate, 12-15 parts tripropylene glycol diacrylate, 10-15 parts trimethylolpropane triacrylate, 3-4 parts 2-hydroxy-2-methyl-1-phenylpropanone, 3-4 parts 1-hydroxycyclohexylphenyl ketone, 5-10 parts lithopone, 5-10 parts talc, 5-10 parts nano silica, 5-10 parts nano titanium dioxide, 0.01-1 part adhesion promoter, 0.01-1 part dispersant, 0.01-1 part wetting agent, 0.01-1 part defoamer, 0.01-1 part cosolvent, and 0.01-1 part antisettling agent.

[0113] It should be noted that in S101, the adhesion promoter is silane coupling agent KH-570, the dispersant is BYK-163, the wetting agent is BASF EFKA-3600, the defoamer is Efka EFKA-2722, the cosolvent is propylene glycol methyl ether acetate (PMA), and the anti-settling agent is fumed silica.

[0114] In some embodiments, in S102, the UV-resistant, odor-neutralizing, yellowing-resistant, white solid-color primer comprises the following components by weight:

[0115] 5-20 parts of long-lasting anti-yellowing multifunctional additive, 50-70 parts of long-lasting odor-free anti-yellowing UV resin (the molecular structure does not contain aromatic rings and their double bonds, has good transparency and is not easy to break bonds and turn yellow under UV irradiation, and has good color retention, gloss retention and heat and weather resistance), 20-40 parts of UV active monomer, and 2-6 parts of photoinitiator.

[0116] The UV-resistant, odor-neutralizing, yellowing-resistant, color-correcting primers used in S103 and S104 comprise the following components by weight:

[0117] 5-20 parts of long-lasting, yellowing-resistant, multifunctional additive; 50-70 parts of long-lasting, odor-neutralizing, yellowing-resistant UV resin; 20-40 parts of UV-active monomer; 2-6 parts of photoinitiator.

[0118] It should be noted that the difference between UV odorless and yellowing-resistant solid color primer and UV odorless and yellowing-resistant white solid color primer lies in the color of the pigments.

[0119] Among them, the long-lasting yellowing-resistant multifunctional additive is rutile-type pigment-grade and micron-sized titanium dioxide, which has the functions of ultraviolet shielding, sun protection, and photo-oxidation and thermal stability, and can effectively achieve yellowing resistance. The particle size of titanium dioxide is 100~400nm.

[0120] The long-lasting, odor-free, and yellowing-resistant UV resin is an equal mixture of aliphatic non-aromatic polyurethane acrylate resin (Houding HD-200 is used in this application), silicone-modified or polyurethane-modified epoxy acrylate resin, and pure acrylic resin.

[0121] The UV-active monomer is a mixture of tetramethylpropylenediamine (TMPDA), tripropylene glycol diacrylate (TPGDA), and dipropylene glycol diacrylate (DPGDA) in equal proportions.

[0122] The photoinitiator has long-lasting resistance to yellowing and ultra-low odor, and is specifically a mixture of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, methyl benzoylformate and isopropylthioxanthrone in equal proportions.

[0123] Furthermore, in the long-lasting, odor-free, and yellowing-resistant UV resin, the preparation method of the organosilicon-modified epoxy acrylate resin is as follows: 10 parts of γ-methacryloxypropyltrimethoxysilane are added dropwise to 100 parts of epoxy acrylate resin heated at 80°C. After cooling to 50°C, 2 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 10 parts of isooctyl acrylate are added and stirred evenly.

[0124] By grafting γ-methacryloxypropyltrimethoxysilane onto epoxy acrylic resin, Si-O bonds are introduced into the molecular chain. The high-energy Si-O bonds can effectively resist the bombardment of ultraviolet light and reduce the breakage of the main chain. At the same time, γ-methacryloxypropyltrimethoxysilane forms a "silicon-oxygen protective layer" on the surface of the paint film, which effectively improves the ultraviolet absorption rate.

[0125] The preparation method of polyurethane modified epoxy acrylate resin in long-lasting, odor-free, and yellowing-resistant UV resin is as follows: 20 parts of hydroxyl-terminated polyurethane prepolymer and 0.2 parts of dibutyltin dilaurate are added to 100 parts of epoxy acrylate resin heated at 60℃. After reacting for 1.5 hours, 3 parts of 1-hydroxy-cyclohexyl-phenyl ketone and 10 parts of tripropylene glycol diacrylate are added and stirred until homogeneous.

[0126] By grafting hydroxyl-terminated polyurethane prepolymer with epoxy acrylate resin, urethane flexible segments are introduced into the epoxy backbone. The aliphatic structure of the polyurethane segments avoids the yellowing defect of aromatic isocyanates.

[0127] In some embodiments, in S202, the UV resin used in the UV-resistant, high-color-resistance yellow, magenta, cyan, and black solid color inks is an equal-proportion mixture of aliphatic non-aromatic polyurethane acrylate resin, modified epoxy acrylate resin, and pure acrylic resin (polyester acrylate resin and vinyl resin with poor yellowing resistance cannot be used); it should be noted that the modified epoxy acrylate resin used here is the modified epoxy acrylate resin in S103 and S104 above.

[0128] The preparation method for fatty acid-modified epoxy acrylic resin is as follows:

[0129] Mix 100 parts of bisphenol A epoxy resin with 0.1 parts of hydroquinone, melt at 90°C, add 30 parts of oleic acid (dropped over 1 hour) under stirring, heat to 110°C and react for 2 hours, cool to 80°C, add 25 parts of acrylic acid and 1 part of triethylamine, and react at 90°C for 3 hours to complete the preparation.

[0130] By esterifying oleic acid (containing an 18-carbon unsaturated long chain) with bisphenol A type epoxy resin, long-chain fatty acid groups are introduced into the epoxy backbone, breaking the rigid conjugated system of the benzene ring structure, improving the film elongation at break and reducing cracking caused by thermal cycling (-40~80℃). At the same time, the saturated carbon chain structure of fatty acids avoids the oxidation defects of benzene ring monomers, and combined with hydroquinone, the oxidation induction time of the coating film is extended.

[0131] The photoinitiator used above is a mixture of MBF (methyl benzoylformate), TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), and ITX (isopropylthioxanthone) in equal proportions. Other conventional photoinitiators and their mixtures, such as 1173, 184, 651, BP, etc., which have poor resistance to yellowing and odor neutralization, or have a strong odor, or poor resistance to yellowing, cannot be used.

[0132] The aforementioned long-lasting, yellowing-resistant, multifunctional additive possesses properties such as long-lasting yellowing resistance, UV shielding and absorption, sun protection, and photo-oxidative-thermal stability. Specifically, it is rutile-type ultrafine nano-titanium dioxide powder, a single crystal form produced by the vapor-phase method in nanocrystalline new materials, with a particle size of 10-100 nm. Utilizing the "angle-dependent color variation effect and light refraction effect" of rutile-type ultrafine nano-titanium dioxide powder from the vapor-phase method, the colors of the UV ink pattern image coating exhibit different visual effects when viewed from different angles, resulting in a lifelike and more dynamic and statically realistic visual effect, significantly improving the clarity and simulation of printed pattern images.

[0133] S203, UV-resistant, odor-neutralizing, yellowing-resistant, sand-finish primer, comprises the following components by weight:

[0134] 20-25 parts epoxy acrylate resin, 20-25 parts polyester acrylate resin, 10-15 parts polyurethane acrylate resin, 8-10 parts dipropylene glycol diacrylate, 12-15 parts tripropylene glycol diacrylate, 10-15 parts trimethylolpropane triacrylate, 2-3 parts 2-hydroxy-2-methyl-1-phenylpropanone, 2-3 parts 1-hydroxycyclohexylphenyl ketone, 2-3 parts 2,4,6-trimethylbenzoyl diphenoxyphosphide 5-10 parts lithopone, 5-10 parts talc, 5-10 parts transparent powder, 5-10 parts nano silica, 5-10 parts nano titanium dioxide, 5-10 parts zinc stearate, 0.01-1 part adhesion promoter, 0.01-1 part dispersant, 0.01-1 part wetting agent, 0.01-1 part defoamer, 0.01-1 part cosolvent, 0.01-1 part antisettling agent, and 2-5 parts rutile pigment-grade and micron-grade titanium dioxide.

[0135] In S203, the hardening primer comprises the following components by weight:

[0136] 10 parts epoxy acrylate resin, 30 parts polyurethane acrylate resin, 10 parts amino acrylate resin, 7 parts dipropylene glycol diacrylate, 8 parts tripropylene glycol diacrylate, 10 parts trimethylolpropane triacrylate, 5 parts 1,6-hexanediol diacrylate, 2 parts 2-hydroxy-2-methyl-1-phenylpropanone, 2 parts 1-hydroxycyclohexylphenyl ketone, 2 parts 2,4,6-trimethylbenzoyl diphenoxyphosphorus, 5 parts lithopone, 5 parts nano silica, 0.01 parts adhesion promoter, 0.01 parts dispersant, 0.01 parts wetting agent, 0.01 parts defoamer, 0.01 parts cosolvent, 0.01 parts anti-settling agent, 0.01 parts ultraviolet light absorber, and 3 parts rutile pigment-grade and micron-grade titanium dioxide.

[0137] S303 UV-Clean Odorless Anti-Yellowing Color-Correcting Clear Primer comprises the following components by weight:

[0138] 25 parts polyester acrylate resin, 15 parts polyurethane acrylate resin, 25 parts amino acrylate resin, 5 parts dipropylene glycol diacrylate, 10 parts tripropylene glycol diacrylate, 15 parts trimethylolpropane triacrylate, 3 parts 2-hydroxy-2-methyl-1-phenylpropanone, 3 parts 1-hydroxycyclohexylphenyl ketone, 3 parts 2,4,6-trimethylbenzoyl diphenoxyphosphine, 3 parts 2-isopropylthioxanthraquinone, 4- 3 parts ethyl dimethylformate, 10 parts lithopone, 10 parts talc, 10 parts nano silica, 10 parts nano titanium dioxide, 10 parts zinc stearate, 0.1 parts adhesion promoter, 0.1 parts dispersant, 0.1 parts wetting agent, 0.1 parts defoamer, 0.1 parts cosolvent, 0.1 parts anti-settling agent, 0.1 parts ultraviolet absorber, and 3 parts long-lasting anti-yellowing multifunctional additive (rutile pigment-grade and micron-sized titanium dioxide).

[0139] It should be noted that the adhesion promoter mentioned above is silane coupling agent KH-570, the dispersant is BYK-163, the wetting agent is BASF EFKA-3600, the cosolvent is propylene glycol methyl ether acetate (PMA), the anti-settling agent is fumed silica, and the ultraviolet light absorber is BASF Tinuvin 400.

[0140] In some embodiments, in S302, the UV-resistant, odor-neutralizing, yellowing-resistant, texture-enhancing clear topcoat includes the following materials:

[0141] 20-25 parts polyurethane acrylic resin, 25-40 parts epoxy acrylic resin, 30-40 parts functional active monomers (equal parts of DPGDA dipropylene glycol diacrylate, TPGDA tripropylene glycol acrylate, TMPTA trimethylolpropane acrylate, and HEMA hydroxyethyl methacrylate), 4-7 parts photoinitiator (equal parts of MBF, TPO, and ITX), 0.2-0.4 parts defoamer (defoaming polymer solution), and 0.4-0.6 parts leveling agent (polysiloxane-ether copolymer solution).

[0142] In some embodiments, S304, by weight parts, comprises:

[0143] 100 parts of a composition of waterborne acrylic modified polyurethane resin and waterborne polyurethane dispersion;

[0144] 5-15 parts of curing agent;

[0145] 10-20 parts diluent;

[0146] 0.2-2.0 parts of ultraviolet light absorber, anti-aging and antioxidant sunscreen additives;

[0147] VOCs purifying and deodorizing agent: 3.0~6.0 parts;

[0148] 1.0 to 3.0 parts of additives.

[0149] The curing agent is a combination of hydrophilic modified aliphatic polyisocyanate and hydrophilic modified alicyclic polyisocyanate;

[0150] The diluent is purified water;

[0151] The ultraviolet light absorber, anti-aging and antioxidant sunscreen additive is a composition of 2-hydroxy-4-methoxybenzophenone, 4-hydroxy-2,2,6,6-tetramethylpiperidine, hexyl diethylaminohydroxybenzoylbenzoate, ethylhexyl methoxycinnamate, rutile fumed nano titanium dioxide, and nano zinc dioxide.

[0152] The VOCs purifying and deodorizing agent is a composition of nano-silica, nano-photocatalyst, chitosan, and ethylene urea in equal proportions.

[0153] The preparation of hydrophilic modified aliphatic polyisocyanate includes the following steps: 30g of hexamethylene diisocyanate (HDI) is mixed with 65mL of acetone, and then a solution of dimethylolpropionic acid in acetone (mass-volume ratio of dimethylolpropionic acid to acetone is 1:2) is added dropwise at 50°C under a nitrogen atmosphere. After the addition is complete, the reaction is maintained at 50°C for 2h under stirring. After the reaction is completed, triethylamine is added under stirring until the pH reaches 7.5. After the product is cooled to room temperature, it is distilled under reduced pressure to obtain hydrophilic modified aliphatic polyisocyanate.

[0154] The preparation of hydrophilic modified alicyclic polyisocyanate includes the following steps: 40g of isophorone diisocyanate (IPDI) is mixed with 75mL of toluene, and then heated to 70℃ under a nitrogen atmosphere. A toluene solution of polyethylene glycol (polyethylene glycol to toluene mass-volume ratio of 2:3) is added dropwise. After the addition is complete, the reaction is maintained at 70℃ for 3h. After the product is cooled to room temperature, it is distilled under reduced pressure to obtain hydrophilic modified alicyclic polyisocyanate.

[0155] In some embodiments, the pretreatment solution in S301 and S302 is prepared by dissolving lithium stearate in ethanol, adding 50 nm of silver peroxide, and ultrasonically dispersing for 30 min to obtain the pretreatment solution. The concentration of lithium stearate is 0.2~0.4 wt%, and the concentration of silver peroxide is 0.1 wt%.

[0156] S301 and S302 share a common pretreatment solution, and the same pretreatment operation is repeated on the surfaces of the third intermediate coating and the first topcoat. The lithium stearate in the solution penetrates into the micropores of the first topcoat, improving the stress distribution during subsequent film pressing and roller coating, reducing the generation of cracks at the texture shaping area, and at the same time, the oxidation effect of silver peroxide eliminates uncured small molecule residues on the surfaces of the third intermediate coating and the first topcoat, avoiding pinhole defects in the subsequent topcoat.

[0157] In some embodiments, the preparation method of the surface modification liquid in S303 and S304 is as follows: on the basis of the pretreatment liquid, 1 wt% of modified aerogel is added to the pretreatment liquid, and then 0.3% of diphenyl phosphonate is added. After ultrasonic dispersion for 25 min, the surface modification liquid is obtained.

[0158] The modified aerogel was prepared by dissolving γ-aminopropyltriethoxysilane in anhydrous ethanol at a mass ratio of 1:20, adding aerogel and tannic acid at a mass ratio of 10:1, dispersing at 500 r / min for 5 min, stirring at 3000 r / min for 30 min, and then distilling under reduced pressure to obtain the modified aerogel. The mass ratio of aerogel to anhydrous ethanol was 1:10.

[0159] A surface-modified liquid was prepared based on the pretreatment liquid. The original lithium stearate in the pretreatment liquid was coated on the surface of the aerogel, which enhanced the compatibility with water-based paints (water-based UV odor-free and yellowing-resistant color-correcting clear primer and water-based odor-free and yellowing-resistant clear topcoat). While enhancing the adhesion, diphenyl phenylphosphonate and the residual silver peroxide formed a synergistic antioxidant system, which improved the yellowing resistance and color fastness.

[0160] The pretreatment liquid components in the surface modification liquid form hydrogen bonds with the water-based resin of the third surface coating, while the newly added aerogel can act as a "micro-container" to store VOCs purifiers, prolonging the odor-neutralizing effect. The aerogel in the modification liquid buffers the stress generated by moisture evaporation, further reducing the coating cracking rate. Example

[0161] Section S1: Primer composite coating, including the application of 4 primer coats; see Table 1 for details;

[0162] Section S2: Digital color composite coating, including coating of 3 intermediate coating layers; see Table 2 for details;

[0163] Section S3: Water-based paint topcoat modification composite coating, including the coating of 4 topcoat layers; see Table 3 for details.

[0164] In this embodiment, the parameters and process of the primer composite coating in section S1 are shown in Table 1.

[0165] Table 1

[0166] In this embodiment, the parameters and processes for digital color composite coating in section S2 are shown in Table 2.

[0167] Table 2

[0168] In this embodiment, the parameters and processes for water-based paint topcoat modification composite coating in section S3 are shown in Table 3.

[0169] Table 3

[0170] The components and formulations of the functional coatings used in the above-mentioned processes are as follows:

[0171] 1) UV Odorless, Yellowing-Resistant, High-Adhesion Clear Primer: 22 parts epoxy acrylate resin, 16 parts polyester acrylate resin, 12 parts amino acrylate resin, 8 parts dipropylene glycol diacrylate, 12 parts tripropylene glycol diacrylate, 12 parts trimethylolpropane triacrylate, 3 parts 2-hydroxy-2-methyl-1-phenylpropanone, 3 parts 1-hydroxycyclohexylphenyl ketone, 5 parts long-lasting yellowing-resistant multifunctional additive (rutile pigment-grade and micron-grade titanium dioxide), 5 parts nano-silica titanium dioxide, 0.1 parts silane coupling agent KH-570, 0.05 parts BYK-163, 0.05 parts EFKA-2722, 0.01 parts propylene glycol methyl ether acetate, and 0.05 parts fumed silica.

[0172] 2) UV Odorless Anti-Yellowing Adhesion Putty Primer: 25 parts epoxy acrylate resin, 25 parts amino acrylate resin, 8 parts dipropylene glycol diacrylate, 12 parts tripropylene glycol diacrylate, 12 parts trimethylolpropane triacrylate, 3 parts 2-hydroxy-2-methyl-1-phenylpropanone, 3 parts 1-hydroxycyclohexylphenyl ketone, 5 parts lithopone, 5 parts talc, 5 parts nano silica, 5 parts long-lasting anti-yellowing multifunctional additive (rutile pigment grade and micron-sized titanium dioxide), 0.1 parts silane coupling agent KH-570, 0.05 parts BYK-163, 0.01 parts BASF EFKA-3600, 0.05 parts defoamer Efka EFKA-2722, 0.01 parts propylene glycol methyl ether acetate, and 0.05 parts fumed silica.

[0173] 3) UV Odorless Anti-Yellowing White Solid Color Primer: 6 parts of long-lasting anti-yellowing multifunctional additive (rutile pigment-grade and micron-grade titanium dioxide), 60 parts of UV resin, 35 parts of UV active monomer (a mixture of tetramethylpropylenediamine, tripropylene glycol diacrylate and dipropylene glycol diacrylate in equal proportions), and 5 parts of photoinitiator (a mixture of MBF, TPO and ITX in equal proportions).

[0174] The long-lasting, odor-free, and yellowing-resistant UV resin is a mixture of equal proportions of Houding HD-200 polyurethane resin, silicone-modified epoxy acrylic resin, and pure acrylic resin.

[0175] 4) UV Odorless and Yellowing-Resistant Color Correcting Primer: 5 parts of long-lasting yellowing-resistant multifunctional additive (rutile pigment-grade and micron-grade titanium dioxide), 60 parts of long-lasting odorless and yellowing-resistant UV resin, 35 parts of UV active monomer (a mixture of tetramethylpropylenediamine, tripropylene glycol diacrylate and dipropylene glycol diacrylate in equal proportions), and 5 parts of photoinitiator (a mixture of MBF, TPO and ITX in equal proportions).

[0176] The long-lasting, odor-free, and yellowing-resistant UV resin is a mixture of equal proportions of Houding HD-200 polyurethane resin, polyurethane-modified epoxy acrylic resin, and pure acrylic resin.

[0177] 5) UV-resistant, low-odor, high-color-resistance yellow, magenta, cyan, and black solid color inks: 4 parts of long-lasting, low-odor, and high-color-resistance multifunctional additive (rutile pigment-grade and micron-grade titanium dioxide), 60 parts of long-lasting, low-odor, and high-color-resistance UV resin (a mixture of fatty acid-modified epoxy acrylate resin and pure acrylic resin in equal proportions), 35 parts of UV active monomer (a mixture of tripropylene glycol diacrylate and dipropylene glycol diacrylate in equal proportions), 5 parts of photoinitiator (a mixture of TPO, BMF, and ITX in equal proportions), 0.2 parts of defoamer (a defoaming polymer solution), 0.5 parts of leveling agent (a polysiloxane-ether copolymer solution), and 10 parts of pigment.

[0178] 6) Odorless, Anti-yellowing, Sandblasted Clear Primer: 20 parts epoxy acrylate resin, 205 parts polyester acrylate resin, 10 parts polyurethane acrylate resin, 8 parts dipropylene glycol diacrylate, 12 parts tripropylene glycol diacrylate, 10-15 parts trimethylolpropane triacrylate, 2 parts 2-hydroxy-2-methyl-1-phenylpropanone, 2 parts 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyl diphenoxyphosphorus, 5 parts lithopone, talc 5 parts powder, 5 parts transparent powder, 6 parts nano silica, 5 parts nano titanium dioxide, 5 parts zinc stearate, 0.01 parts silane coupling agent KH-570, 0.05 parts BYK-163, 0.1 parts BASF EFKA-3600, 0.01 parts defoamer Efka EFKA-2722, 0.02 parts propylene glycol methyl ether acetate, 0.05 parts fumed silica, and 2 parts rutile pigment-grade and micron-grade titanium dioxide.

[0179] 7) UV-Clean Odor-Free, Yellowing-Resistant, Synchronous Textured Clear Topcoat: 20 parts polyurethane acrylic resin, 25 parts epoxy acrylic resin, 30 parts functional active monomers (equal proportions of DPGDA dipropylene glycol diacrylate, TPGDA tripropylene glycol acrylate, TMPTA trimethylolpropane acrylate, and HEMA hydroxyethyl methacrylate), 4 parts photoinitiator (equal proportions of MBF, TPO, and ITX), 0.2 parts defoamer (defoaming polymer solution), and 0.5 parts leveling agent (polysiloxane-ether copolymer solution).

[0180] 8) Water-based UV Odorless Anti-yellowing Color Correcting Primer: The difference between it and UV Odorless Anti-yellowing Color Correcting Solid Color Primer is that it also includes 5 parts of fumed silica and 0.5 parts of wetting agent (BASF EFKA-3600).

[0181] 9) Water-based Odorless High-Yellowing Resistance Clear Topcoat: 100 parts of a composition of water-based acrylic modified polyurethane resin and water-based polyurethane dispersion (mixed in equal proportions), 10 parts of curing agent (a composition of hydrophilic modified aliphatic polyisocyanate and hydrophilic modified alicyclic polyisocyanate), 12 parts of diluent (purified water), 0.5 parts of UV absorber, anti-aging and antioxidant sunscreen additives (a composition of 2-hydroxy-4-methoxybenzophenone, 4-hydroxy-2,2,6,6-tetramethylpiperidine, hexyl diethylaminohydroxybenzoylbenzoate, ethylhexyl methoxycinnamate, and rutile fumed nano titanium dioxide and nano zinc dioxide), 5 parts of VOCs purifying and odor-neutralizing agent (a composition of nano silica, nano titanium dioxide, chitosan, and ethylene urea in equal proportions), and 1 part of additives (0.2 parts of defoamer, 0.5 parts of leveling agent, and 0.3 parts of anti-settling agent).

[0182] The defoamer is EFKA-2722, the leveling agent is BYK-333, and the anti-settling agent is fumed silica.

[0183] 10) Preparation method of pretreatment solution: After dissolving lithium stearate in anhydrous ethanol, add 50 nm silver peroxide and ultrasonically disperse for 30 min to obtain pretreatment solution. The concentration of lithium stearate in anhydrous ethanol is 0.4 wt% and the concentration of silver peroxide in anhydrous ethanol is 0.1 wt%.

[0184] 11) Preparation method of surface modification liquid: Based on the pretreatment liquid, add 1 wt% modified aerogel to the pretreatment liquid, then add 0.3% diphenyl phosphonate of the pretreatment liquid, and after ultrasonic dispersion for 25 min, the surface modification liquid is obtained.

[0185] The modified aerogel is prepared by dissolving γ-aminopropyltriethoxysilane in anhydrous ethanol at a mass ratio of 1:20, adding aerogel and tannic acid at a mass ratio of 10:1, dispersing at 500 r / min for 5 min, stirring at 3000 r / min for 30 min, and then distilling under reduced pressure to obtain the modified aerogel, wherein the mass ratio of aerogel to anhydrous ethanol is 1:10. Example

[0186] The difference between this embodiment and Embodiment 1 is that a hardening primer is used in S203.

[0187] The components and formulation of the hardening primer are as follows:

[0188] 10 parts epoxy acrylate resin, 30 parts polyurethane acrylate resin, 10 parts amino acrylate resin, 7 parts dipropylene glycol diacrylate, 8 parts tripropylene glycol diacrylate, 10 parts trimethylolpropane triacrylate, 5 parts 1,6-hexanediol diacrylate, 2 parts 2-hydroxy-2-methyl-1-phenylpropanone, 2 parts 1-hydroxycyclohexylphenyl ketone, 2 parts 2,4,6-trimethylbenzoyl diphenoxyphosphorus, 5 parts lithopone, 5 parts nano silica, 0.01 parts adhesion promoter, 0.01 parts dispersant, 0.01 parts wetting agent, 0.01 parts defoamer, 0.01 parts cosolvent, 0.01 parts anti-settling agent, 0.01 parts ultraviolet light absorber, and 3 parts rutile pigment-grade and micron-grade titanium dioxide.

[0189] Based on Example 1, a corresponding comparative example is given:

[0190] In the S1 section's primer coating, the dosage of the long-lasting anti-yellowing multifunctional additive in the first, second, third, and fourth primer coatings is adjusted, while the coating and curing processes remain unchanged. Specific dosage adjustments are shown in Table 4. Additionally, the spraying amounts of the pretreatment liquid and surface-modifying liquid in S301~S304 are adjusted (the spraying amount of the pretreatment liquid in S301 and S302 remains consistent, and the spraying amount of the surface-modifying liquid in S303 and S304 remains consistent). Specific spraying amounts are also shown in Table 4.

[0191] Table 4

[0192] The results are shown in Table 5.

[0193] Table 5

[0194] It can be seen that when the amount of long-lasting anti-yellowing multifunctional additive added to the primer in the first, second, third, and fourth primer coatings increased from 5 parts to 15 parts, the surface simulation degree showed a trend of first improving and then deteriorating, while other properties all showed a positive improvement. Meanwhile, Comparative Examples 1-2 and 1-3 increased the spraying amount of pretreatment liquid and surface modifying liquid in S301~S304, resulting in a significant improvement in yellowing resistance and a significant decrease in TVOC. Furthermore, excessive spraying amounts of pretreatment liquid and surface modifying liquid can negatively impact the surface simulation degree.

[0195] Based on Example 2, a corresponding comparative example is given:

[0196] In the topcoat of the water-based paint surface modification composite coating in section S3, the spraying amount of pretreatment liquid and surface modification liquid of S301~S304 is adjusted separately (the spraying amount of pretreatment liquid of S301 and S302 is always consistent, and the spraying amount of surface modification liquid of S303 and S304 is always consistent). For specific dosage adjustments, please refer to Table 6.

[0197] Table 6

[0198] The results are shown in Table 7.

[0199] Table 7

[0200] It can be seen that in the topcoat of the water-based paint modified composite coating in section S3, the amount of pretreatment liquid (S301~S304) and surface modification liquid sprayed will have a certain impact on the surface simulation. The presence of silver peroxide inhibits early oxidation, and diphenyl phenylphosphonate enhances long-term oxidation resistance. Therefore, the yellowing resistance of Comparative Example 2-2 remains at a good level, which is better than that of Comparative Example 2-1. In addition, the amount of pretreatment liquid and surface modification liquid sprayed also contributes significantly to its scratch resistance, effectively reducing peeling and extending service life.

[0201] Based on the comparative test results of the above embodiments and comparative examples, it can be concluded that:

[0202] (1) When the amount of long-lasting anti-yellowing multifunctional additive added to the primer of the base coating is preferably 10 to 15 parts, a better cost performance can be obtained;

[0203] (2) When the amount of pretreatment liquid and surface modification liquid sprayed in the topcoat is 5g / m 2 7g / m 2 When done in this way, a better cost-performance ratio can be obtained.

[0204] This application provides a three-stage modified coating process for odor-free, age-resistant, and crack-resistant solid wood water-based paint boards. The process involves setting a yellowing-resistant solid white primer and two yellowing-resistant color-correcting primers in the base coat. While obtaining a correctable standardized base color, the high yellowing resistance of the solid color-correcting primers covers and counteracts the cumulative weakening effect of the yellowing resistance of the underlying transparent primer coatings and substrate layers, thereby ensuring the high yellowing resistance of the overall coating.

[0205] In the digital color composite coating of the S2 section, digital color coatings are used to replace and surpass the decorative colors and textures on the surface of the master sample materials such as natural wood veneer and engineered wood veneer. While achieving the decorative effect of solid wood paint in an industrialized and standardized manner, it can also ensure that the overall coating has high aging resistance, oxidation resistance, and excellent performance in terms of high resistance to discoloration, yellowing, and cracking.

[0206] Water-based topcoats with thinner film thickness, fewer or no benzene rings and rigid carbon-carbon double bonds, and superior aging resistance can replace thicker UV topcoats with rigid benzene rings (aromatic rings) and poorer aging resistance. Furthermore, larger doses of UV absorbers, anti-photoaging and antioxidant additives can be added to the water-based topcoat. This improves the topcoat's resistance to photodiscoloration, oxidation discoloration, and yellowing without affecting its curing efficiency and odor-neutralizing effect, achieving a multi-functional effect that balances odor neutralization and aging resistance. Pretreatment in the topcoat... The coating consists of a liquid and a surface-modifying liquid. The long-chain structure of lithium stearate is embedded between the molecular chains of UV resin, which effectively reduces the brittleness of the coating. Combined with the stress dispersion of texture shaping during subsequent roller coating, it reduces the generation of microcracks and improves the unstable interlayer adhesion and delamination problem during texture shaping. The aerogel in the surface-modifying liquid has a porous structure, which buffers the stress of S304 two-stage drying. The silver peroxide and diphenyl phenylphosphonate in it work synergistically with the UV absorber in S304 topcoat to improve yellowing resistance and achieve synergistic regulation of crack resistance and yellowing resistance.

[0207] Through heat treatment in an infrared heating dehumidification tunnel and a heated convection dehumidification vertical baking oven with a longer duration (1.5~3h) and a higher temperature (40~60℃), the low molecular weight, low boiling point VOCs and odor substances in the coating are completely volatilized and released from the surface as moisture evaporates. This allows the VOCs and odor substances in the substrate layer to be better volatilized and released from the surface and sides of the board, thereby achieving a better odor removal and VOC purification effect.

[0208] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A three-stage modified coating process for odorless, weather-resistant, and crack-resistant wood paint panels, characterized in that, It includes the following steps: S1 Section: Primer Composite Coating: S101, First base coat coating: After sanding and dust removal of the substrate surface, apply UV odor-free, yellowing-resistant, high-adhesion clear primer and adhesive putty clear primer in sequence by roller coating. S102, Application of the second primer coating: Apply a UV-free, odor-free, yellowing-resistant, white solid-color primer by roller coating over the first primer coating; S103, Application of the third base coat: Apply a UV-free, odor-free, yellowing-resistant, color-correcting solid-color primer by roller coating over the second base coat. S104, the fourth base coat: apply a UV-free, odor-free, yellowing-resistant, color-correcting solid-color base coat by roller coating over the third base coat. S2 Section: Digitalized Color Composite Coating: S201, the first intermediate coating: a UV-resistant, odor-free, yellowing-resistant, high-adhesion clear primer is applied by roller over the fourth base coat of S104. S202, Coating of the second intermediate coating layer: UV-resistant, odor-free, high colorfastness yellow, magenta, cyan, and black solid color inks are sprayed onto the first intermediate coating layer respectively. S203, the application of the third intermediate coating: apply a UV-free, odor-free, yellowing-resistant, sand-finish primer or a hardened primer by roller coating over the second intermediate coating. S3 Section: Water-based paint topcoat modified composite coating: S301, Coating of the first topcoat layer: Spray a pretreatment liquid on the third intermediate coat layer, dry at 40~50℃ for 10~15 minutes, and then roll-coat a UV-clean, odor-free, yellowing-resistant, high-adhesion clear primer. S302, second topcoat coating: spray pretreatment liquid on top of the first topcoat, dry at 40~50℃ for 10~15min, then apply UV odor-free and yellowing-resistant synchronous textured clear topcoat with film roller. S303, the coating of the third topcoat: spray the surface modification liquid on the second topcoat, dry at 55~65℃ for 6~10 minutes, roll the water-based UV odor-free and yellowing-resistant color-correcting primer, and then heat and dehumidify and dry at 80~100℃ for 2 minutes. S304, fourth topcoat coating: Spray surface modifier on top of the third topcoat, dry at 55~65℃ for 6~10 minutes, then spray water-based odor-free and yellowing-resistant topcoat, first dry the surface layer in an infrared drying tunnel at 35~45℃ for 10 minutes, and then dry the inner layer in a heated and dehumidified vertical drying oven at 45~60℃ for 90~120 minutes. The spraying amount of the pretreatment liquid is 4-6 g / m 2 The preparation method is: dissolving lithium stearate in anhydrous ethanol, adding 50 nm silver peroxide, ultrasonic dispersion for 30 min to obtain a pretreatment liquid, the concentration of lithium stearate is 0.2-0.4 wt%, and the concentration of silver peroxide is 0.1 wt%. The spraying amount of the surface modification liquid is 6-8 g / m 2 The preparation method is as follows: on the basis of the pretreatment liquid, 1wt% modified aerogel is added into the pretreatment liquid, then 0.3% of the mass of the pretreatment liquid of diphenyl phenylphosphonate is added, and ultrasonic dispersion is performed for 25 min to obtain the surface modification liquid. The modified aerogel is prepared by dissolving γ-aminopropyltriethoxysilane in anhydrous ethanol at a mass ratio of 1:20, adding aerogel and tannic acid at a mass ratio of 10:1, dispersing at 500 r / min for 5 min, stirring at 3000 r / min for 30 min, and then distilling under reduced pressure to obtain the modified aerogel. The mass ratio of the aerogel to anhydrous ethanol is 1:

10.

2. The three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards as described in claim 1, characterized in that: In section S1, the coating speed for the primer composite coating is 16~18m / min; In section S2, the coating speed of digital color composite coating is 24~26m / min; In section S3, the coating speed for water-based paint topcoat modified composite coating is 5~6m / min.

3. The three-stage modified painting process of the tasteless, aging-resistant, and crack-resistant wood panel with water paint according to claim 1, characterized in that: The substrate is a hard, dense, crack-resistant, closed-type real wood veneer formaldehyde-free and odorless engineered wood board.

4. The three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards as described in claim 1, characterized in that: In section S1, the following are included: UV-resistant, odor-free, high-adhesion, non-yellowing, and non-adhesion clear primer; UV-resistant, odor-free, and non-yellowing, white solid-color primer; UV-resistant, odor-free, and non-yellowing, color-correcting solid-color primer; and UV-resistant, odor-free, and non-yellowing, color-correcting solid-color primer: The long-lasting anti-yellowing multifunctional additive used is rutile type pigment-grade and micron-sized ultrafine powder titanium dioxide in a single crystal form, with a particle size of 100~400nm. Calculated by mass, the amount of the long-lasting anti-yellowing multifunctional additive added accounts for 5~8% of the mass of each of the above primers. The UV resin used is an aliphatic non-aromatic polyurethane acrylate resin, silicone-modified or polyurethane-modified epoxy acrylate resin, pure acrylic resin, or a mixture thereof. The amount of UV resin added accounts for 46-65% of the mass of each of the above primers, calculated by mass. The UV-active monomers used are TMPTA trimethylolpropane acrylate, TPGDA tripropylene glycol acrylate, DPGDA dipropylene glycol diacrylate, or a mixture thereof. The amount of UV-active monomers added accounts for 25-45% of the mass of each of the above primers, calculated by weight. The photoinitiator used is TPO 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, BMF methyl benzoylformate, ITX isopropylthioxanthone, or a mixture thereof. The amount of photoinitiator added accounts for 2 to 6% of the mass of each of the above primers, calculated by mass.

5. The three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards as described in claim 1, characterized in that: UV-cured, odorless, and highly colorfast solid color inks in yellow, magenta, cyan, and black: The long-lasting, yellowing-resistant, multifunctional additive used is rutile-type ultrafine nano-titanium dioxide powder in a single crystal form, with a particle size of 10~100nm. Calculated by mass, the amount of the long-lasting, yellowing-resistant, multifunctional additive added accounts for 0.5~5% of the mass of the aforementioned UV-resistant, odor-free, high-color-resistance yellow, magenta, cyan, and black solid color inks. The UV resin used is an aliphatic non-aromatic polyurethane acrylate resin, fatty acid modified or polyurethane modified or silicone modified epoxy acrylate resin, pure acrylic resin, or a mixture thereof. Calculated by mass, the amount of UV resin added accounts for 30-60% of the mass of UV odorless high colorfastness yellow, magenta, cyan, and black solid color inks. The photoinitiator used is TPO 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, BMF methyl benzoylformate, ITX isopropylthioxanthone, or a mixture thereof. The amount of photoinitiator added accounts for 2 to 5% of the mass of each of the above primers, calculated by mass.

6. The three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards as described in claim 5, characterized in that: In fatty acid-modified, polyurethane-modified, or silicone-modified epoxy acrylic resins: The preparation method of fatty acid modified epoxy acrylic resin includes the following steps: 100 parts of bisphenol A epoxy resin were mixed with 0.1 parts of hydroquinone and melted at 90°C. Then, 30 parts of oleic acid were added under stirring. The mixture was heated to 110°C and reacted for 2 hours. The mixture was then cooled to 80°C and 25 parts of acrylic acid and 1 part of triethylamine were added dropwise. The mixture was then reacted at 90°C for 3 hours to complete the preparation. The preparation method of polyurethane-modified epoxy acrylic resin includes the following steps: Add 20 parts of hydroxyl-terminated polyurethane prepolymer and 0.2 parts of dibutyltin dilaurate to 100 parts of epoxy acrylate resin heated at 60°C. After reacting for 1.5 hours, add 3 parts of 1-hydroxy-cyclohexyl-phenyl ketone and 10 parts of tripropylene glycol diacrylate, and stir until homogeneous. The preparation method of silicone-modified epoxy acrylate resin includes the following steps: Add 10 parts of γ-methacryloxypropyltrimethoxysilane to 100 parts of epoxy acrylate resin heated at 80°C, cool to 50°C, then add 2 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 10 parts of isooctyl acrylate, and stir until homogeneous.

7. The three-stage modified coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards as described in claim 1, characterized in that: In S302, the UV-resistant, odor-free, yellowing-resistant, texture-enhancing clear topcoat, by weight, comprises: 20-25 parts polyurethane acrylic resin; 25-40 parts epoxy acrylic resin; 30-40 parts of an equal-proportion mixture of DPGDA dipropylene glycol diacrylate, TPGDA tripropylene glycol acrylate, TMPTA trimethylolpropane acrylate, and HEMA hydroxyethyl methacrylate; 4-7 parts of an equal-proportion mixture of MBF, TPO, and ITX; 0.2-0.4 parts of a defoaming polymer solution; and 0.4-0.6 parts of a polysiloxane-ether copolymer solution.

8. The three-stage modified painting process of the tasteless, aging-resistant, and crack-resistant wood panel with water paint according to claim 1, characterized in that, In S304, water-based, odorless, and yellowing-resistant clear topcoat, by weight, includes: 100 parts of a composition of waterborne acrylic modified polyurethane resin and waterborne polyurethane dispersion; 5-15 parts of curing agent; 10-20 parts diluent; 0.2-2.0 parts of ultraviolet light absorber, anti-aging and antioxidant sunscreen additives; VOCs purifying and deodorizing agent: 3.0~6.0 parts; Additives: 1.0~3.0 parts; The curing agent is a combination of hydrophilic modified aliphatic polyisocyanate and hydrophilic modified alicyclic polyisocyanate; The diluent is purified water; The ultraviolet light absorber, anti-aging and antioxidant sunscreen additive is a composition of 2-hydroxy-4-methoxybenzophenone, 4-hydroxy-2,2,6,6-tetramethylpiperidine, hexyl diethylaminohydroxybenzoylbenzoate, ethylhexyl methoxycinnamate, rutile fumed nano titanium dioxide, and nano zinc dioxide. The VOCs purifying and deodorizing agent is a composition of nano-silica, nano-photocatalyst, chitosan, and ethylene urea in equal proportions.

9. The three-stage digital coating process for odor-free, aging-resistant, and crack-resistant solid wood water-based paint boards as described in claim 1, characterized in that: The coating amount of the UV tasteless and yellowing-resistant high-adhesion base paint in S101 is 15-25 g / m 2 The coating amount of the adhesion putty base paint is 25-35 g / m 2 The UVA energy value of the UV light radiation is 200-400 mJ / cm 2 The UVV energy value is 300-600 mJ / cm 2 ; The coating amount of the primer in S102 and S103 is 20-30 g / m 2 The UVA energy value of the UV light radiation is 150-350 mJ / cm 2 The UVV energy value is 400-600 mJ / cm 2 ; The S104, the primer coating amount is 20~30g / m 2 , the UVA energy value of UV light radiation is 250~400mJ / cm 2 , the UVV energy value is 400~600mJ / cm 2 ; The S201, primer coating amount 10~20g / m 2 , UV light radiation UVA energy value is 150~300mJ / cm 2 , UVV energy value is 200~400mJ / cm 2 ; The ink coating amount in S202 is 1-10 g / m 2 The UVA energy value of UV light radiation is 200-400 mJ / cm 2 The UVV energy value is 300-600 mJ / cm 2 ; The S203, the primer coating amount is 15~25g / m 2 , the UVA energy value in the UV light radiation is 300~500 mJ / cm 2 , the UVV energy value is 400~800 mJ / cm 2 ; The primer coating amount in S301 is 15-25 g / m 2 The UVA energy value of UV light radiation is 150-300 mJ / cm 2 The UVV energy value is 200-400 mJ / cm 2 ; The coating amount of the topcoat in S302 is 150-250 g / m 2 The UVA energy value of the UV light radiation is 300-400 mJ / cm 2 The UVV energy value is 400-600 mJ / cm 2 ; The S303, the primer coating amount is 30~45g / m 2 , the UVA energy value of UV light radiation is 300~400mJ / cm 2 , the UVV energy value is 400~600mJ / cm 2 .

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