High-strength stain-resistant melamine-faced panel and method of making same

Abstract

The application discloses a high-strength and stain-resistant melamine veneer and a preparation method thereof, and belongs to the technical field of veneer preparation. The preparation method of the high-strength and stain-resistant melamine veneer comprises the following steps: step one, melamine and a nano reinforcing agent are added to distilled water, stirred and uniformly mixed to obtain a mixed emulsion, impregnated paper is placed into the mixed emulsion, soaked, taken out, and a composite impregnated paper is obtained; step two, a hard fiber board is selected as a base material, the composite impregnated paper is placed on the surface of the base material, and then placed on a press, hot-pressed, and cooled to obtain a melamine veneer containing melamine; and step three, stain-resistant paint is sprayed on the surface of the melamine veneer, and dried to obtain the high-strength and stain-resistant melamine veneer. The veneer prepared by the method has excellent strength and stain resistance.

Description

Technical Field

[0001] This invention belongs to the field of decorative panel preparation technology, specifically relating to high-strength, stain-resistant melamine decorative panels and their preparation methods. Background Technology

[0002] Melamine decorative panels, as an important decorative material in modern home manufacturing and interior decoration, have always had their research and optimization focused on solving the core problems of insufficient strength and poor stain resistance that are common in traditional boards. Although traditional melamine decorative panels occupy an important position in the market due to their rich pattern selection, good processing performance, and relatively low cost, their insufficient strength and poor stain resistance, which have been exposed during long-term use, have become bottlenecks restricting their further development.

[0003] Patent CN103526895A discloses a method for manufacturing high-strength, scratch-resistant, and fire-resistant decorative panels. Addressing the problems of cracking, curling, and scratch susceptibility in decorative panels widely used in existing building materials, this method provides a solution: using premium fire-resistant solid wood veneer or E1-grade fire-resistant high-density fiberboard as the base layer, melamine-impregnated paper as the middle layer, and aluminum oxide as the surface layer, the panels are hot-pressed using a cold-hot-cold hot-pressing process. This achieves anti-cracking, anti-curling, anti-deformation, scratch-resistant, and fire-resistant properties. However, there is still room for improvement in the strength and stain resistance of the decorative panels prepared by this method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength, stain-resistant melamine decorative panel and its preparation method, in order to solve the technical problems of poor mechanical properties and stain resistance of decorative panels in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for preparing a high-strength, stain-resistant melamine decorative panel, comprising the following steps:

[0007] Step 1: Add melamine and nano-reinforcing agent to distilled water, stir and mix evenly to obtain a mixed emulsion, immerse the impregnated paper in the mixed emulsion, remove it, and obtain composite impregnated paper;

[0008] Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, then place it on a press, hot press, and cool to obtain a melamine-containing decorative panel;

[0009] Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and let it dry to obtain a high-strength, stain-resistant melamine decorative panel.

[0010] Preferably, in step one, the ratio of melamine, nano-reinforcing agent, and distilled water is (4-6)g:(1-3)g:(250-280)mL, the mixing time is 2-3h, and the soaking time is 8-12h; in step two, a hot-pressing method with high temperature and short cycle and low temperature and long cycle is adopted, with a pressure of 2-3MPa, a temperature of 160-200℃, and a hot-pressing time of 30-60s per sheet; in step three, the drying temperature is 45-55℃, and the time is 18-24h.

[0011] Preferably, the preparation method of the nano-reinforcing agent includes the following steps:

[0012] Q1: Cellulose nanocrystals were added to a container containing dimethyl sulfoxide, then L-lactide was added, and the mixture was heated under a nitrogen atmosphere. Stannous octoate was then added, and the reaction was carried out. After the reaction was completed, the precipitate was collected, centrifuged, washed, and vacuum dried to obtain the complex.

[0013] Q2: Calcium chloride and ammonia water are mixed and stirred, then distilled water is added to obtain a mixed solution. Subsequently, the mixed solution, hexadecyltrimethylammonium bromide, n-butanol and cyclohexane are mixed and stirred. Sucrose is added during the mixing and stirring process to obtain a mixed emulsion. Carbon dioxide is bubbled into the mixed emulsion and the reaction is stirred continuously until no more precipitate is formed. The carbon dioxide bubbling is stopped, and the mixture is allowed to stand for aging, washed, centrifuged and dried to obtain nanoparticles. The complex and nanoparticles are added to a container containing a mixed solution of chloroform and petroleum ether, stirred and mixed, allowed to stand, dried and ball-milled to obtain a nano-reinforcing agent.

[0014] In the above process, cellulose nanocrystals and L-lactide undergo a polymerization reaction in dimethyl sulfoxide. Subsequently, stannous octoate is used as a catalyst to catalyze the ring-opening polymerization reaction of L-lactide, which increases the molecular chain of L-lactide to obtain a complex. Then, using calcium chloride, ammonia and sucrose as raw materials, nanoparticles are prepared under the action of carbon dioxide. Finally, the complex and nanoparticles are mixed to prepare a nano-reinforcing agent.

[0015] Preferably, in Q1, the ratio of cellulose nanocrystals, dimethyl sulfoxide, L-lactide, and stannous octoate is (0.3-0.5)g:(8-12)mL:(9-15)g:(0.09-0.15)g. When the system temperature is 128-135℃, stannous octoate is added, the reaction time is 18-24h, methanol is added for precipitation, the centrifugation speed is 8000-12000rpm, the time is 8-12min, the system is washed with methanol and chloroform, and vacuum drying is performed at 40-50℃ for 24-36h.

[0016] Preferably, in Q2, the ratio of calcium chloride, ammonia, and distilled water is (1.23-1.62)g:(0.9-1.2)g:(10-12)mL; the volume ratio of the mixed solution, hexadecyltrimethylammonium bromide, n-butanol, and cyclohexane is (2-4):(50-75):(8-14):(15-25); the flow rate of carbon dioxide is 300mL / min; the aging time is 12-15h; the product is washed with ethanol; and the drying temperature is 70-80℃ for 24-32h. The ratio of the composite, nanoparticles, chloroform, and petroleum ether is (3-5)g:(1-1.2)g:(6-8)mL:(4-6)mL; the mixing and stirring time is 20-24h; and the drying temperature is 35-38℃ for 32-36h.

[0017] Preferably, the method for preparing the stain-resistant coating includes the following steps:

[0018] S1: Perfluoropolyether carboxylic acid and fluorocarbon solvent were added to a container, followed by the addition of pyridine. After heating and stirring, thionyl chloride was added dropwise and stirring was continued. After stirring was completed, the mixture was distilled under reduced pressure, and pentaerythritol triacrylate was added. The mixture was then heated to react and give compound 1.

[0019] S2: Magnesium powder, methyltriethoxysilane, iodine powder and tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated. Then 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred, cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2.

[0020] S3: Add compound 1 and fluorocarbon solvent to a container, then add compound 2, stir the reaction, continue to heat the reaction, then cool to room temperature, wash, dissolve, separate the liquids to obtain a stain-resistant coating.

[0021] In the above process, perfluoropolyether carboxylic acid is used as a raw material and undergoes a substitution reaction with thionyl chloride, followed by a substitution reaction with pentaerythritol triacrylate to prepare compound 1. Then, methyltriethoxysilane and 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene are used as raw materials to undergo an addition reaction to prepare compound 2. Subsequently, compound 1 and compound 2 react to prepare a stain-resistant coating. The synthetic reaction formula of the stain-resistant coating is as follows:

[0022]

[0023] Preferably, in S1, the ratio of perfluoropolyether carboxylic acid, fluorocarbon solvent, pyridine, thionyl chloride and pentaerythritol triacrylate is (3-5) g: (3-5) mL: (0.19-0.21) mL: (2-3) mL: (0.2-0.3) g, the heating and stirring temperature is 70-74℃, the stirring time is 10-14 min, the stirring time is continued for 6-10 h, the heating reaction temperature is 45-55℃, and the time is 24-28 h.

[0024] Preferably, in step S2, the ratio of magnesium powder, methyltriethoxysilane, iodine powder, tetrahydrofuran, and 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene is (4.2-4.6)g:(37.11-37.45)g:(0.1-0.12)g:(200-250)mL:(38-45)g, the oil bath temperature is 60-70℃, and the stirring time is 20-24h.

[0025] Preferably, in step S3, the ratio of compound 1, fluorocarbon solvent and compound 2 is (2-4)g:(2-5)mL:(0.4-0.6)g, the stirring reaction time is 30-45min, the heating reaction temperature is 50-60℃, and the reaction time is 10-12h.

[0026] Preferably, the high-strength, stain-resistant melamine decorative panel is prepared by the method described in any one of claims 1-9.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] 1. This invention first prepares a nano-reinforcing agent using cellulose nanocrystals, L-lactide, calcium chloride, ammonia, and sucrose as raw materials. Then, a stain-resistant coating is prepared using perfluoropolyether carboxylic acid, thionyl chloride, methyltriethoxysilane, and 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene as raw materials. Adding the nano-reinforcing agent and the stain-resistant coating to melamine decorative panels can effectively improve the strength and stain resistance of the panels.

[0029] 2. This invention adds the prepared nano-reinforcing agent to melamine decorative panels, which can effectively improve the strength of the panels. The cellulose nanocrystals added during the preparation of the nano-reinforcing agent have high strength and high modulus, providing an excellent mechanical basis for the nano-reinforcing agent. The nanoscale size of the reinforcing agent brings a high specific surface area, which allows the cellulose nanocrystals to form good dispersion and interfacial bonding in the matrix, which helps to improve the overall performance of the composite material. Moreover, the hydroxyl groups contained on its surface can be chemically modified to achieve diversified reinforcing functions, thereby enhancing the compatibility and bonding of the material. The prepared nanoparticles, as inorganic fillers, can fill the tiny pores in the melamine decorative panels, improving the density and overall strength of the panels. The whisker morphology of the nanoparticles helps to form a three-dimensional network structure in the decorative panels, enhancing their mechanical properties and impact resistance, thereby giving the melamine decorative panels high strength.

[0030] 3. This invention uniformly coats the prepared stain-resistant coating onto the surface of a melamine decorative panel, effectively improving its stain resistance. The main chain of the stain-resistant coating contains alternating carbon-oxygen bond units, giving it flexible rotational properties and low surface energy. This low surface energy makes the coating surface difficult to wet with water and other polar contaminants, effectively preventing contaminant adhesion. Furthermore, the presence of fluoride ions gives the stain-resistant coating excellent chemical resistance, resisting the erosion of various chemicals, allowing the panel to maintain its performance even in harsh environments. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: This example discloses a method for preparing a nano-reinforcing agent, including the following steps:

[0033] Q1: 0.4 g of cellulose nanocrystals were added to a container containing 10 mL of dimethyl sulfoxide, then 12 g of L-lactide was added. The mixture was heated to 128 °C under a nitrogen atmosphere, and 0.12 g of stannous octoate was added. The mixture was reacted for 24 h. After the reaction was completed, methanol was added to precipitate the mixture. The mixture was centrifuged at 12000 rpm for 12 min, washed with methanol and chloroform, and dried under vacuum at 50 °C for 36 h to obtain the complex.

[0034] Q2: Mix 1.42g of calcium chloride and 1.05g of ammonia water, then add 11mL of distilled water to obtain a mixed solution. Subsequently, mix 3mL of the mixed solution, 62.5mL of cetyltrimethylammonium bromide, 11mL of n-butanol, and 20mL of cyclohexane. During the mixing process, add 0.0142g of sucrose to obtain a mixed emulsion. Pass carbon dioxide into the mixed emulsion at a flow rate of 300mL / min and stir continuously until no more precipitate is formed. Stop passing carbon dioxide and let it stand for 12h. Wash with ethanol, centrifuge, and dry at 75℃ for 32h to obtain nanoparticles. Add 4g of the complex and 1.1g of nanoparticles to a container containing 7mL of chloroform and 5mL of petroleum ether mixed solution. Stir and mix for 24h, let stand, dry at 38℃ for 36h, and ball mill to obtain the nano-reinforcing agent.

[0035] This embodiment discloses a method for preparing a stain-resistant coating, including the following steps:

[0036] S1: Add 4g of perfluoropolyether carboxylic acid and 4mL of fluorocarbon solvent to a container, then add 0.2mL of pyridine dropwise. After heating to 74℃ and stirring for 14min, add 2.5mL of thionyl chloride dropwise and continue stirring for 10h. After stirring, distill under reduced pressure, add 0.25g of pentaerythritol triacrylate, and heat at 55℃ for 24h to obtain compound 1.

[0037] S2: 4.4 g magnesium powder, 37.28 g methyltriethoxysilane, 0.11 g iodine powder and 225 mL tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated to 70 °C. Then 42 g 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred for 24 h, then cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2.

[0038] S3: Add 3g of compound 1 and 3.5mL of fluorocarbon solvent to a container, then add 0.5g of compound 2, stir and react for 45min, then continue to heat at 55℃ for 12h, then cool to room temperature, wash, dissolve, separate the liquids to obtain the stain-resistant coating.

[0039] This example discloses a method for preparing a high-strength, stain-resistant melamine decorative panel, including the following steps:

[0040] Step 1: Add 5g of melamine and 2g of nano-reinforcing agent to 265mL of distilled water and stir for 3 hours to obtain a mixed emulsion. Place the impregnated paper into the mixed emulsion and soak for 12 hours. Remove the paper to obtain the composite impregnated paper.

[0041] Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, and then place it on the press. Use a hot pressing method with high temperature and short cycle and low temperature and long cycle. Set the pressure to 2MPa, the temperature to 180℃, and the hot pressing time to 45s per sheet. Cool to obtain melamine-containing decorative panel.

[0042] Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and dry it at 55℃ for 24 hours to obtain a high-strength stain-resistant melamine decorative panel.

[0043] Example 2: This example discloses a method for preparing a nano-reinforcing agent, including the following steps:

[0044] Q1: 0.3 g of cellulose nanocrystals were added to a container containing 8 mL of dimethyl sulfoxide, then 9 g of L-lactide was added. The mixture was heated to 128 °C under a nitrogen atmosphere, and 0.09 g of stannous octoate was added. The mixture was reacted for 24 h. After the reaction was completed, methanol was added to precipitate the mixture. The mixture was centrifuged at 12000 rpm for 12 min, washed with methanol and chloroform, and dried under vacuum at 50 °C for 36 h to obtain the complex.

[0045] Q2: Mix 1.23g of calcium chloride and 0.9g of ammonia water, then add 10mL of distilled water to obtain a mixed solution. Subsequently, mix 2mL of the mixed solution, 50mL of cetyltrimethylammonium bromide, 8mL of n-butanol, and 15mL of cyclohexane. During the mixing process, add 0.0123g of sucrose to obtain a mixed emulsion. Pass carbon dioxide into the mixed emulsion at a flow rate of 300mL / min and stir continuously until no more precipitate is formed. Stop passing carbon dioxide and let it stand for 12h. Wash with ethanol, centrifuge, and dry at 75℃ for 32h to obtain nanoparticles. Add 3g of the complex and 1g of nanoparticles to a container containing a mixed solution of 6mL of chloroform and 4mL of petroleum ether. Stir and mix for 24h, then let stand and dry at 38℃ for 36h. Ball mill to obtain the nano-reinforcing agent.

[0046] This embodiment discloses a method for preparing a stain-resistant coating, including the following steps:

[0047] S1: 3g of perfluoropolyether carboxylic acid and 3mL of fluorocarbon solvent were added to a container, followed by 0.19mL of pyridine. The mixture was heated to 74℃ and stirred for 14min. Then, 2mL of thionyl chloride was added and the mixture was stirred for 10h. After stirring, the mixture was distilled under reduced pressure and 0.2g of pentaerythritol triacrylate was added. The mixture was heated to 55℃ and reacted for 24h to obtain compound 1.

[0048] S2: 4.2g magnesium powder, 37.11g methyltriethoxysilane, 0.1g iodine powder and 200mL tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated to 70℃. Then 38g 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred for 24h, then cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2.

[0049] S3: Add 2g of compound 1 and 3mL of fluorocarbon solvent to a container, then add 0.4g of compound 2, stir and react for 45min, then continue to heat at 55℃ for 12h, then cool to room temperature, wash, dissolve, separate the liquids to obtain the stain-resistant coating.

[0050] This example discloses a method for preparing a high-strength, stain-resistant melamine decorative panel, including the following steps:

[0051] Step 1: Add 4g of melamine and 1g of nano-reinforcing agent to 250mL of distilled water and stir for 3 hours to obtain a mixed emulsion. Place the impregnated paper into the mixed emulsion and soak for 12 hours. Remove the paper to obtain the composite impregnated paper.

[0052] Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, and then place it on the press. Use a hot pressing method with high temperature and short cycle and low temperature and long cycle. Set the pressure to 2MPa, the temperature to 180℃, and the hot pressing time to 45s per sheet. Cool to obtain melamine-containing decorative panel.

[0053] Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and dry it at 55℃ for 24 hours to obtain a high-strength stain-resistant melamine decorative panel.

[0054] Example 3: This example discloses a method for preparing a nano-reinforcing agent, including the following steps:

[0055] Q1: 0.5g of cellulose nanocrystals were added to a container containing 12mL of dimethyl sulfoxide, followed by 15g of L-lactide. The mixture was heated to 128℃ under a nitrogen atmosphere, and then 0.15g of stannous octoate was added. The mixture was reacted for 24h. After the reaction was completed, methanol was added to precipitate the mixture. The mixture was centrifuged at 12000rpm for 12min, washed with methanol and chloroform, and dried under vacuum at 50℃ for 36h to obtain the complex.

[0056] Q2: Mix 1.62g of calcium chloride and 1.2g of ammonia water, then add 12mL of distilled water to obtain a mixed solution. Subsequently, mix 4mL of the mixed solution, 75mL of cetyltrimethylammonium bromide, 14mL of n-butanol, and 25mL of cyclohexane. During the mixing process, add 0.0162g of sucrose to obtain a mixed emulsion. Pass carbon dioxide into the mixed emulsion at a flow rate of 300mL / min and stir continuously until no more precipitate is formed. Stop passing carbon dioxide and let it stand for 12h. Wash with ethanol, centrifuge, and dry at 75℃ for 32h to obtain nanoparticles. Add 5g of the complex and 1.2g of nanoparticles to a container containing 8mL of chloroform and 6mL of petroleum ether mixed solution. Stir and mix for 24h, then let stand, dry at 38℃ for 36h, and ball mill to obtain the nano-reinforcing agent.

[0057] This embodiment discloses a method for preparing a stain-resistant coating, including the following steps:

[0058] S1: Add 5g of perfluoropolyether carboxylic acid and 5mL of fluorocarbon solvent to a container, then add 0.21mL of pyridine dropwise. After heating to 74℃ and stirring for 14min, add 3mL of thionyl chloride dropwise and continue stirring for 10h. After stirring, distill under reduced pressure, add 0.3g of pentaerythritol triacrylate, and heat at 55℃ for 24h to obtain compound 1.

[0059] S2: 4.6 g magnesium powder, 37.45 g methyltriethoxysilane, 0.12 g iodine powder and 250 mL tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated to 70 °C. Then 45 g 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred for 24 h, then cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2.

[0060] S3: Add 4g of compound 1 and 5mL of fluorocarbon solvent to a container, then add 0.6g of compound 2, stir and react for 45min, then continue to heat at 55℃ for 12h, then cool to room temperature, wash, dissolve, separate the liquids to obtain the stain-resistant coating.

[0061] This example discloses a method for preparing a high-strength, stain-resistant melamine decorative panel, including the following steps:

[0062] Step 1: Add 6g of melamine and 3g of nano-reinforcing agent to 280mL of distilled water and stir for 3 hours to obtain a mixed emulsion. Place the impregnated paper into the mixed emulsion and soak for 12 hours. Remove the paper to obtain the composite impregnated paper.

[0063] Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, and then place it on the press. Use a hot pressing method with high temperature and short cycle and low temperature and long cycle. Set the pressure to 2MPa, the temperature to 180℃, and the hot pressing time to 45s per sheet. Cool to obtain melamine-containing decorative panel.

[0064] Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and dry it at 55℃ for 24 hours to obtain a high-strength stain-resistant melamine decorative panel.

[0065] Example 4: This example discloses a method for preparing a nano-reinforcing agent, including the following steps:

[0066] Q1: 0.35 g of cellulose nanocrystals were added to a container containing 9 mL of dimethyl sulfoxide, then 11 g of L-lactide was added. The mixture was heated to 128 °C under a nitrogen atmosphere, and 0.11 g of stannous octoate was added. The mixture was reacted for 24 h. After the reaction was completed, methanol was added to precipitate the mixture. The mixture was centrifuged at 12000 rpm for 12 min, washed with methanol and chloroform, and dried under vacuum at 50 °C for 36 h to obtain the complex.

[0067] Q2: Mix 1.31g of calcium chloride and 1.1g of ammonia water, then add 10.5mL of distilled water to obtain a mixed solution. Subsequently, mix 2.5mL of the mixed solution, 55mL of cetyltrimethylammonium bromide, 9mL of n-butanol, and 18mL of cyclohexane. During the mixing process, add 0.0131g of sucrose to obtain a mixed emulsion. Pass carbon dioxide into the mixed emulsion at a flow rate of 300mL / min and stir continuously until no more precipitate is formed. Stop passing carbon dioxide and let it stand for 12h. Wash with ethanol, centrifuge, and dry at 75℃ for 32h to obtain nanoparticles. Add 3.5g of the composite and 1.05g of nanoparticles to a container containing a mixed solution of 6.5mL of chloroform and 4.5mL of petroleum ether. Stir and mix for 24h, then let stand and dry at 38℃ for 36h. Ball mill to obtain the nano-reinforcing agent.

[0068] This embodiment discloses a method for preparing a stain-resistant coating, including the following steps:

[0069] S1: 3.5 g of perfluoropolyether carboxylic acid and 4.5 mL of fluorocarbon solvent were added to a container, followed by 0.195 mL of pyridine. The mixture was heated to 74 °C and stirred for 14 min. Then, 2.4 mL of thionyl chloride was added and the mixture was stirred for another 10 h. After stirring, the mixture was distilled under reduced pressure, and 0.22 g of pentaerythritol triacrylate was added. The mixture was heated to 55 °C and reacted for 24 h to obtain compound 1.

[0070] S2: 4.3g magnesium powder, 37.23g methyltriethoxysilane, 0.115g iodine powder and 210mL tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated to 70℃. Then 39g 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred for 24h, then cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2.

[0071] S3: Add 2.5g of compound 1 and 4mL of fluorocarbon solvent to a container, then add 0.45g of compound 2, stir and react for 45min, then continue to heat at 55℃ for 12h, then cool to room temperature, wash, dissolve, separate the liquids to obtain the stain-resistant coating.

[0072] This example discloses a method for preparing a high-strength, stain-resistant melamine decorative panel, including the following steps:

[0073] Step 1: Add 4.5g of melamine and 1.5g of nano-reinforcing agent to 260mL of distilled water and stir for 3 hours to obtain a mixed emulsion. Place the impregnated paper into the mixed emulsion and soak for 12 hours. Remove the paper to obtain the composite impregnated paper.

[0074] Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, and then place it on the press. Use a hot pressing method with high temperature and short cycle and low temperature and long cycle. Set the pressure to 2MPa, the temperature to 180℃, and the hot pressing time to 45s per sheet. Cool to obtain melamine-containing decorative panel.

[0075] Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and dry it at 55℃ for 24 hours to obtain a high-strength stain-resistant melamine decorative panel.

[0076] Example 5: This example discloses a method for preparing a nano-reinforcing agent, including the following steps:

[0077] Q1: 0.45 g of cellulose nanocrystals were added to a container containing 11 mL of dimethyl sulfoxide, then 14 g of L-lactide was added. The mixture was heated to 128 °C under a nitrogen atmosphere, and 0.14 g of stannous octoate was added. The mixture was reacted for 24 h. After the reaction was completed, methanol was added to precipitate the mixture. The mixture was centrifuged at 12000 rpm for 12 min, washed with methanol and chloroform, and dried under vacuum at 50 °C for 36 h to obtain the complex.

[0078] Q2: Mix 1.58g calcium chloride and 0.98g ammonia water, then add 11.5mL distilled water to obtain a mixed solution. Subsequently, mix 3.5mL of the mixed solution, 70mL of cetyltrimethylammonium bromide, 12mL of n-butanol, and 23mL of cyclohexane. During the mixing process, add 0.0158g of sucrose to obtain a mixed emulsion. Pass carbon dioxide into the mixed emulsion at a flow rate of 300mL / min and stir continuously until no more precipitate is formed. Stop passing carbon dioxide and let it stand for 12h. Wash with ethanol, centrifuge, and dry at 75℃ for 32h to obtain nanoparticles. Add 4.5g of the complex and 1.15g of nanoparticles to a container containing a mixed solution of 7.5mL chloroform and 5.5mL petroleum ether. Stir and mix for 24h, then let stand and dry at 38℃ for 36h. Ball mill to obtain the nano-reinforcing agent.

[0079] This embodiment discloses a method for preparing a stain-resistant coating, including the following steps:

[0080] S1: 4.5 g of perfluoropolyether carboxylic acid and 3.5 mL of fluorocarbon solvent were added to a container, followed by 0.205 mL of pyridine. The mixture was heated to 74 °C and stirred for 14 min. Then, 2.8 mL of thionyl chloride was added and the mixture was stirred for another 10 h. After stirring, the mixture was distilled under reduced pressure, and 0.28 g of pentaerythritol triacrylate was added. The mixture was heated to 55 °C and reacted for 24 h to obtain compound 1.

[0081] S2: 4.5g magnesium powder, 37.38g methyltriethoxysilane, 0.118g iodine powder and 240mL tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated to 70℃. Then 43g 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred for 24h, then cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2.

[0082] S3: Add 3.5g of compound 1 and 4.5mL of fluorocarbon solvent to a container, then add 0.55g of compound 2, stir and react for 45min, then continue to heat at 55℃ for 12h, then cool to room temperature, wash, dissolve, separate the liquids to obtain the stain-resistant coating.

[0083] This example discloses a method for preparing a high-strength, stain-resistant melamine decorative panel, including the following steps:

[0084] Step 1: Add 5.5g of melamine and 2.5g of nano-reinforcing agent to 270mL of distilled water and stir for 3 hours to obtain a mixed emulsion. Place the impregnated paper into the mixed emulsion and soak for 12 hours. Remove the paper to obtain the composite impregnated paper.

[0085] Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, and then place it on the press. Use a hot pressing method with high temperature and short cycle and low temperature and long cycle. Set the pressure to 2MPa, the temperature to 180℃, and the hot pressing time to 45s per sheet. Cool to obtain melamine-containing decorative panel.

[0086] Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and dry it at 55℃ for 24 hours to obtain a high-strength stain-resistant melamine decorative panel.

[0087] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not add L-lactide during the preparation of the nano-reinforcing agent, and all other conditions remained unchanged.

[0088] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add perfluoropolyether carboxylic acid during the preparation of the stain-resistant coating, and all other conditions remained unchanged.

[0089] Comparative Example 3: Compared with Example 1, Comparative Example 3 did not add nano-reinforcing agents in the process of preparing high-strength stain-resistant melamine decorative panels, and all other conditions remained unchanged.

[0090] Comparative Example 4: Compared with Example 1, Comparative Example 4 did not add a stain-resistant coating during the preparation of high-strength stain-resistant melamine decorative panels, and all other conditions remained unchanged.

[0091] Experimental Example: The high-strength, stain-resistant melamine decorative panels prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to performance tests. The strength and stain resistance of the samples were tested according to GB / T 17657-2013. The test results are shown in Table 1.

[0092] Table 1

[0093]

[0094]

[0095] According to the stain resistance test, when the material grade is 5, it indicates no significant change in the material surface; when the material grade is 4, there is a slight change in the surface gloss and / or color; when the material grade is 3, there is a moderate change in the surface gloss and / or color; when the material grade is 2, there is a significant change in the surface gloss and / or color; and when the material grade is 1, the surface deforms and / or blisters. As shown in Table 1, the melamine decorative panels prepared in Examples 1-5 of this invention have excellent strength and stain resistance. Comparison of Comparative Example 1 and Examples 1-5 shows that adding L-lactide can effectively improve the strength of melamine decorative panels; comparison of Comparative Example 2 and Examples 1-5 shows that adding perfluoropolyether carboxylic acid can effectively improve the stain resistance of melamine decorative panels; comparison of Comparative Example 3 and Examples 1-5 shows that adding nano-reinforcing agents can effectively improve the strength of melamine decorative panels; comparison of Comparative Example 4 and Examples 1-5 shows that adding stain-resistant coatings can effectively improve the stain resistance of melamine decorative panels.

[0096] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0097] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a high-strength, stain-resistant melamine decorative panel, characterized in that, Includes the following steps: Step 1: Add melamine and nano-reinforcing agent to distilled water, stir and mix evenly to obtain a mixed emulsion, immerse the impregnated paper in the mixed emulsion, remove it, and obtain composite impregnated paper; Step 2: Select hard fiberboard as the substrate, place the composite impregnated paper flat on the substrate surface, then place it on a press, hot press, and cool to obtain a melamine-containing decorative panel; Step 3: Spray a stain-resistant coating onto the surface of the melamine decorative panel and let it dry to obtain a high-strength, stain-resistant melamine decorative panel; The preparation method of the nano-reinforcing agent includes the following steps: Q1: Cellulose nanocrystals were added to a container containing dimethyl sulfoxide, then L-lactide was added, and the mixture was heated under a nitrogen atmosphere. Stannous octoate was then added, and the reaction was carried out. After the reaction was completed, the precipitate was collected, centrifuged, washed, and vacuum dried to obtain the complex. Q2: Calcium chloride and ammonia water are mixed and stirred, then distilled water is added to obtain a mixed solution. Subsequently, the mixed solution, hexadecyltrimethylammonium bromide, n-butanol and cyclohexane are mixed and stirred. Sucrose is added during the mixing and stirring process to obtain a mixed emulsion. Carbon dioxide is bubbled into the mixed emulsion and the reaction is stirred continuously until no more precipitate is formed. The carbon dioxide bubbling is stopped, and the mixture is allowed to stand for aging, washed, centrifuged, and dried to obtain nanoparticles. The complex and nanoparticles are added to a container containing a mixed solution of chloroform and petroleum ether, stirred and mixed, allowed to stand, dried, and ball-milled to obtain a nano-reinforcing agent. In Q1, the ratio of cellulose nanocrystals, dimethyl sulfoxide, L-lactide, and stannous octoate is (0.3-0.5) g: (8-12) mL: (9-15) g: (0.09-0.15) g. When the system temperature is 128-135℃, stannous octoate is added, the reaction time is 18-24 h, methanol is added for precipitation, the centrifugation speed is 8000-12000 rpm, the time is 8-12 min, the system is washed with methanol and chloroform, and the system is vacuum dried at 40-50℃ for 24-36 h. The method for preparing the stain-resistant coating includes the following steps: S1: Perfluoropolyether carboxylic acid and fluorocarbon solvent were added to a container, followed by the addition of pyridine. After heating and stirring, thionyl chloride was added dropwise and stirring was continued. After stirring was completed, the mixture was distilled under reduced pressure, and pentaerythritol triacrylate was added. The mixture was then heated to react and give compound 1. S2: Magnesium powder, methyltriethoxysilane, iodine powder and tetrahydrofuran were added to a container, nitrogen gas was introduced, and the oil bath was heated. Then 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene was added dropwise to the container through a constant pressure dropping funnel. After the addition was complete, the mixture was stirred, cooled, distilled, and extracted with n-hexane. The mixture was filtered, concentrated by distillation, and distilled under reduced pressure to obtain compound 2. S3: Add compound 1 and fluorocarbon solvent to a container, then add compound 2, stir the reaction, continue to heat the reaction, then cool to room temperature, wash, dissolve, separate the liquids to obtain a stain-resistant coating.

2. The method for preparing the high-strength, stain-resistant melamine decorative panel according to claim 1, characterized in that, In step one, the ratio of melamine, nano-reinforcing agent, and distilled water is (4-6) g: (1-3) g: (250-280) mL, the stirring time is 2-3 h, and the soaking time is 8-12 h; in step two, a hot pressing method with high temperature and short cycle and low temperature and long cycle is adopted, with a pressure of 2-3 MPa, a temperature of 160-200℃, and a hot pressing time of 30-60 s per sheet; in step three, the drying temperature is 45-55℃, and the time is 18-24 h.

3. The method for preparing the high-strength, stain-resistant melamine decorative panel according to claim 1, characterized in that, In Q2, the ratio of calcium chloride, ammonia, and distilled water is (1.23-1.62) g: (0.9-1.2) g: (10-12) mL, and the volume ratio of the mixed solution, hexadecyltrimethylammonium bromide, n-butanol, and cyclohexane is (2-4): (50-75): (8-14): (15-25). The flow rate of carbon dioxide is 300 mL / min, the aging time is 12-15 h, the solution is washed with ethanol, and the drying temperature is 70-80℃ for 24-32 h. The ratio of the composite, nanoparticles, chloroform, and petroleum ether is (3-5) g: (1-1.2) g: (6-8) mL: (4-6) mL, the mixing and stirring time is 20-24 h, the drying temperature is 35-38℃ for 32-36 h.

4. The method for preparing the high-strength, stain-resistant melamine decorative panel according to claim 1, characterized in that, In S1, the ratio of perfluoropolyether carboxylic acid, fluorocarbon solvent, pyridine, thionyl chloride and pentaerythritol triacrylate is (3-5) g: (3-5) mL: (0.19-0.21) mL: (2-3) mL: (0.2-0.3) g. The heating and stirring temperature is 70-74℃, the stirring time is 10-14 min, the stirring time is 6-10 h, the heating reaction temperature is 45-55℃, and the time is 24-28 h.

5. The method for preparing the high-strength, stain-resistant melamine decorative panel according to claim 1, characterized in that, In S2, the ratio of magnesium powder, methyltriethoxysilane, iodine powder, tetrahydrofuran, and 4-bromo-2-fluoro-1-trifluoroethyleneoxybenzene is (4.2-4.6) g : (37.11-37.45) g : (0.1-0.12) g : (200-250) mL : (38-45) g, the oil bath temperature is 60-70℃, and the stirring time is 20-24 h.

6. The method for preparing the high-strength, stain-resistant melamine decorative panel according to claim 1, characterized in that, In S3, the ratio of compound 1, fluorocarbon solvent and compound 2 is (2-4) g: (2-5) mL: (0.4-0.6) g, the stirring reaction time is 30-45 min, the heating reaction temperature is 50-60℃, and the reaction time is 10-12 h.

7. A high-strength, stain-resistant melamine decorative panel, characterized in that, Prepared by the method described in any one of claims 1-6.

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