Preparation process of environment-friendly ENF-grade fireproof plate

Abstract

According to the preparation process of the environment-friendly ENF-grade fireproof plate, firstly, glue solution urea-formaldehyde resin and melamine formaldehyde resin are modified, then the glue solution urea-formaldehyde resin and the melamine formaldehyde resin are mixed according to the proportion of 5: 5 to form mixed glue solution, and the prepared fireproof plate is good in surface abrasion resistance and bonding strength. And the plant negative oxygen ion extracting solution is added, so that the prepared fireproof plate has the effects of reducing aldehyde and releasing negative oxygen ions. Then, chitosan is used for modifying glass fibers, then the adhesive film paper, the non-woven fabric and the modified glass fibers are impregnated, the fireproof plate can release formaldehyde capable of being volatilized under the high-temperature effect of hot pressing, and the remaining formaldehyde is purified through the formaldehyde purifying function of the newly-added plant negative oxygen ion extracting solution; and finally, the formaldehyde emission of the produced fireproof plate reaches the ENF level.

Description

An environmentally friendly E NF Manufacturing process of fireproof board Technical Field

[0001] This invention belongs to the field of fireproof board processing technology, and relates to a fireproof board, particularly an environmentally friendly E-type fireproof board. NF The manufacturing process of Class A fireproof boards. Background Technology

[0002] Polymer materials are widely used in all aspects of production and daily life, but at the same time, fires caused by the flammability of polymer materials have resulted in significant casualties and economic losses. Fireproof boards are fire-resistant building materials used for surface decoration, widely applied in interior decoration, furniture, kitchen cabinets, laboratory countertops, and exterior walls. There are many types of fireproof boards, among which phenolic fireproof boards are considered to have satisfactory performance and competitive costs, thus possessing broad application prospects. With increasing demands for building safety, the demand for building materials with special properties is growing. Fiber-reinforced fireproof boards are a type of partition wall material with a high fire resistance limit, typically used in the construction of special fire protection systems such as high-rise buildings, tunnels, and fire-resistant air ducts. These boards require high overall performance in terms of mechanical properties, high-temperature weather resistance, and fire resistance.

[0003] Urea-formaldehyde (UF) resin adhesive is the most widely used and consumed adhesive in the wood industry. Currently, the main problems in the application of UF resin adhesive are: high free formaldehyde content, poor hot water resistance, high brittleness, and poor aging resistance. The main improvement measures include: using a low molar ratio formulation, improving the synthesis process, and adding various modifiers. It is necessary to add a modifier to the system to improve the crosslinking degree of the UF resin. Melamine-formaldehyde resin (MF) has higher hardness than urea resin, is less flammable, has good moisture resistance, heat resistance, and chemical corrosion resistance, and possesses good gloss and mechanical strength. After curing, the adhesive is colorless, does not produce opacity, and has strong abrasion resistance. Melamine-formaldehyde resin can be used in the wood industry to make veneer decorative materials, mainly as the resin impregnating agent for the surface paper of decorative paper veneer panels. Melamine-formaldehyde resin has a low free formic acid release and good fire-retardant properties.

[0004] This invention utilizes nano-magnesium carbonate to modify urea-formaldehyde resin, resulting in reduced free formaldehyde content and increased viscosity. KH550, an excellent inorganic particle surface modifier, is used to modify the surface of nano-CaCO3 before treating the melamine-formaldehyde resin, giving the resin good storage stability and flowability. Modified glass fibers, specifically chitosan-modified glass fibers, are added between the paper base. Chitosan is a natural cationic polymer, non-toxic, with good biocompatibility and biodegradability, and will not cause secondary pollution. Furthermore, plant negative ion extract is added to the adhesive solution, enabling the fireproof board to reduce formaldehyde and release negative ions, ultimately achieving a formaldehyde emission level that meets the national standard E. NF class. Summary of the Invention

[0005] To address the above problems, this invention prepares an environmentally friendly E NF This fire-resistant board uses nano-magnesium carbonate modified urea-formaldehyde resin, with KH550 used for surface modification of nano-CaCO3. The treated nano-CaCO3 is then used to treat melamine-formaldehyde resin. Chitosan-modified glass fiber is selected, and plant negative oxygen ion extract is added to the adhesive. After high-temperature hot pressing, some of the formaldehyde in the impregnated paper will volatilize, ultimately producing an environmentally friendly E-grade fire-resistant board. NF Grade A fireproof board.

[0006] In a first aspect, the present invention provides an environmentally friendly E NF The manufacturing process of Class A fireproof boards, specifically the following steps:

[0007] S1. Preparation of modified urea-formaldehyde resin: Add 200-250 mL of a 36.5-37.5% formaldehyde solution to a 500 mL four-necked flask. Adjust the pH of the formaldehyde solution to 8-9 using a 30% NaOH solution. Then place the four-necked flask in a water bath, heat to 40-50℃ and maintain the temperature for 10-20 min. At this time, add 10 g of urea to the four-necked flask and start heating. Heat the reaction system to about 90-100℃ and maintain the temperature for 40-50 min. Then adjust the pH of the reaction solution to 5-6 using a 50% formic acid solution, and maintain the reaction temperature at 85-95℃ (during the reaction process). In this process, a dropper is used to draw up the urea-formaldehyde resin solution (reaction solution) and add it to water, while the degree of reaction is measured in real time. When the resin produces a persistent white mist in the water, the reaction temperature is lowered to approximately 80°C. Then, the pH is adjusted to 6-7 with a 30% NaOH solution, and 10-20 mg of urea is added. The reaction is allowed to proceed for 20-30 minutes. Next, the pH is adjusted to 8-9 with another 30% NaOH solution, and 10-20 mg of urea and 4-8 mg of nano-MgCO3 are added. The mixture is stirred continuously to dissolve the urea and ensure uniform dispersion of the nano-MgCO3. Finally, the urea-formaldehyde resin is cooled to room temperature before being discharged to obtain the modified urea-formaldehyde resin. In this step, nano-magnesium carbonate exhibits strong adsorption capacity, performing both physical and chemical adsorption on formaldehyde, forming covalent bonds with it, thereby reducing the free formaldehyde content in the resin. Furthermore, nano-magnesium carbonate forms van der Waals forces with the amino groups of the urea-formaldehyde resin, increasing intermolecular forces and thus increasing the resistance to relative flow within the fluid, resulting in increased viscosity.

[0008] S2. Treatment of melamine-formaldehyde resin: Pour 5g of nano-CaCO3 into a flask equipped with a condenser, then add 500ml of water and anhydrous ethanol in a 1:1 volume ratio. Stir mechanically, adjust the pH to 9-11 using 30% NaOH solution, and heat to 80-90℃. Add 1g of coupling agent KH550 and react for 40-50 minutes. Then centrifuge at 4000r / min for 5-8 minutes. Dry the product at 80℃ and grind it to obtain surface-modified nano-CaCO3. 3. Place 100ml of melamine-formaldehyde resin in an Erlenmeyer flask, add 15ml of anhydrous ethanol, and continuously stir the solution at room temperature using a digital display constant-temperature magnetic stirrer until the solution is uniform and transparent. Then add 5-10mg of sodium alginate suspending agent. After the suspending agent is fully dissolved, stop the magnetic stirring, add 20-30mg of surface-modified nano-CaCO3, and stir magnetically for 10 minutes. Then, use ultrasonic dispersion to ensure uniform dispersion of the nano-CaCO3. Finally, discharge the melamine-formaldehyde resin to obtain the treated melamine-formaldehyde resin. In this step, KH550 is a good inorganic particle surface modifier. It modifies the surface of nano-CaCO3, giving nano-calcium carbonate a large specific surface area and high surface free energy. This results in nano-calcium carbonate having a very strong tendency to aggregate, forming agglomerates that enter the melamine-formaldehyde resin, giving the resin good storage stability and good flowability.

[0009] S3. Modified Glass Fiber: Weigh 21-31g of glass fiber precursor and treat it in a muffle furnace at 500-600℃ for 1-2 hours to remove the surface wetting agent. Immerse it in a 0.5-2mg / ml chitosan aqueous solution and stir continuously during ultrasonic dispersion. Transfer it to a shaker and carry out the coating reaction under shaking for 24 hours. Finally, filter and wash the glass fiber multiple times, and vacuum dry it at 95-105℃ to obtain chitosan-modified glass fiber. In this step, chitosan is a natural cationic polymer that is non-toxic, has good biocompatibility and biodegradability, and will not cause secondary pollution. The chitosan structure contains a large number of -NH2 and -OH groups. The main component of glass fiber is silicon dioxide, which forms hydrogen bonds or van der Waals forces with the -NH2 and -OH groups of chitosan, thereby improving the impact strength of the fireproof board. This modified glass fiber has wide application value in reinforcing fireproof boards.

[0010] S4, Preparation of environmentally friendly E NFImpregnated film paper for fire-resistant boards: First, the decorative base paper is impregnated in a 5:5 mixture of modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2. The impregnation solution in the impregnation tank is a mixture of the modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2 in a 5:5 ratio. The mixture contains 3.0% softener (dimethyl silicate), 3-5‰ penetrant (JFC-M), and 5.0‰ curing agent (polyacrylamide). The percentages are based on the proportions in the mixture. The viscosity at 25°C (using a 4-cup coater) is 15-16 seconds. The curing time is controlled at approximately 15 minutes and 30 seconds. The impregnation amount is 60-65 g / m². 2 After drying, the product undergoes a three-stage drying oven at 133-138℃ for the first drying stage. Following the first drying, it proceeds to the next step of applying adhesive. The adhesive used is the melamine-formaldehyde resin treated in step S2, and additives are added to the treated melamine-formaldehyde resin. The additive ratios are as follows: Curing agent (polyacrylamide): 5.0-6.0‰, Penetrant (JFC-M): 1.0‰, Release agent (polyethylene glycol): 3.0‰, Dust remover (polytetrafluoroethylene micro powder): 2‰, Softener (dimethyl silicate): 3.0%, Plant negative oxygen ion extract: 5-8%. The plant negative oxygen ion extract contains the following components by weight: 60-65 parts small molecule silicon water, 20-25 parts rare crystal, 5-8 parts Rhodiola rosea, 2-5 parts Phellodendron amurense, 2-5 parts Atractylodes lancea, and 1-3 parts Mentha haplocalyx. This plant-derived negative ion extract can increase the release of negative ions from materials and also has the function of purifying formaldehyde; the adhesive is applied to the upper and lower surfaces by a set of smooth rollers and extrusion rollers on each side, with a total adhesive content of 55g / m². 2 The difference in the amount of adhesive on the upper and lower surfaces is controlled within 5g. After scraping off the excess adhesive on the edge, the paper enters a five-stage drying oven at 133-138℃ to complete the second drying. After cooling, the paper is rewound by the rewinding roller.

[0011] S5, Preparation of environmentally friendly E NFFire-resistant board: The equipment layout sketch for the fire-resistant board production process is shown in Figure 1. In the figure, 1 is the unwinding device, 2 is the double steel belt press, 3 is the cooling device, 4 is the release paper winding device, 5 is the sanding device, 6 is the edge trimming device, 7 is the CPL winding device, 8 is the cutter (sheet CPL cutter), and 9 is the sheet CPL stacking device. The rewound impregnated paper prepared in step S4, the three layers of modified glass fiber from step S3, and the three layers of non-woven fabric are respectively fed onto the unwinding device of the fire-resistant board production line. The order of the impregnated paper and non-woven fabric is determined according to the finish type; generally, the textured non-woven fabric is on top of the impregnated paper, and other finish non-woven fabrics are on top of the impregnated paper. Below the impregnated paper, the unwinding device has a total of 8 unwinding shafts. The feeding device is shown in Figure 2. After the rewound impregnated paper, the three layers of glass fiber modified in step S3 and the non-woven fabric are stacked, they are fed into the fireproof board line double steel belt press to complete the bonding. The heating method is hot oil heating. The roller pressing steel belt pressure is increased by hydraulic oil through a pressure pump. The temperature points: SEK1, SEK2, SEK3 and SEK5 are 185℃-190℃, 185℃-190℃, 180℃-185℃ and 185℃-190℃ respectively. The pressure is 15-17 bar and the traction speed is controlled at 20-25 m / min. The laminated surface material is the fireproof board. After exiting the press, the fireproof board enters the roller cooling station and the release paper winding device (see Figure 3). The release paper winding device is used to wind up the release paper for other surface types besides glossy and matte finishes, facilitating the reuse of the release paper. After cooling in the roller cooling station, the laminated fireproof board passes through a sanding device (see Figure 4) and then enters the CPL rewinding device (see Figure 5) to complete the rewinding, thus obtaining an E-type fireproof board. NF CPL fire-resistant decorative material. In this step, sanding is generally not used unless specifically required. Modified glass fibers (from step S3) are added to the middle of the prepared fire-resistant board paper base for reinforcement. The modified glass fibers make the original paper adhere better, thus giving the fire-resistant board better mechanical properties and durability. Plant negative oxygen ion extract is added to the adhesive solution, enabling the fire-resistant board to reduce formaldehyde and release negative oxygen ions. After impregnation with adhesive, the paper undergoes a three-stage oven drying process, followed by a five-stage oven drying process after coating with adhesive. This ensures that the volatile matter and pre-curing degree of the impregnated paper reach the target values: volatile matter: 7.0-8.0%, pre-curing degree: 25-40%. These two indicators may vary slightly depending on the paper pattern, but are generally controlled within the above range. After adhesive coating, some moisture is removed from the paper, and the adhesive is pre-cured. Following high-temperature hot pressing, some of the formaldehyde contained in the impregnated paper will volatilize, while the remaining portion will be decomposed and absorbed by plant-based negative ion additives, thereby reducing the formaldehyde release of the fireproof board. The final fireproof board achieves a formaldehyde release rating that meets the national standard E. NF class.

[0012] Preferably: In step S1, 200 mL of a 36.5% formaldehyde solution is added to a 500 mL four-necked flask, and the pH of the formaldehyde solution is adjusted to 8 using a 30% NaOH solution;

[0013] Preferably: In step S1, the four-necked flask is placed in a water bath, heated to 40°C, and kept at that temperature for 10 minutes;

[0014] Preferably, in step S2, a 30% NaOH solution is used to adjust the pH value to 9;

[0015] Preferably, 5 mg of sodium alginate, a suspending agent, is added in step S2;

[0016] Preferably: 21g of glass fiber filament is weighed in step S3;

[0017] Preferably, a 0.5 mg / ml chitosan aqueous solution is added in step S3;

[0018] Preferably, in step S4, 8% of plant negative oxygen ion extract is added;

[0019] Secondly, the present invention provides the aforementioned environmentally friendly E NF The fireproof board is prepared using the same manufacturing process as the grade A fireproof board.

[0020] The technological advancements achieved by this invention due to the adoption of the above technical solution are as follows:

[0021] 1. This invention prepares an environmentally friendly E NF For the fire-resistant board, the modified urea-formaldehyde resin prepared in step S1 and the melamine-formaldehyde resin treated in step S2 are mixed in a 5:5 ratio in an impregnation tank. Nano-magnesium carbonate modifies the urea-formaldehyde resin, reducing the free formaldehyde content and increasing the viscosity. KH550, a good inorganic particle surface modifier, is used to modify the surface of nano-CaCO3, which is then incorporated into the melamine-formaldehyde resin, giving the resin good storage stability and good flowability.

[0022] 2. The modified urea-formaldehyde resin prepared in step S1 and the melamine-formaldehyde resin treated in step S2 have a synergistic effect on improving the mechanical properties of the fireproof board. When mixed in a 5:5 ratio as the adhesive, the fireproof board exhibits good wear resistance, good bonding strength, and formaldehyde release meets E... NF class.

[0023] 3. Preparation of environmentally friendly E NFIn the process of making fire-resistant boards, modified glass fibers are added between the paper base, with chitosan-modified glass fibers being selected. Chitosan is a natural cationic polymer that is non-toxic, has good biocompatibility and biodegradability, and will not cause secondary pollution. This modified glass fiber has wide application value in reinforcing fire-resistant boards.

[0024] 4. The prepared fireproof board is reinforced with modified glass fibers added to the middle of the paper base. The modified glass fibers make the impregnated paper adhere better, thus giving the fireproof board better mechanical properties and durability. Plant negative oxygen ion extract is added to the adhesive to reduce formaldehyde and release negative oxygen ions. After impregnation, the board undergoes a three-stage oven drying process, followed by a five-stage oven drying process after coating. This ensures that the volatile matter and pre-curing degree of the impregnated paper reach the target values: volatile matter: 7.0-8.0%, pre-curing degree: 25-40%. These two indicators may deviate slightly depending on the paper pattern, but are generally controlled within the above range. After high-temperature hot pressing, some of the formaldehyde in the impregnated paper will volatilize, while the remaining portion will be decomposed and absorbed by the plant negative oxygen ion additive, thereby reducing the formaldehyde release of the fireproof board. The final fireproof board meets the national standard E for formaldehyde release. NF class. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 is a sketch of the equipment layout used in the production process of the fireproof board of the present invention.

[0027] Figure 2 is a diagram of the winding feeding device of the present invention.

[0028] Figure 3 shows the fireproof board of the present invention entering the roller cooling station and release paper winding device after exiting the press.

[0029] Figure 4 shows the fireproof board of the present invention after being cooled by a roller cooling station and passing through a sanding device.

[0030] Figure 5 is a diagram of the CPL rewinding device of the present invention.

[0031] Figure 6 shows the effect of illumination time on the free formaldehyde content of urea-formaldehyde resin in Example 1 and Comparative Example 1 under natural light.

[0032] Figure 7 is a TEM image of the dispersion of nano-CaCO3 in anhydrous ethanol in the organic phase before surface modification with KH550 in Example 2 of the present invention.

[0033] Figure 8 is a TEM image of the dispersion of nano-CaCO3 in anhydrous ethanol in the organic phase after surface modification with KH550 in Example 2 of the present invention.

[0034] Figure 9 shows the effect of the modified glass fibers prepared in Example 3 and Comparative Example 4 of this invention on impact performance. Detailed Implementation

[0035] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the content of this invention and are not intended to limit this invention.

[0036] Example 1

[0037] This embodiment provides an environmentally friendly E NF The manufacturing process of the Class A fireproof board is as follows:

[0038] S1. Preparation of modified urea-formaldehyde resin: Add 200 mL of 36.5% formaldehyde solution to a 500 mL four-necked flask, and adjust the pH of the formaldehyde solution to 8 using 30% NaOH solution; then place the four-necked flask in a water bath, heat to 40℃ and maintain the temperature for 10 min; at this time, add 10 g of urea to the four-necked flask and start heating, raising the reaction system to about 90℃ and maintaining the temperature for 40 min; then adjust the pH of the reaction solution to 5 using 50% formic acid solution, and maintain the reaction temperature at 85℃ (using a dropper head during the reaction). A tube is used to draw urea-formaldehyde resin solution (reaction solution) and add it to water, with the degree of reaction measured in real time. When the resin produces a persistent white mist in the water, the reaction temperature is lowered to approximately 80°C. The pH is then adjusted to 6 with a 30% NaOH solution, and 10 mg of urea is added, reacting for 20 minutes. The pH is then adjusted to 8 with another 30% NaOH solution, and 10 mg of urea and 4 mg of nano-MgCO3 are added, stirring continuously to dissolve the urea and evenly disperse the nano-MgCO3. Finally, the urea-formaldehyde resin is cooled to room temperature before being discharged to obtain the modified urea-formaldehyde resin. In this step, nano-magnesium carbonate exhibits strong adsorption capacity, performing both physical and chemical adsorption on formaldehyde, forming covalent bonds with it, thereby reducing the free formaldehyde content in the resin. Furthermore, nano-magnesium carbonate forms van der Waals forces with the amino groups of the urea-formaldehyde resin, increasing intermolecular forces and thus increasing the resistance to relative flow within the fluid, resulting in increased viscosity.

[0039] S2. Treatment of melamine-formaldehyde resin: Pour 5g of nano-CaCO3 into a flask equipped with a condenser, then add 500ml of water and anhydrous ethanol in a 1:1 volume ratio. Stir mechanically, adjust the pH to 9 using 30% NaOH solution, and heat to 80℃. Add 1g of coupling agent KH550 and react for 40-50 minutes. Then centrifuge at 4000r / min for 5 minutes. Dry the obtained product at 80℃ and grind to obtain surface-modified nano-CaCO3. Take 100ml of... Melamine-formaldehyde resin (purchased from Shandong Jiaying Chemical Technology Co., Ltd.) was placed in an Erlenmeyer flask, and 15 ml of anhydrous ethanol was added. The mixture was continuously stirred at room temperature using a digital display constant-temperature magnetic stirrer until the solution was uniform and transparent. Then, 5 mg of sodium alginate suspending agent was added. After the suspending agent was fully dissolved, magnetic stirring was stopped. 20 mg of surface-modified nano-CaCO3 was added, and the mixture was magnetically stirred for 10 minutes. Following this, ultrasonic dispersion was performed to ensure uniform dispersion of the nano-CaCO3. Finally, the melamine-formaldehyde resin was discharged to obtain the treated melamine-formaldehyde resin. In this step, KH550 is a good inorganic particle surface modifier. Surface modification of the nano-CaCO3 gives the nano-calcium carbonate a large specific surface area and high surface free energy, resulting in a strong tendency for the nano-calcium carbonate to aggregate. This aggregates then enter the melamine-formaldehyde resin, giving the resin good storage stability and good flowability.

[0040] S3. Modified Glass Fiber: Weigh 21g of glass fiber precursor (purchased from Shandong Taicheng Fiber Co., Ltd.), treat the glass fiber precursor in a muffle furnace at 500℃ for 1 hour to remove the surface wetting agent, immerse it in a 0.5mg / ml chitosan aqueous solution, and stir continuously while ultrasonically dispersing. Transfer it to a shaker and carry out the coating reaction under shaking for 24 hours. Finally, filter and wash the above glass fiber multiple times, and vacuum dry it at 95℃ to obtain chitosan-modified glass fiber. In this step, chitosan is a natural cationic polymer, non-toxic, with good biocompatibility and biodegradability, and will not cause secondary pollution. The chitosan structure contains a large number of -NH2 and -OH groups. The main component of glass fiber is silicon dioxide, which forms hydrogen bonds or van der Waals forces with the -NH2 and -OH groups of chitosan, thereby improving the impact strength of the fireproof board. This modified glass fiber has wide application value for reinforcing fireproof boards.

[0041] S4, Preparation of environmentally friendly E NFImpregnated film paper for fire-resistant boards: First, the decorative base paper for the finish is impregnated in a 5:5 mixture of modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2. The impregnation solution in the impregnation tank is a mixture of the modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2 in a 5:5 ratio. The mixture contains 3.0% softener (dimethyl silicate), 3‰ penetrant (JFC-M), and 5.0‰ curing agent (polyacrylamide). The percentages are based on the proportions in the mixture. The viscosity at 25°C (using a 4-cup coater) is 15 seconds. The curing time for one impregnation is controlled to be around 15 minutes and 30 seconds. The impregnation amount is 60 g / m². 2 After drying, the product undergoes a three-stage drying oven at 133℃ for the first drying stage. After the first drying stage, the product proceeds to the next step of applying adhesive. The adhesive used for applying the adhesive is the melamine-formaldehyde resin treated in step S2. Additives are also added to the treated melamine-formaldehyde resin. The additive ratio is as follows: the percentage content is based on the proportion of the treated melamine-formaldehyde resin: curing agent (polyacrylamide): 5.0‰, penetrant (JFC-M): 1.0‰, release agent (polyethylene glycol): 3.0‰, dust remover (polytetrafluoroethylene micro powder): 2‰, softener (dimethyl silicate): 3.0%, and plant negative oxygen ion extract: 5%. The plant negative oxygen ion extract contains the following components by weight: 60 parts small molecule silicon water, 20 parts rare crystal stone, 5 parts Rhodiola rosea, 2 parts Phellodendron amurense, 2 parts Atractylodes lancea, and 1 part Mentha haplocalyx. This plant-derived negative ion extract can increase the release of negative ions from materials and also has the function of purifying formaldehyde; the adhesive is applied to the upper and lower surfaces by a set of smooth rollers and extrusion rollers on each side, with a total adhesive content of 55g / m². 2 The difference in the amount of glue on the upper and lower surfaces is controlled within 5g. After scraping off the excess glue on the edge, the paper enters a five-stage drying oven at 133℃ to complete the second drying. After cooling, the paper is rewound by the rewinding roller.

[0042] S5, Preparation of environmentally friendly E NFFire-resistant board: The equipment layout sketch for the fire-resistant board production process is shown in Figure 1. In the figure, 1 is the unwinding device, 2 is the double steel belt press, 3 is the cooling device, 4 is the release paper winding device, 5 is the sanding device, 6 is the edge trimming device, 7 is the CPL winding device, 8 is the cutter (sheet CPL cutter), and 9 is the sheet CPL stacking device. The rewound impregnated paper prepared in step S4, the three layers of glass fiber modified in step S3, and the three layers of non-woven fabric are respectively fed onto the unwinding device of the fire-resistant board production line. The order of the impregnated paper and non-woven fabric is determined according to the finish type; generally, the textured non-woven fabric is added first during impregnation. Above the impregnated paper, other decorative nonwoven fabrics are below the impregnated paper. The unwinding device has a total of 8 unwinding shafts. The winding device is shown in Figure 2. After the rewinding impregnated paper, the three layers of glass fiber modified in step S3 and the nonwoven fabric are stacked, they are put into the fireproof board line double steel belt press to complete the bonding. The heating method is hot oil heating. The roller pressing steel belt pressure is increased by hydraulic oil through a pressurizing pump. The temperature points: SEK1, SEK2, SEK3 and SEK5 are 185℃, 185℃, 180℃ and 185℃ respectively. The pressure is 15 bar and the traction speed is controlled at 20m / min. The laminated surface material is the fireproof board. After exiting the press, the fireproof board enters the roller cooling station and the release paper winding device (see Figure 3). The release paper winding device is used to wind up the release paper for other surface types besides glossy and matte finishes, facilitating the reuse of the release paper. After cooling in the roller cooling station, the laminated fireproof board passes through a sanding device (see Figure 4) and then enters the CPL rewinding device (see Figure 5) to complete the rewinding, thus obtaining an E-type fireproof board. NF CPL fire-resistant decorative material. In this step, sanding is generally not used unless specifically required. Modified glass fibers (from step S3) are added to the middle of the prepared fire-resistant board paper base for reinforcement. The modified glass fibers make the original paper adhere better, thus giving the fire-resistant board better mechanical properties and durability. Plant negative oxygen ion extract is added to the adhesive solution, enabling the fire-resistant board to reduce formaldehyde and release negative oxygen ions. After impregnation with adhesive, the paper undergoes a three-stage oven drying process, followed by a five-stage oven drying process after adhesive coating. This ensures that the volatile matter and pre-curing degree of the impregnated paper reach the target values: volatile matter: 7.0%, pre-curing degree: 25%. Depending on the paper pattern, these two indicators may deviate to some extent, but are generally controlled within the above range. After adhesive coating, some moisture is removed from the paper, and the adhesive is pre-cured. Following high-temperature hot pressing, some of the formaldehyde contained in the impregnated paper will volatilize, while the remaining portion is decomposed and absorbed by plant-based negative oxygen ion additives, thereby reducing the formaldehyde release of the fireproof board. The final fireproof board meets the national standard E... NF class.

[0043] Comparative Example 1: Step S1 was the same as in Example 1 except that nano-MgCO3 was not added to modify the urea-formaldehyde resin.

[0044] The performance of the urea-formaldehyde resins obtained in step S1 of Example 1 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0045] Table 1

[0046] Project Example 1 Comparative Example 1 Bond Strength / MPa 1.2±0.2 0.7±0.1 Viscosity / mPa·s 9 0.73±0.01 6 1.43±0.01 surface

[0047] Table 1 shows the effect of adding nano-MgCO3 and not adding nano-MgCO3 on the properties of urea-formaldehyde resin. The table shows that the urea-formaldehyde resin modified with nano-MgCO3 has higher viscosity and significantly higher bonding strength than pure urea-formaldehyde resin. This may be because nano-magnesium carbonate forms van der Waals forces with the amino groups of urea-formaldehyde resin, increasing intermolecular forces and thus increasing the resistance to relative flow of the resin within the fluid, resulting in increased viscosity. Figure 6 shows the effect of light exposure time on the free formaldehyde content of the urea-formaldehyde resins in Example 1 and Comparative Example 1 under natural light. As shown in the figure, the free formaldehyde content in urea-formaldehyde resin decreases with prolonged light exposure. However, because nano-MgCO3 absorbs more photoelectrons under light, it more effectively degrades free formaldehyde. In Example 1, after 12 hours of light exposure, the free formaldehyde content in the urea-formaldehyde resin was 0.42%, close to the 0.40% in Comparative Example 1 after 48 hours of light exposure. However, after 48 hours of light exposure, the free formaldehyde content in Example 1 was only 0.33%, compared to the initial 0.54%. This indicates that under light exposure, the nano-MgCO3 used in the modified urea-formaldehyde resin of Example 1 effectively degraded approximately 38.9% of the free formaldehyde in the resin. This is because nano-magnesium carbonate has a strong adsorption capacity, exhibiting both physical and chemical adsorption of formaldehyde, forming covalent bonds with it, thereby reducing the free formaldehyde content in the resin.

[0048] Example 2

[0049] This embodiment provides an environmentally friendly E NF The manufacturing process of the Class A fireproof board is as follows:

[0050] S1. Preparation of modified urea-formaldehyde resin: Add 210 mL of 36.8% formaldehyde solution to a 500 mL four-necked flask, and adjust the pH of the formaldehyde solution to 8 using 30% NaOH solution; then place the four-necked flask in a water bath, heat to 42℃ and maintain the temperature for 12 min; at this time, add 10 g of urea to the four-necked flask and start heating, raising the reaction system to about 92℃ and maintaining the temperature for 42 min; then adjust the pH of the reaction solution to 5 using 50% formic acid solution, and maintain the reaction temperature at 88℃ (using a dropper head during the reaction). A urea-formaldehyde resin solution (reaction solution) was drawn into a tube and added to water, with the degree of reaction measured in real time. When the resin produced a persistent white mist in the water, the reaction temperature was lowered to approximately 80°C. The pH was then adjusted to 6 with a 30% NaOH solution, and 12 mg of urea was added. The reaction was allowed to proceed for 22 minutes. The pH was then adjusted to 8 with another 30% NaOH solution, and 12 mg of urea and 5 mg of nano-MgCO3 were added. The mixture was continuously stirred to dissolve the urea and ensure uniform dispersion of the nano-MgCO3. Finally, the urea-formaldehyde resin was cooled to room temperature before being discharged to obtain the modified urea-formaldehyde resin. In this step, nano-magnesium carbonate exhibits strong adsorption capacity, performing both physical and chemical adsorption on formaldehyde, forming covalent bonds with it, thereby reducing the free formaldehyde content in the resin. Furthermore, nano-magnesium carbonate forms van der Waals forces with the amino groups of the urea-formaldehyde resin, increasing intermolecular forces and thus increasing the resistance to relative flow within the fluid, resulting in increased viscosity.

[0051] S2. Treatment of melamine-formaldehyde resin: Pour 5g of nano-CaCO3 into a flask containing a condenser, add 500ml of water and anhydrous ethanol in a 1:1 volume ratio, stir mechanically, adjust the pH to 10 using 30% NaOH solution, heat to 82℃, add 1g of coupling agent KH550, react for 42min, then centrifuge at 4000r / min for 6min, dry the product at 80℃, and grind to obtain surface-modified nano-CaCO3; 100 ml of melamine-formaldehyde resin was placed in an Erlenmeyer flask, and 15 ml of anhydrous ethanol was added. The mixture was continuously stirred at room temperature using a digital display constant-temperature magnetic stirrer until the solution was uniform and transparent. Then, 6 mg of sodium alginate suspending agent was added. After the suspending agent was fully dissolved, magnetic stirring was stopped. 22 mg of surface-modified nano-CaCO3 was added, and the mixture was magnetically stirred for 10 minutes. Following this, ultrasonic dispersion was performed to ensure uniform dispersion of the nano-CaCO3. Finally, the melamine-formaldehyde resin was discharged to obtain the treated melamine-formaldehyde resin. In this step, KH550 is a good inorganic particle surface modifier. Surface modification of the nano-CaCO3 gives the nano-calcium carbonate a large specific surface area and high surface free energy, resulting in a strong tendency for the nano-calcium carbonate to aggregate. This aggregates then enter the melamine-formaldehyde resin, giving the resin good storage stability and good flowability.

[0052] S3. Modified Glass Fiber: Weigh 24g of glass fiber precursor and treat it in a muffle furnace at 550℃ for 1.2h to remove the surface wetting agent. Immerse it in a 0.8mg / ml chitosan aqueous solution and stir continuously during ultrasonic dispersion. Transfer it to a shaker and carry out the coating reaction under shaking for 24h. Finally, filter and wash the glass fiber multiple times and vacuum dry it at 100℃ to obtain chitosan-modified glass fiber. In this step, chitosan is a natural cationic polymer that is non-toxic, has good biocompatibility and biodegradability, and will not cause secondary pollution. The chitosan structure contains a large number of -NH2 and -OH groups. The main component of glass fiber is silicon dioxide, which forms hydrogen bonds or van der Waals forces with the -NH2 and -OH groups of chitosan, thereby improving the impact strength of the fireproof board. This modified glass fiber has wide application value in reinforcing fireproof boards.

[0053] S4, Preparation of environmentally friendly E NF Impregnated film paper for fire-resistant boards: First, the decorative base paper for the finish is impregnated in a 5:5 mixture of modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2. The impregnation solution in the impregnation tank is a mixture of the modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2 in a 5:5 ratio. The mixture contains 3.0% softener (dimethyl silicate), 4‰ penetrant (JFC-M), and 5.0‰ curing agent (polyacrylamide). The percentages are based on the proportions in the mixture. The viscosity at 25°C (using a 4-cup coater) is 15 seconds. The curing time for one impregnation is controlled at approximately 15 minutes and 30 seconds. The impregnation amount is 62 g / m³. 2 After drying, the product undergoes a three-stage drying oven at 134℃ for the first drying stage. After the first drying stage, the product proceeds to the next step of applying adhesive. The adhesive used for applying the adhesive is the melamine-formaldehyde resin treated in step S2. The treated melamine-formaldehyde resin also contains additives. The additive ratio is as follows: the percentage content is based on the proportion of the treated melamine-formaldehyde resin: curing agent (polyacrylamide): 4.0‰, penetrant (JFC-M): 1.0‰, release agent (polyethylene glycol): 3.0‰, dust remover (polytetrafluoroethylene micro powder): 2‰, softener (dimethyl silicate): 3.0%, and plant negative oxygen ion extract: 6%. The plant negative oxygen ion extract contains the following components by weight: 62 parts small molecule silicon water, 22 parts rare crystal stone, 6 parts Rhodiola rosea, 3 parts Phellodendron amurense, 3 parts Atractylodes lancea, and 1 part Mentha haplocalyx. This plant-derived negative ion extract can increase the release of negative ions from materials and also has the function of purifying formaldehyde; the adhesive is applied to the upper and lower surfaces by a set of smooth rollers and extrusion rollers on each side, with a total adhesive content of 55g / m². 2The difference in the amount of adhesive on the upper and lower surfaces is controlled within 5g. After scraping off the excess adhesive on the edge, the paper enters a five-stage drying oven at 133-138℃ to complete the second drying. After cooling, the paper is rewound by the rewinding roller.

[0054] S5, Preparation of environmentally friendly E NF Fire-resistant board: The equipment layout sketch for the fire-resistant board production process is shown in Figure 1. In the figure, 1 is the unwinding device, 2 is the double steel belt press, 3 is the cooling device, 4 is the release paper winding device, 5 is the sanding device, 6 is the edge trimming device, 7 is the CPL winding device, 8 is the cutter (sheet CPL cutter), and 9 is the sheet CPL stacking device. The rewound impregnated paper prepared in step S4, the three layers of glass fiber modified in step S3, and the three layers of non-woven fabric are respectively fed onto the unwinding device of the fire-resistant board production line. The order of the impregnated paper and non-woven fabric is determined according to the finish type; generally, the textured non-woven fabric is added first during impregnation. Above the impregnated paper, other decorative nonwoven fabrics are below the impregnated paper. The unwinding device has a total of 8 unwinding shafts. The winding device is shown in Figure 2. After the rewinding impregnated paper, the three layers of glass fiber modified in step S3 and the nonwoven fabric are stacked, they are put into the fireproof board line double steel belt press to complete the bonding. The heating method is hot oil heating. The roller pressing steel belt pressure is increased by hydraulic oil through a pressure pump. The temperature points: SEK1, SEK2, SEK3 and SEK5 are 188℃, 188℃, 182℃ and 188℃ respectively. The pressure is 16 bar and the traction speed is controlled at 21m / min. The laminated surface material is the fireproof board. After exiting the press, the fireproof board enters the roller cooling station and the release paper winding device (see Figure 3). The release paper winding device is used to wind up the release paper for other surface types besides glossy and matte finishes, facilitating the reuse of the release paper. After cooling in the roller cooling station, the laminated fireproof board passes through a sanding device (see Figure 4) and then enters the CPL rewinding device (see Figure 5) to complete the rewinding, thus obtaining an E-type fireproof board. NFCPL fire-resistant decorative material. In this step, sanding is generally not used unless specifically required. Modified glass fibers (from step S3) are added to the middle of the prepared fire-resistant board paper base for reinforcement. The modified glass fibers make the original paper adhere better, thus giving the fire-resistant board better mechanical properties and durability. Plant negative oxygen ion extract is added to the adhesive solution, enabling the fire-resistant board to reduce formaldehyde and release negative oxygen ions. After impregnation with adhesive, the paper undergoes a three-stage oven drying process, followed by a five-stage oven drying process after coating with adhesive. This ensures that the volatile matter and pre-curing degree of the impregnated paper reach the target values: volatile matter: 7.2%, pre-curing degree: 26%. Depending on the paper pattern, these two indicators may deviate to some extent, but are generally controlled within the above range. After adhesive coating, some moisture remains in the paper, and the adhesive completes its pre-curing. Following high-temperature hot pressing, some of the formaldehyde contained in the impregnated paper will volatilize, while the remaining portion will be decomposed and absorbed by plant-based negative oxygen ion additives, thereby reducing the formaldehyde release of the fireproof board. The final fireproof board meets the national standard E... NF class.

[0055] Comparative Example 2: In step S2, except that KH550 was not used to modify the surface of the nano-CaCO3, the melamine-formaldehyde resin was directly treated with unmodified nano-CaCO3 (purchased from Hangzhou Hengge Nanotechnology Co., Ltd.), and everything else was the same as in Example 2.

[0056] Comparative Example 3: In step S2, except that no modified nano-CaCO3 was added to treat the melamine-formaldehyde resin, everything else was the same as in Example 2.

[0057] The physicochemical properties of the melamine-formaldehyde resins obtained in step S2 of Examples 2, 2, and 3 are shown in Table 2.

[0058] Table 2

[0059] Project Example 2 Comparative Example 2 Comparative Example 3 Curing Time / s 291.2±0.1 98.4±0.2 59.2±0.1 Shelf Life / d 90±2 71±1 62±1 Appearance Pale yellow transparent liquid Pale yellow transparent liquid Pale yellow transparent liquid surface

[0060] Figures 7 and 8 are TEM images of the dispersion of nano-CaCO3 in anhydrous ethanol before and after surface modification with KH550. Figure 8 shows that the particles are uniformly dispersed, with small particle sizes still within the nanometer range, a stark contrast to the dispersion shown in Figure 7 before surface modification. This indicates that surface modification alters the physicochemical properties of the nano-CaCO3 surface, changing it from hydrophilic and oleophobic to oleophilic and hydrophobic, significantly improving the dispersion of nano-CaCO3 in the anhydrous ethanol system. Table 2 shows the physicochemical properties of the melamine-formaldehyde resins in Examples 2, 2, and 3. The table shows that the melamine-formaldehyde resin prepared in Example 2 has a long curing time and good storage stability. The long curing time indicates good heat resistance, enabling it to withstand corrosion and oxidation in high-temperature environments. The poor storage stability of Comparative Examples 2 and 3 may be due to the fact that KH550 is a good inorganic particle surface modifier. It modifies the surface of nano-CaCO3, giving nano-calcium carbonate a large specific surface area and high surface free energy. As a result, nano-calcium carbonate has a very strong tendency to agglomerate, forming aggregates that enter the melamine-formaldehyde resin, thus giving the resin good storage stability.

[0061] Example 3

[0062] This embodiment provides an environmentally friendly E NF The manufacturing process of the Class A fireproof board is as follows:

[0063] S1. Preparation of modified urea-formaldehyde resin: Add 240 mL of 37.0% formaldehyde solution to a 500 mL four-necked flask, and adjust the pH of the formaldehyde solution to 9 using 30% NaOH solution; then place the four-necked flask in a water bath, heat to 46℃ and maintain the temperature for 16 min; at this time, add 10 g of urea to the four-necked flask and start heating, raising the reaction system to about 96℃ and maintaining the temperature for 46 min; then adjust the pH of the reaction solution to 6 using 50% formic acid solution, and maintain the reaction temperature at 92℃ (using a dropper head during the reaction). A tube was used to draw up urea-formaldehyde resin solution (reaction solution) and add it to water, with the degree of reaction measured in real time. When the resin produced a persistent white mist in the water, the reaction temperature was lowered to approximately 80°C. The pH was then adjusted to 7 with a 30% NaOH solution, and 18 mg of urea was added. The reaction was allowed to proceed for 28 minutes. The pH was then adjusted to 9 with another 30% NaOH solution, and 12 mg of urea and 6 mg of nano-MgCO3 were added. The mixture was continuously stirred to dissolve the urea and ensure uniform dispersion of the nano-MgCO3. Finally, the urea-formaldehyde resin was cooled to room temperature before being discharged to obtain the modified urea-formaldehyde resin. In this step, nano-magnesium carbonate exhibits strong adsorption capacity, performing both physical and chemical adsorption on formaldehyde, forming covalent bonds with it, thereby reducing the free formaldehyde content in the resin. Furthermore, nano-magnesium carbonate forms van der Waals forces with the amino groups of the urea-formaldehyde resin, increasing intermolecular forces and thus increasing the resistance to relative flow within the fluid, resulting in increased viscosity.

[0064] S2. Treatment of melamine-formaldehyde resin: Pour 5g of nano-CaCO3 into a flask containing a condenser, then add 500ml of water and anhydrous ethanol in a 1:1 volume ratio, stir mechanically, adjust the pH to 10 using 30% NaOH solution, heat to 86℃, add 1g of coupling agent KH550, react for 48min, then centrifuge at 4000r / min for 7min, dry the obtained product at 80℃, and grind to obtain surface-modified nano-CaCO3; 100 ml of melamine-formaldehyde resin was placed in an Erlenmeyer flask, and 15 ml of anhydrous ethanol was added. The mixture was continuously stirred at room temperature using a digital display constant-temperature magnetic stirrer until the solution was uniform and transparent. Then, 8 mg of sodium alginate suspending agent was added. After the suspending agent was fully dissolved, magnetic stirring was stopped. 28 mg of surface-modified nano-CaCO3 was added, and the mixture was magnetically stirred for 10 minutes. Following this, ultrasonic dispersion was performed to ensure uniform dispersion of the nano-CaCO3. Finally, the melamine-formaldehyde resin was discharged to obtain the treated melamine-formaldehyde resin. In this step, KH550 is a good inorganic particle surface modifier. Surface modification of the nano-CaCO3 gives the nano-calcium carbonate a large specific surface area and high surface free energy, resulting in a strong tendency for the nano-calcium carbonate to aggregate. This aggregates then enter the melamine-formaldehyde resin, giving the resin good storage stability and good flowability.

[0065] S3. Modified Glass Fiber: Weigh 28g of glass fiber precursor and treat it in a muffle furnace at 580℃ for 2 hours to remove the surface wetting agent. Immerse it in a 1.5mg / ml chitosan aqueous solution and stir continuously during ultrasonic dispersion. Transfer it to a shaker and carry out the coating reaction under shaking for 24 hours. Finally, filter and wash the glass fiber multiple times and vacuum dry it at 102℃ to obtain chitosan-modified glass fiber. In this step, chitosan is a natural cationic polymer that is non-toxic, has good biocompatibility and biodegradability, and will not cause secondary pollution. The chitosan structure contains a large number of -NH2 and -OH groups. The main component of glass fiber is silicon dioxide, which forms hydrogen bonds or van der Waals forces with the -NH2 and -OH groups of chitosan, thereby improving the impact strength of the fireproof board. This modified glass fiber has wide application value in reinforcing fireproof boards.

[0066] S4, Preparation of environmentally friendly E NF Impregnated film paper for fire-resistant boards: First, the decorative base paper for the finish is impregnated in a 5:5 mixture of modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2. The impregnation solution in the impregnation tank is a mixture of the modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2 in a 5:5 ratio. The mixture contains 3.0% softener (dimethyl silicate), 5‰ penetrant (JFC-M), and 5.0‰ curing agent (polyacrylamide). The percentages are based on the proportions in the mixture. The viscosity at 25°C (using a 4-cup coater) is 16S. The curing time for one impregnation is controlled at approximately 15 minutes and 30 seconds. The impregnation amount is 64 g / m³. 2 After drying, the product undergoes a three-stage drying oven at 136℃ for the first drying stage. After the first drying stage, the product proceeds to the next step of applying adhesive. The adhesive used for applying the adhesive is the melamine-formaldehyde resin treated in step S2. Additives are also added to the treated melamine-formaldehyde resin. The additive ratio is as follows: the percentage content is based on the proportion of the treated melamine-formaldehyde resin: curing agent (polyacrylamide): 6.0‰, penetrant (JFC-M): 1.0‰, release agent (polyethylene glycol): 3.0‰, dust remover (polytetrafluoroethylene micro powder): 2‰, softener (dimethyl silicate): 3.0%, and plant negative oxygen ion extract: 7%. The plant negative oxygen ion extract contains the following components by weight: 64 parts small molecule silicon water, 24 parts rare crystal stone, 7 parts Rhodiola rosea, 4 parts Phellodendron amurense, 4 parts Atractylodes lancea, and 2 parts Mentha haplocalyx. This plant-derived negative ion extract can increase the release of negative ions from materials and also has the function of purifying formaldehyde; the adhesive is applied to the upper and lower surfaces by a set of smooth rollers and extrusion rollers on each side, with a total adhesive content of 55g / m². 2The difference in the amount of adhesive on the upper and lower surfaces is controlled within 5g. After scraping off the excess adhesive on the edge, the paper enters a five-section drying oven at 136℃ to complete the second drying. After cooling, the paper is rewound by the rewinding roller.

[0067] S5, Preparation of environmentally friendly E NF Fire-resistant board: The equipment layout sketch for the fire-resistant board production process is shown in Figure 1. In the figure, 1 is the unwinding device, 2 is the double steel belt press, 3 is the cooling device, 4 is the release paper winding device, 5 is the sanding device, 6 is the edge trimming device, 7 is the CPL winding device, 8 is the cutter (sheet CPL cutter), and 9 is the sheet CPL stacking device. The rewound impregnated paper prepared in step S4, the three layers of glass fiber modified in step S3, and the three layers of non-woven fabric are respectively fed onto the unwinding device of the fire-resistant board production line. The order of the impregnated paper and non-woven fabric is determined according to the finish type; generally, the textured non-woven fabric is added first during impregnation. Above the impregnated paper, other decorative nonwoven fabrics are below the impregnated paper. The unwinding device has a total of 8 unwinding shafts. The winding device is shown in Figure 2. After the rewinding impregnated paper, the three layers of glass fiber modified in step S3 and the nonwoven fabric are stacked, they are put into the fireproof board line double steel belt press to complete the bonding. The heating method is hot oil heating. The roller pressing steel belt pressure is increased by hydraulic oil through a pressurizing pump. The temperature points: SEK1, SEK2, SEK3 and SEK5 are 188℃, 188℃, 184℃ and 183℃ respectively. The pressure is 16 bar and the traction speed is controlled at 23m / min. The laminated surface material is the fireproof board. After exiting the press, the fireproof board enters the roller cooling station and the release paper winding device (see Figure 3). The release paper winding device is used to wind up the release paper for other surface types besides glossy and matte finishes, facilitating the reuse of the release paper. After cooling in the roller cooling station, the laminated fireproof board passes through a sanding device (see Figure 4) and then enters the CPL rewinding device (see Figure 5) to complete the rewinding, thus obtaining an E-type fireproof board. NFCPL fire-resistant decorative material. In this step, sanding is generally not used unless specifically required. Modified glass fibers (from step S3) are added to the middle of the prepared fire-resistant board paper base for reinforcement. The modified glass fibers make the original paper adhere better, thus giving the fire-resistant board better mechanical properties and durability. Plant negative oxygen ion extract is added to the adhesive solution, enabling the fire-resistant board to reduce formaldehyde and release negative oxygen ions. After impregnation with adhesive, the paper undergoes a three-stage oven drying process, followed by a five-stage oven drying process after coating with adhesive. This ensures that the volatile matter and pre-curing degree of the impregnated paper reach the target values: volatile matter: 7.6%, pre-curing degree: 27%. Depending on the paper pattern, these two indicators may deviate to some extent, but are generally controlled within the above range. After adhesive coating, some moisture is removed from the paper, and the adhesive is pre-cured. Following high-temperature hot pressing, some of the formaldehyde contained in the impregnated paper will volatilize, while the remaining portion will be decomposed and absorbed by plant-based negative oxygen ion additives, thereby reducing the formaldehyde release of the fireproof board. The final fireproof board meets the national standard E10 for formaldehyde release. NF class.

[0068] Comparative Example 4: Step S3 was the same as in Example 3 except that chitosan-modified glass fiber was not added.

[0069] The impact strength of the fireproof boards obtained in Examples 3 and 4 was tested, and the results are shown in Figure 4.

[0070] Figure 9 shows the effect of glass fiber on impact performance in Examples 3 and 4. The figure shows that the fireproof board with chitosan-modified glass fiber has an impact strength of 7.5 kJ / m. 2 The impact strength of unmodified chitosan-treated glass fiber fireproof board is 4.7 kJ / m. 2 This indicates that the impact strength of fireproof boards prepared with chitosan-modified glass fiber is increased. The reason may lie in the large amount of -NH2 and -OH groups in the chitosan structure. Since glass fiber's main component is silicon dioxide, it forms hydrogen bonds or van der Waals forces with the -NH2 and -OH groups of chitosan, thereby improving the impact strength of the fireproof board. This modified glass fiber has broad application value in reinforcing fireproof boards. Furthermore, chitosan is a natural cationic polymer, non-toxic, with good biocompatibility and biodegradability, and will not cause secondary pollution.

[0071] Example 4

[0072] This embodiment provides an environmentally friendly E NF The manufacturing process of the Class A fireproof board is as follows:

[0073] S1. Preparation of modified urea-formaldehyde resin: Add 250 mL of 37.5% formaldehyde solution to a 500 mL four-necked flask, and adjust the pH of the formaldehyde solution to 9 using 30% NaOH solution; then place the four-necked flask in a water bath, heat to 50℃ and maintain the temperature for 20 min; at this time, add 10 g of urea to the four-necked flask and start heating, raising the reaction system to about 100℃ and maintaining the temperature for 50 min; then adjust the pH of the reaction solution to 6 using 50% formic acid solution, and maintain the reaction temperature at 95℃ (using a dropper head during the reaction). A tube is used to draw urea-formaldehyde resin solution (reaction solution) and add it to water, with the degree of reaction measured in real time. When the resin produces a persistent white mist in the water, the reaction temperature is lowered to approximately 80°C. The pH is then adjusted to 7 with a 30% NaOH solution, and 20 mg of urea is added, reacting for 30 minutes. The pH is then adjusted to 9 with another 30% NaOH solution, and 20 mg of urea and 8 mg of nano-MgCO3 are added, stirring continuously to dissolve the urea and evenly disperse the nano-MgCO3. Finally, the urea-formaldehyde resin is cooled to room temperature before being discharged to obtain modified urea-formaldehyde resin. In this step, nano-magnesium carbonate exhibits strong adsorption capacity, performing both physical and chemical adsorption on formaldehyde, forming covalent bonds with it, thereby reducing the free formaldehyde content in the resin. Furthermore, nano-magnesium carbonate forms van der Waals forces with the amino groups of the urea-formaldehyde resin, increasing intermolecular forces and thus increasing the resistance to relative flow within the fluid, resulting in increased viscosity.

[0074] S2. Treatment of melamine-formaldehyde resin: Pour 5g of nano-CaCO3 into a flask containing a condenser, add 500ml of water and anhydrous ethanol in a 1:1 volume ratio, stir mechanically, adjust the pH to 11 using 30% NaOH solution, heat to 90℃, add 1g of coupling agent KH550, react for 50min, then centrifuge at 4000r / min for 8min, dry the product at 80℃, and grind to obtain surface-modified nano-CaCO3; 100 ml of melamine-formaldehyde resin was placed in an Erlenmeyer flask, and 15 ml of anhydrous ethanol was added. The mixture was continuously stirred at room temperature using a digital display constant-temperature magnetic stirrer until the solution was uniform and transparent. Then, 10 mg of sodium alginate suspending agent was added. After the suspending agent was fully dissolved, magnetic stirring was stopped. 30 mg of surface-modified nano-CaCO3 was added, and the mixture was magnetically stirred for 10 minutes. Following this, ultrasonic dispersion was performed to ensure uniform dispersion of the nano-CaCO3. Finally, the melamine-formaldehyde resin was discharged to obtain the treated melamine-formaldehyde resin. In this step, KH550 is a good inorganic particle surface modifier. Surface modification of the nano-CaCO3 gives the nano-calcium carbonate a large specific surface area and high surface free energy, resulting in a strong tendency for the nano-calcium carbonate to aggregate. This aggregates then enter the melamine-formaldehyde resin, giving the resin good storage stability and good flowability.

[0075] S3. Modified Glass Fiber: Weigh 31g of glass fiber precursor and treat it in a muffle furnace at 600℃ for 2 hours to remove the surface wetting agent. Immerse it in a 2mg / ml chitosan aqueous solution and stir continuously during ultrasonic dispersion. Transfer it to a shaker and carry out the coating reaction under shaking for 24 hours. Finally, filter and wash the glass fiber multiple times and vacuum dry it at 105℃ to obtain chitosan-modified glass fiber. In this step, chitosan is a natural cationic polymer that is non-toxic, has good biocompatibility and biodegradability, and will not cause secondary pollution. The chitosan structure contains a large number of -NH2 and -OH groups. The main component of glass fiber is silicon dioxide, which forms hydrogen bonds or van der Waals forces with the -NH2 and -OH groups of chitosan, thereby improving the impact strength of the fireproof board. This modified glass fiber has wide application value in reinforcing fireproof boards.

[0076] S4, Preparation of environmentally friendly E NF Impregnated film paper for fire-resistant boards: First, the decorative base paper for the finish is impregnated in a 5:5 mixture of modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2. The impregnation solution in the impregnation tank is a mixture of the modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2 in a 5:5 ratio. The mixture contains 3.0% softener (dimethyl silicate), 5‰ penetrant (JFC-M), and 5.0‰ curing agent (polyacrylamide). The percentages are based on the proportions in the mixture. The viscosity at 25°C (using a 4-cup coater) is 16S. The curing time for the first impregnation is controlled at approximately 15 minutes and 30 seconds. The impregnation amount is 65 g / m³. 2 After drying, the product undergoes a three-stage drying oven at 138℃ for the first drying stage. After the first drying stage, the product proceeds to the next step of applying adhesive. The adhesive used for applying the adhesive is the melamine-formaldehyde resin treated in step S2. Additives are also added to the treated melamine-formaldehyde resin. The additive ratio is as follows: the percentage content is based on the proportion of the treated melamine-formaldehyde resin. The additives are: curing agent (polyacrylamide): 6.0‰, penetrant (JFC-M): 1.0‰, release agent (polyethylene glycol): 3.0‰, dust remover (polytetrafluoroethylene micro powder): 2‰, softener (dimethyl silicate): 3.0%, and plant negative oxygen ion extract: 5-8%. The plant negative oxygen ion extract contains the following components by weight: 65 parts small molecule silicon water, 25 parts rare crystal stone, 8 parts Rhodiola rosea, 5 parts Phellodendron amurense, 5 parts Atractylodes lancea, and 3 parts Mentha haplocalyx. This plant-derived negative ion extract can increase the release of negative ions from materials and also has the function of purifying formaldehyde; the adhesive is applied to the upper and lower surfaces by a set of smooth rollers and extrusion rollers on each side, with a total adhesive content of 55g / m². 2The difference in glue amount between the upper and lower surfaces is controlled within 5g. After scraping off the excess glue at the edge, the paper enters a five-stage drying oven at 138℃ for the second drying. After cooling, the paper is rewound by the rewinding roller.

[0077] S5, Preparation of environmentally friendly E NF Fire-resistant board: The equipment layout sketch for the fire-resistant board production process is shown in Figure 1. In the figure, 1 is the unwinding device, 2 is the double steel belt press, 3 is the cooling device, 4 is the release paper winding device, 5 is the sanding device, 6 is the edge trimming device, 7 is the CPL winding device, 8 is the cutter (sheet CPL cutter), and 9 is the sheet CPL stacking device. The rewound impregnated paper prepared in step S4, the three layers of glass fiber modified in step S3, and the three layers of non-woven fabric are respectively fed onto the unwinding device of the fire-resistant board production line. The order of the impregnated paper and non-woven fabric is determined according to the finish type; generally, the textured non-woven fabric is added first during impregnation. Above the impregnated paper, other decorative nonwoven fabrics are below the impregnated paper. The unwinding device has a total of 8 unwinding shafts. The winding device is shown in Figure 2. After the rewinding impregnated paper, the three layers of glass fiber modified in step S3 and the nonwoven fabric are stacked, they are put into the fireproof board line double steel belt press to complete the bonding. The heating method is hot oil heating. The roller pressing steel belt pressure is increased by hydraulic oil through a pressure pump. The temperature points: SEK1, SEK2, SEK3 and SEK5 are 190℃, 190℃, 185℃ and 190℃ respectively. The pressure is 17 bar and the traction speed is controlled at 25m / min. The laminated surface material is the fireproof board. After exiting the press, the fireproof board enters the roller cooling station and the release paper winding device (see Figure 3). The release paper winding device is used to wind up the release paper for other surface types besides glossy and matte finishes, facilitating the reuse of the release paper. After cooling in the roller cooling station, the laminated fireproof board passes through a sanding device (see Figure 4) and then enters the CPL rewinding device (see Figure 5) to complete the rewinding, thus obtaining an E-type fireproof board. NFCPL fire-resistant decorative material. In this step, sanding is generally not used unless specifically required. Modified glass fibers (from step S3) are added to the middle of the prepared fire-resistant board paper base for reinforcement. The modified glass fibers make the original paper adhere better, thus giving the fire-resistant board better mechanical properties and durability. Plant negative oxygen ion extract is added to the adhesive solution, enabling the fire-resistant board to reduce formaldehyde and release negative oxygen ions. After impregnation with adhesive, the paper undergoes a three-stage oven drying process, followed by a five-stage oven drying process after coating with adhesive. This ensures that the volatile matter and pre-curing degree of the impregnated paper reach the target values: volatile matter: 8.0%, pre-curing degree: 40%. Depending on the paper pattern, these two indicators may deviate to some extent, but are generally controlled within the above range. After adhesive coating, some moisture is removed from the paper, and the adhesive is pre-cured. Following high-temperature hot pressing, some of the formaldehyde contained in the impregnated paper will volatilize, while the remaining portion will be decomposed and absorbed by plant-based negative oxygen ion additives, thereby reducing the formaldehyde release of the fireproof board. The final fireproof board meets the national standard E... NF class.

[0078] Comparative Example 5: Except for replacing the modified urea-formaldehyde resin obtained in step S1 with urea-formaldehyde resin from Wuhan Kemike Biomedical Technology Co., Ltd., which is available in the market, all other steps were the same as in Example 4.

[0079] Comparative Example 6: Except for not adding nano-Mg(CO3)2 to modify the urea-formaldehyde resin in step S1, all other steps were the same as in Example 4.

[0080] Comparative Example 7: Except for replacing the melamine-formaldehyde resin processed in step S2 with melamine-formaldehyde resin from Shandong Jiaying Chemical Technology Co., Ltd., which is available in the market, everything else was the same as in Example 4.

[0081] Comparative Example 8: In step S2, except that KH550 was not used to modify the surface of nano-CaCO3, and unmodified nano-CaCO3 (purchased from Hangzhou Hengge Nanotechnology Co., Ltd.) was directly used to treat melamine-formaldehyde resin, everything else was the same as in Example 4.

[0082] Comparative Example 9: Except for replacing the modified glass fiber in step S3 with glass fiber from Shandong Taicheng Fiber Co., Ltd. available in the market, everything else was the same as in Example 4.

[0083] Comparative Example 10: Step S4 was the same as in Example 4 except that no plant negative oxygen ion extract was added.

[0084] The test results of the fireproof boards obtained in Example 4 and Comparative Examples 5-10 are shown in Table 3.

[0085] Table 3

[0086]

[0087] Table 3 shows the E of Embodiment 4 and Comparative Examples 5-10 of the present invention. NF Table of fire resistance test results for Grade E fireproof boards. As shown in the table, the Grade E fireproof board prepared in Example 4... NF The fire-resistant board is lightweight and high-strength, with good surface wear and impact resistance. The formaldehyde emission standard requires ≤0.025 mg / L. Example 4 prepared E... NF The fire-resistant board also meets the E standard specified in GB / T39600—2021. NF The fireproof board met the required standard, but ratios of 5 to 10 did not. One reason might be that the modified urea-formaldehyde resin prepared in step S1 and the melamine-formaldehyde resin treated in step S3 were mixed in a 5:5 ratio in the impregnation tank, resulting in good wear resistance and bonding strength on the surface. Nano-magnesium carbonate modified urea-formaldehyde resin, KH550, and nano-CaCO3 modified melamine-formaldehyde resin give both resins strong adsorption capacity. Another reason might be the addition of modified glass fiber, which improves adhesion, mechanical properties, and environmental durability. This modified glass fiber has wide application value in reinforcing fireproof boards. Yet another reason is the addition of plant negative ion extract to the adhesive, which helps reduce formaldehyde and release negative ions during fireproof board preparation. In summary, these improvements reduce the formaldehyde emission of the fireproof board, ultimately achieving a formaldehyde emission level that meets the national standard E. NF class.

[0088] The embodiments described above are merely illustrative of the preparation process of the present invention and are not intended to limit the scope of the present invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An environmentally friendly E NF The manufacturing process of the Class A fireproof board is characterized by: The specific preparation steps are as follows: S1. Preparation of modified urea-formaldehyde resin: Add 200-250 mL of formaldehyde solution with a concentration of 36.5-37.5% to a 500 mL four-necked flask, and adjust the pH of the formaldehyde solution to 8-9 using 30% NaOH solution; then place the four-necked flask in a water bath, heat to 40-50℃ and keep at that temperature for 10-20 min; at this time, add 10 g of urea to the four-necked flask and start heating, raising the temperature of the reaction system to about 90-100℃ and keeping it at that temperature for 40-50 min; then adjust the pH of the reaction solution to 5-6 using 50% formic acid solution, and maintain the reaction temperature at 85-95℃; then lower the reaction temperature to 80℃. At approximately ℃; adjust the pH to 6-7 with 30% NaOH solution, add 10-20 mg of urea, and react for 20-30 minutes; then adjust the pH to 8-9 with 30% NaOH solution, add 10-20 mg of urea and 4-8 mg of nano MgCO3, and stir continuously to dissolve the urea and disperse the nano MgCO3 evenly. Finally, cool the urea-formaldehyde resin to room temperature and discharge to obtain modified urea-formaldehyde resin; S2, Treatment of melamine-formaldehyde resin: Pour 5 g of nano CaCO3 into a flask equipped with a condenser, add 500 ml of water and anhydrous ethanol in a 1:1 volume ratio, stir mechanically, and adjust the pH using 30% NaOH solution. When the pH value reaches 9-11 and the temperature is raised to 80-90℃, 1g of coupling agent KH550 is added, and the reaction is carried out for 40-50 minutes. Then, the mixture is centrifuged at 4000r / min for 5-8 minutes. The obtained product is dried at 80℃ and ground to obtain surface-modified nano-CaCO3. 100ml of melamine-formaldehyde resin is placed in an Erlenmeyer flask, and 15ml of anhydrous ethanol is added. The mixture is stirred continuously at room temperature using a digital display constant temperature magnetic stirrer until the solution is uniform and transparent. Then, 5-10mg of suspending agent sodium alginate is added. After the suspending agent is fully dissolved, the magnetic stirring is stopped. 20-30mg of surface-modified nano-CaCO3 is added, and the mixture is stirred magnetically. After 10 minutes, ultrasonic dispersion was performed to ensure uniform dispersion of nano-CaCO3. Finally, the melamine-formaldehyde resin was discharged to obtain the treated melamine-formaldehyde resin. S3, Modified glass fiber: 21-31g of glass fiber precursor was weighed and treated in a muffle furnace at 500-600℃ for 1-2 hours to remove the surface wetting agent. The precursor was then immersed in a 0.5-2mg / ml chitosan aqueous solution and stirred continuously during ultrasonic dispersion. The solution was then transferred to a shaker and subjected to a coating reaction under shaking for 24 hours. Finally, the glass fiber was filtered and washed multiple times and vacuum dried at 95-105℃ to obtain chitosan-modified glass fiber. S4, Preparation of environmentally friendly E NF Impregnated film paper for fire-resistant boards: First, the decorative base paper for the finish is impregnated in a 5:5 mixture of modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2. The adhesive solution in the impregnation tank is a mixture of the modified urea-formaldehyde resin prepared in step S1 and melamine-formaldehyde resin treated in step S2 in a 5:5 ratio, with 3.0% softener, 3-5‰ penetrant, and 5.0‰ curing agent added. The viscosity at 25℃ (using a 4-cup coater) is 15-16 seconds. The curing time is approximately 15 minutes and 30 seconds, and the impregnation amount is 60-65 g / m². 2 The material is then dried for the first time in a three-stage drying oven at 133-138℃. After the first drying, it proceeds to the next step of applying adhesive. The adhesive used is the melamine-formaldehyde resin treated in step S2, and additives have been added to the treated melamine-formaldehyde resin. The additive ratio is as follows: curing agent: 5.0-6.0‰, penetrant: 1.0‰, release agent: 3.0‰, dust remover: 2‰, softener: 3.0%, plant negative oxygen ion extract: 5-8%, and the total adhesive weight is 55g / m³. 2 The difference in glue application between the top and bottom layers is controlled within 5g. After scraping off excess glue from the edges, the paper enters a five-stage drying oven at 133-138℃ for a second drying. After cooling, it passes through a rewinding roller to complete the rewinding of the impregnated paper. S5, Preparation of environmentally friendly E NF Grade 1 Fireproof Board: The rewound impregnated paper prepared in step S4, the three layers of glass fiber modified in step S3, and the three layers of non-woven fabric are fed into the unwinding device of the fireproof board production line. The order of the impregnated paper and non-woven fabric is determined according to the surface finish type, with the glass fiber placed between the impregnated paper and the non-woven fabric. After the rewound impregnated paper, the three layers of glass fiber modified in step S3, and the non-woven fabric are stacked, they are fed into the double steel belt press of the fireproof board line for bonding. The heating method is hot oil heating, and the pressure increase method of the rolling steel belt is hydraulic oil through a pressure pump. Temperature point: SEK1. The temperatures for SEK2, SEK3, and SEK5 are 185℃-190℃, 185℃-190℃, 180℃-185℃, and 185℃-190℃, respectively, with a pressure of 15-17 bar and a traction speed controlled at 20-25 m / min. The laminated surface material is the fireproof board. After exiting the press, the fireproof board enters a roller cooling station and release paper winding. After cooling in the roller cooling station, the laminated fireproof board undergoes sanding and then enters the CPL rewinding unit for rewinding. The resulting roll yields an E-type fireproof board. NF CPL fire-resistant decorative material.

2. An environmentally friendly E as described in claim 1 NF The manufacturing process of the Class A fireproof board is characterized by: In step S1, 200 mL of a 36.5% formaldehyde solution is added to a 500 mL four-necked flask, and the pH of the formaldehyde solution is adjusted to 8 using a 30% NaOH solution.

3. An environmentally friendly E as described in claim 2 NF The manufacturing process of the Class A fireproof board is characterized by: In step S1, the four-necked flask is placed in a water bath, heated to 40°C, and kept at that temperature for 10 minutes.

4. An environmentally friendly E as described in claim 1 NF The manufacturing process of the Class A fireproof board is characterized by: In step S2, the pH value is adjusted to 9 using a 30% NaOH solution.

5. The preparation process of an environmentally friendly ENF-grade fireproof board according to claim 4, characterized in that: In step S2, 5 mg of sodium alginate suspending agent is added.

6. An environmentally friendly E as described in claim 1 NF The manufacturing process of the Class A fireproof board is characterized by: In step S3, 21g of glass fiber filament is weighed.

7. An environmentally friendly E as described in claim 6 NF The manufacturing process of the Class A fireproof board is characterized by: In step S3, a 0.5 mg / ml chitosan aqueous solution is added.

8. An environmentally friendly E as described in claim 8 NF The manufacturing process of the Class A fireproof board is characterized by: In step S4, 8% of plant negative oxygen ion extract is added; the plant negative oxygen ion extract contains the following components by weight: 60-65 parts of small molecule silicon water, 20-25 parts of rare crystal, 5-8 parts of Rhodiola rosea, 2-5 parts of Phellodendron chinense, 2-5 parts of Atractylodes lancea, and 1-3 parts of Mentha haplocalyx.

9. An environmentally friendly E as described in any one of claims 1-8 NF The fireproof board is prepared using the same manufacturing process as the grade A fireproof board.

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