An aging-resistant polyester-based FRP light-transmitting panel

Abstract

This invention discloses an aging-resistant polyester-based FRP (fiberglass reinforced polymer) light-transmitting panel, belonging to the technical field of FRP light-transmitting panels. The panel is made by uniformly dispersing modified nano-silica in phthalic unsaturated polyester resin, and then coating, pressing, and curing with alkali-free glass fiber mat in a three-stage gradient process. The modified nano-silica surface is grafted with a modifier that combines UV absorption and phosphorus-containing flame retardant functions. This modifier contains a benzimidazolinone azo structure and phosphate ester bonds. This invention eliminates the need for additional small-molecule UV absorbers or traditional flame retardants. The resulting FRP light-transmitting panel exhibits excellent aging resistance, flame retardancy, and high initial flexural strength, with no migration or precipitation of functional components, demonstrating good long-term stability.

Description

Technical Field

[0001] This invention belongs to the field of FRP (fiberglass reinforced plastic) daylighting panel technology, specifically, it relates to an aging-resistant polyester-based FRP daylighting panel. Background Technology

[0002] Existing FRP (Fiberglass Reinforced Plastic) daylighting panels mostly use unsaturated polyester resin as the matrix, and add additives such as UV absorbers and antioxidants to delay photoaging, or add halogenated and phosphorus-based flame retardants to improve flame retardancy. However, these added small-molecule additives are only physically blended with the resin matrix, resulting in poor compatibility. During long-term use, they are prone to migration and precipitation, leading to a significant decrease in aging resistance and flame retardancy over time. Meanwhile, traditional UV absorbers (such as benzotriazoles and benzophenones), although capable of absorbing some ultraviolet light, have limited photostability and will decompose and fail after long-term irradiation, making it difficult to maintain the flexural strength retention and appearance of the panel. Furthermore, while simply adding inorganic nanoparticles (such as unmodified nano-silica) has a certain reinforcing effect, the high surface energy and tendency to aggregate of nanoparticles can cause internal defects in the resin matrix, reducing initial mechanical properties. Regarding flame retardancy, conventional flame retardants often require high dosages to achieve the ideal limiting oxygen index, but high dosages can deteriorate the mechanical strength and light transmittance of the panel. In summary, there is a lack of existing technologies for FRP daylighting panels that can simultaneously achieve long-term UV resistance, high-efficiency flame retardancy, and no loss of initial mechanical properties and functional component migration. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an aging-resistant polyester-based FRP light-transmitting panel.

[0004] The objective of this invention can be achieved through the following technical solutions: An aging-resistant polyester-based FRP light-transmitting panel, wherein the manufacturing process of the FRP light-transmitting panel is as follows: Step 1: Continuously and evenly unfold the BOPET base film while keeping the film surface flat. Apply the prepared resin paste evenly to the inside of the base film, and then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 3-5 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat, and compact it evenly with multiple sets of pressure rollers, fix the thickness and remove bubbles twice to form a composite preform. Step 2: The composite blank is continuously fed into the partitioned oven, and at the same time, it is pressed into a standard tile shape using a corrugated mold. It is then cured in a three-stage gradient, cooled to room temperature, cut, and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product.

[0005] More preferably, the resin paste comprises the following components: by weight, 100-120 parts of phthalic unsaturated polyester resin, 15-18 parts of modified nano silica, 0.5-1.5 parts of defoamer, 0.5-1.5 parts of leveling agent, and 1-2 parts of curing agent.

[0006] In a more optimized manner, the preparation process of the modified silica is as follows: nano-silica is dispersed in a mixed solvent composed of anhydrous ethanol and deionized water, ultrasonically dispersed for 1 hour, a modifier is added under stirring, the pH of the system is adjusted to 5, grafting reaction is carried out at 50°C for 8 hours, and the product is filtered, washed and dried to obtain modified nano-silica.

[0007] Ideally, the ratio of the amount of nano-silica to the modifier is 10g:1.2g.

[0008] In a more optimized manner, the preparation process of the modifier is as follows: S1: Under dry nitrogen protection, 3-aminopropyltriethoxysilane and anhydrous triethylamine were added to anhydrous toluene and cooled to 0-5°C in an ice bath. The mixture was then slowly added to an anhydrous toluene solution of phosphorus oxychloride under vigorous stirring. After the addition was complete, the ice bath was removed and the reaction was continued to be stirred at room temperature for 10-12 hours. After the reaction was completed, the mixture was filtered and the filtrate was evaporated under reduced pressure to obtain intermediate A. S2: Sodium nitrite is added to deionized water to form an aqueous solution of sodium nitrite. This solution is then slowly added dropwise to a mixed solution of 5-aminobenzimidazolinone and hydrochloric acid at 0-5℃. After the addition is complete, the mixture is stirred at 0-5℃ for 5-6 minutes to obtain a diazonium salt intermediate. 3,5-Dimethylphenol is added to an aqueous solution of sodium hydroxide at 0-5℃ and stirred until homogeneous. This mixture is then slowly added to the diazonium salt intermediate. The pH is adjusted to 8, and the mixture is stirred at 0-5℃ for 1-2 hours. After the reaction is complete, the mixture is filtered, washed, dried, and recrystallized to obtain intermediate B. S3: Under a dry nitrogen atmosphere, intermediate A, intermediate B, anhydrous triethylamine, and N,N-dimethylformamide were mixed and heated to 130°C with stirring. The mixture was kept at a constant temperature for 2-3 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation of the filtrate. The filtrate was then dried under vacuum at 65°C to constant weight to obtain the modifier.

[0009] In this scheme, the terminal amino group of 3-aminopropyltriethoxysilane undergoes a nucleophilic substitution reaction with phosphorus oxychloride to remove hydrogen chloride, generating intermediate A containing an active phosphorus-chloride bond. Simultaneously, 5-aminobenzimidazolinone is diazotized at low temperature with sodium nitrite in hydrochloric acid to form a diazonium salt, which then undergoes a coupling reaction with 3,5-dimethylphenol under weakly alkaline conditions to prepare an azo intermediate B containing a phenolic hydroxyl group. Finally, under dry nitrogen protection, using N,N-dimethylformamide as a solvent, the phenolic hydroxyl group of intermediate B further undergoes nucleophilic substitution with the phosphorus-chloride bond of intermediate A, removing hydrogen chloride. By forming a stable phosphate ester bond, the silaneoxy group segment is bridged with the benzimidazolinone azo bond to obtain the target modifier.

[0010] The structure of the modifier is shown below:

[0011] In a more optimized manner, in step S1, the ratio of the amounts of 3-aminopropyltriethoxysilane, phosphorus oxychloride, and anhydrous triethylamine is 35.8g:49.7g:17.2g.

[0012] In a more optimized manner, in step S2, the ratio of the amounts of 5-aminobenzimidazolinone, hydrochloric acid, sodium nitrite, 3,5-dimethylphenol, and sodium hydroxide aqueous solution is 14.9g:20ml:6.9g:12.2g:100ml; wherein the concentration of hydrochloric acid is 12mol / L and the concentration of sodium hydroxide aqueous solution is 2mol / L.

[0013] In a more optimized manner, in step S3, the ratio of intermediate A, intermediate B and anhydrous triethylamine is 10g:16.7g:9.6g.

[0014] In a more optimized manner, the specific parameters of the three-stage gradient curing are as follows: Zone 1 temperature 90-100℃, residence time 2-3 min; Zone 2 temperature 105-110℃, residence time 2-3 min; Zone 3 temperature 115-120℃, residence time 2-3 min.

[0015] The beneficial effects of this invention are: This invention grafts a modifier with both UV absorption and phosphorus-containing flame retardant functions onto the surface of nano-silica through chemical bonding, and then uniformly disperses this modified nano-silica in phthalic unsaturated polyester resin, thereby giving the FRP light-transmitting panel excellent aging resistance and flame retardant properties.

[0016] Specifically, the modifier molecule contains benzimidazolone and azo structures. This structure has a strong ability to absorb ultraviolet light, converting high-energy ultraviolet light into low-energy heat dissipation, effectively shielding the polyester matrix from photo-oxidative corrosion by ultraviolet rays. Simultaneously, the photostability of the benzimidazolone skeleton inhibits resin yellowing and molecular chain breakage, thus significantly improving the flexural strength retention rate and reducing color difference of the board during long-term outdoor use. The modifier molecule also introduces phosphorus-containing groups through phosphate ester bonds. When heated, phosphorus catalyzes the polyester to carbonize, forming a dense, expanded carbon layer. Nano-silica, as inorganic particles, acts as physical support and thickens the insulation layer within the carbon layer, further isolating oxygen and heat transfer. The two work synergistically to enhance the flame retardant effect, significantly increasing the limiting oxygen index. Furthermore, the silanoxy segments at the end of the modifier can form strong covalent bonds with the surface of nano-silica. At the same time, the organic portion of the modifier molecule improves the interfacial compatibility between the nanoparticles and the polyester resin, preventing agglomeration and ensuring the initial flexural strength of the board.

[0017] Therefore, this invention does not require the addition of small molecule UV absorbers or traditional flame retardants. It can achieve both UV aging resistance and high-efficiency flame retardancy using only a modified nano-silica, and the functional components do not migrate or precipitate, exhibiting long-term stability. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: A process for preparing an aging-resistant polyester-based FRP light-transmitting panel is as follows: Step 1: Continuously and uniformly unfold the BOPET base film while keeping the film surface flat. Evenly apply the prepared resin paste (containing 100 parts of phthalic unsaturated polyester resin, 15 parts of modified nano silica, 0.5 parts of silicone defoamer (BYK-A530), 0.5 parts of reactive acrylate leveling agent (MF-AX), and 1 part of methyl ethyl ketone peroxide) to the inside of the base film. Then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 3 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat. Compact, fix the thickness, and remove bubbles twice by multiple sets of pressure rollers to form a composite preform. Step 2: The composite preform is continuously fed into a zoned oven and simultaneously pressed into a standard tile shape using a corrugated mold. It is then subjected to three-stage gradient curing (zone 1 temperature 90℃, 2 min; zone 2 temperature 105℃, 2 min; zone 3 temperature 115℃, 2 min), cooled to room temperature, cut, and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product. The preparation process of modified silica is as follows: 100g of nano silica is dispersed in a mixed solvent composed of anhydrous ethanol and deionized water, ultrasonically dispersed for 1h, 12g of modifier is added under stirring, the pH of the system is adjusted to 5, grafting reaction is carried out at 50℃ for 8h, and the product is filtered, washed and dried to obtain modified nano silica. The preparation process of the modifier is as follows: S1: Under dry nitrogen protection, 35.8 g of 3-aminopropyltriethoxysilane and 17.2 g of anhydrous triethylamine were added to 150 ml of anhydrous toluene. The mixture was cooled to 0 °C in an ice bath and then slowly added to an anhydrous toluene solution of phosphorus oxychloride (49.7 g of phosphorus oxychloride was added to 30 ml of anhydrous toluene). After the addition was complete, the ice bath was removed, and the mixture was stirred and reacted at room temperature for 10 h. After the reaction was completed, the mixture was filtered, and the filtrate was evaporated under reduced pressure to obtain intermediate A. S2: 6.9g of sodium nitrite was added to deionized water to form an aqueous sodium nitrite solution. This solution was then slowly added dropwise at 0°C to a mixed solution of 14.9g of 5-aminobenzimidazolinone and 20ml of hydrochloric acid (12mol / L concentration). After the addition was complete, the mixture was stirred at 0°C for 5 minutes to obtain a diazonium salt intermediate. At 0°C, 12.2g of 3,5-dimethylphenol was added to 100ml of sodium hydroxide aqueous solution (2mol / L concentration). After stirring until homogeneous, this solution was slowly added to the diazonium salt intermediate. The pH was adjusted to 8, and the mixture was stirred at 0°C for 1 hour. After the reaction was complete, the mixture was filtered, washed, dried, and recrystallized to obtain intermediate B. S3: Under a dry nitrogen atmosphere, 10g of intermediate A, 16.7g of intermediate B, 9.6g of anhydrous triethylamine, and 150ml of N,N-dimethylformamide were mixed and heated to 130℃ with stirring. The mixture was kept at a constant temperature for 2 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation of the filtrate. The filtrate was then dried under vacuum at 65℃ to constant weight to obtain the modifier.

[0020] Example 2: A process for preparing an aging-resistant polyester-based FRP light-transmitting panel is as follows: Step 1: Continuously and uniformly unfold the BOPET base film while keeping the film surface flat. Evenly apply the prepared resin paste (containing 120 parts of phthalic unsaturated polyester resin, 18 parts of modified nano silica, 1.5 parts of silicone defoamer (BYK-A530), 1.5 parts of reactive acrylate leveling agent (MF-AX), and 2 parts of methyl ethyl ketone peroxide) to the inside of the base film. Then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 5 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat. Compact, fix the thickness, and remove bubbles twice by multiple sets of pressure rollers to form a composite preform. Step 2: The composite preform is continuously fed into a zoned oven and simultaneously pressed into a standard tile shape using a corrugated mold. It is then subjected to three-stage gradient curing (zone 1 temperature 100℃, 3 min; zone 2 temperature 110℃, 3 min; zone 3 temperature 120℃, 3 min), cooled to room temperature, cut, and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product. The preparation process of modified silica is as follows: 100g of nano silica is dispersed in a mixed solvent composed of anhydrous ethanol and deionized water, ultrasonically dispersed for 1h, 12g of modifier is added under stirring, the pH of the system is adjusted to 5, grafting reaction is carried out at 50℃ for 8h, and the product is filtered, washed and dried to obtain modified nano silica. The preparation process of the modifier is as follows: S1: Under dry nitrogen protection, 35.8 g of 3-aminopropyltriethoxysilane and 17.2 g of anhydrous triethylamine were added to 150 ml of anhydrous toluene. The mixture was cooled to 0 °C in an ice bath and then slowly added to an anhydrous toluene solution of phosphorus oxychloride (49.7 g of phosphorus oxychloride was added to 30 ml of anhydrous toluene). After the addition was complete, the ice bath was removed and the mixture was stirred at room temperature for 12 h. After the reaction was completed, the mixture was filtered and the filtrate was evaporated under reduced pressure to obtain intermediate A. S2: 6.9g of sodium nitrite was added to deionized water to form an aqueous sodium nitrite solution. This solution was then slowly added dropwise at 0°C to a mixed solution of 14.9g of 5-aminobenzimidazolinone and 20ml of hydrochloric acid (12mol / L). After the addition was complete, the mixture was stirred at 0°C for 6 minutes to obtain a diazonium salt intermediate. At 0°C, 12.2g of 3,5-dimethylphenol was added to 100ml of sodium hydroxide aqueous solution (2mol / L). After stirring until homogeneous, this solution was slowly added to the diazonium salt intermediate. The pH was adjusted to 8, and the mixture was stirred at 0°C for 2 hours. After the reaction was complete, the mixture was filtered, washed, dried, and recrystallized to obtain intermediate B. S3: Under a dry nitrogen atmosphere, 10g of intermediate A, 16.7g of intermediate B, 9.6g of anhydrous triethylamine, and 150ml of N,N-dimethylformamide were mixed and heated to 130℃ with stirring. The mixture was kept at a constant temperature for 3h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation of the filtrate. The filtrate was then dried under vacuum at 65℃ to constant weight to obtain the modifier.

[0021] Example 3: A process for preparing an aging-resistant polyester-based FRP light-transmitting panel is as follows: Step 1: Continuously and uniformly unfold the BOPET base film while keeping the film surface flat. Evenly apply the prepared resin paste (containing 110 parts of phthalic unsaturated polyester resin, 16.5 parts of modified nano silica, 1.0 part of silicone defoamer (BYK-A530), 1.0 part of reactive acrylate leveling agent (MF-AX), and 1.5 parts of methyl ethyl ketone peroxide) to the inside of the base film. Then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 4 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat. Compact, fix the thickness, and remove bubbles twice by multiple sets of pressure rollers to form a composite preform. Step 2: The composite preform is continuously fed into a zoned oven and simultaneously pressed into a standard tile shape using a corrugated mold. It is then subjected to a three-stage gradient curing process (zone 1: 95℃, 2.5 min; zone 2: 107.5℃, 2.5 min; zone 3: 117.5℃, 2.5 min). After cooling to room temperature, it is cut and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product. The preparation process of modified silica is as follows: 100g of nano silica is dispersed in a mixed solvent composed of anhydrous ethanol and deionized water, ultrasonically dispersed for 1h, 12g of modifier is added under stirring, the pH of the system is adjusted to 5, grafting reaction is carried out at 50℃ for 8h, and the product is filtered, washed and dried to obtain modified nano silica. The preparation process of the modifier is as follows: S1: Under dry nitrogen protection, 35.8 g of 3-aminopropyltriethoxysilane and 17.2 g of anhydrous triethylamine were added to 150 ml of anhydrous toluene. The mixture was cooled to 0 °C in an ice bath and then slowly added to an anhydrous toluene solution of phosphorus oxychloride (49.7 g of phosphorus oxychloride was added to 30 ml of anhydrous toluene). After the addition was complete, the ice bath was removed, and the mixture was stirred at room temperature for 11 h. After the reaction was completed, the mixture was filtered, and the filtrate was evaporated under reduced pressure to obtain intermediate A. S2: 6.9g of sodium nitrite was added to deionized water to form an aqueous sodium nitrite solution. This solution was then slowly added dropwise at 0°C to a mixed solution of 14.9g of 5-aminobenzimidazolinone and 20ml of hydrochloric acid (12mol / L). After the addition was complete, the mixture was stirred at 0°C for 5.5 minutes to obtain a diazonium salt intermediate. At 0°C, 12.2g of 3,5-dimethylphenol was added to 100ml of sodium hydroxide aqueous solution (2mol / L). After stirring until homogeneous, this solution was slowly added to the diazonium salt intermediate. The pH was adjusted to 8, and the mixture was stirred at 0°C for 1.5 hours. After the reaction was complete, the mixture was filtered, washed, dried, and recrystallized to obtain intermediate B. S3: Under a dry nitrogen atmosphere, 10g of intermediate A, 16.7g of intermediate B, 9.6g of anhydrous triethylamine, and 150ml of N,N-dimethylformamide were mixed and heated to 130℃ with stirring. The mixture was kept at a constant temperature for 2.5h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation of the filtrate. The filtrate was then dried under vacuum at 65℃ to constant weight to obtain the modifier.

[0022] Comparative Example 1: No modification was made to the nano-silica, as follows: Step 1: Continuously and uniformly unfold the BOPET base film while keeping the film surface flat. Evenly apply the prepared resin paste (containing 110 parts of phthalic unsaturated polyester resin, 16.5 parts of nano silica, 1.0 part of silicone defoamer (BYK-A530), 1.0 part of reactive acrylate leveling agent (MF-AX), and 1.5 parts of methyl ethyl ketone peroxide) to the inside of the base film. Then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 4 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat. Compact, fix the thickness, and remove bubbles twice by multiple sets of pressure rollers to form a composite preform. Step 2: The composite preform is continuously fed into a zoned oven and simultaneously pressed into a standard tile shape using a corrugated mold. It is then subjected to three-stage gradient curing (zone 1 temperature 95℃, 2.5 min; zone 2 temperature 107.5℃, 2.5 min; zone 3 temperature 117.5℃, 2.5 min), cooled to room temperature, cut, and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product.

[0023] Comparative Example 2: A commercially available ultraviolet absorber (UV-326) was added to the resin paste. Step 1: Continuously and uniformly unfold the BOPET base film while keeping the film surface flat. Evenly apply the prepared resin paste (containing 110 parts of phthalic unsaturated polyester resin, 14.7 parts of nano silica, 1.8 parts of UV-326, 1.0 part of silicone defoamer (BYK-A530), 1.0 part of reactive acrylate leveling agent (MF-AX), and 1.5 parts of methyl ethyl ketone peroxide) to the inside of the base film. Then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 4 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat. Compact, fix the thickness, and remove bubbles twice by multiple sets of pressure rollers to form a composite preform. Step 2: The composite preform is continuously fed into a zoned oven and simultaneously pressed into a standard tile shape using a corrugated mold. It is then subjected to three-stage gradient curing (zone 1 temperature 95℃, 2.5 min; zone 2 temperature 107.5℃, 2.5 min; zone 3 temperature 117.5℃, 2.5 min), cooled to room temperature, cut, and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product.

[0024] Testing experiment: (1) Bending strength was tested according to GB / T 1449-2005. The sample size was 80mm×10mm×plate thickness, the span was 64mm, the loading speed was 2mm / min, and 5 samples were tested in each group. The average value was taken. (2) In accordance with GB / T 16422.3-2014 standard, UVA-340 lamp tubes were used for 1000h accelerated aging. The cycle conditions were: 4h of light exposure at 60℃ and 4h of condensation at 50℃. The bending strength retention rate was recorded after 1000h. In accordance with GB / T 7921-2008 standard, the surface color of the board was tested before and after aging, and the color difference value was calculated. (3) Measure the limiting oxygen index of the material according to GB / T 8924-2005; The obtained data is shown in the table below:

[0025] Conclusion: The comparison data of the examples and comparative examples show that the present invention significantly improves the overall performance of FRP light-transmitting panels by grafting a modifier with ultraviolet absorption and flame retardant functions onto the surface of nano-silica and uniformly dispersing it in phthalic unsaturated polyester resin.

[0026] The initial flexural strength (126-130 MPa) of Examples 1 to 3 was higher than that of the unmodified Comparative Example 1 (95 MPa) and Comparative Example 2 with added commercial UV absorber (104 MPa), indicating that the modified nano-silica improved the interfacial compatibility between inorganic particles and the resin matrix, avoiding the negative impact of agglomeration on mechanical properties. After 1000 hours of accelerated UV aging, the flexural strength retention rate of the examples was as high as 89%-91%, far superior to 52% of Comparative Example 1 and 71% of Comparative Example 2; at the same time, the color difference ΔE of the examples was only 2.5-3.2, far lower than 12.6 of Comparative Example 1 and 6.8 of Comparative Example 2, proving that the benzimidazolinone and azo structure in the modifier endowed the board with efficient and durable UV shielding ability, effectively inhibiting the photo-oxidative yellowing and molecular chain breakage of the resin. Furthermore, the limiting oxygen index of the embodiment reached 27.5%-28.6%, which is significantly higher than that of Comparative Example 1 (21.3%) and Comparative Example 2 (21.8%), demonstrating the synergistic flame retardant effect of phosphorus-containing groups and nano-silica in terms of char formation and heat insulation.

[0027] In summary, this invention does not require the addition of small molecule UV absorbers or traditional flame retardants. It can achieve excellent aging resistance and flame retardancy by using only a modified nano-silica, which improves the initial strength. Moreover, the functional components are chemically bonded, which has the advantages of non-migration and long-term stability, and is significantly superior to the existing technical solutions.

[0028] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A type of aging-resistant polyester-based FRP light-transmitting panel, characterized in that: The manufacturing process of the FRP light-transmitting panel is as follows: Step 1: Continuously and evenly unfold the BOPET base film while keeping the film surface flat. Apply the prepared resin paste evenly to the inside of the base film, and then lay the alkali-free glass fiber mat on top of it. After laying, let it stand at room temperature for 3-5 minutes. Then cover the BOPET top film on top of the alkali-free glass fiber mat, and compact it evenly with multiple sets of pressure rollers, fix the thickness and remove bubbles twice to form a composite preform. Step 2: The composite blank is continuously fed into the partitioned oven, and at the same time, it is pressed into a standard tile shape using a corrugated mold. It is then cured in a three-stage gradient, cooled to room temperature, cut, and cured at room temperature for 24 hours. The BOPET protective film on both sides of the board is then removed to obtain the finished product.

2. The aging-resistant polyester-based FRP light-transmitting panel according to claim 1, characterized in that: The resin paste comprises the following components by weight: 100-120 parts of phthalic unsaturated polyester resin, 15-18 parts of modified nano silica, 0.5-1.5 parts of defoamer, 0.5-1.5 parts of leveling agent, and 1-2 parts of curing agent.

3. The aging-resistant polyester-based FRP light-transmitting panel according to claim 2, characterized in that: The preparation process of the modified silica is as follows: nano silica is dispersed in a mixed solvent composed of anhydrous ethanol and deionized water, ultrasonically dispersed for 1 hour, a modifier is added under stirring, the pH of the system is adjusted to 5, grafting reaction is carried out at 50°C for 8 hours, and the product is filtered, washed and dried to obtain modified nano silica.

4. The aging-resistant polyester-based FRP light-transmitting panel according to claim 3, characterized in that: The ratio of nano-silica to modifier is 10g:1.2g.

5. The aging-resistant polyester-based FRP light-transmitting panel according to claim 3, characterized in that: The preparation process of the modifier is as follows: S1: Under dry nitrogen protection, 3-aminopropyltriethoxysilane and anhydrous triethylamine were added to anhydrous toluene and cooled to 0-5°C in an ice bath. Under vigorous stirring, the mixture was slowly added to an anhydrous toluene solution of phosphorus oxychloride. After the addition was completed, the ice bath was removed and the reaction was continued to be stirred at room temperature for 10-12 hours. After the reaction was completed, the mixture was filtered and the filtrate was evaporated under reduced pressure to obtain intermediate A. S2: Sodium nitrite is added to deionized water to form an aqueous solution of sodium nitrite. This solution is then slowly added dropwise to a mixed solution of 5-aminobenzimidazolinone and hydrochloric acid at 0-5℃. After the addition is complete, the mixture is stirred at 0-5℃ for 5-6 minutes to obtain a diazonium salt intermediate. 3,5-Dimethylphenol is added to an aqueous solution of sodium hydroxide at 0-5℃ and stirred until homogeneous. This mixture is then slowly added to the diazonium salt intermediate. The pH is adjusted to 8, and the mixture is stirred at 0-5℃ for 1-2 hours. After the reaction is complete, the mixture is filtered, washed, dried, and recrystallized to obtain intermediate B. S3: Under a dry nitrogen atmosphere, intermediate A, intermediate B, anhydrous triethylamine, and N,N-dimethylformamide were mixed and heated to 130°C with stirring. The mixture was kept at a constant temperature for 2-3 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation of the filtrate. The residue was dissolved in a small amount of anhydrous ethanol and then slowly added dropwise to a large amount of deionized water to precipitate. The mixture was filtered and dried under vacuum at 65°C to constant weight to obtain the modifier.

6. The aging-resistant polyester-based FRP light-transmitting panel according to claim 5, characterized in that: In step S1, the ratio of the amounts of 3-aminopropyltriethoxysilane, phosphorus oxychloride, and anhydrous triethylamine is 35.8g:49.7g:17.2g.

7. The aging-resistant polyester-based FRP light-transmitting panel according to claim 5, characterized in that: In step S2, the ratio of the amounts of 5-aminobenzimidazolinone, hydrochloric acid, sodium nitrite, 3,5-dimethylphenol, and sodium hydroxide aqueous solution is 14.9g:20ml:6.9g:12.2g:100ml; wherein the concentration of hydrochloric acid is 12mol / L and the concentration of sodium hydroxide aqueous solution is 2mol / L.

8. The aging-resistant polyester-based FRP light-transmitting panel according to claim 5, characterized in that: In step S3, the ratio of intermediate A, intermediate B and anhydrous triethylamine is 10g:16.7g:9.6g.

9. The aging-resistant polyester-based FRP light-transmitting panel according to claim 1, characterized in that: The specific parameters for the three-stage gradient curing are as follows: Zone 1 temperature 90-100℃, stay 2-3 min; Zone 2 temperature 105-110℃, stay 2-3 min; Zone 3 temperature 115-120℃, stay 2-3 min.

Images