Weather-resistant unsaturated polyester resin as well as preparation method and photovoltaic application thereof

Abstract

The invention discloses weather-resistant unsaturated polyester resin as well as a preparation method and photovoltaic application thereof, and relates to the technical field of high polymer materials. When the weather-resistant unsaturated polyester resin is prepared, 1, 6-hexanediol, itaconic acid and an ultraviolet absorption monomer are subjected to esterification and polycondensation to prepare unsaturated polyester; the preparation method comprises the following steps: carrying out reaction on naringenin and 4-isocyanate-tetramethylpiperidine oxide to prepare a functional cross-linking agent; the preparation method comprises the following steps: reacting 3-(4-chlorphenyl) phosphine, 2, 2 '-thiobis (4-chlorophenol) and 2-butene-1, 4-diamine, and polymerizing and coating silicon dioxide to prepare pre-modified silicon dioxide; reacting the pre-modified silicon dioxide, n-butylamine and nickel acetate to obtain modified silicon dioxide; uniformly mixing unsaturated polyester, a functional cross-linking agent and modified silicon dioxide, and performing injection molding to obtain the weather-resistant unsaturated polyester resin. The weather-resistant unsaturated polyester resin prepared by the invention has excellent anti-aging, flame-retardant, self-repairing and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and specifically to a weather-resistant unsaturated polyester resin, its preparation method, and its application in photovoltaics. Background Art

[0002] Photovoltaic power generation converts solar energy into electrical energy, reducing the dependence on traditional non-renewable energy sources such as coal and oil, and improving the diversification and sustainability of energy supply; Photovoltaic power generation is also a clean energy source that does not produce carbon dioxide and other harmful gases or pollutants, which is of great significance for reducing environmental pollution and addressing climate change.

[0003] Unsaturated polyester resin is a linear polymer compound formed by the polycondensation of unsaturated dibasic acids with diols or saturated dibasic acids with unsaturated diols, and its main chain contains both ester bonds and unsaturated double bonds. Unsaturated polyester resin has the advantages of light weight, corrosion resistance, and low cost, and is widely used in the photovoltaic industry, including but not limited to photovoltaic brackets, photovoltaic frames, photovoltaic aisle plates, and maintenance grid plates. Unsaturated polyester resin is prone to aging phenomena such as yellowing and powdering when placed under light for a long time, and at the same time, the unique composition of C, H, and O elements in its structure makes unsaturated polyester resin extremely flammable. These problems limit the application of unsaturated polyester resin in the photovoltaic industry. Therefore, it is necessary to improve the existing technology to enhance the anti-aging performance and flame retardancy of unsaturated polyester resin. Summary of the Invention

[0004] The purpose of the present invention is to provide a weather-resistant unsaturated polyester resin, its preparation method, and its application in photovoltaics to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: A weather-resistant unsaturated polyester resin, which is prepared by reacting an intermediate with 5-hydrazinoisophthalic acid to obtain an ultraviolet absorption monomer; esterifying and polycondensing 1,6-hexanediol, itaconic acid, and the ultraviolet absorption monomer to obtain an unsaturated polyester; reacting pre-modified silica, n-butylamine, and nickel acetate to obtain modified silica; mixing the unsaturated polyester, a functional crosslinking agent, and the modified silica uniformly and injection molding to obtain the weather-resistant unsaturated polyester resin; The intermediate is prepared by reacting salicylic acid with salicylamide; The pre-modified silica is prepared by reacting 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) with 2-butene-1,4-diamine and polymerically coating it on silica; The functional crosslinking agent is prepared by reacting naringenin with 4-isocyanate-tetramethylpiperidine oxide.

[0006] A preparation method of a weather-resistant unsaturated polyester resin, the preparation method of the weather-resistant unsaturated polyester resin comprising the following preparation steps: (1) Mix 1,6-hexanediol, itaconic acid, and an ultraviolet absorption monomer evenly at a molar ratio of 1:(0.6 - 0.7):(0.5 - 0.6), place them in a reaction kettle, and prepare a mixed monomer; add p-toluenesulfonic acid at 0.01 - 0.02 times the mass of the mixed monomer, and p-methoxyphenol at 0.02 - 0.03 times the mass of the mixed monomer. Under nitrogen protection, stir and react at 148 - 152 °C and 100 - 200 r / min for 100 - 120 min. Then add dibutyltin dilaurate at 0.01 - 0.02 times the mass of the mixed monomer, control the vacuum degree to be 0.09 - 0.11 MPa, and continue to stir and react at 148 - 152 °C and 100 - 200 r / min for 4 - 5 h. Cool to room temperature to obtain an unsaturated polyester; (2) Add naringenin and 4-isocyanate-tetramethylpiperidine oxide at a molar ratio of 1:3 to N,N-dimethylformamide at 8 - 10 times the mass of naringenin, stir and react at 70 - 80 °C and 200 - 300 r / min for 4 - 5 h, and dry at 50 - 60 °C for 8 - 10 h under vacuum conditions to obtain a functional crosslinking agent; (3) Mix pre-modified silica and chloroform evenly at a mass ratio of 1:(39 - 41), ultrasonically disperse for 20 - 30 min, add n-butylamine at 3 - 4 times the mass of the pre-modified silica, and nickel acetate at 1.8 - 2.2 times the mass of the pre-modified silica. Stir and react at 59 - 61 °C and 200 - 300 r / min for 2 - 3 h, cool to room temperature, filter, wash with anhydrous ethanol and deionized water 3 - 5 times each, and dry at 50 - 60 °C for 10 - 12 h under vacuum conditions to obtain modified silica; (4) Mix the unsaturated polyester, the functional crosslinking agent, and the modified silica at a mass ratio of 1:(0.07 - 0.08):(0.04 - 0.05), place them in a screw extruder for injection molding, demold after cooling to room temperature to obtain a weather-resistant unsaturated polyester resin.

[0007] As an optimization, the preparation method of the ultraviolet absorption monomer in step (1) is as follows: Under nitrogen protection, 5-hydrazinoisophthalic acid and triethylamine are added to absolute ethanol with a mass 18 - 20 times that of 5-hydrazinoisophthalic acid at a molar ratio of 1:1. The mixture is stirred at 40 - 50 °C and 200 - 300 r / min for 8 - 10 min. Then, an intermediate with a molar amount 1.2 - 1.4 times that of 5-hydrazinoisophthalic acid is added, and acetic acid with a mass 0.5 - 0.7 times that of 5-hydrazinoisophthalic acid is added. The temperature is raised to 60 - 62 °C, and stirring continues for 70 - 80 min. After cooling to room temperature, the pH is adjusted to 5.8 - 6.2 with 1 mol / L sodium hydroxide aqueous solution, followed by filtration. The product is dried at 40 - 50 °C for 10 - 12 h to obtain the ultraviolet absorption monomer. The reaction process is as follows: 。

[0008] As an optimization, the CAS number of 5-hydrazinoisophthalic acid is 121385-69-1; its structural formula is: 。

[0009] As an optimization, the preparation method of the intermediate is as follows: Salicylic acid and salicylamide are added to o-xylene with a mass 6 - 8 times that of salicylic acid at a molar ratio of 1:1. Pyridine with a mass 0.1 - 0.2 times that of salicylic acid is added. The mixture is stirred at 20 - 30 °C and 200 - 300 r / min for 10 - 12 min. Then, the temperature is raised to 69 - 71 °C, and thionyl chloride with a molar amount 2 times that of salicylic acid is added dropwise at a uniform rate within 90 min. After the addition is complete, the temperature is raised to 119 - 121 °C, and stirring continues for 60 - 70 min. After cooling to room temperature, petroleum ether with the same volume as o-xylene is added and mixed evenly. The mixture is allowed to stand for 1 - 2 h, followed by filtration. Under vacuum conditions, the product is dried at 40 - 50 °C for 8 - 10 h to obtain the intermediate. The reaction process is as follows: 。

[0010] As an optimization, the CAS number of 4-isocyanate-tetramethylpiperidine oxide in step (2) is 88418-69-3; its structural formula is: 。

[0011] As an optimization, the preparation method of the pre-modified silica in step (3) is as follows: Mix silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene evenly, and perform ultrasonic dispersion for 1 to 2 h. Add triethylamine in an amount 0.5 to 0.6 times the mass of silica. Under the stirring conditions of 70 to 80 °C and 200 to 300 r / min, dropwise add a diamine solution in an amount 28 to 30 times the mass of silica evenly within 25 min. After the dropping is completed, continue stirring and reacting for 90 to 100 min, filter, wash 3 to 5 times each with absolute ethanol and deionized water, and dry at 50 to 60 °C under vacuum conditions for 10 to 12 h to obtain pre-modified silica.

[0012] As an optimization, the preparation method of the diamine solution is as follows: Mix 2-butene-1,4-diamine and toluene evenly according to a mass ratio of 1:(3 to 4) to prepare a diamine solution.

[0013] As an optimization, the mass ratio of silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene is 1:(3 to 4):(2 to 3):(60 to 70).

[0014] As an optimization, the particle size of the silica is 1250 mesh, and it is purchased from Tianbao Haotong Stone Processing Factory in Hongqiao District, Tianjin.

[0015] As an optimization, the process parameters of the injection molding in step (4) are as follows: Set the barrel temperature of the extruder to 180 to 190 °C, the screw speed to 100 to 120 r / min, the injection temperature to 182 to 184 °C, the injection pressure to 40 to 50 MPa, the holding pressure time to 20 to 22 s, and the mold temperature to 70 to 80 °C.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: When preparing the weather-resistant unsaturated polyester resin of the present invention, salicylic acid and salicylamide are reacted to obtain an intermediate; the intermediate and 5-hydrazinoisophthalic acid are reacted to obtain an ultraviolet absorption monomer; 1,6-hexanediol, itaconic acid, and the ultraviolet absorption monomer are esterified and polycondensed to obtain an unsaturated polyester; naringenin and 4-isocyanate-tetramethylpiperidine oxide are reacted to obtain a functional crosslinking agent; 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and 2-butene-1,4-diamine are reacted, and polymerized and coated on silica to obtain pre-modified silica; the pre-modified silica, n-butylamine, and nickel acetate are reacted to obtain modified silica; the unsaturated polyester, the functional crosslinking agent, and the modified silica are mixed evenly and injection molded to obtain the weather-resistant unsaturated polyester resin.

[0017] First, react salicylic acid and salicylamide to obtain an intermediate; react the intermediate with 5-hydrazinoisophthalic acid to obtain an ultraviolet absorption monomer; the diacid on the ultraviolet absorption monomer can participate in the esterification polycondensation process of unsaturated polyester, introducing a hydroxy-phenyl-triazole structure on the side chain of the unsaturated polyester molecule. The hydroxy-phenyl-triazole structure can form a chelated hydrogen bond six-membered ring. This cyclic structure is unstable and can absorb the energy of strong ultraviolet rays, causing the molecule itself to generate intense thermal vibrations, resulting in the breakage of the intramolecular hydrogen bond. The energy is released to the outside world as harmless radiant heat energy, making the molecular structure continuously tend to be stable. Finally, it reaches a relatively stable low-energy state. The hydrogen bond is continuously formed and broken during the entire energy cycle process, converting ultraviolet light energy into low-radiation heat energy and releasing it, endowing the weather-resistant unsaturated polyester resin with excellent anti-aging performance.

[0018] Secondly, react naringenin with 4-isocyanate-tetramethylpiperidine oxide to obtain a functional crosslinker; the nitroxyl radicals on the functional crosslinker can react with the carbon-carbon double bonds on the unsaturated polyester and modified silica to form alkoxyamine chemical crosslinking bonds. The alkoxyamine crosslinking bonds break at high temperatures to form a large number of nitroxyl radicals, and re-bond at room temperature to form new alkoxyamine crosslinking bonds, endowing the weather-resistant unsaturated polyester resin with excellent mechanical properties and thermally reversible self-healing properties; naringenin is a naturally occurring flavonoid compound that can increase the char yield during polymer combustion, reduce the heat release and the release of volatile combustibles, endowing the weather-resistant unsaturated polyester resin with excellent flame retardant properties.

[0019] Finally, react 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) with 2-butene-1,4-diamine, and polymerize and coat on silica to obtain pre-modified silica, introducing phosphorus element, carbon-carbon double bond and 2,2'-thiobisphenol structure on the surface of the pre-modified silica; the introduction of phosphorus element can further improve the flame retardant properties of the weather-resistant unsaturated polyester resin; the carbon-carbon double bond can react with the nitroxyl radicals on the functional crosslinker to form alkoxyamine chemical crosslinking bonds. The alkoxyamine crosslinking bonds break at high temperatures to form a large number of nitroxyl radicals, and re-bond at room temperature to form new alkoxyamine crosslinking bonds, endowing the weather-resistant unsaturated polyester resin with excellent mechanical properties and thermally reversible self-healing properties; react the pre-modified silica, n-butylamine and nickel acetate to obtain modified silica; the 2,2'-thiobisphenol structure on the pre-modified silica reacts with n-butylamine and nickel acetate to generate an organic nickel complex. The organic nickel complex can effectively transfer the excited state energy of the photosensitive chromophore in the polymer and dissipate it in a harmless form, thereby preventing the polymer from undergoing photodegradation reactions and further improving the anti-aging performance of the weather-resistant unsaturated polyester resin. Detailed implementation mode

[0020] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] In the following examples and comparative examples, the silica used had a particle size of 1250 mesh and was purchased from Tianbao Haotong Stone Processing Factory in Hongqiao District, Tianjin.

[0022] Example 1:

[0023] A preparation method of a weather-resistant unsaturated polyester resin, the preparation method of the weather-resistant unsaturated polyester resin comprising the following preparation steps: (1) Add salicylic acid and salicylamide in a molar ratio of 1:1 to o-xylene with a mass 6 times that of salicylic acid, add pyridine with a mass 0.1 times that of salicylic acid, stir at 20°C and 200 r / min for 12 min, heat up to 69°C, and uniformly drip thionyl chloride with a molar amount 2 times that of salicylic acid within 90 min. After the dripping is completed, heat up to 119°C and continue stirring and reacting for 70 min. Cool to room temperature, add petroleum ether with the same volume as o-xylene and mix evenly, let stand for 1 h, filter, and dry at 40°C for 10 h under vacuum conditions to obtain an intermediate; under nitrogen protection, add 5-hydrazinoisophthalic acid and triethylamine in a molar ratio of 1:1 to absolute ethanol with a mass 18 times that of 5-hydrazinoisophthalic acid, stir at 40°C and 200 r / min for 10 min, add an intermediate with a molar amount 1.2 times that of 5-hydrazinoisophthalic acid, add acetic acid with a mass 0.5 times that of 5-hydrazinoisophthalic acid, heat up to 60°C, and continue stirring for 80 min. Cool to room temperature, adjust the pH to 5.8 with a 1 mol / L sodium hydroxide aqueous solution, filter, and dry at 40°C for 12 h to obtain an ultraviolet absorption monomer; mix 1,6-hexanediol, itaconic acid, and the ultraviolet absorption monomer evenly in a molar ratio of 1:0.6:0.5, place them in a reaction kettle, and prepare a mixed monomer; add p-toluenesulfonic acid with a mass 0.01 times that of the mixed monomer and p-methoxyphenol with a mass 0.02 times that of the mixed monomer. Under nitrogen protection, stir and react at 148°C and 100 r / min for 120 min, add dibutyltin dilaurate with a mass 0.01 times that of the mixed monomer, control the vacuum degree to 0.09 MPa, and continue stirring and reacting at 148°C and 100 r / min for 5 h. Cool to room temperature to obtain an unsaturated polyester; (2) Add naringenin and 4-isocyanate-tetramethylpiperidine oxide in a molar ratio of 1:3 to N,N-dimethylformamide with a mass 8 times that of naringenin, stir and react at 70°C and 200 r / min for 5 h, and dry at 50°C for 10 h under vacuum conditions to obtain a functional crosslinking agent; (3) Mix 2-butene-1,4-diamine and toluene evenly according to a mass ratio of 1:3 to prepare a diamine solution; mix silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene evenly according to a mass ratio of 1:3:2:60, ultrasonically disperse for 1 h, add triethylamine with a mass 0.5 times that of silica, and under the stirring conditions of 70 °C and 200 r / min, dropwise add the diamine solution with a mass 28 times that of silica evenly within 25 min. After the dropping is completed, continue stirring and reacting for 100 min, filter, wash 3 times each with absolute ethanol and deionized water, and dry under vacuum conditions at 50 °C for 12 h to obtain pre-modified silica; mix the pre-modified silica and chloroform evenly according to a mass ratio of 1:39, ultrasonically disperse for 20 min, add n-butylamine with a mass 3 times that of the pre-modified silica and nickel acetate with a mass 1.8 times that of the pre-modified silica, and react under stirring at 59 °C and 200 r / min for 3 h. Cool to room temperature, filter, wash 3 times each with absolute ethanol and deionized water, and dry under vacuum conditions at 50 °C for 12 h to obtain modified silica; (4) Mix unsaturated polyester, functional crosslinker, and modified silica according to a mass ratio of 1:0.07:0.04, place them in a screw extruder for injection molding, set the barrel temperature of the extruder to 180 °C, the screw speed to 100 r / min, the injection temperature to 182 °C, the injection pressure to 40 MPa, the holding pressure time to 22 s, the mold temperature to 70 °C, demold after cooling to room temperature, and obtain weather-resistant unsaturated polyester resin.

[0024] Example 2:

[0025] A preparation method of weather-resistant unsaturated polyester resin, the preparation method of the weather-resistant unsaturated polyester resin includes the following preparation steps: (1) Salicylic acid and salicylamide were added to o - xylene in a mass ratio of 7 times that of salicylic acid at a molar ratio of 1:1. Pyridine with a mass of 0.15 times that of salicylic acid was added. Stirring was carried out at 25 °C and 250 r / min for 11 min. Then the temperature was raised to 70 °C, and thionyl chloride with a molar amount 2 times that of salicylic acid was added dropwise evenly within 90 min. After the dropwise addition was completed, the temperature was raised to 120 °C, and stirring reaction was continued for 65 min. After cooling to room temperature, petroleum ether with the same volume as o - xylene was added and mixed evenly. Standing was carried out for 1.5 h, followed by filtration. Under vacuum conditions, drying was carried out at 45 °C for 9 h to obtain an intermediate. Under nitrogen protection, 5 - hydrazinoisophthalic acid and triethylamine were added to absolute ethanol in a mass ratio of 19 times that of 5 - hydrazinoisophthalic acid at a molar ratio of 1:1. Stirring was carried out at 45 °C and 250 r / min for 9 min. The intermediate with a molar amount 1.3 times that of 5 - hydrazinoisophthalic acid was added, and acetic acid with a mass of 0.6 times that of 5 - hydrazinoisophthalic acid was added. The temperature was raised to 61 °C, and stirring was continued for 75 min. After cooling to room temperature, the pH was adjusted to 6 with 1 mol / L sodium hydroxide aqueous solution, followed by filtration. Drying was carried out at 45 °C for 11 h to obtain an ultraviolet absorption monomer. 1,6 - Hexanediol, itaconic acid, and the ultraviolet absorption monomer were mixed evenly at a molar ratio of 1:0.65:0.55 and placed in a reaction kettle to prepare a mixed monomer. p - Toluenesulfonic acid with a mass of 0.015 times that of the mixed monomer and p - hydroxyanisole with a mass of 0.025 times that of the mixed monomer were added. Under nitrogen protection, stirring reaction was carried out at 150 °C and 150 r / min for 110 min. Dibutyltin dilaurate with a mass of 0.015 times that of the mixed monomer was added, and the vacuum degree was controlled at 0.1 MPa. Stirring reaction was continued at 150 °C and 150 r / min for 4.5 h. After cooling to room temperature, an unsaturated polyester was obtained. (2) Naringenin and 4 - isocyanate - tetramethylpiperidine oxide were added to N,N - dimethylformamide in a mass ratio of 9 times that of naringenin at a molar ratio of 1:3. Stirring reaction was carried out at 75 °C and 250 r / min for 4.5 h. Under vacuum conditions, drying was carried out at 55 °C for 9 h to obtain a functional cross - linker. (3) Mix 2-butene-1,4-diamine and toluene evenly at a mass ratio of 1:3.5 to prepare a diamine solution; mix silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene evenly at a mass ratio of 1:3.5:2.5:65, ultrasonically disperse for 1.5 h, add triethylamine 0.55 times the mass of silica, and under the stirring conditions of 75 °C and 250 r / min, uniformly dropwise add the diamine solution 29 times the mass of silica within 25 min. After the dropping is completed, continue stirring and reacting for 95 min, filter, wash 4 times each with absolute ethanol and deionized water, and dry under vacuum conditions at 55 °C for 11 h to obtain pre-modified silica; mix the pre-modified silica and chloroform evenly at a mass ratio of 1:40, ultrasonically disperse for 25 min, add n-butylamine 3.5 times the mass of the pre-modified silica and nickel acetate 2 times the mass of the pre-modified silica, and react under stirring at 60 °C and 250 r / min for 2.5 h. Cool to room temperature, filter, wash 4 times each with absolute ethanol and deionized water, and dry under vacuum conditions at 55 °C for 11 h to obtain modified silica; (4) Mix unsaturated polyester, functional cross-linking agent, and modified silica at a mass ratio of 1:0.075:0.045, place them in a screw extruder for injection molding, set the barrel temperature of the extruder to 185 °C, the screw speed to 110 r / min, the injection temperature to 183 °C, the injection pressure to 45 MPa, the holding pressure time to 21 s, the mold temperature to 75 °C, demold after cooling to room temperature, and obtain a weather-resistant unsaturated polyester resin.

[0026] Example 3:

[0027] A preparation method of a weather-resistant unsaturated polyester resin, the preparation method of the weather-resistant unsaturated polyester resin comprising the following preparation steps: (1) Salicylic acid and salicylamide were added to o-xylene at 8 times the mass of salicylic acid in a molar ratio of 1:1. Pyridine at 0.2 times the mass of salicylic acid was added. Stirring was carried out at 30 °C and 300 r / min for 10 min. The temperature was raised to 71 °C, and thionyl chloride at 2 times the molar amount of salicylic acid was added dropwise uniformly within 90 min. After the addition was complete, the temperature was raised to 121 °C, and stirring was continued for 60 min. It was cooled to room temperature, and petroleum ether with the same volume as o-xylene was added and mixed evenly. It was left standing for 2 h, filtered, and dried at 50 °C for 8 h under vacuum conditions to obtain an intermediate. Under nitrogen protection, 5-hydrazinoisophthalic acid and triethylamine were added to absolute ethanol at 20 times the mass of 5-hydrazinoisophthalic acid in a molar ratio of 1:1. Stirring was carried out at 50 °C and 300 r / min for 8 min. The intermediate at 1.4 times the molar amount of 5-hydrazinoisophthalic acid was added, and acetic acid at 0.7 times the mass of 5-hydrazinoisophthalic acid was added. The temperature was raised to 62 °C, and stirring was continued for 70 min. It was cooled to room temperature, and the pH was adjusted to 6.2 with 1 mol / L sodium hydroxide aqueous solution. It was filtered and dried at 50 °C for 10 h to obtain an ultraviolet absorption monomer. 1,6-Hexanediol, itaconic acid, and the ultraviolet absorption monomer were mixed evenly in a molar ratio of 1:0.7:0.6, placed in a reaction kettle, and formulated into a mixed monomer. p-Toluenesulfonic acid at 0.02 times the mass of the mixed monomer and p-methoxyphenol at 0.03 times the mass of the mixed monomer were added. Under nitrogen protection, stirring reaction was carried out at 152 °C and 200 r / min for 100 min. Dibutyltin dilaurate at 0.02 times the mass of the mixed monomer was added, and the vacuum degree was controlled at 0.11 MPa. Stirring reaction was continued at 152 °C and 200 r / min for 4 h, and it was cooled to room temperature to obtain an unsaturated polyester; (2) Naringenin and 4-isocyanate-tetramethylpiperidine oxide were added to N,N-dimethylformamide at 10 times the mass of naringenin in a molar ratio of 1:3. Stirring reaction was carried out at 80 °C and 300 r / min for 4 h, and it was dried at 60 °C for 8 h under vacuum conditions to obtain a functional crosslinking agent; (3) Mix 2-butene-1,4-diamine and toluene evenly according to a mass ratio of 1:4 to prepare a diamine solution; mix silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene evenly according to a mass ratio of 1:4:3:70, ultrasonically disperse for 2 h, add triethylamine 0.6 times the mass of silica, and under the stirring conditions of 80 °C and 300 r / min, uniformly dropwise add the diamine solution 30 times the mass of silica within 25 min. After the dropping is completed, continue stirring and reacting for 90 min, filter, wash 5 times each with absolute ethanol and deionized water, and dry under vacuum conditions at 60 °C for 10 h to obtain pre-modified silica; mix the pre-modified silica and chloroform evenly according to a mass ratio of 1:41, ultrasonically disperse for 30 min, add n-butylamine 4 times the mass of the pre-modified silica and nickel acetate 2.2 times the mass of the pre-modified silica, and react under stirring at 61 °C and 300 r / min for 2 h. Cool to room temperature, filter, wash 5 times each with absolute ethanol and deionized water, and dry under vacuum conditions at 60 °C for 10 h to obtain modified silica; (4) Mix unsaturated polyester, functional crosslinking agent, and modified silica according to a mass ratio of 1:0.08:0.05, place them in a screw extruder for injection molding, set the barrel temperature of the extruder to 190 °C, the screw speed to 120 r / min, the injection temperature to 184 °C, the injection pressure to 50 MPa, the holding pressure time to 20 s, the mold temperature to 80 °C, demold after cooling to room temperature, and obtain a weather-resistant unsaturated polyester resin.

[0028] Comparative Example 1: The difference between the preparation method of the weather-resistant unsaturated polyester resin in Comparative Example 1 and that in Example 2 lies in step (1). Modify step (1) as follows: Mix 1,6-hexanediol, itaconic acid, and terephthalic acid evenly according to a molar ratio of 1:0.6:0.5, place them in a reaction kettle to prepare a mixed monomer; add p-toluenesulfonic acid 0.01 times the mass of the mixed monomer and p-hydroxyanisole 0.02 times the mass of the mixed monomer. Under nitrogen protection, react under stirring at 148 °C and 100 r / min for 120 min, add dibutyltin dilaurate 0.01 times the mass of the mixed monomer, control the vacuum degree to 0.09 MPa, and continue to react under stirring at 148 °C and 100 r / min for 5 h. Cool to room temperature to obtain unsaturated polyester. The remaining steps are the same as in Example 2.

[0029] Comparative Example 2: The preparation method of the weather-resistant unsaturated polyester resin of Comparative Example 2 is different from that of Example 2 in that step (2) is not carried out, and step (4) is modified as follows: The unsaturated polyester and modified silica are mixed at a mass ratio of 1:0.045, placed in a screw extruder for injection molding, the barrel temperature of the extruder is set at 185 °C, the screw speed is 110 r / min, the injection temperature is 183 °C, the injection pressure is 45 MPa, the holding pressure time is 21 s, the mold temperature is 75 °C, and after cooling to room temperature, demolding is carried out to obtain the weather-resistant unsaturated polyester resin. The remaining steps are the same as those in Example 2.

[0030] Comparative Example 3: The preparation method of the weather-resistant unsaturated polyester resin of Comparative Example 3 is different from that of Example 2 only in step (3). Step (3) is modified as follows: 1,4-Butanediamine and toluene are mixed evenly at a mass ratio of 1:3.5 to prepare a diamine solution; silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene are mixed evenly at a mass ratio of 1:3.5:2.5:65, ultrasonically dispersed for 1.5 h, 0.55 times the mass of silica of triethylamine is added, and under the stirring condition of 75 °C and 250 r / min, the diamine solution 29 times the mass of silica is uniformly added dropwise within 25 min. After the addition is completed, stirring reaction is continued for 95 min, filtration is carried out, and each is washed 4 times with absolute ethanol and deionized water, and dried under vacuum conditions at 55 °C for 11 h to obtain pre-modified silica; the pre-modified silica and chloroform are mixed evenly at a mass ratio of 1:40, ultrasonically dispersed for 25 min, 3.5 times the mass of the pre-modified silica of n-butylamine and 2 times the mass of the pre-modified silica of nickel acetate are added, and stirring reaction is carried out at 60 °C and 250 r / min for 2.5 h, cooled to room temperature, filtered, and each is washed 4 times with absolute ethanol and deionized water, and dried under vacuum conditions at 55 °C for 11 h to obtain modified silica. The remaining steps are the same as those in Example 2.

[0031] Comparative Example 4: The preparation method of the weather-resistant unsaturated polyester resin of Comparative Example 4 is different from that of Example 2 only in step (3). Step (3) is modified as follows: 2-Butene-1,4-diamine and toluene are mixed evenly at a mass ratio of 1:3.5 to prepare a diamine solution; silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol), and toluene are mixed evenly at a mass ratio of 1:3.5:2.5:65, ultrasonically dispersed for 1.5 h, 0.55 times the mass of silica of triethylamine is added, and under the stirring condition of 75 °C and 250 r / min, the diamine solution 29 times the mass of silica is uniformly added dropwise within 25 min. After the addition is completed, stirring reaction is continued for 95 min, filtration is carried out, and each is washed 4 times with absolute ethanol and deionized water, and dried to obtain modified silica under vacuum conditions at 55 °C. The remaining steps are the same as those in Example 2.

[0032] Comparative Example 5: The difference between the preparation method of the weather-resistant unsaturated polyester resin of Comparative Example 5 and that of Example 2 is that step (3) is not carried out, and step (4) is modified as follows: The unsaturated polyester, the functional cross-linking agent, and silica are mixed at a mass ratio of 1:0.075:0.045, placed in a screw extruder for injection molding, the temperature of the extruder barrel is set at 185°C, the screw speed is 110 r / min, the injection temperature is 183°C, the injection pressure is 45 MPa, the holding pressure time is 21 s, the mold temperature is 75°C, and after cooling to room temperature, demolding is carried out to obtain the weather-resistant unsaturated polyester resin. The remaining steps are the same as those in Example 2.

[0033] Test Example 1 Test of Flame Retardant Performance Test method: According to GB / T2406.2, the examples and comparative examples are prepared into standard specimens, and the limiting oxygen index of the standard specimens is tested. The results are shown in Table 1.

[0034] Table 1 Limiting oxygen index (%) Limiting oxygen index (%) Example 1 30.85 Comparative Example 1 30.67 Example 2 31.12 Comparative Example 2 25.53 Example 3 31.04 Comparative Example 3 30.44 Comparative Example 4 30.31 Comparative Example 5 27.33 From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 1, it can be found that the weather-resistant unsaturated polyester resin prepared by the present invention has good flame retardant performance.

[0035] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 2, indicating that naringenin is a naturally occurring flavonoid compound, which can increase the char formation rate during polymer combustion, reduce the heat release amount and the release amount of volatile combustibles, and endow the weather-resistant unsaturated polyester resin with excellent flame retardant performance.

[0036] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 5, indicating that reacting 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) with 2-butene-1,4-diamine, polymerizing and coating on silica to obtain pre-modified silica, and introducing phosphorus element on the surface of the pre-modified silica can further improve the flame retardant performance of the weather-resistant unsaturated polyester resin.

[0037] Test Example 2 Test of Anti-aging Performance and Mechanics Test method: According to GB / T1040, the examples and comparative examples are prepared into standard specimens, the tensile strength M is tested, the standard specimens are irradiated with xenon arc lamp for 10 days, the tensile strength N is tested, and the change rate of the tensile strength of the examples and comparative examples before and after ultraviolet aging treatment is calculated. The change rate of the tensile strength = (M - N) / M × 100%. The results are shown in Table 2.

[0038] Table 2 Tensile strength (MPa) Tensile strength change rate (%) Tensile strength (MPa) Tensile strength change rate (%) Example 1 65.78 1.51 Comparative Example 1 65.24 4.89 Example 2 66.19 1.49 Comparative Example 2 52.25 1.64 Example 3 65.64 1.54 Comparative Example 3 58.51 1.67 Comparative Example 4 65.41 4.11 Comparative Example 5 57.33 4.07 From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 2, it can be found that the weather-resistant unsaturated polyester resin prepared in the present invention has good mechanical properties and anti-aging properties.

[0039] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Example 2, indicating that the functional crosslinking agent is prepared by reacting naringenin and 4-isocyanate-tetramethylpiperidinoxide; the nitroxide free radicals on the functional crosslinking agent can react with the carbon-carbon double bonds on the unsaturated polyester and modified silica to form alkoxyamine chemical crosslinking bonds, forming a crosslinking network, inhibiting the relative movement between molecular chains, and improving the mechanical properties of the weather-resistant unsaturated polyester resin.

[0040] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Examples 3 and 5, indicating that 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and 2-butene-1,4-diamine are reacted and polymerized and coated on silica to prepare pre-modified silica, and carbon-carbon double bonds are introduced on the surface of the pre-modified silica; the carbon-carbon double bonds can react with the nitroxide free radicals on the functional cross-linking agent to form alkoxyamine chemical cross-linking bonds, forming a cross-linking network, inhibiting the relative movement between molecular chains, and improving the mechanical properties of the weather-resistant unsaturated polyester resin.

[0041] By comparison, the change rate of tensile strength of Examples 1 to 3 is less than that of Comparative Example 1, indicating that the intermediate is obtained by reacting salicylic acid and salicylamide; the ultraviolet absorbing monomer is obtained by reacting the intermediate and 5-hydrazinoisophthalic acid; the diacid on the ultraviolet absorbing monomer can participate in the esterification and polycondensation process of the unsaturated polyester, and a hydroxyl-phenyl-triazole structure is introduced on the side chain of the unsaturated polyester molecule. The hydroxyl-phenyl-triazole structure can form a chelated hydrogen bond six-membered ring. This ring structure is unstable and can absorb the energy of strong ultraviolet rays to cause the molecule itself to produce violent thermal vibration, resulting in the breaking of hydrogen bonds in the molecule. The energy is released to the outside world through the heat energy of harmless radiation, so that the molecular structure is constantly tending to be stable, and finally reaching a relatively stable low-energy state. Hydrogen bonds are continuously formed and broken during the entire energy cycle process, converting ultraviolet light energy into low-radiation heat energy release, giving the weather-resistant unsaturated polyester resin excellent anti-aging properties.

[0042] By comparison, the change rate of the tensile strength of Examples 1 to 3 is less than that of Comparative Examples 4 to 5, indicating that 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and 2-butene-1,4-diamine are reacted, polymer-coated on silica to obtain pre-modified silica, and a 2,2'-thiobisphenol structure is introduced on the surface of the pre-modified silica; the pre-modified silica, n-butylamine, and nickel acetate are reacted to obtain modified silica; the 2,2'-thiobisphenol structure on the pre-modified silica reacts with n-butylamine and nickel acetate to generate an organonickel complex, and the organonickel complex can effectively transfer the excited-state energy of the photosensitive chromophore in the polymer and dissipate it in a harmless form, thereby preventing the polymer from undergoing a photodegradation reaction and further improving the anti-aging performance of the weather-resistant unsaturated polyester resin.

[0043] Test Example 3 Test of self-healing performance Test method: According to GB / T1040, the examples and comparative examples are prepared into standard specimens, and their tensile strength P is tested. A scratch with a length of 18 mm and a depth of 0.8 mm is made on the standard specimen with a knife, kept at 140 °C for 30 min, and left standing at room temperature for 5 h to obtain the repaired specimen, and its tensile strength Q is tested. Calculate the self-healing rate of the examples and comparative examples. The self-healing rate = Q / P × 100%. The results are shown in Table 3.

[0044] Table 3 Self-healing rate (%) Self-healing rate (%) Example 1 93.86 Comparative Example 1 93.18 Example 2 94.14 Comparative Example 2 74.22 Example 3 93.91 Comparative Example 3 86.41 Comparative Example 4 93.08 Comparative Example 5 85.62 From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 3, it can be found that the weather-resistant unsaturated polyester resin prepared by the present invention has good self-healing performance.

[0045] By comparison, the self-healing rate of Examples 1 to 3 is greater than that of Comparative Example 2, indicating that naringenin and 4-isocyanate-tetramethylpiperidine oxide are reacted to obtain a functional crosslinking agent; the nitroxyl radical on the functional crosslinking agent can react with the carbon-carbon double bonds on the unsaturated polyester and modified silica to form alkoxyamine chemical crosslinking bonds. The alkoxyamine crosslinking bonds break at high temperature to form a large number of nitroxyl radicals, and re-bond at room temperature to form new alkoxyamine crosslinking bonds, endowing the weather-resistant unsaturated polyester resin with excellent thermoreversible self-healing performance.

[0046] By comparison, the self-healing rates of Examples 1 to 3 are greater than those of Comparative Example 3 and Comparative Example 5, indicating that 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and 2-butene-1,4-diamine are reacted and polymer-coated on silica to prepare pre-modified silica, and carbon-carbon double bonds are introduced on the surface of the pre-modified silica; the carbon-carbon double bonds can react with the nitroxyl radicals on the functional cross-linking agent to form alkoxyamine chemical cross-linking bonds. The alkoxyamine cross-linking bonds break at high temperature to form a large number of nitroxyl radicals, and re-bond at room temperature to form new alkoxyamine cross-linking bonds, endowing the weather-resistant unsaturated polyester resin with excellent thermoreversible self-healing performance.

[0047] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A weather-resistant unsaturated polyester resin, characterized in that: The weather-resistant unsaturated polyester resin is prepared by reacting an intermediate and 5-hydrazinoisophthalic acid to obtain an ultraviolet absorbing monomer; esterifying and polycondensing 1,6-hexanediol, itaconic acid and an ultraviolet absorbing monomer to obtain an unsaturated polyester; reacting pre-modified silica, n-butylamine and nickel acetate to obtain modified silica; and uniformly mixing an unsaturated polyester, a functional cross-linking agent and modified silica, and performing injection molding to obtain the weather-resistant unsaturated polyester resin. The intermediate is prepared by reacting salicylic acid and salicylamide; The pre-modified silica is prepared by reacting 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and 2-butene-1,4-diamine, and polymerizing and coating the resulting mixture on silica. The functional cross-linking agent is prepared by reacting naringenin and 4-isocyanate-tetramethylpiperidinoxide.

2. A method for preparing a weather-resistant unsaturated polyester resin, characterized in that: The preparation method of the weather-resistant unsaturated polyester resin comprises the following preparation steps: (1) 1,6-hexanediol, itaconic acid and ultraviolet absorbing monomer are mixed evenly in a molar ratio of 1:(0.6-0.7):(0.5-0.6), and placed in a reaction kettle to prepare a mixed monomer; p-toluenesulfonic acid in an amount of 0.01-0.02 times the mass of the mixed monomer and p-hydroxyanisole in an amount of 0.02-0.03 times the mass of the mixed monomer are added, and the mixture is stirred at 148-152°C and 100-200 r / min for 100-120 min under nitrogen protection; dibutyltin dilaurate in an amount of 0.01-0.02 times the mass of the mixed monomer is added, and the vacuum degree is controlled to be 0.09-0.11 MPa, and the mixture is stirred at 148-152°C and 100-200 r / min for 4-5 h, and then cooled to room temperature to obtain an unsaturated polyester; (2) Adding naringenin and 4-isocyanate-tetramethylpiperidin oxide in a molar ratio of 1:3 to N,N-dimethylformamide (8 to 10 times the mass of naringenin), stirring at 70 to 80°C and 200 to 300 r / min for 4 to 5 hours, and drying at 50 to 60°C for 8 to 10 hours under vacuum conditions to obtain a functional cross-linking agent; (3) Pre-modified silica and chloroform were mixed in a mass ratio of 1:(39-41), ultrasonically dispersed for 20-30 min, and n-butylamine (3-4 times the mass of pre-modified silica) and nickel acetate (1.8-2.2 times the mass of pre-modified silica) were added. The mixture was stirred at 59-61 °C and 200-300 r / min for 2-3 h, cooled to room temperature, filtered, washed with anhydrous ethanol and deionized water for 3-5 times each, and dried at 50-60 °C under vacuum for 10-12 h to obtain modified silica. (4) Unsaturated polyester, functional crosslinking agent and modified silica are mixed in a mass ratio of 1:(0.07-0.08):(0.04-0.05), placed in a screw extruder for injection molding, and demolded after cooling to room temperature to obtain a weather-resistant unsaturated polyester resin.

3. The method for preparing a weather-resistant unsaturated polyester resin according to claim 2, characterized in that: The preparation method of the ultraviolet absorption monomer in step (1) is as follows: under nitrogen protection, 5-hydrazinoisophthalic acid and triethylamine are added in a molar ratio of 1:1 to anhydrous ethanol with a mass of 18 to 20 times that of 5-hydrazinoisophthalic acid, stirred at 40 to 50° C. and 200 to 300 r / min for 8 to 10 minutes, an intermediate with a molar mass of 1.2 to 1.4 times that of 5-hydrazinoisophthalic acid is added, acetic acid with a molar mass of 0.5 to 0.7 times that of 5-hydrazinoisophthalic acid is added, the temperature is raised to 60 to 62° C., stirring is continued for 70 to 80 minutes, cooled to room temperature, the pH is adjusted to 5.8 to 6.2 with a 1 mol / L sodium hydroxide aqueous solution, filtered, and dried at 40 to 50° C. for 10 to 12 hours to obtain an ultraviolet absorption monomer.

4. The method for preparing a weather-resistant unsaturated polyester resin according to claim 3, characterized in that: The preparation method of the intermediate comprises the following steps: adding salicylic acid and salicylamide in a molar ratio of 1:1 to o-xylene with a mass of 6 to 8 times that of salicylic acid, adding pyridine with a mass of 0.1 to 0.2 times that of salicylic acid, stirring at 200 to 300 r / min for 10 to 12 minutes at 20 to 30° C., heating to 69 to 71° C., uniformly dropping thionyl chloride with a molar mass of 2 times that of salicylic acid within 90 minutes, heating to 119 to 121° C. after the dropping is complete, continuing to stir and react for 60 to 70 minutes, cooling to room temperature, adding an equal volume of o-xylene and petroleum ether to mix evenly, standing for 1 to 2 hours, filtering, and drying at 40 to 50° C. under vacuum conditions for 8 to 10 hours to obtain the intermediate.

5. The method for preparing a weather-resistant unsaturated polyester resin according to claim 2, characterized in that: The preparation method of the pre-modified silica in step (3) is as follows: silica, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and toluene are uniformly mixed, ultrasonically dispersed for 1-2 hours, triethylamine in an amount of 0.5-0.6 times the mass of silica is added, and a diamine solution in an amount of 28-30 times the mass of silica is added dropwise at a constant rate within 25 minutes at a stirring condition of 70-80°C and 200-300 r / min. After the addition is completed, the stirring reaction is continued for 90-100 minutes, filtered, washed with anhydrous ethanol and deionized water for 3-5 times each, and dried at 50-60°C under vacuum conditions for 10-12 hours to obtain pre-modified silica.

6. The method for preparing a weather-resistant unsaturated polyester resin according to claim 5, characterized in that: The preparation method of the diamine solution is as follows: 2-butene-1,4-diamine and toluene are uniformly mixed in a mass ratio of 1:(3-4) to prepare a diamine solution.

7. The method for preparing a weather-resistant unsaturated polyester resin according to claim 5, characterized in that: The mass ratio of the silicon dioxide, 3-(4-chlorophenyl)phosphine, 2,2'-thiobis(4-chlorophenol) and toluene is 1:(3-4):(2-3):(60-70).

8. The method for preparing a weather-resistant unsaturated polyester resin according to claim 5, characterized in that: The particle size of the silicon dioxide is 1250 mesh.

9. The method for preparing a weather-resistant unsaturated polyester resin according to claim 2, characterized in that: The process parameters of the injection molding in step (4) are as follows: setting the extruder barrel temperature to 180-190°C, the screw speed to 100-120 r / min, the injection temperature to 182-184°C, the injection pressure to 40-50 MPa, the holding time to 20-22 s, and the mold temperature to 70-80°C.

10. Use of an unsaturated polyester resin prepared by the method for preparing a weather-resistant unsaturated polyester resin according to any one of claims 2 to 9 in photovoltaics.