Preparation method and application of reinforced polyurethane resin for photovoltaic frame

Abstract

The invention belongs to the field of photovoltaic materials, provides a preparation method and application of reinforced polyurethane resin for a photovoltaic frame, and solves the problem that the existing polyurethane resin for the photovoltaic frame cannot have excellent flame retardant property, water resistance, aging resistance and mechanical property at the same time. Comprising the following steps: carrying out a reaction on polytetrahydrofuran ether glycol and polyisocyanate to obtain a polyurethane prepolymer, and chemically grafting a phosphorus-containing compound onto a polyurethane main chain by using prepared 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, so as to obtain the flame-retardant polyurethane. Hydroxyl-terminated polydimethylsiloxane and polyhydric alcohol are used as part of flexible chain segments to be embedded into a polyurethane main chain, 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole is added to serve as an anti-ultraviolet agent, and final polyurethane resin is obtained through reaction. And injecting the polyurethane resin and the glass fiber into a mold, and preparing the photovoltaic frame profile through a pultrusion process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic materials, in particular to a preparation method of a reinforced polyurethane resin for photovoltaic frames and application thereof. BACKGROUND

[0002] Photovoltaic modules are the core components of solar power generation systems, mainly used for converting solar energy into direct current, storing in batteries or converting into alternating current through inverters for equipment use. Photovoltaic frames are one of the important auxiliary materials of photovoltaic modules, mainly used for protecting the edges of photovoltaic glass, strengthening the sealing performance of the modules, and improving the mechanical strength of the modules, which has an important influence on the service life of the modules, and is an indispensable part of the photovoltaic module link.

[0003] Aluminum alloy material has become the most widely used photovoltaic frame material in the market at present due to its low density, easy strengthening, high electrical conductivity, good plasticity, strong corrosion and oxidation resistance after surface treatment, long service life, easy recycling and many other advantages. With the increasing application scenarios of photovoltaic modules, the modules need to face more and more extreme environments. The traditional aluminum frame is prone to various problems such as salt mist resistance, acid and alkali resistance, corrosion, etc., and needs to be chemically treated on the surface to prevent aging, which greatly increases its cost. In addition, the poor PID (Potential Induced Degradation) performance of the aluminum frame, high production energy consumption, and great difficulty in BIPV (Building Integrated Photovoltaics) construction are all restricting its development. Composite material frames have advantages that aluminum frames do not have, which can not only bring obvious cost reduction and efficiency increase to photovoltaic module manufacturers, but also are suitable for distributed project use environments in extreme environments, and are expected to become an important force to promote the development of the photovoltaic industry.

[0004] At present, glass fiber reinforced polyurethane is the main type of composite material frame in China, which has excellent corrosion resistance, salt mist resistance and insulation performance, etc. In addition, the composite material frame can bear higher back pressure and can be adapted to coastal module design; it has multi-color selection and is suitable for BIPV construction; the production process has low carbon emissions and meets the requirements of carbon emission indicators. However, some characteristics of polyurethane resin itself hinder its long-term development in the field of photovoltaic frames. First, its flame retardancy is poor, the limiting oxygen index is relatively low, and it burns quickly, which is a great threat to the safety of photovoltaic modules. Second, polyurethane will yellow, crack, bubble, and peel under long-term ultraviolet radiation, which will reduce the strength and durability. Generally, fillers are added to the resin to improve the fire resistance and ultraviolet resistance of polyurethane, but the introduction of fillers has a certain impact on the strength of the resin. In addition, polyurethane resin prepared from polyols contains a large number of hydrophilic groups, which affects the service life of the component.

[0005] Chinese patent application number CN202310449034.8 discloses a photovoltaic panel frame resin and a preparation method thereof. The resin is prepared from 30-40 parts of acrylonitrile-styrene-chlorinated polyethylene resin, 30-40 parts of nylon resin, 10-30 parts of fluorine-containing resin, 0.1-3 parts of compatibilizer, 0.1-3 parts of thermal conductive agent, and 0.1-5 parts of other additives. In addition to having flame retardant, weather resistant, smoke resistant, high strength, light density, acid and alkali resistant, and electrically insulating properties, the prepared resin also has excellent thermal conductivity, hydrophobic and oleophobic properties, light resistance, and can still maintain high toughness under continuous high temperature conditions, effectively preventing photovoltaic panel damage caused by photovoltaic panel frame material failure. However, the use of a large number of additive stacks in the resin results in poor mechanical properties of the polyurethane resin.

[0006] Chinese patent application number CN202411389453.8 discloses a polyurethane composite material for solar photovoltaic power generation frame and support. The polyurethane composite material includes the following raw materials: compounded flame retardant, isocyanate monomer, catalyst, small molecule chain extender, functional additive, talc, dioctyl phthalate, zinc stearate, and antioxidant 168. The compounded flame retardant is prepared by introducing nitrogen-phosphorus flame-retardant elements into the structure of terminal epoxy group polybutadiene, and is subjected to polycondensation reaction with the isocyanate monomer to introduce the nitrogen-phosphorus flame-retardant elements into the polyurethane main chain, thereby imparting excellent flame-retardant properties to the polyurethane composite material. The functional additive is prepared by chemically connecting polyethylene fibers with fullerene, thereby improving the ultraviolet resistance of the polyurethane composite material and effectively prolonging its service life. However, the water resistance of the polyurethane composite material is relatively poor, which cannot effectively prevent the intrusion of water vapor and ensure the stability of the electrical properties of the photovoltaic module. Moreover, the introduction of fillers such as talc has a certain impact on the strength of the resin. SUMMARY

[0007] Therefore, to solve the problem that the existing polyurethane resin for photovoltaic frame cannot simultaneously have excellent flame-retardant properties, water resistance, aging resistance, and mechanical properties, the present application provides a preparation method of a reinforced polyurethane resin for photovoltaic frame and its application.

[0008] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0009] A preparation method of a reinforced polyurethane resin for photovoltaic frame, comprising the following steps:

[0010] S1, raw material preparation: including the following weight parts of raw materials: 3-5 parts of 9,10-dihydro-9-oxanthrene, 2-3 parts of maleic acid, 1-2 parts of polyol, 0.1-0.3 parts of antioxidant, 1-2 parts of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 0.5-1 parts of acryloyl chloride, 30-40 parts of polytetrahydrofuran ether glycol, 15-20 parts of isocyanate, 10-12 parts of hydroxyl-terminated polydimethylsiloxane, 8-10 parts of 1,4-butanediol, 0.6-1 parts of catalyst;

[0011] S2, preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide: take 9,10-dihydro-9-oxanthrene and maleic acid in step S1 by weight parts, mix with 10-12 parts by weight of xylene, heat and continuously stir under inert atmosphere, extract the lower solution with ethanol, filter after white solid precipitates, and vacuum dry to obtain DOPO-maleic acid; then dissolve the DOPO-maleic acid in 10-15 parts by weight of xylene, add polyol and antioxidant by weight parts, heat to white product disappears and evaporate water, add acid catalyst when water evaporation rate is stable, and obtain 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide after reaction;

[0012] Wherein, the DOPO in the DOPO-maleic acid is the English abbreviation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide;

[0013] The inert atmosphere includes but is not limited to nitrogen atmosphere, argon atmosphere;

[0014] The heating and continuous stirring is heated to a temperature of 120-140℃, and the stirring time is 4-6h;

[0015] The vacuum drying conditions are 80-100℃ for 24h;

[0016] The heating to white product disappearance refers to heating to white product fully dissolved, which can be observed by naked eye; or the heating temperature can be controlled at 150-160℃ until the white product disappears;

[0017] The judgment method of water evaporation rate stability is to evaluate whether the water evaporation rate reaches stability through the temperature at the top of the reaction container, specifically when the top temperature is 80-100℃, the water evaporation rate reaches stability;

[0018] The acid catalyst is concentrated sulfuric acid or toluenesulfonic acid, and the mass fraction of the acid catalyst is 98wt%;

[0019] In the step of adding acid catalyst, the acid catalyst is added until the acid value is <5mg KOH / g;

[0020] S3, Preparation of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole: Take 2-(2,4-dihydroxyphenyl)-2H-benzotriazole by weight and dissolve it in 4-6 parts by weight of triethylamine to obtain a first mixture, mix acryloyl chloride and 18-22 parts by weight of tetrahydrofuran by weight to obtain a dispersion of acryloyl chloride, add the dispersion to the first mixture, stir and react under ice bath conditions for 8-12 h to obtain a crude product, then wash the crude product with saturated sodium bicarbonate solution, evaporate the organic solvent in the system, wash with anhydrous ethanol, and dry in vacuum to obtain light yellow crystals of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0021] S4, Preparation of polyurethane resin prepolymer: Take polytetrahydrofuran ether glycol by weight, vacuum to remove water, add isocyanate and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole obtained by step S3 by weight, control the content of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole to be 0.5%-1% of the total mass of the system, maintain the reaction for 2-3 h, then cool to room temperature to obtain polyurethane resin prepolymer;

[0022] The molecular weight of the polytetrahydrofuran ether glycol is 1000-2000;

[0023] The isocyanate is a polyisocyanate; preferably, the polyisocyanate is a diisocyanate;

[0024] The diisocyanate includes but is not limited to at least one of dicyclohexylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hexahydro-toluene diisocyanate;

[0025] S5, Take hydroxyl-terminated polydimethylsiloxane by weight and mix with 60-66 parts by weight of tetrahydrofuran, stir and disperse uniformly after the hydroxyl-terminated polydimethylsiloxane is fully swollen, add the polyurethane resin prepolymer obtained by step S4, stir at room temperature for 2-4 h, then heat and react, add 1,4-butanediol, a catalyst and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide obtained by step S2 by weight, and heat and treat to obtain the reinforced polyurethane resin.

[0026] During the heating and reaction process, the temperature is 80-100°C and the time is 7-10 h.

[0027] The heat treatment refers to maintaining the reaction system at 60-80°C for 4-6 h.

[0028] Further, in step S1, the polyol is any one of ethylene glycol, propylene glycol, 1,5-pentanediol or 1,6-hexanediol.

[0029] Further, in step S1, the antioxidant is any one of diphenyl phosphite, dilauryl thiodipropionate and 2,6-di-tert-butyl-4-methylphenol.

[0030] Further, in step S1, the catalyst is at least one of, but not limited to, dibutyl tin dilaurate, stannous octoate or triethylenediamine.

[0031] An application of the reinforced polyurethane resin for photovoltaic frame, comprising the following steps: injecting the reinforced polyurethane resin prepared in step S5 into a mold fixed with glass fibers and fiber mats, adding phosphate and silane coupling agent, stirring and mixing uniformly, and making the obtained composite material pass through pultrusion molding under heating condition to obtain a fiber reinforced polyurethane resin composite material.

[0032] The heating condition is two-stage heating, the first-stage heating temperature is 80-120 DEG C, the second-stage heating temperature is 130-140 DEG C, and the pultrusion speed is 0.3-0.5 m / min; under the heating condition, the silane coupling agent reacts with the polyurethane resin and the glass fibers to enhance the strength of the product.

[0033] In order to facilitate demolding, the above preparation process further comprises the step of adding a demolding agent to the reinforced polyurethane resin when the reinforced polyurethane resin is injected; the demolding agent is one or a mixture of several kinds of zinc stearate, hydrogen phosphate, sodium alkyl benzene sulfonate in any proportion.

[0034] Further, the silane coupling agent is one or a mixture of several kinds of KH550, KH560, KH570, KH792 and DL6021 in any proportion.

[0035] Further, the adding amount of the phosphate is 0.5wt%-1.5wt% of the mass of the reinforced polyurethane resin, and the adding amount of the silane coupling agent is 1.5wt%-4wt% of the mass of the polyurethane resin.

[0036] Further, the content of the glass fibers is 50wt%-55wt% of the mass of the fiber reinforced polyurethane resin composite material, and the content of the fiber mats is 10-15wt% of the mass of the fiber reinforced polyurethane resin composite material.

[0037] The added fiber mats are glass fiber mats, and the addition of the fiber mats improves the hoop and transverse strength of the product and prevents cracking of the product.

[0038] By adopting the foregoing technical scheme, the application has the following beneficial effects:

[0039] 1. In the present invention, a phosphorus-containing compound is grafted onto a polyurethane main chain using the prepared 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. During the combustion process, the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide decomposes earlier than the main polyurethane chain, releasing phosphorus-containing fragments. The phosphorus-containing fragments interrupt the combustion reaction by capturing highly active hydrogen and hydroxyl radicals in the flame, thereby improving the flame retardant properties of the material.

[0040] 2. The present invention synthesizes a water-resistant polyurethane resin by embedding terminal hydroxyl polydimethylsiloxane and polyol as flexible chain segments into the main chain, thereby avoiding the problem of poor compatibility between the terminal hydroxyl polydimethylsiloxane and the matrix resulting from the addition of the terminal hydroxyl polydimethylsiloxane, which in turn leads to a decrease in the mechanical properties of the prepared product. In addition, the terminal hydroxyl polydimethylsiloxane forms a three-dimensional hydrophobic network to improve the water resistance of the material.

[0041] 3. The present invention introduces a benzotriazole-type reactive ultraviolet light absorber, and the dihydroxy group in the structure reacts with diisocyanate to form carbamate, thereby introducing an anti-ultraviolet group into the main chain of the polyurethane resin, thereby improving the anti-ultraviolet performance of the polyurethane resin while maintaining the excellent mechanical properties of the polyurethane resin itself. The photovoltaic frame composite material prepared using the same has good anti-aging and mechanical properties.

[0042] 4. The anti-ultraviolet agent, anti-aging agent and other additives of the present invention all play a role by reactive grafting into the chain segments of the polyurethane resin, avoiding the uneven changes in the performance of the polyurethane resin caused by simple additive superposition. While ensuring the mechanical properties of the prepared composite material, it improves the shortcomings of the polyurethane resin in photovoltaic frame applications. DETAILED DESCRIPTION

[0043] Example 1

[0044] A method for preparing a reinforced polyurethane resin for a photovoltaic frame comprises the following steps:

[0045] S1. Preparation of raw materials: including the following raw materials in parts by weight: 4 parts of 9,10-dihydro-9-xanthene, 2.5 parts of maleic acid, 1.5 parts of polyol, 0.2 parts of antioxidant, 1.5 parts of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 0.9 parts of acryloyl chloride, 35 parts of polytetramethylene ether glycol, 17 parts of isocyanate, 11 parts of hydroxy-terminated polydimethylsiloxane, 9 parts of 1,4-butanediol, and 0.8 parts of catalyst;

[0046] Wherein, the molecular weight of the polytetramethylene ether glycol is 2000;

[0047] S2, Preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide: Take 9,10-dihydro-9-oxaanthracene and maleic acid in step S1 by weight parts, mix in 12 parts by weight of xylene, heat to 140°C under N2 atmosphere and continuously stir for 4h, extract the lower solution with ethanol, filter after white solid precipitates, and vacuum dry to obtain DOPO-maleic acid; then dissolve the DOPO-maleic acid in 15 parts by weight of xylene, add polyol and antioxidant by weight parts, heat to the white product disappears and evaporate water, add acid catalyst when the water evaporation rate is stable until the acid value is 4.1 mg KOH / g, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is obtained after the reaction is completed;

[0048] wherein the polyol is ethylene glycol, the antioxidant is diphenylamine, and the acid catalyst is p-toluenesulfonic acid with a mass fraction of 98wt%;

[0049] S3, Preparation of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole: Take 2-(2,4-dihydroxyphenyl)-2H-benzotriazole dissolved in 4 parts by weight of triethylamine, stir for 5 min to obtain a first mixture, mix acryloyl chloride and 22 parts of tetrahydrofuran by weight parts to obtain a dispersion of acryloyl chloride, add the dispersion to the first mixture, stir for 8h under ice bath conditions to obtain a crude product, then wash the crude product with saturated sodium bicarbonate solution, evaporate the organic solvent in the system, wash with anhydrous ethanol, and vacuum dry to obtain light yellow crystals of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0050] S4, Preparation of polyurethane resin prepolymer: Take polytetrahydrofuran ether diol by weight parts, vacuum dehydrate at 120°C for 2h, fill nitrogen when dehydration is complete, and when the temperature drops to 80°C, add isocyanate and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole obtained by step S3 by weight parts, control the content of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole to be 0.5% of the total mass of the system, maintain the reaction for 2h, and then cool to room temperature to obtain polyurethane resin prepolymer;

[0051] The isocyanate is 4,4'-dicyclohexyl methane diisocyanate;

[0052] S5, take end hydroxyl polydimethylsiloxane and 66 parts by weight of tetrahydrofuran, mix, after the end hydroxyl polydimethylsiloxane is fully swollen, stir and disperse uniformly, add the polyurethane resin prepolymer obtained in step S4, stir at room temperature for 2h, then heat to 80℃ and react for 7h, add 1, 4-butanediol, catalyst and 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide prepared in step S2 by weight, 80℃ for 2h, to obtain the reinforced polyurethane resin;

[0053] The catalyst is dibutyl tin dilaurate.

[0054] The application of the above-mentioned reinforced polyurethane resin for photovoltaic frame includes the following steps:

[0055] (1) Hang the fiber felt on the glass fiber yarn drum on the multi-layer yarn frame, pass the glass fiber and the glass fiber felt through the frame mold at the same time, and enter the mold core, wherein the glass fiber felt is on the outside and the glass fiber is on the inside;

[0056] (2) The reinforced polyurethane resin prepared above is injected into the mold with fixed glass fiber and fiber felt by the injection machine, phosphate and silane coupling agent are added and stirred uniformly, and stirred at 3500r / min for 2.5h, then heated in stages, the first stage heating temperature is 100℃, the time is 2h, the second stage heating temperature is 130℃, the time is 3h, and finally extruded at a pulling speed of 0.4m / min to obtain a fiber reinforced polyurethane resin composite material for photovoltaic frame;

[0057] The addition amount of the phosphate is 1wt% of the mass of the reinforced polyurethane resin, the addition amount of the silane coupling agent is 2.5wt% of the mass of the polyurethane resin, and the silane coupling agent is kh560.

[0058] The content of the glass fiber is 50wt% of the mass of the fiber reinforced polyurethane resin composite material, and the content of the fiber felt is 15wt% of the mass of the fiber reinforced polyurethane resin composite material.

[0059] Example 2

[0060] A preparation method of a reinforced polyurethane resin for photovoltaic frame includes the following steps:

[0061] S1, raw material preparation: including the following weight parts of raw materials: 3 parts of 9,10-dihydro-9-oxa-xanthene, 2 parts of maleic acid, 1 part of polyol, 0.1 part of antioxidant, 1 part of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 0.5 part of acryloyl chloride, 30 parts of polytetrahydrofuran ether glycol, 15 parts of isocyanate, 10 parts of hydroxyl-terminated polydimethylsiloxane, 8 parts of 1,4-butanediol, 0.6 parts of catalyst;

[0062] The molecular weight of the polytetrahydrofuran ether glycol is 1000;

[0063] S2, preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide: take 9,10-dihydro-9-oxa-xanthene and maleic acid in step S1 by weight parts, mix with 11 parts of dimethylbenzene, heat to 140℃ under N2 atmosphere and continuously stir for 4h, extract the lower solution with ethanol, filter after white solid precipitates, and vacuum dry to obtain DOPO-maleic acid; then dissolve the DOPO-maleic acid in 15 parts of dimethylbenzene by weight, add polyol and antioxidant by weight parts, heat to the white product disappears and evaporate water, add acid catalyst when the water evaporation rate is stable until the acid value is 3mg KOH / g, and obtain 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide after the reaction is completed;

[0064] The polyol is propylene glycol, the antioxidant is diphenylamine, and the acid catalyst is concentrated sulfuric acid with a mass fraction of 98wt%;

[0065] S3, preparation of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole: take 2-(2,4-dihydroxyphenyl)-2H-benzotriazole dissolved in 4 parts of triethylamine by weight parts, stir for 5min to obtain a first mixture, mix acryloyl chloride and 22 parts of tetrahydrofuran to obtain a dispersion of acryloyl chloride, add the dispersion to the first mixture, stir for 8h under ice bath conditions to carry out the reaction to obtain a crude product, then wash the crude product with saturated sodium bicarbonate solution, evaporate the organic solvent in the system, wash with anhydrous ethanol, and vacuum dry to obtain light yellow crystals of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0066] S4, preparation of polyurethane resin prepolymer: take polytetrahydrofuran ether glycol and vacuum dry at 120℃ for 2h, then fill nitrogen when the water removal is completed, when the temperature drops to 80℃, add isocyanate and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole obtained by step S3 by weight parts, control the content of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole to be 0.5% of the total mass of the system, keep the reaction for 2h, then cool to room temperature to obtain polyurethane resin prepolymer;

[0067] The isocyanate is isophorone diisocyanate;

[0068] S5, take hydroxyl-terminated polydimethylsiloxane and 66 parts by weight of tetrahydrofuran, mix, after the hydroxyl-terminated polydimethylsiloxane is fully swollen, stir and disperse uniformly, add the polyurethane resin prepolymer obtained in step S4, stir at room temperature for 2h, then heat to 80℃ and react for 7h, add 1,4-butanediol, catalyst and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide prepared in step S2 by parts by weight, 80℃ for 2h, to obtain a reinforced polyurethane resin;

[0069] The catalyst is dibutyltin dilaurate.

[0070] The application of the above-mentioned reinforced polyurethane resin for photovoltaic frame includes the following steps:

[0071] (1) Hang the fiber felt on the glass fiber yarn drum on the multi-layer yarn stand, pass the glass fiber and the glass fiber felt through the frame mold at the same time, and enter the mold core, wherein the glass fiber felt is on the outside and the glass fiber is on the inside;

[0072] (2) The reinforced polyurethane resin prepared above is injected into the mold with fixed glass fiber and fiber felt by a glue injection machine, phosphate and silane coupling agent are added and stirred uniformly, and then stirred at 3000r / min for 3h, then heated in sections, the first section is heated at 90℃ for 3h, the second section is heated at 140℃ for 4h, and finally extruded at a pulling speed of 0.3m / min to obtain a fiber-reinforced polyurethane resin composite material for photovoltaic frame;

[0073] The addition amount of the phosphate is 0.8wt% of the mass of the reinforced polyurethane resin, the addition amount of the silane coupling agent is 2wt% of the mass of the polyurethane resin, and the silane coupling agent is kh570;

[0074] The content of the glass fiber is 55wt% of the mass of the fiber-reinforced polyurethane resin composite material, and the content of the fiber felt is 15wt% of the mass of the fiber-reinforced polyurethane resin composite material.

[0075] Example 3

[0076] A preparation method of a reinforced polyurethane resin for photovoltaic frame includes the following steps:

[0077] S1, raw material preparation: including the following weight parts of raw materials: 5 parts of 9,10-dihydro-9-oxa-xanthene, 3 parts of maleic acid, 2 parts of polyol, 0.2 parts of antioxidant, 2 parts of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 1 part of acryloyl chloride, 40 parts of polytetrahydrofuran ether glycol, 20 parts of isocyanate, 12 parts of hydroxyl-terminated polydimethylsiloxane, 10 parts of 1,4-butanediol, 1 part of catalyst;

[0078] The molecular weight of the polytetrahydrofuran ether glycol is 2000.

[0079] S2, preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide: take 9,10-dihydro-9-oxa-xanthene and maleic acid in step S1 by weight parts, mix in 10 parts of xylene, heat to 140°C under N2 atmosphere and continuously stir for 4h, extract the lower solution with ethanol, filter after white solid precipitates, and vacuum dry to obtain DOPO-maleic acid; then dissolve the DOPO-maleic acid in 15 parts of xylene by weight, add polyol and antioxidant by weight parts, heat to the white product disappears and evaporate water, add acid catalyst when the water evaporation rate is stable until the acid value is 5mg KOH / g, and obtain 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide after the reaction is completed.

[0080] The polyol is pentanediol, the antioxidant is 2,6-di-tert-butyl-4-methylphenol, and the acid catalyst is p-toluenesulfonic acid with a mass fraction of 98wt%;

[0081] S3, preparation of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole: take 2-(2,4-dihydroxyphenyl)-2H-benzotriazole dissolved in 4 parts of triethylamine by weight parts, stir for 5min to obtain a first mixture, mix acryloyl chloride and 22 parts of tetrahydrofuran by weight parts to obtain a dispersion of acryloyl chloride, add the dispersion to the first mixture, stir for 8h under ice bath conditions to carry out the reaction to obtain a crude product, then wash the crude product with saturated sodium bicarbonate solution, evaporate the organic solvent in the system, wash with anhydrous ethanol, and vacuum dry to obtain light yellow crystals of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0082] S4, preparation of polyurethane resin prepolymer: take polytetrahydrofuran ether glycol by weight parts, vacuum drying at 120℃ for 2h, after drying, fill nitrogen, when the temperature drops to 80℃, add isocyanate and the 2-(2-hydroxy-4-acryl)-2H-benzotriazole prepared by step S3 by weight parts, control the content of 2-(2-hydroxy-4-acryl)-2H-benzotriazole to be 0.5% of the total mass of the system, keep the reaction for 2h, then cool to room temperature, get polyurethane resin prepolymer;

[0083] The isocyanate is hexamethylene diisocyanate;

[0084] S5, take hydroxyl-terminated polydimethylsiloxane and 66 parts by weight of tetrahydrofuran by weight, stir and disperse uniformly after the hydroxyl-terminated polydimethylsiloxane is fully swollen, add the polyurethane resin prepolymer prepared in step S4, stir at room temperature for 2h, then heat to 80℃ for 7h, add 1,4-butanediol, catalyst and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide prepared by step S2 by weight parts, 80℃ for 2h, get reinforced polyurethane resin;

[0085] The catalyst is dibutyltin dilaurate.

[0086] The application of the above-mentioned reinforced polyurethane resin for photovoltaic frame includes the following steps:

[0087] (1) Hang the fiber felt and the glass fiber yarn cylinder on the multi-layer yarn frame, pass the glass fiber and the glass fiber felt through the frame mold at the same time, enter the mold core, wherein the glass fiber felt is at the outside and the glass fiber is at the inside;

[0088] (2) inject the reinforced polyurethane resin prepared above into the mold fixed with glass fiber and fiber felt by the injection machine, add phosphate and silane coupling agent, stir uniformly, and stir at 4000r / min for 2.5h, then heat in sections, the first section heating temperature is 110℃, the time is 3h, the second section heating temperature is 140℃, the time is 3h, finally, pull and extrude at a pulling speed of 0.5m / min to get fiber reinforced polyurethane resin composite material for photovoltaic frame;

[0089] The addition amount of the phosphate is 1.5wt% of the mass of the reinforced polyurethane resin, the addition amount of the silane coupling agent is 3wt% of the mass of the polyurethane resin, and the silane coupling agent is kh550.

[0090] The content of the glass fiber is 50wt% of the mass of the fiber reinforced polyurethane resin composite material, and the content of the fiber felt is 10wt% of the mass of the fiber reinforced polyurethane resin composite material.

[0091] Embodiment 4

[0092] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0093] S1, preparation of raw materials: including the following raw materials by weight: 3 parts of 9,10-dihydro-9-oxanthrene, 2.5 parts of maleic acid, 2 parts of polyol, 0.1 parts of antioxidant, 2 parts of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 0.7 parts of acryloyl chloride, 30 parts of polytetrahydrofuran ether glycol, 20 parts of isocyanate, 12 parts of hydroxyl-terminated polydimethylsiloxane, 8 parts of 1,4-butanediol, 0.7 parts of catalyst;

[0094] The molecular weight of the polytetrahydrofuran ether glycol is 2000.

[0095] S2, preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide: take 9,10-dihydro-9-oxanthrene and maleic acid in step S1 by weight, mix with 12 parts by weight of dimethylbenzene, heat to 140°C under N2 atmosphere and continuously stir for 4h, extract the lower solution with ethanol, filter after white solid precipitates, and vacuum dry to obtain DOPO-maleic acid; then dissolve the DOPO-maleic acid in 15 parts by weight of dimethylbenzene, add polyol and antioxidant by weight, heat to the white product disappears and evaporate water, add acid catalyst when the water evaporation rate is stable until the acid value is 4mg KOH / g, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is obtained after the reaction is completed;

[0096] The polyol is 1,6-hexanediol, the antioxidant is dilauryl thiodipropionate, and the acid catalyst is p-toluenesulfonic acid with a mass fraction of 98wt%;

[0097] S3, preparation of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole: take 2-(2,4-dihydroxyphenyl)-2H-benzotriazole dissolved in 4 parts by weight of triethylamine by weight, stir for 5min to obtain a first mixture, mix acryloyl chloride and 22 parts of tetrahydrofuran to obtain a dispersion of acryloyl chloride, add the dispersion to the first mixture, stir for 8h under ice bath conditions to carry out the reaction to obtain a crude product, then wash the crude product with saturated sodium bicarbonate solution, evaporate the organic solvent in the system, wash with anhydrous ethanol, and vacuum dry to obtain light yellow crystals of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0098] S4, Preparation of polyurethane resin prepolymer: Take polytetrahydrofuran ether diol by weight parts, vacuum dehydrated at 120℃ for 2h, after dehydration, fill nitrogen to reduce temperature, when the temperature drops to 80℃, add isocyanate and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole prepared by step S3 by weight parts, control the content of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole to be 0.5% of the total mass of the system, keep the reaction for 2h, then reduce the temperature to room temperature, obtain polyurethane resin prepolymer;

[0099] The isocyanate is 4,4'-dicyclohexyl methane diisocyanate;

[0100] S5, Take hydroxyl-terminated polydimethylsiloxane and 66 parts by weight of tetrahydrofuran by weight parts, stir and disperse uniformly after the hydroxyl-terminated polydimethylsiloxane is fully swollen, add the polyurethane resin prepolymer prepared in step S4, stir at room temperature for 2h, then heat to 80℃ for reaction for 7h, add 1,4-butanediol, catalyst and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide prepared by step S2 by weight parts, 80℃ for 2h, obtain reinforced polyurethane resin;

[0101] The catalyst is dibutyltin dilaurate.

[0102] The application of the above-mentioned reinforced polyurethane resin for photovoltaic frame includes the following steps:

[0103] (1) Hang the fiber felt and the glass fiber yarn drum on the multi-layer yarn frame, pass the glass fiber and the glass fiber felt through the frame mold at the same time, enter the mold core, wherein the glass fiber felt is at the outside and the glass fiber is at the inside;

[0104] (2) Inject the reinforced polyurethane resin prepared above into the mold fixed with glass fiber and fiber felt through the injection machine, add phosphate and silane coupling agent, stir and mix uniformly, stir at 4000r / min for 2.5h, then heat in sections, the first section heating temperature is 80℃, the time is 2h, the second section heating temperature is 130℃, the time is 3h, finally, extrude and form at a pulling speed of 0.3m / min, obtain fiber reinforced polyurethane resin composite material for photovoltaic frame;

[0105] The addition amount of the phosphate is 0.5wt% of the mass of the reinforced polyurethane resin, the addition amount of the silane coupling agent is 4wt% of the mass of the polyurethane resin, and the silane coupling agent is kh792;

[0106] The content of the glass fiber is 55wt% of the mass of the fiber-reinforced polyurethane resin composite, and the content of the fiber mat is 10wt% of the mass of the fiber-reinforced polyurethane resin composite.

[0107] Comparative Example 1

[0108] The difference from Example 1 is that no grafting reaction is carried out on the polyurethane main chain, that is, no 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added in Step 3, and no phosphorus-containing compound is grafted onto the polyurethane main chain; the specific steps are as follows:

[0109] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0110] Step 1, dissolve 1.5 parts of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole in 4 parts of triethylamine and stir for 5 min, pour a mixture of 0.9 parts of acryloyl chloride and 22 parts of tetrahydrofuran solution into the above obtained solution, then stir in an ice bath for 8 h, wash the obtained crude product with saturated sodium bicarbonate solution, evaporate the upper red-brown oily solution in the washing, then wash with anhydrous ethanol, and vacuum dry to obtain 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0111] Step 2, add 35 parts of polytetrahydrofuran ether diol (molecular weight 2000) to a three-necked flask with a stirrer and a thermometer, and perform vacuum dehydration at 120°C for 2 h; after dehydration is completed, nitrogen is filled to reduce the temperature, and when the temperature is reduced to 80°C, 17 parts of 4,4'-dicyclohexyl methane diisocyanate (HMDI) and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole obtained in Step 2 are added, the reaction is maintained for 2 h, and then the temperature is reduced to room temperature to obtain a polyurethane resin prepolymer;

[0112] Step 3, take 11 parts of hydroxyl-terminated polydimethylsiloxane and 66 parts of tetrahydrofuran and add them into a three-necked bottle equipped with a stirring paddle, a reflux condenser and an N2 inlet in sequence, and after the hydroxyl-terminated polydimethylsiloxane is fully swelled, it is stirred to be uniformly dispersed. The polyurethane resin prepolymer obtained in Step 2 is put into the hydroxyl-terminated polydimethylsiloxane solution; stirring is performed at room temperature for 2 hours, heating is performed to 80°C for 7 hours, then 9 parts of 1,4-butanediol and 0.8 parts of dibutyltin dilaurate are added, and the temperature is maintained at 80°C for 2 h to obtain a polyurethane resin.

[0113] The application of the above-mentioned reinforced polyurethane resin for a photovoltaic frame is the same as the preparation process of Example 1.

[0114] Comparative Example 2

[0115] The difference from Example 1 is that the polyurethane does not introduce 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole; the specific steps are as follows:

[0116] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0117] Step 1, 4 parts of 9,10-dihydro-9-oxanthrene, 2.5 parts of maleic acid and 12 parts of dimethylbenzene are added to the reactor, and the mixture is heated to 140°C under nitrogen atmosphere and continuously stirred for 4h, then the lower solution is extracted with ethanol, and after the white solid is precipitated, it is filtered and vacuum dried to obtain DOPO-maleic acid, then the obtained DOPO-maleic acid is dissolved in 15 parts of dimethylbenzene, 1.5 parts of ethylene glycol and 0.2 parts of diphenylphosphine are added and heated to 150°C until the white product disappears and the water is evaporated. After the water evaporation rate is stable, 98wt% of p-toluenesulfonic acid is added until the acid value is 4.1mgKOH / g, and a yellow viscous liquid containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is obtained;

[0118] Step 2, 35 parts of polytetrahydrofuran ether diol (molecular weight 2000) are added to a three-necked flask with a stirrer and a thermometer, and vacuum dehydration is carried out at 120°C for 2h; after dehydration is completed, nitrogen is filled and the temperature is lowered, and when the temperature is lowered to 80°C, 17 parts of 4,4'-dicyclohexyl methane diisocyanate are added to the three-necked flask. After maintaining the reaction for 2h, the temperature is lowered to room temperature to obtain a polyurethane resin prepolymer;

[0119] Step 3, 11 parts of hydroxyl-terminated polydimethylsiloxane and 66 parts of tetrahydrofuran are sequentially added to a three-necked flask equipped with a stirring paddle, a reflux condenser and an N2 inlet, and after the hydroxyl-terminated polydimethylsiloxane is fully swollen, it is stirred to disperse uniformly, then the obtained polyurethane resin prepolymer in step 3 is added, and stirred at room temperature for 2 hours, heated to 80°C and reacted for 7 hours, then 9 parts of 1,4-butanediol and 0.8 parts of dibutyltin dilaurate prepared in step 1 are added, and the temperature is maintained at 80°C for 2h to obtain the polyurethane resin.

[0120] The application of the above-mentioned reinforced polyurethane resin for a photovoltaic frame is the same as the preparation process of Example 1.

[0121] Comparative Example 3

[0122] The difference from Example 1 is that the hydroxyl-terminated polydimethylsiloxane and the polyol are not embedded as flexible chain segments into the main chain; the specific steps are as follows:

[0123] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0124] Step 1, 4 parts of 9, 10-dihydro-9-oxa-xanthene, 2.5 parts of maleic acid and 12 parts of xylene were added into a reactor, the mixture was heated to 140°C under nitrogen atmosphere and continuously stirred for 4h, then the lower solution was extracted with ethanol, the white solid was filtered out after precipitation, and dried under vacuum to obtain DOPO-maleic acid, then the obtained DOPO-maleic acid was dissolved in 15 parts of xylene, 1.5 parts of ethylene glycol and 0.2 parts of diphenyl phosphine were added and heated to 150°C until the white product disappeared and water was evaporated. After the water evaporation rate was stable, 98wt% of p-toluenesulfonic acid was added until the acid value was 4.1mgKOH / g, to obtain a yellow viscous liquid containing 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide;

[0125] Step 2, 1.5 parts of 2-(2, 4-dihydroxyphenyl)-2H-benzotriazole were dissolved in 4 parts of triethylamine and stirred for a few minutes, then a mixture of 0.9 parts of acryloyl chloride and 22 parts of tetrahydrofuran solution was poured into the obtained solution, then stirred in an ice bath for 8h, the obtained crude product was washed with saturated sodium bicarbonate solution, the upper red-brown oily solution in the washing was evaporated, then washed with anhydrous ethanol, and dried under vacuum to obtain 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole;

[0126] Step 3, 35 parts of polytetrahydrofuran ether diol (molecular weight 2000) were added to a three-necked flask with a stirrer and a thermometer, vacuum dehydration was carried out at 120°C for 2h; after dehydration, nitrogen was filled to reduce the temperature, when the temperature dropped to 80°C, 17 parts of 4, 4'-dicyclohexyl methane diisocyanate and the obtained 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole in step 2 were added, the reaction was maintained for 2h, then cooled to room temperature to obtain a polyurethane resin prepolymer;

[0127] Step 4, the yellow viscous liquid prepared in step 1, 9 parts of 1, 4-butanediol and 0.8 parts of dibutyltin dilaurate were added to the obtained polyurethane resin prepolymer in step 3, and the temperature was maintained at 80°C for 2h to obtain a polyurethane resin.

[0128] The application of the above-mentioned polyurethane resin for photovoltaic frame reinforcement is the same as the preparation process of Example 1.

[0129] Comparative Example 4

[0130] The difference from Example 1 is that no grafting reaction is carried out on the polyurethane main chain, i.e. no 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added in step 3, no phosphorus-containing compound is grafted onto the polyurethane main chain; and the polyurethane does not introduce 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole; and the terminal hydroxyl polydimethylsiloxane and polyol are not embedded as flexible chain segments into the main chain; the specific steps are as follows:

[0131] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0132] Step 1, 35 parts of polytetrahydrofuran ether diol (molecular weight 2000) is added to a three-necked flask with a stirrer and a thermometer, vacuum drying at 120℃ for 2h; after water removal, nitrogen is filled to reduce the temperature, when the temperature drops to 80℃, 17 parts of 4,4'-dicyclohexyl methane diisocyanate is added to keep the reaction for 2h, and then the temperature is reduced to room temperature to obtain a polyurethane resin prepolymer;

[0133] Step 2, 9 parts of 1,4-butanediol and 0.8 parts of dibutyltin dilaurate are added to the above polyurethane resin prepolymer, and the temperature is kept at 80℃ for 2h to obtain the polyurethane resin.

[0134] The application of the above-mentioned reinforced polyurethane resin for a photovoltaic frame is the same as the preparation process of Example 1.

[0135] Comparative Example 5

[0136] The difference between Example 1 is that after the reinforced polyurethane resin is injected into the mold fixed with glass fibers and fiber felt, no silane coupling agent is added; the specific steps are as follows:

[0137] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0138] The preparation process is the same as Example 1.

[0139] The application of the above-mentioned reinforced polyurethane resin for a photovoltaic frame comprises the following steps:

[0140] (1) Hang the fiber felt with the glass fiber yarn cylinder on the multi-layer yarn rack, pass the glass fiber and the glass fiber felt through the frame mold at the same time, and enter the mold core, wherein the glass fiber felt is on the outside and the glass fiber is on the inside;

[0141] (2) The above-mentioned polyurethane resin is injected into the mold through the glue injection machine, 1wt% of phosphate ester is added to the polyurethane resin, and stirred at 3500r / min for 2.5h, then segmented heating, the first heating temperature is 100℃, the time is 2h, the second heating temperature is 130℃, the time is 3h, finally, the fiber reinforced polyurethane resin composite material for photovoltaic frame is obtained by pultrusion at a pulling speed of 0.4m / min. The glass fiber content in the prepared fiber reinforced polyurethane resin composite material is 50wt%, and the fiber felt content is 15wt%.

[0142] Comparative Example 6

[0143] The difference from Example 1 is that after the reinforced polyurethane resin is injected into the mold fixed with the glass fiber and the fiber mat, no phosphate ester is added; the specific steps are as follows:

[0144] A preparation method of a reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0145] The preparation process is the same as that of Example 1.

[0146] The application of the above-mentioned reinforced polyurethane resin for a photovoltaic frame, comprising the following steps:

[0147] (1) Hang the fiber mat and the glass fiber yarn cylinder on the multi-layer yarn frame, pass the glass fiber and the glass fiber mat through the frame mold at the same time, and enter the mold core, wherein the glass fiber mat is at the outer side and the glass fiber is at the inner side;

[0148] (2) The above-mentioned polyurethane resin is injected into the mold through the glue injection machine, kh560 of 2.5wt% of the mass of the polyurethane resin is added, and stirring is carried out at 3500r / min for 2.5h, then segmented heating, the first heating temperature is 100℃, the time is 2h, the second heating temperature is 130℃, the time is 3h, finally, the pultrusion speed is 0.4m / min, and the fiber reinforced polyurethane resin composite material for a photovoltaic frame is obtained by extrusion molding, the glass fiber content in the prepared fiber reinforced polyurethane resin composite material is 50wt%, and the fiber mat content is 15wt%.

[0149] The performance of the fiber reinforced polyurethane resin composite material prepared in the examples and comparative examples is tested, and the results are shown in Table 1.

[0150] Among them, the flame retardant performance test is carried out according to the UL94 standard, the tensile strength test is carried out according to the ISO 527-4 standard, the contact angle test is carried out according to the GB / T 24368-2009 standard, and the ultraviolet shielding test is carried out according to the EN 13758-2-2003 standard.

[0151] Table 1 Performance test of fiber reinforced polyurethane resin composite material prepared in examples and comparative examples

[0152]

[0153]

[0154] It can be seen from the above test results that the fiber reinforced polyurethane resin composite provided by the technical scheme is prepared by the reaction of polytetrahydrofuran ether diol and isocyanate as a polyurethane prepolymer, the prepared 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is used to chemically graft the phosphorus-containing compound to the polyurethane main chain, the hydroxyl-terminated polydimethylsiloxane and polyol are used as part of the flexible segment to embed the polyurethane main chain, and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole is introduced to increase the ultraviolet resistance of the polyurethane resin, the prepared polyurethane resin has a good application prospect in the photovoltaic frame field, and finally the polyurethane resin is injected into a mold with glass fibers to prepare a composite material for a photovoltaic frame by a pultrusion process, which proves that the composite material indeed has good flame retardant performance, water resistance and ultraviolet resistance, and meets the strength requirements of the photovoltaic frame material.

[0155] Although the present application has been specifically shown and described with reference to preferred embodiments, it is understood that various changes in form and details can be made therein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A method for preparing a reinforced polyurethane resin for a photovoltaic frame, characterized in that: The following steps are involved: S1. Preparation of raw materials: comprising the following raw materials in parts by weight: 3-5 parts of 9,10-dihydro-9-xanthene, 2-3 parts of maleic acid, 1-2 parts of polyol, 0.1-0.3 parts of antioxidant, 1-2 parts of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 0.5-1 parts of acryloyl chloride, 30-40 parts of polytetramethylene ether glycol, 15-20 parts of isocyanate, 10-12 parts of hydroxy-terminated polydimethylsiloxane, 8-10 parts of 1,4-butanediol, and 0.6-1 parts of catalyst; S2. Preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide: 9,10-dihydro-9-oxanthene and maleic acid in step S1 are taken by weight, 10-12 parts by weight of xylene are added and mixed, and the mixture is heated and continuously stirred under an inert atmosphere. The lower layer solution is extracted with ethanol, and after a white solid is precipitated, it is filtered and vacuum dried to obtain DOPO-maleic acid; then, DOPO-maleic acid is dissolved in 10-15 parts by weight of xylene, and a polyol and an antioxidant are added by weight, and the mixture is heated until the white product disappears and water is evaporated. After the water release rate stabilizes, an acid catalyst is added, and after the reaction is completed, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is obtained; S3. Preparation of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole: dissolving 2-(2,4-dihydroxyphenyl)-2H-benzotriazole in 4-6 parts by weight of triethylamine to obtain a first mixed solution; mixing acryloyl chloride and 18-22 parts by weight of tetrahydrofuran to obtain a dispersion of acryloyl chloride; adding the dispersion to the first mixed solution; stirring in an ice bath to react to obtain a crude product; washing the crude product with a saturated sodium bicarbonate solution; evaporating the organic solvent in the system; washing with anhydrous ethanol; and vacuum drying to obtain light yellow crystals of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole; S4. Preparation of a polyurethane resin prepolymer: vacuum-drying polytetramethylene glycol by weight, adding isocyanate and the 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole prepared in step S3 by weight, controlling the content of 2-(2-hydroxy-4-acryloyl)-2H-benzotriazole to 0.5%-1% of the total mass of the system, maintaining the reaction for 2-3 hours, and then cooling to room temperature to obtain a polyurethane resin prepolymer; S5. Mix terminal hydroxyl polydimethylsiloxane and 60-66 parts by weight of tetrahydrofuran, stir and disperse evenly after the terminal hydroxyl polydimethylsiloxane is fully swollen, add the polyurethane resin prepolymer prepared in step S4, stir at room temperature, and then heat to react, add 1,4-butanediol, a catalyst, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide prepared in step S2, and heat-treat to obtain a reinforced polyurethane resin.

2. The method for preparing a reinforced polyurethane resin for photovoltaic frames according to claim 1, characterized in that: In step S1, the polyol is any one of ethylene glycol, propylene glycol, 1,5-pentanediol or 1,6-hexanediol.

3. The method for preparing a reinforced polyurethane resin for photovoltaic frames according to claim 1, characterized in that: In step S1, the antioxidant is any one of diphenylphosphine, didodecanol thiodipropionate and 2,6-di-tert-butyl-4-methylphenol.

4. The method for preparing a reinforced polyurethane resin for photovoltaic frames according to claim 1, characterized in that: In step S1, the catalyst includes but is not limited to at least one of dibutyltin dilaurate, stannous octoate or triethylenediamine.

5. The use of a reinforced polyurethane resin for photovoltaic frames according to claim 1, characterized in that: The following steps are involved: The reinforced polyurethane resin prepared in step S5 is injected into a mold fixed with glass fiber and fiber mat, phosphate ester and silane coupling agent are added and stirred and mixed, and the composite material obtained above is pultruded under heating conditions to obtain a fiber-reinforced polyurethane resin composite material.

6. The use of a reinforced polyurethane resin for photovoltaic frames according to claim 5, characterized in that: The amount of the phosphate added is 0.5wt%-1.5wt% of the mass of the reinforced polyurethane resin, and the amount of the silane coupling agent added is 1.5wt%-4wt% of the mass of the polyurethane resin.

7. The use of a reinforced polyurethane resin for photovoltaic frames according to claim 5, characterized in that: The content of the glass fiber is 50wt%-55wt% of the mass of the fiber-reinforced polyurethane resin composite material, and the content of the fiber mat is 10-15wt% of the mass of the fiber-reinforced polyurethane resin composite material.

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