A high weather-resistant photovoltaic enhanced prepreg epoxy resin and its preparation method and application

Abstract

The present invention relates to a highly weather-resistant photovoltaic enhanced prepreg epoxy resin and a preparation method and application thereof, comprising an ester ring epoxy resin, a glycidyl ether epoxy resin, a reactive diluent, an organosilicon-modified epoxy resin, a photoinitiator, a thermal cationic curing agent, a UV absorber and a thixotropic agent. The present invention has excellent weather resistance and light transmission performance, and at the same time has high strength, and can meet the packaging requirements of lightweight photovoltaic modules.

Description

Technical Field

[0001] The invention belongs to the field of lightweight photovoltaic components, and particularly relates to a highly weather-resistant photovoltaic enhanced prepreg epoxy resin and a preparation method and application thereof. Background Art

[0002] Lightweight photovoltaic modules are widely used in factory roofs and sound barriers because of their low load requirements, good flexibility, and ability to be attached to curved surfaces. In order to increase the strength of photovoltaic modules and reduce the hidden cracks in the cells during installation and transportation, glass fiber reinforcement layers are usually added to the front and back panels. The front panel reinforcement layer has high requirements for the light transmittance and weather resistance of the material. Composite materials usually include epoxy resin, acrylate, weather-resistant polyester, etc.

[0003] CN113845752B uses thermal cations to solve the problem of too high temperature and too long time for thermal curing, but simple light curing has a great influence on the shape and size thickness of the material, especially for coating prepreg, because of the scattering effect of glass fiber, the slower the resin cures in the later stage of the reaction. In addition, because its formula is all cycloaliphatic resin, the subsequent reaction activity is reduced, the molecular weight of its synthetic weathering product is limited, and its formula curing molecular weight and molecular weight distribution cannot be controlled, and the overall weather resistance will deteriorate.

[0004] CN115836100A discloses a polymerizable composition of a mixed photocationic polymerization initiator, a thermal cationic polymerization initiator and a cationic polymerizable compound, which is used as a curing system for curing cycloester epoxy resin to obtain a good degree of curing. However, the patent does not make corresponding adjustments to the curing temperature, and the mixing of multiple curing agents will cause different types of resins to be mixed together, thereby reducing the light transmittance of the material.

[0005] CN111662434 A uses a photocurable cationic system to cure epoxy resin, but the subsequent thermal curing temperature is still relatively high and takes more than 2 hours, which cannot meet the packaging requirements of the photovoltaic industry. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a highly weather-resistant photovoltaic enhanced prepreg epoxy resin and a preparation method and application thereof. The epoxy resin has excellent weather resistance and light transmittance, and at the same time has high strength, which can meet the packaging requirements of lightweight photovoltaic modules.

[0007] The present invention provides a highly weather-resistant photovoltaic enhanced prepreg epoxy resin, which comprises the following components in parts by weight:

[0008] 40-80 parts of cycloester epoxy resin;

[0009] Glycidyl ether epoxy resin 10-20 parts;

[0010] Active diluent 5-10 parts;

[0011] 10-20 parts of silicone modified epoxy resin;

[0012] Photoinitiator 0.3-1 part;

[0013] 0.1-3 parts of photoacid generator;

[0014] UV absorber 0.5-2 parts;

[0015] Thixotropic agent 0.5-2 parts; The organosilicon-modified epoxy resin is obtained by reacting allyl organosilicon with a double-bond-containing epoxy resin under the action of an initiator.

[0016] Preferably, the allyl silicone includes one or more of 3-methacryloxypropyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltriethoxysilane, and trimethoxy(7-octen-1-yl)silane.

[0017] Preferably, the double bond-containing epoxy resin includes one or more of 2,2'-diallyl bisphenol A, 2,2'-diallyl bisphenol S, and epoxy acrylate oligomers.

[0018] Preferably, the initiator includes one or more of azobisisobutyronitrile, dicumyl peroxide, and benzoyl peroxide.

[0019] Preferably, the weight proportion of the allyl silicone is 10-30 parts; the weight proportion of the epoxy resin containing double bonds is 70-90 parts; and the added amount of the initiator is 0.1%-0.3% of the total mass of the reaction raw materials (i.e., the sum of the mass of the allyl silicone and the epoxy resin containing double bonds).

[0020] Preferably, the ester ring epoxy resin includes one or more of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, bis((3,4-epoxycyclohexyl)methyl)adipate, and 1,4-cyclohexanedimethanol bis(3,4-epoxycyclohexanecarboxylic acid) ester.

[0021] Preferably, the glycidyl ether epoxy resin includes one or more of 3,3'5,5'-tetramethylbiphenyl bisphenol diglycidyl ether and bisphenol S diglycidyl ether.

[0022] Preferably, the reactive diluent includes one or more of 1,2-epoxy-4-vinylcyclohexane and 3,4-epoxycyclohexyl methacrylate.

[0023] Preferably, the photoinitiator includes one or more of diaryl iodonium salts, triaryl sulfonium salts, hexafluoroantimonate sulfonium salts, and aromatic diazonium salts. More preferably, the photoinitiator is triaryl hexafluoroantimonate sulfonium salt, which has little effect on color, high activity, and is conducive to the curing reaction.

[0024] Preferably, the photoacid generator includes one or more of pentafluorophenyl boric acid sulfonium salt and (4-methoxyphenyl) diphenyl sulfonium trifluoromethanesulfonate.

[0025] Preferably, the UV absorber includes one or more of 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxy-phenol and 2-[4,6-bis(2,4-methylphenyl-diphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)phenol. More preferably, the UV absorber is 2-[4,6-bis(2,4-methylphenyl-diphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)phenol.

[0026] Preferably, the thixotropic agent is fumed silica.

[0027] The present invention also provides a method for preparing a highly weather-resistant photovoltaic enhanced prepreg epoxy resin, comprising the following steps:

[0028] (1) Allyl silicone and double-bond epoxy resin are dissolved in an organic solvent and reacted under the action of an initiator to obtain silicone-modified epoxy resin;

[0029] (2) Mixing the raw material components in an organic solvent according to weight proportions, stirring and defoaming to obtain a highly weather-resistant photovoltaic enhanced prepreg epoxy resin.

[0030] Preferably, the organic solvent in step (1) is xylene; and the organic solvent in step (2) is acetone.

[0031] Preferably, the mass ratio of the organic solvent to the reaction raw materials in step (1) is 1:1.

[0032] Preferably, the reaction temperature in step (1) is 70-80° C., and the reaction time is 50 min-60 min.

[0033] Preferably, the solid content of the raw material components in step (2) is 70-80%.

[0034] The present invention also provides an application of a highly weather-resistant photovoltaic enhanced prepreg epoxy resin in a lightweight photovoltaic module.

[0035] Beneficial Effects

[0036] (1) The present invention uses an ester ring epoxy resin and a glycidyl ether epoxy resin to blend to prepare an epoxy resin with good weather resistance, moisture and heat resistance, high heat resistance and high reaction activity, which can match the secondary curing conditions of 140°C for 20 minutes when molding lightweight photovoltaic modules;

[0037] (2) The present invention uses allyl silicone to react with double-bond epoxy resin in one step to generate epoxy resin containing silicone groups, which further improves the weather resistance of the prepreg prepared from the resin of the present invention;

[0038] (3) The present invention uses a photoinitiator and a photoacid generator to achieve dual-stage curing: the photoinitiator generates excited cations and free radicals under UV irradiation, wherein the free radicals can react with the ester ring group to generate new free radicals, thereby initiating chain polymerization; the photoacid generator undergoes a photodissociation reaction under the action of the above-mentioned excited cations, which can complete the polymerization reaction and achieve a cross-linked network structure;

[0039] (4) The active diluent added in the present invention has a bifunctional group, which can reduce the viscosity of the system during the first stage of cationic curing. During the second stage of curing, the excited cations generated by the photoinitiator react with the active diluent to produce new cationic centers, thereby initiating a chain polymerization reaction, thereby improving the crosslinking degree of the product and increasing the heat resistance and weather resistance of the prepreg prepared from the resin of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0041] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0042] Table 1 Formula of silicone-modified epoxy resin (parts by weight)

[0043]

[0044] The preparation method of organosilicon-modified epoxy resin comprises the following steps:

[0045] 3-Methacryloxypropyltrimethoxysilane and 2,2'-diallylbisphenol A were added to xylene in proportion, the temperature was raised to 70°C in a nitrogen atmosphere, and the mixture was heated and stirred for 20 minutes. An initiator solution (the solvent is xylene) was added dropwise, and the solution was added after 10 minutes. The solution was stirred for another 20 minutes until a viscous separation layer appeared, so that the silicon content of the organosilicon-modified epoxy resin was between 1% and 5%. The solvent and the remaining reaction raw materials were removed by distillation under reduced pressure to obtain an organosilicon-modified epoxy resin.

[0046] Table 2 Example formulation (parts by weight)

[0047]

[0048] Table 3 Comparative Example Formula (parts by weight)

[0049]

[0050] A method for preparing a highly weather-resistant photovoltaic enhanced prepreg epoxy resin comprises the following steps:

[0051] The raw material components were mixed in proportion, the solvent was acetone, stirred for 20 minutes, the solid content was adjusted to 70%~80%, and defoamed for 20 minutes. The test viscosity was controlled at 20~300 cP.

[0052] Use wet glue coating line, use 160g / m 2 Glass fiber twill fabric, roll-coated with the above epoxy resin, and remove the solvent in the drying oven, controlling the glue content to 100~110g / m 2 After the solvent evaporates, it is cured in a UV oven (100-120°C) for 1 minute to obtain a prepreg, with the UV wavelength being 250-380nm. After the prepreg is prepared, it is post-cured at 140°C for 20 minutes under vacuum conditions to obtain a composite material, and the reliability of the composite material is tested.

[0053] Table 4 Test results of example formulations

[0054]

[0055] Table 5 Comparative Example Formula Test Results

[0056]

[0057] It can be seen from Table 4 and Table 5 that the composite materials prepared by the epoxy resins of Examples 1-9 have excellent weather resistance and light transmission properties. It can be seen from Comparative Examples 1-4 that when no glycidyl ether epoxy resin, no active diluent, no organosilicon-modified epoxy resin, and no photoinitiator are added, the performance of the composite materials is poor, among which the absence of the organosilicon-modified epoxy resin has a greater impact.

Claims

1. A highly weather-resistant photovoltaic enhanced prepreg epoxy resin, characterized in that: In parts by weight, it comprises the following components: The allyl silicone comprises one or more of 3-methacryloxypropyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltriethoxysilane and trimethoxy(7-octen-1-yl)silane; the epoxy resin comprising double bonds comprises one or more of 2,2'-diallylbisphenol A, 2,2'-diallylbisphenol S and epoxy acrylate oligomer; the initiator comprises one or more of The initiator includes one or more of azobisisobutyronitrile, diisopropylbenzene peroxide, and benzoyl peroxide; the photoinitiator includes one or more of diaryliodonium salts, triarylsulfonium salts, sulfonium hexafluoroantimonate salts, and aromatic diazonium salts; the photoacid generator includes one or more of pentafluorophenylborate sulfonium salts and (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate; the active diluent includes one or more of 1,2-epoxy-4-vinylcyclohexane and 3,4-epoxycyclohexyl methacrylate.

2. The epoxy resin according to claim 1, characterized in that: The weight proportion of the allyl silicone is 10-30 parts; the weight proportion of the double-bond-containing epoxy resin is 70-90 parts; and the added amount of the initiator is 0.1%-0.3% of the total mass of the reaction raw materials.

3. The epoxy resin according to claim 1, characterized in that: The ester ring epoxy resin includes one or more of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexyl methyl ester, bis((3,4-epoxycyclohexyl)methyl)adipate, and 1,4-cyclohexanedimethanol bis(3,4-epoxycyclohexanecarboxylic acid) ester; the glycidyl ether epoxy resin includes one or more of 3,3'5,5'-tetramethylbiphenyl bisphenol diglycidyl ether and bisphenol S diglycidyl ether.

4. The epoxy resin according to claim 1, characterized in that: The UV absorber includes one or more of 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxy-phenol and 2-[4,6-bis(2,4-methylphenyl-diphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)phenol.

5. The epoxy resin according to claim 1, characterized in that: The thixotropic agent is fumed silica.

6. A method for preparing a highly weather-resistant photovoltaic enhanced prepreg epoxy resin as claimed in any one of claims 1 to 5, comprising the following steps: (1) dissolving allyl silicone and double-bond-containing epoxy resin in an organic solvent and reacting them under the action of an initiator to obtain silicone-modified epoxy resin; (2) Mixing the raw material components in an organic solvent according to weight, stirring and defoaming to obtain a highly weather-resistant photovoltaic enhanced prepreg epoxy resin.

7. Use of the highly weather-resistant photovoltaic enhanced prepreg epoxy resin as claimed in any one of claims 1 to 5 in a lightweight photovoltaic module.

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