A flame-retardant epoxy composite material, its preparation method and application

Abstract

The present invention belongs to the technical field of lightweight flexible photovoltaic modules, and relates to a flame-retardant epoxy composite material, a preparation method and an application thereof. The composite material comprises the following components in parts by weight: bisphenol-type epoxy resin, aromatic epoxy resin, halogen-containing epoxy resin, curing agent A, curing agent B, curing accelerator, flame retardant A, flame retardant B, UV absorber, light stabilizer, antioxidant, and nano-coated montmorillonite. Without affecting the light transmittance, the present invention adds nano-coated montmorillonite. When the temperature is high, the flame retardant cooperates with the montmorillonite to generate an insulating carbon layer. The montmorillonite serves as a reinforcing medium for the insulating carbon layer, playing a role in condensed-phase flame retardancy, insulating and cooling, and slowing down the thermal degradation of the resin, thereby slowing down the flame propagation and effectively improving the flame retardant performance, which is applicable to lightweight flexible modules with high flame retardancy requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightweight flexible photovoltaic modules, and particularly relates to a flame-retardant epoxy composite material, a preparation method thereof, and an application thereof. Background Art

[0002] With the wide application of lightweight flexible photovoltaic modules in the fields of BIPV and BAPV, new requirements for the flame retardancy of the encapsulation materials of lightweight flexible photovoltaic modules have been put forward. For the field of public buildings with limited area, the building covering should reach a level above UL746C. At present, the grades of most modules on the market are at level C.

[0003] WO2023212989A1 uses acrylate powder resin, and an ETFE film is used on the surface of the module. Although the ETFE film itself is flame-retardant, because the thickness used is below 50 μm, it will quickly melt and fail under a high-power flame of >15 kW / m 2 Therefore, the flame retardancy design of the module according to the building covering has not been improved.

[0004] CN104830025A uses a matrix composed of two resins, namely organosilicon fluorine random acrylate copolymer and alicyclic epoxy resin, and uses modified SiO2 for reinforcement to increase the heat distortion temperature of the material, reduce the water absorption, and improve the scratch resistance. However, the alicyclic curing temperature is high and the curing time is long, which is only applicable to the field of electronic product encapsulation, and the flame retardant performance is not characterized therein.

[0005] CN115466565B uses polyurethane acrylate to prepare a composite material for encapsulating modules by a two-step method. However, the carbon content of the main chain is low, and it cannot reach the flame retardant grade of building coverings except by adding pure halogen flame retardants. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a flame-retardant epoxy composite material, a preparation method thereof, and an application thereof. The composite material effectively improves the flame retardant performance and is applicable to lightweight flexible photovoltaic modules with high flame retardancy requirements.

[0007] The present invention provides a flame-retardant epoxy composite material, which includes the following components in parts by weight:

[0008]

[0009]

[0010] Among them, the nano-coated montmorillonite includes the following components:

[0011]

[0012] Preferably, the bisphenol epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol S epoxy resin, and bisphenol F epoxy resin.

[0013] Preferably, the aromatic epoxy resin includes one or more of triphenyl glycidyl ether methane, triglycidyl p-aminophenol, N,N,N,N-tetraglycidyl-4,4-diaminodiphenylmethane, and 4-(diglycidylamino)phenyl glycidyl ether. More preferably, the aromatic epoxy resin is triglycidyl p-aminophenol.

[0014] Preferably, the halogen-containing epoxy resin includes one or more of DGEBA epoxy resin and high-bromine flame-retardant bisphenol A epoxy resin (bromine content > 20 wt%).

[0015] Preferably, the curing agent A is an aryl-containing curing agent, such as 4,4'-diaminodiphenylmethane (DDM), m-phenylenediamine (MPD), diaminodiphenyl sulfone (DDS), 4,4'-diamino-3,3',5',5-tetramethyldibenzophenone (DTB), etc.

[0016] Preferably, the curing agent B is a chlorine-containing aromatic diamine. To increase the fluidity of the curing agent and reduce the resin viscosity, such as diaminodichlorodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenyl sulfone (DCDPS), 2,4-dichloro-1,3-phenylenediamine (DCDA), etc.

[0017] Preferably, the curing accelerator is a boron-amine complex accelerator. More preferably, the ligand of boron trifluoride in the boron-amine complex is one of n-hexylamine, monoethylamine, aniline, diethylamine, piperidine, triethylamine, and aniline, and most preferably boron trifluoride ethylamine.

[0018] Preferably, the flame retardant A is hexaphenoxycyclotriphosphazene.

[0019] Preferably, the flame retardant B is a DOPO derivative, such as one of DOPO-hydroquinone, DOPO-phenyl vinyl phosphate, and DOPO-bisphenol A, or 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide.

[0020] Preferably, the UV absorber includes one or more of triazine-based UV absorbers UV1164, UV1577, and UV400.

[0021] Preferably, the light stabilizer includes one or more of benzotriazole light stabilizers UV1130 and UV928.

[0022] Preferably, the antioxidant includes one or more of hindered phenol antioxidants 1076, 1098, and 1010.

[0023] Preferably, the hydroxy acrylate includes one or more of 2-hydroxyethyl acrylate, hydroxypropyl methacrylate, and pentaerythritol triacrylate.

[0024] Preferably, the coating monomer includes one or more of 2,2'-diallyl bisphenol A, 2,2'-diallyl bisphenol S, and epoxy acrylate.

[0025] Preferably, the diluent includes one or more of methyl methacrylate, butyl methacrylate, and isobornyl methacrylate.

[0026] Preferably, the interface treatment agent includes one or more of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltriethoxysilane.

[0027] Preferably, the solvent is anhydrous ethanol.

[0028] The present invention also provides a method for preparing a flame retardant epoxy composite material, comprising the following steps:

[0029] (1) According to the ratio, nano-montmorillonite is ultrasonically dispersed in a solvent to obtain a nano-montmorillonite solution; then, hydroxy acrylate, coating monomer, diluent, and interface treatment agent are added to the nano-montmorillonite solution, and after the temperature is raised to 70-80° C., an initiator solution is added to react, and after the reaction, the solvent is evaporated and dried to obtain nano-coated montmorillonite;

[0030] (2) Add bisphenol epoxy resin, aromatic epoxy resin, halogen-containing epoxy resin, flame retardant A, flame retardant B, UV absorber, light stabilizer, and antioxidant into a stirred tank according to the proportion, heat to 120-130° C., and stir to obtain main agent A;

[0031] (3) Mix and grind curing agent A, curing agent B, curing accelerator, and the nano-coated montmorillonite in step (1), and then add them to the main agent A at 80-90° C. to obtain a flame retardant epoxy composite material.

[0032] Preferably, the initiator in step (1) is one or more of benzoyl peroxide, azobisisobutyronitrile, dicumyl peroxide, tert-butyl hydroperoxide, and tert-butyl perbenzoate; the amount of the initiator added is 0.1%-0.5% of the total mass of the system; and the solvent of the initiator solution is anhydrous ethanol.

[0033] The present invention also provides an application of a flame-retardant epoxy composite material in a lightweight flexible photovoltaic module.

[0034] Beneficial effects

[0035] (1) Without affecting the light transmittance, the present invention adds nano-coated montmorillonite. At high temperatures, the flame retardant cooperates with montmorillonite to form a heat-insulating carbon layer. Montmorillonite serves as a reinforcing medium for the heat-insulating carbon layer, playing a role in condensed-phase flame retardancy, insulating and cooling, slowing down the thermal degradation of the resin, and thus slowing down the flame propagation, effectively improving the flame retardancy performance, and is applicable to lightweight flexible components with high flame retardancy requirements.

[0036] (2) The present invention uses curing agent B to lower the melting point of curing agent A, which is beneficial to resin blending. With the cooperation of a curing accelerator, medium-temperature rapid curing is achieved.

[0037] (3) The present invention uses a halogen-containing epoxy resin as a diluent, which cooperates to reduce the viscosity of the resin system. After the reaction, the stable halogen side groups can cause the molecular chain to isomerize rapidly, delaying the degradation of the epoxy resin at high temperatures.

[0038] (4) The present invention uses flame retardant B and flame retardant A to synergistically enhance the effect, with good compatibility and no migration under high temperature and high humidity conditions. Specific Embodiments

[0039] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not 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 also fall within the scope defined by the appended claims of this application.

[0040] The reagents, methods, and equipment used in the present invention are all conventional reagents, methods, and equipment in the technical field unless otherwise specified.

[0041] Table 1 Formulation of Nano-Coated Montmorillonite (parts by weight)

[0042] Component Type Grade Source M1 M2 M3 Nanometer montmorillonite PGN-100 Nanocor Inc. 2 5 1 Coating monomer 2,2'-Diallylbisphenol S / Commercially available 10 5 10 Hydroxy acrylate 2-Hydroxyethyl acrylate Commercially available 25 25 28 Diluent Methyl methacrylate / Commercially available 10 10 10 Interface treatment agent 3-Methacryloxypropyltrimethoxysilane SICO-0174 Wacker 3 5 1 Initiator Dicumyl peroxide / Commercially available 0.3 0.3 0.3 Solvent Absolute ethanol Commercially available 50 50 50

[0043] The preparation method of the nano-coated montmorillonite includes the following steps:

[0044] 1. Ultrasonically disperse the nano-montmorillonite particles in absolute ethanol for 1 h to ensure uniform dispersion of the particles;

[0045] 2. Add hydroxyacrylate, coating monomer, diluent, and interfacial treatment agent to a three-necked flask in proportion and mix for 10 min under a nitrogen atmosphere, and raise the temperature of the reactants to 70 °C;

[0046] 3. Drop the initiator into the reactants within 20 min, and a viscous paste-like polymer is formed after 20 min;

[0047] 4. Subsequently, evaporate the solvent by rotary evaporation, dry and pulverize to obtain nano-coated montmorillonite.

[0048] Table 2 Formulation of Flame Retardant Epoxy Composite Materials (parts by weight)

[0049]

[0050] Table 3 Formulation of Flame Retardant Epoxy Composite Materials (parts by weight)

[0051]

[0052]

[0053] The preparation method of the flame retardant epoxy composite material includes the following steps:

[0054] (1) According to the ratio, add bisphenol type epoxy resin, aromatic epoxy resin, halogen-containing epoxy resin, flame retardant A, flame retardant B, UV absorber, light stabilizer, and antioxidant into a stirring kettle, heat up to 120°C and stir for 20 minutes. After stirring evenly, evacuate and gradually lower the temperature to 80°C to obtain main agent A;

[0055] (2) Mix and grind curing agent A, curing agent B, curing accelerator, and nano-coated montmorillonite (test the particle size with a scraper particle size meter to be 150μm), and then add it to main agent A at 80°C, stir and evacuate to obtain the flame retardant epoxy composite material.

[0056] Using the above flame retardant epoxy composite material to prepare prepreg and samples includes the following steps:

[0057] 1. Glue coating: Put the above epoxy resin into a glue coater to prepare a glue film with a grammage of 50 - 60 g / m 2 at a coating temperature of 80°C;

[0058] 2. Lamination: Unroll a 160 g / m 2 glass fiber woven fabric, use a 2-coat 1-impregnation process to prepare prepreg, with a roller pressing temperature of 100°C, 4 groups of roller pressing, and a roller line speed of less than 3 m / min to make prepreg;

[0059] 3. Fabrication of composite material samples: Package the prepreg, with a vacuum degree of 0.9 atm, cure at 143°C for 15 minutes, and test the properties of the composite material.

[0060] Table 4 Performance Test Results of Flame Retardant Epoxy Composite Materials

[0061]

[0062] Table 5 Performance Test Results of Flame Retardant Epoxy Composite Materials

[0063]

[0064]

Claims

1. A flame-retardant epoxy composite material, characterized in that: The composite material comprises the following components by weight parts: Among them, the nano-coated montmorillonite comprises the following components: It also includes an initiator; The preparation method of the nano-coated montmorillonite comprises the following steps: according to the ratio, ultrasonically disperse the nano-montmorillonite in a solvent to obtain a nano-montmorillonite solution; then add hydroxyacrylate, coating monomer, diluent, and interfacial treatment agent into the nano-montmorillonite solution, add the initiator solution for reaction after the temperature rises to 70-80 °C, spin-evaporate the solvent after the reaction, and dry to obtain the nano-coated montmorillonite; The coating monomer includes one or more of 2,2'-diallylbisphenol A, 2,2'-diallylbisphenol S, and epoxy acrylate; the diluent includes one or more of methyl methacrylate, butyl methacrylate, and isobornyl methacrylate; The bisphenol-type epoxy resin includes one or more of bisphenol A-type epoxy resin, bisphenol S-type epoxy resin, and bisphenol F-type epoxy resin; the aromatic epoxy resin includes one or more of triphenyl glycidyl ether methane, triglycidyl p-aminophenol, N,N,N,N-tetraglycidyl-4,4-diaminodiphenylmethane, and 4-(diglycidylamino)phenyl glycidyl ether; the curing agent A is EPON HPT1061; the curing agent B is diaminodichlorodiphenylmethane; the flame retardant A is hexaphenoxycyclotriphosphazene; the flame retardant B is one of DOPO-hydroquinone, DOPO-phenyl vinyl phosphate, DOPO-bisphenol A, and 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide.

2. The flame-retardant epoxy composite material according to claim 1, characterized in that: The halogen-containing epoxy resin is a high-bromine flame-retardant bisphenol A-type epoxy resin with a bromine content > 20 wt%.

3. The flame-retardant epoxy composite material according to claim 1, characterized in that: The curing accelerator is a boramine complex accelerator.

4. The flame-retardant epoxy composite material according to claim 1, wherein: The UV absorber includes one or more of triazine UV absorbers UV1164, UV1577, and UV400; the light stabilizer includes one or more of benzotriazole light stabilizers UV1130 and UV928; the antioxidant includes one or more of hindered phenol antioxidants 1076, 1098, and 1010.

5. The flame-retardant epoxy composite material according to claim 1, characterized in that: The hydroxyacrylate includes one or more of 2-hydroxyethyl acrylate, hydroxypropyl methacrylate, and pentaerythritol triacrylate.

6. The flame-retardant epoxy composite material according to claim 1, wherein: The interfacial treatment agent includes one or more of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltriethoxysilane; the solvent is anhydrous ethanol.

7. A preparation method of a flame-retardant epoxy composite material as described in any one of claims 1-6, comprising the following steps: (1) According to the ratio, ultrasonically disperse the nano-montmorillonite in a solvent to obtain a nano-montmorillonite solution; then add hydroxyacrylate, coating monomer, diluent, and interfacial treatment agent into the nano-montmorillonite solution, add the initiator solution for reaction after the temperature rises to 70-80 °C, spin-evaporate the solvent after the reaction, and dry to obtain the nano-coated montmorillonite; (2) According to the ratio, bisphenol epoxy resin, aromatic epoxy resin, halogen-containing epoxy resin, flame retardant A, flame retardant B, UV absorber, light stabilizer, and antioxidant are added to a stirring kettle and heated to 120 - 130 °C for stirring to obtain main agent A; (3) Curing agent A, curing agent B, curing accelerator, and the nano-coated montmorillonite in step (1) are mixed and ground, and then added to main agent A at 80 - 90 °C to obtain a flame-retardant epoxy composite material.

8. Application of a flame-retardant epoxy composite material as described in any one of claims 1 - 6 in a lightweight flexible photovoltaic module.

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