Fiber-reinforced composite photovoltaic module frame and preparation method thereof

Abstract

The present application provides a fiber-reinforced composite material photovoltaic module frame. The raw materials of the photovoltaic module frame include, by total weight: 30-45% resin mixture and 55-70% fiber; the components of the resin mixture include, by weight: 80-120 parts base resin, 1-4 parts curing agent, 1-3 parts lubricant, 5-15 parts flame retardant, 0.5-3 parts dispersant, and 5-35 parts inorganic filler; through system optimization, the fiber-reinforced composite material photovoltaic module frame of the present application has excellent mechanical strength, aging resistance and long service life.

Description

Technical Field

[0001] The present invention relates to the field of B29C70 / 00, and in particular to a fiber-reinforced composite material photovoltaic component frame and a preparation method thereof. Background Art

[0002] Currently, the primary material used for solar photovoltaic module frames is aluminum alloy. However, aluminum alloy photovoltaic module frames have the following issues: low tensile and flexural strength of the frames; poor insulation and PID resistance; a higher thermal expansion coefficient than glass, resulting in poor compatibility; poor impact and fatigue resistance, and prone to deformation; and high cost. Consequently, fiber-reinforced composite materials have gradually gained attention. Fiber-reinforced composite materials, when used as photovoltaic module frames, offer advantages such as high mechanical strength, excellent insulation, protection against the PID effect, strong corrosion resistance, a closer match to the thermal expansion coefficient of glass, and superior sealing. However, the mechanical strength and flexural modulus of fiber-reinforced composite materials are still insufficient to meet the 25-year service life requirement for photovoltaic module frames. Aging and weather resistance also have significant room for improvement. Furthermore, uneven fiber distribution significantly impacts the mechanical strength of the frame, restricting its application.

[0003] Chinese patent CN104761880B discloses a short fiber reinforced pultruded composite solar module frame and a preparation method thereof, wherein short fibers and continuous fibers are used to enhance the frame strength. However, the distribution of the short fibers is disordered, the impact resistance of the frame is still unstable and low, and the preparation process is also relatively complicated. Chinese patent CN103214807B discloses a fiberglass profile for a solar frame and a preparation method thereof. Unsaturated polyester resin and polyvinyl acetate are used as raw materials for the preparation of the profile. Since the ester bonds in the unsaturated polyester resin and polyvinyl acetate are easily hydrolyzed, the weather resistance and aging resistance of the frame are not high, and the water vapor transmittance is also relatively high. Summary of the Invention

[0004] In order to solve the above technical problems, the present application first provides a fiber-reinforced composite photovoltaic module frame.

[0005] Furthermore, based on the total weight, the raw materials of the photovoltaic module frame include: 30-45% of resin mixture and 55-70% of fiber.

[0006] Furthermore, the components of the resin mixture include, by weight, 80-120 parts of base resin, 1-4 parts of curing agent, 1-3 parts of lubricant, 5-15 parts of flame retardant, 0.5-3 parts of dispersant, and 5-35 parts of inorganic filler.

[0007] Furthermore, the base resin is selected from at least one of polyester resin, polyurethane resin, epoxy resin, phenolic resin, polypropylene resin, polyethylene resin, polystyrene resin, polyamide resin, melamine formaldehyde resin, and silicone resin.

[0008] Furthermore, the base resin includes at least one of polyester resin, polyurethane resin, polypropylene resin, polyethylene resin, polyamide resin and modified resins thereof.

[0009] In a preferred embodiment, the base resin comprises a polyurethane resin.

[0010] Furthermore, the polyurethane resin is a polyether polyurethane resin or a polyester polyurethane resin, which can be selected from any one or a combination of including but not limited to BASF: 1185A, 1195A, 60A, C80A, 95A, Bayer: 3055D, 3065D, 3970D, 3072D, 3080A, 385E, Taiwan Risheng: EME-98A, EMP-60D, EMP-95A, EMP-80A, EME-85AU.

[0011] Furthermore, the base resin also includes at least one of epoxy resin, phenolic resin, polystyrene resin, melamine formaldehyde resin, and silicone resin.

[0012] In a preferred embodiment, the base resin further comprises melamine formaldehyde resin in an amount of 25-60 wt % of the polyurethane resin. Polyurethane resin has good resistance to oxygen and UV radiation. However, when using only polyurethane resin as the matrix resin, its self-crosslinking degree is insufficient, resulting in a soft composite material and insufficient mechanical strength of the frame. The present application uses melamine formaldehyde resin to increase the system's crosslinking degree through the intertwining of the matrix resin's molecular chains and the interaction of functional groups in the system, thereby improving the system's anti-aging and weather resistance, accelerating the matrix resin's curing speed, and preventing the continuous fibers from shifting from their intended positions due to slow curing.

[0013] Furthermore, the melamine formaldehyde resin has a number average molecular weight of 10,000 to 100,000 and a viscosity of 1,000 to 9,500 mPa·s at 25°C. The molecular weight and viscosity of the melamine formaldehyde resin are further specified to regulate the crosslinking degree and curing speed of the system. When the molecular weight and viscosity are too high, there is a large interfacial tension with the fiber surface, resulting in poor wettability of the fiber in the system and the formation of pores within the composite material. When the molecular weight and viscosity are too low, insufficient crosslinking between the resins reduces the mechanical strength of the composite material framework.

[0014] Preferably, the melamine formaldehyde resin has a number average molecular weight of 20,000-60,000 and a viscosity at 25° C. of 2,000-6,000 mPa·s.

[0015] Furthermore, the curing agent is a peroxide or an azo substance.

[0016] Preferably, the curing agent is selected from any one of methyl ethyl ketone peroxide, cumene peroxide, and benzoyl peroxide.

[0017] Furthermore, the lubricant is selected from any one or a combination of C12-C18 fatty acids, fatty acid salts, fatty acid esters, polyethylene wax, silicone powder, and silicone oil.

[0018] Furthermore, the lubricant is selected from any one or a combination of stearic acid, stearate, pentaerythritol fatty acid ester, polyethylene wax, and silicone powder.

[0019] Furthermore, the flame retardant is at least one of a phosphorus-based flame retardant, a nitrogen-phosphorus-based flame retardant, a halogen-based flame retardant, and a fluorine compound.

[0020] Preferably, the flame retardant is selected from at least one of resorcinol bisphosphonate, tris(3-hydroxypropyl)phosphine oxide, triethyl phosphate, tributyl phosphate, triisooctyl phosphate, ammonium phosphate, polyphosphate, melamine, melamine salt, decabromodiphenylethane, bromotrimethylphenylindene oxide, pentabromochlorocyclohexane, 1,2-bis(tetrabromophthalimide)ethane, tetrachlorophthalic anhydride, and fluorosilicate.

[0021] Preferably, the flame retardant is a combination of tributyl phosphate and fluorosilicate, and the mass ratio is preferably (2-5):1.

[0022] Furthermore, the dispersant is any one of polyacrylamide, carboxymethyl cellulose, polyethylene wax, and polypropylene-polymer silicon dioxide copolymer wax.

[0023] Furthermore, the inorganic filler is selected from at least one of talc, kaolin, silicate, feldspar, mica, wollastonite, calcium carbonate, barium sulfate, silicon oxide, titanium oxide, aluminum hydroxide, boron nitride, aluminum nitride, and glass beads.

[0024] In a preferred embodiment, the inorganic filler is a combination of calcium carbonate and aluminum hydroxide; the mass ratio of the two is 1:(0.5-8), preferably 1:(0.5-3.5).

[0025] Furthermore, the average particle diameter of the calcium carbonate is 0.05-1.5 μm, preferably 0.05-0.8 μm.

[0026] Furthermore, the average particle diameter of the aluminum hydroxide is 2-100 nm, preferably 3-25 μm; more preferably 6-15 nm.

[0027] Furthermore, the fibers are continuous fibers or short fibers, preferably continuous fibers, with a fiber diameter of 1-30 μm.

[0028] Furthermore, the fiber is selected from at least one of glass fiber, carbon fiber, high molecular polyethylene fiber, boron fiber, aramid fiber, natural mineral whisker, basalt fiber, and metal fiber.

[0029] Furthermore, the fiber is selected from at least one of glass fiber, carbon fiber, aramid fiber, and basalt fiber.

[0030] In a preferred embodiment, the fibers are glass fibers and aramid fibers.

[0031] Furthermore, the fiber must be modified with a prepreg, wherein the prepreg is composed of a silane coupling agent, an imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group, and a solvent; the polar group includes but is not limited to at least one of -OH, -SH, -NH-, and -COOH. This application uses continuous fibers to enhance the longitudinal strength of the photovoltaic module frame, but these continuous fibers are not easily dispersed in the matrix resin, which significantly reduces the stress resistance of the composite material; this application uses a silane coupling agent and an alkyl imidazoline quaternary ammonium salt to modify the fiber surface, and utilizes the functional groups and long molecular chains of the silane coupling agent and the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group to improve the dispersibility of the continuous fiber and its binding force with the resin, thereby significantly enhancing the elastic modulus of the composite material.

[0032] Furthermore, the method for modifying the fiber with the pre-impregnation liquid is: placing the fiber in the pre-impregnation liquid at 60-85° C. for 30-60 seconds, and then drying it.

[0033] Furthermore, the silane coupling agent is selected from at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 1,2-bis(triethoxysilyl)ethane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane.

[0034] Furthermore, the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group is selected from at least one of dodecylcarboxymethylimidazoline quaternary ammonium salt, hexadecyl-3-(11-hydroxyundecyl)-2-methylimidazoline quaternary ammonium salt, heptadecyldihydroxyethylimidazoline quaternary ammonium salt, heptadecylhydroxyethylimidazoline quaternary ammonium salt, and octadecyldimethylhydroxyethylimidazoline quaternary ammonium salt.

[0035] In a preferred embodiment, the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group is dodecylcarboxymethylimidazoline quaternary ammonium salt.

[0036] The present invention unexpectedly discovered that when the mass ratio of the silane coupling agent and the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group in the prepreg is (1-2): (3-5), the mechanical strength of the composite material is most excellent. The inventors speculate that the reason is that when the fiber and the resin, two substances with different properties, are combined, the interfacial properties are poor, and the resistance to external impact is weak. In severe cases, undesirable phenomena such as fiber breakage or resin brittle cracking occur. However, the use of the silane coupling agent and the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group not only increases the compatibility of the fiber and the resin, but also changes the arrangement state of the inorganic filler in the system, causing more inorganic filler to be arranged at the interface between the fiber and the resin, improving the interfacial properties, and thus increasing the mechanical strength of the composite material. However, when the relative content of the silane coupling agent and the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group is too much or too little, this special filler arrangement state is changed, which in turn significantly weakens the strengthening effect.

[0037] Secondly, the present application also provides a method for preparing a fiber-reinforced composite photovoltaic module frame, specifically:

[0038] S1. Modification of fiber;

[0039] S2, mixing the components of the resin mixture and stirring them evenly;

[0040] S3. Arrange the modified fibers and immerse them in the above resin mixture; then press the mixed system into a mold, heat it to 130-150°C, stop heating, let it stand for 2-5 minutes, open the mold, take out the formed photovoltaic module frame, and let it cool naturally.

[0041] Beneficial effects

[0042] 1. This application optimizes the resin system. By optimizing the resin type and content, the system has excellent aging resistance and mechanical strength;

[0043] 2. This application uses a combination of different fibers and pre-impregnates the fibers, further defines the components and content of the pre-impregnation solution, and modifies the fiber surface. This not only improves the dispersion and compatibility of the fibers in the system, but also forms an interactive force with the resin, further increasing the strength and service life of the composite photovoltaic module frame.

[0044] 3. Compared with traditional aluminum alloy frames, the fiber-reinforced composite photovoltaic module frame of this application is lighter and less expensive, has excellent aging resistance and weather resistance, is not prone to adverse phenomena such as powdering and discoloration, and can meet the standard of 25 years of use. DETAILED DESCRIPTION

[0045] Example

[0046] Example 1

[0047] This embodiment provides a fiber-reinforced composite photovoltaic module frame. The raw materials of the photovoltaic module frame include, by total weight, 38% of a resin mixture and 62% of fiber. The components of the resin mixture include, by weight, 100 parts of a base resin, 3 parts of a curing agent, 2 parts of a lubricant, 10 parts of a flame retardant, 1.5 parts of a dispersant, and 20 parts of an inorganic filler.

[0048] The base resin is a polyurethane resin (BASF 1185A) and a melamine formaldehyde resin. The melamine formaldehyde resin has a number average molecular weight of 40,000 and a viscosity of 3,800 mPa·s at 25°C. The amount used is 50 wt% of the polyurethane resin and is purchased from Jining Huakai Resin. The curing agent is methyl ethyl ketone peroxide, the lubricant is calcium stearate, and the flame retardants are tributyl phosphate and zinc fluorosilicate in a mass ratio of 3.2:1. The dispersant is polyethylene wax (BASF A wax). The inorganic filler is calcium carbonate and aluminum hydroxide in a mass ratio of 1:2. The average particle diameter of the calcium carbonate is 0.3 μm and is purchased from Shanghai Jianghu Titanium Dioxide Chemical Products Co., Ltd. The average particle diameter of the aluminum hydroxide is 10 nm and is purchased from Xuancheng Jingrui New Materials Co., Ltd.

[0049] The fibers are glass fiber (diameter of 10 μm, Taishan Glass Fiber Co., Ltd.) and aramid fiber (diameter of 18 μm, Shandong Super Silk Technology Co., Ltd.), with a mass ratio of 1:1; the fibers must be modified by a pre-impregnation liquid, and the pre-impregnation liquid is composed of 16 wt% of γ-glycidyloxypropyltrimethoxysilane, 40 wt% of heptadecyl dihydroxyethyl imidazoline quaternary ammonium salt, and 44 wt% of ethanol.

[0050] The preparation method of the fiber-reinforced composite material photovoltaic module frame is as follows:

[0051] S1. Fiber modification: Place the fiber in the pre-impregnation solution at 75°C for 40 seconds, and then dry it;

[0052] S2, mixing the components of the resin mixture and stirring them evenly;

[0053] S3. Arrange the modified fibers and immerse them in the above resin mixture; then press the mixed system into a mold, heat it to 140°C, stop heating, let it stand for 3 minutes, open the mold, take out the formed photovoltaic module frame, and cool it naturally.

[0054] Example 2

[0055] This embodiment provides a fiber-reinforced composite photovoltaic module frame. The raw materials of the photovoltaic module frame include, by total weight, 45% of a resin mixture and 55% of fiber. The components of the resin mixture include, by weight, 80 parts of a base resin, 1 part of a curing agent, 3 parts of a lubricant, 5 parts of a flame retardant, 0.5 parts of a dispersant, and 12 parts of an inorganic filler.

[0056] The base resin is polyurethane resin (Bayer 3065D) and melamine formaldehyde resin. The melamine formaldehyde resin has a number average molecular weight of 60,000 and a viscosity of 5200 mPa·s. The amount used is 25 wt% of the polyurethane resin and is purchased from Jining Huakai Resin. The curing agent is methyl ethyl ketone peroxide, the lubricant is calcium stearate, and the flame retardant is tributyl phosphate and zinc fluorosilicate in a mass ratio of 2:1. The dispersant is polyethylene wax (BASF A wax). The inorganic filler is calcium carbonate and aluminum hydroxide in a mass ratio of 1:3.5. The average particle diameter of the calcium carbonate is 0.05μm, purchased from Shanghai Jianghu Titanium Dioxide Chemical Products Co., Ltd.; the average diameter of the aluminum hydroxide particles is 5nm, purchased from Xuancheng Jingrui New Materials Co., Ltd.; the fibers are glass fibers (diameter 15μm, Taishan Glass Fiber Co., Ltd.) and aramid fibers (diameter 18μm, Shandong Super Silk Technology Co., Ltd.), with a mass ratio of 1:1; the fibers must be modified by a pre-impregnation liquid, and the pre-impregnation liquid is composed of 20wt% of γ-glycidyloxypropyltrimethoxysilane, 30wt% of heptadecyl dihydroxyethyl imidazoline quaternary ammonium salt, and 50wt% of ethanol.

[0057] The preparation method of the fiber-reinforced composite material photovoltaic module frame is as follows:

[0058] S1. Fiber modification: Place the fiber in the pre-impregnation solution at 85°C for 30 seconds, and then dry it;

[0059] S2, mixing the components of the resin mixture and stirring them evenly;

[0060] S3. Arrange the modified fibers and immerse them in the above resin mixture; then press the mixed system into a mold, heat it to 130°C, stop heating, let it stand for 2 minutes, open the mold, take out the formed photovoltaic module frame, and cool it naturally.

[0061] Example 3

[0062] This embodiment provides a fiber-reinforced composite photovoltaic module frame. The raw materials of the photovoltaic module frame include, by total weight, 30% of a resin mixture and 70% of fiber. The components of the resin mixture include, by weight, 120 parts of a base resin, 4 parts of a curing agent, 3 parts of a lubricant, 15 parts of a flame retardant, 2 parts of a dispersant, and 30 parts of an inorganic filler.

[0063] The base resin is polyurethane resin (BASF 1185A) and melamine formaldehyde resin. The melamine formaldehyde resin has a number average molecular weight of 20,000 and a viscosity of 2500 mPa·s. The amount used is 60 wt% of the polyurethane resin and is purchased from Jining Huakai Resin. The curing agent is methyl ethyl ketone peroxide, the lubricant is calcium stearate, and the flame retardant is tributyl phosphate and zinc fluorosilicate in a mass ratio of 5:1. The dispersant is polyethylene wax (BASF A wax). The inorganic filler is calcium carbonate and aluminum hydroxide in a mass ratio of 1:1. The average particle diameter of the calcium carbonate is 0.2μm, purchased from Shanghai Jianghu Titanium Dioxide Chemical Products Co., Ltd.; the average diameter of the aluminum hydroxide particles is 15nm, purchased from Xuancheng Jingrui New Materials Co., Ltd.; the fibers are glass fiber (diameter 10μm, Taishan Glass Fiber Co., Ltd.) and aramid fiber (diameter 30μm, Shandong Super Silk Technology Co., Ltd.), with a mass ratio of 1:1; the fibers must be modified by a pre-impregnation liquid, and the pre-impregnation liquid is composed of 10wt% of γ-glycidyloxypropyltrimethoxysilane, 50wt% of heptadecyl dihydroxyethyl imidazoline quaternary ammonium salt, and 40wt% of ethanol.

[0064] The preparation method of the fiber-reinforced composite material photovoltaic module frame is as follows:

[0065] S1. Fiber modification: Place the fiber in the pre-impregnation solution at 60°C for 60 seconds, and then dry it;

[0066] S2, mixing the components of the resin mixture and stirring them evenly;

[0067] S3. Arrange the modified fibers and immerse them in the above resin mixture; then press the mixed system into a mold, heat it to 150°C, stop heating, let it stand for 5 minutes, open the mold, take out the formed photovoltaic module frame, and let it cool naturally.

[0068] Comparative Example 1

[0069] The method is basically the same as Example 1, except that the amount of the melamine formaldehyde resin used is 70 wt % of the polyurethane resin.

[0070] Comparative Example 2

[0071] The method is basically the same as Example 1, except that the melamine formaldehyde resin has a number average molecular weight of 100,000 and a viscosity of 9500 mPa·s, and is purchased from Jining Huakai Resin.

[0072] Comparative Example 3

[0073] The method is basically the same as Example 1, except that the pre-dip solution is composed of 16 wt % of γ-glycidyloxypropyltrimethoxysilane, 20 wt % of heptadecyl dihydroxyethyl imidazoline quaternary ammonium salt, and 64 wt % of ethanol.

[0074] Comparative Example 4

[0075] The method is basically the same as that of Example 1, except that the pre-dip solution is composed of 16 wt % of γ-glycidyloxypropyltrimethoxysilane, 40 wt % of octadecyltrimethylammonium bromide, and 44 wt % of ethanol.

[0076] Comparative Example 5

[0077] The method is basically the same as Example 1, except that the average particle diameter of the aluminum hydroxide is 0.5 μm and is purchased from Shandong Zhongrun Haihua Chemical Technology Co., Ltd.

[0078] Performance testing method:

[0079] The test pieces of the above embodiments were tested for tensile strength, flexural strength, and aging resistance (wet and hot test, 14 cycles) according to GBT 1447-2005, GBT 1449-2005, and GBT 2573-2008 standards.

[0080] Performance test results:

[0081] The test results are shown in Table 1.

[0082] Table 1

[0083]

[0084]

Claims

1. A fiber-reinforced composite photovoltaic module frame, characterized in that: The raw materials of the photovoltaic module frame include, by total weight: 30-45% resin mixture and 55-70% fiber; The components of the resin mixture include: by weight, 80-120 parts of base resin, 1-4 parts of curing agent, 1-3 parts of lubricant, 5-15 parts of flame retardant, 0.5-3 parts of dispersant, and 5-35 parts of inorganic filler; The base resin includes a polyurethane resin; The base resin further comprises melamine formaldehyde resin, the number average molecular weight of the melamine formaldehyde resin is 20,000-60,000, and the viscosity at 25° C. is 2000-6000 mPa·s; The amount of the melamine formaldehyde resin is 25-60wt% of the polyurethane resin; The fiber must be modified by a pre-impregnation solution, which consists of a silane coupling agent, an imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group, and a solvent; The imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group is selected from at least one of dodecylcarboxymethylimidazoline quaternary ammonium salt, hexadecyl-3-(11-hydroxyundecyl)-2-methylimidazoline quaternary ammonium salt, heptadecyldihydroxyethylimidazoline quaternary ammonium salt, heptadecylhydroxyethylimidazoline quaternary ammonium salt, and octadecyldimethylhydroxyethylimidazoline quaternary ammonium salt; The mass ratio of the silane coupling agent to the imidazoline ammonium salt having at least one C4-C18 chain and at least one polar group is (1-2): (3-5); The inorganic fillers are calcium carbonate and aluminum hydroxide, and the average particle diameter of the aluminum hydroxide is 2-100 nm.

2. The photovoltaic module frame according to claim 1, characterized in that: The fiber is selected from at least one of glass fiber, carbon fiber, high molecular polyethylene fiber, boron fiber, aramid fiber, natural mineral whisker, basalt fiber, and metal fiber.

3. The method for preparing a photovoltaic module frame according to any one of claims 1 to 2, characterized in that: The preparation method is: S1. Modification of fiber; S2, mixing the components of the resin mixture and stirring them evenly; S3. Arrange the modified fibers and immerse them in the above resin mixture; then press the mixed system into a mold, heat it to 130-150°C, stop heating, let it stand for 2-5 minutes, open the mold, take out the formed photovoltaic module frame, and let it cool naturally.

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