A composite photovoltaic front panel and its preparation method and application

Abstract

The present invention relates to the technical field of photovoltaic front panels, and discloses a composite photovoltaic front panel and a preparation method and application thereof. The composite photovoltaic front panel includes a transparent substrate (transparent polyester film material), a resin bonding material layer and a reinforced resin material layer coated with glass fiber cloth; the resin bonding material includes a polyhydroxy polyester resin, a curing agent, an ultraviolet absorber, an antioxidant, a leveling agent and other additives; the molar ratio of the hydroxyl group of the polyester resin to the isocyanate group of its curing agent is 1:1-1.2; the reinforced resin material includes an epoxy resin, a curing agent, an ultraviolet absorber, an antioxidant and other additives; the molar ratio of the epoxy group of the epoxy resin to the acid anhydride of the curing agent is 1:0.80-0.9. The composite photovoltaic front panel has excellent light transmittance, mechanical strength and bending strength, and can also prevent the interlayer delamination phenomenon of the initial and long-term aging. The light transmittance and interlayer peeling strength after PCT48h aging are good, and it is suitable for application in flexible photovoltaic modules.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic front panels, and in particular to a composite photovoltaic front panel and a preparation method and application thereof. Background Art

[0002] In recent years, with the rapid development of photovoltaic modules, lightweight flexible photovoltaic modules have gradually attracted people's attention. Compared with traditional rigid photovoltaic modules, the weight of flexible photovoltaic modules can be reduced by about 80%; in addition, flexible photovoltaic modules can be bent and stacked without the need for special brackets. They can be widely used in construction, mobile cars, foldable batteries and other fields, and have great development potential.

[0003] The photovoltaic glass used in traditional rigid photovoltaic modules, although its flexibility is relatively poor and its weight is also high, its mechanical strength is far superior to existing transparent flexible materials such as PET, PC, and PMMA. In order to increase the mechanical strength of existing transparent flexible materials, a glass fiber reinforcement layer is usually compounded. However, due to the hard texture, poor mechanical strength and small number of surface functional groups of existing commonly used transparent flexible materials (such as PET substrates, PC substrates, PMMA substrates, etc.), the existing commonly used transparent flexible materials (such as PET substrates, PC substrates, PMMA substrates, etc.) are relatively hard, have poor mechanical strength and a small number of surface functional groups. Therefore, as shown in Publication No. CN118231503A: When the thermosetting resin material layer coated with glass fiber cloth is directly used for composite reinforcement, although heating can cure the thermosetting resin material of the thermosetting resin material layer (i.e., the reinforcement layer) coated with glass fiber cloth, due to the shrinkage of the thermosetting resin during the curing process and the small number of reactive functional groups on the surface of the PET substrate, it will be difficult to form a long-term effective bond between the PET substrate and the thermosetting resin material layer coated with glass fiber cloth, which will cause the interlayer peeling strength of the photovoltaic panel to decrease significantly after PCT48h aging.

[0004] Based on this, some existing solutions are: obtaining a glass fiber reinforced PET substrate by means of film bonding, or adding glass fiber into the molten PET during the PET melt extrusion process. Although these methods have a certain improvement on the bonding effect, they will cause the preparation process of the photovoltaic front panel to be extremely complicated, the preparation conditions are strict, and the cost is very high. It will also lead to a decrease in the transparency of the photovoltaic front panel, affecting the absorption of visible light by the photovoltaic module, which is not conducive to the improvement of the photoelectric conversion efficiency of the photovoltaic module.

[0005] For example, publication number CN110620161A discloses a lightweight flexible photovoltaic module, which includes a PVF film layer, a composite glass fiber layer, a battery string and an FFC double-sided fluorine-containing backplane from top to bottom. In order to solve the bonding problem, EVA film is used for bonding between the PVF film layer and the composite glass fiber layer, between the composite glass fiber layer and the battery string, and between the battery string and the FFC double-sided fluorine-containing backplane. Although this method adds a composite glass fiber layer to the front surface of the battery string, which improves the mechanical strength of the photovoltaic front panel; however, the use of too much EVA film will make the photovoltaic module costly, and puts forward high requirements on the production process and the transparency of the EVA film.

[0006] The method of adding glass fiber (or glass fiber cloth) during the preparation of the commonly used transparent flexible material by melt extrusion has more stringent requirements on processing conditions. For example, publication number CN116656108A discloses a thermoplastic composite material for photovoltaic front panels. After continuous glass fibers coated with thermoplastic resin (PC, PMMA, PET, PP, etc.) emulsion are vibrated and dispersed, they are impregnated with thermoplastic resin melt in the impregnation mold cavity, and after the subsequent flattening and cooling processes, a transparent thin strip material is formed. Although this method avoids the problem of interfacial bonding between the glass fiber layer and the thermoplastic resin; but the processing conditions are very harsh, and the processing temperature is as high as 230-260 ° C; and, even at high temperatures, it is difficult for the thermoplastic resin melt to completely infiltrate the glass fiber, which has an adverse effect on the transparency of the final photovoltaic front panel product, and the mechanical reinforcement effect of the glass fiber is also very limited. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a composite photovoltaic front panel and a preparation method and application thereof.

[0008] Based on this, the present invention discloses a composite photovoltaic front plate, comprising a transparent substrate, a resin adhesive material layer sequentially coated on the surface of the transparent substrate, and a reinforced resin material layer coated with a glass fiber cloth;

[0009] The transparent substrate is a transparent polyester film material;

[0010] The resin adhesive material used in the resin adhesive material layer includes the following raw materials in weight ratio: 100 parts of polyhydroxy polyester resin, 30-50 parts of isocyanate curing agent, 1-2 parts of ultraviolet absorber, 1-2 parts of antioxidant, 0.3-0.5 parts of leveling agent and 2-10 parts of other auxiliary agents; the molar ratio of hydroxyl group in the polyester resin to isocyanate group in the isocyanate curing agent is 1:1-1.2;

[0011] The reinforcing resin material used for the reinforcing resin material layer of the glass fiber cloth coating includes raw materials in the following weight ratios: 100 parts of epoxy resin, 70-105 parts of anhydride type curing agent, 1-2 parts of ultraviolet absorber, 1-2 parts of antioxidant and 2-5 parts of other auxiliary agents; the molar ratio of the epoxy group in the epoxy resin to the anhydride in the anhydride type curing agent is 1:0.80-0.9.

[0012] In the present invention, since the composite photovoltaic front panel is improved on the basis of combining traditional transparent flexible materials (such as PET substrate, PC substrate, PMMA substrate, etc.), it can also meet the various requirements of the final photovoltaic module for transparent flexible materials under long-term outdoor use (such as weather resistance, UV resistance, yellowing, etc.).

[0013] Thanks to the use of epoxy resin in the reinforced resin material of the present invention, the finished composite photovoltaic front panel product not only has advantages in mechanical strength, but also has great advantages in heat resistance, cost and flexibility in formula design.

[0014] Preferably, the polyester resin is polyester polyol and / or polyether polyol; when the polyester resin is polyester polyol, the hydroxyl value of the polyester polyol is 50-120 mgKOH / g and the viscosity is 200-4000 mPa•s;

[0015] The isocyanate curing agent is one or more of diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate trimer, and dicyclohexylmethane diisocyanate.

[0016] Preferably, the molar ratio of the hydroxyl group in the polyester resin to the isocyanate group in the isocyanate curing agent is 1:1.1;

[0017] The resin bonding material comprises the following raw materials in the following weight ratios: 100 parts of polyhydroxy polyester resin, 36 parts of isocyanate curing agent, 1 part of ultraviolet absorber, 1 part of antioxidant, 0.3 part of leveling agent and 4 parts of other auxiliary agents.

[0018] Preferably, the epoxy resin is a glycidyl ether epoxy resin and / or a glycidyl ester epoxy resin, and its epoxy value is 0.7-1.1;

[0019] The anhydride type curing agent is hexahydrophthalic anhydride.

[0020] Further preferably, the epoxy resin is a glycidyl ether epoxy resin, and its epoxy value is 0.75; the molar ratio of the epoxy group in the epoxy resin to the acid anhydride in the acid anhydride curing agent is preferably 1:0.85;

[0021] The reinforced resin material comprises raw materials in the following weight ratios: 100 parts of epoxy resin, 98 parts of anhydride curing agent, 1 part of ultraviolet absorber, 1 part of antioxidant and 2 parts of other auxiliary agents.

[0022] Further preferably, the other additives in the resin adhesive material include a diluent and an anti-hydrolysis agent, and the diluent is a reactive diluent containing an epoxy group; the other additive in the reinforced resin material is an anti-hydrolysis agent;

[0023] The ultraviolet absorber is a triazine type ultraviolet absorber; the antioxidant is a hindered amine type antioxidant or a hindered phenol type antioxidant; and the leveling agent is an organosilicon type leveling agent (such as a polyester modified organosilicon type leveling agent).

[0024] Further preferably, the weight per square meter of the glass fiber cloth is in the range of 50-350g;

[0025] The thickness of the resin bonding material layer is ≤30 microns;

[0026] The transparent substrate is a film formed by mixing and extruding one or more of PC, PMMA, PET and PBT, and the thickness of the transparent substrate is ≤300 microns.

[0027] The present invention also discloses a method for preparing a composite photovoltaic front panel, comprising the following preparation steps:

[0028] S1. Cut the transparent substrate, glass fiber cloth and release film into appropriate sizes respectively;

[0029] S2 weigh the raw materials according to the weight ratio of the formula amount to configure the resin adhesive material and the reinforcing resin material;

[0030] S3. The transparent substrate is corona treated, and then the resin adhesive material is evenly applied to the surface of the transparent substrate, heated and cured to form a resin adhesive material layer, removed and cooled to room temperature;

[0031] S4. Place glass fiber cloth on the surface of the resin adhesive material layer, apply the reinforcing resin material, let it stand, and after the glass fiber cloth is completely soaked, cover it with a release film, squeeze out excess reinforcing resin material, flatten it, and heat and cure it to form a reinforcing resin material layer covering the glass fiber cloth.

[0032] Preferably, in step S3, the curing temperature of the resin adhesive material is 130-160° C. and the curing time is 1-10 minutes;

[0033] In step S4, the reinforcing resin material is cured at a temperature of 140-160° C. and for a time of 10-20 minutes.

[0034] The present invention also discloses an application of a composite photovoltaic front plate, and the composite photovoltaic front plate is used in a flexible photovoltaic module instead of photovoltaic glass.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] The composite photovoltaic front panel of the present invention introduces a resin adhesive material layer (that is, a polyester resin-isocyanate curing agent system with excellent adhesion, the molar ratio of hydroxyl groups in the polyester resin to isocyanate groups in the isocyanate curing agent is 1:1.0-1.2, preferably 1:1.1) to achieve a better long-term bonding effect between the resin adhesive material layer and a transparent substrate (such as a PET substrate); at the same time, relying on the multiple reactive functional groups (including isocyanate groups, hydroxyl groups, etc.) contained on the surface of the resin adhesive material layer after curing and the relatively large number of epoxy groups in the epoxy resin-acid anhydride curing agent system (the molar ratio of the number of epoxy groups in the epoxy resin to the acid anhydride in the acid anhydride curing agent is 1:0.80-0.9) of the reinforcing resin material layer coated with the glass fiber cloth, the resin adhesive material layer can also form a better long-term bonding effect with the subsequent reinforcing resin material layer coated with the glass fiber cloth. Moreover, the resin adhesive material layer also has a buffering effect, so that the shrinkage of the epoxy resin in the reinforcing resin material layer that subsequently coats the glass fiber cloth during the curing process greatly reduces the impact on the transparent substrate.

[0037] The present invention adopts a special structural design and is matched with specific resin adhesive materials and reinforced resin materials. The composite photovoltaic front panel can have high light transmittance, high mechanical strength and high bending strength, while effectively preventing interlayer delamination during the initial and long-term aging process. The composite photovoltaic front panel has high 400-1000nm light transmittance and interlayer peeling strength after PCT48h aging.

[0038] In addition, the preparation method of the composite photovoltaic front panel of the present invention does not require a precise melt extrusion (or complex lamination) process to achieve a firm bond between the transparent substrate and the reinforced resin material layer coated with the glass fiber cloth. The curing temperature is low, which can greatly reduce the difficulty of the production process and the requirements for equipment, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the cross-sectional structure of a composite photovoltaic front panel of Example 1-7.

[0040] Figure 2 Schematic diagram of the cross-sectional structure of a composite photovoltaic front panel of Comparative Example 1-2.

[0041] Description of the accompanying drawings: transparent substrate 1; resin adhesive material layer 2; reinforcing resin material layer 3 coated with glass fiber cloth. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

[0043] A composite photovoltaic front panel of this embodiment, see Figure 1 It comprises a transparent substrate 1, a resin adhesive material layer 2 and a reinforcing resin material layer 3 coated with glass fiber cloth, which are stacked in sequence.

[0044] The transparent substrate 1 is a film of PET material and has a thickness of 280 micrometers.

[0045] The resin adhesive material layer 2 is formed by uniformly coating the polyester resin, curing agent, ultraviolet absorber, antioxidant, leveling agent and other additives on the surface of the transparent substrate 1 and curing the mixture by heating. The thickness of the resin adhesive material layer 2 is 26 microns.

[0046] Specifically, the resin adhesive material used in the resin adhesive material layer 2 includes the following raw materials in parts by weight:

[0047] Polyester resin 100 parts

[0048] 36 parts of curing agent

[0049] 1 part UV absorber

[0050] 1 part antioxidant

[0051] 0.3 parts of leveling agent

[0052] 4 parts of other additives.

[0053] The polyester resin in the resin bonding material is polyester polyol. The viscosity of the polyester resin is 1000 mPa•s, and the hydroxyl (-OH) value of the polyester polyol is 100 mgKOH / g.

[0054] The curing agent in the resin adhesive material is hexamethylene diisocyanate trimer, and the molar ratio of the hydroxyl group in the polyester polyol to the isocyanate group in the curing agent is 1:1.1.

[0055] The ultraviolet absorber in the resin adhesive material is a triazine type ultraviolet absorber, the antioxidant is a hindered phenol type antioxidant, and the leveling agent is a polyester modified silicone type leveling agent.

[0056] Other additives in the resin adhesive material include diluents and anti-hydrolysis agents. The diluents are glycidyl ether type diluents and glycidyl ester type diluents. The anti-hydrolysis agent is polycarbodiimide.

[0057] The reinforced resin material layer 3 coated with glass fiber cloth is prepared by uniformly mixing epoxy resin, curing agent, ultraviolet absorber, antioxidant and other additives, coating the mixture on the surface of the resin adhesive material layer 2 with glass fiber cloth, and then heating and curing the mixture.

[0058] Specifically, the glass fiber cloth is made by weaving glass fiber materials; the glass fiber cloth is made by plain weaving of glass fiber materials. In order to take into account both light weight and mechanical strength, in this embodiment, the weight of each square meter of the glass fiber cloth is 300g.

[0059] Specifically, the reinforced resin material used in the reinforced resin material layer 3 covering the glass fiber cloth includes the following raw materials by weight:

[0060] Epoxy resin 100 parts

[0061] Curing agent 98 parts

[0062] 1 part UV absorber

[0063] 1 part antioxidant

[0064] 2 parts of other additives.

[0065] The epoxy resin in the reinforced resin material is a glycidyl ether type epoxy resin, and its epoxy value is 0.75.

[0066] The curing agent in the reinforced resin material is hexahydrophthalic anhydride, and the molar ratio of the epoxy group in the epoxy resin to the anhydride in the curing agent is 1:0.85.

[0067] The ultraviolet absorber in the reinforced resin material is a triazine type ultraviolet absorber, the antioxidant is a hindered phenol type antioxidant, and the other auxiliary agent is an anti-hydrolysis agent.

[0068] A method for preparing a composite photovoltaic front panel of this embodiment includes the following preparation steps:

[0069] S1. Cut the transparent substrate 1, glass fiber cloth and release film into 600 mm×600 mm sizes respectively.

[0070] S2. Weigh each raw material according to the weight ratio of the formula to respectively configure the resin adhesive material and the reinforcing resin material. The resin adhesive material and the reinforcing resin material are respectively stirred evenly at a stirring speed of 1000r / min and a stirring time of 4min.

[0071] S3. The transparent substrate 1 is subjected to corona treatment with a corona power of 5000 W, and then the prepared resin adhesive material is evenly applied on the surface of the transparent substrate 1, and heated at 150°C for 4 minutes to solidify to form a resin adhesive material layer 2. The substrate is taken out and cooled to room temperature. The thickness of the cured resin adhesive material layer 2 is measured to be 22 μm.

[0072] S4. Place the cut glass fiber cloth on the surface of the cured resin adhesive material layer 2, apply the reinforcing resin material, let it stand, and after the glass fiber cloth is completely soaked, cover it with a release film, squeeze out the excess reinforcing resin material, flatten it, heat it at 150°C for 15 minutes to solidify it to form a reinforced resin material layer 3 coated with the glass fiber cloth, cool it to room temperature, remove the release film, and then obtain the composite photovoltaic front panel of this embodiment.

[0073] In summary, the composite photovoltaic front panel of this embodiment combines the existing transparent flexible material, the resin adhesive material layer 2 and the reinforced resin material layer 3 coated with glass fiber cloth, and solves the problem of interlayer stratification through simple coating and curing. The preparation process is very simple and the preparation cost is low, and the comprehensive performance of the composite photovoltaic front panel for long-term outdoor use is guaranteed.

[0074] The composite photovoltaic front panel of this embodiment can replace the front panel glass and the back panel glass to be applied in a flexible photovoltaic module.

[0075] Embodiment 2-7

[0076] A composite photovoltaic front panel and its preparation method and application in Examples 2-7 are all referred to in Example 1, and the difference between them and Example 1 is that in a composite photovoltaic front panel in Example 2-7, the ratio of isocyanate in the curing agent in the resin adhesive material, or the content of the diluent, or the ratio of the acid anhydride in the curing agent in the reinforced resin material layer 3 coated with glass fiber cloth is changed. In parts by weight, the raw material composition of the resin adhesive material and the raw material composition of the reinforced resin material in a composite photovoltaic front panel in Example 2-7 are shown in Tables 1 and 2 below, respectively.

[0077]

[0078]

[0079] Comparative Examples 1-3

[0080] A composite photovoltaic front sheet and its preparation method and application in Comparative Examples 1-3 are all based on Example 1, and the difference between them and Example 1 is that: in a composite photovoltaic front sheet in Comparative Examples 1-2, there is no resin adhesive material layer 2 (such as Figure 2 As shown); and the proportion of the curing agent in the reinforced resin material of Comparative Example 2 has changed; the rest remains unchanged.

[0081] In a composite photovoltaic front sheet of Comparative Example 3, no additives such as ultraviolet absorbers, antioxidants, leveling agents, diluents and anti-hydrolysis agents are added to the resin adhesive material. In a composite photovoltaic front sheet of Comparative Examples 1-3, the raw material composition of the resin adhesive material and the raw material composition of the reinforcing resin material are shown in Table 3 and Table 4, respectively, by weight.

[0082]

[0083]

[0084] Performance Testing

[0085] The following performance tests were conducted on the composite photovoltaic front sheets prepared in Examples 1-7 and Comparative Examples 1-3: bending strength, initial light transmittance, light transmittance after PCT 48h aging, haze after PCT 48h aging, and interlayer peeling strength between the transparent substrate 1 and the reinforced resin material layer 3 coated with glass fiber cloth after PCT 48h aging. The test data are shown in Table 5 below:

[0086]

[0087] As can be seen from Tables 1-4, in Examples 1-3, the proportion of isocyanate curing agent in the resin adhesive material is changed; in Examples 1, 4, and 5, the proportion of anhydride curing agent in the reinforced resin material coated with glass fiber cloth is changed; in Examples 1, 6, and 7, the proportion of diluent in the resin adhesive material is changed. Comparative Examples 1 and 2 do not have a resin adhesive material layer 2, and the proportion of curing agent in the reinforced resin material of Comparative Example 2 is changed; in Comparative Example 3, no additives are added to the resin adhesive material.

[0088] According to the data in Table 5, we can know that:

[0089] It can be seen from the data of Comparative Examples 1 and 2 that: in the absence of the resin adhesive material layer 2, the transparent substrate 1 and the reinforced resin material layer 3 coated with the glass fiber cloth are delaminated during the initial mechanical test (such as bending strength), and the interlayer interface is completely separated after PCT 48h aging. At the same time, the haze after PCT 48h aging is significantly reduced. This is because water vapor completely enters the interlayer interface during the aging process.

[0090] It can be seen from the data of Comparative Example 3 that when no additive is added to the resin adhesive material, the interlayer peeling strength of the composite photovoltaic front panel PCT after 48h aging is obviously at a poor level.

[0091] From the data of Examples 1-3, it can be seen that the change in the proportion of isocyanate curing agent in the resin adhesive material has a great influence on the performance of the final composite photovoltaic front panel product. Specifically, when the proportion of isocyanate curing agent is low (such as Example 2), the haze of the composite photovoltaic front panel after PCT48h aging is relatively larger, and the interlayer peeling strength after PCT48h aging is significantly reduced; and when the proportion of isocyanate curing agent is high (such as Example 3), the 400-1100nm light transmittance and interlayer peeling strength of the composite photovoltaic front panel after PCT48h aging are slightly reduced. As shown in Example 1, in the resin adhesive material, when the molar ratio of the hydroxyl group in the polyester resin to the isocyanate group in the curing agent is 1:1.1, the comprehensive performance of the composite photovoltaic front panel is better.

[0092] From the data comparison of Example 1, Example 4 and Example 5, it can be seen that the proportion of curing agent (such as anhydride curing agent) used for epoxy resin in the reinforced resin material for coating glass fiber cloth has a great influence on the performance of the final reinforced composite photovoltaic front panel. Specifically, less anhydride curing agent (such as Example 4) or more anhydride curing agent (such as Example 5) will make the bending strength of the finished composite photovoltaic front panel lower, but the addition of more anhydride curing agent can make the haze of the finished composite photovoltaic front panel lower after PCT48h aging, and the interlayer peeling strength after PCT48h aging remains at a high level.

[0093] From the data comparison of Example 1, Example 6 and Example 7, it can be seen that: in the resin adhesive material, when the proportion of the diluent increases (such as Example 7), the interlayer peeling strength of the composite photovoltaic front panel product after PCT48h aging is maintained at a high level, which may be attributed to the use of a reactive diluent containing an epoxy group in Example 7, which can strengthen the bonding between the resin adhesive material layer 2 and the reinforced resin material layer 3 coated with glass fiber cloth; however, with the increase of the diluent, the haze of the composite photovoltaic front panel product after PCT48h aging increases, and the 400-1100nm light transmittance after PCT48h aging decreases, so the amount of diluent added to the resin adhesive material should not be too much.

[0094] In summary, the preparation process of the composite photovoltaic front panel of the present invention does not require the heating lamination process shown in CN118231503A. By coating and adding the cured resin adhesive material layer 2, the bonding strength between the transparent substrate 1 and the reinforced resin material layer 3 coated with the glass fiber cloth can be greatly improved without affecting the production process of combining the original transparent substrate 1 and the reinforced resin material layer 3 coated with the glass fiber cloth, so that the transparent substrate 1 and the reinforced resin material layer 3 coated with the glass fiber cloth can achieve long-term effective bonding, so that the prepared composite photovoltaic front panel can fully meet various requirements for long-term outdoor use (such as interlayer peeling strength after PCT48h aging, haze after PCT48h aging, light transmittance after PCT48h aging, etc.). Therefore, the present invention is not only simple in process, easy to operate, low in cost, and good in mechanical strength and bending strength, but also can overcome the defects of the existing enhanced photovoltaic front panel such as insufficient light transmittance (such as after initial PCT48h aging), easy stratification between layers, and insufficient heat resistance of the finished product.

[0095] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0096] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A composite photovoltaic front panel, It is characterized in that It includes a transparent substrate, a resin bonding material layer sequentially coated on the surface of the transparent substrate, and a reinforcing resin material layer coated with a glass fiber cloth; The transparent substrate is a transparent polyester film material; The resin adhesive material used in the resin adhesive material layer includes the following raw materials in weight ratio: 100 parts of polyhydroxy polyester resin, 30-50 parts of isocyanate curing agent, 1-2 parts of ultraviolet absorber, 1-2 parts of antioxidant, 0.3-0.5 parts of leveling agent and 2-10 parts of other auxiliary agents; the molar ratio of hydroxyl group in the polyester resin to isocyanate group in the isocyanate curing agent is 1:1-1.2; The reinforcing resin material used for the reinforcing resin material layer of the glass fiber cloth coating includes raw materials in the following weight ratios: 100 parts of epoxy resin, 70-105 parts of anhydride type curing agent, 1-2 parts of ultraviolet absorber, 1-2 parts of antioxidant and 2-5 parts of other auxiliary agents; the molar ratio of the epoxy group in the epoxy resin to the anhydride in the anhydride type curing agent is 1:0.80-0.

9.

2. A composite photovoltaic front panel according to claim 1, It is characterized in that The polyester resin is polyester polyol and / or polyether polyol; when the polyester resin is polyester polyol, the hydroxyl value of the polyester polyol is 50-120 mgKOH / g and the viscosity is 200-4000 mPa•s; The isocyanate curing agent is one or more of diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate trimer, and dicyclohexylmethane diisocyanate.

3. A composite photovoltaic front panel according to claim 1, It is characterized in that The molar ratio of the hydroxyl group in the polyester resin to the isocyanate group in the isocyanate curing agent is 1:1.1; The resin bonding material comprises the following raw materials in the following weight ratios: 100 parts of polyhydroxy polyester resin, 36 parts of isocyanate curing agent, 1 part of ultraviolet absorber, 1 part of antioxidant, 0.3 part of leveling agent and 4 parts of other auxiliary agents.

4. A composite photovoltaic front panel according to claim 1, It is characterized in that The epoxy resin is a glycidyl ether epoxy resin and / or a glycidyl ester epoxy resin, and its epoxy value is 0.7-1.1; The anhydride type curing agent is hexahydrophthalic anhydride.

5. A composite photovoltaic front panel according to claim 4, It is characterized in that The epoxy resin is a glycidyl ether epoxy resin, and its epoxy value is 0.75; the molar ratio of the epoxy group in the epoxy resin to the acid anhydride in the acid anhydride curing agent is 1:0.85; The reinforced resin material comprises raw materials in the following weight ratios: 100 parts of epoxy resin, 98 parts of anhydride curing agent, 1 part of ultraviolet absorber, 1 part of antioxidant and 2 parts of other auxiliary agents.

6. A composite photovoltaic front panel according to claim 1, It is characterized in that The other additives in the resin adhesive material include a diluent and an anti-hydrolysis agent, and the diluent is a reactive diluent containing an epoxy group; the other additive in the reinforced resin material is an anti-hydrolysis agent; The ultraviolet absorber is a triazine type ultraviolet absorber; the antioxidant is a hindered amine type antioxidant or a hindered phenol type antioxidant; and the leveling agent is an organic silicon type leveling agent.

7. The composite photovoltaic front panel according to claim 1, It is characterized in that The weight of the glass fiber cloth is in the range of 50-350g per square meter; The thickness of the resin bonding material layer is ≤30 microns; The transparent substrate is a film formed by mixing and extruding one or more of PC, PMMA, PET and PBT, and the thickness of the transparent substrate is ≤300 microns.

8. A method for preparing a composite photovoltaic front sheet according to any one of claims 1 to 7, It is characterized in that The method comprises the following preparation steps: S1. Cut the transparent substrate, glass fiber cloth and release film into appropriate sizes respectively; S2 weigh the raw materials according to the weight ratio of the formula amount to configure the resin adhesive material and the reinforcing resin material; S3. The transparent substrate is corona treated, and then the resin adhesive material is evenly applied to the surface of the transparent substrate, heated and cured to form a resin adhesive material layer, removed and cooled to room temperature; S4. Place glass fiber cloth on the surface of the resin adhesive material layer, apply the reinforcing resin material, let it stand, and after the glass fiber cloth is completely soaked, cover it with a release film, squeeze out excess reinforcing resin material, flatten it, and heat and cure it to form a reinforcing resin material layer covering the glass fiber cloth.

9. A method for preparing a composite photovoltaic front sheet according to claim 8, It is characterized in that In step S3, the resin adhesive material is cured at a temperature of 130-160° C. and for a time of 1-10 minutes; In step S4, the reinforcing resin material is cured at a temperature of 140-160° C. and for a time of 10-20 minutes.

10. Application of a composite photovoltaic front sheet according to any one of claims 1 to 7, It is characterized in that The composite photovoltaic front plate is used in flexible photovoltaic modules instead of photovoltaic glass.

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