CN119922994A - Photovoltaic back sheet and preparation method thereof, photovoltaic module - Google Patents

Abstract

The application relates to the technical field of solar cells, and mainly provides a photovoltaic backboard, a preparation method thereof and a photovoltaic module. The photovoltaic backboard comprises a composite fiber layer and a matrix layer which are sequentially stacked, wherein the composite fiber layer comprises a resin matrix, and continuous fibers and short fibers which are dispersed in the resin matrix. The photovoltaic backboard in the technical scheme of the application has light weight and good mechanical property, wear resistance, chemical stability and environmental aging resistance.

Description

Photovoltaic backboard, preparation method thereof and photovoltaic module

Technical Field

The application relates to the technical field of solar cells, in particular to a photovoltaic backboard, a preparation method thereof and a photovoltaic module.

Background

The photovoltaic backboard is an important component of the photovoltaic module and is positioned on the back of the photovoltaic module, so that the photovoltaic cell piece is protected and supported. The primary function of the photovoltaic back-sheet is to isolate the inside and outside environment of the module, ensure electrical insulation, enable the photovoltaic module to operate outdoors for a long time, and therefore, the performance (e.g., light and heavy, strength, and stability) of the photovoltaic back-sheet directly affects the performance and service life of the photovoltaic module.

In the prior art, some photovoltaic light components adopt a transparent backboard or a high-transparency fluorine film as a packaging material, so that the strength is low, and the requirement of the impact resistance (hail resistance) of the photovoltaic components is difficult to meet. Some photovoltaic light components adopt the structure of a substrate layer and a honeycomb core layer to replace the design of a backboard and an aluminum frame, and the connection compounding between the substrate layer and the honeycomb core layer is realized by using an adhesive layer or an adhesive film layer, however, the compound structure can cause the problems of bubbling, degumming, deformation peristaltic movement and the like in the subsequent lamination when being applied to the photovoltaic component, and the photovoltaic component has lower strength and poor support.

It should be noted that the foregoing is not necessarily prior art, and is not intended to limit the scope of the present application.

Disclosure of Invention

The application provides a photovoltaic backboard, a preparation method thereof and a photovoltaic module, which are used for solving or relieving the technical problems. The photovoltaic backboard in the technical scheme of the application has light weight and good mechanical property, wear resistance, chemical stability and environmental aging resistance.

In a first aspect, the embodiment of the application provides a photovoltaic backboard, which comprises a composite fiber layer and a matrix layer which are sequentially laminated;

Wherein the composite fiber layer comprises a resin matrix, and continuous fibers and short fibers dispersed in the resin matrix.

Optionally, the continuous fiber comprises one or more of glass fiber, carbon fiber, aramid fiber, alumina fiber and polyester fiber.

Optionally, the length of the continuous fiber is 100mm or more.

Optionally, the short fibers comprise one or two of glass fibers and carbon fibers, and the length of the short fibers is 0.1-1mm.

Optionally, the resin matrix forming resin comprises a first thermosetting resin or a first thermoplastic resin.

Optionally, the first thermoplastic resin includes one or more of polypropylene resin (PP), polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polyethylene resin (PE), and polyamide resin (PA).

Optionally, in the composite fiber layer, the mass ratio of the continuous fibers, the short fibers and the resin matrix forming resin is (1.5-3): 1-1.5): 1.

Optionally, the matrix layer forming resin includes a second thermosetting resin or a second thermoplastic resin.

Optionally, the second thermoplastic resin includes one or more of polypropylene resin (PP), polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polyethylene resin (PE), and polyamide resin (PA).

Optionally, the photovoltaic backsheet further comprises a weatherable layer on a side of the composite fiber layer remote from the substrate layer, and/or

The photovoltaic backboard further comprises an adhesive layer, and the adhesive layer is located on one side, far away from the composite fiber layer, of the substrate layer.

Optionally, the weathering layer is cured from a first fluorine-containing coating comprising a fluorocarbon resin and a first curing agent, and/or

The adhesive layer is formed by curing a second fluorine-containing coating, and the second fluorine-containing coating comprises fluorocarbon resin and a second curing agent.

Optionally, the composite fiber layer has a thickness of 30-100 μm, and/or

The thickness of the substrate layer is 275-315 μm, and/or

The thickness of the weather-resistant layer is 25-105 μm, and/or

The thickness of the adhesive layer is 5-40 mu m.

In a second aspect, an embodiment of the present application provides a method for preparing a photovoltaic back sheet, including:

Forming a matrix layer on the lower surface of the composite fiber layer;

Wherein the composite fiber layer comprises a resin matrix, and continuous fibers and short fibers dispersed in the resin matrix.

Optionally, the preparation method of the composite fiber layer comprises the following steps:

Mixing the short fibers with the resin matrix forming resin to obtain a first mixture;

After the continuous fibers are impregnated and wrapped by the first mixture, the continuous fibers and the short fibers are dispersed in the resin matrix forming resin, and fiber reinforced thermoplastic material strips are formed by extrusion;

Solidifying and granulating the fiber reinforced thermoplastic material strips to obtain fiber reinforced thermoplastic particles;

and carrying out calendaring molding on the fiber reinforced thermoplastic particles to form a composite fiber layer.

Optionally, the method for preparing the photovoltaic backboard further comprises:

Coating a weather-resistant layer material on the upper surface of the composite fiber layer to form a weather-resistant layer;

And coating an adhesive layer material on the lower surface of the substrate layer to form an adhesive layer.

In a third aspect, an embodiment of the present application provides a photovoltaic module, including the photovoltaic back sheet provided in any one of the embodiments above;

The photovoltaic backboard is arranged on one side of the backlight surface of the solar cell.

The embodiment of the application adopts the technical scheme and can have the following advantages:

The photovoltaic backboard comprises a composite fiber layer and a matrix layer. The composite fiber layer takes continuous fibers as a framework and short fibers as a filler, and the continuous fibers and the short fibers are dispersed in a resin matrix, so that the mechanical strength, the shock resistance and the wear resistance of the photovoltaic backboard can be enhanced. The photovoltaic backboard in the application embodiment is light in weight and has good mechanical property, wear resistance, chemical stability and environmental aging resistance.

Drawings

In the drawings, the same reference numerals refer to the same or similar parts or elements throughout the several views unless otherwise specified. The figures are not necessarily drawn to scale. It is appreciated that these drawings depict only some embodiments according to the disclosure and are not therefore to be considered limiting of its scope.

Fig. 1 is a schematic structural diagram of a photovoltaic backsheet of embodiment 1 of the present application;

FIG. 2 is a schematic structural view of a composite fiber layer according to embodiment 2 of the present application;

fig. 3 is a schematic structural view of the photovoltaic backsheet of comparative example 1.

Reference numerals illustrate:

1. The weather-proof layer, the composite fiber layer, the matrix layer, the bonding layer, the continuous fiber, the short fiber and the resin matrix, wherein the continuous fiber is a composite fiber, the resin matrix is a composite fiber, and the resin matrix is a composite fiber.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings. In the drawings, the size of layers, regions, elements and their relative sizes may be exaggerated for clarity. Wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

As shown in fig. 1 and 2, the embodiment of the application provides a photovoltaic backboard, which comprises a composite fiber layer 2 and a matrix layer 3 which are sequentially stacked;

Wherein the composite fiber layer 2 includes a resin matrix 7, and continuous fibers 5 and short fibers 6 dispersed in the resin matrix 7.

In the embodiment of the application, the photovoltaic backboard comprises a composite fiber layer and a matrix layer. As shown in FIG. 2, the composite fiber layer 2 uses continuous fibers 5 as a framework and short fibers 6 as a filler, and the continuous fibers 5 and the short fibers 6 are dispersed in a resin matrix 7, so that the mechanical strength, impact resistance and wear resistance of the photovoltaic back panel can be enhanced. The photovoltaic backboard in the application embodiment is light in weight and has good mechanical property, wear resistance, chemical stability and environmental aging resistance.

In some embodiments, the continuous fibers comprise one or more of glass fibers, carbon fibers, aramid fibers, alumina fibers, polyester fibers. In some embodiments, the length of the continuous fibers is 100mm or greater. The continuous fibers are high-performance fibers, have good mechanical properties and corrosion resistance, are low in density and light in weight, and can be used for preparing the photovoltaic back plate with high strength and light weight.

In some embodiments, the staple fibers comprise one or both of glass fibers and carbon fibers, and the staple fibers have a length of 0.1-1mm. Both glass fibers and carbon fibers have good abrasion resistance and chemical resistance. Short fibers with a length of 0.1-1mm can be effectively combined with the resin matrix to form a uniform composite material without significantly increasing the weight of the composite material.

In some embodiments, the resin matrix forming resin comprises a first thermosetting resin or a first thermoplastic resin.

In some embodiments, the first thermoplastic resin comprises one or more of polypropylene resin (PP), polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polyethylene resin (PE), polyamide resin (PA). The thermoplastic resins are all light materials, have good mechanical properties, chemical resistance, electrical insulation and other characteristics, and can ensure the stability and durability of the photovoltaic backboard.

In some embodiments, the first thermosetting resin comprises one or more of fluorocarbon resin, acrylic resin, phenolic resin, urea resin.

In some embodiments, the mass ratio of the continuous fibers, the staple fibers, and the resin matrix forming resin in the composite fiber layer is (1.5-3): (1-1.5): 1. By precisely controlling the mass ratio of the continuous fiber, the short fiber and the resin matrix, the mechanical property and the weather resistance of the composite fiber layer can be optimized, and when the mass ratio of the three components is (1.5-3): 1-1.5): 1, the mechanical property and the weather resistance of the photovoltaic backboard can reach the optimal state. Specifically, the mass ratio of the continuous fibers, the short fibers, and the resin matrix forming resin may be 1.5:1.5:1, 2:1.5:1, 2.5:1.5:1, 3:1.5:1, 1.5:1:1, 2:1:1, 2.5:1:1, 3:1:1.

In some embodiments, the matrix layer forming resin comprises a second thermosetting resin or a second thermoplastic resin.

In some embodiments, the second thermoplastic resin comprises one or more of polypropylene resin (PP), polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polyethylene resin (PE), polyamide resin (PA). These resin materials have not only a lower density but also good mechanical properties as compared with conventional glass matrix layers, and as a matrix layer, can give the photovoltaic back sheet sufficient mechanical strength and support.

In some embodiments, the second thermosetting resin comprises one or more of fluorocarbon resin, acrylic resin, phenolic resin, urea resin.

In some embodiments, as shown in fig. 1, the photovoltaic backsheet further comprises a weatherable layer 1, the weatherable layer 1 being located on a side of the composite fiber layer 2 remote from the matrix layer 3. The weather-resistant layer can reduce the influence of ultraviolet rays and external environment on the photovoltaic backboard.

In some embodiments, the weathering layer is cured from a first fluorine-containing coating comprising a fluorocarbon resin and a first curing agent.

In some embodiments, as shown in fig. 1, the photovoltaic backsheet further comprises an adhesive layer 4, the adhesive layer 4 being located on the side of the base layer 3 remote from the composite fibre layer 2. The bonding layer is used for bonding and assembling the subsequent photovoltaic backboard and other layer structures in the photovoltaic module.

In some embodiments, the tie layer is formed by curing a second fluorine-containing coating comprising a fluorocarbon resin and a second curing agent.

The fluorine-containing coating (comprising fluorocarbon resin and curing agent and other substances in some cases) has excellent weather resistance and chemical resistance, the fluorocarbon resin and the curing agent undergo curing reaction to form a weather-resistant layer or a bonding layer with macromolecular substances, and the combination of the fluorocarbon resin and the curing agent enhances the durability and the protection performance of the coating. Therefore, the weather-resistant layer and/or the bonding layer formed by curing the fluorine-containing coating can effectively resist ultraviolet rays, moisture and other environmental factors to corrode the photovoltaic backboard, and the service life of the photovoltaic backboard is prolonged.

In alternative embodiments, the first curing agent may include one or more of a peroxide-based curing agent, an isocyanate-based curing agent, and an organic acid-based curing agent.

In alternative embodiments, the second curing agent may include one or more of a peroxide-based curing agent, an isocyanate-based curing agent, and an organic acid-based curing agent.

In an alternative embodiment, the mass ratio of fluorocarbon resin to first curative in the first fluorine-containing coating is (40-70): 2-8. In the first fluorine-containing coating, the proportion of the fluorocarbon resin is higher, namely the fluorine content is higher, so that the weather resistance can be fully exerted, the protection effect on the photovoltaic backboard is realized, and the backboard aging problem caused by factors such as ultraviolet rays, water oxygen and the like can be effectively prevented. In the first fluorine-containing paint, the mass ratio of the fluorocarbon resin to the first curing agent may also be (60-70): 2-5.

In an alternative embodiment, the mass ratio of fluorocarbon resin to second curing agent in the second fluorine-containing coating is (10-30): 0.3-4. In the second fluorine-containing coating, the proportion of fluorocarbon resin is lower, namely the main function of the bonding layer is to fully bond the photovoltaic backboard and other layer structures in the component, so that the photovoltaic backboard is ensured not to delaminate, the requirement on weather resistance is lower than that of the weather-resistant layer, and the fluorine content can be reduced. In the second fluorine-containing paint, the mass ratio of the fluorocarbon resin to the second curing agent may also be (10-20): (0.3-2).

In alternative embodiments, the first and/or second fluorine-containing coating materials further comprise other thermosetting resins (thermosetting resins other than fluorocarbon resins, e.g., acrylic resins, polyester resins). The fluorocarbon resin and other thermosetting resins are compounded to form the composite resin, so that the molecular structure is stable, and the mechanical property of the photovoltaic backboard are improved. When the first fluorine-containing coating contains acrylic resin, the mass ratio of fluorocarbon resin, acrylic resin and first curing agent is (60-70): 20-30): 2-5. When the second fluorine-containing coating contains polyester resin, the mass ratio of the fluorocarbon resin to the polyester resin to the second curing agent is (10-20): (70-80): (0.3-2).

In some embodiments, the thickness of the composite fiber layer is 30-100 μm. If the thickness of the composite fiber layer is small, the supporting effect cannot be fully exerted, the strength of the photovoltaic backboard is insufficient, even delamination phenomenon occurs, and if the thickness of the composite fiber layer is large, the strength change is small along with the increase of the thickness, but the cost is increased. When the thickness of the composite fiber layer is controlled to be 30-100 mu m, the photovoltaic backboard has higher strength, and the cost can be reasonably controlled. Specifically, the thickness of the composite fiber layer may be 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm.

In some embodiments, the base layer thickness is 275-315 μm. When the thickness of the matrix layer is 275-315 μm, the photovoltaic backboard has enough structural stability while keeping the weight of the photovoltaic backboard light. Specifically, the thickness of the base layer may be 275 μm, 80 μm, 285 μm, 290 μm, 295 μm, 300 μm, 305 μm, 310 μm, 315 μm.

In some embodiments, the weathering layer has a thickness of 25-105 μm. In other embodiments, the thickness of the adhesive layer is 5-40 μm. The thicknesses of the weather-resistant layer and the bonding layer are 25-105 mu m and 5-40 mu m respectively, the weather-resistant layer which is too thin may cause insufficient ultraviolet resistance and water vapor resistance and reduce the durability of the backboard, the bonding layer which is too thin may cause infirm interlayer bonding and peeling or damage, and the weather-resistant layer or the bonding layer which is too thick may increase the weight and cost of the photovoltaic backboard. Specifically, the thickness of the weathering layer may be 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 105 μm. Specifically, the thickness of the adhesive layer may be 5 μm, 10 μm, 20 μm, 30 μm, 40 μm.

The embodiment of the application provides a preparation method of a photovoltaic backboard, which comprises the following steps:

s100, providing a composite fiber layer, wherein the composite fiber layer comprises a resin matrix, and continuous fibers and short fibers dispersed in the resin matrix;

and S200, forming a matrix layer on the lower surface of the composite fiber layer.

In some embodiments, the method of making a photovoltaic backsheet further comprises:

S300, coating a weather-resistant layer material on the upper surface of the composite fiber layer to form a weather-resistant layer;

and S400, coating the adhesive layer material on the lower surface of the substrate layer to form the adhesive layer.

In some embodiments, in step S100, a method of preparing a composite fiber layer includes:

S110, mixing the short fibers with the resin matrix forming resin, adding the mixture into a single screw extruder to obtain a first mixture, and extruding the first mixture into an extruder head die;

s120, feeding the continuous fibers into an extruder head die under the traction of a traction device, so that the continuous fibers are immersed and wrapped by the first mixed material and then extruded to form fiber reinforced thermoplastic material strips;

S130, cooling, solidifying and granulating the fiber reinforced thermoplastic material strips to obtain fiber reinforced thermoplastic particles;

And S140, carrying out calendaring molding on the fiber reinforced thermoplastic particles by using a matched single-screw extruder and a calendaring die head to form a composite fiber layer.

In an alternative embodiment, in step S110, in the process of calendaring the fiber reinforced thermoplastic particles to form the composite fiber layer, the temperature distribution from the feed inlet of the single screw extruder to the calendaring die is 160 ℃, 170 ℃, 185 ℃ and 200 ℃, the screw rotation speed is 60r/min-80r/min (for example, 60r/min, 70r/min and 80 r/min), and the rotation speed of the calendaring roller is 15r/min-35r/min (for example, 15r/min, 20r/min, 25r/min, 30r/min and 35 r/min). The temperature gradually increases from the feed throat of the single screw extruder to the calendaring die, which arrangement aids in uniform melting and flow of the material, while also helping to reduce degradation of the material. The rotation speeds of the rolling rollers are different, so that rolled films with different orientation degrees can be prepared.

In an alternative embodiment, continuous fibers and short fibers are simultaneously present in the composite fiber layer, wherein the continuous fibers are used as a framework structure to form a grid-like structure composed of warp yarns and weft yarns, and the short fibers are 0.1-1mm in length and different in length and are distributed in gaps of the framework structure in an irregular manner.

In an alternative embodiment, in step S200, forming the matrix layer on the lower surface of the composite fiber layer includes uniformly placing the matrix layer material on the lower surface of the composite fiber layer, pressing with a high-temperature roller, and cooling to form the matrix layer. Specifically, an extrusion device is adopted to extrude the matrix layer material, so that the matrix layer material with the thickness of 0.27-0.32mm is arranged on the lower surface of the composite fiber layer, wherein the extrusion temperature is 80-300 ℃.

In an alternative embodiment, in step S300, the weather-resistant layer material is coated on the upper surface of the composite fiber layer, and the weather-resistant layer is formed through a curing process, and in step S400, the bonding layer material is coated on the lower surface of the substrate layer, and the bonding layer is formed through a curing process. Wherein the curing process in step S300 and step S400 may be performed simultaneously, and the weather-resistant layer and the adhesive layer are simultaneously formed by one-time curing. Specifically, when the weather-resistant layer and the bonding layer are formed, the weather-resistant layer material can be coated on the upper surface of the composite fiber layer, the bonding layer material can be coated on the lower surface of the matrix layer, and then the weather-resistant layer material and the bonding layer material are simultaneously cured through a one-time curing process to form the weather-resistant layer and the bonding layer.

In an alternative embodiment, in step S300 and step S400, the curing process includes a pre-curing step and a full curing step. In an alternative embodiment, the pre-curing step includes curing the composite sheet coated with the weathering layer material and the tie layer material in an environment having a temperature of 120-175 ℃ (e.g., 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 175 ℃) for 1-20 minutes (e.g., 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes). Specifically, the pre-curing step is performed in a tunnel oven. In an alternative embodiment, the step of fully curing includes curing the pre-cured composite board in an environment having a temperature of 50-60 ℃ (e.g., 50 ℃, 55 ℃, 60 ℃), for 24-30 hours (e.g., 24 hours, 26 hours, 28 hours, 30 hours). Specifically, the full cure step is performed in a drying room.

The materials of the surface layers of the weather-resistant layer and the bonding layer are crosslinked and cured through a pre-curing step, and the solvents in the weather-resistant layer material and the bonding layer material are volatilized; through the complete curing step, the fluorocarbon resin or thermosetting resin and the corresponding curing agent undergo complete crosslinking curing reaction.

The embodiment of the application provides a photovoltaic module, which comprises the photovoltaic backboard provided by any one of the embodiments, wherein the photovoltaic backboard is arranged on one side of a backlight surface of a solar cell.

The embodiment of the application provides a preparation method of a photovoltaic module, which comprises the following steps:

And laminating and packaging the packaging glass, the adhesive film, the solar cell, the adhesive film and the photovoltaic backboard in a high-temperature negative pressure environment to obtain the photovoltaic module, wherein the packaging glass is positioned on the light incident surface of the solar cell, the photovoltaic backboard is positioned on the backlight surface of the solar cell, and the photovoltaic backboard is provided by any one of the embodiments.

The encapsulation glass is the outermost layer of the photovoltaic module for protecting the solar cell from external environments such as moisture, oxygen and mechanical impact, and is required to have good visible light transmittance.

Solar cells are the core of photovoltaic modules. In some embodiments, the solar cell includes one or more of a PN junction device containing a III-V or II-IV element, a Cu-In-Ga-Se (CIGS) thin film device, an organic sensitizer device, an organic thin film device, a quantum dot thin film device, an amorphous silicon solar cell, a microcrystalline silicon solar cell, and a crystalline silicon solar device. In other embodiments, the solar cell may also be a Heterojunction (HJT) solar cell.

The photovoltaic back plate is a back protective layer of the photovoltaic module, and the photovoltaic back plate provided by any one of the embodiments of the application is adopted, so that the prepared photovoltaic module is light in weight and has good mechanical property, wear resistance, chemical stability and environmental aging resistance.

The photovoltaic module generally comprises two layers of adhesive films which are respectively positioned on the front side and the back side of the solar cell, wherein the adhesive films are used for respectively adhering the packaging glass and the photovoltaic backboard with the solar cell to fix the solar cell, and the components of the two layers of adhesive films can be the same or different. In some embodiments, the adhesive film may be a random copolymer of Ethylene and Vinyl Acetate (EVA) adhesive film. The EVA adhesive film has good visible light transmittance, ageing resistance and sealing performance, and can effectively block water vapor and gas.

And placing and laminating all the layers of materials of the photovoltaic module in sequence under a high-temperature negative pressure environment. And the adhesive film is melted and flows through heating and applying pressure, so that gaps between the battery and the packaging glass or the photovoltaic backboard are uniformly filled, and the tightness of the assembly and the uniform distribution of the adhesive film are ensured. Wherein the temperature during encapsulation may be 120-140 ℃ (e.g., 120 ℃, 130 ℃, or 140 ℃). After lamination, the adhesive film is cured to form a firm adhesive layer, and the materials of the layers are tightly combined together.

The following specific examples illustrate the application in further detail, but are not to be construed as limiting the application. Modifications and substitutions of the structure of the present application without departing from the spirit and essence of the application are all within the scope of the present application.

Example 1

As shown in fig. 1 and 2, the photovoltaic backsheet of example 1 comprises a weather-resistant layer 1, a composite fiber layer 2, a base layer 3, and an adhesive layer 4, which are laminated;

Wherein the composite fiber layer 2 comprises a resin matrix 7 (thermoplastic resin), and continuous fibers 5 and short fibers 6 dispersed in the resin matrix 7, wherein the continuous fibers are glass fibers, the short fibers are glass fibers (the length is 0.1-1 mm), the thermoplastic resin is polyamide resin (PA), and the mass ratio C1 of the continuous fibers, the short fibers and the thermoplastic resin is 2.3:1.2:1;

The matrix layer is polyethylene terephthalate resin (PET);

the weather-resistant layer is formed by curing reaction of fluorocarbon resin, acrylic resin and a first curing agent (trimethylhexamethylene diisocyanate), wherein the mass ratio C2 of the fluorocarbon resin, the acrylic resin and the first curing agent is 64:26:3;

The bonding layer is formed by curing reaction of fluorocarbon resin, polyester resin and a second curing agent (dibenzoyl peroxide), wherein the mass ratio C3 of the fluorocarbon resin, the polyester resin and the second curing agent is 16:74:0.5.

The method for preparing the photovoltaic backsheet of example 1 comprises:

s110a, mixing the short fibers and the thermoplastic resin, adding the mixture into a single screw extruder to obtain a first mixture, and extruding the first mixture into an extruder head die;

S120a, feeding the continuous fibers into an extruder head die under the traction of a traction device, so that the continuous fibers are immersed and wrapped by the first mixture and then extruded to form fiber reinforced thermoplastic material strips;

s130a, cooling, solidifying and granulating the fiber reinforced thermoplastic material strips to obtain fiber reinforced thermoplastic particles;

S140a, carrying out calendaring molding on fiber reinforced thermoplastic particles by using a matched single screw extruder and a calendaring die head to form a composite fiber layer with the thickness of 50 mu m;

S200a, extruding a matrix layer material by adopting an extrusion device at the extrusion temperature of 200 ℃ to enable the matrix layer material with the thickness of 0.2mm to be placed on the lower surface of the composite fiber layer, and then forming a matrix layer with the thickness of 275 mu m after high-temperature roller pressing and cooling;

S300a, coating a weather-resistant layer material on the upper surface of a composite fiber layer, coating an adhesive layer material on the lower surface of a matrix layer, and forming a weather-resistant layer with the thickness of 37 mu m on the upper surface of the composite fiber layer and forming an adhesive layer with the thickness of 15 mu m on the lower surface of the matrix layer through a pre-curing step and a full curing, wherein the pre-curing temperature T1 is 160 ℃, the pre-curing time T1 is 3 minutes, the full curing temperature T2 is 50 ℃, and the full curing time T2 is 28 hours.

Examples 2 to 8

The photovoltaic back sheets of examples 2 to 8 were produced with reference to the production method of example 1, except that the materials and production parameters of the layers of the photovoltaic back sheets of examples 2 to 8 were different, and the materials and production parameters of the layers of the photovoltaic back sheets of examples 2 to 8 are shown in table 1.

TABLE 1

In order to more clearly illustrate the technical effects of the embodiment of the present application, the present application also provides comparative example 1.

Comparative example 1

As shown in fig. 3, the photovoltaic backsheet of comparative example 1 includes a weatherable layer 1, a base layer 3, and an adhesive layer 4, which are sequentially laminated, excluding a composite fiber layer;

The materials of the weather-resistant layer, the base layer, and the adhesive layer of the photovoltaic backsheet of comparative example 1 were the same as those of the photovoltaic backsheet of example 1.

A method of making a photovoltaic backsheet of comparative example 1 comprising:

S100b, extruding a matrix layer material by adopting an extrusion device at the extrusion temperature of 200 ℃ to form a matrix layer after cooling, wherein the extrusion thickness is 275 mu m;

S200b, coating a weather-resistant layer material on the upper surface of the substrate layer, coating an adhesive layer material on the lower surface of the substrate layer, forming a weather-resistant layer with the thickness of 37 mu m on the upper surface of the substrate layer and forming an adhesive layer with the thickness of 15 mu m on the lower surface of the substrate layer through a pre-curing step and a full curing, wherein the pre-curing temperature T1 is 160 ℃, the pre-curing time T1 is 3 minutes, the full curing temperature T2 is 50 ℃, and the full curing time T2 is 28 hours.

The present application performs tensile strength test on the photovoltaic back sheets of examples 1 to 8 and comparative example 1 by a universal stretcher with reference to ASTM D-882 standard, 5 specimens are tested for each example, and the measured values are averaged, and the test results are shown in table 2.

TABLE 2

From the data in table 2, the tensile strength of the photovoltaic modules of examples 1 to 8 of the present application was significantly greater than that of the photovoltaic module of comparative example 1. This is because the photovoltaic back sheet of embodiments 1 to 8 of the present application has a composite fiber layer formed of long fibers and short fibers and a resin, and when subjected to a stretching action in the transverse or longitudinal direction, the long fiber skeleton in a net structure can effectively bear a stretching load in the fiber direction, while the long fibers are interwoven with each other, so that the fibers are mutually supported, the strength of the back sheet material is effectively improved, and in addition, the short fibers and the resin are sufficiently impregnated to wrap the long fiber skeleton, and the tensile strength of the photovoltaic back sheet can be effectively improved.

In summary, the photovoltaic back sheet according to the embodiment of the application includes a composite fiber layer and a matrix layer. The composite fiber layer takes continuous fibers as a framework and short fibers as a filler, and the continuous fibers and the short fibers are dispersed in a resin matrix, so that the mechanical strength, the shock resistance and the wear resistance of the photovoltaic backboard can be enhanced. The photovoltaic backboard in the application embodiment is light in weight and has good mechanical property, wear resistance, chemical stability and environmental aging resistance.

It is noted that the terms "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience of description and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the application. The orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the process is carried out, the exemplary term "above" may be included. Upper and lower. Two orientations below. The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first," "second," "front," "back," and the like in the description and claims of the present application and in the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should also be noted that references to "one embodiment," "another embodiment," "an embodiment," etc., in the present application mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application as broadly described. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is intended that such feature, structure, or characteristic be implemented within the scope of the application.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

It should be noted that the foregoing is only a preferred embodiment of the present application, and is not intended to limit the scope of the present application, and all equivalent structures or equivalent processes using the descriptions of the present application and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present application.

Claims (15)

1. The photovoltaic backboard is characterized by comprising a composite fiber layer and a matrix layer which are sequentially laminated;

Wherein the composite fiber layer comprises a resin matrix, and continuous fibers and short fibers dispersed in the resin matrix.

2. The photovoltaic backsheet according to claim 1, wherein the continuous fibers comprise one or more of glass fibers, carbon fibers, aramid fibers, alumina fibers, polyester fibers, and/or

The length of the continuous fiber is more than or equal to 100mm.

3. The photovoltaic backsheet according to claim 1, wherein the short fibers comprise one or both of glass fibers and carbon fibers, and the short fibers have a length of 0.1-1mm.

4. The photovoltaic backsheet of claim 1 wherein the resin matrix forming resin comprises a first thermosetting resin or a first thermoplastic resin.

5. The photovoltaic backsheet of claim 4 wherein the first thermoplastic resin comprises one or more of a polypropylene resin, a polyethylene terephthalate resin, a polybutylene terephthalate resin, a polyethylene resin, a polyamide resin.

6. The photovoltaic backsheet according to claim 1, characterized in that the mass ratio of the continuous fibers, the short fibers and the resin matrix forming resin in the composite fiber layer is (1.5-3): (1-1.5): 1.

7. The photovoltaic backsheet of claim 1 wherein the matrix layer forming resin comprises a second thermosetting resin or a second thermoplastic resin.

8. The photovoltaic backsheet of claim 7 wherein the second thermoplastic resin comprises one or more of a polypropylene resin, a polyethylene terephthalate resin, a polybutylene terephthalate resin, a polyethylene resin, a polyamide resin.

9. The photovoltaic backsheet of claim 1 wherein the photovoltaic backsheet comprises,

The photovoltaic back sheet further comprises a weather-resistant layer which is positioned on one side of the composite fiber layer away from the matrix layer, and/or

The photovoltaic backboard further comprises an adhesive layer, and the adhesive layer is located on one side, far away from the composite fiber layer, of the substrate layer.

10. The photovoltaic backsheet of claim 9 wherein the photovoltaic backsheet comprises,

The weather-resistant layer is formed by curing a first fluorine-containing coating, the first fluorine-containing coating comprises fluorocarbon resin and a first curing agent, and/or

The adhesive layer is formed by curing a second fluorine-containing coating, and the second fluorine-containing coating comprises fluorocarbon resin and a second curing agent.

11. The photovoltaic backsheet of claim 9 wherein the photovoltaic backsheet comprises,

The thickness of the composite fiber layer is 30-100 μm, and/or

The thickness of the substrate layer is 275-315 μm, and/or

The thickness of the weather-resistant layer is 25-105 μm, and/or

The thickness of the adhesive layer is 5-40 mu m.

12. A method of making a photovoltaic backsheet comprising:

Forming a matrix layer on the lower surface of the composite fiber layer;

Wherein the composite fiber layer comprises a resin matrix, and continuous fibers and short fibers dispersed in the resin matrix.

13. The method of manufacturing a photovoltaic backsheet according to claim 12, wherein the method of manufacturing the composite fiber layer comprises:

Mixing the short fibers with the resin matrix forming resin to obtain a first mixture;

After the continuous fibers are impregnated and wrapped by the first mixture, the continuous fibers and the short fibers are dispersed in the resin matrix forming resin, and fiber reinforced thermoplastic material strips are formed by extrusion;

Solidifying and granulating the fiber reinforced thermoplastic material strips to obtain fiber reinforced thermoplastic particles;

and carrying out calendaring molding on the fiber reinforced thermoplastic particles to form a composite fiber layer.

14. The method of manufacturing a photovoltaic backsheet according to claim 12, further comprising:

Coating a weather-resistant layer material on the upper surface of the composite fiber layer to form a weather-resistant layer;

And coating an adhesive layer material on the lower surface of the substrate layer to form an adhesive layer.

15. A photovoltaic module comprising the photovoltaic backsheet of any one of claims 1 to 11;

The photovoltaic backboard is arranged on one side of the backlight surface of the solar cell.