CN218482257U

CN218482257U - Weather-resistant film for solar cell front plate

Info

Publication number: CN218482257U
Application number: CN202222870001.4U
Authority: CN
Inventors: 吴培服; 吴迪; 孙化斌; 池卫; 臧辉; 孙健
Original assignee: Jiangsu Shuangxing Color Plastic New Materials Co Ltd
Current assignee: Jiangsu Shuangxing Color Plastic New Materials Co Ltd
Priority date: 2022-10-29
Filing date: 2022-10-29
Publication date: 2023-02-14
Anticipated expiration: 2032-10-29

Abstract

The application discloses solar cell is resistant time membrane for front panel, wherein, the both sides surface of resistant time membrane (1) is formed with a plurality of equidistant parallel arrangement's cross-section for isosceles triangle's sawtooth stripe (11), and the surface of sawtooth stripe (11) is formed with one deck protective layer (12), the sawtooth stripe (11) mutually perpendicular of the both sides surface of resistant time membrane (1) sets up, and the minimum clearance between adjacent sawtooth stripe (11) is 0-5 mu m. The utility model provides a weather-resistant film can increase the area of contact with the adhesive through the sawtooth stripe that its surface set up to increase weather-resistant film's whole adhesive force, avoided the easy problem of delaminating of weather-resistant film.

Description

Weather-resistant film for solar cell front plate

Technical Field

The application relates to a weather-resistant film for a solar cell front panel.

Background

The solar cell front plate in the prior art usually adopts a transparent fluorine-containing plastic film as an outer weather-resistant film, but the fluorine-containing film has the characteristics of high water permeability, poor wear resistance, low surface energy, easiness in delamination, easiness in dust adsorption and the like, and after the conventional photovoltaic module is used for a period of time outdoors, risks such as reduction of module power generation and delamination still occur.

CN 115179631A discloses a packaging material, which comprises a fluorine-containing plastic film and a water-blocking film, wherein the fluorine-containing plastic film and the water-blocking film are connected through a weather-resistant pressure-sensitive adhesive layer, and a wear-resistant water-blocking layer is arranged on the surface of one side of the fluorine-containing plastic film, which is far away from the water-blocking film; wherein, the fluorine-containing plastic film is subjected to low-pressure low-temperature plasma surface treatment; the raw materials of the weather-resistant pressure-sensitive adhesive layer comprise acrylate pressure-sensitive adhesive, liquid ultraviolet absorbent combination and solid ultraviolet absorbent combination. In the prior art, in order to avoid the problems of water absorption and wear resistance of the fluorine-containing plastic film, a water-blocking film is additionally arranged, but the weather resistance of the water-blocking film is weaker than that of the fluorine-containing plastic film, and the water-blocking film becomes brittle and cracks before the fluorine-containing plastic film, so that the defects of the fluorine-containing plastic film cannot be fundamentally overcome.

Disclosure of Invention

The technical problem to be solved by the present application is to provide a weatherable film for a solar cell front panel to reduce or avoid the aforementioned problems.

In order to solve the technical problem, the application provides a weather-resistant film for a solar cell front plate, wherein a plurality of equally-spaced parallel saw tooth stripes with isosceles triangular sections are formed on the surfaces of two sides of the weather-resistant film, a protective layer is formed on the surface of each saw tooth stripe through vacuum sputtering, and the saw tooth stripes on the surfaces of the two sides of the weather-resistant film are mutually perpendicular; the minimum gap between adjacent sawtooth stripes is 0-5 μm.

Preferably, the weatherable film has a maximum thickness of 20 to 30 μm.

Preferably, the thickness of the protective layer is 1 to 3 μm.

Preferably, the included angle between the length direction of the sawtooth stripes and the four rectangular sides of the weather-resistant film is 45 degrees.

The utility model provides a weather-resistant film can increase the area of contact with the adhesive through the sawtooth stripe that its surface set up to increase weather-resistant film's whole adhesive force, avoided the easy problem of delaminating of weather-resistant film. In addition, the same sawtooth stripes are formed on the two side surfaces of the weather-resistant film, so that the manufacturing cost can be reduced, and the excellent dust adsorption resistance can be formed on the outer side.

Drawings

The drawings are only for purposes of illustrating and explaining the present application and are not to be construed as limiting the scope of the present application.

Fig. 1 is a schematic view showing the structure of a weatherable film for a front plate of a solar cell according to one embodiment of the present application.

Fig. 2 is a schematic cross-sectional view showing a weatherable film for a solar cell front sheet according to another embodiment of the present application.

Fig. 3 shows a schematic structural view of a weatherable film for a front plate of a solar cell according to yet another embodiment of the present application.

Fig. 4 and 5 show schematic front and back views of the weatherable film of fig. 3, respectively.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present application, embodiments of the present application will now be described with reference to the accompanying drawings. Wherein like parts are given like reference numerals.

A solar cell photovoltaic module with a typical structure is composed of a front plate, a solar cell piece, an encapsulating material and a back plate. The solar cell photovoltaic module is generally applied to outdoor environment and is subjected to tests such as wind, sunlight, rain, dust, abrasion and the like, so that the performance requirement on the front plate, namely the light receiving surface, is high, and the front plate, namely the solar cell photovoltaic module needs to have high light transmittance, water resistance, UV resistance and certain mechanical strength. The outermost surface layer of the front panel is mainly used for reinforcement, weather resistance, UV resistance, moisture resistance, low dielectric constant, high breakdown voltage, etc., and is generally called a weather-resistant layer. Some of the existing weathering layers use PVDF (polyvinylidene fluoride) coatings and some use fluoroplastic films. The weather-resistant layer and the supporting base film of the front plate are bonded into a whole through adhesive glue.

The PVDF coating is mainly made of bonding resin, the content of the PVDF is limited, and the weather-resistant effect is not as good as that of a weather-resistant film with the PVDF as the main body. However, PVDF weatherable films have a problem of easy delamination due to low surface energy and insufficient adhesion, and further, have a problem of low abrasion resistance on the outer surface and are prone to dust adsorption.

In view of the above, the present application provides a weatherable film for a solar cell front plate, which is mainly composed of PVDF, wherein the mass content of PVDF in the weatherable film is greater than or equal to 90%, and in order to improve the performance of the weatherable film, an ultraviolet light absorber, an abrasion-resistant filler, and the like may be added.

Further, as shown in the figure, the whole weatherable film of the present application is denoted by reference numeral 1, a plurality of saw-tooth stripes 11 having isosceles triangle-shaped cross sections are formed on the two side surfaces of the weatherable film 1, and the saw-tooth stripes on the two sides of the weatherable film are identical. The size scale of the weatherable film shown in the figure is magnified for easy observation and understanding, the actual sawtooth stripes are relatively small in size, and the surface has only small texture which is not easy to be perceived, and the overall light transmittance of the weatherable film is not influenced. In one particular embodiment, the weatherable film has a maximum thickness of 20-30 μm.

The existing PVDF weather-resistant film has the problem of easy delamination when being bonded on a base film through an adhesive due to low surface energy and insufficient bonding force. In order to overcome the technical problem, the sawtooth stripes are formed on the surface of the weather-resistant film, the contact area between the sawtooth stripes and the adhesive can be increased, for example, when the vertex angle of an isosceles trapezoid of the sawtooth stripes is 60 degrees, the surface area of the sawtooth stripes can be doubled, so that the overall adhesive force of the weather-resistant film is increased, and the problem that the weather-resistant film is easy to delaminate is avoided.

It should be noted that, in practice, only the sawtooth stripes need to be arranged on the inner side of the weatherable film to improve the overall adhesion of the weatherable film, but the stripes are very tiny and difficult to observe, and for the convenience of assembly operation, the inventor chooses to form the same sawtooth stripes on both side surfaces of the weatherable film at the same time, so that both sides can be coated with the film conveniently, and the application range of the weatherable film can be improved. The inventor thinks that the originally located outside sawtooth stripes do not assume any effect, however, in the actual laying experiment process, the inventor finds that if the scale of the sawtooth stripes formed on the surface of the weather-resistant film is smaller than a certain range, the surface of the weather-resistant film can play a self-cleaning effect, the adhesion force of dust on the surface of the weather-resistant film can be reduced, and rainwater can easily flush the adhered dust. For example, in one embodiment, it is preferable that the isosceles triangle of the sawtooth stripe 11 has a length of a base of 5 to 10 μm, an apex angle of 45 to 135 degrees and a height of 5 to 10 μm, and a minimum gap between adjacent sawtooth stripes 11 is 0 to 5 μm. The same sawtooth stripes are formed on the two side surfaces of the weather-resistant film, so that the manufacturing cost can be reduced, and the sawtooth stripes in the size range can be selected to obtain better bonding performance on the inner side and form excellent dust adsorption resistance on the outer side.

In addition, under the condition that the same sawtooth stripes are formed on the two sides, the sawtooth stripes possibly reflect sunlight, and the utilization rate of the solar cell is reduced. For example, when the flexible solar cell is integrated in a building, the direction of the flexible solar cell is not adjustable, and when the sun deflection angle is just vertical to one side surface of the sawtooth stripe, a part of light can be reflected by the surface, and of course, the flexible solar cell can be avoided by adjusting the installation angle of the sawtooth stripe during installation, but the installation requirement is too high, and the flexible solar cell is difficult to operate practically. In order to avoid the sawtooth stripe of both sides to appear simultaneously because installation angle is not good and reduce the problem of sunshine utilization ratio, this application has proposed a special design, will wait to wait that sawtooth stripe 11 mutually perpendicular settings on the both sides surface of membrane 1 to can avoid forming the problem that the reflection reduces the sunshine utilization ratio in both sides simultaneously.

In addition, the sawtooth stripe on the surface of the weather-resistant film can also enable incident light to converge towards the middle of the sawtooth stripe, so that the inclination angle of the light can deflect towards the direction perpendicular to the solar cell piece as much as possible to some extent, and the utilization rate of sunlight in an inclined state is improved. The inventor uses the prism film technology in the backlight plate in the field of liquid crystal display for reference about the principle of converging light rays by the sawtooth stripes. Since the field of operation of the applicant coincided with years of development on liquid crystal displays, the inventors were able to derive from the field of liquid crystal displays, which is very different from the field, but such cross-field derivation is not obvious to a person skilled in the art of solar cells. Because the sawtooth stripes on the two sides of the weather-resistant film are perpendicular to each other, the light rays in different directions can be corrected to a certain extent, and the direction modulation effect on the light rays can be realized under the condition that the solar altitude angle changes in different directions after the weather-resistant film is laid and installed.

Further, in order to improve the adhesion of the weather-resistant film and avoid delamination, the included angle between the length direction of the sawtooth stripes and the four rectangular sides of the weather-resistant film is selected to be 45 degrees, as shown in fig. 3-5. In general, the solar cell panel is usually designed to be rectangular, four sides are perpendicular to each other, and if the length direction of the sawtooth stripes is perpendicular to one pair of rectangular sides of the weatherable film, the other pair of rectangular sides will be parallel to the length direction of the sawtooth stripes. Since the rigidity in the longitudinal direction and the rigidity in the width direction of the zigzag stripes are different, the expansion rates are also different, which causes a pair of rectangular sides of the weather-resistant film to be easily warped and delaminated. This application turns to the direction of sawtooth stripe and is 45 degrees contained angles with four rectangle limits, then because the rigidity difference of equidirectional not that the sawtooth stripe arouses can tend to averagely to the proportion of four rectangle limit diffusion, therefore can avoid the problem of the resistant membrane delaminating of waiting of causing because setting up of sawtooth stripe, further improved the structural performance of resistant membrane.

In order to improve the resistance of the weatherable film against wind and sand erosion, in another embodiment of the present application, a protective layer 12 is formed on the surface of the sawtooth pattern 11 on the surface of the weatherable film 1 by vacuum sputtering, and preferably, the protective layer 12 is made of silicon dioxide and has a thickness of 1 to 3 μm.

The method for producing the weatherable film for a solar cell front sheet according to the present application is described in further detail below with reference to the accompanying drawings. Specifically, the preparation method comprises the following steps:

first, a PVDF film composed mainly of PVDF is provided. The PVDF film can be a PVDF film with the thickness of 20-30 μm sold in the market, or a PVDF raw material particle with the mass content of more than or equal to 90 percent is added with an ultraviolet absorber, an abrasion-resistant filler and the like, and the PVDF film is formed by melt co-extrusion and then two-way stretching.

Then, a plurality of equally spaced saw-tooth stripes 11 having isosceles triangle-shaped cross sections are formed on both side surfaces of the PVDF film by hot press molding. For example, the cured zigzag stripes 11 can be obtained on the PVDF film by using two rollers arranged one above the other and having a pattern matching the shape of the zigzag stripes, passing the heated PVDF film between the two rollers, and then air-cooling or water-cooling the PVDF film. Wherein the longitudinal directions of the patterns matching with the shape of the sawtooth stripes of the two roll surfaces which are opposite up and down are arranged perpendicular to each other, so that the sawtooth stripes 11 which are perpendicular to each other can be formed on the two side surfaces of the PVDF film. For example, the pattern direction of the two roller surfaces forms an angle of 45 degrees with the advancing direction of the PVDF film, so that the sawtooth stripes 11 forming an angle of 45 degrees with the four rectangular sides of the weather-resistant film can be formed.

Thereafter, a protective layer 4 is formed on the sawtooth stripes 11 by vacuum sputtering. For example, a silicon dioxide layer with a thickness of 1-3 μm may be formed on the sawtooth pattern 11 by vacuum sputtering, and since the thickness of the formed protective layer 12 is relatively very thin, the protective layer 12 is not shown in fig. 2, and the protective layer 12 in fig. 1 is enlarged for easy understanding.

Examples 1 to 6

The weatherable film for the solar cell front sheet was prepared according to the parameters shown below.

In examples 1 to 3, the included angles between the sawtooth stripes and the rectangular sides of the weatherable film are both 45 degrees, and in examples 4 to 6, the included angles between the sawtooth stripes and the rectangular sides of the weatherable film are both 0/90 degrees, that is, the included angles between the sawtooth stripes and one pair of rectangular sides are 0 degree, and the included angles between the sawtooth stripes and the other pair of rectangular sides are 90 degrees.

Comparative examples 1 to 6

Comparative examples 1-6 PVDF films without jagged stripes were used as the weatherable films with the following parameters.

	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 6
							Thickness μm	20	22	24	26	28	30

The weatherable films of examples 1 to 6 and comparative examples 1 to 6 were respectively adhered to the surface of a 188 μm PET support base film, and the parametric properties of the examples in which the weatherable film was measured were compared as follows.

As can be seen from the comparison of performance parameters of the embodiment, the weather-resistant film for the solar cell front plate can remarkably improve the adhesive property and avoid layering under the condition of having the sawtooth stripes, can improve the light transmittance of oblique light rays, can increase the contact angle of the outer surface, improves the self-cleaning capability, and has excellent dust-resistant adsorbability.

It should be appreciated by those skilled in the art that while the present application is described in terms of several embodiments, not every embodiment includes only a single embodiment. Such descriptions are merely for clarity reasons and should be understood by those skilled in the art as a whole and the technical solutions involved in the embodiments should be considered as being combinable with each other into different embodiments to understand the scope of the present application.

The above description is only illustrative of the present invention and is not intended to limit the scope of the present invention. Any equivalent alterations, modifications and combinations that may be made by those skilled in the art without departing from the spirit and principles of this application shall fall within the scope of this application.

Claims

1. The weather-resistant film for the solar cell front plate is characterized in that a plurality of equally-spaced parallel saw tooth stripes (11) with isosceles triangle-shaped cross sections are formed on the two side surfaces of the weather-resistant film (1), a protective layer (12) is formed on the surface of each saw tooth stripe (11), the saw tooth stripes (11) on the two side surfaces of the weather-resistant film (1) are perpendicular to each other, and the minimum gap between every two adjacent saw tooth stripes (11) is 0-5 mu m.

2. The weatherable film according to claim 1, wherein the weatherable film has a maximum thickness of 20 to 30 μ ι η.

3. The weatherable film according to claim 2, wherein the protective layer (12) has a thickness of 1 to 3 μm.

4. The weatherable film according to claim 3, characterized in that the lengthwise direction of said sawtooth stripes (11) makes an angle of 45 degrees with the four rectangular sides of the weatherable film (1).