Transverse distribution co-extrusion adhesive film

Abstract

The utility model relates to a photovoltaic packaging adhesive film, and provides a transverse distribution co-extrusion adhesive film, which is sequentially provided with a first area, a first doping area firmly bonded with the side edge of the first area, a second area firmly bonded with the side edge of the first doping area, and a second doping area firmly bonded with the side edge of the second area along a first direction, and the third region is firmly bonded with the side edge of the second doped region. Therefore, the adhesive force between each region and the adjacent region of the adhesive film is strong enough, so that each region is stably and firmly formed into a whole, the whole adhesive film structure has good adhesive property, ageing resistance and water resistance, and the requirement of a photovoltaic module on the comprehensive performance of the adhesive film is met.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic modules, specifically to a transversely distributed co-extruded film. Background Technology

[0002] Photovoltaic modules require suitable encapsulating films to protect the crystalline silicon cells, solder ribbons, and busbars. Currently, the most commonly used encapsulating films are EVA and POE films. EVA films have good light transmittance and adhesion, but are prone to hydrolysis and have poor anti-aging properties. POE films are not easily hydrolyzed and have excellent anti-aging properties, but functional additives are prone to precipitation, leading to slippage during lamination.

[0003] Currently, for battery modules with high humidity and heat requirements, such as HJT, TOPCon, and perovskite battery modules, butyl rubber strips are used for edge sealing to solve the failure problem caused by water ingress at the edge of the module. However, butyl rubber strip edge sealing has the problem of mutual puncture between the rubber strip and the adhesive film during the lamination process, resulting in local water ingress channels and poor appearance.

[0004] To address the above issues, patent CN111584661A discloses a transversely multilayer co-extruded film, comprising an intermediate film layer and a border film layer co-extruded on the side of the intermediate film layer. The border film layers are located on both sides of the intermediate film layer along its length, and the intermediate film layer and the border film layers are in the same plane. The intermediate film layer is an EVA layer or an alternating layer of EVA and POE, and the border film layer is a POE layer. This patent utilizes the advantages of POE's high water resistance and resistance to hydrolysis to prevent moisture erosion of the EVA layer and improve the module's resistance to moisture. However, in this patent, the frame film layer and the middle film layer are co-extruded laterally in the same plane. In contrast, the width of conventional photovoltaic films is greater than 1 meter, but the thickness is less than 1 mm. Therefore, compared with the contact surface formed by the length and width of the film, the contact area formed by the thickness and width of the film between the frame film layer and the middle film layer is particularly small, and the contact width is less than 0.1% of the overall width of the photovoltaic film. Furthermore, EVA and POE have different polarities and poor compatibility, resulting in insufficient adhesion between the frame film layer and the middle film layer. The frame film layer and the middle film layer are prone to delamination or breakage, which will still make the module susceptible to moisture erosion and shorten its service life.

[0005] Therefore, it is necessary to develop a new type of transversely distributed co-extruded film that can improve the anti-aging properties of the film, prevent delamination or breakage, and prevent moisture from penetrating the photovoltaic module, thereby extending the service life of the photovoltaic module. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a transversely distributed co-extruded film. This film has excellent anti-aging properties and solves the problem of film delamination or breakage in the existing technology, thereby preventing moisture from penetrating the photovoltaic module and extending the service life of the photovoltaic module.

[0007] The technical solution of the transversely distributed co-extruded film provided by this utility model is as follows:

[0008] A transversely distributed co-extruded film includes a first region, a first doped region firmly bonded to the side of the first region, a second region firmly bonded to the side of the first doped region, a second doped region firmly bonded to the side of the second region, and a third region firmly bonded to the side of the second doped region.

[0009] Preferably, both the first region and the third region are POE layers.

[0010] Preferably, the second region is an EVA layer.

[0011] Preferably, the first doped region and the second doped region are EVA / POE doped regions.

[0012] Preferably, the POE mass fraction in the first doped region and the second doped region decreases towards the second region.

[0013] Preferably, the film has an overall width, and the widths of the first region and the third region independently account for 0.5-15% of the overall width.

[0014] Preferably, the widths of the first doped region and the second doped region independently account for 0.5-20% of the overall width.

[0015] Compared with the prior art, the transversely distributed co-extruded film provided by this utility model has the following beneficial effects:

[0016] 1. By setting the first doping region and the second doping region, the adhesion between the five regions and the adjacent regions is improved, so that the five regions are stably and firmly formed into one, effectively solving the problem that the frame film layer is easy to delaminate or even break with the middle film layer in the existing technology, thereby protecting the module from water vapor corrosion and extending the service life of the photovoltaic module.

[0017] 2. By rationally selecting the materials for each region of the encapsulant film—specifically, the first and third regions are both POE layers, the second region is an EVA layer, and the first and second doped regions are both EVA / POE interdoped layers—an optimized combination of film performance can be achieved, fully leveraging the advantages of each layer. Specifically, the first and third regions can fully utilize the water-blocking properties of POE to replace butyl sealant in protecting the photovoltaic module from moisture erosion; the second region can fully utilize the light transmission and adhesion advantages of EVA to ensure the aging resistance and light utilization rate of the photovoltaic module; the first doped region has both POE and EVA, and utilizing the principle of good compatibility of the same materials, it exhibits excellent adhesion to both the first and second regions; similarly, the second doped region also exhibits excellent adhesion to both the third and second regions. Thus, the entire encapsulant film structure possesses excellent adhesion, aging resistance, and water-blocking properties, meeting the comprehensive performance requirements of photovoltaic modules for the encapsulant film.

[0018] 3. By setting the proportions of the widths of the first and third regions, as well as the widths of the first and second doped regions, within the overall film width, the water-blocking performance of the first and third regions, and the bonding performance of the first and second doped regions, can be maximized. Simultaneously, the amount of POE used can be minimized, reducing the film cost and meeting market demands. Specifically, the proportion of the widths of the first and second permeable regions is significantly larger than the interface width between the border film layer and the intermediate film layer in existing technologies. This results in a more robust and stable connection between the first water-blocking region and the bonding region through the first permeable region, and similarly, a more robust and stable connection between the second water-blocking region and the bonding region through the second permeable region. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram showing the direction of the transversely distributed co-extruded film provided by this utility model.

[0021] Figure 2 A schematic diagram showing the regional distribution of the transversely distributed co-extruded film provided by this utility model.

[0022] The diagram numbers are explained as follows: 1-First region; 2-First doped region; 3-Second region; 4-Second doped region; 5-Third region. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example 1:

[0025] See Figure 1 and Figure 2 This embodiment provides a transversely distributed co-extruded film, along a predetermined direction, as if in... Figure 1 As shown in the first direction, a first region 1, a first doped region 2 firmly bonded to the side of the first region 1, a second region 3 firmly bonded to the side of the first doped region 2, a second doped region 4 firmly bonded to the side of the second region 3, and a third region 5 firmly bonded to the side of the second doped region 4 are distributed sequentially. The first region 1 and the third region 5 are both POE layers with a width of 30 micrometers, the second region 3 is an EVA layer, and the first doped region 2 and the second doped region 4 are both EVA / POE interdoped layers with a width of 50 micrometers. All regions are co-extruded into the same plane, and the width of the film is 1125 micrometers.

[0026] In other embodiments, the overall width of the film is selected from 1000 micrometers to 1400 micrometers, specifically, it can be, but is not limited to, 1000 micrometers, 1025 micrometers, 1050 micrometers, 1075 micrometers, 1100 micrometers, 1125 micrometers, 1150 micrometers, 1175 micrometers, 1200 micrometers, 1225 micrometers, 1250 micrometers, 1275 micrometers, 1300 micrometers, 1325 micrometers, 1350 micrometers, 1375 micrometers, and 1400 micrometers.

[0027] In other embodiments, the width of the first region 1 accounts for 0.5-15% of the overall width. Specifically, taking an overall width of 1250 micrometers as an example, the width of the first region 1 can be, but is not limited to, 6.25 micrometers, 10.25 micrometers, 25.5 micrometers, 50.25 micrometers, 65.5 micrometers, 85.5 micrometers, 105.25 micrometers, 125.5 micrometers, 145.25 micrometers, 165.25 micrometers, and 187.5 micrometers.

[0028] In other embodiments, the width of the first doped region 2 accounts for 0.5-20% of the overall width. Specifically, taking an overall width of 1250 micrometers as an example, the width of the first doped region 2 can be, but is not limited to, 6.25 micrometers, 25.5 micrometers, 50.25 micrometers, 85.5 micrometers, 105.25 micrometers, 125.5 micrometers, 145.25 micrometers, 165.25 micrometers, 185 micrometers, 200 micrometers, 225 micrometers, and 250 micrometers.

[0029] In other embodiments, the width of the second doped region 4 accounts for 0.5-20% of the overall width. Specifically, taking an overall width of 1250 micrometers as an example, the width of the second doped region 4 can be, but is not limited to, 6.25 micrometers, 25.5 micrometers, 50.25 micrometers, 85.5 micrometers, 105.25 micrometers, 125.5 micrometers, 145.25 micrometers, 165.25 micrometers, 185 micrometers, 200 micrometers, 225 micrometers, and 250 micrometers.

[0030] In other embodiments, the width of the third region 5 accounts for 0.5-15% of the overall width. Specifically, taking an overall width of 1250 micrometers as an example, the width of the third region 5 can be, but is not limited to, 6.25 micrometers, 10.25 micrometers, 25.5 micrometers, 50.25 micrometers, 65.5 micrometers, 85.5 micrometers, 105.25 micrometers, 125.5 micrometers, 145.25 micrometers, 165.25 micrometers, and 187.5 micrometers.

[0031] Thus, by setting a first doped region 2 that transitions from the first region 1 to the second region 3, and a second doped region 4 that transitions from the second region 3 to the third region 5, the adhesion between the five regions and their adjacent regions is enhanced, enabling the five regions to form a stable and firm whole. This effectively solves the problem in the prior art where the frame film layer is prone to delamination or even breakage from the intermediate film layer, thereby protecting the module from moisture corrosion and extending the service life of the photovoltaic module. Both the first region 1 and the third region 5 are POE layers, the second region 3 is an EVA layer, and the first doped region 2 and the second doped region 4 are EVA / POE interdoped layers, which can achieve an optimized combination of the performance of each film layer and give full play to their respective advantages. Specifically, the first region 1 and the third region 5 can fully utilize the water-blocking properties of POE to replace butyl rubber and protect the photovoltaic module from moisture corrosion; the second region 3 can fully utilize the light transmission and bonding advantages of EVA to ensure the aging resistance and light utilization rate of the photovoltaic module; the first doped region 2 has both the same POE as the first region 1 and the same EVA as the second region 3. Utilizing the principle of good compatibility of the same materials, the first doped region 2 has excellent adhesion to both the first region 1 and the second region 3; similarly, the second doped region 4 also has excellent adhesion to both the third region 5 and the second region 3; thus, the entire encapsulant film structure has good adhesion, anti-aging properties, and water-blocking properties, meeting the comprehensive performance requirements of photovoltaic modules for encapsulant films.

[0032] Furthermore, by setting the widths of the first and third regions, as well as the proportions of the widths of the first and second doped regions within the total width of the adhesive film, the water-blocking performance of the first and third regions, and the bonding performance of the first and second doped regions, can be maximized. The POE mass fraction in the first and second doped regions decreases towards the second region, thus minimizing the amount of POE used, reducing the cost of the adhesive film, and meeting market demands. Notably, the proportion of the widths of the first and second permeable regions is significantly larger than the interface width between the edge film layer and the intermediate film layer in existing technologies. This results in a more robust and stable connection between the first water-blocking region and the bonding region via the first permeable region, and a more robust and stable connection between the second water-blocking region and the bonding region via the second permeable region, significantly enhancing aging resistance.

[0033] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transversely distributed coextruded adhesive film, characterized by: The first region, the first doped region firmly bonded with the side of the first region, the second region firmly bonded with the side of the first doped region, the second doped region firmly bonded with the side of the second region, and the third region firmly bonded with the side of the second doped region.

2. The laterally distributed coextruded film of claim 1, wherein: The first region and the third region are POE layers.

3. The laterally distributed co-extruded film according to claim 1 or 2, characterized in that: The second region is an EVA layer.

4. The laterally distributed co-extruded film of claim 3, wherein: The first doped region and the second doped region are EVA / POE doped regions.

5. The laterally distributed coextruded film of claim 4, wherein: The mass fraction of POE in the first doped region and the second doped region decreases to the second region respectively.

6. The laterally distributed coextruded film of claim 1, wherein: The adhesive film has an overall width, and the width of the first region and the third region independently accounts for 0.5-15% of the overall width.

7. The laterally distributed coextruded film of claim 6, wherein: The width of the first doped region and the second doped region independently accounts for 0.5-20% of the overall width.

8. The laterally distributed coextruded film of claim 5, wherein: The adhesive film has an overall width, and the width of the first region and the third region independently accounts for 0.5-15% of the overall width.

9. The laterally distributed co-extruded film of claim 8, wherein: The width of the first doped region and the second doped region independently accounts for 0.5-20% of the overall width.

10. The laterally distributed coextruded film of claim 1, wherein: The adhesive film has an overall width, and the width of the first doped region and the second doped region independently accounts for 0.5-20% of the overall width.

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