Color film

Abstract

The utility model relates to a color film, and the color film is characterized in that the color film comprises a base layer which is used for cutting off ultraviolet light with the wave band below 380 nm; the color layer is tightly attached to the base layer; and at least one first transparent layer, wherein the first transparent layer is tightly attached to at least one side of the color layer. The color layer has a first melt index, the first transparent layer has a second melt index, the first melt index is distributed in an increasing gradient mode towards the second melt index, and the first melt index is 1 g / 10 min. And the flatness of the color layer arranged on the surface of the base layer is enhanced. Therefore, the color film has the advantages of high light transmittance, good weather resistance, good migration resistance and the like, and the appearance color of the photovoltaic module adopting the color film is uniform and full.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaics, and in particular to a color film. BACKGROUND

[0002] Photovoltaics and buildings are two completely different industries, but after years of operation, someone tried to combine the technologies of the two originally different fields. One thing known is that photovoltaics can generate electricity through the conversion between light and electricity, the main reason being that the silicon wafer cells in photovoltaics can generate current when light passes through, and store the generated current through their own cells. The above content is originally completely unrelated to buildings, but because of the high-rise buildings in modern society, a large amount of glass curtain is used to isolate the heat energy brought by the sun, and someone thought that since glass is already used in existing photovoltaics, and glass curtain also uses a large amount of glass, why not combine the two? In this way, not only can the purpose of heat insulation be achieved, but also part of the power expenditure of the building can be saved. This concept is the embodiment of photovoltaic / building integration. This integration can be divided into two categories: one is the combination of photovoltaic array and building; the other is the integration of photovoltaic array and building.

[0003] Regardless of combination or integration, both of these two categories are to add color to the photovoltaic module to achieve the purpose of color enhancement in addition to the function of heat insulation of the building. There are many forms of implementation of the above-mentioned color adding means, such as color on the anti-reflection film of the cell, color photoelectric layer, color encapsulation adhesive film, and color front glass. Based on economic and efficiency considerations, the current commercial color crystalline silicon photovoltaic products achieve the color demand through printing coating, glass coating, etc. to obtain color front glass.

[0004] Referring to CN213660431 U (431 case), a utility model application filed by Hangzhou Fina Photovoltaic Technology Co., Ltd. on December 29, 2022. In the independent claims in this case, it can be seen that its structure includes a color layer, an upper interface bonding layer and a lower interface bonding layer, the color layer is arranged between the upper interface bonding layer and the lower interface bonding layer, and the materials of the upper interface bonding layer and the lower interface bonding layer are high molecular adhesive film materials respectively.

[0005] And in another independent right claim of this case, it can be seen that its color film includes a color layer and an upper interface bonding layer, the color layer is arranged below the upper interface bonding layer, the material of the upper interface bonding layer is a high molecular adhesive film material, the film thickness of the upper interface bonding layer is 0.45 μm-5 mm, the film thickness of the color layer is 200 nm-4 mm, and the upper interface bonding layer is transparent or translucent.

[0006] After looking at the claims of the 431 case, the detailed description in the 431 case is also carefully looked at; among them, it can be seen that the description of the color film in the detailed description of the 431 case is focused on the arrangement of the entire laminated structure, for example, the upper boundary adhesive layer can be an EVA layer or a POE layer, and the lower boundary adhesive layer can also be an EVA layer or a POE layer; and the EVA layer or the POE layer in the upper boundary adhesive layer and the lower boundary adhesive layer can be selectively provided with a crosslinking degree.

[0007] After reading the entire content of the 431 case, it can be found that there is no definition of the color layer throughout the entire content, and the material of the color layer is not explicitly described or inspired in the detailed description; therefore, without knowing the material, it can be reasonably suspected that there is a great possibility of compatibility problem between the color layer and the adhesive layer on one side, so as to possibly form a delamination situation in the subsequent process.

[0008] Through the overall arrangement of the 431 case, the material of the color layer is not seen, and there is no any motivation for the material selection of the case to enable those skilled in the art to easily think of the result of the structure after seeing the description of the 431 case. Therefore, the application is to solve this problem and proposes to solve the compatibility problem between layers.

[0009] Furthermore, since the application is to provide a color film, in order to prevent the problem of color mixing in the subsequent process, the technical key involved in the color layer is pre-crosslinked to ensure its flatness. Utility model content

[0010] In order to solve the above-mentioned prior art problems, the present application provides a color film, which has good weather resistance, high light transmittance and migration resistance, etc.

[0011] The present application provides a color film, which comprises:

[0012] A base layer can cut off ultraviolet light below 380 nm wavelength;

[0013] A color layer closely attached to the base layer; and

[0014] At least one first transparent layer, the first transparent layer is closely attached to at least one side of the color layer,

[0015] The color layer has a first melt index, the first transparent layer has a second melt index, and the first melt index is gradually distributed to the second melt index, and the first melt index is 1g / 10min.

[0016] Another object of the present application is to further comprise a second transparent layer closely adhered to one side of the base layer in a direction away from the color layer from the first transparent layer.

[0017] Another object of the present application is that the color layer has a first degree of pre-crosslinking, the first transparent layer has a second degree of pre-crosslinking, the first degree of pre-crosslinking presents a decreasing gradient distribution to the second degree of pre-crosslinking, such that the first melt index is less than the second melt index, and the second melt index is 20-25 g / 10 min.

[0018] Another object of the present application is that the color layer has a first melt index, the first transparent layer has a second melt index, the second transparent layer has a third melt index, and the first melt index presents an increasing gradient distribution to the second melt index, and the second melt index presents an increasing gradient distribution to the third melt index.

[0019] Another object of the present application is that the color layer has a first degree of pre-crosslinking, the first transparent layer has a second degree of pre-crosslinking, the second transparent layer has a third degree of pre-crosslinking and a third melt index, and the first degree of pre-crosslinking presents a decreasing gradient distribution to the second degree of pre-crosslinking, and the second degree of pre-crosslinking presents a decreasing gradient distribution to the third degree of pre-crosslinking, such that the first melt index is less than the second melt index, and the second melt index is less than the third melt index.

[0020] Another object of the present application is that the color layer has a thickness of 5 μm-150 μm.

[0021] Another object of the present application is that the color layer has a light transmittance of 50%-80%.

[0022] Another object of the present application is that the color layer has a degree of pre-crosslinking of 15%-50%.

[0023] Another object of the present application is that the base layer has a degree of pre-crosslinking of 20%-70%.

[0024] Another object of the present application is that the base layer and the first transparent layer have a degree of pre-crosslinking of <5%. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of one embodiment of the color film of the present application.

[0026] Figure 2 is a schematic diagram of another embodiment of the color film of the present application.

[0027] Figure 3 is a schematic diagram of yet another embodiment of the color film of the present application.

[0028] Reference signs: 10 - color film; 11 - base layer; 12 - color layer; 20 - first transparent layer; 30 - second transparent layer. DETAILED DESCRIPTION

[0029] The application will be further described below in conjunction with the accompanying drawings. Figures 1-2 The application will be further described below in conjunction with the accompanying drawings.

[0030] It needs to be particularly pointed out that:

[0031] EVA: the English abbreviation of ethylene-vinyl acetate copolymer;

[0032] POE: the English abbreviation of ethylene-butene copolymer or ethylene-octene copolymer;

[0033] PVB: the English abbreviation of ethylene-vinyl alcohol copolymer butyral;

[0034] VAE: the English abbreviation of vinyl acetate-ethylene copolymer.

[0035] VA content: the content of vinyl acetate in the polymer molecule.

[0036] Referring to Figure 1 As shown in the drawings, the color film 10 provided by the application comprises a base layer 11 and a color layer 12 closely attached to the base layer 11. The base layer 11 can be selected from one of EVA, POE and PVB. Any one of EVA, POE and PVB on the market exists in the form of solid. If any one of EVA, POE and PVB is used to make liquid paint, a large amount of organic solvent needs to be used, which does not meet the hard requirement of VOC emission.

[0037] Preferably, the thickness of the color layer 12 is 5 μm-150 μm. The main reason is that the color layer 12 can show saturated color as much as possible within this thickness range. Further, the light transmittance of the color layer 12 is 50%-80%.

[0038] Preferably, the pre-crosslinking degree of the color layer 12 is 20%-70% and the pre-crosslinking degree of the base layer 11 is <5%. In this way, the base layer 11 has a certain hardness, can bear the color layer 12, ensures the flatness of the color layer 12 and can avoid that the base layer 11 melts and flows to damage the flatness of the color layer 12 when the color film is applied to a photovoltaic module.

[0039] Further, as shown in the drawings, Figure 2As shown, the color film 10 provided by the present application comprises a base layer 11 and a color layer 12 closely attached to the base layer 11, and further comprises a first transparent layer 20 closely attached to at least one side of the color layer 12. Preferably, the first transparent layer 20 is closely attached to the color layer 12. The color layer 12 has a first melt index, and the first melt index is 1 g / 10 min, aiming to reduce the flowability of the color layer 12 during the lamination process. The color of the color layer 12 can be selected from any one of red, orange, yellow, green, blue, indigo, and purple. The first transparent layer 20 has a second melt index, and the second melt index is 20-25 g / 10 min. Therefore, it can be seen that the first melt index is gradually increased to the second melt index, and the first transparent layer 20 can be a POE anti-PID layer. After special formula design, the first transparent layer 20 can effectively prevent the organic pigment in the color layer and the sodium ion in the glass from being free, thereby damaging the battery sheet. In this way, the first transparent layer 20 not only enhances the adhesion of the color film, but also protects the color layer 12, and further can prevent the color layer 12 from being damaged after melting and flowing when the color film is applied to the photovoltaic module.

[0040] The reason for the gradually increasing gradient distribution of the first melt index to the second melt index is that the color layer 10 has a first pre-crosslinking degree, and the first transparent layer 20 has a second pre-crosslinking degree. The first pre-crosslinking degree is gradually decreased to the second pre-crosslinking degree, so the first melt index is less than the second melt index. The second pre-crosslinking degree is less than the first pre-crosslinking degree, which is also the reason why the first transparent layer 20 not only enhances the adhesion of the color film, but also protects the color layer 12. The principle is that the greater the pre-crosslinking degree, the smaller the melt index of the resin film, the lower the flowability, and the worse the adhesion to the glass medium. However, the color layer 12 needs to maintain its consistency at all times in any case, so the color layer 12 should not have too high flowability. Therefore, the color layer 10 including the color layer 12 and the base layer 11 carrying the color layer 12 needs to be pre-crosslinked, and the pre-crosslinking degree of the color layer 10 needs to be greater than the pre-crosslinking degree of the first transparent layer 20, i.e., the first pre-crosslinking degree is greater than the second pre-crosslinking degree. In this way, the flatness of the color layer 12 can be maintained consistently, and the color layer 12 will not be interpenetrated between layers due to melting and flowing, forming a clear wrinkle appearance, but showing a uniform and full color appearance.

[0041] Further, referring to Figure 3As shown, the color film 10 provided by the present application comprises a base layer 11 and a color layer 12 closely attached to the base layer, further comprises a first transparent layer 20 closely attached to one side of the color layer 12, and a second transparent layer 30 closely attached to the side of the color layer 10 away from the first transparent layer 20 and closely attached to one side of the base layer 11. The base layer 11 has the ability to cut off ultraviolet light, especially ultraviolet light below 380 nm, and the cut-off rate is greater than 95%. Preferably, the first transparent layer 20 is closely attached to the color layer 12, and the second transparent layer 30 is closely attached to the base layer 11. The color layer 12 has a first melt index, the first transparent layer 20 has a second melt index, and the second transparent layer 30 has a third melt index. The first melt index has an increasing gradient distribution to the second melt index, and the second melt index has an increasing gradient distribution to the third melt index. In this way, the first transparent layer 20 not only enhances the adhesion of the color film, but also protects the color layer 12 from color mixing. When the color film 10 is applied to a photovoltaic module, the color layer 12 can also prevent the flatness of the color layer 12 from being damaged after melting and flowing. At the same time, the second transparent layer 30 makes up for the lack of adhesion of the base layer 11, and further enhances the adhesion of the color film 10.

[0042] The first melt index has an increasing gradient distribution to the second melt index, and the second melt index has an increasing gradient distribution to the third melt index. Since the color layer 12 has a first pre-crosslinking degree, the first transparent layer 20 has a second pre-crosslinking degree, and the second transparent layer 30 has a third pre-crosslinking degree, the first pre-crosslinking degree has a decreasing gradient distribution to the second pre-crosslinking degree, and the second pre-crosslinking degree has a decreasing gradient distribution to the third pre-crosslinking degree. Therefore, the first melt index is less than the second melt index, and the second melt index is less than the third melt index. The fundamental principle of the first melt index being less than the second melt index is as described above, and will not be repeated here. The second melt index is less than the third melt index because the second transparent layer 30 needs to bond the photovoltaic cell. Since the roughness of the surface of the photovoltaic cell is much smaller than that of the photovoltaic glass, the photovoltaic encapsulation adhesive film is required to have a higher melt index to fully infiltrate the surface of the photovoltaic cell and ensure excellent adhesion with the photovoltaic cell. Therefore, the second melt index is less than the third melt index, and the second transparent layer 30 can more firmly bond the photovoltaic cell.

[0043] The better the adhesion of the above-mentioned color film 10 to the photovoltaic glass or photovoltaic cell, the better the aging resistance, which can ensure that the photovoltaic module using the above-mentioned color film can generate electricity for a long time and stably. Therefore, only the stacking of the layer structure cannot guarantee that the photovoltaic module can generate electricity for a long time and stably.

[0044] Further, in the above-mentioned color film, the first pre-crosslinking degree is 20%-70%. Preferably, the first pre-crosslinking degree is 30%-50%.

[0045] Further, in the above color film, the second pre-crosslinking degree is 9%-50%. Preferably, the second pre-crosslinking degree is 20%-30%.

[0046] Further, in the above color film, the first transparent layer 20 and the second transparent layer 30 are independently selected from one of EVA, POE, and PVB. Preferably, the base layer is EVA.

[0047] Further, in the above color film, the color layer thickness is 0.01mm-0.1mm. Preferably, the color layer thickness is 0.02mm-0.04mm. In this way, increasing the first transparent layer 20 and the second transparent layer 30 can also increase the overall thickness of the color film, so that the battery surface with the solder strip can be bonded, avoiding that the color film is too thin, the solder strip penetrates the color film, and causes the photovoltaic module to leak electricity and other defects.

[0048] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made on the basis of the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A color film characterized in that, The color film comprises: a base layer, which is capable of blocking ultraviolet light with a wavelength of 380 nm or less; a color layer closely attached to the base layer; and at least a first transparent layer closely attached to at least one side of the color layer, the color layer has a first melt index, the first transparent layer has a second melt index, and the first melt index is gradually increased to the second melt index, and the first melt index is 1 g / 10 min.

2. The color film of claim 1, wherein: The color film further comprises a second transparent layer closely attached to one side of the base layer in a direction away from the first transparent layer.

3. The color film of claim 2, wherein: The color layer has a first degree of pre-crosslinking, the first transparent layer has a second degree of pre-crosslinking, and the first degree of pre-crosslinking is gradually decreased to the second degree of pre-crosslinking, so that the first melt index is less than the second melt index, and the second melt index is 20-25 g / 10 min.

4. The color film of claim 3, wherein: The color layer has a first melt index, the first transparent layer has a second melt index, and the second transparent layer has a third melt index, and the first melt index is gradually increased to the second melt index, and the second melt index is gradually increased to the third melt index.

5. The color film of claim 3, wherein: The color layer has a first degree of pre-crosslinking, the first transparent layer has a second degree of pre-crosslinking, and the second transparent layer has a third degree of pre-crosslinking and a third melt index, and the first degree of pre-crosslinking is gradually decreased to the second degree of pre-crosslinking, and the second degree of pre-crosslinking is gradually decreased to the third degree of pre-crosslinking, so that the first melt index is less than the second melt index, and the second melt index is less than the third melt index.

6. The color film according to any one of claims 1-5, wherein: the color layer has a thickness of 5 μm-150 μm.

7. The color film of claim 6, wherein: the color layer has a light transmittance of 50%-80%.

8. The color film of claim 6, wherein: the color layer has a degree of pre-crosslinking of 20%-70%.

9. The color film according to any one of claims 1-5, wherein: the color layer has a degree of pre-crosslinking of 20%-70%.

10. The color film according to any one of claims 1-5, wherein: the base layer and the first transparent layer have a degree of pre-crosslinking of <5%.

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