Anti-wrinkle colored EPE adhesive film, preparation method thereof and photovoltaic module

Abstract

The invention belongs to the technical field of photovoltaic packaging materials, and particularly relates to an anti-wrinkle colored EPE adhesive film, a preparation method thereof and a photovoltaic module, and the anti-wrinkle colored EPE adhesive film comprises a POE layer located in the middle and EVA layers arranged on the two sides of the POE layer; the colored EPE adhesive film is subjected to electron beam irradiation treatment, and in the single-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 28%-48%, the vulcanization ML value of the EVA layer is 0.28-0.35, the pre-crosslinking degree of the POE layer is 0.5%-5%, and the vulcanization ML value of the POE layer is 0.30-0.37; in the double-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 15%-35%, the vulcanization ML value of the EVA layer is 0.26-0.32, the pre-crosslinking degree of the POE layer is 0.5%-5%, and the vulcanization ML value of the POE layer is 0.28-0.34.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic encapsulation materials technology, specifically relating to an anti-wrinkle colored EPE film and its preparation method, and a photovoltaic module. Background Technology

[0002] Building-integrated photovoltaics (BIPV) is a technology that integrates solar modules into buildings. Besides power generation, BIPV modules also need to function as building materials and enhance aesthetics, representing an inevitable trend in solar energy development. Coloring photovoltaic modules is one of the core technologies of BIPV. Furthermore, in Europe and America, building roofs are typically black, brick red, or gray; for visual appeal, they desire that the photovoltaic modules used on the roofs also match the roof's color.

[0003] In recent years, many photovoltaic glass manufacturers have been coating glass surfaces with various colored glazes or printing ink patterns onto the glass surface. However, this method is not only costly but also results in low light transmittance, leading to lower photoelectric conversion efficiency and thus affecting the power generation efficiency of the modules. How to make solar modules display bright colors while maintaining high light transmittance without compromising photoelectric conversion efficiency has become a key technology that must be overcome for large-scale BIPV applications. Therefore, colored encapsulated films have a promising market prospect, as their light transmittance in the 380–1100nm wavelength range is not only higher than that of colored tempered glass, but their cost is also much lower than the 80-100 RMB / m² price of colored glass.

[0004] Transparent EPE film has been widely used due to its superior anti-PID performance and lower cost. However, due to the difference in flowability between EVA layer and POE layer after irradiation treatment, transparent EPE film without obvious appearance differences will have a large number of wrinkles longer than 30cm after adding color powder, which makes the appearance of the colored photovoltaic module lamination judged as defective.

[0005] Therefore, how to overcome the wrinkling defects that occur in colored EPE films after lamination is a technical problem that urgently needs to be solved in this field.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0007] This disclosure provides at least one anti-wrinkle colored EPE film, its preparation method, and a photovoltaic module.

[0008] In a first aspect, embodiments of this disclosure provide a colored EPE film, comprising: a POE layer located in the middle and EVA layers disposed on both sides of the POE layer; the colored EPE film is treated by electron beam irradiation, and in a single-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 28% to 48%, the vulcanization ML value is 0.28 to 0.35, the pre-crosslinking degree of the POE layer is 0.5% to 5%, and the vulcanization ML value is 0.30 to 0.37; in a double-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 15% to 35%, the vulcanization ML value is 0.26 to 0.32, the pre-crosslinking degree of the POE layer is 0.5% to 5%, and the vulcanization ML value is 0.28 to 0.34.

[0009] In one optional embodiment, the EVA layer and / or the POE layer includes color masterbatch; wherein, by mass parts, every 100 parts of EVA layer includes 2 to 6 parts of color masterbatch, and every 100 parts of POE layer includes 2 to 6 parts of color masterbatch; or the POE layer does not contain color masterbatch, and every 100 parts of EVA layer includes 3 to 9 parts of color masterbatch; or the EVA layer does not contain color masterbatch, and every 100 parts of POE layer includes 4 to 12 parts of color masterbatch.

[0010] In one optional embodiment, the color masterbatch comprises 5 to 30 parts of color powder per 100 parts by weight.

[0011] In one alternative embodiment, the pigment includes any one or more combinations of metal oxides, sulfides, photonic crystals, and pearlescent powders.

[0012] In one optional embodiment, each 100 parts by weight of EVA layer further includes the following components: 0.5-1.5 parts initiator, 0.5-1.5 parts co-crosslinking agent, 0.1-1 part coupling agent, 0.1-0.5 parts antioxidant, and 0.1-0.5 parts light stabilizer; and each 100 parts by weight of POE layer further includes the following components: 0.5-1.5 parts co-crosslinking agent, 0.1-0.5 parts antioxidant, and 0.1-0.5 parts light stabilizer.

[0013] In one optional embodiment, the VA content in the EVA layer is 27-30 wt%; and the octene content in the POE layer is 20-35 wt%.

[0014] In one optional embodiment, the thickness ratio of the three layers in the EPE film is 1:2:1 to 2:1:2.

[0015] Secondly, this disclosure also provides a method for preparing a colored EPE film as described above, comprising the following steps: S1, preparing raw materials for EVA layer and POE layer; S2, preheating and mixing, standing, melt blending, co-extrusion casting, traction compounding, and stretching the raw materials for EVA layer and POE layer respectively to form a layered EPE film; S3, subjecting the EPE film obtained in S2 to electron beam irradiation treatment, with an irradiation velocity-to-flow ratio of 0.7:1 to 1.5:1, to adjust the pre-crosslinking degree and vulcanization ML value of each layer to obtain a colored EPE film.

[0016] Thirdly, this disclosure also provides a single-glass photovoltaic module, including a colored EPE encapsulant film; wherein the colored EPE encapsulant film is treated by electron beam irradiation, and the pre-crosslinking degree of the EVA layer of the colored EPE encapsulant film is 28% to 48%, the vulcanization ML value is 0.28 to 0.35, the pre-crosslinking degree of the POE layer of the colored EPE encapsulant film is 0.5% to 5%, and the vulcanization ML value is 0.30 to 0.37.

[0017] Fourthly, this disclosure also provides a double-glass photovoltaic module, including a colored EPE encapsulant film; wherein the colored EPE encapsulant film is treated with electron beam irradiation, and the pre-crosslinking degree of the EVA layer of the colored EPE encapsulant film is 15% to 35%, the vulcanization ML value is 0.26 to 0.32, the pre-crosslinking degree of the POE layer of the colored EPE encapsulant film is 0.5% to 5%, and the vulcanization ML value is 0.28 to 0.34.

[0018] The beneficial effects of this invention are that the anti-wrinkle colored EPE film and its preparation method, as well as the photovoltaic module, improve the interlayer flowability difference by subjecting the colored EPE film to electron beam irradiation treatment and ensuring that the pre-crosslinking degree and vulcanization ML value of each layer meet a specific range. This overcomes the wrinkles caused by lamination after adding color powder to the EPE film, enabling the colored EPE film to be used as a positive film in single-glass and double-glass modules, greatly enhancing the aesthetic appeal of the colored module.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 An appearance view of the laminate of the silver-white colored adhesive film provided in Embodiment 1 of this disclosure; Figure 2 An appearance view of the laminate of the silver-white colored adhesive film provided in Embodiment 2 of this disclosure; Figure 3 An appearance view of the laminate of the silver-white colored adhesive film provided in Embodiment 3 of this disclosure; Figure 4 An appearance view of the laminate of the silver-white colored adhesive film provided in Embodiment 3 of this disclosure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0025] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0026] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0027] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] Conventional methods for improving wrinkles in transparent films mainly involve increasing crosslinking density, heat treatment during extrusion molding, and introducing suitable fillers or chemical modifications to increase the modulus of the polymer material.

[0029] After irradiation treatment, the pre-crosslinking of colored films is improved. Although this can slightly increase the modulus, it has limited effect on improving the wrinkles in the laminated appearance. Because of the introduction of pigments, even a small wrinkle will be very obvious. The problem cannot be solved by conventional transparent film methods alone.

[0030] This disclosure provides a colored EPE film, comprising: a POE layer located in the middle and EVA layers disposed on both sides of the POE layer; the colored EPE film is treated with electron beam irradiation, and in a single-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 28% to 48%, and the vulcanization ML value is 0.28 to 0.35, the pre-crosslinking degree of the POE layer is 0.5% to 5%, and the vulcanization ML value is 0.30 to 0.37; in a double-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 15% to 35%, and the vulcanization ML value is 0.26 to 0.32, the pre-crosslinking degree of the POE layer is 0.5% to 5%, and the vulcanization ML value is 0.28 to 0.34.

[0031] Specifically, the main purpose of irradiation treatment is to reduce the flowability between EVA and POE layers. POE has better flowability than EVA. Therefore, by controlling the thickness ratio of EVA and POE layers and then performing irradiation treatment to control the ML value and pre-crosslinking degree of the EVA and POE layers, the flowability of these two materials is not only reduced but also made similar, which is a key factor in solving the wrinkling problem in colored films. This similar flowability also greatly improves the problem of pigment accumulation and disordered agglomeration caused by the flowability difference between EVA and POE layers during the lamination process.

[0032] In some embodiments, specifically, the EVA layer and / or the POE layer includes color masterbatch; wherein, by mass parts, every 100 parts of EVA layer includes 2 to 6 parts of color masterbatch, and every 100 parts of POE layer includes 2 to 6 parts of color masterbatch; or the POE layer does not contain color masterbatch, and every 100 parts of EVA layer includes 3 to 9 parts of color masterbatch; or the EVA layer does not contain color masterbatch, and every 100 parts of POE layer includes 4 to 12 parts of color masterbatch.

[0033] In some embodiments, specifically, the color masterbatch comprises 5 to 30 parts of color powder per 100 parts by weight.

[0034] In some embodiments, specifically, the colorant includes any one or more combinations of metal oxides, sulfides, photonic crystals, and pearlescent powders.

[0035] In some embodiments, specifically, every 100 parts by weight of EVA layer further includes the following components: 0.5 to 1.5 parts of initiator, 0.5 to 1.5 parts of co-crosslinking agent, 0.1 to 1 part of coupling agent, 0.1 to 0.5 parts of antioxidant, and 0.1 to 0.5 parts of light stabilizer; every 100 parts by weight of POE layer further includes the following components: 0.5 to 1.5 parts of co-crosslinking agent, 0.1 to 0.5 parts of antioxidant, and 0.1 to 0.5 parts of light stabilizer.

[0036] In some embodiments, specifically, the VA content in the EVA layer is 27-30 wt%; and the octene content in the POE layer is 20-35 wt%.

[0037] In some embodiments, specifically, the thickness ratio of the three layers in the EPE film is 1:2:1 to 2:1:2.

[0038] This disclosure also provides a method for preparing a colored EPE film as described above, comprising the following steps: S1, preparing raw materials for EVA layer and POE layer; S2, preheating and mixing, allowing to stand, melt blending, co-extruding and casting, traction compounding, and stretching the raw materials for EVA layer and POE layer respectively to form a layered EPE film; S3, subjecting the EPE film obtained in S2 to electron beam irradiation treatment, with an irradiation velocity-to-flow ratio of 0.7:1 to 1.5:1, to adjust the pre-crosslinking degree and vulcanization ML value of each layer to obtain a colored EPE film.

[0039] This disclosure also provides a single-glass photovoltaic module, including a colored EPE encapsulant film; wherein the colored EPE encapsulant film is treated with electron beam irradiation, and the pre-crosslinking degree of the EVA layer of the colored EPE encapsulant film is 28% to 48%, the vulcanization ML value is 0.28 to 0.35, the pre-crosslinking degree of the POE layer of the colored EPE encapsulant film is 0.5% to 5%, and the vulcanization ML value is 0.30 to 0.37.

[0040] This disclosure also provides a double-glass photovoltaic module, including a colored EPE film; wherein the colored EPE film is treated with electron beam irradiation, and the pre-crosslinking degree of the EVA layer of the colored EPE film is 15% to 35%, the vulcanization ML value is 0.26 to 0.32, the pre-crosslinking degree of the POE layer of the colored EPE film is 0.5% to 5%, and the vulcanization ML value is 0.28 to 0.34.

[0041] In Example 1, EVA and POE were added to the required additives and color masterbatch, respectively, and placed in a mixer. EVA was mixed at 40℃–50℃ for 80–100 min and then allowed to stand for 12–15 h. POE was stirred at 40–50℃ for 135–150 min and then placed in a 50℃ oven for 9–12 h. Afterwards, the EVA and POE raw materials were placed in two twin-screw extruders for melt blending. The mixture was then simultaneously extruded through the co-extrusion casting die of the extruders, pulled, laminated, and stretched into a film to form a layered EPE encapsulating film. Subsequently, several different thickness ratios of EPE were extruded, ranging from 1:2:1 to 2:1:2, with color masterbatch added to both EVA and POE layers, only the EVA layer, or only the POE layer.

[0042] EPE films extruded using different methods were subjected to irradiation pretreatment at a linear velocity of 30 m / s and an irradiation velocity-to-flow ratio between 0.7:1 and 1.5:1. After irradiation, the EPE films were soaked in petroleum ether for 1 min to separate the three layers, and the ML value and pre-crosslinking value of the EVA layer and EPE layer were tested separately.

[0043] For single-glass modules, a colored film measuring 1128mm×2376mm is used as the front film. It is laid between 1128mm×2376mm photovoltaic tempered glass and a white backsheet. The backsheet uses a treated high-reflectivity black film. TOPCON or BC cells are then laid between the colored film and the high-reflectivity black film. After lamination, the module is placed in a dual-chamber laminator for lamination. The temperature and pressure of the first and second chambers of the dual-chamber laminator are adjusted. After lamination for about 20 minutes, the module is cooled and placed under sunlight to observe the appearance of wrinkles.

[0044] For double-glass modules, a color film measuring 1128mm×2376mm is used as the front film and is laid between two layers of 1128mm×2376mm photovoltaic tempered glass. The back film uses a treated high-reflectivity black film, and TOPCON or BC cells are laid between the color film and the high-reflectivity black film. Then, it is placed in a dual-cavity laminator for lamination. The temperature and pressure of the first and second cavities of the dual-cavity laminator are adjusted. After lamination for about 20 minutes, it is cooled and placed under sunlight to observe the appearance of wrinkles.

[0045] Example 2: 0.7 parts initiator, 0.5 parts co-crosslinking agent, 0.5 parts coupling agent, 0.2 parts antioxidant, 0.2 parts light stabilizer, and 5 parts color masterbatch were added to 100 parts of EVA and set aside for use.

[0046] Add 0.9 parts initiator, 1 part co-crosslinking agent, 0.2 parts antioxidant, 0.2 parts light stabilizer, and 5 parts color masterbatch to 100 parts of POE and set aside for later use.

[0047] EVA and POE were added to the required additives and color masterbatch, respectively, and placed in a mixer. EVA was mixed at 50°C for 100 minutes and then allowed to stand for 12 hours. POE was stirred at 50°C for 135 minutes and then placed in a 50°C oven to stand for 12 hours. Afterwards, the EVA and POE raw materials were placed in two twin-screw extruders for melt blending. The materials were then simultaneously discharged through the co-extrusion casting die of the extruders, drawn together, and stretched into a film to form a layered structure film EPE for encapsulation. The EVA layer thickness: POE layer thickness: EVA layer thickness were calculated in ratios of 1:2:1, 1:1:1, and 2:1:2. Examples 1, 2, and 3 were created when color masterbatch was added to both the EVA and POE layers, respectively. Examples 4, 5, and 6 were created when color masterbatch was added to the EVA layer and not to the POE layer. Examples 7, 8, and 9 were created when color masterbatch was added to the POE layer and not to the EVA layer.

[0048] The colored EPE films from Examples 1-9 were subjected to irradiation pretreatment at a linear velocity of 30 m / s and velocity-to-flow ratios of 0.7:1, 1.0:1, 1.3:1, and 1.5:1, respectively. After treatment, the colored EPE was soaked in petroleum ether for 1 min to separate the three layers, and the ML value and pre-crosslinking value of the EVA layer and EPE layer were tested separately.

[0049] For single-glass modules, the irradiated colored EPE film from Examples 1-9 is cut into 1128mm×2376mm pieces and laid between 1128mm×2376mm photovoltaic tempered glass and a white backsheet. The backsheet uses a treated high-reflectivity black film, and TOPCON or BC cells are laid between the colored film and the high-reflectivity black film. Then, it is placed in a dual-chamber laminator for lamination. The temperature and pressure of the first and second chambers of the dual-chamber laminator are adjusted. After lamination for about 20 minutes, it is cooled and placed under sunlight to observe the appearance of wrinkles.

[0050] For double-glass modules, the irradiated colored EPE films from Examples 1-9 are cut into 1128mm×2376mm pieces and laid between two layers of 1128mm×2376mm photovoltaic tempered glass. The backsheet uses a treated high-reflectivity black film, and PERC, TOPCON, or BC cells are laid between the colored film and the high-reflectivity black film. Then, the modules are placed in a dual-chamber laminator for lamination. The temperature and pressure of the first and second chambers of the dual-chamber laminator are adjusted. After lamination for about 20 minutes, the modules are cooled and placed under sunlight to observe the appearance and wrinkles.

[0051] Specifically, the results obtained by the colored EPE films described in Examples 1 to 9 under electron beam irradiation with velocity-to-flow ratios of 0.7:1, 1.0:1, 1.3:1 and 1.5:1 are shown in Tables 1 to 4 below.

[0052] Table 1 Velocity-to-flow ratio 0.7:1 ML EVA layer ML POE layer Pre-crosslinked EVA layer Pre-crosslinked POE layer Single-glass pleats Double glass pleats Example 1 0.28 / 0.27 0.18 / 0.17 29.31% 0.43% ≥5 pieces, length > 30cm ≥4 strips with a length > 20cm Example 4 0.29 / 0.27 0.19 / 0.18 28.60% 0.41% ≥5 pieces, length > 30cm ≥4 strips with a length > 20cm Example 7 0.28 / 0.28 0.18 / 0.18 30.11% 0.33% ≥5 pieces, length > 30cm ≥4 strips with a length > 20cm Example 2 0.27 / 0.26 0.22 / 0.21 26.43% 0.41% ≥5 pieces, length > 30cm ≥3 strips with a length > 20cm Example 5 0.25 / 0.25 0.23 / 0.22 24.11% 0.29% ≥5 pieces, length > 30cm ≥3 pieces with a length > 20cm Example 8 0.25 / 0.24 0.21 / 0.21 25.69% 0.31% ≥5 pieces, length > 30cm ≥3 strips with a length > 20cm Example 3 0.23 / 0.24 0.23 / 0.22 22.13% 0.51% ≥3 strips with a length > 20cm ≥3 strips with a length > 20cm Example 6 0.25 / 0.23 0.24 / 0.21 21.41% 0.63% ≥3 strips with a length > 20cm ≥3 strips with a length > 20cm Example 9 0.24 / 0.24 0.23 / 0.23 22.89% 0.71% ≥3 strips with a length > 20cm ≥3 strips with a length > 20cm Table 2 Velocity-to-flow ratio 1.0:1 ML EVA layer ML POE layer Pre-crosslinked EVA layer Pre-crosslinked POE layer Single-glass pleats Double glass pleats Example 1 0.33 / 0.34 0.21 / 0.20 35.66% 0.81% ≥4 strips with a length >10cm ≥4 strips with a length >10cm Example 4 0.32 / 0.34 0.22 / 0.22 37.12% 0.73% ≥4 strips with a length >10cm ≥4 strips with a length >10cm Example 7 0.33 / 0.33 0.20 / 0.22 36.93% 0.75% ≥4 strips with a length >10cm ≥4 strips with a length >10cm Example 2 0.30 / 0.31 0.24 / 0.26 32.11% 0.82% ≥3 pieces with a length >10cm ≤2 pieces, length >3cm Example 5 0.32 / 0.31 0.25 / 0.25 31.78% 0.86% ≥3 pieces with a length >10cm ≤2 pieces, length >3cm Example 8 0.31 / 0.31 0.26 / 0.25 33.91% 0.89% ≥3 pieces with a length >10cm ≤2 pieces, length >3cm Example 3 0.28 / 0.29 0.28 / 0.28 29.11% 1.03% ≤1 piece with a length >5cm No wrinkles Example 6 0.29 / 0.30 0.29 / 0.28 28.13% 0.99% ≤1 piece with a length >5cm No wrinkles Example 9 0.28 / 0.28 0.29 / 0.29 30.99% 1.09% ≤1 piece with a length >5cm No wrinkles Table 3 Velocity-to-flow ratio 1.3:1 MLEVA layer MLPOE layer Pre-crosslinked EVA layer Pre-crosslinked POE layer Single-glass pleats Double glass pleats Example 1 0.38 / 0.39 0.25 / 0.24 41.56% 0.97% ≥3 pieces with a length >10cm ≥3 pieces with a length >10cm Example 4 0.37 / 0.38 0.25 / 0.25 40.91% 1.11% ≥3 pieces with a length >10cm ≥3 pieces with a length >10cm Example 7 0.38 / 0.40 0.24 / 0.25 42.11% 0.92% ≥3 pieces with a length >10cm ≥3 pieces with a length >10cm Example 2 0.34 / 0.32 0.28 / 0.29 36.19% 1.03% ≤2 pieces, length <3cm ≥2 pieces with a length >3cm Example 5 0.33 / 0.33 0.27 / 0.29 35.89% 1.12% ≤2 pieces, length <3cm ≥2 pieces with a length >3cm Example 8 0.33 / 0.34 0.28 / 0.27 36.72% 1.08% ≤2 pieces, length <3cm ≥2 pieces with a length >3cm Example 3 0.31 / 0.30 0.30 / 0.32 32.33% 1.53% No wrinkles No wrinkles Example 6 0.32 / 0.30 0.32 / 0.32 33.57% 1.47% No wrinkles No wrinkles Example 9 0.31 / 0.31 0.31 / 0.30 33.15% 1.33% No wrinkles No wrinkles Table 4 Velocity-to-flow ratio 1.5:1 MLEVA layer MLPOE layer Pre-crosslinked EVA layer Pre-crosslinked POE layer Single-glass pleats Double glass pleats Example 1 0.43 / 0.42 0.28 / 0.27 44.31% 0.99% ≥5 strips, length <5cm ≥5 pieces, length <3cm Example 4 0.44 / 0.44 0.26 / 0.28 41.21% 0.92% ≥5 strips, length <5cm ≥5 pieces, length <3cm Example 7 0.45 / 0.43 0.28 / 0.26 45.98% 1.19% ≥5 strips, length <5cm ≥5 pieces, length <3cm Example 2 0.39 / 0.40 0.31 / 0.30 43.19% 1.01% ≥4 strips with a length <5cm ≥3 pieces with a length <3cm Example 5 0.38 / 0.38 0.32 / 0.30 42.11% 0.90% ≥4 strips with a length <5cm ≥3 pieces with a length <3cm Example 8 0.40 / 0.39 0.31 / 0.29 44.53% 0.89% ≥4 strips with a length <5cm ≥3 pieces with a length <3cm Example 3 0.36 / 0.34 0.37 / 0.35 38.67% 1.67% No wrinkles ≤1 piece with a length <3cm Example 6 0.35 / 0.35 0.34 / 0.36 39.18% 1.34% No wrinkles ≤1 piece with a length <3cm Example 9 0.35 / 0.35 0.36 / 0 / 35 40.11% 1.22% No wrinkles ≤1 piece with a length <3cm Specifically, as shown in the table, the pre-crosslinking degree and vulcanization ML value of the EVA and POE layers play a decisive role in suppressing wrinkles. Under the condition that the parameters of the EVA and POE layers meet the constraints, the interlayer flowability difference will be effectively controlled, and the wrinkle problem will be significantly reduced.

[0053] Besides this, the most significant factor affecting wrinkles is the thickness ratio of the EVA layer to the POE layer; please refer to [link / reference]. Figure 1 , Figure 1The colored EPE film obtained in Example 1 showed numerous wrinkles; please refer to [link / reference]. Figure 2 , Figure 2 The wrinkles in the colored EPE film obtained in Example 2 were slightly improved. Please refer to [link / reference]. Figure 3 and Figure 4 In Examples 3, 6, and 9, the thickness ratio is 2:1:2. Under this preferred embodiment, the laminate has almost zero wrinkles.

[0054] Meanwhile, although pigments can cause wrinkles, once the issue of the difference in flowability between the EVA and POE layers is improved, adding masterbatch alone to the EVA or POE layer has no effect on the appearance of wrinkles in the laminate.

[0055] In summary, this anti-wrinkle colored EPE film and its preparation method, as well as the photovoltaic module, improve the interlayer flowability difference by subjecting the colored EPE film to electron beam irradiation treatment and ensuring that the pre-crosslinking degree and vulcanization ML value of each layer meet a specific range. This overcomes the wrinkles caused by lamination after adding color powder to the EPE film, enabling the colored EPE film to be used as a positive film in single-glass and double-glass modules, greatly enhancing the aesthetic appeal of the colored modules.

[0056] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A colored EPE film, characterized in that, include: The POE layer is located in the middle and the EVA layers are disposed on both sides of the POE layer; The colored EPE film is treated with electron beam irradiation, and In a single-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 28%–48%, and the sulfurization ML value is 0.28–0.35; the pre-crosslinking degree of the POE layer is 0.5%–5%, and the sulfurization ML value is 0.30–0.

37. In the double-glass photovoltaic module, the pre-crosslinking degree of the EVA layer is 15% to 35%, and the sulfurization ML value is 0.26 to 0.32; the pre-crosslinking degree of the POE layer is 0.5% to 5%, and the sulfurization ML value is 0.28 to 0.

34.

2. The colored EPE film as described in claim 1, characterized in that, The EVA layer and / or the POE layer include color masterbatch; Of which, by weight, every 100 parts of EVA layer includes 2 to 6 parts of color masterbatch, and every 100 parts of POE layer includes 2 to 6 parts of color masterbatch; or The POE layer does not contain color masterbatch, and each 100 parts of EVA layer includes 3 to 9 parts of color masterbatch; or The EVA layer does not contain color masterbatch, and each 100 parts of POE layer includes 4 to 12 parts of color masterbatch.

3. The colored EPE film as described in claim 2, characterized in that, The color masterbatch contains 5 to 30 parts of color powder per 100 parts by weight.

4. The colored EPE film as described in claim 3, characterized in that, The pigments include any one or more combinations of metal oxides, sulfides, photonic crystals, and pearlescent powders.

5. The colored EPE film as described in claim 2, characterized in that, The EVA layer, by weight, also includes the following components per 100 parts: initiator 0.5-1.5 parts, co-crosslinking agent 0.5-1.5 parts, coupling agent 0.1-1 part, antioxidant 0.1-0.5 parts, and light stabilizer 0.1-0.5 parts; The POE layer also includes the following components per 100 parts by weight: 0.5 to 1.5 parts of crosslinking agent, 0.1 to 0.5 parts of antioxidant, and 0.1 to 0.5 parts of light stabilizer.

6. The colored EPE film as described in claim 1, characterized in that, The VA content in the EVA layer is 27-30 wt%; The octene content in the POE layer is 20–35 wt%.

7. The colored EPE film as described in claim 1, characterized in that, The thickness ratio of the three layers in the EPE film is 1:2:1 to 2:1:

2.

8. A method for preparing a colored EPE film as described in any one of claims 1-7, characterized in that, Includes the following steps: S1, raw materials for configuring EVA and POE layers; S2, the raw materials of EVA layer and POE layer are preheated and mixed, allowed to stand, melt-blended, co-extruded and cast, drawn and compounded, and stretched into film to form a layered EPE film. S3. The EPE film obtained in S2 is subjected to electron beam irradiation treatment with an irradiation velocity-to-flow ratio of 0.7:1 to 1.5:1 to adjust the pre-crosslinking degree and vulcanization ML value of each layer, thereby obtaining a colored EPE film.

9. A single-glass photovoltaic module, characterized in that, Including colored EPE film; The colored EPE film is treated with electron beam irradiation, and The pre-crosslinking degree of the EVA layer of the colored EPE film is 28% to 48%, and the vulcanization ML value is 0.28 to 0.

35. The pre-crosslinking degree of the POE layer of the colored EPE film is 0.5% to 5%, and the vulcanization ML value is 0.30 to 0.

37.

10. A double-glass photovoltaic module, characterized in that, Including colored EPE film; The colored EPE film is treated with electron beam irradiation, and The pre-crosslinking degree of the EVA layer of the colored EPE film is 15% to 35%, and the vulcanization ML value is 0.26 to 0.

32. The pre-crosslinking degree of the POE layer of the colored EPE film is 0.5% to 5%, and the vulcanization ML value is 0.28 to 0.34.

Images