A reflective film

Abstract

The present application provides a reflective film, which includes an adhesive film layer, a reflective microstructure layer, and a base film layer arranged therebetween. The base film layer includes polyester film and mica. Mica is added to the base film layer in proportion. When sunlight irradiates the reflective film, within the ultraviolet range of 200 to 350 nm, the reflectivity of the composition of the polyester film and mica to ultraviolet rays is less than 5%, and the absorption rate is higher than 95%, thereby shielding ultraviolet rays, avoiding the adverse effects of the reflective film being irradiated by sunlight for a long time, and increasing the service life of the reflective film.

Description

Technical Field

[0001] The present application relates to the technical field of reflective materials, and in particular to a reflective film. Background Art

[0002] Currently, researchers are committed to efficiently converting solar energy into electrical energy. In order to make full use of the effective use area in photovoltaic modules, researchers have conducted detailed analysis and research on the non-battery areas in photovoltaic modules and found that most of the light incident on the gaps between the cells in the photovoltaic modules is directly reflected and reflected to the outside of the photovoltaic module or reaches the ground through the photovoltaic module. Since there are gaps between the cells and between the cell strings in the photovoltaic module, these gaps actually occupy the surface area of ​​the photovoltaic module but do not participate in energy conversion, so that the sunlight received by this part of the gap is wasted, which in turn reduces the effective power generation area of ​​a single photovoltaic module, which is not conducive to improving the utilization rate of light.

[0003] In order to improve the utilization rate of light and reduce the impact of non-cell areas on the output power of solar cells, the prior art directly or indirectly sets a reflective film structure on the photovoltaic welding strip on the surface of the cell in the photovoltaic module to reflect the light incident on the surface of the photovoltaic welding strip to other positions of the cell surface for absorption.

[0004] The reflective film in the prior art is made of polyester film, which has poor UV protection effect and is prone to yellowing, resulting in reduced light transmittance, which is not conducive to improving the utilization rate of light; at the same time, the reflective film is exposed to sunlight for a long time, which will reduce the service life of the reflective film, increase the frequency of replacing the reflective film, and increase the production cost.

[0005] Therefore, how to design a reflective film that can effectively block ultraviolet rays is an urgent problem that needs to be solved by those skilled in the art. Summary of the invention

[0006] The present application provides a reflective film, which has good UV protection properties, avoids the adverse effects of exposure to sunlight on the reflective film, and increases the service life of the reflective film.

[0007] This application provides the following solutions:

[0008] The present application provides a reflective film, comprising:

[0009] An adhesive film layer, a reflective microstructure layer, and a base film layer disposed between the adhesive film layer and the reflective microstructure layer;

[0010] The components of the base film layer include polyester film and mica;

[0011] The mass ratio of polyester film to mica is 100:30 to 100:250;

[0012] The mass ratio of the polyester film to the base film layer is 10:100 to 60:100;

[0013] The mass ratio of mica to the base film layer is 30:100 to 70:100.

[0014] Optionally, the mica is muscovite and / or sericite.

[0015] Preferably, the mass ratio of polyester film to mica is 100:50;

[0016] or,

[0017] The mass ratio of polyester film to mica is 100:100;

[0018] or,

[0019] The mass ratio of polyester film to mica is 100:200.

[0020] Specifically, the components of the polyester film include polyethylene terephthalate and additives.

[0021] Optionally, the additive includes at least one of aminopropyltriethoxysilane, white oil, EPDM rubber, vinyl bisstearamide and carbodiimide.

[0022] Preferably, the reflective film further comprises a UV-resistant coating;

[0023] The UV-resistant coating is arranged between the adhesive film layer and the base film layer.

[0024] The UV-resistant coating is disposed between the base film layer and the reflective microstructure layer.

[0025] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0026] The present application provides a reflective film, which includes an adhesive film layer, a reflective microstructure layer, and a base film layer arranged therebetween. The base film layer includes polyester film and mica. Mica is added to the base film layer in proportion. When sunlight irradiates the reflective film, within the ultraviolet range of 200 to 350 nm, the reflectivity of the composition of the polyester film and mica to ultraviolet rays is less than 5%, and the absorption rate is higher than 95%, thereby shielding ultraviolet rays, avoiding the adverse effects of the reflective film being irradiated by sunlight for a long time, and increasing the service life of the reflective film.

[0027] Preferably, the mica can be sericite, which belongs to the monoclinic system, has a high aspect ratio, and has a better UV shielding effect than inorganic mineral fillers. At the same time, sericite contains 50 to 100 layers of crystal water, the refractive index of which is 1.33, and the refractive effect is strong; sericite has a composite structure layer with an interlayer spacing of about It is relatively close to the wavelength of ultraviolet light and microwaves; when the colored light passes through the composite structure layer, it will be subjected to dozens of continuous refractions and reflections, as well as hue interference between multiple colored lights, which will lead to shielding and extinction. Therefore, sericite has a good ultraviolet shielding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is the reflectivity of the polyester film, sericite and the combination of polyester film and sericite provided in the embodiments of the present application at different wavelengths. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of the present application.

[0031] As described in the background technology, the reflective film in the prior art is made of polyester film, which has a poor UV protection effect and is prone to yellowing, resulting in reduced light transmittance, which is not conducive to improving the utilization rate of light; at the same time, the reflective film is exposed to sunlight for a long time, which will reduce the service life of the reflective film, increase the frequency of replacing the reflective film, and lead to an increase in production costs.

[0032] In order to solve one or more of the above problems, the present application provides a reflective film, which includes an adhesive film layer, a reflective microstructure layer, and a base film layer arranged therebetween. The base film layer includes polyester film and mica. Mica is added to the base film layer in proportion. When sunlight irradiates the reflective film, within the ultraviolet range of 200 to 350 nm, the reflectivity of the composition of the polyester film and mica to ultraviolet rays is less than 5%, and the absorption rate is higher than 95%, thereby shielding ultraviolet rays, avoiding the adverse effects of long-term exposure of the reflective film to sunlight, and increasing the service life of the reflective film.

[0033] The following are optional technical solutions for this application, but are not intended to limit the technical solutions provided in this application. Through the following optional technical solutions, the technical objectives and beneficial effects of this application can be better achieved and realized.

[0034] The present application provides a reflective film, comprising: an adhesive film layer, a reflective microstructure layer, and a base film layer arranged between the adhesive film layer and the reflective microstructure layer; components of the base film layer include polyester film and mica; the mass ratio of the polyester film to the mica is 100:30 to 100:250; the mass ratio of the polyester film to the base film layer is 10:100 to 60:100; the mass ratio of mica to the base film layer is 30:100 to 70:100.

[0035] Among them, when sunlight irradiates on the reflective film, the combination of polyester film and mica has a good ultraviolet protection effect in the ultraviolet range of 200 to 350nm.

[0036] Preferably, the mass ratio of the polyester film to the mica is 100:50.

[0037] Preferably, the mass ratio of the polyester film to the mica is 100:100.

[0038] Preferably, the mass ratio of the polyester film to the mica is 100:200.

[0039] Optionally, the mica is muscovite and / or sericite.

[0040] Among them, both muscovite and sericite have high UV resistance; comparing the performance of the two in terms of structure, construction and chemical composition, sericite has better UV resistance.

[0041] Specifically, the components of the polyester film include polyethylene terephthalate and additives.

[0042] Optionally, the additive includes at least one of aminopropyltriethoxysilane, white oil, EPDM rubber, vinyl bisstearamide and carbodiimide.

[0043] Among them, polyethylene terephthalate is used as the main component of polyester film; aminopropyl triethoxysilane is used as a coupling agent for coupling polyethylene terephthalate; white oil is used as a plasticizer for lubricating related components of polyester film; EPDM rubber is used as a rubber compound; vinyl bisstearamide is used as a lubricant; and carbodiimide is used as a dehydrating agent.

[0044] Specifically, a solvent needs to be added during the preparation of the base film layer; the solvent includes any one of methanol, butanone and cyclohexanone.

[0045] Optionally, the reflective film further includes a UV-resistant coating; the UV-resistant coating is disposed between the adhesive film layer and the base film layer.

[0046] Among them, the UV-resistant coating can be a benzophenone UV absorber and a peroxide.

[0047] Based on the above-mentioned reflective film, an embodiment of the present application further provides a method for preparing the reflective film.

[0048] A method for preparing a reflective film, comprising:

[0049] S10: providing a base film layer; the base film layer comprises a first surface and a second surface opposite to each other;

[0050] S20: forming a reflective microstructure layer on the first surface of the base film layer;

[0051] S30: forming an adhesive film layer on the second surface of the base film layer;

[0052] Among them, the components of the base film layer include polyester film and mica; the mass ratio of the polyester film to the mica is 100:30-100:250; the mass ratio of the polyester film to the base film layer is 10:100-60:100; the mass ratio of the mica to the base film layer is 30:100-70:100.

[0053] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0054] The beneficial effects of the present application will be further illustrated below in combination with embodiments and comparative examples.

[0055] The raw materials used in the embodiments and comparative examples are described below:

[0056] In this embodiment,

[0057] The polyester film is produced by Toray Industries, Inc.; its preparation method is detailed in CN1597312B and CN101090921B;

[0058] The manufacturer of sericite is Anhui Ge Rui New Material Technology Co., Ltd.; its preparation method is detailed in CN115851001A.

[0059] Example 1

[0060] The composition A is prepared by taking polyester film as the matrix and adding sericite; the mass ratio of the polyester film to the sericite is 100:50; the mass ratio of the polyester film to the base film layer is 60:100; and the mass ratio of the sericite to the base film layer is 30:100.

[0061] Example 2

[0062] The composition B is prepared by taking polyester film as the matrix and adding sericite; the mass ratio of the polyester film to the sericite is 100:100; the mass ratio of the polyester film to the base film layer is 45:100; the mass ratio of the sericite to the base film layer is 45:100.

[0063] Example 3

[0064] The composition C is prepared by taking polyester film as the matrix and adding sericite; the mass ratio of the polyester film to the sericite is 100:200; the mass ratio of the polyester film to the base film layer is 30:100; and the mass ratio of the sericite to the base film layer is 60:100.

[0065] Example 4

[0066] The composition D is prepared by taking polyester film as the matrix and adding muscovite; the mass ratio of the polyester film to the muscovite is 100:50; the mass ratio of the polyester film to the base film layer is 60:100; and the mass ratio of the muscovite to the base film layer is 30:100.

[0067] Example 5

[0068] The composition E is prepared by taking polyester film as the matrix and adding muscovite; the mass ratio of the polyester film to the muscovite is 100:100; the mass ratio of the polyester film to the base film layer is 40:100; and the mass ratio of the muscovite to the base film layer is 40:100.

[0069] Example 6

[0070] The composition F is prepared by taking polyester film as the matrix and adding muscovite; the mass ratio of the polyester film to the muscovite is 100:200; the mass ratio of the polyester film to the base film layer is 25:100; and the mass ratio of the muscovite to the base film layer is 50:100.

[0071] Comparative Example 1

[0072] As a blank experiment, the polyester film was directly used for the experiment.

[0073] Comparative Example 2

[0074] As a blank experiment, sericite was directly used for the experiment.

[0075] Comparative Example 3

[0076] As a blank experiment, muscovite was directly used for the experiment.

[0077] The compositions in Examples 1-3, the polyester film in Comparative Example 1, and the sericite in Comparative Example 2 were used as samples to test the changes in reflectivity under different light sources.

[0078] The test method is:

[0079] Reflectivity test under different light sources:

[0080] The test instruments are:

[0081] UV-visible-near infrared spectrometer, model: HITACHI UH4150;

[0082] Specific test steps:

[0083] The light source irradiates the sample, the light interacts with the sample, the detector receives the signal, and the photocurrent is processed to obtain the corresponding value.

[0084] Test results such as Figure 1 As shown in Tables 1, 2, and 3; Figure 1 The horizontal axis represents wavelength (Wavelength), the unit is nm, and the vertical axis represents reflectivity (R), the unit is %; curve 1 represents composition A, curve 2 represents composition B, curve 3 represents composition C, curve 4 represents polyester film, and curve 5 represents sericite.

[0085] Table 1 Reflectivity of samples at wavelengths of 10 to 225 nm

[0086]

[0087] Table 2 Reflectivity of samples at wavelengths of 225 to 300 nm

[0088]

[0089] Table 3 Reflectivity of samples at 300-350nm wavelength

[0090]

[0091] It should be noted that 10 to 350 nm is the ultraviolet region, among which 10 to 200 nm is the far ultraviolet region, and 200 to 350 nm is the near ultraviolet region.

[0092] From the above Tables 1, 2, 3 and Figure 1 The test results show that:

[0093] 1. Based on Figure 1 As shown in Table 1, in the range of (10, 225), the reflectivity of compositions A, B, and C experienced a rising stage and a stable stage. The reflectivity in the rising stage increased from 2.5% to 5%, and the reflectivity in the stable stage was stable at 5%; in the range of (10, 225), the reflectivity of polyester film experienced a rapid rising stage, increasing from 5% to 27%; in the range of (10, 225), the reflectivity of sericite increased slowly and stabilized at about 12%. It can be seen that in the range of the far ultraviolet region and part of the near ultraviolet region, the reflectivity of compositions A, B, and C has always been lower than the reflectivity of polyester film and sericite and stabilized at about 5%, that is, most of the ultraviolet rays are absorbed by compositions A, B, and C, and have a good ultraviolet shielding effect.

[0094] 2. Based on Figure 1As shown in Table 2, in the range of (225, 300), the reflectivity of the compositions A, B, and C is in a stable stage and is stable at 5%; in the range of (225, 300), the reflectivity of the polyester film undergoes a tortuous decline stage, from 27% to 17%; in the range of (225, 300), the reflectivity of the sericite mica undergoes a stable stage and a rapid rise stage, and the reflectivity in the rapid rise stage increases from 11% to 23%. It can be seen that in the near-ultraviolet region, the reflectivity of the compositions A, B, and C is always lower than the reflectivity of the polyester film and sericite mica and is stable at about 5%, that is, most of the ultraviolet rays are absorbed by the compositions A, B, and C, and have a good ultraviolet shielding effect.

[0095] 3. Based on Figure 1 As shown in Table 3, in the range of (300, 350), the reflectivity of compositions A, B, and C is in a stable stage and is stable at 5%; in the range of (300, 350), the reflectivity of polyester film has experienced an upward stage, rising from 17% to 34%; in the range of (300, 350), the reflectivity of sericite has experienced a rapid upward stage, rising from 23% to 57%. It can be seen that in the near-ultraviolet region, the reflectivity of compositions A, B, and C is always lower than that of polyester film and sericite and is stable at about 5%, that is, most of the ultraviolet rays are absorbed by compositions A, B, and C, and have a good ultraviolet shielding effect.

[0096] In summary, the wavelength-reflection curves of the compositions A, B, and C formed by polyester film and sericite at different preferred ratios are similar and overlapped, that is, the compositions at these three ratios have similar excellent effects. Compositions A, B, and C have excellent ultraviolet shielding properties in both the far ultraviolet region and the near ultraviolet region, with a reflectivity that is stably lower than 5% and an absorptivity that is higher than 95%, thereby shielding ultraviolet rays, avoiding the adverse effects of the reflective film being exposed to sunlight for a long time, and increasing the service life of the reflective film.

[0097] The above is a detailed introduction to a reflective film provided by the present application. The principles and implementation methods of the present application are described in detail using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A reflective film, characterized in that: include: An adhesive film layer, a reflective microstructure layer, a base film layer disposed between the adhesive film layer and the reflective microstructure layer, and an ultraviolet-resistant coating disposed between the adhesive film layer and the base film layer; Wherein, any one of methanol, butanone and cyclohexanone is added as a solvent during the preparation of the base film layer; the UV-resistant coating includes a benzophenone UV absorber and a peroxide; The base film layer comprises polyester film and mica, and the mica is sericite mica; The mass ratio of the polyester film to the mica is 100:50 to 100:200; The mass ratio of the polyester film to the base film layer is 10:100 to 60:100; The mass ratio of the mica to the base film layer is 30:100-70:

100.

2. The reflective film according to claim 1, characterized in that: The mass ratio of the polyester film to the mica is 100:

50.

3. The reflective film according to claim 1, characterized in that: The mass ratio of the polyester film to the mica is 100:

100.

4. The reflective film according to claim 1, characterized in that: The mass ratio of the polyester film to the mica is 100:

200.

5. The reflective film according to claim 1, characterized in that: The polyester film comprises polyethylene terephthalate and additives.

6. The reflective film according to claim 5, characterized in that: The additive includes at least one of aminopropyltriethoxysilane, white oil, ethylene propylene diene rubber, vinyl bisstearamide and carbodiimide.

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