An electroluminescent device

Abstract

This application relates to an electroluminescent device, specifically within the technical field of electroluminescence. It comprises a transparent conductive film and a light-emitting portion arranged sequentially. The light-emitting portion includes discontinuously distributed light-emitting areas and filling areas formed by a filler material filling the gaps between the light-emitting areas. The surface free energy of the conductive layer of the transparent conductive film is ≥38 mN / m. The filling areas are EVA resin films with a carboxylic acid group content ≥10 PPM. This application replaces the traditional filler material with an EVA resin film containing carboxylic acid groups. The surface free energy of the transparent conductive film, ≥38 mN / m, improves the adhesion between the transparent conductive film and the filling areas, enabling the electroluminescent device to maintain good adhesion and conductivity even after aging performance testing.

Description

Technical Field

[0001] This application relates to the field of electroluminescence, and more particularly to an electroluminescent device. Background Technology

[0002] Electroluminescence, also known as electroluminescence, is a physical phenomenon in which an electric field is generated by applying a voltage to two electrodes. Electrons excited by the electric field collide with the luminescent center, causing the electrons to transition, change, and recombine between energy levels, resulting in light emission. Electroluminescent glass is a special type of glass that emits light through electroluminescence and is commonly used in automotive glass, exterior curtain walls, interior design, and other applications.

[0003] In existing technologies, the light-emitting structure of electroluminescent devices includes a transparent conductive layer and an electroluminescent part. A light-emitting conductive layer and a non-light-emitting filler layer are added to the electroluminescent part, which allows the electroluminescent device to display specific light-emitting patterns or text. Currently, PVB is often used as the non-light-emitting filler layer. However, PVB generally contains small molecule plasticizers. These plasticizers have low UV blocking rate and poor aging resistance. After aging tests, the filler layer and the light-emitting layer will delaminate. The light-emitting layer will fail more quickly under long-term UV irradiation and moisture, causing it to fail to emit light after being energized, thus failing the aging test of the overall light-emitting device design. Summary of the Invention

[0004] In order to improve the UV aging resistance of electroluminescent devices, this application provides an electroluminescent device.

[0005] The electroluminescent device provided in this application adopts the following technical solution:

[0006] An electroluminescent device includes a transparent conductive film and a light-emitting part arranged sequentially. The light-emitting part includes discontinuously distributed light-emitting areas and filling areas formed by filling material filling the gaps between the light-emitting areas. The surface free energy of the conductive layer of the transparent conductive film is ≥38 mN / m. The filling area is an EVA resin film with a carboxylic acid group content ≥10PPM.

[0007] By adopting the above technical solution, the PVB in the traditional filling area is replaced with an EVA resin film containing carboxylic acid groups. Furthermore, the surface free energy of the conductive layer of the transparent conductive film is ≥38 mN / m. The surface of the conductive layer of the transparent conductive film is preferably N-type semiconductor ITO. The surface of semiconductor ITO is rich in electrons and has Lewis base properties, thus reducing the difference in surface energy between the conductive layer and the filling area. At the same time, the EVA resin film contains carboxylic acid groups, which react with the Lewis base on the ITO surface to form chemical bonds, enhancing the adhesion between the transparent conductive film and the filling area. After subsequent aging tests, the filling area and the transparent conductive film can maintain a good adhesion effect, reducing the occurrence of electroluminescent devices failing to emit light after aging resistance tests.

[0008] Preferably, the EVA resin film comprises an EVA resin matrix with a melt index of 5-30 g / 10 min.

[0009] Preferably, the EVA resin film comprises an EVA resin matrix with a melt index of 10-20 g / 10 min.

[0010] By adopting the above technical solution and limiting the melt index of the EVA resin matrix to 10-20 g / 10 min, a higher performance EVA resin film can be obtained.

[0011] Preferably, the EVA resin film comprises an EVA resin matrix and an organic compound containing carboxylic acid groups, wherein the mass ratio of the organic compound containing carboxylic acid groups to the EVA resin matrix is ​​(0.001-1):100.

[0012] By adopting the above technical solution, controlling the mass ratio between the organic compound containing carboxylic acid groups and the EVA resin matrix within the above range, the overall stability of the electroluminescent device can be improved.

[0013] Preferably, the organic compound containing a carboxylic acid group is a polymer containing a carboxyl group, or an acid anhydride, or a saturated carboxylic acid, or one or more unsaturated carboxylic acids.

[0014] By adopting the above technical solutions, EVA resin film is obtained by copolymerizing a polymer containing carboxyl groups with an EVA resin matrix. Alternatively, an acid anhydride and unsaturated carboxylic acid can be grafted into the EVA resin matrix to obtain an EVA resin film. Or, saturated carboxylic acid can be added by blending to form an EVA resin film with the EVA resin matrix, thereby obtaining a filled area. The filled area can undergo a Schiff base reaction with the ITO of the conductive layer of the transparent conductive film, thereby improving the adhesion stability between the filled area and the transparent conductive film.

[0015] The polymer containing a carboxyl group can be a copolymer of (meth)methacrylate alkyl ester monomer and a polymerizable monomer containing a carboxyl group. The (meth)methacrylate alkyl ester monomer can be one or more of (meth)acrylate n-butyl acrylate, (meth)acrylate 2-butyl acrylate, (meth)acrylate tert-butyl acrylate, (meth)acrylate pentyl acrylate, (meth)acrylate octyl acrylate, (meth)acrylate 2-ethylhexyl acrylate, (meth)acrylate nonyl acrylate, (meth)acrylate decyl acrylate, and (meth)acrylate lauryl acrylate. The polymerizable monomer containing a carboxyl group can be acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, citracic acid, cinnamic acid, succinic acid monohydroxyethyl (meth)acrylate, maleic acid monohydroxyethyl (meth)acrylate, fumaric acid monohydroxyethyl acrylate (meth)acrylate, (meth)acrylate phthalate monohydroxyethyl acrylate, (meth)acrylate 1,2-dicarboxycyclohexane monohydroxyethyl acrylate, (meth)acrylate dimer, and ω-carboxy-polycaprolactone mono(meth)acrylate.

[0016] Acid anhydrides can be acetic anhydride, propionic anhydride, butyric anhydride, benzoic anhydride, maleic anhydride, succinic anhydride, 2-ethylhexanoic anhydride, etc.

[0017] Saturated carboxylic acids can be organic carboxylic acids such as acetic acid;

[0018] Unsaturated carboxylic acids can be one or more of the following: acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, citracic acid, cinnamic acid, monohydroxyethyl (meth)acrylate of succinic acid, monohydroxyethyl (meth)acrylate of maleic acid, monohydroxyethyl (meth)acrylate of fumaric acid, monohydroxyethyl phthalate of (meth)acrylate, 1,2-dicarboxycyclohexane monohydroxyethyl acrylate of (meth)acrylate, (meth)acrylate dimer, and ω-carboxy-polycaprolactone mono(meth)acrylate.

[0019] Preferably, the EVA resin film also includes a UV blocker.

[0020] By adopting the above technical solution, a UV blocker is added to the EVA resin film, which can improve the blocking efficiency of ultraviolet rays and absorb most of the ultraviolet rays in the 190-400nm band. As a result, the blocking rate of ultraviolet rays of the EVA resin film reaches more than 90%, thus giving the EVA resin film the property of resisting ultraviolet rays. After subsequent ultraviolet aging performance tests, there will be no delamination between the EVA resin film and the transparent conductive layer.

[0021] The UV cut-off agent can be one or more of the following UV absorbers: benzophenone-based UV absorbers, salicylates, benzotriazoles, cyanoacrylates, and triazines.

[0022] Preferably, the mass ratio of the EVA resin matrix to the UV cutoff agent is 100:(0.01-0.5).

[0023] By adopting the above technical solution and controlling the mass ratio of EVA resin matrix to UV blocker within the above range, the UV resistance of the filler material can be improved.

[0024] Preferably, the EVA resin film further includes nanofillers.

[0025] By adopting the above technical solution, nanofillers are added to the filling area, making the filling area present different colors, while blocking infrared light.

[0026] Preferably, the light-emitting part includes a conductive layer, a dielectric layer, and an electroluminescent layer arranged in sequence, wherein the electroluminescent layer is bonded to the transparent conductive film.

[0027] By adopting the above technical solution, the conductive layer of the light-emitting part serves as an electrode, thereby enabling the device to emit light.

[0028] Preferably, the light-emitting part further includes an insulating layer located on the side of the conductive layer away from the transparent conductive film.

[0029] By adopting the above technical solution and setting an insulating layer, leakage current during the subsequent use of electroluminescent devices can be reduced, thereby improving the safety performance of electroluminescent devices during use.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. The transparent conductive film has electrons on its surface and has Lewis base properties. The EVA resin film contains carboxylic acid groups. By selecting a transparent conductive film with high surface free energy and an EVA resin film with carboxylic acid groups as the filling area, the EVA resin film reacts with the Lewis base on the surface of the transparent conductive film to form chemical bonds, which improves the adhesion between the transparent conductive film and the filling area. During the subsequent aging process, the adhesion between the filling area and the transparent conductive film is difficult to be destroyed.

[0032] 2. UV blockers are added to the EVA resin film, which can improve the UV resistance of the entire filling area, block UV rays, and thus improve the overall aging resistance of the filling area.

[0033] 3. The addition of nanofillers to the EVA resin film allows the filled areas to display different colors and also blocks infrared light. Detailed Implementation

[0034] This application discloses an electroluminescent device, and the following detailed description is provided in conjunction with the embodiments:

[0035] The filling zone also contains organic peroxide crosslinking agents and silane coupling agents as standard components. The peroxide crosslinking agent can be one or more of the organic peroxides that can initiate crosslinking reactions in polymer materials, such as dialkyl peroxide (ROOR'), diacyl peroxide (RCOOOOCR'), peroxy ester (RCOOOR'), peroxy carbonate (ROCOOOOCOR'), and ketone peroxide [R2C(OOH)2]. Examples include, but are not limited to, dicumyl peroxide, 2-ethylhexyl tert-butylperoxyformate, and 2,5-dimethyl-2,5-di-tert-butylperoxide. Hexane, 1,3-bis-(2-tert-butylperoxyisopropyl)benzene, and (di)benzoyl peroxide; the general formula of silane coupling agents is YSiX3, where Y can be vinyl, epoxy, methacrylate, amino, thiol, etc., and X can be methoxy, ethoxy, chlorine, etc. The silane coupling agent can be one or more of vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, vinyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-mercaptopropyltrimethoxysilane, i.e., silane coupling agents.

[0036] Preparation of the light-emitting region and the transparent conductive film:

[0037] 1. Select PET as the substrate for the transparent conductive film, and sputter ITO onto the surface of PET to obtain the transparent conductive film.

[0038] 2. Printing of luminescent materials: Zinc sulfide is mixed with binder (organic polymer) to form a luminescent paste suitable for screen printing. The luminescent paste is then printed on the surface of a transparent conductive film to obtain an electroluminescent layer.

[0039] 3. Printing of dielectric materials: Barium titanate powder is mixed with binder (organic polymer) to form an insulating paste suitable for screen printing. The insulating paste is then printed on the electroluminescent layer to obtain the dielectric layer.

[0040] 4. Conductive layer printing: Conductive silver paste is printed on the dielectric layer to obtain the conductive layer.

[0041] 5. Printing of colored ink layer and insulating layer: UV-curable ink or thermosetting ink is printed on the conductive layer to obtain the insulating layer.

[0042] The aforementioned printing of luminescent materials, electrolyte materials, conductive layers, colored ink layers, and insulating layers are all existing technologies in this field. The electroluminescent layer, dielectric layer, conductive layer, colored ink printing layer, and insulating layer are arranged on the surface of the transparent conductive film according to the requirements of the luminescent pattern, forming discontinuously distributed luminescent areas.

[0043] Preparation of adhesive film:

[0044] The EVA resin matrix and other additives are mixed, extruded in a molten state, and cooled to form the filler film.

[0045] Combined photos:

[0046] The layers are stacked sequentially from bottom to top in the following order: glass, adhesive film, transparent conductive film with light-emitting area printed on it, filler layer adhesive film, and glass. The layers are then vacuumed in an autoclave and assembled at high temperature.

[0047] Example 1

[0048] Referring to Table 1, take the corresponding materials, mix them all, and extrude them to obtain the filling material. Press all the filling material onto the side of the light-emitting area away from the transparent conductive film, so that a part of the filling material is squeezed into the gap of the entire light-emitting area and adheres to the surface of the transparent conductive film, while the other part of the filling material adheres to the surface of the side of the entire light-emitting area away from the transparent conductive film. After cooling, the electroluminescent device can be obtained.

[0049] Example 2

[0050] Referring to Table 1, take the corresponding materials, stir and mix them all, and then extrude them to obtain the filling material. The content of carboxyl groups in the EVA resin film is 10 PPM. The filling layer is divided into two layers. One layer is hollowed out according to the pattern of the light-emitting area, and the other layer is not hollowed out. The two layers are stacked together and the hollowed-out part is attached to the surface of the transparent conductive film.

[0051] Examples 3-4

[0052] Referring to Table 1, take the corresponding materials, mix them all, and extrude them to obtain the filling material. Press all the filling material onto the side of the light-emitting area away from the transparent conductive film, so that a part of the filling material is squeezed into the gap of the entire light-emitting area and adheres to the surface of the transparent conductive film, while the other part of the filling material adheres to the surface of the side of the entire light-emitting area away from the transparent conductive film. After cooling, the electroluminescent device can be obtained.

[0053]

[0054] Example 5

[0055] Example 5 is based on Example 4. The only difference between Example 5 and Example 4 is that the EVA resin matrix used in Example 5 is from Arkema, France, and the model is 20-20, with a melt index of 20 g / 10 min.

[0056] Example 6

[0057] Example 6 is based on Example 4. The only difference between Example 6 and Example 4 is that in Example 6, acrylic acid is replaced with maleic anhydride, which has an equal carboxyl content after hydrolysis.

[0058] Example 7

[0059] Example 7 is based on Example 4. The only difference between Example 7 and Example 4 is that acrylic acid is replaced with polyacrylic acid (CAS No.: 9003-01-4).

[0060] Example 8

[0061] Example 8 is based on Example 4. The only difference between Example 8 and Example 4 is that acrylic acid is replaced with acetic acid in Example 8.

[0062] Example 9

[0063] Example 9 is based on Example 4. The only difference between Example 9 and Example 4 is that in Example 9, dicumyl peroxide is replaced with tert-butylperoxyformate 2-ethylhexyl ester.

[0064] Example 10

[0065] Example 10 is based on Example 4. The only difference between Example 10 and Example 4 is that vinyltrimethoxysilane is replaced with γ-methacryloxypropyltrimethoxysilane in Example 10.

[0066] Example 11

[0067] Example 11 is based on Example 4. The only difference between Example 11 and Example 4 is that 2-hydroxy-4-methoxybenzophenol is replaced with 2-hydroxy-4-octoxybenzophenone in Example 11.

[0068] Example 12

[0069] Example 12 is based on Example 4. The only difference between Example 12 and Example 4 is that 0.5 parts of nanofiller, which is carbon black, are added to the filler material in Example 12.

[0070] Comparative Example 1

[0071] Comparative Example 1 is based on Example 4. The only difference between Comparative Example 1 and Example 4 is that the amount of organic compound containing carboxylic acid groups added in Comparative Example 1 is 0.0001 parts, and the content of carboxyl groups in the filler material is 1 PPM.

[0072] Comparative Example 2

[0073] Comparative Example 2 is based on Example 4. The only difference between Comparative Example 2 and Example 4 is that 5 parts of the organic compound containing carboxylic acid groups were added in Comparative Example 2, and the content of carboxyl groups in the filler material was 50,000 PPM.

[0074] Comparative Example 3

[0075] Comparative Example 3 is based on Example 4. The only difference between Comparative Example 3 and Example 4 is that the UV cutoff agent added in Comparative Example 3 is 0.1 parts.

[0076] Comparative Example 4

[0077] Comparative Example 4 is based on Example 4. The only difference between Comparative Example 4 and Example 4 is that no UV stopper was added in Comparative Example 4.

[0078] Comparative Example 5

[0079] Comparative Example 5 is based on Example 3. The only difference between Comparative Example 5 and Example 3 is that the ITO used in the transparent conductive film of Comparative Example 5 is SMH-19H-10, and its surface free energy is 36 mN / m.

[0080] Comparative Examples 6-7

[0081] Comparative Examples 6-7 are based on Example 4, and the EVA resin matrix is ​​selected from the corresponding models in Table 2.

[0082]

[0083] Samples of the light-emitting device specimens from Examples 1-12 and Comparative Examples 1-7 were taken, and the initial adhesion strength of the specimens was tested. The results were recorded in Table 3, followed by aging resistance tests.

[0084] (1) High-temperature aging performance test

[0085] The specimens were aged at 110℃ for 1000 hours. Each specimen was sampled and tested three times, and the average value was taken. The results were recorded in Table 4.

[0086] (2) Damp heat aging performance test

[0087] Under high temperature and humidity conditions of 60℃ and 95%RH, the samples were tested for 336 hours. Each sample was tested 3 times and the average value was taken. The results were recorded in Table 5.

[0088] (3) Water boiling aging performance test

[0089] Take three samples from each specimen and boil them in water at 100°C for 4 hours under standard atmospheric pressure to test their resistance to damp heat aging. Take the average value of the test results and fill them in Table 6.

[0090] (4) High-temperature alternating impact aging performance test

[0091] Three samples were taken from each specimen and subjected to impact at high and low temperatures of -40℃ to 80℃. The high and low temperatures were cycled once every 12 hours for 100 cycles. The adhesive strength performance was tested, and the average value was recorded in Table 7.

[0092] (5) Ultraviolet lamp aging performance test

[0093] The test standard was selected as "GB / T5137.3 Test Methods for Automotive Safety Glass Part 3: Resistance to Radiation, High Temperature, Humidity, Combustion and Simulated Climate". The aging performance was tested under ultraviolet light, and the average value of the test results was taken. The test results were filled in Table 8.

[0094] (6) Luminescence rate test

[0095] 100 samples of 10cm×10cm were prepared for each sample. Luminescence tests were conducted before and after aging. The luminescence test conditions were: AC110V power supply for 10s, 100 cycles. The average value of the test results was recorded in Table 4-8.

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103] Performance data analysis

[0104] The adhesion strength of Examples 1-12 after aging was above 30.00 N / cm, indicating that the electroluminescent devices prepared in this application have good aging resistance. The haze of Examples 1-12 after various aging tests was below 5, indicating that the electroluminescent devices prepared in this application have good light transmittance. After various aging tests, Examples 1-12 showed no bubbles on the surface and no delamination, and the luminescence rate after aging was 95% or higher, indicating that the electroluminescent devices prepared in this application have good aging resistance. After UV lamp aging, the UV blocking rate of Examples 1-12 in the 190-400 nm range was above 95%, indicating that the electroluminescent devices prepared in this application have good UV resistance.

[0105] The only difference between Examples 6-8 and Example 4 is that different organic compounds containing carboxylic acid groups were selected in Examples 6-8. The adhesion strength of Examples 6-8 fluctuated slightly after different aging performance tests, but the adhesion strength was all above 30.00 N / cm. This indicates that the carboxyl groups of different organic compounds containing carboxylic acid groups can react with the Lewis base on the ITO surface, so that the filler material and the transparent conductive layer can maintain good adhesion performance after various aging tests.

[0106] In Examples 9-11, different substitutions were made for the organic peroxide crosslinking agent, silane coupling agent, and UV stopper. The adhesive strength of Examples 9-11 fluctuated slightly after different aging performance tests, but the adhesive strength after aging was all above 30.00 N / cm. This shows that in this application, by selecting different peroxide crosslinking agents, different silane coupling agents, or different types of UV stoppers, good adhesive performance can be obtained after various aging resistance tests.

[0107] In Example 12, carbon black nanofiller was added to the filler. The adhesion strength fluctuated slightly after different aging performance tests, but the adhesion strength after aging was above 30.00 N / cm, indicating that the addition of carbon black nanofiller had little effect on the adhesion strength.

[0108] The carboxyl content in the filler material of Comparative Example 1 was 1 ppm. After different aging performance tests, the adhesion of Comparative Example 1 was less than 30.00 N / cm. This may be because the carboxyl content in the filler material is too low, making it difficult to have good bonding performance with the Lewis base on the ITO surface. As a result, the adhesion strength between the filler material and the transparent conductive layer decreases. After various aging tests, delamination occurs between the filler material and the transparent conductive layer. Furthermore, the luminous efficiency of the electroluminescent device decreases after energization, and bubbles and haze appear on the surface.

[0109] The carboxyl content in the filler material of Comparative Example 2 is above 10000 PPM. After different aging performance tests, the adhesion of Comparative Example 2 decreased and was less than 30.00 N / cm. This may be because the high carboxyl content in the filler material will affect the stability of the filler material and lead to a decrease in the adhesion between it and the transparent conductive layer, thus resulting in a decrease in performance after aging.

[0110] In Comparative Example 3, the amount of UV cutoff agent added was 0.1 parts. After various aging performance tests, the adhesion ratio of Comparative Example 3 decreased significantly. This may be because excessive UV cutoff agent will affect the stability of the filler material, thereby reducing the adhesion performance of the filler material.

[0111] No UV blocker was added in Comparative Example 4. After UV aging performance test, the adhesion of Comparative Example 3 decreased significantly. This may be because the UV blocking rate between 190-400nm in Comparative Example 4 decreased. Therefore, after UV aging, bubbles were generated on the surface and severe delamination occurred.

[0112] The surface free energy of ITO in Comparative Example 5 is 36 mN / m. After different aging performance tests, the adhesion of Comparative Example 5 decreased. This may be because the surface energy of ITO is too small, which makes the surface tension difference between the transparent conductive layer and the filler material too large, which weakens the Lewis base reaction between the filler material and the transparent conductive layer. Therefore, the adhesion between the transparent conductive layer and the filler material decreases significantly.

[0113] The melt index of the EVA resin film in Comparative Example 6 was 2 g / 10 min. After different aging performance tests, the adhesion of Comparative Example 6 decreased. This may be because the melt index of the EVA resin matrix was too low, which reduced the fluidity of the EVA resin film and reduced the stability of the entire system. Therefore, the luminescence of Comparative Example 6 decreased and delamination occurred, and the light transmittance also decreased.

[0114] The melt index of the EVA resin film in Comparative Example 7 was 65 g / 10min. After different aging performance tests, the adhesion of Comparative Example 7 decreased. This may be because when the melt index of the EVA resin matrix is ​​too high, the content of low molecular weight components in the whole system increases, the stability of the whole system decreases, so the adhesion of Comparative Example 7 decreases, and the luminescence rate also decreases after aging. Bubbles appear on the surface and delamination occurs.

[0115] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. An electroluminescent device comprising a transparent conductive film and a light emitting portion arranged in this order, the light emitting portion comprising discontinuously distributed light emitting regions and filling regions formed of a filling material which fill gaps between the light emitting regions, characterized in that: The surface free energy of the conductive layer of the transparent conductive film is ≥38 mN / m; the filling region is an EVA resin film with a carboxylic acid group content ≥10PPM. The EVA resin film comprises an EVA resin matrix and an organic compound containing carboxylic acid groups, wherein the mass ratio of the organic compound containing carboxylic acid groups to the EVA resin matrix is ​​(0.001-1):

100. The organic compound containing a carboxylic acid group is a polymer containing a carboxyl group, or an acid anhydride, or a saturated carboxylic acid, or one or more unsaturated carboxylic acids. The EVA resin film contains carboxylic acid groups, and the EVA resin film forms chemical bonds after reacting with the Lewis base on the surface of the transparent conductive film. The EVA resin film comprises an EVA resin matrix with a melt index of 5-30 g / 10 min.

2. The electroluminescent device according to claim 1, characterized in that: The EVA resin film comprises an EVA resin matrix with a melt index of 10-20 g / 10 min.

3. The electroluminescent device according to claim 1, characterized in that: The EVA resin film also includes a UV blocking agent.

4. The electroluminescent device according to claim 3, characterized in that: The mass ratio of the EVA resin matrix to the UV cutoff agent is 100:(0.01-0.5).

5. An electroluminescent device according to claim 1, characterized in that: The EVA resin film also includes nanofillers.

6. The electroluminescent device according to claim 1, characterized in that: The light-emitting part includes a conductive layer, a dielectric layer, and an electroluminescent layer arranged in sequence, and the electroluminescent layer is bonded to a transparent conductive film.

7. An electroluminescent device according to claim 6, characterized in that: The light-emitting part also includes an insulating layer, which is located on the side of the conductive layer away from the transparent conductive film.