Multilayer co-extruded composite light diffusion panel

Abstract

The utility model discloses a kind of multi-layer co-extrusion composite light diffusion plate, it is related to optical plate technical field.The utility model includes plate body, it includes flame-retardant support layer, diffusion layer, optical layer and wear-resistant UV resistance layer by inside to outside sequentially arranged by multi-layer co-extrusion process, wear-resistant UV resistance layer outside is coated with AR coating, frame, it is set with half surrounding around plate body.The utility model makes each layer between tightly combined by multi-layer co-extrusion process, integrity is strong, flame-retardant support layer guarantees the fire safety of plate in use;Diffusion layer and optical layer work cooperatively, optimize light diffusion effect, improve the uniformity and comfort of illumination;Wear-resistant UV resistance layer prolongs the service life of plate, so that it can adapt to outdoor and other harsh environment;AR coating improves the transmittance of light, reduces light loss, improves the efficiency of illumination or display;Frame then enhances the mechanical strength of plate, prevents edge knock damage, facilitates installation and fixed.

Description

Technical Field

[0001] This utility model belongs to the field of optical sheet materials, specifically, it relates to a multilayer co-extruded composite light diffusion sheet material. Background Technology

[0002] Light diffusers utilize the physical phenomena of refraction, reflection, and scattering that occur when light encounters two media with different refractive indices during its journey, through chemical or physical means. Traditional processing methods typically involve first mixing the raw materials for each layer evenly, then heating them to a molten state using a screw extruder, extruding the corresponding structural layers, and then conveying them to a bonding station for alignment and bonding. Finally, they are pressed together using a multi-layer co-extrusion machine. Another method involves directly extruding a multi-layer composite structure using a combination of multi-layer co-extrusion dies in a screw extruder. However, existing light diffusers have flat light-incident and light-exit surfaces. After the LED light source is refracted and diffused by the milky white diffusing agent, it is easily refracted out of the flat diffuser, resulting in uneven light distribution and severe light loss.

[0003] Chinese patent CN214795270U discloses a multilayer co-extruded composite light diffusion plate. This device selectively reflects the light of the backlight system through a DBEF optical sheet, preventing it from being absorbed by the lower polarizer of the LCD. This allows some of the light from the LCD to be reused across the entire viewing angle. When used in combination with a BEF optical sheet, it can further increase brightness. At the same time, the surface structure of the micro-prism plate changes the beam angle, suppresses the luminance of the lamp in non-illuminated areas, suppresses high-angle light, controls glare, improves lighting comfort, and enhances lighting efficiency. However, during use, the design of each structure results in insufficient overall durability and poor environmental adaptability, thus affecting the lifespan of the device.

[0004] In view of this, this utility model is hereby proposed. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a multilayer co-extruded composite light diffusion plate, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by this utility model is as follows: A multi-layer co-extruded composite light diffusion board includes: a board body, which includes a flame-retardant support layer, a diffusion layer, an optical layer and a wear-resistant and UV-resistant layer arranged sequentially from the inside to the outside by a multi-layer co-extrusion process, wherein the wear-resistant and UV-resistant layer is coated with an AR coating on its outer side. The frame is set in a semi-enclosed shape around the body of the plate.

[0007] Optionally, the wear-resistant and UV-resistant layer is formed by co-extrusion of a thermoplastic resin-based material, a UV-resistant agent, and nano-alumina particles.

[0008] Optionally, the diffusion layer contains multiple groups of SiO2 particles distributed in a gradient, with the concentration of the multiple groups of SiO2 particles gradually increasing from the light-incident side to the light-exit side of the diffusion layer.

[0009] Optionally, the solubility of SiO2 particles on the light-incident side of the diffusion layer ranges from 2.5% to 3.5%, and the solubility of SiO2 particles on the light-exit side of the diffusion layer ranges from 7.5% to 8.5%.

[0010] Optionally, the optical layer is made of PMMA.

[0011] Optionally, the surface of the optical layer is co-extruded with micron-sized prismatic protrusions.

[0012] Optionally, the flame-retardant support layer is formed by co-extrusion of a base resin with a halogen-free phosphorus flame retardant.

[0013] Optionally, a conductive antistatic layer is co-extruded between the flame-retardant support layer and the diffusion layer.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the following advantages at the same time: 1. By incorporating a flame-retardant support layer, a wear-resistant and UV-resistant layer, and an AR coating, and employing a multi-layer co-extrusion process to ensure a tight bond between the layers, the material exhibits strong overall integrity. The flame-retardant support layer guarantees the fire safety of the board during use; the diffusion layer and optical layer work together to optimize light diffusion, improving the uniformity and comfort of illumination; the wear-resistant and UV-resistant layer extends the service life of the board, enabling it to withstand harsh outdoor environments; the AR coating increases light transmittance, reduces light loss, and improves the efficiency of lighting or displays; and the frame enhances the mechanical strength of the board, preventing edge damage and facilitating installation and fixation. 2. By setting a conductive antistatic layer, the static electricity problem of the board during use is effectively solved, preventing static electricity from attracting dust and impurities, keeping the board surface clean, and thus maintaining good optical performance.

[0015] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0016] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a structural schematic diagram from another perspective of the present invention; Figure 3 This is a schematic diagram of the internal structure of the present invention after it has been cut open; Figure 4 This is a top view of the present invention; Figure 5 This utility model Figure 4 Sectional view at point AA; Figure 6 This utility model Figure 5 A magnified structural diagram at point B in the middle.

[0017] The attached diagram lists the components represented by each number as follows: 1. Flame-retardant support layer; 2. Conductive and antistatic layer; 3. Diffusion layer; 4. Optical layer; 5. Wear-resistant and UV-resistant layer; 6. AR coating; 7. Frame.

[0018] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings.

[0020] Example 1 Please see Figure 1-6 As shown, this embodiment provides a multi-layer co-extruded composite light diffusion board, including a board body, which includes a flame-retardant support layer 1, a diffusion layer 3, an optical layer 4 and a wear-resistant and UV-resistant layer 5 arranged sequentially from the inside to the outside through a multi-layer co-extrusion process. The wear-resistant and UV-resistant layer 5 is coated with an AR coating 6 on its outer side and a frame 7, which is arranged in a semi-enclosed shape around the board body.

[0021] Specifically, light enters from one side of the board and first passes through the flame-retardant support layer 1. This layer mainly serves a supporting and flame-retardant function and does not directly participate in the adjustment of optical performance. Next, it enters the diffusion layer 3, where the light-diffusing medium scatters the light, evenly dispersing the concentrated light. The light then reaches the optical layer 4, which further adjusts and optimizes the direction of the light, improving its distribution. The wear-resistant and UV-resistant layer 5 protects the internal structure of the board while resisting ultraviolet radiation and preventing aging. The outermost AR coating 6 reduces light reflection from the board surface and increases light transmittance. The frame 7 is used for fixing and protecting the board. The protective layer prevents damage to the board body from collisions during handling, installation, and use. A multi-layer co-extrusion process ensures a tight bond between layers, resulting in strong overall integrity. The flame-retardant support layer 1 guarantees the fire safety of the board during use. The diffusion layer 3 and optical layer 4 work together to optimize light diffusion, improving the uniformity and comfort of illumination. The wear-resistant and UV-resistant layer 5 extends the board's lifespan, enabling it to withstand harsh outdoor environments. The AR coating 6 increases light transmittance, reduces light loss, and improves the efficiency of lighting or displays. The frame 7 enhances the board's mechanical strength, prevents edge damage from impacts, and facilitates installation and fixation.

[0022] It should be noted that the flame-retardant support layer 1, diffusion layer 3, optical layer 4, and wear-resistant UV-resistant layer 5 are fused together under high temperature and pressure through a multi-layer co-extrusion process. The molecules between each layer diffuse and permeate each other, forming a strong bond. The AR coating 6 is tightly attached to the wear-resistant UV-resistant layer 5 through vacuum coating or other processes. The frame 7 is usually mechanically connected to the board body, such as by slots or screws, to ensure a tight fit without affecting the optical performance of the board. Furthermore, the multi-layer co-extrusion process requires precise control of parameters such as temperature, flow rate, and pressure of each layer to ensure uniform thickness and good bonding of each layer. The semi-enclosed design of the frame 7 can effectively protect the board without excessively blocking light. Its specific shape and size can be customized according to the actual application scenario and installation requirements.

[0023] In this embodiment, as Figures 4 to 6As shown, the wear-resistant and UV-resistant layer 5 is co-extruded from thermoplastic resin-based material, UV-resistant agent, and nano-alumina particles. Specifically, the thermoplastic resin-based material serves as the main body, providing structural support and basic physical properties. The UV-resistant agent absorbs or reflects ultraviolet rays, converting the energy of ultraviolet rays into heat energy or other harmless forms, thereby reducing the damage of ultraviolet rays to the internal structure of the board. The nano-alumina particles are uniformly dispersed in the resin, which on the one hand enhances the hardness and wear resistance of the wear-resistant and UV-resistant layer 5, and on the other hand, the presence of nanoparticles has a certain scattering effect on light, assisting the light diffusion effect to a certain extent. This layer structure design significantly improves the weather resistance and wear resistance of the board. The addition of the UV-resistant agent effectively prevents the board from yellowing, becoming brittle, and aging due to long-term ultraviolet radiation, extending the service life of the board and making it suitable for long-term outdoor use. The nano-alumina particles enhance the surface hardness, reduce scratch damage during daily use, maintain the integrity of the board surface, and thus maintain good optical performance.

[0024] It should be noted that thermoplastic resin-based materials such as PC, PMMA, and PS (polystyrene) can be selected. These materials have good processing and optical properties. UV absorbers can be benzotriazoles, benzophenones, hindered amines, or other UV absorbers or light stabilizers. The particle size of nano-alumina is generally between tens and hundreds of nanometers, and it has the characteristics of high hardness and high chemical stability. Secondly, through a multi-layer co-extrusion process, the thermoplastic resin-based material, UV absorber, and nano-alumina particles are fully mixed in the molten state and tightly fused with the optical layer 4. During the co-extrusion process, the UV absorber and nano-alumina particles are uniformly dispersed in the resin melt, and they achieve molecular-level bonding with the optical layer 4 as the melt flows. Furthermore, the amount of nano-alumina particles added needs to be strictly controlled. Too much may affect the resin's flowability and optical properties, while too little will not be able to fully exert its role in enhancing wear resistance. The type and amount of UV absorber also need to be optimized according to the UV intensity of the actual use environment to achieve the best anti-aging effect.

[0025] Example 2 In this embodiment, as Figures 4 to 6As shown, the diffusion layer 3 contains multiple groups of SiO2 particles arranged in a gradient. The concentration of these SiO2 particles gradually increases from the light-incident side to the light-exit side of the diffusion layer 3. The concentration of SiO2 particles on the light-incident side of the diffusion layer 3 ranges from 2.5% to 3.5%, while the concentration on the light-exit side ranges from 7.5% to 8.5%. Specifically, when light enters the diffusion layer 3 from the light-incident side, the lower concentration of SiO2 particles on the light-incident side initially scatters the light, reducing initial light loss and ensuring a certain level of light transmittance. As the light propagates towards the light-exit side, the concentration of SiO2 particles gradually increases, enhancing the scattering effect and further homogenizing the light diffusion. Ultimately, this achieves a balance between high light transmittance and high haze. This gradient distribution design overcomes the problem of difficulty in simultaneously achieving high transmittance and haze caused by the uniform particle distribution in traditional diffusion layers 3. While ensuring sufficient light diffusion, it minimizes light loss during the diffusion process, improving light utilization efficiency and enabling the board to provide a uniform, soft, and bright light effect under different lighting conditions.

[0026] It should be noted that the matrix material of the diffusion layer 3 is generally a thermoplastic resin, such as PC, PMMA, PS, etc.; the SiO2 particles are nano-sized silica with a particle size usually between 10-100nm, which has good light scattering properties and chemical stability. Its dispersion in the resin requires the help of dispersants and other additives to ensure that the particles are evenly distributed and form a gradient concentration. Secondly, through a multi-layer co-extrusion process, resin melts containing different concentrations of SiO2 particles are co-extruded together in a preset gradient distribution order. During the co-extrusion process, the flow rate and ratio of each layer of melt are precisely controlled by using a specially designed co-extrusion die and feeding system, thereby realizing a gradient change in the concentration of SiO2 particles and tightly connecting them with the flame-retardant support layer 1 and the optical layer 4.

[0027] In this embodiment, as Figures 1 to 6As shown, the optical layer 4 is made of PMMA. Micron-sized prismatic protrusions are co-extruded onto the surface of optical layer 4. Specifically, PMMA has excellent optical transparency and a moderate refractive index, resulting in good light transmission and refraction. When light enters optical layer 4 from diffusion layer 3, the PMMA material can effectively guide and adjust the light, changing its propagation direction and making the light distribution more uniform, thus improving the quality of lighting or display. Through a multi-layer co-extrusion process, under high temperature and pressure, the PMMA melt is tightly fused with the melt of diffusion layer 3 and the wear-resistant and UV-resistant layer 5. Furthermore, the micron-sized prismatic protrusions alter the microstructure of the surface of optical layer 4. When light shines on these protrusions, refraction and reflection occur. The shape and arrangement of the prismatic protrusions cause the light to refract in a specific direction, further guiding the diffused light and making it more concentrated to shine outwards, reducing light loss on the sides and improving the light intensity and uniformity on the front. These prismatic protrusions significantly improve the optical layer 4's ability to control light. By optimizing parameters such as the size, shape, and density of the protrusions, precise control of light distribution can be achieved (this is existing technology). In lighting applications, this can improve lighting efficiency and reduce energy waste. In display applications, it can enhance the contrast and clarity of the image and improve the visual effect.

[0028] It should be noted that during the multi-layer co-extrusion process, when the PMMA melt flows through the mold with the prismatic protrusion structure, the melt fills the mold cavity under pressure, forming prismatic protrusions, which are tightly connected to the optical layer 4 body. This connection method is based on the fluidity of the PMMA melt at high temperature and its adhesion after curing. It works in conjunction with the connection method of the diffusion layer 3 and the wear-resistant and UV-resistant layer 5 to ensure the integrity of the entire sheet structure.

[0029] In this embodiment, as Figures 1 to 6As shown, the flame-retardant support layer 1 is formed by co-extrusion of a halogen-free phosphorus-based flame retardant into the base resin. Specifically, the halogen-free phosphorus-based flame retardant undergoes chemical reactions such as decomposition at high temperatures, forming substances with flame-retardant properties. When exposed to an ignition source, these decomposition products can capture free radicals generated during combustion, interrupting the combustion reaction chain and thus preventing the spread of flames. Simultaneously, the presence of the flame retardant can also reduce the thermal decomposition rate of the base resin to a certain extent, reducing the generation of combustible gases and achieving flame retardant and smoke-suppressing effects. The halogen-free phosphorus-based flame retardant has good environmental performance, avoiding the problem of toxic and harmful gases produced during combustion by traditional halogenated flame retardants. It should be noted that the base resin can be thermoplastic resins such as PC and PP, which have good mechanical and processing properties. There are many types of halogen-free phosphorus flame retardants, the most common of which are phosphate esters. The amount added is generally adjusted according to the type of resin and the required flame retardant level, usually between 5% and 30%. Before multi-layer co-extrusion, the halogen-free phosphorus flame retardant and the base resin are thoroughly mixed evenly in equipment such as a high-speed mixer. Then, the mixed material is melt-extruded through an extruder and melt-bonded with other layers such as diffusion layer 3 in the co-extrusion die. During the co-extrusion process, the layers form a strong connection through molecular diffusion and physical entanglement.

[0030] Example 3 In this embodiment, as Figures 1 to 6 As shown, a conductive antistatic layer 2 is co-extruded between the flame-retardant support layer 1 and the diffusion layer 3. Specifically, the conductive materials (such as carbon nanotubes, metal fibers, etc.) in the conductive antistatic layer 2 can form a conductive path. In practical applications, when static electricity is generated on the surface of the board, the static charge can be quickly conducted and dissipated through the conductive antistatic layer 2, avoiding static accumulation. At the same time, in some electromagnetic environments, the conductive antistatic layer 2 can also provide a certain shielding effect on electromagnetic waves, reducing the impact of external electromagnetic interference on the internal optical performance of the board and other electronic devices. The setting of the conductive antistatic layer 2 effectively solves the static electricity problem of the board during use, prevents static electricity from attracting dust, impurities, etc., keeps the board surface clean, and thus maintains good optical performance. In application scenarios such as electronic devices that are sensitive to electromagnetic environments, the electromagnetic shielding function of the conductive antistatic layer 2 can improve the stability and reliability of the equipment and prevent the optical performance from being affected by electromagnetic interference.

[0031] It should be noted that the matrix material of the conductive antistatic layer 2 is generally a thermoplastic resin with good compatibility with the flame-retardant support layer 1 and the diffusion layer 3, such as PC or PS. The conductive material can be carbon nanotubes, graphene, metal fibers (such as copper fibers or silver fibers), etc. The amount added is adjusted according to the required conductivity and electromagnetic shielding effect, generally between 1% and 10%. Secondly, through a multi-layer co-extrusion process, the resin melt containing the conductive material is co-extruded between the flame-retardant support layer 1 and the diffusion layer 3. During the co-extrusion process, the conductive antistatic layer 2 and the two adjacent layers achieve molecular-level fusion under high temperature and high pressure, forming a tight connection to ensure the stability of conductivity and the overall structural strength.

[0032] Working principle: Light enters from one side of the board and first passes through the flame-retardant support layer 1. This layer mainly serves a supporting and flame-retardant function and does not directly participate in the adjustment of optical performance. Next, it enters the diffusion layer 3, where the light-diffusing medium scatters the light, evenly dispersing the concentrated light. The light then reaches the optical layer 4, which further adjusts and optimizes the direction of the light, improving its distribution. The wear-resistant and UV-resistant layer 5 protects the internal structure of the board while resisting ultraviolet radiation and preventing aging. The outermost AR coating 6 reduces light reflection from the board surface and increases light transmittance. The frame 7 is used to fix and protect the board. The material body is designed to prevent damage from impacts during handling, installation, and use. A multi-layer co-extrusion process ensures a tight bond between layers, resulting in strong overall integrity. The flame-retardant support layer 1 guarantees the fire safety of the board during use. The diffusion layer 3 and optical layer 4 work together to optimize light diffusion, improving the uniformity and comfort of illumination. The wear-resistant and UV-resistant layer 5 extends the board's lifespan, enabling it to withstand harsh outdoor environments. The AR coating 6 increases light transmittance, reduces light loss, and improves the efficiency of lighting or displays. The frame 7 enhances the mechanical strength of the board, prevents edge damage from impacts, and facilitates installation and fixation.

[0033] This utility model is not limited to the above-described embodiments. Anyone should know that structural changes made under the guidance of this utility model, and any technical solutions that are the same as or similar to this utility model, fall within the protection scope of this utility model. Technical aspects, shapes, and structures not described in detail in this utility model are all publicly known technologies.

Claims

1. A multilayer co-extruded composite light diffusion sheet, characterized in that, include: The sheet body includes a flame-retardant support layer (1), a diffusion layer (3), an optical layer (4) and a wear-resistant and UV-resistant layer (5) arranged sequentially from the inside to the outside through a multi-layer co-extrusion process. The wear-resistant and UV-resistant layer (5) is coated with an AR coating (6) on its outer side. The frame (7) is set in a semi-enclosed shape around the body of the plate.

2. The multilayer co-extruded composite light diffusion sheet according to claim 1, characterized in that, The optical layer (4) is made of PMMA.

3. The multilayer co-extruded composite light diffusion sheet according to claim 2, characterized in that, The optical layer (4) has micron-sized prismatic protrusions co-extruded on its surface.

4. The multilayer co-extruded composite light diffusion sheet according to claim 3, characterized in that, A conductive antistatic layer (2) is co-extruded between the flame-retardant support layer (1) and the diffusion layer (3).

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