Optical functional plate and preparation method thereof

Abstract

The present invention provides an optical functional plate and a preparation method thereof, wherein the optical functional plate comprises a light emitting layer, a main body layer and a light incident layer connected in sequence, wherein the main body layer comprises a substrate and a plurality of microporous structures located in the substrate, and the distribution density of the microporous structures gradually decreases along the center to the outer edge of the substrate. The present invention adopts expandable polystyrene as the substrate of the main body layer, so that the prepared optical functional plate has a foamed microporous structure, and at the same time, during the plate processing, the particle size of the pores in the foamed substrate layer, the thickness of the substrate layer and the processing uniformity are controlled by controlling the processing temperature, extrusion amount, extrusion line speed and other parameters of the main body layer extruder and adjusting the content of expandable polystyrene particles; the process is simple, less materials are used, and raw material consumption and production costs can be reduced, providing a new idea for the lightweighting of optical functional plates.

Description

Technical Field

[0001] The present invention relates to the technical field of backlight and lighting, and in particular to an optical functional plate and a preparation method thereof. Background Art

[0002] Optical plates are widely used in liquid crystal displays, LED lighting and imaging display systems. Through chemical or physical means, they utilize the physical phenomena of refraction, reflection and scattering that occur when light encounters two media with different refractive indices (densities) on the way. The light coupled into the plate is reflected and refracted, and the line light source or point light source is converted into a surface light source, thereby achieving the effect of homogenizing the light source.

[0003] At present, the base materials of optical plates are usually plastics such as PMMA / PC / PE / PS. However, due to the single material, these plates have the disadvantages of insufficient diffusion, poor light uniformity and heavy weight. Summary of the invention

[0004] The present invention aims to solve the problem to a certain extent: how to provide an optical functional plate with higher uniformity and brightness, lower power consumption and lighter weight.

[0005] To solve the above problems, the present invention provides an optical functional plate, which is made by co-extrusion in an extruder mold, and includes a light-emitting layer, a main layer and a light-incoming layer connected in sequence, the main layer includes a substrate and a plurality of microporous structures located in the substrate, and the distribution density of the microporous structure gradually decreases from the center to the outer edge of the substrate.

[0006] Optionally, the pore size of the microporous structure is 5-100 μm.

[0007] Optionally, the thickness of the light emitting layer and the light incident layer each accounts for 9%-11% of the total thickness of the optical functional plate.

[0008] Optionally, the total thickness of the optical functional plate is 0.8-3.0 mm.

[0009] Optionally, a surface of the light emitting layer facing away from the main layer and / or a surface of the light incident layer facing away from the main layer are both provided with a plurality of microstructures of preset shapes.

[0010] Optionally, the preset shape includes at least one of a prism, a quadrangular pyramid, a hemisphere, a triangular prism, a triangular pyramid, a cone, a truncated cone and a frosted shape.

[0011] Another object of the present invention is to provide a method for preparing an optical functional plate, so as to provide an optical functional plate with higher uniformity and brightness, lower power consumption and lighter weight.

[0012] To achieve the above object, the technical solution of the present invention is implemented as follows:

[0013] A method for preparing an optical functional plate, for preparing the optical functional plate as described above, comprises the following steps:

[0014] Feeding the light-emitting layer mixture, the main layer mixture and the light-incoming layer mixture into three extruders respectively, wherein the main layer mixture includes expandable polystyrene or a mixture of expandable polystyrene and polystyrene;

[0015] After the mixed materials in the three extruders are melted respectively, a composite sheet is formed by in-mold co-extrusion, wherein the melting temperature of the mixed materials in the light-emitting layer and the melting temperature of the mixed materials in the light-incoming layer are both 5-15° C. higher than the melting temperature of the mixed materials in the main body layer;

[0016] The composite board is trimmed according to a preset size, and then dusted, cooled and shaped to obtain the optical functional board.

[0017] Optionally, after the preset mixed materials in the three extruders are melted respectively and the composite sheet is formed by in-mold co-extrusion, the following steps are further included:

[0018] The upper surface and / or lower surface of the composite board is hot-pressed to form a corresponding microstructure through a roller with a microstructure of a preset shape engraved on the surface.

[0019] Optionally, by weight,

[0020] The components of the light-emitting layer mixture include: 72-95% polystyrene, 4-10% silicone light diffuser, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, and 0.5-10% toughening agent;

[0021] The components of the main layer mixture include: 48-99% expandable polystyrene, 0-39.0% polystyrene, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, 0.5-5% toughening agent;

[0022] The components of the light incident layer mixture include: 57-90% polystyrene, 9-30% silicone light diffuser, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, and 0.5-5% toughening agent.

[0023] Optionally, the extruders corresponding to the light-emitting layer mixture and the light-incoming layer mixture both include a vacuum exhaust device, and the vacuum degree of the vacuum exhaust device is -0.08 to 0.1 Mpa.

[0024] Compared with the prior art, the optical functional plate and the preparation method thereof provided by the present invention have the following advantages:

[0025] (1) The present invention arranges a plurality of microporous structures in the main layer and limits the position distribution of the microporous structures, so that the closer the position on the substrate is to the light emitting layer or the light incident layer, the fewer the microporous structures are. This not only ensures that the microporous structures can be beneficial to the diffusion of the light spot, thereby enhancing the light guiding property of the optical functional plate; it also avoids the problem of poor bonding between the main layer and the light emitting layer or the light incident layer, and easy falling off, caused by too many microporous structures in contact with the light incident layer or the light emitting layer, thereby improving the overall structural stability of the optical functional plate.

[0026] (2) The present invention adopts expandable polystyrene as the substrate of the main layer, so that the prepared optical functional plate has a foamed microporous structure. At the same time, during the plate processing process, the particle size of the pores in the foamed substrate layer, the thickness of the substrate layer and the processing uniformity are controlled by controlling the processing temperature, extrusion volume, extrusion line speed and other parameters of the main layer extruder and adjusting the content of expandable polystyrene particles. The process is simple and requires less materials, which can reduce raw material consumption and production costs, and provides a new idea for lightweight optical functional plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a process for preparing an optical functional plate according to an embodiment of the present invention;

[0028] Figure 2 This is one of the structural schematic diagrams of the optical functional plate according to an embodiment of the present invention;

[0029] Figure 3 This is the second structural schematic diagram of the optical functional plate according to the embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 1-light emitting layer, 2-main layer, 21-matrix, 22-microporous structure, 3-light incident layer, 4-microstructure. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0033] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back ...) are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture. If the specific posture changes, the directional indication will also change accordingly, and the connection can be a direct connection or an indirect connection. In addition, the meaning of the terms "comprise", "include", "contain", and "have" is non-restrictive, and other steps and other ingredients that do not affect the results can be added. If not otherwise specified, materials, equipment, and reagents are all commercially available.

[0034] In addition, although the present invention describes the steps in the preparation in the form of S1, S2, S3, etc., this description is only for ease of understanding, and the form of S1, S2, S3, etc. does not limit the sequence of the steps.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Combination Figure 2 , Figure 3 As shown, an embodiment of the present invention provides an optical functional plate, which is made by co-extrusion in an extruder mold, and includes a light emitting layer 1, a main layer 2 and a light incident layer 3 connected in sequence, the main layer 2 includes a substrate 21 and a plurality of microporous structures 22 located in the substrate 21, and the distribution density of the microporous structure 22 gradually decreases from the center to the outer edge of the substrate 21.

[0037] Specifically, the optical functional plate is made by co-extrusion in an extruder mold, and the main layer 2 is located between the light-emitting layer 1 and the light-entering layer 3, and the whole is a three-layer composite integrated structure. And because the main layer 2 is made of expandable polystyrene (EPS) particles as the main raw material, it will foam to produce multiple microporous structures 22 during the preparation process. The foamed microporous structure 22 can cause the light to refract, reflect and scatter in different directions, thereby changing the path of the light, achieving full dispersion of the incident light to produce an optical diffusion effect, which can further enhance the uniform diffusion and concealment effect of the light entering the plate, and at the same time can reduce the use of diffusing agents and main materials. However, due to the inclusion of multiple microporous structures 22, the strength of the main layer 2 will be reduced to a certain extent, and the microporous structure 22 will also affect the bonding force between the main layer 2 and the light-emitting layer 1 and the light-entering layer 3.

[0038] Here, the distribution density of the microporous structure 22 gradually decreases from the center to the outer edge of the substrate 21 , that is, within the substrate 21 , the closer to the main layer 2 and the light incident layer 3 , the fewer the number of distributed microporous structures 22 .

[0039] Therefore, in the embodiment of the present invention, a plurality of microporous structures 22 are arranged in the main layer 2, and the positions of the microporous structures 22 are limited, so that the closer the position on the substrate 21 is to the light emitting layer 1 or the light incident layer 3, the fewer the microporous structures 22 are. This not only ensures that the microporous structures 22 can be beneficial to the diffusion of the light spot, thereby enhancing the light guiding property of the optical functional plate; at the same time, it avoids the problem of poor bonding and easy falling off between the main layer 2 and the light emitting layer 1 or the light incident layer 3 due to too many microporous structures 22 in contact with the light incident layer 3 or the light emitting layer 1, thereby improving the overall structural stability of the optical functional plate.

[0040] Among them, the substrate of the light output layer 1 and the substrate of the light input layer 3 both include one or more of polymethyl methacrylate PMMA, polystyrene PS, polycarbonate PC, polyethylene PE and polypropylene PP; the substrate of the main layer 2 includes expandable polystyrene or a mixture of expandable polystyrene and polystyrene.

[0041] During the preparation process, by limiting the melting temperature of the light entrance layer mixture and the light exit layer mixture in the mold to be 5-15°C higher than the melting temperature of the main layer mixture, and appropriately increasing the sheet pulling speed and pressing pressure, the light entrance layer mixture and the light exit layer mixture can penetrate into the micropores formed by the main layer mixture at the interface to a certain extent, so that the multi-layer materials at the interface can be better integrated, reducing the density of the microporous structure near the interface of the main layer, thereby forming a gradual density of the microporous structure of the main layer and ensuring the firmness of the three-layer material composite.

[0042] Thus, by setting different raw materials, EPS is creatively introduced into the optical functional board, and by utilizing its foaming properties, a microporous structure 22 is added to the optical functional board, thereby improving its light-guiding performance. At the same time, the weight of the EPS main layer under the same volume is much less than the weight of the main layer made of PMMA / PS / PC / PE / PP. Therefore, the optical functional board with a foaming structure provided by the present invention has a high degree of lightness and can be operated by a mechanical arm, which is not only convenient for transportation and assembly, but also improves production efficiency, and saves processing time and cost, which is conducive to large-scale promotion.

[0043] In addition, the microporous structure 22 can cause light to refract, reflect and scatter in different directions, which is beneficial to the diffusion of light. Its aperture has a great influence on the path of light, and the larger the aperture, the lighter the weight, but the strength of the board will also decrease accordingly. Therefore, in the embodiment of the present invention, preferably, the aperture range of the microporous structure 22 is 5-100 μm.

[0044] Relative to the light source, the light emitting layer 1 is located at the top layer of the optical functional board as the light emitting surface, and the light incident layer 3 is located at the bottom layer of the optical functional board as the light incident surface, directly contacting the light source, and both layers are functional layers. The main layer 2 made of EPS is located in the middle of the optical functional board as the main body, and there are many microporous structures 22, so it is set as the thickest layer, which can effectively reduce the amount of board material, reduce material costs, and better realize the thinness of the backlight module; and the larger layer thickness of the foamed microporous structure 22 can increase the light travel of the foamed structure, and further enhance the uniform diffusion effect of light entering the board. In actual production, the thickness of each layer can be flexibly adjusted within a reasonable range according to demand. In the implementation of the present invention, preferably, the thickness of the light emitting layer 1 and the light incident layer 3 accounts for 9%-11% of the total thickness of the optical functional board, wherein the total thickness of the optical functional board is 0.8-3.0mm.

[0045] Furthermore, a plurality of microstructures 4 of preset shapes are disposed on the surface of the side of the light emitting layer 1 facing away from the main layer 2 and / or the side of the light incident layer 3 facing away from the main layer 2 .

[0046] When the light-emitting layer 1, the main layer 2 and the light-incoming layer 3 are co-extruded into an optical functional plate through an extruder mold, a plurality of microstructures 4 of preset shapes are pressed on the upper surface and / or lower surface of the optical functional plate, so that the surface of the optical functional plate presents a non-smooth structure. This can avoid the interference problem caused by the combination with liquid crystal glass, leave a certain air layer, and thus enhance the brightening effect of the optical functional plate.

[0047] The preset shape includes at least one of a prism, a quadrangular pyramid, a hemispherical shape, a triangular prism, a triangular pyramid, a cone, a truncated cone, and a frosted shape, which can be selected according to actual needs. The bottom surface area and height of the microstructure 4 of the preset shape can be set arbitrarily. In the embodiment of the present invention, the height range of the microstructure 4 relative to the surface of the light incident layer 3 or the surface of the light output layer 1 is 0.1-20 μm.

[0048] Combination Figure 1 As shown, another embodiment of the present invention provides a method for preparing an optical functional plate, and preparing the optical functional plate as described above specifically includes the following steps:

[0049] S1. Feeding the light-emitting layer mixture, the main layer mixture and the light-entering layer mixture into three extruders respectively, wherein the main layer mixture includes expandable polystyrene or a mixture of expandable polystyrene and polystyrene; and setting the extruders to preset parameters, including metering pump pressure, feeding rate, main engine speed and extrusion temperature;

[0050] S2, after melting the mixed materials in the three extruders respectively, a composite sheet is formed by in-mold co-extrusion, wherein the melting temperature of the mixed materials in the light-emitting layer and the melting temperature of the mixed materials in the light-incoming layer are both 5-15° C. higher than the melting temperature of the mixed materials in the main layer;

[0051] S3, trimming the composite board according to the preset size, removing dust, cooling and shaping, and obtaining an optical functional board.

[0052] Specifically, in step S1, the parameters such as the temperature of the extruder, the pressure of the metering pump, the feeding rate and the main engine speed are set first, and then the preset mixed materials are weighed according to the ratio and mixed evenly in the mixer, and then put into the material port of the corresponding extruder. The three extruders work simultaneously, so that the molten material in the extruder is compounded in the mold and then extruded as a whole through the die, thereby preparing a multi-layer structure optical functional board, that is, the optical functional board is made by co-extrusion in the extruder mold.

[0053] The components of the light-emitting layer mixture include, by weight: 72-95% polystyrene, 4-10% silicone light diffuser, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, and 0.5-10% toughening agent;

[0054] The components of the main layer mixture include: 48-99% expandable polystyrene, 0-39.0% polystyrene, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, 0.5-5% toughening agent;

[0055] The components of the light-entering layer mixture include: 57-90% styrene, 9-30% silicone light diffuser, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, and 0.5-5% toughening agent.

[0056] In addition, the content of the diffusant in the light incident layer 3 is greater than that in the light emitting layer 1. This is because the light emitting layer 1 serves as the light emitting surface, and the addition of the diffusant can achieve the effect of shielding the foamed microporous structure 22 of the intermediate layer. At the same time, the diffusant can be used to adjust the emission angle of the light to ensure the delicacy and uniformity of the picture. The light incident layer 3 serves as the light incident surface, and the addition of the diffusant is used to diffuse the incident light source into the board, reduce light reflection, convert the point light source into a surface light source, and make the brightness of the picture uniform. The roles of the diffusant in the light emitting layer 1 and the light incident layer 3 are different, so adjusting the amount of the diffusant for different purposes can further improve the reaction accuracy, thereby increasing the optical effect of the optical functional board obtained.

[0057] The ultraviolet absorber, light stabilizer, antioxidant, antistatic agent and toughening agent used in the above-mentioned mixtures are as follows: the ultraviolet absorber is used to prevent the aging effect of ultraviolet rays on the board; the light stabilizer is used to eliminate or slow down the possibility of photochemical reactions and prevent or delay the process of light aging; the antioxidant is used to prevent oxygen from aging the board; the antistatic agent can reduce static electricity; the toughening agent can reduce the brittleness of the board; these additives are all conventional production substances and can be selected according to demand in actual production.

[0058] In step S2, after the mixed materials in the three extruders are melted, they are extruded into a mold for compounding and extrusion molding into a composite plate, that is, the light-emitting layer mixed materials, the main layer mixed materials and the light-incoming layer mixed materials that have been stirred evenly are respectively fed into corresponding feeding ports for high-temperature melting; the molten light-emitting layer mixed materials, the main layer mixed materials and the light-incoming layer mixed materials are compounded in the mold and extruded into a multi-layer substrate through the mold outlet, specifically comprising the steps of:

[0059] Select the corresponding mold according to the four-layer extrusion process, install the extruder head, and check the integrity of the extrusion equipment and each rotating part; adjust the temperature control meter to the working temperature, heat the barrel mold, and keep the temperature constant for 20-30 minutes after the temperature reaches the set value; the three extruder hoppers correspond to the light output layer 1, the main layer 2 and the light input layer 3, respectively, and the light output layer mixture, the main layer mixture and the light input layer mixture that have been stirred evenly are respectively fed to the feeding port of the corresponding substrate; replace the filter mesh of each machine, turn on the metering pump in turn, turn on the screw motor, set the metering pump pressure, feeding rate and main engine speed parameters, so that the plastic material passes through the barrel and plasticizes, the extruder extrudes the material, and cleans the die lip; adjust the metering pump, main line speed, pressure and other parameters, and start extrusion.

[0060] Since each layer uses plastic materials of different materials, there are certain differences in the temperature settings of the three extruders corresponding to the relevant materials, and the extruders corresponding to the light-emitting layer mixing and the light-incoming layer mixing both include vacuum exhaust devices, and the preset parameters also include vacuum degree. In an embodiment of the present invention, preferably, the vacuum degree is -0.08 to 0.1Mpa.

[0061] Since the base material of the main layer 2 includes EPS and PS, in order to increase the bonding force between the two, the temperature of co-extrusion needs to be controlled, and the extrusion speed and extrusion amount need to be set to match the temperature, so that the foamed microporous structure 22 can be produced evenly and controllably.

[0062] In an embodiment of the present invention, in order to achieve a gradually decreasing distribution density of the microporous structure 22 in the main layer 2 along the direction from the center to the outer edge of the substrate 21, the melting temperature of the light-emitting layer mixture and the melting temperature of the light-incoming layer mixture are set to be 5-15°C higher than the melting temperature of the main layer mixture. In this way, the light-incoming layer mixture and the light-emitting layer mixture can penetrate into the micropores formed by the main layer mixture at the interface to a certain extent. On the one hand, the microporous structure near the interface of the main layer can be reduced (that is, the microporous structure is filled with the light layer mixture and the light-incoming layer mixture), thereby forming a gradual density of the microporous structure of the main layer; on the other hand, the multi-layer materials at the interface can be better integrated to ensure the firmness of the three-layer material composite.

[0063] The main layer 2 needs to control the extrusion temperature, and the overall control temperature has an increasing trend, and the traction pressure, traction speed, line speed and extrusion amount that match the width and thickness need to be set. In the embodiment of the present invention, the temperature of the first zone feeding zone is 120-130°C, the temperature of the second zone preheating zone is 130-140°C, the temperature of the third zone heating zone is 140-150°C, the temperature of the fourth and fifth zones melting zone is 150-160°C, the temperature of the sixth and seventh zones plasticizing zone is 160-170°C, and the temperature of the eighth zone mixing zone is 170-180°C. The extrusion volume is generally 220-250kg / h, the thickness of the extruded sheet is generally 1.2-1.5mm, and the pressure of the traction roller is 0.3-0.5Mpa. When the width is 650-850mm, the line speed is 3.0-3.8m / min, and the traction speed is 3.06-3.86m / min; when the width is 850-1050mm, the line speed is 2.5-3.0m / min, and the traction speed is 2.56-3.06m / min; when the width is 1050-1250mm, the line speed is 2.0-2.5m / min, and the traction speed is 2.06-2.56m / min; when the width is 1250-1500mm, the line speed is 1.5-2.0m / min, and the traction speed is 1.56-2.06m / min. In actual production, you can choose according to your needs.

[0064] In step S3, the composite board is trimmed according to a preset size, and then dusted, cooled and shaped to obtain an optical functional board, which specifically includes:

[0065] According to production requirements, the width and thickness of the board are adjusted by cutting, and the stacking between the rollers is adjusted; the composite board is trimmed and dusted, and the composite board is gradually transported to the back section of the production line through a conveying device, and gradually cooled and shaped during traction to obtain the optical functional board.

[0066] Of course, to facilitate storage and transportation, a cutting unit can be used at the back end of the production line to cut the products into the required second preset size, and a robotic arm can be used to grab and stack them, and then they can be cleaned, packaged, and put into storage.

[0067] The preparation method of the optical functional plate provided by the present invention adopts expandable polystyrene as the substrate of the main layer 2, so that the prepared optical functional plate has a foamed microporous structure 22. At the same time, during the plate processing process, the particle size of the pores in the foamed substrate layer, the thickness of the substrate layer and the processing uniformity are controlled by controlling the processing temperature, extrusion amount, extrusion line speed and other parameters of the main layer extruder and adjusting the content of expandable polystyrene particles. At the same time, the problem of poor bonding between the expandable polystyrene material and other materials and easy peeling is avoided.

[0068] Compared with the traditional optical functional board, the preparation method of the optical functional board provided by the present invention has a simple process and uses less materials, which can reduce the consumption of raw materials and production costs. It also highly combines expandable polystyrene with styrene to introduce the foaming material into the optical functional board, which provides a new idea for the lightweight of the optical functional board. At the same time, the optical functional board prepared by the present invention can further improve the uniform diffusion and concealment effect of light entering the board by using the microporous structure 22 in the main layer 2, and add diffusion components in the light emitting layer 1 and the light input layer 3 to increase the amount of light entering the light input surface and the uniformity of the light output on the light output surface. At the same time, the microporous structure 22 of the middle main layer has a better shielding effect, which enhances the display effect of the light output and expands the application environment in backlight and lighting products. .

[0069] Furthermore, the method for preparing the optical functional plate provided by the present invention further comprises the following steps before post-processing the composite plate in step S3:

[0070] S4. Using a roller with a microstructure 4 of a preset shape engraved on the surface, hot-press the upper and lower surfaces of the composite board into corresponding microstructures 4.

[0071] The roller is generally a roller with a microstructure 4 of a preset shape engraved on the surface. The composite sheet is placed on a workbench, and the upper surface and / or lower surface of the composite sheet is hot-pressed into a microstructure 4 of a preset shape by rolling the roller. Of course, the composite sheet can also be placed between the upper roller and the lower roller, and the upper surface and / or lower surface of the composite sheet can be hot-pressed into a composite sheet with a microstructure 4 of a preset shape by rotating the upper roller and the lower roller.

[0072] The above steps S1, S2, S3 and S4 are integrated online production, which reduces the equipment investment and process loss of processing individual materials separately, reduces manpower investment and product operation defect rate, and improves production automation efficiency.

[0073] Thus, a plurality of microstructures 4 of preset shapes are pressed on the upper surface and / or lower surface of the optical functional plate, and light is better refracted and reflected when passing through, thereby increasing the uniform diffusion of light and avoiding interference problems caused by matching with liquid crystal glass, thereby improving the brightening effect of the optical functional plate.

[0074] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods for which specific conditions are not specified in the following examples are usually based on the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are calculated by weight.

[0075] Example 1

[0076] This embodiment provides a method for preparing an optical functional plate, which comprises the following steps:

[0077] 1) Material preparation: After drying the required plastic particles of the light output layer 1, the main layer 2 and the light input layer 3 at 50-60°C for 2-4 hours, the plastic particles and additives are mixed according to a certain ratio, and stirred evenly in a mixer to form a mixture for use;

[0078] Among them, the light-emitting layer mixture is composed of the following components by weight: 84.7% PS, 8.0% silicone light diffuser, 0.2% ultraviolet absorber, 0.2% light stabilizer, 0.4% antioxidant, 0.5% antistatic agent, and 6% toughening agent; the main layer mixture is composed of the following components by weight: 97.7% EPS, 0.2% ultraviolet absorber, 0.2% light stabilizer, 0.4% antioxidant, 0.5% antistatic agent, and 1.0% toughening agent; the light-incoming layer mixture is composed of the following components by weight: 80.7% PS, 13.0% silicone light diffuser, 0.2% ultraviolet absorber, 0.2% light stabilizer, 0.4% antioxidant, 0.5% antistatic agent, and 5% toughening agent.

[0079] 2) Mold matching and equipment inspection: Select the corresponding mold according to the four-layer extrusion process, install the extruder head, and check the integrity of the extrusion equipment and each rotating part;

[0080] 3.) Heating: Adjust the temperature control meter to the working temperature, heat the barrel mold, and keep the temperature constant for 20-30 minutes after the temperature reaches the set value;

[0081] 4) Extrusion: The hoppers of the three extruders correspond to the light-emitting layer 1, the main body layer 2 and the light-entering layer 3 respectively. The mixed materials of each substrate layer after being stirred evenly are respectively fed to the feeding port of the corresponding substrate layer; the filter mesh of each machine (300 mesh, 400 mesh) is replaced, the metering pump is turned on in turn, the screw motor is turned on, and the parameters such as the metering pump pressure, feeding rate and main engine speed are set, so that the plastic material passes through the barrel and is plasticized, and the extruder extrude the material and clean the die lip; the metering pump, main line speed, pressure and other parameters are adjusted to start extrusion;

[0082] Each extruder is divided into eight heating zones. Specifically, the temperature of the first zone of the extruder for the light-emitting layer 1 is 170-185°C, the temperature of the second zone preheating zone is 185-195°C, the temperature of the third zone heating zone is 195-205°C, the temperature of the fourth and fifth zones melting zone is 205-215°C, the temperature of the sixth and seventh zones plasticizing zone is 215-220°C, and the temperature of the eighth zone mixing zone plasticizing zone is 220-225°C; the temperature of the first zone of the extruder for the main layer 2 is 120-130°C, the temperature of the second zone preheating zone is 130-140°C, and the temperature of the third zone heating zone is 205-215°C. The temperature of the fourth and fifth melting zones is 140-150℃, the temperature of the sixth and seventh plasticizing zones is 150-160℃, the temperature of the eighth mixing and plasticizing zone is 170-180℃; the temperature of the first zone of the light input layer 3 extruder is 170-185℃, the temperature of the second zone preheating zone is 185-195℃, the temperature of the third zone heating zone is 195-205℃, the temperature of the fourth and fifth melting zones is 205-215℃, the temperature of the sixth and seventh plasticizing zones is 215-220℃, and the temperature of the eighth mixing and plasticizing zone is 220-225℃.

[0083] The extruders corresponding to the light-emitting layer 1 and the light-entering layer 3 are equipped with vacuum exhaust devices, and the vacuum degree is controlled at -0.08 to 0.1Mpa. The main layer 2 extruder does not have a vacuum exhaust device. In this embodiment, the preset shape is a frosted type, and the preset conditions are: mold temperature 190-200℃; upper frosted structure roller temperature 100-115℃, middle frosted structure roller temperature 95-105℃, mirror structure roller temperature 80-90℃; pump front pressure 3.5±0.5Mpa; under the premise of unchanged length and width, when the normal speed is adjusted to 2.0m / min, the thickness changes by 0.1mm.

[0084] 5) Compounding and pressing: After the materials in the three extruders are melted, they are extruded into a mold for compounding, and a composite plate is extruded through the die outlet; the upper and lower surfaces of the plate are hot-pressed into a frosted microstructure 4 using a roller with a frosted microstructure 4 engraved on the surface;

[0085] 6) Dust removal, cooling and traction: According to production requirements, adjust the width and thickness of the plate by cutting, and adjust the stacking between the rollers; remove dust after trimming the multi-layer substrate, and gradually convey the plate to the back of the production line through the conveyor device, and gradually cool and shape it during traction;

[0086] 7) Cutting and packaging: The sheets are gradually transported to the cutting unit at the rear of the production line through the conveying device of the traction unit, cut into the required size, and grabbed and stacked by a robotic arm, and then cleaned, packaged and stored.

[0087] The total thickness of the optical functional plate prepared in this embodiment is 1.5 mm, wherein the thickness of the light emitting layer 1 and the light incident layer 3 are both 0.15 mm, the thickness of the main layer 2 is 1.2 mm, and the height of the microstructure 4 is 0.1 μm.

[0088] This embodiment 2

[0089] The difference between this embodiment and embodiment 1 is that:

[0090] In step 1), the light-emitting layer mixture is composed of the following components by weight: 83.7% PS, 10.0% silicone light diffuser, 0.2% ultraviolet absorber, 0.2% light stabilizer, 0.4% antioxidant, 0.5% antistatic agent, and 5% toughening agent; the main layer mixture is composed of the following components by weight: 57.7% EPS, 40.0% PS, 0.2% ultraviolet absorber, 0.2% light stabilizer, 0.4% antioxidant, 0.5% antistatic agent, and 1.0% toughening agent; the light-incoming layer mixture is composed of the following components by weight: 81.7% PMMA, 12.0% silicone light diffuser, 0.2% ultraviolet absorber, 0.2% light stabilizer, 0.4% antioxidant, 0.5% antistatic agent, and 5% toughening agent;

[0091] 5) Composite and plate pressing: After the materials in the three extruders are melted, they are extruded into the mold for composite, and the composite plate is extruded through the die outlet; the lower surface of the plate is hot-pressed into a prismatic microstructure 4 and the upper surface is hot-pressed into a frosted microstructure 4 (as shown in the attached figure) by a roller with prismatic and frosted microstructures 4 engraved on the surface. Figure 3 shown);

[0092] The other steps and parameters are the same as those in Example 1.

[0093] The total thickness of the optical functional plate prepared in this embodiment is 1.2 mm, wherein the thicknesses of the light emitting layer 1 and the light incident layer 3 are both 0.13 mm, the thickness of the main layer 2 is 0.94 mm, and the height of the microstructure 4 is 20 μm.

[0094] Embodiment 3

[0095] The difference between this embodiment and embodiment 1 is that:

[0096] In step 1), the light-emitting layer mixture is composed of the following components by weight: 72% PS, 15% silicone light diffuser, 2% ultraviolet absorber, 2% light stabilizer, 2% antioxidant, 2% antistatic agent, and 10% toughening agent; the main layer mixture is composed of the following components by weight: 48% EPS, 39% PS, 2% ultraviolet absorber, 2% light stabilizer, 2% antioxidant, 2% antistatic agent, and 5% toughening agent; the light-incoming layer mixture is composed of the following components by weight: 57% PMMA, 30% silicone light diffuser, 2% ultraviolet absorber, 2% light stabilizer, 2% antioxidant, 2% antistatic agent, and 5% toughening agent;

[0097] The other steps and parameters are the same as those in Example 1.

[0098] This embodiment 4

[0099] The difference between this embodiment and embodiment 1 is that:

[0100] In step 1), the light-emitting layer mixture is composed of the following components by weight: 95% PS, 4% silicone light diffuser, 0.1% ultraviolet absorber, 0.1% light stabilizer, 0.1% antioxidant, 0.2% antistatic agent, and 0.5% toughening agent; the main layer mixture is composed of the following components by weight: 99% EPS, 0% PS, 0.1% ultraviolet absorber, 0.1% light stabilizer, 0.1% antioxidant, 0.2% antistatic agent, and 0.5% toughening agent; the light-incoming layer mixture is composed of the following components by weight: 90% PMMA, 9% silicone light diffuser, 0.1% ultraviolet absorber, 0.1% light stabilizer, 0.1% antioxidant, 0.2% antistatic agent, and 0.5% toughening agent;

[0101] The other steps and parameters are the same as those in Example 1.

[0102] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. An optical functional plate, characterized in that: The invention comprises a light emitting layer (1), a main layer (2) and a light incident layer (3) which are connected in sequence, wherein the main layer (2) comprises a substrate (21) and a plurality of microporous structures (22) located in the substrate (21), and the distribution density of the microporous structures (22) gradually decreases along the direction from the center to the outer edge of the substrate (21).

2. The optical functional plate according to claim 1, wherein: The pore size of the microporous structure (22) is 5-100 μm.

3. The optical functional plate according to claim 1, wherein: The thickness of the light emitting layer (1) and the light incident layer (3) both accounts for 9% to 11% of the total thickness of the optical functional plate.

4. The optical functional plate according to claim 3, characterized in that: The total thickness of the optical functional plate is 0.8-3.0 mm.

5. The optical functional plate according to any one of claims 1 to 4, characterized in that: A plurality of microstructures (4) of preset shapes are provided on one side of the light emitting layer (1) facing away from the main layer (2) and / or on one side of the light incident layer (3) facing away from the main layer (2).

6. The optical functional plate according to claim 5, characterized in that: The preset shape includes at least one of a prism type, a quadrangular pyramid type, a hemisphere type, a triangular prism type, a triangular pyramid type, a cone type, a truncated cone type and a frosted type.

7. A method for preparing an optical functional plate, for preparing the optical functional plate according to any one of claims 1 to 6, characterized in that: The steps include: Feeding the light-emitting layer mixture, the main layer mixture and the light-incoming layer mixture into three extruders respectively, wherein the main layer mixture includes expandable polystyrene or a mixture of expandable polystyrene and polystyrene; After the mixed materials in the three extruders are melted respectively, a composite sheet is formed by in-mold co-extrusion, wherein the melting temperature of the mixed materials in the light-emitting layer and the melting temperature of the mixed materials in the light-incoming layer are both 5-15° C. higher than the melting temperature of the mixed materials in the main body layer; The composite board is trimmed according to a preset size, and then dusted, cooled and shaped to obtain the optical functional board.

8. The method for preparing an optical functional plate according to claim 7, wherein: After the mixed materials in the three extruders are melted respectively and the composite sheet is formed by in-mold co-extrusion, the following steps are also included: The corresponding microstructure (4) is hot pressed onto the upper surface and / or lower surface of the composite board by a roller having a microstructure (4) of a preset shape engraved on the surface.

9. The method for preparing an optical functional plate according to claim 7, wherein: By weight, The components of the light-emitting layer mixture include: 72-95% polystyrene, 4-10% silicone light diffuser, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, and 0.5-10% toughening agent; The components of the main layer mixture include: 48-99% expandable polystyrene, 0-39.0% polystyrene, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, 0.5-5% toughening agent; The components of the light incident layer mixture include: 57-90% polystyrene, 9-30% silicone light diffuser, 0.1-2% ultraviolet absorber, 0.1-2% light stabilizer, 0.1-2% antioxidant, 0.2-2% antistatic agent, and 0.5-5% toughening agent.

10. The method for preparing an optical functional plate according to claim 7, wherein: The extruders corresponding to the light-emitting layer mixture and the light-incoming layer mixture both include a vacuum exhaust device, and the vacuum degree of the vacuum exhaust device is -0.08 to 0.1Mpa.

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