Yellowing-resistant PS diffusion plate and manufacturing method thereof

Abstract

The invention discloses an anti-yellowing PS diffusion plate and a manufacturing method thereof, and relates to the technical field of diffusion plate materials. The anti-yellowing PS diffusion plate comprises an upper diffusion layer, a lower diffusion layer and a middle quantum dot layer, the upper diffusion layer, the lower diffusion layer and the middle quantum dot layer are manufactured through in-mold three-layer co-extrusion molding, and the diffusion layers comprise styrene crosslinked microspheres, ethylene glycol bis (propionitrile) ether derivatives and polystyrene. Styrene crosslinked microspheres and ethylene glycol bis (propionitrile) ether derivatives cannot be completely compatible in polystyrene, formed diffusion particles exist in the form of a microsphere dispersion phase, the effect of light scattering particles is achieved, the light transmittance is guaranteed, meanwhile, the diffusion particles existing in the diffusion plate have the high barrier capacity for water vapor and oxygen, and the diffusion effect of the diffusion plate is improved. Therefore, the diffusion plate has yellowing resistance and does not affect the optical characteristics of the quantum dot layer.

Description

Technical Field

[0001] The invention relates to the technical field of diffusion plate materials, in particular to a yellowing-resistant PS diffusion plate and a manufacturing method thereof. Background Art

[0002] The diffusion plate uses the continuous refraction, reflection and scattering of light between chemical particles and resin. While covering the light source and the dazzling light source, it can make the light source emit uniform, soft and beautiful light, achieving a comfortable effect of light transmission and opacity. Compared with the traditional CCFL backlight source, LED backlight has many advantages such as high color gamut, high brightness, long life, energy saving and environmental protection, and real-time color control. The high color gamut LED backlight makes the screens of electronic products such as TVs, mobile phones, and tablets that use it have more vivid colors and higher color reproduction. In order to make the display color more perfect, richer in color and closer to the color of the real world, R&D personnel have been committed to finding ways to increase the color gamut value of LED backlight display screens.

[0003] The invention patent with announcement number CN114895492A discloses a quantum dot diffusion plate, including a chain dot layer, an upper surface and a lower surface covered with a protective layer, which has a high brightness effect, thereby reducing the overall cost of the backlight module. Although it has a high brightness and can meet the needs of the new display field, the diffusion plate still has the disadvantage of poor barrier ability to water vapor and oxygen, resulting in insufficient yellowing resistance. Summary of the invention

[0004] The object of the present invention is to provide a yellowing-resistant PS diffuser plate and a method for manufacturing the same, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a yellowing-resistant PS diffusion plate, comprising two diffusion layers, an upper diffusion layer and an intermediate quantum dot layer; the diffusion layer comprises the following components in mass percentage: 4-8% of styrene microspheres, 5-8% of ethylene glycol bis(propionitrile) ether derivatives, and the rest being polystyrene; the quantum dot layer comprises the following components in mass percentage: 1-3% of green light perovskite, 4-6% of masterbatch, and the rest being polystyrene.

[0006] Preferably, the styrene cross-linked microspheres are prepared by the reaction of polystyrene, methyl methacrylate and butyl acrylate; and the ethylene glycol bis(propionitrile) ether derivative is prepared by the reaction of ethylene glycol bis(propionitrile) ether and ethylene-vinyl alcohol copolymer.

[0007] Preferably, the diffusion layer comprises the following components in mass percentage: 5.5-6.5% of styrene microspheres, 5.8-6.4% of ethylene glycol bis(propionitrile) ether derivatives, and the rest polystyrene; the quantum dot layer comprises the following components in mass percentage: 1.8-2.2% of green light perovskite, 4.8-5.2% of masterbatch, and the rest polystyrene.

[0008] Preferably, the thickness of the yellowing-resistant PS diffuser plate is 1.6-1.8 mm; the thickness of the diffusion layer is 6-8% of the thickness of the yellowing-resistant PS diffuser plate.

[0009] Preferably, the masterbatch comprises the following components in percentage by mass: 14-18% of a light diffuser and the rest of polystyrene; the light diffuser is silicon dioxide; and the masterbatch is prepared by mixing the components and granulating them in a twin-screw granulator.

[0010] Preferably, the green perovskite is green quantum dots with a particle size of 2 to 3 nm.

[0011] Preferably, the method for manufacturing the yellowing-resistant PS diffuser plate is to prepare the styrene microspheres, ethylene glycol bis(propionitrile) ether derivatives and polystyrene in the diffusion layer, and the green light perovskite, masterbatch and polystyrene in the quantum dot layer according to the mass percentage ratio, and form a diffusion layer sheet layer, a quantum dot layer sheet layer and a diffusion layer sheet layer which are sequentially laminated and composited together through in-mold co-extrusion molding, and the extrusion speed is 2.8~3.2m / min to obtain the yellowing-resistant PS diffuser plate.

[0012] Preferably, the preparation method of the styrene microspheres is as follows: in a nitrogen atmosphere, ethanol, deionized water and dispersant polyvinyl pyrrolidone are mixed, stirred evenly, heated to 70-72°C, styrene and initiator azobisisobutyronitrile are added, reacted for 2-3 hours, methyl methacrylate, butyl acrylate and crosslinking agent trimethylolpropane trimethacrylate are added, reacted for 14-16 hours, centrifuged and then dispersed and precipitated with ethanol, filtered and washed with ethanol and deionized water for 3-5 times, and finally vacuum dried to constant weight to obtain styrene microspheres.

[0013] Preferably, the mass ratio of the ethanol, deionized water, dispersant, styrene, initiator, methyl methacrylate, butyl acrylate and crosslinking agent is 65-75:6:1.2:15:0.8:5:6:2.

[0014] Preferably, the preparation method of the ethylene glycol bis(propionitrile) ether derivative is as follows: under a nitrogen atmosphere, ethylene-vinyl acetate copolymer, toluene and ethylene glycol bis(propionitrile) ether are mixed in a mass ratio of 1-1.5:15:1-1.2, heated to 78-82°C in a water bath, and concentrated sulfuric acid in an amount of 0.03-0.06 times the mass of the ethylene-vinyl acetate copolymer is added dropwise at a rate of 1-3 mL / min, and the mixture is kept warm for 2-3 hours, cooled to 68-72°C, and the pH is adjusted to 6.8-7.2 with a standard sodium hydroxide-ethanol solution, vacuum filtered, washed with anhydrous ethanol and deionized water for 3-5 times in sequence, and finally dried to obtain the ethylene glycol bis(propionitrile) ether derivative.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: The yellowing-resistant PS diffusion plate of the present invention comprises two diffusion layers, an upper diffusion layer and a quantum dot layer in the middle. The upper diffusion layers and the upper diffusion layer and the quantum dot layer in the middle are manufactured by three-layer co-extrusion molding in a mold, and the quantum dots are placed in the middle layer. The two diffusion layers are used to block water vapor and oxygen, so as to obtain a PS diffusion plate with a long life and yellowing resistance.

[0016] The diffusion layer includes styrene cross-linked microspheres, ethylene glycol bis (propionitrile) ether derivatives and polystyrene. The styrene cross-linked microspheres are prepared by the reaction of polystyrene, methyl methacrylate and butyl acrylate. The ethylene glycol bis (propionitrile) ether derivatives are prepared by the reaction of ethylene glycol bis (propionitrile) ether and ethylene-vinyl alcohol copolymer. The styrene cross-linked microspheres and ethylene glycol bis (propionitrile) ether derivatives are not completely compatible in polystyrene. The formed diffusion particles exist in the form of microsphere dispersed phase and play the role of light scattering particles. While ensuring the light transmittance, the diffusion particles existing in the diffusion plate have a high barrier capacity to water vapor and oxygen, so that the diffusion plate has yellowing resistance and does not affect the optical properties of the quantum dot layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the yellowing-resistant PS diffusion plate of the present invention.

[0018] Figure 2 It is a bar graph of oxygen permeability coefficients of Examples 1-3 of the present invention and Comparative Examples 1-3.

[0019] Figure 3 It is a bar graph of water vapor transmission rates of Examples 1-3 of the present invention and Comparative Examples 1-3. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] The preparation method of green perovskite (CH3NH3PbBr3 quantum dots) used in the present invention is prepared by referring to the method of Example 3 in application number CN104861958 A; the visible light absorber VL-580 is produced by Jiangxi Lotte Chemical Co., Ltd.; and the light diffuser silica is produced by Anhui Xinjingtong New Materials Technology Co., Ltd.

[0022] The master batch of the present invention is prepared by mixing silicon dioxide as a light diffusion agent with polystyrene and granulating the mixture with a twin-screw granulator.

[0023] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the yellowing-resistant PS diffusion plates prepared in the examples and comparative examples as follows: Example 1

[0024] The mass percentages of the components in each layer in this embodiment are: Masterbatch: 14% light diffuser, the rest is polystyrene; Diffusion layer: 5.5% styrene microspheres, 5.8% ethylene glycol bis(propionitrile) ether derivative, the rest polystyrene, the rest polystyrene; Quantum dot layer: 1.8% green light perovskite, 4.8% masterbatch, and the rest is polystyrene The preparation method of the yellowing-resistant PS diffusion plate in this embodiment is as follows: (1) Under a nitrogen atmosphere, ethanol, deionized water and dispersant polyvinyl pyrrolidone were mixed and stirred evenly, then the temperature was raised to 70°C, styrene and initiator azobisisobutyronitrile were added, and after reacting for 2 hours, methyl methacrylate, butyl acrylate and crosslinking agent trimethylolpropane trimethacrylate were added. The mass ratio of ethanol, deionized water, dispersant, styrene, initiator, methyl methacrylate, butyl acrylate and crosslinking agent was 65:6:1.2:15:0.8:5:6:2. The mixture was reacted for 14 hours, centrifuged and then dispersed and precipitated with ethanol, filtered and washed with ethanol and deionized water for 3 times, and finally vacuum dried to constant weight to obtain styrene microspheres. (2) Under a nitrogen atmosphere, ethylene-vinyl acetate copolymer, toluene and ethylene glycol bis(propionitrile) ether were mixed in a mass ratio of 1:15:1, heated in a water bath to 78-82°C, and concentrated sulfuric acid (0.03 times the mass of ethylene-vinyl acetate copolymer) was added dropwise at a rate of 1 mL / min, and the mixture was kept warm for 2 h. The mixture was cooled to 68°C, and the pH was adjusted to 6.8 with a standard sodium hydroxide-ethanol solution. The mixture was vacuum filtered, washed with anhydrous ethanol and deionized water for three times, and finally dried to obtain an ethylene glycol bis(propionitrile) ether derivative. (3) The styrene microspheres, ethylene glycol bis(propylene nitrile) ether derivatives and polystyrene in the diffusion layer, the green light perovskite, masterbatch and polystyrene in the quantum dot layer are prepared according to the mass percentage ratio, and the diffusion layer sheet layer, quantum dot layer sheet layer and diffusion layer sheet layer are formed by in-mold co-extrusion molding. The extrusion speed is 2.8m / min to obtain a yellowing-resistant PS diffusion plate. Example 2

[0025] The mass percentages of the components in each layer in this embodiment are: Masterbatch: 16% light diffuser, the rest is polystyrene; Diffusion layer: 6% styrene microspheres, 6.2% ethylene glycol bis(propionitrile) ether derivative, the rest polystyrene, the rest polystyrene; Quantum dot layer: 2% green light perovskite, 4.4% masterbatch, and the rest is polystyrene The preparation method of the yellowing-resistant PS diffusion plate in this embodiment is as follows: (1) Under a nitrogen atmosphere, ethanol, deionized water and dispersant polyvinyl pyrrolidone were mixed and stirred evenly, then heated to 71°C, styrene and initiator azobisisobutyronitrile were added, and after reacting for 2.5 hours, methyl methacrylate, butyl acrylate and crosslinking agent trimethylolpropane trimethacrylate were added. The mass ratio of ethanol, deionized water, dispersant, styrene, initiator, methyl methacrylate, butyl acrylate and crosslinking agent was 70:6:1.2:15:0.8:5:6:2. The mixture was reacted for 15 hours, centrifuged and then dispersed and precipitated with ethanol, filtered and washed with ethanol and deionized water for 4 times, and finally vacuum dried to constant weight to obtain styrene microspheres. (2) Under a nitrogen atmosphere, ethylene-vinyl acetate copolymer, toluene and ethylene glycol bis(propionitrile) ether were mixed in a mass ratio of 1.25:15:1.1, heated to 80°C in a water bath, and concentrated sulfuric acid (0.045 times the mass of ethylene-vinyl acetate copolymer) was added dropwise at a rate of 2 mL / min, and the mixture was kept warm for 2.5 h. The mixture was cooled to 70°C, and the pH was adjusted to 7.0 with a standard sodium hydroxide-ethanol solution. The mixture was vacuum filtered, washed four times with anhydrous ethanol and deionized water, and dried to obtain an ethylene glycol bis(propionitrile) ether derivative. (3) The styrene microspheres, ethylene glycol bis(propylene nitrile) ether derivatives and polystyrene in the diffusion layer, the green light perovskite, masterbatch and polystyrene in the quantum dot layer are prepared according to the mass percentage ratio, and the diffusion layer sheet layer, quantum dot layer sheet layer and diffusion layer sheet layer are formed by in-mold co-extrusion molding. The extrusion speed is 3.0 m / min to obtain a yellowing-resistant PS diffusion plate. Example 3

[0026] The mass percentages of the components in each layer in this embodiment are: Masterbatch: 18% light diffuser, the rest is polystyrene; Diffusion layer: 6.5% styrene microspheres, 6.4% ethylene glycol bis(propionitrile) ether derivative, the rest polystyrene, the rest polystyrene; Quantum dot layer: 2.2% green light perovskite, 5.2% masterbatch, and the rest is polystyrene The preparation method of the yellowing-resistant PS diffusion plate in this embodiment is as follows: (1) Under a nitrogen atmosphere, ethanol, deionized water and dispersant polyvinyl pyrrolidone were mixed and stirred evenly, then heated to 72°C, styrene and initiator azobisisobutyronitrile were added, and after reacting for 3 hours, methyl methacrylate, butyl acrylate and crosslinking agent trimethylolpropane trimethacrylate were added. The mass ratio of ethanol, deionized water, dispersant, styrene, initiator, methyl methacrylate, butyl acrylate and crosslinking agent was 75:6:1.2:15:0.8:5:6:2. The mixture was reacted for 16 hours, centrifuged, dispersed and precipitated with ethanol, filtered and washed with ethanol and deionized water for 5 times, and finally vacuum dried to constant weight to obtain styrene microspheres. (2) Under a nitrogen atmosphere, ethylene-vinyl acetate copolymer, toluene and ethylene glycol bis(propionitrile) ether were mixed in a mass ratio of 1.5:15:1.2, heated to 82°C in a water bath, and concentrated sulfuric acid (0.06 times the mass of ethylene-vinyl acetate copolymer) was added dropwise at a rate of 3 mL / min, and the mixture was kept warm for 3 h. The mixture was cooled to 72°C, and the pH value was adjusted to 7.2 with a standard sodium hydroxide-ethanol solution. The mixture was vacuum filtered, washed with anhydrous ethanol and deionized water for 5 times, and finally dried to obtain an ethylene glycol bis(propionitrile) ether derivative. (3) The styrene microspheres, ethylene glycol bis(propylene nitrile) ether derivatives and polystyrene in the diffusion layer, the green light perovskite, masterbatch and polystyrene in the quantum dot layer are prepared according to the mass percentage ratio, and the diffusion layer sheet layer, quantum dot layer sheet layer and diffusion layer sheet layer are formed by in-mold co-extrusion molding. The extrusion speed is 3.2m / min to obtain a yellowing-resistant PS diffusion plate.

[0027] Comparative Example 1 The manufacturing method of comparative example 1 is the same as that of example 2. The difference between the yellowing-resistant PS diffusion plate and example 2 is that the diffusion layer is only styrene cross-linked microspheres and polystyrene.

[0028] Comparative Example 2 The manufacturing method of comparative example 2 is the same as that of example 2. The difference between the yellowing-resistant PS diffusion plate and example 2 is that the diffusion layer is only ethylene glycol bis(propionitrile) ether derivative and polystyrene.

[0029] Comparative Example 3 The manufacturing method of comparative example 3 is the same as that of example 2. The difference between the yellowing-resistant PS diffusion plate and example 2 is that the diffusion layer is only polystyrene.

[0030] The structure of the yellowing-resistant PS diffusion plate of the present invention is as follows Figure 1 As shown, A and C are diffusion layers, and B is a quantum dot layer.

[0031] Figure 2 The oxygen permeability coefficient bar graphs of Examples 1-3 and Comparative Examples 1-3 are shown in FIG. Figure 3 The water vapor transmission rate bar graphs of Examples 1-3 and Comparative Examples 1-3 of the present invention are shown in the figure. It can be found from the experimental data that the yellowing-resistant PS diffuser plate manufactured by the present invention has relatively excellent oxygen permeability coefficient and water vapor transmission rate, indicating that the styrene cross-linked microspheres and ethylene glycol bis(propionitrile) ether derivatives prepared in the present invention are not completely compatible in polystyrene, and the formed diffusion particles exist in the form of microsphere dispersed phase, playing the role of light scattering particles. While ensuring the light transmittance, the diffusion particles present in the diffuser plate have a high barrier capacity to water vapor and oxygen, so that the diffuser plate has yellowing resistance and does not affect the optical properties of the quantum dot layer. Obviously, the above embodiments are merely examples for clearly illustrating the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. However, these obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A yellowing-resistant PS diffuser plate, characterized in that: It includes two diffusion layers, an upper diffusion layer and a quantum dot layer in the middle; the diffusion layer includes the following components in mass percentage: 4-8% styrene microspheres, 5-8% ethylene glycol bis(propionitrile) ether derivatives, and the rest polystyrene; the quantum dot layer includes the following components in mass percentage: 1-3% green light perovskite, 4-6% masterbatch, and the rest polystyrene.

2. The yellowing-resistant PS diffuser plate according to claim 1, characterized in that: The styrene cross-linked microspheres are prepared by the reaction of polystyrene, methyl methacrylate and butyl acrylate; the ethylene glycol bis(propionitrile) ether derivative is prepared by the reaction of ethylene glycol bis(propionitrile) ether and ethylene-vinyl alcohol copolymer.

3. The yellowing-resistant PS diffuser plate according to claim 1, characterized in that: The diffusion layer includes the following components in mass percentage: 5.5-6.5% of styrene microspheres, 5.8-6.4% of ethylene glycol bis(propionitrile) ether derivatives, and the rest is polystyrene; the quantum dot layer includes the following components in mass percentage: 1.8-2.2% of green light perovskite, 4.8-5.2% of masterbatch, and the rest is polystyrene.

4. The yellowing-resistant PS diffuser plate according to claim 1, characterized in that: The thickness of the yellowing-resistant PS diffusion plate is 1.6-1.8 mm; the thickness of the diffusion layer is 6-8% of the thickness of the yellowing-resistant PS diffusion plate.

5. The yellowing-resistant PS diffuser plate according to claim 1, characterized in that: The masterbatch comprises the following components in mass percentage: 14-18% of a light diffuser and the rest of polystyrene; the light diffuser is silicon dioxide; and the masterbatch is prepared by mixing the components and then granulating them in a twin-screw granulator.

6. The yellowing-resistant PS diffuser plate according to claim 1, characterized in that: The green perovskite is a green quantum dot with a particle size of 2 to 3 nm.

7. A method for manufacturing a yellowing-resistant PS diffuser plate as claimed in claim 1, characterized in that: The styrene microspheres, ethylene glycol bis(propionitrile) ether derivatives and polystyrene in the diffusion layer, the green light perovskite, masterbatch and polystyrene in the quantum dot layer are prepared according to mass percentage, and are formed by in-mold co-extrusion molding to form a diffusion layer sheet layer, a quantum dot layer sheet layer and a diffusion layer sheet layer that are laminated and composited together in sequence. The extrusion speed is 2.8~3.2m / min to obtain a yellowing-resistant PS diffusion plate.

8. The method for manufacturing a yellowing-resistant PS diffusion plate according to claim 7, characterized in that: The preparation method of the styrene microspheres is as follows: in a nitrogen atmosphere, ethanol, deionized water and dispersant polyvinyl pyrrolidone are mixed, stirred evenly, heated to 70-72° C., styrene and initiator azobisisobutyronitrile are added, reacted for 2-3 hours, methyl methacrylate, butyl acrylate and crosslinking agent trimethylolpropane trimethacrylate are added, reacted for 14-16 hours, centrifuged, dispersed and precipitated with ethanol, filtered and washed with ethanol and deionized water for 3-5 times, and finally vacuum dried to constant weight to obtain styrene microspheres.

9. The method for manufacturing a yellowing-resistant PS diffusion plate according to claim 8, characterized in that: The mass ratio of the ethanol, deionized water, dispersant, styrene, initiator, methyl methacrylate, butyl acrylate and crosslinking agent is 65-75:6:1.2:15:0.8:5:6:

2.

10. The method for manufacturing a yellowing-resistant PS diffusion plate according to claim 7, characterized in that: The preparation method of the ethylene glycol bis(propionitrile) ether derivative is as follows: in a nitrogen atmosphere, ethylene-vinyl acetate copolymer, toluene and ethylene glycol bis(propionitrile) ether are mixed in a mass ratio of 1-1.5:15:1-1.2, heated to 78-82° C. in a water bath, and concentrated sulfuric acid in an amount of 0.03-0.06 times the mass of the ethylene-vinyl acetate copolymer is added dropwise at a rate of 1-3 mL / min, and the mixture is kept warm for 2-3 hours, cooled to 68-72° C., the pH value is adjusted to 6.8-7.2 with a standard sodium hydroxide-ethanol solution, vacuum filtered, washed with anhydrous ethanol and deionized water for 3-5 times in sequence, and finally dried to obtain the ethylene glycol bis(propionitrile) ether derivative.

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