Quantum dot diffusion plate and preparation method thereof

Abstract

The invention discloses a quantum dot diffusion plate and a preparation method thereof, and relates to the technical field of diffusion plate materials. In-mold composite four-layer co-extrusion is carried out on the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer to prepare the quantum dot diffusion plate, and the quantum dot layer added with the green quantum dots and the red quantum dots is used as a middle layer. Red quantum dots and green quantum dots of the quantum dot diffusion plate subjected to in-mold composite four-layer co-extrusion are located among different layers and do not interfere with each other, the red quantum dot layer and the green quantum dot layer are separated, the four-layer extrusion process is carried out, the prepared quantum dot diffusion plate is narrow in emission spectrum wave crest and high in quantum efficiency, meanwhile, the diffusion layer has low water molecule migration rate, and the quantum dot diffusion plate can be used for preparing the quantum dot diffusion plate. Therefore, the quantum dot diffusion plate has good water and oxygen barrier efficiency, and has a good water and oxygen barrier effect while having a diffusion plate function.

Description

Technical Field

[0001] The invention relates to the technical field of diffusion plate materials, in particular to a quantum dot diffusion plate and a preparation method thereof. Background Art

[0002] Quantum dots are a type of nanoscale semiconductor material. By applying a certain electric field or light pressure to this nano-semiconductor material, they will emit light of a specific frequency. The frequency of the emitted light will change with the size of the semiconductor. Therefore, by adjusting the size of the nano-semiconductor, the color of the light it emits can be controlled. Because this nano-semiconductor has the characteristic of confinement (electron to electron-hole transition), it is called a quantum dot.

[0003] Diffuser plates are commonly used in backlight modules. Their specific application is the direct-type backlight module using LED light sources. They mainly use the principle of multi-angle light refraction to diffuse the light emitted by the light source. Different from the beam-forming purpose of lighting, they can have more uniform luminous performance in the application of display panels. The quantum dot film is configured in the product, which can absorb a certain color light of a specific wavelength and convert it into other color light of another wavelength, greatly increasing the light margin performance of the backlight module. In the backlight module of the prior art, the diffuser plate is the closest to the lamp bead in terms of installation position, followed by the quantum dot film, the brightness enhancement film, and finally the display screen. The quantum dot film can be one or more until the expected light margin performance is achieved.

[0004] The invention patent with announcement number CN106918952A discloses a quantum dot diffusion plate, in which quantum dots are integrated during the extrusion molding process. The white light excitation layer is excited by blue light to produce white light that passes through the ineffective area of ​​the quantum dot diffusion plate, and the light emitted from the light output surface of the quantum dot diffusion plate is also white light. The color difference between the two is small, which can effectively solve the color difference problem in the visible area, and the color gamut uniformity of the backlight module is high. Summary of the invention

[0005] The object of the present invention is to provide a quantum dot diffusion plate with higher color gamut, higher brightness, high uniformity, health and environmental protection, and a preparation method thereof.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a quantum dot diffusion plate is produced by in-mold composite co-extrusion of four layers including a high-transmittance diffusion layer, a red quantum dot layer, a green quantum dot layer and a high-fog diffusion layer.

[0007] Preferably, the high-transmittance diffusion layer comprises the following components in mass percentage: 0.6-1.0% of a high-transmittance diffuser, 0.4-0.6% of an antioxidant, and the rest being polystyrene or polymethyl methacrylate; the high-mist diffusion layer comprises the following components in mass percentage: 0.5-0.7% of a high-mist diffuser, 0.4-0.6% of an antioxidant, and the rest being polystyrene or polymethyl methacrylate.

[0008] Preferably, the high-transmittance diffuser is an organic silicon light diffuser with a particle size of 2μ; the high-fog diffuser is an organic silicon light diffuser with a particle size of 1μ.

[0009] Preferably, the red quantum dot layer comprises the following components in mass percentage: 0.1-0.2% of red light perovskite quantum dots, and the rest is polystyrene or polymethyl methacrylate; the green quantum dot layer comprises the following components in mass percentage: 0.4-0.6% of green light perovskite quantum dots, and the rest is polystyrene or polymethyl methacrylate.

[0010] Preferably, the particle size of the red light perovskite quantum dots is 7 to 8 nm; and the particle size of the green light perovskite quantum dots is 2 to 3 nm.

[0011] Preferably, the thickness ratio of the high-transmittance diffuser, the red quantum dot layer, the green quantum dot layer and the high-fog diffuser is 1:(2.8-3.2):(2.8-3.2):1.

[0012] Preferably, a method for preparing a quantum dot diffusion plate comprises the following specific steps: the components of a high-transmittance diffusion layer, a red quantum dot layer, a green quantum dot layer and a high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form a high-transmittance diffusion layer, a red quantum dot layer, a green quantum dot layer and a high-fog diffusion layer respectively; and then the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are in-mold composited and co-extruded into four layers to obtain a quantum dot diffusion plate.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0014] The present invention performs in-mold composite four-layer co-extrusion on a high-transmittance diffusion layer, a red quantum dot layer, a green quantum dot layer and a high-fog diffusion layer to obtain a quantum dot diffusion plate. In the traditional three-layer co-extrusion process, red and green quantum dots are mixed and added into an intermediate layer, but there is interference between quantum dots with different particle sizes, resulting in low quantum efficiency. In the in-mold composite four-layer co-extrusion process of the present invention, a material layer with green and red quantum dots added is used as an intermediate layer, and two quantum dot materials with different proportions are added and blended and extruded. After the in-mold composite four-layer co-extrusion, the red and green quantum dots of the quantum dot diffusion plate are in different layers and do not interfere with each other. The red quantum dot layer and the green quantum dot layer are separated, and the in-mold composite four-layer co-extrusion process is performed. The obtained quantum dot diffusion plate has a narrow emission spectrum peak and high quantum efficiency.

[0015] The high-transmittance diffusion layer and the high-fog diffusion layer are diffusion layers, and silicone materials and antioxidants of different particle sizes are added. Different materials are extruded through in-mold composite co-extrusion technology, which has the function of diffusing quantum dots. At the same time, the diffusion layer has a lower water molecule mobility, so it can have a good water-oxygen barrier efficiency, so that the quantum dot diffusion plate has the function of a diffusion plate and has a good water-oxygen barrier effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of the quantum dot diffusion plate of the present invention. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0018] The preparation methods of green light perovskite quantum dots (CH3NH3PbBr3 quantum dots) and red light perovskite quantum dots (CH3NH3PbI3 quantum dots) used in the present invention are prepared by referring to the methods of Example 3 and Example 6 in application number CN 104861958 A.

[0019] In the embodiment of the present invention, the high-transmittance diffuser is a 3μ particle size organic silicon light diffuser from Changxing, and the high-fog diffuser is a 1μ particle size organic silicon light diffuser from Changxing; the antioxidant is antioxidant 1076; the polystyrene is Formosa Chemical 550; and the polymethyl methacrylate is Mitsubishi VH6001.

[0020] Example 1

[0021] The mass percentages of the components in each layer in this embodiment are:

[0022] High-transmittance diffusion layer thickness 0.4 mm: 0.6% high-transmittance diffuser, 0.4% antioxidant 1076, and the rest is polystyrene;

[0023] The thickness of the red quantum dot layer is 0.6 mm: 0.1% of the red light perovskite quantum dots with a particle size of 7 nm, and the rest is polystyrene;

[0024] Green quantum dot layer thickness 0.6mm: 0.4% 2nm green light perovskite quantum dots, the rest is polystyrene;

[0025] The thickness of the high fog diffusion layer is 0.4 mm: 0.5% of high fog diffuser, 0.4-0.6% of antioxidant, and the rest is polystyrene.

[0026] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0027] The components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then subjected to in-mold composite four-layer co-extrusion to obtain a quantum dot diffusion plate.

[0028] Example 2

[0029] The mass percentages of the components in each layer in this embodiment are:

[0030] High-transmittance diffusion layer thickness 0.4 mm: 0.8% high-transmittance diffuser, 0.5% antioxidant 1076, and the rest is polystyrene;

[0031] The thickness of the red quantum dot layer is 0.6 mm: 0.15% of the red light perovskite quantum dots with a particle size of 7 nm, and the rest is polystyrene;

[0032] Green quantum dot layer thickness 0.6mm: 0.5% of green light perovskite quantum dots with a particle size of 2nm, and the rest is polystyrene;

[0033] The thickness of the high fog diffusion layer is 0.4 mm: 0.6% of high fog diffuser, 0.5% of antioxidant, and the rest is polystyrene.

[0034] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0035] The components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then subjected to in-mold composite four-layer co-extrusion to obtain a quantum dot diffusion plate.

[0036] Example 3

[0037] The mass percentages of the components in each layer in this embodiment are:

[0038] High-transmittance diffusion layer thickness 0.4 mm: 1.0% high-transmittance diffuser, 0.6% antioxidant 1076, and the rest is polystyrene;

[0039] The thickness of the red quantum dot layer is 0.6 mm: 0.2% of the red light perovskite quantum dots with a particle size of 7 nm, and the rest is polystyrene;

[0040] Green quantum dot layer thickness 0.6mm: 0.6% of green light perovskite quantum dots with a particle size of 2nm, and the rest is polystyrene;

[0041] The thickness of the high fog diffusion layer is 0.4 mm: 0.7% of high fog diffuser, 0.6% of antioxidant, and the rest is polystyrene.

[0042] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0043] The components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then subjected to in-mold composite four-layer co-extrusion to obtain a quantum dot diffusion plate.

[0044] Example 4

[0045] The mass percentages of the components in each layer in this embodiment are:

[0046] High-transmittance diffusion layer thickness 0.4 mm: 0.8% high-transmittance diffuser, 0.5% antioxidant 1076, and the rest is polymethyl methacrylate;

[0047] The thickness of the red quantum dot layer is 0.6 mm: 0.15% of the red light perovskite quantum dots with a particle size of 7 nm, and the rest is polymethyl methacrylate;

[0048] Green quantum dot layer thickness 0.6mm: 0.5% of green light perovskite quantum dots with a particle size of 2nm, and the rest is polymethyl methacrylate;

[0049] High fog diffusion layer thickness 0.4mm: 0.6% high fog diffuser, 0.5% antioxidant, and the rest is polymethyl methacrylate;

[0050] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0051] The components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then subjected to in-mold composite four-layer co-extrusion to obtain a quantum dot diffusion plate.

[0052] Example 5

[0053] The mass percentages of the components in each layer in this embodiment are:

[0054] High-transmittance diffusion layer thickness 0.3 mm: 0.8% high-transmittance diffuser, 0.5% antioxidant 1076, and the rest is polystyrene;

[0055] The thickness of the red quantum dot layer is 0.45 mm: 0.15% of the red light perovskite quantum dots with a particle size of 7 nm, and the rest is polystyrene;

[0056] Green quantum dot layer thickness 0.45mm: 0.5% of green light perovskite quantum dots with a particle size of 2nm, and the rest is polystyrene;

[0057] High fog diffusion layer thickness 0.3mm: 0.6% high fog diffuser, 0.5% antioxidant, the rest is polystyrene;

[0058] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0059] The components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then subjected to in-mold composite four-layer co-extrusion to obtain a quantum dot diffusion plate.

[0060] Comparative Example 6

[0061] The mass percentages of the components in each layer in this embodiment are:

[0062] High-transmittance diffusion layer thickness 0.4 mm: 0.8% high-transmittance diffuser, 0.5% antioxidant 1076, and the rest is polystyrene;

[0063] The thickness of the red quantum dot layer is 0.6 mm: 0.15% of the red light perovskite quantum dots with a particle size of 8 nm, and the rest is polystyrene;

[0064] Green quantum dot layer thickness 0.6mm: 0.5% green light perovskite quantum dots with a particle size of 3nm, and the rest is polystyrene;

[0065] The thickness of the high fog diffusion layer is 0.4 mm: 0.6% of high fog diffuser, 0.5% of antioxidant, and the rest is polystyrene.

[0066] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0067] The components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are mixed and extruded according to mass percentage to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then subjected to in-mold composite four-layer co-extrusion to obtain a quantum dot diffusion plate.

[0068] Comparative Example

[0069] The mass percentages of the components in each layer in this embodiment are:

[0070] High-transmittance diffusion layer thickness 0.3 mm: 0.8% high-transmittance diffuser, 0.5% antioxidant 1076, and the rest is polystyrene;

[0071] The thickness of the quantum dot layer is 0.4 mm: 0.15% of the red light perovskite quantum dots with a particle size of 7 nm, 0.5% of the green light perovskite quantum dots with a particle size of 2 nm, and the rest is polystyrene;

[0072] High fog diffusion layer thickness 0.3mm: 0.6% high fog diffuser, 0.5% antioxidant, the rest is polystyrene;

[0073] The preparation method of the quantum dot diffusion plate in this embodiment is:

[0074] The components of the high-transmittance diffusion layer, the quantum dot layer and the high-fog diffusion layer are mixed in proportion to mass percentage and extruded to form the high-transmittance diffusion layer, the quantum dot layer and the high-fog diffusion layer respectively; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are then co-extruded to obtain a quantum dot diffusion plate.

[0075] Effect example

[0076] Table 1 below shows the performance analysis results of the quantum dot diffusion plates prepared using Examples 1 to 5 of the present invention and the comparative example:

[0077] Table 1

[0078] DCI-P3 color gamut DCI-P3 color gamut Example 1 103.67％ Example 5 105.13％ Example 2 105.04％ Example 6 104.50％ Example 3 104.82％ Comparative Example 98.20％ Example 4 104.35％

[0079] By comparing the experimental data of the embodiment and the comparative example in Table 1, it can be clearly found that the quantum dot diffusion plate prepared in the embodiment of the present invention has a higher DCI-P3 color gamut;

[0080] like Figure 1As shown, A is a high-transmittance diffusion, B is a red quantum dot layer, C is a green quantum dot layer, and D is a high-fog diffuser; the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are subjected to in-mold composite four-layer co-extrusion to obtain the quantum dot diffusion plate of the present invention, and the quantum dot layer with green quantum dots and red quantum dots is added as the middle layer. The red and green quantum dots of the in-mold composite four-layer co-extruded quantum dot layer are in different layers, and the red quantum dot layer and the green quantum dot layer are separated without interfering with each other. The four-layer extrusion process is performed, and the emission spectrum peak of the obtained quantum dot diffusion plate is narrow, so that the quantum efficiency is higher. The high-transmittance diffusion layer and the high-fog diffusion layer are diffusion layers, and organic silicon materials and antioxidants with different particle sizes are added. Different materials are extruded and formed by in-mold composite co-extrusion technology, and have the function of diffusion quantum dot composite. At the same time, because the two layers of the diffusion layer have a lower water molecule mobility, they can play a good water-oxygen barrier efficiency, so that the quantum dot diffusion plate has the function of a diffusion plate and a good water-oxygen barrier effect.

[0081] 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 quantum dot diffuser plate, characterized in that: The quantum dot diffusion plate is made by in-mold composite four-layer co-extrusion of high-transmittance diffusion, red quantum dot layer, green quantum dot layer and high-fog diffusion layer.

2. A quantum dot diffuser plate according to claim 1, characterized in that: The high-transmittance diffusion layer comprises the following components in mass percentage: 0.6-1.0% of a high-transmittance diffuser, 0.4-0.6% of an antioxidant, and the rest being polystyrene or polymethyl methacrylate; the high-mist diffusion layer comprises the following components in mass percentage: 0.5-0.7% of a high-mist diffuser, 0.4-0.6% of an antioxidant, and the rest being polystyrene or polymethyl methacrylate.

3. A quantum dot diffuser plate according to claim 2, characterized in that: The high-transmittance diffuser is an organic silicon light diffuser with a particle size of 2μ; the high-fog diffuser is an organic silicon light diffuser with a particle size of 1μ.

4. The quantum dot diffuser plate according to claim 1, characterized in that: The red quantum dot layer includes the following components in mass percentage: 0.1-0.2% of red light perovskite quantum dots, and the rest is polystyrene or polymethyl methacrylate; the green quantum dot layer includes the following components in mass percentage: 0.4-0.6% of green light perovskite quantum dots, and the rest is polystyrene or polymethyl methacrylate.

5. A quantum dot diffuser plate according to claim 4, characterized in that: The particle size of the red light perovskite quantum dots is 7-8 nm; the particle size of the green light perovskite quantum dots is 2-3 nm.

6. The quantum dot diffuser plate according to claim 1, characterized in that: The thickness ratio of the high-transmittance diffuser, the red quantum dot layer, the green quantum dot layer and the high-fog diffuser is 1:(2.8~3.2):(2.8~3.2):

1.

7. A method for preparing a quantum dot diffusion plate, characterized in that: The preparation method of the quantum dot diffusion plate comprises the following specific steps: the components of the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are proportioned according to mass percentage, fully mixed and extruded to form the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer respectively; and the high-transmittance diffusion layer, the red quantum dot layer, the green quantum dot layer and the high-fog diffusion layer are co-extruded in a mold to form a quantum dot diffusion plate.

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