Quantum dot display module and preparation method and application thereof
By dispersing quantum dots into high-barrier organic polymer materials and preparing quantum dot composite optical films or optical diffusion plates through melt extrusion multi-layer coextrusion technology, the stability problems caused by oxidation during use of quantum dot optical materials are solved, and both low cost and high stability are achieved.
Patent Information
- Application Number
- CN202311275364.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-28
- Publication Date
- 2025-03-28
AI Technical Summary
During use, the existing quantum dot optical film and optical diffusion plate are oxidized by oxygen and water vapor due to contact with air, resulting in a decrease in fluorescence intensity, and is costly, complex in process, and it is difficult to take into account both stability and cost.
The quantum dot or quantum dot precursor material is dispersed into high-barrier organic polymer materials, and a high-stability quantum dot composite optical film or optical diffusion plate is prepared by melt extrusion and multi-layer coextrusion.
It realizes high stability and low cost of the quantum dot display module, simplifies the preparation process, improves the cost-effectiveness of the product, and is safe and environmentally friendly, suitable for mass production.
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Figure CN119730583A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of quantum dot backlight display, and relates to a quantum dot display module and a preparation method and application thereof, and in particular to a high-barrier quantum dot display module and a preparation method and application thereof. Background Art
[0002] As an emerging semiconductor material, quantum dots are nanoparticles with a size smaller than or close to the Bohr radius of the exciton in the bulk material and exhibiting quantum effects. Due to the special structure of quantum dots, they have quantum size effects, macroscopic quantum tunneling effects, dielectric confinement effects, and surface effects, resulting in unique physical and chemical properties and unique luminescence performance. Due to the existence of the size confinement effect, it has the advantages of narrow luminescence peak and adjustable wavelength. Therefore, compared with traditional fluorescent materials, quantum dot materials show great advantages and are a more excellent luminescent material. In recent years, quantum dot luminescent materials have been applied to the backlight source of liquid crystal display devices, which can significantly improve the color gamut of liquid crystal display devices and restore colors more realistically.
[0003] However, there is currently a problem of poor water and oxygen resistance in the use of quantum dots, that is, quantum dots are in contact with air during use and are easily oxidized by oxygen and water vapor in the air, causing a decrease in fluorescence intensity. To solve the above problem, quantum dot optical film products generally use magnetron sputtering or evaporation to introduce a dense inorganic layer (materials such as silicon nitride, silicon oxide or aluminum oxide) on the surface of the substrate to block water and oxygen and maintain the stability of the optical performance of the quantum dot optical film during use.
[0004] For example, the existing quantum dot optical film structure is generally a multi-layer structure, which may specifically include, from top to bottom, an upper diffusion layer, a PET layer, an inorganic barrier layer (aluminum oxide), a quantum dot layer (UV glue + red quantum dots + green quantum dots, UV glue accounts for 98-99.99%), an inorganic barrier layer (aluminum oxide), a PET layer, and a lower diffusion layer. However, the above structure (UV glue barrier diffusion composite film) has caused a substantial increase in costs, and the price of UV glue is relatively high. The price of UV glue with general performance is more than 100 yuan / kg, but UV glue does not have barrier properties, and the product has obvious failure edge problems. If a barrier layer is set, the general price of high-performance barrier film is 30 yuan / m 2 , which basically limits the large-scale use of quantum dot optical films. Moreover, the quantum dot optical films with the above structure are complex in structure and have low yield.
[0005] As another form of using quantum dots in backlight modules, quantum dot optical diffuser plates generally use core-shell coating technology to coat quantum dots in the middle layer through three-layer co-extrusion composite form, and use upper and lower layers of organic resin to coat the quantum dot material, or use multi-layer composite organic barrier resin encapsulation to form a 7-layer or 10-layer structure.
[0006] For example, the quantum dot optical diffuser plate includes an upper diffusion layer (PMMA or PS + diffusion particles), a quantum dot layer (PMMA or PS + quantum dots), and a lower diffusion layer (PMMA or PS + diffusion particles) stacked in sequence from top to bottom. The above structure does not use a water and oxygen barrier film, but makes some adjustments to the quantum dot structure, such as thickening the quantum dot shell layer, and inorganic wrapping of the quantum dots, so that the stability of the quantum dot optical diffuser plate is improved. Although the above structure does not use a barrier film to coat the quantum dots, the cost of the quantum dot optical diffuser plate of the above structure has not been significantly reduced due to the adjustment of the structure of the quantum dots themselves. In addition, the above structure has extremely high requirements for the stability of the quantum dots, and the matrix of the quantum dot layer does not have a barrier property, the stability is poor, and there is a failure edge, resulting in the stability of the optical diffuser plate has never met the requirements of mass production applications.
[0007] When the quantum dot optical diffuser plate is encapsulated with a multi-layer composite organic barrier resin to form a 10-layer structure, its specific structure can be, for example, an upper diffusion protection layer, a bonding layer, a barrier layer, a bonding layer, a red quantum dot layer, a green quantum dot layer, a bonding layer, a barrier layer, a bonding layer, and a lower diffusion protection layer, which is similar to the existing quantum dot optical film. The quantum dot optical diffuser plate with this structure has a higher cost.
[0008] Therefore, in the art, it is desired to develop a quantum dot display module which not only has high stability but also has low cost and simple process. Summary of the invention
[0009] In view of the problems of poor packaging stability and high cost of existing quantum dot composite film / plate structures such as perovskite, cadmium selenide, and indium phosphide, the purpose of the present invention is to provide a quantum dot display module and its preparation method and application. The present invention disperses quantum dots or quantum dot precursor materials into high-barrier organic polymer materials, and prepares high-stability quantum dot composite optical films by melt extrusion and multi-layer co-extrusion. It can also make high-stability and cost-effective quantum dot optical diffusion plates by melt extrusion plate preparation technology and multi-layer composite co-extrusion technology. The quantum dot display module provided by the present invention has high stability, low cost, simple preparation process, high efficiency, and is easy to mass-produce.
[0010] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:
[0011] In a first aspect, the present invention provides a quantum dot display module, the quantum dot display module comprising a blocking light conversion layer, a first bonding layer and a second bonding layer are respectively arranged on both sides of the blocking light conversion layer, a first protective layer is arranged on a side of the first bonding layer away from the blocking light conversion layer, and a second protective layer is arranged on a side of the second bonding layer away from the blocking light conversion layer;
[0012] The barrier light conversion layer includes quantum dots and high barrier organic polymer materials.
[0013] The present invention uses a barrier light-conversion layer containing quantum dots and high-barrier organic polymer materials as a core layer. The provided quantum dot display module has the advantages of high luminous efficiency, high stability, good compatibility with polymer matrix, high membrane transmittance, etc., and solves the stability problem of the quantum dot optical diffusion plate, and solves the problems of high price of UV glue of quantum dot composite optical film, failure edge, high price of barrier film, complex process and low yield.
[0014] Preferably, the high barrier organic polymer material includes any one of ethylene-vinyl alcohol copolymer (EVOH), thermoplastic polyvinyl alcohol (Excevalv), polyacrylonitrile (PAN) or polyamide (MXD6) or a combination of at least two of them. Ethylene-vinyl alcohol copolymer has good thermoplasticity, and is used as a barrier material with good processing performance and excellent weather resistance; MXD6 is a special type of nylon material. General nylon (PA) materials have poor weather resistance and transparency, and are very hygroscopic and cannot be used as barrier materials. MXD6 has relatively low hygroscopicity.
[0015] Preferably, the thermoplastic polyvinyl alcohol EXCEVAL includes QA-4104, which can be melt-extruded and has very good water and oxygen barrier properties. Conventional PVA does not have thermoplastic processability because the melting point and decomposition point of PVA are relatively close. The general processing method is to use water to dissolve at high temperature and high pressure or add a certain amount of polyol as a plasticizer to produce and process polyvinyl alcohol. Such methods are incompatible with the extrusion composite process, and the addition of water and polyol will destroy the stability of quantum dots. The thermoplastic polyvinyl alcohol used in the present invention is the Kuraray EXCEVAL series, which has good thermoplastic processability.
[0016] Preferably, the quantum dots include red quantum dots and green quantum dots.
[0017] Preferably, the quantum dots include any one of cadmium selenide quantum dots, indium phosphide quantum dots or perovskite quantum dots (which may be perovskite quantum dot glass powder, sprayed organic-coated powder, chemically coated perovskite quantum dots) or a combination of at least two thereof.
[0018] Preferably, based on the total mass of the blocking and light-converting layer as 100%, the content of the quantum dots is 0.01%-2%, for example, it can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc., and the content of the high-barrier organic polymer material is 98%-99.99%, for example, 98%, 98.3%, 98.5%, 98.8%, 99%, 99.3%, 99.5%, 99.8%, 99.9%, 99.99%, etc.
[0019] Preferably, the thickness of the blocking and light-converting layer is 150-250 μm, for example, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, etc.
[0020] Preferably, the raw materials for preparing the first adhesive layer and the second adhesive layer include modified resin.
[0021] Preferably, the raw materials for preparing the first adhesive layer and the second adhesive layer include graft-modified high molecular polymers.
[0022] Preferably, the raw materials for preparing the first adhesive layer and the second adhesive layer independently include any one or a combination of at least two of maleic anhydride modified polypropylene, maleic anhydride modified polyethylene, maleic anhydride modified ethylene-vinyl acetate copolymer, methacrylic acid modified polypropylene, methacrylic acid modified polyethylene or methacrylic acid modified ethylene-vinyl acetate copolymer.
[0023] Preferably, the raw materials for preparing the first adhesive layer and the second adhesive layer further include any one of an antioxidant, a heat stabilizer or a UV absorber, or a combination of at least two of them.
[0024] Preferably, the thickness of the first adhesive layer and the second adhesive layer are independently 80-120 μm, for example, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, etc.
[0025] In the present invention, the material of the first protective layer and the second protective layer is an optically transparent weather-resistant resin. Preferably, the raw materials for preparing the first protective layer and the second protective layer independently include any one or a combination of at least two of polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polyethylene terephthalate (PET), cyclohexanedimethanol-modified copolyester (PETG) or polypropylene (PP).
[0026] Preferably, the raw materials for preparing the first protective layer and the second protective layer also include any one or a combination of at least two of an antioxidant, a heat stabilizer, a UV absorber or a diffusant. According to the different application requirements of each product, the above functional auxiliary materials can be added to the first protective layer and the second protective layer, such as adding diffusing particles, to provide a uniform light effect.
[0027] Preferably, the thickness of the first protective layer and the second protective layer is independently 300-500 μm, for example, 300 μm, 330 μm, 350 μm, 380 μm, 400 μm, 430 μm, 450 μm, 480 μm, 500 μm, etc.
[0028] Preferably, the surfaces of the first protective layer and the second protective layer are provided with a pattern structure. According to different application requirements of each product, patterns can be prepared on the surfaces of the first protective layer and the second protective layer (by embossing the film (plate)).
[0029] Preferably, the blocking light conversion layer is two layers, one of which is distributed with red quantum dots, and the other is distributed with green quantum dots. That is, the quantum dot display module includes a first protective layer, a first bonding layer, a first blocking light conversion layer, a second blocking light conversion layer, a second bonding layer, and a second protective layer stacked in sequence, wherein the first blocking light conversion layer includes red (or green) quantum dots and a high-barrier organic polymer material, and the second blocking light conversion layer includes green (or red) quantum dots and a high-barrier organic polymer material.
[0030] Preferably, the quantum dot display module is a quantum dot composite optical film or a quantum dot optical diffusion plate.
[0031] In a second aspect, the present invention provides a method for preparing the quantum dot display module as described in the first aspect, the preparation method comprising the following steps:
[0032] The quantum dots or quantum dot precursor materials and high-barrier organic polymer materials, the raw materials for preparing the first bonding layer and the second bonding layer, and the raw materials for preparing the first protective layer and the second protective layer are melted respectively, and a quantum dot composite optical film is obtained by casting or blow molding, or a quantum dot optical diffusion plate is obtained by multi-layer co-extrusion, that is, the quantum dot display module is obtained.
[0033] Preferably, the quantum dot precursor material includes a red quantum dot precursor material and / or a green quantum dot precursor material.
[0034] As a preferred technical solution of the present invention, the preparation method comprises the following steps:
[0035] (1) mixing quantum dots and high-barrier organic polymer materials, and then adding them into the first screw feeding bin;
[0036] (2) adding the raw materials for preparing the first bonding layer and the second bonding layer into the first screw drying silo and the second screw drying silo respectively;
[0037] (3) Adding the raw materials for preparing the first protective layer and the second protective layer into the third screw drying silo and the fourth screw drying silo respectively;
[0038] (4) obtaining a quantum dot composite optical film by melt extrusion multi-layer composite casting and blow molding, or obtaining a quantum dot optical diffuser plate by melt extrusion multi-layer composite casting and multi-layer composite co-extrusion, that is, obtaining the quantum dot display module;
[0039] Alternatively, the preparation method comprises the following steps:
[0040] (a) mixing a first quantum dot precursor material and a high barrier organic polymer material, and then adding them to a first screw feeding bin, and mixing a second quantum dot precursor material and a high barrier organic polymer material, and then adding them to a second screw feeding bin;
[0041] (b) adding the raw materials for preparing the first bonding layer and the second bonding layer into the first screw drying silo and the second screw drying silo respectively;
[0042] (c) adding the raw materials for preparing the first protective layer and the second protective layer into the third screw drying silo and the fourth screw drying silo respectively;
[0043] (d) obtaining a quantum dot composite optical film by melt extrusion multi-layer composite casting and blow molding, or obtaining a quantum dot optical diffuser plate by melt extrusion multi-layer composite casting and multi-layer composite co-extrusion, that is, obtaining the quantum dot display module.
[0044] The preparation process of the present invention is simple, which is conducive to improving product yield and reducing costs; by improving the barrier resin performance, the stability of the quantum dot composite film can be greatly improved; and it is safe, environmentally friendly, and conducive to mass production. The second preparation method provided by the present invention combines the quantum dot in-situ preparation method, uses quantum dot precursor materials, disperses the quantum dot precursor materials into the high barrier organic polymer material of the barrier light conversion layer of the composite material, generates quantum dot materials in the high temperature melting preparation process, and prepares the composite film (plate) material by blow molding or multi-layer composite co-extrusion.
[0045] Preferably, the mixing in step (1) and step (a) includes pre-dispersion granulation, physical mixing of materials, etc.
[0046] Preferably, in step (a), the first quantum dot precursor material is a red quantum dot precursor material, and the second quantum dot precursor material is a green quantum dot precursor material; or, the first quantum dot precursor material is a green quantum dot precursor material, and the second quantum dot precursor material is a red quantum dot precursor material.
[0047] In a third aspect, the present invention provides an application of the quantum dot display module as described in the first aspect in a display.
[0048] Compared with the prior art, the present invention has the following beneficial effects:
[0049] The present invention embeds quantum dots into high-barrier organic polymer materials by melt extrusion. The provided quantum dot display module has the advantages of high luminous efficiency, high stability, good compatibility with polymer matrix, high membrane transmittance, etc., which well solves the stability problem of quantum dot optical diffusion plate, and solves the problems of high price of UV glue of quantum dot composite optical film, failure edge, high price of barrier film, complex process and low yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0050] Figure 1 A schematic diagram of the structure of the quantum dot display module provided in Example 1;
[0051] Among them, 1 is a light-blocking and light-conversion layer, 2 is a first bonding layer, 3 is a second bonding layer, 4 is a first protective layer, 5 is a second protective layer, 6 is red quantum dots, 7 is green quantum dots, and 8 is diffusion particles.
[0052] Figure 2 This is a spectrum diagram of the quantum dot display module provided in Example 1.
[0053] Figure 3 This is a diagram showing the reliability test results of the quantum dot display module provided in Example 1.
[0054] Figure 4 This is a spectrum diagram of the quantum dot display module provided in Example 2.
[0055] Figure 5 A schematic diagram of the structure of a quantum dot display module provided in Example 4;
[0056] Among them, 11-first blocking and light-converting layer, 12-second blocking and light-converting layer, 2-first bonding layer, 3-second bonding layer, 4-first protective layer, 5-second protective layer, 6-red quantum dots, 7-green quantum dots, and 8-diffusing particles.
[0057] Figure 6 This is a diagram showing the reliability test results of the quantum dot display module provided in Example 4.
[0058] Figure 7This is a diagram showing the reliability test results of the quantum dot display module provided in Comparative Example 1. DETAILED DESCRIPTION
[0059] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.
[0060] The raw material information used in the examples and comparative examples of the present invention is as follows:
[0061] Green quantum dot precursor materials: cesium stearate: lead stearate: octylamine bromide: octylamine iodide: N,N-dimethyl-N-(3-sulfopropyl)-1-octadecyl ammonium inner salt = 1:1:5:0.5:0.5 (molar ratio);
[0062] Red quantum dot precursor materials: cesium stearate: lead stearate: octylamine bromide: octylamine iodide: N,N-dimethyl-N-(3-sulfopropyl)-1-octadecyl ammonium inner salt = 1:1:3:3.5:0.5 (molar ratio);
[0063] EVOH: Changchun Chemical, brand EV3251;
[0064] Thermoplastic polyvinyl alcohol: Kuraray, EXCEVAL brand -AQ4104;
[0065] Polyamide resin: Japan Mitsubishi, MXD6 Reny series 1511;
[0066] Maleic anhydride grafted modified resin: SK General Chemical, brand name OREVAC-18910;
[0067] PMMA: Chimei, brand CM205M;
[0068] PS: Chimei, brand number is PG383;
[0069] Diffusion particles: from Huizhou fluorescent new materials;
[0070] Antioxidant: BASF, Antioxidant 1010.
[0071] Example 1
[0072] In this embodiment, a quantum dot display module (specifically a quantum dot optical diffuser) is provided, and its structural schematic diagram is shown as follows: Figure 1 As shown, the quantum dot display module includes a blocking light conversion layer 1, a first bonding layer 2 and a second bonding layer 3 are respectively arranged on both sides of the blocking light conversion layer 1, a first protective layer 4 is arranged on the side of the first bonding layer 2 away from the blocking light conversion layer 1, and a second protective layer 5 is arranged on the side of the second bonding layer 3 away from the blocking light conversion layer 1;
[0073] The blocking light-conversion layer 1 includes red cadmium selenide quantum dots 6 and green cadmium selenide quantum dots 7 and a high-barrier organic polymer material (EVOH), and the first protective layer 4 and the second protective layer 5 are dispersed with diffusion particles 8 .
[0074] The thickness of the blocking and light-converting layer is 200 μm, the thickness of the first adhesive layer and the second adhesive layer are both 100 μm, and the thickness of the first protective layer and the second protective layer are both 400 μm.
[0075] The preparation method comprises the following steps:
[0076] (1) mixing red and green cadmium selenide quantum dots and EVOH resin uniformly, and then adding them into the first screw feeding bin; wherein the total content of red and green cadmium selenide quantum dots is 0.06% (the mass ratio of the two quantum dots is 1:1), and the content of EVOH resin is 99.94%;
[0077] (2) adding the raw materials for preparing the first bonding layer and the second bonding layer (both maleic anhydride grafted modified resin and antioxidant, with a mass ratio of 99.8:0.2) into the first screw drying silo and the second screw drying silo respectively;
[0078] (3) Adding the raw materials for preparing the first protective layer and the second protective layer (PMMA, diffusion particles and antioxidant in a mass ratio of 94.8:5:0.2) into the third screw drying silo and the fourth screw drying silo respectively;
[0079] (4) A quantum dot optical diffusion plate is obtained by melt extrusion of multi-layer composite casting and multi-layer composite co-extrusion, that is, the quantum dot display module is obtained; wherein the extrusion temperature of the blocking light conversion layer is 215°C, the extrusion temperature of the first adhesive layer and the second adhesive layer are both 220°C, and the extrusion temperature of the first protective layer and the second protective layer are both 235°C.
[0080] The spectrum of the quantum dot display module provided in this embodiment is as follows: Figure 2 As shown, it can be seen that the green light wavelength of the quantum dot display module is 537nm, and the half-peak width is 27nm; the red light wavelength is 626nm, and the half-peak width is 26nm.
[0081] The reliability test results of the quantum dot display module provided in this embodiment are shown in the figure below: Figure 3 As shown, it can be seen that the quantum dot display module has strong reliability.
[0082] The cost of the quantum dot display module provided in this embodiment is 41.4 yuan / m 2 , lower cost.
[0083] Example 2
[0084] In this embodiment, a quantum dot display module (specifically, a quantum dot optical film) is provided, wherein the quantum dot display module comprises a blocking light conversion layer, a first bonding layer and a second bonding layer are respectively provided on both sides of the blocking light conversion layer, a first protective layer is provided on a side of the first bonding layer away from the blocking light conversion layer, and a second protective layer is provided on a side of the second bonding layer away from the blocking light conversion layer;
[0085] The blocking light conversion layer includes red and green perovskite quantum dots and a high-barrier organic polymer material (thermoplastic polyvinyl alcohol Excevalv).
[0086] The thickness of the light-blocking and light-converting layer is 80 μm, the thickness of the first adhesive layer and the second adhesive layer are both 20 μm, and the thickness of the first protective layer and the second protective layer are both 50 μm.
[0087] The preparation method comprises the following steps:
[0088] (1) Mixing red and green perovskite quantum dots and Excevalv resin uniformly, and then adding them into the first screw feeding bin; wherein the total content of red and green perovskite quantum dots is 0.1% (the mass ratio of the two quantum dots is 1:1), and the content of Excevalv resin is 99.9%;
[0089] (2) adding the raw materials for preparing the first bonding layer and the second bonding layer (both maleic anhydride grafted modified resin and antioxidant, with a mass ratio of 99.8:0.2) into the first screw drying silo and the second screw drying silo respectively;
[0090] (3) Adding the raw materials for preparing the first protective layer and the second protective layer (PS, diffusion particles and antioxidant in a mass ratio of 94.8:5:0.2) into the third screw drying silo and the fourth screw drying silo respectively;
[0091] (4) A quantum dot composite optical film is obtained by melt extrusion of a multi-layer composite casting and blow molding, that is, the quantum dot display module is obtained; wherein the extrusion temperature of the barrier light conversion layer is 215°C, the extrusion temperature of the first adhesive layer and the second adhesive layer are both 225°C, and the extrusion temperature of the first protective layer and the second protective layer are both 235°C.
[0092] The spectrum of the quantum dot display module provided in this embodiment is as follows: Figure 4 As shown, it can be seen that the green light wavelength of the quantum dot display module is 542nm, and the half-peak width is 24nm; the red light wavelength is 624nm, and the half-peak width is 37nm.
[0093] The cost of the quantum dot display module provided in this embodiment is 26.8 yuan / m 2 , lower cost.
[0094] Example 3
[0095] In this embodiment, a quantum dot display module (specifically, a quantum dot optical film) is provided, wherein the quantum dot display module comprises a blocking light conversion layer, a first bonding layer and a second bonding layer are respectively provided on both sides of the blocking light conversion layer, a first protective layer is provided on a side of the first bonding layer away from the blocking light conversion layer, and a second protective layer is provided on a side of the second bonding layer away from the blocking light conversion layer;
[0096] The blocking light-conversion layer includes red and green perovskite quantum dots and a high-barrier organic polymer material (polyamide resin MXD6).
[0097] The thickness of the light-blocking and light-converting layer is 80 μm, the thickness of the first adhesive layer and the second adhesive layer are both 20 μm, and the thickness of the first protective layer and the second protective layer are both 50 μm.
[0098] The preparation method comprises the following steps:
[0099] (1) mixing red and green perovskite quantum dots with MXD6 uniformly, and then adding them into the first screw feeding bin; wherein the total content of red and green perovskite quantum dots is 0.1% (the mass ratio of the two quantum dots is 1:1), and the content of MXD6 is 99.9%;
[0100] (2) adding the raw materials for preparing the first bonding layer and the second bonding layer (both maleic anhydride grafted modified resins) into the first screw drying silo and the second screw drying silo respectively;
[0101] (3) Adding the raw materials for preparing the first protective layer and the second protective layer (both PS) into the third screw drying silo and the fourth screw drying silo respectively;
[0102] (4) A quantum dot composite optical film is obtained by melt extrusion, multi-layer composite casting and blow molding; that is, the quantum dot display module is obtained; wherein the extrusion temperature of the barrier light conversion layer is 250°C, the extrusion temperature of the first adhesive layer and the second adhesive layer are both 230°C, and the extrusion temperature of the first protective layer and the second protective layer are both 240°C.
[0103] The cost of the quantum dot display module provided in this embodiment is 24 yuan / m 2 , lower cost.
[0104] Example 4
[0105] In this embodiment, a quantum dot display module (specifically a quantum dot optical film) is provided, and its structural schematic diagram is shown as follows: Figure 5As shown, the quantum dot display module includes a first protective layer 4, a first bonding layer 2, a first blocking light conversion layer 11, a second blocking light conversion layer 12, a second bonding layer 3, and a second protective layer 5 which are stacked in sequence, wherein the first blocking light conversion layer 11 includes red quantum dots 6 and a high-barrier organic polymer material (EVOH), the second blocking light conversion layer 12 includes green quantum dots 7 and a high-barrier organic polymer material (EVOH), and the first protective layer 4 and the second protective layer 5 are dispersed with diffusion particles 8.
[0106] The thickness of the first light-blocking and light-conversion layer and the second light-blocking and light-conversion layer are both 80 μm, the thickness of the first adhesive layer and the second adhesive layer are both 50 μm, and the thickness of the first protective layer and the second protective layer are both 70 μm.
[0107] The preparation method comprises the following steps:
[0108] (1) Mix the red quantum dot precursor material and EVOH resin in a mass ratio of 99.97:0.03 evenly, and then add them into the first screw feeding bin; mix the green quantum dot precursor material and EVOH resin in a mass ratio of 99.97:0.03 evenly, and then add them into the second screw feeding bin;
[0109] (2) adding the raw materials for preparing the first bonding layer and the second bonding layer (both maleic anhydride grafted modified resin and antioxidant, with a mass ratio of 99.8:0.2) into the first screw drying silo and the second screw drying silo respectively;
[0110] (3) Adding the raw materials for preparing the first protective layer and the second protective layer (PMMA, diffusion particles and antioxidant in a mass ratio of 94.8:5:0.2) into the third screw drying silo and the fourth screw drying silo respectively;
[0111] (4) A quantum dot optical diffusion plate is obtained by melt extrusion of multi-layer composite casting and multi-layer composite co-extrusion, that is, the quantum dot display module is obtained; wherein the extrusion temperatures of the first barrier light conversion layer and the second barrier light conversion layer are both 210°C, the extrusion temperatures of the first bonding layer and the second bonding layer are both 220°C, and the extrusion temperatures of the first protective layer and the second protective layer are both 230°C.
[0112] The reliability test results of the quantum dot display module provided in this embodiment are shown in the figure below: Figure 6 As shown, it can be seen that the quantum dot display module has strong reliability.
[0113] The cost of the quantum dot display module provided in this embodiment is 28 yuan / m 2 , lower cost.
[0114] Comparative Example 1
[0115] The only difference between this comparative example and Example 1 is that the high barrier organic polymer material (EVOH) is replaced by an equal amount of PMMA.
[0116] The reliability test results of the quantum dot display module provided in this comparative example are shown in the figure below: Figure 7 As shown, it can be seen that compared with Example 1, the reliability of the quantum dot display module provided in Comparative Example 1 is significantly reduced.
[0117] Comparative Example 2
[0118] In this comparative example, a quantum dot optical film is provided, which includes, from top to bottom, an upper diffusion layer (50 μm thick), a PET layer (20 μm thick), an inorganic barrier layer (aluminum oxide, 10 nm thick), a quantum dot layer (UV glue + red perovskite quantum dots + green perovskite quantum dots, UV glue accounts for 99%, and the mass ratio of red perovskite quantum dots to green perovskite quantum dots is 1:1), an inorganic barrier layer (aluminum oxide, 10 nm thick), a PET layer (20 μm thick), and a lower diffusion layer (50 μm thick) which are stacked in sequence.
[0119] The raw materials for preparing the upper diffusion layer and the lower diffusion layer include PS, diffusion particles and antioxidants in a mass ratio of 94.8:5:0.2; the UV glue is Esdico quantum dot film UV glue.
[0120] The preparation method can refer to the conventional method in the prior art.
[0121] The quantum dot display modules provided in the embodiments and comparative examples were tested for performance, and the testing method was as follows:
[0122] (1) Brightness decay rate under blue light radiation conditions: After the quantum dot display module is subjected to blue light accelerated aging radiation with a radiation intensity of 3000 nits for 1500 hours, the brightness decay rate of the quantum dot display module is recorded;
[0123] (2) Brightness decay rate under dry heat storage conditions: After the quantum dot display module is subjected to dry heat accelerated aging in an oven at 85°C for 1500 h, the brightness decay rate of the quantum dot display module is recorded;
[0124] (3) Brightness decay rate under humid heat blue light accelerated aging radiation conditions: After the quantum dot display module was irradiated with blue light with a radiation intensity of 5000 nits for 1500 hours at 65°C and 95% RH, the brightness decay rate of the quantum dot display module was recorded.
[0125] The performance test results are shown in Table 1.
[0126] Table 1
[0127]
[0128] It can be seen from Table 1 that the quantum dot display modules provided by Examples 1-4 of the present invention have a low brightness decay rate under blue light, dry heat storage and wet heat blue light test conditions, high stability and strong reliability.
[0129] Compared with Example 1, the quantum dot display module provided in Comparative Example 1 has an increased brightness attenuation rate and decreased stability under the blue light, dry heat storage and wet heat blue light test conditions.
[0130] Compared with Example 4, the stability of the quantum dot optical film provided in Comparative Example 2 is not significantly different and is at the same level; however, the structure and process of the scheme in Comparative Example 2 are relatively complex, and the cost is 50 yuan / m 2 , the cost is higher.
[0131] The applicant declares that the present invention illustrates the quantum dot display module and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
Claims
1. A quantum dot display module, characterized in that: The quantum dot display module comprises a blocking light conversion layer, a first bonding layer and a second bonding layer are respectively arranged on both sides of the blocking light conversion layer, a first protective layer is arranged on a side of the first bonding layer away from the blocking light conversion layer, and a second protective layer is arranged on a side of the second bonding layer away from the blocking light conversion layer; The barrier light conversion layer includes quantum dots and high barrier organic polymer materials.
2. The quantum dot display module according to claim 1, characterized in that: The high barrier organic polymer material includes any one of ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyamide or thermoplastic polyvinyl alcohol, or a combination of at least two thereof; Preferably, the quantum dots include red quantum dots and green quantum dots; Preferably, the quantum dots include any one of cadmium selenide quantum dots, indium phosphide quantum dots or perovskite quantum dots, or a combination of at least two of them.
3. The quantum dot display module according to claim 1 or 2, characterized in that: Taking the total mass of the barrier light conversion layer as 100%, the content of the quantum dots is 0.01%-2%, and the content of the high barrier organic polymer material is 98%-99.99%.
4. The quantum dot display module according to any one of claims 1 to 3, characterized in that: The raw materials for preparing the first bonding layer and the second bonding layer include modified resin; Preferably, the raw materials for preparing the first adhesive layer and the second adhesive layer include graft-modified high molecular polymers; Preferably, the raw materials for preparing the first adhesive layer and the second adhesive layer independently include any one or a combination of at least two of maleic anhydride modified polypropylene, maleic anhydride modified polyethylene, maleic anhydride modified ethylene-vinyl acetate copolymer, methacrylic acid modified polypropylene, methacrylic acid modified polyethylene or methacrylic acid modified ethylene-vinyl acetate copolymer.
5. The quantum dot display module according to any one of claims 1 to 4, characterized in that: The raw materials for preparing the first adhesive layer and the second adhesive layer further include any one of an antioxidant, a heat stabilizer or a UV absorber, or a combination of at least two of them.
6. The quantum dot display module according to any one of claims 1 to 5, characterized in that: The raw materials for preparing the first protective layer and the second protective layer independently include any one or a combination of at least two of polymethyl methacrylate, polycarbonate, polystyrene, polyethylene terephthalate, cyclohexanedimethanol-modified copolyester or polypropylene; Preferably, the raw materials for preparing the first protective layer and the second protective layer further include any one or a combination of at least two of an antioxidant, a heat stabilizer, a UV absorber or a diffusant; Preferably, the surfaces of the first protective layer and the second protective layer are provided with pattern structures.
7. The quantum dot display module according to any one of claims 1 to 6, characterized in that: The blocking and light conversion layer consists of two layers, one of which is distributed with red quantum dots, and the other is distributed with green quantum dots; Preferably, the quantum dot display module is a quantum dot composite optical film or a quantum dot optical diffusion plate.
8. A method for preparing a quantum dot display module according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The quantum dots or quantum dot precursor materials and high-barrier organic polymer materials, the raw materials for preparing the first bonding layer and the second bonding layer, and the raw materials for preparing the first protective layer and the second protective layer are melted respectively, and a quantum dot composite optical film is obtained by casting or blow molding, or a quantum dot optical diffusion plate is obtained by multi-layer co-extrusion, that is, the quantum dot display module is obtained.
9. The preparation method according to claim 8, characterized in that: The quantum dot precursor material includes a red quantum dot precursor material and / or a green quantum dot precursor material.
10. Use of the quantum dot display module according to any one of claims 1 to 7 in a display.