A radiation-cured quantum dot powder coating, its preparation method, and its application.

Abstract

This invention provides a radiation-cured quantum dot powder coating, its preparation method, and its applications. The composite perovskite quantum dot material composition includes perovskite quantum dots / polymers coated with metal oxides, radiation-cured oligomers, photoinitiators, light-scattering particles, and additives. It is used in light-emitting diodes, light-converting devices, display devices, photovoltaic devices, lighting devices, ultraviolet detectors, sensors, hybrid composites, and biomarkers. The radiation-cured quantum dot powder composition of this invention does not contain solvents or reactive diluents, has low film curing shrinkage, is non-irritating, has low VOC emissions, and is environmentally friendly and healthy.

Description

Technical Field

[0001] This invention relates to a radiation-cured quantum dot powder coating, its preparation method, and its application, belonging to the field of quantum dot preparation. Background Technology

[0002] Perovskite quantum dots, as a novel semiconductor light-emitting material, possess optical properties comparable to traditional quantum dots. Furthermore, the fabrication process for perovskite quantum dots is very simple, allowing for their preparation at room temperature or low temperatures. The most significant advantage of perovskite quantum dots is their ability to enhance the color gamut to over 100% NTSC. However, the long-term stability of perovskite quantum dots in practical applications is problematic; the intrusion of water and oxygen in the environment leads to fluorescence quenching. Therefore, improving the stability of perovskite quantum dot materials is urgently needed.

[0003] Existing patents mostly use UV-curable liquid adhesives as encapsulation barrier materials for quantum dots. For example, Chinese invention patent CN201910752610.X uses a combination of quantum dots, photopolymerizable hyperbranched molecules, monomers, photoinitiators, and solvents to prepare an ink composition for quantum dot color filters. This ink is mainly used to prepare display devices with color conversion filters. Chinese patent ZL201711434422.X proposes mixing perovskite quantum dot precursors with acrylic monomers, and then adding acrylic oligomers to obtain a sol. This sol, after adding a UV curing agent, can be directly used for coating and UV curing into a thin film or directly molded into a material of the desired shape. Chinese patent ZL201710865772.5 synthesizes an organosilicon-modified hyperbranched oligomer, with radiation-curable groups and high heat-resistant functional groups attached to the molecular ends, used as the main material of a quantum dot sealant composition. It effectively reduces water and oxygen permeability, has higher bonding strength, good compatibility with quantum dot materials, has little impact on quantum dot luminescence efficiency, excellent weather resistance, and excellent water and oxygen barrier properties, providing very effective protection for quantum dot materials.

[0004] However, UV-curable liquid adhesives, due to their high viscosity, generally contain reactive diluents, which are irritating and detrimental to health. Furthermore, the synthesis of reactive diluents uses solvents such as cyclohexane or toluene, resulting in high VOC emissions that are harmful to the environment. Simultaneously, because reactive diluents have low molecular weights, the van der Waals forces between molecules transform into covalent bonds during curing, reducing the intermolecular distance and causing curing shrinkage, which can lead to poor adhesion and surface wrinkling. Radiation powder coatings, on the other hand, do not use reactive diluents, have low curing shrinkage, and are environmentally friendly and healthy. Chinese Patent 201910913006.0 proposes a UV-curable powder photoresist composition that combines UV resin, initiator, colorant, and additives to produce colored photoresist. Compared to the traditional color filter layer manufacturing process, it reduces energy consumption costs and is environmentally friendly. In addition, this UV-curable powder photoresist composition does not contain reactive diluents, resulting in low coating curing shrinkage, which can improve the problem of high gaps between the colored photoresist and the ribs formed by traditional spraying. However, it only proposes a process solution and does not combine it with quantum dot materials. Summary of the Invention

[0005] According to one aspect of this application, a radiation powder coating is provided.

[0006] A radiation powder coating comprising perovskite quantum dots / polymers, radiation-cured oligomers, and photoinitiators.

[0007] Optionally, the amounts of each component, by weight, are as follows:

[0008]

[0009] Optionally, the radiation powder coating may also contain light-scattering particles and additives.

[0010] Optionally, the amount of light-scattering particles added, by weight, is >0 and ≤50.

[0011] Optionally, the amount of the additive added, by weight, is >0 and ≤10.

[0012] Optionally, the perovskite quantum dot / polymer is produced by atomizing a perovskite quantum dot precursor solution into small droplets, and then drying the atomized droplets to generate perovskite quantum dot / polymer powder; the perovskite quantum dot precursor solution includes a solvent, perovskite quantum dot raw materials, and a polymer matrix.

[0013] Optionally, the perovskite quantum dot / polymer powder has a particle size of 0.1–50 μm.

[0014] Optionally, the solvent is selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide, trimethyl phosphate, triethyl phosphate, N-methylpyrrolidone, and dimethylacetamide.

[0015] Optionally, the perovskite quantum dot raw materials include AX, QX, and MXT.

[0016] Where A is NH2CHNH2 + (FA), CH3NH3 + (MA), Cs + At least one of them;

[0017] M is Pb 2+ Cd 2+ Mn 2+ Zn 2 +、Sn 2+ 、Ge 2+ Bi 3+ At least one of them;

[0018] Q is an aromatic group or an alkyl organic amine cation with not less than 3 carbon atoms;

[0019] X is at least one of the halide anions;

[0020] t = 2 or 3.

[0021] Optionally, the polymer matrix is ​​selected from at least one of polyvinylidene fluoride, polyvinylidene fluoride and trifluoroethylene copolymer, polyacrylonitrile, polyvinyl acetate, cellulose acetate, cyanocellulose, polysulfone, aromatic polyamide, polyimide, polycarbonate, polystyrene, and polymethyl methacrylate.

[0022] Optionally, the mass ratio of polymer matrix to solvent is 1:2 to 200.

[0023] Optionally, the mass ratio of polymer matrix to solvent is 1:5 to 50.

[0024] Optionally, the mass ratio of perovskite quantum dot raw material to polymer matrix is ​​1:1 to 500.

[0025] Optionally, the mass ratio of perovskite quantum dot raw material to polymer matrix is ​​1:5 to 100.

[0026] Optionally, the perovskite quantum dot precursor solution may further include additives and / or surface ligands.

[0027] Optionally, the additive is selected from at least one of zinc bromide, zinc iodide, stannous bromide, stannous iodide, cadmium bromide, cadmium iodide, and hypophosphorous acid.

[0028] Optionally, the mass ratio of the additive to the perovskite quantum dot raw material is 1:1 to 500.

[0029] Optionally, the mass ratio of the additive to the perovskite quantum dot raw material is 1:4 to 100.

[0030] Optionally, the surface ligand contains at least one of an organic acid, an organic acid halide, a long-chain organic amine, and a long-chain organic amine halide; the organic acid includes a saturated alkyl acid or an unsaturated alkyl acid with at least 3 carbon atoms; the long-chain organic amine is an alkyl amine or an aromatic amine with 4-24 carbon atoms; and the organic acid or long-chain organic amine halide is the halide corresponding to the organic acid or long-chain organic amine.

[0031] Optionally, the mass ratio of the surface ligand to the perovskite quantum dot raw material is 1:1 to 50.

[0032] Optionally, the mass ratio of the surface ligand to the perovskite quantum dot raw material is 1:2 to 20.

[0033] Optionally, the metal oxide-coated perovskite quantum dots / polymers are characterized by forming a metal oxide film by alternating adsorption of a metal source and water vapor pulses onto the surface of the quantum dots / polymers using atomic deposition technology. The metal source is selected from at least one of aluminum, silicon, titanium, and zirconium sources.

[0034] Optionally, the aluminum source is selected from at least one of trimethylaluminum, triethylaluminum, and aluminum trichloride.

[0035] Optionally, the silicon source is selected from at least one of methyl orthosilicate or ethyl orthosilicate.

[0036] Optionally, the titanium source is selected from at least one of tetrabutyl titanate, isopropyl titanate, and tetraethyl titanate.

[0037] Optionally, the zirconium source is selected from at least one of dimethylaminozirconium, tetrabutyl zirconate, n-butoxide, zirconium tert-butoxide, and zirconium isopropoxide.

[0038] Optionally, the feed flow rate of the perovskite quantum dot precursor solution is 1 mL / min to 5000 mL / min; the inlet air temperature is 40 to 200 °C.

[0039] Optionally, the atomized droplets are dried to become perovskite quantum dot / polymer powder and solvent vapor, which are then separated and the solvent is recovered.

[0040] Optionally, during the preparation process, purging with circulating gas is also required.

[0041] Optionally, an inactive gas can be used as the circulating gas.

[0042] Optionally, the inactive gas is selected from at least one of nitrogen and helium.

[0043] The inventors of this application have discovered that perovskite quantum dot polymer powder coated with a metal oxide coating can effectively block the influence of external light, electricity, and heat on the quantum dots through an inorganic layer, thereby solving the quenching phenomenon during UV powder coating.

[0044] Optionally, the radiation-cured oligomer includes both amorphous and crystalline oligomers.

[0045] Optionally, the oligomer includes at least one of epoxy oligomers, polyurethane acrylates, polyester oligomers, hyperbranched polyacrylates, and polyvinyl ether resins.

[0046] Optionally, the ratio of the amorphous oligomer to the crystalline oligomer, by mass, is (1-2):4.

[0047] The glass transition temperature (Tg) of the amorphous oligomer is between 45-55°C; it may be selected from at least one of the following resin grades: Uvecoat 2000, Uvecoat 2100, Uvecoat 2200, Uvecoat 2300, Uvecoat 3000, Uvecoat 3002, Uvecoat 3003, and Uvecoat 3005 from Decyanate Corporation; or at least one of the following resin grades: Uracross P3125, Uracross ZW4892P, and ZW4901P from DSM Corporation.

[0048] The glass transition temperature (Tg) of the semi-crystalline oligomer is between 80-90°C; optionally, the semi-crystalline oligomer is selected from at least one of Cytec's Uvecoat 9010 resin, DSM's Uracross P3307, and Uracross P3898 resin.

[0049] Optionally, the photoinitiator is selected from 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, ethyl 4-dimethylaminobenzoate, benzophenone, isopropylthioxanthone (a mixture of 2,4 isomers), ethyl 4-(N,N-dimethylamino)benzoate, isooctyl 4-(N,N-dimethylamino)benzoate, 2,4-dimethylaminobenzoate, etc. At least one of the following: 6-trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0050] Optionally, it is selected from at least one of bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, and ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

[0051] Optionally, the radiation powder coating also contains light scattering particles and additives;

[0052] The light-scattering particles are selected from inorganic light diffusing agents and / or organic light diffusing agents.

[0053] Optionally, the inorganic light diffusing agent is selected from at least one of barium sulfate, nano zinc oxide, and nano silica.

[0054] Optionally, the organic light diffusing agent is selected from at least one of PMMA microspheres, silicone microspheres, polytetrafluoroethylene wax, polypropylene wax, polyethylene wax microspheres, polyamide wax microspheres, and amide-modified polyethylene wax.

[0055] The additives are leveling agents and / or antioxidants.

[0056] Optionally, the leveling agent is selected from at least one of polyacrylate leveling agents, cellulose acetate butyrate leveling agents, and polyvinyl butyral leveling agents.

[0057] Optionally, the antioxidant is selected from at least one of 4-hydroxydodecanoic acid oxyaniline, N,N'-hexamethylene bis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide, 4,4-di-tert-octyl diphenylamine, 2,6-di-tert-butyl-p-cresol (BHT), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), tris[2,4-di-tert-butylphenyl] phosphite (antioxidant 168), pentaerythritol diphosphite bis(2,4-di-tert-butylphenol) (antioxidant 626), and pentaerythritol diphosphite bisoctadecyl ester (antioxidant 618).

[0058] The inventors of this application have discovered that the radiation powder obtained using the above formula does not use reactive diluents (such as solvents such as cyclohexane or toluene), resulting in low curing shrinkage, low VOC emissions, non-irritating properties, and environmental friendliness.

[0059] A second aspect of this application provides a method for fabricating a backlight assembly.

[0060] A method for fabricating a backlight component, the method comprising the following steps:

[0061] (1) Obtaining radiation-cured powder coatings;

[0062] (2) A substrate with powder is obtained by spraying radiation-cured powder coating onto the pixel vacancy of the substrate.

[0063] (3) The substrate with powder is heated under an infrared light source to melt and level the powder on the substrate, thus obtaining a substrate with flat powder.

[0064] (4) The substrate with flat powder is cured by ultraviolet light to obtain the backlight assembly.

[0065] Optionally, the spraying is electrostatic spraying, and the thickness of the spray is 20-110 μm.

[0066] Optionally, the infrared light source is a mid-wave infrared light source, the heating and melting temperature is 80-150℃, and the heating time is 1-3 minutes.

[0067] Optionally, the photocuring is performed using ultraviolet light curing with a dominant wavelength of 365 nm and a curing energy of 1000-9000 mJ / cm². 2 .

[0068] Optionally, in step (1), the method for preparing the radiation powder coating particles adopts the following steps:

[0069] After adding the components in proportion, mixing, granulating, and crushing, the radiation powder coating particles are obtained.

[0070] The granulation method employs twin-screw melt extrusion granulation.

[0071] The crushing method uses a medium crusher.

[0072] Optionally, the temperature of the twin-screw melt extrusion is 40℃-65℃, the screw speed is 100-500rpm, and the extrusion pressure is 50-60bar.

[0073] Optionally, the rotational speed of the intermediate crusher is 1000-2500 rpm.

[0074] Optionally, the material needs to be sieved after crushing, and the sieve mesh size is 50-1000 mesh.

[0075] A third aspect of this application provides the application of the above-mentioned radiation powder coating and the backlight assembly obtained by the above-mentioned preparation method in semiconductor light-emitting materials.

[0076] The applications include light-emitting diodes, light-converting devices, display devices, photovoltaic devices, lighting devices, ultraviolet detectors, sensors, hybrid composites, biomarkers, and backlight modules.

[0077] Optionally, the display device includes a liquid crystal display or an imaging sensor.

[0078] Optionally, the photovoltaic device includes a solar cell.

[0079] Optionally, the sensor includes a biosensor.

[0080] Optionally, the light-emitting diode includes an electroluminescent diode or an organic light-emitting diode.

[0081] The beneficial effects that this application can produce include:

[0082] 1) The radiation powder coating provided in this application does not contain reactive diluents, can produce very low VOC emissions, has low curing shrinkage, is non-irritating, and is environmentally friendly and healthy.

[0083] 2) The backlight assembly preparation method provided in this application uses perovskite quantum dots / polymer particles with a metal oxide protective layer, which can block the influence of external light, electricity and heat on the quantum dots, thereby solving the quenching phenomenon during the powder coating process;

[0084] 3) The light-emitting diodes, light-converting devices, display devices, photovoltaic devices, lighting devices, ultraviolet detectors, sensors, hybrid complexes, biomarkers, and backlight modules provided in this application are characterized by low toxicity and no easily volatile components. Attached Figure Description

[0085] Figure 1 This describes the preparation method of the radiation-cured composite perovskite quantum dot composition in Example 1 of this application;

[0086] Figure 2 The following are samples prepared for the quantum dot composite material in Example 1 of this application: Figure a shows a radiation quantum dot strip obtained by a twin-screw extruder extrusion process; Figure b shows radiation-cured quantum dot particles obtained by granulation of the strip; and Figure c shows radiation-cured quantum dot powder obtained by pulverizing the particles.

[0087] Figure 3 This is a schematic diagram of the coating process in Embodiment 1 of this application;

[0088] Figure 4 A backlight sample was prepared for the green quantum dot composite material of Example 1 of this application;

[0089] Figure 5 The quantum dot composite material spectrum of Example 1 of this application;

[0090] Figure 6 These are red quantum dot composition particles prepared in Example 2 of this application;

[0091] Figure 7 The backlight sample prepared from the red quantum dot composition of Example 2 of this application;

[0092] Figure 8 The emission spectrum of the red quantum dot composition in Example 2 of this application;

[0093] Figure 9 In Example 1 of this application Figure 5 Schematic diagram of the apparatus for preparing perovskite quantum dots / polymers by spray drying.

[0094] List of components and reference numerals:

[0095] Figure 1 middle,

[0096] 1- High-speed disperser for pre-dispersion; 2- Twin-screw extruder; 3- Granulator;

[0097] 4-Medium crusher; 5-Collection tank;

[0098] Figure 3 middle,

[0099] 6-Mini-LED substrate with purple LED beads; 7-Electrostatic spray gun;

[0100] 8-Green quantum dot composition; 9-Mid-wave infrared irradiation equipment;

[0101] 10 - UV curing equipment; 11 - Glass cover plate;

[0102] Figure 9 middle,

[0103] 11-Precursor canister 12-Atomizer 13-Drying tower

[0104] 14-Cyclone separator 15-Powder outlet 16-Exhaust fan

[0105] 17-Solvent recovery port 18-Condensation tower 19-Hot air blower Detailed Implementation

[0106] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0107] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased commercially. MABr, PbBr2, CsBr, DMF, and PbI2 were purchased from Aladdin Reagents; Uvecoat 2000, Uvecoat 2100, Uvecoat 2200, Uvecoat 2300, Uvecoat 3000, Uvecoat 3002, Uvecoat 3003, Uvecoat 3005, and Uvecoat 9010 were from Cytec; Uracross P3125, Uracross ZW4892P, ZW4901P, Uracross P3307, and Uracross P3898 were from DSM; and 1-hydroxycyclohexylphenyl ketone and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide were from IGM.

[0108] The spray drying used in Example 1 of this application is a closed-loop nitrogen circulation spray dryer manufactured by Anyan Instruments, model AYAN-BL-5L.

[0109] The ALD coating used in Example 1 of this application is a cavity-type atomic deposition system, model G10, manufactured by Xiamen Yunmao Technology.

[0110] For the spray drying technology, the technology of patent application number 202011192457.9 is adopted. Specifically, the spray drying technology steps used in Example 1 are as follows:

[0111] The mass ratio of MABr to PbBr2 was 1:1.2. The mass ratio of (MABr+PbBr2) to dodecylamine was 3:1. The mass ratio of (MABr+PbBr2) to PVDF was 1:10. The mass ratio of PVDF to N,N-dimethylformamide was 1:10. All raw materials were mixed and mechanically stirred for 3 hours to ensure complete dissolution and obtain a precursor solution. This precursor solution was poured into a precursor container at a feed flow rate of 50 mL / min, an atomizer speed of 20,000 r / min, and an inlet air temperature of 80℃. The resulting perovskite quantum dot / polymer composite ultrafine powder emitted green fluorescence.

[0112] For the ALD coating technology, the technology of patent application number 202111217166.5 is adopted. Specifically, the steps of ALD coating of metal oxide layer used in Example 1 are as follows:

[0113] The perovskite quantum dot precursor solution is placed in a precursor tank (1), and atomized into small droplets by an atomizer (2) in a drying tower (3). Hot air generated by a hot air blower (9) is introduced into the drying tower to dry the atomized droplets, generating perovskite quantum dot / polymer composite ultrafine powder. The perovskite quantum dot / polymer composite ultrafine powder generated in the drying tower and solvent vapor enter a cyclone separator (4) for dry-wet separation. The perovskite quantum dot / polymer composite ultrafine powder is collected from the powder outlet (5) below the cyclone separator. The moisture in the cyclone separator enters a condenser tower (8) via an induced draft fan (6) to condense the solvent. The solvent is collected from the solvent recovery port (7), and the air is discharged.

[0114] Example 1

[0115] Preparation of green MAPbBr3 perovskite / polymer: 0.22 g of MABr, 0.8 g of PbBr2, and 0.18 g of octylamine bromide were dissolved in 200 ml of anhydrous N,N-dimethylformamide (DMF), and then 10 g of polymethyl methacrylate polymer (PMMA) was added to form a precursor solution. After stirring for 2 hours, standard spray drying was performed to obtain green perovskite / polymer powder.

[0116] ALD Coating: MAPbBr3 perovskite / polymer perovskite quantum dots / polymer green powder were placed in an ALD device and subjected to pulsed argon gas at 500 Pa and 80 °C to ensure full contact between the trimethylaluminum precursor and the quantum dots / polymer green powder. Water vapor was then introduced for 5 seconds to hydrolyze the trimethylaluminum adsorbed on the quantum dot surface into aluminum oxide. This process was repeated 100 times to obtain a 20 nm thick aluminum oxide-coated MAPbBr3 perovskite / polymer.

[0117] Example 2

[0118] Weigh out 20g of coated MAPbBr3 perovskite / polymer, 40g of polyester oligomer Uvecoat3000, 320g of polyester acrylate Uvecoat 9010, 7.2g of 1-hydroxycyclohexylphenyl ketone, 10.4g of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 15g of antioxidant 1010, 30g of nano-spherical organosilicon light scattering particles, and 5g of polyacrylate leveling agent. Add as follows: Figure 1 Pre-dispersion is carried out in a medium-high speed disperser 1. The sample is then transferred through a funnel to a twin-screw extruder 2, where the melt extrusion temperature is 100℃, the screw speed is 300 rpm, and the extrusion pressure is 50 bar. The extruded sample is granulated in a granulator 3, and the granules are then crushed in a medium crusher 4 and collected in a collection tank 5. Its emission spectrum is as follows: Figure 5 As shown, the emission peak is located at 527 nm, and the full width at half maximum (FWHM) is 23 nm.

[0119] Example 3

[0120] Composite coating applications: such as Figure 3 As shown, the quantum dot composition is sprayed onto the pixel holes of the Mini-LED substrate 1 with purple LED beads using an electrostatic gun 2. After being heat-treated at 80°C for 1 minute by an infrared irradiation device 4, it achieves leveling, and then passes through a UV mercury lamp 5 at 5000mJ / cm². 2 Solidification is achieved under energy irradiation, resulting in... Figure 4 The sample shown. After encapsulating the surface with a glass cover plate 6, a black-and-white display mini-LED backlight substrate is obtained.

[0121] Example 4

[0122] Preparation of red CsPbBrI2 perovskite quantum dots / polymer: 0.434 g of CsBr, 0.986 g of PbI2, and 0.18 g of octylamine bromide were dissolved in 200 ml of anhydrous N,N-dimethylformamide (DMF), and then 10 g of polymethyl methacrylate (PMMA) polymer precursor solution was added. After stirring for 2 hours, standard spray drying was performed to obtain red perovskite / polymer powder.

[0123] The ALD coating and composition preparation were performed in the same manner as in Example 1, except that MAPbBr3 perovskite / polymer was replaced with CsPbBrI2 in equal proportions to obtain CsPbBrI2 perovskite quantum dots / polymer coated with alumina.

[0124] Example 5

[0125] Weigh out 20g of coated CsPbBrI2 perovskite / polymer, 40g of polyester oligomer Uracross P3125, 100g of polyester acrylate Uvecoat 9010, 110g of vinyl ether amino resin Uracross P3307, 10.0g of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 5g of antioxidant 1010, 8g of antioxidant 626, 30g of nano-hydrophobic titanium dioxide light scattering particles, and 5g of polyacrylate leveling agent. Add as follows: Figure 1 Pre-dispersion was carried out in a high-speed disperser (1). The sample was then transferred through a funnel to a twin-screw extruder (2), where the melt extrusion temperature was 60℃, the screw speed was 300 rpm, and the extrusion pressure was 50 bar. The extruded sample was granulated in a granulator (3), and the granules were then crushed in a crusher (4) and collected in a collection tank (5). Its luminescence spectrum is as follows... Figure 8 As shown, the emission peak is located at 647 nm, and the full width at half maximum (FWHM) is 34 nm.

[0126] Example 6

[0127] Composition Coating Application: The quantum dot composition is sprayed onto the pixel holes of the Mini-LED substrate 1 with blue LED beads using an electrostatic gun 2. After heat treatment at 110°C for 1 minute using an infrared irradiation device 4, leveling is achieved. Then, it is passed through a UV mercury lamp 5 at 3000mJ / cm². 2 Solidification is achieved under energy irradiation, resulting in... Figure 7 The sample shown.

[0128] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A radiation powder coating, characterized in that, The radiation powder coating comprises perovskite quantum dots / polymers coated with metal oxides, radiation-cured oligomers, photoinitiators, light-scattering particles, and additives. The amounts of each component, by weight, are as follows: 4-20 parts of perovskite quantum dots / polymers coated with metal oxides 80-500 parts of radiation-cured oligomer 2-20 parts of photoinitiator 0-50 parts of light scattering particles 0-30 parts of auxiliary agent; The perovskite quantum dots / polymers coated with metal oxides are prepared by alternating adsorption of metal sources and water vapor pulses on the surface of quantum dots / polymers using atomic deposition technology, thereby forming a metal oxide thin film. The metal source is selected from at least one of aluminum source, titanium source and zirconium source; The perovskite quantum dots / polymer is produced by atomizing a perovskite quantum dot precursor solution into small droplets, and then drying the atomized droplets. The perovskite quantum dots / polymers have a particle size of 0.1~50 μm.

2. The radiation powder coating according to claim 1, characterized in that, The perovskite quantum dot precursor solution includes a solvent, perovskite quantum dot raw materials, and a polymer matrix.

3. The radiation powder coating according to claim 2, characterized in that, The solvent is selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide, trimethyl phosphate, triethyl phosphate, N-methylpyrrolidone, and dimethylacetamide.

4. The radiation powder coating according to claim 2, characterized in that, The perovskite quantum dot raw materials include AX, QX, and MXT; Where A is NH2CHNH2 + (FA), CH3NH3 + (MA), Cs + At least one of them; M is Pb 2+ Cd 2+ Mn 2+ Zn 2 +、Sn 2+ 、Ge 2+ Bi 3+ At least one of them; Q is an aromatic group or an alkyl organic amine cation with not less than 3 carbon atoms; X is at least one of the halide anions; t=2 or 3.

5. The radiation powder coating according to claim 2, characterized in that, The polymer matrix is ​​selected from at least one of polyvinylidene fluoride, polyvinylidene fluoride and trifluoroethylene copolymer, polyacrylonitrile, polyvinyl acetate, cellulose acetate, cyanocellulose, polysulfone, aromatic polyamide, polyimide, polycarbonate, polystyrene, and polymethyl methacrylate.

6. The radiation powder coating according to claim 2, characterized in that, The mass ratio of the polymer matrix to the solvent is 1:2~200.

7. The radiation powder coating according to claim 2, characterized in that, The mass ratio of the polymer matrix to the solvent is 1:5~50.

8. The radiation powder coating according to claim 2, characterized in that, The mass ratio of the perovskite quantum dot raw material to the polymer matrix is ​​1:1 to 500.

9. The radiation powder coating according to claim 2, characterized in that, The mass ratio of perovskite quantum dot raw material to polymer matrix is ​​1:5~100.

10. The radiation powder coating according to claim 2, characterized in that, The perovskite quantum dot precursor solution also includes additives and / or surface ligands.

11. The radiation powder coating according to claim 10, characterized in that, The additive is selected from at least one of zinc bromide, zinc iodide, stannous bromide, stannous iodide, cadmium bromide, cadmium iodide, and hypophosphorous acid.

12. The radiation powder coating according to claim 10, characterized in that, The mass ratio of the additive to the perovskite quantum dot raw material is 1:1 to 500.

13. The radiation powder coating according to claim 10, characterized in that, The mass ratio of the additive to the perovskite quantum dot raw material is 1:4~100.

14. The radiation powder coating according to claim 10, characterized in that, The surface ligand contains at least one of organic acid, organic acid halogen, long-chain organic amine, and long-chain organic amine halogen.

15. The radiation powder coating according to claim 14, characterized in that, The organic acids include saturated alkyl acids and / or unsaturated alkyl acids having at least 3 carbon atoms.

16. The radiation powder coating according to claim 14, characterized in that, The long-chain organic amine is an alkylamine and / or an aromatic amine with 4-24 carbon atoms.

17. The radiation powder coating according to claim 14, characterized in that, The halides of the organic acid or long-chain organic amine are the halides corresponding to the organic acid and / or long-chain organic amine.

18. The radiation powder coating according to claim 10, characterized in that, The mass ratio of the surface ligand to the perovskite quantum dot raw material is 1:1~50.

19. The radiation powder coating according to claim 10, characterized in that, The mass ratio of the surface ligand to the perovskite quantum dot raw material is 1:2~20.

20. The radiation powder coating according to claim 1, characterized in that, The aluminum source is selected from at least one of trimethylaluminum, triethylaluminum, and aluminum trichloride; The titanium source is selected from at least one of tetrabutyl titanate, isopropyl titanate, and tetraethyl titanate; The zirconium source is selected from at least one of dimethylaminozirconium, tetrabutyl zirconate, zirconium n-butoxide, zirconium tert-butoxide, and zirconium isopropoxide.

21. The radiation powder coating according to claim 1, characterized in that, The feed flow rate of the perovskite quantum dot precursor solution is 1 mL / min to 5000 mL / min; the inlet air temperature is 40 to 200 ℃.

22. The radiation powder coating according to claim 1, characterized in that, After drying, the atomized droplets become perovskite quantum dot / polymer powder and solvent vapor, which are then separated and the solvent is recovered.

23. The radiation powder coating according to claim 1, characterized in that, During the preparation process, it is also necessary to purge with circulating gas.

24. The radiation powder coating according to claim 23, characterized in that, Inactive gases are used as circulating gases.

25. The radiation powder coating according to claim 24, characterized in that, The inactive gas is selected from at least one of nitrogen and helium.

26. The radiation powder coating according to claim 1, characterized in that, The radiation-cured oligomers include both amorphous and crystalline oligomers.

27. The radiation powder coating according to claim 26, characterized in that, The ratio of the amorphous oligomer to the crystalline oligomer, by mass, is (1-2):

4.

28. The radiation powder coating according to claim 26, characterized in that, The glass transition temperature (Tg) of the amorphous oligomer is between 45 and 55 °C.

29. The radiation powder coating according to claim 26, characterized in that, The amorphous oligomer is selected from at least one of the following brands: Uvecoat2000, Uvecoat2100, Uvecoat2200, Uvecoat2300, Uvecoat3000, Uvecoat3002, Uvecoat3003, Uvecoat3005 from Cytec, and Uracross P3125, Uracross ZW4892P, and ZW4901P from DSM.

30. The radiation powder coating according to claim 1, characterized in that, The photoinitiator is selected from 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, ethyl 4-dimethylaminobenzoate, benzophenone, isopropylthioxanthone (a mixture of 2,4 isomers), ethyl 4-(N,N-dimethylamino)benzoate, isooctyl 4-(N,N-dimethylamino)benzoate, 2,4-dimethylaminobenzoate, etc. At least one of 6-trimethylbenzoyl-diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

31. The radiation powder coating according to claim 1, characterized in that, The photoinitiator is selected from at least one of bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, and ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

32. The radiation powder coating according to claim 1, characterized in that, The light-scattering particles are selected from inorganic light diffusing agents and / or organic light diffusing agents.

33. The radiation powder coating according to claim 32, characterized in that, The inorganic light diffusing agent is selected from at least one of barium sulfate, nano zinc oxide, nano silicon dioxide, and nano titanium dioxide.

34. The radiation powder coating according to claim 32, characterized in that, The organic light diffusing agent is selected from at least one of PMMA microspheres, organosilicon microspheres, polytetrafluoroethylene wax, polypropylene wax, polyethylene wax microspheres, polyamide wax microspheres, and amide-modified polyethylene wax.

35. The radiation powder coating according to claim 1, characterized in that, The additives are leveling agents and / or antioxidants.

36. The radiation powder coating according to claim 35, characterized in that, The leveling agent is selected from at least one of polyacrylate leveling agents, cellulose acetate butyrate leveling agents, and polyvinyl butyral leveling agents.

37. The radiation powder coating according to claim 35, characterized in that, The antioxidant is selected from at least one of 4-hydroxydodecanoic acid oxyaniline, N,N'-hexamethylene bis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide, 4,4-di-tert-octyl diphenylamine, 2,6-di-tert-butyl-p-cresol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris[2,4-di-tert-butylphenyl] phosphite, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, and pentaerythritol diphosphite dioctadecyl ester.

38. A method for preparing a radiation powder coating, characterized in that, The radiation powder coating comprises perovskite quantum dots / polymers coated with metal oxides, radiation-cured oligomers, photoinitiators, light-scattering particles, and additives. The amounts of each component, by weight, are as follows: 4-20 parts of perovskite quantum dots / polymers coated with metal oxides 80-500 parts of radiation-cured oligomer 2-20 parts of photoinitiator 0-50 parts of light scattering particles 0-30 parts of auxiliary agent; The preparation method includes the following steps: The perovskite quantum dot precursor solution is atomized into small droplets, and then the atomized droplets are dried to generate perovskite quantum dots / polymers. Metal sources and water vapor pulses are alternately adsorbed onto the surface of perovskite quantum dots / polymers using atomic deposition technology to form metal oxide films, thus obtaining perovskite quantum dots / polymers coated with metal oxides. The metal source is selected from at least one of aluminum source, titanium source and zirconium source; The aluminum source is selected from at least one of trimethylaluminum, triethylaluminum, and aluminum trichloride; The titanium source is selected from at least one of tetrabutyl titanate, isopropyl titanate, and tetraethyl titanate; The zirconium source is selected from at least one of dimethylaminozirconium, tetrabutyl zirconate, zirconium n-butoxide, zirconium tert-butoxide, and zirconium isopropoxide. The perovskite quantum dots / polymers have a particle size of 0.1~50 μm.

39. A method for fabricating a backlight assembly, the method comprising the following steps: (1) Obtaining radiation-cured powder coatings; (2) A substrate with powder is obtained by spraying radiation-cured powder coating onto the pixel vacancy of the substrate. (3) The substrate with powder is heated under an infrared light source to melt and level the powder on the substrate, thus obtaining a substrate with flat powder. (4) The substrate with the flat powder is cured by ultraviolet light to obtain the backlight assembly; The radiation-cured powder coating comprises any one of the radiation powder coatings according to claims 1-37.

40. The preparation method according to claim 39, characterized in that, The coating is applied using electrostatic spraying, and the coating thickness is 20-110 μm.

41. The preparation method according to claim 39, characterized in that, The infrared light source is a mid-wave infrared light source, and the heating and melting temperature is 80-150 ℃, with a heating time of 1-3 min.

42. The preparation method according to claim 39, characterized in that, The photocuring process uses ultraviolet light with a dominant wavelength of 365 nm and a curing energy of 1000-9000 mJ / cm². 2 .

43. The method for manufacturing a backlight assembly according to claim 39, characterized in that, The radiation-cured powder coating in step (1) is obtained by the following method: The radiation-cured powder coating is obtained by mixing, granulating, and pulverizing the various components. The granulation method employs twin-screw melt extrusion granulation. The crushing method uses a medium crusher.

44. The preparation method according to claim 43, characterized in that, The temperature of the twin-screw melt extrusion is 40℃-65℃, the screw speed is 100-500rpm, and the extrusion pressure is 50-60bar.

45. The preparation method according to claim 43, characterized in that, The rotational speed of the intermediate crusher is 1000~2500 rpm.

46. ​​The preparation method according to claim 43, characterized in that, After crushing, it needs to be sieved, with a mesh size of 200-1000.

47. The application of the radiation powder coating according to any one of claims 1-37 or the backlight assembly obtained by the method according to any one of claims 39-46 in semiconductor light-emitting materials; Specifically used in light-emitting diodes, light-converting devices, display devices, photovoltaic devices, lighting devices, ultraviolet detectors, sensors, hybrid composites, biomarkers, and backlight modules; The display device includes a liquid crystal display or an imaging sensor; The photovoltaic device includes a solar cell; The sensors include biosensors; The light-emitting diode includes an electroluminescent diode or an organic light-emitting diode.

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