A method for preparing a quantum dot functional printed light guide plate

Abstract

The present invention discloses a method for preparing a quantum dot functional printed light guide plate, and relates to the technical field of light guide plates. The present invention discloses a method for preparing a quantum dot functional printed light guide plate, comprising the following steps: using a silk screen printing process to print quantum dot ink on the opposite side of the light emitting surface of a substrate plate, drying and curing to obtain a quantum dot functional layer; adding a reflective film on the quantum dot functional layer, and adding an optical film layer on the light emitting surface of the substrate plate to obtain a quantum dot functional printed light guide plate; the present application realizes high-efficiency white light emission under blue light excitation by silk screen printing quantum dot ink on a transparent material light guide plate, and has the advantages of high color reproduction, high light efficiency, simple preparation process, etc., and is suitable for use in high-end display devices and lighting systems.

Description

Technical Field

[0001] The present invention relates to the technical field of light guide plates, and in particular to a method for preparing a quantum dot functional printed light guide plate. Background Art

[0002] Liquid crystal displays have developed rapidly in the display field with the advantages of low power consumption and soft images, and have gradually become the most widely used display devices. However, liquid crystal displays cannot emit light by themselves and need to rely on external backlight modules, which are the main components of liquid crystal displays. The light guide plate determines the uniformity and color gamut of the backlight module. Traditional white light LEDs are made by covering a layer of yellow phosphor coating (main component YAG) on gallium nitride blue light LEDs (wavelength 450-470nm), but its emission spectrum lacks effective red components, and the emitted cold white light has limited color expression and light efficiency. As an alternative to phosphor materials, quantum dots (QDs) are a novel semiconductor nanomaterial composed of group II-VII or group III-V elements. The diameter of a single quantum dot particle is only about 2-10nm, and it has many unique nano properties. The luminescence peak of quantum dots is narrow, ensuring the high purity of light; the luminescence color of quantum dots is adjustable, which can achieve a wider color gamut, and has higher luminescence efficiency and longer service life; quantum dots increase the display color gamut of the device. Quantum dot materials are widely studied for improving the performance of display and lighting equipment due to their high color purity, adjustable emission wavelength and excellent stability.

[0003] Quantum dot materials have excellent linear optical properties, narrow emission peaks and wide absorption peaks. Their electrons and holes are quantum confined, and the continuous energy band structure becomes a discrete energy level structure, which can emit fluorescence after being excited. Structurally, quantum dots are composed of core, shell and surface ligands. Without protective measures, quantum dots will face two aspects of damage: one is from the polymer colloids around the quantum dots; if the chemical compatibility of quantum dots and colloids is poor, the quantum dots themselves will agglomerate, and the agglomeration will increase the probability of fluorescence resonance energy transfer in quantum dots, resulting in an increase in non-radiative transitions and a decrease in efficiency; on the other hand, it comes from small molecules of water and oxygen in the environment. Water and oxygen erosion will cause defects on the surface and inside of quantum dots. These defects lead to an increase in non-radiative transitions, resulting in a decrease in the luminescence efficiency of quantum dots; the above two types of damage will cause the luminescence of quantum dots to gradually weaken and quench during use. In the prior art, in order to ensure the luminescence stability of quantum dots, the following two methods are usually used for improvement: (1) surface chemical modification of quantum dots to improve the chemical compatibility of quantum dots and polymer colloids; for example, using 4-thiomethylstyrene as a surface ligand or using a cross-linking agent to cross-link quantum dots and polymer materials, etc. However, in the process of surface modification of quantum dots and ligand exchange, more surface defects will inevitably be generated on the surface of quantum dots, thereby reducing the luminescence efficiency of the quantum dots themselves; and surface modification cannot solve the problem of quantum dots being corroded by water and oxygen; (2) wrapping the surface of quantum dots with a nanometer-thick silicon oxide protective layer. The dense silicon oxide protective layer makes it difficult for water and oxygen molecules in the environment to penetrate. However, the surface coating process is a chemical reaction process, which still inevitably replaces the ligands on the surface of quantum dots and blocks the luminescence of quantum dots, resulting in a reduction in the quantum efficiency of quantum dots. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a quantum dot functional printed light guide plate to solve the following technical problems:

[0005] Existing quantum dots have poor compatibility with colloidal chemistry and are easily corroded by water and oxygen in the environment, which causes the luminescence of the quantum dots to gradually weaken and quench during use, affecting the use effect of the light guide plate.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a quantum dot functional printed light guide plate comprises the following steps:

[0008] S1: Printing quantum dot ink on the opposite side of the light emitting surface of the substrate plate by silk screen printing, drying and UV curing to make the quantum dot functional layer firmly attached to the light guide plate substrate plate, thereby obtaining the quantum dot functional layer;

[0009] S2: adding a reflective film on the quantum dot functional layer and adding an optical film layer on the light emitting surface of the substrate plate to obtain a quantum dot functional printed light guide plate;

[0010] The preparation method of quantum dot ink comprises the following steps:

[0011] A1: mixing a green quantum dot material and a solvent to obtain a green quantum dot material solution;

[0012] A2: Mixing red quantum dot material and solvent to obtain a red quantum dot material solution;

[0013] A3: Mix the green quantum dot material solution, the red quantum dot material solution and the UV glue to obtain quantum dot ink;

[0014] The green quantum dot material is obtained by loading green quantum dots on modified mesoporous silica; the red quantum dot material is obtained by loading red quantum dot material on modified mesoporous silica;

[0015] The preparation method of the modified mesoporous silica comprises the following steps:

[0016] B1: Add phenylated mesoporous silica, chloroform, N,N-dimethylacetamide, chlorotrimellitic anhydride and tin tetrachloride into reactor A and disperse evenly, react at room temperature for 3-6 hours, filter under reduced pressure, wash with water and dry to obtain component 1;

[0017] B2: In a nitrogen atmosphere, add bis(trichloromethyl) carbonate and carbon tetrachloride component 1 to reactor B and disperse them evenly, control the temperature at 0-5°C, mix component 1 and ethanol and add them to reactor B and disperse them evenly, mix triethylamine and carbon tetrachloride component 2 and add them to reactor B and disperse them evenly, control the temperature at 50-60°C, keep the reaction warm for 9-15h, filter, wash with ethanol, and dry to obtain component 2;

[0018] B3: Add components two, 2-hydroxyethyl disulfide (CSA: 1892-29-1), triethylamine and tetrahydrofuran into reactor C and disperse them evenly. Control the temperature at 0-5°C, keep the reaction warm for 1-3 hours, adjust the pH to 8-9, add dithiothreitol (CSA: 34834-12-3) in a nitrogen atmosphere, control the temperature at 30-40°C, keep the reaction warm for 1-3 hours, rotary evaporate, wash with ether and dry to obtain modified mesoporous silica.

[0019] As a further solution of the present invention: the mass ratio of red quantum dot material: green quantum dot material in quantum dot ink is 1:9-13; the green quantum dot material and the red quantum dot material together account for 20-40% of the total mass of the quantum dot ink; the volume ratio of solvent: UV glue in the quantum dot ink is 2:1.

[0020] As a further embodiment of the present invention: the solvent is any one of n-hexane, chlorobenzene and chloroform.

[0021] As a further solution of the present invention: The specific steps of loading green quantum dots on modified mesoporous silica are:

[0022] Add 0.2-0.5 green quantum dots, 1 g modified mesoporous silica, and 3-10 mL n-hexane into reactor D, control the temperature to 60-70° C., adjust the pH to 5-6, keep warm and stir to evaporate the solvent, and dry to obtain green quantum dot material.

[0023] As a further solution of the present invention: The specific steps of loading red quantum dots on modified mesoporous silica are:

[0024] 0.2-0.5 red quantum dots, 1 g modified mesoporous silica, and 3-10 mL n-hexane were added into reactor E, the temperature was controlled at 60-70° C., the pH was adjusted to 5-6, and the mixture was stirred to evaporate the solvent and dried to obtain red quantum dot material.

[0025] As a further solution of the present invention: the addition ratio of phenylated mesoporous silica, chloroform, N,N-dimethylacetamide, chlorotrimellitic anhydride, and tin tetrachloride in B1 is 1 g: 20-40 mL: 10-20 mL: 1-3 g: 1.5-2.5 mL.

[0026] As a further embodiment of the present invention: the carbon tetrachloride component 1 and the carbon tetrachloride component 2 in B2 are both carbon tetrachloride; the addition ratio of bis(trichloromethyl) carbonate, carbon tetrachloride component 1, component 1, ethanol, triethylamine, and carbon tetrachloride component 2 is 15-30 g: 150-200 mL: 10 g: 20-30 mL: 3-5 g: 20-40 mL.

[0027] As a further embodiment of the present invention: the addition ratio of component 2, 2-hydroxyethyl disulfide, triethylamine, tetrahydrofuran and dithiothreitol in B3 is 10 g: 20-25 mL: 10-15 mL: 100-200 mL: 25-30 mL.

[0028] As a further embodiment of the present invention: the preparation method of phenylated mesoporous silica comprises the following steps:

[0029] Add hexadecyltrimethylammonium chloride, deionized water and triethanolamine into a reaction bottle and disperse them evenly. Control the temperature at 90-100°C, add ethyl orthosilicate and phenyltrimethoxysilane, keep the temperature for 2-4 hours, centrifuge, wash with ethanol, remove the hexadecyltrimethylammonium chloride, and dry to obtain phenylated mesoporous silica.

[0030] As a further solution of the present invention: the specific steps of washing and removing hexadecyltrimethylammonium chloride are: 1 mL of 1 mol / L hydrochloric acid aqueous solution and 10 mL of anhydrous ethanol are mixed to obtain acidic ethanol, the material is placed in the acidic ethanol and refluxed at 80° C. for 12 hours, and the reflux washing is repeated three times.

[0031] As a further solution of the present invention: the addition ratio of hexadecyltrimethylammonium chloride, deionized water, triethanolamine, ethyl orthosilicate, and phenyltrimethoxysilane is 15-20 g: 500-1000 mL: 2.5-4 g: 70 g: 20-50 g.

[0032] As a further solution of the present invention: the optical film layer includes a diffusion film and a brightness enhancement film, and the diffusion film is arranged between the substrate plate and the brightness enhancement film.

[0033] As a further solution of the present invention: the substrate plate is a transparent plate such as PS (polystyrene), PMMA (polymethyl methacrylate, commonly known as organic glass), PC (polycarbonate), PMA (polyoxymethylene ester), PI (polyimide), etc.

[0034] As a further solution of the present invention: the diffusion film or diffusion plate is a light-transmitting synthetic material such as PS (polystyrene), glass, PE (polyethylene), PVC (polyvinyl chloride), PP (polypropylene), PC (polycarbonate), PET (polyethylene terephthalate), MMA (acrylic acid), PMMA (polymethyl methacrylate, commonly known as organic glass); the diffusion film or diffusion plate mainly uses chemical and physical principles to utilize the physical phenomena of reflection, scattering and refraction when light encounters two media with different refractive indices during propagation. By filling organic or organic light scattering agents in the diffusion film or diffusion plate and adjusting the light through the microstructure on the surface of the plate, the light is reflected, refracted and scattered in different directions, thereby changing the light's travel path and achieving sufficient dispersion of the incident light to produce a uniform optical diffusion effect.

[0035] Beneficial effects of the present invention:

[0036] (1) The present application uses tetraethyl orthosilicate as a silicon source, hexadecyltrimethylammonium bromide as a structural template, and phenyltrimethoxysilane as a coupling agent to synthesize phenyl-functionalized mesoporous silica in one step according to co-hydrolysis and polycondensation, namely, phenylated mesoporous silica; the phenylated mesoporous silica prepared in the present application has a pore structure, and the phenyl groups are bonded to the pore surface to form an inorganic / organic mesoporous composite material, and the mesoporous silica with a high bonding amount has strong hydrophobicity and thermal stability; the present application uses tin tetrachloride as a catalyst to make the benzene rings on the phenylated mesoporous silica bond with chlorinated benzene. A Friedel-Crafts acylation reaction occurs between the acyl chloride groups of the trianhydride, and after the reaction is completed, the material is washed with water to hydrolyze and ring-open the acid anhydride grafted on the material, so that a carboxyl functional group and a benzene ring are grafted on the obtained component one; the present application utilizes bis(trichloromethyl) carbonate to chlorinate the carboxyl functional group on component one to obtain component two; the present application utilizes the acyl chloride group of component two to react with the hydroxyl group of 2-hydroxyethyl disulfide compound to graft a monomer containing a disulfide bond on the surface of the material, and uses the reducing agent dithiothreitol to reduce the disulfide bond to a thiol group to obtain modified mesoporous silica.

[0037] The present application utilizes the concentration difference between the inside and outside of the modified mesoporous silica and the thiol, carboxyl and phenyl groups in the pores of the modified mesoporous silica, and utilizes the covalent connection effect of the thiol groups on the quantum dots to embed the green quantum dots and the red quantum dots into the pores of the modified mesoporous silica, respectively, to obtain red quantum dot materials and green quantum dot materials. The present application prepares red quantum dot materials and green quantum dot materials to solve the chemical compatibility problems and water and oxygen corrosion problems of quantum dots in packaging. The phenyl and carboxyl groups in the pores of the modified mesoporous silica in the present application effectively interact with the quantum dots to increase the fluorescence yield of the quantum dots, effectively solving the problem that the chemical structure of the quantum dots is easily destroyed during the packaging process, resulting in luminescence quenching, and it is difficult to achieve a high-quality white light spectrum.

[0038] This application adopts a side-entry backlight source, and the red / green quantum dots are loaded in the modified mesoporous silica pores to obtain red / green quantum dot materials, and the red / green quantum dot materials are appropriately proportioned, and then evenly mixed with special inks to form quantum dot inks, and then the quantum dot inks are transferred to the lower surface of the light guide plate by screen printing, and after low-temperature drying, a quantum dot mesh microstructure is obtained. The quantum dots in the mesh are protected by modified mesoporous silica to prevent the quantum dots from being corroded by water and oxygen, and the quantum dots are prevented from being corroded by environmental factors, thereby improving the stability of the device. This method can not only effectively solve the influence of heat on quantum dots, but also does not require a dedicated quantum dot diaphragm to adjust the white balance of the light output.

[0039] (2) The process for preparing a quantum dot functional printed light guide plate provided by the present invention includes fixing a screen printing plate on a printing machine, placing a substrate plate under the printing plate, pouring quantum dot ink, applying pressure with a scraper, and squeezing the ink through the mesh of the pattern part onto the substrate to obtain a quantum dot functional layer; the present application provides a quantum dot functional layer prepared by screen printing quantum dot ink on a transparent light guide plate by screen printing quantum dot ink to achieve high-efficiency white light emission. The present application further improves the light efficiency and uniformity of the light guide plate by setting an optical film layer on the light emitting surface.

[0040] When the light guide plate of the present application is excited by blue light, the quantum dot functional layer can be effectively converted into white light with a wide color gamut, thereby improving the color expression; the quantum dot functional layer prepared by the quantum dot ink prepared in the present application and applied to the light guide plate has the advantages of high light efficiency and simple preparation process, and is suitable for use in high-end display devices and lighting systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below in conjunction with the accompanying drawings.

[0042] Figure 1 This is a structural breakdown diagram of the quantum dot functional printed light guide plate prepared in this application. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1 The preparation method of modified mesoporous silica comprises the following steps:

[0045] B1: 15g hexadecyltrimethylammonium chloride, 500mL deionized water, and 2.5g triethanolamine were added to a reaction bottle and dispersed evenly. The temperature was controlled at 90°C, 70g ethyl orthosilicate and 20g phenyltrimethoxysilane were added, and the reaction was kept warm for 2h. The mixture was centrifuged, washed with ethanol, and 1mL 1mol / L hydrochloric acid aqueous solution and 10mL anhydrous ethanol were blended to obtain acidic ethanol. The material was placed in the acidic ethanol and refluxed at 80°C for 12h. The reflux washing was repeated three times to remove the hexadecyltrimethylammonium chloride, and the mixture was dried to obtain phenylated mesoporous silica.

[0046] B2: Add 10g of phenylated mesoporous silica, 200mL of chloroform, 100mL of N,N-dimethylacetamide, 10g of chlorotrimellitic anhydride, and 15mL of tin tetrachloride into reactor A and disperse evenly, react at room temperature for 3h, filter under reduced pressure, wash with water, and dry to obtain component 1;

[0047] B3: In a nitrogen atmosphere, 15 g of bis(trichloromethyl) carbonate and 150 mL of carbon tetrachloride component 1 were added to reactor B and dispersed evenly, and the temperature was controlled at 0-5°C. 10 g of component 1 and 20 mL of ethanol were mixed and added to reactor B and dispersed evenly. 3 g of triethylamine and 20 mL of carbon tetrachloride component 2 were mixed and added to reactor B and dispersed evenly. The temperature was controlled at 50°C, and the reaction was kept warm for 9 hours. Filtered, washed with ethanol, and dried to obtain component 2.

[0048] B4: Add 10g of component 2, 20mL of 2-hydroxyethyl disulfide, 10mL of triethylamine and 100mL of tetrahydrofuran into reactor C and disperse them evenly. Control the temperature at 0℃ and keep the reaction for 1h. Adjust the pH to 8. In a nitrogen atmosphere, add 25mL of dithiothreitol. Control the temperature at 30℃ and keep the reaction for 1-3h. Rotary evaporate, wash with ether and dry to obtain modified mesoporous silica.

[0049] Example 2 The preparation method of modified mesoporous silica comprises the following steps:

[0050] B1: 17g hexadecyltrimethylammonium chloride, 700mL deionized water, and 3.2g triethanolamine were added to a reaction bottle and dispersed evenly. The temperature was controlled at 95°C, 70g ethyl orthosilicate and 35g phenyltrimethoxysilane were added, and the reaction was kept warm for 3h. The mixture was centrifuged, washed with ethanol, and 1mL 1mol / L hydrochloric acid aqueous solution and 10mL anhydrous ethanol were blended to obtain acidic ethanol. The material was placed in the acidic ethanol and refluxed at 80°C for 12h. The reflux washing was repeated three times to remove the hexadecyltrimethylammonium chloride, and dried to obtain phenylated mesoporous silica.

[0051] B2: 10 g of phenylated mesoporous silica, 300 mL of chloroform, 150 mL of N,N-dimethylacetamide, 20 g of chlorotrimellitic anhydride, and 20 mL of tin tetrachloride were added to reactor A and dispersed evenly. The mixture was reacted at room temperature for 4 h, and then filtered under reduced pressure, washed with water, and dried to obtain component 1.

[0052] B3: In a nitrogen atmosphere, 20 g of bis(trichloromethyl) carbonate and 200 mL of carbon tetrachloride component 1 were added to reactor B and dispersed evenly, and the temperature was controlled at 0°C. 10 g of component 1 and 25 mL of ethanol were mixed and added to reactor B and dispersed evenly. 4 g of triethylamine and 30 mL of carbon tetrachloride component 2 were mixed and added to reactor B and dispersed evenly. The temperature was controlled at 55°C, and the reaction was kept warm for 12 hours. Filtered, washed with ethanol, and dried to obtain component 2.

[0053] B4: Add 10g of component 2, 20mL of 2-hydroxyethyl disulfide, 15mL of triethylamine and 200mL of tetrahydrofuran into reactor C and disperse them evenly. Control the temperature at 0℃ and keep the reaction for 3h. Adjust the pH to 8. In a nitrogen atmosphere, add 30mL of dithiothreitol. Control the temperature at 40℃ and keep the reaction for 3h. Rotary evaporate, wash with ether and dry to obtain modified mesoporous silica.

[0054] Example 3 The preparation method of modified mesoporous silica comprises the following steps:

[0055] B1: 20g hexadecyltrimethylammonium chloride, 1000mL deionized water, and 4g triethanolamine were added to a reaction bottle and dispersed evenly, the temperature was controlled at 100°C, 70g ethyl orthosilicate and 50g phenyltrimethoxysilane were added, and the mixture was kept warm for 4h, centrifuged, washed with ethanol, and 1mL 1mol / L hydrochloric acid aqueous solution and 10mL anhydrous ethanol were blended to obtain acidic ethanol, the material was placed in the acidic ethanol and refluxed at 80°C for 12h, and the reflux washing was repeated three times to remove the hexadecyltrimethylammonium chloride, and dried to obtain phenylated mesoporous silica;

[0056] B2: 10 g of phenylated mesoporous silica, 400 mL of chloroform, 200 mL of N,N-dimethylacetamide, 30 g of chlorotrimellitic anhydride, and 25 mL of tin tetrachloride were added to reaction kettle A and dispersed evenly. The mixture was reacted at room temperature for 6 h, filtered under reduced pressure, washed with water, and dried to obtain component 1.

[0057] B3: In a nitrogen atmosphere, 30 g of bis(trichloromethyl) carbonate and 200 mL of carbon tetrachloride component 1 were added to reactor B and dispersed evenly. The temperature was controlled at 5°C. 10 g of component 1 and 30 mL of ethanol were mixed and added to reactor B and dispersed evenly. 5 g of triethylamine and 40 mL of carbon tetrachloride component 2 were mixed and added to reactor B and dispersed evenly. The temperature was controlled at 60°C. The reaction was kept warm for 15 hours, filtered, washed with ethanol, and dried to obtain component 2.

[0058] B4: Add 10g of component 2, 25mL of 2-hydroxyethyl disulfide, 15mL of triethylamine and 200mL of tetrahydrofuran into reactor C and disperse them evenly. Control the temperature at 5°C and keep the reaction for 3h. Adjust the pH to 9. Add 30mL of dithiothreitol in a nitrogen atmosphere. Control the temperature at 40°C and keep the reaction for 3h. Rotary evaporate, wash with ether and dry to obtain modified mesoporous silica.

[0059] Example 4 The preparation method of quantum dot ink comprises the following steps:

[0060] A1: 0.5 g of green quantum dots (green light CdSe / ZnS quantum dots, emission wavelength 525 nm), 1 g of modified mesoporous silica prepared in Example 1, and 10 mL of n-hexane were added to a reaction kettle D, the temperature was controlled at 60° C., the pH was adjusted to 5, the mixture was stirred and kept warm to evaporate the solvent, and then dried to obtain a green quantum dot material;

[0061] A2: 0.5 g of red quantum dots (red light CdSe / ZnS quantum dots, emission wavelength 610 nm), 1 g of modified mesoporous silica prepared in Example 1, and 10 mL of n-hexane were added to reactor E, the temperature was controlled at 60° C., the pH was adjusted to 5, the mixture was stirred and kept warm to evaporate the solvent, and then dried to obtain a red quantum dot material;

[0062] A3: Mix 13 g of green quantum dot material and 10 mL of cyclohexane to obtain a green quantum dot material solution;

[0063] A4: Mix 1 g of red quantum dot material and 10 mL of cyclohexane to obtain a red quantum dot material solution;

[0064] A5: Mix the green quantum dot material solution, the red quantum dot material solution and 10 mL of UV glue (purchased from Nolan NOA68, USA) to obtain quantum dot ink.

[0065] Example 5 The preparation method of quantum dot ink comprises the following steps:

[0066] A1: 0.5 g of green quantum dots (green light CdSe / ZnS quantum dots, emission wavelength 525 nm), 1 g of modified mesoporous silica prepared in Example 2, and 10 mL of n-hexane were added to a reaction kettle D, the temperature was controlled at 60°C, the pH was adjusted to 5, the solvent was stirred and kept warm to evaporate and dry, and a green quantum dot material was obtained;

[0067] A2: 0.5 g of red quantum dots (red light CdSe / ZnS quantum dots, emission wavelength 610 nm), 1 g of modified mesoporous silica prepared in Example 2, and 10 mL of n-hexane were added to reactor E, the temperature was controlled at 60° C., the pH was adjusted to 5, the mixture was stirred and kept warm to evaporate the solvent, and then dried to obtain a red quantum dot material;

[0068] A3: Mix 13 g of green quantum dot material and 10 mL of cyclohexane to obtain a green quantum dot material solution;

[0069] A4: Mix 1 g of red quantum dot material and 10 mL of cyclohexane to obtain a red quantum dot material solution;

[0070] A5: Mix the green quantum dot material solution, the red quantum dot material solution and 10 mL of UV glue (purchased from Nolan NOA68, USA) to obtain quantum dot ink.

[0071] Example 6 The preparation method of quantum dot ink comprises the following steps:

[0072] A1: 0.5 g of green quantum dots (green light CdSe / ZnS quantum dots, emission wavelength 525 nm), 1 g of modified mesoporous silica prepared in Example 3, and 10 mL of n-hexane were added to a reaction kettle D, the temperature was controlled at 60°C, the pH was adjusted to 5, the mixture was stirred and kept warm to evaporate the solvent, and then dried to obtain a green quantum dot material;

[0073] A2: 0.5 g of red quantum dots (red light CdSe / ZnS quantum dots, emission wavelength 610 nm), 1 g of modified mesoporous silica prepared in Example 3, and 10 mL of n-hexane were added to reactor E, the temperature was controlled at 60° C., the pH was adjusted to 5, the mixture was stirred and kept warm to evaporate the solvent, and then dried to obtain a red quantum dot material;

[0074] A3: Mix 13 g of green quantum dot material and 10 mL of cyclohexane to obtain a green quantum dot material solution;

[0075] A4: Mix 1 g of red quantum dot material and 10 mL of cyclohexane to obtain a red quantum dot material solution;

[0076] A5: Mix the green quantum dot material solution, the red quantum dot material solution and 10 mL of UV glue (purchased from Nolan NOA68, USA) to obtain quantum dot ink.

[0077] Example 7 Please refer to Figure 1 , a method for preparing a quantum dot functional printed light guide plate, comprising the following steps:

[0078] S1: The quantum dot ink prepared in Example 4 was printed on the opposite side of the light-emitting surface of the PMMA substrate using a screen printing process, dried (70°C, 2h), and UV-cured (light intensity 180W / cm 2 , curing for 15s), to obtain a quantum dot functional layer;

[0079] S2: A reflective film (thickness 0.1 mm, transmittance 96%) is added to the quantum dot functional layer, a diffusion film (thickness 0.1 mm, transmittance 100%) is added to the light emitting surface of the substrate plate, and a brightness enhancement film (3M double-layer film, BEF90-40) is set on the surface of the diffusion film to obtain a quantum dot functional printed light guide plate.

[0080] Example 8 Please refer to Figure 1 , a method for preparing a quantum dot functional printed light guide plate, comprising the following steps:

[0081] S1: The quantum dot ink prepared in Example 5 was printed on the opposite side of the light-emitting surface of the PMMA substrate using a screen printing process, dried (70°C, 2h), UV-cured (light intensity 180W / cm2 , curing for 15s), obtaining a quantum dot functional layer;

[0082] S2: A reflective film (thickness 0.1 mm, transmittance 96%) is added to the quantum dot functional layer, a diffusion film (thickness 0.1 mm, transmittance 100%) is added to the light emitting surface of the substrate plate, and a brightness enhancement film (3M double-layer film, BEF90-40) is set on the surface of the diffusion film to obtain a quantum dot functional printed light guide plate.

[0083] Example 9 Please refer to Figure 1 , a method for preparing a quantum dot functional printed light guide plate, comprising the following steps:

[0084] S1: The quantum dot ink prepared in Example 6 was printed on the opposite side of the light-emitting surface of the PMMA substrate using a screen printing process, dried (70°C, 2h), and UV-cured (light intensity 180W / cm 2 , curing for 15s), obtaining a quantum dot functional layer;

[0085] S2: A reflective film (thickness 0.1 mm, transmittance 96%) is added to the quantum dot functional layer, a diffusion film (thickness 0.1 mm, transmittance 100%) is added to the light emitting surface of the substrate plate, and a brightness enhancement film (3M double-layer film, BEF90-40) is set on the surface of the diffusion film to obtain a quantum dot functional printed light guide plate.

[0086] Comparative Example 1 A method for preparing modified mesoporous silica comprises the following steps: adding 17 g of hexadecyltrimethylammonium chloride, 700 mL of deionized water, and 3.2 g of triethanolamine into a reaction bottle and dispersing them evenly, controlling the temperature at 95°C, adding 70 g of ethyl orthosilicate and 35 g of mercaptopropyltrimethoxysilane, and reacting by heat preservation for 3 hours, centrifuging, washing with ethanol, and blending 1 mL of a 1 mol / L aqueous hydrochloric acid solution and 10 mL of anhydrous ethanol to obtain acidic ethanol, placing the material in the acidic ethanol and refluxing at 80°C for 12 hours, repeating the reflux washing three times to remove the hexadecyltrimethylammonium chloride, and drying to obtain modified mesoporous silica.

[0087] Comparative Example 2 The preparation method of modified mesoporous silica comprises the following steps:

[0088] A1: 17g hexadecyltrimethylammonium chloride, 700mL deionized water, and 3.2g triethanolamine were added to a reaction bottle and dispersed evenly. The temperature was controlled at 95°C, 70g ethyl orthosilicate and 35g phenyltrimethoxysilane were added, and the reaction was kept warm for 3h. The mixture was centrifuged, washed with ethanol, and 1mL 1mol / L hydrochloric acid aqueous solution and 10mL anhydrous ethanol were blended to obtain acidic ethanol. The material was placed in the acidic ethanol and refluxed at 80°C for 12h. The reflux washing was repeated three times to remove the hexadecyltrimethylammonium chloride, and dried to obtain phenylated mesoporous silica.

[0089] A2: Add 10 g of phenylated mesoporous silica, 300 mL of chloroform, 150 mL of N,N-dimethylacetamide, 20 g of chlorotrimellitic anhydride, and 20 mL of tin tetrachloride into reactor A and disperse evenly. React at room temperature for 4 h, filter under reduced pressure, wash with water, and dry to obtain modified mesoporous silica.

[0090] Comparative Example 3 The preparation method of modified mesoporous silica comprises the following steps:

[0091] A1: 17g hexadecyltrimethylammonium chloride, 700mL deionized water, and 3.2g triethanolamine were added to a reaction bottle and dispersed evenly. The temperature was controlled at 95°C, 70g ethyl orthosilicate and 35g phenyltrimethoxysilane were added, and the reaction was kept warm for 3h. The mixture was centrifuged, washed with ethanol, and 1mL 1mol / L hydrochloric acid aqueous solution and 10mL anhydrous ethanol were blended to obtain acidic ethanol. The material was placed in the acidic ethanol and refluxed at 80°C for 12h. The reflux washing was repeated three times to remove the hexadecyltrimethylammonium chloride, and dried to obtain phenylated mesoporous silica.

[0092] A2: 10 g of phenylated mesoporous silica, 300 mL of chloroform, 150 mL of N,N-dimethylacetamide, 20 g of chlorotrimellitic anhydride, and 20 mL of tin tetrachloride were added to reaction kettle A and dispersed evenly. The mixture was reacted at room temperature for 4 h, and then filtered under reduced pressure, washed with water, and dried to obtain component 1.

[0093] A3: In a nitrogen atmosphere, 20 g of bis(trichloromethyl) carbonate and 200 mL of carbon tetrachloride component one were added to reactor B and dispersed evenly. The temperature was controlled at 0°C. 10 g of component one and 25 mL of ethanol were mixed and added to reactor B and dispersed evenly. 4 g of triethylamine and 30 mL of carbon tetrachloride component two were mixed and added to reactor B and dispersed evenly. The temperature was controlled at 55°C. The reaction was kept warm for 12 hours, filtered, washed with ethanol, and dried to obtain modified mesoporous silica.

[0094] Comparative Example 4 The preparation method of quantum dot ink comprises the following steps:

[0095] A1: Add 0.5 g of green quantum dots (green light CdSe / ZnS quantum dots, emission wavelength 525 nm), 1 g of modified mesoporous silica prepared in Comparative Example 1, and 10 mL of n-hexane into a reaction kettle D, control the temperature to 60°C, adjust the pH to 5, keep warm and stir to evaporate the solvent, and dry to obtain a green quantum dot material;

[0096] A2: 0.5 g of red quantum dots (red light CdSe / ZnS quantum dots, emission wavelength 610 nm), 1 g of modified mesoporous silica prepared in Comparative Example 1, and 10 mL of n-hexane were added to reactor E, the temperature was controlled at 60°C, the pH was adjusted to 5, the solvent was stirred and kept warm to evaporate and dry, and a red quantum dot material was obtained;

[0097] A3: Mix 13 g of green quantum dot material and 10 mL of cyclohexane to obtain a green quantum dot material solution;

[0098] A4: Mix 1 g of red quantum dot material and 10 mL of cyclohexane to obtain a red quantum dot material solution;

[0099] A5: Mix the green quantum dot material solution, the red quantum dot material solution and 10 mL of UV glue (purchased from Nolan NOA68, USA) to obtain quantum dot ink.

[0100] Comparative Example 5 The preparation method of quantum dot ink comprises the following steps:

[0101] A1: Add 0.5 g of green quantum dots (green light CdSe / ZnS quantum dots, emission wavelength 525 nm), 1 g of modified mesoporous silica prepared in Comparative Example 2, and 10 mL of n-hexane into reactor D, control the temperature to 60°C, adjust the pH to 5, keep warm and stir to evaporate the solvent, and dry to obtain a green quantum dot material;

[0102] A2: 0.5 g of red quantum dots (red light CdSe / ZnS quantum dots, emission wavelength 610 nm), 1 g of modified mesoporous silica prepared in Comparative Example 2, and 10 mL of n-hexane were added to reactor E, the temperature was controlled at 60°C, the pH was adjusted to 5, the solvent was stirred and kept warm to evaporate and dry, and a red quantum dot material was obtained;

[0103] A3: Mix 13 g of green quantum dot material and 10 mL of cyclohexane to obtain a green quantum dot material solution;

[0104] A4: Mix 1 g of red quantum dot material and 10 mL of cyclohexane to obtain a red quantum dot material solution;

[0105] A5: Mix the green quantum dot material solution, the red quantum dot material solution and 10 mL of UV glue (purchased from Nolan NOA68, USA) to obtain quantum dot ink.

[0106] Comparative Example 6 The preparation method of quantum dot ink comprises the following steps:

[0107] A1: Add 0.5 g of green quantum dots (green light CdSe / ZnS quantum dots, emission wavelength 525 nm), 1 g of modified mesoporous silica prepared in Comparative Example 3, and 10 mL of n-hexane into reactor D, control the temperature to 60°C, adjust the pH to 5, keep warm and stir to evaporate the solvent, and dry to obtain a green quantum dot material;

[0108] A2: 0.5 g of red quantum dots (red light CdSe / ZnS quantum dots, emission wavelength 610 nm), 1 g of modified mesoporous silica prepared in Comparative Example 3, and 10 mL of n-hexane were added to reactor E, the temperature was controlled at 60°C, the pH was adjusted to 5, the solvent was stirred and kept warm to evaporate and dry, and a red quantum dot material was obtained;

[0109] A3: Mix 13 g of green quantum dot material and 10 mL of cyclohexane to obtain a green quantum dot material solution;

[0110] A4: Mix 1 g of red quantum dot material and 10 mL of cyclohexane to obtain a red quantum dot material solution;

[0111] A5: Mix the green quantum dot material solution, the red quantum dot material solution and 10 mL of UV glue (purchased from Nolan NOA68, USA) to obtain quantum dot ink.

[0112] Comparative Example 7 Compared with Example 7, only the quantum dot ink prepared in Example 4 used in Example 7 is replaced by the quantum dot ink prepared in Comparative Example 4 in equal amounts, and the remaining components and preparation method of Comparative Example 7 are completely consistent with those of Example 7.

[0113] Comparative Example 8 Compared with Example 7, only the quantum dot ink prepared in Example 4 used in Example 7 is replaced by the quantum dot ink prepared in Comparative Example 5 in equal amounts. The remaining components and preparation method of Comparative Example 8 are completely consistent with those of Example 7.

[0114] Comparative Example 9 Compared with Example 7, only the quantum dot ink prepared in Example 4 used in Example 7 is replaced by the quantum dot ink prepared in Comparative Example 6 in equal amounts. The remaining components and preparation method of Comparative Example 9 are completely consistent with those of Example 7.

[0115] Performance Testing

[0116] (1) Light stability: The luminous power is tested using the Yuanfang YF1000 optical radiation comprehensive test system test platform;

[0117] ① Water and oxygen aging: The light guide plates prepared in Examples 7-9 and Comparative Examples 7-9 were placed in a test box, and the test box environment was set to 85°C and 85RH%, and treated for 120 hours. The luminous intensity preservation rate of the materials before and after the water and oxygen aging treatment was tested. The test results are shown in Table 1;

[0118] ② Conventional use aging: In a room temperature environment, one side of the light guide plate prepared in Example 7-9 and Comparative Example 7-9 was illuminated with blue light for 500 hours, and the luminous intensity preservation rate of the material before and after the lighting aging treatment was tested. The test results are shown in Table 1;

[0119] Table 1: Statistical table of photostability test data of inks of Examples 7-9 and Comparative Examples 7-9

[0120]

[0121] As can be seen from Table 1, the present application loads green quantum dots and red quantum dots in the pores of modified mesoporous silica, which effectively improves the light stability of quantum dots, and effectively improves the resistance to water and oxygen corrosion and lighting aging performance of quantum dots. It prevents quantum dots from being corroded by environmental factors and improves device stability.

[0122] (2) Optical properties: The optical properties were measured according to the optical test platform in GB / T 42976-2023 (the dot coverage of the light guide plates prepared in Examples 7-9 and Comparative Examples 7-9 was 0.16π%), and the following steps were followed:

[0123] a): Complete the backlight debugging of the test bench and wait for 15 minutes for the light source to stabilize;

[0124] b): Install the sample and diffusion membrane on the test platform;

[0125] c): Place the spectroradiometer in the normal direction of the sample stage, test the brightness (L), CIE color coordinates (X), and CIE color coordinates (Y) in turn according to the nine-equal standard measurement positions of the ANSI standard, and record the test results;

[0126] d): After completion, perform brightness uniformity L according to the following formula U calculate:

[0127] L U =Lmin / Lmax

[0128] Where, L U -Brightness uniformity, %; Lmax-maximum brightness; Lmin-minimum brightness; the test results are shown in Table 2;

[0129] Table 2: Statistical table of performance test data of Examples 7-9 and Comparative Examples 7-9

[0130]

[0131] As shown in Table 2, the brightness of the light guide plate prepared in this application can reach 4671cd / m 2 As shown above, the color coordinates are very close to the standard white light color coordinates (0.33, 0.33). The quantum dot ink prepared in this application is applied in the light guide plate to achieve excellent luminescence and color performance.

[0132] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a quantum dot functional printed light guide plate, characterized in that: The steps include: S1: Printing quantum dot ink on the opposite side of the light-emitting surface of the substrate plate by screen printing, drying, and UV curing to obtain a quantum dot functional layer; S2: adding a reflective film on the quantum dot functional layer and adding an optical film layer on the light emitting surface of the substrate plate to obtain a quantum dot functional printed light guide plate; The preparation method of quantum dot ink comprises the following steps: A1: mixing a green quantum dot material and a solvent to obtain a green quantum dot material solution; A2: Mixing red quantum dot material and solvent to obtain a red quantum dot material solution; A3: Mix the green quantum dot material solution, the red quantum dot material solution and the UV glue to obtain quantum dot ink; The green quantum dot material is obtained by loading green quantum dots on modified mesoporous silica; the red quantum dot material is obtained by loading red quantum dots on modified mesoporous silica; The preparation method of the modified mesoporous silica comprises the following steps: B1: Add phenylated mesoporous silica, chloroform, N,N-dimethylacetamide, chlorotrimellitic anhydride and tin tetrachloride into reactor A and disperse evenly, react at room temperature for 3-6 hours, filter under reduced pressure, wash with water and dry to obtain component 1; B2: In a nitrogen atmosphere, add bis(trichloromethyl) carbonate and carbon tetrachloride component 1 to reactor B and disperse them evenly, control the temperature at 0-5°C, mix component 1 and ethanol and add them to reactor B and disperse them evenly, mix triethylamine and carbon tetrachloride component 2 and add them to reactor B and disperse them evenly, control the temperature at 50-60°C, keep the reaction warm for 9-15h, filter, wash with ethanol, and dry to obtain component 2; B3: Add components two, 2-hydroxyethyl disulfide, triethylamine, and tetrahydrofuran into reactor C and disperse them evenly. Control the temperature at 0-5°C, keep the reaction warm for 1-3 hours, adjust the pH to 8-9, add dithiothreitol in a nitrogen atmosphere, control the temperature at 30-40°C, keep the reaction warm for 1-3 hours, rotary evaporate, wash with ether, and dry to obtain modified mesoporous silica.

2. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The mass ratio of red quantum dot material: green quantum dot material in quantum dot ink is 1:9-13; the green quantum dot material and the red quantum dot material together account for 20-40% of the total mass of the quantum dot ink; the volume ratio of solvent: UV glue in the quantum dot ink is 2:

1.

3. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The specific steps of loading the green quantum dots on the modified mesoporous silica are: 0.2-0.5 g of green quantum dots, 1 g of modified mesoporous silica, and 3-10 mL of n-hexane were added to a reaction kettle D, the temperature was controlled at 60-70° C., the pH was adjusted to 5-6, and the mixture was stirred and heated to evaporate the solvent and dry to obtain a green quantum dot material.

4. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The specific steps of loading the red quantum dots on the modified mesoporous silica are: 0.2-0.5 g red quantum dots, 1 g modified mesoporous silica, and 3-10 mL n-hexane were added into reactor E, the temperature was controlled at 60-70° C., the pH was adjusted to 5-6, and the mixture was stirred and heated to evaporate the solvent and dry to obtain red quantum dot material.

5. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The addition ratio of phenylated mesoporous silica, chloroform, N,N-dimethylacetamide, chlorotrimellitic anhydride, and tin tetrachloride in B1 is 1 g: 20-40 mL: 10-20 mL: 1-3 g: 1.5-2.5 mL.

6. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The carbon tetrachloride component 1 and the carbon tetrachloride component 2 in B2 are both carbon tetrachloride; the addition ratio of bis(trichloromethyl) carbonate, carbon tetrachloride component 1, component 1, ethanol, triethylamine, and carbon tetrachloride component 2 is 15-30g: 150-200mL: 10g: 20-30mL: 3-5g: 20-40mL.

7. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The addition ratio of component 2, 2-hydroxyethyl disulfide, triethylamine, tetrahydrofuran, and dithiothreitol in B3 is 10g:20-25mL:10-15mL:100-200mL:25-30mL.

8. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The preparation method of the phenylated mesoporous silica comprises the following steps: Add hexadecyltrimethylammonium chloride, deionized water and triethanolamine into a reaction bottle and disperse them evenly. Control the temperature at 90-100°C, add ethyl orthosilicate and phenyltrimethoxysilane, keep the temperature for 2-4 hours, centrifuge, wash with ethanol, remove the hexadecyltrimethylammonium chloride, and dry to obtain phenylated mesoporous silica.

9. The method for preparing a quantum dot functional printed light guide plate according to claim 8, characterized in that: The addition ratio of hexadecyltrimethylammonium chloride, deionized water, triethanolamine, ethyl orthosilicate, and phenyltrimethoxysilane is 15-20g: 500-1000mL: 2.5-4g: 70g: 20-50g.

10. The method for preparing a quantum dot functional printed light guide plate according to claim 1, characterized in that: The optical film layer comprises a diffusion film and a brightness enhancement film, and the diffusion film is arranged between the substrate plate and the brightness enhancement film.

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