Curable resin composition

Abstract

To provide a highly reliable curable resin composition containing quantum dots in which the quantum dots can be dispersed in a curable resin at a high concentration without aggregation.SOLUTION: The present invention provides a curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a thermosetting resin and a silsesquioxane polymer in which the quantum dots are copolymerized with silsesquioxane.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable resin composition containing quantum dots.

Background Art

[0002] Semiconductor crystal particles with a nanosize particle diameter are called quantum dots. Due to the excitons generated by light absorption being confined in a nanosize region, the energy levels of the semiconductor crystal particles become discrete, and their bandgap changes depending on the particle diameter. Due to these effects, the fluorescence emission of quantum dots is high-brightness, high-efficiency, and the emission is sharp compared to general phosphors. Also, it has the characteristic that the emission wavelength can be controlled due to the change in the bandgap depending on the particle diameter, and it is expected to be applied as a wavelength conversion material for solid lighting and displays. For example, by using quantum dots as a wavelength conversion material in a display, a wider color gamut and lower power consumption can be achieved compared to conventional phosphor materials.

[0003] As a mounting method in which quantum dots are used as a wavelength conversion material, a method has been proposed in which quantum dots are dispersed in a resin material and a resin material containing quantum dots is laminated with a transparent film and then incorporated into a backlight unit as a wavelength conversion film (Patent Document 1). Also, by using quantum dots as a color filter material, the quantum dots absorb blue monochromatic light from a backlight unit and emit red or green light, thereby functioning as a color filter and a wavelength conversion material, and it has also been proposed to apply it to pixel elements with high efficiency and excellent color reproducibility (Patent Document 2). Micro-LED displays, which replace the backlight unit with a micro-sized LED array, are attracting attention. In micro-LED displays, it is necessary to form color filters on micro-sized LEDs. A lithography process using a curable material has been proposed as a method for forming quantum dot color filters on an LED array (Patent Document 3). In recent years, the size of these LED arrays has been miniaturized, and finer patterning of quantum dots than before is required. In addition, for color filter applications, it is necessary to increase the light absorption amount of the color filter in order to suppress leakage of blue monochromatic light, which is the excitation light, from the color filter. Increasing the light absorption amount of the color filter requires increasing the quantum dot density. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2013-544018 [Patent Document 2] Japanese Patent Publication No. 2017-021322 [Patent Document 3] Japanese Patent Publication No. 2021-089347 [Patent Document 4] Special Publication No. 2016-518468 [Patent Document 5] Special Publication No. 2013-505346 [Patent Document 6] Patent No. 6283092 [Non-patent literature]

[0005] [Non-Patent Document 1] Journal of Photopolymer Science and Technology, Vol 23, 2010, p115-119 [Overview of the project] [Problems that the invention aims to solve]

[0006] Generally, curable resin materials such as acrylic resins and silicone resins are polar and dispersed in polar solvents such as PGMEA and PGME. Therefore, they have poor compatibility with quantum dots, which are inherently hydrophobic, and aggregation is a major problem. This aggregation problem becomes even more serious when the concentration of quantum dots is increased. Quantum dot aggregates inhibit the crosslinking of the resin during curing, reducing its curability. Furthermore, the presence of aggregates within the wavelength conversion material obtained by curing this resin composition can cause uneven emission intensity, negatively impacting product characteristics. While the addition of dispersants has been considered as a countermeasure against quantum dot aggregation, it has been found to reduce the quantum dot content and can cause curing inhibition and discoloration during the curing process of curable resins, altering the properties of the cured resin.

[0007] Furthermore, because the quantum dots in the cured resin composition are located within the resin material, unlike in a solution environment, ligand detachment and other processes are more likely to occur, and deterioration of their luminescence properties over time becomes a problem.

[0008] To address these problems, various methods have been attempted, such as surface coating of quantum dots (Patent Document 4), encapsulation (Patent Document 5), and binding of polyhedral oligomeric silsesquioxane ligands (Patent Document 6) to improve dispersibility in polar solvents and resin materials or enhance stability. However, it is difficult to achieve both dispersibility in resin materials, particularly suppression of aggregation and stability at high concentrations of 10 parts by mass or more of quantum dots, and the curability of the composition mixed with the resin.

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a highly reliable curable resin composition containing quantum dots that can disperse quantum dots at high concentrations in a curable resin without aggregation. [Means for solving the problem]

[0010] To solve the above problems, the present invention provides a curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane and a thermosetting resin.

[0011] Such a curable resin composition allows for the dispersion of quantum dots at high concentrations within the curable resin without aggregation, resulting in a highly reliable curable resin composition containing quantum dots.

[0012] Furthermore, the present invention provides a curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots and alkoxysilane, and a thermosetting resin.

[0013] Even with such a curable resin composition, quantum dots can be dispersed in the curable resin at high concentrations without aggregation, resulting in a highly reliable curable resin composition containing quantum dots.

[0014] Furthermore, in the present invention, it is preferable that the surface of the quantum dot is surface-modified with a silane coupling agent.

[0015] Such quantum dots are preferable because they readily copolymerize with silsesquioxanes and alkoxysilanes.

[0016] Furthermore, in the present invention, it is preferable that the alkoxysilane consists of two or more alkoxysilanes, each having a different functional group.

[0017] With such alkoxysilanes, the degree of crosslinking of the silsesquioxane obtained by copolymerization can be controlled, thereby controlling the viscosity of the resulting curable resin composition and allowing for viscosity adjustment according to the manufacturing process.

[0018] In the present invention, it is preferable that the alkoxysilane is composed of at least one type of alkoxysilane selected from monoalkoxysilane, dialkoxysilane, and trialkoxysilane.

[0019] Even with such an alkoxysilane, the crosslinking degree of the silsesquioxane obtained by copolymerization can be controlled, whereby the viscosity of the curable resin composition obtained can be controlled, and it becomes possible to adjust the viscosity according to the manufacturing process.

[0020] In the present invention, it is preferable that the silane coupling agent has at least one of an amino group, a thiol group, a carboxy group, a phosphino group, a phosphine oxide group, and an ammonium ion.

[0021] Such a silane coupling agent is preferable because it has a high coordination property to quantum dots and the affinity of quantum dots to silsesquioxane is improved. Further, it is also preferable because the polarities of the quantum dots and the silsesquioxane can be controlled, and the dispersibility with the curable resin can be improved by adjusting according to the polarity of the curable resin.

[0022] In the present invention, it is preferable that the silsesquioxane has at least one reactive substituent selected from a vinyl group, an acrylic group, a methacrylic group, a hydroxyl group, a phenolic hydroxyl group, an epoxy group, and a glycidyl group as a functional group.

[0023] Such a functional group is preferable from the viewpoint of improving the patterning property of the curable resin composition.

[0024] In the present invention, it is preferable that the alkoxysilane has at least one reactive substituent selected from a vinyl group, an acrylic group, a methacrylic group, a hydroxyl group, a phenolic hydroxyl group, an epoxy group, and a glycidyl group as a functional group. <00001​​Such functional groups are preferable from the viewpoint of improving the patternability of the curable resin composition.

[0026] Furthermore, in the present invention, it is preferable that the thermosetting resin is an acrylic resin having (meth)acryloyl groups in its side chains.

[0027] Such thermosetting resins can be suitably used in the curable resin composition of the present invention.

[0028] Furthermore, in the present invention, it is preferable that the thermosetting resin is an acid-crosslinkable group-containing silicone resin.

[0029] Such thermosetting resins can be suitably used in the curable resin composition of the present invention. [Effects of the Invention]

[0030] As described above, the curable resin composition of the present invention allows for the dispersion of quantum dots in the curable resin at high concentrations without aggregation, resulting in a highly reliable curable resin composition containing quantum dots. [Modes for carrying out the invention]

[0031] As described above, there has been a need for the development of a highly reliable curable resin composition containing quantum dots that can be dispersed in a curable resin at high concentrations without aggregation.

[0032] As a result of diligent research into the above-mentioned problems, the inventors conceived of mixing a silsesquioxane polymer, obtained by copolymerizing quantum dots and silsesquioxane, with a thermosetting resin, and thus completed the present invention.

[0033] In other words, the present invention relates to a curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane and a thermosetting resin.

[0034] Furthermore, the present invention relates to a curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots and alkoxysilane, and a thermosetting resin.

[0035] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0036] In the present invention, a silsesquioxane polymer obtained by copolymerizing quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing quantum dots and alkoxysilane, is not a polymer in which quantum dots are directly copolymerized with silsesquioxane or alkoxysilane, but rather a polymer obtained by copolymerizing ligands modified on the surface of quantum dots with silsesquioxane or alkoxysilane. That is, a polymer obtained by copolymerizing quantum dots having ligands on their surface with silsesquioxane or alkoxysilane.

[0037] In this invention, the composition and manufacturing method of the quantum dots are not particularly limited, and quantum dots can be selected according to the purpose. Examples of quantum dot compositions include group II-IV semiconductors, group III-V semiconductors, group II-VI semiconductors, group I-III-VI semiconductors, group II-IV-V semiconductors, group IV semiconductors, and perovskite semiconductors. Furthermore, quantum dots may consist only of a core or have a core-shell structure, and the particle size can be appropriately selected to match the desired wavelength range.

[0038] Specifically, examples of core materials include CdSe, CdS, CdTe, InP, InAs, InSb, AlP, AlAs, AlSb, ZnSe, ZnS, ZnTe, Zn3P2, GaP, GaAs, GaSb, CuInSe2, CuInS2, CuInTe2, CuGaSe2, CuGaS2, CuGaTe2, CuAlSe2, CuAlS2, CuAlTe2, AgInSe2, AgInS2, AgInTe, AgGaSe2, AgGaS2, AgGaTe2, PbSe, PbS, PbTe, Si, Ge, graphene, CsPbCl3, CsPbBr3, CsPbI3, CH3NH3PbCl3, and further examples include mixed crystals of these materials or materials with added dopants.

[0039] Examples of shell materials include ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, AlSb, BeS, BeSe, BeTe, MgS, MgSe, MgTe, PbS, PbSe, PbTe, SnS, SnSe, SnTe, CuF, CuCl, CuBr, CuI, and mixed crystals of these materials.

[0040] Furthermore, the quantum dots can be spherical, cubic, or rod-shaped. The shape of the quantum dots is not restricted and can be freely chosen. The average particle diameter of quantum dots should preferably be 20 nm or less. If the average particle diameter is 20 nm or less, the quantum size effect can be obtained, the luminescence efficiency will not decrease, and the band gap can be controlled by the particle size.

[0041] The particle size of quantum dots can be calculated by measuring particle images obtained using a transmission electron microscope (TEM) and averaging the maximum diameter in a given direction, i.e., the Ferret diameter, for 20 or more particles. Of course, the method for measuring the average particle size is not limited to this, and other methods are also possible.

[0042] Ligands may be present on the surface of the quantum dots, and from the viewpoint of dispersibility, the ligands preferably include aliphatic hydrocarbons. Examples of such ligands include oleic acid, stearic acid, palmitic acid, myristic acid, lauric acid, decanoic acid, octanoic acid, oleylamine, stearyl(octadecyl)amine, dodecyl(lauryl)amine, decylamine, octylamine, octadecanethiol, hexadecanethiol, tetradecanethiol, dodecanethiol, decanethiol, octanthiol, trioctylphosphine, trioctylphosphine oxide, triphenylphosphine, triphenylphosphine oxide, tributylphosphine, tributylphosphine oxide, etc., and these may be used individually or in combination.

[0043] The quantum dot surface can be modified using a silane coupling agent. Preferred silane coupling agents include those having amino groups, thiol groups, carboxyl groups, phosphino groups, phosphine oxide groups, and ammonium ions. Examples of silane coupling agents include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, aminophenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyl(dimethoxy)methylsilane, triethoxysilylpropylmaleamido acid, [(3-triethoxysilyl)propyl]succinic anhydride, X-12-1135 (manufactured by Shin-Etsu Chemical Co., Ltd.), diethylphosphatoethyltriethoxysilane, 3-trihydroxypropylmethylphosphonate sodium salt, and trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride.

[0044] In one embodiment, quantum dots surface-modified with a silane coupling agent can be copolymerized with silsesquioxane. The copolymerization method is not particularly limited. For example, the quantum dots and silsesquioxane can be copolymerized by mixing the surface-modified quantum dots and silsesquioxane in a mixed solvent of toluene and ethanol, and then adding a small amount of water and a catalyst to react. The type of catalyst is not particularly limited, and acids or alkalis can be used. Examples of catalysts include formic acid, hydrochloric acid, nitric acid, acetic acid, aqueous ammonia, and tetramethylammonium hydroxide.

[0045] Furthermore, the structure of silsesquioxane is not particularly limited and can be appropriately selected depending on the purpose, such as a cage structure, ladder structure, or random structure. A random structure is preferred from the viewpoint of dispersibility and uniformity in the curable resin. Also, the functional groups contained in silsesquioxane are not limited and may be appropriately substituted depending on the purpose. Substituents that can crosslink with the curable resin are particularly preferred from the viewpoint of improving the patternability of the curable resin composition. Examples of functional groups of silsesquioxane include vinyl groups, allyl groups, glycidyl groups, hydroxyl groups, phenol groups, acrylic groups, methacrylic groups, thiol groups, phenolic hydroxyl groups, and epoxy groups.

[0046] In one embodiment, a silsesquioxane polymer can be obtained by copolymerizing quantum dots surface-modified with a silane coupling agent with an alkoxysilane. The copolymerization method is not particularly limited. Methods for synthesizing silsesquioxane are known, such as those described in Non-Patent Document 1. For example, a silsesquioxane polymer can be obtained by mixing surface-modified quantum dots and an alkoxysilane in a mixed solvent of toluene and ethanol, and then reacting them with a small amount of water and a catalyst. The type and amount of catalyst added are not particularly limited, and acids or alkalis can be used. Examples of catalysts include formic acid, hydrochloric acid, nitric acid, acetic acid, aqueous ammonia, and tetramethylammonium hydroxide.

[0047] The silane coupling agent is not particularly limited and can be appropriately selected according to the desired resin properties. Preferred silane coupling agents have functional groups such as amino groups, carboxyl groups, phosphino groups, phosphine oxide groups, ammonium ions, vinyl groups, allyl groups, glycidyl groups, phenyl groups, acrylic groups, methacrylic groups, and thiol groups. Furthermore, silane coupling agents having not just one type of functional group but two or more types of functional groups may be used. Examples of silane coupling agents include trimethoxyvinylsilane, triethoxyvinylsilane, trimethoxy(4-vinylphenyl)silane, allyltriethoxysilane, allyltrimethoxysilane, triethoxy(3-glycidyloxypropyl)silane, 3-glycidyloxypropyltrimethoxysilane, [8-(glycidyloxy)-n-octyl]trimethoxysilane, KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.), (3-methacryloyloxypropyl)triethoxysilane, (3-methacryloyloxypropyl)trimethoxysilane, 3-(trimethoxysilyl)propyl acrylate, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0048] Furthermore, the alkoxysilane may include not only trialkoxysilane but also dialkoxysilane and monoalkoxysilane. It is preferable that the alkoxysilane consists of at least one of monoalkoxysilane, dialkoxysilane, and trialkoxysilane. Trialkoxysilane, dialkoxysilane, and monoalkoxysilane may have the same functional group or may have different functional groups. It is preferable that the alkoxysilane consists of two or more alkoxysilanes, each with different functional groups. By including dialkoxysilane and monoalkoxysilane, the degree of crosslinking of the silsesquioxane obtained by copolymerization can be controlled, thereby making it possible to control the viscosity of the resulting curable resin composition and adjust the viscosity according to the manufacturing process. The types and ratios of these alkoxysilanes are not particularly limited and can be appropriately selected according to the purpose. It is preferable that the alkoxysilane has one or more reactive substituents as functional groups, including vinyl group, acrylic group, methacrylic group, hydroxyl group, phenolic hydroxyl group, epoxy group, and glycidyl group.

[0049] The curable resin composition of the present invention is a mixture of a silsesquioxane polymer and a thermosetting resin. The thermosetting resin consists of a base polymer and a polymerization initiator, and may also contain a solvent, a polymerizable crosslinking agent, a photoacid generator, an antioxidant, a light scattering agent, and the like. The thermosetting resin is preferably an acrylic resin having (meth)acryloyl groups in its side chains or an acid-crosslinkable group-containing silicone resin. Suitable polymers include polymers derived from acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, copolymers combining several of these, polymers having glycidyl (meth)acrylate as a repeating unit, and polymers containing siloxane skeletons, urethane skeletons, silphenylene skeletons, norbornene skeletons, fluorene skeletons, and isocyanurate skeletons. The polymer used may be selected as appropriate according to the application. Examples include acrylic resins, alkyd resins, melamine resins, epoxy resins, silicone resins, polyvinyl alcohol, polyvinylpyrrolidone, polyamides, polyamide-imides, polyimide precursors and their esterification products, and reaction products of tetracarboxylic dianhydrides and diamines. These polymers also have polymerizable substituents introduced into them, and curing is possible when used in combination with polymerization initiators. Radical polymerizable substituents include vinyl groups, acrylic groups, methacrylic groups, and thiol groups, all of which can be suitably used. Cationic polymerizable substituents include hydroxyl groups, phenolic hydroxyl groups, epoxy groups, glycidyl groups, oxetanyl groups, and isocyanate groups, all of which can be suitably used.

[0050] Furthermore, the curable resin composition of the present invention may also preferably contain a polymerization initiator. The polymerization initiator may be a thermal polymerization initiator, and any of them can be suitably used in conjunction with the base polymer. Examples of thermal polymerization initiators include AIBN, BPO, TA-100, and IK-1 (manufactured by Sunapro Co., Ltd.). In addition, it may contain known thermal radical polymerization initiators or thermal cationic polymerization initiators, and is not particularly limited. The polymerization initiator content is preferably 0.1 to 10 parts by mass, and more preferably 0.2 to 5 parts by mass, per 100 parts by mass of polymer added.

[0051] The curable resin composition of the present invention may contain a solvent to improve its applicability. Organic solvents are preferred as solvents from the viewpoint of dispersibility with quantum dots, and examples include ketones, alkylene glycol ethers, alcohols, and aromatic compounds. Examples from the ketone group include acetone, methyl ethyl ketone, and cyclohexanone; and examples from the alkylene glycol ether group include methyl cellosolve (ethylene glycol monomethyl ether), butyl cellosolve (ethylene glycol monobutyl ether), methyl acetate cellosolve, ethyl acetate cellosolve, butyl acetate cellosolve, ethylene glycol monopropyl ether, ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, diethylene glycol ethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol acetate monomethyl ether, and diethylene glycol acetate methyl ether. From the group of alcohols, such as diethylene glycol acetate ethyl ether, diethylene glycol acetate propyl ether, diethylene glycol acetate isopropyl ether, diethylene glycol acetate butyl ether, diethylene glycol acetate tertiary butyl ether, triethylene glycol acetate methyl ether, triethylene glycol acetate ethyl ether, triethylene glycol acetate propyl ether, triethylene glycol acetate isopropyl ether, triethylene glycol acetate butyl ether, and triethylene glycol acetate tertiary butyl ether, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, 3-methyl-3-methoxybutanol, and from the group of aromatic compounds, benzene, toluene, and xylene can be suitably used.

[0052] Furthermore, the curable resin composition in the present invention may also contain polymerizable crosslinking agents, antioxidants, light scattering agents, and the like.

[0053] A curable resin composition containing the desired quantum dots can be obtained by mixing the above-mentioned thermosetting resin with a silsesquioxane polymer obtained by copolymerizing quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing quantum dots with alkoxysilane. The quantum dot content can be adjusted as appropriate according to the desired luminescence characteristics. Preferably, the quantum dot concentration is adjusted so that the excitation light absorption rate is 90% or higher. While the optimal concentration varies depending on the characteristics of the quantum dots, 10 parts by mass or more per 100 parts by mass of the curable resin composition is particularly preferred.

[0054] A wavelength conversion material for color filter applications can be obtained by coating a substrate with a curable resin composition containing quantum dots manufactured by the above method, and then exposing and developing it. The method for manufacturing the wavelength conversion material is not particularly limited and can be appropriately selected according to the required properties and process. For example, a wavelength conversion material can be obtained by coating a curable resin composition onto a transparent film or substrate material such as PET or polyimide and curing it. For coating transparent films, various methods can be used, including spraying, inkjet printing, spin coating, and bar coating.

[0055] The method for curing the curable resin composition is not particularly limited, but for example, it can be done by heating a film coated with the curable resin composition at 60°C for 2 hours, and then at 150°C for 4 hours. The method can also be modified as appropriate depending on the application. [Examples]

[0056] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited thereto. In this example, an InP / ZnSe / ZnS core-shell type quantum dot was used as the quantum dot material.

[0057] (Quantum dot core synthesis process) 0.23 g (0.9 mmol) of palmitic acid, 0.088 g (0.3 mmol) of indium acetate, and 10 mL of 1-octadecene were added to a flask. The mixture was heated and stirred under reduced pressure at 100°C for 1 hour while dissolving the starting materials. After that, nitrogen was purged into the flask, and tritrimethylsilylphosphine was mixed with trioctylphosphine to make a 0.2 M solution. Made 0.75 mL (0.15 mmol) of the solution was added and the temperature was raised to 300°C. The solution changed color from yellow to red, and it was confirmed that core particles were being formed.

[0058] (Quantum dot shell layer synthesis process) Next, 2.85 g (4.5 mmol) of zinc stearate and 15 mL of 1-octadecene were added to another flask, and the mixture was heated and stirred under reduced pressure at 100°C for 1 hour while dissolving to prepare a 0.3 M zinc stearate octadecene solution. 3.0 mL (0.9 mmol) of this solution was added to the reaction solution after core synthesis and cooled to 200°C. Next, 0.474 g (6 mmol) of selenium and 4 mL of trioctylphosphine were added to another flask and heated to 150°C to dissolve, preparing a 1.5 M selenium trioctylphosphine solution. Made The reaction solution after the core synthesis step, which had been cooled to 200°C, was heated to 320°C over 30 minutes, and 0.1 mL of selentrioctylphosphine solution was added in 0.1 mL increments for a total of 0.6 mL (0.9 mmol). The mixture was held at 320°C for 10 minutes and then cooled to room temperature. 0.44 g (2.2 mmol) of zinc acetate was added and dissolved by heating and stirring under reduced pressure at 100°C. The flask was purged again with nitrogen and heated to 230°C. 0.98 mL (4 mmol) of 1-dodecanethiol was added and the mixture was held for 1 hour. The resulting solution was cooled to room temperature to prepare a core-shell type quantum dot-containing solution consisting of InP / ZnSe / ZnS.

[0059] (Surface treatment of quantum dots) After the reaction was complete, the mixture was cooled to room temperature, ethanol was added to precipitate the reaction solution, and the supernatant was removed by centrifugation. The same purification was repeated, and the solution was dispersed in toluene. The toluene solution of quantum dots was placed in a nitrogen-purged flask. 0.24 mL (1.0 mmol) of (3-mercaptopropyl)triethoxysilane was added to this solution, and the mixture was stirred at room temperature for 24 hours.

[0060] (Silsesquioxane copolymerization process) In a nitrogen-purged flask, 10 mL of (3-methacryloyloxypropyl)trimethoxysilane, 20 mL of toluene, and 10 mL of methanol were mixed, and 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring at room temperature. After addition, the mixture was stirred at room temperature for 60 minutes, and then the reaction was continued for another 60 minutes under reflux at a solution temperature of 60°C. The system was then vacuumed at 60°C for 2 hours, and the solvent was removed by distillation. Silsesquioxane containing methacrylic groups was obtained in the flask.

[0061] (Copolymer of quantum dots and silsesquioxane) The obtained silsesquioxane and the surface-treated quantum dot solution were added to a nitrogen-purged flask to a solid content concentration of 20 parts by mass. Then, 20 mL of toluene and 10 mL of methanol were added and mixed. At room temperature, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring. After dropwise addition, the mixture was stirred at room temperature for 60 minutes, and then the reaction was continued for another 60 minutes under reflux at a solution temperature of 60°C. Subsequently, copolymer 1 of quantum dots and silsesquioxane was obtained by distilling off the solvent while flowing nitrogen through the system at 40°C.

[0062] (Copolymerization of quantum dots and alkoxysilanes 1) 7 mL of (3-methacryloyloxypropyl)trimethoxysilane, 3 mL of ethoxytrimethylsilane, and a surface-treated quantum dot solution were added to a nitrogen-purged flask to a total solid content of 20 parts by mass. Then, 20 mL of toluene and 10 mL of methanol were added and mixed. At room temperature, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring. After dropwise addition, the mixture was stirred at room temperature for 60 minutes, and then the reaction was continued for another 60 minutes under reflux at a solution temperature of 60°C. Subsequently, the solvent was removed by distillation at 40°C while flowing nitrogen through the system to obtain copolymer 2 of quantum dots and silsesquioxane.

[0063] (Copolymerization of quantum dots and alkoxysilanes 2) In a nitrogen-purged flask, 4 mL of (3-methacryloyloxypropyl)trimethoxysilane, 3 mL of phenyltrimethoxysilane, 3 mL of ethoxytrimethylsilane, and a surface-treated quantum dot solution were added to a total solid content of 20 parts by mass. Then, 20 mL of toluene and 10 mL of methanol were added and mixed. At room temperature, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring. After dropwise addition, the mixture was stirred at room temperature for 60 minutes, and then the reaction was continued for another 60 minutes under reflux at a solution temperature of 60°C. Subsequently, the solvent was removed by distillation at 40°C while flowing nitrogen through the system, yielding copolymer 3 of quantum dots and silsesquioxane.

[0064] (Example 1) Copolymer 1 of quantum dots and silsesquioxane and acrylic resin RA-4101 (root surface) industry The acrylic resin was weighed so that it contained 20 parts by mass of quantum dots in terms of non-volatile component ratio, and 1 part by mass of AIBN was weighed and mixed with 100 parts by mass of the acrylic resin non-volatile component.

[0065] (Example 2) Copolymer 2 of quantum dots and silsesquioxane and acrylic resin RA-4101 (root surface) industry The acrylic resin was weighed so that it contained 20 parts by mass of quantum dots in terms of non-volatile component ratio, and 1 part by mass of AIBN was weighed and mixed with 100 parts by mass of the acrylic resin non-volatile component.

[0066] (Example 3) Copolymer 3 of quantum dots and silsesquioxane and acrylic resin RA-4101 (root surface) industryThe acrylic resin was weighed so that it contained 20 parts by mass of quantum dots in terms of non-volatile component ratio, and 1 part by mass of AIBN was weighed and mixed with 100 parts by mass of the acrylic resin non-volatile component.

[0067] (Example 4) Copolymer 1 of quantum dots and silsesquioxane and epoxy-containing silicone resin (Shin-Etsu Chemical Co., Ltd., CAS No. 2253674-54-1) were weighed and mixed so that the non-volatile component ratio contained 20 parts by mass of quantum dots. For every 100 parts by mass of the non-volatile component of the silicone resin, 2 parts by mass of the thermal acid generator TA-100 and 20 parts by mass of the crosslinking agent THI-DE were weighed and mixed.

[0068] (Example 5) Copolymer 2 of quantum dots and silsesquioxane and epoxy-containing silicone resin (Shin-Etsu Chemical Co., Ltd., CAS No. 2253674-54-1) were weighed and mixed so that the non-volatile component ratio contained 20 parts by mass of quantum dots. For every 100 parts by mass of the non-volatile component of the silicone resin, 2 parts by mass of the thermal acid generator TA-100 and 20 parts by mass of the crosslinking agent THI-DE were weighed and mixed.

[0069] (Example 6) Copolymer 3 of quantum dots and silsesquioxane and epoxy-containing silicone resin (Shin-Etsu Chemical Co., Ltd., CAS No. 2253674-54-1) were weighed and mixed so that the quantum dots were present in a ratio of 20 parts by mass of nonvolatile components. For every 100 parts by mass of the nonvolatile components of the silicone resin, 2 parts by mass of the thermal acid generator TA-100 and 20 parts by mass of the crosslinking agent THI-DE were weighed and mixed.

[0070] (Comparative Example 1) Quantum dots with only surface treatment and acrylic resin RA-4101 (root surface) industry The acrylic resin was weighed so that it contained 20 parts by mass of quantum dots in terms of non-volatile component ratio, and 1 part by mass of AIBN was weighed and mixed with 100 parts by mass of the acrylic resin non-volatile component.

[0071] (Comparative Example 2) Quantum dots that had undergone only surface treatment and epoxy-containing silicone resin (Shin-Etsu Chemical Co., Ltd., CAS No. 2253674-54-1) were weighed and mixed so that the quantum dots comprised 20 parts by mass in terms of non-volatile component ratio. For every 100 parts by mass of the non-volatile component of the silicone resin, 2 parts by mass of the thermal acid generator TA-100 and 20 parts by mass of the crosslinking agent THI-DE were weighed and mixed.

[0072] Wavelength conversion materials were prepared using the quantum dot-containing curable resin compositions obtained in Examples 1-6 and Comparative Examples 1-2. The quantum dot-containing curable resin composition was applied to a glass substrate, and after removing the solvent, a 50 μm thick semiconductor nanoparticle resin layer was formed using a bar coater. The semiconductor nanoparticle resin layer was then cured by heating at 120°C for 5 minutes to produce the wavelength conversion material.

[0073] (Evaluation of variance) Aggregates in the cured resin film were examined using an optical microscope. Aggregates larger than 1 μm were marked with a ×, and those without aggregates or smaller than 1 μm were marked with a ○.

[0074] (Hardening evaluation) The curability of the resin-cured film was assessed by measuring the spectra before and after curing using a Fourier transform infrared spectrophotometer (JASCO Corporation FT / IR-4600). The curing rate was determined from the change in peak height attributed to the functional groups involved in curing. The curing rate was defined by (Equation 1), where A1 is the peak intensity before curing and A2 is the peak intensity after curing. (Formula 1) Curing rate (%)=(A1-A2) / A1×100 In Examples 1-3 and Comparative Example 1, the curing rate was calculated using an acrylic group as the functional group, while in Examples 4-6 and Comparative Example 2, an epoxy group was used.

[0075] (Evaluation of luminescence properties) For evaluating the luminescence properties of the wavelength conversion material, we used the Otsuka Electronics Co., Ltd. Quantum Efficiency Measurement System (QE-2100) to measure the emission wavelength, fluorescence half-width, and fluorescence emission efficiency (internal quantum efficiency) of quantum dots at an excitation wavelength of 450 nm.

[0076] (Reliability evaluation) The obtained patterns were processed at 85°C and 85% RH (relative humidity) for 250 hours, and the quantum yield after processing was measured to confirm the rate of decrease from the initial value and evaluate its reliability.

[0077] Table 1 shows the fluorescence emission efficiency values ​​after the fabrication of the wavelength conversion materials for the examples and comparative examples, as well as the fluorescence emission efficiency values ​​after reliability evaluation.

[0078] [Table 1]

[0079] As shown in Table 1, aggregation occurred in the comparative example, accompanied by a long-wavelength shift in emission wavelength and an increase in full width at half maximum. Furthermore, a decrease in quantum yield and degradation of emission intensity were observed in reliability tests.

[0080] On the other hand, no aggregates were observed in the examples, suggesting that changes in luminescence properties were suppressed. Furthermore, a comparison of reliability test results shows that the examples all exhibited improved stability compared to the comparative examples, indicating that changes over time were suppressed.

[0081] As described above, it has been confirmed that by using the curable resin composition of the present invention, wavelength conversion materials with stable and highly reliable luminescence properties can be obtained.

[0082] This specification includes the following embodiments: [1]: A curable resin composition comprising quantum dots, characterized in that the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane and a thermosetting resin. [2]: A curable resin composition comprising quantum dots, characterized in that the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots and an alkoxysilane, and a thermosetting resin. [3]: The curable resin composition according to [1] or [2] above, characterized in that the surface of the quantum dots is surface-modified with a silane coupling agent. [4]: The curable resin composition according to [2], characterized in that the alkoxysilane consists of two or more alkoxysilanes, each with a different functional group. [5]: The curable resin composition according to [2] or [4] above, characterized in that the alkoxysilane consists of at least one alkoxysilane selected from monoalkoxysilane, dialkoxysilane, and trialkoxysilane. [6]: The curable resin composition according to [3] above, characterized in that the silane coupling agent has one or more of the following: an amino group, a thiol group, a carboxyl group, a phosphin group, a phosphine oxide group, and an ammonium ion. [7]: The curable resin composition according to [1], characterized in that the silsesquioxane has one or more reactive substituents as functional groups, which include vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, and glycidyl groups. [8]: The curable resin composition according to [2] above, characterized in that the alkoxysilane has one or more reactive substituents as functional groups, which include vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, and glycidyl groups. [9]: The curable resin composition according to [1], [2], [3], [4], [5], [6], [7], or [8], characterized in that the thermosetting resin is an acrylic resin having (meth)acryloyl groups in its side chains.

[10] : The curable resin composition according to [1], [2], [3], [4], [5], [6], [7], or [8], characterized in that the thermosetting resin is an acid-crosslinkable group-containing silicone resin.

[0083] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. A curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane and a thermosetting resin, and the surface of the quantum dots is surface-modified with a silane coupling agent.

2. A curable resin composition containing quantum dots, wherein the curable resin composition is a mixture of a silsesquioxane polymer obtained by copolymerizing the quantum dots and an alkoxysilane, and a thermosetting resin, and the surface of the quantum dots is surface-modified with a silane coupling agent.

3. The curable resin composition according to claim 2, characterized in that the alkoxysilane consists of two or more alkoxysilanes, each with a different functional group.

4. The curable resin composition according to claim 2, characterized in that the alkoxysilane comprises at least one alkoxysilane selected from monoalkoxysilane, dialkoxysilane, and trialkoxysilane.

5. The curable resin composition according to claim 3, characterized in that the alkoxysilane comprises at least one alkoxysilane selected from monoalkoxysilane, dialkoxysilane, and trialkoxysilane.

6. The curable resin composition according to claim 1, characterized in that the silane coupling agent has one or more of the following: an amino group, a thiol group, a carboxyl group, a phosphin group, a phosphine oxide group, and an ammonium ion.

7. The curable resin composition according to claim 2, characterized in that the silane coupling agent has one or more of the following: an amino group, a thiol group, a carboxyl group, a phosphin group, a phosphine oxide group, and an ammonium ion.

8. The curable resin composition according to claim 1, characterized in that the silsesquioxane has one or more reactive substituents as functional groups, which include vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, and glycidyl groups.

9. The curable resin composition according to claim 2, characterized in that the alkoxysilane has one or more reactive substituents as functional groups, which include vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, and glycidyl groups.

10. The curable resin composition according to any one of claims 1 to 9, characterized in that the thermosetting resin is an acrylic resin having (meth)acryloyl groups in its side chains.

11. The curable resin composition according to any one of claims 1 to 9, characterized in that the thermosetting resin is an acid-crosslinkable group-containing silicone resin.

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