Ink composition, method for manufacturing the ink composition, and method for manufacturing a color filter

Abstract

The present invention is an ink composition containing quantum dots and characterized by containing a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane or a silsesquioxane polymer obtained by copolymerizing the quantum dots with alkoxysilane. Consequently, provided is an ink composition which contains quantum dots, can disperse the quantum dots in a high concentration without aggregating, and has high reliability.

Description

Technical Field

[0001] The present invention relates to an ink composition, a method for producing an ink composition, and a method for producing a color filter.

Background Art

[0002] Semiconductor crystal particles having a nanosize particle diameter are called quantum dots. Since excitons generated by light absorption are confined in a nanosize region, the energy levels of the semiconductor crystal particles become discrete, and their band gaps change depending on the particle diameter. Due to these effects, the fluorescence emission of quantum dots is high-intensity, high-efficiency, and sharp compared to general phosphors. In addition, it has the characteristic that the emission wavelength can be controlled due to the characteristic that the band gap changes depending on the particle diameter, and its application as a wavelength conversion material for solid lighting and displays is expected. 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). In addition, by using quantum dots as a color filter material, the quantum dots absorb blue monochromatic light from the backlight unit and emit red or green light, so that it functions as a color filter and a wavelength conversion material, and its application to pixel elements with high efficiency and excellent color reproducibility has also been proposed (Patent Document 2). A micro-LED display in which this backlight unit is replaced with a micro-size LED array has attracted attention. In a micro-LED display, it is required to form a color filter on a micro-size LED. In recent years, the size of LED arrays has been miniaturized, requiring finer patterning of quantum dots than ever before. Furthermore, for color filter applications, it is necessary to increase the light absorption capacity of the color filter to suppress leakage of the excitation light (blue monochromatic light). Increasing the light absorption capacity of the color filter requires increasing the quantum dot density. A lithography process using photosensitive materials has been proposed as a method for forming quantum dot color filters on LED arrays (Patent Document 3). However, photolithography methods result in significant raw material loss due to the waste of uncured material, and involve many manufacturing steps such as baking, exposure, and development. For this reason, inkjet methods have also been investigated in recent years. With inkjet methods, raw material loss is minimal, the manufacturing process is simple with only ejection and curing required, and it is competitive in terms of cost. [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] However, because inkjet printers eject ink from narrow nozzles, the nozzle diameter must be very small to form fine patterns of 100 μm or less, especially required for applications such as micro-LEDs. This imposes significant limitations on the ink's properties in order to ensure stable ejection and pattern reproducibility. For example, factors such as ink viscosity, ink evaporation rate, and the concentration of quantum dots (solid components in the ink) and the aggregation and sedimentation of quantum dots in the resin solution are all important. If these factors are not within an appropriate range for the equipment and ejection conditions, problems such as clogging of the nozzle and ink supply line can easily occur. Furthermore, continuous ejection can lead to changes and variations in ejection characteristics, causing unevenness in characteristics between pixels. Generally, polar resin materials such as acrylic resins and silicone resins are 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. Aggregation can cause blockages in inkjet nozzles and supply lines, posing a significant process challenge.

[0007] Furthermore, in inkjet printing, attempts are being made to achieve miniaturization by using smaller nozzle diameters for coating. However, smaller nozzles lead to problems such as clogging and unstable ejection. In addition, because quantum dots are hydrophobic, nonpolar solvents are used. However, commonly used nonpolar solvents such as toluene and hexane have low boiling points and evaporate easily, making nozzle clogging due to solvent evaporation at the nozzle tip more likely. This phenomenon becomes particularly pronounced at higher quantum dot concentrations. High ink viscosity can cause problems such as clogging in the nozzle and ink supply lines, and continuous ejection can lead to changes and variations in ejection characteristics, causing unevenness between pixels. Low viscosity ink is essential for stable pattern formation, but generally, increasing the content of curable resin and quantum dots in the ink composition increases the viscosity of the ink composition, which can cause problems during the manufacturing process.

[0008] Furthermore, since the quantum dots in the resin composition after pattern formation are located within the resin material, unlike in a solution environment, ligand desorption and other processes are more likely to occur, and deterioration of their luminescence properties over time also becomes a problem. To address these problems, various methods have been attempted, such as surface coating of quantum dots (Patent Document 4), encapsulation (Patent Document 5), and polyhedral oligomeric silsesquioxane ligands (Patent Document 6), in order 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 at high concentrations of 10% by mass or more of quantum dots, and stability.

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

[0010] The present invention has been made to achieve the above objective, and provides an ink composition containing quantum dots, characterized in that it contains a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots with alkoxysilane.

[0011] Such an ink composition allows for the dispersion of quantum dots at high concentrations without aggregation, providing a highly reliable ink composition containing quantum dots.

[0012] In this case, it is preferable that the ink composition is such that the surface of the quantum dots is surface-modified with a silane coupling agent.

[0013] According to such an ink composition, a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots and alkoxysilane can be easily formed, and the quantum dots can be dispersed at a high concentration without aggregation, thereby providing an ink composition containing highly reliable quantum dots.

[0014] At this time, it is preferable that the alkoxysilane is composed of two or more types of alkoxysilanes having different functional groups to form an ink composition.

[0015] According to such an ink composition, the crosslinking degree of the silsesquioxane polymer can be controlled, the viscosity of the ink composition can be controlled, the quantum dots can be dispersed at a high concentration without aggregation, and an ink composition containing highly reliable quantum dots can be provided. Also, the viscosity can be adjusted according to the manufacturing process.

[0016] At this time, it is preferable that the alkoxysilane is composed of at least two types of alkoxysilanes selected from trialkoxysilane, monoalkoxysilane, and dialkoxysilane, and the viscosity of the ink composition is 1500 mPa·s or less.

[0017] According to such an ink composition, the crosslinking degree of the silsesquioxane polymer can be controlled, the viscosity of the ink composition can be controlled, the quantum dots can be dispersed at a high concentration without aggregation, and an ink composition containing highly reliable quantum dots can be provided. Also, the viscosity can be adjusted according to the manufacturing process.

[0018] At this time, it is preferable that the silane coupling agent has at least one of an amino group, a thiol group, a carboxyl group, a phosphino group, a phosphine oxide group, and an ammonium ion to form an ink composition.

[0019] According to such an ink composition, a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots and alkoxysilane can be easily formed, and the quantum dots can be dispersed at a high concentration without aggregation, thereby providing an ink composition containing highly reliable quantum dots.

[0020] At this time, it is preferable that the silsesquioxane has, as a functional group, at least one reactive substituent selected from vinyl group, acrylic group, methacrylic group, hydroxyl group, phenolic hydroxyl group, epoxy group, glycidyl group, and thiol group in the ink composition.

[0021] According to such an ink composition, a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots and alkoxysilane can be easily formed, and the quantum dots can be dispersed at a high concentration without aggregation, thereby providing an ink composition containing highly reliable quantum dots.

[0022] At this time, it is preferable that the alkoxysilane has, as a functional group, at least one reactive substituent selected from vinyl group, acrylic group, methacrylic group, hydroxyl group, phenolic hydroxyl group, epoxy group, glycidyl group, and thiol group in the ink composition.

[0023] According to such an ink composition, a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots and alkoxysilane can be easily formed. The quantum dots can be dispersed at a high concentration without aggregation, thereby providing an ink composition containing highly reliable quantum dots.

[0024] Further, the present invention provides a method for manufacturing a color filter, which comprises ejecting the above-described ink composition onto a substrate by an inkjet method to form a color filter.

[0025] According to this method for manufacturing color filters, quantum dots can be dispersed at high concentrations without aggregation, and a highly reliable ink composition containing quantum dots can be smoothly ejected onto a substrate by an inkjet method without clogging the nozzles, thereby easily and accurately forming color filters.

[0026] Furthermore, the present invention provides a method for producing an ink composition, characterized by comprising the steps of: preparing quantum dots; preparing an alkoxysilane; and forming a copolymer consisting of the quantum dots and the silsesquioxane by connecting the alkoxysilane to the surface of the quantum dots.

[0027] According to this method for manufacturing ink compositions, quantum dots can be dispersed at high concentrations without aggregation, and highly reliable ink compositions containing quantum dots can be easily and reliably produced.

[0028] In this case, it is preferable that the step of preparing the quantum dots is a method for producing an ink composition comprising the steps of forming a core and forming a shell that covers the core.

[0029] According to this method for manufacturing ink compositions, quantum dots with a core-shell structure can be easily and reliably produced, and quantum dots can be dispersed at high concentrations without aggregation, thereby providing a highly reliable ink composition containing quantum dots.

[0030] In this case, it is preferable that the step of forming the copolymer is a method for producing an ink composition comprising the steps of surface-modifying the surface of the quantum dots with a silane coupling agent and connecting the silsesquioxane to the surface of the quantum dots via the silane coupling agent.

[0031] According to this method for producing the ink composition, a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots with alkoxysilane, can be easily formed, and the quantum dots can be dispersed at high concentrations without aggregation, thereby providing a highly reliable ink composition containing quantum dots. [Effects of the Invention]

[0032] To achieve the above objectives, the present invention allows for the dispersion of high-concentration quantum dots without aggregation by copolymerizing quantum dots with silsesquioxane, or by copolymerizing quantum dots with alkoxysilane to form a silsesquioxane polymer, and then curing the silsesquioxane polymer by a crosslinking reaction, thereby providing a highly reliable ink composition containing quantum dots. According to the ink composition of the present invention, quantum dots can be dispersed at high concentrations without aggregation, resulting in a highly reliable ink composition containing quantum dots. According to the method for producing the ink composition of the present invention, quantum dots can be dispersed at high concentrations without aggregation, making it possible to produce a highly reliable ink composition containing quantum dots. According to the method for manufacturing color filters of the present invention, quantum dots can be dispersed at high concentration without aggregation, and a highly reliable ink composition containing quantum dots can be smoothly ejected onto a substrate by an inkjet method without clogging the nozzles, thereby easily and accurately forming a color filter. [Modes for carrying out the invention]

[0033] The following describes embodiments of the present invention, but the present invention is not limited thereto. As described above, there was a challenge in obtaining an inkjet ink composition that could disperse quantum dots at high concentrations without aggregation, contained highly reliable quantum dots, and enabled stable ejection. Therefore, the inventors diligently conducted research to achieve these objectives. As a result, they conceived of an ink composition containing a silsesquioxane polymer obtained by copolymerizing quantum dots and silsesquioxane, or by copolymerizing quantum dots and alkoxysilane, and thus completed the present invention.

[0034] (Quantum dots) 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.

[0035] (Composition of quantum dots) 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.

[0036] (Quantum dot structure) Furthermore, the structure of the quantum dot may be a core-only structure or it may have a core-shell structure.

[0037] (Core material) 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.

[0038] (Shell material) 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.

[0039] (The shape of quantum dots) Quantum dots can be spherical, cubic, or rod-shaped. The shape of the quantum dots is not restricted and can be freely chosen.

[0040] (Average particle diameter of quantum dots) The particle size of the quantum dot can be appropriately selected to match the desired wavelength range. The average particle diameter of quantum dots should preferably be 20 nm or less. If the average particle diameter exceeds this, the quantum size effect will not be obtained, resulting in a significant decrease in luminescence efficiency and an inability to control the band gap due to particle size. 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 possible.

[0041] (Ligang) Ligands may be present on the surface of quantum dots, and from the viewpoint of dispersibility, the ligands preferably contain 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.

[0042] (Silane coupling agent) It is preferable to modify the quantum dot surface with a silane coupling agent. As a silane coupling agent, those having an amino group, thiol group, carboxyl group, phosphin group, phosphine oxide group, or ammonium ion are preferred. 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.

[0043] The ink composition according to the present invention contains a silsesquioxane polymer obtained by copolymerizing quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing quantum dots and alkoxysilane.

[0044] (Silsesquioxane polymer obtained by copolymerizing quantum dots with silsesquioxane) In one embodiment of the present invention, quantum dots surface-modified with a silane coupling agent are copolymerized with silsesquioxane. The copolymerization method is not particularly limited. For example, by mixing 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 allow the reaction to occur, the quantum dots and silsesquioxane can be copolymerized. There are no particular restrictions on the type of catalyst; acids or alkalis can be used. Examples of catalysts include formic acid, hydrochloric acid, nitric acid, acetic acid, maleic acid, aqueous ammonia, aqueous sodium hydroxide solution, and tetramethylammonium hydroxide. Furthermore, the structure of silsesquioxane is not particularly limited and can be selected as appropriate depending on the purpose, including cage structures, ladder structures, and random structures. Random structures are preferred from the viewpoint of dispersibility and uniformity of quantum dots. Furthermore, the functional groups contained in silsesquioxane are not limited and may be appropriately substituted depending on the purpose. Substituents that can perform polymerization or crosslinking reactions are particularly preferred from the viewpoint of curability. Examples of functional groups in silsesquioxane include vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, glycidyl groups, and thiol groups.

[0045] (Silsesquioxane polymer obtained by copolymerizing quantum dots and alkoxysilane) In another embodiment of the present invention, a silsesquioxane polymer is obtained by copolymerizing quantum dots surface-modified with a silane coupling agent with an alkoxysilane. The copolymerization method is not particularly limited. As a method for synthesizing silsesquioxane, the method described in Non-Patent Document 1 is known. For example, a silsesquioxane polymer can be obtained by mixing surface-modified quantum dots and alkoxysilane in a mixed solvent of toluene and ethanol, and then reacting them with a small amount of water and a catalyst. There are no particular restrictions on the type or amount of catalyst added, and acids or alkalis can be used. Examples of catalysts include formic acid, hydrochloric acid, nitric acid, acetic acid, aqueous ammonia, and tetramethylammonium hydroxide. The silane coupling agent is not particularly limited and can be appropriately selected according to the desired resin properties. Preferred silane coupling agents are those having vinyl, allyl, glycidyl, phenyl, acrylic, methacrylic, or thiol functional groups. Furthermore, alkoxylans 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. Such silane coupling agents are preferable because they exhibit high coordination to quantum dots and also have high affinity between silsesquioxane and quantum dots. Furthermore, this is preferable because it allows for control of the polarity of the quantum dots and silsesquioxane polymers, resulting in good compatibility of the ink composition with any solvent.

[0046] Furthermore, the alkoxysilane may include not only trialkoxysilane but also dialkoxysilane and monoalkoxysilane. Trialkoxysilane, dialkoxysilane, and monoalkoxysilane may have the same functional group or they may have different functional groups. By including dialkoxysilane or monoalkoxysilane, the degree of crosslinking of the silsesquioxane obtained by copolymerization can be controlled, thereby controlling the viscosity of the resulting resin composition and allowing viscosity adjustment according to the manufacturing process. For example, during silsesquioxane synthesis, the crosslinking reaction can be limited and viscosity reduced by mixing the precursor trialkoxysilane with monoalkoxysilane having a long-chain alkyl group or bulky substituent. Furthermore, by mixing trialkoxysilane with dialkoxysilane or monoalkoxysilane, the degree of crosslinking can be reduced, resulting in lower viscosity. The type and ratio of these alkoxysilanes are not particularly limited and can be appropriately selected according to the purpose. The viscosity of the ink composition is preferably 1500 mPa·s or less, and particularly preferably 1000 mPa·s or less. There is no particular lower limit to the viscosity, but it is, for example, 1 mPa·s or more. The viscosity of the ink composition is measured, for example, at 25°C using a rotational viscometer (Brookfield DV-I). Examples of functional groups for alkoxysilanes include one or more reactive substituents from among vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, glycidyl groups, and thiol groups.

[0047] The method for producing the ink composition according to the present invention comprises: step 1 of preparing quantum dots; step 2 of preparing an alkoxysilane; and step 3 of forming a copolymer consisting of the quantum dots and the silsesquioxane by connecting the alkoxysilane to the surface of the quantum dots. It is preferable that step 1 for preparing the quantum dot comprises step 1-1 for forming a core and step 1-2 for forming a shell that covers the core. Furthermore, it is preferable that step 3 for forming the copolymer comprises step 3-1 for surface modification of the quantum dot surface with a silane coupling agent, and step 3-2 for connecting the silsesquioxane to the quantum dot surface via the silane coupling agent.

[0048] The ink composition of the present invention comprises a copolymer of surface-treated quantum dots and silsesquioxane, a crosslinking agent and a polymerization initiator, and may also contain a solvent, antioxidant, light scattering agent, etc.

[0049] (Crosslinking agent) Preferably, the crosslinking agent has two or more functional groups that react with polymerizable substituents contained in the copolymer of quantum dots and silsesquioxane. The amount of crosslinking agent added is not particularly limited, nor are the combinations of these functional groups particularly limited; they can be appropriately selected according to the desired curing properties. Examples of radically polymerizable substituents include vinyl groups, acrylic groups, methacrylic groups, and thiol groups, all of which can be suitably used. Examples of 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. Examples of crosslinking agents include dipentaerythritol hexaacrylate, octavinylsilsesquioxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane, triallyl isocyanurate, trimethylolpropane triacrylate, and N,N'-methylenebis(acrylamide).

[0050] (Scatterer) As the scattering material, inorganic particles or organic particles can be appropriately selected depending on the purpose, and it is desirable to adjust the particle size and amount added to optimize the light extraction efficiency based on the wavelength of the light source used, the emission wavelength, and the structure of the wavelength conversion material. Examples of inorganic particles include silica, zirconia, alumina, barium titanate, and barium sulfate, while examples of organic particles include PMMA, polystyrene, and polycarbonate.

[0051] (Polymerization initiator) The ink composition of the present invention preferably contains a polymerization initiator. Polymerization initiators include thermal and photopolymerization initiators, and either can be suitably used depending on the polymerization method. Examples of photoradical polymerization initiators include the Irgacure® series, commercially available from BASF, such as Irgacure 290, Irgacure 651, Irgacure 754, Irgacure 184, Irgacure 2959, Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 819, and Irgacure 1173. Examples of products in the Darocure (registered trademark) series include TPO and Darocure 1173. In addition, the material may contain known thermal radical polymerization initiators or photocationic 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.

[0052] (solvent) The ink composition of the present invention may contain a solvent to improve its applicability. Organic solvents are preferred as solvents from the viewpoint of compatibility with quantum dots, and examples include ketones, alkylene glycol ethers, alcohols, and aromatic compounds. From the ketone group, acetone, methyl ethyl ketone, cyclohexanone, etc. From the alkylene glycol ether group, 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, diethylene glycol acetate From the group of alcohols, such as methyl ether, 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, triethylene glycol acetate tertiary butyl ether, etc., as well as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, 3-methyl-3-methoxybutanol, etc., and from the group of aromatic solvents, such as benzene, toluene, and xylene. In inkjet printing, a problem arises where the evaporation of the solvent at the nozzle tip causes solid components such as quantum dots to solidify, leading to nozzle tip blockage and unstable ejection. Therefore, solvents that do not easily volatilize, especially organic solvents with a boiling point of 100°C or higher, are preferred. Suitable solvents for this purpose include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethylene glycol, and propylene glycol.

[0053] (Quantum dot content) 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. The optimal concentration varies depending on the characteristics of the quantum dots, but 10% by weight or higher is particularly preferred.

[0054] The method for manufacturing a color filter according to the present invention is a method for forming a color filter by ejecting the ink composition according to the present invention onto a substrate using an inkjet method.

[0055] (Inkjet device, method, substrate) By applying an ink composition containing quantum dots manufactured by the above method onto a substrate using an inkjet device, a wavelength conversion material for color filter applications can be obtained. The inkjet printing method is not particularly limited; various methods such as piezo, bubble, and valve printing can be selected as appropriate according to the ink characteristics. Similarly, the structure of the inkjet device is not particularly limited; for example, it may have a single nozzle or multiple nozzles. The substrate can be selected appropriately depending on the purpose. Examples include silicon wafers, glass substrates, resin plates, and resin films. In addition, the substrate surface may be treated with a silane coupling agent or the like to improve the adhesion of the pattern.

[0056] (Curing of the ink composition) The ink composition according to the present invention can be a mixture of a silsesquioxane polymer and a curable resin. In this case, after the ink composition is dispensed onto the substrate, the resin layer is cured. If the resin is photocurable, the resin layer can be cured by UV light irradiation, and if the resin is thermosetting, the resin layer can be cured by heating the substrate together with the resin. The curing conditions are preferably adjusted according to the resin material and pattern shape. The thermosetting resin is preferably an acrylic resin having (meth)acryloyl groups in its side chains or a silicone resin containing acid-crosslinkable groups. 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, urethane, silphenylene, norbornene, fluorene, and isocyanurate skeletons. The polymer used may be selected as appropriate for 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. Furthermore, these polymers have polymerizable substituents introduced, enabling curing when used in combination with a polymerization initiator. Radical polymerizable substituents include vinyl groups, acrylic groups, methacrylic groups, and thiol groups, all of which can be suitably used. Examples of 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. [Examples]

[0057] The present invention will be described more specifically below with reference to 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.

[0058] (Step 1: Preparing quantum dots) (Core formation process 1-1: 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, and degassed for 1 hour while dissolving the raw materials. Subsequently, nitrogen was purged into the flask, and 0.75 mL (0.15 mmol) of a solution prepared by mixing tritrimethylsilylphosphine with trioctylphosphine to a 0.2 M solution was added. The temperature was then raised to 300°C, and it was confirmed that the solution changed color from yellow to red, indicating the formation of core particles.

[0059] (Process 1-2 for forming the shell covering the core: 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 the mixture was 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 selentrioctylphosphine solution. The reaction solution after the core synthesis step, which had been cooled to 200°C, was then heated to 320°C over 30 minutes, and the 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 to 100°C. The flask was then purged with nitrogen again and the temperature was raised to 230°C. 0.98 mL (4 mmol) of 1-dodecanethiol was added and the mixture was held for 1 hour. The obtained solution was cooled to room temperature to prepare a core-shell type quantum dot-containing solution consisting of InP / ZnSe / ZnS.

[0060] (Step 2: Preparing the alkoxysilane) 6 mL of (3-mercaptopropyl)triethoxysilane, 1 mL of trimethoxy(3,3,3-trifluoropropyl)silane, 3 mL of phenyltrimethoxysilane, and 6 mL of (3-mercaptopropyl)triethoxysilane and 2 mL of phenyltrimethoxysilane, 2 mL of ethoxytrimethylsilane, and 6 mL of (3-methacryloyloxypropyl)trimethoxysilane and 2 mL of phenyltrimethoxysilane, 2 mL of ethoxytrimethylsilane, and 7 mL of 3-aminopropyltrimethoxysilane, 1 mL of dodecyltrimethoxysilane and 2 mL of ethoxytrimethylsilane, and 10 mL of (3-methacryloyloxypropyl)trimethoxysilane were prepared.

[0061] (Step 3: Using an alkoxysilane as a silsesquioxane attached to the surface of a quantum dot, a copolymer consisting of the quantum dot and the silsesquioxane is formed.) (Step 3-1: 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 process was repeated, and the mixture was dispersed in toluene. A 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 mixture and stirred at room temperature for 24 hours.

[0062] (Step 3-2(1) to connect silsesquioxane to the surface of quantum dots via a silane coupling agent: Copolymerization of quantum dots and silsesquioxane 1) In a nitrogen-purged flask, 6 mL of (3-mercaptopropyl)triethoxysilane, 1 mL of trimethoxy(3,3,3-trifluoropropyl)silane, 3 mL of phenyltrimethoxysilane, 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 mixed, and 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring at room temperature. 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 in the system was removed by vacuum evacuation at 60°C for 180 minutes to obtain a copolymer (1) of quantum dots and silsesquioxane.

[0063] (Step 3-2(2) to connect silsesquioxane to the surface of quantum dots via a silane coupling agent: Copolymerization of quantum dots and silsesquioxane 2) In a nitrogen-purged flask, 6 mL of (3-mercaptopropyl)triethoxysilane, 2 mL of phenyltrimethoxysilane, 2 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. Then, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring at room temperature. 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 a copolymer (2) of quantum dots and silsesquioxane.

[0064] (Step 3-2(3) to connect silsesquioxane to the surface of quantum dots via a silane coupling agent: Copolymerization of quantum dots and alkylsilane 3) In a nitrogen-purged flask, 6 mL of (3-methacryloyloxypropyl)trimethoxysilane, 2 mL of phenyltrimethoxysilane, 2 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. Then, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring at room temperature. 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 while flowing nitrogen through the system at 40°C to obtain a copolymer of quantum dots and silsesquioxane (3).

[0065] (Step 3-2(4) of connecting silsesquioxane to the surface of quantum dots via a silane coupling agent: Copolymerization of quantum dots and alkylsilane 4) 7 mL of 3-aminopropyltrimethoxysilane, 1 mL of dodecyltrimethoxysilane, 2 mL of ethoxytrimethylsilane, and a surface-treated quantum dot solution were added to a nitrogen-purged flask to a solid content concentration of 20% by mass. Then, 20 mL of toluene and 10 mL of methanol were added and mixed. Then, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring at room temperature. 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 while flowing nitrogen through the system at 40°C to obtain a copolymer of quantum dots and silsesquioxane (4).

[0066] (Step 3-2(5) to connect silsesquioxane to the surface of quantum dots via a silane coupling agent: Copolymerization of quantum dots and alkylsilane 5) In a nitrogen-purged flask, 10 mL of (3-methacryloyloxypropyl)trimethoxysilane 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. Then, 4.0 mL of 1.0 N hydrochloric acid was added dropwise in small amounts while stirring at room temperature. 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 while flowing nitrogen through the system at 40°C to obtain a copolymer of quantum dots and silsesquioxane (5).

[0067] (Synthesis of silsesquioxane crosslinking agent) In a nitrogen-purged flask, 10 mL of trimethoxyvinylsilane, 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 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 system was vacuum-assisted at 60°C for 2 hours to remove the solvent. A silsesquioxane containing a vinyl group was obtained in the flask (crosslinking agent (1)).

[0068] 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 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 system was vacuum-assisted at 60°C for 2 hours to remove the solvent. A silsesquioxane having a methacrylic group was obtained in the flask (crosslinking agent (2)).

[0069] In a nitrogen-purged flask, 10 mL of (3-glycidyloxypropyl)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 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 system was vacuum-assisted at 60°C for 2 hours to remove the solvent. A silsesquioxane having a glycidyl group was obtained in the flask (crosslinking agent (3)).

[0070] (Example 1) A quantum dot-silsesquioxane copolymer (1) was weighed so that it contained 20 wt% quantum dots in terms of non-volatile content, and octabinylsilsesquioxane was added as a crosslinking agent so that the molar ratio of mercapto groups in the copolymer to vinyl groups in the crosslinking agent was 1:1. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 1429 mPa·s (measured at 25°C).

[0071] (Example 2) A quantum dot-silsesquioxane copolymer (1) was weighed so that it contained 20 wt% quantum dots in terms of non-volatile content, and a crosslinking agent (1) was added as a crosslinking agent so that the molar ratio of mercapto groups in the copolymer to vinyl groups in the crosslinking agent was 1:1. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 1047 mPa·s (measured at 25°C).

[0072] (Example 3) A quantum dot-silsesquioxane copolymer (1) was weighed so that it contained 20 wt% quantum dots in terms of non-volatile content, and a crosslinking agent (2) was added as a crosslinking agent so that the molar ratio of mercapto groups in the copolymer to methacrylic groups in the crosslinking agent was 1:1. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 896 mPa·s (measured at 25°C).

[0073] (Example 4) The quantum dot-silsesquioxane copolymer (2) was weighed so that it contained 20 wt% quantum dots in terms of non-volatile content, and the crosslinking agent (1) was added as a crosslinking agent so that the molar ratio of mercapto groups in the copolymer to vinyl groups in the crosslinking agent was 1:1. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 788 mPa·s (measured at 25°C).

[0074] (Example 5) The quantum dot-silsesquioxane copolymer (2) was weighed so that it contained 20 wt% quantum dots in terms of non-volatile content, and the crosslinking agent (2) was added as a crosslinking agent so that the molar ratio of mercapto groups in the copolymer to vinyl groups in the crosslinking agent was 1:1. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 1024 mPa·s (measured at 25°C).

[0075] (Example 6) The quantum dot-silsesquioxane copolymer (3) was weighed so that it contained 20 wt% quantum dots in terms of non-volatile content, and the crosslinking agent (2) was added as a crosslinking agent so that the ratio of methacrylic groups in the copolymer to methacrylic groups in the crosslinking agent was 1:1 in molar ratio. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 652 mPa·s (measured at 25°C).

[0076] (Example 7) The quantum dot-silsesquioxane copolymer (4) was weighed out so that it contained 20 wt% quantum dots in terms of non-volatile content, and the crosslinking agent (3) was added as a crosslinking agent so that the ratio of amino groups in the copolymer to epoxy groups in the crosslinking agent was 1:1 in molar ratio. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 795 mPa·s (measured at 25°C).

[0077] (Comparative Example 1) Quantum dots that had undergone only surface treatment were weighed so that they contained 20 wt% of non-volatile content quantum dots, and crosslinking agent (1) was added as a crosslinking agent so that the ratio of mercapto groups to vinyl groups of the crosslinking agent in the surface-treated QD solution was 1:1 in molar ratio. Furthermore, 1 part by mass of Irgacure 1173 was weighed and mixed with 100 parts by mass of the non-volatile content of this mixture. Furthermore, propylene glycol monomethyl ether acetate was added as a solvent to obtain an ink composition with a solid content concentration of 50%. The viscosity of this ink composition was measured using a rotational viscometer and found to be 1393 mPa·s (measured at 25°C).

[0078] (Comparative Example 2) The solvent in Comparative Example 1 was changed to toluene to obtain the ink composition. The viscosity of this ink composition was measured using a rotational viscometer and found to be 1411 mPa·s (measured at 25°C).

[0079] Each of the ink compositions obtained in Examples 1-7 and Comparative Examples 1-2 was ejected onto a glass substrate at a 150 μm pitch using an inkjet device (LaboJet-600Bio, manufactured by MicroJet Corporation). The substrate after extrusion is subjected to atmospheric pressure at a wavelength of 365 nm and an output of 500 mW / cm². 2 It was cured by irradiating it with light. When the pattern remaining on the substrate was measured using a laser microscope (Olympus Corporation OLS-4100), it was confirmed that a dot-like pattern with an average thickness of 5 μm and a pattern size of 50 μm had been formed.

[0080] (Discharge stability) We tested the process by dispensing 10 patterns in a row in 5 consecutive rows. We evaluated any instances where nozzle or supply line clogging or ink dispensing failures occurred during this continuous operation, resulting in unstable dispensing, by marking them as "X". (Evaluation of variance) The aggregates in the pattern were confirmed using an electron microscope. Samples with aggregates larger than 1 μm were marked with ×, while samples without aggregates or with aggregates smaller than 1 μm were marked with ○.

[0081] (Pattern assessment) The formed island patterns were observed, and any defects such as uneven size and shape, missing patterns, or misaligned patterns were evaluated as "X".

[0082] (Evaluation of the luminescence properties of the formed pattern) Using a LabRAM Time Evolution manufactured by Horiba Techno Service Co., Ltd., the patterned samples prepared in the above examples and comparative examples were irradiated with 457 nm laser light (0.03 mW), and the light-converted island pattern region was measured. The emission intensity, emission wavelength, and full width at half maximum of the light-converted light were then measured.

[0083] (Reliability evaluation) The obtained patterns were treated at 85°C and 85% RH (relative humidity) for 250 hours, and the fluorescence emission efficiency after treatment was measured. The rate of decrease from the initial value was confirmed, and the reliability was evaluated.

[0084] Tables 1 and 2 show the evaluation results for the examples and comparative examples.

[0085] [Table 1]

[0086] [Table 2]

[0087] The results in Tables 1 and 2 show that in the comparative example, the nozzle became clogged due to viscosity and aggregation, resulting in unstable ink discharge, and consequently, pattern defects were also observed.

[0088] On the other hand, the example demonstrated stable discharge, no pattern defects, and good patterning properties. Furthermore, a comparison of the reliability test results shows that all of the examples exhibit improved stability compared to the comparative example, indicating that changes over time are suppressed.

[0089] As described above, it has been confirmed that by using the ink composition of the present invention, a wavelength conversion material with stable and highly reliable luminescence properties can be obtained.

[0090] This specification includes the following embodiments: [1]: An ink composition comprising quantum dots, characterized in that it comprises a silsesquioxane polymer obtained by copolymerizing the quantum dots with silsesquioxane, or a silsesquioxane polymer obtained by copolymerizing the quantum dots with alkoxysilane. [2]: The ink composition according to [1], characterized in that the surface of the quantum dots is surface-modified with a silane coupling agent. [3]: The ink composition according to [1] or [2] above, characterized in that the alkoxysilane consists of two or more alkoxysilanes, each having a different functional group. [4]: The ink composition according to [1], [2], or [3], characterized in that the alkoxysilane consists of at least two types of alkoxysilanes selected from trialkoxysilane, monoalkoxysilane, and dialkoxysilane, and the viscosity of the ink composition is 1500 mPa·s or less. [5]: The ink composition according to [2] 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, or an ammonium ion. [6]: Any of the ink compositions described in [1] to [5] above, characterized in that the silsesquioxane has one or more reactive substituents as functional groups, which include a vinyl group, an acrylic group, a methacrylic group, a hydroxyl group, a phenolic hydroxyl group, an epoxy group, a glycidyl group, and a thiol group. [7]: Any of the ink compositions described in [1] to [6] above, characterized in that the alkoxysilane has one or more reactive substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, epoxy, glycidyl, and thiol groups as functional groups. [8]: A method for manufacturing a color filter, characterized by ejecting any of the ink compositions described in [1] to [7] above onto a substrate by an inkjet method to form a color filter. [9]: A method for producing an ink composition, comprising the steps of: preparing quantum dots; preparing an alkoxysilane; and forming a copolymer consisting of the quantum dots and the silsesquioxane by connecting the alkoxysilane to the surface of the quantum dots.

[10] : A method for producing the ink composition according to [9], characterized in that the step of preparing the quantum dots comprises the steps of forming a core and forming a shell that covers the core.

[11] : A method for producing the ink composition according to [9] or

[10] , characterized in that the step of forming the copolymer comprises the step of surface modifying the surface of the quantum dot with a silane coupling agent, and the step of connecting the silsesquioxane to the surface of the quantum dot via the silane coupling agent.

[0091] 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. An ink composition containing quantum dots, characterized in that it contains a silsesquioxane polymer obtained by copolymerizing quantum dots with alkoxysilanes, which are reaction products of two or more alkoxysilanes, each having different functional groups.

2. The ink composition according to claim 1, characterized in that the surface of the quantum dot is surface-modified with a silane coupling agent.

3. The ink composition according to claim 1, characterized in that the alkoxysilane consists of at least two types of alkoxysilanes selected from trialkoxysilane, monoalkoxysilane, and dialkoxysilane, and the viscosity of the ink composition is 1500 mPa·s or less.

4. The ink 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, or an ammonium ion.

5. The ink composition according to claim 1, characterized in that the silsesquioxane has one or more reactive substituents as functional groups, selected from vinyl groups, acrylic groups, methacrylic groups, hydroxyl groups, phenolic hydroxyl groups, epoxy groups, glycidyl groups, and thiol groups.

6. The ink composition according to claim 1, characterized in that the alkoxysilane has one or more reactive substituents selected from a vinyl group, an acrylic group, a methacrylic group, a hydroxyl group, a phenolic hydroxyl group, an epoxy group, a glycidyl group, and a thiol group as functional groups.

7. A method for manufacturing a color filter, characterized by dispensing an ink composition according to any one of claims 1 to 6 onto a substrate by an inkjet method to form a color filter.

8. The process of preparing quantum dots, The process involves preparing two or more alkoxysilanes, each with a different functional group, A method for producing an ink composition, comprising the step of forming a silsesquioxane polymer by reacting the quantum dots with the alkoxysilane.

9. The process of preparing the aforementioned quantum dots is as follows: The process of forming the core, A method for producing an ink composition according to claim 8, comprising the step of forming a shell that covers the core.

10. The step of forming the silsesquioxane polymer is A step of surface-modifying the surface of the quantum dot with a silane coupling agent, A method for producing an ink composition according to claim 8, comprising the step of connecting the silsesquioxane to the surface of the quantum dot via the silane coupling agent.

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