Composition containing quantum dots, method for producing same, and wavelength conversion member

Abstract

The present invention is a quantum dot-containing composition which contains quantum dots that emit fluorescence in response to excitation light, and which is characterized in that the quantum dot-containing composition is a mixture of the quantum dots and a polymerizable polymer composition, and the surface of each quantum dot contains a surface coating layer having a siloxane bond. The content of free thiol groups contained in the surface coating layer is 4.0 mmol or less per 1 g of the quantum dots. As a result, provided are: a patterned quantum dot-containing composition which maintains quantum dot characteristics while improving stability and suppressing dark reactions such as thickening and residue generation; a method for producing the same; and a wavelength conversion member.

Description

Technical Field

[0001] The present invention relates to a quantum dot composition, a method for manufacturing the same, and a wavelength conversion component. Background Art

[0002] In a semiconductor nanoparticle single crystal, when the crystal size is equal to or smaller than the exciton Bohr radius, a strong quantum confinement effect occurs, and the energy levels become discrete. The energy levels depend on the crystal size, and the light absorption wavelength and light emission wavelength can be adjusted by the crystal size. In addition, due to the quantum confinement effect, the light emission efficiency caused by exciton recombination in the semiconductor nanoparticle single crystal is very high. Further, since this light emission is essentially an emission line, if a uniform particle size distribution can be achieved, it will attract attention because it can achieve high-brightness and narrow-band light emission. This phenomenon caused by the strong quantum confinement effect in nanoparticles is called the quantum size effect, and using this property, semiconductor nanocrystals are being studied as quantum dots for a wide range of applications.

[0003] As an application of quantum dots, their use as phosphor materials for displays is being studied. If narrow-band and high-efficiency light emission can be achieved, colors that cannot be reproduced by existing technologies can be exhibited, and thus they are attracting much attention as next-generation display materials.

[0004] Currently, as a display using quantum dots, there is a quantum dot liquid crystal display, which has entered commercialization. An attempt is made to convert the color of light by allowing light emitted from white light or blue LED backlight to pass through a wavelength conversion component containing quantum dots into green or red. The surface of quantum dots is active, and due to moisture and oxygen in the air, etc., their quantum yield gradually decreases. Therefore, improving the stability of the wavelength conversion component containing quantum dots is a research matter that must be addressed.

[0005] Various studies have been conducted on the stability of the wavelength conversion component containing quantum dots. One example is gas barrier sealing. By dispersing quantum dots in an amphiphilic polymer or a compatible polymer to form an inner layer, and then dispersing it in another resin layer with low gas permeability, the stability is improved. Patent Document 1 discloses a method of dispersing in a hydrophilic polymer, dispersing quantum dots (QD) in a hydrophobic resin layer to form polymer beads, and surface-modifying the polymer beads so that they can be dispersed in a hydrophilic polymer. Hydrophilic polymers tend to have better gas barrier properties than hydrophobic polymers, so quantum dots (QD) are dispersed in such a bilayer or multilayer structure. However, its gas barrier property is not sufficient for applications such as liquid crystal display units where high-temperature and high-humidity environments may occur. Therefore, a method of sandwiching a QD film between gas barrier films to eliminate the effects of oxygen and water vapor is adopted.

[0006] Various studies have also been conducted on the preparation method of polymer beads. Patent Document 2 discloses a method of preparing polymer beads containing QDs using a polysiloxane having an amino group and a polymerizable functional group, and then mixing, emulsifying, and further curing another polymer having a polymerizable functional group. In this method, the adhesion to QDs is increased by introducing a polymer containing a ligand coordinated to the QD surface, so that the concentration of QDs contained in the polymer beads can be increased, thereby improving stability. However, this method still cannot provide sufficient stability, so it is installed by sandwiching between barrier films.

[0007] Using barrier films not only increases costs but also inevitably increases the thickness. Currently, in the pursuit of thinner liquid crystal displays, the thickness of the wavelength conversion component needs to be reduced, so this has led to a need to improve stability without using barrier films. In addition, when considering use in color filters, patterning is required, and it is not practical to provide a protective layer such as a barrier film, so the stability of the quantum dots themselves is required.

[0008] Patent Document 3 discloses research on improving heat resistance and moisture resistance without using barrier films. In this method, a multilayer resin composition having the polymer bead structure of the above Patent Document 1 is further subjected to a silicon nitride coating treatment to improve stability. However, this method has the following problems: when the silicon nitride coating is irradiated with short ultraviolet light (170 nm) for photocuring, the quantum yield will decrease.

[0009] In addition, Patent Document 4 discloses another attempt. In this method, a ligand is coordinated with the quantum dots, and reactive substituents such as vinyl and methacryloyl are introduced into the ligand. Next, a Si-H-containing silicone resin and a curing agent are mixed together, and then spin-coated and heated to cure, thereby preparing a film with improved heat resistance and moisture resistance. However, the compatibility between the Si-H-containing silicone resin used and the quantum dots is low, and attempting to disperse them at a high concentration will cause aggregation. Therefore, the compatibility must be improved by ligand treatment; however, if the balance between hydrophobic groups and hydrophilic groups changes when the ligand is coordinated, there is a problem that aggregation easily occurs, resulting in a decrease in the quantum yield.

[0010] In addition, when applying them to color filters, it is very important to form quantum dot surface states suitable for patterning methods. Currently, in color filters, photolithography is put into practical use. A photosensitive resin composition containing pigments is coated on a glass substrate. After drying the solvent, the substrate is irradiated with ultraviolet light through a mask, and then the uncured part is removed by alkaline development to form a color pattern. Then, this process is repeated to form blue, red, and green patterns. There are also many problems with photolithography, including waste of the uncured part, resulting in a large loss of raw materials, complex processes, and the use of expensive equipment. Therefore, in recent years, the inkjet method has also been considered. The inkjet method is competitive in terms of cost because there is no loss of raw materials, and larger sizes and areas can be prepared without introducing expensive equipment. However, the technology for manufacturing micro nozzles is difficult, and problems such as clogging and unstable ejection occur as the nozzles become smaller. Therefore, in order to achieve miniaturization, mature photolithography technology and cost-competitive inkjet technology are being studied.

[0011] On the other hand, there are problems in preparing a resin composition containing quantum dots with high concentration and high dispersibility, whether it is photolithography or inkjet. Except for a part of the resin composition, it is dispersed in polar solvents such as PGMEA and PGME. Quantum dots are inherently hydrophobic and difficult to disperse in these solvents and resin materials, and tend to aggregate. Therefore, it is very difficult to prepare a photosensitive resin composition containing quantum dots with high concentration and high dispersibility. As a countermeasure, adding a dispersant has been considered, but there are problems such as a decrease in the quantum dot content and a change in the properties of the cured resin. In addition, generally, heating is used to volatilize the solvent, but this causes dark reaction problems such as poor curing, thickening, and residue generation due to the influence of impurities contained in the quantum dots. Prior Art Documents Patent Documents

[0012] Patent Document 1: US Patent No. 9,708,532 Gazette Patent Document 2: Japanese Unexamined Patent Application Publication No. 2016-111292 Patent Document 3: Japanese Patent Application Laid-Open No. 2019-536653 Patent Document 4: US Patent Gazette No. 20190322926 Summary of the Invention

Problems to be Solved by the Invention

[0013] In view of the above problems, the present invention provides a patternable quantum dot-containing composition, a method for manufacturing the same, and a wavelength conversion component. While maintaining the characteristics of the quantum dots, the composition improves stability and suppresses dark reactions such as thickening and residue generation.

Means for Solving the Problems

[0014] In order to solve the above problems, the present invention provides a quantum dot composition, which contains quantum dots that emit fluorescence in response to excitation light. The quantum dot composition is a mixture of the quantum dots and a polymerizable polymer composition. The surface of the quantum dots contains a surface coating layer having a siloxane bond, and the content of free thiol groups contained in the surface coating layer is 4.0 mmol or less per 1 g of the quantum dots.

[0015] Such a quantum dot composition improves stability while maintaining the characteristics of the quantum dots, inhibits dark reactions such as thickening and residue generation, and thus forms a patternable quantum dot composition.

[0016] At this time, preferably, the content of the free thiol groups contained in the surface coating layer is 3.0 mmol or less per 1 g of the quantum dots.

[0017] Such a quantum dot composition is more likely to prevent poor curing, and thus is preferred.

[0018] At this time, preferably, the content of the free thiol groups contained in the surface coating layer is 1.0 mmol or less per 1 g of the quantum dots.

[0019] Such a quantum dot composition can further inhibit dark reactions, and thus is preferred.

[0020] At this time, preferably, the surface coating layer has one or more reactive substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups.

[0021] Such reactive substituents can prevent aggregation of the quantum dots, and thus are preferred.

[0022] At this time, preferably, the polymerizable polymer contained in the polymerizable polymer composition has one or more polymerizable substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups.

[0023] Such groups are suitable as polymerizable substituents.

[0024] The present invention also provides a wavelength conversion component, which is a cured product of the above-described quantum dot composition.

[0025] Such a wavelength conversion component maintains the characteristics of the quantum dots, improves stability, and inhibits dark reactions such as thickening and residue generation, thereby forming a patternable wavelength conversion component.

[0026] The present invention also provides a method for manufacturing the above-described quantum dot composition, the quantum dot composition contains quantum dots that emit fluorescence in response to excitation light, and the manufacturing method includes: Ligand exchange step: A solution in which the quantum dots are dispersed is mixed with a ligand having a substituent that forms a siloxane bond, and the ligand is coordinated to the outermost surface of the quantum dots; Surface coating layer formation step: After the ligand exchange step, a compound that reacts with the substituent that forms the siloxane bond to generate polysiloxane reacts with the substituent that forms the siloxane bond, thereby forming a surface coating layer; Purification step: After the surface coating layer formation step, through purification, the content of free thiol groups contained in the surface coating layer is 4.0 mmol or less per 1 g of the quantum dots; Polymerizable polymer composition mixing step: After the purification step, the quantum dots coated with the surface coating layer are mixed with the polymerizable polymer composition.

[0027] Such a method for manufacturing a quantum dot-containing composition can improve stability while maintaining the characteristics of the quantum dots, and can suppress side reactions such as thickening and residue generation, thereby enabling the production of a patternable quantum dot-containing composition.

Effects of the Invention

[0028] As a result of repeated in-depth research on the above problems, it was found that forming a surface coating layer containing siloxane can deactivate it and improve its stability. In addition, by suppressing the content of free thiol groups, side reactions with the polymerizable polymer composition are suppressed, whereby a quantum dot-containing composition that does not inhibit curing or generate residues even when added at a high concentration and cures can be prepared. As a result, in a reliability test at 85°C and 85% RH without a barrier film, the decrease rate of the internal quantum efficiency after 250 hours of treatment can be suppressed within 10%, achieving stabilization. And it is possible to suppress side reactions with the polymerizable polymer composition, and a quantum dot-containing composition with excellent patterning properties and curability can be achieved. Detailed Embodiments

[0029] As described above, it is necessary to develop a patternable quantum dot-containing composition, a method for manufacturing the same, and a wavelength conversion component that improve stability and suppress side reactions such as thickening and residue generation while maintaining the characteristics of the quantum dots.

[0030] The inventors of the present invention conducted repeated research on the above problems, and as a result, found that by making the content of free thiol groups per 1 g of quantum dots 4.0 mmol or less, the above problems can be solved, and thus the present invention was completed.

[0031] That is, the present invention relates to a quantum dot composition containing quantum dots that emit fluorescence in response to excitation light. The quantum dot composition is a mixture of the quantum dots and a polymerizable polymer composition. The surface of the quantum dots has a surface coating layer having a siloxane bond, and the content of free thiol groups contained in the surface coating layer is 4.0 mmol or less per 1 g of the quantum dots.

[0032] The present invention will be described in detail below, but the present invention is not limited thereto.

[0033] (Quantum dot composition) The quantum dot composition of the present invention is a quantum dot composition containing quantum dots that emit fluorescence in response to excitation light. The quantum dot composition is a mixture of the quantum dots and a polymerizable polymer composition. The surface of the quantum dots has a surface coating layer having a siloxane bond, and the content of free thiol groups contained in the surface coating layer is 4.0 mmol or less per 1 g of the quantum dots. That is, a surface coating layer is formed on the surface of the quantum dots to obtain composite particles having substituents capable of undergoing polycondensation reaction with the polymerizable polymer composition, or polymerizable substituents are introduced into the ligand of the skeletal structure substituents of the polymerizable polymer composition, and mixtures thereof.

[0034] (Quantum dots) The quantum dots in the present invention are not particularly limited as long as they can emit fluorescence by excitation light and can be used in any form. The quantum dots are mainly nanoparticles with a size of 10 nm or less, but can also be nanowires, nanorods, nanotubes, nanocubes, etc., and any shape is applicable.

[0035] The quantum dots used in the present invention can be made of any suitable material, for example, semiconductor materials selected from groups II-VI, III-V, IV, IV-VI, I-III-VI, II-IV-V, their mixed crystals or alloys, or compounds having a perovskite structure.

[0036] Specific examples of the compound include, but are not limited to, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, Si, Ge, Sn, Pb, PbS, PbSe, PbTe, SnS, SnSe, SnTe, AgGaS2, AgInS2, AgGaSe2, AgInSe2, CuGaS2, CuGaSe2, CuInS2, CuInSe2, ZnSiP2, ZnGeP2, CdSiP2, CdGeP2, CsPbCl3, CsPbBr3, CsPbI3, CsSnCl3, CsSnBr3, and CsSnI3.

[0037] In addition, the quantum dots used in the present invention can have a core-shell structure. The shell material capable of forming the core-shell structure is not particularly limited, but preferably a material having a larger bandgap and a lower lattice mismatch relative to the core material, and can be arbitrarily combined with the core material. Specific shell materials include, but are not limited to, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, BeS, BeSe, BeTe, MgS, MgSe, MgTe, PbS, PbSe, PbTe, SnS, SnSe, SnTe, CuF, CuCl, CuBr, CuI, etc., and the above materials can be selected as single crystal or polycrystalline mixture.

[0038] There are various methods for manufacturing quantum dots, such as the liquid phase method and the gas phase method, etc. The present invention does not particularly limit its manufacturing method. However, from the perspective of exhibiting high fluorescence emission efficiency, it is preferable to use semiconductor nanoparticles obtained by the hot soap method or the hot injection method. In the hot soap method or the hot injection method, the precursor reacts at a high temperature in a non-polar solvent with a high boiling point. In order to impart its dispersibility in the non-polar solvent and reduce surface defects, it is preferable to coordinate an organic ligand to the surface.

[0039] From the perspective of dispersibility, preferably, the ligand contains an aliphatic hydrocarbon. As such a ligand, for example, oleic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, octanoic acid, oleylamine, stearyl (octadecyl) amine, dodecyl (lauryl) amine, decylamine, octylamine, octadecanethiol, hexadecanethiol, tetradecanethiol, dodecanethiol, decanethiol, octanethiol, trioctylphosphine, trioctyloxidephosphine, triphenylphosphine, triphenyloxidephosphine, tributylphosphine, tributyloxidephosphine, etc. These ligands can be used alone or in combination of one or more.

[0040] (Ligand having a substituent coordinated with the quantum dot) In addition, the quantum dots contained in the quantum dot composition of the present invention are preferably coordinated with a ligand having a substituent that forms a siloxane bond, in addition to the above-mentioned ligands. The ligand having a substituent that forms a siloxane bond preferably has a substituent that interacts with or adsorbs on the surface of the quantum dots. Examples of the substituent that adsorbs on the surface of the quantum dots or reacts with the surface of the quantum dots include an amino group, a carboxyl group, a mercapto group, a phosphino group, a phosphine oxide group, a sulfonyl group, and a quaternary ammonium salt. Among them, from the viewpoint of coordination strength, an amino group, a carboxyl group, a mercapto group, a phosphino group, and a quaternary ammonium salt are preferred.

[0041] Examples of the substituent that forms a siloxane bond include compounds containing alkoxysilane such as trimethoxysilyl, triethoxysilyl, dimethoxymethylsilyl, diethoxymethylsilyl, dimethylmethoxysilyl, and ethyldimethylsilyl, compounds having a silazane bond, compounds having an Si-OH bond, compounds having an Si-X (X: halogen) bond, and carboxylic acids. Among them, since the reaction can be carried out under mild conditions and no acid is produced as a by-product of the reaction, ligands containing alkoxysilane, silazane, or Si-OH are preferably used.

[0042] (Surface coating layer) The quantum dot composition of the present invention contains a surface coating layer having a siloxane bond on the surface of the quantum dots. At this time, it is preferred to coat the surface of the quantum dots with a polymer such as polysiloxane. Therefore, it is preferred to form a quantum dot surface coating layer containing polysiloxane by reacting with a substituent that forms a siloxane bond, and the substituent is contained in the ligand having the substituent coordinated with the quantum dots as described above.

[0043] In addition, the surface coating layer on the surface of the quantum dots contained in the quantum dot composition of the present invention preferably has at least one or more substituents (reactive substituents) that can polymerize with the polymerizable polymer contained in the polymerizable polymer composition described later. The substituent that polymerizes with the polymerizable polymer is preferably contained in the surface coating layer by forming a covalent bond. This is because it is difficult to fall off during the subsequent purification process compared to the case of forming an association with the surface-coated quantum dots or being contained in the quantum dot surface or surface coating layer in a coordinated manner.

[0044] Examples of the substituent that polymerizes with the polymerizable polymer include a vinyl group, an acrylic group, a methacrylic group, a hydroxyl group, a phenolic hydroxyl group, an epoxy group, a sulfonyl group, a carboxyl group, and a thiol group. Since aggregation is not likely to occur, one or more reactive substituents selected from a vinyl group, an acrylic group, a methacrylic group, a hydroxyl group, a phenolic hydroxyl group, and an epoxy group are preferred.

[0045] The study also found that when there are more than 4.0 mmol of free thiol groups per gram of quantum dots in the surface coating layer, a dark reaction will occur with the above-mentioned reactive substituents, thereby inhibiting curing or generating residues. Therefore, the amount of free thiol groups per gram of quantum dots must be 4.0 mmol or less, preferably 3.0 mmol or less, and more preferably 1.0 mmol or less. Thiols are commonly used in the synthesis of quantum dots and are included as ligands in most quantum dots. Free thiol groups not coordinated to the surface of the quantum dots can be removed by purification, but if the purification is insufficient, they will remain on the surface of the quantum dots and cause a dark reaction. Preferably, the amount of free thiol groups is 3.0 mmol or less per gram of quantum dots because this will not inhibit curing. The less free thiol groups, the better, and there is no specific lower limit, but it can be, for example, 0.05 mmol or more per gram of quantum dots.

[0046] (Polymerizable polymer composition) The quantum dot-containing composition of the present invention is a mixture of quantum dots and a polymerizable polymer composition. The polymerizable polymer composition includes a polymerizable polymer as a base polymer and a polymerization initiator, and may also include an organic solvent, a polymerizable crosslinking agent, a photoacid generator, an antioxidant, a light scattering agent, etc. Polymers derived from acrylic acid, methacrylic acid, acrylate, and methacrylate, copolymers of various combinations, polymers with (meth)acrylic glycidyl ester as a repeating unit, and polymers containing a siloxane skeleton, a urethane skeleton, a silphenyl skeleton, a norbornene skeleton, a fluorene skeleton, or an isocyanurate skeleton can be appropriately used. The polymers used can be appropriately selected according to the application. For example, it includes acrylic resins, alkyd resins, melamine resins, epoxy resins, silicone resins, polyvinyl alcohol, polyvinylpyrrolidone, polyamides, polyamideimides, polyimide precursors such as polyimides and their esterification products, and reaction products of tetracarboxylic dianhydrides and diamines. In addition, polymerizable substituents are introduced into these polymerizable polymers, and curing can be carried out by using them in combination with a polymerization initiator. Examples of free radical polymerizable substituents include vinyl, acrylic, methacrylic, thiol groups, etc., all of which can be appropriately used. Examples of cationic polymerizable substituents include hydroxyl, phenolic hydroxyl, epoxy, glycidyl, oxetanyl, isocyanate groups, etc., all of which can be appropriately used. In addition, a carboxyl group can be introduced to impart basic developability. Among them, preferably, it has one or more polymerizable substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups.

[0047] Preferably, the quantum dot composition of the present invention further comprises a polymerization initiator. The polymerization initiator may be a thermal polymerization initiator or a photo-polymerization initiator, which can be appropriately used according to the base polymer. As a photo-radical polymerization initiator, for example, the Irgacure (registered trademark) series sold by BASF Corporation can be cited, such as Irgacure 290, Irgacure 651, Irgacure 754, Irgacure 184, Irgacure 2959, Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 819, Irgacure 1173, etc. In addition, examples of the Darocure (registered trademark) series include TPO and Darocure 1173, etc. Additionally, known thermal radical polymerization initiators or photo-cationic polymerization initiators may also be included.

[0048] The content of the polymerization initiator is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of the added polymerizable polymer.

[0049] The quantum dot composition of the present invention may also contain a solvent to improve its coatability. From the perspective of compatibility with quantum dots, organic solvents are preferred, such as ketones, alkylene glycol ethers, alcohols, and aromatic compounds. Acetone, methyl ethyl ketone, cyclohexanone, etc. in ketones can be appropriately used; methyl cellosolve (ethylene glycol monomethyl ether), butyl cellosolve (ethylene glycol monobutyl ether), methyl cellosolve acetate, cellosolve acetate, butyl cellosolve acetate, 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 monomethyl ether acetate, diethylene glycol methyl ether acetate, etc. in alkylene glycol ethers. Methanol, ethanol, isopropyl alcohol, n-butanol, 3-methyl-3-methoxybutanol, etc. in alcohols, and benzene, toluene, xylene, etc. in aromatic compounds.

[0050] In addition, the quantum dot composition of the present invention may also contain a polymerizable crosslinking agent, a photoacid generator, an antioxidant, a light scattering agent, etc., which are not particularly limited, but preferably do not affect the coatability of the quantum dot composition.

[0051] (Method for manufacturing a quantum dot composition) The present invention provides a method for manufacturing the quantum dot composition described above, the quantum dot composition contains quantum dots that emit fluorescence in response to excitation light, and the manufacturing method includes: A ligand exchange step of mixing a solution in which the quantum dots are dispersed with a ligand having a substituent capable of forming a siloxane bond and coordinating the ligand to the outermost surface of the quantum dots; A surface coating layer forming step of, after the ligand exchange step, reacting a compound that reacts with the substituent capable of forming the siloxane bond to form polysiloxane with the substituent capable of forming the siloxane bond, thereby forming a surface coating layer; A purification step of, after the surface coating layer forming step, purifying to make the content of free thiol groups contained in the surface coating layer 4.0 mmol or less per 1 g of the quantum dots; and A polymerizable polymer composition mixing step of, after the purification step, mixing the quantum dots coated with the surface coating layer with the polymerizable polymer composition.

[0052] The quantum dot-containing composition of the present invention can be produced, for example, by the following method. First, quantum dots coordinated with a ligand containing a long-chain hydrocarbon are dispersed in a hydrophobic solvent to obtain a solution in which the quantum dots are dispersed, and ligand exchange is carried out by mixing with a ligand having a substituent capable of forming a siloxane bond and a substituent coordinated to the surface of the quantum dots. The conditions for the ligand exchange reaction, such as the addition amount of the ligand, heating temperature, time, light irradiation, etc., are appropriately changed according to the type of the ligand.

[0053] Next, a compound that reacts with a substituent forming a siloxane bond to generate a polysiloxane is reacted with a quantum dot coordinated with a ligand having a substituent forming the siloxane bond, thereby performing a reaction to form a polysiloxane and forming a surface coating layer containing a siloxane bond. The sol-gel method can be suitably used as a general method for forming a polysiloxane bond. However, since quantum dots are susceptible to acidic conditions and moisture, the sol-gel method under basic conditions is preferred, and the non-hydrolytic sol-gel method using diphenylsilanediol, tetramethyldisiloxanediol, etc. is more preferred. In addition, the surface coating layer on the surface of the quantum dots contained in the quantum dot-containing composition of the present invention preferably has at least one substituent (reactive substituent) or the same skeletal structure that can polymerize with the polymer contained in the aforementioned polymerizable polymer composition. A compound having a substituent or the same skeletal structure that polymerizes with the polymerizable polymer is preferably contained in the surface coating layer by forming a covalent bond. The method for forming a covalent bond is not particularly limited. For example, the following method can be suitably used: introducing a substituent forming a siloxane bond into a compound having a substituent or the same skeletal structure that polymerizes with the polymerizable polymer, and adding the introduced substituent during the above non-hydrolytic sol-gel reaction process, thereby containing it in the surface coating layer in a state of forming a covalent bond; or introducing a substituent that polymerizes with the polymerizable polymer contained in the polymerizable polymer composition during the above non-hydrolytic sol-gel reaction process, and then reacting with the polymerizable polymer or monomer to introduce it into the surface coating layer.

[0054] After forming the surface coating layer, unreacted substances are removed by purification, and the content of free thiol groups contained in the surface coating layer is formed to be 4.0 mmol or less per 1 g of the quantum dots. Then, by mixing the quantum dots coated with the surface coating layer with the polymerizable polymer composition, a quantum dot-containing composition can be produced. By forming the surface coating layer, the compatibility with the polymerizable polymer composition can be improved, and a quantum dot-containing composition in which quantum dots are uniformly dispersed without aggregation can be produced.

[0055] In the present invention, the purification method is not particularly limited. For example, it can be purified by adding ethanol to precipitate the reaction solution, followed by centrifugation to remove the supernatant.

[0056] In the present invention, the method for measuring the content of free thiol groups in the surface coating layer is not particularly limited. For example, 1 g of DTNB (5,5'-dithiobis(2-nitrobenzoic acid)) is dissolved in 100 mL of EtOH, the solid concentration is calculated from the weight change of the quantum dot toluene solution before and after removing the solvent, 1 mL of the DTNB solution is added to 5 mL of the quantum dot toluene solution, left for 1 hour, the absorbance at 412 nm is measured with a UV-visible absorption spectrometer, and from the molar absorbance (ε = 1.55×10 4 ) of the resulting 2-nitro-5-mercaptobenzoic acid, the content of free thiol groups can be measured.

[0057] (Wavelength conversion component) The wavelength conversion component of the present invention is a cured product obtained by curing the above-mentioned quantum dot composition. The form of the wavelength conversion component in the present invention is not particularly limited. For example, there can be mentioned: a wavelength conversion film obtained by dispersing a quantum dot composition in a resin by processing into a sheet and then curing; a wavelength conversion color filter obtained by patterning with an inkjet or resist material, etc. The manufacturing method of the wavelength conversion component is not particularly limited. For example, a wavelength conversion component can be obtained by coating a quantum dot composition on a transparent film or substrate such as PET or polyimide, followed by curing and laminating processes.

[0058] For coating on a transparent film, spraying methods such as spraying or inkjet, spin coating or bar coating machines can be used.

[0059] The curing method of the quantum dot composition can be carried out, for example, by heating the film coated with the quantum dot composition at 60°C for 2 hours and then at 150°C for 4 hours. In addition, the quantum dot composition can also be cured by a photopolymerization reaction. For example, it can be cured by irradiating with light of wavelength 365 nm and output power 4000 mW / cm 2 for 20 seconds using a UV LED irradiation device. There is no particular limitation, and it can be appropriately adjusted according to the use.

[0060] By introducing a substituent that polymerizes with the polymerizable polymer in the polymerizable polymer composition into such a surface coating layer, a wavelength conversion component with high reliability after curing and without aggregation and curing inhibition can be manufactured. Examples

[0061] The present invention will be further specifically described below with reference to examples and comparative examples, but the present invention is not limited thereto. InP / ZnSe / ZnS core-shell quantum dots are used as the quantum dot material in this example.

[0062] (Example 1) (Quantum dot core synthesis process) Add 0.23 g (0.9 mmol) of palmitic acid, 0.088 g (0.3 mmol) of indium acetate, and 10 mL of 1-octadecene into a flask, heat and stir under reduced pressure at 100 °C, degas for 1 hour while dissolving the raw materials. Then, purge the inside of the flask with nitrogen, add 0.75 mL (0.15 mmol) of a 0.2 M solution composed of a mixture of tris(trimethylsilyl)phosphine and trioctylphosphine, raise the temperature to 300 °C, the solution changes from yellow to red, and confirm the formation of core particles.

[0063] (Quantum dot shell synthesis process) Next, add 2.85 g (4.5 mmol) of zinc stearate and 15 mL of 1-octadecene into another flask, heat and stir under reduced pressure at 100 °C, degas for 1 hour while dissolving, prepare a 0.3 M zinc stearate octadecene solution, add 3.0 mL (0.9 mmol) to the reaction solution after core synthesis, and cool to 200 °C. Next, add 0.474 g (6.0 mmol) of selenium and 4 mL of trioctylphosphine into another flask, heat to 150 °C to dissolve it, prepare a 1.5 M selenium trioctylphosphine solution, cool the reaction solution after the core synthesis process to 200 °C, raise the temperature to 320 °C within 30 minutes, and successively add the selenium trioctylphosphine solution in increments of 0.1 mL until the total amount reaches 0.6 mL (0.9 mmol), and maintain at 320 °C for 10 minutes, then cool to room temperature. Add 0.44 g (2.2 mmol) of zinc acetate, heat and stir to dissolve it under reduced pressure at 100 °C. Purge the inside of the flask with nitrogen again and raise the temperature to 230 °C, add 0.98 mL (4.0 mmol) of 1-dodecanethiol and maintain for 1 hour. Cool the obtained solution to room temperature to prepare a core-shell type quantum dot-containing solution.

[0064] (Ligand exchange process) Use (3-mercaptopropyl)triethoxysilane (Tokyo Chemical Industry Co., Ltd.) as the ligand, which has a substituent forming a siloxane bond and a substituent coordinating with the surface of the quantum dot. As the ligand exchange reaction, add (3-mercaptopropyl)triethoxysilane (3.0 mmol) to the solution after the shell synthesis process cooled to room temperature, and stir for 24 hours. After the reaction is completed, add ethanol to precipitate the reaction solution, perform centrifugation, and remove the supernatant. Perform the same purification again and disperse it in toluene to prepare a quantum dot solution coordinated with a ligand having a substituent forming a siloxane bond.

[0065] (Surface coating layer formation process, and purification process) Triethoxyvinylsilane (4.0 mmol), diphenylsilanediol (6.0 mmol), barium hydroxide monohydrate (0.15 mmol), and the quantum dot toluene solution after the ligand exchange step were added to a flask purged with nitrogen, and heated and stirred at 65 °C for 24 hours. After the reaction was completed, it was cooled to room temperature, ethanol was added to precipitate the reaction solution, centrifuged, the supernatant was removed, and it was dispersed in toluene for purification.

[0066] (Titration of free thiol amount) 1 g of DTNB (5,5'-Dithiobis(2-nitrobenzoic acid)) was dissolved in 100 mL of EtOH. Next, the solid concentration was calculated based on the weight change of the quantum dot toluene solution before and after removing the solvent. 1 mL of the DTNB solution was added to 5 mL of the quantum dot toluene solution and left for 1 hour. Then, the absorbance at 412 nm was measured using a UV-visible absorption spectrometer (V-750 manufactured by JASCO Corporation, Japan), and the amount of free thiol groups (SH amount) was measured from the molar absorbance of 2-nitro-5-mercaptobenzoic acid generated (ε = 1.55×10 4 ). Based on the obtained free molar mass and the solid concentration of the above quantum dots, the amount of free SH contained in the quantum dots was calculated, and the result was 1.01 mmol per 1 g of quantum dots.

[0067] (Polymerizable polymer composition mixing step) The solution after the surface coating layer formation step dispersed in toluene and methacrylic acid-modified silicone oil X-32-3817-3 (Shin-Etsu Chemical Co., Ltd.) were weighed and mixed so that the proportion of the non-volatile components of the quantum dots was 20% by mass. After mixing, the solvent was removed using an evaporator to obtain a quantum dot composition.

[0068] (Manufacturing process of wavelength conversion component) The obtained quantum dot composition was used to fabricate a wavelength conversion component. The quantum dot composition was defoamed using a stirring defoamer, poured onto a PET film, and a film was formed using a doctor blade. Next, in a nitrogen atmosphere, the formed film was irradiated with light having a wavelength of 365 nm and an output power of 4000 mW / cm2 for 20 seconds using a UV LED irradiation device to photocure the quantum dot-containing layer, thereby fabricating a 50-μm wavelength conversion component.

[0069] (Measurement of light emission wavelength, fluorescence full width at half maximum, and fluorescence emission efficiency) In the examples and comparative examples, a quantum efficiency measurement system (QE-2100) manufactured by Otsuka Electronics Co., Ltd. was used to evaluate the fluorescence emission characteristics of the quantum dots. The emission wavelength, fluorescence full width at half maximum, and fluorescence emission efficiency (internal quantum efficiency) of the quantum dots were measured at an excitation wavelength of 450 nm.

[0070] (Reliability test) The obtained wavelength conversion component was treated under the conditions of 85 °C and 85% RH (relative humidity) for 250 hours, and the fluorescence emission efficiency of the treated wavelength conversion component was measured to evaluate its reliability.

[0071] [Comparative Example 1] The quantum dot shell synthesis process was carried out in the same manner as in Example 1. In the ligand exchange process, instead of performing the process of removing excess ligands by adding ethanol after ligand exchange to precipitate the quantum dots for purification, the surface coating layer formation process was carried out. The amount of free SH was measured in the same manner as in Example 1, and it was found that 8 mmol was contained per 1 g of quantum dots. The rest was prepared in the same method as in Example 1. During the manufacturing process of the wavelength conversion component, there were no phenomena such as thickening, inability to remove bubbles, and inability to form a uniform thin film.

[0072] [Comparative Example 2] Up to the quantum dot shell synthesis process, it was prepared in the same manner as in Example 1.

[0073] (Ligand exchange process) (3-Dimethylaminopropyl)triethoxysilane (Tokyo Chemical Industry Co., Ltd.) was used as the ligand, which has a substituent forming a siloxane bond and a substituent coordinating with the surface of the quantum dots. As the ligand exchange reaction, (3-dimethylaminopropyl)triethoxysilane (3.0 mmol) was added to the solution after the shell synthesis process that had been cooled to room temperature and stirred for 24 hours. After the reaction was completed, it was prepared in the same manner as in Comparative Example 1. Similarly to Example 1, the amount of free SH was measured after the surface coating layer formation process, and the result was 6 mmol per 1 g of quantum dots. The rest was prepared in the same method as in Example 1. During the manufacturing process of the wavelength conversion component, there were no phenomena such as thickening, inability to remove bubbles, and inability to form a uniform thin film.

[0074] [Example 2] The surface coating layer formation process and the purification process were prepared in the same manner as in Example 1.

[0075] (Polymerizable polymer composition mixing process) Weigh the solution after the surface coating layer formation process and acrylic resin RA-4101 (Negami Sangyo Co., Ltd.) dispersed in toluene, such that the proportion of the non-volatile components of the quantum dots is 20% by mass. Add 5 parts by mass of the photo radical generator Irgacure 1173 to 100 parts by mass of the non-volatile components of the acrylic resin and mix. After mixing, remove the toluene solvent by vacuum distillation to obtain a quantum dot composition.

[0076] (Method for manufacturing a wavelength conversion component) Use the obtained quantum dot composition to fabricate a wavelength conversion component. Degas the quantum dot composition under vacuum. Pour the quantum dot composition with a solid component concentration of 20% into a fluororesin-coated mold with sides of 20 cm x 10 cm and a thickness of 500 μm, and then heat it on a hot plate at 120 °C for 1 hour. While blowing off the solvent, prepare a quantum dot-containing layer. Cut a part and develop it with a PGMEA solution to confirm no residual film. Then, in a nitrogen atmosphere, use a UVLED irradiation device to irradiate the remaining quantum dot-containing layer with light having a wavelength of 365 nm and an output power of 4000 mW / cm 2 for 20 seconds to perform photocuring, thereby preparing a 100-μm wavelength conversion component.

[0077] [Comparative Example 3] Prepare up to the surface coating layer formation process and the purification process in the same manner as in Comparative Example 1, and manufacture the wavelength conversion component in the same manner as in Example 2 for the rest. When developing with a PGMEA solution, a residual film remained, thus confirming that the dark reaction was occurring. Then, in a nitrogen atmosphere, use a UVLED irradiation device to irradiate the remaining quantum dot-containing layer with light having a wavelength of 365 nm and an output power of 4000 mW / cm 2 for 20 seconds to perform photocuring, thereby preparing a 100-μm wavelength conversion component.

[0078] [Example 3] Prepare up to the ligand exchange process in the same manner as in Example 1.

[0079] (Surface coating layer formation process, and purification process) Triethoxysilyl methacrylate (4.0 mmol), diphenylsilanediol (6.0 mmol), barium hydroxide monohydrate (0.15 mmol) and the quantum dot toluene solution after the ligand exchange process were added to a flask purged with nitrogen, and heated and stirred at 65°C for 24 hours. After the reaction is completed, cool to room temperature, add ethanol to precipitate the reaction solution, centrifuge and remove the supernatant. Disperse it in toluene and add it to a flask that has been purged with nitrogen in advance. Add 2 parts by mass of isocyanuric acid derivative DA-MGIC (Shikoku Chemical Industry Co., Ltd.) for every 100 parts by mass of quantum dot toluene solution. Furthermore, add 1 part by mass of Irgacure 1173 to 100 parts by mass of DA-MGIC, stir and mix, and use a UVLED irradiation device with an irradiation wavelength of 365nm and an output power of 4000mW / cm 2 After the reaction, ethanol was added to precipitate the solution, and the solution was centrifuged to remove the supernatant and re-dispersed in toluene for purification. The amount of free SH was measured in the same manner as in Example 1, and it was found that 0.3 mmol was contained per gram of quantum dots.

[0080] (Polymerizable polymer composition mixing step) The epoxy-containing silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., CAS No. 2253674-54-1) and the solution obtained after the surface coating layer formation process dispersed in toluene were weighed and mixed so that the non-volatile component ratio of the quantum dots was 20% by mass. 2 parts by mass of the photoacid generator CPI-310FG (manufactured by San-Apro Co., Ltd.) and 20 parts by mass of the crosslinking agent THI-DE were weighed and mixed relative to 100 parts by mass of the non-volatile component of the silicone resin. After mixing, the toluene solvent was removed by reduced pressure distillation to obtain a composition containing quantum dots.

[0081] (Method for manufacturing wavelength conversion component) The obtained quantum dot composition is used to make a wavelength conversion component. The quantum dot composition is vacuum degassed, and the quantum dot composition with a solid content concentration of 20% is poured into a 20cmx10cm square, 500μm thick fluororesin coated mold, and then heated on a hot plate at 120°C for 1 hour. While blowing off the solvent, a quantum dot-containing layer is prepared, and a portion is cut out and developed with a PGMEA solution to confirm that there is no residual film. Then, in a nitrogen atmosphere, a UVLED irradiation device is used to irradiate the remaining quantum dot-containing layer with a wavelength of 365nm and an output power of 4000mW / cm 2 The photocuring was performed by irradiating the sample with light of 100 μm for 20 seconds, thereby preparing a wavelength conversion component having a thickness of 100 μm.

[0082] [Example 4] Until the ligand exchange step, the preparation was carried out in the same manner as in Example 1.

[0083] (Surface coating layer formation step and purification step) Triethoxysilylpropyl methacrylate (4.0 mmol), diphenylsilanediol (6.0 mmol), barium hydroxide monohydrate (0.15 mmol), and the quantum dot toluene solution after the ligand exchange step were added to a flask purged with nitrogen, and heated and stirred at 65 °C for 24 hours. After the reaction was completed, it was cooled to room temperature, ethanol was added to precipitate the reaction solution, and centrifuged to remove the supernatant. It was dispersed in toluene and added to a flask pre-purged with nitrogen. 2 parts by mass of BIOAP-FL (Asahi Organic Materials Industry), a phenol-reactive compound having a fluorene skeleton, was added per 100 parts by mass of the quantum dot toluene solution. Further, 1 part by mass of Irgacure 1173 was added relative to 100 parts by mass of BIOAP-FL, and after stirring and mixing, it was irradiated with light having a wavelength of 365 nm and an output power of 4000 mW / cm 2 for 20 seconds using a UVLED irradiation device. After the reaction was completed, ethanol was added to precipitate it, and after centrifugation, the supernatant was removed and it was dispersed in toluene again for purification. The amount of free SH was measured in the same manner as in Example 1, and it was found that 0.2 mmol was contained per 1 g of the quantum dots.

[0084] (Polymerizable polymer composition mixing step) Phenol-crosslinkable silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., CAS No. 916059-41-1) and the solution obtained after the surface coating layer formation step dispersed in toluene were weighed and mixed so that the proportion of the non-volatile components of the quantum dots was 20% by mass. A photoacid generator CPI-310FG (manufactured by San-Apro Co., Ltd.) and 20 parts by mass of a crosslinking agent THI-DE were weighed and mixed relative to 2 parts by mass of the non-volatile components of 100 parts by mass of the silicone resin. After mixing, the toluene solvent was removed by vacuum distillation to obtain a quantum dot composition-containing product.

[0085] (Method for manufacturing a wavelength conversion component) The obtained quantum dot composition-containing product was used to fabricate a wavelength conversion component. The quantum dot composition-containing product was vacuum degassed, and the quantum dot composition-containing product having a solid component concentration of 20% was poured into a fluororesin-coated mold having a size of 20 cm x 10 cm square and a thickness of 500 μm, and then heated on a hot plate at 120 °C for 1 hour while blowing off the solvent to prepare a quantum dot-containing layer. A part was cut out and developed with a PGMEA solution to confirm no residual film. Then, in a nitrogen atmosphere, the remaining quantum dot-containing layer was irradiated with light having a wavelength of 365 nm and an output power of 4000 mW / cm2 The light of [wavelength] is irradiated for 20 seconds for photocuring to prepare a wavelength conversion member with a thickness of 100 μm.

[0086] [Example 5] The ligand exchange process was carried out in the same manner as in Comparative Example 1, and then the polymerizable polymer composition mixing process was carried out in the same manner as in Example 4. The amount of free SH was measured in the same manner as in Example 1, and it was found that each 1 g of quantum dots contained 3.5 mmol.

[0087] (Manufacturing method of wavelength conversion member) The obtained quantum dot-containing composition was used to produce a wavelength conversion member. The quantum dot-containing composition was degassed under vacuum, and the quantum dot-containing composition with a solid component concentration of 20% was poured into a fluororesin-coated mold with a size of 20 cm × 10 cm and a thickness of 500 μm. Then, it was heated on a hot plate at 120 °C for 1 hour while blowing off the solvent to prepare a quantum dot-containing layer. A part was cut out and developed with a PGMEA solution to confirm that there was no residual film. Then, in a nitrogen atmosphere, the remaining quantum dot-containing layer was irradiated with light having a wavelength of 365 nm and an output power of 4000 mW / cm 2 for 20 seconds for photocuring to prepare a 100-μm wavelength conversion member. Some residual liquid was found, indicating that the curing was inhibited. The remaining liquid component was wiped off with a cloth to prepare a wavelength conversion member.

[0088] [Comparative Example 4] The surface coating layer formation process was carried out in the same manner as in Comparative Example 1, and then the polymerizable polymer composition mixing process was carried out in the same manner as in Example 4. The amount of free SH was measured in the same manner as in Example 1, and it was found that each 1 g of quantum dots contained 4.2 mmol.

[0089] (Manufacturing method of wavelength conversion member) The obtained quantum dot-containing composition was used to produce a wavelength conversion member. The quantum dot-containing composition was degassed under vacuum, and the quantum dot-containing composition with a solid component concentration of 20% was poured into a fluororesin-coated mold with a size of 20 cm × 10 cm and a thickness of 500 μm. Then, it was heated on a hot plate at 120 °C for 1 hour while blowing off the solvent to prepare a quantum dot-containing layer. A part was cut out and developed with a PGMEA solution to confirm that there was no residual film, and it was confirmed that the dark reaction was in progress. Then, in a nitrogen atmosphere, the remaining quantum dot-containing layer was irradiated with light having a wavelength of 365 nm and an output power of 4000 mW / cm 2 for 20 seconds for photocuring to prepare a 100-μm wavelength conversion member.

[0090] The comparison results of Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 1. Table 1

[0091] The internal quantum efficiency of the cured quantum dot composition (wavelength conversion component) and the degradation rate of the internal quantum efficiency after reliability evaluation, the presence or absence of thickening or residual film, and the presence or absence of poor photocuring are shown. The results in Table 1 show that, compared with the Examples, the internal quantum efficiency of the Comparative Examples is lower, and the emission wavelength also shifts significantly to the long wavelength side. On the one hand, when comparing the results of the reliability test (treatment at 85 °C, 85% RH, for 250 hours), the Comparative Examples showed greater degradation than the Examples, but due to the formation of the surface coating layer, the stability was relatively good. Regarding the thickening of the quantum dot composition, comparing Example 1 with Comparative Examples 1 and 2, it can be seen that thickening occurred in the Comparative Examples, resulting in residual bubbles after photocuring and deteriorating the film quality. In other Comparative Examples, no thickening was observed, which may be due to the addition of the organic solvent PGMEA. On the other hand, for Examples 2 to 5 and Comparative Examples 3 to 4, comparing the presence or absence of residual film and photocuring defects after PGMEA treatment, no residual film was produced in the Examples, and no thickening or other phenomena occurred. In addition, except for Example 5, no curing defects occurred, and a quantum dot-containing layer was formed, while Comparative Examples 3 and 4 produced a residual film after PGMEA treatment, indicating that the dark reaction with the remaining thiol groups was ongoing.

[0092] As described above, it has been confirmed that the quantum dot composition of the present invention exhibits high stability and has good film quality after curing, and can be applied to quantum dot resists and quantum dot inkjets.

[0093] This specification includes the following aspects. [1]: A quantum dot composition containing quantum dots that emit fluorescence in response to excitation light, characterized in that the quantum dot composition is a mixture of the quantum dots and a polymerizable polymer composition, the surface of the quantum dots contains a surface coating layer having a siloxane bond, and the content of free thiol groups contained in the surface coating layer is 4.0 mmol or less per 1 g of the quantum dots. [2]: The quantum dot composition according to the above [1], characterized in that the content of the free thiol groups contained in the surface coating layer is 3.0 mmol or less per 1 g of the quantum dots. [3]: The quantum dot composition according to the above [2], characterized in that the content of the free thiol groups contained in the surface coating layer is 1.0 mmol or less per 1 g of the quantum dots. [4], The quantum dot-containing composition according to any one of the above [1] to the above [3], characterized in that the surface coating layer has one or more reactive substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups. [5]: The quantum dot-containing composition according to any one of the above [1] to the above [4], characterized in that the polymerizable polymer contained in the polymerizable polymer composition has one or more polymerizable substituents selected from vinyl: acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups. [6]: A wavelength conversion member, characterized in that it is a cured product of the quantum dot-containing composition according to any one of the above [1] to the above [5]. [7]: A method for producing a quantum dot-containing composition according to any one of the above [1] to the above [5], the composition containing quantum dots that emit fluorescence in response to excitation light, the production method comprising: A ligand exchange step of mixing a solution in which the quantum dots are dispersed with a ligand having a substituent that forms a siloxane bond, and coordinating the ligand to the outermost surface of the quantum dots; A surface coating layer formation step of, after the ligand exchange step, reacting a compound that reacts with the substituent that forms the siloxane bond to form a polysiloxane with the substituent that forms the siloxane bond to form a surface coating layer; A purification step of, after the surface coating layer formation step, purifying to make the content of free thiol groups contained in the surface coating layer 4.0 mmol or less per 1 g of the quantum dots; and A polymerizable polymer composition mixing step of, after the purification step, mixing the quantum dots coated with the surface coating layer with the polymerizable polymer composition.

[0094] In addition, the present invention is not limited to the above embodiments. The above embodiments are merely examples, and any technical solution having a configuration substantially the same as the technical idea described in the claims of the present invention and exhibiting the same function and effect is included in the technical scope of the present invention.

Claims

1. A quantum dot composition, the quantum dot composition containing quantum dots that emit fluorescence in response to excitation light, characterized in that the quantum dot composition is a mixture of the quantum dots and a polymerizable polymer composition, the surface of the quantum dots having a surface coating layer with a siloxane bond, and the content of free thiol groups contained in the surface coating layer being 4.0 mmol or less per 1 g of the quantum dots.

2. The quantum dot composition according to claim 1, characterized in that the content of the free thiol groups contained in the surface coating layer is 3.0 mmol or less per 1 g of the quantum dots.

3. The quantum dot composition according to claim 2, characterized in that the content of the free thiol groups contained in the surface coating layer is 1.0 mmol or less per 1 g of the quantum dots.

4. The quantum dot composition according to claim 1, characterized in that the surface coating layer has one or more reactive substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups.

5. The quantum dot composition according to claim 1, characterized in that the polymerizable polymer contained in the polymerizable polymer composition has one or more polymerizable substituents selected from vinyl, acrylic, methacrylic, hydroxyl, phenolic hydroxyl, and epoxy groups.

6. A wavelength conversion component, characterized in that, The wavelength conversion member is a cured product of the quantum dot composition according to any one of claims 1 to 5.

7. A method for producing a quantum dot composition, the quantum dot composition being the quantum dot composition according to any one of claims 1 to 5 and containing quantum dots that emit fluorescence in response to excitation light, characterized in that the production method includes: a ligand exchange step of mixing a solution in which the quantum dots are dispersed with a ligand having a substituent that forms a siloxane bond and coordinating the ligand to the outermost surface of the quantum dots; a surface coating layer formation step of, after the ligand exchange step, reacting a compound that reacts with the substituent that forms the siloxane bond to form polysiloxane with the substituent that forms the siloxane bond to form a surface coating layer; a purification step of, after the surface coating layer formation step, purifying to make the content of free thiol groups contained in the surface coating layer 4.0 mmol or less per 1 g of the quantum dots; and a polymerizable polymer composition mixing step of, after the purification step, mixing the quantum dots coated with the surface coating layer with the polymerizable polymer composition.

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