Luminescent material, ink composition, wavelength conversion member, wavelength conversion layer

Abstract

To provide a photoresponsive material comprising perovskite quantum dots with the particle surfaces protected to maintain the transformation quantum yield even in contact with a medium comprising a polar solvent.SOLUTION: A photoresponsive material contains: nanoparticles which have a perovskite crystal structure; and a shell-like ligand which has a plurality of bonding parts each comprising an ionic structural unit, and a polymer part that is bonded to the nanoparticles at a plurality of positions by the intermediary of the plurality of bonding parts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a light-responsive material and a light-responsive composition that emit light upon irradiation with light.

Background Art

[0002] Quantum dots having a perovskite crystal structure are known to be applicable to organic EL materials and quantum dot light-responsive materials because they have a narrow full width at half maximum in spectral sensitivity characteristics and exhibit high color purity. Patent Document 1 discloses quantum dots including a perovskite crystal structure that absorb light from a light-emitting element and convert it into any of RGB light and emit light, and a light conversion layer including such quantum dots.

[0003] On the other hand, it is known that quantum dots having a particle size of several to twenty nanometers are more likely to receive compositional fluctuations through the particle surface than in the bulk form because they are in a particle form with a large specific surface area. Patent Document 1 further discloses protecting the surface of quantum dots having a perovskite crystal structure by modifying the particle surface with a ligand containing an organic group.

[0004] Patent Document 2 discloses a technique for improving the stability of perovskite quantum dots by modifying the particle surface with a ligand containing an amphoteric surfactant. The surfactant contained in the ligand described in Patent Document 2 has a betaine structure in which atoms having positive and negative charges are located at non-adjacent positions within the same molecule and the molecule as a whole has no charge, and exhibits amphoteric ionicity.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When producing a photoreactive material or a light-emitting layer using perovskite quantum dots protected by the ligands described in Patent Documents 1 and 2, the quantum dots are in a form dispersed in a solid carrier or a liquid solvent. When such perovskite quantum dots are applied to a photoreactive material, the luminescence quantum yield may not be higher than expected.

[0007] When in contact with a solvent having a high dielectric constant such as alcohol, the ligand detaches from the quantum dot, and it is considered that the components move between the quantum dot lacking the ligand and the solvent, and the crystal structure of the perovskite crystal structure changes. Since quantum dots having a perovskite crystal structure may come into contact with surrounding polar solvents during storage, transportation, and manufacturing processes, it has been desired to provide a photoreactive material containing perovskite quantum dots with ensured stability against the surrounding environment. Quantum dots having a perovskite crystal structure have a higher luminescence quantum yield and are more active than non-perovskite luminescent nanoparticles, while having low stability in composition and crystal structure. Therefore, measures for stabilizing against external stimuli of nanoparticles with reduced luminescence quantum yield are expected to be measures for stabilizing against many activation factors including temperature rise, light reception, etc.

[0008] An object of the present invention is to provide a photoreactive material containing perovskite quantum dots whose particle surfaces are protected so that the luminescence quantum yield is maintained in at least either an environment where it is in contact with a medium containing a polar solvent or an environment where it is heated or receives light.

[0009] When quantum dots containing photoreactive nanoparticles are applied to a photodetector or a solar cell, the luminescence quantum yield described in the present specification is paraphrased as a photoelectric conversion quantum yield related to the generation of charge pairs. In the present specification, the luminescence quantum yield related to the wavelength conversion of light is treated as one form of the conversion quantum yield including the photoelectric conversion quantum yield related to photoelectric change.

[0010] That is, the present invention has been made in view of the above problems, and provides a photoresponsive material including perovskite quantum dots in which the particle surface is protected so that the conversion quantum yield is maintained even when in contact with a medium containing a polar solvent. **Means for Solving the Problems**

[0011] The photoresponsive material according to an embodiment of the present invention includes a shell portion having nanoparticles having a perovskite crystal structure, a plurality of bonding portions including structural units exhibiting ionic properties, and a polymer portion bonded to the nanoparticles at a plurality of locations via the plurality of bonding portions. **Advantages of the Invention**

[0012] According to the present invention, a photoresponsive material including perovskite quantum dots in which the particle surface is protected so that the emission quantum yield is maintained can be provided in at least one of an environment where it is in contact with a medium containing a polar solvent, an environment where the temperature is raised, or an environment where it is irradiated with light. **Brief Description of the Drawings**

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0014] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the constituent members described in these embodiments are not intended to limit the scope of this invention.

[0015] <First Embodiment> Using FIGS. 1(a) and (c), the photo-responsive material 100 according to the first embodiment will be described.

[0016] (Photo-responsive material) The photo-responsive material 100 according to the present embodiment includes, as shown in FIG. 1(a), nanoparticles 10 having a photo-responsive perovskite crystal structure with a surface coordinated by a shell-like ligand 20. The shell-like ligand 20 has a plurality of bonding parts 30 including structural units exhibiting ionic properties, and a polymer part 40 (organic polymer part 40) that binds to the nanoparticles 10 at a plurality of locations via the plurality of bonding parts 30.

[0017] (Nanoparticles) In this embodiment, the nanocrystal is a semiconductor nanocrystal having a perovskite crystal structure composed of an A site (monovalent cation), a B site (divalent cation), and an X site (monovalent anion including a halide anion). The perovskite crystal structure is also referred to as a perovskite structure, an ABX3 type crystal structure, or an ABX3 type structure. Also, a double perovskite crystal structure represented by A2B1B2X6 is included in the perovskite crystal structure.

[0018] [A site of perovskite structure] The A site employs a monovalent cation. The monovalent cations employed in the A site include ammonium cation (NH4 + ), and alkylammonium cations having 6 or less carbon atoms, formamidinium cation (HC(NH2)2 + ), guanidinium cation (C(NH2)3 + ), nitrogen-containing organic compound cations such as imidazolium cation, pyridinium cation, and pyrrolidinium cation, and alkali metal cations such as lithium cation (Li + ), sodium cation (Na + ), potassium cation (K + ), rubidium cation (Rb + ), and cesium cation (Cs + ).

[0019] Since these monovalent cations employed in the A site have a small ionic radius and are of a size that can enter the crystal lattice, the perovskite compound can form a stable three-dimensional crystal.

[0020] Preferable examples of the alkylammonium cation having 6 or less carbon atoms include methylammonium cation (CH3NH3 + ), ethylammonium cation (C2H5NH3 + ), and propylammonium cation (C3H7NH3 + ).

[0021] From the viewpoint of obtaining high luminous efficiency, it is preferable to use at least one of methylammonium cation, formamidinium cation, or cesium cation as the A-site. From the viewpoint of suppressing color change, it is more preferable to use cesium cation as the A-site. These monovalent cations employed at the A-site may be used in combination of two or more.

[0022] When the A-site is cesium cation, examples of the raw material for synthesizing the luminescent nanocrystal described below include cesium salts. Such cesium salts may be appropriately selected from cesium chloride, cesium bromide, cesium iodide, cesium hydroxide, cesium carbonate, cesium hydrogen carbonate, bicarbonate cesium, cesium formate, cesium acetate, cesium propionate, cesium pivalate, and cesium oxalate. Appropriate ones can be used according to the synthesis method from among these candidates of cesium salts.

[0023] When the A-site is another alkali metal cation, salts or the like in which the cesium element of the above-described cesium compound is replaced with another alkali metal cation element can be used as the raw material.

[0024] When the A-site is a nitrogen-containing organic compound cation such as methylammonium cation, for example, neutral compounds other than salts such as methylamine can be used as the raw material. These raw materials may be used in combination of two or more.

[0025] [Perovskite-type crystal structure B-site] For the B-site of the perovskite-type crystal structure, a divalent cation containing a divalent transition metal cation or a divalent main group metal cation is employed.

[0026] The divalent transition metal cations are scandium cation (Sc 2+ ), titanium cation (Ti 2 +), vanadium cation (V 2+ ), chromium cation (Cr 2+ ), manganese cation (Mn 2+ ), iron cation (Fe 2+) Cobalt cation (Co 2+ ) Nickel cation (Ni 2+ ) Copper cation (Cu 2+ ) Palladium cation (Pd 2+ ) Europium cation (Eu 2+ ) Ytterbium cation (Yb 2+ ) is adopted.

[0027] Divalent typical metal cations include magnesium cation (Mg 2+ ) Calcium cation (Ca 2+ ) Strontium cation (Sr 2+ ) Barium cation (Ba 2+ ) Zinc cation (Zn 2+ ) Cadmium cation (Cd 2+ ) Germanium cation (Ge 2+ ) Tin cation (Sn 2+ ) Lead cation (Pb 2+ ) may be adopted.

[0028] Among these divalent cations, divalent typical metal cations are preferred in terms of the growth of stable three-dimensional crystals, tin cation or lead cation is more preferred, and lead cation is particularly preferred from the viewpoint of obtaining high emission intensity. These divalent cations may be used in combination of two or more, and the perovskite crystal structure may be a so-called double perovskite type.

[0029] When the B site is a lead cation, examples of the raw material for the synthesis of the nanoparticles (luminescent nanocrystals) described later include lead compounds, and appropriate ones can be used according to the synthesis method. Examples of lead compounds include lead chloride, lead bromide, lead iodide, lead oxide, lead hydroxide, lead sulfide, lead carbonate, lead formate, lead acetate, lead 2-ethylhexanoate, lead oleate, lead stearate, lead naphthenate, lead citrate, lead maleate, and lead acetylacetonate. When the B site is another divalent metal cation, salts obtained by replacing the lead element of the above lead compounds with other divalent metal cation elements can be used as raw materials. These raw materials may be used in combination of two or more.

[0030] [X-site of perovskite crystal structure] For X in the perovskite crystal structure, a monovalent anion containing a halide anion is employed. Examples of the halide anion include fluoride anion (F - ), chloride anion (Cl - ), bromide anion (Br - ), iodide anion (I - ), and the like. Among them, chloride anion, bromide anion, or iodide anion is preferable from the viewpoint of forming a stable three-dimensional crystal and showing strong luminescence in the visible light region. When using chloride anion, the emission color is blue; when using bromide anion, it is green; and when using iodide anion, it is red.

[0031] Two or more kinds of halide anions may be used in combination. In particular, when chloride anion, bromide anion, and iodide anion are used in combination, the emission wavelength of the luminescent nanocrystal can be made the desired wavelength according to the content ratio of the anion species. That is, especially when chloride anion, bromide anion, and iodide anion are used in combination, it is preferable because an emission spectrum covering almost the entire visible light region from blue to red can be obtained while maintaining a narrow full width at half maximum according to the content ratio of the anion species.

[0032] The X-site may contain a monovalent anion other than the halide anion. Such monovalent anions other than the halide anion include pseudohalide anions such as cyanide anion (CN - ), thiocyanate anion (SCN - ), and isothiocyanate anion (CNS - ). As raw materials for synthesizing the nanoparticles (luminescent nanocrystals) described later, salts having A-site and B-site as counter cations such as cesium chloride and lead bromide, salts with other cations, etc. can be appropriately selected according to the synthesis method.

[0033] The nanoparticles (luminescent nanocrystals) in this embodiment can be manufactured by the following processes. For example, the hot injection method of mixing raw material solutions at high temperature and rapidly cooling after fine particle generation to obtain a stable product, and the ligand-assisted reprecipitation method of obtaining fine particles by reprecipitation using the difference in miscibility of the product in a solvent are adopted.

[0034] Also, under mild conditions around room temperature, a room temperature synthesis method is also an adopted manufacturing method, in which a separately prepared raw material solution for the X site is mixed with a mixed solution of a raw material for the A site and a raw material for the B site, which are non-halides not containing the component for the X site, to obtain fine particles. Furthermore, the mechanochemical method of reacting solid raw materials by mechanical mixing such as milling or ultrasonic treatment to obtain product fine particles, and the In situ synthesis method of directly growing crystals after applying the raw material solution on a substrate to obtain a reactant are adopted manufacturing methods.

[0035] (Shell-like ligand) As shown in Fig. 1(a), the light-responsive material 100 according to this embodiment includes nanoparticles 10 having a perovskite crystal structure, and shell-like ligands 20 that coordinate by binding to the surface of the nanoparticles 10 at a plurality of locations. The shell-like ligand 20 includes a plurality of binding portions 30 including a betaine structure 30b, and an organic polymer portion 40 that binds to the nanoparticles 10 at a plurality of locations via the plurality of binding portions 30.

[0036] Here, the betaine structure 30b corresponds to one of the structural units that has a positive charge and a negative charge at non-adjacent positions within the same molecule and exhibits zwitterionic properties without having a charge as a whole molecule. Therefore, it can be said that the shell-like ligand 20 of the present embodiment is a ligand having a plurality of bonding portions 30 having a structural unit exhibiting zwitterionic properties and a polymer portion 40 coordinated to the photo-responsive nanoparticles 10 via the plurality of bonding portions 30. The bonding portion 30 includes a betaine structure 30b related to the bonding with the nanoparticles and a connecting portion 30j including a bond 33 at the end related to the bonding with the organic polymer portion 40. In FIG. 1(a), the photo-responsive material 100 is stably dispersed in the solvent 90. Similarly, in FIG. 1(a), the luminescent nanoparticles 10 coordinated with the shell-like ligand 20 around are dispersed in the solvent 90 and protected from the solvent 90 by the shell-like ligand 20. The nanoparticles 10 may also be protected from attacks by a dispersion component or a dissolution component (not shown) dispersed or dissolved in the solvent 90. The structure exhibiting zwitterionic properties can be paraphrased as one form of the form exhibiting ionic properties in a part of the structural unit.

[0037] The shell-like ligand 20 having a structural unit containing a betaine structure 30b can strongly coordinate to the surface of the nanoparticle 10 (luminescent nanocrystal). Further, since the shell-like ligand 20 has a plurality of betaine structures 30b in the same molecule, even if some coordination is detached from the surface of the nanoparticle 10 due to some stimulus, it can be easily coordinated again. Furthermore, the polymer chain included in the organic polymer part 40 exhibits a protective function as a shell for the core of the nanoparticle 10, making the nanoparticle 10 less susceptible to the influence of substances such as polar solvents. Therefore, it is considered that the stability of the structure and composition of the nanoparticle 10, which is a luminescent nanocrystal, is improved, and the stability of the luminescence characteristics is improved. In the present specification, the bond between the bonding part 30 and the nanoparticle 10 corresponds to an ionic bond due to electrostatic interaction. In some cases, it may be paraphrased that the bond between the bonding part 30 and the nanoparticle 10 is distinguished from a covalent bond and corresponds to a non-covalent bond. The betaine structure 30b is shown at the branched ends of a pair of sites polarized positively and negatively within the molecule as shown in FIGS. 1(a) to (c) and FIG. 2, with the intention of clarifying the bond due to electrostatic interaction. The pair of sites polarized positively and negatively within the betaine structure 30b corresponds to the polarized regions located in the linear structures corresponding to any of the polarized sites in the structural units represented by formulas (1) to (3).

[0038] The shell-like ligand 20 of the present embodiment has at least a portion coordinated to the nanoparticle 10. The shell-like ligand 20 of the present embodiment is coordinated such that the organic polymer part 40 covers the outer periphery of the nanoparticle 10. As described in the modified form of the present embodiment to be described later, the shell-like ligand 20 does not necessarily completely cover the outer periphery of the nanoparticle 10, that is, the coverage rate does not need to be 100%, and a form having a portion where the organic polymer parts 40 are not locally connected is also included.

[0039] From the perspective of the stability of the nanoparticles 10 in a polar solvent, the number average molecular weight of the shell-like ligand 40 is preferably 1,000 or more and 50,000 or less. Similarly, the number average molecular weight of the shell-like ligand 20 is more preferably 2,000 or more and 30,000 or less. When the proportion of the organic polymer part 30 in the shell-like ligand 20 is dominant over the proportion of the bonding part 30 in the shell-like ligand 20, the number average molecular weight of the organic polymer part 40 may be used as a substitute for the number average molecular weight of the shell-like ligand 20.

[0040] (Bonding part) The bonding part 30 included in the shell-like ligand 20 includes a betaine structure 30b related to the bonding with the nanoparticles 10 and a connecting part 30j including a bond 33 on the side opposite to the betaine structure 30b, as shown in FIG. 1(b). The bond 33 is a part related to the bonding with the organic polymer part 40 and corresponds to the bond 43 included in the organic polymer part 40 shown in FIG. 1(c).

[0041] Furthermore, the bonding part 30 includes an organic group 30a in the connecting part 30j. The organic group 30a is compatible with a polymerizable compound (not shown) present in the medium and is responsible for the dispersion stability in the medium of the nanoparticles 10 coordinated with the shell-like ligand 20.

[0042] In the present embodiment, the bonding part 30 included in the shell-like ligand 20 has a structural unit represented by at least one of the formulas (1) to (3).

[0043] [Chemical formula]

[0044] [Chemical formula]

[0045] [Chemical formula]

[0046] Here, in formulas (1) to (3), R1 to R5, R 13 ~R 15 each independently represents either a hydrogen atom or an alkyl group, N represents a nitrogen atom, A1 to A5 represent linking groups, Y - represents a COO - group or a SO3 - group, and "*" represents a bond to the organic polymer part. In this embodiment, the shell-like ligand 20 is preferably a copolymer having a bonding part 30 represented by formulas (1) to (3).

[0047] R1 to R3 in formula (1), R4, R5 in formula (2), and R 13 ~R 15 The alkyl group in is preferably an alkyl group having 1 to 18 carbon atoms. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an n-octyl group, a 2-ethylhexyl group, a dodecyl group, and an octadecyl group can be mentioned. These alkyl groups may be further substituted and may be bonded to each other to form a ring.

[0048] In formula (1), A1 is a linking group that binds the polymer main chain and the phosphate ester moiety. The linking group A1 represents any of a carbonyl group, an alkylene group, an arylene group, and -COOR 20 -(provided that the carbonyl group in -COOR 20 -binds to other than the phosphate ester moiety, and R 20 represents an alkylene having 1 to 4 carbon atoms). Further, the betaine structure 30b may be directly bonded to the polymer main chain provided by the organic polymer part 40 by a single bond.

[0049] The alkylene group in the linking group A1 may be either linear or branched, and an alkylene group having 1 to 4 carbon atoms is preferred. Examples of the alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propylene group, and various butylene groups.

[0050] Examples of the arylene group in the linking group A1 include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group.

[0051] -COOR in the linking group A1 20 - is -COOR 20 - The carbonyl group in - binds to a site other than the phosphate ester site, and R 20 is an alkylene having 1 to 4 carbon atoms. The alkylene may be either linear or branched.

[0052] These linking groups A1 may be further substituted with other functional groups.

[0053] From the viewpoints of availability of raw materials and ease of production, the linking group A1 is more preferably a carbonyl group or -COOR 20 -.

[0054] In formula (1), A2 is a linking group that binds the phosphate ester site and the quaternary ammonium site, and represents either an alkylene group or an arylene group.

[0055] The alkylene group in the linking group A2 may be either linear or branched, and is preferably an alkylene group having 1 to 4 carbon atoms.

[0056] Examples include a methylene group, an ethylene group, a propylene group, and various butylene groups.

[0057] Examples of the arylene group in the linking group A2 include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group.

[0058] These linking groups may be further substituted.

[0059] The linking group A2 is more preferably a simple alkylene group such as a methylene group or an ethylene group from the viewpoints of availability of raw materials and ease of production.

[0060] In formula (2), A3 is a linking group that binds the polymer main chain and the quaternary ammonium moiety. The linking group A3 is an alkylene group, an arylene group, an aralkylene group, a -COOR 21 -b, a-CONHR 21 -b, or a-OR 21 -b, etc. Here, a represents the bonding site with the part other than the quaternary ammonium moiety, b represents the bonding site with the quaternary ammonium moiety, and R 21 represents an alkylene group or an arylene group. Also, the betaine moiety may be directly bonded to the polymer main chain by a single bond.

[0061] The alkylene group in the linking group A3 may be either linear or branched, and an alkylene group having 1 to 4 carbon atoms is preferred. For example, a methylene group, an ethylene group, a propylene group, various butylene groups, etc. can be mentioned.

[0062] Examples of the arylene group in the linking group A3 include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group, etc.

[0063] Examples of the aralkylene group in the linking group A3 include an aralkylene group having 7 to 15 carbon atoms.

[0064] When the linking group A3 is a-COOR 21 -b, a-CONHR 21 -b, or a-OR 21 -b, R 21The alkylene group in [description] may be either linear or branched, and an alkylene group having 1 to 4 carbon atoms is preferred. For example, a methylene group, an ethylene group, a propylene group, various butylene groups, etc. may be mentioned. Here, a represents the bonding site with other than the quaternary ammonium site, b represents the bonding site with the quaternary ammonium site, and R7 represents an alkylene group or an arylene group.

[0065] Also, R 21 Examples of the arylene group in [description] include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group.

[0066] The linking group A3 may be further substituted.

[0067] From the viewpoint of availability of raw materials and ease of production, the linking group A3 is more preferably a-COOR 21 -b, or a-CONHR 21 -b.

[0068] In formula (2), A4 is a linking group that binds the quaternary ammonium site and its counter anion part Y - , and examples thereof include an alkylene group or an arylene group.

[0069] In formula (3), A5 is a linking group that binds the polymer main chain and the betaine site. The linking group A5 is an alkylene group, an arylene group, an aralkylen group, a-COOR 22 -b, a-CONHR 22 -b, or a-OR 22 -b, etc. However, a represents the bonding site with other than the betaine site, b represents the bonding site with the betaine site, and R 22 represents an alkylene group or an arylene group. Also, the betaine part may be directly connected to the polymer main chain by a single bond.

[0070] As the alkylene group in the linking group A4, it may be either linear or branched, and an alkylene group having 1 to 4 carbon atoms is preferred.

[0071] For example, a methylene group, an ethylene group, a propylene group, various butylene groups, etc. can be mentioned.

[0072] As the arylene group in the linking group A2, a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, a naphthalene-2,6-diyl group, etc. can be mentioned.

[0073] The linking group A4 may be further substituted.

[0074] The linking group A4 is not particularly limited as described above, but from the viewpoints of availability of raw materials and ease of production, a simple alkylene group such as a methylene group, an ethylene group or a propylene group is more preferable.

[0075] In formula (3), Y - is the counter anion of the quaternary ammonium moiety and is covalently bonded to the quaternary ammonium moiety via the linking group A4. Y - is a COO - group or a SO3 - group.

[0076] (Polymer part) The polymer part 40 included in the shell-like ligand 20 constitutes a shell structure that extends linearly or branchedly as shown in Fig. 1(d), and such a polymer chain has a bond 43. The bond 43 is a part related to the bond with the bonding part 30 and corresponds to the bond 33 included in the bonding part 30 shown in Fig. 1(c).

[0077] The organic polymer part 40 may have a plurality of bonds 33. The organic polymer part 40 overlaps with another adjacent organic polymer part 40, intertwines with each other, and forms a network of organic polymers that constitutes the shell-like ligand 20.

[0078] The discontinuity 40d shown in Fig. 1(b) may have a plurality of forms including a slit type extending linearly or branchedly in the gap between adjacent organic polymers 40 and an independent opening type corresponding to the network of organic polymer chains constituting the shell structure.

[0079] The shell-like ligand 20 is preferably a copolymer having both a polymer part 40 having a structural unit represented by the formula (6) and a bonding part 30.

[0080]

Chemical formula

[0081] Here, in the formula (6), R 16 represents either a hydrogen atom or an alkyl group, and R17 represents any one of an alkyl group, a carboxylic acid ester group, a carboxylic acid amide group, an alkoxy group, and an aryl group.

[0082] In the formula (6), R 16 The alkyl group in is preferably an alkyl group having 1 to 4 carbon atoms. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group can be mentioned. In the formula (6), R 16 is preferably a hydrogen atom or a methyl group from the viewpoint of the production (polymerizability) of the copolymer.

[0083] In the formula (6), R 17 The alkyl group in is preferably an alkyl group having 1 to 30 carbon atoms. For example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-hexyl group, an n-decyl group, an n-hexadecyl group, an octadecyl group, a docosyl group, and a triacontyl group can be mentioned.

[0084] In the formula (6), R 17 Examples of the aryl group in include aryl groups such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0085] In the formula (6), R17 Examples of the carboxylic acid ester group in [it] include -COOR 24 wherein R 24 represents any one of an alkyl group having 1 to 30 carbon atoms, a phenyl group, and a hydroxyalkyl group having 1 to 30 carbon atoms. Examples of the carboxylic acid ester group in R 17 include a methyl ester group, an ethyl ester group, an n-propyl ester group, an isopropyl ester group, an n-butyl ester group, a tert-butyl ester group, an octyl ester group, a 2-ethylhexyl ester group, a dodecyl ester group, an octadecyl ester group, a docosyl ester group, a triacontyl ester group, a phenyl ester group, and an ester group of a 2-hydroxyethyl ester group.

[0086] In formula (6), examples of the carboxamide group in R 17 include -CO-NR 25 R 26 wherein R 25 and R 26 each independently represent any one of hydrogen, an alkyl group having 1 to 30 carbon atoms, and a phenyl group. Examples of the carboxamide group in R 17 include amide groups such as an N-methylamide group, an N,N-dimethylamide group, an N,N-diethylamide group, an N-isopropylamide group, an N-tert-butylamide group, an N-n-decylamide group, an N-n-hexadecylamide group, an N-octadecylamide group, an N-docosylamide group, an N-triacontylamide group, and an N-phenylamide group.

[0087] In formula (6), examples of the alkoxyl group in R 17 include an alkoxy group having 1 to 30 carbon atoms or a hydroxyalkoxy group having 1 to 30 carbon atoms. R 17Examples of the alkoxyl group in [description] include alkoxyl groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, n-hexyloxy group, cyclohexyloxy group, n-octyloxy group, 2-ethylhexyloxy group, dodecyloxy group, octadecyloxy group, docosyloxy group, triacontyloxy group, and 2-hydroxyethoxy group.

[0088] In formula (6), R 17 The substituent of [description] may be further substituted. In this case, examples of the substituent that may be substituted include alkoxyl groups such as methoxy group and ethoxy group, amino groups such as N-methylamino group and N,N-dimethylamino group, acyl groups such as acetyl group, and halogen atoms such as fluorine atom and chlorine atom.

[0089] In formula (6), R 16 and R 17 can be arbitrarily selected from the substituents listed above, but it is advisable to select an appropriate substituent according to the application. For example, when the above-mentioned photoreactive material is used in a highly hydrophobic medium, in order to improve the dispersibility and stability, it is preferable to select a substituent having a long-chain organic group.

[0090] In the present embodiment, it is preferable that the molar ratio of the structural unit represented by any one of formulas (1) to (3) to the structural unit represented by formula (6) in the above copolymer is 2.0 / 98 or more and 50 / 50 or less. Further, it is more preferable that such a molar ratio is 6 / 94 or more and 45 / 55 or less, and even more preferably 10 / 90 or more and 40 / 60 or less. When the copolymer composition ratio is within the above range, the coordination of the shell-like ligand to the nanoparticles is stabilized, and the composition and crystal structure as the luminescent nanocrystal are stabilized.

[0091] The content of the shell-like ligand 20 in the photo-responsive material 100 is preferably 1 part by mass to 1000 parts by mass, preferably 5 parts by mass to 500 parts by mass, more preferably 10 parts by mass to 300 parts by mass, with the content of the luminescent nanocrystal being 100 parts by mass. When it is less than 1 part by mass, the effect as a shell may not be fully exerted, and the stability may not be improved. When it is more than 1000 parts by mass, the solubility and dispersibility of the shell-like ligand in the medium may decrease, and the stability of the photo-responsive material may not be improved. The content of the shell-like ligand 20 in the photo-responsive material 100 may be appropriately adjusted according to the types and uses of the nanoparticles 10 and the shell-like ligand 20.

[0092] In this embodiment, the content of the shell-like ligand 20 is determined by performing TG-DTA measurement on a mixture containing the nanoparticles 10 and the shell-like ligand 20. A mixture (not shown) composed of the nanoparticles 10 and the shell-like ligand 20 can be obtained by adding a poor solvent of the above mixture to the ink composition, sedimenting the above mixture by centrifugation, and then drying it. Further, when the nanoparticles 10 contain an organic component, the content of the organic component is separately measured and subtracted from the ratio of the ink composition 100, whereby the content of the shell-like ligand 20 can be determined. Note that the case where the A site of the perovskite-type quantum dot is an organic compound is included in the case where the nanoparticles 10 contain an organic component.

[0093] Examples of the method for coordinating the shell-like ligand 20 on the surface of the nanoparticles 10 include a method in which the shell-like ligand 20 is allowed to act after the synthesis of the nanoparticles 10 and exchanged with the ligand described below, and a method in which the shell-like ligand 20 is allowed to coexist during the synthesis of the nanoparticles 10 to effect coordination. When the shell-like ligand 20 is coordinated by exchanging with the ligand as described above, excess free ligand can be removed by centrifugation.

[0094] In this embodiment, the number of mmol of the betaine group per 1 g of the luminescent nanocrystal is preferably from 0.01 to 10, more preferably from 0.03 to 8, and still more preferably from 0.1 to 6. When the number of mmol of the betaine group per 1 g of the luminescent nanocrystal is within the above range, the coordination to the luminescent nanocrystal is strongly carried out, so that the stability is improved. When it is less than 0.02, the effect as a shell may not be sufficiently exhibited, and the stability may not be improved. When it is greater than 10, the solubility and dispersibility of the shell-like ligand in the medium may decrease, and the stability of the photoreactive material may not be improved. Also, the viscosity may increase. The number of mmol corresponds to the content of the betaine group contained per 1 g of the luminescent nanocrystal and is a unit corresponding to ×10 -3 mol.

[0095] Hereinafter, the production method of the above shell-like ligand and copolymer (hereinafter, also collectively referred to as the shell-like ligand) will be described in detail.

[0096] The production method of the shell-like ligand is not particularly limited as long as the one having the above structure can be obtained. For example, the shell-like ligand can be produced by the following methods (i) and (ii).

[0097] That is, (i) the shell-like ligand can be produced by a method of polymerizing a monomer containing at least a structure corresponding to any of formulas (1) to (3) after producing the monomer. Further, (ii) the shell-like ligand can be produced by a method of bonding an amphoteric ion site corresponding to any of formulas (1) to (3) to such a polymer main chain by a polymer reaction after synthesizing the polymer main chain.

[0098] From the viewpoint of easy availability of the monomer and control of the amount of functional groups, it is preferably produced by the method shown in (i). Hereinafter, the method for synthesizing the shell-like ligand 20 having the structural unit represented by formula (1) using the method shown in (i) will be described in detail.

[0099] Monomers for introducing the structural unit represented by formula (1) into the shell ligand 20 include vinyl ether derivatives, acrylate derivatives, methacrylate derivatives, α-olefin derivatives, aromatic vinyl derivatives, etc., depending on the structure of the linking group A1. Among these monomers, acrylate derivatives or methacrylate derivatives are preferably employed from the viewpoint of ease of monomer production.

[0100] The corresponding acrylate derivative or methacrylate derivative can be produced by the methods described in the following literature, etc. K. Ishihara, et al., "Polymer Journal", (Japan), The Society of Polymer Science, 1990, Vol. 22, p. 355-360.

[0101] Examples of the polymerization method of the above monomers include radical polymerization and ionic polymerization, and living polymerization for the purpose of controlling the molecular weight distribution and structure can also be used. Industrially, it is preferable to use radical polymerization.

[0102] Radical polymerization can be carried out by the use of a radical polymerization initiator, irradiation with light such as radiation or laser light, combined use of a photoinitiator and light irradiation, heating, etc. The above radical polymerization initiator may be any compound that can generate radicals and initiate the polymerization reaction, and is selected from compounds that generate radicals by the action of heat, light, radiation, redox reaction, etc.

[0103] Examples of radical polymerization initiators include azo compounds, organic peroxides, inorganic peroxides, organometallic compounds, photoinitiators, etc.

[0104] More specifically, the radical polymerization initiators include azo compounds such as 2,2'-azobisisobutyronitrile (AIBN) and 2,2'-azobis(2,4-dimethylvaleronitrile), organic peroxides such as benzoyl peroxide (BPO), tert-butyl peroxypivalate, and tert-butyl peroxyisopropyl carbonate, inorganic peroxides such as potassium persulfate and ammonium persulfate, redox initiators such as hydrogen peroxide-iron(II) salt system, BPO-dimethylaniline system, and cerium(IV) salt-alcohol system, and photopolymerization initiators such as acetophenone system, benzoin ether system, and ketal system. These radical polymerization initiators may be used in combination of two or more kinds.

[0105] The polymerization temperature of the monomer varies depending on the type of polymerization initiator used, and there is no particular limitation. However, it is generally polymerized at a temperature of -30°C to 150°C, and a more preferable temperature range is 40°C to 120°C.

[0106] The amount of the polymerization initiator used at this time is preferably adjusted to be 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the above monomer so that a shell-like ligand having a target molecular weight distribution can be obtained.

[0107] Also, as the polymerization method, any method such as solution polymerization, suspension polymerization, emulsion polymerization, dispersion polymerization, precipitation polymerization, and bulk polymerization can be used, and there is no particular limitation.

[0108] The obtained shell-like ligand can be purified as needed. There is no particular limitation on the purification method, and methods such as reprecipitation, dialysis, and column chromatography can be used.

[0109] The method for producing the above copolymer is not particularly limited as long as the one having the above structure is obtained, and is the same as the above shell-like ligand.

[0110] At this time, in addition to the monomer containing the structural unit corresponding to at least any one of Formula (1) to Formula (3) and the monomer corresponding to Formula (6), it is also possible to further add a polymerizable monomer and perform polymerization.

[0111] (Polymerizable compound) The polymerizable compound can receive the supply of energy such as light, heat, and electromagnetic waves, polymerize itself, impart viscosity to a liquid or paste-like intermediate, and be cured.

[0112] In order to make the photo-responsive material 100 of the present embodiment a photo-responsive composition that cures in response to an external stimulus, a polymerizable monomer can also be used as a medium. The polymerizable monomer includes ultraviolet curable UV monomers, UV dimers, UV oligomers, thermally polymerizable monomers, thermally polymerizable dimers, thermally polymerizable oligomers, etc., and may be equivalently referred to as a photo-polymerizable compound and a thermally polymerizable compound, respectively.

[0113] <Modification of the First Embodiment> Note that the photo-responsive material 100 of the first embodiment has a form in which the entire surface of the nanoparticles 10 (corresponding to a solid angle of 4π) is covered with the shell-like ligand 20 as shown in Fig. 1(a). However, the form in which the shell-like ligand 20 does not necessarily cover the entire nanoparticles 10 is also included in the aspect of the present invention. Fig. 1(b) shows a schematic cross-section of the photo-responsive material 120 corresponding to the modification of the first embodiment. The photo-responsive material 120 according to this modification is different from the photo-responsive material 100 of the first embodiment in that it includes a shell-like ligand 20 that does not cover a part of the nanoparticles 10. In the photo-responsive material 120 of this modification, the organic polymer part 40 binds to the nanoparticles 10 at a plurality of locations via a plurality of binding parts 30, so that the shell-like ligand 20 is coordinated to the nanoparticles 10.

[0114] The shell-like ligand 20 of this modification has at least a part that is coordinated to the nanoparticles 10 in the same manner as the shell-like ligand 20 of the first embodiment. The part that does not cover a part of the nanoparticles 10 in the shell-like ligand 20 corresponds to the discontinuous part 40u.

[0115] (Non-shell ligand) The photosensitive material 100 of this embodiment may have a non-shell ligand bonded to the surface of a core containing semiconductor nanoparticles having a perovskite crystal structure. The non-shell ligand may further improve the stability such as dispersion stability and spectral characteristics in some cases. The non-shell ligand may contain at least one compound or ion selected from the group consisting of acids such as carboxylic acid, sulfonic acid, and phosphonic acid, bases such as ammonia and amine, betaine groups, and salts or ions thereof. From the viewpoint of dispersion stability, it is preferable to use at least one compound or ion selected from the group consisting of organic acids, organic bases, and salts or ions thereof, and betaine groups among these non-shell ligands.

[0116] Examples of the organic acid include branched or linear fatty acids having 1 to 30 carbon atoms. The fatty acid may be either saturated or unsaturated. Among them, from the viewpoints of solubility and stability in a solvent, linear fatty acids are preferable, and oleic acid is more preferable.

[0117] The salt component in the organic acid salt is not particularly limited as long as it is a metal cation. The salt component in the organic acid salt is preferably an alkali metal cation or an alkaline earth metal cation, and more preferably an alkali metal cation. Among the alkali metal cations, sodium and potassium are preferable, and sodium is more preferable.

[0118] Examples of the organic base include branched or linear organic bases having 1 to 30 carbon atoms. The organic base may be either saturated or unsaturated. Among them, from the viewpoints of solubility and stability in a solvent, linear organic bases are preferable, and oleylamine is more preferable.

[0119] From the viewpoints of solubility and stability in a solvent containing a compound selected from the group consisting of phosphobetaine groups, sulfobetaine groups, and carboxybetaine groups, a compound having a phosphobetaine group or a sulfobetaine group is preferable for the betaine group.

[0120] The non-shell ligands may be used alone or in combination of two or more.

[0121] (Polymerization initiator) In the polymerization reaction, generally, a polymerization initiator and a polymerizable compound are used in combination. The polymerization initiator is a compound that generates active species for initiating the polymerization reaction by irradiation with active energy rays or heat, and known polymerization initiators can be used. The main active species for initiating the polymerization reaction include radical polymerization initiators that generate radicals and cationic polymerization initiators that generate acids, and these may be used in combination. Examples of photo radical polymerization initiators that generate radicals by active energy rays include acetophenones such as diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl methyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butane, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methylpropan-1-one; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; phosphines such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; and other phenylglyoxylic acid methyl esters.

[0122] Among the photo radical polymerization initiators, preferably, acetophenones represented by aminoketones, phosphines, and oxime ester compounds are used. These can be used alone or in combination of two or more according to the properties required for the cured product. When using a radical polymerization initiator, the amount used is preferably 0.01 to 100 parts by mass, more preferably 0.1 to 50 parts by mass, based on 100 parts by mass of the total solid content in the composition.

[0123] (Polymerizable compound) The polymerizable compound is a component that promotes polymerization upon receiving energy such as light and heat, and imparts viscosity to the photo-responsive composition and causes it to cure. As the polymerizable compound, a radical polymerizable compound or a cationic polymerizable compound can be used. These can be used alone or in combination of two or more. Also, either a photo-polymerizable compound or a thermo-polymerizable compound can be used.

[0124] Examples of the radical polymerizable compound include monofunctional (meth)acrylate compounds, difunctional (meth)acrylate compounds, trifunctional or higher (meth)acrylate compounds, hydroxyl group-containing (meth)acrylate compounds, carboxyl group-containing (meth)acrylate compounds, vinyl compounds, and the like.

[0125] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, benzyl (meth)acrylate, 3,3,5-trimethylcyclohexyl acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, isobornyl (meth)acrylate, methoxy triethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxetane-3-yl)methyl (meth)acrylate, and cyclic trimethylolpropane formal (meth)acrylate can be used.

[0126] Examples of the bifunctional (meth)acrylate compounds include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 300 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, polypropylene glycol 700 di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol PO-modified di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, PO-modified bisphenol A di(meth)acrylate, and neopentyl glycol hydroxypivalate di(meth)acrylate.

[0127] Examples of the trifunctional or higher-functional (meth)acrylate compounds include trimethylolpropane triacrylate, trimethylolpropane EO-modified tri(meth)acrylate, trimethylolpropane PO-modified tri(meth)acrylate, glycerin propoxytri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, and EO-modified pentaerythritol tetraacrylate.

[0128] Examples of the salicylic acid group-containing (meth)acrylate compounds include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; 2-hydroxyethyl acryloyl phosphate; 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate; caprolactone-modified 2-hydroxyethyl (meth)acrylate; dipropylene glycol (meth)acrylate; fatty acid-modified glycidyl (meth)acrylate; polyethylene glycol mono (meth)acrylate; polypropylene glycol mono (meth)acrylate; 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate; glycerin di (meth)acrylate; and 2-hydroxy-3-acryloyl-oxypropyl methacrylate.

[0129] Examples of the carboxy group-containing (meth)acrylate compounds include β-carboxyethyl (meth)acrylate, succinic acid mono (meth)acryloyloxyethyl ester, and ω-carboxypolycaprolactone mono (meth)acrylate.

[0130] Examples of the vinyl compounds include vinyl acetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl methacrylate, and N-vinylpyrrolidone.

[0131] As the cationic polymerizable compounds, either a photopolymerization type or a thermal polymerization type can be used. These may be used alone or in combination of two or more. Representative cationic polymerizable compounds include, for example, epoxy compounds, oxetane compounds, and vinyl ether compounds.

[0132] The amount of the polymerizable compound containing the above radical polymerizable compound and cationic polymerizable compound is preferably 1 to 99 parts by mass, more preferably 5 to 95 parts by mass, and still more preferably 10 to 90 parts by mass with respect to 100 parts by mass of the ink composition.

[0133] (Solvent) The polymerizable compound may contain a solvent as needed. As the solvent, for example, alkanes such as pentane and hexane, cycloalkanes such as cyclopentane and cyclohexane, esters such as ethyl acetate, butyl acetate, and benzyl acetate, ethers such as diethyl ether and tetrahydrofuran, ketones such as cyclohexanone and acetone, and alcohols such as methanol, ethanol, isopropanol, butanol, and hexanol can be used. In addition, monoacetate compounds such as diethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether acetate, diacetate compounds such as 1,4-butanediol diacetate and propylene glycol diacetate, and triacetate compounds such as glyceryl triacetate can also be used.

[0134] Since it is easy to remove the solvent before the curing of the polymerizable compound 50, a boiling point of 300°C or lower is adopted for the solvent. The solvent may be paraphrased as a solvent.

[0135] (Other additives) In the present embodiment, the ink composition may be mixed with an oxygen scavenger, an antioxidant, a scattering agent such as titanium oxide, a surfactant, an antifungal agent, a light stabilizer, and other additives that impart various properties, a diluting solvent, etc. as needed and used.

[0136] (Wavelength conversion member) The wavelength conversion member of this embodiment is a member obtained by curing a photoreactive composition 200 (ink composition 200) containing a photoreactive material 100 in a co-dispersed state and a polymerizable compound 50 shown in Fig. 3(a) on a substrate. Since the wavelength conversion member takes the form of a layer supported by another member, it may be referred to as a wavelength conversion layer 520 as described in Fig. 4(b). The support forms include a laminated form and a dispersed form dispersed in a matrix material. The wavelength conversion layer 520 can be obtained by coating the photoreactive composition 200 on a support member (substrate) and curing it to form a film, sheet, or patterned pixel.

[0137] (Method for forming wavelength conversion layer) The method for forming the wavelength conversion layer 520 is not particularly limited. For example, after coating a photoreactive composition on a substrate, pre-drying may be performed as necessary, and further, heat treatment or active energy ray irradiation may be performed as necessary to cure the film. The thickness of the wavelength conversion layer after curing is preferably 0.1 to 200 μm, more preferably 1 to 100 μm.

[0138] The active energy rays in the active energy ray irradiation are appropriately selected from electromagnetic waves such as heat rays, ultraviolet rays, visible light, near-infrared rays, and electron beams that reduce fluidity and promote curing by polymerization, crosslinking, drying, etc. As the light source for applying the active energy rays, a light source having a main emission wavelength in the wavelength range of 100 to 450 nm is preferred. Examples of such light sources include ultra-high pressure mercury lamps, high pressure mercury lamps, medium pressure mercury lamps, mercury xenon lamps, metal halide lamps, high power metal halide lamps, xenon lamps, pulsed xenon lamps, deuterium lamps, fluorescent lamps, ND-YAG triple wavelength lasers, HE-CD lasers, nitrogen lasers, XE-Cl excimer lasers, XE-F excimer lasers, semiconductor-excited solid-state lasers, and LED lamp light sources having emission wavelengths of 365 nm, 375 nm, 385 nm, 395 nm, and 405 nm.

[0139] <Second Embodiment> Fig. 3(a) is a diagram showing the dispersed state of the photoreactive composition 200 according to the second embodiment.

[0140] The photoreactive composition 200 changes in viscosity and cures by the polymerization of the polymerizable compound it contains. Therefore, the photoreactive composition 200 in Fig. 3(a) corresponding to the stage before curing may be referred to as the ink composition 200 because it is in the form of an ink with fluidity. Curing may be paraphrased as solidifying. The luminescent material 200 includes a photoreactive material 100 and a polymerizable compound 50. The luminescent material 200 is in a state where the photoreactive material 100 and the polymerizable compound 50 are co-dispersed in the solvent 90.

[0141] The photoreactive composition 200 of this embodiment has a form in which the entire sphere of the nanoparticles 10 (corresponding to 4π in solid angle) is covered by the shell-like ligand 20 as shown in Fig. 3(a). In the photoreactive composition 200 of this embodiment, the organic group 40a compatible with the polymerizable compound 50 contained in the medium is a part of the structure included in the organic polymer part 40.

[0142] The shell-like ligand 20 of this modified form has at least a portion coordinated to the nanoparticles 10. The shell-like ligand 20 in the photoreactive composition 200 has a discontinuous portion (not shown) that does not cover a part of the nanoparticles 10. The discontinuous portion (not shown) that does not cover a part of the nanoparticles 10 includes a network-like pore formed by the overlapping of linear organic polymer parts 40 extending in different directions along the shell of the shell-like ligand 20.

[0143] A form in which an organic group is provided as a part of the structure of the bonding part is also included as a modified form of this embodiment. In such a modified form (not shown), the organic group protrudes outward from the shell-like ligand through the mesh of the network structure constituted by the polymer part.

[0144] The photoreactive composition 200 constitutes a film-like wavelength conversion part 526 when the polymerizable compound 50 is cured by polymerization.

[0145] <Third Embodiment> Fig. 3(b) shows the cross-sectional structure of the display element 500 according to the third embodiment.

[0146] It is shown that in the stacking direction D1 of the display element 500, a light emitting layer 510, a dielectric multilayer film 517, and a wavelength conversion layer 520 are stacked. The downstream side in the stacking direction D1 coincides with the side where the user who views the image drawn on the display element is located. The wavelength conversion layer 520 is separated from the wavelength conversion layers corresponding to adjacent elements by a black matrix BM that separates pixels.

[0147] As described above, the photo-responsive composition 200 is cured together with the polymerizable compound 50 by performing a polymerization process such as a photopolymerization process. By being cured, the photo-responsive composition 200 constitutes the wavelength conversion layer 520 of the display element 500 that satisfies a predetermined dimension. That is, the wavelength conversion layer 520 is a layer solidified by being cured together with the polymerizable compound 50.

[0148] The light emitting layer 510 corresponds to a light source that emits light L1 having a first wavelength λ1. The wavelength conversion layer 520 has an optical coupling surface 522 that is optically coupled to the light emitting layer 510 on the side of the light emitting layer 510, and an extraction surface 524 that extracts the secondary light L2 converted by the wavelength conversion layer 520 on the side opposite to the light emitting layer 510.

[0149] The wavelength conversion layer 520 of the present embodiment receives the primary light L1 having a wavelength λ1 that propagates through the dielectric multilayer film 917. The dielectric multilayer film 517 provides the display element 500 with the spectral transmission characteristics of the primary light from the light emitting layer 510 and the spectral reflection characteristics of the secondary light L2 having a wavelength λ2 that is emitted from the wavelength conversion layer 520. The wavelength λ2 of the secondary light L2 is longer than the wavelength λ1 of the primary light L1.

[0150] The dielectric multilayer film 917 can be replaced with another optical member that has light transmissibility with respect to the first wavelength λ1 emitted by the light emitting layer 510. Also, other optical members (not shown) can be arranged in front of the extraction surface 524 (on the side opposite to the light emitting layer 510).

[0151] <First Reference Embodiment> FIG. 2 shows the dispersibility of the photo-responsive material 800 according to the first reference embodiment in the solvent 90. The photo-responsive material 800 according to this reference embodiment has a betaine structure 30b, but does not have a shell-like ligand 20, and only a non-shell-like ligand 60 extending substantially radially from the surface of the nanoparticles 10 with a linear skeleton or a branched skeleton is coordinated to the surface of the luminescent nanoparticles 10. That is, the photo-responsive material 800 according to this reference embodiment has a betaine structure 30b which is a structure that exhibits zwitterionic properties, but does not have a shell-like ligand 20, and in other words, only the non-shell-like ligand 60 is coordinated to the surface of the luminescent nanoparticles 10. The non-shell-like ligand 60 included in the photo-responsive material 800 according to this reference embodiment has a betaine structure 30b, but does not include an organic polymer 20 which is a shell-like ligand 20, that is, surrounds the nanoparticles 10 in a shell-like manner and is coordinated in parallel at a plurality of locations via a plurality of bonding portions 30.

[0152] Therefore, the bonding of the ligand coordinated to the nanoparticles 10 in the photo-responsive material 800 according to this reference embodiment is not as strong as that in the photo-responsive material 100 according to the first embodiment. As a result, the luminescent nanoparticles 10 included in the photo-responsive material 800 according to this reference embodiment are likely to be attacked by the solvent 90 containing polar molecules, and it is presumed that the semiconductor composition changes or defects occur in the perovskite crystal structure at a part of the surface of the nanoparticles 10.

[0153] ((Storage method)) Since the luminescent nanoparticles having a perovskite crystal structure are likely to have their luminescence characteristics deteriorated not only by polar solvents but also by light and heat, it is preferable to store the photo-responsive materials 100 and 200 according to this embodiment in a refrigerator with external light shielded or in a dark room. By doing so, it is possible to reduce the deterioration due to light and heat during the storage of the photo-responsive materials 100 and 200 according to this embodiment.

[0154] ((Measurement method)) Various physical property measurements can be performed as follows.

[0155] ((Molecular weight distribution measurement)) The molecular weight distribution of the shell-shaped ligand can be calculated in terms of monodisperse polymethyl methacrylate by gel permeation chromatography (GPC). The measurement of the molecular weight by GPC can be carried out, for example, as shown below.

[0156] The sample was added to the following eluent so that the sample concentration became 1% by mass, and the solution allowed to stand at room temperature for 24 hours to dissolve was filtered through a solvent-resistant membrane filter with a pore size of 0.45 μm, and the resulting solution was used as the sample solution and measured under the following conditions. Apparatus: Agilent 1260 infinity system (manufactured by Agilent Technologies) Column: PFG analytical linear M columns (manufactured by PSS) Eluent: 2,2,2-trifluoroethanol Flow rate: 0.2 ml / min Oven temperature: 40 °C Sample injection volume: 20 μL

[0157] In calculating the molecular weight distribution of the sample, a molecular weight calibration curve prepared using a standard polymethyl methacrylate resin (EasiVial PM Polymer Standard Kit manufactured by Agilent Technologies) is used.

[0158] ((Composition analysis)) The composition analysis of the shell-shaped ligand can be carried out using nuclear magnetic resonance (NMR). For example, using a JEOL ECA-600 (600 MHz), 1H-NMR and 13C-NMR spectral measurements are performed. At that time, the measurement is carried out at 25 °C in a deuterated solvent containing tetramethylsilane as an internal standard substance. The chemical shift value is read as the ppm shift value (δ value) with tetramethylsilane, which is the internal standard substance, set to 0.

[0159] ((Crystal structure analysis)) The crystal structure analysis and composition analysis of the nanoparticles 10 can be carried out using X-ray photoelectron spectroscopy (XPS). For example, the crystal structure can be analyzed by measuring the X-ray diffraction pattern using RINT 2100 (manufactured by Rigaku).

[0160] ((Composition analysis)) The composition analysis of the nanoparticles 10 can be carried out using XPS and ICP emission spectroscopy. The molar ratio of A and B can be measured from the signal intensity of XPS, and the concentration of X can be measured from the emission intensity of ICP emission spectroscopy (for example, CIROS CCD (manufactured by SPECTRO)).

[0161] ((Method for confirming the coordination of ligands to nanoparticles)) Confirmation of whether or not the shell-like ligand 20 is coordinated to the nanoparticles 10 can be carried out using infrared spectroscopy (IR). To a dispersion containing the nanoparticles 10 and the shell-like ligand 20, a poor solvent is added as necessary, and after precipitation by centrifugation, the supernatant is removed and the precipitate is dried. The shell-like ligand 20 not bound to the nanoparticles 10 is removed together with the supernatant. If the IR absorption spectrum of the obtained solid is measured and a signal at the bonding part is observed, it can be confirmed that the shell-like ligand 20 is coordinated to the nanoparticles 10. At this time, the signal at the bonding part may shift by about several nm due to coordination.

[0162] In addition, coordination can also be confirmed by transmission electron microscope (TEM) observation. Usually, photo-responsive nanoparticles having a perovskite crystal structure are observed in a regularly arranged form, but when a shell-like ligand is coordinated, the arrangement is observed to be disordered due to steric repulsion between the shell-like ligands and steric repulsion between the shell-like ligand and the substrate. Coordination can also be confirmed from this.

[0163] ((Content of photo-responsive nanoparticles)) The content of the photo-responsive nanoparticles in the photo-responsive material and the photo-responsive composition can be measured using ICP emission spectrometry and NMR. For example, the amount of Pb is measured from the emission intensity of ICP emission spectrometry, and the amount of the ligand is measured from the signal intensity of NMR. The content of the photo-responsive nanoparticles can be measured from the compositional information of the photo-responsive nanoparticles obtained by the above method.

[0164] ((Content of the polymer compound)) In addition to the above TG-DTA measurement, the content of the polymer compound in the photo-responsive material and the photo-responsive composition can also be determined from the integrated intensity of NMR.

[0165] ((Content of the betaine group in the polymer compound)) The content of the betaine group in the polymer compound can be determined from the integrated intensity ratio of NMR between the betaine part and other parts in the polymer compound.

[0166] ((mmol number of the betaine group per 1 g of the photo-responsive nanoparticles)) The mmol number of the betaine group per 1 g of the photo-responsive nanoparticles can be calculated from the content of the photo-responsive nanoparticles obtained by the above method, the content of the polymer compound, and the content of the betaine group in the polymer compound.

[0167] <The Fourth Embodiment> The photo-responsive material 140 of this embodiment is different from the photo-responsive material 100 of the first embodiment in that the structural unit exhibiting zwitterionic properties provided with a plurality of bonding parts 30 is a quaternary ammonium salt.

[0168] (Shell-like ligand) As shown in Fig. 4(a), the photo-responsive material 140 according to this embodiment includes nanoparticles 10 having a perovskite crystal structure and shell-like ligands 20 that bind to the surface of the nanoparticles 10 at a plurality of locations. The shell-like ligand 20 includes a plurality of bonding parts 30 and an organic polymer part 40 that binds to the nanoparticles 10 at a plurality of locations via the plurality of bonding parts 30.

[0169] As shown in FIG. 4(c), the coupling part 30 includes a quaternary ammonium salt 30b related to the coupling with the nanoparticles and a connecting part 30j including a bond 33 at the end related to the coupling with the organic polymer part 40. The quaternary ammonium salt 30b refers to a salt of a cation in which ammonia molecules are tetra-substituted by substituents containing carbon and another anion.

[0170] The shell-like ligand 20 having a structural unit containing the quaternary ammonium salt 30b can strongly coordinate to the surface of the nanoparticles 10. The quaternary ammonium salt 30b has a positive charge and a negative charge at non-adjacent positions within the same molecule, and corresponds to one of the structural units exhibiting zwitterionic properties without having a charge as a whole molecule. Therefore, it can be said that the shell-like ligand 20 of the present embodiment is a ligand having a plurality of structural units exhibiting zwitterionic properties, a plurality of coupling parts, and a polymer part 40 coordinated to the photoreactive nanoparticles 10 via the plurality of coupling parts 30. In addition, since the shell-like ligand 20 has a plurality of quaternary ammonium salts 30b in the same molecule, even if some of the bonds are detached from the surface of the nanoparticles 10 due to some stimulus, they can be easily re-bonded. Furthermore, the polymer chain included in the organic polymer part 40 exhibits a protective function as a shell for the core of the nanoparticles 10, making the nanoparticles 10 less susceptible to the influence of substances such as polar solvents. Therefore, it is considered that the stability of the structure and composition of the nanoparticles 10 is improved, and the stability of the photoreactivity is improved. The zwitterionic structure is another way of saying that it is one form of the form exhibiting ionic properties in a part of the structural unit.

[0171] The shell-like ligand 20 of the present embodiment has at least a portion that binds to the nanoparticle 10. The shell-like ligand 20 is bound such that the organic polymer portion 40 covers the outer periphery of the nanoparticle 10. As will be described later, the shell-like ligand 20 does not necessarily completely cover the outer periphery of the nanoparticle 10, that is, it is not necessary to have a coating rate of 100%. As shown in Fig. 4(d), a form having a portion where the organic polymer portions 40 are not locally connected is also included. That is, it can be said that the shell-like ligand 20 also includes a coordination form having a portion where the organic polymer portions 40 are not locally connected. The organic polymer portion 40 has a plurality of binding hands 43 that bind to the nanoparticle 10 via the binding portion 30. In addition, the organic polymer portion 40 may have an organic group 40a in its side chain. The organic group 40a exhibits the dispersibility of the photoreactive material 140 in the medium 90.

[0172] From the viewpoint of the stability of the nanoparticle 10 in a polar solvent, the weight average molecular weight of the shell-like ligand 20 is preferably 1,000 or more and 100,000 or less. Similarly, it is more preferable that the weight average molecular weight of the shell-like ligand 20 is 2,000 or more and 50,000 or less. When the ratio of the organic polymer portion 40 in the shell-like ligand 20 is dominant over the ratio of the binding portion 30 in the shell-like ligand 20, the weight average molecular weight of the organic polymer portion 40 may be substituted for the weight average molecular weight of the shell-like ligand 20.

[0173] As shown in Fig. 4(a), since the shell-like ligand 20 is located between the perovskite-type nanoparticle 10 and the medium 90, the nanoparticle 10 is protected from the influence of the medium 90 on the nanoparticle 10 by the photoreactive material 140.

[0174] (Binding portion) In the present embodiment, the binding portion 30 included in the shell-like ligand 20 has a structural unit represented by the formula (4).

[0175]

Chemical formula

[0176] Here, in formula (4), R6 to R8 each independently represent either an alkyl group or an aryl group, N represents a nitrogen atom, N represents a nitrogen atom, A6 represents a linking group, and X - is an anion, and "*" represents a bond to the polymer part.

[0177] In this embodiment, it is preferable that the shell-like ligand 20 is a copolymer having a bonding part 30 represented by formula (4).

[0178] In formula (4), A6 is a linking group that binds a polymer chain and a quaternary ammonium moiety, and is an alkylene group, an arylene group, an aralkylene group, a -COOR 23 -b, a -CONHR 23 -b, or a -OR 23 -b, etc. Here, a represents a bonding site with the organic polymer part, b represents a bonding site with the quaternary ammonium moiety, and R 23 represents an alkylene group or an arylene group.

[0179] The alkylene group in the linking group A6 may be either linear or branched, and an alkylene group having 1 to 4 carbon atoms is preferable. For example, a methylene group, an ethylene group, a propylene group, a butylene group, etc. may be mentioned.

[0180] Examples of the arylene group in the linking group A6 include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group.

[0181] Examples of the aralkylene group in the linking group A6 include an aralkylene group having 7 to 15 carbon atoms.

[0182] When the linking group A6 is a -COOR 23 -b, a -CONHR 23 -b, or a -OR 23 -b, R 23The alkylene group in [description] may be either linear or branched, and an alkylene group having 1 to 4 carbon atoms is preferred. For example, a methylene group, an ethylene group, a propylene group, a butylene group, etc. may be mentioned. Here, a represents the bonding site with the organic polymer part, b represents the bonding site with the quaternary ammonium site, and R 23 represents an alkylene group or an arylene group.

[0183] Also, as for the arylene group in R 23 , for example, a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, and a naphthalene-2,6-diyl group, etc. may be mentioned.

[0184] The linking group A6 may be further substituted, and the substitution is not particularly limited as long as it does not significantly reduce characteristics such as the photoreactivity and dispersion stability of the nanoparticles.

[0185] The linking group A6 is not particularly limited as described above, but from the viewpoints of availability of raw materials and ease of production, the case of a-COOR 23 -b is more preferable.

[0186] The bonding part 30 provided in the shell-like ligand 20 may have a structure bonded to the polymer main chain via the linking group A7 as represented by the formula (5).

[0187] Here, in the formula (5), R9 to R 11 each independently represents either an alkyl group or an aryl group, R 12 represents either a hydrogen atom or an alkyl group, N represents a nitrogen atom, A7 represents a linking group, and X - represents an anion.

[0188]

Chemical formula

[0189] In the formula (5), R 12As the organic group in [this context], an alkyl group having 1 to 4 carbon atoms is preferable. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, etc. can be mentioned. R9 in formula (5) can be arbitrarily selected from the substituents listed above and a hydrogen atom, but from the viewpoint of the production (polymerizability) of the polymer compound, a hydrogen atom and a methyl group are preferable cases.

[0190] The shell-like ligand 20 of the present embodiment is preferably a copolymer having a structural unit represented by formula (6) as the organic polymer part 40 and a bonding part 30, in the same manner as the shell-like ligand of the first embodiment.

[0191]

Chemical formula

[0192] In formula (4) or formula (5), X - represents an anion.

[0193] X - Examples of [X] include halogen ions such as chloride ion, bromide ion, iodide ion, fluoride ion, anions containing COO ― or SO3 ― in the structure, monovalent anions such as BF4 - , PF6 ― , ClO4 ― , N3 - , etc.

[0194] Examples of the anion having the above COO - group include acetate anion, propionate anion, benzoate anion, etc.

[0195] Examples of the anion containing SO3 ― in X- include methanesulfonate anion, trifluoromethanesulfonate anion, benzenesulfonate anion, p-toluenesulfonate anion, methyl sulfate anion, etc.

[0196] X - may be used alone or in combination of two or more.

[0197] In this embodiment, the molar ratio of the structural unit represented by the formula (4) or (5) to the structural unit represented by the formula (6) in the copolymer is preferably 0.01:99.99 to 50:50, more preferably 1:99 to 30:70. When the copolymerization composition ratio is within the above range, the binding to the nanoparticles is strongly performed, so that the stability as a photoreactive material is improved.

[0198] The content of the shell-like ligand 20 in the photoreactive material 140 is preferably 1 part by mass to 1000 parts by mass, preferably 5 parts by mass to 500 parts by mass, more preferably 10 parts by mass to 300 parts by mass, with the content of the photoreactive nanocrystal being 100 parts by mass. When it is less than 1 part by mass, the effect as a shell may not be sufficiently exerted, and the stability may not be improved. When it is more than 1000 parts by mass, the solubility and dispersibility of the shell-like ligand in the medium may decrease, and the stability of the photoreactive material may not be improved. The content of the shell-like ligand 20 in the photoreactive material 140 may be appropriately adjusted according to the types and uses of the nanoparticles 10 and the shell-like ligand 20.

[0199] The content of the shell-like ligand 20 in this embodiment is determined by performing TG-DTA measurement on a mixture containing the nanoparticles 10 and the shell-like ligand 20. A mixture (not shown) composed of the nanoparticles 10 and the shell-like ligand 20 can be obtained by adding a poor solvent to the mixture containing the nanoparticles, sedimenting the mixture composed of the nanoparticles 10 and the shell-like ligand 20 by centrifugation, and then drying.

[0200] Methods for coordinating the shell-like ligand 20 to the surface of the nanoparticles 10 include a method of allowing the shell-like ligand 20 to act after the synthesis of the nanoparticles 10 and exchanging it with the non-shell-like ligand described below, and a method of binding by coexisting the shell-like ligand 20 during the synthesis of the nanoparticles 10. When the shell-like ligand 20 is bound by exchanging with the non-shell-like ligand as described above, excess free ligand can be removed by centrifugation.

[0201] The manufacturing method of the above shell-like ligand and copolymer (hereinafter also collectively referred to as shell-like ligand) will be described in detail below.

[0202] The manufacturing method of the shell-like ligand is not particularly limited as long as the structure of the above is obtained, but it can be manufactured by, for example, the following method.

[0203] That is, the shell-like ligand 20 can be manufactured by a method of polymerizing a monomer containing a structural unit corresponding to formula (4) or formula (5) after manufacturing the monomer. Further, the shell-like ligand 20 can be manufactured by a method of binding or generating a quaternary ammonium salt by a polymer reaction after synthesizing the shell-like ligand 20 having a polymer main chain.

[0204] It is preferably manufactured by the method shown in (i) from the viewpoint of easy availability of the monomer and control of the amount of functional groups. Hereinafter, a method for synthesizing the shell-like ligand 20 having the structural unit represented by formula (5) using the method shown in (i) will be described in detail.

[0205] As the monomer for introducing the structural unit represented by formula (5) into the shell-like ligand, depending on the structure of the linking group A, vinyl ether derivatives, acrylate derivatives, methacrylate derivatives, α-olefin derivatives, aromatic vinyl derivatives, etc. can be used. However, from the viewpoint of easy manufacture of the monomer, it is preferable to use an acrylate derivative or a methacrylate derivative as the monomer for introducing the structural unit represented by formula (5) into the shell-like ligand.

[0206] The corresponding acrylate derivative or methacrylate derivative can be produced by the method described in the following literature or the like. K. Ishihara, et al., "Polymer Journal", (Japan), The Society of Polymer Science, 1990, Vol. 22, p. 355-360.

[0207] Examples of the polymerization method of the above monomers include radical polymerization and ionic polymerization, and living polymerization for the purpose of controlling the molecular weight distribution and structure can also be used. Industrially, it is preferable to use radical polymerization.

[0208] Radical polymerization can be carried out by using a radical polymerization initiator, irradiation with light such as radiation or laser light, combined use of a photoinitiator and light irradiation, heating, etc. The above radical polymerization initiator may be any compound that can generate radicals and initiate a polymerization reaction, and is selected from compounds that generate radicals by the action of heat, light, radiation, redox reaction, etc.

[0209] Examples of radical polymerization initiators include azo compounds, organic peroxides, inorganic peroxides, organometallic compounds, photoinitiators, etc.

[0210] More specifically, radical polymerization initiators include azo compounds such as 2,2'-azobisisobutyronitrile (AIBN) and 2,2'-azobis(2,4-dimethylvaleronitrile), organic peroxides such as benzoyl peroxide (BPO), tert-butyl peroxy pivalate, and tert-butyl peroxy isopropyl carbonate, inorganic peroxides such as potassium persulfate and ammonium persulfate, redox initiators such as hydrogen peroxide-iron(II) salt system, BPO-dimethylaniline system, and cerium(IV) salt-alcohol system, and photoinitiators such as acetophenone system, benzoin ether system, and ketal system. These radical polymerization initiators may be used in combination of two or more.

[0211] The polymerization temperature of the monomer varies depending on the type of polymerization initiator used and is not particularly limited. However, it is generally polymerized at a temperature of -30°C to 150°C, and a more preferable temperature range is 40°C to 120°C.

[0212] The amount of the polymerization initiator used at this time is preferably adjusted to be 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the above monomer so as to obtain a shell-like ligand with a target molecular weight distribution.

[0213] Also, as the polymerization method, any method such as solution polymerization, suspension polymerization, emulsion polymerization, dispersion polymerization, precipitation polymerization, and bulk polymerization can be used, and it is not particularly limited.

[0214] The obtained shell-like ligand can be purified as needed. There is no particular limitation on the purification method, and methods such as reprecipitation, dialysis, and column chromatography can be used.

[0215] The method for producing the above copolymer is also not particularly limited as long as the one having the above structure is obtained, and it is the same as the above shell-like ligand.

[0216] For example, a method of producing the monomer corresponding to formula (5) and the monomer corresponding to formula (6) and then polymerizing them can be mentioned.

[0217] At this time, it is also possible to further add and polymerize polymerizable monomers other than the monomer corresponding to formula (5) and the monomer corresponding to formula (6).

[0218] <Modification of the Fourth Embodiment> Note that the photo-responsive material 140 of the fourth embodiment has a form in which the entire surface of the nanoparticles 10 is covered by the shell-like ligand 20 as shown in FIG. 4(a). However, the form in which the shell-like ligand 20 does not necessarily cover the entire surface of the nanoparticles 10 is also included in the aspect of the present invention. The entire surface corresponds to 4π in solid angle. FIG. 4(b) shows a schematic cross-section of the photo-responsive material 1600 corresponding to a modified form of the fourth embodiment. The photo-responsive material 160 according to this modified form is different from the photo-responsive material 100 of the fourth embodiment in that it includes a shell-like ligand 25 that does not cover a part of the nanoparticles 10. In the photo-responsive material 160 of this modified form, the organic polymer part 45 binds to the nanoparticles 10 at a plurality of locations via a plurality of binding parts 30, so that the shell-like ligand 25 is coordinated to the nanoparticles 10.

[0219] Similar to the shell-like ligand 20, the shell-like ligand 25 of this modified form has at least a portion coordinated to the nanoparticles 10.

[0220] <Second Reference Form> FIG. 5 shows the dispersibility of the photo-responsive material 850 according to the second reference form in the medium 90. The photo-responsive material 850 according to this reference form includes an ammonium salt 30b, but does not have a shell-like ligand 20. A non-shell-like ligand 60 extending substantially radially from the surface of the luminescent nanoparticles 10 with a linear skeleton or a branched skeleton is coordinated to the surface of the nanoparticles 10. That is, it can be said that the photo-responsive material 850 according to this reference form includes an ammonium salt 30b having a structure that exhibits zwitterionic properties, but does not have a shell-like ligand 20, and only the non-shell-like ligand 60 is coordinated to the surface of the luminescent nanoparticles 10. The non-shell-like ligand 60 included in the photo-responsive material 850 according to this reference form includes an ammonium salt 30b, but does not include an organic polymer 40 that has a shell-like ligand 20, that is, surrounds the nanoparticles 10 in a shell-like manner and is coordinated in parallel at a plurality of locations via a plurality of binding parts 30.

[0221] Therefore, compared with the photosensitive material 140 according to the fourth embodiment, the ligand bonded to the nanoparticles 10 in the photosensitive material 850 according to this reference embodiment is not strongly bonded. As a result, the nanoparticles 10 included in the photosensitive material 850 according to this reference embodiment are likely to be attacked by the medium 90 containing polar molecules, and it is presumed that the semiconductor composition changes or defects occur in the perovskite crystal structure on a part of the surface of the nanoparticles 10.

[0222] <Fifth Embodiment> Next, the ink composition 330 (photosensitive composition 330) according to the fifth embodiment will be described with reference to FIGS. 6(a), 6(b), and 6(c).

[0223] In addition, in order to make the photosensitive materials 140 and 160 of the fifth embodiment and its modified forms into an ink composition that cures in response to an external stimulus, the polymerizable compound 50 can be dispersed or dissolved in the medium 90. The polymerizable compound 50 includes ultraviolet curable UV monomers, UV dimers, UV oligomers, etc., and may be equivalently referred to as a photopolymerizable compound.

[0224] (Shell-like ligand) As shown in FIG. 6(a), the ink composition 330 according to this embodiment includes photosensitive nanoparticles 10 and shell-like ligands 20 that coordinate by binding to the surface of the nanoparticles 10 at a plurality of locations. The shell-like ligand 20 includes a plurality of bonding portions 30 containing a quaternary ammonium salt 30b and an organic polymer portion 40 that binds to the nanoparticles 10 at a plurality of locations via the plurality of bonding portions 30.

[0225] Here, the quaternary ammonium salt 30b refers to a salt of a cation in which ammonia molecules are tetra-substituted by substituents containing carbon and another anion. As shown in FIG. 6(b), the bonding portion 30 includes a quaternary ammonium salt 30b related to the bonding with the nanoparticle 10 and a connecting portion 30j including a bond 33 at the end related to the bonding with the organic polymer portion 40. Further, at least one of the bonding portion 30 and the organic polymer portion 40 has organic groups 30a and 40a as shown in FIGS. 6(a) to 6(c). The organic group 30a extends to the outside of the shell through the discontinuous portion 40d of the organic polymer portion 40 constituting the shell-like ligand 20. The portion where the organic polymer portions 40 are not connected is shown as the discontinuous portion 40d in FIG. 4(b). The discontinuous portion 40d includes both a form extending in a network or linear form to the shell-like ligand 20 and a form discretely existing as independent holes opened in a part of the organic polymer portion 40 spreading two-dimensionally.

[0226] The ink composition 330 shown in FIG. 6(a) is stably dispersed in a medium containing a medium 90 and a polymerizable compound 50 by the organic groups 30a and 40a of the shell-like ligand 20 coordinated so as to cover the nanoparticles 10. The inventor of the present application presumes that this is an effect brought about by the fact that the organic groups 30a and 40a have an appropriate affinity (miscibility) with the polymerizable compound 50 in the medium and are compatible. In the present specification, the bonding between the bonding portion 30 and the nanoparticle 10 corresponds to an ionic bond due to electrostatic interaction. In other words, the bonding between the bonding portion 30 and the nanoparticle 10 may be regarded as a non-covalent bond, which is distinguished from a covalent bond.

[0227] The organic groups 30a and 40a extend to the outside of the shell-like organic polymer portion 40, which is presumed to be caused by the difference in polarity between the organic groups 30a and 40a and the quaternary ammonium salt 30b. Specifically, the bonding portion 30 is coordinated to the nanoparticle 10 by the quaternary ammonium salt 30b having a strong polarity, and the relatively low-polarity organic groups 30a and 40a extend substantially radially toward the medium side where the medium 90 and the polymerizable compound 50 are present.

[0228] Since the organic groups 30a and 40a extending from the shell-like ligand 20 are compatible with the polymerizable compound 50 in the medium, aggregation of the nanoparticles 10 is less likely to occur. Also, since the organic groups 30a and 40a extending from the shell-like ligand 20 are compatible with the polymerizable compound 50 in the medium, the nanoparticles 10 are protected by the shell-like ligand 20 even when in a state close to polar molecules and the polymerizable compound 50 in the medium 90. That is, as shown in Fig. 6(a), the organic groups 30a and 40a are such that the photo-responsive nanoparticles 10 with the shell-like ligand 20 coordinated around them are dispersed in the medium 90 and are protected by the shell-like ligand 20 from the medium 90 and the polymerizable compound described later. The nanoparticles 10 may also be protected from attacks by dispersed components and dissolved components (not shown) dispersed or dissolved in the medium 90.

[0229] The shell-like ligand 20 having a structural unit containing the quaternary ammonium salt 30b can strongly coordinate to the surface of the nanoparticles 10 (luminescent nanocrystals). Also, since the shell-like ligand 20 has a plurality of quaternary ammonium salts 30b in the same molecule, even if some of the coordination is detached from the surface of the nanoparticles 10 due to some stimulus, it can easily coordinate again. Furthermore, the polymer chains included in the organic polymer part 40 exhibit a protective function as a shell against the core of the nanoparticles 10, making the nanoparticles 10 less susceptible to the influence of substances such as polar solvents. Therefore, it is considered that the stability of the structure and composition of the nanoparticles 10, which are luminescent nanocrystals, is improved, and the stability of the luminescence characteristics is improved.

[0230] (Polymerizable compound) As shown in Fig. 6, the ink composition 330 contains the polymerizable compound 50. The polymerizable compound 50 is a component that is promoted to polymerize upon receiving energy such as light and heat, and imparts viscosity to the ink composition and causes it to cure. As the polymerizable compound 50, a radical polymerizable compound or a cationic polymerizable compound can be used. These may be used alone or in combination of two or more. Also, either a photopolymerizable compound or a thermopolymerizable compound can be used.

[0231] For any of the polymerization compound 50, polymerization accelerator, solvent, and other additives, those compliant with the ink composition 330 (photo-responsive composition) according to the second embodiment can be adopted.

[0232] Regarding the storage methods and measurement methods listed below, the methods common to the first embodiment and the second embodiment are also adopted in the fourth embodiment and the fifth embodiment.

[0233] As the radical polymerizable compound, for example, monofunctional (meth)acrylate compounds, difunctional (meth)acrylate compounds, trifunctional or higher (meth)acrylate compounds, hydroxyl group-containing (meth)acrylate compounds, carboxyl group-containing (meth)acrylate compounds, vinyl compounds, etc. can be used.

[0234] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, benzyl (meth)acrylate, 3,3,5-trimethylcyclohexyl acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, isobornyl (meth)acrylate, methoxy triethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate.

[0235] Examples of the bifunctional (meth)acrylate compounds include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 300 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, polypropylene glycol 700 di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol PO-modified di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, PO-modified bisphenol A di(meth)acrylate, and neopentyl glycol hydroxypivalate di(meth)acrylate.

[0236] Examples of the trifunctional or higher functional (meth)acrylate compounds include trimethylolpropane triacrylate, trimethylolpropane EO-modified tri(meth)acrylate, trimethylolpropane PO-modified tri(meth)acrylate, glycerin propoxytri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, and EO-modified pentaerythritol tetraacrylate.

[0237] Examples of the salicylic acid group-containing (meth)acrylate compounds include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; 2-hydroxyethyl acryloyl phosphate; 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate; caprolactone-modified 2-hydroxyethyl (meth)acrylate; dipropylene glycol (meth)acrylate; fatty acid-modified glycidyl (meth)acrylate; polyethylene glycol mono (meth)acrylate; polypropylene glycol mono (meth)acrylate; 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate; glycerin di (meth)acrylate; and 2-hydroxy-3-acryloyl-oxypropyl methacrylate.

[0238] Examples of the carboxy group-containing (meth)acrylate compounds include β-carboxyethyl (meth)acrylate, succinic acid mono (meth)acryloyloxyethyl ester, and ω-carboxypolycaprolactone mono (meth)acrylate.

[0239] Examples of the vinyl compounds include vinyl acetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl methacrylate, and N-vinylpyrrolidone.

[0240] As the cationic polymerizable compounds, either a photopolymerization type or a thermal polymerization type can be used. These may be used alone or in combination of two or more. Representative cationic polymerizable compounds include, for example, epoxy compounds, oxetane compounds, and vinyl ether compounds.

[0241] The amount of the polymerizable compound containing the above radical polymerizable compound and cationic polymerizable compound is preferably 1 to 99 parts by mass, more preferably 3 to 90 parts by mass, still more preferably 5 to 80 parts by mass with respect to 100 parts by mass of the ink composition 300.

[0242] (Solvent) The ink composition 300 may contain a solvent as a component of the medium, if necessary. As the solvent, for example, alkanes such as pentane and hexane, cycloalkanes such as cyclopentane and cyclohexane, esters such as ethyl acetate, butyl acetate and benzyl acetate, ethers such as diethyl ether and tetrahydrofuran, ketones such as cyclohexanone and acetone, and alcohols such as methanol, ethanol, isopropanol, butanol and hexanol can be used. In addition, monoacetate compounds such as diethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate and dipropylene glycol methyl ether acetate, diacetate compounds such as 1,4-butanediol diacetate and propylene glycol diacetate, and triacetate compounds such as glyceryl triacetate can also be used.

[0243] Since it is easy to remove the solvent before curing the polymerizable compound, a boiling point of 300 ° C or lower is adopted for the solvent. The solvent may be referred to as a solvent.

[0244] (Other additives) In the present embodiment, the ink composition may be mixed with a polymerization initiator, an oxygen scavenger, an antioxidant, a scattering agent such as titanium oxide, a surfactant, a fungicide, a light stabilizer and other additives imparting various characteristics, a diluting solvent, etc. and used as needed.

[0245] (Measurement method) Molecular weight distribution measurement, composition analysis, crystal structure analysis, method for confirming that a ligand is coordinated to nanoparticles, content of photo-responsive nanoparticles, content of polymer compounds, mmol number of betaine groups per 1 g of photo-responsive nanoparticles

[0246] (Analysis of Anion Species Contained in Quaternary Ammonium Salt) In addition, the analysis of the anion species contained in the quaternary ammonium salt can be performed using combustion decomposition-ion chromatography. The sample is burned under a stream of oxygen-containing gas, the generated gas is repaired, and the generated ions are separated and quantified by ion chromatography to analyze the anion species. For example, an automatic sample combustion device AQF-2100 (manufactured by Mitsubishi Analytic) and an ion chromatograph IC-2010 (manufactured by Tosoh) can be used.

[0247] <Sixth Embodiment> The photosensitive material 180 of the present embodiment is different from the photosensitive materials 100, 120, 140, and 160 according to the first to sixth embodiments in that it has an organosilicon polymer part 44 instead of the organic polymer part 40. The photosensitive materials 100 to 180 according to the first to sixth embodiments including the present embodiment are common in that they have shell-like polymer parts 40 and 44 bonded to the photosensitive nanoparticles 10 at a plurality of locations via a plurality of bonding parts 30 having zwitterionic structural units.

[0248] (Organosilicon Polymer Part) The organosilicon polymer part 44 provided in the shell-like ligand 20 includes polymer chains that form a shell structure extending linearly or branchedly as shown in FIG. 7(d). Such polymer chains have bonds 43. The bond 43 is a part related to the bond with the bonding part 30 and corresponds to the bond 33 provided in the bonding part 30 shown in FIG. 7(c). The shell-like ligand 20 having the organosilicon polymer part 44, and the organosilicon polymer part 44 may be referred to as a silica shell 44.

[0249] The organosilicon polymer part 44 may have a plurality of bonds 33. The organosilicon polymer parts 44 overlap with other adjacent organosilicon polymer parts 44 to entangle with each other and form a network of organic polymers constituting the shell-like ligand 20.

[0250] The discontinuity 44u shown in Fig. 7(b) may have a plurality of forms including a slit type extending linearly or branchedly in a gap between adjacent organosilicon polymer parts 44 and an independent opening type corresponding to a network of organic polymer chains constituting a shell structure.

[0251] The organosilicon polymer part 44 contains a polysiloxane compound in which Si-O- is linked in the main chain. Further, the organosilicon polymer part 44 may adopt a copolymer having a structural unit represented by at least one of Formula (4) and Formula (5), and preferably includes a copolymer having a structural unit represented by Formula (4) and Formula (5). The organosilicon polymer part 44 may be paraphrased as a polysiloxane compound part 44 and an organosilicon compound part 44.

[0252]

Chemical formula

[0253] Here, in Formula (7), R 18 represents either a hydrogen atom or an alkyl group, and B represents a bond to the bonding part.

[0254]

Chemical formula

[0255] Here, in Formula (8), R 19 represents an alkyl group, and B represents a bond to the bonding part.

[0256] R 18 As the alkyl group in R, an alkyl group having 1 to 30 carbon atoms can be used, and an alkyl group having 1 to 4 carbon atoms is preferred. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group can be mentioned.

[0257] In Formula (7), R 18It can be arbitrarily selected from the substituents listed above and hydrogen atoms, and is preferably a methyl group or an ethyl group from the viewpoint of the production (polymerizability) of the copolymer.

[0258] Furthermore, Si-OR 18 The bond may be hydrolyzed to form a Si-O-Si bond. The Si-O-Si bond may be formed by an intermolecular condensation reaction or an intramolecular condensation reaction.

[0259] In formula (7), R 18 can be arbitrarily selected from the substituents listed above, and an appropriate substituent may be selected according to the application.

[0260] R 19 As the alkyl group in, an alkyl group having 1 to 30 carbon atoms can be used, and an alkyl group having 1 to 4 carbon atoms is preferable. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group can be mentioned.

[0261] For example, when the above light-responsive material is used in a highly hydrophobic medium, it is preferable to select a substituent having a long-chain alkyl chain in order to improve dispersibility and stability.

[0262] The copolymerization ratio of the shell-like ligand 20 corresponds to the ratio M30 / M44 of the total number of moles M30 of the bonding portion 30 containing the structural unit represented by any one of formulas (1) to (3) and the total number of moles M44 of the organosilicon polymer portion 44 containing the structural unit represented by formula (7) or formula (8). The copolymerization ratio of the shell-like ligand 20 is preferably 0.01 / 99.99 or more and 50 / 50 or less, and more preferably 1 / 99 or more and 30 / 70 or less. When the copolymerization composition ratio is within the above range, the coordination of the shell-like ligand 20 to the nanoparticles 10 is strongly performed, thereby improving the stability as the light-responsive material 100.

[0263] The content of the organosilicon polymer part 44 may be appropriately adjusted according to the types and uses of the nanoparticles 10 and the organosilicon polymer part 44, but it is preferably 0.01% by weight or more and 10% by weight or less based on the content of the nanoparticles 10. Further, the content of the organosilicon polymer part 44 is preferably 0.05% by weight or more and 5% by weight or less, and more preferably 0.1% by weight or more and 3% by weight or less. When the content of the organosilicon polymer part 44 is less than 0.01% by weight, the effect as a shell may not be sufficiently exhibited, and the dispersion stability of the nanoparticles 10 may not be maintained. When the content of the organosilicon polymer part 44 is more than 10% by weight, the solubility and dispersibility of the organosilicon polymer part in the medium may decrease, and the stability of the photoreactive material may not be improved.

[0264] The production method of the organosilicon polymer part 44 is not particularly limited, but it can be produced by, for example, the following methods.

[0265] The organosilicon polymer part 44 can be obtained by hydrolyzing betaine silane in which an alkylsilane main chain is linked to a betaine structure to form a Si-O-Si bond.

[0266] As a method for bonding the organosilicon polymer part 44 to the surface of the nanoparticles 10, there is a method in which a silane compound containing a betaine structure 30b (hereinafter referred to as a betaine silane compound) is coordinated after the synthesis of the nanoparticles 10, and then the organosilicon polymer part 44 is formed by hydrolysis. Further, as another method for bonding the organosilicon polymer part 44 to the surface of the nanoparticles 10, there is a method in which a silane compound containing a betaine structure 30b is coexisted during the synthesis of the nanoparticles 10 to bond them, and the organosilicon polymer part is formed by hydrolysis after purification.

[0267] As the betaine silane compound, a sulfobetaine silane compound in which the counter anion of the quaternary ammonium site is an SO3 - group, a carboxybetaine silane compound in which the counter anion is a COO - group, and a phosphobetaine silane compound in which the counter anion is an HPO3 - group can be used.

[0268] Sulfobetaine silane can be produced, for example, by the method described in the following literature etc. Langmuir 30.38(2014):11386-11393. The sulfobetaine silane compound can be obtained by reacting an aminoalkylsilane with sultone. As the aminoalkylsilane, when using [3-(N,N-dimethylamino)propyl]trimethoxysilane, it is preferable for forming a quaternary ammonium. Also, (N,N-dimethyl-3-aminopropyl)methyldimethoxysilane can be used. As the sultone, four-membered ring and five-membered ring sultones can be used. The number of carbon atoms of the alkylene group of the linking group A2 that binds the quaternary ammonium moiety and its counteranion moiety Y, or the linking group A4, is 3 when using a four-membered ring sultone and 4 when using a five-membered ring sultone. - The number of carbon atoms of the alkylene group of the linking group A2 or the linking group A4 that binds the quaternary ammonium moiety and its counteranion moiety Y is 3 when using a four-membered ring sultone and 4 when using a five-membered ring sultone.

[0269] The carboxybetaine silane compound can be produced, for example, by the method described in the following literature etc. RSC advances 6.30(2016):24827-24834.

[0270] The phosphobetaine silane compound can be produced, for example, by the method described in the following literature etc. ACS applied materials & interfaces 2.10(2010):2781-2788.

[0271] The structure of the produced organosilicon polymer part and the betaine silane compound that is its raw material can be identified using various instrumental analyses. As the analytical instruments that can be used, a nuclear magnetic resonance apparatus (NMR), gel permeation chromatography (GPC), inductively coupled plasma atomic emission spectrometer (ICP-AES), etc. can be used.

[0272] In order to make the photo-responsive material of this embodiment into a photo-responsive material composition that cures in response to an external stimulus, a polymerizable monomer can also be used as the medium.

[0273] <Modified form of the sixth embodiment> Note that the photosensitive material 180 of the sixth embodiment has a form in which the entire surface (corresponding to a solid angle of 4π) of the nanoparticles 10 is covered with the shell-like ligand 20 as shown in Fig. 7(a). However, a form in which the shell-like ligand 20 does not necessarily cover the entire nanoparticles 10 is also included in the aspect of the present invention. Fig. 7(b) shows a schematic cross-section of the photosensitive material 190 corresponding to the modified form of the first embodiment. The photosensitive material 190 according to this modified form is different from the photosensitive material 180 of the sixth embodiment in that it includes a shell-like ligand 20 that does not cover a part of the nanoparticles 10. In the photosensitive material 190 of this modified form, the organosilicon polymer part 44 binds to the nanoparticles 10 at a plurality of locations via a plurality of bonding parts 30, so that the shell-like ligand 20 is coordinated to the nanoparticles 10.

[0274] The shell-like ligand 20 of this modified form has at least a part that is coordinated to the nanoparticles 10 in the same manner as the shell-like ligand 20 of the first embodiment. The part that does not cover a part of the nanoparticles 10 in the shell-like ligand 20 corresponds to the discontinuous part 44u.

[0275] (Non-shell-like ligand) The photosensitive material 180 of this embodiment may have a non-shell-like ligand bonded to the surface of the core containing semiconductor nanoparticles having a perovskite crystal structure. In some cases, the stability such as dispersion stability and spectral characteristics can be further improved by the non-shell-like ligand. The non-shell-like ligand may include at least one compound or ion selected from the group consisting of acids such as carboxylic acid, sulfonic acid, and phosphonic acid, bases such as ammonia and amine, and salts or ions thereof. From the viewpoint of dispersion stability, it is preferable to use at least one compound or ion selected from the group consisting of organic acids, organic bases, and salts or ions thereof.

[0276] Examples of the organic acid include branched or linear fatty acids having 1 to 30 carbon atoms. The fatty acid may be either saturated or unsaturated. Among them, from the viewpoints of solubility and stability in the solvent, linear fatty acids are preferred, and oleic acid is more preferred.

[0277] The salt component in the organic acid salt is not particularly limited as long as it is a metal cation. The salt component in the organic acid salt is preferably an alkali metal cation or an alkaline earth metal cation, and more preferably an alkali metal cation. Among the alkali metal cations, sodium and potassium are preferred, and sodium is more preferred.

[0278] Examples of the organic base include branched or linear organic bases having 1 to 30 carbon atoms. The organic base may be either saturated or unsaturated. Among them, from the viewpoints of solubility and stability in the solvent, linear organic bases are preferred, and oleylamine is more preferred.

[0279] The non-shell-like ligands may be used alone or in combination of two or more.

[0280] (Polymerization initiator) In a polymerization reaction, generally, a polymerization initiator and a polymerizable compound are used in combination. As the polymerization initiator, it is a compound that generates active species that initiate the polymerization reaction by irradiation with active energy rays or heat, and it is possible to use a known polymerization initiator. The main active species that initiate the polymerization reaction include a radical polymerization initiator that generates radicals and a cationic polymerization initiator that generates an acid, and these may be used in combination. Examples of the photo radical polymerization initiator that generates radicals by active energy rays include, for example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl methyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butane, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methylpropan-1-one and other acetophenones; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether and other benzoins; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and other phosphines; and other phenylglyoxylic acid methyl esters.

[0281] Among the photo radical polymerization initiators, preferably, they are acetophenones represented by aminoketones, phosphines, and oxime ester compounds. These can be used alone or in combination of a plurality according to the properties required for the cured product. When using a radical polymerization initiator, the amount used is preferably 0.01 to 100 parts by mass, more preferably 0.1 to 50 parts by mass, based on 100 parts by mass of the total solid content in the composition.

[0282] (Polymerizable compound) The ink composition 200 contains a polymerizable compound 50. The polymerizable compound 50 is a component that is promoted to polymerize upon receiving energy such as light and heat, and imparts viscosity to the ink composition 200 and causes it to cure. As the polymerizable compound 50, a radical polymerizable compound or a cationic polymerizable compound can be used. These may be used alone or in combination of two or more. Also, either a photopolymerizable compound or a thermopolymerizable compound can be used.

[0283] As the radical polymerizable compound, for example, a monofunctional (meth)acrylate compound, a difunctional (meth)acrylate compound, a trifunctional or higher (meth)acrylate compound, a hydroxyl group-containing (meth)acrylate compound, a carboxyl group-containing (meth)acrylate compound, a vinyl compound, etc. can be used.

[0284] Examples of the monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, benzyl (meth)acrylate, 3,3,5-trimethylcyclohexyl acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, isobornyl (meth)acrylate, methoxy triethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxetane-3-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate.

[0285] Examples of the bifunctional (meth)acrylate compounds include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 300 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, polypropylene glycol 700 di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol PO-modified di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, PO-modified bisphenol A di(meth)acrylate, and neopentyl glycol hydroxypivalate di(meth)acrylate.

[0286] Examples of the trifunctional or higher functional (meth)acrylate compounds include trimethylolpropane triacrylate, trimethylolpropane EO-modified tri(meth)acrylate, trimethylolpropane PO-modified tri(meth)acrylate, glycerin propoxytri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, and EO-modified pentaerythritol tetraacrylate.

[0287] Examples of the hydroxyl group-containing (meth)acrylate compounds include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; 2-hydroxyethyl acryloyl phosphate; 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate; caprolactone-modified 2-hydroxyethyl (meth)acrylate; dipropylene glycol (meth)acrylate; fatty acid-modified glycidyl (meth)acrylate; polyethylene glycol mono(meth)acrylate; polypropylene glycol mono(meth)acrylate; 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate; glycerin di(meth)acrylate; and 2-hydroxy-3-acryloyl-oxypropyl methacrylate.

[0288] Examples of the carboxyl group-containing (meth)acrylate compounds include β-carboxyethyl (meth)acrylate, succinic acid mono(meth)acryloyloxyethyl ester, and ω-carboxypolycaprolactone mono(meth)acrylate.

[0289] Examples of the vinyl compounds include vinyl acetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl methacrylate, and N-vinylpyrrolidone.

[0290] As the cationic polymerizable compounds, either a photopolymerization type or a thermal polymerization type can be used. These can be used alone or in combination of two or more. Representative cationic polymerizable compounds include, for example, epoxy compounds, oxetane compounds, and vinyl ether compounds.

[0291] The amount of the polymerizable compound containing the above radical polymerizable compound and cationic polymerizable compound is preferably 1 to 99 parts by mass, more preferably 3 to 90 parts by mass, still more preferably 5 to 80 parts by mass with respect to 200 parts by mass of the ink composition.

[0292] (Solvent) The ink composition 200 may contain a solvent 90 as needed. As the solvent 90, for example, alkanes such as pentane and hexane, cycloalkanes such as cyclopentane and cyclohexane, esters such as ethyl acetate, butyl acetate, and benzyl acetate, ethers such as diethyl ether and tetrahydrofuran, ketones such as cyclohexanone and acetone, and alcohols such as methanol, ethanol, isopropanol, butanol, and hexanol can be used. In addition, monoacetate compounds such as diethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether acetate, diacetate compounds such as 1,4-butanediol diacetate and propylene glycol diacetate, and triacetate compounds such as glyceryl triacetate can also be used.

[0293] Since it is easy to remove the solvent before the curing of the polymerizable compound 50, a boiling point of 300 ° C or lower is adopted for the solvent 90. The solvent 90 may be paraphrased as the solvent 90.

[0294] (Other Additives) In this embodiment, the ink composition may be mixed with an oxygen scavenger, an antioxidant, a scattering agent such as titanium oxide, a surfactant, a fungicide, a light stabilizer, and other additives that impart various properties, a diluting solvent, etc. as needed and used.

[0295] (Wavelength Conversion Member) The wavelength conversion member of the present embodiment is a member obtained by curing a photoreactive composition 200 (ink composition 200) containing a photoreactive material 100 in a co-dispersed state shown in FIG. 3(a) and a polymerizable compound 50 on a substrate. Since the wavelength conversion member takes the form of a layer supported by another member, it may be referred to as a wavelength conversion layer 520 as described in FIG. 3(b). The support forms include a laminated form and a dispersed form dispersed in a matrix material. The wavelength conversion layer 520 can be obtained by coating and curing the photoreactive composition 200 on a support member (substrate) to form a film, sheet, or patterned pixel. Since the photoreactive composition 200 has fluidity at the stage before curing of the polymerizable compound 50, it may be referred to as the ink composition 200. Further, when the photoreactive material 100 contained in the photoreactive composition 200 is a material exhibiting luminescence, the photoreactive composition 200 may be referred to as a luminescent composition 200.

[0296] (Method for forming wavelength conversion layer) The method for forming the wavelength conversion layer 520 is not particularly limited. For example, after coating a photoreactive material composition on a substrate, pre-drying may be performed as necessary, and further, heat treatment or active energy ray irradiation may be performed as necessary to cure the film. The thickness of the wavelength conversion layer after curing is preferably 0.1 to 200 μm, more preferably 1 to 100 μm.

[0297] In active energy ray irradiation, the active energy ray refers to electromagnetic waves such as heat rays, ultraviolet rays, visible light rays, near-infrared rays, and electron beams, which are appropriately selected for polymerization, crosslinking, drying, etc. to reduce fluidity and promote curing. As a light source for imparting active energy rays, a light source having a main emission wavelength in the wavelength range of 100 to 450 nm is preferable. Examples of such light sources include ultra-high pressure mercury lamps, high pressure mercury lamps, medium pressure mercury lamps, mercury xenon lamps, metal halide lamps, high power metal halide lamps, xenon lamps, pulsed xenon lamps, deuterium lamps, fluorescent lamps, ND-YAG triple wavelength lasers, HE-CD lasers, nitrogen lasers, XE-Cl excimer lasers, XE-F excimer lasers, semiconductor-excited solid state lasers, and LED lamp light sources having emission wavelengths of 365 nm, 375 nm, 385 nm, 395 nm, and 405 nm.

[0298] <The Seventh Embodiment> FIG. 3(a) is a diagram showing the dispersed state of the photo-responsive composition 400 (ink composition 400) according to the seventh embodiment.

[0299] The photo-responsive composition 400 changes in viscosity and cures by the polymerization of the polymerizable compound contained therein. Therefore, the photo-responsive composition 400 in FIG. 3(a) corresponding to the stage before curing is in the form of an ink having fluidity and may be referred to as the ink composition 400. Curing may be paraphrased as solidification. The photo-responsive material 400 includes a photo-responsive material 180 and a polymerizable compound 50. The photo-responsive material 400 is in a state where the photo-responsive material 180 and the polymerizable compound 50 are co-dispersed in the solvent 90.

[0300] The photo-responsive composition 400 of the present embodiment takes the form in which the entire sphere (corresponding to 4π in solid angle) of the nanoparticles 10 is covered by the shell-like ligand 20 as shown in FIG. 9(a). In the photo-responsive composition 400 of the present embodiment, the alkyl chain 40a compatible with the polymerizable compound 50 contained in the medium is a part of the structure contained in the organosilicon polymer part 44.

[0301] The shell-like ligand 20 of this modified form has at least a portion coordinated to the nanoparticles 10. The shell-like ligand 20 in the photoresponsive composition 400 has a discontinuous portion (not shown) that does not cover a part of the nanoparticles 10. The discontinuous portion (not shown) that does not cover a part of the nanoparticles 10 includes a network-like pore formed by the overlapping of linear organosilicon polymer portions 44 extending in different directions along the shell of the shell-like ligand 20.

[0302] A form having an alkyl chain as a part of the structure of the bonding portion is also included as a modified form of this embodiment. In such a modified form (not shown), the alkyl chain protrudes outward from the shell-like ligand through the mesh of the network structure formed by the polymer portion.

[0303] The photoresponsive composition 400 constitutes a film-like wavelength conversion portion 526 when the polymerizable compound 50 is cured by polymerization.

[0304] <Eighth Embodiment> FIG. 9(b) shows a cross-sectional structure of the display element 500 according to the eighth embodiment.

[0305] In the display element 500, in the stacking direction D1, a light-emitting layer 510, a dielectric multilayer film 517, and a wavelength conversion layer 520 are stacked. The downstream side in the stacking direction D1 coincides with the side where the user who views the image drawn on the display element is located. The wavelength conversion layer 520 is separated from the wavelength conversion layers corresponding to adjacent elements by a black matrix BM that separates pixels.

[0306] As described above, the photoresponsive composition 200 is cured together with the polymerizable compound 50 by performing a polymerization treatment such as a photopolymerization treatment. The photoresponsive composition 200 is cured to form the wavelength conversion layer 520 of the display element 500 that satisfies a predetermined dimension. That is, the wavelength conversion layer 520 is a layer solidified by being cured together with the polymerizable compound 50.

[0307] The light-emitting layer 510 corresponds to a light source that emits light L1 having a first wavelength λ1. The wavelength conversion layer 520 has an optical coupling surface 522 that optically couples to the light-emitting layer 510 on the side of the light-emitting layer 510, and an extraction surface 524 that extracts the secondary light L2 converted by the wavelength conversion layer 520 on the side opposite to the light-emitting layer 510.

[0308] The wavelength conversion layer 520 of the present embodiment receives the primary light L1 having a wavelength λ1 that propagates through the dielectric multilayer film 917. The dielectric multilayer film 517 imparts to the display element 500 the spectral transmission characteristics of the primary light from the light-emitting layer 510 and the spectral reflection characteristics of the secondary light L2 having a wavelength λ2 that is emitted in the wavelength conversion layer 520. The wavelength λ2 of the secondary light L2 is longer than the wavelength λ1 of the primary light L1.

[0309] The dielectric multilayer film 917 can be replaced with another optical member having light transmissibility with respect to the first wavelength λ1 emitted by the light-emitting layer 510. Further, other optical members (not shown) can be arranged in front of the extraction surface 524 (on the side opposite to the light-emitting layer 510).

[0310] <Third Reference Embodiment> FIG. 8 shows the dispersibility of the light-responsive material 900 according to the third reference embodiment in the solvent 90. The light-responsive material 900 according to the reference embodiment includes a betaine structure 30b, but does not have a shell-like ligand 20, and only a non-shell-like ligand 60 that extends substantially radially from the surface of the nanoparticle 10 with a linear skeleton or a branched skeleton is coordinated to the surface of the luminescent nanoparticle 10. The non-shell-like ligand 60 included in the light-responsive material 900 according to the present reference embodiment includes a betaine structure 30b, but does not include a shell-like ligand 20, that is, an organic polymer 20 that surrounds the nanoparticle 10 in a shell-like manner and is coordinated in parallel at a plurality of locations through a plurality of bonding portions 30.

[0311] Therefore, in the photosensitive material 900 according to this reference embodiment, the bond of the ligand coordinated to the nanoparticles 10 is not as strong as that of the photosensitive material 100 according to Example 1. As a result, the luminescent nanoparticles 10 included in the photosensitive material 900 according to this reference embodiment are liable to be attacked by the solvent 90 containing polar molecules, and it is presumed that the semiconductor composition changes or defects occur in the perovskite crystal structure on a part of the surface of the nanoparticles 10.

[0312] Regarding any of the polymerizable compound 50, the polymerization accelerator, the solvent, and other additives, in the photosensitive composition 400 according to the seventh embodiment, those conforming to the ink composition 330 (photosensitive composition) according to the second embodiment can be adopted.

[0313] Regarding the storage method and measurement method listed below, the methods common to the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment are also adopted in the sixth embodiment and the seventh embodiment.

Examples

[0314] Hereinafter, the present disclosure will be described in more detail with reference to the first example group, but the present disclosure is not limited thereto.

[0315] [Production of Polymer Compound 1-a] A reaction vessel equipped with a condenser, a stirrer, a thermometer, and a nitrogen inlet tube was prepared. 17.9 parts of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate, 82.1 parts of octadecyl methacrylate, 4.1 parts of azobisisobutyronitrile, and 900 parts of n-butanol were charged into such a reaction vessel. Further, nitrogen bubbling was performed on such a reaction vessel for 30 minutes. The obtained reaction mixture was heated at 65° C. for 8 hours in a nitrogen atmosphere to complete the polymerization reaction. After the reaction solution was cooled to room temperature, the solvent was distilled off under reduced pressure. The obtained residue was dissolved in chloroform and purified by dialysis using a dialysis membrane (Spectra / Por7 MWCO 1 kDa manufactured by Spectrum Laboratories). After the solvent was distilled off under reduced pressure, the polymer compound 1-a was obtained by drying under reduced pressure at 50° C. and 0.1 kPa or less.

[0316] When the obtained polymer compound 1-a was analyzed by the above analysis method, it was confirmed that the weight average molecular weight (Mw) was 11,800 and the structural unit represented by the formula (2) was contained in 21 mol% in all monomer units. Note that the polymer compound 1-a may be paraphrased as the intermediate raw material a or the precursor a of the shell-like ligand 20 that coordinates to the particle surface of the nanoparticles 10 dispersed in the solvent 90.

[0317] [Production of Polymer Compound 1-b] 20.5 parts of 2-(methacryloyloxy)ethyl 2-(triethylammonio)ethyl phosphate was used instead of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate. Otherwise, the polymer compound 1-b was produced in the same manner as the production of the polymer compound 1-a.

[0318] [Production of Polymer Compound 1-c] 18.8 parts of 2-(methacryloyloxy)-1-methylethyl 2-(trimethylammonio)ethyl phosphate was used instead of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate. Otherwise, the polymer compound 1-c was produced in the same manner as the production of the polymer compound 1-a.

[0319] [Production of Polymer Compound 1-d] 19.6 parts of 2-(methacryloyloxy)ethyl 1,2-dimethyl-2-(trimethylammonio)ethyl phosphate was used instead of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate. Otherwise, the polymer compound 1-d was produced in the same manner as the production of the polymer compound 1-a.

[0320] [Production of Polymer Compound 1-e] The polymer compound 1-e was produced in the same manner as the production of the polymer compound 1-a, except that 78.7 parts of octadecyl acrylate was used instead of octadecyl methacrylate.

[0321] [Production of Polymer Compound 1-f] A polymer compound 1-f was produced in the same manner as the production of the polymer compound 1-a, except that 48.1 parts of octyl methacrylate was used instead of octadecyl methacrylate.

[0322] [Production of polymer compound 1-g] A polymer compound 1-g was produced in the same manner as the production of the polymer compound 1-a, except that 41.3 parts of hexyl methacrylate was used instead of octadecyl methacrylate.

[0323] [Production of polymer compound 1-h] A polymer compound 1-h was produced in the same manner as the production of the shell-like ligand 1-a, except that 34.5 parts of butyl methacrylate was used instead of octadecyl methacrylate.

[0324] [Production of polymer compound 1-i] 2-(Methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate was 1.8 parts and octadecyl methacrylate was 100.5 parts. Otherwise, a polymer compound 1-i was produced in the same manner as the production of the polymer compound 1-a.

[0325] [Production of polymer compound 1-j] 2-(Methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate was 4.5 parts and octadecyl methacrylate was 97.5 parts. Otherwise, a polymer compound 1-j was produced in the same manner as the production of the polymer compound 1-a.

[0326] [Production of polymer compound 1-k] A polymer compound 1-k was produced in the same manner as the production of the shell-like ligand 1-a, except that 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate was 9.8 parts and 45.9 parts of hexyl methacrylate was used instead of octadecyl methacrylate.

[0327] [Production of polymer compound 1-l] 2-(Methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate 332.2 parts, and hexyl methacrylate 33.0 parts were used instead of octadecyl methacrylate, and the polymer compound 1-l was produced in the same manner as the production of the above polymer compound 1-a.

[0328] [Production of Comparative Polymer Compound 1-m] A comparative polymer compound 1-m was produced in the same manner as the polymer compound 1-a, except that 102.6 parts of octadecyl methacrylate was used instead of 17.9 parts of 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate and 82.1 parts of octadecyl methacrylate.

[0329] The composition ratios and weight average molecular weights (Mw) of the polymer compounds 1-a to 1-m produced as described above are shown in Table 1. In Table 1, X represents the bonding site with the polymer main chain of the structural unit represented by formula (1), X' represents the bonding site with the phosphate ester site of the structural unit represented by formula (1), respectively. Y represents the bonding site with the phosphate ester site of the structural unit represented by formula (1), Y' represents the bonding site with the quaternary ammonium salt site of the structural unit represented by formula (1), and Z represents the bonding site with the polymer main chain of the structural unit represented by formula (4), respectively.

[0330]

Table 1

[0331] [Production of Polymer Compound 1-n] A reaction vessel equipped with a cooling pipe, a stirrer, a thermometer, and a nitrogen inlet pipe was prepared. 25.4 parts of 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propane-1-sulfonic acid, 36.1 parts of hexyl methacrylate, 4.1 parts of azobisisobutyronitrile, and 900 parts of 2,2,2-trifluoroethanol were charged into such a reaction vessel. Further, nitrogen bubbling was carried out for 30 minutes with respect to such a reaction vessel. The obtained reaction mixture was heated at 78 °C for 8 hours under a nitrogen atmosphere to complete the polymerization reaction. After the reaction solution was cooled to room temperature, the solvent was distilled off under reduced pressure. The obtained residue was dissolved in 2,2,2-trifluoroethanol and purified by dialysis using a dialysis membrane (Spectra / Por7 MWCO 1 kDa manufactured by Spectrum Laboratories). After the solvent was distilled off under reduced pressure, a polymer compound 1-n was obtained by drying under reduced pressure at 50 °C and 0.1 kPa or less.

[0332] [Production of Polymer Compound 1-o] A polymer compound 1-o was produced in the same manner as the above polymer compound 1-n, except that 42.3 parts of 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propane-1-sulfonic acid and 25.8 parts of hexyl methacrylate were used.

[0333] [Production of Polymer Compound 1-p] A polymer compound 1-p was produced in the same manner as the above polymer compound 1-n, except that 22.8 parts of 2-[[2-(methacryloyloxy)ethyl]dimethylammonio]acetic acid was used instead of 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propane-1-sulfonic acid and 33.5 parts of hexyl methacrylate was used.

[0334] The composition ratios and weight-average molecular weights (Mw) of the polymer compounds 1-n to p produced as described above are shown in Table 2. In Table 2, X represents the bonding site with the polymer main chain of the structural unit represented by formula (2), X’ represents the bonding site with the quaternary ammonium site of the structural unit represented by formula (2), respectively. Y represents the bonding site with the quaternary ammonium site of the structural unit represented by formula (2), Y’ represents the bonding site with the Y-site of the structural unit represented by formula (2), and Z represents the bonding site with the polymer main chain of the structural unit represented by formula (2), respectively.

[0335]

Table 2

[0336] (Example 1-1) [Preparation of Polymer Compound 1-Solution] (Toluene Solution of Polymer Compound 1-a) Into a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 1 part of polymer compound 1-a and 99 parts of toluene were charged, heated to 110 °C, and heated for 5 minutes as it was. After confirming that polymer compound 1-a was completely dissolved, it was cooled to room temperature to obtain a toluene solution of polymer compound 1-a.

[0337] [Production of Luminescent Nanocrystal Dispersion 1-a] 10 parts of cesium carbonate, 27 parts of oleic acid, and 385 parts of 1-octadecene were placed in a flask, the liquid temperature was heated to 120 °C, and degassed with a vacuum pump for 30 minutes. Further, the liquid temperature was heated to 150 °C under a dry nitrogen stream and held for 30 minutes to obtain a cation raw material solution.

[0338] Separately, 10 parts of lead(II) bromide and 494 parts of 1-octadecene were placed in a flask, the liquid temperature was heated to 120 °C, and degassed with a vacuum pump for 1 hour. 89 parts of oleic acid and 31 parts of oleylamine were added, and further degassed with a vacuum pump for 30 minutes. Then, the liquid temperature was changed to 185 °C instead of the nitrogen flow.

[0339] 40 parts of the cation raw material solution was added and ice-cooled 5 seconds later. 2000 parts of ethyl acetate was added and centrifuged to remove the supernatant. The obtained residue was dispersed in toluene to adjust the solid content concentration to 1 wt%, and a luminescent nanocrystal dispersion liquid 1-a having a perovskite crystal structure of CsPbBr3 was obtained.

[0340] [Preparation of Photoresponsive Material 1-1] 10 parts of the above luminescent nanocrystal dispersion liquid 1-a was placed in a container, and the solvent was distilled off under reduced pressure. 10 parts of a toluene solution of polymer compound 1-a was added thereto, and the mixture was stirred for 3 hours to obtain a photoresponsive material 1-1.

[0341] (Examples 1-2 to 10) Photoresponsive materials 1-2 to 10 were obtained in the same manner as in Example 1-1, except that shell-like ligands b to i were used instead of polymer compound 1-a.

[0342] [Production of Luminescent Nanocrystal Dispersion Liquid 1-b] A luminescent nanocrystal dispersion liquid 1-b having a perovskite crystal structure of CsPb(Br / I)3 was obtained in the same manner as in the luminescent nanocrystal dispersion liquid 1-a, except that 3.2 parts of lead(II) bromide and 9.3 parts of lead(II) iodide were used instead of 10 parts of lead(II) bromide.

[0343] (Example 1-11) A photoresponsive material 1-11 was obtained in the same manner as in Example 1-1, except that the luminescent nanocrystal dispersion liquid 1-b was used instead of the luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-g and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0344] (Example 1-12) A photoresponsive material 1-12 was obtained in the same manner as in Example 1-1, except that the luminescent nanocrystal dispersion liquid 1-b was used instead of the luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-n and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0345] (Example 1-13) A photo-responsive material 1-13 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion liquid 1-b was used instead of luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-p and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0346] [Production of Luminescent Nanocrystal Dispersion Liquid 1-c] A luminescent nanocrystal dispersion liquid 1-c having a perovskite crystal structure of CsPbI3 was obtained in the same manner as in the luminescent nanocrystal dispersion liquid 1-a, except that 12.5 parts of lead(II) iodide was used instead of 10 parts of lead(II) bromide.

[0347] (Example 1-14) A photo-responsive material 1-14 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion liquid 1-c was used instead of luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-g and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0348] (Example 1-15) A photo-responsive material 1-15 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion liquid 1-c was used instead of luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-n and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0349] (Example 1-16) A photo-responsive material 1-16 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion liquid 1-c was used instead of luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-p and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0350] [Production of Luminescent Nanocrystal Dispersion Liquid 1-c] A luminescent nanocrystal dispersion liquid 1-c having a perovskite crystal structure of CsPbI3 was obtained in the same manner as in the luminescent nanocrystal dispersion liquid 1-a, except that 12.5 parts of lead(II) iodide was used instead of 10 parts of lead(II) bromide.

[0351] [Production of Luminescent Nanocrystal Dispersion 1-d] First, an oleate solution of methylamine acetate was synthesized as follows. 1290 parts of oleic acid was mixed with 40 parts of methylamine acetate in a flask and degassed with a vacuum pump at room temperature for 3 hours. Further, the liquid temperature was raised to 120 °C and degassed for 30 minutes to obtain an oleate solution of methylamine acetate.

[0352] Next, an oleate solution of formamidine acetate was synthesized as follows. 1290 parts of oleic acid was mixed with 46 parts of formamidine acetate in a flask and degassed with a vacuum pump at room temperature for 3 hours. Further, the temperature was raised to 120 °C and degassed for 30 minutes to obtain an oleate solution of formamidine acetate.

[0353] Separately, 10 parts of lead bromide, 129 parts of oleic acid, 59 parts of oleylamine, and 572 parts of octadecene were placed in a flask, the liquid temperature was set to 160 °C, and degassed with a vacuum pump for 100 minutes. 16 parts of the above oleate solution of methylamine acetate and 77 parts of the above oleate solution of formamidine acetate were mixed and added to the flask all at once. Ten seconds after the addition, the entire flask was ice-cooled. The ice-cooled solution was centrifuged and the supernatant was removed. The obtained residue was dispersed in hexane and further centrifuged to remove the precipitate. The solid content concentration was adjusted to 1 wt%, and a luminescent nanocrystal dispersion 1-d having a perovskite crystal structure of (MA / FA)PbBr3 was obtained.

[0354] (Example 1-17) A photo-responsive material 1-17 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion 1-d was used instead of luminescent nanocrystal dispersion 1-a, and 0.5 part of polymer compound 1-g and 99.5 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0355] (Example 1-18) A photo-responsive material 1-18 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion liquid 1-d was used instead of luminescent nanocrystal dispersion liquid 1-a, and 0.5 part of polymer compound 1-n and 99.5 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0356] (Example 1-19) A photo-responsive material 1-19 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion liquid 1-c was used instead of luminescent nanocrystal dispersion liquid 1-a, and 0.8 part of polymer compound 1-p and 99.2 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0357] (Example 1-20) A photo-responsive material 1-20 was obtained in the same manner as in Example 1-1, except that 0.14 part of polymer compound 1-l and 99.86 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0358] (Example 1-21) A photo-responsive material 1-21 was obtained in the same manner as in Example 1-1, except that 0.020 part of polymer compound 1-l and 99.980 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0359] (Example 1-22) A photo-responsive material 1-22 was obtained in the same manner as in Example 1-1, except that 0.015 part of polymer compound 1-l and 99.985 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0360] (Example 1-23) A photo-responsive material 1-23 was obtained in the same manner as in Example 1-1, except that 1 part of polymer compound 1-j was used instead of 1 part of polymer compound 1-a.

[0361] (Example 1-24) A photo-responsive material 1-24 was obtained in the same manner as in Example 1-1, except that 0.19 part of polymer compound 1-g and 99.81 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0362] (Examples 1-25) A photosensitive material 1-25 was obtained in the same manner as in Example 1-1, except that 0.3 part of polymer compound 1-k and 99.7 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0363] (Examples 1-26) A photosensitive material 1-26 was obtained in the same manner as in Example 1-1, except that 3 parts of polymer compound 1-i and 97 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0364] (Examples 1-27) A photosensitive material 1-27 was obtained in the same manner as in Example 1-1, except that 4 parts of polymer compound 1-o and 96 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0365] (Examples 1-28) A photosensitive material 1-28 was obtained in the same manner as in Example 1-1, except that 4 parts of polymer compound 1-n and 96 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0366] (Examples 1-29) A photosensitive material 1-29 was obtained in the same manner as in Example 1-1, except that 5 parts of polymer compound 1-j and 95 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0367] (Comparative Example 1-1) A photosensitive material 1-30 was obtained in the same manner as in Example 1-1, except that 100 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0368] (Comparative Example 1-2) A photosensitive material 1-31 was obtained in the same manner as in Example 1-1, except that polymer compound 1-m was used instead of polymer compound 1-a.

[0369] (Comparative Example 1-3) Instead of 1 part of polymer compound 1-a1 and 99 parts of toluene, 0.2 part of octadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt (ligand 1-a, manufactured by Tokyo Chemical Industry Co., Ltd.) and 99.8 parts of toluene were used, and a photoreactive material 1-32 was obtained in the same manner as in Example 1-1.

[0370] (Comparative Example 1-4) Instead of the luminescent nanocrystal dispersion 1-a, a luminescent nanocrystal dispersion 1-b was used, and instead of 1 part of polymer compound 1-a1 and 99 parts of toluene, 100 parts of toluene were used, and a photoreactive material 1-33 was obtained in the same manner as in Example 1-1.

[0371] (Comparative Example 1-5) Instead of the luminescent nanocrystal dispersion 1-a, a luminescent nanocrystal dispersion 1-b was used, and instead of the polymer compound 1-a, a polymer compound 1-m was used, and a photoreactive material 1-34 was obtained in the same manner as in Example 1-1.

[0372] (Comparative Example 1-6) Instead of the luminescent nanocrystal dispersion 1-a, a luminescent nanocrystal dispersion 1-b was used, and instead of 1 part of polymer compound 1-a1 and 99 parts of toluene, 0.2 part of ligand 1-a and 99.8 parts of toluene were used, and a photoreactive material 1-35 was obtained in the same manner as in Example 1-1.

[0373] (Comparative Example 1-7) Instead of the luminescent nanocrystal dispersion 1-a, a luminescent nanocrystal dispersion 1-c was used, and instead of 1 part of polymer compound 1-a1 and 99 parts of toluene, 100 parts of toluene were used, and a photoreactive material 1-36 was obtained in the same manner as in Example 1-1.

[0374] (Comparative Example 1-8) Instead of the luminescent nanocrystal dispersion 1-a, a luminescent nanocrystal dispersion 1-c was used, and instead of the polymer compound 1-a, a polymer compound 1-m was used, and a photoreactive material 1-37 was obtained in the same manner as in Example 1-1.

[0375] (Comparative Example 1-9) A photo-responsive material 1-38 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion 1-b was used instead of luminescent nanocrystal dispersion 1-c, and 0.2 part of ligand 1-a and 99.8 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0376] (Comparative Example 1-10) A photo-responsive material 1-39 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion 1-d was used instead of luminescent nanocrystal dispersion 1-a, and 100 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0377] (Comparative Example 1-11) A photo-responsive material 1-40 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion 1-d was used instead of luminescent nanocrystal dispersion 1-a, and polymer compound 1-m was used instead of polymer compound 1-a.

[0378] (Comparative Example 1-12) A photo-responsive material 1-41 was obtained in the same manner as in Example 1-1, except that luminescent nanocrystal dispersion 1-d was used instead of luminescent nanocrystal dispersion 1-a, and 0.2 part of ligand 1-a and 99.8 parts of toluene were used instead of 1 part of polymer compound 1-a and 99 parts of toluene.

[0379] Table 3 shows the types and concentrations of luminescent nanocrystals, the types and concentrations of the added polymer compound 1 or ligand, and the number of mmol of betaine groups per 1 g of luminescent nanocrystals for photo-responsive materials 1-1 to 41.

[0380]

Table 3

[0381] (Evaluation of Photo-Responsive Composition 1-) The obtained photo-responsive material 1 was evaluated as follows. The results are shown in Table 4.

[0382] [Luminescence Property Evaluation] For each photo-responsive material 1, the emission peak wavelength, full width at half maximum, and absolute photoluminescence quantum yield (hereinafter referred to as PLQY) were measured immediately after preparation and 30 minutes after adding 2-propanol (hereinafter referred to as IPA) to a concentration of 50% by volume. After adding IPA, the samples containing the photo-responsive material 1 for emission characteristic evaluation were stored in a dark room in order to prevent the promotion of desorption of non-shell ligands by light and the inhibition of coordination of shell ligands.

[0383] The emission peak wavelength and full width at half maximum are the values of the emission spectrum that are the basis for calculating the PLQY, and the PLQY is the number of photons of fluorescence emission when the number of excited photons absorbed by the luminescent nanocrystal is set to 1. Each photo-responsive material 1 was diluted with toluene so that the light absorption rate at the excitation light wavelength was between 0.2 and 0.3, and then the measurement was performed. The measurement conditions and evaluation criteria are shown below.

[0384] <Measurement Conditions> Measuring device: Absolute PL quantum yield measuring device C9920-03 (manufactured by Hamamatsu Photonics) Excitation light wavelength: 460 nm Excitation light integration range: Excitation light wavelength ±10 nm Emission integration range: (Excitation light wavelength + 20) nm to 770 nm

[0385] <Evaluation Criteria P-1> When the PLQY immediately after preparation was set to 100, the value of the PLQY 30 minutes after adding the IPA solution was defined as P-1 and evaluated according to the following criteria.

[0386] Immediately after preparation, it was within 5 minutes from the time when the luminescent nanocrystal dispersion liquid 1-a was obtained. A: P-1 is 80 or more B: P-1 is 70 or more and less than 80 C: P-1 is 60 or more and less than 70 D: P-1 is less than 60 The actually measured value of the PLQY may vary by about a few percent within the range of the error of the measurement system, and may slightly exceed the change range of 0-100 of the ideal change rate. The PLQY change rate may exhibit 100 or more, and this was evaluated as AA.

[0387]

Table 4

[0388] According to Table 4, the photo-responsive materials 1-1 to 29 according to Examples 1-1 to 29 exhibit a high PLQY value and a low full width at half maximum (narrow full width at half maximum) immediately after preparation. Also, as can be read from Evaluation Criterion P-1, the photo-responsive materials 1-1 to 29 according to Examples 1-1 to 29 can maintain the PLQY value even when the polar solvent IPA is added. This is presumably because the nanoparticles 10 are protected by the shell-like ligand 20 having a specific structure in the photo-responsive materials 1-1 to 29 according to Examples 1-1 to 29, and the stability of the nanoparticles 10 is ensured.

[0389] Also, since the effect related to the stabilization of the nanoparticles 10 by the shell-like ligand is considered to be independent of the composition of the A-site and X-site in the luminescent nanocrystals, it is effective for other luminescent nanocrystals having a perovskite crystal structure. Furthermore, as will be described later, the effect related to the stabilization of the nanoparticles 10 by the shell-like ligand was also confirmed as an improvement in resistance to heat and light.

[0390] On the other hand, the photo-responsive materials 1 that do not contain the shell-like ligand 20, such as Comparative Examples 1-1, 4, 7, and 10, sometimes had a wide full width at half maximum or a low PLQY immediately after preparation. Furthermore, in the photo-responsive materials 1 that do not contain the shell-like ligand 20, such as Comparative Examples 1-1, 4, 7, and 10, deactivation was observed in the PLQY, which is a luminescence characteristic, when IPA was added.

[0391] Also, the photo-responsive materials 1 that contain a shell-like ligand that does not contain a betaine structure, such as Comparative Examples 1-2, 5, 8, and 11, sometimes had a wide full width at half maximum. Furthermore, in the photo-responsive materials 1 that contain a shell-like ligand that does not contain a betaine structure, such as Comparative Examples 1-2, 5, 8, and 11, deactivation was observed in the PLQY when IPA was added.

[0392] Also, when ligands containing a betaine structure were used as in Comparative Examples 1-3, 6, 9, and 12, the PLQY immediately after preparation was somewhat high, but deactivation was observed in the PLQY when IPA was added.

[0393] Acetone was added as a poor solvent to the photoreactive materials 1-9, followed by centrifugation. After removing the supernatant, the IR absorption spectrum of the obtained solid was measured. The obtained IR absorption spectrum showed an absorption peak at 1031 cm -1 derived from the S=O symmetric vibration of the sulfobetaine group, confirming the coordination to the nanoparticles 10 of the shell-like ligand 20.

[0394] [Production of Photoreactive Compositions 1-1 to 1-41] (Example 1-30) 20 parts of photoreactive material 1-1, 76 parts of 3,3,5-trimethylcyclohexyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name Biscoat #196) as a polymerizable compound, 4 parts of (1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins, trade name Omnirad184) as a polymerization initiator, and 4 parts of JR-603 (manufactured by Teika Corporation) as a scattering agent were blended to obtain photoreactive composition 1-1.

[0395] (Examples 1-31 to 39) Photoreactive compositions 1-2 to 10 were obtained in the same manner as in Example 1-30, except that photoreactive materials 1-2 to 10 were used instead of photoreactive material 1-1.

[0396] (Examples 1-40 to 45) Photoreactive compositions 1-11 to 16 were obtained in the same manner as in Example 1-30, except that 18 parts of photoreactive materials 1-11 to 16 and 78 parts of a polymerizable compound were used instead of 20 parts of photoreactive material 1-1 and 76 parts of a polymerizable compound.

[0397] (Examples 1-46 to 48) Instead of 20 parts of the photoreactive material 1-1 and 76 parts of the polymerizable compound, 15 parts of the photoreactive materials 1-17 to 19 and 81 parts of the polymerizable compound were used, and the photoreactive compositions 1-17 to 19 were obtained in the same manner as in Example 1-30.

[0398] (Example 1-49) Instead of 20 parts of the photoreactive material 1-1 and 76 parts of the polymerizable compound, 11.4 parts of the photoreactive material 1-20 and 85 parts of the polymerizable compound were used, and the photoreactive composition 1-20 was obtained in the same manner as in Example 1-30.

[0399] (Example 1-50) Instead of 20 parts of the photoreactive material 1-1 and 76 parts of the polymerizable compound, 10.20 parts of the photoreactive material 1-21 and 86 parts of the polymerizable compound were used, and the photoreactive composition 1-21 was obtained in the same manner as in Example 1-30.

[0400] (Example 1-51) Instead of 20 parts of the photoreactive material 1-1 and 76 parts of the polymerizable compound, 10.15 parts of the photoreactive material 1-22 and 86 parts of the polymerizable compound were used, and the photoreactive composition 1-22 was obtained in the same manner as in Example 1-30.

[0401] (Example 1-52) Instead of the photoreactive material 1-1, the photoreactive material 1-23 was used, and the photoreactive composition 1-23 was obtained in the same manner as in Example 1-30.

[0402] (Example 1-53) Instead of 20 parts of the photoreactive material 1-1 and 76 parts of the polymerizable compound, 11.9 parts of the photoreactive material 1-24 and 84 parts of the polymerizable compound were used, and the photoreactive composition 1-24 was obtained in the same manner as in Example 1-30.

[0403] (Example 1-54) Instead of 20 parts of the photoreactive material 1-1 and 76 parts of the polymerizable compound, 13 parts of the photoreactive material 1-25 and 83 parts of the polymerizable compound were used, and the photoreactive composition 1-25 was obtained in the same manner as in Example 1-30.

[0404] (Examples 1-55) A photosensitive composition 1-26 was obtained in the same manner as in Example 1-30, except that 40 parts of photosensitive material 1-26 and 56 parts of polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of polymerizable compound.

[0405] (Examples 1-56 to 57) Photosensitive compositions 1-27 to 1-28 were obtained in the same manner as in Example 1-30, except that photosensitive materials 1-27 to 1-28 were used instead of photosensitive material 1-1.

[0406] (Example 1-58) A photosensitive composition 1-29 was obtained in the same manner as in Example 1-30, except that 24 parts of photosensitive material 1-29 and 72 parts of polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of polymerizable compound.

[0407] (Comparative Examples 1-13) A photosensitive composition 1-30 was obtained in the same manner as in Example 1-30, except that 10 parts of photosensitive material 1-30 and 86 parts of polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of polymerizable compound.

[0408] (Comparative Example 1-14) A photosensitive composition 1-31 was obtained in the same manner as in Example 1-30, except that photosensitive material 1-31 was used instead of photosensitive material 1-1.

[0409] (Comparative Example 1-15) A photosensitive composition 1-32 was obtained in the same manner as in Example 1-30, except that 12 parts of photosensitive material 1-32 and 84 parts of polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of polymerizable compound.

[0410] (Comparative Example 1-16) A photosensitive composition 1-33 was obtained in the same manner as in Example 1-30, except that 10 parts of photosensitive material 1-33 and 86 parts of polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of polymerizable compound.

[0411] (Comparative Example 1-17) A photosensitive composition 1-34 was obtained in the same manner as in Example 1-30, except that photosensitive material 1-34 was used instead of photosensitive material 1-1.

[0412] (Comparative Example 1-18) A photosensitive composition 1-35 was obtained in the same manner as in Example 1-30, except that 12 parts of photosensitive material 1-35 and 84 parts of a polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of the polymerizable compound.

[0413] (Comparative Example 1-19) A photosensitive composition 1-36 was obtained in the same manner as in Example 1-30, except that 10 parts of photosensitive material 1-36 and 86 parts of a polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of the polymerizable compound.

[0414] (Comparative Example 1-20) A photosensitive composition 1-37 was obtained in the same manner as in Example 1-30, except that photosensitive material 1-37 was used instead of photosensitive material 1-1.

[0415] (Comparative Example 1-21) A photosensitive composition 1-38 was obtained in the same manner as in Example 1-30, except that 12 parts of photosensitive material 1-38 and 84 parts of a polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of the polymerizable compound.

[0416] (Comparative Example 1-22) A photosensitive composition 1-39 was obtained in the same manner as in Example 1-30, except that 10 parts of photosensitive material 1-39 and 86 parts of a polymerizable compound were used instead of 20 parts of photosensitive material 1-1 and 76 parts of the polymerizable compound.

[0417] (Comparative Example 1-23) A photosensitive composition 1-40 was obtained in the same manner as in Example 1-30, except that photosensitive material 1-40 was used instead of photosensitive material 1-1.

[0418] (Comparative Examples 1-24) A photoresponsive composition 1-41 was obtained in the same manner as in Example 1-30, except that 12 parts of photoresponsive material 1-41 and 84 parts of a polymerizable compound were used instead of 20 parts of photoresponsive material 1-1 and 76 parts of a polymerizable compound.

[0419] Table 5 shows the types and concentrations of the photoresponsive materials 1-, the concentrations of the polymerizable compounds, the concentrations of the polymerization initiators, and the concentrations of the scattering agents for the photoresponsive compositions 1-1 to 1-41.

[0420] [Table 5]

[0421] [Production of Wavelength Conversion Members 1-1 to 1-41] Using the obtained photoresponsive compositions 1-1 to 1-41, spin coating was performed on a glass substrate (10 cm × 10 cm). With respect to the glass substrate on which the spin-coated photoresponsive composition was formed, using a belt conveyor type ultraviolet irradiator (high-pressure mercury lamp 120 W / cm2 lamp), ultraviolet rays were irradiated so that the integrated light amount became 400 mJ / cm 2 to form a cured film with a thickness of 10 μm on the glass substrate. Thereafter, a barrier film was laminated on the surface of the cured film to obtain wavelength conversion members 1-1 to 1-41.

[0422] [Evaluation of Wavelength Conversion Members 1-1 to 1-41] The following evaluations were performed on the obtained wavelength conversion members 1-. The results are shown in Tables 6 and 7.

[0423] [Light Resistance Evaluation] For each wavelength conversion member 1-, the emission peak wavelength, the full width at half maximum, and the absolute photoluminescence quantum yield (hereinafter referred to as PLQY) were measured after irradiation with blue light having a wavelength of 460 nm and an intensity of 12,500 cd / cm 2 for 16 hours.

[0424] The measurement conditions are the same as those in the evaluation of the polar solvent resistance. The evaluation criteria are shown below.

[0425] <Evaluation Criteria> When the initial PLQY is set to 100, the value of PLQY after 16 hours of blue light irradiation is defined as P-2 and evaluated according to the following criteria. AA: P-2 is 100 or more A: P-2 is 80 or more and less than 100 B: P-2 is 70 or more and less than 80 C: P-2 is 60 or more and less than 70 D: P-2 is less than 60

[0426]

Table 6

[0427] [Thermal Resistance Evaluation] For each wavelength conversion member 1-, the emission peak wavelength, full width at half maximum, and absolute emission quantum yield (hereinafter referred to as PLQY) were measured after heating in an oven at 80°C for 16 hours.

[0428] The measurement conditions are the same as those during the evaluation of polar solvent resistance. The evaluation criteria are shown below.

[0429] <Evaluation Criteria> When the initial PLQY is set to 100, the value of PLQY after heating at 80°C for 16 hours is defined as P-3 and evaluated according to the following criteria. AA: P-3 is 100 or more A: P-3 is 80 or more and less than 100 B: P-3 is 70 or more and less than 80 C: P-3 is 60 or more and less than 70 D: P-3 is less than 60

[0430]

Table 7

[0431] According to Tables 6 and 7, the photoresponsive materials 1-30 to 58 according to Examples 1-30 to 58 exhibit a high PLQY and a narrow full width at half maximum immediately after preparation, and can maintain them even when stimulated by very strong blue light or heat for a long time. Also, since this effect does not depend on the composition of the A-site and X-site in the luminescent nanocrystals, it is effective for luminescent nanocrystals with a wide range of compositions. These effects are presumably because in the photoresponsive compositions 1-1 to 29 according to Examples 1-30 to 58, the nanoparticles 10 are protected by a specific shell-like ligand 20, ensuring the stability of the nanoparticles 10.

[0432] On the other hand, the photoresponsive materials 1- that do not contain the shell-like ligand 20, such as Comparative Examples 1-13, 16, 19, and 22, may have a wide full width at half maximum or a low PLQY immediately after preparation, and are deactivated when irradiated with blue light. Also, the photoresponsive materials 1 that contain a shell-like ligand without a betaine structure, such as Comparative Examples 1-14, 17, 20, and 23, may have a wide full width at half maximum and are deactivated when irradiated with blue light. When ligands containing a betaine structure are used, such as Comparative Examples 1-15, 18, 21, and 24, the full width at half maximum may be wide and they are deactivated when irradiated with blue light.

[0433] Hereinafter, the present disclosure will be described in more detail by a second group of examples, but the present disclosure is not limited thereto.

[0434] [Production of Polymer Compound 2-a] Into a reaction vessel equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen inlet tube, 15.8 parts of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (80% aqueous solution), 82.1 parts of octadecyl methacrylate, 4.1 parts of azobisisobutyronitrile, and 900 parts of n-butanol were charged, and nitrogen bubbling was carried out for 30 minutes. The obtained reaction mixture was heated at 65 °C for 8 hours under a nitrogen atmosphere to complete the polymerization reaction. After the reaction solution was cooled to room temperature, the solvent was distilled off under reduced pressure. The obtained residue was dissolved in chloroform and purified by dialysis using a dialysis membrane (Spectra / Por7 MWCO 1 kDa manufactured by Spectrum Laboratories). After the solvent was distilled off under reduced pressure, it was dried under reduced pressure at 50 °C and 0.1 kPa or less to obtain a polymer compound 2-a.

[0435] When the obtained polymer compound 2-a was analyzed by the above analytical method, it was confirmed that the weight average molecular weight (Mw) was 21,000 and the monomer containing the partial structure represented by the formula (1) was contained in 21 mol% in all monomer units.

[0436] [Production of Polymer Compound 2-b] A solution prepared by dissolving 5 parts of the polymer compound 2-a in 95 parts of tetrahydrofuran was slowly added with a solution prepared by dissolving 1.3 parts of sodium bromide in 2.7 parts of water, and the mixture was stirred at room temperature for 2 hours. The obtained solution was reprecipitated with water, washed with methanol, and then dried in vacuo at 50 °C for 2 hours to produce a polymer compound 2-b.

[0437] [Production of Polymer Compound 2-c] A polymer compound 2-c was produced in the same manner as the polymer compound 2-b, except that a solution prepared by dissolving 1.9 parts of sodium iodide in 2.0 parts of water was used instead of the solution prepared by dissolving 1.3 parts of sodium bromide in 2.7 parts of water.

[0438] [Production of Polymer Compound 2-d] The polymer compound 2-d was produced in the same manner as the polymer compound 2-b, except that a solution prepared by dissolving 0.39 part of sodium bromide and 1.3 parts of sodium iodide in 2.7 parts of water was used instead of the solution prepared by dissolving 1.3 parts of sodium bromide in 2.7 parts of water.

[0439] [Production of Polymer Compound 2-e] [2-(Methacryloyloxy)ethyl]trimethylammonium chloride (80% aqueous solution) 15.8 parts and octadecyl methacrylate 82.1 parts were replaced with [2-(methacryloyloxy)ethyl]trimethylammonium chloride (80% aqueous solution) 29.3 parts and octadecyl methacrylate 63.4 parts. 5 parts of the polymer compound obtained in the same manner as the polymer compound 2-a was dissolved in 95 parts of tetrahydrofuran, and a solution prepared by dissolving 1.9 parts of sodium iodide in 2.0 parts of water was slowly added thereto, followed by stirring at room temperature for 2 hours. The resulting solution was reprecipitated with water, washed with methanol, and then vacuum-dried at 50°C for 2 hours to produce the polymer compound 2-e.

[0440] [Production of Polymer Compound 2-f] Octyl methacrylate 48.1 parts was used instead of octadecyl methacrylate 82.1 parts to obtain the polymer compound 2-af in the same manner as the polymer compound 2-a. 5 parts of the obtained polymer compound 2-af was dissolved in 95 parts of tetrahydrofuran, and a solution prepared by dissolving 1.9 parts of sodium iodide in 2.0 parts of water was slowly added thereto, followed by stirring at room temperature for 2 hours. The resulting solution was reprecipitated with water, washed with methanol, and then vacuum-dried at 50°C for 2 hours to produce the polymer compound 2-f.

[0441] [Production of Polymer Compound 2-g] A polymer compound 2-ag was obtained in the same manner as polymer compound 2-a, except that 41.3 parts of hexyl methacrylate was used instead of 82.1 parts of octadecyl methacrylate. 5 parts of the thus obtained polymer compound 2-ag was dissolved in 95 parts of tetrahydrofuran, and a solution prepared by dissolving 1.9 parts of sodium iodide in 2.0 parts of water was slowly added thereto, followed by stirring at room temperature for 2 hours. The resulting solution was reprecipitated with water, washed with methanol, and then vacuum-dried at 50 °C for 2 hours to produce polymer compound 2-g.

[0442] [Production of Polymer Compound 2-h] A polymer compound 2-ah was obtained in the same manner as polymer compound 2-a, except that 34.5 parts of butyl methacrylate was used instead of 82.1 parts of octadecyl methacrylate. 5 parts of the thus obtained polymer compound 2-ah was dissolved in 95 parts of tetrahydrofuran, and a solution prepared by dissolving 1.9 parts of sodium iodide in 2.0 parts of water was slowly added thereto, followed by stirring at room temperature for 2 hours. The resulting solution was reprecipitated with water, washed with methanol, and then vacuum-dried at 50 °C for 2 hours to produce polymer compound 2-h.

[0443] [Production of Comparative Polymer Compound 2-i] A polymer compound for leather 2-i was produced in the same manner as polymer compound 2-a, except that 15.8 parts of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (80% aqueous solution) was used and 108 parts of octadecyl methacrylate was used instead of 82.1 parts of octadecyl methacrylate.

[0444] The composition ratios and weight-average molecular weights (Mw) of the polymer compounds 2-a to 2-i produced as described above are shown in Table 8. In Table 8, a represents the bonding site of R4 in formula (2) to the carbon atom, b represents the bonding site to the quaternary ammonium site, and c represents the bonding site of R5 in formula (3) to the carbon atom.

[0445] [Table 8]

[0446] (Example 2-1) [Preparation of Polymer Compound 2-Solution] (Toluene Solution of Polymer Compound 2-a) Into a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 0.5 part of polymer compound 2-a and 99.5 parts of toluene were charged, heated to 110°C, and heated for 5 minutes as it was. After confirming that polymer compound 2-a was completely dissolved, it was cooled to room temperature to obtain a toluene solution of polymer compound 2-a.

[0447] [Production of Nanoparticle Dispersion 2-a] 10 parts of cesium carbonate, 27 parts of oleic acid, and 385 parts of 1-octadecene were placed in a flask, the liquid temperature was heated to 120°C, and degassed with a vacuum pump for 30 minutes. Further, under a dry nitrogen stream, the liquid temperature was heated to 150°C and held for 30 minutes to obtain a cation raw material solution.

[0448] Separately, 10 parts of lead(II) bromide and 494 parts of 1-octadecene were placed in a flask, the liquid temperature was heated to 120°C, and degassed with a vacuum pump for 1 hour. 89 parts of oleic acid and 31 parts of oleylamine were added, and further degassed with a vacuum pump for 30 minutes. Then, the liquid temperature was set to 185°C instead of the nitrogen flow.

[0449] 40 parts of the cation raw material solution was added, and it was ice-cooled 5 seconds later. 2000 parts of ethyl acetate was added and centrifuged to remove the supernatant. The obtained residue was dispersed in toluene to adjust the solid content concentration to 1 wt% to obtain a nanoparticle dispersion 2-a having a perovskite crystal structure of CsPbBr3. The peak wavelength was 512 nm.

[0450] [Preparation of Photoresponsive Material 2-1] A dry nitrogen stream was blown onto 10 parts of the above nanoparticle dispersion 2-a to remove the solvent. 10 parts of the toluene solution of the above polymer compound 2-a was added thereto, and stirred for 3 hours to obtain a photoresponsive material 2-1.

[0451] (Example 2-2) A photoresponsive material 2-2 was obtained in the same manner as in Example 2-1, except that polymer compound 2-b was used instead of polymer compound 2-a.

[0452] (Example 2-3) A photosensitive material 2-3 was obtained in the same manner as in Example 2-1, except that 1 part of polymer compound 2-b and 99 parts of toluene were used instead of 0.5 part of polymer compound 2-a and 99.5 parts of toluene.

[0453] (Example 2-4) A photosensitive material 2-4 was obtained in the same manner as in Example 2-1, except that 1 part of polymer compound 2-c and 99 parts of toluene were used instead of 0.5 part of polymer compound 2-a and 99.5 parts of toluene.

[0454] [Production of nanoparticle dispersion 2-b] A nanoparticle dispersion 2-b having a perovskite crystal structure of CsPb(Br 0.3 / I 0.7 )3 was obtained in the same manner as in nanoparticle dispersion 2-a, except that 3.2 parts of lead(II) bromide and 9.3 parts of lead(II) iodide were used instead of 10 parts of lead(II) bromide. The peak wavelength was 640 nm.

[0455] (Example 2-5) A photosensitive material 2-5 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-b was used instead of nanoparticle dispersion 2-a.

[0456] (Example 2-6) A photosensitive material 2-6 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-b was used instead of nanoparticle dispersion 2-a and polymer compound 2-b was used instead of polymer compound 2-a.

[0457] (Example 2-7) A photosensitive material 2-7 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-b was used instead of nanoparticle dispersion 2-a and polymer compound 2-c was used instead of polymer compound 2-a.

[0458] (Example 2-8) A photosensitive material 2-8 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-b was used instead of the nanoparticle dispersion liquid 2-a, 1 part of polymer compound 2-c and 99 parts of toluene were used instead of 0.5 part of polymer compound 2-a and 99.5 parts of toluene, respectively.

[0459] (Example 2-9) A photosensitive material 2-9 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-b was used instead of the nanoparticle dispersion liquid 2-a and polymer compound 2-d was used instead of polymer compound 2-a.

[0460] (Example 2-10) A photosensitive material 2-10 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-b was used instead of the nanoparticle dispersion liquid 2-a and polymer compound 2-e was used instead of polymer compound 2-a.

[0461] [Production of Nanoparticle Dispersion Liquid 2-c] A nanoparticle dispersion liquid 2-c having a perovskite crystal structure of CsPbI3 was obtained in the same manner as in the nanoparticle dispersion liquid 2-a, except that 12.5 parts of lead(II) iodide was used instead of 10 parts of lead(II) bromide. The peak wavelength was 690 nm.

[0462] (Example 2-11) A photosensitive material 2-11 was obtained in the same manner as in Example 2-1, except that nanoparticle dispersion liquid 2-c was used instead of nanoparticle dispersion liquid 2-a.

[0463] (Example 2-12) A photosensitive material 2-12 was obtained in the same manner as in Example 2-1, except that nanoparticle dispersion liquid 2-c was used instead of nanoparticle dispersion liquid 2-a and polymer compound 2-b was used instead of polymer compound 2-a.

[0464] (Example 2-13) A photosensitive material 2-13 was obtained in the same manner as in Example 2-1, except that nanoparticle dispersion liquid 2-c was used instead of nanoparticle dispersion liquid 2-a and polymer compound 2-c was used instead of polymer compound 2-a.

[0465] (Comparative Example 2-1) A photoreactive material 2-14 was obtained in the same manner as in Example 2-1, except that 100 parts of toluene was used instead of 0.5 part of polymer compound 2-a and 99.5 parts of toluene.

[0466] (Comparative Example 2-2) A photoreactive material 2-15 was obtained in the same manner as in Example 2-1, except that dodecyldimethylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of polymer compound 2-a.

[0467] (Comparative Example 2-3) A photoreactive material 2-16 was obtained in the same manner as in Example 2-1, except that nanoparticle 2-c was used instead of nanoparticle dispersion liquid 2-a and polymer compound 2-i was used instead of polymer compound 2-a.

[0468] Table 9 shows the types of nanoparticles, their concentrations, the types of polymer compounds 2- or ligands added, and their concentrations for photoreactive materials 2-1 to 2-21.

[0469]

Table 9

[0470] The abbreviations in Table 9 are shown below. DDAB: Dodecyldimethylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0471] <Evaluation of Photoreactive Material 2-> The following evaluations were performed on the obtained photoreactive material 2-. The results are shown in Table 10.

[0472] [Luminescence Property Evaluation] For each photo-responsive material 2-, the emission peak wavelength, full width at half maximum, and absolute photoluminescence quantum yield (hereinafter referred to as PLQY) were measured immediately after preparation and 30 minutes after adding 2-propanol (hereinafter referred to as IPA) to a concentration of 50% by volume. After adding IPA, the samples were stored in a dark room to prevent the promotion of desorption of non-shell ligands by light and the inhibition of coordination of shell ligands.

[0473] The emission peak wavelength and full width at half maximum are the values of the emission spectrum used for calculating the PLQY, and the PLQY is the number of photons of fluorescence emission when the number of excited photons absorbed by the luminescent nanocrystals is set to 1. Each photo-responsive material was measured after being diluted with toluene so that the light absorption rate at the excitation light wavelength was between 0.2 and 0.3. The measurement conditions and evaluation criteria are shown below.

[0474] <Measurement Conditions> Measuring device: Absolute PL Quantum Yield Measuring Device C9920-03 (manufactured by Hamamatsu Photonics) Excitation light wavelength: 460 nm Excitation light integration range: Excitation light wavelength ± 10 nm Emission integration range: (Excitation light wavelength + 20) nm to 770 nm <Evaluation Criteria for PLQY Change> A: Absolute value of PLQY change rate less than 20% B: Absolute value of PLQY change rate 20% or more and less than 40% C: Absolute value of PLQY change rate 40% or more and less than 80% D: Absolute value of PLQY change rate 80% or more

[0475]

Table 10

[0476] According to Table 10, the photoresponsive materials 2-1 to 13 according to Examples 2-1 to 13 exhibit a high PLQY of 63% or more immediately after preparation, and they can be maintained even when the polar solvent IPA is added. This is presumably because in the photoresponsive materials 2-1 to 13 according to Examples 2-1 to 13, the nanoparticles 10 are protected by the shell-like ligand 20 having a specific structure, ensuring the stability of the nanoparticles 10.

[0477] On the other hand, the photoresponsive materials without the shell-like ligand 20, such as Comparative Examples 2-1 to 3, may have a low PLQY immediately after preparation and are greatly deactivated over time.

[0478] (Example 2-14) [Preparation of Polymer Compound 2-Solution] (Toluene Solution of Polymer Compound 2-b) Into a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 1 part of polymer compound 2-b and 99 parts of toluene were charged, heated to 110 °C, and heated for 5 minutes as it was. After confirming that the polymer compound 2-a was completely dissolved, it was cooled to room temperature to obtain a toluene solution of polymer compound 2-b.

[0479] [Preparation of Ink Composition 2-1] A dry nitrogen stream was blown onto 500 parts of the nanoparticle dispersion 2-a to remove the solvent. Then, 500 parts of the toluene solution of the above polymer compound 2-b was added, and the mixture was stirred for 3 hours. After stirring, a dry nitrogen stream was blown onto the solution again to remove the solvent. Then, it was dried, and 100 parts of 3,3,5-trimethylcyclohexyl acrylate (TMCHA) and 5 parts of 1-hydroxycyclohexyl phenyl ketone (Omnirad 184) were added to the solid component of the solution as a polymerizable compound and stirred well to obtain Ink Composition 2-1.

[0480] (Example 2-15) Ink Composition 2-2 was obtained in the same manner as in Example 2-14, except that tetrahydrofurfuryl acrylate (THFA) was used instead of TMCHA.

[0481] (Example 2-16) Ink composition 2-3 was obtained in the same manner as in Example 2-14, except that 1,6-hexanediol diacrylate (HDDA) was used instead of TMCHA.

[0482] (Example 2-17) Ink composition 2-4 was obtained in the same manner as in Example 2-14, except that nanoparticle dispersion 2-b was used instead of nanoparticle dispersion 2-a, and polymer compound 2-c was used instead of polymer compound 2-b.

[0483] (Example 2-18) Ink composition 2-5 was obtained in the same manner as in Example 2-15, except that tetrahydrofurfuryl acrylate (THFA) was used instead of TMCHA.

[0484] (Example 2-19) Ink composition 2-6 was obtained in the same manner as in Example 2-16, except that 1,6-hexanediol diacrylate (HDDA) was used instead of TMCHA.

[0485] (Example 2-20) Ink composition 2-7 was obtained in the same manner as in Example 2-14, except that nanoparticle dispersion 2-c was used instead of nanoparticle dispersion 2-a, and polymer compound 2-c was used instead of polymer compound 2-b.

[0486] (Example 2-21) Ink composition 2-8 was obtained in the same manner as in Example 2-20, except that tetrahydrofurfuryl acrylate (THFA) was used instead of TMCHA.

[0487] (Example 2-22) Ink composition 2-9 was obtained in the same manner as in Example 2-20, except that 1,6-hexanediol diacrylate (HDDA) was used instead of TMCHA.

[0488] (Example 2-23) An ink composition 2-10 was obtained in the same manner as in Example 2-14, except that nanoparticle dispersion liquid 2-c was used instead of nanoparticle dispersion liquid 2-a, and polymer compound 2-a was used instead of polymer compound 2-b.

[0489] (Example 2-24) An ink composition 2-11 was obtained in the same manner as in Example 2-17, except that cyclohexyl acrylate (CHA) was used instead of TMCHA.

[0490] (Example 2-25) An ink composition 2-12 was obtained in the same manner as in Example 2-17, except that 80 parts of TMCHA and 20 parts of HDDA were used instead of 100 parts of TMCHA.

[0491] (Example 2-26) An ink composition 2-13 was obtained in the same manner as in Example 2-17, except that polymer compound 2-f was used instead of polymer compound 2-c.

[0492] (Example 2-27) An ink composition 2-14 was obtained in the same manner as in Example 2-17, except that polymer compound 2-g was used instead of polymer compound 2-c.

[0493] (Example 2-28) An ink composition 2-15 was obtained in the same manner as in Example 2-17, except that polymer compound 2-h was used instead of polymer compound 2-c.

[0494] (Comparative Example 2-4) An ink composition 2-16 was obtained in the same manner as in Example 2-17, except that toluene was used instead of polymer compound 2-c.

[0495] (Comparative Example 2-5) An ink composition 2-17 was obtained in the same manner as in Example 2-17, except that dodecyldimethylammonium bromide (DDAB) was used instead of polymer compound 2-c.

[0496] (Comparative Example 2-6) An ink composition 2-18 was obtained in the same manner as in Example 2-17, except that the polymer compound 2-i was used instead of the polymer compound 2-c.

[0497]

Table 11

[0498] The abbreviations in Table 11 are shown below. TMCHA: 3,3,5-Trimethylcyclohexyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) HDDA: 1,6-Hexanediol diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) THFA: Tetrahydrofurfuryl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) CHA: Cyclohexyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) DDAB: Didodecyldimethylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0499] [Characteristic Evaluation] For the obtained ink compositions 2-1 to 16, the particle size distribution and the absolute photoluminescence quantum yield (hereinafter referred to as PLQY) were measured for the initial evaluation. Subsequently, the same ink compositions 2- were allowed to stand at 70% RH and 25 °C for 14 days using a thermo-hygrostat chamber, and then the particle size distribution and PLQY were measured for the evaluation after aging. The particle size distribution was measured using a Zetasizer Nano ZS (manufactured by Malvern), and the arithmetic mean diameter (number basis) of the particle size distribution was used as the measured value. The evaluation criteria were as follows.

[0500] <Initial Particle Size Evaluation Criteria> A: Initial particle size less than 30 nm B: Initial particle size of 30 nm or more and less than 60 nm C: Initial particle size of 60 nm or more and less than 90 nm D: Initial particle size of 90 nm or more

[0501] <Particle Size Change Evaluation Criteria> A: Particle size change less than 2 times B: Particle size change of 2 times or more and less than 3 times C: Particle size change is more than 3 times and less than 4 times D: Particle size change is 4 times or more

[0502] Here, the particle size change is defined as the particle size after aging / the initial particle size.

[0503] PLQY is the number of photons of fluorescence emission when the number of excited photons absorbed by the luminescent nanocrystal is set to 1. Each photo-responsive material was diluted with toluene so that the light absorption rate at the excitation wavelength was between 0.2 and 0.3, and then measured. The measurement conditions and evaluation criteria are shown below.

[0504] <Measurement conditions> Measuring device: Absolute PL quantum yield measuring device C9920-03 (manufactured by Hamamatsu Photonics) Excitation light wavelength: 460 nm Excitation light integration range: Excitation light wavelength ± 10 nm Emission light integration range: (Excitation light wavelength + 20) nm to 770 nm

[0505] <PLQY evaluation criteria> A: Absolute value of PLQY change rate is less than 10% B: Absolute value of PLQY change rate is 10% or more and less than 25% C: Absolute value of PLQY change rate is 25% or more and less than 40% D: Absolute value of PLQY change rate is 40% or more

[0506]

Table 12

[0507] According to Table 12, the ink compositions 2-1 to 15 according to Examples 2-14 to 28 of the present invention have a small initial particle size with respect to a plurality of media, and also have a small particle size change and PLQY change after aging. This is presumably because the shell-like ligand 20 having the quaternary ammonium salt 30b at the bonding portion 30 coordinates strongly to the nanoparticles 10, and the organic group 30a or 40a is compatible with the polymerizable compound 50, thereby exhibiting the dispersion stability of the photo-responsive material 330.

[0508] On the other hand, although the ink compositions 2-16 to 18 that do not contain the shell ligand 20 as in Comparative Examples 2-4 to 6 may have small initial particle sizes and small PLQY changes, it is presumed that in all cases, the particle sizes increase with time and constitute coarsened secondary particles.

[0509] Hereinafter, the present disclosure will be described in more detail by the third Example 3-group, but the present disclosure is not limited thereto.

[0510] [Production of Sulfobetaine Silane Compound] [3-(N,N-Dimethylamino)propyl]trimethoxysilane (5 g) and 1,3-propanesultone (3 g) were dissolved in 25 ml of acetone and stirred for 6 hours under a nitrogen atmosphere. After washing with acetone and filtering, 3-(dimethyl(3-(trimethoxysilyl)propyl)ammonia)propane-1-sulfonate was obtained as the sulfobetaine silane compound.

[0511] [Production of Carboxybetaine Silane Compound] (N,N-Dimethylaminopropyl)trimethoxysilane (5 g) was mixed with 7 g of ethyl-4-bromobutyrate in 20 ml of acetonitrile. After reacting for 72 hours under reflux, 60 ml of ether was added, and unreacted reactants were removed with a rotary evaporator to obtain the carboxybetaine silane compound.

[0512] (Example 3-1) [Preparation of Sulfobetaine Silane Compound Solution] (Toluene Solution of Sulfobetaine Silane Compound) Into a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene were charged, heated to 110°C, and heated for 30 minutes as it was. After confirming that the sulfobetaine silane compound had dissolved, it was cooled to room temperature to obtain a toluene solution of the sulfobetaine silane compound.

[0513] [Production of Luminescent Nanocrystal Dispersion a] 10 parts of cesium carbonate, 27 parts of oleic acid, and 385 parts of 1-octadecene were placed in a flask, the liquid temperature was heated to 120 °C, and degassed with a vacuum pump for 30 minutes. Further, the liquid temperature was heated to 150 °C under a dry nitrogen stream and held for 30 minutes to obtain a cation raw material solution.

[0514] Separately, 10 parts of lead(II) bromide and 494 parts of 1-octadecene were placed in a flask, the liquid temperature was heated to 120 °C, and degassed with a vacuum pump for 1 hour. 89 parts of oleic acid and 31 parts of oleylamine were added, and further degassed with a vacuum pump for 30 minutes. Then, the liquid temperature was set to 185 °C instead of the nitrogen flow.

[0515] 40 parts of the cation raw material solution was added and ice-cooled 5 seconds later. 2000 parts of ethyl acetate was added and centrifuged to remove the supernatant. The obtained residue was dispersed in toluene to adjust the solid content concentration to 1% by weight, and a dispersion of luminescent nanocrystals having a perovskite crystal structure of CsPbBr3 was obtained.

[0516] [Preparation of Photoresponsive Material 3-1] A dry nitrogen stream was blown onto 10 parts of the above luminescent nanocrystal dispersion a to remove the solvent. 10 parts of the toluene solution of the above sulfobetaine silane compound was added thereto, the lid of the reaction vessel was removed, and stirred for 1 hour. The organic silicon polymer part was formed by the reaction of the alkylsilane main chain of the sulfobetaine silane compound with moisture in the air and the progress of hydrolysis, and the photoresponsive material 3-1 was obtained.

[0517] (Example 3-2) A photoresponsive material 3-2 was obtained in the same manner as in Example 3-1 above, except that 0.5 part of the sulfobetaine silane compound and 99.5 parts of toluene were used instead of 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene.

[0518] (Example 3-3) A luminescent material 3 was obtained in the same manner as in Example 3-1 above, except that 1 part of the sulfobetaine silane compound and 99 parts of toluene were used instead of 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene.

[0519] (Example 3-4) A photosensitive material 3-4 was obtained in the same manner as in Example 3-1, except that 5 parts of a sulfobetaine silane compound and 95 parts of toluene were used instead of 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene.

[0520] (Example 3-5) A photosensitive material 3-5 was obtained in the same manner as in Example 3-1, except that carboxybetaine was used instead of the sulfobetaine silane compound.

[0521] (Example 3-6) To 97 parts of the photosensitive material 3-3 obtained in Example 3-3, 3 parts of tetraethoxysilane (TEOS) was gradually added over 3 hours, and the mixture was further stirred for 2 hours to allow hydrolysis to proceed. Then, centrifugation was performed to remove the supernatant. The obtained residue was dispersed in toluene to adjust the solid content concentration to 0.5% by weight, and a photosensitive material 3-6 was obtained.

[0522] [Production of Luminescent Nanocrystal Dispersion b] A luminescent nanocrystal dispersion b having a perovskite crystal structure of CsPb(Br / I)3 was obtained in the same manner as in the luminescent nanocrystal dispersion a, except that 3.3 parts of lead(II) bromide and 9.3 parts of lead(II) iodide were used instead of 10 parts of lead(II) bromide.

[0523] (Example 3-7) A photosensitive material 3-7 was obtained in the same manner as in Example 3-1, except that the luminescent nanocrystal dispersion b was used instead of the luminescent nanocrystal dispersion a, and 0.5 part of the sulfobetaine silane compound and 99.5 parts of toluene were used instead of 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene.

[0524] [Production of Luminescent Nanocrystal Dispersion c] A luminescent nanocrystal dispersion c having a perovskite crystal structure of CsPbI3 was obtained in the same manner as in the luminescent nanocrystal dispersion a, except that 12.5 parts of lead(II) iodide was used instead of 10 parts of lead(II) bromide.

[0525] (Example 3-8) A photo-responsive material 3-8 was obtained in the same manner as in Example 3-1, except that luminescent nanocrystal dispersion liquid c was used instead of luminescent nanocrystal dispersion liquid a, and 0.5 part of sulfobetaine silane compound and 99.5 parts of toluene were used instead of 2.5 parts of sulfobetaine silane compound and 97.5 parts of toluene.

[0526] [Production of Luminescent Nanocrystal Dispersion Liquid d] First, an oleic acid salt solution of methylamine acetate was synthesized as follows. 1290 parts of oleic acid was mixed with 40 parts of methylamine acetate in a flask and degassed at room temperature with a vacuum pump for 3 hours. Further, the liquid temperature was raised to 120 °C and degassed for 30 minutes to obtain an oleic acid salt solution of methylamine acetate.

[0527] Next, an oleic acid salt solution of formamidine acetate was synthesized as follows. 1290 parts of oleic acid was mixed with 46 parts of formamidine acetate in a flask and degassed at room temperature with a vacuum pump for 3 hours. Further, the temperature was raised to 120 °C and degassed for 30 minutes to obtain an oleic acid salt solution of formamidine acetate.

[0528] Separately, 10 parts of lead bromide, 129 parts of oleic acid, 59 parts of oleylamine, and 572 parts of octadecene were placed in a flask, the liquid temperature was set to 160 °C, and degassed with a vacuum pump for 100 minutes. 16 parts of the above oleic acid salt solution of methylamine acetate and 77 parts of the above oleic acid salt solution of formamidine acetate were mixed and added to the flask all at once. The flask was immediately ice-cooled 10 seconds after the addition. The ice-cooled solution was centrifuged, and the supernatant was removed. The obtained residue was dispersed in hexane and further centrifuged to remove the precipitate. The solid content concentration was adjusted to 1% by weight to obtain a luminescent nanocrystal dispersion liquid d having a perovskite crystal structure of (MA / FA)PbBr3.

[0529] (Example 3-9) Instead of using the luminescent nanocrystal dispersion a, the luminescent nanocrystal dispersion d was used, and instead of 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene, 0.5 part of the sulfobetaine silane compound and 99.5 parts of toluene were used. Otherwise, the same procedure as in Example 3-1 was followed to obtain the photoreactive material 3-9.

[0530] [Production of Sulfobetaine Silane Compound b] 5 g of (N,N-dimethyl-3-aminopropyl)methyldimethoxysilane and 3 g of 1,3-propanesultone were dissolved in 25 ml of acetone and stirred for 6 hours under a nitrogen atmosphere. After washing with acetone, filtration was performed to obtain the sulfobetaine silane compound b. Here, the sulfobetaine silane compound b is the case where R7 is a methyl group in (Formula 4).

[0531] (Example 3-10) Instead of using 2.5 parts of the sulfobetaine silane compound and 97.5 parts of toluene, 1.0 part of the sulfobetaine silane compound b and 99.0 parts of toluene were used. Otherwise, the same procedure as in Example 3-1 was followed to obtain the photoreactive material 3-10.

[0532] (Comparative Example 3-1) Instead of using 1 part of the sulfobetaine silane compound and 99 parts of toluene, 100 parts of toluene were used. Otherwise, the same procedure as in Example 3-1 was followed to obtain the photoreactive material 3-11.

[0533] (Comparative Example 3-2) Instead of using 31 parts of oleylamine, 34 parts of 3-aminopropyltriethoxysilane, which is an aminoalkylsilane compound, were used, and instead of using 1 part of the sulfobetaine silane compound and 99 parts of toluene, 100 parts of toluene were used. Otherwise, the same procedure as in Example 3-1 was followed to obtain the photoreactive material 3-12.

[0534] (Comparative Example 3-3) As a ligand containing a betaine structure (hereinafter referred to as a betaine ligand) instead of the sulfobetaine silane compound, a photo-responsive material 3-13 was obtained in the same manner as in Example 3-1 except that 1 part of octadecyldimethyl(3-sulfopropyl)ammonium hydroxide inner salt and 99.0 parts of toluene were used.

[0535] (Comparative Example 3-4) A photo-responsive material 3-14 was obtained in the same manner as in Comparative Example 3-3 except that a luminescent nanocrystal dispersion b was used instead of the luminescent nanocrystal dispersion a.

[0536] (Comparative Example 3-5) A photo-responsive material 3-15 was obtained in the same manner as in Comparative Example 3-3 except that a luminescent nanocrystal dispersion c was used instead of the luminescent nanocrystal dispersion a.

[0537] (Comparative Example 3-6) A photo-responsive material 3-16 was obtained in the same manner as in Comparative Example 3-3 except that a luminescent nanocrystal dispersion d was used instead of the luminescent nanocrystal dispersion a.

[0538] Table 13 shows the types and concentrations of the luminescent nanocrystals and the types and concentrations of the added compounds for the photo-responsive materials 3-1 to 16.

[0539] [Table 13]

[0540] [Evaluation of Photo-Responsive Material Composition] The following evaluations were performed on the obtained photo-responsive materials. The results are shown in Table 14.

[0541] [Luminescence Property Evaluation] For each photo-responsive material, the emission peak wavelength, full width at half maximum, and absolute photoluminescence quantum yield (hereinafter referred to as PLQY) were measured immediately after preparation and 30 minutes after adding 2-propanol (hereinafter referred to as IPA) to a volume fraction of 50%.

[0542] The emission peak wavelength and the full width at half maximum are the values of the emission spectrum that are the basis for calculating the PLQY. The PLQY is the number of photons of fluorescence emission when the number of excited photons absorbed by the luminescent nanocrystal is set to 1. Each photoreactive material was diluted with toluene so that the light absorption rate at the excitation wavelength was between 0.2 and 0.3, and then measured. The measurement conditions and evaluation criteria are shown below.

[0543] <Measurement Conditions> Measuring device: Absolute PL quantum yield measuring device C9920-03 (manufactured by Hamamatsu Photonics) Excitation light wavelength: 460 nm Excitation light integration range: Excitation light wavelength ±10 nm Emission integration range: (Excitation light wavelength + 20) nm to 770 nm

[0544] <Evaluation Criteria> When the initial PLQY was set to 100, the PLQY after adding IPA was evaluated according to the following criteria. A: The change rate of PLQY is 90 or more and 100 or less B: The change rate of PLQY is 80 or more and less than 90 C: The change rate of PLQY is 60 or more and less than 80 D: The change rate of PLQY is less than 60

[0545]

Table 14

[0546] According to Table 14, the photoreactive material of this embodiment has a high PLQY and a narrow full width at half maximum immediately after production, and can maintain them even when IPA, a polar solvent, is added. This is presumably because the photoreactive materials 3-1 to 10 according to this example are protected by a silica shell formed by an organosilicon polymer part containing a betaine structure, and thus have excellent stability.

[0547] On the other hand, when neither the betaine ligand nor the alkylsilane compound is contained as in Comparative Example 3-1, the PLQY immediately after production is low, and furthermore, it is greatly deactivated 30 minutes after adding IPA.

[0548] Also, when it contains an alkylsilane compound but does not contain a betaine structure as in Comparative Example 3-2, although improvement was observed in the PLQY immediately after preparation and the change over time 30 minutes after IPA addition compared to Comparative Example 3-1, the absolute value of the PLQY was not sufficient and the change rate was as large as 20% or more.

[0549] Also, for the cases of Comparative Examples 3-3 to 6 which contain the betaine structure 30b but do not contain the alkylsilane compound corresponding to the organosilicon polymer part, similarly, the absolute value of the PLQY was not sufficient and the change rate was also as large as 50% or more.

[0550] To protect the surface of the perovskite-type quantum dots and achieve stabilization against the external atmosphere (oxygen, moisture) and solvents, it is considered important to first strongly and densely coordinate the raw materials for the protective material, and then react the coordinated protective material to form a strong shell. When using a betaine ligand as in Comparative Example 3-3, it coordinates strongly but has a weak function as a shell layer and weak resistance to the external environment such as solvents. Also, when using an aminoalkylsilane which is a silane coupling agent having a coordinating amino group as in Comparative Example 3-2, the bond between the quantum dot surface and the amino group is weak and it is considered that desorption occurs repeatedly. In addition, oleic acid also coexists as a ligand and is considered to be coordinated to the quantum dots. Therefore, there are portions where the density of the alkylsilane raw material near the quantum dot surface is low, and it is considered that a part of the silica shell formed by hydrolysis is sparse.

[0551] By using a betaine silane compound with a relatively small molecular weight and less steric hindrance as in this embodiment, first, the betaine structure acts on the surface of the quantum dots and can be coordinated firmly and densely. Subsequently, the alkylsilane compound linked to the betaine structure is hydrolyzed to form an organosilicon polymer part, and by forming a silica shell, a shell layer can be formed densely on the surface of the quantum dots. As a result, it is considered that the non-emitting portions associated with the defects present on the surface of the quantum dots are relaxed by the betaine structure and the silica shell, improving the PLQY, and further improving the resistance to external environments such as solvents.

[0552] <Manufacture of wavelength conversion member> (Example 3-11) 20 parts of the photoreactive material 3-1, 76 parts of 3,3,5-trimethylcyclohexyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name Biscoat #196) as a polymerizable compound, 4 parts of (1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins Co., Ltd., trade name Omnirad184) as a polymerization initiator, and 4 parts of JR-603 (manufactured by Teika Corporation) as a scattering agent were blended to obtain a photoreactive composition.

[0553] Using the obtained photoreactive composition, spin coating was performed on a glass substrate (10 cm × 10 cm). Next, using a belt conveyor type ultraviolet irradiator (high-pressure mercury lamp 120 W / cm2 lamp), ultraviolet rays were irradiated so that the integrated light quantity became 400 mJ / cm 2 After forming a cured film with a thickness of 10 μm on the glass substrate, a barrier film was laminated on the surface to obtain a wavelength conversion member 3-1.

[0554] (Examples 3-12 to 20) Wavelength conversion members 3-2 to 10 were obtained in the same manner as in Example 3-11, except that photoreactive materials 3-2 to 10 were used instead of the photoreactive material 3-1.

[0555] (Comparative Examples 3-7 to 12) Except for using the photo-responsive materials 3-11 to 3-16 instead of the photo-responsive material 3-1, wavelength conversion members 3-10 to 3-16 were obtained in the same manner as in Example 3-11.

[0556]

Table 15

[0557] According to Table 15, the light-emitting conversion members 1 to 10 according to Examples 3-11 to 3-20 exhibit a high PLQY and a narrow full width at half maximum immediately after fabrication, and can maintain them even when stimulated by very strong blue light for a long time. Further, since this effect does not depend on the composition of the A-site and X-site in the luminescent nanocrystals, it is effective for luminescent nanocrystals with a wide range of compositions. It is presumed that these effects are due to the protection of the nanoparticles 10 by the specific shell-like ligand 20, which ensures the stability of the nanoparticles 10.

[0558] (Example 3-21) 10 parts of the photo-responsive material 3-1, 100 parts of 3,3,5-trimethylcyclohexyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name Biscoat #196) as a polymerizable compound, 5 parts of (1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins Co., Ltd., trade name Omnirad184) as a polymerization initiator, and 50 parts of toluene as a solvent were blended to obtain a photo-responsive material 3-composition 17. For the obtained photo-responsive material 3-composition 17, the particle size distribution and PLQY were measured for initial evaluation. Next, the same photo-responsive material 3-composition was allowed to stand at 70% RH and 25 °C for 14 days using a thermo-hygrostat chamber, and then the particle size distribution and PLQY were measured for evaluation after aging. PLQY was measured under the same conditions as above. The particle size distribution was measured using a Zetasizer Nano ZS (manufactured by Malvern), and the arithmetic mean diameter (number-based) of the particle size distribution was used as the measured value. The particle size was 18 nm initially and 20 nm after aging. PLQY was 95% initially and 92% after aging.

[0559] According to the evaluation results, it was found that the photoreactive materials 3- of Examples 3-7 had excellent stability because they were protected by the organosilicon polymer part.

[0560] The inventions according to each embodiment described in the specification of the present application include the following First Invention to Fourteenth Invention. · The First Invention includes a photoreactive material including nanoparticles having a perovskite crystal structure, a plurality of bonding parts including structural units exhibiting ionicity, and a polymer part bonded to the nanoparticles at a plurality of locations via the plurality of bonding parts. · The Second Invention includes the photoreactive material according to the First Invention, wherein the structural unit exhibiting ionicity includes a structure exhibiting zwitterionicity. · The Third Invention includes the photoreactive material according to the Second Invention, wherein the structure exhibiting zwitterionicity includes a betaine structure. · The Fourth Invention includes the photoreactive material according to any one of the First to Third Inventions, wherein the plurality of bonding parts include structural units represented by at least any one of Formula (1) to Formula (5).

[0561]

Chemical formula

[0562]

Chemical formula

[0563]

Chemical formula

[0564] Here, in Formulas (1) to (3), R1 to R5, R 13 ~R 15 are each independently either a hydrogen atom or an alkyl group, N is a nitrogen atom, A1 to A5 are linking groups, and Y - is a COO - group or a SO3 -The base, where " * " represents a bond to the organic polymer part,

[0565]

Chemical formula

[0566] Here, in formula (4), R6 to R8 each independently represent either an alkyl group or an aryl group, N represents a nitrogen atom, N represents a nitrogen atom, A6 represents a linking group, X - is an anion, and " * " represents a bond to the polymer part.

[0567]

Chemical formula

[0568] Here, in formula (5), R9 to R 11 each independently represent either an alkyl group or an aryl group, R 12 represents either a hydrogen atom or an alkyl group, N represents a nitrogen atom, A7 represents a linking group, and X - represents an anion. · The fifth invention includes the photosensitive material according to the fourth invention, wherein the plurality of bonding parts contain a structural unit represented by at least one of formulas (1) to (3) as a betaine part. · The sixth invention includes the photosensitive material according to the fourth invention, wherein the plurality of bonding parts contain a structural unit represented by at least one of formulas (4) and (5) as a quaternary ammonium salt. · The seventh invention includes the photosensitive material according to any one of the first to sixth inventions, wherein the shell-like ligand has at least a part coordinated to the nanoparticles. · The eighth invention includes the photosensitive material according to any one of the first to seventh inventions, wherein the polymer part has a structural unit represented by any one of formulas (6) to (8).

[0569]

Chemical formula

[0570] Here, in formula (6), R16 represents either a hydrogen atom or an alkyl group, and R 17 represents either an alkyl group, a carboxylic acid ester group, a carboxylic acid amide group, an alkoxy group, or an aryl group.

[0571] [Chemical formula]

[0572] Here, in formula (7), R 18 represents either a hydrogen atom or an alkyl group, and B represents a bond to the bonding portion.

[0573] [Chemical formula]

[0574] Here, in formula (8), R 19 represents an alkyl group, and B represents a bond to the bonding portion. · Invention No. 9 includes a photoresponsive material according to any one of Inventions Nos. 1 to 8, wherein the shell-like ligand is coordinated to cover the outer periphery of the nanoparticles. · Invention No. 10 includes a photoresponsive material according to any one of Inventions Nos. 1 to 9, wherein the number average molecular weight of the shell-like ligand is 1,000 or more and 50,000 or less. · Invention No. 11 includes a photoresponsive composition including a photoresponsive material according to any one of Inventions Nos. 1 to 10 and a polymerizable compound. · Invention No. 12 includes a wavelength conversion member in which the photoresponsive composition according to Invention No. 11 is cured together with the polymerizable compound. · Invention No. 13 includes a wavelength conversion layer in which the wavelength conversion member according to Invention No. 12 has an optical coupling surface that is optically coupled to a light source that emits light of a first wavelength. · Invention No. 14 includes a wavelength conversion layer according to Invention No. 13, in which the photoresponsive material emits light of a second wavelength that is longer than the light of the first wavelength received through the optical coupling surface. [Explanation of symbols]

[0575] 100, 120, 140, 160, 180, 190 photo-responsive materials 200 Ink composition (photo-responsive composition) 10 Nanoparticles (nanocrystals) 20 Shell-like ligands 30 Junction 30b Structure exhibiting zwitterionic properties (betaine moiety, quaternary ammonium salt) 40 Polymer moiety

Claims

1. A luminescent nanoparticle having a perovskite crystal structure that absorbs excitation light and emits light with a longer wavelength than the excitation light, A luminescent material comprising a shell-like ligand that coordinates to the surface of the nanoparticles, The shell-shaped ligand has a plurality of binding portions containing a zwitterionic structural unit including a betaine structure, and a polymer portion that is bound to the nanoparticles at a plurality of locations via the plurality of binding portions. The content of the shell-shaped ligand is 1 part by mass or more and 1000 parts by mass or less, when the content of the nanoparticles is 100 parts by mass, in the luminescent material.

2. The luminescent material according to Claim 1, wherein the content of the shell-shaped ligand is 5 parts by mass or more and 500 parts by mass or less, when the content of the nanoparticles is 100 parts by mass.

3. The luminescent material according to claim 1 or 2, wherein the number of mmol of the betaine structure per gram of nanoparticles is 0.01 or more and 10 or less.

4. The luminescent material according to claim 1 or 2, wherein the number of mmol of the betaine structure per gram of nanoparticles is 0.03 or more and 8 or less.

5. The luminescent material according to claim 1 or 2, wherein the shell-shaped ligand comprises a structural unit of the bonding portion represented by at least one of formulas (1) to (3). 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 Here, in formulas (1) to (3), R １ to R ５ , R １３ to R １５ are each independently either a hydrogen atom or an alkyl group, N is a nitrogen atom, A １ to A ５ is a linking group, Y － is a COO － group or a SO ３ － group, and "*" represents a bond to the polymer part.

6. The luminescent material according to claim 5, wherein the polymer portion has a structural unit represented by formula (6). 【Chemistry 4】 Here, in formula (6), R 16 represents either a hydrogen atom or an alkyl group, and R 17 represents either an alkyl group, a carboxylic acid ester group, a carboxylic acid amide group, an alkoxy group, or an aryl group.

7. R in formula (6) １７ The luminescent material according to claim 1 or 2, wherein is an alkyl group having 8 or more carbon atoms and 30 or fewer carbon atoms.

8. R in formula (6) １７ is a carboxylic acid ester group (-COOR ２４ ) and R ２４ The luminescent material according to claim 6, wherein is an alkyl group having 8 or more carbon atoms and 30 or fewer carbon atoms.

9. The luminescent material according to claim 5, wherein the molar ratio of structural units represented by at least one of formulas (1) to (3) to structural units represented by formula (6) in the copolymer is 6 / 94 or more and 45 / 55 or less.

10. The luminescent material according to claim 1 or 2, wherein the polymer portion includes a (meth)acrylate-based polymer chain.

11. The luminescent material according to claim 1 or 2, wherein the shell-shaped ligand is coordinated to cover the outer circumference of the nanoparticles.

12. The luminescent material according to claim 1 or 2, wherein the number-average molecular weight of the shell-shaped ligand is 1,000 or more and 50,000 or less.

13. The luminescent material according to claim 1 or 2, wherein the number-average molecular weight of the shell-shaped ligand is 2,000 or more and 30,000 or less.

14. An ink composition comprising the luminescent material according to claim 1 or 2 and a polymerizable compound.

15. A wavelength conversion member obtained by curing the ink composition according to claim 14 together with the polymerizable compound.

16. The wavelength conversion member according to claim 15 is a wavelength conversion layer having an optical coupling surface that optically couples with a light source that emits light of a first wavelength.

17. The wavelength conversion layer according to claim 16, wherein the photoresponsive material emits light of a second wavelength, which has a longer wavelength than the first wavelength of light received through the optical coupling surface.

18. A display element having an emissive layer and a wavelength conversion layer in this order, The wavelength conversion layer is a display element having the light-emitting material described in claim 1 or 2.

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