TW202104535A - Composition for cured-film formation, wavelength conversion film, light-emitting display element, and method for forming wavelength conversion film - Google Patents

Abstract

The composition for cured-film formation of the present invention comprises (A) semiconductor nanoparticles and (B) a urethane (meth)acrylate having a plurality of polymerizable groups. The wavelength conversion film of the present invention is formed from the composition for cured-film formation. The light-emitting display element of the present invention includes the wavelength conversion film. The present invention can provide: a composition for cured-film formation which has satisfactory dispersion stability and applicability and gives wavelength conversion films having satisfactory fluorescence performance; a wavelength conversion film formed from this composition for cured-film formation; a light-emitting display element; and a method for forming the wavelength conversion film.

Description

Composition for forming cured film, wavelength conversion film, light-emitting display element, and method for forming wavelength conversion film

The present invention relates to a composition for forming a cured film, a wavelength conversion film, a light-emitting display element, and a method for forming a wavelength conversion film.

In recent years, semiconductor nanoparticles obtained by forming semiconductors such as cadmium sulfide (CdS), cadmium telluride (CdTe), and indium phosphide (InP) into nanometer sizes have attracted attention. Such semiconductor nanoparticles exhibit special optical properties, that is, they exhibit broad light absorption and emit fluorescence with a narrow spectral width. Therefore, various applications are currently being studied. For example, organic electroluminescence (EL) elements, micro-sized light-emitting diode elements (micro LED (Light-Emitting Diode) elements), etc., are gradually used in displays or lighting, etc. ( Refer to Japanese Patent Laid-Open No. 2014-174406).

In the formation of a wavelength conversion film containing semiconductor nanoparticles, a method of coating a curable composition containing semiconductor nanoparticles is widely used. As such a composition, a composition containing semiconductor nanoparticles, a polymerizable compound, a polymerization initiator, a polymer, and the like is known (see Japanese Patent Laid-Open No. 2015-28139). In the above publication, as the polymerizable compound, a polyfunctional acrylate such as 1,9-nonanediol diacrylate is used. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-174406 [Patent Document 2] Japanese Patent Laid-Open No. 2015-28139

[The problem to be solved by the invention] For the composition used to form the wavelength conversion film, the obtained wavelength conversion film is required to have a high fluorescence quantum yield and a narrow half-value width of the fluorescence spectrum. In particular, such a wavelength conversion film may be cured by heating, and it is important that it has good fluorescent properties even when the wavelength conversion film is obtained by heating. In addition, as the composition, it is desirable that the dispersion stability and coating properties are also good. However, in the previous composition containing semiconductor nanoparticles and using a polyfunctional acrylate as a polymerizable compound, in terms of the fluorescent performance of the obtained wavelength conversion film or the handleability of the composition, etc., There is still room for improvement.

The present invention is based on the above situation, and its object is to provide a cured film forming composition having good dispersion stability and coating properties, and also good fluorescence performance of the obtained wavelength conversion film, and a composition for forming a cured film from such a cured film A wavelength conversion film and a light-emitting display element formed by the composition, and a method for forming the wavelength conversion film. [Means to solve the problem]

The invention made to solve the above-mentioned problems is a composition for forming a cured film, which contains: (A) semiconductor nanoparticle and (B) urethane (meth)acrylic acid having a plurality of polymerizable groups ester.

Another invention made to solve the above-mentioned problem is a wavelength conversion film formed from the cured film forming composition.

Another invention made in order to solve the above-mentioned problem is a light-emitting display element including the wavelength conversion film.

Another invention made in order to solve the problem is a method of forming a wavelength conversion film, which includes a step of directly or indirectly forming a coating film on a substrate, and a step of heating the coating film, and the hardening The composition for film formation forms the coating film. [Effects of the invention]

According to the present invention, it is possible to provide a composition for forming a cured film having good dispersion stability and coating properties, and also good fluorescence performance of the obtained wavelength conversion film, and a wavelength conversion film formed from the composition for forming such a cured film And a light-emitting display element, and a method for forming the wavelength conversion film.

<Composition for forming cured film> The cured film forming composition of one embodiment of the present invention contains (A) semiconductor nanoparticle and (B) urethane (meth)acrylate having a plurality of polymerizable groups. In this cured film formation composition, by using (B) urethane (meth)acrylate as a polymerizable compound together with (A) semiconductor nanoparticles, dispersion stability and coating properties are improved. Good, and the fluorescent performance of the obtained wavelength conversion film also becomes good. Regarding the fluorescent performance, the wavelength conversion film obtained from the cured film forming composition has a high fluorescence quantum yield and a narrow half-value width of the fluorescence spectrum. Furthermore, the narrower the half-value width of the fluorescence spectrum, the more it means that the wavelength can be converted into fluorescence with high color purity. Furthermore, the wavelength conversion film formed of this cured film formation composition has sufficient fluorescence quantum yield even when it is heat-processed.

In order to improve dispersion stability, coatability, fluorescent performance, etc., the composition for forming a cured film preferably further contains one or both of (C) light diffusion particles and (D) polymer. The composition for forming a cured film may further contain (E) an antioxidant, (F) a dispersion medium, (G) a radiation-sensitive compound, and the like. Hereinafter, each component will be described in detail.

((A) Semiconductor Nanoparticles) (A) The semiconductor nanoparticle has a nanocrystal containing a semiconductor substance. (A) The semiconductor nanoparticle preferably has a ligand covering at least a part of the nanocrystal. In addition, the term "semiconductor nanoparticle" can be a particle containing a semiconductor and having an average particle diameter of 1 nm or more and 1,000 nm or less. The so-called average particle diameter refers to the arithmetic average of the diameters of 20 arbitrarily selected particles measured using a transmission electron microscope (Transmission Electron Microscope, TEM). In addition, the above-mentioned diameter refers to the average value ((long diameter + short diameter)/2) of the long diameter and the short diameter (diameter orthogonal to the long diameter) (hereinafter, the average particle diameter is the same).

(Nano Crystals) Nanocrystals are crystals containing semiconductor materials. Examples of materials constituting the nanocrystal include compounds containing group 2 elements, group 11 elements, group 12 elements, group 13 elements, group 14 elements, group 15 elements, and group 16 elements, and combinations thereof.

Examples of the element include: Be (beryllium), Mg (magnesium), Ca (calcium), Sr (strontium), Ba (barium), Cu (copper), Ag (silver), Au (gold), Zn (Zinc), B (boron), Al (aluminum), Ga (gallium), In (indium), Tl (thallium), C (carbon), Si (silicon), Ge (germanium), Sn (tin), N (Nitrogen), P (phosphorus), As (arsenic), Sb (antimony), Bi (bismuth), O (oxygen), S (sulfur), Se (selenium), Te (tellurium), Po (polonium), etc.

The nanocrystal preferably contains at least two elements selected from the group consisting of group 2 elements, group 11 elements, group 12 elements, group 13 elements, group 14 elements, group 15 elements, and group 16 elements. In addition, the nanocrystal preferably contains a group 13 element (Al, Ga, In, etc.), and more preferably contains In.

Specifically, as semiconductor materials constituting nanocrystals, for example, BN, BP, BAs, AlN, AlP, AlAs, GaN, GaAs, GaSb, InN, InP, InAs, InSb, etc. can be cited. The semiconductor substance is preferably a compound of a group 13 element (Al, Ga, In, etc.) and a group 15 element (N, P, As, etc.), and more preferably InP.

The nanocrystal may be a homogeneous structure type containing one compound, or may be a core-shell type containing two or more compounds. Core-shell type nanocrystals are composed of a certain compound forming a core structure and other types of compounds covering the core structure. For example, by using a semiconductor with a larger band gap to cover the semiconductor of the nucleus, excitons (electron-hole pairs) generated by light excitation can be enclosed in the nucleus. As a result, the probability of non-radiative transitions on the surface of the nanocrystal is reduced, and the fluorescence quantum yield is improved.

In the case of a core-shell type nanocrystal, the core preferably contains selected from group 2 elements, 11 group elements, 12 group elements, 13 group elements, 14 group elements, 15 group elements and 16 group elements. A semiconductor substance of at least two elements in the group. Furthermore, the core is more preferably a semiconductor substance that is a compound of a group 13 element and a group 15 element, or a semiconductor substance containing In, and particularly preferably InP. On the other hand, the shell is preferably a compound containing group 12 elements (Zn, Cd, etc.) and group 16 elements (S, Se, etc.), and more preferably ZnS.

Examples of core-shell nanocrystals include InP/ZnS, InP/ZnSe, CuInS ₂ /ZnS, (ZnS/AgInS ₂ ) solid solution/ZnS, and the like, and InP/ZnS is preferred. Furthermore, the InP/ZnS is a nanocrystal with InP as the core and ZnS as the shell (other expressions are also the same). In addition, as core-shell type nanocrystals, there are also core/multilayer shell types, such as InP/ZnSe/ZnS, InP/GaP/ZnS, etc. In addition, in the example of each core/multilayer shell type, InP is a core, and the others are shells. Among these core/multilayer shell type nanocrystals, InP/ZnSe/ZnS is preferred.

As a method of obtaining nanocrystals, for example, a known method such as thermal decomposition of an organometallic compound in a coordination organic solvent can be utilized. In addition, core-shell nanocrystals can be obtained, for example, by the following methods: after a homogeneous core is formed by reaction, a precursor for forming a shell on the surface of the core is added to the reaction system, and after a shell is formed on the surface of the core, Stop the reaction and separate from the solvent. As a method of controlling the average particle size of nanocrystals, for example, a method of adjusting the reaction temperature or reaction time can be cited. Furthermore, commercially available nanocrystals can also be used. In addition, InP/ZnS, which is a core-shell type nanocrystal, can also be synthesized with reference to the method described in the technical document "Chemistry of Materials 2015, 27, 4893-4898", for example.

(Ligand) The ligand coats at least a part of the nanocrystal. The ligand electrostatically stabilizes the surface of the nanocrystal.

The ligand preferably has a group x, and the group x is a carboxyl group (-COOH), a thiol group (-SH), a phosphine group (-PO(OH) ₂ ), an amide group (-CONR ₂ or -CONCOR). : R is each independently a hydrogen atom or a hydrocarbon group) or a combination of these. The plurality of groups may be ionic (e.g., -COO ^-) state exists. The radical x is well adsorbed on the surface of the nanocrystal, so it can exhibit good dispersibility. Among the groups x, a carboxyl group and a thiol group are preferred, and a thiol group is more preferred.

(First ligand) The ligand is preferably a first ligand having the group x and further a group y, and the group y is an ether group (-O-), an ester group (-COO-), or a silicon An oxyalkyl group (-SiR ₂ -O-: R is each independently a hydrogen atom or a hydrocarbon group) or a combination of these. The group y is a group that exhibits good dispersibility with respect to the (F) dispersion medium, especially the polar dispersion medium. Among the groups y, ether groups and ester groups are preferred, and ether groups are more preferred.

The first ligand is preferably one represented by the following formula (4).

[化1]

In the formula (4), X is a carboxyl group, a group represented by the following formula (a), a group represented by the following formula (b), a thiol group, a phosphinyl group, or an amide group. Y is a single bond, an oxygen atom or a sulfur atom. Z is an ether group (oxygen atom), an ester group or a siloxyalkyl group. R ⁶ is a divalent chain hydrocarbon group having 1 to 5 carbons. R ⁷ is a monovalent chain hydrocarbon group having 1 to 8 carbons. r is a natural number. When r is 2 or more, a plurality of R ⁶ and Z may be the same or different.

[化2]

In formulas (a) and (b), * represents the bonding site with other sites.

The X is preferably a carboxyl group, a group represented by the formula (a), a group represented by the formula (b), and a thiol group, and more preferably a thiol group.

The Y is preferably a single bond and a sulfur atom, preferably a single bond. In addition, when X is a thiol group, a phosphine group, or an amide group, Y is preferably a single bond.

The Z is preferably an ether group and an ester group, and more preferably an ether group. Furthermore, when Z is an ether group, -(R ⁶ -Z) _r -R ^{7 in} formula (1) forms a polyoxyalkylene chain.

Examples of the divalent chain hydrocarbon group having 1 to 5 carbon atoms represented by R ⁶ include methanediyl, ethane-1,2-diyl, propane-1,2-diyl, and propane-1, 3-diyl, butane-1,2-diyl, butane-1,3-diyl and other alkanediyl groups; ethylene-1,2-diyl and other alkenediyl groups. R ^{6 is} preferably a divalent chain hydrocarbon group having 2 to 4 carbons, and more preferably a divalent chain hydrocarbon group having 2 carbons. In addition, R ^{6 is} also preferably an alkanediyl group, most preferably an ethane-1,2-diyl group.

Examples of the monovalent chain hydrocarbon group having 1 to 8 carbon atoms represented by R ⁷ include alkyl groups such as methyl, ethyl, and propyl; alkenyl groups such as vinyl and propenyl groups; and alkynyl groups such as ethynyl groups. , Preferably an alkyl group. In addition, ^{the carbon number of R 7} is preferably 5 or less, more preferably 3 or less, and even more preferably 1. That is, R ^{7 is} most preferably a methyl group. When ^{the carbon number of R 7} is small, the dispersibility in a polar dispersion medium is further improved.

The upper limit of r in the formula (4) is, for example, 500, preferably 50. The lower limit of r is 1, preferably 2, and more preferably 5.

(Second ligand) As the ligand, a second ligand having the aforementioned group x and further having a hydrocarbon group (group z) having 6 to 20 carbon atoms can also be used. The group z is a group that exerts good dispersibility especially for non-polar dispersion media. Therefore, by using the first ligand and the second ligand together, in a dispersion medium in which a polar dispersion medium and a non-polar dispersion medium coexist, (A ) The dispersibility of semiconductor nanoparticles is further improved. In addition, by using the second ligand, the compatibility with other components when forming the wavelength conversion film can also be improved.

The group x of the second ligand is the same as the group x of the first ligand, and is a group that can be well adsorbed on the surface of the nanocrystal. The group x of the second ligand is preferably a carboxyl group and a thiol group, and more preferably a thiol group.

Examples of the hydrocarbon group having 6 to 20 carbon atoms of the group z include aliphatic hydrocarbon groups such as alkyl, alkenyl, alkynyl, and cycloalkyl groups, or aromatic hydrocarbon groups such as phenyl and naphthyl groups. Aliphatic hydrocarbon groups are preferred, and more preferred Is an alkyl group. The lower limit of the carbon number of the group z is preferably 8, and more preferably 10. On the other hand, the upper limit of the carbon number is preferably 18, more preferably 16.

The first ligand and the second ligand can be coordinated on the surface of the nanocrystal by a previously known method. These ligands are used when synthesizing nanocrystals. They can be ligands attached (coordinated) to the surface of the nanocrystals, or they can be coordinated on the surface of the nanocrystals through ligand exchange after the synthesis of nanocrystals. By. Among them, even through ligand exchange, the ligand is not completely exchanged, and sometimes the original ligand and the new ligand coexist. That is, in the case where the ligand exchange with the first ligand is performed after synthesizing the nanocrystal to which the second ligand is coordinated, the first ligand and the second ligand are usually coordinated on the surface of the nanocrystal. The state of both.

The lower limit of the content of the first ligand relative to the total content of the first ligand and the second ligand is preferably 30% by mass, more preferably 50% by mass, and still more preferably 60% by mass. In addition, the upper limit of the content of the first ligand relative to the total content of the first ligand and the second ligand may be 99% by mass or 90% by mass. If the content of the first ligand is within the above range, especially above the lower limit, the affinity with the (D) polymer or (F) dispersion medium, etc. becomes good, and as a result, a better fluorescence quantum yield can be exhibited Or dispersion characteristics. In addition, similarly, the content of the first ligand in all the ligands contained in the (A) semiconductor nanoparticle is also preferably within the above-mentioned range. In addition, the content of ligands such as the first ligand in the (A) semiconductor nanoparticle can be measured by the method described in the below-mentioned Examples.

(A) The lower limit of the average particle diameter of semiconductor nanoparticles is preferably 0.5 nm, more preferably 1.0 nm. In addition, the upper limit of the average particle diameter is preferably 20 nm, more preferably 10 nm. By setting the average particle diameter to be greater than or equal to the above lower limit, the stability of the fluorescent characteristics of the semiconductor nanoparticle is improved. On the other hand, by setting the average particle size to the upper limit or less, the quantum confinement effect can be sufficiently obtained, and the fluorescence characteristics are improved. In addition, by setting the average particle diameter to be equal to or less than the above upper limit, better dispersion stability can be exhibited.

Furthermore, (A) the wavelength region of the fluorescence of the semiconductor nanoparticle can be controlled by appropriately selecting the constituent material or the average particle size of the nanocrystal. In addition, the shape of the nanocrystal is not particularly limited, and may be, for example, a spherical shape, a rod shape, a disc shape, or other shapes, and a spherical shape and a rod shape are preferable. If the semiconductor nanoparticle is spherical, the surface energy of the particle becomes small, so the dispersion stability can be improved. In addition, if the semiconductor nanoparticle is in a rod shape, it is possible to increase the light utilization efficiency by polarizing light emission.

(A) The lower limit of the content of the semiconductor nanoparticle in all solid components of the cured film forming composition is preferably 1% by mass, more preferably 5% by mass, and still more preferably 8% by mass. By setting the content of the (A) semiconductor nanoparticle to be greater than or equal to the above lower limit, sufficient light emission in the obtained wavelength conversion film can be achieved. On the other hand, the upper limit of the content is preferably 50% by mass, more preferably 30% by mass, and still more preferably 20% by mass. By setting the content of the (A) semiconductor nanoparticle to the upper limit or less, the dispersion stability, coatability, etc. can be further improved. In addition, the term "solid content" refers to components other than the (F) dispersion medium.

((B) Urethane (meth)acrylate) (B) Urethane (meth)acrylate has a some polymerizable group. The urethane (meth)acrylate refers to a (meth)acrylate having a urethane bond (-NHCOO-). The urethane (meth)acrylate has a (meth)acryloyl group as a polymerizable group, and may further have other polymerizable groups such as an epoxy group and a vinyl group. The so-called (meth)acryloyl group refers to an allyl group (-CO-CH=CH ₂ ) or a methacryloyl group (-CO-C(CH ₃ )=CH ₂ ), preferably an allyl group.

(B) The lower limit of the number of polymerizable groups of the urethane (meth)acrylate may be 2, preferably 4, more preferably 6, still more preferably 8, still more preferably 9, and further 10 is particularly preferred, and 12 is particularly preferred. On the other hand, the upper limit of the number of the polymerizable group is, for example, 30, preferably 24, and more preferably 18. By using (B) urethane (meth)acrylate having such a number of polymerizable groups, coatability, dispersion stability, and fluorescence performance of the obtained wavelength conversion film become better .

(B) Urethane (meth)acrylate preferably has an isocyanuric acid structure, a triazine structure, or a combination of these. When (B) urethane (meth)acrylate has such a structure, coatability, dispersion stability, and fluorescence performance of the obtained wavelength conversion film become better. Examples of the isocyanuric acid structure include the structure represented by the following formula (5). Examples of the triazine structure include structures represented by the following formula (6).

[化3]

In equations (5) and (6), * represents the bonding site with other sites.

(B) The lower limit of the molecular weight of the urethane (meth)acrylate is, for example, 300, preferably 600, more preferably 1,000, and still more preferably 1,800. On the other hand, the upper limit of the molecular weight is, for example, 10,000, preferably 6,000, more preferably 5,000, and still more preferably 4,000. By using (B) urethane (meth)acrylate having a molecular weight in the above-mentioned range, coatability, dispersion stability, and fluorescent performance of the obtained wavelength conversion film become better. When (B) urethane (meth)acrylate is a polymer, the weight average molecular weight of the polymer is preferably within the range of the above-mentioned numerical value. The method for measuring the weight average molecular weight of the polymer is the same as the method described in the examples.

(B) Preferred forms of urethane (meth)acrylate include compounds represented by the following formula (1).

[化4]

In the formula (1), R ¹ is an m-valent organic group having 1 to 60 carbon atoms. A plurality of R ^{2 is} each independently a group containing one or more (meth)acryloyl groups. m is 2 or 3. The organic group refers to a group containing one or more carbon atoms.

Examples of the m-valent organic group having 1 to 60 carbon atoms represented by R ¹ include an m-valent hydrocarbon group, a group in which part or all of the hydrogen atoms of the m-valent hydrocarbon group are substituted with substituents, and the carbon of the m-valent hydrocarbon group- Among the carbons, CO, CS, O, S, NR', or a group formed by combining two or more of these, and the like are included. R'is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a group containing a combination of these, and the like. Examples of the substituent include a hydroxyl group, a carboxyl group, an amino group, a cyano group, a nitro group, and a sulfonamide group. Examples of groups formed by combining two or more of CO, CS, O, S, and NR' include -COO-, -CONR'-, -NR'COO-, and the like.

The lower limit of the carbon number of the organic group represented by R ¹ is preferably 4, more preferably 10, and still more preferably 16. On the other hand, the upper limit of the carbon number is preferably 50, more preferably 40, and still more preferably 30.

m is preferably 3.

The m-valent organic group having 1 to 60 carbon atoms represented by R ¹ is preferably a group containing a heterocyclic structure, and more preferably a group containing a nitrogen-containing heterocyclic structure. Examples of the heterocyclic structure containing nitrogen include a triazine structure and an isocyanuric acid structure. The m-valent organic group having 1 to 60 carbon atoms represented by R ¹ is preferably a group containing only a nitrogen-containing heterocyclic structure, and a group containing a nitrogen-containing heterocyclic structure and a hydrocarbon group (more preferably a chain hydrocarbon group).

Preferable R ¹ includes groups represented by the following formula (3-1) and formula (3-2), and particularly preferably a group represented by formula (3-1). In addition, when R ^{1 is} represented by the following formula (3-1) or formula (3-2), m is 3.

[化5]

In formula (3-1) and formula (3-2), a plurality of R ^{5 is} each independently a single bond or a C 1-12 alkanediyl group.

The R ^{5 is} preferably an alkanediyl group. The lower limit of the carbon number of the alkanediyl group is preferably 2, and more preferably 4. On the other hand, the upper limit of the carbon number is preferably 10, more preferably 8. The alkanediyl group may be either linear or branched, and is preferably linear.

R ² is a group containing one or more (meth)acryloyl groups, and is preferably connected to formula (1) via a multivalent organic group corresponding to the number of one or more (meth)acryloyloxy groups. The group to which the oxygen atom contained in the urethane bond in is bonded. The number of (meth)acrylic groups contained in the group represented by R ² is not particularly limited, and the lower limit is preferably 2, and more preferably 3. On the other hand, the upper limit is preferably 10, more preferably 5.

Preferable R ² includes a group represented by the following formula (2).

[化6]

In formula (2), R ³ is a single bond or an alkanediyl group having 1 to 3 carbon atoms. R ⁴ is a (meth)acryloyl group. n is 1 or 2. p is 0 or 1. q is an integer of 1-3.

R ^{3 is} preferably an alkanediyl group having 1 to 3 carbon atoms, more preferably a methanediyl group.

R ^{4 is} preferably an acryloyl group.

n is preferably 2. p is preferably 1. q is preferably 3.

(B) Commercial products of urethane (meth)acrylate include: U-6HA, UA-1100H, U-6LPA, U-15HA, U-6H of Shinnakamura Chemical Industry Co., Ltd. , U-10HA, U-10PA, UA-53H, UA-33H; UN-904 of Negami Industry Co., Ltd.; UA-306H, UA-306T, UA-306I, UA-510H of Kyoeisha Chemical Co., Ltd. ; BASF (BASF) La Roma (Laromer) UA-9048, UA-9050, PR9052; Daicel-allnex (stock) EBECRYL 220, 5129, 8301 KRM8200, 8200AE, 8452, etc.

As the lower limit of the content of (B) urethane (meth)acrylate, relative to 100 parts by mass of (A) semiconductor nanoparticle, it is preferably 50 parts by mass, more preferably 100 parts by mass, and still more preferably 200 parts by mass. By setting the content of (B) urethane (meth)acrylate to the above lower limit or more, good curability and the like can be exhibited. On the other hand, the upper limit of the content is preferably 1,000 parts by mass, more preferably 500 parts by mass, and still more preferably 400 parts by mass. By setting the content of (B) urethane (meth)acrylate below the above upper limit, the content ratio of (A) semiconductor nanoparticle is increased, etc., by which better fluorescent performance can be expressed Wait.

((C) Light diffusion particles) (C) The light diffusion particle is a component that increases the amount of light incident on the semiconductor nanoparticle by light diffusion to increase the fluorescence quantum yield (wavelength conversion efficiency). When the cured film forming composition contains (C) light diffusion particles, the fluorescence quantum yield and the like can be further improved. Furthermore, light diffusion particles are different from semiconductor nanoparticles in that they do not emit fluorescence.

(C) The light diffusion particles preferably include metal oxides, and more preferably metal oxide particles. Among the metal oxides, Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , Indium Tin Oxide (ITO) (doped Indium oxide with tin), indium zinc oxide (Indium Zinc Oxide, IZO) (indium oxide doped with zinc), Antimony Tin Oxide (ATO) (tin oxide doped with antimony), zinc aluminum oxide (Aluminum Zinc Oxide, AZO) (aluminum-doped zinc oxide), Nb ₂ O ₃ , SnO, CeO ₂ , MgO or a combination of these, more preferably titanium oxide (TiO ₂ and Ti ₃ O ₅ ) and oxidation Cerium (CeO ₂ ). Titanium oxide has an excellent ability to scatter the excitation light, and the excitation light is more easily incident on the quantum dots.

In addition, (C) the light diffusion particles are preferably particles having titanium oxide (TiO ₂ and Ti ₃ O _{5 ) and aluminum oxide (Al 2} O ₃ ) covering at least a part of the surface of the titanium oxide. Titanium oxide is a material that strongly functions as a photocatalyst. Therefore, the wavelength conversion film may be degraded by light, and the wavelength conversion function of (A) semiconductor nanoparticles may be reduced. Therefore, when the (C) light diffusion particles are titanium oxide, by coating the surface with aluminum oxide, the photocatalyst function can be reduced and a good fluorescence quantum yield can be obtained.

(C) The lower limit of the average particle diameter of the light diffusion particles is preferably 5 nm, more preferably 10 nm, and still more preferably 30 nm. By setting the average particle diameter of (C) light-diffusing particles to be equal to or greater than the above lower limit, sufficient light diffusibility can be exhibited. On the other hand, the upper limit of the average particle diameter is preferably 500 nm, more preferably 300 nm, and still more preferably 250 nm. By setting the average particle diameter of the (C) light-diffusing particles to be equal to or less than the above upper limit, sufficient light diffusibility, dispersibility, coatability, etc. can be exhibited.

The lower limit of the content of (C) light diffusion particles is preferably 10 parts by mass, and more preferably 50 parts by mass relative to 100 parts by mass of (A) semiconductor nanoparticle. By setting the content of (C) light-diffusing particles to be greater than or equal to the above-mentioned lower limit, sufficient light diffusibility can be exerted and the fluorescence quantum yield can be improved. On the other hand, the upper limit of the content is preferably 500 parts by mass, more preferably 300 parts by mass, and still more preferably 200 parts by mass. By setting the content of the (C) light-diffusing particles to be equal to or less than the upper limit, the dispersibility or coatability is further improved, and thereby the fluorescent quantum yield can be further improved.

((D) Polymer) (D) The polymer generally functions as a binder resin that becomes the base material of the cured film obtained. Furthermore, (B) urethane (meth)acrylate is not included in (D) polymer. (D) A part or all of the polymer may also function as a dispersant. When the cured film forming composition further contains the (D) polymer, the deterioration of the (A) semiconductor nanoparticle accompanying heating in the obtained wavelength conversion film is suppressed, and the fluorescent performance and the like can be further improved. (D) The polymer includes acrylic resin, polyimide, polysiloxane, aromatic polyether, novolac resin, etc. Among them, acrylic resin is preferred.

(D) The polymer preferably has an acidic group. Since (D) the polymer has an acidic group, the dispersion stability is improved, and it also exhibits good alkali solubility. In the case where the (D) polymer is alkali-soluble, good patterning can be performed by an alkaline developer or the like. Examples of the acidic group include a carboxyl group, a sulfonic acid group, a phosphoric acid group, and a phenolic hydroxyl group, and a carboxyl group is preferred. Furthermore, the hydrogen atom in the acidic group may be substituted by a metal atom or the like, or may be dissociated.

(D) The polymer preferably has a side chain containing an acidic group, and more preferably has a side chain having 5 to 15 carbon atoms containing an acidic group. The so-called side chain refers to the part of the autonomous chain branch, that is, the monovalent group. When the (D) polymer has such a side chain, the affinity with the (A) semiconductor nanoparticle becomes better, and as a result, the dispersibility and the like are particularly improved. The lower limit of the carbon number of the side chain is preferably 6, and more preferably 7. The upper limit of the carbon number is more preferably 13. The acidic group is preferably located at the end of the chain side chain on the opposite side to the main chain side.

The side chain containing an acidic group is preferably a group represented by *-COO-R-COOH (R is a divalent organic group with 3 to 13 carbon atoms; * represents a bonding site to the main chain). R is preferably a divalent hydrocarbon group and a group containing -COO- between carbon and carbon of the hydrocarbon group, and more preferably a group containing -COO- between carbon and carbon of the divalent hydrocarbon group. R may contain multiple -COO-. The lower limit of the carbon number of R is preferably 4, more preferably 5. The upper limit of the carbon number of R is preferably 11.

(D) The polymer preferably contains a structural unit having an acidic group, and more preferably contains a structural unit having a side chain containing an acidic group. Monomers that provide such structural units include, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and phthalic acid mono[2 -(Meth)acryloyloxyethyl) ester, succinic acid mono(2-propenyloxyethyl) ester, succinic acid mono(2-methacryloyloxyethyl) ester, ω -Carboxy-polycaprolactone monoacrylate, hexahydrophthalic acid mono(2-methacryloxyethyl) ester, etc. Among these, phthalic acid mono[2-(meth)acryloyloxyethyl] ester, succinic acid mono(2-acryloyloxyethyl) ester, succinic acid mono(2 -Methacryloxyethyl) ester, ω-carboxy-polycaprolactone monoacrylate, hexahydrophthalic acid mono(2-methacryloxyethyl) ester, etc. Provide carbon number 5 to 15 side chains.

(D) The lower limit of the content of the acidic group-containing structural unit in the polymer is preferably 5% by mass, and more preferably 10% by mass. In addition, the upper limit of the content ratio is preferably 50% by mass, more preferably 40% by mass, and particularly preferably 30% by mass. If it is in the range of the said numerical value, alkali developability and dispersion stability will be excellent.

(D) The polymer preferably has a chain hydrocarbon group having 4 to 20 carbon atoms. Since the (D) polymer has a chain hydrocarbon group having 4 to 20 carbon atoms, the dispersion stability and coatability are improved, and the fluorescent performance of the obtained wavelength conversion film also becomes better. The chain hydrocarbon group is preferably an alkyl group. In addition, the lower limit of the carbon number of the chain hydrocarbon group is preferably 6, and more preferably 8. On the other hand, the upper limit of the carbon number is preferably 16, and more preferably 12.

(D) The polymer preferably contains a structural unit having a chain hydrocarbon group having 4 to 20 carbon atoms. Monomers that provide such structural units include, for example, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, Alkyl (meth)acrylates such as lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, and the like.

(D) The lower limit of the content of the structural unit containing the chain hydrocarbon group having 4 to 20 carbon atoms in the polymer is preferably 5 mass%, more preferably 10 mass%. In addition, the upper limit of the content ratio is preferably 40% by mass, more preferably 30% by mass.

(D) The polymer preferably contains a structural unit having a hydrocarbon group other than the chain hydrocarbon group having 4 to 20 carbon atoms, and more preferably contains a structural unit having a cyclic hydrocarbon group. Examples of the cyclic hydrocarbon group include an aryl group or a cycloalkyl group, and a cycloalkyl group is preferred. The lower limit of the carbon number of the hydrocarbon group other than the chain hydrocarbon group having 4 to 20 carbons may be 1, preferably 2, and more preferably 4. In addition, the upper limit of the carbon number is preferably 20, more preferably 12, and still more preferably 8. Monomers that provide such structural units include alkyl (meth)acrylates having alkyl groups having 1 to 3 carbon atoms, cycloalkyl (meth)acrylates, aryl (meth)acrylates, etc. The (meth)acrylate is preferably a cycloalkyl (meth)acrylate and an aryl (meth)acrylate, and more preferably a cycloalkyl (meth)acrylate. Cycloalkyl (meth)acrylates include: cyclohexyl (meth)acrylate, tricyclo[5.2.1.0 ^2,6 ]decane-8-yl (meth)acrylate, isopropyl (meth)acrylate Borneol esters and so on.

(D) The lower limit of the content of the structural unit containing a hydrocarbon group other than the chain hydrocarbon group having 4 to 20 carbon atoms in the polymer is preferably 10% by mass, and more preferably 30% by mass. In addition, the upper limit of the content ratio is preferably 80% by mass, more preferably 70% by mass, and still more preferably 60% by mass.

In addition, in the polymer (D), the lower limit of the total content ratio of the structural unit containing an acidic group, the structural unit having a chain hydrocarbon group having 4 to 20 carbon groups, and the structural unit having a cyclic hydrocarbon group is sometimes preferable. It is 80% by mass, and sometimes is more preferably 90% by mass, 95% by mass, and further 99% by mass. (D) The polymer preferably contains both a structural unit having an acidic group and a structural unit having a chain hydrocarbon group having 4 to 20 carbon atoms.

(D) The polymer may further have other structural units. Monomers that provide such structural units include: unsaturated dicarboxylic acid diesters, maleimide compounds, unsaturated aromatic compounds, conjugated dienes, unsaturated compounds having a tetrahydrofuran skeleton, and other unsaturated compounds Wait.

The (D) polymer having each structural unit can be obtained by polymerizing a monomer that provides each structural unit by a known method.

(D) The lower limit of the weight average molecular weight (Mw) of the polymer is preferably 3,000, more preferably 6,000, and still more preferably 10,000. On the other hand, the upper limit of the weight average molecular weight (Mw) is preferably 50,000, more preferably 30,000, and still more preferably 20,000. By setting the weight average molecular weight (Mw) of the (D) polymer in the above-mentioned range, dispersion stability, coating properties, and the like can be further improved.

In addition, the measuring method of the weight average molecular weight (Mw) in this specification is described in an Example.

The lower limit of the content of the (D) polymer is preferably 10 parts by mass, more preferably 100 parts by mass, and still more preferably 200 parts by mass relative to 100 parts by mass of the (A) semiconductor nanoparticle. On the other hand, the upper limit of the content is preferably 1,000 parts by mass, more preferably 500 parts by mass. By setting the content of the (D) polymer in the above range, the dispersion stability and coating properties and the fluorescence performance of the obtained wavelength conversion film can be made more favorable.

((E) Antioxidant) (E) Antioxidants can suppress the oxidative degradation of (A) semiconductor nanoparticles, (D) polymers, etc. caused by heat or light irradiation. Therefore, when the composition for forming a cured film further contains (E) an antioxidant, the fluorescence quantum yield of the wavelength conversion film obtained by heat treatment or the like can be further improved.

(E) Antioxidants include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, benzophenone-based antioxidants, and the like. Among these, phenolic antioxidants are preferred. By using a phenolic antioxidant, the fluorescence quantum yield of the wavelength conversion film obtained by heat treatment or the like can be further improved.

Examples of phenolic antioxidants include 2,4,6-tris (3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene, 2,4-bis-(normal Octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, pentaerythritol tetrakis[3-(3,5-di-third Butyl-4-hydroxyphenyl)propionate] (for example, "Irganox 1010" from BASF), 2,6-di-tert-butyl-4-nonylphenol , Thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (for example, "Irganox (Irganox) from BASF) 1035"), 2,2'-methylenebis-(6-(1-methylcyclohexyl)-p-cresol), N,N-hexamethylenebis(3,5-di-tert 4-hydroxy-hydrocinnamylamine), 2,5-di-tertiary butyl hydroquinone, 2,5-di-tertiary amyl-hydroquinone, 2,4-dimethyl -6-(1-Methylcyclohexyl)-phenol, 6-tertiary butyl-o-cresol, 6-tertiary butyl-2,4-xylenol, 2,4-dimethyl-6- (1-methylpentadecyl)phenol, 2,4-bis(octylthiomethyl)-o-cresol, 2,4-bis(dodecylthiomethyl)-o-cresol, ethylene Bis(oxyethylene) bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (for example, BASF's "Ironos ( Irganox) 245"), 3,9-bis[2-[3-(tert-butyl-4-hydroxy-5-methylphenyl)propanyloxy]-1,1-dimethylethyl ]-2,4,8,10-Tetraoxaspiro[5.5]undecane (for example, "Sumilizer GA-80" of Sumitomo Chemical Company), triethylene glycol bis[3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (for example, Adekastab AO-70 from ADEKA), 2- Tertiary amylphenol, 2-tertiary butylphenol, 2,4-di-tertiary butylphenol, 1,1,3-tris-(2'-methyl-4'-hydroxy-5'-th Tributylphenyl)-butane, 4,4'-butylene-bis-(2-tert-butyl-5-methylphenol) and the like.

Examples of phosphorus-based antioxidants include tris(isodecyl) phosphite, tris(tridecyl) phosphite, phenyl isooctyl phosphite, phenyl isodecyl phosphite, and phenyl phosphite Di(tridecyl)ester, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite ) Ester, 4,4'-isopropylidene diphenol alkyl phosphite, trinonylphenyl phosphite, tris-dinonylphenyl phosphite, tris(2,4-bis- Tertiary butyl phenyl) ester, tris(biphenyl) phosphite, distearyl pentaerythritol diphosphite, di(2,4-di-tertiary butylphenyl) pentaerythritol diphosphite, Di(nonylphenyl) pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, tetra-tridecyl 4,4'-butylene bis(3-methyl-6-tertiary butylphenol) )Diphosphite, hexa-tridecyl 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, 3,5-di- Tributyl-4-hydroxybenzyl phosphite diethyl ester, 1,3-bis(diphenoxyphosphinooxy)-benzene, phosphite ethyl bis(2,4-di-tert-butyl) 6-methylphenyl) ester, tri-o-tolylphosphine and the like.

The lower limit of the content of (E) antioxidant is preferably 10 parts by mass, and more preferably 30 parts by mass relative to 100 parts by mass of (A) semiconductor nanoparticle. By setting the content of (E) antioxidant to be equal to or higher than the lower limit, sufficient antioxidant performance can be exerted and the fluorescence quantum yield can be improved. On the other hand, the upper limit of the content is preferably 200 parts by mass, more preferably 100 parts by mass. By setting the content of (E) antioxidants below the above upper limit, the content ratio of (A) semiconductor nanoparticles is increased, etc., whereby better fluorescent performance and the like can be expressed.

((F) Dispersion medium) By further containing the (F) dispersion medium in this cured film forming composition, the uniform dispersibility or coatability of each component is improved. (F) The dispersion medium includes a polar dispersion medium and a non-polar dispersion medium. From the viewpoint of further improving dispersion stability, etc., it is preferable to include a polar dispersion medium.

Examples of polar dispersion media include alcohols, alkyl ethers of polyhydric alcohols, monoalkyl ether monoesters of polyhydric alcohols, hydroxycarboxylic acid esters, carboxylic acids, ethers, ketones, amines, and amines. Class or combination of these.

Examples of alcohols include monoalcohols such as methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, and isopropanol; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and triethyl Polyols such as diol and tripropylene glycol.

Examples of the alkyl ethers of polyhydric alcohols include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monopropyl ether, and ethylene glycol. Monobutyl ether, propylene glycol monobutyl ether and other polyol monoalkyl ethers; ethylene glycol dimethyl ether, propylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol diethyl ether, ethylene glycol dipropyl ether, propylene glycol dipropylene Polyalkyl ethers of polyhydric alcohols such as ether, ethylene glycol dibutyl ether, and propylene glycol dibutyl ether.

Examples of monoalkyl ether monoesters of polyhydric alcohols include esters of monoalkyl ethers of polyhydric alcohols and carboxylic acids, and esters of monoalkyl ethers of polyhydric alcohols and acetic acid are preferred. Specific examples of monoalkyl ether monoesters of polyhydric alcohols include: ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and propylene glycol monoethyl ether acetate Ester, ethylene glycol monopropyl ether acetate, propylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monobutyl ether acetate, etc.

Examples of hydroxycarboxylic acid esters include methyl glycolate, ethyl glycolate, methyl lactate, ethyl lactate, methyl hydroxypropionate, ethyl hydroxypropionate, methyl hydroxybutyrate, and hydroxybutyrate. Ethyl and so on.

Examples of carboxylic acids include formic acid, acetic acid, and the like.

Examples of ethers include cyclic or chain alkyl ethers and the like. Specific examples of ethers include, for example, tetrahydrofuran, 1,4-dioxane, dimethoxyethane, diethyl ether, dimethyl ether, and the like.

As ketones, acetone, methyl ethyl ketone, etc. are mentioned, for example. Ketones may have a substituent, and among them, hydroxy ketones are preferred. Examples of hydroxy ketones include α-hydroxyacetone, 1-hydroxy-2-butanone, 1-hydroxy-2-pentanone, 3-hydroxy-2-butanone, and 3-hydroxy-3-pentanone. Hydroxy ketones; 4-hydroxy-2-butanone, 3-methyl-4-hydroxy-2-butanone, diacetone alcohol, 4-hydroxy-5,5-dimethyl-2-hexanone, etc. β- Hydroxy ketones; 5-hydroxy-2-pentanone, 5-hydroxy-2-hexanone, etc.

Examples of amides include N,N-dimethylformamide, N,N-dimethylacetamide, and the like.

Examples of amines include triethylamine and pyridine.

Among the polar dispersion media, alkyl ethers of polyhydric alcohols and monoalkyl ethers and monoesters of polyhydric alcohols are preferable, and monoalkyl ethers and monoesters of polyhydric alcohols are more preferable.

Examples of the non-polar dispersion medium include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, and hydrocarbons such as aliphatic hydrocarbons such as hexane and cyclohexane.

The lower limit of the content of the polar dispersion medium in the (F) dispersion medium is preferably 30% by mass, more preferably 50% by mass, still more preferably 70% by mass, and still more preferably 90% by mass. The content of the polar dispersion medium in the (F) dispersion medium may be substantially 100% by mass.

(F) The content of the dispersion medium is not particularly limited, and the lower limit of the content of the (F) dispersion medium in the cured film forming composition is preferably 20% by mass, more preferably 30% by mass. On the other hand, the upper limit of the content is preferably 90% by mass, more preferably 80% by mass. By setting the content of the (F) dispersion medium in the above range, dispersion stability, coatability, etc. can be made more favorable.

((G) Radiation-sensitive compound) The composition for forming a cured film may further contain (G) a radiation-sensitive compound. In this case, radiation sensitivity can be imparted to the composition for forming a cured film.

(G) Radiation-sensitive compounds include, for example, radiation-sensitive radical polymerization initiators, radiation-sensitive acid generators, radiation-sensitive base generators, and combinations of these. Among these, since the curing reaction of (B) urethane (meth)acrylate can be promoted by irradiation with radiation, it is preferable to use a radiation-sensitive radical polymerization initiator.

Specific examples of the radiation-sensitive radical polymerization initiator include, for example, O-oxime compounds, α-aminoketone compounds, α-hydroxyketone compounds, and phosphine oxide compounds.

Examples of the O-acetoxime compound include: 1-[9-ethyl-6-(2-methylbenzyl)-9.H.-carbazol-3-yl]-ethane-1 -Ketoxime-O-acetate, 1-[9-ethyl-6-benzyl-9.H.-carbazol-3-yl]-octane-1-ketoxime-O-acetic acid Ester, 1-[9-ethyl-6-(2-methylbenzyl)-9.H.-carbazol-3-yl]-ethane-1-one oxime-O-benzoate , 1-[9-n-butyl-6-(2-ethylbenzyl)-9.H.-carbazol-3-yl]-ethane-1-one oxime-O-benzoate , Ethyl ketone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofurylbenzyl)-9.H.-carbazol-3-yl]-,1-(O-ethyl Oxime), ethyl ketone, 1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzyl)-9.H.-carbazol-3-yl]- ,1-(O-acetyloxime), ethyl ketone, 1-[9-ethyl-6-(2-methyl-5-tetrahydrofurylbenzyl)-9.H.-carbazole-3 -Yl]-,1-(O-acetyloxime), ethyl ketone, 1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3- Dioxolol) methoxybenzyl}-9.H.-carbazol-3-yl]-,1-(O-acetoxime), ethyl ketone, 1-[9-ethyl Base-6-(2-methyl-4-tetrahydrofurylmethoxybenzyl)-9.H.-carbazol-3-yl)-,1-(O-acetyloxime), 1, 2-octanedione-1-[4-(phenylthio)-2-(O-benzyloxime)], ethyl ketone, 1-[9-ethyl-6-(2-methyl Benzyl)-9.H.-carbazol-3-yl]-, 1-(O-acetyloxime) and the like.

As commercially available products of O-acetoxime compounds, for example: NCI-831, NCI-930 (above, manufactured by ADEKA Co., Ltd.); DFI-020, DFI-091 (above, Dadong Chemicals (manufactured by Daito Chemix Co., Ltd.); Irgacure OXE01, OXE02, OXE03 (above, manufactured by BASF), etc.

As the α-amino ketone compound, for example, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butane-1-one, 2-dimethylamine 2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-(4-methylsulfanyl) (Phenyl)-2-morpholinopropan-1-one and the like.

As the α-hydroxy ketone compound, for example, 1-phenyl-2-hydroxy-2-methylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methyl Propan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, etc.

As the phosphine oxide compound, for example, 2,4,6-trimethylbenzyl diphenyl phosphine oxide, bis(2,4,6-trimethylbenzyl)-phenyl oxide Phosphine etc.

As the radiation-sensitive radical polymerization initiator, from the viewpoint of further promoting the curing reaction by radiation, O-acetoxy oxime compounds and acetoxy phosphine oxide compounds are preferred.

As a specific example of the radiation-sensitive acid generator, for example: Diphenyl iodotrifluoromethane sulfonate, diphenyl iodopyrene sulfonate and other iodonium salt-based radiation-sensitive acid generators; Aluminium salt-based radioactive acid generators such as triphenylene trifluoromethane sulfonate and triphenylene hexafluoroantimonate; 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate and other tetrahydrothiophenium salt-based radioactive acids Generator Trifluoromethylsulfonyloxybicyclo[2.2.1]hept-5-endimethylimidimide, succinimidyl trifluoromethanesulfonate and other iminium sulfonates are radiosensitive acid production Agent (5-Propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-octylsulfonyloxyimino-5H- Thiophen-2-ylidene)-(2-methylphenyl)acetonitrile and other oxime sulfonate-based radiation-sensitive acid generators; Quinone diazide compounds such as 1,2-naphthoquinone diazide sulfonate of trihydroxybenzophenone and 1,2-naphthoquinone diazide sulfonate of tetrahydroxybenzophenone.

Specific examples of the radiation-sensitive base generator include, for example, 4-(methylthiobenzyl)-1-methyl-1-morpholinylethane, (4-morpholinylbenzyl) Base)-1-benzyl-1-dimethylaminopropane, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone, N-(2- Nitrobenzyloxycarbonyl)pyrrolidine, 1-(anthraquinone-2-yl)ethylimidazole carboxylate and other radiation-sensitive base generators containing heterocyclic groups; 2-nitrobenzylcyclohexyl carbamate, [[(2,6-dinitrobenzyl)oxy]carbonyl]cyclohexylamine, bis[[(2-nitrobenzyl)oxy]carbonyl ]Hexane-1,6-diamine, triphenylmethanol, o-aminocarboxamide, o-carboxamide, o-carboxamide, hexaamine cobalt(III) tris(triphenylmethyl borate), 1,2-Dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyl triphenyl borate, etc.

As the lower limit of the content of the (G) radiation-sensitive compound, relative to 100 parts by mass of the (A) semiconductor nanoparticle, it is preferably 1 part by mass, more preferably 10 parts by mass, and still more preferably 30 parts by mass. In addition, the upper limit of the content is preferably 200 parts by mass, more preferably 100 parts by mass. By setting the content of the (G) radiation-sensitive compound in the above range, the radiation sensitivity of the cured film forming composition, the hardness of the obtained wavelength conversion film, and the like can be further improved.

(Other ingredients) The composition for forming a cured film may contain other components other than the above-mentioned (A) component to (G) component. As other components, a thermal polymerization initiator, an adhesive auxiliary agent, a storage stabilizer, a polymerizable compound other than a urethane (meth)acrylate, etc. are mentioned. As an upper limit of the content of the other components in the cured film forming composition, with respect to 100 parts by mass of the (A) semiconductor nanoparticle, it is sometimes preferably 10 parts by mass, and sometimes more preferably 1 part by mass.

The composition for forming a cured film can be prepared by a known method. The composition for forming a cured film can be prepared, for example, by mixing (A) semiconductor nanoparticle, (B) urethane (meth)acrylate, and optional components in a (F) dispersion medium.

＜Wavelength conversion film＞ The wavelength conversion film of one embodiment of the present invention is a cured film formed from the cured film forming composition. The wavelength conversion film is obtained from the composition for forming a cured film, and therefore the fluorescence quantum yield is high, and as a result, for example, it can have high color reproducibility. The wavelength conversion film may be patterned or unpatterned. If the wavelength conversion film is patterned, it can be applied to a light-emitting layer useful as a sub-pixel. The method of forming the wavelength conversion film is not particularly limited. For example, it may be a method of curing by radiation irradiation, or a method of curing by heating. Among them, since the composition for forming a cured film is used, even if it is a method of curing by heating, a wavelength conversion film with a high fluorescence quantum yield can be obtained. The specific method of forming the wavelength conversion film will be described later.

This wavelength conversion film is suitable for use as a light-emitting layer of a light-emitting display element. Hereinafter, a preferred embodiment of the light-emitting display element will be described.

<Light-emitting display element> Fig. 1 is a cross-sectional view schematically showing a light-emitting display element 100 according to an embodiment of the present invention. The light-emitting display element 100 has a wavelength conversion substrate 11, which is configured by providing a light-emitting layer 13 (a first light-emitting layer 13a, a second light-emitting layer 13b, and a third light-emitting layer 13c) and a black matrix 14 on a first substrate 12; And the light source substrate 18 is bonded to the wavelength conversion substrate 11 via the adhesive layer 15. The light-emitting layer 13 is a wavelength conversion film according to an embodiment of the present invention.

The first substrate 12 is a transparent substrate, and specific examples will be described later.

The light emitting layer 13 of the wavelength conversion substrate 11 is formed by patterning using the composition for forming a cured film. The light-emitting layer 13 is formed using the composition for forming a cured film. Therefore, the semiconductor nanoparticle has a high fluorescence quantum yield, and can be, for example, a light-emitting layer with high color reproducibility.

The wavelength conversion substrate 11 wavelength-converts the excitation light from the light source 17 of the light source substrate 18 by the semiconductor nano particles contained in each of the light-emitting layers 13 to emit fluorescent light of a desired wavelength. In the wavelength conversion substrate 11, the first light-emitting layer 13a, the second light-emitting layer 13b, and the third light-emitting layer 13c are composed of different semiconductor nanoparticles, and can emit different fluorescence. For example, the wavelength conversion substrate 11 may be configured as follows: the first light-emitting layer 13a converts excitation light into red light, the second light-emitting layer 13b converts excitation light into green light, and the third light-emitting layer 13c converts excitation light into blue light. Colored light.

At this time, the semiconductor nanoparticles contained in each of the first light-emitting layer 13a, the second light-emitting layer 13b, and the third light-emitting layer 13c are selected so as to have desired fluorescent characteristics. Therefore, in the formation of each of the first light-emitting layer 13a, the second light-emitting layer 13b, and the third light-emitting layer 13c of the wavelength conversion substrate 11, for example, three types of cured film formation compositions containing semiconductor nanoparticles with different light-emitting characteristics are prepared.

The lower limit of the average thickness of the light-emitting layer 13 of the wavelength conversion substrate 11 is preferably 100 nm, more preferably 1 μm. In addition, the upper limit of the average thickness is preferably 100 μm. By setting the average thickness to be greater than or equal to the lower limit, particularly the excitation light can be sufficiently absorbed, the light conversion efficiency is improved, and the brightness of the light-emitting display element can be improved.

A black matrix 14 is arranged between the light-emitting layers 13 on the first substrate 12. The black matrix 14 can be formed by using a known light-shielding material and patterning in accordance with a known method. In addition, the black matrix 14 is not an essential component in the wavelength conversion substrate 11, and the wavelength conversion substrate 11 may also be a configuration in which the black matrix 14 is not provided.

The adhesive layer 15 is formed using a known adhesive that transmits ultraviolet light or blue light. Furthermore, the adhesive layer 15 does not need to be provided on the first substrate 12 to cover the entire surface of each light-emitting layer 13 as shown in FIG. 1, and may be provided only on the outer edge of the wavelength conversion substrate 11.

The light source substrate 18 includes a second base material 16 and a light source 17 arranged on the wavelength conversion substrate 11 side of the second base material 16. The light source 17 respectively emits ultraviolet light or blue light as excitation light.

The light source 17 (the first light source 17a, the second light source 17b, the third light source 17c) is not particularly limited, and ultraviolet light-emitting organic EL elements, blue light-emitting organic EL elements, purple light-emitting LED elements, and blue light-emitting LEDs of known structures can be used. The element etc. can be manufactured by a well-known manufacturing method. Here, the ultraviolet light preferably has a main emission peak of 360 nm or more and 435 nm or less, and the blue light preferably has a main emission peak of over 435 nm and 480 nm or less. The light source 17 preferably has directivity in such a manner that each emitted light is irradiated to the opposing light-emitting layer 13.

The light-emitting display element 100 wavelength-converts the excitation light from the first light source 17a by the semiconductor nanoparticle of the first light-emitting layer 13a of the wavelength conversion substrate 11. Similarly, the excitation light from the second light source 17b is wavelength-converted by the semiconductor nanoparticles of the second light-emitting layer 13b of the wavelength conversion substrate 11, and the semiconductor nanoparticles of the third light-emitting layer 13c of the wavelength conversion substrate 11 are used for wavelength conversion. The wavelength of the excitation light from the third light source 17c is converted. In this way, the excitation light from each light source 17 is converted into visible light of a desired wavelength and used for display.

In the light-emitting display element 100, the portion where the first light-emitting layer 13a is provided constitutes a sub-pixel that performs red display. That is, the first light-emitting layer 13a of the wavelength conversion substrate 11 converts the excitation light from the opposing first light source 17a of the light source substrate 18 into red light. In addition, the portion where the second light-emitting layer 13b is provided constitutes a sub-pixel that performs green display. That is, the second light-emitting layer 13b converts the excitation light from the opposing second light source 17b of the light source substrate 18 into green light. In addition, the portion where the third light-emitting layer 13c is provided constitutes a sub-pixel that performs blue display. For example, when ultraviolet light is used as the excitation light, the third light-emitting layer 13c converts the ultraviolet light from the opposing third light source 17c of the light source substrate 18 into blue light. 1 shows separately the first light source 17a, the second light source 17b, and the third light source 17c, which are preferably basically the same light source, especially a blue excitation light source, preferably by the first light-emitting layer 13a, An embodiment in which the second light-emitting layer 13b and the third light-emitting layer 13c are converted into each color.

Furthermore, in the light-emitting display element 100, when blue light is used as the excitation light from the third light source 17c, the wavelength conversion substrate 11 may use a light-scattering layer formed by dispersing light-scattering particles in a resin instead of the third light-scattering layer. Light emitting layer 13c. By setting in this way, it is possible to use the original wavelength characteristics of the blue light as the excitation light without performing wavelength conversion.

The light-emitting display element 100 includes three sub-pixels including sub-pixels of the first light-emitting layer 13a, sub-pixels including the second light-emitting layer 13b, and sub-pixels including the third light-emitting layer 13c to form a pixel. The pixel becomes the smallest unit that constitutes an image.

The light-emitting display element 100 having the above configuration controls the red, green, or blue color of the sub-pixels including the first light-emitting layer 13a, the sub-pixels including the second light-emitting layer 13b, and the sub-pixels including the third light-emitting layer 13c, respectively. The light shines and displays in full color.

Furthermore, in the light-emitting display device 100, a color filter may be provided between the light-emitting layer 13 and the first substrate 12. That is, a red color filter can be provided between the first light-emitting layer 13a and the first substrate 12, a green color filter can be provided between the second light-emitting layer 13b and the first substrate 12, and a green color filter can be provided between the second light-emitting layer 13b and the first substrate 12. A blue color filter is provided between the light-emitting layer 13c and the first base material 12. Thereby, the purity of the display color can be improved. Here, as a color filter, a well-known color filter for display elements etc. can be formed and used by a well-known method.

＜Method of forming wavelength conversion film＞ The method of forming a wavelength conversion film according to an embodiment of the present invention includes a step of directly or indirectly forming a coating film on a substrate (coating film forming step), and a step of heating the coating film (heating step), and The coating film is formed from this cured film forming composition. When the composition for forming a cured film contains (G) a radiation-sensitive compound, etc., the forming method may further include irradiating (exposing) at least a part of the coating film between the coating film forming step and the heating step. ) The step of radiation (radiation irradiation step), and the step of developing the coating film after radiation irradiation (development step). Hereinafter, each step will be described separately.

(Coating film formation step) In the coating film forming step, for example, the cured film forming composition is directly or indirectly applied to the substrate to form a coating film. After coating this cured film forming composition, the coating surface may be heated (pre-baked) to remove the solvent and the like.

The material of the substrate on which the coating film is formed is not particularly limited, and examples thereof include glass, quartz, silicon, and resin. Specific examples of the resin include, for example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyether sulfide, polycarbonate, polyimide, cyclic Addition polymers of cyclic olefins, ring-opening polymers of cyclic olefins, and hydrogenated products thereof. In addition, for these substrates, pre-treatments such as chemical treatment using a silane coupling agent, plasma treatment, ion plating, sputtering, and vacuum evaporation may be performed as needed.

The coating method of the composition for forming a cured film is not particularly limited. For example, spray method, roll coating method, spin coating method (spin coating method), slot die coating method, bar coating method, etc. can be used. . Among these coating methods, the spin coating method and the slot die coating method are preferred. The conditions of heating (pre-baking) also differ depending on the types of ingredients, the mixing ratio, etc., for example, as long as it is set at a temperature of 70°C or more and 130°C or less, preferably 100°C or less, heating for 1 minute or more and 10 minutes The following time is fine.

(Radiation irradiation step) In the radiation irradiation step, at least a part of the coating film formed on the substrate is irradiated with radiation. When only a part of the coating film is irradiated with radiation, for example, the radiation may be irradiated through a photomask having a pattern of a desired shape. By using this photomask, part of the irradiated radiation passes through the photomask, and this part of the radiation is irradiated to the coating film.

The radiation used in the irradiation includes visible rays, ultraviolet rays, extreme ultraviolet rays, electron beams, X-rays, and the like. Among these radiations, radiation having a wavelength in the range of 190 nm or more and 450 nm or less is preferable, and radiation including ultraviolet rays of 365 nm is more preferable.

The lower limit of the cumulative irradiation amount (exposure amount) in the radiation irradiation step is preferably 100 J/m ² , and more preferably 200 J/m ² . In addition, the upper limit of the cumulative irradiation amount is preferably 2,000 J/m ² , and more preferably 1,000 J/m ² . Furthermore, in this manual, the so-called "cumulative exposure" refers to the use of an illuminance meter (such as OAI Optical Associates Inc.'s "OAI model (OAI model) 356") to the radiation wavelength of 365 nm The following intensity is the cumulative value of the value obtained by the measurement.

(Development step) In the development step, the coating film irradiated with radiation is developed to remove unnecessary parts. The developer used in the development can be used, for example: sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, tetramethylammonium hydroxide, tetraethylammonium hydroxide, etc. An aqueous solution of at least one compound. To the aqueous solution of the basic compound, an appropriate amount of water-soluble organic solvents such as methanol and ethanol may also be added and used.

Examples of the development method include a liquid coating method, a dipping method, a shaking dipping method, and a spray method. The development time varies depending on the composition of the cured film forming composition, and the lower limit of the development time is preferably 5 seconds, more preferably 10 seconds. In addition, the upper limit of the development time is preferably 300 seconds, more preferably 180 seconds. After the development process, for example, running water cleaning is performed for a period of 30 seconds or more and 90 seconds or less, and then dried with compressed air or compressed nitrogen, thereby obtaining a desired pattern.

(Heating step) In the heating step, the coating film is heated (post-baking) by an appropriate heating device such as a hot plate and an oven. Thereby, a sufficiently hardened wavelength conversion film can be obtained on the substrate.

The lower limit of the heating temperature in this step is preferably 100°C, more preferably 140°C. By setting the heating temperature to be equal to or higher than the above lower limit, more sufficient curing can be performed. In addition, the upper limit of the heating temperature is preferably 250°C, more preferably 220°C. By setting the heating temperature to be equal to or lower than the upper limit, deterioration of semiconductor nanoparticles and the like can be suppressed, and the fluorescence quantum yield of the obtained wavelength conversion film can be further improved. In the case of heating using a hot plate, the lower limit of the heating time is preferably 5 minutes, and the upper limit is preferably 30 minutes. In addition, in the case of heating in an oven, the lower limit of the heating time is preferably 10 minutes, and the upper limit is preferably 180 minutes.

When the method is applied to the light-emitting layer of the light-emitting display element 100, it is only necessary to use three kinds of cured film forming compositions, repeat the light-emitting layer forming method including the steps, and form the first The light-emitting layer 13a, the second light-emitting layer 13b, and the third light-emitting layer 13c may be used. In addition, although a specific example is not shown in an Example, the cured film formation composition of this invention can also be used as a composition for inkjet. [Example]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)] Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. Installation: "GPC-101" of Showa Denko Corporation Pillar: Connected with "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804" of Showa Denko Corporation Mobile phase: Tetrahydrofuran Column temperature: 40℃ Flow rate: 1.0 mL/min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Detector: Differential refractometer Standard material: monodisperse polystyrene

[Synthesis example 1] Synthesis of semiconductor nanoparticle (A-1) ( _{preparation of In(OLA) 3} solution (solution A)) Prepare to install connecting pipes and thermocouple thermometers to the vacuum line and nitrogen line at three ports And the septum and put into a three-necked flask with a stirrer. In the three-necked flask, _{0.57 g of indium acetate (In(OAc) 3} ), 1.66 g of oleic acid (OLA), and 7.52 g of octadecene (ODE) were mixed. After that, the mixture was heated to 260°C under reduced pressure, and maintained at 260°C for 1 hour to remove by-produced acetic acid, water, and oxygen. Thus, solution A was obtained.

(Preparation of P(SiMe ₃ ) ₃ · octadecene solution (solution B)) In a glove box, _{mix 0.25 g of tris(trimethylsilyl)phosphine (P(SiMe 3} ) ₃ ) and 0.98 g of ODE. The obtained solution B was enclosed in a pressure-resistant vial.

(Synthesis of InP core) The prepared solution A was heated to 300° C., and a separately prepared and degassed 20% by mass ODE solution of zinc myristate was added. After that, the prepared solution B was quickly sent to the flask containing the solution A by using a cannular tube (cannular). After the pressure feeding, the temperature of the reaction solution dropped to 265°C, so the reaction temperature was set to 270°C and the reaction was carried out for 2 hours. After that, the reaction liquid was cooled to room temperature. Furthermore, solution A was used so that In(OLA) ₃ , P(SiMe ₃ ) ₃ , and zinc myristate as a ligand during nucleosynthesis became 2 mmol, 1 mmol, and 3 mmol, respectively. , Solution B and zinc myristate.

(Preparation of nuclear dispersion) Move the flask containing the reaction solution to the glove box, and move the internal solution to the beaker. After adding 8 g of toluene into the beaker containing the reaction liquid, 100 g of n-butanol was added to allow the particles to settle. After that, the particles were separated by sedimentation after centrifugal separation. The supernatant solvent was removed from the self-settling particles, and the particles were dispersed in 20 g of toluene again. Repeat the same operation 5 times. After that, 100 g of n-butanol was added to the redispersion solution, the particles were settled again, and the particles were dried by vacuum drying (50° C., 1.0 Torr, 1 hour). 10 g of hexane was added to the dry particles and redispersed to obtain a hexane dispersion of InP cores.

(Synthesis of ZnS shell) A core dispersion liquid containing 100 mg of InP cores was taken out from the obtained core dispersion liquid. After mixing the taken-out core dispersion with a Zn(OLA) ₂ 3.75 mmol/ODE 5 g solution, it was heated under vacuum at 60° C. for 1 hour to fully remove the hexane. Furthermore, the ZnS shell is formed by the reaction of Zn(OLA) _{2 and dodecyl mercaptan.} Use nitrogen in the flask to return to a nitrogen environment. Thereafter, the solution was heated to 200° C. and maintained at the same temperature for 30 minutes to obtain semiconductor nanoparticle (A-1) containing core-shell type nanocrystals in which a Zns shell was coated with an InP core.

[Synthesis Example 2] Synthesis of Semiconductor Nanoparticles (A-2) (Addition of Ligand) The reaction solution was heated to 210°C, and a solution of 3.75 mmol/ODE 5 g of dodecyl mercaptan was added in 30 minutes, and then maintained at the same temperature for 1.5 hours. Furthermore, after adding the Zn(OLA) ₃ /ODE solution, dodecyl mercaptan is added to the mixed solution using a syringe pump for an appropriate time, thereby synthesizing semiconductor nanoparticles (A-2). Furthermore, the last added dodecyl mercaptan is attached to the outer surface of the ZnS shell as a ligand (second ligand). That is, the obtained semiconductor nanoparticle (A-2) has a core-shell type nanocrystal with a ZnS shell coated on an InP core, and dodecyl mercaptan attached to the nanocrystal as a ligand. .

After adding 10 g of toluene to the beaker containing the reaction solution containing the synthesized semiconductor nanoparticle (A-2), 150 g of n-butanol was added, the particles were allowed to settle, and the particles were separated by centrifugal separation. The supernatant solvent was removed from the self-settling particles, and the particles were dispersed in 20 g of toluene again. After that, 1100 g of n-butanol was added to the dispersion, the particles were allowed to settle, and the particles were separated by centrifugal separation. After performing the same operation 5 times, the particles were dried by vacuum drying (50°C, 133 Pa, 1 hour).

(Measurement of average particle size) The average particle diameter of the obtained semiconductor nanoparticle (A-2) was measured using a transmission electron microscope ("JEM-2010F" of JEOL Ltd.). Specifically, the long diameter and short diameter of 20 arbitrarily selected particles are respectively measured, the diameter ((long diameter + short diameter)/2) of each particle is obtained, and the average value is calculated. The average particle size of semiconductor nanoparticles (A-2) is 4.8 nm.

(Determination of the shell covering condition) Through the elemental mapping of Energy dispersive X-ray spectrometer (EDS) using the TEM measurement of the semiconductor nanoparticle (A-2), it was confirmed that every 100 core-shell nanoparticle The rice crystal contains only less than one particle of ZnS. This confirmed that substantially all Zn and S were coated with core-shell nanocrystals containing In and P.

[Synthesis Example 3] Synthesis of Semiconductor Nanoparticles (A-3) (Land Exchange) A toluene dispersion containing 100 mg of the semiconductor nanoparticles (A-2) obtained in Synthesis Example 2 was prepared. The polyethylene glycol methyl ether thiol represented by the following formula as a ligand was added to this dispersion liquid, and it heated at 70 degreeC for 1 hour. After that, washing and drying were repeated to obtain a dispersion liquid of semiconductor nanoparticle (A-3). The semiconductor nanoparticle (A-3) is obtained by exchanging part of the dodecyl mercaptan as the ligand of the semiconductor nanoparticle (A-2) for polyethylene glycol methyl ether mercaptan. The content of the first ligand and the second ligand of the semiconductor nanoparticle (A-3) was measured using a nuclear magnetic resonance device (using AVANCEIII HD manufactured by BRUKER), and the solid content concentration of the sample _{in CDCl 3} The semiconductor nanoparticle is dissolved at 2% by mass and ^{measured by a standard sequence measured by 1} H nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR). The result is relative to the total content of the first ligand and the second ligand The content of the first ligand is 40% by mass.

所述式中，n為約20。[化7]

In the formula, n is about 20.

[Synthesis Example 4] Synthesis of Semiconductor Nanoparticles (A-4) In the ligand exchange described in Synthesis Example 3, the steps of adding polyethylene glycol methyl ether thiol and heating at 70°C for 1 hour were repeated twice, and 12 g of n-butanol was added and the particles were allowed to settle. The steps for separating particles by centrifugal separation were performed, except for that, the same operation as in Synthesis Example 3 was performed. Thereby, a semiconductor nanoparticle (A-4) in which the content of the first ligand relative to the total amount of the first ligand and the second ligand is 60% by mass can be obtained.

[Synthesis Example 5] Synthesis of polymer (D-1) Into a flask including a stirrer, 200 parts by mass of propylene glycol monomethyl ether acetate, 70 parts by mass of cyclohexyl methacrylate, 20 parts by mass of succinic acid mono(2-methacryloxyethyl) ester, 10 parts by mass of acrylic acid, 3.0 parts by mass of 2,2'-azobisisobutyronitrile, and 7.0 parts by mass of pentaerythritol tetrakis (3-mercaptopropionate) were replaced with nitrogen. The mixed solution was maintained at 80°C and polymerized for 4 hours. Thereafter, the temperature of the reaction solution was raised to 100°C, and after further polymerization for 1 hour, it was cooled to room temperature. Thereby, the propylene glycol monomethyl ether acetate solution of the copolymer (D-1) of cyclohexyl methacrylate, succinic acid mono(2-methacryloyl acrylate), and methacrylic acid was obtained. The Mw of the obtained polymer (D-1) was 13,500, and the Mn was 7,100. In addition, in Synthesis Example 5 to Synthesis Example 8, the content ratio of each structural unit in the obtained polymer can be regarded as the same as the ratio of the input amount of the corresponding monomer.

[Synthesis Example 6] Synthesis of polymer (D-2) Except that 20 parts by mass of succinic acid mono(2-methacryloxyethyl) succinate of Synthesis Example 5 was set to 20 parts by mass of 2-ethylhexyl methacrylate, the same procedure as Synthesis Example 5 was carried out. A propylene glycol monomethyl ether acetate solution of polymer (D-2) was obtained. The Mw of the obtained polymer (D-2) was 13,300, and the Mn was 7,000.

[Synthesis Example 7] Synthesis of polymer (D-3) The input amount of cyclohexyl methacrylate of Synthesis Example 5 was 50 parts by mass, and 20 parts by mass of 2-ethylhexyl methacrylate were further added, and the polymer was obtained in the same manner as in Synthesis Example 5 ( D-3) Propylene glycol monomethyl ether acetate solution. The Mw of the obtained polymer (D-3) was 13,700, and the Mn was 7,100.

[Synthesis Example 8] Synthesis of polymer (D-4) The input amount of cyclohexyl methacrylate of Synthesis Example 5 was set to 94 parts by mass, mono(2-methacryloxyethyl) succinate was set to 4 parts by mass, and methacrylic acid was set to Except for 2 parts by mass, in the same manner as in Synthesis Example 5, a propylene glycol monomethyl ether acetate solution of polymer (D-4) was obtained. The Mw of the obtained polymer (D-4) was 13,600, and the Mn was 7,100.

The components used in the examples and comparative examples are shown below. (A) Semiconductor Nanoparticles ·A-2: The semiconductor nanoparticle obtained in Synthesis Example 2 (A-2) ·A-3: The semiconductor nanoparticle obtained in Synthesis Example 3 (A-3) ·A-4: The semiconductor nanoparticle obtained in Synthesis Example 4 (A-4)

(B) Urethane (meth)acrylate and other (meth)acrylates ·B-1: Urethane (meth)acrylate (an amine represented by the following formula having an isocyanuric acid structure and a urethane bond, a polymerizable group number of 15, and a molecular weight of about 2300 (U-15HA, manufactured by Shinnakamura Chemical Co., Ltd.)

[化8]

·B-2: Urethane (meth)acrylate (an amine with a urethane bond, no isocyanuric acid structure or triazine structure, a polymerizable group of 10, and a molecular weight of about 4900 ("UN-904" made by Negami Kogyo Co., Ltd.)

·B-3: Urethane (meth)acrylate (a urethane acrylate with a urethane structure, a polymerizable group of 9, and a molecular weight of about 1400, manufactured by Shinnakamura Chemical Co., Ltd. "UA-33H")

·B-4: Urethane (meth)acrylate (urethane acrylate represented by the following formula having a urethane structure, a polymerizable group number of 6, and a molecular weight of about 760 "U-6LPA" manufactured by Shinnakamura Chemical Co.)

[化9]

B-5: Urethane (meth)acrylate (urethane formic acid represented by the following formula having a triazine structure and a urethane bond, the number of polymerizable groups is 6, and the molecular weight is about 1019 Ester acrylate) [Chemical 10]

·B-1: Dipentaerythritol hexaacrylate

(C) Light diffusion particles ·C-1: Titanium oxide particles coated with alumina (average particle size 150 nm, "A-190" of Sakai Chemical Co., Ltd.) ·C-2: Cerium oxide particles (average particle size 60 nm "ZENUS HC60" of Solvay)

(D) Polymer · D-1: The polymer obtained in Synthesis Example 5 (D-1) ·D-2: The polymer obtained in Synthesis Example 6 (D-2) ·D-3: The polymer obtained in Synthesis Example 7 (D-3) ·D-4: The polymer obtained in Synthesis Example 8 (D-4)

(E) Antioxidant ·E-1: Phenolic antioxidant (3,9-bis[2-[3-(tertiary butyl-4-hydroxy-5-methylphenyl)propanyloxy]-1,1-di Methylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane (Sumilizer GA-80 of Sumitomo Chemical)

(F) Dispersion medium ·F-1: Propylene glycol monomethyl ether acetate ·F-2: Toluene

(G) Radiation-sensitive compounds ·G-1: 2,2-Dimethoxy-1,2-diphenylethane-1-one ("Omnirad 651" from IGM Resins BV (IGM Resins BV)) With 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (IGM Resins BV) company’s "Omnirad (Omnirad) )907”) a mixture with a mass ratio of 1:1 ·G-2: 2,4,6-trimethylbenzyl diphenyl phosphine oxide (“LUCIRIN LR8953X” from IGM Resins BV) and O-A-oxime compound ("NCI-930" of ADEKA company) a mixture with a mass ratio of 1:1 ·G-3: Bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide ("Omnirad 819" from IGM Resins BV) and Ethyl ketone, 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime) (BASF) The company's "Irgacure OXE02") is a mixture with a mass ratio of 1:1

[Example 1] To 100 parts by mass of the dispersion medium (F-1), add 10 parts by mass of semiconductor nanoparticle (A-4), 30 parts by mass of urethane (meth)acrylate (B-1), and light diffusion particles (C-1) 10 parts by mass, 5 parts by mass of antioxidant (E-1), and 5 parts by mass of radiation-sensitive compound (G-1) to prepare the cured film forming composition of Example 1.

[Example 2 to Example 16, and Comparative Example 1, and Comparative Example 2] Except that the type and the amount of each blended component were as described in Table 1 below, each cured film forming composition was prepared in the same manner as in Example 1.

The obtained compositions for forming a cured film were evaluated in accordance with the following methods.

[Fluorescence Quantum Yield] Regarding the fluorescence quantum yield, for the wavelength conversion film obtained by the following formation method, an absolute PL fluorescence quantum yield measuring device (“C11347-01” of Hamamatsu Photonics Co., Ltd.) was used at 25°C. Determination. Set the wavelength of the excitation light to 450 nm. In addition, the wavelength conversion film obtained by the following formation method was separately heated (post-baked) at 180° C. for 20 minutes in a clean oven, and then the fluorescence quantum yield was measured by the same method as described above. The fluorescence quantum yield of the former (untreated) and the fluorescence quantum yield of the latter (after heat treatment) were evaluated according to the following criteria. ·Fluorescence quantum yield (untreated) AA: more than 60% A: 55% or more and less than 60% B: 50% or more and less than 55% C: less than 50% ·Fluorescence quantum yield (after heat treatment) AA: 55% or more A: More than 50% and less than 55% B: 40% or more and less than 50% C: less than 40% In the case of AA, A and B, it is judged that the fluorescence quantum yield is high and the fluorescence performance is good. The evaluation results are shown in Table 1.

(Method of forming wavelength conversion film) After coating each composition for forming a cured film on an alkali-free glass substrate with a spinner, it is pre-baked on a hot plate at 90°C for 2 minutes to form a coating film . Next, the obtained coating film is irradiated with radiation of each wavelength including 365 nm, 405 nm, and 436 nm at a cumulative irradiation dose of ^{700 J/m 2} using a high-pressure mercury lamp without intervening a light shield, thereby forming an average thickness of 5 μm wavelength conversion film.

[Half width] For the wavelength conversion film (after heat treatment) obtained by the method, the absolute PL fluorescence quantum yield measuring device (“C11347-01” of Hamamatsu Photonics) was used to measure the fluorescence half at 25°C. Value width. Set the wavelength of the excitation light to 450 nm. The smaller the value of the half-value width, the better the wavelength conversion into fluorescence with high color purity even after the heat treatment. The half-value width was evaluated according to the following criteria. AA: less than 45 nm A: 45 nm or more and less than 50 nm B: 50 nm or more and less than 55 nm C: 55 nm or more In the case of AA, A, and B, it is judged that the half-value width is sufficiently narrow and the fluorescence performance is good. The evaluation results are shown in Table 1.

[Coatability] The wavelength conversion film (heat-treated) was measured using a stylus-type step meter (trade name "Alpha-Step IQ surface profiler ASIQ", manufactured by KLA-tencor) The arithmetic mean surface roughness (Ra) of the surface after) was evaluated according to the following criteria. A: Ra is less than 500 angstroms (angstrom) B: Ra is more than 500 angstroms and less than 1000 angstroms C: Ra is more than 1000 Angstroms In the case of A and B, it was judged that the coatability was good. The evaluation results are shown in Table 1.

[Dispersion stability] After preparing each cured film formation composition, it was stirred for 10 minutes with a stirrer, the sedimentation after 2 hours was confirmed, and the evaluation was performed in accordance with the following criteria. AA: No settlement is seen A: Almost no settlement B: see some settlement C: see a lot of settlement In the case of AA, A, and B, it was judged that the dispersion stability was good. The evaluation results are shown in Table 1.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 4-2 Example 5 Example 6 Example 7 Example 7-2 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Comparative example 1 Comparative example 2 (A) Semiconductor nanoparticles (parts by mass) A-2 10 A-3 10 A-4 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 (B) Urethane (meth)acrylate (parts by mass) B-1 30 30 30 30 30 30 30 30 30 30 30 40 20 B-2 30 B-3 30 B-4 30 B-5 30 - b-1 30 30 (C) Light diffusion particles (parts by mass) C-1 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 C-2 20 (D) Polymer (parts by mass) D-1 30 D-2 30 D-3 30 30 30 30 30 30 30 30 30 30 30 30 30 30 D-4 30 (E) Antioxidant (parts by mass) E-1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 (F) Dispersion medium (parts by mass) F-1 100 100 100 100 100 100 100 100 100 100 100 100 50 100 100 100 100 100 100 100 F-2 50 (G) Radiation-sensitive compound (parts by mass) G-1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 G-2 5 G-3 5 Fluorescence quantum yield Untreated A A A AA A AA AA A AA A A AA AA B AA A A A B A After heat treatment B A A AA A AA AA A AA A B A A B AA A A A C B Half-value width A A A AA B AA AA A AA B B AA AA B AA A AA AA B B Coatability B B B A B B A B A B B B B B B A A A C C Dispersion stability B A B AA B AA A A AA B B AA AA B AA AA AA AA B A

As shown in Table 1, it is known that the cured film-forming composition of Examples 1 to 16 using urethane (meth)acrylate as the polymerizable compound has the fluorescence of the wavelength conversion film obtained. Good light performance (fluorescent quantum yield and half-value width), dispersion stability and coating properties are also good. On the other hand, regarding the cured film-forming composition of Comparative Example 1 and Comparative Example 2 which does not contain urethane (meth)acrylate, the fluorescent performance, dispersion stability, and coating of the obtained wavelength conversion film The distributivity is not a good result. [Industrial availability]

The composition for forming a cured film of the present invention can be preferably used as a material for forming wavelength conversion films and the like of light-emitting display elements.

11: Wavelength conversion substrate 12: The first substrate 13: Light-emitting layer (wavelength conversion film) 13a: The first light-emitting layer 13b: The second light-emitting layer 13c: third light-emitting layer 14: black matrix 15: Adhesive layer 16: The second substrate 17: light source 17a: first light source 17b: 2nd light source 17c: third light source 18: Light source substrate 100: Light-emitting display element

Fig. 1 is a cross-sectional view schematically showing a light-emitting display element according to an embodiment of the present invention.

11: Wavelength conversion substrate

12: The first substrate

13: Emitting layer (wavelength conversion film)

13a: The first light-emitting layer

13b: The second light-emitting layer

13c: third light-emitting layer

14: black matrix

15: Adhesive layer

16: The second substrate

17: light source

17a: first light source

17b: 2nd light source

17c: third light source

18: Light source substrate

100: Light-emitting display element

Claims (18)

A composition for forming a cured film, containing: (A) Semiconductor nanoparticles; and (B) Urethane (meth)acrylate has a plurality of polymerizable groups. The composition for forming a cured film according to claim 1, wherein the (B) urethane (meth)acrylate has 4 or more and 30 (meth)acrylate groups. The composition for forming a cured film according to claim 1 or 2, wherein the (A) semiconductor nanoparticle has a ligand, The ligand has a carboxyl group, a thiol group, a phosphine group, an amide group or a combination of these. The composition for forming a cured film according to claim 1 or 2, wherein the (B) urethane (meth)acrylate has an isocyanuric acid structure, a triazine structure, or a combination of these . The composition for forming a cured film according to claim 1 or 2, wherein the (B) urethane (meth)acrylate has a molecular weight of 600 or more and 6,000 or less. The composition for forming a cured film according to claim 1 or 2, wherein the (B) urethane (meth)acrylate is represented by the following formula (1),

(In formula (1), R ¹ is an m-valent organic group having 1 to 60 carbon atoms; each of R ^{2 is} independently a group containing one or more (meth)acryloyl groups; m is 2 or 3) . The composition for forming a cured film according to claim 6, wherein R ^{2 in} the formula (1) is represented by the following formula (2),

(In formula (2), R ³ is a single bond or an alkanediyl group having 1 to 3 carbons; R ⁴ is a (meth)acryloyl group; n is 1 or 2; p is 0 or 1; q is 1 to 3). The composition for forming a cured film according to claim 6, wherein R ¹ in the formula (1) is represented by the following formula (3-1) or (3-2), and m is 3,

(In the formula (3-1) and the formula (3-2), a plurality of R ^{5 is} each independently a single bond or an alkanediyl group having 1 to 12 carbon atoms). The composition for forming a cured film according to Claim 1 or Claim 2, which further contains (C) light diffusing particles. The composition for forming a cured film as described in Claim 1 or Claim 2, which further contains (D) a polymer. The composition for forming a cured film according to claim 10, wherein the (D) polymer has an acidic group. The composition for forming a cured film according to claim 10, wherein the (D) polymer contains 5% by mass or more of a structural unit having an acidic group. The composition for forming a cured film according to claim 11, wherein the (D) polymer has a side chain having 5 to 15 carbon atoms including the acidic group. The composition for forming a cured film according to claim 10, wherein the (D) polymer has a chain hydrocarbon group having 4 to 20 carbon atoms. The composition for forming a cured film according to claim 10, wherein the (D) polymer includes both a structural unit having an acidic group and a structural unit having a chain hydrocarbon group having 4 to 20 carbon atoms. A wavelength conversion film formed of the composition for forming a cured film according to any one of claims 1 to 15. A light-emitting display element includes the wavelength conversion film according to claim 16. A method for forming a wavelength conversion film includes: The step of directly or indirectly forming a coating film on the substrate, and The step of heating the coating film, and The coating film is formed from the composition for forming a cured film according to any one of claims 1 to 15.

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