WO2022244668A1

WO2022244668A1 - Ink composition, light conversion layer, color filter, and light conversion film

Info

Publication number: WO2022244668A1
Application number: PCT/JP2022/020035
Authority: WO
Inventors: 方大小林; 栄志乙木; 麻里子利光; 浩一延藤; 祐貴野中
Original assignee: Dic株式会社
Priority date: 2021-05-21
Filing date: 2022-05-12
Publication date: 2022-11-24
Also published as: JPWO2022244668A1; CN117178035A; KR20240011666A; JP7367894B2

Abstract

Provided is an ink composition that has exceptional dispersibility of luminescent nanocrystal particles and that is capable of preventing any reduction of luminescence. This ink composition is characterized by containing luminescent nanocrystal particles, a photopolymerizable component, and a hindered amine compound, and also is characterized in that the photopolymerizable component includes at least one photopolymerizable compound having a δD of 16-17.5 MPa0.5, a δP of 2.5-5 MPa0.5, and a δH of 3-6 MPa0.5 in the Hansen solubility parameters (HSP). The photopolymerizable compound is preferably a monofunctional or polyfunctional (meth)acrylate.

Description

Ink composition, light conversion layer, color filter and light conversion film

The present invention relates to an ink composition, a light conversion layer, a color filter and a light conversion film.

Liquid crystal display devices are widely used for applications such as mobile terminals, televisions, and monitors. Color filters used in these liquid crystal display devices are manufactured by a photolithographic method that forms a black matrix and red, green and blue pixel patterns. Specifically, in the photolithography method, a photosensitive resin composition containing coloring materials such as pigments and dyes is coated on a substrate, dried, mask-exposed with UV irradiation, and uncured portions are removed by alkali development. Firing is then performed. Further, in recent years, self-luminous display devices in which an organic EL element that emits white light and a color filter are combined are also widely used for applications such as televisions and monitors.

However, in display devices using these color filters, in principle, at least 67% of the light is absorbed by the color filters, so there is a fundamental limit to reducing power consumption by improving the transmittance of the color filters themselves. there were.

In order to solve the problem of low power consumption, in recent years, instead of the above pigments and dyes, for example, luminescent nanoparticles such as quantum dots, quantum rods, and other inorganic phosphor particles have been used to emit red or green light. Active research is being conducted on light conversion layers such as light conversion films to be taken out and color filter pixel portions.

This light conversion layer is mounted on the backlight unit of the image display device. For example, when a light conversion film containing quantum dots that emit red light and quantum dots that emit green light is irradiated with blue light as excitation light, the red light and green light emitted from the quantum dots and the light conversion film White light can be obtained with the blue light that has passed through.

Further, the light conversion layer includes, for example, a red-emitting quantum dot layer that emits red fluorescence when excited by blue light and a green quantum dot layer that emits green fluorescence when excited by blue light on a substrate on which a black matrix is formed. It is formed by forming a luminescent quantum dot layer and a blue light transmission layer that transmits blue light. A liquid crystal display device or a self-luminous display device is configured by combining such a light conversion layer with an LED backlight that emits blue light or an organic EL element that emits blue light.

A display device with such a light conversion layer can increase light utilization efficiency more than a display device with a conventional color filter. In addition, since fluorescence emitted from the quantum dots and having a spectrum with a small half-value width can be used as it is for color display of the display device, the display device can have a wide color reproduction range.

For example, a method is known in which a photosensitive resin composition containing quantum dots is applied to one entire surface of a substrate and cured by ultraviolet irradiation to produce a light conversion film.

Alternatively, for example, the light conversion layer is formed by forming a coating film on one side of the substrate using a photosensitive resin composition containing quantum dots, patterning the coating film by photolithography, and then heating the resulting coating film. A method of hardening by treatment is known (see, for example, Patent Document 1).
However, according to the photolithography method, the number of steps is large and complicated, and since the photosensitive resin composition is removed by alkali development, raw materials are inevitably wasted.

A manufacturing method using an inkjet method is known as a method capable of reducing waste of raw materials. According to the inkjet method, the red light-emitting quantum dot layer and the green light-emitting quantum dot layer in the light conversion layer can be formed at the same time, so that the manufacturing efficiency can be improved. In addition, since all of the ejected ink (photosensitive resin composition) can be used, waste of raw materials such as in photolithography is less likely to occur.
For example, as an inkjet ink in which quantum dots are dispersed, an example of use for patterning a light conversion layer used in combination with an organic EL element emitting blue light is disclosed (see, for example, Patent Document 2).

JP 2016-53716 A WO2008/001693

However, there is a problem that ink compositions containing quantum dots and their film products deteriorate due to oxygen and moisture contained in the atmosphere. According to the studies of the present inventors, in particular, when a photopolymerizable component is mixed with an ink composition containing quantum dots and cured with ultraviolet rays, or in a process after forming a film containing quantum dots, It was found that quantum dots tend to deteriorate when exposed to ultraviolet light or visible light in the presence of atmospheric oxygen or moisture.

These problems can be avoided by isolating the quantum dots from oxygen and moisture. Completely isolating the printed matter from the atmosphere has a big demerit in terms of industrial application. That is, most of the coating device and the printing device have to be placed in a space filled with a high-purity inert gas, which requires a huge capital investment and a high running cost.

Therefore, one of the objects of the present invention is to use a hindered amine compound and a photopolymerizable compound having predetermined properties in combination to achieve excellent dispersibility of luminescent nanocrystalline particles and prevent deterioration of luminescent properties. It is an object of the present invention to provide an ink composition capable of Further objects of the present invention are to provide a light conversion layer containing a cured product of the ink composition and a color filter having the same, and to provide a light conversion film containing the cured product of the ink composition. .

The present invention relates to the following (1) to (13).
(1) The ink composition of the present invention comprises luminescent nanocrystalline particles,
a photopolymerizable component;
containing a hindered amine compound,
The photopolymerizable component has at least one Hansen Solubility Parameter (HSP) δD of 16 to 17.5 MPa ^0.5 , δP of 2.5 to 5 MPa ^0.5 and δH of 3 to 6 MPa ^0.5 It is characterized by containing a photopolymerizable compound of the type.

(2) In the ink composition of the invention, the photopolymerizable compound is preferably a monofunctional or polyfunctional (meth)acrylate.
(3) In the ink composition of the invention, the photopolymerizable compound is preferably a bifunctional (meth)acrylate represented by the following formula (1).

[In formula (1), R ¹ represents an alkylene group having 4 to 8 carbon atoms, and two R ² independently represent a hydrogen atom or a methyl group. ]

(4) In the ink composition of the present invention, the proportion of the photopolymerizable compound in the photopolymerizable component is preferably 30% by mass or more.
(5) In the ink composition of the present invention, the hindered amine compound preferably has a partial structure represented by the following formula (2).

[In Formula (2), R ³ represents a hydrogen atom or a substituent, R ⁴ represents a linking group, and * represents a bond. ]

(6) In the ink composition of the present invention, R ³ in formula (2) is preferably an alkoxy group.
(7) The ink composition of the invention preferably further contains an antioxidant.
(8) The ink composition of the present invention is preferably used in a droplet ejection method using an inkjet system.

(9) The light conversion layer of the present invention includes a plurality of pixel portions and a light shielding portion provided between the adjacent pixel portions,
The plurality of pixel portions have a luminescent pixel portion containing a cured product of the ink composition.

(10) In the light conversion layer of the present invention, the plurality of luminescent pixel portions are
A first luminescent pixel containing, as the luminescent nanocrystalline particles, first luminescent nanocrystalline particles that absorb light in a wavelength range of 420 to 480 nm and emit light having an emission peak in a wavelength range of 605 to 665 nm. Department and
A second luminescent pixel containing, as the luminescent nanocrystalline particles, second luminescent nanocrystalline particles that absorb light in a wavelength range of 420 to 480 nm and emit light having an emission peak in a wavelength range of 500 to 560 nm. It is preferable to include the part.

(11) In the light conversion layer of the present invention, it is preferable that the plurality of pixel portions further have non-luminous pixel portions containing light-scattering particles.
(12) A color filter of the present invention is characterized by comprising the light conversion layer described above.
(13) The light conversion film of the present invention is characterized by containing a cured product of the above ink composition.

ADVANTAGE OF THE INVENTION According to this invention, the ink composition which is excellent in the dispersibility of a luminescent nanocrystal particle, and can prevent the deterioration of a light emission characteristic, the light conversion layer which is excellent in a light emission characteristic, a color filter, and a light conversion film can be provided. .

FIG. 1 is a schematic cross-sectional view showing one embodiment of a color filter according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing one embodiment of the light conversion film of one embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. In this specification, a numerical range indicated using "-" indicates a range including the numerical values before and after "-" as the minimum and maximum values, respectively.
Further, in this specification, the term “cured product of the ink composition” refers to a product obtained by curing the curable component in the ink composition (the ink composition after drying when the ink composition contains a solvent component). This is the resulting cured product. It should be noted that the cured product of the dried ink composition may not contain a solvent component.

<Ink composition>
The ink composition of the present invention contains luminescent nanocrystalline particles, a photopolymerizable component, and a hindered amine compound. The photopolymerizable component has a Hansen ^Solubility ^Parameter ( ^HSP ) of at least It contains one photopolymerizable compound.

The ink composition of the present invention is used, for example, to form the pixel portion of the light conversion layer of a color filter or the like. That is, the ink composition of the present invention is preferably used as an ink composition for forming a light conversion layer (for example, for forming a color filter pixel portion or for forming a light conversion film).
According to such an ink composition, the dispersibility of the luminescent nanocrystalline particles is excellent, and deterioration of optical properties can be prevented.
Although the reason why the above effects are obtained is not clear, the present inventors speculate as follows.

The hindered amine compound has the effect of suppressing deterioration due to oxidation of the luminescent nanocrystalline particles. In addition, by selecting a compound having HSP within the above range as the photopolymerizable compound, affinity with both the luminescent nanocrystalline particles and the hindered amine compound is enhanced, and these are uniformly distributed in the ink composition. can be done.
Therefore, the luminescent nanocrystalline particles are uniformly dispersed in the ink composition, and the uniformly dissolved hindered amine compound acts favorably on the luminescent nanocrystalline particles to prevent deterioration of the luminescent nanocrystalline particles. can do. As a result, according to the ink composition of the present invention, it is considered that the dispersibility of the luminescent nanocrystalline particles is excellent, and deterioration of the optical properties can be sufficiently prevented. Such an effect of preventing deterioration of optical properties is suitably exhibited during storage of the ink composition, during fabrication of the pixel portion, and the like.

Further, according to the ink composition of the present invention, there is a tendency to obtain a light conversion layer having excellent external quantum efficiency.
Furthermore, according to the ink composition of the present invention, since the luminescent nanocrystalline particles are uniformly dispersed, excellent ejection stability can be achieved in a droplet ejection method by an inkjet system (hereinafter referred to as an "inkjet method"). easy to obtain. That is, the ink composition of the invention can be suitably used in the inkjet method.
Furthermore, according to the ink composition of the present invention, since the luminescent nanocrystalline particles are uniformly dispersed, it is easy to obtain excellent applicability in a printing method using a coating method (hereinafter referred to as a “coating method”). . That is, the ink composition of the present invention can be suitably used in coating methods.

By the way, since the pixel portion is used in an environment where it is exposed to light, it is required that the external quantum efficiency does not decrease due to light (light stability). When used, it cannot be said that a pixel portion having sufficient photostability is necessarily obtained.
On the other hand, according to the ink composition of the present invention, the existence of the hindered amine compound tends to suppress the decrease in the external quantum efficiency due to light. That is, according to the ink composition of the present invention, a light conversion layer having excellent light stability can be formed.

The ink composition of one embodiment can be applied as an ink for manufacturing color filters. In view of the fact that the pixel portion (light conversion layer) can be formed only by using the amount necessary for the above, it is preferable to prepare and use it so as to be suitable for the inkjet method rather than the photolithographic method. Also, the ink composition of one embodiment is preferably carried between barrier films and used as a wavelength conversion film.

Such an ink composition contains, in addition to luminescent nanocrystalline particles, a photopolymerizable component and a hindered amine compound, if necessary, an organic ligand (hereinafter sometimes referred to as a “ligand”), a light scattering Other ingredients such as organic particles, polymeric dispersants, organic solvents, etc. may be further included.
An ink composition according to one embodiment will be described below, taking an ink composition (inkjet ink) used in an inkjet method as an example.

[Luminescent nanocrystalline particles]
Luminescent nanocrystalline particles are nano-sized crystals that absorb excitation light and emit fluorescence or phosphorescence. The luminescent nanocrystalline particles are, for example, crystals having a maximum particle size of 100 nm or less as measured by a transmission electron microscope or scanning electron microscope.

Luminescent nanocrystalline particles can, for example, emit light (fluorescence or phosphorescence) of a wavelength different from the absorbed wavelength by absorbing light of a predetermined wavelength. The luminescent nanocrystalline particles may be red luminescent nanocrystalline particles that emit light having an emission peak in the wavelength range of 605-665 nm (red light), and light having an emission peak in the wavelength range of 500-560 nm ( green light), and blue light-emitting nanocrystalline particles that emit light having an emission peak in the wavelength range of 420-480 nm (blue light).

In this embodiment, the ink composition preferably contains at least one of these luminescent nanocrystalline particles. Further, the light absorbed by the luminescent nanocrystalline particles is, for example, light with a wavelength of 400 nm or more and less than 500 nm (especially, wavelength of 420 to 480 nm) (blue light), or light with a wavelength of 200 nm to 400 nm (ultraviolet light). can be
The wavelength of the emission peak of the luminescent nanocrystalline particles can be confirmed, for example, in the fluorescence spectrum or phosphorescence spectrum measured using a spectrofluorometer.

The red-emitting nanocrystalline particles have a wavelength of 665 nm or less, 663 nm or less, 660 nm or less, 658 nm or less, 655 nm or less, 653 nm or less, 651 nm or less, 650 nm or less, 647 nm or less, 645 nm or less, 643 nm or less, 640 nm or less, 637 nm or less, 635 nm or less. , preferably has an emission peak in the range of 632 nm or less or 630 nm or less, and has an emission peak in the wavelength range of 628 nm or more, 625 nm or more, 623 nm or more, 620 nm or more, 615 nm or more, 610 nm or more, 607 nm or more, or 605 nm or more. preferable.
In addition, these upper limit and lower limit can be combined arbitrarily. In addition, in the following similar description, the upper limit and the lower limit individually described can be arbitrarily combined.

The green-emitting nanocrystalline particles have an emission peak in the wavelength range of 560 nm or less, 557 nm or less, 555 nm or less, 550 nm or less, 547 nm or less, 545 nm or less, 543 nm or less, 540 nm or less, 537 nm or less, 535 nm or less, 532 nm or less, or 530 nm or less. It preferably has an emission peak in the wavelength range of 528 nm or more, 525 nm or more, 523 nm or more, 520 nm or more, 515 nm or more, 510 nm or more, 507 nm or more, 505 nm or more, 503 nm or more, or 500 nm or more.

The blue-emitting nanocrystalline particles have an emission peak in the wavelength range of 480 nm or less, 477 nm or less, 475 nm or less, 470 nm or less, 467 nm or less, 465 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 455 nm or less, 452 nm or less, or 450 nm or less. It preferably has an emission peak in the wavelength range of 450 nm or more, 445 nm or more, 440 nm or more, 435 nm or more, 430 nm or more, 428 nm or more, 425 nm or more, 422 nm or more, or 420 nm or more.

According to the solution of the Schrödinger wave equation of the well-type potential model, the wavelength (emission color) of the light emitted by the luminescent nanocrystalline particles depends on the size (e.g., particle diameter) of the luminescent nanocrystalline particles. It also depends on the energy gap that the nanocrystalline particles have. Therefore, the emission color can be selected (adjusted) by changing the constituent material and size of the luminescent nanocrystalline particles used.

The luminescent nanocrystalline particles may be luminescent nanocrystalline particles containing a semiconductor material (luminescent semiconductor nanocrystalline particles). Examples of such luminescent nanocrystalline particles include quantum dots and quantum rods. Among these, quantum dots are preferred as the luminescent nanocrystalline particles from the viewpoint that the emission spectrum can be easily controlled, reliability can be ensured, production costs can be reduced, and mass productivity can be improved. .

The luminescent nanocrystalline particles may consist only of a core comprising a first semiconductor material and a second semiconductor covering at least a portion of the core and different from the first semiconductor material. and a shell containing the material. In other words, the structure of the luminescent nanocrystalline particles may be a structure consisting of only a core (core structure) or a structure consisting of a core and a shell (core/shell structure).

The luminescent nanocrystalline particles also include a shell (first shell) containing a second semiconductor material, and a third semiconductor material covering at least a portion of this shell and different from the first and second semiconductor materials. It may further have a shell (second shell). In other words, the structure of the luminescent nanocrystalline particles may be a structure consisting of a core, a first shell and a second shell (core/shell/shell structure).
moreover. Each of the core and shell may be a mixed crystal containing two or more semiconductor materials (eg, CdSe+CdS, CIS+ZnS, etc.).

The luminescent nanocrystalline particles are at least one selected from the group consisting of II-VI group semiconductors, III-V group semiconductors, I-III-VI group semiconductors, IV group semiconductors and I-II-IV-VI group semiconductors. semiconductor material.

Specific semiconductor materials include, for example, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, ＣｄＺｎＳｅ、ＣｄＺｎＴｅ、ＣｄＨｇＳ、ＣｄＨｇＳｅ、ＣｄＨｇＴｅ、ＨｇＺｎＳ、ＨｇＺｎＳｅ、ＣｄＨｇＺｎＴｅ、ＣｄＺｎＳｅＳ、ＣｄＺｎＳｅＴｅ、ＣｄＺｎＳＴｅ、ＣｄＨｇＳｅＳ、ＣｄＨｇＳｅＴｅ、ＣｄＨｇＳＴｅ、ＨｇＺｎＳｅＳ、ＨｇＺｎＳｅＴｅ、ＨｇＺｎＳＴｅ；ＧａＮ、ＧａＰ、ＧａＡｓ、ＧａＳｂ、ＡｌＮ、ＡｌＰ、ＡｌＡｓ、ＡｌＳｂ、 InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; SnPbSeTe, SnPbSTe; Si, Ge, SiC, SiGe, AgInSe2, _CuGaSe2 , _CuInS2 , _CuGaS2 , _CuInSe2 , _AgInS2 , _AgInGaS , _AgGaSe2 , _AgGaS2 , C, Si and Ge.

Luminescent nanocrystalline particles are CdS, CdSe, CdTe, ZnS, ZnSe, and ZnTe from the viewpoint that the emission spectrum can be easily controlled, reliability can be ensured, production costs can be reduced, and mass productivity can be improved. , ZnO, HgS, HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS2, _AgInSe2 , _AgInTe2 , _AgInGaS , _AgGaS2 , _AgGaSe2 , _AgGaTe2 , _CuInS2 , _CuInSe2 , _CuInTe It preferably contains at least one semiconductor material selected from the group consisting of CuGaS ₂ , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge and Cu ₂ ZnSnS ₄ .

Examples of red-emitting nanocrystalline particles include nanocrystalline particles of CdSe, nanocrystalline particles with a core of CdSe and a shell of CdS, nanocrystalline particles with a core of ZnSe and a shell of CdS, mixed crystals of CdSe and ZnS. nanocrystalline particles of InP, nanocrystalline particles with a core of InP and a shell of ZnS, nanocrystalline particles with a core of InP and a shell of a mixed crystal of ZnS and ZnSe, mixed crystals of CdSe and CdS nanocrystalline particles of a mixed crystal of ZnSe and CdS, nanocrystalline particles comprising a core of InP, a first shell of ZnSe and a second shell of ZnS, a core of InP, a mixed crystal of ZnS and ZnSe Nanocrystalline particles with a first shell and a second shell of ZnS, and the like.

Examples of green-emitting nanocrystalline particles include nanocrystalline particles of CdSe, nanocrystalline particles of a mixed crystal of CdSe and ZnS, nanocrystalline particles having a core of InP and a shell of ZnS, a core of InP and ZnS and ZnSe. a core of InP, a first shell of ZnSe and a second shell of ZnS, a core of InP, a first shell of a mixed crystal of ZnS and ZnSe and ZnS Examples include nanocrystalline particles with a second shell.

Blue-emitting nanocrystalline particles include, for example, nanocrystalline particles of ZnSe, nanocrystalline particles of ZnS, nanocrystalline particles with a core of ZnS and a shell of ZnSe, nanocrystalline particles of CdS, a core of InP and a shell of ZnS. Nanocrystalline particles comprising a core of InP and a shell of a mixed crystal of ZnS and ZnSe Nanocrystalline particles comprising a core of InP, a first shell of ZnSe and a second shell of ZnS, a core of InP, ZnS and ZnSe mixed crystal first shell and ZnS second shell.

By adjusting the average particle size of the nanocrystalline particles themselves with the same chemical composition, the color to be emitted from the nanocrystalline particles can be changed to either red or green.
In addition, it is preferable to use nanocrystalline particles that themselves have the least adverse effect on the human body or the like. Therefore, when using nanocrystalline particles that do not contain cadmium, selenium, etc. as much as possible, or using nanocrystalline particles containing the above elements (cadmium, selenium, etc.), Combination with other nanocrystalline particles is preferred.

The luminescent nanocrystalline particles may be nanocrystals made of metal halide from the viewpoint of obtaining an emission peak with a narrower half-width.

A nanocrystal made of metal halide is a compound semiconductor containing _A , M and X, and is a compound represented by the general formula _: _AaMbXc .
In the formula, A represents a monovalent cation and is at least one of an organic cation and a metal cation. Organic cations include ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea and the like, and metal cations include cations such as Cs, Rb, K, Na and Li.
M represents a metal ion and is at least one metal cation. Metal cations selected from groups 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14 and 15 cations. More preferably Ag, Au, Bi, Ca, Ce, Co, Cr, Cu, Eu, Fe, Ga, Ge, Hf, In, Ir, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, Cations such as Pb, Pd, Pt, Re, Rh, Ru, Sb, Sc, Sm, Sn, Sr, Ta, Te, Ti, V, W, Zn, and Zr are included.
X is at least one anion. Examples of anions include halide ions such as chloride ions, bromide ions, iodide ions, and cyanide ions.
a is 1-7, b is 1-4, and c is 3-16.
The emission wavelength (emission color) of such nanocrystals can be controlled by adjusting the particle size and the type and abundance of anions that constitute the X site.

Specifically, the compound represented by the general _formula _AaMmXx is _AMX _, _A4MX , _AMX2 , _AMX3 , _A2MX3 _, _AM2X3 , _A2MX4 _, _A2MX ₅ _, _A3MX5 _, _A3M2X5 _, _A3MX6 _, _A4MX6 _, _AM2X6 _, _A2MX6 _, _A4M2X6 _, _A3MX8 _, _A3M2 _{_} _{_} Compounds represented by X ₉ , A ₃ M ₃ X ₉ , A ₂ M ₂ X ₁₀ and A ₇ M ₃ X ₁₆ are preferred.
wherein A is at least one of an organic cation and a metal cation. Organic cations include ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea and the like, and metal cations include cations such as Cs, Rb, K, Na and Li.
wherein M is at least one metal cation. Specifically, one metal cation (M ¹ ), two metal cations (M ¹ _α M ² _β ), three metal cations (M ¹ _α M ² _β M ³ _γ ), four metal cations cations (M ¹ _α M ² _β M ³ _γ M ⁴ _δ ) and the like. However, α, β, γ, and δ each represent a real number between 0 and 1, and α+β+γ+δ=1. Metal cations selected from groups 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14 and 15 cations. More preferably Ag, Au, Bi, Ca, Ce, Co, Cr, Cu, Eu, Fe, Ga, Ge, Hf, In, Ir, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, Cations such as Pb, Pd, Pt, Re, Rh, Ru, Sb, Sc, Sm, Sn, Sr, Ta, Te, Ti, V, W, Zn, and Zr are included.
In the formula, X is an anion containing at least one halogen. Specifically, one type of halogen anion (X ¹ ), two types of halogen anions (X ¹ _α X ² _β ), and the like are included. Examples of anions include chloride ions, bromide ions, iodide ions, cyanide ions, and the like, including at least one halide ion.

The compound composed of the metal halide represented _by the _above general formula _AaMmXx is doped with metal ions such as Bi, Mn, Ca, Eu, Sb, and Yb in order to improve light emission characteristics. may be

Among the compounds composed of metal _halides represented by the general formula _AaMmXx , the compound having a perovskite-type crystal structure is adjusted by adjusting the particle size, the type and abundance of metal cations constituting the _M site, Furthermore, it is particularly preferable for use as a semiconductor nanocrystal in that the emission wavelength (emission color) can be controlled by adjusting the type and abundance of anions that constitute the X site. Specifically, compounds represented by AMX ₃ , A ₃ MX ₅ , A ₃ MX ₆ , A ₄ MX ₆ and A ₂ MX ₆ are preferred. A, M and X in the formula are as described above. Also, the compound having the perovskite crystal structure may be doped with metal ions such as Bi, Mn, Ca, Eu, Sb, and Yb, as described above.

Among compounds exhibiting a perovskite crystal structure, A is Cs, Rb, K, Na, or Li, and M is one kind of metal cation (M ¹ ), or two kinds of It is preferably a metal cation (M ¹ _α M ² _β ) and X is chloride, bromide or iodide. However, α and β each represent a real number between 0 and 1, and α+β=1. Specifically, M may be selected from Ag, Au, Bi, Cu, Eu, Fe, Ge, K, In, Na, Mn, Pb, Pd, Sb, Si, Sn, Yb, Zn, Zr. preferable.

Nanocrystals 911 using Pb as M such as CsPbBr ₃ , CH ₃ NH ₃ PbBr ₃ , CHN ₂ H ₄ PbBr ₃ , etc., as specific compositions of nanocrystals made of metal halide and having a perovskite crystal structure, have a light intensity It is preferable because it is excellent in quantum efficiency as well as excellent in _In addition, _CsSnBr3 , _CsSnCl3 , _{CsSnBr1.5Cl1.5} _, _Cs3Sb2Br9 , ₍ _CH3NH3 ₎ _3Bi2Br9 _, ₍ _C4H9NH3 ₎ _2AgBiBr6 _, _etc. Nanocrystals using metal cations other than Pb as M are preferred due to their low toxicity and low environmental impact.

The shape of the luminescent nanocrystalline particles is not particularly limited and may be any geometric shape or any irregular shape. The shape of the luminescent nanocrystalline particles may be, for example, spherical, ellipsoidal, pyramidal, disk-like, branch-like, net-like, rod-like, and the like.
However, as the luminescent nanocrystalline particles, the uniformity and fluidity of the ink composition can be further enhanced by using particles with a less directional particle shape (e.g., spherical, regular tetrahedral particles, etc.). point is preferable.

The average particle diameter (volume average diameter) of the luminescent nanocrystalline particles is preferably 1 nm or more, and preferably 1.5 nm or more, from the viewpoints of easily obtaining light emission of a desired wavelength and excellent dispersibility and storage stability. and more preferably 2 nm or more.
In addition, the average particle size of the luminescent nanocrystalline particles is preferably 40 nm or less, more preferably 30 nm or less, and even more preferably 20 nm or less, from the viewpoint of easily obtaining light emission of a desired wavelength. .
The average particle size (primary particle size) of the luminescent nanocrystalline particles can be determined by directly observing any plurality of luminescent nanocrystalline particles using a transmission electron microscope (TEM) or a scanning electron microscope (SEM). Each particle diameter is calculated from the length and breadth ratio of the projected two-dimensional image, and the average value is obtained. The size and shape of the luminescent nanocrystalline particles are considered to depend on their chemical composition, structure, manufacturing method, manufacturing conditions, and the like.

Luminescent nanocrystalline particles preferably have organic ligands near their surfaces.
This organic ligand has the function of dispersing the luminescent nanocrystalline particles. The organic ligand includes, for example, a functional group (hereinafter simply referred to as "affinity group") for ensuring affinity with a photopolymerizable compound, an organic solvent, etc., and a functional group capable of binding to luminescent nanocrystalline particles. group (functional group for ensuring adsorptivity to the luminescent nanocrystalline particles) and can coordinately bond to the surface of the luminescent nanocrystalline particles.

Affinity groups may be substituted or unsubstituted aliphatic hydrocarbon groups. An aliphatic hydrocarbon group may be linear or branched. Moreover, the aliphatic hydrocarbon group may or may not have an unsaturated bond.
A substituted aliphatic hydrocarbon may be a group in which some carbon atoms of an aliphatic hydrocarbon group are substituted with oxygen atoms. Substituted aliphatic hydrocarbon groups may include, for example, (poly)oxyalkylene groups.
Here, the "(poly)oxyalkylene group" means at least one of an oxyalkylene group and a polyoxyalkylene group in which two or more alkylene groups are linked by an ether bond.

Functional groups that can bind to luminescent nanocrystalline particles include, for example, hydroxyl groups, amino groups, carboxyl groups, thiol groups, phosphoric acid groups, phosphonic acid groups, phosphine groups, phosphine oxide groups and alkoxysilyl groups.

Examples of organic ligands include TOP (trioctylphosphine), TOPO (trioctylphosphine oxide), oleic acid, linoleic acid, linolenic acid, ricinoleic acid, gluconic acid, 16-hydroxyhexadecanoic acid, 12-hydroxystearic acid, N - lauroylsarcosine, N-oleylsarcosine, oleylamine, octylamine, trioctylamine, hexadecylamine, octanethiol, dodecanethiol, hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), phenylphosphonic acid, and octylphosphine acid (OPA).

The organic ligand may be, for example, a compound represented by formula (L1) below.

[In the formula (L1), p represents an integer of 0 to 50, and q represents an integer of 0 to 50. ]

In the compound represented by formula (L1), at least one of p and q is preferably 1 or more, more preferably both p and q are 1 or more.

The organic ligand may be, for example, a compound represented by formula (L2) below.

[In formula (L2), A ¹ represents a monovalent group containing a carboxyl group, A ² represents a monovalent group containing a hydroxyl group, and R represents a hydrogen atom, a methyl group, or an ethyl group. , L represents a substituted or unsubstituted alkylene group, and r represents an integer of 0 or more. ]

The number of carboxyl groups in the monovalent group containing a carboxyl group may be 2 or more, 2 to 4, or 2.
The number of carbon atoms in the alkylene group represented by L may be, for example, 1-10. In the alkylene group represented by L, some of the carbon atoms may be substituted with hetero atoms, and at least one hetero atom selected from the group consisting of oxygen atoms, sulfur atoms and nitrogen atoms. good too.
r may be, for example, an integer of 1-100, or an integer of 10-20.

The organic ligand may be, for example, a compound represented by the following formula (L3) from the viewpoint of excellent external quantum efficiency of the pixel portion (cured product of the ink composition).

[In Formula (L3), r has the same definition as above. ]

The organic ligand may be, for example, a compound represented by formula (L4) below.

[In the formula (L4), n represents an integer of 0 to 50, and m represents an integer of 0 to 50. ]

n is preferably 0-20, more preferably 0-10. m is preferably 0-20, more preferably 0-10. At least one of n and m is preferably 1 or more. That is, n+m is preferably 1 or more. n+m is preferably 10 or less.
Z represents a substituted or unsubstituted alkylene group. The number of carbon atoms in the alkylene group may be, for example, 1-10. In the alkylene group represented by Z, some of the carbon atoms may be substituted with heteroatoms, and substituted with at least one heteroatom selected from the group consisting of oxygen atoms, sulfur atoms and nitrogen atoms. good too.

The organic ligand may be, for example, a compound represented by formula (L5) below.

[In the formula (L5), l represents an integer of 1 to 50. ]

In the organic ligand represented by formula (L5), l may be 1 to 20, 3 to 15, 5 to 10, or 7.

The content of the organic ligand in the ink composition is 10 parts by mass or more and 20 parts by mass with respect to 100 parts by mass of the luminescent nanocrystalline particles, from the viewpoint of the dispersion stability of the luminescent nanocrystalline particles and the maintenance of the light emission properties. Above, it may be 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, or 40 parts by mass or more.
From the viewpoint of easily keeping the viscosity of the ink composition low, the content of the organic ligand in the ink composition is 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, or It may be 30 parts by mass or less.
From these viewpoints, the content of the organic ligand in the ink composition may be, for example, 10 to 50 parts by mass, or even 10 to 15 parts by mass with respect to 100 parts by mass of the luminescent nanocrystalline particles. good.

Particles that can be dispersed in a colloidal form in an organic solvent, a photopolymerizable compound, or the like can be suitably used as the luminescent nanocrystalline particles. The surface of the luminescent nanocrystalline particles in the dispersed state is preferably passivated (modified) with the organic ligand. The organic solvent is as described below.
Commercially available products can also be used as the luminescent nanocrystalline particles. Commercially available luminescent nanocrystalline particles include, for example, indium phosphide/zinc sulfide, D-dot, CuInS/ZnS manufactured by NN-Labs, and InP/ZnS manufactured by Aldrich.

In addition, when cations are present on the surface of the nanocrystal, a ligand having a binding group that binds to the cation may be used, and the ligand can stabilize the surface of the nanocrystal.

Examples of the binding group include a carboxyl group, a carboxylic anhydride group, an amino group, an ammonium group, a mercapto group, a phosphine group, a phosphine oxide group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfonic acid group and At least one of boronic acid groups is preferred, and at least one of carboxyl and amino groups is more preferred. Examples of such ligands include carboxyl group- or amino group-containing compounds and the like, and these ligands can be used singly or in combination of two or more.

Examples of carboxyl group-containing compounds include linear or branched aliphatic carboxylic acids having 1 to 30 carbon atoms. Specific examples of such carboxyl group-containing compounds include arachidonic acid, crotonic acid, trans-2-decenoic acid, erucic acid, 3-decenoic acid, cis-4,7,10,13,16,19-docosahexaenoic acid. , 4-decenoic acid, all cis-5,8,11,14,17-eicosapentaenoic acid, all cis-8,11,14-eicosatrienoic acid, cis-9-hexadecenoic acid, trans-3-hexenoic acid , trans-2-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 2-hexadecenoic acid, linolenic acid, linoleic acid, γ-linolenic acid, 3-nonenoic acid, 2-nonenoic acid, trans-2-octenoic acid , petroselinic acid, elaidic acid, oleic acid, 3-octenoic acid, trans-2-pentenoic acid, trans-3-pentenoic acid, ricinoleic acid, sorbic acid, 2-tridecenoic acid, cis-15-tetracosenoic acid, 10-undecene acid, 2-undecenoic acid, acetic acid, butyric acid, behenic acid, cerotic acid, decanoic acid, arachidic acid, heneicosanoic acid, heptadecanoic acid, heptanoic acid, hexanoic acid, heptacosanoic acid, lauric acid, myristic acid, melisic acid, octacosanoic acid, Nonadecanic acid, nonacosanoic acid, n-octanoic acid, palmitic acid, isopalmitic acid, pentadecanoic acid, propionic acid, pentacosanoic acid, nonanoic acid, stearic acid, lignoceric acid, tricosanoic acid, tridecanoic acid, undecanoic acid, valeric acid, etc. be done.

Examples of amino group-containing compounds include linear or branched aliphatic amines having 1 to 30 carbon atoms. Specific examples of such amino group-containing compounds include 1-aminoheptadecane, 1-aminononadecane, heptadecane-9-amine, stearylamine, oleylamine, 2-n-octyl-1-dodecylamine, allylamine, and amylamine. , 2-ethoxyethylamine, 3-ethoxypropylamine, isobutylamine, isoamylamine, 3-methoxypropylamine, 2-methoxyethylamine, 2-methylbutylamine, neopentylamine, propylamine, methylamine, ethylamine, butylamine, hexylamine , heptylamine, n-octylamine, 1-aminodecane, nonylamine, 1-aminoundecane, dodecylamine, 1-aminopentadecane, 1-aminotridecane, hexadecylamine, tetradecylamine and the like.

In addition, the ligand having a bonding group that binds to the cation on the surface of the nanocrystal may be a silane compound containing Si and having a reactive group that forms a siloxane bond by hydrolysis. can further stabilize the nanocrystal surface.

As the reactive group, a hydrolyzable silyl group such as a silanol group or an alkoxysilyl group having 1 to 6 carbon atoms is preferable because a siloxane bond is easily formed.

Examples of binding groups include carboxyl groups, amino groups, ammonium groups, mercapto groups, phosphine groups, phosphine oxide groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, sulfonic acid groups, boronic acid groups, and the like. . Among them, the binding group is preferably at least one of a carboxyl group, a mercapto group and an amino group. These binding groups have a higher affinity for the cations contained in the nanocrystals than the reactive groups described above. Therefore, the ligands are coordinated with the bonding groups on the nanocrystal side, and the silica layer can be formed more easily and reliably.

As the silane compound containing Si and having a reactive group that forms a siloxane bond, one or more silicon compounds containing a bonding group can be used, or two or more can be used in combination.
Preferably, any one of a carboxyl group-containing silicon compound, an amino group-containing silicon compound, and a mercapto group-containing silicon compound is contained, or two or more of them can be used in combination.

Specific examples of carboxyl group-containing silicon compounds include 3-(trimethoxysilyl)propionic acid, 3-(triethoxysilyl)propionic acid, 2-, carboxyethylphenylbis(2-methoxyethoxy)silane, N- [3-(trimethoxysilyl)propyl]-N'-carboxymethylethylenediamine, N-[3-(trimethoxysilyl)propyl]phthalamide, N-[3-(trimethoxysilyl)propyl]ethylenediamine-N,N' , N′-triacetic acid and the like.

On the other hand, specific examples of amino group-containing silicon compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldipropoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiiso Propoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyl Tripropoxysilane, N-(2-aminoethyl)-3-aminopropyltriisopropoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, N-(2-aminoethyl)-3- Aminoisobutylmethyldimethoxysilane, N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylsilanetriol, 3-triethoxysilyl-N-(1 ,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N,N-bis[3-(trimethoxysilyl)propyl]ethylenediamine, (aminoethylaminoethyl)phenyltrimethoxysilane, (aminoethylaminoethyl)phenyltriethoxysilane, (aminoethylaminoethyl)phenyltripropoxysilane, (aminoethylaminoethyl)phenyltriisopropoxysilane, (aminoethylaminomethyl)phenyltrimethoxysilane, (aminoethylaminomethyl) ) phenyltriethoxysilane, (aminoethylaminomethyl)phenyltripropoxysilane, (aminoethylaminomethyl)phenyltriisopropoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, N -(vinylbenzyl)-2-aminoethyl-3-aminopropylmethyldimethoxysilane, N-β-(N-vinylbenzylaminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane , N-β-(N-di(vinylbenzyl)aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(N-di(vinylbenzyl) Dyl)aminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane, methylbenzylaminoethylaminopropyltrimethoxysilane, dimethylbenzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyl Trimethoxysilane, benzylaminoethylaminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, N,N-bis[3-(trimethoxysilyl)propyl]ethylenediamine , (aminoethylaminoethyl)phenethyltrimethoxysilane, (aminoethylaminoethyl)phenethyltriethoxysilane, (aminoethylaminoethyl)phenethyltripropoxysilane, (aminoethylaminoethyl)phenethyltriisopropoxysilane, (aminoethylamino methyl)phenethyltrimethoxysilane, (aminoethylaminomethyl)phenethyltriethoxysilane, (aminoethylaminomethyl)phenethyltripropoxysilane, (aminoethylaminomethyl)phenethyltriisopropoxysilane, N-[2-[3-( Trimethoxysilyl)propylamino]ethyl]ethylenediamine, N-[2-[3-(triethoxysilyl)propylamino]ethyl]ethylenediamine, N-[2-[3-(tripropoxysilyl)propylamino]ethyl]ethylenediamine , N-[2-[3-(triisopropoxysilyl)propylamino]ethyl]ethylenediamine and the like.

Specific examples of mercapto group-containing silicon compounds include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and 2-mercaptoethyl. trimethoxysilane, 2-mercaptoethyltriethoxysilane, 2-mercaptoethylmethyldimethoxysilane, 2-mercaptoethylmethyldiethoxysilane, 3-[ethoxybis(3,6,9,12,15-pentoxaoctacosane-1 -yloxy)silyl]-1-propanethiol and the like.

The silica layer can be formed by coordinating ligands such as oleic acid and 3-aminopropyltrimethoxysilane to the surface of the nanocrystals and further reacting with 3-aminopropyltrimethoxysilane. can.

The thickness of the silica layer is preferably 0.5-50 nm, more preferably 1.0-30 nm. A luminescent particle having such a thick silica layer can sufficiently improve the stability of the nanocrystal against heat and light.

The thickness of the silica layer can be changed by adjusting the number of atoms (chain length) of the connecting structure that connects the binding group and the reactive group of the ligand.

Specifically, the luminescent particles having a silica layer are composed of a solution containing a raw material compound of nanocrystals, a compound having a bonding group that binds to cations contained in the nanocrystals, and Si to form a siloxane bond. After mixing with a solution containing a compound having a reactive group to be obtained, the reactive group in the compound containing Si coordinated to the surface of the precipitated nanocrystal and having a reactive group capable of forming a siloxane bond is condensed. It can be easily produced by At this time, there are a method of manufacturing with heating and a method of manufacturing without heating.

First, a method for producing luminescent particles having a silica layer by heating will be described. Solutions containing two kinds of raw material compounds for synthesizing semiconductor nanocrystals by reaction are prepared respectively. At this time, a compound having a bonding group that binds to cations contained in the nanocrystals is added to one of the two solutions, and a compound containing Si and having a reactive group capable of forming a siloxane bond is added to the other. Keep These are then mixed under an inert gas atmosphere and reacted at a temperature of 140 to 260°C. Next, a method of precipitating nanocrystals by cooling to −20 to 30° C. and stirring may be used. The precipitated nanocrystals have a silica layer having siloxane bonds formed on the surface of the nanocrystals, and the nanocrystals can be obtained by a conventional method such as centrifugation.

Next, a method for producing luminescent particles having a silica layer without heating will be described. A solution containing a raw material compound for semiconductor nanocrystals and a compound having a bonding group that binds to a cation contained in the nanocrystal (excluding compounds containing Si and having a reactive group capable of forming a siloxane bond) was added to the solution containing Si. A method of precipitating nanocrystals by dropping and mixing a compound containing a reactive group capable of forming a siloxane bond in an organic solvent, which is a poor solvent for nanocrystals, in the atmosphere. mentioned. The amount of the organic solvent used is preferably 10 to 1000 times the mass of the semiconductor nanocrystals. In addition, the deposited nanocrystals have a silica layer having a siloxane bond formed on the surface of the nanocrystals, and can be obtained by a standard method such as centrifugation.

A silica layer may be additionally formed on the surface of the nanocrystal on which the shell layer having siloxane bonds is formed. When a silica layer is additionally formed, first, a silane compound is mixed with nanocrystals on which a silica layer having siloxane bonds is formed, and siloxane bonds are formed by hydrolysis to form a shell layer. In the case of additionally forming a silica layer, a reaction field is formed by adsorbing a polymer having a structural unit containing a basic group, and then a silane compound is mixed and hydrolyzed to form a siloxane bond to form a silica layer. good too.

The silane compound is preferably, for example, a compound represented by the following formula (C1).

In the formula, R ^C1 and R ^C2 each independently represent an alkyl group, R ^C3 and R ^C4 each independently represent a hydrogen atom or an alkyl group, n represents 0 or 1, m is an integer of 1 or more represents m is preferably an integer of 10 or less.

Specific examples of the compound represented by formula (C1) include tetrabutoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyl trimethoxysilane, phenyltrimethoxysilane, vinyltriethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyl trimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, n-dodecyltrimethoxysilane, n-dodecyltriethoxysilane, n-hexadecyltrimethoxysilane, n-hexadecyltriethoxysilane, n- Octadecyltrimethoxysilane, trimethoxy(3,3,3-trifluoropropyl)silane, trimethoxy(pentafluorophenyl)silane, trimethoxy(11-pentafluorophenoxyundecyl)silane, trimethoxy(1H,1H,2H,2H-nona) fluorohexyl)silane, partially hydrolyzed oligomers of tetramethoxysilane (product names: Methyl Silicate 51, Methyl Silicate 53A (manufactured by Colcoat Co., Ltd.)), partially hydrolyzed oligomers of tetraethoxysilane (product names: Ethyl Silicate 40, Examples include Ethyl Silicate 48 (manufactured by Colcoat Co., Ltd.), partially hydrolyzed oligomer of a mixture of tetramethoxysilane and tetraethoxysilane (product name: EMS-485 (manufactured by Colcoat Co., Ltd.)), and the like.

As the silane compound, in addition to the compound represented by the above formula (C1), for example, a compound represented by the following formula (C2) and a compound represented by (C3) can be used in combination.

In the formula, R ^C21 , R ^C22 and R ^C31 each independently represent an alkyl group, and R ^C23 , R ^C24 , R ^C32 , R ^C33 and R ^C34 each independently have a hydrogen atom and a substituent. may be an alkyl group, a phenyl group or a cyclohexyl group, the carbon atoms in the alkyl group may be substituted with an oxygen atom or a nitrogen atom, and m2 represents an integer of 1 or more and 10 or less.

Specific examples of the compound represented by formula (C2) and the compound represented by formula (C3) include dimethyldiethoxysilane, diphenyldimethoxysilane, methylethyldimethoxysilane, and trimethylmethoxysilane. The compounds represented by formula (C1) can be used singly or in combination of two or more. The compound represented by formula (C2) and the compound represented by (C3) can be used alone or in combination with the compound represented by general formula (C1).

The total thickness of the silica layers is preferably 0.5-50 nm, more preferably 1.0-30 nm. A luminescent nanocrystal having such a thickness of silica layer can sufficiently enhance the stability of the nanocrystal against heat and light. The thickness can be measured, for example, with a high-resolution electron microscope.

The total thickness of the silica layer can be changed by adjusting the number of atoms (chain length) of the connecting structure that connects the binding group and the reactive group of the ligand.

From the viewpoint of further improving the external quantum efficiency of the light conversion layer, the content of the luminescent nanocrystalline particles in the ink composition is 0.00 parts per 100 parts by mass in total of the components other than the organic solvent contained in the ink composition. It is preferably 1 part by mass or more, 1 part by mass or more, 5 parts by mass or more, 10 parts by mass or more, 20 parts by mass or more, or 30 parts by mass or more. From the viewpoint of further improving the coating properties, ejection stability, and external quantum efficiency of the light conversion layer, the content of the luminescent nanocrystalline particles in the ink composition is It is preferably 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less.

From the viewpoint of further improving the external quantum efficiency of the light conversion layer, the content of the luminescent nanocrystalline particles in the ink composition used as the pixel portion of the color filter is It is preferably 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, or 30 parts by mass or more with respect to a total of 100 parts by mass. From the viewpoint of further improving the ejection stability and the external quantum efficiency of the pixel portion, the content of the luminescent nanocrystalline particles in the ink composition used as the pixel portion of the color filter is 100% of the components other than the organic solvent. It is preferably 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less.

In addition, the content of the luminescent nanocrystalline particles in the ink composition used as the light conversion layer in the sheet-like light conversion film is adjusted from the viewpoint of further improving the external quantum efficiency of the light conversion layer. It is 0.1 parts by mass or more, 0.5 parts by mass or more, 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more with respect to the total 100 parts by mass of the components other than the organic solvent contained therein. preferable. The content of the luminescent nanocrystalline particles in the ink composition used as the light conversion layer in the sheet-like light conversion film is the above organic solvent from the viewpoint of further improving the coatability and the external quantum efficiency of the light conversion layer. It is preferably 15 parts by mass or less, 12.5 parts by mass or less, 10 parts by mass or less, 7.5 parts by mass or less, or 5 parts by mass or less with respect to a total of 100 parts by mass of the other components.

When the luminescent nanocrystalline particles contain a metal halide, the content of the luminescent nanocrystalline particles in the ink composition is the same as that of the components other than the organic solvent contained in the ink composition, from the viewpoint of further improving the external quantum efficiency of the light conversion layer. It is preferably 0.1 parts by mass or more, 0.5 parts by mass or more, 1 part by mass or more, or 5 parts by mass or more with respect to a total of 100 parts by mass. The content of the luminescent nanocrystalline particles in the ink composition is 100 mass in total of the components other than the organic solvent contained in the ink composition, from the viewpoint of further improving the coatability, the ejection stability, and the external quantum efficiency of the light conversion layer. It is preferably 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, or 10 parts by mass or less.

In this specification, the term “components other than the organic solvent contained in the ink composition” may be replaced with components constituting the cured product of the ink composition. The “total of components other than the organic solvent contained in the ink composition” can be, for example, the total of the luminescent nanocrystalline particles, the photopolymerizable compound, and the hindered amine compound.
Also, the organic solvent is a component that is added as necessary for the purpose of adjusting the viscosity of the ink composition, and may not be added to the ink composition.

The content of the luminescent nanocrystalline particles based on the total mass of the ink composition is 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 5% by mass or more, from the viewpoint of further improving the external quantum efficiency. % by mass or more, preferably 10% by mass or more. The content of the luminescent nanocrystalline particles based on the total mass of the ink composition is 36% by mass or less, 34% by mass or less, or 32% by mass or less from the viewpoint of improving the coating properties, ejection stability, and external quantum efficiency. , 30% by mass or less, preferably 28% by mass or less.

The ink composition of the present invention may contain, as luminescent nanocrystalline particles, two or more of red luminescent nanocrystalline particles, green luminescent nanocrystalline particles and blue luminescent nanocrystalline particles. It may contain seeds only.
When the ink composition contains red-emitting nanocrystalline particles, the content of green-emitting nanocrystalline particles and the content of blue-emitting nanocrystalline particles are 0% by weight, based on the total weight of the luminescent nanocrystalline particles. 50% by mass or less is preferable, 0% by mass or more and 25% by mass or less is more preferable, and 0% by mass or more and 10% by mass or less is particularly preferable.
When the ink composition contains green luminescent nanocrystalline particles, the content of red luminescent nanocrystalline particles and the content of blue luminescent nanocrystalline particles are 0% by weight, based on the total mass of luminescent nanocrystalline particles. 50% by mass or less is preferable, 0% by mass or more and 25% by mass or less is more preferable, and 0% by mass or more and 10% by mass or less is particularly preferable.

[Photopolymerizable component]
As described above, the photopolymerizable component has at least a Hansen solubility parameter δD of 16 to 17.5 MPa ^0.5 , δP of 2.5 to 5 MPa ^0.5 and δH of 3 to 6 MPa ^0.5 It contains one photopolymerizable compound.
Here, the Hansen solubility parameter is a parameter obtained by dividing the solubility parameter introduced by Hildebrand into three components δD, δP and δH and expressing them in a three-dimensional space.
δD indicates the effect of non-polar interaction, δP indicates the effect of dipole-dipole force, and δH indicates the effect of hydrogen bonding force.

Hansen Solubility Parameter values for various compounds can be found, for example, in Charles M. et al. Hansen, "Hansen Solubility Parameters: A Users Handbook". Hansen solubility parameter values for compounds not listed were also obtained using computer software (Hansen
Solubility Parameters in Practice (HSPiP)).

δD is preferably 16 to 17.3 MPa ^0.5 , more preferably 16.1 to 17.2 MPa ^0.5 . δP is preferably 2.7 to 4.5 MPa ^0.5 , more preferably 3 to 4 MPa ^0.5 . δH is preferably 3 to 5.5 MPa ^0.5 , more preferably 3.1 to 5.1 MPa ^0.5 .
By using a photopolymerizable compound having such a Hansen solubility parameter, affinity with both the luminescent nanocrystalline particles and the hindered amine compound can be enhanced.
The photopolymerizable component may contain a photopolymerizable compound in which at least one of δD, δP and δH of the Hansen solubility parameters deviates from the above range.

A photopolymerizable compound is a compound that polymerizes by irradiation with light, and is, for example, a radical photopolymerizable compound or a cationic photopolymerizable compound. The photopolymerizable compound may be either a photopolymerizable monomer or a photopolymerizable oligomer (hereinafter collectively referred to as "photopolymerizable monomer").
These photopolymerizable compounds are preferably used together with a photoinitiator. A radical photopolymerizable compound is used together with a radical photopolymerization initiator, and a cationic photopolymerizable compound is used together with a cationic photopolymerization initiator. In other words, the photopolymerizable component can contain a photopolymerizable compound and a photoinitiator.
As the photopolymerizable compound, a photoradical polymerizable compound and a photocationically polymerizable compound may be used in combination, or a compound having both photoradical polymerizability and photocationic polymerizability may be used. As the photopolymerization initiator, a radical photopolymerization initiator and a cationic photopolymerization initiator may be used in combination.

Examples of photoradically polymerizable compounds include monomers having an ethylenically unsaturated group (hereinafter also referred to as "ethylenically unsaturated monomers"), monomers having an isocyanate group, and the like.
Here, the ethylenically unsaturated monomer means a monomer having an ethylenically unsaturated bond (carbon-carbon double bond). Examples of ethylenically unsaturated monomers include monomers having ethylenically unsaturated groups such as vinyl groups, vinylene groups, and vinylidene groups. Monomers having these groups are sometimes referred to as "vinyl monomers".

The number of ethylenically unsaturated bonds (for example, the number of ethylenically unsaturated groups) in the ethylenically unsaturated monomer is preferably 1-3. An ethylenically unsaturated monomer may be used individually by 1 type, or may use 2 or more types together.
The ethylenically unsaturated monomer is a monomer having one or two ethylenically unsaturated groups, and ethylene and monomers having two or three polyunsaturated groups. That is, the ethylenically unsaturated monomer is at least selected from the group consisting of a combination of a monofunctional monomer and a bifunctional monomer, a combination of a monofunctional monomer and a trifunctional monomer, and a combination of a bifunctional monomer and a trifunctional monomer. It can be a combination.

Examples of ethylenically unsaturated groups include vinyl, vinylene and vinylidene groups, as well as (meth)acryloyl groups.
In addition, in this specification, a "(meth)acryloyl group" means an "acryloyl group" and a "methacryloyl group" corresponding thereto. The same applies to expressions such as "(meth)acrylate" and "(meth)acrylamide".
The photopolymerizable compound preferably contains a compound having a (meth)acryloyl group as an ethylenically unsaturated group, more preferably (meth)acrylate and (meth)acrylamide, and a monofunctional or polyfunctional (meth)acrylate. It is even more preferable to have (Meth)acrylates are preferred because many compounds have Hansen solubility parameters in the above range.

Specific examples of monofunctional or polyfunctional (meth)acrylates include dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, dipropylene glycol diacrylate (DPGDA), 1,6 -hexanediol dimethacrylate (HDDMA), 1,6-hexanediol diacrylate (HDDA), and the like.
Among them, the photopolymerizable compound is particularly preferably a bifunctional (meth)acrylate represented by the following formula (1).

[In formula (1), R ¹ represents an alkylene group having 4 to 8 carbon atoms, and two R ² independently represent a hydrogen atom or a methyl group. ]
Part of the carbon atoms constituting R ¹ may be substituted with an oxygen atom, a sulfur atom, a nitrogen atom, or the like.

Examples of photo-cationically polymerizable compounds include epoxy compounds, oxetane compounds, and vinyl ether compounds.
The photopolymerizable compound is preferably alkali-insoluble from the viewpoint of easily obtaining a highly reliable pixel portion (cured product of the ink composition).
Here, in this specification, the photopolymerizable compound being alkali-insoluble means that the amount of the photopolymerizable compound dissolved in a 1% by mass aqueous potassium hydroxide solution at 25° C. is based on the total mass of the photopolymerizable compound. As, it means that it is 30% by mass or less.
The dissolved amount of the photopolymerizable compound is preferably 10% by mass or less, more preferably 3% by mass or less.

The content of the photopolymerizable compound in the ink composition is determined from the viewpoint of easily obtaining an appropriate viscosity as an inkjet ink, from the viewpoint of improving the curability of the ink composition, and from the viewpoint of the durability of the pixel portion (cured product of the ink composition). From the viewpoint of improving solvent resistance and abrasion resistance, it is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and 20 parts by mass with respect to the total 100 parts by mass of the components other than the organic solvent. More preferably, it is at least 1 part.
The content of the photopolymerizable compound is a total of 100 parts by mass of the components other than the organic solvent, from the viewpoint of easily obtaining an appropriate viscosity as an inkjet ink and from the viewpoint of obtaining better light emission characteristics (e.g., external quantum efficiency). is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

The proportion of the photopolymerizable compound in the photopolymerizable component should be 30% by mass or more from the viewpoint of enhancing the dispersion stability of the luminescent nanocrystalline particles and facilitating the production of a pixel portion with excellent shape stability. is preferred, 45% by mass or more is more preferred, and 60% by mass or more is even more preferred.
The upper limit of the proportion of the photopolymerizable compound in the photopolymerizable component is not particularly limited, but is preferably less than 100% by mass, more preferably 90% by mass or less, and even more preferably 80% by mass or less. .

[Photoinitiator]
The photopolymerization initiator is, for example, a radical photopolymerization initiator or a cationic photopolymerization initiator.
As the photoradical polymerization initiator, a molecular cleavage type or hydrogen abstraction type photoradical polymerization initiator is suitable.

Molecular cleavage type photoradical polymerization initiators include, for example, benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino -1-(4-morpholinophenyl)-butan-1-one, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenyl Phosphine oxide and the like can be preferably used.
Other molecular cleavage type radical photopolymerization initiators include 1-hydroxycyclohexylphenyl ketone, benzoin ethyl ether, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4 -isopropylphenyl)-2-hydroxy-2-methylpropan-1-one and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one may be used in combination.

Hydrogen abstraction type photoradical polymerization initiators include, for example, benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4′-methyl-diphenylsulfide and the like.
As the photopolymerization initiator, a molecular cleavage type photoradical polymerization initiator and a hydrogen abstraction type photoradical polymerization initiator may be used in combination.

A commercial item can also be used for a photocationic polymerization initiator.
Examples of commercially available photocationic polymerization initiators include, for example, sulfonium salt photocationic polymerization initiators such as “CPI-100P” manufactured by San-Apro Co., Ltd., and “Lucirin” manufactured by BASF.
TPO", "Irgacure 907", "Irgacure 819", "Irgacure 379EG", "Irgacure 184" and "Irgacure PAG290" manufactured by BASF.

From the viewpoint of the curability of the ink composition, the content of the photopolymerization initiator in the ink composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass, with respect to 100 parts by mass of the photopolymerizable compound. It is more preferably at least 1 part by mass, even more preferably at least 1 part by mass, particularly preferably at least 3 parts by mass, and most preferably at least 5 parts by mass.
The content of the photopolymerization initiator is preferably 40 parts by mass or less and 30 parts by mass with respect to 100 parts by mass of the photopolymerizable compound, from the viewpoint of the temporal stability of the pixel portion (cured product of the ink composition). It is more preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less.

[Hindered amine compound]
The hindered amine compound has a function of preventing deterioration of the luminescent nanocrystalline particles by trapping deterioration promoting substances such as ions, radicals, and peroxides generated in the ink composition by the action of ultraviolet rays or visible light. have.
The hindered amine compound preferably has a partial structure represented by the following formula (2).

Examples of the substituent R ³ include a hydroxyl group, —O., an alkyl group, an alkoxy group and the like, and an alkoxy group is preferred.
The number of carbon atoms in the alkyl group or alkoxy group is preferably 1-20. In addition, one or two or more non-adjacent -CH ₂ - present in an alkyl group or an alkoxy group each independently represent -O-, -S-, -CO-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH -OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -C≡C-, -Si(CH ₃ ) ₂ -, trans 1,4-cyclohexylene group, It may be substituted with a 1,4-phenylene group or a naphthalene-2,6-diyl group.
Furthermore, one or more hydrogen atoms in R ³ may each independently be substituted with a fluorine atom, a chlorine atom or a cyano group.

The hindered amine compound is preferably a compound represented by (3) below.

[In the formula (3), M represents an alkylene group having 1 to 15 carbon atoms. provided that one or more —CH ₂ — present in M is —O—, —CH═CH—, —C≡C—, —CO—, —OCO—, —COO—, trans-1,4 -Cyclohexylene group, 1,4-phenylene group and naphthalene-2,6-diyl group. ]

In formula (3), two R ³ are each independently preferably an alkoxy group having 1 to 15 carbon atoms, more preferably an alkoxy group having 1 to 8 carbon atoms.
In formula (3), M represents an alkylene group having 1 to 15 carbon atoms. However, considering the viscosity imparted to the ink composition and its own volatility, M is preferably an alkylene group having 2 to 10 carbon atoms, more preferably an alkylene group having 4 to 8 carbon atoms. It is more preferably an alkylene group of number 6 or 8.

[Antioxidant]
The ink composition preferably further contains an antioxidant.
The antioxidant is a compound having a function of imparting excellent external quantum efficiency maintenance performance to the pixel portion.
The antioxidant is not particularly limited, and examples thereof include phenol antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, and the like. Among them, the antioxidant is preferably a phenol-based antioxidant or a phosphorus-based antioxidant. In addition, these antioxidants may be used individually by 1 type, or may use 2 or more types together.

Phenolic antioxidants are also commonly referred to as hindered phenolic compounds.
Examples of such phenolic antioxidants include pentaerythritol tetrakis[3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionate], 2,6-di-t-butyl-p-cresol , 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-t-butyl-4-hydroxyphenyl)-propionate, distearyl (3,5-di-t-butyl-4-hydroxy benzyl)phosphonate, thiodiethylene glycol bis[(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylenebis[(3,5-di-t-butyl-4-hydroxyphenyl) ) propionate], 1,6-hexamethylenebis[(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], 4,4′-thiobis(6-t-butyl-m-cresol) , 2,2′-methylenebis(4-methyl-6-t-butylphenol), 2,2′-methylenebis(4-ethyl-6-t-butylphenol), bis[3,3-bis(4-hydroxy-3 -t-butylphenyl)butyric acid]glycol ester, 4,4′-butylidenebis(6-t-butyl-m-cresol), 2,2′-ethylidenebis(4,6-di-t-butylphenol), 2,2′-ethylidenebis(4-sec-butyl-6-t-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, bis[2- t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl]terephthalate, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4- t-butylbenzyl)isocyanurate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3,5-di- t-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, Tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane, 2-t-butyl-4-methyl-6-(2-acryloyloxy-3-t -butyl-5-methylbenzyl)phenol, 3,9-bis[1,1 -dimethyl-2-{(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, triethylene glycol bis [(3-t-butyl-4-hydroxy-5-methylphenyl)propionate] and the like.
Among them, pentaerythritol tetrakis[3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionate] is preferable as the phenolic antioxidant because of its excellent solubility in the ink composition.

As the phosphorus antioxidant, a phosphite triester compound is preferred.
A phosphite triester compound is, for example, a compound represented by the formula: P(OR ⁵ ) ₃ . ^In the formula, three R5's each independently represent a monovalent organic group. Also, two ^R5 's out of the ^three R5's may be bonded to each other to form a ring structure.
The monovalent organic group sufficiently satisfies performance such as affinity with other components (photopolymerizable compound, etc.) in the ink composition, and from the viewpoint of being able to maintain excellent external quantum efficiency of the pixel portion, A monovalent hydrocarbon group is preferred.
Examples of monovalent hydrocarbon groups include alkyl groups, aryl groups, and alkenyl groups. The number of carbon atoms in the monovalent hydrocarbon group is preferably 1 to 30, more preferably 4 to 18 from the viewpoint of solubility in the ink composition.

Alkyl groups may be straight or branched. Examples of alkyl groups include 2-ethylhexyl group, butyl group, octyl group, nonyl group, decyl group, isodecyl group, dodecyl group, hexadecyl group, octadecyl group and the like.
Examples of aryl groups include phenyl, naphthyl, tert-butylphenyl, di-tert-butylphenyl, octylphenyl, nonylphenyl, isodecylphenyl, isodecylphenyl, and isodecylnaphthyl groups. are mentioned.
The monovalent hydrocarbon group is preferably an alkyl group or an aryl group, more preferably an alkyl group or a phenyl group, from the viewpoint of maintaining excellent external quantum efficiency of the pixel portion.

Preferably, at ^least two of the three R5's are identical to each other.
Preferably, at ^least one of the three R5's is a phenyl group, more preferably at least two are phenyl groups.
It is preferred that at ^least one of the three R5's is a phenyl group and one is an alkyl group (particularly a branched alkyl group). That is, the phosphite triester compound preferably has at least one phenyl group and one alkyl group.
When the phosphite triester compound has the above functional group, it sufficiently satisfies performance such as affinity with other components (photopolymerizable compound, etc.) in the ink composition, and reduces the external quantum efficiency of the pixel portion. can be suppressed.

Specific examples of the compound represented by the above formula include triphenyl phosphite (triphenylphosphite), 2-ethylhexyldiphenylphosphite, diphenyloctylphosphite and the like.
The phosphite triester-based compound may be liquid or solid at room temperature (25° C.), but it may have a similar affinity with other components (photopolymerizable compound, etc.) in the ink composition. It is preferably liquid at room temperature (25° C.) from the viewpoint of sufficiently satisfying the above performance and suppressing a decrease in the external quantum efficiency of the pixel portion.
The melting point of the phosphite triester compound is preferably 20° C. or lower, more preferably 10° C. or lower.

The content of the antioxidant in the ink composition is preferably 0.01 parts by mass or more with respect to 100 parts by mass of the photopolymerizable component, from the viewpoint of suppressing a decrease in the external quantum efficiency of the pixel portion. It is more preferably 0.1 parts by mass or more, further preferably 0.5 parts by mass or more, particularly preferably 1 part by mass or more, and most preferably 3 parts by mass or more.
Even if the antioxidant is added in a small amount, it is possible to effectively suppress the deterioration of the external quantum efficiency of the pixel portion. Therefore, the content of the antioxidant is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and 5 parts by mass or less with respect to 100 parts by mass of the photopolymerizable component. is more preferred.

[Light scattering particles]
The ink composition may further contain light scattering particles.
Light-scattering particles are, for example, optically inactive inorganic particles. When the ink composition contains light-scattering particles, it is possible to scatter the light from the light source irradiated to the pixel portion, so excellent optical properties (eg, external quantum efficiency) can be obtained.

Materials constituting the light-scattering particles include, for example, simple elements such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum, and gold, silicon oxide, barium sulfate, barium carbonate, and carbonic acid. Oxides such as calcium, talc, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, alumina white, titanium oxide, magnesium oxide, barium oxide, aluminum oxide, bismuth oxide, zirconium oxide, zinc oxide, magnesium carbonate, carbonate Carbonates such as barium, bismuth subcarbonate, calcium carbonate, hydroxides such as aluminum hydroxide, complex oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, strontium titanate, Metal salts such as bismuth subnitrate and the like are included.

The light-scattering particles are titanium oxide, aluminum oxide, zirconium oxide, zinc oxide, calcium carbonate, and barium sulfate, from the viewpoint of excellent dispersion stability and ejection stability of the ink composition, and from the viewpoint of improving the external quantum efficiency. , barium titanate and silicon oxide, preferably at least one selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide and barium titanate. preferable.

The shape of the light-scattering particles includes, for example, spherical, filamentary, and irregular shapes. However, the shape of the light-scattering particles is preferably a shape with less directivity (for example, a spherical shape, a regular tetrahedral shape, etc.). By using light-scattering particles having such a shape, the uniformity, fluidity and light-scattering properties of the ink composition can be further improved, and excellent dispersion stability and ejection stability can be ensured.

The average particle diameter (volume average diameter) of the light-scattering particles is preferably 0.05 μm or more, more preferably 0.2 μm, from the viewpoints of excellent dispersion stability and ejection stability and excellent effect of improving external quantum efficiency. It is more preferably 0.3 μm or more, and further preferably 0.3 μm or more.
From the viewpoint of excellent dispersion stability and ejection stability, the average particle size of the light-scattering particles is preferably 1 μm or less, more preferably 0.6 μm or less, and further preferably 0.4 μm or less. preferable.

The average particle size of the light scattering particles is 0.05 to 1 μm, 0.05 to 0.6 μm, 0.05 to 0.4 μm, 0.2 to 1 μm, 0.2 to 0.6 μm, 0.2 to It is preferably 0.4 μm, 0.3-1 μm, 0.3-0.6 μm or 0.3-0.4 μm.
In the present specification, the average particle diameter of the light scattering particles is obtained by measuring with a dynamic light scattering Nanotrack particle size distribution meter and calculating the volume average diameter.
The average particle size of the light-scattering particles to be used can be obtained, for example, by measuring the particle size of each particle with a transmission electron microscope or scanning electron microscope and calculating the volume average size.

From the viewpoint of improving the external quantum efficiency of the light conversion layer, the content of the light-scattering particles in the ink composition is 0.00 parts per 100 parts by mass of the components other than the organic solvent contained in the ink composition. It is preferably 1 part by mass or more, more preferably 1 part by mass or more, and even more preferably 3 parts by mass or more.
The content of the light-scattering particles is 100 mass in total of the components other than the organic solvent contained in the ink composition, from the viewpoint of excellent dispersion stability and ejection stability and from the viewpoint of improving the external quantum efficiency of the light conversion layer. It is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

The mass ratio of the content of the light-scattering particles to the content of the luminescent nanocrystalline particles (light-scattering particles/luminescent nanocrystalline particles) is 0.5 from the viewpoint of improving the external quantum efficiency of the light conversion layer. It is preferably 1 or more, more preferably 0.2 or more, and even more preferably 0.5 or more.
The above mass ratio (light-scattering particles/luminescent nanocrystalline particles) is 5 or less from the viewpoint of excellent effect of improving the external quantum efficiency of the light conversion layer, and particularly excellent continuous ejection property (ejection stability) in the inkjet method. is preferably , more preferably 2 or less, and even more preferably 1.5 or less.

The total amount of the luminescent nanocrystalline particles and the light-scattering particles in the ink composition is 100 parts by mass of the components other than the organic solvent contained in the ink composition, from the viewpoint of easily obtaining an appropriate viscosity as an inkjet ink. On the other hand, it is preferably 20 parts by mass or more, more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more.
The total amount of the luminescent nanocrystalline particles and the light-scattering particles in the ink composition is 100 parts by mass of the components other than the organic solvent contained in the ink composition, from the viewpoint of easily obtaining an appropriate viscosity as an inkjet ink. On the other hand, it is preferably 75 parts by mass or less, more preferably 65 parts by mass or less, and even more preferably 55 parts by mass or less.

[Polymer dispersant]
The ink composition may further contain a polymeric dispersant.
The polymeric dispersant is preferably a polymeric compound having a weight-average molecular weight of 750 or more and having a functional group having affinity for the light-scattering particles.
The polymeric dispersant has a function of stably dispersing the light-scattering particles in the ink composition. The polymer dispersant adsorbs to the light-scattering particles via a functional group that has an affinity for the light-scattering particles, and electrostatic repulsion and/or steric repulsion between the polymer dispersants causes light-scattering properties. The particles are dispersed in the ink composition.

When the ink composition contains a polymer dispersant, even when the content of the light-scattering particles is relatively large (for example, about 60% by mass), the light-scattering particles are well dispersed. be able to.
The polymeric dispersant is preferably bound to the surface of the light-scattering particles. However, the polymeric dispersant may be bound to the surface of the luminescent nanocrystalline particles or may be free in the ink composition.
Functional groups that have an affinity for light scattering particles include acidic functional groups, basic functional groups and nonionic functional groups. Acidic functional groups have dissociative protons and may be neutralized with bases such as amines and hydroxide ions, while basic functional groups are neutralized with acids such as organic acids and inorganic acids. It may be neutralized.

Examples of acidic functional groups include carboxyl group (--COOH), sulfo group (--SO ₃ H), sulfate group (--OSO ₃ H), phosphonic acid group (--PO(OH) ₃ ), phosphoric acid group (--OPO ( OH) ₃ ), phosphinic acid group (--PO(OH)--), mercapto group (--SH) and the like.
Basic functional groups include primary, secondary and tertiary amino groups, ammonium groups, imino groups, and nitrogen-containing heterocyclic groups such as pyridine, pyrimidine, pyrazine, imidazole and triazole.
Nonionic functional groups include hydroxy group, ether group, thioether group, sulfinyl group (-SO-), sulfonyl group ( _-SO2- ), carbonyl group, formyl group, ester group, carbonate group, amide group, Carbamoyl group, ureido group, thioamide group, thioureido group, sulfamoyl group, cyano group, alkenyl group, alkynyl group, phosphine oxide group, phosphine sulfide group and the like.

The polymeric dispersant may be a polymer (homopolymer) of a single monomer, or a copolymer (copolymer) of a plurality of types of monomers.
Moreover, the polymeric dispersant may be any of random copolymers, block copolymers and graft copolymers. When the polymeric dispersant is a graft copolymer, it may be a comb-shaped graft copolymer or a star-shaped graft copolymer.
Examples of polymer dispersants include acrylic resins, polyester resins, polyurethane resins, polyamide resins, polyethers, phenol resins, silicone resins, polyurea resins, amino resins, epoxy resins, polyamines such as polyethyleneimine and polyallylamine, and polyimides. etc.

A commercial item can also be used for a polymeric dispersing agent.
Commercially available polymeric dispersants include, for example, Ajinomoto Fine-Techno Co., Inc.'s Ajisper PB series, BYK's DISPERBYK series and BYK-series, and BASF's Efka series.

[Organic solvent]
The ink composition may contain an organic solvent, if desired.
Examples of organic solvents include ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol dibutyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, and succinic acid. diethyl, 1,4-butanediol diacetate, glyceryl triacetate and the like.

When used for inkjet ink, the boiling point of the organic solvent is preferably 150° C. or higher, more preferably 180° C. or higher, from the viewpoint of continuous ejection stability.
Further, when forming the pixel portion, it is necessary to remove the solvent from the ink composition before the ink composition is cured. Therefore, from the viewpoint of easy removal of the organic solvent, the boiling point of the organic solvent is preferably 300° C. or less. preferable.

The organic solvent preferably contains an acetate compound having a boiling point of 150° C. or higher. In this case, the affinity between the luminescent nanocrystalline particles and the organic solvent is further improved, and the luminescent nanocrystalline particles can exhibit excellent luminous properties.
Specific examples of such acetate compounds include monoacetate compounds such as diethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, and propylene. Diacetate compounds such as glycol diacetate, glyceryl triacetate, and the like are included.

In the ink composition of the present embodiment, since the photopolymerizable compound also functions as a dispersion medium, it is possible to disperse the light-scattering particles and the luminescent nanocrystalline particles without a solvent. In this case, there is an advantage that the step of removing the organic solvent by drying is not required when forming the pixel portion.
The ink composition may further contain components other than the components described above as long as the effects of the present invention are not impaired.

From the viewpoint of ejection stability, the ink composition may have a viscosity of 2 mPa·s or more, 5 mPa·s or more, or 7 mPa·s or more. The viscosity during ejection may be 20 mPa·s or less, 15 mPa·s or less, or 12 mPa·s or less.
The viscosity of the ink composition during ejection is 2 to 20 mPa·s, 2 to 15 mPa·s, 2 to 12 mPa·s, 5 to 20 mPa·s, 5 to 15 mPa·s, 5 to 12 mPa·s, and 7 to 20 mPa·s. s, 7 to 15 mPa·s or 7 to 12 mPa·s.
As used herein, the viscosity of the ink composition is a value measured at 25° C. using an E-type viscometer.

When the viscosity of the ink composition during ejection is 2 mPa·s or more, the meniscus shape of the ink composition at the tip of the ink ejection hole of the ejection head is stabilized. timing control) becomes easier.
On the other hand, when the ink composition has a viscosity of 20 mPa·s or less during ejection, the ink composition can be smoothly ejected from the ink ejection holes.

The surface tension of the ink composition is preferably a surface tension suitable for inkjet inks, specifically preferably 20 to 40 mN/m, more preferably 25 to 35 mN/m. By adjusting the surface tension to such a range, it is possible to facilitate ejection control of the ink composition (for example, control of the ejection amount and ejection timing) and to suppress the occurrence of flight deflection.
The term "flight deflection" means that when the ink composition is ejected from the ink ejection holes, the landing position of the ink composition deviates from the target position by 30 μm or more.

When the surface tension is 40 mN/m or less, the meniscus shape of the ink composition at the tip of the ink ejection hole is stabilized, so that the ejection control of the ink composition (for example, control of ejection amount and ejection timing) becomes easy. .
On the other hand, when the surface tension is 20 mN/m or more, it is possible to prevent the periphery of the ink ejection hole from being contaminated with the ink composition, so it is possible to suppress the occurrence of flight deflection. That is, the ink composition does not land accurately in the formation region of the pixel portion to be landed, and a pixel portion is insufficiently filled with the ink composition, or a pixel portion formation region adjacent to the pixel portion formation region to be landed (or It is possible to prevent the ink composition from landing on the pixel portion) and lowering the color reproducibility.
In the specification of the present application, the surface tension of the ink composition is a value measured at 23° C. using the ring method (also referred to as ring ring method).

When the ink composition of the present embodiment is used as an inkjet ink, it is preferably applied to a piezo-type inkjet recording apparatus. In the piezo method, the ink composition is not instantaneously exposed to high temperatures during ejection. Therefore, the luminescent nanocrystalline particles are less likely to be degraded, and desired light emission characteristics can be easily obtained in the pixel portion (light conversion layer).
Although one embodiment of the ink composition has been described above, the ink composition of the embodiment described above can also be used in, for example, a photolithography method in addition to the inkjet method. In this case, the ink composition preferably contains an alkali-soluble resin as a binder polymer.

When the ink composition is used in photolithography, first, the ink composition is applied onto a substrate, and the ink composition is dried to form a coating film. The resulting coating film is soluble in an alkaline developer, and is patterned by being treated with an alkaline developer. At this time, since an aqueous solution is preferably used as the alkaline developer from the viewpoint of ease of waste liquid treatment, the coating film of the ink composition is treated with an aqueous solution.
On the other hand, in the case of an ink composition using luminescent nanocrystalline particles (quantum dots, etc.), the luminescent nanocrystalline particles are unstable against water, and there is a risk that the luminescent properties (e.g., fluorescence properties) may be impaired by moisture. There is Since the ink composition of the present invention contains a hindered amine-based compound, it is possible to reduce the occurrence of such inconveniences, but it is preferably used in an inkjet method that does not require treatment with an alkaline developer (aqueous solution).

Further, even when the coating film of the ink composition is not treated with an alkaline developer, if the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere. Luminescent nanocrystalline particles (such as quantum dots) may lose their luminescent properties (eg, fluorescence properties) over time. Since the ink composition of the present invention contains a hindered amine compound, it is possible to suitably reduce the occurrence of such inconveniences.
In the present embodiment, the coating film of the ink composition is preferably alkali-insoluble from the viewpoint of more reliably reducing the occurrence of problems due to water absorption. That is, the ink composition of the present embodiment is preferably an ink composition capable of forming an alkali-insoluble coating film.

Such an ink composition can be obtained by using an alkali-insoluble photopolymerizable compound as the photopolymerizable compound.
Here, the fact that the coating film of the ink composition is alkali-insoluble means that the amount of dissolution of the coating film of the ink composition in a 1% by mass aqueous solution of potassium hydroxide at 25° C. is the total mass of the coating film of the ink composition. As a standard, it means 30% by mass or less. The dissolved amount is preferably 10% by mass or less, more preferably 3% by mass or less.
It should be noted that the fact that the ink composition is an ink composition capable of forming an alkali-insoluble coating film means that the thickness obtained by applying the ink composition on a substrate and then drying it under the conditions of 80 ° C. and 3 minutes It can be confirmed by measuring the amount of dissolution of the coating film of 1 μm.

<Method for producing ink composition>
The ink composition of the present embodiment includes, for example, the above-described components (luminescent nanocrystalline particles (e.g., organic ligand-modified luminescent nanocrystalline particles), photopolymerizable compounds, hindered amine compounds, and other optional component).
The method for producing the ink composition may further comprise a step of subjecting the mixture of the constituent components to dispersion treatment.
As an example, a method for producing an ink composition containing light-scattering particles will be described below.

A method for producing an ink composition containing light-scattering particles includes, for example, a first step of preparing a dispersion of light-scattering particles, and a second step of mixing the dispersion of light-scattering particles and luminescent nanocrystalline particles. 2 steps.
The dispersion of light scattering particles may further contain a polymeric dispersant. In this method, the dispersion of light-scattering particles may further contain a photopolymerizable compound, and the photopolymerizable compound may be further mixed in the second step.
According to the above method, the light-scattering particles can be sufficiently dispersed. Therefore, it is possible to improve the optical properties (for example, external quantum efficiency) of the pixel portion, and to easily obtain an ink composition having excellent ejection stability.

In the first step, light-scattering particles may be mixed with, if necessary, a polymer dispersant, and a photopolymerizable compound, and subjected to dispersion treatment to prepare a dispersion of light-scattering particles. good.
Mixing and dispersing treatments can be performed using, for example, dispersing devices such as bead mills, paint conditioners, planetary stirrers, jet mills, and the like. It is preferable to use a bead mill or a paint conditioner from the viewpoint of improving the dispersibility of the light-scattering particles and facilitating adjustment of the average particle size of the light-scattering particles to a desired range.
Further, by mixing the light-scattering particles and the polymer dispersant before mixing the light-emitting nanocrystalline particles and the light-scattering particles, the light-scattering particles can be dispersed more sufficiently. Therefore, excellent ejection stability and excellent external quantum efficiency can be obtained more easily.

The method for producing an ink composition may further include, before the second step, a step of preparing a dispersion of luminescent nanocrystalline particles containing luminescent nanocrystalline particles and a photopolymerizable compound. In this case, in the second step, a dispersion of light-scattering particles and a dispersion of luminescent nanocrystalline particles are mixed.
In the step of preparing a dispersion of luminescent nanocrystalline particles, the dispersion of luminescent nanocrystalline particles may be prepared by mixing luminescent nanocrystalline particles and a photopolymerizable compound and performing dispersion treatment.
As luminescent nanocrystalline particles, luminescent nanocrystalline particles having organic ligands on their surfaces may be used. That is, the dispersion of luminescent nanocrystalline particles may further comprise an organic ligand.

Mixing and dispersing treatments can be performed using, for example, dispersing devices such as bead mills, paint conditioners, planetary stirrers, jet mills, and the like. It is preferable to use a bead mill, a paint conditioner, or a jet mill from the viewpoint of improving the dispersibility of the luminescent nanocrystalline particles and facilitating adjustment of the average particle size of the luminescent nanocrystalline particles to a desired range.
According to such a method, the luminescent nanocrystalline particles can be sufficiently dispersed. Therefore, it is possible to improve the optical properties (for example, external quantum efficiency) of the pixel portion, and to easily obtain an ink composition having excellent ejection stability.

In the above production method, the hindered amine compound may be mixed in the first step or the second step. That is, the first step may be a step of preparing a dispersion of light-scattering particles containing light-scattering particles and a hindered amine compound, and optionally a polymer dispersant and a photopolymerizable compound. The second step may be a step of mixing the dispersion of light-scattering particles, the luminescent nanocrystalline particles, the hindered amine compound, and, if necessary, the photopolymerizable compound.
The hindered amine compound may be mixed with the dispersion of luminescent nanocrystalline particles prepared before the second step.

In the above production method, when other components such as antioxidants and organic solvents are used, these components may be mixed with the dispersion of the luminescent nanocrystalline particles or the dispersion of the light-scattering particles. Alternatively, it may be mixed in a mixed dispersion obtained by mixing a dispersion of luminescent nanocrystalline particles and a dispersion of light-scattering particles.

<Ink composition set>
An ink composition set of one embodiment includes the ink composition of the embodiment described above. The ink composition set may include an ink composition containing no luminescent nanocrystal particles (non-luminescent ink composition) in addition to the ink composition (luminescent ink composition) of the embodiment described above. .
A non-luminescent ink composition is, for example, a curable ink composition. The non-luminescent ink composition can have the same composition as the ink composition (luminescent ink composition) of the embodiment described above, except that it does not contain luminescent nanocrystalline particles.

A non-luminescent ink composition does not contain luminescent nanocrystalline particles. Therefore, when light is incident on a pixel portion formed of a non-luminous ink composition (a pixel portion containing a cured product of the non-luminous ink composition), the light emitted from the pixel portion is almost the same as the incident light. have the same wavelength.
Therefore, the non-luminous ink composition is preferably used to form a pixel portion having the same color as the light from the light source. For example, if the light from the light source has a wavelength in the range of 420 to 480 nm (blue light), the pixel portion formed with the non-luminous ink composition can be a blue pixel portion.

The non-luminescent ink composition preferably contains light-scattering particles. When the non-luminous ink composition contains light-scattering particles, incident light can be scattered in the pixel portions formed by the non-luminous ink composition. Thereby, the light intensity difference in the viewing angle of the light emitted from the pixel portion can be reduced.

<Light conversion layer and color filter>
Next, the details of the light conversion layer and the color filter obtained by using the ink composition set of the embodiment described above will be described with reference to the drawings. In the following description, the same reference numerals are used for the same or corresponding elements, and overlapping descriptions are omitted.
FIG. 1 is a schematic cross-sectional view of a color filter according to one embodiment of the invention. Hereinafter, for convenience of explanation, the upper side in FIG. 1 will also be referred to as "upper" or "upper", and the lower side will also be referred to as "lower" or "lower".
A color filter 100 shown in FIG. 1 has a substrate 40 and a light conversion layer 30 provided on the substrate 40 . The light conversion layer 30 includes a plurality of pixel portions 10 and a light shielding portion 20 .

The light conversion layer 30 has, as the pixel portions 10, a first pixel portion 10a, a second pixel portion 10b, and a third pixel portion 10c. The first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c are arranged in a lattice so as to repeat this order.
The light shielding portion 20 is provided between the adjacent pixel portions 10, that is, between the first pixel portion 10a and the second pixel portion 10b, between the second pixel portion 10b and the third pixel portion 10c, and between the third pixel portion. 10c and the first pixel portion 10a. In other words, adjacent pixel portions 10 are separated from each other by the light blocking portion 20 .

The first pixel portion 10a and the second pixel portion 10b are luminescent pixel portions (luminescent pixel portions) each containing a cured product of the ink composition described above. The cured product contains luminescent nanocrystalline particles, a curing component, and light scattering particles.
As shown in FIG. 1, the first pixel portion 10a includes a first curing component 13a, and first luminescent nanocrystalline particles 11a and first light scattering particles 12a dispersed in the first curing component 13a. . Similarly, the second pixel portion 10b includes a second curing component 13b and second luminescent nanocrystalline particles 11b and second light scattering particles 12b dispersed in the second curing component 13b.

The cured component is a component obtained by polymerization of a photopolymerizable compound, and contains a polymer of the photopolymerizable compound and a hindered amine compound.
The curing component may include organic components (organic ligands, polymer dispersants, unreacted photopolymerizable compounds, etc.) in the ink composition in addition to the above polymers.
In the first pixel portion 10a and the second pixel portion 10b, the first curing component 13a and the second curing component 13b may be the same or different. Moreover, the first light-scattering particles 12a and the second light-scattering particles 12b may be the same or different.

The first luminescent nanocrystalline particles 11a are red luminescent nanocrystalline particles that absorb light in the wavelength range of 420 to 480 nm and emit light having an emission peak in the wavelength range of 605 to 665 nm. That is, the first pixel section 10a can be said to be a red pixel section for converting blue light into red light.
The second luminescent nanocrystalline particles 11b are green luminescent nanocrystalline particles that absorb light in the wavelength range of 420 to 480 nm and emit light having an emission peak in the wavelength range of 500 to 560 nm. That is, the second pixel section 10b can be said to be a green pixel section for converting blue light into green light.

The content of the luminescent nanocrystalline particles in the luminescent pixel portion is based on the total mass of the cured luminescent ink composition, from the viewpoint of obtaining excellent luminescence intensity and excellent effect of improving the external quantum efficiency, It is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, particularly preferably 20% by mass or more, and 30% by mass or more. is most preferred.
The content of the luminescent nanocrystalline particles is 80% by mass or less based on the total mass of the cured luminescent ink composition, from the viewpoint of obtaining excellent reliability of the pixel portion and excellent emission intensity. is preferably 75% by mass or less, more preferably 70% by mass or less, and particularly preferably 60% by mass or less.

The content of the light-scattering particles in the light-emitting pixel portion is preferably 0.1% by mass or more based on the total weight of the cured product of the light-emitting ink composition, from the viewpoint of improving the external quantum efficiency. It is preferably 1% by mass or more, more preferably 3% by mass or more.
The content of the light-scattering particles is 60% by mass or less based on the total mass of the cured luminescent ink composition, from the viewpoint of improving the external quantum efficiency and the reliability of the pixel portion. is preferably 50% by mass or less, more preferably 40% by mass or less, 30% by mass or less, or 25% by mass or less, particularly preferably 20% by mass or less, and 15 % or less is most preferable.

The third pixel portion 10c is a non-luminous pixel portion (non-luminous pixel portion) containing a cured product of the non-luminous ink composition described above. The cured product does not contain luminescent nanocrystalline particles, but contains light-scattering particles and a curing component.
As shown in FIG. 1, the third pixel portion 10c includes a third curing component 13c and third light scattering particles 12c dispersed in the third curing component 13c.
The third curing component 13c is, for example, a component obtained by polymerization of a photopolymerizable compound, and includes a polymer of the photopolymerizable compound.
The third light scattering particles 12c may be the same as or different from the first light scattering particles 12a and the second light scattering particles 12b.

The third pixel portion 10c preferably has a transmittance of 30% or more for light with a wavelength of 420 to 480 nm, for example. In this case, the third pixel section 10c can function as a blue pixel section by using a light source that emits light in the wavelength range of 420 to 480 nm.
The transmittance of the third pixel section 10c can be measured with a microscopic spectrometer.

The content of the light-scattering particles in the third pixel portion (non-luminous pixel portion) 10c is based on the total weight of the cured non-luminous ink composition, from the viewpoint of further reducing the difference in light intensity at the viewing angle. , preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more.
From the viewpoint of further reducing light reflection, the content of the light-scattering particles is preferably 80% by mass or less, and 75% by mass or less, based on the total mass of the cured non-luminescent ink composition. is more preferably 70% by mass or less.

The thickness of the pixel portion (the first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c) is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more. preferable.
The thickness of the pixel portion (the first pixel portion 10a, the second pixel portion 10b, and the second pixel portion 10c) is preferably 30 μm or less, more preferably 20 μm or less, and further preferably 15 μm or less. preferable.

The light shielding portion 20 is a partition portion (black matrix) provided for the purpose of separating adjacent pixel portions to prevent color mixture (crosstalk) and for the purpose of preventing leakage of light from the light source.
The constituent material of the light shielding portion 20 is not particularly limited, but in addition to a metal such as chromium, a resin composition containing a binder resin and light shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments. are mentioned.
Binder resins include, for example, polyimide resins, acrylic resins, epoxy resins, polyacrylamides, polyvinyl alcohols, gelatin, casein, resins containing two or more of cellulose, photosensitive resins, O/W emulsion resins (e.g. , reactive silicone emulsion) and the like can be used.
The thickness of the light shielding portion 20 is preferably 1 to 30 μm.

The base material 40 is a transparent base material having optical transparency. For the substrate 40, for example, a transparent glass substrate made of quartz glass, Pyrex (registered trademark) glass, synthetic quartz, etc., a transparent resin film, a transparent flexible substrate such as an optical resin film, or the like is used. be able to. Above all, it is preferable to use a glass substrate made of alkali-free glass that does not contain an alkali component in the glass as the substrate 40 .
Specific examples of alkali-free glass include "7059 glass", "1737 glass", "Eagle 200" and "Eagle XG" manufactured by Corning, "AN100" manufactured by AGC, and "OA-10G" and "OA-11". These materials have a small coefficient of thermal expansion and are excellent in dimensional stability and workability in high-temperature heat treatment.

The color filter 100 including the light conversion layer 30 described above can be suitably used in combination with a light source that emits light in the wavelength range of 420-480 nm.

For example, the color filter 100 is formed by forming the light shielding portions 20 in a pattern on the substrate 40 and then forming the pixel portions 10 in the pixel portion forming regions partitioned by the light shielding portions 20 on the substrate 40. can be manufactured.
The pixel portion 10 is formed by a step of selectively applying an ink composition (inkjet ink) to a pixel portion forming region on the substrate 40 by an inkjet method, and applying an active energy ray (for example, ultraviolet rays) to the ink composition. irradiating and curing the ink composition.
A luminescent pixel portion can be obtained by using the luminescent ink composition described above as the ink composition, and a non-luminescent pixel portion can be obtained by using a non-luminescent ink composition.

The light-shielding portion 20 can be formed in a region that serves as a boundary between a plurality of pixel portions on one surface of the substrate 40 by patterning a thin film of a metal such as chromium or a thin film of a resin composition containing light-shielding particles. can.
A metal thin film can be formed by, for example, a sputtering method, a vacuum deposition method, or the like. A thin film of a resin composition containing light-shielding particles can be formed by, for example, a method such as coating or printing.
As a method for patterning, a photolithography method or the like can be used.

Examples of the ink jet method include a bubble jet (registered trademark) method using an electrothermal transducer as an energy generating element, and a piezo jet method using a piezoelectric element.
When the ink composition contains an organic solvent, it is preferable to remove at least part of the organic solvent, more preferably all of the organic solvent is removed during drying.
The method for drying the ink composition is preferably drying under reduced pressure (reduced pressure drying). From the viewpoint of controlling the composition of the ink composition, the drying under reduced pressure is usually carried out under a pressure of 1.0 to 500 Pa at 20 to 30° C. for 3 to 30 minutes.

Curing of the ink composition can be performed using, for example, a mercury lamp, a metal halide lamp, a xenon lamp, an LED, or the like.
The wavelength of light for irradiation is preferably 200 to 440 nm, and the exposure dose is preferably 10 to 4000 mJ/cm ² .
Although one embodiment of the light conversion layer, the color filter, and the manufacturing method thereof has been described above, the present invention is not limited to these.

For example, the light conversion layer may include a pixel portion (blue pixel portion) containing a cured luminescent ink composition containing blue luminescent nanocrystalline particles instead of or in addition to the third pixel portion 10c. good.
In addition, the light conversion layer includes a pixel portion (for example, a yellow pixel portion) containing a cured product of a luminescent ink composition containing luminescent nanocrystalline particles that emit light of a color other than red, green, and blue. may be In this case, each of the luminescent nanocrystalline particles contained in each pixel portion of the light conversion layer preferably has a maximum absorption wavelength within the same wavelength range.

Moreover, at least part of the pixel portion 10 of the light conversion layer 30 may include a cured product of a composition containing a pigment other than the luminescent nanocrystalline particles.
Further, the color filter 100 may include an ink-repellent layer made of an ink-repellent material having a narrower width than the light-shielding portion 20 on the light-shielding portion 20 .
Furthermore, instead of providing an ink-repellent layer, a photocatalyst-containing layer as a variable wettability layer is formed in a solid manner in a region including a pixel portion formation region, and then light is applied to the photocatalyst-containing layer through a photomask. By irradiating and exposing, the ink affinity (wettability) of the formation region of the pixel portion may be selectively increased. Examples of photocatalysts include titanium oxide and zinc oxide.

The color filter 100 may have an ink-receiving layer containing hydroxypropylcellulose, polyvinyl alcohol, gelatin or the like between the substrate and the 40-pixel portion 10 .
Also, the color filter may have a protective layer on the pixel section 10 . This protective layer is provided to planarize the color filter and prevent components contained in the pixel section 10 and components contained in the photocatalyst-containing layer from eluting into other layers.
As a constituent material of the protective layer, the material used as the protective layer of the color filter 100 can be used.

Further, in manufacturing the light conversion layer 30 and the color filter 100, the pixel portion may be formed by the photolithography method instead of the inkjet method.
In this case, first, the ink composition is applied in layers on the substrate 40 to form an ink composition layer. Next, after the ink composition layer is exposed in a predetermined pattern, it is developed using a developer. As a result, the pixel portion 10 made of the cured ink composition is formed.
Since the developer is usually alkaline, an alkali-soluble material is used as the material for the ink composition. However, the inkjet method is superior to the photolithography method from the viewpoint of efficiency of material usage. This is because the photolithographic method, in principle, removes approximately two-thirds or more of the material, which wastes the material. Therefore, in the present embodiment, it is preferable to use the ink composition as an inkjet ink and form the pixel portion by an inkjet method.

Further, the pixel portion 10 of the light conversion layer 30 of the present embodiment may further contain a pigment having substantially the same color as the luminescent color of the luminescent nanocrystalline particles, in addition to the luminescent nanocrystalline particles described above. In order to include the pigment in the pixel portion 10, the pigment may be mixed with the ink composition.

In addition, one or two of the red light-emitting pixel portion (R), the green light-emitting pixel portion (G), and the blue light-emitting pixel portion (B) in the light conversion layer 30 of the present embodiment The portion may be a pixel portion that does not contain luminescent nanocrystalline particles and contains a coloring material.
Here, usable coloring materials include, for example, a diketopyrrolopyrrole pigment and/or an anionic red organic dye for the red light-emitting pixel portion (R). At least one selected from the group consisting of a halogenated copper phthalocyanine pigment, a phthalocyanine green dye, a mixture of a phthalocyanine blue dye and an azo yellow organic dye is used in the green light emitting pixel portion (G). The blue light-emitting pixel portion (B) includes an ε-type copper phthalocyanine pigment and/or a cationic blue organic dye.
The amount of these colorants used is 1 to 5 masses based on the total mass of the pixel portion (cured product of the ink composition) 10 from the viewpoint of preventing a decrease in transmittance when mixed in the light conversion layer 30. %.

The ink composition of the invention is also suitable for light conversion films. Examples of methods for carrying the ink composition of the present invention on a substrate include spin coating, die coating, extrusion coating, roll coating, wire bar coating, gravure coating, spray coating, and dipping. Further, an organic solvent may be added to the ink composition during coating. Examples of organic solvents include hydrocarbon solvents, halogenated hydrocarbon solvents, ether solvents, alcohol solvents, ketone solvents, ester solvents, and aprotic solvents. , hydrocarbon solvents, halogenated hydrocarbon solvents, and ester solvents are preferable. Specific examples of organic solvents include toluene, hexane, heptane, cyclohexane, and methylcyclohexane. These may be used alone or in combination, and may be appropriately selected in consideration of the vapor pressure and the solubility of the luminescent particle-containing composition. As a method for volatilizing the added organic solvent, natural drying, drying by heating, drying under reduced pressure, and drying by heating under reduced pressure can be used. The thickness of the film may be appropriately adjusted depending on the application, but is preferably, for example, 0.1 μm or more and 10 mm or less, and particularly preferably 1 μm or more and 1 mm or less.

As for the shape of the substrate when the ink composition of the present invention is carried on the substrate, it may have a curved surface as a constituent part, in addition to the flat plate. The material constituting the substrate can be used regardless of whether it is an organic material or an inorganic material. Examples of organic materials for the substrate include polyethylene terephthalate, polycarbonate, polyimide, polyamide, polymethyl methacrylate, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyarylate, polysulfone, and triacetyl. Cellulose, cellulose, polyether ether ketone, etc., and inorganic materials include, for example, silicon, glass, calcite, and the like.

When the ink composition of the present invention is carried on a substrate and polymerized, it is desirable that the polymerization progresses rapidly. The temperature during irradiation is preferably within a temperature range in which the particle shape of the luminescent nanocrystalline particles is maintained. When a film is to be produced by photopolymerization, it is preferable to polymerize at a temperature as close to room temperature as possible, typically at 25° C., in order to avoid unintended induction of thermal polymerization. The intensity of the active energy ray is preferably 0.1 mW/cm ² or more and 2.0 W/cm ² or less. If the intensity is less than 0.1 mW/ ^cm2 , a long time is required to complete the photopolymerization, resulting in poor productivity. There is a risk that the ink composition will deteriorate.

The light conversion film that uses the ink composition of the present invention obtained by polymerization as a forming material can be subjected to heat treatment for the purpose of reducing initial changes in properties and stably developing properties. The heat treatment temperature is preferably in the range of 50 to 250° C., and the heat treatment time is preferably in the range of 30 seconds to 12 hours.

The light conversion film formed by the ink composition of the present invention produced by such a method may be used alone after peeling from the substrate, or may be used without peeling. Moreover, the obtained light conversion film may be laminated, or may be used by bonding to another substrate.

When the light conversion film using the ink composition of the present invention as a forming material is used in a laminated structure, the laminated structure may have arbitrary layers such as a substrate, a barrier layer, and a light scattering layer. Examples of the material constituting the substrate include those mentioned above. Examples of the structure of the laminated structure include a structure in which a light conversion film having the ink composition of the present invention as a forming material is sandwiched between two substrates. In that case, in order to protect the light conversion film formed from the ink composition from moisture and oxygen in the air, the peripheral portion between the substrates may be sealed with a sealing material. Examples of the barrier layer include polyethylene terephthalate and glass. A light scattering layer may be provided to uniformly scatter light. The light-scattering layer includes, for example, a layer containing the light-scattering particles and a light-scattering film. FIG. 2 is a cross-sectional view schematically showing the configuration of the laminated structure of this embodiment. In FIG. 2, hatching indicating a cross section is omitted in order to avoid complication of the drawing. The laminated structure 50 has a light conversion film 54 of the present embodiment sandwiched between a first substrate 51 and a second substrate 52 . The light conversion film 54 is formed using an ink composition containing light scattering particles 541 and luminescent nanocrystalline particles 542 as a forming material. distributed over The light conversion film 54 is sealed with a sealing layer 53 made of a sealing material.

A laminated structure containing a light conversion film formed from the ink composition of the present invention is suitable for light emitting device applications. Examples of the configuration of the light-emitting device include a structure having a prism sheet, a light guide plate, a laminated structure containing the light-emitting particles of the present invention, and a light source. Light sources include, for example, light emitting diodes, lasers, and electroluminescent devices.

A laminated structure containing a light conversion film formed from the ink composition of the present invention is preferably used as a wavelength conversion member for displays. As an example of the structure when used as a wavelength conversion member, for example, a laminated structure in which a light conversion film containing the luminescent particle-containing composition of the present invention as a forming material is sealed between two barrier layers is attached to a light guide plate. A structure to be installed on top is mentioned. In this case, the blue light from the light emitting diodes installed on the side surface of the light guide plate is converted into green light or red light by passing through the laminated structure, and the blue light, green light, and red light are mixed. Since white light can be obtained, it can be used as a backlight for displays.

EXAMPLES The present invention will be specifically described below with reference to Examples. However, the present invention is not limited only to the following examples.
1. Preparation of each component 1-1. Photopolymerizable Compound Photopolymerizable compounds shown in Table 1 below were prepared. Table 1 also shows the Hansen solubility parameters (δD, δP and δH) of the photopolymerizable compound.

1-2. Photopolymerization initiator Photopolymerization initiator 1: phenyl (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide Photopolymerization initiator 2: phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide 1-3 Hindered amine compound Hindered amine compound 1: decanedicarboxylic acid bis (2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester 1-4.Antioxidant Antioxidant 1: Bis (decyl) pentaerythritol diphosphite Antioxidant 2: pentaerythritol tetrakis [3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionate]

1-5. Preparation of Green Luminescent Particle 1 (InP/ZnSeS/ZnS Nanocrystalline Particles Modified with Organic Ligand)
[Preparation of indium laurate solution]
10 g of 1-octadecene (ODE), 146 mg (0.5 mmol) of indium acetate and 300 mg (1.5 mmol) of lauric acid were added to the reaction flask to obtain a mixture. A clear solution (indium laurate solution) was obtained by heating the mixture at 140° C. for 2 hours under vacuum.
This solution was kept in the glove box at room temperature until needed. Since indium laurate has low solubility at room temperature and tends to precipitate, when using an indium laurate solution, the precipitated indium laurate in this solution (ODE mixture) is heated to about 90° C. to obtain a transparent solution. After forming a fine solution, the desired amount was weighed out and used.

[Preparation of core (InP core) of green-emitting nanocrystalline particles]
5 g trioctylphosphine oxide (TOPO), 1.46 g (5 mmol) indium acetate and 3.16 g (15.8 mmol) lauric acid were added to the reaction flask to give a mixture. The mixture was heated at 160° C. for 40 minutes under a nitrogen (N ₂ ) environment and then at 250° C. for 20 minutes under vacuum.
The reaction temperature (temperature of the mixture) was then raised to 300° C. under a nitrogen (N ₂ ) environment. At this temperature, a mixture of 3 g of 1-octadecene (ODE) and 0.25 g (1 mmol) of tris(trimethylsilyl)phosphine was rapidly introduced into the reaction flask and the reaction temperature was maintained at 260°C.

After 5 minutes, the reaction was stopped by removing the heater and the resulting reaction solution was cooled to room temperature.
8 mL of toluene and 20 mL of ethanol were then added to the reaction solution in the glove box.
Subsequently, centrifugation was performed to precipitate InP nanocrystalline particles, and the supernatant was decanted to obtain InP nanocrystalline particles.
The resulting InP nanocrystal particles were then dispersed in hexane. As a result, a dispersion (hexane dispersion) containing 5% by mass of InP nanocrystal particles was obtained.

The hexane dispersion of the obtained InP nanocrystal particles and the indium laurate solution were charged into a reaction flask to obtain a mixture. The amounts of the hexane dispersion of InP nanocrystal particles and the indium laurate solution were adjusted to 0.5 g (25 mg of InP nanocrystal particles) and 5 g (178 mg of indium laurate), respectively.
After allowing the mixture to stand at room temperature under vacuum for 10 minutes, the inside of the flask was returned to normal pressure with nitrogen gas, the temperature of the mixture was raised to 230°C, and the temperature was maintained for 2 hours to remove hexane from the inside of the flask. .
Next, the temperature inside the flask was raised to 250°C, and a mixture of 3 g of 1-octadecene (ODE) and 0.03 g (0.125 mmol) of tris(trimethylsilyl)phosphine was rapidly introduced into the reaction flask, and the reaction temperature was raised to 230°C. maintained at

After 5 minutes, the reaction was stopped by removing the heater and the resulting reaction solution was cooled to room temperature.
8 mL of toluene and 20 mL of ethanol were then added to the reaction solution in the glovebox.
Subsequently, centrifugation is performed to precipitate the InP nanocrystalline particles (InP cores), which are the cores of the green-emitting InP/ZnSeS/ZnS nanocrystalline particles. ).
Next, the obtained InP nanocrystalline particles (InP cores) were dispersed in hexane to obtain a dispersion (hexane dispersion) containing 5% by mass of InP nanocrystalline particles (InP cores).

[Formation of green-emitting nanocrystalline particle shell (ZnSeS/ZnS shell)]
After adding 2.5 g of the hexane dispersion of the obtained InP nanocrystalline particles (InP cores) to the reaction flask, 0.7 g of oleic acid was added to the reaction flask at room temperature, and the temperature was raised to 80° C. for 2 hours. held for time.
Then, 14 mg of diethylzinc dissolved in 1 mL of ODE, 8 mg of bis(trimethylsilyl)selenide and 7 mg of hexamethyldisilathiane (ZnSeS precursor solution) are added dropwise to this reaction mixture, heated to 200° C. and held for 10 minutes. This formed a ZnSeS shell with a thickness of 0.5 monolayer.

The temperature was then raised to 140° C. and held for 30 minutes.
Next, a ZnS precursor solution obtained by dissolving 69 mg of diethyl zinc and 66 mg of hexamethyldisilathiane in 2 mL of ODE was added dropwise to this reaction mixture, and the temperature was raised to 200° C. and maintained for 30 minutes to obtain A ZnS shell with a thickness of 2 monolayers was formed.
Ten minutes after the addition of the ZnS precursor solution, the reaction was stopped by removing the heater.
The reaction mixture was then cooled to room temperature and the resulting white precipitate was removed by centrifugation to yield a transparent nanocrystalline particle dispersion (InP/ZnSeS) with green-emitting InP/ZnSeS/ZnS nanocrystalline particles dispersed therein. /ODE dispersion of ZnS nanocrystalline particles) was obtained.

[Synthesis of organic ligand]
After putting polyethylene glycol (manufactured by Sigma-Aldrich) having a number average molecular weight (Mn) of 400 into the flask, an equimolar amount of succinic anhydride (manufactured by Sigma-Aldrich) was added to the polyethylene glycol while stirring in a nitrogen gas environment. was added.
The internal temperature of the flask was raised to 80° C. and stirred for 8 hours to obtain an organic ligand represented by the following formula (A) as a pale yellow viscous oil.

[Preparation of green-emitting InP/ZnSeS/ZnS nanocrystalline particles by ligand exchange]
30 mg of the above organic ligand was added to 1 mL of ODE dispersion of InP/ZnSeS/ZnS nanocrystalline particles.
Ligand exchange was then performed by heating at 90° C. for 5 hours. Aggregation of nanocrystalline particles was observed as the ligand exchange progressed.
After completion of ligand exchange, the supernatant was decanted to obtain nanocrystalline particles.

Then, 3 mL of ethanol was added to the resulting nanocrystalline particles, and ultrasonically treated to redisperse them. 10 mL of n-hexane was added to 3 mL of the ethanol dispersion of nanocrystalline particles.
Subsequently, centrifugation was performed to precipitate the nanocrystalline particles, followed by decanting the supernatant and drying under vacuum to obtain green luminescent particles 1 (InP/ZnSeS/ZnS nanocrystalline particles modified with organic ligands). . The content of organic ligands in the total amount of nanocrystalline particles modified with organic ligands was 35% by mass.

1-6. Preparation of Green Luminescent Particle 2 (Silica-coated CsPbBr ₃ )
First, 6.0 g of cesium carbonate, 250 mL of 1-octadecene, and 25 mL of oleic acid were mixed to obtain a mixture. Next, this mixed solution was dried under reduced pressure at 120° C. for 30 minutes, and then heated at 150° C. under an argon atmosphere. This gave a cesium-oleic acid solution.

On the other hand, 5.0 g of lead (II) bromide, 375 mL of 1-octadecene, and 37.5 mL of oleic acid were mixed to obtain a mixed solution. Next, this mixed solution was dried under reduced pressure at 90° C. for 10 minutes, and then 37.5 mL of 3-aminopropyltriethoxysilane (APTES) was added to the mixed solution under an argon atmosphere. After drying under reduced pressure for another 20 minutes, it was heated at 140° C. under an argon atmosphere.

After that, 37.5 mL of the cesium-oleic acid solution was added to the mixed solution containing lead (II) bromide at 150°C, and the mixture was reacted by heating and stirring for 5 seconds, and then cooled in an ice bath. 3 L of methyl acetate was then added. After centrifuging the resulting suspension (10,000 rpm, 1 minute), the supernatant was removed, mixed with toluene, and stirred for 2 hours. Thereafter, silica-coated green light-emitting particles 2 were obtained by removing toluene. The nanocrystals constituting the luminescent particles 2 were perovskite-type lead tribromide cesium crystals, and their average particle diameter was 10 nm when analyzed by scanning transmission electron microscopy.

1-7. Preparation of green luminescent particles 3 (silica-coated FAPbBr ₃ )
In an argon atmosphere, 0.4 g of formamidine acetate and 12.5 ml of oleic acid were added to a three-necked flask. After degassing under reduced pressure with stirring at room temperature for 18 hours while reducing the pressure with a vacuum pump, the mixture was heated and stirred at 120° C. for 30 minutes. The vacuum was released in the argon atmosphere to obtain a formamidine-oleic acid solution.

Meanwhile, 1.0 g of lead bromide (II), 7.5 mL of oleic acid, and 75 mL of 1-octadecene were added to a three-necked flask under an argon atmosphere. The mixture was heated and stirred at 90° C. for 10 minutes while reducing the pressure with a vacuum pump. The vacuum was released while the argon atmosphere was maintained, and 7.5 mL of 3-aminopropyltriethoxysilane (APTES) was added. The mixture was stirred at 90° C. until a uniform solution was obtained.

After that, 11.6 mL of the formamidine-oleic acid solution was added to the mixture containing lead (II) bromide at 140°C, and the mixture was reacted by heating and stirring for 5 seconds, and then cooled in an ice bath. 3 L of methyl acetate was then added. After centrifuging the resulting suspension (10,000 rpm, 1 minute), the supernatant was removed, mixed with toluene, and stirred for 2 hours. Thereafter, silica-coated green light-emitting particles 3 were obtained by removing toluene. The nanocrystals constituting the luminescent particles 3 were perovskite-type formamidium lead bromide crystals, and the average particle diameter thereof was 10 nm when analyzed by scanning transmission electron microscope observation.

1-8. Preparation of Green Light Emitting Particle 4 (Silica Multilayer Coated FAPbBr ₃ )
4 g of a block copolymer (S2VP, manufactured by PolymerSource.) having a structure represented by the following formula (B4) was added to 400 mL of toluene and dissolved by heating at 60°C. Luminescent particles 3 were added to a toluene solution in which the block copolymer was dissolved so that the concentration of the luminescent particles 3 was 0.16% by mass, stirred for 15 minutes, centrifuged, and the supernatant was collected. , luminescent particles 3 and a block copolymer were obtained.

To 100 mL of the toluene dispersion, 5 mL of a compound represented by the following formula (C4) (MS-51, manufactured by Colcoat Co., Ltd., the average value of m in formula (C4) is 4) was added and stirred for 5 minutes. Then, 0.25 mL of ion-exchanged water was further added and stirred for 2 hours.

After centrifuging the resulting solution at 9,000 rpm for 5 minutes, 100 mL of the supernatant was recovered to obtain a toluene dispersion of luminescent particles 4 in which the luminescent particles 3 were further coated with silica. rice field. Luminescent particles 4 were obtained by removing toluene from this dispersion. The average particle size of the luminescent particles 4 was measured using a dynamic light scattering nanotrack particle size distribution meter and found to be 95 nm. In addition, when the element distribution of the luminescent particles 4 was evaluated by an energy dispersive X-ray analysis method (STEM-EDS) using a scanning transmission electron microscope, it was confirmed that the surface layer of the luminescent particles contained Si. . When the thickness of the surface layer was measured, it was about 5 nm. Further, for the luminescent particles, weight reduction was confirmed in the range of 200 to 550 ° C. by thermogravimetric differential thermal analysis (TG-DTA; temperature increase rate 10 ° C./min, under nitrogen atmosphere) measurement. was suggested to contain On the other hand, the used block copolymer was identified as a component by pyrolysis gas chromatograph mass spectrometer (TD/Py-GC/MS) measurement.

1-6. Light-scattering particle dispersion (Light-scattering particle dispersion 1)
In a container filled with argon gas, 5.23 g of titanium oxide (product name: CR-60-2, manufactured by Ishihara Sangyo Co., Ltd., average particle diameter (volume average diameter): 210 nm) and a polymer dispersant (Ajisper 0.27 g of PB-821, manufactured by Ajinomoto Fine-Techno Co., Ltd.) and 4.5 g of photopolymerizable compound 3 were mixed.
After that, zirconia beads (diameter: 1.25 mm) were added to the obtained mixture, the mixture was dispersed by shaking for 2 hours using a paint conditioner, and the zirconia beads were removed with a polyester mesh filter to remove light. A scattering particle dispersion 1 (titanium oxide content: 52.3% by mass) was obtained.

(Light-scattering particle dispersion 2)
A light-scattering particle dispersion 2 was obtained in the same manner as described above, except that the photopolymerizable compound 3 was changed to the photopolymerizable compound 5.
(Light-scattering particle dispersion 3)
A light-scattering particle dispersion 3 was obtained in the same manner as described above, except that the photopolymerizable compound 3 was changed to the photopolymerizable compound 4.

(Light-scattering particle dispersion 4)
A light-scattering particle dispersion 4 was obtained in the same manner as described above, except that the photopolymerizable compound 3 was changed to the photopolymerizable compound 6.
(Light-scattering particle dispersion 5)
A light-scattering particle dispersion 5 was obtained in the same manner as described above, except that the photopolymerizable compound 3 was changed to the photopolymerizable compound 9.

2. Preparation of green ink composition (Example 1)
Green light-emitting particles 1, light-scattering particle dispersion 1, photopolymerizable compound 3, photopolymerization initiator 1, photopolymerization initiator 2, and hindered amine compound 1, and the content of each component is shown in Table 2. (unit: parts by mass), and uniformly mixed in a container filled with argon gas.
After that, the mixture was filtered through a filter with a pore size of 5 μm in a glove box.
Furthermore, argon gas was introduced into the container containing the obtained filtrate, and the inside of the container was saturated with argon gas.
Next, the green ink composition 1 of Example 1 was obtained by removing the argon gas under reduced pressure.

(Example 2)
In the same manner as in Example 1, except that the photopolymerizable compound 5 was used instead of the photopolymerizable compound 3, and the light-scattering particle dispersion 2 was used instead of the light-scattering particle dispersion 1. A green ink composition 2 was obtained.
(Example 3)
Further, a green ink composition 3 was obtained in the same manner as in Example 2, except that Antioxidant 1 and Antioxidant 2 were used in the amounts shown in Table 2.

(Example 4)
Photopolymerizable compound 6 and photopolymerizable compound 4 were used in the amounts shown in Table 2 in place of photopolymerizable compound 5, and light-scattering particle dispersion 3 was used in place of light-scattering particle dispersion 2. A green ink composition 4 was obtained in the same manner as in Example 2, except that it was used.
(Example 5)
Photopolymerizable compound 6, photopolymerizable compound 4, and photopolymerizable compound 9 are used in the amounts shown in Table 2 in place of photopolymerizable compound 5, and light scattering particles are used in place of light scattering particle dispersion 2. A green ink composition 5 was obtained in the same manner as in Example 3, except that the organic particle dispersion 3 was used.

(Example 6)
Photopolymerizable compound 6, photopolymerizable compound 3, photopolymerizable compound 1, and photopolymerizable compound 4 were used in the amounts shown in Table 2 in place of photopolymerizable compound 5, and light-scattering particle dispersion 2 A green ink composition 6 was obtained in the same manner as in Example 3, except that the light-scattering particle dispersion 1 was used instead of .

(Comparative example 1)
A green ink composition C1 was obtained in the same manner as in Example 1, except that the hindered amine compound 1 was omitted and the contents of the respective components were blended so as to be the amounts shown in Table 3.

(Comparative example 2)
In the same manner as in Example 1, except that the photopolymerizable compound 6 was used instead of the photopolymerizable compound 3, and the light-scattering particle dispersion 4 was used instead of the light-scattering particle dispersion 1. A green ink composition C2 was obtained.

(Comparative Example 3)
Photopolymerizable compound 9 and photopolymerizable compound 10 were used in the amounts shown in Table 3 in place of photopolymerizable compound 3, and light-scattering particle dispersion 5 was used in place of light-scattering particle dispersion 1. A green ink composition C3 was obtained in the same manner as in Example 1, except that it was used.

(Example 7)
green luminescent particles 2, light scattering particle dispersion 1, photopolymerizable compound 5, photopolymerizable compound 12, photopolymerization initiator 1, photopolymerization initiator 2, and hindered amine compound 1, The components were blended so that the amounts (unit: parts by mass) shown in Table 4 were obtained, and mixed uniformly in a vessel filled with argon gas.
After that, the mixture was filtered through a filter with a pore size of 5 μm in a glove box.
Furthermore, argon gas was introduced into the container containing the obtained filtrate, and the inside of the container was saturated with argon gas.
Next, the green ink composition 7 of Example 7 was obtained by removing the argon gas under reduced pressure.

(Example 8)
A green ink composition 8 was obtained in the same manner as in Example 7, except that the green luminescent particles 3 were used instead of the green luminescent particles 2.

(Example 9)
A green ink composition 9 was obtained in the same manner as in Example 7, except that the green luminescent particles 4 were used instead of the green luminescent particles 2.

(Comparative Example 4)
A green ink composition C4 was obtained in the same manner as in Example 7, except that the hindered amine compound 1 was omitted and the contents of the respective components were blended so as to be the amounts shown in Table 4.

(Example 10)
Green luminescent particles 2, light scattering particle dispersion 1, photopolymerizable compound 5, photopolymerizable compound 11, photopolymerizable compound 12, photopolymerization initiator 1, photopolymerization initiator 2, hindered amine System compound 1 was blended so that the content of each component was the amount (unit: parts by mass) shown in Table 5, and mixed uniformly in a vessel filled with argon gas.
After that, the mixture was filtered through a filter with a pore size of 5 μm in a glove box.
Furthermore, argon gas was introduced into the container containing the obtained filtrate, and the inside of the container was saturated with argon gas.
Next, the green ink composition 10 of Example 7 was obtained by removing the argon gas under reduced pressure.

(Example 11)
A green ink composition 11 was obtained in the same manner as in Example 10, except that the green light-emitting particles 3 were used instead of the green light-emitting particles 2.

(Example 12)
A green ink composition 12 was obtained in the same manner as in Example 10, except that the green luminescent particles 4 were used instead of the green luminescent particles 2.

(Comparative Example 5)
A green ink composition C5 was obtained in the same manner as in Example 10, except that the use of the hindered amine compound 1 was omitted and the contents of each component were blended so as to be the amounts shown in Table 5.

3. Evaluation 3-1. Evaluation of external quantum efficiency (EQE) [Preparation of sample for evaluation of external quantum efficiency]
The ink compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 4 were applied to a glass substrate in the air by a spin coater so as to give a film thickness of 10 μm.
The coating film was cured by irradiating UV light in a nitrogen atmosphere with a UV irradiation device using an LED lamp having a dominant wavelength of 395 nm so that the integrated light amount was 1500 mJ/cm ² .
As a result, a layer (light conversion layer) composed of a cured product of the ink composition was formed on the glass substrate to obtain an evaluation sample.

[Measurement of EQE]
A blue LED (manufactured by CCS Co., Ltd.) that emits light having an emission peak at a wavelength of 450 nm was used as a surface emitting light source.
As a measuring device, an integrating sphere was connected to a radiation spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "MCPD-9800"), and the integrating sphere was placed above the blue LED.
The produced evaluation sample was inserted between the blue LED and the integrating sphere, and the spectrum observed by lighting the blue LED and the illuminance at each wavelength were measured.

The external quantum efficiency was determined as follows from the spectrum and illuminance measured by the above measuring device.
The external quantum efficiency is a value indicating how much of the light (photons) incident on the light conversion layer is emitted to the observer side as fluorescence.
Therefore, if this value is large, it indicates that the light conversion layer is excellent in light emission characteristics, which is an important evaluation index.
EQE (%) = P1 (Green)/E (Blue) x 100

Here, E (Blue) and P1 (Green) each represent the following values.
E (Blue) represents the total value of “illuminance×wavelength/hc” in the wavelength range of 380 to 490 nm.
P1 (Green) represents the total value of “illuminance×wavelength/hc” in the wavelength range of 500 to 650 nm.
These values correspond to the number of photons observed. In addition, h represents Planck's constant and c represents the speed of light.

3-2. Evaluation of deterioration behavior of luminescent nanocrystalline particles (EQE retention rate)
Each evaluation sample was irradiated with white light for 1 hour in the atmosphere. After that, the external quantum efficiency (EQE) was evaluated in the same manner as in 3-1.
Then, the maintenance rate (%) of the EQE after irradiation with respect to the EQE before irradiation with white light was determined, and the degradation behavior of the luminescent nanocrystalline particles was evaluated according to the following criteria.
[Evaluation criteria]
◎: 95% or more ○: 90% or more and less than 95% △: 80% or more and less than 90% ×: less than 80% These results are also shown in Table 2 and Table 4.

As shown in Examples 1 to 6, the light conversion layers using the ink compositions 1 to 6 of the present invention are compared to the light conversion layers using the ink compositions C1 to C3 of Comparative Examples 1 to 3. Therefore, it can be seen that the EQE maintenance rate is good. It is believed that this is because the hindered amine compound acts effectively in the ink composition containing the photopolymerizable compound having the Hansen solubility parameter within the specific range. Further, as shown in Examples 3, 5 and 6, the light conversion layers using the ink compositions 3, 5 and 6 of the present invention are formed from ink compositions further containing an antioxidant and are very excellent. It can be seen that the EQE maintenance rate is

As shown in Examples 7 to 9, the light conversion layer using ink compositions 7 to 9 of the present invention had better EQE than the light conversion layer using ink composition C4 of Comparative Example 4. It can be seen that the retention rate is good. In particular, the light conversion layer of Example 7 has a better EQE retention rate than the light conversion layer of Comparative Example 4. Therefore, even in the durability imparting particles coated with silica, the durability is improved by the hindered amine compound. I know you do. Moreover, when Examples 7 to 9 are compared, it can be seen that the light conversion layer using ink composition 9 containing green light-emitting particles 4 is particularly excellent.

4-1. Evaluation of Light Conversion Film The ink compositions obtained in Examples 10 to 12 and Comparative Example 5 were coated on a glass substrate to a thickness of 100 μm, and another glass substrate was attached. rice field. This coated glass was cured by irradiating UV light in a nitrogen atmosphere with a UV irradiation device using an LED lamp having a main wavelength of 395 nm so that the cumulative light amount was 1 J/cm ² to obtain a light conversion film.

As shown in Examples 10 to 12, the light conversion films using the ink compositions 10 to 12 of the present invention had a higher EQE retention rate than the light conversion film using the ink composition C5 of Comparative Example 5. is good. In particular, the light conversion film of Example 10 has a better EQE retention ratio than the light conversion film of Comparative Example 5, so even in the durability imparting particles coated with silica, the durability is improved by the hindered amine compound. I know you do.

From the above results, it is clear that the light conversion layer and the light conversion film obtained by the ink composition of the present invention have high stability against light and heat.

10 pixel section 10a first pixel section 10b second pixel section 10c third pixel section 11a first luminescent nanocrystalline particles 11b second luminescent nanocrystalline particles 12a first light scattering particles 12b second light scattering particles 12c third 3 Light scattering particles 20 Light shielding part 30 Light conversion layer 40 Base material 100 Color filter 50 Laminated structure 51 First substrate 52 Second substrate 53 Sealing layer 54 Light conversion film 541 Light scattering particles 542 Light emitting particles

Claims

luminescent nanocrystalline particles;
a photopolymerizable component;
containing a hindered amine compound,
The photopolymerizable component has at least one Hansen Solubility Parameter (HSP) δD of 16 to 17.5 MPa 0.5 , δP of 2.5 to 5 MPa 0.5 and δH of 3 to 6 MPa 0.5 An ink composition comprising: a photopolymerizable compound of the type:
The ink composition according to claim 1, wherein the photopolymerizable compound is a monofunctional or polyfunctional (meth)acrylate.
3. The ink composition according to claim 2, wherein the photopolymerizable compound is a bifunctional (meth)acrylate represented by the following formula (1).

[In formula (1), R 1 represents an alkylene group having 4 to 8 carbon atoms, and two R 2 independently represent a hydrogen atom or a methyl group. ]
The ink composition according to claim 1 or 2, wherein the proportion of the photopolymerizable compound in the photopolymerizable component is 30% by mass or more.
3. The ink composition according to claim 1, wherein the hindered amine compound has a partial structure represented by the following formula (2).

[In formula (2), R 3 represents a hydrogen atom or a substituent, R 4 represents a linking group, and * represents a bond. ]
6. The ink composition according to claim 5, wherein R3 in formula ( 2 ) is an alkoxy group.
The ink composition according to claim 1 or claim 2, further comprising an antioxidant.
The ink composition according to claim 1 or 2, which is used in a droplet ejection method by an inkjet system.
A plurality of pixel units and a light shielding unit provided between the adjacent pixel units,
3. A light conversion layer, wherein the plurality of pixel portions have luminescent pixel portions containing a cured product of the ink composition according to claim 1 or 2.
The plurality of luminescent pixel units are
A first luminescent pixel containing, as the luminescent nanocrystalline particles, first luminescent nanocrystalline particles that absorb light in a wavelength range of 420 to 480 nm and emit light having an emission peak in a wavelength range of 605 to 665 nm. Department and
A second luminescent pixel containing, as the luminescent nanocrystalline particles, second luminescent nanocrystalline particles that absorb light in a wavelength range of 420 to 480 nm and emit light having an emission peak in a wavelength range of 500 to 560 nm. 10. The light conversion layer of claim 9, comprising:
The light conversion layer according to claim 9, wherein the plurality of pixel portions further have non-luminous pixel portions containing light scattering particles.
A color filter comprising the light conversion layer according to claim 9.
A light conversion film comprising a cured product of the ink composition according to claim 1 or claim 2.