TW202140693A - Ink composition for photoconversion layer formation, photoconversion layer, and color filter - Google Patents

Abstract

The present invention provides a demand for an ink composition capable of forming a photoconversion layer having exceptional external quantum efficiency. This ink composition is an ink composition for photoconversion layer formation, the ink composition containing luminescent nanocrystal particles, a photopolymerizable compound, and a hypophosphorous acid diester compound.

Description

Ink composition, light conversion layer and color filter for forming light conversion layer

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

Conventionally, the color filter pixel portion of a display such as a liquid crystal display device uses, for example, a curable resist material containing red organic pigment particles or green organic pigment particles, and alkali-soluble resin and/or acrylic monomers. Manufactured by photolithography method.

In recent years, there has been a strong demand for lower power consumption of displays, and therefore active research is underway to replace the red organic pigment particles or green organic pigment particles, and use, for example, quantum dots, quantum rods, other inorganic phosphor particles, etc. Nano crystal grains are used to form color filter pixels such as red pixels and green pixels.

However, in the manufacturing method of the color filter using the photolithography method, due to the characteristics of the manufacturing method, there is a waste of resist other than the pixel portion including the relatively expensive luminescent nano crystal grains. Disadvantages of agent materials. Under such circumstances, in order to avoid the waste of the above-mentioned resist material, research has begun to form the pixel portion of the light conversion substrate by the inkjet method (Patent Document 1). [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2008/001693

[The problem to be solved by the invention] For the color filter pixel portion (hereinafter also referred to as the "pixel portion") constituting the light conversion layer of the color filter, from the viewpoint of low power consumption, it is required to further improve the external quantum efficiency (External Quantum Efficiency). , EQE).

Therefore, one of the objects of the present invention is to provide an ink composition that can form a light conversion layer with excellent external quantum efficiency. [Means to solve the problem]

The results of research by the inventors have shown that when phosphorous antioxidants such as phosphite triester are used in an ink composition containing luminescent nanocrystals, the function as an antioxidant can inhibit the luminescent nanocrystals. There is a possibility that the external quantum efficiency may be improved due to the deterioration of the anti-oxidant. On the other hand, phosphorous acid is generated due to the hydrolysis of the antioxidant, and the phosphorous acid may also hinder the function of the luminescent nanocrystal grains. The inventors of the present invention conducted further studies in view of the above-mentioned research results. As a result, they found that by using a hypophosphorous acid diester compound, a pixel portion having an excellent external quantum efficiency can be obtained compared with the prior art, thereby completing the present invention. invention.

One aspect of the present invention relates to an ink composition, which is an ink composition for forming a light conversion layer and contains luminescent nanocrystal particles, a photopolymerizable compound, and a hypophosphorous acid diester compound.

According to the ink composition of the above aspect, the external quantum efficiency of the pixel portion can be improved. Although the reason for obtaining this effect is not clear, it is presumed that this is because the hypophosphorous acid diester compound has a function as an antioxidant, is not easily hydrolyzed, and is not liable to hinder the function of the luminescent nanocrystal particles due to the generation of phosphoric acid.

The hypophosphorous acid diester compound is preferably a compound represented by the following formula (II), and more preferably a compound represented by the following formula (IV).

[式（II）中，X¹ 表示氧原子或硫原子，R¹ 表示氫原子或有機基（其中，與P直接鍵結的原子為碳原子），Ar¹ 表示芳基，兩個X¹ 彼此可相同亦可不同，兩個Ar¹ 彼此可相同亦可不同]。[化1]

[In the formula (II), X ¹ represents an oxygen atom or a sulfur atom, R ¹ represents a hydrogen atom or an organic group (wherein, the atom directly bonded to P is a carbon atom), Ar ¹ represents an aryl group, and two X ¹ are each other They may be the same or different, and the two Ar ¹ may be the same or different from each other].

[式（IV）中，Y表示連結基，X² 及X³ 表示氧原子或硫原子，Ar² 及Ar³ 表示芳基，兩個X² 彼此可相同亦可不同，兩個X³ 彼此可相同亦可不同，兩個Ar² 彼此可相同亦可不同，兩個Ar³ 彼此可相同亦可不同]。[化2]

[In formula (IV), Y represents a linking group, X ² and X ³ represent an oxygen atom or a sulfur atom, Ar ² and Ar ³ represent an aryl group, two X ² may be the same or different from ^{each other, and two X 3} may each other The same or different, the two Ar ² may be the same or different from ^{each other, and the two Ar 3} may be the same or different from each other].

Based on the total mass of the ink composition, the content of the luminescent nanocrystal grains is preferably 20% by mass or more.

Based on the total mass of the ink composition, the content of the hypophosphorous acid diester compound is preferably 0.01% by mass to 10% by mass.

The photopolymerizable compound preferably includes a radical polymerizable compound having a cyclic structure and a radical polymerizable compound having a linear structure having 4 or more carbon atoms.

The ink composition of the above aspect preferably further contains a phenolic antioxidant. The phenol-based antioxidant is preferably a hindered phenol-based antioxidant.

The ink composition of the aforementioned aspect preferably further contains light-scattering particles. In this case, the ink composition preferably further contains a polymer dispersant.

The ink composition is preferably used in an inkjet method. That is, the ink composition is preferably an inkjet ink.

Another aspect of the present invention relates to a light conversion layer, which includes a plurality of pixel portions and a light shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions includes the ink composition containing the aspect The luminous pixel part of the hardened object.

The light conversion layer of the above aspect may include a first light-emitting pixel portion and a second light-emitting pixel portion as a light-emitting pixel portion, the first light-emitting pixel portion having an absorption in the range of 420 nm to 480 nm The second luminescent pixel portion contains light having a wavelength in the range of 420 nm to 480 nm, and emits light having a peak wavelength of light in the range of 605 nm to 665 nm. On the other hand, luminescent nanocrystal particles that emit light with a luminous peak wavelength in the range of 500 nm to 560 nm.

The light conversion layer of the above aspect may further include a non-luminescent pixel portion including light-scattering particles.

Another aspect of the present invention relates to a color filter including the light conversion layer of the above aspect. [Effects of the invention]

According to the present invention, it is possible to provide an ink composition capable of forming a light conversion layer having excellent external quantum efficiency.

Hereinafter, embodiments of the present invention will be described in detail. In addition, in this specification, the numerical range represented by "~" means the range including the numerical value described before and after "~" as the minimum value and the maximum value, respectively. In addition, the "cured material of the ink composition" in this specification refers to curing the curable component in the ink composition (when the ink composition contains a solvent, the ink composition after drying) (for example, photopolymerization). Sexual compound polymerization). The cured product of the ink composition after drying may not contain a solvent. As long as there is no special description, the materials exemplified in this specification can be used alone or in combination of two or more.

＜Ink composition＞ The ink composition of one embodiment includes luminescent nanocrystal grains, a photopolymerizable compound, and a hypophosphorous acid diester compound. The ink composition is an ink composition for forming a light conversion layer (for example, for forming a pixel portion of a color filter) for forming a light conversion layer possessed by a color filter, etc., and is composed of ink The object is irradiated with light to polymerize and harden the photopolymerizable compound to form a light conversion layer (for example, a color filter pixel portion) including a hardened object of the ink composition.

According to the light conversion layer obtained from the ink composition, excellent external quantum efficiency can be obtained. In addition, the ink composition containing the photopolymerizable compound may react with the photopolymerizable compound during storage due to the catalyst action of the additive depending on the additives contained, and the viscosity may increase, but the hypophosphorous acid diester compound It is not easy to cause the viscosity of the ink composition to increase. Therefore, the ink composition tends to be excellent in viscosity stability.

The ink composition can be applied as an ink used in a known and conventional color filter manufacturing method, but it is preferably used as an inkjet ink composition used in an inkjet method. In terms of forming the pixel portion (light conversion layer) only in the required portion and using the required amount without consuming relatively expensive materials such as luminescent nanocrystalline grains and solvents, the ink composition is preferably It is appropriately prepared and used in a method that is more suitable for inkjet applications than for photolithography applications.

Hereinafter, the inkjet ink composition for forming the pixel portion of the color filter constituting the light conversion layer is taken as an example, and the ink composition and its constituent components of the present embodiment will be described. As constituent components, in addition to light-emitting nanocrystals, photopolymerizable compounds, and hypophosphorous acid diester compounds, organic ligands, photopolymerization initiators, antioxidants other than hypophosphorous acid diester compounds, and light scattering Reactive particles, polymer dispersants, etc.

[Luminescent Nanocrystalline Grains] Luminescent nanocrystalline grains are nano-sized crystals that absorb excitation light and emit fluorescence or phosphorescence. For example, they are crystals with a maximum particle size of 100 nm or less as measured by a transmission electron microscope or a scanning electron microscope.

Luminescent nanocrystals can emit light (fluorescence or phosphorescence) of a wavelength different from the absorbed wavelength, for example, by absorbing light of a predetermined wavelength. The luminescent nanocrystal grains may be red luminescent nanocrystal grains (red luminescent nanocrystal grains) that emit light (red light) with a luminous peak wavelength in the range of 605 nm to 665 nm. Green light-emitting nanocrystals (green light-emitting nanocrystals) that have light (green light) with a peak emission wavelength in the range of 500 nm to 560 nm, or emit light in the range of 420 nm to 480 nm Blue light-emitting nanocrystal grains (blue light-emitting nanocrystal grains) of light with a peak wavelength (blue light). The ink composition preferably contains at least one of the luminescent nano crystal grains. In addition, the light absorbed by the luminescent nanocrystal grains may be light (blue light) having a wavelength in the range of 400 nm or more and less than 500 nm (especially light having a wavelength in the range of 420 nm to 480 nm), or 200 nm. Light (ultraviolet light) with a wavelength in the range of ~400 nm. In addition, the emission peak wavelength of the luminescent nanocrystal grains can be confirmed in, for example, a fluorescence spectrum or a phosphorescence spectrum measured using a spectrofluorometer.

The red luminescent nanocrystal grains are preferably 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 Below, 643 nm or less, 640 nm or less, 637 nm or less, 635 nm or less, 632 nm or less, or 630 nm or less has an emission peak wavelength, and preferably 628 nm or more, 625 nm or more, 623 nm or more, or 620 nm or more , 615 nm or more, 610 nm or more, 607 nm or more, or 605 nm or more have a peak emission wavelength. These upper limit and lower limit can be combined arbitrarily. In addition, in the same description below, the upper limit value and the lower limit value described separately may be combined arbitrarily.

The green light-emitting nanocrystal grains are preferably 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 The luminescence peak wavelength is below, 532 nm or below, or 530 nm or below, and preferably 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 above or above 500 nm has a peak wavelength of luminescence.

The blue luminescent nanocrystal grains are preferably 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 It has an emission peak wavelength below nm, 452 nm or below 450 nm, and is preferably 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 Above or above 420 nm, it has an emission peak wavelength.

According to the solution of the Schrodinger wave equation of the well-type potential model, the wavelength (luminous color) of the light emitted by the luminescent nanocrystal grains depends on the size of the luminescent nanocrystal grains (such as particle size). ), but it also depends on the energy gap of the luminescent nanocrystalline grains. Therefore, the luminous color can be selected by changing the constituent material and size of the luminescent nanocrystal grains used.

The light-emitting nanocrystal grains may be light-emitting nanocrystal grains (light-emitting semiconductor nanocrystal grains) containing a semiconductor material. Examples of the light-emitting semiconductor nanocrystal grains include quantum dots, quantum rods, and the like. Among these, in terms of easy control of the emission spectrum, ensuring reliability, reducing production costs, and improving mass productivity, quantum dots are preferred.

The light-emitting semiconductor nanocrystal grains may be composed only of a core containing the first semiconductor material, or may have a core containing the first semiconductor material, and a core containing a second semiconductor material different from the first semiconductor material and covering the core. At least part of the shell. In other words, the structure of the light-emitting semiconductor nanocrystal grains may be a structure composed only of a core (core structure), or a structure including a core and a shell (core/shell structure). Moreover, in addition to the shell (first shell) containing the second semiconductor material, the light-emitting semiconductor nanocrystalline grains may also have a third semiconductor material that is different from the first semiconductor material and the second semiconductor material and cover the The shell (second shell) of at least part of the core. In other words, the structure of the light-emitting semiconductor nanocrystal grains may be a structure including a core, a first shell, and a second shell (core/shell/shell structure). The core and the shell may be mixed crystals containing two or more semiconductor materials (for example, CdSe+CdS, CIS+ZnS, etc.).

The luminescent nanocrystalline grains preferably comprise selected from the group consisting of group II-VI semiconductors, group III-V semiconductors, group I-III-VI semiconductors, group IV semiconductors, and group I-II-IV-VI semiconductors At least one of the semiconductor materials is used as a semiconductor material.

Specific semiconductor materials include 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, HgZnSeGaN, AlGa, Al, As InP, InAs, InSb, GaNP, GaNAS, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlNAPAs, GaAlPSb, GaInNP, GaInNP GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, Se, PbSTe, PnPbTe SnPbSTe; Si, Ge, SiC, SiGe, AgInSe 2, CuGaSe 2, CuInS 2, CuGaS 2, CuInSe 2, AgInS 2, AgGaSe 2, AgGaS 2, C, Si and Ge. From the viewpoints of easy control of the emission spectrum, ensuring reliability, reducing production costs, and improving mass productivity, the light-emitting semiconductor nanocrystalline grains preferably include those selected from CdS, CdSe, CdTe, ZnS, ZnSe, and ZnTe , ZnO, HgS, HgSe, HgTe , InP, InAs, InSb, GaP, GaAs, GaSb, AgInS 2, AgInSe 2, AgInTe 2, AgGaS 2, AgGaSe 2, AgGaTe 2, CuInS 2, CuInSe 2, CuInTe 2, CuGaS 2 , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge, and Cu ₂ ZnSnS ₄ at least one of the group consisting of.

Examples of red-emitting semiconductor nanocrystal grains include CdSe nanocrystal grains, nanocrystal grains with a core/shell structure and the shell part is CdS, and the inner core part is CdSe, and a core/shell structure. And the shell part is CdS, the inner core part is ZnSe nanocrystal grains, CdSe and ZnS mixed crystal nanocrystal grains, InP nanocrystal grains, with a core/shell structure and the shell part is ZnS, The inner core is InP nanocrystalline grains, the core/shell structure is a mixed crystal of ZnS and ZnSe, and the inner core is InP nanocrystalline grains, and the CdSe and CdS mixed crystal nanos Crystal grains, nano grains of mixed crystals of ZnSe and CdS, nano grains with a core/shell/shell structure and the first shell part is ZnSe, the second shell part is ZnSe, and the inner core part is InP. Core/shell/shell structure, the first shell part is a mixed crystal of ZnS and ZnSe, the second shell part is ZnS, and the inner core part is InP nanocrystals, etc.

As green light-emitting semiconductor nanocrystal grains, for example, CdSe nanocrystal grains, CdSe and ZnS mixed crystal nanocrystal grains, have a core/shell structure and the shell part is ZnS, and the inner core part is InP nano grains, with a core/shell structure and the shell part is a mixed crystal of ZnS and ZnSe, the inner core part is InP nano grains, with a core/shell/shell structure and the first shell part is ZnSe , The second shell part is ZnS, the inner core part is InP nanograins, with a core/shell/shell structure and the first shell part is a mixed crystal of ZnS and ZnSe, the second shell part is ZnS, the inner core The part is InP nano grains, etc.

As blue light-emitting semiconductor nanocrystal grains, for example, ZnSe nanocrystal grains, ZnS nanocrystal grains, and nanocrystals with a core/shell structure in which the shell part is ZnSe and the inner core part is ZnS can be cited. Crystal grains, CdS nano grains, nano grains with a core/shell structure and the shell part is ZnS, and the inner core part is InP, with a core/shell structure and the shell part is a mixed crystal of ZnS and ZnSe , The inner core part is InP nano grains, with core/shell/shell structure, the first shell part is ZnSe, the second shell part is ZnS, and the inner core part is InP nano grains, with core/shell structure. Shell/shell structure, the first shell part is a mixed crystal of ZnS and ZnSe, the second shell part is ZnS, and the inner core part is InP nanocrystalline grains.

Semiconductor nanocrystalline grains have the same chemical composition. By changing their average particle size, the color of the light that should be emitted from the particles can be changed to red or green. Furthermore, it is preferable to use semiconductor nanocrystal grains that have extremely low adverse effects on the human body and the like on their own. When semiconductor nanocrystal grains containing cadmium, selenium, etc. are used as luminescent nanocrystal grains, it is preferable to select semiconductor nanocrystal grains that do not contain these elements (cadmium, selenium, etc.) as much as possible and use them alone , Or used in combination with other luminescent nano grains to minimize the elements.

The shape of the luminescent nanocrystal grains is not particularly limited, and may be any geometric shape or any irregular shape. The shape of the luminescent nanocrystal grains may be, for example, a spherical shape, an ellipsoid shape, a pyramid shape, a disc shape, a dendritic shape, a mesh shape, a rod shape, and the like. However, in terms of further improving the uniformity and fluidity of the ink composition, as the luminescent nanocrystal grains, it is preferable to use particles having a particle shape and less directivity (for example, spherical, regular tetrahedral, etc.). particle of).

From the viewpoint of easily obtaining light emission of the desired wavelength and the viewpoint of excellent dispersibility and storage stability, the average particle diameter (volume average diameter) of the luminescent nanocrystal grains may be 1 nm or more, and may be 1.5 nm or more. It can also be 2 nm or more. From the viewpoint of easily obtaining the desired emission wavelength, it may be 40 nm or less, 30 nm or less, or 20 nm or less. The average particle diameter (volume average diameter) of the luminescent nanocrystal grains is obtained by measuring with a transmission electron microscope or a scanning electron microscope, and calculating the volume average diameter.

From the viewpoint of dispersion stability, the luminescent nanocrystal grains preferably have an organic ligand on their surface. For example, the surface of luminescent nanocrystalline grains can be passivated by organic ligands. Organic ligands can be coordinately bonded to the surface of the luminescent nanocrystal grains. The details of the organic ligand will be described later.

The luminescent nanocrystal particles may have a polymer dispersant on their surface. For example, by exchanging the organic ligand bound to the surface of the light-emitting nanocrystal particles with the polymer dispersant, the polymer dispersant can be bonded to the surface of the light-emitting nanocrystal particles. However, from the viewpoint of dispersion stability when forming an inkjet ink, it is preferable to formulate a polymer dispersant to the light-emitting nanocrystal particles in a state where an organic ligand is coordinated. The details of the polymer dispersant will be described later.

As the luminescent nanocrystal particles, those dispersed in a colloidal form in a solvent, a photopolymerizable compound, etc. can be used. The surface of the luminescent nanocrystal grains in a dispersed state is preferably passivated by an organic ligand. Examples of solvents include cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether, propylene glycol monomethyl ether acetate, and butyl carbitol acetic acid. Esters, or mixtures of these.

As the luminescent nanocrystal grains, commercially available products can be used. As commercially available products of luminescent nanocrystalline grains, for example, indium phosphorus/zinc sulfide of NN-Labs, D-dots, CuInS/ZnS, Aldrich (Aldrich) ) The company's InP/ZnS, etc.

From the viewpoint of further improving the external quantum efficiency of the pixel portion, based on the total mass of the ink composition, the content of the luminescent nanocrystal grains is 20% by mass or more, or 22% by mass or more and 24% by mass Or above or above 26% by mass. From the viewpoint of further improving the ejection stability and the external quantum efficiency of the pixel portion, based on the total mass of the ink composition, the content of the luminescent nanocrystal particles is preferably 80% by mass or less, or 70% by mass. % Or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less. From these viewpoints, based on the total mass of the ink composition, the content of the luminescent nanocrystal grains can be, for example, 20% by mass to 80% by mass, 22% by mass to 70% by mass, or 24% by mass to 60% by mass. %, 24% by mass to 50% by mass, or 26% by mass to 40% by mass. In addition, the content of the luminescent nanocrystalline grains does not include the amount of organic ligands bonded to the luminescent nanocrystalline grains. In addition, in this specification, the "total mass of the ink composition" may be changed to the component that should be contained in the cured product of the ink composition. That is, when the ink composition contains a solvent, it refers to components other than the solvent contained in the ink composition, and unless otherwise specified, the amount of the solvent is not included in the total mass of the ink composition. The "total mass of the ink composition" is, for example, the total of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, hypophosphorous acid diester compounds, antioxidants, light scattering particles, and polymer dispersants.

The ink composition may include two or more of the red light-emitting nanocrystal grains, the green light-emitting nanocrystal grains, and the blue light-emitting nanocrystal grains as the light-emitting nanocrystal grains, but preferably contains only these One of the particles. When the ink composition contains red luminescent nanocrystalline grains, the content of green luminescent nanocrystalline grains and the content of blue luminescent nanocrystalline grains are based on the total mass of luminescent nanocrystalline grains. It is preferably 10% by mass or less, and more preferably 0% by mass. When the ink composition contains green light-emitting nanocrystals, the content of red light-emitting nanocrystals and the content of blue light-emitting nanocrystals are based on the total mass of the light-emitting nanocrystals. It is preferably 10% by mass or less, and more preferably 0% by mass.

[Organic Ligand] The organic ligand exists near the surface of the luminescent nanocrystal grains and has a function of dispersing the luminescent nanocrystal grains. The organic ligand includes, for example, a functional group (hereinafter also referred to as "affinity group") for ensuring affinity with photopolymerizable compounds, solvents, etc., and a functional group capable of bonding to luminescent nanocrystal grains ( The functional group used to ensure the adsorptivity to the luminescent nanocrystal grains) exists near the surface of the luminescent nanocrystal grain by coordinate bonding to the surface of the luminescent nanocrystal grain.

The affinity group may be a substituted or unsubstituted aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or may have a branched structure. Furthermore, the aliphatic hydrocarbon group may or may not have an unsaturated bond. The substituted aliphatic hydrocarbon group may be a group in which a part of the carbon atoms of the aliphatic hydrocarbon group is substituted with oxygen atoms. The substituted aliphatic hydrocarbon group may include, for example, a (poly)oxyalkylene group. 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 connected via an ether bond.

Examples of the functional group capable of bonding to the luminescent nanocrystal grains include a hydroxyl group, an amino group, a carboxyl group, a thiol group, a phosphoric acid group, a phosphonic acid group, a phosphine group, a phosphine oxide group, and an alkoxysilyl group.

Examples of organic ligands include trioctylphosphine (TOP), trioctylphosphine oxide (TOPO), oleic acid, linoleic acid, linolenic acid, ricinoleic acid, gluconic acid, 16-hydroxyhexadecanoic acid, 12-hydroxystearic acid, N-lauric creatine, N-oleyl creatine, oleylamine, octylamine, trioctylamine, cetylamine, octane Mercaptan, dodecyl mercaptan, hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), phenylphosphonic acid, and octyl phosphonic acid (OPA).

In one embodiment, the organic ligand may be an organic ligand represented by the following formula (1-1).

[式（1-1）中，p表示0～50的整數，q表示0～50的整數。][化3]

[In formula (1-1), p represents an integer of 0-50, and q represents an integer of 0-50. ]

In the organic ligand represented by formula (1-1), it is preferable that at least one of p and q is 1 or more, and it is more preferable that both of p and q are 1 or more.

The organic ligand may be, for example, an organic ligand represented by the following formula (1-2).

[化4]

In formula (1-2), A ¹ represents a monovalent group containing a carboxyl group, A ² represents a monovalent group containing a hydroxyl group, R represents a hydrogen atom, a methyl group or an ethyl group, and L represents a substituted or unsubstituted alkylene group. Base, r represents an integer of 0 or more. The number of carboxyl groups in the monovalent group containing a carboxyl group may be two or more, two or more and four or less, or two. The carbon number of the alkylene group represented by L may be 1-10, for example. In the alkylene group represented by L, a part of the carbon atoms may be substituted by a hetero atom, or may be substituted by at least one hetero atom selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom. r may be an integer of 1-100, or may be an integer of 10-20, for example.

From the viewpoint of excellent external quantum efficiency of the pixel portion (cured material of the ink composition), the organic ligand may be an organic ligand represented by the following formula (1-2A).

[化5]

In formula (1-2A), r has the same meaning as described above.

In one embodiment, the organic ligand may be an organic ligand represented by the following formula (1-3).

[化6]

In formula (1-3), n represents an integer of 0-50, and m represents an integer of 0-50. n is preferably 0-20, more preferably 0-10. m is preferably 0-20, more preferably 0-10. It is preferable that at least one of n and m is 1 or more. That is, n+m is preferably 1 or more. n+m may be 10 or less. Z represents a substituted or unsubstituted alkylene group. The carbon number of the alkylene group may be 1-10, for example. In the alkylene group represented by Z, a part of the carbon atoms may be substituted by a heteroatom, or may be substituted by at least one heteroatom selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom.

In one embodiment, the organic ligand may be an organic ligand represented by the following formula (1-4).

[式（1-4）中，l表示1～50的整數。][化7]

[In formula (1-4), l represents an integer of 1-50. ]

In the organic ligand represented by formula (1-4), l may be 1-20, 3-15, 5-10, or 7.

From the viewpoint of the dispersion stability of the luminescent nanocrystal grains and the viewpoint of maintaining the luminescence characteristics, the content of the organic ligand in the ink composition can be 10 parts by mass or more relative to 100 parts by mass of the luminescent nanocrystal grains. , 20 parts by mass or more, 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 can be 50 parts by mass or less, 45 parts by mass or less with respect to 100 parts by mass of the luminescent nanocrystal grains, 40 parts by mass or less or 30 parts by mass or less. From these viewpoints, the content of the organic ligand relative to 100 parts by mass of the luminescent nanocrystal grains may be, for example, 10 parts by mass to 50 parts by mass, or 10 parts by mass to 15 parts by mass.

[Photopolymerizable compound] The photopolymerizable compound is a compound that is polymerized by irradiation of light (active energy rays), and is basically used with a photopolymerization initiator.

The molecular weight of the photopolymerizable compound is, for example, 50 or more, and may be 100 or more or 150 or more. The molecular weight of the photopolymerizable compound is, for example, 500 or less, and may be 400 or less or 300 or less. From the viewpoint of facilitating compatibility between the viscosity of the inkjet ink and the volatility of the ink after ejection, it is preferably 50 to 500, and more preferably 100 to 400.

The photopolymerizable compound may be a radical polymerizable compound, a cation polymerizable compound, or an anionic polymerizable compound. The photopolymerizable compound is preferably a radical polymerizable compound.

The radically polymerizable compound is, for example, a compound having an ethylenically unsaturated group. In this specification, an ethylenically unsaturated group means a group having an ethylenically unsaturated bond (polymerizable carbon-carbon double bond). The number of ethylenically unsaturated bonds in the compound having ethylenically unsaturated groups (for example, the number of ethylenically unsaturated groups) is 1 to 3, for example.

As the compound having an ethylenically unsaturated group, for example, a compound having an ethylenically unsaturated group such as a vinyl group, an vinylidene group, a vinylene group, and a (meth)acryloyl group. From the viewpoint of further improving the external quantum efficiency, a compound having a (meth)acryloyl group is preferable, a monofunctional or polyfunctional (meth)acrylate is more preferable, and a monofunctional or difunctional compound is more preferable.的(meth)acrylate. In addition, in this specification, "(meth)acryloyl group" means "acryloyl group" and its corresponding "methacryloyl group". The same applies to the expression of "(meth)acrylate". In addition, a monofunctional (meth)acrylate refers to a (meth)acrylate having one (meth)acrylic acid group, and a multifunctional (meth)acrylate refers to a (meth)acrylate having two or more (meth)acrylic groups. Acetyl (meth)acrylate.

Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and (meth)acrylate. Amyl acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylhexyl diethylene glycol (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, (meth)acrylate Base) dodecyl acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, methoxyethyl (meth)acrylate , Methoxytriethylene glycol (meth)acrylate, Methoxytripropylene glycol (meth)acrylate, Polyethylene glycol (meth)acrylate, Butoxyethyl (meth)acrylate, ( Phenoxy ethyl meth)acrylate, phenoxy diethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, nonyl phenoxy ethyl (meth) acrylate , Glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, Isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenoxyethyl (meth)acrylate, (methyl) ) 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (meth) Benzyl acrylate, phenyl benzyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, γ-butyrolactone (meth)acrylate, adamantyl (meth)acrylate, cyclic trihydroxyl Methylpropane formaldehyde (meth)acrylate, mono(2-propenoxyethyl) succinate, N-[2-(propenyloxy)ethyl]phthalimide, N- [2-(Allyloxy)ethyl] tetrahydrophthalimide and the like.

Examples of polyfunctional (meth)acrylates include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,5-pentanedi Alcohol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di( Meth) acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, Ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate Ester, polypropylene glycol di(meth)acrylate, neopentyl glycol hydroxypivalate diacrylate, two hydroxyl groups of tris(2-hydroxyethyl) isocyanurate are (meth)acrylic acid Di (meth) acrylate substituted by a group, 2 hydroxy groups of a diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol are (meth)propylene Di(meth)acrylate substituted with oxo group, 2 mol of ethylene oxide or propylene oxide is added to 1 mol of bisphenol A, and the 2 hydroxyl groups of the diol are (meth)propylene Di(meth)acrylate substituted with oxo group, 2 hydroxy groups of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane are Base) di(meth)acrylate substituted with acryloxy group, 2 hydroxy groups of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A are ( Difunctional (meth)acrylates such as di(meth)acrylate substituted with meth)acryloyloxy; glycerol tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tri Trifunctional (meth)acrylates such as methylolpropane triacrylate and triethylpropane ethylene oxide addition triacrylate.

From the viewpoint of reducing stickiness (stickiness) on the surface of the cured product of the ink composition, as the photopolymerizable compound, a radical polymerizable compound having a cyclic structure is preferably used. The cyclic structure may be an aromatic ring structure or a non-aromatic ring structure. The number of cyclic structures (the total number of aromatic rings and non-aromatic rings) may be 1, or may be 2 or more. The number of cyclic structures may also be 3 or less. The number of carbon atoms constituting the cyclic structure is, for example, 4 or more, and may be 5 or more or 6 or more. The number of carbon atoms is, for example, 20 or less, or 18 or less.

The aromatic ring structure may be a structure having an aromatic ring having 6 to 18 carbon atoms, for example. Examples of the aromatic ring having 6 to 18 carbon atoms include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. The aromatic ring structure may be a structure having an aromatic heterocyclic ring. As an aromatic heterocyclic ring, a furan ring, a pyrrole ring, a pyran ring, a pyridine ring etc. are mentioned, for example. The number of aromatic rings may be one or two or more. The number of aromatic rings may also be 3 or less. The organic group may have a structure in which two or more aromatic rings are bonded by a single bond (for example, a biphenyl structure).

The non-aromatic ring structure may be a structure having an alicyclic ring having 5 to 20 carbon atoms, for example. Examples of alicyclic rings having 5 to 20 carbon atoms include cycloalkane rings such as cyclopentane ring, cyclohexane ring, cycloheptane ring, and cyclooctane ring, cyclopentene ring, cyclohexene ring, and cycloheptene ring. Cycloalkene ring such as ring, cyclooctene ring, etc. The alicyclic ring may be a condensed ring such as a bicycloundecane ring, a decalin ring, a norbornene ring, a norbornadiene ring, an isobornyl ring, and the like. The non-aromatic ring structure may also be a structure having a non-aromatic heterocyclic ring. As a non-aromatic heterocyclic ring, a tetrahydrofuran ring, a pyrrolidine ring, a tetrahydropyran ring, a piperidine ring, etc. are mentioned, for example.

The radically polymerizable compound having a cyclic structure is preferably a monofunctional or polyfunctional (meth)acrylate having a cyclic structure, and more preferably a monofunctional (meth)acrylate having a cyclic structure. Specifically, phenoxyethyl (meth)acrylate, phenoxybenzyl (meth)acrylate, biphenyl (meth)acrylate, isobornyl (meth)acrylate, and (meth)acrylate are preferably used. Base) tetrahydrofuran acrylate, dicyclopentenoxyethyl (meth)acrylate.

From the viewpoint of easily suppressing stickiness (stickiness) on the surface of the ink composition, based on the total mass of the ink composition, the content of the radically polymerizable compound having a cyclic structure can be 3% by mass or more, 5% by mass % Or more or 10% by mass or more. From the viewpoints of easily obtaining viscosity suitable for inkjet inks and easily obtaining excellent ejection properties, based on the total mass of the ink composition, the content of the radically polymerizable compound having a cyclic structure may be 80% by mass or less , 60% by mass or less or 45% by mass or less.

From the viewpoint of easily obtaining excellent ejection properties, it is preferable to use a radically polymerizable compound having a linear structure having 4 or more carbon atoms as the ink composition. The linear structure may be a structure in which atoms other than hydrogen atoms are connected without branching, and may have heteroatoms such as oxygen atoms in addition to carbon atoms and hydrogen atoms. That is, the linear structure is not limited to a structure in which four or more carbon atoms are continuous in a linear form, and may be a structure in which four or more carbon atoms are connected to each other in a linear form via a heteroatom such as an oxygen atom. The linear structure may have unsaturated bonds, but preferably contains only saturated bonds. The number of carbon atoms constituting the linear structure is preferably 5 or more, more preferably 6 or more, and still more preferably 7 or more. The number of carbon atoms constituting the linear structure is preferably 25 or less, more preferably 20 or less, and still more preferably 15 or less. Furthermore, from the viewpoint of ejectability, it is preferable that the radically polymerizable compound having a linear structure with a total carbon number of 4 or more does not have a cyclic structure.

The linear structure may be a structure having a linear alkyl group having 4 or more carbon atoms, for example. Examples of linear alkyl groups having 4 or more carbons include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, Myristyl, pentadecyl, etc. As a radically polymerizable compound having such a structure, it is preferable to use an alkyl (meth)acrylate in which the linear alkyl group and the (meth)acryloxy group are directly bonded.

The linear structure may be, for example, a structure having a linear alkylene group having 4 or more carbon atoms. Examples of straight-chain alkylenes having 4 or more carbon atoms include: butylene, pentylene, hexylene, heptylene, octylene, nonylylene, decylene, undecylene, and Dodecyl, tridecylene, tetradecyl, pentadecyl, etc. As a radically polymerizable compound having such a structure, it is preferable to use an alkylene glycol di(meth)acrylic acid in which two (meth)acryloyloxy groups are bonded via the linear alkylene group. ester.

The linear structure may be, for example, a structure in which a linear alkyl group and one or more linear alkylene groups are bonded via an oxygen atom (a structure having an alkyl (poly)oxyalkylene group). The number of linear alkylene groups may be 2 or more, and may also be 6 or less. When the number of linear alkylene groups is 2 or more, the two or more alkylene groups may be the same or different. The carbon number of the straight-chain alkyl group and the straight-chain extended alkyl group may be 1 or more, and may be 2 or more or 3 or more. The carbon number of the linear alkyl group and the linear extended alkyl group may be 4 or less. As the linear alkyl group, in addition to the linear alkyl group having 4 or more carbon atoms, a methyl group, an ethyl group, and a propyl group can be cited. As the linear alkylene group, in addition to the linear alkylene group having a carbon number of 4 or more, a methylene group, an ethylene group, and a propylene group can be exemplified. As a radically polymerizable compound having such a structure, it is preferable to use an alkyl(poly)oxyalkylene group in which a (meth)acryloyloxy group is directly bonded to the alkyl(poly)oxyalkylene group. (Meth)acrylate.

From the viewpoints of easily obtaining viscosity suitable for inkjet inks, easy obtaining of excellent ejection properties, and excellent curability of the ink composition, based on the total mass of the ink composition, it has a straight line with a carbon number of 4 or more. The content of the radically polymerizable compound of the chain structure may be 1% by mass or more, 3% by mass or more, or 5% by mass or more. From the viewpoint of easily suppressing stickiness (stickiness) on the surface of the ink composition, based on the total mass of the ink composition, the content of the radically polymerizable compound having a linear structure with a carbon number of 4 or more can be 80 mass % Or less, 60% by mass or less, or 45% by mass or less.

As the photopolymerizable compound, from the viewpoint of excellent uniformity of the pixel portion surface, it is preferable to use two or more kinds of radical polymerizable compounds, and it is more preferred to combine the radical polymerizable compound having a cyclic structure with The radically polymerizable compound having a linear structure having a carbon number of 4 or more is used in combination. In the case of increasing the amount of luminescent nanocrystals in order to increase the external quantum efficiency, the surface uniformity of the pixel portion may be reduced, but in this case, depending on the combination of the photopolymerizable compound, There is a tendency to obtain a pixel portion with excellent surface uniformity.

When the radically polymerizable compound having a cyclic structure and the radically polymerizable compound having a linear structure with a carbon number of 4 or more are used in combination, the point of view that the uniformity of the pixel portion surface is excellent In other words, the mass ratio (M ₂ /M ₁ ) _{of the content M 2} of the radical polymerizable compound having a linear structure having a carbon number of 4 or more _{relative to the content M 1 of the radical polymerizable compound having a cyclic structure} It is preferably from 0.05 to 5, more preferably from 0.1 to 3, and still more preferably from 0.1 to 1.

The photopolymerizable compound may be alkali-insoluble from the viewpoint of easily obtaining a pixel portion (cured material of the ink composition) with excellent reliability. In this specification, the fact that the photopolymerizable compound is alkali-insoluble means that the amount of the photopolymerizable compound dissolved in a 1% by mass potassium hydroxide aqueous solution at 25° C. is 30% by mass or less based on the total mass of the photopolymerizable compound. The dissolved amount of the photopolymerizable compound is preferably 10% by mass or less, more preferably 3% by mass or less.

From the viewpoint of easy availability of viscosity suitable for inkjet inks, the viewpoint that the curability of the ink composition becomes better, and the viewpoint that the solvent resistance and abrasion resistance of the pixel portion (the cured product of the ink composition) are improved In other words, the content of the photopolymerizable compound is based on the total mass of the ink composition, and may be 10% by mass or more, 15% by mass or more, or 20% by mass or more. From the standpoint of easily obtaining the viscosity suitable for inkjet ink and the standpoint of obtaining more excellent optical properties (such as external quantum efficiency), the content of the photopolymerizable compound may be 60 based on the total mass of the ink composition. The mass% or less may be 50 mass% or less, 40 mass% or less, 30 mass% or less, or 20 mass% or less. From these viewpoints, the content of the photopolymerizable compound is based on the total mass of the ink composition, and may be, for example, 10% by mass to 60% by mass, 15% by mass to 50% by mass, 20% by mass to 40% by mass, or 20% by mass to 30% by mass.

[Photopolymerization initiator] Examples of the photopolymerization initiator that can be contained in the ink composition include photoradical polymerization initiators. As the photoradical polymerization initiator, a molecular cleavage type or dehydrogenation type photoradical polymerization initiator is preferred.

As the molecular cleavage type photo-radical polymerization initiator, benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2,4,6- Trimethylbenzyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butane-1-one, bis(2,6 -Dimethoxybenzyl)-2,4,4-trimethylpentylphosphine oxide, (2,4,6-trimethylbenzyl)ethoxyphenylphosphine oxide, etc. As a molecular cleavage type photo-radical polymerization initiator other than these, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzyl dimethyl ketal, 2-hydroxy-2-methyl can also be used in combination. -1-Phenylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 2-methyl-1-(4-methylthio) (Phenyl)-2-morpholinopropan-1-one.

Examples of dehydrogenation-type photoradical polymerization initiators include benzophenone, 4-phenylbenzophenone, meta-benzophenone, and 4-benzyl-4'-methyl-benzophenone. Base sulfide and so on. It is also possible to use a molecular cleavage-type photo-radical polymerization initiator and a dehydrogenation-type photo-radical polymerization initiator in combination.

From the viewpoint of the curability of the ink composition, the content of the photopolymerization initiator relative to 100 parts by mass of the photopolymerizable compound may be 0.1 parts by mass or more, 0.5 parts by mass or more, or 1 part by mass or more, It may be 3 parts by mass or more, or 5 parts by mass or more. From the viewpoint of the temporal stability of the pixel portion (the cured product of the ink composition), the content of the photopolymerization initiator relative to 100 parts by mass of the photopolymerizable compound may be 40 parts by mass or less, and may be 30 parts by mass Below, it may be 20 parts by mass or less, or 10 parts by mass or less. From these viewpoints, the content of the photopolymerization initiator can be, for example, 0.1 to 40 parts by mass relative to 100 parts by mass of the photopolymerizable compound.

[Hypophosphorous acid diester compound] The hypophosphorous acid diester compound is a compound in which the two hydroxyl groups of hypophosphorous acid (phosphonous acid) are each esterified.

The hypophosphorous acid diester compound has a structure represented by the following formula (I), for example.

[式（I）中，X¹ 表示氧原子或硫原子，R¹ 表示氫原子或有機基（其中，與式（I）中的P（磷原子）直接鍵結的原子為碳原子），R² 表示烴基。多個X¹ 彼此可相同亦可不同。多個R² 彼此可相同亦可不同。][化8]

[In formula (I), X ¹ represents an oxygen atom or a sulfur atom, R ¹ represents a hydrogen atom or an organic group (wherein, the atom directly bonded to P (phosphorus atom) in formula (I) is a carbon atom), R ² represents a hydrocarbon group. A plurality of X ¹ may be the same as or different from each other. A plurality of R ² may be the same or different from each other. ]

In formula (I), X ^{1 is} preferably an oxygen atom.

In formula (I), R ^{1 is} preferably an organic group (wherein, the atom directly bonded to P is a carbon atom). The organic group may be a hydrocarbon group, or may have a heteroatom such as an oxygen atom, a nitrogen atom, and a phosphorus atom in addition to a carbon atom and a hydrogen atom. The organic group may be a structure represented by the following formula (Ia), for example.

[式（Ia）中，*表示與磷原子的鍵結鍵。Y表示連結基（其中，與式（Ia）中的P（磷原子）直接鍵結的原子為碳原子）。X^1a 及R^2a 分別與式（I）中的X¹ 及R² 同義。][化9]

[In formula (Ia), * represents the bonding bond with the phosphorus atom. Y represents a linking group (wherein, the atom directly bonded to P (phosphorus atom) in formula (Ia) is a carbon atom). X ^1a and R ^2a are synonymous with ^{X 1} and R ² in formula (I), respectively. ]

The organic group preferably has an aromatic ring. The number of aromatic rings may be one or two or more. The number of aromatic rings may be 3 or less. The number of carbon atoms constituting the aromatic ring is, for example, 6-18. Examples of the aromatic ring having 6 to 18 carbon atoms include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. The organic group may have a structure in which two or more aromatic rings are bonded by a single bond (for example, a biphenyl structure).

In formula (I), R ^{2 is} preferably an aryl group. That is, the hypophosphorous acid diester compound is preferably a compound represented by the following formula (II).

[式（II）中，Ar¹ 表示芳基，X¹ 及R¹ 分別與式（I）中的X¹ 及R¹ 同義。兩個X¹ 彼此可相同亦可不同，兩個Ar¹ 彼此可相同亦可不同。][化10]

[In the formula (II), Ar ¹ represents an aryl group, X ¹ and R ¹ are synonymous with the respective ^one of the formula (I) X ¹ and R. Two X ¹ may be the same or different from each other, and two Ar ¹ may be the same or different from each other. ]

When the hypophosphorous acid diester compound is a compound represented by the above formula (II), the hypophosphorous acid diester compound and the photopolymerizable compound are in a well-compatible state, and it is easier to show that the hypophosphorous acid diester compound acts as an antioxidant. From a functional point of view, the ink composition preferably contains the above-mentioned radically polymerizable compound having a cyclic structure.

Aryl is a group formed by removing a hydrogen atom bonded to the ring of a monocyclic or polycyclic aromatic hydrocarbon, and part of the hydrogen atom bonded to the aromatic hydrocarbon ring is substituted by a hydrocarbon group Groups (for example, di-tertiary butylphenyl groups having 1 to 3 alkyl groups with 1 to 6 carbon atoms as substituents of the aromatic hydrocarbon ring) are also included in the aryl group.

The number of carbon atoms of the aryl group is, for example, 6-18. The aromatic ring possessed by the aryl group may be a single ring or a condensed ring. The aryl group may be, for example, a substituted or unsubstituted phenyl group, and may also be a substituted or unsubstituted naphthyl group. The aryl group may have an aromatic ring other than the aromatic ring directly bonded ^{to X 1.} For example, the aryl group may also be a biphenyl group.

The aryl group is particularly preferably a substituted or unsubstituted phenyl group. The substituent on the aromatic nucleus is preferably an alkyl group having 1 to 6 carbon atoms. The number of substituents is preferably 1 to 3 per aromatic nucleus. The aryl group is preferably an unsubstituted phenyl group, or a monoalkylbenzene having 1 to 3 alkyl groups (preferably an alkyl group having 1 to 6 carbon atoms) as a substituent on the aromatic nucleus Group, dialkylphenyl, or trialkylphenyl. Here, the alkyl group having 1 to 6 carbon atoms may be linear or branched. Examples of linear alkyl groups include methyl, ethyl, n-propyl, n-butyl, and n-hexyl. As the branched alkyl group, an isopropyl group, an isobutyl group, a second butyl group, a tertiary butyl group, etc. may be mentioned. Among the plurality of R ³ , preferably 1 to 3 are alkyl groups, 2 to 4 are hydrogen atoms, more preferably ^{at least one of the plurality of R 3} is a branched alkyl group, and more preferably a plurality of R ^{At least two of 3} are branched alkyl groups. The branched alkyl group is preferably a tertiary butyl group.

The hypophosphorous acid diester compound preferably has a plurality of hypophosphorous acid diester structures. Specifically, the hypophosphorous acid diester compound preferably has a structure represented by the following formula (IV).

[式（IV）中，Y表示連結基（其中，與式（IV）中的P（磷原子）直接鍵結的原子為碳原子）。X² 及X³ 表示氧原子或硫原子，Ar² 及Ar³ 表示芳基。兩個X² 彼此可相同亦可不同，兩個X³ 彼此可相同亦可不同，兩個Ar² 彼此可相同亦可不同，兩個Ar³ 彼此可相同亦可不同。][化11]

[In formula (IV), Y represents a linking group (wherein, the atom directly bonded to P (phosphorus atom) in formula (IV) is a carbon atom). X ² and X ³ represent an oxygen atom or a sulfur atom, and Ar ² and Ar ³ represent an aryl group. Two X ² may be the same or different from each other, two X ³ may be the same or different from ^{each other, two Ar 2} may be the same or different from ^{each other, and two Ar 3} may be the same or different from each other. ]

X ² and X ^{3 are} preferably oxygen atoms. The details of the aryl group of Ar ² and Ar ³ (including preferred embodiments) are the same as the details of the aryl group of ^{Ar 1 described above.}

In formula (IV), Y is preferably a divalent hydrocarbon group, more preferably a divalent hydrocarbon group having an aromatic ring. The aromatic ring is preferably contained in the main chain of the linking group. From this viewpoint, the linking group is preferably an aryl group. As the arylene group, a phenylene group, a biphenylene group, a naphthylene group, etc. may be mentioned.

As a specific example of a preferred hypophosphorous acid diester compound, for example, tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenyldiphosphonic acid Ester), tetrakis(2,4-di-tertiary butylphenyl)-4,4'-biphenyl diphosphonate), bis(2,4-di-tertiary butyl-5-methyl Phenyl)-biphenyl phosphonate, bis(2,4-di-tert-butylphenyl)-biphenyl phosphonate and the like. These can be used alone or in combination of two or more.

From the viewpoint of better external quantum efficiency, based on the total mass of the ink composition, the content of the hypophosphorous acid diester compound may be 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more . From the viewpoint of ensuring better film strength when forming the coating film, further suppressing the bleeding of the hypophosphorous acid diester compound to the surface of the pixel portion, and obtaining more excellent external quantum efficiency, the total mass of the ink composition As a reference, the content of the hypophosphorous acid diester compound may be 10% by mass or less, may be 5% by mass or less, or may be 3% by mass or less. From these viewpoints, the content of the hypophosphorous acid diester compound is based on the total mass of the ink composition, and may be, for example, 0.01% by mass to 10% by mass, 0.05% by mass to 5% by mass, or 0.1% by mass to 3% by mass. .

[Antioxidants] As long as the effect of the present invention is not hindered, the ink composition may contain a compound that functions as an antioxidant in addition to the phosphite compound. Examples of such compounds include compounds used as conventionally known antioxidants such as phenolic antioxidants, amine antioxidants, and phosphorus-based antioxidants other than hypophosphorous acid diester compounds, and sulfur-based antioxidants. Among these, since the use in combination with a hypophosphorous acid diester compound tends to further suppress the decrease in external quantum efficiency, it is preferable to use a phenolic antioxidant.

Examples of phenolic antioxidants include 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene (product name: AO-330), 2,4-Bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine (product name: Yi Lu Nuo (Irganox 565), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (product name: AO-60), octadecyl 3-(3 ,5-Di-tert-butyl-4-hydroxyphenyl) propionate (product name, AO-50), 2,6-di-tert-butyl-4-nonylphenol, thiodiethylene bis [3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-methylenebis-(6-(1-methylcyclohexyl)-p-methyl Phenol), N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide) (product name: Irganox 1098), 2,5 -Di-tertiary butyl hydroquinone, 2,5-di-tertiary amyl-hydroquinone, 2,4-dimethyl-6-(1-methylcyclohexyl)-phenol, 6-tertiary butyl -O-cresol, 6-tert-butyl-2,4-xylenol, 2,4-dimethyl-6-(1-methylpentadecyl)phenol, 2,4-bis(octyl) Thiomethyl)-o-cresol (product name: Irganox 1520), 2,4-bis(dodecylthiomethyl)-o-cresol, ethylene bis(oxyethylene) Bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 3,9-bis[2-〔3-(tert-butyl-4-hydroxy-5 -Methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane (product name: AO-80), Triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (product name: Irganox 245), 2-tert-pentyl Phenol, 2-tert-butylphenol, 2,4-di-tert-butylphenol, 1,1,3-tris-(2'-methyl-4'-hydroxy-5'-tert-butylbenzene Yl)-butane (product name: AO-30), 4,4'-butylene-bis-(2-tert-butyl-5-methylphenol), etc.

The phenolic antioxidant can be a hindered phenolic antioxidant in which the hydrogen atoms located at the two ortho positions of the phenolic hydroxyl group are substituted by a bulky group, and the hydrogen atom located at one of the ortho positions of the phenolic hydroxyl group is substituted by a bulky group, and the other A semi-hindered phenol antioxidant in which the ortho-position hydrogen atom is substituted by a methyl group and a non-hindered phenol-based antioxidant in which one of the ortho-position hydrogen atoms in the phenolic hydroxyl group is replaced by a three-dimensional bulky group, and the other ortho-position hydrogen atom is unsubstituted Any one of antioxidants. The sterically bulky group refers to a branched alkyl group or an aromatic ring group other than a linear alkyl group. Specifically, examples include tertiary alkyl groups such as tertiary butyl, tertiary pentyl, and tertiary hexyl; secondary alkyl groups such as isopropyl, second butyl, and second pentyl; isobutyl, isopropyl Branched primary alkyl groups such as pentyl; cycloalkyl groups such as cyclohexyl and cyclopentyl; and aromatic ring groups such as phenyl, benzyl, and naphthyl.

The phenol-based antioxidant is preferably a hindered phenol-based antioxidant. Examples of hindered phenol antioxidants include 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene, 2,4-bis-( N-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, pentaerythritol tetrakis[3-(3,5-di-th Tributyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di-third Butyl-4-nonylphenol, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N-hexamethylenebis( 3,5-Di-tert-butyl-4-hydroxy-hydrocinnamamide) and the like. Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is preferably used.

Commercial products of phenolic antioxidants include Adekastab AO-20 and Adekastab AO- which are antioxidants manufactured by ADEKA Co., Ltd. 30. Adekastab AO-40, Adekastab AO-50, Adekastab AO-60, Adekastab AO-60G, Adekastab AO-70, Adekastab AO-80, Adekastab AO-330, etc.; Yi Lu as an antioxidant manufactured by BASF Irganox 1010, Irganox 1010FF, Irganox 1035, Irganox 1035FF (W&C), Irganox 1076, Irganox (Irganox) 1076FD, Irganox 1098, Irganox 1135, Irganox 1330, Irganox 1520L, Irganox 245, Irganox 245FF, Irganox 259, Irganox 3114, etc.; as antioxidants manufactured by Sumitomo Chemical Co., Ltd., SUMILIZER GP, Similize (SUMILIZER) GS(F), SUMILIZER GM(F), SUMILIZER GA-80, SUMILIZER MDP-S, SUMILIZER WX-R, West SUMILIZER (SUMILIZER) WX-RC and so on.

From the viewpoint that it is easier to suppress the decrease in external quantum efficiency, the content of the antioxidant can be 0.01% by mass or more, 0.1% by mass or more, 1% by mass or more, or 5 based on the total mass of the ink composition. Above mass%. From the viewpoint of ensuring better film strength when forming the coating film, further suppressing the bleeding of the antioxidant to the surface, and ensuring good optical properties, the content of the antioxidant is based on the total mass of the ink composition , Preferably 10% by mass or less, more preferably 7% by mass or less, still more preferably 5% by mass or less, and still more preferably 3% by mass or less. Furthermore, the content of the hypophosphorous acid diester compound is not included in the content. In this embodiment, it is preferable that the content of the phenol-based antioxidant is within the above-mentioned range, and it is more preferable that the content of the hindered phenol-based antioxidant is within the above-mentioned range.

[Light Scattering Particles] The light-scattering particles are, for example, optically inactive inorganic fine particles. When the ink composition contains light-scattering particles, the light from the light source irradiated to the pixel portion can be scattered, so that excellent optical properties (for example, external quantum efficiency) can be obtained.

Examples of materials constituting light-scattering particles include elemental metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum (platina), and gold; silicon dioxide, barium sulfate, talc, Clay, kaolin, alumina white, titanium oxide, magnesium oxide, barium oxide, aluminum oxide, bismuth oxide, zirconium oxide, zinc oxide and other metal oxides; magnesium carbonate, barium carbonate, bismuth subcarbonate, calcium carbonate and other metal carbonates; Metal hydroxides such as aluminum hydroxide; composite oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, and strontium titanate; metal salts such as bismuth subnitrate, etc. From the viewpoint of excellent ejection stability and the viewpoint that the effect of improving external quantum efficiency is more excellent, the light-scattering particles are preferably selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, and titanic acid. At least one selected from the group consisting of barium and silicon dioxide, more preferably includes at least one selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, and barium titanate.

The shape of the light-scattering particles may be spherical, filamentous, indefinite shape, or the like. However, as light-scattering particles, in terms of further improving the uniformity, fluidity, and light-scattering properties of the ink composition and obtaining excellent ejection stability, it is preferable to use particles with less directivity as the particle shape. Particles (for example, spherical, tetrahedral, etc.) particles.

From the viewpoint of excellent ejection stability and the viewpoint that the effect of improving the external quantum efficiency is more excellent, the average particle diameter (volume average diameter) of the light-scattering particles in the ink composition can be 0.05 μm (50 nm) or more. It is 0.2 μm (200 nm) or more, or 0.3 μm (300 nm) or more. From the viewpoint of excellent ejection stability, the average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 1.0 μm (1000 nm) or less, 0.6 μm (600 nm) or less, or Below 0.4 μm (400 nm). The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition can be 0.05 μm to 1.0 μm, 0.05 μm to 0.6 μm, 0.05 μm to 0.4 μm, 0.2 μm to 1.0 μm, 0.2 μm to 0.6 μm, 0.2 μm～0.4 μm, 0.3 μm～1.0 μm, 0.3 μm～0.6 μm or 0.3 μm～0.4 μm. From the viewpoint of easily obtaining such an average particle diameter (volume average diameter), the average particle diameter (volume average diameter) of the light-scattering particles used may be 0.05 μm or more, and may be 1.0 μm or less. In this specification, the average particle diameter (volume average diameter) of the light-scattering particles in the ink composition is measured by a dynamic light scattering nanotorac particle size distribution meter, and the volume average diameter is calculated And get. In addition, the average particle diameter (volume average diameter) of the light-scattering particles used can be obtained, for example, by measuring the particle diameter of each particle with a transmission electron microscope or a scanning electron microscope, and calculating the volume average diameter.

From the viewpoint that the effect of improving external quantum efficiency is more excellent, the content of light-scattering particles in the ink composition is based on the total mass of the ink composition, for example, 0.1% by mass or more, or 1% by mass or more. 2% by mass or more. The content of the light-scattering particles is, for example, 60% by mass or less based on the total mass of the ink composition. From the viewpoint of excellent ejection stability and the viewpoint that the effect of improving external quantum efficiency is more excellent, the content of light-scattering particles is preferably 10% by mass or less, more preferably 7% by mass or less, and still more preferably 5% by mass or less . From these viewpoints, the content of the light-scattering particles is based on the total mass of the ink composition, and is preferably 0.1% by mass to 10% by mass.

From the viewpoint of excellent external quantum efficiency improvement effect, the mass ratio of the content of light-scattering particles to the content of luminescent nanocrystal grains (light-scattering particles/luminescent nanocrystal grains) can be 0.05 or more, It may be 0.1 or more, 0.2 or more, or 0.5 or more. From the viewpoint that the external quantum efficiency improvement effect is more excellent, and the continuous ejection property (ejection stability) during inkjet printing is excellent, the mass ratio (light-scattering particles/luminescent nano-grains) can be 5.0 or less. It is 2.0 or less, and may be 1.5 or less. From these viewpoints, the mass ratio (light-scattering particles/luminescent nanocrystal grains) may be, for example, 0.05 to 5.0.

[Polymer Dispersant] The polymer dispersant is a polymer compound having a weight average molecular weight of 750 or more and having a functional group having affinity for light-scattering particles. The polymer dispersant has a function of dispersing light-scattering particles. The polymer dispersant is adsorbed (for example, bonded) to the light-scattering particles via functional groups that have affinity for the light-scattering particles, and the light-scattering property is made light-scattering by the electrostatic repulsion and/or steric repulsion of the polymer dispersants. The particles are dispersed in the ink composition. The polymer dispersant is preferably bonded to the surface of the light-scattering particles to be adsorbed to the light-scattering particles, but may also be bonded to the surface of the light-emitting nanocrystal particles to be adsorbed to the light-emitting nanocrystal particles, or Free in the ink composition.

Examples of the functional group having affinity for light-scattering particles include an acidic functional group, a basic functional group, and a nonionic functional group. Acidic functional groups have dissociative protons, which can be neutralized by bases such as amines and hydroxide ions, and basic functional groups can also be neutralized by acids such as organic acids and inorganic acids.

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), etc.

Examples of 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.

Examples of nonionic functional groups include hydroxyl groups, ether groups, thioether groups, sulfinyl groups (-SO-), sulfinyl groups (-SO ₂ -), carbonyl groups, methanoyl groups, ester groups, and carbonate groups. , Amide group, aminomethanyl group, urea group, thioamide group, thiourea group, sulfamoyl group, cyano group, alkenyl group, alkynyl group, phosphine oxide group, phosphine sulfide group.

The polymer dispersant can be a polymer of a single monomer (homopolymer) or a copolymer of multiple monomers (copolymer). Furthermore, the polymer dispersant may be any of random copolymers, block copolymers, or graft copolymers. Moreover, when the polymer dispersant is a graft copolymer, it may be a comb-shaped graft copolymer or a star-shaped graft copolymer. The polymer dispersant can be, for example, acrylic resin, polyester resin, polyurethane resin, polyamide resin, polyether, phenol resin, silicone resin, polyurea resin, amino resin, epoxy resin, poly Polyamines such as ethyleneimine and polyallylamine, polyimine, etc.

As a polymer dispersant, commercially available products can also be used. As a commercially available product, Ajisper PB series manufactured by Ajinomoto Fine-Techno Co., Ltd. and BYK manufactured DISPERBYK series and BYK-series, Efka series manufactured by BASF, etc.

[Other ingredients] The ink composition may further contain components other than the above-mentioned components within a range that does not hinder the effects of the present invention.

The ink composition may further contain a solvent, for example. Examples of solvents include cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether, propylene glycol monomethyl ether acetate, butyl carbitol ethyl Acid ester, or a mixture of these, etc. Among them, in the ink composition of the present embodiment, the photopolymerizable compound also functions as a dispersing medium, so it is possible to disperse light-scattering particles and luminescent nanocrystal particles without a solvent. In this case, there is an advantage that there is no need to remove the solvent by drying when forming the pixel portion. When the ink composition includes a solvent, the content of the solvent is based on the total mass of the ink composition (including the solvent), and may be more than 0% by mass and 5% by mass or less.

The viscosity of the ink composition described above may be 2 mPa·s or more, 5 mPa·s or more, or 7 mPa·s or more from the viewpoint of ejection stability during inkjet printing, for example. The viscosity of the ink composition may be 20 mPa·s or less, 15 mPa·s or less, or 12 mPa·s or less. The viscosity of the ink composition may be, for example, 2 mPa·s to 20 mPa·s, 2 mPa·s to 15 mPa·s, 2 mPa·s to 12 mPa·s, 5 mPa·s to 20 mPa·s, 5 mPa·s～15 mPa·s, 5 mPa·s～12 mPa·s, 7 mPa·s～20 mPa·s, 7 mPa·s～15 mPa·s or 7 mPa·s～12 mPa·s. In addition, the viscosity is, for example, the viscosity at the ink temperature when inkjet printing is performed, and is the viscosity measured with an E-type viscometer. The ink temperature when performing inkjet printing is preferably 25°C to 60°C, more preferably 30°C to 55°C, and still more preferably 30°C to 40°C. The ink temperature when performing inkjet printing is adjusted by the temperature of the inkjet head when performing inkjet printing.

When the viscosity of the ink composition at the ink temperature during inkjet printing is 2 mPa･s or more, the shape of the meniscus of the inkjet ink at the tip of the ink ejection hole of the nozzle is stable, so the ejection of the inkjet ink is controlled (e.g. Control of ejection amount and ejection timing) becomes easy. On the other hand, when the viscosity of the ink composition at the ink temperature during inkjet printing is 20 mPa･s or less, the inkjet ink can be ejected smoothly from the ink ejection hole.

The surface tension of the ink composition is preferably a surface tension suitable for an inkjet method, specifically, it is preferably in the range of 20 mN/m to 40 mN/m, more preferably 25 mN/m to 35 mN/m. By setting the surface tension in this range, ejection control (for example, control of ejection amount and ejection timing) becomes easy, and the occurrence of flight curvature can be suppressed. Furthermore, the flying curve means that when the ink composition is ejected from the ink ejection hole, the landing position of the ink composition is shifted by 30 μm or more from the target position. When the surface tension is 40 mN/m or less, the shape of the meniscus at the tip of the ink ejection hole is stable, so ejection control of the ink composition (for example, ejection amount and ejection timing control) becomes easy. On the other hand, when the surface tension is 20 mN/m or more, it is possible to prevent the inkjet ink from contaminating the periphery of the ink ejection orifice, thereby suppressing the occurrence of flying bows. In other words, there will be no cases where the ink composition is incorrectly landed on the pixel portion forming area that should be landed and the ink composition is insufficiently filled, or the ink composition is landed on the pixel portion that should be landed. The pixel portion adjacent to the forming area forms an area (or pixel portion), and the color reproducibility is reduced. In addition, the surface tension described in this specification refers to the surface tension measured at 23° C., and refers to the tension measured by the ring method (also referred to as the wheel and ring method).

When the ink composition of this embodiment is used as an ink composition for an inkjet method, it is preferably applied to inkjet recording of a piezoelectric jet (Piezojet) method based on a mechanical ejection mechanism using piezoelectric elements Device. In the piezoelectric ejection method, the ink composition will not be exposed to high temperature instantaneously every time it is ejected. Therefore, the luminescent nanocrystal grains are less likely to be deteriorated, and it is easier to obtain expected luminescence characteristics in the pixel portion (light conversion layer).

In the foregoing, one embodiment of the inkjet ink composition has been described, but the inkjet ink composition of the above-mentioned embodiment can also use the inkjet method, for example, the photolithography method. In this case, the ink composition contains alkali-soluble resin as the binder polymer.

In the case of using the ink composition by the photolithography method, first, the ink composition is coated on a substrate, and the ink composition is further dried to form a coating film. The coating film thus obtained is soluble in an alkali developer, and is patterned by treatment with an alkali developer. At this time, from the viewpoint of ease of processing of the waste liquid of the developer, etc., the aqueous solution occupies most of the alkaline developer, and therefore the coating film of the ink composition is treated with the aqueous solution. On the other hand, in the case of an ink composition using luminescent nanocrystal grains (quantum dots, etc.), the luminescent nanocrystal grains are unstable with respect to water, and the luminescence (such as fluorescence) is impaired by moisture. . Therefore, in this embodiment, an inkjet method that does not require treatment with an alkali developer (aqueous solution) is preferable.

In addition, even when the coating film of the ink composition is not processed by an alkali developer, when the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere. Therefore, the luminescence (such as fluorescence) of the luminescent nanocrystal grains (quantum dots, etc.) is impaired over time. From such a viewpoint, in this embodiment, the coating film of the ink composition is preferably alkali-insoluble. 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. The fact that the coating film of the ink composition is alkali-insoluble means that the dissolved amount of the coating film of the ink composition at 25°C relative to the 1% by mass aqueous potassium hydroxide solution is based on the total mass of the coating film of the ink composition. It is 30% by mass or less. The dissolved amount of the coating film of the ink composition is preferably 10% by mass or less, more preferably 3% by mass or less. Furthermore, the content that the ink composition is an ink composition capable of forming an alkali-insoluble coating film can be obtained by coating the ink composition on a substrate and then drying it at 80°C for 3 minutes. The dissolved amount of the coating film with a thickness of 1 μm was measured to confirm.

＜Method of manufacturing ink composition＞ The ink composition of the embodiment includes, for example, a step of mixing the constituent components of the ink composition. The method of manufacturing the ink composition may further include a step of performing a dispersion treatment of the mixture of the constituent components.

The manufacturing method of the ink composition includes, for example, a first step of preparing a dispersion of light-scattering particles containing light-scattering particles; and a second step of mixing the dispersion of light-scattering particles and luminescent nanocrystals. The dispersion of light-scattering particles may further contain a polymer dispersant. In this method, the dispersion of light-scattering particles may further contain a photopolymerizable compound and a hypophosphorous acid diester compound, and in the second step, a photopolymerizable compound and a hypophosphorous acid diester compound may be further mixed. According to the method, the light-scattering particles can be sufficiently dispersed. Therefore, the optical characteristics (for example, external quantum efficiency) of the pixel portion can be improved, and an ink composition having excellent ejection stability can be easily obtained.

In the step of preparing a dispersion of light-scattering particles, the light-scattering particles can be prepared by mixing the light-scattering particles, a polymer dispersant, a photopolymerizable compound, and a hypophosphorous acid diester compound as appropriate, and then dispersing them. Dispersion of particles. The mixing and dispersion treatment can be performed using a dispersion device such as a bead mill, a paint conditioner, a planetary mixer, and a jet mill. From the viewpoint that the dispersibility of the light-scattering particles becomes good and the average particle diameter of the light-scattering particles is easily adjusted to a desired range, it is preferable to use a bead mill or a paint conditioner. By mixing the light-scattering particles and the polymer dispersant before mixing the light-emitting nanocrystal particles and the light-scattering particles, the light-scattering particles can be more fully dispersed. Therefore, it is possible to further easily obtain excellent ejection stability and excellent external quantum efficiency.

The manufacturing method of the ink composition may further include a step of preparing a dispersion of the luminescent nanocrystal particles containing the luminescent nanocrystal particles and the photopolymerizable compound before the second step. In this case, in the second step, a dispersion of light-scattering particles and a dispersion of luminescent nanocrystal particles are mixed. In the step of preparing a dispersion of luminescent nanocrystals, the luminescent nanocrystals can be prepared by mixing the luminescent nanocrystals, a photopolymerizable compound, and optionally a hypophosphorous acid diester compound and performing a dispersion treatment. Rice grain dispersion. As the luminescent nanocrystal grains, a luminescent nanocrystal grain having an organic ligand on its surface can be used. That is, the luminescent nanocrystal particle dispersion may further contain an organic ligand. The mixing and dispersing treatment can use normal stirring devices such as electromagnetic stirrers, three-one motors, or dispersion devices such as vortex mixers, bead mills, paint regulators, planetary mixers, and jet mills. conduct. From the viewpoint of not applying excessive energy to the luminescent nanocrystal grains, it is preferable to use a normal stirring device such as an electromagnetic stirrer, a three-stage motor, or a vortex mixer. According to this method, it is possible to sufficiently disperse the luminescent nanocrystal grains without reducing the performance of the luminescent nanocrystal grains. Therefore, the optical characteristics (for example, external quantum efficiency) of the pixel portion can be improved, and an ink composition having excellent ejection stability can be easily obtained.

＜Ink composition group＞ The ink composition set of one embodiment includes the ink composition of the above-mentioned embodiment. In addition to the ink composition (luminescent ink composition) of the aforementioned embodiment, the ink composition set may also include an ink composition (non-luminescent ink composition) that does not contain luminescent nanocrystal particles. The non-luminescent ink composition is, for example, a curable ink composition. The non-luminescent ink composition may be a previously known ink composition, and may have the same composition as the ink composition (luminescent ink composition) of the above-mentioned embodiment, except that it does not contain luminescent nanocrystal grains.

The non-luminescent ink composition does not contain luminescent nano crystal grains, so light is incident on the pixel portion formed of the non-luminescent ink composition (the pixel portion of the cured product of the non-luminescent ink composition). In this case, the light emitted from the pixel portion has approximately the same wavelength as the incident light. Therefore, the non-luminescent ink composition can be preferably used to form a pixel portion of the same color as the light from the light source. For example, when the light from the light source is light (blue light) having a wavelength in the range of 420 nm to 480 nm, the pixel portion formed of the non-luminescent ink composition may become the blue pixel portion.

The non-luminescent ink composition preferably contains light-scattering particles. When the non-luminescent ink composition contains light-scattering particles, the pixel portion formed of the non-luminescent ink composition can scatter light incident on the pixel portion, thereby reducing the emission from the pixel portion. The light intensity difference in the angle of view of the emitted light.

＜Light conversion layer and color filter＞ Hereinafter, the details of the light conversion layer and the color filter obtained by using the ink composition set of the above-mentioned embodiment will be described with reference to the drawings. In addition, in the following description, the same reference numerals are used for the same or equivalent elements, and repeated descriptions are omitted.

Fig. 1 is a schematic cross-sectional view of a color filter according to an embodiment. As shown in FIG. 1, the color filter 100 includes 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 light shielding portions 20.

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

Each of the first pixel portion 10a and the second pixel portion 10b is a light-emitting pixel portion (light-emitting pixel portion) including a cured product of the ink composition of the above-mentioned embodiment. The first pixel portion 10a includes a first hardening component 13a, and first light-emitting nanocrystal grains 11a and first light-scattering particles 12a dispersed in the first hardening component 13a, respectively. Similarly, the second pixel portion 10b includes a second hardening component 13b, and second light-emitting nanocrystal grains 11b and second light scattering particles 12b dispersed in the second hardening component 13b, respectively. The curing component is a component obtained by polymerization of a photopolymerizable compound, and includes a polymer of the photopolymerizable compound and a hypophosphorous acid diester compound. In addition to the polymer and the hypophosphorous acid diester compound, the curing component may also contain organic components (organic ligands, polymer dispersants, unreacted polymerizable compounds, etc.) contained in the ink composition. In the first pixel portion 10a and the second pixel portion 10b, the first hardening component 13a and the second hardening component 13b may be the same or different, and the first light-scattering particles 12a and the second light-scattering particles 12b may be the same Can be different.

The first luminescent nanocrystal grain 11a is a red luminescent nanocrystal particle that absorbs light having a wavelength in the range of 420 nm to 480 nm and emits light having an emission peak wavelength in the range of 605 nm to 665 nm. That is, the first pixel portion 10a may also be referred to as a red pixel portion for converting blue light into red light. In addition, the second luminescent nanocrystal grain 11b is a green luminescent nanocrystal grain that absorbs light having a wavelength in the range of 420 nm to 480 nm and emits light having an emission peak wavelength in the range of 500 nm to 560 nm. That is, the second pixel portion 10b may also be referred to as a green pixel portion for converting blue light into green light.

From the viewpoint of a more excellent effect of improving external quantum efficiency and the viewpoint of obtaining excellent luminous intensity, the content of the luminescent nanocrystal grains in the luminescent pixel portion is based on the total mass of the cured product of the luminescent ink composition The standard is preferably 20% by mass or more, and may be 22% by mass or more, 24% by mass or more, or 26% by mass or more. From the viewpoint of the reliability of the pixel portion and the viewpoint of obtaining excellent luminous intensity, the content of the luminescent nanocrystal grains is based on the total mass of the cured product of the luminescent ink composition, and is preferably 80% by mass Below, it may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less.

From the viewpoint that the effect of improving the external quantum efficiency is more excellent, the content of the light-scattering particles in the luminescent pixel portion is based on the total mass of the cured product of the luminescent ink composition, and is, for example, 0.1% by mass or more. It may be 1% by mass or more or 2% by mass or more. The content of the light-scattering particles is based on the total mass of the cured product of the luminescent ink composition, and is, for example, 60% by mass or less. From the viewpoint that the effect of improving the external quantum efficiency is more excellent and the viewpoint that the reliability of the pixel portion is excellent, the content of the light-scattering particles is based on the total mass of the cured product of the luminescent ink composition, and is preferably 10 mass % Or less, more preferably 7 mass% or less, and still more preferably 5 mass% or less.

The third pixel portion 10c is a non-luminescent pixel portion (non-luminescent pixel portion) including a cured product of the non-luminescent ink composition. The hardened product does not contain luminescent nano grains, but contains light-scattering particles and hardening components. That is, the third pixel portion 10c includes the third hardening component 13c and the third light-scattering particles 12c dispersed in the third hardening component 13c. The third curing component 13c is, for example, a component obtained by polymerization of a polymerizable compound, and includes a polymer of the polymerizable compound. The third light-scattering particle 12c, the first light-scattering particle 12a, and the second light-scattering particle 12b may be the same or different.

The third pixel portion 10c has a transmittance of 30% or more with respect to light having a wavelength in the range of 420 nm to 480 nm, for example. Therefore, the third pixel portion 10c functions as a blue pixel portion when a light source that emits light with a wavelength in the range of 420 nm to 480 nm is used. Furthermore, the transmittance of the third pixel portion 10c can be measured by a microscopic light device.

From the viewpoint of further reducing the light intensity difference in the angle of view, the content of the light-scattering particles in the non-luminescent pixel portion may be 1 based on the total mass of the cured product of the non-luminescent ink composition The mass% or more may be 5 mass% or more, or it may be 10 mass% or more. From the viewpoint of further reducing light reflection, the content of light-scattering particles is based on the total mass of the cured product of the non-luminescent ink composition, and may be 50% by mass or less, 30% by mass or less, or 20% 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) may be, for example, 1 μm or more, 2 μm or more, or 3 μm or more. The thickness of the pixel portion (the first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c) may be, for example, 30 μm or less, 20 μm or less, or 15 μm or less.

The light shielding portion 20 is a so-called black matrix provided for the purpose of separating adjacent pixel portions to prevent color mixing and for preventing light leakage from the light source. The material constituting the light-shielding portion 20 is not particularly limited. In addition to metals such as chromium, a cured resin composition containing light-shielding particles such as carbon particles, metal oxides, inorganic pigments, and organic pigments in the binder polymer can also be used. . As the binder polymer used here, one or two types of resins such as polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, and cellulose can be used. Those mixed with the above, photosensitive resin, oil-in-water (O/W) emulsion (emulsion) type resin composition (for example, one obtained by emulsifying reactive silicone), etc. The thickness of the light shielding portion 20 may be 0.5 μm or more, and may be 10 μm or less, for example.

The substrate 40 is a transparent substrate with light transmittance. For example, transparent glass substrates such as quartz glass, Pyrex (registered trademark) glass, synthetic quartz plates, transparent resin films, optical resin films, etc. can be used. The flexible substrate and so on. Among these, it is preferable to use a glass substrate including an alkali-free glass that does not contain an alkali component in the glass. Specifically, "7059 glass", "1737 glass", "EAGLE 200" and "Yigle XG (EAGLE XG)" manufactured by Corning Corporation, and "Eagle XG" manufactured by Asahi Glass AN100", "OA-10G" and "OA-11" manufactured by Nippon Electric Glass Co., Ltd. These are materials with a low thermal expansion coefficient, and are excellent in dimensional stability and workability in high-temperature heat treatment.

The color filter 100 provided with the light conversion layer 30 described above can be preferably used when a light source that emits light with a wavelength in the range of 420 nm to 480 nm is used.

The color filter 100 can be manufactured by, for example, forming the light-shielding portion 20 on the substrate 40 in a pattern shape, and then forming the pixel portion 10 in the pixel portion formation region divided by the light-shielding portion 20 on the substrate 40. The pixel portion 10 can be formed by a method including the steps of selectively attaching an ink composition (inkjet ink) to the pixel portion forming area on the substrate 40 by an inkjet method; The step of removing the organic solvent from the ink composition by drying; and the step of irradiating the dried ink composition with active energy rays (for example, ultraviolet rays) to harden the ink composition to obtain a light-emitting pixel portion. The luminescent pixel portion is obtained by using the luminescent ink composition as the ink composition, and the non-luminescent pixel portion is obtained by using the non-luminescent ink composition.

The method of forming the light-shielding portion 20 includes forming a thin film of a metal film such as chromium or a resin composition containing light-shielding particles in an area on one surface side of the substrate 40 that becomes the boundary between a plurality of pixel portions, and applying the film Patterning method, etc. The metal thin film can be formed by, for example, a sputtering method, a vacuum vapor deposition method, or the like, and a thin film of a resin composition containing light-shielding particles can be formed by methods such as coating and printing. As a method of patterning, photolithography and the like can be cited.

Examples of the inkjet method include a Bubble Jet (registered trademark) method using an electrothermal converter as an energy generating element, or a piezoelectric jet method using a piezoelectric element.

In the drying of the ink composition, it is sufficient to remove at least a part of the organic solvent, and it is preferable to remove all of the organic solvent. The drying method of the ink composition is preferably drying by reduced pressure (reduced pressure drying). From the viewpoint of controlling the composition of the ink composition, the reduced-pressure drying is usually performed at a pressure of 1.0 Pa to 500 Pa at 20°C to 30°C for 3 to 30 minutes.

For curing of the ink composition, for example, a mercury lamp, a metal halide lamp, a xenon lamp, a light emitting diode (Light Emitting Diode, LED), etc. can be used. The wavelength of the irradiated light may be 200 nm or more, and may be 440 nm or less, for example. The exposure amount can be 10 mJ/cm ² or more, and can be 20000 mJ/cm ² or less, for example.

As mentioned above, although one embodiment of the color filter, the light conversion layer, and the manufacturing method of these was demonstrated, this invention is not limited to the said embodiment.

For example, instead of the third pixel portion 10c or in addition to the third pixel portion 10c, the light conversion layer may also include: pixels containing a cured product of a luminescent ink composition containing blue luminescent nanocrystal grains Department (blue pixel department). In addition, the light conversion layer may include a pixel portion (for example, a yellow pixel portion) containing a cured product of a luminescent ink composition containing nanocrystal particles that emit light of colors other than red, green, and blue. In these cases, it is preferable that the luminescent nanocrystal grains contained in each pixel portion of the light conversion layer each have an absorption maximum wavelength in the same wavelength region.

In addition, at least a part of the pixel portion of the light conversion layer may include a cured product of a composition containing a pigment other than the luminescent nanocrystal grains.

In addition, the color filter may include an ink-repellent layer containing a material having ink repellency and having a width smaller than that of the light-shielding portion on the pattern of the light-shielding portion. Moreover, instead of providing the ink repellent layer, a photocatalyst-containing layer as a variable wettability layer may be formed as a coating on the entire surface of the area including the pixel portion formation area, and then the photocatalyst-containing layer may be contained through a photomask. The layer is exposed with light to selectively increase the ink affinity of the region where the pixel portion is formed. As a photocatalyst, titanium oxide, zinc oxide, etc. are mentioned.

In addition, the color filter may include an ink receiving layer containing hydroxypropyl cellulose, polyvinyl alcohol, gelatin, etc., between the substrate and the pixel portion.

In addition, the color filter may include a protective layer on the pixel portion. The protective layer is provided to flatten the color filter and prevent the components contained in the pixel portion or the components contained in the pixel portion and the components contained in the photocatalyst-containing layer from eluting into the liquid crystal layer. The material constituting the protective layer can be used as a well-known protective layer for color filters.

In addition, in the manufacture of the color filter and the light conversion layer, instead of the inkjet method, the photolithography method may be used to form the pixel portion. At this time, first, the ink composition is applied in a layered form on the substrate to form an ink composition layer. Then, after exposing the ink composition layer in a pattern shape, it develops using a developing solution. In this way, a pixel portion including a cured product of the ink composition is formed. The developer is usually alkaline, so an alkali-soluble material is used as the material of the ink composition. However, from the viewpoint of material efficiency, the inkjet method is superior to the photolithography method. This is because in the photolithography method, in terms of its principle, more than 2/3 of the material has to be removed, and the material will be wasted. Therefore, in this embodiment, it is preferable to use inkjet ink to form the pixel portion by the inkjet method.

In addition to the above-mentioned luminescent nanocrystal grains, the pixel portion of the light conversion layer of the present embodiment may further contain a pigment of substantially the same color as the luminescent color of the luminescent nanocrystal grains. In order for the pixel portion to contain a pigment, the ink composition may contain a pigment.

In addition, one or two of the red pixel portion (R), the green pixel portion (G), and the blue pixel portion (B) in the light conversion layer of this embodiment may be used It is formed as a pixel portion that does not contain luminescent nanocrystal grains but contains color materials. As the color material that can be used here, known color materials can be used. For example, as the color material used for the red pixel portion (R), diketopyrrolopyrrole pigments and/or anionic red organic dyes can be cited. The color material used in the green pixel portion (G) includes a group selected from the group consisting of halogenated copper phthalocyanine pigments, phthalocyanine-based green dyes, phthalocyanine-based blue dyes, and azo-based yellow organic dyes. At least one of them. Examples of the color material used for the blue pixel portion (B) include ε-type copper phthalocyanine pigments and/or cationic blue organic dyes. Regarding the amount of use of these color materials, when contained in the light conversion layer, from the viewpoint of preventing a decrease in transmittance, based on the total mass of the pixel portion (cured material of the ink composition), it is preferably 1% to 5% by mass.

In addition, the color filter may include a normal color filter layer that does not include the light-emitting nanocrystal grains but includes the color material between the substrate and the pixel portion of the present embodiment. That is, the color filter of this embodiment may include a substrate, a color filter layer that does not contain luminescent nanoparticles but a color material provided on the substrate, and a color filter layer provided on the color filter layer. The pixel part of this embodiment. [Example]

Hereinafter, the present invention will be described in detail with examples. However, the present invention is not limited to the following examples. In addition, all the materials used in the examples were obtained by introducing argon gas and replacing dissolved oxygen with argon gas. Regarding titanium oxide, before mixing, under a reduced pressure of 1 mmHg, heating at 175°C for 4 hours, and cooling in an argon atmosphere. The liquid material used in the examples was used after dehydration with molecular sieve 3A for 48 hours or more before mixing.

＜Preparation of photopolymerizable compound＞ The photopolymerizable compound shown below was prepared. ·PhEM (phenoxyethyl methacrylate, product name: Light Ester PO, manufactured by Kyoeisha Chemical Co., Ltd.) ·LM (Lauryl methacrylate, product name: Light Ester L, manufactured by Kyoeisha Chemical Co., Ltd.) ·HDM (1,6-hexanediol dimethacrylate, product name: Light Ester 1.6HX, manufactured by Kyoeisha Chemical Co., Ltd.) ·TMPT (Trimethylolpropane triacrylate, product name: VISCOAT #295, manufactured by Osaka Organic Chemical Industry Co., Ltd.)

＜Preparation of hypophosphorous acid diester compound＞ As the hypophosphorous acid diester compound, compound 1 (hypophosphorous acid diester compound 1) and compound 2 (hypophosphorous acid diester compound 2) shown below were prepared. Compound 1 was synthesized by the method described below. For compound 2, GSY-P101 (manufactured by Jing Chemical Industry Co., Ltd., product name) was used.

[化12]

[Synthesis of Compound 1] Put 10 g of biphenyl, 53.4 g of phosphorus trichloride, and 21.6 g of anhydrous aluminum chloride into a 500 mL flask, and react under reflux for 6 hours. The unreacted phosphorus trichloride vapor was removed, 24.8 g of phosphorus chloride and 70 mL of toluene were added, and reacted at 80° C. for 1 hour to obtain Intermediate 1 as shown below.

[化13]

Then, the toluene solution containing Intermediate 1 was heated at 90°C, and a mixed solution of 54.8 g of 4-di-tert-butylphenol, 2.2 g of triethylamine, and 50 mL of toluene was added dropwise over 30 minutes, and then stirred for 120 minutes . After the completion of the reaction, the product was filtered and cooled immediately to crystallize the product, and after centrifugal separation and recovery, it was washed with methanol to obtain compound 1.

＜Preparation of Quantum Dot (QD) particles (QD powder) with organic ligands＞ [Synthesis of Organic Ligand 1] Put polyethylene glycol |average Mn350| (|average Mn350|) (manufactured by Sigma-Aldrich) into the flask, and add polyethylene glycol to it while stirring in a nitrogen atmosphere. average Mn350|Equal molar amount of succinic anhydride (manufactured by Sigma-Aldrich). The internal temperature of the flask was raised to 80°C and stirred for 8 hours to obtain the organic ligand 1 represented by the following formula (A) as a pale yellow viscous oily substance.

[化14]

[Production of QD powder by ligand exchange] To Nanosys (Nanosys) InP nano crystal dispersion (InP QD in Heptane Red InP QD (InP QD in Heptane Red InP QD), QD particles (luminescent nano grains) concentration is 30% , Organic ligand: oleic acid), add 2.0 times the amount of PGMEA and 40% by mass of QD particles (excluding the amount of organic ligands) of organic ligand 1, and stir at 80°C for 1 Hours for ligand exchange. The QD particles were aggregated by adding four times the amount of heptane to the solution and precipitated by centrifugal separation, and then the QD particles were separated by decantation of the supernatant. The obtained QD particles were dried by a vacuum dryer to obtain QD powder 1 (QD particles/organic ligand=75% by mass/25% by mass).

<Preparation of light-scattering particle dispersion> In a container filled with argon, 5.23 g of titanium oxide (product name: CR-60-2, manufactured by Ishihara Industry Co., Ltd., average particle size (volume average diameter): 210 nm), 0.27 g of polymer dispersant ( After mixing Ajisper PB-821, manufactured by Ajinomoto Fine Techno Co., Ltd., and 4.5 g of LM, add zirconia beads (diameter: 1.25 mm) to the obtained mixture, and use paint The conditioner was oscillated for 2 hours, thereby dispersing the mixture, and removing the zirconia beads with a polyester mesh filter to obtain a light-scattering particle dispersion 1 (titanium oxide content: 55% by mass).

Except for changing the LM to HDM, the light-scattering particle dispersion 2 was obtained in the same manner as described above.

＜Preparation of ink composition＞ (Example 1) 1.75 g of InP nanocrystal dispersion (QD particles/organic ligand=75% by mass/25% by mass) manufactured by Nanosys and dried by a vacuum dryer, 0.27 g of light-scattering particles dispersed Body 1, 0.15 g photopolymerization initiator (phenyl(2,4,6-trimethylbenzyl)-diphenyl-phosphine oxide, manufactured by IGM resin company, product name: Omile Germany (Omnirad) TPO), 2.78 g of photopolymerizable component A (LM:TMPT=84:16 (mass ratio)) and 0.05 g of hypophosphorous acid diester compound 1, after uniformly mixing in a container filled with argon, put it on the glove In the box, the mixture is filtered with a filter with a pore size of 5 μm. Furthermore, argon gas was introduced into the container in which the obtained filtrate was put, and the inside of the container was saturated with argon gas. Then, the pressure was reduced to remove the argon gas, thereby obtaining the ink composition of Example 1 (inkjet ink). The content of luminescent nanocrystal grains (amount not including organic ligands) was 26.3% by mass. The content of LM is 49.3% by mass. The content of TMPT is 8.7% by mass. The content of the photopolymerization initiator is 3.0% by mass. The content of hypophosphorous acid diester compound 1 is 1.0% by mass. The content of light-scattering particles is 2.8% by mass. The content of the polymer dispersant is 0.2% by mass. In addition, the content is based on the total mass of the ink composition.

(Example 2) Except that hypophosphorous acid diester compound 2 was used instead of hypophosphorous acid diester compound 1, an ink composition was obtained in the same manner as in Example 1.

(Example 3) 1.75g QD powder 1, 0.27g light-scattering particle dispersion 2, 0.15g photopolymerization initiator (phenyl(2,4,6-trimethylbenzyl)-diphenyl-phosphine oxide) , IGM resin (IGM resin) company manufacture, product name: Omnirad (Omnirad) TPO), 2.78 g photopolymerizable component B (PhEM:LM:HDM=47:21:32 (mass ratio)) and 0.05 g After the hypophosphorous acid diester compound 1 was uniformly mixed in a container filled with argon gas, the mixture was filtered with a filter with a pore size of 5 μm in a glove box. Furthermore, argon gas was introduced into the container in which the obtained filtrate was put, and the inside of the container was saturated with argon gas. Then, the pressure was reduced to remove the argon gas, thereby obtaining the ink composition (inkjet ink) of Example 3.

(Example 4) Except that hypophosphorous acid diester compound 2 was used instead of hypophosphorous acid diester compound 1, an ink composition was obtained in the same manner as in Example 3.

(Example 5) The blending amount of the photopolymerizable component B was changed to 2.73 g, and as the blending component, 0.05 g of Adekastab AO-30 (1,1,3- Tris-(2'-methyl-4'-hydroxy-5'-tertiary butylphenyl)butane, manufactured by ADEKA Co., Ltd., product name), in addition to the examples 3 In the same way, an ink composition was obtained.

(Example 6) Using Adekastab AO-80 (3,9-bis[2-[3-(tert-butyl-4-hydroxy-5-methylphenyl)propane) as a semi-hindered phenol antioxidant Alkyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, manufactured by ADEKA Co., Ltd. (product name) instead Except for Adekastab AO-30, an ink composition was obtained in the same manner as in Example 5.

(Example 7) Uses Adekastab AO-50 (octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) as a hindered phenol-based antioxidant. Co., Ltd. Except that Adekastab AO-30 was replaced by Adekastab AO-30, manufactured by ADEKA (product name), an ink composition was obtained in the same manner as in Example 5.

(Example 8) Using Adekastab AO-60 (pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, Co., Ltd.) as a hindered phenol-based antioxidant Except that Adekastab AO-30 was replaced with Adekastab AO-30, an ink composition was obtained in the same manner as in Example 5.

(Comparative example 1) Use Irgafos 168 (tris(2,4-di-tert-butylphenyl) phosphite, manufactured by BASF) instead of hypophosphorous acid diester compound 1, in addition to In Example 1, an ink composition was obtained in the same manner.

(Comparative example 2) Except for using triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) instead of the hypophosphorous acid diester compound 1, an ink composition was obtained in the same manner as in Example 1.

<Evaluation of ink physical properties> The stability of the viscosity of the ink compositions of the examples and comparative examples was evaluated by the following method. The viscosity of the ink composition immediately after preparation was compared with the viscosity of the ink composition stored in a constant temperature bath at 40° C. for 1 week after preparation, and the rate of increase in viscosity was calculated. Specifically, the viscosity of the ink composition immediately after preparation is set to η ₀ , and the viscosity of the ink composition stored in a thermostat at 40° C. for 1 week after preparation is set to η ₁ , and it is calculated by the following formula. Viscosity rise rate=(η ₁ -η ₀ )/η ₀ ×100 (%) Furthermore, the viscosity is the viscosity at 40°C and is measured with an E-type viscometer.

<Evaluation of coating film properties> The ink composition was coated on the glass substrate with a spin coater in the air so that the film thickness became 15 μm. In a nitrogen atmosphere, a UV irradiation device using an LED lamp with a dominant wavelength of 395 nm is used to irradiate the coated film with ^{UV so that the cumulative light quantity reaches 10000 mJ/cm 2} to harden the glove. The box was heated at 180°C for 30 minutes to form a layer (light conversion layer) containing a cured product of the ink composition on the glass substrate. In this way, a sample for evaluation was obtained.

(Evaluation of surface uniformity) The surface roughness (Sa value) of the hardened surface was measured using Vert Scan 3.0 R4300 of the rhombohedral system.

＜Evaluation of external quantum efficiency (EQE)＞ As the surface light source, a blue LED (peak emission wavelength: 450 nm) manufactured by CCS Co., Ltd. was used. The measuring device is a radiation spectrophotometer manufactured by Otsuka Electronics Co., Ltd. (product name "MCPD-9800") connected to an integrating sphere, and an integrating sphere is installed on the upper side of the blue LED. The prepared 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.

Based on the spectrum and illuminance measured by the measuring device, the external quantum efficiency is determined as follows. The external quantum efficiency is a value indicating what proportion of the light (photons) incident on the light conversion layer is radiated to the observer side as fluorescent light. Therefore, the larger the value, the better the light-emitting characteristics of the light conversion layer, which is an important evaluation index. EQE(%)=[P1(Red)]/E(Blue)×100

Here, E (blue) and P1 (red) respectively indicate the following. E (blue): Represents the total value of "illuminance × wavelength ÷ hc" in the wavelength region of 380 nm to 490 nm. P1 (red): Represents the total value of "illuminance × wavelength ÷ hc" in the wavelength region of 590 nm to 780 nm. These are values equivalent to the number of observed photons. Furthermore, h represents Planck's constant, and c represents the speed of light.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative example 1 Comparative example 2 Additives (mass%) Compound 1 1.0 1.0 1.0 1.0 1.0 1.0 Compound 2 1.0 1.0 Irgafos (Irgafos) 168 1.0 Triphenylphosphine 1.0 AO-30 1.0 AO-80 1.0 AO-50 1.0 AO-60 1.0 Photopolymerizable component (mass%) PhEM 26.1 26.1 25.7 25.7 25.7 25.7 LM 49.3 49.3 11.6 11.6 11.4 11.4 11.4 11.4 49.3 49.3 HDM 20.3 20.3 20.0 20.0 20.0 20.0 TMPT 8.7 8.7 8.7 8.7 EQE (%) 32 31 33 33 37 37 38 39 28 28 Surface roughness (μm) ＞1 ＞1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＞1 ＞1 Viscosity rise rate 0% 0% 0% 0% 0% 0% 0% 0% 2% 10% (Note) The content (unit: mass %) of each component shown in Table 1 is based on the total mass of the ink composition.

10: Pixel Department 10a: The first pixel part 10b: The second pixel part 10c: The third pixel part 11a: The first luminescent nanocrystalline grain 11b: Second luminescent nanocrystalline grain 12a: The first light-scattering particle 12b: Second light scattering particles 12c: third light scattering particle 13a: The first hardening component 13b: Second hardening component 13c: The third hardening component 20: Shading part 30: Light conversion layer 40: Substrate 100: Color filter

Fig. 1 is a schematic cross-sectional view of a color filter according to an embodiment of the present invention.

none.

Claims (15)

An ink composition for forming a light conversion layer, and the ink composition includes: Luminous nanocrystalline grains, photopolymerizable compounds, and hypophosphorous acid diester compounds. The ink composition according to claim 1, wherein the hypophosphorous acid diester compound is a compound represented by the following formula (II),

In formula (II), X ¹ represents an oxygen atom or a sulfur atom, R ¹ represents a hydrogen atom or an organic group, wherein the atom directly bonded to P is a carbon atom, Ar ¹ represents an aryl group, and two X ^1s may be the same as each other They may be different, and the two Ar ¹ may be the same or different from each other. The ink composition according to claim 1 or 2, wherein the hypophosphorous acid diester compound is a compound represented by the following formula (IV),

In formula (IV), Y represents a linking group, X ² and X ³ represent an oxygen atom or a sulfur atom, Ar ² and Ar ³ represent an aryl group, two X ² may be the same or different, and two X ³ may be the same. The two Ar ² may be the same or different from ^{each other, and the two Ar 3} may be the same or different from each other. The ink composition according to any one of claims 1 to 3, wherein the content of the luminescent nanocrystal particles is 20% by mass or more based on the total mass of the ink composition. The ink composition according to any one of claims 1 to 4, wherein the content of the hypophosphorous acid diester compound is 0.01% by mass to 10% by mass. The ink composition according to any one of claims 1 to 5, wherein the photopolymerizable compound includes a radical polymerizable compound having a cyclic structure and a linear structure having a carbon number of 4 or more The radically polymerizable compound. The ink composition according to any one of claims 1 to 6, which further contains a phenolic antioxidant. The ink composition according to claim 7, wherein the phenol-based antioxidant is a hindered phenol-based antioxidant. The ink composition according to any one of claims 1 to 8, which further contains light-scattering particles. The ink composition according to claim 9, which further contains a polymer dispersant. The ink composition according to any one of claims 1 to 10, which is used in an inkjet method. A light conversion layer includes a plurality of pixel portions and a light shielding portion arranged between the plurality of pixel portions, The plurality of pixel portions include a light-emitting pixel portion including the cured product of the ink composition according to any one of claim 1 to claim 11. The light conversion layer according to claim 12, which includes a first light-emitting pixel portion and a second light-emitting pixel portion as the light-emitting pixel portion, The first luminescent pixel portion contains luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 nm to 480 nm and emit light having an emission peak wavelength in the range of 605 nm to 665 nm; and The second luminescent pixel portion contains luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 nm to 480 nm and emit light having a light emission peak wavelength in the range of 500 nm to 560 nm. The light conversion layer according to claim 12 or claim 13, which further includes a non-luminous pixel portion containing light-scattering particles. A color filter, comprising the light conversion layer according to any one of claim 12 to 14.

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