KR102632511B1 - Inkjet ink, light conversion layer, and color filter for color filters - Google Patents

Abstract

One aspect of the present invention is an inkjet ink for a color filter containing luminescent nanocrystal particles, a photopolymerizable compound and/or thermosetting resin, and light scattering particles, wherein the luminescent nanocrystal particles have an organic ligand on their surface, The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles is 41% by mass or more, based on the total mass of the inkjet ink, and the total content of luminescent nanocrystal particles and organic ligands The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles is 21 parts by mass or more, and the content of organic ligands is 21 parts by mass or more of the luminescent nanocrystal particles and organic ligands. It relates to an inkjet ink for a color filter in which the total content is 20 parts by mass or more and the weight average molecular weight of the organic ligand is 1000 or less.

Description

Inkjet ink, light conversion layer, and color filter for color filters

The present invention relates to inkjet ink for color filters, light conversion layers, and color filters.

Conventionally, the pixel portion (color filter pixel portion) in a display such as a liquid crystal display device is a curable resist material containing, for example, red organic pigment particles or green organic pigment particles and an alkali-soluble resin and/or an acrylic monomer. It has been manufactured using a photolithography method.

In recent years, there has been a strong demand for lower power consumption of displays, and instead of the red organic pigment particles or green organic pigment particles, luminescent nanocrystal particles such as quantum dots, quantum rods, and other inorganic phosphor particles are used, Methods for forming pixel parts such as red pixels and green pixels are being actively studied.

However, the method of manufacturing a color filter using the photolithography method has a drawback in that resist materials other than the pixel portion containing relatively expensive luminescent nanocrystal particles are wasted due to the characteristics of the manufacturing method. Under these circumstances, in order to eliminate the waste of resist material as described above, forming a photo-conversion substrate pixel portion by an inkjet method is beginning to be examined (Patent Document 1).

International Patent Publication No. 2008/001693

In the inkjet ink containing luminescent nanocrystal particles, the luminescent nanocrystal particles (and the organic matter imparted to the surface thereof) are used in terms of improving the optical properties of the pixel portion (for example, improving external quantum efficiency (EQE)). It is desirable to increase the content of (ligand). In addition, it is necessary to increase the film thickness of the pixel portion, but in order to form the pixel portion by the inkjet method, it is desirable to increase the content of non-volatile matter in the inkjet ink. That is, when the content of non-volatile components in the inkjet ink is low (for example, 40% by mass or less based on the total mass of the inkjet ink), after printing the ink on the pixel portion, the volatile components volatilize and the film thickness decreases. Because it becomes thin, multiple printings are required, and production efficiency by inkjet may significantly decrease. However, according to the present inventors' examination, the content of luminescent nanocrystal particles (and organic ligands imparted to their surfaces) is high (e.g., 21 parts by mass or more with respect to 100 parts by mass of non-volatile matter of inkjet ink), and In inkjet ink with a high content of non-volatile matter (e.g., 41% by mass or more based on the total mass of the inkjet ink), the viscosity tends to be high, so there is a problem that it is difficult to secure an appropriate viscosity for forming the pixel portion. In addition, it was found that there is a risk that the viscosity may increase (increase) in the atmospheric atmosphere.

Therefore, the present invention is an inkjet ink that contains luminescent nanocrystal particles and has a high content of non-volatile matter, has a viscosity appropriate for forming a pixel portion, and is capable of suppressing thickening in an atmospheric environment for a color filter. The purpose is to provide inkjet ink, and a light conversion layer and color filter using the inkjet ink.

One aspect of the present invention is an inkjet ink for a color filter containing luminescent nanocrystal particles, a photopolymerizable compound and/or thermosetting resin, and light scattering particles, wherein the luminescent nanocrystal particles have an organic ligand on their surface, The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles is 41% by mass or more, based on the total mass of the inkjet ink, and the total content of luminescent nanocrystal particles and organic ligands The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles is 21 parts by mass or more, and the content of organic ligands is 21 parts by mass or more of the luminescent nanocrystal particles and organic ligands. It relates to an inkjet ink for a color filter in which the total content is 20 parts by mass or more and the weight average molecular weight of the organic ligand is 1000 or less.

Since the inkjet ink for a color filter of the present invention adopts the above configuration, it contains luminescent nanocrystal particles, and further contains luminescent nanocrystal particles, an organic ligand, a photopolymerizable compound, a thermosetting resin, and light scattering particles (hereinafter, It is an inkjet ink with a high total content of "non-volatile matter" (these components are collectively referred to as "non-volatile matter"), has a viscosity appropriate for forming a pixel portion, and can suppress thickening in the atmospheric environment.

In the above inkjet ink, the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles may be 70% by mass or more based on the total mass of the inkjet ink.

In the above inkjet ink, the organic ligand may contain a polyoxyalkylene group.

Another aspect of the present invention includes a plurality of pixel portions and a light-shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions have a light-emitting pixel portion containing a cured product of the inkjet ink for a color filter described above. , relates to the light conversion layer.

The light conversion layer is the light-emitting pixel portion, and contains light-emitting nanocrystal particles that absorb light with a wavelength in the range of 420 to 480 nm and emit light with an emission peak wavelength in the range of 605 to 665 nm. A first light-emitting pixel and a second light-emitting pixel portion containing luminescent nanocrystal particles that absorb light with a wavelength in the range of 420 to 480 nm and emit light with an emission peak wavelength in the range of 500 to 560 nm.

The light conversion layer may further include a non-emissive pixel portion containing light scattering particles.

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

According to the present invention, an inkjet ink for color filters that contains luminescent nanocrystal particles and has a high content of non-volatile matter, has a viscosity appropriate for forming a pixel portion, and can suppress thickening in an atmospheric environment. Ink, and a light conversion layer and color filter using the inkjet ink can be provided.

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

Hereinafter, embodiments of the present invention will be described in detail.

＜Inkjet ink＞

The inkjet ink of one embodiment contains luminescent nanocrystal particles, a photopolymerizable compound and/or thermosetting resin, and light scattering particles. This inkjet ink is an inkjet ink for color filters that is used to form the pixel portion of a color filter by the inkjet method.

Since the inkjet ink of the present embodiment is used to form a color filter pixel portion by the inkjet method, it does not needlessly consume relatively expensive materials such as luminescent nanocrystal particles and solvents, and only uses the required amount at the required location. A color filter pixel portion (light conversion layer) can be formed.

[Luminescent nanocrystal particles]

Luminescent nanocrystal particles are nano-sized crystals that absorb excitation light and emit fluorescence or phosphorescence, for example, crystals with a maximum particle diameter of 100 nm or less as measured by a transmission electron microscope or scanning electron microscope.

For example, luminescent nanocrystal particles can absorb light of a predetermined wavelength and emit light (fluorescence or phosphorescence) of a different wavelength than the absorbed wavelength. The luminescent nanocrystal particles may be red luminescent nanocrystal particles (red luminescent nanocrystal particles) that emit light (red light) having an emission peak wavelength in the range of 605 to 665 nm, or may have an emission peak wavelength in the range of 500 to 560 nm. It may be a green-emitting nanocrystal particle (green light-emitting nanocrystal particle) that emits light (green light), or a blue-emitting nanocrystal particle (blue light) that emits light (blue light) with a peak emission wavelength in the range of 420 to 480 nm. luminescent nanocrystal particles) may also be used. In this embodiment, it is preferable that the inkjet ink contains at least one type of these luminescent nanocrystal particles. In addition, the light absorbed by the luminescent nanocrystal particles is, for example, light (blue light) with a wavelength in the range of 400 nm to less than 500 nm (in particular, light with a wavelength in the range of 420 to 480 nm), or light in the range of 200 nm to 400 nm. It may be light of a wavelength (ultraviolet light). Additionally, the emission peak wavelength of the luminescent nanocrystal particles can be confirmed, for example, in a fluorescence spectrum or phosphorescence spectrum measured using a spectrofluorescence photometer.

The red luminescent nanocrystal particles are 665 nm or less, 663 nm or less, 660 nm or less, 658 nm or less, 655 nm or less, 653 nm or less, 651 nm or less, 650 nm or less, 647 nm or less, 645 nm or less, 643 nm or less, 640 nm or less, 637 nm or less, 635 nm or less, It is preferable to have an emission peak wavelength at 632 nm or less or 630 nm or less, and to have an emission peak wavelength at 628 nm or more, 625 nm or more, 623 nm or more, 620 nm or more, 615 nm or more, 610 nm or more, 607 nm or more, or 605 nm or more. These upper and lower limits can be arbitrarily combined. In addition, even in the same description below, the individually described upper and lower limits can be arbitrarily combined.

The green luminescent nanocrystal particles have an emission peak wavelength at 560 nm or less, 557 nm or less, 555 nm or less, 550 nm or less, 547 nm or less, 545 nm or less, 543 nm or less, 540 nm or less, 537 nm or less, 535 nm or less, 532 nm or less, or 530 nm or less. It is preferable to have an emission peak wavelength at 528 nm or more, 525 nm or more, 523 nm or more, 520 nm or more, 515 nm or more, 510 nm or more, 507 nm or more, 505 nm or more, 503 nm or more, or 500 nm or more.

The blue luminescent nanocrystal particles have an emission peak wavelength at 480 nm or less, 477 nm or less, 475 nm or less, 470 nm or less, 467 nm or less, 465 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 455 nm or less, 452 nm or less, or 450 nm or less. It is preferable to have a peak emission wavelength at 450 nm or more, 445 nm or more, 440 nm or more, 435 nm or more, 430 nm or more, 428 nm or more, 425 nm or more, 422 nm or more, or 420 nm or more.

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

The luminescent nanocrystal particles may be luminescent nanocrystal particles (luminescent semiconductor nanocrystal particles) containing a semiconductor material. Examples of luminescent semiconductor nanocrystal particles include quantum dots and quantum rods. Among these, quantum dots are preferable from the viewpoint of easy control of the emission spectrum, ensuring reliability, reducing production costs, and improving mass productivity.

The luminescent semiconductor nanocrystal particles may consist only of a core containing a first semiconductor material, or may include a core containing a first semiconductor material and a second semiconductor material different from the first semiconductor material, and at least a portion of the core. It may have a shell covering it. In other words, the structure of the luminescent semiconductor nanocrystal particle may be a structure consisting of only a core (core structure) or a structure consisting of a core and a shell (core/shell structure). In addition, the luminescent semiconductor nanocrystal particles include a third semiconductor material different from the first and second semiconductor materials in addition to a shell (first shell) containing the second semiconductor material, and cover at least a portion of the core. You may have an additional shell (second shell). In other words, the structure of the luminescent semiconductor nanocrystal particle may be a structure consisting of a core, a first shell, and a second shell (core/shell/shell structure). Each of the core and shell may be a mixed crystal containing two or more types of semiconductor materials (for example, CdSe + CdS, CIS + ZnS, etc.).

The luminescent nanocrystal particles are semiconductor materials, and are at least 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. It is preferable to include one type of 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, HgZnSeTe, HgZnSTe；GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb , InN, InP, InAs , InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs , GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb；SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, 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. Light-emitting semiconductor nanocrystal particles are CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, from the viewpoint of easy control of the emission spectrum, securing reliability, reducing production costs, and improving mass production. , 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 .

Red-emitting semiconductor nanocrystal particles include, for example, CdSe nanocrystal particles, nanocrystal particles with a core/shell structure, wherein the shell portion is CdS and the inner core portion is CdSe, and core/shell Nanocrystal particles with a structure, including nanocrystal particles in which the shell portion is CdS and the inner core portion is ZnSe, nanocrystal particles of a mixed crystal of CdSe and ZnS, nanocrystal particles of InP, and nanocrystal particles with a core/shell structure. As a nanocrystal particle, the shell part is ZnS and the inner core part is InP, a nanocrystal particle with a core/shell structure, the shell part is a mixed crystal of ZnS and ZnSe, and the inner core part is InP, A nanocrystal particle of a mixed crystal of CdSe and CdS, a nanocrystal particle of a mixed crystal of ZnSe and Cds, and a nanocrystal particle with a core/shell/shell structure, wherein the first shell portion is ZnSe and the second shell portion is ZnS, Nanocrystal particles in which the inner core part is InP, nanocrystal particles with a core/shell/shell structure, wherein 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. Nanocrystal particles, etc. can be mentioned.

Green luminescent semiconductor nanocrystal particles include, for example, CdSe nanocrystal particles, mixed crystal nanocrystals of CdSe and ZnS, and nanocrystal particles with a core/shell structure, where the shell portion is ZnS and the inner core is Nanocrystal particles with added InP, nanocrystal particles with a core/shell structure, wherein the shell portion is a mixed crystal of ZnS and ZnSe, and the inner core portion is InP, nanocrystals with a core/shell/shell structure. As a particle, the first shell part is ZnSe, the second shell part is ZnS, and the inner core part is InP. A nanocrystal particle with a core/shell/shell structure, wherein the first shell part is ZnS and Examples include nanocrystal particles that are mixed crystals of ZnSe, where the second shell portion is ZnS, and the inner core portion is InP.

Blue-emitting semiconductor nanocrystal particles include, for example, ZnSe nanocrystal particles, ZnS nanocrystal particles, and nanocrystal particles with a core/shell structure, wherein the shell portion is ZnSe and the inner core portion is ZnS. Crystal particles, nanocrystal particles of CdS, nanocrystal particles with a core/shell structure, wherein the shell portion is ZnS and the inner core portion is InP, nanocrystal particles with a core/shell structure, A nanocrystal particle in which the shell part is a mixed crystal of ZnS and ZnSe and the inner core part is InP, a nanocrystal particle with a core/shell/shell structure, the first shell part is ZnSe, the second shell part is ZnS, and the inner core part is InP. A nanocrystal particle with a core part of InP, a nanocrystal particle with a core/shell/shell structure, wherein 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. Crystal particles, etc. can be mentioned.

The color to be emitted from the semiconductor nanocrystal particles can be changed to red or green by changing the average particle diameter of the semiconductor nanocrystal particles with the same chemical composition. In addition, it is desirable to use semiconductor nanocrystal particles that have as little adverse effects on the human body as possible. When using semiconductor nanocrystal particles containing cadmium, selenium, etc. as luminescent nanocrystal particles, semiconductor nanocrystal particles that do not contain the above elements (cadmium, selenium, etc.) as much as possible may be selected and used alone, or the elements may be used alone as much as possible. It is preferable to use it in combination with other luminescent nanocrystal particles to reduce the amount.

The shape of the luminescent nanocrystal particles is not particularly limited, and may be any geometric shape or any irregular shape. The shape of the luminescent nanocrystal particles may be, for example, a sphere shape, an ellipsoid shape, a pyramid shape, a disk shape, a branch shape, a net shape, a rod shape, etc. However, as the luminescent nanocrystal particles, it is preferable to use particles with less orientation as the particle shape (for example, spherical, tetrahedral, etc. particles) since this can further improve the uniformity and fluidity of the inkjet ink.

The average particle diameter (volume average diameter) of the luminescent nanocrystal particles may be 1 nm or more, 1.5 nm or more, or 2 nm or more from the viewpoint of easy to obtain light emission of the desired wavelength and excellent dispersibility and storage stability. do. 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 particles is obtained by measuring using a transmission electron microscope or scanning electron microscope and calculating the volume average diameter.

The luminescent nanocrystal particles have an organic ligand on their surface from the viewpoint of dispersion stability. For example, the organic ligand may be coordinated to the surface of the luminescent nanocrystal particle. In other words, the surface of the luminescent nanocrystal particle may be passivated with an organic ligand. In addition, when the inkjet ink further contains a polymer dispersant described later, the luminescent nanocrystal particles may have a polymer dispersant on their surfaces. In this embodiment, for example, the organic ligand may be removed from the luminescent nanocrystal particles having the organic ligand described above, and the polymer dispersant may be bound to the surface of the luminescent nanocrystal particle by exchanging the organic ligand and the polymer dispersant. However, from the viewpoint of dispersion stability when used as inkjet ink, it is preferable that a polymer dispersant is blended into the luminescent nanocrystal particles coordinated with the organic ligand.

The organic ligand may contain a functional group (hereinafter also referred to as an “affinity group”) to ensure affinity with a photopolymerizable compound, thermosetting resin, organic solvent, etc. 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. Additionally, the aliphatic hydrocarbon group may have an unsaturated bond or may not have an unsaturated bond. A substituted aliphatic hydrocarbon is one in which some carbon atoms of an aliphatic hydrocarbon group are replaced with oxygen atoms. The substituted aliphatic hydrocarbon group may include, for example, a (poly)oxyalkylene group.

The organic ligand preferably contains a polyoxyalkylene group. A polyoxyalkylene group is a divalent group formed by connecting two or more alkylene groups through an ether bond, and has a plurality of oxyalkylene structures (oxyalkylene groups). The plurality of alkylene groups constituting the polyoxyalkylene group may be the same or different from each other. The alkylene group may be linear or may have a branched structure.

The carbon number of the alkylene group may be, for example, 1 or more, 2 or more, or 3 or more, and may be 5 or less, 4 or less, or 3 or less. The alkylene group is preferably an ethylene group, a propylene group, or a butylene group. That is, the polyoxyalkylene group is preferably an oxyalkylene structure (oxyethylene structure) having an ethylene group, an oxyalkylene structure (oxypropylene structure) having a propylene group, and an oxyalkylene structure (oxyalkylene structure) having a butylene group. butylene structure).

The polyoxyalkylene group preferably has an oxyalkylene structure represented by the following formula (1).

In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a methyl group, or an ethyl group, and * represents a bond. When one of R ¹ and R ² is a methyl group or an ethyl group, the other is preferably a hydrogen atom. R ¹ and R ² are preferably hydrogen atoms or methyl groups. Among them, an oxyethylene structure in which R ¹ and R ² are hydrogen atoms, or an oxypropylene structure in which one of R ¹ and R ² is a methyl group and the other is a hydrogen atom, is more preferable.

When the polyoxyalkylene group has a plurality of structures represented by formula (1), the plurality of R ¹ may be the same or different, and the plurality of R ² may be the same or different.

The degree of polymerization of the polyoxyalkylene group may be, for example, 2 or more, 4 or more, or 6 or more, and may be 40 or less, 30 or less, or 20 or less. Here, the degree of polymerization of the polyoxyalkylene group refers to the number of repetitions of the oxyalkylene structure (the number of alkylene groups connected by an ether bond. If two or more types of oxyalkylene groups (oxyalkylene structures) are included, the total number of them.) means.

When the polyoxyalkylene group contains repeats of the oxyethylene structure, the number of repeats of the oxyethylene structure may be 2 or more, 4 or more, or 6 or more, and may be 40 or less, 30 or less, or 20 or less.

When the polyoxyalkylene group contains repeats of the oxypropylene structure, the number of repeats of the oxypropylene structure may be 2 or more, 4 or more, or 6 or more, and may be 40 or less, 30 or less, or 20 or less.

The polyoxyalkylene group may be contained in the main chain of the organic ligand. Here, the main chain refers to the longest of the molecular chains constituting the organic ligand.

The organic ligand preferably contains a functional group that can bind to the luminescent nanocrystal particles (a functional group to ensure adsorption to the luminescent nanocrystal particles). Examples of functional groups that can be bonded to the luminescent nanocrystal particles include hydroxyl group, amino group, carboxyl group, thiol group, phosphoric acid group, phosphonic acid group, phosphine group, phosphine oxide group, and alkoxysilyl group. These functional groups may be bonded to the luminescent nanocrystal particles by a coordination bond or the like.

The number of functional groups in the organic ligand that can be bonded to the luminescent nanocrystal particles may be 1 to 3, 1 to 2, or 1. At least one of the functional groups that can be bonded to the luminescent nanocrystal particles in the organic ligand that the luminescent nanocrystal particles have on their surface may be a functional group bonded to the luminescent nanocrystal particles. Additionally, when the organic ligand contains a plurality of functional groups capable of bonding to the luminescent nanocrystal particles, some of the plurality of functional groups do not need to be bonded to the luminescent nanocrystal particles.

The functional group capable of bonding to the luminescent nanocrystal particle may be present at at least one terminal of the main chain of the organic ligand. That is, the organic ligand may contain a functional group capable of bonding to the luminescent nanocrystal particle at at least one terminal of the main chain.

The organic ligand may have a hydrogen bonding group. Here, the hydrogen-bonding functional group means a group having a hydrogen atom that can form a hydrogen bond with a carbonyl group or the like. The hydrogen bondable group also serves as a group capable of bonding to the luminescent nanocrystal particles. The organic ligand present on the surface of the luminescent nanocrystal particles preferably has a hydrogen bonding group that is not bonded to the luminescent nanocrystal particles. Examples of the hydrogen bonding group include monovalent groups such as hydroxyl group, amino group, carboxyl group, and thiol group, and divalent groups such as amide group (-NHCO-).

The organic ligand may have one or more first functional groups capable of bonding to the luminescent nanocrystal particles at one end of the main chain, and may have a second functional group different from the first functional group at the other end of the main chain. The first functional group is a functional group capable of bonding to the luminescent nanocrystal particles and may be the same as the groups described above. The number of the first functional groups may be 1 or more, 2 or more, or 2. The second functional group is a functional group that can be bonded to the luminescent nanocrystal particle and may be the same as the groups described above, or may be other groups different from the functional group. Other groups may be, for example, an alkyl group, cycloalkyl group, or aryl group. The number of second functional groups may be 1 or more, and may be 1.

The main chain may have, for example, a substituted or unsubstituted hydrocarbon group in addition to the polyoxyalkylene group. The number of carbon atoms of the substituted or unsubstituted hydrocarbon group may be, for example, 1 to 10. In the substituted hydrocarbon group, some of the carbon atoms may be substituted with heteroatoms such as sulfur atoms or nitrogen atoms, carbonyl groups, etc.

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

In formula (1-1), p represents an integer from 0 to 50, and q represents an integer from 0 to 50. It is preferable that at least one of p and q is 1 or more, and it is more preferable that both p and q are 1 or more.

In one embodiment, the organic ligand may be an organic ligand represented by the following formula (1-2).

In formula (1-2), r represents an integer of 1 to 50.

In the organic ligand represented by formula (1-2), r may be an integer of 1 to 20, an integer of 3 to 15, an integer of 5 to 10, or 7.

The organic ligand may be a ligand having two or more functional groups capable of binding to luminescent nanocrystal particles. That is, in one embodiment, the organic ligand may be a compound represented by the following formula (1-3).

In formula (1-3), A ¹ and A ² each independently represent a monovalent group that may contain a functional group capable of bonding to the above-mentioned luminescent nanocrystal particles, and R is a hydrogen atom, a methyl group, or an ethyl group. represents, L ¹ and L ² each independently represent a substituted or unsubstituted alkylene group, and s represents an integer of 0 or more. However, at least one of A ¹ and A ² contains a functional group that can be bonded to the above-mentioned luminescent nanocrystal particles, and the total number of functional groups that can be bonded to the luminescent nanocrystal particles in A ¹ and A ² is 2. That's it. When A ¹ and A ² are groups that do not contain a functional group capable of bonding to the luminescent nanocrystal particles, A ¹ and A ² may be, for example, hydrogen atoms.

The number of functional groups that can be bonded to the luminescent nanocrystal particles in the monovalent groups represented by A ¹ and A ² may be 1 or 2 or more, 4 or less, or 2, respectively. The functional group capable of bonding to the luminescent nanocrystal particles is preferably at least one selected from the group consisting of a hydroxyl group and a carboxyl group.

In one embodiment, the number of functional groups that can be bonded to the luminescent nanocrystal particles in the monovalent group represented by A ¹ is two, and the number of functional groups that can be bonded to the luminescent nanocrystal particles in the monovalent group represented by A ² It is desirable that the number is 1. In this case, the functional groups capable of bonding to the two luminescent nanocrystal particles in the monovalent group represented by A ¹ are all carboxyl groups, and the functional group capable of bonding to the luminescent nanocrystal particles in the monovalent group represented by A ² is hydroxyl. It is more desirable to have practical skills.

In another embodiment, the number of functional groups in the monovalent group represented by A ¹ that can be bonded to the luminescent nanocrystal particle is two, and A ² is a hydrogen atom (that is, in the monovalent group represented by A ² It is preferable that the number of functional groups that can be combined with the luminescent nanocrystal particles is 0). In this case, it is more preferable that all functional groups capable of bonding to two luminescent nanocrystal particles in the monovalent group represented by A ¹ are carboxyl groups.

The carbon number of the alkylene group represented by L may be, for example, 1 to 10. In the alkylene group represented by L, some of the carbon atoms (methylene group) may be substituted with heteroatoms. When L is a substituted alkylene group, a part of the carbon atoms (methylene group) in the alkylene group is preferably substituted with at least one hetero atom selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom. and, more preferably, is substituted with a sulfur atom. For example, s may be an integer of 1 or more, 3 or more, or 5 or more, and may be an integer of 100 or less, 20 or less, or 10 or less.

The organic ligand may be a compound represented by the following formula (1-4).

In formula (1-4), x and y are each independently an integer of 0 or more, z is an integer of 1 or more, and A ¹ , A ² and s are A ¹ and A ² in formula (1-3). and s, respectively. However, at least one of x and y is an integer of 1 or more.

x may be an integer of 3 or less or 2 or less, may be 1, or may be 0. y may be an integer of 1 or more, 2 or more, or 3 or more, may be an integer of 5 or less, 4 or less, or 3 or less, and may be 3. z may be an integer of 4 or less, 3 or less, or 2 or less, and may be 1.

The organic ligand may be a compound represented by the following formula (1-5) or (1-6).

In equations (1-5) and (1-6), s is the same as s in equation (1-3).

Organic ligands containing functional groups capable of binding to luminescent nanocrystal particles include, for example, TOP (trioctylphosphine), TOPO (trioctylphosphine oxide), lauric acid, oleic acid, oleylamine, octylamine, and triamine. Octylamine, hexadecylamine, octanethiol, dodecanethiol, hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), and octylphosphinic acid (OPA).

In one embodiment, the organic ligand may be an organic ligand represented by the following formula (1-7).

In formula (1-7), n represents an integer from 0 to 50, and m represents an integer from 0 to 50. n is preferably 0 to 20, and more preferably 0 to 10. m is preferably 0 to 20, and more preferably 0 to 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 number of carbon atoms of the alkylene group may be, for example, 1 to 10. The alkylene group represented by Z may have some of its carbon atoms substituted with heteroatoms or may be substituted with at least one heteroatom selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom.

The weight average molecular weight of the organic ligand may be 1000 or less, 900 or less, 800 or less, 700 or less, or 600 or less, or 250 or more, 300 or more, from the viewpoint of making the viscosity of the inkjet ink more appropriate for forming the pixel portion. It may be 400 or more, 450 or more, 500 or more, or 550 or more. In addition, in this specification, the weight average molecular weight is the weight average molecular weight in terms of polystyrene measured by GPC (Gel Permeation Chromatography).

As luminescent nanocrystal particles, those dispersed in a colloidal form in an organic solvent, a photopolymerizable compound, etc. can be used. The surface of the luminescent nanocrystal particles dispersed in an organic solvent is preferably passivated by the organic ligand described above. Organic solvents include, for example, cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether, propylene glycol monomethyl ether acetate, butylcarbitol acetate, and 1,4-butanediol diol. acetate, or mixtures thereof.

As luminescent nanocrystal particles, commercial products can be used. Examples of commercially available luminescent nanocrystal particles include indium phosphorus/zinc sulfide, D-dot, CuInS/ZnS from NN-LAB, and InP/ZnS from ALDRICH.

The content of the luminescent nanocrystal particles is the total content (non-volatile content) of the luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light-scattering particles in the inkjet ink from the viewpoint of more excellent effect of improving the maintenance rate of external quantum efficiency. The total content of) is preferably more than 10 parts by mass, more preferably 13 parts by mass or more, and even more preferably 15 parts by mass or more, relative to 100 parts by mass. When the content of luminescent nanocrystal particles is more than 10 parts by mass, excellent luminous intensity is obtained, and therefore such inkjet ink is suitably used as a color filter. The content of the luminescent nanocrystal particles is, from the viewpoint of superior ejection stability, the total content of the luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light scattering particles in the inkjet ink (total content of non-volatile matter) 100 mass. Regarding parts, it is preferably 60 parts by mass or less, may be 50 parts by mass or less, may be 40 parts by mass or less, and may be 35 parts by mass or less. The content of the luminescent nanocrystal particles exceeds 10 parts by mass with respect to 100 parts by mass of the total content (total content of non-volatile matter) of the luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light scattering particles in the inkjet ink. It may be 60 parts by mass or less, 13 to 60 parts by mass, 15 to 60 parts by mass, more than 10 parts by mass and 50 parts by mass or less, more than 10 parts by mass and 40 parts by mass or less, or more than 10 parts by mass and 35 parts by mass or less.

The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles (total content of non-volatile matter) in the inkjet ink is 41% by mass or more, based on the total mass of the inkjet ink, 45 mass% or more, 50 mass% or more, 55 mass% or more, 60 mass% or more, 65 mass% or more, 70 mass% or more, 75 mass% or more, 80 mass% or more, 85 mass% or more, 90 mass% or more, or It may be 95% by mass or more, and may be 100% by mass. When the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles (total content of non-volatile matter) in the inkjet ink is 70% by mass or more based on the total mass of the inkjet ink, solvent It is suitably used as an inkjet ink that does not contain.

When the inkjet ink contains a photopolymerizable compound and does not contain a thermosetting resin, the total content of the non-volatile content is the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, and light scattering particles. In addition, when the inkjet ink contains a thermosetting resin and does not contain a photopolymerizable compound, the total content of the non-volatile content is the total content of luminescent nanocrystal particles, organic ligands, thermosetting resin, and light scattering particles. .

The inkjet ink may contain two or more types of luminescent nanocrystal particles, such as red luminescent nanocrystal particles, green luminescent nanocrystal particles, and blue luminescent nanocrystal particles, but preferably contains only one type of these particles. When the inkjet ink contains red luminescent nanocrystal particles, the content of green luminescent nanocrystal particles and the content of blue luminescent nanocrystal particles are preferably 10% by mass or less, based on the total mass of luminescent nanocrystal particles. , more preferably 0 mass%. When the inkjet ink contains green luminescent nanocrystal particles, the content of red luminescent nanocrystal particles and the content of blue luminescent nanocrystal particles are preferably 10% by mass or less, based on the total mass of luminescent nanocrystal particles. , more preferably 0 mass%.

The total content of luminescent nanocrystal particles and organic ligands is 21 parts by mass or more, based on 100 parts by mass of the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles in the inkjet ink, and 25 It may be at least 70 parts by mass, at least 27 parts by mass, at least 30 parts by mass, at least 35 parts by mass, at least 40 parts by mass, at least 45 parts by mass, or at least 50 parts by mass, and at most 70 parts by mass, at most 65 parts by mass, and at most 60 parts by mass. Alternatively, it may be 55 parts by mass or less.

The content of the organic ligand is 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass, from the viewpoint of suppressing thickening of the inkjet ink due to exposure to the atmosphere, with respect to a total content of 100 parts by mass of the luminescent nanocrystal particles and the organic ligand. It may be more than or equal to 32 parts by mass, or less than or equal to 50 parts by mass, less than or equal to 45 parts by mass, or less than or equal to 40 parts by mass, or less than or equal to 38 parts by mass. It is preferable that the content of the organic ligand is 50 parts by mass or less relative to the total content of the luminescent nanocrystal particles and the organic ligand of 100 parts by mass, because the content of the luminescent nanocrystal particles in the inkjet ink can be relatively increased. In this specification, the content of organic ligands relative to 100 parts by mass of the total content of luminescent nanocrystal particles and organic ligands is the organic ratio (organic compound is defined as the ratio of). A mixture consisting of luminescent nanocrystal particles and an organic ligand can be obtained by adding a poor solvent of the mixture to inkjet ink, allowing the mixture to precipitate, and then drying it.

[Photopolymerizable compound]

The photopolymerizable compound of this embodiment is a compound polymerized by irradiation of light, for example, a radically photopolymerizable compound or a photocationic polymerizable compound. The photopolymerizable compound may be a photopolymerizable monomer or oligomer. These are used together with a photopolymerization initiator. The radically photopolymerizable compound is used with a photoradical polymerization initiator, and the photocationic polymerizable compound is used with a photocationic polymerization initiator. In other words, the inkjet ink may contain a photopolymerizable component including a photopolymerizable compound and a photopolymerization initiator, or may contain a photopolymerizable component including a radical photopolymerizable compound and a radical photopolymerization initiator. It may contain a photocationic polymerizable component including an ionic polymerizable compound and a photocationic polymerization initiator. A radical photopolymerizable compound and a photocationic polymerizable compound may be used together, a compound having photoradical polymerization and photocationic polymerization may be used, or a radical photopolymerization initiator and a photocationic polymerization initiator may be used together. Photopolymerizable compounds may be used individually or in combination of two or more types.

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

The number of ethylenically unsaturated bonds (for example, the number of ethylenically unsaturated groups) in the ethylenically unsaturated monomer is, for example, 1 to 3. Ethylenically unsaturated monomers may be used individually by one type, or may be used in combination of multiple types. The photopolymerizable compound contains a monomer having one or two ethylenically unsaturated groups and two ethylenically unsaturated groups from the viewpoint of making it easier to achieve both excellent discharge stability and excellent curing properties and further improving external quantum efficiency. Alternatively, it may contain three monomers. That is, the ethylenically unsaturated monomer is at least one selected from the group consisting of monofunctional monomers and difunctional monomers, monofunctional monomers and trifunctional monomers, difunctional monomers and bifunctional monomers, and difunctional monomers and trifunctional monomers. It may contain a combination of . In this embodiment, it is preferable that the photopolymerizable compound contains two or more types of monomers having two ethylenically unsaturated bonds.

Examples of the ethylenically unsaturated group include vinyl group, vinylene group, vinylidene group, and (meth)acryloyl group. In addition, in this specification, “(meth)acryloyl group” means “acryloyl group” and “methacryloyl group” corresponding thereto. The same applies to the expressions “(meth)acrylate” and “(meth)acrylamide.”

Examples of monofunctional monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. ) Acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, Methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, nonylphenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl ( Meth)acrylate, diethylaminoethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate ) Acrylate, dicyclopentenyloxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth) Acrylate, benzyl (meth)acrylate, phenylbenzyl (meth)acrylate, mono(2-acryloyloxyethyl) succinate, mono(2-methacryloyloxyethyl) succinate, N-[2-(acrylic) Loyloxy)ethyl]phthalimide, N-[2-(acryloyloxy)ethyl]tetrahydrophthalimide, 4-hydroxybutylacrylate, 2-hydroxypropylacrylate, 2-hydroxyethyl Acrylates, etc. can be mentioned. Among these, ethoxyethoxyethyl (meth)acrylate is preferably used.

Specific examples of monomers (bifunctional monomers) having two ethylenically unsaturated groups include 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,5-pentanediol 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 Latex, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol hydroxypivalic acid ester di. Acrylate, di(meth)acrylate in which two hydroxyl groups of tris(2-hydroxyethyl)isocyanurate are replaced by (meth)acryloyloxy groups, 4 moles or more of ethylene oxide per mole of neopentyl glycol, or Di(meth)acrylate obtained by adding propylene oxide, in which two hydroxyl groups of the diol are replaced by (meth)acryloyloxy groups; diol 2 obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A Di(meth)acrylate in which two hydroxyl groups are substituted by a (meth)acryloyloxy group, and two hydroxyl groups of triol obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane are (meth)acrylates. Di(meth)acrylate substituted by a loyloxy group, diol obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A, and two hydroxyl groups of the diol are substituted by a (meth)acryloyloxy group. Meta)acrylate, etc. can be mentioned. Among these, dipropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol diacrylate are preferably used.

Specific examples of the monomer (trifunctional monomer) having three ethylenically unsaturated groups include glycerol tri(meth)acrylate, trimethylolethane tri(meth)acrylate, and the like. Among these, glycerol tri(meth)acrylate is preferably used.

Examples of photocationically polymerizable compounds include epoxy compounds, oxetane compounds, and vinyl ether compounds.

As epoxy compounds, aliphatic epoxy compounds such as bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, phenol novolak-type epoxy compounds, trimethylolpropane polyglycidyl ether, and neopentyl glycol diglycidyl ether, 1,2 -alicyclic epoxy compounds such as epoxy-4-vinylcyclohexane and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane; and the like.

It is also possible to use a commercial product as the epoxy compound. Commercially available epoxy compounds include, for example, DAICEL CHEMICAL INDUSTRIES, LTD. Products such as “CELOXIDE 2000”, “CELOXIDE 3000”, and “CELOXIDE 4000” can be used.

Examples of cationically polymerizable oxetane compounds include 2-ethylhexyloxetane, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, and 3-hydroxymethyl-3-propyloxetane. , 3-hydroxymethyl-3-normalbutyloxetane, 3-hydroxymethyl-3-phenyloxetane, 3-hydroxymethyl-3-benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-Hydroxyethyl-3-ethyloxetane, 3-hydroxyethyl-3-propyloxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3-methyloxetane, 3- Hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyloxetane, 3-hydroxypropyl-3-phenyloxetane, 3-hydroxybutyl-3-methyloxetane, etc. .

It is also possible to use a commercial product as the oxetane compound. Commercially available oxetane compounds include, for example, TOAGOSEI CO., LTD. Manufactured by ARON OXETANE series (“OXT-101”, “OXT-212”, “OXT-121”, “OXT-221”, etc.); DAICEL CHEMICAL INDUSTRIES, LTD. Manufacturing 「CELOXIDE 2021」, 「CELOXIDE 2021A」, 「CELOXIDE 2021P」, 「CELOXIDE 2080」, 「CELOXIDE 2081」, 「CELOXIDE 2083」, 「CELOXIDE 2085」, 「EPOLEAD GT300」, 「EPOLEAD GT301」, 「EPOLEAD D GT302 ”, 「EPOLEAD GT400」, 「EPOLEAD GT401」 and 「EPOLEAD GT403」；DOW CHEMICAL JAPAN LTD. Products such as “CYRACURE UVR-6105”, “CYRACURE UVR-6107”, “CYRACURE UVR-6110”, “CYRACURE UVR-6128”, “ERL4289”, and “ERL4299” can be used. Additionally, known oxetane compounds (for example, oxetane compounds described in Japanese Patent Application Laid-Open No. 2009-40830, etc.) can also be used.

Examples of vinyl ether compounds include 2-hydroxyethyl vinyl ether, triethylene glycol vinyl monoether, tetraethylene glycol divinyl ether, and trimethylolpropane trivinyl ether.

Additionally, as the photopolymerizable compound in this embodiment, the photopolymerizable compound described in paragraphs 0042 to 0049 of Japanese Patent Application Laid-Open No. 2013-182215 can also be used.

The photopolymerizable compound may be alkali-insoluble from the viewpoint of making it easy to obtain a highly reliable pixel portion (cured product of inkjet ink). In this specification, the fact that the photopolymerizable compound is alkali insoluble means that the amount of dissolution of the photopolymerizable compound at 25°C in a 1 mass% aqueous solution of potassium hydroxide is 30 mass% or less based on the total mass of the photopolymerizable compound. it means. The amount of the photopolymerizable compound dissolved is preferably 10 mass% or less, and more preferably 3 mass% or less.

The content of the photopolymerizable compound is determined from the viewpoint of making it easy to obtain an appropriate viscosity as an inkjet ink, improving the curability of the inkjet ink, and improving the solvent resistance and abrasion resistance of the pixel portion (cured product of the inkjet ink). The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles in the ink may be 10 parts by mass or more, may be 15 parts by mass or more, and may be 20 parts by mass or more. . The content of the photopolymerizable compound is determined from the viewpoint of making it easy to obtain an appropriate viscosity as an inkjet ink, and from the viewpoint of obtaining better optical properties (e.g., effect of suppressing decline in external quantum efficiency), luminescent nanocrystal particles, organic With respect to the total content of 100 parts by mass of the ligand, photopolymerizable compound, thermosetting resin, and light scattering particles, it may be 60 parts by mass or less, may be 50 parts by mass or less, may be 40 parts by mass or less, and may be 30 parts by mass or less; It may be 20 parts by mass or less.

[Photopolymerization initiator]

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

As molecular cleavage type photo radical polymerization initiator, benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2- Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, (2, 4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide and the like are suitably used. Other molecular cleavage type photo radical polymerization initiators include 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -(4-Isopropylphenyl)-2-hydroxy-2-methylpropan-1-one and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one can be used together. do.

Examples of the hydrogen abstraction type radical photopolymerization initiator include benzophenone, 4-phenylbenzophenone, isophthalic phenone, and 4-benzoyl-4'-methyl-diphenyl sulfide. A molecular cleavage type photoradical polymerization initiator and a hydrogen abstraction type photoradical polymerization initiator may be used together.

A commercial product can also be used as a photocationic polymerization initiator. Commercially available products include sulfonium salt-based photocationic polymerization initiators such as “CPI-100P” manufactured by SUN-APRO, acylphosphine oxide compounds such as “Lucirin TPO” manufactured by BASF, and “Irgacure 907” manufactured by BASF. Examples include “Irgacure 819”, “Irgacure 379EG”, “Irgacure 184”, and “Irgacure PAG290”.

The content of the photopolymerization initiator may be 0.1 part by mass or more, 0.5 part by mass or more, 1 part by mass or more, or 3 parts by mass or more, with respect to 100 parts by mass of the photopolymerizable compound, from the viewpoint of curability of the inkjet ink. , may be 5 parts by mass or more. The content of the photopolymerization initiator may be 40 parts by mass or less, 30 parts by mass or less, and even 20 parts by mass or less with respect to 100 parts by mass of the photopolymerizable compound, from the viewpoint of temporal stability of the pixel portion (cured product of inkjet ink). It may be 10 parts by mass or less.

[Thermosetting resin]

In this embodiment, a thermosetting resin is a resin that is crosslinked and hardened by heat. A thermosetting resin is, for example, a resin that functions as a binder in a cured product. Thermosetting resin has a curable group. Examples of the curable group include an epoxy group, an oxetane group, an isocyanate group, an amino group, a carboxyl group, and a methylol group. The cured product of the inkjet ink has excellent heat resistance and storage stability, and a light-shielding portion (for example, a black matrix). From the viewpoint of excellent adhesion to the substrate, an epoxy group is preferable. The thermosetting resin may have one type of curable group, or may have two or more types of curable group.

In addition, among the thermosetting resins, there are those that have radical photopolymerizability (polymerized by irradiation of light when used with a radical photopolymerization initiator), and those that have photocationic polymerizability (when used with a photocationic polymerization initiator). Resin (polymerized by irradiation of light) is included. When the inkjet ink contains a thermosetting resin having radical photopolymerizability and a radical photopolymerization initiator, the thermosetting resin having radical photopolymerization is classified as a radically polymerizable compound (photopolymerizable compound). When the inkjet ink contains a thermosetting resin having photocationic polymerizability and a photocationic polymerization initiator, the thermosetting resin having photocationic polymerizability is classified as a photocationic polymerizable compound (photopolymerizable compound).

The thermosetting resin may be a polymer (homopolymer) of a single monomer, or may be a copolymer (copolymer) of multiple types of monomers. Additionally, the thermosetting resin may be any of a random copolymer, a block copolymer, or a graft copolymer.

As a thermosetting resin, a compound having two or more thermosetting groups per molecule is used, and is usually used in combination with a curing agent. When using a thermosetting resin, a catalyst (curing accelerator) capable of promoting the thermosetting reaction may be further added. In other words, the inkjet ink may contain a thermosetting component including a thermosetting resin (and a curing agent and curing accelerator used as necessary). Additionally, in addition to these, a polymer that itself is not polymerization reactive may be further used.

As a compound having two or more thermosetting groups in one molecule, for example, an epoxy resin having two or more epoxy groups in one molecule (hereinafter also referred to as “polyfunctional epoxy resin”) may be used. “Epoxy resin” includes both monomeric epoxy resins and polymeric epoxy resins. The number of epoxy groups that the multifunctional epoxy resin has in one molecule is preferably 2 to 50, and more preferably 2 to 20. The epoxy group may have a structure having an oxirane ring structure, and may be, for example, a glycidyl group, oxyethylene group, or epoxy cyclohexyl group. Examples of the epoxy resin include known polyvalent epoxy resins that can be cured with carboxylic acid. These epoxy resins are widely disclosed, for example, in "Epoxy Resin Handbook" edited by Shinbo Masaki, published by the Daily Industrial Newspaper (1987), and it is possible to use them.

Thermosetting resins (including multifunctional epoxy resins) having an epoxy group include polymers of monomers having an oxirane ring structure and copolymers of monomers having an oxirane ring structure and other monomers. Specific multifunctional epoxy resins include polyglycidyl methacrylate, methyl methacrylate-glycidyl methacrylate copolymer, benzyl methacrylate-glycidyl methacrylate copolymer, and n-butyl methacrylate- Glycidyl methacrylate copolymer, 2-hydroxyethyl methacrylate-glycidyl methacrylate copolymer, (3-ethyl-3-oxetanyl)methyl methacrylate-glycidyl methacrylate copolymer Synthesis, styrene-glycidyl methacrylate, etc. are mentioned. Additionally, as the thermosetting resin of this embodiment, the compounds described in paragraphs 0044 to 0066 of Japanese Patent Application Laid-Open No. 2014-56248 can also be used.

Moreover, as a multifunctional epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, Naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolak type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional epoxy resin, tetraphenylol Ethane type epoxy resin, dicyclopentadienephenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A core-containing polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidylamine. type epoxy resin, glyoxal type epoxy resin, alicyclic type epoxy resin, heterocyclic type epoxy resin, etc. can be used.

More specifically, bisphenol A-type epoxy resins under the brand name "EPIKOTE 828" (manufactured by Japan EPOXY RESIN), bisphenol F-type epoxy resins under the brand name "YDF-175S" (manufactured by TOHTO KASEI), and brand name "YDB-715." Brominated bisphenol A-type epoxy resins such as "(manufactured by TOHTO KASEI), bisphenol S-type epoxy resins such as brand name "EPICLON EXA1514" (manufactured by DIC CORPORATION), hydroquinones such as brand name "YDC-1312" (manufactured by TOHTO KASEI) Non-type epoxy resin, brand name: "EPICLON EXA4032", "HP-4770", "HP-4700", "HP-5000" (manufactured by DIC CORPORATION), etc. Naphthalene type epoxy resin, brand name "EPIKOTE YX4000H" (manufactured by JAPAN EPOXY RESIN) ), biphenyl-type epoxy resins such as brand name "EPIKOTE 157S70" (manufactured by Japan EPOXY RESIN), bisphenol A-type novolak-based epoxy resins such as brand name "EPIKOTE 154" (manufactured by Japan EPOXY RESIN), brand name "YDPN-638" Phenol novolak-type epoxy resins such as "(manufactured by TOHTO KASEI), cresol novolak-type epoxy resins such as brand name "YDCN-701" (manufactured by TOHTO KASEI), brand names "EPICLON HP-7200", "HP-7200H" Dicyclopentadienephenol type epoxy resins such as (manufactured by DIC CORPORATION), trishydroxyphenylmethane type epoxy resins such as brand name "EPIKOTE 1032H60" (manufactured by JAPAN EPOXY RESIN), brand name "VG3101M80" (manufactured by MITSUI CHEMICAL), etc. tri-functional epoxy resins, tetraphenylolethane-type epoxy resins such as "EPIKOTE 1031S" (manufactured by Japan EPOXY RESIN), tetrafunctional epoxy resins such as "DENACOL EX-411" (manufactured by Nagase ChemteX Corporation), Hydrogenated bisphenol A type epoxy resins under the brand name “ST-3000” (manufactured by TOHTO KASEI), glycidyl ester type epoxy resins under the brand name “EPIKOTE 190P” (manufactured by JAPAN EPOXY RESIN), brand name “YH-434” Glycidylamine-type epoxy resins such as (manufactured by TOHTO KASEI), glyoxal-type epoxy resins such as brand name "YDG-414" (manufactured by TOHTO KASEI), brand name "EPOLEAD GT-401" (manufactured by DAISEL CHEMICAL), etc. Examples include alicyclic polyfunctional epoxy compounds and heterocyclic epoxy resins such as triglycidyl isocyanate (TGIC). Moreover, if necessary, brand name "NEOTOHTO E" (manufactured by TOHTO KASEI) etc. can be mixed as an epoxy reactive diluent.

In addition, as a multifunctional epoxy resin, "FINE DIC A-247S", "FINE DIC A-254", "FINE DIC A-253", "FINE DIC A-229-30A", and "FINE DIC A" manufactured by DIC CORPORATION. -261", "FINE DIC A249", "FINE DIC A-266", "FINE DIC A-241", "FINE DIC M-8020", "EPICLON N-740", "EPICLON N-770", "EPICLON N -865”, “EPICLON EXA-4850-150” (brand name), etc. can be used.

The weight average molecular weight of the thermosetting resin is from the viewpoint of making it easy to obtain an appropriate viscosity as an inkjet ink, improving the curability of the inkjet ink, and improving the solvent resistance and abrasion resistance of the pixel portion (cured product of the inkjet ink). It may be 750 or more, 1000 or more, or 2000 or more. From the viewpoint of achieving an appropriate viscosity as inkjet ink, it may be 500,000 or less, 300,000 or less, or 200,000 or less. However, the molecular weight after crosslinking is not limited to this.

The content of the thermosetting resin is determined from the viewpoint of making it easy to obtain an appropriate viscosity as an inkjet ink, improving the curability of the inkjet ink, and improving the solvent resistance and abrasion resistance of the pixel portion (cured product of the inkjet ink). The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles in 100 parts by mass may be 5 parts by mass or more, may be 10 parts by mass or more, and may be 15 parts by mass or more, It may be 20 parts by mass or more. The content of the thermosetting resin is determined from the viewpoints that the viscosity of the inkjet ink does not become too high and the thickness of the pixel portion does not become too thick for the photoconversion function, and the luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resin, And with respect to the total content of 100 parts by mass of light scattering particles, it may be 60 parts by mass or less, may be 50 parts by mass or less, may be 40 parts by mass or less, may be 30 parts by mass or less, and may be 20 parts by mass or less.

[Hardener]

Examples of curing agents used to cure thermosetting resins include acid anhydrides, phenol-based compounds, and amine-based compounds. These curing agents may be used individually or in combination of two or more types. The curing agent preferably contains at least one selected from the group consisting of acid anhydrides, phenol-based compounds, and amine-based compounds. Additionally, when using an epoxy resin as a thermosetting resin, self-polymerization may be performed using onium salts, organometallic complexes, tertiary amines, imidazoles, etc.

As acid anhydrides (acid anhydride-based curing agents), 4-methylcyclohexane-1,2-dicarboxylic anhydride (4M-HHPA), 3-methylcyclohexane-1,2-dicarboxylic anhydride, and cyclohexane-1,2- Dicarboxylic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride , Bicyclo[2.2.1]heptane-2,3-dicarboxylic acid anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid anhydride, methyl-3,6-endmethylene-1,2,3 , 6-tetrahydrophthalic anhydride, 3,6-endmethylene-1,2,3,6-tetrahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, etc.

As phenolic compounds (phenol-based curing agents), bisphenol A, bisphenol F, bisphenol S, resorcinol, catechol, hydroquinone, fluorenebisphenol, 4,4'-biphenol, 4,4',4''-tri. Hydroxytriphenylmethane, naphthalenediol, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, calixarene, novolak-type phenolic resin (e.g., phenol novolak resin, cresol Polyhydric hydroxy compounds represented by novolak resin, bisphenol A novolak resin, bisphenol S novolak resin, and resorcinol novolak resin, polyhydric phenol novolak resin synthesized from formaldehyde, naphthol-phenol coaxial novolak resin, naphthol- Cresol coaxial novolak resin, naphthol novolak resin, and alkoxy group-containing aromatic ring-modified novolak resin (polyhydric phenol compound in which a phenol nucleus and alkoxy group-containing aromatic ring are linked with formaldehyde), aralkyl type phenol resin (e.g., Phenol aralkyl resin and naphthol aralkyl resin such as polyhydric phenol compound whose phenol nucleus is connected to a bismethylene group), biphenyl-modified naphthol resin (polyhydric naphthol compound whose phenol nucleus is connected to a bismethylene group), aminotriazine-modified phenol resin (polyhydric phenol whose phenol nucleus is connected to melamine, benzoguanamine, etc. polyhydric phenol compounds such as compounds), and the like. From the viewpoint of the excellent effect of improving external quantum efficiency, it is preferable that the phenol-based compound contains a novolak-type phenol resin. As the novolak-type phenol resin, phenol novolak resin, cresol novolak resin, and bisphenol A novolak resin are preferably used.

Specific examples of novolak-type phenolic resins include "PHENOLITE TD-2131" and "PHENOLITE TD-2090" (brand name) manufactured by DIC CORPORATION, NIPPON KAYAKU CO., LTD. “GPH-65” and “GPH-103” (brand name) manufactured by the company can be mentioned.

Amine-based compounds (amine-based curing agents) include, for example, aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and pentaethylenehexamine, and methacrylates. Aromatic polyamines such as silylenediamine, diaminodiphenylmethane, phenylenediamine, alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, norbornanediamine, etc., dicyandiamide , polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine.

The curing agent is preferably an acid anhydride-based curing agent from the viewpoint of external quantum efficiency and heat resistance of the cured inkjet ink, and a phenol-based curing agent is preferable from the viewpoint of curing properties of the cured inkjet ink and viscosity stability of the inkjet ink.

For example, the content of the curing agent may be 40 parts by mass or less, and may be 30 parts by mass, based on 100 parts by mass of the total content of the luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light scattering particles in the inkjet ink. It may be less than 20 parts by mass, or less than 10 parts by mass. The content of the curing agent may be, for example, 1 part by mass or more, or 3 parts by mass, based on 100 parts by mass of the total content of the luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light scattering particles in the inkjet ink. It can be more than that.

[Curing accelerator (curing catalyst)]

Examples of curing accelerators (curing catalysts) used to cure thermosetting resins include phosphorus-based compounds, tertiary amine compounds, imidazole compounds, organic acid metal salts, Lewis acids, and amine complex salts. Examples of phosphorus-based compounds include triphenylphosphine, triphenylphosphine, diphenylcyclohexylphosphine, and methyltributylphosphonium iodide. Tertiary amine compounds include, for example, N,N-dimethylbenzylamine, 1,8-diazabicyclo(5,4,0)undecene-7,1,5-diazabicyclo(4,3,0) )Nonene-5 and tris(dimethylaminomethyl)phenol. Examples of the imidazole compound include 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole.

The thermosetting resin may be alkali-insoluble from the viewpoint of making it easy to obtain a highly reliable pixel portion (cured product of inkjet ink). That the thermosetting resin is alkali insoluble means that the dissolution amount of the thermosetting resin at 25°C in a 1 mass% potassium hydroxide aqueous solution is 30 mass% or less based on the total mass of the thermosetting resin. The amount of the thermosetting resin dissolved is preferably 10% by mass or less, and more preferably 3% by mass or less.

In this embodiment, the inkjet ink may contain at least one of a photopolymerizable compound and a thermosetting resin, and may contain both a photopolymerizable compound and a thermosetting resin. If the inkjet ink contains a photopolymerizable compound, it does not need to contain a thermosetting resin. Additionally, when the inkjet ink contains a thermosetting resin, it does not need to contain a photopolymerizable compound. From the viewpoint of storage stability of inkjet ink containing luminescent nanocrystal particles (e.g. quantum dots) and durability (moist heat stability, etc.) of the pixel portion (cured product of inkjet ink), among photopolymerizable compounds and thermosetting resins, It is preferable to use a thermosetting resin, and from the viewpoint of the storage stability of the inkjet ink containing luminescent nanocrystal particles (for example, quantum dots) and the possibility of curing at low temperatures where the quantum dots are less susceptible to deterioration by heating, optical It is more preferable to use a radically polymerizable compound, and from the viewpoint of forming a pixel portion (cured product of inkjet ink) without being inhibited by oxygen in the curing process, it is preferable to use a photocationically polymerizable compound.

When the inkjet ink contains a photopolymerizable compound and a thermosetting resin, the total content of the photopolymerizable compound and the thermosetting resin is determined from the viewpoints that an appropriate viscosity is easily obtained as the inkjet ink, the curability of the inkjet ink is improved, and the pixel portion. From the viewpoint of improving the solvent resistance and abrasion resistance of (cured product of inkjet ink), the total content of luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light scattering particles in inkjet ink is 3 parts by mass. It may be more than 5 parts by mass, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, and 20 parts by mass or more. In addition, the total content of the photopolymerizable compound and the thermosetting resin is adjusted so that the viscosity of the inkjet ink does not become too high and the thickness of the pixel portion does not become too thick for the photoconversion function, and the luminescent nanocrystal particles and organic ligands in the inkjet ink are adjusted accordingly. , may be 60 parts by mass or less, may be 40 parts by mass or less, and may be 20 parts by mass or less, with respect to a total content of 100 parts by mass of the photopolymerizable compound, thermosetting resin, and light scattering particles.

[Light scattering particles]

Light-scattering particles are, for example, optically inert inorganic fine particles. When the inkjet ink contains light-scattering particles, light from the light source irradiated on the pixel portion can be scattered, so excellent optical properties can be obtained.

Materials constituting light-scattering particles include, for example, simple metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum, and gold; silica, barium sulfate, barium carbonate, calcium carbonate, Metal oxides such as talc, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, alumina white, titanium oxide, magnesium oxide, barium oxide, aluminum oxide, bismuth oxide, zirconium oxide, zinc oxide; magnesium carbonate, barium carbonate, tea Metal carbonates such as bismuth carbonate and calcium carbonate; metal hydroxides such as aluminum hydroxide; complex oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, and strontium titanate; and metal salts such as bismuth nitrate. The light scattering particles are selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, barium titanate, and silica from the viewpoint of excellent discharge stability and a better effect of improving external quantum efficiency. It is preferable to include at least one type, and it is more preferable to include at least one type 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, irregular, or the like. However, as light scattering particles, using particles with less directionality (for example, spherical, tetrahedral particles, etc.) as the particle shape can further improve the uniformity, fluidity, and light scattering of the inkjet ink, and provide excellent discharge. This is desirable in that stability can be obtained.

The average particle diameter (volume average diameter) of the light-scattering particles in the inkjet ink may be 0.05 μm (50 nm) or more, and may be 0.2 μm (200 nm) or more from the viewpoint of excellent ejection stability and a better effect of improving external quantum efficiency. It may be 0.3μm (300nm) or more. The average particle diameter (volume average diameter) of the light-scattering particles in inkjet ink may be 1.0 μm (1000 nm) or less, 0.6 μm (600 nm) or less, or 0.4 μm (400 nm) or less from the viewpoint of excellent discharge stability. . The average particle diameter (volume average diameter) of light scattering particles in inkjet ink is 0.05 to 1.0 μm, 0.05 to 0.6 μm, 0.05 to 0.4 μm, 0.2 to 1.0 μm, 0.2 to 0.6 μm, 0.2 to 0.4 μm, 0.3 to 1.0. It may be μm, 0.3 to 0.6 μm, or 0.3 to 0.4 μm. From the viewpoint of making it easy to obtain 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 light-scattering particles in inkjet ink is obtained by measuring with a dynamic light-scattering nanotrack particle size distribution meter and calculating the volume average diameter. In addition, the average particle diameter (volume average diameter) of the light scattering particles to be used is obtained by, for example, measuring the particle diameter of each particle using a transmission electron microscope or scanning electron microscope and calculating the volume average diameter.

The content of light-scattering particles in the inkjet ink is, from the viewpoint of a better effect of improving external quantum efficiency, the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light-scattering particles in the inkjet ink is 100. With respect to parts by mass, it may be 0.1 parts by mass or more, may be 1 part by mass or more, may be 5 parts by mass or more, may be 7 parts by mass or more, may be 10 parts by mass or more, and may be 12 parts by mass or more. The content of light-scattering particles is the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light-scattering particles in the inkjet ink from the viewpoint of excellent discharge stability and a better effect of improving external quantum efficiency. For 100 parts by mass, it may be 60 parts by mass or less, may be 50 parts by mass or less, may be 40 parts by mass or less, may be 30 parts by mass or less, may be 25 parts by mass or less, may be 20 parts by mass or less, and may be 15 parts by mass or less. It may be less than 20%. When the inkjet ink contains a polymer dispersant, the light-scattering particles can be well dispersed even when the content of the light-scattering particles is relatively high (for example, about 60 parts by mass).

The mass ratio of the content of light-scattering particles to the content of luminescent nanocrystal particles (light-scattering particles/luminescent nanocrystal particles) may be 0.01 or more, 0.02 or more, or 0.05 or more from the viewpoint of excellent improvement in external quantum efficiency. It may be 0.07 or more, 0.1 or more, 0.2 or more, and 0.5 or more. The mass ratio (light scattering particles/luminescent nanocrystal particles) may be 5.0 or less, or 2.0 or less, from the viewpoint of better improvement in external quantum efficiency and excellent continuous discharge (ejection stability) during inkjet printing. It may be less than 1.5.

The content of inorganic components in the inkjet ink (for example, the total amount of luminescent nanocrystal particles and light-scattering particles) is determined from the viewpoint of making it easy to obtain an appropriate viscosity as an inkjet ink, including the luminescent nanocrystal particles in the inkjet ink, the organic ligand, With respect to the total content of 100 parts by mass of the photopolymerizable compound, thermosetting resin, and light scattering particles, the amount is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more. The content of inorganic components in the inkjet ink (for example, the total amount of luminescent nanocrystal particles and light-scattering particles) is determined from the viewpoint of making it easy to obtain an appropriate viscosity as an inkjet ink, including the luminescent nanocrystal particles in the inkjet ink, the organic ligand, With respect to the total content of 100 parts by mass of the photopolymerizable compound, thermosetting resin, and light scattering particles, the content is preferably 80 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less. The content of inorganic components in the inkjet ink (for example, the total amount of luminescent nanocrystal particles and light scattering particles) is determined by the amount of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles in the inkjet ink. For a total content of 100 parts by mass, 5 to 80 parts by mass, 10 to 50 parts by mass, or 20 to 40 parts by mass may be added.

The inkjet ink may further contain components other than the components described above, as long as they do not impair the effect of the present invention. Other components include, for example, polymer dispersants, solvents, antioxidants, etc.

[Polymer dispersant]

A polymer dispersant is a polymer compound that has a weight average molecular weight of 750 or more and has a functional group that has affinity for light-scattering particles. The polymer dispersant has the function of dispersing light-scattering particles. The polymer dispersant adsorbs to the light-scattering particles through a functional group having affinity for the light-scattering particles, and disperses the light-scattering particles in the inkjet ink by electrostatic repulsion and/or steric repulsion of the polymer dispersants. The polymer dispersant is preferably bound to the surface of the light-scattering particles and adsorbed to the light-scattering particles, but may be bound to the surface of the light-emitting nanocrystal particles and adsorbed to the light-emitting nanoparticles, or may be free in the inkjet ink.

Functional groups having affinity for light-scattering particles include acidic functional groups, basic functional groups, and nonionic functional groups. The acidic functional group has a dissociable proton and may be neutralized with a base such as an amine or hydroxide ion, and the basic functional group may be neutralized with an acid such as an organic acid or an inorganic acid.

As acidic functional groups, carboxyl group (-COOH), sulfo group (-SO ₃ H), sulfuric acid group (-OSO ₃ H), phosphonic acid group (-PO(OH) ₃ ), phosphoric acid group (-OPO(OH) ₃ ), phosphatase Examples include a pinic acid group (-PO(OH)-) and a mercapto group (-SH).

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.

Nonionic functional groups include hydroxy group, ether group, thioether group, sulfinyl group (-SO-), sulfonyl group (-SO ₂ -), carbonyl group, formyl group, ester group, carbonate ester group, amide group, carbamoyl group, Examples include ureide group, thioamide group, thiouride group, sulfamoyl group, cyano group, alkenyl group, alkynyl group, phosphine oxide group, and phosphine sulfide group.

The polymer dispersant may be a polymer of a single monomer (homopolymer), or may be a copolymer of multiple types of monomers (copolymer). Additionally, the polymer dispersant may be any of random copolymers, block copolymers, or graft copolymers. Additionally, when the polymer dispersant is a graft copolymer, it may be a comb-shaped graft copolymer or a molded graft copolymer. Polymer dispersants include, for example, acrylic resin, polyester resin, polyurethane resin, polyamide resin, polyether, phenol resin, silicone resin, polyurea resin, amino resin, epoxy resin, polyethyleneimine, and polyallylamine. It may be polyamine, polyimide, etc.

As a polymer dispersant, it is also possible to use a commercially available product. As a commercial product, AJINOMOTO FINE-TECHNO CO., INC. The Azisper-PB series manufactured by BYK, the DISPERBYK series and BYK-series manufactured by BYK, and the Efka series manufactured by BASF can be used.

Commercially available polymer dispersants include, for example, "DISPERBYK-130", "DISPERBYK-161", "DISPERBYK-162", "DISPERBYK-163", "DISPERBYK-164", and "DISPERBYK-166" manufactured by BYK, 「DISPERBYK-167」, 「DISPERBYK-168」, 「DISPERBYK-170」, 「DISPERBYK-171」, 「DISPERBYK-174」, 「DISPERBYK-180」, 「DISPERBYK-182」, 「DISPERBYK-183」, 「DISPERBYK -184”, “DISPERBYK-185”, “DISPERBYK-2000”, “DISPERBYK-2001”, “DISPERBYK-2008”, “DISPERBYK-2009”, “DISPERBYK-2020”, “DISPERBYK-2022”, “DISPERBYK-2025” ”, “DISPERBYK-2050”, “DISPERBYK-2070”, “DISPERBYK-2096”, “DISPERBYK-2150”, “DISPERBYK-2155”, “DISPERBYK-2163”, “DISPERBYK-2164”, “BYK-LPN21116” and “BYK-LPN6919”; “EFKA4010”, “EFKA4015”, “EFKA4046”, “EFKA4047”, “EFKA4061”, “EFKA4080”, “EFKA4300”, “EFKA4310”, “EFKA4320”, “EFKA4330” manufactured by BASF, “EFKA4340”, “EFKA4560”, “EFKA4585”, “EFKA5207”, “EFKA1501”, “EFKA1502”, “EFKA1503” and “EFKA PX-4701”; “SOLSPERSE 3000”, “SOLSPERSE 9000” manufactured by THE LUBRIZOL, 「SOLSPERSE 13240」, 「SOLSPERSE 13650」, 「SOLSPERSE 13940」, 「SOLSPERSE 11200」, 「SOLSPERSE 13940」, 「SOLSPERSE 16000」, 「SOLSPERSE 17000」, 「SOLSPERSE 18000」, 「SOLSPERSE 20000」 」, 「SOLSPERSE 21000」, 「SOLSPERSE 24000」, 「SOLSPERSE 26000」, 「SOLSPERSE 27000」, 「SOLSPERSE 28000」, 「SOLSPERSE 32000」, 「SOLSPERSE 32500」, 「SOLSPERSE 32550」, 「SOLSPERSE 32600」, 「SOLSPERSE 33000」 」, 「SOLSPERSE 34750」, 「SOLSPERSE 35100」, 「SOLSPERSE 35200」, 「SOLSPERSE 36000」, 「SOLSPERSE 37500」, 「SOLSPERSE 38500」, 「SOLSPERSE 39000」, 「SOLSPERSE 41000」, 「SOLSPERSE 54000」, 「SOLSPERSE 71000」 ” and 「SOLSPERSE 76500」； AJINOMOTO FINE-TECHNO CO., INC. "Azispur-PB821", "Azispur-PB822", "Azispur-PB881", "PN411" and "PA111"; "TEGO Dispers650", "TEGO Dispers660C", "TEGO Dispers662C" manufactured by EVONIK, 「TEGO Dispers670」, 「TEGO Dispers685」, 「TEGO Dispers700」, 「TEGO Dispers710」 and 「TEGO Dispers760W」；KUSUMOTO CHEMICALS, LTD. Products such as “DISPARON DA-703-50”, “DA-705”, and “DA-725” can be used.

[solvent]

As a solvent, for example, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol dibutyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, Diethyl malonate, dimethyl succinate, diethyl succinate, 1,4-butanediol diacetate, glyceryl triacetate, etc. are mentioned.

The boiling point of the solvent under atmospheric pressure is preferably 150°C or higher, and more preferably 180°C or higher, from the viewpoint of continuous ejection of inkjet ink. In addition, when forming a pixel portion, it is necessary to remove the solvent from the inkjet ink before curing the inkjet ink. Therefore, from the viewpoint of easy removal of the solvent, the boiling point of the solvent under atmospheric pressure is preferably 300° C. or lower.

In the inkjet ink of this embodiment, since the photopolymerizable compound also functions as a dispersion medium, it is possible to disperse light-scattering particles and luminescent nanocrystal particles with a non-solvent agent. In this case, there is an advantage that the process of removing the solvent by drying is unnecessary when forming the pixel portion.

[Antioxidant]

The inkjet ink may further contain an antioxidant. In this case, the quantum yield can be improved and the temporal decrease in quantum yield can be further suppressed. The antioxidant may be, for example, a phosphorous acid ester compound, a thioether compound, etc., and is preferably a phosphorous acid ester compound from the viewpoint of improving the quantum yield and further suppressing a decrease in the quantum yield over time.

The antioxidant may be a phosphorous acid triester compound. The phosphorous acid triester compound may be a compound represented by the following formula (2).

In formula (2), R ¹¹ , R ¹² and R ¹³ each independently represent a monovalent organic group. Two selected from R ¹¹ , R ¹² and R ¹³ may be bonded to each other to form a ring. The monovalent organic group may be, for example, a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include an alkyl group, an aryl group, and an alkenyl group. The number of carbon atoms of the monovalent hydrocarbon group may be 1 to 30 or 4 to 18.

Specific examples of the compound represented by formula (2) include triphenyl phosphite (triphenyl phosphite), 2-ethylhexyl diphenyl phosphite, and diphenyl octyl phosphite.

The phosphorous acid triester compound may be liquid or solid at room temperature (25°C), but preferably satisfies the performance requirements specific to inkjet ink, including compatibility with other components (photopolymerizable compounds, etc.) in inkjet ink. And, from the viewpoint of further suppressing the decrease in quantum yield of inkjet ink, it is liquid at room temperature (25°C). The melting point of the phosphorous acid triester compound may be 20°C or lower, or may be 10°C or lower.

The content of the antioxidant is from the viewpoint that the decline in the quantum yield of the inkjet ink is further suppressed relative to the total content of 100 parts by mass of the luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles in the inkjet ink. It may be 0.01 parts by mass or more, 0.1 parts by mass or more, 1 part by mass or more, and 5 parts by mass or more. Since the decrease in quantum yield can be more effectively suppressed even by adding a small amount, the content of the antioxidant is set to 100 parts by mass of the total content of the luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light scattering particles in the inkjet ink. Preferably it is 10 parts by mass or less, more preferably 7 parts by mass or less, further preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less. When the content of the antioxidant is within the above range, in addition to ensuring better film strength during coating film formation, bleeding of the antioxidant to the surface is further suppressed, and good optical properties can be secured. .

When the inkjet ink contains a photopolymerizable compound, the content of the antioxidant may be 0.01 part by mass or more, or 0.1 part by mass, with respect to 100 parts by mass of the photopolymerizable compound, from the viewpoint of further suppressing the decrease in quantum yield of the inkjet ink. It may be more than 0.5 parts by mass, more than 0.5 parts by mass, more than 1 part by mass, and more than 3 parts by mass. Since the decrease in quantum yield can be more effectively suppressed even by adding a small amount, the content of the antioxidant may be 10 parts by mass or less, 7 parts by mass or less, or 5 parts by mass or less with respect to 100 parts by mass of the photopolymerizable compound. do. When the content of the antioxidant is within the above range, when forming a coating film, it becomes possible to secure better film strength, further suppress bleeding of the antioxidant to the surface, and ensure good optical properties. There is a tendency.

The viscosity of the inkjet ink described above at the ink temperature (e.g., temperature range of 25 to 40°C) during inkjet printing may be 2 mPa·s or more, for example, from the viewpoint of ejection stability during inkjet printing. , may be 5 mPa·s or more, and may be 7 mPa·s or more. The viscosity of the inkjet ink at the ink temperature (for example, a temperature range of 25 to 40°C) during inkjet printing may be 17 mPa·s or less, and may be 15 mPa·s, from the viewpoint of obtaining an inkjet ink suitable for forming a pixel portion. It may be less than or equal to 12 mPa·s. The viscosity at the ink temperature (e.g., temperature range of 25 to 40°C) during inkjet printing of inkjet ink is, for example, 2 to 17 mPa·s, 2 to 15 mPa·s, 2 to 12 mPa·s, It may be 5 to 17 mPa·s, 5 to 15 mPa·s, 5 to 12 mPa·s, 7 to 17 mPa·s, 7 to 15 mPa·s, or 7 to 12 mPa·s. For example, the viscosity of the inkjet ink at 40°C may be within the above range. In this specification, the viscosity of inkjet ink is the viscosity measured by, for example, an E-type viscosity meter.

When the viscosity of the inkjet ink at the ink temperature during inkjet printing is 2 mPa·s or more, the meniscus shape of the inkjet ink at the tip of the ink discharge hole of the discharge head is stable, so the discharge control of the inkjet ink (e.g. For example, control of the discharge amount and timing of discharge) becomes easy. On the other hand, when the viscosity of the inkjet ink at the ink temperature during inkjet printing is 17 mPa·s or less, the inkjet ink can be discharged smoothly from the ink discharge hole, making it easy to form the pixel portion.

The surface tension of the inkjet ink is preferably a surface tension appropriate for the inkjet method, and specifically, it is preferably in the range of 20 to 40 mN/m, and more preferably 25 to 35 mN/m. By keeping the surface tension within the range, discharge control (for example, control of the discharge amount and timing of discharge) becomes easy and the occurrence of flight bending can be suppressed. Additionally, flight bending refers to a deviation of 30 μm or more in the landing position of the inkjet ink from the target position when inkjet ink is ejected from the ink discharge hole. When the surface tension is 40 mN/m or less, the meniscus shape at the tip of the ink discharge hole becomes stable, so control of the discharge of inkjet ink (for example, control of the discharge amount and timing of discharge) becomes easy. On the other hand, when the surface tension is 20 mN/m or more, the area around the ink discharge hole can be prevented from being contaminated with inkjet ink, and thus the occurrence of flight bending can be suppressed. In other words, the pixel portion is not accurately impacted in the pixel portion formation area where it is supposed to hit and a pixel portion with insufficient inkjet ink filling occurs, or the inkjet ink lands on the pixel portion formation area (or pixel portion) adjacent to the pixel portion formation area where it is supposed to hit. Therefore, color reproducibility does not deteriorate. The inkjet ink may have the above surface tension at the ink temperature (for example, a temperature range of 25 to 40°C) during inkjet printing, or may have the above surface tension at 40°C.

The inkjet ink of this embodiment is preferably applied to a piezo jet inkjet recording device using a mechanical ejection mechanism using a piezoelectric element. With the piezo jet method, the inkjet ink is not momentarily exposed to high temperatures during ejection. Therefore, it is difficult for the luminescent nanocrystal particles to deteriorate, and the expected luminescent properties can be more easily obtained in the pixel portion (light conversion layer).

From the viewpoint of suppressing the inkjet ink coating film from absorbing moisture in the air and suppressing the luminescence (e.g., fluorescence) of the luminescent nanocrystal particles (quantum dots, etc.) from decreasing over time, in this embodiment, , it is preferable that the coating film of inkjet ink is alkali insoluble. That is, it is preferable that the inkjet ink of this embodiment is an inkjet ink capable of forming an alkali-insoluble coating film. Such inkjet ink can be obtained by using an alkali-insoluble photopolymerizable compound and/or an alkali-insoluble thermosetting resin as the photopolymerizable compound and/or thermosetting resin. The fact that the inkjet ink coating film is alkali insoluble means that the dissolution amount of the inkjet ink coating film at 25°C in a 1 mass% potassium hydroxide aqueous solution is 30% by mass or less, based on the total mass of the inkjet ink coating film. do. The amount of dissolution of the inkjet ink coating film is preferably 10 mass% or less, and more preferably 3 mass% or less. In addition, the inkjet ink is an inkjet ink capable of forming an alkali-insoluble coating film by measuring the amount of dissolution of a coating film with a thickness of 1 μm obtained by applying the inkjet ink to a substrate and then drying it at 80° C. for 3 minutes. You can check it.

＜Manufacturing method of inkjet ink＞

The inkjet ink of the above-described embodiment is obtained, for example, by mixing the components of the above-described inkjet ink and performing a dispersion treatment.

The method for producing inkjet ink 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 nanocrystal particles. Equipped with As the luminescent nanocrystal particles, luminescent nanocrystal particles having an organic ligand on their surface are used. That is, the luminescent nanocrystal particle dispersion further contains an organic ligand. 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/or a thermosetting resin, and in the second step, the photopolymerizable compound and/or a thermosetting resin may be further mixed. According to this method, light-scattering particles can be sufficiently dispersed. As a result, the optical properties of the pixel portion can be improved and inkjet ink with excellent ejection stability can be easily obtained.

In the step of preparing a dispersion of light-scattering particles, the light-scattering particles, if necessary, a polymer dispersant, and a photopolymerizable compound and/or thermosetting resin are mixed and subjected to dispersion treatment to prepare a dispersion of light-scattering particles. You can do it. Mixing and dispersion treatment may be performed using a dispersing device such as a bead mill, paint conditioner, planetary stirrer, or jet mill. From the viewpoint of improving the dispersibility of the light-scattering particles and making it easy to adjust the average particle diameter of the light-scattering particles to a desired range, it is preferable to use a bead mill or paint conditioner. By mixing the light-scattering particles and the polymer dispersant before mixing the luminescent nanocrystal particles and the light-scattering particles, the light-scattering particles can be more sufficiently dispersed. As a result, excellent discharge stability and excellent external quantum efficiency can be more easily obtained.

The method for producing inkjet ink may further include a step of preparing a dispersion of luminescent nanocrystal particles containing luminescent nanocrystal particles and an organic solvent before the second step. In this case, in the second step, the dispersion of light-scattering particles and the dispersion of luminescent nanocrystal particles are mixed. In the step of preparing a dispersion of luminescent nanocrystal particles, the luminescent nanocrystal particle dispersion may be prepared by mixing the luminescent nanocrystal particles and an organic solvent and performing a dispersion treatment. Mixing and dispersion treatment may be performed using a dispersing device such as a bead mill, paint conditioner, planetary stirrer, or jet mill. From the viewpoint of improving the dispersibility of the luminescent nanocrystal particles and making it easy to adjust the average particle diameter of the luminescent nanocrystal particles to a desired range, it is preferable to use a bead mill, paint conditioner, or jet mill. According to this method, luminescent nanocrystal particles can be sufficiently dispersed. As a result, the optical properties of the pixel portion can be improved and inkjet ink with excellent ejection stability can be easily obtained. In the above step, the dispersion of luminescent nanocrystal particles may further contain a photopolymerizable compound and/or a thermosetting resin.

In this manufacturing method, the organic solvent may be blended in the first step or in the second step. That is, the first step may be a step of preparing a dispersion of light-scattering particles containing light-scattering particles, a polymer dispersant, and an organic solvent, and the second step may be a step of preparing a dispersion of light-scattering particles and a luminescent nano It may be a process of mixing crystal particles and an organic solvent.

The method for producing inkjet ink may further include a step of mixing an organic solvent and a thermosetting resin and/or a photopolymerizable compound to prepare a solution containing the thermosetting resin and/or a photopolymerizable compound. In this case, in the second step, the solution containing the light scattering particle dispersion, the luminescent nanocrystal particle dispersion, the thermosetting resin and/or the photopolymerizable compound prepared in the above-described process, and an organic solvent may be mixed. That is, the second step may be a step of mixing a solution containing the light-scattering particle dispersion, the luminescent nanocrystal particle dispersion, the thermosetting resin and/or the photopolymerizable compound, and the organic solvent.

In this production method, components other than those described above may be further used. In this case, the other components may be contained in the luminescent nanocrystal particle dispersion or may be contained in the light-scattering particle dispersion. Additionally, other components may be mixed into the composition obtained by mixing the luminescent nanocrystal particle dispersion and the light-scattering particle dispersion.

＜Inkjet ink set＞

The inkjet ink set of one embodiment includes the inkjet ink of the above-described embodiment. In addition to the inkjet ink (luminescent inkjet ink) of the embodiment described above, the inkjet ink set may include an inkjet ink (non-luminescent inkjet ink) that does not contain luminescent nanocrystal particles. The non-luminescent inkjet ink may be a conventionally known inkjet ink, or may have the same composition as the inkjet ink (luminescent inkjet ink) of the above-described embodiment, except that it does not contain luminescent nanocrystal particles.

Since the non-luminescent inkjet ink does not contain luminescent nanocrystal particles, when light is incident on the pixel portion formed by the non-luminescent inkjet ink (the pixel portion containing the cured product of the non-luminescent inkjet ink), the light is emitted from the pixel portion. The emitted light has approximately the same wavelength as the incident light. Therefore, non-luminescent inkjet ink is suitably 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) with a wavelength in the range of 420 to 480 nm, the pixel portion formed by non-luminescent inkjet ink may be a blue pixel portion.

Non-luminescent inkjet ink preferably contains light-scattering particles. When the non-luminescent inkjet ink contains light-scattering particles, the pixel portion formed by the non-luminescent inkjet ink can scatter the light incident on the pixel portion, thereby changing the viewing angle of the light emitted from the pixel portion. The difference in light intensity can be reduced.

＜Light conversion layer and color filter, and their manufacturing method＞

Hereinafter, details of the light conversion layer and color filter obtained by using the inkjet ink set of the above-described embodiment will be described with reference to the drawings. In addition, in the following description, the same symbol is used for the same or equivalent elements, and overlapping descriptions are omitted.

1 is a schematic cross-sectional view of a color filter according to one 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 a light-shielding portion 20.

The light conversion layer 30 is a pixel portion 10 and includes a first pixel portion 10a, a second pixel portion 10b, and a third pixel portion 10c. The first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c are arranged in a grid so that this order is repeated. The light blocking unit 20 is located between neighboring pixel units, that is, between the first pixel unit 10a and the second pixel unit 10b, between the second pixel unit 10b and the third pixel unit 10c, It is installed between the third pixel portion 10c and the first pixel portion 10a. In other words, these neighboring pixel parts are spaced apart by the light blocking part 20.

The first pixel portion 10a and the second pixel portion 10b are each luminescent pixel portion (luminescent pixel portion) containing a cured product of the inkjet ink of the above-described embodiment. The cured product contains luminescent nanocrystal particles, a curing component, and light-scattering particles. The curing component is a component obtained by polymerization of a photopolymerizable compound and/or curing (polymerization, crosslinking, etc.) of a thermosetting resin, and includes a polymer of a photopolymerizable compound and/or a cured body of a thermosetting resin. That is, the first pixel portion 10a includes the first curing component 13a, the first luminescent nanocrystal particles 11a and the first light scattering particles 12a respectively dispersed in the first curing component 13a. Includes. Likewise, the second pixel portion 10b includes a second curing component 13b, second luminescent nanocrystal particles 11b and second light scattering particles 12b respectively dispersed in the second curing component 13b. Includes. In the first pixel portion 10a and the second pixel portion 10b, the first curing component 13a and the second curing component 13b may be the same or different, and the first light scattering particles 12a and the second curing component 13b may be the same or different. The two light-scattering particles 12b may be the same or different.

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

The total content of luminescent nanocrystal particles and organic ligands in the luminescent pixel portion is 21% by mass or more, 25% by mass or more, 27% by mass or more, 30% by mass or more, 35% by mass or more, based on the total mass of the luminescent pixel portion. It may be % by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more, and may be 70% by mass or less, 65% by mass or less, 60% by mass or less, or 55% by mass or less.

The content of light scattering particles in the light-emitting pixel portion may be 0.1% by mass or more, or 1% by mass or more, based on the total mass of the light-emitting pixel portion, from the viewpoint of a better effect of improving external quantum efficiency, 3 It may be more than % by mass, and may be more than 5% by mass. The content of light scattering particles may be 60% by mass or less, or 50% by mass or less, based on the total mass of the light-emitting pixel portion, from the viewpoint of a better effect of improving external quantum efficiency and excellent reliability of the pixel portion, It may be 40% by mass or less, and may be 30% by mass or less.

The third pixel portion 10c is a non-luminescent pixel portion (non-luminescent pixel portion) containing a cured product of the non-luminescent inkjet ink described above. The cured product does not contain luminescent nanocrystal particles, but contains light-scattering particles and a curing component. The curing component is, for example, a component obtained by polymerization of a photopolymerizable compound and/or curing (polymerization, crosslinking, etc.) of a thermosetting resin, and includes a polymer of a photopolymerizable compound and/or a cured body of a thermosetting resin. That is, the third pixel portion 10c contains the third curing component 13c and the third light scattering particles 12c dispersed in the third curing component 13c. The third light-scattering particles 12c may be the same as or different from the first light-scattering particles 12a and the second light-scattering particles 12b.

For example, the third pixel portion 10c has a transmittance of 30% or more for light with a wavelength in the range of 420 to 480 nm. Therefore, the third pixel portion 10c functions as a blue pixel portion when using a light source that emits light with a wavelength in the range of 420 to 480 nm. Additionally, the transmittance of the third pixel portion 10c can be measured using a microspectroscopy device.

The content of light scattering particles in the non-luminous pixel portion may be 1% by mass or more, based on the total mass of the non-luminous pixel portion, from the viewpoint of further reducing the light intensity difference in the viewing angle, and may be 5% by mass. It may be % or more, and may be 10% by mass or more. The content of light scattering particles may be 80% by mass or less, 75% by mass or less, or 70% by mass or less, based on the total mass of the non-light-emitting pixel portion, from the viewpoint of further reducing light reflection.

The thickness of the pixel portion (the first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c) is, for example, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, Alternatively, it may be 6 μm or more, 30 μm or less, or 20 μm or less.

The light blocking portion 20 is a so-called black matrix that is installed for the purpose of separating adjacent pixel portions from each other, preventing color mixing, and preventing leakage of light 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 product of a resin composition containing light-shielding particles such as carbon particles, metal oxides, inorganic pigments, and organic pigments in a binder polymer, etc. can be used. Examples of the binder polymer used here include one or a mixture of two or more resins such as polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, and cellulose, photosensitive resin, and O/W. An emulsion-type resin composition (for example, an emulsion of reactive silicone) can be used. The thickness of the light-shielding portion 20 may be, for example, 0.5 μm or more and 10 μm or less.

The base material 40 is a transparent base material having light transparency, for example, a transparent glass substrate such as quartz glass, PYREX (registered trademark) glass, synthetic quartz plate, a transparent resin film, and a transparent flexible base material such as an optical resin film. etc. can be used. Among these, it is preferable to use a glass substrate made of alkali-free glass that does not contain an alkali component in the glass. Specifically, "7059 glass", "1737 glass", "EAGLE 200" and "EAGLE -11” is appropriate. These are materials with a low coefficient of thermal expansion and are excellent in dimensional stability and workability in high-temperature heat treatment.

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

The manufacturing method of the light conversion layer 30 (color filter 100) according to one embodiment includes a process of forming a light blocking portion 20 on a substrate 40 (light blocking portion forming process), and a process of forming the light blocking portion 20 on a substrate 40. A process of arranging the inkjet ink of the above-described embodiment by an inkjet method (placement process) in the pixel portion formation area partitioned by the light-shielding portion 20 on the image, and a process of curing the inkjet ink (curing process). I'm doing it.

In the light-shielding portion forming process, the light-shielding portion 20 is formed in a pattern shape (for example, a grid shape). The method of forming the light-shielding portion 20 includes forming a thin film of a metal such as chrome or a thin film of a resin composition containing light-shielding particles on one surface of the substrate 40, and patterning this thin film. I can hear it. The metal thin film can be formed by, for example, sputtering, vacuum deposition, etc. A thin film of a resin composition containing light-shielding particles can be formed by methods such as coating or printing, for example. Methods for performing patterning include photolithography and the like.

In the placement process, inkjet ink is selectively placed in the pixel portion formation area (area on the base 40 where the light-shielding portion 20 is not formed (opening portion of the light-shielding portion 20)) using the inkjet method ( attached). Examples of the inkjet method include the bubble jet (registered trademark) method using an electric heat converter as an energy generating element, or the piezo jet method using a piezoelectric element.

In the curing process, the inkjet ink disposed in the batch process is cured by irradiation of active energy rays or heating.

When curing inkjet by irradiation of active energy rays (for example, ultraviolet rays), for example, a mercury lamp, metal halide lamp, xenon lamp, LED, etc. may be used as a light source. The wavelength of the light to be irradiated may be, for example, 200 nm or more or 440 nm or less. For example, the exposure amount may be 10 mJ/cm ² or more and may be 4000 mJ/cm ² or less.

When curing inkjet ink by heating, the heating temperature may be, for example, 110°C or higher or 250°C or lower. The heating time may be, for example, 10 minutes or more or 120 minutes or less.

When the inkjet ink contains a solvent (organic solvent), the manufacturing method of this embodiment may further include a step of volatilizing the solvent (volatilization step). The volatilization process is performed, for example, between the batch process and the curing process. In the volatilization process, the solvent is volatilized by heating the inkjet ink, for example. The heating temperature may be, for example, 50°C or higher or 150°C or lower. The heating time may be, for example, 1 minute or more, 3 minutes or more, or 30 minutes or less.

In the volatilization process, the solvent (organic solvent) may be volatilized by drying under reduced pressure (reduced pressure drying). The conditions for reduced pressure drying may generally be 3 to 30 minutes at 20 to 30°C under a pressure of 1.0 to 500 Pa from the viewpoint of controlling the composition of the ink composition.

Above, one embodiment of the color filter, the light conversion layer, and their manufacturing method has been described, but the present invention is not limited to the above embodiment.

For example, the light conversion layer is a pixel portion that includes a cured product of a luminescent inkjet ink containing blue luminescent nanocrystal particles instead of the third pixel portion 10c or in addition to the third pixel portion 10c. (blue pixel portion) may be provided. Additionally, the light conversion layer may be provided with a pixel portion (for example, a yellow pixel portion) containing a cured product of luminescent inkjet ink containing nanocrystal particles that emit light of colors other than red, green, and blue. . In these cases, it is preferable that each of the luminescent nanocrystal particles contained in each pixel portion of the light conversion layer has a maximum absorption wavelength in the same wavelength range.

Moreover, at least a part of the pixel portion of the light conversion layer may contain a cured product of a composition containing pigments other than luminescent nanocrystal particles.

In addition, the color filter may be provided with an ink-repelling layer made of a material having ink-repelling properties and having a width narrower than that of the light-shielding portion, on the pattern of the light-shielding portion. In addition, instead of providing an ink repellent layer, a photocatalyst-containing layer as a wettability variable layer is formed in a solid shape in the area including the pixel portion formation area, and then the photocatalyst-containing layer is irradiated with light through a photomask and exposed. By doing this, the ink-friendly property of the pixel portion formation area may be selectively increased. Examples of photocatalysts include titanium oxide and zinc oxide.

Additionally, the color filter may be provided with an ink-receiving layer containing hydroxypropyl cellulose, polyvinyl alcohol, gelatin, etc. between the substrate and the pixel portion.

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

Additionally, the pixel portion of the light conversion layer of the present embodiment may further contain, in addition to the above-described luminescent nanocrystal particles, a pigment having substantially the same color as the luminescent color of the luminescent nanocrystal particles. Since the pigment is contained in the pixel portion, the pigment may be contained in the inkjet ink.

In addition, one or two types of luminescent pixel portions among the red pixel portion (R), green pixel portion (G), and blue pixel portion (B) in the light conversion layer of the present embodiment do not contain luminescent nanocrystal particles. Instead, it may be used as a pixel portion containing a colorant. As the colorant that can be used here, a known colorant can be used. For example, the colorant used in the red pixel portion R includes a diketopyrrolopyrrole pigment and/or anionic red organic dye. As a coloring material used in the green pixel portion G, at least one selected from the group consisting of a halogenated copper phthalocyanine pigment, a phthalocyanine-based green dye, a mixture of a phthalocyanine-based blue dye, and an azo-based yellow organic dye. Colorants used in the blue pixel portion (B) include ε-type copper phthalocyanine pigments and/or cationic blue organic dyes. When included in the light conversion layer, the amount of these colorants used is 1 to 5% by mass based on the total mass of the pixel portion (cured product of inkjet ink) from the viewpoint of preventing a decrease in transmittance. desirable.

Example

Hereinafter, the present invention will be described in detail through examples. However, the present invention is not limited to the following examples. In addition, all materials used in the examples were those in which argon gas was introduced and dissolved oxygen was replaced with argon gas. As for titanium oxide, before mixing, it was heated to 175°C for 4 hours under reduced pressure of 1 mmHg and allowed to cool in an argon gas atmosphere. The liquid material used in the examples was dehydrated in advance with Molecular Sieve 3A for more than 48 hours before mixing.

[Preparation of organic ligands for InP/ZnSeS/ZnS nanocrystal particles]

Polyethylene glycol|average Mn400|(manufactured by Sigma-Aldrich) was put into the flask, and succinic anhydride (manufactured by Sigma-Aldrich) in the same molar amount as polyethylene glycol|average Mn400|(manufactured by Sigma-Aldrich) was added to it while stirring in a nitrogen gas environment. . The internal temperature of the flask was raised to 80°C and stirred for 8 hours to obtain organic ligand 1 represented by the following formula (A-1) as a pale yellow viscous oil.

Polyethylene glycol|average Mn750|(manufactured by Sigma-Aldrich) was put into the flask, and succinic anhydride (manufactured by Sigma-Aldrich) in the same molar amount as polyethylene glycol|average Mn750|(manufactured by Sigma-Aldrich) was added to it while stirring in a nitrogen gas environment. . The internal temperature of the flask was raised to 80°C and stirred for 8 hours to obtain organic ligand 2 represented by the following formula (A-2) as a pale yellow viscous oil.

With reference to Japanese Patent Laid-Open No. 2002-121549, organic ligand 3 (triethylene glycol monomethyl ether ester of 3-mercaptopropanoic acid) represented by the following formula (A-3) Captopropionate (TEGMEMP)) was synthesized.

After JEFAMINE M-1000 (manufactured by Huntsman) was added to the flask, succinic anhydride (manufactured by Sigma-Aldrich) in the same molar amount as JEFAMINE M-1000 was added thereto while stirring in a nitrogen gas environment. The internal temperature of the flask was raised to 80°C and stirred for 8 hours to obtain comparative ligand 1 represented by the following formula (B) as a light yellow viscous oil.

As a result of measuring the weight average molecular weight (Mw) of the above ligands in terms of polystyrene by GPC measurement using HLC-8320 manufactured by TOSOH CORPORATION, the Mw of organic ligand 1 was 597, the Mw of organic ligand 2 was 906, and the Mw of organic ligand 3 was 597. The Mw was 273, and the Mw of the comparative example ligand 1 was 1191.

＜Preparation of red-emitting InP/ZnSeS/ZnS nanocrystal particle dispersion＞

[Preparation of indium laurate solution]

10 g of 1-octadecene (ODE), 146 mg (0.5 mmol) of indium acetate, and 300 mg (1.5 mmol) of lauric acid were added to the reaction flask to obtain a mixture. A clear solution (indium laurate solution) was obtained by heating the mixture to 140°C for 2 hours under vacuum. This solution was kept in the glove box at room temperature until needed. Additionally, indium laurate has low solubility at room temperature and is prone to precipitation, so when using an indium laurate solution, the precipitated indium laurate in the solution (ODE mixture) is heated to about 90°C to form a transparent solution. After that, the desired amount was measured and used.

[Fabrication of red luminescent nanocrystal particle core (InP core)]

5 g of trioctylphosphine oxide (TOPO), 1.46 g (5 mmol) of indium acetate, and 3.16 g (15.8 mmol) of lauric acid were added to the reaction flask to obtain a mixture. The mixture was heated at 160°C for 40 minutes in a nitrogen (N ₂ ) environment and then heated at 250°C for 20 minutes under vacuum. Subsequently, the reaction temperature (temperature of the mixture) was raised to 300°C in a nitrogen (N ₂ ) environment. At this temperature, a mixture of 3 g of 1-octadecene (ODE) and 0.25 g (1 mmol) of tris(trimethylsilyl)phosphine was quickly introduced into the reaction flask, and the reaction temperature was maintained at 260°C. After 5 minutes, the reaction was stopped by removing the heater, and the obtained reaction solution was cooled to room temperature. Then, 8 ml of toluene and 20 ml of ethanol were added to the reaction solution in the glove box. Subsequently, centrifugation was performed to precipitate InP nanocrystal particles, and then InP nanocrystal particles were obtained by decanting the supernatant. Subsequently, the obtained InP nanocrystal particles were dispersed in hexane. As a result, a dispersion (hexane dispersion) containing 5% by mass of InP nanocrystal particles was obtained.

The hexane dispersion of InP nanocrystal particles obtained above and the indium laurate solution were injected into a reaction flask to obtain a mixture. The injection amounts of the hexane dispersion of InP nanocrystal particles and the indium laurate solution were adjusted to 0.5 g (25 mg of InP nanocrystal particles) and 5 g (178 mg of indium laurate), respectively. After the mixture was left standing at room temperature under vacuum for 10 minutes, the inside of the flask was returned to normal pressure with nitrogen gas, the temperature of the mixture was raised to 230°C, and the mixture was maintained at that temperature for 2 hours to remove hexane from the inside of the flask. Next, the temperature inside the flask was raised to 250°C, a mixture of 3 g of 1-octadecene (ODE) and 0.03 g (0.125 mmol) of tris(trimethylsilyl)phosphine was quickly introduced into the reaction flask, and the reaction temperature was set to 230°C. maintained. After 5 minutes, the reaction was stopped by removing the heater, and the obtained reaction solution was cooled to room temperature. Next, 8 ml of toluene and 20 ml of ethanol were added to the reaction solution in the glove box. Subsequently, centrifugation is performed to precipitate the InP nanocrystal particles (InP core), which become the core of the red luminescent InP/ZnSeS/ZnS nanocrystal particles, and then the InP nanocrystal particles (InP core) are separated by tilting the supernatant. got it Next, the obtained InP nanocrystal particles (InP core) were dispersed in hexane to obtain a dispersion (hexane dispersion) containing 5% by mass of InP nanocrystal particles (InP core).

[Formation of the shell of red luminescent nanocrystal particles (ZnSeS/ZnS shell)]

After adding 2.5 g of the hexane dispersion of InP nanocrystal particles (InP core) obtained above to the reaction flask, 0.7 g of oleic acid was added to the reaction flask at room temperature, and the temperature was raised to 80°C and maintained for 2 hours. Next, 14 mg of diethylzinc, 8 mg of bis(trimethylsilyl)selenide, and 7 mg of hexamethyldisilatian (ZnSeS precursor solution) dissolved in 1 ml of ODE were added dropwise to this reaction mixture, heated to 200°C, and maintained for 10 minutes. A ZnSeS shell with a thickness of 0.5 monolayer was formed.

Next, the temperature was raised to 140°C and maintained for 30 minutes. Next, into this reaction mixture, a ZnS precursor solution obtained by dissolving 69 mg of diethyl zinc and 66 mg of hexamethyldisilatian in 2 ml of ODE was added dropwise, the temperature was raised to 200°C, and held for 30 minutes to form a 2-thick monolayer. A ZnS shell was formed. After 10 minutes of dropwise addition of the ZnS precursor solution, the reaction was stopped by removing the heater. Then, the reaction mixture was cooled to room temperature, and the obtained white precipitate was removed by centrifugation, thereby forming a transparent nanocrystal particle dispersion containing red luminescent InP/ZnSeS/ZnS nanocrystal particles (ODE of InP/ZnSeS/ZnS nanocrystal particles). dispersion) was obtained.

＜Preparation of green luminescent InP/ZnSeS/ZnS nanocrystal particle dispersion＞

[Synthesis of green luminescent nanocrystal particle core (InP core)]

5 g of trioctylphosphine oxide (TOPO), 1.46 g (5 mmol) of indium acetate, and 3.16 g (15.8 mmol) of lauric acid were added to the reaction flask to obtain a mixture. The mixture was heated at 160°C for 40 minutes in a nitrogen (N ₂ ) environment and then at 250°C for 20 minutes under vacuum. Subsequently, the reaction temperature (temperature of the mixture) was raised to 300°C in a nitrogen (N ₂ ) environment. At this temperature, a mixture of 3 g of 1-octadecene (ODE) and 0.25 g (1 mmol) of tris(trimethylsilyl)phosphine was quickly introduced into the reaction flask, and the reaction temperature was maintained at 260°C. After 5 minutes, the reaction was stopped by removing the heater, and the obtained reaction solution was cooled to room temperature. Then, 8 ml of toluene and 20 ml of ethanol were added to the reaction solution in the glove box. Subsequently, centrifugation was performed to precipitate InP nanocrystal particles (InP core), and then InP nanocrystal particles (InP core) were obtained by decanting the supernatant. Next, the obtained InP nanocrystal particles (InP core) were dispersed in hexane to obtain a dispersion (hexane dispersion) containing 5% by mass of InP nanocrystal particles (InP core).

[Synthesis of green luminescent nanocrystal particle shell (ZnSeS/ZnS shell)]

After adding 2.5 g of the hexane dispersion of InP nanocrystal particles (InP core) obtained above to the reaction flask, 0.7 g of oleic acid was added to the reaction flask at room temperature, and the temperature was raised to 80°C. Then, into this reaction mixture, 14 mg of diethylzinc, 8 mg of bis(trimethylsilyl)selenide, and 7 mg of hexamethyldisilatian (ZnSeS precursor solution) dissolved in 1 ml of ODE were added dropwise to form a ZnSeS shell with a thickness of 0.5 monolayer. I ordered it.

After dropping the ZnSeS precursor solution, the reaction temperature was maintained at 80°C for 10 minutes. Next, the temperature was raised to 140°C and maintained for 30 minutes. Next, into this reaction mixture, a ZnS precursor solution obtained by dissolving 69 mg of diethyl zinc and 66 mg of hexamethyldisilatian in 2 ml of ODE was added dropwise to form a ZnS shell with a thickness of 2 monolayers. 10 minutes after the ZnS precursor solution was added dropwise, the reaction was stopped by removing the heater. The reaction mixture was then cooled to room temperature, and the resulting white precipitate was removed by centrifugation to obtain a transparent nanocrystal particle dispersion (ODE dispersion) in which green luminescent InP/ZnSeS/ZnS nanocrystal particles were dispersed.

[Preparation of green luminescent nanocrystal particle dispersion 1 (InP/ZnSeS/ZnS nanocrystal particle dispersion) by ligand exchange]

To the green luminescent nanocrystal particle dispersion (ODE dispersion of InP/ZnSeS/ZnS nanocrystal particles) obtained above, twice the amount of PGMEA (propylene glycol monomethyl ether) was added, and the nanocrystal particles were once agglomerated, Ligand exchange was carried out by adding 20 parts by mass of organic ligand 1 to 100 parts by mass of the total content of the luminescent nanocrystal particles in the dispersion and the ligand during synthesis (solid content in the above ODE dispersion) and then stirring at 80°C for 2 hours. carried out. The nanocrystal particles that had aggregated before the ligand exchange dispersed again as the ligand was exchanged. Next, by adding 4 times the amount of heptane to the ligand exchanged nanocrystal particle dispersion, the nanocrystal particles were again aggregated and precipitated by centrifugation, and then the supernatant was decanted and dried under vacuum to form nanocrystal particles ( InP/ZnSeS/ZnS nanocrystal particles modified with the above organic ligand) were obtained.

By measuring the weight loss of dried nanocrystal particles at 150°C to 500°C using TG/DTA6200 manufactured by HITACHI HIGH-TECH SCIENCE CORPORAION, the ratio of organic ligands in the luminescent nanocrystal particles (luminescent nanocrystal particles and organic ligands) was determined. As a result of calculating the organic ligand content relative to the total content of 100 parts by mass, it was 26 parts by mass.

The obtained nanocrystal particles (InP/ZnSeS/ZnS nanocrystal particles modified with the above organic ligand) were treated with 1,6-hexanediol diacrylate (manufactured by SHIN-NAKAMURA CHEMICAL CO., LTD., brand name: NK Ester A-HD). By dispersing in -N (hereinafter also referred to as “HDDA”), green luminescent nanocrystal particle dispersion 1 was obtained. The total content of luminescent nanocrystal particles and organic ligands in the green luminescent nanocrystal particle dispersion was 50% by mass.

[Production of InP/ZnSeS/ZnS nanocrystal particle dispersions 2 to 5 by ligand exchange]

Luminescent nanocrystal particle dispersions 2 to 5 were obtained by using the same method as the InP/ZnSeS/ZnS nanocrystal particle dispersion 1 above and adjusting the organic ligand species and organic ligand ratio used as shown in Table 1. The amount of organic ligand added during ligand exchange relative to the total content of luminescent nanocrystal particles and the ligand during synthesis is 50 parts by mass for luminescent nanocrystal particle dispersion 2 and 30 parts by mass for luminescent nanocrystal particle dispersion 3. , 20 parts by mass in luminescent nanocrystal particle dispersion 4, 30 parts by mass in luminescent nanocrystal particle dispersion 5, 30 parts by mass in luminescent nanocrystal particle dispersion 6, and 30 parts by mass in luminescent nanocrystal particle dispersion 7.

[Table 1]

<Preparation of light scattering particle dispersion>

In a container filled with argon gas, 27.5 g of titanium oxide (brand name: CR-60-2, manufactured by ISHIHARA SANKYO KAISHA, LTD., average particle diameter (volume average diameter): 210 nm) and a polymer dispersant (brand name: Azisper- After mixing 1.0 g of PB-821 (manufactured by AJINOMOTO FINE-TECHNO CO., INC.) with 21.5 g of HDDA, a light scattering particle dispersion medium, zirconia beads (diameter: 1.25 mm) were added to the resulting mixture, and paint conditioner was added. The mixture was dispersed by shaking for 2 hours, and the zirconia beads were removed using a polyester mesh filter to obtain light-scattering particle dispersion 1 (titanium oxide content: 55% by mass).

[Preparation of inkjet ink]

<Example 1>

7.0 g of luminescent nanocrystal particle dispersion 1, 0.9 g of light scattering particle dispersion 1, and a photopolymerization initiator (phenyl (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by IGM Resin, brand name) ：After mixing 0.3 g of Omnirad TPO)), 0.3 g of antioxidant ADKSTAB C, and 1.5 g of HDDA in a container filled with argon gas, the mixture was filtered with a hole diameter of 5 μm in a glove box. Filtered. Additionally, argon gas was introduced into the container containing the obtained filtrate, and the inside of the container was saturated with argon gas. Then, the pressure was reduced to remove the argon gas, thereby obtaining the inkjet ink of Example 1. Overall inkjet ink The total content (non-volatile matter concentration) of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, and light-scattering particles in the inkjet ink based on mass, and the luminescent nanocrystal particles, organic ligands, and photopolymerizable compounds in the inkjet ink, and the total content of the luminescent nanocrystal particles and organic ligands relative to 100 parts by mass of the total content of the light-scattering particles were as shown in Table 2.

<Examples 2 to 5, Comparative Examples 1 to 2, Reference Examples 1 to 2>

The total content (non-volatile matter concentration) of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, and light-scattering particles in the inkjet ink based on the total mass of the inkjet ink, and the luminescent nanocrystal particles, organic ligands, in the inkjet ink, The total content of the photopolymerizable compound and the light scattering particles was adjusted so that the total content of the luminescent nanocrystal particles and the organic ligand relative to 100 parts by mass was the amount shown in Table 2, Examples 2 to 5, Comparative Examples 1 to 2, and The inkjet inks of Reference Examples 1 and 2 were obtained. Regarding Reference Example 2, diethylene glycol diethyl ether was used as a solvent and the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, and light scattering particles in the inkjet ink was adjusted to 25% by mass.

[Evaluation of inkjet ink viscosity and thickening in atmospheric atmosphere]

The viscosity of the inkjet inks of Examples and Comparative Examples was evaluated by measuring the viscosity at 40°C using an E-type viscosity meter. In the evaluation of viscosity, when the viscosity at 40°C is 17.0 mPa·s or less, it is evaluated to have a viscosity appropriate for the formation of a pixel portion, and when the viscosity at 40°C exceeds 17.0 mPa·s, the viscosity is evaluated to be appropriate for the formation of a pixel portion. It was evaluated that it did not have an appropriate viscosity.

Evaluation of thickening in an atmospheric atmosphere (thickening when exposed to air) was performed by dropping a certain amount of the inkjet ink of Examples and Comparative Examples onto a petri dish and tilting the petri dish after 3 minutes. When the petri dish was tilted, if it flowed without a problem, it was evaluated as no thickening, no flow, or if there was even a part of it that changed to a gel shape, it was evaluated as thickening. Evaluation of thickening was conducted in a clean room with constant humidity (humidity 50 ± 2% RH).

[Evaluation of optical properties]

[Production of samples for evaluation]

Each inkjet ink was applied in the air using a spin coater so that the film thickness was 10 μm on a glass substrate. The coating film is cured by irradiating UV to an integrated light amount of 1500 mJ/cm ² using a UV irradiation device using an LED lamp with a main wavelength of 395 nm under a nitrogen atmosphere, and a layer (light conversion layer) made of a cured product of inkjet ink is formed on a glass substrate. formed. In this way, each evaluation sample, which was a substrate having a light conversion layer, was produced.

[External Quantum Efficiency (EQE) Evaluation]

As a surface emission light source, a blue LED manufactured by CCS CORPORATION (peak emission wavelength: 450 nm) was used. As for the measuring device, an integrating sphere was connected to a radiation spectrophotometer (product name "MCPD-9800") manufactured by OTSUKA ELECTRONICS CO., LTD, and the integrating sphere was installed above the blue LED. The prepared evaluation sample was inserted between the blue LED and the integrating sphere, and the observed spectrum and illuminance at each wavelength were measured by turning on the blue LED.

From the spectrum and illuminance measured with the above measuring device, the external quantum efficiency was determined as follows. External quantum efficiency is a value that indicates what proportion of the light (photons) incident on the light conversion layer is radiated to the observer as fluorescence. Therefore, if this value is large, it indicates that the light conversion layer has excellent luminescence characteristics, and is an important evaluation index.

EQE(%)=P1(Green)/E(Blue)×100

Here, E (Blue) and P1 (Green) respectively represent the following.

E (Blue): Represents the total value of “illuminance × wavelength ÷ hc” in the wavelength range of 380 to 490 nm.

P1 (Green): Indicates the total value of “illuminance × wavelength ÷hc” in the wavelength range of 500 to 650 nm.

These are values equivalent to the observed number of photons. Additionally, h represents Frank's constant and c represents the speed of light.

[Production of light conversion layer by inkjet method]

After sputtering metal chrome on a glass substrate made of alkali-free glass (“OA-10G” manufactured by NIPPON ELECTRIC GLASS), forming a pattern using the photolithography method, photoresist SU-8 (NIPPON KAYAKU CO., LTD. . manufactured) was applied, exposed, developed, and post-baked to form an SU-8 pattern on the chrome pattern. The design of the partition pattern produced in this way was a pattern with an opening corresponding to a sub-pixel of 100 μm x 300 μm, the line width was 20 μm, and the thickness was 10 μm.

An inkjet printer (manufactured by FUJI FILM Dimatix, brand name "DMP-2850") was used, the head temperature was set to 40°C, and the inkjet ink was discharged through the openings of the partition pattern. For compositions other than Reference Example 2, after one discharge, they were cured under a nitrogen atmosphere with a UV irradiation device that is an LED lamp with a main wavelength of 395 nm at an accumulated light amount of 1500 mJ/cm ² to produce a light conversion layer with a thickness of 10 μm.

After the composition of Reference Example 2 was discharged to the partition opening, the solvent was removed by reducing the pressure, and the inkjet ink was ejected from above into the partition pattern again by inkjet. By repeating this 5 times, a light conversion layer with a thickness of 10 μm was produced.

The results of each of the above evaluations and the number of ink jet ejections during production of the light conversion layer are shown in Table 2. In addition, in Table 2, the content The total content of organic ligands, photopolymerizable compounds, and light-scattering particles represents the total content of luminescent nanocrystal particles and organic ligands relative to 100 parts by mass.

[Table 2]

10… Pixel unit, 10a... First pixel unit, 10b... Second pixel unit, 10c... Third pixel unit, 11a... First luminescent nanocrystal particle, 11b... Second luminescent nanocrystalline particle, 12a... First light scattering particle, 12b... Second light scattering particle, 12c... Third light scattering particle, 20... Cha Gwang-bu, 30… Light conversion layer, 40... List, 100… Color filter.

Claims (7)

An inkjet ink for a color filter containing luminescent nanocrystal particles, a photopolymerizable compound and/or thermosetting resin, and light scattering particles,
The luminescent nanocrystal particles have an organic ligand on their surface,
The total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles is 41% by mass or more, based on the total mass of the inkjet ink,
The total content of the luminescent nanocrystal particles and the organic ligand is 21 parts by mass with respect to 100 parts by mass of the total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles. 60 parts by mass or less,
The content of the organic ligand is 20 parts by mass or more and 50 parts by mass or less with respect to a total content of 100 parts by mass of the luminescent nanocrystal particles and the organic ligand,
An inkjet ink for a color filter, wherein the organic ligand has a weight average molecular weight of 1000 or less. In claim 1,
Inkjet ink for a color filter, wherein the total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles is 70% by mass or more, based on the total mass of the inkjet ink. . In claim 1 or claim 2,
An inkjet ink for a color filter, wherein the organic ligand contains a polyoxyalkylene group. Equipped with a plurality of pixel units and a light-shielding unit provided between the plurality of pixel units,
A light conversion layer wherein the plurality of pixel portions have a light-emitting pixel portion containing a cured product of the inkjet ink for a color filter according to claim 1 or 2. In claim 4.
As the light-emitting pixel portion,
A first luminescent pixel portion containing luminescent nanocrystal particles that absorb light with a wavelength in the range of 420 to 480 nm and emit light with an emission peak wavelength in the range of 605 to 665 nm,
A light conversion layer comprising a second light-emitting pixel portion containing luminescent nanocrystal particles that absorb light with a wavelength in the range of 420 to 480 nm and emit light with an emission peak wavelength in the range of 500 to 560 nm. In claim 4,
A light conversion layer further comprising a non-emissive pixel portion containing light scattering particles. A color filter comprising the light conversion layer according to claim 4.

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