JP2021096323A - Color filter ink composition, light conversion layer, and color filter - Google Patents

Abstract

To provide an ink composition which contains luminescent nanocrystal particles and is capable of reducing blue leakage light.SOLUTION: An ink composition provided herein comprises luminescent nanocrystal particles, a photopolymerizable compound and/or thermosetting resin, and light scattering particles, where at least some of the luminescent nanocrystal particles absorbs light in a 420-480 nm-wavelength range, has an emission peak in a 500-560 nm-wavelength range, and contains Ag, In, G, and S as constituent elements.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composition for a color filter, an optical conversion layer, and a color filter.

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

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, for example, luminescent nanocrystal particles such as quantum dots, quantum rods, and other inorganic phosphor particles A method of forming a pixel portion such as a red pixel and a green pixel using the above is being actively studied. The color filter (QD-CF) using the luminescent nanocrystal particles has the effect of widening the color reproduction area as a display in addition to the above-mentioned low power consumption.

By the way, the method for manufacturing a color filter by the above photolithography method has a drawback that a resist material other than a pixel portion including relatively expensive luminescent nanocrystal particles is wasted due to the characteristics of the manufacturing method. Under such circumstances, in order to eliminate the waste of the resist material as described above, it has begun to be studied to form the pixel portion of the optical conversion substrate by the inkjet method (Patent Document 1).

International Publication No. 2008/001693

When applying QD-CF to a display, it has been studied to use blue light such as a blue LED or a blue OLED as a backlight source, and to use luminescent nanocrystal particles only for green pixels and red pixels. In this case, it is known that the color reproducibility of the display is improved because the emission half width of green and red is narrower than that when a normal organic pigment is used. On the other hand, in order to improve the color reproducibility of the display, it is necessary to increase the color purity of each pixel. Therefore, it is preferable that the blue light derived from the backlight source does not leak from the green pixel and the red pixel as much as possible. ..
As for luminescent nanocrystal particles, green luminescent particles having an emission peak wavelength in the range of 500 to 560 nm generally have a smaller blue light absorption rate than red luminescence, and leak blue light from green pixels. It is necessary to make it smaller, and for that purpose, there is a method of increasing the concentration of luminescent nanocrystal particles and the concentration of the light diffuser in the color conversion layer in the pixel portion of the light conversion substrate.
However, in particular, when the light conversion substrate pixel portion is formed by the inkjet method, it is necessary to keep the viscosity of the ink composition containing the luminescent nanocrystal particles within a certain range, and the luminescent nanocrystal particles and light There is a problem that when the concentration of the scattering particles is increased, the viscosity of the ink composition is also increased.

Therefore, an object of the present invention is to provide an ink composition having a viscosity suitable for forming pixel portions as an ink composition and having less leakage of blue light from green pixel portions.

One aspect of the present invention is an ink composition containing luminescent nanocrystal particles, a photopolymerizable compound and / or a thermosetting resin, and light scattering particles.
At least a part of the luminescent nanocrystal particles absorbs light having a wavelength in the range of 420 to 480 nm, has an emission peak in the range of 500 to 560 nm, and emits light having Ag, In, Ga and S as constituent elements. The present invention relates to an ink composition which is a sex nanocrystal particle.

Since the ink composition of the present invention adopts the above structure, the blue leakage light from the green pixel portion can be effectively reduced without increasing the concentration of luminescent nanocrystal particles so much, and the viscosity of the inkjet ink can be reduced. It can be contained within a range suitable for forming the pixel portion.

In the above ink composition, the viscosity at 25 ° C. may be 30 mPa · s or less.

In the above ink composition, when a 15 um light conversion layer is produced, the leakage rate of blue light may be 10% or less.

One 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 are luminescent pixel portions containing a cured product of the ink composition described above. With respect to an optical conversion layer having.

One aspect of the present invention relates to a color filter including the above-mentioned optical conversion layer.

According to the present invention, an ink composition capable of reducing leakage of blue light in a green pixel portion while having a viscosity suitable for forming a pixel portion as an inkjet ink, and an optical conversion layer and a color filter using the inkjet ink are provided. Can be provided.

FIG. 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.

<Ink composition>
The ink composition of one embodiment contains luminescent nanocrystal particles, a photopolymerizable compound and / or a thermosetting resin, and light scattering particles. This ink composition is an ink composition for a color filter used for forming pixel portions of a color filter by an inkjet method.

Since the ink composition of the present embodiment is used for forming a color filter pixel portion by an inkjet method, it is necessary without wasting materials such as luminescent nanocrystal particles and a solvent, which are relatively expensive. A color filter pixel portion (optical conversion layer) can be formed only by using a required amount for each portion.

[Luminous nanocrystal particles]
The luminescent nanocrystal particles are nano-sized crystals that absorb excitation light and emit fluorescence or phosphorescence, and for example, the maximum particle size measured by a transmission electron microscope or a scanning electron microscope is 100 nm or less. It is a crystal.

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

In the present embodiment, at least a part of the luminescent nanocrystal particles contained in the ink composition forming the green pixel contains Ag, In, Ga and S as constituent elements and has a wavelength in the range of 420 to 480 nm. It is preferably green-emitting luminescent nanocrystal particles that absorb light and have emission peaks in the range of 500 to 560 nm.

The light absorbed by the luminescent nanocrystal particles is, for example, light having a wavelength in the range of 400 nm or more and less than 500 nm (particularly, light having a wavelength in the range of 420 to 480 nm) (blue light) or light in the range of 200 nm to 400 nm. It may be light of the wavelength of (ultraviolet light). The emission peak wavelength of the luminescent nanocrystal particles can be confirmed, for example, in the fluorescence spectrum or the phosphorescence spectrum measured using a spectrofluorometer.

The red-emitting 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 of 632 nm or less or 630 nm or less, and it is preferable to have an emission peak wavelength of 628 nm or more, 625 nm or more, 623 nm or more, 620 nm or more, 615 nm or more, 610 nm or more, 607 nm or more or 605 nm or more. These upper limit values and lower limit values can be arbitrarily combined. In the same description below, the upper limit value and the lower limit value described individually can be arbitrarily combined.

Green luminescent nanocrystal particles have emission peak wavelengths of 560 nm or less, 557 nm or less, 555 nm or less, 550 nm or less, 547 nm or less, 545 nm or less, 543 nm or less, 540 nm or less, 537 nm or less, 535 nm or less, 532 nm or less, or 530 nm or less. It 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.

Blue luminescent nanocrystal particles have emission peak wavelengths of 480 nm or less, 477 nm or less, 475 nm or less, 470 nm or less, 467 nm or less, 465 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 455 nm or less, 452 nm or less, or 450 nm or less. It is preferable to have an emission peak 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.

The wavelength of light emitted by luminescent nanocrystal particles (emission color) depends on the size of the luminescent nanocrystal particles (for example, particle size) according to the solution of the Schrodinger wave equation of the well-type potential model, but the luminescent nanocrystal particles It also depends on the energy gap of the crystal particles. Therefore, the emission color can be selected by changing the constituent material and size of the luminescent nanocrystal particles to be used.

The luminescent nanocrystal particles may be luminescent nanocrystal particles (luminescent semiconductor nanocrystal particles) containing a semiconductor material. Examples of the luminescent semiconductor nanocrystal particles include quantum dots and quantum rods. Among these, quantum dots are preferable from the viewpoints that the emission spectrum can be easily controlled, reliability can be ensured, production cost can be reduced, and mass productivity can be improved.

The luminescent semiconductor nanocrystal particles may consist only of a core containing the first semiconductor material, and include a core containing the first semiconductor material and a second semiconductor material different from the first semiconductor material, as described above. It may have a shell that covers at least a portion of the core. In other words, the structure of the luminescent semiconductor nanocrystal particles may be a structure consisting of only a core (core structure) or a structure consisting of a core and a shell (core / shell structure). Further, the luminescent semiconductor nanocrystal particles contain a third semiconductor material different from the first and second semiconductor materials in addition to the shell containing the second semiconductor material (first shell), and the above-mentioned core. It may further have a shell (second shell) that covers at least a part. In other words, the structure of the luminescent semiconductor nanocrystal particles may be a structure (core / shell / shell structure) including a core, a first shell, and a second shell. Each of the core and the shell may be a mixed crystal containing two or more kinds of semiconductor materials (for example, CdSe + CdS, CIS + ZnS, etc.).

In the present embodiment, it is preferable to contain Ag, In, Ga and S as constituent elements of the semiconductor material. The composition ratio of Ag, In, Ga and S may be in any range. Here, Ag is a silver element, In is an indium element, Ga is a gallium element, and S is a sulfur element.
Further, in the luminescent nanocrystal particles containing Ag, In, Ga and S, only the core may be made of the present semiconductor material, or the core / shell may be made of the present semiconductor material. Similarly, in the case of a multi-layer structure such as a core / shell / shell, a part thereof may be made of the present semiconductor material, or all of them may be made of the present semiconductor material. When a plurality of layers are composed of the present semiconductor material, the composition ratios of Ag, In, Ga and S in each layer may be the same or different. However, from the viewpoint of emission intensity and emission peak, it is preferable that the semiconductor material of the core is composed of the present semiconductor material. When a part or all of the shell is composed of a semiconductor material other than the present semiconductor material, the semiconductor materials include II-VI group semiconductors, III-V group semiconductors, I-III-VI group semiconductors, IV group semiconductors, and the like. It preferably contains at least one semiconductor material selected from the group consisting of group I-II-IV-VI semiconductors. The luminescent nanocrystal particles are selected as the semiconductor material from the group consisting of II-VI group semiconductors, III-V group semiconductors, I-III-VI group semiconductors, IV group semiconductors and I-II-IV-VI group semiconductors. It is preferable to contain at least one semiconductor material.

Specific semiconductor materials include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSte, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, ZnSe, HgSe, and HgSe. CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSeTe, CdHgSeTe, AlHgSe, HgZnSe InP, InAs, InSb, COLP, PLACS, PLACSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeNe SnPbSTe; Si, Ge, SiC, SiGe, AgInSe ₂ , CuGaSe ₂ , CuInS ₂ , CuGaS ₂ , CuInSe ₂ , AgInS ₂ , AgGaSe ₂ , AgGaS ₂ , C, Si and Ge. From the viewpoint that the emission spectrum of luminescent semiconductor nanocrystal particles can be easily controlled, reliability can be ensured, production cost can be reduced, and mass productivity can be improved, CdS, CdSe, CdTe, ZnS, _{ZnSe, ZnTe, ZnO, HgS,} HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS 2, AgInSe 2, AgInTe 2, AgGaS 2, AgGaSe 2, AgGaTe 2, CuInS 2, CuInSe 2, CuInTe 2 , CuGaS ₂ , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge and Cu ₂ ZnSnS ₄ preferably comprises at least one selected from the group.

Further, when blending the ink composition, luminescent nanocrystals containing no semiconductor material composed of Ag, In, Ga and S may be used in combination as the luminescent nanocrystal particles. In that case, any semiconductor material described below is used as the semiconductor material.

Examples of the red-emitting semiconductor nanocrystal particles include CdSe nanocrystal particles and nanocrystal particles having a core / shell structure, wherein the shell portion is CdS and the inner core portion is CdSe. Nanocrystal particles having a particle, core / shell structure, the shell portion of which is CdS and the inner core portion of ZnSe, nanocrystal particles of mixed crystals of CdSe and ZnS, and nano of InP. Crystal particles, nanocrystal particles having a core / shell structure, nanocrystal particles having a shell portion of ZnS and an inner core portion of InP, and nanocrystal particles having a core / shell structure. The shell part is a mixed crystal of ZnS and ZnSe and the inner core part is InP nanocrystal particles, a mixed crystal nanocrystal particle of CdSe and CdS, a mixed crystal nanocrystal particle of ZnSe and CdS, a core. Nanocrystal particles with a / shell / shell structure, the first shell portion is ZnSe, the second shell portion is ZnS, and the inner core portion is InP. Nanocrystal particles, core / shell / Nanocrystal particles having a shell structure, the first shell portion is a mixed crystal of ZnS and ZnSe, the second shell portion is ZnS, and the inner core portion is InP. And so on.

Examples of the green luminescent semiconductor nanocrystal particles include CdSe nanocrystal particles, mixed crystal nanocrystal particles of CdSe and ZnS, and nanocrystal particles having a core / shell structure, and the shell portion is ZnS. Nanocrystal particles whose inner core is InP, nanocrystals having a core / shell structure, whose shell is a mixed crystal of ZnS and ZnSe, and whose inner core is InP. Crystal particles, nanocrystal particles having a core / shell / shell structure, in which the first shell portion is ZnSe, the second shell portion is ZnS, and the inner core portion is InP. , Nanocrystal particles with a core / shell / shell structure, the first shell part is a mixed crystal of ZnS and ZnSe, the second shell part is ZnS, and the inner core part is InP. Examples include certain nanocrystal particles.

The blue-emitting semiconductor nanocrystal particles include, for example, ZnSe nanocrystal particles, ZnS nanocrystal particles, and nanocrystal particles having a core / shell structure, and the shell portion is ZnSe and the inner core portion. Is ZnS nanocrystal particles, CdS nanocrystal particles, nanocrystal particles having a core / shell structure, and the shell portion is ZnS and the inner core portion is InP nanocrystal particles, core / shell. Nanocrystal particles having a structure, in which the shell portion is a mixed crystal of ZnS and ZnSe and the inner core portion is InP, and the nanocrystal particles have a core / shell / shell structure. The first shell portion is ZnSe, the second shell portion is ZnS, the inner core portion is InP, and the nanocrystal particles have a core / shell / shell structure. Examples thereof include nanocrystal particles in which the first shell portion is a mixed crystal of ZnS and ZnSe, the second shell portion is ZnS, and the inner core portion is InP.

The semiconductor nanocrystal particles have the same chemical composition, and by changing the average particle size of the particles themselves, the color to be emitted from the particles can be changed to red or green. Further, it is preferable to use semiconductor nanocrystal particles that have as little adverse effect on the human body as possible. When semiconductor nanocrystal particles containing cadmium, selenium, etc. are used as luminescent nanocrystal particles, semiconductor nanocrystal particles containing the above elements (cadmium, selenium, etc.) as little as possible are selected and used alone, or the above elements. It is preferable to use it in combination with other luminescent nanocrystal particles so that the amount of selenium is as small as possible.

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, spherical, ellipsoidal, pyramidal, disk-shaped, branched, net-shaped, rod-shaped, or the like. However, as the luminescent nanocrystal particles, using particles having less directional particle shape (for example, spherical or tetrahedral particles) can further improve the uniformity and fluidity of the ink composition. Is preferable.

The average particle size (volume average diameter) of the luminescent nanocrystal particles may be 1 nm or more, and may be 1.5 nm, from the viewpoint of easily obtaining light emission of a desired wavelength and from the viewpoint of excellent dispersibility and storage stability. It may be more than 2 nm and may be 2 nm or more. From the viewpoint that a desired emission wavelength can be easily obtained, 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 with a transmission electron microscope or a scanning electron microscope and calculating the volume average diameter.

Luminescent nanocrystal particles have an organic ligand on their surface from the viewpoint of dispersion stability. The organic ligand may be coordinate-bonded to, for example, the surface of the luminescent nanocrystal particles. In other words, the surface of the luminescent nanocrystal particles may be passivated by an organic ligand. When the ink composition further contains a polymer dispersant described later, the luminescent nanocrystal particles may have a polymer dispersant on the surface thereof. In the present embodiment, for example, the organic ligand is removed from the luminescent nanocrystal particles having the above-mentioned organic ligand, and the organic ligand is exchanged with the polymer dispersant to cause the polymer dispersant on the surface of the luminescent nanocrystal particles. May be combined. However, from the viewpoint of dispersion stability when the ink composition is prepared, it is preferable that the polymer dispersant is blended with the luminescent nanocrystal particles in which the organic ligand is still coordinated.

The organic ligand may contain a functional group (hereinafter, also referred to as "affinity group") for ensuring affinity with a photopolymerizable compound, a thermosetting resin, an organic solvent and the like. The affinity group may be a substituted or unsubstituted aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be a linear type or may have a branched structure. Further, the aliphatic hydrocarbon group may have an unsaturated bond or may not have an unsaturated bond. The substituted aliphatic hydrocarbon may be a group in which some carbon atoms of the aliphatic hydrocarbon group are substituted with oxygen atoms. The substituted aliphatic hydrocarbon group may contain, for example, a (poly) oxyalkylene group.

The organic ligand preferably contains a polyoxyalkylene group. The polyoxyalkylene group is a divalent group in which two or more alkylene groups are linked by 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 as or different from each other. The alkylene group may be linear and may have a branched structure. Further, the alkylene group may have an unsaturated bond or may not have an unsaturated bond.

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 preferably has an oxyalkylene structure having an ethylene group (oxyethylene structure), an oxyalkylene structure having a propylene group (oxypropylene structure), and an oxyalkylene structure having a butylene group (oxybutylene structure). ) Have at least one selected from the group consisting of.

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

In formula (1), R ¹ and R ² independently represent a hydrogen atom, a methyl group or an ethyl group, and * indicates 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 the formula (1), the plurality of R ^1s may be the same or different, and the plurality of R ^2s 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 means the number of repetitions of the oxyalkylene structure (the number of alkylene groups linked by an ether bond).

When the polyoxyalkylene group contains a repetition of an oxyethylene structure, the number of repetitions 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 a repetition of an oxypropylene structure, the number of repetitions 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 means the longest molecular chain constituting the organic ligand.

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

The number of functional groups that can be bound to the luminescent nanocrystal particles in the organic ligand may be 1-3, 1-2, or 1. At least one of the functional groups capable of binding to the luminescent nanocrystal particles in the organic ligand that the luminescent nanocrystal particles have on the surface thereof may be a functional group bonded to the luminescent nanocrystal particles. When the organic ligand contains a plurality of functional groups capable of binding to the luminescent nanocrystal particles, some of the plurality of functional groups may not be bound to the luminescent nanocrystal particles.

A functional group capable of binding to the luminescent nanocrystal particles may be present at at least one end of the main chain of the organic ligand. That is, the organic ligand may contain a functional group capable of binding to luminescent nanocrystal particles at at least one end 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 capable of forming a hydrogen bond with a carbonyl group or the like. The hydrogen-bonding group may be a group capable of binding to luminescent nanocrystal particles. The organic ligand present on the surface of the luminescent nanocrystal particles preferably has a hydrogen-bonding group that is not bound to the luminescent nanocrystal particles. Examples of the hydrogen-bonding group include a monovalent group such as a hydroxyl group, an amino group, a carboxyl group and a thiol group, and a divalent group such as an amide group (-NHCO-).

The organic ligand has one or more first functional groups capable of binding to luminescent nanocrystal particles at one end of the main chain, and a second functional group different from the first functional group at the other end of the main chain. It may have a group. The first functional group may be the same as the group described above as a functional group capable of binding to the luminescent nanocrystal particles. The number of the first functional groups may be 1 or more, 2 or more, and 2 may be. The second functional group may be the same as the above-mentioned group as a functional group capable of binding to the luminescent nanocrystal particles, and may be another group different from the functional group. The other group may be, for example, an alkyl group, a cycloalkyl group, or an aryl group. The number of the second functional group 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 substituted or unsubstituted hydrocarbon group may have, for example, 1 to 10 carbon atoms. In the substituted hydrocarbon group, a part of the carbon atom may be substituted with a hetero atom such as a sulfur atom or a nitrogen atom, a carbonyl group or the like.

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

In equation (1-1), p represents an integer from 0 to 50, and q represents an integer from 0 to 50. At least one of p and q is preferably 1 or more, and both p and q are more preferably 1 or more.

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

[In equation (1-2), r represents an integer of 1 to 50. ]

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

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

In formula (1-3), A ¹ and A ² each independently represent a monovalent group which may contain a functional group capable of binding to the above-mentioned luminescent nanocrystal particles, and R is a hydrogen atom. It represents a methyl group or an ethyl group, where 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 the functional groups capable of binding to the luminescent nanocrystal particles described above, and the total number of functional groups capable of binding to the luminescent nanocrystal particles in ^{A 1} and A ² Is two or more. When A ¹ or A ² is a group containing no functional group capable of binding to luminescent nanocrystal particles, A ¹ or A ² may be, for example, a hydrogen atom.

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 one or two or more, and may be four or less, respectively.} It may be one. The functional group capable of binding 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 luminescent nanocrystal particles in the monovalent group represented by ^{A 2 are present.} It is preferable that the number of functional groups that can be bonded to is one. In this case, the functional groups capable of binding to the two luminescent nanocrystal particles in the monovalent group represented by ^{A 1} are both carboxyl groups, and the luminescent nanocrystal particles in the monovalent group represented by ^{A 2} It is more preferable that the functional group capable of binding to is a hydroxyl group.

In another embodiment, the ^{monovalent group represented by A 1} has two functional groups capable of binding to the luminescent nanocrystal particles, and A ² is represented by a hydrogen atom (ie, A ² ). The number of functional groups that can be bonded to the luminescent nanocrystal particles in the monovalent group is preferably 0). In this case, it is more preferable that the functional group capable of binding to the two luminescent nanocrystal particles in the monovalent group represented by ^{A 1 is a carboxyl group.}

The carbon number of the alkylene group represented by L may be, for example, 1 to 10. In the alkylene group represented by L, a part of the carbon atom (methylene group) may be substituted with a hetero atom. When L is a substituted alkylene group, in the alkylene group, a part of the carbon atom (methylene group) is preferably at least one hetero selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom. It is substituted with an atom, more preferably with a sulfur atom. s may be, for example, 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 is preferably a compound represented by the following formula (1-4).

In equation (1-4), p and q are independently integers of 0 or more, r is an integer of 1 or more, and A ¹ , A ^{2 and s are A 1} , 1 in equation (1-3). It is synonymous with A ² and s, respectively. However, at least one of p and q is an integer of 1 or more.

p may be an integer of 3 or less, 2 or less, or 1 or less, and may be 0. q may be an integer of 1 or more, 2 or more, or 3 or more, an integer of 5 or less, 4 or less, or 3 or less, and may be 3. r may be an integer of 4 or less, 3 or less, or 2 or less, and may be 1.

The organic ligand is more preferably a compound represented by the following formula (1-5) or (1-6).

In formulas (1-5) and (1-6), s is synonymous with s in formula (1-3).

Examples of the organic ligand containing a functional group capable of binding to luminescent nanocrystal particles include TOP (trioctylphosphine), TOPO (trioctylphosphine oxide), lauric acid, oleic acid, oleylamine, octylamine, and trioctylamine. Hexadecylamine, octanethiol, dodecanethiol, hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), and octylphosphinic acid (OPA).

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, and may be 250 or less, from the viewpoint that the viscosity of the ink composition becomes more suitable for the formation of the pixel portion. It may be 300 or more, 400 or more, 450 or more, 500 or more, or 550 or more. In the present specification, the weight average molecular weight is a polystyrene-equivalent weight average molecular weight measured by GPC (Gel Permeation Chromatography).

As the luminescent nanocrystal particles, those dispersed in a colloidal form in an organic solvent, a photopolymerizable compound, or the like can be used. The surface of the luminescent nanocrystal particles dispersed in an organic solvent is preferably passivated by the above-mentioned organic ligand. Examples of the organic solvent include cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether, propylene glycol monomethyl ether acetate, butyl carbitol acetate, 1,4-butanediol diacetate, or a mixture thereof. Can be mentioned.

Commercially available products can be used as the luminescent nanocrystal particles. Examples of commercially available luminescent nanocrystal particles include indium phosphide / zinc sulfide, D-dot, CuInS / ZnS from NN-Labs, and InP / ZnS from Aldrich.

The content of the luminescent nanocrystal particles having Ag, In, Ga and S is determined from the viewpoint of leakage of blue light, such as the luminescent nanocrystal particles in the ink composition, an organic ligand, a photopolymerizable compound, and a thermosetting resin. , And the total content of the light-scattering particles (total content of the non-volatile content) is preferably more than 5 parts by mass, more preferably 7 parts by mass or more, still more preferably 10 parts by mass with respect to 100 parts by mass. That is all. When the content of the luminescent nanocrystal particles is more than 10 parts by mass, the absorption rate of blue light is excellent, so such an ink composition is suitably used for color filter applications. The content of the luminescent nanocrystal particles having Ag, In, Ga and S is such that the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound and the heat in the ink composition are excellent from the viewpoint of excellent ejection stability and curability. The total content of the curable resin and the light-scattering particles (total content of non-volatile particles) is 100 parts by mass, preferably 60 parts by mass or less, 50 parts by mass or less, and 40 parts by mass. It may be less than or equal to 35 parts by mass or less. The content of the luminescent nanocrystal particles is the total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the photoscattering particles in the ink composition (total content of non-volatile components). ) More than 10 parts by mass 60 parts or less, 13 to 60 parts by mass, 15 to 60 parts by mass, more than 10 parts by 50 parts or less, more than 10 parts by 40 parts or less, or 10 parts by mass. It may be more than 35 parts by mass and less than 35 parts by mass. Further, the luminescent nanocrystal particles may be used by mixing luminescent nanocrystal particles having Ag, In, Ga and S with other luminescent nanocrystal particles.

The total content (total content of non-volatile content) of luminescent nanocrystal particles, organic ligand, photopolymerizable compound, thermosetting resin, and light-scattering particles in the ink composition is the total mass of the ink composition. As a standard, it is 41% by mass or more, 45% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, It may be 85% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass. The total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light scattering particles in the ink composition (total content of non-volatile components) determines the total mass of the ink composition. When it is 70% by mass or more as a reference, it is preferably used as a solvent-free ink composition.

When the ink composition contains a photopolymerizable compound and does not contain a thermosetting resin, the total content of the non-volatile components is the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, and light scattering. The total content of sex particles. When the ink composition contains a thermosetting resin and does not contain a photopolymerizable compound, the total content of the non-volatile components is the luminescent nanocrystal particles, the organic ligand, the thermosetting resin, and the like. The total content of light-scattering particles.

The ink composition may contain, as the luminescent nanocrystal particles, two or more of red luminescent nanocrystal particles, green luminescent nanocrystal particles, and blue luminescent nanocrystal particles, but these are preferable. Contains only one of the particles. When the ink composition contains red luminescent nanocrystal particles, the content of the green luminescent nanocrystal particles and the content of the blue luminescent nanocrystal particles are preferably 10 based on the total mass of the luminescent nanocrystal particles. It is not more than mass%, and more preferably 0 mass%. When the ink composition contains green luminescent nanocrystal particles, the content of the red luminescent nanocrystal particles and the content of the blue luminescent nanocrystal particles are preferably 10 based on the total mass of the luminescent nanocrystal particles. It is not more than mass%, and more preferably 0 mass%.

The total content of the luminescent nanocrystal particles having Ag, In, Ga and S and the organic ligand is the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering in the ink composition. 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 21 parts by mass or more, 25 parts by mass or more, 27 parts by mass or more, 30 parts by mass or more, based on 100 parts by mass of the total content of the sex particles. It may be 35 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more or 50 parts by mass or more, 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less or 55 parts by mass, 50 parts by mass, 45 parts by mass. It may be less than or equal to a part.

The content of the organic ligand is 10 parts by mass or more and 15 parts by mass from the viewpoint of suppressing thickening of the ink composition due to air exposure with respect to 100 parts by mass of the total content of the luminescent nanocrystal particles and the organic ligand. It may be 50 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, or 32 parts by mass or more, and 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, or 38 parts by mass or less. There may be. When the content of the organic ligand is 50 parts by mass or less with respect to the total content of 100 parts by mass of the luminescent nanocrystal particles and the organic ligand, the content of the luminescent nanocrystal particles in the ink composition is relatively high. It is preferable because it can be used. The content of the organic ligand with respect to 100 parts by mass of the total content of the luminescent nanocrystal particles and the organic ligand in the present specification can be determined by TG-DTA measurement of a mixture composed of the luminescent nanocrystal particles and the organic ligand. It is defined as the mechanism (ratio of organic compounds). A mixture consisting of luminescent nanocrystal particles and an organic ligand can be obtained by adding a poor solvent for the mixture to the ink composition, allowing the mixture to settle, and then drying.

[Photopolymerizable compound]
The photopolymerizable compound of the present embodiment is a compound that polymerizes by irradiation with light, and is, for example, a photoradical polymerizable compound or a photocationic polymerizable compound. The photopolymerizable compound may be a photopolymerizable monomer or oligomer. These are used with photopolymerization initiators. Photoradical polymerizable compounds are used with photoradical polymerization initiators and photocationic polymerizable compounds are used with photocationic polymerization initiators. In other words, the ink composition may contain a photopolymerizable component containing a photopolymerizable compound and a photopolymerization initiator, and may contain a photoradical polymerizable component containing a photoradical polymerizable compound and a photoradical polymerization initiator. It may contain a photocationic polymerizable component containing a photocationic polymerizable compound and a photocationic polymerization initiator. A photoradical polymerizable compound and a photocationic polymerizable compound may be used in combination, or a compound having photoradical polymerizable property and photocationic polymerizable property may be used, and a photoradical polymerization initiator and a photocationic polymerization initiator may be used. May be used together. One type of photopolymerizable compound may be used alone, or two or more types may be used in combination.

Examples of the photoradical polymerizable compound include a monomer having an ethylenically unsaturated group (hereinafter, also referred to as “ethylenically unsaturated monomer”), a monomer having an isocyanate group, and the like. Here, the ethylenically unsaturated monomer means a monomer having an ethylenically unsaturated bond (carbon-carbon double bond). Examples of the ethylenically unsaturated monomer include a monomer having an ethylenically unsaturated group such as a vinyl group, a vinylene group, and a vinylidene group. Monomers having these groups may be 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. One type of ethylenically unsaturated monomer may be used alone, or a plurality of types may be used in combination. The photopolymerizable compound has one or two ethylenically unsaturated groups from the viewpoint of facilitating both excellent ejection stability and excellent curability and further improving the external quantum efficiency. It may contain a monomer and a monomer having two or three ethylenically unsaturated groups. That is, the ethylenically unsaturated monomer is selected from at least a group consisting of a monofunctional monomer and a bifunctional monomer, a monofunctional monomer and a trifunctional monomer, a bifunctional monomer and a bifunctional monomer, and a bifunctional monomer and a trifunctional monomer. It may contain one combination. In the present embodiment, the photopolymerizable compound preferably contains two or more types of monomers having two ethylenically unsaturated bonds.

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

Examples of the monofunctional monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and 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 (Meta) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl ( Meta) acrylate, benzyl (meth) acrylate, phenylbenzyl (meth) acrylate, monosuccinate (2-acryloyloxyethyl), monosuccinate (2-methacryloyloxyethyl), N- [2- (acryloyloxy) ethyl] Examples thereof include phthalimide, N- [2- (acryloyloxy) ethyl] tetrahydrophthalimide, 4-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, and the like. Among these, ethoxyethoxyethyl (meth) acrylate is preferably used.

Specific examples of the monomer having two ethylenically unsaturated groups (bifunctional monomer) include 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,5-pentane. Didiol 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, tricyclodecanedimethanol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate ) Acrylate, Dipropylene glycol di (meth) acrylate, Tripropylene glycol di (meth) acrylate, Polypropylene glycol di (meth) acrylate, Neopentylglycol hydroxypivalate diacrylate, Tris (2-hydroxyethyl) ) Di (meth) acrylate in which two hydroxyl groups of isocyanurate are substituted with (meth) acryloyloxy group, and two diols obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol. The two hydroxyl groups of the diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of di (meth) acrylate and bisphenol A in which the hydroxyl groups of the above are substituted with (meth) acryloyloxy groups are (meth) acryloyloxy groups. Di (meth) acrylate substituted with (meth) Acryloyloxy group The two hydroxyl groups of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane are substituted with (meth) acryloyloxy group. Examples thereof include meta) acrylate and di (meth) acrylate in which two hydroxyl groups of a diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A are substituted with (meth) acryloyloxy groups. 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 having three ethylenically unsaturated groups (trifunctional monomer) include glycerin tri (meth) acrylate and trimethylolethanetri (meth) acrylate. Among these, glycerin tri (meth) acrylate is preferably used.

Examples of the photocationically polymerizable compound include an epoxy compound, an oxetane compound, and a vinyl ether compound.

Examples of the epoxy compound include aliphatic epoxy compounds such as bisphenol A type epoxy compound, bisphenol F type epoxy compound, phenol novolac type epoxy compound, trimethylolpropane polyglycidyl ether, and neopentyl glycol diglycidyl ether, 1,2-epoxy-. Examples thereof include alicyclic epoxy compounds such as 4-vinylcyclohexane and 1-methyl-4- (2-methyloxylanyl) -7-oxabicyclo [4.1.0] heptane.

It is also possible to use a commercially available product as the epoxy compound. As commercially available epoxy compounds, for example, "Celoxide 2000", "Celoxide 3000", "Celoxide 4000", etc. manufactured by Daicel Chemical Industries, Ltd. can be used.

Cationicly polymerizable oxetane compounds include 2-ethylhexyl oxetane, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, and 3-hydroxymethyl-3. -Normal butyl oxetane, 3-hydroxymethyl-3-phenyloxetane, 3-hydroxymethyl-3-benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-hydroxyethyl-3-ethyloxetane, 3-hydroxyethyl- 3-propyl oxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3-methyloxetane, 3-hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyl oxetane, 3-hydroxypropyl- Examples thereof include 3-phenyloxetane and 3-hydroxybutyl-3-methyloxetane.

It is also possible to use a commercially available product as an oxetane compound. Examples of commercially available oxetane compounds include Aron oxetane series manufactured by Toa Synthetic Co., Ltd. (“OXT-101”, “OXT-212”, “OXT-121”, “OXT-221”, etc.); Company-made "Selokiside 2021", "Selokiside 2021A", "Selokiside 2021P", "Selokiside 2080", "Selokiside 2081", "Selokiside 2083", "Selokiside 2085", "Epolide GT300", "Epolide GT301", "Epolide" GT302, "Epolide GT400", "Epolide GT401" and "Epolide GT403"; "Cyracure UVR-6105", "Cyracure UVR-6107", "Cyracure UVR-6110", "Cyracure UVR" manufactured by Dow Chemical Japan Co., Ltd. -6128, "ERL4289", "ERL4299" and the like can be used. Further, a known oxetane compound (for example, the oxetane compound described in JP-A-2009-40830) can also be used.

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

Further, as the photopolymerizable compound in the present embodiment, the photopolymerizable compounds described in paragraphs 0042 to 0049 of JP2013-182215A can also be used.

The photopolymerizable compound may be alkali-insoluble from the viewpoint that a highly reliable pixel portion (cured product of the ink composition) can be easily obtained. In the present specification, the fact that the photopolymerizable compound is alkali-insoluble means that the amount of the photopolymerizable compound dissolved in 1% by mass of potassium hydroxide aqueous solution at 25 ° C. is 30 based on the total mass of the photopolymerizable compound. It means that it is not more than% by mass. The dissolved amount of the photopolymerizable compound is preferably 10% by mass or less, and more preferably 3% by mass or less.

The content of the photopolymerizable compound is determined from the viewpoint that an appropriate viscosity can be easily obtained as an ink composition, from the viewpoint of improving the curability of the ink composition, and the solvent resistance of the pixel portion (cured product of the ink composition). From the viewpoint of improving abrasion resistance, the total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light-scattering particles in the ink composition is 100 parts by mass. It may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more. The content of the photopolymerizable compound is determined in the ink composition from the viewpoint that an appropriate viscosity can be easily obtained as the ink composition and from the viewpoint of obtaining more excellent optical characteristics (for example, the effect of suppressing a decrease in external quantum efficiency). The total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light-scattering particles may be 60 parts by mass or less, and 50 parts by mass or less with respect to 100 parts by mass. It may be 40 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less.

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

Examples of the molecular cleavage type photoradical polymerization initiator include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-benzyl-2-dimethylamino-1. -(4-morpholinophenyl) -butane-1-one, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide Etc. are preferably used. Other molecular cleavage type photoradical polymerization initiators include 1-hydroxycyclohexylphenyl ketone, benzoin ethyl ether, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4). -Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one may be used in combination.

Examples of the hydrogen abstraction type photoradical polymerization initiator include benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyl-diphenylsulfide and the like. A molecular cleavage type photoradical polymerization initiator and a hydrogen abstraction type photoradical polymerization initiator may be used in combination.

A commercially available product can also be used as the photocationic polymerization initiator. Commercially available products include sulfonium salt-based photocationic polymerization initiators such as "CPI-100P" manufactured by San-Apro, acylphosphine oxide compounds such as "Lucirin TPO" manufactured by BASF, and "Irgacure 907" manufactured by BASF. Examples thereof 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 and 0.5 part by mass or more with respect to 100 parts by mass of the photopolymerizable compound from the viewpoint of curability of the ink composition. It may be 1 part by mass or more, 3 parts by mass or more, or 5 parts by mass or more. The content of the photopolymerization initiator may be 40 parts by mass or less, and 30 parts by mass with respect to 100 parts by mass of the photopolymerizable compound, from the viewpoint of the temporal stability of the pixel portion (cured product of the ink composition). It may be 20 parts by mass or less, 10 parts by mass or less.

[Thermosetting resin]
In the present embodiment, the thermosetting resin is a resin that is crosslinked and cured by heat. The thermosetting resin is, for example, a resin that functions as a binder in a cured product. Thermosetting resins have curable groups. Examples of the curable group include an epoxy group, an oxetane group, an isocyanate group, an amino group, a carboxyl group, a methylol group, etc. For example, an epoxy group is preferable from the viewpoint of excellent adhesion to the black matrix) and the substrate. The thermosetting resin may have one kind of curable group, or may have two or more kinds of curable groups.

Among the thermosetting resins, a resin having photoradical polymerization (polymerized by irradiation with light when used together with a photoradical polymerization initiator) and a photocationic polymerizable resin (photocationic polymerization). Contains resins (polymerized by light irradiation when used with initiators). When the ink composition contains a thermosetting resin having photoradical polymerization property and a photoradical polymerization initiator, the thermosetting resin having photoradical polymerization property becomes a photoradical polymerizable compound (photopolymerizable compound). It shall be classified. When the ink composition contains a photocationically polymerizable thermosetting resin and a photocationic polymerization initiator, the photocationically polymerizable thermosetting resin becomes a photocationically polymerizable compound (photopolymerizable compound). It shall be classified.

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

As the thermosetting resin, a compound having two or more thermosetting groups in one molecule is used, and it is usually used in combination with a curing agent. When a thermosetting resin is used, a catalyst (curing accelerator) capable of accelerating the thermosetting reaction may be further added. In other words, the ink composition may contain a thermosetting component containing a thermosetting resin (as well as a curing agent and a curing accelerator used as needed). In addition to these, a polymer that does not have a polymerization reactivity by itself may be further used.

As the 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. The "epoxy resin" includes both a monomeric epoxy resin and a polymeric epoxy resin. The number of epoxy groups contained in one molecule of the polyfunctional epoxy resin is preferably 2 to 50, more preferably 2 to 20. The epoxy group may have a structure having an oxylan ring structure, and may be, for example, a glycidyl group, an oxyethylene group, an epoxycyclohexyl group, or the like. Examples of the epoxy resin include known polyvalent epoxy resins that can be cured by a carboxylic acid. Such epoxy resins are widely disclosed in, for example, "Epoxy Resin Handbook" edited by Masaki Shinbo, published by Nikkan Kogyo Shimbun (1987), and these can be used.

Examples of the thermosetting resin having an epoxy group (including a polyfunctional epoxy resin) include a polymer of a monomer having an oxylan ring structure and a copolymer of a monomer having an oxylan ring structure and another monomer. Specific polyfunctional epoxy resins include polyglycidyl methacrylate, methyl methacrylate-glycidyl methacrylate copolymer, benzyl methacrylate-glycidyl methacrylate copolymer, n-butyl methacrylate-glycidyl methacrylate copolymer, and 2-hydroxyethyl methacrylate-glycidyl. Examples thereof include a methacrylate copolymer, a (3-ethyl-3-oxetanyl) methyl methacrylate-glycidyl methacrylate copolymer, and a styrene-glycidyl methacrylate. Further, as the thermosetting resin of the present embodiment, the compounds described in paragraphs 0044 to 0066 of JP-A-2014-562248 can also be used.

Examples of the polyfunctional epoxy resin include 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, and naphthalene type epoxy. Resin, biphenyl type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional epoxy resin, tetraphenylol ethane type epoxy resin, dicyclopentadiene Phenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, glioxal type epoxy resin, alicyclic epoxy resin , Heterocyclic epoxy resin and the like can be used.

More specifically, a bisphenol A type epoxy resin such as the product name "Epicoat 828" (manufactured by Japan Epoxy Resin Co., Ltd.), a bisphenol F type epoxy resin such as the product name "YDF-175S" (manufactured by Toto Kasei Co., Ltd.), and a product name. Brominated bisphenol A type epoxy resin such as "YDB-715" (manufactured by Toto Kasei Co., Ltd.), bisphenol S type epoxy resin such as trade name "EPICLON EXA1514" (manufactured by DIC Co., Ltd.), trade name "YDC-1312" (Toto) Hydroquinone type epoxy resin such as (manufactured by Kasei Co., Ltd.), Naphthalene type epoxy resin such as product name "EPICLON EXA4032", "HP-4770", "HP-4700", "HP-5000" (manufactured by DIC Co., Ltd.), product name Biphenyl type epoxy resin such as "Epicoat YX4000H" (manufactured by Japan Epoxy Resin), bisphenol A type novolac epoxy resin such as product name "Epicoat 157S70" (manufactured by Japan Epoxy Resin), product name "Epicoat 154" (Japan Epoxy) Resin company), phenol novolac type epoxy resin such as product name "YDPN-638" (manufactured by Toto Kasei Co., Ltd.), cresol novolac type epoxy resin such as product name "YDCN-701" (manufactured by Toto Kasei company), product name " Dicyclopentadienephenol type epoxy resin such as "EPICLON HP-7200" and "HP-7200H" (manufactured by DIC Co., Ltd.), Trishydroxyphenylmethane type epoxy resin such as trade name "Epicoat 1032H60" (manufactured by Japan Epoxy Resin Co., Ltd.), Trifunctional epoxy resin such as product name "VG3101M80" (manufactured by Mitsui Kagaku Co., Ltd.), tetraphenylol ethane type epoxy resin such as product name "Epicoat 1031S" (manufactured by Japan Epoxy Resin), product name "Denacol EX-411" 4-functional epoxy resin (manufactured by Nagase Kasei Kogyo Co., Ltd.), hydrogenated bisphenol A type epoxy resin such as product name "ST-3000" (manufactured by Toto Kasei Co., Ltd.), product name "Epicoat 190P" (manufactured by Japan Epoxy Resin) ) Etc., glycidyl ester type epoxy resin such as trade name "YH-434" (manufactured by Toto Kasei Co., Ltd.), glycidyl amine type epoxy resin such as trade name "YDG-414" (manufactured by Toto Kasei Co., Ltd.), Triglycidyl isocyanate, an alicyclic polyfunctional epoxy compound such as the product name "Epolide GT-401" (manufactured by Daicel Chemical Co., Ltd.) Heterocyclic epoxy resins such as TGIC) can be exemplified. If necessary, a trade name "Neo Tote E" (manufactured by Toto Kasei Co., Ltd.) or the like can be mixed as an epoxy-reactive diluent.

As the polyfunctional epoxy resin, "Findick A-247S", "Findick A-254", "Findick A-253", "Findick A-229-30A", "Fine Dick A-229-30A" manufactured by DIC Corporation "Dic A-261", "Find Dick A249", "Find Dick A-266", "Find Dick A-241", "Find Dick M-8020", "EPICLON N-740", "EPICLON N-770", " "EPICLON N-865", "EPICLON EXA-4850-150" (trade name) and the like can be used.

The weight average molecular weight of the thermosetting resin is determined from the viewpoint that an appropriate viscosity can be easily obtained as an ink composition, from the viewpoint of improving the curability of the ink composition, and the solvent resistance of the pixel portion (cured product of the ink composition). From the viewpoint of improving the property and abrasion resistance, it may be 750 or more, 1000 or more, or 2000 or more. From the viewpoint of obtaining an appropriate viscosity as an ink composition, it may be 500,000 or less, 300,000 or less, or 200,000 or less. However, this does not apply to the molecular weight after cross-linking.

The content of the thermosetting resin is determined from the viewpoint that an appropriate viscosity can be easily obtained as the ink composition, from the viewpoint of improving the curability of the ink composition, and the solvent resistance of the pixel portion (cured product of the ink composition). From the viewpoint of improving abrasion resistance, the total content of luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light-scattering particles in the ink composition is 100 parts by mass. 5, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more. The content of the thermosetting resin is such that the luminescent nanocrystal particles in the ink composition are not excessively thickened with respect to the light conversion function, and the viscosity of the ink composition is not too high. The total content of the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles may be 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass with respect to 100 parts by mass. It may be less than a part, 30 parts by mass or less, or 20 parts by mass or less.

[Curing agent]
Examples of the curing agent used for curing the thermosetting resin include acid anhydrides, phenolic compounds, amine compounds and the like. These curing agents may be used alone or in combination of two or more. The curing agent preferably contains at least one selected from the group consisting of acid anhydrides, phenolic compounds and amine compounds. When the epoxy resin is used as the thermosetting resin, it may be self-polymerized using onium salts, organometallic complexes, tertiary amines, imidazoles and the like.

Examples of the acid anhydride (acid anhydride-based curing agent) include 4-methylcyclohexane-1,2-dicarboxylic acid anhydride (4M-HHPA), 3-methylcyclohexane-1,2-dicarboxylic acid 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 end Methylene-1,2,3,6-tetrahydrophthalic anhydride, 3,6 endomethylene-1,2,3,6-tetrahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleine anhydride Acids and the like can be mentioned.

Examples of phenolic compounds (phenolic curing agents) include bisphenol A, bisphenol F, bisphenol S, resorcin, catechol, hydroquinone, fluorene bisphenol, 4,4'-biphenol, 4,4', 4 "-trihydroxytriphenylmethane. , Naphthalenediol, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, calix arene, novolak type phenolic resin (eg, phenol novolac resin, cresol novolak resin, bisphenol A novolak resin, bisphenol S novolak resin, resorcin Polyvalent phenol novolac resin synthesized from polyvalent hydroxy compounds typified by novolak resin and formaldehyde, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, naphthol novolak resin, and alkoxy group-containing aromatic ring modification Novolac resin (polyvalent phenol compound in which a phenol nucleus and an alkoxy group-containing aromatic ring are linked with formaldehyde), aralkyl-type phenol resin (for example, phenol aralkyl resin such as Zyroc resin and naphthol aralkyl resin), aromatic hydrocarbon formaldehyde resin Modified phenol resin, dicyclopentadienephenol-added resin, trimethylolmethane resin, tetraphenylol ethane resin, biphenyl-modified phenol resin (polyvalent phenol compound in which phenol nuclei are linked by bismethylene groups), biphenyl-modified naphthol resin (bismethylene groups) Polyvalent naphthol compounds with phenol nuclei linked in), polyhydric phenol compounds with aminotriazine-modified phenolic resins (polyphenol compounds with phenol nuclei linked with melamine, benzoguanamine, etc.), etc. From the viewpoint of excellent improvement effect, the phenolic compound preferably contains a novolak type phenol resin. As the novolak type phenol resin, a phenol novolak resin, a cresol novolak resin and a bisphenol A novolak resin are preferably used.

Specific examples of the novolak type phenol resin include "PHENOLITE TD-2131" and "PHENOLITE TD-2090" (trade name) manufactured by DIC Corporation, and "GPH-65" and "GPH-103" manufactured by Nippon Kayaku Co., Ltd. "(Product name) and the like.

Examples of amine-based compounds (amine-based curing agents) include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and pentaethylenehexamine, metaxylylene diamine, and diaminodiphenylmethane. Aperamic polyamines such as phenylenediamine, alicyclic polyamines such as 1,3-bis (aminomethyl) cyclohexane, isophoronediamine, norbornandiamine, etc., dimers of dicyandiamide and linolenic acid, and polyamide synthesized from ethylenediamine. Resin is mentioned.

The curing agent is preferably an acid anhydride-based curing agent from the viewpoint of heat resistance of the external quantum efficiency of the cured product of the ink composition, and from the viewpoint of the curing property of the cured product of the ink composition and the viscosity stability of the ink composition. Therefore, a phenolic curing agent is desirable.

The content of the curing agent is, for example, 40 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 in the ink composition. It may be 10 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, or 10 parts by mass or less. The content of the curing agent is, for example, 1 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 in the ink composition. It may be 3 parts by mass or more, and may be 3 parts by mass or more.

[Curing accelerator (curing catalyst)]
Examples of the curing accelerator (curing catalyst) used for curing the thermosetting resin include phosphorus compounds, tertiary amine compounds, imidazole compounds, organic acid metal salts, Lewis acids, amine complex salts and the like. .. Examples of phosphorus-based compounds include triphenylphosphine, triparatrilphosphine, diphenylcyclohexylphosphine, and methyltributylphosphonium iodide. Examples of the tertiary amine compound include N, N-dimethylbenzylamine, 1,8-diazabicyclo (5,4,0) undecene-7, 1,5-diazabicyclo (4,3,0) nonene-5, and tris. (Dimethylaminomethyl) phenol can be mentioned. 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 that a highly reliable pixel portion (cured product of the ink composition) can be easily obtained. When the thermosetting resin is alkali-insoluble, the amount of the thermosetting resin dissolved in 1% by mass of a potassium hydroxide aqueous solution at 25 ° C. is 30% by mass or less based on the total mass of the thermosetting resin. Means that. The dissolved amount of the thermosetting resin is preferably 10% by mass or less, and more preferably 3% by mass or less.

In the present embodiment, the ink composition may contain at least one of the photopolymerizable compound and the thermosetting resin, and may contain both the photopolymerizable compound and the thermosetting resin. .. When the ink composition contains a photopolymerizable compound, it does not have to contain a thermosetting resin. Further, when the ink composition contains a thermosetting resin, it does not have to contain a photopolymerizable compound. A photopolymerizable compound from the viewpoint of storage stability of an ink composition containing luminescent nanocrystal particles (for example, quantum dots) and durability (wet thermosetting stability, etc.) of a pixel portion (cured product of the ink composition). Of the thermosetting resins, it is preferable to use a thermosetting resin, and the storage stability of the ink composition containing luminescent nanocrystal particles (for example, quantum dots) and the low temperature which is not easily deteriorated by heating of the quantum dots. From the viewpoint of enabling curing in, it is more preferable to use a photoradical polymerizable compound, and from the viewpoint of being able to form a pixel portion (cured product of an ink composition) without being hindered by oxygen in the curing process, photocationic polymerization is possible. It is preferable to use a sex compound.

When the ink composition contains a photopolymerizable compound and a thermosetting resin, the total content of the photopolymerizable compound and the thermosetting resin is determined from the viewpoint that an appropriate viscosity can be easily obtained as the ink composition. From the viewpoint of improving the curability, and from the viewpoint of improving the solvent resistance and abrasion resistance of the pixel portion (cured product of the ink composition), the luminescent nanocrystal particles, the organic ligand, and light in the ink composition. The total content of the polymerizable compound, the thermosetting resin, and the light-scattering particles may be 3 parts by mass or more, 5 parts by mass or more, or 10 parts by mass or more with respect to 100 parts by mass. It may be 15 parts by mass or more, or 20 parts by mass or more. Further, the total content of the photopolymerizable compound and the thermosetting resin does not increase the viscosity of the ink composition too much, and the thickness of the pixel portion does not become too thick for the light conversion function. The total content of the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles in the substance may be 60 parts by mass or less, and may be 40 parts by mass with respect to 100 parts by mass. It may be less than or equal to 20 parts by mass or less.

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

Examples of the material constituting the light-scattering particles include simple metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum and gold; silica, barium sulfate, barium carbonate, calcium carbonate, etc. 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, Metal carbonates such as bismuth carbonate and calcium carbonate; metal hydroxides such as aluminum hydroxide; composite oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, strontium titanate, bismuth hyponitrate Such as metal salts and the like. The light-scattering particles are more than the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, barium titanate, and silica from the viewpoint of excellent ejection stability and the effect of improving external quantum efficiency. It is preferable to contain at least one selected, and more preferably at least one selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide and barium titanate.

The shape of the light-scattering particles may be spherical, filamentous, indefinite, or the like. However, as the light-scattering particles, it is possible to use particles having less directional particle shape (for example, spherical or tetrahedral particles) to improve the uniformity, fluidity and light scattering property of the ink composition. It is preferable in that it can be enhanced and excellent discharge stability can be obtained.

The average particle size (volume average diameter) of the light-scattering particles in the ink composition may be 0.05 μm (50 nm) or more from the viewpoint of excellent ejection stability and the effect of improving external quantum efficiency. , 0.2 μm (200 nm) or more, or 0.3 μm (300 nm) or more. The average particle size (volume average diameter) of the light-scattering particles in the ink composition may be 1.0 μm (1000 nm) or less, or 0.6 μm (600 nm) or less, from the viewpoint of excellent ejection stability. It may be 0.4 μm (400 nm) or less. The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition is 0.05 to 1.0 μm, 0.05 to 0.6 μm, 0.05 to 0.4 μm, 0.2 to 1. It may be 0.0 μm, 0.2 to 0.6 μm, 0.2 to 0.4 μm, 0.3 to 1.0 μm, 0.3 to 0.6 μm, or 0.3 to 0.4 μm. From the viewpoint that such an average particle diameter (volume average diameter) can be easily obtained, the average particle diameter (volume average diameter) of the light-scattering particles used may be 0.05 μm or more, and 1.0 μm or less. You may. In the present specification, the average particle diameter (volume average diameter) of the light-scattering particles in the ink composition is obtained by measuring with a dynamic light-scattering nanotrack particle size distribution meter and calculating the volume average diameter. .. The average particle diameter (volume average diameter) of the light-scattering particles used can be obtained by measuring the particle diameter of each particle with, for example, a transmission electron microscope or a scanning electron microscope, and calculating the volume average diameter.

From the viewpoint that the content of light-scattering particles in the ink composition is superior to the effect of improving external quantum efficiency, luminescent nanocrystal particles, organic ligands, photopolymerizable compounds, thermosetting resins, and light in the ink composition. The total content of the scattering particles may be 0.1 part by mass or more, 1 part by mass or more, 5 parts by mass or more, or 7 parts by mass or more with respect to 100 parts by mass. It may be 10 parts by mass or more, or 12 parts by mass or more. The content of the light-scattering particles is determined from the viewpoint of excellent ejection stability and the effect of improving the external quantum efficiency, such as luminescent nanocrystal particles, an organic ligand, a photopolymerizable compound, and a thermosetting resin in the ink composition. , And the total content of the light-scattering particles may be 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, and 30 parts by mass or less with respect to 100 parts by mass. It may be 25 parts by mass or less, 20 parts by mass or less, or 15 parts by mass or less. When the ink composition contains a polymer dispersant, the light-scattering particles can be dispersed well even when the content of the light-scattering particles is relatively large (for example, when the content is about 60 parts by mass). it can.

The mass ratio of the content of light-scattering particles to the content of luminescent nano-crystal particles (light-scattering particles / luminescent nano-crystal particles) is 0.01 or more from the viewpoint of excellent effect of improving external quantum efficiency. It may be 0.02 or more, 0.05 or more, 0.07 or more, 0.1 or more, 0.2 or more, 0. It may be 5.5 or more. The mass ratio (light scattering particles / luminescent nanocrystal particles) may be 5.0 or less from the viewpoint of excellent effect of improving external quantum efficiency and excellent continuous ejection property (ejection stability) during inkjet printing. , 2.0 or less, or 1.5 or less.

The content of the inorganic component in the ink composition (for example, the total amount of the luminescent nanocrystal particles and the light scattering particles) is determined from the viewpoint that an appropriate viscosity can be easily obtained as the ink composition. With respect to the total content of 100 parts by mass of the crystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably. It is 20 parts by mass or more. The content of the inorganic component in the ink composition (for example, the total amount of the luminescent nanocrystal particles and the light scattering particles) is determined from the viewpoint that an appropriate viscosity can be easily obtained as the ink composition. The total content of the crystal particles, the organic ligand, the photopolymerizable compound, the thermosetting resin, and the light scattering particles is preferably 80 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 50 parts by mass, based on 100 parts by mass. It is 40 parts by mass or less. The content of the inorganic component in the ink composition (for example, the total amount of the luminescent nanocrystal particles and the light scattering particles) is determined by the luminescent nanocrystal particles, the organic ligand, the photopolymerizable compound, and the thermocurable property in the ink composition. The total content of the resin and the light-scattering particles may be 5 to 80 parts by mass, 10 to 50 parts by mass, or 20 to 40 parts by mass with respect to 100 parts by mass.

The ink composition may further contain components other than the above-mentioned components as long as the effects of the present invention are not impaired. Examples of other components include polymer dispersants, solvents, antioxidants and the like.

[Polymer dispersant]
The polymer dispersant is a polymer compound having a weight average molecular weight of 750 or more and having a functional group having an affinity for light-scattering particles. The polymer dispersant has a function of dispersing light-scattering particles. The polymer dispersant is adsorbed on the light-scattering particles via a functional group having an affinity for the light-scattering particles, and the light-scattering particles are generated by electrostatic repulsion and / or steric repulsion between the polymer dispersants. Disperse in the ink composition. The polymer dispersant is preferably bonded to the surface of the light-scattering particles and adsorbed on the light-scattering particles, but is bonded to the surface of the luminescent nanoparticles and adsorbed on the luminescent nanoparticles. It may be free in the ink composition.

Examples of the functional group having an affinity for the light scattering particles include an acidic functional group, a basic functional group and a nonionic functional group. The acidic functional group has a dissociative proton and may be neutralized with a base such as an amine or a hydroxide ion, and the basic functional group is neutralized with an acid such as an organic acid or an inorganic acid. You may.

As the acidic functional group, a carboxyl group (-COOH), a sulfo group (-SO ₃ H), a sulfate group (-OSO ₃ H), a phosphonic acid group (-PO (OH) ₃ ), and a phosphoric acid group (-OPO (-OPO)). OH) ₃ ), phosphinic acid group (-PO (OH)-), mercapto group (-SH) can be mentioned.

Examples of the basic functional group include primary, secondary and tertiary amino groups, ammonium groups, imino groups, and nitrogen-containing heterocyclic groups such as pyridine, pyrimidine, pyrazine, imidazole, and triazole.

The nonionic functional group, hydroxy group, an ether group, a thioether group, a sulfinyl group (-SO-), a sulfonyl group _(-SO 2 -), a carbonyl group, a formyl group, an ester group, carbonic ester group, an amide group, Examples thereof include a carbamoyl group, a ureido group, a thioamide group, a thioureide group, a sulfamoyl group, a cyano group, an alkenyl group, an alkynyl group, a phosphine oxide group and a phosphine sulfide group.

The polymer dispersant may be a polymer of a single monomer (homopolymer) or a copolymer of a plurality of types of monomers (copolymer). Moreover, the polymer dispersant may be any of a random copolymer, a block copolymer, and a graft copolymer. When the polymer dispersant is a graft copolymer, it may be a comb-shaped graft copolymer or a star-shaped graft copolymer. The polymer dispersant may be, for example, acrylic resin, polyester resin, polyurethane resin, polyamide resin, polyether, phenol resin, silicone resin, polyurea resin, amino resin, epoxy resin, polyamine such as polyethyleneimine and polyallylamine, and polyimide. It may be there.

Commercially available products can be used as the polymer dispersant, and the commercially available products include Ajinomoto Fine-Techno Co., Ltd.'s Ajispar PB series, BYK's DISPERBYK series and BYK-series, and BASF's Efka series. Etc. can be used.

Examples of commercially available polymer dispersants include "DISPERBYK-130", "DISPERBYK-161", "DISPERBYK-162", "DISPERBYK-163", "DISPERBYK-164", and "DISPERBYK-166" manufactured by Big Chemie. , "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-2022" -2025, "DISPERBYK-2050", "DISPERBYK-2070", "DISPERBYK-2096", "DISPERBYK-2150", "DISPERBYK-2155", "DISPERBYK-2163", "DISPERBYK-2164", "BYK-LPN21" "BYK-LPN6919"; BASF's "EFKA4010", "EFKA4015", "EFKA4046", "EFKA4047", "EFKA4061", "EFKA4080", "EFKA4300", "EFKA4310", "EFKA4310", "EFKA4310" , "EFKA4340", "EFKA4560", "EFKA4585", "EFKA5207", "EFKA1501", "EFKA1502", "EFKA1503" and "EFKAPX-4701"; , "Sol Sparse 13240", "Sol Sparse 13650", "Sol Sparse 13940", "Sol Spur 11200", "Sol Sparse 13940", "Sol Sparse 16000", "Sol Sparse 17000", "Sol Sparse 18000", "Sol Sparse 20000", "Sol Sparse 21000" , "Solspers 24000", "Solspers 26000", "Solspers 27000", "Solspers 28000", "Solspa" "Sols 32000", "Solss 32500", "Solss 32550", "Solss 32600", "Solss 33000", "Solss 34750", "Solss 35100", "Solss 35200", "Solss 36000", "Solss 37500", "Solspur 38500", "Solspers 39000", "Solspers 41000", "Solspers 54000", "Solspers 71000" and "Solspers 76500"; "Ajispar PB821", "Ajispar PB822", "Ajispar PB881" manufactured by Ajinomoto Fine-Techno Co., Ltd. , "PN411" and "PA111"; Evonik's "TEGO Dispers 650", "TEGO Dispers 660C", "TEGO Dispers 662C", "TEGO Dispers 670", "TEGO Dispers 685", "TEGO Dispers 685", "TEGO Dispers 685", "TEGO Dispers 685" "TEGO Dispers 760W"; "Disparon DA-703-50", "DA-705" and "DA-725" manufactured by Kusumoto Kasei can be used.

[solvent]
Examples of the solvent include ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol dibutyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, and diethyl succinate. , 1,4-Butanediol diacetate, glyceryl triacetate and the like.

The boiling point of the solvent under atmospheric pressure is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of continuous ejection of the ink composition. Further, when forming the pixel portion, it is necessary to remove the solvent from the ink composition before curing the ink composition. 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. is there.

In the ink composition of the present embodiment, since the photopolymerizable compound also functions as a dispersion medium, it is possible to disperse light-scattering particles and luminescent nanocrystal particles without a solvent. In this case, there is an advantage that the step of removing the solvent by drying when forming the pixel portion becomes unnecessary.

[Antioxidant]
The ink composition may further contain an antioxidant. In this case, the quantum yield can be improved and the decrease in the quantum yield over time can be further suppressed. The antioxidant may be, for example, a phosphite ester compound, a thioether compound, or the like, and is preferably a phosphite ester from the viewpoint of improving the quantum yield and further suppressing a decrease in the quantum yield over time. It is a compound.

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

In formula (2), R ¹ , R ² and R ³ each independently represent a monovalent organic group. Two species selected from R ¹ , R ² and R ³ may be bonded to each other to form a ring.

Specific examples of the compound represented by the formula (2) include triphenyl phosphite (triphenylphosphine), 2-ethylhexyldiphenylphosphine, diphenyloctylphosphine and the like.

The phosphite triester compound may be liquid or solid at room temperature (25 ° C.), but is preferably compatible with other components (photopolymerizable compound, etc.) in the ink composition. It is a liquid at room temperature (25 ° C.) from the viewpoint of sufficiently satisfying the required performance peculiar to the ink composition and further suppressing a decrease in the quantum yield of the ink composition. The melting point of the phosphorous acid triester compound may be 20 ° C. or lower, or 10 ° C. or lower.

The content of the antioxidant is the ink composition 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 in the ink composition. From the viewpoint of further suppressing the decrease in the quantum yield of the substance, it may be 0.01 part by mass or more, 0.1 part by mass or more, or 1 part by mass or more. It may be parts by mass or more. Since the decrease in quantum yield can be more effectively suppressed even when added in a small amount, the content of the antioxidant is such that the luminescent nanocrystalline particles, the organic ligand, the photopolymerizable compound, and the thermosetting property in the ink composition. With respect to the total content of the resin and the light-scattering particles of 100 parts by mass, it is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, still more preferably 5 parts by mass or less, and even more preferably. Is 3 parts by mass or less. When the content of the antioxidant is within the above range, better film strength can be ensured when the coating film is formed, and bleeding of the antioxidant to the surface is more suppressed and good. It is possible to secure various optical characteristics.

When the ink composition contains a photopolymerizable compound, the content of the antioxidant is based on 100 parts by mass of the photopolymerizable compound from the viewpoint that a decrease in the quantum yield of the ink composition is further suppressed. It may be 0.01 part by mass or more, 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. There may be. Since the decrease in quantum yield can be more effectively suppressed even if a small amount is added, the content of the antioxidant may be 10 parts by mass or less, and 7 parts by mass with respect to 100 parts by mass of the photopolymerizable compound. It may be less than a part or less than 5 parts by mass. When the content of the antioxidant is within the above range, better film strength can be ensured when the coating film is formed, and bleeding of the antioxidant to the surface is further suppressed and good. It tends to be possible to secure various optical characteristics.

The viscosity of the ink composition described above at the ink temperature (for example, the temperature range of 25 to 40 ° C.) during inkjet printing may be, for example, 2 mPa · s or more from the viewpoint of ejection stability during inkjet printing. It may be 5 mPa · s or more, or 7 mPa · s or more. The viscosity of the ink composition at the ink temperature (for example, the temperature range of 25 to 40 ° C.) during inkjet printing may be 20 mPa · s or less, 15 mPa · s or less, or 12 mPa · s or less. You may. The viscosity of the ink composition at the ink temperature (for example, the temperature range of 25 to 40 ° C.) during inkjet printing is, for example, 2 to 20 mPa · s, 2 to 15 mPa · s, 2 to 12 mPa · s, 5 to 20 mPa · s. , 5 to 15 mPa · s, 5 to 12 mPa · s, 7 to 20 mPa · s, 7 to 15 mPa · s, or 7 to 12 mPa · s. For example, the viscosity of the ink composition at 40 ° C. may be in the above range. In the present specification, the viscosity of the ink composition is, for example, the viscosity measured by an E-type viscometer.
It is more preferable that the viscosity at 25 ° C. is 30 mPa · s or less as the viscosity within the above viscosity range in the temperature range of 25 to 40 ° C.

When the viscosity of the ink composition at the ink temperature during inkjet printing is 2 mPa · s or more, the meniscus shape of the ink composition at the tip of the ink ejection hole of the ejection head is stable, so that the ejection control of the ink composition (for example, Control of discharge amount and discharge timing) becomes easy. On the other hand, when the viscosity of the ink composition at the ink temperature during inkjet printing is 20 mPa · s or less, the ink composition can be smoothly ejected from the ink ejection holes.

The surface tension of the ink composition is preferably a surface tension suitable for the inkjet method, specifically, preferably in the range of 20 to 40 mN / m, and more preferably 25 to 35 mN / m. .. By setting the surface tension within this range, discharge control (for example, control of discharge amount and discharge timing) can be facilitated, and the occurrence of flight bending can be suppressed. The flight bending means that when the ink composition is ejected from the ink ejection holes, the landing position of the ink composition deviates from the target position by 30 μm or more. When the surface tension is 40 mN / m or less, the shape of the meniscus at the tip of the ink ejection hole is stable, so that the ejection control of the ink composition (for example, control of the ejection amount and the ejection timing) becomes easy. On the other hand, when the surface tension is 20 mN / m or more, it is possible to prevent the peripheral portion of the ink ejection hole from being contaminated with the ink composition, so that the occurrence of flight bending can be suppressed. That is, a pixel portion formed by not accurately landing on the pixel portion forming region to be landed may be insufficiently filled with the ink composition, or a pixel portion forming region (or pixel portion) adjacent to the pixel portion forming region to be landed may be generated. The ink composition does not land on the surface and the color reproducibility does not deteriorate.

The ink composition of the present embodiment is preferably applied to a piezojet type inkjet recording device using a mechanical ejection mechanism using a piezoelectric element. In the piezo jet method, the ink composition is not instantaneously exposed to a high temperature during ejection. Therefore, alteration of the luminescent nanocrystal particles is unlikely to occur, and the expected luminescence characteristics can be more easily obtained in the pixel portion (light conversion layer).

When the ink composition of the present embodiment is prepared so that the pixel portion (light conversion layer) after curing has, for example, a light conversion layer thickness of 15 um, the leakage rate of blue light as a backlight is 10% or less. Is preferable. By setting the leakage rate of blue light from the pixel portions to 10% or less, the color purity of each pixel portion can be increased, and the color gamut of the display can be increased. The leakage rate of blue light can be measured by a general spectroscope, for example, the multi-channel spectroscope MCPD-9800 manufactured by Otsuka Electronics Co., Ltd., and can be defined by the following formula.

Blue leaked light = number of blue light photons leaking from the pixel section / number of blue light photons incident on the pixel section

The blue light has an emission peak in the range of 420 to 480 nm, and preferably has an emission peak in the range of 440 to 470 nm and 440 to 460 nm.

It suppresses the coating film of the ink composition from absorbing moisture in the atmosphere, and suppresses the decrease in luminescence (for example, fluorescence) of luminescent nanocrystal particles (quantum dots, etc.) over time. From the viewpoint, in the present embodiment, the coating film of the ink composition is preferably alkali-insoluble. That is, the ink composition of the present embodiment is preferably an ink composition capable of forming an alkali-insoluble coating film. Such an ink composition can be obtained by using an alkali-insoluble photopolymerizable compound and / or an alkali-insoluble thermosetting resin as the photopolymerizable compound and / or the thermosetting resin. The fact that the coating film of the ink composition is alkali-insoluble means that the amount of the coating film of the ink composition dissolved at 25 ° C. in a 1% by mass potassium hydroxide aqueous solution is based on the total mass of the coating film of the ink composition. It means that it is 30% by mass or less. The amount of the coating film of the ink composition dissolved is preferably 10% by mass or less, and more preferably 3% by mass or less. The fact that the ink composition is an ink composition capable of forming an alkali-insoluble coating film means that the thickness is obtained by applying the ink composition on a substrate and then drying it at 80 ° C. for 3 minutes. It can be confirmed by measuring the above-mentioned dissolution amount of the 1 μm coating film.

<Manufacturing method of ink composition>
The ink composition of the above-described embodiment can be obtained, for example, by mixing the constituent components of the above-mentioned ink composition and performing a dispersion treatment.

The method for producing the ink composition is, for example, a first step of preparing a dispersion of light-scattering particles containing light-scattering particles, and mixing the dispersion of light-scattering particles and luminescent nanocrystal particles. A second step is provided. As the luminescent nanocrystal particles, luminescent nanocrystal particles having an organic ligand on the surface thereof are used. That is, the luminescent nanocrystalline particle dispersion further comprises an organic ligand. The dispersion of light-scattering particles may further contain a polymer dispersant. In this method, the dispersion of the light scattering particles may further contain the photopolymerizable compound and / or the thermosetting resin, and in the second step, the photopolymerizable compound and / or the thermosetting resin is further mixed. You may. According to this method, the light scattering particles can be sufficiently dispersed. Therefore, the optical characteristics of the pixel portion can be improved, and an ink composition having excellent ejection stability can be easily obtained.

In the step of preparing a dispersion of light-scattering particles, the light-scattering particles, in some cases, a polymer dispersant, and a photopolymerizable compound and / or a thermosetting resin are mixed and dispersed. May prepare a dispersion of light scattering particles. The mixing and dispersion treatment may be carried out using a dispersion device such as a bead mill, a paint conditioner, a planetary stirrer, or a jet mill. It is preferable to use a bead mill or a paint conditioner from the viewpoint that the dispersibility of the light-scattering particles is good and the average particle size of the light-scattering particles can be easily adjusted to a desired range. 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. Therefore, excellent ejection stability and excellent external quantum efficiency can be obtained more easily.

The method for producing an ink composition may further include a step of preparing a dispersion of luminescent nanocrystal particles containing the luminescent nanocrystal particles and an organic solvent before the second step. In this case, in the second step, the dispersion of the light-scattering particles and the dispersion of the luminescent nanocrystal particles are mixed. In the step of preparing the dispersion of the luminescent nanocrystal particles, the luminescent nanocrystal particle dispersion may be prepared by mixing the luminescent nanocrystal particles and the organic solvent and performing a dispersion treatment. The mixing and dispersion treatment may be carried out using a dispersion device such as a bead mill, a paint conditioner, a planetary stirrer, or a jet mill. It is preferable to use a bead mill, a paint conditioner or a jet mill from the viewpoint that the dispersibility of the luminescent nanocrystal particles is improved and the average particle size of the luminescent nanocrystal particles can be easily adjusted to a desired range. According to this method, the luminescent nanocrystal particles can be sufficiently dispersed. Therefore, the optical characteristics of the pixel portion can be improved, and an ink composition having excellent ejection stability can be easily obtained. In the above step, the dispersion of the luminescent nanocrystal particles may further contain a photopolymerizable compound and / or a thermosetting resin.

In this production method, the organic solvent may be blended in the first step or may be blended 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. It may be a step of mixing a dispersion of light-scattering particles, luminescent nanocrystal particles, and an organic solvent.

The method for producing an ink composition further includes a step of mixing an organic solvent with a thermosetting resin and / or a photopolymerizable compound to prepare a solution containing the thermosetting resin and / or the photopolymerizable compound. May be good. 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 step, and the organic solvent are used. May be mixed. That is, the second step may be a step of mixing a solution containing a light-scattering particle dispersion, a luminescent nanocrystal particle dispersion, a thermosetting resin and / or a photopolymerizable compound, and an organic solvent. ..

In this production method, components other than the above-mentioned components 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. Further, other components may be mixed with a composition obtained by mixing a luminescent nanocrystal particle dispersion and a light scattering particle dispersion.

<Ink composition set>
The ink composition set of one embodiment includes the ink composition of the above-described embodiment. The ink composition set may include an ink composition (non-emissive ink composition) that does not contain luminescent nanocrystal particles, in addition to the ink composition (emissive ink composition) of the above-described embodiment. The non-emissive ink composition may be a conventionally known ink composition, and has the same composition as the ink composition (emissive ink composition) of the above-described embodiment except that it does not contain luminescent nanocrystal particles. It may be.

Since the non-luminescent ink composition does not contain luminescent nanocrystal particles, light is incident on the pixel portion formed by the non-luminescent ink composition (the pixel portion containing the cured product of the non-luminescent ink composition). In this case, the light emitted from the pixel portion has substantially the same wavelength as the incident light. Therefore, the non-emissive ink composition is suitably used for forming pixel portions having the same color as the light from the light source. For example, when the light from the light source is light having a wavelength in the range of 420 to 480 nm (blue light), the pixel portion formed by the non-emissive ink composition can be a blue pixel portion.

The non-emissive ink composition preferably contains light-scattering particles. When the non-emissive ink composition contains light-scattering particles, the pixel portion formed by the non-emissive ink composition can scatter the light incident on the pixel portion, whereby the pixel It is possible to reduce the difference in light intensity of the light emitted from the unit at the viewing angle.

<Optical conversion layer and color filter, and their manufacturing method>
Hereinafter, details of the light conversion layer and the color filter obtained by using the ink composition set of the above-described embodiment will be described with reference to the drawings. In the following description, the same reference numerals will be used for the same or equivalent elements, and duplicate description will be omitted.

FIG. 1 is a schematic cross-sectional view of the color filter of one embodiment. As shown in FIG. 1, the color filter 100 includes a base material 40 and a light conversion layer 30 provided on the base material 40. The light conversion layer 30 includes a plurality of pixel units 10 and a light-shielding unit 20.

The optical conversion layer 30 has a first pixel unit 10a, a second pixel unit 10b, and a third pixel unit 10c as the pixel unit 10. The first pixel portion 10a, the second pixel portion 10b, and the third pixel portion 10c are arranged in a grid pattern so as to repeat in this order. The light-shielding portion 20 is located between adjacent pixel portions, that is, between the first pixel portion 10a and the second pixel portion 10b, between the second pixel portion 10b and the third pixel portion 10c, and the third. It is provided between the pixel portion 10c of the above and the first pixel portion 10a. In other words, these adjacent pixel portions are separated from each other by the light-shielding portion 20.

The first pixel portion 10a and the second pixel portion 10b are luminescent pixel portions (light emitting pixel portions) containing a cured product of the ink composition of the above-described embodiment, respectively. The cured product contains luminescent nanocrystal particles, a cured component, and light scattering particles. The curing component is a component obtained by polymerization of a photopolymerizable compound and / or curing (polymerization, cross-linking, etc.) of a thermosetting resin, and is a polymer of a photopolymerizable compound and / or a cured product of a thermosetting resin. Including. That is, the first pixel portion 10a contains the first curing component 13a and the first luminescent nanocrystal particles 11a and the first light scattering particles 12a dispersed in the first curing component 13a, respectively. Including. Similarly, the second pixel portion 10b includes the second curing component 13b, the second luminescent nanocrystal particles 11b and the second light scattering particles 12b dispersed in the second curing component 13b, respectively. including. 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 may be the same as or different from the first light scattering particles 12a. It may be the same as or different from the second light scattering particle 12b.

The first luminescent nanocrystal particles 11a are red luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having an emission peak wavelength in the range of 605 to 665 nm. That is, the first pixel portion 10a may be rephrased as a red pixel portion for converting blue light into red light. The second luminescent nanocrystal particle 11b is a green luminescent nanocrystal particle that absorbs light having a wavelength in the range of 420 to 480 nm and emits light having an emission peak wavelength in the range of 500 to 560 nm. That is, the second pixel portion 10b may be rephrased as a green pixel portion for converting blue light into green light. It is preferable that the ink composition having Ag, In, Ga and S of the present invention is used for the pixel portion of the green light emission.

The total content of the luminescent nanocrystal particles and the organic ligand in the luminescent pixel portion is 10% by mass or more, 15% by mass or more, 21% by mass or more, and 25% by mass based on the total mass of the luminescent pixel portion. It may be 27% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more or 50% by mass or more, 70% by mass or less, 65% by mass or less, 60% by mass. It may be less than or equal to 55% by mass or less.

The content of the light scattering particles in the luminescent pixel portion may be 0.1% by mass or more based on the total mass of the luminescent pixel portion from the viewpoint of being more excellent in the effect of improving the external quantum efficiency, and may be 1% by mass. It may be more than 3% by mass, may be 3% by mass or more, and may be 5% by mass or more. The content of the light-scattering particles may be 60% by mass or less based on the total mass of the luminescent pixel portion, from the viewpoint of being superior in the effect of improving the external quantum efficiency and the reliability of the pixel portion, and is 50. It may be 10% by mass or less, 40% by mass or less, or 30% by mass or less.

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

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

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

The thickness of the pixel portion (first pixel portion 10a, second pixel portion 10b, and 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, or 6 μm or more. It may be 30 μm or less, or 20 μm or less.

The light-shielding portion 20 is a so-called black matrix provided for the purpose of separating adjacent pixel portions to prevent color mixing and for the purpose of preventing light leakage from a light source. The material constituting the light-shielding portion 20 is not particularly limited, and the curing of the resin composition in which the binder polymer contains light-shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments in addition to a metal such as chromium. Objects and the like can be used. The binder polymer used here includes 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 a reactive silicone) or the like can be used. The thickness of the light-shielding portion 20 may be, for example, 0.5 μm or more, and may be 10 μm or less.

The base material 40 is a transparent base material having light transmission, and is, for example, a transparent glass substrate such as quartz glass, Pyrex (registered trademark) glass, or a synthetic quartz plate, a transparent resin film, a transparent resin film for optics, or the like. A flexible base material or the like can be used. Among these, it is preferable to use a glass substrate made of non-alkali glass that does not contain an alkaline component in the glass. Specifically, "7059 glass", "1737 glass", "Eagle 200" and "Eagle XG" manufactured by Corning Inc., "AN100" manufactured by Asahi Glass Co., Ltd., "OA-10G" and "OA-10G" manufactured by Nippon Electric Glass Co., Ltd. OA-11 ”is suitable. These are materials with a small 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 optical conversion layer 30 is preferably used when a light source that emits light having a wavelength in the range of 420 to 480 nm is used.

The method for manufacturing the light conversion layer 30 (color filter 100) according to one embodiment is partitioned by a step of forming a light-shielding portion 20 on the base material 40 (a light-shielding portion forming step) and a light-shielding portion 20 on the base material 40. A step of arranging the ink composition of the above-described embodiment by an inkjet method (arrangement step) and a step of curing the ink composition (curing step) are provided in the pixel portion forming region.

In the light-shielding portion forming step, the light-shielding portion 20 is formed in a pattern (for example, a grid pattern). Examples of the method of forming the light-shielding portion 20 include a method of forming a metal thin film such as chromium or a thin film of a resin composition containing light-shielding particles on one surface side of the base material 40 and patterning the thin film. Be done. The metal thin film can be formed by, for example, a sputtering method, a vacuum vapor deposition method, or the like. The thin film of the resin composition containing the light-shielding particles can be formed by, for example, a method such as coating or printing. Examples of the patterning method include a photolithography method and the like.

In the arranging step, the ink composition is selectively arranged (adhered) to the pixel portion forming region (the region on the base material 40 where the light-shielding portion 20 is not formed (the opening of the light-shielding portion 20)) by the inkjet method. ). Examples of the inkjet method include a bubble jet (registered trademark) method using an electrothermal converter as an energy generating element, a piezojet method using a piezoelectric element, and the like.

In the curing step, the ink composition arranged by the arrangement step is cured by irradiation or heating with active energy rays.

When the inkjet is cured by irradiation with active energy rays (for example, ultraviolet rays), for example, a mercury lamp, a metal halide lamp, a xenon lamp, an LED or the like may be used as the light source. The wavelength of the light to be irradiated may be, for example, 200 nm or more, and may be 440 nm or less. The exposure amount may be, for example, 10 mJ / cm ² or more and 20000 mJ / cm ² or less.

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

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

In the volatilization step, the solvent (organic solvent) may be volatilized by drying under reduced pressure (drying under reduced pressure). The conditions for drying under reduced pressure may be usually 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.

Although the color filter, the optical conversion layer, and one embodiment of these manufacturing methods have been described above, the present invention is not limited to the above embodiment.

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

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

Further, the color filter may include an ink-repellent layer made of a material having an ink-repellent property narrower than that of the light-shielding portion on the pattern of the light-shielding portion. Further, instead of providing an ink-repellent layer, a photocatalyst-containing layer as a wettable variable layer is formed in a solid coating shape in a region including a pixel portion forming region, and then light is applied to the photocatalyst-containing layer via a photomask. Irradiation and exposure may be performed to selectively increase the ink-friendly property of the pixel portion forming region. Examples of the photocatalyst include titanium oxide and zinc oxide.

Further, the color filter may include an ink receiving layer containing hydroxypropyl cellulose, polyvinyl alcohol, gelatin and the like between the base material and the pixel portion.

Further, the color filter may be provided with a protective layer on the pixel portion. This protective layer flattens the color filter and prevents the components contained in the pixel portion, or the components contained in the pixel portion and the components contained in the photocatalyst-containing layer from being eluted into the liquid crystal layer. It is provided. As the material constituting the protective layer, a material used as a known protective layer for a color filter can be used.

Further, in addition to the above-mentioned luminescent nanocrystal particles, the pixel portion of the light conversion layer of the present embodiment may further contain a pigment having substantially the same color as the luminescent color of the luminescent nanocrystal particles. In order to contain the pigment in the pixel portion, the pigment may be contained in the ink composition.

Further, one or two types of luminescent pixel portions among the red pixel portion (R), the green pixel portion (G), and the blue pixel portion (B) in the optical conversion layer of the present embodiment are luminescent nano. The pixel portion may contain a coloring material without containing crystal particles. As the color material that can be used here, a known color material can be used. For example, as the color material used for the red pixel portion (R), a diketopyrrolopyrrole pigment and / or an anionic red organic dye is used. Can be mentioned. Examples of the coloring material used for the green pixel portion (G) include at least one selected from the group consisting of a copper halide phthalocyanine pigment, a phthalocyanine-based green dye, and a mixture of a phthalocyanine-based blue dye and an azo-based yellow organic dye. Examples of the coloring material used for the blue pixel portion (B) include an ε-type copper phthalocyanine pigment and / or a cationic blue organic dye. The amount of these coloring materials used is 1 to 5 masses based on the total mass of the pixel portion (cured product of the ink composition) from the viewpoint of preventing a decrease in transmittance when contained in the light conversion layer. It is preferably%.

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited to the following examples. All the materials used in the examples were those in which argon gas was introduced and the dissolved oxygen was replaced with argon gas. As for titanium oxide, one which was heated at 175 ° C. for 4 hours under a reduced pressure of 1 mmHg and allowed to cool in an argon gas atmosphere was used before mixing. The liquid material used in the examples was dehydrated with Molecular Sieves 3A for 48 hours or more in advance before mixing.

<Preparation of AIGS nanocrystal particle dispersion>
By adding 4 times the amount of heptane to the AIGS nanocrystal dispersion (AIGS QD inbutyl acetate, nanocrystal dispersion concentration 35%) manufactured by Nanosys, USA, the nanocrystal particles are aggregated and centrifuged. After precipitation, the nanocrystal particles were separated by tilting the supernatant. AIGS by dispersing the obtained nanocrystal particles in 1,6-hexanediol diacrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd., trade name: NK ester A-HD-N, hereinafter also referred to as "HDDA"). A nanocrystal particle dispersion was obtained. The content of the luminescent nanocrystal particle concentration (including the organic ligand) in the dispersion was 50% by mass. As described in SDS, the luminescent nanocrystal particles contained in the AIGS nanocrystal dispersion are composed of silver (Ag), indium (In), gallium (Ga) and sulfur (S).

<Preparation of InP nanocrystal particle dispersion>
The same method as for the preparation of the AIGS nanocrystal particle dispersion except that the nanocrystal particle dispersion was changed to an InP nanocrystal dispersion (Gen3 QD in PGMEA, ver4, nanocrystal particle dispersion concentration 30%) manufactured by Nanosys. Obtained an InP nanocrystal particle dispersion. The content of the luminescent nanocrystal particle concentration (including the organic ligand) in the dispersion was 50% by mass.

<Preparation of light-scattering particle dispersion>
In a container filled with argon gas, 34 g of titanium oxide (trade name: CR-60-2, manufactured by Ishihara Sangyo Co., Ltd., average particle diameter (volume average diameter): 210 nm) and a polymer dispersant (trade name) : After mixing 1.0 g of Ajispar PB-821 and Ajinomoto Fine Techno Co., Ltd. with 35.0 g of HDDA, which is a light-scattering particle dispersion medium, zirconia beads (diameter: 1.25 mm) were added to the obtained mixture. ) Was added, and the mixture was shaken for 2 hours using a paint conditioner to disperse the mixture, and zirconia beads were removed with a polyester mesh filter to obtain a light-scattering particle dispersion.

[Preparation of ink composition]
<Example 1>
7.0 g of AIGS nanocrystal dispersion, 0.7 g of light-scattering particle dispersion 1, 0.12 g of photopolymerization initiator Omnirad TPO-H (manufactured by IGM resin), and photopolymerization initiator Omnirad 819 ( 0.02 g of IGM resin (manufactured by IGM resin), 0.1 g of antioxidant JPE-10 (manufactured by Johoku Kagaku Kogyo) and 2.1 g of HDDA are uniformly mixed in a container filled with argon gas, and then a glove box is used. Inside, the mixture is filtered through a filter with a pore size of 5 μm. Composition 1 was prepared. The compositions of the luminescent nanocrystal particles (including the organic ligand), the photopolymerizable compound, the photopolymerizable initiator, the light diffusing particles, the polymer dispersant and the antioxidant in the composition are as shown in Table 1.

<Example 2>
Same as in Example 1 except that the compounding ratio was changed so that the composition ratios of the nanocrystal particles, the photopolymerization compound, the light scattering particles, the polymer dispersant, the photopolymerization initiator and the antioxidant were as shown in Table 1. Composition 2 was prepared by the method.

<Comparative Examples 1 to 3>
Table 1 shows the composition ratios of the photopolymerization compound, the light scattering particles, the polymer dispersant, the photopolymerization initiator, and the antioxidant, using InP nanocrystal dispersion instead of AIGS nanocrystal dispersion as the nanocrystal particles. The compositions 3 to 5 were adjusted in the same manner as in Example 1 except that the compounding ratio was changed so as to be the same.

[Evaluation of optical characteristics]
[Preparation of evaluation sample]
Each composition was applied on a glass substrate in the air with a spin coater so as to have a film thickness of 15 μm. ^{The coating film is cured by irradiating the coating film with UV so that the integrated light amount is 1500 mJ / cm 2} with a UV irradiation device using an LED lamp having a main wavelength of 395 nm in a nitrogen atmosphere, and a layer (light) made of a cured product is formed on a glass substrate. Conversion layer) was formed. As a result, each evaluation sample, which is a base material having a light conversion layer, was prepared.

[Evaluation of blue leakage light]
A blue LED (peak emission wavelength: 450 nm) manufactured by CCS Inc. was used as the surface emission light source. As the measuring device, an integrating sphere was connected to a radiation spectrophotometer (trade name "MCPD-9800") manufactured by Otsuka Electronics Co., Ltd., and the integrating sphere was installed above the blue LED. A substrate having an optical conversion layer prepared in the same procedure as the above-mentioned curability evaluation was inserted between the blue LED and the integrating sphere, and the spectrum observed by turning on the blue LED and the illuminance at each wavelength were measured.

From the spectrum and illuminance measured by the above measuring device, the optical density (OD @ 450 nm) of the cured product on the glass substrate was determined as follows. This value indicates how much of the blue light (photons) incident on the light conversion layer is absorbed by the light conversion layer. If this value is large, the blue leakage light is small and the QD It is an evaluation index showing that the color reproducibility of −CF is improved.

Blue Transmittance (%) = T (Blue) / E (Blue)
Film OD = -Log ₁₀ (Blue Transfer)

Here, T (Blue) and E (Blue) represent the following, respectively.
T (Blue): Shows the total value of "illuminance x wavelength ÷ hc" after the film is placed in the wavelength region of 380 to 490 nm.
E (Blue): Shows the total value of "illuminance x wavelength ÷ hc" before mounting the film in the wavelength region of 380 to 490 nm.

[Evaluation of viscosity of ink composition and thickening in air atmosphere]
The evaluation of the viscosity of the ink compositions of Examples and Comparative Examples was carried out by measuring the viscosity at 25 ° C. using an E-type viscometer.

As can be seen from the above table, since the ink composition of the present invention uses luminescent nanocrystal particles having specific constituent elements, it is possible to combine good film OD and good ink viscosity, and further, a smaller amount of luminescent particles. Excellent film OD can be obtained by using nanocrystal particles.
It can be seen that in the conventional luminescent nanoparticles, the film OD can be increased by increasing the amount of light diffusing particles, but the ink viscosity becomes high.

10 ... Pixel part, 10a ... First pixel part, 10b ... Second pixel part, 10c ... Third pixel part, 11a ... First luminescent nanocrystal particles, 11b ... Second luminescent nanocrystal particles , 12a ... 1st light-scattering particles, 12b ... 2nd light-scattering particles, 12c ... 3rd light-scattering particles, 20 ... light-shielding part, 30 ... light conversion layer, 40 ... base material, 100 ... color filter.

Claims (5)

An ink composition containing luminescent nanocrystal particles, a photopolymerizable compound and / or a thermosetting resin, and light scattering particles.
At least a part of the luminescent nanocrystal particles absorbs light having a wavelength in the range of 420 to 480 nm, has an emission peak in the range of 500 to 560 nm, and emits light having Ag, In, Ga and S as constituent elements. An ink composition that is sex nanocrystal particles. The ink composition according to claim 1, wherein the viscosity at 25 ° C. is 30 mPa · s or less. The ink composition according to claim 1 or 2, wherein when a light conversion layer having a thickness of 15 um is produced, the leakage rate of blue light is 10% or less. A plurality of pixel portions and a light-shielding portion provided between the plurality of pixel portions are provided.
The plurality of pixel portions are light conversion layers having a light emitting pixel portion containing a cured product of the ink composition according to any one of claims 1 to 3. A color filter comprising the light conversion layer according to claim 3.

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