JP7024383B2 - Ink composition, light conversion layer and color filter - Google Patents

Description

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

Conventionally, a color filter pixel portion in a display such as a liquid crystal display device uses, for example, a curable resist material containing red organic pigment particles or green organic pigment particles and an alkali-soluble resin and / or an acrylic monomer. , Has been manufactured by photolithography.

In recent years, there has been a strong demand for lower power consumption of displays, and instead of the red organic pigment particles or green organic pigment particles, luminescent nanocrystal particles such as quantum dots, quantum rods, and other inorganic phosphor particles have been strongly demanded. A method of forming a color filter pixel portion such as a red pixel and a green pixel by using the above is actively studied.

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 forming the pixel portion of the optical conversion substrate by the inkjet method, it is desirable that the ejection stability is excellent. Further, when a color filter pixel portion (hereinafter, also simply referred to as “pixel portion”) is formed by an ink composition using luminescent nanocrystal particles such as quantum dots, the quantum dots are unstable and thus serve as a binder. Depending on the type of resin used, for example, storage at room temperature in air may reduce the external quantum efficiency (EQE: External Quantum Efficiency) over time.

Therefore, an object of the present invention is to provide an ink composition having excellent ejection stability and capable of suppressing a decrease in external quantum efficiency, and an optical conversion layer and a color filter using the ink composition.

One aspect of the present invention comprises luminescent nanocrystal particles, a monomer having an ethylenically unsaturated group, a photopolymerization initiator, and a thiol compound having two or three primary mercapto groups. Regarding the ink composition.

The content of the photopolymerization initiator may be 0.1 to 5.0% by mass based on the mass of the non-volatile content of the ink composition.

The ink composition may further contain light scattering particles. The average particle size of the light-scattering particles may be 0.05 to 1.0 μm. Further, the light-scattering particles may contain at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate and barium titanate.

The ink composition may further contain a polymer dispersant. The weight average molecular weight of this polymer dispersant may be 1000 or more.

The luminescent nanocrystal particles may have an organic ligand on their surface.

The monomer having an ethylenically unsaturated group may be alkaline insoluble.

The ink composition may be an ink composition capable of forming an alkali-insoluble coating film.

The surface tension of the ink composition may be 20-40 mN / m.

The viscosity of the ink composition at 40 ° C. may be 2 to 20 mPa · s.

The ink composition may be for a color filter.

The ink composition may be an ink composition (inkjet ink) used in an inkjet method.

One aspect of the present invention relates to an optical conversion layer including a plurality of pixel portions, wherein the plurality of pixel portions have pixel portions including a cured product of the ink composition described above. In this optical conversion layer, the decrease in the external quantum efficiency of the pixel portion is suppressed.

The optical conversion layer may further include a light-shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions contain the above-mentioned cured product and have a wavelength in the range of 420 to 480 nm as luminescent nanocrystal particles. The first pixel portion containing the light-emitting nanocrystal particles that absorb the light of the above and emit light having a light emission peak wavelength in the range of 605 to 665 nm, and the cured product, and as the light-emitting nanocrystal particles. It may have a second pixel portion containing luminescent nanoparticles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a emission peak wavelength in the range of 500 to 560 nm.

The plurality of pixel portions may further include a third pixel portion having a transmittance of 30% or more with respect to light having a wavelength in the range of 420 to 480 nm.

One aspect of the present invention relates to a color filter including the above-mentioned optical conversion layer. In this color filter, the decrease in the external quantum efficiency of the pixel portion is suppressed.

According to the present invention, it is an object of the present invention to provide an ink composition having excellent ejection stability and capable of suppressing a decrease in external quantum efficiency, and an optical conversion layer and a color filter using the ink composition.

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 monomer having an ethylenically unsaturated group, a photopolymerization initiator, and a thiol compound having two or three primary mercapto groups. do. The ink composition of one embodiment is an ink composition for a color filter used for forming a pixel portion of a color filter by, for example, a photolithography method, an inkjet method, or the like.

By the way, when a color filter pixel portion is formed by an inkjet method using a conventional ink composition, it is difficult to achieve both excellent ejection stability and excellent curability. Therefore, it has been more difficult to obtain a color filter pixel portion in which a decrease in external quantum efficiency is suppressed by an inkjet method. On the other hand, according to the ink composition of the embodiment, it is possible to obtain a color filter pixel portion in which a decrease in external quantum efficiency is suppressed even by an inkjet method.

The ink composition can be applied as an ink used in a known and conventional method for manufacturing a color filter, but it is necessary without wasting materials such as luminescent nanocrystal particles and a solvent, which are relatively expensive. It is preferable to appropriately prepare and use the color filter so as to be suitable for the inkjet method rather than the photolithography method in that the color filter pixel portion (optical conversion layer) can be formed only by using the necessary amount. That is, the ink composition is suitably used for forming a color filter pixel portion by an inkjet method.

Hereinafter, a thiol compound having a luminescent nanocrystal particle, a monomer having an ethylenically unsaturated group, a photopolymerization initiator, and two or three primary mercapto groups (hereinafter, also simply referred to as “thiol compound”). A color filter ink composition (color filter inkjet ink) containing () and, which is used in an inkjet method, will be described as an example.

[Luminescent 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 (red light) having a emission peak wavelength in the range of 605 to 665 nm, and may be 500 to 560 nm. It may be green light emitting nanocrystal particles (green light 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 light emitting nanocrystal particles (blue light emitting nanocrystal particles). In this embodiment, it is preferable that the ink composition contains at least one of these luminescent nanocrystal particles. The light absorbed by the luminescent nanocrystal particles may be, for example, light having a wavelength in the range of 400 nm or more and less than 500 nm (blue light) or light having a wavelength in the range of 200 nm to 400 nm (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 by 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 of 528 nm or more, 525 nm or more, 523 nm or more, 520 nm or more, 515 nm or more, 510 nm or more, 507 nm or more, 505 nm or more, 503 nm or more, or 500 nm or more.

Blue-emitting 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 (for example, particle size) of the luminescent nanocrystal particles 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 include a third semiconductor material different from the first and second semiconductor materials in addition to the shell (first shell) containing the second semiconductor material, and the above-mentioned core. It may further have a shell (second shell) that covers at least a part of it. In other words, the structure of the luminescent semiconductor nanocrystal particles may be a structure including a core, a first shell, and a second shell (core / shell / shell structure). 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.).

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, HgSeDZn. CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSeTe, CdHgSeTe, AlHgSe InP, InAs, InSb, COLP, PLGAs, VMwareSb, 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, SnSeTe, SnSe, PbSnPbSn 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. CdS, CdSe, CdTe, ZnS, 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. ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS ₂ , AgInSe ₂ , AgInTe ₂ , AgGaS ₂ , _{AgGaSe 2} , _AgGaS2 , AgGaSe ₂ , _AgGaS2 , CuGaS ₂ , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge and Cu ₂ ZnSnS ₄ preferably comprises at least one selected from the group.

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, the shell portion is ZnS and the inner core portion is InP, and the nanocrystal particles have a core / shell structure. The shell portion is a mixed crystal of ZnS and ZnSe and the inner core portion is InP nanocrystal particles, the mixed crystal nanocrystal particles of CdSe and CdS, the mixed crystal nanocrystal particles of ZnSe and CdS, and the 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 with 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-emitting semiconductor nanocrystal particles include CdSe nanocrystal particles, mixed-crystal nanocrystal particles of CdSe and ZnS, and nanocrystal particles having a core / shell structure, wherein the shell portion is ZnS. Nanocrystal particles whose inner core is InP, nanocrystal particles 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, 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 portion is a mixed crystal of ZnS and ZnSe, the second shell portion is ZnS, and the inner core portion 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 of CdS, nanocrystal particles having a core / shell structure, and the shell portion is ZnS and the inner core portion is InP. Nanocrystal particles having a structure, wherein 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 as such, which 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 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, disc-shaped, branched, net-shaped, rod-shaped, or the like. However, as the luminescent nanocrystal particles, using particles having less directionality as the particle shape (for example, particles having a spherical shape, a regular tetrahedron shape, etc.) 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.

From the viewpoint of dispersion stability, the luminescent nanocrystal particles preferably have an organic ligand on the surface thereof. 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. Further, 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 jet ink is used, it is preferable that the polymer dispersant is blended with the luminescent nanocrystal particles in which the organic ligand is coordinated.

The organic ligand includes a monomer having an ethylenically unsaturated group, a functional group for ensuring affinity with an organic solvent (hereinafter, also simply referred to as "affinity group"), and adsorption to luminescent nanoparticles. It is preferable that the compound has a functional group for ensuring the property (hereinafter, also simply referred to as “adsorption group”). As the affinity group, an aliphatic hydrocarbon group is preferable. 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. Examples of the adsorption group include a hydroxyl group, an amino group, a carboxyl group, a thiol group, a phosphoric acid group, a phosphonic acid group, a phosphin group, a phosphin oxide group, an alkoxysilyl group and the like. Examples of the organic ligand include TOP (trioctylphosphine), TOPO (trioctylphosphine oxide), oleic acid, oleylamine, octylamine, trioctylamine, hexadecylamine, octanethiol, dodecanethiol, and hexylphosphonic acid (HPA). , Tetradecylphosphonic acid (TDPA), and octylphosphic acid (OPA).

The organic ligand preferably has an aliphatic hydrocarbon having an ethylene oxide chain as an affinity group from the viewpoint of improving the dispersibility of the luminescent nanocrystal particles and obtaining more excellent ejection stability. Specifically, it may be an organic ligand represented by the following formula (1). The organic ligand may or may not have a propylene oxide chain as an affinity group.

In equation (1), p represents an integer of 0 or more. p is preferably an integer of 1 or more, and may be an integer of 50 or less.

As the luminescent nanocrystal particles, those dispersed in a colloidal form in an organic solvent, a monomer having an ethylenically unsaturated group, or the like can be used. The surface of the luminescent nanocrystal particles dispersed in the 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, or a mixture thereof.

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 is the non-volatile content of the ink composition from the viewpoint of further improving the ejection stability, further reducing the leakage light, and further suppressing the decrease in the external quantum efficiency. Based on the mass, it may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. When the content of the luminescent nanocrystal particles is 5% by mass or more, excellent luminescence intensity can be obtained, so that such an ink composition is suitably used for color filter applications. The content of the luminescent nanocrystal particles may be 50% by mass or less, 40% by mass or less, or 35% by mass or less, based on the mass of the non-volatile content of the ink composition, from the viewpoint of being more excellent in ejection stability. It may be 1% by mass or less, and may be 30% by mass or less. When the content of the luminescent nanocrystal particles is 50% by mass or less, excellent luminescence intensity can be obtained, so that such an ink composition is suitably used for color filter applications. The content of the luminescent nanocrystal particles is 5 to 50% by mass, 10 to 50% by mass, 15 to 40% by mass, 15 to 35% by mass, and 20 to 35% by mass based on the mass of the non-volatile content of the ink composition. It may be% or 20 to 30% by mass. In the present specification, the "mass of the non-volatile component of the ink composition" refers to the mass obtained by subtracting the mass of the solvent from the total mass of the ink composition when the ink composition contains a solvent, and the ink composition refers to the ink composition. In the absence of solvent, it refers to the total mass of the ink composition.

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 luminescent nanocrystal particles contain red luminescent nanocrystal particles, the content of the green luminescent nanocrystal particles and the content of the blue luminescent nanocrystal particles are preferably based on the total mass of the luminescent nanocrystal particles. Is 10% by mass or less, more preferably 0% by mass. When the luminescent nanocrystal particles contain green luminescent nanocrystal particles, the content of the red luminescent nanocrystal particles and the content of the blue luminescent nanocrystal particles are preferably based on the total mass of the luminescent nanocrystal particles. Is 10% by mass or less, more preferably 0% by mass.

[Monomer having an ethylenically unsaturated group]
A monomer having an ethylenically unsaturated group (hereinafter, also referred to as “ethylenically unsaturated monomer”) is a photopolymerizable compound that polymerizes by irradiation with light. 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 a functional group containing an ethylenically unsaturated group such as a vinyl group, a vinylene group, a vinylidene group, and a (meth) acryloyl group. Monomers having these functional groups may be referred to as "vinyl monomers". In addition, in this specification, "(meth) acryloyl group" means "acryloyl group" and the corresponding "methacryloyl group". The same applies to the expressions "(meth) acrylate" and "(meth) acrylamide".

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 ethylenically unsaturated monomer has one or two ethylenically unsaturated groups from the viewpoint of further improving the ejection stability, reducing the leakage of light, and further suppressing the decrease in the external quantum efficiency. It may contain a monomer having two or three ethylenically unsaturated groups. That is, the ethylenic monomer is at least one selected from the 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. May include a combination of. In the present embodiment, it is preferable that the ethylenically unsaturated monomer contains two or more kinds of monomers having two ethylenically unsaturated groups.

The ethylenically unsaturated monomer has a (meth) acryloyl group from the viewpoint of further improving ejection stability, reducing leakage light, and further suppressing a decrease in external quantum efficiency (meth). An acrylate monomer is preferably used. However, from the viewpoint of easily improving the discharge stability, it is preferable that the functional group containing the ethylenically unsaturated group is not a (meth) acrylamide group. That is, the monomer having an ethylenically unsaturated group preferably does not contain a monomer having a (meth) acrylamide group.

The functional group containing an ethylenically unsaturated group contained in the ethylenically unsaturated monomer is preferably not a vinyl ether group from the viewpoint of further improving the discharge stability. That is, the ethylenically unsaturated monomer preferably does not contain a monomer having a vinyl ether group. In particular, when the ink composition contains a compound having a carboxyl group, the reaction between the carboxyl group and the vinyl ether group increases the viscosity of the ink composition, making it difficult to obtain sufficient ejection stability.

Specific 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 ( Meta) acrylate, nonylphenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopenta Nyl (meth) 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, mono (2-acryloyloxyethyl) abraic acid, N- [2- (acryloyloxy) ethyl] phthalimide, N- [2- (acryloyloxy) ) Ethyl] Tetrahydrophthalimide 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. Didioldi (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 hydroxypivalic acid ester diacrylate, tris (2-hydroxyethyl) ) Two hydroxyl groups of a diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of di (meth) acrylate and neopentyl glycol in which two hydroxyl groups of isocyanurate are substituted with a (meth) acryloyloxy group. Di (meth) acrylate substituted with a (meth) acryloyloxy group, two hydroxyl groups of a diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A are substituted with a (meth) acryloyloxy group. Di (meth) acrylate, di (meth) acrylate in which 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 groups. Examples thereof include 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 a (meth) acryloyloxy group. Among these, dipropylene glycol di (meth) acrylate is preferably used.

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

When the ink composition contains a monofunctional monomer, the content of the monofunctional monomer is 45% by mass or more based on the mass of the non-volatile content of the ink composition from the viewpoint of compatibility with luminescent nanocrystal particles. It may be 55% by mass or more, and may be 65% by mass or more. The content of the monofunctional monomer may be 75% by mass or less, 65% by mass or less, and 55% by mass or less, based on the mass of the non-volatile content of the ink composition, from the viewpoint of improving the curability. It may be there.

When the ink composition contains a bifunctional monomer, the content of the bifunctional monomer is 45% by mass or more based on the mass of the non-volatile content of the ink composition from the viewpoint of compatibility with luminescent nanocrystal particles. It may be 55% by mass or more, and may be 65% by mass or more. Further, the content of the bifunctional monomer may be 100% by mass or less, 80% by mass or less, or 75% by mass, based on the mass of the non-volatile content of the ink composition from the viewpoint of improving the curability. It may be:

When the ink composition contains a trifunctional monomer, the content of the trifunctional monomer may be 10% by mass or more, and 20% by mass, based on the mass of the non-volatile content of the ink composition from the viewpoint of improving curability. % Or more, 25% by mass or more, and 30% by mass or more. Further, the content of the trifunctional monomer may be 40% by mass or less, 30% by mass or less, and 25% by mass, based on the mass of the non-volatile content of the ink composition from the viewpoint of ejection stability. It may be less than or equal to 20% by mass or less.

The ethylenically unsaturated monomer may have an ether bond in the molecule from the viewpoint of improving the affinity with the luminescent nanocrystal particles and further improving the luminescence characteristics (for example, the effect of suppressing the decrease in external quantum efficiency). .. For example, the ethylenically unsaturated monomer may be an alkylene oxide-modified (meth) acrylate.

The ethylenically unsaturated monomer may be alkali-insoluble from the viewpoint that a highly reliable color filter pixel portion can be easily obtained. In the present specification, the fact that the ethylenically unsaturated monomer is alkali-insoluble means that the amount of the ethylenically unsaturated monomer dissolved at 25 ° C. in a 1% by mass potassium hydroxide aqueous solution is based on the total mass of the ethylenically unsaturated monomer. It means that it is 30% by mass or less. The dissolved amount of the ethylenically unsaturated monomer is preferably 10% by mass or less, more preferably 3% by mass or less.

The content of the ethylenically unsaturated monomer is from the viewpoint that an appropriate viscosity can be easily obtained as an inkjet ink, 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 wear resistance, the ink composition may be 10% by mass or more, 15% by mass or more, or 20% by mass or more based on the mass of the non-volatile content of the ink composition. .. The content of the ethylenically unsaturated monomer is non-volatile in the ink composition from the viewpoint that an appropriate viscosity can be easily obtained as an inkjet ink and from the viewpoint of obtaining more excellent optical characteristics (for example, the effect of suppressing a decrease in external quantum efficiency). Based on the mass of the minute, it may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, and 50% by mass or less. May be.

[Photopolymerization initiator]
The photopolymerization initiator is preferably used from the viewpoints of storage stability of the ink composition containing luminescent nanocrystal particles (for example, quantum dots) and enabling curing at a low temperature which is not easily deteriorated by heating of the quantum dots. It is a photoradical polymerization initiator.

As the photoradical polymerization initiator, a molecular cleavage type or hydrogen abstraction type photoradical polymerization initiator is preferably used, and is selected from the group consisting of an acylphosphine oxide-based photopolymerization initiator and an alkylphenone-based photopolymerization initiator. At least one is more preferably used.

Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenyl (2,4,6-trimethylbenzoyl) ethyl phosphinate, and bis (2,6-dimethoxybenzoyl) -2. Examples thereof include 4,4-trimethylpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide.

Examples of the alkylphenone-based photopolymerization initiator include 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-dimethoxy-1,2-diphenylethane-1-one. , 2,2-Dimethoxy-2-phenylacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholino Examples thereof include propane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-one and the like.

Examples of the molecular cleavage type photoradical polymerization initiator other than the acylphosphine oxide-based photopolymerization initiator and the alkylphenone-based photopolymerization initiator include benzoins such as benzoin ethyl ether and benzoin isobutyl ether, and 2,4-diethylthioxanthone. , 2-Isopropylthioxanthone and the like, and the like.

Examples of the hydrogen abstraction type photoradical polymerization initiator include benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyl-diphenylsulfide and the like.

The molecular weight of the photopolymerization initiator is preferably 350 or less from the viewpoint of easily achieving both ejection stability and curability. From the same viewpoint, the molecular weight of the photopolymerization initiator may be 330 or less. The molecular weight of the photopolymerization initiator may be 150 or more from the viewpoint of easily achieving both ejection stability and curability.

Commercially available products can also be used as the photopolymerization initiator. Commercially available products include "Omnirad TPO-H", "Omnirad TPO-L", "Omnirad LR8953X", "Omnirad 651", "Omnirad 500", etc. manufactured by IGM resin ("Omnirad" is a registered trademark), BA. Examples thereof include "Lucirin TPO-G", "Irgacure 184", "Darocur 1173", "Darocur 4265" and the like ("Omnirad", "Lucirin", "Irgacure" and "Darocur" are registered trademarks).

The content of the photopolymerization initiator is 1.0 part by mass or more with respect to 100 parts by mass of the ethylenically unsaturated monomer from the viewpoint of being superior in the effect of suppressing the decrease in external quantum efficiency and the curability of the ink composition. It may be 5.5 parts by mass or more, or 10.5 parts by mass or more. The content of the photopolymerization initiator may be 35.0 parts by mass or less with respect to 100 parts by mass of the ethylenically unsaturated monomer from the viewpoint of the temporal stability of the pixel portion (cured product of the ink composition). It may be 25.0 parts by mass or less, or may be 15.5 parts by mass or less.

The content of the photopolymerization initiator is 0.1% by mass or more based on the mass of the non-volatile content of the ink composition from the viewpoint of being superior in the effect of suppressing the decrease in external quantum efficiency and the curability of the ink composition. It may be 0.5% by mass or more, 2.0% by mass or more, 3.5% by mass or more, and 4.5% by mass or more. The content of the photopolymerization initiator may be 10.0% by mass or less based on the mass of the non-volatile content of the ink composition from the viewpoint of the temporal stability of the pixel portion (cured product of the ink composition). It may be 7.0% by mass or less, 5.0% by mass or less, and 3.5% by mass or less. From these viewpoints, the content of the photopolymerization initiator may be, for example, 0.1 to 5.0% by mass, and 0.5 to 5.0% by mass, based on the mass of the non-volatile content of the ink composition. %, 0.5 to 3.5% by mass, and 0.5 to 2.0% by mass.

[Thiol compound]
The thiol compound has two or three primary mercapto groups in one molecule. The primary mercapto group means a mercapto group bonded to a primary carbon atom. That is, the thiol compound has _-CH2 -SH as a partial structure. The number of primary mercapto groups in the thiol compound is 2 or 3, preferably 3 from the viewpoint of ejection stability.

Since the thiol compound has a primary mercapto group, when the ink composition is cured by irradiation with an active energy ray (for example, ultraviolet rays), for example, a secondary or tertiary mercapto group (secondary or tertiary) is used. Compared to a thiol compound having a mercapto group bonded to a tertiary carbon atom), it can be cured with a smaller exposure amount (irradiation amount), it becomes easier to suppress a decrease in external quantum efficiency, and leakage light is reduced. It will be easier.

The thiol compound may further have a substituted or unsubstituted aliphatic hydrocarbon group in addition to the primary mercapto group, and may further have a carbonyloxy group (-COO-). The thiol compound is preferably a portion represented by the following formula (2) from the viewpoint of further improving the ejection stability, further reducing the leakage light, and further suppressing the decrease in the external quantum efficiency. Has a structure.

In the formula (2), n represents an integer of 0 or more, X represents a methylene group ( _-CH2- ) or a carbonyl group (-CO-), and * represents a bond. X is preferably a carbonyl group. n may be, for example, 1 to 10, and may be 1 to 5. When X is a carbonyl group, n is preferably 1 or 2, more preferably 2.

The thiol compound is preferably a compound represented by the following formula (3) from the viewpoint of further improving the ejection stability, reducing the leakage light, and further suppressing the decrease in the external quantum efficiency. be.

In formula (3), R represents an m-valent hydrocarbon group, m represents 2 or 3, and n and X are synonymous with n in formula (2). R is preferably an m-valent substituted or unsubstituted aliphatic hydrocarbon group. The carbon number of R may be 1 or more, 4 or more, 20 or less, or 10 or less. The substituted aliphatic hydrocarbon group may be one in which some hydrogen atoms of the aliphatic hydrocarbon group are substituted with hydroxyl groups, and some carbon atoms of the aliphatic hydrocarbon group are substituted with oxygen atoms. It may be a hydrocarbon. The substituted aliphatic hydrocarbon group may contain, for example, a (poly) oxyalkylene group. Here, the "(poly) oxyalkylene group" means at least one of an oxyalkylene group and a polyoxyalkylene group in which two or more alkylene groups are linked by an ether bond. The (poly) oxyalkylene group may be, for example, a (poly) oxyethylene group.

The viscosity of the thiol compound at 25 ° C. may be, for example, 20 mPa · s or more, 100 mPa · s or more, 200 mPa · s or less, or 170 Pa · s or less from the viewpoint of ejection stability during inkjet printing. You may. In the present specification, the viscosity of the thiol compound is, for example, the viscosity measured by an E-type viscometer.

Examples of the thiol compound having three primary mercapto groups include trimethylolpropane tris (3-mercaptopropionate). Examples of the thiol compound having two primary mercapto groups include tetraethylene glycol bis (3-mercaptopropionate). The thiol compound may be used alone or in combination of two or more.

Commercially available products can also be used as the thiol compound. Examples of commercially available thiol compounds having three primary mercapto groups include "TMMP" (trade name) and "PEPT" (trade name) manufactured by SC Organic Chemistry Co., Ltd. As a commercially available thiol compound having two primary mercapto groups, "EGMP-4" (trade name) manufactured by SC Organic Chemistry Co., Ltd. can be mentioned.

The content of the thiol compound is based on 100 parts by mass of the ethylenically unsaturated monomer from the viewpoint of further improving the ejection stability, reducing the leakage light, and further suppressing the decrease of the external quantum efficiency. , 1.0 part by mass or more, 8.0 parts by mass or more, or 14.0 parts by mass or more. The content of the thiol compound may be 32.5 parts by mass or less, even if it is 23.0 parts by mass or less, with respect to 100 parts by mass of the ethylenically unsaturated monomer from the viewpoint of further improving the discharge stability. It may be 15.0 parts by mass or less.

The content of the thiol compound is based on the mass of the non-volatile content of the ink composition from the viewpoint of further improving the ejection stability, reducing the leakage light, and further suppressing the decrease of the external quantum efficiency. , 0.5% by mass or more, 3.0% by mass or more, 5.0% by mass or more, and 7.5% by mass or more. The content of the thiol compound may be 10.0% by mass or less, or 7.5% by mass or less, based on the mass of the non-volatile content of the ink composition, from the viewpoint of further improving the ejection stability. , 5.0% by mass or less. From these viewpoints, the content of the thiol compound may be 0.5 to 3.0% by mass, and may be 0.5 to 5.0% by mass, based on the mass of the non-volatile content of the ink composition. It may be 0.5 to 7.5% by mass, and may be 0.5 to 10.0% by mass.

Although each component contained in the ink composition of the present embodiment has been described above, the ink composition of the present embodiment includes luminescent nanocrystal particles, an ethylenically unsaturated monomer, a photopolymerization initiator, a thiol compound and an organic substance. It may further contain other components other than the ligand. Examples of other components include light-scattering particles, polymer dispersants, sensitizers, solvents and the like.

[Light scattering particles]
The light-scattering particles are, for example, optically inert inorganic particles. The light-scattering particles can scatter the light from the light source irradiated to the color filter pixel portion.

Materials constituting the light-scattering particles include, for example, simple metal 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, Secondary bismuth carbonate, metal carbonates such as 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 may contain at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate and barium titanate from the viewpoint of being more excellent in reducing leakage light. It is more preferable to contain at least one selected from the group consisting of titanium oxide, zinc 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, particles having a spherical shape, a regular tetrahedron shape, etc.) to improve the uniformity, fluidity, and light scattering property of the ink composition. It is preferable in that it can be enhanced and excellent ejection stability can be obtained.

The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 0.05 μm or more from the viewpoint of being superior in the effect of reducing leakage light and further improving the light emission characteristics of the ink composition. , 0.2 μm or more, or 0.3 μm or more. The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 1.0 μm or less, 0.6 μm or less, or 0, from the viewpoint of excellent ejection stability. It may be 0.4 μm 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 50 nm or more, and may be 1000 nm or less. 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. Further, the average particle diameter (volume average diameter) of the light-scattering particles to be 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.

The content of the light-scattering particles is 0.1% by mass or more based on the mass of the non-volatile content of the ink composition from the viewpoint of being superior in the effect of reducing leakage light and further improving the light emission characteristics of the ink composition. It may be 1% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, or 12% by mass or more. May be good. The content of the light-scattering particles may be 60% by mass or less based on the mass of the non-volatile content of the ink composition from the viewpoint of being superior in the effect of reducing leakage light and further improving the emission characteristics of the ink composition. , 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less. , 15% by mass or less. In the present embodiment, since the ink composition contains a polymer dispersant, the light-scattering particles can be satisfactorily dispersed even when the content of the light-scattering particles is within the above range.

The mass ratio of the content of the light-scattering particles to the content of the light-emitting nanocrystal particles (light-scattering particles / light-emitting nanocrystal particles) is excellent in the effect of reducing leakage light, and further improves the light emission characteristics of the ink composition. From the viewpoint of making the particles, it may be 0.1 or more, 0.2 or more, or 0.5 or more. The mass ratio (light-scattering particles / light-emitting nanocrystal particles) is 5.0 or less from the viewpoint of further improving the light-emitting characteristics of the ink composition and excellent continuous ejection property (ejection stability) during inkjet printing. It may be 2.0 or less, or 1.5 or less.

The reduction of light leakage due to light-scattering particles (light that leaks from the pixel portion without being absorbed by the luminescent nanocrystal particles) is considered to be due to the following mechanism. That is, in the absence of light-scattering particles, the backlight light only travels almost straight through the pixel portion and is considered to have little chance of being absorbed by the luminescent nanocrystal particles. On the other hand, if the light-scattering particles are present in the same pixel portion as the luminescent nanocrystal particles, the backlight light is scattered in all directions in the pixel portion, and the luminescent nanocrystal particles can receive the light. Even if the same backlight is used, it is considered that the amount of light absorption in the pixel portion is increased and the light emission intensity of the luminescent nanocrystal particles is further improved. As a result, it is considered that such a mechanism can prevent leakage light and further improve the light emission characteristics of the ink composition.

[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, and has a function of dispersing the 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 bound to the surface of the light-scattering particles and adsorbed to the light-scattering particles, but is bound to the surface of the luminescent nanoparticles and adsorbed to the luminescent nanoparticles. It may be free in the ink composition.

By the way, one of the causes of deterioration of ejection stability when forming a color filter pixel portion by an inkjet method using a conventional ink composition is considered to be aggregation of luminescent nanocrystal particles and light scattering particles. .. Therefore, it is conceivable to improve the ejection stability by refining the luminescent nanocrystal particles and the light-scattering particles, reducing the content of the luminescent nanocrystal particles and the light-scattering particles, and the like. In this case, it is difficult to obtain the effect of suppressing the decrease in external quantum efficiency, and it is difficult to achieve both ejection stability and suppression of decrease in external quantum efficiency at a high level. On the other hand, according to the ink composition further containing the polymer dispersant, excellent ejection stability and suppression of reduction in external quantum efficiency can be achieved at a high level. The reason why such an effect is obtained is not clear, but it is because the polymer dispersant remarkably suppresses the aggregation of luminescent nanocrystal particles and light scattering particles (particularly, light scattering particles). It is inferred that.

Examples of the functional group having an affinity for 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 by a base such as an amine or a hydroxide ion, and the basic functional group is neutralized by an acid such as an organic acid or an inorganic acid. May be.

The acidic functional groups include 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), and the like.

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.

Nonionic functional groups include hydroxy group, ether group, thioether group, sulfinyl group (-SO-), sulfonyl group ( _-SO2- ), carbonyl group, formyl group, ester group, carbonate ester group, amide group, and the like. Examples thereof include a carbamoyl group, a ureido group, a thioamide group, a thioureido group, a sulfamoyl group, a cyano group, an alkenyl group, an alkynyl group, a phosphine oxide group and a phosphine sulfide group.

Acidic functionality from the viewpoint of dispersion stability of light-scattering particles, less likely to cause the side effect of sedimentation of luminescent nanocrystal particles, ease of synthesis of polymer dispersant, and stability of functional groups. As the group, a carboxyl group, a sulfo group, a phosphonic acid group and a phosphoric acid group are preferably used, and as a basic functional group, an amino group is preferably used. Among these, a carboxyl group, a phosphonic acid group and an amino group are more preferably used, and most preferably an amino group is used.

Polymer dispersants with acidic functional groups have an acid value. The acid value of the polymer dispersant having an acidic functional group is preferably 1 to 150 mgKOH / g. When the acid value is 1 mgKOH / g or more, sufficient dispersibility of the light-scattering particles can be easily obtained, and when the acid value is 150 mgKOH / g or less, the storage stability of the pixel portion (cured product of the ink composition) is easy to obtain. Is hard to decrease.

For the acid value of the polymer dispersant, prepare a sample solution prepared by dissolving the polymer dispersant pg in 50 mL of a mixed solution of toluene and ethanol in a volume ratio of 1: 1 and 1 mL of a phenolphthaline test solution. Titrate with a 1 mol / L ethanol potassium hydroxide solution (7.0 g of potassium hydroxide dissolved in 5.0 mL of distilled water and adjusted to 1000 mL by adding 95 vol% ethanol) until the sample solution turns pink. I do. Then, the acid value can be calculated by the following formula.
Acid value = q × r × 5.611 / p
In the formula, q indicates the titration amount (mL) of the 0.1 mol / L ethanol potassium hydroxide solution required for titration, and r indicates the titer of the 0.1 mol / L ethanol potassium hydroxide solution required for titration. Shown, p indicates the mass (g) of the polymer dispersant.

Polymer dispersants with basic functional groups have an amine value. The amine value of the polymer dispersant having a basic functional group is preferably 1 to 200 mgKOH / g. When the amine value is 1 mgKOH / g or more, sufficient dispersibility of the light-scattering particles can be easily obtained, and when the amine value is 200 mgKOH / g or less, the storage stability of the pixel portion (cured product of the ink composition) is easy to obtain. Is hard to decrease.

For the amine value of the polymer dispersant, prepare a sample solution prepared by dissolving xg of the polymer dispersant in 50 ml of a mixed solution of toluene and ethanol mixed at a volume ratio of 1: 1 and 1 ml of a bromophenol blue test solution. Titrate with 5 mol / L toluene until the sample solution turns green. Then, the amine value can be calculated by the following formula.
Amine value = y / x × 28.05
In the formula, y indicates the titration amount (ml) of 0.5 mol / L hydrochloric acid required for titration, and x indicates the mass (g) of the polymer dispersant.

The polymer dispersant may be a polymer (homopolymer) of a single monomer, or may be a copolymer (copolymer) of a plurality of types of monomers. Further, the polymer dispersant may be any of a random copolymer, a block copolymer or 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, polyamine such as polyethyleneimine and polyallylamine, epoxy resin, polyimide and the like. 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 Azispar PB series, BYK's DISPERBYK series, BYK-series, and BASF's Efka. Series etc. can be used.

Examples of commercially available products include "DISPERBYK-130", "DISPERBYK-161", "DISPERBYK-162", "DISPERBYK-163", "DISPERBYK-164", "DISPERBYK-166", and "DISPERBYK-" manufactured by Big Chemie. 167 ”,“ DISPERBYK-168 ”,“ DISPERBYK-170 ”,“ DISPERBYK-171 ”,“ DISPERBYK-174 ”,“ DISPERBYK-180 ”,“ DISPERBYK-182 ”,“ DISPERBYK-183 ”,“ DISPERBYK-184 ” , "DISPERBYK-185", "DISPERBYK-2000", "DISPERBYK-2001", "DISPERBYK-2008", "DISPERBYK-2009", "DISPERBYK-2020", "DISPERBYK-2022", "DISPERBYK-2025" DISPERBYK-2050 "," DISPERBYK-2070 "," DISPERBYK-2096 "," DISPERBYK-2150 "," DISPERBYK-2155 "," DISPERBYK-2163 "," DISPERBYK-2164 "," BYK-LPN21116 "and" BYK-LPN21116 " LPN6919 ”; BASF's“ EFKA4010 ”,“ EFKA4015 ”,“ EFKA4046 ”,“ EFKA4047 ”,“ EFKA4061 ”,“ EFKA4080 ”,“ EFKA4300 ”,“ EFKA4310 ”,“ EFKA4320 ”,“ EFKA4320 ” , "EFKA4560", "EFKA4585", "EFKA5207", "EFKA1501", "EFKA1502", "EFKA1503" and "EFKA PX-4701"; , "Solspers 13650", "Solspers 13940", "Solspers 11200", "Solspers 13940", "Solspers 16000", "Solspers 17000", "Solspers 18000", "Solspers 20000", "Solspers 21000", "Solspers 24000" , "Sol Sparse 26000", "Sol Sparse 27000", "Sol Sparse 28000", "Sol Sparse 32000" , "Sol Sparse 32500", "Sol Sparse 32550", "Sol Spur 32600", "Sol Sparse 33000", "Sol Sparse 34750", "Sol Sparse 35100", "Sol Sparse 35200", "Sol Sparse 36000", "Sol Sparse 37500", "Sol Sparse 38500" , "Solspur 39000", "Solspers 41000", "Solspers 54000", "Solspers 71000" and "Solspers 76500"; "PN411" and "PA111"; Evonik's "TEGO Dispers 650", "TEGO Dispers 660C", "TEGO Dispers 662C", "TEGO Dispers 670", "TEGO Dispers 685", "TEGO Dispers 685", "TEGO Dis ";" Disparon DA-703-50 "," DA-705 "," DA-725 ", etc. manufactured by Kusumoto Kasei can be used.

As the polymer dispersant, in addition to the commercially available products as described above, a cationic monomer containing a basic group and / or an anionic monomer having an acidic group, a monomer having a hydrophobic group, and other monomers as necessary. A product synthesized by copolymerizing with (a nonionic monomer, a monomer having a hydrophilic group, etc.) can be used. For details of the cationic monomer, the anionic monomer, the monomer having a hydrophobic group and other monomers, the monomers described in paragraphs 0034 to 0036 of JP-A-2004-250502 can be mentioned.

Further, for example, a compound obtained by reacting a polyester compound with a polyalkyleneimine described in JP-A-54-37082, JP-A-61-174939, etc., and a polyallylamine described in JP-A-9-169821. A compound in which the amino group of the side chain is modified with polyester, a graft polymer containing the polyester-type macromonomer described in JP-A-9-171253 as a copolymerization component, and the addition of a polyester polyol described in JP-A-60-166318. Polyurethane and the like are preferably mentioned.

The weight average molecular weight of the polymer dispersant may be 750 or more, and 1000 or more, from the viewpoint of being able to disperse light-scattering particles satisfactorily and further improving the effect of suppressing a decrease in external quantum efficiency. It may be 2000 or more, or 3000 or more. The weight average molecular weight of the polymer dispersant can satisfactorily disperse light-scattering particles, further improve the effect of suppressing a decrease in external quantum efficiency, and can eject the viscosity of inkjet ink in a stable manner. From the viewpoint of obtaining a viscosity suitable for the above, it may be 100,000 or less, 50,000 or less, or 30,000 or less.

From the viewpoint of the dispersibility of the light-scattering particles, the content of the polymer dispersant may be 0.5 parts by mass or more with respect to 100 parts by mass of the light-scattering particles, and may be 2 parts by mass or more. It may be 5 parts by mass or more. The content of the polymer dispersion may be 50 parts by mass or less and 30 parts by mass or less with respect to 100 parts by mass of the light-scattering particles from the viewpoint of moist heat stability of the pixel portion (cured product of the ink composition). It may be 10 parts by mass or less.

[Sensitizer]
As the sensitizer, for example, amines can be used. Examples of the sensitizer include trimethylamine, methyldimethylamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, N-dimethylbenzylamine, 4, Examples thereof include 4'-bis (diethylamino) benzophenone.

[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 is preferably 180 ° C. or higher from the viewpoint of continuous ejection stability of the inkjet ink. Further, since it is necessary to remove the solvent from the ink composition before curing the ink composition at the time of forming the pixel portion, the boiling point of the solvent is preferably 300 ° C. or lower from the viewpoint of easy removal of the solvent.

In the ink composition of the present embodiment, since the ethylenically unsaturated monomer 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.

The viscosity of the ink composition at 40 ° C. may be, for example, 2 mPa · s or more, 5 mPa · s or more, or 7 mPa · s or more from the viewpoint of ejection stability during inkjet printing. good. The viscosity of the ink composition at 40 ° C. may be 20 mPa · s or less, 15 mPa · s or less, or 12 mPa · s or less. The viscosity of the ink composition at 40 ° C. 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 It may be 20 mPa · s, 7 to 15 mPa · s, or 7 to 12 mPa · s. In the present specification, the viscosity of the ink composition is, for example, the viscosity measured by an E-type viscometer.

The viscosity of the ink composition at 23 ° C. may be, for example, 5 mPa · s or more, 10 mPa · s or more, or 15 mPa · s or more from the viewpoint of ejection stability during inkjet printing. good. The viscosity of the ink composition at 23 ° C. may be 40 mPa · s or less, 35 mPa · s or less, 30 mPa · s or less, or 25 mPa · s or less. The viscosity of the ink composition at 23 ° C. may be, for example, 5 to 40 mPa · s, 10 to 35 mPa · s, 10 to 30 mPa · s, 15 to 30 mPa · s or 15 to 25 mPa · s.

When the viscosity of the ink composition at 40 ° C. is 2 mPa · s or more, or the viscosity of the ink composition at 23 ° C. is 5 mPa · s or more, the meniscus shape of the inkjet ink at the tip of the ink ejection hole of the ejection head. Is stable, so that the ejection control of the inkjet ink (for example, the control of the ejection amount and the ejection timing) becomes easy. On the other hand, when the viscosity of the ink composition at 40 ° C. is 20 mPa · s or less, or the viscosity of the ink composition at 40 ° C. is 40 mPa · s or less, the inkjet ink is smoothly ejected from the ink ejection holes. Can be done.

The surface tension of the ink composition is preferably a surface tension suitable for the inkjet method, specifically, is 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, 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 meniscus shape at the tip of the ink ejection hole is stable, so that ejection control of the ink composition (for example, control of ejection amount and ejection timing) becomes easy. On the other hand, when the surface tension is 20 mN / m or more, the occurrence of flight bending can be suppressed. That is, a pixel portion may not be landed accurately on the pixel portion forming region to be landed, and the ink composition may be insufficiently filled, 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.

When the ink composition of the present embodiment is used as an ink composition for an inkjet method, it is preferably applied to a piezojet type inkjet recording device having 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, deterioration of the luminescent nanocrystal particles is unlikely to occur, and the color filter pixel portion (light conversion layer) has the expected emission characteristics. Is easier to obtain.

Although one embodiment of the ink composition for a color filter has been described above, the ink composition of the above-described embodiment can be used, for example, by a photolithography method in addition to the inkjet method.

When the ink composition is used in a photography method, the ink composition is first applied onto a substrate, and when the ink composition contains a solvent, the ink composition is further dried to form a coating film. The coating film thus obtained is soluble in an alkaline developer and is patterned by being treated with an alkaline developer. At this time, since the alkaline developer is mostly an aqueous solution from the viewpoint of ease of waste liquid treatment of the developer, the coating film of the ink composition is treated with the aqueous solution. On the other hand, in the case of an ink composition using luminescent nanocrystal particles (quantum dots or the like), the luminescent nanocrystal particles are unstable with respect to water, and the luminescence (for example, fluorescence) is impaired by water. Therefore, in this embodiment, an inkjet method that does not need to be treated with an alkaline developer (aqueous solution) is preferable.

Even when the coating film of the ink composition is not treated with an alkaline developer, if the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere, and time elapses. As a result, the luminescence (for example, fluorescence) of the luminescent nanocrystal particles (quantum dots, etc.) is impaired. From this point of view, 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 ethylenically unsaturated monomer as the ethylenically unsaturated monomer. The fact that the coating film of the ink composition is alkaline 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 dissolved amount of the coating film of the ink composition 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 after the ink composition is applied onto the substrate, it is dried at 80 ° C. for 3 minutes when it contains a solvent. It can be confirmed by measuring the above-mentioned dissolution amount of the obtained coating film having a thickness of 1 μm.

<Manufacturing method of ink composition>
Next, a method for producing the ink composition of the above-described embodiment will be described. The method for producing an ink composition includes at least a step of mixing luminescent nanocrystal particles, an ethylenically unsaturated monomer, a photopolymerization initiator, and a thiol compound. For example, an ink composition can be obtained by mixing the constituent components of the above-mentioned ink composition and performing a dispersion treatment.

When the ink composition contains light-scattering particles, the method for producing the ink composition includes, for example, a step of preparing a luminescent nanocrystal particle dispersion containing luminescent nanocrystal particles and an ethylenically unsaturated monomer. , A step of preparing a light-scattering particle dispersion containing light-scattering particles and an ethylenically unsaturated monomer, and a step of mixing a light-emitting nanocrystalline particle dispersion and a light-scattering particle dispersion. Be prepared.

In the method for producing an ink composition, the thiol compound may be blended so as to be contained in an ink composition obtained by mixing a luminescent nanocrystal particle dispersion and a light scattering particle dispersion. Therefore, the thiol compound may be contained in one or both of the luminescent nanocrystal particle dispersion and the light-scattering particle dispersion, and the luminescent nanocrystal particle dispersion, the light-scattering particle dispersion, and the thiol compound may be contained. When mixed, the thiol compound may not be contained in either the luminescent nanocrystalline particle dispersion or the light scattering particle dispersion.

In the method for producing an ink composition, the photopolymerization initiator may be blended so as to be contained in the ink composition obtained by mixing the luminescent nanocrystal particle dispersion and the light scattering particle dispersion. Therefore, the photopolymerization initiator may be contained in one or both of the luminescent nanocrystal particle dispersion and the light-scattering particle dispersion, and the luminescent nanocrystal particle dispersion, the light-scattering particle dispersion, and photopolymerization may be contained. When mixed with the initiator, the photopolymerization initiator may not be contained in either the luminescent nanocrystalline particle dispersion or the light scattering particle dispersion. When the above-mentioned monomer having one or two ethylenically unsaturated groups and the monomer having two or three ethylenically unsaturated groups are used as the ethylenically unsaturated monomer, the luminescent nanocrystal particle dispersion is these. A luminescent nanocrystal particle dispersion and a light scattering particle dispersion may be prepared so that one of the monomers is contained and the light scattering particle dispersion contains the other monomer.

According to this production method, since the luminescent nanocrystal particles and the light scattering particles are dispersed in the ethylenically unsaturated monomer before being mixed with each other, the luminescent nanocrystal particles and the light scattering particles are sufficiently dispersed. Therefore, excellent ejection stability can be easily obtained, and a decrease in external quantum efficiency can be easily suppressed.

In the step of preparing the luminescent nanocrystal particle dispersion, the luminescent nanocrystal particle dispersion may be prepared by mixing the luminescent nanocrystal particles and the ethylenically unsaturated monomer and performing a dispersion treatment. As the luminescent nanocrystal particles, luminescent nanocrystal particles having an organic ligand on the surface thereof may be used. That is, the luminescent nanocrystal particle dispersion may further contain an organic ligand. The mixing and dispersion treatment may be performed 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 good and the average particle size of the luminescent nanocrystal particles can be easily adjusted to a desired range.

In the step of preparing the light-scattering particle dispersion, the light-scattering particle dispersion may be prepared by mixing the light-scattering particles and the ethylenically unsaturated monomer and performing a dispersion treatment. The mixing and dispersion treatment may be carried out using the same apparatus as in the step of preparing the luminescent nanocrystal particles. 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.

In the step of preparing the light-scattering particle dispersion, the polymer dispersant may be further mixed. That is, the light-scattering particle dispersion may further contain a polymer dispersant. 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 can be obtained more easily, and a decrease in external quantum efficiency can be further suppressed.

In this production method, components other than luminescent nanocrystalline particles, thiol compounds, light scattering particles, ethylenically unsaturated monomers, photopolymerization initiators, organic ligands and polymer dispersants (eg, sensitizers, solvents) Etc.) 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.

<Optical conversion layer and color filter>
Next, the details of the light conversion layer and the color filter using the ink composition 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 each include a cured product of the ink composition of the above-described embodiment. The cured product contains luminescent nanocrystal particles, light-scattering particles, and a cured component. The curing component is a cured product (polymerization reaction product) of an ethylenically unsaturated monomer and a thiol compound, and specifically, a cured product obtained by polymerizing an ethylenically unsaturated monomer and a thiol compound. 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. include. Similarly, the second pixel portion 10b includes the second curing component 13b and 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 a emission peak wavelength in the range of 605 to 665 nm. That is, the first pixel portion 10a may be paraphrased 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 a emission peak wavelength in the range of 500 to 560 nm. That is, the second pixel portion 10b may be paraphrased as a green pixel portion for converting blue light into green light.

The content of the luminescent nanocrystal particles in the pixel portion containing the cured product of the ink composition is preferably 5% by mass or more based on the total mass of the cured product of the ink composition from the viewpoint of obtaining excellent emission intensity. Is. From the same viewpoint, the content of the luminescent nanocrystal particles may be 10% by mass or more, 15% by mass or more, or 20% by mass based on the total mass of the cured product of the ink composition. It may be% or more. The content of the luminescent nanocrystal particles is preferably 50% by mass or less based on the total mass of the cured product of the ink composition from the viewpoint of excellent reliability of the pixel portion and excellent luminescence intensity. .. From the same viewpoint, the content of the luminescent nanocrystal particles may be 40% by mass or less, 35% by mass or less, or 30% by mass, based on the total mass of the cured product of the ink composition. It may be less than or equal to%.

The content of the light-scattering particles in the pixel portion containing the cured product of the ink composition is 0.1 mass based on the total mass of the cured product of the ink composition from the viewpoint of excellent in the effect of reducing leakage light and the light emission characteristics. % Or more, 1% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, 12% by mass. It may be the above. The content of the light-scattering particles is 60% by mass or less based on the total mass of the cured product of the ink composition from the viewpoint of excellent light leakage reduction effect and light emission characteristics and excellent reliability of the pixel portion. It may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less. It may be 15% by mass or less.

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. Therefore, the third pixel unit 10c functions as a blue pixel unit when a light source that emits light having a wavelength in the range of 420 to 480 nm is used. The third pixel portion 10c contains, for example, a cured product of the composition containing the ethylenically unsaturated monomer described above. The cured product contains a third cured component 13c. The third curing component 13c is a cured product (polymerization reaction product) of the ethylenically unsaturated monomer and the thiol compound, and specifically, is a cured product obtained by polymerizing the ethylenically unsaturated monomer and the thiol compound. That is, the third pixel portion 10c contains the third curing component 13c. When the third pixel portion 10c contains the above-mentioned cured product, the composition containing the ethylenically unsaturated monomer is described above as long as the transmittance for light having a wavelength in the range of 420 to 480 nm is 30% or more. Among the components contained in the ink composition, components other than the ethylenically unsaturated monomer may be further contained. The transmittance of the third pixel unit 10c can be measured by a microspectroscopy device.

The thickness of the pixel portion (first pixel portion 10a, second pixel portion 10b, and third pixel portion 10c) may be, for example, 1 μm or more, 2 μm or more, or 3 μm or more. You may. The thickness of the pixel portion (first pixel portion 10a, second pixel portion 10b, and third pixel portion 10c) may be, for example, 30 μm or less, 20 μm or less, or 15 μm or less. You may.

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 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, Pylex (registered trademark) glass, a synthetic quartz plate, a transparent resin film, an optical resin film, 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 thermal expansion rate 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 suitably used when a light source that emits light having a wavelength in the range of 420 to 480 nm is used.

In the color filter 100, for example, after the light-shielding portion 20 is formed in a pattern on the base material 40, the ink composition of the above-described embodiment is formed in the pixel portion-forming region partitioned by the light-shielding portion 20 on the base material 40. Inkjet ink) can be selectively adhered by an inkjet method, and the ink composition can be cured by irradiation with active energy rays.

The method of forming the light-shielding portion 20 is to form a metal thin film such as chromium or a thin film of a resin composition containing light-shielding particles in a region serving as a boundary between a plurality of pixel portions on one surface side of the base material 40. However, a method of patterning this thin film and the like can be mentioned. The metal thin film can be formed by, for example, a sputtering method, a vacuum vapor deposition method, or the like, and the thin film of the resin composition containing the light-shielding particles can be formed, for example, by a method such as coating or printing. Examples of the method for patterning include a photolithography method and the like.

Examples of the inkjet method include a bubble jet (registered trademark) method using an electric heat converter as an energy generating element, a piezojet method using a piezoelectric element, and the like.

When the ink composition 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. 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 may be 4000 mJ / cm ² or less.

The drying temperature for volatilizing the solvent may be, for example, 50 ° C. or higher, and may be 150 ° C. or lower. The drying time may be, for example, 3 minutes or more and 30 minutes or less.

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 optical conversion layer is a pixel portion containing a cured product of an ink composition containing blue-emitting nanocrystal particles in place of the third pixel portion 10c or in addition to the third pixel portion 10c ( It may be provided with a blue pixel portion). Further, the light conversion layer may include a pixel portion (for example, a yellow pixel portion) containing a cured product of an ink composition containing nanocrystal particles that emit light of a color other than red, green, and blue. In these cases, it is preferable that each of the luminescent nanocrystal particles contained in each pixel portion of the optical 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 parental ink 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 elution 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 the manufacture of the color filter and the optical conversion layer, the pixel portion may be formed by a photolithography method instead of the inkjet method. In this case, first, the ink composition is coated on the base material in a layered manner to form an ink composition layer. Next, the ink composition layer is exposed in a pattern and then developed using a developing solution. In this way, a pixel portion made of a cured product of the ink composition is formed. Since the developer is usually alkaline, an alkali-soluble material is used as the material of the ink composition. However, in terms of material usage efficiency, the inkjet method is superior to the photolithography method. This is because, in principle, the photolithography method removes about two-thirds or more of the material, and the material is wasted. Therefore, in the present embodiment, it is preferable to use an inkjet ink and form a pixel portion by an inkjet method.

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. For example, when a pixel portion containing luminescent nanocrystal particles that absorb and emit blue light is used as the pixel portion of the liquid crystal display element, the light from the light source is blue light or semi-white light having a peak at 450 nm. However, if the concentration of the luminescent nanocrystal particles in the pixel portion is not sufficient, the light from the light source passes through the light conversion layer when the liquid crystal display element is driven. The transmitted light (blue light, leaked light) from this light source and the light emitted by the luminescent nanocrystal particles are mixed. From the viewpoint of preventing deterioration of color reproducibility due to the occurrence of such color mixing, a pigment may be contained in the pixel portion of the optical conversion layer. In order to contain the pigment in the pixel portion, the pigment may be contained in the ink composition.

Further, 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, one or two types of pixel portions are formed by luminescent nanocrystal particles. It may be a pixel portion containing a coloring material without containing the above. As the color material that can be used here, a known color material can be used. For example, examples of the coloring material used for the red pixel portion (R) include diketopyrrolopyrrole pigments and / or anionic red organic dyes. Examples of the coloring material used for the green pixel portion (G) include at least one selected from the group consisting of a halogenated copper phthalocyanine pigment, a phthalocyanine-based green dye, 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 phthalosine pigment and / or a cationic blue organic dye. The amount of these coloring materials used is 1 to 5 mass 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 optical conversion layer. % Is preferable.

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 nitrogen gas. As for titanium oxide, one which was heated at 120 ° C. for 2 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 thiol compound>
The following thiol compounds 1 to 6 were prepared as thiol compounds.
(Thiol compound 1)
Trimethylolpropane Tris (3-mercaptopropionate) (manufactured by SC Organic Chemistry Co., Ltd., trade name: TMMP)
(Thiol compound 2)
Tetraethylene glycol bis (3-mercaptopropionate) (manufactured by SC Organic Chemistry Co., Ltd., trade name: EGMP-4)
(Thiol compound 3)
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by SC Organic Chemistry Co., Ltd., trade name: PEMP)
(Thioll compound 4)
Pentaerythritol Tetrakis (3-mercaptobutyrate) (manufactured by Showa Denko KK, product name: Karenz MT-PE1)
(Thiol compound 5)
1,3,5-Tris (3-mercaptobutylyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -Torion (manufactured by Showa Denko KK, trade name: Calends) MT NR1)
(Thioll compound 6)
1,4-Bis (3-mercaptobutylyloxy) butane (manufactured by Showa Denko KK, trade name: Karenz MTBD-1)

<Preparation of photopolymerization initiator>
The following photopolymerization initiator 1 was prepared as the photopolymerization initiator.
(Photopolymerization Initiator 1)
2-Hydroxy-2-methyl-1-phenylpropane-1-one (manufactured by BASF, trade name: Darocur 1173 (hereinafter, also simply referred to as "1173"))

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

[Synthesis of shell (ZnSeS / ZnS shell) of green luminescent nanocrystal particles]
After adding 2.5 g of the hexane dispersion of the InP nanocrystal particles (InP core) obtained above to the reaction flask, 0.7 g of oleic acid was added to the reaction flask at room temperature, and the temperature was raised to 80 ° C. rice field. Then, 14 mg of diethylzinc, 8 mg of bis (trimethylsilyl) selenide and 7 mg of hexamethyldisirateyan (ZnSeS precursor solution) dissolved in 1 ml of ODE were added dropwise to the reaction mixture to obtain a thickness of 0.5 monolayer. A ZnSeS shell was formed.

After dropping the ZnSeS precursor solution, the reaction temperature was maintained at 80 ° C. for 10 minutes. The temperature was then raised to 140 ° C. and held for 30 minutes. Next, a ZnS precursor solution obtained by dissolving 69 mg of diethylzinc and 66 mg of hexamethyldisiratean in 2 ml of ODE was added dropwise to this reaction mixture to form a ZnS shell having a thickness of 2 monolayers. .. After 10 minutes of dropping the ZnS precursor solution, the reaction was stopped by removing the heater. Next, the reaction mixture was cooled to room temperature, and the obtained white precipitate was removed by centrifugation, so that a transparent nanocrystal particle dispersion (ODE dispersion) in which green-emitting InP / ZnSeS / ZnS nanocrystal particles were dispersed was dispersed. ) Was obtained.

[Synthesis of organic ligands for InP / ZnSeS / ZnS nanocrystal particles]
After putting mPEG5-NH2 (manufactured by Sigma-Aldrich) into a flask, succinic anhydride (manufactured by Sigma-Aldrich) in an equimolar amount with mPEG5-NH2 was added thereto while stirring in a nitrogen gas environment. The internal temperature of the flask was raised to 80 ° C. and stirred for 8 hours to obtain a ligand represented by the following formula (1A).

[Preparation of green luminescent InP / ZnSeS / ZnS nanocrystal particle dispersion by ligand exchange]
30 mg of the organic ligand was added to 1 ml of the ODE dispersion of the nanocrystal particles obtained above. Then, the ligand was exchanged by heating at 90 ° C. for 5 hours. As the ligand exchange progressed, aggregation of nanocrystal particles was observed. After the ligand exchange was completed, the supernatant was tilted, 3 ml of ethanol was added to the nanocrystal particles, and the nanoparticles were treated with ultrasonic waves to redisperse. 10 ml of n-hexane was added to 3 mL of the ethanol dispersion of the obtained nanocrystal particles. Subsequently, centrifugation was performed to precipitate the nanocrystal particles, and then the supernatant was tilted and dried under vacuum to obtain nanocrystal particles (InP / ZnSeS / ZnS nanocrystal particles modified with the above organic ligand). The content of the organic ligand in the total amount of the nanocrystal particles modified with the organic ligand was 35% by mass. The obtained nanocrystal particles (InP / ZnSeS / ZnS nanocrystal particles modified with the above organic ligand) were subjected to 1,6-hexanediol dimethacrylate (16-hexanediol dimethacrylate) so that the content in the dispersion was 46.3% by mass. A green luminescent nanocrystal particle dispersion 1 was obtained by dispersing the particles in Shin-Nakamura Chemical Industry Co., Ltd., trade name: NK ester HD-N, hereinafter also referred to as "HDDMA"). The content of HDDMA in the dispersion was 53.7% by mass.

<Preparation of light-scattering particle dispersion>
Titanium oxide (trade name: CR-60-2, manufactured by Ishihara Sangyo Co., Ltd., average particle size (volume average size): 210 nm) was added to 33.0 g in a container filled with argon gas, and a polymer dispersant ( Product name: Azispar PB-821, manufactured by Ajinomoto Fine Techno Co., Ltd. 1.0 g, and dipropylene glycol diacrylate (manufactured by MIWON, product name: MIRAMER M222, hereinafter also referred to as "DPGDA") 18.2 g. And 1,6-hexanediol dimethacrylate (manufactured by MIWON, trade name: MIRAMER M201, hereinafter also referred to as "HDDMA") are mixed with 7.8 g, and then zirconia beads (diameter: 1. 25 mm) was added and shaken for 2 hours using a paint conditioner to disperse the mixture, and the zirconia beads were removed with a polyester mesh filter to disperse the light-scattering particle dispersion 1 (titanium oxide content: 55 mass). %) Was obtained. The content of DPGDA in the dispersion was 30.3% by mass, and the content of HDDMA was 13.0%.

<Example 1>
[Preparation of green ink composition (inkjet ink)]
6.2 g of green luminescent nanocrystalline particle dispersion 1, 0.5 g of thiol compound 1, 3.1 g of light-scattering particle dispersion 1, and 0.2 g of photopolymerization initiator 1 are argon. After uniform mixing in a gas-filled container, the mixture was filtered in a glove box with a filter having a pore size of 5 μm. Further, it was introduced into a container containing a filtrate obtained by obtaining argon gas, and the inside of the container was saturated with argon gas. Then, the pressure was reduced to remove the argon gas to obtain an ink composition. The content of the photopolymerization initiator 1 was 2.0% by mass based on the total mass of the ink composition (mass of the non-volatile content of the ink composition).

<Example 2 and Comparative Examples 1 to 4>
The ink compositions of Examples 2 and Comparative Examples 1 to 4 were prepared in the same manner as in Example 1 except that thiol compounds 2 to 6 were used instead of the thiol compound 1.

<Example 3>
[Preparation of green ink composition (inkjet ink)]
6.0 g of green luminescent nanocrystalline particle dispersion 1, 0.5 g of thiol compound 1, 3.0 g of light-scattering particle dispersion 1, 0.5 g of photopolymerization initiator 1 and argon. After uniform mixing in a gas-filled container, the mixture was filtered in a glove box with a filter having a pore size of 5 μm. Further, it was introduced into a container containing a filtrate obtained by obtaining argon gas, and the inside of the container was saturated with argon gas. Then, the pressure was reduced to remove the argon gas to obtain an ink composition. The content of the photopolymerization initiator 1 was 5.0% by mass based on the total mass of the ink composition (mass of the non-volatile content of the ink composition).

<Evaluation>
[Discharge stability evaluation]
After preparation, the ink composition was stored at 23 ° C. and 50% RH for 1 week. The ink composition after storage was subjected to a ejection test using an inkjet printer (manufactured by Fujifilm Dimatics, trade name "DMP-2831"). In the ejection test, the temperature of the inkjet head was heated to 40 ° C., and the ink composition was continuously ejected for 20 minutes using five nozzles. Five nozzles are formed in the head portion of the inkjet printer for ejecting ink, and the amount of the ink composition used per nozzle per ejection is 10 pL. The ejection stability of the ink compositions of Examples 1 and 2 and Comparative Examples 1 to 3 was evaluated according to the following criteria. The results are shown in Tables 1 and 2.
A: Continuous discharge is possible (3 or more nozzles out of 5 nozzles can continuously discharge)
B: Continuous ejection is not possible (out of 5 nozzles, the number of nozzles capable of continuous ejection is 2 or less)
C: Cannot be discharged

[Preparation of sample for evaluation]
Each ink composition was applied onto a glass substrate (slide glass) with a spin coater so that the film thickness was 4 μm. The obtained membrane was placed in a nitrogen substitution box, the nitrogen substitution box was filled with nitrogen, and the membrane was irradiated with ultraviolet rays at an exposure amount of 350 mJ / cm ² . As a result, an evaluation sample was prepared as a base material having a light conversion layer.

[External Quantum Efficiency (EQE) Evaluation]
A blue LED (peak emission wavelength: 450 nm) manufactured by CCS Co., Ltd. was used as a 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. Insert each evaluation sample (base material having an optical conversion layer) prepared by the above method between the blue LED and the integrating sphere, turn on the blue LED, and measure the observed spectrum and illuminance at each wavelength. did.

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

Here, E (Blue) and P (Green) represent the following, respectively.
E (Blue): Represents the total value of "illuminance x wavelength ÷ hc" in the wavelength range of 380 to 490 nm.
P (Green): represents the total value of "illuminance x wavelength ÷ hc" in the wavelength range of 500 to 650 nm.
These are the values corresponding to the observed number of photons. In addition, h represents Planck's constant and c represents the speed of light.

For the external quantum efficiency (EQE), the EQE was measured before and after the evaluation sample was allowed to stand in a nitrogen atmosphere at room temperature for 3 weeks. The maintenance rate of external quantum efficiency (EQE) was calculated according to the following formula.
External quantum efficiency maintenance rate (%) = EQE ₁ / EQE ₀ x 100
Here, EQE ₀ is the external quantum efficiency before standing still, and EQE ₁ is the external quantum efficiency after standing still.

The evaluation of the external quantum efficiency maintenance rate was carried out according to the following criteria. The results are shown in Tables 1 and 2.
A: 96.0% or more B: 90.0% or more and less than 96.0% C: less than 90.0%

[Blue light transmittance (leakage rate) evaluation]
A blue LED (peak emission wavelength: 450 nm) manufactured by CCS Co., Ltd. was used as a surface emission light source. Each of the above evaluation samples (base material having a light conversion layer) prepared using the ink composition of the example was placed on this light source with the glass substrate side facing down. An integrating sphere was connected to a radiation spectrophotometer (trade name "MCPD-9800") manufactured by Otsuka Electronics Co., Ltd., and the integrating sphere was placed close to the evaluation sample installed on the blue LED. In this state, the blue LED was turned on and the peak intensity (S) of the observed light having a wavelength of 450 nm was measured. Next, light having a wavelength of 450 nm was observed in the same manner as in the above method except that the glass substrate (slide glass) used for preparing the evaluation sample was placed on the light source instead of each evaluation sample. The peak intensity (R) of light was measured. The leakage rate (blue light transmittance) T (peak intensity ratio: S / R × 100) of light having a wavelength of 450 nm was calculated. The leakage rate (blue light transmittance) was measured before and after the evaluation sample was allowed to stand in a nitrogen atmosphere at room temperature for 3 weeks. The smaller the light leakage rate, the higher the color purity, which is preferable. The results are shown in Table 3.

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 ... first light-scattering particles, 12b ... second light-scattering particles, 20 ... light-shielding part, 30 ... light conversion layer, 40 ... base material, 100 ... color filter.

Claims (17)

Luminescent nanocrystal particles (excluding luminescent nanocrystal particles containing a polyamine silicon ligand) , a monomer having an ethylenically unsaturated group, and a photopolymerization initiator (excluding polyfunctional thiol compounds). And a thiol compound having 2 or 3 primary mercapto groups .
An ink composition capable of forming an alkali-insoluble coating film . The ink composition according to claim 1, wherein the content of the photopolymerization initiator is 0.1 to 5.0% by mass based on the mass of the non-volatile content of the ink composition. The ink composition according to claim 1 or 2, further containing light-scattering particles. The ink composition according to claim 3, wherein the light-scattering particles have an average particle size of 0.05 to 1.0 μm. The ink composition according to claim 3 or 4, wherein the light-scattering particles contain at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate and barium titanate. thing. The ink composition according to any one of claims 1 to 5, further comprising a polymer dispersant. The ink composition according to claim 6, wherein the polymer dispersant has a weight average molecular weight of 1000 or more. The ink composition according to any one of claims 1 to 7, wherein the luminescent nanocrystal particles have an organic ligand on the surface thereof. The ink composition according to any one of claims 1 to 8, wherein the monomer is alkali-insoluble. The ink composition according to any one of claims 1 to 9 , wherein the surface tension is 20 to 40 mN / m. The ink composition according to any one of claims 1 to 10 , wherein the viscosity at 40 ° C. is 2 to 20 mPa · s. The ink composition according to any one of claims 1 to 11 , which is used for a color filter. The ink composition according to any one of claims 1 to 12, which is used in an inkjet method. An optical conversion layer having a plurality of pixel portions.
The plurality of pixel portions are optical conversion layers having pixel portions containing a cured product of the ink composition according to any one of claims 1 to 13 . Further, a light-shielding portion provided between the plurality of pixel portions is further provided.
The plurality of pixel portions are
The cured product is contained, and the luminescent nanocrystal particles include luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a emission peak wavelength in the range of 605 to 665 nm. , The first pixel part,
The cured product is contained, and the luminescent nanocrystal particles include luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a emission peak wavelength in the range of 500 to 560 nm. , The second pixel part,
The optical conversion layer according to claim 14 . The optical conversion layer according to claim 15 , wherein the plurality of pixel portions further include a third pixel portion having a transmittance of 30% or more with respect to light having a wavelength in the range of 420 to 480 nm. A color filter comprising the optical conversion layer according to any one of claims 14 to 16 .

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