JP7020015B2 - 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

The color filter pixel portion (hereinafter, also simply referred to as “pixel portion”) formed by the ink composition containing luminescent nanocrystal particles has optical characteristics (hereinafter, also simply referred to as “pixel portion”) from the viewpoint of low power consumption, wide color range, and the like. For example, further improvement of light emission characteristics) is required.

On the other hand, as a result of the studies by the present inventors, it is possible to improve the light emitting characteristics of the light emitting nanocrystal particles in the ink composition by increasing the affinity between the light emitting nanocrystal particles and the solvent. As a result, it became clear that the optical characteristics of the pixel portion can be improved. Here, the affinity between the luminescent nanocrystal particles and the solvent is evaluated by the emission intensity of the luminescent nanocrystal particles in the solvent, and the affinity between the luminescent nanocrystal particles and the solvent is evaluated. The high property means that the light emitting intensity of the luminescent nanocrystal particles in the solvent is high.

Therefore, an object of the present invention is to provide an ink composition having excellent affinity between luminescent nanocrystal particles and a solvent, and a light conversion layer and a color filter using the ink composition.

One aspect of the present invention relates to an ink composition containing luminescent nanocrystal particles and a solvent. In this ink composition, the solvent contains an acetate compound having a boiling point of 150 ° C. or higher. This ink composition has an excellent affinity between the luminescent nanocrystal particles and the solvent.

［式（１Ａ）中、Ｘａは、分子量５０以上の、アルキレン基、オキシアルキレン基又はこれらの基を組み合わせて構成される基であり、Ｙは、水素原子、メチル基又はアセチル基を示す。］ The acetate compound may be a compound represented by the following formula (1A), or may be a compound having an ether bond in the molecule.

[In the formula (1A), Xa is a group having a molecular weight of 50 or more and composed of an alkylene group, an oxyalkylene group or a combination of these groups, and Y represents a hydrogen atom, a methyl group or an acetyl group. ]

The content of the acetate compound may be 80% by mass or more based on the total mass of the solvent.

The ink composition may further contain a photopolymerizable compound. The photopolymerizable compound may be a photoradical polymerizable compound or a photocationic polymerizable compound. Further, the photopolymerizable compound may be alkali-insoluble.

The ink composition may further contain a thermosetting resin. This thermosetting resin may be alkali insoluble.

The ink composition may further contain light scattering particles. 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 silica. The average particle size of the light-scattering particles may be 0.05 to 1.0 μm.

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

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 may be 2 to 20 mPa · s.

The ink composition may be for a color filter. Further, 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. According to this optical conversion layer, excellent optical characteristics can be easily obtained.

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. According to this color filter, excellent optical characteristics can be easily obtained.

According to the present invention, it is possible to provide an ink composition having excellent affinity between luminescent nanocrystal particles and a solvent, and a light 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 and a solvent. In this ink composition, the solvent contains an acetate compound having a boiling point of 150 ° C. or higher. 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.

Since the ink composition having the above structure contains an acetate compound having a boiling point of 150 ° C. or higher as a solvent, the ink composition has excellent affinity between the luminescent nanocrystal particles and the solvent, and the luminescent nanocrystal particles have excellent luminescence. Can exhibit its characteristics. For example, when the luminescent nanocrystal particle dispersion of the present embodiment (for example, the luminescent nanocrystal particle dispersion having an organic ligand on the surface) is diluted 100-fold with the solvent of the present embodiment, the luminescence intensity is 700 (arb. u) That's all. Therefore, by using this ink composition, it is easy to obtain a pixel portion having excellent optical characteristics. The emission intensity when the luminescent nanocrystal particle dispersion of the present embodiment (for example, the luminescent nanocrystal particle dispersion having an organic ligand on the surface) is diluted 100-fold with the solvent of the present embodiment is preferably 700 (arb. u) or more, more preferably 1000 (arb.u) or more. The emission intensity can be measured by the method described in Examples.

By the way, when a color filter pixel portion is formed by an inkjet method using a conventional ink composition, the ejection stability from the inkjet nozzle may decrease due to aggregation of luminescent nanocrystal particles and light scattering particles. However, if the ejection cannot be performed stably by the inkjet method, the composition may vary in the formed pixel portion, and as a result, for example, leakage light (light from the light source is luminescent nanocrystals) in the pixel portion. (Light that leaks from the pixel portion without being absorbed by the particles) is generated, which causes problems such as deterioration of the color reproducibility of the pixel portion. Therefore, when the color filter pixel portion is formed by the inkjet method, the ink composition is required to have excellent ejection stability. On the other hand, in the ink composition having the above structure, the luminescent nanocrystal particles are easily dispersed well, and problems such as clogging caused by the volatilization of the solvent during continuous ejection are suppressed, so that the ink composition is excellent. Stability is easy to obtain. Therefore, according to the ink composition, excellent optical characteristics can be easily obtained even when the pixel portion is formed by the inkjet method. That is, the ink composition is suitably used for forming a color filter pixel portion by an inkjet method.

In the following, at least of luminescent nanocrystal particles, a solvent, a photopolymerizable component (photopolymerizable component containing a photopolymerizable compound), and a thermosetting component (thermosetting component including a thermosetting resin). On the other hand, an ink composition for a color filter (inkprint ink for a color filter) used in an inkjet method, which contains light-scattering particles and a polymer dispersant, 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 that emit light having an emission peak wavelength in the range of 605 to 665 nm (red light), and may be light having an emission peak wavelength in the range of 500 to 560 nm. It may be a green light emitting nanocrystal particle that emits (green light), or may be a blue light emitting nanocrystal particle that emits light (blue light) having an emission peak wavelength in the range of 420 to 480 nm. .. 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 an ultraviolet-visible spectrophotometer.

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 (hereinafter, also referred to as “QD”), quantum rods, and the like. 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, PbSnS, 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 ZnSeS 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 ZnSeS, 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 ZnSeS 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 diameter (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 or equal to 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.

As the organic ligand, a functional group for ensuring affinity with a resin and a solvent (hereinafter, also simply referred to as "affinity group") and a functional group for ensuring adsorption to luminescent nanocrystals (hereinafter, simply referred to as "affinity group"). Hereinafter, it is preferable that the compound has simply "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 hydrogen group, an amino group, a carboxyl group, a thiol group, a phosphoric acid group, a phosphonic acid group, a phosphine group, a phosphine oxide group, 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 is preferably an ethylene oxide chain and / or an ethylene oxide chain as an affinity group from the viewpoint of improving the affinity between the luminescent nanocrystal particles (luminescent nanocrystal particles modified with the organic ligand) and the solvent. It has an aliphatic hydrocarbon having a propylene oxide chain. The cause for the organic ligand to have an aliphatic hydrocarbon having an ethylene oxide chain and / or a propylene oxide chain to further improve the affinity between the luminescent nanocrystal particles and the solvent (that is, the luminescent nanocrystals in the solvent). The cause of further improvement in the emission intensity of the particles) is not clear, but desorption or substitution (ligand exchange) of the organic ligand by the acetate compound as a solvent is unlikely to occur, and the luminescent nanocrystal particles are maintained in a well-dispersed state. It is considered that one of the causes is possible. Also, when the organic ligand has an aliphatic hydrocarbon having an ethylene oxide chain and / or a propylene oxide chain, the affinity with the acetate compound having an ether bond tends to be better.

［式（２）中、ｐは０～５０の整数を示し、ｑは０～５０の整数を示す。］ Further, the organic ligand has a viewpoint that the affinity between the luminescent nanocrystal particles (luminescent nanocrystal particles modified with the organic ligand) and the solvent is better, and the dispersibility of the luminescent nanocrystal particles is improved. An organic ligand represented by the following formula (2) may be used from the viewpoint of improving the quality and obtaining better ejection stability. The organic ligand represented by the following formula (2) tends to improve the affinity between the luminescent nanocrystal particles and the solvent, particularly when the acetate compound has two or more acetyl groups.

[In equation (2), p indicates an integer of 0 to 50, and q indicates an integer of 0 to 50. ]

In the organic ligand represented by the formula (2), at least one of p and q is preferably 1 or more, and both p and q are more preferably 1 or more.

As the luminescent nanocrystal particles, those dispersed in a colloidal form in an organic solvent, a photopolymerizable compound, or the like can be used. The surface of the luminescent nanocrystal particles dispersed in the organic solvent is preferably passivated by the above-mentioned organic ligand. As the organic solvent, for example, cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether and the like can be used in addition to the solvent contained in the ink composition. The solvent may be a mixture of these.

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 may be 5% by mass or more, or 10% by mass or more, based on the mass of the non-volatile content of the ink composition, from the viewpoint of excellent effect of reducing leakage light. , 15% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more. The content of the luminescent nanocrystal particles may be 70% by mass or less, 60% by mass or less, 55 by mass, 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 50% by mass or less, or 50% by mass or less. When the luminescent nanocrystal particles are modified with an organic ligand, the total amount of the luminescent nanocrystal particles and the organic ligand that modifies the luminescent nanocrystal particles may be in the above range. 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.

［式（１）中、Ｘは、分子量５０以上の二価の有機基を示し、Ｙは、水素原子、メチル基、又はアセチル基を示す。］ (solvent)
The solvent contains an acetate compound having a boiling point of 150 ° C. or higher (hereinafter, also referred to as “first acetate compound”). The first acetate compound is, for example, a compound represented by the following formula (1) (excluding compounds having a boiling point of 150 ° C. or lower), and is a compound having one or more acetoxy groups. The first acetate compound may be used alone or in combination of two or more. The above-mentioned organic ligand and the later-described photopolymerizable component, thermosetting component and polymer dispersant are not included in the solvent.

[In the formula (1), X represents a divalent organic group having a molecular weight of 50 or more, and Y represents a hydrogen atom, a methyl group, or an acetyl group. ]

［式（１Ａ）中、Ｘａは、分子量５０以上の、アルキレン基、オキシアルキレン基又はこれらの基を組み合わせて構成される基であり、Ｙは、水素原子、メチル基又はアセチル基を示す。Ｘａ中、アルキレン基及びオキシアルキレン基は１つであっても複数であってもよい。］

［式（１Ｂ）中、Ｒ^１及びＲ^２はアルキレン基を示し、Ｙは、水素原子、メチル基又はアセチル基を示し、ｎ及びｍは、それぞれ独立して、０以上の整数を示し、ｎ＋ｍ≧１である。ただし、（Ｒ^１－Ｏ）ｎ－（Ｒ^２）ｍの分子量は５０以上である。］ The molecular weight of X in the formula (1) (mass of X in 1 mol of the compound represented by the formula (1)) may be 40 or more or 70 or more, or 200 or less. X is preferably an alkylene group, an oxyalkylene group, or a group composed of a combination of these groups, and more preferably, from the viewpoint of further improving the affinity between the luminescent nanocrystal particles and the solvent. Formula:-(R ¹ -O) n- (R ² ) m- (In the formula, R ¹ and R ² represent an alkylene group, n and m represent integers of 0 or more, and n + m ≧ 1). It is a group represented by (however, the molecular weight is 50 or more). That is, the first acetate compound is preferably a compound represented by the following formula (1A), and more preferably a compound represented by the following formula (1B).

[In the formula (1A), Xa is a group having a molecular weight of 50 or more and composed of an alkylene group, an oxyalkylene group or a combination of these groups, and Y represents a hydrogen atom, a methyl group or an acetyl group. In Xa, the alkylene group and the oxyalkylene group may be one or a plurality. ]

[In the formula (1B), R ¹ and R ² represent an alkylene group, Y represents a hydrogen atom, a methyl group or an acetyl group, and n and m each independently represent an integer of 0 or more, and n + m. ≧ 1. However, the molecular weight of (R1 ^- O) n- ( ^R2 ) m is 50 or more. ]

In the formulas (1A) and (1B), the alkylene group and the oxyalkylene group may have 2 or more carbon atoms and 10 or less carbon atoms. In formula (1B), R ¹ and R ² may be the same or different from each other. When there are a plurality of R ¹ and R ² , the plurality of R ¹ may be the same or different from each other, and the plurality of R ² may be the same or different from each other. Further, n may be 3 or less, and m may be 5 or less.

The number of acetyl groups in the first acetate compound is preferably 1 or more from the viewpoint of further improving the affinity with the luminescent nanocrystal particles. The number of acetyl groups may be 2 or more. That is, the acetate compound preferably has Y as an acetyl group among the compounds represented by the above formula (1B).

The number of acetoxy groups in the first acetate compound is preferably 1 or more from the viewpoint of further improving the affinity with the luminescent nanocrystal particles. The number of acetoxy groups may be 2 or more. That is, the acetate compound is preferably a compound represented by the above formula (1B) in which Y is an acetyl group and m is 0.

The first acetate compound is preferably a compound having an ether bond in the molecule from the viewpoint of further improving the affinity with the luminescent nanocrystal particles, for example, a compound having one or more oxyalkylene groups in the molecule. Is. From such a viewpoint, the acetate compound is preferably a compound having n of 2 or more or n and m of 1 or more among the compounds represented by the above formula (1B). On the other hand, from the viewpoint of increasing the boiling point, the first acetate compound does not have to have an ether bond.

Specific examples of the first acetate compound include monoacetate compounds such as diethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, and propylene. Examples thereof include a diacetate compound such as glycol diacetate and a triacetate compound such as glyceryl triacetate.

The boiling point of the first acetate compound 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 first acetate compound is preferably 300 ° C. or lower from the viewpoint of easy removal. ..

The content of the first acetate compound in the solvent is 50% by mass or more based on the total mass of the solvent from the viewpoint of being superior in the light emitting characteristics of the luminescent nanocrystal particles and further improving the ejection stability. It may be 70% by mass or more, 80% by mass or more, or 90% by mass or more. The content of the first acetate compound may be 100% by mass or less based on the total mass of the solvent.

The content of the first acetate compound in the ink composition is 10% by mass based on the total mass of the ink composition from the viewpoint of being superior in the light emitting characteristics of the luminescent nanocrystal particles and further improving the ejection stability. It may be more than 20% by mass, and may be 30% by mass or more. The content of the first acetate compound may be 90% by mass or less based on the total mass of the ink composition from the viewpoint of being superior in the light emitting characteristics of the luminescent nanocrystal particles and further improving the ejection stability. , 85% by mass or less, or 80% by mass or less.

The solvent may further contain an acetate compound having a boiling point of less than 150 ° C. (hereinafter, also referred to as “second acetate compound”). Examples of the second acetate compound include propylene glycol monomethyl ether acetate and the like.

The content of the second acetate compound in the solvent is 50% by mass or less based on the total mass of the solvent from the viewpoint of being superior in the light emitting characteristics of the luminescent nanocrystal particles and further improving the ejection stability. It may be 30% by mass or less, 20% by mass or less, or 10% by mass or less. The content of the second acetate compound may be 0% by mass. That is, the ink composition does not have to contain the second acetate compound.

The mass ratio of the content of the second acetate compound to the content of the first acetate compound (content of the second acetate compound / content of the first acetate compound) depends on the light emission characteristics of the luminescent nanoparticles. From the viewpoint of excellent viewpoint and the viewpoint of further improving the discharge stability, it is preferably 0.5 or less, more preferably 0.25 or less, and further preferably 0.1 or less.

The solvent may contain other solvent components other than the first and second acetate compounds. Examples of other solvent components include diethylene glycol dibutyl ether, propylene glycol dimethyl ether, tripropylene glycol dimethyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, diethyl succinate and the like. The boiling point of the other solvent is preferably 180 ° C. or higher from the viewpoint of continuous ejection stability of the inkjet ink, and preferably 300 ° C. or lower from the viewpoint of easy removal of the solvent.

The content of the solvent in the ink composition is the entire ink composition from the viewpoint of uniformly preparing the ink composition and increasing the fluidity of the ink composition to form a pixel portion with less unevenness. Based on the mass, it may be 10% by mass or more, 20% by mass or more, or 30% by mass or more. The above effect is remarkable when the thermosetting resin is used and the photopolymerizable compound is not used. The content of the solvent may be 90% by mass or less, 85% by mass or less, or 80% by mass or less based on the total mass of the ink composition.

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

When a photopolymerizable compound is used, it is possible to disperse light-scattering particles and luminescent nanocrystal particles in the photopolymerizable compound without a solvent, so that the solvent is removed by drying when forming the pixel portion. A solvent may not be used from the viewpoint of eliminating the need for the step of performing. On the other hand, in the present embodiment, by intentionally using an acetate compound having a boiling point of 150 ° C. or higher as a solvent, the content of luminescent nanocrystal particles can be increased while ensuring the viscosity suitable for inkjet, so that the ink coating film ( The light emission characteristics of the pixel portion) can be improved.

Examples of the photoradical polymerizable compound include (meth) acrylate compounds. The (meth) acrylate compound may be a monofunctional (meth) acrylate having one (meth) acryloyl group, or may be a polyfunctional (meth) acrylate having a plurality of (meth) acryloyl groups. Monofunctional (meth) acrylates and polyfunctional (meth) acrylates and polyfunctional (meth) acrylates and polyfunctional (meth) acrylates from the viewpoints of excellent fluidity when made into ink, excellent ejection stability, and suppression of deterioration of smoothness due to curing shrinkage during color filter manufacturing. ) It is preferable to use it in combination with acrylate. In addition, in this specification, (meth) acrylate means "acrylate" and corresponding "methacrylate". The same applies to the expression "(meth) acryloyl".

Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl. (Meta) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxy Ethyl (meth) acrylate, nonylphenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, Dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, benzyl (Meta) acrylate, phenylbenzyl (meth) acrylate, monosuccinate (2-acryloyloxyethyl), N- [2- (acryloyloxy) ethyl] phthalimide, N- [2- (acryloyloxy) ethyl] tetrahydrophthalimide, etc. Can be mentioned.

The polyfunctional (meth) acrylate may be a bifunctional (meth) acrylate, a trifunctional (meth) acrylate, a tetrafunctional (meth) acrylate, a pentafunctional (meth) acrylate, a hexafunctional (meth) acrylate, or the like, and may be, for example. A di (meth) acrylate in which two hydroxyl groups of a diol compound are substituted with a (meth) acryloyloxy group, and a di or tri (meth) acrylate in which two or three hydroxyl groups of a triol compound are substituted with a (meth) acryloyloxy group. And so on.

Specific examples of the bifunctional (meth) acrylate include 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, and 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 -Nonandiol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth). ) Acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentylglycol hydroxypivalic acid ester diacrylate, tris (2-hydroxyethyl) isocyanurate. Di (meth) acrylate substituted with a (meth) acryloyloxy group, two hydroxyl groups of a diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol are substituted with a (meth) acryloyloxy group. Di (meth) acrylate, bisphenol A di (meth) acrylate, trimethylol in which two hydroxyl groups of a diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of A is substituted with a (meth) acryloyloxy group. 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 propane is substituted with a (meth) acryloyloxy group, and 4 mol or more of ethylene is added to 1 mol of bisphenol A. Examples thereof include di (meth) acrylate in which two hydroxyl groups of the diol obtained by adding oxide or propylene oxide are substituted with a (meth) acryloyloxy group.

Specific examples of the trifunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, glycerin triacrylate, pentaerythritol tri (meth) acrylate, and trimethylolpropane to which 1 mol of ethylene oxide or propylene oxide is added. Examples thereof include tri (meth) acrylate in which the three hydroxyl groups of the resulting triol are substituted with a (meth) acryloyloxy group.

Specific examples of the tetrafunctional (meth) acrylate include pentaerythritol tetra (meth) acrylate.

Specific examples of the pentafunctional (meth) acrylate include dipentaerythritol penta (meth) acrylate.

Specific examples of the hexafunctional (meth) acrylate include dipentaerythritol hexa (meth) acrylate.

The polyfunctional (meth) acrylate may be a poly (meth) acrylate in which a plurality of hydroxyl groups of dipentaerythritol such as dipentaerythritol hexa (meth) acrylate are substituted with (meth) acryloyloxy groups.

The (meth) acrylate compound may be an ethylene oxide-modified phosphoric acid (meth) acrylate, an ethylene oxide-modified alkyl phosphoric acid (meth) acrylate, or the like, which has a phosphoric acid group.

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

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

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

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

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

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

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

In the ink composition of the present embodiment, when the curable component is composed of only the photopolymerizable compound or the main component thereof, the photopolymerizable compound as described above contains a polymerizable functional group in one molecule. It is more preferable to use a bifunctional or higher polyfunctional photopolymerizable compound having 2 or more as an essential component because the durability (strength, heat resistance, etc.) of the cured product can be further enhanced.

The photopolymerizable compound 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 photopolymerizable compound is alkali-insoluble means that the amount of the photopolymerizable compound dissolved in 1% by mass of potassium hydroxide aqueous solution at 25 ° C. is 30 based on the total mass of the photopolymerizable compound. It means that it is less than mass%. The dissolved amount of the photopolymerizable compound is preferably 10% by mass or less, more preferably 3% by mass or less.

The content of the photopolymerizable compound 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, it 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 photopolymerizable compound is the mass of the non-volatile content of 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 reducing leakage light). 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less. May be good.

The photopolymerizable compound has a crosslinkable group from the viewpoint of excellent stability of the pixel portion (cured product of the ink composition) (for example, deterioration over time can be suppressed, and high temperature storage stability and wet heat storage stability are excellent). You may be doing it. The crosslinkable group is a functional group that reacts with another crosslinkable group by heat or active energy rays (for example, ultraviolet rays), and is, for example, an epoxy group, an oxetane group, a vinyl group, an acryloyl group, an acryloyloxy group, a vinyl ether group, or the like. Can be mentioned.

[Photoradical polymerization initiator]
As the photoradical polymerization initiator, a molecular cleavage type or hydrogen abstraction type photoradical polymerization initiator is suitable.

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

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

[Photocationic polymerization initiator]
Examples of the photocationic polymerization initiator include polyarylsulfonium salts such as triphenylsulfonium hexafluoroantimonate and triphenylsulfonium hexafluorophosphate; diphenyliodonium hexafluoroantimonate and P-nonylphenyliodonium hexafluoroantimonate. And the like, polyaryliodonium salt and the like can be mentioned.

Commercially available products can also be used as the photocationic polymerization initiator. Commercially available products include sulfonium salt-based photocationic polymerization initiators such as "CPI-100P" manufactured by San-Apro, acylphosphine oxide compounds such as "Lucirin TPO" manufactured by BASF, and "Irgacure 907" and "Irgacure 907" manufactured by BASF. Examples thereof include "Irgacure 819", "Irgacure 379EG", ", Irgacure 184" and "Irgacure PAG290".

The content of the photopolymerization initiator may be 0.1 part by mass or more and 0.5 part by mass or more with respect to 100 parts by mass of the photopolymerizable compound from the viewpoint of curability of the ink composition. It may be 1 part by mass or more. The content of the photopolymerization initiator may be 40 parts by mass or less, and 30 parts by mass with respect to 100 parts by mass of the photopolymerizable compound, from the viewpoint of stability over time of the pixel portion (cured product of the ink composition). It may be less than or equal to 20 parts by mass or less.

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

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

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

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

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

Examples of the thermosetting resin having an epoxy group (including a polyfunctional epoxy resin) include a polymer of a monomer having an oxylan ring structure and a copolymer of a monomer having an oxylan ring structure and another monomer. Specific examples of the polyfunctional epoxy resin include polyglycidyl methacrylate, methyl methacrylate-glycidyl methacrylate copolymer, benzyl methacrylate-glycidyl methacrylate copolymer, n-butyl methacrylate-glycidyl methacrylate copolymer, and 2-hydroxyethyl methacrylate-glycidyl. Examples thereof include a methacrylate copolymer, a (3-ethyl-3-oxetanyl) methyl methacrylate-glycidyl methacrylate copolymer, and a styrene-glycidyl methacrylate. Further, as the thermosetting resin of the present embodiment, the compounds described in paragraphs 0044 to 0066 of JP-A-2014-56248 can also be used.

Examples of the polyfunctional epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, and naphthalene type epoxy. Resin, biphenyl type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional epoxy resin, tetraphenylol ethane type epoxy resin, dicyclopentadiene Phenolic type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, glioxal type epoxy resin, alicyclic epoxy resin , A heterocyclic epoxy resin, etc. can be used.

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

The polyfunctional epoxy resins include "Findick A-247S", "Findick A-254", "Findick A-253", "Findick A-229-30A", and "Findick A-229-30A" manufactured by DIC Corporation. "Findick A-261", "Findick A-249", "Findick A-266", "Findick A-241", "Findick M-8020", "Epoxy N-740", "Epoxy N-770" , "Epoxylon N-865" (trade name) and the like can be used.

When a polyfunctional epoxy resin having a relatively small molecular weight is used as the thermosetting resin, the epoxy group is replenished in the ink composition (inkjet ink), the reaction point concentration of the epoxy becomes high, and the crosslink density can be increased. can.

Among the polyfunctional epoxy resins, it is preferable to use an epoxy resin having four or more epoxy groups in one molecule (polyfunctional epoxy resin having four or more functionalities) from the viewpoint of increasing the crosslink density. In particular, when a thermosetting resin having a weight average molecular weight of 10,000 or less is used in order to improve the ejection stability from the ejection head in the inkjet method, the strength and hardness of the pixel portion (cured product of the ink composition) are lowered. From the viewpoint of sufficiently increasing the crosslink density, it is preferable to add a polyfunctional epoxy resin having four or more functionalities to the ink composition (inkjet ink).

The thermosetting resin may be alkali-insoluble from the viewpoint that a color filter pixel portion having excellent reliability can be easily obtained. When the thermosetting resin is alkali-insoluble, the amount of the thermosetting resin dissolved in 1% by mass of a potassium hydroxide aqueous solution at 25 ° C. is 30% by mass or less based on the total mass of the thermosetting resin. Means that. The dissolved amount of the thermosetting resin is preferably 10% by mass or less, and more preferably 3% by mass or less.

The weight average molecular weight of the thermosetting resin 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). And from the viewpoint of improving the wear resistance, it may be 750 or more, 1000 or more, or 2000 or more. From the viewpoint of obtaining an appropriate viscosity as an inkjet ink, it may be 500,000 or less, 300,000 or less, or 200,000 or less. However, this does not apply to the molecular weight after cross-linking. In the present specification, the weight average molecular weight is a polystyrene-equivalent weight average molecular weight measured by GPC (Gel Permeation Chromatography).

The content of the thermosetting resin 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, it 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 thermosetting resin is based on the mass of the non-volatile content of the ink composition from the viewpoint that the viscosity of the inkjet ink does not become too high and the thickness of the pixel portion does not become too thick for the light conversion function. It may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[Curing agent and curing catalyst]
Examples of the curing agent and curing catalyst used for curing the thermosetting resin include 4-methylhexahydrophthalic anhydride, triethylenetetramine, diaminodiphenylmethane, phenol novolac resin, and tris (dimethylaminomethyl) phenol. Examples thereof include N, N-dimethylbenzylamine, 2-ethyl-4-methylimidazole, triphenylphosphine, 3-phenyl-1,1-dimethylurea and the like.

In the present embodiment, the ink composition contains at least one of a photopolymerizable component (photopolymerizable component containing a photopolymerizable compound) and a thermosetting component (thermosetting component including a thermosetting resin). It may contain both a photopolymerizable component and a thermosetting component. When the ink composition contains a photopolymerizable component, it does not have to contain a thermosetting component. Further, when the ink composition contains a thermosetting component, it does not have to contain a photopolymerizable component. A photopolymerizable component from the viewpoint of storage stability of an ink composition containing luminescent nanocrystal particles (for example, quantum dots) and durability (wet heat stability, etc.) of a pixel portion (cured product of the ink composition). And, among the heat-curable components, it is preferable to use the heat-curable component, the storage stability of the ink composition containing luminescent nanoparticles (for example, quantum dots), and the low temperature which is not easily deteriorated by heating of the quantum dots. From the viewpoint of enabling curing in the field, it is more preferable to use a photopolymerizable component containing a photopolymerizable compound as the photopolymerizable component, and the pixel portion (ink composition) is not affected by oxygen inhibition in the curing process. From the viewpoint of forming a cured product), it is preferable to use a photopolymerizable component containing a photocationically polymerizable compound as the photopolymerizable component.

When the ink composition contains a photopolymerizable compound and a thermosetting resin, the total content of the photopolymerizable compound and the thermosetting resin is the viewpoint that an appropriate viscosity for an inkjet ink can be easily obtained, and the ink composition is cured. From the viewpoint of improving the properties and improving the solvent resistance and abrasion resistance of the pixel portion (cured product of the ink composition), the content is 3% by mass or more based on the mass of the non-volatile content of the ink composition. It may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. Further, the total content of the photopolymerizable compound and the thermosetting resin is an ink composition from the viewpoint that the viscosity of the inkjet ink does not become too high and the thickness of the pixel portion does not become too thick for the light conversion function. It may be 80% by mass or less, 60% by mass or less, or 50% by mass or less based on the mass of the non-volatile content of the above.

(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 preferably contain at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate and silica from the viewpoint of excellent effect of reducing leakage light. It is more preferable to contain at least one selected from the group consisting of titanium oxide, barium sulfate and calcium carbonate.

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 more 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, or 0.2 μm or more, from the viewpoint of excellent effect of reducing leaked light. It may be 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 being more excellent in 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 may be 0.1% by mass or more, or even 1% by mass or more, based on the mass of the non-volatile content of the ink composition from the viewpoint of excellent effect of reducing leakage light. It may be 5% by mass or more, 7% by mass or more, 10% by mass or more, or 12% by mass or more. The content of the light-scattering particles may be 60% by mass or less, and 50% by mass, based on the mass of the non-volatile content of the ink composition from the viewpoint of excellent effect of reducing leakage light and excellent ejection stability. It may be less than or equal to 40% by mass, may be 30% by mass or less, may be 25% by mass or less, may be 20% by mass or less, and may be 15% by mass. It may be as follows. 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 luminescent nanocrystal particles (light-scattering particles / luminescent nanocrystal particles) is 0.1 or more from the viewpoint of excellent effect of reducing leakage light. It may be 0.2 or more, and may be 0.5 or more. The mass ratio (light-scattering particles / luminescent nanocrystal particles) may be 5.0 or less, and may be 2.0 or less, from the viewpoint of excellent effect of reducing leaked light and superior continuous ejection property during inkjet printing. It may be present, or it may be 1.5 or less. The reduction of leaked light by the light-scattering 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, when 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 increases. As a result, it is considered that such a mechanism makes it possible to prevent light leakage.

(Polymer dispersant)
In the present invention, 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. Have. 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, the effect of reducing leakage light tends to decrease, and it is difficult to achieve both ejection stability and reduction of leakage light at a high level. On the other hand, according to the ink composition further containing the polymer dispersant, excellent ejection stability and reduction of leakage light 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 phosphin oxide group and a phosphin 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. The Efka series and the like 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, or even 1000 or more, from the viewpoint of being able to satisfactorily disperse light-scattering particles and improving the effect of reducing leakage light. 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, improve the effect of reducing leakage light, and can eject the viscosity of inkjet ink, which is suitable for stable ejection. From this point of view, 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.

The ink composition contains luminescent nanocrystal particles, a solvent, a photopolymerizable component, a thermosetting component, a light scattering particle, a polymer dispersant, and other components other than the organic ligand, as long as the effects of the present invention are not impaired. May be further contained. Examples of other components include sensitizers and the like.

(Sensitizer)
As the sensitizer, amines that do not cause an addition reaction with the photopolymerizable compound and the thermosetting resin 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. The content of the sensitizer may be 0.001% by mass or more and may be 1% by mass or less based on the mass of the non-volatile content of the ink composition.

The ink composition of the present embodiment described above can be applied as an ink used in a known and conventional method for producing a color filter, but relatively expensive materials such as luminescent nanocrystal particles and a solvent can be wasted. The color filter pixel part (optical conversion layer) can be formed only by using the required amount in the required place without using it, and it is appropriately prepared and used so as to be more suitable for the inkjet method than for the photolithography method. Is preferable.

The viscosity of the ink composition 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. The viscosity of the ink composition may be 20 mPa · s or less, 15 mPa · s or less, or 12 mPa · s or less. When the viscosity of the ink composition is 2 mPa · s or more, the meniscus shape of the ink composition at the tip of the ink ejection hole of the ejection head is stable, so that the ejection control of the ink composition (for example, the ejection amount and the ejection timing) Control) becomes easy. On the other hand, when the viscosity is 20 mPa · s or less, the ink composition can be smoothly ejected from the ink ejection holes. The viscosity of the ink composition is 2 to 20 mPa · s, 2 to 15 mPa · s, 2 to 12 mPa · s, 5 to 20 mPa · s, 5 to 15 mPa · s, 2 to 20 mPa · s, 7 to 15 mPa · s, 7 to 12 mPa. It may be s or 7 to 12 mPa · s. The viscosity of the ink composition is measured, for example, by an E-type viscometer. The viscosity of the ink composition can be adjusted to a desired range by changing, for example, the photocurable component, the thermosetting component, the weight average molecular weight of the polymer dispersant, the content of the solvent, and the like.

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 less, 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. The surface tension of the ink composition can be adjusted to a desired range by using, for example, a silicon-based surfactant, a fluorine-based surfactant, an acetylene-based surfactant, or the like in combination.

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. In this case, the ink composition contains an alkali-soluble resin as the binder polymer.

When the ink composition is used in a photography method, first, the ink composition is applied onto a substrate, and the ink composition is 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.

Further, even when the coating film of the ink composition is not treated with an alkaline developer, when the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere, and the time is long. As time passes, 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 photopolymerizable compound and / or an alkali-insoluble thermosetting resin as the photopolymerizable compound and / or the thermosetting resin. The fact that the coating film of the ink composition is 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 the thickness is obtained by applying the ink composition on a substrate and then drying it at 80 ° C. for 3 minutes. It can be confirmed by measuring the above-mentioned dissolution amount of the 1 μm coating film.

<Manufacturing method of ink composition>
Next, a method for producing the ink composition of the above-described embodiment will be described. The method for producing an ink composition comprises at least a step of mixing a solvent and luminescent nanocrystal particles (for example, a dispersion of luminescent nanocrystal particles). For example, an ink composition can be obtained by mixing the constituent components of the above-mentioned ink composition and performing a dispersion treatment.

The method for producing the ink composition includes, for example, a dispersion of light-scattering particles containing light-scattering particles and a polymer dispersant, and a dispersion of luminescent nano-crystal particles containing luminescent nanoparticles. The first step of preparing the above, and the second step of mixing the dispersion of the light-scattering particles and the dispersion of the luminescent nanocrystal particles are provided. In this method, the dispersion of the light scattering particles may further contain at least one of a solvent, a photopolymerizable component and a thermosetting component, and in the second step, the solvent, the photopolymerizable component and the heat. At least one of the curable components (eg, a solution containing a solvent and a thermocurable component) may be further mixed. According to this method, the light scattering particles can be sufficiently dispersed. Therefore, the leakage light in the pixel portion can be reduced, and an ink composition having excellent ejection stability can be easily obtained.

In the step of preparing a dispersion of light-scattering particles, a light-scattering particle, a polymer dispersant, and optionally at least one of a solvent, a photopolymerizable component, and a thermosetting component are mixed and dispersed. A dispersion of light-scattering particles may be prepared by performing the treatment. The mixing and dispersion treatment may be performed using a dispersion device such as a bead mill, a paint conditioner, or a planetary stirrer. 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.

A method for producing an ink composition is a method for producing luminescent nanocrystal particles, which comprises luminescent nanocrystal particles and at least one of a solvent, a photopolymerizable component and a thermosetting component before the second step. It may further include a step of preparing a dispersion. In this case, in the second step, a dispersion of light-scattering particles, a dispersion of luminescent nanocrystal particles, and optionally at least one of a solvent, a photopolymerizable component, and a thermosetting component are mixed. do. According to this method, the luminescent nanocrystal particles can be sufficiently dispersed. Therefore, the leakage light in the pixel portion can be reduced, and an ink composition having excellent ejection stability can be easily obtained. In the step of preparing the dispersion of the luminescent nanocrystal particles, the luminescent nanocrystal particles, the solvent, the photopolymerizable component, and the heat curing are used in the same dispersive device as in the step of preparing the dispersion of the light scattering particles. Mixing with the sex component and dispersion treatment may be performed.

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.

<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 of a photopolymerizable compound and / or a thermosetting resin, and specifically, a cured product obtained by polymerization of a photopolymerizable compound and / or crosslinking of a thermosetting resin. 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 5% by mass or more based on the total mass of the cured product of the ink composition from the viewpoint of excellent effect of reducing leakage light. It may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more. May be good. The content of the luminescent nanocrystal particles may be 70% by mass or less, or 60% 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. It may be 55% by mass or less, or 50% by mass or less.

The content of the light-scattering particles in the pixel portion containing the cured product of the ink composition is 0.1% by mass or more based on the total mass of the cured product of the ink composition from the viewpoint of excellent effect of reducing leakage light. 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. You may. The content of the light-scattering particles may be 60% by mass or less based on the total mass of the cured product of the ink composition from the viewpoint of excellent effect of reducing leakage light 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 a composition containing the above-mentioned photopolymerizable compound and / or a thermosetting resin. The cured product contains a third cured component 13c. The third curing component 13c is a cured product of a photopolymerizable compound and / or a thermosetting resin, and specifically, a cured product obtained by polymerizing the photopolymerizable compound and / or cross-linking the thermosetting resin. Is. 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 photopolymerizable compound and / or the thermosetting resin has a transmission rate of 30% for light having a wavelength in the range of 420 to 480 nm. As long as it is as described above, among the components contained in the above-mentioned ink composition, components other than the photopolymerizable compound and the thermosetting resin 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, the solvent is volatilized by drying, and then the ink composition is cured by irradiation with active energy rays or heating.

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.

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.

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.

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

Further, the color filter may be provided with an ink receiving layer containing hydroxypropyl cellulose or 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 polymer is used as the binder polymer. 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, one or two of 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 do not contain luminescent nanocrystal particles. It may be a pixel portion containing a coloring material. As the color material that can be used here, a known color material can be used. For example, as the color material used for the red pixel portion (R), a diketopyrrolopyrrole pigment and / or an anionic red organic dye is used. Can be mentioned. Examples of the coloring material used for the green pixel portion (G) include at least one selected from the group consisting of a 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 solvent>
The following solvents 1 to 7 were prepared as the solvent.
Solvent 1: 1,4-butanediol diacetate (boiling point: 232 ° C)
Solvent 2: Diethylene glycol monobutyl ether acetate (boiling point: 247 ° C)
Solvent 3: Propylene glycol diacetate (boiling point: 190 ° C)
Solvent 4: Dipropylene glycol methyl ether acetate (boiling point: 213 ° C)
Solvent 5: 1,4-Butanediol diacetate (boiling point: 232 ° C) 80 parts by mass and propylene glycol monomethyl ether acetate (boiling point: 146 ° C) 20 parts by mass Solvent 6: Tripropylene glycol dimethyl ether (boiling point: 215 ° C)
Solvent 7: Propylene glycol dimethyl ether (boiling point: 96 ° C)

<Preparation of InP / ZnSeS / ZnS nanocrystal particle dispersion (nonvolatile content 30% by mass)>
[Synthesis of red light emitting nanocrystal particle core (InP core)]
5 g of trioctylphosphine oxide (TOPO), 1.46 g (5 mmol) of indium acetate and 3.16 g (15.8 mmol) of lauric acid were added to the reaction flask to obtain a mixture. The mixture was heated at 160 ° C. for 40 minutes in a nitrogen 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, and then the supernatant was tilted to obtain InP nanocrystal particles. Then, the obtained InP nanocrystal particles were dispersed in hexane.

[Preparation of indium laurate precursor solution]
10 g of 1-octadecene (ODE), 146 mg (0.5 mmol) of indium acetate and 300 mg (1.5 mmol) of lauric acid were added to the reaction flask to obtain a mixture. The mixture was heated at 140 ° C. for 2 hours under vacuum to obtain a transparent solution (indium laurate precursor solution). This precursor solution was kept in the glove box at room temperature until needed. Indium laurate has low solubility at room temperature and easily precipitates. Therefore, when using a precursor solution, the precipitated indium laurate in the precursor solution (ODE mixture) is heated to about 90 ° C to become transparent. After forming the solution, the desired amount was weighed and used.

[Synthesis of red light emitting nanocrystal particle shell (ZnSeS / ZnS shell)]
A hexane solution of InP nanocrystal particles (InP core) and an indium phosphide precursor solution were added to the reaction flask to obtain a mixture. The amount of the InP core added in the hexane solution and the precursor solution was adjusted so that the amount of the InP core was 25 mg and that of the indium phosphide was 5 g. After allowing the mixture to stand at room temperature for 10 minutes under vacuum, the temperature of the mixture was raised to 230 ° C. and kept at that temperature for 2 hours.

Then, the reaction temperature (temperature of the mixture) was lowered to room temperature, 0.7 g of oleic acid was added to the reaction flask, and the temperature was raised to 80 ° C. 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, 69 mg of diethylzinc and 66 mg of hexamethyldisilatian (ZnS precursor solution) dissolved in 2 ml of ODE were 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. Then, the reaction mixture was cooled to room temperature, and the obtained white precipitate was removed by centrifugation to obtain a transparent nanocrystal particle solution (ODE solution) in which InP / ZnSeS / ZnS nanocrystal particles were dispersed.

[Synthesis of ligand for luminescent nanocrystal particles]
After putting JEFAMINE M-1000 (manufactured by Huntsman) into a flask, succinic anhydride (manufactured by Sigma-Aldrich) having an equimolar amount with JEFAMINE M-1000 was added thereto while stirring in a nitrogen gas environment. The internal temperature of the flask was raised to 80 ° C. and stirred for 8 hours to obtain a ligand represented by the following formula (2A) as a pale yellow viscous oil.

[Preparation of InP / ZnSeS / ZnS nanocrystal particle dispersion by ligand exchange]
30-50 mg of the ligand obtained above was added to 1 ml of the nanocrystal particle solution obtained above. Then, the ligand was exchanged by heating at 90 ° C. for 3 to 15 hours. 6 ml of ethanol was added to 1 ml of the nanocrystal particle solution after ligand exchange. Subsequently, centrifugation is performed to precipitate the nanocrystal particles, and then the nanocrystal particles (InP / ZnSeS / ZnS nanos modified with a ligand represented by the above formula (2A)) are subjected to tilting of the supernatant and drying under vacuum. Crystal particles) were obtained. The obtained nanocrystal particles were dispersed in the solvent 1 so that the non-volatile content was 30% by mass to obtain the nanocrystal particle dispersion 1 (non-volatile content 30% by mass). Further, the nanocrystal particle dispersions 2 to 7 were obtained in the same manner as described above except that the solvents 2 to 7 were used instead of the solvent 1.

<Preparation of light-scattering particle dispersion>
Titanium oxide (trade name: MPT141, manufactured by Ishihara Sangyo Co., Ltd., average particle diameter (volume average diameter): 100 nm) was 2.4 g and a polymer dispersant (trade name: DISPERBYK) in a container filled with argon gas. -2164, BYK, "DISPERBYK" is a registered trademark) is mixed with 0.4 g and solvent 1, then zirconia beads (diameter: 1.25 mm) are added to the obtained mixture, and a paint conditioner is used. The mixture was dispersed by shaking for 2 hours, and the zirconia beads were removed with a polyester mesh filter to obtain a light-scattering particle dispersion 1 (nonvolatile content: 44% by mass). Light-scattering particle dispersions 2 to 7 were obtained in the same manner as above except that the solvents 2 to 7 were used instead of the solvent 1.

<Preparation of thermosetting resin solution>
0.28 g of thermosetting resin (acrylic resin having an epoxy group, trade name: Findick A-254, manufactured by DIC Co., Ltd., "Findick" is a registered trademark) and a curing agent (1-methylcyclohexane-4). , 5-Dicarboxylic acid anhydride, Tokyo Kasei Kogyo Co., Ltd. reagent) 0.09 g, curing catalyst (dimethylbenzylamine, Tokyo Kasei Kogyo Co., Ltd. reagent) 0.004 g, solvent 1 To obtain a thermosetting resin solution 1 (nonvolatile content: 30% by mass). Thermosetting resin solutions 2 to 7 were obtained in the same manner as above except that the solvents 2 to 7 were used instead of the solvent 1.

<Example 1>
(1) Preparation of Ink Composition (Ink Ink) 2.25 g of luminescent nanocrystal particle dispersion 1, 0.75 g of light-scattering particle dispersion 1, and 1.25 g of thermosetting resin solution 1. , And then the mixture was filtered through a filter having a pore size of 5 μm to obtain an ink composition. The average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition was 0.260 μm. In this example, the average particle diameter (volume average diameter MV) of the light-scattering particles in the ink composition is a dynamic light-scattering nanotrack particle size distribution meter (manufactured by Nikkiso Co., Ltd., trade name " It was measured using "Nanotrack").

(2) Evaluation of ejection stability The ink composition obtained in (1) above was continuously ejected for 10 minutes using an inkjet printer (manufactured by Fujifilm Dimatics, trade name "DMP-2850"). In addition, 16 nozzles are formed in the head portion for ejecting ink of this inkjet printer, and the amount of ink composition used per nozzle per ejection is 10 pL. Discharge stability was evaluated according to the following criteria. The results are shown in Table 1.
A: Continuous ejection is possible (continuous ejection is possible with 10 or more nozzles out of 16 nozzles)
B: Continuous ejection is not possible (out of 16 nozzles, the number of nozzles capable of continuous ejection is 9 or less)
C: Cannot be discharged

(3) Affinity evaluation Affinity of luminescent nanocrystal particles (InP / ZnS core-shell nanocrystal particles modified with a ligand represented by the above formula (2A)) and a solvent (solvent 1) used for preparing an ink composition. Sex (QD affinity) was evaluated by the following procedure.

A sample for QD affinity evaluation was prepared by adding 50 μl of the above InP / ZnSeS / ZnS nanocrystal particle dispersion 1 to 5 ml of the solvent 1. The QD affinity was evaluated based on the obtained emission intensity by measuring the QD emission intensity of the sample with a spectroscopic fluorometer (FP8600 manufactured by JASCO Corporation). A cell having an optical path length of 10 mm was used as the measurement cell, and "very low" was selected as the detection sensitivity. The value of the obtained emission intensity was taken as the value of the peak top of the spectrum. The evaluation criteria for affinity evaluation are as follows. The results are shown in Table 1.
A: Emission intensity is 1000 (arb.u) or more B: Emission intensity is 300 (arb.u) or more and less than 700 (arb.u) C: Emission intensity is less than 300 (arb.u)

<Examples 2 to 5 and Comparative Examples 1 to 2>
The solvents 2 to 7 were used instead of the solvent 1, that is, the luminescent nanocrystal particle dispersion 1, the light scattering particle dispersion 1, and the thermosetting resin solution 1 were used instead of the luminescent nanocrystal particle dispersion 1. Examples 2 to 5 and Comparative Examples 1 to 1 in the same manner as in Example 1 except that bodies 2 to 7, light scattering particle dispersions 2 to 7, and thermosetting resin solutions 2 to 7, respectively, were used. The ink composition of 2 was obtained. The average particle diameters (volume average diameter MV) of the light-scattering particles in each ink composition were 0.363 μm, 0.214 μm, 0.218 μm, and 0.322 μm in Examples 2 to 5, respectively. Using the obtained ink composition, ejection stability evaluation and affinity evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

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 (24)

Containing luminescent nanocrystal particles modified with an organic ligand and a solvent,
The solvent contains an acetate compound having a boiling point of 150 ° C. or higher.
The organic ligand is an ink composition having an aliphatic hydrocarbon group having an ethylene oxide chain and / or a propylene oxide chain and a carboxyl group . The ink composition according to claim 1, wherein the acetate compound is a compound represented by the following formula (1A).

[In the formula (1A), Xa is a group having a molecular weight of 50 or more and composed of an alkylene group, an oxyalkylene group or a combination of these groups, and Y represents a hydrogen atom, a methyl group or an acetyl group. ] The ink composition according to claim 1 or 2, wherein the acetate compound has an ether bond in the molecule. The ink composition according to any one of claims 1 to 3, wherein the content of the acetate compound is 80% by mass or more based on the total mass of the solvent. The ink composition according to any one of claims 1 to 4, further comprising a photopolymerizable compound. The ink composition according to claim 5, wherein the photopolymerizable compound is a photoradical polymerizable compound. The ink composition according to claim 5, wherein the photopolymerizable compound is a photocationically polymerizable compound. The ink composition according to any one of claims 5 to 7, wherein the photopolymerizable compound is alkali-insoluble. The ink composition according to any one of claims 1 to 8, further comprising a thermosetting resin. The ink composition according to claim 9, wherein the thermosetting resin is alkaline insoluble. The ink composition according to any one of claims 1 to 10, further comprising light-scattering particles. The ink composition according to claim 11, wherein the light-scattering particles include at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate and silica. The ink composition according to claim 11 or 12, wherein the light-scattering particles have an average particle size of 0.05 to 1.0 μm. The ink composition according to any one of claims 1 to 13, further comprising a polymer dispersant. The ink composition according to claim 14, 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 15, which can form an alkali-insoluble coating film. The ink composition according to any one of claims 1 to 16 , wherein the acetate compound is a diacetate compound . The ink composition according to any one of claims 1 to 17 , wherein the organic ligand is represented by the following formula (2) .

[In equation (2), p indicates an integer of 0 to 50, and q indicates an integer of 0 to 50. ] The ink composition according to any one of claims 1 to 18, which is used for a color filter. The ink composition according to any one of claims 1 to 19, 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 20. 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,
21. The optical conversion layer according to claim 21. 22. The optical conversion layer according to claim 22, 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 21 to 23.

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