JP2019131758A - Ink composition, photoconversion layer and color filter - Google Patents

Abstract

To provide an ink composition that can form a color filter pixel part having excellent external quantum efficiency.SOLUTION: An ink composition has light-emitting nano crystal particles, and an epoxy resin, with an epoxy group content of the epoxy resin being 0.0040 mol or less relative to 1 g of the light-emitting nano crystal particles.SELECTED DRAWING: Figure 1

Description

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

  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. Have 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, for example, luminescent nanocrystal particles such as quantum dots, quantum rods, and other inorganic phosphor particles A method of forming a color filter pixel portion such as a red pixel and a green pixel by using the above has been actively studied.

  By the way, in the manufacturing method of the color filter by the said photolithography method, there existed a fault that resist materials other than the pixel part containing the comparatively expensive luminescent nanocrystal particle | grains were wasted from the characteristic of the manufacturing method. Under such circumstances, in order to eliminate the waste of the resist material as described above, it has been considered to form a light conversion substrate pixel portion by an ink jet method (Patent Document 1).

International Publication No. 2008/001693

  A color filter pixel portion (hereinafter also simply referred to as a “pixel portion”) formed of an ink composition containing luminescent nanocrystal particles has an external quantum efficiency (EQE: External Quantum) from the viewpoint of reducing power consumption. There is a need for further improvement in efficiency)).

  Therefore, an object of the present invention is to provide an ink composition capable of forming a color filter pixel portion having excellent external quantum efficiency, and a light conversion layer and a color filter using the ink composition.

  One aspect of the present invention relates to an ink composition comprising luminescent nanocrystal particles and an epoxy resin, wherein an epoxy group amount of the epoxy resin is 0.0040 mol or less per 1 g of the luminescent nanocrystal particles. According to this ink composition, the external quantum efficiency of the pixel portion can be improved.

  The epoxy equivalent of the epoxy resin may be 195 eq / g or more, and the epoxy resin may have two or more epoxy groups in one molecule.

  The ink composition may further contain an organic ligand. The organic ligand may have a main chain containing a polyoxyalkylene group and one or more functional groups capable of binding to the light-emitting nanocrystal particles at at least one end of the main chain.

  The organic ligand has at least one first functional group capable of binding to the light-emitting nanocrystal particle at one end of the main chain, and has a second functional group different from the first functional group at the other end of the main chain. It may have a functional group.

  The first functional group is a carboxyl group, the second functional group is a hydroxyl group, and the organic ligand may have two or more first functional groups.

  The ink composition may further contain at least one curing agent selected from the group consisting of acid anhydrides and phenolic compounds.

  The ink composition may further contain light scattering particles.

  The epoxy resin may be alkali insoluble.

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

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

  The viscosity of the ink composition at 25 ° C. may be 2 to 20 mPa · s. The ink composition may further contain a solvent having a boiling point of 180 ° C. or higher.

  The ink composition may be for a color filter.

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

  One aspect of the present invention relates to a light conversion layer including a plurality of pixel portions, wherein the plurality of pixel portions include a pixel portion containing a cured product of the ink composition described above. This light conversion layer is excellent in the external quantum efficiency of the pixel portion.

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

  The plurality of pixel units may further include a third pixel unit having a transmittance of 30% or more for 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-described light conversion layer. This color filter is excellent in the external quantum efficiency of the pixel portion.

  An object of the present invention is to provide an ink composition that can form a color filter pixel portion having excellent external quantum efficiency, 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 an epoxy resin having two or more epoxy groups, and the epoxy group amount of the epoxy resin is 0.0040 mol per gram of luminescent nanocrystal particles. It is as follows. This ink composition is, for example, a color filter ink composition used for forming a pixel portion of a color filter by a method such as a photolithography method or an ink jet method.

  By the way, when forming a color filter pixel part by the inkjet system using the conventional ink composition, it was difficult to achieve both excellent ejection stability and excellent curability. Therefore, it has been more difficult to obtain a color filter pixel portion having excellent external quantum efficiency by the ink jet method. On the other hand, according to the ink composition of the embodiment, a color filter pixel portion having excellent external quantum efficiency can be obtained even in the ink jet method.

  The ink composition of the embodiment can be applied as an ink used in a known and commonly used method for producing a color filter, but without wasting waste of relatively expensive materials such as luminescent nanocrystal particles and solvents, It is preferable that the color filter pixel portion (light conversion layer) can be formed only by using a necessary amount at a required location, and that it is appropriately prepared and used so as to be suitable for the inkjet method rather than for the photolithography method. . In other words, the ink composition of the embodiment is suitably used for forming a color filter pixel portion by an ink jet method.

  In the following, an ink composition for a color filter (ink jet ink for a color filter) used for an ink jet system, containing luminescent nanocrystal particles, light scattering particles, and an epoxy resin having two or more epoxy groups. Will be described as an example.

[Luminescent nanocrystal particles]
The luminescent nanocrystal particle is a nano-sized crystal that absorbs excitation light and emits fluorescence or phosphorescence. For example, the maximum particle diameter 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 light-emitting nanocrystal particles may be red light-emitting nanocrystal particles (red light-emitting nanocrystal particles) that emit light having a light emission peak wavelength (red light) in the range of 605 to 665 nm, and have a wavelength of 500 to 560 nm. It may be a green light emitting nanocrystal particle (green light emitting nanocrystal particle) that emits light having a light emission peak wavelength in the range (green light), and light having a light emission peak wavelength in the range of 420 to 480 nm (blue light). Blue-emitting nanocrystal particles (blue-emitting nanocrystal particles). In the present embodiment, it is preferable that the ink composition includes 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 to 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 a fluorescence spectrum or a phosphorescence spectrum measured using a spectrofluorometer.

  The red-emitting nanocrystal particles are 665 nm or less, 663 nm or less, 660 nm or less, 658 nm or less, 655 nm or less, 653 nm or less, 651 nm or less, 650 nm or less, 647 nm or less, 645 nm or less, 643 nm or less, 640 nm or less, 637 nm or less, 635 nm or less The emission peak wavelength is preferably 632 nm or less or 630 nm or less, and the emission peak wavelength is preferably 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 value and lower limit value can be arbitrarily combined. In addition, also in the following similar description, the individually described upper limit value and lower limit value can be arbitrarily combined.

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

  Blue-emitting nanocrystalline particles have a peak emission wavelength at 480 nm or less, 477 nm or less, 475 nm or less, 467 nm or less, 465 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 452 nm or less, or 450 nm or less. The emission peak wavelength is preferably 450 nm or more, 445 nm or more, 440 nm or more, 435 nm or more, 430 nm or more, 428 nm or more, 425 nm or more, 422 nm or more, or 420 nm or more.

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

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

  The luminescent semiconductor nanocrystal particle may be composed of only a core including a first semiconductor material, and includes a core including the first semiconductor material and a second semiconductor material different from the first semiconductor material, And a shell covering at least a part of the core. In other words, the structure of the luminescent semiconductor nanocrystal particles may be a structure consisting only of the core (core structure) or a structure consisting of the core and the shell (core / shell structure). The luminescent semiconductor nanocrystal particle includes a third semiconductor material different from the first and second semiconductor materials in addition to the shell including the second semiconductor material (first shell), You may have further the shell (2nd shell) which coat | covers at least one part. In other words, the structure of the luminescent semiconductor nanocrystal particles may be a structure (core / shell / shell structure) including a core, a first shell, and a second shell. Each of the core and the shell may be a mixed crystal including two or more kinds of semiconductor materials (for example, CdSe + CdS, CIS + ZnS, etc.).

  The luminescent nanocrystal particles are selected from the group consisting of II-VI semiconductors, III-V semiconductors, I-III-VI semiconductors, IV semiconductors and I-II-IV-VI semiconductors as semiconductor materials. Preferably, at least one semiconductor material is included.

Specific semiconductor materials include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeTe, HgSeTe, HgSTe, Se. CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS InP, InAs, InSb, GaNP, GANAS, GaNSb, GaPAs, Ga Sb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAsIn, GaInNSB, GaInPAsInGa InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe; Si, Ge, SiC, SiGe, AgInSe 2, CuGaSe _2, CuInS _2, CuG _{S 2, CuInSe 2, AgInS 2} , AgGaSe 2, AgGaS 2, C, include Si and Ge. The luminescent semiconductor nanocrystal particles are easy to control the emission spectrum, and from the viewpoint of reducing production costs and improving mass productivity while ensuring reliability, CdS, CdSe, CdTe, ZnS, _{ZnSe, ZnTe, ZnO, HgS,} HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS 2, AgInSe 2, AgInTe 2, AgGaS 2, AgGaSe 2, AgGaTe 2, CuInS 2, CuInSe 2, CuInTe 2 It is preferable to contain at least one selected from the group consisting of CuGaS ₂ , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge, and Cu ₂ ZnSnS ₄ .

  Examples of the red light emitting semiconductor nanocrystal particles include CdSe nanocrystal particles and nanocrystal particles having a core / shell structure, where the shell portion is CdS and the inner core portion is CdSe. Nanocrystal particles having a core / shell structure, wherein the shell portion is CdS and the inner core portion is ZnSe, mixed crystal nanocrystal particles of CdSe and ZnS, InP nanocrystals A crystal particle, a nanocrystal particle having a core / shell structure, wherein the shell portion is ZnS and an inner core portion is InP, a nanocrystal particle having a core / shell structure, The shell part is a mixed crystal of ZnS and ZnSe and the inner core part is InP, the mixed crystal of CdSe and CdS, the mixed crystal of ZnSe and CdS. Nanocrystal particles having a core / shell / shell structure, wherein the first shell portion is ZnSe, the second shell portion is ZnS, and the inner core portion is InP. A crystal particle, a nanocrystal particle having a core / shell / shell structure, wherein the first shell portion is a mixed crystal of ZnS and ZnSe, the second shell portion is ZnS, and the inner core portion is Examples thereof include nanocrystal particles that are InP.

  Examples of the green light emitting semiconductor nanocrystal particles include CdSe nanocrystal particles, mixed crystal nanocrystal particles of CdSe and ZnS, and nanocrystal particles having a core / shell structure, where the shell portion is ZnS. Nanocrystal particles having an inner core portion of InP and nanocrystal particles having a core / shell structure, wherein the shell portion is a mixed crystal of ZnS and ZnSe and the inner core portion is InP. A nanocrystalline particle having a crystalline particle, a core / shell / shell structure, wherein the first shell portion is ZnSe, the second shell portion is ZnS, and the inner core portion is InP. , A nanocrystal particle having a core / shell / shell structure, wherein the first shell portion is a mixed crystal of ZnS and ZnSe, the second shell portion is ZnS, and the inner core portion is I Nanocrystalline particles or the like is P and the like.

  Examples of blue-emitting semiconductor nanocrystal particles include ZnSe nanocrystal particles, ZnS nanocrystal particles, and nanocrystal particles having a core / shell structure, where the shell portion is ZnSe and the inner core portion. , ZnS nanocrystal particles, CdS nanocrystal particles, nanocrystal particles having a core / shell structure, wherein the shell portion is ZnS and the inner core portion is InP, the core / shell A nanocrystalline particle having a structure, wherein the shell portion is a mixed crystal of ZnS and ZnSe and the inner core portion is InP, and the nanocrystalline particle having a core / shell / shell structure. The first shell portion is made of ZnSe, the second shell portion is made of ZnS, and the inner core portion is made of InP. The nanocrystalline particles have a core / shell / shell structure. A crystal grain, the first shell portion is a mixed crystal of ZnS and ZnSe, a second shell portion is ZnS, include nanocrystalline like core portion of the inner is InP. By changing the average particle diameter of the semiconductor nanocrystal particles with the same chemical composition, the color to be emitted from the particles can be changed to red or green. Further, as the semiconductor nanocrystal particles, it is preferable to use particles having the least adverse effect on the human body or the like. When semiconductor nanocrystal particles containing cadmium, selenium, etc. are used as luminescent nanocrystal particles, the semiconductor nanocrystal particles that do not contain the above elements (cadmium, selenium, etc.) as much as possible are selected and used alone, or the above elements It is preferable to use in combination with other luminescent nanocrystal particles so as to reduce as much 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, it is possible to further improve the uniformity and fluidity of the ink composition by using particles having less directionality (for example, spherical, tetrahedral, etc.). Is preferable.

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

  The luminescent nanocrystal particles preferably have an organic ligand on the surface thereof from the viewpoint of dispersion stability. The organic ligand may be coordinated to the surface of the luminescent nanocrystal particle, for example. In other words, the surface of the luminescent nanocrystal particle may be passivated by the organic ligand. In addition, 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 organic ligand, and the polymer dispersant is exchanged between the organic ligand and the polymer dispersant, thereby replacing the polymer dispersant on the surface of the luminescent nanocrystal particles. May be combined. However, from the viewpoint of dispersion stability when an inkjet ink is used, it is preferable that a polymer dispersant is added to the luminescent nanocrystal particles in which the organic ligand is coordinated.

  As an organic ligand, a functional group (hereinafter also simply referred to as “affinity group”) for ensuring affinity with an epoxy resin and an organic solvent, and a functional group (light emission) capable of binding to the luminescent nanocrystal particle. And a functional group for ensuring the adsorptivity to the conductive nanocrystal particles. The affinity group may be a substituted or unsubstituted aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or have a branched structure. The aliphatic hydrocarbon group may have an unsaturated bond or may not have an unsaturated bond. The substituted aliphatic hydrocarbon may be a group in which some of the carbon atoms of the aliphatic hydrocarbon group are substituted with oxygen atoms. The substituted aliphatic hydrocarbon group may include, for example, a (poly) oxyalkylene group. Here, the “(poly) oxyalkylene group” means at least one of an oxyalkylene group and a polyoxyalkylene group in which two or more alkylene groups are linked by an ether bond. Examples of the functional group that can be bonded to the luminescent nanocrystal particle include a hydroxyl group, an amino group, a carboxyl group, a thiol group, a phosphoric acid group, a phosphonic acid group, a phosphine group, a phosphine oxide group, and an alkoxysilyl group. Examples of organic ligands include TOP (trioctylphosphine), TOPO (trioctylphosphine oxide), oleic acid, oleylamine, octylamine, trioctylamine, hexadecylamine, octanethiol, dodecanethiol, hexylphosphonic acid (HPA) , Tetradecylphosphonic acid (TDPA), and octylphosphinic acid (OPA).

  The organic ligand preferably has a main chain containing a polyoxyalkylene group and one or more functional groups capable of binding to the luminescent nanocrystal particle at at least one end of the main chain. The polyoxyalkylene group contained in the main chain may be, for example, a polyoxyethylene group or a polyoxypropylene group. The main chain has, for example, a substituted or unsubstituted hydrocarbon group in addition to the polyoxyalkylene group. The functional group is, for example, a group that can be coordinated to the luminescent nanocrystal particle. The functional group may include, for example, a functional group that can bind to the light-emitting nanocrystal particle. Here, the main chain means the longest molecular chain constituting the compound. Carbon number of a substituted or unsubstituted hydrocarbon group may be 1-10, for example. In the substituted hydrocarbon group, a part of carbon atoms may be substituted with a hetero atom such as a sulfur atom or a nitrogen atom, a carbonyl group, or the like.

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

［式（１−１）中、ｐは０〜５０の整数を示し、ｑは０〜５０の整数を示す。］ In one embodiment, the organic ligand may be an organic ligand represented by the following formula (1-1).

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

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

  In one embodiment, the first functional group is a carboxyl group, the second functional group is a hydroxyl group, and the organic ligand may have two or more first functional groups. That is, in one embodiment, the organic ligand may have one or more carboxyl groups at one end of the main chain and a hydroxyl group at the other end of the main chain, and may have one terminal carboxyl of the main chain. It may have two or more groups and may have a hydroxyl group at the other end of the main chain.

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

In formula (1-2), A ¹ represents a monovalent group containing a carboxyl group, A ² represents a monovalent group containing a hydroxyl group, and R represents a hydrogen atom, a methyl group, or an ethyl group. L represents a substituted or unsubstituted alkylene group, and r represents an integer of 0 or more. The number of carboxyl groups in the monovalent group containing a carboxyl group may be 2 or more, 2 or more and 4 or less, and 2 may be used. The number of carbon atoms of the alkylene group represented by L may be, for example, 1 to 10. In the alkylene group represented by L, part of the carbon atoms may be substituted with a heteroatom, and is substituted with at least one heteroatom selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom. Also good. r may be an integer from 1 to 100, for example, and may be an integer from 10 to 20.

The organic ligand is preferably an organic ligand represented by the following formula (1-2A).

  In formula (1-2A), r is as defined above.

  The organic ligand is preferably an organic ligand represented by the formula (1-2A) from the viewpoint of the external quantum yield of the ink composition and the heat resistance of the external quantum yield of the cured product of the ink composition.

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

  A commercial item can be used as a luminescent nanocrystal particle. Examples of commercially available luminescent nanocrystal particles include indium phosphine / zinc sulfide, D-dot, CuInS / ZnS, and InP / ZnS from Aldrich, manufactured by NN-Labs.

  The content of the light-emitting nanocrystal particles may be 5% by mass or more based on the mass of the non-volatile content of the ink composition, and may be 10% by mass or more, from the viewpoint of excellent external quantum efficiency. It may be 15% by mass or more, 20% by mass or more, or 25% by mass or more. When the content of the luminescent nanocrystal particles is 5% by mass or more, excellent emission intensity can be obtained, and thus such an ink composition is suitably used as a color filter. From the same viewpoint, the content of the luminescent nanocrystal particles may be 50% by mass or less, 40% by mass or less, or 35% by mass or less based on the mass of the nonvolatile content of the ink composition. It may be 30% by mass or less. The content of the light-emitting nanocrystal particles is 50% by mass or less based on the mass of the non-volatile content of the ink composition from the viewpoint of superior discharge stability. In addition, when the content of the light-emitting nanocrystal particles is 50% by mass or less, excellent light emission intensity can be obtained. Therefore, such an ink composition is suitably used as a color filter. From the same viewpoint, the content of the luminescent nanocrystal particles may be 40% by mass or less, 35% by mass or less, and 30% by mass based on the mass of the nonvolatile content of the ink composition. It may be the following. The content of the light-emitting nanocrystal particles is 5 to 50% by mass, 10 to 50% by mass, 15 to 40% by mass, 15 to 35% by mass, and 20 to 35% by mass based on the mass of the nonvolatile content of the ink composition. % Or 20-30% by mass. In this specification, “the mass of the non-volatile content of the ink composition” refers to the mass obtained by subtracting the mass of the solvent from the total mass of the ink composition when the ink composition contains a solvent. When a solvent is not included, the total mass of the ink composition is indicated.

  The ink composition may contain two or more kinds of red light-emitting nanocrystal particles, green light-emitting nanocrystal particles, and blue light-emitting nanocrystal particles as the light-emitting nanocrystal particles. Contains only one of the particles. When the luminescent nanocrystal particles include red luminescent nanocrystal particles, the content of the green luminescent nanocrystal particles and the content of the blue luminescent nanocrystal particles are preferably based on the total mass of the luminescent nanocrystal particles. Is 10% by mass or less, more preferably 0% by mass. When the luminescent nanocrystal particles include green luminescent nanocrystal particles, the content of the red luminescent nanocrystal particles and the content of the blue luminescent nanocrystal particles are preferably based on the total mass of the luminescent nanocrystal particles. Is 10% by mass or less, more preferably 0% by mass.

[Epoxy resin]
The epoxy resin has at least one epoxy group in one molecule, and preferably has two or more epoxy groups in one molecule. The epoxy resin may be, for example, a condensate of a compound having two or more active hydrogens with epichlorohydrin, an olefin oxide, or the like. The condensate may be a glycidyl ether type epoxy resin, a glycidyl amine type epoxy resin, a glycidyl ester type epoxy resin or the like, and is preferably a glycidyl ether type epoxy resin. The glycidyl ether type epoxy resin is preferably a condensate of a compound having two or more hydroxyl groups such as bisphenol A, bisphenol F, and novolak with epichlorohydrin.

  The epoxy resin may not contain a monomer having a (meth) acryloyl group ((meth) acryl monomer) as a monomer unit. In the present specification, “(meth) acryloyl group” means “acryloyl group” and “methacryloyl group” corresponding thereto.

The epoxy resin may be, for example, a compound represented by the following formula (2).

  In formula (2), X represents an n-valent organic group having an aromatic ring, and n represents an integer of 2 or more. X may have at least one selected from the group consisting of a benzene ring and a naphthalene ring, and preferably has a benzene ring. These aromatic rings may or may not have a substituent.

The epoxy resin represented by the formula (2) may be a compound represented by the following formula (3), for example.

In formula (3), Y ¹ represents a divalent organic group having an aromatic ring, and n ¹ represents an integer of 0 or more. Y ¹ may have at least one selected from the group consisting of a benzene ring and a naphthalene ring, and preferably has a benzene ring. These aromatic rings may or may not have a substituent. A plurality of Y ¹ may be the same as or different from each other. n ¹ may be an integer of 0 to 10, for example.

The epoxy resin represented by the formula (3) is preferably a compound represented by the following formula (3A).

In Formula (3A), R ¹ represents a monovalent hydrocarbon group, Z ¹ represents a single bond, an alkylene group, an alkylidene group, a cycloalkylene group, or a bicycloalkylene group, and n ^1A represents an integer of 0 or more. M ^1A represents an integer of 0 to 4. A plurality of R ¹ , Z ¹ and m ^1A may be the same as or different from each other. R ¹ may be, for example, an alkyl group, a cycloalkyl group, a bicycloalkyl group, or an aryl group. The number of carbon atoms of the hydrocarbon group represented by R ¹ may be, for example, 1 to 10. The number of carbon atoms of the alkylene group represented by Z ¹ may be, for example, 1 to 10. The number of carbon atoms of the alkylidene group represented by Z ¹ may be, for example, 2-10. The cycloalkylene group represented by Z ¹ may have 5 to 10 carbon atoms, for example. The carbon number of the bicycloalkylene group represented by Z ¹ may be, for example, 8-14.

The epoxy resin represented by the formula (2) may be, for example, a compound represented by the following formula (4).

In formula (4), Y ² represents a divalent organic group having an aromatic ring, and n ² represents an integer of 0 or more. Y ² may have at least one selected from the group consisting of a benzene ring and a naphthalene ring, and preferably has a benzene ring. These aromatic rings may or may not have a substituent. A plurality of Y ² may be the same as or different from each other. n ² can be, for example, an integer of 0 to 20.

The epoxy resin represented by the formula (4) is preferably a compound represented by the following formula (4A).

In formula (4A), R ² represents a monovalent hydrocarbon group, Z ² represents a single bond, an alkylene group, an alkylidene group, a cycloalkylene group or a bicycloalkylene group, and n ^2A represents an integer of 0 or more. M ^2A represents an integer of 0 to 4. A plurality of R ² , Z ² and m ^2A may be the same or different from each other. R ² may be, for example, an alkyl group, a cycloalkyl group, a bicycloalkyl group, or an aryl group. The number of carbon atoms of the hydrocarbon group represented by R ² may be 1 to 10, for example. The alkylene group represented by Z ² may be, for example, 1 to 10. The number of carbon atoms of the alkylidene group represented by Z ² may be 2 to 10, for example. The number of carbon atoms of the cycloalkylene group represented by Z ² may be, for example, 5-10. The carbon number of the bicycloalkylene group represented by Z ¹ may be, for example, 8-14.

  As the epoxy resin, one kind of epoxy resin may be used alone, or a plurality of epoxy resins may be used in combination.

  The amount of epoxy groups of the epoxy resin present in the ink composition is 0.0040 mol or less per 1 g of the light-emitting nanocrystal particles, and preferably from 0.0030 mol or less, from the viewpoint of further improving the external quantum efficiency. It is 0020 mol or less, or 0.0010 mol or less. The amount of epoxy groups of the epoxy resin present in the ink composition may be, for example, 0.00010 mol or more, or 0.00030 mol or more per 1 g of the luminescent nanocrystal particles.

  From the viewpoint of improving the external quantum efficiency, the epoxy equivalent (g / eq) of the epoxy resin may be 195 or more, 400 or more, or 1000 or more, from the viewpoint of improving curability and improving the film strength. It may be 4000 or less. The epoxy equivalent can be measured according to the method described in JIS K7236: 2001.

  Specific examples of the epoxy resin include, for example, “EPICLON 860” (trade name, manufactured by DIC Corporation), “EPICLON 1050” (trade name, manufactured by DIC Corporation), “EPICLON 3050” (trade name, manufactured by DIC Corporation). ), “EPICLON 7050” (trade name, manufactured by DIC Corporation), “EPICLON HM-091” (trade name, manufactured by DIC Corporation), etc., bisphenol A type solid epoxy resin, “EPICLON 850-S” (trade name, DIC Corporation), "EPICLON EXA-850CRP" (trade name, manufactured by DIC Corporation) and other bisphenol A type liquid epoxy resins, and "EPICLON N-865" (trade name, manufactured by DIC Corporation) and other modified novolak type Epoxy resin, “EPICLON HP-4032D” (trade name Naphthalene type epoxy resin of DIC Co., Ltd.).

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

  The content of the epoxy resin is the viewpoint that an appropriate viscosity is easily obtained as an inkjet ink, the viewpoint that the curability of the ink composition is good, and the solvent resistance and wear resistance of the pixel portion (cured product of the ink composition). From the viewpoint of improving the ink composition, 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 nonvolatile content of the ink composition. The content of the epoxy resin is based on the non-volatile content of the ink composition from the viewpoint that an appropriate viscosity is easily obtained as an ink-jet ink and from the viewpoint that more excellent optical characteristics (for example, external quantum efficiency) are obtained. 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.

  The epoxy resin may be used as a thermosetting resin that is crosslinked and cured by heat, or may be used as a photopolymerizable compound (resin) that is polymerized by light irradiation. In other words, the ink composition may contain a thermosetting component or a photopolymerizable component containing an epoxy resin. In addition to these, a polymer having no polymerization reactivity per se may be further used.

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

  Examples of acid anhydride curing agents include 4-methylcyclohexane-1,2-dicarboxylic acid anhydride (4M-HHPA), 3-methylcyclohexane-1,2-dicarboxylic acid anhydride, cyclohexane-1,2-dicarboxylic acid. Anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, Bicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride, methylbicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride, methyl-3,6 endomethylene-1,2 , 3,6-tetrahydrophthalic anhydride, 3,6 endomethylene-1,2,3,6-tetrahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, none Water maleic acid and the like can be mentioned.

  As phenolic compounds (phenolic curing agents), bisphenol A, bisphenol F, bisphenol S, resorcin, catechol, hydroquinone, fluorene bisphenol, 4,4'-biphenol, 4,4 ', 4 "-trihydroxytriphenylmethane , Naphthalenediol, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, calixarene, novolac type phenolic resin (for example, phenol novolac resin, cresol novolac resin, bisphenol A novolac resin, bisphenol S novolac resin, resorcinol) Polyhydric phenol novolak resin synthesized from polyhydric hydroxy compound represented by novolak resin and formaldehyde, naphthol-phenol co-condensed novolak resin, naphthol Cresol-condensed novolak resin, naphthol novolak resin, alkoxy group-containing aromatic ring-modified novolak resin (polyhydric phenol compound in which phenol nucleus and alkoxy group-containing aromatic ring are linked with formaldehyde), aralkyl type phenol resin (for example, zylock) Phenol aralkyl resins such as resins and naphthol aralkyl resins), aromatic hydrocarbon formaldehyde resin modified phenol resins, dicyclopentadiene phenol addition type resins, trimethylol methane resins, tetraphenylol ethane resins, biphenyl modified phenol resins (phenols with bismethylene groups) Polyphenol compound with nuclei linked), biphenyl-modified naphthol resin (polyvalent naphthol compound with phenol nuclei linked by bismethylene group), aminotriaz Polyphenolic compounds such as modified phenolic resins (polyhydric phenolic compounds in which phenolic nuclei are linked with melamine, benzoguanamine, etc.), etc. From the viewpoint of excellent external quantum efficiency improvement, phenolic compounds are novolak phenols. As the novolak type phenol resin, a phenol novolak resin, a cresol novolak resin, and a bisphenol A novolak resin are preferably used.

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

  Examples of amine compounds include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and pentaethylenehexamine, and aromatics such as metaxylylenediamine, diaminodiphenylmethane, and phenylenediamine. Examples include polyamines, alicyclic polyamines such as 1,3-bis (aminomethyl) cyclohexane, isophoronediamine, norbornanediamine, and the like, and polyamide resins synthesized from dimers of dicyandiamide and linolenic acid and ethylenediamine.

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

  The content of the curing agent may be, for example, 40% by mass or less, 30% by mass or less, or 20% by mass or less based on the mass of the nonvolatile content of the ink composition.

  In the case of heat curing, the ink composition may further contain a curing accelerator. A hardening accelerator may be used independently and may be used together with the said hardening | curing agent. As the curing accelerator, various compounds that promote the curing reaction of the epoxy resin can be used. Examples of the curing accelerator include phosphorus compounds, tertiary amine compounds, imidazole compounds, organic acid metal salts, Lewis acids, amine complex salts, and the like. Examples of the phosphorus compound include triphenylphosphine, tripalatolylphosphine, and diphenylcyclohexylphosphine. Examples of the tertiary amine compound include 1,8-diazabicyclo (5,4,0) undecene-7, 1,5-diazabicyclo (4,3,0) nonene-5, and tris (dimethylaminomethyl) phenol. It is done. Examples of the imidazole compound include 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole.

  The epoxy resin is used together with a photopolymerization initiator when used as a photopolymerizable compound. The photoradical polymerizable compound is used with a photoradical polymerization initiator, and the photocationic polymerizable compound is used with a photocationic polymerization initiator. In other words, the ink composition may contain a photopolymerizable component including a photopolymerizable compound and a photopolymerization initiator.

  The photopolymerization initiator is not particularly limited as long as it is an initiator for ring-opening polymerization of an epoxy group by light irradiation, and may be, for example, an ionic photoacid generating type or a nonionic photoacid generating type. It may be.

  The cationic photopolymerization initiator of the ionic photoacid generation type is not particularly limited, and onium salts such as aromatic diazonium salts, aromatic halonium salts, aromatic sulfonium salts, iron-allene complexes, titanocene complexes, arylsilanol-aluminums And organometallic complexes such as complexes. These ionic photoacid-generating photocationic polymerization initiators may be used alone or in combination of two or more.

  The nonionic photoacid-generating photocationic polymerization initiator is not particularly limited. For example, nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, phenolsulfonic acid ester, diazonaphthoquinone, N-hydroxyimide phosphonate Etc. These nonionic photoacid-generating photocationic polymerization initiators may be used alone or in combination of two or more.

  In the case of photocuring, a sensitizer can be added as appropriate in order to improve the sensitivity of light and to give sensitivity to the wavelength of light from the light source. These sensitizers can be used in combination with the above cationic photopolymerization initiator to adjust the curability. Examples of the sensitizer to be added include anthracene compounds and thioxanthone compounds.

  In the case of photocuring, as a light source for curing, a light source that emits an absorption wavelength of a photopolymerization initiator or a sensitizer to be used may be used, and a light source that usually includes a wavelength in the range of 200 to 450 nm, For example, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, a high power metal halide lamp, a xenon lamp, a carbon arc lamp, a light emitting diode, or the like can be used.

  The content of the photopolymerization initiator may be 0.1 parts by mass or more and 0.5 parts 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 temporal stability of the pixel part (cured product of the ink composition). Or 20 parts by mass or less.

  The components contained in the ink composition of the present embodiment have been described above. However, the ink composition of the present embodiment may further contain components (other components) other than those described above. Examples of other components include light scattering particles, polymer dispersants, solvents, and the like.

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

  Examples of the material constituting the light scattering particles include simple metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum, and gold; silica, barium sulfate, barium carbonate, calcium carbonate, Metal oxides such as talc, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, alumina white, titanium oxide, magnesium oxide, barium oxide, aluminum oxide, bismuth oxide, zirconium oxide, zinc oxide; magnesium carbonate, barium carbonate, Metal carbonates such as bismuth subcarbonate and calcium carbonate; metal hydroxides such as aluminum hydroxide; complex oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, strontium titanate, bismuth subnitrate Such as metal And the like. From the viewpoint of excellent discharge stability and the effect of improving external quantum efficiency, the light scattering particles are made of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, barium titanate and silica. It is preferable to include at least one selected, and more preferable to include at least one selected from the group consisting of titanium oxide, zirconium oxide, zinc oxide, and barium titanate.

  The shape of the light scattering particles may be spherical, filamentous, indeterminate. However, as the light scattering particles, it is possible to use particles having less directivity as the particle shape (for example, spherical, tetrahedral, etc. particles), thereby improving the uniformity, fluidity and light scattering of the ink composition. This is preferable in that it can be increased and excellent discharge stability can be obtained.

  The light-scattering particles may be those in which at least a part of the surface is covered with alumina. Of the surface of the light scattering particles, for example, 50 area% or more may be covered with alumina, and the entire surface of the light scattering particles may be covered with alumina. In this case, the light scattering particles can be rephrased as light scattering particles surface-treated with alumina.

  As a method of covering at least a part of the surface of the light scattering particles with alumina (surface treatment with alumina), for example, a wet processing method (adding an aluminum salt aqueous solution to the light scattering particle slurry and neutralizing the solution) And a method of adsorbing on the surface of the light scattering particles). Examples of the light scattering particles include “MPT-141”, “CR-50”, “CR-50-2”, “CR-58”, “CR-58-2”, “CR” manufactured by Ishihara Sangyo Co., Ltd. Commercial products such as “−60”, “CR-60-2”, “JR405”, “JR603”, “JR605”, “JR701”, and “JR806” manufactured by Teika Co., Ltd. can also be used. The surface of the light scattering particles may be covered with alumina and other components such as silica, zinc oxide, titanium oxide, zirconium oxide, and organic substances such as stearic acid and polysiloxane.

  The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 0.05 μm or more from the viewpoint of excellent ejection stability and the effect of improving external quantum efficiency. It may be 2 μm or more, or 0.3 μm or more. The average particle diameter (volume average diameter) of the light-scattering particles in the ink composition may be 1.0 μm or less, 0.6 μm or less, from the viewpoint of excellent ejection stability. It may be 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, and 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 of easily obtaining such an average particle diameter (volume average diameter), the average particle diameter (volume average diameter) of the light-scattering particles used may be 50 nm or more and 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. The average particle diameter (volume average diameter) of the light-scattering particles used is 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 and 1% by mass or more based on the non-volatile content of the ink composition from the viewpoint of excellent external quantum efficiency. It may be 5 mass% or more, 7 mass% or more, 10 mass% or more, or 12 mass% or more. The content of the light scattering particles may be 60% by mass or less, based on the mass of the non-volatile content of the ink composition, from the viewpoint of excellent ejection stability and the effect of improving external quantum efficiency, and 50 mass. % Or less, 40% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, or 15% by weight. % Or less. In this embodiment, since the ink composition contains a polymer dispersant, the light scattering particles can be favorably dispersed even when the content of the light scattering particles is in the above range.

  The mass ratio of the content of the light-scattering particles to the content of the light-emitting nanocrystal particles (light-scattering particles / light-emitting nanocrystal particles) was 0.1 or more from the viewpoint of excellent external quantum efficiency improvement effect. 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 from the viewpoint of excellent external quantum efficiency improvement effect and excellent continuous discharge property (discharge stability) during ink jet printing. 2.0 or less, or 1.5 or less. In addition, it is thought that the improvement of external quantum efficiency by light-scattering particles is due to the following mechanism. That is, when no light-scattering particles are present, it is considered that the backlight light only passes almost straight through the pixel portion and is less likely to be absorbed by the light-emitting nanocrystal particles. On the other hand, if the light-scattering particles are present in the same pixel portion as the light-emitting nanocrystal particles, the backlight light is scattered in all directions in the pixel portion, and the light-emitting nanocrystal particles can receive it. Even if the same backlight is used, it is considered that the light absorption amount in the pixel portion increases. As a result, it is possible to prevent leaking light (light leaking from the pixel portion without being absorbed by the light-emitting nanocrystal particles) by such a mechanism, and improve external quantum efficiency. It is considered possible.

[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 the light scattering particles, and the function of dispersing the light scattering particles. Have The polymer dispersing agent is adsorbed to the light scattering particle via a functional group having affinity for the light scattering particle, and the light scattering particle is formed by electrostatic repulsion and / or steric repulsion between the polymer dispersing agents. Disperse in the ink composition. The polymer dispersant is preferably bonded to the surface of the light-scattering particle and adsorbed to the light-scattering particle, but is bonded to the surface of the light-emitting nanocrystal particle and adsorbed to the light-emitting nanoparticle. It may be free in the ink composition.

  By the way, when forming the color filter pixel portion by the ink jet method using the conventional ink composition, one of the causes of the decrease in the ejection stability is considered to be aggregation of the luminescent nanocrystal particles and the light scattering particles. . Therefore, it is conceivable to improve the ejection stability by miniaturizing the luminescent nanocrystal particles and the light-scattering particles and reducing the content of the luminescent nanocrystal particles and the light-scattering particles. In this case, the effect of improving the external quantum efficiency is likely to be reduced, and it is difficult to achieve both the discharge stability and the improvement of the external quantum efficiency at a high level. On the other hand, according to the ink composition further containing the polymer dispersant, it is possible to achieve both excellent ejection stability and improvement in external quantum efficiency at a high level. The reason why such an effect is obtained is not clear, but the polymer dispersant significantly suppresses aggregation of the light-emitting nanocrystal particles and the light-scattering particles (particularly, the light-scattering particles). It is guessed.

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

Examples of the acidic functional group include a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a sulfuric acid group (—OSO ₃ H), a phosphonic acid group (—PO (OH) ₃ ), and a phosphoric acid group (—OPO ( OH) ₃ ), a phosphinic acid group (—PO (OH) —), and a mercapto group (—SH).

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

Nonionic functional groups include hydroxy group, ether group, thioether group, sulfinyl group (—SO—), sulfonyl group (—SO ₂ —), carbonyl group, formyl group, ester group, carbonate group, amide group, Examples thereof include a carbamoyl group, a ureido group, a thioamide group, a thioureido group, a sulfamoyl group, a cyano group, an alkenyl group, an alkynyl group, a phosphine oxide group, and a phosphine sulfide group.

  From the viewpoint of dispersion stability of light-scattering particles, from the viewpoint of hardly causing the side effect that the luminescent nanocrystal particles settle, from the viewpoint of ease of synthesis of the polymer dispersant, and from the viewpoint of stability of the functional group, acidic functional As the group, a carboxyl group, a sulfo group, a phosphonic acid group, and a phosphoric acid group are preferably used, and as the 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.

  The polymer dispersant having an acidic functional group has 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 difficult to decrease.

The acid value of the polymer dispersant was prepared by preparing a sample solution prepared by dissolving the polymer dispersant pg in 50 mL of a mixed solution in which toluene and ethanol were mixed at a volume ratio of 1: 1 and 1 mL of phenolphthalein test solution. Titration with 1 mol / L ethanol-made 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 becomes light red. I do. The acid value can be calculated by the following formula.
Acid value = q × r × 5.661 / p
In the formula, q represents the titration (mL) of the 0.1 mol / L ethanol potassium hydroxide solution required for titration, and r represents the titer of the 0.1 mol / L ethanol potassium hydroxide solution required for titration. P represents the mass (g) of the polymer dispersant.

  The polymer dispersant having a basic functional group has 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 difficult to decrease.

The amine value of the polymer dispersant was prepared by preparing a sample solution prepared by dissolving the polymer dispersant xg in 50 ml of a mixed solution in which toluene and ethanol were mixed at a volume ratio of 1: 1 and 1 ml of bromophenol blue reagent solution. Titration is performed with 5 mol / L hydrochloric acid until the sample solution becomes green. Then, the amine value can be calculated by the following formula.
Amine number = y / x × 28.05
In the formula, y represents the titration amount (ml) of 0.5 mol / L hydrochloric acid required for titration, and x represents 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. 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 is, for example, acrylic resin, polyester resin, polyurethane resin, polyamide resin, polyether, phenol resin, silicone resin, polyurea resin, amino resin, epoxy resin, polyamine such as polyethylenimine and polyallylamine, polyimide, etc. It may be.

  Commercially available products can also be used as the polymer dispersant. Examples of the commercially available products include Ajinomoto Fine Techno Co., Ltd. Ajisper PB series, BYK's DISPERBYK series and BYK-series, BASF's Efka. Series etc. can be used.

  Commercially available products include, for example, “DISPERBYK-130”, “DISPERBYK-161”, “DISPERBYK-162”, “DISPERBYK-163”, “DISPERBYK-164”, “DISPERBYK-166”, “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”, “DISP” RBYK-2009 "," DISPERBYK-2020 "," DISPERBYK-2022 "," DISPERBYK-2025 "," DISPERBYK-2050 "," DISPERBYK-2070 "," DISPERBYK-2096 "," DISPERBYK-2150 "," DISPERBY " 2155 "," DISPERBYK-2163 "," DISPERBYK-2164 "," BYK-LPN21116 "and" BYK-LPN6919 ";" EFKA4010 "," EFKA4015 "," EFKA4046 "," EFKA4047 "," EFK "manufactured by BASF , “EFKA4080”, “EFKA4300”, “EFKA4310”, “EFKA4320”, “EFKA4330”, “EFK” "4340", "EFKA4560", "EFKA4585", "EFKA5207", "EFKA1501", "EFKA1502", "EFKA1503" and "EFKA PX-4701"; "Solsparse 3000", "Solsparse 9000", "Lubrisol" "Sol Sparse 13240", "Sol Sparse 13650", "Sol Sparse 13940", "Sol Sparse 11200", "Sol Sparse 13940", "Sol Sparse 16000", "Sol Sparse 17000", "Sol Sparse 18000", "Sol Sparse 20000", "Sol Sparse 21000", " "Sol Sparse 24000", "Sol Sparse 26000", "Sol Sparse 27000", "Sol Sparse 28000", "Sol Sparse 32000" “Sol Sparse 32500”, “Sol Sparse 32550”, “Sol Sparse 32600”, “Sol Sparse 33000”, “Sol Sparse 34750”, “Sol Sparse 35100”, “Sol Sparse 35200”, “Sol Sparse 36000”, “Sol Sparse 37500”, “Sol Sparse 38500”, “Solspers 39000”, “Solspers 41000”, “Solspers 54000”, “Solspers 71000” and “Solspers 76500”; “Ajispur PB821”, “Addisper PB822”, “Addisper PB881”, “PN411” manufactured by Ajinomoto Fine Techno Co. "And" PA111 ";" TEGO Dispers 650 "," TEGO Dispers 660C "," TEGO "manufactured by Evonik "ispers 662C", "TEGO Dispers 670", "TEGO Dispers 685", "TEGO Dispers 700", "TEGO Dispers 710" and "TEGO Dispers 760W"; "Disparon DA" 703-50, "manufactured by Enomoto Kasei 725 "or the like can be used.

  As the polymer dispersant, in addition to the above-mentioned commercially available products, 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 if necessary Those synthesized by copolymerizing (nonionic monomers, monomers having a hydrophilic group, etc.) can be used. As for details of the cationic monomer, the anionic monomer, the monomer having a hydrophobic group, and other monomers, there can be mentioned monomers described in paragraphs 0034 to 0036 of JP-A No. 2004-250502.

  Further, for example, a compound obtained by reacting a polyalkyleneimine and a polyester compound described in JP-A-54-37082, JP-A-61-174939, or the like, or 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 having a polyester type macromonomer described in JP-A-9-171253 as a copolymerization component, and a polyester polyol addition described in JP-A-60-166318 Preferred examples include polyurethane.

  The weight average molecular weight of the polymer dispersant may be 750 or more and 1000 or more from the viewpoint that the light scattering particles can be favorably dispersed and the effect of improving the external quantum efficiency can be further improved. It may be 2000 or more, or 3000 or more. The weight average molecular weight of the polymer dispersant can disperse the light-scattering particles well, can further improve the effect of improving the external quantum efficiency, and can discharge the viscosity of the inkjet ink for stable discharge. From the viewpoint of obtaining a suitable viscosity, it may be 100,000 or less, 50000 or less, or 30000 or less.

  From the viewpoint of 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, 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 wet heat stability of the pixel part (cured product of the ink composition). It may be 10 parts by mass or less.

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

  The boiling point of the solvent is preferably 180 ° C. or higher from the viewpoint of continuous ejection stability of the inkjet ink. Further, since it is necessary to remove the solvent from the ink composition before the ink composition is cured when the pixel portion is formed, the boiling point of the solvent is preferably 300 ° C. or less from the viewpoint of easy removal of the solvent.

  In the ink composition of the present embodiment, since the photopolymerizable compound also functions as a dispersion medium, it is possible to disperse the light-scattering particles and the light-emitting nanocrystal particles without a solvent. In this case, there is an advantage that a step of removing the solvent by drying is not necessary when forming the pixel portion.

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

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

  When the viscosity of the ink composition at 40 ° C. is 2 mPa · s or more, or the viscosity at 23 ° C. of the ink composition is 5 mPa · s or more, the meniscus shape of the inkjet ink at the tip of the ink discharge hole of the discharge head Therefore, inkjet ink ejection control (for example, control of ejection amount and ejection timing) is facilitated. On the other hand, when the viscosity at 40 ° C. of the ink composition is 20 mPa · s or less, or when the viscosity at 40 ° C. of the ink composition is 40 mPa · s or less, the inkjet ink is smoothly ejected from the ink ejection holes. Can do.

  The surface tension of the ink composition is preferably a surface tension suitable for an ink jet system, specifically, a range of 20 to 40 mN / m is preferable, and a range of 25 to 35 mN / m is more preferable. . By making the surface tension within this range, the occurrence of flight bending can be suppressed. Note that the flight bend means that when the ink composition is ejected from the ink ejection hole, the landing position of the ink composition deviates by 30 μm or more from the target position. When the surface tension is 40 mN / m or less, the meniscus shape at the tip of the ink discharge hole is stable, and thus the discharge control of the ink composition (for example, control of the discharge amount and discharge timing) becomes easy. On the other hand, when the surface tension is 20 mN / m or more, the occurrence of flight bending can be suppressed. That is, a pixel portion that is not accurately landed on the pixel portion formation region to be landed and is insufficiently filled with the ink composition, or a pixel portion formation region (or pixel portion) adjacent to the pixel portion formation region to be landed Thus, the ink composition does not land and the color reproducibility does not deteriorate.

  When the ink composition of this embodiment is used as an ink composition for an ink jet system, it is preferably applied to a piezo jet ink jet recording apparatus using a mechanical ejection mechanism using a piezoelectric element. In the piezo jet method, the ink composition is not instantaneously exposed to high temperatures during ejection, the luminescent nanocrystal particles are not easily altered, and the light emission characteristics as expected by the color filter pixel part (light conversion layer) Is easier to obtain.

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

  When the ink composition is used in a photographic system, first, the ink composition is applied onto a substrate, and when the ink composition contains a solvent, the ink composition is further dried to form a coating film. The coating film thus obtained is soluble in an alkali developer and is patterned by being treated with the alkali developer. At this time, since the alkali developer is mostly an aqueous solution from the viewpoint of easiness 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 luminescent property (for example, fluorescence) is impaired by moisture. For this reason, in the present embodiment, an inkjet method that does not require treatment with an alkaline developer (aqueous solution) is preferable.

  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 air, and time elapses. As the light-emitting nanocrystal particles (quantum dots and the like) emit light, the light-emitting property (for example, fluorescence) is impaired. From this point of view, in the present embodiment, the coating film of the ink composition is preferably insoluble in alkali. That is, the ink composition of the present embodiment is preferably an ink composition capable of forming an alkali-insoluble coating film. Such an ink composition can be obtained by using an alkali-insoluble photopolymerizable compound as the photopolymerizable compound. The coating film of the ink composition is insoluble in alkali. The amount of dissolution of the coating film of the ink composition 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 30% by mass or less. The dissolution amount of the coating film of the ink composition is preferably 10% by mass or less, more preferably 3% by mass or less. It should be noted that the ink composition is an ink composition capable of forming an alkali-insoluble coating film when it is applied to a substrate and then dried at 80 ° C. for 3 minutes when it contains a solvent. It can confirm by measuring the said dissolution amount of the coating film of thickness 1 micrometer obtained.

<Method for producing ink composition>
Next, a method for producing the ink composition of the above-described embodiment will be described. The method for producing an ink composition includes at least a step of mixing luminescent nanocrystal particles and an epoxy resin. For example, the ink composition can be obtained by mixing the components of the ink composition described above and performing a dispersion treatment.

  Below, the manufacturing method of the ink composition which further contains light-scattering particle | grains and a polymer dispersing agent is demonstrated as an example of the manufacturing method of an ink composition.

  The method for producing an ink composition includes, for example, a first step of preparing a dispersion of light scattering particles containing light scattering particles and a polymer dispersant, a dispersion of light scattering particles, and a light-emitting nanoparticle. A second step of mixing the crystal particles. In this method, the light scattering particle dispersion may further contain an epoxy resin, and in the second step, an epoxy resin may be further mixed. According to this method, the light scattering particles can be sufficiently dispersed. For this reason, it is possible to reduce the leakage light in the pixel portion and easily obtain an ink composition having excellent ejection stability.

  In the step of preparing a dispersion of light scattering particles, a dispersion of light scattering particles is prepared by mixing the light scattering particles, a polymer dispersant, and, in some cases, an epoxy resin, and performing a dispersion treatment. You can do it. The mixing and dispersing treatment may be performed using a dispersing device such as a bead mill, a paint conditioner, a planetary stirrer, or a jet mill. It is preferable to use a bead mill or a paint conditioner from the viewpoint of good dispersibility of the light scattering particles and easy adjustment of the average particle diameter of the light scattering particles to a desired range. By mixing the light-scattering particles and the polymer dispersant before mixing the light-emitting nanocrystal particles and the light-scattering particles, the light-scattering particles can be more sufficiently dispersed. Therefore, excellent ejection stability and excellent external quantum efficiency can be obtained more easily.

  The method for producing an ink composition may further include a step of preparing a dispersion of luminescent nanocrystal particles containing the luminescent nanocrystal particles and an epoxy resin before the second step. In this case, in the second step, the dispersion of light scattering particles and the dispersion of luminescent nanocrystal particles are mixed. In the step of preparing the luminescent nanocrystal particle dispersion, the luminescent nanocrystal particle dispersion may be prepared by mixing the luminescent nanocrystal particles and the photopolymerizable compound and performing a dispersion treatment. As the luminescent nanocrystal particles, luminescent nanocrystal particles having an organic ligand on the surface thereof may be used. That is, the luminescent nanocrystal particle dispersion may further contain an organic ligand. The mixing and dispersing treatment may be performed using a dispersing device such as a bead mill, a paint conditioner, a planetary stirrer, or a jet mill. It is preferable to use a bead mill, a paint conditioner or a jet mill from the viewpoint that the dispersibility of the luminescent nanocrystal particles becomes good and the average particle diameter of the luminescent nanocrystal particles can be easily adjusted to a desired range.

  According to this method, the luminescent nanocrystal particles can be sufficiently dispersed. For this reason, it is possible to reduce the leakage light in the pixel portion and easily obtain an ink composition having excellent ejection stability. In the step of preparing the dispersion of luminescent nanocrystal particles, the mixing and dispersing treatment of the luminescent nanocrystal particles and the epoxy resin is performed using the same dispersing device as the step of preparing the dispersion of light scattering particles. You can go.

  In this production method, luminescent nanocrystal particles, light scattering particles, photopolymerizable compounds, photopolymerization initiators, organic ligands and other components other than polymer dispersants (for example, sensitizers, solvents, etc.) are further added. It may be used. In this case, the other components may be contained in the light-emitting nanocrystal particle dispersion or in the light-scattering particle dispersion. Moreover, you may mix another component with the composition obtained by mixing a luminescent nanocrystal particle dispersion and a light-scattering particle dispersion.

<Light conversion layer and color filter>
Next, 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 are used for the same or corresponding elements, and duplicate descriptions are omitted.

  FIG. 1 is a schematic cross-sectional view of a color filter according to an embodiment. As shown in FIG. 1, the color filter 100 includes a 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 light conversion layer 30 includes, as the pixel unit 10, a first pixel unit 10a, a second pixel unit 10b, and a third pixel unit 10c. The first pixel unit 10a, the second pixel unit 10b, and the third pixel unit 10c are arranged in a lattice pattern so as to be repeated in this order. The light shielding unit 20 is provided between adjacent pixel units, that is, between the first pixel unit 10a and the second pixel unit 10b, between the second pixel unit 10b and the third pixel unit 10c, and third. The pixel portion 10c and the first pixel portion 10a are provided. 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 curing component. A hardening component is a hardened | cured material of an epoxy resin, and is specifically a hardened | cured material obtained by superposition | polymerization of an epoxy resin. That is, the first pixel unit 10a includes the first cured component 13a and the first light-emitting nanocrystal particles 11a and the first light-scattering particles 12a dispersed in the first cured component 13a. Including. Similarly, the second pixel portion 10b includes a second cured component 13b, second luminescent nanocrystal particles 11b and second light-scattering particles 12b dispersed in the second cured component 13b, respectively. including. In the first pixel portion 10a and the second pixel portion 10b, the first cured component 13a and the second cured component 13b may be the same or different, and the first light scattering particles 12a The second light scattering particles 12b may be the same or different.

  The first light-emitting nanocrystal particles 11a are red light-emitting nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having an emission peak wavelength in the range of 605 to 665 nm. That is, the first pixel unit 10a may be rephrased as a red pixel unit for converting blue light into red light. The second light-emitting nanocrystal particles 11b are green light-emitting nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having an emission peak wavelength in the range of 500 to 560 nm. That is, the second pixel unit 10b may be rephrased as a green pixel unit for converting blue light into green light.

  The content of the luminescent nanocrystal particles in the pixel portion including the cured product of the ink composition is the total mass of the cured product of the ink composition from the viewpoint of obtaining an excellent effect of improving the external quantum efficiency and obtaining an excellent emission intensity. Is preferably 5% by mass or more. From the same viewpoint, the content of the luminescent nanocrystal particles may be 10% by mass or more, 15% by mass or more, and 20% by mass based on the total mass of the cured product of the ink composition. % Or more. The content of the light-emitting nanocrystal particles is preferably 50% by mass or less based on the total mass of the cured product of the ink composition from the viewpoint of excellent reliability of the pixel portion and excellent emission intensity. . From the same viewpoint, the content of the luminescent nanocrystal particles may be 40% by mass or less, 35% by mass or less, or 30% by mass based on the total mass of the cured product of the ink composition. % Or less.

  The content of the light-scattering particles in the pixel portion including 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 being more effective in improving the external quantum efficiency. 1 mass% or more, 5 mass% or more, 7 mass% or more, 10 mass% or more, or 12 mass% or more. There may be. 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 external quantum efficiency improvement effect and excellent reliability of the pixel portion. 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less. 15 mass% or less may be sufficient.

  The third pixel portion 10c has a transmittance of 30% or more for light with a wavelength in the range of 420 to 480 nm. Therefore, the third pixel 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 3rd pixel part 10c contains the hardened | cured material of the composition containing the above-mentioned photopolymerizable compound, for example. The cured product contains a third curing component 13c. The 3rd hardening component 13c is a hardened | cured material of an epoxy resin, and is specifically a hardened | cured material obtained by superposition | polymerization of an epoxy resin. That is, the third pixel portion 10c includes the third curing component 13c. When the third pixel portion 10c includes the above-described cured product, the composition containing an epoxy resin has the above-described ink composition as long as the transmittance with respect to light having a wavelength in the range of 420 to 480 nm is 30% or more. Among the components contained in, you may further contain components other than an epoxy resin. Note that the transmittance of the third pixel portion 10c can be measured by a microspectroscopic device.

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

  The light shielding unit 20 is a so-called black matrix provided for the purpose of preventing color mixture by separating adjacent pixel units and preventing light leakage from the light source. The material constituting the light-shielding part 20 is not particularly limited, and curing of a resin composition containing light-shielding particles such as carbon fine particles, metal oxides, inorganic pigments, organic pigments in a binder polymer in addition to a metal such as chromium. A thing etc. can be used. As the binder polymer used here, polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, cellulose, or a mixture of two or more resins, photosensitive resin, O / W An emulsion type resin composition (for example, an emulsion of reactive silicone) can be used. The thickness of the light shielding part 20 may be, for example, 0.5 μm or more and 10 μm or less.

  The base material 40 is a transparent base material having optical transparency. For example, the base material 40 is a transparent glass substrate such as quartz glass, Pyrex (registered trademark) glass, or a synthetic quartz plate, a transparent resin film, an optical resin film, or the like. A flexible base material etc. can be used. Among these, it is preferable to use the glass substrate which consists of an alkali free glass which does not contain an alkali component in glass. Specifically, “7059 glass”, “1737 glass”, “Eagle 200” and “Eagle XG” manufactured by Corning, “AN100” manufactured by Asahi Glass, “OA-10G” manufactured by Nippon Electric Glass, and “ OA-11 "is preferred. These are materials having a small coefficient of thermal expansion, and are excellent in dimensional stability and workability in high-temperature heat treatment.

  The color filter 100 including the above light conversion layer 30 is preferably used when a light source that emits light having a wavelength in the range of 420 to 480 nm is used.

  For example, the color filter 100 is formed by forming the light-shielding portion 20 on the base material 40 in a pattern, and then forming the ink composition (in the above-described embodiment) on the pixel portion forming region partitioned by the light-shielding portion 20 on the base material 40. Ink-jet ink) can be selectively deposited by an ink-jet method, and the ink composition can be cured by irradiation with active energy rays.

  The light shielding part 20 is formed by forming a metal thin film such as chromium or a resin composition thin film containing light shielding particles in a region serving as a boundary between a plurality of pixel parts on one side of the substrate 40. And a method of patterning the thin film. The metal thin film can be formed by, for example, a sputtering method, a vacuum deposition method, or the like, and the thin film of the resin composition containing the light-shielding particles can be formed by, for example, a method such as coating or printing. Examples of the patterning method include a photolithography method.

  Examples of the inkjet method include a bubble jet (registered trademark) method using an electrothermal transducer as an energy generating element, a piezo jet method using a piezoelectric element, and the like.

When the ink composition is cured by irradiation with active energy rays (for example, ultraviolet rays), for example, a mercury lamp, a metal halide lamp, a xenon lamp, an LED, or the like may be used. The wavelength of the irradiated light may be, for example, 200 nm or more and 440 nm or less. The exposure amount may be, for example, 10 mJ / cm ² or more and may be 4000 mJ / cm ² or less.

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

  As mentioned above, although one embodiment of the color filter, the light conversion layer, and the manufacturing method thereof has been described, the present invention is not limited to the above embodiment.

  For example, the light conversion layer may be a pixel portion including a cured product of an ink composition containing blue light-emitting nanocrystal particles instead of or in addition to the third pixel portion 10c. A blue pixel portion). The light conversion layer may include a pixel portion (for example, a yellow pixel portion) including 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, each of the luminescent nanocrystal particles contained in each pixel portion of the light conversion layer preferably has an absorption maximum wavelength in the same wavelength region.

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

  The color filter may include an ink repellent layer made of a material having an ink repellency narrower than that of the light shielding portion on the pattern of the light shielding portion. Also, instead of providing an ink repellent layer, a photocatalyst-containing layer as a wettability variable layer is formed in a solid shape in a region including the pixel portion formation region, and then light is passed through the photocatalyst-containing layer through a photomask. Exposure may be performed by irradiation to selectively increase the ink affinity of the pixel portion formation region. Examples of the photocatalyst include titanium oxide and zinc oxide.

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

  The color filter may include a protective layer on the pixel portion. This protective layer flattens the color filter and prevents elution of components contained in the pixel portion, or components contained in the pixel portion and components contained in the photocatalyst containing layer into the liquid crystal layer. It is provided. As the material constituting the protective layer, those used as known color filter protective layers can be used.

  In manufacturing the color filter and the light conversion layer, the pixel portion may be formed by a photolithography method instead of the ink jet method. In this case, first, the ink composition is applied to the base material in layers to form an ink composition layer. Next, the ink composition layer is exposed in a pattern and then developed using a developer. In this way, a pixel portion made of a cured product of the ink composition is formed. Since the developer is usually alkaline, an alkali-soluble material is used as the material of the ink composition. However, the ink jet method is superior to the photolithography method in terms of material use efficiency. This is because, in the photolithography method, approximately 2/3 or more of the material is removed in principle, and the material is wasted. For this reason, in this embodiment, it is preferable to form a pixel part by an inkjet system using inkjet ink.

  In addition to the above-described 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 blue light and emit light is used as the pixel portion of the liquid crystal display element, blue light or quasi-white light having a peak at 450 nm as light from the light source However, when the concentration of the luminescent nanocrystal particles in the pixel portion is not sufficient, light from the light source passes through the light conversion layer when the liquid crystal display element is driven. The transmitted light (blue light, leakage light) from this light source and the light emitted from the light-emitting nanocrystal particles are mixed. From the viewpoint of preventing the color reproducibility from being deteriorated due to the occurrence of such color mixing, a pigment may be contained in the pixel portion of the light conversion layer. In order to contain the pigment in the pixel portion, the ink composition may contain a pigment.

  In addition, one or two of the red pixel portion (R), the green pixel portion (G), and the blue pixel portion (B) in the light conversion layer of the present embodiment are formed as luminescent nanocrystal particles. It is good also as a pixel part which contained a coloring material without containing. A known color material can be used as the color material that can be used here. For example, the color material used for the red pixel portion (R) includes a diketopyrrolopyrrole pigment and / or an anionic red organic dye. Examples of the color 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 green dye, and a mixture of a phthalocyanine blue dye and an azo yellow organic dye. Examples of the color material used for the blue pixel portion (B) include an ε-type copper phthalocyanine pigment and / or a cationic blue organic dye. When used in the light conversion layer, these coloring materials are used in an amount of 1 to 5 masses based on the total mass of the pixel portion (cured product of the ink composition) from the viewpoint of preventing a decrease in transmittance. % Is preferred.

  Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited only to the following examples. Note that all the materials used in the examples were those in which argon gas was introduced and dissolved oxygen was replaced with argon gas. The titanium oxide used was heated at 120 ° C. for 2 hours under reduced pressure of 1 mmHg and allowed to cool in an argon gas atmosphere 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 Red Luminescent InP / ZnSeS / ZnS Nanocrystalline Particle Dispersion>
[Preparation of indium laurate solution]
10 g of 1-octadecene (ODE), 146 mg (0.5 mmol) of indium acetate and 300 mg (1.5 mmol) of lauric acid were added to the reaction flask to obtain a mixture. The mixture was heated at 140 ° C. for 2 hours under vacuum to obtain a transparent solution (indium laurate solution). This solution was kept in the glove box at room temperature until needed. Since indium laurate has low solubility at room temperature and tends to precipitate, when using an indium laurate solution, the precipitated indium laurate in the solution (ODE mixture) is heated to about 90 ° C. to be transparent. After forming the solution, the desired amount was weighed and used.

[Production of core of red light emitting nanocrystal particle (InP core)]
Trioctylphosphine oxide (TOPO) 5 g, indium acetate 1.46 g (5 mmol) and lauric acid 3.16 g (15.8 mmol) were added to the reaction flask to obtain a mixture. The mixture was heated at 160 ° C. for 40 minutes under a nitrogen (N ₂ ) environment, and then heated at 250 ° C. for 20 minutes under vacuum. Subsequently, the reaction temperature (temperature of the mixture) was raised to 300 ° C. under a nitrogen (N ₂ ) environment. At this temperature, a mixture of 3 g 1-octadecene (ODE) and 0.25 g (1 mmol) 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 resulting reaction solution was cooled to room temperature. Subsequently, 8 ml of toluene and 20 ml of ethanol were added to the reaction solution in the glove box. Subsequently, centrifugation was performed to precipitate InP nanocrystal particles, and then InP nanocrystal particles were obtained by decanting the supernatant. Next, the obtained InP nanocrystal particles were dispersed in hexane. This obtained the dispersion liquid (hexane dispersion liquid) containing 5 mass% of InP nanocrystal particles.

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

[Formation of Shell (ZnSeS / ZnS Shell) of Red Light-Emitting Nanocrystal Particles]
After adding 2.5 g of the hexane dispersion of InP nanocrystal particles (InP core) obtained above to the reaction flask, 0.7 g of oleic acid is added to the reaction flask at room temperature, and the temperature is raised to 80 ° C. For 2 hours. Next, 14 mg of diethylzinc dissolved in 1 ml of ODE, 8 mg of bis (trimethylsilyl) selenide and 7 mg of hexamethyldisilathiane (ZnSeS precursor solution) dissolved in 1 ml of ODE are dropped into this reaction mixture, heated to 200 ° C. and held for 10 minutes. As a result, a ZnSeS shell having a thickness of 0.5 monolayer was formed.

  The temperature was then raised to 140 ° C. and held for 30 minutes. Next, in this reaction mixture, a ZnS precursor solution obtained by dissolving 69 mg of diethylzinc and 66 mg of hexamethyldisilathiane in 2 ml of ODE was dropped, and the temperature was raised to 200 ° C. and held for 30 minutes, A 2 monolayer ZnS shell was formed. Ten minutes after the dropwise addition of the ZnS precursor solution, the reaction was stopped by removing the heater. Next, the reaction mixture is cooled to room temperature, and the resulting white precipitate is removed by centrifugation, whereby a transparent nanocrystal particle dispersion (InP / ZnSeS) in which red light-emitting InP / ZnSeS / ZnS nanocrystal particles are dispersed is obtained. / ODE dispersion of ZnS nanocrystal particles).

[Synthesis of organic ligands for InP / ZnSeS / ZnS nanocrystal particles]
(Synthesis of organic ligand A)
JEFAMINE M-1000 (manufactured by Huntsman) was charged into the flask, and then JEFAMINE M-1000 and an equimolar amount of succinic anhydride (manufactured by Sigma-Aldrich) were 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 (organic ligand A) represented by the following formula (A) as a pale yellow viscous oil.

(Synthesis of organic ligand B)
The synthesis was carried out with reference to the method disclosed in US Pat. No. 7718577. Polyethylene glycol (15 g, 20 mmol) (MW = 750) and sodium hydride (800 mg, 20 mmol) were mixed in a flask under a nitrogen atmosphere at room temperature, and dried THF (200 ml) was added thereto. The mixture was kept stirring until no hydrogen evolution was observed (approximately 20 minutes). Next, allyl bromide (1.7 ml, 20 mmol) was added dropwise to the above mixture using a syringe and stirred at room temperature for 3 hours. The mixture was centrifuged, the supernatant was taken out and the precipitate was removed. The supernatant was added dropwise to t-butyl methyl ether (800 ml) at 0 ° C. to precipitate a white solid. The white solid precipitate was filtered and vacuum dried to obtain 34 g of polyethylene glycol monoallyl ether.

［式中、ｒは１２〜２０の整数を示す。］ Under a nitrogen atmosphere, 1.5 g of mercaptosuccinic acid, 8 g of the above polyethylene glycol monoallyl ether, 0.1 g of ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate and 20 ml of toluene were added to a 40 ml glass vial. Light was irradiated for 1 minute with a metal halide lamp while the vial was oscillated intermittently (approximately 5000 mJ / cm ² ). An equal amount of hexane is added to the above mixture, and the mixture is centrifuged at 4000 rpm for 5 minutes. The supernatant is discarded, the precipitate is dried at room temperature in a vacuum environment, and a ligand represented by the following formula (B) (organic ligand) B) was obtained.

[Wherein, r represents an integer of 12 to 20. ]

[Preparation of red light-emitting InP / ZnSeS / ZnS nanocrystal particle dispersion by ligand exchange]
(Preparation of InP / ZnSeS / ZnS nanocrystal particles modified with organic ligand A)
30 mg of the organic ligand A was added to 1 ml of the ODE dispersion liquid of InP / ZnSeS / ZnS nanocrystal particles obtained above. Subsequently, ligand exchange was performed by heating at 90 ° C. for 5 hours. 6 ml of ethanol was added to 1 ml of the nanocrystal particle solution after ligand exchange. Subsequently, centrifugation was performed to precipitate the nanocrystal particles, and then nanocrystal particles (InP / ZnSeS / ZnS nanocrystal particles modified with the organic ligand A) were obtained by decanting the supernatant and drying under vacuum. . The content of organic ligand A in the total amount of nanocrystal particles modified with organic ligand A was 30% by mass. By dispersing the obtained nanocrystal particles in 1,4-BDDA (1,4-butanediol diacetate, manufactured by Daicel Corporation) so that the nonvolatile content is 40.9% by mass, red light-emitting nanocrystals are obtained. A particle dispersion 1 (1,4-BDDA dispersion) was obtained.

(Preparation of InP / ZnSeS / ZnS nanocrystal particles modified with organic ligand B))
A red light-emitting nanocrystal particle dispersion 2 (1,4-BDDA dispersion) was obtained in the same manner as in the case of the organic ligand A except that the organic ligand B was used in place of the organic ligand A.

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

[Synthesis of Shell (ZnSeS / ZnS Shell) of Green Luminescent Nanocrystal Particles]
After adding 2.5 g of the hexane dispersion of InP nanocrystal particles (InP core) obtained above to the reaction flask, 0.7 g of oleic acid is added to the reaction flask at room temperature, and the temperature is raised to 80 ° C. It was. Next, 14 mg of diethylzinc dissolved in 1 ml of ODE, 8 mg of bis (trimethylsilyl) selenide and 7 mg of hexamethyldisilanthane (ZnSeS precursor solution) were dropped into the reaction mixture to give a thickness of 0.5 monolayer. A ZnSeS shell was formed.

  After the dropwise addition of 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, in this reaction mixture, a ZnS precursor solution obtained by dissolving 69 mg of diethylzinc and 66 mg of hexamethyldisilathian in 2 ml of ODE was dropped to form a 2 monolayer ZnS shell. . Ten minutes after the dropwise addition of the ZnS precursor solution, the reaction was stopped by removing the heater. Next, the reaction mixture is cooled to room temperature, and the resulting white precipitate is removed by centrifugation, whereby a transparent nanocrystal particle dispersion liquid (ODE dispersion liquid) in which green light-emitting InP / ZnSeS / ZnS nanocrystal particles are dispersed is obtained. )

[Production of Green Luminescent InP / ZnSeS / ZnS Nanocrystalline Particle Dispersion by Ligand Exchange]
(Preparation of InP / ZnSeS / ZnS nanocrystal particles modified with organic ligand A)
30 mg of the organic ligand A was added to 1 ml of the ODE dispersion of nanocrystal particles obtained above. Subsequently, ligand exchange was performed by heating at 90 ° C. for 5 hours. 6 ml of ethanol was added to 1 ml of the nanocrystal particle solution after ligand exchange. Subsequently, centrifugation was performed to precipitate the nanocrystal particles, and then nanocrystal particles (InP / ZnSeS / ZnS nanocrystal particles modified with the organic ligand A) were obtained by decanting the supernatant and drying under vacuum. . The content of organic ligand A in the total amount of nanocrystal particles modified with organic ligand A was 30% by mass. By dispersing the obtained nanocrystal particles in 1,4-BDDA (1,4-butanediol diacetate, manufactured by Daicel Corporation) so that the nonvolatile content is 37.7% by mass, green light-emitting nanocrystals are obtained. A particle dispersion 1 (1,4-BDDA dispersion) was obtained.

(Preparation of InP / ZnSeS / ZnS nanocrystal particles modified with organic ligand B))
A green light emitting nanocrystal particle dispersion 2 (1,4-BDDA dispersion) is obtained in the same manner as in the case of using the organic ligand A except that the organic ligand B is used instead of the organic ligand A. It was.

<Preparation of light scattering particle dispersion>
In a container filled with argon gas, 33.0 g of titanium oxide (trade name: CR-60-2, manufactured by Ishihara Sangyo Co., Ltd., average particle diameter (volume average diameter): 210 nm) and a polymer dispersant ( 1.00 g and 1,4-BDDA (trade name: Ajisper PB-821, manufactured by Ajinomoto Fine Techno Co., Ltd.) were mixed to prepare a mixed solution having a nonvolatile content of 44%. After adding zirconia beads (diameter: 1.25 mm) to the mixture in the container filled with argon gas, the mixture is dispersed by shaking the sealed container filled with argon gas for 2 hours using a paint conditioner. Went. The light scattering particle dispersion 1 was obtained by removing the zirconia beads with a polyester mesh filter.

<Preparation of epoxy resin solution>
[Preparation of Epoxy Resin Solution 1]
0.933 g of epoxy resin EPICLON HM-091 (manufactured by DIC Corporation, epoxy equivalent: 2330) and 4-methylcyclohexane-1,2-dicarboxylic anhydride (4M-HHPA, Tokyo Chemical Industry) as a curing agent Co., Ltd.) (0.0670 g) and N, N-dimethylbenzylamine (Tokyo Chemical Industry Co., Ltd.) as a curing catalyst (0.010 g) with a nonvolatile content of 31.7% by mass, It was dissolved in 4-BDDA (1,4-butanediol diacetate, manufactured by Daicel Corporation) (solvent) to obtain 3.19 g of epoxy resin solution 1.

[Preparation of Epoxy Resin Solution 2]
0.739 g of EPICLON 1050 (made by DIC Corporation, bisphenol A type epoxy resin, epoxy equivalent: 475) as an epoxy resin and 4-methylcyclohexane-1,2-dicarboxylic anhydride (4M-HHPA) as a curing agent 0.261 g of Tokyo Chemical Industry Co., Ltd.) and 0.010 g of N, N-dimethylbenzylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing catalyst so that the nonvolatile content is 47.7% by mass. Then, it was dissolved in 1,4-BDDA (1,4-butanediol diacetate, manufactured by Daicel Corporation) (solvent) to obtain 2.12 g of epoxy resin solution 2.

[Preparation of Epoxy Resin Solution 3]
0.554 g of EPICLON N-865 (manufactured by DIC Corporation, phenol / modified novolac type epoxy resin, epoxy equivalent: 209), which is an epoxy resin, and 4-methylcyclohexane-1,2-dicarboxylic acid anhydride, which is a curing agent 0.44 g of 4M-HHPA (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.010 g of N, N-dimethylbenzylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), which is a curing catalyst, have a nonvolatile content of 54.8 mass. %, It was dissolved in 1,4-BDDA (1,4-butanediol diacetate, manufactured by Daicel Corporation) (solvent) to obtain 1.84 g of epoxy resin solution 3.

[Preparation of Epoxy Resin Solution 4]
0.458 g of EPICLON HP-4032D (manufactured by DIC Corporation, epoxy equivalent: 142) as an epoxy resin and 4-methylcyclohexane-1,2-dicarboxylic acid anhydride (4M-HHPA, Tokyo Chemical Industry) as a curing agent 0.542 g) and N, N-dimethylbenzylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.010 g as a curing catalyst, with a nonvolatile content of 59.5% by mass, 1.70 g of epoxy resin solution 4 was obtained by dissolving in 4-BDDA (1,4-butanediol diacetate, manufactured by Daicel Corporation) (solvent).

[Preparation of Epoxy Resin Solution 5]
Epoxy resin EPICLON HM-091 (DIC Corporation, epoxy equivalent: 2330) 0.957 g, curing agent PHENOLITE TD-2131 (DIC Corporation, novolak resin) 0.0428 g, curing catalyst Of 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) and 1,4-BDDA (1,4-butanedioldi) so that the nonvolatile content is 30.5% by mass. Acetate, manufactured by Daicel Corporation) (solvent) was obtained to obtain 3.31 g of epoxy resin solution 5.

[Preparation of Epoxy Resin Solution 6]
0.820 g of EPICLON 1050 (made by DIC Corporation, bisphenol A type epoxy resin, epoxy equivalent: 475) and 0.180 g of PHENOLITE TD-2131 (made by DIC Corporation, novolak resin) which is a curing agent. And 0.010 g of 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.), which is a curing catalyst, and 1,4-BDDA (1,4) so that the nonvolatile content is 40.2% by mass. -Butanediol diacetate (manufactured by Daicel Corporation) (solvent) was obtained to obtain 2.51 g of epoxy resin solution 6.

[Preparation of Epoxy Resin Solution 7]
EPICLON N-865 which is an epoxy resin (manufactured by DIC Corporation, phenol / modified novolac type epoxy resin, epoxy equivalent: 209) and 0.668 g of a curing agent, PHENOLITE TD-2131 (manufactured by DIC Corporation, novolac resin) 0.332 g and 0.010 g of 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing catalyst, 1,4-BDDA so that the nonvolatile content is 40.2% by mass. Dissolved in (1,4-butanediol diacetate, manufactured by Daicel Corporation) (solvent), 2.51 g of an epoxy resin solution 7 was obtained.

[Preparation of Epoxy Resin Solution 8]
0.577 g of epoxy resin EPICLON HP-4032D (DIC Corporation, epoxy equivalent: 142), 0.423 g of curing agent PHENOLITE TD-2131 (DIC Corporation, novolak resin), and curing catalyst Of 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) and 1,4-BDDA (1,4-butanedioldi) so that the nonvolatile content is 40.2% by mass. 2.51 g of epoxy resin solution 8 was obtained by dissolving in acetate (manufactured by Daicel Corporation) (solvent).

<Preparation of red ink composition (inkjet ink)>
[Example 1-1]
0.480 g of red light-emitting nanocrystal particle dispersion 1 (nonvolatile content 40.9% by mass), 0.180 g of light scattering particle dispersion 1 (nonvolatile content 40% by mass), and epoxy resin solution 1 (nonvolatile) 0.341 g) was mixed uniformly in a container filled with argon gas, and then the mixture was filtered with a filter having a pore size of 5 μm in a glove box. Furthermore, argon gas was introduced into a container containing the obtained filtrate, and the inside of the container was saturated with argon gas. Subsequently, the red ink composition (inkjet ink) of Example 1 was obtained by reducing the pressure and removing the argon gas. The content of the luminescent nanocrystal particles is 35% by mass based on the mass of the nonvolatile content of the ink composition, and the epoxy group amount (mol) per 1 g of the luminescent nanocrystal particles (QD) is shown in Table 1. It was as shown.

[Examples 1-2 to 1-4]
Red ink compositions of Examples 1-2 to 1-4 were obtained in the same manner as in Example 1 except that the epoxy resin solutions 2 to 4 were used in place of the epoxy resin solution 1. Table 1 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD).

[Example 1-5]
A red ink composition of Example 1-5 was obtained in the same manner as Example 1-2 except that the red light-emitting nanocrystal particle dispersion 2 was used instead of the red light-emitting nanocrystal particle dispersion 1. It was. Table 1 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD).

[Example 1-6]
A red ink composition of Example 1-6 was obtained in the same manner as Example 1-3, except that red light-emitting nanocrystal particle dispersion 2 was used instead of red light-emitting nanocrystal particle dispersion 1. It was. Table 1 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD).

[Comparative Example 1-1]
0.480 g of red luminescent nanocrystal particle dispersion 1 (nonvolatile content 40.9 mass%), 0.180 g of light scattering particle dispersion 1 (nonvolatile content 40 mass%), and epoxy resin solution 4 (nonvolatile) After mixing uniformly in a container filled with argon gas, the mixture was filtered with a filter having a pore size of 5 μm in a glove box. Furthermore, argon gas was introduced into a container containing the obtained filtrate, and the inside of the container was saturated with argon gas. Subsequently, the red ink composition (inkjet ink) of Comparative Example 1-1 was obtained by reducing the pressure and removing the argon gas. The content of the luminescent nanocrystal particles is 35% by mass based on the mass of the nonvolatile content of the ink composition, and the epoxy group amount (mol) per 1 g of the luminescent nanocrystal particles (QD) is shown in Table 1. It was as shown.

<Evaluation>
[Preparation of sample for evaluation]
Each ink composition was applied on the glass substrate in the air with a spin coater so that the film thickness after drying was 5 μm. The coating film was cured by heating at 180 ° C. in a nitrogen atmosphere to form a layer (light conversion layer) made of a cured product of the ink composition on a glass substrate. Thereby, each sample for evaluation which is a substrate which has a light conversion layer was produced.

[External quantum efficiency (EQE) evaluation]
A blue LED (peak emission wavelength: 450 nm) manufactured by CCS Co., Ltd. was used as a surface light source. The measuring device was an integrating sphere connected to a radiation spectrophotometer (trade name “MCPD-9800”) manufactured by Otsuka Electronics Co., Ltd., and the integrating sphere was installed above the blue LED. The prepared sample for evaluation was inserted between the blue LED and the integrating sphere, and the spectrum observed by turning on the blue LED and the illuminance at each wavelength were measured.

From the spectrum and illuminance measured by the above measuring apparatus, the external quantum efficiency was determined as follows. The results are shown in Table 1. The external quantum efficiency is a value indicating how much of the light (photons) incident on the light conversion layer is emitted as fluorescence to the observer side. Therefore, if this value is large, it indicates that the light conversion layer is excellent in light emission characteristics, which is an important evaluation index.
Red EQE (%) = P1 (Red) / E (Blue) × 100
Green EQE (%) = P2 (Green) / E (Blue) × 100

Here, E (Blue), P1 (Red), and P2 (Grenn) represent the following, respectively.
E (Blue): represents the total value of “illuminance × wavelength ÷ hc” in the wavelength range of 380 to 490 nm.
P1 (Red): represents the total value of “illuminance × wavelength ÷ hc” in the wavelength range of 590 to 780 nm.
P2 (Green): represents the total value of “illuminance × wavelength ÷ hc” in the wavelength range of 500 to 650 nm.
These are values corresponding to the number of observed photons. Note that h represents a Planck constant and c represents the speed of light.

The EQE measured immediately after the sample for evaluation was made the initial external quantum efficiency (EQE ₀ ). After measuring EQE ₀ , the sample for evaluation was heated at 180 ° C. for 1 hour, and then the measured external quantum was measured. Let efficiency be EQE _h . When the value of EQE ₀ is excellent, it can be said that the ink composition can form a color filter pixel portion having excellent external quantum efficiency. In addition to EQE ₀ , it is desirable that the ink composition is further excellent in EQE _h . When the amount of epoxy group is 0.0040 mol / QD or less, EQE ₀ is improved. By using an epoxy resin having an epoxy equivalent of 195 g / eq or more, EQE ₀ is further improved. Changing the ligand from A to B improves the EQE _h .

<Preparation and Evaluation of Green Ink Composition>
[Examples 2-1 to 2-4 and Comparative Example 2-1]
Instead of the red luminescent nanocrystal particle dispersion 1, the same procedure as in Example 1-1 to 1-4 and Comparative Example 1-1 except that the green luminescent nanocrystal particle dispersion 1 was used. Examples 2-1 to 2-4 and Comparative Example 2-1 were obtained. Table 2 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD). The obtained green ink composition was evaluated in the same manner as in Example 1-1. The results are shown in Table 2.

[Example 2-5 and Example 2-6]
Example 2 was the same as Example 2-2 and Example 2-3 except that the green luminescent nanocrystal particle dispersion 2 was used instead of the green luminescent nanocrystal particle dispersion 1. 5. Example 2-6 was obtained. Table 2 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD). The obtained green ink composition was evaluated in the same manner as in Example 1-1. The results are shown in Table 2. When the amount of epoxy group is 0.0040 mol / QD or less, EQE ₀ is improved. By using an epoxy resin having an epoxy equivalent of 195 g / eq or more, EQE ₀ is further improved. Changing the ligand from A to B improves the EQE _h .

<Preparation of red ink composition>
[Example 3-1]
0.480 g of red light-emitting nanocrystal particle dispersion 1 (nonvolatile content 40.9% by mass), 0.180 g of light scattering particle dispersion 1 (nonvolatile content 40% by mass), and epoxy resin solution 5 (nonvolatile) (Minute concentration 30.5% by mass) and 0.354 g were uniformly mixed in a container filled with argon gas, and the mixture was filtered with a filter having a pore size of 5 μm in a glove box. Furthermore, argon gas was introduced into a container containing the obtained filtrate, and the inside of the container was saturated with argon gas. Subsequently, the red ink composition (inkjet ink) of Example 1 was obtained by reducing the pressure and removing the argon gas. The content of the luminescent nanocrystal particles is 35% by mass based on the mass of the nonvolatile content of the ink composition, and the epoxy group amount (mol) per gram of the luminescent nanocrystal particles (QD) is shown in Table 3. It was as shown.

[Examples 3-2 to 3-4 and Comparative Example 3-1]
Red ink compositions of Examples 1-2 to 1-4 were obtained in the same manner as in Example 1 except that the epoxy resin solutions 6 to 8 were used in place of the epoxy resin solution 5. Table 3 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD).

[Example 3-5]
A red ink composition of Example 3-5 was obtained in the same manner as Example 3-2 except that red light emitting nanocrystal particle dispersion 2 was used instead of red light emitting nanocrystal particle dispersion 1. It was. Table 1 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD).

[Example 3-6]
A red ink composition of Example 3-6 was obtained in the same manner as Example 3-3 except that red light emitting nanocrystal particle dispersion 2 was used instead of red light emitting nanocrystal particle dispersion 1. It was. Table 1 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD).

<Evaluation>
The external quantum efficiency of the ink compositions of Examples 3-1 to 3-6 and Comparative Example 3-1 was evaluated in the same manner as in Example 1-1. The results are shown in Table 3. When the amount of epoxy group is 0.0040 mol / QD or less, EQE ₀ is improved. By using an epoxy resin having an epoxy equivalent of 195 g / eq or more, EQE ₀ is further improved. Changing the ligand from A to B improves the EQE _h .

<Preparation and Evaluation of Green Ink Composition>
[Examples 4-1 to 4-4 and Comparative Example 4-1]
Instead of the red light-emitting nanocrystal particle dispersion 1, the same procedure as in Examples 3-1 to 3-4 and Comparative Example 3-1, except that the green light-emitting nanocrystal particle dispersion 1 was used. Examples 4-1 to 4-4 and Comparative Example 4-1 were obtained. Table 4 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD). The obtained green ink composition was evaluated in the same manner as in Example 1-1. The results are shown in Table 4.

[Example 4-5 and Example 4-6]
Example 4-2 and Example 4-3 were used in the same manner as in Example 4-2 except that green luminescent nanocrystal particle dispersion 2 was used instead of green luminescent nanocrystal particle dispersion 1. 5. Example 4-6 was obtained. Table 2 shows the amount of epoxy groups (mol) per gram of luminescent nanocrystal particles (QD). The obtained green ink composition was evaluated in the same manner as in Example 1-1. When the amount of epoxy group is 0.0040 mol / QD or less, EQE ₀ is improved. By using an epoxy resin having an epoxy equivalent of 195 g / eq or more, EQE ₀ is further improved. Changing the ligand from A to B improves the EQE _h .

The EQE _h is improved by changing the curing agent from TD-2131, which is a phenolic compound, to 4M-HHPA, which is an acid anhydride.

DESCRIPTION OF SYMBOLS 10 ... Pixel part, 10a ... 1st pixel part, 10b ... 2nd pixel part, 10c ... 3rd pixel part, 11a ... 1st luminescent nanocrystal particle, 11b ... 2nd luminescent nanocrystal particle , 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 (18)

Containing luminescent nanocrystal particles and an epoxy resin,
The ink composition wherein the epoxy group amount of the epoxy resin is 0.0040 mol or less per 1 g of the light-emitting nanocrystal particles.   The ink composition according to claim 1, wherein an epoxy equivalent of the epoxy resin is 195 eq / g or more, and the epoxy resin has two or more epoxy groups in one molecule. Further containing an organic ligand,
The organic ligand has a main chain containing a polyoxyalkylene group and at least one functional group capable of binding to the light-emitting nanocrystal particle at at least one end of the main chain. The ink composition as described.   The organic ligand has at least one first functional group capable of binding to the luminescent nanocrystal particle at one end of the main chain, and the first functional group at the other end of the main chain. The ink composition according to claim 3, which has different second functional groups.   The ink composition according to claim 4, wherein the first functional group is a carboxyl group, the second functional group is a hydroxyl group, and the organic ligand has two or more of the first functional groups. object.   The ink composition according to any one of claims 1 to 5, further comprising at least one curing agent selected from the group consisting of acid anhydrides and phenolic compounds.   The ink composition according to any one of claims 1 to 6, further comprising light scattering particles.   The ink composition according to claim 1, wherein the epoxy resin is alkali-insoluble.   The ink composition according to any one of claims 1 to 8, which is capable of forming an alkali-insoluble coating film.   The ink composition according to claim 1, wherein the surface tension is 20 to 40 mN / m.   The ink composition according to any one of claims 1 to 10, wherein the viscosity at 25 ° C is 2 to 20 mPa · s.   The ink composition according to any one of claims 1 to 11, further comprising a solvent having a boiling point of 180 ° C or higher.   The ink composition according to any one of claims 1 to 12, which is used for a color filter.   The ink composition according to any one of claims 1 to 13, which is used in an inkjet method. A light conversion layer comprising a plurality of pixel portions,
The plurality of pixel portions are light conversion layers having pixel portions including a cured product of the ink composition according to any one of claims 1 to 14. A light shielding part provided between the plurality of pixel parts;
The plurality of pixel portions are
The light-emitting nanocrystal particles containing the cured product and containing the light-emitting nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having an emission peak wavelength in the range of 605 to 665 nm are included. A first pixel portion;
The light-emitting nanocrystal particles containing the cured product and containing the light-emitting nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a light emission peak wavelength in the range of 500 to 560 nm. A second pixel portion;
The light conversion layer according to claim 15, comprising:   The light conversion layer according to claim 15, wherein the plurality of pixel portions further include a third pixel portion having a transmittance of 30% or more for light having a wavelength in a range of 420 to 480 nm.   A color filter provided with the light conversion layer as described in any one of Claims 15-17.

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