JP2022044970A - Ink composition, cured material, light conversion layer, and color filter - Google Patents

Abstract

To suppress an increase in viscosity of an ink composition due to an organic ligand.SOLUTION: An ink composition includes: luminescent nanocrystal particles; organic ligands capable of being bonded to surfaces of the luminescent nanocrystal particles; and photopolymerizable compounds. The organic ligand has two or more carbon-carbon double bonds.SELECTED DRAWING: None

Description

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

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

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

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

Japanese Unexamined Patent Publication No. 2020-21033

By the way, as disclosed in Patent Document 1, as a means for satisfactorily dispersing luminescent nanocrystal particles in an ink composition, an organic ligand capable of binding (coordinating) to the surface of luminescent nanocrystal particles. Is known to be used. However, according to the studies by the present inventors, there are restrictions on the type of organic ligand in order to suitably bind the organic ligand to the surface of the luminescent nanocrystal particles, but under the restriction, the organic ligand is restricted. The viscosity of the ink composition tends to increase due to the above. In particular, although the organic ligand containing the (poly) alkyleneoxy group described in Patent Document 1 is widely used, it tends to increase the viscosity of the ink composition. Increasing the viscosity of the ink composition is not desirable, especially when the light conversion layer is formed by an inkjet method.

Therefore, one aspect of the present invention is to suppress an increase in viscosity of an ink composition caused by an organic ligand.

According to the studies by the present inventors, it has been found that the increase in viscosity of the ink composition caused by the organic ligand can be suppressed by using the organic ligand having two or more carbon-carbon double bonds.

One aspect of the present invention comprises luminescent nanocrystal particles, an organic ligand capable of binding to the surface of the luminescent nanocrystal particles, and a photopolymerizable compound, wherein the organic ligand is two or more carbon-carbons. An ink composition comprising an organic ligand having a double bond.

The content of the organic ligand having two or more carbon-carbon double bonds may be 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the luminescent nanocrystal particles. An organic ligand having two or more carbon-carbon double bonds may further have a carboxyl group.

The ink composition may be used to form an optical conversion layer by an inkjet method.

Another aspect of the present invention is a cured product of the above ink composition.

Another aspect of the present invention includes a plurality of pixel portions and a light-shielding portion provided between the plurality of pixel portions, and the plurality of pixel portions are luminescent including a cured product of the above ink composition. It is an optical conversion layer having a pixel portion.

The light conversion layer contains, as a light emitting pixel portion, light emitting nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a light emitting peak wavelength in the range of 605 to 665 nm. The sex pixel portion and the second luminescent pixel portion containing luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a emission peak wavelength in the range of 500 to 560 nm. You may be prepared.

Another aspect of the present invention is a color filter including the above-mentioned optical conversion layer.

According to one aspect of the present invention, the increase in viscosity of the ink composition caused by the organic ligand can be suppressed.

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. As used herein, the term "cured product of an ink composition" is obtained by curing a curable component in an ink composition (in the case where the ink composition contains a solvent component, the ink composition after drying). Is. Therefore, it is preferable that the cured product of the ink composition does not contain an organic solvent, but a part of the organic solvent that has not been completely dried may remain. Further, in the present specification, the “nonvolatile component of the ink composition” means a component other than the organic solvent contained in the ink composition. That is, the "non-volatile component of the ink composition" may be paraphrased as a pre-cured component to be contained in the cured product of the ink composition.

<Ink composition>
The ink composition of one embodiment contains luminescent nanocrystal particles, an organic ligand, and a photopolymerizable compound.

The ink composition is, for example, an ink composition for forming an optical conversion layer (for example, for forming a color filter pixel portion) used for forming an optical conversion layer (pixel portion of the optical conversion layer) of a color filter or the like. It is a thing. This ink composition is, in one embodiment, a composition (inkjet ink) used in an inkjet method. The ink composition of one embodiment is different from that for a photolithography method in that a pixel portion (optical conversion layer) can be formed without wasting expensive luminescent nanocrystal particles, an inkjet head, and the like. It can contribute to finishing the inkjet method into a low-cost process. Hereinafter, embodiments of the ink composition will be described by taking as an example an ink composition used for forming an optical conversion layer by an inkjet method.

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

The luminescent nanocrystal particles can emit light (fluorescence or phosphorescence) having a wavelength different from the absorbed wavelength, for example, by absorbing light having a predetermined wavelength. The luminescent nanocrystal particles may be red luminescent nanocrystal particles (red luminescent nanocrystal particles) that emit light (red light) having a emission peak wavelength in the range of 605 to 665 nm, and may be 500 to 560 nm. It may be green light emitting nanocrystal particles (green light emitting nanocrystal particles) that emit light having an emission peak wavelength in the range (green light), and light having an emission peak wavelength in the range of 420 to 480 nm (blue light). ) May be emitted by blue light emitting nanocrystal particles (blue light emitting nanocrystal particles). In this embodiment, it is preferable that the ink composition contains at least one of these luminescent nanocrystal particles. The light absorbed by the luminescent nanocrystal particles is, for example, light having a wavelength in the range of 400 nm or more and less than 500 nm (particularly, light having a wavelength in the range of 420 to 480 nm) (blue light) or light in the range of 200 nm to 400 nm. It may be light of the wavelength of (ultraviolet light). The emission peak wavelength of the luminescent nanocrystal particles can be confirmed, for example, in the fluorescence spectrum or the phosphorescence spectrum measured by using a spectrofluorometer.

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

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

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

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

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

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

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

Specific semiconductor materials include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeDZn. CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSeTe, CdHgSeTe, AlHgSe InP, InAs, InSb, COLP, PLGAs, VMwareSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSe, PbSnPbSn SnPbSTe; Si, Ge, SiC, SiGe, AgInSe ₂ , CuGaSe ₂ , CuInS ₂ , CuGaS ₂ , CuInSe ₂ , AgInS ₂ , AgGaSe ₂ , AgGaS ₂ , C, Si and Ge. CdS, CdSe, CdTe, ZnS, from the viewpoint that the emission spectrum of luminescent semiconductor nanocrystal particles can be easily controlled, reliability can be ensured, production cost can be reduced, and mass productivity can be improved. ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS ₂ , AgInSe ₂ , AgInTe ₂ , AgGaS ₂ , _{AgGaSe 2} , _AgGaS2 , AgGaSe ₂ , _AgGaS2 , CuGaS ₂ , CuGaSe ₂ , CuGaTe ₂ , Si, C, Ge and Cu ₂ ZnSnS ₄ preferably comprises at least one selected from the group.

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

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

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

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

The shape of the luminescent nanocrystal particles is not particularly limited, and may be any geometric shape or any irregular shape. The shape of the luminescent nanocrystal particles may be, for example, spherical, ellipsoidal, pyramidal, disc-shaped, branched, net-shaped, rod-shaped, or the like. However, as the luminescent nanocrystal particles, using particles having less directionality as the particle shape (for example, particles having a spherical shape, a regular tetrahedron shape, etc.) can further improve the uniformity and fluidity of the ink composition. Is preferable.

The average particle size (volume average diameter) of the luminescent nanocrystal particles may be 1 nm or more, and may be 1.5 nm, from the viewpoint of easily obtaining light emission of a desired wavelength and from the viewpoint of excellent dispersibility and storage stability. It may be more than 2 nm and may be 2 nm or more. From the viewpoint that a desired emission wavelength can be easily obtained, it may be 40 nm or less, 30 nm or less, or 20 nm or less. The average particle diameter (volume average diameter) of the luminescent nanocrystal particles is obtained by measuring with a transmission electron microscope or a scanning electron microscope and calculating the volume average diameter.

As the luminescent nanocrystal particles, those dispersed in a colloidal form in an organic solvent, a photopolymerizable compound, or the like can be used. The surface of the luminescent nanocrystal particles dispersed in the organic solvent is preferably passivated by the above-mentioned organic ligand. As the organic solvent, the organic solvent described later contained in the ink composition is used.

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

The content of the luminescent nanocrystal particles is 20 parts by mass or more with respect to 100 parts by mass of the non-volatile content of the ink composition from the viewpoint of improving the external quantum efficiency of the pixel part, and the same effect can be further obtained. From the viewpoint of facilitating the use, it is preferably 23 parts by mass or more, more preferably 25 parts by mass or more, and further preferably 30 parts by mass or more. It is noteworthy that the present invention can exhibit excellent compatibility with the inkjet process while increasing the content of luminescent nanocrystal particles. On the other hand, the content of the luminescent nanocrystal particles is preferably 50 parts by mass with respect to 100 parts by mass of the non-volatile content of the ink composition from the viewpoint of further improving ejection stability and external quantum efficiency of the pixel portion. Hereinafter, it is 45 parts by mass or less, or 40 parts by mass or less. In the present specification, the content of the luminescent nanocrystal particles means the content of the luminescent nanocrystal particles themselves alone, and even when the luminescent nanocrystal particles have an organic ligand, the content of the organic ligand is contained. Does not include quantity.

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

[Organic ligand]
The organic ligand is an organic ligand that can bind to the surface of luminescent nanocrystal particles. The organic ligand may be coordinate-bonded to, for example, the surface of the luminescent nanocrystal particles. In other words, the surface of the luminescent nanocrystal particles may be passivated by an organic ligand. The ink composition comprises, for example, an organic ligand that is coordinate-bonded to the surface of the luminescent nanocrystal particles and an organic ligand that is not coordinate-bonded (eg, free) to the surface of the luminescent nanocrystal particles. May include.

The organic ligand includes one or more organic ligands having two or more carbon-carbon double bonds (hereinafter also referred to as "organic ligand A"). The number of carbon-carbon double bonds in the organic ligand A is preferably 3 or more, preferably 6 or less, 5 or less, or 4 or less. Especially, it is preferable that the number is three.

The organic ligand A preferably further has a carboxyl group. The number of carboxyl groups in the organic ligand A may be one or two or more, preferably one.

The organic ligand A may be an unsaturated fatty acid having two or more carbon-carbon double bonds (unsaturated bonds) and one carboxyl group in one embodiment. Examples of unsaturated fatty acids (diunsaturated fatty acids) having two carbon-carbon double bonds (unsaturated bonds) include linoleic acid, eikosazienoic acid, and docosadienoic acid. Examples of unsaturated fatty acids (triunsaturated fatty acids) having three carbon-carbon double bonds (unsaturated bonds) include α-linolenic acid, γ-linolenic acid, pinolenic acid, α-eleostearic acid, and β-. Examples thereof include eleostearic acid, medoic acid, dihomo-γ-linolenic acid, and eicosatrienic acid. Examples of unsaturated fatty acids (tetra-unsaturated fatty acids) having four carbon-carbon double bonds (unsaturated bonds) include stearidonic acid, arachidonic acid, eicosatetraenoic acid, and adrenic acid. Examples of unsaturated fatty acids (penta-unsaturated fatty acids) having five carbon-carbon double bonds (unsaturated bonds) include boseopentaenoic acid, eikosapentaenoic acid, osbondic acid, sardine acid, tetracosapentaenoic acid and the like. .. Examples of unsaturated fatty acids (hexa-unsaturated fatty acids) having six carbon-carbon double bonds (unsaturated bonds) include docosahexaenoic acid and heric acid.

The content of the organic ligand A is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 3 parts by mass or more, from the viewpoint of improving the compatibility with the polymerizable compound with respect to 100 parts by mass of the luminescent nanocrystal particles. Is 5 parts by mass or more, particularly preferably 7 parts by mass or more. The content of the organic ligand A is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 25 parts by mass or less, from the viewpoint of further suppressing the increase in viscosity of the ink composition with respect to 100 parts by mass of the luminescent nanocrystal particles. Is 20 parts by mass or less, particularly preferably 15 parts by mass or less.

The organic ligand may further contain one or more of other organic ligands (hereinafter, also referred to as “organic ligand B”) in addition to the organic ligand A. The organic ligand B has at least one functional group selected from the group consisting of, for example, an amino group, a carboxyl group, a thiol group, a phosphoric acid group, a phosphonic acid group, a phosphin group, a phosphinoxide group, and an alkoxysilyl group. ing. The organic ligand B may further have one carbon-carbon double bond. In one embodiment, the organic ligand B may have a carboxyl group and one carbon-carbon double bond, and may have one carboxyl group and one carbon-carbon double bond. You can do it.

Examples of the organic ligand B include caproic acid, lauric acid, oleic acid, oleylamine, dodecanethiol, n-trioctylphosphine, n-trioctylphosphine oxide and the like.

The content of the organic ligand B is preferably 3 parts by mass or more, more preferably 5 with respect to 100 parts by mass of the luminescent nanocrystal particles, from the viewpoint of dispersion stability of the luminescent nanocrystal particles and maintenance of luminescence characteristics. It is 7 parts by mass or more, more preferably 7 parts by mass or more, and particularly preferably 10 parts by mass or more. The content of the organic ligand B is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 40 parts by mass or less, from the viewpoint of further suppressing the increase in viscosity of the ink composition with respect to 100 parts by mass of the luminescent nanocrystal particles. Is 30 parts by mass or less, particularly preferably 25 parts by mass or less.

When the organic ligand contains the organic ligand A and the organic ligand B, the total content of the organic ligand is the viewpoint of the dispersion stability of the luminescent nanocrystal particles and the maintenance of the luminescence characteristics with respect to 100 parts by mass of the luminescent nanocrystal particles. From the viewpoint, it may be 15 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, or 40 parts by mass or more, and from the viewpoint of further suppressing an increase in viscosity of the ink composition. , 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less.

[Photopolymerizable compound]
The photopolymerizable compound is a compound that polymerizes by irradiation with light, and may be, for example, a photoradical polymerizable compound. The photopolymerizable compound may be a photopolymerizable monomer or oligomer. The photopolymerizable compound is used with a photopolymerization initiator. The photoradical polymerizable compound is used together with a photoradical polymerization initiator. In other words, the ink composition may contain a photopolymerizable component containing a photopolymerizable compound and a photopolymerization initiator, and may contain a photoradical polymerizable component containing a photoradical polymerizable compound and a photoradical polymerization initiator. You may be doing it. The ink composition may contain one kind of photopolymerizable compound, two or more kinds, and preferably two or more kinds.

Examples of the photoradical polymerizable compound include a monomer having an ethylenically unsaturated group (hereinafter, also referred to as “ethylenically unsaturated monomer”), a monomer having an isocyanate group, and the like. Here, the ethylenically unsaturated monomer means a monomer having an ethylenically unsaturated bond (carbon-carbon double bond). Examples of the ethylenically unsaturated monomer include a monomer having an ethylenically unsaturated group such as a vinyl group, a vinylene group, and a vinylidene group. Monomers having these groups may be referred to as "vinyl monomers".

The number of ethylenically unsaturated bonds (for example, the number of ethylenically unsaturated groups) in the ethylenically unsaturated monomer is, for example, 1 to 3. One type of ethylenically unsaturated monomer may be used alone, or a plurality of types may be used in combination. The photopolymerizable compound is a monomer having one ethylenically unsaturated group (single) from the viewpoint of facilitating both excellent ejection stability and excellent curability and further improving the external quantum efficiency. It may contain a (functional monomer) and a monomer having two or more ethylenically unsaturated groups (polyfunctional monomer), a monofunctional monomer, a monomer having two ethylenically unsaturated groups (bifunctional monomer), and ethylene. It may contain at least one selected from the group consisting of monomers having three sex unsaturated groups (trifunctional monomers).

The ethylenically unsaturated group may be a vinyl group, a vinylene group, a vinylidene group, a (meth) acryloyl group or the like, and is preferably a (meth) acryloyl group. In addition, in this specification, "(meth) acryloyl group" means "acryloyl group" and the corresponding "methacryloyl group". The same applies to the expressions "(meth) acrylate" and "(meth) acrylamide".

The photopolymerizable compound contains at least one compound having a (meth) acryloyl group as an ethylenically unsaturated group, and more preferably at least selected from the group consisting of (meth) acrylate and (meth) acrylamide. It contains at least one (meth) acrylate, more preferably at least one (meth) acrylate, and particularly preferably at least one (meth) acrylate having a linear alkyl group having 8 or more carbon atoms. The photopolymerizable compound preferably contains two or more (meth) acrylates from the viewpoint of facilitating both excellent ejection stability and excellent curability and further improving the external quantum efficiency. More preferably, a (meth) acrylate having one (meth) acryloyl group (monofunctional (meth) acrylate) and a (meth) acrylate having two or more (meth) acryloyl groups (polyfunctional (meth) acrylate). And more preferably, it has a monofunctional (meth) acrylate and a (meth) acrylate having two (meth) acryloyl groups (bifunctional (meth) acrylate) and three (meth) acryloyl groups (meth). Includes at least one selected from the group consisting of acrylates (trifunctional (meth) acrylates).

Examples of the monofunctional monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth). Acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) ) Acrylate, nonylphenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, butoxydiethylene glycol (Meta) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate , Tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, benzyl (meth) acrylate, phenylbenzyl (meth) acrylate, monosuccinate (2-acryloyloxyethyl), monosuccinate (2-methacryloyloxy) Ethyl), N- [2- (acryloyloxy) ethyl] phthalimide, N- [2- (acryloyloxy) ethyl] tetrahydrophthalimide, 4-hydroxybutyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, diacetone acrylamide, 4-acryloylmorpholine, N-tert-butylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, N-tert -Includes octylacrylamide, N-butoxymethylacrylamide, N-phenylacrylamide, N-dodecylacrylamide and the like.

Specific examples of the monomer having two ethylenically unsaturated groups (bifunctional monomer) include 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,5-pentane. Didioldi (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,8-octanediol Di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate ) Acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentylglycol hydroxypivalic acid ester diacrylate, tris (2-hydroxyethyl) ) Di (meth) acrylate in which the two hydroxyl groups of isocyanurate are substituted with a (meth) acryloyloxy group, and two diols obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol. The two hydroxyl groups of the diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of di (meth) acrylate and bisphenol A in which the hydroxyl groups of the above are substituted with (meth) acryloyloxy groups are (meth) acryloyloxy groups. Di (meth) acrylate substituted with (meth) Acryloyloxy group The two hydroxyl groups of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane are substituted with (meth) acryloyloxy group. Di (meth) acrylate, N, N'in which two hydroxyl groups of the diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of meth) acrylate and bisphenol A are substituted with (meth) acryloyloxy groups. -Methylene bisacrylamide, N, N'-ethylene bisacrylamide and the like can be mentioned.

Specific examples of the monomer having three ethylenically unsaturated groups (trifunctional monomer) include glycerin tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylicate, and EO-modified trimethylol. Examples thereof include propanetri (meth) acrylate.

The photopolymerizable compound preferably contains a polymerizable compound having a LogP value of 3.3 or less. In this case, the volatilization of the ink composition can be suppressed due to the high polarity (magnitude of intramolecular force) of the photopolymerizable compound. On the other hand, when the polarity of the photopolymerizable compound is high, the viscosity of the ink composition tends to increase. However, in the ink composition of the present embodiment, the polarity becomes higher due to the use of the above-mentioned organic ligand A. The increase in viscosity due to the highly polymerizable compound is suppressed.

The LogP value of the photopolymerizable compound can be calculated using general-purpose chemical structural formula drawing software (for example, ChemDraw). By drawing the chemical structure of the photopolymerizable compound for which the LogP value is to be calculated on the software and confirming the Chemical Properties on the software, the drawn LogP value of the photopolymerizable compound can be obtained.

The polymerizable compound having a LogP value of 3.3 or less is preferably phenoxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylicate, dicyclopentenyl (meth) acrylicate, or dicyclopentenyloxy. Ethyl (meth) acrylicate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, butoxydiethylene glycol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) Examples include acrylicate and EO-modified trimethylolpropane tri (meth) acrylate.

The polymerizable compound may further contain a photopolymerizable compound having a LogP value of more than 3.3 in addition to the photopolymerizable compound having a LogP value of 3.3 or less. The photopolymerizable compound having a LogP value of more than 3.3 is preferably dodecyl (meth) acrylate, octadecyl (meth) acrylate, isobornyl (meth) acrylate, and 1,9-nonanediol di (meth) acrylate. Can be mentioned.

The photopolymerizable compound may be alkali-insoluble from the viewpoint that a highly reliable pixel portion (cured product of the ink composition) can be easily obtained. In the present specification, the fact that the photopolymerizable compound is alkali-insoluble means that the amount of the photopolymerizable compound dissolved in 1% by mass of potassium hydroxide aqueous solution at 25 ° C. is 30 based on the total mass of the photopolymerizable compound. It means that it is less than mass%. The dissolved amount of the photopolymerizable compound is preferably 10% by mass or less, more preferably 3% by mass or less.

The content of the photopolymerizable compound is from the viewpoint that an appropriate viscosity can be easily obtained as an inkjet ink, from the viewpoint of improving the curability of the ink composition, and the solvent resistance of the pixel portion (cured product of the ink composition). From the viewpoint of improving wear resistance, the amount may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more with respect to 100 parts by mass of the non-volatile component of the ink composition. May be. The content of the photopolymerizable compound is 100, the mass of the non-volatile component of the ink composition, from the viewpoint that an appropriate viscosity can be easily obtained as an inkjet ink and from the viewpoint of obtaining more excellent optical characteristics (for example, external quantum efficiency). It may be 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less with respect to the mass part. There may be.

[Light scattering particles]
The ink composition may further contain light scattering particles. The light-scattering particles are, for example, optically inert inorganic particles. When the ink composition contains light-scattering particles, the light from the light source irradiated to the pixel portion can be scattered, so that excellent optical characteristics (for example, external quantum efficiency) can be obtained.

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

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

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

The content of the light-scattering particles is 0.1 part by mass or more, 1 part by mass or more, and 2 parts by mass with respect to 100 parts by mass of the non-volatile content of the ink composition from the viewpoint of being more excellent in the effect of improving the external quantum efficiency. It may be 10 parts or more, or 3 parts by mass or more. The content of the light-scattering particles is less than 10 parts by mass with respect to 100 parts by mass of the non-volatile content of the ink composition from the viewpoint of excellent compatibility with the inkjet process, optical properties and its reproducibility. From the viewpoint that the effect is more easily obtained, the amount may be 9 parts by mass or less, 7 parts by mass or less, or 5 parts by mass or less.

The mass ratio of the content of the light-scattering particles to the content of the luminescent nanocrystal particles (light-scattering particles / luminescent nanocrystal particles) is preferably 0.05 from the viewpoint of excellent effect of improving the external quantum efficiency. Above, 0.07 or more, 0.1 or more, 0.13 or more, or 0.15 or more. The mass ratio (light-scattering particles / luminescent nanocrystal particles) is preferably 0.2 or less, 0.19 or less from the viewpoint of further excellent compatibility with the inkjet process, optical properties, and reproducibility thereof. , 0.18 or less, 0.17 or less, or 0.16 or less.

The total amount of the luminescent nanocrystal particles and the light-scattering particles in the ink composition is preferably 100 parts by mass with respect to 100 parts by mass of the non-volatile component of the ink composition from the viewpoint that appropriate viscosity can be easily obtained as an inkjet ink. It is 20 parts by mass or more, more preferably 25 parts by mass or more, and further preferably 30 parts by mass or more. The total amount of the luminescent nanocrystal particles and the light-scattering particles in the ink composition is preferably 100 parts by mass with respect to 100 parts by mass of the non-volatile component of the ink composition from the viewpoint that appropriate viscosity can be easily obtained as an inkjet ink. It is 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less.

[Photopolymerization initiator]
The ink composition may further contain a photopolymerization initiator. The photopolymerization initiator is, for example, a photoradical polymerization initiator or a photocationic polymerization initiator. As the photoradical polymerization initiator, a molecular cleavage type or hydrogen abstraction type photoradical polymerization initiator is suitable.

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

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

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

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

[Polymer dispersant]
The ink composition may further contain a polymer dispersant. The polymer dispersant is a polymer compound having a weight average molecular weight of 750 or more and having a functional group having an affinity for light-scattering particles. The polymer dispersant has a function of dispersing light-scattering particles. The polymer dispersant is adsorbed on the light-scattering particles via a functional group having an affinity for the light-scattering particles, and the light-scattering particles are generated by electrostatic repulsion and / or steric repulsion between the polymer dispersants. Disperse in the ink composition. When the ink composition contains a polymer dispersant, the light-scattering particles can be satisfactorily dispersed even when the content of the light-scattering particles is relatively large (for example, when the content is about 60% by mass). can. The polymer dispersant is preferably bound to the surface of the light-scattering particles and adsorbed to the light-scattering particles, but is bound to the surface of the luminescent nanoparticles and adsorbed to the luminescent nanoparticles. It may be free in the ink composition.

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

The acidic functional groups include a carboxyl group (-COOH), a sulfo group (-SO ₃ H), a sulfate group (-OSO ₃ H), a phosphonic acid group (-PO (OH) ₃ ), and a phosphoric acid group (-OPO (-OPO)). OH) ₃ ), phosphinic acid group (-PO (OH)-), mercapto group (-SH), and the like.

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

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

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

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

[Organic solvent]
The ink composition may further contain an organic solvent. Examples of the organic 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 succinic acid. Examples thereof include diethyl, 1,4-butanediol diacetate, and glyceryl triacetate.

The boiling point of the organic solvent is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of continuous ejection stability of the inkjet ink. Further, since it is necessary to remove the solvent from the ink composition before curing the ink composition at the time of forming the pixel portion, the boiling point of the organic solvent is preferably 300 ° C. or lower from the viewpoint of easy removal of the organic solvent.

The organic solvent preferably contains an acetate compound having a boiling point of 150 ° C. or higher. In this case, the affinity between the luminescent nanocrystal particles and the solvent is improved, and the luminescent nanocrystal particles can exhibit excellent luminescence characteristics. Specific examples of the acetate compound having a boiling point of 150 ° C. or higher include monoacetate compounds such as diethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether acetate, and 1,4-butanediol di. Examples thereof include diacetate compounds such as acetate and propylene glycol diacetate, and triacetate compounds such as glyceryl triacetate.

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

The ink composition contains components other than the above-mentioned components (for example, thermosetting resin, curing agent, curing accelerator (curing catalyst), polymerization inhibitor, chain transfer agent, antioxidant) as long as the effects of the present invention are not impaired. Agents, etc.) may be further contained.

The viscosity of the ink composition described above at the ink temperature during inkjet printing may be, for example, 2 mPa · s or more, 5 mPa · s or more, or 7 mPa / s, from the viewpoint of ejection stability during inkjet printing. -It may be s or more. The viscosity of the ink composition at the ink temperature during inkjet printing may be 20 mPa · s or less, 15 mPa · s or less, or 12 mPa · s or less. In the present specification, the viscosity of the ink composition is, for example, the viscosity measured by an E-type viscometer, which is measured at 25 ° C.

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

The surface tension of the ink composition is preferably a surface tension suitable for the inkjet method, specifically, is preferably in the range of 20 to 40 mN / m, and more preferably 25 to 35 mN / m. .. By setting the surface tension within the range, discharge control (for example, control of discharge amount and discharge timing) can be facilitated, and the occurrence of flight bending can be suppressed. The flight bending means that when the ink composition is ejected from the ink ejection holes, the landing position of the ink composition deviates from the target position by 30 μm or more. When the surface tension is 40 mN / m or less, the meniscus shape at the tip of the ink ejection hole is stable, so that ejection control of the ink composition (for example, control of ejection amount and ejection timing) becomes easy. On the other hand, when the surface tension is 20 mN / m or more, it is possible to prevent the peripheral portion of the ink ejection hole from being contaminated with the inkjet ink, so that the occurrence of flight bending can be suppressed. That is, a pixel portion may not be accurately filled in the pixel portion forming region to be landed and the ink composition may be insufficiently filled, or a pixel portion forming region (or pixel portion) adjacent to the pixel portion forming region to be landed may be generated. The ink composition does not land on the surface and the color reproducibility does not deteriorate. The surface tension described in the present specification refers to the surface tension measured at 23 ° C., which is measured by the ring method (also referred to as the ring method).

When the ink composition of the present embodiment is used as an ink composition for an inkjet method, it is preferably applied to a piezojet type inkjet recording device having a mechanical ejection mechanism using a piezoelectric element. In the piezo jet method, the ink composition is not instantaneously exposed to a high temperature during ejection. Therefore, alteration of the luminescent nanocrystal particles is unlikely to occur, and it is easier to obtain the expected luminescence characteristics in the pixel portion (light conversion layer).

Although one embodiment of the inkjet ink composition has been described above, the inkjet ink composition of the above-described embodiment can be used, for example, by a photolithography method in addition to the inkjet method. In this case, the ink composition contains an alkali-soluble resin as the binder polymer.

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

Further, even when the coating film of the ink composition is not treated with an alkaline developer, if the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere. As time passes, the luminescence (for example, fluorescence) of luminescent nanocrystal particles (quantum dots, etc.) is impaired. From this point of view, in the present embodiment, the coating film of the ink composition is preferably alkali-insoluble. That is, the ink composition of the present embodiment is preferably an ink composition capable of forming an alkali-insoluble coating film. Such an ink composition can be obtained by using an alkali-insoluble photopolymerizable compound as the photopolymerizable compound. The fact that the coating film of the ink composition is alkaline insoluble means that the amount of the coating film of the ink composition dissolved at 25 ° C. in a 1% by mass potassium hydroxide aqueous solution is based on the total mass of the coating film of the ink composition. It means that it is 30% by mass or less. The dissolved amount of the coating film of the ink composition is preferably 10% by mass or less, more preferably 3% by mass or less. The fact that the ink composition is an ink composition capable of forming an alkali-insoluble coating film means that the thickness is obtained by applying the ink composition on a substrate and then drying it at 80 ° C. for 3 minutes. It can be confirmed by measuring the above-mentioned dissolution amount of the 1 μm coating film.

Another embodiment of the present invention is a cured product (cured film) of the ink composition, and it can be said that the cured product (cured film) of this ink composition is alkali-insoluble. As a result, it becomes easy to obtain a pixel portion having excellent reliability. The fact that the cured product of the ink composition is alkaline insoluble means that the amount of the cured product of the ink composition dissolved at 25 ° C. in 1% by mass of a potassium hydroxide aqueous solution is the total amount of the cured product of the ink composition, as described above. It means that it is 30% by mass or less based on the mass. The dissolved amount of the cured product of the ink composition is preferably 10% by mass or less, more preferably 3% by mass or less.

<Manufacturing method of ink composition>
The ink composition of the above-described embodiment includes, for example, a first step of preparing luminescent nanocrystal particles, a luminescent nanocrystal particle, an organic ligand A, and a photopolymerizable compound (and other components as required). ) Is manufactured by a manufacturing method comprising a second step of mixing.

In the first step, in one embodiment, luminescent nanocrystal particles having an organic ligand bonded to the surface are prepared. The organic ligand may be one or both of the above-mentioned organic ligand A and organic ligand B, and is preferably organic ligand B. The organic ligand can be attached to the surface of the luminescent nanocrystal particles by a known method. Alternatively, luminescent nanocrystal particles to which an organic ligand is bound can be purchased.

In the second step, all of the above components may be mixed at the same time. For example, the luminescent nanocrystal particles to which the organic ligand B is bound and the organic ligand A are first mixed, and then the remaining components are further mixed. It may be mixed. When substituting the dispersion medium from the solvent to the monomer, the solvent of the luminescent nanocrystalline particle dispersion to which the organic ligand B is bound is removed by a method such as drying or decantation, and the organic ligand A and the necessary monomer are added thereto. After addition, the organic solvent is removed by a method of redispersion, or by adding the organic ligand A and the necessary monomer to the luminescent nanoparticles dispersion to which the organic ligand B is bound, and then using an evaporator or a thin film distillation. Therefore, a method for obtaining a monomer dispersion is preferable.

In the second step, for example, a dispersion treatment may be carried out in addition to the mixing. The dispersion treatment may be performed using, for example, a dispersion device such as a bead mill, a paint conditioner, a planetary stirrer, or a jet mill. It is preferable to use a bead mill, a paint conditioner or a jet mill from the viewpoint that the dispersibility of the luminescent nanocrystal particles is good and the average particle size of the luminescent nanocrystal particles can be easily adjusted to a desired range. According to this method, the luminescent nanocrystal particles can be sufficiently dispersed. Therefore, the optical characteristics (for example, external quantum efficiency) of the pixel portion can be improved, and an ink composition having excellent ejection stability can be easily obtained.

Since the luminescent nanoparticles are generally synthesized in a low polar solvent for the convenience of synthesis, the polarity of the organic ligand B bound to the luminescent nanoparticles immediately after the synthesis in the first step is also low. Is common. In this case, in the second step, when the luminescent nanocrystal particles to which the organic ligand B is bound and the polymerizable compound (particularly, a highly polar polymerizable compound having a LogP value of 3.3 or less) are mixed, the viscosity is increased. (Furthermore, agglomeration of luminescent nanocrystal particles) was found to be more likely to occur. On the other hand, the present inventors have found that the use of the organic ligand A can suppress an increase in viscosity (furthermore, aggregation of luminescent nanocrystal particles).

<Ink composition set>
The ink composition set of one embodiment includes the ink composition of the above-described embodiment. The ink composition set may include an ink composition (non-luminescent ink composition) containing no luminescent nanocrystal particles in addition to the ink composition (light emitting ink composition) of the above-described embodiment. The non-emissive ink composition is, for example, a curable ink composition. The non-emission ink composition may be a conventionally known ink composition, and has the same composition as the ink composition (emission ink composition) of the above-described embodiment except that it does not contain luminescent nanocrystal particles. May be.

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

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

<Optical conversion layer and color filter>
Hereinafter, the details of the optical conversion layer and the color filter obtained by using the ink composition set of the above-described embodiment will be described with reference to the drawings. However, the following embodiment is an embodiment when the ink composition contains light-scattering particles. In the following description, the same reference numerals will be used for the same or equivalent elements, and duplicate description will be omitted.

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

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

The first pixel portion 10a and the second pixel portion 10b are luminescent pixel portions (light emitting pixel portions) containing the cured product of the ink composition of the above-described embodiment, respectively. The cured product shown in FIG. 1 contains luminescent nanocrystal particles, an organic ligand, a cured component, and light-scattering particles. The first pixel portion 10a includes a first curing component 13a, a first luminescent nanocrystal particle 11a and a first light scattering particle 12a dispersed in the first curing component 13a, respectively. Similarly, the second pixel portion 10b includes the second curing component 13b and the second luminescent nanocrystal particles 11b and the second light scattering particles 12b dispersed in the second curing component 13b, respectively. including. The curing component is a component obtained by polymerizing a photopolymerizable compound, and includes a polymer of the photopolymerizable compound. In addition to the above-mentioned polymer, the curing component may contain components other than the organic solvent contained in the ink composition (polymer dispersant, unreacted polymerizable compound, etc.). In the first pixel portion 10a and the second pixel portion 10b, the first curing component 13a and the second curing component 13b may be the same or different, and may be the same as or different from the first light scattering particles 12a. It may be the same as or different from the second light-scattering particle 12b.

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

The content of the luminescent nanocrystal particles in the luminescent pixel portion is based on the total mass of the cured product of the luminescent ink composition from the viewpoint of being superior in the effect of improving the external quantum efficiency and obtaining excellent emission intensity. It is preferably 5% by mass or more, and may be 10% by mass or more, 15% by mass or more, 20% by mass or more, or 30% by mass or more. The content of the luminescent nanocrystal particles is preferably 80% by mass or less based on the total mass of the cured product of the luminescent ink composition from the viewpoint of excellent reliability of the pixel portion and excellent emission intensity. It may be 75% by mass or less, 70% by mass or less, or 60% by mass or less.

The content of the light-scattering particles in the luminescent pixel portion is 0.1% by mass or more and 1% by mass based on the total mass of the cured product of the luminescent ink composition from the viewpoint of being more excellent in the effect of improving the external quantum efficiency. It may be more than or equal to 3% by mass or more. The content of the light-scattering particles is 60% by mass or less, 50, based on the total mass of the cured product of the luminescent ink composition, from the viewpoint of improving the effect of improving the external quantum efficiency and the reliability of the pixel portion. It may be mass% or less, 40 mass% or less, 30 mass% or less, 25 mass% or less, 20 mass% or less, or 15 mass% or less.

The third pixel portion 10c is a non-light emitting pixel portion (non-light emitting pixel portion) containing a cured product of the above-mentioned non-light emitting ink composition. The cured product does not contain luminescent nanocrystal particles, but contains light-scattering particles and a cured component. That is, the third pixel portion 10c includes a third curing component 13c and a third light scattering particle 12c dispersed in the third curing component 13c. The third curing component 13c is, for example, a component obtained by polymerizing a polymerizable compound and contains a polymer of the polymerizable compound. The third light-scattering particle 12c may be the same as or different from the first light-scattering particle 12a and the second light-scattering particle 12b.

The third pixel portion 10c has a transmittance of 30% or more with respect to light having a wavelength in the range of, for example, 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 transmittance of the third pixel unit 10c can be measured by a microspectroscopy device.

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

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

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

The base material 40 is a transparent base material having light transmission, and is, for example, a transparent glass substrate such as quartz glass, Pylex (registered trademark) glass, a synthetic quartz plate, a transparent resin film, an optical resin film, or the like. A flexible base material or the like can be used. Among these, it is preferable to use a glass substrate made of non-alkali glass that does not contain an alkaline component in the glass. Specifically, "7059 glass", "1737 glass", "Eagle 200" and "Eagle XG" manufactured by Corning Inc., "AN100" manufactured by Asahi Glass Co., Ltd., "OA-10G" and "OA-10G" manufactured by Nippon Electric Glass Co., Ltd. OA-11 ”is suitable. These are materials with a small thermal expansion rate and are excellent in dimensional stability and workability in high temperature heat treatment.

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

The color filter 100 can be manufactured, for example, by forming the light-shielding portion 20 in a pattern on the base material 40 and then forming the pixel portion 10 in the pixel portion-forming region partitioned by the light-shielding portion 20 on the base material 40. .. The pixel portion 10 has a step of selectively adhering an ink composition (inkjet ink) to a pixel portion forming region on the base material 40 by an inkjet method, a step of removing an organic solvent from the ink composition by drying, and after drying. It can be formed by a method comprising a step of irradiating the ink composition of No. 1 with an active energy ray (for example, ultraviolet rays) and curing the ink composition to obtain a light emitting pixel portion. A light emitting pixel portion can be obtained by using the above-mentioned light emitting ink composition as the ink composition, and a non-light emitting pixel portion can be obtained by using the non-light emitting ink composition.

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

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

In the drying of the ink composition, at least a part of the organic solvent may be removed, and it is preferable that all of the organic solvent is removed. The method for drying the ink composition is preferably drying under reduced pressure (driving under reduced pressure). Drying under reduced pressure is usually carried out at 20 to 30 ° C. for 3 to 30 minutes under a pressure of 1.0 to 500 Pa from the viewpoint of controlling the composition of the ink composition.

For curing the ink composition, for example, a mercury lamp, a metal halide lamp, a xenon lamp, an LED or the like may be used. The wavelength of the light to be irradiated may be, for example, 200 nm or more, and may be 440 nm or less. The exposure amount may be, for example, 10 mJ / cm ² or more, and may be 4000 mJ / cm ² or less.

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

For example, the light conversion layer is a pixel portion containing a cured product of a luminescent ink composition containing blue luminescent nanocrystal particles in place of or in addition to the third pixel portion 10c (3rd pixel portion 10c). It may be provided with a blue pixel portion). Further, even if the light conversion layer includes a pixel portion (for example, a yellow pixel portion) containing a cured product of a luminescent ink composition containing nanocrystal particles that emit light of colors other than red, green, and blue. good. In these cases, it is preferable that each of the luminescent nanocrystal particles contained in each pixel portion of the optical conversion layer has an absorption maximum wavelength in the same wavelength range.

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

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

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

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

Further, in the manufacture of the color filter and the optical conversion layer, the pixel portion may be formed by a photolithography method instead of the inkjet method. In this case, first, the ink composition is coated on the base material in a layered manner to form an ink composition layer. Next, the ink composition layer is exposed in a pattern and then developed using a developing solution. In this way, a pixel portion made of a cured product of the ink composition is formed. Since the developer is usually alkaline, an alkali-soluble material is used as the material of the ink composition. However, in terms of material usage efficiency, the inkjet method is superior to the photolithography method. This is because, in principle, the photolithography method removes about two-thirds or more of the material, which wastes the material. Therefore, in the present embodiment, it is preferable to use an inkjet ink and form a pixel portion by an inkjet method.

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

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

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

[Example 1]
<Preparation of QD powder>
InP nanocrystal dispersion (InP QD inHeptane Red InP QD, QD particle (luminescent nanocrystal particle) concentration 30%, organic ligand: oleic acid) manufactured by Nanosys was dried using an evaporator, and QD powder (QD powder) ( QD particles / organic ligand = 84% by mass / 16% by mass) were obtained.

<Preparation of light-scattering particle dispersion>
In a container filled with argon gas, 4.0 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 (trade name). : PB-821, manufactured by Ajinomoto Fine Techno Co., Ltd., 0.4 g and 1,6-hexanediol dimethacrylate (trade name: Miramer M200, manufactured by Miwon), 5.6 g were mixed. Then, zirconia beads (diameter: 1.25 mm) were added to the obtained mixture, and the mixture was shaken for 2 hours using a paint conditioner to disperse the mixture. Then, the zirconia beads were removed from the mixture with a polyester mesh filter to obtain a light-scattering particle dispersion.

<Preparation of ink composition>
3.1 g of the QD powder obtained above, 0.31 g of linolenic acid (organic ligand), and dicyclopentanyl acrylate (LogP value: 2.93, trade name: FA-513M, Hitachi Kasei Co., Ltd.) 3 A QD monomer solution was obtained by mixing with .82 g and stirring with a magnetic stirrer for 2 hours. There, 0.50 g of Omnirad TPO-H (manufactured by IGM Resin) and 0.01 g of Omnirad 819 (manufactured by IGM Resin) as a photopolymerization initiator, and 0.10 g of Irganox 1010 (manufactured by BASF Japan) as an antioxidant. And was added and stirred. Further, 1.0 g of the light-scattering particle dispersion obtained above was added. Finally, 0.53 g of 1,6-hexanediol dimethacrylate (LogP value: 3.13, trade name: Viscort # 230, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and dodecyl methacrylate (LogP value: 5.64, product). Name: Light Ester L, manufactured by Kyoeisha Chemical Co., Ltd.) After adding 0.55 g, the mixture was continuously stirred for 30 minutes to obtain an ink composition.

[Comparative Example 1]
<Preparation of ink composition>
3.1 g of the QD powder obtained above and 4.02 g of dicyclopentanyl acrylate (LogP value: 2.93, trade name: FA-513M, Hitachi Kasei Co., Ltd.) were mixed and subjected to a magnetic stirrer. The mixture was stirred for 2 hours to obtain a QD monomer solution. There, 0.50 g of Omnirad TPO-H (manufactured by IGM Resin) and 0.01 g of Omnirad 819 (manufactured by IGM Resin) as a photopolymerization initiator, and 0.10 g of Irganox 1010 (manufactured by BASF Japan) as an antioxidant. And was added and stirred. Further, 1.0 g of the light-scattering particle dispersion obtained above was added. Finally, 0.59 g of 1,6-hexanediol dimethacrylate (LogP value: 3.13, trade name: Viscort # 230, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and dodecyl methacrylate (LogP value: 5.64, product). Name: Light Ester L, manufactured by Kyoeisha Chemical Co., Ltd.) After adding 0.58 g, the mixture was continuously stirred for 30 minutes to obtain an ink composition.

[Comparative Example 2]
<Synthesis of comparative organic ligand>
After putting polyethylene glycol (Mn350) (manufactured by Sigma-Aldrich) into a flask, the amount of succinic anhydride (manufactured by Sigma-Aldrich) equal to that of polyethylene glycol (Mn350) is added to the flask while stirring in a nitrogen gas environment. Was added. The internal temperature of the flask was raised to 80 ° C. and stirred for 8 hours to obtain a comparative organic ligand represented by the following formula (A) as a pale yellow viscous oil.

<Preparation of ink composition>
An ink composition was obtained by the same method as in Example 1 except that the comparative organic ligand synthesized above was used instead of linolenic acid (organic ligand).

[Measurement of viscosity of ink composition]
The viscosities of the ink compositions of Examples and Comparative Examples at 40 ° C. were measured using an E-type viscometer. The results are shown below.
Example 1: 14.2 cP
Comparative Example 1: Cannot be measured (because the luminescent nanocrystal particles in the ink composition are aggregated)
Comparative Example 2: 19.7cP

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

Claims (8)

It contains luminescent nanocrystal particles, an organic ligand capable of binding to the surface of the luminescent nanocrystal particles, and a photopolymerizable compound.
An ink composition in which the organic ligand comprises an organic ligand having two or more carbon-carbon double bonds. The first aspect of claim 1, wherein the content of the organic ligand having two or more carbon-carbon double bonds is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the luminescent nanocrystal particles. Ink composition. The ink composition according to claim 1 or 2, wherein the organic ligand having two or more carbon-carbon double bonds further has a carboxyl group. The ink composition according to any one of claims 1 to 3, which is used for forming an optical conversion layer by an inkjet method. The cured product of the ink composition according to any one of claims 1 to 4. A plurality of pixel portions and a light-shielding portion provided between the plurality of pixel portions are provided.
The plurality of pixel portions are light conversion layers having a light emitting pixel portion containing a cured product of the ink composition according to any one of claims 1 to 4. As the light emitting pixel portion,
A first luminescent pixel portion containing luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a emission peak wavelength in the range of 605 to 665 nm.
A second luminescent pixel portion containing luminescent nanocrystal particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a emission peak wavelength in the range of 500 to 560 nm.
The optical conversion layer according to claim 6. A color filter comprising the light conversion layer according to claim 6 or 7.

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