JP2020070427A - Ink composition, inkjet ink, printed matter and color filter - Google Patents

Abstract

To provide an ink composition that is excellent in re-dispersibility after sedimentation, has reduced transmission of backlight (excitation light) for excellent photoconversion efficiency, and gives light emission with high color purity, and an inkjet ink, a printed matter and a color filter comprising the composition.SOLUTION: The problem is solved by an ink composition containing a quantum dot (A), organic fine particles (B), metal oxide fine particles (C), and a binder component (D), and an inkjet ink, a printed matter and a color filter comprising the ink composition.SELECTED DRAWING: None

Description

  The present invention relates to an ink composition which is excellent in redispersibility, has high light efficiency characteristics, and can provide a printed matter having high quality image quality.

  Since a display device using a liquid crystal display (LCD) or an organic EL display (OLED) has different spectrum shapes of backlights, it is necessary to select a pigment or dye having an optimum hue or transmittance characteristic as a color filter. There is. Further, in order to achieve high color purity, it is necessary to increase the pigment and dye concentrations, but if the concentration is simply increased, the transmittance will decrease and sufficient brightness cannot be ensured.

  As a material that achieves both high color purity and high brightness, self-luminous semiconductor quantum dots are drawing attention. Quantum dots are minute particles (dots) formed for confining electrons in a minute space in order to develop unique optical properties according to quantum mechanics. The size of one quantum dot is 1 nm to several tens of nm in diameter and is composed of about 10,000 atoms or less. The emitted fluorescence wavelength can be continuously controlled by the size of the particles, and sharp emission with high symmetry of the fluorescence intensity wavelength distribution can be obtained.

However, when the quantum dots are used for a color filter, the quantum dots are non-scattering particles, and therefore, there is a problem that the light of the backlight is transmitted and is not sufficiently excited so that the light is not converted.
In order to solve the above problems, for example, Patent Document 1 discloses that a light diffusion layer having scattering particles is provided in addition to a color conversion layer including quantum dots.
Further, Patent Document 2 discloses a self-luminous resin composition containing quantum dots and inorganic scattering particles of several hundred nanometer level.
Further, in Patent Document 3, an inkjet ink having a sedimentation-separation-inhibiting property and ejection stability, which comprises titanium oxide which is a light-scattering particle coated with quantum dots and alumina, and a polymer dispersant, and is composed of the ink. The light wavelength layer, the color filter and the like are described.

JP, 2017-161938, A JP, 2016-098375, A JP, 2018-109141, A

However, in the method described in Patent Document 1, although the light wavelength conversion efficiency is improved by the light diffusing layer, the complexity of the display device itself is increased, which causes a problem in processability.
In Patent Document 2, excellent color reproduction characteristics and high light efficiency are exhibited, but since the inorganic scattering particles have a larger specific gravity than organic substances, there is a problem in the sedimentation stability of the composition. For example, when it is used as a resist ink, there is a concern about problems such as generation of aggregated foreign matter in the color filter forming step. Further, when the particles settle, the scattering particles agglomerate with each other, which makes redispersion difficult.
In Patent Document 3, although the sedimentation stability and the ejection stability are excellent, once sedimentation is difficult, it is difficult to disperse them again, and it is difficult to form a uniform film.

  Therefore, an object of the present invention is to provide an ink composition that is excellent in redispersibility after sedimentation, has reduced backlight (excitation light) transmission, is excellent in light conversion efficiency, and is capable of obtaining light emission with high color purity. And an inkjet ink, a printed matter and a color filter comprising the composition.

That is, the present invention relates to the following inventions.
[1] An ink composition containing quantum dots (A), organic fine particles (B), metal oxide fine particles (C), and a binder component (D).

[2] The ink composition according to [1], wherein the content of the organic fine particles (B) is 2% by mass or more and 30% by mass or less based on the total solid content of the ink composition.

[3] The ink according to [1] or [2], wherein the content of the metal oxide fine particles (C) is 2% by mass or more and 20% by mass or less based on the total solid content of the ink composition. Composition.

[4] Any of [1] to [3], wherein the mass ratio ((B) / (C)) of the organic fine particles (B) to the metal oxide fine particles (C) is 0.4 or more and less than 0.8. The ink composition according to item 1.

[5] The ink composition according to any one of [1] to [4], wherein the organic fine particles (B) include at least one kind of fine particles selected from the group consisting of melamine resin fine particles and acrylic resin fine particles.

[6] The ink composition according to any one of [1] to [5], wherein the metal oxide fine particles (C) have an average primary particle diameter of 30 to 100 nm.

[7] The ink composition according to any one of [1] to [6], wherein the metal oxide fine particles (C) are titanium oxide fine particles.

[8] The quantum dot (A) is at least 1 selected from the group consisting of Group 2 elements, Group 10 elements, Group 11 elements, Group 12 elements, Group 13 elements, Group 14 elements, Group 15 elements and Group 16 elements. The ink composition according to any one of [1] to [7], which is a compound semiconductor containing a seed element.

[9] An inkjet ink containing the ink composition according to any one of [1] to [8].

[10] A printed matter formed from the inkjet ink according to [9].

[11] A color filter comprising a filter segment formed from the inkjet ink according to [9].

  According to the present invention, an ink composition having excellent redispersibility after sedimentation, reduced backlight (excitation light) transmission, excellent light conversion efficiency, and capable of obtaining luminescence with high color purity, and It is possible to provide an inkjet ink, a printed matter, and a color filter made of the composition.

Hereinafter, the present invention will be described in detail.
<Quantum dot (A)>
The quantum dot (A) used in the present invention is a nano-sized semiconductor. The quantum dot (A) used in the present invention is not particularly limited as long as it is a quantum dot capable of emitting light by photoexcitation. The quantum dot (A) contains at least one element selected from the group consisting of Group 2 elements, Group 10 elements, Group 11 elements, Group 12 elements, Group 13 elements, Group 14 elements, Group 15 elements and Group 16 elements. It is preferably a compound semiconductor containing, and may contain two or more kinds of elements.

Specifically, Si, Ge, Sn, Se, Te, B, C (including diamond), P, Co, Au, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, Be. BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4, Ge 3 N 4, Al 2 O 3 _{, (Al, Ga, In)} 2 (S, Se, Te) 3, Al 2 _{O 3, AgInSe 2, CuGaSe 2} , CuInS 2, CuGaS 2, CuInSe 2, AgGaSe 2, AgGaS 2, CsPbCl 3, CsPbI 3, suitable combinations of CsPbBr ₃ and two or more materials.
Of the above, at least two selected from the group of elements represented by Zn, Cd, B, Al, Ga, In, C, Si, Ge, Sn, N, P, As, Sb, Pb, S, Se and Te. A semiconductor made of a compound containing the element is preferable. More preferably, it is a semiconductor composed of a compound containing at least two elements selected from the group of elements represented by Zn, B, Al, Ga, In, C, Si, Ge, Sn, N, P, S and Te. .. More preferably, a semiconductor containing In as a constituent element due to its narrow bandgap is preferable for use in emitting visible light.

  The structure of the quantum dot (A) may be a uniform single structure, a multilayer structure such as a core / shell structure, a gradient structure or the like, or a mixed structure thereof, as long as the structure includes the elements described above. Good.

The quantum dot (A) is preferably a compound semiconductor having a core / shell structure. The shell structure may be one layer or two layers, and if the core structure is covered with a compound semiconductor component different from the compound semiconductor component forming the core and the outside is a compound semiconductor with a large band gap, it is generated by energy excitation such as light. Excitons (electron-hole pairs) are confined in the core. As a result, the probability of non-radiative transition on the compound semiconductor surface is reduced, and the quantum yield of light emission and the stability of the fluorescence characteristics of quantum dots are improved. When used as quantum dots, suitable material combinations satisfying the above conditions include CdSe / ZnS, CdSe / ZnSe, CdS / ZnS, CdSe / CdS, CdTe / CdS, InP / ZnS, InP / ZnSeZnS, PbSe / PbS, GaP / ZnS, Si / ZnS, InN / GaN, InP / CdSSe, InP / ZnSeTe, InGaP / ZnSe, InGaP / ZnS, Si / AlP, InP / ZnSTe, InGaP / ZnSTe, InGaP / ZnSSe, etc. are mentioned. Be done.
ZnS, CdS, ZnSe, etc. are often used as the shell component of the compound semiconductor forming the quantum dots (A) used in the present invention. Among these, when the core component contains In and P as constituent elements, it is particularly excellent in properties such as exciton confinement as a quantum dot and can be suitably used.

  The average particle size of the inorganic material portion of the compound semiconductor forming the quantum dots (A) is preferably 0.5 nm to 100 nm, and the particle size that can obtain desired characteristics can be selected. The average particle size of the semiconductor fine particles and the core / shell type core average particle size in the case of a single semiconductor composition are preferably 0.5 nm to 25 nm, and more preferably 0.5 nm to 15 nm. When the average particle diameter is 0.5 nm or more, it is preferable in terms of synthesis, and when it is 100 nm or less, the quantum confinement effect is improved and desired fluorescence can be obtained.

  The quantum dots are characterized in that even if the same material is used, the fluorescence wavelength can be arbitrarily changed by changing the core particle diameter, and it is necessary to set the particle diameter according to the desired fluorescence wavelength. In the case of the core / shell type, one compound semiconductor may contain a plurality of shell fine particles, and the average thickness of the shell corresponds to the difference between the particle radius of the inorganic material portion and the core particle radius. The shape of the quantum dots (A) is not limited to a spherical shape, but may be a rod shape, a disk shape, or another shape.

  The average particle size as used herein refers to a value obtained by observing semiconductor fine particles with a transmission microscope, measuring 30 sizes at random, and adopting the average value. At this time, since the semiconductor fine particles are accompanied by the below-described ligand, the semiconductor material portion is specified by using the scanning transmission electron microscope accompanied by the energy dispersive X-ray analysis, and then the electron density of the electron density in the transmission electron microscope image is determined. Due to the difference, the particle size is measured by utilizing the fact that the semiconductor fine particle portion is imaged dark with respect to the ligand in the postoperative procedure.

  The quantum dots (A) may be further covered with an organic material. These organic substances are referred to as a coating material or a protective material, and in particular, they are often referred to as a treatment agent for the surface of fine particles during synthesis and, in the case of quantum dots, a ligand or a ligand. In general, an organic substance that can be used as a coating material has a strong polarity that is adsorbed on the metal part of the inorganic semiconductor fine particles, or has a non-shared electron pair, and further has a structure in which a carbon chain or an aromatic ring is linked, a polyalkylene glycol. It is an organic substance having a partial structure that has a high affinity with a solvent or resin used as a coating liquid or ink by having a structure or the like. Such organic substances are generally well known as dispersants for organic and inorganic pigments and inorganic compound materials, surfactants and emulsifiers used in the formation of detergents and emulsions. These compounds can also be used in the invention. Further, a compound having a partial structure used as a ligand (ligand) of a metal complex, particularly a compound having a chelate ligand structure having two or more coordination sites to a metal is adsorbed on the metal part of the compound semiconductor. It can be used because it is easy to remove and does not easily detach.

  In the present invention, an organic substance that can be used as a treating agent during synthesis has a high boiling point and is preferably an organic substance having an alkyl group having 8 or more carbon atoms as a partial structure, which can be expected to interact with the alkyl chain portion. Further, in order to strengthen the action on the compound semiconductor, it may have a polar group, and examples of the organic substances that can be treated include organic acids, organic amines, sulfur-containing organic substances, and phosphorus-containing organic substances.

As the organic acid, a compound having a carboxylic acid at the terminal can be used, can contain an aromatic ring and an ether group, and may have a plurality of carboxylic acids in the molecule. Specific examples include benzoic acid, biphenylcarboxylic acid, butylbenzoic acid, hexylbenzoic acid, cyclohexylbenzoic acid, naphthalenecarboxylic acid, hexanoic acid, heptanoic acid, octanoic acid, ethylhexanoic acid, hexenoic acid, octenoic acid, citronellic acid, suberin. Acid, ethylene glycol bis (4-carboxyphenyl) ether, (2-butoxyethoxy) acetic acid and the like can be mentioned.
The organic acid having an alkyl group having 8 or more carbon atoms as a partial structure is, among organic acids, a compound having an alkyl group having 8 or more carbon atoms, specifically, nonanoic acid, decanoic acid, lauric acid, myristin Examples thereof include acids, palmitic acid, stearic acid, tricosanoic acid, lignoceric acid, oleic acid, eicosadienoic acid, linolenic acid, sebacic acid, and (2-octyloxy) acetic acid.

As the organic amine, a compound having an amino group at the terminal can be used, and examples thereof include n-butylamine, iso-butylamine, tert-butylamine, n-hexylamine, n-heptylamine and cyclohexylamine.
Examples of the organic amine having an alkyl group having 8 or more carbon atoms as a partial structure include octylamine, dodecaamine, heptadecane-9-amine, N, N-dimethyl-n-octylamine and the like.

Examples of the sulfur-containing organic substance include thiols and disulfides.
Examples of thiols include allyl mercaptan, 1,3-benzenedimethanethiol, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazolebutanethiol. , N-hexanethiol, n-heptanethiol, and the like.
Examples of sulfur-containing organic substances of thiols having an alkyl group having 8 or more carbon atoms as a partial structure include dodecanethiol, 1-docosanethiol, tert-dodecylmercaptan, and 2-ethylhexanethiol.
Examples of disulfides include bis (4-chloro-2-nitrophenyl) disulfide, hexyl sulfide, 3,3 ′, 5,5′-tetrachlorodiphenyl disulfide and the like.
Examples of sulfur-containing organic substances of sulfides having an alkyl group having 8 or more carbon atoms as a partial structure include dodecyl disulfide, octadecyl disulfide, dodecyl octadecyl disulfide and the like.

Examples of the phosphorus-containing organic matter include butyl phosphate, hexyl phosphate, diisopropyl phosphate, mono-2-ethylhexyl (2-ethylhexyl) phosphonate, propylphosphonic acid, hexylphosphonic acid, methyl hexylphosphonate, and hexyl isopropylphosphonate. Can be mentioned.
Examples of the phosphorus-containing organic matter having an alkyl group having 8 or more carbon atoms as a partial structure include octyl phosphate, didodecyl phosphate, dodecyl phosphate, dodecylphosphonic acid, hexylphosphonate dodecyl, decylphosphonic acid, and isopropyl decylphosphonate. Be done.

As the method of synthesizing the quantum dots (A), a generally known method such as a method of synthesizing in a glass, a method of synthesizing in an aqueous solution, a method of synthesizing in an organic solvent can be used. In particular, InP / ZnS core-shell quantum technical literature with respect to dot "Journal of American Chemical Society.2007,129,15432-15433", "Journal of American Chemical Society.2016,138,5923-5929", InCuS ₂ / ZnS core-shell Type quantum dots, the technical document “Journal of American Chemical Society. 2009, 131, 5691-5697”, the technical document “Chemistry of Materials. 2009, 21, 422-2429”, and the Si quantum dot, the technical document “Journal of Chemical Society 2010, 132, 248-253 ”.

At least a part of the surface of the quantum dots (A) may be coated with a coating material amount different from that at the time of synthesis. As a method of changing the coating material, for example, a method of stirring the compound semiconductor surface-treated with the first coating material and the second coating material to be replaced in a diluting solvent, or the surface of the first coating material is used. A method of removing the solvent from the treated compound semiconductor by centrifugation or the like and then redispersing the compound semiconductor in the solvent containing the second coating material to be replaced may be used.
By using the above method, it is possible to select a coating material suitable for the application and required characteristics, and it is possible to improve the affinity with the solvent or resin that is preferably used for the coating liquid or ink.

The content of the quantum dots (A) in the ink composition of the present invention is preferably 5 to 55% by mass, and more preferably 10 to 50% by mass, based on the total solid content of the ink composition.
When the content is 5% by mass or more, the light leakage of the backlight can be suppressed, and the color conversion from the quantum dots is sufficiently performed, which is preferable. Further, when the content is 55% by mass or less, dispersion of the ink composition is stabilized, and a viscosity range that allows ejection when used as an inkjet is preferable.

<Organic fine particles (B)>
The organic fine particles (B) are fine particles made of an organic component, and the shape thereof is not limited at all, but for example, spherical particles capable of sufficiently scattering excitation light are preferable. If the spherical one is used, the excitation light can be sufficiently scattered, the quantum dots (A) can be sufficiently excited, and as a result, the luminous efficiency of the printed matter can be further enhanced.

  Examples of types of organic fine particles include silicone-based fine particles, melamine-based resin fine particles, melamine-benzoguanamine-based resin fine particles, acrylic-based resin fine particles (for example, polymethylmethacrylate-based fine particles (hereinafter, may be referred to as PMMA-based fine particles), acrylic. -Styrene-based copolymer particles, polycarbonate-based particles, polyethylene-based particles, polystyrene-based particles, benzoguanamine-based resin particles, etc. These may be used alone or in combination of two or more kinds. Good.

  Specific examples of the silicone-based fine particles include KMP-594, KMP-597, KMP-598, KMP-600, KMP-601, KMP-602 (manufactured by Shin-Etsu Chemical Co., Ltd.), Trefil E-506S, EP-9215 ( Toray Dow Corning Co., Ltd.) and the like.

Specific examples of the melamine-based resin fine particles include eposter SS, eposter S, eposter FS, eposter S6, eposter S12 (manufactured by Nippon Shokubai Co., Ltd.) and the like.
Specific examples of the melamine-benzoguanamine-based resin fine particles include Eposter M30 (manufactured by Nippon Shokubai Co., Ltd.).

Specific examples of the acrylic resin fine particles include Eposter MA1002, Eposter MA1004, Eposter MA1006, Eposter MA1010 (manufactured by Nippon Shokubai Co., Ltd.), Toughtic FH-S005, Toughtic FH-S008, Toughtic FH-S010, Toughtic FH-S015, Toughtic. FH-S020 (manufactured by Toyobo Co., Ltd.), Chemisnow MX-80H3wT, MX-150, MX-180TA, MX-300, MX-500, MX-1000, MX-1500H, MX-2000, MX-3000 (Souken Chemical Co., Ltd.) Company-made) etc.
Specific examples of the acryl-styrene copolymer fine particles include Eposter MA2003 (manufactured by Nippon Shokubai Co., Ltd.), FS-102, FS-201, FS-301, MG-451, MG-351, (Nippon Paint Industrial Coating). Su Co., Ltd.) and the like.

Specific examples of the polycarbonate-based fine particles include fine particles described in JP-A-2014-125495, fine particles obtained by the production method described in JP-A-2011-26471, and fine particles obtained by the method described in JP-A-2001-213970. Is mentioned.
Specific examples of the polyethylene-based fine particles include Miperon XM-220, XM221U (manufactured by Mitsui Chemicals, Inc.), Flow Beads LE-1080 (manufactured by Sumitomo Seika Chemicals, Ltd.), and the like.
Specific examples of the polystyrene-based fine particles include Chemisnow SX-130H, SX-350H, SX-500H (manufactured by Soken Kagaku Co., Ltd.).
Specific examples of the benzoguanamine-based resin fine particles include Eposter MS, Eposter M05, and Eposter L15 (manufactured by Nippon Shokubai Co., Ltd.).

Further, the organic fine particles (B) may have a fluorine substituent.
Examples of the organic fine particles having a fluorine substituent include a fluorine substituent-containing polymethylmethacrylate fine particle, a fluorine substituent-containing acryl-styrene copolymer particle, a fluorine substituent-containing polycarbonate particle, a polyvinyl fluoride particle, and the like. By having a fluorine substituent, agglomeration between particles is suppressed and redispersibility is facilitated even if the particles once settle. Further, by having a fluorine substituent, the refractive index can be made lower than that of the binder component containing the quantum dots (A), and the luminous efficiency can be further improved in combination with the scattering effect, which is preferable.

  The average particle size of the organic fine particles (B) is not particularly limited, but is preferably 100 nm or more and 1000 nm or less. Within the above range, a sufficient scattering effect can be exhibited. Further, even if the scattering intensity (haze value) is small, the scattering angle is wide, so that scattering effective for total reflection can be obtained, and the scattering effect inside the coating film is enhanced, so that the light efficiency is improved, which is preferable.

  As the organic fine particles (B), it is preferable to use a dispersion liquid which is previously dispersed in a solvent. As a dispersion method, a method of using a disperser using a dispersant suitable for the surface state of the organic fine particles (B) is preferable. As the disperser, a paint conditioner (manufactured by Red Devil Co.), a ball mill, a sand mill (“Dyno Mill” manufactured by Shinmaru Enterprises Co., Ltd.), an attritor, a pearl mill (“DCP mill” manufactured by Eirich, etc.), a co-ball mill, a homomixer, Homogenizer (“Clearmix” manufactured by M Technique Co., Ltd.), wet jet mill (“Genus PY” manufactured by Genus, “Nanomizer” manufactured by Nanomizer), microbead mill (“Super Apec Mill” manufactured by Kotobuki Industries Co., Ltd.) "Ultra apek mill") can be used. When using a medium for the disperser, it is preferable to use glass beads, zirconia beads, alumina beads, magnetic beads, polystyrene beads and the like. Regarding dispersion, two or more kinds of dispersers or two or more kinds of media having different sizes may be respectively used and carried out stepwise.

  The average particle size and particle size distribution of the organic fine particles (B) can be adjusted by synthesis conditions such as polymerization temperature and polymerization composition, or dispersion conditions such as a disperser, a dispersion medium, a dispersion time and a dispersant.

  The content of the organic fine particles (B) is preferably 2% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less, based on the total solid content of the ink composition. When the content is 2% by mass or more, it is possible to scatter the light of the backlight and excite the quantum dots. When it is 30% by mass or less, poor compatibility due to aggregation of organic fine particles can be prevented.

<Metal oxide fine particles (C)>
The ink composition of the present invention contains metal oxide fine particles (C) in addition to the quantum dots (A) and the organic fine particles (B). Examples of the metal oxide fine particles (C) include titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), hafnium oxide (HfO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), and pentoxide. At least one selected from the group consisting of tantalum (Ta ₂ O ₅ ), indium oxide (In ₂ O ₂ ), tin oxide (Sn ₂ O ₂ ), indium tin oxide (ITO), and zinc oxide (ZnO). Examples include fine particles made of a material. Among these, fine particles of titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), and zinc oxide (ZnO) are preferable, and titanium oxide (TiO ₂ ) fine particles are preferable from the viewpoint of translucency, dispersibility, weather resistance and light resistance. Particularly preferred.

  Titanium oxide can be used without particular limitation, and titanium oxide which has been surface-treated in advance may be used. By performing the surface treatment, it is possible to stabilize dispersion and improve weather resistance. Any known surface treatment method and surface treatment agent can be used.

  Specific examples of titanium oxide include "Taipec CR-50, 50-2, 57, 80, 90, 93, 95, 953, 97, 60, 60-2, 63, 67, 58, 58- manufactured by Ishihara Sangyo Kaisha, Ltd. 2,85 "" Taipaque R-820,830, 930,550,630,680,670,580,780,780,780-2,850,855 "" Taipaque A-100, 220 "" Taipaque W-10 "" Taipaque " PF-740, 744 "" TTO-55 (A), 55 (B), 55 (C), 55 (D), 55 (S), 55 (N), 51 (A), 51 (C) "" "TTO-S-1, 2" "TTO-M-1, 2", manufactured by Teika "Titanics JR-301, 403, 405, 600A, 605, 600E, 603, 805, 806, 701, 800, 808". "Titanic JA-1, C, 3, 4, 5 "," Titanics MT-500B, 500SA, 600B, 600SA, 700B, 700SA ", DuPont" TYPURE R-900, 902, 960, 706, 931 ", Sakai "TITON A-120, TITON SA-120" manufactured by Kagaku Kogyo Co., Ltd. and the like can be mentioned.

  As the metal oxide fine particles (C), powder may be used as it is, but it is preferable to disperse the fine particles in a solution in advance from the viewpoint of suppressing sedimentation in the ink composition, and it is preferable to use a dispersion liquid.

  From the viewpoint of redispersibility of the ink composition, it is preferable that there is no strong aggregation between the metal oxide fine particles (C). Therefore, the average primary particle diameter of the metal oxide fine particles (C) is preferably 100 nm or less, more preferably 30 nm or more and 100 nm or less. Within the above range, aggregation between particles can be prevented and an ink composition having excellent redispersibility can be provided.

  The content of the metal oxide fine particles (C) is preferably 2% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 15% by mass or less, based on the total solid content of the ink composition. When the content is 2% by mass or more, it is possible to suppress omission of the backlight. When the content is 20% by mass or less, poor compatibility can be prevented due to aggregation of the metal oxide fine particles (C) in the composition.

The ratio ((B) / (C)) of the organic fine particles (B) to the metal oxide fine particles (C) in the ink composition is preferably 0.2 or more and less than 4.5. It is more preferably 0.3 or more and less than 1.0, and particularly preferably 0.4 or more and less than 0.8.
By setting the content in the above range, it is possible to provide an ink composition which is excellent in redispersibility even when it is settled while suppressing the settling of aggregates. Further, it is possible to maintain a high external quantum efficiency for a printed matter formed from the ink composition. For example, in the case of only the organic fine particles (B), phase separation due to sedimentation or aggregation in the ink composition is unlikely to occur, and emission efficiency is at a usable level, but it is difficult to suppress excitation light transmission, and emission color purity is descend. Further, in the case of only the metal oxide fine particles (C), since the specific gravity of the metal oxide fine particles is larger than that of the other components, sedimentation or aggregation occurs, which makes practical use difficult.

  As the metal oxide fine particles (C), it is preferable to use a dispersion liquid in which the metal oxide fine particles (C) are previously dispersed in a solvent, as in the organic fine particles (B). As a dispersing method, it is preferable to use a dispersant suitable for the surface state of the metal oxide fine particles (C) and a dispersing machine similar to that for the organic fine particles (B).

  The average particle size and particle size distribution of the metal oxide fine particles (C) can be adjusted to a suitable range by appropriately adjusting the dispersion conditions such as a disperser, a dispersion medium, a dispersion time, and a dispersant. ..

  In the present specification, the “average particle size” and the “particle size” are different from the average primary particle size, and are the dispersed particle size in the composition in consideration of the particle size of secondary particles due to aggregation. .. These can be measured by an optical microscope or obtained by a dynamic light scattering method. Here, the reason for distinguishing from the average primary particle diameter is that even when scattering particles having the same average primary particle diameter are used, the organic fine particles (B), metal oxide fine particles (C), etc. in the composition are This is because the average particle size and particle size distribution may differ depending on the dispersed state. "Average particle size" is the value of the dispersed particle size in 50% by volume of the measurement sample, and the content of particles having a particle size of 600 nm or more is the volume% of the particle size of 600 nm or more in the dispersed particle size of the measurement sample. Is. These can be measured by "Nanotrack UPA" manufactured by Nikkiso Co., Ltd. by the dynamic light scattering method.

<Binder component (D)>
The ink composition of the present invention contains a binder component (D). The binder component (D) is not particularly limited, and preferably a resin or a polymerizable monomer can be used. The resin and the polymerizable monomer may form a crosslinked body in response to heat or light, or may be a crosslinked body formed by a crosslinking agent described later.

[resin]
Examples of the resin include petroleum resin, maleic acid resin, nitrocellulose, cellulose acetate butyrate, cyclized rubber, chlorinated rubber, alkyd resin, acrylic resin, polyester resin, amino resin, vinyl resin, butyral resin, straight chain olefin. Resin, aromatic polyether resin, polyimide resin, fluorene polycarbonate resin, fluorene polyester resin, polycarbonate resin, polyamide (aramid) resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyparaphenylene resin, polyamideimide resin, Examples thereof include polyethylene naphthalate (PEN) resin and fluorinated aromatic polymer resin, which can be appropriately selected depending on the coating, printing method and substrate.
The thermosetting resin may be an epoxy resin, an oxetane group-containing resin, an isocyanate group-containing resin, a carboxyl group-containing resin, an allyl ester curable resin, or the like, and the ultraviolet curable resin may be a silsesquioxane ultraviolet ray. Curing resin etc. are mentioned.

Specific examples of the resin include BR-50, BR-52, MB-2539, BR-60, BR-64, BR-73, BR-75, MB-2389, BR-80, BR- manufactured by Mitsubishi Rayon Co., Ltd. 82, BR-83, BR-84, BR-85, BR-87, BR-88, BR-90, BR-95, BR-96, BR-100, BR-101, BR-102, BR-105, BR-106, BR-107, BR-108, BR-110, BR-113, MB-2660, MB-2952, MB-3012, MB-3015, MB-7033, BR-115, MB-2478, BR- 116, BR-117, BR-118, BR-122, ER-502, A-11, A-12, A-14, A-21, B-38, B-60, B manufactured by Wilber Ellis. -64, B 66, B-72, B-82, B-44, B-48N, B-67, B-99N, DM-55, JONCRYL67, JONCRYL678, JONCRYL586, JONCRYL611, JONCRYL680, JONCRYL682, JONCRYL683, JONCRY made by BASF. JONCRYL819, JONCRYL JDX-C3000, JONCRYL JDX-C3080, solvein resin CL, CNL, C5R, TA3, TA5R manufactured by Nisshin Chemical Industry, vinyl resin E15 / 45, H14 / 36, H40 / 43, E15 / manufactured by Wacker. 45M, E15 / 40M, Arakawa Chemical Co., Ltd. super ester 75, ester gum HP, Malquid 33, Yasuhara Co. YS Polystar T80, Mitsui Chemicals Hiretts HR 200X, include Sartomer Co. SMA2625P.
The above resins may be used alone or in combination of two or more.

When a resin is used, its mass average molecular weight (Mw) is preferably 1,000 to 50,000, and 3,000 to 45,000 in order to stably eject the ink composition from the inkjet head. Is particularly preferable. When the mass average molecular weight is 1,000 or more, the coating film resistance of the printed matter is good, and when the mass average molecular weight is 50,000 or less, the viscosity of the composition is within the appropriate viscosity range of the inkjet, and the inkjet head is clogged or ejected. Sexual deterioration can be prevented.
The mass average molecular weight can be determined as a styrene-equivalent molecular weight by gel permeation chromatography.

  When a resin is used, the content of the resin can be arbitrarily set within a range in which the ink composition can be stably ejected from the inkjet head. The content of the resin is preferably 5 to 80% by mass based on the total solid content of the ink composition. Within the above range, a coating film having good scratch resistance and chemical resistance can be obtained. Further, when used as an inkjet ink, the viscosity of the composition falls within an appropriate viscosity range of the head, and it is possible to prevent clogging of the head and deterioration of dischargeability.

[Polymerizable monomer]
As the polymerizable monomer, a polymerizable monomer that is polymerized by irradiation with light may be used. The monomer that can be used is not particularly limited, and may be a photoradical polymerizable monomer or a photocationic polymerizable monomer, and a monofunctional monomer and a polyfunctional monomer may be used alone or in combination. Good.

(Photo radical polymerizable monomer)
Specific examples of the photo-radical polymerizable monomer include benzyl (meth) acrylate, (ethoxy (or propoxy) -modified) 2-phenoxyethyl (meth) acrylate, dicyclopentenyl (oxyethyl) (meth) acrylate and phenoxy as monofunctional monomers. Diethylene glycol (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, Dipropylene glycol (meth) acrylate, β-carboxyl ethyl (meth) acrylate, trimethylolpropane formal (meth) acrylate, isoamyl (meth) acryl Rate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, 2-hydroxy-3-phenoxy. Propyl (meth) acrylate, 1,4-cyclohexanedimethanol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, acryloylmorpholine, N- Vinylcaprolactam, N-vinylpyrrolidone, N-vinylformamide, N-acryloyloxyethylhexahydrophthalimide and the like can be mentioned.

Further, as the photo-radical-polymerizable polyfunctional monomer, dimethylol tricyclodecane di (meth) acrylate, (ethoxy (or propoxy) -ized) bisphenol A di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (ethoxy (or propoxy) -modified) 1,6-hexanediol di (meth) acrylate, (ethoxy (or propoxy) -modified) neopentyl glycol di (meth) acrylate, hydroxypivalic acid neo Pentyl glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, (neopentyl glycol modified) trimethylolpropane di (meth) acrylate, tripropylene glycol di (meth) acrylate, di Clopentanyl di (meth) acrylate, pentaerythritol tri (or tetra) (meth) acrylate, trimethylolpropane tri (or tetra) (meth) acrylate, tetramethylolmethane tri (or tetra) (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate and the like can be mentioned.
The above materials may be used alone or in combination of two or more.

(Photo-cationic polymerizable monomer)
Specific examples of the cationic photopolymerizable monomer include glycidyl methacrylate, 2-ethylhexyl oxetane, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, and 3-hydroxymethyl-3 as monofunctional monomers. -Propyl oxetane, 3-hydroxymethyl-3-normal butyl oxetane, 3-hydroxymethyl-3-phenyl oxetane, 3-hydroxymethyl-3-benzyl oxetane, 3-hydroxyethyl-3-methyl oxetane, 3-hydroxyethyl- 3-ethyloxetane, 3-hydroxyethyl-3-propyloxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyloxe Down, 3-hydroxypropyl-3-phenyl oxetane, 3-hydroxybutyl-3-methyl oxetane, and the like.

Further, as a cationic photopolymerizable polyfunctional monomer, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a phenol novolac type epoxy compound, trimethylolpropane glycidyl ether, neopentyl glycol diglycidyl ether, 1,2-epoxy-4-vinyl. Cyclohexane, 1-methyl-4- (2-methyloxiranyl) -7-oxabicyclo [4.1.0] heptane, xylylenebisoxetane, 3-ethyl-3 {[(3-ethyloxetane-3 -Yl) methoxy] methyl} oxetane and the like.
The above materials may be used alone or in combination of two or more.

  When the polymerizable monomer is used, the content of the polymerizable monomer is preferably 5 to 80% by mass based on the total solid content of the ink composition from the viewpoint of curability of the ink composition.

[Photopolymerization initiator]
Moreover, when using a polymerizable monomer, it is preferable to use together a photoinitiator. The photopolymerization initiator may be a photoradical polymerization initiator or a photocationic polymerization initiator, and the type thereof is not limited. By including a photopolymerization initiator, a printed matter formed from the ink composition can be cured by irradiation with ultraviolet rays.

  As the photo radical polymerization initiator, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1 -Hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl]- Acetophenone compounds such as 1- [4- (4-morpholinyl) phenyl] -1-butanone or 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one; benzoin; Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether Benzoin compounds such as tellurium or benzyl dimethyl ketal; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, or 3,3 Benzophenone compounds such as', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, or 2,4- Thioxanthone compounds such as diethylthioxanthone; 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- ( -Methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (Trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine , 2- (4-Methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, or 2,4-trichloro. Triazine compounds such as methyl- (4'-methoxystyryl) -6-triazine; 1,2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (O-beta) Oxime oxime)], or oxime ester compounds such as ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime); Phosphine compounds such as bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide or 2,4,6-trimethylbenzoyldiphenylphosphine oxide; quinones such as 9,10-phenanthrenequinone, camphorquinone and ethylanthraquinone System compounds; borate compounds; carbazole compounds; imidazole compounds; or titanocene compounds.

  Examples of commercially available acetophenone compounds include "Omnirad 907" (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one) manufactured by IGM Resins BV. Omnirad 369 "(2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone)," Omnirad 379 "2-benzyl-2. -Dimethylamino-1- (4-morpholinophenyl) -butan-1-one; a commercially available product of the phosphine compound is "Omnirad 819" (bis (2,4,6) manufactured by IGM Resins BV. -Trimethylbenzoyl) phenylphosphine oxide), "Omnirad TPO H" (2,4,6-trimethyl Emissions benzoyl diphenyl phosphine oxide) and the like.

  As the cationic photopolymerization initiator, diphenyliodonium hexafluorophosphate, iodonium salt such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, tri-p-tolylsulfonium hexafluorophosphate, triphenyl Examples thereof include sulfonium salts such as sulfonium tetrafluoroborate.

Examples of commercially available iodonium salt compound, manufactured by Fuji Film Wako Pure Chemical Co. "WPI-113" (bis [4- (alkyl _C 10 _{-C 13)} phenyl] iodonium hexafluorophosphate), "WPI-116" (bis [4- (alkyl _C 10 _{-C 13)} phenyl] iodonium hexafluoroantimonate), "WPI-169" (bis [4-tert-butylphenyl] iodonium bi spelling perfluorobutane sulfonyl Louis bromide), "WPI-170" Bis [4-tert-butylphenyl] iodonium hexafluorophosphate), “WPI-124” (bis [4- (alkylC ₁₀ -C ₁₃ ) phenyl] iodonium tetrakispentafluorophenylborate); commercially available sulfonium salt compounds As a product, Sanup (B) CPI-100P (triarylsulfonium hexafluorophosphate), CPI-101A (triarylsulfonium hexafluoroantimonate), CPI-310BP (triarylsulfonium tetrakispentafluorophenylborate) manufactured by BASF Corporation. "Irgacure 290" (tetrakispentafluorophenyl borate) and the like can be mentioned.

  These photopolymerization initiators may be used singly or as a mixture of two or more kinds at an arbitrary ratio as needed.

[Crosslinking agent]
When a resin or a polymerizable monomer is used, a crosslinking agent may be used together. The inclusion of the crosslinking agent improves the scratch resistance and chemical resistance of the coating film. Further, the temperature for thermosetting using a resin or a polymerizable monomer and a crosslinking agent may be 300 ° C or lower, 230 ° C or lower, or 180 ° C or lower. , 150 ° C. or lower.
Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, aldehyde crosslinking agents, amine crosslinking agents, and metal chelate crosslinking agents. Moreover, you may utilize the crosslinking agent and crosslinking reaction as described in "Crosslinking agent handbook" edited by Shinzo Yamashita et al. (Taiseisha, 1981).
These cross-linking agents may be used alone or in combination of two or more kinds.

   Examples of the isocyanate cross-linking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, and hexamethylene diisocyanate. , Diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and polyisocyanate compounds thereof. Examples thereof include adducts with a polyol compound such as trimethylolpropane, and burettes and isocyanurates of these polyisocyanate compounds.

  Examples of the epoxy-based cross-linking agent include bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, Examples thereof include trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, and diglycerol polyglycidyl ether.

  Examples of the aziridine-based crosslinking agent include tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, and N, N′-diphenylmethane-4,4 ′. -Bis (1-aziridinecarboxamide), N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide) and the like.

  Examples of the melamine-based cross-linking agent include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaptoxymethylmelamine, hexapentyloxymethylmelamine, hexahexyloxymethylmelamine, and melamine resin.

  Examples of the aldehyde-based cross-linking agent include glyoxal, malondialdehyde, succindialdehyde, maleindialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, benzaldehyde and the like.

  Examples of the amine-based crosslinking agent include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resin, and polyamide.

  Examples of the metal chelate cross-linking agent include acetylacetone and acetoacetyl ester coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium. Be done.

  The content of the crosslinking agent is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and particularly preferably 0.1 to 2% by mass based on the total solid content of the ink composition. %. When the content is within the above range, a coating film having good scratch resistance and chemical resistance can be formed. Further, the viscosity of the composition falls within the appropriate viscosity range of the inkjet head, and it is possible to prevent clogging of the head and deterioration of dischargeability.

<Solvent>
The ink composition of the present invention may contain a solvent capable of dispersing or dissolving the above-mentioned composition in order to lower the viscosity, improve the wettability and spreadability on a substrate, and the like. The type is not particularly limited, and examples thereof include alkylene glycol monoalkyl ethers, alkylene glycol alkyl ether acetates, aromatic hydrocarbons, ketones, lower and higher alcohols, cyclic esters and the like.
More specifically, as the solvent, alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether; diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene Diethylene glycol monoalkyl ethers such as chrycol monobutyl ether; Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether; triethylene glycol monomethyl ether, triethylene glycol monoether Triethylene glycol monoalkyl ethers such as triethylene glycol monobutyl ether; triethylene glycol dialkyl ethers such as triethylene glycol dimethyl ether and triethylene glycol diethyl ether; tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetra Tetraethylene glycol monoalkyl ethers such as ethylene glycol monobutyl ether; tetraethylene glycol dialkyl ethers such as tetraethylene glycol dimethyl ether and tetraethylene glycol diethyl ether; methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate, propylene glycol Alkylene glycol alkyl ether acetates such as monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methoxybutyl acetate and methoxypentyl acetate; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; Ketones such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, cyclohexanone; alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, glycerin; ethyl 3-ethoxypropionate, 3-methoxypropionic acid Esters such as methyl; cyclic esters such as γ-butyrolactone and ε-caprolactone It is below.

  The solvent can be selected depending on the application, and in the case of an inkjet ink, it is selected from the viewpoints of solubility for quantum dots and resin, swelling action for device members, viscosity and drying property at a nozzle, and the boiling point is preferably 100. ℃ or more, more preferably 130 ℃ or more. These solvents may be used alone or in combination of two or more.

  The content of the solvent is appropriately selected in consideration of the dispersion stability of the ink composition and the easiness of the process (eg, coating property) in the manufacturing process.

<Polymerization inhibitor>
The ink composition contains aluminum of 4-methoxyphenol, hydroquinone, methylhydroquinone, t-butylhydroquinone, 2,5-t-butyl-4-methylphenol, phenothiazine, and N-nitrosophenylhydroxylamine in order to enhance storage stability. A polymerization inhibitor such as salt may be included. The content of the polymerization inhibitor is preferably 0.01 to 0.1 part by mass with respect to the total solid content of the ink composition, from the viewpoint of enhancing the stability while maintaining the curability.

<Other ingredients>
In the ink composition, additives such as a surface conditioner, a leveling agent, an ultraviolet absorber or an antioxidant can be used, if necessary, in order to enhance printability and print resistance.

<Filtration>
The ink composition is preferably filtered with a filter in order to suppress the generation of foreign matter due to particle aggregation in the coating film formed from the composition and to maintain the smoothness of the coating film. The pore size of the filter is preferably 5 μm or less, more preferably 3 μm or less.

<Inkjet ink>
When the ink composition is used as an inkjet ink, the viscosity at 25 ° C. is preferably 5 to 100 mPa · s. In this viscosity range, stable ejection characteristics are exhibited from a commonly used head having a frequency of 4 to 10 KHz to a high frequency head of 10 to 50 KHz. When the viscosity is 5 mPa · s or more, deterioration of ejection followability is not observed in a high frequency head, which is preferable. When it is 100 mPa · s or less, the ejection property is good and the ejection stability is excellent, which is preferable.

  When the ink composition is used as an inkjet ink, the ink composition is supplied to a printer head of a printer for inkjet recording system, ejected from the printer head onto a substrate, and then a solvent drying step, or ultraviolet ray or electron beam, etc. A coating film can be formed on the print medium through the step of irradiating the active energy ray.

When solvent drying is performed, the drying temperature and the drying time are not particularly limited as long as the solvent can be removed, and may be 100 ° C. or higher, 180 ° C. or lower, and air drying. The drying time may be 1 minute or longer, 10 minutes or longer, and 120 minutes or shorter. Within the above range, a coating film having sufficient strength can be obtained.
When ultraviolet rays are used as a light source of active energy rays, for example, a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet laser, an LED, or sunlight can be used. The exposure dose may be 100 mJ / cm ² or more and 2000 mJcm ² or less. A sufficiently strong coating film can be obtained under the above exposure conditions.

<Printed matter>
The printed matter of the present invention has a printed layer made of an ink composition on a substrate.
The base material is not particularly limited, and is a plastic base material such as polycarbonate, hard vinyl chloride, soft vinyl chloride, polystyrene, foam polystyrene, PMMA, polypropylene, polyethylene or PET, or a mixture or modified product thereof, high-quality paper, art paper, coated paper, cast Examples thereof include a paper base material such as coated paper and a metal base material such as glass or stainless steel.

<Color filter>
The ink composition of the present invention can be used to form a filter segment that constitutes a color filter. In particular, the inkjet method is more preferable than the photolithography method from the viewpoint of printing efficiency and cost.
The color filter of the present invention includes a red filter segment, a green filter segment, and a blue filter segment, and may further include a magenta color filter segment, a cyan color filter segment, or a yellow filter segment. It may be formed of the ink composition of the invention.

  When a color filter is manufactured using the ink composition of the present invention, a black matrix can be formed in advance before forming each color filter segment on a transparent substrate or a reflective substrate. As the black matrix, chromium, a chromium / chromium oxide multilayer film, an inorganic film such as titanium nitride, or a resin film in which a light shielding agent is dispersed is used, but the black matrix is not limited thereto. It is also possible to previously form a thin film transistor (TFT) on the transparent substrate or the reflective substrate, and then form each color filter segment. Further, an overcoat film, a transparent conductive film, or the like may be formed on the color filter of the present invention, if necessary.

  The color filter of the present invention can be used for manufacturing a color solid-state image pickup device, an organic EL display device, a quantum dot display device, electronic paper, etc. in addition to a color liquid crystal display device.

<Light wavelength conversion layer>
The layer (coating film) formed using the ink composition of the present invention can be used as a light wavelength conversion layer. The light wavelength conversion layer is capable of converting excitation light into fluorescence on the longer wavelength side and emitting it, and for example, obtaining green or red fluorescence by using blue or ultraviolet light as excitation light, ultraviolet light or visible light. Fluorescence in the near infrared region can be obtained by using light as excitation light.
The thickness of the light wavelength conversion layer is preferably 1 to 500 μm, more preferably 1 to 50 μm, and further preferably 1 to 10 μm. When the thickness is 1 μm or more, a high wavelength conversion effect can be obtained, which is preferable. Further, it is preferable that the thickness is 500 μm or less because the light source unit can be thinned when incorporated in the light source unit.

<Light wavelength conversion member>
A light wavelength conversion member can also be formed by using the above-mentioned light wavelength conversion layer.
The light wavelength conversion member is a member in which the above-mentioned light wavelength conversion layer is formed on at least one surface of a specific base material. The base material is not particularly limited, and is a plastic base material such as polycarbonate, hard vinyl chloride, soft vinyl chloride, polystyrene, foam polystyrene, PMMA, polypropylene, polyethylene or PET, or a mixture or modified product thereof, high-quality paper, art paper, coated paper, cast Examples include paper base materials such as coated paper, and metal base materials such as glass or stainless steel.
The base material is selected according to the application, and if it is an application such as a prepaid card or a traffic card, a plastic base material or a mixture or modified product thereof is preferable from the viewpoint of durability. For use as a one-dimensional bar code, two-dimensional bar code, or QR code (registered trademark) (matrix type two-dimensional code) as an information recording medium, a paper base material is preferably used in addition to the plastic base material. A transparent substrate is preferred for use as a wavelength conversion color filter.

<Light emitting element>
The layer formed using the ink composition can be used as a light emitting layer in a light emitting element. The light emitting element has a substrate, a cathode and an anode provided on the substrate, a light emitting layer is provided between both electrodes, and a charge transport layer is provided on at least one of the cathode and the anode. Further, due to the property of the light emitting device, at least one of the anode and the cathode is transparent.
As a mode of stacking the light emitting element, a mode in which a hole transport layer, a light emitting layer, and an electron transport layer are sequentially stacked from the anode side is preferable. Further, a charge blocking layer or the like may be provided between the hole transport layer and the light emitting layer or between the light emitting layer and the electron transport layer. A hole injection layer may be provided between the anode and the hole transport layer, and an electron injection layer may be provided between the cathode and the electron transport layer. The light emitting layer may be a single layer, or the light emitting layer may be divided into a first light emitting layer, a second light emitting layer, a third light emitting layer, and the like. Further, each layer may be divided into a plurality of secondary layers.

<Substrate>
As the substrate, for example, a substrate used for a known organic EL element can be used. The substrate may be a resin film or a gas barrier film, and may be, for example, JP2004-136466A, JP2004-148566A, JP2005-246716A, JP2005-262529A. The gas barrier film described in 1 above can also be preferably used.
The thickness of the substrate is not particularly limited, but is preferably 30 μm to 700 μm, more preferably 40 μm to 200 μm, and further preferably 50 μm to 150 μm. Further, in any case, the haze is preferably 3% or less, more preferably 2% or less, still more preferably 1% or less, and the total light transmittance is preferably 70% or more, more preferably 80% or more, further preferably 90%. That is all.

<Anode>
The anode is generally required to have a function as an electrode for supplying holes to the organic compound or inorganic compound layer, and there is no particular limitation on the shape, structure, size or the like, and the application and purpose of the light emitting device. According to the above, it can be appropriately selected from known electrode materials. As mentioned above, the anode is usually provided as a transparent anode. The transparent anode is described in detail in “New Development of Transparent Electrode Film” supervised by Yutaka Sawada, published by CMC (1999). When a plastic substrate having low heat resistance is used as the substrate, ITO, IZO or IGZO is used, and a transparent anode formed at a low temperature of 150 ° C. or lower is preferable.

<Cathode>
The cathode usually has a function as an electrode for injecting electrons into an organic compound or an inorganic compound layer, and there is no particular limitation on its shape, structure, size, etc. Accordingly, it can be appropriately selected from known electrode materials.
Examples of the material forming the cathode include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Specific examples include Group 2 metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, lithium-aluminum alloys, magnesium-silver alloys, rare earth metals such as indium and ytterbium. These may be used singly, but from the viewpoint of achieving both stability and electron injectability, two or more may be preferably used in combination.

  Among these, as a material forming the cathode, a material mainly containing aluminum is preferable. The material mainly composed of aluminum means aluminum alone or an alloy of aluminum and 0.01 to 100% by mass of an alkali metal or a Group 2 metal (for example, lithium-aluminum alloy, magnesium-aluminum alloy, etc.). The material of the cathode is described in detail in JP-A-2-15595 and JP-A-5-121172. In addition, a dielectric layer made of an alkali metal or Group 2 metal fluoride, oxide or the like may be inserted between the cathode and the organic compound or inorganic compound layer to a thickness of 0.1 to 5 nm. This dielectric layer can also be regarded as a kind of electron injection layer.

  The thickness of the cathode can be appropriately selected depending on the material forming the cathode and cannot be specified unconditionally, but is usually about 10 nm to 5 μm, preferably 50 nm to 1 μm. Further, the cathode may be transparent or opaque. The transparent cathode can be formed by forming a thin film of the cathode material to a thickness of 1 to 10 nm and further stacking a transparent conductive material such as ITO, IZO or IGZO.

<Light emitting layer>
The light-emitting layer receives holes from the anode, the hole injection layer or the hole transport layer and receives electrons from the cathode, the electron injection layer or the electron transport layer when an electric field is applied, and recombines the holes with the electrons. Is a layer having a function of providing and emitting light. The light emitting layer may be composed of only quantum dots, or may be composed of a mixed layer of quantum dots and a host material. The light emitting material may further contain a fluorescent light emitting material or a phosphorescent light emitting material, and the dopant may be one kind or two or more kinds. The host material is preferably a charge transport material. The host material may be one kind or two or more kinds, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed. Further, the light emitting layer may contain a material which has no charge transporting property and does not emit light. Further, the light emitting layer may be one layer or two or more layers, and each layer may emit light of different emission colors.

  Examples of the fluorescent material include, for example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, condensed aromatics. Compound, perinone derivative, oxadiazole derivative, oxazine derivative, aldazine derivative, pyraridine derivative, cyclopentadiene derivative, bisstyrylanthracene derivative, quinacridone derivative, pyrrolopyridine derivative, thiadiazolopyridine derivative, cyclopentadiene derivative, styrylamine derivative, di Representative of ketopyrrolopyrrole derivatives, aromatic dimethylidin compounds, metal complexes of 8-quinolinol derivatives and metal complexes of pyrromethene derivatives Various metal complexes are, polythiophene, polyphenylene, polyphenylene vinylene polymer compounds such as, compounds such as organic silane derivatives.

Examples of the phosphorescent material include complexes containing a transition metal atom or a lanthanoid atom.
The transition metal atom is not particularly limited, but preferably includes ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, and platinum, and more preferably rhenium, iridium, and platinum.
Examples of the lanthanoid atom include lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutecium. Among these lanthanoid atoms, neodymium, europium, and gadolinium are preferable.

  Examples of the ligand of the complex include, for example, G. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press Co., 1987, H. Yersin, "Photochemistry, Co., Ltd., Phosphochemistry Co., Ltd., 1987". Ligands and the like described in "Organometallic Chemistry-Basics and Applications-" published by Shokabo Co., Ltd. in 1982 can be cited.

  Examples of the host material contained in the light emitting layer include those having a carbazole skeleton, those having a diarylamine skeleton, those having a pyridine skeleton, those having a pyrazine skeleton, those having a triazine skeleton, and arylsilane skeletons. The materials that are included, and the materials exemplified in the later-described hole injection layer, hole transport layer, electron injection layer, and electron transport layer are mentioned.

<Hole injection layer, hole transport layer>
The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. It may be an organic compound or an inorganic compound as long as it has the above-mentioned function, and may be a low molecular compound, a high molecular compound or a metal oxide. Specifically, the hole injection layer and the hole transport layer include carbazole derivative, triphenylamine derivative, triazole derivative, oxazole derivative, oxadiazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative, pyrazolone derivative, and phenylene. Diamine derivative, arylamine derivative, amino-substituted chalcone derivative, styrylanthracene derivative, fluorenone derivative, hydrazone derivative, stilbene derivative, silazane derivative, aromatic tertiary amine compound, styrylamine compound, aromatic dimethylidyne compound, porphyrin compound, Phthalocyanine compounds, low molecular weight compounds such as organosilane derivatives, carbon compounds such as carbon and fullerene, inorganic compounds consisting of metal oxides such as vanadium pentoxide and molybdenum trioxide Polyvinylcarbazole, polypyrrole, poly (3,4-ethylenedioxythiophene) - it is preferably a layer containing a polymer compound such as poly (styrenesulfonic acid) (PEDOT-PSS).

<Electron injection layer, electron transport layer>
The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injection layer, the electron transport layer, specifically, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, Aromatic ring tetracarboxylic acid anhydrides such as carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene and perylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles as ligands and various metal complexes typified by metal complexes of a low molecular compounds such as organic silane derivatives, zinc oxide (ZnO), organic was metal oxide or alkali metal doping such as titanium oxide (TiO ₂₎ walk It is preferably a layer containing an inorganic compound.

<Hole blocking layer>
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. In the present invention, a hole blocking layer can be provided as an organic compound layer adjacent to the light emitting layer on the cathode side. The electron transport layer / electron injection layer may also have the function of the hole blocking layer.
Examples of organic compounds forming the hole blocking layer include aluminum complexes such as BAlq, triazole derivatives, and phenanthroline derivatives such as BCP. Further, a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side can be provided at a position adjacent to the light emitting layer on the anode side. The hole transport layer / hole injection layer may also have this function.

<Light emitting device>
A light wavelength conversion member and a light emitting element can be combined and used as a light emitting device. In the light emitting device, at least one of the light wavelength converting layer of the light wavelength converting member and the light emitting layer of the light emitting element may be formed using the ink composition of the present invention.
The light wavelength conversion member converts the excitation light into fluorescence on the long wavelength side and emits it. For example, it converts blue or ultraviolet light into green or red fluorescence, or converts ultraviolet light or visible light into near infrared light. It can be converted into fluorescence of the area. The light wavelength conversion member is not particularly limited as long as it maintains the relationship between the excitation light wavelength and the emission fluorescence wavelength, and an optimum one can be appropriately selected.
As a light source of a conventionally known light emitting element, a semiconductor light emitting element such as a light emitting diode (LED) or a semiconductor laser (LD); organic electroluminescence (organic EL); or quantum dots can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the following examples do not limit the scope of rights of the present invention. Unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass".

  First, a method for measuring the average particle diameter of the core of the quantum dots (core / shell type), the average particle diameter of the organic fine particles (B) and the average primary particle diameter of the metal oxide fine particles (C) will be described.

<Measurement of average particle size of quantum dot (core / shell type) core>
The quantum dot (A) solution described below is diluted about 100 times with methoxypropyl acetate, and the diluted solution is cast on an electron microscope grit (product name: grid Cu150 mesh with a support film) and dried at room temperature for 15 hours or more. It was Using a scanning transmission electron microscope (JEM2800 manufactured by JEOL Ltd.), measurement was performed at an accelerating voltage of 200 kV and an observation magnification of 2,000,000 times, and the particle size of the core was determined from the obtained image. The average value of 10 quantum dot particles was defined as the average particle diameter.

<Average particle size of organic fine particles (B)>
The average particle diameter of the organic fine particles (B) was measured using "Nanotrack UPA" manufactured by Nikkiso Co., Ltd. A few drops of the organic fine particle (B) dispersion liquid having a solid content concentration adjusted to 20% by mass was dropped into a cell filled with the same solvent as the dispersion liquid, and measurement was carried out at a concentration at which the signal level reached an optimum value.

<Average primary particle diameter of metal oxide fine particles (C)>
The average primary particle diameter of the metal oxide fine particles (C) is diluted about 100 times with each of the metal oxide fine particle (C) dispersions, and the diluted liquid is used as a grit for an electron microscope (product name: with a supporting film). (Cu grid 150 mesh) and dried at room temperature for 15 hours or more. Using a scanning electron microscope (JEM2800 manufactured by JEOL Ltd.), measurement was performed at an accelerating voltage of 200 kV and an observation magnification of 2,000,000 times, and the average value of 50 points of the metal oxide fine particles (C) was defined as the average particle diameter.

<Production of quantum dots (A)>
(Quantum dot dispersion (A-1))
0.55 parts of anhydrous zinc acetate, 7.0 parts of dodecanethiol, and 5.0 parts of oleylamine were heated and dissolved to prepare an additive solution. 0.22 parts of indium chloride and 8.25 parts of octylamine were placed in a reaction vessel and heated to 165 ° C. while performing nitrogen bubbling. After the indium chloride was dissolved, 0.86 part of dimethylaminophosphine was injected in a short time, and the temperature was controlled to 165 ° C. for 20 minutes. After that, it was rapidly cooled to 40 degrees. After pouring the above-mentioned addition liquid and heating at 240 ° C. for 2 hours, it was allowed to cool to room temperature. After cooling, it was purified by a reprecipitation method using hexane and ethanol to obtain quantum dots (0-1) of InP (core) / ZnS (shell).
Subsequently, the obtained quantum dots (0-1) were diluted to a solid content concentration of 1% in toluene, and the same amount of 5% 6- (diethylamino) -1,3,5-triazine-2,4-dithiol was added. Toluene solution was added and stirred for 12 hours. Purification was performed by reprecipitation using toluene and ethanol, and the solid content concentration was adjusted to 20% with ethylene glycol monobutyl ether acetate, and 6- (diethylamino) -1,3,5-triazine-2,4-dithiol was prepared. A quantum dot dispersion liquid (A-1) surface-treated with was obtained.
The average particle size of the quantum dot core was 7 nm, which was determined from an electron microscope image of the quantum dot dispersion liquid (A-1).

(Quantum dot dispersion (A-2))
The quantum dots (0-1) were diluted to a solid content concentration of 1% in toluene, and the same amount of 2.5% 6- (diethylamino) -1,3,5-triazine-2,4-dithiol toluene solution was added. And stirred for 12 hours. Purification was carried out by reprecipitation using toluene and ethanol, the solid content concentration was adjusted to 20% with methoxypropyl acetate, and the surface was adjusted with 6- (diethylamino) -1,3,5-triazine-2,4-dithiol. A treated quantum dot dispersion liquid (A-2) was obtained.
The average particle diameter of the quantum dot core was 7 nm, which was determined from an electron microscope image of the quantum dot dispersion liquid (A-2).

(Quantum dot dispersion (A-3))
After purification by reprecipitation method using toluene and ethanol, dipropylene glycol diacrylate (“APG-100” manufactured by Shin Nakamura Chemical Co., Ltd.) was used instead of ethylene glycol monobutyl ether acetate to obtain a solid content concentration of 60%. Quantum dot dispersion (A-) surface-treated with 6- (diethylamino) -1,3,5-triazine-2,4-dithiol (A-) in the same manner as quantum dot dispersion (A-1) except that it was adjusted. 3) was obtained.
The quantum dots in the quantum dot dispersion liquid (A-3) were InP (core) / ZnS (shell), and the average particle diameter of the quantum dot core was 7 nm.

<Production of organic fine particles (B)>
(Organic fine particle dispersion (B-1))
Under a nitrogen atmosphere, 50 parts of trifluoroethylmethacrylate, 40 parts of methyl methacrylate, 5 parts of allyl methacrylate and 5 parts of isobornyl methacrylate are added to 560 parts of water, stirred, and heated to 80 ° C. An aqueous solution prepared by dissolving 0.167 parts of 2-azobis (2-amidinopropane) dihydrochloride in a very small amount of water was added all at once, and polymerization was carried out at 80 ° C. for 8 hours. After the polymerization, ethylene glycol monobutyl ether was added, water was removed by stripping, and a solid content of 20% by mass was obtained to obtain an organic fine particle dispersion liquid (B-1) which is an acrylic resin fine particle having a fluorine substituent. ..
The average particle size of the organic fine particles in the obtained organic fine particle dispersion liquid (B-1) was 280 nm.

(Organic fine particle dispersion (B-2 to 4))
Acrylic resin fine particles having a fluorine substituent in the same manner as in the organic fine particle dispersion (B-1), except that the solvent composition and the monomer composition were changed to the composition and the blending amount (parts) shown in Table 1. Organic fine particle dispersions (B-2 to 4) were obtained. Table 1 shows the average particle size of the obtained organic fine particle dispersion.

(Organic fine particle dispersion (B-5))
In 80 parts of ethylene glycol monobutyl ether acetate, 16.0 parts of Eposter S (manufactured by Nippon Shokubai Co., Ltd., melamine-formaldehyde condensate, average particle size 200 nm) and 4.0 parts of BYK-111 (manufactured by Big Chemie Co., Ltd.) Glass beads (particle diameter: 850-1180 μm) were added and dispersed for 2 hours using a paint conditioner to obtain an organic fine particle dispersion liquid (B-5), which is melamine resin fine particles.
The average particle size of the organic fine particles in the obtained organic fine particle dispersion liquid (B-5) was 175 nm.

(Organic fine particle dispersion (B-6))
It is melamine resin fine particles in the same manner as the organic fine particle dispersion liquid (B-5), except that the eposter S is changed to the eposter FS (Nippon Shokubai Co., Ltd., melamine-formaldehyde condensate, average particle size 200 nm). An organic fine particle dispersion liquid (B-6) was obtained.
The average particle size of the organic fine particles in the obtained organic fine particle dispersion liquid (B-6) was 173 nm.

(Organic fine particle dispersion (B-7))
Acrylic resin fine particles were obtained in the same manner as the organic fine particle dispersion liquid (B-5), except that the eposter S was changed to MX-80H3wTM (crosslinked acrylic monodisperse particles manufactured by Soken Chemical Co., Ltd., average particle diameter 800 nm). Thus, an organic fine particle dispersion liquid (B-7) was obtained.
The average particle diameter of the organic fine particles in the obtained organic fine particle dispersion liquid (B-7) was 732 nm.

(Organic fine particle dispersion (B-8))
Organic fine particle dispersion except that Eposter S was changed to MX-80H3wTM (manufactured by Soken Chemical Industry Co., Ltd., crosslinked acrylic monodisperse particles, average particle diameter 800 nm) and BYK-111 was changed to BYK-2155 (manufactured by Big Chemie Co., Ltd.). In the same manner as in (B-5), an organic fine particle dispersion liquid (B-8), which is an acrylic resin fine particle, was obtained.
The average particle diameter of the organic fine particles in the obtained organic fine particle dispersion liquid (B-6) was 673 nm.

(Organic fine particle dispersion (B-9))
Under a nitrogen atmosphere, in 560 parts of water, 50 parts of trifluoroethyl methacrylate, 40 parts of methyl methacrylate, 5 parts of allyl methacrylate and 5 parts of isobornyl methacrylate were added, The mixture was stirred and heated to 80 ° C. After the temperature was raised, an aqueous solution prepared by dissolving 0.167 parts of 2,2-azobis (2-amidinopropane) dihydrochloride in a very small amount of water was added all at once, and polymerization was carried out at 80 ° C. for 8 hours. After the polymerization, the temperature was raised to remove water, and 90 parts of light scattering particles (B-9P) were obtained. Then, 7.5 parts of the obtained light scattering particles (B-9P), 0.75 part of BYK-2155 (manufactured by Big Chemie Co., Ltd.), dipropylene glycol diacrylate ("APG-100" manufactured by Shin-Nakamura Chemical Co., Ltd.) 4.25 parts were mixed, 75 parts of zirconia beads (particle size 1.25 mm) were added, and the mixture was stirred for 80 minutes with a paint shaker. After stirring, the zirconia beads were removed to obtain a fluorine-substituted organic fine particle dispersion liquid (B-9) having a solid content concentration of 60%. The average particle size of the obtained light scattering particles was 280 nm.

(Organic fine particle dispersion (B-10))
In 6.6 parts of dipropylene glycol diacrylate ("APG-100" manufactured by Shin-Nakamura Chemical Co., Ltd.), 10 parts of Eposter S (manufactured by Nippon Shokubai Co., Ltd., melamine-formaldehyde condensate, average particle size 200 nm), BYK- 0.1 part of 111 (manufactured by Big Chemie Co., Ltd.) was added, zirconia beads (particle size: 1.25 mm) were added, and dispersion treatment was performed for 2 hours using a paint conditioner to contain melamine resin fine particles having a solid content concentration of 60%. Thus, an organic fine particle dispersion liquid (B-10) was obtained.
The average particle size of the organic fine particles in the obtained organic fine particle dispersion liquid (B-10) was 175 nm.

<Production of metal oxide fine particles (C)>
(Metal oxide fine particle dispersion (C-1))
In 60 parts of ethylene glycol monobutyl ether acetate, 20 parts of MT700B (manufactured by Teika Co., Ltd., fine particle titanium oxide, average primary particle size 80 nm) and 20 parts of BYK-2155 (manufactured by Big Chemie Co., Ltd.) were blended, and glass beads (particles were used. (Diameter: 850-1180 μm) was added, and the dispersion treatment was performed for 2 hours using a paint conditioner to obtain a metal oxide fine particle dispersion liquid (C-1).
The average primary particle diameter of the metal oxide fine particles in the obtained metal oxide fine particle dispersion liquid (C-1) was 84 nm.

(Metal oxide fine particle dispersion (C-2))
The metal oxide fine particle dispersion liquid (C-1) was prepared in the same manner as the metal oxide fine particle dispersion liquid (C-1) except that the MT700B was changed to MT600B (manufactured by TAYCA CORPORATION, fine particle titanium oxide, average primary particle diameter 50 nm). -2) was obtained.
The average primary particle diameter of the metal oxide fine particles in the obtained metal oxide fine particle dispersion liquid (C-2) was 50 nm.

(Metal oxide fine particle dispersion (C-3))
A metal oxide was obtained in the same manner as the metal oxide fine particle dispersion liquid (C-1) except that MT700B was changed to MT600SA (manufactured by TAYCA Corporation, Si, Al treatment, fine particle titanium oxide, average primary particle diameter 50 nm). A fine particle dispersion (C-3) was obtained.
The average primary particle diameter of the metal oxide fine particles in the obtained metal oxide fine particle dispersion liquid (C-3) was 50 nm.

(Metal oxide fine particle dispersion (C-4))
In 60 parts of ethylene glycol monobutyl ether acetate, 20 parts of JR603 (manufactured by Teika Ltd., Si, Al treatment, fine titanium oxide particles, average primary particle diameter 250 nm) and 20 parts of BYK-2155 (manufactured by Big Chemie Co., Ltd.) were blended. , Glass beads (particle diameter: 850-1180 μm) were added, and a dispersion treatment was performed for 2 hours using a paint conditioner to obtain a metal oxide fine particle dispersion liquid (C-4).
The average primary particle diameter of the metal oxide fine particles in the obtained metal oxide fine particle dispersion liquid (C-4) was 250 nm.

(Metal oxide fine particle dispersion (C-5))
In 13.1 parts of dipropylene glycol diacrylate (“APG-100” manufactured by Shin-Nakamura Chemical Co., Ltd.), 20 parts of MT600SA (manufactured by Teika Co., Ltd., fine titanium oxide particles, average primary particle diameter 80 nm), BYK-2155 (Big Chemie) 0.2 parts by weight), glass beads (particle size: 850-1180 μm) were added, and a dispersion treatment was performed for 3 hours using a paint conditioner to obtain a metal oxide fine particle dispersion liquid (C-5). It was
The average primary particle diameter of the metal oxide fine particles in the obtained metal oxide fine particle dispersion liquid (C-5) was 84 nm.

<Production of binder component (D)>
(Binder resin solution (Dp-1))
Acrylic resin "John Cryl 819" manufactured by BASF was adjusted with ethylene glycol monobutyl ether acetate so as to be 30% by mass to obtain a binder resin solution (Dp-1).

(Binder resin solution (Dp-2))
Acrylic resin "John Cryl 586" manufactured by BASF was adjusted with ethylene glycol monobutyl ether acetate so as to be 30% by mass to obtain a binder resin solution (Dp-2).

<Production of ink composition (inkjet ink)>
[Example 1]
(Ink composition (I-1))
45.0 parts of quantum dot dispersion liquid (A-1), 3.6 parts of organic fine particle dispersion liquid (B-1), 5.0 parts of metal oxide fine particle dispersion liquid (C-1), binder resin solution (Dp- 1) 14.8 parts and 31.6 parts of ethylene glycol monobutyl ether acetate were weighed, then sealed and stirred, and filtered using a membrane filter having a pore size of 1 μm to obtain a composition (I-1).

[Examples 2 to 28, Comparative Examples 1 to 9]
(Composition (I-2 to 37))
Compositions (I-2 to 37) were obtained in the same manner as the composition (I-1) except that the composition and the compounding amount shown in Table 2 were changed.

The abbreviations in Table 2 are shown below.
-Dm-1: diethyl acrylamide-Dm-2: dipropylene glycol diacrylate-BGAc: ethylene glycol monobutyl ether acetate-ε-CL: ε-caprolactone-1, 4-BDDA: 1,4-butanediol diacetate-Omnirad 907 : 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one. Omnirad819: bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide Kayacure DETX-S: 2. 4-diethylthioxanthen-9-one

<Evaluation of ink composition>
The following evaluations were performed on the obtained compositions (I-1 to 37). The results are shown in Table 3.

(Redispersibility)
After 100 mL of the composition was set aside in a screw tube bottle having a transparent side surface (capacity: about 150 mL), the composition was allowed to stand in a 25 ° C. environment for 3 days to allow the composition to settle. After that, the mixture was stirred with a paint shaker, the time until the precipitate was dispersed was visually confirmed, and evaluated according to the following criteria. The composition containing the polymerizable monomer was evaluated in a yellow room environment.
◯: Time until the sediment is dispersed visually is less than 1 minute (good)
Δ: Time to visually disperse the sediment is 1 minute or more and less than 5 minutes (usable)
X: Visually the time until the precipitate is dispersed is 5 minutes or more (unusable)

(Excitation light transmittance)
The composition was applied to a transparent film (polyester film Lumirror 75S10 manufactured by Toray Industries, Inc.) so as to have a film thickness of 6.0 μm after drying using a bar coater. The composition containing no polymerizable monomer was dried in an environment of 100 ° C. to form a film, and the composition containing a polymerizable monomer was measured by using an LED irradiator installed in a nitrogen-substituted glove box to obtain an integrated light amount of 500 mJ. / Cm ² (UVA conversion) was irradiated to form a cured film. The excitation light transmittance of the obtained coating film was measured using QE-2000 manufactured by Otsuka Electronics Co., Ltd., and evaluated according to the following criteria. The excitation wavelength was 450 nm.
A: Less than 10% (very good)
◯: 10% or more and less than 20% (good)
△: 20% or more and less than 30% (usable)
×: 30% or more (cannot be used)

(External quantum efficiency (EQE))
The composition was applied to a transparent film (polyester film Lumirror 75S10 manufactured by Toray Industries, Inc.) so as to have a film thickness of 6.0 μm after drying using a bar coater. The composition containing no polymerizable monomer was dried in an environment of 100 ° C. to form a film, and the composition containing a polymerizable monomer was measured by using an LED irradiator installed in a nitrogen-substituted glove box to obtain an integrated light amount of 500 mJ. / Cm ² (UVA conversion) was irradiated to form a cured film. The external quantum efficiency (EQE) of the obtained coating film was measured using QE-2000 manufactured by Otsuka Electronics Co., Ltd. and evaluated according to the following criteria. The excitation wavelength was 450 nm, and the integral range of the fluorescence wavelength was 500 nm to 800 nm.
◎: 20% or more (very good)
◯: 15% or more and less than 20% (good)
△: 10% or more and less than 15% (usable)
X: less than 10% (cannot be used)

According to Table 3, the ink composition of the present invention was excellent in redispersibility, suppressed the transmittance of excitation light, and showed high luminous efficiency. Furthermore, when the ratio of the organic fine particles (B) and the metal oxide fine particles (C) is in a particularly preferable range (0.4 or more and less than 0.8), the excitation light transmittance is suppressed and the luminous efficiency is very high. Since it is good, it has excellent color purity (Examples 6, 16, 17, 20, 21, 23 to 25, 27, 28).
On the other hand, the organic fine particles (B) are effective in terms of redispersibility and light emission efficiency, but since the excitation light transmittance is insufficiently suppressed, it is difficult to increase the color purity even if the light emission efficiency is high. (Comparative example 1-3).
The metal oxide fine particles (C) are expected to improve the luminous efficiency and suppress the escape of excitation light due to the white color by increasing the addition amount, but since they have a large specific gravity, sedimentation and aggregation easily occur and re-separation occurs. Compatibility with acidity is difficult (Comparative Example 4-6). The same applies to metal oxide particles having a large average primary particle diameter (Comparative Example 7-9).
That is, the ink composition of the present invention, by containing the organic fine particles (B) and the metal oxide fine particles (C), simultaneously satisfies redispersibility, suppression of excitation light transmittance, and improvement of light emission efficiency, and high color purity. When the ((B) / (C)) ratio is 0.4 or more and less than 0.8, a particularly excellent effect is exhibited.

<Inkjet discharge evaluation 1>
When the obtained ink composition (I-6) was filled in a cartridge and inkjet printing was performed under the following conditions, it was confirmed that ink could be ejected without any problem and inkjet printing was possible.
<< Inkjet ejection conditions >>
Printer: DYMATIX MATERIALS PRINTER
Cartridge: Dymatix Materials Cartridges 10pL
Head drive voltage: 25V
Head drive temperature: 30 ℃
Base material: Glass substrate (Corning glass "Eagle 2000" 0.7 mm thick)

<Inkjet ejection evaluation 2>
When the obtained ink composition (I-27) was filled in a cartridge and inkjet printing was performed under the following conditions, it was confirmed that ink could be ejected without any problem and inkjet printing was possible.
<< Inkjet ejection conditions >>
Printer: DYMATIX MATERIALS PRINTER
Cartridge: Dymatix Materials Cartridges 10pL
Head drive voltage: 25V
Head drive temperature: 40 ° C
Base material: Glass substrate (Corning glass "Eagle 2000" 0.7 mm thick)

  Therefore, the ink composition of the present invention has inkjet ejection properties and can be used as an inkjet ink. Further, the printed matter obtained from the ink composition can be applied to a color filter or the like that exhibits high luminous efficiency.

<Reading evaluation 1 of printed matter>
Using the ink composition (I-20), a QR code (registered trademark) was printed on a white inkjet recording paper (Fuji Film Co., Ltd. Color Photographic Finish Pro). When the QR code (registered trademark) was read using a code reader under visible light, the recorded information could be read.

<Reading evaluation 2 of printed matter>
Using the ink composition (I-20), a QR code (registered trademark) was printed on a black carbon paper (High Touch Carbon Paper Black manufactured by General Corp.). When the QR code (registered trademark) was read using a code reader under visible light, the recorded information could not be read. Then, when the QR code (registered trademark) was irradiated with a black light having a wavelength of 365 nm, the pattern of the QR code (registered trademark) was visualized on the irradiation part, and the visualized QR code (registered trademark) was read by a code reader. Then, I was able to read the recorded information.

  The QR code (registered trademark) printed on a specific recording paper using the ink composition of the present invention cannot read the information recorded in the QR code (registered trademark) under visible light, but has a specific wavelength. Since the information can be read in the state where it is illuminated by the light source, it is possible to provide a printed matter with high security.

[Potential for industrial use]
The printed matter printed using the ink composition of the present invention can be suitably used for a color filter, a light wavelength conversion layer, a solar cell, a laser, a fluorescent marker, a sensor and the like. Furthermore, by utilizing the fluorescence response at a specific wavelength, it is possible to add security to the brand label, one-dimensional barcode, two-dimensional barcode, QR code (registered trademark), symbol mark, etc. By switching, it becomes possible to provide a printed material in which the multiplexed information can be read. Further, the ink composition of the present invention can be expected to have a remarkable effect that it has a higher color-developing property and a wider color gamut than the conventional phosphor-containing ink. Furthermore, when the ink composition of the present invention is used alone or in combination with existing CMYK inks, it becomes possible to emboss or convert a pattern by irradiation with a light beam having a specific wavelength.

Claims (11)

  An ink composition comprising quantum dots (A), organic fine particles (B), metal oxide fine particles (C) and a binder component (D).   The ink composition according to claim 1, wherein the content of the organic fine particles (B) is 2% by mass or more and 30% by mass or less based on the total solid content of the ink composition.   The ink composition according to claim 1 or 2, wherein the content of the metal oxide fine particles (C) is 2% by mass or more and 20% by mass or less based on the total solid content of the ink composition.   The mass ratio ((B) / (C)) of the organic fine particles (B) to the metal oxide fine particles (C) is 0.4 or more and less than 0.8. Ink composition.   The ink composition according to any one of claims 1 to 4, wherein the organic fine particles (B) include at least one kind of fine particles selected from the group consisting of melamine resin fine particles and acrylic resin fine particles.   The ink composition according to claim 1, wherein the metal oxide fine particles (C) have an average primary particle diameter of 30 to 100 nm.   The ink composition according to claim 1, wherein the metal oxide fine particles (C) are titanium oxide fine particles.   The quantum dot (A) is at least one element selected from the group consisting of Group 2 elements, Group 10 elements, Group 11 elements, Group 12 elements, Group 13 elements, Group 14 elements, Group 15 elements and Group 16 elements. The ink composition according to any one of claims 1 to 7, which is a compound semiconductor containing.   An inkjet ink comprising the ink composition according to claim 1.   A printed matter formed from the inkjet ink according to claim 9.   A color filter comprising a filter segment formed from the inkjet ink according to claim 9.