Optical conversion ink composition, optical conversion laminated substrate, backlight unit, optical conversion pixel substrate, and image display device

Abstract

To provide a light conversion ink composition which is superior in terms of light conversion properties and suitability for the continuous inkjet process.SOLUTION: A light conversion ink composition is provided, comprising luminescent particles and a polymerizable monomer, where the luminescent particles comprises a core containing Ag, In, Ga and S, and a shell containing at least two elements selected from In, Ga and S.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a light-converting ink composition, a light-converting laminated substrate manufactured using the same, and a light-converting pixel substrate.

Background Art

[0002] As the information society develops, the needs for display devices for displaying images are increasing in various forms. In recent years, various display devices such as liquid crystal display (LCD), plasma display panel (PDP), and organic light emitting diode display device (OLED) have been utilized.

[0003] Color reproducibility is one of the most important factors in display devices. Recently, as an example of a solution for enhancing the color reproducibility of display devices, a display device equipped with a light-converting laminated substrate containing quantum dots, which is another light-converting means, is used instead of a normal white LED by using a blue LED. For example, by applying a light-converting laminated substrate or a light-converting pixel substrate including a light-converting layer in which quantum dots are dispersed to a backlight or a color filter including a pixel using a blue LED chip to enhance the light-converting efficiency, the color reproducibility of the display device is attempted to be improved.

[0004] On the other hand, in order to manufacture a color filter to which a light-converting pixel is applied, a photolithography method using a composition containing light-emitting particles such as quantum dots can be used. However, although such a method is excellent in terms of the fineness and reproducibility of the color filter, in order to form pixels, coating, exposure, development, and curing processes are required for each color, respectively, increasing the manufacturing process, time, and cost, increasing the control factors between processes, and making it difficult to manage the yield.

[0005] To solve such problems, an inkjet method has been proposed. The inkjet method is a technique that uses an inkjet head to eject liquid ink onto predetermined positions that are partitioned, and realizes an image in which each ink is colored. It can color a plurality of colors including red, green, and blue at once, and can significantly reduce the manufacturing process, time, and cost.

[0006] In this regard, Korean Registered Patent Publication No. 10-1475520 discloses a technique related to an inkjet printing quantum dot ink composition, and Korean Registered Patent Publication No. 10-1628065 discloses a technique related to a composition containing a light-emitting complex. However, there are problems such as drastic changes in film thickness due to light conversion efficiency and jetting time, which are visually recognized as unevenness.

[0007] Therefore, there is a need to develop a light-converting ink composition that can form a light-converting laminated substrate and a light-converting pixel substrate with excellent light conversion efficiency and has excellent characteristics in the uniformity of the film thickness of the pattern.

Prior Art Documents

Patent Documents

[0008] Patent Document 1: Korean Registered Patent Publication No. 10-1475520 Patent Document 2: Korean Registered Patent Publication No. 10-1628065

Summary of the Invention

Problems to be Solved by the Invention

[0009] One object of the present invention is to provide a light-converting ink composition having excellent light conversion characteristics and continuous inkjet process.

[0010] Another object of the present invention is to provide a light-converting laminated substrate and a light-converting pixel substrate manufactured using the light-converting ink composition.

Means for Solving the Problems

[0011] In order to solve the above problems, the present invention provides a light-converting ink composition containing light-emitting particles and a polymerizable monomer, wherein the light-emitting particles include a core containing Ag, In, Ga, and S, and a shell containing at least two elements of In, Ga, and S.

[0012] The present invention also provides a light-converting laminated substrate and a light-converting pixel substrate manufactured using the light-converting ink composition.

Advantages of the Invention

[0013] When the light-converting ink composition according to the present invention is used, relatively high light-converting efficiency occurs, excellent luminance can be obtained, the change in film thickness due to jetting time is low, and a uniform pattern can be realized. Therefore, an excellent light-converting coating film without unevenness can be provided during the progress of the continuous process.

[0014] The present invention can be usefully applied to a backlight unit or a light-converting pixel substrate using the light-converting ink composition.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0016] The present invention provides a light-converting ink composition excellent in light-converting efficiency and jetting characteristics, and a light-converting laminated substrate and a light-converting pixel substrate manufactured using the same, by including light-emitting particles and a polymerizable monomer, and including a core and a shell containing the metal elements specified as the light-emitting particles.

[0017] Specifically, the present invention includes luminescent particles comprising a core containing Ag, In, Ga, and S and a shell containing at least two elements of In, Ga, and S, and has the property that absorption of blue light sources is improved, and is characterized in that the light conversion efficiency is improved. In particular, it includes a shell containing at least two elements of In, Ga, and S, enabling the realization of a narrow full width at half maximum and imparting excellent color purity characteristics.

[0018] In addition, a backlight unit manufactured using the light conversion ink composition of the present invention and / or an image display device including a light conversion pixel substrate has the advantage that when the full width at half maximum of the converted and emitted light is 40 nm or less, it has excellent color purity and can ensure a color reproducibility of 100% or more based on the NTSC color reproduction region.

[0019] Hereinafter, the present invention will be described in detail. <Light Conversion Ink Composition> The light conversion ink composition of the present invention includes luminescent particles and a polymerizable monomer, and may further include one or more of scattering particles, a photoinitiator, an additive, and a solvent.

[0020] Luminescent particles The luminescent particles can emit light having a wavelength different from the absorbed wavelength, for example, by absorbing light of a predetermined wavelength. The luminescent nanocrystal particles may be red luminescent particles that emit light (red light) having an emission peak wavelength in the range of 605 to 665 nm, green luminescent particles that emit light (green light) having an emission peak wavelength in the range of 500 to 600 nm, or blue luminescent particles that emit light (blue light) having an emission peak wavelength in the range of 420 to 480 nm. The light conversion ink composition of the present invention preferably contains at least one of the above luminescent particles.

[0021] In the present invention, the luminescent particles contain a semiconductor material, and examples thereof include quantum dots.

[0022] According to an embodiment of the present invention, the luminescent particles may have a ligand layer on the surface, and the ligand layer may contain a compound represented by the following Chemical Formula 1.

[0023]

Chem.

[0024] In Chemical Formula 1, A is -NH2 or -SH, R1 and R2 are each independently a direct bond or a C1-C12 alkylene group, R3 is a C1-C10 alkyl group, a C1-C10 alkenyl group, or a C4-C10 aryl group, L1 is TIFF0007717527000002.tif19114

[0025] and m and n are each independently an integer from 0 to 10, but are not 0 at the same time.

[0026] In one embodiment of the present invention, the compound represented by Chemical Formula 1 may be a compound represented by any one of the following Chemical Formulas 1-1 to 1-13.

[0027]

Chem.

[0028]

Chem.

[0029]

Chem.

[0030]

Chem.

[0031]

Chem.

[0032]

Chem.

[0033]

Chem.

[0034]

Chem.

[0035]

Chem.

[0036]

Chem.

[0037]

Chem.

[0038]

Chem.

[0039]

Chem.

[0040] In the present invention, the compound represented by Chemical Formula 1 is an organic ligand, which plays a role of coordinating to the surface of luminescent particles (quantum dots) to stabilize the quantum dots. Therefore, when the luminescent particles of the present invention have a ligand layer containing the compound represented by Chemical Formula 1 on the surface, excellent luminescent characteristics, light retention rate, and process characteristics can be exhibited.

[0041] Quantum dots produced conventionally generally have a ligand layer on the surface. Immediately after production, the ligand layer may consist of oleic acid, lauric acid, 2-(2-methoxyethoxy)acetic acid, 2-[2-(2-methoxyethoxy)ethoxy]acetic acid, and succinic acid mono-[2-(2-methoxy-ethoxy)-ethyl]ester. In this case, compared with the quantum dots of the present invention containing the compound represented by Chemical Formula 1 as the ligand layer, due to the weaker binding force between the ligand layer and the quantum dots and the unbound defects on the surface of the quantum dots, the surface protection effect may be reduced. Also, in the case of oleic acid, it is easily dispersed in saturated hydrocarbon solvents such as n-hexane, which is a highly volatile compound (VOC; volatile organic compound), and aromatic solvents such as chloroform and benzene, but has poor dispersibility in solvents and monomers (photopolymerizable compounds) such as PGMEA.

[0042] The quantum dots according to the present invention, by including the compound represented by Chemical Formula 1 in the ligand layer, not only exhibit excellent oxidation stability compared to conventional quantum dots due to the protection of the surface of the quantum dots, but also have extremely excellent dispersibility in monomers and have the effect of improving light characteristics.

[0043] Further, the quantum dots of the present invention exhibit excellent dispersibility not only in aromatic solvents such as chloroform but also in solvents such as PGMEA and can be applied during the production of QLED devices.

[0044] In some embodiments, the quantum dots according to the present invention include, in the ligand layer, the compound represented by the chemical formula 1, and may further include oleic acid, lauric acid, 2-(2-methoxyethoxy)acetic acid, 2-[2-(2-methoxyethoxy)ethoxy]acetic acid, and succinic acid mono-[2-(2-methoxy-ethoxy)-ethyl]ester, etc.

[0045] In one embodiment of the present invention, the quantum dots have a core-shell structure including a core and a shell covering at least a part of the core.

[0046] In the present invention, the core-shell structure may be a structure composed of a core and a first shell, for example, a core / shell structure, or may be a structure composed of a core, a first shell, and a second shell, that is, a core / shell / shell structure.

[0047] The core includes a four-element compound of silver (Ag), indium (In), gallium (Ga), and sulfur (S). For example, the core is AgInGaS. Such a core has the advantage that it can absorb a short-wavelength light source more efficiently and minimize the light absorption rate in the emission region, so excellent light conversion efficiency can be expected even with a small content.

[0048] The shell includes at least two elements of In, Ga, and S, and may include, for example, GaS, etc. In the present invention, the shell can suppress the trap emission of the core and maintain a narrow full width at half maximum of the emission wavelength, so it functions to improve color purity.

[0049] According to an exemplary embodiment, the quantum dots of the core-shell structure include, but are not limited to, AgInGaS / GaS, etc.

[0050] In some embodiments, the present invention may further include quantum dots of other structures in addition to the core-shell structure described above as needed. For example, it may further include quantum dots of core-shell structures such as InP / ZnSe / ZnS, InP / ZnS, InGaP / ZnS, InGaP / ZnSe / ZnS, etc., but is not limited thereto.

[0051] The quantum dots may be synthesized by a wet chemical process, a metal organic chemical vapor deposition (MOCVD) process, or a molecular beam epitaxy (MBE) process, but are not limited thereto. Preferably, synthesizing by a wet chemical process can obtain quantum dots with better optical properties.

[0052] The wet chemical process is a method of growing particles by putting a precursor substance into an organic solvent. When crystals grow, the organic solvent naturally coordinates on the surface of the quantum dot crystal to serve as a dispersant and regulate the growth of the crystal. Therefore, the growth of nanoparticles can be controlled through a process that is easier and cheaper than vapor deposition methods such as metal organic chemical vapor deposition and molecular beam epitaxy. Thus, it is preferable to manufacture the quantum dots using the wet chemical process.

[0053] In the present invention, the luminescent particles may be contained in an amount of 3 to 50% by weight, preferably 5 to 45% by weight, more preferably 8 to 40% by weight, based on 100% by weight of the solid components in the light conversion ink composition. When the luminescent particles are contained within the above range, the light conversion efficiency can be improved.

[0054] When the light-emitting particles are contained in an amount less than the above range, the light conversion efficiency may decrease, making it difficult to realize a high-quality display device. Further, when the amount exceeds the above range, the components for achieving curing may be insufficient, resulting in insufficient curing degree of the coating film, which may reduce the productivity in the subsequent processes of display manufacturing and the reliability of the product.

[0055] Polymerizable monomer In one embodiment of the present invention, the light conversion ink composition contains a polymerizable monomer.

[0056] The polymerizable monomer may contain a compound represented by the following Chemical Formula 2.

[0057]

Chemical Formula

[0058] In Chemical Formula 2, R4 is an alkylene group having 1 to 20 carbon atoms, a phenylene group, or a cycloalkylene group having 3 to 20 carbon atoms, 20 R5 and R6 are each independently hydrogen or a methyl group, and l may be an integer of 1 to 15. 10

[0059] As used herein, the alkylene group having 1 to 20 carbon atoms means a linear or branched divalent hydrocarbon composed of 1 to 20 carbon atoms, for example, methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, n-nonylene, etc., but is not limited thereto. 20

[0060] As used herein, the cycloalkylene group having 3 to 20 carbon atoms means a simple or fused cyclic divalent hydrocarbon composed of 3 to 10 carbon atoms, for example, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, etc., but is not limited thereto. 10 ​

[0061] The above C1 to C 20 alkylene group, phenylene group and C3 to C 10 cycloalkylene group, one or more hydrogens thereof may be replaced by a C1 to C6 alkyl group, a C2 to C6 alkenyl group, a C2 to C6 alkynyl group, a C3 to C 10 cycloalkyl group, a C3 to C 10 heterocycloalkyl group, a C3 to C 10 heterocycloalkyloxy group, a C1 to C6 haloalkyl group, a C1 to C6 alkoxy group, a C1 to C6 thioalkoxy group, an aryl group, an acyl group, hydroxy, thio, halogen, amino, alkoxycarbonyl, carboxy, carbamoyl, cyano, nitro and the like.

[0062] In one embodiment of the present invention, R 1 may be a C1 to C 20 alkylene group, and preferably may be a C2 to C 16 alkylene group. When R 1 is a C1 to C 20 alkylene group, the light-converting ink composition of the present invention has excellent dispersibility of the luminescent particles even without a solvent, improved jetting, and can improve the uniformity of the coating film hardness and thickness.

[0063] According to one example of the present invention, as described above, l may be an integer of 1 to 15, and preferably may be an integer of 1 to 5. When exceeding the above range, the viscosity is high, and the dispersibility may decrease.

[0064] Specific examples of the compound represented by the chemical formula 2 include, but are not limited to, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, 2-hydroxy-3-methacryloylpropyl acrylate, 1,9-bisacryloyloxynonane, and tripropylene glycol diacrylate.

[0065] The compound represented by the above chemical formula (2) enables the realization of a low-viscosity light-converting ink composition of 80 cP or less even without a solvent by improving the dispersibility of the light-emitting particles. Thereby, the light-converting ink composition according to the present invention can be effectively used for manufacturing a light-converting laminated substrate by an inkjet printing method.

[0066] In addition to the polymerizable monomer represented by the above chemical formula (2), the light-converting ink composition of the present invention may further contain a polymerizable compound commonly used in the art, within the limit not deviating from the object of the present invention. For example, monofunctional monomers, bifunctional monomers, and other polyfunctional monomers can be mentioned. Among these, bifunctional monomers are preferably used.

[0067] The type of the monofunctional monomer is not particularly limited, and examples include nonylphenyl carbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl carbitol acrylate, 2-hydroxyethyl acrylate, N-vinylpyrrolidone, and the like.

[0068] The type of the bifunctional monomer is not particularly limited, and examples include bis(acryloyloxyethyl) ether of bisphenol A and the like.

[0069] The type of the polyfunctional monomer is not particularly limited, and examples include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

[0070] At this time, when further containing a polyfunctional curable monomer having three or more functional groups and controlling the viscosity of the ink composition within 80 cP, inkjet characteristics can be obtained.

[0071] The polymerizable monomer may be contained in an amount of 30 to 95% by weight, preferably 40 to 90% by weight, based on 100% by weight of the total solid content of the photoconversion ink composition. When the polymerizable monomer is contained within the above range, there is an advantage that it is preferable in terms of the strength and smoothness of the pixel portion. When the polymerizable monomer is contained less than the above range, it becomes difficult to ensure the fluidity for inkjetting, and when it is contained exceeding the above range, it may induce a problem that the content of the light-emitting particles is insufficient and the light-emitting efficiency is lowered. Therefore, it is preferably contained within the above range.

[0072] Scattering particles The photoconversion ink composition according to the present invention may further contain scattering particles.

[0073] As the scattering particles, ordinary inorganic materials may be used, or preferably, metal oxides having an average particle size of 50 to 1000 nm may be included.

[0074] The metal oxide may be an oxide containing one kind of metal selected from the group consisting of Li, Be, B, Na, Mg, Al, Si, K, Ca, Sc, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Mo, Cs, Ba, La, Hf, W, Tl, Pb, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Ti, Sb, Sn, Zr, Nb, Ce, Ta, In, and combinations thereof, but is not limited thereto.

[0075] Specifically, one selected from the group consisting of Al2O3, SiO2, ZnO, ZrO2, BaTiO3, TiO2, Ta2O5, Ti3O5, ITO, IZO, ATO, ZnO-Al, Nb2O3, SnO, MgO, BaSO4, and combinations thereof can be used. If necessary, a material surface-treated with a compound having an unsaturated bond such as acrylate can also be used.

[0076] When the light conversion ink composition according to the present invention contains scattering particles, it is preferable because it can increase the path of the light emitted from the light-emitting particles through the scattering particles and enhance the overall light efficiency in the light conversion coating layer. In this regard, the light conversion ink composition of the present invention preferably contains one or more selected from TiO2, SiO2, ZnO, and BaSO4 as the scattering particles.

[0077] The scattering particles may have an average particle size of 50 to 1000 nm, and preferably, those in the range of 100 to 500 nm are used. At this time, if the particle size is too small, a sufficient scattering effect of the light emitted from the quantum dots cannot be expected. On the contrary, if it is too large, it will sink in the composition or the surface of the self-luminous layer with uniform quality cannot be obtained. Therefore, it is appropriately adjusted within the above range for use.

[0078] The scattering particles may be contained in an amount of 0.5 to 20% by weight, preferably 1 to 15% by weight, more preferably 2 to 10% by weight, based on 100% by weight of the total solid content of the light conversion ink composition. When the scattering particles are contained within the above range, it is preferable because the effect of increasing the emission intensity can be maximized. When the scattering particles are contained less than the above range, it is somewhat difficult to ensure the emission intensity to be obtained. When it exceeds the above range, there is a problem that the transmittance of the blue irradiation light is significantly reduced and the light conversion of the light-emitting particles does not work. Therefore, it is preferably used appropriately within the above range.

[0079] Photoinitiator The light conversion ink composition according to an embodiment of the present invention may further contain a photoinitiator.

[0080] In one embodiment of the present invention, the photoinitiator can be used without particularly limiting its type as long as it can polymerize the polymerizable monomer. For example, from the viewpoints of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc., the photoinitiator preferably uses one or more compounds selected from the group consisting of acetophenone-based compounds, benzophenone-based compounds, triazine-based compounds, non-imidazole-based compounds, oxime-based compounds, thioxanthone-based compounds, and phosphine oxide compounds.

[0081] For example, for curing a thick film of 5 μm or more, using an oxime-based compound or a phosphine oxide compound can ensure excellent physical properties in terms of the curing density and surface roughness of the cured film.

[0082] Specific examples of the oxime-based compound include o-ethoxycarbonyl-α-oxyimino-1-phenylpropan-1-one, etc. As commercially available products, Irgacure OXE 01 and OXE 02 from BASF are representative.

[0083] Specific examples of the phosphine oxide compound include Darocur TPO and Lucirin TPO from BASF, which are trimethylbenzoyl phenylphosphine oxide.

[0084] The photoinitiator may be contained in an amount of 0.1 to 10% by weight, preferably 0.5 to 8% by weight, based on 100% by weight of the total solid content of the photo-conversion ink composition. When the photoinitiator is contained within the above range, the photo-conversion ink composition becomes highly sensitive and the exposure time is shortened, so that productivity can be improved, which is preferable. When the photoinitiator is contained in less than the above range, curing by light is insufficient and sufficient hardness cannot be obtained. When it is contained in excess of the above range, the decrease in the photo-conversion efficiency of the light-emitting particles due to the photoinitiator rapidly increases, and there is a problem that the light-emitting intensity to be obtained cannot be obtained. Therefore, using it within the above range has the advantage that the intensity of the pixel portion and the smoothness at the surface of the pixel portion become good.

[0085] The photoinitiator may further contain a photoinitiation promoter in order to improve the sensitivity of the photo-conversion ink composition according to the present invention. When the photoinitiation promoter is included, there is an advantage that the sensitivity becomes even higher and the productivity is improved.

[0086] The photoinitiation promoter may preferably be one or more compounds selected from the group consisting of, for example, amine compounds, carboxylic acid compounds, and organic sulfur compounds having a thiol group, but is not limited thereto.

[0087] The photoinitiation promoter can be appropriately added and used within a range that does not impair the effects of the present invention.

[0088] Additive The photo-conversion ink composition according to an embodiment of the present invention may further contain additives such as a surfactant and an adhesion promoter in addition to the above-described components in order to enhance the flatness or adhesion of the coating film.

[0089] When the photo-conversion ink composition according to the present invention contains the surfactant, there is an advantage that the flatness of the coating film can be improved. For example, the surfactant may be a fluorine-based surfactant such as BM-1000, BM-1100 (BM Chemie), Prolide FC-135 / FC-170C / FC-430 (Sumitomo 3M Limited), SH-28PA / -190 / -8400 / SZ-6032 (Toray Silicone Co., Ltd.), but is not limited thereto.

[0090] The adhesion promoter can be added to enhance the adhesion to the substrate and may include a silane coupling agent having a reactive substituent selected from the group consisting of a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, and combinations thereof, but is not limited thereto.

[0091] In addition, the light-converting ink composition according to the present invention may further contain additives such as antioxidants, ultraviolet absorbers, and anti-aggregation agents, as long as the effects of the present invention are not inhibited. Also, those additives can be appropriately added and used by those skilled in the art as long as the effects of the present invention are not inhibited.

[0092] The additives may be used in an amount of 0.01 to 10% by weight, specifically 0.02 to 8% by weight, more specifically 0.03 to 5% by weight, based on 100% by weight of the total solid content of the light-converting ink composition, but are not limited thereto.

[0093] When the additives are contained within the above range, it is preferable because it can improve the flatness, adhesion, etc. of the light-converting ink composition. When the additives are contained less than the above range, the expected effects such as flatness or adhesion may not be sufficient. When the additives are contained exceeding the above range, there are problems such as a decrease in the content of luminescent particles or polymerizable monomers, a decrease in luminescence intensity, or a decrease in the degree of curing of the cured film. Therefore, using within the above range has the advantage that the strength of the pixel portion and the flatness or adhesion on the surface of the pixel portion become good.

[0094] Solvent The light-converting ink composition according to an embodiment of the present invention may further contain a solvent or may be a solvent-free type that does not contain a solvent. When the light-converting ink composition of the present invention contains a solvent, for example, it may further contain a solvent in an amount of 20% by mass or less based on 100% by weight of the entire light-converting ink composition.

[0095] Preferably, the light-converting ink composition according to an embodiment of the present invention may be a solvent-free type that does not contain a solvent in terms of continuous processability.

[0096] Even in the case of the solvent-free type of the light-converting composition of the present invention that does not contain a solvent, by containing the above-described polymerizable monomer, it is excellent in the optical properties and dispersibility of luminescent particles, can achieve a low viscosity, and is excellent in the nozzle jetting characteristics of the ink.

[0097] As the solvent, an ether or ester solvent, an aliphatic saturated hydrocarbon solvent, a halogenated hydrocarbon solvent, an aromatic hydrocarbon solvent, etc. may be used. For example, propylene glycol methyl ether acetate (PGMEA), ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoalkyl ethers such as ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dialkyl ethers such as diethylene glycol dibutyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, alkylene glycol alkyl ether acetates such as 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, and cyclohexanone, alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerin, esters such as ethyl 3-ethoxypropionate and methyl 3-methoxypropionate, cyclic esters such as γ-butyrolactone, etc. may be used.

[0098] <Light conversion laminated substrate, backlight unit, and image display device> One embodiment of the present invention is a light conversion laminated substrate that absorbs the light emitted by a light-emitting element and converts and emits it into blue, green, or red. The light conversion laminated substrate is formed using the above-described light conversion ink composition.

[0099] Further, the present invention can provide a light conversion pixel substrate having color filter functions of red (RED), green (GREEN), and blue (BLUE), which is manufactured using the above-described light conversion ink composition.

[0100] The above-mentioned light conversion laminated substrate and / or light conversion pixel substrate can be formed by applying the above-mentioned light conversion ink composition to a predetermined area by an inkjet method and curing the applied light conversion ink composition.

[0101] Examples of the substrate include flat substrates such as glass substrates, silicon substrates, polycarbonate substrates, polyester substrates, aromatic polyamide substrates, polyamideimide substrates, polyimide substrates, Al substrates, and GaAs substrates, but are not limited thereto. These substrates can be subjected to pretreatment such as chemical treatment with chemicals such as silane coupling agents, plasma treatment, ion plating treatment, sputtering treatment, gas phase reaction treatment, and vacuum evaporation treatment. When a silicon substrate or the like is used as the substrate, a charge-coupled device (CCD), a thin-film transistor (TFT), or the like may be formed on the surface of the silicon substrate or the like. Also, a partition matrix may be formed. The curing may be performed under thermosetting conditions.

[0102] For example, the curing may be performed at 100 to 250 °C, preferably 150 to 230 °C, for 5 to 30 minutes, preferably 10 minutes.

[0103] Injected from a piezo inkjet head, which is an example of an inkjet injector, in order to form an appropriate phase on the substrate, it is necessary to balance the characteristics such as viscosity, fluidity, and quantum dot particles well in the inkjet head. The piezo inkjet head used in the present invention is not limited, but injects ink having a droplet size of about 3 to 100 pL, preferably about 5 to 40 pL.

[0104] The viscosity of the light conversion ink composition of the present invention is suitably about 3 to 50 cP, and more preferably adjusted in the range of 7 to 40 cP.

[0105] When the light conversion laminated substrate according to the present invention is applied to a blue light source, excellent light output can be obtained.

[0106] One embodiment of the present invention is a green light-emitting element that emits green light. Specifically, it may emit green light with a wavelength of 500 to 600 nm, but is not limited thereto.

[0107] The green light-emitting element may be a green light-emitting diode (LED). One embodiment of the present invention relates to a backlight unit characterized by including a light conversion laminated substrate applied to the blue light source.

[0108] The backlight unit may further include components usually included such as a light guide plate and a reflector.

[0109] One embodiment of the present invention relates to an image display device including the backlight unit.

[0110] The image display device of the present invention includes various image display devices such as not only a normal liquid crystal display device but also an electroluminescent display device, a plasma display device, and a field emission display device.

[0111] Also, one embodiment of the present invention relates to a light conversion pixel including a cured product of the aforementioned light conversion ink composition.

[0112] For example, it includes the steps of applying the aforementioned light conversion ink composition to a predetermined area by an inkjet method and curing the applied light conversion ink composition, and a light conversion pixel can be manufactured by forming a pattern of the light conversion ink composition.

Example

[0113] Hereinafter, for the understanding of the present invention, experimental examples including specific examples and comparative examples are presented. However, these are merely illustrative of the present invention and do not limit the scope of the appended claims. It is obvious to those skilled in the art that various changes and modifications to the examples are possible within the scope of the present invention and the scope of the technical idea. It is natural that such variations and modifications belong to the scope of the appended claims. In addition, unless otherwise specified, “%” and “parts” indicating content hereinafter are based on weight.

[0114] Synthesis example Synthesis Example 1: Synthesis of AgInGaS / GaS Core-Shell Luminescent Particles (A-2) 0.0625 mmol of silver iodide (AgI, 99.999%), 1.25 mmol of gallium acetylacetonate (Ga(acac)3, 99.99%) and 1 mmol of sulfur (99.998%) were placed in a three-neck flask together with 1.5 mL of 1-dodecanethiol (DDT ≥ 98%) and 5 mL of oleylamine (OLA, 70%) to prepare a mixed solution. The mixed solution was heated at 120 °C to degas, then purged with N2, and the temperature was raised to 240 °C, which is the growth temperature. It was held at this temperature for 30 minutes to grow AGS core QDs. 0.01 mmol of indium acetate (In(Ac)3, 99.99%) was added to this AGS core solution. The mixed solution was heated at 120 °C to degas, then purged with N2, and the temperature was raised to 240 °C, which is the growth temperature. It was held at this temperature for 10 minutes to grow AIGS core QDs.

[0115] 30 nmol of AIGS core QDs were mixed with 7 ml of oleylamine, 0.1 mmol of gallium acetylacetonate (Ga(acac)3, 99.99%), and 0.1 mmol of 1,3 - dimethyl - thiourea, and the temperature was rapidly raised to 230 °C. Then, it was increased by 2 °C per minute under inert conditions until it reached 280 °C. The solution was cooled back to room temperature, and sulfur compounds that did not participate in the reaction for 30 minutes were removed by degassing. The quantum dots were precipitated in ethanol, purified by centrifugation, and then dried under reduced pressure to obtain AgInGaS / GaS quantum dot powder.

[0116] The obtained quantum dot powder was diluted to 0.1 w% in a chloroform solution, and then the emission wavelength and full - width at half - maximum were measured using QE - 2100 (Otsuka Electronics). As a result of measuring the emission wavelength and full - width at half - maximum, they were 523 nm and 33 nm, respectively.

[0117] Synthesis Example 2: Synthesis of AgInGaS / ZnS Core - Shell Emitting Particles (A - 3) 0.0625 mmol of silver iodide (AgI, 99.999%), 1.25 mmol of gallium acetylacetonate (Ga(acac)3, 99.99%), and 1 mmol of sulfur (99.998%) were placed in a three - neck flask together with 1.5 mL of 1 - dodecanethiol (DDT≥98%) and 5 mL of oleylamine (OLA, 70%) to prepare a mixed solution. The mixed solution was heated at 120 °C for degassing, then purged with N2, and the temperature was raised to 240 °C, which is the growth temperature. It was held at this temperature for 30 minutes to grow AGS core QDs. 0.01 mmol of indium acetate (In(Ac)3, 99.99%) was added to this AGS core solution. The mixed solution was heated at 120 °C for degassing, then purged with N2, and the temperature was raised to 240 °C, which is the growth temperature. It was held at this temperature for 30 minutes to grow AIGS core QDs.

[0118] 8 mmol of zinc acetate, 8 mL of oleic acid, and 4 mL of 1-octadecene were placed in a three-necked flask. While stirring, after undergoing a degassing process at 110 °C and 100 mTorr for 30 minutes, the solution was heated at 270 °C under an inert gas until it became transparent, and then cooled to 60 °C to obtain a transparent zinc oleate-form zinc precursor solution.

[0119] 8 mmol of sulfur (S) and 10 mL of tri-n-octylphosphine (TOP) were placed in a three-necked flask. While stirring in an inert gas atmosphere until the solution became transparent, the solution was heated at 80 °C and then cooled to room temperature to obtain a TOP:S-form sulfur precursor solution.

[0120] In another three-necked flask, a nanoparticle solution of AIGS was placed. After adjusting the temperature of the flask to 240 °C, 0.6 mL of the pre-prepared zinc precursor solution was quickly injected using a syringe. Thereafter, 0.3 mL of the pre-prepared sulfur precursor solution was injected into the flask at a rate of 2 mL / hr using a syringe pump. After the injection was completed, the reaction was allowed to proceed for another 1 hour and then quickly cooled to terminate the reaction. The quantum dots were precipitated in ethanol, purified by centrifugation, and then dried under reduced pressure to obtain AgInGaS / ZnS quantum dot powder. The emission wavelength and full width at half maximum of the obtained quantum dot powder were measured through the same method as in Synthesis Example 1, and as a result, it was confirmed that they were 523 nm and 42 nm, respectively.

[0121] Synthesis Example 3: Synthesis of AgInGaS / ZnSe / ZnS Core-Shell Luminescent Particles (A-4) 0.0625 mmol of AgI (99.999%), 1.25 mmol of gallium acetylacetonate (Ga(acac)3, 99.99%) and 1 mmol of sulfur (99.998%) were placed in a three-neck flask together with 1.5 mL of 1-dodecanethiol (DDT≥98%) and 5 mL of oleylamine (OLA, 70%) to produce a mixed solution. After heating the mixed solution at 120 °C to degas it, N2 purging was carried out and the temperature was raised to 240 °C, which is the growth temperature. It was held at this temperature for 30 minutes to grow the AGS core QDs. 0.01 mmol of indium acetate (In(Ac)3, 99.99%) was added to this AGS core solution. After heating the mixed solution at 120 °C to degas it, N2 purging was carried out and the temperature was raised to 240 °C, which is the growth temperature. It was held at this temperature for 30 minutes to grow the AIGS core QDs.

[0122] Subsequently, 8 mmol of zinc acetate, 16 mmol of oleic acid and 20 mL of trioctylamine were placed in a reactor and heated at 120 °C under vacuum. After 1 hour, the atmosphere in the reactor was replaced with nitrogen and the reactor was heated to 280 °C. 2 mL of the previously synthesized core solution was added, and subsequently, 16 mmol of selenium in trioctylphosphine (Se / TOP) was added. Then the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution quickly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and then dried under reduced pressure to form the AgInGaS / ZnSe core-shell.

[0123] Subsequently, 8 mmol of zinc acetate, 16 mmol of oleic acid and 20 mL of trioctylamine were placed in a reactor and heated at 120 °C under vacuum. After 1 hour, the atmosphere in the reactor was replaced with nitrogen and the reactor was heated to 280 °C. 2 mL of the previously synthesized core solution was added, and subsequently, 16 mmol of sulfur in trioctylphosphine (S / TOP) was added. Then the final mixture was reacted for 2 hours. The quantum dots were precipitated in ethanol, purified by centrifugation, and then the AgInGaS / ZnSe / ZnS quantum dot powder was obtained. As a result of measuring the emission wavelength and full width at half maximum of the obtained quantum dots, they were 525 nm and 45 nm, respectively.

[0124] Synthesis Example 4: Synthesis of InP / ZnS Core-Shell Luminescent Particles (A-5) 0.05839 g of indium acetate, 0.12019 g of oleic acid, and 10 mL of 1-octadecene (ODE) were placed in a three-neck flask. While stirring the flask, after undergoing a degassing process at 110 °C and 100 mTorr for 30 minutes, the solution was heated at a temperature of 270 °C under an inert gas until it became transparent.

[0125] As a phosphorus (P) precursor, 0.025054 g of tris(trimethylsilyl)phosphine was prepared, placed in 0.5 mL of 1-octadecene and 0.5 mL of tri-n-octylphosphine, stirred, and this was rapidly injected into the flask heated at 270 °C under an inert gas. After reacting for 1 hour, it was rapidly cooled to terminate the reaction. Thereafter, when the temperature of the flask reached 100 °C, 10 mL of toluene was injected and then transferred into a 50 mL centrifuge tube. After adding 10 mL of ethanol, it was purified twice using a precipitation and redispersion method. After dispersing the purified InP core nanoparticles in 1-octadecene, they were stored.

[0126] 3.669 g of zinc acetate, 20 mL of oleic acid, and 20 mL of 1-octadecene were placed in a three-neck flask. While stirring, after undergoing a degassing process at 110 °C and 100 mTorr for 30 minutes, the solution was heated at a temperature of 270 °C under an inert gas until it became transparent and then cooled to 60 °C to obtain a transparent zinc oleate-form zinc precursor solution.

[0127] 0.6412 g of sulfur (S) and 10 mL of tri-n-octylphosphine (TOP) were placed in a three-neck flask. While stirring under an inert gas atmosphere, the solution was heated at a temperature of 80 °C until it became transparent and then cooled to room temperature to obtain a TOP:S-form sulfur precursor solution.

[0128] Another three-necked flask was charged with a pre-prepared nanoparticle solution of InP cores. After adjusting the temperature of the flask to 300 °C, 0.6 mL of a pre-prepared zinc precursor solution was rapidly injected using a syringe. Subsequently, 0.3 mL of a pre-prepared sulfur precursor solution was injected into the flask at a rate of 2 mL / hr using a syringe pump. After the injection was completed, the reaction was allowed to proceed for an additional 3 hours and then rapidly cooled to terminate the reaction. When the temperature of the flask reached 100 °C, 10 mL of toluene was injected and then transferred to a 50 mL centrifuge tube. After adding 10 mL of ethanol, it was purified twice using a precipitation and redispersion method and then dried under reduced pressure to obtain InP / ZnS quantum dot powder. The emission wavelength and full width at half maximum of the obtained quantum dots were 524 nm and 43 nm, respectively.

[0129] Synthesis Example 5: Synthesis of InP / ZnSe / ZnS Core-Shell Luminescent Particles (A-6) 0.4 mmol (0.058 g) of indium acetate, 0.6 mmol (0.15 g) of palmitic acid, and 20 mL of 1-octadecene were placed in a reactor and heated at 120 °C under vacuum. After 1 hour, the atmosphere in the reactor was replaced with nitrogen. After heating to 280 °C, a mixed solution of 0.2 mmol (58 μl) of tris(trimethylsilyl)phosphine (TMS3P) and 1.0 mL of trioctylphosphine was rapidly injected and reacted for 0.5 minute.

[0130] Subsequently, 2.4 mmol (0.448 g) of zinc acetate, 4.8 mmol of oleic acid, and 20 mL of trioctylamine were placed in the reactor and heated at 120 °C under vacuum. After 1 hour, the atmosphere in the reactor was replaced with nitrogen and the reactor was heated to 280 °C. 2 mL of the previously synthesized InP core solution was added, and subsequently, 4.8 mmol of selenium in trioctylphosphine (Se / TOP) was added, and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution rapidly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and then dried under reduced pressure to form an InP / ZnSe core-shell.

[0131] Subsequently, 2.4 mmol (0.448 g) of zinc acetate, 4.8 mmol of oleic acid, and 20 mL of trioctylamine were placed in a reactor and heated at 120 °C under vacuum. After 1 hour, the atmosphere in the reactor was replaced with nitrogen and the reactor was heated to 280 °C. 2 mL of the previously synthesized InP core solution was added, followed by 4.8 mmol of sulfur in trioctylphosphine (S / TOP). The final mixture was then reacted for 2 hours. Ethanol was added to the reaction solution rapidly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and then dried under reduced pressure to obtain quantum dots with an InP / ZnSe / ZnS core-shell structure. The emission wavelength and full width at half maximum of the obtained quantum dots were 523 nm and 43 nm, respectively.

[0132] Synthesis Example 6: Synthesis of Compound L1 129.2 g of 4-tert-Butoxycarbonylamino-piperidin-1-yl)-acetic acid (Apexmol Technology), 73.8 mole of diethylene glycol monoethyl ether, 1.6 g of p-toluenesulfonic acid, and 200 g of toluene were placed in a 1000 mL four-necked flask equipped with a Dean stark, a reflux condenser, and a thermometer, and reacted for 8 hours while heating and stirring at 110 °C. After confirming the amount of water removed, the reaction was terminated. The reaction product was worked up with a 10% aqueous solution of sodium hydrogen carbonate, then separated, the organic liquid layer was dried over magnesium sulfate, and then concentrated under reduced pressure.

[0133] Subsequently, 100 g of dichloromethane and 3.0 g of trifluoroacetic acid were added to the concentrate and reacted at room temperature for 2 hours.

[0134] After completion of the reaction, the reaction product was worked up with a 10% aqueous solution of sodium hydrogen carbonate, then separated, the organic liquid layer was dried over magnesium sulfate, concentrated under reduced pressure, and then column purified to obtain the following Compound L1. Yield: 80 g, GC-MS: 275.

[0135] 1HNMR (400 MHz, CDCl3): δ 4.27 (t, 2H), 3.43 - 3.67 (m, 8H), 3.35 (d, 2H), 2.65 (s, 1H), 1.75 - 2.25 (m, 10H), 1.13 (t, 3H) L1: TIFF0007717527000017.tif15114

[0136] Synthesis Example 7: Synthesis of Compound L2 Into a 1000 mL four-necked flask equipped with a Dean-Stark apparatus, a reflux condenser, and a thermometer, 87.6 g of 2-(4-sulfanylpiperidin-1-yl)acetic acid, 73.8 g of diethylene glycol monoethyl ether, 1.2 g of p-toluenesulfonic acid, and 200 g of toluene were added, and the mixture was reacted for 6 hours while heating and stirring at 110 °C. After confirming the amount of water removed, the reaction was terminated. The reaction product was put into a 10% aqueous solution of sodium hydrogen carbonate and stirred, then separated, and the organic liquid layer was dried over magnesium sulfate, filtered, and concentrated under reduced pressure.

[0137] Subsequently, column purification was carried out to obtain the following compound L2. Yield: 75 g, GC-MS: 292 1 HNMR (400 MHz, CDCl3): δ 4.25 (t, 2H), 3.40 - 3.66 (m, 8H), 3.33 (d, 2H), 2.58 (s, 1H), 1.65 - 2.26 (m, 8H), 1.11 (t, 3H) L2: TIFF0007717527000018.tif15114

[0138] Synthesis Example 8: Synthesis of Compound L3 Into a 1000 mL four-necked flask equipped with a Dean-Stark apparatus, a reflux condenser, and a thermometer, 136.2 g of [4-(tert-Butoxycarbonylamino-methyl)-piperidin-1-yl]-acetic acid, 82.1 g of Diethyleneglycolmonoallyl ether (Aldrich), 3.0 g of p-toluenesulfonic acid, and 200 g of toluene were added, and the reaction was carried out for 6 hours with heating and stirring at 110 °C. After confirming the amount of water removed, the reaction was terminated. The reaction product was put into a 10% aqueous solution of sodium hydrogen carbonate and stirred, then separated, and the organic liquid layer was dried over magnesium sulfate and filtered, and then concentrated under reduced pressure.

[0139] Subsequently, 100 g of dichloromethane and 3.0 g of trifluoroacetic acid were added to the concentrate, and the reaction was carried out at room temperature for 2 hours.

[0140] After completion of the reaction, it was worked up with a 10% aqueous solution of sodium hydrogen carbonate, then separated, and the organic liquid layer was dried over magnesium sulfate and concentrated under reduced pressure, and then column purification was carried out to obtain the following compound L3. Yield: 96 g, GC-MS: 301 1 HNMR (400 MHz, CDCl3): δ 5.92 (m, 1H), 4.29 (t, 2H), 4.03 (t, 2H), 3.55 - 3.66 (m, 6H), 3.31 (d, 2H), 2.60 (d, 2H), 1.40 - 2.60 (m, 11H) L3: TIFF0007717527000019.tif13114

[0141] Synthesis Example 9: Synthesis of Compound L4 A Dean Stark, reflux condenser, and a 1000 mL four-necked flask equipped with a thermometer were charged with 129.2 g of 4-tert-Butoxycarbonylamino-piperidin-1-yl)-acetic acid (Apex Technology), 153.1 g of 2-(2-(2-(2-(2-allyloxyethoxy)ethoxy)ethoxy)ethoxy)ethan-1-ol, 3.6 g of p-toluenesulfonic acid, and 200 g of toluene. The mixture was reacted for 8 hours with heating and stirring at 110 °C. After confirming the amount of water removed, the reaction was terminated. The reaction product was worked up with a 10% aqueous solution of sodium hydrogen carbonate, then separated, and the organic liquid layer was dried over magnesium sulfate and concentrated under reduced pressure.

[0142] Subsequently, 100 g of dichloromethane and 3.0 g of trifluoroacetic acid were added to the concentrate, and the reaction was carried out at room temperature for 2 hours.

[0143] After completion of the reaction, the reaction mixture was worked up with a 10% aqueous solution of sodium hydrogen carbonate, then separated, and the organic liquid layer was dried over magnesium sulfate and concentrated under reduced pressure. Then, column purification was performed to obtain the following compound L4. Yield: 110 g, GC-MS: 419 1 HNMR (400 MHz, CDCl3): δ 5.87 (m, 1H), 5.13 - 5.27 (d, 2H), 4.23 (t, 2H), 4.00 (t, 2H), 3.55 - 3.69 (m, 18H), 3.32 (d, 2H), 2.61 (d, 1H), 1.70 - 2.26 (m, 10H) L4: TIFF0007717527000020.tif21114

[0144] Synthesis Example 10: Quantum Dots (A-7) by Ligand Substitution Reaction 3.00 g of the AIGS quantum dots of the synthesis example of A-2 was charged with "Compound L1", and the reaction was carried out for 1 hour while heating at 60 °C under a nitrogen atmosphere.

[0145] Subsequently, 25 mL of n-hexane was added to the reactants to precipitate the quantum dots, followed by centrifugation to separate the precipitate. Then, HDDA was added and dispersed while heating at 80 °C. The solid content was adjusted to 50% with HDDA. The maximum emission wavelength was 522 nm.

[0146] Synthesis Example 11: Quantum Dots (A-8) by Ligand Substitution Reaction The same procedure as in Synthesis Example 10 was carried out, except that 3.00 g of the AIGS quantum dots from the synthesis example of A-2 was used with "Compound L2".

[0147] The solid content was adjusted to 50% with HDDA. The maximum emission wavelength was 523 nm. Synthesis Example 12: Quantum Dots (A-9) by Ligand Substitution Reaction The same procedure as in Synthesis Example 10 was carried out, except that 3.00 g of the AIGS quantum dots from the synthesis example of A-2 was used with "Compound L3".

[0148] The solid content was adjusted to 50% with HDDA. The maximum emission wavelength was 524 nm. Synthesis Example 13: Quantum Dots (A-10) by Ligand Substitution Reaction The same procedure as in Synthesis Example 10 was carried out, except that 3.00 g of the quantum dots from the synthesis example of A-2 was used with "Compound L4".

[0149] The solid content was adjusted to 50% with HDDA. The maximum emission wavelength was 526 nm. Synthesis Example 14: Comparative Synthesis Example (A-11) 3.00 g of the quantum dots from the synthesis example of A-5 was added with "Compound L1", and the reaction was carried out for one hour while heating at 60 °C under a nitrogen atmosphere.

[0150] Subsequently, 25 mL of n-hexane was added to the reactants to precipitate the quantum dots, followed by centrifugation to separate the precipitate. Then, HDDA was added and dispersed while heating at 80 °C. The solid content was adjusted to 50% with HDDA. The maximum emission wavelength was 525 nm.

[0151] Examples and Comparative Examples: Production of Photo-conversion Ink Composition The respective components were mixed with the compositions shown in Tables 1 to 2 below to produce a light-converting ink composition (unit: wt%).

[0152]

Table 1

[0153]

Table 2

[0154] Experimental example 1. Production of the light-converting coating layer and measurement of the light-converting efficiency Each of the light-converting ink compositions produced in the examples and comparative examples was applied onto a 5 cm × 5 cm glass substrate by an inkjet method. After that, as an ultraviolet light source, a 1 kW high-pressure mercury lamp containing all of g, h, and i lines was used to irradiate at 1000 mJ / cm 2 Then, it was heated in a heating oven at 180°C for 30 minutes to produce a light-converting coating layer.

[0155] After the produced light-converting coating layer was positioned above a blue light source (XLamp XR-E LED, Royal blue450, Cree), using a luminance meter (CAS140CT Spectrometer, Instrument systems), (A) the light-converting efficiency was measured using the following formula. The measured results are shown in Table 3.

[0156]

Equation

[0157] Also, regarding the result of the measured (A) light-converting efficiency, taking the light-converting efficiency (%) of the InP / ZnS core-shell luminescent particles of Comparative Example 3 as 100%, the improved (B) light-converting efficiency (%) is shown in Table 3.

[0158] 2. Full width at half maximum (FWHM) of the emission spectrum After positioning the manufactured light conversion coating layer above a blue light source (XLamp XR-E LED, Royal blue 450, Cree Inc.), the full-width at half-maximum value of the emission spectrum measured using a luminance meter (CAS140CT Spectrometer, Instrument systems GmbH) was obtained.

[0159] The measured full-width at half-maximum values are shown in Table 3. The lower the full-width at half-maximum value, the better the color purity. In particular, when the full-width at half-maximum is 40 nm or less, better color purity can be expected.

[0160] 3. Uniformity of the coating film As shown in Figure 2, 20 droplets of 20 pL were dropped onto a substrate with a well-shaped pattern of 30 μm in width, 90 μm in length, and 10 μm in depth using an inkjet device from UniJet. After 1 hour, jetting was performed on adjacent pixels in the same manner. The jetted substrate was irradiated with ultraviolet light and then heated in a heating oven for 30 minutes in the same manner as the method described in the production of the light conversion coating layer and the measurement of the light conversion efficiency. After that, the film thickness of the two patterns was measured using a film thickness meter (Dektak, manufactured by Bruker Corporation), and the film thickness change rate between the two patterns was obtained and described in Table 3.

[0161] Film thickness change rate of 0% to 5% or less: ○ Film thickness change rate exceeding 5% to 10% or less: △ Film thickness change rate exceeding 10%: ×

[0162]

Table 3

[0163] From the results of the above experiments, when using the core and shell of the present invention, relatively high light conversion efficiency is achieved, and it can be confirmed that it also has excellent effects in terms of jetting property, flatness, and light resistance. Specifically, referring to FIG. 1 for explanation, it can be confirmed that the examples of the present invention have a larger light conversion spectrum area and (A) higher light conversion efficiency (%) than the comparative examples. In particular, when based on (A) the light conversion efficiency, it can be seen that all examples of the present invention have a light conversion efficiency of 20% or more, which is suitable for the formation of pixels.

[0164] Also, as in Examples 1 to 6, when the compound represented by Formula (2) is used as the polymerizable monomer, it was confirmed that a more improved uniformity of the coating film occurred.

[0165] In comparison, it was confirmed that some of the comparative examples did not even remotely reach a light conversion efficiency of 20%, and thus, it was found that the emission intensity was weak and it was impossible to use them as pixels.

[0166] Moreover, the examples of the present invention have a full width at half maximum of 40 nm or less, not only showing excellent color purity but also excellent properties in terms of the uniformity of the coating film. In contrast, the comparative examples showed a decreased result compared to the examples. In particular, as in Examples 1 to 6, when the compound represented by Formula (2) is included as the polymerizable monomer, it was confirmed that relatively more excellent uniformity of the coating film occurred.

Claims

1. Comprising luminescent particles and a polymerizable monomer, wherein the luminescent particles comprise a core containing Ag, In, Ga, and S, and a shell containing at least two elements of In, Ga, and S, having a ligand layer on the surface, and the ligand layer contains a compound represented by the following Chemical Formula 1, characterized in that it is a light-converting ink composition. 【Chemical 1】 (In the above Chemical Formula 1, A is -NH₂ or -SH, R₁ and R₂ are, independently of each other, directly linked or an alkylene group having 1 to 12 carbon atoms, R₃ is an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, or an aryl group having 4 to 10 carbon atoms, L₁ is 【Chem.】 and m and n are each independently an integer from 0 to 10, but not 0 at the same time.)

2. The light-converting ink composition according to Claim 1, wherein the compound represented by Chemical Formula 1 is represented by any one of the following Chemical Formulas 1-1 to 1-13. 【Chemical Formula 1-1】 【Chemical Formula 1-2】 【Chemical Formula 1-3】 【Chemical Formula 1-4】 【Chemical Formula 1-5】 [Chemical Formula 1-6] 【Chemical Formula 1-7】 【Chemical Formula 1-8】 【Chemical Formula 1-9】 【Chemical Formula 1-10】 【Chemical 1-11】 【Chemical Formula 1-12】 【Chemical Formula 1-13】 。

3. The light-converting ink composition according to Claim 1, wherein the shell contains GaS.

4. The light-converting ink composition according to Claim 1, wherein the polymerizable monomer contains a compound represented by the following Chemical Formula 2: [Chemical Formula 2] In the above Chemical Formula 2, R ４ is an alkylene group, phenylene group or cycloalkylene group of C １ to C ２０ and is a cycloalkylene group of C ３ to C １０ and R ５ and R ６ are each independently hydrogen or a methyl group, l is an integer from 1 to 15.

5. The light-converting ink composition according to Claim 4, wherein the polymerizable monomer further contains a monofunctional or polyfunctional monomer having three or more unsaturated double bonds.

6. The light-converting ink composition according to Claim 4, wherein the compound represented by Chemical Formula 1 contains one or more selected from 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, 2-hydroxy-3-methacryloxypropyl acrylate, 1,9-bisacryloyloxynonane, and tripropylene glycol diacrylate.

7. The light-converting ink composition according to Claim 1, further comprising one or more selected from scattering particles, a photoinitiator, an additive, and a solvent.

8. The scattering particles are Al ２ O ３ , SiO ２ , ZnO, ZrO ２ , BaTiO ３ , TiO ２ , Ta ２ O ５ , Ti ３ O ５ , ITO, IZO, ATO, ZnO-Al, Nb ２ O ３ , SnO, MgO, and at least one selected from the group consisting of combinations thereof, the optical conversion ink composition according to claim 7.

9. The light-converting ink composition according to Claim 1, which is a solvent-free type without containing a solvent.

10. A light-converting laminated substrate manufactured using the light-converting ink composition according to any one of Claims 1 to 9.

11. A backlight unit comprising the light-converting laminated substrate according to Claim 10.

12. A light-converting pixel substrate manufactured using the light-converting ink composition according to any one of Claims 1 to 9.

13. An image display device including the backlight unit according to claim 11, or the light conversion pixel substrate according to claim 12.

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