JP7485630B2 - Light conversion ink composition, color filter, and image display device - Google Patents

Description

The present invention relates to a light conversion ink composition, a color filter, and an image display device, and more specifically to a light conversion ink composition that is capable of forming a thick film having excellent dispersibility of quantum dots and excellent optical properties of quantum dots even without substantially containing a solvent, and has improved adhesion of the coating film, a color filter formed using the same, and an image display device equipped with the color filter.

A color filter is a thin-film optical component that extracts three colors, red, green, and blue, from white light and functions at minute pixel levels.

In this regard, a method for manufacturing a color filter using a spontaneous light-emitting photosensitive resin composition containing quantum dots has been proposed in recent years to provide not only excellent pattern characteristics but also high color reproduction rate.

A commonly known photolithography method using a self-luminous photosensitive resin composition containing quantum dots is a method for forming color filters by coating, exposure, development, and curing. Although this type of photolithography method is excellent in terms of the sophistication and reproducibility of color filters, it has the disadvantage that the manufacturing process, labor, and cost are increased because coating, exposure, development, and curing processes are required for each color to form a pixel, and the number of control factors between processes increases, making it difficult to manage the yield.

For this reason, instead of the photolithography method, an inkjet method has been proposed that can color multiple colors, including red, green, and blue, at once.

In recent years, with the demand for high color reproduction (color density relative to NTSC) in monitors, TVs, etc., it has become necessary to improve the luminance of quantum dots. One method for improving luminance is to increase the film thickness. However, there is a limit to how thick the film can be made with the ink composition containing quantum dots and a solvent disclosed in Korean Patent Registration No. 10-1475520.

From this perspective, there is a demand for a solvent-free or low-solvent ink composition containing quantum dots that is substantially free of solvent. However, when quantum dots are produced in a solvent-free or low-solvent ink composition, uniform dispersion is difficult, and the quantum dots may aggregate, degrading the optical properties of the quantum dots, or the viscosity may increase, resulting in poor jetting properties. In particular, when the content of quantum dots in the ink composition is increased to increase the film thickness, there is a problem that the quantum dots further aggregate, causing a serious deterioration in the optical properties of the quantum dots and a decrease in the adhesion of the coating film.

Therefore, there is a need to develop an ink composition that has excellent dispersibility of quantum dots even when no solvent is used or when only a small amount of solvent is used, can form a thick film with excellent optical properties of quantum dots, and has improved adhesion of the coating film.

One object of the present invention is to provide a light conversion ink composition that can form a thick film having excellent quantum dot dispersibility and excellent optical properties of the quantum dots even without substantially containing a solvent, and that has improved adhesion of the coating film.

Another object of the present invention is to provide a light conversion pixel containing a cured product of the light conversion ink composition.

Another object of the present invention is to provide a color filter including the light conversion pixel.

A further object of the present invention is to provide an image display device equipped with the above-mentioned color filter.

On the other hand, the present invention includes a quantum dot, a curable monomer, and a surfactant,
The quantum dot has a ligand layer on its surface, the ligand layer including one or more of the compounds represented by the following chemical formulas 1a to 1e:
A light conversion ink composition is provided, wherein the surfactant comprises a reactive silicone surfactant.

In the above formula,
R' and R'' are each independently a hydrogen atom; a carboxyl group; a phenyl group; or a _C1 - _C20 alkyl group unsubstituted or substituted with a thiol group;
R′ and R″ are not simultaneously a hydrogen atom; a phenyl group; or an unsubstituted C ₁ -C ₂₀ alkyl group;
R ^a , R ^b , and R ^c are each independently a C ₁ to C ₂₂ alkyl group or a C ₄ to C ₂₂ alkenyl group;
R ^d is a C ₁ -C ₂₂ alkylene group, a C ₃ -C ₈ cycloalkylene group, or a C ₆ -C ₁₄ arylene group;
A and B are each independently absent, a C ₁ -C ₂₂ alkylene group, O, NR, or S;
R is hydrogen or a _C1 - _C22 alkyl group;
X is a carboxyl group, a phosphate group, a thiol group, an amine group, a tetrazole group, an imidazole group, a pyridine group, or a lipoamide group;
n is an integer from 1 to 20,
p, q, t, and u are each independently an integer from 1 to 100;
and r is an integer from 1 to 10.

In one embodiment of the present invention, the reactive silicone surfactant may be a silicone surfactant having an acrylate group at the end.

In one embodiment of the present invention, the reactive silicone surfactant may include one or more of the compounds represented by the following chemical formulas 2 to 3.

In the above formula,
R ¹ and R ² are each independently

and
^R3 is

and
L is a divalent or trivalent linking group having a urethane group,
Y and Z are each independently an ester group or a C ₁ -C ₆ oxyalkylene group;
^R4 and ^R5 are each independently a hydrogen atom or a methyl group;
g is an integer from 0 to 1;
h is an integer from 1 to 2,
k, l, m, i, and j are each independently an integer from 1 to 20.

In one embodiment of the present invention, the surfactant may be contained in an amount of 0.005 to 2% by weight based on 100% by weight of the total light conversion ink composition.

In one embodiment of the present invention, the reactive silicone surfactant may be included in an amount of 20% by weight or more based on 100% by weight of the total surfactant.

The light conversion ink composition according to one embodiment of the present invention may further include one or more selected from the group consisting of scattering particles, photopolymerization initiators, and antioxidants.

The light conversion ink composition according to one embodiment of the present invention may contain a solvent in an amount of 1% by weight or less.

On the other hand, the present invention provides a light conversion pixel comprising a cured product of the light conversion ink composition.

On the other hand, the present invention provides a color filter including the light conversion pixel.

On the other hand, the present invention provides an image display device characterized by being equipped with the above-mentioned color filter.

The light conversion ink composition according to the present invention contains quantum dots having polyethylene glycol-based ligands of a specific structure on the surface, and contains a reactive silicone surfactant as a surfactant that has excellent compatibility with the polyethylene glycol-based ligands and excellent reactivity with curable monomers, and can form a thick film that has excellent dispersibility of quantum dots and excellent optical properties of quantum dots even without substantially containing a solvent, and also improves the adhesion of the coating film. Therefore, the light conversion ink composition according to the present invention can be effectively used when manufacturing color filters by inkjet printing.

The present invention will be explained in more detail below.

In this invention, when a member is said to be "located on" another member, this does not only include the case where the member is in contact with the other member, but also the case where another member exists between the two members.

When a part in the present invention is said to "contain" a certain component, this does not mean that it excludes other components, but that it may further contain other components, unless otherwise specified.

One embodiment of the present invention relates to a light conversion ink composition that includes quantum dots (A), a curable monomer (B), and a surfactant (C), the quantum dots (A) having a ligand layer on the surface thereof that includes a polyethylene glycol-based ligand of a specific structure, and the surfactant (C) includes a reactive silicone-based surfactant.

Quantum dots (A)
In one embodiment of the present invention, the quantum dot has a ligand layer on its surface, the ligand layer including one or more of the compounds represented by the following formulas 1a to 1e:

In the above formula,
R' and R'' are each independently a hydrogen atom; a carboxyl group; a phenyl group; or a _C1 - _C20 alkyl group unsubstituted or substituted with a thiol group;
R′ and R″ are not simultaneously a hydrogen atom; a phenyl group; or an unsubstituted C ₁ -C ₂₀ alkyl group;
R ^a , R ^b , and R ^c are each independently a C ₁ to C ₂₂ alkyl group or a C ₄ to C ₂₂ alkenyl group;
R ^d is a C ₁ -C ₂₂ alkylene group, a C ₃ -C ₈ cycloalkylene group, or a C ₆ -C ₁₄ arylene group;
A and B are each independently absent, a C ₁ -C ₂₂ alkylene group, O, NR, or S;
R is hydrogen or a _C1 - _C22 alkyl group;
X is a carboxyl group, a phosphate group, a thiol group, an amine group, a tetrazole group, an imidazole group, a pyridine group, or a lipoamide group;
n is an integer from 1 to 20,
p, q, t, and u are each independently an integer from 1 to 100;
and r is an integer from 1 to 10.

As used herein, a C ₁ -C ₂₀ alkyl group means a straight or branched monovalent hydrocarbon group consisting of 1 to 20 carbon atoms, and includes, but is not limited to, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, n-decyl, and n-undecyl.

As used herein, a C ₁ -C ₂₂ alkyl group means a straight or branched monovalent hydrocarbon group consisting of 1 to 22 carbon atoms, and includes, but is not limited to, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, n-decyl, n-undecyl, n-docosanyl, and the like.

As used herein, C ₄ -C ₂₂ alkenyl group means a straight-chain or branched monovalent unsaturated hydrocarbon having 4 to 22 carbon atoms and one or more carbon-carbon double bonds, and examples include, but are not limited to, butenylene, pentenylene, hexenylene, heptenylene, octenylene, nonenylene, decenylene, undecenylene, dodecenylene, tridecenylene, tetradecenylene, pentadecenylene, hexadecenylene, heptadecenylene, octadecenylene, and the like.

The _C1 - _C20 alkyl group, _C1 - _C22 alkyl group, and _C4 - _C22 alkenyl group may have one or more hydrogens substituted with a _C1 -C6 alkyl group, a C2- _C6 alkenyl group, a _C2 -C6 alkynyl group, a _C3 - _C10 cycloalkyl group, a _C3 - _C10 heterocycloalkyl group, a _C3 - _C10 heterocycloalkyloxy group, _{a C1} - _{C6 haloalkyl} group, a _C1 - _C6 alkoxy group, a _C1 - _C6 thioalkoxy group, an aryl group, an acyl group, hydroxy, thio (thio), halogen, amino, alkoxycarbonyl, carboxy, carbamoyl, cyano, nitro, or _the like.

The compound represented by the formula 1a of the present invention may be a compound in which R' is a _C1 - _C20 alkyl group substituted or unsubstituted with a thiol group, and R'' is a carboxyl group, in terms of realizing optical properties and dispersibility of quantum dots and low viscosity.

In one embodiment of the present invention, specific examples of the compound represented by the chemical formula 1a include, but are not limited to, 2-(2-methoxyethoxy)acetic acid (manufactured by WAKO Corporation), 2-[2-(2-methoxyethoxy)ethoxy]acetic acid (manufactured by WAKO Corporation), {2-[2-(carboxymethoxy)ethoxy]ethoxy}acetic acid (manufactured by WAKO Corporation), 2-[2-(benzyloxy)ethoxy]acetic acid, (2-(carboxymethoxy)ethoxy)acetic acid (manufactured by WAKO Corporation), (2-butoxyethoxy)acetic acid (manufactured by WAKO Corporation), and carboxy-EG6-undecanethiol.

In terms of realizing the optical properties and dispersibility of quantum dots and low viscosity, the compound represented by Formula 1b of the present invention may be a compound in which R ^a is a C ₁ to C ₂₂ alkyl group or a C ₄ to C ₂₀ alkenyl group, and p is an integer from 1 to 50. In particular, if p in Formula 1b exceeds the above range, it may affect the viscosity of the light conversion ink composition.

The compound represented by the chemical formula 1b may have a thiol group, and the thiol group may be bonded to the surface of the quantum dot. The thiol group has a stronger bond with the surface of the quantum dot than ligand layer compounds such as carboxylic acids that are commonly used in quantum dots, and has the advantage of suppressing quenching due to surface defects such as dangling bonds of the quantum dots and quenching due to surface oxidation, thereby improving optical properties (luminescence properties) and reliability.

In one embodiment of the present invention, the compound represented by the chemical formula 1b may be one or more compounds selected from the compounds represented by the following chemical formulas 1-1 to 1-6 in terms of realizing the optical properties and dispersibility of quantum dots and low viscosity.

The compound represented by the chemical formula 1c of the present invention may be a compound in which q is an integer from 1 to 50 and r is an integer from 1 to 8, in terms of realizing the optical properties and dispersibility of quantum dots and low viscosity. In particular, when q and r in the chemical formula 1c exceed the above ranges, it may affect the viscosity of the light conversion ink composition.

The compound represented by formula 1c may have a thiol group, and the thiol group may be bound to the surface of the quantum dot. The thiol group has a stronger binding force with the surface of the quantum dot than ligand layer compounds of ordinary quantum dots, such as carboxylic acids, and has the advantage of suppressing quenching due to surface defects such as dangling bonds of the quantum dots and quenching due to surface oxidation, thereby improving optical properties (luminescence properties) and reliability.

In one embodiment of the present invention, the compound represented by the chemical formula 1c may be one or more compounds selected from the compounds represented by the following chemical formulas 1-7 to 1-12 in terms of realizing the optical properties and dispersibility of quantum dots and low viscosity.

In terms of realizing the optical properties and dispersibility of quantum dots and low viscosity, the compound represented by Formula 1d of the present invention may be a compound in which Rb is a _C1 to _C22 alkyl group or a _C4 to _C20 alkenyl group, and t is an integer from 1 to 50. In particular, when t in Formula 1d exceeds the above range, it may affect the viscosity of the light conversion ink composition.

The compound represented by formula 1d may have an amine group, and the amine group may be bonded to the surface of the quantum dot. The amine group has a stronger bond with the surface of the quantum dot than ligand layer compounds of ordinary quantum dots, such as carboxylic acids, and has the advantage of suppressing quenching due to surface defects such as dangling bonds of the quantum dots and quenching due to surface oxidation, thereby improving optical properties (luminescence properties) and reliability.

In one embodiment of the present invention, the compound represented by the chemical formula 1d may be one or more compounds selected from the compounds represented by the following chemical formulas 1-13 to 1-18 in terms of realizing the optical properties and dispersibility of quantum dots and low viscosity.

In terms of realizing the optical properties and dispersibility of quantum dots and low viscosity, the compound represented by the formula 1e of the present invention may be a compound in which Rc is a _C1 - _C22 alkyl group or a _C4 - _C22 alkenyl group, Rd is a _C1 - _C22 alkylene group, a _C3 - _C8 cycloalkylene group, or a _C6 - _C14 arylene group, A and B are each independently absent or a _C1 - _C22 alkylene group, O, NR, or S, R is hydrogen or a _C1 - _C22 alkyl group, X is a carboxyl group, a phosphate group, a thiol group, an amine group, a tetrazole group, an imidazole group, a pyridine group, or a lipoamide group, and u is an integer of 1 to 50. In particular, when u in the formula 1e exceeds the above range, it may affect the viscosity of the light conversion ink composition.

In one embodiment of the present invention, the compound represented by the chemical formula 1e may be one or more compounds selected from the compounds represented by the following chemical formulas 1-19 to 1-25 in terms of realizing the optical properties and dispersibility of quantum dots and low viscosity.

The compounds represented by the chemical formulas 1a to 1e of the present invention are organic ligands that may be coordinated to the surface of quantum dots to stabilize the quantum dots.

Quantum dots manufactured in general generally have a ligand layer on the surface, and the ligand layer immediately after manufacture is made of oleic acid, lauric acid, etc. In this case, the surface protection effect may be reduced due to non-bonding defects on the quantum dot surface caused by weaker binding force with the quantum dot than when the quantum dot according to the present invention contains the compound represented by the chemical formulas 1a to 1e as a ligand layer. In addition, oleic acid is easily dispersed in aliphatic hydrocarbon solvents such as n-hexane, which is a highly volatile compound (VOC), and aromatic hydrocarbon solvents such as benzene, but has poor dispersibility in solvents such as propylene glycol methyl ether acetate (PGMEA). The quantum dots according to the present invention contain the compound represented by the chemical formulas 1a to 1e as a ligand layer, and have excellent dispersibility in solvents such as PGMEA, thereby improving optical properties.

In addition, the quantum dots contain one or more polyethylene glycol-based ligands from among the compounds represented by chemical formulas 1a to 1e, and thus can exhibit good dispersion characteristics even when they contain substantially no solvent or only a small amount of solvent.

The compounds represented by the chemical formulas 1a to 1e may cover 5% or more of the total surface area of the quantum dots.

In this case, the content of the compounds represented by the chemical formulas 1a to 1e may be 0.1 to 10 moles per mole of quantum dots.

The ligand layer containing the compounds represented by the chemical formulas 1a to 1e may have a thickness of 0.1 nm to 2 nm, for example, 0.5 nm to 1.5 nm.

In one embodiment of the present invention, the quantum dots may refer to nano-sized semiconductor materials. Atoms form molecules, and the molecules form small molecular aggregates called clusters to form nanoparticles, and such nanoparticles are called quantum dots when they exhibit semiconductor properties. When the quantum dots receive energy from the outside and enter an excited state, they emit energy according to the energy band gap corresponding to the quantum dot itself. For example, the light conversion ink composition according to the present invention contains such quantum dots, and thus is capable of converting incident blue light into green light and red light.

In one embodiment of the present invention, the quantum dots may be non-cadmium quantum dots.

The non-cadmium quantum dots are not particularly limited as long as they are quantum dot particles that can emit light when stimulated by light. For example, they may be selected from the group consisting of II-VI group semiconductor compounds; III-V group semiconductor compounds; IV-VI group semiconductor compounds; IV group elements or compounds containing the same; and combinations thereof, and these may be used alone or in combination of two or more kinds.

Specifically, the II-VI group semiconductor compound may be selected from the group consisting of two-element compounds selected from the group consisting of ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; three-element compounds selected from the group consisting of ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and four-element compounds selected from the group consisting of HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof, but are not limited thereto.

The III-V semiconductor compound is a bi-element compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof. and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof, but are not limited thereto.

The IV-VI semiconductor compound may be one or more selected from the group consisting of two-element compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; three-element compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and four-element compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof, but is similarly not limited thereto.

The Group IV element or a compound containing the same may be, but is not limited to, an element selected from the group consisting of Si, Ge, and mixtures thereof; and a two-element compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

The quantum dots may have a homogeneous single structure; a double structure such as a core-shell or gradient structure; or a mixed structure thereof. Preferably, the quantum dots have a core-shell structure including a core and a shell covering the core.

Specifically, in the core-shell double structure, the materials constituting the core and shell may be made of different semiconductor compounds as described above. For example, the core may be made of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, G The shell may include, but is not limited to, one or more selected from the group consisting of ZnSe, ZnS, and ZnTe.

For example, core-shell quantum dots include InP/ZnS, InP/ZnSe, InP/GaP/ZnS, InP/ZnSe/ZnS, InP/ZnSeTe/ZnS, and InP/MnSe/ZnS.

The quantum dots may be synthesized by, but are not limited to, a wet chemical process, a metal organic chemical vapor deposition process (MOCVD), or a molecular beam epitaxy process (MBE), and are preferably synthesized by a wet chemical process, since this produces quantum dots with better optical properties.

The wet chemical process is a method of growing particles by putting precursor materials into an organic solvent. In the wet chemical process, as the crystals grow, the organic solvent naturally coordinates to the surface of the quantum dot crystals and acts as a dispersant to regulate the growth of the crystals, so the growth of nanoparticles can be controlled by a process that is easier and less expensive than gas phase deposition methods such as metalorganic chemical vapor deposition and molecular beam epitaxy. Therefore, it is preferable to manufacture the quantum dots using the wet chemical process.

When manufacturing quantum dots by wet chemical processes, organic ligands are used to suppress the aggregation of quantum dots and to control the particle size of quantum dots to the nano level. Oleic acid may generally be used as such an organic ligand.

In one embodiment of the present invention, the oleic acid used in the manufacturing process of the quantum dots is replaced by one or more polyethylene glycol-based compounds represented by the chemical formulas 1a to 1e by a ligand exchange method.

The ligand exchange may be performed by adding the organic ligand to be exchanged, i.e., one or more polyethylene glycol-based compounds among the compounds represented by formulae 1a to 1e, to a dispersion containing quantum dots having the original organic ligand, i.e., oleic acid, and stirring the mixture at room temperature to 200°C for 30 minutes to 3 hours to obtain quantum dots to which one or more polyethylene glycol-based compounds among the compounds represented by formulae 1a to 1e are bonded. If necessary, a process of separating and purifying the quantum dots to which one or more polyethylene glycol-based compounds among the compounds represented by formulae 1a to 1e are bonded may be further performed.

The quantum dots may be contained in the range of 1 to 60% by weight, preferably 5 to 50% by weight, based on 100% by weight of the total light conversion ink composition. When the quantum dots are contained within the above range, there are advantages in that the light emission efficiency is excellent and the reliability of the coating layer is excellent. When the quantum dots are contained below the above range, the light conversion efficiency may be insufficient, and when the quantum dots are contained above the above range, there may be a problem in that the emission of blue light is relatively reduced, resulting in poor color reproducibility.

Curable monomer (B)
In one embodiment of the present invention, the curable monomer (B) is a compound that can be polymerized by the action of light and a photopolymerization initiator described later, and includes a monofunctional monomer, a bifunctional monomer, and other polyfunctional monomers, and in particular, a compound represented by the following Chemical Formula 4 is preferred in terms of realizing low viscosity.

In the above formula,
R ⁶ is a C ₁ -C ₂₀ alkylene group, a phenylene group, or a C ₃ -C ₁₀ cycloalkylene group;
^R7 is hydrogen or a methyl group;
f is an integer from 1 to 15.

As used herein, a C ₁ -C ₂₀ alkylene group means a linear or branched divalent hydrocarbon having 1 to 20 carbon atoms, and examples include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, and n-nonylene.

As used herein, a _C3 - _C10 cycloalkylene group refers to a monocyclic or fused ring divalent hydrocarbon containing from 3 to 10 carbon atoms, including, but not limited to, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, and the like.

The _C1 - _C20 alkylene group, phenylene group, and _C3 - _C10 cycloalkylene group may have one or more hydrogens substituted with a _C1 - _C6 alkyl group, a C2- _C6 alkenyl group, a _C2 - _C6 alkynyl group, a _C3 -C10 cycloalkyl group, a _C3 - _C10 heterocycloalkyl group, a _C3 - _C10 heterocycloalkyloxy group, a _C1 - _{C6 haloalkyl} group, a _C1 - _C6 alkoxy group, a _C1 - _C6 thioalkoxy group, an aryl group, an acyl group, hydroxy, thio (thio), halogen, amino, alkoxycarbonyl, carboxy, carbamoyl, cyano, nitro, or _the like.

In one embodiment of the present invention, R ⁶ can be a C ₁ -C ₂₀ alkylene group.

Specific examples of the compound represented by chemical formula 4 include 1,6-hexanediol diacrylate, 1,9-bisacryloyloxynonane, and tripropylene glycol diacrylate.

In addition to the curable monomer represented by the chemical formula 4, the light conversion ink composition according to the present invention may further contain a curable monomer that is commonly used in the relevant field, within the limits of the purpose of the present invention. For example, monofunctional monomers, bifunctional monomers, and other polyfunctional monomers can be mentioned, and among these, bifunctional monomers are preferably used.

The type of the monofunctional monomer is not particularly limited, and examples thereof include nonylphenylcarbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexylcarbitol acrylate, 2-hydroxyethyl acrylate, and N-vinylpyrrolidone.

The type of the bifunctional monomer is not particularly limited, and examples thereof include bis(acryloyloxyethyl) ether of bisphenol A.
The type of the polyfunctional monomer is not particularly limited, and examples thereof 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, and dipentaerythritol hexa(meth)acrylate.

The curable monomer (B) may be contained in the range of 20 to 90% by weight, preferably 30 to 80% by weight, based on 100% by weight of the total light conversion ink composition. When the curable monomer is contained within the above range, it has the advantage of being preferable in terms of the strength and smoothness of the pixel part. When the curable monomer is contained below the above range, the strength of the pixel part may be slightly decreased, and when the curable monomer is contained above the above range, the smoothness may be slightly decreased, so it is preferable that the curable monomer is contained within the above range.

Surfactant (C)
In one embodiment of the invention, the surfactant comprises a reactive silicone based surfactant.

The reactive silicone surfactant is a compound having a reactive group that can be polymerized by active radicals, acids, etc. generated from a photopolymerization initiator when irradiated with light, and the reactive group reduces offset caused by the aggregation of quantum dots even when a thick film containing a large amount of quantum dots is formed, preventing a decrease in luminous efficiency and improving the adhesion of the coating film. In addition, the reactive silicone surfactant has excellent compatibility with the polyethylene glycol ligand and excellent reactivity with the curable monomer, improving the dispersibility, sensitivity, and processability of the light conversion ink composition.

The reactive silicone surfactant may be a silicone surfactant having an acrylate group at the end. For example, the reactive silicone surfactant may be a silicone surfactant having one or more, preferably 1 to 8, and more preferably 1 to 4, acrylate groups at the end.

Specifically, the reactive silicone surfactant is a compound having a siloxane bond and a reactive acrylate group at its end, and may include one or more of the compounds represented by the following chemical formulas 2 to 3.

In the above formula,
R ¹ and R ² are each independently

and
^R3 is

and
L is a divalent or trivalent linking group having a urethane group,
Y and Z are each independently an ester group or a C ₁ -C ₆ oxyalkylene group;
R4 and ^R5 are each independently a hydrogen atom or a methyl group;
g is an integer from 0 to 1;
h is an integer from 1 to 2,
k, l, m, i, and j are each independently an integer from 1 to 20.

As used herein, the term "C ₁ -C ₆ oxyalkylene group" refers to a functional group in which one or more of the chain carbons in a linear or branched divalent hydrocarbon having 1 to 6 carbon atoms are substituted with oxygen, and examples of such groups include, but are not limited to, oxymethylene, oxyethylene, oxypropylene, oxybutylene, oxypentylene, and oxyhexylene.

The urethane group, ester group, and _C1 - _C6 oxyalkylene group may have one or more hydrogens substituted with a _C1 - _C6 alkyl group, a _{C2-C6 alkenyl group, a C2 -} C6 alkynyl group, a _C3 - _C10 cycloalkyl group _, a _C3 - _C10 heterocycloalkyl group, a _C3 - _C10 heterocycloalkyloxy group, a _C1 -C6 haloalkyl group _, a _C1 - _C6 alkoxy group, a _C1 - _C6 thioalkoxy group, an aryl group, an acyl group, hydroxy, thio, halogen, amino, alkoxycarbonyl, carboxy, carbamoyl, cyano, nitro, or _the like.

Commercially available reactive silicone surfactants include, for example, BYK-UV3570, BYK-UV3530, BYK-UV3500 (all manufactured by BYK), TEGO Rad 2100, TEGO Rad 2200N, TEGO Rad 2250, TEGO Rad 2300, TEGO Rad 2500, TEGO Rad 2600, and TEGO Rad 2700 (all manufactured by Degussa).

The surfactant may further include a surfactant generally used in the technical field in addition to the reactive silicone surfactant. Examples of such additional surfactants include commercially available products such as DC3PA, DC7PA, SH11PA, SH21PA, and SH8400 manufactured by Dow Corning Toray Silicones, non-reactive silicone surfactants such as TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, and TSF-4452 manufactured by GE Toshiba Silicones, and fluoro-surfactants such as Megafac F-470, F-471, F-475, F-482, F-489, and F-554 manufactured by Dainippon Ink and Chemicals, Inc.

The surfactant may be contained in the range of 0.005 to 2% by weight, preferably 0.01 to 1.5% by weight, based on 100% by weight of the total light conversion ink composition. When the surfactant is contained within the above range, the flatness of the coating film is improved. When the surfactant is contained less than the above range, the ink composition may not spread or flatten sufficiently, resulting in increased surface roughness and the formation of craters on the surface. When the surfactant is contained more than the above range, the ink composition may spread excessively, causing the ink exposed from the nozzle to overflow or splash onto the partition surface and adjacent openings, resulting in contamination.

The reactive silicone surfactant may be contained in an amount of 20% by weight or more, preferably 30% by weight or more, based on 100% by weight of the total surfactant. When the reactive silicone surfactant is contained within the above range, it is substituted on the shell surface of the quantum dots, improving the dispersion stability of the quantum dots in a thick film and increasing the adhesion. When it is contained below the above range, the optical properties of the quantum dots in a thick film may be reduced and the adhesion of the coating film may also be reduced.

Scattering Particles (D)
The light conversion ink composition according to one embodiment of the present invention may further comprise scattering particles (D).

The scattering particles increase the path of light emitted from the quantum dots, thereby increasing the overall light efficiency.

The scattering particles may be made of a normal inorganic material, preferably a metal oxide.

The metal oxide may be an oxide containing one 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.

Specifically, it _may be one selected from the _group consisting of _Al2O3 , _SiO2 , _{ZnO, ZrO2, BaTiO3, TiO2, Ta2O5, Ti3O5 , ITO , IZO , ATO} , ZnO-Al, _Nb2O3 , SnO, MgO, and combinations thereof. If necessary, a material that has been surface-treated with a compound having an unsaturated bond, such as acrylate, may also be used.

The scattering particles may have an average particle size of 50 to 1000 nm, preferably 100 to 500 nm, and more preferably 150 to 300 nm. If the particle size is too small, sufficient scattering effect of the light emitted from the quantum dots cannot be expected, and conversely, if the particle size is too large, the particles may sink in the composition and a uniform quality of the light conversion layer surface cannot be obtained, so the particle size is appropriately adjusted within the above range.

In the present invention, the average particle size may refer to the number average particle size, and can be determined, for example, from images observed with a field emission scanning electron microscope (FE-SEM) or a transmission electron microscope (TEM). Specifically, it can be obtained by extracting several samples from the FE-SEM or TEM observation images, measuring the diameters of these samples, and taking the arithmetic average value.

The scattering particles may be contained in the range of 0.5 to 20% by weight, preferably 1 to 15% by weight, based on 100% by weight of the total light conversion ink composition. When the scattering particles are contained within the above range, the effect of increasing the luminous intensity is maximized, which is preferable. If the scattering particles are contained below the above range, it may be somewhat difficult to ensure the desired luminous intensity, and if the scattering particles are contained above the above range, the transmittance of blue irradiation light decreases, which may cause problems with luminous efficiency.

Photopolymerization initiator (E)
The photoconversion ink composition according to one embodiment of the present invention may further contain a photopolymerization initiator (E).

In one embodiment of the present invention, the photopolymerization initiator (E) may be used without any particular limitation as long as it can polymerize the curable monomer. In particular, from the viewpoints of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc., it is preferable to use one or more compounds selected from the group consisting of acetophenone-based compounds, benzophenone-based compounds, triazine-based compounds, biimidazole-based compounds, oxime-based compounds, and thioxanthone-based compounds as the photopolymerization initiator.

The photopolymerization initiator may be contained in the range of 0.01 to 20% by weight, preferably 0.5 to 15% by weight, relative to 100% by weight of the total photoconversion ink composition. When the photopolymerization initiator is contained within the above range, the photoconversion ink composition becomes highly sensitive, shortening the exposure time and improving productivity, which is preferable. In addition, there is an advantage in that the strength of the pixel portion formed using the photoconversion ink composition according to the present invention and the smoothness of the surface of the pixel portion are improved.

The photopolymerization initiator (E) may further contain a photopolymerization initiator assistant (e1) in order to improve the sensitivity of the photoconversion ink composition according to the present invention. The inclusion of the photopolymerization initiator assistant has the advantage of further increasing the sensitivity and improving productivity.

The photopolymerization initiator aid (e1) may be, for example, one or more compounds selected from the group consisting of amine compounds, carboxylic acid compounds, and organic yellow compounds having a thiol group, but is not limited thereto.

The photopolymerization initiator aid (e1) may be added as needed within the range that does not impair the effects of the present invention.

Additive (F)
The light conversion ink composition according to one embodiment of the present invention may further contain additives in addition to the above-mentioned components.

The additives may be antioxidants, photoacid generators, thermal acid generators, dispersants, fillers, curing agents, adhesion promoters, etc., which may be used alone or in combination of two or more.
The additive may be used in a range of 0.05 to 10 wt %, specifically 0.1 to 10 wt %, and more specifically 0.1 to 5 wt %, relative to 100 wt % of the total weight of the light conversion ink composition, but is not limited thereto.

The light conversion ink composition according to one embodiment of the present invention is substantially free of solvent, and if it does contain a solvent, it is contained in an amount of 1 wt% or less relative to 100 wt% of the total light conversion ink composition. The light conversion ink composition according to one embodiment of the present invention is a solvent-free type that does not contain a solvent, or a low-solvent type that contains a very small amount of solvent, 1 wt% or less, yet it is possible to realize excellent optical properties and dispersibility of quantum dots and low viscosity.

In addition, the light conversion ink composition according to one embodiment of the present invention does not substantially contain a resin component, and even if it does contain a resin component, it contains less than 0.5% by weight based on 100% by weight of the total light conversion ink composition. Since the light conversion ink composition according to one embodiment of the present invention does not contain a resin component, it can realize low viscosity and has excellent nozzle jetting characteristics of the ink.

One embodiment of the present invention relates to a light conversion pixel that includes a cured product of the light conversion ink composition described above.

An embodiment of the present invention relates to a color filter including the above-mentioned light conversion pixel.

The pattern forming method of the photoconversion ink composition according to the present invention comprises the steps of applying the above-mentioned photoconversion ink composition to a predetermined area by an inkjet method, and curing the applied photoconversion ink composition.

First, the photoconversion ink composition of the present invention is injected into an inkjet printer to print a predetermined area of a substrate.

The substrate is not limited, and examples include substrates with flat surfaces such as glass substrates, silicon substrates, polycarbonate substrates, polyester substrates, aromatic polyamide substrates, polyamideimide substrates, polyimide substrates, Al substrates, and GaAs substrates. These substrates may be pretreated with chemicals such as silane coupling agents, plasma treatments, ion plating treatments, sputtering treatments, gas phase reaction treatments, and vacuum deposition treatments. When a silicon substrate or the like is used as the substrate, a charge-coupled device (CCD), thin film transistor (TFT), or the like may be provided on the surface of the silicon substrate or the like. A partition matrix may also be provided.

In order for ink to be sprayed from a piezoelectric inkjet head, which is an example of an inkjet sprayer, and to form an appropriate phase on a substrate, the properties of the viscosity, fluidity, quantum dot particles, etc. must be balanced with the inkjet head. The piezoelectric inkjet head used in the present invention sprays ink with a droplet size of about 10 to 100 pL, preferably about 20 to 40 pL, although there is no particular limitation.

The viscosity of the light conversion ink composition according to the present invention is preferably adjusted to about 3 to 30 cP, and more preferably to within the range of 7 to 20 cP.

A color filter according to one embodiment of the present invention includes a colored pattern layer formed by the pattern forming method. That is, the color filter is characterized by including a colored pattern layer formed by applying the above-mentioned light conversion ink composition in a predetermined pattern on a substrate and then curing it. The configuration and manufacturing method of the color filter are well known in the art, so a detailed description thereof will be omitted.

One embodiment of the present invention relates to an image display device including the above-mentioned color filter.
The color filter according to the present invention can be applied to various image display devices, such as not only ordinary liquid crystal display devices (LCDs), but also electroluminescence display devices (ELs), plasma display devices (PDPs), field emission display devices (FEDs), and organic light emitting devices (OLEDs).

The image display device according to the present invention includes a configuration that is well known in the art, except that it is equipped with the color filters described above.

Hereinafter, the present invention will be described in more detail with reference to examples, comparative examples, and experimental examples. Note that it will be obvious to those skilled in the art that these examples, comparative examples, and experimental examples are merely for the purpose of explaining the present invention, and that the scope of the present invention is not limited to these examples, comparative examples, and experimental examples.

Synthesis Example 1: Synthesis of Ligand-Substituted Quantum Dots (A1) 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 at 280° C., a mixed solution of 0.2 mmol (58 μl) of tris(trimethylsilyl)phosphine (TMS3P) and 1.0 mL of trioctylphosphine was quickly injected and reacted for 1 minute.

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 to 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 selenium in trioctylphosphine (Se/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution, which was quickly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and dried under reduced pressure to form an InP/ZnSe core-shell.

Next, 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 to 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/ZnSe core-shell solution was added, followed by 4.8 mmol of sulfur in trioctylphosphine (S/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution that was quickly cooled to room temperature, and the precipitate obtained by centrifuging was filtered under reduced pressure and dried under reduced pressure to obtain quantum dots with an InP/ZnSe/ZnS core-shell structure, which were then dispersed in chloroform.

The maximum emission peak of the optical emission spectrum of the obtained nano quantum dots was 535 nm. 5 mL of the quantum dot solution was placed in a centrifuge tube, and 20 mL of ethanol was added to cause precipitation. The upper layer was discarded by centrifugation, and 2 mL of chloroform was added to the precipitate to disperse the quantum dots. After that, 0.50 g of (2-butoxyethoxy)acetic acid was added and reacted for one hour while heating at 60°C under a nitrogen atmosphere.

Next, 25 mL of n-hexane was added to the reaction mixture to precipitate the quantum dots, and the mixture was then centrifuged to obtain a precipitate.

Synthesis Example 2: Synthesis of Ligand-Substituted Quantum Dots (A2) 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 at 280° C., a mixed solution of 0.2 mmol (58 μl) of tris(trimethylsilyl)phosphine (TMS3P) and 1.0 mL of trioctylphosphine was quickly injected, and after 5 minutes of reaction, the reaction solution was quickly cooled to room temperature. The maximum absorption wavelength was 560-590 nm.

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 to 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 selenium in trioctylphosphine (Se/TOP), and the final mixture was reacted for 2 hours before being cooled to room temperature to form an InP/ZnSe core-shell.

Next, 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 to 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/ZnSe core-shell solution was added, followed by 4.8 mmol of sulfur in trioctylphosphine (S/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution, which was quickly cooled to room temperature, and the precipitate obtained by centrifuging was filtered under reduced pressure and dried under reduced pressure to obtain quantum dots with an InP/ZnSe/ZnS core-shell structure, which were then dispersed in chloroform.

The maximum emission peak of the optical emission spectrum of the obtained nano quantum dots was 635 nm. 5 mL of the synthesized quantum dot solution was placed in a centrifuge tube, and 20 mL of ethanol was added to cause precipitation. The upper layer was discarded by centrifugation, and 2 mL of chloroform was added to the precipitate to disperse the quantum dots. 0.65 g of carboxy-EG6-undecanethiol was then added and reacted for one hour while heating at 60°C under a nitrogen atmosphere.

Next, 25 mL of n-hexane was added to the reaction mixture to precipitate the quantum dots, and then the mixture was centrifuged to discard the supernatant and obtain the precipitate.

Synthesis Example 3: Synthesis of Ligand-Substituted Quantum Dots (A3) 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 at 280°C, a mixture of 0.2 mmol (58 μl) of tris(trimethylsilyl)phosphine (TMS3P) and 1.0 mL of trioctylphosphine was quickly injected and allowed to react for 0.5 minutes.

Next, 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 to 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 selenium in trioctylphosphine (Se/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution, which was quickly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and dried under reduced pressure to form an InP/ZnSe core-shell.

Next, 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 to 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/ZnSe core-shell solution was added, followed by 4.8 mmol of sulfur in trioctylphosphine (S/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution that was quickly cooled to room temperature, and the precipitate obtained by centrifuging was filtered under reduced pressure and dried under reduced pressure to obtain quantum dots with an InP/ZnSe/ZnS core-shell structure, which were then dispersed in chloroform. The solid content was adjusted to 10%. The maximum emission wavelength was 520 nm.

5 mL of the synthesized quantum dot solution was placed in a centrifuge tube, and 20 mL of ethanol was added to cause precipitation. The supernatant was discarded by centrifugation, and 3 mL of chloroform was added to the precipitate to disperse the quantum dots. 1.00 g of mPEG5-SH (FutureChem) represented by the following chemical formula 1-1 was then added and reacted for one hour while heating at 60°C under a nitrogen atmosphere.

Next, 25 mL of n-hexane was added to the reaction mixture to precipitate the quantum dots, and the mixture was then centrifuged to discard the supernatant and obtain the precipitate.

Synthesis Example 4: Synthesis of ligand-substituted quantum dots (A4) Synthesis Example 3 was repeated, except that mPEG7-SH (FutureChem) represented by the following chemical formula 1-2 was used instead of the ligand used in Synthesis Example 3.

Synthesis Example 5: Synthesis of ligand-substituted quantum dots (A5) Synthesis Example 5 was carried out in the same manner as Synthesis Example 3, except that the compound represented by the following Chemical Formula 1-3 was used instead of the ligand used in Synthesis Example 3.

Synthesis Example 6: Synthesis of ligand-substituted quantum dots (A6) The same procedure as in Synthesis Example 3 was repeated, except that the ligand used in Synthesis Example 3 was replaced with a compound represented by the following formula 1-4.

Synthesis Example 7: Synthesis of ligand-substituted quantum dots (A7) Synthesis Example 7 was carried out in the same manner as Synthesis Example 3, except that the ligand used in Synthesis Example 3 was replaced with a compound represented by the following Chemical Formula 1-5.

Synthesis Example 8: Synthesis of ligand-substituted quantum dots (A8) The same procedure as in Synthesis Example 3 was repeated, except that the ligand used in Synthesis Example 3 was replaced with a compound represented by the following formula 1-6.

Synthesis Example 9: Synthesis of Ligand-Substituted Quantum Dots (A9) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Formula 1-7 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 10: Synthesis of Ligand-Substituted Quantum Dots (A10) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Formula 1-8 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 11: Synthesis of Ligand-Substituted Quantum Dots (A11) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-9 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 12: Synthesis of Ligand-Substituted Quantum Dots (A12) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-10 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 13: Synthesis of ligand-substituted quantum dots (A13) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-11 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 14: Synthesis of ligand-substituted quantum dots (A14) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-12 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 15: Synthesis of Ligand-Substituted Quantum Dots (A15) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-13 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 16: Synthesis of ligand-substituted quantum dots (A16) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-14 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 17: Synthesis of Ligand-Substituted Quantum Dots (A17) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-15 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 18: Synthesis of ligand-substituted quantum dots (A18) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-16 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 19: Synthesis of Ligand-Substituted Quantum Dots (A19) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-17 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 20: Synthesis of ligand-substituted quantum dots (A20) The same procedure as in Synthesis Example 3 was repeated, except that 3.00 g of a compound represented by the following formula 1-18 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 21: Synthesis of Ligand-Substituted Quantum Dots (A21) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-19 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 22: Synthesis of Ligand-Substituted Quantum Dots (A22) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following Chemical Formula 1-20 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 23: Synthesis of ligand-substituted quantum dots (A23) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-21 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 24: Synthesis of ligand-substituted quantum dots (A24) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-22 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 25: Synthesis of ligand-substituted quantum dots (A25) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-23 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 26: Synthesis of ligand-substituted quantum dots (A26) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-24 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Synthesis Example 27: Synthesis of ligand-substituted quantum dots (A27) The same procedure as in Synthesis Example 3 was carried out, except that 3.00 g of a compound represented by the following formula 1-25 was used instead of 1.00 g of the ligand used in Synthesis Example 3.

Comparative Synthesis Example 1: Synthesis of Ligand-Substituted Quantum Dots (A28) 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 at 280° C., a mixed solution of 0.2 mmol (58 μl) of tris(trimethylsilyl)phosphine (TMS3P) and 1.0 mL of trioctylphosphine was quickly injected, and after 5 minutes of reaction, the reaction solution was quickly cooled to room temperature. The maximum absorption wavelength was 560-590 nm.

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 to 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 selenium in trioctylphosphine (Se/TOP), and the final mixture was reacted for 2 hours before being cooled to room temperature to form an InP/ZnSe core-shell.

Next, 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 to 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/ZnSe core-shell solution was added, followed by 4.8 mmol of sulfur in trioctylphosphine (S/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution that was quickly cooled to room temperature, and the precipitate obtained by centrifuging was filtered under reduced pressure and dried under reduced pressure to obtain quantum dots with an InP/ZnSe/ZnS core-shell structure.

Comparative Synthesis Example 2: Synthesis of Ligand-Substituted Quantum Dots (A29) 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 at 280° C., a mixed solution of 0.2 mmol (58 μl) of tris(trimethylsilyl)phosphine (TMS3P) and 1.0 mL of trioctylphosphine was quickly injected and reacted for 0.5 minutes.

Next, 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 to 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 selenium in trioctylphosphine (Se/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution, which was quickly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and dried under reduced pressure to form an InP/ZnSe core-shell.

Next, 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 to 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/ZnSe core-shell solution was added, followed by 4.8 mmol of sulfur in trioctylphosphine (S/TOP), and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution that was quickly cooled to room temperature, and the precipitate obtained by centrifuging was filtered under reduced pressure and dried under reduced pressure to obtain quantum dots with an InP/ZnSe/ZnS core-shell structure.

Comparative Synthesis Example 3: Synthesis of Ligand-Substituted Quantum Dots (A30) The same procedure as in Synthesis Example 3 was repeated, except that the ligand used in Synthesis Example 3 was replaced with a compound represented by the following formula a (1-dodecanethiol).
[Chemical formula a]
_CH3 ( _CH2 ) _{10CH2SH .}

Comparative Synthesis Example 4: Synthesis of Ligand-Substituted Quantum Dots (A31) The same procedure as in Synthesis Example 3 was repeated, except that the ligand used in Synthesis Example 3 was replaced with a compound represented by the following formula b.
[Chemical Formula b]
_{H2NCH2 ( CH2 ) 9CH2NH2 .}

Production Example 1: Production of scattering particle dispersion liquid (C1) 70.0 parts by weight of TiO2 (CR-63 manufactured by Ishihara Sangyo Kaisha) having a particle size of 210 nm as scattering particles, 4.0 parts by weight of DISPERBYK-2001 (manufactured by BYK Corporation) as a dispersant, and 26 parts by weight of 1,6-hexanediol diacrylate as a solvent were mixed and dispersed in a bead mill for 12 hours to produce a scattering particle dispersion liquid (C1).

Examples and Comparative Examples: Preparation of Light-Converting Ink Compositions Light-converting ink compositions were prepared by mixing the components according to the compositions in Tables 1 to 4 below (wt %).

A1 to A31: Quantum dots produced in Synthesis Examples 1 to 27 and Comparative Synthesis Examples 1 to 4 B1: 1,6-hexanediol diacrylate (Sigma-Aldrich)
C1: Reactive silicone surfactant BYK-UV3570 (manufactured by BYK)
C2: Reactive silicone surfactant BYK-UV3530 (manufactured by BYK)
C3: Fluorosurfactant F-554 (manufactured by Dainippon Ink and Chemicals, Inc.)
C4: Non-reactive silicone surfactant SH8400 (manufactured by Toray Silicone Co., Ltd.)
D1: Scattering particle dispersion liquid produced in Production Example 1 E1: Irgacure OXE-01 (manufactured by BASF)
F1: Sumilizer GP (Sumitomo Chemical Co., Ltd.).

Experimental example:
A light conversion coating layer was prepared using the light conversion ink compositions prepared in the above examples and comparative examples as described below, and the film thickness, brightness, dispersibility, and viscosity were measured as described below. The results are shown in Tables 5 to 6 below.

<Production of light conversion coating layer>
Each of the light conversion ink compositions prepared in the examples and comparative examples was applied onto a 5 cm x 5 cm glass substrate by the inkjet method, and then irradiated with 1000 mJ/ ^cm2 using a 1 kW high pressure mercury lamp containing g, h, and i rays as an ultraviolet light source, and then heated in a heating oven at 180°C for 30 minutes to prepare a light conversion coating layer.

(1) Film Thickness The film thickness of the light conversion coating layer produced above was measured using a film thickness measuring device (Dektak 6M, manufactured by Vecco).

(2) Brightness The prepared light conversion coating layer was placed on a blue light source (XLamp XR-E LED, Royal blue 450, manufactured by Cree), and the brightness when irradiated with blue light was measured using a brightness measuring device (CAS140CT Spectrometer, manufactured by Instrument Systems).

(3) Dispersibility In the process of producing the light-converting ink composition, a liquid sample before adding the scattering particles was visually observed and evaluated according to the following evaluation criteria.
<Evaluation criteria>
○: Transparent state ×: Cloudy state

(4) Adhesion The adhesion of the light conversion coating layer prepared above was evaluated using a Cross Cut Adhesion Test CC1000 manufactured by TQC. The surface of the light conversion coating layer was cut by drawing 11 lines in the horizontal and vertical directions at intervals of 1 mm to generate a total of 100 lattices, and the adhesion of the cut surface was evaluated using a tape manufactured by TQC. At this time, the adhesion was evaluated according to the following evaluation criteria.
<Evaluation criteria>
○: Maintains 90 or more patterns △: Maintains 60 to 89 patterns ×: Maintains 59 or less patterns

As shown in Tables 5 and 6, it was confirmed that the light conversion ink compositions of Examples 1 to 30, which contain quantum dots having the polyethylene glycol-based ligands according to the present invention and a reactive silicone-based surfactant as a surfactant, can form a 10 μm thick film that has excellent dispersibility and excellent optical properties of the quantum dots even without substantially containing a solvent, and that the adhesion of the coating film is improved. In contrast, it was confirmed that the light conversion ink compositions of Comparative Examples 1 to 2 and 13 to 14, which contain quantum dots not having the polyethylene glycol-based ligands according to the present invention, and Comparative Examples 3 to 12, which do not contain a reactive silicone-based surfactant as a surfactant, are difficult to ensure dispersibility, brightness, and adhesion at the same time.

Although specific aspects of the present invention have been described in detail above, it will be clear to anyone with ordinary knowledge in the technical field to which the present invention pertains that these specific descriptions are merely preferred examples and do not limit the scope of the present invention. Anyone with ordinary knowledge in the technical field to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above content.

Therefore, the true scope of the present invention is defined by the claims and their equivalents.

Claims (9)

A light conversion ink composition comprising quantum dots, a curable monomer, and a surfactant,
The quantum dot has a ligand layer on its surface, the ligand layer including one or more of the compounds represented by the following chemical formulas 1a to 1e:
The surfactant comprises a reactive silicone surfactant;
A light conversion ink composition comprising a solvent in an amount of 1% by weight or less relative to 100% by weight of the total of the light conversion ink composition:

In the above formula,
R' and R'' are each independently a hydrogen atom; a carboxyl group; a phenyl group; or a _C1 - _C20 alkyl group unsubstituted or substituted with a thiol group;
R′ and R″ are not simultaneously a hydrogen atom; a phenyl group; or an unsubstituted C ₁ -C ₂₀ alkyl group;
R ^a , R ^b , and R ^c are each independently a C ₁ to C ₂₂ alkyl group or a C ₄ to C ₂₂ alkenyl group;
R ^d is a C ₁ -C ₂₂ alkylene group, a C ₃ -C ₈ cycloalkylene group, or a C ₆ -C ₁₄ arylene group;
A and B are each independently absent, a C ₁ -C ₂₂ alkylene group, O, NR, or S;
R is hydrogen or a _C1 - _C22 alkyl group;
X is a carboxyl group, a phosphate group, a thiol group, an amine group, a tetrazole group, an imidazole group, a pyridine group, or a lipoamide group;
n is an integer from 1 to 20,
p, q, t, and u are each independently an integer from 1 to 100;
and r is an integer from 1 to 10. The light conversion ink composition according to claim 1, wherein the reactive silicone surfactant is a silicone surfactant having an acrylate group at the end. The light conversion ink composition according to claim 1, wherein the reactive silicone surfactant comprises one or more of the compounds represented by the following chemical formulas 2 to 3:

In the above formula,
R ¹ and R ² are each independently

and
^R3 is

and
L is a divalent or trivalent linking group having a urethane group,
Y and Z are each independently an ester group or a C ₁ -C ₆ oxyalkylene group;
^R4 and ^R5 are each independently a hydrogen atom or a methyl group;
g is an integer from 0 to 1;
h is an integer from 1 to 2,
k, l, m, i, and j are each independently an integer from 1 to 20. The light conversion ink composition according to claim 1, wherein the surfactant is contained in an amount of 0.005 to 2% by weight relative to 100% by weight of the total light conversion ink composition. The light conversion ink composition according to claim 1, wherein the reactive silicone surfactant is contained in an amount of 20% by weight or more relative to 100% by weight of the total surfactant. The light conversion ink composition according to claim 1, further comprising one or more selected from the group consisting of scattering particles, photopolymerization initiators, and antioxidants. A light conversion pixel comprising a cured product of the light conversion ink composition according to any one of claims 1 to 6 . A color filter comprising the light conversion pixel of claim 7 . An image display device comprising the color filter according to claim 8 .