KR20230113051A - A quantum dot, a quantum dot dispersion, a light converting curable composition, a cured film manufactured by the composition and a display device comprising the cured film - Google Patents

Abstract

The present invention relates to a quantum dot having a ligand layer on the surface thereof. Provided are a quantum dot having a ligand layer including a compound having a specific chemical structure, a quantum dot dispersion containing the same, and a light conversion curable composition. The quantum dot and the light conversion curable composition containing the same according to the present invention are excellent in light conversion efficiency, heat resistance, viscosity stability, and film hardness, and can be effectively applied to various applications such as quantum dot films, quantum dot light-emitting diodes, color filters, and light conversion layered substrates. Therefore, a high-quality image display device can be provided.

Description

Quantum dots, quantum dot dispersions, light conversion curable compositions, cured films formed using the compositions, and image display devices including the cured films COMPOSITION AND A DISPLAY DEVICE COMPRISING THE CURED FILM}

The present invention relates to quantum dots, a quantum dot dispersion containing the quantum dots, a light conversion curable composition, a cured film formed using the light conversion curable composition, and an image display device including the cured film.

Quantum dots have high luminescence and a narrow luminescence spectrum, can control the luminescence wavelength with one excitation wavelength, and have the inherent characteristics of quantum dots that are stable against light. A lot of research has been done to use it in the same important application field.

These quantum dots are materials that are very sensitive to the surface state, and oxidation occurs from the surface depending on the solvent or surrounding environment in which they are dispersed, resulting in a sharp decrease in luminous efficiency. For various applications of quantum dots, they must be dispersed in various solvents other than the organic solvent in which they were originally dispersed or must form specific functional groups on the surface. These processes damage the surface of quantum dots and eventually lead to a decrease in luminous efficiency. there is

Many attempts have been made to overcome these problems, and various methods are currently being proposed. One of them is a functional group substitution (ligand exchange) method in which organic materials present on the surface of quantum dots are replaced with molecules having a desired functional group. This method is a method of substituting organic molecules present on the surface of quantum dots with organic molecules suitable for application, but has a disadvantage of causing fatal problems in luminous efficiency because it directly affects the surface of quantum dots.

Korean Patent Publication No. 10-2018-0002716 and Korean Patent Registration No. 10-1628065 disclose quantum dots including ligands disposed on the surface, but have low compatibility, poor dispersibility, and poor light conversion efficiency and heat resistance. There are problems such as insufficient stability and insufficient viscosity stability, making it unsuitable for the inkjet method.

Republic of Korea Patent Publication No. 10-2018-0002716 Republic of Korea Patent No. 10-1628065

An object of the present invention is to provide a quantum dot for a light conversion curable composition having excellent light conversion efficiency, heat resistance, viscosity stability and coating film hardness.

In addition, an object of the present invention is to provide a quantum dot dispersion and a light conversion curable composition containing the quantum dots.

In addition, an object of the present invention is to provide a cured film formed using the photoconversion curable composition and an image display device including the cured film.

The present invention provides a quantum dot having a ligand layer on its surface, wherein the ligand layer includes a compound represented by Formula 1 below.

[Formula 1]

(In Formula 1, A is a thiol group, an amino group, an imidazole group or a carboxyl group, L is a thiol group, an amino group, or a carboxyl group, R is a trivalent hydrocarbon group having 1 to 20 carbon atoms and a linear or branched chain, and X Is a direct bond, -OC(=O)-, -C(=O)O-, -C(=O)NH- or -HNC(=O)-, and Y is a straight chain or branched chain having 1 to 20 carbon atoms of alkanediyl group, , , or And, n is an integer of 1 to 15, m is an integer of 1 to 10, Z is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a carbon number 2 to 20 is a photopolymerization reactive group of However, there is no case where A and L are thiol groups at the same time.)

In addition, the present invention provides a quantum dot dispersion and a light conversion curable composition containing the quantum dots.

In addition, the present invention provides a cured film formed using the light conversion curable composition and an image display device including the cured film.

The quantum dot according to the present invention includes a compound represented by a specific chemical structure as a ligand layer, and the compound has two reactive sites that can act as anchors, which are positions that bind to the quantum dots, and can increase reactivity with the quantum dots, When both reactive sites bind to the quantum dots, the stability of the quantum dots can be further improved.

In addition, since the quantum dots and the light conversion curable composition including them provide excellent effects in light conversion efficiency, heat resistance, viscosity stability and coating film hardness, they are suitable for various uses such as quantum dot films, quantum dot light emitting diodes, color filters, and light conversion laminated base materials. It can be effectively applied, and thus a high-quality image display device can be provided.

The present invention provides a quantum dot having a ligand layer on its surface, wherein the ligand layer includes a compound represented by Formula 1 below.

[Formula 1]

(In Formula 1, A is a thiol group, an amino group, an imidazole group or a carboxyl group, L is a thiol group, an amino group, or a carboxyl group, R is a trivalent hydrocarbon group having 1 to 20 carbon atoms and a linear or branched chain, and X Is a direct bond, -OC(=O)-, -C(=O)O-, -C(=O)NH- or -HNC(=O)-, and Y is a straight chain or branched chain having 1 to 20 carbon atoms of alkanediyl group, , , or And, n is an integer of 1 to 15, m is an integer of 1 to 10, Z is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a carbon number 2 to 20 is a photopolymerization reactive group of However, there is no case where A and L are thiol groups at the same time.)

The quantum dot according to the present invention includes the compound represented by Chemical Formula 1 as a ligand layer, and the compound represented by Chemical Formula 1 has two reactive sites that can act as anchors, which are positions that bind to quantum dots, thereby reducing reactivity with quantum dots. If both reaction sites are combined with the quantum dots, the stability of the quantum dots can be further improved.

In addition, the present invention provides a quantum dot dispersion containing the quantum dots and at least one of a photopolymerizable monomer and a solvent.

In addition, the present invention provides a light conversion curable composition containing the quantum dot dispersion, a cured film formed using the same, and an image display device including the cured film.

Hereinafter, the configuration of the present invention will be described in detail.

<Quantum Dot>

In the present invention, quantum dots may be self-luminous by a light source and used to generate light in the visible and infrared regions. Quantum dots are materials with a crystal structure of several nanometers, and may be composed of hundreds to thousands of atoms. Atoms form molecules, and molecules form an aggregate of small molecules called clusters to form nanoparticles. Generally, when these nanoparticles have semiconductor properties, they are called quantum dots. The quantum dot of the present invention is not particularly limited as long as it conforms to this concept. When an object becomes smaller than the nano size, a quantum confinement effect occurs, which is a phenomenon in which the energy band gap of the object increases. It emits energy corresponding to the gap and can emit light by itself.

The quantum dot according to the present invention is characterized in that it has a ligand layer on its surface, and the ligand layer includes a compound represented by Formula 1 below. Accordingly, the surface of the quantum dot is protected, and oxidation stability is improved, thereby preventing a decrease in quantum efficiency and improving reliability.

[Formula 1]

In Formula 1,

A may be a thiol group, an amino group, an imidazole group or a carboxyl group.

L may be a thiol group, an amino group, or a carboxyl group.

R may be a straight or branched trivalent hydrocarbon group having 1 to 20 carbon atoms.

X may be a direct bond, -OC(=O)-, -C(=O)O-, -C(=O)NH- or -HNC(=O)-.

Y is a linear or branched alkanediyl group having 1 to 20 carbon atoms; , , or can be

n may be an integer from 1 to 15.

m may be an integer from 1 to 10.

Z may be an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a photopolymerization reactive group having 2 to 20 carbon atoms. The photopolymerization reactive group may be an alkenyl group, an alkynyl group or an acrylate group.

However, in Formula 1, there is no case where A and L are both thiol groups. When A and L are thiol groups at the same time, the probability of forming a disulfide bond between ligands is high, and rather, there is a problem in that the dispersibility and optical properties of the quantum dots may be deteriorated.

In one embodiment of the present invention, the ligand layer may be characterized in that it includes at least one selected from compounds represented by Chemical Formulas 1-1 to 1-7.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

[Formula 1-7]

The compound represented by Chemical Formula 1 of the present invention, as an organic ligand, may play a role of stabilizing the quantum dot by being coordinated to the surface of the quantum dot. Conventionally prepared quantum dots generally have a ligand layer on the surface, and the ligand layer immediately after preparation is composed 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 and the like. In this case, compared to the quantum dots of the present invention including the compound represented by Formula 1 as a ligand layer, the surface protection effect may be lowered due to the non-coupling defect on the surface of the quantum dots due to the weaker bonding force between the ligand layer and the quantum dots. there is. In addition, oleic acid is well dispersed in unsaturated hydrocarbon solvents such as n-hexane, a highly volatile organic compound (VOC), and aromatic solvents such as chloroform and benzene, but has poor dispersibility in solvents such as PGMEA. .

The compound represented by Formula 1 included in the ligand layer of the quantum dot according to the present invention has two reactive sites that can act as anchors, which are positions that bind to the quantum dots, and can increase the reactivity with the quantum dots. When all positions are combined with the quantum dots, the stability of the quantum dots can be further improved.

In some embodiments, the quantum dot according to the present invention includes the compound represented by Formula 1 in the ligand layer, and 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 and the like.

The quantum dot is not particularly limited as long as it is a quantum dot particle capable of emitting light when stimulated by light or electricity. For example, II-VI group semiconductor compounds; Group III-V semiconductor compounds; Group IV-VI semiconductor compounds; Group IV elements or compounds containing them; And it may be selected from the group consisting of combinations thereof, which may be used alone or in combination of two or more.

For example, the II-VI group semiconductor compound is a binary element compound selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and a quaternary compound selected from the group consisting of mixtures thereof, but is not limited thereto.

The group III-V semiconductor compound is a binary element compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; A ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof; And it may be selected from the group consisting of 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. It is not limited.

The group IV-VI semiconductor compound is a binary element compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; And SnPbSSe, SnPbSeTe, SnPbSTe, and may be at least one selected from the group consisting of quaternary compounds selected from the group consisting of mixtures thereof, but is not limited thereto either.

Although not limited thereto, the group IV element or a compound containing the same may be an element selected from the group consisting of Si, Ge, and mixtures thereof; And it may be selected from the group consisting of a binary element compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

Quantum dots are homogeneous unitary structures; dual structures such as a core-shell structure and a gradient structure; Or it may be a mixed structure thereof, and in the present invention, quantum dots are not particularly limited as long as they can emit light when stimulated by light.

According to one embodiment, the quantum dot has a core-shell structure, and the core is a combination of two or more of In, P, Zn, Ga, Cd, Se, S, Te, Pb, Ag, Hg, N, As, and O. Including a compound consisting of, wherein the shell is one of In, P, Zn, Ga, Cd, Se, S, Te, Pb, Hg, N, As, O, Mn, and a compound consisting of a combination of two or more of Sr. may contain more than

Specifically, the core may include InP, InZnP, InGaP, CdSe, CdS, CdTe, ZnS, ZnSe, ZnTe, CdSeTe, CdZnS, CdSeS, PbSe, PbS, PbTe, AgInZnS, AgInGaS, HgS, HgSe, HgTe, GaN, GaP, It includes at least one selected from the group consisting of GaAs, InGaN InAs, and ZnO, and the shell is ZnS, ZnSe, ZnTe, ZnO, CdS, CdSe, CdTe, CdO, InP, InS, GaP, GaN, GaO, GaS, It may include one or more selected from the group consisting of InZnP, InGaP, InGaN, InZnSCdSe, PbS, TiO, SrSe, and HgSe, and preferably, InP/ZnS, InP/ZnSe, InP/GaP/ZnS, InP/ It may include one or more selected from the group consisting of ZnSe/ZnS, InP/ZnSeTe/ZnS, and InP/MnSe/ZnS, but is not limited thereto.

In general, quantum dots may be prepared by a wet chemical process, a metal organic chemical vapor deposition (MOCVD) process, or a molecular beam epitaxy (MBE) process.

Quantum dots according to the present invention can be synthesized by a wet chemical process.

The wet chemical process is a method of growing particles by putting a precursor material in an organic solvent. When the crystal grows, the organic solvent is naturally coordinated to the surface of the quantum dot crystal and acts as a dispersant to control the growth of the crystal. The size growth of quantum dot particles can be controlled through a process that is easier and cheaper than vapor deposition methods such as molecular beam epitaxy.

When manufacturing quantum dots by a wet chemical process, organic ligands are used to prevent aggregation of quantum dots and to control the particle size of quantum dots at the nano level. As such an organic ligand, oleic acid may be generally used.

In one embodiment of the present invention, the oleic acid used in the manufacturing process of the quantum dots is replaced by the ligand exchange method with the compound represented by Formula 1.

In the ligand exchange, an organic ligand to be exchanged, that is, a compound represented by Formula 1 is added to a dispersion containing quantum dots having an original organic ligand, that is, oleic acid, and stirred at room temperature to 200° C. for 30 minutes to 3 hours. It can be carried out by obtaining a quantum dot to which the compound represented by Formula 1 is bonded. If necessary, a process of separating and purifying the quantum dots to which the compound of Formula 1 is bound may be additionally performed.

As described above, the quantum dot according to an embodiment of the present invention can be produced by an organic ligand exchange method under a simple stirring process at room temperature, and thus has the advantage of being mass-produced.

In addition, the quantum dot according to an embodiment of the present invention can maintain a quantum efficiency of about 90% or more compared to the initial quantum efficiency even after 15 days, so that it can be stably stored for a long period of time and commercialized for various purposes.

<Quantum dot dispersion>

The quantum dot dispersion according to an embodiment of the present invention is characterized in that it includes at least one of the above-described quantum dots, a photopolymerizable compound, and a solvent.

quantum dot

The quantum dot dispersion according to an embodiment of the present invention is characterized by including the above-described quantum dots. Description of the quantum dot is the same as that of the above-described <quantum dot>.

The quantum dots may be included in an amount of 10 to 90% by weight, preferably 20 to 80% by weight, and more preferably 30 to 70% by weight, based on the total weight of the quantum dot dispersion. When the quantum dots are included within the above range, the luminous efficiency is excellent, and the reliability of the light conversion coating layer prepared using the quantum dots is excellent. When the quantum dots are included within the above range, the dispersibility of the quantum dots is good, coating or jetting properties are excellent, and optical properties and reliability are excellent.

photopolymerizable compound

The photopolymerizable compound serves to improve the dispersibility of quantum dots.

The photopolymerizable compound may include monofunctional monomers, bifunctional monomers, and other multifunctional monomers, and preferably, bifunctional or higher functional monomers may be 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, and 2-hydroxyethyl acrylate. A rate etc. are mentioned.

The type of the bifunctional monomer is not particularly limited, and examples thereof include 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, ethylene glycol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, bis(acryloyloxyethyl) ether of bisphenol A, 3-methylpentanediol di(meth)acrylate, etc. are mentioned.

The type of the multifunctional monomer is not particularly limited, and examples thereof include trimethylolpropane tri(meth)acrylate, oxylated trimethylolpropane tri(meth)acrylate, and propoxylated trimethylolpropane tri(meth)acrylate. 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.

Among these, in terms of volatility, viscosity and jetting properties, the photopolymerizable compound is 2-hydroxyethyl acrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, ethylene The group consisting of glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate and tripropylene glycol di(meth)acrylate It may be more preferable to include one or more selected from

When the quantum dot dispersion according to the present invention includes the photopolymerizable compound, the content of the photopolymerizable compound may be 10 to 90% by weight, preferably 20 to 80% by weight, based on the total weight of the quantum dot dispersion. Preferably it may be included in 30 to 70% by weight. When the photopolymerizable compound is included within the above-described range, it is preferable because the dispersibility of the quantum dots is good, so that the coating or jetting properties are excellent, and the optical properties and reliability are excellent.

In the present invention, the description of the photopolymerizable compound is equally applied to the photopolymerizable compound included in the light conversion curable composition to be described later.

solvent

As long as the solvent is effective in dissolving other components included in the quantum dot dispersion, solvents commonly used in the art may be used without particular limitation. The solvent may be selected from among ethers, acetates, aromatic hydrocarbons, ketones, alcohols, esters, and amides as specific examples, but is not limited thereto.

Specifically, the ether solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether;

propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether;

diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; etc. can be mentioned.

The acetate solvents are specifically, alkylene glycol alkyl ether acetates such as methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate;

alkoxyalkyl acetates such as methoxybutyl acetate, methoxypentyl acetate, and n-pentyl acetate; etc. can be mentioned.

Specific examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, mesitylene, and the like.

Specific examples of the ketone solvent include methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone.

Specifically, the alcohol solvent includes ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, glycerin, and the like.

Specifically, the ester solvents include cyclic esters such as γ-butyrolactone; Ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, etc. are mentioned.

Specific examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

These solvents can be used individually or in mixture of 2 or more types, respectively.

When the quantum dot dispersion according to the present invention includes the solvent, the content of the solvent may be 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 90% by weight, based on the total weight of the quantum dot dispersion. 70% by weight. When the solvent is included within the above-described range, it is preferable because the dispersibility of the quantum dots is good, so that the coating or jetting properties are excellent, and the optical properties and reliability are excellent.

In the present invention, the description of the solvent is equally applied to the solvent included in the light conversion curable composition to be described later.

<Photoconversion Curable Composition>

Photoconversion curability according to an embodiment of the present invention The composition includes the above-described quantum dots, and may further include at least one component known in the art, such as a scattering particle, a photopolymerizable compound, a photopolymerization initiator, an antioxidant, and a solvent, as necessary. The description of the solvent is the same as that of <Quantum Dot Dispersion>.

Photoconversion curability according to an embodiment of the present invention The composition may be a solvent-free type that does not contain a solvent in terms of continuous processability. Photoconversion curing properties of this solvent-free type The composition has high dispersibility and viscosity stability, so it can be suitably used in a continuous process according to an inkjet method.

Photoconversion curability of the present invention A method for preparing the composition is not particularly limited, and methods known in the art may be used.

quantum dot

Photoconversion curability according to an embodiment of the present invention The composition is characterized in that it includes the quantum dots described above. In addition, in terms of improving dispersibility, a light conversion curable composition may be prepared by first preparing a quantum dot dispersion and then mixing it with the other components. The description of the quantum dots and the quantum dot dispersion is the same as that of the above-described <quantum dots> and <quantum dot dispersion>.

The content of the quantum dots is the photoconversion curability Based on the total weight of the solid content of the composition, it may be 1 to 60% by weight, preferably 5 to 55% by weight, and more preferably 10 to 50% by weight. A photoconversion curable composition containing the quantum dots within the above content range is preferable because it can have increased luminous efficiency and improved color reproducibility.

scattering particles

The scattering particles may use a conventional inorganic material, and preferably may include a metal oxide having an average particle diameter of 30 to 1000 nm.

The metal oxides include 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, It may be an oxide containing at least one metal selected from the group consisting of Ce, Ta, In, and combinations thereof, but is not limited thereto.

Specifically, 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 It may be one or more selected from the group consisting of combinations thereof, and preferably includes TiO ₂ in terms of scattering effect. If necessary, a material surface-treated with a compound having an unsaturated bond such as acrylate may also be used.

When the quantum dot light conversion composition according to the present invention includes the scattering particles, it is preferable that the overall light efficiency in the color filter can be increased by increasing the path of light spontaneously emitted from the quantum dots through the scattering particles.

Preferably, the scattering particles may have an average particle diameter of 30 to 1000 nm, preferably used in the range of 100 to 500 nm. At this time, if the particle size is too small, sufficient scattering effect of the light emitted from the quantum dots cannot be expected, and on the other hand, if it is too large, it sinks in the composition or the surface of the self-luminous layer of uniform quality cannot be obtained. and use it

When the light-conversion curable composition according to the present invention includes scattering particles, the content of the scattering particles determines the light-conversion curable composition. Based on the total weight of the solid content of the composition, it may be 0.5 to 35% by weight, preferably 0.5 to 15% by weight, more preferably 3 to 10% by weight. When the scattering particles are included within the above content range, excellent luminous efficiency and light retention are exhibited, surface hardness is excellent, there is no cracking, diffusivity and sensitivity are good, as well as pattern stability, developing speed, solvent resistance and outgassing. It is preferable because it can provide a light conversion curable composition having a reducing effect.

photopolymerizable compound

The photopolymerizable compound may include monofunctional monomers, bifunctional monomers, and other multifunctional monomers, and preferably, bifunctional or higher functional monomers may be 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, and 2-hydroxyethyl acrylate. A rate etc. are mentioned.

The type of the bifunctional monomer is not particularly limited, and examples thereof include 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, ethylene glycol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, bis(acryloyloxyethyl) ether of bisphenol A, 3-methylpentanediol di(meth)acrylate, etc. are mentioned.

The type of the multifunctional monomer is not particularly limited, and examples thereof include trimethylolpropane tri(meth)acrylate, oxylated trimethylolpropane tri(meth)acrylate, and propoxylated trimethylolpropane tri(meth)acrylate. 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.

Among them, 2-hydroxyethyl acrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, ethylene glycol di(meth)acrylate in terms of volatility, viscosity, and jetting properties One selected from the group consisting of acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate It may be more desirable to include the above.

When the light conversion curable composition according to the present invention includes a photopolymerizable compound, the content of the photopolymerizable compound is 20 to 80% by weight, preferably 30 to 70% by weight, based on the total solid weight of the light conversion curable composition. can When the photopolymerizable compound is included within the above content range, photosensitivity is not lowered, and strength or smoothness of the pixel portion may be improved.

photopolymerization initiator

The photopolymerization initiator is a compound for initiating the polymerization of the photopolymerizable compound described above, and is not particularly limited in the present invention, but in terms of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc., acetophenone-based compounds and benzophenone-based compounds , It is preferable to use at least one compound selected from the group consisting of triazine-based compounds, biimidazole-based compounds, oxime-based compounds, acylphosphine-based compounds, and thioxanthone-based compounds.

As an acetophenone compound, for example, diethoxy acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 2-hydroxy-1-[4-(2 -Hydroxyethoxy)phenyl]-2-methylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1- one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl[4-(1-methylvinyl)phenyl]propan-1- oligomers of one and the like, preferably 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one and the like.

As a benzophenone type compound, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether etc. are mentioned, for example. Examples of the benzophenone compound include benzophenone, o-benzoylmethylbenzoate, 4-phenylzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3',4,4'-tetra( t-butyl peroxycarbonyl) benzophenone, 2,4,6-trimethyl benzophenone, etc. are mentioned. Examples of the thioxanthone-based compound include 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro- 4-propoxy city oxanthone etc. are mentioned.

Examples of the triazine compound include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine and 2,4-bis(trichloromethyl) -6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-tri Azine, 2,4-bis (trichloromethyl) -6- [2- (5-methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl )-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino- 2-methylphenyl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4dimethoxyphenyl)ethenyl]-1,3,5 - Triazine etc. are mentioned.

Examples of the biimidazole-based compound include 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2 '-biimidazole, 2,2'-bis(2-bromophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole , 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl) -4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5' -Tetraphenyl-1,2'-biimidazole, 2,2'-bis(2-bromophenyl)-4,4,5,5'-tetraphenyl-1,2'-biimidazole, 2, 2'-bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6- tribromophenyl) -4,4',5,5'-tetraphenyl-1,2'-biimidazole; and the like.

The oxime compound is, for example, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, 1-(4-methylsulfanylphenyl)butane-1 ,2-butane-2-oxime-O-acetate, 1-(4-methylsulfanylphenyl)butan-1-one oxime-O-acetate, hydroxyimino(4-methylsulfanylphenyl)acetic acid ethyl ester-O -Acetate, hydroxyimino(4-methylsulfanylphenyl)acetic acid ethyl ester-O-benzoate, and the like, and commercial products such as Irgacure OXE-01 and OXE-02 from BASF are representative.

Acylphosphine compounds, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2 ,6-dichlorobenzoyldiphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6 -Dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2,4,6-trimethylbenzoylphenylphosphinic acid ethyl ester, 2,4 , 6-trimethylbenzoyl phenylphosphinic acid phenyl ester, etc. are mentioned.

Examples of the thioxanthone-based compound include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and the like. .

When the light conversion curable composition according to the present invention includes a photopolymerization initiator, the content of the photopolymerization initiator may be 0.2 to 15% by weight, preferably 0.5 to 10% by weight, based on the total solid weight of the light conversion curable composition. . When the photopolymerization initiator is included within the above content range, the photoconversion curable composition is highly sensitive, and thus has an advantage in that the strength of the pixel portion formed using the composition and the smoothness of the surface of the pixel portion are good.

antioxidant

The antioxidant may include at least one selected from phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants, and may preferably include at least one selected from phosphorus-based antioxidants and sulfur-based antioxidants.

As the phosphorus antioxidant, for example, tris (2,4-di-tert-butylphenyl) phosphite (Songnox 1680), tris (nonylphenyl) ) phosphite (Tris (nonylphenyl) phosphite, TNPP), di- (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (Di- (2,4-dit-butylphenyl) pentaerythritol diphosphite), etc. More than one can be selected and used.

As the phenolic antioxidant, for example, 2,6-di-tert-butyl-4-methyl-phenol (2,6-di-tert-butyl-4-methylphenol, BHT), thiodiethylene bis [2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (thiodiethylenebis[2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, Songnox 1035), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Songox 1076 ), tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane (tetrakis [methylene-3- (3,5-di-tert-butyl- 4-hydroxyphenyl) propionate] methane, Songox 1010), etc. may be used by selecting one or more types.

Examples of the sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimilstil-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate. It may be used by selecting one or more types from odipropionate, pentaerythritol tetrakis (3-laurylthiopropionate), and the like.

In addition, commercially available products of the antioxidant include IRGANOX 1035, IRGANOX 1081, IRGANOX 1425, IRGANOX 1726 (above, manufactured by BASF), Sumilizer GP (manufactured by Sumitomo Chemical), 135A, AO-40 (above, manufactured by Adeka) etc. can be mentioned.

The antioxidants exemplified above may be used alone or in combination of two or more.

When the light conversion curable composition according to the present invention includes an antioxidant, the content of the antioxidant may be 0.1 to 25% by weight, preferably 0.1 to 10% by weight, based on the total solid weight of the light conversion curable composition. there is. When the antioxidant is included within the above content range, it is preferable because flatness, adhesion, and the like of the light conversion ink curable composition can be improved.

The light-conversion curable composition prepared in this way can be preferably used for the manufacture of a color filter, a cured film such as a light-conversion laminated base material, and an image display device including the same.

<cured film>

The present invention provides a cured film formed using the light conversion curable composition, and the cured film may be a color filter or a light conversion laminated base material.

color filter

A pattern formation method for forming the color filter of the present invention may use a method known in the art.

For one embodiment, the pattern forming method,

a) applying a quantum dot curable composition to a substrate;

b) a prebake step;

c) curing the exposed area by applying actinic light to a photomask on the obtained film;

d) performing a developing process of dissolving the unexposed portion using an aqueous alkali solution; and

e) drying and post-baking; may be included.

The substrate may be a glass substrate or a polymer substrate, but is not limited thereto. As the glass substrate, soda lime glass, glass containing barium or strontium, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass or quartz can be preferably used. Further, examples of the polymer substrate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone substrates.

At this time, the coating may be performed by a known wet coating method using a coating device such as a roll coater, a spin coater, a slit and spin coater, a slit coater (sometimes referred to as a die coater), or an inkjet to obtain a desired thickness. .

Prebaking is performed by heating with an oven, hot plate or the like. At this time, the heating temperature and heating time in the prebake are appropriately selected according to the solvent used, and may be performed for 1 to 30 minutes at a temperature of 80 to 150 ° C, for example.

In addition, the exposure performed after the prebaking is performed by an exposure machine to expose through a photomask, thereby sensitizing only the portion corresponding to the pattern. At this time, as the light to be irradiated, for example, visible light, ultraviolet rays, X-rays, electron beams, and the like can be used.

The development step of dissolving the unexposed portion using an alkaline aqueous solution after exposure is performed for the purpose of removing the photosensitive resin composition of the unremoved portion of the unexposed portion, and a desired pattern is formed by this development. As a developing solution suitable for development using this aqueous alkali solution, for example, an aqueous solution of a carbonate of an alkali metal or an alkaline earth metal can be used. In particular, using an aqueous alkali solution containing 1 to 3% by weight of a carbonate such as sodium carbonate, potassium carbonate, or lithium carbonate at a temperature of 10 to 50° C., preferably 20 to 40° C., using a developing device or an ultrasonic cleaner. can be done by

The post-bake is performed to increase the adhesion between the patterned film and the substrate, and may be performed by heat treatment at 80 to 250° C. for 10 to 120 minutes, for example. Post-baking, like pre-baking, can be performed using an oven, hot plate, or the like.

Photoconversion layered substrate

The light conversion laminated base material according to the present invention includes a cured product of a light conversion curable composition. The light-converting laminated substrate includes a light-conversion curable composition that can be coated on a glass substrate, so that a solvent that is not harmful to the human body can be used, thereby improving worker safety and product productivity.

The light conversion layered substrate may be silicon (Si), silicon oxide (SiOx) or a polymer substrate, and the polymer substrate may be polyethersulfone (PES) or polycarbonate (PC).

The light conversion laminated base material may be formed by applying the light conversion curable composition and thermally curing or photocuring.

<Image display device>

An image display device according to the present invention includes the above-described cured film, that is, a color filter or a light conversion laminated base material. The image display device is specifically, a liquid crystal display (liquid crystal display device; LCD), an organic EL display (organic EL display device), a liquid crystal projector, a display device for game machines, a display device for portable terminals such as mobile phones, and a display for digital cameras. device, a display device such as a display device for car navigation, and the like, and a color display device is particularly suitable.

The image display device includes configurations known to those skilled in the art, except for having the color filter or the light conversion laminated base material, and may further include, that is, the present invention relates to a color filter or a light conversion layer. It includes an image display device to which the conversion laminated base material can be applied.

An image display device including a color filter according to the present invention may have excellent properties in terms of light conversion efficiency, heat resistance, viscosity stability, and coating film hardness.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to explain the present invention in more detail, and the scope of the present invention is not limited by the following examples.

<Example>

Synthesis Example 1: Synthesis of InP/ZnSe/ZnS core-shell quantum dots

Indium acetate (Indium acetate) 0.4mmol (0.058g), palmitic acid (palmitic acid) (palmitic acid) (palmitic acid) 0.6mmol (0.15g) and 1-octadecene (octadecene) 20mL was put into the reactor and heated to 120 ℃ under vacuum. After 1 hour, the atmosphere in the reactor was changed to 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 quickly injected and reacted for 0.5 minutes.

2.4 mmol (0.448 g) of zinc acetate, 4.8 mmol of oleic acid and 20 mL of trioctylamine were then charged into the reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was changed to nitrogen, and the temperature of the reactor was raised to 280°C. 2 mL of the previously synthesized InP core solution was added, followed by 4.8 mmol of selenium (Se/TOP) in trioctylphosphine, 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 dried under reduced pressure to form an InP/ZnSe core-shell.

Then, 2.4 mmol (0.448 g) of zinc acetate, 4.8 mmol of oleic acid and 20 mL of trioctylamine were charged into the reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was changed to nitrogen, and the temperature of the reactor was raised to 280°C. 2 mL of the previously synthesized InP core solution was added, followed by 4.8 mmol of sulfur (S/TOP) in trioctylphosphine, and 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 dried under reduced pressure.

The obtained quantum dot powder was dispersed in chloroform so that the solid content was 10% to obtain a quantum dot solution having an InP/ZnSe/ZnS core-shell structure. The maximum emission wavelength was 535 nm.

Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-4: Preparation of quantum dots and quantum dot dispersions

Example 1-1: Ligand substitution reaction 1 (A-1)

5mL of the quantum dot solution obtained in Synthesis Example 1 was placed in a centrifuge tube and 20mL of ethanol was added to precipitate it. Through centrifugation, the supernatant was discarded, and 3 mL of chloroform was added to the precipitate to disperse the quantum dots, and then 1.0 g of a compound represented by Formula 1-1 was added and reacted for one hour while heating at 60 ° C. under a nitrogen atmosphere.

Next, 25mL of n-hexane was added to the reaction mixture to precipitate the quantum dots, and centrifugation was performed to separate the precipitates, followed by drying in a 60 ° C. reduced pressure oven for 3 hours to obtain ligand-substituted quantum dot powder (A-1). 1,6-Hexanediol diacrylate was added to the obtained quantum dot powder so that the solid content was 50%, and then stirred to prepare a quantum dot dispersion. The maximum emission wavelength was 535 nm.

[Formula 1-1]

Example 1-2. Ligand substitution reaction 2 (A-2)

Except for using the compound represented by Formula 1-2 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 536 nm.

[Formula 1-2]

Example 1-3. Ligand substitution reaction 3 (A-3)

Except for using the compound represented by Formula 1-3 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 536 nm.

[Formula 1-3]

Example 1-4. Ligand substitution reaction 4 (A-4)

Except for using the compound represented by Formula 1-4 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 535 nm.

[Formula 1-4]

Example 1-5. Ligand substitution reaction 5 (A-5)

Except for using the compound represented by Formula 1-5 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 535 nm.

[Formula 1-5]

Example 1-6. Ligand substitution reaction 6 (A-6)

Except for using the compound represented by Formula 1-6 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 535 nm.

[Formula 1-6]

Example 1-7. Ligand substitution reaction 7 (A-7)

Example 1-1 was performed in the same manner as in Example 1-1, except that a compound represented by Formula 1-7 was used instead of the ligand used in Example 1-1. The maximum emission wavelength was 536 nm.

[Formula 1-7]

Comparative Example 1-1: Quantum dot dispersion without ligand exchange reaction (A-8)

5mL of the quantum dot solution obtained in Synthesis Example 1 was placed in a centrifuge tube, and 20mL of ethanol was added to precipitate the quantum dots. The supernatant was discarded, and the precipitate was separated and dried in an oven at 60 °C for 3 hours. 1,6-Hexanediol diacrylate was added to the obtained quantum dot powder so that the solid content was 50%, and then stirred to prepare a quantum dot dispersion. The maximum emission wavelength was 536 nm.

Comparative Example 1-2: Ligand substitution reaction 8 (A-9)

Except for using the following Chemical Formula 2-1 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 535 nm.

[Formula 2-1]

Comparative Example 1-3: Ligand Substitution Reaction 9 (A-10)

Except for using the following Chemical Formula 2-2 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 536 nm.

[Formula 2-2]

Comparative Example 1-4: Ligand Substitution Reaction 10 (A-11)

Except for using the following Chemical Formula 2-3 instead of the ligand used in Example 1-1, the procedure was performed in the same manner as in Example 1-1. The maximum emission wavelength was 535 nm.

[Formula 2-3]

Examples 2-1 to 2-11 and Comparative Examples 2-1 to 2-5: Preparation of light conversion curable composition

According to the ingredients and contents shown in Table 1 below, a light conversion curable composition was prepared.

(weight%) Example comparative example 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 2-11 2-1 2-2 2-3 2-4 quantum dot
dispersion A-1 50 - - - - - - 50 50 50 50 - - - - A-2 - 50 - - - - - - - - - - - - - A-3 - - 50 - - - - - - - - - - - - A-4 - - - 50 - - - - - - - - - - - A-5 - - - - 50 - - - - - - - - - - A-6 - - - - - 50 - - - - - - - - - A-7 - - - - - - 50 - - - - - - - - A-8 - - - - - - - - - - - 50 - - - A-9 - - - - - - - - - - - - 50 - - A-10 - - - - - - - - - - - - - 50 - A-11 - - - - - - - - - - - - - - 50 photopolymerization
compound B-1 39 39 39 39 39 39 39 39 39 39 44 39 39 39 39 photopolymerization initiator C-1 One One One One One One One One One One One One One One One antioxidant D-1 5 5 5 5 5 5 5 - - - - 5 5 5 5 D-2 - - - - - - - 5 - - - - - - - D-3 - - - - - - - - 5 - - - - - - D-4 - - - - - - - - - 5 - - - - - scattering particles E-1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

- A-1 to 7: Quantum dot dispersions according to Examples 1-1 to 1-7

- A-8 to 11: Quantum dot dispersions according to Comparative Examples 1-1 to 1-4

- B-1: 1,6-Hexanediol diacrylate (Aldrich)

- C-1: Irgacure OXE-01 (BASF)

- D-1: Sumilizer GP (Sumitomo Chemical; MW 661)

- D-2: Irganox 1035 (BASF)

- D-3: 135A (Adeka Company)

- D-4: AO-40 (Adeka Company)

- E-1: TiO ₂ (Hunzmann, TR-88, particle diameter 220nm)

Experimental Example

(1) Preparation of light conversion coating layer

Each of the photoconversion curable compositions prepared in Examples 2-1 to 2-11 and Comparative Examples 2-1 to 2-5 was coated on a 5cm×5cm glass substrate by an inkjet method, and then 395nm Blue LED light was applied under nitrogen conditions. After irradiation with 4000 mJ/cm 2 using, a light conversion coating layer was prepared by heating in a heating oven at 180° C. for 30 minutes. The film thickness of the prepared light conversion coating layer was measured using a film thickness meter (Dektak 6M, Vecco Co.), and the following evaluation was performed on a 10 μm coating film.

(2) Evaluation of light conversion efficiency

After placing the prepared light conversion coating layer on top of a blue light source (XLamp XR-E LED, Royal blue 450, Cree Co.), a luminance meter (CAS140CT Spectrometer, Instrument systems Co.) and using Equation 1 below The light conversion efficiency was measured and calculated, and the results are shown in Table 2 below. As the light conversion efficiency (%) is higher, excellent luminance can be obtained.

[Equation 1]

(3) Heat resistance evaluation

When preparing the light conversion coating layer, the light conversion efficiency was measured before and after baking at 180 ° C. for 30 minutes, and the light retention after baking was calculated by Equation 2 below to evaluate heat resistance. The results are shown in Table 2 below. It can be determined that the higher the photoretention rate, the better the heat resistance.

[Equation 2]

Light retention (%) = (180°C, 30 minutes, luminous efficiency after baking) / (luminous efficiency before baking) × 100

(4) Evaluation of viscosity stability

With respect to the light conversion curable composition prepared above, using an R-type viscometer (VISCOMETER MODELRE120L SYSTEM, manufactured by Toki Sangyo Co., Ltd.), the initial viscosity under conditions of rotation speed of 20 rpm and temperature of 25 ° C. or 40 ° C. and after storage for 1 month Viscosity was measured. The viscosity change rate (%) for the initial viscosity was calculated, and the viscosity stability was evaluated according to the following evaluation criteria, and the results are listed in Table 2.

<Evaluation Criteria>

◎: Viscosity change rate 105% or less

○: viscosity change rate greater than 105% to 110% or less

△: viscosity change rate greater than 110% to 120% or less

×: Viscosity change rate exceeding 120%

(5) Evaluation of coating hardness

The degree of curing of the prepared light conversion coating layer was measured at a high temperature of 150° C. using a durometer (HM500; Fischer Co.), and the coating hardness was evaluated according to the following evaluation criteria. The results are shown in Table 2 below.

<Criteria for evaluation of coating hardness>

○: surface hardness of 50 mN/mm ² or more

△: surface hardness of 30 mN/mm ² or more and less than 50 mN/mm ²

×: surface hardness less than 30 mN/mm ²

Evaluation results light conversion efficiency Mineral retention rate (after/before baking) Viscosity stability (25℃) Viscosity stability (40℃) coating hardness Example 2-1 33% 93% ◎ ○ ○ Example 2-2 30% 93% ◎ ○ ○ Example 2-3 31% 92% ◎ ○ ○ Example 2-4 32% 94% ◎ △ ○ Example 2-5 32% 94% ◎ ○ ○ Example 2-6 31% 92% ◎ △ ○ Examples 2-7 31% 93% ◎ ○ ○ Example 2-8 32% 91% ◎ ○ ○ Examples 2-9 32% 92% ◎ ○ ○ Examples 2-10 31% 90% ○ △ ○ Examples 2-11 30% 89% ○ △ △ Comparative Example 2-1 25% 82% △ × × Comparative Example 2-2 28% 85% × × △ Comparative Example 2-3 27% 83% △ × △ Comparative Example 2-4 30% 87% ○ × △ Comparative Example 2-5 24% 81% × × ×

Referring to Table 2, the photoconversion curable compositions of Examples 2-1 to 2-11 including the ligand layer represented by Formula 1 have a photoconversion efficiency of 30% or more and an optical retention rate of 89% or more after baking. , The viscosity change rate at 25 ° C. is 110% or less, the viscosity change rate at 40 ° C. is 120% or less, and the hardness of the coating film surface is 30 mN / mm ² or more, while not including the ligand layer represented by the formula (1). In the light conversion curable compositions of Examples 2-1 to 2-5, it can be confirmed that light conversion efficiency, light retention after baking, viscosity change rate, and/or hardness of the surface of the coating film are significantly reduced.

In addition, the photoconversion curable compositions of Examples 2-1 to 2-10 containing an antioxidant show superior coating film hardness, and in particular, Examples 2-1 to 2-9 containing a phosphorus-based antioxidant or a sulfur-based antioxidant. It can be seen that the light conversion curable composition of shows better viscosity stability (25 ° C and 40 ° C).

Therefore, it was confirmed that the photoconversion curable composition including quantum dots including the ligand layer represented by Formula 1 was superior in photoconversion efficiency, heat resistance, viscosity stability and coating hardness compared to the photoconversion curable composition not containing the quantum dots.

Claims (14)

As a quantum dot having a ligand layer on the surface,
Quantum dots, wherein the ligand layer comprises a compound represented by Formula 1 below.
[Formula 1]

(In Formula 1 above,
A is a thiol group, an amino group, an imidazole group or a carboxyl group;
L is a thiol group, an amino group, or a carboxyl group;
R is a straight or branched trivalent hydrocarbon group having 1 to 20 carbon atoms,
X is a direct bond, -OC(=O)-, -C(=O)O-, -C(=O)NH- or -HNC(=O)-;
Y is a linear or branched alkanediyl group having 1 to 20 carbon atoms; , , or ego,
n is an integer from 1 to 15;
m is an integer from 1 to 10;
Z is an alkyl group of 1 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aromatic hydrocarbon group of 6 to 20 carbon atoms, or a photopolymerization reactive group of 2 to 20 carbon atoms.
However, there is no case where A and L are thiol groups at the same time.) The method according to claim 1, wherein the photopolymerization reactive group is an alkenyl group, an alkynyl group or an acrylate group, quantum dots The method according to claim 1, wherein the quantum dot has a core-shell structure including a core and a shell covering the core,
The core includes a compound consisting of a combination of two or more of In, P, Zn, Ga, Cd, Se, S, Te, Pb, Ag, Hg, N, As, and O,
Characterized in that the shell includes one or more of compounds consisting of a combination of two or more of In, P, Zn, Ga, Cd, Se, S, Te, Pb, Hg, N, As, O, Mn, and Sr. Do, quantum dots. A quantum dot dispersion comprising the quantum dot according to any one of claims 1 to 3, and at least one of a photopolymerizable compound and a solvent. The method according to claim 4, wherein the photopolymerizable compound is 2-hydroxyethyl acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate At least one member selected from the group consisting of acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate A quantum dot dispersion containing a. A light conversion curable composition comprising the quantum dot dispersion according to claim 4 . The light conversion curable composition according to claim 6, further comprising at least one selected from scattering particles, photopolymerizable compounds, photopolymerizable initiators, and antioxidants. The method according to claim 7, wherein the photopolymerizable compound is 2-hydroxyethyl acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate At least one member selected from the group consisting of acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate Containing, a light conversion curable composition. The light conversion curable composition according to claim 7, wherein the scattering particles include TiO ₂ . The light conversion curable composition of claim 7, wherein the antioxidant comprises at least one selected from phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants. The light conversion curable composition according to claim 10, wherein the antioxidant includes at least one selected from phosphorus-based antioxidants and sulfur-based antioxidants. A cured film formed by using the light conversion curable composition according to claim 6. The method according to claim 12, wherein the cured film is a color filter or light conversion laminated base material, a cured film. An image display device comprising the cured film according to claim 12 .