KR102625548B1 - Quantum dots, curable composition comprising the same, and curable pattern and image display formed from the composition - Google Patents

Abstract

Quantum dot particles of embodiments of the present invention include a ligand having a carboxyl group, an ester group, and one ether group in the main chain. As the quantum dot particles include the ligand, a curable composition with excellent dispersibility and optical properties can be provided. Additionally, a cured pattern with excellent light efficiency and durability and an image display device including the same can be provided.

Description

QUANTUM DOTS, CURABLE COMPOSITION COMPRISING THE SAME, AND CURABLE PATTERN AND IMAGE DISPLAY FORMED FROM THE COMPOSITION}

The present invention relates to quantum dot particles, a curable composition containing the same, a cured pattern formed therefrom, and an image display device. More specifically, it relates to quantum dot particles containing a ligand, a curable composition containing the same, a cured pattern formed therefrom, and an image display device.

A color filter is a thin film-type optical component that extracts three colors, red, green, and blue, from white light and functions in tiny pixel units. The size of one pixel is about tens to hundreds of micrometers. The color filter is a black matrix layer formed in a predetermined pattern on a transparent substrate to block light at the boundary between each pixel, and a plurality of colors (typically red (R), green (G), and It has a structure in which pixel units in which the three primary colors (blue (B)) are arranged in a certain order are stacked one after another. In general, color filters can be manufactured by coating three or more colors on a transparent substrate using dyeing, electrodeposition, printing, or pigment dispersion methods. Recently, pigment dispersion methods using pigment-dispersed photosensitive resins are mainly used. there is.

According to the pigment dispersion method, which is one of the methods of implementing a color filter, first, a photosensitive resin composition containing a colorant, alkali-soluble resin, photopolymerization monomer, photopolymerization initiator, epoxy resin, solvent, and other additives is deposited on a transparent substrate provided with a black matrix. Coat on the substrate. Afterwards, a colored thin film can be formed by repeating a series of processes of exposing the pattern of the shape to be formed, removing the non-exposed area with a solvent and heat curing.

However, color reproduction is achieved by light emitted from a light source passing through a color filter, and in this process, part of the light is absorbed by the color filter, which may reduce light efficiency. Additionally, perfect color reproducibility may not be secured due to the characteristics of the pigment as a color filter.

Korean Patent Publication No. 10-2012-112188 discloses an example of a red coloring composition for a color filter and a color filter.

Korean Patent Publication No. 10-2012-112188

One object of the present invention is to provide quantum dot particles with excellent optical properties and dispersibility and a curable composition containing the same.

One object of the present invention is to provide a cured pattern and an image display device formed from the curable composition.

1. Quantum dot particles containing a ligand having a carboxyl group, an ester group, and one ether group in the main chain.

2. The quantum dot particle of 1 above, wherein the ligand includes a compound represented by the following formula (1):

[Formula 1]

(In Formula 1, R ₁ is a single bond or a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, R ₂ is a divalent aliphatic hydrocarbon group having 3 to 8 carbon atoms, and R ₃ is a replaceable aliphatic hydrocarbon group having 1 to 10 carbon atoms. It is a hydrocarbon group or a substituted aromatic hydrocarbon group having 6 to 12 carbon atoms).

3. The quantum dot particle of 1 above, wherein the ligand includes at least one selected from the group consisting of compounds represented by the following formulas 2-1 to 2-21.

4. The method of 1 above, wherein the quantum dot particles include at least one selected from the group consisting of a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, or a compound containing the same. particle.

5. The quantum dot particle of 1 above, wherein the quantum dot particle includes a core and a shell covering the core.

6. The quantum dot particle of 5 above, wherein the core contains indium (In) or phosphorus (P), and the shell contains zinc (Zn), selenium (Se), or sulfur (S).

7. The method of 6 above, wherein the shell includes a first shell layer covering the core and a second shell layer covering the first shell layer, the core includes InP or InZnP, and the first shell layer includes ZnSe or ZnSeS. A quantum dot particle comprising: wherein the second shell layer includes ZnS.

8. A curable composition comprising quantum dot particles containing a ligand having a carboxyl group, an ester group, and one ether group in the main chain.

9. The curable composition according to item 8 above, further comprising at least one of a binder resin, a polymerizable compound, a polymerization initiator, and a solvent.

10. A cured pattern formed from the curable composition according to 8 above.

11. An image display device comprising a curing pattern according to 10 above.

Quantum dot particles according to embodiments of the present invention include a ligand having a carboxyl group, an ether group, and an ester group, and thus can provide excellent dispersibility and solubility in polar solvents while providing improved optical properties.

In addition, the quantum dot particles according to embodiments of the present invention can provide a curable composition with excellent durability and reliability because it contains only one ether in the main chain.

In addition, a cured pattern with excellent light efficiency and durability and an image display device including the same can be formed using the curable composition according to embodiments of the present invention.

According to embodiments of the present invention, quantum dot particles containing a ligand having a carboxyl group, an ester group, and one ether group in the main chain are provided. As the ligand has a carboxyl group, an ester group, and an ether group in the main chain, the solubility and dispersibility of the quantum dot particles in polar solvents can be improved and optical properties can be excellent.

Additionally, a curable composition including the quantum dot particles, a cured pattern formed from the curable composition, and an image display device including the cured pattern are provided. The cured pattern may have excellent optical properties and durability as it includes the quantum dot particles.

Hereinafter, quantum dot particles according to embodiments of the present invention will be described in detail. If there are isomers of the compound or resin represented by the chemical formula used in this application, the compound or resin represented by the chemical formula means the representative chemical formula including the isomers.

Below, embodiments of the present invention will be described in detail.

<Quantum dot particles>

Quantum dot particles according to embodiments of the present invention may include a ligand having a carboxyl group, an ester group, and an ether group. For example, it may include quantum dot particles on which the ligand is disposed on the surface or whose surface is modified with the ligand.

Quantum dots can refer to nano-sized semiconductor materials. Specifically, atoms form molecules, and molecules form a collection of small molecules called clusters to form nanoparticles. When these nanoparticles have semiconductor properties, they are called quantum dots.

When the quantum dot particle receives energy from the outside and reaches an excited state, it emits energy (for example, light) according to the energy band gap of the quantum dot. Specifically, quantum dot particles are capable of photoluminescence, which emits light by light irradiation, or electroluminescence, which emits light by applying electric current, and are used as light-emitting materials in various fields such as display devices, energy devices, or bioluminescent devices. It is applicable as.

For example, quantum dot particles can be used in LCD (Liquid Crystal Diodes)-based displays using photoluminescent devices or QLED (Quantum dot Light Emitting Diodes)-based displays using electroluminescent devices.

The curable composition and cured pattern according to exemplary embodiments include such quantum dot particles and may emit light by themselves, for example, by light irradiation.

Quantum dot particles can control the energy band gap of quantum dots by controlling the size and/or composition of the nanocrystals. For example, as the size of a quantum dot particle decreases, it can have a wider energy band gap and the emission wavelength can decrease. Therefore, by adjusting the particle size and/or composition of the quantum dot particles, quantum dot particles that emit light of a desired wavelength can be implemented.

For example, the quantum dot particles may include blue quantum dots that emit blue light, green quantum dots that emit green light, or red quantum dots that emit red light. For example, in the case of the green quantum dots or red quantum dots, blue light can be irradiated and converted into green light or red light.

Additionally, in the case of a general image display device including a color filter, a portion of the light may be absorbed by the color filter in the process of implementing color by transmitting the irradiated white light through the color filter. Accordingly, light efficiency may decrease in the process of transmitting through the color filter.

When a color filter made of a curable composition containing quantum dot particles according to exemplary embodiments is included, the color filter self-lumines by light irradiated from a light source, thereby realizing superior light efficiency.

According to exemplary embodiments, the quantum dot particles may include a material that emits light when stimulated by light. For example, it may include group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements or compounds containing them, and mixtures thereof. These may be used alone or in combination of two or more.

The II-VI group compounds include binary compounds selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; a ternary compound selected from CdSeS, CdSeTe, CdSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and a tetraelement compound selected from CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.

The III-V group compounds include binary compounds selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; A ternary compound selected from GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof; and a tetraelement compound selected from GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof.

The Group IV-VI compounds include binary compounds selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; a ternary compound selected from SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and a quaternary element compound selected from SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

The Group IV element or a compound containing it is a compound of an element selected from Si, Ge, and mixtures thereof; and a binary compound selected from SiC, SiGe, and mixtures thereof.

According to exemplary embodiments, the quantum dot particles may have a homogeneous single structure, a core-shell structure, a gradient structure, or a mixture thereof.

In some embodiments, the quantum dot particles may have a core-shell structure consisting of a core and a shell covering the core. The core may be a part where light emission occurs. The shell can serve to improve the stability and efficiency of quantum dot particles by preventing oxidation of the core and reducing the trap energy level on the surface.

The materials that make up each core and shell may be made of the different compounds described above. For example, the core may be GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, InNP, InZnP, InNAs, InNSb, InPAs, InPSb GaInPAs, GaInPSb, InAlNP, InAlNAs, It may include one or more materials selected from the group consisting of InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. The shell may include one or more materials selected from the group consisting of ZnSe, ZnS, ZnTe, CdTe, PbS, TiO, SrSe, HgSe, ZnSe, ZnS, ZnSeS, and mixtures thereof. Preferably, the core may include In and P, and the shell may include Zn, Se and/or S.

In some embodiments, the shell may have a multi-layered shell structure including one or more shell layers. For example, the quantum dot particle may include a core, a first shell layer covering the core, and a second shell layer covering the first shell layer.

In some embodiments, adjacent core and shell layers in the multi-layer shell structure may have different compositions. For example, the core may include InP, and/or InZnP, the first shell layer may include ZnSe and/or ZnSeS, and the second shell layer may include ZnS.

In some embodiments, the quantum dot particles may be non-cadmium-based quantum dots that substantially do not contain cadmium (Cd). Accordingly, environmental or human health problems caused by cadmium can be prevented.

The ligand having the carboxyl group, ester group, and ether group may be disposed on the surface of the quantum dot particle. For example, the ligand may be a substituted or unsubstituted hydrocarbon having a carboxyl group at one end and an ester group and an ether group in the main chain.

The carboxyl group has strong affinity with the quantum dot particles and can chemically bind to the surface of the quantum dot particles. For example, the carboxyl group of the ligand may form a coordination bond with Zn included in the shell of the quantum dot particle. Accordingly, the ligand can stably passivate the quantum dot particles.

In general, the ligand used in quantum dots is composed of an aliphatic group with a high carbon content, so the quantum dot particles are mainly soluble only in non-polar solvents, and are soluble in polar organic solvents and water mainly used in the display manufacturing process. Dispersibility was not sufficiently implemented. Accordingly, for example, compatibility in image display device processes was poor and sufficient light efficiency was not provided.

As a ligand having a polar ether group and an ester group in the main chain according to exemplary embodiments is disposed on the surface of the quantum dot particle, the quantum dot particle may be polarized. Accordingly, the solubility and dispersibility of quantum dot particles in polar solvents may be excellent.

The term “main chain” used in this application refers to the portion consisting of the longest chain of atoms in the molecular structure of a ligand.

For example, the ligand may have an ester group positioned adjacent to the carboxyl group, and thus the exchange reaction of the ligand may be facilitated, allowing the ligand to stably passivate the quantum dot particles. In addition, as the surface of the quantum dot particles is modified with the ligand, decomposition of the ligand can be prevented even during high-temperature heat and exposure processes, and excellent binding force to the surface of the quantum dot particles can be achieved. Accordingly, excellent light efficiency of the quantum dot particles can be maintained even after the curing process.

For example, since the ligand contains only one ether in the main chain, the solubility of the quantum dot particles in polar solvents can be improved while preventing oxidation and damage of the quantum dot particles, thereby maintaining excellent light conversion characteristics.

If the ligand contains two or more ether groups in the main chain, the reliability and durability of the quantum dot particles under harsh conditions (eg, high temperature/high humidity) may be reduced. For example, since ether groups have relatively high moisture absorption, if the ligand contains multiple ether groups in the molecular structure, oxygen or moisture may easily penetrate into the quantum dot particles. Accordingly, the core and/or shell of the quantum dot particles may be oxidized, thereby deteriorating the optical properties.

Since the ligand included in the quantum dot particles according to exemplary embodiments has only one ether in the main chain, dispersibility in polar solvents can be improved while preventing oxidation/damage of the quantum dot particles by oxygen or moisture.

In some embodiments, the ligand may have a cyclic hydrocarbon or aromatic hydrocarbon at the end. For example, it may include a phenyl group or a benzyl group at the end. Cyclic hydrocarbons or aromatic hydrocarbons have a relatively bulky structure, so they can inhibit quantum dot particles from aggregating with each other. Additionally, oxygen or moisture permeability may be reduced due to steric hindrance at the end of the ligand. Therefore, the dispersibility and light efficiency of quantum dot particles may be excellent.

According to exemplary embodiments, the ligand may include a compound represented by Formula 1 below.

[Formula 1]

In Formula 1, R ₁ may be a single bond or a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ₂ may be a divalent aliphatic hydrocarbon group having 3 to 8 carbon atoms. R ₃ may be a monovalent aliphatic hydrocarbon group having 1 to 10 replaceable carbon atoms or an aromatic hydrocarbon group having 6 to 10 replaceable carbon atoms.

The monovalent or divalent aliphatic hydrocarbon group may be a straight-chain, branched-chain, or cyclic hydrocarbon group.

For example, the monovalent aliphatic hydrocarbon group may be an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, or cycloalkynyl group. For example, the divalent aliphatic hydrocarbon may be an alkylene group, alkenylene group, alkynylene group, cycloalkylene group, cycloalkenylene group, or cycloalkynylene group.

The aromatic hydrocarbon group may be an aryl group, an arylalkyl group, or an alkylaryl group.

For example, R ₁ is an alkylene group with 1 to 10 carbon atoms, an alkenylene group with 2 to 10 carbon atoms, an alkynylene group with 2 to 10 carbon atoms, a cycloalkylene group with 3 to 10 carbon atoms, and a cycloalkenyl group with 3 to 10 carbon atoms. It may be a lene group or a cycloalkynylene group having 3 to 10 carbon atoms.

For example, R ₂ is an alkylene group with 3 to 8 carbon atoms, an alkenylene group with 3 to 8 carbon atoms, an alkynylene group with 3 to 8 carbon atoms, a cycloalkylene group with 3 to 8 carbon atoms, and a cycloalkenyl group with 3 to 8 carbon atoms. It may be a lene group or a cycloalkynylene group having 3 to 8 carbon atoms.

For example, R ₃ is an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, an alkynyl group with 2 to 10 carbon atoms, a cycloalkyl group with 3 to 10 carbon atoms, a cycloalkenyl group with 3 to 10 carbon atoms, and a C3 to 10 carbon atom group. It may be a cycloalkynyl group of 10, an aryl group of 6 to 10 replaceable carbon atoms, an arylalkyl group of 7 to 10 replaceable carbon atoms, or an alkylaryl group of 7 to 10 replaceable carbon atoms. Preferably, it may be a benzyl group or a phenyl group.

The term "substituted" means that at least one of the hydrogen atoms of the aliphatic hydrocarbon or aromatic hydrocarbon is a halogen atom, a hetero atom, a hydroxy group, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a cyano group, or a nitro group. It means being substituted with at least one selected from the group consisting of a group and a thiol group.

As shown in Formula 1, the ligand has an ester group and one ether group in the main chain, thereby stably maintaining solubility and dispersibility in polar organic solvents and preventing oxidation of quantum dot particles. Accordingly, the chemical resistance, moisture resistance, and optical characteristics of the cured pattern can be improved.

In some embodiments, the ligand may include at least one selected from the group consisting of compounds represented by Formulas 2-1 to 2-21 below.

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-4]

[Formula 2-5]

[Formula 2-6]

[Formula 2-7]

[Formula 2-8]

[Formula 2-9]

[Formula 2-10]

[Formula 2-11]

[Formula 2-12]

[Formula 2-13]

[Formula 2-14]

[Formula 2-15]

[Formula 2-16]

[Formula 2-17]

[Formula 2-18]

[Formula 2-19]

[Formula 2-20]

[Formula 2-21]

In some embodiments, the ligand may be included in about 30 to 200% by weight based on the total weight of the quantum dot particles (eg, core and shell) excluding the ligand. If the content of the ligand is less than about 30% by weight, the dispersibility of the quantum dot particles in the polar solvent may not be sufficiently provided. When the content of the ligand exceeds about 200% by weight, the degree of curing and light efficiency of the cured pattern may decrease as the ligand is excessively disposed on the surface of the quantum dot particle. Preferably, the ligand may be included in about 50 to 150% by weight based on the total weight of the quantum dot particles excluding the ligand.

According to exemplary embodiments, the average particle diameter of the quantum dot particles may be about 5 to 12 nm. In some embodiments, when the quantum dot particles have a core-shell structure, the average particle diameter of the core may be about 2.5 to 5 nm, and the thickness of the shell may be about 2.5 to 7 nm. When the average particle diameter and thickness are within the above range, the dispersibility of the quantum dot particles is improved, and the desired color can be efficiently achieved by light irradiation.

In some embodiments, the quantum dot particles may be synthesized by a wet chemical process, metal organic chemical vapor deposition (MOCVD), or molecular beam epitaxy (MBE). You can. The wet chemical process is a method of growing particles by adding precursor materials to an organic solvent. When a crystal grows, the organic solvent is coordinated to the surface of the quantum dot crystal, acts as a dispersant, and regulates the growth of the crystal. Accordingly, the growth of crystals can be controlled through an easier and cheaper process than vapor deposition methods such as an organometallic chemical vapor deposition process or a molecular beam epitaxy process.

<Curable composition>

The curable composition according to embodiments of the present invention may include quantum dot particles according to exemplary embodiments, and may further include a binder resin, a solvent, a polymerizable compound, a polymerization initiator, and other additives.

As the quantum dot particles contain a ligand having a carboxyl group, an ester group, and an ether group, the dispersibility of the quantum dot particles in the curable composition is excellent, and a cured product in which the quantum dot particles are uniformly distributed can be provided.

In some embodiments, the content of the quantum dot particles may be about 1 to 30% by weight of the total solid weight of the curable composition. If the content of the quantum dot particles is less than 1% by weight, the luminous efficiency by the quantum dot particles may decrease. If the content of the quantum dot particles is more than 30% by weight, it may be difficult to form a cured pattern due to the relatively insufficient content of other compositions. Preferably, the quantum dot particles may be included in about 3 to 20% by weight of the total solid weight of the curable composition.

binder resin

The binder resin may include a thermosetting resin or an alkali-soluble resin. The binder resin may be a component that provides solubility to alkaline development used in the development process when forming a pattern.

In some embodiments, the binder resin may include an acrylic resin, a cardo-based resin, or an epoxy resin. These may be used alone or in combination of two or more. Preferably, it may be an acrylic resin and/or a cardo-based resin.

For example, acrylic resins include polybenzyl methacrylate, meth)acrylic acid/benzyl methacrylate copolymer, (meth)acrylic acid/benzyl methacrylate/styrene copolymer, (meth)acrylic acid/benzyl methacrylate/2- It may include hydroxyethyl methacrylate copolymer, (meth)acrylic acid/benzyl methacrylate/styrene/2-hydroxyethyl methacrylate copolymer, etc.

For example, the epoxy resin may include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, phenol novolak-type epoxy resin, cyclic aliphatic epoxy resin, and aliphatic polyglycidyl ether.

For example, cardo-based resins include fluorene-containing compounds such as 9,9-bis(4-oxiranylmethoxyphenyl)fluorene; Benzene tetracarboxylic acid dianhydride, naphthalene tetracarboxylic acid dianhydride, biphenyl tetracarboxylic acid dianhydride, benzophenone tetracarboxylic acid dianhydride, pyromellitic dianhydride, cyclobutane tetracarboxylic acid dianhydride, Anhydride compounds such as rylene tetracarboxylic acid dianhydride, tetrahydrofuran tetracarboxylic acid dianhydride, and tetrahydrophthalic acid anhydride; Glycol compounds such as ethylene glycol, propylene glycol, and polyethylene glycol; Alcohol compounds such as methanol, ethanol, propanol, n-butanol, cyclohexanol, and benzyl alcohol; solvent compounds such as propylene glycol methyl ethyl acetate and N-methylpyrrolidone; Phosphorus compounds such as triphenylphosphine; and amine or ammonium salt compounds such as tetramethylammonium chloride, tetraethylammonium bromide, benzyldiethylamine, triethylamine, tributylamine, and benzyltriethylammonium chloride.

The binder resin has reactivity to light or heat and can improve the dispersibility of quantum dot particles. Additionally, it can act as a binder resin for quantum dots and can be used as a support for cured patterns.

In some embodiments, the binder resin may be included in about 5 to 80% by weight of the total solid weight of the curable composition. Within the above range, the solubility in the developer is sufficient so that pattern formation can be facilitated. Additionally, film reduction in the pixel portion of the exposed area can be prevented during development, thereby reducing omission of non-pixel portions. Preferably, it may be included in about 10 to 70% by weight of the total solid weight of the curable composition.

menstruum

In some embodiments, the curable composition may include a solvent. The solvent may include an organic solvent that sufficiently dissolves the quantum dot particles and binder resin described above and does not cause precipitation of components of the composition.

When the curable composition contains quantum dot particles, it is difficult to use polar organic solvents such as propylene glycol monomethyl ether acetate and ethylene diglycol methyl ethyl ether, which are generally used in the manufacturing process of color filters or image display devices. .

However, as described above, the curable composition according to exemplary embodiments allows the use of polar organic solvents and improves light efficiency as a ligand having an ester group and an ether group is disposed on the surface of the quantum dot.

Examples of the solvent include ethylene glycol monoalkyl ethers; Diethylene glycol dialkyl ethers; ethylene glycol alkyl ether acetate; alkylene glycol alkyl ether acetates; propylene glycol monoalkyl ethers; propylene glycol dialkyl ethers; propylene glycol alkyl ether propionates; Butyldiol monoalkyl ethers; Butanediol monoalkyl ether acetate; Butanediol monoalkyl ether propionates; Dipropylene glycol dimethyl ether, dipropylene glycol dialkyl ether; Aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; Ketones such as methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, methyl-n-propyl ketone, methyl-n-butyl ketone, methyl-n-amyl ketone, and 2-heptanone ; Alcohols such as methanol and ethanol; esters such as 2-hydroxyethyl propionate, 2-hydroxy-2-methylethyl propionate, hydroxyethyl acetate, and methyl 2-hydroxy-3-methylbutanoate; Cyclic ethers such as tetrahydrofuran and pyran; Cyclic esters such as γ-butyrolactone, etc. can be mentioned. These may be used alone or in combination of two or more types. Preferably, the solvent may include propylene glycol monomethyl ether (PGME) and/or propylene glycol monomethyl ether acetate (PGMEA).

The solvent may be included in the remaining amount excluding the components of the composition described above, for example, the remaining amount excluding the quantum dot particles, or the remaining amount excluding the quantum dot particles, binder resin, and other additive components.

In some embodiments, the solvent may be included in about 40 to 95% by weight, preferably about 45 to 85% by weight, of the total weight of the curable composition, considering the applicability and drying properties of the composition. Within the above range, the applicability and drying properties of the composition can be improved, and the coating can be easily formed through an application method using a spin coater, slit and spin coater, slit coater, die coater, curtain flow coater, inkjet, etc. .

polymerizable compound

In some embodiments, the curable composition may include a polymerizable compound. A polymerizable compound is a compound that can be polymerized or cross-linked by the action of a polymerization initiator, which will be described later, and can increase the cross-linking density during the manufacturing process and strengthen the mechanical properties of the cured pattern.

The polymerizable compound may be used without particular limitation as long as it is used in the art, and may include, for example, a monofunctional monomer, a difunctional monomer, or a trifunctional or more polyfunctional monomer. These may be used alone or in combination of two or more.

The monofunctional monomer may be nonylphenylcarbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexylcarbitol acrylate, 2-hydroxyethyl acrylate, N-vinylpyrrolidone, etc. .

Bifunctional monomers include 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and bisphenol A. It may be (acryloyloxyethyl) ether, 3-methylpentanediol di(meth)acrylate, etc.

The multifunctional monomers include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate. Acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth) ) Acrylate, dipentaerythritol hexa(meth)acrylate, etc.

In some embodiments, the content of the polymerizable compound may be about 30 to 85% by weight, preferably about 40 to 80% by weight, based on the total solid weight of the curable composition. When the polymerizable compound is included in the above content range, the durability of the photocurable film can be improved, and the resolution of the composition during the development process can be improved.

polymerization initiator

In some embodiments, the curable composition may include a polymerization initiator.

The polymerization initiator may be used without particular limitation as long as it can induce a crosslinking reaction or polymerization reaction of the polymerizable compound through, for example, an exposure process. For example, the polymerization initiator may be an acetophenone-based compound, a benzophenone-based compound, a benzoin-based compound, a triazine-based compound, a biimidazole-based compound, a thioxanthone-based compound, an oxime ester-based compound, etc., preferably An oxime ester-based compound may be used.

The oxime ester compounds include o-ethoxycarbonyl-α-oxymino-1-phenylpropan-1-one, 1,2-octadione-1-(4-phenylthio)phenyl-2-(o-benzoyl) Oxime), ethanone, -1-(9-ethyl)-6-(2-methylbenzoyl-3-yl)-,1-(o-acetyloxime), etc., and commercially available products include CGI-124 ( Ciba Geigi), CGI-224 (Shiba Geigi), Irgacure OXE-01 (BASF), Irgacure OXE-02 (BASF), N-1919 (Adeka), NCI-831 (Adeka), etc. You can. These may be used alone or in combination of two or more.

In some embodiments, a polymerization initiation aid may be additionally used to improve the sensitivity of the curable composition. Examples of the polymerization initiation aid include amine compounds, carboxylic acid compounds, and organic sulfur compounds having a thiol group.

In some embodiments, the polymerization initiator may be included in an amount of about 0.1 to 10% by weight, preferably about 0.1 to 5% by weight, based on the total weight of solids of the curable composition. Within the above range, the efficiency and resolution of the exposure process can be improved without impairing the durability of the curable composition.

Other additives

The curable composition according to exemplary embodiments may further include additives such as fillers, other polymer compounds, curing agents, leveling agents, adhesion promoters, antioxidants, ultraviolet absorbers, agglomeration inhibitors, and chain transfer agents, as needed.

Additionally, quantum dot particles according to exemplary embodiments may include other organic or inorganic ligands on their surfaces to the extent that they do not impair the properties of the ligand according to exemplary embodiments. The organic or inorganic ligand forms a coordination bond on the surface of the quantum dot particle and may play a role in improving the dispersibility and luminescence properties of the quantum dot particle.

For example, the organic ligands include trioctylphosphine, trioctylphosphine oxide, oleic acid, oleylamine, octylamine, trioctylamine, hexadecylamine, octanethiol, dodecanethiol, hexylphosphonic acid, and tetradecylphosph. It may include phonetic acid, octylphosphinic acid, etc. The inorganic ligand may include inorganic substances such as halogen, metal halide, chalcogen, metal chalcogenide, metal hydroxide, and SCN-. These may be used alone or in combination of two or more.

<Curing pattern and image display device>

The present invention provides a cured pattern manufactured from a curable composition according to exemplary embodiments and an image display device including the cured pattern. For example, the cured pattern can be used as a color filter in an image display device, as will be described later.

In forming the cured pattern, a photosensitive film may be formed by applying the curable composition according to exemplary embodiments on a substrate. Application methods include, for example, inkjet printing, spin coating, flexible coating, roll coating, slit and spin coating, or slit coating. After forming the photosensitive film, a pre-baking process may be performed to remove volatile components such as solvents.

After this, an exposure process can be performed to form a photocurable film. In order to form a desired pattern, ultraviolet rays may be irradiated through an exposure mask of a predetermined type. For example, curing may occur in the area irradiated with ultraviolet rays. As the ultraviolet rays, g-rays (wavelength: 436 nm), h-rays (wavelength: 405 nm), i-rays (wavelength: 365 nm), etc. can be used.

After the exposure process, a development process may be performed to form a cured pattern. For example, a cured pattern can be formed by removing non-exposed areas using an alkaline developer. Alternatively, a cured pattern can be formed by removing the exposed portion using an alkaline developer. The development process includes liquid addition method, dipping method, spray method, etc. After the exposure process or the development process, a post baking process may be further performed.

According to example embodiments, the cured pattern may be used in a color filter. The color filter including the cured pattern can be applied to various image display devices such as an electroluminescence display, a plasma display, and a field emission display as well as a typical liquid crystal display.

The color filter may include a substrate and a cured pattern layer formed on top of the substrate. For example, the substrate may be the color filter itself, or may be a portion where the color filter is located in a display device, etc. The substrate may be glass, silicon, silicon oxide, or a polymer substrate, and the polymer substrate may be polyethersulfone (PES) or polycarbonate (PC).

When the color filter is applied to an image display device, the quantum dot particles included in the color filter emit light by themselves by the light of the light source, so light efficiency may be excellent. In addition, color reproducibility can be excellent as colored light is emitted, and viewing angles can also be improved because light is emitted in all directions by quantum dot particles.

In some embodiments, the color filter may include a transparent pattern layer, a green pattern layer that converts incident blue light into green light, or a red pattern layer that converts incident blue light into red light. The green pattern layer may include green quantum dots that emit green light when irradiated with blue light, and the red pattern layer may include red quantum dots that emit red light when irradiated with blue light.

In some embodiments, the image display device may include a color filter including a transparent pattern layer, a green pattern layer, and a red pattern layer. In this case, a light source that emits blue light can be used as the light source of the image display device.

As described above, the curable composition may have excellent dispersibility in polar solvents as it contains a ligand having an ester group and an ether group, and thus a cured pattern with excellent compatibility and optical properties can be provided. Accordingly, the loss of light irradiated to the color filter including the cured pattern can be minimized and converted efficiently, thereby realizing excellent light efficiency.

Hereinafter, experimental examples including specific examples and comparative examples are presented to aid understanding of the present invention, but these are only illustrative of the present invention and do not limit the scope of the appended claims, and do not limit the scope and technical idea of the present invention. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

Synthesis example: quantum dot particles

Synthesis Example 1: A-1

A solution in which quantum dot particles of the InP/ZnSe/ZnS core-shell structure are dispersed (quantum dot solid content 30%) is centrifuged twice using acetone and ethanol, and then vacuum dried to obtain a powder of quantum dot particles. Afterwards, 30 g of the quantum dot particles are completely dissolved using 100 g of toluene, and 30 g of the compound of the following formula 2-1 is added thereto. Afterwards, the reaction was performed for 15 hours while maintaining 50°C in a nitrogen atmosphere to prepare quantum dot particles containing a ligand on the surface.

[Formula 2-1]

Synthesis Example 2: A-2

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that a compound represented by Formula 2-5 below was used instead of the compound represented by Formula 2-1.

[Formula 2-5]

Synthesis Example 3: A-3

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that a compound represented by Formula 2-17 below was used instead of the compound represented by Formula 2-1.

[Formula 2-17]

Synthesis Example 4: A-4

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that a compound represented by Formula 2-18 below was used instead of the compound represented by Formula 2-1.

[Formula 2-18]

Synthesis Example 5: A-5

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that a compound represented by Formula 2-21 below was used instead of the compound represented by Formula 2-1.

[Formula 2-21]

Synthesis Example 6: A-6

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that the compound represented by Formula 3 below was used instead of the compound represented by Formula 2-1.

[Formula 3]

Synthesis Example 7: A-7

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that a compound represented by Formula 4 below was used instead of the compound represented by Formula 2-1.

[Formula 4]

Synthesis Example 8: A-8

Quantum dot particles containing a ligand on the surface were prepared in the same manner as in Synthesis Example 1, except that a compound represented by Formula 5 below was used instead of the compound represented by Formula 2-1.

[Formula 5]

Examples and Comparative Examples

(1) Preparation of curable composition

A curable composition was prepared by mixing the ingredients listed in Table 1 below in the corresponding amounts (% by weight).

division
(weight%) quantum dot particles binder resin polymerizable compound polymerization initiator menstruum Example 1 15
(A-1) 10 1.6 0.1 73.3 Example 2 15
(A-2) 10 1.6 0.1 73.3 Example 3 15
(A-3) 10 1.6 0.1 73.3 Example 4 15
(A-4) 10 1.6 0.1 73.3 Example 5 15
(A-5) 10 1.6 0.1 73.3 Comparative Example 1 15
(A-6) 10 1.6 0.1 73.3 Comparative Example 2 15
(A-7) 10 1.6 0.1 73.3 Comparative Example 3 15
(A-8) 10 1.6 0.1 73.3

The specific ingredient names listed in Table 1 are as follows.

Quantum dot particles (A)

1) A-1: Quantum dot particles prepared in Synthesis Example 1

2) A-2: Quantum dot particles prepared in Synthesis Example 2

3) A-3: Quantum dot particles prepared in Synthesis Example 3

4) A-4: Quantum dot particles prepared in Synthesis Example 4

5) A-5: Quantum dot particles prepared in Synthesis Example 5

6) A-6: Quantum dot particles prepared in Synthesis Example 6

7) A-7: Quantum dot particles prepared in Synthesis Example 7

8) A-8: Quantum dot particles prepared in Synthesis Example 8

Binder Resin (B)

Acrylic binder resin (SPCY-1L, manufactured by Showa Polymers)

Polymerizable Compound (C)

Dipentaerythritol hexaacrylate (KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.)

Polymerization initiator (D)

Irgaqure-907 (manufactured by BASF)

Solvent (E)

Propylene glycol monomethyl ether acetate (PGMEA)

(2) Manufacture of curly filter

After applying the curable composition according to Examples and Comparative Examples on a glass substrate by spin coating, it was placed on a heating plate and maintained at a temperature of 100 degrees for 3 minutes to form a thin film. A test photomask having a square transmission pattern of 20mm The ultraviolet light source was irradiated with light at an exposure dose of 200 mJ/cm ² (wavelength 365 nm) in an atmospheric atmosphere using an ultra-high pressure mercury lamp (USH-250D, manufactured by Ushio Denki Co., Ltd.). Afterwards, the thin film was developed by immersing it in an aqueous KOH solution of pH 10.5 for 80 seconds.

Afterwards, it was washed with distilled water, dried by blowing nitrogen gas, and heated in an oven at 150°C for 10 minutes to prepare a color filter. The pattern thickness of the manufactured color filter was 3.0 μm.

Experiment example

(1) Evaluation of dispersibility of quantum dot particles

The quantum dot particles prepared in Synthesis Examples 1 to 8 were dispersed in PGMEA (Propylene Glycol, Mono Methyl, Ether, Acetate) solvent to prepare a quantum dot dispersion solution containing 50% by weight of solid content. Afterwards, the particle size of the prepared quantum dot dispersion solution was measured using a particle size analyzer. The lower the dispersibility, the larger the particle size of the quantum dots may be due to agglomeration. The evaluation results are shown in Table 2 below.

division Synthesis Example 1 Synthesis Example 2 Synthesis Example 3 Synthesis Example 4 Synthesis Example 5 Synthesis Example 6 Synthesis Example 7 Synthesis Example 8 Particle size (nm) 12 12 14 17 15 1900 11 10

Referring to Table 2, it can be seen that in the case of Synthesis Examples 1 to 5 containing ligands according to exemplary embodiments, the particle size of the quantum dot particles in the dispersion solution is low, and accordingly, it can be predicted that the dispersibility of the quantum dot particles is excellent. You can.

On the other hand, in the case of Synthesis Example 6, which includes a ligand with a general alkyl chain structure, it can be seen that the particle size is very high, and accordingly, it can be seen that the dispersibility in a polar organic solvent such as PGMEA is deteriorated.

(2) Storage stability evaluation

The curable compositions according to the examples and comparative examples were left at room temperature, and the viscosity over time was measured using a viscometer (manufactured by Brookfield). There is little change in viscosity over time, and the lower the viscosity, the better the storage stability. The evaluation results are shown in Table 3 below.

(3) Evaluation of light efficiency and durability

Light efficiency was calculated by irradiating blue light to the manufactured color filter and measuring the degree of conversion to green light. Light efficiency was measured using QE-2000 (manufactured by Otsuka Corporation), and as blue light of 450 nm was applied to the color filter, all green light emitted in all directions was absorbed and calculated as an integral value. Light efficiency was calculated as a percentage of the increase in the peak converted to green light compared to the decrease in the blue light absorption peak.

In addition, after the color filter was left in a blue light source at room temperature for 7 days, the light efficiency was measured and the decrease was calculated. Since light efficiency decreases due to oxidation of quantum dot particles, light durability can be confirmed by measuring light efficiency after leaving. Light durability was expressed as a percentage of the ratio of light efficiency after neglect to initial light efficiency. Higher durability means superior oxidation stability.

The evaluation results are shown in Table 3 below.

division storage stability
(viscosity, cp) light efficiency
(%) durability
(%) Early 2 weeks 4 weeks Early After neglect Example 1 10.1 10.6 11.1 76 67 88.1 Example 2 10.5 10.9 11.3 74 66 89.1 Example 3 11.2 11.5 11.8 78 69 88.5 Example 4 10.3 10.6 11.2 80 73 91.2 Example 5 10.8 11.3 11.6 81 74 91.3 Comparative Example 1 13.2 13.6 14.5 77 70 90.9 Comparative Example 2 10.5 11.8 13.1 59 30 50.8 Comparative Example 3 10.1 11.5 12.9 61 29 47.5

Referring to Table 3, it can be seen that the change in viscosity over time is small in the case of color filters manufactured using the curable composition according to exemplary embodiments. In addition, it can be confirmed that the initial light conversion rate is high and durability is excellent as oxidation of the quantum dot particles is prevented.

On the other hand, in Comparative Examples 1 to 3, it can be seen that the change in viscosity over time is large as the storage stability is deteriorated. The initial light conversion rate is low, and it can be seen that the light conversion rate decreases significantly over time.

Claims (11)

Quantum dot particles comprising a ligand represented by Formula 1:
[Formula 1]

(In Formula 1 above,
R ₁ is a single bond or a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms,
R ₂ is a divalent aliphatic hydrocarbon group having 3 to 8 carbon atoms,
R ₃ is a cyclic hydrocarbon group having 3 to 10 replaceable carbon atoms or an aromatic hydrocarbon group having 6 to 10 replaceable carbon atoms).
delete The quantum dot particle of claim 1, wherein the ligand includes at least one selected from the group consisting of compounds represented by the following formulas 2-18 to 2-21:
[Formula 2-18]

[Formula 2-19]

[Formula 2-20]

[Formula 2-21]
.
The quantum dot particle of claim 1, wherein the quantum dot particle includes at least one selected from the group consisting of a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, or a compound containing the same.
The quantum dot particle of claim 1, wherein the quantum dot particle includes a core and a shell covering the core.
The quantum dot particle of claim 5, wherein the core includes indium (In) or phosphorus (P), and the shell includes zinc (Zn), selenium (Se), or sulfur (S).
The method of claim 6, wherein the shell includes a first shell layer covering the core and a second shell layer covering the first shell layer,
The core includes InP or InZnP, the first shell layer includes ZnSe or ZnSeS, and the second shell layer includes ZnS, quantum dot particles.
A curable composition comprising quantum dot particles according to claim 1.
The curable composition of claim 8, further comprising at least one of a binder resin, a polymerizable compound, a polymerization initiator, and a solvent.
A cured pattern formed from the curable composition according to claim 8.
An image display device comprising a curing pattern according to claim 10.