TWI908138B - Curable composition, cured layer using the composition, and display device including the cured layer - Google Patents

Abstract

Provided are a curable composition, a cured layer manufactured using the curable composition, and a display device including the cured layer, the curable composition including (A) quantum dots; and (B) polymerizable compound, wherein the polymerizable compound includes a first polymerizable compound including a substituted or unsubstituted C3 to C20 cycloalkylene group and a polymerizable functional group, the polymerizable functional group includes a (meth)acrylate group, an epoxy group, an oxetane group, a vinyl group, or a combination thereof.

Description

Curable composition, cured layer using said composition, and display device including said cured layer.

[Cross-reference to related applications]

This application claims priority and interests in Korean Patent Application No. 10-2023-0087915 filed with the Korean Intellectual Property Office on July 6, 2023, and Korean Patent Application No. 10-2024-0073968 filed with the Korean Intellectual Property Office on June 5, 2024, the entire contents of which are incorporated herein by reference.

This disclosure relates to a curable composition, a cured layer using said composition, and a display device including said cured layer.

In the case of general quantum dots, the solvents in which quantum dots can be dispersed are limited due to the existence of hydrophobic surface properties, and therefore it is difficult to introduce them into polar systems (such as adhesives or curable monomers).

For example, even in the case of quantum dot ink compositions, which are under active research, the polarity is relatively low in the initial steps, and quantum dot ink compositions can be dispersed in solvents used in curable compositions with high hydrophobicity. Therefore, since it is difficult to contain 20% by weight or more of quantum dots in the total composition, it is impossible to increase the light efficiency of the ink beyond a certain level. Even if additional quantum dots are added and dispersed to increase light efficiency, the viscosity will exceed the range that allows for inkjet printing, and therefore the processability may be unsatisfactory.

To achieve a viscosity range suitable for inkjet printing, one method involves reducing the ink solids content by dissolving a solvent at 50% by weight or more of the total composition. This method also provides somewhat satisfactory viscosity results. However, while the viscosity may be considered satisfactory, issues such as nozzle drying and clogging due to solvent evaporation during inkjet printing, as well as the reduction in monolayer thickness over time after inkjet printing, can worsen, and it becomes difficult to control thickness deviations after curing. Therefore, it is difficult to apply this method to actual manufacturing processes.

Therefore, solvent-free quantum dot inks, which do not contain solvents, are the most desirable form for practical application. Current technology for applying quantum dots themselves to solvent-based compositions is somewhat limited.

In the case of solvent-free curable compositions (quantum dot ink compositions), the presence of excessive polymerizable compounds can lead to nozzle drying due to volatility, resulting in clogging and spraying failure. Furthermore, the evaporation of the ink composition sprayed within the patterned separator pixels can cause a reduction in single-film thickness. Therefore, various efforts are underway to improve the optical properties of solvent-free curable compositions.

One embodiment provides a curable composition with excellent deposition stability and optical properties.

Another embodiment provides a cured layer manufactured using the said curable composition.

Another embodiment provides a display device that includes the cured layer.

One embodiment provides a curable composition comprising: (A) quantum dots; and (B) a polymerizable compound, wherein the polymerizable compound comprises a first polymerizable compound comprising substituted or unsubstituted C3 to C20 cycloalkyl groups and polymerizable functional groups, and the polymerizable functional groups comprising (meth)acrylate groups, epoxy groups, oxocyclobutane groups, vinyl groups, or combinations thereof.

The first polymerizable compound may include a repeating unit represented by Formula 1. [Formula 1]

In Formula 1, ^L1 , ^L2 and ^L4 are each independently a single-bonded or substituted or unsubstituted C1 to C20 alkyl group, and ^L3 and ^L5 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkyl group, or a substituted or unsubstituted C3 to C20 cycloalkyl group, with the restriction that at least one of ^L3 and ^L5 must be a substituted or unsubstituted C3 to C20 cycloalkyl group.

The first polymerizable compound may further include a linker group represented by Formula 2. [Formula 2]

In Formula 2, ^L7 is a single-bonded or substituted or unsubstituted C1 to C20 alkylene group, and ^L6 and ^L8 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkylene group, or a substituted or unsubstituted C3 to C20 cycloalkylene group, with the restriction that at least one of ^L6 and ^L8 must be a substituted or unsubstituted C3 to C20 cycloalkylene group.

The first polymerizable compound may include (meth)acrylate, epoxy, oxocyclobutane, vinyl, or combinations thereof at both terminals.

The first polymerizable compound can be represented by chemical formula 3. [Chemical formula 3]

In Formula 3, ^R1 and ^R2 are each independently represented by any one of Formulas R-1 to R-4; ^L1 , ^L2 , ^L4 , and ^L7 are each independently a single-bonded or substituted or unsubstituted C1 to C20 alkylene group; ^L3 , ^L5 , ^L6 , and ^L8 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkylene group or a substituted or unsubstituted C3 to C20 cycloalkylene group, with the restriction that at least one of ^L3 and ^L5 must be a substituted or unsubstituted C3 to C20 cycloalkylene group, and at least one of ^L6 and ^L8 must be a substituted or unsubstituted C3 to C20 cycloalkylene group, and n is an integer from 0 to 100. [Formula R-1] [Chemical formula R-2] [Chemical formula R-3] [Chemical formula R-4] In the chemical formulas R-1 to R-4, ^R3 and ^R4 are each independently a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group, and ^L9 to ^L11 are each independently a single bond or a substituted or unsubstituted C1 to C20 alkyl group.

In Formula 1, ^L3 , ^L5 , ^L6 and ^L8 may all be substituted or unsubstituted C3 to C20 cycloalkyl groups.

The polymerizable compound may further include a second polymerizable compound having a different structure from the first polymerizable compound.

The second polymerizable compound may include a compound represented by chemical formula 4. [Chemical formula 4]

In Formula 4, ^L12 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or an ether group (*-O-*), ^L13 and ^L14 are each independently a single bond or a substituted or unsubstituted C1 to C10 alkyl group, and ^R5 and ^R6 are each independently a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group.

The first polymerizable compound and the second polymerizable compound can be contained in a weight ratio of 1:9 to 9:1.

The first polymerizable compound and the second polymerizable compound can be contained in a weight ratio of 5:5 to 1:9.

The curable composition may be a solvent-free curable composition.

Based on the total amount of solvent-free curable components, solvent-free curable components may contain: 5% to 60% by weight of quantum dots; and 40% to 95% by weight of polymerizable compounds.

The curable composition may further include a polymerization initiator, a light diffusing agent, a polymerization inhibitor, or a combination thereof.

Light diffusing agents may include barium sulfate, calcium carbonate, titanium dioxide, zirconium oxide, or combinations thereof.

Quantum dots can include cadmium-free luminescent materials.

Quantum dots can have an InP/ZnS core/shell structure or an InP/ZnSe/ZnS core/first shell/second shell structure.

Quantum dots may include a core containing silver (Ag), indium (In), gallium (Ga), and sulfur (S) and a shell containing at least two of the groups selected from silver (Ag), gallium (Ga), zinc (Zn), and sulfur (S).

The curable composition may further include: malonic acid; 3-amino-1,2-propanediol; silane coupling agent; leveling agent; fluorine surfactant; or combinations thereof.

The curable composition may further include a solvent, in which case, by total amount of the curable composition, the curable composition may contain: 1% to 40% by weight of quantum dots; 1% to 20% by weight of a polymerizable compound; and 40% to 80% by weight of a solvent.

The curable composition can have a viscosity of 10 centipoise to 50,000 centipoise at 25°C.

Another embodiment provides a curing layer produced using the curable composition.

Another embodiment provides a display device that includes the cured layer.

Other embodiments of the present invention are described in detail below.

According to the embodiment, the curable component is a high-viscosity ink component that can be used not only in general inkjet printing processes but also in electrohydrodynamic (EHD) inkjet printing processes. Compared with traditional curable components, it has improved deposition stability and optical properties, and specifically, it has excellent lightfastness reliability.

Embodiments of the present invention are described in detail below. However, these embodiments are exemplary and the present invention is not limited thereto, and the present invention is defined by the scope of the claims.

Unless otherwise defined, "alkyl" as used herein refers to C1 to C20 alkyl, "alkenyl" refers to C2 to C20 alkenyl, "cycloalkenyl" refers to C3 to C20 cycloalkenyl, "heterocycloalkenyl" refers to C3 to C20 heterocycloalkenyl, "aryl" refers to C6 to C20 aryl, "arylalkyl" refers to C6 to C20 arylalkyl, "endylalkyl" refers to C1 to C20 endylalkyl, "endylaryl" refers to C6 to C20 endylaryl, "alkylendylaryl" refers to C6 to C20 alkylendylaryl, "endylheteroaryl" refers to C3 to C20 endylheteroaryl, and "endylalkoxy" refers to C1 to C20 endylalkoxy.

Unless otherwise specifically defined, "substituted" as used herein means that at least one hydrogen atom is replaced by a substituent selected from the following: halogen atom (F, Cl, Br, or I), hydroxyl, C1 to C20 alkoxy, nitro, cyano, amino, imino, azido, amido, hydrazine, hydrazone, carbonyl, aminomethyl, thiol, ester, ether, carboxyl, or a salt thereof. Sulfonic acid group or its salt, phosphoric acid or its salt, C1 to C20 alkyl, C2 to C20 alkenyl, C2 to C20 alkynyl, C6 to C20 aryl, C3 to C20 cycloalkyl, C3 to C20 cycloalkenyl, C3 to C20 cycloalkynyl, C2 to C20 heterocycloalkyl, C2 to C20 heterocycloalkenyl, C2 to C20 heterocycloalkynyl, C3 to C20 heteroaryl or combinations thereof.

Unless otherwise defined, “hybrid” as used herein refers to a chemical formula containing at least one heteroatom of N, O, S and P.

Unless otherwise defined, "(meth)acrylate" as used herein refers to both "acrylate" and "methacrylate", and "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid".

Unless otherwise defined, the term "combination" as used herein refers to a mixture or copolymer.

In this specification, unless otherwise defined, hydrogen bonds are located at the positions indicated in the chemical formula when the chemical bonds are not drawn where they should be.

Additionally, in this manual, unless otherwise defined, "*" refers to a point connected to the same or different atoms or chemical formulas.

In the following sections, each component constituting the curable composition according to the embodiments will be described in detail. Polymerizable compounds

The curable composition according to the embodiments comprises a first polymerizable compound as the polymerizable compound, the first polymerizable compound comprising substituted or unsubstituted C3 to C20 cycloalkyl groups and polymerizable functional groups, and the polymerizable functional groups comprising substituted or unsubstituted (meth)acrylate groups, substituted or unsubstituted epoxy groups, substituted or unsubstituted oxocyclobutane groups, substituted or unsubstituted vinyl groups, or combinations thereof. By this configuration, the curable composition according to the embodiments can significantly improve lightfastness reliability. When aryl groups such as phenyl groups are used instead of substituted or unsubstituted C3 to C20 cycloalkyl groups, or when aromatic ring linkers are included in the first polymerizable compound, lightfastness reliability may be greatly reduced, and the desired effect of the invention may be weakened, and therefore the structure of the first polymerizable compound may not include aromatic ring linkers.

For example, the polymerizable functional group may include (meth)acrylate, epoxy, vinyl, or combinations thereof. For example, the polymerizable functional group may include epoxy, vinyl, or combinations thereof. In this case, the solubility of the quantum dots, as described below, in the polymerizable compound can be further improved.

Meanwhile, Electrodynamic High-Density (EHD) inkjet printing is a direct-writing method that uses an electric field to spray and apply ink via hydrodynamic force. Compared to conventional inkjet printing, EHD inkjet printing offers advantages such as achieving nanoscale high resolution, high printing speed, and applicability to various inks. This represents a next-generation printing technology capable of producing micron and nanometer-sized structures and patterns of various shapes and sizes. The curable composition containing sub-dots according to the embodiment exhibits high viscosity and high lightfastness because it substantially comprises a polymerizable compound containing the aforementioned first polymerizable compound, and therefore can be directly applied to electrodynamic inkjet printing technology in addition to conventional inkjet printing.

For example, the first polymerizable compound may include a repeating unit (or linker) represented by Formula 1. [Formula 1]

In Formula 1, ^L1 , ^L2 and ^L4 are each independently a single-bonded or substituted or unsubstituted C1 to C20 alkyl group, and ^L3 and ^L5 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkyl group, or a substituted or unsubstituted C3 to C20 cycloalkyl group, with the restriction that at least one of ^L3 and ^L5 must be a substituted or unsubstituted C3 to C20 cycloalkyl group.

By including repeating units represented by Formula 1, the first polymerizable compound can maximize lightfastness reliability and improve deposition stability.

For example, in addition to the repeating unit represented by Formula 1, the first polymerizable compound may further include a linker group represented by Formula 2. [Formula 2]

In Formula 2, ^L7 is a single-bonded or substituted or unsubstituted C1 to C20 alkylene group, and ^L6 and ^L8 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkylene group, or a substituted or unsubstituted C3 to C20 cycloalkylene group, with the restriction that at least one of ^L6 and ^L8 must be a substituted or unsubstituted C3 to C20 cycloalkylene group.

For example, the first polymerizable compound may include (meth)acrylate, epoxy, oxocyclobutane, vinyl, or combinations thereof at both ends.

Both the repeating unit represented by Formula 1 and the linking group represented by Formula 2 comprise substituted or unsubstituted C3 to C20 cycloalkyl groups, and the first polymerizable compound comprising the repeating unit represented by Formula 1 and the linking group represented by Formula 2 comprises (meth)acrylate, epoxy, oxocyclobutane, vinyl, or combinations thereof at both ends. Due to the structural characteristics of the first polymerizable compound, the curable composition according to the embodiment exhibits excellent deposition stability and lightfastness reliability, while freely controlling viscosity from low to high at room temperature, and therefore can be freely applied to hydrodynamic spraying processes in addition to conventional inkjet processes.

For example, the curable composition can have a viscosity of 10 centipoise to 50,000 centipoise at 25°C. That is, the curable composition according to the embodiment can control the viscosity from low viscosity (10 centipoise) to high viscosity (50,000 centipoise) as needed at room temperature (20°C to 25°C), and therefore its applications can be extremely wide and diverse.

For example, the first polymerizable compound can be represented by chemical formula 3. [Chemical formula 3]

In Formula 3, ^R1 and ^R2 are each independently represented by any one of Formulas R-1 to R-4; ^L1 , ^L2 , ^L4 , and ^L7 are each independently a single-bonded or substituted or unsubstituted C1 to C20 alkylene group; ^L3 , ^L5 , ^L6 , and ^L8 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkylene group or a substituted or unsubstituted C3 to C20 cycloalkylene group, with the restriction that at least one of ^L3 and ^L5 must be a substituted or unsubstituted C3 to C20 cycloalkylene group, and at least one of ^L6 and ^L8 must be a substituted or unsubstituted C3 to C20 cycloalkylene group, and n is an integer from 0 to 100. [Formula R-1] [Chemical formula R-2] [Chemical formula R-3] [Chemical formula R-4] In the chemical formulas R-1 to R-4, ^R3 and ^R4 are each independently a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group, and ^L9 to ^L11 are each independently a single bond or a substituted or unsubstituted C1 to C20 alkyl group.

For example, in chemical formula 3, n can be an integer from 1 to 100.

For example, in Formula 1, ^L3 , ^L5 , ^L6 and ^L8 may all be substituted or unsubstituted C3 to C20 cycloalkyl groups.

For example, C3 to C20 pentylene alkyl groups can be pentylene hexyl groups.

For example, the first polymerizable compound may be represented by any of the chemical formulas 3-1 to 3-4, but is not necessarily limited to them. [Chemical Formula 3-1] [Chemical Formula 3-2] [Chemical Formula 3-3] [Chemical Formulas 3-4]

In chemical formulas 3-1 to 3-4, n is an integer equal to 1.

For example, a polymerizable compound may further include a second polymerizable compound having a structure different from that of the compound represented by Formula 1. That is, a polymerizable compound may include a first polymerizable compound and a second polymerizable compound having a different structure.

For example, the second polymerizable compound can be represented by chemical formula 4. [Chemical formula 4]

In Formula 4, ^L12 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or an ether group (*-O-*), ^L13 and ^L14 are each independently a single bond or a substituted or unsubstituted C1 to C10 alkyl group, and ^R5 and ^R6 are each independently a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group.

Even though the curable composition according to the embodiment comprises a first polymerizable compound and a second polymerizable compound represented by Formula 4 as polymerizable compounds, the effects of improving the optical properties and deposition stability of the curable composition can be achieved simultaneously, just as when the first polymerizable compound is used alone. The first polymerizable compound comprises Formula 1, Formula 2, and specific polymerizable functional groups at both ends. Specifically, when the first polymerizable compound and the second polymerizable compound are mixed, a much better effect can be achieved in terms of storage stability.

For example, compounds represented by Formula 4 may have a refractive index of 1.455 or less. If a compound represented by Formula 4 has a refractive index greater than 1.455, it is advantageous for improving optical properties, but may be disadvantageous for reducing reflectivity.

For example, a weight ratio of 1:9 to 9:1, such as 5:5 to 1:9, may contain a first polymerizable compound and a second polymerizable compound (e.g., a compound represented by chemical formula 4).

For example, the first polymerizable compound may be contained in an amount less than that of the second polymerizable compound (e.g., the compound represented by chemical formula 4).

For example, a compound represented by chemical formula 1 and a second polymerizable compound (e.g., a compound represented by chemical formula 4, etc.) can be contained in a weight ratio of 6:4 to 1:9.

When the first polymerizable compound is included in an amount less than that of the second polymerizable compound (e.g., a compound represented by chemical formula 4), for example in a weight ratio of 6:4 to 1:9, the curing rate of the curable composition according to the embodiment increases, thereby maximizing the simultaneous improvement of both the optical properties and the reflection reduction.

For example, a compound represented by formula 4 can be represented by any of formulas 4-1 to 4-3, but is not necessarily limited to these. [Formula 4-1] [Chemical Formula 4-2] [Chemical Formula 4-3]

For example, in addition to compounds represented by chemical formulas 4-1 to 4-3, a second polymerizable compound having a structure different from that of the first polymerizable compound may further include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, pentaerythritol hexaacrylate, bisphenol A diacrylate, trihydroxymethylpropane triacrylate, novolacepoxyacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, or combinations thereof.

In addition to polymerizable compounds, monomers commonly used in conventional thermosetting or photocurable compositions can be used. For example, the monomers may further include oxocyclobutane monomers, such as bis[1-ethyl(3-oxocyclobutyl)] methyl ether.

The polymerizable compound may be included in an amount of 40% to 95% by weight, for example, 50% to 90% by weight, based on the total amount of the solvent-free curable composition. When the polymerizable compound is included within the range, a solvent-free curable composition having a viscosity suitable for inkjet printing can be prepared, and the quantum dots in the prepared solvent-free curable composition can have improved dispersibility, thereby improving optical properties.

For example, polymerizable compounds can have molecular weights ranging from 170 g/mol to 1,000 g/mol. When the molecular weight of a polymerizable compound is within this range, it is advantageous for inkjet printing because it does not impair the optical properties of quantum dots and does not increase the viscosity of the composition.

Furthermore, when the curable composition contains a solvent, the polymerizable compound may be included in an amount of 1% to 20% by weight, 1% to 15% by weight, or, for example, 5% to 15% by weight, based on the total amount of the curable composition. When the polymerizable compound is included within the above range, the optical properties of the quantum dots can be improved. Quantum Dots

For example, quantum dots can have the maximum fluorescence emission wavelengths in the range of about 500 nanometers to about 680 nanometers.

For example, when the curable composition according to the embodiment is a solvent-free curable composition, quantum dots may be included in amounts of 5% to 60% by weight, for example 10% to 60% by weight, for example 20% to 60% by weight, for example 30% to 50% by weight. When quantum dots are included within the above range, high light retention and light efficiency can be achieved even after curing.

For example, when the curable composition according to the embodiment is a solvent-containing curable composition, quantum dots may be included in an amount from 1% to 40% by weight, for example, from 3% to 30% by weight, based on the total amount of the curable composition. When quantum dots are included within the above range, the light conversion efficiency is improved while the pattern characteristics and developing properties are not impaired, and thus improved processability can be obtained.

For example, quantum dots absorb light in the wavelength range of 360 nm to 780 nm, such as 400 nm to 780 nm, and emit fluorescence in the wavelength range of 500 nm to 700 nm, such as 500 nm to 580 nm, or in the wavelength range of 600 nm to 680 nm. That is, quantum dots can have the maximum fluorescence emission wavelength (fluorescence _λem ) in the 500 nm to 680 nm range.

Quantum dots can each independently have a full width at half maximum (FWHM) of 20 to 100 nanometers, for example, 20 to 50 nanometers. When quantum dots have a full width at half maximum (FWHM) within this range, color reproducibility is increased due to high color purity when used as color materials in color filters.

Quantum dots can be organic materials, inorganic materials, or mixtures of organic and inorganic materials, each independently.

Quantum dots can each be independently composed of a core and a shell surrounding the core, and the core and shell can each independently have a core, core/shell, core/first shell/second shell, alloy, alloy/shell, etc., composed of II-IV, III-V, etc., but are not limited to these.

For example, the core may comprise at least one material selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, GaN, GaP, GaAs, InP, InAs, and alloys thereof, but is not limited thereto. The shell surrounding the core may comprise at least one material selected from CdSe, ZnSe, ZnS, ZnTe, CdTe, PbS, TiO, SrSe, HgSe, and alloys thereof, but is not limited thereto.

In practice, due to the recent increase in global attention to the environment and the strengthening of restrictions on toxic materials, cadmium-free luminescent materials (InP/ZnS, InP/ZnSe/ZnS, etc.) with slightly lower quantum efficiency (quantum yield) but no harm to the environment are used to replace luminescent materials with cadmium-based cores, but this is not necessarily limited to these.

In embodiments, quantum dots may include a core containing silver (Ag), indium (In), gallium (Ga), and sulfur (S) and a shell containing at least two (or at least three) of the groups selected from silver (Ag), gallium (Ga), zinc (Zn), and sulfur (S). In this case, the quantum dot may have more than one type of ligand. For example, a quantum dot may include a first ligand containing a halogen, a second ligand containing an alkyl and/or alkoxyamine group, or a combination thereof, but is not limited thereto.

In the case of core/shell structured quantum dots, the size (average particle size) of each quantum dot, including the shell, can be 1 nanometer to 15 nanometers, for example, 5 nanometers to 15 nanometers.

For example, quantum dots can each independently include red quantum dots, green quantum dots, or combinations thereof. Red quantum dots can each independently have an average particle size of 10 nanometers to 15 nanometers. Green quantum dots can each independently have an average particle size of 5 nanometers to 8 nanometers.

On the other hand, to achieve dispersion stability of quantum dots, the curable composition according to the embodiments may further include a dispersant. The dispersant contributes to the uniform dispersion of photoconverting materials, such as quantum dots, in the photosensitive resin composition, and may include nonionic, anionic, or cationic dispersants. Specifically, the dispersant may be a polyalkylene glycol or its ester, polyoxyalkylene, polyol ester epoxy alkylation product, alcohol epoxy alkylation product, sulfonate, sulfonate, carboxylic acid ester, carboxylic acid, alkylamide epoxy alkylation product, alkylamine, etc., and may be used alone or in mixtures of two or more. Based on the solid content of the light-converting material (e.g., quantum dots), a dispersant in amounts ranging from 0.1 wt% to 100 wt%, for example, from 10 wt% to 20 wt%, can be used.

For example, quantum dots can be surface-modified using ligands with polar groups (e.g., ligands with high affinity for polymerizable compounds). In the case of surface-modified quantum dots as described above, it is very easy to prepare high-concentration or highly concentrated quantum dot dispersions (improved dispersibility of quantum dots in polymerizable compounds), which can have a significant effect on improving light efficiency and is particularly desirable in the implementation of solvent-free curable compositions.

For example, ligands with polar groups can have structures that have a high affinity for the chemical structure of polymerizable compounds.

For example, a ligand with a polar group can be represented by any of the compounds from formula A to formula Q, but is not necessarily limited to these. [Formula A] [Chemical Formula B] [Chemical Formula C] [Chemical Formula D]

In chemical formula D, m1 is an integer between 0 and 10. [Chemical formula E] [Chemical formula F] [Chemical Formula G] [Chemical formula H] [Chemical Formula I] [Chemical Formula J] [Chemical formula K] [Chemical Formula L] [Chemical Formula M] [Chemical formula N] [Chemical formula O] [Chemical formula P] [Chemical Formula Q]

When using the aforementioned ligands, the surface modification of quantum dots is easier, and when surface-modified quantum dots using the ligands are added to the polymerizable compound and stirred, an extremely transparent dispersion is obtained, indicating that the surface modification of quantum dots is highly successful. Light diffusing agent

According to the embodiments, the curable composition may further include a light diffusing agent.

For example, light diffusing agents may include barium sulfate ( _BaSO4 ), calcium carbonate ( _CaCO3 ), titanium dioxide ( _TiO2 ), zirconium oxide ( _ZrO2 ), or combinations thereof.

The light diffusing agent can reflect the light that was not absorbed in the quantum dots and allow the quantum dots to absorb the reflected light again. That is, the light diffusing agent can increase the amount of light absorbed by the quantum dots and increase the light conversion efficiency of the curable composition.

The light diffusing agent can have an average particle size ( _D50 ) of 150 nm to 250 nm, specifically 180 nm to 230 nm. When the average particle size of the light diffusing agent is within the range described above, it can have better light diffusion and increase light conversion efficiency.

The light diffusing agent can be included in amounts ranging from 1% to 20% by weight, for example, 2% to 15% by weight, or for example, 3% to 10% by weight, based on the total amount of the curable component. When the light diffusing agent is included in an amount less than 1% by weight, it is difficult to expect an improvement in light conversion efficiency by using the light diffusing agent, while when it is included in an amount greater than 20% by weight, quantum dot deposition problems may occur. Polymerization initiator

The curable composition according to the embodiments may further include a polymerization initiator, such as a photopolymerization initiator, a thermal polymerization initiator, or a combination thereof.

The polymerization initiator can be any initiator commonly used in photosensitive resin compositions, and may include, for example, acetophenone-based compounds, benzophenone-based compounds, thioxanthone-based compounds, benzoin-based compounds, triazine-based compounds, oxime-based compounds, aminoketone-based compounds, etc., but is not necessarily limited to these.

Examples of acetophenone compounds include 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylacetophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4-phenoxyacetophenone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinylprop-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-but-1-one, etc.

Examples of benzophenone compounds include benzophenone, benzoyl benzoate, benzoyl methyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, benzoyl acrylate, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone, etc.

Examples of thiatonone compounds include thiatonone, 2-methylthiatonone, isopropylthiatonone, 2,4-diethylthiatonone, 2,4-diisopropylthiatonone, 2-chlorothiatonone, etc.

Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzyl dimethyl ketone.

Examples of triazine compounds include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-tolyl)-4,6-bis(trichloromethyl)- s-triazine, 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphthol-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphthol-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-4-bis(trichloromethyl)-6-piperyl-s-triazine, 2-4-bis(trichloromethyl)-6-(4-methoxystyryl)-s-triazine, etc.

Examples of oxime compounds include O-acetylgime compounds, 2-(O-benzoacetylgime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, 1-(O-acetylgime)-1-[9-ethyl-6-(2-methylbenzoacetylgime)-9H-carbazole-3-yl]acetone, O-ethoxycarbonyl-α-oxyamino-1-phenylprop-1-one, etc. Specific examples of O-acetylgimides include 1,2-octanedione, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-but-1-one, 1-(4-phenylthiophenyl)-butane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenylthiophenyl)-octane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenylthiophenyl)-octane-1-one-oxime-O-acetate, and 1-(4-phenylthiophenyl)-but-1-one-oxime-O-acetate.

Examples of amino ketone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, etc.

In addition to the compounds mentioned above, photopolymerization initiators may also include carbazole compounds, diketone compounds, strontium borate compounds, diazo compounds, imidazole compounds, biimidazole compounds, etc.

Photopolymerization initiators can be used with photosensitizers that can induce a chemical reaction by absorbing light, become excited, and then transfer their energy.

Examples of photosensitizers include tetraethylene glycol bis-3-phenylpropionate, pentaerythritol tetra-3-phenylpropionate, dipentaerythritol tetra-3-phenylpropionate, etc.

Examples of thermal polymerization initiators may be peroxides, specifically benzoyl peroxide, dibenzoyl peroxide, lauryl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cyclohexane peroxide, methyl ethyl ketone peroxide, hydrogen peroxides (e.g., tert-butyl hydrogen peroxide, cumene hydrogen peroxide), dicyclohexyl percarbonate, 2,2-azobis(isobutyronitrile), tributyl perbenzoate, etc., such as 2,2'-azobis-2-methylpropionitrile, but not limited to these, and any of those known in the art may be used.

The polymerization initiator may be included in an amount from 0.1% to 5% by weight, for example, from 1% to 4% by weight, based on the total amount of the curable component. When the polymerization initiator is included within this range, excellent reliability can be obtained due to sufficient curing during exposure or thermal curing, and the degradation of transmittance can be prevented due to the non-reactive initiator, thereby preventing the degradation of the optical properties of the quantum dots. Adhesive resin

According to the embodiments, the curable composition may further include adhesive resin.

Adhesive resins may include acrylic resins, calorie resins, epoxy resins, or combinations thereof.

Acrylic resins may be copolymers of a first olefinically unsaturated monomer and a second olefinically unsaturated monomer that can be copolymerized therewith, and may be resins comprising at least one acrylic repeating unit.

Specific examples of acrylic adhesive resins may include polymethyl methacrylate, (meth)acrylic acid/phenyl methacrylate copolymer, (meth)acrylic acid/phenyl methacrylate/styrene copolymer, (meth)acrylic acid/phenyl methacrylate/2-hydroxyethyl methacrylate copolymer, (meth)acrylic acid/phenyl methacrylate/styrene/2-hydroxyethyl methacrylate copolymer, etc., but are not limited to these, and may be used alone or in mixtures of two or more.

The weight average molecular weight of acrylic adhesive resins can be from 5,000 g/mole to 15,000 g/mole. When acrylic adhesive resins have a weight average molecular weight within the aforementioned range, the adhesion to the substrate, physical and chemical properties are improved, and the viscosity is appropriate.

Acrylic resins can have acid values ranging from 80 mg KOH/g to 130 mg KOH/g. When acrylic resins have acid values within this range, pixel patterns can have excellent resolution.

Caldo resins can be used in conventional curable resin (or photosensitive resin) compositions, and can be used, for example, as disclosed in Korean Patent Application No. 10-2018-0067243, but are not limited thereto.

Calotype resins can be prepared, for example, by mixing at least two of the following compounds: fluorene-containing compounds, such as 9,9-bis(4-epoxyethylene methoxyphenyl)fluorene; and acid anhydride compounds, such as phenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, cyclobutanetetracarboxylic dianhydride, perylenetetracarboxylic dianhydride, tetrahydrofurantetracarboxylic dianhydride, and tetrahydrophthalic anhydride. Diol 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 ethyl propylene glycol methyl ester and N-methylpyrrolidone; phosphorus compounds, such as triphenylphosphine; and amine or ammonium salt compounds, such as tetramethylammonium chloride, tetraethylammonium bromide, benzyl diethylamine, triethylamine, tributylamine or benzyl triethylammonium chloride.

The weight-average molecular weight of caloacrylate adhesive resins can be from 500 g/mol to 50,000 g/mol, for example from 1,000 g/mol to 30,000 g/mol. When the weight-average molecular weight of caloacrylate adhesive resins is within the range described above, satisfactory patterns can be formed without residue during the production of the cured layer and without loss of film thickness during the development of solvent-based curable components.

When the adhesive resin is a calorie-based resin, the curable components containing the adhesive resin, specifically the developability of the photosensitive resin components, are improved, and the sensitivity during photocuring is good, thereby improving the fine pattern forming properties.

Epoxy resins can be monomers or oligomers that can be polymerized by heating, and can contain compounds having carbon-carbon unsaturated bonds and carbon-carbon cyclic bonds.

Epoxy resins may include, but are not limited to, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenolic varnish type epoxy resins, cyclic aliphatic epoxy resins, and aliphatic polyglycidyl ethers.

Its currently available products may include: bisphenol epoxy resins, such as YX4000, YX4000H, YL6121H, YL6640 or YL6677 from Yuka Shell Epoxy Co., Ltd.; cresol varnish-type epoxy resins, such as EOCN-102, EOCN-103S, EOCN-104S, EOCN-1020, EOCN-1025 and EOCN-1027 from Nippon Kayaku Co., Ltd., and EPIKOTE 180S75 from Yuka Shell Epoxy Co., Ltd.; and bisphenol A epoxy resins, such as EPIKOTE from Yuka Shell Epoxy Co., Ltd. 1001, 1002, 1003, 1004, 1007, 1009, 1010 and 828; Bisphenol F type epoxy resins, such as EPIKOTE 807 and 834 from Yuxiangke Epoxy Co., Ltd.; Phenolic varnish-type epoxy resins, such as EPIKOTE 152, 154 and 157H65 from Yuxiangke Epoxy Co., Ltd. and EPPN 201 and 202 from Nippon Kayaku Co., Ltd.; Other cyclic aliphatic epoxy resins, such as those from Ciba-Geigy Co., Ltd. A.G.'s CY175, CY177, and CY179; U.C.'s ERL-4234, ERL-4299, ERL-4221, and ERL-4206; Showa Denko K.K.'s Shodyne 509; Ciba-Geigy A.G.'s ARALDITE CY-182, CY-192, and CY-184; Dainippon Ink and Chemicals Inc.'s Epichron 200 and 400; Yuka Shell Epoxy Co., Ltd.'s EPIKOTE 871, 872, and EP1032H60; Celanese Coatings Co., Ltd. ED-5661 and ED-5662 from Yuxiang Shell Epoxy Co., Ltd.; aliphatic polyglycidyl ethers, such as EPIKOTE 190P and 191P from Yuxiang Shell Epoxy Co., Ltd., Epolite 100MF from Kyoesha Yushi Co., Ltd., and Epiol TMP from Nippon Yushi Co., Ltd.

For example, when the curable composition according to the embodiment is a solvent-free curable composition, the content of adhesive resin, based on the total amount of the curable composition, can be from 0.5% to 10% by weight, for example, from 1% to 5% by weight. In this case, the heat resistance and chemical resistance of the solvent-free curable composition can be improved, and the storage stability of the composition can also be improved.

For example, when the curable composition according to the embodiment is a solvent-containing curable composition, the adhesive resin may be included in an amount of 1% to 30% by weight, for example, 3% to 20% by weight, based on the total amount of the curable composition. In this case, pattern properties, heat resistance, and chemical resistance can be improved. Other additives

To improve the stability and dispersibility of quantum dots, the curable composition according to the embodiments may further include a polymerization inhibitor.

Polymerization inhibitors may include, but are not limited to, hydroquinone compounds, catechol compounds, or combinations thereof. If the curable composition according to the embodiments further includes hydroquinone compounds, catechol compounds, or combinations thereof, room-temperature crosslinking can be prevented during exposure after the curable composition is applied.

For example, hydroquinone compounds, catechol compounds, or combinations thereof may be hydroquinone, methyl hydroquinone, methoxy hydroquinone, tributyl hydroquinone, 2,5-di-tert-butyl hydroquinone, 2,5-bis(1,1-dimethylbutyl) hydroquinone, 2,5-bis(1,1,3,3-tetramethylbutyl) hydroquinone, catechol, tributylcatechol, 4-methoxycatechol, gallnutol, 2,6-di-tert-butyl-4-methylphenol, 2-naphthol, tris(N-hydroxy-N-nitrosophenylamino-O,O')aluminum, or combinations thereof, but are not necessarily limited to these.

Hydroquinone compounds, catechol compounds, or combinations thereof may be used in the form of dispersions. The polymerization inhibitor may be included in the total amount of the curable composition in the form of a dispersion from 0.001% to 3% by weight, for example, from 0.01% to 2% by weight. When a polymerization inhibitor is included within this range, aging problems at room temperature can be solved, while simultaneously preventing sensitivity degradation and surface delamination.

In addition, the curable composition according to the embodiments may further include malonic acid; 3-amino-1,2-propanediol; silane coupling agent; leveling agent; fluorine surfactant; or combinations thereof to improve heat resistance and reliability.

For example, the curable composition according to the embodiments may further include a silane coupling agent having reactive substituents such as vinyl, carboxyl, methacryloxy, isocyanate, epoxy, etc., to improve the tight contact properties with the substrate.

Examples of silane coupling agents include trimethoxysilylbenzoic acid, γ-methacrylateoxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-isocyanate propyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, β-epoxycyclohexylethyltrimethoxysilane, etc., and these coupling agents can be used alone or in mixtures of two or more.

Based on 100 parts by weight of curable composition, silane coupling agents can be used in amounts from 0.01 parts by weight to 10 parts by weight. When silane coupling agents are included within the stated range, the tightness of contact, storage capacity, etc., are improved.

In addition, curable components may contain surfactants (such as fluorinated surfactants) as needed to improve coating properties and inhibit spot formation, thereby improving leveling performance.

Fluorinated surfactants can have a low weight-average molecular weight of 4,000 g/mol to 10,000 g/mol, and more specifically 6,000 g/mol to 10,000 g/mol. Furthermore, fluorinated surfactants can have a surface tension of 18 mN/m to 23 mN/m (measured in a 0.1% solution of polyethylene glycol monomethyl ether acetate (PGMEA)). When fluorinated surfactants have a weight-average molecular weight and surface tension within the aforementioned range, leveling performance can be further improved, and when applied as a seam coating for high-speed coating, they provide excellent properties due to the reduced formation of film defects by preventing spot formation and suppressing vapor generation during high-speed coating.

Examples of fluorinated surfactants include BM- ^1000® and BM- ^1100® (BM Chemie Inc.); MEGAFACE F ^142D® , F ^172® , F ^173® and F ^183® (Dainippon Ink Kagaku Kogyo Co., Ltd.); FULORAD FC- ^135® , FULORAD FC- ^170C® , FULORAD FC- ^430® and FULORAD FC- ^431® (Sumitomo 3M Co., Ltd.); SURFLON S- ^112® , SURFLON S- ^113® , SURFLON S- ^131® and SURFLON S-141 ^® and Saffron S- ^145® (ASAHI Glass Co., Ltd.); and SH- ^28PA® , SH-190®, SH- ^193® , SZ- ^6032® and SF- ^8428® (Toray Silicone Co., Ltd.); DIC Co., Ltd.'s F-482, F-484, F-478, F-554, etc.

In addition to fluorinated surfactants, the curable composition according to the embodiments may include silicone surfactants. Specific examples of silicone surfactants may be, but are not limited to, TSF400, TSF401, TSF410, and TSF4440 from Toshiba Silicone Co., Ltd.

Based on 100 parts by weight of curable composition, the surfactant may be included in an amount of 0.01 parts by weight to 5 parts by weight, for example, 0.1 parts by weight to 2 parts by weight. If the surfactant is included within the range, less foreign matter will be generated in the sprayed composition.

Furthermore, unless it would degrade the properties, the curable composition according to the embodiments may contain other additives, such as antioxidants, stabilizers, etc., in predetermined amounts. Solvent

Meanwhile, the curable composition according to the embodiment may further contain solvent.

Solvents may include, for example: alcohols, such as methanol, ethanol, etc.; glycol ethers, such as ethylene glycol methyl ether, ethylene glycol ethyl ether, propylene glycol methyl ether, etc.; solvent acetates, such as methyl solvent acetate, ethyl solvent acetate, diethyl solvent acetate, etc.; carbitol, such as methyl ethyl carbitol, diethyl carbitol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, etc.; propylene glycol alkyl ether acetates, such as propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, etc.; ketones, such as methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, methyl-n-propyl ketone, methyl-n-butyl ketone. Methyl-n-pentyl ketone, 2-heptanone, etc.; saturated aliphatic monocarboxylic acid alkyl esters, such as ethyl acetate, n-butyl acetate, isobutyl acetate, etc.; lactate esters, such as methyl lactate, ethyl lactate, etc.; hydroxyalkyl acetate esters, such as methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, etc.; alkoxyalkyl acetate esters, such as methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, etc.; alkyl 3-hydroxypropionic acid esters, such as methyl 3-hydroxypropionic acid, ethyl 3-hydroxypropionic acid, etc.; alkyl 3-alkoxypropionic acid esters, such as methyl 3-methoxypropionic acid, ethyl 3-methoxypropionic acid, alkyl 3-ethoxypropionic acid, etc. Ethyl hydroxyl propionate, methyl 3-ethoxypropionate, etc.; alkyl 2-hydroxypropionate, such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, propyl 2-hydroxypropionate, etc.; alkyl 2-alkoxypropionate, such as methyl 2-methoxypropionate, ethyl 2-methoxypropionate, ethyl 2-ethoxypropionate, methyl 2-ethoxypropionate, etc.; alkyl 2-hydroxy-2-methylpropionate, such as methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, etc.; alkyl 2-alkoxy-2-methylpropionate, such as methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, etc.; esters, such as ethyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, etc. The following are examples of acetic acid esters: 2-hydroxy-2-methylethyl ester, hydroxyethyl acetate, 2-hydroxy-3-methylmethyl butyrate, etc.; or keto esters, such as ethyl pyruvate, etc. In addition, they may be N-methylformamide, N,N-dimethylformamide, N-methylformaniline, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, benzyl ethyl ether, dihexyl ether, acetoacetone, isophorone, hexanoic acid, octanoic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethyl carbonate, propyl carbonate, phenyl cellosolve acetate, etc., but are not limited to these.

For example, the solvent may be a glycol ether, such as ethylene glycol monoethyl ether, ethylene glycol methyl ethyl ether, etc.; ethylene glycol alkyl ether acetate, such as ethyl solvent acetate, etc.; ester, such as 2-hydroxyethyl propionate, etc.; carbitol, such as diethylene glycol monomethyl ether, etc.; propylene glycol alkyl ether acetate, such as propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, etc.; alcohol, such as ethanol, etc., or combinations thereof.

For example, the solvent may be a polar solvent, including propylene glycol monomethyl ether acetate, dipropylene glycol methyl ether acetate, ethanol, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, 2-butoxyethanol, N-methylpyrrolidone, N-ethylpyrrolidone, propenyl carbonate, γ-butyrolactone, or combinations thereof.

The solvent may be included in an amount of 40% to 80% by weight, for example, 45% to 80% by weight, based on the total amount of the curable composition. When the solvent is within the range, the solvent-based curable composition has a suitable viscosity and therefore exhibits excellent coating properties when coated over a large area by spin coating and slot coating.

Another embodiment provides a cured layer produced using the curable composition and a display device including the cured layer.

One method for producing the cured layer may include: applying the curable composition onto a substrate using an inkjet printing method to form a pattern (S1); and curing the pattern (S2). (S1) Forming the pattern

It is desirable to coat a curable composition onto a substrate in a thickness of 0.5 to 20 micrometers using an inkjet printing method. The inkjet printing method can form a pattern by spraying a single color from each nozzle and thus repeating the spraying an equal number of times as desired, but the pattern can also be formed by spraying the desired number of colors from each inkjet nozzle simultaneously, thereby reducing the number of processes. (S2) Curing

The acquired pattern is cured to obtain pixels. In this document, the curing method can be either thermosetting or photopolymerization. Thermosetting can be performed at a temperature greater than or equal to 100°C, preferably in the range of 100°C to 300°C, and more preferably in the range of 160°C to 250°C. Photopolymerization may involve irradiation with photochemical rays, such as ultraviolet (UV) rays of 190 nm to 450 nm, or for example, 200 nm to 400 nm. Irradiation is performed using light sources such as mercury lamps, halogen lamps, or argon lasers with low, high, or ultra-high pressure. X-rays, electron beams, etc., may also be used as needed.

Other methods for producing cured layers may include using curable components to produce cured layers via the following photolithography methods: (1) Coating and film formation

A curable composition is coated onto a pre-treated substrate to a desired thickness, such as 2 to 10 micrometers, using methods such as rotary coating, slit coating, roller coating, screen printing, or a coating applicator. The coated substrate is then heated at 70°C to 90°C for 1 to 10 minutes to remove the solvent and form a film. (2) Exposure

After placing a mask of a predetermined shape, the resulting film is irradiated with photochemical rays, such as UV rays of 190 nm to 450 nm or 200 nm to 400 nm, to form the desired pattern. Irradiation is performed using light sources such as mercury lamps, halogen lamps, or argon lasers with low, high, or ultra-high pressure. X-rays, electron beams, etc., may also be used as needed.

When using a high-pressure mercury lamp, the exposure process uses a photon dose of, for example, 500 mJ/cm² or less (using a 365 nm sensor). However, this photon dose can vary depending on the type of each component of the curable composition, its blending ratio, and the dry film thickness. (3) Development

After the exposure process, an alkaline aqueous solution is used to dissolve and remove the excess material (excluding the exposed areas) to develop the exposed film, forming an image pattern. In other words, when an alkaline developing solution is used, the unexposed areas are dissolved, forming an image color filter pattern. (4) Post-processing

The developed image pattern can be heated again or irradiated with photochemical rays to cure it, so as to achieve excellent qualities in terms of heat resistance, light resistance, tight contact properties, crack resistance, chemical resistance, high strength, and storage stability.

The invention is illustrated in more detail below with reference to examples. However, these examples should not be construed in any way as limiting the scope of the invention. Preparation of polymerizable compounds Example 1

1 mole of 4,4'-isopropyldicyclohexanol was dissolved in THF (tetrahydrofuran), and 2.2 moles of sodium hydroxide were added at 0°C, followed by stirring for 30 minutes. Subsequently, 2.2 moles of allyl bromide were added, and the mixture was stirred under reflux at room temperature for 90 minutes, followed by additional stirring for 10 hours to complete the reaction. The resulting product was treated with an aqueous solution of _NH4Cl and ethyl acetate, and then distilled under reduced pressure to obtain intermediate A. The intermediate was dissolved in chloroform, and 3-chloroperoxybenzoic acid was added at 0°C. The mixture was then stirred for 2 hours to complete the reaction. The resulting product was then treated with 10% NaOH aqueous solution and MC (dichloromethane) to obtain intermediate B.

Subsequently, intermediate product B with a molar ratio of 1:1 and 4,4'-isopropyldicyclohexanol were added to PGMEA, and an additional 0.5 equivalent of TBAB (tetrabutylammonium bromide) was added. The mixture was then stirred at 100°C for 24 hours and washed with methanol and water. The resulting precipitate was dried to obtain intermediate product C-1.

Then, intermediate C-1 was dissolved in toluene and reacted with 2.5 equivalents of methacrylic acid and 2.5 equivalents of methanesulfonic acid at 120°C for 5 hours, thereby finally obtaining the compound represented by formula 3-1. [Formula 3-1] Preparation Example 2

Intermediate product C-2 was obtained in the same manner as in Preparation Example 1, except that 2,2-bis(4-hydroxycyclohexyl)propane was used instead of 4,4'-isopropyldicyclohexanol.

Intermediate product C-2 was dissolved in toluene and then reacted with 2.5 equivalents of NaOH and 2.5 equivalents of epichlorohydrin at 60°C for 5 hours, thereby finally obtaining the compound represented by chemical formula 3-2. [Chemical formula 3-2] Preparation Example 3

One mole of OXT-101 (Toagosei Co., Ltd.) and 1.1 moles of toluenesulfonyl chloride were dissolved in THF, and 1.5 equivalents of NaOH were slowly added to the solution, followed by stirring at room temperature for 4 hours. The resulting product was treated with an aqueous ammonium chloride solution and MC, and then distilled under reduced pressure to obtain intermediate D. Intermediate D in the same mole ratio and intermediate C-1 according to Preparation Example 1 were dissolved in toluene, and 1.5 equivalents of NaOH were added to the solution, followed by reaction for 5 hours, thereby finally obtaining the compound represented by chemical formula 3-3. [Chemical Formula 3-3] Preparation Example 4

Intermediate product C-1 from Preparation Example 1 was dissolved in THF, and 2,2 moles of sodium hydroxide were added at 0°C, followed by stirring for 30 minutes. Subsequently, 2,2 moles of allyl bromide were added, and the mixture was stirred at room temperature for 90 minutes, followed by additional stirring under reflux for 10 hours, thereby obtaining the compound represented by Formula 3-4. [Formula 3-4] Preparation Example 5

100 g of 1,9-nonanediol was dissolved in 100 mL of toluene, and then reacted with 135 g of acrylic acid and 8.2 g of methanesulfonic acid at 120 °C for 5 hours to obtain the compound represented by chemical formula 4-3. [Chemical formula 4-3] Comparative preparation example 1

The compound represented by formula 4-2 was prepared in the same manner as in Preparation Example 5, except that 1,6-hexanediol was used instead of 1,9-nonanediol. [Formula 4-2] Preparation of surface-modified quantum dot dispersions - Example 6

After placing a magnetic rod in a three-necked round-bottom flask, a green quantum dot dispersion solution (InP/ZnSe/ZnS, Hansol Chemical; quantum dot solid content 23 wt%) was added. Subsequently, a compound (ligand) represented by the chemical formula Q was added, and the mixture was stirred at 80°C under a nitrogen atmosphere. Upon completion of the reaction, after cooling to room temperature, the quantum dot reaction solution was added to cyclohexane to capture the precipitate. The precipitate was separated from the cyclohexane by centrifugation and then thoroughly dried in a vacuum oven for 24 hours, thereby obtaining surface-modified quantum dots.

Surface-modified green quantum dots were stirred together with polymerizable compounds for 12 hours to obtain a surface-modified quantum dot dispersion (QD solids content: 23% by weight).

*Synthesis of the compound represented by chemical formula Q: 100 g of PH-4 (Hannong Chemicals Inc.) was placed in a two-necked round-bottom flask and then completely dissolved in 300 mL of THF. Then, 15.4 g of NaOH and 100 mL of water were added at 0°C and dissolved completely until a clear solution was obtained. A solution prepared by dissolving 73 g of p-toluenesulfonyl chloride in 100 mL of THF was slowly added to the solution at 0°C. The addition was carried out for 1 hour, and then the resulting mixture was stirred at room temperature for 12 hours. When the reaction was complete, excess dichloromethane was added, and the mixture was stirred. NaHCO3 was then added. ₃ saturated solutions were used for extraction, titration, and water removal. After solvent removal, the residue was dried in a drying oven for 24 hours. 50 g of the dried product was added to a two-necked round-bottom flask and stirred thoroughly with 300 mL of ethanol. Subsequently, 27 g of thiourea was added and dispersed, and then refluxed at 80 °C for 12 hours. Then, the solution was injected with... An aqueous solution was prepared by dissolving 4.4 g of NaOH in 20 mL of water and stirring for 5 hours. Excess dichloromethane was then added, followed by stirring and the addition of hydrochloric acid solution. Extraction, titration, water removal, and solvent removal were then performed sequentially. The solution was then dried in a vacuum oven for 24 hours to obtain the compound represented by chemical formula Q. (Preparation of curable components) Examples 1 to 11 and Comparative Examples 1 and 2

Curable compositions of Examples 1 to 11 and Comparative Examples 1 and 2 were prepared using the following components, such that each composition is shown in Tables 1 and 2.

Specifically, the quantum dot dispersion was weighed and then diluted by mixing with a polymerizable compound, a polymerization inhibitor was added, and the mixture was stirred for 5 minutes. Subsequently, a photoinitiator and a light diffusing agent were added. The corresponding composition was then stirred for 1 hour to prepare a curable composition. (A) Surface-modified green quantum dot dispersion prepared in Example 6 (B) Polymerizable compound (B-1) Compound of Preparation Example 1 (B-2) Compound of Preparation Example 2 (B-3) Compound of Preparation Example 3 (B-4) Compound of Preparation Example 4 (B-5) Compound of Preparation Example 5 (B-6) Comparative compound of Preparation Example 1 (B-7) Compound represented by chemical formula E (YD-128, Kukdo Chemical) [Chemical Formula E] (C) Photopolymerization initiator TPO-L (Polynetron Co., Ltd.) (D) Light diffusing agent titanium dioxide dispersion ( _TiO2 solid content: 20% by weight, average particle size: 200 nm, Dito Technology Co., Ltd.) (Table 1) (Unit: % by weight) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 (A) Quantum dot dispersion 41 41 41 41 41 41 41 41 41 41 41 (B) Polymerizable compounds B-1 53.5 - - - 18.2 - - - 21.4 26.75 32.1 B-2 - 53.5 - - - 18.2 - - - - - B-3 - - 53.5 - - - 18.2 - - - - B-4 - - - 53.5 - - - 18.2 - - - B-5 - - - - 35.3 35.3 35.3 35.3 32.1 26.75 21.4 (C) Photopolymerization initiator 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 (D) Light diffusing agent 4 4 4 4 4 4 4 4 4 4 4 Total 100 100 100 100 100 100 100 100 100 100 100 (Table 2) (Unit: weight %) Comparative example 1 Comparative example 2 (A) Quantum dot dispersion 41 41 (B) Polymerizable compounds B-6 53.5 - B-7 - 53.5 (C) Photopolymerization initiator 1.5 1.5 (D) Light diffusing agent 4 4 Total 100 100 Evaluation: Assessment of the optical properties and diffuse reflectance of the curable composition.

Each of the curable compositions of Examples 1 to 11, and Comparative Examples 1 and 2, was formed into a 2 cm × 2 cm single-film sample. The luminous efficacy over time (after curing) was then measured using a blue light-emitting diode (LED) planar light source under a blue 20,000 nit light source condition, and the results are shown in Table 3. The luminous efficacy of the single-film samples was measured using an integrating sphere apparatus (QE-2100, Otsuka Electronics Co., Ltd.) and an in-line luminance meter (M7000, McScience Co., Ltd.).

Light retention rate refers to the luminous efficiency after 1000 hours. (Table 3) Initial luminous efficiency (%) Light retention rate (%) Example 1 32.1 90 Example 2 32.7 91 Example 3 32.1 90 Example 4 32.5 91 Example 5 33.1 95 Example 6 33.7 98 Example 7 33.1 95 Example 8 33.6 97 Example 9 33.1 95 Example 10 33.0 94 Example 11 32.7 92 Comparative example 1 31.5 88 Comparative example 2 30.4 87

Referring to Table 3, compared with the curable compositions of Comparative Examples 1 and 2, the curable compositions of Examples 1 to 11 exhibit improved optical properties due to their high quantum efficiency after curing, while maintaining a high light retention rate.

Although the invention has been described in conjunction with exemplary embodiments now considered practical, it should be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended claims. Therefore, the foregoing embodiments should be understood as exemplary and not as limiting the invention in any way.

without

without

Claims (18)

A curable composition comprising: (A) quantum dots; and (B) a polymerizable compound, wherein the polymerizable compound comprises a first polymerizable compound comprising substituted or unsubstituted C3 to C20 cycloalkyl groups and polymerizable functional groups, and the polymerizable functional groups comprising (meth)acrylate groups, epoxy groups, oxocyclobutane groups, vinyl groups, or combinations thereof, wherein the first polymerizable compound comprises a repeating unit represented by Formula 1: [Formula 1] In Formula 1, ^L1 , ^L2 and ^L4 are each independently a single-bonded or substituted or unsubstituted C1 to C20 alkyl group, and ^L3 and ^L5 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkyl group, or a substituted or unsubstituted C3 to C20 cycloalkyl group, with the restriction that at least one of ^L3 and ^L5 must be a substituted or unsubstituted C3 to C20 cycloalkyl group. The curable composition as claimed in claim 1, wherein the first polymerizable compound further comprises a linker represented by formula 2: [Formula 2] In Formula 2, ^L7 is a single-bonded or substituted or unsubstituted C1 to C20 alkyl group, and ^L6 and ^L8 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkyl group, or a substituted or unsubstituted C3 to C20 cycloalkyl group, with the restriction that at least one of ^L6 and ^L8 must be a substituted or unsubstituted C3 to C20 cycloalkyl group. The curable composition as claimed in claim 1, wherein the first polymerizable compound comprises (meth)acrylate, epoxy, oxocyclobutane, vinyl, or combinations thereof at both ends. The curable composition as claimed in claim 1, wherein the first polymerizable compound is represented by chemical formula 3: [chemical formula 3] In Formula 3, ^R1 and ^R2 are each independently represented by any one of Formulas R-1 to R-4; ^L1 , ^L2 , ^L4 , and ^L7 are each independently a single-bonded or substituted or unsubstituted C1 to C20 alkylene group; ^L3 , ^L5 , ^L6 , and ^L8 are each independently a single-bonded, substituted or unsubstituted C1 to C20 alkylene group, or a substituted or unsubstituted C3 to C20 cycloalkylene group; the restriction is that at least one of ^L3 and ^L5 must be a substituted or unsubstituted C3 to C20 cycloalkylene group, and at least one of ^L6 and ^L8 must be a substituted or unsubstituted C3 to C20 cycloalkylene group; and n is an integer from 0 to 100. [Formula R-1] [Chemical formula R-2] [Chemical formula R-3] [Chemical formula R-4] In the chemical formulas R-1 to R-4, ^R3 and ^R4 are each independently a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group, and ^L9 to ^L11 are each independently a single bond or a substituted or unsubstituted C1 to C20 alkyl group. The curable composition as described in claim 4, wherein in formula 1, ^L3 , ^L5 , ^L6 and ^L8 are all substituted or unsubstituted C3 to C20 cycloalkyl groups. The curable composition as claimed in claim 1, wherein the polymerizable compound further includes a second polymerizable compound having a structure different from that of the first polymerizable compound. The curable composition as described in claim 6, wherein the second polymerizable compound comprises a compound represented by formula 4: [Formula 4] In Formula 4, ^L12 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or an ether group (*-O-*), ^L13 and ^L14 are each independently a single bond or a substituted or unsubstituted C1 to C10 alkyl group, and ^R5 and ^R6 are each independently a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group. The curable composition as described in claim 6, wherein the first polymerizable compound and the second polymerizable compound are contained in a weight ratio of 1:9 to 9:1. The curable composition as described in claim 1, wherein the curable composition is a solvent-free curable composition. The curable composition as claimed in claim 9, wherein, based on the total amount of the solvent-free curable composition, the solvent-free curable composition comprises: 5% to 60% by weight of the quantum dots; and 40% to 95% by weight of the polymerizable compound. The curable composition as claimed in claim 1, wherein the curable composition further comprises a light diffusing agent, wherein the light diffusing agent comprises barium sulfate, calcium carbonate, titanium dioxide, zirconium oxide, or a combination thereof. The curable composition as described in claim 1, wherein the quantum dots comprise cadmium-free luminescent materials. The curable composition as claimed in claim 12, wherein the quantum dots have an InP/ZnS core/shell structure or an InP/ZnSe/ZnS core/first shell/second shell structure. The curable composition as claimed in claim 1, wherein the quantum dot comprises a core containing silver (Ag), indium (In), gallium (Ga) and sulfur (S) and a shell containing at least two of the groups selected from Ag, Ga, Zn and S. The curable composition as claimed in claim 1, wherein the curable composition further comprises a solvent, and the curable composition comprises, by total weight of the curable composition, 1% to 40% by weight of the quantum dots; 1% to 20% by weight of the polymerizable compound; and 40% to 80% by weight of the solvent. The curable composition as claimed in claim 1, wherein the curable composition has a viscosity of 10 centipoise to 50,000 centipoise at 25°C. A cured layer, manufactured using a curable composition as described in any one of claims 1 to 16. A display device comprising a cured layer as described in claim 17.