KR20210121917A - Light Conversion Ink Composition, Color Filter and Display Device - Google Patents

Abstract

The present invention provides a light conversion ink composition, a color filter formed using the same, and an image display device having the color filter. The light conversion ink composition comprises a quantum dot, a curable monomer and a nonionic photoacid generator, wherein the curable monomer has a viscosity of 30 cP or less at 25℃. The light conversion ink composition according to the present invention has excellent optical properties and exhibits excellent long-term reliability in a high-humidity state because the deterioration of optical properties does not occur in a UV processing or post-bake processing. Therefore, the light conversion ink composition can be effectively used in manufacturing a color filter by an inkjet printing method.

Description

Light Conversion Ink Composition, Color Filter and Display Device {Light Conversion Ink Composition, Color Filter and Display Device}

The present invention relates to a light conversion ink composition, a color filter, and an image display device, and more particularly, a light having excellent optical properties and long-term reliability in a high humidity state because optical properties deterioration does not occur in the UV or post-baking process. It relates to a conversion ink composition, a color filter formed using the same, and an image display device having the color filter.

A color filter is a thin film type optical component that extracts three colors of red, green, and blue from white light and makes it possible in minute pixel units.

In this regard, recently, in order to exhibit high color reproducibility as well as excellent pattern characteristics, a method for manufacturing a color filter using a self-luminous photosensitive resin composition including quantum dots has been proposed.

A photolithography method using a conventionally known self-luminous photosensitive resin composition containing quantum dots is a method of forming a color filter through coating, exposure, development and curing. For each color, coating, exposure, development, and curing processes are required for each color, increasing the manufacturing process, time and cost, and increasing control factors between processes, which may make it difficult to manage yield.

Accordingly, instead of the photolithography method, an inkjet method capable of coloring a plurality of colors including red, green, and blue at once has been proposed.

Korean Patent Registration No. 10-1475520 discloses that quantum dots can be discharged by the inkjet method, including quantum dots, solvents, and high-viscosity polymer additives, and the concentration of quantum dots can be freely controlled, and the amount of loading of quantum dots can be reduced. A quantum dot ink composition for inkjet printing that can be used is disclosed.

However, the quantum dot ink composition has a problem of poor reliability when the coating film is exposed to high humidity for a long period of time because a separate curing accelerating component for accelerating the curing of the coating film is not added. In addition, when a conventional photopolymerization initiator is added to solve this problem, radicals generated in the UV or post-baking process come into contact with the QD surface to cause surface oxidation and eventually decrease the optical properties of the quantum dots. characteristics will decrease.

Therefore, there is an urgent need for the development of a photoconversion ink composition having excellent optical properties and long-term reliability in a high humidity state because deterioration in optical properties does not occur in the UV or post-baking process.

Republic of Korea Patent No. 10-1475520

One object of the present invention is It is to provide an optical conversion ink composition excellent in optical properties and long-term reliability in a high humidity state because optical properties deterioration does not occur in the UV or post-baking process.

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

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

Another object of the present invention is to provide an image display device including the color filter.

On the other hand, the present invention provides a photoconversion ink composition comprising quantum dots, a curable monomer and a nonionic photoacid generator, wherein the curable monomer has a viscosity of 30 cP or less at 25°C.

In an embodiment of the present invention, the curable monomer may include a monofunctional (meth)acrylate or polyfunctional (meth)acrylate having a viscosity of 30 cP or less at 25°C.

In one embodiment of the present invention, the nonionic photoacid generator may generate an acid compound represented by the following Chemical Formula 1.

[Formula 1]

In the above formula, R is a C ₁ -C ₄ aliphatic hydrocarbon group.

In one embodiment of the present invention, the nonionic photoacid generator may include at least one of compounds represented by the following Chemical Formulas 2 to 3.

[Formula 2]

[Formula 3]

In the above formula, R is a C ₁ -C ₄ aliphatic hydrocarbon group.

In one embodiment of the present invention, the nonionic photoacid generator may be included in an amount of 0.1 to 10% by weight based on 100% by weight of the total composition.

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

The light conversion ink composition according to an embodiment of the present invention may include a solvent in an amount of 1 wt% or less.

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

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

On the other hand, the present invention provides an image display device provided with the color filter.

The photoconversion ink composition according to the present invention has excellent optical properties because no deterioration of optical properties occurs in the UV or post-baking process, and has excellent long-term reliability in a high-humidity state. In addition, the photoconversion ink composition according to the present invention can implement a low viscosity even without substantially including a solvent and has excellent dispersibility of quantum dots. Therefore, the photoconversion ink composition according to the present invention can be effectively used for manufacturing a color filter by an inkjet printing method.

Hereinafter, the present invention will be described in more detail.

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

In the present invention, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

One embodiment of the present invention includes a quantum dot (A), a curable monomer (B) and a nonionic photoacid generator (C), wherein the curable monomer (B) is a low-viscosity curable having a viscosity of 30 cP or less at 25°C It relates to a photoconversion ink composition comprising a monomer.

Quantum dots (A)

In one embodiment of the present invention, the quantum dots have a ligand layer on the surface.

For example, the quantum dot may have a ligand layer including a compound represented by the following formula (4) on the surface.

[Formula 4]

In the above formula,

R' and R'' are each independently a hydrogen atom; carboxyl group; phenyl group; Or a thiol group substituted or unsubstituted C ₁ -C ₂₀ Alkyl group,

R' and R" are not simultaneously a hydrogen atom; a phenyl group; or an unsubstituted C ₁ -C ₂₀ alkyl group,

n is an integer from 1 to 20;

As used herein, the C ₁ -C ₂₀ alkyl group refers to a linear or branched monovalent hydrocarbon having 1 to 20 carbon atoms, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, Isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 2-methylpentyl , 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2- propylpentyl, n-nonyl, 2,2-dimethylheptyl, n-decyl, and the like.

In one embodiment of the present invention, specific examples of the compound represented by Formula 4 include 2-(2-methoxyethoxy)acetic acid (WAKO), 2-[2-(2-methoxyethoxy) Toxy]acetic acid (WAKO), {2-[2-(carboxymethoxy)ethoxy]ethoxy}acetic acid (WAKO), 2-[2-(benzyloxy)ethoxy]acetic acid, (2-(carboxy) methoxy)ethoxy)acetic acid (WAKO), (2-butoxyethoxy)acetic acid (WAKO), carboxy-EG6-undecanethiol, and the like, but are not limited thereto.

Since the quantum dot includes a polyethylene glycol-based ligand represented by Formula 4, the quantum dot has excellent optical properties, and can exhibit good dispersion properties only with a curable monomer described below without a solvent.

The compound represented by Formula 4 may cover the surface of 5% or more of the total surface area of the quantum dots.

In this case, the content of the compound represented by Chemical Formula 4 may be 0.1 to 10 moles based on 1 mole of quantum dots.

The ligand layer including the compound represented by Formula 4 may have a thickness of 0.1 nm to 2 nm, for example, a thickness of 0.5 nm to 1.5 nm.

In one embodiment of the present invention, the quantum dots may refer to a nano-sized semiconductor material. Atoms form molecules, and molecules form aggregates of small molecules called clusters to form nanoparticles. When these nanoparticles have semiconductor properties, they are called quantum dots. When the quantum dot receives energy from the outside and reaches an excited state, the quantum dot emits energy according to its own corresponding energy bandgap. For example, the light conversion ink composition of the present invention includes such quantum dots, it is possible to convert the incident blue light into green light and red light.

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

The non-cadmium-based quantum dot is not particularly limited as long as it is a quantum dot particle capable of emitting light by stimulation by light. For example, a group II-VI semiconductor compound; III-V semiconductor compounds; group IV-VI semiconductor compounds; Group IV element or a compound containing the same; And may be selected from the group consisting of combinations thereof, and these may be used alone or in mixture of two or more.

Specifically, the group II-VI semiconductor compound may include a binary compound selected from the group consisting of ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; a ternary compound selected from the group consisting of ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and HgZnSeS, HgZnSeTe, HgZnSTe, and a quaternary compound selected from the group consisting of mixtures thereof, but is not limited thereto.

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

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

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

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

Specifically, in the double structure of the core-shell, the material constituting each core and the shell may be made of the different semiconductor compounds mentioned above. For example, the core may be GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP , InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb comprising at least one selected from the group consisting of , The shell may include one or more selected from the group consisting of ZnSe, ZnS and ZnTe, but is not limited thereto.

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

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

The wet chemical process is a method of growing particles by adding a precursor material to an organic solvent. When the crystal is grown, the organic solvent is naturally coordinated on the surface of the quantum dot crystal and acts as a dispersant to control the growth of the crystal. Since the growth of particles can be controlled, it is preferable to use the wet chemical process to prepare the quantum dots.

In the case of producing quantum dots by a wet chemical process, an organic ligand is used to prevent aggregation of quantum dots and to control the particle size of quantum dots to a nano level. As such an organic ligand, oleic acid may be generally used.

In one embodiment of the present invention, the oleic acid used in the manufacturing process of the quantum dots is replaced by the ligand exchange method by the polyethylene glycol-based compound of Formula 4 above.

The ligand exchange is an original organic ligand, that is, a dispersion containing quantum dots having oleic acid, an organic ligand to be exchanged, that is, a polyethylene glycol compound of Formula 4 is added, and the mixture is stirred at room temperature to 200° C. for 30 minutes to 3 hours. to obtain a quantum dot to which the polyethylene glycol-based compound of Formula 4 is bound. If necessary, the process of separating and purifying the quantum dots to which the polyethylene glycol-based compound of Formula 4 is bound may be additionally performed.

The quantum dots may be included in an amount of 1 to 40% by weight, preferably 2 to 30% by weight, based on 100% by weight of the total light conversion ink composition. When the quantum dots are included within the above range, there is an advantage in that the luminous efficiency is excellent and the reliability of the coating layer is excellent. When the quantum dots are included in less than the above range, the light conversion efficiency of green light and red light may be insufficient, and when the quantum dot exceeds the above range, the emission of blue light is relatively reduced, thereby causing a problem in color reproducibility.

Curable monomer (B)

In one embodiment of the present invention, the curable monomer (B) includes a curable monomer having a viscosity of 30 cP or less at 25° C., for example, a viscosity of 5 to 30 cP, that is, a low-viscosity curable monomer.

The light conversion ink composition according to an embodiment of the present invention may exhibit a low viscosity suitable for inkjet printing while having good surface curability and coating film properties by including a low-viscosity curable monomer as a curable monomer.

The low-viscosity curable monomer may include a monofunctional (meth)acrylate or polyfunctional (meth)acrylate having a viscosity of 30 cP or less at 25°C.

For example, as the low-viscosity curable monomer, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, lauryl (meth) acrylate, stearyl monofunctional alkyl (meth)acrylates such as (meth)acrylate; Bifunctional (meth)acrylic having an alkylene chain, such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and 1,10-decanediol diacrylate rate; 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, 2-hydroxy-3-phenoxyethyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol monohydroxypenta (meth)acrylate which has hydroxyl groups, such as (meth)acrylate and 2-hydroxypropyl (meth)acrylate; isobornyl (meth)acrylate; acryloylmorpholine; Glycidyl methacrylate and the like can be used. These can be used individually or in combination of 2 or more types.

The curable monomer (B) may be included in an amount of 20 to 90% by weight, preferably 30 to 80% by weight, based on 100% by weight of the total weight of the light conversion ink composition. When the curable monomer is included within the above range, there is a desirable advantage in terms of strength or smoothness of the pixel portion. When the curable monomer is included in less than the above range, the strength of the pixel portion may be somewhat reduced, and if the curable monomer is included in more than the above range, smoothness may be slightly reduced, so it is preferably included in the above range.

Nonionic photoacid generator (C)

In one embodiment of the present invention, the nonionic photoacid generator (C) is a compound capable of generating an acid by the action of light or radiation, and does not cause surface oxidation of the quantum dots, so that the optical properties of the quantum dots will not deteriorate. can

The nonionic photoacid generator may be one that generates an acid compound represented by the following formula (1).

[Formula 1]

In the above formula, R is a C ₁ -C ₄ aliphatic hydrocarbon group.

As used herein, the C ₁ -C ₄ aliphatic hydrocarbon group is a linear or branched monovalent hydrocarbon composed of 1 to 4 carbon atoms, and is composed of only a carbon-carbon single bond, or at least one carbon-carbon double bond or triple bond. It is a concept that includes having For example, a C ₁ -C ₄ aliphatic hydrocarbon group is methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, ethyleneyl, propenyl, butenyl, acetylenyl, pro Finyl, butynyl, and the like are included, but are not limited thereto.

In one embodiment of the present invention, the nonionic photoacid generator may include at least one of compounds represented by the following Chemical Formulas 2 to 3.

[Formula 2]

[Formula 3]

In the above formula, R is a C ₁ -C ₄ aliphatic hydrocarbon group.

In one embodiment of the present invention, the nonionic photo-acid generator may include one or more of the following compounds of Chemical Formulas 5 to 8.

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In one embodiment of the present invention, the nonionic photoacid generator may be included in an amount of 0.1 to 10% by weight, preferably 0.1 to 5% by weight, based on 100% by weight of the total composition. When the nonionic photo-acid generator is included in an amount of less than 0.1% by weight, the required exposure amount for pattern formation may increase and thus sensitivity may decrease, and if included in an amount of more than 10% by weight, surface roughness may increase.

Scattering particles (D)

The light conversion ink composition according to an embodiment of the present invention may further include scattering particles (D).

The scattering particles serve to increase the overall light efficiency by increasing the path of light emitted from the quantum dots.

As the scattering particles, a conventional inorganic material may be used, and a metal oxide may be preferably used.

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

Specifically, Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , ITO, IZO, ATO, ZnO-Al, Nb ₂ O ₃ , SnO, MgO and One selected from the group consisting of combinations thereof is possible. If necessary, a material surface-treated with a compound having an unsaturated bond such as acrylate may be used.

The scattering particles may have an average particle diameter of 50 to 1000 nm, preferably in the range of 100 to 500 nm, more preferably in the range of 150 to 300 nm. At this time, if the particle size is too small, a sufficient scattering effect of light emitted from the quantum dots cannot be expected. Adjust and use.

In the present invention, the average particle diameter may be a number average particle diameter, and for example, it can be obtained from an image observed by a field emission scanning electron microscope (FE-SEM) or a transmission electron microscope (TEM). Specifically, it is possible to obtain a value obtained by extracting several samples from an observation image of FE-SEM or TEM, measuring the diameters of these samples, and arithmetic average.

The scattering particles may be included in an amount of 0.5 to 20% by weight, preferably 1 to 15% by weight, based on 100% by weight of the total weight of the light conversion ink composition. When the scattering particles are included within the above range, the effect of increasing the luminescence intensity can be maximized, and it is preferable. The transmittance of the irradiated light may be lowered, which may cause a problem in luminous efficiency.

Photoinitiator (E)

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

In one embodiment of the present invention, the photopolymerization initiator (E) may be used without particularly limiting the type as long as it can polymerize the curable monomer. In particular, the photopolymerization initiator is an acetophenone-based compound, a benzophenone-based compound, a triazine-based compound, a biimidazole-based compound, an oxime-based compound, and thioxic acid in terms of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc. It is preferable to use a tone type compound, an acylphosphine oxide type compound, etc., and an acylphosphine oxide type compound is especially preferable. These photoinitiators can be used individually or in combination of 2 or more types.

Specific examples of the acetophenone-based compound include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 2-hydroxy-1-[4-(2-hydroxyl) oxyethoxy)phenyl]-2-methylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one; 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane-1 -one, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, etc. are mentioned.

Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3',4,4'-tetra( tert-butylperoxycarbonyl)benzophenone and 2,4,6-trimethylbenzophenone.

Specific examples of the triazine-based compound include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6 -(4-Methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine, 2,4-bis (trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2- yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine , 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl )-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine etc. are mentioned.

Specific examples of the biimidazole-based compound include 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(2,3- Dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetra(alkoxyphenyl)biimi Dazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetra(trialkoxyphenyl)biimidazole, 2,2-bis(2,6-dichlorophenyl)-4 ,4',5,5'-tetraphenyl-1,2'-biimidazole or a biimidazole compound in which the phenyl group at the 4,4',5,5' position is substituted with a carboalkoxy group; have. Among them, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(2,3-dichlorophenyl)-4,4' ,5,5'-tetraphenylbiimidazole, 2,2-bis(2,6-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole is preferred used

Specific examples of the oxime-based compound include o-ethoxycarbonyl-α-oxyimino-1-phenylpropan-1-one, and commercially available products include Irgacure OXE 01 and OXE 02 manufactured by BASF.

Examples of the thioxanthone-based compound include 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and the like. There is this.

Examples of the acylphosphine oxide-based compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethe). oxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide etc. are mentioned. As a commercial item, Lucirin TPO by BASF Corporation, Igacure-819 by Ciba Specialty Chemicals, etc. are mentioned.

The photopolymerization initiator may be included in an amount of 50% by weight or less based on 100% by weight of the total amount of the nonionic photoacid generator and the photopolymerization initiator. When the photopolymerization initiator is included in an amount of more than 50% by weight based on 100% by weight of the total amount of the nonionic photoacid generator and the photopolymerization initiator, it may cause surface oxidation of the quantum dots, thereby reducing the optical properties of the quantum dots.

The photopolymerization initiator may be included in an amount of 0.01 to 20% by weight, preferably 0.5 to 15% by weight, based on 100% by weight of the total light conversion ink composition. When the photopolymerization initiator is included in the above range, it is preferable because the photoconversion ink composition is highly sensitive and the exposure time is shortened, so that productivity can be improved. In addition, there is an advantage in that the strength of the pixel portion formed by using the photoconversion ink composition according to the present invention and smoothness on the surface of the pixel portion are improved.

The photopolymerization initiator (E) may further include a photopolymerization initiator auxiliary (e1) in order to improve the sensitivity of the photoconversion ink composition according to the present invention. When the photopolymerization initiation adjuvant is included, the sensitivity is further increased, thereby improving productivity.

The photopolymerization initiation adjuvant (e1) may be, for example, at least one compound selected from the group consisting of an amine compound, a carboxylic acid compound, and an organic sulfur compound having a thiol group, but is not limited thereto.

The said photoinitiation adjuvant (e1) can be added and used suitably in the range which does not impair the effect of this invention.

Additive (F)

The light conversion ink composition according to an embodiment of the present invention may further include an additive (F) in addition to the above-described components.

The additives may be surfactants, antioxidants, thermal acid generators, dispersants, fillers, curing agents, adhesion promoters, and the like, and these may be used alone or in combination of two or more.

The surfactant may be used to further improve the film-forming property of the light conversion ink composition of the present invention, and a fluorine-based surfactant, a silicone-based surfactant, or the like may be preferably used.

The silicone-based surfactants include, for example, DC3PA, DC7PA, SH11PA, SH21PA, and SH8400 manufactured by Dow Corning Toray Silicone as commercially available products, and TSF-4440, TSF-4300, TSF-4445, TSF-4446, and TSF- by GE Toshiba Silicone. 4460, TSF-4452, and the like. The fluorine-based surfactant is, for example, a commercially available product, such as Megapac F-470, F-471, F-475, F-482, F-489, F-554 of Dainippon Ink Chemical Industry Co., Ltd.

Each of the surfactants exemplified above may be used alone or in combination of two or more.

The additive may be used in an amount of 0.05 to 10% by weight, specifically 0.1 to 10% by weight, and more specifically 0.1 to 5% by weight based on 100% by weight of the total light conversion ink composition, but is not limited thereto.

The photoconversion ink composition according to an embodiment of the present invention does not substantially include a solvent, and even if included, it may be included in an amount of 1 wt% or less based on 100 wt% of the total photoconversion ink composition. Although the light conversion ink composition according to an embodiment of the present invention is a solvent-free type that does not contain a solvent or a low-solvent type containing a very small amount of 1% by weight or less, the optical properties and dispersibility of quantum dots are excellent, and low viscosity can be realized.

In addition, the light conversion ink composition according to an embodiment of the present invention does not substantially include a resin component, even if included may be included within 0.5% by weight based on 100% by weight of the total light conversion ink composition. The light conversion ink composition according to an embodiment of the present invention does not include a resin component, and thus can realize a low viscosity and thus has excellent nozzle jetting properties of the ink.

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

In addition, one embodiment of the present invention relates to a color filter including the above-described light conversion pixel.

The method for forming a pattern of a light conversion ink composition according to the present invention comprises the steps of applying the above-described light conversion ink composition to a predetermined area by an inkjet method and curing the applied light conversion ink composition.

First, the photoconversion ink composition of the present invention is injected into an inkjet injector and printed on a predetermined area of the substrate.

The substrate is not limited, and examples include a substrate with a flat surface, such as a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, an aromatic polyamide substrate, a polyamideimide substrate, a polyimide substrate, an Al substrate, a GaAs substrate, etc. can These substrates can be subjected to pretreatment such as chemical treatment with a chemical such as a silane coupling agent, plasma treatment, ion plating treatment, sputtering treatment, gas phase reaction treatment, vacuum deposition treatment, and the like. When a silicon substrate or the like is used as the substrate, a charge coupled device (CCD), a thin film transistor (TFT), or the like may be formed on the surface of the silicon substrate or the like. In addition, a barrier rib matrix may be formed.

In order to be ejected from a piezo inkjet head, which is an example of an inkjet injector, to form an appropriate phase on a substrate, properties such as viscosity, fluidity, and quantum dot particles must be balanced with the inkjet head. The piezo inkjet head used in the present invention is not limited, but ejects ink having a droplet size of about 10 to 100 pL, preferably about 20 to 40 pL.

The viscosity of the light conversion ink composition of the present invention is suitably about 3 to 30 cP at 25° C., more preferably in the range of 7 to 20 cP.

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

One embodiment of the present invention relates to an image display device provided with the above-described color filter.

The color filter of the present invention can display various types of images such as an electroluminescent display (EL), a plasma display (PDP), a field emission display (FED), and an organic light emitting diode (OLED) as well as a general liquid crystal display (LCD). Applicable to the device.

The image display apparatus of the present invention includes a configuration known in the art, except for having the above-described color filter.

Hereinafter, the present invention will be described in more detail by way of Examples, Comparative Examples and Experimental Examples. These Examples, Comparative Examples, and Experimental Examples are only for illustrating the present invention, and it is apparent to those skilled in the art that the scope of the present invention is not limited thereto.

Synthesis Example 1: Synthesis of quantum dots (Q-1)

0.4 mmol (0.058 g) of indium acetate, 0.6 mmol (0.15 g) of palmitic acid, and 20 mL of 1-octadecene were placed in a reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was switched to nitrogen. After heating to 280° C., _{a mixed solution of 0.2 mmol (58 μl) of tris (trimethylsilyl) phosphine (TMS 3} P) and 1.0 mL of trioctylphosphine was quickly injected and reacted for 1 minute.

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

Then, 2.4 mmol of zinc acetate (0.448 g), 4.8 mmol of oleic acid and 20 mL of trioctylamine were placed in a reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was switched to nitrogen and the temperature of the reactor was raised to 280°C. 2 ml of the previously synthesized InP/ZnSe core-shell solution was added, followed by 4.8 mmol of sulfur (S/TOP) in trioctylphosphine, and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution cooled quickly to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and dried under reduced pressure to obtain a precipitate having an InP/ZnSe/ZnS core-shell structure. The maximum emission peak of the photoluminescence spectrum of the obtained nano quantum dots was 535 nm.

5 mL of the previously obtained quantum dot solution was placed in a centrifuge tube, and 20 mL of ethanol was added to precipitate. The supernatant was discarded through centrifugation, and 2 mL of chloroform was added to the precipitate to disperse the quantum dots, then 0.50 g of (2-butoxyethoxy)acetic acid was added and reacted for one hour while heating to 60° C. under a nitrogen atmosphere.

Then, 25 mL of n-hexane was added to the reaction to precipitate quantum dots, and then centrifuged to obtain quantum dots (Q-1).

Preparation Example 1: Preparation of quantum dot dispersion (A-1)

A quantum dot dispersion (A-1) was prepared by mixing 47.6 parts by weight of quantum dots (Q-1) and 52.4 parts by weight of low-viscosity monomer isobornyl acrylate as a diluent and reacting for 4 hours while heating at 60° C. under a nitrogen atmosphere.

Preparation Example 2: Preparation of quantum dot dispersion (A-2)

47.6 parts by weight of quantum dots (Q-1) and 52.4 parts by weight of low-viscosity monomer 1,6-hexanediol diacrylate as a diluent were mixed and reacted for 4 hours while heating at 60° C. in a nitrogen atmosphere to obtain a quantum dot dispersion (A-2) prepared.

Preparation Example 3: Preparation of quantum dot dispersion (A-3)

47.6 parts by weight of quantum dots (Q-1) and 52.4 parts by weight of high-viscosity monomer ditrimethylolpropanetetra (meth)acrylate as a diluent were mixed and reacted for 4 hours while heating at 60° C. under a nitrogen atmosphere to obtain a quantum dot dispersion (A-3) prepared.

Preparation Example 4: Preparation of scattering particle dispersion (D-1)

_{70.0 parts by weight of TiO 2 having a} particle size of 210 nm as scattering particles (CR-63 from Ishihara) 4.0 parts by weight of DISPERBYK-2001 (manufactured by BYK) as a dispersant and 26 parts by weight of a low-viscosity monomer 1,6-hexanediol diacrylate as a diluent A scattering particle dispersion (D-1) was prepared by mixing and dispersing for 12 hours using a bead mill.

Examples and Comparative Examples: Preparation of Light Conversion Ink Compositions

A light conversion ink composition was prepared by mixing each component in the composition of Tables 1 and 2 below (wt%).

Example One 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Quantum Dot Dispersion A-1 50.0 50.0 50.0 50.0 50.0 50.0 50.0 50.0 A-2 50.0 50.0 50.0 50.0 50.0 50.0 50.0 50.0 A-3 curable monomer B-1 39.2 39.2 39.2 39.2 39.2 39.2 39.2 39.2 B-2 39.2 39.2 39.2 39.2 39.2 39.2 39.2 39.2 B-3 photoacid generator C-1 2.0 2.0 2.0 2.0 1.0 1.0 1.0 1.0 C-2 2.0 2.0 2.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 initiator E-1 1.0 1.0 1.0 1.0 scattering particle dispersion D-1 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 additive F-1 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2

comparative example One 2 3 4 5 6 7 8 9 10 Quantum Dot Dispersion A-1 50.0 50.0 50.0 A-2 50.0 50.0 50.0 A-3 50.0 50.0 50.0 50.0 curable monomer B-1 39.2 39.2 39.2 39.2 B-2 39.2 39.2 39.2 B-3 39.2 39.2 39.2 photoacid generator C-1 2.0 2.0 2.0 2.0 2.0 C-2 initiator E-1 2.0 2.0 2.0 2.0 2.0 scattering particle dispersion D-1 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 8.6 additive F-1 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2

A-1: Quantum dot dispersion prepared in Preparation Example 1 (including isobornyl acrylate as a diluent)

A-2: Quantum dot dispersion prepared in Preparation Example 2 (including 1,6-hexanediol diacrylate as a diluent)

A-3: Quantum dot dispersion prepared in Preparation Example 3 (including ditrimethylolpropanetetra (meth)acrylate as a diluent)

B-1: isobornyl acrylate (viscosity: 5 ~ 10 cP, 25 ℃)

B-2: 1,6-hexanediol diacrylate (viscosity: 5 to 10 cP, 25°C)

B-3: ditrimethylolpropane tetra (meth) acrylate (viscosity: 400 ~ 600 cP, 25 ℃)

C-1: a compound represented by the following formula (5)

[Formula 5]

C-2: a compound represented by the following formula (7)

[Formula 7]

D-1: scattering particle dispersion prepared in Preparation Example 4

E-1: TPO (BASF)

F-1: F-554 (DIC Corporation)

Experimental example:

The light conversion coating layer was prepared as follows using the light conversion ink composition prepared in Examples and Comparative Examples, and the film thickness, brightness, dispersibility, high humidity condition reliability and viscosity were measured in the following way, and the The results are shown in Tables 3 and 4 below.

<Preparation of light conversion coating layer>

Each of the photoconversion ink compositions prepared in Examples and Comparative Examples was applied on a 5cm×5cm glass substrate by an inkjet method, and then 1000mJ/cm2 using a 1kW high-pressure mercury lamp containing all g, h, and i lines as an ultraviolet light source. After irradiation with a furnace, it was heated in a heating oven at 180° C. for 30 minutes to prepare a light conversion coating layer.

(1) film thickness

The film thickness of the light conversion coating layer prepared above was measured using a film thickness meter (Dektak 6M, Vecco).

(2) luminance

After placing the above-prepared light conversion coating layer on a blue light source (XLamp XR-E LED, Royal blue 450, Cree Corporation), using a luminance meter (CAS140CT Spectrometer, Instrument systems), when irradiating blue light The luminance was measured.

(3) dispersibility

In the manufacturing process of the light conversion ink composition, the liquid sample before the scattering particles were visually checked and evaluated according to the following evaluation criteria.

<Evaluation criteria>

○: Transparent state

×: cloudy state

(4) High humidity condition reliability

For the light conversion coating layer prepared above, the change in luminous efficiency characteristics due to high humidity conditions was confirmed by Equation 1 below. Specifically, the light conversion coating layer was left in a high-humidity condition of 85% for 12 hours, and the luminous efficiency before and after leaving was measured to calculate the luminous efficiency maintenance rate by Equation 1 below.

[Equation 1]

Luminous efficiency retention rate (%) = {(luminous efficiency after exposure to high humidity conditions) / (luminous efficiency before exposure to high humidity conditions)} × 100

The high-humidity condition reliability was evaluated according to the following evaluation criteria.

<Evaluation criteria>

○: Luminous efficiency retention of 90% or more

×: Luminous efficiency retention rate is less than 90%

(5) Viscosity

The viscosity of the light conversion ink composition was measured using an R-type viscometer (VISCOMETER MODEL RE120L SYSTEM, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 20 rpm and a temperature of 25°C.

Evaluation results Film thickness (㎛) Luminance (lx) dispersibility Reliability in high humidity conditions Viscosity (cP) Example 1 10 1214 ○ ○ 9.14 Example 2 10 1208 ○ ○ 14.56 Example 3 10 1217 ○ ○ 12.75 Example 4 10 1220 ○ ○ 17.9 Example 5 10 1183 ○ ○ 9.18 Example 6 10 1179 ○ ○ 14.6 Example 7 10 1198 ○ ○ 12.77 Example 8 10 1195 ○ ○ 18.2 Example 9 10 1202 ○ ○ 9.36 Example 10 10 1211 ○ ○ 14.58 Example 11 10 1216 ○ ○ 12.74 Example 12 10 1223 ○ ○ 18.33 Example 13 10 1148 ○ ○ 9.42 Example 14 10 1160 ○ ○ 14.71 Example 15 10 1125 ○ ○ 12.66 Example 16 10 1147 ○ ○ 18.32

Evaluation results Film thickness (㎛) Luminance (lx) dispersibility Reliability in high humidity conditions Viscosity (cP) Comparative Example 1 10 1107 ○ × 78.37 Comparative Example 2 10 1114 ○ × 83.85 Comparative Example 3 10 1132 × × 174.9 Comparative Example 4 10 1143 × × 112.7 Comparative Example 5 10 1128 × × 116.4 Comparative Example 6 10 1054 ○ × 13.67 Comparative Example 7 10 1068 ○ × 18.02 Comparative Example 8 10 1039 ○ × 14.36 Comparative Example 9 10 1030 ○ × 18.21 Comparative Example 10 10 1021 × × 78.37

As shown in Tables 3 to 4, the light conversion ink composition of an embodiment comprising a nonionic photoacid generator according to the present invention, and a curable monomer having a viscosity of 30 cP or less at 25 ° C. It was confirmed that the acidity was good, the optical properties did not deteriorate after the UV process, and the optical properties were excellent, and the long-term reliability in a high humidity state was confirmed. On the other hand, the light conversion ink composition of Comparative Example which does not contain a nonionic photoacid generator or which contains a curable monomer having a viscosity of more than 30 cP at 25° C. as a curable monomer has poor dispersibility or a decrease in optical properties after UV process Or, it could be confirmed that the long-term reliability in a high humidity state is inferior.

As the specific part of the present invention has been described in detail above, for those of ordinary skill in the art to which the present invention pertains, it is clear that these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereto. do. Those of ordinary skill in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (10)

Quantum dots, curable monomers and nonionic photoacid generators,
The curable monomer is a light conversion ink composition comprising a curable monomer having a viscosity of 30 cP or less at 25 ℃. According to claim 1, wherein the curable monomer is a light conversion ink composition comprising a monofunctional (meth) acrylate or polyfunctional (meth) acrylate having a viscosity of 30 cP or less at 25 ℃. The photoconversion ink composition of claim 1, wherein the nonionic photoacid generator generates an acid compound represented by the following formula (1):
[Formula 1]

In the above formula, R is a C ₁ -C ₄ aliphatic hydrocarbon group. The photoconversion ink composition of claim 1, wherein the nonionic photoacid generator comprises at least one of the compounds represented by the following Chemical Formulas 2 to 3:
[Formula 2]

[Formula 3]

In the above formula, R is a C ₁ -C ₄ aliphatic hydrocarbon group. The light conversion ink composition of claim 1, wherein the nonionic photoacid generator is included in an amount of 0.1 to 10% by weight based on 100% by weight of the total composition. The light conversion ink composition according to claim 1, further comprising at least one selected from the group consisting of scattering particles, a photopolymerization initiator, a surfactant, and an antioxidant. The photoconversion ink composition according to claim 1, wherein the solvent is contained in an amount of 1 wt% or less. A light conversion pixel comprising a cured product of the light conversion ink composition according to any one of claims 1 to 7. A color filter comprising the light conversion pixel according to claim 8 . An image display device comprising the color filter according to claim 9 .