WO2022092556A1 - Curable composition for electrophoretic apparatus, cured film using same, and display device - Google Patents

Abstract

Provided are a curable composition for an electrophoretic apparatus, a cured film prepared using the curable composition for an electrophoretic apparatus, and a display device using same, wherein the curable composition comprises: (A) a semiconductor nanorod; (B) a polymerizable monomer containing a first monomer and a second monomer; (C) a polymerization initiator; and (D) a solvent, the first monomer containing a thiol group, the second monomer containing a carbon-carbon double bond.

Description

Curable composition for electrophoresis device, cured film and display device using same

The present disclosure relates to a curable composition for an electrophoretic device, a cured film using the same, and a display device.

LED development has been actively carried out in 1992 when Nakamura et al. of Nichia Corporation in Japan succeeded in fusing a high-quality single-crystal GaN nitride semiconductor by applying a low-temperature GaN compound buffer layer. The LED is a semiconductor having a structure in which an n-type semiconductor crystal in which a plurality of carriers are electrons and a p-type semiconductor crystal in which a plurality of carriers are holes using the characteristics of a compound semiconductor are bonded to each other. It is a semiconductor device that is converted into light and expressed.

These LED semiconductors have high light conversion efficiency, so they consume very little energy, have a semi-permanent lifespan and are environmentally friendly, so they are called the revolution of light as a green material. Recently, with the development of compound semiconductor technology, high-brightness red, orange, green, blue and white LEDs have been developed, and by using them, many fields such as traffic lights, mobile phones, automobile headlights, outdoor electric signs, LCD BLU (back light unit), and indoor/outdoor lighting It is being applied in and active research continues at home and abroad. In particular, GaN-based compound semiconductors with a wide bandgap are materials used for manufacturing LED semiconductors that emit light in green, blue, and ultraviolet regions, and since it is possible to manufacture white LED devices using blue LED devices, a lot of research on this is being done

Among these series of studies, research using ultra-small LED devices in which the size of LEDs are manufactured in nano or micro units is being actively conducted, and research to utilize these ultra-small LED devices for lighting and displays is continuing. The areas that are continuously attracting attention in these studies are the electrode that can apply power to the ultra-small LED device, the electrode arrangement for the purpose of use and reduction of the space occupied by the electrode, and the method of mounting the micro LED on the placed electrode. .

Among them, in the method of mounting the micro-LED device on the disposed electrode, there is still a very difficult difficulty in arranging and mounting the micro-LED device on the electrode as intended due to the size restrictions of the micro-LED device. This is because, since the ultra-small LED device is of a nano-scale or micro-scale, it is impossible to place and mount each electrode on a target electrode area by hand.

Recently, the demand for nano-scale ultra-small LED devices is increasing, and for this purpose, attempts are made to manufacture nano-scale GaN-based compound semiconductors or InGaN-based compound semiconductors as rods. A composition that simultaneously satisfies the patterning properties has not been reported.

One embodiment is to provide a curable composition containing semiconductor nanorods capable of simultaneously performing patterning using inkjetting, dielectrophoresis, and wet etching.

Another embodiment is to provide a cured film prepared by using the curable composition for an electrophoretic device.

Another embodiment is to provide a display device including the cured film.

One embodiment is (A) a semiconductor nanorod; (B) a polymerizable monomer comprising a first monomer and a second monomer; (C) a polymerization initiator; and (D) a solvent, wherein the first monomer includes a thiol group, and the second monomer includes a carbon-carbon double bond at a terminal thereof.

The first monomer may further include an ester linking group.

The first monomer may include a functional group represented by Formula 1 below.

[Formula 1]

In Formula 1,

L ¹ and L ² are each independently a single bond or a substituted or unsubstituted C1 to C20 alkylene group,

n is an integer of 0 or 1.

The first monomer may include at least one compound selected from the group consisting of the following Chemical Formulas 1-1 to 1-3.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

In Formulas 1-1 to 1-3,

L ³ To L ⁵ are each independently a substituted or unsubstituted C1 to C20 alkylene group,

R ¹ is a substituted or unsubstituted C1 to C20 alkyl group,

n1 is an integer from 0 to 3, n2 is an integer from 1 to 4, and n1 + n2 = 4.

The first monomer is 1,2-ethanedithiol, 1,3-propanedithiol, 1,6-hexanedithiol, glycol dimercaptoacetate, glycol di-3-mercaptopropionate, thimethylolpropane tris(3-mercaptopropionate), pentaerythrithol tetrakis (3-mercaptopropionate), pentaerythrithol tetrakis (2-mercaptoacetate) or a combination thereof.

The second monomer may include a (meth)acrylic compound having a carbon-carbon double bond at the terminal thereof.

The first monomer and the second monomer may be included in a weight ratio of 9:1 to 1:9.

The solvent may include a compound represented by the following formula (4).

[Formula 4]

In Formula 4,

R ⁹ to R ¹¹ are each independently a hydrogen atom or a C1 to C10 alkyl group,

R ¹² is a hydrogen atom or *-C(=O)R ¹³ (R ¹³ is a C1 to C10 alkyl group);

L ¹⁶ and L ¹⁷ are each independently a substituted or unsubstituted C1 to C20 alkylene group or a substituted or unsubstituted C6 to C20 arylene group,

L ¹⁸ is *-O-*, *-S-* or *-NH-*.

The semiconductor nanorods may have a diameter of 300 nm to 900 nm.

The semiconductor nanorods may have a length of 3.5 μm to 5 μm.

The semiconductor nanorods may include a GaN-based compound, an InGaN-based compound, or a combination thereof.

The semiconductor nanorods may have a surface coated with a metal oxide.

The metal oxide may include alumina, silica, or a combination thereof.

The semiconductor nanorods may be included in an amount of 0.01 wt% to 10 wt% based on the total amount of the curable composition for the electrophoretic device.

The ink composition for the electrophoresis device includes malonic acid; 3-amino-1,2-propanediol; silane-based coupling agent; leveling agent; fluorine-based surfactants; Or it may further include a combination thereof.

Another embodiment provides a cured film prepared using the ink composition for an electrophoretic device.

Another embodiment provides a display device including the cured film.

The specific details of other aspects of the invention are included in the detailed description below.

Compared with the existing process, curing can be performed immediately after dielectrophoresis, thereby improving the panel defect rate and semiconductor nanorod alignment rate.

1 is an example of a cross-sectional view of a semiconductor nanorod used in a curable composition for an electrophoretic device according to an embodiment.

FIG. 2 is a scanning electron microscope (SEM) photograph of a specimen patterned using the curable composition according to Example 1. FIG.

3 is a scanning electron microscope (SEM) photograph of a specimen patterned using the curable composition according to Example 2.

4 is a scanning electron microscope (SEM) photograph of a specimen patterned using the curable composition according to Example 3.

5 is a scanning electron microscope (SEM) photograph of a specimen patterned using the curable composition according to Example 4.

Hereinafter, embodiments of the present invention will be described in detail. However, this is provided as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

Unless otherwise specified herein, "alkyl group" means a C1 to C20 alkyl group, "alkenyl group" means a C2 to C20 alkenyl group, "cycloalkenyl group" means a C3 to C20 cycloalkenyl group, , "heterocycloalkenyl group" means a C3 to C20 heterocycloalkenyl group, "aryl group" means a C6 to C20 aryl group, "arylalkyl group" means a C6 to C20 arylalkyl group, "alkylene group" means a C1 to C20 alkylene group, "arylene group" means a C6 to C20 arylene group, "alkylarylene group" means a C6 to C20 alkylarylene group, and "heteroarylene group" means a C3 to C20 hetero It means an arylene group, and "alkoxyylene group" means a C1 to C20 alkoxyylene group.

Unless otherwise specified herein, "substitution" means that at least one hydrogen atom is a halogen atom (F, Cl, Br, I), a hydroxy group, a C1 to C20 alkoxy group, a nitro group, a cyano group, an amine group, an imino group, Azido group, amidino group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, ether group, carboxyl group or a salt thereof, sulfonic acid group or a salt thereof, phosphoric acid or a salt thereof, C1 to C20 alkyl group, C2 to C20 alkenyl group, C2 to C20 alkynyl group, C6 to C20 aryl group, C3 to C20 cycloalkyl group, C3 to C20 cycloalkenyl group, C3 to C20 cycloalkynyl group, C2 to C20 heterocycloalkyl group, C2 to C20 heterocycloalkenyl group, C2 to C20 heterocycloalkynyl group, C3 to C20 heteroaryl group, or a combination thereof means substituted with a substituent.

In addition, unless otherwise specified in the present specification, "hetero" means that at least one hetero atom among N, O, S and P is included in the formula.

In addition, unless otherwise specified herein, "(meth)acrylate" means that both "acrylate" and "methacrylate" are possible, and "(meth)acrylic" means "acrylic" and "methacrylic" “It means that both are possible.

Unless otherwise specified herein, "combination" means mixing or copolymerization.

Unless otherwise defined in the chemical formulas in the present specification, when a chemical bond is not drawn at a position where a chemical bond is to be drawn, it means that a hydrogen atom is bonded to the position.

As used herein, the term “semiconductor nanorod” refers to a rod-shaped semiconductor having a nano-size diameter.

In addition, unless otherwise specified in the present specification, "*" means a moiety connected to the same or different atoms or chemical formulas.

The curable composition for an electrophoretic device according to an embodiment includes (A) a semiconductor nanorod; (B) a polymerizable monomer comprising a first monomer and a second monomer; (C) a polymerization initiator; and (D) a solvent, wherein the first monomer includes a thiol group, and the second monomer includes a carbon-carbon double bond.

Recently, research on various concepts that have the effect of improving energy efficiency and preventing efficiency drop of existing LEDs, such as micro LED and mini LED, is being actively conducted. Among them, the alignment (electrophoresis) of InGaN-based nanorod LEDs using an electric field is attracting attention as a method that can dramatically reduce the complicated and expensive process costs of micro LEDs and mini LEDs.

In order to make a panel through the alignment of semiconductor nano rods, a very complex and lengthy process such as inkjet coating-dielectrophoretic alignment-solvent drying-inorganic deposition-photoresist patterning for inorganic deposition layer patterns is in progress. When the curable composition for an electrophoretic device according to an embodiment is used, since an inorganic deposition process is unnecessary, there is an advantage in that the panel defect rate and alignment rate can be improved compared to the existing process.

Hereinafter, each component will be described in detail.

(A) semiconductor nanorods

The semiconductor nanorods may include a GaN-based compound, an InGaN-based compound, or a combination thereof, and the surface thereof may be coated with a metal oxide.

For dispersion stability of the semiconductor nanorod ink solution (semiconductor nanorod + solvent), it usually takes about 3 hours, which is insufficient time to perform a large-area inkjet process. Accordingly, the present inventors, after numerous trial and error studies, coated the surface of the semiconductor nanorods with a metal oxide containing alumina, silica, or a combination thereof to form an insulating film (Al ₂ O ₃ or SiO _x ), thereby forming an insulating film (Al 2 O 3 or SiO x ). compatibility could be maximized.

For example, the insulating layer coated with the metal oxide may have a thickness of 40 nm to 60 nm.

The semiconductor nanorod includes an n-type confinement layer and a p-type confinement layer, and a multi-quantum well active part ( MQW active region; multi quantum well active region) may be located. (See Fig. 1)

For example, the semiconductor nanorods may have a diameter of 300 nm to 900 nm, for example, 600 nm to 700 nm.

For example, the semiconductor nanorods may have a length of 3.5 μm to 5 μm.

For example, when the semiconductor nanorod includes an alumina insulating layer, it may have a density of 5 g/cm ³ to 6 g/cm ³ .

For example, the semiconductor nanorods may have a mass of 1 x 10 ^-13 g to 1 x 10 ^-11 g.

When the semiconductor nanorods have the diameter, length, density and type, the surface coating of the metal oxide may be easy, and dispersion stability of the semiconductor nanorods may be maximized.

The semiconductor nanorods may be included in an amount of 0.01 wt% to 10 wt%, for example 0.02 wt% to 8 wt%, such as 0.03 wt% to 5 wt%, based on the total amount of the curable composition. When the semiconductor nanorods are included within the above range, dispersion in ink is good, and the prepared pattern may have excellent luminance.

(B) polymerizable monomer

The patterning composition used in the existing display and electronic materials used an acryl-based or cardo-based binder resin, and after pattern exposure using the acidity of the carboxylic acid of the binder resin, an alkali developer (aq. KOH, TMAH solution) was used to the non-exposed part (uncured portion) was dissolved to make patterning. However, due to the organic polymer binder resin, the entire solution was disadvantageous in terms of viscoelasticity and high temperature stability, and aggregation through binding on the surface of the semiconductor nanorods occurred, which adversely affected ink jetting properties, dispersion stability, and dielectrophoretic properties.

However, the curable composition according to an embodiment is a pattern-curing composition with a completely new concept from the prior art, which overcomes all conventional problems by newly designing a polymerizable monomer advantageous in inkjetting properties and dielectrophoretic properties.

For example, the first monomer may further include an ester linking group.

The pKa of carboxylic acid, which is the development site of the developable acrylic binder resin, is 5. aq. When KOH developer is encountered, all sites react in the form of water-soluble salt with the equilibrium constant K = 1011 and dissolve in water. Instead of the existing carboxylic acid, the pKa of thiol attached to the alpha- and beta- positions of the ester is about 8 to 9.5, and aq. When KOH is encountered, the equilibrium constant K = 108 also causes all sites to react in water-soluble salt form and dissolve in water. A thiol compound is insoluble in neutral water and phase separated, but aq. In a basic aqueous solution such as KOH or TMAH, a salt is formed and dissolved immediately.

Using the characteristics of the thiol compound and the thiol-ene reaction, which is a fast and reliable click reaction, pattern developability was realized only with a monomer without the existing acrylic binder resin or cardo-based binder resin. When the thiol-ene reaction proceeds in the exposed part, the acidic proton of thiol participates in the reaction and disappears, and cross-linking causes aq. It becomes inert (inert) in the basic developer, whereas the acidic proton of thiol in the area where the thiol-ene reaction has not progressed in the unexposed part remains as it is, so aq. It is dissolved in the basic developer to impart development.

That is, since the curable composition according to an embodiment is composed only of monomers without an organic polymer (binder resin), it may be advantageous in ink jetting properties and dielectrophoretic properties compared to a developer including a conventional binder resin.

For example, the first monomer may include a functional group represented by Formula 1 below.

[Formula 1]

In Formula 1,

L ¹ and L ² are each independently a single bond or a substituted or unsubstituted C1 to C20 alkylene group,

n is an integer of 0 or 1.

For example, the first monomer may include at least one compound selected from the group consisting of the following Chemical Formulas 1-1 to 1-3.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

In Formulas 1-1 to 1-3,

L ³ To L ⁵ are each independently a substituted or unsubstituted C1 to C20 alkylene group,

R ¹ is a substituted or unsubstituted C1 to C20 alkyl group,

n1 is an integer from 0 to 3, n2 is an integer from 1 to 4, and n1 + n2 = 4.

The first monomer is 1,2-ethanedithiol, 1,3-propanedithiol, 1,6-hexanedithiol, glycol dimercaptoacetate, glycol di-3-mercaptopropionate, thimethylolpropane tris(3-mercaptopropionate), pentaerythrithol tetrakis (3-mercaptopropionate), pentaerythrithol tetrakis (2-mercaptoacetate) or a combination thereof, but is not necessarily limited thereto.

The second monomer may be a compound including a carbon-carbon double bond at the terminal.

For example, the second monomer may have a different structure from the first monomer.

For example, the second monomer may include a (meth)acrylic compound including a carbon-carbon double bond at the terminal.

For example, the second monomer is a polymerizable compound used in conventional thermosetting or photocuring compositions, and is divinyl benzene, triallyl trimellitate, triallyl phosphate, triallyl phosphite, triallyl triazine, diallyl phthalate. , Ethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol diacrylate, pentaerythritol Triacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, pentaerythritol hexaacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, novolac Epoxy acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol Dimethacrylate, polyfunctional epoxy (meth) acrylate, polyfunctional urethane (meth) acrylate, KAYARAD DPCA-20, KAYARAD DPCA-30, KAYARAD DPCA-60, KAYARAD DPCA-120, KAYARAD DPEA- 12 or a combination thereof, and the like, but is not necessarily limited thereto.

The first monomer and the second monomer may be included in a weight ratio of 9:1 to 1:9.

The first monomer may be included in an amount of 2 wt% to 80 wt% based on the total amount of solids constituting the curable composition according to an embodiment.

The second monomer may be included in an amount of 2 wt% to 80 wt% based on the total amount of solids constituting the curable composition according to an embodiment.

(C) polymerization initiator

The curable composition for an electrophoretic device according to an embodiment includes a polymerization initiator, for example, a photopolymerization initiator, a thermal polymerization initiator, or a combination thereof.

The photopolymerization initiator is an initiator generally used in the curable curable composition, for example, an acetophenone-based compound, a benzophenone-based compound, a thioxanthone-based compound, a benzoin-based compound, a triazine-based compound, an oxime-based compound, an aminoketone-based compound and the like may be used, but is not necessarily limited thereto.

Examples of the acetophenone-based compound include 2,2'-diethoxy acetophenone, 2,2'-dibutoxy acetophenone, 2-hydroxy-2-methylpropiophenone, p-t-butyltrichloroacetophenone, p-t-Butyldichloro acetophenone, 4-chloro acetophenone, 2,2'-dichloro-4-phenoxy acetophenone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane- 1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, etc. are mentioned.

Examples of the benzophenone-based compound include benzophenone, benzoylbenzoic acid, methylbenzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4,4'-bis(dimethyl amino)benzophenone, 4,4 and '-bis(diethylamino)benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-dichlorobenzophenone, and 3,3'-dimethyl-2-methoxybenzophenone.

Examples of the thioxanthone-based compound include thioxanthone, 2-methylthioxanthone, isopropyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2- Chlorothioxanthone etc. are mentioned.

Examples of the benzoin-based compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and benzyldimethyl ketal.

Examples of the triazine-based compound 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, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine , 2-Biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho-1-yl)- 4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-4 -bis(trichloromethyl)-6-piperonyl-s-triazine, 2-4-bis(trichloromethyl)-6-(4-methoxystyryl)-s-triazine, etc. are mentioned. .

Examples of the oxime-based compound include an O-acyloxime-based compound, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, and 1-(O-acetyloxime) -1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, O-ethoxycarbonyl-α-oxyamino-1-phenylpropan-1-one, etc. can be used Specific examples of the O-acyloxime-based compound include 1,2-octanedione, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butane- 1-one, 1-(4-phenylsulfanylphenyl)-butane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenylsulfanylphenyl)-octane-1,2-dione -2-oxime-O-benzoate, 1-(4-phenylsulfanylphenyl)-octane-1-oneoxime-O-acetate and 1-(4-phenylsulfanylphenyl)-butan-1-oneoxime- O-acetate etc. are mentioned.

Examples of the aminoketone-based compound include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone -1) and the like.

As the photopolymerization initiator, a carbazole-based compound, a diketone-based compound, a sulfonium borate-based compound, a diazo-based compound, an imidazole-based compound, or a biimidazole-based compound may be used in addition to the above compound.

The photopolymerization initiator may be used together with a photosensitizer that causes a chemical reaction by absorbing light to enter an excited state and then transferring the energy.

Examples of the photosensitizer include tetraethylene glycol bis-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, dipentaerythritol tetrakis-3-mercaptopropionate, and the like. can be heard

Examples of the thermal polymerization initiator include peroxide, specifically benzoyl peroxide, dibenzoyl peroxide, lauryl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cyclohexane peroxide, methyl ethyl ketone peroxide Oxide, hydroperoxide (eg tert-butyl hydroperoxide, cumene hydroperoxide), dicyclohexyl peroxydicarbonate, 2,2-azo-bis(isobutyronitrile), t-butyl perbenzo ate, and the like, and 2,2'-azobis-2-methylpropionitrile, but is not necessarily limited thereto, and any one widely known in the art may be used.

The polymerization initiator may be included in an amount of 1 wt% to 5 wt%, for example 2 wt% to 4 wt%, based on the total amount of solids constituting the curable composition for the electrophoretic device. When the polymerization initiator is included within the above range, curing occurs sufficiently during exposure or thermal curing to obtain excellent reliability.

(D) solvent

The curable composition for an electrophoretic device according to an embodiment includes a solvent.

Recently, the need for nano-scale ultra-small LED devices is increasing, and for this purpose, attempts have been made to manufacture nano-scale GaN-based compound semiconductors or InGaN-based compound semiconductors as rods. The dispersion stability in the compound) is greatly reduced. And, until now, there has been no introduction of a technology capable of improving the dispersion stability of semiconductor nanorods in solution (or polymerizable compound).

Organic solvents such as propylene glycol monomethyl ether acetate (PEGMEA), Υ-butyrolactone (GBL), polyethylene glycol methyl ether (PGME), ethyl acetate, and isopropyl alcohol (IPA) used in conventional display and electronic materials have low viscosity. The sedimentation of the low-density inorganic nanorod particles is too fast and the dielectrophoretic properties are poor. Therefore, for the development of NED-Ink, it is preferable to use a solvent capable of providing sedimentation stability of the rod.

The solvent in the curable composition for an electrophoretic device according to an embodiment may include a compound represented by the following Chemical Formula 4.

[Formula 4]

In Formula 4,

R ⁹ to R ¹¹ are each independently a hydrogen atom or a C1 to C10 alkyl group,

R ¹² is a hydrogen atom or *-C(=O)R ¹³ (R ¹³ is a C1 to C10 alkyl group);

L ¹⁶ and L ¹⁷ are each independently a substituted or unsubstituted C1 to C20 alkylene group or a substituted or unsubstituted C6 to C20 arylene group,

L ¹⁸ is *-O-*, *-S-* or *-NH-*.

For example, the compound represented by Formula 4 may be citric acid.

For example, the compound represented by Formula 4 may be represented by any one of Formulas 4-1 to 4-6, but is not limited thereto.

[Formula 4-1]

[Formula 4-2]

[Formula 4-3]

[Formula 4-4]

[Formula 4-5]

[Formula 4-6]

The solvent may be included in an amount of 15 wt% to 90 wt%, such as 15 wt% to 85 wt%, such as 20 wt% to 80 wt%, based on the total amount of the curable composition for the electrophoretic device.

(E) other additives

The curable composition for an electrophoretic device according to an embodiment may further include a polymerization inhibitor including a hydroquinone-based compound, a catechol-based compound, or a combination thereof. As the curable composition according to an embodiment further includes the hydroquinone-based compound, the catechol-based compound, or a combination thereof, it is possible to prevent crosslinking at room temperature during exposure after printing (coating) the ink composition.

For example, the hydroquinone-based compound, catechol-based compound, or a combination thereof is hydroquinone, methyl hydroquinone, methoxyhydroquinone, t-butyl hydroquinone, 2,5-di- t -butyl hydroquinone, 2,5- Bis(1,1-dimethylbutyl) hydroquinone, 2,5-bis(1,1,3,3-tetramethylbutyl) hydroquinone, catechol, t-butyl catechol, 4-methoxyphenol, pyroga Rol, 2,6-di- t -butyl-4-methylphenol, 2-naphthol, tris(N-hydroxy-N-nitrosophenylaminato-O,O')aluminum (Tris(N-hydroxy-N) -nitrosophenylaminato-O,O')aluminium) or a combination thereof, but is not necessarily limited thereto.

The hydroquinone-based compound, the catechol-based compound, or a combination thereof may be used in the form of a dispersion, and the polymerization inhibitor in the dispersion form is 0.001 wt% to 1 wt%, such as 0.01 wt% to 0.1 wt%, based on the total amount of the curable composition can be included as When the stabilizer is included within the above range, it is possible to solve the problem of aging at room temperature and, at the same time, to prevent a decrease in sensitivity and a surface peeling phenomenon.

The curable composition for an electrophoretic device according to an embodiment includes malonic acid in addition to the polymerization inhibitor; 3-amino-1,2-propanediol; silane-based coupling agent; leveling agent; fluorine-based surfactants; Or it may further include a combination thereof.

For example, the curable composition for an electrophoretic device may further include a silane-based coupling agent having a reactive substituent such as a vinyl group, a carboxyl group, a methacryloxy group, an isocyanate group, and an epoxy group in order to improve adhesion to the substrate.

Examples of the silane-based coupling agent include trimethoxysilyl benzoic acid, γ-methacryl oxypropyl trimethoxysilane, vinyl triacetoxysilane, vinyl trimethoxysilane, γ-isocyanate propyl triethoxysilane, γ-glycan Cydoxy propyl trimethoxysilane, β-epoxycyclohexyl)ethyltrimethoxysilane, etc. are mentioned, and these may be used individually or in mixture of 2 or more types.

The silane-based coupling agent may be included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the curable composition for an electrophoretic device. When the silane-based coupling agent is included within the above range, adhesion and storage properties are excellent.

In addition, the curable composition for an electrophoretic device may further include a surfactant, such as a fluorine-based surfactant, to improve coating properties and prevent defect formation, if necessary.

Examples of the fluorine-based surfactant include BM-1000 ^® , BM-1100 ^® and the like by BM Chemie; Mecha Pack F 142D ^® , Mecha Pack F 172 ^® , Mecha Pack F 173 ^® , Mecha Pack F 183 ^® and the like of Dai Nippon Inki Chemical High School Co., Ltd.; Sumitomo 3M Co., Ltd.'s Prorad FC-135 ^® , Prorad FC-170C ^® , Prorad FC-430 ^® , Prorad FC-431 ^® and the like; Asahi Grass Co., Ltd. Saffron S-112 ^® , Saffron S-113 ^® , Saffron S-131 ^® , Saffron S-141 ^® , Saffron S-145 ^® , etc.; SH-28PA ^® , SH-190 ^® , SH-193 ^® , SZ-6032 ^® , SF-8428 ^® of Toray Silicone Co., Ltd.; F-482, F-484, F-478, F-554 commercially available fluorine-based surfactants of DIC Co., Ltd. may be used.

The fluorine-based surfactant may be used in an amount of 0.001 parts by weight to 5 parts by weight based on 100 parts by weight of the curable composition for an electrophoretic device. When the fluorine-based surfactant is included within the above range, coating uniformity is secured, stains do not occur, and wettability to a glass substrate is excellent.

In addition, a predetermined amount of other additives such as antioxidants and stabilizers may be further added to the curable composition for an electrophoretic device within a range that does not impair physical properties.

Another embodiment provides a cured film using a curable composition for an electrophoretic device.

Another embodiment provides a display device including the cured film or a display device manufactured using the curable composition for an electrophoretic device.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only preferred examples of the present invention, and the present invention is not limited thereto.

(Preparation of curable composition for electrophoresis device)

Examples 1 to 4, Comparative Example 1 and Comparative Example 2

40 ml of stearic acid (1.5 mM) was reacted on a GaN wafer (4 inch) patterned with nano rods at room temperature for 24 hours. After the reaction, soak in 50 ml of acetone for 5 minutes to remove excess stearic acid, and additionally rinse the wafer surface using 40 ml of acetone. Put the cleaned wafer into a 27kW bath type sonicator with 35ml of GBL, and use sonication for 5 minutes to separate the rod from the wafer surface. Put the separated rod into a FALCON tube dedicated to the centrifuge and add 10ml of GBL to further wash the rod on the bath surface. Centrifuge at 4000rpm for 10 minutes, discard the supernatant, and redisperse the precipitate in acetone (40ml) to filter out foreign substances using a 10㎛ mesh filter. After additional centrifugation (4000 rpm, 10 minutes), the precipitate is dried in a drying oven (100° C. for 1 hour), then the weight is measured, and dispersed to 0.2 w/w% in the ink composition having the composition according to Table 1 below. to manufacture

(Unit: g)

		Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2
first monomer	Pentaerythritol tetrakis (2-mercaptoacetate)	2.51	-	2.6	1.60	-	2.51
	Pentaerythritol tetrakis (3-mercaptopropionate)	-	2.51	-	-	-	-
second monomer	1,3,5-Triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione	1.60	1.60	2.6	2.51	1.60	-
photopolymerization initiator	PBG304	0.12	0.12	0.12	0.12	0.12	0.12
menstruum	Formula 4-4	25.3	25.3	25.3	25.3	25.3	25.3
other additives	F-554	0.006	0.006	0.006	0.006	0.006	0.006
	Polymerization inhibitor (MHQ)	0.007	0.007	0.007	0.007	0.007	0.007

(Synthesis of the compound represented by Formula 4-4)

Citric acid (100 g, 0.5205 mol) is dissolved in 500 ml of methanol, then p-toluenesulfonic acid (0.99 g, 0.00521 mol) is added and reacted under reflux condition for 12 hours. After 12 hours, the solvent is removed with a rotary evaporator, and 500 ml of ethyl acetate is added. By extracting the resulting organic layer, aq . After washing twice with 300ml of 10% NaHCO ₃ aqueous solution, additionally wash once with brine. After drying with MgSO ₄ , celite filter is performed. After filtering, the solvent was dried to obtain a compound represented by the following Chemical Formula 4-4 (trimethyl o-acetylcitrate).

[Formula 4-4]

Evaluation 1: Precipitation rate and dielectrophoretic properties of curable composition

Precipitation rates and dielectrophoretic properties of the curable compositions prepared in Examples 1 to 4, Comparative Examples 1 and 2 were measured using Turbiscan, respectively, and the results are shown in Table 2 below.

The method for measuring the dielectrophoretic properties is as follows.

First, 500 μl of the nanorod ink composition is applied to thin-film Gold basic interdigitated linear electrodes (ED-cIDE4-Au, Micrux), an electric field (25KHz, ±30v) is applied, and then waits for 1 minute. After drying the solvent using a hot plate, the number (ea) and the number (ea) aligned in the center between the electrodes were checked using a microscope to evaluate the dielectrophoretic properties.

	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2
Settling rate (mm/hr)	0.11	0.10	0.08	0.12	0.16	0.18
Dielectrophoretic properties (%)	92%	94%	93%	90%	92%	93%

As shown in Table 2, in the case of Examples 1 to 4, compared to Comparative Examples 1 and 2, it can be confirmed that the sedimentation rate is slow and at the same time the dielectrophoretic properties are excellent. It can be seen that the curable composition for an electrophoretic device according to the present invention greatly improves the dispersion stability of semiconductor nanorods and at the same time has very excellent dielectrophoretic properties, so that it is suitable for large-area coating and panel production.

Evaluation 2: Inkjetability and pattern resolution of the curable composition

For each of the curable compositions according to Examples 1 to 4, Comparative Example 1 and Comparative Example 2, the initial viscosity value was measured at 25° C. using a viscometer (Brookfield DV-II, RV-2 spindle, 23 rpm). The results are shown in Table 3, and the viscosity value is measured again after 15 days, and if the viscosity value after 15 days rises to less than 0.5 cps from the initial viscosity value or there is no change, it is determined as good, and the viscosity value after 15 days is If it rises to more than 0.5 cps from the initial viscosity value, it was determined as defective, and the results are shown in Table 3 below. It can be seen that the less the change in the viscosity value with time is, the better the ink jetting properties are.

The pattern resolution was determined by coating the curable composition to a thickness of 3 μm on a glass substrate using a spin coater (Mikasa, Opticoat MS-A150), respectively, and then using a hot-plate at 80° C. for 120 seconds. After baking (soft-baking), exposure was performed at a power of 60 mJ using an exposure machine (Ushio, ghi broadband). Then, using a developer (SVS, SSP-200) was developed with a 0.2 wt% potassium hydroxide (KOH) aqueous solution. Thereafter, the minimum μm of the remaining pattern was confirmed through an optical microscope, and the results are shown in Table 3 and FIGS. 2 to 5 below.

	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2
Initial viscosity (cPs)	83	24.6	24.9	24.4	29.5	31.3
ink jetting property	Good	Good	Good	Good	error	error
Pattern resolution (㎛)	5	4.5	10	15	pattern loss	pattern loss

As shown in Table 3 and FIGS. 2 to 5, in the case of Examples 1 to 4, compared to Comparative Examples 1 and 2, it can be seen that both the inkjetting property and the pattern resolution are excellent. (In the case of Comparative Examples 1 and 2, curing did not proceed properly, so that the film and the pattern itself did not remain after development.)

The present invention is not limited to the above embodiments, but can be manufactured in various different forms, and those of ordinary skill in the art to which the present invention pertains can take other specific forms without changing the technical spirit or essential features of the present invention. It will be understood that it can be implemented as Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (17)

1. (A) semiconductor nanorods;

   (B) a polymerizable monomer comprising a first monomer and a second monomer;

   (C) a polymerization initiator; and

   (D) solvent

   including,

   The first monomer comprises a thiol group,

   The second monomer is a curable composition for an electrophoretic device comprising a carbon-carbon double bond at the terminal.
2. According to claim 1,

   The first monomer is a curable composition for an electrophoretic device further comprising an ester linkage.
3. According to claim 1,

   The first monomer is a curable composition for an electrophoretic device comprising a functional group represented by the following Chemical Formula 1:

   [Formula 1]

   

   In Formula 1,

   L ¹ and L ² are each independently a single bond or a substituted or unsubstituted C1 to C20 alkylene group,

   n is an integer of 0 or 1.
4. According to claim 1,

   The first monomer is a curable composition for an electrophoretic device comprising at least one compound selected from the group consisting of the following Chemical Formulas 1-1 to 1-3:

   [Formula 1-1]

   

   [Formula 1-2]

   

   [Formula 1-3]

   

   In Formulas 1-1 to 1-3,

   L ³ To L ⁵ are each independently a substituted or unsubstituted C1 to C20 alkylene group,

   R ¹ is a substituted or unsubstituted C1 to C20 alkyl group,

   n1 is an integer from 0 to 3, n2 is an integer from 1 to 4, and n1 + n2 = 4.
5. According to claim 1,

   The first monomer is 1,2-ethanedithiol, 1,3-propanedithiol, 1,6-hexanedithiol, glycol dimercaptoacetate, glycol di-3-mercaptopropionate, thimethylolpropane tris(3-mercaptopropionate), pentaerythrithol tetrakis (3-mercaptopropionate), pentaerythrithol A curable composition for an electrophoretic device comprising tetrakis (2-mercaptoacetate) or a combination thereof.
6. According to claim 1,

   The second monomer is a carbon-curable composition for an electrophoretic device comprising a (meth)acrylic compound including a carbon double bond at the terminal.
7. According to claim 1,

   The curable composition for an electrophoretic device, wherein the first monomer and the second monomer are included in a weight ratio of 9:1 to 1:9.
8. According to claim 1,

   The solvent is a curable composition for an electrophoretic device comprising a compound represented by the following Chemical Formula 4:

   [Formula 4]

   

   In Formula 4,

   R ⁹ to R ¹¹ are each independently a hydrogen atom or a C1 to C10 alkyl group,

   R ¹² is a hydrogen atom or *-C(=O)R ¹³ (R ¹³ is a C1 to C10 alkyl group);

   L ¹⁶ and L ¹⁷ are each independently a substituted or unsubstituted C1 to C20 alkylene group or a substituted or unsubstituted C6 to C20 arylene group,

   L ¹⁸ is *-O-*, *-S-* or *-NH-*.
9. According to claim 1,

   The semiconductor nanorod is a curable composition for an electrophoretic device having a diameter of 300 nm to 900 nm.
10. According to claim 1,

    The semiconductor nanorod is a curable composition for an electrophoretic device having a length of 3.5 μm to 5 μm.
11. According to claim 1,

    The semiconductor nanorod is a curable composition for an electrophoretic device comprising a GaN-based compound, an InGaN-based compound, or a combination thereof.
12. According to claim 1,

    The semiconductor nanorod is a curable composition for an electrophoretic device whose surface is coated with a metal oxide.
13. 13. The method of claim 12,

    The metal oxide is a curable composition for an electrophoretic device comprising alumina, silica, or a combination thereof.
14. According to claim 1,

    The curable composition for an electrophoretic device, wherein the semiconductor nanorods are included in an amount of 0.01 wt% to 10 wt% based on the total amount of the curable composition.
15. According to claim 1,

    The ink composition for the electrophoresis device includes malonic acid; 3-amino-1,2-propanediol; silane coupling agent; leveling agent; fluorine-based surfactants; Or a curable composition for an electrophoretic device further comprising a combination thereof.
16. A cured film prepared by using the curable composition for an electrophoretic device according to any one of claims 1 to 15.
17. 17. The method of claim 16,

    A display device including the cured film.

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