KR20180068076A - Nano particle, insulator film and display device having the particle - Google Patents

Abstract

The present invention relates to nano-particles having porous particles or hollow particles which are arranged adjacent to each other and are connected through disulfide bonds, an insulation film including the nano-particles, and an organic light emitting diode display device having the insulation film applied as a bank layer. The nano-particles include the porous particles or hollow particles to lower the refractive index of the insulation film when being applied to the insulation film. The insulation film, which has the nano-particles dispersed therein, can significantly lower the refractive index compared to an adjacent light emitting diode when being used as the bank layer. Accordingly, the light from the light emitting diode can be fully reflected, thereby enhancing the light extraction efficiency. The nano-particles have a disulfide group enabling a self-healing mechanism for recombining or dissociating disulfides by using light emission, thereby healing defects and damage, such as scratches, which may occur on the insulation film or the bank layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a nanoparticle, an insulating film containing the nanoparticle,

The present invention relates to nanoparticles, and more particularly, to nanoparticles having a low refractive index and dielectric constant and improved damage recovery ability, an insulating film containing the nanoparticles, and a display device.

2. Description of the Related Art Recently, a display device using an organic light emitting diode (OLED) as a light emitting means has attracted attention in place of a liquid crystal display device (LCD). Since the organic light emitting diode display device has a self light emitting device, a backlight unit used in a liquid crystal display device is not required, and thus a lightweight and thin display device can be realized. In addition, the organic light emitting diode display device is superior in view angle and contrast ratio as compared with the liquid crystal display device, is advantageous in terms of power consumption, can be driven by low-voltage direct current, has a quick response speed, It is resistant to external impact and has a wide temperature range.

In general, an organic light emitting diode display includes a driving element on a lower substrate and a light emitting diode including an organic material layer such as a light emitting material or a charge transfer material. In addition, a bank layer for partitioning each pixel region is disposed adjacent to the light emitting diode.

Recently, a solution process for forming an organic layer constituting a light emitting diode through inkjet printing has been attracting attention. The ink jet printing method ejects a solution material by using a printing nozzle without depositing an organic material composed of a powder. Because it is directly sprayed on the desired part, there is almost no material to be discarded, and the efficiency is excellent. Since the deposition process can be omitted, the production process can be reduced and the process time can be drastically reduced.

On the other hand, as the insulating material constituting the bank layer, a hydrophobic binder such as an acrylic binder such as photoacryl is used. The following problems have arisen when the above-described insulating material is used as the bank layer of the organic light emitting diode display device.

As shown in FIG. 1, a bank layer made of a hydrophobic insulating material partially overlapped with the lower electrode is patterned using a photoresist process. In the state in which the bank layer is formed, a material made of liquid ink is injected into the upper portion of the lower electrode between the bank layers using a nozzle, and then the solution is removed to form a light emitting diode made of an organic material layer. Incidentally, there is a slight tolerance between the nozzle for supplying ink and the panel in which the lower electrode and the bank layer are formed. Therefore, when the nozzle approaches the lower electrode and the panel on which the bank layer is formed to eject the ink, scratches are generated on the upper surface of the bank layer while the nozzle contacts the bank layer protruding from the upper surface.

When the bank layer is made of a hydrophobic insulating material, the ink provided through the nozzle is injected not only into the region where the light emitting diode is formed, but also onto the upper part of the bank layer formed with scratches. Since the ink is injected into the scratch-formed bank layer, the thickness (H2) of the ink layer in the light-emitting diode forming region adjacent to the scratch-formed bank layer is smaller than the thickness H2 of the ink layer And the thickness H1 of the substrate W1. Since the organic material layer including the light emitting material is not uniformly formed in the light emitting diode, there is a difference in the light emission luminance and color depending on the region, thereby reducing the reliability of the process and increasing the defect rate. Further, it is difficult to realize high-quality images such as blurred images mixed with inks of different colors in adjacent pixel regions while organic matters flow into the bank layer as well.

2, the refractive index (n2 = 1.65) of the hydrophobic bank layer partially overlapped with the lower electrode in the conventional organic light emitting diode display device has an average refractive index n1 of 1.7 to 1.8 ).

Total reflection is a phenomenon in which, when light enters a medium having a small refractive index from a medium having a high refractive index, light is incident at a certain angle (total reflection critical angle) or more, and the light is reflected without being refracted at the interface. The larger the difference in the refractive index between the two media, the smaller the total reflection critical angle and the more the total reflection occurs. However, since the refractive index (n1) of the light emitting layer and the refractive index (n2) of the bank layer constituting the light emitting diode constituting the light emitting diode in the conventional organic light emitting diode device do not substantially differ, most of the light emitted from the light emitting layer to the bank layer, And is emitted to the non-light emitting region. There has been a problem that light emitted to the light emitting region is reduced while the out-coupled light efficiency of the light emitting diode and the organic light emitting diode display is reduced and the light emission luminance is lowered.

It is an object of the present invention to provide a nanoparticle having a low refractive index and excellent recovery characteristics against external stress, and an insulating film and an organic light emitting diode display device including the nanoparticle with improved process reliability.

Another object of the present invention is to provide an insulating film and an organic light emitting diode display device capable of improving light extraction efficiency and light emission luminance and reducing power consumption by inducing a reduction in dielectric constant.

According to one aspect of the present invention, there is provided a nanoparticle in which adjacent porous particles or hollow particles are connected via a disulfide group.

In one example, the porous particles and hollow particles can be inorganic particles, such as polyimide (PI) and the like organic particles and / or silica (SiO ₂₎ and / or titania (TiO _2).

According to another aspect of the present invention, there is provided an insulating film in which the nanoparticles are dispersed in a binder.

According to another aspect of the present invention, there is provided an organic light emitting diode display device in which an insulating film in which the nanoparticles are dispersed in a binder is used as a bank layer.

In the nanoparticles of the present invention, hollow particles or porous particles are connected through a disulfide group.

The refractive index of the insulating film obtained by dispersing the nanoparticles of the present invention in a binder is low. Therefore, when the insulating layer in which nanoparticles are dispersed is applied to the bank layer of the organic light emitting diode display device, the refractive index of the bank layer according to the present invention is greatly reduced compared to the refractive index of the organic light emitting layer constituting the light emitting diode. Therefore, the light emitted from the light emitting diode to the bank layer is totally reflected at the interface between the light emitting diode and the bank layer, and is emitted to the light emitting region. Since the light extraction efficiency in the light emitting region is increased, the light emission luminance of the light emitting diode display device can be greatly improved.

In addition, since the dielectric constant of the insulating film to which the nanoparticles of the present invention is applied is also reduced in proportion to the degree of lowering the refractive index of the insulating film, the parasitic capacitance in the bank layer composed of the insulating film manufactured according to the present invention is reduced. An organic light emitting diode display device capable of reducing power consumption by applying an insulating film in which nanoparticles according to the present invention are dispersed to a bank layer can be manufactured.

The nanoparticles of the present invention also have a disulfide group capable of implementing a self-healing mechanism by light irradiation. Therefore, if the insulating film containing the nanoparticles of the present invention is damaged due to environmental factors, the damage can be recovered immediately.

Therefore, when the insulating layer in which nanoparticles are dispersed is used as a bank layer of an organic light emitting diode display device, damage such as scratches generated in the bank layer due to contact with a nozzle that ejects ink during a solution process using the inkjet printing method, . As a result, the organic light emitting layer made of the material injected from the nozzles can be uniformly stacked over the entire light emitting region. Thus, the reliability of the process can be improved, the defective rate can be lowered, and a high-quality image can be secured.

FIG. 1 is a schematic diagram showing a problem caused by a scratch on a bank layer used in a conventional organic light emitting diode display.
FIG. 2 is a schematic diagram illustrating a problem of degrading light extraction efficiency when a bank layer used in a conventional organic light emitting diode display device has a refractive index similar to that of a light emitting diode.
3 is a cross-sectional view schematically showing an insulating film in which nanoparticles are dispersed according to an exemplary embodiment of the present invention.
4 is a schematic diagram showing a state in which damage due to external stress is released through a self-healing mechanism in an insulating film in which nanoparticles are dispersed according to an exemplary embodiment of the present invention.
FIG. 5 is a cross-sectional view schematically showing an organic light emitting diode display device in which an insulating film in which nanoparticles are dispersed is applied to a bank layer according to an exemplary embodiment of the present invention.
FIG. 6 is a schematic diagram showing a state in which a scratch is extinguished by a self-healing mechanism when an insulating film in which nanoparticles are dispersed is applied to a bank layer according to an exemplary embodiment of the present invention.
FIG. 7 is a graph showing a state in which the refractive index is lower than that of the light emitting diode when the insulating layer in which nanoparticles are dispersed is applied to the bank layer according to the exemplary embodiment of the present invention, so that light emitted from the light emitting diode is totally reflected, Fig.
8 is a TEM (transmission electron microscopy) photograph of hollow polyimide (PI) nanoparticles synthesized according to an exemplary embodiment of the present invention.
9 is a graph showing Raman spectroscopic results of hollow polyimide (PI) nanoparticles connected through a disulfide group in accordance with an exemplary embodiment of the present invention. A disulfide group connecting the adjacent porous particles and a thiol group located at the end of the porous particles are present at the same time.
FIG. 10 is a photograph of an insulating film prepared according to an exemplary embodiment of the present invention, the state before and after irradiation of visible light by scanning electron microscope (SEM). The scratches formed before the visible light irradiation disappear by the self-healing mechanism after the visible light irradiation.
FIG. 11 is an image transmitted through a pixel (left side) of a light emitting element panel in which an insulating film manufactured according to an exemplary embodiment of the present invention is applied to a bank layer and a pixel (right side) after ink is injected by an inkjet printing method. No scratch was generated in the bank layer adjacent to the light emitting element formation region where the ink was injected, and the ink was injected only into the light emitting element.
12 is an image transmitted through a pixel (left side) of a light emitting element panel in which an insulating film manufactured according to a comparative example is applied to a bank layer and a pixel (right side) after ink is injected by an inkjet method. Scratches were generated in the bank layer adjacent to the light emitting element formation region, and color mixing occurred as the ink flowed into the bank layer.

Hereinafter, the present invention will be described with reference to the accompanying drawings where necessary.

[Nanoparticles and insulating films]

The nanoparticles according to the present invention are connected to adjacent porous particles or hollow particles through a disulfide group. Since it contains porous particles or hollow particles, the refractive index and permittivity are low. In addition, the disulfide group has a self-healing mechanism while repeating decomposition and bonding by light irradiation.

In one exemplary embodiment, the nanoparticles can be connected to adjacent porous or hollow particles through a disulfide group, which nanoparticles can be represented by the following formula (1). In another embodiment, the nanoparticles may have a cluster structure in which a plurality of adjacent porous or hollow particles are connected through a plurality of disulfide groups, which nanoparticles may be represented by the following formula (2).

Formula 1

(2)

(Wherein A represents a porous particle or hollow particle, R represents a C1-C10 alkylene group or a thiuram group represented by the following formula (3)

(3)

(Wherein R < ₁ > is a C1 to C20 alkyl group, the nitrogen atom is linked to the porous or hollow particles, and the carbon atom is connected to the disulfide group)

In the formulas (1) and (2), the porous particles or the hollow particles (A) are bonded to the disulfide group (-S-S-) through the linking group (R). The self-healing reactivity and the light absorbing region of the nanoparticles according to the present invention are controlled according to R, which is a linking group for bonding porous particles or hollow particles (A) to disulfide groups (S-S). For example, nanoparticles according to the present invention can induce a self-healing response by absorption of visible light.

In one exemplary embodiment, the porous particles or hollow particles (A) may be selected from the group consisting of polyimide (PI), silica (SiO ₂ ), titania (TiO ₂ ), and combinations thereof.

For example, in order to produce porous or hollow particles of an organic component such as polyimide (PI), a porous or hollow inducing component may be reacted with the starting material for the synthesis of the polyimide. Polyimide (PI) is obtained by the condensation reaction of dianhydride and diamine. The polyimide component, which is one example of a porous or hollow particle, can be a transparent material or an opaque material.

The anhydrides that can be used to synthesize porous or hollow polyimides (PI) include pyromellitic dianhydride (PMDA), biphenyl-3,3 ', 4,4'- tetracarboxylic acid dianhydride (BPDA), 4,4'-oxydiphthalic anhydride (ODPA), benzophenone-3,3 ', 4,4'-tetracarboxylic acid dianhydride (benzophenonoe- 3 ', 4,4'-tetracarboxylic acid dianhydride (BTDA), diphenylsulfon-3,3', 4,4'-tetracarboxylic acid dianhydride; DSDA), 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (6FDA), 1,2,4,5-cyclobutanetetracarboxylic acid dianhydride (1 , 2,4,5-cyclobutane tetracarboxylic dianhydride (CBDA), 1,2,4,5-cyclohexane tetracarboxylic dianhydride (CHDA), 4,4'-bisphenol A 4,4'-bisphenol A dianhydride (BPADA), 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid 1,2-dicarboxylic anhydride (DTDA), bicyclic [2.2.2] oct-7-en-2-dicarboxylic anhydride , 3,5,6-tetracarboxylic dianhydride (BCDA), 5- (2,5-dioxotetrahydrofuryl) bicyclo [2.2.2] oct- ) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride (5- (2,5-Dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride; DOMDA), and ethylene diamine tetraacetic dianhydride (EDTE), benzoquinonetetracarboxylic dianhydride, and naphthalenetetracarboxylic dianhydride.

Meanwhile, diamines which can be used for synthesizing the porous or hollow polyimide (PI) include p-phenylene diamine (PPD), m-phenylene diamine (MPD), 3, 4,4'-oxydianiline (3,4-ODA), 4,4'-oxydianiline (4,4-ODA), biphenyl diamine ), 2,2'-bis (trifluoromethyl) -4,4'-biphenyldiamine (TFMB or TFB), 2,2'- Bis [4- (4-aminophenoxy) phenyl] propane (BAPP), 4,4'-methylene diamine MDA), cyclohexyl diamine (CHDAM), diaminobenzene cyanide (DABN), 3,4'-oxydiamine (3,4'-DPE), 4 , 4'-diamino bozo phenon, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 4-hydroxyphenyl) hexafluoropropane; BAHFP), 2.2 Bis (4- (4-aminophenoxy) phenyl] hexafluoropropane; 6FBAPP)

(3-aminophenoxy) benzene, m-BAPB), 4,4'-bis (4-aminophenoxy) biphenyl 4-aminophenoxy biphenyl (p-BAPB), 2,2-bis (3-aminophenyl) hexafluoropropane (BAPF), bis [4- 4- (4-aminophenoxy) phenyl] sulfone, m-BAPS), bis [4- aminophenoxy) phenyl] sulfone (BAPS), 1,4-bis (4-aminophenoxy) benzene, TPE-Q, 2,2- Aminophenyl) sulfone (p-BAPS), bis (3-aminophenyl) sulfone (APS) , m-xylylenediamine (m-XDA), p-xylylenediamine (p-XDA), 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane 2-bis (3-amino-4-methylphenyl) hexafluoropropane (BAMF), 4,4'-diaminooctafluorobiphenyl enyl), 3,3'-dihydroxybenzidine, 2,2'-ethylenedianilin, 2,2 ', 5,5'-tetrachloro Bis (3-aminophenyl) methanone, 2,7-diaminofluorene, 2,7-diaminofluorene, 2-chloro-p-phenylenediamine, 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, 1,3- Bis (4-aminophenyl) cyclohexane, 9,9-bis (4-aminophenyl) fluorene, ) fluorine, 5- (trifluoromethyl) -1,3-phenylenediamine, 4,4'-methylenebis (2-methylcyclohexylamine) ( 4-methylenebis (2-methylcyclohexylamine), 4-fluoro-1,2-phenylenediamine, 1,3-bis (aminomethyl) cyclohexane , 3-bis (aminomethyl) cyclohexane; m-CHDA), 1,4-bis (aminomethyl) cyclohexane, p-CHDA, 2,2-bis [4- (4-aminophenoxy) Bis (trifluoromethyl) benzidine, MDB (2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 6FBAPP), 2,2'- ), 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, bis (4-aminophenyl) sulfide, 4 , 4'-SDA).

The polyamic acid (PAA), which is a precursor, is condensed by condensation reaction of the above-mentioned anhydride monomer and diamine anhydride, and a porous or porous polyamic acid linked with a disulfide group by reacting a porous or pore- Can be obtained.

In one alternative embodiment, a solution in which a porous or pore-derived component (e.g., polyacrylic acid, polyvinyl pyrrolidone, polymetal methacrylate (PMMA) and / or lithium chloride, etc.) is dissolved, an anhydride and a diamine , A solution in which a precursor substance having a thiol group is dissolved is reacted to obtain an intermediate in which an adjacent porous or hollow polyamic acid is linked via a disulfide group.

The porous or porous polyamic acid linked via a disulfide group is subjected to a chemical imidization process and a heat treatment process to synthesize nanoparticles in which adjoining hollow or porous polyimide particles are connected via a disulfide group. In the chemical imidization process, a dehydrating agent such as acetic anhydride and a dehydrating agent such as pyridine, isoquinoline, β-picoline (tertiary amines such as β-picoline and pyridine, etc.) are added to the porous or hollow polyamic acid solution The thermal imidization method is a method in which a porous or hollow polyamic acid solution which is a precursor is heat-treated at a temperature of about 250 to 300 DEG C and thermally imidized. Optionally, a chemical imidization method and thermal imidization The nanoparticles of the present invention in which the porous or hollow polyimide particles are connected via the disulfide group can be synthesized.

On the other hand, porous or hollow silica (SiO ₂ ) particles or titania (TiO ₂ ) particles can be used which are commercially available. After adding a substance having a thiol group to porous or hollow silica particles or titania particles, the porous nanoparticles of the present invention in which adjacent porous or hollow silica or titania particles are connected via a disulfide group through a sol- Can be synthesized.

Since the nanoparticles according to the present invention contain porous or hollow particles, the refractive index is lower than that of non-porous particles or solid particles, and the dielectric constant is also decreased in proportion to the refractive index. Since the refractive index of the insulating layer to which the nanoparticles of the present invention is applied is lower than the refractive index of the organic layer constituting the light emitting diode, the light emitted from the organic layer can be totally reflected at the interface of the insulating layer in which nanoparticles are dispersed. In addition, by adopting an insulating film having a low dielectric constant, the parasitic current can be reduced and the power consumption can be lowered. In addition, the nanoparticles of the present invention comprise disulfide groups with self-healing properties. Therefore, even if a defect such as damage of an insulating film in which nanoparticles are dispersed occurs due to environmental factors or the like, the damage can be quickly healed by light irradiation.

Next, the insulating film in which nanoparticles according to the present invention are dispersed will be described first. 3 is a cross-sectional view schematically showing an insulating film in which nanoparticles are dispersed according to an exemplary embodiment of the present invention. As shown in FIG. 3, the insulating film 100 includes a binder 110 and nanoparticles 120 dispersed in the binder 110.

The binder 110 may be selected from the group consisting of a polyimide (PI) resin, a polysiloxane resin, a poly (meth) acrylate resin, and combinations thereof. The term (meth) acrylate is used herein to mean both acrylate and methacrylate. For example, the binder 110 may be a polyimide (PI) -based resin and / or a polysiloxane-based resin having excellent heat resistance.

In order to produce the insulating film 100 in which the nanoparticles 120 are dispersed in the binder 110, a binder precursor, nanoparticles 120, an organic solvent and, if necessary, a photopolymerization initiator, a photosensitive compound, a crosslinking agent, May be used as the liquid photosensitive composition. The liquid photosensitive composition is coated on the base material and a photolithography process is performed so that the insulating film 100 in which the nanoparticles 120 are dispersed in the binder 110 can be manufactured.

Examples of the organic solvent used in the liquid photosensitive composition include alcohols, ethylene glycol alkyl ether propionates; Propylene glycol alkyl ether acetates such as ethylene glycol monoalkyl ethers, diethylene glycol alkyl ethers and propylene glycol methyl ether acetate (PGMEA), propylene glycol alkyl ether propionates, propylene glycol monoalkyl ethers, dipropylene glycol Alkyl ethers, butylene glycol monomethyl ether, dibutylene glycol alkyl ethers, gamma butyrolactone, and the like.

The photopolymerization initiator may be an acetophenone photopolymerization initiator, a benzophenone photopolymerization initiator, a thioxanthone photopolymerization initiator, a benzoin photopolymerization initiator, or a triazine photopolymerization initiator.

As the photosensitive compound, a 1,2-quinonediazide compound can be used, and for example, a compound obtained by reacting a phenol compound with a naphthoquinone diazide sulfonic acid halogen compound can be used. For example, the 1,2-quinonediazide compound may be 1,2-quinonediazide 4-sulfonic acid ester, 1,2-quinonediazide 5-sulfonic acid ester, or 1,2-quinonediazide 6-sulfonic acid ester Can be used.

The crosslinking agent forms a crosslinked structure with the resulting binder, for example, a melamine crosslinking agent can be used. The melamine-based crosslinking agent may be a condensation product of urea and formaldehyde, a condensation product of melamine and formaldehyde, or a methylol urea alkyl ether or methylolmelamine alkyl ether obtained from an alcohol. For example, as condensation products of urea and formaldehyde, monomethylol urea, dimethylol urea and the like can be used. As the condensation products of melamine and formaldehyde, hexamethylol melamine may be used. In addition, partial condensation products of melamine and formaldehyde may be used.

The photoacid generator used in the case of forming a negative type insulating film may be an ionic photoacid generator such as a gesulfonium salt or an iodonium salt, a sulfonic acid group-containing group, a N-sulfonyloxyimide group, Nitrobenzyl sulfonate type, sulfone type, glyoxime type, or triazine type can be used.

For example, when the binder 120 is a polyimide (PI) -based resin, the anhydride and diamine used for synthesizing the porous or hollow polyimide particles as the binder precursor may be used as a starting material. A liquid photosensitive composition dispersed in a polyamic acid precursor obtained by reacting an anhydride with a diamine and a nanoparticle (120) equivalent organic solvent is coated on a substrate. The coating method is not limited, and roll coating, spin coating, deep coating, flow coating, and spray coating methods can be used . Then, a patterned insulating film 100 can be manufactured by performing a photolithography process.

The photolithography process for producing an insulating film in which nanoparticles are dispersed in a polyimide (PI) -based binder is a process in which preliminary curing (pre-baking) of a liquid photosensitive composition applied in the form of a dispersion of a polyamic acid precursor and nanoparticles in an organic solvent , Soft-baking), exposure and development processes and final curing (post-baking, hard-baking) processes and additional curing processes.

For example, the preliminary curing may be performed at a temperature of 80 to 120 ° C for 3 to 15 minutes, and a light source such as visible light, ultraviolet light, electron beam, and X-ray may be used in the exposure process. For example, ultraviolet (UV) light having a wavelength band of approximately 200 to 400 nm, preferably 300 to 400 nm may be used as the light source used in the exposure process. An exposure mask (photomask) may be disposed to form an appropriate pattern, wherein the photoresist comprising the photosensitive composition may be of a negative type or of a positive type. Non-limiting examples of light sources used in the exposure process include mercury vapor arc, carbon arc xy (Xe) arc.

In the development step, an aqueous alkali solution, specifically, alkalis such as sodium hydroxide, potassium hydroxide, and sodium carbonate; Primary amines such as ethylamine and n-propylamine; Secondary amines such as diethylamine and n-propylamine; Tertiary amines such as trimethylamine, methyldiethylamine, dimethylethylamine and triethylamine; Alcohol amines such as dimethylethanolamine, methyldiethanolamine and triethanolamine; Or an aqueous solution of a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide (TMAH). After the developing process, cleaning is performed using ultrapure water to remove unnecessary portions to form a pattern, and final curing is performed in a heating device such as an oven or a hot-plate to finally form the patterned insulating film. For example, the present curing may be carried out at a temperature of 110 to 150 ° C for 30 to 90 minutes, and if necessary, an additional curing process may be carried out at a temperature of 200 to 250 ° C for 20 to 40 minutes.

On the other hand, when the poly (meth) acrylate resin is used as the binder 100, it is preferable to use a liquid phase composition comprising a photoreactive component which can be cured by irradiation with an appropriate light source, a photopolymerization initiator, The photosensitive composition may be coated on the substrate and a photolithography process using photocuring may be performed. Here, the photoreactive component may be at least one selected from the group consisting of a C1 to C20 alkyl (meth) acrylate monomer / oligomer, a C2 to C20 alkenyl (meth) acrylate monomer / oligomer, a C1 to C20 alkoxy (meth) acrylate monomer / oligomer, (Meth) acrylate monomer / oligomer, C5 to C20 aryl (meth) acrylate monomer / oligomer, C5 to C8 alkoxyalkyl (meth) acrylate monomer / oligomer, epoxy But are not limited to, acrylate-based monomers / oligomers, allylalkoxylate-based monomers / oligomers. Photocuring can be carried out by irradiating light (using a UV lamp or an LED lamp) with a light intensity of approximately 1000 to 5000, preferably 2500 to 4000 mJ / cm 2, and can be performed for several seconds.

On the other hand, when the polysiloxane resin is used as the binder 110, the liquid photosensitive composition to which the siloxane monomer and / or the siloxane oligomer as the reactive component constituting the main chain of the siloxane resin, the organic solvent and the above- After the coating, a photolithography process using thermosetting can be performed. For example, thermal curing for preliminary curing can be carried out using a hot plate and can be carried out at a temperature of about 80 to 150 DEG C, preferably 100 to 120 DEG C for 5 to 20 minutes.

As the silanol monomer / oligomer which is a precursor substance for synthesizing the polysiloxane-based resin, ethylenically unsaturated alkoxysilane or ethylenically unsaturated acyloxysilane can be mentioned. Examples of the monomer / oligomer having a siloxane group include a siloxane monomer / oligomer having a linear siloxane group, a cyclosiloxane monomer / oligomer, a tetrahedral siloxane monomer / oligomer, and a monomer / oligomer having a silsesquioxane structure. When a silsesquioxane monomer / oligomer having a silsesquioxane structure is used, it is possible to form a polyhedral oligomeric silsesquioxane (POSS) having a ladder-type or cage-type structure excellent in heat resistance, It may be preferable to have a unit structure of oxane.

In one exemplary embodiment, the nanoparticles 120 of the present invention may be added in an amount of 1 to 50 wt%, preferably 5 to 40 wt%, in the insulating film 100. When the content of the nanoparticles 120 is less than the above-mentioned range, it is difficult to expect a reduction effect of the refractive index and the dielectric constant, and the self-healing mechanism may be limited. When the content of the nanoparticles 120 exceeds the above-mentioned range, the pattern characteristic of the insulating film 100 may be deteriorated.

As described above, the nanoparticles 120 according to the present invention are connected to adjacent porous or hollow particles through one or more disulfide groups. Since the disulfide group has a self-healing mechanism by light irradiation, the nanoparticles 120 of the present invention can emit damage to external stress through a self-healing mechanism when applied to the insulating layer 100. [ This will be described with reference to FIG. 3 and FIG.

As shown in these drawings, when stress is applied to the insulating film 100, disulfide groups of the nanoparticles 120 are dissociated (or separated), and temporary defects are generated in the insulating film 100. If such defects are not cured, the defects grow and damage such as scratches to the insulating film 100 occurs.

However, in the present invention, since the disulfide group is regenerated by visible light, growth and accumulation of defects due to accumulation in stress are prevented. That is, since the insulating film 100 of the present invention has a self-healing property by reversible reaction with light, it is possible to prevent the insulating film 100 from being permanently damaged due to a collision with a mechanical part or the like, .

Also, as described above, since the nanoparticles 120 according to the present invention include porous or hollow particles, the refractive index and dielectric constant of the insulating film 100 can be lowered. Thus, as will be described later, the total reflection in the insulating film 100 can be induced, and the parasitic current can be reduced.

[Organic light-emitting diode display device]

Next, an organic light emitting diode display device in which an insulating film in which nanoparticles according to the present invention are dispersed is applied as a bank layer will be described. FIG. 5 is a cross-sectional view schematically showing an organic light emitting diode display device in which an insulating film in which nanoparticles are dispersed is applied to a bank layer according to an exemplary embodiment of the present invention.

5, the organic light emitting diode display 200 according to the present invention includes a first substrate 201 constituting an array substrate, a second substrate 202 facing the first substrate 201, And are joined together to form a display panel. The first substrate 201 and the second substrate 202 may be a glass substrate, a thin flexible substrate, or a polymer plastic substrate. For example, the flexible substrate may be formed of a material such as polyethersulfone (PES), polyethylenenaphthalate (PEN), polyimide (PI), polyethylene terephthalate (PET) and polycarbonate As shown in FIG. The first substrate 201 on which the light emitting diodes E on which the driving thin film transistor Tr and the organic light emitting layer 263 are formed is an array substrate. The first substrate 201 includes a second substrate (Not shown).

A light shielding film 210 is disposed between the first substrate 201 and the conductive wiring and / or the conductive electrode disposed on the first substrate 201. A plurality of wirings and electrodes constituting the array panel are made of a conductive material having high reflectance. A light shielding film 210 is formed on the first substrate 201 constituting the array panel to prevent an external light source (external light) from being reflected by these conductive materials and lowering the visibility. By employing the light shielding film 210, the external light source (external light) is prevented from entering the conductive electrode and / or the conductive wiring formed on the array panel of the organic light emitting diode display device 200. In addition, it is possible to prevent the semiconductor layer 220 constituting the driving thin film transistor Tr from being deteriorated by external light.

The light shielding film 210 is formed by performing a photolithographic process on a photosensitive composition composed of a black colorant, a binder in which a black colorant is dispersed, a photosensitive agent, a solvent, and a dispersant adsorbed to a black colorant, As shown in FIG. The light shielding film 210 may be formed on the first substrate 201 with a thickness of, for example, 350 to 2000 nm.

A buffer layer 212 is disposed on the upper portion of the light shielding film 210. Buffer layer 212, but may be composed of an inorganic insulating material such as silicon oxide (SiO ₂₎ or silicon nitride (SiNx), may be deposited to a thickness of approximately 500 to 2000 Å, but the invention is not limited to this.

A plurality of electrodes, wiring, an organic film, and / or an inorganic film constituting the array panel are disposed on the buffer layer 212. Specifically, the array panel includes a light-shielding film 210 and a driving thin film transistor Tr, a switching thin film transistor (not shown), a light-emitting diode (LED), and the like, which are positioned above the buffer layer 212 and are driving elements for controlling the operation of the light- (Not shown), a data wiring (not shown), and a power wiring (not shown).

A semiconductor layer 220 is formed on the buffer layer 212. For example, the semiconductor layer 220 may be formed of a material such as low temperature polysilicon (LTPS) or amorphous silicon (a-Si) or an oxide semiconductor of IGZO (indium gallium zinc oxide) . At this time, as the oxide semiconductor, at least one material selected from the group consisting of germanium (Ge), tin (Sn), lead (Pb), indium (In), titanium (Ti), gallium (Ga) And may be made of a material in which silicon (Si) is added to an oxide semiconductor containing zinc (Zn). For example, the semiconductor layer 220 may be formed of a silicon-indium zinc oxide (Si-InZnO, SIZO) to which a silicon ion is added to an indium-zinc-composite oxide (InZnO). Alternatively, the semiconductor layer 220 may be made of polycrystalline silicon. In this case, impurities may be doped on both edges of the semiconductor layer 220.

The semiconductor layer 220 includes an active region 222a for forming a channel through which electrons move between a source electrode 242 and a drain electrode 244 which will be described later and a source region 242 on both sides of the active region 222a. And a source region 222b and a drain region 222c which are in contact with the drain electrode 244, respectively.

A gate insulating layer 230 made of silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the semiconductor layer 220. A gate electrode 232, a gate wiring (not shown) extending in a first direction, and a first capacitor electrode (not shown) are formed on the gate insulating layer 230 in correspondence with the active region 222a of the semiconductor layer 220, Can be formed. A gate wiring (not shown) may extend along the first direction, and a first capacitor electrode (not shown) may be connected to the gate electrode 232. Although the gate insulating layer 230 is formed on the entire surface of the first substrate 201 in the drawing, the gate insulating layer 230 may be patterned to have the same shape as the gate electrode 232.

The gate electrode 232 is typically formed of a low-resistance metal material such as aluminum (Al), an Al alloy (e.g., AlNd), tungsten (W), copper (Cu), a copper alloy, molybdenum ), Silver (Ag), silver alloy, gold (Au), gold alloy, chromium (Cr), titanium (Ti), titanium alloy, molybdenum tungsten (MoWi), molybdenum titanium (MoTi) And copper / moly titanium (Cu / MoTi).

An interlayer insulating film 240 is formed on the entire surface of the first substrate 201 on the entire surface of the gate electrode 232 and the gate wiring (not shown). The interlayer insulating layer 240 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) to enhance the contact property with the semiconductor layer 220 or may be formed of benzocyclobutene, photo-acryl). The gate insulating layer 230 and the interlayer insulating layer 240 are formed on the first and second semiconductor layer contacts 222 and 222c that respectively expose the source and drain regions 222b and 222c located on both sides of the active region 222a of the semiconductor layer 220, And a hole 234. Alternatively, when the gate insulating film 230 is patterned in the same shape as the gate electrode 232, the first and second semiconductor layer contact holes 234 are formed only in the interlayer insulating film 240.

Next, first and second semiconductor layer contact holes 234 are formed in the upper part of the interlayer insulating film 240 including the first and second semiconductor layer contact holes 234 of the non-emission region NA, A source electrode 242 and a drain electrode 244 which are in contact with the source and drain regions 222b and 222c, respectively, are formed. The source and drain electrodes 242 and 244 are made of a conductive material such as a metal.

Although not shown, a color filter that absorbs red (R), green (G), blue (B), and white (not shown) light may be located on the interlayer insulating layer 240 of the light emitting area AA.

A planarizing film 246 is formed on the entire surface of the first substrate 201 above the source and drain electrodes 242 and 244. The planarization film 246 has a drain contact hole 247 for exposing the drain electrode 244. The planarizing film 246 is made of an organic insulating material such as benzocyclobutene or photo-acryl and has a flat upper surface.

The semiconductor layer 220 includes source and drain electrodes 242 and 244 and source and drain regions 222b and 222c that are in contact with the electrodes 242 and 244. The gate insulating film 230 and the gate electrode 232 constitute a driving thin film transistor Tr. In the drawing, the driving thin film transistor Tr is illustrated as a coplanar structure in which a gate electrode 232, a source electrode 242, and a drain electrode 244 are disposed on a semiconductor layer 220. Alternatively, the driving thin film transistor Tr may have an inverse staggered structure in which a gate electrode is positioned below the semiconductor layer and a source electrode and a drain electrode are located above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon or an oxide semiconductor.

On the other hand, a data line (not shown) extending along the second direction intersecting the gate line (not shown) and defining each pixel region PA is formed on the interlayer insulating layer 240 outside each pixel region PA. A power supply wiring (not shown) and a second capacitor electrode (not shown) are formed. A power supply wiring (not shown) for supplying a high potential voltage is spaced apart from the data wiring (not shown). The second capacitor electrode (not shown) is connected to the drain electrode 244 and overlaps the first capacitor electrode (not shown), thereby forming an interlayer insulating film 240 between the first and second capacitor electrodes as a dielectric layer, It accomplishes. Though not shown in the drawing, a switching thin film transistor (not shown) has the same structure as the driving thin film transistor Tr and is connected to the driving thin film transistor Tr.

The light emitting diode E is located in the light emitting area AA that substantially displays an image on the planarizing film 246. [ The light emitting diode E has a first electrode 261 connected to the drain electrode 244 of the driving thin film transistor Tr. For example, the first electrode 261 may be an anode and supplies holes to the organic light emitting layer 263. The first electrode 261 is preferably formed of a conductive material having a high work function, for example, a transparent conductive oxide (TCO). For example, the first electrode 261 may be formed of indium-tin-oxide (ITO), indium-zinc-oxide (IZO), zinc- Tin-oxide. ≪ / RTI > In the case of a top emission type light emitting diode also referred to as a top emission type, a reflective layer (not shown) formed on the bottom surface of the first electrode 261 and configured to reflect light in a top surface direction .

The first electrode 261 is formed for each pixel region PA. The bank layer 300 is formed of the insulating layer according to the present invention between the first electrodes 261 formed for each pixel region PA2. That is, the first electrode 261 has a structure in which the bank layer 300 is divided into the pixel regions PA with the boundaries of the respective pixel regions PA.

An organic emission layer 263 is formed on the first electrode 261. The organic light emitting layer 263 expresses red (R), green (G), and blue (B) colors or represents white (W) for each pixel region PA. The organic light emitting layer 263 may be formed of a single layer made of a light emitting material. In order to increase the light emitting efficiency, a hole injection layer, a hole transport layer, an emitting material layer, And may be composed of multiple layers of an electron transport layer and an electron injection layer.

A second electrode 265 is formed on the entire surface of the organic light emitting layer 263. For example, the second electrode 265 may be a cathode and supplies electrons to the organic light emitting layer 263. The second electrode 265 may be made of a conductive material having a relatively small work function. For example, in the case of a light emitting diode of a bottom emission type, the second electrode 265 may have a good reflection characteristic such as aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag) Material. Alternatively, in the case of a top emission type light emitting diode, the second electrode 265 may be a two-layer structure in which a transparent conductive material is thickly deposited on a semi-transparent metal film on which a low work function metal material is deposited thinly .

When a predetermined voltage is applied to the first electrode 261 and the second electrode 265 in accordance with the selected signal, the light emitting diode E emits light having a positive polarity from the first electrode 261 to the second electrode 265 The injected electrons are respectively transported to the organic light emitting layer 263 to form excitons. When the excitons transit from the excited state to the ground state, light is emitted and emitted in the form of visible light. At this time, the light emitted from the organic light emitting layer 263 may be driven by the lower light emitting method toward the first electrode 261, or may be driven by the upper light emitting method toward the second electrode 265.

A second substrate 202, which is an encapsulation substrate for encapsulation, is provided on the driving thin film transistor Tr and the light emitting diode E. Here, the first substrate 201 and the second substrate 202 are provided with an adhesive (not shown) made of a sealant or a frit along the edge thereof. The first substrate 201 and the second substrate 202 202 are joined together to maintain the panel state. At this time, a vacuum state may be established between the first substrate 201 and the second substrate 202 which are separated from each other, or an inert gas atmosphere may be formed by being filled with an inert gas. In addition, although not shown, a polarizer may be disposed on the second substrate 202, and a cover window may be disposed on the polarizer (not shown) through an optically clear adhesive (OCA).

Although the display device 200 of FIG. 5 has been described and illustrated as having a second substrate 202 for encapsulation that is spaced apart from the first substrate 201, the second substrate 202 May be configured to contact the second electrode 265 provided on the uppermost layer of the first substrate 201 in the form of a film including an adhesive layer (not shown). As another modification of the embodiment of the present invention, a capping layer (not shown) may be formed by further providing an organic insulating layer or an inorganic insulating layer on the second electrode 265, May be used as an encapsulation film (not shown). In this case, the second substrate 202 may be omitted.

The bank layer 300 includes a binder 310 made of an inorganic insulating material, for example, a polyimide (PI) based resin, a poly (meth) acrylate based resin and / or a polysiloxane based resin, Adjacent porous or hollow particles include nanoparticles 320 connected through one or more disulfide groups. Accordingly, it is possible to remove the damage or defects occurring in the bank layer 300 according to the self-healing mechanism, and to lower the refractive index and the dielectric constant of the bank layer 300, which will be described.

FIG. 6 is a schematic diagram showing a state in which a scratch is extinguished by a self-healing mechanism when an insulating film in which nanoparticles are dispersed is applied to a bank layer according to an exemplary embodiment of the present invention. The bank layer 300 includes nanoparticles 320 having a disulfide group moiety having a self-healing function. Ink containing a material for forming the organic light emitting layer 263 (see FIG. 5) between the bank layers 300 is injected through the nozzles by a solution process using an inkjet printing method. The disulfide bonds are re-generated by the light irradiation even if the disulfide groups are disengaged due to damage or defects such as scratches occurring on the upper surface of the bank layer 300 due to the contact between the nozzle containing the ink and the bank layer 300, Damage or defects temporarily formed on the upper surface of the layer 300 are removed.

The ink layer including the material for forming the organic light emitting layer 263 (see FIG. 5) to be injected onto the first electrode 261 may be injected at the same height H in the light emitting diode forming region. Accordingly, the organic light emitting layer 263 (see FIG. 5) made of the light emitting material or the charge transfer material can be formed with a uniform thickness in the light emitting diode. As a result, uniform light emission luminance and hue can be ensured in the entire region of the light emitting diode, thereby improving the reliability of the process and reducing the defect rate. In addition, since the ink can not flow into the bank layer 300, images are mixed with other inks in the adjacent pixel region, so that the image is not blurred, and a high-quality image can be realized.

Meanwhile, FIG. 7 is a graph showing the relationship between the refractive index of the light emitting diode and the light extraction efficiency of the light emitting diode when the insulating layer having nanoparticles dispersed therein is applied to the bank layer according to the exemplary embodiment of the present invention. Fig.

As described above, the nanoparticles 320 constituting the bank layer 300 contain porous or hollow particles. For example, by setting the content of the nanoparticles to 10 wt% or more, the refractive index (n2) of the bank layer 300 can be adjusted to less than 1.5. On the other hand, the average refractive index n1 of the organic light emitting layer 263 (see FIG. 5) formed through the solution process between the bank layers 300 is approximately 1.7 to 1.8.

When light is incident on a medium having a large index of refraction (n1) and a index of refraction (n2) of less than a specific angle (total reflection critical angle), the light is totally reflected Reflection phenomenon. The refractive index n1 of the organic light emitting layer 263 (see FIG. 5), which is a medium through which light is incident, and the refractive index n2 of the bank layer 300, which is the opposite medium, The larger the difference, the smaller the critical angle of total reflection and the more the total reflection occurs.

The refractive index of the conventional bank layer and the refractive index of the organic layer are not greatly different from each other, and most of the light emitted from the organic layer to the bank layer is refracted without being totally reflected, and is emitted to the non-light emitting region (see FIG. On the other hand, since the refractive index of the bank layer 300 of the present invention including the porous or hollow particles 320 is much lower than the refractive index of the organic light emitting layer 263 (see FIG. 5), the organic light emitting layer layer and the bank layer 300 (I.e., the range of the total reflection critical angle is enlarged). Accordingly, when the bank layer according to the present invention is applied, the light partially refracted at the interface between the organic light emitting layer and the bank layer is totally reflected at the interface between the organic light emitting layer 263 (see FIG. 5) and the bank layer 300 Emitting region. As the amount of light emitted to the light emitting region increases, the out-coupled light efficiency of the light emitting diode E (see FIG. 5) and the organic light emitting diode display increases, and the light emission luminance also increases.

In addition, since the nanoparticles 320 having porous or hollow particles having a low refractive index are included, the dielectric constant of the bank layer 300 can be reduced, and the power consumption due to the parasitic capacitance can be prevented from increasing.

Hereinafter, the present invention will be described in more detail with reference to exemplary embodiments.

Synthetic example  One: Hollowness  Polyimide particles Disulfide group  Linked nanoparticle synthesis

Pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (4,4-ODA) at a molar ratio of 1: 1 were dissolved in N-methyl-2- (Solution 1) in which polyamic acid (PAA) in the form of poly (pyromellitic acid-co-4,4'-oxadianiline) was synthesized by reaction with N-methyl-2-pyrrolidone (NMP) .

A solution in which a hollow induction component mixed with NMP, polyacrylic acid (PAS1), polyvinyl alcohol (PVAL), and polyvinyl pyrrolidone (PVP) (Solution 2) were prepared. A solution (solution 3) in which cysteamine and 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (4,4' - (Hexafluoroisopropylidene) diphthalic anhydride) were mixed was prepared . Solution 3 (50 μl) was added to 10 ml of cyclohexane, and 100 μl of a mixture solution of Solution 1 and Solution 2 was added at room temperature, followed by vigorous stirring. Then, a mixture (1: 1, 100 쨉 l) of pyridine as an imidation catalyst and acetic anhydride as a dehydrating agent was further added thereto and reacted for 3 hours. After centrifugation, it was vacuum-dried and allowed to stand at 270 DEG C for 1 hour to complete the imidation reaction. A TEM photograph of the nanoparticles synthesized according to this synthesis example is shown in FIG. It was confirmed that hollow particles were generated. The results of the Raman spectroscopic analysis of the nanoparticles synthesized according to this synthesis example are shown in FIG. It was confirmed that a disulfide group and a thiol group coexisted to confirm that the hollow polyimide particles were connected to the adjacent hollow polyimide particles by disulfide groups.

Synthetic example  2: Porous silica ( SiO ₂ ) Particles Disulfide group  Linked nanoparticle synthesis

The commercially available porous silica particles were synthesized with disulfide group linked nanoparticles. 1 mL of hydrochloric acid, 60 mL of methanol, 1 mL of 3-mercaptopropyl trimethoxysilane (MTPS), and 3 g of porous silica particles were stirred in a round bottom flask at 60-120 ° C for 12-60 hours. Washed several times with methanol to remove unreacted material. The resulting precipitate was dissolved in 0.1 to 10 mL of THF (tetrahydrofuran), and then slowly added dropwise to 1 to 300 mL of acetonitrile. The mixture was crystallized at -20 to 0 ° C for more than 24 hours, and the resulting white powder was washed with acetone and then dried in a vacuum oven for at least 12 hours. Dispersed in a solvent, and then heated at 20 to 100 캜 to synthesize nanoparticles in which adjacent porous silica particles are linked by disulfide groups.

Synthetic example  3: Porosity Titania ( TiO ₂ ) Particles Disulfide group  Linked nanoparticle synthesis

The procedure of Synthesis Example 2 was repeated except that the porous titania particles were used as the porous particles in place of the porous silica particles to synthesize nanoparticles in which adjacent porous titania particles were linked by disulfide groups.

Example  One: Bank layer  Insulating film manufacturing

A bank layer insulating film in which 30 wt% of the hollow polyimide nanoparticles synthesized in Synthesis Example 1 were dispersed in a polyimide resin (refractive index: 1.65) was prepared. Negative-type polyimide resin (PIMEL (TM) BM-300, Asahi Kase) was used as a binder. A photosensitive composition prepared by mixing BM-300 and hollow polyimide nanoparticles was spin-coated on the substrate and soft-baked at 80 캜 for 30 minutes or more. In order to perform the photolithography process, a photomask was used, and after the UV light of the i-line was irradiated, the mask was removed and patterned. The development process was carried out using TMAH (tetramethylammonium hydroxide), post-baking was performed at 120 ° C, and then curing was performed at 230 ° C for 30 minutes to prepare a bank layer insulating film.

Example  2: Bank layer  Insulating film manufacturing

The procedure of Example 1 was repeated except that the hollow polyimide nanoparticles synthesized in Synthesis Example 1 were dispersed in the insulating film in an amount of 50% by weight, to prepare a bank layer insulating film.

Example  3: Bank layer  Insulating film manufacturing

The procedure of Example 1 was repeated except that the porous silica nanoparticles synthesized in Synthesis Example 2 were dispersed in the insulating film in an amount of 5% by weight, to prepare a bank layer insulating film.

Example  4: Bank layer  Insulating film manufacturing

The procedure of Example 1 was repeated except that the porous silica nanoparticles synthesized in Synthesis Example 2 were dispersed in the insulating film in an amount of 20% by weight, to prepare a bank layer insulating film.

Example  5: Bank layer  Insulating film manufacturing

The procedures of Example 1 were repeated except that the porous titania-based nanoparticles synthesized in Synthesis Example 3 were dispersed in the insulating film at 5 wt%, thereby fabricating a bank layer insulating film.

Example  6: Bank layer  Insulating film manufacturing

The procedure of Example 1 was repeated except that the porous titania-based nanoparticles synthesized in Synthesis Example 3 were dispersed in an insulating film at 20 weight%, thereby preparing a bank layer insulating film.

Experimental Example  One: Bank layer  Evaluation of Refractive Index of Insulating Film

In Examples 1 to 6, the refractive index of a bank layer insulating film in which porous or hollow particles were dispersed was measured. The measurement results are shown in Table 1 below. It can be seen that the refractive index of the bank layer insulating film containing the porous or hollow nanoparticles is greatly reduced as compared with the refractive index (1.65) of the polyimide-based binder. Therefore, when the insulating layer manufactured according to the present invention is used as a bank layer of an organic light emitting diode display device, efficient total reflection can be induced at the interface between the organic light emitting layer and the bank layer, and light extraction efficiency and light emission luminance of the light emitting diode can be improved It was expected to be possible.

Table 1: Evaluation of refractive index

Example  7: Fabrication of LED panel

According to Example 1, a light emitting diode panel in which an insulating film having 30 wt% of hollow polyimide nanoparticles dispersed in a polyimide binder was applied as a bank layer was produced. An insulating film in which hollow nanoparticles were dispersed in a polyimide-based binder so as to overlap the ITO electrode was formed as a bank layer, and an ink was injected by an ink-jet printing method using a nozzle to fabricate a light emitting diode panel. Then, visible light was irradiated using an LED lamp (400 to 700 nm).

Comparative Example  1: Fabrication of LED panel

The procedure of Example 7 was repeated to fabricate a light emitting diode panel, except that an insulating film made only of a negative type polyimide binder was applied to the bank layer.

Experimental Example  2: Evaluation of light emitting diode panel

Whether or not the bank layer was scratched before and after the LED lamp was irradiated onto the light emitting diode panel manufactured in Example 7 was evaluated. An SEM image showing the evaluation result is shown in Fig. Scratches were generated before the visible light irradiation (left side of FIG. 10), but it was confirmed that the scratches were removed by self-healing of the disulfide groups contained in the nanoparticles after visible light irradiation (right side of FIG. 10).

That is, after the visible light irradiation, scratches are removed from the bank layer of the light emitting device panel manufactured in Example 7 to have a normal pixel structure in which the light emitting device region and the bank layer region are clearly distinguished (see the left side of FIG. 11). Accordingly, it can be seen that when ink is injected by the ink-jet printing method, ink is injected only into the light emitting element region (see the right side of FIG. 11). On the other hand, scratches occurred in the bank layer of the light emitting device panel manufactured according to Comparative Example 1, scratches were not removed even when visible light was irradiated, and the light emitting device region and the bank layer region were clearly separated (See the left side of Fig. 12). It was confirmed that the ink was also mixed into the bank layer adjacent to the light emitting element region when the ink was injected by the inkjet printing method (see the right side of Fig. 12).

Experimental Example  3: Light emitting diode panel luminance evaluation

Five light emitting diode panels fabricated in each of Example 7 and Comparative Example 1 were fabricated and the luminescence brightness was measured. The measurement results are shown in Table 2 below. It was confirmed that the light extraction efficiency was improved in the light emitting diode manufactured in Example 7, and the luminance was improved by an average of 13%.

Table 2: Evaluation of luminance

Although the present invention has been described based on the exemplary embodiments and examples of the present invention, the present invention is not limited to the technical ideas described in the above embodiments and examples. Those skilled in the art will appreciate that various modifications and changes may be made without departing from the spirit and scope of the present invention as defined by the appended claims. It is apparent, however, that the appended claims are intended to cover all such modifications and changes as fall within the true scope of the invention.

100, 300: insulating film (bank layer)
110, 310: binder
120, 320: nanoparticles
200: Organic Light Emitting Diode Display
201: first substrate 202: second substrate
E: light emitting diode Tr: driving thin film transistor
AA: light emitting region NA: non-light emitting region
PA: pixel area

Claims (9)

Wherein the adjacent porous particles or hollow particles are connected via a disulfide group.
The method according to claim 1,
Wherein the nanoparticle is represented by the following formula (1) or (2).
Formula 1

(2)

(Wherein A represents a porous particle or hollow particle, R represents a C1-C10 alkylene group or a thiuram group represented by the following formula (3)
(3)

(Wherein R < ₁ > is a C1-C20 alkyl group)
The method according to claim 1,
The porous particles or hollow particles are porous or hollow castle polyimide (PI), silica (SiO _2), titania (TiO ₂₎ and nano-particles selected from the group consisting of a combination thereof.
bookbinder; And
The porous particles or hollow particles dispersed in the binder and disposed adjacent to each other are bonded to each other through a disulfide group
.
5. The method of claim 4,
Wherein the nanoparticles are represented by Chemical Formula 1 or Chemical Formula 2 below.
Formula 1

(2)

(In the formulas (1) and (2), A represents a porous particle or hollow particle, L represents a C1-C10 alkylene group or a thiuram group represented by the following formula (3)
(3)

(Wherein R < ₁ > is a C1-C20 alkyl group)
5. The method of claim 4,
The porous particles or hollow particles are porous or hollow castle polyimide (PI), silica (SiO _2), titania (TiO ₂₎ and an insulating film selected from the group consisting of a combination thereof.
5. The method of claim 4,
Wherein the nanoparticles are contained in an amount of 1 to 50% by weight.
5. The method of claim 4,
Wherein the binder is selected from the group consisting of a polyimide (PI) resin, a polysiloxane resin, a poly (meth) acrylate resin, and a combination thereof.
Board;
A driving element positioned on the substrate;
A light emitting diode located on the substrate and connected to the driving element;
And a bank layer arranged to partially overlap an outer periphery of the first electrode constituting the light emitting diode to partition the pixel region,
Wherein the bank layer comprises the insulating film according to any one of claims 4 to 8.

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