KR101182434B1 - A method of preparing a composition for forming transparent desiccant layer for organic electroluminescence display - Google Patents

Abstract

The present invention is a method for producing a composition for forming a transparent hygroscopic film for an organic electroluminescent device, characterized in that after mixing a composition for forming a transparent hygroscopic film containing at least one selected from a metal oxide and a metal salt and a solvent, and milling it. The organic electroluminescent device provided with the transparent moisture absorption film manufactured by the manufacturing method is provided. The transparent moisture absorption film composition prepared according to the present invention is a metal oxide such as calcium oxide is uniformly dispersed in nano size and present in a high concentration, so using this composition, even if the thickness of the moisture absorption film becomes thick, the transparent moisture absorption film without light scattering is used. You can get it. Such a transparent moisture absorption film can be used for a top emission type organic electroluminescent element.

Description

A method of preparing a composition for forming transparent desiccant layer for organic electroluminescence display}

1A to 1D are diagrams schematically showing the structure of an organic EL device according to the present invention,

2 is a view showing the CaO particle size distribution in the transparent moisture absorption film forming composition obtained in Example 4 of the present invention,

3 is a view showing the CaO particle size distribution in the transparent moisture absorption film forming composition obtained in Example 9 of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

10 ... Substrate 11 ... Encapsulant

12 ... organic electroluminescent part 13 ... transparent moisture absorption film

14 ... sealant

The present invention relates to an organic electroluminescent device and a method of manufacturing the same, and more particularly, to a method for preparing a composition for forming a transparent hygroscopic film applicable to a top emission type and to an organic electroluminescent device employing a transparent hygroscopic film formed according to the method. It is about.

The organic electroluminescent device has a property that is degraded by the penetration of moisture. Therefore, the encapsulation structure is required to secure their stable operation and lifetime.

Conventionally, a metal can or glass is processed in a cap shape to have a groove, and a drying or drying agent for water absorption is mounted in a powder form or manufactured in a film form to adhere to the double-sided tape.

Japanese Patent Laid-Open No. 9-148066 discloses a laminate having a structure in which an organic light emitting material layer made of an organic compound is disposed between a pair of electrodes facing each other, and an airtight container and an airtight container which block the laminate from outside air. An organic electroluminescent display device having a drying means such as an alkali metal oxide or an alkali metal oxide is disclosed. However, due to the shape of the hermetic container, the organic electroluminescent device has a thick thickness of the entire display device. In addition, even if the drying means retains a solid state after adsorbing moisture, the drying means is not opaque and cannot be applied to front emission.

U. S. Patent No. 6,226, 890 discloses an organic electroluminescent device employing a hygroscopic layer formed using a hygroscopic agent and a binder comprising a solid having a particle size of 0.1 to 200 mu m.

However, this organic electroluminescent device is not only applicable to the front emission type due to its translucent or opaque transmission characteristics, but also has a lot of room for improvement due to insufficient water adsorption capacity .

The technical problem to be solved by the present invention is not only to improve the moisture adsorption ability to solve the above problems but also to prepare a composition for forming a transparent moisture-absorbing film that can be applied to the front emission type and the transparent prepared according to the manufacturing method An organic electroluminescent element having a hygroscopic film is provided.

In order to achieve the above technical problem, in the present invention, a transparent hygroscopic film for organic electroluminescent device is formed by mixing a composition for forming a transparent hygroscopic film comprising at least one selected from a metal oxide and a metal salt and a solvent, and then milling the composition. It provides a method for producing a composition for use.

Another technical problem of the present invention is achieved by an organic electroluminescent device having a transparent hygroscopic film obtained according to the above production method.

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

The present invention provides a method for producing a composition for forming a transparent moisture absorption film suitable for the top emission type of the organic electroluminescent device.

The transparent moisture absorbing membrane should have an excellent ability to adsorb moisture and oxygen to penetrate, and should have a transparent property with excellent transmittance, so that the composition for forming a transparent moisture absorbing membrane having such characteristics is provided to particles in which the emitted light Because scattering should not occur by the nano-sized metal oxide, for example, CaO should be dispersed stably. In addition, since it must be mixed with various additives such as an organic binder and an inorganic binder to have dispersion stability, solids must be present in a high concentration in the composition.

As such, the metal oxides or metal salts in the composition are prepared according to the following process to uniformly disperse the nano-size.

First, a metal oxide or metal salt and a solvent are added to prepare a composition for forming a transparent moisture absorption film.

Adding inorganic beads to the composition is preferred because it effectively reduces metal oxide size and has high stability against contamination. As a specific example of the inorganic beads, zirconia beads are used, and the particle diameter of the beads is not particularly limited, but is preferably 1 mm or less, particularly 0.1 to 0.5 mm. These beads are separated and removed after the end of the subsequent milling process.

In addition, a dispersant may be added to increase the dispersion efficiency of the metal oxide in the composition.

The composition is then milled. The method of milling here is not particularly limited, but milling is carried out using a device such as a paint shaker, dynomill, apex mill and the like. And milling time is variable, but is carried out for 1 to 60 hours, in particular for 4 to 30 hours.

After finishing the above-described milling process, a binder may be further added.

As the binder, an organic binder, an inorganic binder, an organic / inorganic composite binder or a mixture thereof is used. Herein, the organic binder is a low molecule or a polymer, and should be excellent in compatibility with metal oxide or metal salt particles and excellent in film formation. As an example of the organic binder which satisfy | fills such a characteristic, the at least 1 selected from acrylic resin, methacryl resin, polyisoprene, vinyl resin, epoxy resin, urethane resin, and cellulose resin is used. Examples of the acrylic resins include butyl acrylate, ethylhexyl acrylate, and the like. Examples of the methacryl resins include propylene glycol methacrylate and tetrahydrofurfree methacrylate. Examples thereof include vinyl acetate, N-vinylpyrrolidone, and the like, examples of epoxy resins include cycloaliphatic epoxides, examples of urethane resins include urethane acrylates, and examples of cellulose resins. Examples thereof include cellulose nitrate.

The inorganic binder is a metal or nonmetallic material such as silicon, aluminum, titanium, zirconium, etc., and has excellent miscibility with metal oxide or metal salt particles and excellent film forming property. As such an example, one or more selected from the group consisting of titania, silicon oxide, zirconia, alumina and their precircers are used.

The organic / inorganic composite binder is a material in which a metal, a non-metal material such as silicon, aluminum, titanium, zirconium, and the like are covalently linked to each other and have excellent miscibility with the above-described metal oxide or metal salt particles and excellent film forming properties. do. As the material satisfying these conditions, at least one selected from the group consisting of epoxy silane or derivatives thereof, vinyl silane or derivatives thereof, amine silane or derivatives thereof, methacrylate silane or a result of partial curing reaction thereof is used. In the case of using the above-mentioned partial curing reaction product, it may be used when controlling physical properties such as the viscosity of the composition.

Specific examples of the epoxy silane or derivatives thereof include 3-glycidoxypropyltrimethoxysilane or a polymer thereof.

Specific examples of the vinyl silane or derivatives thereof include vinyltriethoxysilnae or polymers thereof.

Moreover, 3-aminopropyltriethoxysilnae and its polymer can be mentioned as a specific example of the said aminesilane or its derivative (s).

Specific examples of the methacrylate silane or derivatives thereof include 3-tri (methoxysilyl) propyl acrylate} and polymers thereof.

As the binder used in the present invention, it is particularly preferable to select one which is excellent in thixotropy and leveling properties.

The content of the binder is preferably 10 to 5000 parts by weight based on 100 parts by weight or more selected from metal oxides and metal salts. If the content of the binder is less than 10 parts by weight, it is difficult to obtain a transparent moisture absorption film, and if it exceeds 5000 parts by weight, it is not preferable because it does not exhibit sufficient moisture absorption ability.

It is possible to obtain a transparent moisture absorbing film as a thick film by manufacturing a transparent moisture absorbing film using the above-mentioned binder, and to increase the amount of the nano-size moisture absorbing agent impregnated in the film to improve the moisture absorbing amount. And the kind of binder can be selected suitably, and the film | membrane which has a very transparent characteristic even in thickness of 100 micrometers or more can be obtained. And by using a binder, it becomes possible to adjust the viscosity of the composition for transparent moisture absorption film suitably, and to form a transparent moisture absorption film by a printing process.

The metal oxide used in the present invention reacts with water to break metal-oxygen-metal bonds to form metal hydroxides, thereby removing water.

At least one selected from the above metal oxides and metal salts uses alkali metal oxides, alkaline earth metal oxides, metal halides, metal sulfates and metal perchlorates, phosphorus pentoxide (P ₂ O ₅ ).

Examples of the alkali metal oxide include lithium oxide (Li ₂ O), sodium oxide (Na ₂ O) or potassium oxide (K ₂ O). Examples of the alkaline earth metal oxide include barium oxide (BaO) and calcium oxide. (CaO), or magnesium oxide (MgO), and examples of the metal sulfate are lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), Cobalt sulfate (CoSO ₄ ), gallium sulfate (Ga ₂ (SO ₄ ) ₃ ), titanium sulfate (Ti (SO ₄ ) ₂ ), or nickel sulfate (NiSO ₄ ). Examples of the metal halide include calcium chloride (CaCl ₂ ), magnesium chloride (MgCl ₂ ), strontium chloride (SrCl ₂ ), yttrium chloride (YCl ₂ ), copper chloride (CuCl ₂ ), cesium fluoride (CsF), Tantalum fluoride (TaF ₅ ), niobium fluoride (NbF ₅ ), lithium bromide (LiBr), calcium bromide (CaBr ₃ ), cerium bromide (CeBr ₄ ), selenium bromide (SeBr ₂ ), vanadium bromide (VBr ₂ ), magnesium bromide (MgBr ₂ ), barium iodide (BaI ₂ ) or magnesium iodide (MgI ₂ ), and examples of the metal perchlorate include barium perchlorate (Ba (ClO ₄ ) ₂ ) or magnesium perchlorate (Mg (ClO ₄ ) ₂ ). .

The dispersant may include at least one selected from acrylic resins, methacryl resins, urethane resins, polyisoprene, vinyl resins, epoxy resins, amide resins, sulfone resins, phthalate resins, phenoxide resins, and cellulose resins. At least one metal alkoxide-based compound selected from organic compounds, silicon alkoxides, titanium alkoxides, aluminum alkoxides, organic / inorganic composite silicon alkoxide polymers, organic / inorganic composite titanium polymers, organic / inorganic composite aluminum alkoxide polymers; And / or organic acids of acetylacetone, acetic acid and the like.

Specific examples of the acrylic resin include polyacrylate, polymethacrylate as an example of methacrylic resin, and cellulose acetate as an example of the cellulose resin. The weight average molecular weight of the organic compound is preferably 8000 to 15000.

Examples of the silicon alkoxide include ethyl silicate, examples of titanium alkoxide include titanium isopropoxide, examples of aluminum alkoxide include aluminum butoxide, examples of organic / inorganic composite silicon alkoxide polymers include epoxy propyl silicate. Examples of the organic / inorganic composite titanium polymer include titanium polymers such as titanium 2-ethylhexoxide, and examples of the organic / inorganic composite aluminum alkoxide polymers include aluminum acetylacetonate.                     

As the solvent, both a polar solvent and a nonpolar solvent can be used.

Alcohols, ketones, etc. are mentioned as an example of the said polar solvent, An aromatic hydrocarbon, an alicyclic hydrocarbon, an aliphatic hydrocarbon type organic solvent is mentioned as said nonpolar solvent. The solvent is preferably ethanol, dimethylformamide, ethanol, methanol, propanol, butanol, isopropanol. Methyl ethyl ketone, propylene glycol (mono) methyl ether (PGM), isopropyl cellulose (IPC), methyl cellosolve (MC), ethylene carbonate (EC), methyl cellosolve, ethyl cellosolve Use more than one.

The content of the dispersant in the composition for forming a transparent moisture absorption film is 1 to 100 parts by weight based on 100 parts by weight of the metal oxide. If the content of the dispersant is less than 1 part by weight, the additive effect is insignificant, and if the content of the dispersant is more than 100 parts by weight, the relative content of the metal oxide in the composition is reduced, which is not preferable.

The content of the solvent in the transparent moisture absorption film-forming composition is 400 to 1900 parts by weight based on 100 parts by weight of the metal oxide. If the content of the solvent is less than 400 parts by weight, the additive effect is insignificant, and if the content of the solvent exceeds 1900 parts by weight, the relative content of the metal oxide in the composition is reduced, which is not preferable.

The average particle diameter of the metal oxide particles in the composition obtained according to the above procedure is 20 to 300 nm and preferably 60 to 80 nm. The content of solids in the composition is preferably 5 to 30 parts by weight based on 100 parts by weight of the composition. If the average particle diameter exceeds 300 nm, the hygroscopic layer made using particles having such a large average particle diameter is undesired because scattering occurs in the visible light region, causing a haze of the film and a decrease in transmittance. When the content of the solid content is less than 5 parts by weight, the amount of the absorbent in the final transparent moisture absorbent solution decreases, and when it exceeds 30 parts by weight, the dispersion stability of the final transparent moisture absorbent is not preferable.

Looking at the manufacturing method of the organic EL device employing a transparent moisture absorption film using the composition for forming a transparent moisture absorption film obtained by the above-described process.

First, a substrate on which an organic EL is formed by sequentially stacking a first electrode, an organic film, and a second electrode is prepared. Subsequently, metal oxide or metal salt particles are mixed with a solvent and a dispersant to obtain a composition for forming a transparent moisture absorption film.

The composition is applied to the inner surface of the sealing substrate and dried and cured to obtain a transparent moisture absorption film.

In the coating step, it is carried out in accordance with dip coating, spin coating, spray coating, dispensing, or screen printing, in particular in terms of workability is preferred.

The curing step is made by heat curing or UV curing, the heat treatment temperature at the time of curing is preferably 100 to 250 ℃. If the heat treatment temperature exceeds 250 ℃, outgassing may occur as the binder is decomposed, and the cooling time after the heat treatment may increase, causing problems in the process time, if less than 100 ℃ solvent remaining in the moisture absorption membrane or binder Is uncured and undesirable.

The transparent moisture absorption film formed by the above-described manufacturing method of the present invention is a film having a thickness of 0.1 to 12 µm, has sufficient moisture absorption and oxygen adsorption characteristics, and is excellent in the function of sealing the organic EL device.

As described above, after preparing the encapsulating substrate on which the transparent moisture absorption film is formed, the sealant is applied to the encapsulating substrate and a portion of the organic electroluminescent portion on at least one side of the substrate by using a screen printing machine or a dispenser. Subsequently, the organic electroluminescent element of the present invention is completed by bonding the substrate and the sealing substrate together.

In some embodiments, the sealant may be further cured by using ultraviolet light, visible light, or heat after being bonded to the internal space of the organic electroluminescent device formed according to the above manufacturing process to vacuum or filling with an inert gas.

The transparent moisture absorption film formed by the said method has the characteristic to remain transparent before water absorption or after water absorption.

In the organic electroluminescent device of the present invention, the transparent hygroscopic film may be located in the inner space provided by the substrate and the sealing substrate. In particular, the transparent oxide film may be formed on an inner surface of the encapsulation substrate as shown in FIG. 1A, a sealant side surface as illustrated in FIG. 1B, or at least one side of the substrate and the encapsulation substrate (for example, a recess portion of the substrate as illustrated in FIG. 1C).

1A illustrates a schematic structure of an organic EL device according to an embodiment of the present invention.

Referring to this, the organic electroluminescent device is an organic electroluminescent device in which a substrate 10 made of glass or transparent insulator and one surface of the substrate 10 are formed, and a first electrode, an organic film, and a second electrode are sequentially stacked. Inner space in which the organic electroluminescent unit 12 is accommodated in combination with the substrate 10 to block the unit 12, the organic electroluminescent unit 12, and the organic electroluminescent unit 12 from the outside. The sealing substrate 11 is provided with a sealing substrate 11 coated with a transparent hygroscopic film 13 containing nano-sized pores on its inner surface. The encapsulation substrate 11 and the substrate 10 are joined by a sealant layer 14 coated on the outer side of the organic electroluminescent portion 12. The encapsulation substrate 11 has a function of sealing together with the encapsulation substrate with the organic electroluminescent portion therebetween.

Referring to FIG. 1B, in the organic electroluminescent device of the present invention, a transparent moisture absorption film 23 is formed on the side of the sealant layer 24.

Referring to FIG. 1C, in the organic electroluminescent device of the present invention, a recess 35 is formed on one surface of an encapsulation substrate 31 that is sealed with the substrate 30 to form an internal space, and the recess 35 is transparent. The moisture absorption film 33 is formed.

It is preferable to form especially a transparent nanoporous CaO thin film as said transparent moisture absorption film 13, 23, 33.

The organic electroluminescent units 12, 22, and 32 may be formed by evaporation, and may include a first electrode, an organic layer, and a second electrode, and the first electrode may be a cathode. The electrode can be the anode. In addition, the organic layer may include a hole injection layer, a hole transport layer, a light emitting layer, an electron injection layer, and / or an electron transport layer.

As the front substrates 11, 21, and 31, a glass substrate or a transparent plastic substrate that is an insulator is used, and when formed of a plastic substrate, a protective film for protecting the inner surface of the plastic substrate from moisture may be formed. The protective film has heat resistance, chemical resistance and moisture permeability. As such, when the encapsulation substrate is made of a transparent material, it may be used for the front light emitting type.

In order to apply to the bottom emission, the first electrode of the organic electroluminescent unit 12, 22, 32 is transparent and the second electrode may be formed as a reflective electrode, when applied to the top emission The first electrodes of the organic light emitting parts 12, 22, and 32 may be formed as reflective electrodes, and the second electrode may be formed as transparent electrodes. The first electrode is an electrode disposed close to the rear substrates 10, 20, and 30, and the second electrode is an electrode disposed close to the sealing substrates 11, 21, and 31.

In addition, in order to provide heat resistance, chemical resistance, and moisture permeability, an upper surface of the second electrode may further include a protective film made of an inorganic material that may flatten the top surfaces of the organic electroluminescent parts 12, 22, and 32. Can be formed. The protective film may be formed of a metal oxide or a metal nitride.

The inner space partitioned by the encapsulation substrates 11, 21, 31 and the substrates 10, 20, 30 of the present invention is kept in a vacuum or filled with an inert gas.

Although the thickness of the said transparent moisture absorption film 13, 23, 33 is more favorable under the conditions which ensure transparency, it is preferable that it is 0.1-12 micrometers normally. If the thickness of the transparent moisture absorption film 13 is less than 0.1 μm, it may not have sufficient moisture absorption characteristics. If the thickness of the transparent moisture absorption film 13 is greater than 12 μm, the transparent moisture absorption film 13 may be larger than the size of the beads included in the sealant, and the oxide film may not only come into contact with the cathode layer but also may penetrate moisture. It is not desirable that the area be turned on.

The organic electroluminescent device of the present invention is applicable to all of the top emission type, bottom emission type or both sides emission type.                     

The driving method of the organic EL device of the present invention is not particularly limited, and both the passive matrix (PM) driving method and the active matrix (AM) driving method are possible.

Hereinafter, the present invention will be described with reference to the following examples, but the present invention is not limited to the following examples.

Example 1

In a glove box, 57 g of ethanol and 3 g of anhydrous calcium oxide (CaO) powder were mixed in a 250 ml airtight container to prepare a composition for forming a transparent hygroscopic film. . After sealing this airtight container so that it may not be exposed to the external atmosphere, it was mounted in the paint shaker and milled for about 18 hours.

Thereafter, the beads and the calcium oxide dispersion were separated in the glove box, and the particle size in the dispersion was measured. And the content of solids in the calcium oxide dispersion thus obtained was about 15% by weight. 600 weight part of urethane acrylates which are 100 weight part of this dispersion liquids were mixed, and the composition for transparent moisture absorption film formation was prepared.

The transparent hygroscopic film-forming composition was printed on the etched glass and heat-treated at 100 ° C., followed by UV curing to form a transparent hygroscopic film.

Example 2

Except for using 57 g of ethanol, 3 g of anhydrous calcium oxide (CaO) powder, 3 g of anhydrous calcium oxide (CaO) powder, and 6 g of dimethylformamide, the same method as in Example 1 was used to prepare the transparent hygroscopic film forming composition. Was carried out accordingly.

Example 3

The same procedure as in Example 1 was conducted except that methylcellosolve was used instead of dimethylformamide.

Example 4

The same procedure as in Example 1 was conducted except that PGM was used instead of dimethylformamide.

Example 5

Except for using butanol instead of ethanol when preparing a composition for forming a transparent moisture-absorbing film was carried out in the same manner as in Example 1.

Example 6

48 g of ethanol was used instead of 57 g of ethanol, and 9 g of epoxycyclohexylsilane, which is an organic / inorganic composite silicon alkoxide, was added in the same manner as in Example 1, to prepare a transparent hygroscopic film-forming composition. It was.

Example 7-8

The organic / inorganic composite silicon alkoxide polymer was used in the same manner as in Example 6, except that titanium isopropoxide (organic / inorganic titanium alkoxide) and aluminum isopropoxide (organic / inorganic aluminum alkoxide) were used, respectively.                     

Example 9

In a glove box, 36 ml of a mixed organic solvent (1: 1 weight ratio) and 15 g of anhydrous calcium oxide (CaO) powder were mixed in a 250 ml sealed container, followed by an epoxy / heterocyclohexane, an organic / inorganic composite silicone. After adding 9 g of (Epoxycyclohexylsilane) to prepare a composition for forming a transparent hygroscopic film, zirconia beads having a diameter of 0.3 mm previously dried at 250 ° C. were added thereto and then sealed. After sealing this airtight container so that it may not be exposed to the external atmosphere, it was mounted in the paint shaker and milled for about 18 hours.

Thereafter, the beads and the calcium oxide dispersion were separated in the glove box, and the particle size in the dispersion was measured. And the content of solids in the calcium oxide dispersion thus obtained was about 15% by weight.

Example 10

The same procedure as in Example 9 was carried out except that acetylacetone was used instead of the organic / inorganic composite silicone alkoxide polymer.

Example 11

The same procedure as in Example 9 was conducted except that an acrylic resin (Mw = 8000-150000) (polyacrylate) was used instead of the organic / inorganic composite silicon alkoxide polymer.

Example 12

The same procedure as in Example 9 was carried out except that an epoxy resin (Mw = 8000-150000) was used instead of the organic / inorganic composite silicon alkoxide polymer.

The average particle diameter in the transparent hygroscopic film-forming composition obtained in Example 1-12 was investigated, and the results are shown in Table 1 below.

[Table 1]

division Average particle diameter (nm) Example 1 98.5 Example 2 87.2 Example 3 74.2 Example 4 74.2 Example 5 92.4 Example 6 64.1 Example 7 66.3 Example 8 66.3 Example 9 53.5 Example 10 69.5 Example 11 72.8 Example 12 79.7

CaO particle size distribution in the transparent hygroscopic film-forming compositions obtained in Examples 4 and 9 are shown in FIGS. 2 and 3, respectively.

2 and 3, it can be seen that the particle size is very small when using a dispersant.

Example 13

The transparent moisture absorption film-forming composition obtained in Example 1 was printed on a glass substrate and heat-treated at 150 ° C. to form a transparent moisture absorption film.

 A sealant epoxy resin was applied to at least one side of the soda glass substrate on which the transparent moisture absorption film was formed and at least one side of the glass substrate on which the first electrode, the organic film, and the second electrode were formed. Subsequently, the two substrates were bonded to each other to complete an organic EL device.

Comparative Example 1

An organic electroluminescent device was completed in the same manner as in Example 1, except that no transparent moisture absorption film was formed on the soda organic substrate.

Comparative Example 2

An ordinary getter (HD-204, Japan Dininic Co., Ltd.) is installed on top of a soda glass substrate, and the sealant epoxy is formed on at least one side of the soda glass substrate and at least one side of the glass substrate on which the first electrode, the organic film, and the second electrode are formed. Resin was applied. Subsequently, the two substrates were bonded to each other to complete an organic EL device.

The transmittance | permeability of the transparent moisture absorption film obtained by the said Example 1 was investigated.

As a result of the irradiation, the transmittance was also applicable to the front emission type as the film in a transparent state with 95% or more.

In the organic electroluminescent devices obtained according to Example 13 and Comparative Example 2, the moisture absorption rate of the transparent moisture absorption film was evaluated, and as a result, the moisture absorption ability and speed were improved in comparison with a conventional moisture absorbent getter (Comparative Example 2).

While the organic electroluminescent device manufactured according to Example 13 and Comparative Example 1-2 was stored at 70 ° C. and 90% relative humidity, the screen state over time was observed using a microscope.

As a result, it was found that the organic electroluminescent device manufactured according to Example 13 has an improved lifespan as compared with the case of Comparative Example 1-2.

The transparent moisture absorption film composition prepared according to the present invention is a metal oxide such as calcium oxide is uniformly dispersed in nano size and present in a high concentration, so using this composition, even if the thickness of the moisture absorption film is thick, the transparent moisture absorption film without light scattering is obtained. You can get it. Such a transparent moisture absorption film can be used for a top emission type organic electroluminescent element.

By using the transparent moisture absorption film of the present invention, it is possible to manufacture a top-emitting organic electroluminescent device having hygroscopic properties and transparent properties as compared with the case of using a conventional getter and ensuring a required lifetime characteristic. Thus, the transparent moisture absorption film of this invention is excellent in water and oxygen adsorption characteristic, and lifespan characteristic is improved. And as an encapsulating substrate, it is possible to use unetched planar glass instead of etched glass requiring processing. Thus, structural weaknesses (destructive properties) caused by using etched glass can be overcome.

Although described above with reference to the preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention described in the claims below. It will be appreciated.

Claims (15)

After mixing a composition for forming a transparent hygroscopic film comprising at least one selected from a metal oxide and a metal salt and a solvent, milling it, A method of manufacturing a composition for forming a transparent hygroscopic film for organic electroluminescent elements, wherein an inorganic bead is added to the composition before milling the composition for forming a transparent hygroscopic film, and the inorganic bead is removed after milling. delete The method for producing a transparent moisture absorption film-forming composition for organic electroluminescent devices according to claim 1, wherein a dispersant is further added to the transparent moisture absorption film-forming composition. The method of claim 3 wherein the dispersant One or more organic compounds selected from acrylic resins, methacryl resins, polyisoprene, vinyl resins, epoxy resins, amide resins, sulfone resins, phthalate resins, phenoxide resins and cellulose resins; At least one metal alkoxide-based compound selected from silicon alkoxide, titanium alkoxide, aluminum alkoxide, organic / inorganic composite silicon alkoxide polymer, organic / inorganic composite titanium polymer, organic / inorganic composite aluminum alkoxide polymer; And / or acetylacetone. A method for producing a composition for forming a transparent hygroscopic film for organic electroluminescent devices. The method of manufacturing a composition for forming a transparent hygroscopic film for organic electroluminescent elements according to claim 1, wherein after the milling of the composition for forming a transparent hygroscopic film, a binder is further added. The method of claim 5, wherein the binder is at least one selected from an organic binder, an inorganic binder and an organic / inorganic composite binder, and the content thereof is 10 to 5000 parts by weight based on 100 parts by weight or more selected from metal oxides and metal salts. The manufacturing method of the composition for transparent moisture absorption film formation for organic electroluminescent elements characterized by the above-mentioned. The organic electroluminescent device according to claim 6, wherein the organic binder is at least one selected from acrylic resin, methacryl resin, polyisoprene, vinyl resin, epoxy resin, urethane resin, and cellulose resin. Method for producing a composition for forming a transparent moisture absorption film for use. The method of claim 6, wherein the inorganic binder is at least one selected from the group consisting of titania, silicon oxide, zirconia, alumina, and precursors thereof. 7. The organic / inorganic composite binder according to claim 6, wherein the organic / inorganic composite binder is selected from the group consisting of epoxy silane or derivatives thereof, vinyl silane or derivatives thereof, amine silane or derivatives thereof, methacrylate silane or derivatives thereof, or a result of a partial curing reaction thereof. Method for producing a composition for forming a transparent hygroscopic film for an organic electroluminescent device, characterized in that at least one selected. According to claim 1, At least one selected from the metal oxides and metal salts, A composition for forming a transparent hygroscopic film for an organic electroluminescent device, characterized in that at least one selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, metal halides, metal sulfates and metal perchlorates, and phosphorus pentoxide (P ₂ O ₅ ). Manufacturing method. The method of claim 10, wherein the alkali metal oxide is lithium oxide (Li ₂ O), sodium oxide (Na ₂ O) or potassium oxide (K ₂ O), The alkaline earth metal oxide is barium oxide (BaO), calcium oxide (CaO), or magnesium oxide (MgO), The metal sulfate is lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), cobalt sulfate (CoSO ₄ ), gallium sulfate (Ga ₂ (SO ₄₎ ) ₃ ), titanium sulfate (Ti (SO ₄ ) ₂ ), or nickel sulfate (NiSO ₄ ), The metal halide is calcium chloride (CaCl ₂ ), magnesium chloride (MgCl ₂ ), strontium chloride (SrCl ₂ ), yttrium chloride (YCl ₂ ), copper chloride (CuCl ₂ ), cesium fluoride (CsF), tantalum fluoride ( TaF ₅ ), niobium fluoride (NbF ₅ ), lithium bromide (LiBr), calcium bromide (CaBr ₃ ), cerium bromide (CeBr ₄ ), selenium bromide (SeBr ₂ ), vanadium bromide (VBr ₂ ), magnesium bromide (MgBr ₂₎ ), Barium iodide (BaI ₂ ) or magnesium iodide (MgI ₂ ), The metal perchlorate is barium perchlorate (Ba (ClO ₄ ) ₂ ) or magnesium perchlorate (Mg (ClO ₄ ) ₂ ) The method of manufacturing a composition for forming a transparent hygroscopic film for an organic electroluminescent device, characterized in that. The method of claim 1, wherein a paint shaker, dyno mill, or apex mill is used for the milling. . The method of claim 1, wherein the solvent is ethanol, dimethylformamide, ethanol, methanol, propanol, butanol, isopropanol. Methyl ethyl ketone, pure water, propylene glycol (mono) methyl ether (PGM), isopropyl cellulose (IPC), methylene chloride (MC), ethylene carbonate (EC), methyl cellosolve and ethyl cellosolve A method for producing a composition for forming a transparent hygroscopic film for organic electroluminescent devices, characterized in that at least one. According to claim 1, wherein the solids content in the composition is 5 to 30 parts by weight based on 100 parts by weight of the total composition, The average particle diameter of the particle | grains in a composition is 20-300 nm, The manufacturing method of the composition for transparent hygroscopic film formation for organic electroluminescent elements characterized by the above-mentioned. delete

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