JP2003059643A - Electroluminescence element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an EL element that can demonstrate its original gas barrier performance without corrosion or the gas barrier layer, even when patterning the electrode layer by etching or the like is made on the base material formed with the gas barrier layer when manufacturing the EL element. SOLUTION: The EL element comprises a base material made of resin, a gas barrier layer formed on the resin base material, a ceramics film derived from polysilazane formed on the gas barrier layer, a first electrode layer formed on the ceramics film in a pattern form, an organic EL layer having at least a luminous layer formed on the first electrode layer, and a second electrode layer formed on the above organic EL layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent (hereinafter sometimes abbreviated as EL) element which is preferably used as a display or a light emitting element of various information industrial equipment, and particularly stable over a long period of time. The present invention relates to an organic EL device that maintains the above-mentioned emission characteristics.

[0002]

2. Description of the Related Art In recent years, as a display replacing a CRT (Cathode-Ray-Tube) display which has a large occupied area and a large weight, a flat panel display (F
PD) has been put to practical use. And for FPD,
For example, a liquid crystal display (LCD) has been widely spread as a display for various portable electronic devices, notebook computers and small televisions, and FPDs other than LCDs such as a plasma display panel (PDP) have been put into practical use.

As one of such FPDs, there is an EL (hereinafter sometimes abbreviated as EL) display, and the EL display has been developed for a relatively long time. There is a problem in terms of lifespan and so on, and it is not widely used yet.

Further, an inorganic compound thin film has been conventionally used as a light emitting layer of an EL element to be an EL display, but an EL element using an inorganic compound thin film has a low driving efficiency as well as a high driving voltage. Only the brightness could be displayed. On the other hand, in recent years, as a light emitting layer of an EL element, a layer using an organic compound thin film having a low driving voltage and a high light emitting efficiency has been used. Further, an organic EL element (organic electroluminescence element) using an organic compound thin film
Has a problem in terms of life, but the development of a material for an organic light-emitting layer capable of extending the life has progressed, and it has become possible to put it into practical use at a level comparable to LCDs.

It is known that when such an organic EL element is driven continuously or discontinuously for a certain period of time, the light emission characteristics such as light emission luminance, light emission efficiency and light emission uniformity are significantly reduced as compared with the initial case. There is. The causes of such deterioration of the light emission characteristics are oxidation of the electrode by oxygen that has entered the organic EL element, oxidative decomposition of the organic material due to heat generation during driving, and moisture in the air that has entered the organic EL element. Examples include oxidation of electrodes and modification of organic substances.

In order to prevent such oxygen and moisture from entering the EL element, a gas barrier layer has been formed on a resin base material. In this method, a thin film having a gas barrier property is vapor-deposited on the surface of a resin base material to block intrusion of moisture and oxygen from the outside.

On the other hand, in a full-color EL device or the like,
A matrix structure in which a plurality of anode electrode lines and a plurality of cathode electrode lines are crossed is generally used for an EL element. In this case, it is necessary to pattern the transparent electrode layer on the base material in a stripe shape, and at this time, patterning may be performed by wet etching. In such a case, such patterning is performed on the resin base material on which the gas barrier layer is formed, and at this time, the gas barrier layer is corroded, so that the required gas barrier property is obtained. There was a problem that I could not do it.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in manufacturing an EL element, patterning such as etching of an electrode layer is performed on a substrate having a gas barrier layer formed thereon. The main object of the present invention is to provide an EL element that can exhibit its original gas barrier properties without being corroded by the gas barrier layer.

[0009]

In order to achieve the above object, the present invention provides a resin base material, a gas barrier layer formed on the resin base material, as described in claim 1. An organic EL layer having a polysilazane-derived ceramic coating formed on the gas barrier layer, a first electrode layer formed in a pattern on the ceramic coating, and at least a light emitting layer formed on the first electrode layer. Another object of the present invention is to solve the above-mentioned problems by providing an EL element having a second electrode layer formed on the organic EL layer.

As described above, by providing the ceramic coating derived from polysilazane on the gas barrier layer, the gas barrier layer formed on the substrate can be formed even when the first electrode layer such as the ITO film is patterned by the wet method. The original gas barrier property can be maintained without being corroded, and the deterioration of the organic EL layer can be prevented.

In the invention described in claim 1, as described in claim 2, it is further sealed with a sealing base material, and the inner surface of the sealing base material is ceramics derived from polysilazane. It is preferable that a film is formed. Since the ceramic coating has good adhesiveness, the ceramic coating can be arranged on both surfaces of the resin base material and the sealing base material by arranging the ceramic coating on the inner surface of the sealing base material. This is because the adhesiveness at the time of sealing can be improved.

In the present invention, as described in claim 3, a polysilazane-containing coating liquid is applied to a resin base material on which a gas barrier layer is formed, and the temperature is within a range of 50 ° C to 200 ° C. E characterized by having a step of firing
A method for manufacturing an L element is provided.

Since the base material used in the present invention is a resin-made base material, there is a possibility that physical properties may be deteriorated when it is baked at a high temperature. This is because the firing can be performed at a temperature equal to or lower than the above temperature to prevent deterioration of the base material.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An EL device of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the EL element of the present invention. In this example, a silicon oxide vapor deposition film 2 and a polysilazane-derived ceramic coating 3 laminated on the silicon oxide vapor deposition film 2 are formed on a transparent resin base material 1.

A transparent first electrode layer 4 is formed in a stripe pattern on the ceramic coating 3. Then, the organic EL layer 5 is laminated on the first electrode layer 4, and the second electrode layer 6 made of silver or the like is vapor-deposited thereon. And finally, the whole is sealed by the sealing base material 7, and the EL element is formed.

As shown in this example, the present invention has a great feature in that the ceramic coating 3 derived from polysilazane is formed on the silicon oxide vapor deposition film 2 which is the gas barrier layer.

Since the ceramic coating 3 derived from polysilazane is formed in this manner, even when the first electrode layer 4 is patterned by a wet method,
Since the ceramic coating 3 derived from polysilazane has excellent etching resistance, it is not corroded.
Therefore, the silicon oxide vapor deposition film 2 formed thereunder
Does not corrode or deteriorate, and the gas barrier property of the EL element does not deteriorate.

In general, it cannot be said that the resin base material 1 is necessarily always smooth, and therefore, when the first electrode layer 4 is formed on the resin base material 1, the adhesion to the first electrode layer 4 is poor and the result is low. As a result, there is a problem that the first electrode layer 4 peels off. In this case, by forming the ceramic coating 3 derived from polysilazane as described above, the adhesiveness with the first electrode layer 4 can be improved, and the problem such as peeling of the first electrode layer can be eliminated. it can.

Next, such an EL element of the present invention will be described separately for each constitution.

1. Polysilazane-Derived Ceramic Coating A feature of the present invention resides in that the polysilazane-derived ceramic coating is formed on the gas barrier layer as described above. Here, the ceramic coating derived from polysilazane is a ceramic obtained by applying a polysilazane coating solution containing at least polysilazane and a solvent onto the gas barrier layer and heating it as necessary.

(Polysilazane) The polysilazane used in the present invention has the general formula (I)

[0022]

[Chemical 1]

(However, R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a group other than these groups in which the group directly bonded to silicon is carbon. , An alkylsilyl group, an alkylamino group, an alkoxy group or a metal atom, provided that at least one of R ¹ , R ² and R ³ is a hydrogen atom).

The polysilazane to be used may be any polysilazane having at least a Si--H bond or an N--H bond in the molecule. Not only polysilazane alone, but also a copolymer of polysilazane and another polymer or polysilazane and other It can also be used as a mixture with the compound of.

The polysilazanes to be used include those having a chain structure, a cyclic structure, or a crosslinked structure, or those having a plurality of these structures simultaneously in the molecule, and these can be used alone or in a mixture.

As a typical example of such a polysilazane, for example, perhydropolysilazane having hydrogen atoms in R ¹ , R ² and R ³ in the above general formula (1) can be mentioned. The method for producing this perhydropolysilazane is described in, for example, Japanese Patent Publication No. 63-16325, D. Seefert
h et al. Communication of Am. Cer.
Soc. , C-13, January 1983. Has been reported to.

The method for producing polysilazane having hydrogen atoms in R ¹ and R ² and a methyl group in R ³ in the above general formula (I) is described in D. Seeferth et al., Polym. Prep
r. , Am. Chem. Soc. , Div. Poly
m. Chem. , 25, 10 (1984). The polysilazane obtained by this method is a chain polymer having a repeating unit of — (SiH ₂ NCH ₃ ) — and a cyclic polymer, and neither has a crosslinked structure.

Further, in the above general formula (I), R ¹ and R ^{3 are}
A method for producing a polyorgano (hydro) silazane having a hydrogen atom in R and an organic group in R ² is described in D. Seeferth et al Po
lym. Prepr. , Am. Chem. Soc. , D
iv. Polym. Chem. , 25, 10 (198
4), JP-A-61-89230, JP-A-62-1.
It is reported in Japanese Patent No. 56135.

The polysilazanes obtained by these methods have, as repeating units of — (R ² SiHNH) —, those having a cyclic structure with a degree of polymerization of 3 to 5 or (R ³ SiHNH) _x [(R ² Si
H) _1.5 N] _1-X (0.4 <x <1) has a compound having a chain structure and a cyclic structure at the same time in the molecule.

Furthermore, in the above general formula (I), polysilazane having a hydrogen atom in R ¹ and an organic group in R ² and R ³ ,
Further, those having an organic group for R ¹ and R ² and a hydrogen atom for R ³ have a cyclic structure mainly having — (R ¹ R ² SiNR ³ ) — as a repeating unit and having a degree of polymerization of 3 to 5. There is.

The polysilazane used in the present invention has a main skeleton composed of the unit represented by the general formula (I), and the unit represented by the general formula (I) is cyclized as is apparent from the above. In that case, the cyclic portion serves as a terminal group, and when such cyclization is not carried out, the terminal of the main skeleton may be a group similar to R ¹ , R ² , and R ³ or hydrogen. it can.

In addition, low temperature ceramized polysilazane can also be used in the present invention.

(Polysilazane Coating Liquid) The ceramic thin film derived from polysilazane used in the present invention is made into ceramic by applying the polysilazane coating liquid containing the polysilazane as described above and then heating it as needed. is there.

If the molecular weight of the polysilazane used in such a polysilazane coating solution is too low, the yield upon firing will be low, which is not practical. On the other hand, if the molecular weight is too high, the stability of the solution is low and a sound film cannot be obtained. For these reasons, the molecular weight of the polysilazane used is a number average molecular weight with a lower limit of 100, preferably 500. The upper limit is 50,000, preferably 10,000.

Solvents used for the polysilazane coating solution include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbon hydrocarbon solvents, halogenated methane, halogenated ethane, halogenated hydrocarbons such as halogenated benzene. Ethers such as aliphatic ethers and alicyclic ethers can be used.

Preferred solvents include halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, bromoform, ethylene chloride, ethylidene chloride, trichloroethane and tetrachloroethane, ethyl ether, isopropyl ether, ethyl butyl ether, butyl ether, 1,2. Ethers such as dioxyethane, dioxane, dimethyldioxane, tetrahydrofuran, tetrahydropyran, pentanehexane, isohexane, methylpentane, heptane, isoheptane, octane, isooctane, cyclopentane, methylcyclopentane,
Hydrocarbons such as cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene and the like can be mentioned.

When using these solvents, two or more kinds of solvents may be mixed in order to adjust the solubility of polysilazane and the evaporation rate of the solvent.

The amount (ratio) of the solvent used is selected so as to improve the workability depending on the coating method adopted, and it varies depending on the average molecular weight, the molecular weight distribution and the structure of the polysilazane used, so that they can be freely mixed as appropriate. . The solid content concentration is preferably in the range of 1 to 50% by weight.

Further, in the above polysilazane coating solution, at least one of an appropriate filler and extender can be added, if necessary. The addition amount of the filler is in the range of 0.05 to 10 parts by weight, and the particularly preferable addition amount is in the range of 0.2 to 3 parts by weight, relative to 1 part by weight of polysilazane.

Furthermore, in the above polysilazane coating liquid, various pigments, leveling agents, antifoaming agents, antistatic agents, ultraviolet absorbers, pH adjusters, dispersants, surface modifiers, plasticizers, You may add a drying accelerator, a flow stop agent, etc.

The coating method of the polysilazane coating solution in the present invention is not particularly limited, and is a commonly used coating method such as spin coating method, dip coating method, roll coating method, bar coating method, spray coating method. The method is used.

(Ceramics Coating) The ceramic coating formed by using the above polysilazane coating solution generally depends on the type of starting polysilazane, the firing conditions, etc., but generally, silicon nitride, silicon oxynitride, silicon oxide. And may contain silicon carbide in some cases.

The thickness of such a ceramic coating is
Within the range of 1.0 nm to 10000 nm, especially 50 nm to
It is preferably within the range of 5000 nm. If the thickness is less than the above range, the wet etching resistance is lowered, and the gas barrier film may be deteriorated when wet etching is performed, which is not preferable. Further, even if the film thickness is made thicker than the above range, the etching resistance does not further improve, which is disadvantageous in terms of cost.

2. Gas Barrier Layer In the EL element of the present invention, the gas barrier layer is formed on the resin base material, and the ceramic coating as described above is formed thereon.

The gas barrier layer used in the present invention is not particularly limited as long as it has a gas barrier property, and may be opaque depending on the direction of light emission from the organic EL layer.

The gas barrier layer used in the present invention has a water vapor permeability of 2.0 g at room temperature of 40 ° C. and relative humidity of 100%.
/ M ² · day · atm or less, room temperature 25 ° C, relative humidity 9
Oxygen permeability at 0% is 2.0 cc / m ² · day · at
It is preferably a transparent barrier layer having a thickness of m or less, and specific examples thereof include the following barrier layers.

Laminated Barrier Layer of Inorganic (Oxide) Thin Film and Coating Layer Containing Inorganic Oxide Thin film layer made of inorganic material or inorganic oxide formed by vapor phase epitaxy, and the following general formula (1) A laminated thin film of a coating layer formed by applying a coating material containing at least a polycondensate obtained by hydrolysis of the represented silicon compound can be used as a barrier layer.

R′SiR ₃ (1) (In the general formula (1), R ′ is stable to hydrolysis and is polymerizable by irradiation with heat and / or ionizing radiation, and R is an OH group and / or Alternatively, a group susceptible to hydrolysis) The film layer made of the above-mentioned inorganic material or inorganic oxide can be formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method.

The monomer gas used when forming a film by the CVD method is 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, methyltrimethoxysilane, hexamethyldisilane, methylsilane. , Dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane,
Phenyltriethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane and the like can be mentioned, particularly 1,1,3,3-tetramethyldisiloxane,
Hexamethyldisiloxane is preferably used.

The thin film formed by the CVD method is a continuous thin film mainly composed of silicon oxide SiOx, and a thin film of SiOx (X = 1.3 to 2.0) is preferable from the viewpoint of transparency. The thickness of this thin film is 400 Å or less, preferably about 100 to 250 Å.

On the other hand, in the case of forming a thin film by the PVD method, it is preferable to use a metal oxide such as silicon oxide, aluminum oxide, magnesium oxide, titanium oxide, zinc oxide, tin oxide, zirconium oxide, iron oxide as a vapor deposition material. As a vapor deposition method, vacuum vapor deposition, ion plating, sputtering, ion cluster beam and the like can be used. Further, as a heating method for the vapor deposition material, resistance heating,
Examples include high frequency induction heating and electron beam (EB) heating. Further, in addition to directly heating the above vapor deposition material to form a vapor deposition film, a thin film is formed by a reactive vapor deposition method in which the vaporized material vaporized by heating is reacted with oxygen gas in a gas phase or a plasma gas phase. May be.

The thickness of the thin film formed by the PVD method is 1
It is about 00 to 1000Å, preferably about 200 to 500Å.

Regarding the coating layer, examples of the group R'in the above general formula (1) include the following epoxy atomic groups and groups containing a carbon double bond. Epoxy atomic group: glycidyloxyalkyl group,
In particular, it is a group having 1 to 4 carbon atom groups in the alkyl part, and a particularly preferable example is γ-glycidyloxypropyl. Group containing carbon double bond: an optionally substituted alkenyl group and alkynyl group, for example, 2 to 20
A straight chain or cyclic group having 1, preferably 2 to 10 carbon atoms and at least one carbon double bond, especially lower such as vinyl, 1- and 2-propenyl, butenyl, isobutenyl, styryl and propargyl. An atomic group containing an alkenyl group and an alkynyl group, or a methacryl or acryl group is particularly preferable.

The group R in the general formula (1) is, for example, hydrogen, halogen, alkoxy, hydroxyl or alkylcarbonyl, and more specifically, methoxy, ethoxy, n-propoxy, i-propoxy, n-. Butoxy, sec-butoxy, tert-butoxy, isobutoxy, β-methoxyethoxy, acetyloxy, propionyloxy, monomethylamino, monoethylamino,
Examples thereof include dimethylamino, diethylamino, N-ethylanilino, methylcarbonyl, ethylcarbonyl, methoxycarbonyl and ethoxycarbonyl. The group R of the general formula (1) does not exist in the final product and is lost by hydrolysis, and the hydrolysis product must be removed immediately or later by a suitable method.
Groups which have no substituents and which give low molecular weight hydrolysis products such as lower alcohols such as methanol, ethanol, propanol and butanol are preferred.

The compound of the general formula (1) is wholly or partly in the form of precondensation, that is, the compound produced by the partial hydrolysis of the compound of the general formula (1) alone or as shown below. It can be used by mixing with other hydrolyzable compounds. Such oligomers are preferably soluble in the reaction medium and have a degree of linear or cyclic condensation of about 2 to.
A low molecular weight partial condensate (polyorganosiloxane) of 100, particularly 2 to 6, is preferable.

Examples of the compound of the general formula (1) include γ-
(Meth) acryloxypropyltrimethoxysilane,
Vinyltrichlorosilane, vinyltrimethoxysilane,
Examples thereof include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane and γ-glycidyloxypropyltrimethoxysilane.

The compound of the general formula (1) is mixed with a compound represented by the following general formula (2), and these compounds are hydrolyzed, preferably completely hydrolyzed, to give water of the corresponding oxide. It can be converted to Japanese.

MRn (2) (In the general formula (2), M is a metal element selected from silicon, aluminum, titanium, zirconium, vanadium, boron and tin, and R is an OH group and / or a group susceptible to hydrolysis. , N is the valence of the metal element) The group R in the general formula (2) may be the same as or different from the group R in the general formula (1). In addition, the general formula (2)
The compound represented by can be mixed with the silicon compound of the general formula (1) in a molar ratio of 1:99 to 99: 1.

In addition to the compounds represented by the general formulas (1) and (2), the coating layer constituting the barrier layer may contain a resin having a hydrogen bond-forming group as a binder component. Examples of the resin having a hydrogen bond-forming group include:
Polymer having hydroxyl group and its derivative (polyvinyl alcohol, polyvinyl acetal, ethylene-vinyl alcohol copolymer, phenol resin, methylolmelamine, etc. and its derivative); Polymer having carboxyl group and its derivative (poly (meth) acrylic acid, A homo- or copolymer containing a unit of a polymerizable unsaturated acid such as maleic anhydride or itaconic acid, and an esterified product of these polymers (a vinyl ester such as vinyl acetate, a (meth) acrylic ester such as methyl methacrylate) (A homopolymer or a copolymer containing units of), a polymer having an ether bond (polyalkylene oxide, polyoxyalkylene glycol, polyvinyl ether, a silicon resin, etc.); a polymer having an amide bond (> N (COR) -bond ( In the formula,
R is a hydrogen atom, an alkyl group which may have a substituent,
N-acylated polyoxazoline or polyalkyleneimine having an aryl group which may have a substituent); polyvinylpyrrolidone having an NC (O) -bond and a derivative thereof; polyurethane having a urethane bond; Examples thereof include a polymer having a urea bond.

The resin having a hydrogen bond-forming group as described above is 1 to 1000 parts by weight, preferably 5 to 30 parts by weight, relative to 100 parts by weight of the compounds represented by the general formulas (1) and (2).
It can be used in the range of parts by weight.

The coating liquid for forming the coating layer can be prepared by a conventionally known method. For example, the starting material is dissolved in a suitable solvent such as ethanol or propanol, and it is contacted with the stoichiometrically required amount of water, preferably one or a few parts excess of water. The solvent to be used includes, in addition to the above lower aliphatic alcohol, lower dialkyl ketones and esters such as acetone and methyl isobutyl ketone, preferably lower dialkyl ethers such as diethyl ether and T.
HF, amides, esters, especially ethyl acetate, dimethylformamide, and mixtures thereof.

The hydrolysis is generally carried out at a temperature of -20 to 130 ° C, preferably 0 to 30 ° C, or at the boiling point of the solvent used. The method of contacting can be appropriately set depending on the reactivity of the raw material used, for example, a method of slowly dropping the dissolved raw material into water, water is added to the dissolved raw material at once, or divided into several times. There are ways. In addition, instead of adding water as it is, water is introduced into the reaction mixture by using an inorganic substance containing water (such as an adsorbent containing water such as molecular sieves) or an organic substance (such as 80% ethanol). You can do it.

Further, water can be added by a reaction for forming water, for example, a reaction for forming an ester from an acid and an alcohol.

The polycondensation can be carried out by adding a catalyst such as a compound releasing a proton or a hydroxyl ion, or amines. The catalyst concentration is preferably 3 mol or less per liter. The total amount of the raw material compounds need not be present at the time of disclosure of hydrolysis (polycondensation), and only a part of the raw material compounds may be first contacted with water, and then the remaining raw material compounds may be added.

The time required for the reaction can be appropriately set according to the raw material compound, the catalyst used, the reaction temperature and the like.
The pressure during the reaction is usually atmospheric pressure, but it may be under pressure or under reduced pressure.

A commercially available photopolymerization initiator may be added to the coating solution to form a coating solution curable by ionizing radiation. Further, by adding a thermal reaction initiator (for example, dibenzoyl peroxide, tert-butyl perbenzoate, azobisisobutyronitrile, etc.) to the coating liquid, a thermosetting coating liquid can be obtained. Further, an initiator which initiates an ionic polymerization reaction can be added to the coating liquid.

When such a reaction initiator is added, the addition amount is preferably about 0.5 to 2% by weight.

The coating layer constituting the barrier layer is formed by dipping the coating solution prepared as described above, dip coating, flow coating, curtain coating, spin coating, spray coating,
It can be performed by coating with a bar coat or the like, drying, and curing. The thickness of this coating layer is 0.01 to 1.0
It is preferably about μm.

Barrier layer composed of thin film formed by CVD method This is a thin film formed by plasma CVD method using a gas containing at least an organosilicon compound vapor and oxygen, and silicon oxide SiOx (x = 1 to 2) And at least one compound containing at least one element selected from the group consisting of carbon, hydrogen, silicon and oxygen.

The organic silicon compound as a raw material is 1,1,3,3
-Tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, methyltrimethoxysilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane. , Tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane and the like, particularly 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane It is preferably used.

The thickness of the silicon oxide SiOx is 10 to 30.
00Å, preferably 60 to 400Å, and in view of transparency, silicon oxide SiOx (x = 1.3 to 2) is preferable.

In addition, silicon oxide SiOx is contained in the barrier layer.
Examples of the compound existing together include a C—H bond.
A compound having, a compound having a Si-H bond, or
Carbon simple substance is graphite, diamond, fullere
If it is in the shape of a ring,
It may include derivatives thereof. Specifically, CH ₃
Hydrocarbon with parts, SiH₃Cyril, SiH₂
Hydrosilica such as silylene, SiH₂OH silanol
And the like, such as a hydroxyl group derivative. Other than the above
Even by changing the conditions of the deposition process, the barrier layer
It is possible to change the type and amount of the compound contained in
Wear. The content of these compounds in the barrier layer is
0.1 to 50% by weight, preferably 5 to 20% by weight
is there.

A laminated barrier layer of a silicon oxide thin film and an inorganic / organic hybrid film is used as a vapor deposition source of silicon oxide SiOx (x = 1 to 2), and oxygen gas is simultaneously supplied with the vaporized gas of silicon oxide, if necessary. PVD such as vacuum deposition method, sputtering method, ion plating method and cluster ion beam method
Method, plasma CVD method, thermal CVD method, optical CV
Using the D method or the like, a silicon oxide thin film having a thickness of about 50 to 3000 Å is formed. On this silicon oxide thin film, an inorganic / organic hybrid film is formed by sol-gel film forming a barrier layer. The inorganic / organic hybrid film is a thin film using an organic / inorganic composite obtained by partially organically modifying a metal oxide polymer having a silicon-oxygen-silicon bond obtained by a hydrolysis reaction of an organic silicon compound.

The above-mentioned inorganic / organic hybrid film can be formed as follows. First, the general formula M (O
R) n (where M is Si, Al, Sr, Ba,
Pb, Ti, Zr, La, Na or other metal element, R is an alkyl group having 1 to 8 carbon atoms such as methyl, ethyl, propyl, butyl, etc.) and one or more metal alkoxides Is used to cause a hydrolysis reaction and a polycondensation reaction in the coexistence of water and alcohol, or in the course of this reaction, or after the completion of the reaction, an organic substance or a catalyst is added to increase the molecular weight to give a sol Prepare the coating solution. This coating liquid is gravure coat, roll coat,
When a silicon oxide thin film is coated by a method such as reverse coating or knife coating and heated in a temperature range of about 70 to 200 ° C., an amorphous ceramic transparent inorganic / organic hybrid film is obtained. The thickness of the inorganic / organic hybrid film is about 1000Å to 50 μm.

In the above sol-gel film formation, the organic substance added to the reaction system is, for example, a low molecular weight substance or a high molecular weight substance having a highly reactive functional group such as alcohol, aldehyde, carboxylic acid, amide, amine or isocyanate. Can be used. Moreover, as the catalyst, an organic acid, an organic base, an inorganic acid, an inorganic base, a metal oxide, or the like can be used. The inorganic / organic hybrid film formed by the above sol-gel film exhibits a very good barrier property together with the silicon oxide thin film.

3. Resin Base Material As the resin base material used in the present invention,
It is not particularly limited as long as it has a predetermined strength enough to support the EL element, but as described above, since light is normally emitted to the resin base material side, a transparent resin is used in this case. Is preferably formed.

As such a resin, a fluororesin,
Polyethylene, polypropylene, polyvinyl chloride, polyvinyl fluoride, polystyrene, ABS resin, polyamide, polyacetal, polyester, polycarbonate, modified polyphenylene ether, polysulfone, polyarylate, polyetherimide, polyethersulfone, polyamideimide, polyimide, polyphenylene sulfide , Liquid crystalline polyester, polyethylene terephthalate, polybutylene terephthalate, polymicroxylene dimethylene terephthalate, polyoxymethylene, polyether sulfone, polyether ether ketone, polyacrylate, acrylonitrile-styrene resin, ABS resin, phenol resin, urea resin, Melamine resin, unsaturated polyester resin, epoxy resin, polyurethane, silicone resin , And the like, and amorphous polyolefin.

In the present invention, such a substrate may be plate-shaped or film-shaped depending on the application.

4. First Electrode Layer The first electrode layer used in the present invention is not particularly limited as long as it is a material that can be patterned into a predetermined shape.

However, as described above, since the light is generally emitted on the surface side of the base material, the first electrode layer formed on the base material is preferably a transparent electrode. Specific examples thereof include a tin oxide film, an ITO film, a complex oxide film of indium oxide and zinc oxide, and the ITO film is preferably used in the present invention.

Such a first electrode layer is generally formed in a line shape (striped shape) on the base material, and is usually formed by line patterning by a photolithography method or the like. The present invention is characterized by the protection of the gas barrier layer in the wet etching step at the time of patterning, and since the ceramic coating as described above is formed, the gas barrier layer is corroded in the etching step. Therefore, the gas barrier property of the gas barrier layer can be maintained, and the life of the EL element can be extended.

5. Organic EL Layer In the present invention, as shown in FIG. 1, the organic EL layer 5 is arranged on the patterned first electrode layer 4.

Since the present invention is an EL device having such an organic EL layer, it is particularly necessary to prevent the intrusion of oxygen and water. At this time, when a resin base material is used, the gas barrier property is poor, and therefore it is necessary to form a gas barrier layer, and it is necessary to form a polysilazane-derived ceramic coating that protects the gas barrier layer.

The organic EL layer referred to in the present invention is formed from one or a plurality of organic layers including a light emitting layer. That is, the organic EL layer is a layer including at least a light emitting layer, and has a layer structure of one or more organic layers.
Usually, when the organic EL layer is formed by a wet method by coating, it is difficult to stack a large number of layers due to the relationship with the solvent, and thus it is often formed by one or two organic layers. However, it is possible to further increase the number of layers by devising an organic material or combining a vacuum deposition method.

As an organic layer formed in the organic EL layer other than the light emitting layer, a carrier injection layer such as a hole injection layer or an electron injection layer can be mentioned. Further, as the other organic layer, a carrier transporting layer such as a hole transporting layer and an electron transporting layer can be mentioned. Usually, these are used as a carrier injecting layer by imparting a carrier transporting function to the carrier injecting layer. It is often formed integrally. Other examples of the organic layer formed in the EL layer include a layer such as a carrier block layer for preventing penetration of holes or electrons and improving recombination efficiency.

Examples of the light emitting material used for the light emitting layer which is essential for the organic EL layer in the present invention include the following.

Examples of the dye-based luminescent material include cyclopentadiene derivative, tetraphenylbutadiene derivative, triphenylamine derivative, oxadiazole derivative, pyrazoloquinoline derivative, distyrylbenzene derivative, distyrylarylene derivative, silole derivative, thiophene ring compound. , Pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, pyrazoline dimers and the like.

As the metal complex light emitting material, aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazole zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin zinc complex,
For central metals such as europium complex, Al, Zn, Be
Or a metal complex having a rare earth metal such as Tb, Eu or Dy and having an oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure or the like as a ligand.

Further, as the polymer light emitting material, polyparaphenylene vinylene derivative, polythiophene derivative, polyparaphenylene derivative, polysilane derivative, polyacetylene derivative, polyvinylcarbazole, polyfluorenone derivative, polyfluorene derivative, polyquinoxaline derivative, and them. And the like.

A doping agent may be added to the above light emitting layer for the purpose of improving the light emitting efficiency and changing the light emitting wavelength. Examples of such a doping agent include a perylene derivative, a coumarin derivative, a rubrene derivative, a quinacridone derivative, a squarylium derivative, a porphyrin derivative, a styryl dye, a tetracene derivative, a pyrazoline derivative, decacyclene, phenoxazone, a quinoxaline derivative, a carbazole derivative, and a fluorene derivative. Can be mentioned.

As the material for forming the hole injection layer, in addition to the compounds exemplified as the light emitting material for the light emitting layer, phenylamine type, starburst type amine type, phthalocyanine type, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide are used. And oxides thereof, amorphous carbon, polyaniline, polythiophene, and other derivatives.

As the material for forming the electron injection layer, in addition to the compounds exemplified as the light emitting material for the light emitting layer, aluminum, lithium fluoride, strontium, magnesium oxide, magnesium fluoride, strontium fluoride, calcium fluoride, Barium fluoride, aluminum oxide,
Strontium oxide, calcium, sodium polymethylmethacrylate polystyrene sulfonate, lithium,
Alkali metals such as cesium and cesium fluoride,
And alkali metal halides, alkali metal organic complexes, and the like.

6. Second Electrode Layer The second electrode layer is usually formed on the organic EL layer thus formed by a vapor deposition method. This second electrode layer is
There is no particular limitation as long as it is composed of a material formed by a vapor deposition method. Specifically, magnesium alloys such as MgAg, aluminum alloys such as AlLi, AlCa, and AlMg, alkali metals and alkaline earth metals such as Li and Ca, and alloys of these alkali metals and alkaline earth metals. Metals having a small work function such as

7. Sealing Base Material As shown in FIG. 1, a sealing base material 7 may be formed for the purpose of covering and sealing the above-mentioned first electrode layer 4, organic EL layer 5, and second electrode layer 6. . The sealing base material may be, for example, a resin film, but is not limited thereto. Usually, in an EL element, light is often emitted to the resin base material 1 side, and in this case, the sealing base material may be opaque.

As specific materials, those listed in the section of the resin base material can be used.

In the present invention, the inner surface of this sealing substrate,
That is, it is preferable that a ceramic coating derived from polysilazane is also formed on the surface of the organic EL layer side. As shown in FIG. 1, the sealing base material 7 includes a resin base material 1 and an organic E
Adhesion is performed around the region where the L layer 5 is formed, and sealing is performed. At this time, the ceramic coating 3 derived from the polysilazane is formed on the resin base material 1,
The sealing substrate 7 will adhere to this ceramic coating 3. Here, the ceramic coating derived from polysilazane has characteristics that it has high adhesiveness with an adhesive and is difficult to peel off.

Therefore, by forming a ceramic coating derived from polysilazane on both the resin base material side and the sealing base material side in this way, the resin base material and the sealing base material are bonded using an adhesive. This has the advantage that good adhesive properties can be obtained.

8. Manufacturing Method of EL Element Next, a manufacturing method of the EL element of the present invention will be briefly described. In the present invention, as shown in FIG. 1, the gas barrier layer 2 is formed on the resin base material 1. This gas barrier layer is preferably formed by a vacuum film forming method, but considering that it is a resin base material, it is preferably a film forming method capable of forming a film even at a low temperature. Therefore, in the present invention, it is preferable that the gas barrier layer is formed by the plasma CVD method capable of forming a film at a relatively low temperature. In this case, it is preferable to use silicon oxide as the material because it is transparent and has a good gas barrier property. Therefore, the gas barrier layer used in the present invention is preferably a silicon oxide film formed by the plasma CVD method.

After the gas barrier layer is formed in this way, a ceramic film derived from polysilazane is formed. This ceramic film is formed by applying the above-mentioned polysilazane coating solution on the gas barrier layer, drying it sufficiently, and heating it in the presence of a basic substance such as ammonia to form a ceramic film at low temperature. Is possible.

In the present invention, the heating temperature at this time is about 50 ° C to 200 ° C, preferably 70 ° C to 17 ° C.
It is fired at a temperature in the range of 0 ° C. By firing at a low temperature in this way, deterioration of the resin base material can be prevented.

The first electrode layer is formed in a pattern on the ceramic film derived from polysilazane thus formed. The developing step in the patterning of the first electrode layer at this time is preferably performed by a wet method as described above. This is because the protection of the gas barrier layer in this developing step is the main purpose of forming the ceramic coating derived from polysilazane.

Then, on the ceramic film derived from polysilazane thus formed, by a usual method,
The EL element of the present invention can be obtained by forming the organic EL layer and the second electrode layer, and then sealing with the sealing base material 7 as described above, for example.

The present invention is not limited to the above embodiment. The above-described embodiments are merely examples, and the present invention has substantially the same configuration as the technical idea described in the scope of claims of the present invention, and has any similar effects to the present invention. It is included in the technical scope of.

[0104]

EXAMPLES The present invention will be further described with reference to the following examples.

Example 1 (Formation of Gas Barrier Layer) A silicon oxide film was formed by a vacuum film forming method on a PET film substrate having a size of 2 inches square and a thickness of 188 μm. The oxygen transmission rate is 0.30 cc / m ² / day,
The water vapor transmission rate was 0.10 g / m ² / day.
The measurement conditions of oxygen permeability are OX-TRAN2 / 20 from MOCON.
Using a mold, the conditions are 23 ° C. and 90% RH, and the conditions for measuring the water vapor transmission rate are 40% using a PERMATRAN of MOCON.
The conditions were 90 ° C and 90% RH.

(Formation of Polysilazane-Derived Ceramics Coating) Polysilazane coating liquid (manufactured by Clariant Japan Co., Ltd.) on the PET film substrate on which the gas barrier layer is formed.
Product name: N-D820), 0.5 ml was dropped, and 200
Spin coated at 0 rpm for 5 seconds. After that, 100 ℃
And was baked for 1 hour to obtain a ceramic film having a film thickness of 500 nm. The same operation was repeated once again to obtain a polysilazane-derived ceramic coating having two layers.

(Patterning of First Electrode Layer) An indium tin oxide (ITO) electrode was formed on the ceramic film derived from polysilazane by a sputtering method, and a positive photoresist (manufactured by Tokyo Ohka Kogyo; OFPR-800) was formed. Used, ITO etchant (hydrochloric acid: nitric acid = 3: 1 solution)
Was developed and patterned.

The oxygen transmission rate of the substrate after patterning is
0.30 cc / m ² / day, water vapor transmission rate is 0.1
It was 0 g / m ² / day. The measurement is similar to the method described above.

(Formation of Light Emitting Layer) 0.5 ml of a 1.5 wt% solution of 1,1,2-trichloroethane in a mixture of PVK: tBuPBD: coumarin 6 = 70: 30: 1 was dropped on a PET film on which ITO was patterned. And then 250
Spin coating was performed at 0 rpm for 5 seconds to obtain a light emitting layer having a thickness of 100 nm.

The chemical formulas of PVK, tBuPBD, and coumarin 6 are shown below as (1), (2), and (3), respectively.

[0111]

[Chemical 2]

(Formation of Second Electrode Layer) One co-deposition layer of Mg: Ag = 10: 1 was formed on the upper surface of the light emitting layer by a vacuum deposition method.
After vapor deposition of 00 nm, Ag was vapor deposited to 200 nm as a protective layer.

(Sealing) A glass plate having a thickness of 1.5 inches □ and 1.1 mm was bonded to the manufactured EL element using a UV curable resin under a pure nitrogen atmosphere.

(Evaluation of Luminescent Characteristics of EL Element) The ITO electrode layer side was connected to the positive electrode and the Ag electrode layer side was connected to the negative electrode, and a direct current was applied by a source meter. Light emission was observed when 10 V was applied. The diameter of the dark spot was 10 μm.

As a result of observing the light emitting portion after 24 hours, the diameter of the dark spot was 10 μm, and the growth of the dark spot was not observed.

[Example 2] (Production of EL element) [0116] Similar to the method of Example 1, except that the glass plate was used as the sealing substrate instead of the barrier film on which the polysilazane-derived ceramic coating was formed, An EL device was obtained in the same manner as in Example 1.

(Evaluation of Luminescent Properties of EL Element) The ITO electrode layer side was connected to the positive electrode and the Ag electrode layer side was connected to the negative electrode, and a direct current was applied by a source meter. Light emission was observed when 10 V was applied. The diameter of the dark spot was 10 μm.

As a result of observing the light emitting portion after 24 hours, the diameter of the dark spot was 10 μm, and the growth of the dark spot was not observed.

[Comparative Example 1] Example 1 was repeated except that the ceramic coating derived from polysilazane was not formed on the substrate.
An EL device was produced in the same manner as in.

As a result, the oxygen transmission rate of the substrate after patterning the ITO electrode layer was 4.80 cc / m ² / day,
The water vapor transmission rate was deteriorated to 3.40 g / m ² / day. The measurement is similar to the method described above.

The dark spots after 24 hours were 5
It was 00 μm, and growth of dark spots was observed.

[Comparative Example 2] Example 2 was repeated except that the ceramic coating derived from polysilazane was not formed on the substrate.
An EL device was produced in the same manner as in.

As a result, the oxygen transmission rate of the substrate after patterning the ITO electrode layer was 4.80 cc / m ² / day,
The water vapor transmission rate was deteriorated to 3.40 g / m ² / day. The measurement is similar to the method described above.

The dark spots after 24 hours were 5
It was 00 μm, and growth of dark spots was observed.

Comparative Example 3 An EL device was produced in the same manner as in Example 2 except that the ceramic film derived from polysilazane was not formed on the sealing substrate. As a result, 24
The dark spot after the lapse of time was 100 μm, and the growth of the dark spot was observed. Further, the adhesion between the sealing base material and the UV curable resin as the adhesive was poor, and the sealing material was easily peeled off.

[0126]

According to the present invention, by providing a ceramic coating derived from polysilazane on the gas barrier layer,
For example, even when the first electrode layer such as an ITO film is patterned by the wet method, the gas barrier layer formed on the base material is not corroded, and the original gas barrier property can be maintained. It is possible to prevent the deterioration of the layer.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an EL element of the present invention.

[Explanation of symbols]

1 ... Resin base material 2 ... Gas barrier layer 3… Ceramics coating 4 ... First electrode layer 5 ... Organic EL layer 6 ... Second electrode layer 7 ... Sealing base material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshio Yoshihara             1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo             Dai Nippon Printing Co., Ltd. F term (reference) 3K007 AB00 AB03 AB06 AB13 BB01                       CA00 CA02 CA05 CB01 DA00                       DB03 EB00 FA01 FA02 FA03

Claims (3)

[Claims] 1. A resin base material, a gas barrier layer formed on the resin base material, a polysilazane-derived ceramic coating formed on the gas barrier layer, and a pattern formed on the ceramic coating. A first electrode layer,
An electroluminescent device comprising: an organic EL layer having at least a light emitting layer formed on the first electrode layer; and a second electrode layer formed on the organic EL layer. 2. Further, it is sealed with a sealing base material,
The electroluminescent element according to claim 1, wherein a ceramic coating derived from polysilazane is formed on the inner surface of the sealing base material. 3. A polysilazane-containing coating liquid is applied to a resin base material on which a gas barrier layer is formed, and the temperature is 50 ° C. to 20 ° C.
A method for manufacturing an electroluminescent element, which comprises a step of firing at a temperature within a range of 0 ° C.