JP2007095572A - Barrier substrate for organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrier substrate for an organic EL element which can make an excellent image display without a defect such as a dark spot, and to provide an organic EL display device. <P>SOLUTION: The barrier substrate for an organic EL element is composed of a substrate and a first inorganic insulating layer of an eavporated membrane formed on the above substrate and a second inorganic insulating layer of an ultra-fine-particle film formed on the above first inorganic insulating layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a barrier substrate for an organic electroluminescence element used in an organic electroluminescence display device.

  An organic electroluminescence (hereinafter, abbreviated as “organic EL”) element has high luminous efficiency such as high luminance emission even when the applied voltage is less than 10 V, and can emit light with a simple element structure. Therefore, application to image display devices is expected, and research is actively conducted. In particular, the organic EL element has high visibility due to self-coloring, is different from a liquid crystal display in that it is an all-solid-state display, has excellent impact resistance, is less affected by temperature changes, and has a large viewing angle. In recent years, it has been put to practical use as a light emitting element in an image display device.

  What is important in putting an organic EL element into practical use as a light-emitting element in an image display device is that the organic EL element has a fine display function and long-term stability. However, some organic EL elements have a drawback that when they are driven for a certain period, the light emission characteristics such as current-luminance characteristics are remarkably deteriorated.

A typical cause of the deterioration of the light emission characteristics is the growth of light emission defect points called dark spots. This dark spot is considered to be caused by oxidation or aggregation of constituent materials of each layer constituting the organic EL element due to oxygen or moisture in the organic EL element. The growth of the dark spot proceeds not only during energization (during driving) but also during storage, and in an extreme case spreads over the entire light emitting surface. The growth is particularly accelerated by (1) oxygen or moisture present around the organic EL element, (2) affected by oxygen or moisture present as an adsorbate in each layer, and (3) the organic EL element. It is considered that it is also affected by moisture adsorbed on the parts used at the time of production or moisture permeation at the time of production.
In addition, a gas generated by decomposition of a pigment contained in a colored layer, a color conversion layer, or the like that constitutes the organic EL element at the time of heating during the production of the organic EL element also causes a dark spot.

As a technique for preventing the moisture, oxygen and gas from entering the organic EL layer, a method of providing a transparent barrier layer such as a transparent inorganic film or a resin film has been proposed (see, for example, Patent Documents 1 to 5).
However, the transparent inorganic film is generally formed by a sputtering method, a vacuum deposition method, or the like, and it is technically difficult to obtain a transparent inorganic film free from foreign matters such as particles and pinholes by such a method. . For this reason, the transparent inorganic film has insufficient moisture resistance and barrier properties for preventing deterioration of the organic EL element. Therefore, although a method of increasing the barrier property by adopting a thick transparent inorganic film is employed, there is a problem that the cost becomes very high.
In addition, when a resin film is used as the transparent barrier layer, dark spots due to pinholes can be prevented, but the resin film expands and contracts due to thermal expansion, etc., so when forming a transparent electrode layer or a colored layer There is a problem that displacement occurs and pixel reduction occurs from the end of the transparent electrode layer.

JP 2002-1000046 A JP 2002-117976 A JP 2002-134268 A JP 2002-175880 A JP 2002-184578 A

  The present invention has been made in view of the above problems, and has as its main object to provide a barrier substrate for an organic EL element and an organic EL display device capable of displaying a good image without defects such as dark spots. To do.

  In order to achieve the above object, the present invention is formed of a substrate, a first inorganic insulating layer that is a vapor deposition film formed on the substrate, and an ultrafine particle formed on the first inorganic insulating layer. Provided is a barrier substrate for an organic EL element, comprising a second inorganic insulating layer which is a film.

According to the present invention, since the second inorganic insulating layer is a film formed of ultrafine particles, even if a defect such as a pinhole exists in the first inorganic insulating layer that is a vapor deposition film, pinholes or the like are formed by the ultrafine particles. Can block defects. For this reason, it can prevent that water vapor | steam, oxygen, etc. permeate from defects, such as a pinhole of a 1st inorganic insulating layer. Therefore, when the organic EL element barrier substrate of the present invention is used in an organic EL display device, it is possible to suppress the occurrence of dark spots. In addition to the surface defects such as pinholes and foreign matters, the deposited film also has structural defects. Such defective portions are structurally weak, but the ultrafine particles are structurally weak due to the size effect of the ultrafine particles. Since it enters a weak part, the packing density of a vapor deposition film can be improved and barrier property can be improved.
Further, by providing the second inorganic insulating layer on the first inorganic insulating layer, it is possible to prevent the intrusion of water vapor or oxygen as described above. Therefore, in order to obtain a barrier property, a thick film is formed by a sputtering method or a vacuum evaporation method. The transparent barrier layer need not be provided, and the manufacturing cost can be reduced.
Further, when the second inorganic insulating layer is formed by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature is set to a normal sintering temperature due to the size effect unique to the ultrafine particles. For example, it is possible to perform firing at a temperature lower than the heat resistant temperature of the colored layer.

  Moreover, in this invention, the said 1st inorganic insulating layer may consist of a some vapor deposition film. This is because the barrier property can be further improved by laminating a plurality of deposited films (first inorganic insulating layer) and a film (second inorganic insulating layer) formed of ultrafine particles.

  Furthermore, in the present invention, the sintering temperature of the ultrafine particles is preferably 350 ° C. or lower. This is because by using ultrafine particles having a sintering temperature in the above range, when the second inorganic insulating layer is formed by applying and baking an ultrafine particle dispersion, it can be fired at a lower temperature.

The ultrafine particles are preferably at least one kind of ultrafine particles selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride. This is because the insulating properties can be improved by using these ultrafine particles.
Furthermore, it is also preferable that the ultrafine particles are at least one kind of ultrafine particles selected from the group consisting of indium, alkali metal, and alkaline earth metal whose surface is oxidized. This is because indium, alkali metal, and alkaline earth metal are highly oxidizable, so that oxidation is promoted even by firing at a relatively low temperature.

  Furthermore, the average particle size of the ultrafine particles is preferably in the range of 0.5 nm to 100 nm. This is because ultrafine particles having an average particle size that is too small are difficult to manufacture, and if the average particle size of the ultrafine particles is too large, it may be difficult to block defects such as pinholes in the first inorganic insulating layer.

  In the present invention, a colored layer may be formed between the substrate and the first inorganic insulating layer. Furthermore, a color conversion layer may be formed between the substrate and the first inorganic insulating layer. Furthermore, a transparent protective layer having an uneven shape may be formed between the substrate and the first inorganic insulating layer. According to the present invention, the barrier property is manifested by laminating the first inorganic insulating layer and the second inorganic insulating layer. Outflow can be prevented.

  The present invention also includes a first inorganic insulating layer forming step of forming at least one vapor-deposited film on a substrate, and an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent on the first inorganic insulating layer. There is provided a method for producing a barrier substrate for an organic EL element, comprising a second inorganic insulating layer forming step of baking to form a film.

According to the present invention, even when defects such as pinholes are present in the first inorganic insulating layer, which is a deposited film, the second inorganic insulating layer is formed by applying the ultrafine particle dispersion on the first inorganic insulating layer. Fine particles can close defects such as pinholes. Therefore, an organic EL element barrier substrate having excellent barrier properties can be obtained. Further, it is not necessary to provide a thick transparent barrier layer by a sputtering method or a vacuum vapor deposition method as in the prior art, so that the manufacturing cost can be reduced and the yield can be improved.
Furthermore, according to the present invention, in the second inorganic insulating layer forming step, sintering can be performed at a temperature lower than the normal temperature due to the size effect unique to the ultrafine particles. As a result, for example, the colored layer can be fired at a temperature lower than the heat resistant temperature.

  In the said invention, it is preferable to bake in the atmosphere which the said ultrafine particle does not oxidize at the said 2nd inorganic insulating layer formation process, and to bake in oxidizing atmosphere after that. This is because the ultrafine particles can be sufficiently sintered to form a dense film.

  In the present invention, in the first inorganic insulating layer forming step, after forming a lower vapor deposition film on the substrate and polishing the lower vapor deposition film surface, the upper vapor deposition film is formed on the lower vapor deposition film. Can be formed. For example, when foreign matter exists on the surface of the lower vapor deposition film, the foreign matter can be removed by polishing, and by further forming a vapor deposition film thereon, the barrier property of the portion where the foreign matter was present can be reinforced. is there.

  Furthermore, in the present invention, the boiling point of the solvent is preferably 120 ° C. or higher. If the boiling point of the solvent is relatively high, it is possible to prevent the solvent from evaporating at the time of drying after application of the ultrafine particle dispersion, thereby preventing the ultrafine particles from agglomerating and losing the flatness of the film. Because it can.

  The present invention also provides a barrier substrate for an organic EL element, a transparent electrode layer formed on the second inorganic insulating layer of the barrier substrate for an organic EL element, and formed on the transparent electrode layer. An organic EL display device having an organic EL layer including a light emitting layer and a back electrode layer formed on the organic EL layer is provided.

  Since the organic EL display device of the present invention uses the above-described barrier substrate for organic EL elements, it is possible to suppress the occurrence of defects such as dark spots and to display a good image. Further, since there is no need to provide a thick transparent barrier layer by sputtering or vacuum deposition as in the prior art, an organic EL display device can be provided at low cost.

  According to the present invention, since the second inorganic insulating layer, which is a film formed of ultrafine particles, is formed on the first inorganic insulating layer, which is a vapor deposition film, the pin existing in the first inorganic insulating layer by the ultrafine particles. Defects such as holes can be blocked, and the outflow of gas generated from the colored layer or the like and the intrusion of water vapor or oxygen can be prevented. Therefore, when the barrier substrate for organic EL elements of the present invention is used in an organic EL display device, the occurrence of dark spots can be suppressed and good image display can be achieved.

  Hereinafter, the barrier substrate for an organic EL element of the present invention, a manufacturing method thereof, and an organic EL display device will be described in detail.

A. First, the barrier substrate for organic EL elements of the present invention will be described.
The barrier substrate for an organic EL element of the present invention is formed of a substrate, a first inorganic insulating layer that is a vapor deposition film formed on the substrate, and an ultrafine particle formed on the first inorganic insulating layer. It has the 2nd inorganic insulating layer which is a film | membrane, It is characterized by the above-mentioned.

The barrier substrate for an organic EL device of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a barrier substrate for an organic EL device of the present invention. As shown in FIG. 1, the barrier substrate 10 for an organic EL element of the present invention is obtained by sequentially laminating a first inorganic insulating layer 2 and a second inorganic insulating layer 3 on a substrate 1.
The first inorganic insulating layer is a vapor deposition film, and the second inorganic insulating layer is a film formed of ultrafine particles. In general, a deposited film formed by a deposition method such as a sputtering method or a vacuum deposition method often includes foreign matters such as particles or pinholes. However, in the present invention, the deposited film is formed on the first inorganic insulating layer which is a deposited film. Since the second inorganic insulating layer, which is a film made of fine particles, is laminated, defects on the production surface of the deposited film, microscopic structural defects, etc. can be closed with ultrafine particles, and barrier properties against water vapor and oxygen Can be obtained.
Further, the deposited film has structural defects in addition to surface defects such as pinholes and foreign matters, and such defective portions are structurally weak portions. In addition, when the foreign matter in the vapor deposition film is removed by polishing and a vapor deposition film is further formed thereon, a layer without pinholes can be formed, but the portion where the foreign matter has been removed by polishing is the upper layer. Even if it is covered with a deposited film, it is structurally weak. On the other hand, according to the present invention, since the ultrafine particles enter the structurally weak part due to the size effect of the ultrafine particles, the filling density of the deposited film can be improved and the barrier property can be improved.

In the present invention, it is preferable that a layer formed of an organic material is formed between the substrate and the first inorganic insulating layer. When a layer formed of an organic material is exposed to a high temperature, gas may be generated due to decomposition of the organic material, which causes dark spots, but the first inorganic insulating layer and the second inorganic insulating layer are laminated. This is because the barrier property is exhibited even for such a gas. Examples of the layer formed of an organic material include a colored layer, a color conversion layer, a light shielding portion, a planarization layer, a transparent protective layer, and the like. The barrier substrate for an organic EL device of the present invention has an excellent barrier property against a gas generated from a colored layer or the like.
Therefore, when the barrier substrate for organic EL elements of the present invention is used in an organic EL display device, good image display without dark spots is possible.

  In addition, when the second inorganic insulating layer is formed by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature is set at a normal sintering temperature due to the size effect unique to the ultrafine particles. The temperature can be lowered as compared with the temperature, and for example, baking at a temperature lower than the heat-resistant temperature of the colored layer becomes possible. As a result, the layers made of organic materials, such as colored layers, color conversion layers, light-shielding portions, planarization layers, transparent protective layers, etc., are not adversely affected, and the choice of materials used for these layers is narrowed. In addition, the barrier property can be improved.

Furthermore, in the present invention, by providing the first inorganic insulating layer and the second inorganic insulating layer, it is possible to obtain a barrier property against gas generated from water vapor, oxygen, a colored layer, and the like. Further, since it is not necessary to provide a thick transparent barrier layer by vacuum evaporation, the cost can be reduced and the yield can be improved.
Hereinafter, each structure of such a barrier substrate for organic EL elements will be described.

1. 2nd inorganic insulating layer The 2nd inorganic insulating layer used for this invention is a film | membrane formed on the 1st inorganic insulating layer mentioned later, and was formed with the ultrafine particle.
Here, the “film formed of ultrafine particles” refers to a film obtained by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent. A film formed of ultrafine particles can be confirmed by a scanning electron microscope (SEM) observation photograph (magnification: 50,000 times or more). FIGS. 2A and 2B show examples of SEM photographs of the cross section and top surface of the film formed of ultrafine particles, respectively. For comparison, FIG. 3 shows an example of a SEM photograph of a cross section of a deposited film formed by sputtering. As illustrated in FIG. 3, columnar particles can be confirmed in the cross section in the deposited film. On the other hand, as illustrated in FIG. 2, in the film formed of ultrafine particles, columnar particles cannot be confirmed on either the top surface or the cross section. Therefore, in the SEM photograph of the cross section of the second inorganic insulating layer, when columnar particles cannot be confirmed, it can be said that the second inorganic insulating layer is a film formed of ultrafine particles.
When a film formed of ultrafine particles is formed on the deposited film, the deposited film and the film formed of ultrafine particles can be discriminated from the above observation photograph, but are discriminated as follows. You can also. Since the film formed of ultrafine particles is a coating film, for example, when there is a step due to a colored layer, the coating film becomes thick because liquid can be accumulated in the step portion. On the other hand, since the deposited film does not become thick at the stepped portion, it can be determined that the second inorganic insulating layer is a coating film formed of ultrafine particles.
In addition, although the film formed by the sol-gel method cannot confirm columnar particles, the sol-gel method applies a coating liquid that is a liquid at a molecular level and cures it to form a film. Since a film is formed by sintering ultrafine particles, a film formed by a sol-gel method and a film formed by ultrafine particles are structurally different. Note that the difference in film structure can be confirmed by high-magnification SEM observation.

  The “ultrafine particles” are fine particles made of an inorganic material having an average particle diameter of 100 nm or less, and are fine particles that are individually and uniformly dispersed in a dispersion medium. For such ultrafine particles, reference can be made to JP-A Nos. 2002-121437 and 2005-81501.

  The ultrafine particles used in the present invention may have any insulating property, but it is preferable that the ultrafine particles have transparency. This is because when the barrier substrate for organic EL elements of the present invention is used in an organic EL display device, light is extracted from the substrate side. Examples of such ultrafine particles include inorganic oxides, inorganic nitrides, and inorganic oxynitride ultrafine particles. Specifically, inorganic oxides include indium oxide, silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, magnesium oxide, tin oxide, yttrium oxide, germanium oxide, calcium oxide, boron oxide, strontium oxide, and oxide. Examples include barium, lead oxide, zirconium oxide, sodium oxide, lithium oxide, and potassium oxide. Examples of the inorganic nitride include silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride. Examples of inorganic oxynitrides include silicon oxynitride. These may be used alone or in combination of two or more. Further, a mixed system of inorganic oxide and inorganic nitride may be used.

  Among these, at least one ultrafine particle selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride is preferably used. This is because the insulating properties can be improved by using these ultrafine particles. In addition, when the second inorganic insulating layer is formed by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature can be lowered by using ultrafine particles of indium oxide. Because it can be done. In addition, a film formed of silicon oxide, silicon nitride, and silicon oxynitride ultrafine particles has good adhesion to the first inorganic insulating layer and the like.

  Moreover, as the ultrafine particles, ultrafine particles of metal whose surface is oxidized can also be used. Specifically, the metals include In, Al, Ti, Ta, Zn, Sn, Y, Ge, Pb, Zr, alkali metals (Li, Na, K), alkaline earth metals (Mg, Ca, Sr, Ba). ) And the like. Among these, at least one kind of ultrafine particles selected from the group consisting of In (indium), alkali metals, and alkaline earth metals is preferably used. This is because indium, alkali metal, and alkaline earth metal are highly oxidizable, so that oxidation is promoted even by firing at a relatively low temperature.

The ultrafine particles preferably have a sintering temperature of 350 ° C. or lower. Here, sintering refers to a phenomenon in which when an aggregate of ultrafine particles is heated to a high temperature, it is baked and solidified into a dense polycrystalline body. The ultrafine particles are in a thermodynamically non-equilibrium state, and mass transfer occurs in the direction of decreasing the surface area. As a result, bonding occurs between the particles and the particles become dense. That is, the driving force for sintering is a force that attempts to minimize the surface energy of the system. The sintering temperature is a temperature at which the ultrafine particles become dense and baked when the aggregate of ultrafine particles is heated at a temperature below the melting point of the ultrafine particles. By using ultrafine particles having a sintering temperature in the above range, the firing temperature when forming the second inorganic insulating layer can be lowered. In addition, the lower the sintering temperature of the ultrafine particles, the better, but the lower limit is usually about 180 ° C. Some metals have a melting point of less than 180 ° C., and the sintering temperature of ultrafine particles containing such a metal is usually less than 180 ° C., but a metal having a melting point of less than 180 ° C. is very oxidized. The lower limit of the sintering temperature is within the above range because it is easy to do and leads to an increase in the sintering temperature.
Here, the sintering temperature can be measured by differential thermal analysis (DTA). In DTA, a temperature difference between a sample and a reference material (generally alumina) can be measured to obtain a transition temperature, and a temperature difference (sample) generated when heat is applied to the sample and the reference material. Thus, the sintering temperature can be determined. That is, when the sample and the reference material are heated in the same atmosphere, the temperature of the reference material is increased, whereas when the sample temperature is not increased, heat is applied to the sintering of the ultrafine particles. It can be said that an endothermic phenomenon has occurred. Therefore, the temperature at which the endothermic phenomenon is observed, that is, the endothermic start temperature in the DTA curve, is the sintering temperature in the present invention.
Note that a TG-DTA apparatus (TG 8120) manufactured by Rigaku is used for the measurement of the sintering temperature.

  Further, the ultrafine particles preferably contain a metal having a melting point of about 700 ° C. or lower. This is because if the melting point of a single metal is relatively low as in the above range, the sintering temperature of the ultrafine particles is expected to be relatively low. Examples of such metal include Al (660 ° C.), In (156.4 ° C.), Mg (651 ° C.), Sn (231.85 ° C.), Zn (419.43 ° C.), Pb (327.5 ° C.). ), Na (97.5 ° C.), Li (186 ° C.), K (62.3 ° C.) and the like. The numbers in parentheses are melting points.

  The ultrafine particles may be the same material as or different from the material used for the first inorganic insulating layer described later, but are preferably the same material. This is because the same material can reduce the film stress and has good adhesion.

In addition, the average particle size of the ultrafine particles may be any as long as it can close defects such as pinholes in the first inorganic insulating layer, and is specifically preferably in the range of 0.5 nm to 100 nm. More preferably, it is in the range of 1 nm to 50 nm, and more preferably 1 nm to 10 nm. If the average particle size is too small, it is difficult to produce. On the other hand, if the average particle size is too large, it may be difficult to block defects such as pinholes in the first inorganic insulating layer. This is because a decrease in sintering temperature due to the effect cannot be expected.
In addition, the said average particle diameter can be confirmed with a scanning electron microscope (SEM) observation photograph (high magnification).

In addition, when the barrier substrate for an organic EL element of the present invention is used in an organic EL display device, the second inorganic insulating layer preferably has transparency because light is extracted from the substrate side. Specifically, the transmittance of the second inorganic insulating layer in the visible light region is preferably 60% or more, more preferably 80% or more, and particularly preferably 90% or more.
In addition, the said transmittance | permeability is an average value of the value measured using Shimadzu Corporation Corp. UV-3100 within the wavelength range of 380 nm-800 nm.

  The film thickness of the second inorganic insulating layer is not particularly limited as long as it can close defects such as pinholes in the first inorganic insulating layer and satisfy the above transparency, Specifically, it can be set within a range of 5 nm to 2000 nm, and preferably within a range of 50 nm to 500 nm. This is because if the film thickness of the second inorganic insulating layer is too thick, the transmittance may be lowered, or peeling from the first inorganic insulating layer may occur. On the other hand, if the film thickness of the second inorganic insulating layer is too thin, it is difficult to block pinholes and the like existing in the first inorganic insulating layer.

In the present invention, it is preferable to form the second inorganic insulating layer by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent. That is, the second inorganic insulating layer is preferably a coating film formed of ultrafine particles. By forming the second inorganic insulating layer by such a method, the pinhole can be effectively blocked by the ultrafine particles, and the sintering temperature is reduced to, for example, the heat resistant temperature of the colored layer or less by the size effect peculiar to the ultrafine particles. Can be lowered.
In addition, since the formation method of a 2nd inorganic insulating layer is described in the term of "B. Manufacturing method of the barrier property board | substrate for organic EL elements" mentioned later, description here is abbreviate | omitted.

2. 1st inorganic insulating layer The 1st inorganic insulating layer used for this invention is a vapor deposition film.
The method for forming the first inorganic insulating layer is not particularly limited as long as it is a vapor deposition method. In addition, since the formation method of a 1st inorganic insulating layer is described in the term of "B. The manufacturing method of the barrier property board | substrate for organic EL elements" mentioned later, description here is abbreviate | omitted.

Although the said 1st inorganic insulating layer should just have insulation, it is preferable to have transparency further. Examples of the material used for the first inorganic insulating layer include inorganic oxides, inorganic nitrides, and inorganic oxynitrides. Specifically, inorganic oxides include indium oxide, silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, magnesium oxide, tin oxide, yttrium oxide, germanium oxide, calcium oxide, boron oxide, strontium oxide, and oxide. Examples include barium, lead oxide, zirconium oxide, sodium oxide, lithium oxide, and potassium oxide. Examples of the inorganic nitride include silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride. Examples of inorganic oxynitrides include silicon oxynitride. These may be used alone or in combination of two or more.
Among these, at least one selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride is preferably used. This is because these materials have good adhesion to the substrate and the second inorganic insulating layer.

  Further, the first inorganic insulating layer may be a single-layer vapor deposition film or may be a laminate of a plurality of vapor deposition films. FIG. 4 shows an example of a barrier substrate 10 for an organic EL element having a first inorganic insulating layer 2 in which two vapor-deposited films 12a and 12b are laminated. In the case where the pinhole P1 is present in the lower vapor deposition film 12a as illustrated in FIG. 4, for example, if the second inorganic insulating layer is formed directly on the vapor deposition film 12a, the barrier property of the pinhole P1 portion is lowered although not shown. there is a possibility. On the other hand, when two layers of vapor deposition films 12a and 12b are laminated as illustrated in FIG. 4, an upper vapor deposition film 12b is formed in the pinhole P1 portion of the lower vapor deposition film 12a. 2 Since the inorganic insulating layer 3 is formed, it is possible to prevent the barrier property of the pinhole P1 from being lowered. Even if the pinhole P2 is present in the upper vapor deposition film 12b, the lower vapor deposition film 12a is formed under the pinhole P2 portion of the upper vapor deposition film 12b, and the second inorganic insulating layer 3 is formed on the upper vapor deposition film 12b. Since it is formed, the deterioration of the barrier property of the pinhole P2 portion can be similarly prevented. When laminating a plurality of vapor deposition films, it is considered extremely rare that pinholes are generated in the same portion between the upper and lower vapor deposition films. Therefore, the first inorganic insulation layer and the second inorganic insulation layer composed of the plurality of vapor deposition films It is possible to further improve the barrier property. In addition to surface defects such as pinholes due to foreign substances, the deposited film has structural defects, etc. Even if the upper deposited film is formed, the pinhole part of the lower deposited film is structurally weak. Since the ultrafine particles enter such a structurally weak part, the filling density of the deposited film is improved and the barrier property is improved.

  When the first inorganic insulating layer is formed by laminating a plurality of vapor deposition films, the number of vapor deposition films is not particularly limited, but is usually about 2 to 4 layers, preferably 2 layers. Or three layers. This is because if the number of laminated layers is too large, the transmittance is lowered and the cost is increased. At this time, the combination of the deposited films to be stacked may be the same or different.

When the organic EL element barrier substrate of the present invention is used in an organic EL display device, light is extracted from the substrate side, and thus the first inorganic insulating layer preferably has transparency. Specifically, the transmittance of the first inorganic insulating layer in the visible light region is preferably 60% or more, more preferably 80% or more, and particularly preferably 90% or more.
In addition, about the measuring method of the said transmittance | permeability, it is the same as that of the method described in the term of the said 2nd inorganic insulating layer.

  The film thickness of the first inorganic insulating layer is not particularly limited as long as it satisfies the above transparency, and is appropriately selected depending on the above-described materials. Usually, it exists in the range of 5 nm-5000 nm, Preferably it exists in the range of 5 nm-500 nm. Further, when aluminum oxide or silicon oxide is used, it is more preferably in the range of 10 nm to 300 nm. This is because if the thickness of the first inorganic insulating layer is too thin, the barrier property may be lowered. On the other hand, if the film thickness of the first inorganic insulating layer is too thick, cracks or the like may occur during the formation of the first inorganic insulating layer, and the transmittance may decrease.

3. Layer formed of organic material In the present invention, a layer formed of an organic material is preferably formed between the substrate and the first inorganic insulating layer. This is because the barrier substrate for an organic EL element of the present invention has an excellent barrier property against a gas generated from a layer formed of an organic material. Examples of the layer formed of an organic material include a colored layer, a color conversion layer, a light shielding portion, a planarization layer, a transparent protective layer, and the like. Hereinafter, these layers will be described.

(1) Colored layer In this invention, the colored layer 4 may be formed between the board | substrate 1 and the 1st inorganic insulating layer 2 so that it may illustrate in FIG.
The colored layer is a layer that changes the color tone of light emitted from the light emitting layer of the organic EL display device when the organic EL display device is used as a barrier substrate for organic EL elements of the present invention, or a color conversion described later. This is a layer for further adjusting the color tone of the light transmitted through the layer. As illustrated in FIG. 5, the colored layer 4 generally includes a red colored pattern 4R, a green colored pattern 4G, and a blue colored pattern 4B. When the color conversion layer is provided, each coloring pattern is formed at a position corresponding to each color conversion pattern of the color conversion layer. By forming such a colored layer, when the organic EL element barrier substrate of the present invention is used in an organic EL display device, it is possible to achieve high-purity color development and high color reproducibility. be able to.

  In the colored layer, the pigment contained in the layer decomposes and gas may be generated, which causes dark spots. In the present invention, the first inorganic insulating layer and the second inorganic insulating layer are formed on the colored layer. By being provided, a barrier property can be obtained even for the gas generated from the colored layer.

As a material for forming the colored layer, pigments and binder resins that can be generally used for color filters can be used.
Examples of the pigment used in the red coloring pattern include perylene pigments, lake pigments, azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, and isoindoline pigments. These pigments may be used alone or in combination of two or more.
Examples of the pigment used in the green coloring pattern include halogen multi-substituted phthalocyanine pigments, halogen multi-substituted copper phthalocyanine pigments, triphenylmethane basic dyes, isoindoline pigments, and isoindolinone pigments. . These pigments may be used alone or in combination of two or more.
Examples of the pigment used in the blue coloring pattern include copper phthalocyanine pigments, indanthrene pigments, indophenol pigments, cyanine pigments, dioxazine pigments and the like. These pigments may be used alone or in combination of two or more.
The pigment is usually contained in each coloring pattern within a range of 5 to 50% by weight.

  The binder resin used for the colored layer is preferably a transparent resin having a visible light transmittance of 50% or more. As the transparent resin, for example, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, A maleic acid resin, a polyamide resin, etc. are mentioned. In the case of forming a colored layer using a photolithography method, a photosensitive resin is used as a transparent resin. For example, a reactive vinyl group such as an acrylate type, a methacrylate type, a polyvinyl cinnamate type, or a cyclic rubber type is used. An ionizing radiation curable resin (electron beam curable resin or ultraviolet curable resin) is used.

  As a method for forming the colored layer, a general method for forming a color filter, for example, a photolithography method, an ink jet method, a printing method, or the like can be used.

(2) Color conversion layer In the present invention, a color conversion layer may be formed between the substrate and the first inorganic insulating layer. As illustrated in FIG. 6, when the colored layer 4 is formed, the color conversion layer 5 (the red conversion pattern 5R, the green conversion pattern 5G, and the like is formed between the colored layer 4 and the first inorganic insulating layer 2. A blue conversion pattern 5B) is formed.
Similar to the colored layer, the color conversion layer may decompose the pigment contained in the color conversion layer to generate gas, which may cause dark spots. By providing the first inorganic insulating layer and the second inorganic insulating layer, barrier properties can be obtained not only for the gas generated from the colored layer but also for the gas generated from the color conversion layer.

  The color conversion layer used in the present invention absorbs light emitted from the light emitting layer of the organic EL element when the organic EL display device is used as a barrier substrate for an organic EL element of the present invention, and the visible light region fluorescence. As long as it is a layer containing a fluorescent material that emits light, and the light from the light emitting layer can be red, green, and blue, it is not particularly limited. The color conversion layer may be composed of, for example, color conversion patterns that emit red, green, and blue fluorescence, respectively. When a blue light emitting layer is used, a transparent resin is used instead of the blue conversion pattern. A pattern may be formed.

The color conversion layer usually contains an organic fluorescent dye that absorbs light from the light emitting layer and emits fluorescence and a binder resin.
The fluorescent dye used in the color conversion layer absorbs light in the near ultraviolet region or visible region emitted from the light emitting layer, particularly light in the blue or blue-green region, and emits visible light having different wavelengths as fluorescence. Usually, since a blue light emitting layer is used as the light emitting layer, it is preferable to use at least one fluorescent dye that emits fluorescence in the red region, and it is preferable to combine with one or more fluorescent dyes that emit fluorescence in the green region. .
That is, when a light emitting layer that emits light in the blue or blue-green region is used as the light source, if light from the light emitting layer is passed through a simple red colored layer to obtain light in the red region, the wavelength of the red region is originally Because there is little light, it becomes very dark light. Therefore, by converting the light in the blue or blue-green region from the light emitting layer into the light in the red region by the fluorescent dye, the light in the red region having sufficient intensity can be output.
On the other hand, the light in the green region may be output by converting the light from the light emitting layer into the light in the green region by another fluorescent dye, similarly to the light in the red region. In addition, when the light emission of the light emitting layer sufficiently includes light in the green region, the light from the light emitting layer may be simply output through the green colored layer.
Further, regarding the light in the blue region, the light of the light emitting layer may be converted and output using a fluorescent dye, but it is preferable to output the light of the light emitting layer through a simple blue colored layer.

Examples of fluorescent dyes that absorb light in the blue to blue-green region emitted from the light emitting layer and emit fluorescence in the red region include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11, Rhodamine dyes such as Basic Red 2, cyanine dyes, pyridine dyes such as 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1), Or an oxazine pigment | dye etc. are mentioned. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.
Examples of fluorescent dyes that absorb blue to blue-green light emitted from the light emitting layer and emit green light include 3- (2′-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6), 3- (2'-Benzimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 7), 3- (2'-N-methylbenzimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 30), 2, 3, 5 , 6-1H, 4H-tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), or the like, or basic yellow 51 which is a coumarin dye-based dye, and solvent Examples thereof include naphthalimide dyes such as yellow 11 and solvent yellow 116. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.
Fluorescent dyes are pre-kneaded in polymethacrylic acid ester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and a mixture of these resins. The pigment may be made into a fluorescent pigment. In addition, these fluorescent dyes and fluorescent pigments (hereinafter collectively referred to as fluorescent dyes together) may be used singly or in combination of two or more in order to adjust the hue of fluorescence. Good.

  The fluorescent dye is contained in an amount of 0.01 to 5% by weight, more preferably 0.1 to 2% by weight based on the weight of the color conversion pattern with respect to each color conversion pattern. If the fluorescent dye content is too low, sufficient wavelength conversion cannot be performed. On the other hand, if the fluorescent dye content is too high, the color conversion efficiency may decrease due to effects such as concentration quenching. is there.

  The binder resin used for the color conversion layer is preferably a transparent resin having a visible light transmittance of 50% or more. As the transparent resin, for example, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, Examples thereof include maleic acid resins and polyamide resins. In the case of forming a color conversion layer using a photolithography method, a photosensitive resin is used as the transparent resin, and for example, a reactive vinyl group such as an acrylate type, a methacrylate type, a polyvinyl cinnamate type, or a cyclic rubber type is used. An ionizing radiation curable resin (electron beam curable resin or ultraviolet curable resin) having the following is used.

  As a method for forming the color conversion layer, a general method for forming a color filter, for example, a photolithography method, an inkjet method, a printing method, or the like can be used.

(3) Light-shielding part In this invention, the light-shielding part may be formed between each coloring pattern which comprises a colored layer. This is because providing a light-shielding portion such as a black matrix can improve contrast when an organic EL display device is formed using the organic EL element barrier substrate of the present invention.

Examples of the material for forming the light shielding part include a resin containing a black colorant such as carbon black and titanium black.
Further, as a method for forming the light shielding portion, for example, a photolithography method or the like can be used.
The thickness of the light shielding part is preferably about 0.5 μm to 2 μm.

  Here, since the resin containing the black colorant used in the light shielding part may have a light shielding property, sufficient heat treatment can be performed unlike the colored layer. For this reason, a degassing component can be removed at the time of light shielding part formation.

Further, the light shielding portion may not be formed of an organic material, and may be formed using, for example, chromium, chromium oxide, chromium nitride, or the like.
As a method for forming such a light-shielding portion, for example, a thin film can be formed by a sputtering method, a vacuum evaporation method, or the like, and can be formed in a pattern using a photolithography method. Alternatively, it can be formed using an electroless plating method, a printing method, or the like.
The thickness of the light shielding portion using chromium or the like is preferably about 0.2 μm to 0.4 μm.

(4) Flattening layer In the present invention, a flattening layer may be formed on the colored layer or the color conversion layer. The flattening layer is provided for the purpose of protecting the colored layer and the color conversion layer, and for the purpose of flattening the irregularities on the surface of the colored layer and the color conversion layer.
In the present invention, the planarization layer may cause gas to be generated by decomposition of organic components and the like contained in the planarization layer, similar to the above-described colored layer and color conversion layer. By providing the first inorganic insulating layer and the second inorganic insulating layer on the planarizing layer, not only the gas generated from the coloring layer and the color conversion layer but also the gas generated from the planarizing layer is a barrier. Sex can be obtained.

  The planarization layer used in the present invention can be formed using a transparent resin. As transparent resin, what is used as binder resin of said colored layer or a color conversion layer is mentioned as a preferable thing.

  The thickness of the flattening layer is not particularly limited as long as the surface of the colored layer can be flattened, and can be specifically set within a range of 1 μm to 10 μm, preferably within a range of 2 μm to 4 μm. is there. Further, when the color conversion layer is formed, the thickness of the planarization layer is preferably in the range of 3 μm to 15 μm, more preferably 5 μm to 10 μm, since the color conversion layer is relatively thick. Is within the range.

  Examples of the method for forming the planarizing layer include a spin coating method, a roll coating method, a bar coating method, a casting method, and an ink jet method.

(5) Transparent protective layer In this invention, the transparent protective layer 6 which has uneven | corrugated shape may be formed between the board | substrate 1 and the 1st inorganic insulating layer 2 so that it may illustrate in FIG. When the organic EL element barrier substrate of the present invention is used in an organic EL display device, a transparent electrode layer, a light emitting layer, and the like are formed on the second inorganic insulating layer, but the transparent protective layer has a concavo-convex shape. The uneven shape is also reflected in the layer and the like, and the light emitting area can be increased. Thereby, luminance can be increased.
Moreover, when said colored layer and color conversion layer are formed, a transparent protective layer is formed between a colored layer or a color conversion layer, and a 1st inorganic insulating layer.

  As a material for forming the transparent protective layer, it is preferable to use a transparent resin having a visible light transmittance of 50% or more. For example, a photocurable resin or a thermosetting resin having an acrylate-based or methacrylate-based reactive vinyl group is used. Can be mentioned. Examples of the transparent resin include polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester. Resins, maleic acid resins, polyamide resins and the like can be used.

The concavo-convex shape of the transparent protective layer is not particularly limited as long as the luminescent area can be increased and the luminescent layer can be formed so that there is no unevenness in thickness. Is preferred. This is because in addition to the effect of increasing the light emitting area, a light collecting effect can be obtained.
The lens shape may be, for example, a convex lens shape, a concave lens shape, or another lens shape. In the case of a convex lens shape, it may be a shape like a spherical plano-convex lens or a shape like a cylindrical plano-convex lens. In the case of a concave lens shape, it may be a shape like a spherical plano-concave lens or a shape like a cylindrical plano-concave lens.

  In addition, when the above-described colored layer or color conversion layer is formed, the transparent protective layer is preferably one in which irregularities, particularly lenses, are arranged for each colored pattern or each color conversion pattern. In this case, a convex lens shape is particularly preferable. When the barrier substrate for an organic EL element of the present invention is used in an organic EL display device, light emitted from the light emitting layer in all directions can be condensed into a corresponding colored pattern or color conversion pattern. This is because it is possible to improve the use efficiency and increase the luminance. Furthermore, since it can concentrate on a corresponding coloring pattern and color conversion pattern, color mixing can be prevented and color purity can be improved.

The thickness of the unevenness is appropriately adjusted in consideration of the size of each colored pattern or each color conversion pattern, the refractive index of the resin material used, and can be specifically set to about 1 μm to 20 μm. . This is because if the thickness of the unevenness is too large, thickness unevenness occurs in the light emitting layer and stable light emission may not be obtained.
The pitch of the unevenness is appropriately set in consideration of the size of each coloring pattern and each color conversion pattern, the refractive index of the resin material to be used, and the like. The distance is about 0.1 μm to 5 μm. If the pitch is too small, it is difficult to form irregularities, and if the pitch is too large, the effect of increasing the light emitting area may not be sufficiently obtained.

When the uneven shape is a lens shape, the height (center thickness) of the lens shape is appropriately adjusted in consideration of the size of each coloring pattern and each color conversion pattern, the refractive index of the resin material used, and the like. For example, it can set suitably so that the light omnidirectionally emitted from a light emitting layer may be condensed by the corresponding coloring pattern and color conversion pattern. The focal position is not particularly limited. Usually, the height of the lens shape is about 1 μm to 20 μm. This is because if the height of the lens shape is too large, the curvature becomes large, thickness unevenness occurs in the light emitting layer, and stable light emission may not be obtained.
The pitch of the lens shape is appropriately set in consideration of the size of each coloring pattern and each color conversion pattern, the refractive index of the resin material to be used, and the distance between the vertices of adjacent lens shapes is usually 0. It is about 1 μm to 5 μm. This is because if the pitch of the lens shape is too small, it is difficult to form the lens shape, and if the pitch of the lens shape is too large, the effect of providing the lens shape may not be sufficiently obtained.

  The transparent protective layer having such a lens shape is formed, for example, by preparing a lens-shaped mold, filling the mold with the resin material, pressurizing the mold in contact with the substrate, and curing the resin material. be able to. Alternatively, for example, a lens-shaped mold is prepared, and the mold is filled with the resin material and cured to create a transparent resin sheet having a lens shape, and the transparent resin sheet is directly on the substrate. Or a transparent protective layer can be formed by sticking through an adhesive. Furthermore, a transparent protective layer can be formed by applying the above resin material on a substrate, and then pressing and pressing a lens-shaped mold.

4). Substrate The substrate used in the present invention is preferably transparent in order to extract light from the substrate side when the organic EL display device is formed using the barrier substrate for organic EL elements of the present invention. Moreover, it is preferable that a board | substrate has solvent resistance and heat resistance, and is excellent in dimensional stability. This is because it can be made stable even when the first inorganic insulating layer, the second inorganic insulating layer, and the like are formed on the substrate.

  As the transparent substrate, for example, a glass substrate or a film or sheet formed of an organic material can be used.

  The glass substrate is not particularly limited as long as it has high transparency to visible light. For example, the glass substrate may be an unprocessed glass substrate or a processed glass substrate. As the glass substrate, both alkali glass and non-alkali glass can be used. However, when impurities are a problem, it is preferable to use non-alkali glass such as Pyrex (registered trademark) glass. The type of the processed glass substrate is appropriately selected according to the application of the barrier substrate for an organic EL element of the present invention. For example, a transparent glass substrate is subjected to a coating process or a step process is performed. And the like.

  The thickness of the glass substrate is preferably within a range of 20 μm to 2 mm. Especially, when using as a flexible board | substrate, it is preferable to exist in the range of 20 micrometers-200 micrometers, and when using as a rigid board | substrate, it is preferable to exist in the range of 200 micrometers-2 mm.

Examples of the organic material used for the transparent substrate include polyarylate resin, polycarbonate resin, crystallized polyethylene terephthalate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, UV curable methacrylic resin, polyether sulfone resin, and polyether ether. Examples include ketone resins, polyetherimide resins, polyphenylene sulfide resins, and polyimide resins.
Further, as the transparent substrate, for example, the above-described organic material, for example, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), poly (Meth) acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins such as various nylons, polyurethane resins, fluorine resins, acetal resins, cellulose resins, polyethers Two or more types can be used in combination with a sulfone resin or the like.

  When a transparent substrate is formed using the organic material as described above, the thickness of the substrate is preferably in the range of 10 μm to 500 μm, more preferably in the range of 50 to 400 μm, and particularly preferably in the range of 100 to 300 μm. . This is because if the thickness of the substrate is too thick, the impact resistance is inferior, the winding becomes difficult at the time of winding, and the barrier property may be deteriorated. Moreover, if the film thickness of the substrate is too thin, the mechanical suitability is poor and the barrier property may be lowered.

  In the present invention, it is preferable to clean and use the substrate. As the cleaning method, it is preferable to perform ultraviolet light irradiation treatment with oxygen, ozone, etc., plasma treatment, argon sputtering treatment, or the like. This is because moisture and oxygen are not adsorbed, and dark spots can be reduced and the life of the organic EL element can be extended.

5. Others In the present invention, by providing the second inorganic insulating layer on the first inorganic insulating layer, it is possible to obtain barrier properties against gas generated from water vapor, oxygen, a colored layer, and the like. As barrier property of the organic EL device barrier substrate of the present invention, the oxygen gas permeability ^1cc / m 2 / day / atm or less, and preferably less inter alia ^{0.5cc / m 2 / day / atm} . The water vapor transmission rate is preferably 1 g / m ² / day or less, particularly preferably 0.5 g / m ² / day or less. When the oxygen gas permeability and the water vapor permeability are in the above-described ranges, a high barrier property can be realized, and the barrier substrate for an organic EL element of the present invention can be used as a gas from oxygen, water vapor, a colored layer, or the like. This is because it can be suitably used for an organic EL element having a weak member.

  The oxygen gas permeability is a value measured using an oxygen gas permeability measuring apparatus (manufactured by MOCON, OX-TRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a humidity of 90% Rh. It is. The water vapor transmission rate is a value measured using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W 3/31: trade name) under the conditions of a measurement temperature of 37.8 ° C. and a humidity of 100% Rh. It is.

B. Next, a method for producing a barrier substrate for organic EL elements according to the present invention will be described.
The method for producing a barrier substrate for an organic EL device of the present invention includes a first inorganic insulating layer forming step of forming at least one vapor deposited film on a substrate, and ultrafine particles dispersed in a solvent on the first inorganic insulating layer. And a second inorganic insulating layer forming step of forming a film by applying and baking the ultrafine particle dispersion.

  FIG. 8 is a process diagram showing an example of a method for producing a barrier substrate for an organic EL element of the present invention. In the present invention, first, a vapor deposition film is formed on the substrate 1 by vapor deposition to form the first inorganic insulating layer 2 (first inorganic insulating layer forming step, FIG. 8A). Next, an ultrafine particle dispersion liquid 23 in which ultrafine particles are dispersed in a solvent is applied on the first inorganic insulating layer 2 and baked to form the second inorganic insulating layer 3 (second inorganic insulating layer forming step). FIG. 8 (b), (c)).

According to the present invention, even when defects such as pinholes are present in the first inorganic insulating layer, which is a deposited film, an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent is applied on the first inorganic insulating layer. Since the second inorganic insulating layer is formed, defects such as pinholes in the first inorganic insulating layer can be blocked by the ultrafine particles. Moreover, since defects such as pinholes in the first inorganic insulating layer can be effectively blocked by the leveling property by coating, a barrier substrate for an organic EL device having excellent barrier properties can be obtained.
Furthermore, when forming the second inorganic insulating layer, the ultrafine particles are densely sintered at a temperature much lower than a general temperature, and thus, for example, it is possible to perform baking at a temperature lower than the heat resistant temperature of the colored layer.
Hereinafter, each process of the manufacturing method of the barrier substrate for organic EL elements of this invention is demonstrated.

1. First Inorganic Insulating Layer Forming Step The first inorganic insulating layer forming step in the present invention is a step of forming at least one deposited film on the substrate.
The method for forming the first inorganic insulating layer is not particularly limited as long as it is a vapor deposition method, and may be either a PVD method (physical vapor deposition method) or a CVD method (chemical vapor deposition method). Of these, the PVD method is preferably used. The deposited film formed by the PVD method is more likely to have defects such as pinholes than the CVD method. However, in the present invention, defects such as pinholes can be blocked by the ultrafine particles in the second inorganic insulating layer. This is because the effects of the present invention are remarkably exhibited. In addition, the PVD method is advantageous in terms of cost compared with the CVD method.
As the PVD method, for example, a general method such as a sputtering method, a vacuum deposition method, or an ion plating method is used.

  In this step, a plurality of deposited films may be stacked to form the first inorganic insulating layer. This is because the barrier property can be enhanced by laminating a plurality of deposited films. In addition, about the lamination | stacking number of vapor deposition films, it is the same as that of what was described in the term of the 1st inorganic insulating layer of the said "A. Barrier substrate for organic EL elements".

At this time, it is preferable to stack the deposited film so that there is no pinhole. Specifically, it is preferable to form a lower vapor-deposited film on the substrate, polish the surface of the lower vapor-deposited film, and then form an upper vapor-deposited film thereon. For example, when a vapor deposition film 12a is formed on the substrate 1 as shown in FIG. 9A, and the foreign material 31 is present on the surface of the vapor deposition film 12a, the surface of the vapor deposition film 12 is used by using sandpaper 32 or the like. By polishing, the foreign material 31 can be removed as illustrated in FIG. Then, as illustrated in FIG. 9C, the barrier property of the portion where the foreign material 31 was present can be reinforced by further laminating the vapor deposition film 12b on the vapor deposition film 12a. Next, as illustrated in FIG. 9D, the barrier property can be obtained by forming the second inorganic insulating layer 3 on the first inorganic insulating layer 2 including the two deposited films 12a and 12b.
In addition, in order to stack the deposited film so that there is no pinhole, in addition to stacking the two deposited films as described above, a plurality of deposited films are further formed on the polished deposited film to form a multilayer structure. May be.

As a polishing method, for example, a method using a sandpaper or the like in which suitable abrasive grains are dispersed and adhered on a sheet, a chemical polishing method or a mechanical polishing method, or chemical mechanical polishing (CMP) using them in combination. Etc. can be used.
The chemical polishing method is performed by supplying an etching liquid as an abrasive to an abrasive member made of a foam such as cloth, non-woven fabric, or polyurethane resin.
The mechanical polishing method uses, for example, a cloth, a nonwoven fabric, or a foamed material such as polyurethane resin as an abrasive member, impregnated with a fine powder of colloidal silica or cerium oxide as an abrasive, or colloidal silica or cerium oxide as an abrasive. This is performed by supplying a dispersion in which is dispersed.

  In any of the above methods, the polishing is performed by rotating the target object, etc., relatively moving the target object and the polishing member, bringing the polishing member into contact with the vapor deposition film surface, and supplying an abrasive as necessary. However, it is preferable to carry out. Further, it is more preferable to polish until all the foreign matters are removed.

2. Second inorganic insulating layer forming step In the second inorganic insulating layer forming step of the present invention, an ultrafine particle dispersion liquid in which ultrafine particles are dispersed in a solvent is applied onto the first inorganic insulating layer and baked to form a film. It is a process to do.
This step can be divided into two modes depending on the type of ultrafine particles. In the first aspect, an ultrafine particle dispersion containing at least one ultrafine particle selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides is applied and baked to form a film. Is the case. The second embodiment is a case in which an ultrafine particle dispersion containing ultrafine metal particles is applied and fired to form a film, and oxidation and sintering are advanced during firing.
Hereinafter, the description will be made separately for each aspect.

(1) First Aspect In this aspect, an ultrafine particle dispersion in which at least one ultrafine particle selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides is dispersed in a solvent is applied. Baked to form a film. That is, the second inorganic insulating layer forming step of this aspect includes an ultrafine particle dispersion preparation step for preparing an ultrafine particle dispersion, a coating step for applying this ultrafine particle dispersion, and a coating film obtained in this coating step. And a baking step of baking. Hereinafter, each step will be described.

(I) Ultrafine particle dispersion preparation step The ultrafine particle dispersion used in this embodiment is a dispersion in which ultrafine particles are individually and uniformly dispersed, and is composed of an inorganic oxide, an inorganic nitride, and an inorganic oxynitride. It is prepared by dispersing at least one kind of ultrafine particles selected from the group consisting of in a solvent.
The ultrafine particles of the inorganic oxide, inorganic nitride, and inorganic oxynitride are the same as those described in the above section “A. Barrier substrate for organic EL element”, so the explanation here is as follows. Omitted.
Here, the average particle diameter of the ultrafine particles used in the ultrafine particle dispersion is a value measured by a laser method. The average particle diameter is generally used to indicate the particle size of the particles, and the laser method is to disperse the particles in a solvent and thin the scattered light obtained by applying a laser beam to the dispersion solvent. This is a method of measuring the average particle size, particle size distribution, etc. by calculation. The average particle size is a value measured using a particle size analyzer Microtrac UPA Model-9230 manufactured by Leeds & Northrup as a particle size measuring device by a laser method.

  The method for producing the ultrafine particles is not particularly limited, and for example, a gas evaporation method, a wet reduction method, a thermal reduction method by spraying an organometallic compound in a high temperature atmosphere, or the like is used.

  In the gas evaporation method, the metal or silicon is evaporated in a gas atmosphere and in the gas phase in which the solvent vapor coexists, and the evaporated metal or silicon is brought into contact with a reaction gas (oxygen, nitrogen, etc.) to make inorganic. In this method, oxides, inorganic nitrides, inorganic oxynitrides and the like are formed, condensed into uniform ultrafine particles, and dispersed in a solvent to obtain a dispersion. In this gas evaporation method, ultrafine particles having a uniform particle size can be obtained. In order to prepare an ultrafine particle dispersion using ultrafine particles obtained by a gas evaporation method as a raw material, substitution may be performed with a solvent used for the ultrafine particle dispersion. Further, a dispersant may be added to increase the dispersion stability of the ultrafine particles. As a result, the ultrafine particles are dispersed individually and uniformly, and a fluid state is maintained.

For example, indium oxide ultrafine particles can also be produced as follows.
An aqueous solution of an indium salt such as indium chloride, indium nitrate, indium sulfate, indium acetate, or indium oxalate is maintained at a predetermined temperature, and the aqueous solution and an alkaline aqueous solution such as an ammonium compound or an alkali metal compound are maintained at the predetermined temperature. Mix and perform a coprecipitation reaction at a predetermined pH for a predetermined time to precipitate a hydroxide. Thereafter, if desired, the precipitate is repeatedly washed with ion-exchanged water, and when the electrical conductivity of the supernatant falls below a predetermined value, the precipitated indium coprecipitated hydroxide is filtered off. Next, this coprecipitated hydroxide cake is baked in the atmosphere at a temperature of 350 to 800 ° C., preferably 500 to 800 ° C. to produce indium oxide ultrafine particles. Since the particles after firing are aggregated, it is preferable to pulverize and loosen the aggregated particles.
In the coprecipitation reaction, the reaction temperature is generally 25 to 70 ° C., the reaction time depends on the reaction temperature, but is generally 30 to 120 minutes, and the pH at the end of the reaction is 5 to 11.

The solvent used in the ultrafine particle dispersion is appropriately selected depending on the ultrafine particles to be used. For example, methanol, ethanol, propanol, isopropyl alcohol, butanol, hexanol, heptanol, octanol, decanol, cyclohexanol, terpineol Alcohols such as ethylene glycol and propylene glycol; ketones such as acetone, methyl ethyl ketone and diethyl ketone; esters such as ethyl acetate, butyl acetate and benzyl acetate; ether alcohols such as methoxyethanol and ethoxyethanol; Ethers such as dioxane and tetrahydrofuran; acid amides such as N, N-dimethylformamide; benzene, toluene, xylene, trimethylbenzene, dodecylben Aromatic hydrocarbons such as hexane; long-chain alkanes such as hexane, heptane, octane, nonane, decane, undecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, eicosane, trimethylpentane; cyclohexane, cycloheptane, And cyclic alkanes such as cyclooctane; Furthermore, water can also be used.
These may be used alone or as a mixed solvent. For example, it may be a mineral spirit that is a mixture of long-chain alkanes.

  For example, as a solvent used when preparing an ultrafine particle dispersion using indium oxide ultrafine particles obtained by the above-mentioned method, alcohols such as methanol, ethanol, isopropanol, butanol; acetone, methyl ethyl ketone, methyl isobutyl ketone, Ketones such as cyclohexanone, isophorone and 4-hydroxy-4methyl-2pentanone; hydrocarbons such as toluene, xylene, hexane and cyclohexane; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; And alkyl ethers such as carbitol and butyl carbitol; sulfoxides such as dimethyl sulfoxide; and the like. These solvents can be used alone or in combination of two or more.

Furthermore, it is preferable that the solvent evaporates during drying and baking performed after applying an ultrafine particle dispersion described later. In particular, the boiling point of the solvent is preferably 120 ° C or higher, more preferably 150 ° C or higher, further preferably 170 ° C or higher, and most preferably 190 ° C or higher. This is because if the boiling point of the solvent is lower than the above range, for example, it is easy to evaporate at the time of drying, so that the ultrafine particles are likely to aggregate and a uniform film may not be obtained. On the other hand, the upper limit of the boiling point of the solvent is about 350 ° C. from the upper limit of the firing temperature.
Among these solvents, terpineol, decane, dodecane, tridecane, tetradecane, dodecylbenzene, mineral spirit, and the like are preferably used.

  What is necessary is just to select the usage-amount of the said solvent suitably according to the ultrafine particle to be used so that it can apply | coat easily and a desired film thickness can be obtained. Specifically, the concentration of the ultrafine particles in the ultrafine particle dispersion is preferably in the range of 1 to 50 wt%, more preferably in the range of 10 to 40 wt%. This is because if the concentration of the ultrafine particles is less than the above range, it is difficult to close defects such as pinholes in the first inorganic insulating layer, and a desired film thickness may not be obtained. On the other hand, when the concentration of the ultrafine particles exceeds the above range, the viscosity of the ultrafine particle dispersion is increased and the fluidity is lowered, which also makes it difficult to close defects such as pinholes in the first inorganic insulating layer, Furthermore, the flatness of the surface of the second inorganic insulating layer may be impaired.

  Further, the viscosity of the ultrafine particle dispersion is preferably 100 cP or less at 20 ° C., and more preferably 10 cP or less. This is because if the viscosity is in the above range, defects such as pinholes in the first inorganic insulating layer can be closed and a flat film can be formed.

(Ii) Applying step In this embodiment, next, the ultrafine particle dispersion is applied to form a coating film.
The method for applying the ultrafine particle dispersion may be any method that can block defects such as pinholes in the first inorganic insulating layer and can be applied to a uniform thickness. For example, spin coating, spray coating, dip coating, etc. Examples thereof include a coating method, a roll coating method, an ink jet method, and a screen printing method.

  After the ultrafine particle dispersion is applied to form a coating film, the coating film may be dried to remove the solvent. The drying temperature is appropriately selected according to the type of solvent, but is usually about 50 ° C to 100 ° C.

(Iii) Firing step In the present embodiment, the coating film is then fired.
The firing temperature is appropriately selected depending on the type of ultrafine particles to be used, but is preferably about 150 ° C to 350 ° C, more preferably in the range of 150 ° C to 250 ° C, and still more preferably. It is in the range of 150 ° C to 220 ° C. This is because if the firing temperature is too low, the ultrafine particles may not be sufficiently sintered, and if the firing temperature is too high, the substrate or the colored layer may be thermally damaged. The temperature required to sinter the inorganic oxide constituting the ultrafine particles alone is generally about 400 to 700 ° C., but in the present invention, it is extremely low as 150 ° C. to 350 ° C. due to the size effect of the ultrafine particles. It can be fired at temperature.
Also, the firing time is appropriately selected depending on the type of ultrafine particles used and the like, but is usually about 10 minutes to 1 hour, preferably 15 minutes to 30 minutes.

  In this step, baking may be performed in an oxidizing atmosphere, or baking may be performed in an atmosphere in which ultrafine particles are not oxidized, and then baking may be performed in an oxidizing atmosphere. That is, it may be fired by a one-stage process or may be fired by a two-stage process. This is because in the firing by the two-stage process, it can be avoided that only the surface of the ultrafine particles is further oxidized and the sintering becomes insufficient. In addition, since baking is performed in two stages, a denser film can be formed by low-temperature baking.

Examples of the atmosphere in which the ultrafine particles are not oxidized include a vacuum atmosphere, an inert gas atmosphere, and a reducing atmosphere.
Examples of the inert gas atmosphere include inert atmospheres such as rare gas, carbon dioxide, and nitrogen.
Examples of the reducing atmosphere include hydrogen, carbon monoxide, lower alcohol, and the like. Examples of the lower alcohol include lower alcohols having 1 to 6 carbon atoms such as methanol, ethanol, propanol, butanol, hexanol and the like.
The vacuum atmosphere is, for example, an inert gas such as a rare gas, carbon dioxide, or nitrogen; an oxidizing gas such as oxygen or water vapor; a reducing gas such as hydrogen, carbon monoxide, or a lower alcohol; or the above inert gas and an oxidizing gas. Or a mixed gas with a reducing gas or a reducing gas. When an oxidizing gas is introduced in a vacuum atmosphere, there is an effect that only the organic compound (solvent or dispersant) adhering to the ultrafine particles is burned without oxidizing the ultrafine particles. The vacuum state may be simply drawn by a pump, or once pumped, an inert gas, a reducing gas, or an oxidizing gas may be introduced. Firing in a vacuum atmosphere can usually be performed at about 10 ⁻⁵ to 10 ³ Pa.

  The oxidizing atmosphere may contain oxygen, water vapor, oxygen-containing gas (for example, air), water vapor-containing gas, and the like.

  In this embodiment, the coating film may be dried after firing in an atmosphere in which the ultrafine particles are not oxidized and before firing in an oxidizing atmosphere. This is because the solvent and the dispersant can be removed. The removal of the solvent and the dispersant may be performed at the time of firing.

Further, after firing in an oxidizing atmosphere, firing may be performed in a reducing atmosphere.
Furthermore, ultraviolet irradiation may be performed during firing. More effective in terms of time reduction and low temperature. In the firing, so-called plasma sintering using atmospheric pressure plasma or the like can also be used.

(2) Second Aspect In this aspect, an ultrafine particle dispersion containing ultrafine metal particles is applied and baked to form a film. That is, the second inorganic insulating layer forming step of this aspect includes an ultrafine particle dispersion preparation step for preparing an ultrafine particle dispersion, a coating step for applying this ultrafine particle dispersion, and a coating film obtained in this coating step. And a baking step of baking.
In addition, since it is the same as that of what was described in the said 1st aspect about the application | coating process and a baking process, description here is abbreviate | omitted. Hereinafter, the ultrafine particle dispersion preparation process will be described.

(I) Ultrafine particle dispersion preparation step The ultrafine particle dispersion used in this embodiment is prepared by dispersing ultrafine particles of metal in a solvent in which ultrafine particles are dispersed individually and uniformly. .
Examples of the ultrafine metal particles used in this embodiment include In, Al, Ti, Ta, Zn, Sn, Y, Ge, Pb, Zr, alkali metals (Li, Na, K), alkaline earth metals (Mg, Examples thereof include ultrafine particles such as Ca, Sr, Ba). Among these, at least one kind of ultrafine particles selected from the group consisting of In (indium), alkali metals, and alkaline earth metals is preferably used. This is because indium, alkali metal, and alkaline earth metal are highly oxidizable, so that oxidation is promoted even by firing at a relatively low temperature.

  The method for producing the ultrafine particles is not particularly limited, and for example, a gas evaporation method, a wet reduction method, a thermal reduction method by spraying an organometallic compound in a high temperature atmosphere, or the like is used. The surface of the obtained ultrafine particles is preferably in a metal state, but may be partially oxidized.

The gas evaporation method is a method in which a metal is evaporated in a gas atmosphere in a gas phase in which a solvent vapor coexists, and the evaporated metal is condensed into uniform ultrafine particles and dispersed in a solvent to obtain a dispersion. is there. In this gas evaporation method, ultrafine metal particles having a uniform particle size can be obtained. In order to prepare an ultrafine particle dispersion using the ultrafine metal particles obtained by the gas evaporation method as a raw material, substitution may be performed with a solvent used for the ultrafine particle dispersion. Further, a dispersant may be added to increase the dispersion stability of the ultrafine particles. As a result, the ultrafine particles are dispersed individually and uniformly, and a fluid state is maintained.
Note that a method for producing ultrafine particles by the gas evaporation method is detailed in Japanese Patent No. 2651537 and Japanese Patent Application Laid-Open No. 2005-183054.

Further, as a method for producing ultrafine particles, a chemical reduction method such as a liquid phase reduction method can be used. In this case, a reducing raw material that is a metal-containing organic compound can be used as a raw material for producing ultrafine particles.
The chemical reduction method is a method of preparing an ultrafine particle dispersion by a chemical reaction using a reducing agent. In the case of the fine particles produced by this chemical reduction method, the particle size can be arbitrarily adjusted. In the chemical reduction method, first, the raw material is thermally decomposed at a predetermined temperature in a state where a dispersant is added to the raw material, or ultrafine metal particles are formed using a reducing agent such as hydrogen or sodium borohydride. generate. Next, almost all of the generated ultrafine metal particles are recovered in an independently dispersed state. By replacing the obtained dispersion with a solvent used for the ultrafine particle dispersion, a desired ultrafine particle dispersion can be obtained. The obtained ultrafine particle dispersion maintains a stable dispersion state even if it is concentrated by heating in vacuum.
Note that a method for producing ultrafine particles by a chemical reduction method is detailed in JP-A-2005-81501.

  The solvent used in the ultrafine particle dispersion, the concentration and viscosity of the ultrafine particle dispersion, and the like are the same as those described in the first aspect, and thus the description thereof is omitted here.

C. Organic EL Display Device Next, the organic EL display device of the present invention will be described.
The organic EL display device of the present invention includes the above-described barrier substrate for organic EL elements, the transparent electrode layer formed on the second inorganic insulating layer of the barrier substrate for organic EL elements, and the transparent electrode layer. The organic EL layer is formed and includes at least a light emitting layer, and a back electrode layer formed on the organic EL layer.

  FIG. 10 shows an example of the organic EL display device of the present invention. As shown in FIG. 10, the organic EL display device 50 of the present invention was formed on the organic EL element barrier substrate 10 and the second inorganic insulating layer 53 of the organic EL element barrier substrate 10 described above. It has a transparent electrode layer 54, an organic EL layer 55 formed in a pattern on the transparent electrode layer 54, and a back electrode layer 56 formed on the organic EL layer 55. An insulating layer 57 is formed on the transparent electrode layer 54 and between the patterned organic EL layers 55. The insulating layer 57 is a layer provided to prevent the transparent electrode layer 54 and the back electrode layer 56 from contacting each other. Further, a partition wall 58 is formed on the insulating layer 57. A portion where the organic EL layer 55 is formed is a display region. The barrier substrate 10 for organic EL elements is obtained by sequentially laminating a first inorganic insulating layer 52 and a second inorganic insulating layer 53 on a substrate 51.

According to the present invention, since the barrier substrate for an organic EL element described above is used, it is possible to suppress the occurrence of defects such as dark spots and to provide an organic EL display device capable of displaying a good image. Further, in the barrier substrate for an organic EL element, the barrier property can be obtained by laminating the first inorganic insulating layer and the second inorganic insulating layer, so that a thick transparent barrier is formed by a sputtering method or a vacuum evaporation method as in the past. There is no need to provide a layer, and the cost can be reduced.
Hereinafter, each configuration of such an organic EL display device will be described.

1. Organic EL Layer The organic EL layer used in the present invention is composed of one or more organic layers including at least a light emitting layer. That is, the organic EL layer is a layer including at least a light emitting layer, and the layer configuration is a layer having one or more organic layers. Usually, when an organic EL layer is formed by a wet method by coating, it is often difficult to stack a large number of layers in relation to a solvent, so that it is often formed of one or two organic layers. However, it is possible to further increase the number of layers by devising an organic material so that the solubility in a solvent is different or by combining a vacuum deposition method.

Examples of the organic layer formed in the organic EL layer other than the light emitting layer include charge injection layers such as a hole injection layer and an electron injection layer. Furthermore, examples of the other organic layers include a charge transport layer such as a hole transport layer that transports holes to the light-emitting layer and an electron transport layer that transports electrons to the light-emitting layer. In many cases, it is formed integrally with the charge injection layer by imparting a charge transporting function. In addition, as an organic layer formed in the organic EL layer, it prevents holes or electrons from penetrating like a carrier block layer and further prevents diffusion of excitons and confines excitons in the light emitting layer. And a layer for increasing the recombination efficiency.
Hereinafter, each structure of such an organic EL layer will be described.

(1) Light emitting layer The light emitting layer used in the present invention has a function of emitting light by providing a recombination field of electrons and holes. As the material for forming the light emitting layer, a dye-based light-emitting material, a metal complex-based light-emitting material, or a polymer-based light-emitting material can be generally used.

  Examples of dye-based light emitting materials include cyclopentadiene derivatives, tetraphenylbutadiene derivatives, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, silole derivatives, thiophene ring compounds, pyridine rings Examples thereof include compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, coumarin derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

Metal complex light emitting materials include aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazole zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin zinc complex, europium complex, iridium metal complex, platinum metal complex, etc. The metal has Al, Zn, Be, Ir, Pt, etc., or a rare earth metal such as Tb, Eu, Dy, etc., and the ligand has an oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure, etc. A metal complex etc. can be mentioned. Specifically, tris (8-quinolinol) aluminum complex (Alq ₃ ) can be used.

  Furthermore, as the polymer light emitting material, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyvinylcarbazole, polyfluorenone derivatives, polyfluorene derivatives, polyquinoxaline derivatives, polydialkylfluorene derivatives, And copolymers thereof. Moreover, what polymerized the said pigment-type luminescent material and metal complex type | system | group luminescent material is also mentioned.

  Among the above, the light emitting material used in the present invention is preferably a metal complex light emitting material or a polymer light emitting material, and more preferably a polymer light emitting material. Of the polymer light emitting materials, a conductive polymer having a π-conjugated structure is preferable. Examples of the conductive polymer having such a π-conjugated structure include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorenone derivatives, polyfluorene derivatives, polyquinoxaline derivatives as described above. , Polydialkylfluorene derivatives, and copolymers thereof.

  The thickness of the light emitting layer is not particularly limited as long as it can provide a function of emitting light by providing a recombination field between electrons and holes, and can be, for example, about 1 nm to 200 nm. .

  Further, a dopant that emits fluorescence or phosphorescence may be added to the light emitting layer for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such dopants include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazoline derivatives, decacyclene, phenoxazone, quinoxaline derivatives, carbazole derivatives, fluorene derivatives, and the like. Can be mentioned.

  The method for forming the light emitting layer is not particularly limited as long as it is a method capable of high-definition patterning. For example, vapor deposition method, printing method, inkjet method, spin coating method, casting method, dipping method, bar coating method, blade coating method, roll coating method, gravure coating method, flexographic printing method, spray coating method, and self-assembly method (Alternate adsorption method, self-assembled monolayer method) and the like. Among these, it is preferable to use a vapor deposition method, a spin coating method, and an ink jet method. Further, when the light emitting layer is patterned, it may be applied separately by a masking method for pixels having different light emission colors, or a partition may be formed between the light emitting layers. As a material for forming such a partition, a photocurable resin such as a photosensitive polyimide resin or an acrylic resin, a thermosetting resin, an inorganic material, or the like can be used. Furthermore, you may perform the process which changes the surface energy (wetting property) of the material which forms these partition walls.

(2) Charge injection / transport layer In the present invention, a charge injection / transport layer may be formed between the transparent electrode layer or the back electrode layer and the light emitting layer. The charge injecting and transporting layer here has a function of stably transporting charges from the transparent electrode layer or the back electrode layer to the light emitting layer, and the charge injecting and transporting layer is used as the transparent electrode layer or the back surface. By providing between the electrode layer and the light emitting layer, the injection of charges into the light emitting layer is stabilized, and the light emission efficiency can be increased.

  Examples of the charge injection transport layer include a hole injection transport layer that transports holes injected from the anode into the light emitting layer, and an electron injection transport layer that transports electrons injected from the cathode into the light emitting layer. Hereinafter, the hole injection / transport layer and the electron injection / transport layer will be described.

(I) Hole Injecting and Transporting Layer The hole injecting and transporting layer used in the present invention is either a hole injecting layer for injecting holes into the light emitting layer or a hole transporting layer for transporting holes. The hole injection layer and the hole transport layer may be laminated, or a single layer having both the hole injection function and the hole transport function may be used.

  The material used for the hole injecting and transporting layer is not particularly limited as long as it can stably transport holes injected from the anode into the light emitting layer. In addition to the exemplified compounds, phenylamine, starburst amine, phthalocyanine, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide and other oxides, amorphous carbon, polyaniline, polythiophene, polyphenylene vinylene derivatives, etc. may be used. it can. Specifically, bis (N- (1-naphthyl-N-phenyl) benzidine (α-NPD), 4,4,4-tris (3-methylphenylphenylamino) triphenylamine (MTDATA), poly 3, 4-ethylenedioxythiophene-polystyrene sulfonic acid (PEDOT-PSS), polyvinyl carbazole (PVCz), etc. are mentioned.

  The thickness of the hole injecting and transporting layer is not particularly limited as long as the hole injecting holes from the anode and transporting the holes to the light emitting layer is sufficiently exhibited. It is preferable to be in the range of 5 nm to 1000 nm, especially in the range of 10 nm to 500 nm.

(Ii) Electron Injection / Transport Layer The electron injection / transport layer used in the present invention may be either an electron injection layer for injecting electrons into the light emitting layer or an electron transport layer for transporting electrons. A layer and an electron transport layer may be laminated, or a single layer having both an electron injection function and an electron transport function may be used.

  The material used for the electron injection layer is not particularly limited as long as the material can stabilize the injection of electrons into the light emitting layer. In addition to the compounds exemplified as the light emitting material of the light emitting layer, Aluminum lithium alloy, lithium fluoride, strontium, magnesium oxide, magnesium fluoride, strontium fluoride, calcium fluoride, barium fluoride, aluminum oxide, strontium oxide, calcium, polymethyl methacrylate, sodium polystyrene sulfonate, lithium, cesium, Alkali metals, alkali metal halides, alkali metal organic complexes, and the like, such as cesium fluoride, can be used.

  In addition, the thickness of the electron injection layer is not particularly limited as long as the electron injection function is sufficiently exerted.

On the other hand, the material used for the electron transport layer is not particularly limited as long as it is a material capable of transporting electrons injected from the first inorganic insulating layer and the second inorganic insulating layer or the back electrode layer into the light emitting layer. For example, bathocuproin, bathophenanthroline, phenanthroline derivative, triazole derivative, oxadiazole derivative, or tris (8-quinolinol) aluminum complex (Alq ₃ ) can be used.

  Furthermore, as an electron injecting and transporting layer composed of a single layer having both an electron injecting function and an electron transporting function, a metal doped layer in which an alkali metal or an alkaline earth metal is doped on an electron transporting organic material is formed. This can be used as an electron injecting and transporting layer. Examples of the electron-transporting organic material include bathocuproin, bathophenanthroline, and phenanthroline derivatives. Examples of the metal to be doped include Li, Cs, Ba, and Sr.

2. Transparent electrode layer and back electrode layer The transparent electrode layer and back electrode layer used in the present invention are electrodes having opposite charges.
The transparent electrode layer is generally composed of a metal oxide thin film having transparency and conductivity. Examples of such metal oxides include indium tin oxide (ITO), indium oxide, zinc oxide, and tin oxide.
Moreover, a metal is generally used as the back electrode layer. Specifically, magnesium alloy (MgAg etc.), aluminum alloy (AlLi, AlCa, AlMg etc.), aluminum, alkaline earth metal (Ca etc.), alkali metal (K, Li etc.), etc. are mentioned.

  A transparent electrode layer and a back electrode layer can be formed using the formation method of a general electrode layer, for example, sputtering method, a vacuum evaporation method, etc. are mentioned.

3. Insulating layer In the present invention, an insulating layer may be formed to insulate the transparent electrode layer from the back electrode layer. This insulating layer is formed in a pattern as a non-display area.
Examples of the material for forming the insulating layer include a photocurable resin such as an ultraviolet curable resin and a thermosetting resin. Such an insulating layer can be formed using a resin composition containing the above resin. As a patterning method, a general method such as a photolithography method or a printing method can be used.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be specifically described using examples and comparative examples.
[Example]
(Formation of black matrix)
As a transparent substrate, soda glass (Sn face polished product manufactured by Central Glass Co., Ltd.) having a size of 150 mm × 150 mm and a thickness of 0.7 mm was prepared. After cleaning this transparent substrate according to a conventional method, a thin film (thickness 0.2 μm) of oxynitride composite chromium is formed on the entire surface of one side of the transparent substrate by sputtering, and a photosensitive resist is applied onto the composite chromium thin film. Then, mask exposure, development, and etching of the composite chromium thin film were performed to form a black matrix having 84 μm × 284 μm rectangular openings in a matrix at a pitch of 100 μm.

(Formation of colored layer)
Three types of photosensitive coatings for colored layers of red, green, and blue were prepared. That is, the photosensitive coating for the red colored layer was obtained by dispersing a condensed azo pigment (manufactured by Ciba Specialty Chemicals Co., Ltd., chromophthal red BRN) in a binder resin. The photosensitive paint for the green colored layer was obtained by dispersing a phthalocyanine green pigment (manufactured by Toyo Ink Manufacturing Co., Ltd., Lionol Green 2Y-301) in a binder resin. The photosensitive paint for the blue colored layer was obtained by dispersing an anthraquinone pigment (manufactured by Ciba Specialty Chemicals, Chromophthal Blue A3R) in a binder resin. As the binder resin, an acrylic UV curable resin composition (acrylic UV curable resin 20%, acrylic UV curable resin monomer 20%, additive 5%, propylene glycol monomethyl ether acetate (PGMEA) 55%) is used. It was. Each colorant was blended at a ratio of 1 part (all parts are based on mass) to 10 parts of the acrylic UV curable resin composition, and sufficiently mixed and dispersed.
A colored layer of each color was formed using the above three types of photosensitive coatings for colored layers. That is, the green colored layer photosensitive coating material was applied to the entire surface of the transparent substrate on which the black matrix was formed by a spin coating method, and prebaked (80 ° C., 30 minutes). Then, it exposed using the predetermined photomask for colored layers. Next, development is performed with a developer (0.05% KOH aqueous solution), followed by post-baking (100 ° C., 30 minutes), and a strip-shaped (90 μm wide) green color at a predetermined position with respect to the black matrix pattern. A colored layer (thickness 1.5 μm) was formed. Similarly, a strip-like (90 μm wide) red colored layer (thickness: 1.5 μm) was formed at a predetermined position with respect to the black matrix pattern using a photosensitive paint of a red colored layer. Further, a strip-like (90 μm wide) blue colored layer (thickness: 1.5 μm) was formed at a predetermined position with respect to the black matrix pattern using a photosensitive material for the blue colored layer.

(Formation of planarization layer)
A flattening layer coating solution obtained by diluting norbornene-based resin (ARTON manufactured by JSR Corporation) having an average molecular weight of about 100,000 with toluene is applied onto the colored layer by spin coating, and then baked ( 100 ° C., 30 minutes). Thereby, a planarization layer (thickness 7 μm) was formed so as to cover the colored layer. The planarization layer was a transparent and uniform film.

(Formation of the first inorganic insulating layer)
Next, a silicon oxide film was formed twice on the planarizing layer by sputtering under the following conditions to form a first inorganic insulating layer having a thickness of 200 nm. During each film forming process, lapping polishing was performed while spraying pure water using a polishing tape of about # 800. Subsequently, mirror polishing (polishing) was performed on the lower silicon oxide film while spraying an alumina fine particle abrasive using a rotary polishing machine (manufactured by Speed Fam).
Film formation conditions of silicon oxide film / RF sputtering power: 50 W / cm ² , frequency 13.56 MHz
・ Deposition rate: 10 nm / min ・ Deposition pressure: 0.5 Pa
SiO ₂ target: 4N (density 2.25 g / cm ³ )

(Formation of second inorganic insulating layer)
When producing In particles by gas evaporation using high frequency induction heating under the condition of helium gas pressure of 0.5 torr, the production of In particles is 20: 1 (capacity ratio) of α-terpineol and dodecylamine. Steam was collected, cooled and collected to collect In fine particles, and a dispersion containing 20% by weight of In fine particles having an average particle diameter of 10 nm dispersed in an α-terpineol solvent in an independent state was prepared. Five volumes of acetone were added to 1 volume of this dispersion (colloidal solution) and stirred. The fine particles in the dispersion liquid settled by the action of polar acetone. After standing for 2 hours, the supernatant was removed, the same amount of acetone was added again and stirred, and after standing for 2 hours, the supernatant was removed. From this sediment, the residual solvent was completely removed, In fine particles having an average particle diameter of 10 nm were produced, and confirmed to be non-oxidized fine particles by X-ray diffraction. The fine particles were dispersed in tetradecane at a concentration of 10 wt% to obtain an ultrafine particle dispersion.
This ultrafine particle dispersion was applied onto the first inorganic insulating layer by spin coating. Then, the coating film was baked under conditions of 230 ° C. and 10 minutes under a reduced pressure of 1 × 10 ⁻³ Pa. Next, firing was performed at 230 ° C. for 60 minutes in an oxidizing atmosphere (atmosphere). The film thickness at this time was 200 nm. As a result of observing a pinhole having a size of 1 μm or more in a region of 5 cm ² with an optical micrograph (magnification = 1000 times) in the second inorganic insulating layer thus formed, it was not detected.

(Formation of transparent electrode layer)
Next, an indium tin oxide (ITO) film having a film thickness of 150 nm is formed on the second inorganic insulating layer by ion plating, a photosensitive resist is applied on the ITO film, mask exposure, development, Etching was performed to form a transparent electrode layer. This transparent electrode layer was a strip-like pattern having a width of 60 μm formed on the second inorganic insulating layer so as to run on the colored layer from the transparent substrate, and was located on the colored layer.

(Formation of auxiliary electrode)
Next, a chromium thin film (thickness 0.2 μm) is formed by sputtering on the entire surface of the second inorganic insulating layer so as to cover the transparent electrode layer, a photosensitive resist is applied on the chromium thin film, and mask exposure is performed. Then, development and etching of the chromium thin film were performed to form auxiliary electrodes. This auxiliary electrode is a belt-like pattern formed on the transparent electrode layer so as to run on the colored layer from the transparent substrate, and is located on the black matrix with a width of 14 μm on the colored layer, In the terminal portion, the width is 60 μm.

(Formation of insulating layer and partition wall)
A second inorganic insulating layer is used so as to cover the transparent electrode layer by spin coating using a coating solution for an insulating layer obtained by diluting norbornene-based resin (ARTON manufactured by JSR Corporation) having an average molecular weight of about 100,000 with toluene. After coating on top, baking (100 ° C., 30 minutes) was performed to form an insulating film (thickness 1 μm). Next, a photosensitive resist was applied on the insulating film, mask exposure, development, and etching of the insulating film were performed to form an insulating layer. This insulating layer was a strip-like pattern (width 20 μm) intersecting the transparent electrode layer at a right angle, and was located on the black matrix.
Next, a partition wall coating (photograph ZPN1100 manufactured by Nippon Zeon Co., Ltd.) was applied over the entire surface by spin coating so as to cover the insulating layer, and prebaked (70 ° C., 30 minutes). Then, it exposed using the photomask for predetermined partition parts, developed with the developing solution (Nippon Zeon Co., Ltd. product ZTMA-100), and then post-baked (100 degreeC, 30 minutes). Thereby, the partition part was formed on the insulating layer. The partition wall had a shape with a height of 10 μm, a lower portion (insulating layer side) width of 15 μm, and an upper portion width of 26 μm.

(Formation of organic EL layer)
Next, an organic EL layer composed of a hole injection layer, a light emitting layer, and an electron injection layer was formed by a vacuum deposition method using the partition walls as a mask. That is, first, 4,4 ′, 4 ″ tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine is 200 nm thick through a mask having an opening corresponding to the image display region. By vapor-depositing to 4 nm, and then depositing 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl to a thickness of 20 nm, the partition wall becomes a mask pattern, The material passed only between the partition walls, and a hole injection layer was formed on the transparent electrode layer.
Next, in the same manner as described above, a light emitting layer was formed by vapor-depositing a light emitting material to 300 nm using the partition walls as a mask.
Further, tris (8-quinolinol) aluminum was vapor-deposited to a thickness of 20 nm to form an electron injection layer.
The organic EL layer (thickness: 540 nm) formed in this manner is present between the partition walls as a strip pattern having a width of about 280 μm (partly on the insulating layer), and is formed on the upper surface of the partition walls. A dummy organic EL layer was formed in the same layer configuration. A 460 nm gap is formed between the surface of the organic EL layer and the lower surface of the insulating layer formed as described above (interface with the second inorganic insulating layer). The organic EL layer was not in direct contact.

(Formation of back electrode layer)
Next, magnesium and silver are simultaneously vapor-deposited in a region where the partition walls are formed through a mask having a predetermined opening wider than the image display region by a vacuum vapor deposition method (magnesium vapor deposition rate = 1.3 to The film was formed at 1.4 nm / second, silver deposition rate = 0.1 nm / second). Thereby, the partition wall was used as a mask, and a back electrode layer (thickness 200 nm) made of a magnesium / silver mixture was formed on the organic EL layer. This back electrode layer was present on the organic EL layer as a band-like pattern having a width of 280 μm, and a dummy back electrode layer was also formed on the upper surface of the partition wall.
Thus, an organic EL display device was produced. The transparent electrode layer and the back electrode layer intersect each other by applying a voltage of DC 8.5 V to the transparent electrode layer and the back electrode layer of this organic EL display device at a constant current density of 10 mA / cm ² and driving them continuously. The light emitting layer at a desired site was caused to emit light. After the color correction in the colored layer, the result of measuring the defect occurrence rate due to the dark area for the light emission of each color observed on the opposite surface side of the transparent base material is 0.5%, and the high-quality three-primary color image It was possible to display.

[Comparative example]
The planarization layer was formed in the same manner as in the example. Next, a silicon oxide film was formed twice on the planarizing layer by a sputtering method under the same conditions as the first inorganic insulating layer of the example, thereby forming an inorganic insulating layer (thickness 300 nm). Between each film-forming process, it grind | polished like the Example. The result of counting the number of pinholes having a size of 1 μm or more in a 5 cm ² region with an optical micrograph (magnification = 1000 times) in the thus formed inorganic insulating layer was the same as that of the example.
Thereafter, an organic EL display device was produced in the same manner as in the example. With respect to this organic EL display device, the voltage was applied in the same manner as in the example to observe the image display quality, and the defect occurrence rate due to the dark area was measured. As a result, it was as high as 10%. It was possible.

It is a schematic sectional drawing which shows an example of the barrier property board | substrate for organic EL elements of this invention. It is a SEM photograph of the film | membrane formed with the ultrafine particle. It is a SEM photograph of a vapor deposition film. It is a schematic sectional drawing which shows the other example of the barrier property board | substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the barrier property board | substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the barrier property board | substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the barrier property board | substrate for organic EL elements of this invention. It is process drawing which shows an example of the manufacturing method of the barrier property board | substrate for organic EL elements of this invention. It is process drawing which shows the other example of the manufacturing method of the barrier property board | substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows an example of the organic electroluminescent display apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 ... Board | substrate 2,52 ... 1st inorganic insulating layer 3,53 ... 2nd inorganic insulating layer 4 ... Colored layer 5 ... Color conversion layer 6 ... Transparent protective layer 10 ... Barrier board | substrate 12a, 12b for organic EL elements ... Deposition film 23 ... Ultrafine particle dispersion 50 ... Organic EL display device 54 ... Transparent electrode layer 55 ... Organic EL layer 56 ... Back electrode layer

Claims (14)

  A substrate, a first inorganic insulating layer that is a vapor-deposited film formed on the substrate, and a second inorganic insulating layer that is a film formed on the first inorganic insulating layer and formed of ultrafine particles. A barrier substrate for an organic electroluminescence device characterized by the above.   The said 1st inorganic insulating layer consists of a some vapor deposition film, The barrier property board | substrate for organic electroluminescent elements of Claim 1 characterized by the above-mentioned.   3. The barrier substrate for an organic electroluminescent element according to claim 1, wherein the sintering temperature of the ultrafine particles is 350 ° C. or lower.   The ultrafine particles are at least one kind of ultrafine particles selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride. A barrier substrate for an organic electroluminescence device according to claim.   The ultrafine particles are at least one ultrafine particle selected from the group consisting of indium, alkali metal, and alkaline earth metal, the surface of which is oxidized. The barrier substrate for organic electroluminescent elements according to any one of claims 3 to 3.   6. The barrier substrate for an organic electroluminescence element according to claim 1, wherein an average particle diameter of the ultrafine particles is in a range of 0.5 nm to 100 nm.   The organic electroluminescence element barrier property according to any one of claims 1 to 6, wherein a colored layer is formed between the substrate and the first inorganic insulating layer. substrate.   The organic electroluminescent element barrier according to any one of claims 1 to 7, wherein a color conversion layer is formed between the substrate and the first inorganic insulating layer. Substrate.   The organic electro according to any one of claims 1 to 8, wherein a transparent protective layer having an uneven shape is formed between the substrate and the first inorganic insulating layer. Barrier substrate for luminescence element.   A first inorganic insulating layer forming step of forming at least one vapor-deposited film on the substrate; and an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent is applied on the first inorganic insulating layer, and baked to form a film. A method for producing a barrier substrate for an organic electroluminescence element, comprising: forming a second inorganic insulating layer.   The barrier property for an organic electroluminescence element according to claim 10, wherein in the second inorganic insulating layer forming step, firing is performed in an atmosphere in which the ultrafine particles are not oxidized, and then firing in an oxidizing atmosphere. A method for manufacturing a substrate.   In the first inorganic insulating layer forming step, a lower vapor deposition film is formed on the substrate, and after polishing the lower vapor deposition film surface, an upper vapor deposition film is formed on the lower vapor deposition film. The manufacturing method of the barrier property board | substrate for organic electroluminescent elements of Claim 10 or Claim 11.   The method for producing a barrier substrate for an organic electroluminescent element according to any one of claims 10 to 12, wherein the solvent has a boiling point of 120 ° C or higher. The organic electroluminescent element barrier substrate according to any one of claims 1 to 9, and a transparent electrode layer formed on the second inorganic insulating layer of the organic electroluminescent element barrier substrate. And an organic electroluminescent layer formed on the transparent electrode layer and including at least a light emitting layer, and a back electrode layer formed on the organic electroluminescent layer.

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