JPWO2014199852A1 - Manufacturing method of surface light emitting panel provided with light emitting pattern and surface light emitting panel provided with light emitting pattern - Google Patents

Abstract

The subject of this invention is providing the surface emitting panel provided with the manufacturing method of the surface emitting panel provided with the light emission pattern excellent in the gradation characteristic, and the light emitting pattern manufactured by the manufacturing method. The manufacturing method of the surface emitting panel provided with the light emission pattern of the present invention includes at least a step of forming a light emission pattern by irradiating an organic electroluminescence panel provided with one or a plurality of organic functional layers between at least a pair of electrodes. A method of manufacturing a surface-emitting panel having a light-emitting pattern having a light-emitting luminance decrease in the light-irradiated organic electroluminescence panel in the step of forming the light-emitting pattern is the same as the light-emitting luminance before the light irradiation. A light emission pattern is formed by adjusting the light irradiation conditions so that the amount of voltage change necessary to achieve 1.0 V or less.

Description

  The present invention relates to a method for manufacturing a surface emitting panel having a light emitting pattern with excellent gradation characteristics, and a surface emitting panel having a light emitting pattern manufactured by the manufacturing method.

  Currently, organic light emitting panels are attracting attention as thin light emitting materials.

  Organic light-emitting elements (hereinafter also referred to as “organic EL elements”) using organic electroluminescence (EL) are thin-film complete solids that can emit light at a low voltage of about several volts to several tens of volts. The panel has many excellent features such as high brightness, high luminous efficiency, thinness, and light weight. For this reason, backlights of various displays using organic EL elements as panels, display boards such as signboards and emergency lights, and surface light emitters such as illumination light sources have attracted attention in recent years.

  Such an organic EL panel has a configuration in which a light emitting layer made of an organic material is disposed between two electrodes, and emitted light generated in the light emitting layer passes through the electrode and is extracted outside. For this reason, at least one of the two electrodes is configured as a transparent electrode, and emitted light is extracted from the transparent electrode side. In addition, the organic EL panel can obtain high luminance with low power, and is excellent in terms of visibility, response speed, life, and power consumption.

  Here, in such an organic EL panel, an organic EL panel having a light emitting pattern for forming a non-light emitting region by irradiating an organic functional layer laminated on a glass substrate with ultraviolet rays and deteriorating the irradiated portion. (For example, refer to Patent Document 1 and Patent Document 2).

  Further, when patterning is performed by irradiating the organic EL panel with ultraviolet rays, it is possible to form a light emission pattern having multi-tone light emission luminance by changing the irradiation light quantity.

  However, when patterning a natural image whose emission luminance continuously changes, it is difficult to reproduce a continuous tone natural image, resulting in an unnatural image, and it is difficult to obtain a preferable image.

Japanese Patent No. 2793373 JP 2012-28335 A

  The present invention has been made in view of the above-described problems and situations, and a solution to the problem is a method for manufacturing a surface-emitting panel having a light-emitting pattern with excellent gradation characteristics and a light-emitting pattern manufactured by the method. It is providing the surface emitting panel provided.

  In order to solve the above-mentioned problems, the present inventor has the light emission amount of the organic EL panel to which the gradation characteristic of the light-emitting pattern of the organic EL panel having the light-emitting pattern is irradiated in the process of examining the cause of the above-mentioned problem. It has been found that a light emission pattern with excellent gradation characteristics cannot be obtained by simply irradiating an image having a pattern with light, depending on the amount of change in electrical characteristics with respect to (hereinafter also referred to as “light change characteristics”). In particular, it has been found that when the sensitivity to patterning of the organic EL panel is high, it is difficult to control the light intensity during light irradiation. As a result of studying this, a natural patterned image with excellent gradation characteristics can be obtained by irradiating a specific condition between the irradiation light quantity and the light change characteristic of the organic EL panel. And found the present invention.

  That is, the said subject which concerns on this invention is solved by the following means.

1. A method of manufacturing a surface light emitting panel having a light emitting pattern having at least a step of forming a light emitting pattern by irradiating light to an organic electroluminescence panel including one or a plurality of organic functional layers between at least a pair of electrodes,
In the step of forming the light emission pattern, the amount of voltage change necessary to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel the same as the light emission luminance before the light irradiation is 1.0 V or less. A method for manufacturing a surface light emitting panel having a light emission pattern, wherein the light emission condition is adjusted to form a light emission pattern.

2. Light irradiation to an organic electroluminescence panel having a voltage-luminescence luminance curve in which the amount of voltage change required for the emission luminance of the organic electroluminescence panel to change from 300 cd / m ² to 3000 cd / m ² is 1.0 V or more A method for manufacturing a surface light emitting panel comprising the light emitting pattern according to item 1, wherein a light emitting pattern is formed.

3. A surface-emitting panel having a light-emitting pattern manufactured by the method for manufacturing a surface-emitting panel having the light-emitting pattern according to item 1 or 2, wherein the organic electroluminescence panel has an emission luminance of 300 cd / d. The amount of voltage change required to change from m ² to 3000 cd / m ² is manufactured by irradiating an organic electroluminescence panel having a voltage-luminescence luminance curve with a voltage of 1.0 V or more to form a light emission pattern, And a light emission pattern characterized in that a change in voltage required to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel equal to the light emission luminance before the light irradiation is 1.0 V or less. Equipped with a surface-emitting panel.

  By the above means of the present invention, it is possible to provide a method for manufacturing a surface emitting panel having a light emitting pattern with excellent gradation characteristics and a surface emitting panel having a light emitting pattern manufactured by the manufacturing method.

  The expression mechanism or action mechanism of the effect of the present invention is presumed as follows.

  When manufacturing a surface-emitting panel with a light emission pattern by irradiating the organic EL panel with light such as ultraviolet light, the organic EL panel has various sensitivities for receiving and patterning light such as ultraviolet light. Even if an image having a pattern is simply irradiated with light, a light emission pattern with excellent gradation characteristics cannot be obtained. As in the configuration of the present invention, by irradiating so as to satisfy a specific condition between the irradiation light amount and the light change characteristic of the organic EL panel, it is easy to control the intensity when irradiating light and tones It is considered that a light emission pattern with excellent gradation characteristics can be obtained because it is easy to reproduce the continuity of the pattern within the range of the reproduction luminance.

Sectional drawing which shows schematic structure of organic electroluminescent panel Example of voltage-light emission luminance curve of organic EL panel

The manufacturing method of the surface emitting panel provided with the light emission pattern of the present invention includes at least a step of forming a light emission pattern by irradiating an organic electroluminescence panel provided with one or a plurality of organic functional layers between at least a pair of electrodes. A method of manufacturing a surface-emitting panel having a light-emitting pattern,
In the step of forming the light emission pattern, the amount of voltage change necessary to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel the same as the light emission luminance before the light irradiation is 1.0 V or less. As described above, the light emission conditions are adjusted to form a light emission pattern. This feature is a technical feature common to the inventions according to claims 1 to 3.

As an embodiment of the present invention, from the viewpoint of manifesting the effects of the present invention, the amount of voltage change required for the light emission luminance of the organic electroluminescence panel to change from 300 cd / m ² to 3000 cd / m ² is 1.0 V. It is preferable to form a light emission pattern by irradiating light to the organic electroluminescence panel having the voltage-light emission luminance curve as described above.

The organic electroluminescence panel having a voltage-luminescence luminance curve in which the amount of voltage change required for the emission luminance of the organic electroluminescence panel to change from 300 cd / m ² to 3000 cd / m ² is 1.0 V or more is irradiated with light. The amount of voltage change required for the reduction in the light emission luminance of the organic electroluminescence panel that has been manufactured by forming the light emission pattern to be the same as the light emission luminance before the light irradiation is 1.0 V. It is preferable that it is a surface emitting panel provided with the following light emission patterns.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<< Outline of manufacturing method of surface emitting panel with light emitting pattern >>
The manufacturing method of the surface emitting panel provided with the light emission pattern of the present invention includes at least a step of forming a light emission pattern by irradiating an organic electroluminescence panel provided with one or a plurality of organic functional layers between at least a pair of electrodes. A method of manufacturing a surface-emitting panel having a light-emitting pattern,
In the step of forming the light emission pattern, the amount of voltage change necessary to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel the same as the light emission luminance before the light irradiation is 1.0 V or less. As described above, the light emission conditions are adjusted to form a light emission pattern.

  Here, the “pattern” refers to a design (design or pattern in the figure), characters, images, etc. displayed by the organic electroluminescence panel. “Patterning” means providing these pattern display functions.

  “Light emission pattern” means that when an organic electroluminescence panel emits light, light is emitted by changing the light emission intensity (luminance) depending on the position of the light emitting surface based on a predetermined design (pattern or pattern in the figure), characters, images, etc. A source having a function of displaying a predetermined design (pattern or pattern in the figure), characters, images, etc. formed (applied) in advance on the organic electroluminescence panel to emit light.

  The present invention can be preferably applied not only to natural images such as landscapes and people but also to patterns having intermediate gradations.

<Formation of light emission pattern>
The formation of the light emission pattern is performed by a process of forming a light emission pattern by light irradiation described below (hereinafter also referred to as a light irradiation process). Hereinafter, the formation of the light emission pattern will be described.

  In the step of forming the light emission pattern, light is emitted so that the amount of voltage change necessary to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel the same as the light emission luminance before light irradiation is 1.0 V or less. A light emission pattern is formed by adjusting irradiation conditions.

  When the organic EL panel is irradiated with light, the luminance of the light-irradiated portion decreases. By continuously changing the light irradiation amount, a surface light emitting panel having a light emitting pattern made of an organic EL panel having a light emitting pattern having gradation can be manufactured.

  However, it varies greatly depending on the light change characteristics of the organic EL panel to be irradiated, and a light emission pattern with excellent gradation characteristics cannot be obtained by simply irradiating an image having a pattern. In particular, it has been found that when the sensitivity to patterning of the organic EL panel is high, it is difficult to control the light intensity during light irradiation. As a result of studying this, the light irradiation conditions were set so that the amount of voltage change necessary to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel the same as the light emission luminance before light irradiation was 1.0 V or less. It was found that a natural patterned image having excellent gradation characteristics can be obtained by adjusting the light emission to form a light emission pattern, and the present invention has been achieved.

  By irradiating the light so as to satisfy a specific condition between the light irradiation amount and the light change characteristics of the organic EL panel, it is easy to control the intensity and reproduce the continuity of gradation. It is presumed that a light emission pattern with excellent gradation characteristics can be obtained because it becomes easy to pattern within the luminance range.

  By irradiating the organic EL panel with light, the drive voltage increases in the light-irradiated portion, and the light emission luminance decreases accordingly. This characteristic varies greatly depending on the organic EL panel. For example, when the light change characteristic of the organic EL panel with respect to light irradiation greatly reduces the emitted light amount luminance even with a small amount of light, it becomes difficult to control the light intensity. In addition, it becomes difficult to reproduce the continuity of gradation within the reproduction luminance range.

  The light emission pattern is adjusted by adjusting the light irradiation conditions so that the change in voltage necessary to make the decrease in the light emission luminance of the organic EL panel irradiated with light the same as the light emission luminance before light irradiation is 1.0 V or less. By forming it, a light emission pattern with excellent gradation characteristics can be obtained.

  The light irradiation condition can be adjusted by examining the light change characteristics of the organic EL panel in advance and adjusting the light irradiation amount so that the above voltage change amount is obtained.

  “The amount of voltage change necessary to make the emission luminance before light irradiation equal to 1.0 V or less” means that when a driving voltage is applied to the light-irradiated portion of the organic EL panel, light irradiation is performed. This is an increase in voltage necessary to obtain the same light emission luminance as the previous light emission luminance. When light with a different amount of light irradiation is irradiated on the surface, it indicates the amount of change in the part with the largest amount of light irradiation. As described above, the portion with the largest amount of light irradiation has the largest amount of voltage change, and thus becomes the darkest part. When this value is larger than 1.0 V, the patterned image cannot effectively use the maximum light emission luminance and the light emission luminance region up to the darkest part of the organic EL panel, resulting in an image with poor gradation. On the other hand, if this value is too small, the image will have a low contrast. The lower limit is preferably 0.3V.

Further, the amount of voltage change at the light irradiation site also depends on the light emission luminance. That is, even when the light irradiation amount is the same, for example, the amount of voltage change is different between when light emission is performed at 300 cd / m ² and when light emission is performed at 3000 cd / m ² . Of course, it is important that the amount of voltage change in the light emission luminance in which the surface light emitting panel is used is 1.0 V or less.

  Therefore, the amount of voltage change necessary to make the light emission luminance of the light emitting part that generates the darkest part that received the most light irradiation the same as the light emission luminance before light irradiation (non-light irradiation part: brightest part) is 1. In order to adjust the light irradiation conditions so as to be 0 V or less, it is necessary to change the light irradiation conditions depending on the luminance of the light emitting unit used.

For example, in a case where the external environment is bright and needs to be visible from a distance such as a sign for outdoor use, the amount of voltage change from the darkest part with bright light emission luminance must be 1.0 V or less. On the other hand, in the case of an application where the room is directly viewed from a relatively close distance, for example, it is important that the voltage change amount from the darkest part is 1.0 V or less at a brightness of about 300 cd / m ² . That is, in the present invention, the light emission luminance with the voltage change amount from the darkest portion being 1.0 V or less refers to the light emission luminance of the brightest portion that emits the brightest light when the surface light emitting panel is used. The luminance of the non-irradiated part corresponds to this part. By irradiating light with the light emission luminance so as to have the voltage change amount, an in-plane light emitting panel having excellent gradation characteristics can be obtained.

A preferable range of the maximum luminance is 150 to 5000 cd / m ² . Although it depends on the application, it is preferably in the range of 300 to 3000 cd / m ² .

  The emission luminance can be measured using a general luminance meter. For example, it can be measured with a two-dimensional color luminance meter CS-2000 manufactured by Konica Minolta.

<Configuration of organic electroluminescence panel>
The organic EL panel according to the present invention includes one or a plurality of organic functional layers between at least a pair of electrodes. The organic functional layer in the present invention refers to a layer containing an organic compound. Examples thereof include a hole injection layer, a hole transport layer, a light emitting layer (including a blue light emitting layer, a green light emitting layer, and a red light emitting layer), an electron transport layer, and an electron injection layer. The organic functional layer preferably includes a light emitting layer.

  The organic EL panel according to the present invention can take various configurations, and an example is shown in FIG.

  As shown in FIG. 1, an organic EL panel 10 according to the present invention is provided on a substrate 13, and is configured by using a first electrode (transparent electrode) 1, an organic material, and the like in order from the substrate 13 side. The functional layer 3 and the second electrode (counter electrode) 5a are stacked in this order. An extraction electrode 16 is provided at the end of the first electrode 1 (electrode layer 1b). The first electrode 1 and an external power source (not shown) are electrically connected via the extraction electrode 16. The organic EL panel 10 is configured to extract the generated light (emitted light h) from at least the substrate 13 side.

  Further, the layer structure of the organic EL panel 10 is not limited and may be a general layer structure. Here, the first electrode 1 functions as an anode (that is, an anode), and the second electrode 5a functions as a cathode (that is, a cathode). In this case, for example, the organic functional layer 3 has a structure in which a hole injection layer 3a / a hole transport layer 3b / a light emitting layer 3c / an electron transport layer 3d / an electron injection layer 3e are stacked in this order from the first electrode 1 side that is an anode. Of these, it is essential to have the light emitting layer 3c composed of at least an organic material. The hole injection layer 3a and the hole transport layer 3b may be provided as a hole transport injection layer. The electron transport layer 3d and the electron injection layer 3e may be provided as an electron transport injection layer. Of these organic functional layers 3, for example, the electron injection layer 3e may be made of an inorganic material.

  In addition to these layers, the organic functional layer 3 may be laminated with a hole blocking layer, an electron blocking layer, or the like as necessary. Furthermore, the light emitting layer 3c may have a structure in which each color light emitting layer that generates emitted light in each wavelength region is laminated, and each of these color light emitting layers is laminated via a non-light emitting intermediate layer. The intermediate layer may function as a hole blocking layer and an electron blocking layer. Furthermore, the second electrode 5a, which is a cathode, may also have a laminated structure as necessary. In such a configuration, only a portion where the organic functional layer 3 is sandwiched between the first electrode 1 and the second electrode 5 a becomes a light emitting region in the organic EL panel 10.

  In the layer configuration as described above, the auxiliary electrode 15 may be provided in contact with the electrode layer 1 b of the first electrode 1 for the purpose of reducing the resistance of the first electrode 1.

  The organic EL panel 10 having the above configuration is sealed on the substrate 13 with a sealing material 17 described later for the purpose of preventing deterioration of the organic functional layer 3 configured using an organic material or the like. Yes. The sealing material 17 is fixed to the substrate 13 side through an adhesive 19. However, the terminal portions of the first electrode 1 (extraction electrode 16) and the second electrode 5a are provided in a state where they are exposed from the sealing material 17 on the substrate 13 while being insulated from each other by the organic functional layer 3. ing.

<Voltage-emission luminance curve>
The organic EL panel used in the present invention, in a process of manufacturing the organic EL panel, light emission luminance of the organic EL panel, the voltage - in the emission luminance curve, required for the change from 300 cd / ^{m 2} to 3000 cd / ^{m 2} It is preferable that the voltage change amount is 1.0 V or more.

The voltage-light emission luminance curve (hereinafter also referred to as VL curve) is a curve representing the relationship of the light emission luminance L (cd / m ² ) to the applied voltage V (V) in the organic EL panel. When the slope of the VL curve is large, the brightness increases sharply as the voltage is gradually increased. When the slope of the VL curve is small, the luminance gradually increases as the voltage is gradually increased. The former is advantageous for gradation expression because it is difficult to adjust the luminance and the latter is easy.

  FIG. 2 is an example of a VL curve of the organic EL panel. When a voltage is applied to the organic EL panel, the amount of light emission is small at first, but it rises rapidly as the voltage increases, and it can be seen that the increase in light emission luminance is large even if the voltage increases slightly.

Since the organic EL is a diode, the relationship (V-J) of the current density J (A / m ² ) to the voltage V (V) indicates the diode characteristics. When the applied voltage exceeds the threshold voltage, a current starts to flow, and when the applied voltage is further increased, a current flows steeply. Further, the relationship (JL) between the current density J (A / m ² ) and the luminance L (cd / m ² ) is almost constant in the practical range. That is, the VL relationship also shows diode characteristics.

In the present invention, in the step of producing an organic electroluminescent panel which will be described later, the voltage - in the emission luminance curves, the voltage variation required for changing from 300 cd / ^{m 2} to 3000 cd / ^{m 2} is more than 1.0V It is preferable to make it as follows.

  By manufacturing an organic EL panel in this way, not only can the emission luminance during light emission be precisely controlled, but an organic EL panel having a steep curve generally has a steep light change characteristic with respect to light irradiation. Slowing is very effective in the manufacture of a surface light emitting panel having a light emitting pattern with excellent gradation because an image at the time of patterning can be precisely controlled.

  This value is preferably 1.0 V or more, but if it is too large, the contrast may decrease. More preferably, it exists in the range of 1.0-3.0V. More preferably, it exists in the range of 1.0-2.0V.

  In general, when the resistance component of an electrical panel increases, the current gradient with respect to voltage (R (Ω) in the case of resistance) decreases, making it easy to adjust the current density by adjusting the applied voltage, and at the same time easily adjusting the brightness by adjusting the applied voltage. become. Therefore, in order to reduce the slope of the VL curve, it is preferable to increase the resistance component of the organic EL panel.

<V-L curve adjustment means>
The organic EL panel having general characteristics is difficult to adjust the characteristics depending on the light intensity, and it tends to be an ON / OFF image, so that gradation expression is poor. In order to obtain a characteristic in which the slope of the VL curve is small, for example, the following method can be used in the step of manufacturing an organic EL panel described later. However, it is not limited to this.

  (1) Increasing the layer thickness of the organic EL panel: Increasing the resistance of the organic EL panel by increasing the thickness of a specific layer or a plurality of layers, thereby reducing the slope of the VJ curve. Can do. In general, since the J-L relationship is proportional in the practical range, the slope of the VL curve becomes small. At this time, it is desirable to thicken both sides rather than thickening only the hole side or the electron side so as not to break the recombination balance. Specifically, by increasing the thickness of any of the organic layers located on both sides of the light emitting layer from about 90 nm to about 150 nm, the resistance value can be increased and the slope of the VL curve can be reduced.

  (2) Unit lamination of organic EL panel: A structure in which units of a hole injection layer, a light emitting layer, and an electron injection layer are laminated between both electrodes has been proposed. By using an organic EL panel having such stacked units, the voltage increases but the quantum efficiency decreases. The theoretical power efficiency does not change. Thus, by stacking the units in two stages and three stages, the inclination of the VJ curve, that is, the VL curve can be reduced.

  (3) Insert a resistance component in series with the organic EL panel. Since a voltage drop due to resistance is added, the VJ curve is the sum of the diode characteristics of the organic EL panel and the linear characteristics of the resistance. By adding an appropriate resistance component outside the panel, it is possible to reduce the slope of the VJ curve, that is, the VL curve.

  The manufacturing method of the surface emitting panel provided with the light emission pattern of this invention has at least the process of irradiating light to an organic electroluminescent panel and forming a light emission pattern. Each step will be described below.

<Process for producing organic electroluminescence panel>
Here, as an example, a method for manufacturing the organic EL panel 10 shown in FIG. 1 will be described.

(1) Lamination process In the manufacturing method of the organic electroluminescent panel which concerns on this invention, the process (lamination process) which laminates | stacks and forms the 1st electrode 1, the organic functional layer 3, and the 2nd electrode 5a on the board | substrate 13 is performed.

  First, a substrate 13 is prepared, and an underlayer 1a made of, for example, a nitrogen-containing compound containing nitrogen atoms is deposited on the substrate 13 so as to have a layer thickness of 1 μm or less, preferably 10 to 100 nm. It forms by appropriate methods, such as.

  Next, the electrode layer 1b made of silver (or an alloy containing silver as a main component) is formed on the base layer 1a by an appropriate method such as vapor deposition so that the layer thickness is 12 nm or less, preferably 4 to 9 nm. The first electrode 1 is formed to be an anode. At the same time, an extraction electrode 16 connected to an external power source is formed at the end of the first electrode 1 by an appropriate method such as vapor deposition.

  Next, a hole injection layer 3a, a hole transport layer 3b, a light emitting layer 3c, an electron transport layer 3d, and an electron injection layer 3e are laminated in this order to form the organic functional layer 3.

The formation of each of these layers includes spin coating, casting, inkjet, vapor deposition, and printing, but vacuum vapor deposition is easy because a homogeneous layer is easily obtained and pinholes are difficult to generate. The method or spin coating method is particularly preferred. Further, different formation methods may be applied for each layer. When employing a vapor deposition method for forming each of these layers, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C. and a degree of vacuum of 1 × 10 ⁻⁶ to 1 × 10 ⁻² Pa. It is desirable to appropriately select the respective conditions within the ranges of the deposition rate of 0.01 to 50 nm / second, the substrate temperature of −50 to 300 ° C., and the layer thickness of 0.1 to 5 μm.

  After the organic functional layer 3 is formed as described above, the second electrode 5a serving as a cathode is formed thereon by an appropriate forming method such as a vapor deposition method or a sputtering method. At this time, the second electrode 5 a is patterned in a shape in which a terminal portion is drawn from the upper side of the organic functional layer 3 to the periphery of the resin substrate 13 while being insulated from the first electrode 1 by the organic functional layer 3. .

As described above, when the VL curve of the organic EL panel manufactured in this way is changed from 300 cd / m ² to 3000 cd / m ² , the voltage change amount is not 1.0 V or more. As described above, it is preferable that the voltage change amount is 1.0 V or more by taking measures such as increasing the thickness of the organic layer.

(2) Sealing step After the stacking step, a step of sealing the organic functional layer 3 (sealing step) is performed.

  That is, the sealing material 17 that covers at least the organic functional layer 3 is provided on the resin substrate 13 with the terminal portions of the first electrode 1 (extraction electrode 16) and the second electrode 5a exposed.

<Step of forming a light emission pattern by light irradiation>
The step of forming a light emission pattern by light irradiation (also referred to as a light irradiation step) is a step of forming a light emission pattern by irradiating the organic electroluminescence panel with light. The organic EL panel 10 having a light emission pattern can be manufactured by modulating the light emission function of the organic functional layer 3 by irradiating light. In the light irradiation step, the light irradiation method may be any method as long as the irradiation portion can be changed to a light emitting region whose luminance is changed by irradiating the predetermined pattern region of the organic functional layer 3 with the predetermined light. Well, it is not limited to a specific method.

  The light irradiated in the light irradiation step may further contain ultraviolet rays, visible light or infrared rays, but preferably contains ultraviolet rays.

  Here, in the present invention, ultraviolet rays refer to electromagnetic waves having a wavelength longer than that of X-rays and shorter than the shortest wavelength of visible light, and specifically, those having a wavelength of 1 to 400 nm.

  The ultraviolet ray generating means and the irradiating means are not particularly limited as long as the ultraviolet ray is generated and irradiated by a conventionally known apparatus or the like. Specific examples of the light source include a high-pressure mercury lamp, a low-pressure mercury lamp, a hydrogen (deuterium) lamp, a rare gas (xenon, argon, helium, neon, etc.) discharge lamp, a nitrogen laser, and an excimer laser (XeCl, XeF, KrF, KrCl). Etc.), hydrogen lasers, halogen lasers, various harmonics of visible (LD) -infrared lasers (THG (Third Harmonic Generation) light of YAG lasers) and the like.

  Such a light irradiation process is preferably performed after the sealing process.

  Here, when the 2nd electrode 5a does not have translucency, light irradiation is performed from the light extraction surface 13a side of the board | substrate 13. FIG. In this case, since the organic functional layer 3 is irradiated with light through the substrate 13, it is necessary to secure a sufficient light irradiation time in consideration of the fact that the substrate 13 absorbs the irradiation light to some extent. Further, since the light irradiation step is performed after the sealing step, the panel after sealing can be exposed to the atmosphere (open system), and it is not necessary to perform the light irradiation step in a closed system such as in a chamber. For this reason, the organic EL panel which has a light emission pattern is producible with a low-cost and simple manufacturing process.

  The light irradiation step may be performed before the sealing step, and is performed after the organic functional layer 3 is formed in the stacking step and before the second electrode 5a is formed. Also good. In this case, light may be irradiated from the substrate 13 side, or light may be irradiated from the organic functional layer 3 side.

  Further, in the light irradiation step, by adjusting the light intensity or the irradiation time and changing the light irradiation amount, it is possible to change the light emission luminance of the light irradiation portion according to the light irradiation amount. The greater the light irradiation amount, the lower the emission luminance, and the smaller the light irradiation amount, the smaller the emission luminance attenuation rate. Therefore, when the light irradiation amount is 0, that is, when no light is irradiated, the light emission luminance is maximum.

  Thereby, in the produced organic EL panel, it is possible to increase and decrease the emission luminance, and it is also possible to change the intensity by increasing or decreasing the drive current. In addition, the drive voltage increases as the luminance decreases, but the emission luminance-voltage curve is stable over time. Therefore, it is possible to manufacture an organic EL panel in which the intensity of light emission appears in the light emitting region during light emission.

  As described above, an organic EL panel having a desired light emission pattern can be produced. In the manufacture of such an organic EL panel 10, it is preferable to consistently produce from the organic functional layer 3 to the second electrode 5a by one evacuation, but different formations are made by taking out the substrate 13 from the vacuum atmosphere in the middle. You may apply the law. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  When a DC voltage is applied to the organic EL panel 10 thus obtained, the first electrode 1 as an anode has a positive polarity, the second electrode 5a as a cathode has a negative polarity, and a voltage of 2 to 2. Luminescence can be observed when about 40 V is applied. Moreover, you may apply an alternating voltage. The alternating current waveform to be applied may be arbitrary.

≪Details of each layer constituting organic EL panel and manufacturing method≫
Hereinafter, the details of the main layers for forming the organic EL panel 10 described above and the manufacturing method thereof will be described.

<Board>
The substrate 13 is basically preferably composed of a base material as a support and one or more barrier layers having a refractive index of 1.4 or more and 1.7 or less.

(1) Base material The base material which concerns on this invention can use a conventionally well-known base material without a restriction | limiting in particular. The substrate preferably used in the present invention preferably has gas barrier properties such as moisture resistance / gas permeability resistance required for the organic EL panel.

  In this invention, when the board | substrate 13 side of the organic electroluminescent panel 10 becomes a light emission surface, the material which has translucency with respect to visible light is used for a base material. In this case, the light transmittance at a wavelength of 550 nm is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more.

  Moreover, it is preferable that a base material has flexibility. The term “flexibility” as used herein refers to a base material that is wound around a φ (diameter) 50 mm roll and is not cracked before and after winding with a constant tension, and more preferably a base that can be wound around a φ30 mm roll. Say the material.

  In the present invention, the base material is a conventionally known base material, for example, alkali-free glass, soda glass, resin base materials such as acrylic ester, methacrylic ester, PMMA, etc., polyethylene terephthalate (PET), Polybutylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), nylon (Ny), aromatic polyamide, Examples include resin films such as polyetheretherketone, polysulfone, polyethersulfonate, polyimide, polyetherimide, polyolefin, epoxy resin, and cycloolefin-based and cellulose ester-based ones. It can be. In addition, a heat-resistant transparent film (product name Sila-DEC, manufactured by Chisso Corporation) having a silsesquioxane having an organic-inorganic hybrid structure as a basic skeleton, and a resin film formed by laminating two or more layers of the resin material, etc. Can be mentioned.

  From the viewpoint of cost and availability, alkali-free glass, soda glass, PET, PEN, PC, acrylic resin, and the like are preferably used.

  In the case of a resin base material, a biaxially stretched polyethylene terephthalate film and a biaxially stretched polyethylene naphthalate film are preferable from the viewpoints of transparency, heat resistance, ease of handling, strength, and cost.

  Furthermore, in order to suppress the shrinkage at the time of thermal expansion to the maximum, a low heat recovery processed product subjected to a treatment such as thermal annealing is most preferable.

  As for the thickness of a base material, 10-500 micrometers is preferable, More preferably, it is 20-250 micrometers, More preferably, it is 30-150 micrometers. When the thickness of the base material is in the range of 10 to 500 μm, a stable gas barrier property can be obtained, and it is suitable for conveyance in a roll-to-roll system.

(2) Barrier layer (2.1) Characteristics and formation method In the present invention, the base material of the substrate 13 has one or more barrier layers (low refractive index layer) having a refractive index of 1.4 or more and 1.7 or less. May be provided. As such a barrier layer, a known material can be used without particular limitation, and a film made of an inorganic material or an organic material or a hybrid film combining these films may be used. The barrier layer has a water vapor transmission rate (25 ± 0.5 ° C., relative humidity 90 ± 2% RH) of 0.01 g / (m ² · 24 hours) or less, as measured by a method according to JIS K 7129-1992. The oxygen permeability measured by a method according to JIS K 7126-1987 is preferably 1 × 10 ⁻³ ml / (m ² · 24 hours · atm) or less, and a water vapor permeability of 1 × 10 ⁻⁵ g / (m ² · 24 hours) or less is more preferable.

  As a material for forming such a barrier layer, any material may be used as long as it has a function of suppressing intrusion of water or oxygen that causes panel deterioration. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Furthermore, in order to improve the fragility of the barrier layer, a layer (organic layer) made of an organic material as a stress relaxation layer may be laminated on these inorganic layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier layer is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method described in JP 2004-68143 A is particularly preferable.

(2.2) Inorganic Precursor Compound The barrier layer may be formed by applying a coating solution containing at least one layer of an inorganic precursor compound on a substrate.

  Any appropriate method can be adopted as a coating method.

  Specific examples include a roll coating method, a flow coating method, an ink jet method, a spray coating method, a printing method, a dip coating method, a casting film forming method, a bar coating method, and a gravure printing method.

  The coating thickness can be appropriately set according to the purpose. For example, the coating thickness can be set so that the layer thickness after drying is preferably about 0.001 to 10 μm, more preferably about 0.01 to 10 μm, and most preferably about 0.03 to 1 μm.

  The inorganic precursor compound used in the present invention is not particularly limited as long as it is a compound capable of forming a metal oxide, a metal nitride, or a metal oxynitride by vacuum ultraviolet irradiation under a specific atmosphere. A compound suitable for the method is preferably a compound that can be modified at a relatively low temperature as described in JP-A-8-112879.

  Specifically, polysiloxane (including polysilsesquioxane) having Si—O—Si bond, polysilazane having Si—N—Si bond, both Si—O—Si bond and Si—N—Si bond Polysiloxazan containing can be raised. These can be used in combination of two or more. Moreover, it can be used even if different compounds are sequentially laminated or simultaneously laminated.

<First electrode (transparent electrode)>
As the first electrode, it is possible to use all the electrodes that can be normally used for the organic EL panel. Specifically, aluminum, silver, magnesium, lithium, magnesium / same mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, indium, lithium / aluminum mixture, rare earth metal, ITO, ZnO, TiO ₂ , An oxide semiconductor such as SnO ₂ can be given.

  In the present invention, the first electrode is preferably a transparent electrode, and more preferably a transparent metal electrode.

  For example, as shown in FIG. 1, the first electrode 1 has a two-layer structure in which a base layer 1a and an electrode layer 1b formed thereon are sequentially laminated from the substrate 13 side. Among these, the electrode layer 1b is a layer configured using, for example, silver or an alloy containing silver as a main component, and the base layer 1a is a layer configured using, for example, a compound containing nitrogen atoms. is there.

  The first electrode 1 being transparent means that the light transmittance at a wavelength of 550 nm is 50% or more. The main component in the electrode layer 1b means that the content in the electrode layer 1b is 98% by mass or more.

(1) Underlayer The underlayer 1a is a layer provided on the substrate 13 side of the electrode layer 1b. The material constituting the underlayer 1a is not particularly limited as long as it can suppress the aggregation of silver when forming the electrode layer 1b made of silver or an alloy containing silver as a main component. And nitrogen-containing compounds containing a nitrogen atom.

  When the underlayer 1a is made of a low refractive index material (refractive index less than 1.7), the upper limit of the layer thickness needs to be less than 50 nm, preferably less than 30 nm, and preferably less than 10 nm. Is more preferable, and it is especially preferable that it is less than 5 nm. By making the layer thickness less than 50 nm, optical loss can be minimized. On the other hand, the lower limit of the layer thickness is required to be 0.05 nm or more, preferably 0.1 nm or more, and particularly preferably 0.3 nm or more. By setting the layer thickness to 0.05 nm or more, it is possible to make the underlayer 1a uniform and to make the effect (inhibition of aggregation of silver) uniform.

  When the underlayer 1a is made of a high refractive index material (refractive index of 1.7 or more), the upper limit of the layer thickness is not particularly limited, and the lower limit of the layer thickness is the same as that of the low refractive index material. is there.

  However, as a simple function of the base layer 1a, it is sufficient if the base layer 1a is formed with a necessary layer thickness that allows uniform film formation.

  As a method for forming the underlying layer 1a, a wet process such as a coating method, an inkjet method, a coating method, or a dip method, a dry process such as a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like is used. And the like. Among these, the vapor deposition method is preferably applied.

  The compound containing a nitrogen atom constituting the underlayer 1a is not particularly limited as long as it is a compound containing a nitrogen atom in the molecule, but is preferably a compound having a heterocycle having a nitrogen atom as a heteroatom. . Examples of the heterocycle having a nitrogen atom as a hetero atom include aziridine, azirine, azetidine, azeto, azolidine, azole, azinane, pyridine, azepan, azepine, imidazole, pyrazole, oxazole, thiazole, imidazoline, pyrazine, morpholine, thiazine, indole, Examples include isoindole, benzimidazole, purine, quinoline, isoquinoline, quinoxaline, cinnoline, pteridine, acridine, carbazole, benzo-C-cinnoline, porphyrin, chlorin, choline and the like.

(2) Electrode layer The electrode layer 1b is a layer formed using silver or an alloy containing silver as a main component, and is a layer formed on the base layer 1a.

  As a method for forming such an electrode layer 1b, a method using a wet process such as a coating method, an inkjet method, a coating method, a dip method, a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like. And a method using the dry process. Among these, the vapor deposition method is preferably applied.

  In addition, the electrode layer 1b is formed on the base layer 1a, so that the electrode layer 1b is sufficiently conductive without high-temperature annealing after the electrode layer 1b is formed. In addition, high temperature annealing treatment or the like after film formation may be performed.

  Examples of the alloy mainly composed of silver (Ag) constituting the electrode layer 1b include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), and silver indium (AgIn). ) And the like.

  The electrode layer 1b as described above may have a structure in which silver or an alloy layer mainly composed of silver is divided into a plurality of layers as necessary.

  Furthermore, the electrode layer 1b preferably has a thickness of 12 nm or less, and more preferably in the range of 4 to 9 nm. When the layer thickness is less than 9 nm, the absorption component or reflection component of the layer is small, and the transmittance of the first electrode 1 is increased. Further, when the layer thickness is thicker than 4 nm, the conductivity of the layer can be sufficiently secured.

  The first electrode 1 having a laminated structure composed of the base layer 1a and the electrode layer 1b formed thereon is covered with a protective film at the upper part of the electrode layer 1b or another electrode layer. May be laminated. In this case, it is preferable that the protective film and the other electrode layer have light transmittance so that the light transmittance of the first electrode 1 is not impaired.

(3) Effect of First Electrode (Transparent Electrode) The first electrode 1 having the above-described configuration includes, for example, silver or silver as a main component on an underlayer 1a configured using a compound containing a nitrogen atom. The electrode layer 1b made of an alloy is provided. As a result, when the electrode layer 1b is formed on the underlayer 1a, the silver atoms constituting the electrode layer 1b interact with the compound containing nitrogen atoms constituting the underlayer 1a. The diffusion distance on the surface of the formation 1a is reduced, and silver aggregation is suppressed.

  Here, in general, in the film formation of the electrode layer 1b containing silver as a main component, since a thin film is grown by a nucleus growth type (Volume-Weber: VW type), the silver particles are easily isolated in an island shape, and the layer thickness is increased. When the thickness is thin, it is difficult to obtain conductivity, and the sheet resistance value becomes high. Therefore, in order to ensure conductivity, it is necessary to increase the layer thickness. However, if the layer thickness is increased, the light transmittance is lowered, so that it is not suitable as the first electrode.

  However, according to the first electrode 1, since aggregation of silver is suppressed on the underlayer 1 a as described above, in the film formation of the electrode layer 1 b made of silver or an alloy containing silver as a main component, single layer growth is performed. A thin film grows by a type (Frank-van der Merwe: FM type).

  Here, the transparency of the first electrode 1 means that the light transmittance at a wavelength of 550 nm is 50% or more. However, each of the materials used as the underlayer 1a is mainly composed of silver or silver. Compared with the electrode layer 1b made of an alloy, the film is sufficiently light-transmissive. On the other hand, the conductivity of the first electrode 1 is mainly ensured by the electrode layer 1b. Therefore, as described above, the electrode layer 1b made of silver or an alloy containing silver as a main component has a thinner layer and the conductivity is ensured, thereby improving the conductivity of the first electrode 1. It is possible to achieve both improvement of light transmittance.

<Organic functional layer>
(1) Light-Emitting Layer The organic functional layer 3 includes at least a light-emitting layer 3c.

  The light emitting layer 3c used in the present invention preferably contains a phosphorescent light emitting compound as a light emitting material. Note that a fluorescent material may be used as the light emitting material, or a phosphorescent light emitting compound and a fluorescent material may be used in combination.

  The light emitting layer 3c is a layer that emits light by recombination of electrons injected from the electrode or the electron transport layer 3d and holes injected from the hole transport layer 3b, and the light emitting portion is the light emitting layer 3c. Even within the layer, it may be the interface between the light emitting layer 3c and the adjacent layer.

  There is no restriction | limiting in particular in the structure as such a light emitting layer 3c, if the light emitting material contained satisfies the light emission requirements. There may be a plurality of layers having the same emission spectrum and emission maximum wavelength. In this case, it is preferable to have a non-light emitting intermediate layer (not shown) between the light emitting layers 3c.

  The total thickness of the light emitting layer 3c is preferably in the range of 1 to 100 nm, and more preferably in the range of 1 to 30 nm because a lower driving voltage can be obtained.

  In addition, the sum total of the layer thickness of the light emitting layer 3c is a layer thickness also including the said intermediate | middle layer, when a nonluminous intermediate | middle layer exists between the light emitting layers 3c.

  In the case of the light emitting layer 3c having a configuration in which a plurality of layers are laminated, the thickness of each light emitting layer is preferably adjusted within a range of 1 to 50 nm, and more preferably adjusted within a range of 1 to 20 nm. preferable. When the plurality of stacked light emitting layers correspond to the respective emission colors of blue, green, and red, there is no particular limitation on the relationship between the thicknesses of the blue, green, and red light emitting layers.

  The light emitting layer 3c as described above is formed by forming a known light emitting material or host compound by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, or the like. be able to.

  The light emitting layer 3c may be a mixture of a plurality of light emitting materials.

  As a structure of the light emitting layer 3c, it is preferable to contain a host compound (also referred to as a light emitting host or the like) and a light emitting material (also referred to as a light emitting dopant) to emit light from the light emitting material.

(2) Injection layer (hole injection layer, electron injection layer)
The injection layer is a layer provided between the electrode and the light emitting layer 3c in order to lower the driving voltage and improve the light emission luminance. “The organic EL panel and its forefront of industrialization (November 30, 1998, NT. 2) Chapter 2 “Electrode Materials” (pages 123 to 166) of the 2nd volume of “S. Co., Ltd.”, which includes a hole injection layer 3a and an electron injection layer 3e.

  The injection layer can be provided as necessary. The hole injection layer 3a may be present between the anode and the light emitting layer 3c or the hole transport layer 3b, and the electron injection layer 3e may be present between the cathode and the light emitting layer 3c or the electron transport layer 3d.

  The details of the hole injection layer 3a are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, and the like. Specific examples thereof include phthalocyanine represented by copper phthalocyanine. Examples thereof include a layer, an oxide layer typified by vanadium oxide, an amorphous carbon layer, and a polymer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the electron injection layer 3e are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, and specifically represented by strontium, aluminum and the like. Examples thereof include a metal layer, an alkali metal halide layer typified by potassium fluoride, an alkaline earth metal compound layer typified by magnesium fluoride, and an oxide layer typified by molybdenum oxide. The electron injection layer 3e according to the present invention is desirably a very thin film, and the layer thickness is preferably in the range of 1 nm to 10 μm although it depends on the material.

(3) Hole transport layer The hole transport layer 3b is made of a hole transport material having a function of transporting holes, and in a broad sense, the hole injection layer 3a and the electron blocking layer are also included in the hole transport layer 3b. . The hole transport layer 3b can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  Although the above-mentioned thing can be used as a positive hole transport material, It is preferable to use a porphyrin compound, an aromatic tertiary amine compound, and a styryl amine compound, especially an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole and also two fused aromatic rings described in US Pat. No. 5,061,569 In the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30868 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) in which three triphenylamine units described in Japanese Patent Publication are linked in a starburst type ) And the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. , Applied Physics Letters, 80 (2002), p. A so-called p-type hole transport material as described in 139 can also be used. In the present invention, it is preferable to use these materials because a more efficient light-emitting panel can be obtained.

  The hole transport layer 3b is formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. be able to. Although there is no restriction | limiting in particular about the layer thickness of the positive hole transport layer 3b, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer 3b may have a single layer structure made of one or more of the above materials.

  Also, the p-type can be enhanced by doping impurities into the material of the hole transport layer 3b. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  Thus, it is preferable to increase the p property of the hole transport layer 3b because a panel with lower power consumption can be manufactured.

(4) Electron Transport Layer The electron transport layer 3d is made of a material having a function of transporting electrons. In a broad sense, the electron transport layer 3e and a hole blocking layer (not shown) are also included in the electron transport layer 3d. The electron transport layer 3d can be provided as a single layer structure or a multi-layer structure.

  In the electron transport layer 3d having a single layer structure and the electron transport layer 3d having a multilayer structure, an electron transport material (also serving as a hole blocking material) constituting a layer portion adjacent to the light emitting layer 3c was injected from the cathode. What is necessary is just to have the function to transmit an electron to the light emitting layer 3c. As such a material, any one of conventionally known compounds can be selected and used. Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane, anthrone derivatives, and oxadiazole derivatives. Further, in the above oxadiazole derivative, a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group are also used as the material for the electron transport layer 3d. Can do. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced by Cu, Ca, Sn, Ga, or Pb can also be used as the material for the electron transport layer 3d.

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the material for the electron transport layer 3d. Further, a distyrylpyrazine derivative exemplified also as a material of the light emitting layer 3c can be used as a material of the electron transport layer 3d, and similarly to the hole injection layer 3a and the hole transport layer 3b, n-type -Si, n An inorganic semiconductor such as type-SiC can also be used as the material of the electron transport layer 3d.

  The electron transport layer 3d can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the layer thickness of 3 d of electron carrying layers, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer 3d may have a single layer structure composed of one or more of the above materials.

  In addition, the electron transport layer 3d can be doped with impurities to increase the n property. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like. Furthermore, it is preferable that the electron transport layer 3d contains potassium or a potassium compound. As the potassium compound, for example, potassium fluoride can be used. Thus, when the n property of the electron transport layer 3d is increased, a panel with lower power consumption can be manufactured.

  Further, as the material (electron transporting compound) of the electron transport layer 3d, the same material as that constituting the base layer 1a described above may be used. This is the same for the electron transport layer 3d that also serves as the electron injection layer 3e, and the same material as that for the base layer 1a described above may be used.

(5) Blocking layer (hole blocking layer, electron blocking layer)
The blocking layer may be further provided as the organic functional layer 3 in addition to the above functional layers. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL panel and its forefront of industrialization” (issued on November 30, 1998 by NTS Corporation). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has the function of the electron transport layer 3d in a broad sense. The hole blocking layer is made of a hole blocking material that has a function of transporting electrons but has a very small ability to transport holes, and recombines electrons and holes by blocking holes while transporting electrons. Probability can be improved. Moreover, the structure of the electron carrying layer 3d mentioned later can be used as a hole-blocking layer based on this invention as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer 3c.

  On the other hand, the electron blocking layer has the function of the hole transport layer 3b in a broad sense. The electron blocking layer is made of a material that has a function of transporting holes but has a very small ability to transport electrons, and improves the probability of recombination of electrons and holes by blocking electrons while transporting holes. be able to. Moreover, the structure of the positive hole transport layer 3b mentioned later can be used as an electron blocking layer as needed. The layer thickness of the hole blocking layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

<Second electrode (counter electrode)>
The second electrode 5a is an electrode film that functions as a cathode for supplying electrons to the organic functional layer 3, and a metal, an alloy, an organic or inorganic conductive compound, and a mixture thereof are used. Specifically, aluminum, silver, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, indium, lithium / aluminum mixture, rare earth metal, ITO, ZnO, TiO ₂ , An oxide semiconductor such as SnO ₂ can be given.

  The second electrode 5a can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering. The sheet resistance as the second electrode 5a is preferably several hundred Ω / □ or less, and the layer thickness is usually selected within a range of 5 nm to 5 μm, preferably within a range of 5 to 200 nm.

  In addition, when this organic EL panel 10 is a thing which takes out emitted light h also from the 2nd electrode 5a side, it selects the conductive material with favorable light transmittance among the conductive materials mentioned above, What is necessary is just to comprise the two electrodes 5a.

<Extraction electrode>
The extraction electrode 16 electrically connects the first electrode 1 and an external power source, and the material thereof is not particularly limited, and a known material can be suitably used. For example, a three-layer structure is used. A metal film such as a MAM electrode (Mo / Al · Nd alloy / Mo) made of can be used.

<Auxiliary electrode>
The auxiliary electrode 15 is provided for the purpose of reducing the resistance of the first electrode 1, and is provided in contact with the electrode layer 1 b of the first electrode 1. The material forming the auxiliary electrode 15 is preferably a metal having low resistance such as gold, platinum, silver, copper, or aluminum. Since these metals have low light transmittance, a pattern is formed in a range not affected by extraction of the emitted light h from the light extraction surface 13a.

  Examples of the method for forming the auxiliary electrode 15 include a vapor deposition method, a sputtering method, a printing method, an ink jet method, and an aerosol jet method. The line width of the auxiliary electrode 15 is preferably 50 μm or less from the viewpoint of the aperture ratio for extracting light, and the thickness of the auxiliary electrode 15 is preferably 1 μm or more from the viewpoint of conductivity.

<Encapsulant>
The sealing material 17 covers the organic EL panel 10 and may be a plate-shaped (film-shaped) sealing member that is fixed to the substrate 13 side by the adhesive 19. It may be a film. Such a sealing material 17 is provided in a state in which the terminal portions of the first electrode 1 and the second electrode 5 a in the organic EL panel 10 are exposed and at least the organic functional layer 3 is covered. Moreover, an electrode may be provided on the sealing material 17 so that the terminal portions of the first electrode 1 and the second electrode 5a of the organic EL panel 10 are electrically connected to this electrode.

  Specific examples of the plate-like (film-like) sealing material 17 include a glass substrate, a polymer substrate, a metal substrate, and the like. These substrate materials may be used in the form of a thin film. Examples of the glass substrate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer substrate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal substrate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

  In particular, since the panel can be thinned, a thin film-like polymer substrate or metal substrate can be preferably used as the sealing material 17.

Furthermore, the polymer substrate in the form of a film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less, JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a method conforming to the above is 1 × 10 ⁻³ g / (m ² · 24 h) or less. Is preferred.

  Further, the above substrate material may be processed into a concave plate shape and used as the sealing material 17. In this case, the substrate member described above is subjected to processing such as sandblasting and chemical etching to form a concave shape.

  Further, the adhesive 19 for fixing the plate-shaped sealing material 17 to the substrate 13 side is for sealing the organic EL panel 10 sandwiched between the sealing material 17 and the substrate 13. Used as a sealant. Specifically, such an adhesive 19 is a photocuring and thermosetting adhesive having a reactive vinyl group of an acrylic acid-based oligomer, a methacrylic acid-based oligomer, a moisture-curing type such as 2-cyanoacrylic acid ester, or the like. Can be mentioned.

  Moreover, as such an adhesive agent 19, the heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, the organic material which comprises the organic EL panel 10 may deteriorate by heat processing. For this reason, the adhesive 19 is preferably one that can be adhesively cured from room temperature to 80 ° C. A desiccant may be dispersed in the adhesive 19.

  Application | coating of the adhesive agent 19 to the adhesion part of the sealing material 17 and the board | substrate 13 may use a commercially available dispenser, and may print like screen printing.

  In addition, when a gap is formed between the plate-shaped sealing material 17, the substrate 13, and the adhesive 19, this gap has an inert gas such as nitrogen or argon or fluoride in the gas phase and the liquid phase. It is preferable to inject an inert liquid such as hydrocarbon or silicon oil. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

  On the other hand, when a sealing film is used as the sealing material 17, the organic functional layer 3 in the organic EL panel 10 is completely covered and the terminal portions of the first electrode 1 and the second electrode 5a in the organic EL panel 10 are exposed. Thus, a sealing film is provided on the substrate 13.

  Such a sealing film is configured using an inorganic material or an organic material. In particular, the material is composed of a material having a function of suppressing intrusion of a substance that causes deterioration of the organic functional layer 3 in the organic EL panel 10 such as moisture and oxygen. As such a material, for example, inorganic materials such as silicon oxide, silicon dioxide, and silicon nitride are used. Further, in order to improve the brittleness of the sealing film, a laminated structure may be formed using a film made of an organic material in addition to a film made of these inorganic materials.

  The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

<Protective film, protective plate>
Although illustration is omitted here, a protective film or a protective plate may be provided between the substrate 13 and the organic EL panel 10 and the sealing material 17. This protective film or protective plate is for mechanically protecting the organic EL panel 10, and in particular when the sealing material 17 is a sealing film, sufficient mechanical protection is provided for the organic EL panel 10. Therefore, it is preferable to provide such a protective film or protective plate.

  As the protective film or protective plate as described above, a glass plate, a polymer plate, a polymer film thinner than this, a metal plate, a metal film thinner than this, a polymer material film or a metal material film is applied. Among these, it is particularly preferable to use a polymer film from the viewpoint of light weight and thin panel.

≪Usage≫
A surface light emitting panel having a light emitting pattern manufactured by the method for manufacturing a surface light emitting panel according to the present invention has a light emitting pattern with excellent gradation characteristics and can be suitably used for a light emitting panel that displays an image having an intermediate gradation. . It can be suitably used for displaying images such as landscape images and human images as well as symbols, patterns, signs and the like having intermediate gradations.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

[Example 1]
<< Preparation of organic EL panel 1 >>
On a transparent resin substrate of 75 μm thick PET (Cosmo Shine A4300 manufactured by Toyobo Co., Ltd.), a nitrogen-containing compound N-1 represented by the following structural formula was formed in a thickness of 25 nm in a vacuum deposition apparatus, and then a mask was formed. A silver film having a thickness of 10 nm was used as an anode.

Furthermore, in each of the evaporation crucibles, HATCN as the hole injection material, α-NPD as the hole transport material, DPVBi as the host compound of the blue light emitting layer, FIr (pic) as the dopant of the blue light emitting layer, CBP as the host compound, Ir (ppy) ₃ as the dopant for the green light emitting layer, Ir (piq) ₃ as the dopant for the red light emitting layer, BAlq as the hole blocking material, Alq ₃ as the electron transporting material, and LiF as the electron injecting material The amount was filled. The vapor deposition crucible used was made of molybdenum or tungsten resistance heating material. Further, a Li dispenser (manufactured by SAES Getter Co., Ltd.) was used as an intermediate layer, and similarly prepared in a vapor deposition apparatus.

Structural formulas of N-1, HATCN, α-NPD, DPVBi, FIr (pic), CBP, Ir (ppy) ₃ , Ir (piq) ₃ , BAlq, and Alq ₃ are shown below.

<Formation of organic layer unit>
Next, after reducing the vacuum to 4 × 10 ⁻⁴ Pa, the current crucible for deposition containing HATCN was energized and heated, and HATCN was deposited on the ITO electrode side of the resin substrate at a deposition rate of 0.1 nm / second, A hole injection layer having a layer thickness of 15 nm was provided.

  Next, the deposition crucible containing α-NPD is energized and heated, and α-NPD is deposited on the hole injection layer at a deposition rate of 0.1 nm / second to provide a hole transport layer having a layer thickness of 25 nm. It was.

  Next, the deposition crucible containing 3% by mass of FIr (pic) and DPVBi is energized and heated, and FIr (pic) and DPVBi are deposited on the hole transport layer at a total deposition rate of 0.1 nm / second. Co-evaporated to provide a blue light emitting layer with a layer thickness of 15 nm.

  Next, the deposition crucible containing CBP was energized and heated, and CBP was deposited on the blue light emitting layer at a deposition rate of 0.1 nm / second to provide a first intermediate layer having a thickness of 5 nm.

Next, the deposition crucible containing 5% by mass of Ir (ppy) ₃ and CBP was energized and heated, and Ir (ppy) ₃ and CBP were mixed with the first intermediate layer at a total deposition rate of 0.1 nm / second. Co-evaporated on top, a green light emitting layer with a layer thickness of 10 nm was provided.

  Next, the deposition crucible containing CBP was energized and heated, and CBP was deposited on green light emission at a deposition rate of 0.1 nm / second to provide a second intermediate layer having a layer thickness of 5 nm.

Next, the deposition crucible containing 8% by mass of Ir (piq) ₃ and CBP is energized and heated, and Ir (piq) ₃ and CBP are added to the second intermediate layer at a total deposition rate of 0.1 nm / second. A red light emitting layer having a layer thickness of 10 nm was provided by co-evaporation.

  Next, the deposition crucible containing BAlq was energized and heated, and BAlq was deposited on the red light emitting layer at a deposition rate of 0.1 nm / second to provide a hole blocking layer having a layer thickness of 15 nm.

Subsequently, the crucible for vapor deposition containing Alq ₃ was energized and heated, and Alq ₃ was vapor-deposited on the hole blocking layer at a vapor deposition rate of 0.1 nm / second to provide an electron transport layer having a layer thickness of 30 nm.

<Vapor deposition of inorganic layer and electrode layer>
Further, the deposition crucible containing LiF was energized and heated, LiF was deposited on the electron transport layer at a deposition rate of 0.1 nm / second, and an electron injection layer having a layer thickness of 1 nm was provided. In this way, an organic functional layer was formed.

  Finally, aluminum was deposited on the electron injection layer to provide a cathode having a layer thickness of 110 nm.

  Then, the vapor deposition surface side was covered with an epoxy resin having a thickness of 300 μm to form a sealing material, further covered with an aluminum foil having a thickness of 12 μm to form a protective film, and then cured. All the operations so far were performed in a glove box (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more) in a nitrogen atmosphere without bringing the panel into contact with the atmosphere. Thus, the organic EL panel 1 was produced.

<< Preparation of organic EL panel 2 >>
Similar to the production of the organic EL panel 1, the steps up to <Formation of an organic layer unit> were carried out to produce a first organic unit.

  Subsequently, the evaporation source containing Li was energized and heated, Li was deposited on the electron transport layer at a deposition rate of 0.01 nm / second, and an intermediate layer having a layer thickness of 1 nm was provided on the first organic unit.

  Next, <deposition of the organic layer> was performed once again to produce a second organic unit on the Li intermediate layer.

  Subsequently, <formation of an inorganic layer and an electrode layer> was performed similarly to the production of the organic EL panel 1, and the organic EL panel 2 was produced in the same manner as the production of the organic EL panel 1 with a sealing and protective film.

<< Preparation of organic EL panel 3 >>
Similar to the production of the organic EL panel 1, the organic EL panel 3 was produced. However, the hole transport layer was 120 nm thick, and the electron transport layer was 90 nm thick.

[Measurement of voltage-luminescence luminance curve of organic EL panel]
With respect to the produced organic EL panels 1 to 3, voltage-luminescence luminance curves (VL curves) were obtained and the luminescence characteristics were evaluated. The light emission luminance was measured using a two-dimensional color luminance meter CS-2000 manufactured by Konica Minolta. Table 1 shows the respective driving voltages at which the light emission luminance is 300 cd / m ² and 3000 cd / m ² and the difference between them.

From Table 1, the organic EL panel 1 is the difference between the driving voltage emission luminance gives 300 cd / ^{m 2} and 3000 cd / ^{m 2} was as low as 0.8 V, the V-L curve, it can be seen the slope is steep.

<< Preparation of a surface emitting panel 1 having a light emitting pattern >>
The light emitting region size 93 × 93 mm of the produced organic EL panel 1 is irradiated with light for 7 hours by a UV tester (Iwasaki Electric Co., Ltd., SUV-W151: 100 mW / cm ² ) through a photo mask of a human image. Then, a human image was baked to produce an organic EL panel 1 having a light emission pattern.

<< Preparation of the surface emitting panels 2-4 provided with the light emission pattern >>
In the same manner as the production of the surface light emitting panel 1 provided with the light emitting pattern, the irradiation time and the organic EL panel are irradiated with light through a photomask in the same manner except that the irradiation time and the organic EL panel are changed as shown in Table 2, and the person image is printed. Surface emitting light amount panels 2 to 4 having a light emitting pattern were produced.

[Measurement of voltage change in the darkest part]
A voltage was applied to the obtained light emission pattern so that the brightest part (background) was 1000 cd / m ^2, and the luminance of the darkest part (hair) and the middle part (clothing) was measured. Further, a voltage was applied so that the darkest part of each image was 1000 cd / m ² , and a difference from a voltage giving 1000 cd / m ² before light irradiation was measured. In Table 2, this is shown as the amount of voltage change.

[Subjective evaluation]
The obtained human images were patterned, and the luminescent images of Examples 1 to 3 were emitted by applying voltage so that the brightest part (background) was 1000 cd / m ² and observed by 10 subjects A subjective evaluation experiment was conducted. The gradation characteristics of the luminescent image were evaluated as 5-level evaluation with 1 being preferable and 5 being preferable. The average rank of 10 subjects is shown in Table 2.

From Table 2, compared with the surface emitting panel 1 whose voltage change required to make it the same as the light emission luminance before light irradiation is 2.0 V, the surface emitting panels 2 to 4 having 1.0 V or less have a subjective evaluation score. It can be seen that a light emitting pattern surface emitting panel having high gradation characteristics and excellent gradation characteristics can be obtained. It can also be seen that the surface emitting panels 3 and 4 having a driving voltage difference of 1.0 V or more at which the light emission luminance is 300 cd / m ² and 3000 cd / m ² exhibit excellent gradation.

  A surface light emitting panel having a light emitting pattern manufactured by the method for manufacturing a surface light emitting panel according to the present invention has a light emitting pattern with excellent gradation characteristics and can be suitably used for a light emitting panel that displays an image having an intermediate gradation. .

DESCRIPTION OF SYMBOLS 1 1st electrode 1a Underlayer 1b Electrode layer 3 Organic functional layer 3a Hole injection layer 3b Hole transport layer 3c Light emitting layer 3d Electron transport layer 3e Electron injection layer 5a Second electrode 10 Organic EL panel 13 Substrate 13a Light extraction surface 15 Auxiliary electrode 16 Extraction electrode 17 Sealing material 19 Adhesive h Emitted light

Claims (3)

A method of manufacturing a surface light emitting panel having a light emitting pattern having at least a step of forming a light emitting pattern by irradiating light to an organic electroluminescence panel including one or a plurality of organic functional layers between at least a pair of electrodes,
In the step of forming the light emission pattern, the amount of voltage change necessary to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel the same as the light emission luminance before the light irradiation is 1.0 V or less. A method for manufacturing a surface light emitting panel having a light emission pattern, wherein the light emission condition is adjusted to form a light emission pattern. Light irradiation to an organic electroluminescence panel having a voltage-luminescence luminance curve in which the amount of voltage change required for the emission luminance of the organic electroluminescence panel to change from 300 cd / m ² to 3000 cd / m ² is 1.0 V or more A method of manufacturing a surface light emitting panel having a light emitting pattern according to claim 1, wherein a light emitting pattern is formed. A surface-emitting panel having a light-emitting pattern manufactured by the method for manufacturing a surface-emitting panel having a light-emitting pattern according to claim 1 or 2, wherein the organic electroluminescence panel has an emission luminance of 300 cd / d. The amount of voltage change required to change from m ² to 3000 cd / m ² is manufactured by irradiating an organic electroluminescence panel having a voltage-luminescence luminance curve with a voltage of 1.0 V or more to form a light emission pattern, And a light emission pattern characterized in that a change in voltage required to make the decrease in the light emission luminance of the light-irradiated organic electroluminescence panel equal to the light emission luminance before the light irradiation is 1.0 V or less. Equipped with a surface-emitting panel.

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