JP2006236920A - Organic el panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL panel capable of preventing occurrence of dripping of a hygroscopic member and of efficiently absorbing moisture. <P>SOLUTION: This organic EL panel 1 is composed by forming, on a translucent glass substrate 2, an organic EL element 9 with organic layers 5 each having at least a luminescent layer sandwiched between transparent electrodes 3 and a back electrode 6, and by mounting a sealing member 7 on the glass substrate 2 so as to cover the organic layers 5. The organic EL panel is so structured that the hygroscopic member 8 prepared by mixing a hygroscopic body 8a formed of a hygroscopic powder body, a binder 8b formed of a curable resin for retaining the hygroscopic body 8a on the surface of the sealing member 7, and a moisture permeable body 8c formed of a resin having a moisture permeability higher than that of the binder 8b is mounted to a surface of the sealing member 7 facing to the organic EL element 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, an organic EL element having an organic layer having at least a light emitting layer sandwiched between an anode and a cathode is formed on a translucent support substrate, and a sealing member is formed on the support substrate so as to cover the organic layer. The present invention relates to an organic EL panel provided in the above.

  As an organic EL panel, on a glass substrate (translucent support substrate) made of a glass material, a transparent electrode that becomes an anode by ITO (Indium Tin Oxide), a hole injection layer, a hole transport layer, a light emitting layer And an organic layer composed of an electron transport layer and a non-translucent back electrode such as aluminum (Al) serving as a cathode are sequentially laminated to form an organic EL element as a laminate, and a glass material covering the laminate A recess-shaped sealing member made of is hermetically provided on the glass substrate via an ultraviolet curable adhesive (photo-curable adhesive), and in an airtight space obtained by the glass substrate and the sealing member There is known one provided with a hygroscopic member, for example, disclosed in Patent Document 1.

Further, as an organic EL panel including a moisture absorbing member, the applicant of the present application has proposed a structure in which a moisture absorbing member having viscosity is provided on a surface of the sealing member facing the organic EL element in Patent Document 2. In such an organic EL panel, a cream-like moisture absorbing member made of a mixture of moisture-absorbing powder particles and an inert liquid is formed in a film shape on the surface of the sealing member facing the organic EL element. Is formed on the support substrate through an ultraviolet curable adhesive, and it is possible to prevent the occurrence of dark spots and a short circuit between both electrodes, and to dispose the moisture absorbing member. It is possible to simplify the sealing process including the process and improve productivity.
JP 2001-267066 A JP 2002-198170 A

  Although the organic EL panel provided with the cream-like moisture absorbing member as described above can exhibit a sufficient function as a moisture absorbing action, for example, when used as a vehicle display device such as a speedometer or an engine tachometer, The vehicle is housed in the case body of the vehicle display device at an attachment angle, and the environment in which the vehicle display device is used is subject to vibrations caused by running of the vehicle or high temperature (for example, about 85 ° C.). There is.

  In the organic EL panel used in such an environment, the moisture absorbing member provided in the sealing member has a non-uniform mixed state of the moisture absorbing powder and the inert liquid, and the vehicle display device A phenomenon occurs in which at least a part of the hygroscopic member flows and partially thickens on the lower end side of the inclined organic EL panel with the attachment angle to the bottom (hereinafter referred to as a liquid dripping portion).

  Therefore, particularly when the organic EL panel is downsized, when the clearance between the organic EL element and the hygroscopic member becomes small, the dripping portion interferes with the organic EL element, and the back electrode is particularly affected by the influence of vibration or the like. This causes damage to the side, causing dark spots, short-circuiting between both electrodes, and the like, resulting in a problem of shortening the lifetime of the organic EL panel.

  In addition, it is conceivable to use a solid moisture absorbing member so that no dripping portion is generated, but although moisture is absorbed well on the surface of the moisture absorbing member, it is difficult for moisture to penetrate into the moisture absorbing member. There is a problem that moisture absorption inside is difficult to perform and moisture absorption cannot be performed efficiently. Therefore, since a sufficient hygroscopic effect could not be exhibited, an organic EL panel provided with a hygroscopic member has been desired to solve this problem.

  Accordingly, an object of the present invention is made by paying attention to the above-described problems, and provides an organic EL panel that can prevent dripping of the moisture absorbing member and can efficiently absorb moisture. There is.

  According to the organic EL panel of the present invention, as described in claim 1, an organic EL element having an organic layer having at least a light emitting layer sandwiched between an anode and a cathode is formed on a translucent support substrate, An organic EL panel in which a sealing member is provided on the support substrate so as to cover a layer, a moisture absorbent body composed of moisture absorbent powder particles, and a curability for holding the moisture absorbent body on the surface of the sealing member A moisture absorbing member formed by mixing a binder made of resin and a moisture permeable body made of resin having higher moisture permeability than the binder is provided on a surface of the sealing member facing the organic EL element. And

  In addition, as described in claim 2, in the organic EL panel according to claim 1, the moisture-permeable body is formed in a short fiber shape.

  In addition, as described in claim 3, in the organic EL panel according to claim 1, the binder is made of a photocurable resin.

  In the present invention, an organic EL element having an organic layer having at least a light emitting layer sandwiched between an anode and a cathode is formed on a translucent support substrate, and a sealing member is formed on the support substrate so as to cover the organic layer. With respect to the organic EL panel provided in the above, it is possible to prevent dripping of the moisture absorbing member and perform efficient moisture absorption.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2, an organic EL panel 1 includes a glass substrate (support substrate) 2, a transparent electrode (anode) 3, an insulating layer 4, an organic layer 5, a back electrode (cathode) 6, and a sealing It is mainly composed of the member 7 and the hygroscopic member 8.

  The glass substrate 2 is a translucent support substrate having a rectangular shape.

  The transparent electrode 3 is formed of a conductive material such as ITO on the glass substrate 2 by means such as vapor deposition or sputtering, and is formed by pulling out from the Japanese-shaped display segment portion 3a and each segment. And the electrode part 3c provided at the terminal part of the lead part 3b. In addition, the electrode part 3c is concentrated on one side of the glass substrate 2.

  The insulating layer 4 is made of, for example, a polyimide-based insulating material, and is formed by means such as photolithography. The insulating layer 4 has a window portion 4a corresponding to the display segment portion 3a and a notch portion 4b corresponding to an electrode portion to be described later of the back electrode 6, and a transparent electrode for clearly displaying the outline of the light emitting region. A window portion 4a is formed so as to slightly overlap the peripheral edge portion of the display segment portion 3a, and is provided so as to cover the lead portion 3b in order to ensure insulation between the transparent electrode 3 and the back electrode 6.

  The organic layer 5 may have at least a light emitting layer, but in the embodiment of the present invention, the hole injection layer, the hole transport layer, the light emitting layer, and the electron transport layer are formed by means such as vapor deposition or sputtering. It is formed by sequentially laminating. The organic layer 5 is provided with a predetermined size so as to correspond to the place where the window portion 4 a is formed in the insulating layer 4.

  The back electrode 6 is formed of a metal conductive material such as aluminum (Al), aluminum lithium (Al: Li), or magnesium silver (Mg: Ag) by means such as vapor deposition or sputtering, Provided on the organic layer 6. The back electrode 6 is electrically connected to a lead portion 6 a provided on one side of the glass substrate 2 so as to be adjacent to each electrode portion 3 c in the transparent electrode 3. In addition, the electrode part 6b is provided in the terminal part of the lead part 6a, and the lead part 6a and the electrode part 6b are formed of the same material as the transparent electrode 3.

  As described above, the organic EL element 9 is obtained by sequentially laminating the transparent electrode 3, the insulating layer 4, the organic layer 5, and the back electrode 6 on the glass substrate 2 to form a laminate.

  The sealing member 7 is formed by forming a recess 7a in a flat plate member made of, for example, a glass material. The sealing member 7 and the glass 7 are formed by airtightly providing a supporting portion 7b formed so as to surround the concave portion 7a on the glass substrate 2 with an adhesive 10 of an ultraviolet curable epoxy resin, for example. An airtight space 11 for accommodating the organic layer 5 of the organic EL element 9 is formed with the substrate 2. The sealing member 7 is configured slightly smaller than the glass substrate 2 so that the electrode portion 3c of the transparent electrode 3 and the electrode portion 6b of the back electrode 6 are exposed to the outside.

  The moisture absorbing member 8 has a predetermined film thickness (for example, 1 mm) so as not to contact the organic EL element 9, the surface of the sealing member 7 facing the organic EL element 9, that is, the bottom surface of the recess 7 a of the sealing member 7. It is provided in the form of a film. The hygroscopic member 8 in the organic EL panel of the present invention includes a hygroscopic body 8a, a binder 8b, and a moisture permeable body 8c.

  The hygroscopic body 8a is made of a hygroscopic powder (drying agent) of 10 μm or less that physically or chemically absorbs moisture, such as zeolite, activated alumina, or silica gel. The hygroscopic body 8a preferably has no corrosiveness or deliquescence and has an excellent hygroscopic ability even under low humidity. In addition, a clay-type desiccant, allophane, barium oxide or strontium oxide is preferable. Alkali metal or alkaline earth metal oxides can also be used. Moreover, these materials can be used individually or in combination as the hygroscopic body 8a.

  The binder 8b is made of, for example, a solution-like photocurable resin. In this case, a cationic resin that can be cured at a low temperature in a short time and that hardly causes outgassing during curing can be suitably used. The binder 8b is applied to the opposing surface of the organic EL element 9 in the sealing member 7 (the bottom surface of the recess 7a) as the moisture absorbing member 8, and then cured by irradiating with ultraviolet rays, thereby holding the moisture absorbing member 8 in a predetermined shape. be able to. Note that a photocurable epoxy resin or a thermosetting resin can also be applied as the binder 8b.

  The moisture permeable body 8c is made of a resin having a higher moisture permeability than that of the binder 8b. For example, a material having a high moisture permeability such as a polyurethane resin, a polyvinyl alcohol resin, or a silicone resin can be applied. The moisture permeable body 8c has a shape of a short fiber that can be applied by a dispenser device. In this case, the average fiber diameter is 4 μm, and the length is larger than the average fiber diameter (for example, 5 μm). It is preferable that the shape has a length in a range up to the film thickness (for example, 1 mm) of the hygroscopic member 8 provided on the bottom surface of the recess 7a.

  The hygroscopic member 8 previously dry-processes the moisture-absorbing body 8a and the moisture-permeable body 8c, and mixes the moisture-absorbing body 8a and the moisture-permeable body 8c in a dry state in an inert atmosphere with a solution-like binder 8b. Is a mixture formed. The moisture absorbing member 8 is applied to the bottom surface of the concave portion 7a of the sealing member 7 with a predetermined film thickness by the dispenser device in a state where the short fiber-shaped moisture permeable body 8c and the moisture absorbing body 8a are stirred by means such as a mixer. The Further, the applied moisture absorbing member 8 can be held at a position where the binder 8b is cured by being irradiated with ultraviolet rays and the moisture absorbing body 8a and the moisture permeable body 8c are randomly diffused.

  The organic EL panel 1 includes an organic EL element 9 in which an organic layer 5 having at least a light emitting layer is sandwiched between a transparent electrode 3 and a back electrode 6 on a translucent glass substrate 2, and covers the organic layer 5. The organic EL panel 1 having the sealing member 7 provided on the glass substrate 2 as described above, and the moisture absorption body 8a made of moisture absorption powder particles and the curable property for holding the moisture absorption body 8a on the surface of the sealing member 7 A moisture absorbing member 8 formed by mixing a binder 8b made of resin and a moisture permeable body 8c made of a resin having higher moisture permeability than the binder 8b is provided on the surface of the sealing member 7 facing the organic EL element 9. .

  Therefore, even after the hygroscopic member 8 is cured, the moisture penetrating from the surface of the hygroscopic member 8 can be permeated so as to be dispersed to the inside through the short fibrous moisture permeable body 8c. Therefore, it is possible to efficiently absorb moisture using the hygroscopic body 8a inside the hygroscopic member 8, and to exhibit a sufficient hygroscopic action.

  Further, the moisture permeable body 8c is made of a resin having a moisture permeability higher than that of the binder 8b and is formed in a short fiber shape, so that the moisture permeable body 8 is dispersed efficiently while ensuring the moisture penetration distance. Since it can penetrate | infiltrate, the moisture absorption speed of the moisture absorption member 8 can be raised, and efficient moisture absorption can be performed.

  In addition, since the binder 8b is made of a photo-curable resin, the moisture absorbing member 8 can be cured in a short time at a low temperature, so that no dripping occurs without damaging the organic EL element 9. The moisture absorbing member 8 having a high moisture absorption capability can be held at a desired film thickness while preventing.

  In the embodiment of the present invention, the organic EL panel composed of the above-described components has been described as an example. However, the present invention is not limited to this, and the configuration and processing have the same effect. For example, the film thickness of the moisture absorbing member and the shape of the moisture absorbing body or moisture permeable body can be selected as appropriate according to the volume of the airtight space surrounded by the sealing member and the glass substrate. It is also conceivable that the moisture permeable material is applied with a minute particle and the moisture absorbing member is provided on the surface of the sealing member by a printing process.

  In addition, the process of irradiating the moisture absorbing member 8 with ultraviolet rays and the process of irradiating the adhesive 10 for bonding the sealing member 7 and the glass substrate 2 with ultraviolet rays can be performed simultaneously. The time required for processing can be reduced. Therefore, it is possible to reduce the possibility that moisture will be mixed before the airtight space 11 is formed after the organic EL elements 9 are stacked.

It is a perspective view which shows the organic electroluminescent panel of embodiment of this invention. It is a fragmentary sectional view of the organic electroluminescent panel of embodiment same as the above.

Explanation of symbols

1 Organic EL panel 2 Glass substrate (support substrate)
3 Transparent electrode (anode)
5 Organic layer 6 Back electrode (cathode)
7 Sealing member 8 Hygroscopic member 8a Hygroscopic body 8b Binder 8c Moisture permeable body 9 Organic EL element

Claims (3)

An organic EL element having at least an organic layer having a light emitting layer sandwiched between an anode and a cathode is formed on a translucent support substrate, and a sealing member is provided on the support substrate so as to cover the organic layer. An organic EL panel,
Mixing a moisture absorbent body made of moisture absorbent powder particles, a binder made of a curable resin that holds the moisture absorbent body on the surface of the sealing member, and a moisture permeable body made of a resin having a higher moisture permeability than the binder. An organic EL panel comprising: a moisture absorbing member formed on a surface of the sealing member facing the organic EL element.   The organic EL panel according to claim 1, wherein the moisture permeable body is formed in a short fiber shape. The organic EL panel according to claim 1, wherein the binder is made of a photocurable resin.

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