KR20080051489A - Display devices with metal organic compound and preparing method thereof - Google Patents

Abstract

A method for producing a light source, such as an electroluminescence device, by using an organometallic compound is provided to avoid a need for a vapor deposition step, solvent removing step and heat treatment step, thereby realizing excellent cost efficiency. A method for producing a light source comprises the steps of: mixing at least one resin acid selected from the resin acid group consisting of abietic acid, neoabietic acid, levopimaric acid, hydroabietic acid, pimaric acid, dextonic acid and a combination thereof, and at least one metallic compound selected from alkali metal compounds, alkaline earth metal compounds, titanium alkoxides, aluminum alkoxides and zirconium alkoxides to provide a mixture, and adding a phosphor thereto; and applying the resultant mixture onto an electrode.

Description

Method for manufacturing light source device using metal organic compound {Display devices with metal organic compound and preparing method

Inorganic EL or Organic EL displays are devices that display images or light using voltages applied between electrodes, and can be formed on plastic substrates or polymer resin films. It has excellent characteristics as a flexible display element and attracts attention as a next generation display element. In the electroluminescent display, the phosphor is excited by electrons injected from the electrode by a voltage applied to the electrode to emit light.

Electroluminescent display devices are largely divided into an inorganic electroluminescent type and an organic electroluminescent type according to a method and a material made thereof, and among them, an inorganic electroluminescent display device is further classified into a thin film type device and a distributed type device. As a method for manufacturing this, an electrode is first manufactured by vacuum deposition or a printing process on a base substrate, and a dielectric layer, an electron or a hole injection material is coated, and then a fluorescent layer is formed. Then, it is manufactured by applying dielectric, electron or hole injection material and forming electrode. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a phosphor mixture as a material for making an electroluminescent device and a method of simultaneously preparing an electron injection and fluorescent layer or a binder component that can be used as an electron injection layer. The viscosity of the very large and the component of the binder that acts as a binding is characterized in that it contains a metal organic compound to facilitate the injection of electrons or to increase the internal pressure. As a conventional method for manufacturing an electroluminescent device, an electrode is first manufactured by vacuum deposition or a printing process on a base substrate, and a dielectric, an electron, or a hole injection material is coated, and then a phosphor is formed. Then, it is manufactured by applying dielectric, electron or hole injection material and forming electrode. In the case of using a printing process, after each printing, a process of heat treatment is performed to remove the solvent present in the paste mixture, and in some cases, a process of heat treatment at a high temperature is performed to remove organic substances present in the phosphor layer. Therefore, the number of manufacturing processes is very large, the manufacturing cost is high, and the use of vacuum deposition requires expensive deposition equipment.

The present invention relates to a method of manufacturing an electroluminescent display device using the viscosity and thermal properties of an organic binder or a metal organic compound binder. More particularly, the present invention relates to a method of manufacturing an electroluminescent display device. It is related with the manufacturing method of the electroluminescent element which can be manufactured simply by apply | coating a mixture. In addition, the present invention includes a method of manufacturing an organic binder or a metal organic binder for manufacturing the electroluminescent display device. According to the present invention, there is no process of vacuum deposition using expensive deposition equipment in the process of forming a conventional dielectric layer or a fluorescent layer, and also a process of removing solvent and remaining organic matter present in the printing film even when the process is made through a printing process. The heat treatment process for elimination is also omitted. The present invention is also characterized in that the metal compound produced by reacting with the binder has a high pressure resistance, so that the manufacturing process is very simple by simultaneously insulating each layer. In addition, since the substrate can be manufactured without distinction, it can also be manufactured as a flexible display device.

The structure of the electroluminescent device in the present invention is formed of an electrode formed on a substrate, a layer which simultaneously serves as a dielectric and a fluorescent layer, and a transparent electrode. As the substrate, glass, alumina, plastic, a polymer film, a metal plate or a metal foil which can simultaneously serve as a metal electrode and a substrate can be used. The polymer layer may be formed on the electrode as a layer for preventing short circuit with the upper electrode.

In order to achieve the task of serving as a binder and coating on the particles, which are inorganic matters, in the present invention, a metal organic compound composition comprising a salt of metal ions or a metal alkoxide and an organic material which can act as a binder while reacting with the same. To provide.

Examples of the metal ions include salts containing alkali metal ions such as lithium, potassium, sodium, or the like, and alkoxide compounds thereof, alkali earth metal salts such as calcium, magnesium, and strontium, and alkoxide compounds thereof, salts such as titanium, aluminum, zirconium, and silicon. And one or more alkoxide compounds thereof and the like, and as an organic substance capable of bonding thereto, a resin acid such as abietic acid, neo-abietic acid, repopimaric acid, hydroabietic acid, fimaric acid, dextonic acid, etc. It is preferably at least one selected from the group. Or the mixture of the compositions may further comprise a binder. As the binder, it is possible to increase the adhesive strength by mixing polyethylcellulose, polyvinyl acetate, or the like, or to adjust the viscosity. Moreover, among the said compounds, especially the rosin resin which contains a lot of abies acid can also be used as it is.

The mixture is produced in the following order. At least one of resin acids such as abietic acid, neo-abietic acid, repopimaric acid, hydroavietic acid, fimaric acid and dextonic acid is selected, or a mixture of these rosin resins is dissolved in an organic solvent. In this case, the solvent may be used as alcohol, acetone, 2-methoxyethanol, diethyleneglycol mono-n-butyletheracetate (BCA), diethyleneglycol ethyletheracetate, and the like. The same solvent may be used. The mixture is reacted by mixing a compound of metal ions which can be used as a metal oxide precursor. At this time, the constituents of the reacted substance have a form of a salt of carboxylic acid in which a metal and a resin acid are bonded, but a large amount of organic component is contained and maintained in a liquid state. The following detailed embodiments are specified.

Example 1 Preparation of Phosphor Paste Containing Magnesium Metal Compound

100 ml of diethyleneglycol ethyletheracetate solvent is placed in a reactor and heated at 100 degrees or higher to remove moisture. Dissolve 150 g-400 g of abietic acid in the reactor in a heated solvent. At this time, if the amount of the aviate acid is too small, the desired viscosity cannot be obtained. If too much is added, mixing with the phosphor particles becomes difficult. The temperature of the mixture is lowered to 60 degrees or less, and magnesium methoxide Mg (OMe) (6-10 wt% in methanol, Aldrich Co.) is added in small portions to react. The amount of magnesium methoxide may be added from 0.01% to 24.6% of magnesium methoxide with respect to the weight of abiate depending on the desired breakdown voltage characteristics and the electroluminescence onset voltage. If too much magnesium is added, magnesium oxide will precipitate out, resulting in an unstable mixture. The reaction mixture is heated to 80 degrees or more to remove methanol generated after the reaction. At this time, if a large amount of methanol is left, it may cause a change in viscosity during binder application, which may prevent the formation of a uniform film. Phosphor powder is dispersed in the metal organic compound at high temperature. In this case, ZnS: Mn is used as a material for obtaining yellow-red light, ZnS: Tb or ZnS: TbOF is used to obtain green light, SrS: Cr, (SrS: Ce / ZnS) n, and Ca2Ga2S4: Ce for blue light. , Sr2Ga2S4: Ce and the like can be used. In addition, SrS: Ce / ZnS: Mn can be used as a white light-emitting body. The amount of powder is controlled according to the intended use, and 10% to 95% of the phosphor powder is added as a ratio to the weight of the binder. If you put too much, the adhesion is poor, if you put too little, the brightness is reduced.

In the above embodiment, at least one resin acid, such as neoavietic acid, repopimaric acid, hydroavietic acid, fimaric acid, and dextonic acid, may be selected and prepared in addition to the aviate resinic acid. Moreover, it can make using the rosin resin which is a mixture of the said resin acid.

Example 2 Preparation of Phosphor Paste Containing Lithium Metal Compound

The metal reactant of Example 1 is carried out in the same manner using lithium butoxide (lithium butoxide), it is added in the range of 0.01% to 21.2% relative to the weight of the resin acid.

Example 3 Preparation of Phosphor Paste Containing Titanium Metal Compound

As a metal reactant of Example 1, titanium iso-propoxide was used in the same manner, and the amount was added in a range of 0.01% to 43.4% based on the weight of the added abiete acid.

Example 4 Preparation of Phosphor Paste Containing Aluminum Metal Compound

The metal reactant of Example 1 is carried out in the same manner using aluminum isopropoxide (titanium iso-propoxide), it is added in the range of 0.01% to 32.1% by weight compared to the weight of abietic acid.

In addition to the above embodiments, metal compounds such as alkoxides of alkali metals such as sodium, potassium and cesium, or hydroxides thereof, and alkoxides of alkaline earth metals such as calcium, barium and strontium, zirconium alkoxides, silicon alkoxides, and the like are also produced by the same method. .

Example 5 Preparation of Phosphor Paste Containing Lithium and Titanium Metal Compounds

It is also possible to produce a composite metal organic compound containing at least one metal as the metal reactant of Example 1. A phosphor paste was prepared in the same manner as in Example 1 using lithium butoxide and titanium iso-propoxide, and the mixing ratio was considered in consideration of the low work function of lithium and the pressure resistance characteristics of titanium. It is controlled within the range of 0.01% to 43.4% relative to the weight of the abies acid.

Example 6 Preparation of Phosphor Paste Containing Magnesium and Titanium Metal Compounds

The phosphor paste was prepared in the same manner as in Example 1 using magnesium methoxide and titanium iso-propoxide as metal reactants of Example 1, and the low work function of magnesium and the internal pressure of titanium Taking into account the properties, the mixing ratio is adjusted within the range of 0.01% to 43.4% relative to the weight of the bieutic acid.

As in the above embodiment, the phosphor paste mixture of the metal organic compound is made by selecting one or more of alkali metal compounds, alkaline earth metal compounds, titanium alkoxides, aluminum alkoxides, zirconium alkoxides, and the like.

Example 7 Preparation of Fluorescent Layer Paste of Organic Electroluminescent Device

Produced in the same manner as in Example 1, as an phosphor, an organic fluorescent material such as anthracene, a phenyl group substituted cyclopentadiene, polyparaphenyl, poly thiophene derivatives, etc. are dispersed and produced according to a desired color.

Example 8 Fabrication of Inorganic Electroluminescent Device Containing Metal Organic Compound

After cleaning the glass substrate, an electrode is formed. The electrode forms an indium tin oxide (ITO) transparent electrode by a deposition method. In addition to glass, a ceramic substrate such as alumina, a plastic substrate, a polymer film, or a metal substrate may be used as the substrate. In the case of using a metal substrate, there is no need to perform electrode formation separately. In addition to the transparent electrode, the electrode may be formed by vacuum deposition or printing using aluminum, silver, nickel, copper, gold, or the like. An aluminum oxide film is formed within 50 nm to 200 nm by vacuum deposition as an insulating layer on the formed electrode to insulate the upper and lower plates. If deposited over 200nm, the dielectric constant is low, the overall brightness is reduced, and if the film thickness falls below 50nm, it does not function as an insulating film. At this time, an insulating oxide film conventionally used, such as titanium oxide, tantalum oxide, barium titanium product, silicon oxide, may be used as the insulating film material. Moreover, a polymeric material can also be used as an insulating layer. As the polymer material, a film of polyvinyl acetate, ethyl cellulose, polyimide, etc., which has insulation and adhesion effects, can be used. In addition, even if the insulating film is not formed, the component of the binder inherent in the phosphor paste can act as the insulating film, thereby removing the insulating film. The substrate formed up to the insulating film is heated to 80 degrees or more, and the phosphor paste made in Example 1 is applied. The coating method can be formed using a roll-type or a pen-type tool containing phosphor paste. If the mixture is warmed above 80 degrees, the viscosity increases and the curvature of the surface produced during application disappears. The upper plate coated with the transparent conductive film is bonded to the above phosphor layer. After cooling to room temperature, the viscosity decreases and is fixed again.

Example 9 Fabrication of Organic Electroluminescent Device Containing Metal Organic Compound

After cleaning the glass substrate, an electrode is formed. The electrode forms an indium tin oxide (ITO) transparent electrode by a deposition method. In addition to glass, a ceramic substrate such as alumina, a plastic substrate, a polymer film, or a metal substrate may be used as the substrate. The substrate formed up to the electrode is heated to 80 degrees or more, and the phosphor paste prepared in Example 7 is coated on the substrate. The coating method can be formed using a roll-type or a pen-type tool containing phosphor paste. Flattened by applied heat. The structure of the upper plate is formed of a transparent electrode or a metal electrode on a glass substrate, and a tetraarylbenzidine compound (triaryldiamine to triphenyldiamine: TPD), which is known as a hole transporter, is an aromatic tertiary amine and a hydrazone derivative. One or a mixture of carbazole derivatives, triazole derivatives, imidazole derivatives, and oxadiazole derivative polythiophene having an amino group is deposited at a thickness of 20 nm to 300 nm in consideration of electrical characteristics. The top plate made is bonded to the bottom plate. At this time, the lower plate is in a heating state and maintains a high viscosity state. After adhering the upper and lower plates, after cooling to room temperature, the upper and lower plates are fixed while decreasing viscosity.

The present invention allows the metal organic compound to act simultaneously as a binder, an insulating film, and a dielectric film, thereby simplifying the complicated process of the conventional electroluminescent device and reducing the cost. In addition, by using the high breakdown voltage characteristic of the composite compound of the metal organic compound and the binder, driving of a stable device is realized without breakdown even at high voltage. In addition, it is also possible to adjust the emission function by adjusting the work function according to the type of metal added to the composite compound. In addition, the resistance to moisture of the composite oxide has the effect of increasing the durability of the device. There is an effect that the adhesion is easily achieved by using a method of bonding using the characteristics of the viscosity change according to the heat of the composite compound. In addition, since there is no heat treatment of 200 degrees or more in the process of making the electroluminescent device, there is no stress between the multilayer films that may be caused by heat, and thus there is no breakage of the film due to heat. In addition, since there is no processing at high temperature, it is easy to manufacture a flexible display device using a polymer film.

Claims (10)

At least one resin acid and alkali metal compound selected from the group consisting of resin acids such as abietic acid, neo-abietic acid, repopimaric acid, hydroabietic acid, fimaric acid, dextonic acid, and rosin resins thereof. , A reaction product made by the method of Examples 1 to 7 by selecting at least one of an alkaline earth metal compound, titanium alkoxide, aluminum alkoxide, zirconium alkoxide and the like. A reaction product made by the method of Examples 1 to 7 by selecting at least one of an adhesive acid or a composite resin acid and an alkali metal compound, an alkali earth metal compound, titanium alkoxide, aluminum alkoxide, zirconium alkoxide and the like. Mixed paste of the reaction product of claim 1 or 2 and phosphor powder Phosphor paste containing at least one of alkali metals, alkaline earth metals, titanium, aluminum, zirconium, and silicon in the phosphor paste used for forming the fluorescent layer of the electroluminescent device. The electroluminescent phosphor paste of claim 4, wherein one or more metals selected from alkali metals, alkaline earth metals, titanium, aluminum, zirconium, and silicon in a component other than phosphors contain 0.0001% or more of the metal by weight of the organic material. Electroluminescent device made using claim 3 Method of making an electroluminescent device using the paste of claim 3 as in Example 8 Electroluminescent device having a very high viscosity and adhesiveness, not a solid state of the fluorescent layer of the electroluminescent device and the organic binder or metal organic mixture Electroluminescent device using a method of increasing the contact with the electrode by increasing the viscosity of the inner layer when applying heat Organic electroluminescent device composed of an electron transport layer and a phosphor layer made according to the method of Example 9