WO2012015122A1 - Moisture absorption filling material for organic light emitting diode, method for preparing same, and organic light emitting diode including same - Google Patents

Abstract

A moisture absorption filling material for organic light emitting diodes of the present invention has the form of a fibrous web, comprising an assembly of a plurality of fibers, wherein the fibers comprise a binder resin and moisture absorbing particles, and the moisture absorbing particles are fixed inside the fiber. The moisture absorption filling material for organic light emitting diodes of the present invention can enhance the moisture absorption efficiency by fixing the moisture absorbing particles inside the fiber.

Description

Hygroscopic filler for organic light emitting device, method of manufacturing the same and organic light emitting device comprising the same

The present invention relates to a moisture absorbing filler for an organic light emitting device, a method for manufacturing the same, and an organic light emitting device including the same. More specifically, the present invention relates to an organic light-emitting device for absorbing moisture, and an organic light-emitting device comprising the same, which can fix moisture-absorbing particles inside the fiber to further improve the moisture absorption efficiency.

The organic light emitting device (hereinafter, referred to as OLED) has a structure in which an organic EL layer, which is a thin film containing a fluorescent organic compound, is sandwiched between an anode and a cathode constituting a pair of electrodes, and excitons are formed by injecting holes and electrons into the thin film. It is a self-luminous element which produces | generates (exiton) and uses light emission (fluorescence and phosphorescence) when this exciton is inactivated.

When the organic light emitting diode is driven for a certain period of time, the organic film and the metal film, which are components of the organic light emitting diode, are gradually oxidized due to the penetration of moisture or generation of oxygen, carbon monoxide, moisture, and the like. There is a problem that the light emission characteristics are significantly degraded. In other words, the light emitting material reacts with moisture to be converted into non-advertised molecules to form dark spots, thereby lowering the luminous efficiency, and also lowering the charge transport ability, thereby increasing the impedance of the device. Due to the phenomenon that peeling from the organic taste occurs, the electron injection efficiency is drastically reduced and the life is gradually reduced.

As such, since the organic light emitting device is vulnerable to moisture and oxygen, a method of mounting a getter including a drying means capable of absorbing moisture in an encapsulation process to block moisture and oxygen is used in the device.

FIG. 1 schematically illustrates a sealing structure of an organic light emitting device equipped with a getter. As shown, a conventional organic light emitting device has a substrate 110, the organic light emitting unit 130 is formed on one surface of the substrate, the sealing cap 120 is coupled to the substrate to accommodate the organic light emitting unit Is formed. At least a portion of the sealing cap 120 is formed with a drying means 140 for absorbing moisture.

As the drying means, a hygroscopic powder such as calcium oxide (CaO) is placed in a water-permeable bag and sealed, or the pellet is compressed or the powder is mixed with a polymer binder to form a film. How to do it.

The method of using the filler in a moisture-permeable bag has a disadvantage that the thickness thereof is thicker than that of the film form, and the bag swelling phenomenon at high temperature and the filler powder fall off and fall onto the device. It is difficult and has a disadvantage of poor durability.

Recently, a getter is manufactured in a film form by mixing an inorganic filler and a polymer binder. In the case of such a film form, the configuration is simple, and there are advantages that can be manufactured in a thin film of several hundred micrometers or less, but the phenomenon of powder phase detachment from the getter occurs, and the moisture absorption rate is significantly slowed due to the polymer binder film. There are disadvantages.

In addition, although a method of filling silicone oil has been proposed, silicone oil is not only dehydrated to the OLED practical level even after dehydration for a long time, but also requires a structure for injecting a liquid into a display device and has a disadvantage of complicated process. .

In order to improve this problem, the present inventors have developed a hygroscopic filler having an improved hygroscopic efficiency by fixing the hygroscopic particles in the fiber (intro) constituting the web to form a hygroscopic filler (fibrous web).

An object of the present invention is to provide a moisture absorbing filler for an organic light emitting device excellent in the moisture absorption efficiency without the occurrence of dark spots and a method of manufacturing the same.

Another object of the present invention is to provide a moisture absorbing filler for an organic light emitting device excellent in moisture absorption rate and a method of manufacturing the same.

Still another object of the present invention is to provide a moisture absorbing filler for an organic light emitting device excellent in fixing power without leaving the moisture absorbent and a method of manufacturing the same.

Still another object of the present invention is to provide a hygroscopic filler for an organic light emitting device having a filler function and a method of manufacturing the same.

Another object of the present invention is to provide a hygroscopic filler for an organic light emitting device excellent in workability and easy manufacturing method and a method for manufacturing the same.

Still another object of the present invention is to provide a method of manufacturing an organic light emitting device, the thickness of which is easy to adjust.

Still another object of the present invention is to provide an organic light emitting device having improved light emission characteristics and lifespan by effectively preventing deterioration of constituent thin films of the device by applying the hygroscopic filler for organic light emitting devices.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

One aspect of the present invention relates to a hygroscopic filler for an organic light emitting device. The moisture absorbing filler for the organic light emitting device has a fibrous web form consisting of a plurality of fibers, the fiber comprises a binder resin and moisture absorbing particles, the moisture absorbing particles are fixed in the fiber (intro) It is characterized by.

In embodiments, the fibers may have an average diameter of about 0.1 to 200 μm.

In an embodiment, the hygroscopic filler for the organic light emitting device may have a porosity of about 5 to 95%, and a pore having an average diameter of about 0.1 to 100 μm.

The hygroscopic particles are hygroscopic; Hygroscopic particles treated with a polymer resin on the surface of the moisture absorbent; Or mixtures thereof and the like may be used, but is not necessarily limited thereto.

The hygroscopic agent is a molecular sieve zeolite, silica gel, carbonate, clay, metal oxide, metal hydroxide, alkaline earth metal oxide, sulfate, metal halide, perchlorate, organometal and organic / inorganic hybrid material capable of physical and chemical adsorption. This can be used. These can be used individually or in mixture of 2 or more types.

Hygroscopic particles treated with the polymer resin is a hygroscopic agent; And it may comprise a polymer resin formed in a continuous or discontinuous on the surface of the moisture absorbent. The polymer resin may be fixed at about 5 to 100% of the surface of the absorbent.

In an embodiment, the polymer resin may be fixed by forming a coating layer on the surface of the absorbent. In another embodiment, the polymer resin may be fixed by forming protrusions.

The moisture absorbent may have an average particle diameter range of about 0.01 to about 200 μm.

The binder may be the same or different components than the nonwoven fabric. In a specific embodiment, the binder is vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyester resin, polyolefin resin, (meth) acrylate resin, polycarbonate resin, acrylonitrile It is composed of components such as resins, cellulose acetates, epoxy resins, phenoxy resins, siloxane resins, sulfone resins, polyamide resins, polyurethane resins, polyvinyl resins, urethane acrylate resins, and fluorine resins. Can be. These can be used individually or in mixture of 2 or more types.

In embodiments, the binder may have a glass transition temperature of about −60 to 170 ° C., preferably about −60 to 80 ° C.

In embodiments, the fibers constituting the fibrous web may comprise about 40 to about 90 weight percent binder and about 10 to about 60 weight percent hygroscopic particles.

The moisture absorption filler for the organic light emitting device may have a thickness of about 5 to about 500㎛.

In a specific embodiment, the hygroscopic filler for the organic light emitting device may further include a coating layer.

In another embodiment, the moisture absorbing filler for the organic light emitting device may further include a sheet having pores. The voided sheet has a structure in contact with at least one side of the fibrous web.

The sheet having the voids may have a porosity of about 5 to about 95%. In embodiments, the sheet having the pores may be a moisture permeable sheet, and may be a nonwoven fabric, a woven fabric, a latex sheet, or a combination thereof.

The nonwoven fabric or woven fabric may be vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyester resin, polyolefin resin, (meth) acrylate resin, polycarbonate resin, acrylonitrile resin At least one resin, cellulose acetate, epoxy resin, phenoxy resin, siloxane resin, sulfone resin, polyamide resin, polyurethane resin, polyvinyl resin, urethane acrylate resin, and fluorine resin It consists of a component containing; The latex sheet may be composed of a component including one or more from the group consisting of polyurethane, polybutadiene, nitrile rubber, acrylic rubber and polysiloxane.

In one embodiment, the sheet having the pores may have a thickness of about 0.5 μm to about 500 μm.

In another embodiment, the sheet having the pores may be further formed with a coating layer. For example, the hygroscopic filler for the organic light emitting device may have a structure in which a hygroscopic filler having a fibrous web form, a sheet having pores, and a coating layer are sequentially stacked.

The moisture absorption filler for the organic light emitting diode may have a surface roughness Ra of more than about 0 and about 50 μm or less.

Another aspect of the present invention relates to a method of manufacturing a hygroscopic filler for an organic light emitting device. The method comprises electrospinning a mixed solution comprising about 10 to about 60 weight percent hygroscopic particles and about 40 to about 90 weight percent binder.

The mixed solution may further include a solvent.

In one embodiment, the mixed solution may be electrospun on at least one surface of the sheet having pores.

In another embodiment, the mixed solution may be directly electrospun into a sealing cap that houses the organic light emitting unit by combining with the substrate.

In another embodiment to prepare a first hygroscopic filler by electrospinning the mixed solution; And laminating a sheet having pores on at least one surface of the first hygroscopic filler. The sheet having the voids is attached to at least one surface of the first hygroscopic filler and laminated.

In embodiments, the electrospinning may be performed at a voltage of about 5 to about 45 kV at an interelectrode distance of about 5 to about 40 cm.

The electrospinning is characterized in that the temperature of the spinning zone is maintained at room temperature to about 80 ℃.

Another aspect of the invention relates to an organic light emitting device comprising the hygroscopic filler for the organic light emitting device. The organic light emitting device is a substrate; An organic light emitting unit formed on one surface of the substrate and including a first electrode, an organic light emitting layer, and a second electrode; A sealing cap coupled to the substrate to accommodate the organic light emitting unit; And drying means disposed in the sealing cap, wherein the drying means is a hygroscopic filler of the present invention.

The present invention does not generate dark spots, excellent moisture absorption efficiency, excellent moisture absorption speed, excellent absorbing force without leaving the absorbent, has a filler function, excellent workability and easy manufacturing method organic light emitting device It is possible to provide an organic light emitting device having improved light emission characteristics and lifespan by effectively preventing deterioration of constituent thin films by applying a moisture absorbing filler for the organic light emitting device and the organic light emitting device.

Figure 1 schematically shows a sealing structure of a conventional organic light emitting device.

Figure 2 is a schematic diagram of a hygroscopic filler for an organic light emitting device according to an embodiment of the present invention.

3 is a partially enlarged view of a portion A of FIG. 2.

4 (a) to 4 (c) are schematic cross-sectional views of the moisture absorbing particles treated with the polymer resin on the surface of the moisture absorbent.

Figure 5 is a schematic diagram applying the moisture-absorbing particles formed projections.

6 (a) and 6 (b) are schematic cross-sectional views of a sheet with voids.

7 (a) to (e) is a schematic cross-sectional view of the hygroscopic filler for an organic light emitting device according to another embodiment of the present invention.

8 is a schematic cross-sectional view of an organic EL device according to one embodiment of the present invention.

9 is a schematic cross-sectional view of an organic EL device according to another embodiment of the present invention.

10 is an optical micrograph result of the hygroscopic filler prepared in Example 1.

Hygroscopic filler for organic light emitting device

Hygroscopic filler for an organic light emitting device of the present invention has a fibrous web (fibrous web) form consisting of a plurality of aggregates of fibers, the fiber comprises a binder resin and moisture absorbing particles, the moisture absorbing particles in the fiber (intro) It is characterized in that fixed to.

2 is a view schematically showing a hygroscopic filler for an organic light emitting device of the present invention. As shown, the hygroscopic filler 100 for an organic light emitting device of the present invention has a fiber-like web (fibrous web) structure, the fibers 10 are entangled with each other, the pores are formed between these fibers (10) has a porous. The fibers may be regularly entangled or irregularly entangled.

The fibers may have an average diameter of about 0.1 to 200 μm, preferably about 1 to 100 μm, more preferably about 3 to 70 μm, and a fiber length of about 0.1 to 100 mm. By making the average diameter of the fiber have the above range, it is possible to fix the hygroscopic particles. In particular, in the several micrometer diameter region, the mechanical strength of the fibrous state can be imparted, and by forming a constant void, there is an advantage of preventing the delay of moisture absorption efficiency by the binder.

In addition, the hygroscopic filler having the fibrous web structure has a porosity of about 5 to 95%, preferably about 10 to 80%, and a void having an average diameter of about 0.1 to 100 μm. As such, the voids are formed, and gases such as moisture and oxygen can pass smoothly and react with the moisture absorbing particles. In addition, if the porosity is in the above range can have an excellent moisture absorption rate, there is an advantage that can act as a buffer between the moisture absorption layer and the device.

The moisture absorption filler for the organic light emitting device may have a thickness of about 5 to 500㎛.

3 is an enlarged schematic view of a portion A of FIG. 2. As shown in FIG. 3, the moisture absorbing particles 10a are fixed to the inside of the fiber 10 constituting the fibrous web.

In another embodiment, the hygroscopic filler for the organic light emitting device may further include a coating layer.

Hygroscopic Particles

Hygroscopic particles of the present invention may have an average particle diameter range of about 0.01 to about 200㎛. However, since the hygroscopic particles are fixed inside the fiber, the size of the hygroscopic particles is smaller than or equal to the diameter of the fiber.

The hygroscopic particles are hygroscopic; Hygroscopic particles treated with a polymer resin on the surface of the moisture absorbent; Or mixtures thereof and the like may be used, but is not necessarily limited thereto. These may be used in combination of one or more.

The hygroscopic agent is a molecular sieve zeolite, silica gel, carbonate, clay, metal oxide, metal hydroxide, alkaline earth metal oxide, sulfate, metal halide, perchlorate, organometal and organic / inorganic hybrid material capable of physical and chemical adsorption. This can be used. These can be used individually or in mixture of 2 or more types.

The carbonates include sodium carbonate, sodium bicarbonate and the like.

The metal oxides include lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), potassium oxide (K ₂ O), and the like, but are not necessarily limited thereto. Examples of the alkaline earth metal oxide include barium oxide (BaO), calcium oxide (CaO), magnesium oxide (MgO), and the like, but are not necessarily limited thereto. Examples of the metal hydroxides include calcium hydroxide and potassium hydroxide. Examples of the sulfate include lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), cobalt sulfate (CoSO ₄ ), gallium sulfate (Ga ₂ ( SO ₄ ) ₃ ), titanium sulfate (Ti (SO 4) ₂ ), or nickel sulfate (NiSO ₄ ). Examples of the metal halide include calcium chloride (CaCl ₂ ), magnesium chloride (MgCl ₂ ), strontium chloride (SrCl ₂ ), yttrium chloride (YCl ₂ ), copper chloride (CuCl ₂ ), cesium fluoride (CsF), and fluoride Tantalum (TaF ₅ ), niobium fluoride (NbF ₅ ), lithium bromide (LiBr), calcium bromide (CaBr ₃ ), cerium bromide (CeBr ₄ ), selenium bromide (SeBr ₂ ), vanadium bromide (VBr ₂ ), magnesium bromide (VBr ₂ ) MgBr ₂ ), barium iodide (BaI ₂ ) or magnesium iodide (MgI ₂ ), and examples of the perchlorate include barium perchlorate (Ba (ClO ₄ ) ₂ ) or magnesium perchlorate (Mg (ClO ₄ ) ₂ ). .

Among these are preferably metal oxides, metal hydroxides, alkaline earth metal oxides, sulfates or combinations thereof.

The moisture absorbent may have an average particle diameter range of about 0.01 to about 200 μm. Preferably from about 0.05 to about 100 μm, more preferably from about 0.1 to about 50 μm, most preferably from about 0.1 to about 25 μm. There is an advantage in the handling is easy without lowering the moisture absorption efficiency in the above range.

In the present invention, as the hygroscopic particles, the hygroscopic agent itself may be used as described above, or a hygroscopic particle treated with a polymer resin on the surface of the hygroscopic agent or a combination of the hygroscopic agent and the hygroscopic particles treated with the polymer surface may be used.

4 (a) to 4 (c) are schematic cross-sectional views of the moisture absorbing particles 10b in which the polymer resin is treated on the surface of the moisture absorbent. As shown, the hygroscopic particles (10b) surface-treated with a polymer resin is a hygroscopic (1); And a polymer resin (2) formed continuously or discontinuously on the surface of the moisture absorbent.

By fixing the polymer resin 2 on the surface of the moisture absorbent 1 as described above, dark spots are not formed even when the moisture absorbing particles 10b touch the element.

In a specific embodiment, the polymer resin 2 may be coated and fixed on the surface of the moisture absorbent 1. The polymer resin may be fixed to the entire coating or partially coated form of the absorbent surface. The polymer resin that can be used at this time may include a polymer of a crosslinkable monomer, a polymer of a vinyl monomer or a copolymer of a crosslinkable monomer and a vinyl monomer. The polymer of the crosslinkable monomer may be a polymer of one or more crosslinkable monomers, and the polymer of the vinyl monomer may be a polymer of one or more vinyl monomers. In addition, the copolymer of the crosslinkable monomer and the vinyl monomer may be a copolymer of at least one crosslinkable monomer and at least one vinyl monomer. These can be used individually or in mixture of 2 or more types. In an embodiment, the polymer resin may be a resin having a glass transition temperature of about -60 ° C to about 170 ° C. In the above range, there is no phenomenon in which the polymer resins aggregate together, and the polymer resin may be fixed to the surface of the absorbent. In an embodiment, when the polymer resin 2 is coated and fixed on the surface of the moisture absorbent 1, the polymer resin may be fixed at about 5 to 100% of the surface of the moisture absorbent.

The crosslinkable monomers include divinylbenzene, divinylsulphone, allyl (meth) acrylate, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, trially trimellitate; Ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (Meth) acrylate, pentaaryl tritol tetra (meth) acrylate, pentaaryl tritol tri (meth) acrylate, pentaaryl tritol di (dec) acrylate, trimethylolpropane tri (meth) acrylic Rate, ditrimethoxypropane tetra (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaeryryltritol penta (meth) acrylate , Glycerol tri (meth) acrylate and the like can be used, these can be prepared alone or by mixing two or more kinds.

The vinyl monomer is capable of radical polymerization, and specific examples thereof include aromatic vinyl monomers such as styrene, ethyl vinyl benzene, a-methyl styrene and m-chloromethyl styrene; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethyl (Meth) acrylate type monomers, such as hexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate; Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl ether, allyl butyl ether, and the like.

In one embodiment, the protruding fine particles may include a functional group having hard properties and having a strong bond and affinity with an inorganic material such as a metal. That is, the surface of the protruding microparticles is a thiol group, nucleophilic group and metal affinity functional group carboxyl group, hydroxy group, glycol group, aldehyde group, oxazole group, amine group, amide group, imide group, nitro group, nitrile group, liquor The thing processed by the phone machine etc. can be used.

As shown in FIG. 4 (a), the polymer resin 2 may be continuously formed on the surface of the moisture absorbent 1. As described above, when the polymer resin 2 is continuously fixed to the surface of the moisture absorbent 1, the polymer resin 2 has a form completely covering the surface of the polymer resin 2.

As shown in FIGS. 4B to 4C, the polymer resin 2 may be discontinuously formed on the surface of the moisture absorbent 1. As described above, when the polymer resin 2 is discontinuously fixed, as shown in FIG. 4 (b), a part of the surface of the moisture absorbent 1 is wrapped in the irregular shape of the polymer resin 2 or in FIG. 4 (c). As shown, the polymer resin 2 may be fixed to the surface of the moisture absorbent 1 in the form of particles to form protrusions.

Figure 5 is a schematic diagram applying the moisture-absorbing particles (10b) is formed projections.

As such, when the polymer resin 2 is fixed to the surface of the moisture absorbent 1 in the form of protrusions, the protrusions are about 0.1% to 99.9%, preferably about 1% to 99%, and more preferably, about the surface of the moisture absorbent. It can be fixed at about 5 to 90%. There is an advantage that can protect the device from the moisture absorbent without lowering the moisture absorption efficiency in the above range. Most preferably about 10-80%.

In embodiments, the shape of the protruding fine particles may be spherical, elliptical, hemispherical, columnar, triangular pyramid, square pyramidal, peanut, star, cluster, irregular, and the like, but is not necessarily limited thereto.

In addition, the protruding fine particles may have a single particle form or a core-shell form.

In a specific embodiment, the protruding microparticles are discontinuously fixed on the surface of the moisture absorbent at an average of 1 to 500 particles / μm ² , preferably 5 to 200 particles / μm ² , more preferably 10 to 100 particles / μm ² . Can be. There is an advantage that can protect the device without lowering the moisture absorption efficiency in the above range.

In embodiments, the size of the protruding fine particles may have a particle size of about 0.1 to about 50%, preferably about 0.5 to about 30% of the diameter of the moisture absorbent. This is because when the particle diameter of the projection-forming fine particles is less than about 0.1% of the particle size of the base material, the effect as a projection becomes ineffective, and when it exceeds about 50%, it becomes difficult to maintain the shape of the projection.

In one embodiment, the size of the protruding fine particles may have an average particle size range of about 0.005 to about 40 ㎛. Preferably the size of the protruding microparticles is about 0.05 to about 10 μm, more preferably about 0.01 to 5 μm, most preferably about 0.01 to about 1 μm. There is an advantage that can protect the device without deteriorating the performance of the absorbent in the above range. The size of the protruding particles is smaller than the size of the moisture absorbent (1), the porosity may be about 0.1 to 50%.

The protruding fine particles may be crosslinked. In this case, the degree of crosslinking may be about 0.5 to 50%, preferably about 1 to 30%, and more preferably about 2 to 20%. In the above range, the protruding microparticles formed on the surface of the absorbent are stable at the time of polymerization and may be well attached to the surface.

There is no particular limitation on the polymerization method of the protrusion-forming microparticles, but it may be prepared by emulsion polymerization, emulsion-free polymerization or dispersion polymerization. The process for producing the protruding microparticles is described in Korean Patent Nos. 772423 and 503343, and the present invention is incorporated by reference.

In another embodiment, the protruding microparticles are added to a vinyl monomer mixture comprising a crosslinkable monomer and a mixture of the oil-soluble initiator in an aqueous solution in which the surfactant is dissolved to prepare an aqueous emulsion, and the aqueous emulsion is a monodisperse seed particle dispersion. After addition to swelling, the swollen mixture can be prepared by polymerization.

The method of fixing the protruding microparticles to the surface of the moisture absorbent (1) may be performed by using a method such as a dry method using physical / mechanical friction, a dry method using physical / chemical friction, or a fixing method by wet treatment. It can stick to the surface. In the specific example, by using the method using a hybridization system (Nara Machinery Co.), the projection-forming fine particles can be fixed to the surface of the moisture absorbent (1).

As such, the protrusion-type moisture absorbing particles to which the protrusion-forming microparticles are fixed may have a weight ratio of the moisture absorbent 1 and the protrusion-forming microparticles to be about 99: 1 to 50:50, and preferably about 90:10 to 60:40. There is an advantage that can protect the device from the absorbent without deteriorating the performance of the absorbent in the above range.

bookbinder

The binder is a polyester resin such as vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyolefin resin, acrylate resin , (Meth) acrylate resin, polycarbonate resin, acrylonitrile resin, cellulose acetate, epoxy resin, phenoxy resin, siloxane resin, sulfone resin, polyamide-based resin including methacrylate resin Resins, polyurethane-based resins, polyvinyl-based resins, urethane acrylate-based resins, florin-based resins and the like can be used. These can be used individually or in mixture of 2 or more types. The binder may have a glass transition temperature of about −60 to 170 ° C., preferably about −60 to 80 ° C., more preferably about −60 to about 50 ° C. It is advantageous to adhere to the sealing cap without using an adhesive in the glass transition temperature range.

In embodiments, the fibers constituting the fibrous web may comprise about 40 to about 90 weight percent binder and about 10 to about 60 weight percent hygroscopic particles. It can have a high moisture absorption efficiency per unit area in the above range, there is an advantage having a film coating properties and physical properties to form a fibrous web (fibrous web) layer.

In another embodiment of the present invention, the moisture absorbing filler for the organic light emitting device may further include a sheet having pores. The voided sheet has a structure in contact with at least one side of the fibrous web.

The sheet having the pores has an average diameter of about 0.1 to 200 μm, preferably about 0.5 to 100 μm, more preferably about 1 to 50 μm, and a porosity of about 5 to 95%, preferably Is about 10 to 80%, more preferably about 20 to 70%. As such, the voids are formed, and gases such as moisture and oxygen can pass smoothly and react with the moisture absorbent. It may also have an excellent moisture absorption in the porosity of the above range.

In addition, the sheet having the pores may have a thickness of about 0.5㎛ to about 500㎛.

6 shows a schematic structure of a sheet 20 with voids used in the present invention. The sheet 20 may be formed of a nonwoven fabric or a woven fabric as shown in FIG. 6 (a), or may be a porous sheet such as latex 20c having voids 20b as shown in FIG. 6 (b). .

As shown in FIG. 6 (a), when the sheet 20 is formed of a nonwoven fabric or a woven fabric, the fibers 20a having an average diameter of about 0.1 to 200 μm may be regularly or irregularly entangled to have a web structure. These interfiber voids are formed and have a porosity. The fibers 20a may have an average diameter of about 0.1 to 200 μm, preferably about 0.5 to 100 μm, and more preferably about 0.5 to 50 μm. By having the average diameter of the fiber to have the above range, it is possible to impart a mechanical strength on the fiber, there is an advantage that can prevent the delay in moisture absorption efficiency by forming a constant void. In addition, the fiber length applied to the sheet having voids may be about 0.1 to 100 mm, preferably about 0.5 to 50 mm, more preferably about 1 to 30 mm.

Fibers constituting the nonwoven fabric or woven fabric include polyester acetate resins such as vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyethylene terephthalate resin, polybutylene terephthalate resin, and polyolefin resin , (Meth) acrylate resins including acrylate resin, methacrylate resin, polycarbonate resin, acrylonitrile resin, cellulose acetate, epoxy resin, phenoxy resin, siloxane resin, sulfone Resin, polyamide-based resin, polyurethane-based resin, polyvinyl-based resin, urethane acrylate-based resin, florin-based resin and the like can be used, these may be used alone or in combination of two or more.

In addition, the latex sheet may include components such as polyurethane, polybutadiene, nitrile rubber, acrylic rubber and polysiloxane. These may be used alone or in combination of two or more thereof.

7 (a) to 7 (b) are schematic cross-sectional views of a hygroscopic filler for an organic light emitting device further including a sheet having pores according to another embodiment of the present invention. The sheet 20 having the voids has a structure in contact with at least one surface of the hygroscopic filler 100 having a fibrous web structure of the present invention.

In another embodiment, as shown in FIG. 7C, the hygroscopic filler 100 may further include a coating layer 30. In the case of the laminated structure, the surface average roughness may be lowered and the modulus is low, thereby protecting the device from impact or stress.

In embodiments, the hygroscopic filler 100 having a fibrous web structure and the sheet 20 having pores may be stacked.

Although not shown in the drawings, the sheet 20 having pores on both sides of the hygroscopic filler 100 may be formed. In this case, the sheets 20 having voids may be the same or different from each other. In addition, the sheet 20 having voids may form a single layer or a plurality of layers.

In another embodiment, the sheet 20 having the pores may further have a coating layer 30. For example, as shown in Figure 7 (d) and (e), the hygroscopic filler for the organic light emitting device 100 is a hygroscopic filler 100 having a fibrous web form, the sheet 20 having a void and the coating layer 30 sequentially It may have a laminated structure, in the case of the laminated structure may be improved adhesive strength that can increase the adhesive strength between the sheet having a void and the substrate. In addition, although not shown in the drawings, in another embodiment, an adhesive layer may be formed between the hygroscopic filler having a fibrous web form and the sheet having pores.

Specific examples include polyester resins such as vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyolefin resin, and acryl. (Meth) acrylate resin, polycarbonate resin, acrylonitrile resin, cellulose acetate, epoxy resin, phenoxy resin, siloxane resin, sulfone resin, Polyamide resins, polyurethane resins, polyvinyl resins, urethane acrylate resins, florin resins and the like can be used. The coating layer may be a single layer or may form a plurality of layers, preferably a single layer. Also preferably, a resin that does not yield a residual total volatile matter (RTVM) content as measured by gas chromatography in the resin is more preferable in terms of protecting the device.

The coating layer may be porous or nonporous. The coating layer may have a thickness of about 0.1 to about 100 μm, preferably about 1 to about 50 μm. There is an advantage that can protect the device from the absorbent in the range that does not impair the moisture absorption efficiency in the above range.

Hygroscopic fillers for organic light emitting devices of the present invention are characterized in that the surface roughness (Ra) is greater than about 0 to about 50 μm or less, preferably greater than about 0 to about 1 μm or less, more preferably greater than about 0 to about 10 nm or less.

Method for manufacturing hygroscopic filler for organic light emitting device

The structure in which the hygroscopic particles 10a of the present invention are fixed inside the fibers of the fibrous web layer can be prepared by electrospinning a mixed solution in which the binder and the hygroscopic particles are mixed. At this time, the mixed solution may be composed of about 40 to 90% by weight of the binder and about 10 to 60% by weight of the hygroscopic particles. The binder serves to easily fix the hygroscopic particles in the above range, there is an advantage that can form a stable fibrous web (fibrous web) by adjusting the viscosity of the spinning mixture solution.

In embodiments, the mixed solution may further include a solvent. The solvent is ethanol, methanol, propanol, butanol, isopropanol. Acetone, methyl ethyl ketone, propylene glycol, 1-methoxy 2-propanol (PGM), isopropyl cellulose (IPC), methyl cellosolve (MC), ethyl cellosolve (EC) and the like can be used, but are not necessarily limited thereto. It is not. These can be used individually or in mixture of 2 or more types. The solvent may be used in an amount of about 100 to about 2000 parts by weight, and preferably about 200 to about 1000 parts by weight, based on 100 parts by weight of the hygroscopic particles.

Electrospinning of the present invention is a spinning solution containing a moisture-absorbing particle and a binder as a spinning solution, and the filament discharged from the spinning nozzle using the spinning solution is spun onto the heating plate at the lower end to keep the temperature of the spinning zone in a predetermined range. The fibrous web can be formed into a hygroscopic film by fibrating a binder including hygroscopic particles while keeping the solvent volatilized. At this time, by adjusting the distance and voltage between the electrode and the solid content of the discharge liquid, it is possible to control the fiber form such as the fibrous web form and porosity. In embodiments, the distance between the electrodes during the electrospinning is about 5 to about 40 cm, preferably about 10 to about 30 cm. The voltage can also be carried out at about 5 to about 45 kV, preferably about 15 to about 25 kV. When it is in the above range, it is possible to obtain a fibrous web form and porosity of the present invention.

In addition, the temperature of the spinning zone may be maintained at a temperature at which the solvent mixed at room temperature to about 80 ° C. is volatilized. In the above range, as the solvent is volatilized at the same time as the electrospinning, the fibrous web is formed to sufficiently remove the solvent remaining in the fibrous web.

The hygroscopic filler for the organic light emitting device prepared by electrospinning as described above may have a thickness of about 5 to about 500 ㎛, preferably about 10 to about 200 ㎛.

In another embodiment, the mixed solution may be electrospun on at least one side of the sheet having pores. As such, when spinning the mixed solution directly on the sheet having the pores, it is integrated with the sheet having the pores so that a separate bonding process is not required.

In another embodiment, the mixed solution may be electrospun and then adhered to the sheet having pores. In an embodiment, the mixed solution is electrospun to prepare a first hygroscopic filler; In addition, the moisture absorbent filler may be manufactured by stacking sheets having voids on at least one surface of the first moisture absorbent filler. The sheet having the voids is attached to at least one surface of the first hygroscopic filler and laminated. In one embodiment, the sheet having pores may be attached to both sides of the hygroscopic filler. In another embodiment, the hygroscopic filler having the fibrous web structure of the present invention may be attached to both sides of the sheet having voids.

In another embodiment, the mixed solution may be directly electrospun into a sealing cap that houses the organic light emitting unit by combining with the substrate. In this case, there is an advantage of not requiring a separate attachment process between the sealing cap and the hygroscopic filler.

Organic light emitting device

Another aspect of the invention relates to an organic light emitting device comprising the hygroscopic filler. 8 is a schematic cross-sectional view of an organic light emitting diode according to an embodiment of the present invention. The organic light emitting device is a substrate (11); An organic light emitting unit 13 formed on one surface of the substrate and including a first electrode, an organic light emitting layer, and a second electrode; A sealing cap 12 coupled to the substrate to accommodate the organic light emitting unit; And drying means disposed in the sealing cap, and the drying means may use the moisture absorbing filler 100 for the organic light emitting device.

The position at which the hygroscopic filler 100 for the organic light emitting device is fixed to the sealing cap 12 is not limited to the drawings, and may be fixed to at least a portion of the sealing cap 12. In another embodiment, the moisture absorbing filler 100 for the organic light emitting device may be interposed between the organic light emitting unit 13 and the sealing cap 12.

The hygroscopic filler 100 for the organic light emitting device may be fixed to the sealing cap 12 by a method such as adhesion. In this case, the organic light emitting device and the hygroscopic filler may be spaced apart at regular intervals and filled with an inert gas therebetween. In another embodiment, the hygroscopic filler 100 for the organic light emitting device may be fixed to the sealing cap 12 by electrospinning directly to the sealing cap 12 without an adhesive or the like.

In another embodiment, the moisture absorbing filler 100 for the organic light emitting diode may be in direct contact with the organic light emitting unit 13. 9 is a schematic cross-sectional view of an organic light emitting device according to the embodiment. Alternatively, the moisture absorbing filler 100 for the organic light emitting device may contact the organic light emitting part 13 while filling the inside of the sealing cap 12.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Example 1

70 parts by weight of an acrylic resin (manufactured by Cheil Industries) and 30 parts by weight of a metal oxide (CaO), which is a hygroscopic particle, containing butylacrylate as a main component and having a low glass transition temperature, and 100 parts by weight of methyl ethyl ketone as a solvent In addition, a spinning solution was prepared. The electrospinning device was electrospun at 5 Kv using an electrospinning apparatus to prepare a hygroscopic filler for the organic light emitting device to a thickness of 50 μm. Fiber diameter and porosity of the hygroscopic fillers were measured using an optical microscope, and the photograph is shown in FIG. 10. The average fiber diameter was 30 µm and the porosity was 50%.

The prepared hygroscopic filler was fixed to the sealing cap and a hygroscopic filler was fixed to the sealing cap was prepared. Separately, an organic light emitting part including a first electrode, an organic light emitting layer, and a second electrode is formed on a glass substrate, and a sealing cap having a hygroscopic filler fixed thereto is disposed to accommodate the organic light emitting part, and then sealed on a substrate to emit organic light The device was manufactured.

Example 2

The same procedure as in Example 1 was conducted except that the voltage was changed to 10 kV during electrospinning.

Example 3

The same procedure as in Example 1 was carried out except that the voltage was changed to 15 kV during electrospinning.

Example 4

The same procedure as in Example 1 was conducted except that the voltage was changed to 20 kV during electrospinning.

Example 5

The polymerization was carried out in the same manner as in Example 3, except that a urethane acrylate (manufactured by Cheil Industries) having polyol and multi-isocyanate as a binder was polymerized.

Example 6

The same procedure as in Example 3 was carried out except for using a florin-based resin (Solvay company name solef 1008) as a binder.

Comparative Example 1

The mixed solution of Example 1 was cast in the drying condition of 80 ℃ to prepare a hygroscopic material having a thickness of 50 ㎛ was carried out in the same manner as in Example 1.

Comparative Example 2

The mixed solution of Example 5 was cast in the drying condition of 80 ℃ to prepare a hygroscopic material of 50 ㎛ thickness was carried out in the same manner as in Example 5.

Comparative Example 3

The mixed solution of Example 6 was cast in a dry condition at 150 ° C. to prepare a hygroscopic material having a thickness of 50 μm, and the same procedure as in Example 6 was carried out.

Table 1 Binder 70% Hygroscopic Particles 30% Film manufacturing method Example 1 Acrylic system CaO Electrospinning 5 kv Example 2 Acrylic system CaO Electrospinning 10 kv Example 3 Acrylic system CaO Electrospinning 15 kv Example 4 Acrylic system CaO Electrospinning 20 kv Example 5 Urethane Acrylic System CaO Electrospinning 15 kv Example 6 Florin CaO Electrospinning 15 kv Comparative Example 1 Acrylic system CaO Solvent casting drying @ 80 ℃ Comparative Example 2 Urethane Acrylic System CaO Solvent casting drying @ 80 ℃ Comparative Example 3 Florin CaO Solvent casting drying @ 150 ℃

The moisture absorption efficiency and tack characteristics of the organic light emitting diodes manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 were measured by the following methods, and the results are shown in Table 2 below.

(1) Moisture absorption efficiency: Max moisture absorption efficiency evaluation according to the weight increase after 200 hours at 85 ℃, 80% moisture absorption conditions.

(2) Tack: It is the ability to adhere to the adherend in a short time with very light force and is evaluated by ball tack. Ball speed was measured at 0.08 mm / sec.

(3) Surface roughness Ra: It measured with the non-contact surface roughness measuring instrument (ZYGO company NV6300).

TABLE 2 Fiber Average Diameter (㎛) Porosity (%) Hygroscopic efficiency (%) Tack [gF] Surface Roughness (㎛) Example 1 30 50 13 307 15 Example 2 20 45 13 295 8 Example 3 15 40 15 290 6 Example 4 13 40 15 292 5 Example 5 15 40 16 62 5 Example 6 13 40 14 5 4 Comparative Example 1 - 0 12 311 0.1 Comparative Example 2 - 0 13 65 0.2 Comparative Example 3 - 0 10 4 0.1

As shown in Table 2, in the case of the hygroscopic filler prepared by electrospinning, it has excellent moisture absorption efficiency and moisture absorption rate, and it can be seen that it has a value similar to the tack characteristic of the film. In addition, the hygroscopic filler according to the present invention was found to have superior hygroscopic efficiency compared to Comparative Examples 1-3.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings and tables, the present invention is not limited to the above embodiments, but may be manufactured in various forms, and the present invention is commonly known in the art. Those skilled in the art can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

The moisture absorbent filler for the organic light emitting device according to the present invention does not generate dark spots, has excellent hygroscopic efficiency, hygroscopic speed and hygroscopic fixing force, has a filler function, excellent workability, and prevents deterioration of constituent thin films of the device. In addition, it can be usefully used when manufacturing an organic light emitting device having improved light emission characteristics and lifespan characteristics.

Claims (33)

The organic light emitting device has a fibrous web form consisting of a plurality of fibers (fibrous web), the fiber comprises a binder resin and moisture absorbing particles, the moisture absorbing particles are fixed in the fiber (intro) Hygroscopic filler. The hygroscopic filler for an organic light emitting device according to claim 1, wherein the fiber has an average diameter of about 0.1 to 200 µm. The hygroscopic filler for organic light emitting diodes according to claim 1, wherein the hygroscopic filler for organic light emitting diodes has a porosity of about 5 to 95% and an average diameter of about 0.1 to 100 μm. According to claim 1, wherein the moisture absorbing particles are moisture absorbents; Hygroscopic particles treated with a polymer resin on the surface of the moisture absorbent; Or a hygroscopic filler for an organic light emitting device, characterized in that a mixture thereof. The method of claim 4, wherein the hygroscopic agent is capable of molecular sieve zeolite, silica gel, carbonate, clay, metal oxide, metal hydroxide, alkaline earth metal oxide, sulfate, metal halide, perchlorate, organometal and physical and chemical adsorption. Hygroscopic filler for organic light emitting device, characterized in that it comprises at least one from the group consisting of organic-inorganic hybrid materials. The method of claim 4, wherein the hygroscopic particles treated with the polymer resin is a hygroscopic agent; And a polymer resin formed continuously or discontinuously on the surface of the moisture absorbent. 7. The hygroscopic filler according to claim 6, wherein the polymer resin is fixed at about 5 to 100% of the surface of the moisture absorbent. The hygroscopic filler for an organic light emitting device according to claim 6, wherein the polymer resin is fixed by forming a coating layer on the surface of the moisture absorbent or by forming protrusion-forming fine particles. 5. The hygroscopic filler according to claim 4, wherein the hygroscopic agent has an average particle diameter range of about 0.01 to about 200 mu m. The method of claim 1, wherein the binder is vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyester resin, polyolefin resin, (meth) acrylate resin, polycarbonate resin, Consisting of acrylonitrile resin, cellulose acetate, epoxy resin, phenoxy resin, siloxane resin, sulfone resin, polyamide resin, polyurethane resin, polyvinyl resin, urethane acrylate resin, florin resin Hygroscopic filler for an organic light-emitting device comprising at least one from the group. The method of claim 1, wherein the binder is a moisture absorption filler for an organic light emitting device, characterized in that the glass transition temperature of about -60 ~ 170 ℃. The method of claim 1, wherein the binder is a moisture absorption filler for an organic light emitting device, characterized in that the glass transition temperature of about -60 ~ 80 ℃. The hygroscopic filler for an organic light emitting device according to claim 1, wherein the fiber comprises about 40 to 90 wt% of the binder and about 10 to 60 wt% of the hygroscopic particles. The moisture absorption filler of claim 1, wherein the moisture absorption filler for organic light emitting diodes has a thickness of about 5 to about 500 μm. The hygroscopic filler for an organic light emitting device according to claim 1, wherein the hygroscopic filler for an organic light emitting device further comprises a coating layer. The organic light emitting diode of claim 1, wherein the moisture absorbing filler for the organic light emitting diode further comprises a sheet having pores, and the sheet having pores contacts at least one surface of the fibrous web. Hygroscopic filler. 17. The hygroscopic filler for an organic light emitting device according to claim 16, wherein the sheet having pores has a porosity of about 5 to about 95%. 17. The hygroscopic filler for organic light emitting elements according to claim 16, wherein the sheet having voids is a moisture permeable sheet, and a nonwoven fabric, a woven fabric, a latex sheet, or a combination thereof. 19. The method of claim 18, wherein the nonwoven fabric or woven fabric is a vinyl acetate resin (PVAc) resin, polyvinyl pyrrolidone (PVP) resin, polyester resin, polyolefin resin, (meth) acrylate resin, polycarbonate resin Resin, acrylonitrile resin, cellulose acetate, epoxy resin, phenoxy resin, siloxane resin, sulfone resin, polyamide resin, polyurethane resin, polyvinyl resin, urethane acrylate resin, florin resin It consists of a component containing one or more from the group consisting of; The latex sheet is a hygroscopic filler for an organic light-emitting device, characterized in that made of a component containing at least one from the group consisting of polyurethane, polybutadiene, nitrile rubber, acrylic rubber and polysiloxane. 17. The sheet of claim 16, wherein the sheet having voids has a thickness of about 0.5 microns to about 500 microns. Hygroscopic filler for organic light emitting device. The hygroscopic filler for an organic light emitting device according to claim 16, wherein the sheet having pores is further formed with a coating layer. The hygroscopic filler for an organic light emitting diode according to claim 16, wherein the hygroscopic filler for the organic light emitting diode has a structure in which a hygroscopic filler having a fibrous web form, a sheet having pores, and a coating layer are sequentially stacked. 17. The hygroscopic filler for an organic light emitting diode according to claim 16, wherein the moisture absorbent filler for the organic light emitting diode has a surface roughness Ra of greater than about 0 and about 50 µm or less. Electrospinning a mixed solution comprising about 10 to about 60% by weight of the hygroscopic particles and about 40 to about 90% by weight of the binder comprising the step of electrospinning. The method of claim 24, wherein the mixed solution further comprises a solvent. 25. The method of claim 24, wherein the mixed solution is electrospun on at least one surface of the sheet having voids. 25. The method of claim 24, wherein the mixed solution is directly bonded to a substrate and electrospun into a sealing cap for accommodating an organic light emitting unit. 25. The method of claim 24, further comprising: electrospinning the mixed solution to prepare a first hygroscopic filler; And The method of manufacturing a hygroscopic filler for an organic light-emitting device further comprising the step of laminating a sheet having a void on at least one surface of the first hygroscopic filler. 25. The method of claim 24, wherein the sheet having pores is attached to at least one surface of the first moisture absorbing filler and laminated. 25. The method of claim 24, wherein the electrospinning is performed at a voltage of about 5 to about 45 kV at an interelectrode distance of about 5 to about 40 cm. 25. The method of claim 24, wherein the electrospinning maintains the temperature of the spinning zone at room temperature to about 80 ° C. An organic light emitting device comprising the hygroscopic filler for organic light emitting device according to any one of claims 1 to 23. Board; An organic light emitting unit formed on one surface of the substrate and including a first electrode, an organic light emitting layer, and a second electrode; A sealing cap coupled to the substrate to accommodate the organic light emitting unit; And It includes a drying means disposed in the sealing cap, The drying means is an organic light-emitting device, characterized in that the hygroscopic filler according to any one of claims 1 to 23.

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