KR102024258B1 - Pressure sensitive adheisve and flexible organic light emitting diode display device - Google Patents

Abstract

The present application relates to a pressure-sensitive adhesive and a flexible organic light emitting diode display including the same. The pressure-sensitive adhesive of the present application can increase the light extraction efficiency while reducing the thickness and structure of the flexible organic light emitting diode display.

Description

Pressure sensitive adheisve and flexible organic light emitting diode display device

The present application relates to an adhesive and a flexible organic light emitting diode display device including the same.

In recent years, the display field for visually expressing electrical information signals has been rapidly developed in the age of full-scale informatization, and flat panel display devices having excellent performance of thinning, light weight, and low power consumption have been developed and used.

Liquid crystal display devices (LCDs) and organic light emitting diode (OLED) displays have been widely used among flat panel displays.

In particular, the organic light emitting diode display device has a merit of enabling a light weight and thinness as compared to a liquid crystal display device requiring a backlight unit which is a separate light source by using a self-light emitting device.

In addition, the organic light emitting diode display device has a relatively superior viewing angle and contrast ratio compared to the liquid crystal display device, has a fast response speed, consumes low power consumption, enables direct low voltage driving, and thus makes it easy to manufacture and design a driving circuit. Have In addition, since the internal components are solid, they are resistant to external shocks, and have a wide range of use temperature ranges.

The organic light emitting diode display device having these advantages is being studied to be applied to a wider use area such as a desktop computer monitor and a wall-mounted television as well as a portable computer, and in particular, a study for large area to have a larger display area has been studied. It is actively underway.

The organic light emitting diode display device includes a display panel including an organic light emitting layer for self-emission, and an organic light emitting diode including first and second electrodes for emitting the organic light emitting layer.

In the organic light emitting diode display, when a voltage is applied to the first electrode and the second electrode, electrons and holes injected from the first electrode and the second electrode, respectively, are combined within the organic light emitting layer to generate excitons. Exciton uses the principle of emitting light falling from the excited state to the ground state.

Recently, as the interest in flexible display devices increases, the demand for a technique of using a flexible substrate for an organic light emitting diode display device is increasing. However, when the flexible substrate is applied to the organic light emitting diode display device, the difference in refractive index between the organic light emitting diode device and the flexible substrate and the adhesive causes total reflection when light passes through the material at a specific angle of incidence, thereby reducing the light efficiency of the device. There is a problem. In order to solve this problem, a technique for disposing a light extracting film inside or outside the organic light emitting diode device is known, but such a technique is complicated because a separate light extracting film must be manufactured and attached, and the thickness of the final device is increased. There is a drawback to thickening.

Republic of Korea Patent Publication No. 2015-0078333

The present application provides a flexible organic light emitting diode display including a pressure-sensitive adhesive that can increase the light extraction efficiency and at the same time thinning the structure of the flexible organic light emitting diode display.

The present application relates to an adhesive. The adhesive of the present application may be used in a flexible organic light emitting diode display. Exemplary pressure-sensitive adhesive of the present application may include a pressure-sensitive adhesive resin and organic-inorganic composite particles. The organic-inorganic composite particles may be organic beads containing inorganic nanoparticles. In one example, the transmittance may be 80% or more. In one example, the pressure-sensitive adhesive may have a haze of 70% or more.

Since the pressure-sensitive adhesive of the present application has a high transmittance, a high refractive index, and a high haze, the difference in refractive index between the organic light emitting diode device and the flexible substrate can be reduced to reduce the total reflection occurring in the refractive index gap between the layers, and light scattering by the beads The effect can increase the light extraction efficiency. In addition, the present application is a technology to increase the refractive index and haze without lowering the transmittance of the pressure-sensitive adhesive instead of using a separate light extraction film for the organic light emitting diode device, it is possible to increase the light extraction efficiency while at the same time thinning and simplifying the structure of the device Can be.

Hereinafter, the adhesive of this application is demonstrated concretely.

In one example, the organic-inorganic composite particles may be present in a dispersed state in the adhesive resin. The organic-inorganic composite particles have an advantage of having similar interfacial properties with the organic medium and lower density than the inorganic particles, so that the organic-inorganic composite particles can be easily dispersed in the organic bead medium. Therefore, when using the organic-inorganic composite particles can further improve the light extraction performance.

In one example, the adhesive resin may be an adhesive resin known to be used in a flexible organic light emitting diode display. As adhesive resin, the group which consists of an acrylate resin, a silicone resin, a rubber resin, a styrene resin, an epoxy resin polyolefin resin, a polyoxyalkylene resin, a polyester resin, a polyvinyl chloride resin, a polycarbonate resin, and a polyamide resin, for example One or more types selected from can be used. According to the exemplary embodiment of the present application, an acrylate resin may be used as the adhesive resin, and more specifically, butyl acrylate, isobornyl acrylate, phenoxyethyl acrylate, and 2 Copolymers of 2-hydroxyethyl acrylate may be used.

In one example, the organic-inorganic composite particles may be included in a proportion of 10 to 50 parts by weight based on 100 parts by weight of the adhesive resin. When the content ratio is satisfied, the light extraction efficiency of the pressure-sensitive adhesive can be effectively increased.

4 exemplarily shows a structure of the organic-inorganic composite particles. The organic-inorganic composite particles may be organic beads 2 containing inorganic nanoparticles 1. In the present specification, an organic bead may mean a spherical particle made of an organic material. The inorganic nanoparticles may be present in a dispersed state in the organic beads.

In one example, the organic-inorganic composite particles may include beads including a crosslinked polymer of a vinyl monomer and inorganic nanoparticles in the crosslinked structure of the beads.

In one example, the organic-inorganic composite particles can be prepared by adding a monomer mixture to the aqueous dispersion, dispersing it in the form of droplets, homogenizing and reacting. As the aqueous dispersion, for example, water, sodium phosphate, calcium chloride and hydrochloric acid may be mixed and stirred to form an aqueous dispersion in which calcium phosphate crystals are precipitated. The monomer mixture may include, for example, a vinyl monomer, a crosslinking agent, a charge control agent, an inorganic nanoparticle dispersion and an initiator. Styrene may be used as the vinyl monomer, for example, divinylbenzene may be used as the crosslinking agent, and a styrene-acrylic polymer charge controlling agent including a sulfonic acid group may be used as the charge control agent. Azonitrile-based initiators can be used.

In one example, the organic-inorganic composite particles can be high refractive index particles. As an example, the refractive index of the organic-inorganic composite particles with respect to light of 400 nm to 800 nm wavelength may be 1.4 to 2.0. Since the organic-inorganic composite particles increase the refractive index of the pressure-sensitive adhesive, it is possible to improve the light extraction efficiency due to the light scattering effect with the total reflection decrease. The refractive index of the organic-inorganic composite particles can be controlled by adjusting the content of the inorganic nanoparticles in the organic beads.

 Unless stated otherwise in the present specification, the refractive index may be a value measured for light having a wavelength of about 400 nm to 800 nm, for example, about 632.8 nm, using a known refractive index measuring apparatus such as a Prism Coupler SPA-4000 apparatus. have.

In one example, the particle size of the organic-inorganic composite particles may be 1㎛ to 5㎛. When the particle diameter of the organic-inorganic composite particles satisfies the above range, the haze can be increased without reducing the transmittance of the pressure-sensitive adhesive, so that the light extraction efficiency can be effectively increased. The light scattering effect due to the particle size increases the light extraction efficiency, and the haze of the pressure-sensitive adhesive may be increased due to the light scattering effect.

In one example, the inorganic nanoparticles can be high refractive index particles. As one example, the inorganic nanoparticles may have a refractive index of 2.0 to 2.5 for light having a wavelength of 400 nm to 800 nm. Since the inorganic nanoparticles increase the refractive index of the adhesive, the light extraction efficiency can be improved due to the total reflection reduction effect.

In one example, the particle diameter of the inorganic nanoparticles may be 1 nm or more and 50 nm or less. When the particle diameter of the inorganic nanoparticles satisfies the above range, the dispersion stability may be secured in the organic beads to effectively increase the light extraction efficiency.

In one example, a metal oxide may be used as the inorganic nanoparticles. Examples of the inorganic nanoparticles include silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), iron oxide (FeO ₃ ), zinc oxide (ZnO), At least one metal selected from the group consisting of magnesium oxide (MgO), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), lithium oxide (LiO ₂ ), silver oxide (AgO), and antimony oxide (Sb ₂ O ₃ ) Oxides can be used. According to one embodiment of the present application, zirconium oxide (ZrO ₂ ) may be used.

In one example, the organic beads may be used one or more selected from the group consisting of polystyrene and polymethyl methacrylate.

In one example, the content of the inorganic nanoparticles in the organic-inorganic composite particles may be 10% by weight to 30% by weight. If the content ratio satisfies this, the light extraction efficiency can be effectively increased. According to an embodiment of the present application, the content of the inorganic nanoparticles in the organic-inorganic composite particles may be about 20 wt%.

The thickness of the pressure-sensitive adhesive may be appropriately selected in consideration of the purpose of the present application. In one example, the adhesive may have a thickness of 15 μm to 25 μm. When the thickness of the adhesive satisfies the above range, the light extraction efficiency can be effectively increased. When the thickness of the pressure-sensitive adhesive is too thin, it is difficult to manufacture and the light scattering effect is reduced, and when the thickness of the pressure-sensitive adhesive is too thick, the transmittance of the pressure-sensitive adhesive may be reduced.

The pressure-sensitive adhesive of the present application may exhibit high refractive index as well as high transmittance and high haze.

In one example, the transmittance of the pressure-sensitive adhesive may be at least 80%, specifically at least 85%, more specifically at least 88%. In the present specification, the transmittance may mean transmittance for light having a wavelength of 400 nm to 800 nm. As one example, in the present specification, the transmittance may mean a transmittance for light of any wavelength of 400 nm to 800 nm, or an average transmittance for light of 400 nm to 800 nm. As such, when the pressure-sensitive adhesive exhibits high transmittance, the light efficiency can be further increased.

In one example, the haze of the pressure sensitive adhesive may be at least 70%, specifically at least 80%, more specifically at 90%. As such, when the pressure-sensitive adhesive exhibits high haze, light extraction efficiency may be effectively increased due to an increase in scattering effects.

The present application also relates to a flexible organic light emitting diode display. An exemplary display device of the present application may include the adhesive, the flexible substrate, and the organic light emitting diode device.

1 exemplarily shows a display device of a first embodiment of the present application. According to FIG. 1, the pressure-sensitive adhesive 10 may be present on one surface of the flexible substrate 20, and the organic light emitting diode device 30 may be disposed on the opposite side of the pressure-sensitive adhesive of the flexible substrate.

As the flexible substrate, a flexible substrate known to be used in a flexible display device may be used. As the flexible substrate, a substrate containing at least one member selected from the group consisting of polyether sulfone, polyethylene naphthalate, polyethylene terephthalate, polycarbonate and polyimide can be used.

The refractive index of light of 400 nm to 800 nm of the flexible substrate may be 1.45 to 1.75. The pressure-sensitive adhesive of the present application may increase light extraction efficiency by reducing total reflection by reducing a difference in refractive index with the flexible substrate.

The organic light emitting diode device may include an organic light emitting layer between the first and second electrodes disposed opposite to each other and the first and second electrodes. In the following description, the electrode adjacent to the flexible substrate is referred to as a first electrode, and the opposite electrode is referred to as a second electrode.

In one example, when the first electrode is a transparent electrode and the second electrode is a reflective electrode, a lower light emitting device in which light generated in the organic light emitting layer is radiated to the substrate side may be implemented.

The organic light emitting layer can be formed using, for example, various fluorescent or phosphorescent organic materials known in the art. Examples of the material of the light emitting layer include tris (4-methyl-8-quinolinolate) aluminum (III) (tris (4-methyl-8-quinolinolate) aluminum (III)) (Alg3), 4-MAlq3 or Gaq3. Alq series materials, C-545T (C ₂₆ H ₂₆ N ₂ O ₂ S), DSA-amine, TBSA, BTP, PAP-NPA, Spiro-FPA, Ph ₃ Si (PhTDAOXD), PPCP (1,2,3 Cyclopenadiene derivatives such as, 4,5-pentaphenyl-1,3-cyclopentadiene), DPVBi (4,4'-bis (2,2'-diphenylyinyl) -1,1'-biphenyl), distyryl Benzene or derivatives thereof or DCJTB (4- (Dicyanomethylene) -2-tert-butyl-6- (1,1,7,7, tetramethyljulolidyl-9-enyl) -4H-pyran), DDP, AAAP, NPAMLI,; Or Firpic, m-Firpic, N-Firpic, bon ₂ Ir (acac), (C ₆ ) ₂ Ir (acac), bt ₂ Ir (acac), dp ₂ Ir (acac), bzq ₂ Ir (acac), bo _{2 Ir (acac), F 2} Ir (bpy), F 2 Ir (acac), op 2 Ir (acac), ppy 2 Ir (acac), tpy 2 Ir (acac), FIrppy (fac-tris [2- ( 4,5'-difluorophenyl) pyridine-C'2, N] iridium (III)) or Btp ₂ Ir (acac) (bis (2- (2'-benzo [4,5-a] thienyl) pyridinato-N, Phosphorescent materials such as C3 ') iridium (acetylactonate)) and the like can be exemplified, but is not limited thereto. The light emitting layer includes the material as a host, and further includes perylene, distyrylbiphenyl, DPT, quinacridone, rubrene, BTX, ABTX, or DCJTB. It may have a host-dopant system including a dopant.

The organic light emitting diode device may be formed in various structures further including various other functional layers known in the art as long as the organic light emitting diode is included, and the functional layer may include an electron injection layer, a hole blocking layer, an electron transport layer, A hole transport layer, a hole injection layer, etc. can be illustrated.

In one example, a pixel driving layer may be formed on the flexible substrate, and an organic light emitting diode device may be formed on the pixel driving layer. The pixel driving layer may include, for example, a driving thin film transistor, a switching thin film transistor, and a color filter layer.

The display device may further include an encapsulation structure as needed. The encapsulation structure may be a protective structure to prevent foreign substances such as moisture or oxygen from flowing into the organic light emitting layer of the organic light emitting diode device. The encapsulation structure may be, for example, a can such as a glass can or a metal can, or a film covering the entire surface of the organic light emitting layer.

The display device may further include a barrier layer. As used herein, the term "barrier layer" may mean a layer having a function of preventing permeation of oxygen, moisture, nitrogen oxides, sulfur oxides, or ozone in the atmosphere. The barrier layer is not particularly limited as long as it has the above function, and may be appropriately selected depending on the intended use.

The barrier layer may be present between the organic light emitting diode device and the flexible substrate or on an opposite side of the flexible substrate of the pressure-sensitive adhesive. When present between the organic light emitting diode device and the flexible substrate may be referred to as the inner barrier layer, and when present on the opposite side of the flexible substrate of the pressure-sensitive adhesive may be referred to as the outer barrier layer.

2 exemplarily shows a display device of the second embodiment of the present application. As illustrated in FIG. 2, the display device may sequentially include an adhesive 10, a flexible substrate 20, an inner barrier layer 40, and an organic light emitting diode device 30. 3 exemplarily shows a display device of a third embodiment of the present application. As shown in FIG. 3, the display device may sequentially include an outer barrier layer 50, an adhesive 10, a flexible substrate 20, an inner barrier layer 40, and an organic light emitting diode device 30.

The material of the barrier layer may be a material having a function of preventing substances entering the device, such as moisture and oxygen, from degrading the device. Specific examples of the barrier layer include specific examples of the barrier layer include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni; TiO, TiO ₂ , Ti ₃ O _{3 ,} Al ₂ O ₃ , MgO, SiO, SiO ₂ , GeO, NiO, CaO, BaO, Fe ₂ O ₃ , Y2O ₃ , ZrO ₂ , Nb ₂ O ₃ and CeO ₂ and Metal oxides such as; Metal nitrides such as SiN; Metal oxynitrides such as SiON; Metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ ; Polyethylene, polypropylene, polymethylmethacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, or chlorotrifluoroethylene and dichlorodifluoroethylene Copolymers; Copolymers obtained by copolymerizing a comonomer mixture comprising at least one comonomer with tetrafluoroethylene; Fluorine-containing copolymer which has a cyclic structure in a copolymer main chain; An absorbent material having an absorption rate of 1% or more; And a moisture proof material having an absorption coefficient of 0.1% or less.

In one example, the barrier layer may be a single layer structure or a multilayer structure. For example, the barrier layer may be an Al ₂ O ₃ layer and It may be a multilayer structure in which the TiO ₂ layers are sequentially stacked.

When the pressure-sensitive adhesive of the present application is applied to the flexible organic light emitting diode display device, any other component or a method of configuring the device is not particularly limited, and any material or method known in the art may be used as long as the pressure-sensitive adhesive is applied. Can be employed.

The present application provides a flexible organic light emitting diode display including a pressure-sensitive adhesive that can increase the light extraction efficiency and at the same time thinning the structure of the flexible organic light emitting diode display.

1 is a schematic view of a display device of a first embodiment of the present application.
2 is a schematic view of a display device of a second embodiment of the present application.
3 is a schematic view of a display device of a third embodiment of the present application.
4 is a cross-sectional schematic diagram of organic-inorganic composite particles.

Hereinafter, the present application will be described in more detail through examples according to the present application and comparative examples not according to the present application, but the scope of the present application is not limited to the examples given below.

Measurement example  1. Transmittance Measurement

The transmittance of light with a wavelength of 400 nm to 800 nm was measured using a Nippon denshoku 400 device.

Measurement example  2 Haze  Measure

Haze was measured using a Nippon denshoku 400 instrument.

Evaluation example  1 Quantum Efficiency Assessment

Quantum efficiency was measured using an integrating hemisphere apparatus of OTSUKA Corporation.

Example  One

Preparation of Organic-Inorganic Composite Particles

<Organic inorganic particle manufacturing method>

1. Preparation of Aqueous Dispersion: 200 g of water was mixed with 6.5 g of sodium phosphate, 25.2 g of 1M calcium chloride, and 0.8 g of 35% hydrochloric acid, and stirred for 20 minutes to prepare an aqueous dispersion in which calcium phosphate crystals were precipitated.

2. Preparation of monomer mixture: 28.6 g of styrene, 3.2 g of divinyl benzene as crosslinking agent, 1.2 g of styrene-acrylic polymer charge control agent containing sulfonic acid group having a weight average molecular weight of 16,500, 30% zirconia dispersion ( Mix 27 g of ZA10, CIK NANOTEK). 0.6 g of azo nitrile initiator (Azo nitrile: V65, Waco Chemical) was added and stirred for 5 minutes to prepare a monomer mixture.

3. Homogenization step: The monomer mixture was added to the aqueous dispersion, and a homogenizer was used to apply shear force at a rate of 13,000 rpm to homogenize the monomer mixture in the aqueous dispersion by dispersing it in the form of fine droplets.

4. Particle preparation: Through the homogenization, the monomer mixture dispersed in the aqueous dispersion in the form of fine droplets was reacted at 60 ° C. for 15 hours while stirring at 400 rpm with a paddle type stirrer to finally prepare a slurry of polymer particles in which zirconia was dispersed. It was.

Particle Wash and Dry

1. Washing step: pH was adjusted to 2 or less by adding hydrochloric acid to a slurry of polymer particles in which zirconia was dispersed, and calcium phosphate was dissolved. Then, after the water was removed using a filtration apparatus, distilled water twice as much as the total weight was added and diluted, and the water was repeatedly removed to remove calcium phosphate and other impurities on the surface of the polymer particles.

2. Drying step: After finally removing moisture through filtration, it was placed in a vacuum oven and vacuum dried at room temperature for 48 hours.

3. Measurement of Polymer Particle Size: The prepared polymer particles have a particle size of 1 µm to 5 µm and a zirconia content of 20%. The particle size was measured using SEM and OM, and the zirconia content was measured using TGA.

Preparation of pressure sensitive adhesive

The prepared composite particles were dispersed in MEK (Methyl Ethyl Ketone) solution by stirring and sonication. The dispersed multi-particle dispersion solution was mixed with a copolymer of butyl acrylate (BA), isobornyl acrylate (IBOA), phenoxyethyl acrylate (PEA) and 2-hydroxyethyl acrylate as an adhesive resin. After stirring and sonication for one day, it was sufficiently dispersed in the adhesive resin. The pressure-sensitive adhesive resin solution was coated on a release-treated polyethylene terephthalate (PET) film by a bar coating method, dried at 120 ° C. for 2 minutes in an oven, and immediately after the release PET film was laminated to prepare an adhesive. The prepared pressure-sensitive adhesive was about 20 μm, and the content of the organic-inorganic composite particles in the pressure-sensitive adhesive was 15 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive resin.

Flexible  Fabrication of Organic Light Emitting Diode Display

A display device including the prepared adhesive 10, a plastic substrate 20 having a refractive index of 1.75 with respect to light having a wavelength of 400 nm to 800 nm, and a known organic light emitting diode device 30 having the structure shown in FIG. It was.

Example  2

In preparing the adhesive, the display device was manufactured in the same manner as in Example 1, except that the content of the organic-inorganic composite particles was changed to 30 parts by weight based on 100 parts by weight of the adhesive resin.

Comparative example  One

A display device was manufactured in the same manner as in Example 1, except that the organic-inorganic composite particles were not added when the pressure-sensitive adhesive was prepared.

For Examples 1 to 2 and Comparative Example 1, the transmittance and haze of the pressure-sensitive adhesive were measured, the quantum efficiency of the display device was evaluated, and the results are shown in Table 1 below.

Example 1 Example 2 Comparative Example 1 adhesive Transmittance (%) 88.97 85.20 91.65 Haze (%) 76.71 90.68 0.42 Quantum Efficiency (%) 54.8 55.8 52.0

1: inorganic nanoparticles
2: organic beads
10; adhesive
20: flexible substrate
30: organic light emitting diode
40: inner barrier layer
50: outer barrier layer

Claims (19)

And an organic-inorganic composite particle having an adhesive resin and a particle size of 1 to 5 µm, wherein the organic-inorganic composite particle is an organic bead containing inorganic nanoparticles, and has a transmittance of 80% or more and a haze of 70% or more.
The pressure sensitive adhesive of claim 1, wherein the pressure sensitive adhesive is applied to a flexible organic light emitting diode display.
The pressure-sensitive adhesive of claim 1, wherein the organic-inorganic composite particles are present in a dispersed state in the pressure-sensitive adhesive resin.
The method of claim 1, wherein the adhesive resin is an acrylate resin, a silicone resin, a rubber resin, a styrene resin, an epoxy resin polyolefin resin, a polyoxyalkylene resin, a polyester resin, a polyvinyl chloride resin, poly Pressure-sensitive adhesive containing at least one member selected from the group consisting of carbonate resins and polyamide resins.
The pressure-sensitive adhesive according to claim 1, wherein the organic-inorganic composite particles are contained in a ratio of 10 parts by weight to 50 parts by weight with respect to 100 parts by weight of the adhesive resin.
The pressure-sensitive adhesive of claim 1, wherein the organic-inorganic composite particles have a refractive index of 1.4 to 2.0 with respect to light having a wavelength of 400 nm to 800 nm.
delete The pressure-sensitive adhesive of claim 1, wherein the inorganic nanoparticles have a refractive index of 2.0 to 2.5 with respect to light having a wavelength of 400 nm to 800 nm.
The method of claim 1, wherein the inorganic nanoparticles are silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), iron oxide (FeO ₃ ), zinc oxide (ZnO). ), Magnesium oxide (MgO), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), lithium oxide (LiO ₂ ), silver oxide (AgO) and antimony oxide (Sb ₂ O ₃ ) Adhesive containing the above metal oxide.
The pressure-sensitive adhesive according to claim 1, wherein the organic beads comprise at least one member selected from the group consisting of polystyrene and polymethylmethacrylate.
The pressure-sensitive adhesive of claim 1, wherein the content of the inorganic nanoparticles in the organic-inorganic composite particles is 10 wt% to 50 wt%.
The pressure-sensitive adhesive of claim 1, wherein the pressure-sensitive adhesive has a thickness of 15 µm to 25 µm.
A flexible organic light emitting diode display device comprising the pressure sensitive adhesive of claim 1, a flexible substrate, and an organic light emitting diode device.
The flexible organic light emitting diode display of claim 13, wherein the pressure-sensitive adhesive is present on one surface of the flexible substrate, and the organic light emitting diode element is disposed on the opposite side of the pressure-sensitive adhesive of the flexible substrate.
The flexible organic light emitting diode display of claim 13, wherein the flexible substrate comprises at least one member selected from the group consisting of polyether sulfone, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, and polyimide.
The flexible organic light emitting diode display of claim 13, wherein the flexible substrate has a refractive index of 1.45 to 1.75 for light having a wavelength of 400 nm to 800 nm.
The flexible organic light emitting diode display of claim 13, wherein the organic light emitting diode device comprises an organic light emitting layer disposed between the first and second electrodes facing each other and the first and second electrodes.
The flexible organic light emitting diode display of claim 13, further comprising a barrier layer.
19. The flexible organic light emitting diode display of claim 18, wherein the barrier layer is present between the organic light emitting diode element and the flexible substrate or opposite to the flexible substrate of the adhesive.

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