TW201808644A - Organic el display device - Google Patents

Abstract

To provide an organic EL display device in which a deterioration thereof due to ultraviolet rays is suppressed and the occurrence of hue is not caused in outdoor use. An organic EL display device includes an optical film A1 on a light emitting surface of an organic EL element. The optical film A1 includes: a polyester-based film; and a resin layer a1 containing an ultraviolet absorber and formed on a surface of the polyester-based film, the surface being on an opposite side to the organic EL element. When the outermost surface on the resin layer a1 side of the optical film A1 is irradiated with black light having a center wavelength of 365 nm, the optical film A1 satisfies a specific condition.

Description

Organic EL display device

The present invention relates to an organic EL display device.

Organic EL display devices have lower power consumption compared to liquid crystal display devices, and are therefore being used mainly for mobile information terminals.

An organic EL display device has a basic structure including a surface plate on an organic EL element including a light-emitting layer, a substrate, and the like. As the surface plate, glass is mainly used.

An organic EL display device has a problem that a phosphor or the like contained in a light emitting layer of an organic EL element is easily deteriorated by ultraviolet rays.

In particular, an organic EL display device having an organic EL element without a color filter on the light-emitting layer, or an organic EL display device in which the transparent substrate of the organic EL element is a plastic film in order to achieve flexibility Since a filter or a transparent substrate made of glass absorbs short wavelengths, there is a concern that the phosphors, phosphors, and the like constituting the organic EL element may deteriorate due to ultraviolet rays.

In order to suppress deterioration of the organic EL element due to ultraviolet rays, Patent Document 1 proposes an organic EL element in which an ultraviolet absorbing layer is formed between a light emitting layer and a substrate.

In the method of Patent Document 1, deterioration of the organic EL element due to ultraviolet rays can be suppressed.

However, the method of Patent Document 1 has a problem that the manufacturing steps of the organic EL element are complicated.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-103028

On the other hand, there are cases where various optical films are arranged on the light emitting surface of the organic EL element. As such an optical film, an optical film using a polyester-based film such as a polyethylene naphthalate film as a substrate may be used.

Among polyester films, polyethylene naphthalate film can provide a high retardation value even if it is a thin film. Therefore, although the overall thickness of the organic EL display device is made thin, interference caused by the retardation value can be suppressed. Both. In addition, since the polyethylene naphthalate film is excellent in ultraviolet absorption, even if the ultraviolet absorbing layer is not formed in the display element as in Patent Document 1, degradation of the organic EL element due to ultraviolet rays can be suppressed.

However, in the case of using an optical film using a polyethylene naphthalate film as a base material, the screen may feel blue and white when used outdoors, which may impair color tone.

As described above, the organic EL display device is often used as a mobile information terminal. Since it is frequently used outdoors, the color tone during outdoor use becomes an important issue.

An object of the present invention is to provide an organic EL display device that suppresses deterioration of an organic EL display device due to ultraviolet rays and does not generate color tone when used outdoors.

The present inventors have made intensive studies in order to solve the above problems. As a result, it was found that the polyethylene naphthalate film absorbs light in a wavelength region of ultraviolet rays and emits light in a short wavelength region of visible light in a fluorescent form. In addition, the above-mentioned problem was solved by intentionally forming a resin layer containing an ultraviolet absorber for a polyethylene naphthalate film having excellent ultraviolet absorption performance.

The present invention provides the following organic EL display devices.

[1] An organic EL display device having an optical film A1 on a light emitting surface of an organic EL element. The optical film A1 is a polyester film and a resin layer a1 containing an ultraviolet absorber. The resin layer a1 is The optical film A1 is formed on the surface opposite to the organic EL element side of the polyester film, and the optical film A1 satisfies the following condition 1:

<Condition 1>

On the outermost surface of the resin layer a1 side of the optical film A1, a black light lamp having a center wavelength of 365 nm is arranged so that the light exit surface of the black light lamp is parallel to the optical film A1. A spectral radiance meter is disposed at a position directly opposite the black light lamp through the optical film A1. The black light is caused to emit light, and the spectroradiometer is used to measure the spectral radiation of light in the direction of the normal to the surface of the optical film A1 on the opposite side of the surface illuminated by the black light at a wavelength of 400 to 470 nm per 1 nm. x1; further, with the spectroradiometer, the spectral radiation y1 of light in the normal direction of the black light lamp itself is measured at a wavelength of 400 to 470 nm for each 1 nm; the spectral radiation of each wavelength of 400 to 470 nm When the cumulative value of x1 is set to T ₁ and the cumulative value of the spectral radiation y1 at each wavelength of 400 to 470 nm is set to L ₁ , the relationship of T ₁ / L ₁ ≦ 1.00 is satisfied.

[2] An organic EL display device having a light emitting surface of an organic EL element There is an optical laminated body A2, which is made of a polyester film and a resin layer a2 containing an ultraviolet absorber, and the resin layer a2 is disposed on the opposite side of the organic EL element side of the polyester film, The optical laminated body A2 does not contain a polarizing element, and the optical laminated body A2 satisfies the following condition 2,

<Condition 2>

On the outermost surface of the optical multilayer body A2 closer to the resin layer a2 side than the polyester film, a black light lamp with a center wavelength of 365 nm is arranged so that the light exit surface of the black light lamp is parallel to the optical film; The multilayer body A2 is equipped with a spectroradiometer at a position directly opposite to the black light lamp; the black light lamp is made to emit light, and the optical multilayer body A2 is measured by the spectroradiometer at a wavelength of 400 to 470 nm for each 1 nm and the black light The spectroradiation x2 of the light in the normal direction of the surface on the opposite side of the surface illuminated by the lamp; further, the spectroradiometer measures the light in the normal direction of the black light lamp per 1nm in a region of a wavelength of 400 to 470nm When the cumulative value of the spectral radiation x2 of each wavelength of 400 to 470 nm is set to T ₂ , and the cumulative value of the spectral radiation y2 of each wavelength of 400 to 470 nm is set to L ₂ , T _{2 is} satisfied. / L ₂ ≦ 1.00.

The organic EL display device of the present invention can suppress deterioration of the organic EL display device due to ultraviolet rays, and prevent generation of color tone when used outdoors.

10‧‧‧Organic EL element

20‧‧‧Optical film A1

21‧‧‧ polyester film

22‧‧‧resin layer a1

30‧‧‧ surface plate

40‧‧‧Other optical film

50‧‧‧ polarizing element

60‧‧‧Optical multilayer A2

61‧‧‧polyester film

62‧‧‧resin layer a2

63‧‧‧hard coating

70‧‧‧touch panel

80‧‧‧ Adhesive layer

100‧‧‧Organic EL display device

100A‧‧‧Organic EL display device with touch panel

FIG. 1 is a cross-sectional view showing an embodiment of an organic EL display device according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the organic EL display device of the present invention.

FIG. 3 is a sectional view showing another embodiment of the organic EL display device of the present invention.

FIG. 4 is a sectional view showing another embodiment of the organic EL display device of the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of the organic EL display device of the present invention.

FIG. 6 is a sectional view showing another embodiment of the organic EL display device of the present invention.

FIG. 7 shows an example of the wavelength distribution of the spectral radiation of light in the normal direction of the black light lamp and the wavelength distribution of the spectral radiation of light in the direction of the normal side of the side opposite to the irradiation surface side when the PEN film is irradiated with the black light .

FIG. 8 shows an example of the wavelength distribution of the spectral radiation of light in the normal direction of the black light lamp and the wavelength distribution of the spectral radiation of light in the direction of the normal side of the side opposite to the irradiation surface side when the black film is irradiated to the PET film .

Fig. 9 shows the wavelength distribution of the spectral radiation of light in the normal direction of the black light lamp, and the light in the normal direction of the surface on the side opposite to the irradiation surface side when the black light lamp is irradiated to the surface of the resin layer a1 side of the optical film A1 An example of the wavelength distribution of split optical radiation.

Hereinafter, embodiments of the organic EL display device of the present invention will be described.

In addition, in this specification, a polyethylene naphthalate film may be called "PEN film", and a polyethylene terephthalate film may be called "PET film."

[First Embodiment]

The first embodiment of the organic EL display device of the present invention is an organic EL display device having an optical film A1 on a light emitting surface of the organic EL element. The optical film A1 is a polyester film and contains The resin layer a1 has an ultraviolet absorber. The resin layer a1 is formed on a surface of the polyester film opposite to the organic EL element side. The optical film A1 satisfies the following condition 1:

<Condition 1>

On the outermost surface of the resin layer a1 side of the optical film A1, a black light lamp having a center wavelength of 365 nm is arranged so that the light exit surface of the black light lamp is parallel to the optical film A1. A spectroradiometer is disposed at a position directly opposite the black light lamp through the optical film A1. The black light is caused to emit light, and the spectroradiometer is used to measure the spectral radiation of light in the direction of the normal to the surface of the optical film A1 on the opposite side of the surface illuminated by the black light at a wavelength of 400 to 470 nm per 1 nm. x1; further, with the spectroradiometer, the spectral radiation y1 of light in the normal direction of the black light lamp itself is measured at a wavelength of 400 to 470 nm for each 1 nm; the spectral radiation of each wavelength of 400 to 470 nm When the cumulative value of x1 is set to T ₁ and the cumulative value of the spectral radiation y1 at each wavelength of 400 to 470 nm is set to L ₁ , the relationship of T ₁ / L ₁ ≦ 1.00 is satisfied.

1 to 3 are cross-sectional views showing an example of a first embodiment of an organic EL display device according to the present invention.

The organic EL display device (100) of FIGS. 1 to 3 has an optical film A1 (20) on the light emitting surface of the organic EL element (10), and the optical film A1 is on the organic EL element side of the polyester film (21) The opposite side has a resin layer a1 (22) containing an ultraviolet absorber. The organic EL display device (100) of FIG. 1 is provided with a surface plate (30) on the optical film A1 (20), and the organic EL display device (100) of FIGS. 2 and 3 is provided with the optical film A1 (20) as Surface plate (30). The organic EL display device (100) of FIGS. 1 to 3 has a polarizing element (50) as another optical film (40) between the organic EL element (10) and the optical film A1 (20). In addition, the organic EL of FIG. 3 The display device (100) is an organic EL display device (100A) with a touch panel having a touch panel (70).

The organic EL element (10) of the organic EL display device (100) of FIGS. 1 to 3 is composed of a metal electrode (14), a light-emitting layer (13), a transparent electrode (12), and a transparent substrate (11). Furthermore, the light emitting layer (13) of FIGS. 1 to 3 includes a red light emitting layer (13a), a green light emitting layer (13b), and a blue light emitting layer (13c). The organic EL element (10) of the organic EL display device (100) of FIGS. 1 to 3 shows an embodiment of the organic EL element of the three-color independent method.

In addition, the organic EL display device (100) of FIGS. 1 to 3 shows a state in which an air layer is easily interposed between the members only by overlapping the members. In FIG. 1 to FIG. 3, in order to easily understand the so-called interstitial air layer, the distance between the components is exaggerated.

The organic EL display device according to the first embodiment is not limited to those shown in FIGS. 1 to 3. For example, each member constituting the organic EL display device (100) may be integrated via, for example, an adhesive layer.

<Condition 1>

Condition 1 means that when the ultraviolet (black light) is irradiated, fluorescent light emission is prevented from being generated from the polyester film constituting the optical film A1.

When the condition 1 is not satisfied, the screen is blue and white when used outdoors.

Hereinafter, the condition 1 will be further described using drawings.

The solid lines in FIGS. 7 and 8 are examples of the wavelength distribution of the spectral radiation of light in the normal direction of a black light lamp with a center wavelength of 365 nm. The single-dotted dotted line in FIG. 7 is an example of the wavelength distribution of the spectral radiation of light in the direction of the normal of the black light lamp irradiating surface side of the PEN film when the black light lamp is irradiated to the PEN film. The dotted line in FIG. 8 is the side of the black light irradiation surface of the PET film when the black light is irradiated to the PET film. An example of the wavelength distribution of the spectral radiation of light in the normal direction of the opposite surface.

According to FIG. 7 and FIG. 8, it can be confirmed that when a polyester film such as a PEN film or a PET film is irradiated with ultraviolet rays, light in a short wavelength region of visible light is emitted as fluorescent light. In addition, it was confirmed that the peak of the fluorescence emission of the PEN film was about 20 times the peak of the fluorescence emission of the PET film.

Furthermore, in FIGS. 7 and 8, “E-05” on the vertical axis represents a negative 5 power of 10, “E-04” represents a negative 4 power of 10, and “E-03” represents a negative 3 power of 10. power.

Next, the solid line in FIG. 9 is an example of the wavelength distribution of the spectral radiation of light in the normal direction of a black light lamp with a center wavelength of 365 nm. The dotted line in FIG. 9 is the side opposite to the black light lamp irradiation surface side of the optical film A1 when the black light lamp is irradiated to the outermost surface of the resin layer a1 of the optical film A1 having the resin layer a1 containing an ultraviolet absorber on the PEN film. An example of the wavelength distribution of the spectral radiation of light in the direction of the normal to the face.

By comparing FIG. 7 with FIG. 9, it can be confirmed that by specifically forming a resin layer a1 containing an ultraviolet absorber for a PEN film having excellent ultraviolet absorbency, it is possible to prevent fluorescent light from being generated from the PEN film when irradiated with ultraviolet rays.

Furthermore, in FIG. 9, “E-05” on the vertical axis represents a power of minus 5 to 10.

As described above, satisfying condition 1 means that when the optical film A1 receives ultraviolet rays, it prevents the fluorescent light emission in the short wavelength region of visible light from being generated from the polyester film constituting the optical film A1. That is, by satisfying Condition 1, it is possible to prevent the screen from feeling blue and white when the organic EL display device is used outdoors.

Furthermore, in Condition 1, the spectral radiation x1 of light in the direction of the normal of the surface of the optical film A1 opposite to the surface illuminated by the black light lamp (the surface of the optical film A1 on the side opposite to the visually visible side) is measured. Since the fluorescence is scattered equally in all directions, it can be said that the spectral radiation x1 is essentially Spectral radiation equal to the light in the direction of the normal to the side of the visually visible side of the optical film A1. Regarding the condition 2 of the second embodiment described below, the same can be said.

In Condition 1, "400 to 470 nm" shows light emission in the wavelength distribution of the spectral radiation of light in the normal direction of the PEN film when the PEN film is irradiated with a black light lamp in Fig. 7 (single dotted line in Fig. 7). The upper and lower wavelength limits of the peak value [about 9.2 × 10 ^-4 (W / sr / m ² / nm)] 1/2 of the value [about 4.6 × 10 ^-4 (W / sr / m ² / nm)] Benchmark. That is, 400 to 470 nm indicates a wavelength range in which the fluorescence emission of the PEN film is strong. Regarding the condition 2 of the second embodiment described below, the same can be said.

In the condition 1, the relationship of T ₁ / L ₁ ≦ 0.70 is preferably satisfied, the relationship of T ₁ / L ₁ ≦ 0.50 is more preferably satisfied, and the relationship of T ₁ / L ₁ ≦ 0.45 is more preferable.

In Condition 1, a black light lamp with an ultraviolet illuminance of 6000 μW / cm ² at an irradiation distance of 40 cm is preferably used, and the distance between the black light lamp and the optical film A1 is set to 40 cm, and the black light lamp is irradiated. Here, the ultraviolet illuminance is a value obtained by measuring the illuminance of a wavelength region of UV-A (wavelength 315 to 400 nm) per 1 nm, and accumulating the illuminance of each wavelength of 315 to 400 nm.

The ultraviolet illuminance of sunlight is about 6000 μW / cm ² . Therefore, a black light lamp with an ultraviolet illuminance of 6000 μW / cm ² at an irradiation distance of 40 cm is used, and a condition in which the distance between the black light lamp and the optical film A1 is set to 40 cm (hereinafter referred to as "outdoor ultraviolet conditions") is used to thereby Obtain measurement conditions that meet the outdoor environment. That is, it is preferable to satisfy the condition 1 under the above-mentioned outdoor ultraviolet conditions. Regarding the condition 2 of the second embodiment described below, the same can be said.

Furthermore, in the following examples, a black light lamp with an ultraviolet illuminance of 6000 μW / cm ² or more at an irradiation distance of 40 cm was used, and the distance between the black light lamp and the optical film A1 was set to 1 cm. That is, in the following examples, an environment where the ultraviolet illuminance is stronger than the above-mentioned outdoor ultraviolet conditions is used. When the condition 1 is satisfied in an environment where the ultraviolet illuminance is stronger than the above-mentioned outdoor ultraviolet conditions, it can be said that the condition 1 is also satisfied under the above-mentioned outdoor ultraviolet conditions.

Generally, among the light emitted from a black light lamp, light having a wavelength of 400 nm or more is an intensity that is hardly recognizable by humans. It is preferable that the black light lamp used in the condition 1 is that the above-mentioned L ₁ (the cumulative value of the spectral radiation y1 of light of each wavelength of wavelengths of 400 to 470 nm in the normal direction of the black light lamp) is 0.0020 W / sr / m ² / nm or less , More preferably 0.0015 W / sr / m ² / nm or less.

In the condition 1, the spectroradiometer may be a general one.

In addition, in this specification, the measurement of the spectral radiation of light in the normal direction is performed by setting the measurement angle to 0.2 degrees.

<Optical film A1>

The optical film A1 has a polyester-based film and a resin layer a1 containing an ultraviolet absorber formed on a surface opposite to the organic EL element side of the polyester-based film, and satisfies Condition 1 described above.

<Polyester film>

Examples of the polyester-based film constituting the optical film A1 include a polyethylene terephthalate film (PET film), a polyethylene naphthalate film (PEN film), and a polybutylene terephthalate film. (PBT film) and so on. From the viewpoint of improving the mechanical strength and increasing the retardation value, these polyester-based films are preferably stretched polyester-based films. Examples of extension include vertical uniaxial extension, tenter extension, sequential biaxial extension, and simultaneous biaxial extension.

Among polyester films, a PEN film is preferred. The PEN film can obtain a high retardation value in a thin film. Although the thickness of the entire organic EL display device is made thin, interference unevenness caused by the retardation value can be suppressed, which is excellent in this respect. In addition, the PEN film is also excellent in ultraviolet absorption. Furthermore, "interference unevenness" refers to the rainbow-shaped unevenness that is visually recognized when wearing polarized sunglasses to observe the picture.

From the viewpoint of the balance between prevention of interference unevenness and thin film, the polyester film is preferably one having a retardation value of 3,000 to 30,000 nm, more preferably 5,000 to 20,000 nm, and still more preferably 6,000 to 15,000 nm. And more preferably 8,000 to 14,000 nm. The retardation value referred to here is a retardation value at a wavelength of 550 nm.

The retardation value of the polyester film is orthogonal to the above-mentioned retardation axis direction in the plane of the polyester film by the refractive index n _x in the direction of the maximum refractive index in the plane of the polyester film, that is, the retardation axis direction. The direction is the refractive index n _{y in} the direction of the advancing axis and the thickness d of the polyester film is expressed by the following formula.

Delay value (Re) = (n _x -n _y ) × d

The delay value can be measured, for example, under the trade names "KOBRA-WR" and "PAM-UHR100" manufactured by Oji Measurement Equipment.

The delay value can also be calculated by the following steps.

(1) After using two or more polarizing elements to determine the orientation axis direction (direction of the main axis) of the polyester film, use an Abbe refractometer (NAR-4T manufactured by Atago) to obtain two axes (alignment The refractive index (n _x , n _y ) of the axis and the axis orthogonal to the alignment axis). Here, an axis exhibiting a larger refractive index is defined as a late phase axis.

(2) The thickness d of the optical film is measured with a micrometer (trade name: Digimatic Micrometer, manufactured by Mitutoyo), and the unit is converted to nm.

(3) Calculate the retardation based on the product of the birefringence (n _x -n _y ) and the thickness d (nm) of the film.

From the viewpoints of operability and film formation, the thickness of the polyester film is preferably 5 to 300 μm, more preferably 10 to 200 μm, and still more preferably 15 to 100 μm.

<Resin layer a1>

The resin layer a1 is a layer containing an ultraviolet absorber and is an organic EL formed on a polyester film. It is formed on the side opposite to the element side.

When the polyester film is a PEN film, the PEN film has excellent ultraviolet absorption, so even if a layer containing an ultraviolet absorber is not formed on the PEN film, the phosphor or phosphor constituting the organic EL element can be prevented. Deterioration due to ultraviolet rays. In the first embodiment, even when the polyester-based film is a PEN film having excellent ultraviolet absorptivity, an ultraviolet absorbing layer is intentionally formed, thereby preventing fluorescent light from being generated from the PEN film.

The resin layer a1 preferably contains an ultraviolet absorber and a binder resin.

Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and UV absorber.

The ultraviolet absorber preferably has an absorption peak in a region of UV-A (wavelength 315 to 400 nm), more preferably has an absorption peak in a region of wavelength 350 to 390 nm, and more preferably has an absorption peak in a region of wavelength 360 to 380 nm. Those who absorb the crest.

Examples of the ultraviolet absorber having an absorption peak in a region of a wavelength of 350 to 390 nm include a sesaminol-type benzotriazole-based ultraviolet absorber and a resorcinol-type benzotriazole-based ultraviolet absorber. Examples of the ultraviolet absorber having an absorption peak in a region of a wavelength of 360 to 380 nm include a sesaminol-type benzotriazole-based ultraviolet absorber.

Examples of the sesaminol-type benzotriazole-based ultraviolet absorber include compounds containing sesaminol and a nitrogen atom at the 2-position of the benzotriazole ring (sesamol-type benzotriazole-based monomer) The composition of the polymer. Examples of the sesaminol-type benzotriazole-based monomer include compounds represented by the following general formula (I).

[In formula (I), R ¹ represents a hydrogen atom or a methyl group. R ² represents a linear or branched alkylene group having 1 to 6 carbon atoms or a linear or branched oxyalkylene group having 1 to 6 carbon atoms)]

Examples of the resorcinol-type benzotriazole-based ultraviolet absorber include compounds containing resorcinol and a nitrogen atom at the 2-position of the benzotriazole ring (resorcinol-type benzo Triazole-based monomer). Examples of the resorcinol-type benzotriazole-based monomer include compounds represented by the following general formula (II).

[In formula (II), R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a linear or branched alkylene group having 1 to 6 carbon atoms. R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms)]

The composition containing a sesaminol-type benzotriazole-based monomer and the composition containing a resorcinol-type benzotriazole-based monomer may contain other monomers.

Examples of other monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, ( (Meth) acrylate, Tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, lauryl (meth) acrylate, (meth) (Meth) acrylic acid alkyl esters such as stearyl acrylate; hydroxyethyl (meth) acrylate, hydroxypropyl ethyl (meth) acrylate, hydroxybutyl (meth) acrylate, modified caprolactone Hydroxyl-containing unsaturated monomers, such as (meth) acrylate.

When a composition containing a resorcinol-type benzotriazole-based monomer or a composition containing a sesaminol-type benzotriazole-based monomer is subjected to copolymerization reaction, a conventionally known solution polymerization method and emulsification can be adopted The polymerization method, suspension polymerization method, and block polymerization method are not particularly limited.

From the viewpoint that it is easy to satisfy the condition 1, and from the viewpoint of suppressing the ultraviolet absorbent from oozing out of the resin layer a1, the content of the ultraviolet absorber is preferably 10 to 95% by mass, and more preferably 30% of all solid components of the resin layer a1 ~ 93 mass%, more preferably 60-90 mass%, and still more preferably 70-85 mass%. The polymer of the composition containing the sesaminol-type benzotriazole-based monomer or the polymer of the composition containing the resorcinol-type benzotriazole-based monomer is relatively easy to bleed because of its large molecular weight. Making the content relatively large is preferable in this respect.

Examples of the binder resin include a thermoplastic resin, a cured product of a thermosetting resin composition, and a cured product of a radiation-hardening resin composition. Among these, from the viewpoints of durability and damage suppression, a hardened material of a thermosetting resin composition and a hardened material of a radiation-hardening resin composition are more preferable, and a radiation-hardening resin composition is more preferable. Of hardened.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is hardened by heating.

Examples of the thermosetting resin include acrylic resins, urethane resins, phenol resins, urea-melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. To the thermosetting resin composition, a hardening agent is added to these hardening resins as necessary.

The radiation-hardenable resin composition is a composition containing a compound having a radiation-hardenable functional group (hereinafter, also referred to as a "radiation-hardenable compound"). Examples of the free radiation-curable functional group include ethylenically unsaturated bonding groups such as (meth) acrylfluorenyl, vinyl, and allyl groups, and epoxy groups and oxetanyl groups. Among them, preferred are Ethylene unsaturated bond. Among the ethylenically unsaturated bond groups, a (meth) acrylate group is preferred. Hereinafter, a free radiation-curable compound having a (meth) acrylfluorenyl group is referred to as a (meth) acrylate-based compound.

In addition, in this specification, "(meth) acrylate" means a methacrylate and an acrylate. In addition, in this specification, "free radiation" means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules. Generally, ultraviolet rays (UV) or electron beams (EB) are used. Electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion beams can also be used.

The free radiation-curable compound is preferably a polyfunctional free radiation-curable compound having two or more of the above-mentioned functional groups; or a polyfunctional free radiation-hardenable compound and a monofunctional free-radiation hardening having only one of the above-mentioned functional groups Of sexual compounds.

When the free radiation-curable compound is an ultraviolet-curable compound, the free radiation-curable composition preferably contains additives such as a photopolymerization initiator or a photopolymerization accelerator.

Examples of the photopolymerization initiator include acetophenone, benzophenone, α-hydroxyalkyl phenone, Michelin, benzoin, benzophenone methyl ketal, and benzophenone benzoic acid. Ester, α-fluorenyl oxime ester, 9-oxosulfur One or more of the categories.

In addition, the photopolymerization accelerator can reduce polymerization inhibition caused by air at the time of hardening and increase the rate of hardening, and examples thereof include isoamyl p-dimethylaminobenzoate and ethyl p-dimethylaminobenzoate. More than one of them.

Furthermore, the adhesive resin of the resin layer a1 can be made into an adhesive composition or a hardened | cured material of an adhesive composition. With such a configuration of the adhesive resin, the resin layer a1 can function as an adhesive layer, and the optical film A1 can be integrated with other members such as a surface plate.

Examples of the adhesive composition include a general-purpose pressure-sensitive adhesive composition, a heat-sensitive adhesive composition, and a free radiation-curable adhesive composition.

The resin layer a1 may contain particles. By containing particles in the resin layer, anti-glare properties can be imparted.

The particles are not particularly limited as long as they have translucency, and either organic particles or inorganic particles can be used. The shape of the particles is not particularly limited, and examples thereof include shapes such as a spherical shape, a disc shape, a rugby shape, and an irregular shape. The particles may be any of hollow particles, porous particles, and solid particles.

Examples of the organic particles include polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, and polysiloxane. , Fluorine resin and polyester resin.

Examples of the inorganic particles include particles composed of silicon dioxide, aluminum oxide, zirconia, and titanium dioxide.

The content of the particles is preferably 0.2 to 15.0% by mass, more preferably 0.5 to 10.0% by mass, and still more preferably 1.0 to 6.0% by mass based on 100 parts by mass of the binder resin of the resin layer a1.

From the viewpoint of easily satisfying the condition 1 and the viewpoint of the balance of thinning, the resin The thickness of the layer a1 is preferably 1 to 800 μm, more preferably 2 to 250 μm, still more preferably 3 to 100 μm, and still more preferably 5 to 20 μm.

The resin layer a1 may not be directly formed on the polyester film. For example, the optical film A1 may have another layer such as an easy-adhesion layer between the resin layer a1 and the polyester-based film. The position of the resin layer a1 in the optical film A1 is preferably set to the position of the outermost surface on the opposite side of the organic EL element.

The optical film A1 may have a functional layer on the surface of the organic EL element side of the polyester film. Examples of the functional layer include an adhesion prevention layer, an interference prevention layer, and an ultraviolet absorbing layer. The ultraviolet absorbing layer on the organic EL element side may have the same structure as the resin layer a1 or may have a different structure from the resin layer a1.

From the viewpoint of suppressing fluorescent light emission of the polyester film and easily satisfying Condition 1, the average value of the spectral transmittance of 360 to 380 nm of the optical film A1 is preferably 0.15% or less, more preferably 0.10% or less, and further It is preferably at most 0.05%, more preferably at most 0.02%.

From the same viewpoint, the average value of the spectral transmittance of 370 to 380 nm of the optical film A1 is preferably 0.15% or less, more preferably 0.10% or less, still more preferably 0.05% or less, and even more preferably 0.02. %the following.

It is believed that a wavelength of 360 to 380 nm, especially a wavelength of 370 to 380 nm, will greatly affect the fluorescence emission of PEN. Therefore, the spectral transmittance of these wavelength regions is preferably in the above range.

In this specification, the average value of the spectral transmittance of 360 to 380 nm and the average value of the spectral transmittance of 370 to 380 nm mean the average value of the transmittance of each wavelength when the measurement wavelength is set to a 0.5 nm interval. The measurement condition of the spectral transmittance is preferably a 2 degree field of view, and D65 is used as the light source.

The portion where the optical film A1 is arranged in the organic EL display device of the first embodiment is not particularly limited as long as it is the light emitting surface of the organic EL element.

Furthermore, as shown in FIGS. 1 to 3, when the polarizing element 50 is used as another optical film (40) in the organic EL display device, the optical film A1 (20) is preferably disposed more than the polarizing element (50). Close to the visual discerner side. In other words, it is preferable to provide a polarizing element between the optical film A1 and the organic EL element. By making the polarizing element and the optical film A1 into the above-mentioned arrangement relationship, and setting the retardation value of the optical film A1 to the above-mentioned preferred range, interference unevenness peculiar to the retardation value can be easily suppressed.

The optical film A1 can be used in, for example, a protective film for a polarizing element, a constituent member of a surface plate (30), and a touch panel (70), and is used in an organic EL display device. Moreover, even if the optical film A1 does not have the above-mentioned use, it can also be used as an interference unevenness suppression member in an organic EL display device.

<Other optical films>

The organic EL display device of the first embodiment may have another optical film different from the optical film A1.

Examples of other optical films include a polarizing element, a 1/4 λ plate, and a retardation film.

The polarizing element is preferably provided between the optical film A1 and the organic EL element.

Examples of the polarizing element include dyeing and stretching a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, and an ethylene-vinyl acetate copolymer saponified film with iodine or the like. Sheet-type polarizing element; wire-grid-type polarizing element composed of a plurality of metal wires arranged in parallel; coating-type polarizing element coated with liquid crystal or dichroic guest-host material; multilayer film-type polarizing Components, etc. Furthermore, the polarizing elements may be reflective polarizing elements having a function of reflecting a non-transmissive polarizing component.

Preferably, both sides of the polarizing element are covered by a transparent protective plate such as a plastic film. As the transparent protective plate, an optical film A1 may also be used.

In an organic EL display device, a polarizing element is used to provide anti-reflection properties in combination with a 1/4 λ plate, for example.

1/4 λ plate and retardation film can be used universally. The 1/4 λ plate is preferably arranged closer to the organic EL element side than the polarizing element. The retardation film is preferably arranged on the organic EL element side of the polarizing element.

<Surface board>

A surface plate is preferably provided on the outermost surface on the opposite side of the organic EL element side of the organic EL display device.

The surface plate is preferably a resin surface plate. When the surface plate is made of glass, due to the ultraviolet absorption characteristics of glass, it is not easy to produce fluorescent light from a polyester film. Therefore, when the surface plate is a resin surface plate, the effect of the first embodiment is clearly exhibited.

The resin surface plate may be a single-layer plastic film, or may be formed by bonding a plurality of plastic films through an adhesive layer. Moreover, the said optical film A1 can also be used as a resin-made surface plate.

As the plastic film constituting the resin-made surface plate, a polyimide film or an aromatic polyimide film is preferred from the viewpoint of bending resistance.

From the viewpoint of thin film formation and protection of the organic EL element, the thickness of the resin-made surface plate is preferably 10 to 1,000 μm, and more preferably 300 to 800 μm.

<Organic EL element>

Organic EL elements are mainly classified into three types: a color conversion method, a color filter method, and a three-color independent method.

The color conversion method is basically composed of a metal electrode, a blue light emitting layer, a fluorescent layer (red fluorescent layer, green fluorescent layer), a color filter (blue color filter), a transparent electrode, and a transparent substrate. Made up. In the color conversion method, the light from the blue light-emitting layer is converted into red and green by a red fluorescent layer and a green fluorescent layer, and blue is realized by a color filter to achieve high chroma.

The color filter method is composed of a basic structure of a metal electrode, a white light-emitting layer, a color filter (color filters of three colors of red, green, and blue), a transparent electrode, and a transparent substrate. In the color filter method, the light from the white light-emitting layer is converted into red, green, and blue by the color filter.

The three-color independent method is shown in Figs. 1 to 3, and is composed of a basic structure of a metal electrode, a light-emitting layer (a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer exist independently), a transparent electrode, and a transparent substrate. In the three-color independent method, three primary colors of red, green, and blue are produced without using a color filter.

In the first embodiment, the organic EL element is preferably a three-color independent organic EL element.

Three-color independent organic EL elements are those with sharp red, green, and blue spectral spectra. If the red, green, and blue spectral spectra are steep, respectively, in the CIE-xy chromaticity diagram, the value of the red vertex coordinate system x is larger, the value of y is smaller, and the value of the green vertex coordinate system x is smaller. , The value of y becomes larger, the value of the blue vertex coordinate system x is smaller, and the value of y becomes smaller. That is, if the spectral spectra of red, green, and blue are steep, respectively, the area of the triangle formed by connecting the vertex coordinates of the red, green, and blue colors in the CIE-xy chromaticity diagram becomes larger, and the color can be reproduced The scope of the domain becomes wider. On the other hand, the broader range of reproducible color gamut means that the color gamut is easily affected by external factors such as fluorescent light emission of the PEN film caused by ultraviolet rays. Therefore, the three-color independent organic EL element is preferable in that the effect of the first embodiment is easily exerted effectively.

In addition, the light extraction efficiency of the organic EL element has become a problem. In order to improve the light extraction efficiency, the organic EL element having a three-color independent method has a microcavity structure in many cases. The organic EL element with a three-color independent method with a microcavity structure improves the light extraction efficiency, and the red, green, and blue spectral spectra Getting steeper. Therefore, an organic EL element having a three-color independent system with a microcavity structure is preferable in that the effects of the first embodiment are particularly effective.

As a standard for expressing a color gamut, "ITU-R Advisory BT.2020 (hereinafter, referred to as" BT.2020 ") and the like can be cited. ITU-R is the abbreviation of "International Telecommunication Union-Radiocommunication Sector", and ITU-R advises BT.2020 to be the international standard for the ultra-high-definition color gamut. The organic EL element is preferably one having a coverage of BT.2020 based on the CIE-xy chromaticity diagram represented by the following formula of 60% or more, more preferably 65% or more, and even more preferably 70% or more.

<Expression of coverage ratio of BT.2020> [Area of the area of the CIE-xy chromaticity diagram of the organic EL element and the area of the CIE-xy chromaticity diagram of BT.2020 / CIE-xy of BT.2020 Degree chart area] × 100 (%)

The "area of the CIE-xy chromaticity diagram of the organic EL element" required to calculate the coverage of BT.2020 can measure the x value and y of the CIE-Yxy color system when displaying red, green, and blue, respectively. The value is calculated based on the "red vertex coordinates", "green vertex coordinates", and "blue vertex coordinates" obtained from the measurement results. The x and y values of the CIE-Yxy color measurement system can be measured, for example, by a spectroradiometer CS-2000 manufactured by Konica Minolta.

In the first embodiment, the transparent substrate constituting the organic EL element may be a glass plate, but is preferably a resin plate.

In the case where the transparent substrate constituting the organic EL element is a glass plate, it is difficult to generate fluorescent light emission of the polyester film due to the ultraviolet absorption characteristics of the glass. Therefore, when the transparent plate constituting the organic EL element is a resin plate, the effect of the first embodiment is clearly exhibited. In addition, by using a resin plate as the transparent substrate constituting the organic EL element, flexibility can be imparted to the organic EL display device. under The second embodiment can be said to be the same.

In the organic EL display device of the first embodiment, it is preferable that the light emitting layer of the organic EL element does not have a glass plate on the light emitting surface side.

When the light-emitting layer of the organic EL element has a glass plate on the light-emitting surface side, it is difficult to generate fluorescent light emission of the polyester film due to the ultraviolet absorption characteristics of the glass. Therefore, when the light emitting layer of the organic EL element does not have a glass plate on the light emitting surface side, the effect of the first embodiment is clearly exhibited. In addition, by adopting a configuration in which the light emitting layer from the organic EL element does not have a glass plate on the light emitting surface side, flexibility can be provided to the organic EL display device. The second embodiment described below can be said to be the same.

<Touch panel>

The organic EL display device of the first embodiment may be an organic EL display device with a touch panel having a touch panel on a light emitting surface of the organic EL element.

The positional relationship between the touch panel and the optical film A1 is not particularly limited. For example, as shown in FIG. 3, a touch panel (70) may be provided between the organic EL element (10) and the optical film A1 (20), or a touch panel (70) may be provided on the optical film A1 (20). . As a constituent member of the touch panel (70), an optical film A1 (20) can be used.

Examples of the touch panel include a resistive film type touch panel, an electrostatic capacity type touch panel, an electromagnetic induction type touch panel, an optical type touch panel, and an ultrasonic type touch panel.

The capacitive touch panel includes a surface type and a projection type, and a projection type is often used. The capacitive touch panel of the projection type is formed by connecting the X-axis electrode and the Y-axis electrode orthogonal to the X-axis electrode to the connecting circuit. To explain the basic structure more specifically, (1) forming an X-axis electrode on each surface of a transparent substrate and State of Y-axis electrode; (2) State of sequentially forming X-axis electrode, insulator layer, and Y-axis electrode on a transparent substrate; (3) Form X-axis electrode on a transparent substrate, and form on another transparent substrate The Y-axis electrode is laminated with an adhesive layer or the like. In addition, it is possible to cite a state in which the other transparent substrates are laminated in these basic aspects.

The resistive film type touch panel has a configuration in which a pair of transparent substrates above and below a conductive film are arranged with a conductive film facing each other through a spacer as a basic structure, and a circuit is connected to the basic structure.

Specific examples of using the optical film A1 (20) as a constituent member of the touch panel include the following: using the optical film A1 (20) as the structure of the transparent substrate of the electrostatic capacitance type touch panel; using the optical film A1 (20) The structure of the transparent substrate as the above-mentioned resistive film type touch panel.

[Second Embodiment]

The second embodiment of the organic EL display device of the present invention is an organic EL display device having an optical laminate A2 on the light emitting surface of the organic EL element. The optical laminate A2 has a polyester film and an ultraviolet absorber. The resin layer a2 is disposed on the opposite side of the organic EL element side of the polyester film. The optical laminated body A2 does not contain a polarizing element. The optical laminated body A2 satisfies the following condition 2,

<Condition 2>

On the outermost surface of the optical multilayer body A2 closer to the resin layer a2 side than the polyester film, a black light lamp with a center wavelength of 365 nm is arranged so that the light exit surface of the black light lamp is parallel to the optical film; The multilayer body A2 is equipped with a spectroradiometer at a position directly opposite to the black light lamp; the black light lamp is made to emit light, and the optical multilayer body A2 is measured by the spectroradiometer in a region of a wavelength of 400 to 470 nm for every 1 nm, and the black light passes through the black light. The spectroradiation x2 of the light in the normal direction of the surface on the opposite side of the surface illuminated by the lamp; further, the spectroradiometer measures the light in the normal direction of the black light lamp per 1nm in a region of a wavelength of 400 to 470nm When the cumulative value of the spectral radiation x2 of each wavelength of 400 to 470 nm is set to T ₂ , and the cumulative value of the spectral radiation y2 of each wavelength of 400 to 470 nm is set to L ₂ , T _{2 is} satisfied. / L ₂ ≦ 1.00.

4 to 6 are cross-sectional views showing an example of a second embodiment of the organic EL display device of the present invention.

The organic EL display device (100) of FIGS. 4 to 6 has an optical multilayer body A2 (60) on a light emitting surface of the organic EL element (10). In FIGS. 4 to 6, the optical laminate A2 (60) includes a polyester film (61), and a resin layer a2 containing an ultraviolet absorber, which is disposed on the opposite side of the organic EL element side of the polyester film ( 62). Moreover, in FIGS. 4-6, the optical laminated body A2 (60) does not contain a polarizing element.

The organic EL display device (100) of FIGS. 4 to 6 includes a polarizing element (50) between the organic EL element (10) and the optical multilayer body A2 (60). The organic EL display device (100) of FIGS. 5 and 6 is an organic EL display device (100A) with a touch panel and a touch panel (70) on the display element (10). Furthermore, the organic EL display device (100) of FIG. 6 includes a 1/4 λ plate (64) on the organic EL element side of the polarizing element (10).

Moreover, in FIG. 4 and FIG. 5, each member in the optical laminated body A2 (60) is integrated and laminated | stacked via the adhesive layer (80). On the other hand, in FIG. 6, all components are not integrated, and an air layer is interposed between the touch panel (70) and the hard coat layer (63). Furthermore, in order to easily understand the so-called intervening air layer, the air layer in FIG. 6 exaggerates the distance between the touch panel (70) and the hard coat layer (63). In addition, in FIGS. 4 and 6, the resin layer a2 (62) doubles as 剂 层 (80).

In addition, the organic EL element (10) of the organic EL display device (100) of FIGS. 4 to 6 shows an embodiment of the organic EL element of the three-color independent method.

<Condition 2>

Condition 2 means that when the ultraviolet rays (black light) are irradiated, fluorescent light emission is prevented from being generated from the polyester film constituting the optical laminate A2.

When the condition 2 is not satisfied, the screen is blue and white when used outdoors.

As described in the first embodiment, when a polyester film such as a PEN film or a PET film is irradiated with ultraviolet rays, light in a short wavelength region of visible light is emitted in a fluorescent form (FIG. 7 and FIG. 8). Therefore, the optical laminate A2 containing a polyester film also produces the same phenomenon when irradiated with ultraviolet rays.

In the second embodiment, by forming a resin layer a2 containing an ultraviolet absorber on the opposite side of the organic EL element side of the polyester film of the optical laminate A2, it is possible to prevent fluorescence from being generated from the polyester film when the ultraviolet light is irradiated. To meet condition 2.

In the condition 2, the relationship of T ₂ / L ₂ ≦ 0.70 is preferably satisfied, the relationship of T ₂ / L ₂ ≦ 0.50 is more preferably satisfied, and the relationship of T ₂ / L ₂ ≦ 0.45 is more preferably satisfied.

The black light lamp used in the condition 2 is preferably the above-mentioned L ₂ (cumulative value of the spectral radiation y2 of light with a wavelength of 400 to 470 nm at each wavelength in the normal direction of the black light lamp) of 0.0020 W / sr / m ² / nm or less , More preferably 0.0015 W / sr / m ² / nm or less.

<Optical multilayer body A2>

The optical laminated body A2 has a polyester-based film and a resin layer a2 containing an ultraviolet absorber disposed on the opposite side of the organic EL element side of the polyester-based film, does not contain a polarizing element, and satisfies the above Condition 2.

In addition, the optical laminated body A2 may be formed by laminating various components in an integrated manner, for example, through the adhesive layer 80 as shown in FIGS. 4 and 5, and as shown in FIG. 6, a part or all of the components may be unbonded. Either the agent layer or the like is overlapped.

From the viewpoint of suppressing interface reflection, it is preferable that each member of the optical multilayer body A2 does not have an air layer, and is integrated through, for example, an adhesive layer.

<Polyester film>

As the embodiment of the polyester-based film constituting the optical laminate A2, the same embodiment as the polyester-based film of the first embodiment can be adopted.

<Resin layer a2>

The resin layer a2 is a layer containing an ultraviolet absorber, and is arranged in the organic EL display device on the opposite side to the organic EL element side of the polyester film.

The position of the resin layer a2 in the optical multilayer body A2 is not particularly limited as long as it is a polyester film as a reference and is on the opposite side of the organic EL element side. The positions of the resin layer a2 (62) include the following positions: as shown in FIG. 4, between the polyester-based film (61) and the surface plate (30); as shown in FIG. 5, the polyester-based film (61) ) And the touch panel (70); as shown in FIG. 6, above the touch panel (70).

As shown in FIGS. 4 and 6, the resin layer a2 (62) can also serve as an adhesive layer (80).

As the embodiment of the resin layer a2, the same embodiment as the resin layer a1 of the first embodiment described above can be adopted. By having the resin layer a2 having such a configuration, the condition 2 can be easily satisfied.

The optical laminated body A2 may have a member other than a polyester film and a resin layer A2. Examples of such members include a surface plate, a touch panel, a 1/4 λ plate, and an adhesive layer.

An embodiment of the surface plate constituting the optical laminated body A2 can be adopted as the first embodiment described above. The embodiment has the same surface plate. For example, the surface plate constituting the optical laminate A2 is preferably a resin surface plate.

The surface plate may be assembled in the optical laminated body A2 as a constituent member of the optical laminated body A2, or may be set as a constituent member independent of the optical laminated body A2.

The embodiment of the touch panel constituting the optical laminated body A2 can be the same as the embodiment of the touch panel of the first embodiment described above.

The touch panel can be assembled into the optical laminated body A2 as a constituent member of the optical laminated body A2, or can be set as a constituent member independent of the optical laminated body A2.

In addition, it is preferable that the constituent member of the optical laminated body A2 does not contain a glass plate. In the case where the constituent member of the optical laminate A2 contains a glass plate, it is difficult to generate fluorescent light emission of the polyester film due to the ultraviolet absorption characteristics of the glass. Therefore, when the constituent member of the optical laminated body A2 does not include a glass plate, the effect of the second embodiment is clearly exhibited.

From the viewpoint of suppressing the fluorescent light emission of the polyester film and easily satisfying Condition 2, the average value of the spectral transmittance of 360 to 380 nm of the optical laminated body A2 is preferably 0.15% or less, more preferably 0.10% or less, It is more preferably 0.05% or less, and still more preferably 0.02% or less.

From the same viewpoint, the average value of the spectral transmittance of 370 to 380 nm of the optical multilayer body A2 is preferably 0.15% or less, more preferably 0.10% or less, still more preferably 0.05% or less, even more preferably 0.02% or less.

<Other optical films>

The organic EL display device according to the second embodiment may include a polarizing element, a retardation film, or the like as another optical film.

The embodiment of the polarizing element and the retardation film can be the same as that of the first embodiment. And the retardation film are the same.

<Polarizing element>

The polarizing element is preferably provided between the optical film laminate A2 and the organic EL element.

As the embodiment of the polarizing element in the organic EL display device of the second embodiment, the same embodiment as the polarizing element of the first embodiment can be adopted. The polarizing element can be integrated with the optical film laminate A2 via an adhesive layer.

<Organic EL element>

As the embodiment of the organic EL element of the second embodiment, the same embodiment as the organic EL element of the first embodiment can be adopted. For example, in the second embodiment, the transparent substrate constituting the organic EL element may be a glass plate, but a resin plate is preferred.

In the organic EL display device of the second embodiment, it is preferable that the light emitting layer of the organic EL element does not have a glass plate on the light emitting surface side.

[Example]

Next, the present invention will be described in more detail by examples, but the present invention is not limited to these examples.

1. Production of polyester film

<Production of PEN Film>

Polyethylene naphthalate was melted at 290 ° C., passed through a film forming die, extruded in a sheet form, and allowed to adhere to a water-cooled rotating quenching drum for cooling to produce an unstretched film. Using a biaxial stretching test device (Toyo Seiki Co., Ltd.), the unstretched film was preheated at 120 ° C for 1 minute, and the fixed end was uniaxially stretched 4.0 times at 120 ° C to produce birefringent optics in the plane. membrane. The refractive index of the optical film at a wavelength of 550 nm is n _x = 1.875, n _y = 1.635, and Δn = 0.240.

The film thickness of the optical film was adjusted to obtain a PEN film having a retardation value of 12,000 nm.

<Production of PET film>

Polyethylene terephthalate was melted at 290 ° C, extruded in a sheet form through a film forming die, and tightly contacted with a water-cooled rotating quenching drum for cooling to produce an unstretched film. Using a biaxial stretching test device (Toyo Seiki Co., Ltd.), the unstretched film was preheated at 120 ° C for 1 minute, and the fixed end was uniaxially stretched 4.0 times at 120 ° C to produce birefringent optics in the plane. membrane. The refractive index of the optical film at a wavelength of 550 nm is n _x = 1.701, n _y = 1.6015, and Δn = 0.0995.

The film thickness of the optical film was adjusted to obtain a PET film having a retardation value of 10,000 nm.

2. Synthesis of sesaminol-type benzotriazole ultraviolet absorber

A four-necked flask was equipped with a Dessert condenser, a mercury thermometer, a nitrogen blowing tube, and a stirring device, and 2- [2- (6-hydroxybenzo [1], a methacrylic acid-based benzotriazole-based monomer was placed therein , 3] 20 parts of dioxol-5-yl) -2H-benzotriazol-5-yl] ethyl ester, 20 parts of methyl methacrylate as other monomers, and 20 parts of toluene as solvent 20 parts of methyl ethyl ketone and 0.6 parts of 1,1'-azobis (cyclohexane-1-carbonitrile) as a polymerization initiator, while stirring the inside of the flask at a nitrogen flow rate of 10 ml / min. After 1 hour of nitrogen substitution, a polymerization reaction was performed at a reaction solution temperature of 90 to 96 ° C for 10 hours under reflux. After completion of the polymerization reaction, solvents (toluene and methyl ethyl ketone) were added to obtain a solution containing a sesaminol-type benzotriazole-based ultraviolet absorber (solid content: 40% by mass).

3. Production or preparation of optical films A1-1 ~ A1-4

On one side of the PEN film produced in the above "1", a resin layer a1 with the following formula was coated with a coating solution 1 and dried and irradiated with ultraviolet rays to form a resin layer a1 with a thickness of 10 μm to obtain an optical film A1-1 (The optical film of Example 1).

<Coating liquid 1 for resin layer a1>

‧Pentaerythritol triacrylate / 10 parts by mass

‧A solution (solid content component 40% by mass) / 90 parts by mass containing the sesaminol-type benzotriazole-based ultraviolet absorber (absorption peak wavelength 370nm) synthesized in the above "2"

‧Photopolymerization initiator / 4 parts by mass

‧Fluorine leveling agent / 0.2 parts by mass

‧Dilution solvent (methyl ethyl ketone) / 100 parts by mass

An optical film A1-2 (optical film of Comparative Example 1) was obtained in the same manner as the optical film A1-1 except that the coating liquid 1 for a resin layer a1 was changed to the coating liquid 2 for a resin layer described below.

<Resin layer coating liquid 2>

‧Pentaerythritol triacrylate / 50 parts by mass

‧A solution (solid content 40% by mass) / 50 parts by mass containing a sesaminol-type benzotriazole-based ultraviolet absorber (absorption peak wavelength 370nm) synthesized in "2"

‧Photopolymerization initiator / 4 parts

‧Fluorine leveling agent / 0.2 parts by mass

‧Dilution solvent (methyl ethyl ketone) / 100 parts by mass

As the optical film A1-3 (the optical film of Comparative Example 2), the PEN film produced in the above-mentioned "1" was prepared.

As the optical film A1-4 (the optical film of Comparative Example 3), the PET film produced in the above-mentioned "1" was prepared.

4. Measurement of spectral radiation of light in normal direction

(Spectral radiation y1 of light in the normal direction of the black light lamp)

Prepare a black light with a center wavelength of 365 nm (manufactured by Rongjin Chemical Co., Ltd., trade name: UV-LED LIGHT PB-365, and the ultraviolet illuminance at an irradiation distance of 40 cm is 6000 μW / cm ² or more). With a spectroradiometer (manufactured by Konica Minolta, trade name: CS-2000), the spectral radiation y1 (measurement angle) of light in the normal direction of the black light lamp is measured at a wavelength of 400 to 470 nm per 1 nm. (0.2 degrees). Calculate the cumulative value L ₁ of the spectral radiation y1 at each wavelength from 400 to 470 nm.

(Spectral radiation of light in the direction of the normal of the optical film A1-1 to A1-4 on the opposite side of the surface illuminated by the black light lamp x1)

The optical films A1-1 to A1-4 are arranged so as to be parallel to the light exit surface of the black light lamp. At this time, the optical film A1-1 and the optical film A1-2 are arranged so that the surface of the resin layer side of the optical film faces the light exit surface side of the black light lamp. The distance between the optical films A1-1 to A1-4 and the light exit surface of the black light lamp is set to 1 cm (the height of the outer edge of the black light lamp).

Then, the black light was made to emit light, and the normal direction of the surface of the optical film A1-1 to A1-4 on the opposite side of the surface illuminated by the black light was measured at a wavelength of 400 to 470 nm per 1 nm by the above spectroradiometer. The spectral radiation x1 of the light (measurement angle is 0.2 degrees). Calculate the cumulative value T ₁ of the spectral radiation x1 at each wavelength of 400 to 470 nm.

5. Measurement of spectral transmittance

Using a spectrophotometer (manufactured by Shimadzu Corporation, trade name: UV-2450), the spectral transmittance of 360 to 380 nm of the optical films A1-1 to A1-4 was measured at 0.5 nm intervals to calculate the spectral transmittance of 360 to 380 nm. The average value and the spectral transmittance of 370 ~ 380nm. The measurement condition of the spectral transmittance is set to a 2 degree field of view, and the light source is D65.

6. Evaluation

Prepare a commercially available organic EL display device (organic EL element is a three-color independent method with a microcavity structure. The coverage rate of BT.2020 is 77%). On the outermost surface of the organic EL display device, optical films A1-1 to A1-4 are bonded via an acrylic adhesive. The optical films A1-1 and A1-2 are arranged so that the resin layer side faces the surface side (the side opposite to the organic EL element side).

The organic EL display device laminated with the optical films A1-1 to A1-4 was taken out outdoors on a sunny day, and the state of the image was visually evaluated. The person who does not feel blue and white is set to "A", the person who slightly feels blue and white is set to "C", and the person who strongly feels blue and white is set to "D".

According to the results in Table 1, it can be confirmed that the organic EL display device of Example 1 in which T ₁ / L ₁ is 1.00 or less and which satisfies the condition 1 does not cause a problem of hue (cyan) in outdoor use. In addition, although not shown in the table, when the organic EL display device of Example 1 wore polarized sunglasses to observe an image, interference unevenness specific to the retardation value was not confirmed.

10‧‧‧Organic EL element

11‧‧‧ transparent substrate

12‧‧‧ transparent electrode

13‧‧‧Light-emitting layer

13a‧‧‧Red emitting layer

13b‧‧‧Green emitting layer

13c‧‧‧Blue emitting layer

14‧‧‧metal electrode

20‧‧‧Optical film A1

21‧‧‧ polyester film

22‧‧‧resin layer a1

30‧‧‧ surface plate

40‧‧‧Other optical film

50‧‧‧ polarizing element

100‧‧‧Organic EL display device

Claims (11)

An organic EL display device includes an optical film A1 on a light emitting surface of an organic EL element. The optical film A1 is a polyester film and a resin layer a1 containing an ultraviolet absorber. The resin layer a1 is formed on the light emitting surface of the organic EL element. The polyester film is formed on the surface opposite to the organic EL element side, and the optical film A1 satisfies the following condition 1: <condition 1> is on the outermost surface of the optical layer A1 on the resin layer a1 side with black light A black light lamp having a central wavelength of 365 nm is arranged so that the light emitting surface of the lamp is parallel to the optical film A1; a spectral radiance meter is arranged at a position directly opposite the black light lamp through the optical film A1; Luminescence, with the spectroradiometer, the spectral radiation x1 of light in the direction of the normal of the surface of the optical film A1 opposite to the side illuminated by the black light lamp is measured per 1 nm in a region of wavelength 400-470 nm; further, With the spectroradiometer, the spectral radiation y1 of the light in the normal direction of the black light lamp itself is measured at a wavelength of 400 to 470 nm for each 1 nm; the cumulative value of the spectral radiation x1 at each wavelength of 400 to 470 nm Set to T ₁ and set each wavelength from 400 to 470 nm When the cumulative value of the spectral radiation y1 is set to L ₁ , the relationship of T ₁ / L ₁ ≦ 1.00 is satisfied. For example, the organic EL display device of the first patent application range, wherein the average optical transmittance of 360 to 380 nm of the optical film A1 is 0.15% or less. For example, the organic EL display device of claim 1 or 2, wherein the polyester film is a polyethylene naphthalate film. For example, the organic EL display device of the first or second patent application range, wherein the organic EL display device The display device does not have a glass plate on the side of the surface from which light is emitted from the organic EL element light emitting layer. For example, the organic EL display device according to the first or second patent application scope has a polarizing element between the optical film A1 and the organic EL element. For example, the organic EL display device according to the first or second patent application scope, wherein the organic EL element is a three-color independent organic EL element. An organic EL display device includes an optical laminated body A2 on a light emitting surface of an organic EL element. The optical laminated body A2 is a polyester film and a resin layer a2 containing an ultraviolet absorber. The resin layer a2 is disposed on Opposite to the organic EL element side of the polyester film, the optical laminated body A2 does not contain a polarizing element, and the optical laminated body A2 satisfies the following condition 2, <condition 2> The optical laminated body A2 is more than the polyester On the outermost surface of the film closer to the resin layer a2 side, a black light lamp with a center wavelength of 365 nm is arranged so that the light emitting surface of the black light lamp is parallel to the optical film; the optical laminated body A2 is directly opposite the black light lamp. A spectroradiometer is arranged at the position; the black light is made to emit light, and the spectroradiometer is used to measure the surface of the optical laminated body A2 on the opposite side of the surface illuminated by the black light at a wavelength of 400 to 470 nm per 1 nm. The spectroradiation of light in the normal direction x2; further, with the spectroradiometer, the spectroradiation of light in the direction of the normal direction of the black light lamp itself is measured at a wavelength of 400 ~ 470nm for each 1nm; Spectral radiation at each wavelength of 470nm The cumulative value of x2 is set to T _2, the cumulative value of the wavelength of the spectral radiation y2 at each wavelength of 400 ~ 470nm is set to ₂ L, satisfies ₂ / L ₂ ≦ relationship of T 1.00. For example, the organic EL display device of the seventh scope of the patent application, wherein the polyester film is polynaphthalene Ethylene Diformate Film. For example, the organic EL display device according to item 7 or 8 of the patent application scope, wherein the organic EL display device does not have a glass plate on the side of the surface from which light is emitted from the light emitting layer of the organic EL element. For example, an organic EL display device having the scope of claims 7 or 8 has a polarizing element between the optical multilayer body A2 and the organic EL element. For example, an organic EL display device according to item 7 or 8 of the patent application scope, wherein the organic EL element is a three-color independent organic EL element.